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. 07, 1998
Filed:
Oct. 28, 1996
Chwan Chao Chen, Hsinchu, TW;
Chia Chen Liu, Hsinchu, TW;
Holtek Microelectronics, Inc., Hsinchu, TW;
Abstract
A method of fabricating alignment marks on an integrated circuit device including steps of: forming first pad oxide layer and first nitride layer on a P-type semiconductor substrate; coating and patterning first photoresist layer by lithography; partially etching first nitride layer to form first nitride pattern by first photoresist etching mask; and ion implanting N-type ions to form an N-doped region; coating and patterning second photoresist layer by lithography; partially etching first nitride pattern to form second nitride pattern; and ion implanting P-type ions to formed a P-doped region. Next, performing thermally drive in N-type and P-type impurities to form N-well and P-well regions, and growing an oxide layer simultaneously. Finally, the height difference between the oxide layer and the second nitride pattern producing a ladder topography can be used as an alignment mark for the succeeding lithographic processes.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile