Commercially Available SiC

Here are some product specification sheets taken directly from major suppliers for the 4H-SiC polytype.

First, the 50.8 mm standard. Note that there is only one p-type wafer, that the resistivity is always very low or extremely large ("semi-insulating"), and that the "micropipe density" is a major parameter

Now the 50.8 mm standard. Note that there is only one p-type wafer, resistivities again are always very low or extremely large ("semi-insulating"), and there is no "ultra-low micropipe density" available in Sept. 2003.

The "Off-axis" specs together with the low resistivity in the "orientation" column tells us that these wafers are only intended as a substrates for an epitaxial layer.

Now the 6H-SiC wafers:

Note that there is a lightly p-doped (1 - 5) Wcm wafer.

No price quotes are given in the Internet. But SiC does not come cheaply. Prices of $250 - $500 (depending on specs) for one 50 mm wafer are presently (2003) asked. Anyway, there is progress: In 1995 it was more like $600 - $2000.

For that kind of money you get several 300 mm Si wafers, which are far more perfect form a crystal quality point of view. It follows that if people are willing to pay that much money for so little, SiC must be useful to some.

With frame

10.1.1 Silicon Carbide - Material Aspects