In my setup, I am intending to evaporate gold on mica substrate. After that, I intend to clean the gold surface and smooth it using nitrogen plasma (as we have some problems related to the vacuum if we use hydrogen). I looked up at the literature and found no article about that (they investigated hydrogen, argon, and oxygen so far). What could be the drawbacks or precautions that I need to put in mind? Any advice?
It is possible. Whether it's Ar, N2, H2 or O2, gold and mica substrate does not react with any of these gases.
I guess Ar makes a lot of roughness and I need the surface to be as flat as possible.
Then you need a light gas like H2 or He, nitrogen will hardly be different from argon.
Surface treatment of metals using an atmospheric pressure plasma jet and their surface characteristic, September 2003, Surface and Coatings Technology 174(175):839-844, DOI: 10.1016/S0257-8972(03)00560-7
The above article is very nice. please go through this article. It might be useful for you.
Dear Muhhammad,
It is possible. You can follow some of references. On the based of references I am quoting inference(https://iopscience.iop.org/article/10.1088/1742-6596/100/1/012034/pdf).
The plasma cleaning with mixed gas (Ar + O2) effectively decreased the carbon content on the surface, but increased the gold oxide content(because oxygen in mixture is getting added). Better to use effective pure Ar gas which can decreased the contaminants, such as carbides and oxides, on the surface without the gold oxide formation, thereby improving the bonding strength. Atmospheric pressure plasma cleaning of Au flip chip can be possible with different gases and processing times. The plasma cleaning for 1 s with pure Ar gas was effective for the ultrasonic bonding. An addition of O2 to Ar decreased the bonding strength between the Au bump and Au substrate.
Ashish
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