Impact of forming gas annealing on the degradation dynamics of Ge-based MOS stacks

Influence of forming gas annealing (FGA) on multi-layered G e based MOS capacitors is analyzed in terms of the C-V hysteresis and flat band voltage shifts for both negative and positive stress fields. It is found, that the FGA (H 2 /N 2 ) treatment does not affect the electron trapping observed at positive stress bias, while it reduces the positive charge trapping in high-K/G e stacks for stress at negative bias, which is a common trend regardless of the Al 2 O 3 /HfMOx stack. It indicates that a considerable part of the interface defects with energies close to the valence band existing in the oxide-semiconductor interface result passivated during the FGA. Furthermore, no time dependence is found for the stressing results.