Abstract
In the fabrication of 4H-SiC junction barrier Schottky diode, p-type region was formed by ion implantation of Al. Two post-implantation treatments were adopted for activating the p-type dopant, (i) 1950 oC annealing for 10 min (Batch A); and (ii) 1700 oC for 40 min and gone through a sacrifice oxide process (Batch B). DLTS study revealed carbon vacancy (VC) with concentration of ~1015 cm-3 in Batch A samples, but no VC related signal was detected in Batch B, meaning that [VC] is lower than 1011 cm-3. The decrease of VC in Batch B sample is attributed to the lower annealing temperature and formation of sacrifice oxide layer on the surface. Most noticeably, the reverse leakage current in Batch B sample is much lower than Batch A over the whole range of reverse bias. This is due to the decrease of VC while the leakage current is dominated by Poole Frankel emission involving the carbon vacancy.
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