Growth of RuO2 thin films on a MgO substrate by pulsed laser deposition method

RuO2 thin films have been grown on (100)MgO substrates by the pulsed laser deposition (PLD) method. X-ray diffraction (XRD) and Reflection high-energy electron diffraction (RHEED) measurements showed that the RuO2 thin film were (110) oriented and in-plane ordered (epitaxially grown). The electrical and optical properties of the RuO2 have been studied. Temperatures above 600 degrees C were required for growth of high quality films. When grown at 700 degrees C, the films exhibited resistivities as low as 39 mu Ohm.cm at room temperature. The real and imaginary parts of the dielectric constant and complex refractive index for RuO2 thin films were estimated in the photon energy range from 1.5 to 4.5 eV by spectroscopic ellipsometry measurements. A transition from the valence band to the conduction band was observed for RuO2 thin films near 2.7 eV and the dependence of the refractive index on the deposition temperature was also observed.