Nanosheet channel-to-source and drain isolation
US9620590B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2016 |
| Grant date | Apr 11, 2017 |
| Priority date | — |
| Expiry date | Sep 20, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/251
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method and structures are used to fabricate a nanosheet semiconductor device. Nanosheet fins including nanosheet stacks including alternating silicon (Si) layers and silicon germanium (SiGe) layers are formed on a substrate and etched to define a first end and a second end along a first axis between which each nanosheet fin extends parallel to every other nanosheet fin. The SiGe layers are undercut in the nanosheet stacks at the first end and the second end to form divots, and a dielectric is deposited in the divots. The SiGe layers between the Si layers are removed before forming source and drain regions of the nanosheet semiconductor device such that there are gaps between the Si layers of each nanosheet stack, and the dielectric anchors the Si layers. The gaps are filled with an oxide that is removed after removing the dummy gate and prior to forming the replacement gate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.