Effect of Mitridation on Al/HfO2/Ge MIS capacitors

MIS capacitors on nitrided and non-nitrided Ge substrates with HfO₂ as the dielectric have been studied. Effective oxide thickness is found to be reduced after nitridation. Significant improvements in the electrical characteristics are observed for the devices fabricated on nitrided substrates. The value of density of interface states is found to be lower for nitrided device when compared to non-nitrided device. Leakage current is drastically reduced for the nitrided device. The Breakdown field strength is improved from 11.3 MV/cm for the non-nitrided device to 15.89 MV/cm for the nitrided device.