Research of the contact pads topology influence on the parameters reproducibility of the current oscillations in mesa-planar structures based on semi-insulatinggallium arsenide

Experimental results of research the influence of the electric field distribution between the pads of mesa-planar resistor structures based on semi-insulating n-GaAs are represented. These influence by changing pads topology (plane-parallel, flat-pointed, counter-pointed and concave-pointed) was studied for the current oscillations parameters (the threshold voltage, frequency and amplitude of current oscillations) reproducibility increasing. It was found that the structures with counter-pointed topology metal sites improves the concentration of the electric field at the tip and a narrows the field of current flow, has a highest reproducibility of parameters such as the magnitude of the current oscillations occurrence threshold voltage and the amplitude of oscillation. For structures with a plane-parallel contact form reproducibility of experimental measurements is the smallest due to the high influence of edge effects.