FR2561673A1 - APPARATUS FOR REPLENISHING A MOLTEN MASS - Google Patents

Abstract

A. APPARATUS INTENDED TO SUPPLY A MELT MASS WHILE A CRYSTAL FORMATION OPERATION IS IN PROGRESS, THIS APPARATUS INCLUDING A HOLLOW DISTRIBUTION TUBE 205 AND A HOLLOW STORAGE BOX 210 SURROUNDING THEM. B. THE DISTRIBUTION TUBE 205 AND THE STORAGE BOX 210 ARE ARRANGED CONCENTRICALLY WITH RESPECT TO THE OTHER, SO AS TO REALIZE A STORAGE CHAMBER 237. A RESERVE OF STARTING MATERIAL 240 IS INTRODUCED IN THIS STORAGE CHAMBER 237 AND, AT THE FUR AND MEASURE OF CONSUMPTION OF THE MELTED MASS, THE STORAGE BOX 210 IS MOUNTED SO THAT THE MATERIAL IT CONTAINS FALLS THROUGH THE UPPER OPEN END 215 OF THE DISTRIBUTION TUBE 205 WHICH DIRECTS IT TOWARDS MASS FONDUE. C. APPLICATION: FORMATION OF CRYSTALS.

Description

The present invention relates to a device for obtaining

  crystalline bodies from a melt and, in particular,

  a refueling machine.

  Various methods have been developed for obtaining crystalline bodies from a melt. One of these methods is known as a film delivery growth technique which is lim- ited to the called wafer (also referred to as the EFG process). The details of the EFG process have been described and illustrated in U.S. Patent No. 3,591,348 issued July 6, 1971 to Harold E. LaBelle, Jr., for "Method of Growing Crystalline Materials", and U.S. Patent No. 3,687. 633 issued August 29, 1972 to Harold E. LaBelle, Jr. et al. for "Apparatus for Growing Crystalline Bodies From

The Melt ".

  According to the EFG method, a capillary formation matrix is placed in association with a melt of a starting liquid material so that a formation face of the matrix

  wetted with a liquid film of the starting material

  melt by capillary action. We then obtain

  a crystalline body by first introducing a crystal germ

  in the liquid film of the starting material to initiate the formation of crystals and then moving the crystallization seed away from the forming face at a controlled rate so that the liquid film of the starting material remains sandwiched between the crystalline body in formation and

  the forming face of the matrix. Since the liquid film

  of the starting material on the matrix forming surface is continuously replenished from the melt by

  the capillaries of the matrix, crystal bodies can be obtained

  Continuous linings of significant dimensions from the melt. A consequence of the above process is that the die material

  The liquid start of the melt is consumed during the

  crystals. So far, no reliable and efficient means have been available to continuously add starting material to the melt while EFG crystal formation is in progress. Unless it can perform a melt replenishment while the formation is

  in progress, the crystal formation operation must be complete-

  stopped to allow new starting material to be added to the spent melt. Unfortunately, the requirement to stop the crystal formation operation from time to time to recharge the melt causes some problems. In particular, stopping (and starting) an EFG crystal formation operation takes

  time and expensive cost. In addition, the obligation to stop an opera-

  formation of crystals to recharge the melt

  affects the length of the crystalline body being formed.

  tion. The maximum length of a continuous crystal that can be made is limited by the frequency at which this crystal-forming operation is to be stopped to recharge the melt. In addition, after restarting or stopping a crystal-forming operation, the crystal-forming system must readjust to or leave the optimal conditions for crystal formation. During this period of adaptation of the system, the crystal that is formed may be of a lower quality than normally obtained. Unfortunately, design requirements tend to limit the maximum practical dimensions of the crucible that contains the melt, and therefore the maximum amount of starting material that

contains the crucible at startup.

  Attempts already made to automatically introduce

  In the case of a process involving a capillary matrix or an equivalent shaper, there is a lack of additional material in the melt for a number of reasons, including excessive disruption of the melt upon entry of material. additional starting point in the crucible, unreliability, excessive dimensions, high cost and complication of element design

neighbors of the material.

  Therefore. the main object of the present invention is to provide a new means for reloading a melt while a crystal-forming operation is in progress, so that this crystal-forming operation

  can continue uninterrupted for long periods of time.

