Buried word line structure and method of making the same
US10217750B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 21, 2017 |
| Grant date | Feb 26, 2019 |
| Priority date | — |
| Expiry date | Sep 21, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/488
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of fabricating a buried word line structure includes providing a substrate with a word line trench therein. Two source/drain doped regions are disposed in the substrate at two sides of the word line trench. Later, a silicon oxide layer is formed to cover the word line trench. A titanium nitride layer is formed to cover the silicon oxide layer. Next, a tilt ion implantation process is performed to implant silicon atoms into the titanium nitride layer to transform part of the titanium nitride layer into a titanium silicon nitride layer. A conductive layer is formed in the word line trench. Subsequently, part of the conductive layer, part of the titanium silicon nitride layer and part of the silicon oxide layer are removed to form a recess. Finally, a cap layer fills in the recess.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.