A GaN–SiC hybrid material for high-frequency and power electronics

Abstract

We demonstrate that 3.5% in-plane lattice mismatch between GaN (0001) epitaxial layers and SiC (0001) substrates can be accommodated without triggering extended defects over large areas using a grain-boundary-free AlN nucleation layer (NL). Defect formation in the initial epitaxial growth phase is thus significantly alleviated, confirmed by various characterization techniques. As a result, a high-quality 0.2-lm thin GaN layer can be grown on the AlN NL and directly serve as a channel layer in power devices, like high electron mobility transistors (HEMTs). The channel electrons exhibit a state-of-the-art mobility of >2000 cm 2 /V-s, in the AlGaN/GaN heterostructures without a conventional thick C-or Fe-doped buffer layer. The highly scaled transistor processed on the heterostructure with a nearly perfect GaN-SiC interface shows excellent DC and microwave performances. A peak RF power density of 5.8 W/mm was obtained at V DSQ ¼ 40 V and a fundamental frequency of 30 GHz. Moreover, an unpassivated 0.2-lm GaN/AlN/SiC stack shows lateral and vertical breakdowns at 1.5 kV. Perfecting the GaN-SiC interface enables a GaN-SiC hybrid material that combines the high-electron-velocity thin GaN with the high-breakdown bulk SiC, which promises further advances in a wide spectrum of high-frequency and power electronics. Published by AIP Publishing.

Epitaxial GaN using Ga(NMe2)3 and NH3 plasma by atomic layer deposition

“…6 Therefore, an AlN buffer layer is used to facilitate GaN growth. [7][8][9] Currently, thin films of electronic grade epitaxial GaN are deposited by chemical vapor deposition (CVD) processes using trimethylgallium (TMG) and ammonia (NH 3 ) at temperatures between 800-1000 1C. 10 The high deposition temperatures are required to obtain highly crystalline films but also to overcome the poorly suited precursor combination of TMG and NH 3 , which leads to high N/Ga precursor ratios of 10 3 .…”

Влияние слоя нанопористого кремния на практическую реализацию и особенности эпитаксиального роста слоев GaN на темплейтах SiC/por-Si/c-Si

“…Исходя из свойств упомянутых материалов и текущего развития технологий роста можно говорить о том, что гибридные гетероэпитаксиальные структуры GaN/SiC будут иметь превосходство в коммерческих устройствах, в которых производительность имеет первостепенное значение [5].…”

Epitaxial GaN using Ga(NMe2)3 and NH3 Plasma by Atomic Layer Deposition

“…6 Therefore, an AlN buffer layer is used to facilitate GaN growth. 7,8,9 Currently, thin films of electronic grade epitaxial GaN are deposited by chemical vapor deposition (CVD) processes using trimethylgallium (TMG) and ammonia (NH3) at temperatures between 800-1000 C. 10 The high deposition temperatures are required to obtain highly crystalline films but also to overcome the poorly suited precursor combination of TMG and NH3, which leads to high N/Ga precursor ratios of 10 3 .…”