US3271115A - Apparatus for crucible-free zone melting of semiconductor material - Google Patents

Apparatus for crucible-free zone melting of semiconductor material Download PDF

Info

Publication number
US3271115A
US3271115A US469048A US46904865A US3271115A US 3271115 A US3271115 A US 3271115A US 469048 A US469048 A US 469048A US 46904865 A US46904865 A US 46904865A US 3271115 A US3271115 A US 3271115A
Authority
US
United States
Prior art keywords
rod
coil
melting
semiconductor
zone
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US469048A
Other languages
English (en)
Inventor
Keller Wolfgang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens Schuckertwerke AG
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Application granted granted Critical
Publication of US3271115A publication Critical patent/US3271115A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • 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
    • 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
    • C30B13/28—Controlling or regulating
    • 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
    • Y10S117/911—Seed or rod holders
    • 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
    • Y10T117/1016—Apparatus with means for treating single-crystal [e.g., heat treating]
    • 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
    • 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 apparatus constructed in accordance with my invention is of the type which employs a vertically mounted rod-shaped semiconductor element and an induction heating coil displaceable along the axis of the rod for producing a melting zone, as vwell as a subsidiary induction heating coil for preheating or after-heating the solid semiconductor material.
  • An apparatus of the aforementioned type is described, for example, in the German patent DAS 1,007,885.
  • a disadvantage of the known apparatuses of this type is that during the relative displacement of the melting coil and the semiconductor rod that is rigidly clamped at both ends, the end clamps of the semiconductor rod cannot be moved up to the melting coil, but only to the preheating and after-heating coils. In this way the entire clamped length of the semiconductor rod cannot be subjected to the zone melting but only a relatively short portion thereof. This results in an uneconomical use of the zone-melting equipment as Well as of the semiconductor rod that is being processed.
  • I provide in an apparatus for crucible-free zone melting of a rod-shaped semiconductor member, a subsidiary induction heating coil having longitudinally extending turns, portions of which are substantially parallel to one another.
  • the subsidiary induction heating coil is located in such a position that these portions of the turns extend in a direction parallel to the axis of the rod-shaped semiconductor member.
  • the portions of the coil turns arranged substantially parallel to one another are located in the peripheral surface of an imaginary cylinder and respectively alternately connected with one another at the ends of the imaginary cylindrical surface so that a meandering or sinuous conductive line is formed.
  • FIGS. 1 and la are perspective views of two different embodiments of the zone-melting apparatus of my invention.
  • FIG. 2 is a transverse sectional View of the embodiment of FIG. 1a taken at a location above the heating coil 5.
  • FIG. 1 of the drawing there is shown a semiconductor rod 2 clamped at both ends in two clamping holders 3 and 4.
  • the semiconductor rod ends are set into two ceramic tubes 3a and 4a which are in turn securely held in both clamping holders by suitably tightening the associated set-screws.
  • the semiconductor rod 2 is heated by a single turn induction heating coil 5 that is connected to an electric power source (not shown) which produces a melting zone 6.
  • an additional or subsidiary induction heating coil 7 which has an elongated shape and which consists of coil turn portions that extend parallel to one another.
  • the induction coil 7 is disposed in such a manner that the longitudinal axis of the semiconductor rod 2 lies parallel to the turn portions, so that the heating effect of the coil 7 extends over substantially the entire length of the semiconductor rod.
  • the metal components of the clamping holders 3 and 4 such as the set-screws, for example, are suitably located beyond the heating effect of the coil 7.
  • One of the rod clamping holders can be made rotatable in a manner well known in the art. Relative movement between the semiconductor rod 2 and the melting coil 5 occurs, for example, by displacing the rod clamping holders 3, 4 while the coils 5 and 7 are held stationary. It is, however, preferable that the semiconductor rod be held stationary by its clamping holders and only the melting coil 5 be displaced vertically as shown in the figure. In such a case the subsidiary heating coil 7 can also be fixed with respect to the semiconductor rod, which provides a further advantage of the apparatus constructed in accordance with my invention in that only one relatively small component of the apparatus, namely the melting coil 5, has to be moved. All of the components of the apparatus can be compactly installed in a vacuum chamber. The apparatus of my invention can, however, also be operated under protective gas.
  • the induction coil 7 for preheating the semiconductor rod can for example be 30 centimeters long and as shown in the drawing can consist of two windings or turns. The portions of the windings extending parallel to each other are spaced apart a distance of 70 millimeters for example.
  • a supplied heating capacity of about 2 to 3 kilowatts is suificient for heating a silicon rod of about 25 mm. diameter with a specific resistance of about 1,000 ohm centimeters to 1100 to 1200 C. Radiant heating can be provided in a known manner for preheating the silicon rod until the current absorption through induction becomes possible.
  • the induction coil for melting the semiconductor rod 2 can be constructed, for example, as a flat coil with two windings. A power input of 2 to 3 kilowatts is sufficient for melting the aforementioned V silicon rod. Naturally the melting coil can also be in the form of a cylindrical coil having a different number of windings.
  • Supplemental heating with the additional induction coil 7 for a zone-melting process in which numerous passes of the melting zone are made, is carried out only during the final zone pass, as it has been experimentally determined that the vquality of the crystal, for monoc'rystalline growth, for example, depends essentially only on the last zone pass.
