Hi,

Here is what I do on SiO2 coated Si wafers.
1- Treat in Piranha. 20% H2O2 and 50% H2SO4(@96%)
     The reaction is exothermic, wait for your solution to cool down before
taking your sample back.
2- Rince in DI water for about 1 to 2 min.
3- Back your sample on a hot plate at about 200° for at least 15-20 min
4- Allow to cool down before spinning your resin.

Good luck

Bruno