Low resistivity silicon carbide
An opaque, low resistivity silicon carbide and a method of making the opaque, low resistivity silicon carbide. The opaque, low resistivity silicon carbide is doped with a sufficient amount of nitrogen to provide the desired properties of the silicon carbide. The opaque, low resistivity silicon carbide is a free-standing bulk material that may be machined to form furniture used for holding semi-conductor wafers during processing of the wafers. The opaque, low resistivity silicon carbide is opaque at wavelengths of light where semi-conductor wafers are processed. Such opaqueness provides for improved semi-conductor wafer manufacturing. Edge rings fashioned from the opaque, low resistivity silicon carbide can be employed in RTP chambers.
1. A free-standing article of CVD silicon carbide comprising greater than 3×10 19 atoms of nitrogen/cm 3 and an electrical resistivity of less than 0.10 ohm-cm, the free standing article of CVD silicon carbide is made from precursors at temperatures from 1250° C. to 1400° C.
2. The article of claim 1 , wherein the CVD silicon carbide has from 5×10 19 to 1×10 20 nitrogen atoms/cm 3 .
3. The article of claim 1 , wherein the CVD silicon carbide has from 7×10 19 to 1×10 20 nitrogen atoms/cm 3 .
4. The article of claim 1 , wherein the CVD silicon carbide has an electrical resistivity of from 0.10 ohm-cm to 0.08 ohm-cm.
5. The article of claim 1 , wherein the CVD silicon carbide has an average electrical resistivity is from 0.02 ohm-cm to 0.06 ohm-cm.
6. The article of claim 1 , wherein the CVD silicon carbide is opaque to light at a wavelength of from 0.1 μm to 1.0 μm.
7. The article of claim 1 , wherein the CVD silicon carbide article is an edge ring, plasma screen or liner.
8. The article of claim 1 , wherein the CVD silicon carbide has an absorption coefficient of from 259 cm −1 to 1000 cm −1 .
9. The article of claim 1 , wherein the variation around the mean of the electrical resistivity is from 25% to 30%.
10. The article of claim 6 , wherein the article is opaque to the light temperatures of from 20° C. to 1475° C.