Selective silicidation process using a titanium nitride protective layer
US4920073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1989 |
| Grant date | Apr 24, 1990 |
| Priority date | — |
| Expiry date | May 11, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/147
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method for inhibiting the oxidation of a titanium layer during the direct reaction of the titanium with exposed silicon areas of an integrated circuit. In one embodiment of the present invention, a titanium nitride layer is formed on the surface of the titanium layer in the reactor where the titanium layer is deposited. The titanium nitride layer provides an effective barrier against oxidation. Thus, the formation of titanium dioxide is inhibited. In addition, in those areas where titanium nitride local interconnect is to be formed between diffused areas, the extra thickness provided by the top titanium nitride layer adds in the integrity of the conductive layers. By conducting the silicidation in a nitride atmosphere, diffusion of the nitride from the titanium nitride layer into the titanium layer and substitution of those lost nitrogen atoms by the atmosphere occurs thus providing a blocking layer for the formation of titanium silicide shorts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.