This work demonstrates a novel method for deposition of metal oxide thin films, including Al 2 O 3 , ZrO 2 , MnO x , and RuO x where the metal-organic precursors and oxidizing agents are delivered in liquid and supercritical CO 2 . A cyclic deposition process is presented where reactants are introduced sequentially to control surface adsorption and byproduct removal steps. Reactions are studied in a hot wall reactor at pressures ranging from 1600 to 3600 psi at 80-200 °C, and X-ray photoelectron spectroscopy and infrared transmission confirmed metal oxide formation. We show that hydrogen peroxide is a viable O source for oxide deposition, whereas tert-butyl peracetate, which is a good electron acceptor, is less suited for oxygen donation. Capacitance versus voltage analysis of resulting Al 2 O 3 films show good dielectric properties after post-deposition anneal. We believe that the good solvation properties of supercritical CO 2 can aid in the delivery of precursors and in the removal of byproducts for advanced low-temperature processing of oxides and other materials of interest in electronic applications.

Fabrication for multilayered composite thin films by dual-channel vacuum arc deposition Rev. Sci. Instrum. 79, 065104 (2008); 10.1063/1.2937195 Reduction of thin oxidized copper films using a hot-filament hydrogen radical source J. Vac. Sci. Technol. A 25, 415 (2007); 10.1116/1.2712197 Damascene Cu electrodeposition on metal organic chemical vapor deposition-grown Ru thin film barrier