Johansen, Tom; Krozer, Viktor (Oersted-DTU, Electro-Science Section Systems, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark)
Nodjiadjim, Virginie; Konczykowska, Agnieszka; Dupuy, Jean-Yves (Alcatel-Thales III-V Lab, F-91461 Marcoussis Cedex, France)
In this paper a novel extraction method for finding the extrinsic base resistance Rbx for InP DHBT devices is investigated. The method is based on the physical modeling of the intrinsic base-collector capacitance Cbci versus collector current Ic for InP DHBT devices when the collector is fully depleted. This makes it possible to determine Rbx as the extrapolated value of the effective base-resistance Rb,eff = R(Z11 - Z12) at the collector current Ic = Ip/(1 - X0) where Ip is a characteristic current and X0 is the base-collector capacitance splitting factor at zero collector current. The determination of the parameters Ip and X0 is described. The extraction method works well at lower collector current without the requirement on significant reduction of the intrinsic base-resistance due to current crowding.