Plasticity of GaAs compliant substructures

Compliant substructures were fabricated by bonding two (0 0 1) GaAs wafers with an adequate twist angle. This induced a dense network of pure screw dislocations at the interface. The indentation plastic flow into such GaAs substructures was investigated and compared to the one obtained into bulk GaAs. We used a Berkovitch indentor that was loaded on the samples under forces ranging between 500 and 4500 μN. The loading and unloading curves as well as the plastic zone size were measured and compared to those measured on bulk GaAs under the same conditions. In view of their plastic behaviour, compliant substructures could be of great interest to improve the structural quality of the heteroepitaxial layers.