Which oxide improve the gold adhesion

armandowww

Hi everybody,
I need to deposit 50 nm of gold on a transparent oxide layer.
I need that this oxide layer would have a refractive index of 2, at the wavelenght 1.5 micron (infrared). I first tried with SiO2 but as many of you know the adhesion is very poor. Then I tried with ZrO2 and it doesn't seem to go better. Finally, Y2O3 seemed to be the best solution.
If some of you have any experience in thin films, do you confirm this behavior?
Have you some suggestion of some other materials?
Many thanks...

rmw228

I wouldn't expect you'll get a very good adhesion with gold on any oxide. A good interface between an oxide and gold would require some sharing of the metal sublattice, and as gold is one of those super-annoying noble metals, I can't see you getting a very good bond.

gccphys

I may have and idea, but no guarantees. I'm not exactly sure what you are doing, but like you, in my experience, gold won't stick to silicon. I'm not doing anything with optics, so we found that if we replace the target in our magnetron sputtering with copper (basically a piece of sheet metal from a roofing store), we can sputter thin films of copper on silicon that seem to be adhesive (not tested the strength of the bond, but it works, which is good enough for me). When you heat up a silicon substrate with a thin film of copper, the film does not peel and crack, like gold (though it does oxidize). I've found copper oxidizes fairly easily (in fact, we often deposit copper oxide if the chamber is not well evacuated of oxygen). So to get around that, we deposit gold on top of it again. Sounds like what you need. What I don't know is whether or not copper absorbs at 1.5um. But in terms of adhesion, I think it should work.

singhamol

Dear
You can deposit a layer of chromium in between SiO2 and Au then it will be extremely high adhesive. It passes all the tastes even scratch and soldering tastes also. if you need less adhesion you can deposit nickel also in between SiO2 and Au.