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. 01, 2014
Filed:
Sep. 04, 2012
Masaki Kondo, Kawasaki, JP;
Nobutoshi Aoki, Yokohama, JP;
Takashi Izumida, Yokohama, JP;
Tomomi Yoda, Yokohama, JP;
Masaki Kondo, Kawasaki, JP;
Nobutoshi Aoki, Yokohama, JP;
Takashi Izumida, Yokohama, JP;
Tomomi Yoda, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
According to one embodiment, a nonvolatile semiconductor memory device includes a semiconductor substrate, a gate insulating film formed on the semiconductor substrate, a floating gate electrode formed on the gate insulating film, made of polysilicon containing a p-type impurity as a group XIII element, and having a lower film and an upper film stacked on the lower film, an inter-electrode insulating film formed on the floating gate electrode, and a control gate electrode formed on the inter-electrode insulating film. One of a concentration and an activation concentration of the p-type impurity in the upper film is higher than one of a concentration and an activation concentration of the p-type impurity in the lower film.