High purity SiOC and SiC, methods compositions and applications
Organosilicon chemistry, polymer derived ceramic materials, and methods. Such materials and methods for making polysilocarb (SiOC) and Silicon Carbide (SiC) materials having 3-nines, 4-nines, 6-nines and greater purity. Processes and articles utilizing such high purity SiOC and SiC.
1. A method of making an article comprising ultra pure silicon carbide, the method comprising:
a. combining a first liquid comprising silicon, carbon and oxygen with a second liquid comprising carbon;
b. curing the combination of the first and second liquids to provided a cured SiOC solid material, consisting essentially of silicon, carbon and oxygen;
c. heating the SiOC solid material in an inert atmosphere and at a temperature sufficient to convert SiOC to SiC, thereby converting the SiOC solid material to an ultra pure polymer derived SiC having a purity of at least 99.9999%; and,
d. forming a single crystal SiC structure by vapor deposition of the ultra pure polymer derived SiC; wherein the vapor deposed structure is defect free and has a purity of at least 99.9999%.
2. The method of claim 1 , wherein the ultra pure polymer derived SiC has excess carbon.
3. The method of claim 1 , wherein the ultra pure polymer derived SiC has no excess carbon.
4. The method of claim 1 , wherein the ultra pure polymer derived SiC is carbon starved.
5. The method of claim 1 , wherein the ultra pure polymer derived SiC has less than a total of 1 ppm of the impurities selected from the group of elements consisting of Al, Fe, B, P, Pt, Ca, Mg, Li, Na, Ni, V, Ti, Ce, Cr, S and As.
6. The method of claim 1 , wherein the combination of the first and the second liquids is a polysilocarb precursor formulation having a molar ratio of about 30% to 85% carbon, about 5% to 40% oxygen, and about 5% to 35% silicon.
7. The method of claim 1 , 5 or 6 , wherein the single crystal SiC structure is a boule.
8. The method of claim 1 , 5 or 6 , wherein the single crystal SiC is a layer.
9. The method of claim 1 , 5 or 6 wherein the single crystal SiC structure is a layer on a substrate.
10. The method of claim 1 , wherein the single crystal SiC structure is a layer on a substrate, wherein the substrate is comprised of Si.
11. The method of claim 1 , wherein the single crystal SiC structure is a layer on a substrate, wherein the substrate is comprised of SiC.
12. The method of claim 1 , 5 or 6 , wherein the single crystal SiC is sectioned and thereby manufactured into a wafer.
13. The method of claim 1 , 5 or 6 , wherein the single crystal SiC is sectioned and etched and thereby manufactured into a semiconductor.
14. The method of claim 1 , wherein the single crystal SiC is sectioned and etched and thereby manufactured into a metal-semiconductor field effect transistor (MESFET).
15. The method of claim 14 , wherein the MESFET is operably incorporated into a compound semiconductor device, whereby the MESFET is a component of the compound semiconductor device; the semiconductor device operating in the 45 GHz frequency range.
16. The method of claim 14 , wherein the MESFET is operably incorporated into a component of a cellular base station, whereby the MESFET is a component of the cellular base station.
17. The method of claim 16 , wherein the component is a power transformer.
18. A method of making an article comprising ultra pure silicon carbide, the method comprising:
a. combining a first liquid comprising silicon, carbon and oxygen with a second liquid comprising carbon;
b. curing the combination of the first and second liquids to provided a cured SiOC solid material, consisting essentially of silicon, carbon and oxygen;
c. heating the SiOC solid material in an inert atmosphere and at a temperature sufficient to convert SiOC to SiC, thereby converting the SiOC solid material to an ultra pure polymer derived SiC having a purity of at least 99.9999%; and,
d. forming a single crystal SiC structure by vapor deposition of the ultra pure polymer derived SiC; wherein the vapor deposed structure has a purity of at least 99.9999%; and wherein the single crystal SiC is a boule consisting essentially of alpha type SiC and is essentially free from micropipes.
19. The method of claim 1 , wherein the single crystal SiC is sectioned and thereby manufactured into a metal-semiconductor field effect transistor (MESFET); wherein the MESFET is a component of a power transformer.
20. The method of claim 1 , wherein the ultra pure polymer derived SiC has less than a total of 1 ppm of the impurities selected from the group of elements consisting of Al, Fe, B, and P.
21. The method of claim 1 , wherein the ultra pure polymer derived SiC has less than a total of 1 ppm of the impurities selected from the group of elements consisting of Al, Fe, B, P, Na and Ti.
22. A method of making a SiC, the method comprising:
a. placing polymer derived SiC particles in a vapor deposition apparatus, wherein the SiC particles have a purity of at least 99.9999%, and wherein the SiC particles have the ability to resist, and do not form an oxide layer when exposed to air under standard temperatures and pressures, whereby the SiC particles are free from an oxide layer; and,
b. directly vaporizing the SiC particles and depositing the vapors on a target to form crystalline SiC; wherein the vaporization occurs without the need for a preheating step of the SiC.
23. The method of claims 22 wherein he SiC crystal is a single crystal SiC boule.
24. The method of claims 22 wherein the SiC crystal is a single crystal SiC layer.
25. The method of claims 22 wherein the target is a substrate.
26. The method of claim 25 , wherein the substrate is comprised of Si.
27. The method of claim 25 , wherein the substrate is comprised of SiC.
28. The method of claims 22 , wherein the SiC crystal is sectioned and thereby manufactured into a wafer.
29. The method of claims 22 , wherein the SiC crystal is sectioned and thereby manufactured into a semiconductor.
30. The method of claim 22 , wherein the SiC crystal is a boule consisting essentially of alpha type SiC and is essentially free from micropipes.
31. The method of claim 22 , wherein the SiC crystal is sectioned and etched and thereby manufactured into a metal-semiconductor field effect transistor (MESFET).
32. The method of claim 31 , wherein the MESFET is operably incorporated into a compound semiconductor device, whereby the MESFET is a component of the compound semiconductor device; the semiconductor device operating in the 45 GHz frequency range.
33. The method of claim 31 , wherein the MESFET is operably incorporated into a component of a cellular base station, whereby the MESFET is a component of the cellular base station.
34. The method of claim 33 , wherein the component is a power transformer.
35. The method of claim 22 , wherein the single crystal SiC is sectioned and etched and thereby manufactured into a metal-semiconductor field effect transistor (MESFET); wherein the MESFET is a component of a power transformer.
36. A method of making ultra pure silicon carbide, the method comprising:
a. combining a first liquid comprising silicon, carbon and oxygen with, a second liquid comprising carbon;
b. curing the combination of the first and second liquids to provide a cured SiOC solid material, consisting essentially of silicon, carbon and oxygen; and,
c. heating the SiOC solid material in an inert atmosphere and at a temperature sufficient to convert SiOC to SiC, thereby converting the SiOC solid material to an ultra pure polymer derived SiC having less 99.9999% impurities.
37. The method of claim 36 , wherein the combination of the first and the second liquid is a polysilocarb precursor formulation having a molar ratio of about 30% to 85% carbon, about 5% to 40% oxygen, and about 5% to 35% silicon.
38. The method of claim 36 , wherein the temperature is above 1,200°C.
39. The method of claim 36 , wherein the temperature is from 1,200-2,500°C.
40. The method of claim 36 , wherein the temperature is from 1,600-1,900°C.
41. The method of claim 36 , wherein step c, comprises flowing an inert gas over the SiOC solid material during heating.