Symposium Organizers
Juan C. Nino University of Florida
Fred Roozeboom NXP Research
Susan Trolier-McKinstry The Pennsylvania State University
Paul Muralt Swiss Federal Institute of Technology EPFL
David LaVan Yale University
W1: Packaging and Embedded Components
Session Chairs
Monday PM, November 27, 2006
Room 303 (Hynes)
9:30 AM - **W1.1
Using Low-firing Microwave Ceramics in LTCC Type Components.
Danilo Suvorov 1 , C. Hoffmann 2
1 , Institute Jozef Stefan, Ljubljana Slovenia, 2 , EPCOS OHG, Deutschlandsberg Austria
Show AbstractMicrowave ceramic materials have been used over several years to produce monolithic filters for various wireless applications. Material classes with different dielectric properties are known and were used accordingly. During the last five years the usage of these types of components has been declining due to physical constrains based on the underlying design principles. Today very little application like cellular base stations require monolithic components.Today performance and size standards are set by other technologies like SAW filters. In order to meet these challenges the application of new design concepts along with new technologies are required. The design concepts range from folded quarter wave length resonators to lumped element designs and are based on a multi-layer, via forming kind of technology. To reach the full potential of this technology it is necessary to develop new materials which have good microwave properties and allow an all-silver co-fire process.This paper describes the materials which were developed and there applications. It will focus on the development of glass-free low sintering materials with dielectric constants between 20 and 90, low losses and low temperature coefficients. The co-fire ability with silver electrodes will be discussed. Applications for these materials will be presented.
10:00 AM - W1.2
Reaction Mechanism of Chemically-Driven Zero Shrinkage LTCC
Yong Jun Seo 1 , Yong Soo Cho 1
1 Materials Science and Engineering, Yonsei University , Seoul Korea (the Republic of)
Show AbstractThe Shrinkage variation has been a critical issue in conventional LTCC (Low Temperature Co-fired Ceramics) processing in that it creates serious problems such as high failure rate of devices and a subsequent increase of production cost. To deal with these critical problems, several zero shrinkage approaches have been introduced including the so-called release tape technique and the self-constraining tape technique. These techniques are technically based on the physical constraining effect by using the difference of shrinkage path during firing. However, these techniques require additional experimental procedure, i.e., eliminating the so-called release tape such as highly refractive alumina or zirconia through mechanical scrubbing. Even though there are no additional steps for self-constraining tape technique, this technology may cause unexpected failures such as delamination and macro-cracks due to the poor mechanical integrity of the hetero-tapes. This work first demonstrates a new approach of producing zero x-y shrinkage without both any additional processing step and sacrificial layer. Carefully-designed LTCC materials have successfully demonstrated that the production of zero x-y shrinkage is reliable with competitive performance under common firing conditions at 850-900 oC. Dielectric and physical properties changed depending on glass composition that determines the chemical reactivity and densification behavior. Dielectric constants of 4-9 and loss tangents of < 0.05 were typical values for the new zero shrinkage LTCC. Reaction Mechanism of the zero shrinkage LTCC is the major focus of this presentation with successful demonstration of resulting promising LTCC performance.
10:15 AM - W1.3
Chemical Leaching Resistance of Glass-Based LTCC Systems.
Wonbae Lim 1 , Yong Soo Cho 1 , Jae Gwan Park 2
1 Department of Materials Science and Engineering, Yonsei University , Seoul, Seoul, Korea (the Republic of), 2 Materials Science and Technology Division, Korea Institute of Science and Technology, Seoul, Seoul, Korea (the Republic of)
Show Abstract10:30 AM - W1.4
Investigation of Ultralow Loss Interconnection Technique for LTCC based System-in-Package(SIP) Technology at 60GHz.
Dong-Young Kim 1 , Jae Kyoung Mun 1 , Dong-Suk Jun 1 , Haechoen Kim 1
1 , ETRI, Daejeon Korea (the Republic of)
Show AbstractDespite the emergence of new packaging and interconnect technologies, wire-bonding remains the dominant conventional low cost, high reliability and high manufacturability chip connection technology. With increasing frequency to microwave and millimeter wave frequency range, however, wire bonds exhibits increased parasitic effects that impact the module performance. In addition, radiation loss due to discontinuity caused by wire bends on both ends of the wire becomes significant, particularly in the millimeter wave frequency range. In this presentation, effects of wire- and ribbon-bonded interconnection on the millimeter wave transmission characteristic will be presented.Ferro A6S was used as a greensheet. A finite-element method (FEM)-based full-wave simulator (HFSS) was used to design the transmission line and interconnection modeling. The insertion loss of CBCPW(Conductor backed coplanar waveguide) lines was order of 0.1dB/mm. The test patterns for interconnection characterization were designed and manufactured using conventional LTCC process. Four kinds of bonding (single wire, double wire, single ribbon, and double ribbon) were performed as an interconnection method. In the case of CBCPW lines with dielectric thickness of 100μm, the insertion loss of single-wire bonded line was –0.17dB. As the number of bonded wire increased to two, the insertion loss decreased to –0.10dB. The insertion loss of single-ribbon bonded line was –0.10dB. The insertion loss of double-ribbon bonded line was as small as –0.09dB. These insertion losses included the line loss, contact loss between line and measuring probe, and loss due to interconnection. Therefore, the loss due to bonding itself will be ultra low and nearly negligible. In the case of interconnection with CBCPW lines with dielectric thickness of 200μm, the transmission characteristic shows somewhat different results. The insertion losses of double-wire bonded and single-ribbon bonded line were –0.35dB and –0.31dB, respectively. These differences of insertion loss may be due to the difference of signal line width. The signal line width of CBCPW line with dielectric thickness of 100μm was 94μm, however, that of CBCPW line with dielectric thickness of 200mm was 145μm. As the dielectric thickness increases, the bonded wire or ribbons was far from the ground. Therefore, they have high characteristic impedance. This high impedance discontinuity invokes high reflection, and the insertion loss will be increased. As the number of bonded ribbon increased to two, the insertion loss decreased to -0.12dB. Detailed experimental results will be presented.
11:15 AM - **W1.5
Influence of Full-filled Polymer Molding on High-frequency Circuits.
Masayuki Fujimoto 1 , Kiyoshi Nakanishi 1
1 , Shizuoka University, Hamamatsu Japan
Show Abstract11:45 AM - **W1.6
Thin Film Dielectrics for Embedded Applications.
Jon-Paul Maria 1 , Jon Ihlefeld 1 , Patrick Daniels 1 , William Borland 2
1 Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina, United States, 2 , Dupont Electronic Technologies, Research Triangle Park, North Carolina, United States
Show AbstractNumerous researchers have pursued the integration of high permittivity thin film dielectric materials in high volume application since the mid 1980s. Appreciation of this goal has been slower than anticipated for a variety of reasons, perhaps most importantly, the incredible complexity of ferroelectric materials under challenging physical, electrical, and mechanical boundary conditions. In this presentation we discuss recent efforts at NCSU to develop methods for preparing device quality ferroelectric thin film processes that overcome several cost and complexity issues. In this presentation we focus on compositions from the (Ba,SrTi)O3 (BST) solid solution deposited on low cost substrates, specifically thin copper foil, which are targeted towards embedded capacitor applications.The materials challenges associated with this work are centered upon achieving process compatibility as it pertains to thermal expansion, chemical reactivity, and interface formation. In all cases, the necessary pathways to success involve a fundamental understanding of processing science. Our methods for chemical solution deposition and sputtering of BST will be discussed, with specific attention to two recent advances: fluxed-assisted densification and grain growth for solution deposited BaTiO3, and novel annealing methods that promote large area electrode formation in sputtered BST. Respectively, these advances have provided for (1) room temperature permittivity values in excess of 3000, and (2) near 100% capacitor yield for 800 nm thick dielectric layers with capacitor diameters of 5 mm in the absence of any clean room processing steps.Finally, we will discuss how these improvements are being exploited in a collaborative program between NCSU and Dupont Electronic Technologies, which is currently on track to commercialize mass-produced BaTiO3 thin films for embedding into printed wiring boards.
12:15 PM - W1.7
Dielectric Properties of PCB Embedded bismuth-zinc-niobium Films Prepared using RF Magnetron Sputtering.
Seungeun Lee 1 , Jungwon Lee 1 , Yulkyo Chung 1
1 , Samsung Electromechanics, Suwon Korea (the Republic of)
Show AbstractWe present recent results of dielectric properties of bismuth-zinc-niobium (BZN) oxide thin films embedded into printed circuit board. BZN has a pyrochlore structure in nature and shows a dielectric constant of ~ 200 and very low leakage current when crystallized. Since the process temperature is limited to < 200oC due to the organic substrate the fabricated BZN film is not crystallized according to XRD, but it shows remarkably high dielectric constant of 70. This makes BZN to be a proper candidate as a decoupling embedded capacitor in power delivery circuits. We show that BZN film is well processed in the existing PCB line and provides a capacitance density as high as 150 nF/cm2.
