A Spreading Resistance Technique for Resistivity Measurements on Silicon

Abstract

Atechnique for determining local silicon resistivity from the measured spreadingresistance associated with a metal to semiconductor, small-area pressure contactis described. The major problems encountered in earlier attempts toderive quantitative resistivity data from small area pressure contacts onsilicon have been circumvented by making the measurements at biaslevels of a few millivolts and by using a particularosmium-tipped probe arrangement to provide contact reproducibility. The method providesa three-dimensional spatial resolution in resistivity measurements on silicon onthe order of 1µ, and, using a calibration curve determinedfor a particular silicon surface finish, yields an experimental reproducibility15% for sample resistivities in the range 10−3 ohm-cm 500 ohm-cm. Several examplesof the application of the technique to problems of currentinterest in silicon technology are given. ©1966 The Electrochemical Society, Inc.