A study on the nanostructured W-Ti thin films deposited on Si

摘要

The W(90%)-Ti(10%) wt% alloy target is prepared and the W-Ti thin films are deposited by the dc Ar ~+ sputtering on silicon substrates. The morphology, composition, and microstructure of the alloy and thin films were observed. The structure was undertaken using X-ray diffraction (XRD). The morphology was determined by scanning electron microscopy with energy dispersive spectrometer (SEM-EDS) and high-resolution transmission electron microscopy (HRTEM). The surface composition and chemical bonding of elements on the Ti-W thin films after deposition and exposed to air were analyzed by X-ray photoelectron spectroscopy (XPS). The results show the structure evolves from amorphous film to dual phase (bcc W and bcc Ti) followed by uniform β-phase solid solution with increasing sputtering power. The sputtering power and bias voltage also have great effect on the resistivity of the W-Ti thin films.