Optimum substrate bias condition for TiN thin film deposition using an ECR sputter system

The plasma parameters and ion bombardment energy were quantitatively investigated to find the optimum condition and the correlation between the plasma conditions and film properties. The electron density (ne) of approximately 1017/m3 was obtained in the substrate region under the condition where gas pressure was 1 mTorr and both power of the microwave and RF source were 500 W, and the electron temperature (Te) and ion saturation current (I0) were in the range of 3–5 eV and 1–1.5 mA/cm2, respectively. High resistivity of TiN films above −50 V bias was attributed to the amorphization of TiN films by ion bombardment effect, which was confirmed by X-ray diffraction analysis. It was found that there was an optimum bias voltage for best-quality TiN film formation, which showed a strong correlation with the ion bombardment energy.