Investigation of the undersurface damaged layers in silicon wafers

Abstract

The undersurface damaged layers of the silicon wafers were studied by electroreflectance method. These damaged layers could be created at cutting or standard treatment (ST) of the silicon wafers. The silicon substrates were layer by layer etched in the polishing etching solution for investigation of the undersurface damaged layers. Surface and undersurface layers were qualified by the phenomenological parameter of broadening (PPB) from the electroreflectance spectra. The concealed undersurface damaged layers with thickness 25 µm were observed on the ST samples. The PPB decreased with exponential rule for the samples after cutting and achieved the permanent value on the depth 125 µm.