12:30 PM - **W1.8
Active Microelectronic Circuit Elements on Silicon, Ceramic and Polymer Substrates.
Angus Kingon 1 , Taeyun Kim 1 , Jon-Paul Maria 1 , Peter Lam 1 , Michael Steer 1 , Dan Lictenwalner 1
1 , North Carolina State University, Raleigh, North Carolina, United States
Show AbstractThere is currently an increasing ability to integrate active circuit elements into microelectronic system on substrates alternative to silicon. The substrate choices include high density multilayer polymer-based printed wiring boards (PWBs), and alumina and LTCC, in addition to silicon. This paper discusses frequency-tunable circuits as an example to demonstrate this capability. The frequency tunability is achieved through the use of (Ba,Sr)TiO3 voltage tunable capacitors (varactors) incorporated into the system. Where the active circuit is integrated is dependent not on size and cost, but by materials compatibility and processing issues, and system performance. The various trade-offs are discussed for tunable filters, and extended to matching networks, tunable antennae, and sensors.
W2/V1: Joint Session: System in Package
Session Chairs
Monday PM, November 27, 2006
Room 206 (Hynes)
2:30 PM - **W2.1/V2.1
Silicon Based System-in-Package : Breakthroughs in Miniaturization and ”nano”-integration Supported by Very High Quality Passives and System Level Design Tools.
Franck Murray 1 , François LeCornec 1 , Serge Bardy 1 , Catherine Bunel 1 , Jan Verhoeven 2 , Erik van der Heuvel 2 , Johan Klootwijk 2 , Fred Roozeboom 2
1 , NXP Research, Caen France, 2 , Philips Research, Eindhoven Netherlands
Show Abstract3:00 PM - **W2.2/V2.2
Process and Material Requirements for Successful Heterogonous Passive Component Integration in RF System.
Eric Beyne 1 , Walter De Raedt 1 , Geert Carchon 1 , Philippe Soussan 1
1 , IMEC, Leuven Belgium
Show AbstractAs wireless communication devices become more abundant in numbers and variety, high-density system integration is becoming an increasingly important requirement. High-density integration of RF radio devices not only requires integration of active devices (RF system-on-a-chip [RF-SoC]), it also requires the integration of a large number of passive devices, such as transmission lines, resistors, capacitors and inductors, as well as functional blocks, such as filters and baluns. To reduce system size and cost, a higher degree of miniaturization is required. These components do not scale as well as active IC technology, making it difficult to integrate all these devices on chip. Such technologies may be integrated on the die or in the package using heterogeneous integration technologies. (rf-System-in-a-Package, rf-SIP)This paper will present the system-level requirements for integrated passives integration for rf systems. Requirements for material characteristics and device process tolerances will be discussed.As a key enabling technology for the realization of the passive component integration, the multilayer thin-film technology will be presented. A key feature of this technology is the use of photolithographic technology for the definition of the various passive circuit components, resulting in a high degree in miniaturization and high patterning accuracy, with tolerances in the micron and submicron ranges. This results in excellent circuit repeatability and predictability, key ingredients for the realization of first-time-right and high-manufacturing-yield devices. This technology may be applied to passive substrates or active device wafers. Examples of both will be presented.
4:30 PM - **W2.3/V2.3
Through Wafer Interconnects – a Technology not only for Medical Applications.
Gereon Vogtmeier 1 , Christian Drabe 3 , Ralf Dorscheid 2 , Roger Steadman 1 , Alexander Wolter 3
1 X-ray Imaging Systems, Philips Research Europe, Aachen Germany, 3 , Fraunhofer Institute Photonic Microsystems, Dresden Germany, 2 Engineering and Technology, Philips Research Europe, Aachen Germany
Show AbstractThe foremost driver for the development of fully CMOS compatible Through Wafer Interconnects (TWIs) is the need of very large photodiode arrays for detectors, e.g. computed tomography application. Only the front to back-side contact allows the four-side buttable chip placement of the already large chips (20 mm x 22 mm). The TWI technology allows an interconnection for chips up to 280µm thickness and it also enables a metal signal routing on the active side, on top of the interconnection. The application specific optical sensitive front-side of the chip is fully accessible. This is very important, as the imager process with the optical interface to an x-ray converting scintillator material on top of the imager is not limited by the TWI-process. The whole process has been thought to be fully CMOS-fabrication compatible.In more detail the production process is separated into three main steps. The first step is the implementation of the special TWI geometry into the raw wafer. Depending on the electrical and geometrical requirements of the circuit different TWI structures are available – also within one wafer or chip design. All geometries are built with deep trenches (up to 280µm), which are passivated and filled with doped poly-silicon. The used technologies like DRIE-etching, oxidation and low pressure CVD are standard CMOS compatible processes. Low leakage current and shielded conductive structures, e.g. coaxial double ring structures, have been selected as most valuable for our application.After this first step the conductive structure is already located at the correct position in the wafer before proceeding with the standard CMOS process. The CMOS process runs normally on the front-side as if a polished raw wafer was being used. The use of poly-silicon limits the conductive interconnection to a certain resistance but allows the use of all CMOS process steps for an imager production (no temperature limitation – compared to other TWI process flows).The third step is a low temperature back-side process starting with wafer thinning down to 280 µm or less (depending on the final wafer thickness) to open the implemented TWI structure from the back-side. The thickness may be selected depending on the application. For Computed Tomography a thick wafer is desired to ensure proper mechanical stability.A modified under ball metallization (UBM) process, which could include also re-routing of signals on the back-side, concludes the process flow until the ball placement or similar bond connections are done.The special process flow opens a variety of applications, which benefit from the full CMOS compatible processing and the accessible front-side.
5:00 PM - W2.4/V2.4
FsCSP Packaging Technology: Case Studies on Package Processability and Reliability Performance and its Dependence on Material Properties
Rahul Manepalli 1 , Chris Matayabas 1 , Eduardo Gacho 1
1 Assembly Technology Development, Intel Corporation, Chandler, Arizona, United States
Show Abstract5:15 PM - W2.5/V2.5
The Flexible Physiological Monitor of Patch Type Package Based on Non-weave Material.
Wen-Yang Chang 1 2 , Hung-Hsin Tsai 1 , Ying-Chiang Hu 1
1 , Industrial Technology Research Institute, Tainan Taiwan, 2 Microsystems Technology Center, Industrial Technology Research Institute, Tainan Taiwan
Show Abstract5:30 PM - W2.6/V2.6
An Approach for Characterizing Residual Mechanical Stress by Packaging Processes.
Soeren Hirsch 1
1 FEIT-IMOS, University of Magdeburg, Magdeburg Germany
Show Abstract5:45 PM - W2.7/V2.7
Laser Printing Method for Manufacturing of Flexible Copper Electrodes and Interconnects
Nurdan Demirci Sankir 1 , Andrea Hill 1 , Jennifer Lalli 1 , Brad Davis 1 , Hang Ruan 1 , Richard Goff 2 , Richard Claus 3 4
1 , NanoSonic Inc., Blacksburg, Virginia, United States, 2 Department of Engineering Education, Virginia Tech, Blacksburg, Virginia, United States, 3 Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia, United States, 4 Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia, United States
Show AbstractW3: Poster Session
Session Chairs
Tuesday AM, November 28, 2006
Exhibition Hall D (Hynes)
9:00 PM - W3.1
Ferrite Plating By Spin Spray Technique Without Using Any Strong Oxidizing Agents.
Subramani Ailoor Krishnan 1 , Matsushita Nobuhiro 1 , Watanabe Tomoaki 1 , Tada Masaru 2 , Abe Masanori 2 , Yoshimura Masahiro 1
1 Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama Japan, 2 Department of Physical Electronics, Tokyo Institute of Technology, Tokyo Japan
Show AbstractSpin spray technique, which is a soft solution process, is employed in the preparation of ferrite films. In the conventional spin spray technique a reaction solution (FeCl2) and an oxidizing solution (KNO2 + CH3COOK) is sprayed independently on the substrates mounted on the rotating disc. The present interest is to make the spin spray technique further simpler and eco-friendly by using a one solution, which has no strong oxidizing agents like NaNO2 or KNO2. Highly crystallized ferrite films were prepared by spraying only one solution at a very low temperature of 90°C without any post annealing. Reaction solution containing a mixture of FeCl2, CH3COOK and Urea was employed. The obtained films were studied for their structural, morphological and magnetic properties. This “One solution” spin spray technique does not involve the use of any strong oxidizing agents NaNO2, which is hazardous material, and has the advantage of easy scalability in real production.
