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.
下载:
