Producing high quality bulk silicon carbide single crystal by managing thermal stresses at a seed interface
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
C30B-023/06
C30B-029/36
C30B-023/00
C30B-033/00
H01L-021/324
출원번호
US-0249107
(2005-10-12)
등록번호
US-9200381
(2015-12-01)
발명자
/ 주소
Leonard, Robert Tyler
Powell, Adrian
Tsvetkov, Valeri F.
출원인 / 주소
Cree, Inc.
대리인 / 주소
Phillips, Steven B.
인용정보
피인용 횟수 :
0인용 특허 :
45
초록▼
A method is disclosed for producing a high quality bulk single crystal of silicon carbide in a seeded growth system by reducing the separation between a silicon carbide seed crystal and a seed holder until the conductive heat transfer between the seed crystal and the seed holder dominates the radiat
A method is disclosed for producing a high quality bulk single crystal of silicon carbide in a seeded growth system by reducing the separation between a silicon carbide seed crystal and a seed holder until the conductive heat transfer between the seed crystal and the seed holder dominates the radiative heat transfer between the seed crystal and the seed holder over substantially the entire seed crystal surface that is adjacent the seed holder.
대표청구항▼
1. A method of producing high quality silicon carbide single crystal using a seeded growth system, the method comprising: reducing the separation between a silicon carbide seed crystal and a seed holder until the conductive heat transfer between the seed crystal and the seed holder dominates the rad
1. A method of producing high quality silicon carbide single crystal using a seeded growth system, the method comprising: reducing the separation between a silicon carbide seed crystal and a seed holder until the conductive heat transfer between the seed crystal and the seed holder dominates the radiative heat transfer between the seed crystal and the seed holder over substantially the entire seed crystal surface that is adjacent the seed holder;initiating growth at substantially the same diameter as the seed crystal while minimizing torsional forces on the seed crystal;thereafter growing a bulk single crystal at substantially the same diameter as the seed crystal using a seeded sublimation technique while minimizing a concentration of dopants that contribute to conductive characteristics to produce an as-grown compensated crystal;later processing the as-grown compensated crystal by heating the as-grown compensated crystal to a temperature from 2000 degrees C. to 2400 degrees C. to increase point defects;subsequently cooling the as-grown compensated crystal at a rate from 30 degrees C. to 150 degrees C. per minute to avoid annealing the point defects back into the as-grown compensated crystal; andcutting a silicon carbide single crystal wafer from the as-grown compensated crystal, the silicon carbide single crystal wafer having a resistivity greater than 10,000 ohm-cm and a micropipe density less than 200 cm−2. 2. A method according to claim 1 comprising producing the as-grown compensated crystal using a seeded sublimation growth system. 3. A method according to claim 1 comprising initiating growth with a silicon carbide seed crystal that has a polytype selected from the group consisting of the 3C, 4H, 6H, and 15R polytypes. 4. A method of producing high quality silicon carbide single crystal using a seeded growth system, the method comprising: conforming the seed holder-facing surface of the seed crystal and the shape of the seed-holder to one another by preventing any gap between the seed and the seed-holder from exceeding 10 μm;initiating growth at substantially the same diameter as the seed crystal while minimizing torsional forces on the seed crystal;thereafter growing a bulk single crystal at substantially the same diameter as the seed crystal using a seeded sublimation technique while minimizing a concentration of dopants that contribute to conductive characteristics to produce an as-grown compensated crystal;later processing the as-grown compensated crystal by heating the as-grown compensated crystal to a temperature from 2000 degrees C. to 2400 degrees C. to increase point defects;subsequently cooling the as-grown compensated crystal at a rate from 30 degrees C. to 150 degrees C. per minute to avoid annealing the point defects back into the as-grown compensated crystal; andcutting a silicon carbide single crystal wafer from the as-grown compensated crystal, the silicon carbide single crystal wafer having a resistivity greater than 10,000 ohm-cm and a micropipe density less than 200 cm−2. 5. A method according to claim 4 comprising preventing any gap between the seed and the seed-holder from exceeding 5 μm. 6. A method according to claim 4 comprising preventing any gap between the seed and the seed-holder from exceeding 2 μm. 7. A method according to claim 4 comprising producing the as-grown compensated crystal using a seeded sublimation growth system. 8. A method according to claim 4 comprising initiating growth with a silicon carbide seed crystal that has a polytype selected from the group consisting of the 3C, 4H, 6H, and 15R polytypes. 