Method of manufacturing a semicondutor integrated circuit device having nonvolatile memory cells
US5814543A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1995 |
| Grant date | Sep 29, 1998 |
| Priority date | — |
| Expiry date | Nov 22, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B69/00
Abstract
A method for fabricating a semiconductor integrated circuit device comprising a nonvolatile memory cell, comprises the steps of forming a first gate material which comprises a silicon film containing no impurities, whose top surface is covered with an oxidation-resistant mask, and whose width in the gate-length direction is prescribed, on part of the surface of a first gate insulating film, forming a thermal-oxidation insulating film on the surface of an active region of a semiconductor substrate through thermal oxidation, removing an oxidation-resistant mask, forming a second gate material which comprises a silicon film into which impurities are introduced and whose width in the gate-length direction is prescribed, on each surface of the thermal-oxidation insulating film and the first gate material forming a second gate insulating film on the surface of the second gate material, and forming a third gate material on the surface of the second gate insulating film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.