Optimal layer thickness and junction temperature of GaN HEMTs based on bias-dependent non-uniform heat source model
Abstract
Accurate thermal simulation of thermal is crucial for designing reliable gallium nitride high electron mobility transistors (GaN HEMTs). Thermal analysis models that assume a uniform heat source neglect the non-uniformity and bias dependence of the heat source in the channel region, which leads to inaccurate device junction temperature and other parameter predictions. Herein, we adopt a framework of a bias-dependent non-uniform heat source model and perform detailed thermal simulations of the near-junction region of GaN HEMTs. Results show that a uniform heat source model yields an optimal GaN thickness of 2.4 μm; whereas under bias-dependent non-uniform heat sources, it remains 2.4 μm at Vg = 2 V, Vd = 3.8 V but increases to 3.1 μm at Vg = −1 V, Vd = 6.25 V. Notably, under identical power dissipation, devices on a high-thermal-conductivity diamond substrate in the saturated region exhibit a junction temperature of 377.8 K, higher than the 360.37 K observed for a low-thermal-conductivity SiC substrate in the linear region. This difference arises from heat distribution and heat flow paths related to device bias. These results provide a theoretical reference for the thermal design of high-performance GaN-based devices.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (8)
Dan Wu
Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, State Key Laboratory Breeding Base of Eco-Environments and Bio-Resources of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University
Bing-Yu Gan
Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology 1 , Changsha 410114,
Qi Luo
Guangdong Provincial Key Laboratory of Chinese Medicine Pharmaceutics, School of Traditional Chinese Medicine
Si-Yi Zhang
Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology 1 , Changsha 410114,
Hai-Qing Xie
Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology 1 , Changsha 410114,
Zhi-Qiang Fan
Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology 1 , Changsha 410114,
Xuan-Hao Cao
Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology 1 , Changsha 410114,
Xue-Kun Chen
School of Mathematics and Physics, University of South China 2 , Hengyang 421001,