PURPOSE: To enable the resistivity of a growth layer to be measured even if it is 1μm or below in thickness by a method wherein a variable bias voltage is applied between a conductive layer and the back of a silicon epitaxial wafer, the chopped light is made to impinge on the growth layer, and a surface photovoltage induced on the surface of the growth layer is measured.

CONSTITUTION: A junction wafer directly joined to a silicon single crystal mirror surface wafer grown in a CZ method is polished through a normal mirror surface technique so as to evaluate the effectiveness of a resistivity evaluation technique of a semiconductor thin layer through a Schottky CV method and a four-point method. A silicon single crystal thin film layer is controlled to be as thick as 1μm or so, and a resistivity evaluation technique is applied to a part of the film layer whose thickness is smaller or larger than 1μm. A resistivity previously obtained through a four-point method on a silicon wafer mirror surface side is used as a true value. A voltage applying insulator organic film is formed through such a method that tin is vapor-deposited on one side of a polyester film 50μm in thickness. Light rays 560nm in wavelength are used for measurement.