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:
Feb. 25, 2003
Filed:
Apr. 18, 2000
Mizuki Segawa, Osaka, JP;
Masatoshi Arai, Nara, JP;
Toshiki Yabu, Toyama, JP;
Shunsuke Kugo, Toyama, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
After P ions are implanted into a polysilicon film in an nMOSFET region, a heat treatment is performed to diffuse phosphorus down to the lower part of the polysilicon film. The diffusion reduces the concentration of phosphorus in an upper end portion of the polysilicon film and inhibits the upper end edges of a gate electrode from being increased in size during patterning. Then, B ions are implanted into the polysilicon film in a pMOSFET region and the polysilicon film is etched into a gate configuration. Since a heat treatment for simultaneously diffusing phosphorus and boron in the polysilicon film is not performed, the entrance of boron from the gate electrode into a semiconductor substrate is inhibited, while the occurrence of side etching during the formation of an n-type polysilicon gate is suppressed.