Electrical characterisation of high energy 12C irradiated Au/n-GaAs Schottky Barrier Diodes

Abstract

Au/n-GaAs Schottky Barrier Diodes (SBDs) have been fabricated on LEC grown silicon doped 〈1 0 0〉 GaAs single crystals. The SBDs were irradiated by 70 MeV high energy carbon ions with various ion fluences of 1 × 10 11, 1 × 10 12 and 1 × 10 13 ions cm −2. Current–voltage ( I– V) and capacitance–voltage ( C– V) characteristics of unirradiated and irradiated diodes were analysed. The change in reverse leakage current increases with increasing ion fluence. This is due to the irradiation induced defects at the interface and its increase with the fluence. The diodes were annealed at different temperatures (473, 573 and 673 K) to study the effect of annealing. The rectifying behavior of the irradiated SBDs improves as the annealing temperature increases. But at 673 K, the diode behavior has been deteriorated irrespective of the fluences. Better enhancement in barrier height and also improvement in the ideality factor has been observed at the annealing temperature of 573 K. A decrease in the capacitance has been observed with increasing fluence. For the irradiated and annealed SBDs, the increase in capacitance has been observed. Scanning Electron Microscopic analysis was carried on the irradiated samples to delineate the projected range and to observe defects induced by high energy carbon irradiation.