US3592455A - Device for the displacement of a solidification solid-liquid interface - Google Patents

Device for the displacement of a solidification solid-liquid interface Download PDF

Info

Publication number
US3592455A
US3592455A US879761A US3592455DA US3592455A US 3592455 A US3592455 A US 3592455A US 879761 A US879761 A US 879761A US 3592455D A US3592455D A US 3592455DA US 3592455 A US3592455 A US 3592455A
Authority
US
United States
Prior art keywords
oven
temperature
furnace
container
gradient
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
US879761A
Other languages
English (en)
Inventor
Jean Gallet
Yves Malmejac
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.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
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 Commissariat a lEnergie Atomique CEA filed Critical Commissariat a lEnergie Atomique CEA
Application granted granted Critical
Publication of US3592455A publication Critical patent/US3592455A/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
    • C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
    • C30B11/002—Crucibles or containers for supporting the melt
    • 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
    • Y10T117/1004—Apparatus with means for measuring, testing, or sensing
    • Y10T117/1008—Apparatus with means for measuring, testing, or sensing with responsive control 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
    • Y10T117/1092—Shape defined by a solid member other than seed or product [e.g., Bridgman-Stockbarger]

Definitions

  • the first group essentially involves parameters which are related to thermal phenomena and the second group involves parameters which express phenomena other than those of a thermal nature.
  • Some of the first parame' ters (such as the temperature gradient 6, within the solid near the solidliquid interface, the temperature gradient 6 within the liquid near the same interface and the solidification rate V) are determined as a result of experimental conditions imposed from the exterior whereas other parameters (such as the coefficient of thermal conductivity K of the solid phase, the thermal conductivity K, of the liquid phase, the latent heat of solidification L of the material and the temperature T of change of phase) relate to the constituents.
  • the parameters of the second group are especially the coefficients D, and D. of diffusion of the solute or solutes in the solid and liquid phases, the concentration C, of the solute or solutes at the level of the interface and the slope in of the liquidus of the phase diagram in the vicinity of the concentration C of the solutes in the liquid.
  • the solidification rate is determined by the rate of flow of heat (this rate being in turn a function of the rate of transfer through the temperature gradient).
  • this rate being in turn a function of the rate of transfer through the temperature gradient.
  • Stabilization of the gradient can be obtained only in a steady state of heat flow by reason of thermal inertia.
  • the rate of withdrawal in devices of the prior art does not correspond to the solidification rate and ratios of the order of l:3 between these two rates are attained in some cases.
  • the main object of the invention is to provide a device which removes or attenuates to a substantial extent the disadvantages mentioned above or at least the most serious disadvantages. Accordingly, the invention proposes a device for displacing a solidliquid interface along a mass of material, wherein said device comprises in combination: a container which defines a housing of elongated shape for receiving said mass of material; means for displacing said container along the axis of the housing; a first heating furnace having low thermal inertia interposed on the path of said container and equipped with regulating means for maintaining the temperature of the mass at the level of said furnace at a value close to that of the point of change of phase; a second furnace having higher power and thermal inertia than those of the first furnace, said second furnace being interposed on said path upstream of the furnace which has low thermal inertia and being intended to maintain the mass within the container at the level of said furnace at a temperature above that of the point of change of phase; means for displacing said second furnace relative to the first
  • the second furnace ensures within the mass of material a temperature distribution having a maximum value which is displaced towards the first furnace with respect to the midplane of the second furnace. It is possible by this means to produce a substantial temperature gradient within the liquid phase in proximity to the solidification interface without thereby entailing the need to heat the entire liquid phase to the maximum temperature.
  • FIG. I is a very diagrammatic view in perspective showing the mechanical portions of the device
  • FIG. 2 is a view in elevation showing the container of the device of FIG. 1;
  • FIG. 3 is an exploded view showing in perspective the casing of the container, the cradle, the screens and the cover (this latter being shown upside down);
