Electrical properties induced by oxygen vacancies of CeO2 thin films grown onp-Si(100)

We have deposited CeO₂ thin films on p-Si(100) substrates to investigate their electrical properties originated from oxygen vacancies, using pulsed laser deposition(PLD) method. (111) preferential orientation was observed. Raman spectra revealed that a film deposited at 760deg C had the smallest distortion of the unit structure due to small quantities of oxygen vacancy. X-ray specular reflectivities were measured to investigate an electron density profile along the thickness. The profile was strongly correlated with oxygen vacancy because total net charges inside the dielectric film should be zero. As a result, oxide trapped-charge density rho(x) could be extracted from the electron-density profile. C-V curves depending on frequencies showed that and interface trapped-charge density is not high. Flat band voltage in C-V curves was slightly shifted because of the presence of oxide trapped charge. We will report on a decisive method calculating the shift of flat band voltage.