Methods of inspecting wafers for manufacturing light emitting elements

摘要

An irradiation light containing a light which wave length is not absorbed by the n-type clad layer, but is absorbed by the p-type active layer, is applied on the wafer for manufacturing light emitting elements with a double-hetero structure of a p-type clad layer, a p-type active layer and an n-type clad layer formed one after another on a semiconductor substrate. Defects are found by detecting the increased photoluminescent light due to generation of a conductivity-type inverted layer such as the n-type inverted layer. When the double-hetero structure is composed of a GaAlAs mixed crystal compound semiconductor, the irradiation light which contains a wavelength range of 600-650 nm is applied. When the defective area is an active layer deficient area, detection is conducted by using the reflection light from the surface of the semiconductor substrate.