Abstract: A method for a flatter semiconductor wafer free of ORP-observed irregularity and particles generated in handling on the back side of the wafer, in which an alkaline etching is adopted to utilize its advantage and a slight polishing step is combined to a conventional method of this kind. A deficiency of alkaline etching which brings about rougher surface irregularities on the surface of a wafer is eliminated by the use of the step of slight polishing on the back surface after the etching step and the inherent advantage stands without a loss, so that particle generation from the back surface of a semiconductor wafer in handling is much reduced and what's more a flatter semiconductor wafer is realized and a yield of an electronic device fabrication is increased.

Abstract: A wafer which allows manufacture of a device to proceed at an exalted yield by preventing the resolution of exposure at the step of photolithography during the manufacture of the device from being impaired is obtained by a method which comprises a slicing step for slicing a single crystal ingot thereby obtaining wafers of the shape of a thin disc, a chamfering step for chamfering the wafer obtained by the slicing step, a lapping step for imparting a flat surface to the chamfered wafer, an etching step for removing mechanical strain remaining in the lapped wafer, an obverse surface-polishing step for polishing one side of the etched wafer, and a cleaning step for cleaning the polished wafer, which method is characterized by interposing between the etching step and the obverse surface-polishing step a reverse surface-preparing step for preparing the shape of the reverse side of the wafer.