화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.159, No.6, H589-H594, 2012
Structural and Electrical Characterization of Lu2O3 Dielectric Layer for High Performance Analog Metal-Insulator-Metal Capacitors
The structural and electrical properties of Lu2O3 dielectric films deposited by radio frequency (RF) magnetron sputtering on TaN electrode have been studied for metal-insulator-metal (MIM) capacitor in analog/RF applications. From X-ray diffraction study, it is observed that the deposited films remain amorphous within the thermal budget (400 degrees C) of back-end-of-line process. The root mean square value of surface roughness of the Lu2O3 film decreases after annealing at 400 degrees C using atomic force microscopy. The chemical composition of the Lu2O3 film was characterized by X-ray photoelectron spectroscopy. The MIM capacitor using a Lu2O3 dielectric film exhibited better electrical characteristics, such as a low leakage current of 5 x 10(-8) A/cm(2) at -1 V and a high capacitance density of 7.5 fF/mu m(2) with a low quadratic voltage coefficient of capacitance of 75 ppm/V-2. The current conduction mechanism was found to be dominated by Schottky emission mechanism in low electric field (< 1 MV/cm) region and hence further improvement in the leakage characteristics can be realized by employing a high work-function electrode or a large bandgap oxide as a barrier layer. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.086206jes] All rights reserved.