Solvation effect of supercritical CO2 can be used to enhance the reaction rate and lower the activation energy barrier in many homogeneous reactions. However solvation effects in heterogeneous reactions, including thin film deposition have not been widely studied. We have recently studied the kinetics of organometallic pyrolysis in supercritical carbon dioxide to form a variety of metal oxide thin films (including Ga2O3, Al2O3, ZrO2, FeOx, Cr2O3, Co3O4, and WOx) to better understand the effects of solvation energy on the heterogeneous thin film deposition. For Al2O3 deposition from Al(acac)3, the deposition rate at 200°C is observed to be 10nm/min, compared to <1nm/min for typical vacuum based CVD from the same precursor. Similar results were observed for Ga2O3 thin film from Ga(acac)3. Moreover, an overall activation energy of 60-70 kJ/mol and 80-85 kJ/mol were observed for pyrolysis of Al(acac)3 and Ga(acac)3 in scCO2 phase, respectively, which are less than the typical values obtained in vacuum CVD. Solvation energy of stabilization of the reaction transition state is suggested as the main reason for the enhanced surface reaction rates. These results suggest that other heterogeneous reaction processes can also be enhanced by the solvation effects of scCO2. For example, reduced processing temperatures can extend inorganic thin film processing to temperature-sensitive organic and biomaterial substrates surfaces.