Method of reducing the trap density of an oxide film for application to fabricating a nonvolatile memory cell
US5279981A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1992 |
| Grant date | Jan 18, 1994 |
| Priority date | — |
| Expiry date | Apr 15, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/91
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention is intended to provide a method of fabricating an EEPROM having excellent endurance characteristics. A work obtained by processing a substrate (1) by a wafer processing process including a passivating process and having a tunnel oxide film, an aluminum wiring film and a passivation film is subjected to a low-temperature heat treatment employing a processing temperature of about 250.degree. C. and a processing time on the order of 50 hr in a thermostatic oven (20) in the presence of nitrogen gas. The low-temperature heat treatment reduces trap sites produced in the tunnel oxide film by a plasma CVD process carried out to form the passivation film to repair the tunnel oxide film damaged by the plasma CVD process and to improve the endurance characteristics. The aluminum wiring film is not deteriorated by the low-temperature heat treatment because the low-temperature heat treatment employs a relatively low processing temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.