  • FIG. 4 is a highly simplified block diagram of the regulating means which are associated with the device of FIG. 1;
  • FIG. 5 shows very diagrammatically a possible temperature distribution along the axis of displacement of the container of the device of FIG I, the outline ofthe container and furnaces being shown in dashed lines for the sake ofgreater clarity.
  • the device which is illustrated in FIG I comprises a stir tionary frame formed of a number of assembled parts and generally designated by the reference numeral It), said frame comprises a horizontal table on which are mounted flanges fut supporting the moving parts.
  • the material to be treated is placed within a container and intended to be maintained at a preselected temperature by means of de vices which essentially comprise a holding furnace I], a main furnace I4 and a cold furnace I6 which will be described in turn.
  • the holding furnace I2 is of annular shape so as to provide a passageway for the container, is of small thickness and is fixed on the table in the form of construction which is illus' trated in FIG. Since its function is limited to the supply of auxiliary heating power for regulating purposes, this furnace has only low thermal inertia.
  • the furnace 12 is fitted with a regulating device to which further reference will be made hereinafter and which is intended to permit of rapid and accurate regulation of the temperature applied to the material by the holding furnace at the level of this latter.
  • the main furnace 14 which is also oi annular shape is mounted coaxially with the holding furnace l2 and has a ther mal power rating which is distinctly higher As will be ex plained hereinafter, this furnace is fitted with a device [5 (shown in FIG. 4) which provides relatively coarse control for the purpose of temperature stabilization.
  • the main furnace I4 is capable of displacement with respect to the holding furnace 12 under the action ofa mechanism controlled by a regulating device which will be described later and is intended to maintain within the liquid phase in proximity to the liquid-solid interface a constant and predetermined temperature gradient within the material to be treated
  • the mechanism for displacing the main furnace I4 comprises two threaded rods I7 actuated by a single servomotor 18 by means of a gear train 20.
  • the ends of the two threaded rods 17 are adapted to rotate in bearings provided for this purpose in two parallel and vertical support brackets 22 and 22' which are mounted on the stationary table.
  • the frame of the furnace I4 is provided with lateral junction gussets 24 and these latter are adapted to carry internally threaded sleeves 26 into which the threaded rods [7 are screwed. The rotation of the threaded rods is thus intended to displace the furnace I4 towards the holding furnace 12 or to move it away from this latter, depending on the direction of rotation of the rods and therefore of the servomo tor 18.
  • the holding furnace l2 and the furnace [4 can be of different types, the choice being dependent in particular on the nature of the material to be treated. It is possible in particular to employ resistance furnaces. In other cases, it may be preferably to employ high-frequency induction furnaces since this expedient permits direct evolution of heat from the material to be treated provided that this latter is electrically conductive No matter what type of main furnace may be adopted, it is preferable to ensure that said furnace has a temperature dislrihutioii along its axis which is not symmetrical but has a maximum value which is displaced towards the holding furnace with respect to its midplane as indicated in FIG. 5. By producing the maximum temperature which is necessary within the material at a shorter distance from the interface, this arrange merit in fact makes it possible to reduce the total thermal power to be dissipated within the whole quantity of material.
  • the cold furnace 16 consists simply of a sleeve which is coaxial with the furnaces I2 and I4 and which is capable of axial dis placement.
  • Said sleeve is carried by a tubular traction rod 30 which is guided by the support bracket 22' and slidably fitted within this latter.
  • Said traction rod is provided with a connector 32 for the admission of a cooling fluid which is supplied through a nozzle 34 and for the discharge of said coolant through a nozzle 36.
  • the mechanism which serves to actuate the cold furnace I6 is similar in construction to the mechanism which is associated with the main furnace 14.
  • This mechanism comprises a yoke 38 which is secured to the traction rod 30 and provided with internally threaded bores.
  • Two threaded rods 40 which are parallel to the traction rod 30 are screwed into said bores.
  • the rods 40 are secured against translational motion within two support brackets 42 and 42' and are driven in rotation by an assembly consisting of a seriomotor, gear box and gear train as shown diagrammatically at 44
  • the cold furnace to is secured to the terminal portion ofthe container 46 (which is illustrated in FIGS. 2 and 3).
