Electrical and physical properties of HfO2 as gate dielectrics using various thickness of TaN electrodes for MIS capacitors

Abstract

MIS capacitors with 16-nm high-k dielectric HfO2 and 50-150nm TaN electrode were studied after post-metal-annealing (PMA) at various conditions. The effect of TaN thickness on electrical and physical properties is summarized. It has been found that the thermal stability of the TaN/HfO2 depends on TaN thickness. A reduction of leakage current and an increase of breakdown voltage were obtained with 50-nm TaN after PMA at 500^oC. The interface quality and the time-dependent dielectric breakdown (TDDB) characteristics were also improved. On the other hand, degradation after PMA was observed in HfO2 capped with 100-nm and 150-nm TaN.