Patent ID: 8064054
Filing Date: 2011-11-22
Classification: F21Y,G01N,H01L,Y02E

Abstract:
1. A method of inspecting an indirect bandgap semiconductor structure, said method comprising the steps of: generating light suitable for inducing photoluminescence in said indirect bandgap semiconductor structure; short-pass filtering said light to reduce long-wavelength light of said generated light above a specified emission peak; collimating said light; substantially uniformly and simultaneously illuminating a large area of said indirect bandgap semiconductor structure with said collimated, short-pass filtered light; capturing images of photoluminescence simultaneously induced by said substantially uniform, simultaneous illumination incident across said large area of said indirect bandgap semiconductor structure using an image capture device capable of capturing simultaneously said induced photoluminescence; and image processing said photoluminescence images to quantify spatially resolved, specified electronic properties of said indirect bandgap semiconductor structure using the spatial variation of said photoluminescence induced in said large area; wherein said short-pass filtering step reduces by a factor of about 10 or more the total photon flux in a long-wavelength tail of said generated light, said long-wavelength tail beginning at a wavelength that is about ten percent (10%) higher than a longest wavelength emission peak of a source for generating said light.