neo man:

Try etching thru approximately 90% of your film and then change your power
settings to around 50 watts rf for the remaining film. Using C4F8 or CHF3 should
also help but I think you are sputter etching the gold by applying too much
power and etching too long. Do you have an endpoint system that you can use to
determine when the oxide is beginning to clear? Good luck  Bob Henderson