US3258314A - Method for interior zone melting of a crystalline rod - Google Patents

Method for interior zone melting of a crystalline rod Download PDF

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Publication number
US3258314A
US3258314A US272676A US27267663A US3258314A US 3258314 A US3258314 A US 3258314A US 272676 A US272676 A US 272676A US 27267663 A US27267663 A US 27267663A US 3258314 A US3258314 A US 3258314A
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United States
Prior art keywords
rod
zone
molten
melting
coil
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Expired - Lifetime
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US272676A
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English (en)
Inventor
John A Redmond
Jablonski Eugene
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Westinghouse Electric Corp
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Westinghouse Electric Corp
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Priority to US272676A priority Critical patent/US3258314A/en
Priority to BE646510A priority patent/BE646510A/xx
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Expired - Lifetime legal-status Critical Current

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    • 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
    • C30B13/06—Single-crystal growth by zone-melting; Refining by zone-melting the molten zone not extending over the whole cross-section
    • 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
    • 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
    • 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
    • Y10S65/00—Glass manufacturing
    • Y10S65/01—Lens envelope
    • 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
    • Y10S65/00—Glass manufacturing
    • Y10S65/04—Electric heat
    • 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
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T117/00—Single-crystal, oriented-crystal, and epitaxy growth processes; non-coating apparatus therefor
    • Y10T117/10—Apparatus
    • Y10T117/1024—Apparatus for crystallization from liquid or supercritical state
    • Y10T117/1076—Apparatus for crystallization from liquid or supercritical state having means for producing a moving solid-liquid-solid zone
    • Y10T117/1088—Apparatus for crystallization from liquid or supercritical state having means for producing a moving solid-liquid-solid zone including heating or cooling details

