Water is the best thing to dissolve PVA in for spin coating. A 2% solution should allow you to get the thickness you desire at around 4000 rpm.

I agree with the suggestion of Dr. Ron Reisrer

Water is the best solvent. Maybe you have figure out the viscosity a little bit, and try to deposit the film by spin casting onto the wafers. It will dry up quickly, and you mhave to take care about the wetttability of the substrate, and aim for a univofm coating, with no pinholes.

K. Sreenivas

Thanks a lot, everyone! I used DI water for the solvent of PVA solution. After preparing a 5% solution for spin coating, I obtained the thickness of PVA around 200 nm at 3000 rpm in 60 seconds.

Pham,

What MW of PVA did you use?

Thanks to you all for your contributions, this was indeed help.

Pham Xuan Thi you mentioned that for "5% solution of PVA in DI by spin coating, you got PVA thickness around 200 nm at 3000 rpm in 60 seconds " .

how do you avoid any pinholes or non-uniform surface. I want to deposit PVA thin film on glass substrate. what kind of surface treatment or cleaning should I do to get a good uniform film.

also did you use some oven heating or just let the film dry in room temperature.

Pham Xuan Thi do you have any publication on that