Selective oxidization and isolation

Abstract

Abstract PURPOSE:To reduce the warpage of a wafer due to stress by removing a nitride film deposited on the back of the wafer and selectively oxidizing the nitride film. CONSTITUTION:Oxide films 2 are formed onto an Si substrate 1 through a thermal oxidation method, and a nitride film 3 for a selective oxidation mask is shaped through a chemical vapor growth method. The surface of a wafer is coated with a resist 4, and the resist 4 is baked. The nitride film on the back of the wafer is removed through a plasma etching method Using a gas such as a CF4 group gas, and the resist 4 is gotten rid of by a sulfuric acid group peeling liquid. The surface of the wafer is coated with a resist 5, the resist 5 is patterned so as to mask the upper section of an active region through a photolithographic process, the nitride film 3 is etched, employing the resist 5 as a mask through the plasma etching method or a reactive ion etching method, and the resist 5 is taken away by the sulfuric acid group peeling liquid. An oxide film for isolation is grown on an isolation region not masked with the nitride film 3 through thermal oxidation in a steam atmosphere.

Inventors

• 👤 Noboru Kudo
• 👤 昇 工藤

Bibliographic Details