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. 30, 1999
Filed:
Apr. 28, 1995
Applicant:
Inventors:
Gregory Joseph Stagaman, Dallas, TX (US);
Michael Edward Haslam, Highland Village, TX (US);
Assignee:
STMicroelectronics, Inc., Carrollton, TX (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
438720 ; 438718 ; 438722 ; 438723 ;
Abstract
A method is provided for reducing the reflectivity of a metal layer prior to photolithography. A thin buffer layer, such as oxide, can be deposited over the metal layer. A short plasma etch is performed in order to roughen, but not completely remove, the thin oxide layer. This roughened layer significantly reduces the reflectivity of the underlying metal layer. As an alternative, the brief plasma etch can be applied directly to the metal layer, which results in a significant roughening of its upper surface. This also reduces the reflectivity of the metal layer.