Ag/InP Schottky结热退化机理的研究

Ag/InP Schottky结是制作TE场助光电阴极的关键,本文利用Auger分析技术,详细地研究了热处理对Ag/InPSchottky结界面特性的影响。实验结果表明高温长时间热处理会导致严重界面相互扩散,同时使Schottky结的势垒高度降低,理想因子增大,泡利负电性理论很好地解释了扩散效应。势垒高度的降低及理想因子的增大也是由界面互扩散造成的,这种扩散导致界面特性由Schotthy特性向欧姆性质转化。为防止界面互扩散及Schottky结特性的退化,可选用负电性小的金属制作Schottky结,并在工艺上尽量减少热处理的温度和时间。

RESEARCH ON THE THERMAL DEGRADATION MECHANISM OF Ag/InP SCHOTTKY JUNCTION

The properties of Ag/InP Schottky junction determine the characteristics of TE field-assisted photocathode. The effects of heat-treatment on Ag/InP Schottky were studied by Auger analysis technology and IV measurement. The experirnental resu*shOw thatO)In and P elements are found at Ag film surface and Ag element is diffused into InP substrate after high temperature and long time heat treatment. The atom inter-diffusion at Ag/InP interface can be explained by Pauli’s negativity theory ;(2)Shottky barrier is lowered and ideality factor is enlarged. This effect is also caused by inter-diffusion at interface which makes Schottky rectifying characteristics changes towards Ohm’s contact.To protect inte r-diffusion at Ag/InP interface and thermal deeradation of Schottky junction metals which have small values of negativity should be selected and high temperature、long time heat treatment should be avolued.