  Another object of the invention is to provide a new

  a melt-charging device, apparatus designed to recharge the melt at substantially the same rate at which the

  melt is exhausted during a crys-

  rate. Another goal is to make a reloading device

  of a melt, which is of simple construction, of

  inexpensive and reliable operation.

  Another object of the invention is to provide a melt charging apparatus which can be used in conjunction with a crystalline body forming apparatus in accordance with the present invention.

  in the EFG5 process as well as in conjunction with a

  crystalline bodies according to other methods.

  Another object of the invention is to provide a

  a charging coil of the melt capable of operating from a position within a hollow crystalline body as

  the body is formed from the melt.

  These and other goals are achieved according to the present invention.

  thanks to a new device for refilling a melt comprising a hollow dispensing tube surrounded by a hollow storage box. The hollow distribution tube comprises a wall

  side, an open upper end and an inferior extremity

  the hollow storage box, in turn, comprises a side wall, an open upper end and a closed lower end, the closed lower end of the storage box being pierced with a central opening. The distribution tube and the box are arranged concentrically

  relative to each other5 the side wall of the distribution tube

  Bution is smoothly slidingly received in the central opening of the closed bottom end of the storage channel. The upper end of the dispensing tube is located inside the storage box while its lower end is on the outside of the storage box. Inside the storage box, between the side wall of the distribution tube and the side wall of the storage box, a reserve of starting material is placed to be added to the melt, the lower end of the dispensing tube being positioned above the melt to be refilled. When forming crystals, we move

  the storage box upwards relative to the distribution tube

  bution and, as it moves, the starting material contained in the storage box is carried upward beyond the upper end of the dispensing tube and falls automatically, under the effect of the gravity, in the open upper end of the dispensing tube which

directs in the melt.

  An embodiment of the present invention is hereinafter described by way of example with reference to the accompanying drawings, in which: - Fig. 1 is an oblique view of the preferred embodiment of the present invention, some portions being cut away; ; FIG. 2 is a sectional view, in side elevation, of the apparatus of FIG. 1; FIG. 3 is a sectional view, in side elevation,

  showing how the present invention can be incorporated into

  in a typical EFG crystal forming apparatus; - Figure 4 is a partial sectional view along the line 4-4 of Figure 3; and FIG. 5 is an oblique view showing another way of incorporating the present invention into a

formation of EFG crystals type.

  Referring first to Figures 1 and 2, the preferred embodiment of the present invention generally includes a hollow dispensing tube and a storage box.

hollow 10.

  The dispensing tube 5 is cylindrical, comprising a side wall 12, an open top end 15 and a

open bottom end 20.

  The storage box 10 is cylindrical, comprising a side wall 22 and an open upper end 25. Its lower end is closed by an end wall 30. The inside diameter of the box is substantially larger than the outside diameter of the tube. distribution. The end wall

  lower 30 is pierced with a circular central opening 35.

  The opening 35 is dimensioned so that its diameter is only

  slightly greater than the outside diameter of the dispensing tube

  tion. The distribution tube 5 and the storage box 15 are

  concentrated concentrically and telescopically, the distribution tube

  Bution is received in the opening 35 of the storage box 10 to allow it to slide smoothly. The upper end of the dispensing tube 15 is disposed inside the storage box 10 while its lower end 20 is disposed outside the storage box 10.o The side wall of the dispensing tube 12 and the side wall 22 of the box delimit between them an interval or a region 37. The region 37 constitutes a variable volume storage chamber. The volume of the chamber 37 varies according to the movement of the storage box 10 in an axial direction relative to the

dispensing tube 5.

  To prepare the apparatus that has just been described for use, the dispensing tube 5 is first placed so that its open lower end 20 is located directly above the melt to be refilled. Next, the storage box 10 is placed on the dispensing tube 5 for

  a significant part of the side wall of the distribution tube

  FIG. 12 extends beyond the closed lower end wall 30 of the storage box as shown in FIGS. 1 and 2. Next, a quantity of storage box 10 is placed in the storage box 10.

  starting material for recharging the melt (generally

  in the form of small pellets or chips.

  to fill chamber 37, as shown in FIG.

