CHARACTERIZATION OF CHEMICALLY VAPOR-DEPOSITED TUNGSTEN ON LOW-PRESSURE CHEMICALLY DEPOSITED AND REACTIVELY SPUTTERED TITANIUM NITRIDE FILMS

The growth of low-pressure chemical vapor deposition (LPCVD) tungsten on LPCVD-grown and reactively sputtered titanium nitride (TiN) films has been studied employing the x-ray photoelectron spectroscopy depth profiling technique. Two types of gas ambients were used to grow tungsten (W) films at a deposition temperature of 400-degrees-C. In one case, a very thin overlayer of W was formed on both types of TiN films by exposing the samples to WF6. The W thus deposited diffuses deep into the bulk of the reactively sputtered TiN film whereas it is confined to the W/TiN interface for the LPCVD-grown TiN film. In the second case, both types of TiN films were exposed to the WF6, SiH4, and H-2 ambient. No diffusion of W into any of the TiN films was observed.