W chemical-vapor deposition using (i-C3H7C5H4)2WH2

One of the most popular refractory metals is tungsten or W. Therefore, W chemical-vapor deposition (CVD) is expected to be useful for nanotechnology applications. In some cases, the residual atoms, such as halogen and oxygen, in films may degrade their quality. The authors therefore propose (i-C3H7C5H4)2WH2, i.e., (i-PrCp)2WH2, as a new W precursor because the authors expect some advantages from the absence in this molecule of the F and O that exist in the popular W precursors, WF6 and W(CO2)6. The melting point of (i-PrCp)2WH2 is 30°C and the precursor has a high vapor pressure of 0.1torr at 110°C. The authors conducted W CVD with the (i-PrCp)2WH2 as a precursor and obtained conformal W thin film. The deposition rate was 69nm∕min at 750°C, and the deposited film had resistivity of 2.3×10−4Ωcm. However, the deposited film included a tremendous amount of C. Therefore, investigating the possibility of reducing the C contamination is necessary.