Hole Injection Effect and Dynamic Characteristic Analysis of Normally Off p-GaN HEMT with AlGaN Cap Layer on Low-Resistivity SiC Substrate
Hsiang-Chun Wang,
Chia-Hao Liu,
Chong-Rong Huang,
Hsien-Chin Chiu,
Hsuan-Ling Kao,
Xinke Liu
Affiliations
Hsiang-Chun Wang
College of Materials Science and Engineering, Shenzhen University–Hanshan Normal University Postdoctoral Workstation, Shenzhen University, Shenzhen 518060, China
Chia-Hao Liu
Department of Electronic Engineering, Chang Gung University, Taoyuan 333, Taiwan
Chong-Rong Huang
Department of Electronic Engineering, Chang Gung University, Taoyuan 333, Taiwan
Hsien-Chin Chiu
Department of Electronic Engineering, Chang Gung University, Taoyuan 333, Taiwan
Hsuan-Ling Kao
Department of Electronic Engineering, Chang Gung University, Taoyuan 333, Taiwan
Xinke Liu
Key Laboratory of Optoelectronic Devices and Systems, Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
A p-GaN HEMT with an AlGaN cap layer was grown on a low resistance SiC substrate. The AlGaN cap layer had a wide band gap which can effectively suppress hole injection and improve gate reliability. In addition, we selected a 0° angle and low resistance SiC substrate which not only substantially reduced the number of lattice dislocation defects caused by the heterogeneous junction but also greatly reduced the overall cost. The device exhibited a favorable gate voltage swing of 18.5 V (@IGS = 1 mA/mm) and an off-state breakdown voltage of 763 V. The device dynamic characteristics and hole injection behavior were analyzed using a pulse measurement system, and Ron was found to increase and VTH to shift under the gate lag effect.
