Method for forming a transistor gate dielectric with high-K and low-K regions
US6406945B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 2001 |
| Grant date | Jun 18, 2002 |
| Priority date | — |
| Expiry date | Jan 26, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S257/90
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming a gate dielectric having regions with different dielectric constants. A dummy dielectric layer is formed over a semiconductor structure. The dummy dielectric layer is patterned to form a gate opening. A high-K dielectric layer is formed over the dummy dielectric and in the gate opening. A low-K dielectric layer is formed on the high-K dielectric layer. Spacers are formed on the low-K dielectric layer at the edges of the gate opening. The low-K dielectric layer is removed from the bottom of the gate opening between the spacers. The spacers are removed to form a stepped gate opening. The stepped gate opening has both a high-K dielectric layer and a low-K dielectric layer on the sidewalls and at the edges of the bottom of the gate opening and only a high-k dielectric layer in the center of the bottom of the stepped gate opening. A gate electrode is formed in the stepped gate opening.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.