Subarray-SHORT De-Embedding for Improving Accuracy of On-Wafer Measurements of Devices for Millimeter and Submillimeter-Wave Applications

A de-embedding technique for high-Q or high-cutoff frequency ( $f_{{T}})$ one-port structures such as metal-oxide-semiconductor (MOS) varactors and Schottky diodes for millimeter- and submillimeter-wave applications is proposed to mitigate the limitation of vector network analyses of structures with a large ratio between the |reactance| and resistance (| X|/R). A subarray with a fewer number of cells of the device under test that has a lower | X|/R is used instead of an ultrahigh-Q OPEN structure for de-embedding. This technique provides more accurate measurements of cutoff frequency ( $f_{{T}})$ . The resulting average of %-variations of measured $f_{{T}}$ and series resistance over the measurement frequency range (50-55 GHz) are decreased by 30%-45%. More importantly, the %-variation range of $f_{{T}}$ for the proposed method over samples and frequencies is less than ~20% which is ~50% smaller than the de-embedding using a conventional ultrahigh-Q OPEN structure.