ELECTRIC-FIELD BEHAVIOR AND CHARGE-DENSITY DISTRIBUTION IN SEMIINSULATING GALLIUM-ARSENIDE SCHOTTKY DIODES

The behavior of the electric field and the charge-density distribution in semi-insulating gallium arsenide Schottky diodes have been analyze d by optical-beam-induced current and surface potential;measurements. The electric field exhibits three different regions across the detecto r, the characteristics of which depend on the reverse applied voltage. Furthermore, a positive box-shaped space charge region exists, separa ted from the Schottky barrier by a neutral space-charge region, and wi dens and moves towards the Ohmic contact at increasing the reverse bia s voltage. This study adds substantial information to the knowledge of the space-charge distribution in semi-insulating Schottky diodes, dis criminates between the existing models on the electric field, and prov ides essential information to understand nuclear detector performance.