Selective low pressure chemical vapor deposition of tungsten for VLSI applications, part I: Film deposition and structure.

Tungsten (W) films have been selectively deposited (i.e., deposited on Si and TaSi2 to the exclusion of SiO2) by low pressure chemical vapor deposition via the reduction of WF6 by either Si or H2. Films formed by H2 reduction can be unlimited in thickness. However, those formed by Si reduction are self-limited in thickness to about 150angstroms due to the inability of WF6 to further react with the underlying Si once such a W film is formed.