Good to use a Titanium metal target, and do reactive temperature.

Polycrystalline deposits of TiO2 can be obtained by RF sputtering at an appropriate power say (300 Watts on a 4 inch dia target), and a suitable sputtering gas ambient of Ar+O2 gas mixture.

TiO2 can crystallise either in the Rutile or the Anatase form.

Achieving Rutile phase demands higher substrate temperature .

Check the literature on what has been done so far on sputtered TiO2 coatings to get an idea on the substrate temperature.

Alternately you can deposit at a lower temperature, and post anneal your films to obtain a crystalline TiO2 layer. Try to select substrate that can withstand high temperature (such as fused quartz, or oxidised silicon substrates), as you will be annealing at quite high a temperature (> 400 deg C. You may have to optimise your annealing temperature.

K. Sreenivas