  When filling, the box 10 must be positioned so that

  the chamber 37 has a maximum volume.

  To subsequently introduce the starting material 40 into the melt, as needed, simply move the

  storage box 10 upwardly relative to the dispensing tube

  This action has the effect of bringing the level of the starting material 40 in the chamber 37 above the level of the open upper end 15 of the dispensing tube. As this displacement proceeds, the highest starting material falls, under the effect of gravity, into the open upper end of the distribution tube which directs it to the melt located directly below the open lower end 20 of the dispensing tube (see Figure 2). As the storage box 10 is moved upwardly, starting material contained in the chamber 37 falls into the tube 5 which directs it to the melt. The continuous upward movement of the storage box 10 relative to the distribution tube 5 will result in the substantially continuous introduction of additional starting material into the mass.

  melted until the starting material contained in the

  Tervalle 37 is running out. Stopping the movement of the box 10 is

  will result in the discontinuation of the introduction of additional starting

in the melt.

  By appropriate sizing of the dispensing tube and the storage box 10, and by fittingly adjusting the speed of movement of the box 10 relative to the tube 5, it is possible to ensure that the device described ensures continuous introduction into the melt of additional starting material at substantially the same rate at which the

  Starting material is depleted in the melt during an operation.

formation of crystals.

  Figures 3 and 4 show the present invention incor-

  pored in an EFG crystal formation apparatus. Except

  As indicated below, the melt charging apparatus is substantially the same as that shown in FIGS. 1 and 2 and described above, and the EFG crystal forming apparatus is substantially the same as the apparatus described and illustrated by the American patent application on behalf of RW Stormont et al., No. 289,410, filed August 3, 1981 for

  "Apparatus for Growing Tubular Crystalline Bodies".

  More specifically, the EFG crystal forming apparatus generally comprises a furnace enclosure 110, in which a crucible 112, a capillary matrix 114 constituted in part by the crucible, a thermal susceptor 116 are arranged.

  of the crucible, two hollow and concentric sets of post-

  warming 118 and 120, a seed carrier assembly 122 and a melt charging apparatus 200. As will be described in more detail below, a portion of the charging apparatus 200 is movably carried by a rod 124 attached to a pull mechanism 126. The oven enclosure 110 is surrounded by a radiofrequency heater coil 128 which is connected to a controllable radio frequency power source (not shown) of conventional construction. In operation, the crucible 112 is filled with an initial charge 130 of the material

  crystal formation (for example silicon, alpha-

alumina, and the like).

  More specifically, the furnace enclosure 110 is made

  from two cylindrical quartz tubes, concentric and spaced from each other. Although this is not represented,

  the furnace enclosure 110 is closed up and down to allow

  to control the environment inside the enclosure.

  The crucible 112 is a short, hollow, upwardly open circular cylinder disposed in the center of the enclosure 110. The crucible 112 is made of a material compatible with the crystal-forming material, that is, if it is is training

  of a silicon ribbon, the crucible 110 is made of graphite.

  The capillary matrix 114 is an integral part of the side wall of the crucible 110, as described in US Pat. No. 230,674. The die 114 has an upper end face 132 shaped and dimensioned to allow the shape and size of the die to be controlled. crystal in formation. Thus, for example, the face 132, seen in plan, consists of a regular thin-walled hollow polygon.

  cutre! its center a capillary interval 134 of similar shape

  ford. A plurality of elongated slots 135 are made in the

  side wall of the crucible 112, to ensure the

  nication between the capillary interval 134 and the interior of the crucible, so that the melt load 130 can flow to the capillary range in which it mounts by capillary action to replenish the face 132 with respect to measurement of crystal formation. Like the crucible 112, the capillary matrix 114 is made of a material compatible with the crystal-forming material, for example if it is the formation of a silicon ribbon, the capillary matrix 114 is

in graphite.

  The thermal susceptor 116 is generally constituted by a short hollow body, open upwards, and having dimensions enabling it to receive the crucible 112. The height of the susceptor 116 is selected so that the capillary matrix 114 can extend upward beyond the top of the susceptor. The susceptor 116 is of a suitable material, the choice being a function in part of the available excitation frequency of the heating coil 128 and partly of the compatibilities of the various materials present inside the oven. If it involves the formation of a silicon body, the

susceptor 116 is graphite.

