Recessed workfunction metal in CMOS transistor gates
US8377771B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2012 |
| Grant date | Feb 19, 2013 |
| Priority date | — |
| Expiry date | May 23, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/691
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A transistor gate comprises a substrate having a pair of spacers disposed on a surface, a high-k dielectric conformally deposited on the substrate between the spacers, a recessed workfunction metal conformally deposited on the high-k dielectric and along a portion of the spacer sidewalls, a second workfunction metal conformally deposited on the recessed workfunction metal, and an electrode metal deposited on the second workfunction metal. The transistor gate may be formed by conformally depositing the high-k dielectric into a trench between the spacers on the substrate, conformally depositing a workfunction metal atop the high-k dielectric, depositing a sacrificial mask atop the workfunction metal, etching a portion of the sacrificial mask to expose a portion of the workfunction metal, and etching the exposed portion of the workfunction metal to form the recessed workfunction metal. The second workfunction metal and the electrode metal may be deposited atop the recessed workfunction metal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.