EVIDENCE OF ZERO POTENTIAL SPIKE ENERGY IN ALGAAS GAAS HETEROSTRUCTURE EMITTER BIPOLAR-TRANSISTORS

The potential spike energy at the emitter junction of AlGaAs/GaAs hete rostructure emitter bipolar transistors (HEBT) was directly measured f or the first time. Experimental data revealed that emitter thickness a s thin as 300 angstrom is thick enough to eliminate potential spike wi thout compositional grading. It is found that the band bending in n-Ga As reduces the potential spike and hence very low offset voltage of 70 mV with high current gain of 150 can be obtained.