  The top of the thermal susceptor 116 may include an outer shield of radiation protection 136 under

  thin-walled hollow body shape having a shape and size

  similar to those of susceptor 116 and include

  generally having an inner rim 137 having a shape

  similar to that of the end face 132 of the capillary matrix

  114. The flange 137 is located substantially in the same plane as the end face 132 but is separated from it. The shield

  outside protection against radiation 136 is preferably

  In this case, the molybdenum in the case of the formation of a silicon crystal inside the capillary matrix 114 is formed into an inner protective shield 38. This shield 138 comprises generally a piurality of graphite plates parallel to each other and spaced opposite each other. The shield 138 is pierced by a circular central opening 139. The inner shield 138 may be brought to a distance from the die 114 by a plurality of pins 140 disposed on the inner periphery of the

matrix 114.

  Heater positions 118-120 are disposed above the end face 132 of the die and concentrically to it. The external heater-station 118 is in the form of an open end straight prism, its lower end face having the same shape as the end face 132 of the

  matrix but larger than that, that is to say the lateral faces

  the post-heater 118 are arranged parallel to the corresponding side of the polygon formed by the end face 132,

  and extend substantially normally to the plane of the face of ex-

  132. In general, the post-reheat

  118 is a double walled structure, comprising an inner wall of graphite 142 and an outer wall 144 provided with an outer insulation of carbon felt. The post-heater 118 is carried by a plurality of pins 146 to move it away from the

  edge 137 of the outer shield 136.

  The inner heater 120 comprises a cylindrical wall

  148, a top plate 150 and a conical lower section 152. The cylindrical section 148 has a diameter

  less than that of a circle tangent to the inner edges.

  The upper plate 150 is pierced with a central opening 153.

  section 152 has the shape of a hollow truncated cone with

  open tees attached by its large diameter end to the end

  lower integrity of the cylindrical section 148. The end of

  The small diameter of the conical section 152 has a substantial diameter.

  identical to that of the central aperture 139 of the shield

  138. With the exception of the top of the integral heating station

  120, the walls of each section are generally of a conaffruction single wall. Typically, however, the top of the inner heater 120 is of double-walled construction with the upper plate 150 carrying a smaller diameter carbon felt insulation blank 154. The insulating blanket 154 is pierced with a central opening 155 identical to the opening 153 of the upper plate 150. The inner heating station 120 is carried on the upper face of the inner shield 138 by its conical section 152. cylindrical 148 of the inner post-heater is arranged so that its cylindrical axis is substantially perpendicular to the plane of the face

132 end.

  The seed carrier assembly 122 includes a seed carrier 156 and a seed 158. In the case of forming a silicon crystal, the seed carrier 156 is made of graphite. The seed carrier 156 is a plate of a size and shape similar to that of the end face 132 of the die 114. The seed holder 156 is pierced with a central hole 160 which is enlarged in a second position. The seed carrier 156 is pierced with a plurality of radial openings

164 gas passage.

  The seed 158 is preferably a short section of a crystalline body previously made using the same apparatus. The length of the seed 158 is chosen to exceed the overall height of the post-heater 120 by the thickness of the seed carrier 156. The seed 158 can be fixed on the seed carrier 156 by

graphite screw.

  The apparatus 200 for recharging the melt comprises a dispensing tube 205 and a storage box 210. The dispensing tube 205 and the storage box 210 are made of a material compatible with the crystal forming material, for example This is the formation of a silicon ribbon, the tube 205 and the box 206 are made of quartz and / or vitreous carbon. The distribution tube 205 has its lower end fixed to the inner shield 138 by a plurality of

  graphite supports 211 (FIGS. 3 and 4), so that the end

  lower half of the distribution tube is disposed directly above the melted charge 130 that contains the crucible 112. The

  distribution tube 205 extends upward substantially

  perpendicular to the plane of the end face 132 of the matrix

  It this, through the openings 153 and 154 of the plate 150 and the mattress 154 and finally cross the counter-aldsage 162 and the hole

of the seed carrier 156.

