Preparation and electrical characterization of CeO2 films for gate dielectrics application: Comparative study of chemical vapor deposition and atomic layer deposition processes

Abstract

We report on the preparation of CeO2 films by two different processes: chemical vapor deposition (CVD) by the thermal decomposition of Ce(Mp)4 and atomic layer deposition (ALD) by the hydrolysis of Ce(EtCp)3 and Ce(iPrCp)3. CVD at 350 °C produced polycrystalline cubic CeO2 films with good thickness uniformity. For both CVD and ALD processes, the metal-oxide-semiconductor (MOS) capacitors subjected to 500 °C annealing showed capacitance-voltage (C-V) characteristics with small hystereses (<1 mV) and flatband voltage shifts (<0:1 V). The frequency dispersion of the C-V curves, which is ascribed to the dielectric relaxation of CeO2, correlated with the crystallinities of the CVD and ALD films. © 2011 The Japan Society of Applied Physics.