Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To form a third thermal oxide film in even thickness with a rugged corner rounded by a method wherein a first thermal oxide film is formed on the rugged surface of Si and after partially removing the oxide film by etching process, a second thermal oxide film is formed. CONSTITUTION:The first thermal oxide film 5 is formed on the rugged surface of Si 1 to be partly removed by etching process. At this time, the thermal oxide film at a corner A becomes extremely thin or the Si surface at the same part is exposed to atmosphere. Next, when another oxide film 6 is formed below the film 5 by the second thermal oxidation, the thermal oxidation at the corner A is accelerated making the angular part A round. After entirely removing the oxide films 5, 6, the third thermal oxide film can be formed on the surface of Si 1 to form the other oxide film in even thickness on the rugged surface of Si 1. When this oxide film is applied to the oxide film formed into a grooved type capacitor of a DRAM, the breakdown strength at the corner can be prevented from deteriorating, enabling a MOS capacitor with the least leakage current to be produced.

Inventors

• 👤 Kiyotarou Imai
• 👤 馨太郎 今井
• 👤 Kikuo Yamabe
• 👤 紀久夫 山部

Bibliographic Details