  The storage box 210 receives the dispensing tube 205 in the manner of a telescope, as noted above, so as to delimit a storage chamber 237 between the outer surface of the dispensing tube and the inner surface of the side wall. from the storage box. The dispensing tube 205 further extends substantially perpendicular to the plane of the end face 132 of the die through the openings 153 and 155 of the plate 150 and the mattress 154 and the counterbore 162 and the hole 160 The storage box 210 has dimensions such that the outer surface of its side wall 222 fits smoothly to the plate 150 and the mattress 154. At the same time, the box 210 has dimensions such that the diameter of its side wall 222 is substantially smaller than the hole 160 of the seed carrier 156. However, the box 210 further comprises an outer circular flange 274 located at an intermediate position of its length, a collar which

  engages hard friction in the counter-bore 162 of the holder

  The flange 274 comprises a plurality of ventilation openings 278 arranged so as to be located inside.

  160. The flange 274 is disposed on the cylindrical box.

  210 so that the distance between the collar and the end

  The lower closed 230 of the box is somewhat less than langueur seed plates 168, for reasons that will be explained below. The upper end of the cylindrical can 210 is removably attached to the rod 124 by well known means, for example screws. The rod 124 is attached to a pull mechanism 126 by known means. pulling mechanism 126 pulls the stem 124 var.le..aut, the storage box 210 will move upwards relative to the distribution tube 205 and the crucible 1120 Lrs- of the assembly of the apparatus described above, it is first fixes the seed 158 on the seed holder 156e. The cylindrical coit 210 is then introduced into the central hole 160 of the seed carrier.

  156 so that his collar 274 comes to fit into the counter

  Bore 162 for supporting the seed carrier 156. Of course, when the seed carrier 156 is supported in this way by the flange 274, the lower end of the seed 158 protrudes from the closed lower end 230 of the can 210 Then, the storage box 206 is nested on the tube of

  distribution 205 and down until the end

  lower mite 158 is close to the upper end face 132 of the die without being in contact with

iO her.

  In this respect, it goes without saying that, since the seed 158 is sized to protrude downwards the bottom of the germ carrier 156

  a distance greater than the height of the heating station

  120, the seed 158 will come into contact with the end face.

  mite 132 of the matrix before the seed carrier 156 enters into

  contact with the insulation blanket 154 located on the warming station

  feur. Moreover, it is obvious that, because of the

  In the case of the flange 274 on the cylindrical box 210, the seed 158 will contact the end face 132 of the die before the closed lower end 230 of the box can come into contact with the supports 211 which extend between the lower end of the delivery tube 205 and the

  inner shield 138 of radiation protection.

  The starting material 240 is then introduced into the chamber 237 until it is at the upper end of the dispensing tube 205. The apparatus is then ready to begin formation of a crystal. (It should be noted that, at startup, the crucible is filled with starting material to form the slotted mass 130 and the material contained in the chamber 137 is intended to replace the initial charge in the crucible.

  as it is consumed by the formation of cristali.

  The oven is heated to melt the charge in the crucible. The face

  the end 232 of the matrix is brought to a zup-

  below the melting point of the constituent material of the seed 205 and the seed is then lowered until it comes into contact with the end face 132 of the matrix. the seed portion in contact with the matrix will melt, thereby wetting the end face and connecting it to the melt in the

  capillary 134. Then, the mechanism of trac-

  126 to mount the rod 124 and, with it, the storage box 210. As the box 210 mounts along the dispensing tube 205, the fact that its flange 274 engages with the seed carrier, the it is also worn up. As the germ carrier goes up, the seed 158 moves away from the

  matrix and the melt of the germ wetting the end face.

  Mite of the matrix is stretched by the surface tension into a thin film between the seed and the end face of the matrix. As the seed carrier continues to move away from the end face of the matrix, the portion of the most liquid film

  near the germ 158 undergoes a drop in temperature. More precise

  it begins to solidify as its temperature falls below the melting point of the starting material, thereby forming the desired crystalline structure. Meanwhile, the melt starting material 130 mounts by capillary action to replace the starting material wetting the end face of the die, thereby enabling formation

continuous crystals.

