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:
Jan. 03, 1995
Filed:
Apr. 08, 1994
Applicant:
Inventor:
Heng S Huang, Taipei, TW;
Assignee:
United Microelectronics Corporation, Hsinchu, TW;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 52 ; 437 45 ; 437 48 ;
Abstract
This inventions provides a method to form metal lines with smaller line pitches than is possible using the conventional photolithographic single coating process. This invention provides for a double photolithographic process where the surface is coated, exposed and developed twice to form two sets of resist patterns. These resist patterns are used to form metal lines over all the buried bit lines. These metal lines provide better masking of the bit lines from the code implants thereby reducing bit line resistance and increasing ROM read speed.