The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 2000
Filed:
Apr. 27, 1998
Yasushi Matsuda, Kodaira, JP;
Hideo Miura, Koshigaya, JP;
Hirohiko Yamamoto, Hachioji, JP;
Masamichi Kobayashi, Kodaira, JP;
Shuji Ikeda, Koganei, JP;
Akira Takamatsu, Hamura, JP;
Norio Suzuki, Mito, JP;
Hirofumi Shimizu, Nakakoma-gun, JP;
Yasuko Yoshida, Sayama, JP;
Kazushi Fukuda, Ome, JP;
Shinichi Horibe, Akiruno, JP;
Toshio Nozoe, Higashiyamato, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi ULSI Systems Co., Ltd., Tokyo, JP;
Abstract
A silicon oxide film 2 which is exposed from a side wall of a groove 4a is etched to displace the silicon oxide film 2 backward toward an active region. The displacement amount is set to be equal to or more than a film thickness (Tr) of a silicon oxide film 5 to be formed on an inner wall of the groove 4a in a later thermal oxidation step and equal to or less than twice the film thickness (Tr) thereof. A shoulder portion of the groove 4a can be rounded by a low-temperature heat treatment at 1000.degree. C. or less, by controlling a heat treatment period such that the film thickness (Tr) of the silicon oxide film 5 is more than the film thickness (Tp) of the silicon oxide film 2 and equal to or less than three times the film thickness (Tr) thereof (Tp<Tr.ltoreq.3Tp)