April 7 - 11, 2025
Seattle, Washington
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2025 MRS Spring Meeting & Exhibit
EL11.07.15

Crystal Growth and Characterization of Ta0.8Hf0.2C, an Ideal Substrate for Al/GaN High Power Electronics

When and Where

Apr 9, 2025
5:00pm - 7:00pm
Summit, Level 2, Flex Hall C

Presenter(s)

Co-Author(s)

Evan Crites1,Joshua Hummel1,Satya Kushwaha1,MVS Chandrashekhar2,Michael Spencer2,Tyrel McQueen1

Johns Hopkins University1,Morgan State University2

Abstract

Evan Crites1,Joshua Hummel1,Satya Kushwaha1,MVS Chandrashekhar2,Michael Spencer2,Tyrel McQueen1

Johns Hopkins University1,Morgan State University2
Al/GaN is a wide bandgap semiconductor utilized in high power electronics including blue LEDs and transistors. Its production most commonly consists of growth on sapphire or Si substrates. However, this does not enable low-defect-density films at the highest performing compositions near Al0.6Ga0.4N. Here we report the first multi-mm-scale single crystal growth of Ta0.8Hf0.2C, a cubic material with a lattice parameter a = 3.143 Å, nearly optimally lattice matched to Al0.6Ga0.4N along the (111) direction. Growth of Ta0.8Hf0.2C, an ultrahigh temperature ceramic material (melting point ~3900 °C), was enabled through a new high-power laser pedestal furnace. Electrical and thermal properties from 2-300 K, and mechanical properties at room temperature will be discussed. Progress towards epi-ready surface preparations will also be presented.

Acknowledgements: We acknowledge helpful discussions with Nancy Haegel, Brooks Tellekamp, Patrick Hopkins, Jessica McChesney, Vladan Stevanovic, Andriy Zakutayev, Kirstin Alberi, Katherine Jungjohann, John Simon, Heather Splawn, Jacob Leach, and the rest of the APEX team. We further acknowledge Maxime Seigler for help acquiring single crystal data.

Funding: This work was funded by APEX, A Center for Power Electronics Materials and Manufacturing Exploration, a DOE Energy Frontier Research Center (EFRC), under award #DE-AC36-08GO28308. This work made use of the bulk crystal growth facility of the Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM), which is supported by the National Science Foundation under Cooperative Agreement No. DMR-2039380.

Keywords

chemical vapor deposition (CVD) (chemical reaction)

Symposium Organizers

Robert Kaplar, Sandia National Laboratories
Filip Tuomisto, University of Helsinki
Motoaki Iwaya, Meijo University
Sriram Krishnamoorthy, University of California, Santa Barbara

Symposium Support

Silver
Taiyo Nippon Sanso

Session Chairs

Robert Kaplar
Sriram Krishnamoorthy

In this Session