中国物理B ›› 2018, Vol. 27 ›› Issue (9): 97309-097309.doi: 10.1088/1674-1056/27/9/097309

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Effect of SiN: Hx passivation layer on the reverse gate leakage current in GaN HEMTs

Sheng Zhang(张昇), Ke Wei(魏珂), Yang Xiao(肖洋), Xiao-Hua Ma(马晓华), Yi-Chuan Zhang(张一川), Guo-Guo Liu(刘果果), Tian-Min Lei(雷天民), Ying-Kui Zheng(郑英奎), Sen Huang(黄森), Ning Wang(汪宁), Muhammad Asif, Xin-Yu Liu(刘新宇)   

  1. 1 School of Advanced Materials and Nanotechnology, Xi'dian University, Xi'an 710071, China;
    2 High-Frequency High-Voltage Device and Integrated Circuits Center, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
  • 收稿日期:2018-03-28 修回日期:2018-05-25 出版日期:2018-09-05 发布日期:2018-09-05
  • 通讯作者: Ke Wei E-mail:weike@ime.ac.cn

Effect of SiN: Hx passivation layer on the reverse gate leakage current in GaN HEMTs

Sheng Zhang(张昇)1,2, Ke Wei(魏珂)2, Yang Xiao(肖洋)1, Xiao-Hua Ma(马晓华)1, Yi-Chuan Zhang(张一川)2, Guo-Guo Liu(刘果果)2, Tian-Min Lei(雷天民)1, Ying-Kui Zheng(郑英奎)2, Sen Huang(黄森)2, Ning Wang(汪宁)2, Muhammad Asif2, Xin-Yu Liu(刘新宇)2   

  1. 1 School of Advanced Materials and Nanotechnology, Xi'dian University, Xi'an 710071, China;
    2 High-Frequency High-Voltage Device and Integrated Circuits Center, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
  • Received:2018-03-28 Revised:2018-05-25 Online:2018-09-05 Published:2018-09-05
  • Contact: Ke Wei E-mail:weike@ime.ac.cn

摘要:

This paper concentrates on the impact of SiN passivation layer deposited by plasma-enhanced chemical vapor deposition (PECVD) on the Schottky characteristics in GaN high electron mobility transistors (HEMTs). Three types of SiN layers with different deposition conditions were deposited on GaN HEMTs. Atomic force microscope (AFM), capacitance-voltage (C-V), and Fourier transform infrared (FTIR) measurement were used to analyze the surface morphology, the electrical characterization, and the chemical bonding of SiN thin films, respectively. The better surface morphology was achieved from the device with lower gate leakage current. The fixed positive charge Qf was extracted from C-V curves of Al/SiN/Si structures and quite different density of trap states (in the order of magnitude of 1011-1012 cm-2) was observed. It was found that the least trap states were in accordance with the lowest gate leakage current. Furthermore, the chemical bonds and the %H in Si-H and N-H were figured from FTIR measurement, demonstrating an increase in the density of Qf with the increasing %H in N-H. It reveals that the effect of SiN passivation can be improved in GaN-based HEMTs by modulating %H in Si-H and N-H, thus achieving a better Schottky characteristics.

关键词: SiN passivation, the gate leakage current, Qf, FTIR

Abstract:

This paper concentrates on the impact of SiN passivation layer deposited by plasma-enhanced chemical vapor deposition (PECVD) on the Schottky characteristics in GaN high electron mobility transistors (HEMTs). Three types of SiN layers with different deposition conditions were deposited on GaN HEMTs. Atomic force microscope (AFM), capacitance-voltage (C-V), and Fourier transform infrared (FTIR) measurement were used to analyze the surface morphology, the electrical characterization, and the chemical bonding of SiN thin films, respectively. The better surface morphology was achieved from the device with lower gate leakage current. The fixed positive charge Qf was extracted from C-V curves of Al/SiN/Si structures and quite different density of trap states (in the order of magnitude of 1011-1012 cm-2) was observed. It was found that the least trap states were in accordance with the lowest gate leakage current. Furthermore, the chemical bonds and the %H in Si-H and N-H were figured from FTIR measurement, demonstrating an increase in the density of Qf with the increasing %H in N-H. It reveals that the effect of SiN passivation can be improved in GaN-based HEMTs by modulating %H in Si-H and N-H, thus achieving a better Schottky characteristics.

Key words: SiN passivation, the gate leakage current, Qf, FTIR

中图分类号:  (III-V semiconductors)

  • 73.61.Ey
73.61.-r (Electrical properties of specific thin films) 72.80.Ey (III-V and II-VI semiconductors) 73.40.Qv (Metal-insulator-semiconductor structures (including semiconductor-to-insulator))