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. 18, 1999
Filed:
Jun. 19, 1997
Masaru Wakabayashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A method of manufacturing a semiconductor device made up of a Bi-CMOS integrated circuit with the performance of MOS and bipolar elements enhanced. A semiconductor substrate surface is selectively oxidized to divide surface into a bipolar element forming area and a MOS element forming area. Next, the entire substrate surface is oxidized to form an oxide film 9, after which high-density ions are implanted into a collector leading area. Then, driving-in of the collector leading area is performed by performing heat treatment in an oxidizing atmosphere while forming an oxide film 9b on the collector leading area and another oxide film 9a on the MOS element forming area. Subsequently, the oxide film is etched all over the semiconductor substrate surface by the thickness of the oxide film 9a to expose the semiconductor substrate surface of the MOS element forming area. Lastly, the substrate surface is entirely oxidized to form a gate insulation film thinner than the oxide film 9.