On the performance of GaN‐on‐Silicon, Silicon‐Carbide, and Diamond substrates
Anwar Jarndal, L. Arivazhagan, D. Nirmal
Abstract
In this article, threading dislocations and its impact on the electrical and thermal performance of GaN-on-Diamond (Dia), -SiC, and -Si high electron mobility transistor (HEMT) has been investigated. TCAD simulation of GaN-HEMT is performed with various buffer traps to mimic the lattice mismatch/dislocation density at GaN/Si, GaN/SiC, and GaN/Dia interface. It has been found that, the dislocations not only induce traps, but also degrade the thermal conductivity of the GaN-buffer. This accordingly could deteriorate the thermal characteristic of GaN-on-Dia, which has higher lattice mismatch with respect to GaN-on-SiC. This investigation showed that the growth process of GaN-on-Dia should be optimized in order to reduce the threading dislocations. This accordingly could dramatically further improve its outstanding thermal characteristics with respect to GaN-on-SiC and GaN-on-Si devices.