M. Bishwadeep SAHA soutiendra sa thèse le 26 octobre 2021 à 13:30, sur le sujet suivant : "Investigation et Modélisation de la Haute Fréquence Effets dans les HBT SiGe" (Visioconférence totale : https://u-bordeaux-fr.zoom.us/j/84826880268).
Titre: Investigation and Modeling of High Frequency Effects in SiGe HBTs
To successfully address the growing demands of radio-frequency-based applications, rapid evaluation of the specific technology and intense device characterization and accurate modeling at the high-frequency regime are very important. These help the designers for further optimization and meeting the required standards. In this regard, we have addressed three aspects in this thesis. First, the measurement uncertainties involved with the determination of the maximum oscillation frequency (fMAX) in modern mm-wave transistors are discussed followed by a suitably proposed solution that allows us to obtain a fast evaluation of modern SiGe HBT technology. Secondly, the critical high frequency modeling challenges arising from the graded substrate doping in modern SiGe HBT technology is discussed followed by a pragmatic solution in the equivalent circuit model and subsequent formulations. Finally, the high-frequency behavior of a transistor fabricated in the 55-nm BiCMOS process is investigated. The crucial high-frequency effects such as the ones arising from vertical and lateral non-quasi static and dominating parasitic effects are analyzed, related parameters are extracted and subsequently the model is verified against calibrated TCAD simulation and measured data in a step-by-step manner.