On-Wafer Measurement of CPW with RDL Process for Substrate Effect in W-Band

This study aims to analyze the substrate effect of coplanar waveguide (CPW) with redistribution layer (RDL) process based on the On-Wafer measurement on the probe station chuck in w-band. The findings reveal that the substrate’s semiconductor properties and thickness can lead to the occurrence of an abrupt resonance cavity in transmission. Additionally, a novel equivalent circuit model is proposed to effectively describe the resonance cavity, with the frequency range from 110 MHz to 110 GHz. Moreover, the study demonstrates that utilizing On-Wafer measurement of CPW with absorbing material can effectively eliminate resonances, thus enhancing the accuracy of S-parameters measurement. This work can contribute to precise semiconductor device measurements in the millimeter-wave frequency range.