Crater defects on the surfaces of epilayers, grown by molecular beam epitaxy, were investigated. A semi-empirical model, coupled with transmission electron microscopic observations, was used to analyze the defect formation mechanism. It was found that Te2 dissociation played an important role. The defect density could be controlled by adjusting growth conditions such as the substrate growth temperature, Hg flux, growth rate and composition. Close control of the pre-treatment before molecular beam epitaxial growth was also required.

Formation Mechanism of Crater Defects on HgCdTe/CdZnTe (211) B Epilayers Grown by Molecular Beam Epitaxy. Y.Chang, G.Badano, J.Zhao, C.H.Grein, S.Sivananthan, T.Aoki, D.J.Smith: Applied Physics Letters, 2003, 83[23], 4785-7