Transient Response of Charge Collection by Single Ion Strike in 4H-SiC MESFETs

The radiation damage of 4H-SiC Metal Semiconductor Field Effect Transistors (MESFETs) due to gamma rays was studied. The threshold voltage and Schottky property of gate contact varied only slightly after absorbed dose of 10.4 MGy(SiC). In addition, the transient response of charge collection was studied by using transient ion beam induced current (TIBIC) system. It was found that the collected charge was several orders of magnitudes higher than the charge induced in SiC by direct ionization. The most likely explanation of the enhanced charge collection was the bipolar and the channel modulation effects.