InP DHBT test structure optimization towards 110 GHz characterization

In this paper, three different designs of test structures are explored in order to accurately characterize InP DHBTs up to 110 GHz. In particular, a new design, optimized for high frequency measurements while keeping high device density, has been proposed. De-embedding test structures are analyzed and InP DHBT RF figures of merit are extracted for the three designs. Extraction of the maximum oscillation frequency, $f_{\text{MAX}}$ , confirms the relevance of optimized test structures as well as good performances of the new design.