Non-volatile semiconductor memory device and manufacture thereof

Abstract

Abstract PURPOSE:To enable to simply manufacture a non-volatile semiconductor memory device which has stable threshold voltage by adjacently disposing a 2-layer insulated gate type field effect non-volatile transistor and a single layer insulated gate type field effect transistor under the same gate electrode. CONSTITUTION:n<+> type source and drain regions 12, 13 are isolated and formed in a memory cell forming part on a P type Si substrate 11, source and drain regions 14, 15 are isolated and formed in the peripheral circuit forming part, and a field oxidized film 16 is formed on the surface except the regions 12- 15. Then, a gate insulated film 18 and a gate oxidized film 19 are formed at the MNOS transistor forming part. Subsequently, with the film 18 as a mask, a thick gate oxidized film 20 is formed adjacent to the peripheral MOS transistor forming part of the memory cell by a thermal oxidation. Thereafter, the same gate electrodes 24-27 are formed on the regions 12-15.

Inventors

• 👤 Shozo Saito
• 👤 斎藤　昇三

Bibliographic Details