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. 14, 2000
Filed:
Nov. 21, 1997
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A first polysilicon film which contains phosphorus as an impurity is formed on a semiconductor substrate. A second polysilicon film which is higher in phosphorus concentration than the first polysilicon film is formed on the first polysilicon film. The second polysilicon film is anisotropically etched to expose a surface of the first polysilicon film. Thermal oxidation is then performed. A surface of the first polysilicon film and a surface of the second polysilicon film are oxidized according to their respective oxidization rates depending on their respective phosphorus concentrations. Thus, a semiconductor device in which the size of the gate electrode can be readily controlled and damage to the semiconductor substrate or the like can be suppressed, is obtained.