Removal of photoresist films along with underlying hexamethyldisilazane (HMDS) layers from SiO2 surfaces was studied using isopropanol (IPA) and IPA/NH4OH/H2O mixtures. Although IPA removed photoresist layers, pure IPA was unable to remove the HMDS layer, even at temperatures above 60 degreesC and pressures above 50 psi. Addition of NH4OH/H2O to IPA resulted in attack of the Si-O-Si bonds at the Si/HMDS interface. Residual carbon concentrations as low as 2.5 at. % on the posttreated surfaces were observed. IPA/NH4OH/H2O surfaces exhibited hydrophilic contact angles (15 degrees -20 degrees) indicating removal of both photoresist and the adhesion promoter layer from silicon dioxide surfaces. Atomic force microscopy analyses indicated no increase in the SiO2 surface root-mean-square roughness.