RF reliability of gate last InGaAs nMOSFETs with high-k dielectric

A complete reliability study of the high-frequency characteristics for nMOSFETs on InGaAs channel with Al
₂
O
₃
/HfO
₂
gate dielectric is presented. DC gate voltage stress causes an increase in the transconductance frequency dispersion. Stress induced border traps degrade the maximum DC-transconductance, but do not react at high frequencies. The main degradation characteristics of the high-frequency measurements can be modeled by the threshold voltage related transconductance shift. The maximum of the cut-off frequency is shifted with stress to higher or lower gate biases, but not decreased.