Patent ID: 6265890
Filing Date: 2001-07-24
Classification: G01R

Abstract:
A method for in-line, non-contact depletion capacitance measurement of a test semiconductor wafer, the method comprising:oxidizing a control wafer, and oxidizing a test wafer having a junction depletion region;measuring a control wafer surface voltage potential and a test wafer surface voltage potential with a non-contact electrostatic measurement means;directing a pulsed light source against the control wafer and the test wafer;measuring a control wafer surface photovoltage and a test wafer surface photovoltage with a non-contact SPV measurement means; and determining a depletion capacitance of the test wafer on the basis of the difference between the control wafer surface photovoltage and the control wafer surface voltage and the test wafer photovoltage and the test wafer surface voltage, and known dopant concentrations at the n-type and p-type regions of the test wafer.