Abstract
Amorphous HfAlOx films deposited by RF magnetron co-sputtering of HfO2 and Al2O3 targets at a substrate temperature of 50 degrees C have been used for the fabrication of Metal-insulator-metal capacitor structures. Effects of different metal electrodes (Au and Al) are investigated and the electrical properties are compared. The electrical properties of the MIM capacitors are investigated by using current-voltage (I-V) and capacitance-voltage (C-V) characteristics in the 1 kHz-1 MHz frequency range. Using high work function (5.1 eV) top electrode Au, low leakage current and low energy dissipation is obtained in high density (similar to 5fF/mu m(2)) HfAlOx MIM capacitors with improved voltage coefficients of capacitance values. The leakage current density is approximately one order of magnitude higher than devices with Al electrodes. In addition, effects of constant voltage stressing and temperature on the leakage current and voltage linearity are also investigated. Stress voltage frequency dependence of quadratic voltage coefficient of capacitance is discussed.