Abstract :
In previous work dealing with arsenic emitters in bipolar transistors, no mention has been made regarding the (limiting) current gain mechanism in these devices. This paper presents data showing that the mechanism limiting gain in arsenic emitter structures is base region recombination, whereas for phosphorous emitter devices, emitter injection efficiency limits the gain. Moreover, the emitter efficiency increases as the concentration of arsenic in phosphorous-arsenic, mixed emitters increases. This variation of emitter efficiency in arsenic, phosphorous, and mixed arsenic-phosphorous emitters permits the fabrication of devices which have specialized emitter properties.
