The authors present data on the formation and structure of CVD W films deposited by the Si reduction of WF//6. Although the great majority of CVD W films deposited for IC applications are ostensibly deposited by H//2 reduction, the Si reduction of WF//6 always occurs first, even in the presence of copious amounts of H//2. Therefore, it is the Si reduction reaction that determines the nature of W/Si interface, and, in turn, such important properties as contact resistance and leakage current. We have found that Si reduced W films deposited between 210 degree and 700 degree C are porous and discontinuous, and are probably not effective barriers to the further diffusion of WF//6. The discontinuous structure of the films provides a simple mechanism for the growth of thick W films by Si reduction; such thick films have been observed with increasing frequency as of late and have been enigmatic, because the reaction between WF//6 and Si was thought to be self-limiting.
|Number of pages||8|
|Journal||Journal of the Electrochemical Society|
|Publication status||Published - Sep 1987|
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Surfaces and Interfaces