9:00 PM - W3.10
Fabrication of SiN-assisted 0.12um AlGaAs/InGaAs PHEMT and 60GHz-bands MMICs for 60GHz WPAN system
Hokyun Ahn 1 , Jong-Won Lim 1 , Hong-Gu Ji 1 , Woo-Jin Chang 1 , Jae-Kyoung Mun 1 , Haecheon Kim 1
1 RF Circuit Group, Electronics and Telecommunications Research Institute, Daejeon Korea (the Republic of)
Show AbstractRecently, millimeter wave applications such as high speed wireless communications, collision avoidance car radar systems and millimeter wave video transmission systems have been developed. Especially, unlicensed 60GHz-bands are of growing interest for high rate personal area network (WPAN) (IEEE 802. 15. 3) and high rate wireless local area network (WLAN). Millimeter wave MMICs of such applications have been fabricated through a III-V compound-based technology related to active devices such as GaAs-based HEMT, InP-based HEMT and InP-based HBT. Especially, p-HEMT devices are widely utilized as active devices of millimeter wave MMICs due to an excellent and stable RF performance. The gate shape of the p-HEMT device as well as the gate foot length has a major effect on parasitic capacitances including Cgs which is correlated to RF performances including a cut-off frequency (fT) and a maximum frequency of oscillation (fmax). In this work, we describe the fabrication technology of SiN-assisted 0.12um double deck T-gate AlGaAs/InGaAs p-HEMT and 60GHz-bands MMICs for the high rate personal area network (WPAN) system. This paper also presents the effect of the gate shape such as the 1st-deck and the 2nd-deck gate head size on the DC and RF characteristics of SiN-assisted 0.12um double deck T-gate AlGaAs/InGaAs p-HEMT devices and the device performance of the p-HEMT at the optimum gate head size. At 0.28um of the optimum 1st-deck gate head size and 1um of the 2nd-deck head size, the p-HEMT device with two finger gates of 0.12um length x 50um width shows an extrinsic transconductance of 589mS/mm and a threshold voltage of -0.89V. The cut-off frequency and the maximum frequency of oscillation were 99GHz and 191.5GHz, respectively. The gate shape of the p-HEMT device such as a gate head size is correlated to parasitic capacitances including Cgs which have effects on RF performances including a cut-off frequency (fT) and a maximum frequency of oscillation (fmax).
9:00 PM - W3.11
Tailoring Bio-Inspired Magnetic Vesicles for Controlled Release.
Muhammet Toprak 1 , Brandon McKenna 1 , Herbert Waite 2 , Galen Stucky 1 3
1 Chemistry and Biochemistry, UCSB, Santa Barbara, California, United States, 2 Marine Science Institute and MCDB , UCSB, Santa Barbara, California, United States, 3 Materials, UCSB, Santa Barbara, California, United States
Show AbstractThe synthesis of organic and inorganic nano- and microspheres has attracted much interest for a variety of applications ranging from drug delivery to chemical storage and catalysis. Previously, our group demonstrated that specifically tailored block copolypeptides and polyelectrolytes can be utilized to self-assemble various nanoparticles into functional micrometer sized assemblies such as hollow multi-layered quantum dot microlasers. We also demonstrated an assembly of magnetic nanoparticles and polycations into vesicles in a single-step synthesis via a bio-inspired self-assembly route, i.e. complex coacervation. The process is based on specific interactions of polypeptides with organic salt. These vesicles showed viability for bio-applications as indicated by toxicity tests, and are therefore potentially targeted drug delivery devices as they can be driven magnetically.This work reports the recent progress on the potential use of these assemblies in drug release by controlling their porosity. Fluorescence molecules with different MW have been entrapped in these entities and the fluorescence recovery rates have been determined by confocal fluorescence microscopy, the results of which were then fit into a model to obtain the porosity information. Different physicochemical characterization results area also presented.
9:00 PM - W3.12
A Charge Feedback Controller for a Piezoelectric Voltage Amplifier/Driver.
Maciej Noras 1 , Peter McAnn 1 , Jerzy Kieres 1
1 , Trek, Inc., Medina, New York, United States
Show AbstractIn this paper, authors examine the design and implementation of a new charge feedback control circuitry for a voltage amplifier used in driving of a piezoelectric actuator. Actuators driven in the usual voltage feedback regime display a nonlinear voltage-displacement relationship, known as hysteresis. Use of the new charge feedback control circuitry resulted in significant reduction (80%) of the hysteresis-related nonlinearity.
9:00 PM - W3.13
Ohmic Contacts on Single Crystal Si and SiC by Thermal Spray Technique
Sumit Taraphdar 1 , Juan Rojo 1 , Richard Gambino 1 , Sanjay Sampath 1
1 , Stony Brook University, Stony Brook, New York, United States
Show AbstractDirect Write Thermal Spray is an innovative means to integrate robust, reproducible materials for sensors, electronics, interconnects, RF components, and semiconductor devices. The use of semiconductor materials for these applications is attracting increasing attention for this technology for use as both sensors and active devices. A key challenge, however, is to establish reliable electrical connections to thermal sprayed semiconductor materials, particularly when the metallic connector is also thermal sprayed. The nature of the junction (Schottky, ohmic) as well as the junction resistance are central to developing repeatable, reliable semiconductor-metal junctions for interconnects. Ni-Al alloy (95-5%) ohmic contacts have been directly deposited on silicon and silicon carbide single-crystal substrates by thermal spray technology and their electrical properties have been characterized. The as-deposited contacts showed good ohmic characteristics after thermal spray deposition. In addition, the contacts were annealed at four different temperatures and their I-V characteristics obtained for each of those temperatures. The ohmic characteristic with annealing temperature was found to follow a parabolic curve with a minimum giving an optimum ohmic property at 450 degrees centigrade.
9:00 PM - W3.14
Effect of Disorder in Zirconia Thin Films for High Energy Density Capacitors
Guneet Sethi 1 , Michael Lanagan 1 , Mark Horn 1
1 Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania, United States
Show AbstractZirconium oxide thin films were prepared through reactive magnetron sputtering with the aim of optimizing the thin film processing parameters to produce 0% crystallanity (amorphous) films. Reduction in the crystallanity will improve dielectric breakdown strength, dielectric losses and the energy density. Both semi-crystalline and crystalline films were prepared by controlling the ion bombardment through different process parameters such as power, pressure, power supply type (RF vs. Pulsed-dc), substrate-target distance, substrate temperature and bias. These parameters were optimized for producing smooth, stoichiometric and dense films with high deposition rate quantified through AFM, SEM and EDS. The film thicknesses for semi-crystalline (<10%) and crystalline films (≈60%) were around 50nm and 500nm respectively. The dielectric films were characterized for capacitance and dielectric losses with temperature. The effect of annealing on the dielectric properties was studied and correlated with change in crystallanity with temperature. Annealing at 150°C greatly reduced the losses with no changes in crystallanity due to better contact formation. The dielectric constant and losses were high for semi-crystalline than crystalline thin films (∼8-15% difference) at 1V. However, the dielectric constant and losses were more realistic at lower voltages (≈0.1V) for semi-crystalline films because of their lower thickness. The dielectric losses were higher for semi-crystalline films prepared by pulsed-dc than RF sputtering. The space charge relaxation in both these films started to appear at high temperatures (>250°C). DC current-voltage measurements at different temperatures were also performed to find DC conductivity. The resistivity (108ohm-m) for semi-crystalline films was comparable to high equality gate oxides. Space charge was identified as the main conduction mechanism in DC measurements. Finally the DC/AC conduction mechanisms will be correlated with the breakdown strength.
9:00 PM - W3.15
Growth, Characterization and THz Applications of III-VI Semiconductor GaSe.
Krishna Mandal 1 , Michael Choi 1 , Sung Kang 1 , R. David Rauh 1
1 Materials Science Research Department, EIC Laboratories, Inc., Norwood, Massachusetts, United States
Show Abstract9:00 PM - W3.2
Improved Microwave Dielectric Properties Of Alkaline Earth-Containing Lanthanum Borates.
