Bulk and interface trap generation under negative bias temperature instability stress of p-channel metal-oxide-semiconductor field-effect transistors with nitrogen and silicon incorporated HfO2 gate dielectrics

Negative bias temperature instabilities (NBTIs) of p-channel metal-oxide-semiconductor field-effect-transistor with HfO2, HfOxNy, and HfSiON were investigated. Higher bulk trap generation (Delta N-ot) is mainly attributed to threshold voltage shift rather than interface trap generation (Delta N-it). Delta N-it, Delta N-ot, activation energy (E-a), and lifetime were exacerbated with incorporated nitrogen while improved with adding Si into gate dielectrics. Compared to HfO2, HfOxNy showed worse NBTI due to nitrogen pile-up at Si interface. However, adding Si into HfOxNy placed nitrogen peak profile away from Si/oxide interface and NBTI was reduced. This improvement is ascribed to reduced Delta N-ot and Delta N-it, resulting from less nitrogen at Si interface. (C) 2011 American Institute of Physics. [doi:10.1063/1.3541879]