Procedure to Determine and Correct for Transmission Line Resistances for Direct-Current, On-Wafer Measurements

Resistances of tenths of ohms to several ohms in transmission lines have been measured in laboratory systems from the power supply to the device under test (DUT). High-current semiconductor devices may draw currents of several amps. In cases such as these, the voltage drop in the transmission lines may rise up to several volts. In order to properly characterize the DUT, the losses in the transmission line and the voltage drop across the line must be measured and accounted for. A procedure for measuring the transmission line resistances is described. Once these values are known, it is necessary to apply a transform to the raw measured data in order to determine the actual voltages on the device of interest. A simple MATLAB code for determining the DUT current and voltage behavior is presented when the raw IV data and the transmission line resistances are known.