An all-optical terahertz absorption technique for non-destructive characterization of nanometer-scale metal-oxide thin films grown on silicon substrates is described. Example measurements of laser and atomic layer-deposited films of HfO2, TiO3, Al2O3 and VOx as a function of deposition conditions and film thickness are described. This technique is found to be sensitive to HfO2 phonon modes in films with 5 nm nominal thickness.
Citation: Optics Letters
Issue: No. 9
Pub Type: Journals
nanometer films, metal oxides, terahertz, transmission spectroscopy, phonon modes, titanium oxide, hafnium oxide, far-infrared, morphology