Nitridation of titanium, for use with tungsten filled contact holes
US5552340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1995 |
| Grant date | Sep 3, 1996 |
| Priority date | — |
| Expiry date | Oct 27, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76877
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process has been developed that allows small diameter contact holes to be filled with chemical vapor deposited tungsten, without tungsten peeling from the sides of the contact hole. The process consists of initially depositing an adhesive layer of titanium in the contact hole, followed by a rapid thermal anneal cycle, in an ammonia ambient, for purposes of creating a thin, uniform, barrier layer of titanium nitride. The titanium nitride protects the underlying titanium adhesion layer from the by-products introduced during the tungsten deposition, specifically the evolution of fluorine ions resulting from the decomposition of tungsten hexafluoride.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.