Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To perform high reliability for a long period and to improve the withstanding voltage between a drain and a semiconductor substrate by implanting an impurity to the substrate through a hole formed by isotropic etching and a window formed by anisotropic etching, and then heat treating it. CONSTITUTION:A hole 26 for exposing an oxidation resistant film 22 is opened at an insulating film 23 by anisotropic etching. An etching for exposing the prescribed region 27 of an oxide film 21 is executed at the film 22 by a isotropic etching. An impurity 28 of the same conductive type as a semiconductor substrate 20 is implanted through the holes 26, 27. After the film 23 is removd, a local oxidation for forming a field oxide film 29 is achieved at the region exposed by the hole 27, and the film 22 is removed. Thus, channel stoppers 31 may be formed at the regions separated from a source, a drain and a gate regions. Further, an abrupt ipurity density slope of a P-N junction between the drain and the substrate 20 having the stoppers 31 can be alleviated.

Inventors

• 👤 Naoki Matsuo
• 👤 直樹 松尾
• 👤 Takao Aoki
• 👤 青木　隆生
• 👤 Kazuo Sato
• 👤 和雄 佐藤

Bibliographic Details