InP/InGaAs/InP Double Heterojunction Bipolar Transistors with Improved DC and Microwave Performance Grown by Solid-Source Molecular Beam Epitaxy

摘要

This paper describes the fabrication and characterization of the InP/InGaAs/InP double heterojunction bipolar transistors (DHBTs) grown by solid-source molecular beam epitaxy (SSMBE). An improvement in current gain and microwave noise has been observed for the SSMBE-grown InP/InGaAs DHBTs. The HBT with a 50 nm, 2x19 cm~(-3) Be-doped base exhibits dc current gain as high as 350, which is about two times of that measured on the referenced devices grown by gas-source molecular beam epitaxy (GSMBE). The HBT with 5x5 μm~2 emitter shows a minimum noise figure (F_(min)) of 1.04 dB and associated gain (G_A) of 16 dB measured at 2 GHz with I_C=1 mA. In comparison, the HBT grown by GSMBE gives an F~(min) of 1.9 dB under same measurement condition. A slight increase in f_T and f_(max) for the SSMBE-grown HBT has also been observed. The drastic increase of current gain for the SSMBE-grown HBT could be explained by reducing base recombination due to the fall elimination of hydrogen contamination during the material growth.