A study of defects in LEC GaAs after copper diffusion

The defects present after the diffusion of copper at 770 degreesC in semiinsulating LEC GaAs have been studied by TEM, photoetching and atomic force microscopy. Clusters of microloops in the matrix and around the dislocations have been observed. The enhanced etching velocity in the surroundings of the dislocations suggests that they have gettered Cu. The relationship between such defects and gettering and the generation of non-equilibrium point defects associated with Cu diffusion and incorporation in the GaAs lattice is discussed.