PLASTIC-DEFORMATION OF GAAS BY ULTRASONIC TREATMENT

For the first time we have obtained plastic deformation of A(III)B(V) semiconductors by ultrasonic treatment at high amplitudes. For temperatures above 520 K the plastic deformation of predeformed GaAs:Zn by ultrasonics has been detected by observing the multiplication and rearrangement of dislocations and also a sudden change of internal friction. From the sinusoidal distribution of vibration stress amplitude inside the sample it is possible to determine the stress at which the reorientation of predeformation-induced dislocatiins starts, as well as the stress at the beginning dislocation multiplication. Transmission electron microscopy investigations show a good agreement of the value of the stress where the multiplication by ultrasonic treatment begins with the yield stress obtained by uniaxial compression. However, the rearrangement of dislocations begins at lower stresses than that needed to reach multiplication.