Experimental model aid for planar design of transistor characteristics in integrated circuits

A two-transistor lumped model is used to describe the main features of transistors' two dimensional action. The model provides a first order correction to the ideal one dimensional transistor gain due to the effect of the emitter periphery. The correction is given in terms of a single parameter which can be experimentally evaluated for a fixed diffusion process. This makes the model a practical tool in I.C. transistor layout design. Experimental virification of the model is presented. Finally, implication to gain and cutoff frequency falloff due to lateral injection at high current is suggested.