^ 



DESIGN THEORY OF JUNCTION TRANSISTORS 1295 



The physical parameters of interest are: 



Vc Collector voltage, —4.5 volts 



le Emitter current, 1 ma 



W'i Wafer thickness, 3.5 mils 



W2 Collector to surface thickness, 2.1 mils 



Wi Collector to emitter thickness (not including depletion layers), 

 3.6 X 10"' cm or 1.41 mil 



pt Base resistivity, 1.5 ohm cm 



Tb Hole lifetime in base region, 20 m sec 



pe, pc Emitter and Collector resistivities unknown but very low, prob- 

 ably 0.001 ohm cm 



Te, Tc Electron lifetime in emitter and collector unknown but very low, 

 probably 0.1 /x sec 



Ae Emitter area, 0.00114 cm^ 



Ac Collector area, 0.00456 cm^ 



The transmission parameters are then 



gee = 0.039 mho 

 To probably > 0.995 

 (3o = 0.993 

 a* c^ 1.0000 



I 



= 2.89 X 10"' cm/volt 

 A ^.o 



Qcc ^^8.15 nmhos 



The parameters which determine frequency response are: 



f ^ "^ = -^^ = — = 1.08 mcps 



•^" 27r irwl 7r(3.6 X 10-^)^ ^ 



Ct = 5,000 niifd/crn for collector 



so that 



Ct ^ 20,000 ^y,fd/cm for emitter 



Ctc = 22.8 fififd 

 Cre = 22.8 finfd 



