Impact of Forward Substrate Bias on Threshold Voltage Fluctuation in Metal–Oxide–Semiconductor Field-Effect Transistors

Abstract

The effect of forward substrate (body) bias on threshold voltage (Vth) fluctuation in metal–oxide–semiconductor field-effect transistors (MOSFET) and its device parameter [e.g., gate length, substrate impurity concentration, gate oxide thickness (effective oxide thickness), etc.] dependence are investigated using a charge-sharing model. It is predicted that, through the application of a forward substrate bias of 0.5 V, Vth fluctuation is suppressed by up to 20% and the device parameter sensitivity of Vth is reduced in sub-100-nm devices. An experimental result demonstrating the effect of forward substrate bias on Vth fluctuation suppression is also presented.