  In conjunction with this crystal formation, the upward movement of the box 210 causes the starting material in the storage chamber 237 to rise past the top of the tube 205, so that it falls under the effect of gravity, in the tube

  distributing it to the melt 130. The material

  The solid starting point added liquefies under the effect of continuous heating and merges into the melt. Thus, the melt is continuously replenished by the starting material

  new, until exhaustion of the additional starting material

shut up in the storage box.

  By connecting the melt replenisher 200 to the same pulling mechanism 126 which moves the crystalline body away from forming the end face of the die, it is certain that the material replenishing apparatus will be automatically stopped. supplying the melt with respect to additional departure if the crystal-forming operation is stopped and temporarily. In addition, by judiciously choosing the dimensions of the distribution tube 205 and the storage box 210, relative to each other, as well as to the crystal-forming furnace, the speed at which the apparatus feeds the melt almost exactly at the rate of consumption of the material of

  start in the melt. So, if the speed of training

  If the crystal speed increases, the feed speed will automatically increase correspondingly and, if the speed of

  formation of crystals decreases, the feeding speed decreases

  ra automatically correspondingly.

  By way of example, in the case of a non-82 cm long silicon crystal, whose growth is carried out at a rate of approximately 2.54 cm per minute, it has been found that the starting material can replaced at a rate substantially identical to that of its consumption using a storage box with an outside diameter of 3.94 cm (wall thickness 1.016 mm), an outer diameter 2.49 cm (wall thickness 1.016 mm), with a can rise speed of 2. 54 cm / min. The use of a storage box with a length of 71.12 cm and a distribution tube with a length of 38.1 cm, allows to feed the crucible in terms of additional departure

  to extend the time between stops by around 300%.

  It goes without saying that modifications may be made to the preferred embodiment described above without however

depart from the scope of the invention.

  Thus, for example, the dispensing tube could be supported above the melt in a manner other than that shown in Figures 3 and 4. More specifically, as

  shown in FIG. 5, the lower end of the dispensing tube

  The bution could be attached to a support column 305 by means of a plurality of arms 310 constituting a truncated cane-shaped assembly, and the support column could have its lower end attached to the bottom surface of the crucible. it would extend perpendicularly upwards. The starting material falling in the delivery tube would fall between the arms 10 before reaching the melt. Of course, because according to this arrangement, at least a portion of the support column 305 would be disposed directly in the melt, the column should be made of a material compatible with the crystal formation material, which is say if it's about the formation of a silicon ribbon, the column of

support 305 must be in graphite.

  The distribution tube and the storage box could

  also have shapes in cross-section other than cir-

  eyelike, for example they might have shapes in section

  polygonal, or they could have shapes in different sections

  for example one that can be circular and the other polyg -

  nal. Of course, the central opening of the lower end wall of the box must have a shape corresponding to the cross-sectional shape of the dispensing tube, so that

  the end wall of the box provides a possibility of sliding

  friction with the side wall of the distribution tube.

  bution. Of course, it is not required that the matrix 114 has an upper end surface having the shape of a

  regular polygon. The matrix could be adapted to the training

  tubing of circular cross section. It is easy to see that the storage box could be pulled upwards along the dispensing tube by a separate device from the device which raises the germ carrier. In addition, the melt replenishing apparatus can It operates differently than described above. For example, one could achieve the same result by now holding the fixed storage box and moving the iis tube; ribution down from the storage box. In

  In addition, additional departure may be required.

  Ge of the melt-supply apparatus moving the storage box upwards and, at the same time, the dispensing tube: downwards. Other modifications of this type could be considered without

  however, out of the scope and spirit of the invention.

  The present invention provides many advantages.

  First, the present invention provides a melt supply apparatus during a crystal-forming operation, so that the crystal-forming operation can continue uninterrupted.

  for longer periods of time.

  Secondly, the present invention makes it possible to obtain an apparatus capable of performing the melt replenishment substantially at the same speed as its consumption during a

  crystal formation operation.

  Thirdly, the present invention makes it possible to obtain an apparatus for replenishing the melt which is of simple construction, of inexpensive manufacture and of

reliable operation.

  The present invention is furthermore suitable for use with

  crystalline body forming films according to the EFG method as well as apparatus for body formation

  crystalline according to other known methods.

