Effect of Millimeter-Wavelength Electromagnetic Waves on the Structure and Phase Composition of Gallium Arsenide Near-Surface Layers

Low-power microwave irradiation on the surface of gallium arsenide leads to the quantitative changes of the ratio of the Ga and As atoms (ions), which depends on the frequency of the electromagnetic field. It is shown that a variation in the Ga/As ratio results from the resonance relaxation processes caused by the drift of excess carriers and their lifetime, while the motion of charged particles takes place along an oscillating substrate and is determined by both drift and diffusion in the presence of the field of frequency-dependent electromechanical stresses. It is found that the effect leads to the changes of both composition and concentration and type of free carriers, which, in turn, causes changes in the rheological and electrical parameters of the surface, including variations in the direction and speed of charged particles accompanied by electronic and acoustic emission.