US3249406A - Necked float zone processing of silicon rod - Google Patents

Necked float zone processing of silicon rod Download PDF

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Publication number
US3249406A
US3249406A US250148A US25014863A US3249406A US 3249406 A US3249406 A US 3249406A US 250148 A US250148 A US 250148A US 25014863 A US25014863 A US 25014863A US 3249406 A US3249406 A US 3249406A
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United States
Prior art keywords
rod
coil
diameter
zone
rods
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Expired - Lifetime
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US250148A
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English (en)
Inventor
Lloyd R Crosby
Herbert M Stewart
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Dow Silicones Corp
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Dow Corning Corp
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Filing date
Publication date
Priority to NL126241D priority Critical patent/NL126241C/xx
Priority to NL302045D priority patent/NL302045A/xx
Priority to GB279/65A priority patent/GB1022790A/en
Priority to US250148A priority patent/US3249406A/en
Application filed by Dow Corning Corp filed Critical Dow Corning Corp
Priority to GB47918/63A priority patent/GB995399A/en
Priority to FR959588A priority patent/FR1394080A/fr
Priority to BE642180A priority patent/BE642180A/xx
Priority to DED43296A priority patent/DE1195420B/de
Priority to CH11064A priority patent/CH421911A/de
Application granted granted Critical
Publication of US3249406A publication Critical patent/US3249406A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B13/00—Single-crystal growth by zone-melting; Refining by zone-melting
    • C30B13/16—Heating of the molten zone
    • C30B13/20—Heating of the molten zone by induction, e.g. hot wire technique
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/22—Furnaces without an endless core
    • H05B6/30—Arrangements for remelting or zone melting
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S117/00—Single-crystal, oriented-crystal, and epitaxy growth processes; non-coating apparatus therefor
    • Y10S117/90—Apparatus characterized by composition or treatment thereof, e.g. surface finish, surface coating

