Observation of current instabilities in a dielectric-surface-loaded ntype GaAs bulk element

Experiments were performed to investigate the effect of dielectric surface loading on GaAs bulk element. Current instabilities through the element were observed with a sampling oscilloscope while a dielectric sheet moved along a GaAs element. It was found that travelling-domain-mode current oscillations are suppressed and disappear only when the whole length of GaAs surface is covered with the dielectric sheet.