RF and DC Analysis of Stressed InGaAs MOSFETs

A complete reliability study of the DC and RF characteristics for InGaAs nMOSFETs with Al
₂
O
₃
/HfO
₂
dielectric is presented. The main stress variation at high frequencies is related to a threshold voltage shift, whereas no decrease is found in the maximum of the cutoff frequency and RF transconductance. Constant gate stress leads to a charge build up causing a threshold voltage shift. Furthermore, electron trapping at the drain side degrades the performance after hot carrier stress. The maximum DC transconductance is reduced following constant gate bias stress, by an increase in charge trapping at border defects. These border defects at the channel/high-κ interface are filled by cold carrier trapping when the transistor is turned on, whereas they do not respond at high frequencies.