Comparative study of titanium and chromium transition layers on quartz substrates

Abstract

As an important functional material, quartz needs to be firmly welded with electrodes through a transition layer—such as a Ti or Cr film—for practical applications. It is important to understand the microstructure of the transition layer and its interfacial structure with quartz to improve the reliability of corresponding devices. The present authors conducted a systematic comparative study on Ti and Cr thin films deposited on the surface of quartz. The distribution and valence of elements on the film–substrate interface were analyzed by X-ray photoelectron spectroscopy. The grain size and defect distribution in the films, as well as the morphology and composition distribution at the film–substrate interface, were characterized by transmission electron microscopy in combination with energy-dispersive spectrometry. The phase and preferred orientation of the films were measured by X-ray diffraction. The bonding force between the Ti and Cr films and quartz was investigated through nanoscratch experiments. Fracture analysis of the delaminated films was carried out by Auger electron spectrometry. Substantial chemical bonding was generated at the Ti–quartz interface, and there were no detectable micro-defects, resulting in high bonding strength. During deposition of the Cr film, there was substantial atomic peening, resulting in a nanoscale damage layer on the surface of quartz, facilitating delamination in scratch experiments.