  • the material to be treated is placed within said container so that the mechanism for actuating the furnace 16 also constitutes the mechanism for withdrawing the container 46, that is to say for displacing along the container the solidification front of the material which is present in said container.
  • the container must have perfect thermal symmetry in order to minimize the harmful effects of convection through the container wall;
  • the container must provide the material which is present thciciii with at least partial protection against disturbing exter rial lflflllCl'iCtn in particular in the intermediate zone between the furnaces. This entails the need to ensure satisfactory heat insulation of the material with respect to the surrounding atmosphere, while nevertheless permitting (in the case of fur iiaces other than induction furnaces) the transmission of heat from these furnaces to the material.
  • This result is achieved by adopting for the fabrication of the container a material which has low thermal conductivity with respect to the conductivity of the material to be treated;
  • the container must permit of accurate temperature measurement within the material to be treated while ensuring that these measurements are not liable to disturb the transmissioii and homogeneity ofthe thermal flux.
  • FIGS. 2 and 3 The container which is illustrated in FIGS. 2 and 3 satisfies these conditions.
  • said container assumes the form of a main portion having a uniform hexagonal cross section and having sufficient symmetry about its axis to prevent any inhomogeneity about said axis, said main portion being provided with an extension in the form of a cylindrical end fitting 48.
  • Said end fitting is adapted to engage in the sleeve which constitutes the cold furnace I6 and is secured therein by means of a locking pin which is inserted in the radial bore 50 (shown in FIG. I) and the radial bore 52 (shown in FIG. 2).
  • the main portion of the container comprises a casing 54 which is rigidly fixed to the cylindrical end fitting 48 and forms a flat bottomed trough 56.
  • a cradle 58 is placed in said trough. After loading with material to be treated, the cradle 58 is covered with two thermal screens 60 and 60' and then placed within the trough 66. The casing is then closed by a cover 62 (which is shown upside down in FIG. 3).
  • the container 46 must provide a passageway for thermocouples for the purpose of measuring the temperature in the location at which it is necessary to maintain the solidification front as well as the temperature gradients on each side of said front.
  • thermocouples which are not shown in FIGS. 1 and 2), the arrangement of which is shown in FIG. 4. These thermocouples traverse the container through a lateral slit 64 formed in a lateral face of the casing and terminate near the wall of the cradle 58 after having traversed a screen 60 through a slit 66.
  • the central thermocouple 68 is mounted so as to measure the absolute value of temperature at the point at which it is located: this thermocouple will be employed as element for detecting the regulation of the holding furnace l2 which is intended to produce action so as to maintain the temperature at the level of said furnace at a value equal to the solidification point of the material to be treated.
  • the thermocouple 70 is mounted differentially so as to produce between the points 72 and 74 a signal representing the temperature difference between the thermocouples 68 and 70 and therefore the gradient in the liquid phase of the material in proximity to the solidification interface.
  • the third thermocouple 76 is mounted in a manner which is similar to the thermocouple 70 and delivers between the points 78 and 80 a signal which is proportional to the temperature gradient within the solid phase in proximity to the solidification interface.
  • thermocouples mount on an adjustable support which is not illustrated in order that the distances between them can be modified and therefore in order to measure the gradients over intervals of greater of lesser value, for example between 1 mm. and mm.
  • the regulation device which is associated with the device illustrated in FIGS. l and 2 and assumed to be equipped with resistance furnaces l2 and [4 can be of the type which will now be described by way of example with reference to FIG. 4.
  • the regulation of temperature at the level of the furnace 12 comprises a conventional electronic device 82, preferably of the type known as a "proportional-integral-differential assembly, which regulates the dissipated power in the resistors of the holding furnace 12 so as to maintain the temperature detected by the thermocouple 68 at a constant value which is equal to the solidification point.
  • the corresponding device comprises an electronic circuit 84 (as shown in FIG. 4), the detecting element of which is constituted by the thermocouple 70 which is mounted differentially with the thermocouple 68.
  • the thermal power which is dissipated within the resistors of the furnace is first set permanently at a constant value corresponding to the establishment of a suitable temperature gradient in respect of a mean position of the furnace l4 and the subsequent maintenance of said gradient is ensured by the displacements of the furnace 14.