Yeon Hwa Jo 1 , Yong Jun Seo 1 , Yong Soo Cho 1 , Dong Heon Kang 2
1 Materials Science & Engineering, Yonsei University, Seoul Korea (the Republic of), 2 Electronic Materials Engineering, The University of Suwon, Suwon Korea (the Republic of)
Show AbstractImproved microwave dielectric properties of lanthanum borate (La2O3-B2O3) glass compositions modified with alkaline earth oxides such as CaO, MgO and ZnO have been demonstrated for the purpose of using them as a low temperature co-fireable system. The low temperature microcircuit technology provides practical and viable merits primarily in that inexpensive low-melting conductor (e.g., Ag and Cu) can be utilized with the subsequent increment of integration density. Several different batches of glass consisting of 60 mol% B2O3, 20 mol% La2O3, and 20 mol% alkaline earth oxide, i.e., CaO, MgO, or ZnO were successfully prepared by quenching melts from 1400oC. A fixed amount of 40 wt% Al2O3 filler was then added to form rigid samples through subsequent firing at 850oC for 30 minute in ambient atmosphere. As a specific example of improved dielectric characteristics through the incorporation of alkaline earths, a high-quality factor of ~1090 and a dielectric constant of 8.32 at 17.04 GHz was obtained for the Zn- added material system. Typical quality factor values are 150-200 as reported. Understanding of developed crystalline phases during the firing process and their correlation to consequential microwave dielectric properties in the newly-developed material system are the main purpose of this presentation.
9:00 PM - W3.3
High Performance Low Temperature Co-fired Ceramic Modules for 60 GHz WPAN Systems.
Jae Kyoung Mun 1 , Dong-Young Kim 1 , Woo-Jin Chang 1 , Jong-Won Lim 1 , Hokyun Ahn 1 , Hong Gu Ji 1 , Haecheon Kim 1
1 IT components & Material Research Division, ETRI, Daejeon Korea (the Republic of)
Show AbstractThe increasing demands for high-speed (>1Gbps) multimedia data communications, such as a huge data file transmission and real-time video streaming, stimulated the development of 60 GHz-band wireless communication systems. For successful use of these systems especially in consumer markets, low-cost high-producible RF module technologies are required. Miniaturization, portability, cost and performance have been the driving forces for the evolution of packaging and system-in-package (SIP) approach in RF, microwave and millimetre-wave applications. Low temperature co-fired ceramic (LTCC) technology is one of the most promising candidates for a SIP up to millimetre-wave bands. Using this technology, we can obtain high integration density by embedding passive elements in the layers while active devices are mounted in the surface cavity.To investigate the feasibility of a multilayer LTCC technology as substrate as well as packaging material for millimetre-wave 60 GHz wireless transceiver module. This requires low-dielectric and conductor losses. The Ferro A6-S LTCC sheets were chosen because of its low loss tangent (<0.002 up to 100 GHz), low insertion loss and low-cost for mass production. Wire-bonding technology is still extensively used as a chip interconnection method because of its simplicity of assembly and reduction of final manufacturing cost. In this study, the chip performance is degraded only a little of S21<-0.5dB at 60 GHz after interconnect using ribbon wire-bonding technique and conductor backed coplanar waveguide (CBCPW) transmission line. Therefore, we adopted LTCC and wire-bonding interconnection technologies as a promising solution for cost- effective millimetre-wave 60 GHz wireless transceiver module.Via holes, embedded ground planes and backed conductors were metallized with silver conductor. However, the RF signal line and coplanar ground plane on the top layer were made of gold conductor to reduce conducting loss and enhance wire-bonding connectability. In the module fabrication, the LNA and power amplifier (PA) chips are mounted in the cavity and wired by 2mil-thick ribbon to the 50 Ω transmission line of the LTCC module.The RF characteristics for chips and modules were analyzed to investigate performance degradation at 60 GHz after mounting onto the LTCC module by measuring the scattering parameters for bare chips and LTCC modules at the frequency range of 50 to 70 GHz. The fabricated LNA and PA modules exhibited only a little degradation of chip performance (S21<-0.5 dB for LNA and S21<-0.1 dB for PA at 60 GHz) after interconnect using ribbon wire-bonding technique and CBCPW transmission line.In this paper, we present low-cost LNA and PA modules based on the multilayer LTCC technology and LNA and PA MMICs developed in ETRI using 0.12μm AlGaAs/InGaAs/GaAs pHEMT library. These modules will be used as a building block of optical/electrical transceiver for 60 GHz wireless personal area network (WPAN) systems.
9:00 PM - W3.4
Investigation of Millimeter-Wave Characteristics of Transmission Lines Manufactured using LTCC Technology.
Dong-Young Kim 1 , Jae Kyoung Mun 1 , Dong-Suk Jun 1 , Haechoen Kim 1
1 , ETRI, Daejeon Korea (the Republic of)
Show AbstractSystem and hardware investigations on the broadband mobile wireless access at 60-GHz band have been widely conducted around the world. These applications required compact, high performance, and low-cost wireless equipment. Low temperature co-fired ceramics (LTCC) is one of the most promise candidates in system in package (SIP) at millimeter wave bands. LTCC technology has many advantages such as low loss in millimeter wave bands, high integration density, and high reliability. LTCC is a multiplayer ceramic technology, which provides an ability to embed passive component in layers while the active elements are mounted on the surface layer. The transmission lines are basic elements of packaging. In order to produce well-designed module, or system, the transmission loss should be reduced as low as possible. However, there are few reports on the characteristics of transmission lines produced by LTCC at millimeter-wave bands. In this paper, we reports the 60-GHz transmission characteristics of lines produced by LTCC technology, and the difference of transmission characteristics between two different green sheets. Two kinds of green sheet having different dielectric characteristics (Dupont 943 and Ferro A6S) were used as a dielectric substrate. The dielectric constant and loss tangent of Dupont 943 greensheet at 60GHz were 7.2 and 0.005, respectively. Those of Ferro A6S was 5.9 and less than 0.002, respectively. Microstrip lines and CBCPW(conductor backed coplanar waveguide) lines with characteristic impedance of 50 ohm were designed using HFSS software. The dielectric thickness of lines were 100μm (one layer) or 200μm (two layers). LTCC module with total 500μm(5 layers) including dummy ground layers was manufactured by conventional LTCC process.The S21 of 6mm CBCPW line with 200μm dielectric thickness were –2.5dB (Dupont 943) and –0.6dB (Ferro A6S), respectively. The S11 or S22 were nearly same as –20dB in both cases, which represents the impedance of lines were nearly 50ohm. The dielectric loss tangent of Dupont 943 is higher than Ferro A6S greensheet. The measured dielectric loss tangent of Ferro A6S greensheet was 0.001 at 60 GHz. Therefore, the transmission line loss of Ferro A6S greensheet was much smaller than that of Dupont 943 greensheet. The transmission characteristics of CBCPW line with 100μm dielectric thickness shows nearly same as that with 200μm dielectric thickness. The transmission characteristics of microstrip lines showed similar characteristics with CBCPW lines. The insertion loss of microstrip lines was near 0.1dB/mm. This means that LTCC is suitable for low loss transmission millimeter-wave bands.
9:00 PM - W3.5
Influences of Particle Size of Alumina Filler In An LTCC System.
Jinhyun Jeong 1 , Yong Jun Seo 1 , Yong Soo Cho 1 , Jun Chul Kim 2 , Nam Kee Kang 2
1 Department of Materials Science and Engineering, yonsei university, Seoul Korea (the Republic of), 2 , Korea Electronics Technology Institute, Seongnam Korea (the Republic of)
Show Abstract9:00 PM - W3.6
Effects of Pb-content Interlayer on PZT Composite Thick Film.
Yu-Kuang Ko 1 , Chang Horng-Yi 1 , Cheng Syh-Yuh 1
1 Material and Chemical Research Laboratories, Industrial Technology Research Institute, Chutung Taiwan
Show Abstract9:00 PM - W3.7
Strategies for the Integration of Ferroelectric Thin Films on Base-Metal Foils for High Voltage Embedded Passives.
David Kaufman 1 , Krishna Uprety 1 , Beihai Ma 1 , U. (Balu) Balachandran 1
1 , Argonne National Laboratory, Argonne, Illinois, United States
Show Abstract9:00 PM - W3.8
Roles of Fluoride Additives In Pb-Free Thick Film Capacitors on CU Foils.
