Could you roughen the nafion by bombarding it with an ion beam before depositing the Au? That might improve adhesion. Perhaps you could even use the beam you're using to do the sputtering for that purpose.

Another strategy would be to deposit a thin layer of another metal on the nafion surface before depositing the gold. If the metal were selected appropriately, adhesion might be improved.

Also, try looking at the answers to the question "Is there anyone who knows about the interface adhesion between evaporated Au and a SiO2 layer? " that was posted on ResearchGate.

thank you

about Au and SiO2, it was my question!

i will try to roughen it and also deposit a thin layer like Ti on nafion.

Yeah it has been well explained by Bradley. You can also do one thing, try to vary the parameters of sputtering like change the power and see what happens. It may enhance adhesion between metal and polymer

As mentioned before, a thin layer of another metal can help improve the adhesion of the final gold layer. Specifically, I've had good luck sputtering ~10-20nm of chrome prior to the Au deposition.

Over SiO2 I have had better results with Cr, as Jonathan suggested, instead of Ti as you said you would try. I used a layer thicker than 10-20 nm (around 40 nm), but also saw works doing even thinner layers of Cr (around 5 nm). It will be better if you have a two-target system, so that you may do the two layers without breaking the vacuum. Another aspect to consider is whether you will need post process your sample (patterning and etching or patterning lifting-off ) because titanium etchant (almost always HF or BOE, which is also HF) also attacks SiO2, but chromium etchant (like transene 1020) does not. If you want to try Bradley´s suggestion to roughen the surface, you may also try a chemical process by immersing it (assuming it is SiO2 as you mentioned) very quickly (5 sec or less) in HF or BOE.

@Reneto Rabelo

Thanks for your suggestion but actually i want to deposit an Au layer as a electrode on a polymer membrane, not SiO2 layer.

Is it your suggestion feasible on polymer?

Hi Emad! I am sorry about getting it wrong. From your answer to Bradley´s suggestion on April 14, I assumed your problem was not only with nafion but also with SiO2. Concerning about depositing and intermediate metal layer between the polymer and the Au layer, I would give it a try (Chromium). Concerning the surface roughening, Bradley´s suggestion was right on the money: try using the plasma (before depositing, maybe in a pre-sputtering with a shutter over the target) to get the job done.

Try oxygen plasma treatment before deposition.

@Reneto Rabelo

Thanks again

about chromium, our sputtering machine doesn't have chromium target! and for deposit it i have to use E-Beam machine and after that i must break the vacuum and carry the sample to sputtering machine!

are you sure i can get better result by Cr?

and about plasma, which gas and flow rate and time and power! you can suggest?

@F. Molina-Lopez

can you suggest more detailed process?

Gold is very nasty element when it comes in adhesion part but we have to use because of its inertness. I was also suffering same problem with PDMS and PVDF polymers, while doing patterning of gold on this two polymers my gold came up because of bad adhesion. For getting rid of this I did oxygen plasma treatment for 10 sec, 200W power or you can do corona treatment to make polymer surface rough and I got good patterning without lift of gold layer.

So before doing sputtering do oxygen plasma or corona treatment. I hope you will get good adhesion.

Keep in touch

Nirul

@Emad Esmaeili. The process suggested by N. Masurkar sounds appropriated to me. I was trying similar power and 30 to 60 seconds but I did not observe big differences in adhesion strength within this time window. What it may be important is to sputter right after performing plasma treatment, i.e., do not wait long time in between steps or the effect of the plasma treatment may be degraded. If the adhesion is still not enough, you could use, as a plan B, a very thin (few nanometers thick) layer of Cr between polymer and Au to improve adhesion. It worked well for me on polyimide, PET and PEN.

Regards,

Francisco

Silane modification enhances the adhesion. For more details go to below link.

http://www.sciencedirect.com/science/article/pii/S0032386116301227

Thanks for you. Can I make plasma treatment after Au sputtering? or must i make plasma before