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:
Aug. 10, 1999
Filed:
Jun. 01, 1998
Hitoshi Abiko, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
To form a device isolating deep trench adjacent to a well, the deep trench is formed by using, as a mask, a photoresist mask used for forming the well and a silicon oxide film or a polysilicon film formed on a semiconductor substrate and patterned by an etching using another photoresist mask which was used for forming an adjacent well, or two patterned insulating layers formed on the semiconductor substrate. Thus, the deep trench for the device isolation can be formed without adding a photoresist step for forming a trench formation pattern. In addition, since a lift-off process is not used for forming the deep trench, an isolation trench having a narrow width can be formed, and also, there does not occur the re-deposition of the peeled-off plasma CVD insulating film onto the semiconductor substrate, with the result that the stability in manufacturing the semiconductor device is remarkably elevated.