Dual-transistor method to determine threshold-voltage shifts due to oxide-trapped charge and interface traps in metal-oxide-semiconductor devices

Abstract

A new technique is proposed to evaluate the radiation response of metal-oxide-semiconductor (MOS) transistors. The method requires that otherwise identical n- and p-channel transistors be irradiated under the same conditions. Using assumptions similar to those of widely accepted ‘‘single-transistor’’ methods, standard threshold-voltage and mobility measurements are combined to accurately estimate threshold-voltage shifts due to oxide-trapped charge and interface traps. This approach is verified for several MOS processes. The dual-transistor method can be applied to devices with much larger parasitic leakage, and at shorter times following a radiation pulse, than subthreshold current or charge-pumping techniques.