ON THE ENHANCEMENT OF EFFECTIVE BARRIER HEIGHT IN TI N-GAAS SCHOTTKY-BARRIER DIODES/

Changes in the Current-Voltage (I-V) and Current-Voltage-Temperature ( I-V-T) characteristics of Schottky Barrier Diodes (SBDs) on silicon do ped n-GaAs (Titanium/n-GaAs) after irradiation using protons at 100 ke V with various doses (5x10(13) to 1X10(15) cm(-2)) are presented and a nalysed. Irradiated SBDs reverse leakage current is more compared to t he unirradiated SBDs. Heavily irradiated (1X10(15) cm(-2)) SBDs almost behaves like an Ohmic contact at 360 K. The irradiated SBDs were anne aled at two different temperatures (200 and 350 degrees C for 15 min.) under nitrogen atmosphere and characterised using I-V and I-V-T measu rements. Rectifying behaviour of the irradiated SBDs improves as the a nnealing temperature increases. Enhancement of the effective barrier h eight (Phi(e)) and improvement in the ideality factor (n) has been obs erved in annealed (350 degrees C for 15 min) proton irradiated Ti/n-Ga As SBDs. This may be either due to hydrogen passivation of GaAs surfac e and/or removal of hydrogen related irradiation induced defects in SB Ds. On the unirradiated and annealed (upto 350 degrees C) there is no significant change in the characteristics as compared to the CONTROL S BDs.