An Improved Through-Only De-Embedding Method for 110-GHz On-Wafer RF Device Characterization

In this letter, an improved through-only de-embedding method up to 110 GHz without additional dummy structure is developed and implemented. The highlight of this method is that the distributed effect of the metal interconnections between the pad and the intrinsic device is elaborately considered instead of simply modeled as a lumped constant circuit, and the optimal length of the transmission line is carefully derived. Based on this, the parasitics are removed by calculating the ABCD matrices. On-wafer RF passive devices, including T-coil and capacitor, are fabricated on 28-nm CMOS technology to verify the accuracy of the proposed method from 10 to 110 GHz. The measurement results after de-embedding by the proposed method are in good agreement with the electromagnetic simulation results of the intrinsic devices, which demonstrates that the proposed method has a better performance than conventional methods.