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:
Oct. 11, 1994
Filed:
Aug. 25, 1992
Peter W Lee, Fremont, CA (US);
David N Wang, Saratogo, CA (US);
Makoto Nagashima, Machida, JP;
Kazuto Fukuma, Osaka, JP;
Tetsuya Sato, Narita, JP;
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
A composite BPSG insulating and planarizing layer is formed over stepped surfaces of a semiconductor wafer by a novel two step process. The composite BPSG layer is characterized by the absence of discernible voids and a surface which is resistant to loss of boron in a subsequent etching step. The two step deposition process comprises a first step to form a void-free BPSG layer by a CVD deposition using gaseous sources of phosphorus and boron dopants and tetraethylorthosilicate (TEOS) as the source of silicon; and then a second step to form a capping layer of BPSG by a plasma-assisted CVD deposition process while again using gaseous sources of phosphorus and boron dopants, and TEOS as the source of silicon, to provide a BPSG cap layer having a surface which is non-hygroscopic and resistant to loss of boron by subsequent etching.