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:
Dec. 15, 1998
Filed:
Nov. 25, 1996
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A part of a gate insulation film between a semiconductor substrate and an exposed gate electrode of a semiconductor device is partially and stepwise etched away. A voltage is applied between the semiconductor substrate and the gate electrode in a chemical wet etching system at each step. An anode oxide film is formed on the surface of the gate electrode in a step, when a defect is included in a gate oxide film. The gate electrode is etched away in another step, when a defect is not included in the gate oxide film. A position of a defect in the gate insulation film is detected from the difference in the area of the gate insulation film when an anode oxide film is formed on the gate electrode, and when the gate electrode is etched away.