Non-volatile semiconductor memory device and manufacturing method thereof

US6818508B2 · kind B2 · utility

Assignee

• Kabushiki Kaisha Toshiba · JP

Inventors

• Kazuhiro Shimizu · Yokohama, JP
• Yuji Takeuchi · Kobe, JP

Key dates

• Filing date: Mar 24, 2003
• Grant date: Nov 16, 2004
• Expiry date: Mar 30, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B69/00

Abstract

A method of manufacturing a non-volatile semiconductor memory device, including forming a first gate insulating film, on a semiconductor substrate; forming a first conductive layer as the lowest layer of a charge-storage layer on the first gate insulating film; forming a masking material on the first conductive layer; etching the masking material, the first conductive layer, the first gate insulating film and the substrate so that side end portions thereof meet each other to form a trench; oxidizing a side wall of the trench and a side-wall surface of the first conductive layer; filling the trench with an isolation insulating film; exposing and peeling off the masking material to expose the upper surface of the first conductive layer; depositing a second conductive layer, which is the highest layer of the charge-storage layer, on the substrate; flattening the second conductive layer to be flush with the upper surface of the isolation insulating film; forming a second gate insulating film on the second conductive layer and the isolation insulating film; and forming a control gate material on the second gate insulating film.