Effect of number of sol-layer on structural, optical, morphological, and compositional properties of HfO2 films

Using sol-gel based spin coating HfO2 thin films were prepared on quartz substrates. The effect of sol-layer thickness on structural, optical, morphological and compositional properties was investigated. The structural studies done using X-Ray Diffraction (XRD) and Raman confirm the presence of a polycrystalline monoclinic phase of HfO2. Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM) studies reveal a uniform distribution of grains on the substrates. An increment in Hf is confirmed from Energy Dispersive Spectroscopy (EDS) with respect to the number of sol-layers. From XPS results existence of oxygen vacancies and the formation of HfO2 was noted. These results suggest that tailoring the number of sol-layers plays a crucial role in modifying the properties of HfO2 based thin films.