Dong Joo Shin 1 , Jong Won Lee 1 , Yong Soo Cho 1 , Jun Chul Kim 2 , Woo Sung Lee 2 , Nam Ki Kang 2
1 Department of Materials Science and Engineering, Yonsei University , Seoul Korea (the Republic of), 2 , Korea Electronics Technology Institute, Seongnam, Gyeonggi-do, Korea (the Republic of)
Show AbstractBaTiO3-based thick films with enhanced dielectric properties were prepared on copper foils by the screen printing technique. Due to the restriction of firing condition mainly related to high oxidation tendency of Cu, there have been difficulties in achieving reliable electrical performance of resulting thick films on Cu-foils. In this work, high k thick film capacitors containing Pb-free specific glass and fluoride compounds such as LiF, ZnF2, BaF2, AlF3 and CaF2 were demonstrated as a result of controlled firing process. For direct comparison of each fluoride, the same processing condition including the identical ratio of BaTiO3/glass/fluride and firing sequence was used. All samples were prepared by screen printing thick film pastes on Cu-foils, dried at 120oC, burned out at 400oC and finally fired at 900 ~ 950oC in N2 atmosphere. The selection of fluoride was found to enormously influence the physical and dielectric performance of thick films. Broad ranges of dielectric constant (450 to 2,500) and transition temperature (40 to 115oC) were obtained depending on fluoride compounds. As an optimum composition, 95% BaTiO3, 3% lithium/zinc fluoride and 2% glass showed a dielectric constant of ~2,500 and a loss tangent of ~0.03 at 1MHz. The main purpose of this presentation is to understand the effect of individual fluoride compound on the physical and electrical properties of newly-developed thick film capacitors that are applicable for embedded passives in multilayered printed circuit boards.
9:00 PM - W3.9
γ-Irradiation Stimulated Change of Recycled Polypropylene Composites Dielectric Permittivity
Ulmas Gafurov 1
1 , Institute of Nuclear Physics, Tashkent Uzbekistan
Show Abstract
Symposium Organizers
Juan C. Nino University of Florida
Fred Roozeboom NXP Research
Susan Trolier-McKinstry The Pennsylvania State University
Paul Muralt Swiss Federal Institute of Technology EPFL
David LaVan Yale University
W4/T4: Joint Session: Capacitors
Session Chairs
Tuesday AM, November 28, 2006
Room 302 (Hynes)
9:30 AM - **W4.1/T4.1
An Engineering Perspective: Toward Temperature Insensitive Electric-Field Tunable Material and Devices.
Steven Tidrow 1 , Frank Crowne 1 , Arthur Tauber 1 , Daniel Potrepka 1 , Steven Weiss 1 , Bernie Rod 1
1 Sensors & Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, Maryland, United States
Show AbstractRecently there has been much interest in electric-field tunable dielectric materials, many from the perovskite family, for use in phase shifters for microwave electronic scanning antenna arrays and for frequency agile components like electric-field tunable filters. Materials that are highly electric-field tunable are typically high dielectric constant materials, ferroelectric or anti-ferroelectric, that are, at least in bulk form, quite temperature sensitive and can be quite lossy with respect to microwave radiation. To reduce temperature sensitivity and microwave losses, these materials are often used in the paraelectric regime, in bulk form, or used as thin films. For operation in the paraelectric regime, atomic substitutions are made in the perovskite structure to drive the Curie temperature to well below the minimum device operating temperature, moreover, additions are often made to improve the material figure of merit through reduction of losses. In both cases, such substitutions and additions lead to materials with significantly reduced tunability, for a given electric-field strength, that may result in poorer device performance especially at higher operating temperatures even though the material may have a higher figure of merit. Thin films, which at present appear to be the preferred configuration for fabrication of devices, are typically nearly temperature insensitive with significantly reduced values of both dielectric constant and tunability. While the reduced dielectric constant is useful from a device perspective, the reduced tunability results in reduction of electrode spacing, higher electric-field strengths (even though lower driving voltages may be used) and ultimately reduced power handling capability. We at the Army Research Laboratory, Sensors and Electron Devices Directorate, have been using a different approach to overcoming the various issues associated with electric-field tunable material and devices. From a material engineering perspective, we have fabricated highly electric-field tunable materials that possess lower dielectric constants, reasonable losses and properties that are nearly temperature insensitive over a large temperature range, -50 to 125 °C. Further, from a device engineering perspective, for enabling a low cost electronic scanning antenna technology, we have been developing a variable true time delay device structure and architecture that may provide significant advantages over a phase shifter technology. In this presentation, we will review, from an engineering perspective, material and device trade-offs, discuss these new highly electric-field tunable nearly temperature insensitive materials as well as compare phase shifter and variable true time delay architectures for achieving an affordable electronic scanning antenna technology.
10:00 AM - **W4.2/T4.2
Integrated BST Tunable Dielectrics for Frequency Agile GHz Applications.
Paul Clem 1 , Jennifer Sigman 1 , Patrick Finnegan 1 , Chris Nordquist 1
1 , Sandia National Laboratories, Albuquerque, New Mexico, United States
Show AbstractFor development of compact RF electronics with frequency agile properties, materials integration of low loss tunable dielectrics with high conductivity metals is necessary. Methods for integration of tunable dielectric [(Ba,Sr)TiO3, BST] thin films on substrates including silicon, alumina, silicates, and metal foils will be presented. Reducing atmosphere approaches to enable BST integration on base metal foils and electrodes will be discussed, including the interplay between metal reduction and oxide defect chemistry. In thin film form, epitaxial and columnar-grained BST films have been observed to display significantly higher permittivities and tunabilities than otherwise identically-processed randomly oriented, polycrystalline films. This effect will be discussed in relation to the grain size, grain morphology, and domain orientation of the BST films, as determined by microscopy, x-ray diffraction and Raman spectroscopy. Phase shift and Q results for interdigitated capacitors of these films in the 1-10 GHz range will be reported, along with approaches to more temperature-stable tunable capacitor properties. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy''s National Nuclear Security Administration under contract DE-AC04-94AL85000.
10:30 AM - W4.3/T4.3
Fabrication of Frequency Agile Microwave Circuits Using (Ba,Sr)TiO3 Thin Film Capacitors
Jennifer Sigman 1 , Paul Clem 1 , Chris Nordquist 1 , Patrick Finnegan 1
1 , Sandia National Laboratories, Albuquerque, New Mexico, United States
Show AbstractNew materials and new integration schemes are vital to the continued development and improvment cellular, satellite and radar communication systems. We report on our efforts to integrate tunable dielectric (Ba,Sr)TiO3 (BST) thin films into frequency agile microwave circuits. We focus on depositing BST on alumina and through-wafer via hole substrates. Using through-wafer via holes increases the variety of devices that can be realized, but adds complexity for materials integration because the via material is a copper-tungsten alloy. By controlling the processing parameters, namely temperature and oxygen partial pressure, we have successfully deposited quality BST on alumina and through wafer via hole substrates by chemical solution deposition without secondary phases. Initial phase shifter devices have also been successfully fabricated and tested. Both the film properties and device properties are discussed.
11:15 AM - **W4.4/T4.4
BST Technology for RF/Microwave Applications.
Robert York 1
1 , University of California - Santa Barbara, Santa Barbara, California, United States
Show AbstractSince the 1990s there has been significant progess in developing high-k, polar and non-polar materials such as (Ba,Sr)TiO3 (BST) and Bi1.5Zn1.0Nb1.5O7 (BZN). BST thin-films have been realized with properties that are especially attractive for high-frequency applications, including: High dielectric constant (200-300): useful for small-area bypass or AC decoupling capacitors Field-dependent permittivity: as much as 3:1 variation in permittivity or capacitance as a function of applied voltage, useful for tunable RF circuits such as phase-shifters, filters, and (VCOs).“Fast” polarization response: allows for rapid tuningGood breakdown fields: typically >1MV/cm, allowing for large bipolar voltage swings and hence good power handling.Reasonable Loss Tangents: typical loss tangents of tan δ < 0.02 up to 10GHz and higher.Combined with a simple manufacturing process and high-quality insulating substrates, BST-based voltage-variable capacitors (varactors) can provide a compelling alternative to semiconductor-based varactors for highly-integrated RF/Microwave circuits. Several companies now provide products for RF applications based on thin-film BST. This talk will review progress in this area, potential applications and RF insertion points in wireless communications, examples of commercial products, and remaining challenges.
11:45 AM - **W4.5/T4.5
Ferroelectric/electrode Interface: ab initio Description and Impact on the Film Properties.
