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. 13, 1993
Filed:
Dec. 27, 1991
Applicant:
Inventors:
Kiichi Hirano, Sendai, JP;
Nobuo Takeda, Sendai, JP;
Assignee:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437192 ; 437-7 ; 437-8 ; 437187 ; 437926 ;
Abstract
A tungsten film is formed in two steps in a tungsten chemical vapor deposition method of the present invention. In a first step, a first thin tungsten film is selectively grown on a surface of a silicon substrate by a silicon reduction using a WF.sub.6 gas as a tungsten source, followed by a second step in which another tungsten film is formed on the first tungsten film by a silane reduction using a WF.sub.6 gas as a tungsten source. The state of the silicon substrate surface is monitored by a pyrometer, and the timing of change from the silicon reduction to the silane reduction is determined on the basis of the intensity of the infrared ray radiation.