US3160478A - Apparatus for floating-zone melting - Google Patents

Apparatus for floating-zone melting Download PDF

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Publication number
US3160478A
US3160478A US34009A US3400960A US3160478A US 3160478 A US3160478 A US 3160478A US 34009 A US34009 A US 34009A US 3400960 A US3400960 A US 3400960A US 3160478 A US3160478 A US 3160478A
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US
United States
Prior art keywords
rod
zone
holders
floating
semiconductor
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
US34009A
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English (en)
Inventor
Rummel Theodor
Heim Max
Schauer Willibald
Pfeifer Fritz
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 and Halske AG
Siemens Corp
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Siemens Corp
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 Corp filed Critical Siemens Corp
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Publication of US3160478A publication Critical patent/US3160478A/en
Anticipated expiration legal-status Critical
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
    • C30B13/32—Mechanisms for moving either the charge or the heater
    • 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
    • Y10T117/1032—Seed pulling
    • Y10T117/1072—Seed pulling including details of means providing product movement [e.g., shaft guides, servo means]
    • 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

Definitions

  • Our invention relates to an apparatus for the crucible free zone melting, also called floating-zone melting, of rod-shaped silicon or other semiconductor material.
  • a narrow zone of liquid semiconductor material is produced by an induction heater coil which is between rod portions whose ends are attached to holders.
  • the induction coil is generally caused to travel along the rod axis, so as to pass the narrow molten zone along substantially the entire length of the rod.
  • This method does not require the use of a crucible since the molten zone is kept floating between the solid portions of the rod, thus avoiding contamination of the semiconductor substance by material from a crucible wall.
  • the two rod portions attached to the holders must be shifted toward or away from each other in order to control the thickness of the semiconductor rod during the zone pulling operation. This is required, for example, to produce a rod whose diameter remains constant within a given range.
  • FIGS. 1, 2 and 3 are partly sectional front views of a different zone pulling apparatus.
  • the same references are used in all illustrations for respectively similar components.
  • the semiconductor rod 1 consisting for example of silicon, has its two ends attached to respective holders 1' and 2 and is located in a vessel of metal or quartz containing a protective gas atmosphere or vacuum.
  • the rod is first heated to make it conductive, for example by directly passing electric current through the rod, that is through the holders 1' and 2'. Thereafter a narrow zone is melted at one of the two ends. This is done by inductively heating the zone with the aid of a stationary high-frequency coil 14, which is mounted on a standard (not shown) that is entirely within vessel 10.
  • the primary of the induction heater may ice be entirely outside of vessel 10. Thereafter the molten zone is passed along the rod.
  • a screw spindle 8 is driven for example from an electric motor 81 whose speed of rotation corresponds to the desired zone-pulling speed.
  • the screw spindle 8 is in threaded engagement with a nut 9 attached to a tubular guide 4.
  • the guide memberd is connected through a second screw spindle 7 with another tubular guide member 3, both guide members being displaceably seated on an upright standard 11 of circular cross section.
  • the two rod portions 1 and 2, joined by the molten zone, are thus displaced in vessel 10 while maintaining a constant axial spacing from each other so that the molten zone is pulled longitudinally through the semiconductor rod.
  • a thickness of the molten zone and of the rod portion recrystallizing therefrom can be controlled by rotating the screw spindle '7 which is in threaded engagement with a nut 5 fastened to the tubular guide 3, and which is connected with the tubular guide 4 through a motor drive 6 mounted on guide 4.
  • spindle 7 As long as spindle 7 is at rest, the mutual spacing of the rod portion remains constant. However, when the drive 6 is actuated to revolve the spindle 7, the spacing between the rod holder 1 and 2' is changed accordingly.
  • the drive 6, preferably comprising an electric motor, can be automatically controlled for example by the anode current of a highfrequency generator which energizes the inductive heater coil 14, this anode current varying in dependence upon the thickness of the semiconductor rod passing through the coil, as is more fully explained in the copending, coassigned application Serial No. 806,174, filed April 13, 1959, now Patent No. 2,913,561.
  • the molten zone is likewise passed along the rod by revolution of the screw spindle 8.
  • the screw spindle 8 is in threaded engagement with a nut 9 firmly joined with a rail 21 which in turn rigidly interconnects the two guide members 4 and 4'.
  • the guide member 4' is rigidly connected through a screw spindle 7 with the upper guide member 3. Consequently, while the screw spindle 8 is being revolved, the two rod portions 1 and 2 are displaced along the rod axis with a uniform spacing from each other.
  • the desired upsetting or stretching of the molten zone 4, to control the thickness of the zone-melted rod is carried out by revolving the screw spindle 7, as explained with reference to the embodiment of FIG. 1. i
  • the travel of the rod along the stationary high frequency coil 14 as well as the mutual axial displacement of the rod holders 1, 2' is performed with the aid of a single screw spindle 30.
  • the spindle has two threaded portions 7' and 8' which correspond in function to the spindles 7 and 8 in FIGS. 1 and 2.
  • the uniform longitudinal displacement of the two red portions 1 and 2, with constant mutual spacing, is effected by revolving the spindle 30 with the aid of the drive 12.
  • the two holders 1' and 2 can be moved toward or away from each other.
  • the rod holders can be rotated about the axis of the rod in the same or opposite directions by means of pulleys 19 and 20.
  • the new apparatus permits the production of a hyperpure monocrystalline semiconductor rod the diameter of which is constant, or varies along the length of the rod in a predetermined, desired manner.
  • These rods are suitable for fabrication into semiconductor components, for use in transistors, rectifiers and other electronic semiconductor devices.
  • An apparatus for carrying out a crucible-free floatingzone melting of a crystallizable semiconductor rod comprising a vessel, a fixed annular induction heating coil in said vessel, the rod passing through said. coil, two

