Narrow-Band-Gap-HBT Technology for Low-Power, High-Speed Applications

C. Monier, A. Cavus, R.s. Sandhu, M.D. Lange, P. Chen, B. Chan, D.J. Sawdai, P.C. Chang, V.F. Gambin, B. Oyama, T.R. Block, and A.L. Gutierrez-Aitken

Northrop Grumman Space Technology, Redondo Beach, CA  90278

e-mail:, Tel: (310) 812-6129


Keywords: HBT, InAlAl/InGaAs, metamorphic, high indium composition, low power



InxAl1-xAs/InxGa1-xAs heterojunction bipolar transistors (HBTs) with indium composition of 86% were grown on InP substrates using strain-relieved compositionally graded InxAl1-xAs buffers.  Lattice-matched In0.86Al0.14As/In0.86Ga0.14As single and double HBTs with small-emitter active areas have been fabricated on 6.0 A graded buffer layers.  Despite the use of this narrow-ban-gap material system, practical breakdown voltages approaching 4 V have been demonstrated from DHBT structures with high DC gain, limited leakage at the device junctions and turn-on voltage reduction by a factor of two compared to existing InP bipolar technology.  A peak cutoff frequency of 170 GHz has been measured from 6.0 A single HBTs with 1x5mm2 emitter size at very low collector-emitter voltage VCE of 0.55 V.  Initial test circuits including 28 GHz dividers that dissipate half the power of InP-based HBT circuits have been successfully demonstrated.


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