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:
Oct. 14, 1997
Filed:
Apr. 10, 1996
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor device (100) including a silicon substrate (1), a gate oxide film (2) formed on the silicon substrate (1) and having a defect (3) and a dielectric breakdown voltage failure portion (4), and a polysilicon film (5) formed on the gate oxide film (2) is immersed in a chemical etchant (7) in a wet etching apparatus (9). With the silicon substrate (1) serving as an anode, a DC voltage source (6) of the wet etching apparatus (9) applies voltage to the silicon substrate (1) to perform anode oxidation. Passivation layers (10) are formed on parts of the surface of the polysilicon film (5) which overlies the defect (3) and dielectric breakdown voltage failure portion (4) but are not formed on the surface of the polysilicon film (5) in regions insulated by the gate oxide film (2). The polysilicon film (5) in the regions on which the passivation layers (10) are not formed is removed by the chemical etchant (7).