Electrical Properties of CeO2 Thin Films Grown on p-Si(100) Substrates by the Pulsed Laser Deposition method

CeO2 thin films on p-Si(100) were deposited by using Pulsed Laser Deposition(PLD) to study the structure and the electrical properties. (111) preferential orientation was observed by the X-ray diffraction -2 scan method. FWHM was increased as the deposition temperature decreased. Also, they had a granular type of grain for very well oriented films deposited at 760 C in vacuum. To investigate electrical properties, an Au/CeO2/Si/Al structure was fabricated. C-V characteristic and I-V characteristic were produced with a HP4194 impedance-gain analyzer and a Keithlely 617 electrometer. A strong increase of capacitance appeared at relatively low frequency (100 kHz), which can be explained by a frequency-dependent non-uniformity state generated at the interface between CeO2 and Si substrate. Especially, based on each C-V characteristic, VF B(flat band voltage)was slightly shifted toward negative bias, which means that fixed oxide charge and interface trapped charge exist. In addition, slight hysteretic behaviors of the C-V curve attributed to trapping effects were observed at all measured frequencies. Current density of the film showed different tendencies for positive and negative bias. The difference of current density between negative and positive bias was over 10.6 order. We will report on these electrical properties and discuss various defect states that may dominantly affect the CeO2/Si system. KCI Citation Count: 4