Influence of Interface Trap States and Quantum Mechanical Effects on the Drain Current of III-V Semiconductor MOSFETs

Abstract

Effects of interface trap charges and quantum mechanical correction have been incorporated into the I-V characteristic of III-V semiconductor MOSFETs. MOS structures fabricated on III-V semiconductors are proving to be one of the most attractive replacements of currently used Si based MOSFETs. In0.53Ga0.47As channel transistors show immense potential in that field and hence used in this paper as the channel material of concern. An extracted version of density of interface trap states is used in order to make the analysis more practical. A physically based explicit analytical model for the QM correction has been used. Effects of interface trap states on the drain current have been included via a surface potential based analytical model. Degradation of mobility due interface charges is also considered. However influence of interface states due to variation of voltage across drain and source and existence of parasitic resistances and capacitances have been ignored. Analyzing I-V characteristics has given some staggering results where the drain current in saturation reduces to even 98.6% from the ideal condition. Subthreshold swing also showed some significant changes. Incorporating QM correction does not change the subthreshold swing much as expected but interface states drastically degrades the swing.