Slip band formation during bending of GaAs wafers

Abstract

Slip bands which appear after 4-point bending of liquid encapsulated Czochralski grown zinc doped GaAs (001) wafers at (412...447)°C have been characterized quantitatively both by reflection and transmission microscopy. Slip is initiated at the edges of the tensile part of the specimen. Deformation proceeds by the growth of slip bands in length through the whole specimen and in height up to « 200 nm. Their average distance goes down to « 20 μηι within the bending angle interval (0.2.. .5.9)° investigated. Residual stresses a t -σ 2 «(8...30) MPa have been detected by stressinduced birefringence measurements in the bent crystals.