Physical and electrical characterization of high-k ZrO2 metal-insulator-metal capacitor

The effect of the deposition temp. and layer thickness on the phys. and elec. properties of ZrO2-based high-k metal-insulator-metal (MIM) capacitors was studied. The increasing thickness of ZrO2 layer leads to decrease of the leakage current and capacitance of the device. The microstructure investigation shows that after the deposition of the complete MIM stack layer, all samples reveal similar degree of crystallinity, independent of the dielec. deposition temp.; hence it cannot explain completely the different elec. performance of the device. We found that the concn. of impurities in the stack decreases as the deposition temp. increases. As a result, we obtain low leakage current (<10-8 A/cm2) with highest k value(.apprx.43) for 8 nm ZrO2 layer deposited at a temp. of 275 Deg.