A high-temperature H diffusion furnace was used for the investigation of the effect of H upon shallow dopants in 6H-material; as in the case of Si and GaAs. The acceptors and donors were monitored by means of their electron paramagnetic resonance signals. This high-temperature hydrogenation could neutralize both shallow acceptors and donors in 6H-SiC. This contrasted with what happened in Si, where the neutralization of shallow single donors seemed to be difficult to achieve by high-temperature H diffusion. However, it seemed to be easier fully to neutralize acceptors than donors in SiC. The present hydrogenation technique permitted H to be diffused over lengths which were of the order of 1mm. It was noted that progress in growth would have to be achieved before LVM spectroscopy of H-related complexes in 6H-SiC could be carried out.

B.Clerjaud, F.Gendron, C.Porte, W.Wilkening: Materials Science Forum, 1995, 196-201, 837-42