Performance of polysilicon gate HfO2 MOSFETs on (100) and (111) silicon substrates

Mobility dependence on Si substrate orientations was investigated for HfO2 MOSFETs for the first time. High-temperature (600 degreesC) forming gas (FG) annealing (HT-FGA) was applied on the devices on both (100) and (111) substrates to evaluate the mobility for optimal interfacial quality. Using HT-FGA, D-it of the (111) devices was reduced down below 1X10(12) cm(-2)V(-1). Similar to SiO2 devices, NMOS mobility of the (I 11) devices was lower than that of the (100) devices at higher effective fields, while it was reversed for PMOSFETs.