Physical identification of an excess base current component in silicided half-micrometer polysilicon-emitter bipolar transistors

The narrow emitter effect associated with the self-aligned silicidation of the emitter and base regions of an advanced single-polysilicon bipolar transistor structure is analysed. This effect is shown to arise from an increased electron recombination at the periphery of the emitter, due to the proximity of the silicided base contact to the emitter edge. The impact of this phenomenon on the scaling of the device to subhalf-micrometer dimensions is discussed.