Formation of deep complexes in ZnSe during ohmic contact annealing

摘要

The formation of ohmic contacts tonhyphen;ZnSe grown by metalorganic vaporhyphen;phase epitaxy (MOVPE) on GaAs was investigated by currenthyphen;voltage and photoluminescence (PL) measurements. Annealing of the contacts even at temperatures as low as 300thinsp;deg;C causes the formation of deep complexes with PL emissions at 2.25ndash;2.35 and 1.97 eV. These centers degrade the electrical and optical properties of the ZnSe epitaxial layers. The effects of strain and Ga outdiffusion on ohmic contact properties was investigated in ZnSe layers of various thicknesses. Due to a galliumhyphen;doped ZnSe transition layer at the substrate heterointerface ohmic contacts are easily formed only on thin layers.