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:
Jul. 23, 1996
Filed:
Oct. 07, 1994
Masao Kunitou, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A fabrication method of a semiconductor integrated circuit device is provided. A patterned oxidation-resistant film such as silicon nitride film is formed on or over a semiconductor substrate. Using the patterned oxidation-resistant film as a mask, the substrate is then thermally oxidized so that a first oxide film for isolation is selectively formed to define active regions on the substrate. After the oxidation-resistant film is removed, the substrate is thermally oxidized so that a second oxide film is formed on the active regions, without adding any process step. Then, the substrate is etched until the second oxide film is entirely removed so that the surfaces of the active regions are exposed. During this process step, the first oxide film is partially removed. Subsequently, a patterned conductor film is formed on the first oxide film and then, it is removed from the first oxide. Even if steps or protrusions produced on the first oxide film due to the 'bird's head phenomenon', the steps or protrusions can be reduced in size or removed entirely together with the partial removal of the first oxide film. No leavings of the conductor film is produced on the first oxide film, avoiding short-circuit of the patterned conductor film.