HfO_2 dielectrics engineering using low power SF_6 plasma on InP and ln_(0.53)Ga_(0.47)As metal-oxide-semiconductor field-effect-transistors

摘要

In this work, we demonstrate that device characteristics could be significantly improved by incorporating more fluorine (F) into HfO_2 dielectrics layer using low power SF_6 plasma treatment at different positions of gate oxide. Fluorine was incorporated in three ways: 4 min treatment from the top of 6 nm HfO_2, 4 min treatment in the middle of 6 nm HfO_2, or 2 min treatment each in the middle and from the top of HfO_2 layer. Drive current (I_d) and effective channel mobility could be improved by 70% and 51%, respectively, for devices with treatment both in the middle and from the top of HfO_2 high k layer compared to those of devices without SF_6 treatment. The impact of SF_6 plasma treatment on devices with HfO_2/In_(0.53)Ga_(0.47)As stack is also presented.