Tutorial EL02—Mixed Dimensional Heterostructures from Fundamentals to Device Applications

Instructors: Jeehwan Kim, Massachusetts Institute of Technology; Abdallah Ougazzaden, Georgia Tech Lorraine; Kunook Chung, Ulsan National Institute of Science and Technology; Kyusang Lee, University of Virginia

The tutorial focuses on the fundamentals and applications of heterogeneously integrated structures using 1D, 2D and 3D materials from the growth of 3D materials on 2D materials, and various liftoff technologies to heterogeneous integration of electronic/optoelectronic devices.

8:30 am
Epitaxial Growth of 2D and 3D Materials
Abdallah Ougazzaden, Georgia Tech Lorraine

The instructor will provide an overview regarding the epitaxial growth of Nitride-based semiconductor materials by MOVPE including GaN and h-BN, and design device structures for optoelectronic devices. In addition, Ougazzaden will cover the fabrication of nanostructures and materials characterization. The epitaxial growth of 3D and 2D materials and their characterization is the basis of fabrication of a heterointegration system for various device applications.

9:30 am BREAK

10:00 am
Remote Epitaxy—Growth of 3D Materials on 2D Materials
Jeehwan Kim, Massachusetts Institute of Technology

The instructor will discuss a new epitaxy liftoff technique so-called remote epitaxy that can produce freestanding semiconductor membranes. Discussion will include (1) Remote epitaxy mechanism, (2) High-yield peeling mechanism, (3) Reusability of the substrates, (4) Economic aspect of remote epitaxy, and (5) Heterointergration of 3D materials with 2D materials for advanced heterostructuring.

11:00 am
Liftoff Technology Toward Heterogeneous Integration
Kyusang Lee, University of Virginia

The layer-transfer technique has been in development for over a decade as a cost-saving strategy as well as a means of enabling heterointegration of dissimilar functional materials and flexible electronics. The instructor will review three major layer-transfer technologies, which are chemical liftoff, optical liftoff and mechanical liftoff. However, most conventional layer-transfer methods lead to various issues such as surface roughening that limits substrate reusability. Instructor will introduce new liftoff technology including a two-dimensional layer-transfer method that permits rapid mechanical release of epilayers, leaving behind an atomically smooth released surface without additional process to recondition the surface. Liftoff technology holds promise to unlock cost-efficient growth/transfer/stacking of high-quality semiconductors and their heterointegration without lattice matching restriction as well as substrate cost restrictions.

1:30 pm
Heteoepitaxy on Graphene for Transferable and Flexible Optoelectronics
Kunook Chung, Ulsan National Institute of Science and Technology

High device performance has been expected using a single-crystalline inorganic compound semiconductor because of its high radiative recombination rate and mobility, as well as its excellent thermal and mechanical characteristics. Nevertheless, the high growth temperatures of single-crystalline inorganic semiconductors make it difficult to use a conventional plastic substrate with a low melting temperature. In addition, a continuous, rigid inorganic film has little tolerance for mechanical deformation. These obstacles can be overcome using inorganic microstructures and nanostructures grown on two-dimensional layered materials, such as graphene and hexagonal boron nitride as a flexible substrate, which exhibit high-temperature compatibility and good mechanical flexibility. The instructor will review the current state-of-the-art technology of inorganic compound semiconductor heteroepitaxy on the 2D films for the transferable and flexible inorganic optoelectronics toward next-generation wearable devices and integrated devices with electronics.