황처리가 금속/InP Schootky 접촉과 $Si_3$$N_4$/InP 계면들에 미치는 영향

Effects of sulfur treatments on metal/InP schottky contact and $Si_3$$N_4$/InP interfaces

  • 허준 (아주대학교 전자공학과) ;
  • 임한조 (아주대학교 전자공학과) ;
  • 김충환 (전자통신연구소 화합물개발실) ;
  • 한일기 (한국과학기술원 정보전자 연구부 광전자연구실) ;
  • 이정일 (한국과학기술원 정보전자 연구부 광전자연구실) ;
  • 강광남 (한국과학기술원 정보전자 연구부 광전자연구실)
  • Her, J. (Dept. of Elec. Eng., Ajou Univ.) ;
  • Lim, H. (Dept. of Elec. Eng., Ajou Univ.) ;
  • Kim, C.H. (Dept. of Compound Semiconductor ETRI) ;
  • Han, I.K. (KIST, Division of Elec. & Inform., Optoelectron. Lab) ;
  • Lee, J.I. (KIST, Division of Elec. & Inform., Optoelectron. Lab) ;
  • Kang, K.N. (KIST, Division of Elec. & Inform., Optoelectron. Lab)
  • 발행 : 1994.12.01

초록

The effects of sulfur treatments on the barrier heithts of Schottky contacts and the interface-state density of metal-insulator-semiconductor (MIS) capacitors on InP have been investigated. Schottky contacts were formed by the evaporation of Al, Au, and Pt on n-InP substrate before and after (NH$_{4}$)$_{2}$S$_{x}$ treatments, respectively. The barrier height of InP Schottky contacts was measured by their current-voltage (I-V) and capacitance-voltage (C_V) characteristics. We observed that the barrier heights of Schottky contacks on bare InP were 0.35~0.45 eV nearly independent of the metal work function, which is known to be due to the surface Fermi level pinning. In the case of sulfur-treated Au/InP ar Pt/InP Schottky diodes, However, the barrier heights were not only increased above 0.7 eV but also highly dependent on the metal work function. We have also investigated effects of (NH$_{4}$)$_{2}$S$_{x}$ treatments on the distribution of interface states in Si$_{3}$N$_{4}$InP MIS diodes where Si$_{3}$N$_{4}$ was provided by plasma enhanced chemical vapor deposition (PECVD). The typical value of interface-state density extracted feom 1 MHz C-V curve of sulfur-treated SiN$_{x}$/InP MIS diodes was found to be the order of 5${\times}10^{10}cm^{2}eV^{1}$. This value is much lower than that of MiS diodes made on bare InP surface. It is certain, therefore, that the (NH$_{4}$)$_{2}$S$_{x}$ treatment is a very powerful tool to enhance the barrier heights of Au/n-InP and Pt/n-InP Schottky contacts and to reduce the density of interface states in SiN$_{x}$/InP MIS diode.

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