News Article
SiC growth breakthrough
Japanese researchers claim to have reduced the number of dislocations in silicon carbide crystals by two to three orders of magnitude (Nature, August 26, 2004).
Japanese researchers claim to have reduced the number of dislocations in silicon carbide crystals by two to three orders of magnitude (Nature, August 26, 2004). "These substrates will promote the development of high-power SiC devices and reduce energy losses of the resulting electrical systems," the scientists write. Other applications for SiC are seen as high frequency and high temperature.
A major problem with growing SiC crystals is that the material does not have a liquid form. Growth must be performed using gas phase methods on a seed crystal that can produce large numbers of inherited defects.
The Japanese solution gradually improves the quality of the seed in what they call "repeated a-face" (RAF) growth. In the SiC crystal structures there are two structurally equivalent "a-faces". Growth on one produces defects. However, if this is followed by growth on the other a-face, less defects are produced. Repeating the process produces seeds with less and less defects. In the final stage "c-face" growth is used to produce a SiC ingot.
