The effect of collector location on βuof I2L structures

I
²
L multicollector n-p-n transistor structures are used widely in LSI chips. Due to layout restrictions the collector could be at a distance from the injector. In this case, β
u
per collector is affected by the lateral voltage drop in the base. This effect becomes significant at higher current levels. In this work the lateral base region of the n-p-n transistor is modeled and a scheme is given to obtain the variation of β
u
with the base current. The results are compared to measurements obtained using a three-collector structure.