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. 07, 1995
Filed:
Oct. 28, 1993
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In a method for producing a field effect transistor, a positive photoresist is deposited on a surface of a semiconductor substrate, the positive photoresist is exposed to light having an asymmetric intensity profile where a gate electrode is to be formed, the positive photoresist is converted into a negative photoresist, the negative photoresist is developed to form a pattern having an aperture opposite the gate electrode formation region of the substrate and asymmetric overhanging portions at the aperture, the semiconductor substrate is wet etched using the photoresist pattern as a mask to form a recess in the semiconductor substrate, and a gate metal is deposited using the photoresist pattern as a mask to form a gate electrode in the recess. Therefore, only one exposure process provides a photoresist pattern having asymmetric overhanging portions at the aperture of the pattern.