METHOD FOR MAKING SOI FILM THICKNESS UNIFORM IN SOI SUBSTRATE

摘要

PURPOSE:To provide a method of uniforming the thickness of SOI on an SOI substrate by suppressing the dispersion of the SOI film thickness to less than + or -0.3mum throughout the whole surface of a substrate even for an SOI substrate having the SOI film thickness of more than 1mum but less than 10mum. CONSTITUTION:Surface of an SOI substrate 11 is divided into a plurality of subdivisions, the SOI film thickness is measured for each subdivision Wi (i=1 to n) on the SOI substrate by a spectral interference method using an optical fiber 30 and, at the same time, the SOI film is subjected to the etching treatment by a dry etching equipment 40 until the SOI film becomes a predetermined thickness thereby reducing the SOI film thickness and its dispersion (+ or -0.3mum) to less than the desired values.