中国物理B ›› 2011, Vol. 20 ›› Issue (8): 87305-087305.doi: 10.1088/1674-1056/20/8/087305

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Al/Ti/4H–SiC Schottky barrier diodes with inhomogeneous barrier heights

王悦湖, 张义门, 张玉明, 宋庆文, 贾仁需   

  1. School of Microelectronics and Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, China
  • 收稿日期:2010-12-06 修回日期:2011-03-01 出版日期:2011-08-15 发布日期:2011-08-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 60876061) and the Key Laboratory Science Foundation (Grant No. 20090C1403).

Al/Ti/4H–SiC Schottky barrier diodes with inhomogeneous barrier heights

Wang Yue-Hu(王悦湖)†,Zhang Yi-Men(张义门),Zhang Yu-Ming(张玉明), Song Qing-Wen(宋庆文),and Jia Ren-Xu(贾仁需)   

  1. School of Microelectronics and Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, China
  • Received:2010-12-06 Revised:2011-03-01 Online:2011-08-15 Published:2011-08-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 60876061) and the Key Laboratory Science Foundation (Grant No. 20090C1403).

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摘要： This paper investigates the current—voltage (I—V) characteristics of Al/Ti/4H—SiC Schottky barrier diodes (SBDs) in the temperature range of 77 K—500 K, which shows that Al/Ti/4H—SiC SBDs have good rectifying behaviour. An abnormal behaviour, in which the zero bias barrier height decreases while the ideality factor increases with decreasing temperature (T), has been successfully interpreted by using thermionic emission theory with Gaussian distribution of the barrier heights due to the inhomogeneous barrier height at the Al/Ti/4H—SiC interface. The effective Richardson constant A*=154 A/cm2·,K2 is determined by means of a modified Richardson plot ln(I0/T2)-(qσ)2/2(kT)2 versus q/kT, which is very close to the theoretical value 146 A/cm2·,K2.

关键词: Schottky contact, 4H—SiC, barrier height inhomogeneity, temperature

Abstract: This paper investigates the current--voltage ($I$--$V$) characteristics of Al/Ti/4H--SiC Schottky barrier diodes (SBDs) in the temperature range of 77 K--500 K, which shows that Al/Ti/4H--SiC SBDs have good  rectifying behaviour. An abnormal behaviour, in which the zero bias barrier height decreases while the ideality factor increases with decreasing temperature ($T$), has been successfully interpreted by using thermionic emission theory with Gaussian distribution of the barrier heights due to the inhomogeneous barrier height at the Al/Ti/4H--SiC interface. The effective Richardson constant $A^*=154$ A/cm$^{2}$ $\cdot$ K$^{2}$ is determined by means  of a modified Richardson plot $\ln(I_{0}/T^{2})-(q\sigma )^{2}/2(kT)^{2}$ versus $q/kT$, which is very close to the theoretical value 146~A/cm$^{2}$ $\cdot$ K$^{2}$.

Key words: Schottky contact, 4H—SiC, barrier height inhomogeneity, temperature

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

  • 73.30.+y
73.40.Sx (Metal-semiconductor-metal structures)