A critical comparison of silicide film deposition techniques

Three different film deposition techniques are compared. WSi 2 was chosen as a test sample. Fabrication of films with the desired composition and lowest electrical resistivities are emphasized. Rutherford backscattering analysis was found to be a very useful tool to perform rapid non-destructive examination of in-depth composition variation and determination of relative thickness. Co-evaporation of tungsten and silicon was found to provide films with the lowest resistivity but was the most difficult method of film deposition. Co-sputtering is slightly simpler than co-evaporation but it is preferable to sputter from a compound or composite target of high purity if available. Low pressure chemical vapor deposition is the simplest method for tungsten silicide film deposition with uniformity and high throughput. However, these films contain more impurities, and thus the resulting resistivities are higher than those of purer films deposited by other techniques.