Effect of ultrasound on the growth of semiconductor single crystals

The influence of ultrasound on striations in InSb, GaAs, and Bi-Sb single crystals grown by the modified Czochralski method was studied. Ultrasonic waves with a frequency ranging from 0.15 to 10 MHz were introduced into a melt parallel to the pulling direction. It was found that striations in single crystals pulled in the ultrasonic field are significantly reduced. GaAs layers were grown by modified liquid-phase epitaxy under the action of 3-MHz ultrasound. The effect of ultrasound on morphological changes during epitaxial growth was studied by in situ observation technique based on near-infrared microscopy. It was found that ultrasonic waves affect the growth of macroscopic steps. The effect of 1-MHz ultrasound on the convective flow and formation of standing waves in distilled water under different conditions (with the temperature gradient, disc-rotation speed, and fluid depth being varied) was studied using the light-cut technique.