Photoinduced carrier lifetime measuring method, light incidence efficiency measuring method, photoinduced carrier lifetime measuring device, and light incidence efficiency measuring device

摘要

A photoinduced carrier lifetime measuring method capable of obtaining photoinduced carrier effective lifetime of a semiconductor substrate with high accuracy regardless of the surface state of the sample. The method includes: irradiating a microwave onto a semiconductor substrate while periodically pulse-irradiating a light onto the semiconductor substrate; detecting the microwave transmitted through the semiconductor substrate or reflected by the semiconductor substrate; and obtaining the effective lifetime of photoinduced carriers generated in the semiconductor substrate by the pulse irradiation of the light, based on an irradiation duration T1 and a non-irradiation duration T2 when performing the light pulse irradiation and an integrated value of each microwave intensity obtained by the detection.

主权项

1. A photoinduced carrier lifetime measuring method comprising:
irradiating, by a microwave source, a microwave onto a semiconductor substrate while periodically pulse-irradiating, by an irradiating light source, a light onto the semiconductor substrate; detecting, by a detector, the microwave transmitted through the semiconductor substrate or reflected by the semiconductor substrate; and obtaining, by calculating circuitry, the effective lifetime of photoinduced carriers generated in the semiconductor substrate by the pulse irradiation of the light, based on an irradiation duration T1 and a non-irradiation duration T2 when pulse-irradiating the light and an integrated value of each microwave intensity obtained by the detection; wherein the light pulse irradiation is performed plural times, each with a changed irradiation duration T1 and a changed non-irradiation duration T2, the measuring method further comprising: detecting, by the detector, the microwave for each of the plural times of pulse irradiation; and obtaining, by the calculating circuitry, the effective lifetime of the photoinduced carriers generated in the semiconductor substrate by the light, based on each irradiation duration T1 and non-irradiation duration T2 and an integrated value of each microwave intensity obtained by each detection; wherein the detection of the microwave is performed in the non-irradiation duration T2 separated from the irradiation duration T1; and wherein the effective lifetime of the photoinduced carriers generated in the semiconductor substrate by the light is obtained based on the relation between the irradiation duration T1 and non-irradiation duration T2 and the ratio of a photoinduced carrier density corresponding to the integrated value of the microwave intensity detected in the non-irradiation duration T2 to a photoinduced carrier density in a period that includes at least the irradiation duration T1.