Alexander Tagantsev 1 , Guido Gerra 1 , Nava Setter 1
1 IMX Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), Lausanne Switzerland
Show AbstractExperimental studies of ferroelectrics have provided ample evidence for the impact of the ferroelectric/electrode interface on different properties of ferroelectric capacitors. As theoretically demonstrated, it is this impact that can shift the transition temperature of ferroelectric thin films or impede the transition itself [1-4], smear anomalies (e.g., the singularity of the dielectric permittivity) associated with the phase transition [5,6], and promote ferroelectric switching[7]. However, despite an appreciable progress in the theoretical description of the impact of ferroelectric/electrode coupling on the properties of ferroelectric films, one is to face serious problems concerning the practical use of the results obtained. First, most of the results have been obtained in terms of the continuous Landau-Ginsburg phenomenological framework which has been used at spatial scales which are too small to justify its applicability. Second, the few relevant results of first principles calculations have been obtained for systems which are too small to be (at least presently) of practical interest.In this paper, first, we present the results of our ab initio theoretical treatment of the BaTi03/SrRu03 interface and of its impact on the ferroelectric properties of ultrathin ferroelectric thin films. Specifically, we demonstrate that in the case of metal-oxide electrodes a new mechanism of ferroelectric-polarization screening is possible. Within this mechanism, due to the ionic polarizability of the electrode, bound polarization charges can be screened “in situ” by the free charge carriers of the latter.In the second part of the talk, we formulate a phenomenological approach which, on one hand is free from the aforementioned applicability problem, and, on the other hand, enables the use o the results of ab initio calculations to model the properties of relatively thick ferroelectric films. [1] R. Kretschmer and K. Binder, Phys. Rev. B v.20, 1065 (1979).[2] J. Junquera and P. Ghosez, Nature v.422, 506-50(2003).[3] G. Gerra, A. K. Tagantsev, N. Setter, and K. Parlinski, Physical Review Letters v.96 (2006).[4] N. Sai, A. M. Kolpak, and A. M. Rappe, Phys. Review B v.72, 020101-4 (2005).[5] M. D. Glinchuk and A. N. Morozovska, J. of Phys. Conden. Matt. v.16, 3517-3531 (2004).[6] A. M. Bratkovsky and A. P. Levanyuk, Phys.Rev. Lett. v.94, 107601 (2005).[7] G. Gerra, A. K. Tagantsev, and N. Setter, Phys. Rev.Lett.v.94, 107602 (2005).
12:15 PM - **W4.6/T4.6
Aerosol Deposition Method for Low Temperature Ceramic Fabrications.
Takaaki Tsurumi 1 , Jun Akedo 2
1 Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo, Japan, 2 Advanced Manufacturing Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaragi, Japan
Show Abstract12:45 PM - W4.7/T4.7
Micro-contact Printed Thin Film Capacitors.
Song-Won Ko 1 , Hajime Nagata 1 , Eunki Hong 1 , Clive Randall 1 , Susan Trolier-McKinstry 1 , Pascal Pinceloup 2 , Mike Randall 2 , Aziz Tajuddin 2
1 Materials Science and Engineering, Penn State, University Park, Pennsylvania, United States, 2 , Kemet Electronics Corporation, Fountain Inn, South Carolina, United States
Show AbstractThere is an ongoing need to develop new technologies to enable further down-scaling of layer thicknesses in multilayer ceramic devices, particularly in multilayer capacitors (MLC). There are about 1012 MLC prepared annually. Currently, they are made by tape casting powder slurries, screen-printing, and laminating. In order to prepare a thin film version of such a capacitor, it is essential to demonstrate films with high dielectric constants (>1000) over a wide temperature range, stacking of these films into a multilayer configuration, and an inexpensive means of assembling the films. This paper will demonstrate chemical solution deposited BaTiO3 films on Ni foils with permittivities >1500 down to film thicknesses <150 nm with good temperature stability. Micro-contact printing of chemical solutions of both the dielectric and electrode layers was explored as an economical means of preparing patterned thin film-based MLC without requiring photolithography. For this purpose, methanol/acetic acid-based BaTiO3 solutions were spun onto polydimethylsiloxane stamps, printed onto substrates, pyrolyzed, and crystallized. Normal metal and oxide electrodes have both been investigated. The line edge roughness produced this way was on the order of a tenth of a micron, which should enable very small margins. The printed layer thickness was also very uniform. Multilayer stacking was also demonstrated. Consequently, microcontact printing appears to be an interesting alterative means of preparing MLC with layer thicknesses in the range of ≤0.2 μm.
Tuesday PM, November 28, 2006
Room 303 (Hynes)
2:30 PM - W5.1
Studies on Curvature Deformation Control of Bilayer Cantilever Fabricated by Surface Micromachining of SOI Wafer
Huang Yu-Ming 1 , Masayuki Sohgawa 1 , Minoru Noda 1 , Kaoru Yamashita 1 , Masanori Okuyama 1 , Haruo Noma 2
1 Graduate School of Engineering Science, Osaka university , Toyonaka Japan, 2 Media Information Science Laboratories, ATR , Keihanna Science City Japan
Show AbstractRecently it is much required to fabricate a stable and controllable cantilever with high precision for actuator and especially for basic structure of intelligent tactile sensor[1]. In this paper key issues are, 1) Si LSI process compatibility from viewpoints of cantilever material and its fabrication process, 2) controllability of curvature deformation of the cantilever, 3) comparison with finite element 3D simulation results.Fabricated cantilevers are bilayer of SiN(300nm)/Si(500-1000nm), Cr(150nm) /Si(500-1000nm), W(240nm) /Si(500-1000nm), respectively. All the bilayers show upper curvature deformation, as each top layer has a tensile stress compared to Si layer. The SOI substrate consists of Si (500-1000nm)/SiO2(BOX)(1000-1500nm)/Si(600-700um). Signal conditioning IC parts other than the cantilever can be co-integrated on the Si top layer or bottom Si substrate. Both SiN and W are friendly materials to Si process as interlayer insulator and interconnect plug material, respectively. Cr is very attractive because its linear coefficient of expansion is large, tensile stress is so high and very effective to make upper curvature, so it is applied to various MEMS devices. Fabrication process of the bilayer cantilever is as follows; 1) SiN film(300nm), Cr film(150nm), and W(240nm) are prepared on the SOI wafers by LPCVD at 780C, resistance heat evaporation, and RF sputtering at room temperature, respectively, 2) after window opening to SiO2(BOX) sacrificial layer by etching off the cantilever layer materials, wet etching of the BOX is done with HF or BHF solutions. 3) after vacuum drying or cooling drying, the etchant and water are removed thereafter cantilever structures are obtained. All the bilayered cantilevers show successfully upper curvature deformation. For example, cantilevers of SiN/Si, Cr/Si, and W/Si with length and width of 485um/95um, 200um/10um, and 485um/95um, show 204um, 150um, 300um, respectively. These means that actuation and tactile sensing are possible with the size of cantilever itself. The finite element analysis was done by bimetal model thermal stress analysis program from Ansys(Rel.10.0). It is found that the calculated values of curvature deformation are by an order smaller compared to the above experimental results, using previously reported material constants such as Young’s modulus, Poisson’s ratio and linear coefficient of expansion. This indicates that those of our films are different from the reported values. On the contrary, we think that it is possible to propose the material constants dependent on the each process prepared as the above. [1] K. Noda, K. Hoshino, K. Matsumoto, I. Shimoyama: 18th IEEE Int. Conf. on Micro Electro Mechanical Systems, Miami, Fulorida, USA, 2005.
2:45 PM - W5.2
MEMS Capacitive Switch Fabrication using Photodefinable Mixed Metal Oxide Dielectrics
Michael Romeo 1 , Guoan Wang 2 , John Papapolymerou 2 , Clifford Henderson 1
1 School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States, 2 School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractRF MEMS switches are good candidates to replace conventional GaAs FET and PIN diode switches used in RF and microwave systems. RF MEMS possess numerous potential advantages including negligible power consumption, low insertion loss, small size, and light weight. For most MEMS switches reported so far, the dielectric layer has typically been silicon nitride or silicon dioxide deposited using PECVD or HDICP CVD techniques. One focus of our research is to develop novel, low cost, versatile fabrication materials and methods for MEMS switch fabrication and packaging that can aid in producing reliable and economically attractive RF switches. In particular, recent progress on utilizing photo-definable metal-organic precursor thin films to directly deposit patterned dielectric pads in RF MEMS switches will be reported in this paper. The goal of this particular effort is to provide methods for reducing the high cost associated with using vacuum based CVD, ALD, or sputtering techniques used for dielectric deposition while also increasing the dielectric constant and variety of dielectric compositions available for use in such RF MEMS switches. Previously it was reported that photo-definable metal-organic materials could be used to fabricate the dielectric insulator used in capacitive MEMS switches, but these switches were found to suffer from reduced reliability due to stiction that occured when the switches were activated with the relatively high actuation voltages required for those earlier switch designs.This paper presents the first reliable capacitive RF MEMS switches fabricated with these new solution deposited, photodefinable dielectric materials which exhibit high electrical performance (Ebreakdown>100 MV/cm) and good reliability during cycling. In this dielectric deposition process, a photosensitive metal-organic precursor solution is spun on the substrate to form a thin, solid, amorphous precursor film. Upon UV exposure, the organic ligands of the precursor molecules are cleaved, resulting in the formation of an amorphous metal oxide. The remaining unexposed precursor material is subsequently washed away by rinsing with a developer solvent. In this work, a mixed oxide dielectric consisting of titanium and barium oxides (which possessed a k~10) was utilized. Clamped-clamped (air-bridge type) coplanar waveguide (CPW) switches were fabricated on high-resistivity silicon substrates using a simple four mask, low-temperature process which includes the use of the photo-definable mixed metal oxide materials. RF MEMS switches were made using both mixed oxide and silicon nitride dielectric pads, and comparisons of their electrical performance at frequencies up to 40 GHz will be discussed. Measured switch speeds of between 8.6 and 12.4µsec were measured during cycling tests for the current switch design and switches were cycled for more than 340 million cycles in an open air environment for the unpackaged switch without failure.
