Epitaxy growth and electrical properties of La2Hf 2O7 thin film on Si(001) substrate by pulsed laser deposition

Abstract

La2Hf2O7 (LHO) thin films have been epitaxially grown on Si(001) substrates using an ultrahigh vacuum pulsed laser deposition (PLD) system. The high-resolution transmission electron microscopy (HRTEM) results show the predominant orientation of LHO grown on Si(001) is (001)LHO//(001)Si and [110]LHO//[110] Si, indicating a remarkable tendency of cube-on-cube epitaxy. The composition of the sample was investigated by X-ray photoelectric spectroscopy (XPS). High-frequency C-V characteristics for n-type MIS capacitors with epitaxial LHO film show that the dielectric constant (k value) of the LHO dielectrics is estimated approximately to be 22 from the accumulation area of 1M frequency C-V curves. I-V characteristic of the LHO dielectrics shows that the leakage current density is in an acceptable magnitude, ranging from 10 -7 to 10-2 A/cm2 in the voltage range from 0 to 3 V. © 2009 IOP Publishing Ltd.