摘要
硫钝化对GaAsFET的电特性有重要影响[1].本文分析了硫钝化后GaAsMESFET饱和源漏电流(IDss)下降的原因,认为硫处理降低了和/(为施主缺陷密度;为受主缺陷密度),表面费米能级向价带顶移动,能带弯曲加剧,表面耗尽层变厚,导电沟道变窄,是导致饱和源漏电流下降的主要因素.对样品进行225℃退火可使饱和源漏电流恢复到钝化前的水平.
Sulfur passivation has considerable effect on the electrical properties of GaAs FET. In this paper, we investigated the mechanism for the decrease of saturated drain-source current ( ) due to sulfur passivation. It is likely that the sulfur passivation process reduces and the ratio of , where is the concentration of donor-type defects and is the concentration of acceptor-type defects .As a result, the Fermi level at the surface will shift towards the valence band maximum(VBM).Accordingly the band bending increases, and the surface depletion layer thickness enhances, therefore, the channel thickness reduces.This is the main factor resulting in the decrease of saturated drain-source current.The saturated drain-source current of the sulfur-passivated sample can resume to the value before passivation by the annealing at 225℃.
出处
《河北工业大学学报》
CAS
2004年第3期42-44,共3页
Journal of Hebei University of Technology
基金
国家重点实验室基金资助项目(51432020101JW0701)
关键词
硫钝化
场效应晶体管
饱和源漏电流
施主缺陷
受主缺陷
sulfur passivation
FET
saturated drain-source current
donor-type defect
acceptor-type defect
