Method for lowering the phase transformation temperature of a metal silicide
US5510295A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1993 |
| Grant date | Apr 23, 1996 |
| Priority date | — |
| Expiry date | Oct 29, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/147
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The phase transformation temperature of a metal silicide layer formed overlying a silicon layer on a semiconductor wafer is lowered. First, a refractory metal is disposed proximate to the surface of the silicon layer, a precursory metal is deposited in a layer overlying the refractory metal, and the wafer is heated to a temperature sufficient to form the metal silicide from the precursory metal. The precursory metal may be a refractory metal, and is preferably titanium, tungsten, or cobalt. The concentration of the refractory metal at the surface of the silicon layer is preferably less than about 10.sup.17 atoms/cm.sup.3. The refractory metal may be Mo, Co, W, Ta, Nb, Ru, or Cr, and more preferably is Mo or Co. The heating step used to form the silicide is performed at a temperature less than about 700.degree. C., and more preferably between about 600.degree.-700.degree. C. Optionally, the wafer is annealed following the step of disposing the refractory metal and prior to the step of depositing the precursory metal layer. Preferably, this annealing step is performed at a wafer temperature of at least about 900.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.