Electrical transport and trap properties in nitrogen-doped p-type MBE-grown ZnSe layers on GaAs using different contact materials

Electrical transport and trap properties were studied for nitrogen-doped p-type ZnSe layers grown on GaAs by molecular beam epitaxy (MBE). IV, CV and DLTS measurements were performed using gold, aluminium and indium dots as metal electrodes for the formation of Schottky contacts. In order to investigate the influence of thermal treatment on the defect properties of the ZnSe layers, the samples were annealed in vacuum at temperatures between 350 and 600 K. A strong hole-trap generation process is observable at temperatures higher than 500 K after annealing times exceeding 10 min. Moreover, annealing at 600 K leads to significant hole compensation caused by large trap concentrations generated at this temperature.