Method of manufacturing a semiconductor integrated circuit device
US6677194B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2002 |
| Grant date | Jan 13, 2004 |
| Priority date | — |
| Expiry date | Jul 9, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/038
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A low threshold voltage NMIS area and a high threshold voltage PMIS area are set by a photoresist mask also used for well formation. Using a photoresist mask with openings for the NMIS and PMIS, the NMIS and PMIS areas are set by one ion implantation step. After gate oxidation, ion implantation is conducted through an amorphous silicon film onto wells, channels, and gate electrodes. A plurality of CMIS threshold voltages can be set and the gate electrodes of both polarities can be formed in a reduced number of steps using photoresist. This solves the problem in which photomasks are required as many as there are ion implantation types for wells, channel stoppers, gate electrodes, and threshold voltage control and hence the number of manufacturing steps and the production cost are increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.