Definitions

  • the present invention relates to a method and apparatus for zone melting, and more particularly to a method and apparatus for crucible-free floating-zone melting of elongated material such as semiconductor material, refractory metal, etc. in rod-shaped form, according to which a longitudinal molten zone is caused to move axially along the material while it is held in a vertical attitude.
  • Various techniques are employed to obtain the molten state of the longitudinal zone of the rod material, such, for example, as by electron bombardment heating and induction heating.
  • the liquefied material of a throughmelted or floating molten zone between the adjacent upper and lower solid portions of the rod is believed to be retained between such portions primarily by surface tension, although in the case of heating by induction a levitating influence. from the magnetic field of the coil can be obtained from a specially-designed induction coil to contribute to confinement of such molten zone.
  • the practice has been to subject a selected lengthwise zone of the rod material to a single source of heat, such as a cathode coil for electron bombardment heating or an induction coil for induction heating, for a sufficient period of time to through-melt the rod.
  • a single source of heat such as a cathode coil for electron bombardment heating or an induction coil for induction heating
  • design and operating parameters are chosen to produce the molten zone in such previous fashion while causing such zone to scan the rod vertically upward by effecting relative axialwise movement between the rod and an encircling induction heating coil or an encircling electron bombardment heating coil
  • This practice is entirely satisfactory in many respects, but has resulted in limitation of the maximum diameter of rod which may be floating zone-melted without spill-over from the uniformly through-melted zone.
  • this maximum diameter with induction heating and levitating techniques appears to be 1% inches, and for tungsten rod, for another example, it appears to be considerably less.
  • a longitudinal zone of the invention includes the melting of the rod material internally by one heat source, while an outer solidified cup-shaped or bowl-shaped shell is maintained in the rod material in containment of a considerable portion of the inner molten material, and the melting of the rod externally by another heat source to give a complete through-melting only at the upper edge of the shell and at the top of the molten zone for a sufliciently narrow through-melted axial distance to maintain the molten material confined radialwise between the bottom of the upper solidified portion of the rod and the upper unmelted rim of the solidified shell.
  • the axial length of the floating or through-melted part of the molten zone may be kept sufiiciently narrow to assure containment of a larger diameter zone than heretofore possible and therefore a large diameter rod can be floating zone melted than heretofore.
  • the rod material is scanned by the molten zone as thus established, this scanning which per se forms no part of this invention, can be effected by any suitable means which obtains relative axialwise movement between the rod material and'the heat sources. Rotation of the rod also is desirable and can be obtained in well known manner.
  • FIGURE 1 illustrates in elevation, partly in outline and partly in section, the internal heating effect of a liquidcooled induction heating coil on a rod-shaped material when functioning in accord with a feature of the invention
  • FIGURE 2 illustrates the effect of melting the rod material internally with the liquid-cooled coil of FIGURE 1 at one power supply frequency, and melting through the outer periphery of the rod material by a second induction coil at a higher power supply frequency;
  • FIGURE 3 illustrates an alternate technique substituting electron bombardment heating in lieu of the externalheat induction coil of FIGURE 2;
  • FIGURE 4 illustrates another alternate arrangement for obtaining the external heating which employs a reflected radiation technique
  • FIGURE 5 is a cross-sectional view of a turn of a combined liquid-cooled coil and cooling gas coil.
  • the internal heating of the vertically-extending rod material is'accomplished by an encircling multi-turn water-cooled, hollow-tubing, induction coil 2 which is energized from an alternating current power supply- 3 by alternating current at a frequency and power level sufiicient to heat a longitudinal section or segment of the rod and cause an inner region 4 of the zone to melt while an outer encircling solid wall 6 remains unmelted by such coil by virtue of dissipation of heat therefrom, as by radiation to the cooled coil 2 and its environs.
  • a frequency of ten kilocycles per second, for example, at a power level of 40,000 watts with two-turn A x A" square section hollow copper coil cooled to F. will'internally melt a .675 diameter tungsten rod with a .040 inch approximately thick outer wall 6.
  • tungsten or other refractory metal similarly can be internally melted with suitable choice of frequency, power level, and coil temperature.
  • surface cooling of the silicon rod within such coil may be aided by directing a flow of gas over the outer surface of the rod material as by way of the interior of the coil 2 and orifices '7 at the inner periphery of the coil turns, as in FIGURE 2, 'where such cooling gas may also serve to cool the coil, or via a sepa rate gas manifold 8 formed separately or integrally with the coil 2 which may be separated by a partition 9 from an interior portion 10 of the coil through which cooling water is circulated in a well-known manner. Exemplified structural details of such a coil turn are shown in crosssection in FIGURE 5.
  • the zone melting method of the present invention will be carrried out in an enclosure which may be an evacuable one, a vacuum being necessary in the technique exemplified structurally in FIG- URE 3 employing electron bombardment, and which enclosure alternatively may contain various gases such as argon, helium, hydrogen, etc, in which case the gas for cooling the rod 1 as in FIG-URE 2 would be recoverable for recirculation following suitable cooling and treatment for removal of contaminants.
  • an enclosure which may be an evacuable one, a vacuum being necessary in the technique exemplified structurally in FIG- URE 3 employing electron bombardment, and which enclosure alternatively may contain various gases such as argon, helium, hydrogen, etc, in which case the gas for cooling the rod 1 as in FIG-URE 2 would be recoverable for recirculation following suitable cooling and treatment for removal of contaminants.
  • a method of floating-zone melting a rod-shaped material susceptible to floating-zone melting, in which the rod is vertically disposed and a molten zone is created in the rod and caused to move lengthwise therealong
  • the improvement for creating such molten zone comprising the steps of heating a longitudinal segment of the rod to obtain interior melting thereof while heat is dissipated from its outer surface to preserve an elongated solid outer shell in encirclement of the molten interior portion of the zone, and heating an axialwise narrow region of said shell at the upper portion of the molten zone to give through- -melting of the rod exclusively at such narrow region.
  • a method of floating-zone melting a rod of refractory metal material susceptible to floating-zone melting, in which the rod is vertically disposed and a molten zone is created in the rod and caused to move lengthwise therealong, the steps for creating such molten zone, inductively heating a longitudinal segment ofthe rod at a frequency and power level which causes melting of the interior thereof while dissipation of heat by radiation from the exterior preserves a solid outer wall which encircles the molten interior, such molten interior.
  • a method of floating-zone melting a floating-zonemeltable material in rod shape, in which the rod is vertically disposed and a molten zone is created in the rod and caused to move lengthwise therealong, the steps for forming the molten zone by penetratedly heating a longitudinal segment of the rod while providing for dissipation of heat from its outer surface, thereby creating an elongated interior of molten material encased in solid material, and surface heating of a narrow portion at the top of such molten interior to melt such encasing solid material and obtain through-melting of the molten zone exclusively at such narrow portion, such molten interior being of greater overall length than can be retained between adjacent upper and lower solid rod portions as a. floating zone through-melted for substantially the entirety of such length.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Furnace Details (AREA)
US272676A 1963-04-12 1963-04-12 Method for interior zone melting of a crystalline rod Expired - Lifetime US3258314A (en)

