High-current-gain small-offset-voltage In/sub 0.49/Ga/sub 0.51/P/GaAs tunneling emitter bipolar transistors grown by gas source molecular beam epitaxy

Different emitter size, self-aligned In/sub 0.49/Ga/sub 0.51/P/GaAs tunneling emitter bipolar transistors (TEBTs) grown by gas source molecular beam epitaxy (GSMBE) with 100-AA barrier thickness and 1000-AA p/sup +/(1*10/sup 19/ cm/sup -3/) base have been fabricated and measured at room temperature. A small-signal current gain of 236 and a small common-emitter offset voltage of 40 mV were achieved without any grading. It is found that the emitter size effect on current gain was reduced by the use of a tunnel barrier. The current gain and the offset voltage obtained were the highest and lowest reported values to date, respectively, in InGaP/GaAs system heterojunction bipolar transistors (HBTs) or TEBTs with similar base dopings and thicknesses.<
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