1989 Volume 53 Issue 1 Pages 114-118
This study was carried out to find various factors affecting the adherence of a chemical-vapor-deposited (CVD) tungsten (W) thin film to the SiO2 substrate. This was done by correlating this adherence with the results of W/SiO2 interface characterization by ESCA (Electron Spectroscopy for Chemical Analysis). The amount of W remaining after the W film was peeled off from the thermally oxidized silicon substrate was taken as a measure of adherence. For interface characterization, W and SiO2 surfaces exposed after the above peeling-off were examined by ESCA. It was found that (1) the adherence of oxidized W to SiO2 is better than that of metallic W to SiO2. Hence, there is a correlation between the amount of oxidized W at the W/SiO2 interface and the W/SiO2 adherence, (2) this adherence is better if there is less fluorine (which comes from WF6 gas used for CVD) at the interface.