9. A method according to claim 4 wherein the step of conforming the seed and the seed holder comprises preparing a seed crystal with the seed holder-facing surface that is flat within 10 μm. 10. A method according to claim 4 wherein the step of conforming the seed and the seed holder comprises preparing a seed crystal with the seed holder-facing surface that is flat within 5 μm. 11. A method according to claim 4 wherein the step of conforming the seed and the seed holder comprises preparing a seed crystal with the seed holder-facing surface that is flat within 2 μm. 12. A method according to claim 4 wherein the step of conforming the seed and the seed holder comprises preparing a seed holder with a seed-facing surface that is flat within 10 μm. 13. A method according to claim 4 wherein the step of conforming the seed and the seed holder comprises preparing a seed holder with a seed-facing surface that is flat within 5 μm. 14. A method according to claim 4 wherein the step of conforming the seed and the seed holder comprises preparing a seed holder with a seed-facing surface that is flat within 2 μm. 15. A method according to claim 4 comprising lapping a seed crystal that is at least 2 inches in diameter. 16. A method according to claim 4 comprising lapping a seed crystal that is at least 100 mm in diameter. 17. A method of producing high quality silicon carbide single crystal using a seeded growth system, the method comprising: lapping both sides of a seed crystal prior to seeded growth;initiating growth of a bulk single crystal on the seed crystal at substantially the same diameter as the seed crystal while minimizing torsional forces on the seed crystal;thereafter growing the bulk single crystal at substantially the same diameter as the seed crystal using a seeded sublimation technique while minimizing a concentration of dopants that contribute to conductive characteristics to produce an as-grown compensated crystal;later processing the as-grown compensated crystal by heating the as-grown compensated crystal to a temperature from 2000 degrees C. to 2400 degrees C. to increase point defects;subsequently cooling the as-grown compensated crystal to about room temperature in less than 70 minutes to avoid annealing the point defects back into the as-grown compensated crystal; andcutting a silicon carbide single crystal wafer from the as-grown compensated crystal, the silicon carbide single crystal wafer having a resistivity greater than 10,000 ohm-cm and a micropipe density less than 200 cm−2. 18. A method according to claim 17 comprising lapping both sides of the seed crystal to surfaces that are flat within 10 μm. 19. A method according to claim 17 comprising lapping both sides of the seed crystal to surfaces that are flat within 5 μm. 20. A method according to claim 17 comprising lapping both sides of the seed crystal to surfaces that are flat within 2 μm. 21. A method according to claim 17 comprising growing the as-grown compensated crystal in a seeded sublimation growth system. 22. A method according to claim 17 comprising: lapping the seed crystal using an abrasive slurry in conjunction with a hard surface to quickly remove a fairly large amount of material; and thereafter polishing the seed crystal to produce a finished surface. 23. A method according to claim 17 comprising initiating growth with a silicon carbide seed crystal that has a polytype selected from the group consisting of the 3C, 4H, 6H, and 15R polytypes. 24. A method of producing high quality silicon carbide single crystal using a seeded growth system, the method comprising: initiating growth of a bulk single crystal from a seed crystal at substantially the same diameter as the seed crystal while minimizing torsional forces on the seed crystal with a seed holder-facing surface that deviates from flat by no more than 10 microns;thereafter growing the bulk single crystal at substantially the same diameter as the seed crystal using a seeded sublimation technique while minimizing a concentration of dopants that contribute to conductive characteristics to produce an as-grown compensated crystal;later processing the as-grown compensated crystal by heating the as-grown compensated crystal to a temperature from 2000 degrees C. to 2400 degrees C. to increase point defects;subsequently cooling as-grown the compensated crystal to about room temperature in less than 70 minutes to avoid annealing the point defects back into the as-grown compensated crystal; andcutting a silicon carbide single crystal wafer from the as-grown compensated crystal, the silicon carbide single crystal wafer having a resistivity greater than 10,000 ohm-cm and a micropipe density less than 200 cm−2. 25. A method according to claim 24 comprising growing the bulk single crystal from a seed crystal with a seed holder-facing surface that deviates from flat by no more than 5 microns. 26. A method according to claim 24 comprising growing the bulk single crystal from a seed crystal with a seed holder-facing surface that deviates from flat by no more than 2 microns. 27. A method according to claim 24 comprising growing the bulk single crystal from a seed crystal with a seed holder-facing surface that deviates from flat by no more than 1 micron. 28. A method according to claim 24 comprising growing the as-grown compensated crystal using a seeded sublimation growth system. 29. A method according to claim 24 comprising initiating growth with a silicon carbide seed crystal that has a polytype selected from the group consisting of the 3C, 4H, 6H, and 15R polytypes. 