Method for selective etching at an interface between materials
US11133194B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2020 |
| Grant date | Sep 28, 2021 |
| Priority date | — |
| Expiry date | Feb 20, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D30/6757
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of etching a substrate includes generating plasma comprising a first concentration of an etchant and a second concentration of an inhibitor and etching the substrate by exposing an exposed interface between a first material and a second material to the plasma. The first material includes a lower reactivity to both the etchant and the inhibitor than the second material. The first concentration is less than the second concentration. Etching the substrate includes etching the first material and the second material at the exposed interface to form an etched indentation including an enriched region of the second material, forming a passivation layer at the enriched region using the inhibitor, and etching the first material at the etched indentation. The passivation layer reduces an etch rate of the second material to a reduced rate that is less than an etch rate of the first material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.