| 摘要 |
PURPOSE:To make it possible to manufacture a semiconductor device having a Schottky diode, whose leaking current is small, by providing a hole for a guard ring region for the Schottky diode at the same time when a collector contact hole is formed, diffusing impurities from the upper part of etched silicon, forming a guard ring layer, and exposing the surface of an epitaxial layer surrounded with said layer. CONSTITUTION:After a P-type polycrystalline silicon is removed, boron is implanted, and a P-type polycrystalline silicon layer 208B is formed. Then a nitride film 211 is formed. Boron is diffused in an epitaxial layer 103 by heat treatment. A guard ring 210 for a Schottky diode is formed around an oxide film. Then silicon on the nitride film and a Schottky-junction forming region is removed. An oxide film 105 on the Schottky-junction forming region is exposed. After a CVD silicon oxide film is grown, the oxide film 105 on a contact region and the Schottky-junction forming region is removed. The surface of the epitaxial layer surrounded with the guard ring 210 is exposed. Thereafter, a platinum silicide layer 126 is formed, and the Schottky junction is formed. |
