METHOD OF EVALUATING IMPURITY IN SILICON EPITAXIAL WAFER

摘要

PROBLEM TO BE SOLVED: To provide a method of carrying out a qualitative and quantitative analysis of a heavy metal impurity included in a silicon epitaxial wafer in a highly sensitive manner. SOLUTION: The method of evaluating an impurity in a silicon epitaxial wafer has: a film forming process of vapor-phase growing a silicon single-crystal thin film on a silicon single-phase crystal substrate under a hydrogen atmosphere by supplying a source gas during the process; a cooling process of calculating a temperature at which a specified value or process average value for the concentration of a to-be-evaluated impurity present in the silicon single-phase crystal thin film matches the solid solution limit concentration of the to-be-evaluated impurity and cooling a silicon epitaxial wafer having the silicon single-crystal thin film formed thereon by the film forming process under temperatures at least ranging from 50°C below to 50°C above the calculated temperature at a 20°C/sec or greater cooling rate after silicon epitaxial wafer film-formation; and an evaluation process of chemically analyzing the surface layer of the silicon single-crystal thin film to evaluate the concentration of the to-be-evaluated impurity. COPYRIGHT: (C)2011,JPO&INPIT