  • the regulating device 84 in which the gradient to be established is set up controls the servomotor 18 so as to move the furnace l4 closer to the furnace 12 if the gradient is too low.
  • the regulating chain 84 can comprise, for example, an amplifier followed by a galvanometer having two adjustable index relays.
  • the interval between the current densities corresponding to the actuation of the two relays is chosen at a value such that the rates of alternating motion of the main furnace 14 are not too high.
  • the temperature gradient within the solid phase in proximity to the interface is maintained at a substantially constant value by means of an electronic system 86 and the detecting element of this latter is constituted by the thermocouple 76 which is mounted differentially with the thermocouple 68.
  • the electronic system 86 which can also be of conventional type controls a valve 88 for adjusting the rate of flow of coo mt through the sleeve which constitutes the furnace l6.
  • the regulating device which has just been described has very fast action since it eliminates any problem of thermal inertia of the furnace, is wholly independent of any possible variations in temperature of the main furnace 14 which can be stabilized by coarse control, and is not influenced by variations in heat transfer within the container (such variations being due to the finite length of this latter) since they are compensated practically instantaneously by said container, these results being achieved notwithstanding the fact that the device remains of extremely simple design. Since the regulation only takes place as a function of the temperature gradient in the zone in which said gradient plays an essential part, the invention removes the need to heat the entire liquid phase to an excessive temperature and the power consumption is reduced accordingly. This advantage is further enhanced by the dissymmetrical temperature distribution within the furnace [4: in addition to the economy achieved in heat to be transmitted to the material by the furnace 14, there is obtained correlatively an economy in the heat to be removed by the coolant.
  • the rate of withdrawal of the container can be of any desired value provided that it remains lower than the maximum speed of the main furnace 14. Moreover, it will be understood that it must be possible for all the movements to take place without inducing undesirable vibrations within the container.
  • the main furnace must have a length which is slightly greater than that ofthe mass of material in liquid phase.
  • the invention evidently permits of adaptation to a number of different alternative forms.
  • a device for displacing a solid-liquid interface along an elongated body of material in order to unidirectionally grow the solid phase comprising an elongated container for said body of material; means for displacing said container along its longitudinal direction; a first heating oven located on the path of said container and having temperature regulating means for maintaining the temperature of the body portion in said oven at a value close to the point of change of phase; a second oven having higher power and thermal inertia than those of the first oven, said second oven being located on said path upstream of the first oven in the direction of movement for maintaining the body within the container in said second oven at a temperature above the point of change of phase; means for displacing said second oven relative to to the first along said longitudinal direction; and regulating means which adjust the position of said second oven for maintaining the temperature gradient at a constant value within the liquid phase in proximity to the solidification interface.
  • the second oven is of a type providing a temperature distribution having a maximum value which is offset towards the first oven with respect to the midplane of the second oven so as to provide a substantial temperature gradient within the liquid phase in proximity to the solidification interface without thereby entailing the need to heat the entire liquid phase to said maximum temperature.
  • a device comprising a third oven or a heat sink having a temperature which is lower than that of the point of change of phase, said third oven being remote from the second oven with respect to the first.
  • said third oven is constituted by a sleeve which is attached to the container and through which is circulated a variable flow of coolant.
  • a device comprising means for measuring the temperature of the material at the level of the first oven, said means being associated with a device for regulating the dissipated puwer within the first oven to a value such that ty to the interface, said means being associated with a device said temperature xhnuid remain constant for regulating the position ofthe second oven so as to maintain 6
  • a device comprising means for measaid gradient within a predetermined range surmg the thermal gradient within the liquid phase in proximi-

