Patent ID: 9279762
Filing Date: 2016-03-08
CPC Classification: G01N,H01L

Claim Text:
1. A semiconductor carrier lifetime measuring apparatus, comprising: a light irradiation unit which irradiates at least two types of light having mutually different wavelengths on a semiconductor to be measured; a measurement wave irradiation unit which irradiates a predetermined measurement wave onto the semiconductor to be measured; and a detection/calculation unit which detects a reflected wave of the measurement wave that has been reflected by the semiconductor to be measured or a transmitted wave of the measurement wave that has transmitted through the semiconductor to be measured, and which obtains a carrier lifetime in the semiconductor to be measured based on the detection results so as to minimize any error; wherein the detection/calculation unit comprises: a detection unit which detects a reflected wave of the measurement wave that has been reflected by the semiconductor to be measured or a transmitted wave of the measurement wave that has transmitted through the semiconductor to be measured; and a calculation unit which obtains a carrier lifetime in the semiconductor to be measured based on a first difference in a temporal relative change of the reflected wave or the transmitted wave detected by the detection unit as a result of the light irradiation unit irradiating the at least two types of light onto the semiconductor to be measured and the measurement wave irradiation unit irradiating the measurement wave onto the semiconductor to be measured when the semiconductor to be measured is in a first surface recombination velocity condition, and based on a second difference in a temporal relative change of the reflected wave or the transmitted wave detected by the detection unit as a result of the light irradiation unit irradiating the at least two types of light onto the semiconductor to be measured and the measurement wave irradiation unit irradiating the measurement wave onto the semiconductor to be measured when the semiconductor to be measured is in a second surface recombination velocity condition which is different from the first surface recombination velocity condition.