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:
Sep. 22, 1992
Filed:
Apr. 15, 1991
Yuuichi Mikata, Yokohama, JP;
Toshiro Usami, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a semiconductor memory device having a floating gate structure, the floating gate electrode is composed of 2 to 10 silicon grains. With the floating gate electrode, the insulation film, formed on the floating gate electrode, can have a high breakdown voltage. In a method of manufacturing a semiconductor memory device having a floating gate structure, an insulation film is formed on the silicon substrate, portions of the insulation film which are on the drain and source forming regions of the silicon substrate are removed, and a silicon layer is formed on the silicon substrate by an epitaxial growth process, constituting a floating gate, composed of 2 to 10 silicon grains. According to the manufacturing method, the insulation film formed on the floating gate electrode can have a high breakdown voltage.