STRUCTURE CHANGES IN GaAs CHIPS DEFORMED BY PRESSING AT 300 K

Abstract

Structure changes around an impress of indenter on GaAs singlecrystalswere investigated. Samples in the shape of rectangular parallelepipeds with the sizes 3 2.4 3.13.2 mm× × conterminous correspondingly to the crystallographic directions [011], [011] and [100 ] were used. The impresses were being put on side surfaces (011) and (011) with loads on indenter 0.20 N. Then the sample was subjected to pressing along the direction [100 ] (the greatest dimension) up to the stress σ = 83 MPa and was being maintained under the loading during 120 h at T = 300 K . After the removal of the loading two types of dislocations were revealed by chemical discriminating etching near the indenter impress. They were the prismatic loops, which have issued from the stress concentration area in the process of creeping, and dislocations sliding along the planes {111}. Running off of dislocations along the cleavage planes as a result of splitting off of the chip was observed.