Anomalous Staircase CV Characteristics of InGaSb-on-Insulator FET

Quasi-static capacitance voltage (CV) characteristics of In
_1-x
GaxSb-on-insulator field-effect transistor (FET) are investigated using 1-D coupled Schrödinger-Poisson equations. Here, we report for the first time the staircase trend in the CV characteristics of such ultrathin-body FET. This observation is well correlated with the gate-bias-dependent electron concentration in different subbands. It is revealed that the staircase trend tends to disappear as the channel thickness increases above 15 nm. While the channel thickness and doping concentration-dependent shifts in CV curves are found to be significant, the composition-dependent shift is almost negligible.