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BE646510A BE646510A (enrdf_load_stackoverflow) 1963-04-12 1964-04-13

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Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3351686A (en) * 1963-01-31 1967-11-07 Commissariat Energie Atomique Induction melting process of central core portion of cylindrical shaped refractory materials
US3362803A (en) * 1964-03-05 1968-01-09 Fed Republic Of Germany Method of making glass or ceramic covered wires
US3404966A (en) * 1964-09-04 1968-10-08 Northeru Electric Company Ltd Melting a ferrous ion containing ferrimagnetic oxide in a ferric ion crucible
US3423189A (en) * 1966-01-13 1969-01-21 Bell Telephone Labor Inc Zone melting
US3428437A (en) * 1964-07-16 1969-02-18 South African Iron & Steel Zone refining
US3445215A (en) * 1964-03-13 1969-05-20 Philips Corp Method for refining glass baths
US3607139A (en) * 1968-05-02 1971-09-21 Air Reduction Single crystal growth and diameter control by magnetic melt agitation
US3607115A (en) * 1969-10-29 1971-09-21 Gen Motors Corp Crystal pulling from molten melts including solute introduction means below the seed-melt interface
US3649210A (en) * 1965-07-10 1972-03-14 Siemens Ag Apparatus for crucible-free zone-melting of crystalline materials
US3876388A (en) * 1968-10-30 1975-04-08 Siemens Ag Method of varying the crystalline structure of or the concentration of impurities contained in a tubular starting crystal or both using diagonal zone melting
US3999950A (en) * 1971-01-07 1976-12-28 Siemens Aktiengesellschaft Apparatus for crystal growth in outer space
US4046617A (en) * 1975-09-05 1977-09-06 Nasa Method of crystallization
US4090055A (en) * 1977-02-10 1978-05-16 Northern Telecom Limited Apparatus for manufacturing an optical fibre with plasma activated deposition in a tube
US4199397A (en) * 1976-02-09 1980-04-22 Motorola, Inc. Spontaneous growth of large crystal semiconductor material by controlled melt perturbation
US5993540A (en) * 1995-06-16 1999-11-30 Optoscint, Inc. Continuous crystal plate growth process and apparatus
US6402840B1 (en) 1999-08-10 2002-06-11 Optoscint, Inc. Crystal growth employing embedded purification chamber
US6800137B2 (en) 1995-06-16 2004-10-05 Phoenix Scientific Corporation Binary and ternary crystal purification and growth method and apparatus
US20150203987A1 (en) * 2012-08-02 2015-07-23 Siltronic Ag Device for producing a monocrystal by crystallizing said monocrystal in a melting area
US10138573B2 (en) * 2013-04-25 2018-11-27 Zhejiang Jingsheng M & E Co., Ltd Auxiliary heating device for zone melting furnace and heat preservation method for single crystal rod thereof

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2538854B2 (de) * 1975-09-01 1979-02-15 Wacker-Chemitronic Gesellschaft Fuer Elektronik-Grundstoffe Mbh, 8263 Burghausen Einwindige Induktionsheizspule zum tiegelfreien Zonenschmelzen

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2686864A (en) * 1951-01-17 1954-08-17 Westinghouse Electric Corp Magnetic levitation and heating of conductive materials
US2743100A (en) * 1951-10-05 1956-04-24 Theodore Macklin Furnace for treatment of pulverized ores
US2839436A (en) * 1955-04-19 1958-06-17 Texas Instruments Inc Method and apparatus for growing semiconductor crystals
US2897329A (en) * 1957-09-23 1959-07-28 Sylvania Electric Prod Zone melting apparatus
US2956863A (en) * 1956-11-28 1960-10-18 Philips Corp Apparatus for the manufacture of single crystals
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
US3023091A (en) * 1959-03-02 1962-02-27 Raytheon Co Methods of heating and levitating molten material
US3121619A (en) * 1959-10-19 1964-02-18 Philips Corp Zone-melting method and apparatus

