Observation of Lattice Defects in 4H-SiC Power Devices by Grazing Incident Synchrotron Radiation Topography

Abstract

In order to observed inner structure of power devices made of 4H-SiC, a new method named grazing incident synchrotron radiation topography was developed. This method is very suitable for the observation without any disturbance by contrast of lattice defects inside 4H-SiC wafers. The purposes of development of this method is to improve reliability of power devices and their yield ratio. We could obtained new information by the observation of inner structure of power devices, as well as by investigate their electrical properties. On a way of this work, on the other hand, it was identified that dislocations show very characteristic contrasts, and there are some rules among contrast of dislocations, their Burgers vectors, type of dislocations and directions of dislocations. We have discussed the origin of the characteristic contrast using dynamical theory of X-ray diffraction.