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:
Apr. 03, 1990
Filed:
Feb. 27, 1989
Yasukazu Seki, Kanagawa, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
The present invention relates to a method of producing a vertical insulated gate field effect transistor. In the present invention a window portion is formed on a polysilicon layer which serves as a gate, by selectively etching the layer so as to leave the central portion intact. Ions of impurities are implanted while using the polysilicon layer having the window portion as a mask. Thereby a phase layer is formed and the ions of impurities are again implanted from the window portion, forming the N.sup.+ source region. Since this method is different from a conventional method in that positioning using a special resist mask is unnecessary, the N.sup.+ source region is formed by self alignment with a high efficiency and a high accuracy without any positional deviation caused by inaccurate positioning of a mask.