Manufacturing method of non-volatile semiconductor memory device
US5188976A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1991 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Jul 9, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/038
Abstract
Before a high permittivity interlayer insulating film of a non-volatile memory having a two-level gate electrode structure, a surface of a substrate in a peripheral circuit MOS area is successively covered with a thermal oxide film and a polycrystalline silicon film. Before the interlayer insulating film is selectively removed on the peripheral circuit MOS area, the surface of the interlayer insulating film of the non-volatile memory is covered with a polycrystalline silicon film. When the interlayer insulating film in the peripheral circuit MOS area is removed, the polycrystalline silicon film as a lower layer in the peripheral circuit area serves as a buffer layer against contamination or damage due to the etching, and the conductive layer on the surface of the interlayer insulating film in the non-volatile memory portion also serves as a buffer layer against the contamination or damage due to the etching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.