Impact of dipole-induced dielectric relaxation on high-frequency performance in La-incorporated HfSiON/metal gate nMOSFET

For the first time, the relationship between high frequency and dielectric relaxation of dipoles formed at the high-k/SiO 2 interface was systematically investigated in La-doped HfSiON devices. Due to the dipole-induced dielectric relaxation, it was found that high frequency performance, especially voltage gain degrades severely caused by a substantial loss in gate capacitance, transconductance, and output resistance in a frequency range below 1 GHz. Further study should be undertaken to improve the high frequency operation of La-doped high-k devices through fundamental understanding of the dipole-induced dielectric relaxation in the radio frequency (RF) regime.