Method for forming a buried metal line
US11335597B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 2020 |
| Grant date | May 17, 2022 |
| Priority date | — |
| Expiry date | Aug 1, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/038
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming a buried metal line in a substrate includes forming, at a position between a pair of semiconductor structures protruding from the substrate, a metal line trench in the substrate at a level below a base of each semiconductor structure of the pair. Forming the metal line trench includes etching an upper trench portion in the substrate, forming a spacer on sidewall surfaces of the upper trench portion that expose a bottom surface of the upper trench portion, and, while the spacer masks the sidewall surfaces, etching a lower trench portion by etching the substrate via the upper trench portion such that a width of the lower trench portion exceeds a width of the upper trench portion. The method further includes forming the metal line in the metal line trench.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.