Improved electrical and reliability characteristics of hfn-hfo2-gated nMOSFET with 0.95-nm EOT fabricated using a gate-first process

Abstract

By using a high-temperature gate-first process, HfN-HfO2-gated nMOSFET with 0.95-nm equivalent oxide thickness (EOT) was fabricated. The excellent device characteristics such as the sub-l-nm EOT, high electron effective mobility (peak value ∼ 232 cm2/V. s) and robust electrical stability under a positive constant voltage stress were achieved. These improved device performances achieved in the sub-l-nm HfN-HfO2-gated nMOSFETs could be attributed to the low interfacial and bulk traps charge density of HfO2 layer due to the 950 °C high-temperature source/ drain activation annealing process after deposition of the HfN-HfO2 gate stack. © 2005 IEEE.