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2686864A (en) * 1951-01-17 1954-08-17 Westinghouse Electric Corp Magnetic levitation and heating of conductive materials
US2743100A (en) * 1951-10-05 1956-04-24 Theodore Macklin Furnace for treatment of pulverized ores
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
US2839436A (en) * 1955-04-19 1958-06-17 Texas Instruments Inc Method and apparatus for growing semiconductor crystals
US2956863A (en) * 1956-11-28 1960-10-18 Philips Corp Apparatus for the manufacture of single crystals
US2897329A (en) * 1957-09-23 1959-07-28 Sylvania Electric Prod Zone melting apparatus
US3023091A (en) * 1959-03-02 1962-02-27 Raytheon Co Methods of heating and levitating molten material
US3121619A (en) * 1959-10-19 1964-02-18 Philips Corp Zone-melting method and apparatus

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3351686A (en) * 1963-01-31 1967-11-07 Commissariat Energie Atomique Induction melting process of central core portion of cylindrical shaped refractory materials
US3362803A (en) * 1964-03-05 1968-01-09 Fed Republic Of Germany Method of making glass or ceramic covered wires
US3445215A (en) * 1964-03-13 1969-05-20 Philips Corp Method for refining glass baths
US3428437A (en) * 1964-07-16 1969-02-18 South African Iron & Steel Zone refining
US3404966A (en) * 1964-09-04 1968-10-08 Northeru Electric Company Ltd Melting a ferrous ion containing ferrimagnetic oxide in a ferric ion crucible
US3649210A (en) * 1965-07-10 1972-03-14 Siemens Ag Apparatus for crucible-free zone-melting of crystalline materials
US3423189A (en) * 1966-01-13 1969-01-21 Bell Telephone Labor Inc Zone melting
US3607139A (en) * 1968-05-02 1971-09-21 Air Reduction Single crystal growth and diameter control by magnetic melt agitation
US3876388A (en) * 1968-10-30 1975-04-08 Siemens Ag Method of varying the crystalline structure of or the concentration of impurities contained in a tubular starting crystal or both using diagonal zone melting
US3607115A (en) * 1969-10-29 1971-09-21 Gen Motors Corp Crystal pulling from molten melts including solute introduction means below the seed-melt interface
US3999950A (en) * 1971-01-07 1976-12-28 Siemens Aktiengesellschaft Apparatus for crystal growth in outer space
US4046617A (en) * 1975-09-05 1977-09-06 Nasa Method of crystallization
US4199397A (en) * 1976-02-09 1980-04-22 Motorola, Inc. Spontaneous growth of large crystal semiconductor material by controlled melt perturbation
US4090055A (en) * 1977-02-10 1978-05-16 Northern Telecom Limited Apparatus for manufacturing an optical fibre with plasma activated deposition in a tube
US5993540A (en) * 1995-06-16 1999-11-30 Optoscint, Inc. Continuous crystal plate growth process and apparatus
US6153011A (en) * 1995-06-16 2000-11-28 Optoscint, Inc. Continuous crystal plate growth process and apparatus
US6800137B2 (en) 1995-06-16 2004-10-05 Phoenix Scientific Corporation Binary and ternary crystal purification and growth method and apparatus
US6402840B1 (en) 1999-08-10 2002-06-11 Optoscint, Inc. Crystal growth employing embedded purification chamber
US20150203987A1 (en) * 2012-08-02 2015-07-23 Siltronic Ag Device for producing a monocrystal by crystallizing said monocrystal in a melting area
US9932690B2 (en) * 2012-08-02 2018-04-03 Siltronic Ag Device for producing a monocrystal by crystallizing said monocrystal in a melting area
US10138573B2 (en) * 2013-04-25 2018-11-27 Zhejiang Jingsheng M & E Co., Ltd Auxiliary heating device for zone melting furnace and heat preservation method for single crystal rod thereof

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Publication number Publication date
BE646510A (enrdf_load_stackoverflow) 1964-07-31

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