Spectrophotometric and Raman spectroscopic characterization of ALD grown TiO2 thin films

Abstract

Properties of titanium dioxide thin films grown by atomic layer deposition from TiCl4 and H2O on SiO2 substrates were characterized using Raman spectroscopy and spectrophotometry methods. Raman spectroscopy revealed transformation of the film structure from amorphous to anatase, to anatase/rutile mixture and then back to anatase with the increase of deposition temperature from 100 to 680oC. Variations in the growth rate, refractive index and extinction index accompanied these structural changes. Analysis of the transmission curves demonstrated that differently from amorphous films, the crystalline films were optically inhomogeneous in the growth direction.