METHOD FOR FORMING SACRIFICIAL OXIDE LAYER USING WET OXIDATION

摘要

PURPOSE: A method for forming a sacrificial oxide layer using a wet oxidation is provided to prevent yield from being decreased by preventing a wafer from being damaged and contaminated and by making a threshold voltage not drop. CONSTITUTION: The wafer inserted into a tube is loaded into a reaction furnace maintained at a temperature of 650 deg.C. Oxygen gas is injected into the reaction furnace in an atmosphere of 650 deg.C, in an atmosphere in which the temperature is increased to 800 deg.C and in an atmosphere of a stable temperature of 800 deg.C. Hydrogen gas and oxygen gas are further injected into the reaction furnace in the atmosphere of 800 deg.C and the wafer is wet-oxidized. Nitrogen gas is injected to the reaction furnace in the atmosphere of the stable temperature of 800 deg.C, in an atmosphere in which the temperature is slowly decreased to 650 deg.C and in an atmosphere of a stable temperature of 650 deg.C and a purification process is performed. The wafer is unloaded at a temperature of 650 deg.C and is cooled.