I am trying to reactively sputter alumina and zirconia. I have a Denton Vacuum Explorer 14 system with 3 DC magnetron sputtering guns and 1 RF magnetron gun. The gases are introduced into the chamber via MKS MFCs. Argon line came with the sputtering system, and I modified the system to add oxygen and nitrogen gas lines. The argon and oxygen mix in the same line going to the chamber. I've been doing experiments and have not had any luck with good results. Typical parameter used: 200W, 25 sccm Ar, varying O2 flow to get a good film, have tried from 1-30 sccm, sputter pressure around 3-5 mtorr, and sputter time from 1-2 hours.

Is reactive sputtering of aluminum oxide with either DC or RF power possible without substrate bias, substrate heating, arc suppression, or pulsed DC power? Most papers I have read have done one of these to get reactive sputtering to work, but I want to know if it can be achieved without modifying my system even more.