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:
Jan. 20, 1987
Filed:
Apr. 23, 1985
Yoshihisa Mizutani, Tokyo, JP;
Kabushiki Kaisha Toshiba, , JP;
Abstract
A method of producing a semiconductor device comprises an isolation step for forming an n-type region in contact with p.sup.+ -type source and drain regions of a p-channel floating gate MOS transistor in the surface area of an n-type semiconductor substrate and an n.sup.+ -type region in contact with the n-type region. In this isolation step, and oxidation resistant film pattern is formed on the element region of the MOS transistor. An anisotropic etching is applied to the substrate with the oxidation resistant film pattern used as a mask to form an inclined portion and a flat portion, followed by forming a SiO.sub.2 film of a prescribed thickness to cover both the inclined and flat portions. Further, an n-type impurity is introduced by ion implantation into the substrate through the SiO.sub.2 film in a direction perpendicular to the flat portion, followed by annealing the ion-implanted region.