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:
Mar. 12, 1991
Filed:
Aug. 16, 1989
Yong H Yoon, Seoul, KR;
Hyundai Electronics Industries Co., Ltd., Kyungki, KR;
Abstract
A doping method using an oxide film and a nitride film on a trench wall as a protective film to prevent the impurity from diffusing into the silicon wafer adjacent to the outer wall and to enable the formation of a substantially flat interface between the first and the second trench to provide a smooth step difference between the first trench and the second trench is disclosed. A highly integrated semiconductor device having a trench comprising a first trench having a bottom and with a second trench formed in the bottom of the first trench with an interface between the first trench and the second trench characterized by the interface between the first and the second trench being substantially flat to provide a smooth step difference between the first trench and the second trench is also disclosed.