Forming process of element isolation region

Abstract

Abstract PURPOSE:To improve the element characteristics easily forming a field oxide film with specified film thickness by a method wherein an acid resistant mask film and a step difference forming film as well as the peripheral region of a selective oxide film are removed leaving a flat film on the selective oxide film. CONSTITUTION:A selective oxide film 25 is formed on a semiconductor substrate 20 by means of selective oxidation through the intermediary of a wondow 24. Firstly a flat films 26 is formed blocking the window 24 on a step difference film 23. Then the surface region of the flat film 26 is removed by etching back process. Secondly the step difference forming film 23 is removed by etching process utilizing another flat film 26a as a mask. Likewise after removing an acid resistant mask 22, the peripheral region of the selective oxide film 25 including a foundation film 21 is removed to form a field oxide film 27. Through these procedures, the field oxide film 27 which sufficient thickness may be easily formed even into fine pattern.

Inventors

• 👤 Yuji Fukazawa
• 👤 深沢　雄二

Bibliographic Details