Highly reliable amorphous high-k gate dielectric ZrOXNY
US6767795B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 2002 |
| Grant date | Jul 27, 2004 |
| Priority date | — |
| Expiry date | Jan 17, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02252
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A gate dielectric and method of fabricating a gate dielectric that produces a more reliable and thinner equivalent oxide thickness than conventional SiO2 gate oxides are provided. Gate dielectrics formed from metals such as zirconium are thermodynamically stable such that the gate dielectrics formed will have minimal reactions with a silicon substrate or other structures during any later high temperature processing stages. The addition of nitrogen to the microstructure of the gate dielectric promotes an amorphous phase that further improves the electrical properties of the gate dielectric. The process shown is performed at lower temperatures than the prior art, which inhibits unwanted species migration and unwanted reactions with the silicon substrate or other structures. By using a thermal evaporation technique to first deposit a metal layer, the underlying substrate surface smoothness is preserved, thus providing improved and more consistent electrical properties in the resulting gate dielectric.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.