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:
Jul. 23, 2019
Filed:
Dec. 04, 2017
Renesas Electronics Corporation, Tokyo, JP;
Seiji Kumagae, Hitachinaka, JP;
Kazuyuki Ozeki, Hitachinaka, JP;
Katsuyoshi Kogure, Hitachinaka, JP;
RENESAS ELECTRONICS CORPORATION, Tokyo, JP;
Abstract
In a split-gate-type MONOS memory, increase in a defective rate due to variation in a gate length of a memory gate electrode is prevented, and reliability of a semiconductor device is improved. A first dry etching having a high anisotropic property but a low selection ratio relative to silicon oxide is performed to a silicon film, and then, a second dry etching having a low anisotropic property but a high selection ratio relative to silicon oxide is performed thereto, so that a control gate electrode composed of the silicon film is formed, and then, a sidewall-shaped memory gate electrode is formed on a side surface of the control gate electrode. In this case, respective etching amounts of the first dry etching and the second dry etching are controlled by determining a length of etching time in accordance with desired characteristics of a manufactured memory and a film thickness of the silicon film in the first dry etching, based on an etching time setting table, so that a gate length of the memory gate electrode is controlled.