Avalanche multiplication and breakdown in Ga/sub 0.52/In/sub 0.48/P diodes

The electron and hole photomultiplication characteristics M, and M/sub h/ have been measured in a series of Ga/sub 0.52/In/sub 0.4x/P devices with high field regions ranging from 2.0 /spl mu/m down to the depletion width of a heavily doped p-n junction. The hole ionization coefficient /spl beta/ is found to be slightly higher than the electron ionization coefficient /spl alpha/ at low fields but at high fields they approach one another. /spl alpha/ and /spl beta/ are found to be significantly lower than in GaAs across the entire range of electric fields studied, and the breakdown voltage of Ga/sub 0.52/In/sub 0.48/P is approximately 1.9 times higher than for similar GaAs structures. Contrary to the behavior observed in GaAs, the multiplication characteristics in all except the thinnest structures appear to be relatively unaffected by the dead space, the minimum distance required to gain sufficient energy to initiate impact ionization. In these very thin structures, a local description of multiplication cannot account for the ionization behavior accurately, and therefore, a Monte Carlo (MC) model has been used to reproduce the measured multiplication characteristics and extract the ionization coefficients.