| 摘要 |
PURPOSE:To reduce the cost by adding hydrogen chloride gas to material gas and selectively growing a silicon nitride film only on a silicon substrate. CONSTITUTION:A field oxide film 1 is formed on a silicon substrate 2. Polycrystalline silicon film 3 is formed and an electrode is formed. Then, a polycrystalline silicon film 5 is formed. For the selective growing of the silicon nitride film 4, the condition of helium diluted silane/ammonium/hydrogen chloride = 60/1200/5sccm is used. The pressure is 0.18Torr and the temperature is 800 deg.C. The silane gas is diluted to be 1:4 by helium and the quantity of the pure silane is 12 ccm. The volume ratio of the silane to hydrogen chloride is preferably 1:0.3-0.6. The decomposition of the silane is promoted, the partial pressure of silylene is increased and the selective growing of the silicon nitride film is allowed. Thus, a photolithograph process and a dry etching process are eliminated and the cost is remarkably reduced. |