  • the semiconductor rod should be severed for example by smelting in the vicinity of the upper clamping location. Then the power to the melting coil 5 should be switched off and thereafter the heat output of the induction coil 7 reduced gradually, for example, over an interval of about 20 minutes, by continuously turning the lower rod-clamping holder 4 and the rod, accordingly, until the silicon rod is cooled from a temperature of about 1100 to 1200 C. to a temperature of about 600 C. Then the power to the induction coil 7 should be switched off.
  • FIGS. la and 2 there is shown a semiconductor rod 12 clamped at opposite ends by a pair of clamping holders 13, 14 and heated, for example, by a spirally wound fiat coil 15 to produce a melting zone therein.
  • the heating coil 15 for producing the melting zone can also be a cylindrical coil.
  • the winding portions of another coil 16 extend parallel to the axis of the semiconductor rod 12.
  • the coil 16 is Wound in such a manner that winding portions thereof extend both parallel to one another and to the rod axis. These portions of the windings are disposed on the peripheral surface of an imaginary cylinder whose axis passes through the rod or is coextensive With the rod axis.
  • the parallel portions of the windings are respectively alternately connected to one another at the upper and lower ends thereof, as shown in FIG. 1a.
  • the conductor or conductive line consequently has a meandering or sinuous form so that the current fiow is also over a meandering or sinuous path.
  • the portions of the windings which extend parallel to one another can be located comparatively close to one another so that a particularly uniform heating of the rod extending parallel thereto can be achieved.
  • the coil 15, which can be secured for example through its connecting leads to a carriage or slide can be removed by slipping it upwardly out of the meander-shaped coil which serves for preheating or afterheating the semiconductor rod and which can, if desired, be fixed in position.
  • the leads of the coil 15 for example, within the space adjacent to the illustrated space between the parallel portions of the coil 16, shown in FIG. 1a, the coil 15 can be removed by slipping it downwardly out of the meander-shaped conductor line.
  • the auxiliary coil 6 can be movably mounted so that it can carry out a movement parallel to the movement of the heating coil 15, for example also with the same speed.
  • the additional heating coil wound in meandering form can extend, for example, over a rod length of five to ten centimeters and can be displaced simultaneously with the heating coil 16 which produces a melting zone of five to fifteen millimeters length, along the axis of the rod-shaped semiconductor material.
  • the heating coil 16 can, for example, produce a melting zone of five to fifteen millimeter length and the rod-shaped semiconductor can be 20 to 50 cm. long, for example.
  • a first induction heating coil for melting a zone of the rod, said coil being located adjacent the rod and displaceable in the direction of the rod axis, and a second induction heating coil for heating the rod to V a temperature below its melting point, said second coil comprising at least one turn having portions extending substantially parallel to each other and to the rod axis.
  • stationary clamping means for rigidly clamping the rod at its ends, an induction heating coil for melting a zone of the rod, said coil being disposed adjacent the rod and movable in the direction of the rod axis between said clamping means, and a stationary, subsidiary induction heating coil for selectively preheating and after-heating the rod to a tem perature below its melting point, said subsidiary coil comprising coil turn portions spaced from the rod and extending in a direction substantially parallel to each other and to the rod axis and substantially the entire length of the rod between said clamping means.
  • stationary clamping means for rigidly clamping the rod at its ends, an induction heating coil for melting a zone of the rod, said coil being disposed around and coaxial to the rod and movable in the direction of the rod axis between said clamping means so as to move the melting zone along the rod, and a stationary, subsidiary induction heating coil for selectively pre-heating and after-heating the rod to a temperature below its melting point, said subsidiary coil comprising a plurality of coil turns having portions spaced radially from the rod and said melting coil and extending in a direction substantially parallel to each other and to the rod axis and substantially the entire length of the rod between said clamping means.
  • a first induction heating coil for melting a zone of the rod, said coil being disposed adjacent the rod and mov-. able in the direction of the rod axis, and a second induction heating coil for selectively preheating and after-heat mg the rod while the rod is in a solid state, said second coil comprising coil turn portions extending substantially parallel to each other and to the rod axis between said clamping means, said substantially parallel coil turn portions being disposed in the peripheral surface of an imagi inary cylinder coaxial with the rod and alternately connected with one another at the ends of said imaginary 1cylinder so as to form a continuous meandering conductive 6.
  • said second induction heating coil also being movable in the direction of the rod axis.
  • a first induction heating coil for melting a zone of the rod, said first coil being disposed around and coaxial to the rod and movable in the direction of the rod axis, and a second induction heating coil for selectively preheating and after-heating the rod while the rod is in a solid state, said second coil comprising coil turn portions extending substantially parallel to each other and to the rod axis between said clamping means, said substantially parallel coil turn portions being disposed in the peripheral surface of an imaginary cylinder surrounding and coaxial with the rod and said first coil and alternately connected with one another at the ends of said imaginary cylinder so as to form a continuous meandering conductive line, said first coil having a pair of end leads extending between a pair of adjacent coil turn portions of said second coil whereby said first and second coils are relatively movable apart from one another in the direction of the rod axis and in a direction in which said pair of end leads passes from between said

