METHOD FOR DEPOSITING THIN METALLIC FILM

摘要

PURPOSE:To form flat thin metallic films having excellent adhesion on a substrate surface by executing formation of the thin metallic films and removal of the by-product of reaction sticking to the substrate surface repeatedly >=2 times at the time of depositing the thin metallic films on the substrate surface by a CVD method. CONSTITUTION:A gaseous mixture composed of gaseous WF6 and gaseous H2 is supplied to the surface of the substrate having an SiO2 film 2 in part of the surface of an Si wafer 1 and the substrate is heated to 200-600 deg.C to reduce WF6 in the Si- exposed part by Si and to form a metallic W film 3. The by-product of reaction 4 such as WFX (X=1-5) lower than WF6 is formed and adhered near to the boundary face of the W film 3 and the Si wafer 1 and WOXFY, etc., are formed and adhered by reaction with SiO2 onto the surface of the SiO2 film 2. The supply of the reactive gas is then stopped and after the gas is evacuated to a vacuum state, the substrate is heated to 300-600 deg.C to evaporate the by-product of reaction 4 such as WFX and WOXFY. The above-mentioned two stages, i.e., formation of the W film and the evaporation and removal of the by-product of reaction 4 are repeated in succession. The extremely flat W film having the excellent adhesiveness is thereby formed without allowing the by-product of reaction to remain in the Si-exposed part.