Small offset-voltage In/sub 0.49/Ga/sub 0.51/P/GaAs double-barrier bipolar transistor

In/sub 0.49/Ga/sub 0.51/P/GaAs double-barrier bipolar transistors (DBBTs) grown by gas-source molecular beam epitaxy (GSMBE) have been fabricated and measured. This structure has two InGaP barrier layers (100 AA in thickness): one is inserted between the emitter-base (e-b) junction and the other between the base-collector (b-c) junction. An offset voltage of 26 mV and a differential current gain of 120 at room temperature were obtained with a heavily doped p/sup +/ (2*10/sup 19/ cm/sup -3/) base (500 AA in thickness). The small offset voltage was attributed to the similar structure of the e-b and b-c junctions and to the suppression of the hole injection current into the collector by the InGaP hole barrier at the b-c junction.<
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