Properties of Ti-doped Al2O3 thin films deposited by simultaneous RF and DC magnetron sputtering

• Low DC power or high oxygen pressure made the Al2O3:Ti film be more stoichiometric.
• Increasing the DC power made the hydrophilic Al2O3:Ti film be rougher.
• High visible transmission was obtained at low DC power or high oxygen pressure.
• High linear refractive index was obtained at low DC power or high oxygen pressure.

The Ti-doped Al2O3 (Al2O3:Ti) films were prepared by simultaneous RF magnetron sputtering of Al2O3 and DC magnetron sputtering of Ti. The advantage of this method is that the Ti content could be independently controlled. Decreasing the DC power or increasing the ratio of O2 to Ar pressure made the Al2O3:Ti film be more stoichiometric. By decreasing the DC power or increasing the ratio of O2 to Ar pressure, the hydrophilic Al2O3:Ti film exhibited lower surface roughness, higher average visible transmission, higher linear refractive index and lower stress-optical coefficient.