Semiconductor doping characterization method using photoneutralization time constant of corona surface charge

Abstract

Methods of characterizing semiconductor doping in a wide bandgap semiconductor sample include: measuring an initial value, V0, of a surface voltage at a region of a surface of the semiconductor sample in the dark; charging the region to deep depletion in the dark by depositing a prescribed corona charge at the region; measuring the surface voltage value in the dark at the region after charging; illuminating the charged region with light of a specific photon flux, feff, having a photon energy above the semiconductor bandgap sufficient to generate free minority carriers in the semiconductor sample causing photoneutralization of the corona charge; monitoring of a photoneutralization induced corona charge decay at the region vs. illumination time, t, using a noncontact time resolved measurement of surface voltage, V(t); analyzing the monitored time resolved surface voltage decay data V(t) to determine values for a parameter characteristic of a photoneutralization induced corona charge decay at the regions; and using the parameter at a specific photon flux, ϕeff, to characterize the property of the semiconductor at the region based on the values of the parameter.

Dependencies are inferred from the claim text.