D_(II) PL Intensity Dependence on Dose, Implantation Temperature and Implanted Species in 4H- and 6H-SiC

摘要

In most semi-conductor processing ion implantation is a key technology. The drawback of ion implantation is that a great deal of lattice defects, such as vacancies, interstitials, anti sites and complexes, are introduced. The annealing behaviour of these defects is important for the viability of ion implantation as a commonly used method. In SiC a defect that is only seen after ion implantation and not after irradiation with neutrons or electrons is the D_(II) defect. The use of Si or C as implanted species have made it possible to investigate the D_(II) photoluminescence (PL) intensity dependence on an excess of either of the two constituents in SiC. The effect of performing a hot implant at 600℃ compared to a room temperature implant was also looked into. The D_(II) PL intensity was measured after a 1500℃ anneal. When the implantation was performed at room temperature the C implanted samples showed a significantly higher D_(II) luminescence than the Si implanted. This makes it tempting to assume that a surplus of C and likely C interstitials are involved in the defect formation. However, when the implantation is done at 600℃ the difference between Si and C implanted samples almost disappears and a slightly higher D_(II) intensity can be seen in the Si implanted samples. This effect may be due to the mobility of C interstitials at temperatures above 500℃. This clearly demonstrates the effect of hot implantation that there is a major change in D_(II) PL intensity even after a 1500℃ anneal.