Selective and isotropic etch of silicon over silicon-germanium alloys and dielectrics; via new chemistry and surface modification
US12272558B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 2022 |
| Grant date | Apr 8, 2025 |
| Priority date | — |
| Expiry date | Aug 2, 2043 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/258
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Selective protection and etching is provided which can be utilized in etching of a silicon containing layer with respect to a Ge or SiGe layer. In an example, the layers are stacked, and an oxide is on a side surface of the layers. A treatment is utilized to provide a modified surface or termination surface on side surfaces of the Ge/SiGe layers, and a heat treatment is provided after the gas treatment to selectively sublimate layer portions on side surfaces of the Si containing layers. The gas treatment and heat treatment are preferably in non-plasma environments. Thereafter, a plasma process is performed to form a protective layer on the Ge containing layers, and the Si containing layers can be etched with the plasma.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.