Diffusion of Au in ZnSe and its dependence on crystal quality

Diffusion of gold in zinc selenide has been studied by using a C-12 and He- 4 ion backscattering technique. The samples were thin films grown by molecu lar beam epitaxy on bulk GaAs (100) substrates and on GaAs (100) epitaxial layers followed by evaporation of gold and annealing in the temperature ran ge 400-800 degrees C. The surface properties of the samples were studied wi th scanning electron microscopy and atomic force microscopy. The crystal qu ality of the samples was studied with He-4 ion channeling. The gold diffusi on was found to depend significantly on the crystal quality of the ZnSe. An empirical model for calculating the diffusion coefficient for different cr ystal quality ZnSe is presented. (C) 1999 American Institute of Physics. [S 0021-8979(99)06002-8].