Temperature dependence of TaAlOx metal-insulator-metal capacitors

Structural and electrical properties of amorphous tantalum aluminum oxide (TaAlOx) films deposited using rf magnetron sputtering are investigated using metal-insulator-metal (MIM) capacitor structures with Au as metal electrodes. Crystallinity of the deposited films was studied using grazing incidence x-ray diffraction analysis. The frequency dependence of temperature coefficient of capacitance, an important parameter for precision MIM capacitors, is studied using the Au/TaAlOx/Au stacked layer. The effects of annealing temperature and the ambient on the physical and electrical properties of TaAlOx-based high-k MIM capacitors are reported. Low nonlinearity in capacitance values was found for samples annealed in O-2 ambient. Dielectric loss and permittivity are found to increase with increase in temperature. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3535558]