Gate formation process
US11264282B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 2020 |
| Grant date | Mar 1, 2022 |
| Priority date | — |
| Expiry date | Jun 28, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/0151
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Processes to form differently-pitched gate structures are provided. An example method includes providing a workpiece having a substrate and semiconductor fins spaced apart from one another by an isolation feature, depositing a gate material layer over the workpiece, forming a patterned hard mask over the gate material layer, the patterned hard mask including differently-pitched elongated features, performing a first etch process using the patterned hard mask as an etch mask through the gate material layer to form a trench, performing a second etch process using the patterned hard mask as an etch mask to extend the trench to a top surface of the isolation feature, and performing a third etch process using the patterned hard mask to extend the trench into the isolation feature. The first etch process includes use of carbon tetrafluoride and is free of use of oxygen gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.