3:00 PM - **W5.3
Multi-domain and Multi-technology Integration for the Next Generation MNT Products.
Mark McNie 1 , Christopher Reeves 1 , Christopher Pickering 1 , Timothy Cox 1 , Tom Harvey 2 , Christian Bosshard 3 , Helmut Knapp 3
1 , QinetiQ Ltd., Malvern United Kingdom, 2 , Epigem Ltd., Redcar United Kingdom, 3 , CSEM, Alpnach Dorf Switzerland
Show Abstract3:30 PM - W5.4
Metal Insulator Semiconductor Mesostructured Fibers.
Fabien Sorin 1 4 , Ayman Abouraddy 2 , Ofer Shapira 3 2 , Jeff Viens 1 2 4 , Nick Orf 1 4 , John Joannopoulos 2 5 , Yoel Fink 1 2 4
1 Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 4 Center for Materials Science and Engineering, Massachusetts Institue of Technology, Cambridge, Massachusetts, United States, 2 Research Laboratory of Electronics, Massachusetts Institue of Technology, Cambridge, Massachusetts, United States, 3 Electrical Engineering and Computer Science, Massachusetts Institue of Technology, Cambridge, Massachusetts, United States, 5 Department of Physics, Massachusetts Institue of Technology, Cambridge, Massachusetts, United States
Show AbstractTo date, a barrier has existed between the processing approaches for producing electronic devices and those used for optical fibers. The former comprise a collection of elaborate wafer-based processes; while the latter rely on simpler thermal-drawing techniques. Recent discoveries have enabled the fabrication of mesoscale optoelectronic devices in fiber form, presenting for the first time the opportunity to realize semiconductor device functionalities at fiber-optic length scales, uniformity, and cost (Nature 431, 826 (2004), Opt. and Photon. News 15, 24 (2004)). Specifically, the combination of amorphous semiconductors, high glass transition temperature polymers, and low melting point metals into functional photodetecting fibers using conventional fiber drawing techniques was achieved. This led to the production of one-dimensional distributed light-sensing fibers that can detect light from any direction and at any point along their entire length (tens of meters). These devices represent an alternative to the current point photoconductors not only due to their low cost and ease of production, but also to their structure and geometry. While the individual fibers indeed function as distributed light-detecting elements, it is their ability to be assembled into fabrics and large area 2D grids or photodetecting fiber webs, made possible by their low weight and flexibility that is the main advantages of these devices. Large-scale optical–field measurements were recently performed using such geometric fiber constructs (Nature materials, 5, in Press (2006)), illustrating an example of such advantages. Similarly to the evolution of semiconductor technology, improvement of the performance and functionality of the new fiber devices is paired with the reduction of the active materials feature size and their density inside the fiber. We demonstrate in this work the first example of submicrometer photoconducting thin films processing into 3D structures inside a fiber device. Controlling the design, composition and thickness of the semiconducting films not only enables an improvement in the device performance but also brings spatial as well as spectral resolution to the light-detecting fibers. In particular, we built a fiber device with two semiconducting thin films each contacted by four electrodes, enabling the recognition and separation of two different wavelengths and up to eight directions of illumination. Applications include smart fabrics, large area optical and thermal detectors for healthcare monitoring of patients, chemicals detection, large-scale optical-field measurements, and ultra low-cost photovoltaic fibers.
3:45 PM - W5.5
Single-Mode Polymer Optical Fiber Sensors for Large Strain Applications.
Sharon Kiesel 1 , Kara Peters 1 , Tasnim Hassan 2 , Mervyn Kowalsky 2
1 Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, United States, 2 Department of Civil, Construction and Environmental Engineering, North Carolina State University, Raleigh, North Carolina, United States
Show AbstractThis paper characterizes an intrinsic, single-mode, polymer optical fiber (POF) sensor for use in large-strain applications such as civil infrastructures subjected to earthquake loading or systems with large shape changes such as morphing aircraft. Electrical resistance strain gages are reliable for steel structures only up to about 3% strain for cyclic loading conditions and are less reliable for concrete structures, particularly for strains above 1%. POFs, however, are more advantageous than even standard silica optical fibers for such applications due to their high fracture toughness, relative flexibility in bending, durability in harsh chemical and environmental conditions, and high elastic strain limit. Most importantly, POFs have a potential strain measurement range of 6-12% appropriate for civil structures where material strains can exceed 2% in reinforced concrete and 5% in steel. Recent improvements in manufacturing have allowed single-mode POFs to be produced which in turn offers interferometric sensing capabilities for high accuracy strain measurements. However, in order to apply such interferometric sensors the full opto-mechanical properties of the POF, including attenuation, must be calibrated in both the ranges of small deformations and large deformations. It is well known that POFs posses a higher attenuation compared to silica fibers in the wavelength range of interest (visible and infrared).The opto-mechanical response was formulated for the POF including a second-order (in strain) photoelastic effect as well as a second-order (in strain) solution for the deformation of the POF during loading. It is shown that four independent mechanical and opto-mechanical constants are required for the small deformation regime and six additional independent mechanical and opto-mechanical constants are required for the large deformation regime. The mechanical nonlinearity of a typical polymer optical fiber was experimentally measured in tension at various loading rates. Failure strain occurred between 22% and 36% for the various samples tested at a rate of 60 mm/min. The secant modulus of elasticity measured at small strains, roughly up to 2% strain, was measured to be ~4GPa whereas at larger strains, roughly up to 4.5% strain, the secant modulus was measured to be ~4.8GPa. Repeatable results were also obtained at loading rates ranging from 1 mm/min to 305 mm/min. As the loading rate was increased the yield strain increased, ranging from ~3.2% at 1mm/min to ~5% at 305 mm/min. The mechanical nonlinearity of the POF was compared to previous published results for silica fibers and shown to be significantly larger, further justifying the need to apply the large deformation model and parameters at strains above 1%. Finally, a Mach-Zender interferometer configuration was applied for the measurement of the appropriate opto-mechanical constants for tensile and transverse loading of the POF.
4:30 PM - W5.6
BCB Based Packaging for Low Actuation Voltage RF MEMS Devices.
Robert Plana 1 , David Peyrou 1 , Fabienne Pennec 1 , Patrick Pons 1 , Karim Yacine 1
1 Micro and Nanosystem, LAAS-CNRS, Toulouse France
Show Abstract4:45 PM - W5.7
Photodefinable Sacrificial Polycarbonate Materials & Methods for Microdevice Fabrication
Yueming Hua 1 , Clifford Henderson 1
1 School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractThe use of thermally sacrificial polymers in the fabrication of both microfluidic and microelectronic devices has been recently reported. In using such materials in a microfabrication process, the sacrificial polymer is first deposited in thin film form and then patterned into the shape of the desired structures which will later become air gaps, microchannels, or other void spaces in the final device. The patterned sacrificial material is then overcoated with a permanent structural material such as an inorganic glass (SiO2, SiN, etc.) or a thermally stable polymer (polyimide, etc.). This process can be repeated to build-up complex multi-layered devices such as multi-level microfluidic systems. The use of photodefinable sacrificial polymers simplifies this fabrication process significantly. Once device build-up is complete, the entire structure is heated to the decomposition temperature of the sacrificial polymer which causes clean decomposition of the polymer to gaseous by-products, thus leaving behind open cavities in the shape of the original sacrificial polymer structures. This sacrificial polymer technique was originally developed using poly(norbornene) sacrificial materials. Although these polymers decompose very cleanly, their decomposition temperature is above 400 ○C which can limit the types of materials and structures that can be integrated with the process. The high decomposition temperature can cause decomposition of substrate and overcoat materials and thermal flow or deformation of structures. Therefore, recently sacrificial materials and processes based on polycarbonates have been developed which can be used at substantially lower decomposition temperatures. Originally, poly(propylene carbonate) was utilized as a sacrificial material for demonstration of polycarbonates in this application. However, this polymer exhibits substantial thermal deformation during processing due to its low glass transition temperature which can distort features and limit the lithographic resolution of such materials. Therefore, polycarbonates with improved resistance to thermal flow were developed by producing semi-crystalline polymers and polymers with a higher Tg. However, even these improved sacrificial polycarbonates did not provide sufficient film integrity to survive some microfabrication processes such as e-beam evaporation and extended electroplating for metal deposition. Therefore, recently we have developed a series of new cross-linkable polycarbonate sacrificial materials that can provide improved film stability and thermal flow resistance. End group functionalized polycarbonates that can be cross-linked after thin film formation were synthesized by end-capping polycarbonate oligomers and polymers using both methacryloyl chloride and cyclic carbonate reagents. This paper presents an update on these new cross-linkable polycarbonates, their properties, their processing characteristics, and device application examples.
