PURPOSE: To prevent a semiconductor wafer from being contaminated by impurities existing in a manufacturing apparatus by a simple method.
CONSTITUTION: Silicon oxide films 21 are formed on the surfaces of a boat 19 and an inner silica tube 11 contaminated by a high-melting-point metal (tungsten). And silicon wafers 18e which neither have any tungsten silicide film nor have been contaminated are mounted on the boat 19 and heat-treated (800°C) in a vacuum. The measurement of the degree of contamination on the surfaces of the silicon wafers 18e has proved that it is lower than the detection limit (1E8atom/cm2) of a measuring apparatus. Namely. it becomes possible to suppress the scattering of the tungsten contaminating the surfaces of the boat 19 and the inner silica tube 11 by the silicon oxide films 21 covering the surfaces. As the result, it becomes possible to prevent the surfaces of the silicon wafers 18e from being recontaminated.
WATANABE HIROYUKI
HIRASE MASAKI
SAIDA ATSUSHI
AKIZUKI MAKOTO
AOE HIROYUKI
