Method of preventing trench distortion
US9741614B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2016 |
| Grant date | Aug 22, 2017 |
| Priority date | — |
| Expiry date | Jul 11, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76816
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of forming trenches and a via by self-aligned double patterning includes providing a dielectric layer covered by an SiOC layer, a TiN layer and a SiON layer from top to bottom. At least two mandrels are formed on the SiOC layer. Later, two spacers are formed respectively at two sidewalls of each mandrel. Subsequently, the mandrels are removed. The SiOC layer and the TiN layer are patterned by using the spacers to form numerous recesses. The spacers are then removed. A mask layer with a via pattern is formed to cover the SiOC layer. A via is formed in the dielectric layer by taking the mask layer as a mask. After that, the mask layer is removed. Finally, numerous trenches are formed in the dielectric layer by taking the SiOC layer and the TiN layer as a mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.