Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To reduce the difference in level with oxide film thinning a polycrystalline layer without thinning a monocrystalline layer by a method wherein the monocrystalline semiconductor is formed to an active region and the polycrystalline semiconductors to an electrode portion, and the difference of speed of oxidation is utilized. CONSTITUTION:Oxide insulating films 2 are made up at both sides on a semiconductor substrate 1, holding a necessary part, and a n<+> type buried layer 4 is built up to the necessary part. Crystals are grown on the oxide films 2 and the buried layer 4 in epitaxial method, and a monocrystalline Si layer 5 is formed to a part where an active element such as a bipolar transistor is made up and polycrystalline Si layers 6 are built up to parts functioning as wiring on the oxide films 2. The whole is oxidized at a low temperature, the polycrystalline Si layers 6 are oxidized at speed treble as fast as the monocrystalline layer 5, and the surfaces of both layers 5a, 6c are made approximately same surfaces. An oxide film 15 is removed, and a bipolar transistor, etc. are formed to the monocrystalline Si layer 5a. Thus, the thickness of an external base layer 8b and a collector layer 11a of the polycrystalline Si layers 6c is thinned, and difference in level with the oxide films 2 can be reduced.

Inventors

• 👤 Masahiko Denda
• 👤 Hiromi Sakurai

Bibliographic Details