Understanding charge traps for optimizing Si-passivated Ge nMOSFETs

For the first time, two different types of electron traps are clearly identified in Ge nFETs with Type-A controlled by the HfO
2
layer thickness and Type-B by the Si growth induced Ge segregation. Only Type-B are responsible for mobility degradation and they do not saturate with stress time, while the opposite applies to Type A. A PBTI model is proposed and validated for the long term prediction.