Manufacture of mos transistor

Abstract

Abstract PURPOSE: To stabilize threshold voltage by heat-treating gate insulating film consisting of SiO 2 film and Si 3 N 4 film according to decompression vapor phase growth process in a foaming gas. CONSTITUTION: An SiO 2 film 2 for field is formed on p-type Si substrate, an Si 3 N 4 film 4 is placed on an SiO 2 film for gate according to decompression vapor phase growth process, which is covered with a metallic film 5 to a desired gate pattern. Then an n + -layer 7 is formed by ion injection, an SiO 2 film 8 is subjected to a vapor phase growth and heat-treated at about 1,000°C for activation of the injected atom and also for compacting the film 8. After that, a surface charge of the SiO 2 film and the Si 3 N 4 film is decreased through treating at about 700∼1,000°C in a foaming gas for several hours. Next, a hole is perforated in the films 8 and 3 to provide a wiring metal 9. According to this constitution, an unstableness in electrical characteristic of the Si 3 N 4 film grown through decompression is dessolved and a threshold voltage is satisfactorily stabilized. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Atsumasa Doi

Bibliographic Details