US3454367A - Method of crucible-free zone melting of semiconductor material,particularly silicon - Google Patents

Method of crucible-free zone melting of semiconductor material,particularly silicon Download PDF

Info

Publication number
US3454367A
US3454367A US497681A US3454367DA US3454367A US 3454367 A US3454367 A US 3454367A US 497681 A US497681 A US 497681A US 3454367D A US3454367D A US 3454367DA US 3454367 A US3454367 A US 3454367A
Authority
US
United States
Prior art keywords
rod
cross
melting
melting zone
semiconductor material
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
US497681A
Other languages
English (en)
Inventor
Konrad Reuschel
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 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 US3454367A publication Critical patent/US3454367A/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
    • C30B13/28—Controlling or regulating
    • C30B13/30—Stabilisation or shape controlling of the molten zone, e.g. by concentrators, by electromagnetic fields; Controlling the section of the crystal
    • 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
    • Y10S117/91—Downward pulling
    • 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
    • Y10S117/912—Replenishing liquid precursor, other than a moving zone

Definitions

  • My invention relates to method of crucible-free zone melting of semiconductor material, particularly silicon.
  • Crucible-free zone melting is employed among other processes for producing semiconductor material of high purity for electronic applications.
  • a rod-shaped member of material to be processed for example of silicon, is conventionally gripped at its ends and held perpendicularly in a zone melting apparatus, for example in a vacuum chamber or in a chamber filled with protective gas.
  • a small portion of the rod length is heated by a heat source, for example by an induction heating coil or by a radiation heating source, in such a manner that a melting zone is formed at that location of the rod.
  • a heat source for example by an induction heating coil or by a radiation heating source
  • a seed crystal eg a monocrystalline rod portion grown in a preceding process
  • the entire rod-shaped member can be transformed into a monocrystal beginning at the location of this seed crystal.
  • the concentration of impurities in the material being processed is reduced or made uniform by special measures.
  • the cross-sectional area of the member being processed can be controlled or regulated.
  • the melting zone can be compressed so that the cross section of the melting zone is increased whereby the crosssection of the rod portion growing out of the melting zone is accordingly increased.
  • the melting zone is stretched or elongated so that the cross section of the melting zone is reduced, whereby the cross section of the rod portion growing out of the melting zone is also reduced.
  • a method is known, for example, from US. Patent 2,913,561.
  • This process of compressing and stretching the melting zone can be regulated in response to various measurement values, for example in response to the current supplied to the heating coil or in response to optical measurement values.
  • the regulation is carried out in such a way that the cross section of the rod is kept uniform over the entire rod length whereby wafers sliced from the rod perpendicularly to the rod axis are able to be further processed to semiconductor components without requiring further division or trimming because all of the wafers have the same area size.
  • a characteristic feature of the invention is that the size of the cross section of the rod-shaped member is controlled at least for the last pass of the melting zone through the rod so that the cross section of the rod continually increases in direction from the seed crystal to the remote rod end.
  • a semiconductor rod 2 which is held vertically, as shown in the figure, by its ends in holders 3 and 4.
  • a seed crystal 5 is fused at the lower end of the semiconductor rod 2.
  • the seed crystal 5 expediently has a smaller diameter than that of the semiconductor rod 2 which is being processed to improve the quality thereof.
  • the upper rod holder 3, for example, can be raised and lowered and thereby the melting zone 6 can be respectively stretched and compressed.
  • the lower rod holder 4 is suitably rotatable about its own axis so that the growing semiconductor material is forced to assume a circular cross section.
  • the melting zone 6 is produced by a heating coil 7 which heats the semiconductor material inductively. The travel direction of the heating coil 7 and the melting zone 6 consequently is from the bottom to the top, as shown in the figure, in a direction away from the seed crystal 5.
  • the dislocation density i.e. the number of dislocations relative to the unit area of cross section, in the rod portion extending from the seed crystal attains the desired value for example of 50,000 dislocations per cm.
  • the dislocation density will increase with increasing distance along the rod from the seed crystal and will have a value at the end of the rod distant from the seed crystal which is more than twice that at the seed crystal end.
  • the dislocation density can be maintained practically uniform and, when measured over the rod cross section, will also have no greater deviations or variations than by a factor of 1.5.
  • the semiconductor rod it is unnecessary in most cases for the semiconductor rod to be provided with longitudinally increasing cross-sectional area during the entire zone melting process for repeated passes of the melting zone but rather, such an increasing cross-sectional form or taper can be produced solely during the last pass of the melting zone.
  • a conical or tapering monocrystal suitable for subsequent processing to semiconductor components can be produced from a polycrystalline rod with only one pass of the melting zone.
  • the diameter With regard to round or circular cross sections it is suflicient in most cases for the diameter to increase about 5 mm. for a rod length of about 50 mm. so as to achieve the desired objective, namely a uniform dislocation density over the entire rod length.
  • An increase of the rod diameter should not be less than 1 mm. for a rod length of 200 mm. and an increase of 1 mm. in rod diameter for 1 mm. of rod length should not be exceeded.
  • the travelling speed of the melting zone for example should not be increased above 5 mm. per minute because, above that speed, the formation of very large transverse grooves or fissures may be anticipated, which, in such a case, will produce short negative slopes of the rod.
  • the lower limit of the melting zone travel speed appears necessarily to be 1 mm./min.
  • Method of crucible-free zone melting semiconductor material to form a crystalline member having a substantially uniform dislocation density which comprises supporting a rod-shaped member of semiconductor material substantially vertically by a holder at an end thereof, fusing one end of a seed crystal, supported by a holder at the other end thereof, to the free end of the rod-shaped member, passing a melting zone at least once along the rod-shaped member by moving the rod-shaped member and a heating device forming the melting zone in the rodshaped member relative to one another, and simultaneously moving the end holders toward one another at a constantly increasing speed as the melting zone is being passed through the rod-shaped member so that the cross section of the rod-shaped member recrystallizing from the melting zone increases in the direction of movement of the melting zone through the rod-shaped member whereby dislocations normally increasing in number with increasing distance along a recrystallizing rod-shaped member of constant cross section will have a uniform density along the recrystallized rod-shaped member of increasing cross section.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (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)
  • Silicon Compounds (AREA)
US497681A 1965-01-29 1965-10-19 Method of crucible-free zone melting of semiconductor material,particularly silicon Expired - Lifetime US3454367A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DES95239A DE1254590B (de) 1965-01-29 1965-01-29 Verfahren zum tiegelfreien Zonenschmelzen von Halbleitermaterial, insbesondere von Silicium

