Measurements of Alpha-Particle-Induced Charge in GaAs Devices

Results of charge collection measurements on GaAs devices bombarded with single alpha particles are presented. Experimental evidence is given which demonstrates that charge funneling and recombination play important roles in the charge collection process. The data are consistent with an average distance for prompt charge collection of nearly twice the equilibrium depletion region width. Comparison of the present results with existing charge funneling models is made and reasonable agreement is obtained. Comparing charge collection data for GaAs and Si devices indicates that they are comparable in their susceptibility to single-event upset caused by prompt charge. GaAs devices have a significant advantage in terms of total collected charge.