用触针下分布电阻的光电导衰退来测量半导体中少数载流子的寿命

本文提出了一种新的测量半导体材料中少数载流子寿命的方法。这方法是测量触针下分布电阻的光电导衰退。这方法具有下列优点:(1)样品不需要切成一定形状;(2)在样品上不需要做固定电极;(3)可以检验不均匀的材料;(4)不需要一定的表面处理;(5)仪器简单,操作方便;(6)有一定的准确度。文中对表面复合速度以及光线在样品中的吸收深度的影响进行了理论分析;同时对Ge和Si样品的实验数据进行了讨论。用这方法测得的寿命基本上与其他方法的结果符合。 关键词：

THE MEASUREMENT OF THE LIFE TIME OF MINORITY CURRENT CARRIERS IN SEMICONDUCTORS BY OBSERVING THE PHOTO-CONDUCTIVE DECAY OF THE SPREADING RESISTANCE UNDER A POINT CONTACT

A new method for measuring the life time of minority current carriers in semiconductors is described. Measurements are made by observing the photoconductive decay of the spreading resistance under a point contact. This method possesses the following advantages: (1) It is not necessary to cut the specimen into special form. (2) No fixed electrode has to be made to the specimen. (3) It is applicable to test inhomo-geneous specimen. (4) No particular surface treatment is necessary. (5) Apparatus used is simple and easy to operate. (6) Enough accuracy is obtainable. A theoretical analysis is given of the effects of surface recombination velocity and of varying absorption depth of the light in specimen. Experimental details and discussions are given for Ge and Si specimens. Results are in agreement with those obtained by other methods.