Noncontact technique for the local measurement of semiconductor resistivity

A method is described for finding the local resistivity of a semiconductor crystal by measuring the radio frequency spreading resistance of a small probe placed on a flat surface of the sample. The method is nondestructive and does not require the attachment of electrical contacts. The resistivity measured is that of the material lying within a hemisphere of about 1 mm radius; measurements have been made over the range 0.1-100 Ω cm with good accuracy above 0.5 Ω cm. © 1965 The American Institute of Physics.