30. A method of producing high quality silicon carbide single crystal using a seeded growth system, the method comprising: positioning a seed crystal for growth on a seed holder that deviates from flat by no more than 10 microns;initiating growth of a bulk single crystal on the seed crystal at substantially the same diameter as the seed crystal while minimizing torsional forces on the seed crystal;thereafter growing the bulk single crystal at substantially the same diameter as the seed crystal using a seeded sublimation technique while minimizing a concentration of dopants that contribute to conductive characteristics to produce a compensated crystal;cutting a silicon carbide substrate wafer from the compensated crystal;thereafter, heating the silicon carbide substrate wafer to a temperature from 2000 degrees C. to 2400 degrees C. to increase point defects; andsubsequently cooling the silicon carbide substrate wafer at a rate from 30 degrees C. to 150 degrees C. per minute to avoid annealing the point defects back into the as-grown compensated crystal and produce a silicon carbide single crystal wafer having a resistivity greater than 10,000 ohm-cm and a micropipe density less than 200 cm−2. 31. A method according to claim 30 comprising positioning the seed crystal for growth on a seed holder that deviates from flat by no more than 5 microns. 32. A method according to claim 30 comprising positioning the seed crystal for growth on a seed holder that deviates from flat by no more than 2 microns. 33. A method according to claim 30 comprising positioning the seed crystal for growth on a seed holder that deviates from flat by no more than 1 micron. 34. A method according to claim 30 comprising initiating growth with a silicon carbide seed crystal that has a polytype selected from the group consisting of the 3C, 4H, 6H, and 15R polytypes. 35. A sublimation growth method according to claim 30 comprising growing the compensated crystal using a seeded sublimation growth system. 36. The method of claim 1 wherein the silicon carbide single crystal wafer has a resistivity from 10,000 ohm-cm to 50,000 ohm-cm, and a micropipe density from 5 cm−2 to 200 cm−2. 37. The method of claim 4 wherein the silicon carbide single crystal wafer has a resistivity from 10,000 ohm-cm to 50,000 ohm-cm, and a micropipe density from 5 cm−2 to 200 cm−2. 38. The method of claim 17 wherein the silicon carbide single crystal wafer has a resistivity from 10,000 ohm-cm to 50,000 ohm-cm, and a micropipe density from 5 cm−2 to 200 cm−2. 39. The method of claim 24 wherein the silicon carbide single crystal wafer has a resistivity from 10,000 ohm-cm to 50,000 ohm-cm, and a micropipe density from 5 cm−2 to 200 cm−2. 40. The method of claim 30 wherein the silicon carbide single crystal wafer has a resistivity from 10,000 ohm-cm to 50,000 ohm-cm, and a micropipe density from 5 cm−2 to 200 cm−2.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (45)
Williams David M. (Oxon GB2), Amorphous silicon switch with forming current controlled by contact region.
Kong Hua-Shuang (Raleigh NC) Coleman Thomas G. (Durham NC) Carter ; Jr. Calvin H. (Cary NC), Apparatus for eliminating residual nitrogen contamination in epitaxial layers of silicon carbide and resulting product.
Barrett Donovan L. (Penn Hills Twp. PA) Hobgood Hudson M. (Murrysville PA) McHugh James P. (Wilkins Twp. PA) Hopkins Richard H. (Murrysville PA), High resistivity silicon carbide substrates for high power microwave devices.
Kondo, Hiroyuki; Oguri, Emi; Hirose, Fusao; Nakamura, Daisuke; Okamoto, Atsuto; Sugiyama, Naohiro, Method and apparatus for producing single crystal, substrate for growing single crystal and method for heating single crystal.
Johnson, Brian; Harrison, Ronnie M., Method and system for adjusting the timing offset between a clock signal and respective digital signals transmitted along with that clock signal, and memory device and computer system using same.
Ek Bruce Allen (Pelham Manor NY) Gates Stephen McConnell (Ossining NY) Guarin Fernando Jose (Millbrook NY) Iyer Subramanian Srikanteswara (Yorktown Heights NY) Powell Adrian Roger (Brookfield CT), Method for forming a single crystal semiconductor on a substrate.
Gunjishima,Itaru; Nakamura,Daisuke; Sugiyama,Naohiro; Hirose,Fusao, Method for manufacturing silicon carbide single crystal from dislocation control seed crystal.
Jenny, Jason Ronald; Malta, David Phillip; Hobgood, Hudson McDonald; Mueller, Stephan; Tsvetokov, Valeri F., Method for producing semi-insulating resistivity in high purity silicon carbide crystals.
Dmitriev Vladimir A. (Fuquay-Varina NC) Rendakova Svetlana V. (St. Petersburg RUX) Ivantsov Vladimir A. (St. Petersburg RUX) Carter ; Jr. Calvin H. (Cary NC), Method for reducing micropipe formation in the epitaxial growth of silicon carbide and resulting silicon carbide structu.
Jenny, Jason Ronald; Malta, David Phillip; Hobgood, Hudson McDonald; Mueller, Stephan Georg; Brady, Mark; Leonard, Robert Tyler; Powell, Adrian; Tsvetkov, Valerl F., One hundred millimeter high purity semi-insulating single crystal silicon carbide wafer.
Davis Robert F. (Raleigh NC) Carter ; Jr. Calvin H. (Raleigh NC) Hunter Charles E. (Durham NC), Sublimation of silicon carbide to produce large, device quality single crystals of silicon carbide.
Davis Robert F. (Raleigh NC) Carter ; Jr. Calvin H. (Raleigh NC) Hunter Charles E. (Durham NC), Sublimation of silicon carbide to produce large, device quality single crystals of silicon carbide.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.