Publications (1)

Publication Number Publication Date
US3454367A true US3454367A (en) 1969-07-08

Family

ID=7519234

Family Applications (1)

Application Number Title Priority Date Filing Date
US497681A Expired - Lifetime US3454367A (en) 1965-01-29 1965-10-19 Method of crucible-free zone melting of semiconductor material,particularly silicon

Country Status (5)

Country Link
US (1) US3454367A (da)
BE (1) BE675593A (da)
CH (1) CH430656A (da)
DE (1) DE1254590B (da)
GB (1) GB1081827A (da)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
US5499598A (en) * 1993-03-17 1996-03-19 Tokuyama Corporation Method for producing a silicon rod

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2658368C2 (de) 1976-12-23 1982-09-23 Degussa Ag, 6000 Frankfurt Schwefel und Phosphor enthaltende Organosiliciumverbindungen, Verfahren zu ihrer Herstellung und ihre Verwendung
US5108720A (en) * 1991-05-20 1992-04-28 Hemlock Semiconductor Corporation Float zone processing of particulate silicon
US5361128A (en) * 1992-09-10 1994-11-01 Hemlock Semiconductor Corporation Method for analyzing irregular shaped chunked silicon for contaminates
US6251182B1 (en) 1993-05-11 2001-06-26 Hemlock Semiconductor Corporation Susceptor for float-zone apparatus

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2743200A (en) * 1954-05-27 1956-04-24 Bell Telephone Labor Inc Method of forming junctions in silicon
US2985519A (en) * 1958-06-02 1961-05-23 Du Pont Production of silicon
US2992311A (en) * 1960-09-28 1961-07-11 Siemens Ag Method and apparatus for floatingzone melting of semiconductor rods
US3206286A (en) * 1959-07-23 1965-09-14 Westinghouse Electric Corp Apparatus for growing crystals

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2743200A (en) * 1954-05-27 1956-04-24 Bell Telephone Labor Inc Method of forming junctions in silicon
US2985519A (en) * 1958-06-02 1961-05-23 Du Pont Production of silicon
US3206286A (en) * 1959-07-23 1965-09-14 Westinghouse Electric Corp Apparatus for growing crystals
US2992311A (en) * 1960-09-28 1961-07-11 Siemens Ag Method and apparatus for floatingzone melting of semiconductor rods

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
US5499598A (en) * 1993-03-17 1996-03-19 Tokuyama Corporation Method for producing a silicon rod

Also Published As

Publication number Publication date
GB1081827A (en) 1967-09-06
CH430656A (de) 1967-02-28
DE1254590B (de) 1967-11-23
BE675593A (da) 1966-07-26

Similar Documents

Publication Publication Date Title
US3234012A (en) Method for remelting a rod of crystallizable material by crucible-free zonemelting
US2683676A (en) Production of germanium rods having longitudinal crystal boundaries
US2743200A (en) Method of forming junctions in silicon
US3454367A (en) Method of crucible-free zone melting of semiconductor material,particularly silicon
CN107109686A (zh) 用于制造单晶硅锭的方法、以及通过该制备方法制备的单晶硅锭
US3194691A (en) Method of manufacturing rod-shaped crystals of semi-conductor material
US4722764A (en) Method for the manufacture of dislocation-free monocrystalline silicon rods
US3977934A (en) Silicon manufacture
US3351433A (en) Method of producing monocrystalline semiconductor rods
US3781209A (en) Method of producing homogeneous rods of semiconductor material
US3135585A (en) Method of growing dislocation-free semiconductor crystals
US3159459A (en) Method for producing semiconductor crystals
US3658598A (en) Method of crucible-free zone melting crystalline rods, especially of semiconductor material
US3275417A (en) Production of dislocation-free silicon single crystals
US3298795A (en) Process for controlling dendritic crystal growth
JP7067267B2 (ja) 原料結晶の抵抗率の測定方法及びｆｚシリコン単結晶の製造方法
JP2018080085A (ja) 半導体シリコン単結晶の製造方法
US5089082A (en) Process and apparatus for producing silicon ingots having high oxygen content by crucible-free zone pulling, silicon ingots obtainable thereby and silicon wafers produced therefrom
US3360405A (en) Apparatus and method of producing semiconductor rods by pulling the same from a melt
US3397042A (en) Production of dislocation-free silicon single crystals
US3935059A (en) Method of producing single crystals of semiconductor material by floating-zone melting
US3092462A (en) Method for the manufacture of rods of meltable material
US3134700A (en) Dislocation removal by a last pass starting at a location displaced from the original seed into the grown crystal
US3936346A (en) Crystal growth combining float zone technique with the water cooled RF container method
US3685973A (en) Method for crucible-free zone melting using a displaced heater