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

Abstract

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 DCtransconductance, 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.