300 GHz InP/GaAsSb/InP double HBTs with high current capability and BV/sub CEO/>6 V

Recent progress in compound semiconductor electron devices

“…Insertion of quaternary [11] or superlattice [12] layers between the base and collector is effective to obtain a smooth current flow. When GaAsSb is used as a base, the heterojunction with InP becomes a Type II or staggered junction, and smooth electron injection is obtained although the diffusion constant of GaAsSb is lower than that of InGaAs [13].…”

Self- and zinc diffusion in gallium antimonide

“…GHz have been reported [Dvorak, (2001)]. GaSb thermo-photovoltaic (TPV) devices are currently being sold as a means of generating power from a home furnace with 9 efficiencies approaching 11% by JX Crystals, Inc.…”

“…Results here can be compared and contrasted to results 1 in systems such as GaAs and even GaN, indicating trends within this common group of semiconductors. The results also have direct importance for ternary and quaternary semiconductor systems used in devices such as high speed InP/GaAsSb/InP double heterojunction bipolar transistors (DHBT) [Dvorak, (2001)]. …”

InP/GaAsSb/InP DHBTs with f T = 300 GHz and high maximum oscillation frequencies: the effect of scaling on device performance

“…So is then, in a nutshell, the general design philosophy behind the scaling of InP/GaAsSb/InP DHBTs. The results of Dvorak et al [3] proved difficult to improve upon with contact lithography, indicating nearly optimal process parameters were achieved for the involved electrode sizes. In order to overcome the performance limitations imposed by contact lithography, we have developed a new InP/GaAsSb/InP DHBT process relying on electron beam lithography for the emitter and base contact levels, in a mask set that also allows the fabrication of bigger all-optical devices on the same chip.…”

“…300 GHz devices have been demonstrated at SFU using optical hard contact lithography by Dvorak et al [3]. It is important to note that the InP/GaAsSb heterostructure system offers a number of important advantages for the realization of aggressively scaled DHBTs with cutoff frequencies well in excess of 300 GHz: i) extremely high C-doping levels can be achieved in GaAsSb base layers, with minimal H-passivation effects [4]; ii) GaAsSb base layers were shown to present an immunity to Auger recombination even at high doping levels [5]; iii) the low Fermi level pinning energy above the GaAsSb valence band edge enables the implementation of excellent base Ohmic contacts; and iv) the type-II band alignment at the base/collector junction ballistically launches electrons in the InP collector layer and achieves a higher average velocity for a given collector thickness W C [6].…”