Landscapes

  • 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)
  • General Induction Heating (AREA)
  • Silicon Compounds (AREA)
US469048A 1963-03-29 1965-06-21 Apparatus for crucible-free zone melting of semiconductor material Expired - Lifetime US3271115A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DES84442A DE1208292B (de) 1963-03-29 1963-03-29 Vorrichtung zum tiegelfreien Zonenschmelzen von Halbleitermaterial
DES91638A DE1230763B (de) 1963-03-29 1964-06-20 Vorrichtung zum tiegelfreien Zonenschmelzen

Publications (1)

Publication Number Publication Date
US3271115A true US3271115A (en) 1966-09-06

Family

ID=25997180

Family Applications (1)

Application Number Title Priority Date Filing Date
US469048A Expired - Lifetime US3271115A (en) 1963-03-29 1965-06-21 Apparatus for crucible-free zone melting of semiconductor material

Country Status (6)

Country Link
US (1) US3271115A (xx)
BE (2) BE645736A (xx)
CH (1) CH416558A (xx)
DE (2) DE1208292B (xx)
FR (2) FR1431669A (xx)
GB (2) GB986748A (xx)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3432753A (en) * 1966-09-30 1969-03-11 Gen Electric Method of analyzing materials to determine the impurity content thereof
US3622282A (en) * 1966-12-30 1971-11-23 Siemens Ag Method for producing a monocrystalline rod by crucible-free floating zone melting
US3649210A (en) * 1965-07-10 1972-03-14 Siemens Ag Apparatus for crucible-free zone-melting of crystalline materials
US3716341A (en) * 1969-11-29 1973-02-13 Siemens Ag Crucible-free zone melting device having an angled heating coil
US3848107A (en) * 1973-12-26 1974-11-12 Park Ohio Industries Inc Inductor for heating elongated metal workpieces
US4109128A (en) * 1975-09-01 1978-08-22 Wacker-Chemitronik Gesellschaft Fur Elektronik-Grundstoffe Mbh Method for the production of semiconductor rods of large diameter and device for making the same
US4140570A (en) * 1973-11-19 1979-02-20 Texas Instruments Incorporated Method of growing single crystal silicon by the Czochralski method which eliminates the need for post growth annealing for resistivity stabilization
US4501943A (en) * 1983-09-19 1985-02-26 Gnb Batteries Inc. Apparatus and method for fusing battery terminals with improved induction heating power control
EP0292920A1 (en) * 1987-05-25 1988-11-30 Shin-Etsu Handotai Company Limited RF Induction heating apparatus

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE185464T1 (de) * 1993-08-26 1999-10-15 Inductotherm Corp Induktionsschmelzofen mit magnetischer aufhängung

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2419116A (en) * 1944-04-20 1947-04-15 Westinghouse Electric Corp Apparatus for high-frequency induction heating of strips
US2708704A (en) * 1952-04-23 1955-05-17 Lindberg Eng Co Electric heating coil structure
US2873344A (en) * 1955-08-04 1959-02-10 Kocks Friedrich Inductor device
US2935386A (en) * 1956-01-03 1960-05-03 Clevite Corp Method of producing small semiconductor silicon crystals
US2990259A (en) * 1959-09-03 1961-06-27 Paul L Moody Syringe-type single-crystal furnace
US3101400A (en) * 1961-02-23 1963-08-20 Induction Heating Corp Hardening coil and method of heat treatment of toothed metal strips
US3159459A (en) * 1958-02-19 1964-12-01 Siemens Ag Method for producing semiconductor crystals

