Method of fabricating a field effect transistor structure with abrupt source/drain junctions
US7436035B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 2004 |
| Grant date | Oct 14, 2008 |
| Priority date | — |
| Expiry date | May 11, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/017
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Microelectronic structures embodying the present invention include a field effect transistor (FET) having highly conductive source/drain extensions. Formation of such highly conductive source/drain extensions includes forming a passivated recess which is back filled by epitaxial deposition of doped material to form the source/drain junctions. The recesses include a laterally extending region that underlies a portion of the gate structure. Such a lateral extension may underlie a sidewall spacer adjacent to the vertical sidewalls of the gate electrode, or may extend further into the channel portion of a FET such that the lateral recess underlies the gate electrode portion of the gate structure. In one embodiment the recess is back filled by an in-situ epitaxial deposition of a bilayer of oppositely doped material. In this way, a very abrupt junction is achieved that provides a relatively low resistance source/drain extension and further provides good off-state subthreshold leakage characteristics. Alternative embodiments can be implemented with a back filled recess of a single conductivity type.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.