Multi-patterning to form vias with straight profiles
US9679804B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 2016 |
| Grant date | Jun 13, 2017 |
| Priority date | — |
| Expiry date | Jul 29, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76829
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method includes forming a carbon-containing layer with a carbon atomic percentage greater than about 25 percent over a first hard mask layer, forming a capping layer over the carbon-containing layer, forming a first photo resist over the capping layer, and etching the capping layer and the carbon-containing layer using the first photo resist as a first etching mask. The first photo resist is then removed. A second photo resist is formed over the capping layer. The capping layer and the carbon-containing layer are etched using the second photo resist as a a second etching mask. The second photo resist is removed. A third photo resist under the carbon-containing layer is etched using the carbon-containing layer as etching mask. A dielectric layer underlying the third photo resist is etched to form via openings using the third photo resist as etching mask. The via openings are filled with a conductive material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.