Emitter effects in shallow bipolar devices: Measurements and consequences

Measurements of minority-carrier lifetimes at silicon heavily doped with arsenic have been carried out using bipolar devices as vehicles. Auger and SRH mechanisms have been identified. Furthermore, bandgap-narrowing effects have been measured at the same material and found to be nearly as effective in n-type as in p-type material. Consequences of extreme miniaturization of bipolar devices concerning transistor performance, surface sensitivity and process control will be discussed based on the experimental results as well as on numerical calculations.