Patent ID: 8338277

Claim:
A method for manufacturing an SOI substrate comprising at least: an oxygen ion implantation step of ion-implanting oxygen ions from one main surface of a single-crystal silicon substrate to form an oxygen ion implanted layer; and a heat treatment step of performing a heat treatment with respect to the single-crystal silicon substrate having the oxygen ion implanted layer formed therein to change the oxygen ion implanted layer into a buried oxide film layer, wherein acceleration energy for the oxygen ion implantation is previously determined from a thickness of the buried oxide film layer to be obtained, the thickness being 80 nm or below; the oxygen ion implantation step is carried out with the determined acceleration energy to manufacture the SOI substrate; the oxygen ion implantation step is carried out with the acceleration energy with which a thickness t BOX of the buried oxide film layer to be obtained and a standard deviation ΔRp of an in-depth concentration distribution of oxygen ion-implanted into the single-crystal silicon substrate can satisfy a formula ΔRp≦t BOX ; a dose amount of the oxygen ion implantation is 3.5×10 17 atoms/cm 2 or below; and the acceleration energy is 110 keV or below.