Patent ID: 9171737
Filing Date: 2015-10-27
Classification: H01L

Abstract:
1. A method of forming a thermal oxide film on a silicon single crystal wafer, comprising: placing the silicon single crystal wafer into a heat treatment furnace at a starting temperature; elevating a temperature of the heat treatment furnace from the starting temperature up to a temperature T1 where a thermal oxide film is formed to form a thermal oxide film having a thickness d1 of 500 nm or more; subsequently lowering the temperature of the heat treatment furnace down to a temperature equal to or less than the starting temperature and lower than the temperature T1 by 200° C. or more; and thereafter elevating the temperature of the heat treatment furnace up to a temperature T2 higher than the temperature T1 without having taken the silicon single crystal wafer out of the heat treatment furnace to additionally form a thermal oxide film having a thickness d2 thicker than the thickness d1.