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. 02, 2013
Filed:
Dec. 21, 2010
Takashi Hiroshima, Ota, JP;
Takashi Hiroshima, Ota, JP;
SANYO Semiconductor Co., Ltd., Ora-gun, JP;
Semiconductor Components Industries, LLC, Phoenix, AZ (US);
Abstract
The invention enhances program performance by increasing a coupling ratio between an N+ type source layer and a floating gate and reduces a memory cell area. Trenches are formed on the both sides of an N+ type source layer. The sidewalls of the trench includes first and second trench sidewalls that are parallel to end surfaces of two element isolation layers, a third trench sidewall that is perpendicular to the STIs, and a fourth trench sidewall that is not parallel to the third trench sidewall. The N+ type source layer is formed so as to extend from the bottom surface of the trench to the fourth trench sidewall, largely overlapping a floating gate, by performing ion-implantation of arsenic ion or the like in a parallel direction to the third trench sidewall and in a perpendicular direction or at an angle to a P type well layer from above the trench having this structure.