  Another advantage provided by the present invention is that

  the device simultaneously ensures (1) the removal of the crys-

  tallin in formation of the matrix forming face and (2) the replenishment of the melt in starting

additional.

  Another important advantage provided by the present invention

  tion is that the new supply device is compact and can operate from a position indoors

  of a hollow crystalline body in formation.

  Other advantages will be apparent to those skilled in the art.

Claims (8)

  An apparatus for replenishing a melt comprising a hollow dispensing tube and a hollow storage box, the hollow dispensing tube (5) comprising a sidewall (J2), an open top end (15), and an open lower end (20), and   the hollow storage box (10) comprising a side wall   groove (22) and an end wall (30) closing its lower end, said end wall being pierced with a central opening (35), characterized in that the distribution tube (5) and the storage box (10) intertwined concentrically into each other in the manner of a telescope so as to delimit a   variable-volume annular chamber (37) between their lateral wall   the, the side wall (12) of the distribution tube (5) engages with   both frictionally hard in said central opening (35) and in that the dispensing tube (5) has its open top end (15) disposed inside the storage box (10) while its lower open end ( 20) is disposed on the outside of the storage box (10), so that if the additional melt replenishment starting material (40) is placed inside said chamber (37). and if positioning the lower end (20) of the dispensing tube (5) over a melt to be   replenished, a subsequent displacement of the storage box   ge (10) upwards relative to the distribution tube (5) will result in an overflow of the starting material (40;   contained in said chamber (37) and its introduction in the former   open upper end of the dispensing tube (5) which. the directs to said melt.   2. Apparatus according to claim 1, characterized in that   the hollow distribution tube (5) has a transverse section   circularly dirty and in that the opening (35) made in the lower e ner (30) of the storage box (10) presents a circular shape.   3. Apparatus according to claim 1, characterized in that   the storage box (10) has a circular cross section.   4. Apparatus according to claim 1, characterized in that the distribution tube (205) is supported above the melt by a plurality of supports (211) attached to a crucible   containing the melt, said supports extending substantially   radially from the side wall of the distribution tube. bution (205).   5. Apparatus according to claim 1, characterized in that the dispensing tube (205) is supported above the melt by a support column (305) and a plurality of support arms (310), the column of support extending vertically from the bottom of the crucible enclosing said melt, while said plurality of support arms extend between the   support column and the distribution tube.   An apparatus for forming crystalline bodies from a melt of a selected starting material, comprising: a) a crucible (112) for containing a quantity of the starting material; b) a crystal forming member (114) disposed within the crucible; c) means for heating the crucible;   d) means (156) for carrying a crystal seed   (158) and removing said seed and a crystalline body in formation from the crystal shaper (114); and e) means for replenishing the crucible (112) with additional starting material to replenish the melt,   the hollow distribution tube (5) comprising a side wall   an upper open end (15) and an open lower end (20); and   a hollow storage box (10) comprising a side wall   (22) and an end wall (30) closing its lower end, said end wall being pierced with a central opening (35); characterized in that the dispensing tube (5) and the   storage box (10) are arranged concentrically in the manner   telescope relative to each other so as to delimit between their respective lateral walls 12, 22, an annular chamber with variable volume (37), the lateral wall (12) of the distribution tube (5) is frictionally engaging the central opening (35) and that the dispensing tube (5) has its open upper end (15) disposed inside the storage box (10) and its lower open end ( 20) disposed outside the storage box (10) and above a crucible, so that, if it has in said chamber   (37) of the additional starting material (40) for   provision the melt, a displacement of the storage box (10) upwardly relative to the distribution tube (5) will result in an overflow of the starting material (40) contained in said chamber (37) and its introduction in the open upper end of the dispensing tube (5) which directs to said crucible.   7. Apparatus according to claim 6, characterized in that the traction means (126) are arranged to move the storage box (10) upwards relative to the distribution tube (5) 1 as the traction means away a seed (158)   the crystal shaping member (114).   8. Apparatus according to claim 6, characterized in that the traction means comprise seed carrier means (156) adapted to carry an elongated hollow seed (158) which extends   around the dispensing tube and the storage box.