Selective CVD of tungsten and its applications to MOS VLSI

The selective low pressure chemical vapor deposition of tungsten (selective W-CVD) employing WF/sub 6/ is investigated in both the deposition mechanism and the applications to MOS VLSI technologies. In the practical use of the selective W-CVD, not only the encroachment phenomenon, but also selectivity breakdown must be overcome. These problems are resolved by the careful suppression of the silicon reduction of WF/sub 6/. The selective W-CVD technique is applied to VLSI devices with a submicron feature size and can resolve several difficult problems of the metallization for submicron devices