Method of removing hard mask layer
US12040189B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 2022 |
| Grant date | Jul 16, 2024 |
| Priority date | — |
| Expiry date | Nov 16, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/021
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of removing a hard mask layer includes providing a gate. A hard mask layer covers and contacts a top surface of the gate. Two spacer structures respectively contacts two sides of the gate. Two first spacers are respectively disposed on the two spacer structures. Later, a wet etching process is performed to remove the hard mask layer and the first spacers and keep the spacer structures. An etchant is utilized in the wet etching process. A selective etching ratio of the silicon nitride to silicon oxide of the etchant is more than 90. The etchant includes Si(OH)4. A concentration of Si(OH)4. is greater than or equal to 3.95 ppm and smaller than or equal to 10 ppm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.