| 摘要 |
PURPOSE:To reduce intrusion to an active region of a field oxide film, and to improve the degree of integration by forming an oxidation-resisting first mask layer on the surface of an epitaxial layer opposite to a high-concentration impurity region in double layer constitution of an oxide film and a nitride film formed on the oxide film in the manufacturing process of the bipolar type semiconductor device through a selective oxidation method. CONSTITUTION:An oxide film 14 formed to the surface layer section of the epitaxial layer 8 not coated with an oxidation-resisting first mask 10a through thermal oxidation is removed until the shoulder section 15 of the mesa-shaped layer 8 is exposed, and the thin oxide film 16 is left. The nitride film 17 in 50- 150Angstrom is formed on the shoulder section 15 as a second oxidation-resisting mask through thermal nitriding while using the film 16 as a mask. The thick field oxide film 11 deeply buried in the layer 8 is grown through oxidation in a wet oxygen atmosphere. Intrusion to the active region 12 of the film 11 is inhibited by the thermal nitride film 17 at that time. A nitride film 10, an oxide film 9 and the thermal nitride film 17 are removed, and the active region 12 and a field region 13 are formed. |
