Modelling Considerations for Coupled Lines in CMOS Back-End-Of-Line at mm-Wave Frequencies

Abstract

We investigate the effect of passivation contouring, surface roughness, and sidewall tapering on the FEM modelling accuracy of mm-wave couplers in CMOS BEOL. Of three effects, sidewall tapering leads to the most significant improvement (0.37 dB) in predicting peak coupling magnitude at V-band. Ultimately, it is found that none of these measures substantially improve on modelling accuracy.