The current and capacitance characteristics as a function of sample temperature in YMn0.90Os0.10O3/p-Si structures

The I-V and C-V measurements have been performed on the Al/YMn0.90Os0.10O3 (YMOO)/p-Si/Al metal/ferroelectric material/semiconductor (MFES) structure at temperatures between 180 K and 320 K. YMOO thin film has been grown onto p-Si wafer by radio frequency (rf) magnetron sputtering technique using a polycrystalline YMOO single target. The surface roughness of the obtained YMOO thin film has been studied by atomic force microscope (AFM). Furthermore, the oxidation states of individual components, Y and O, have been investigated via X-ray photoelectron spectroscopy (XPS) analyses. A barrier height (BH) value of Phi(IV) = 0.89 eV for the Al/YMOO/p-Si structure has been subtracted from the I-V curves at 300 K. The obtained value of BH value is higher than the value of the conventional Al/p-Si diode, 0.58 eV. The linear relation of ln(I-F/V-F(2)) vs V-F(-1) plot has indicated that Fowler-Nordheim tunneling current affects through the interfacial layer at each temperature. The BH from C-D(-2) versus V-D curves has been obtained as Phi(CV) = 0.38 eV at 300 K and this value is lower than the value of Phi(IV) = 0.89 eV at 300 K eV. Such behavior is unexpected because the value of Phi(CV) is higher than that of Phi(IV) at the same temperature in the heterojunctions or metal-semiconductor contacts.