Definitions

  • semiconductor materials such as SlllCOIl and germanium
  • electronic devices such as amplifiers
  • This molten zone is made to move from one end of the rod to the other one or more times, causing impurities in the rod to be driven ahead of the advancing molten zone and thus swept to the extremities of the rod.
  • the float zone method can be used for converting a rod of polycrystalline material to a single crystal, by seeding the molten zone at one end of the rod with a monocrystal which causes the remainder of the rod to be converted to monoc'rystalline form as the molten zone progresses along the length of the rod.
  • An alternative method of forming elongated rods of monocrystalline semiconductor material comprises introducing a monocrystalline seed into a pool of molten semiconductor material and withdrawing the seed from the surface of the pool at a slow controlled rate to cause the formation of a rod, as shown for example in U.S. Patent 2,631,356, issued March 17, 1953.
  • the present invention in its several aspects provides a method and improved apparatus for the production of high purity monocrystalline semiconductor rods and specifically, as a novel article of manufacture, a rod of high purity monocrystalline silicon having a diameter above about 1% inches.
  • the invention contemplates the use of an improved induction heating coil in a more or less conventional z-one drawing process, which may be further modified in accordance with another aspect of the invention to provide that the diameter of the rod formed in the operation is larger than the minimum opening of the coil through which the rod passes in the zone forming operation.
  • FIGURE 1 is an elevational view, in partial section, of apparatus suitable for carrying out the process of the invention
  • FIGURE 2 is a plan view of an improved induction heating coil having a central insert split ring for use in a float zone refining process such as that of FIGURE 1;
  • FIGURE 3 is a cross sectional view along the line 33 of FIGURE 2, representing a section through the split ring and one turn of the coil of FIGURE 1;
  • FIGURE 4 is an enlarged viewof a stage in one version of-the method of the invention showing the production of rod having a diameter larger than the minimum opening of the induction coil which is used;
  • FIGURE 5 illustrates another version of the process of the invention in which the rod produced again has a larger diameter than the minimum opening of the coil, but in which there is no overall enlargement of the rod.
  • FIGURE 1 there is depicted zone forming apparatus of a generally conventional type which is suitable for carrying out the process of the invention.
  • the apparatus of FIGURE 1 comprises a base plate 10 and a dome 11 which is hermetically sealed to the base plate 10 by means of gasket 12 and clamps 13 and 14. Dome 11 is provided with a window 15 for observation of the interior thereof. Conduit 16 leads from base plate 10 to a vacuum pump (not shown) for producing, if desired, a high vacuum within the system. Dome 11 is provided on its outer surface with cooling coil 17 through which a cooling fluid can be passed for preventing excessive temperature rise within the dome. Within the dome, uprights 18 and 19 support threaded spindles 21 a and 22 which are capable of being rotated by means of motors 23 and 25 through gears 26 and 27 respectively. Upright 18 carries slidable support 28 to which is attached upper rod holder 29 by means of arm 31.
  • Holder 29 engages the upper end of a rod 32 of semiconductor material to be processed, the lower end of which is secured in lower holder 33 which is rotatably carried by means of lower shaft 34 in base plate 10.
  • Lower shaft 34 like all other elements extending through base plate 10, is hermetically sealed by suitable means to permit establishment of a high vacuum within dome 11 if desired.
  • Support 28 carried on upright 18 is provided with an internally threaded bore which engages threaded spindle 21, rotation of which will cause support 28 to rise or descend as desired on upright 18.
  • Upright 1? supports slider 36 which is also provided with an internally threaded bore engaging spindle 22, rotation of which by means of motor 25 will cause the slider to rise or descend along upright 19.
  • coil 37 Attached to slider 36 is coil 37, a specific embodiment of which is shown in detail in FIG- URE 2. As shown in FIGURE 1, coil 37 encircles the rod of semiconductor material 32. Feeding the ends of coil 37 are conductors 38 and 39 which lead to a source (not shown) of high frequency current.
  • upper shaft 41 connected to upper rod holder 29, is provided with a spur gear 42 which can be driven by suitable means such as a motor (not shown) to cause rotation of the upper portion of the rod 32 above the molten zone in either direction.
  • lower shaft 34 connected to lower rod holder 33 can be rotated by means of gear and motor 24 in either direction.
  • relative rotation can be achieved by keeping one portion of the rod stationary and rotating the other portion or by rotating both portions of the rod in opposite directions. The latter is usually preferable since it causes the plane of shear to occur in the exact center of the molten zone, thus minimizing the tendency to cause dislocation of the relatively fluid molten material in the zone.
  • FIGURES 2 and 3 show in detail one embodiment of the improved induction heating coil of the invention.
  • the embodiment shown comprises a spirally wound planar coil 51 of an electrically conducting material, in this case formed of a hollow tube 52 of silver.
  • an electrically conducting material in this case formed of a hollow tube 52 of silver.
  • FIGURE 2 shows that in order to allow clearance for the return conductor 53 leading from the innermost turn of the coil, while still maintaining an approximately circular central opening, the turns of the coil are somewhat distorted on the left side thereof.
  • a substantially circular ring 54 of electrically conducting material electrically connected as by hard solder or braze 56 to the innermost turn of the coil unexpectedly improves the crystal structure of semiconductor rods processed with the induction coil in a float zoning operation.
  • the ring insert may be formed of any electrically conducting material which is suitable for the coil itself, such as silver and platinum. Certain conductors, such as gold and copper, tend to contaminate the rod, as will be apparent to those skilled in the art, and are therefore not preferred.
  • the insert ring 54 may have a height approximately equal to the diameter of the tube 52 of which the coil is formed, and a thickness somewhat less than its height. These dimensions are not critical, however, and are limited only by practical considerations of size, mechanical strength, etc.
  • Coil 51 is preferably made from a hollow conductor rather than solid wire, since this permits a cooling fluid to be passed through the coil if desired to prevent undesirably high temperatures from forming and further in view of the fact that the outer diameter of the tube need not be any larger than that of a solid conductor, since at the high frequency used in induction heating the interior of the conductor carries little if any current.
  • FIGURE 2 is planar in form, the invention is not limited thereto.
  • Central rings of the type shown can also be used in non-plan ar coils if desired, with the insert ring attached to the turn of the coil having the smallest diameter so that the ring itself makes the closest approach to a rod passing through the coil.
  • the ring insert In order to prevent shorting out the entire innermost turn of the coil (of FIGURE 2, for example) the ring insert cannot be complete, but must be rather split at one point, as by the air gap shown or by the inclusion of a small insulating section. This gap or insulating section must of course be in such position that it serves to insulate the innermost turn from that adjacent to it, as shown in FIGURE 2.
