| 摘要 |
PURPOSE:To prevent defects in laminated layers yielded in a poly Si oxidation process and to improve reliability of a semiconductor device, by exposing Si only in a region (walled emitter region) where poly Si is made to remain in the future before poly Si is deposited, and forming an oxide film on the other Si surface. CONSTITUTION:An N type epitaxial layer 3 is grown through an N<+> type embedded layer 2 on a P type Si substrate 1. An isolation oxide film 4 is formed down to the depth reaching the N<+> embedded layer 2. Photoetching is performed on the surface of a region I of the epitaxial layer surrounded by the oxide film layer 4. An N<+> diffused layer 5 is formed so as to reach the embedded layer 2. The poly Si film on the region I , wherein an Si3N4 film mask is not formed, is oxidized, and a poly Si oxide film 9 is formed. The side of the region I is covered by a mask. A P-base layer 10 is formed in the epitaxial layer in a region II through the poly Si film by boron ion implantation. Impurities for a Schottky barrier diode are introduced in the side of a surrounding region. Ion implantation is performed for forming an N<+> emitter 11 on the surface of the base layer in the region II. Hot etching is performed on the side of the region I . |
