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:
Jun. 22, 1999
Filed:
Sep. 26, 1997
Applicant:
Inventor:
Tah-Te Shih, Taipei, TW;
Assignee:
Vanguard International Semiconductor Corporation, Hsin-Chu, TW;
Primary Examiner:
Int. Cl.
CPC ...
G03F / ;
U.S. Cl.
CPC ...
430-5 ;
Abstract
A transmission modulation mask comprising a first pattern formed of opaque or non light transmitting material and a second pattern formed of partially transmitting material. The light passing through the transmission modulation mask forms interference patterns which improve the edge definition and depth of focus of the image formed on a semiconductor wafer. The transmission modulation mask is particularly useful for small contact hole formation requiring a high degree of dimensional control such as the formation of stacked capacitors for DRAM circuits.