Method and apparatus for etching thin layer
US11495467B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 2020 |
| Grant date | Nov 8, 2022 |
| Priority date | — |
| Expiry date | Jun 10, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for etching a thin layer including silicon nitride formed on a substrate are disclosed. Etchant including phosphoric acid and water is supplied on the substrate so that a liquid layer is formed on the substrate. The thin layer is etched by reaction between the thin layer and the etchant. Thickness of the liquid layer is measured to detect variation in the thickness of the liquid layer while etching the thin layer. Variation in the concentration of the phosphoric acid and the water is calculated based on the variation in the thickness of the liquid layer. Water is supplied on the substrate based on the variation in the concentration of the phosphoric acid and the water so that the concentration of the phosphoric acid and the water becomes a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.