It is an object to provide a method for improving the quality of an SiC layer by effectively reducing or eliminating the carrier trapping centers by high temperature annealing and an SiC semiconductor device fabricated by the method.
A method for improving the quality of an SiC layer by eliminating or reducing some carrier trapping centers comprising the steps of:
(a) carrying out ion implantation of carbon atoms (C), silicon atoms, hydrogen atoms, or helium atoms into a shallow surface layer (A) of the starting SiC crystal layer (E) to introduce excess carbon interstitials into the implanted surface layer, and
(b) heating the layer for making the carbon interstitials (C) to diffuse out from the implanted surface layer (A) into a bulk layer (E) and for making the electrically active point defects in the bulk layer inactive. After the above steps, the surface layer (A) can be etched or mechanically removed. A semiconductor device according to the invention is fabricated by the method.