Impact of cerium oxide´s grain size for dielectric relaxation

Cerium oxide (CeO₂) thin films used liquid injection atomic layer deposition (ALD) for deposition and ALD procedures were run at substrate temperatures of 150 °C, 200 °C, 250 °C, 300 °C and 350 °C, respectively. CeO₂ were grown on n-Si(100) wafers. Variations in the grain sizes of the samples are governed by the deposition temperature and have been estimated using Scherrer analysis of the X-ray diffraction patterns. Strong frequency dispersion is found in the capacitance-voltage measurement. Normalized dielectric constant is quantitatively utilized to characterize the dielectric constant variation. The relationship extracted between grain size and dielectric relaxation for CeO₂ suggests that tuning properties for improved frequency dispersion can be achieved by controlling grain size, hence, the strain at the nanoscale dimensions.