Patent ID: 7119569

Claim:
A method of measuring damage of an ion implanted semiconductor wafer during semiconductor processing, said method comprising the steps of: a) conveying said wafer such that a surface of said wafer is substantially parallel to a surface photovoltage electrode of a head assembly during said semiconductor processing; b) exposing at least a portion of said wafer to light having a wavelength and having an maximum intensity, said maximum intensity being insufficient to affect charge distribution in said wafer; c) modulating, at a frequency, the intensity of the light up to the maximum intensity; d) detecting with said surface photovoltage electrode a photovoltage induced at the surface of said wafer in response to said modulated light intensity; e) calculating an electrical property of said wafer from said photovoltage induced at the surface of said wafer; and f) repeating steps b–e for a plurality of light intensity modulation frequencies.