Forming contact holes using litho-etch-litho-etch approach
US11515159B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 2020 |
| Grant date | Nov 29, 2022 |
| Priority date | — |
| Expiry date | Dec 29, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76832
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention further provides a method for forming a semiconductor device, the method including: first, a target layer is provided, an etching stop layer is formed on the target layer, a top oxide layer is formed on the etching stop layer, afterwards, a first photoresist layer is formed on the top oxide layer, and a first etching process is then performed, to form a plurality of first trenches in the top oxide layer. Next, a second photoresist layer is formed on the top oxide layer, portion of the second photoresist layer fills in each first trench, a second etching process is then performed to form a plurality of second trenches in the top oxide layer, and using the remaining etching stop layer as a hard mask, a third etching process is performed to remove parts of the etching stop layer and parts of the target layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.