TRANSISTORS, TRIODE, SILICON, PNP SWITCHNING

摘要

The design of the PNP silicon switching transistor is discussed in detail. Assuming the desired switching times of 10 and 15 nanoseconds for turn-on and turn-off respectively, the switching time constants are determined and shown to be obtainable by present techniques. Specifically, junction capacitances, CTC < 0.5 pf and CTE< 2.8 pf, will be met by shallow diffusions and small unit geometry. Col lector-base junction areas of 12 mils2 end 2 mils2 are discussed. The col lector-base breakdown voltage of 50 volts is based upon the resistivity and thickness of the epitaxial layer 1.4 -cm and 0.12 mils respectively. For an emitter-base breakdown voltage greater than 6 volts, a base surface concentration of 1018 atoms/cc is needed. These requirements place restrictions on the diffusion and contact techniques. . The low saturation voltage will be a compromise for low storage time.