Physical and Electrical Analysis of Post- $\hbox {HfO}_{2}$ Fluorine Plasma Treatment for the Improvement of

Notable improvements in the HfO₂/In_0.53 Ga_0.47As gate stack have been achieved by a post- HfO₂ fluorine plasma treatment, including excellent interface quality of low equivalent oxide thickness HfO₂ (1.4 nm) directly on In_0.53Ga_0.47As without using an interface passivation layer, ~ 5× reduction in interface trap density from 2.8 ×10¹² to 4.9 ×10¹¹ cm^-2eV^-1, ~ 10× reduced border traps from 1.6 ×10¹⁹ to 1.6 ×10¹⁸ cm^-3, and ~ 40% less charge-trapping centers. As a result, improved electrical performances have been obtained. Frequency dispersion in capacitance-voltage characteristics has been reduced. Subthreshold swing has been improved from 127 to 109 mV/dec. Effective channel mobility has been enhanced from 826 to 1067 cm²/Vs. An improved drive current of 123 mA/mm at Vd = 2.5 V and Vg - V_th = 2 V (5- μm channel length) has been also presented.