Patent ID: 7420684
Filing Date: 2008-09-02
Classification: G01N

Abstract:
1. A measurement apparatus for measuring surface carrier recombination velocity, comprising: a light modulator; an excitation light source for irradiating a surface of a semiconductor sample with a pump beam via the light modulator; a probe light source for irradiating the surface of the semiconductor sample with a probe beam; an instrument for maintaining surface temperature of the semiconductor sample constant while irradiating the surface of the semiconductor sample with the probe beam and the pump beam; a first light detector for spectrally detecting probe beam light that is reflected from the surface of the semiconductor sample; a second light detector for detecting photoluminescence of the semiconductor sample and light scattered from the surface of the semiconductor sample while the semiconductor sample is irradiated by at least one of the probe beam and the pump beam; a differential amplifier for comparing a first signal corresponding to surface electric field strength of the semiconductor sample and produced by the first light detector and a second signal corresponding to photoluminescence of the semiconductor sample and scattered light scattered from the surface of the semiconductor sample and produced by the second light detector; and a calculator for calculating the surface electric field strength from the period of Franz-Kleldysh oscillations appearing in an output signal produced by the differential amplifier.