[mems-talk] Adhesion Mechanism between HMDS and PMMA

[CLAUDIO T MUNOZ]

Dear Members, 
In one of my  project I am characterizing PMMA films deposited on silicon substrate. To enhance adhesion I was told to use HMDS (hexamethyldisilozane). My question is: What is the chemical or physical interaction between the PMMA film  and the HMDS layer that makes the latter a good adhesion promoter for PMMA. Would PMMA films wet better over hydrophilic substrates as SiOx? I say this thinking on the possibility that PMMA could form strong hydrogen bonding with the SiOx substrate.
I am specifically concerned about the mechanism of adhesion between PMMA and HMDS. 
I believe some of our dear members might probably share some ideas to help me to understand my question. 
I will highly appreciate suggestions and comments
thanks
Claudio M
Chemical Engineering
University of Wisconsin-Madison