5:00 PM - **W5.8
Above-IC Bulk Acoustic Wave Technology for Wireless Applications.
Marc-Alexandre Dubois 1
1 RF & piezo components, CSEM, Neuchatel Switzerland
Show Abstract5:30 PM - W5.9
Integration of PZT on SOI Wafers: Increasing Piezoelectric Film Thickness for Providing a Wide Range of Ultrasonic MEMS Applications.
Brahim Belgacem 1 , Florian Calame 1 , Paul Muralt 1
1 Ceramics Laboratory, EPFL, Lausanne Switzerland
Show Abstract5:45 PM - W5.10
Science and Technology of Piezoelectric/Diamond Hybrid Heterostructures for High Performance MEMS/NEMS Devices
Sudarsan Srinivasan 1 , Jon Hiller 2 , Bernd Kabius 2 , Orlando Auciello 1 3
1 Materials Science Division, Argonne National Laboratory, Argonne, Illinois, United States, 2 Center for Electron Microscopy, Argonne National Laboratory, Argonne, Illinois, United States, 3 Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois, United States
Show AbstractNovel microelectromechanical and nanoelectromechanical system (MEMS/NEMS) devices, including sensors and actuators represent a technological revolution similar to the microelectronics revolution of the 20th Century. Development of these new generation multifunctional devices involves new materials, dissimilar materials integration strategies, and micro and nanofabrication processing techniques for optimum device performance. Most MEMS devices are currently based on silicon because of the available surface micromachining technology. However, the poor mechanical and tribological properties of Si are not suitable for high-performance Si-based MEMS devices. Alternatively, a novel ultra-nano crystalline diamond (UNCD) material developed in thin film form at Argonne exhibits exceptional mechanical and tribological properties that make UNCD a suitable material for a new generation of high-performance MEMS/NEMS devices. Piezoelectric-based MEMS attracts much attention due to their high sensitivity and low electrical noise in sensing applications and high-force output in actuation applications. Piezoelectric Pb(ZrxTi1-x)O3 (PZT) thin films have been intensively investigated over the past decade due to its potential applications in a wide variety of devices, such as non-volatile ferroelectric memories and piezoelectrically actuated MEMS/NEMS devices, which can be actuated at comparatively lower voltages (5-10 V) to those actuated by electrostatic action that required higher voltages. Therefore, the integration of functional PZT thin films with the UNCD-based MEMS/NEMS structures opens up the tantalizing possibility of advanced MEMS/NEMS devices. However, the integration of PZT and UNCD is challenging, mainly due to the PZT/UNCD interface and the need to grow PZT at high temperature in oxygen in the presence of a carbon-based material such as diamond. We will review in this paper the fundamental and applied materials science performed in our laboratory to achieve integration of PZT as a piezoelectric actuation material and UNCD as a mechanically superior platform for MEMS/NEMS, and the development of fabrication processes to produce high-performance hybrid PZT/UNCD MEMS.NEMS devices. We will present data and a movie showing the first UNCD MEMS cantilever structure actuated by low voltage (5 V) PZT piezo actuator, which exhibited robust performance up to 1 billion cycles.
Symposium Organizers
Juan C. Nino University of Florida
Fred Roozeboom NXP Research
Susan Trolier-McKinstry The Pennsylvania State University
Paul Muralt Swiss Federal Institute of Technology EPFL
David LaVan Yale University
W6: Magnetic Components
Session Chairs
Wednesday AM, November 29, 2006
Room 303 (Hynes)
10:00 AM - **W6.1
Self-Assembled Nanostructures in Epitaxial Oxide Films
Igor Levin 1
1 , NIST, Gaithersburg, Maryland, United States
Show AbstractEpitaxial self-assembling of chemically dissimilar but lattice matched phases on a single crystal substrate provides a promising way of generating multiferroic nanostructures with enhanced magneto-electric interactions. Additionally, this approach can be used to generate nanoscale ferroelectric features (e.g. nanorods) embedded in various matrices thereby providing excellent samples for studying the effects of constraints on ferroelectric phase transitions in low-dimensions. The epitaxial self-assembling appears to be dominated by the elastic interactions among the component phases which, under the appropriate growth conditions, dominate over the kinetic factors and determine the resulting phase morphologies and arrangements. In that case, the morphological characteristics of the nanostructures can be controlled by modifying the stress state in the film by using, for example, different substrate orientations or phase fractions. In the present talk, examples of functional self-assembled nanostructures in several metal oxide systems will be discussed.
10:30 AM - W6.2
Ferrite Plating By Spin Spray Technique Using Iron Dextran Complex.
Subramani Ailoor Krishnan 1 , Matsushita Nobuhiro 1 , Watanabe Tomoiki 1 , Tada Masaru 2 , Abe Masanori 2 , Yohimura Masahiro 1
1 Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama Japan, 2 Department of Physical Electronics, Tokyo Institute of Technology, Tokyo Japan
Show Abstract10:45 AM - W6.3
Technological Study of Ni-Zn Ferrite Film on IC for Compatibility Improvement
Liang Zheng 1 , Huibin Qin 1 , Junming Xu 1 , Ji Hu 1 , Jian Liu 1
1 School of electronics and information, Hangzhou Dianzi university, Hangzhou, Zhejiang, China
Show Abstract11:30 AM - **W6.4
Power and Radio Frequency Inductors Using a Hybrid Ferrite-flex Foil Technology.
Martin Gijs 1
1 Inst of Microelectricons and Microsystems, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne Switzerland
Show AbstractA hybrid technology for the realization of three-dimensional miniaturized power inductors is presented. Our devices consist of planar Cu coils on polyimide substrates, and mm-size ferrite magnetic cores, obtained by three-dimensional micro-patterning of ferrite wafers using powder blasting. The coils are realized using an in-house developed high-resolution polyimide spinning and Cu electroplating process. Winding widths down to 5 μm have been obtained and total device volumes are ranging between 1.5 and 10 mm3. Inductive and resistive properties are characterized as a function of frequency; inductance values in the 100 μH range have been obtained. We also have realized millimetre-size RF inductors on silicon using a polyimide mould - copper electroplating coil technology. Subsequently the coils are assembled with magnetic cover plates of commercially available bulk Ni-Zn ferrites of high resistivity. Using the magnetic flux-amplifying ferrite plates, we obtain a 40 % enhancement of the inductance and a 25 % enhancement of the quality factor (Q=10-20) for frequencies up to 0.2 GHz. Our results indicate the potential of using bulk ferrites for RF applications in a hybrid inductor assembly process. 1.M. Saidani and M.A.M. Gijs, Cubic millimetre power inductor fabricated in batch-type wafer technology, J. Microelectromechanical Syst. 12, 172 (2003).2.M. Saidani and M.A.M. Gijs, High-quality RF inductors on silicon using a hybrid ferrite technology, Appl. Phys. Lett. 84, 4496 (2004).
12:00 PM - W6.5
High Frequency Properties of Layered Ferromagnetic Thin Films for RF-applications in the GHz Range such as Toroidal Microinductors or Transformers.
Andreas Gerber 1 , Clemens Schmutz 1 , Eckhard Quandt 1
1 Smart Materials, Research Center caesar, Bonn Germany
Show Abstract12:15 PM - W6.6
Towards the Integration of Barium Ferrite Sputtered Films for Coplanar Isolators and Circulators in the Millimeter Wave Range.
A.S. Dehlinger 1 2 3 , Martine Le Berre 2 , V. Larrey 1 , E. Benevent 1 3 , D. Vincent 3 , D. Givord 4 , J.J. Rousseau 3
1 , Radiall, Voiron France, 2 LPM, INSA Lyon, Villeurbanne France, 3 DIOM, Univ. J. Monnet, Saing-Etienne France, 4 LLN, CNRS, Grenoble France
Show Abstract