Avalanche multiplication in AlxGa1-xAs (x=0to0.60)

Electron and hole multiplication characteristics, M-e and M-h, have been me asured in AlinfinityGa1-infinityAs (x = 0-0.60) homojunction p(+)-i-n(+) di odes with i-region thicknesses, w, from I mu m to 0.025 mu m and analyzed u sing a Monte Carlo model (MC). The effect of the composition on both the ma croscopic multiplication characteristics and microscopic behavior is theref ore shown for the first time. Increasing the alloy fraction causes the mult iplication curves to be shifted to higher voltages such that the multiplica tion curves at any given thickness are practically parallel for different x . The M-e/M-h ratio also decreases as a: increases, varying from similar to 2 to similar to 1 as x increases from 0 to 0.60 in a w = 1 mu m p(+)-i-n(), The Monte-Carlo model is also used to extract ionization coefficients an d dead-space distances from the measured results which cover electric field ranges from similar to 250 kV/cm-1200 kV/cm in each composition. These par ameters can be used to calculate the nonlocal multiplication process by sol ving recurrence equations. Limitations to the applicability of field-depend ent ionization coefficients are shown to arise however when the electric-fi eld profile becomes highly nonuniform.