Method for selective tungsten sidewall and bottom contact formation
US5504038A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1995 |
| Grant date | Apr 2, 1996 |
| Priority date | — |
| Expiry date | May 25, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76879
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A structure and method is provided for forming a contact plug in a contact hole in a dielectric layer on a semiconductor substrate. A polysilicon spacer is formed on the sidewalls and bottom of the contact hole. A metal, such as titanium, is deposited on the sidewalls and bottom of the hole and on the dielectric layer. The substrate is heated to form a metal silicide layer, such as TiSi.sub.x, and a metal nitride layer, such as TiN, on the side-walls and bottom of the contact hole. Any remaining metal layer and metal nitride layer formed in the heating process is removed. This leaves the titanium silicide layer on the contact hole walls. Tungsten is deposited to fill the contact hole where the metal silicide promotes the nucleation of the tungsten. In a preferred embodiment, to further promote nucleation of the tungsten, a second metal nitride layer is formed on the surface; of the metal silicide layer just prior to tungsten deposition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.