Claims
- 1. In a process of growing single crystals by the double-layered CZ method in which the upper part of material in a crucible is heated to form a molten layer, and a solid layer is formed with its lower part, a seed crystal is made to contact a surface of said molten layer then pulled up to grow a crystal, which is characterized by applying a low magnetic field of between 100 Oe and 500 Oe to said molten layer to produce crystals of uniform oxygen concentration in the radial and crystal growing directions.
- 2. A process of growing crystals according to claim 1, in which variation in the temperature at the center of said molten layer is characteristically controlled to below 2.0.degree. C. per minute.
- 3. A process of growing crystals according to claim 1, which characteristically maintains the oxygen concentration below 10.times.10.sup.17 atoms/cm.sup.3.
- 4. A process of growing crystals according to claim 1, which characteristically controls the intensity of the magnetic field to the molten layer in the range of 100 Oe to 500 Oe, and maintains the oxygen concentration below 10.times.10.sup.17 atoms/cm.sup.3.
- 5. A process of growing crystals according to claim 1, wherein the crucible and seed crystal are rotated in opposite directions.
- 6. A process of growing crystals according to claim 1, wherein the crucible is rotated at speeds up to 15 rpm and the seed crystal is rotated in a direction opposite to that of the crucible.
- 7. A process of growing crystals according to claim 1, wherein the crucible and seed crystal are rotated in opposite directions and at different speeds of rotation.
- 8. A process of growing crystals according to claim 1, wherein during the crystal growing process the magnetic field is adjusted such that variation of temperature in the surface of the molten layer is controlled to provide a uniform radial distribution of oxygen.
- 9. A process of growing crystals according to claim 1, wherein during the crystal growing process a silicon single crystal is grown.
Priority Claims (1)
Number |
Date |
Country |
Kind |
6-063614 |
Mar 1994 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 08/413,617, filed Mar. 30, 1995 now abandoned.
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Continuations (1)
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Number |
Date |
Country |
Parent |
413617 |
Mar 1995 |
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