Experimental verification of the physics and structure of thebipolar junction transistor

The authors present an electrical characterization of discrete bipolar junction transistor (BJT) devices, with nonuniform doped emitter and base zones. The measurement of the I-V and C-V characteristics of the emitter-base and the collector-base junctions and the common emitter current gain allows to determine relevant parameters of the device. These are the built-in voltage of both junctions, the impurity gradient profiles, the electrical area of both junctions, the base and the emitter Gummel numbers and the collector doping. The whole experiment can be conducted in a laboratory session of 3-4 hour length and it is specifically addressed to students taking lectures in semiconductor device physics. The results obtained give a deep insight into both the physical structure and the physical processes involved in the transistor behavior     

DC characterization of fully ion-implanted p-n junctions intosemi-insulating InP

The forward and reverse characteristics of p⁺-n junctions made by Mg and Si implantation and rapid thermal annealing into Fe-doped semi-insulating InP are described. The effects of the Si dose for obtaining the n-type region, the use of P co-implantation for obtaining the p⁺ region, and the annealing time are studied. The dominant conduction mechanism at forward bias was found to be recombination in the space-charge region, with ideality factors of n=2 down to 198 K, and temperature dependence with an activation energy of 0.76 eV. The reverse characteristics presented junction breakdown at voltages around -20 V, and were accurately described by a thermally-activated trap-assisted tunneling mechanism. The energy of the corresponding trap, obtained by the fitting of the experimental characteristics, was 0.6 eV, and its origin was tentatively ascribed to the Fe deep acceptor present in semi-insulating InP