How to cure diluted PDMS with solvent

I am doing some work with adding on a thin layer of PDMS that is diluted with a
solvent (DCM, THF, 1,4-Dioxane) on a silicon wafer by spin-coating or drop
coating. My problem is that I have noticed that I have bubbles on the backside
of the layer and I am having problem with curing it without getting bubbles. It
is either cavities of the solvent getting evaporated during curing or bubbles as
I might have to high temperature?
I usually cure at 100 deg. but I have also tried curing at boiling temperature
of the solvent and then later at 100 deg.
I usually have the ratio of 1:10 or 1:15 of the agent:elastomer. I add 1:6 ratio
of the PDMS:solvent. DCM has boiling point of 40 deg. and THF has a boiling
point of around 66 deg.
I am not sure what to do?
I need a thin (few micrometer) nice homogeneous layer (without cavities or
bubbles) that is molded into my structures of the wafer. My structures are in
the size of micrometers in size.
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