ABSTRACT
Electron and hole multiplication characteristics have been measured on a series of GaAs homojunction PIN diodes in which the nominal i-region thicknesses, w, range from 1μm to 25nm Using conventional analysis the effective electron and hole ionization coefficients, α and β respectively, have been deduced. Whereas the results calculated on the w = 1pm and 0.5μm structures agree with previously published data from measurements on thick devices, those observed in the thinner structures show device width dependence. By using a semi-analytical solution of Boltzmann's equation to interpret these results, dead space effects are seen to reduce α and β in short devices at low multiplication values but overshoot effects compensate when the electric field is increased.
