Investigation of InP/InGaAs superlattice-emitter resonant tunneling bipolar transistors (RTBTs)

An InP/InGaAs superlattice-emitter resonant tunneling bipolar transistor (S E-RTBT) has been fabricated and demonstrated. The influence of the superlat tice and emitter thickness on the device characteristics is studied. The in sertion of the superlattice and a well-designed emitter improve the charact eristics of the SE-RTBT. Common-emitter current gains up to 170 and 54 are obtained for the studied devices with emitter thicknesses of 800 Angstrom a nd 150 Angstrom, respectively. Based on the specified structure, the lower offset voltage and saturation voltage (less than or equal to1.5 V) are obta ined. Experimentally, the device with a 5-period superlattice and an emitte r thickness of 800 Angstrom provides higher dc performance and stable tempe rature-dependent characteristics. (C) 2001 Academic Press.