Low Leakage Current and High Breakdown Field AlGaN/GaN MIS-HEMTs Using PECVD-SiN x as a Gate Dielectric

Xiaohui Gao; Hui Guo; Rui Wang; Danfeng Pan; Peng Chen; Dunjun Chen; Hai Lu; Rong Zhang; Youdou Zheng

doi:10.3390/mi13091396

Low Leakage Current and High Breakdown Field AlGaN/GaN MIS-HEMTs Using PECVD-SiN x as a Gate Dielectric

Micromachines (Basel). 2022 Aug 26;13(9):1396. doi: 10.3390/mi13091396.

Authors

Xiaohui Gao¹, Hui Guo¹, Rui Wang¹, Danfeng Pan^{1

2}, Peng Chen¹, Dunjun Chen¹, Hai Lu¹, Rong Zhang¹, Youdou Zheng¹

Affiliations

¹ Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
² Microfabrication and Integration Technology Center, Nanjing University, Nanjing 210023, China.

Abstract

In this paper, SiNx film deposited by plasma-enhanced chemical vapor deposition was employed as a gate dielectric of AlGaN/GaN high electron mobility transistors (HEMTs). We found that the NH₃ flow during the deposition of SiNx can significantly affect the performances of metal-insulator-semiconductor (MIS) HEMTs. Compared to that without using NH₃ flow, the device with the optimized NH₃ flow exhibited three orders of magnitude lower gate leakage current, two orders of magnitude higher ON/OF drain current ratio, and an increased breakdown field by 69%. In addition, an in situ N₂ plasma surface treatment prepared prior to SiNx deposition can further improve DC performances of MIS-HEMTs to a very low gate leakage current of 10^-9 mA/mm and a high ON/OFF drain current ratio up to 10⁹ by reducing the interface state density. These results demonstrate the great potential for using PECVD-SiNx as a gate dielectric in GaN-based MIS-HEMTs.

Keywords: AlGaN/GaN; MIS-HEMTs; PECVD-SiNx; breakdown field; in situ plasma treatment.

Abstract

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