MOCVD-grown compressively strained C-doped InxGa1-xAs1-ySby with high-In/Sb content for very low turn-on-voltage InP-based DHBTs

We investigated metalorganic chemical vapor deposition of C-doped high-In-and-Sb-content compressively strained InxGa1-xAs1-ySby and examined InP-based heterojunction bipolar transistors (HBTs) with low base emitter turn on voltage. By lowering the growth temperature to 530 degrees C, the etching effect of CBr4 is suppressed, which is consistent with the results of thermodynamic calculations. We obtained high hole concentration of mid-10(19) cm(-3) with the In content of over 0.20. The base emitter voltage (V-BE) at collector current density (J(C)) of 10 nA/mu m(2) of large area HBTs with the high-In-and-Sb-content compressively strained InxGa1-xAs1-ySby base is lower than those of the HBTs with a tensile strained InxGa1-xAs1-ySby or GaAs1-ySby base, owing to the reduction of the band gap of the base layer. We fabricated InP/In0.20Ga0.80As0.55Sb0.45/InP HBTs with a 0.25-mu m-wide emitter and obtained the V-BE of 0.66 V at J(C) of 1 mA/mu m(2). At J(C)=13 mA/mu m(2), the device exhibits peak current gain cut off frequency of over 400 GHz, which is comparable to the value for GaAs1-ySby-base HBTs with the same base and collector thicknesses. (C) 2014 Elsevier B.V. All rights reserved.