中国物理B ›› 2011, Vol. 20 ›› Issue (5): 57301-057301.doi: 10.1088/1674-1056/20/5/057301

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

Investigation of current transport parameters of Ti/4H–SiC MPS diode with inhomogeneous barrier

宋庆文, 张玉明, 张义门, 陈丰平, 汤晓燕   

  1. School of Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of Ministry of Education, Xidian University, Xi'an 710071, China
  • 收稿日期:2010-10-24 修回日期:2010-12-11 出版日期:2011-05-15 发布日期:2011-05-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 61006060) and the 13115 Innovation Engineering of Shanxi Province of China (Grant No. 2008ZDKG-30).

Investigation of current transport parameters of Ti/4H–SiC MPS diode with inhomogeneous barrier

Song Qing-Wen (宋庆文), Zhang Yu-Ming (张玉明), Zhang Yi-Men (张义门), Chen Feng-Ping (陈丰平), Tang Xiao-Yan (汤晓燕)   

  1. School of Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of Ministry of Education, Xidian University, Xi'an 710071, China
  • Received:2010-10-24 Revised:2010-12-11 Online:2011-05-15 Published:2011-05-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 61006060) and the 13115 Innovation Engineering of Shanxi Province of China (Grant No. 2008ZDKG-30).

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摘要： The current transport parameters of 4H–SiC merged PiN Schottky (MPS) diode are investigated in a temperature range of 300–520 K. Evaluation of the experimental current–voltage (I–V) data reveals the decrease in Schottky barrier height Φb but an increase in ideality factor n, with temperature decreasing, which suggests the presence of an inhomogeneous Schottky barrier. The current transport behaviours are analysed in detail using the Tung's model and the effective area of the low barrier patches is extracted. It is found that small low barrier patches, making only 4.3% of the total contact, may significantly influence the device electrical characteristics due to the fact that a barrier height of 0.968 eV is much lower than the average barrier height 1.39 eV. This shows that ion implantation in the Schottky contact region of MPS structure may result in a poor Ti/4H–SiC interface quality. In addition, the temperature dependence of the specific on-resistance (Ron - sp), T2.14, is determined between 300 K and 520 K, which is similar to that predicted by a reduction in electron mobility.

Abstract: The current transport parameters of 4H–SiC merged PiN Schottky (MPS) diode are investigated in a temperature range of 300–520 K. Evaluation of the experimental current–voltage (I–V) data reveals the decrease in Schottky barrier height Φb but an increase in ideality factor n, with temperature decreasing, which suggests the presence of an inhomogeneous Schottky barrier. The current transport behaviours are analysed in detail using the Tung's model and the effective area of the low barrier patches is extracted. It is found that small low barrier patches, making only 4.3% of the total contact, may significantly influence the device electrical characteristics due to the fact that a barrier height of 0.968 eV is much lower than the average barrier height 1.39 eV. This shows that ion implantation in the Schottky contact region of MPS structure may result in a poor Ti/4H–SiC interface quality. In addition, the temperature dependence of the specific on-resistance (Ron - sp), T2.14, is determined between 300 K and 520 K, which is similar to that predicted by a reduction in electron mobility.

Key words: 4H–SiC, MPS, barrier inhomogeneity, specific on-resistance

中图分类号:  (Surface double layers, Schottky barriers, and work functions)

  • 73.30.+y
73.40.Sx (Metal-semiconductor-metal structures) 73.50.-h (Electronic transport phenomena in thin films)