  • Slices from the rods were prepared for inspection under a microscope in the following manner: The surface of the slice to be examined was flooded with a mixture of 3 parts by weight nitric acid, reagent grade 2 parts acetic acid, reagent grade (99.7%), and 2 parts hydrofluoric acid, electronic grade (49%). The solution was left on the surface for 2 minutes to produce a mirror finish. The solution was then washed away with deionized water and the surface of the specimen was dried with methyl alcohol. The specimen was then etched by applying thereto a mixture of two parts :by Weight of a solution of 50 g. of chomium trioxide, reagent grade, in 100 ml. of deionized water and one part hydrofluoric acid, electronic grade (49%). The specimen was etched for from to 12 minutes at room temperature and then .flooded with deionized water to remove the etching solution and finally washed with methyl alcohol.
  • Another obstacle which has prevented the commercial production of fioat zoned rods larger than about 1 /3 inches in diameter is the fact that in these large sizes the surface tension of the material in the molten zone, which typically has a height equal to the diameter of the rod, is not suflicient to contain within the zone the relatively fluid molten material, which thus has a tendency to sag and drip. Still another obstacle stems from the fact that it becomes increasingly difficult to supply sufficient heat to obtain liquefaction of the material at the center of relatively large (over 1%; inch diameter) rods.
  • rods of 1% inch diameter could be obtained with difficulty only in the laboratory and not in commercial production, while float-zoned rods of 1 /2 inch diameter or more could not be made at all with the methods heretofore used.
  • crystalline rods of semiconductor material e.g., silicon
  • induction heating coil such as that of FIGURE 2
  • FIG- URES 4 and 5 The method can be carried out in one of two ways as depicted in FIG- URES 4 and 5.
  • the rod is caused to grow in diameter by pile zoning or squeeze zoning, i.e., feeding a relatively small rod through the central opening of the coil while bringing the ends of the rod toward each other, causing the thickness of the rod to increase.
  • the silicon In the vicinity of the coil the silicon is molten and as the rod is fed into the zone at a carefully adjusted rate, the molten material spreads below the coil to form a rod of a diameter larger than that of the original rod.
  • the rate at which the ends of the rod are fed toward each other relative to the rate of advancement in FIGURE 5 the diameter of the rod before and after processing is not changed by the fioat zoning treatment. During treatment, however, the rod is causedto pass through a coil having a diameter smaller than the initial (and final) diameter of the rod.
  • the rod is capable of going through a ring or coil having a smaller diameter than itself by reason of the fact that it is molten in the vicinity of the coil and is pinched to a narrow neck by the field created by the coil, as shown in FIGURE 5, as the ring travels in one direction or the other to sweep the entire length of the rod.
  • a further advantage of the use of a coil of such rela -tively small diameter under certain conditions is that rods produced in this manner show an unexpected improvement in radial resistivity of slices taken across the rod. Again, the explanation for the improvementobserved by using this technique is not definitely known. It can be theorized, however, that the closer coupling of the ring with the central portion of the formed rod creates a more uniform condition within the molten zone, which manifests itself in improved radial resistivity, such that the resistivity across a diameter of a slice taken from such a rod can be held to a variation from the maximum value of not more than 20%.
  • EXAMPLE 2 A silicon rod having an initial diameter of /8 inch was pileor squeeze-zoned in accordance with the method of FIGURE 4, using a coil with a ring insert having an inner diameter of 25 mm. to obtain a monocrystalline rod with a diameter of 1.67-1.69 inches. measurements were taken at 3 mm. intervals across the lower (seed) end and the top end of the crystal by means of a 4-probe method described by Valdes (Proceedings of the molten zone is obviously dependent on the relative I cross sectional areas of the rod before and after expansion and can be easily calculated on this basis.
  • the diameter of the rod at a given point remains constant before and after the molten zone has swept through that point.
  • the molten zone is caused to move upwardly at a convenient speed, say, 2 mm. per minute. It will be seen that if the portion of the rod above the molten zone is moved downwardly at the rate of 8 mm. per minute the diameter of the rod in the solidifying molten zone will increase to double that of the initial rod. This follows from the fact that the amount of material leaving the molten zone must be equal to that entering, since no accumulation occurs within the zone.
  • the measurements ranged from 10 1 to ohm centimeters, representing a variation of 12% of the maxi- I mum value, while at the seed end the figures ranged from 107 to ohm centimeters, representing a variation of 17%.
  • the oxygen content of this rod was less than 1 10 atoms per cc. of silicon.
  • Example 2 i.e., a monocrystalline silicon rod having a diameter over 1%; inches (1.65 inches in this case), having at the same time a variation of less than 20% in radial resistivity and an oxygen content of less than 1 1O oxygen atoms per cc. ofsilicon represents a novel product heretofore impossible to obtain.
  • monocrystalline rods of this diameter can be made by the Czochralski method, such rods invariably have oxygen contents at least twice as high (i.e., 2x10 atoms per cc. of silicon) and radial resistivities which vary by 40% or more across a diameter.
  • EXAMPLE 3 Twelve silicon rods were squeeze zoned from an original diameter of 22 mm. to a final diameter of 40 mm. (1.6 inches) using planar 4-turn coi-ls having an inside diameter of 25 mm. In six of the runs the coil contained an insert ring, while in the remaining six runs the insert ring was omitted.
  • the method of the invention involving enlarging the diameter of the rod is preferably carried out with a coil equipped with a central insert ring, it is not limited thereto. Even without such a ring insert, the method permits the commercial production of large diameter rods which meet commercial standards of quality, as shown in the following example.
  • EXAMPLE 4 A polycrystalline silicon rod having a diameter of 1 /2 inches (38 mm.) was successfully converted to a monocrystalline rod of the same diameter by float zoning, using a planar coil having an internal diameter of 29 mm.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Liquid Deposition Of Substances Of Which Semiconductor Devices Are Composed (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Manufacture And Refinement Of Metals (AREA)
US250148A 1963-01-08 1963-01-08 Necked float zone processing of silicon rod Expired - Lifetime US3249406A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
NL126241D NL126241C (xx) 1963-01-08
NL302045D NL302045A (xx) 1963-01-08
GB279/65A GB1022790A (en) 1963-01-08 1961-08-02 Improvements in or relating to the refining of semiconductor materials
US250148A US3249406A (en) 1963-01-08 1963-01-08 Necked float zone processing of silicon rod
GB47918/63A GB995399A (en) 1963-01-08 1963-12-04 Improvements in or relating to the refining of semiconductor materials
FR959588A FR1394080A (fr) 1963-01-08 1964-01-07 Procédé de raffinage par zone mobile d'une tige de matière semi-conductrice cristalline
BE642180A BE642180A (xx) 1963-01-08 1964-01-07
DED43296A DE1195420B (de) 1963-01-08 1964-01-07 Verfahren zur Schwemmzonenbehandlung eines Stabes aus kristallischem Halbleitermaterial
CH11064A CH421911A (de) 1963-01-08 1964-01-07 Verfahren zur tiegelfreien Schmelzzonenbehandlung eines Stabes aus kristallinem Halbleitermaterial, Induktionsheizspulenanordnung zur Durchführung des Verfahrens und nach diesem Verfahren hergestellter Siliciumstab

