Sorry for the misplaced sarcasm. I hadn't noticed the word gold in the subject line. In this case an adhesion layer of Ti or Cr would be appropriate. Roger Shile -----Original Message----- That depends. If you're going to evaporate water the surface should be hydrophilic. In this case oxidizing should do the trick. Roger Shile -----Original Message----- Hello I want to coat silicon with evaporation coating, and to assurance that the adhesion between the two materials will be optimal. What will be the optimal treatment to achieve adhesion ?