Measurement of Semiconductor Minority Current Carrier Lifetimes by Observing the Photoconductive Decay of Spreading Resistance under a Point Contact

摘要

A new method for measuring the lifetime 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 has the following advantages; (1) it is not necessary to cut the specimen to a special shape; (2) it is not necessary to make a fixed electrode for the specimen; (3) it is applicable for testing non-homogeneous specimens; (4) no particular surface treatment is necessary; (5) the apparatus used is simple and easy to operate; (6) the technique delivers sufficient accuracy. A theoretical analysis of the effects of surface recombination rate and varying absorption depth of light in the specimen is given. Experimental details and discussion are given for Ge and Si specimens. The results are in good agreement with those obtained by other methods. (Author)