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Application Number Priority Date Filing Date Title
US250148A US3249406A (en) 1963-01-08 1963-01-08 Necked float zone processing of silicon rod

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BE (1) BE642180A (xx)
CH (1) CH421911A (xx)
DE (1) DE1195420B (xx)
GB (2) GB1022790A (xx)
NL (2) NL126241C (xx)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3424886A (en) * 1966-10-27 1969-01-28 Ajax Magnethermic Corp Induction heating
US3489875A (en) * 1966-10-27 1970-01-13 Ajax Magnethermic Corp Apparatus for induction heating of slabs
US3612806A (en) * 1970-02-26 1971-10-12 Park Ohio Industries Inc Inductor for internal heating
US3989468A (en) * 1973-11-22 1976-11-02 Siemens Aktiengesellschaft Apparatus for crucible-free zone melting of semiconductor crystal rods
US4045181A (en) * 1976-12-27 1977-08-30 Monsanto Company Apparatus for zone refining
USRE29824E (en) * 1973-11-22 1978-11-07 Siemens Aktiengesellschaft Apparatus for crucible-free zone melting of semiconductor crystal rods
US5902508A (en) * 1993-10-21 1999-05-11 Shin-Etsu Handotai Co., Ltd. Induction heating coil suitable for floating zone processing
US11725299B2 (en) 2020-07-28 2023-08-15 Novel Crystal Technology, Inc. Single crystal manufacturing apparatus and method

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1802524B1 (de) * 1968-10-11 1970-06-04 Siemens Ag Vorrichtung zum tiegelfreien Zonenschmelzen eines kristallinen Stabes,insbesondere Halbleiterstabes

