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:
May. 07, 2002
Filed:
Feb. 22, 2001
Applicant:
Inventors:
Takashi Terauchi, Tokyo, JP;
Hiroki Shinkawata, Tokyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/18238 ;
U.S. Cl.
CPC ...
H01L 2/18238 ;
Abstract
An oxide film is formed on a silicon substrate . The oxide film is topped with wiring patterns 34. Top and side portions of the wiring patterns are covered with nitride film top walls and nitride film side walls . After an interlayer oxide film is deposited, contact holes are formed through self-alignment. Under the nitride film side walls , isotropic etching is carried out to retract side edge surfaces of the oxide film from the wall surface. Contacts are then formed inside the contact holes whose bottom diameter is expanded by the isotropic etching above.