FIELD: semiconductor devices. SUBSTANCE: measurement of profile of distribution of voltage drop in region of spatial charge of electrolytic barrier formed on surface of controlled layer of gallium arsenide is conducted with its located galvanostatic anodizing with exposure to pulse white light creating illumination intensity not less than 7000 lx in pulse. In this case voltage drop in region of spatial charge is found by value of jump of anode voltage occurring at moment of change of illumination intensity. Illumination intensity in the range from 600 to 2000 lx is established in time intervals between pulses. EFFECT: improved precision of determination of electrophysical parameters. 4 dwg