Landscapes

  • 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)
  • Processing Of Solid Wastes (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Apparatus For Disinfection Or Sterilisation (AREA)
  • General Preparation And Processing Of Foods (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Liquid Deposition Of Substances Of Which Semiconductor Devices Are Composed (AREA)
US879761A 1968-12-18 1969-11-25 Device for the displacement of a solidification solid-liquid interface Expired - Lifetime US3592455A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR178906 1968-12-18

Publications (1)

Publication Number Publication Date
US3592455A true US3592455A (en) 1971-07-13

Family

ID=8658548

Family Applications (1)

Application Number Title Priority Date Filing Date
US879761A Expired - Lifetime US3592455A (en) 1968-12-18 1969-11-25 Device for the displacement of a solidification solid-liquid interface

Country Status (10)

Country Link
US (1) US3592455A (cs)
BE (1) BE741606A (cs)
CH (1) CH515070A (cs)
DE (1) DE1961545C3 (cs)
ES (1) ES374363A1 (cs)
FR (1) FR1598493A (cs)
GB (1) GB1244542A (cs)
IL (1) IL33413A0 (cs)
NL (1) NL6918967A (cs)
SE (1) SE361136B (cs)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4797174A (en) * 1986-04-28 1989-01-10 Commissariat A L'energie Atomique Process and apparatus for the continuous checking of the supermelting of the solidification front of a monocrystal during formation and application to the checking of the growth of a crystal
US5248377A (en) * 1989-12-01 1993-09-28 Grumman Aerospace Corporation Crystal-growth furnace for interface curvature control

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2876147A (en) * 1953-02-14 1959-03-03 Siemens Ag Method of and apparatus for producing semiconductor material
US3410665A (en) * 1963-08-17 1968-11-12 Siemens Ag Apparatus for producing striationless bodies of metal and semiconductor substances containing impurities

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2876147A (en) * 1953-02-14 1959-03-03 Siemens Ag Method of and apparatus for producing semiconductor material
US3410665A (en) * 1963-08-17 1968-11-12 Siemens Ag Apparatus for producing striationless bodies of metal and semiconductor substances containing impurities

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4797174A (en) * 1986-04-28 1989-01-10 Commissariat A L'energie Atomique Process and apparatus for the continuous checking of the supermelting of the solidification front of a monocrystal during formation and application to the checking of the growth of a crystal
US5248377A (en) * 1989-12-01 1993-09-28 Grumman Aerospace Corporation Crystal-growth furnace for interface curvature control

Also Published As

Publication number Publication date
FR1598493A (cs) 1970-07-06
DE1961545C3 (de) 1975-01-09
GB1244542A (en) 1971-09-02
ES374363A1 (es) 1973-03-16
DE1961545B2 (de) 1972-11-30
SE361136B (cs) 1973-10-22
IL33413A0 (en) 1970-02-19
BE741606A (cs) 1970-04-16
NL6918967A (cs) 1970-06-22
DE1961545A1 (de) 1970-07-30
CH515070A (fr) 1971-11-15

Similar Documents

Publication Publication Date Title
Burden et al. Cellular and dendritic growth. I
US3359077A (en) Method of growing a crystal
US6969502B2 (en) Method and device for growing large-volume oriented monocrystals
DE69601424T2 (de) Verfahren und Vorrichtung zur Steuerung des Kristallwachstums
US2979386A (en) Crystal growing apparatus
JPS583471B2 (ja) 耐火性複合材料より成形部材を鋳造する方法及び装置
Bilgram et al. Dendritic solidification of krypton and xenon
US4197273A (en) Apparatus for controlling the directional solidification of a liquid-solid system
Szofran et al. A method for interface shape control during Bridgman type crystal growth of HgCdTe alloys
US3592455A (en) Device for the displacement of a solidification solid-liquid interface
US3507625A (en) Apparatus for producing binary crystalline compounds
JPH10158088A (ja) 固体材料の製造方法及びその製造装置
US4510609A (en) Furnace for vertical solidification of melt
US3119778A (en) Method and apparatus for crystal growth
US5772761A (en) Crystallization furnace for material with low thermal conductivity and/or low hardness
Alkemper et al. Solidification of aluminium alloys in aerogel moulds
US4797174A (en) Process and apparatus for the continuous checking of the supermelting of the solidification front of a monocrystal during formation and application to the checking of the growth of a crystal
US4011074A (en) Process for preparing a homogeneous alloy
US4046617A (en) Method of crystallization
US5394828A (en) Apparatus for the solidification of a doped electricity conducting material and the continuous checking of its dopant content
McFadden et al. Validation of a front-tracking model of the columnar to equiaxed transition using solidification results from the Maxus 7 microgravity platform
Dupre et al. Directional solidification of the LiF-LiBaF3 eutectic
Verezub et al. Technology and Thermomechanics in Growing Tubular Silicon Single Crystals
JP3797643B2 (ja) 結晶作製装置
US3212858A (en) Apparatus for producing crystalline semiconductor material