To investigate the efficiency of hydrogen radical surface cleaning of patterned GaAs substrates, resonant tunneling devices have been fabricated in which the regrowth interface lies between the collector and the double barrier structure. Secondary-ion-mass spectroscopy data collected at the patterned substrate/regrown layer interface show a significant reduction of contaminant species after radical cleaning at similar to 450 degrees C for 2 h. The current-voltage characteristics of the resonant tunneling device further indicate a significant improvement in the quality of the regrowth interface in comparison to that achieved by standard thermal decontamination.