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2481071A (en) * 1945-07-25 1949-09-06 Chrysler Corp High-frequency induction heating device
US2481008A (en) * 1945-06-27 1949-09-06 Induction Heating Corp Multiturn split inductor
US2485843A (en) * 1944-10-18 1949-10-25 Hartford Nat Bank & Trust Co High-frequency heating arrangement
US2825120A (en) * 1954-05-11 1958-03-04 Eastman Kodak Co Synthetic filament
US2972525A (en) * 1953-02-26 1961-02-21 Siemens Ag Crucible-free zone melting method and apparatus for producing and processing a rod-shaped body of crystalline substance, particularly semiconductor substance
US2990259A (en) * 1959-09-03 1961-06-27 Paul L Moody Syringe-type single-crystal furnace
US3002821A (en) * 1956-10-22 1961-10-03 Texas Instruments Inc Means for continuous fabrication of graded junction transistors
US3023091A (en) * 1959-03-02 1962-02-27 Raytheon Co Methods of heating and levitating molten material
US3038239A (en) * 1959-03-16 1962-06-12 Du Pont Crimpable composite filament
US3046100A (en) * 1958-01-20 1962-07-24 Du Pont Zone melting of semiconductive material
GB908370A (en) * 1959-05-29 1962-10-17 Siemens Ag A method of zone-melting a rod of crystalline material
US3065062A (en) * 1958-06-03 1962-11-20 Wacker Chemie Gmbh Process for purifying and recrystallizing metals, non-metals, their compounds or alloys
US3100250A (en) * 1961-04-07 1963-08-06 Herczog Andrew Zone melting apparatus

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1031893B (de) * 1952-08-01 1958-06-12 Standard Elektrik Ag Verfahren zur aeusseren Formgebung von Halbleiteranordnungen, insbesondere fuer Gleichrichter- und Verstaerkerzwecke mit Halbleitern aus Germanium oder Silizium
GB831305A (en) * 1955-01-11 1960-03-30 Ass Elect Ind Improvements relating to the refining of heavy metals by zone melting

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2485843A (en) * 1944-10-18 1949-10-25 Hartford Nat Bank & Trust Co High-frequency heating arrangement
US2481008A (en) * 1945-06-27 1949-09-06 Induction Heating Corp Multiturn split inductor
US2481071A (en) * 1945-07-25 1949-09-06 Chrysler Corp High-frequency induction heating device
US2972525A (en) * 1953-02-26 1961-02-21 Siemens Ag Crucible-free zone melting method and apparatus for producing and processing a rod-shaped body of crystalline substance, particularly semiconductor substance
US2825120A (en) * 1954-05-11 1958-03-04 Eastman Kodak Co Synthetic filament
US3002821A (en) * 1956-10-22 1961-10-03 Texas Instruments Inc Means for continuous fabrication of graded junction transistors
US3046100A (en) * 1958-01-20 1962-07-24 Du Pont Zone melting of semiconductive material
US3065062A (en) * 1958-06-03 1962-11-20 Wacker Chemie Gmbh Process for purifying and recrystallizing metals, non-metals, their compounds or alloys
US3023091A (en) * 1959-03-02 1962-02-27 Raytheon Co Methods of heating and levitating molten material
US3038239A (en) * 1959-03-16 1962-06-12 Du Pont Crimpable composite filament
GB908370A (en) * 1959-05-29 1962-10-17 Siemens Ag A method of zone-melting a rod of crystalline material
US2990259A (en) * 1959-09-03 1961-06-27 Paul L Moody Syringe-type single-crystal furnace
US3100250A (en) * 1961-04-07 1963-08-06 Herczog Andrew Zone melting apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3424886A (en) * 1966-10-27 1969-01-28 Ajax Magnethermic Corp Induction heating
US3489875A (en) * 1966-10-27 1970-01-13 Ajax Magnethermic Corp Apparatus for induction heating of slabs
US3612806A (en) * 1970-02-26 1971-10-12 Park Ohio Industries Inc Inductor for internal heating
US3989468A (en) * 1973-11-22 1976-11-02 Siemens Aktiengesellschaft Apparatus for crucible-free zone melting of semiconductor crystal rods
USRE29824E (en) * 1973-11-22 1978-11-07 Siemens Aktiengesellschaft Apparatus for crucible-free zone melting of semiconductor crystal rods
US4045181A (en) * 1976-12-27 1977-08-30 Monsanto Company Apparatus for zone refining
US5902508A (en) * 1993-10-21 1999-05-11 Shin-Etsu Handotai Co., Ltd. Induction heating coil suitable for floating zone processing
US11725299B2 (en) 2020-07-28 2023-08-15 Novel Crystal Technology, Inc. Single crystal manufacturing apparatus and method

Also Published As

Publication number Publication date
GB995399A (en) 1965-06-16
BE642180A (xx) 1964-07-17
DE1195420B (de) 1965-06-24
NL302045A (xx)
NL126241C (xx)
GB1022790A (en) 1966-03-16
CH421911A (de) 1966-10-15

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