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Liquid Deposition Of Substances Of Which Semiconductor Devices Are Composed (AREA)
  • Furnace Details (AREA)
  • Manufacture And Refinement Of Metals (AREA)
US34009A 1959-06-12 1960-06-06 Apparatus for floating-zone melting Expired - Lifetime US3160478A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DES63435A DE1138375B (de) 1959-06-12 1959-06-12 Vorrichtung zum AEndern des Stabquerschnitts beim tiegellosen Zonenziehen

Publications (1)

Publication Number Publication Date
US3160478A true US3160478A (en) 1964-12-08

Family

ID=7496384

Family Applications (1)

Application Number Title Priority Date Filing Date
US34009A Expired - Lifetime US3160478A (en) 1959-06-12 1960-06-06 Apparatus for floating-zone melting

Country Status (6)

Country Link
US (1) US3160478A (OSRAM)
BE (1) BE591713A (OSRAM)
CH (1) CH392900A (OSRAM)
DE (1) DE1138375B (OSRAM)
GB (1) GB922286A (OSRAM)
NL (2) NL250401A (OSRAM)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3291570A (en) * 1963-10-22 1966-12-13 Siemens Ag Apparatus for crucible-free zone melting of crystalline rods, particularly of semiconductor rods
US3494742A (en) * 1968-12-23 1970-02-10 Western Electric Co Apparatus for float zone melting fusible material
US3660044A (en) * 1965-06-10 1972-05-02 Siemens Ag Apparatus for crucible-free zone melting of crystalline rods
US4218424A (en) * 1976-09-08 1980-08-19 Leybold-Heraeus Gmbh & Co. Kg Apparatus for the zone pulling of monocrystal rods
US5217565A (en) * 1991-11-13 1993-06-08 Wisconsin Alumni Research Foundation Contactless heater floating zone refining and crystal growth

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1195272B (de) 1961-08-31 1965-06-24 Siemens Ag Vorrichtung zum tiegellosen Zonenschmelzen von kristallinen Staeben
DE2533858C2 (de) * 1975-07-29 1983-11-17 Siemens AG, 1000 Berlin und 8000 München Vorrichtung zum tiegelfreien Zonenschmelzen eines Halbleitermaterialstabes mit in axialer Richtung feststehender Induktionsheizspule

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2913561A (en) * 1958-04-22 1959-11-17 Siemens Ag Processing semiconductor rods
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

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT194444B (de) * 1953-02-26 1958-01-10 Siemens Ag Verfahren und Einrichtung zur Behandlung einer längserstreckten Halbleiterkristallanordnung

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
US2913561A (en) * 1958-04-22 1959-11-17 Siemens Ag Processing semiconductor rods

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3291570A (en) * 1963-10-22 1966-12-13 Siemens Ag Apparatus for crucible-free zone melting of crystalline rods, particularly of semiconductor rods
US3660044A (en) * 1965-06-10 1972-05-02 Siemens Ag Apparatus for crucible-free zone melting of crystalline rods
US3494742A (en) * 1968-12-23 1970-02-10 Western Electric Co Apparatus for float zone melting fusible material
US4218424A (en) * 1976-09-08 1980-08-19 Leybold-Heraeus Gmbh & Co. Kg Apparatus for the zone pulling of monocrystal rods
US5217565A (en) * 1991-11-13 1993-06-08 Wisconsin Alumni Research Foundation Contactless heater floating zone refining and crystal growth

Also Published As

Publication number Publication date
GB922286A (en) 1963-03-27
NL250401A (OSRAM)
NL113496C (OSRAM)
DE1138375B (de) 1962-10-25
CH392900A (de) 1965-05-31
BE591713A (fr) 1960-10-03

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