Comparison of the "pad-open-short" and "open-short-load" deembedding techniques for accurate on-wafer RF characterization of high-quality passives

Abstract

The impedance errors remaining after applying the industry standard open-short, a pad-open-short, and a open-short-load deembedding scheme on a 0.43-nH 20-GHz high-Q single-loop inductor test structure are investigated using real S-parameter data taken up to 50 GHz. Since the latter two deembedding schemes both correct for all parasitic elements of the test structures, they are, at least in principle, error free. The accuracy of the open-short-load deembedding scheme, however, critically depends on how well the reactive part of the load resistance is accounted for. This issue makes the more simple pad-open-short deembedding scheme an attractive choice because the required split between external and internal capacitances is easy to make, either based on process and layout information or from measurements done on a pad dummy structure