Characterization of IrO2 thin films by Raman spectroscopy

Raman scattering has been used as a technique for characterization of the sputtered IrO2 thin films (SIROF) deposited on different substrates under various conditions. Compared with the spectrum of single crystal IrO2, red shift and broadening of the linewidth of the Raman peaks of SIROF are observed. X-ray diffraction measurements of SIROF were also carried out to assist the identification of the factor that influences the linewidth broadening of the Raman features. The results indicate that amorphous-crystalline transition for IrO2 phase can be achieved at substrate temperature of 200-300 degrees C. The line-shape and position of the Raman features vary for films deposited on different substrates under the same conditions. These differences can be due to the existence of stress between IrO2 and the substrates.