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1045011B (de) * 1956-03-15 1958-11-27 Asea Ab Einphasiger Querfeldofen fuer die induktive Erwaermung von Werkstuecken

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2419116A (en) * 1944-04-20 1947-04-15 Westinghouse Electric Corp Apparatus for high-frequency induction heating of strips
US2708704A (en) * 1952-04-23 1955-05-17 Lindberg Eng Co Electric heating coil structure
US2873344A (en) * 1955-08-04 1959-02-10 Kocks Friedrich Inductor device
US2935386A (en) * 1956-01-03 1960-05-03 Clevite Corp Method of producing small semiconductor silicon crystals
US3159459A (en) * 1958-02-19 1964-12-01 Siemens Ag Method for producing semiconductor crystals
US2990259A (en) * 1959-09-03 1961-06-27 Paul L Moody Syringe-type single-crystal furnace
US3101400A (en) * 1961-02-23 1963-08-20 Induction Heating Corp Hardening coil and method of heat treatment of toothed metal strips

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3649210A (en) * 1965-07-10 1972-03-14 Siemens Ag Apparatus for crucible-free zone-melting of crystalline materials
US3432753A (en) * 1966-09-30 1969-03-11 Gen Electric Method of analyzing materials to determine the impurity content thereof
US3622282A (en) * 1966-12-30 1971-11-23 Siemens Ag Method for producing a monocrystalline rod by crucible-free floating zone melting
US3716341A (en) * 1969-11-29 1973-02-13 Siemens Ag Crucible-free zone melting device having an angled heating coil
US4140570A (en) * 1973-11-19 1979-02-20 Texas Instruments Incorporated Method of growing single crystal silicon by the Czochralski method which eliminates the need for post growth annealing for resistivity stabilization
US3848107A (en) * 1973-12-26 1974-11-12 Park Ohio Industries Inc Inductor for heating elongated metal workpieces
US4109128A (en) * 1975-09-01 1978-08-22 Wacker-Chemitronik Gesellschaft Fur Elektronik-Grundstoffe Mbh Method for the production of semiconductor rods of large diameter and device for making the same
US4501943A (en) * 1983-09-19 1985-02-26 Gnb Batteries Inc. Apparatus and method for fusing battery terminals with improved induction heating power control
EP0292920A1 (en) * 1987-05-25 1988-11-30 Shin-Etsu Handotai Company Limited RF Induction heating apparatus

Also Published As

Publication number Publication date
FR88198E (fr) 1966-12-23
GB1035090A (en) 1966-07-06
CH416558A (de) 1966-07-15
BE665626A (xx) 1965-12-20
DE1230763B (de) 1966-12-22
DE1208292B (de) 1966-01-05
FR1431669A (fr) 1966-03-18
GB986748A (en) 1965-03-24
BE645736A (xx) 1964-09-28

Similar Documents

Publication Publication Date Title
US3461215A (en) Electric induction furnace
US2972525A (en) Crucible-free zone melting method and apparatus for producing and processing a rod-shaped body of crystalline substance, particularly semiconductor substance
US3030194A (en) Processing of semiconductor devices
US3271115A (en) Apparatus for crucible-free zone melting of semiconductor material
US2686865A (en) Stabilizing molten material during magnetic levitation and heating thereof
US3108169A (en) Device for floating zone-melting of semiconductor rods
US2855335A (en) Method of purifying semiconductor material
US3342970A (en) Apparatus for crucible-free zone melting
US3124633A (en) Certificate of correction
US3121619A (en) Zone-melting method and apparatus
US3275417A (en) Production of dislocation-free silicon single crystals
US3100250A (en) Zone melting apparatus
US3310384A (en) Method and apparatus for cruciblefree zone melting
US3086850A (en) Method and means for growing and treating crystals
US3414388A (en) Method and apparatus for increasing the cross section of a crystalline rod during crucible-free zone melting
US3759670A (en) Initiating the pulling of a crystalline body from a molten stock
US3522405A (en) Apparatus for inductively heating metal workpieces
US3935059A (en) Method of producing single crystals of semiconductor material by floating-zone melting
US3232716A (en) Device for pulling monocrystalline semiconductor rods
US3179593A (en) Method for producing monocrystalline semiconductor material
US3296036A (en) Apparatus and method of producing semiconductor rods by pulling the same from a melt
US3134700A (en) Dislocation removal by a last pass starting at a location displaced from the original seed into the grown crystal
US3053918A (en) Apparatus for crucible-free zone melting of semiconductor rods
US2898429A (en) Crucible-free zone-melting apparatus
US3026188A (en) Method and apparatus for growing single crystals