Atomic diffusion-induced deep levels near ZnSe/GaAs(100) interfaces

Abstract

Luminescence spectroscopy measurements of ZnSe/GaAs(100) heterojunctions grown by molecular beam epitaxy reveal the formation of deep levels near]] buried" interfaces upon thermal annealing. A pronounced emission at 1.9-2.0 eV appears at temperatures in the 300-400°C range depending on the ZnSe growth conditions with a constant activation energy of 1.10 eV. X-ray photoemission spectroscopy indicates a correlation between this deep level and atomic diffusion of Ga and Zn across the heterointerface. Zn-rich ZnSe growth conditions dramatically reduce this emission, highlighting the importance of local interface composition on thermal stability.© 1995 American Institute of Physics.