A Parasitic Resistance Measurement Method Exploiting Gate Current-density Characteristics In Ultra-short Schottky-gate Fets

摘要

Gate forward current-density characteristics of ultra-short Schottky-gates are studied with experiments and calculation to clarify the mechanism of inhomogeneity in the current density along the gate length. Then, by exploiting the gate current-density characteristics, a new DC measurement method is proposed to evaluate the parasitic source and drain resistances, R_s and R_d, in the Schottky-gate FETs. The method is based on a gate-probing end-resistance technique, which can evaluate the values R_s and R_d simply and accurately by using DC measurement, even if the device has an ultra-short gate length L_g of less than 0.15 μm, because it applies a bias larger than a built-in voltage V_(bi), of the Schottky junction to the gate electrode in order to eliminate inhomogeneities in the gate current-density characteristics.