A technique for replenishing molten, levitating material by growing monocrystalline, polycrystalline, or other solid-state structures under electromagnetic levitation conditions

Abstract

The invention relates to the metallurgy and crystal growing industry, as well as to the physics and astronomy fields, where electromagnetic levitation is used to hold the molten zone and shell-less growing technology is used. A technique is proposed to use the principle of levitation and realize the replenishment of the molten, levitating material from above (under gravity) in the EM levitation coil, forming the material to be replenished - a workpiece in an arbitrary tubular shape or a tubular composition of rods of the replenishable material, which are immersed in the molten material from above, in order to compensate for material losses caused by the extracted crystal structure. Compensating for material losses allows growing crystals whose size is not limited by the volume of simultaneously levitated material. The arbitrary tubular shape or tubular composition of the filler material protects the crystallization zone and the grown crystal from the high-intensity EM field, and reduces both the temperature gradient and the turbulence, optimizing the crystal growth conditions in the crystallization zone, which allows to improve the quality of the grown crystals.

Description

A technique for replenishing molten, levitating material by growing monocrystalline, polycrystalline, or other solid-state structures under electromagnetic levitation conditionsField of the invention

[0001] The invention relates to the metallurgy and crystal growing industry, as well as to the physics and astronomy industries, where an electromagnetic field is used to hold the molten zone and a shell-less growing technology is used.Background o f the art

[0002] Various techniques are known for growing monocrystals. One of the first and once, one of the most widely used crystal growing techniques is the Czochralski technique, in which a crystal is grown from a large mass of molten material contained within an outer shell / crucible. In order to prevent the contact of the molten material with the walls of the outer shell, it is possible to use the layer of the meltable material (the crystal blank of the meltable material in the form of granules) as the walls of the container. The term "crystal blank" refers to a piece of material formed in a certain shape, in a solid phase, which is intended for melting. A crystallographically correctly oriented single crystal, which acts as a crystal seed, is brought to the surface of the molten material. It is essential that the temperature at the point of contact between the crystal seed and the molten material (we will call this point of contact the "crystallization zone") should be close to (or slightly below) the melting / crystallization temperature of the material. Atoms of the molten material condense on the surface of the crystal seed as the seed is slowly pulled upwards. As a result, a monocrystal of considerable size can be grown from a crystal seed. The technique is used in the growth of slow-growing, large-sized semiconductor crystals. The principles of shell-less melting and electromagnetic (EM) levitation are not applied in this technique.

[0003] There is also technique known as “floating zone” method, which is based on local melting of the material with a high-intensity electromagnetic field. [1] The "needle eye" technique is a sub-type of floating zone technique that allows crystals to be grown without physical contact between the molten material and the crucible / shell containing it. In this technique, the crystal blank is pushed in a vertical downward direction (parallel to the gravity vector) through the "needle eye" in the centre of a coil wound in a horizontal plane, which completely melts the material blank in a limited area of space. By passing through the “needle eye", the material flows over the surface of the growing crystal, cools and crystallizes without coming into contact with the outer walls of the vessels. Depending on the process parameters, it is possible to grow monocrystals with a diameter larger than the diameter of the crystal blank.This technique is widely used to grow high-quality Si crystals. However, it must be taken into account that this process is affected by the viscosity of the molten material, the surface tension and the permissible rate of crystallization. For this reason, the "needle eye" technique is not used to grow germanium crystals. With a specific coil configuration, it is possible to compensate the gravitational force with electromagnetic lifting force / pressure and also achieve the process with the opposite direction of movement of the crystal blank and the growing crystal relative to the coil - the material blank is pushed in the "up" direction and the molten material is lifted and crystallizes above the "needle eye". It should be noted that, compared to the Chochralski method, the crystals grown by the "needle eye" method have many times fewer impurities and the total density of defects is significantly lower. However, strong EM field and temperature gradient effects still exist as a source of dislocations in the grown crystals.

[0004] EM levitation in metallurgy is used for the formation of various alloys, when physical contact of the molten material with the crucible / shell is not desired or in cases where the production of the shell is irrational or its melting temperature is lower than the melting temperature of the melt. [2] Unlike the floating zone technique, where the coil windings act only as heating elements, in this case the EM field created by the inductor must hold and stabilize the molten material. In order for the coil to generate lift force, the EM field it creates cannot be homogeneous in the direction of the vertical axis. One of the most effective EM levitation coil configurations that generates a significant EM field gradient along the vertical axis is a coil with counter-turn, where the counter-turn windings (one or more) increase the EM field gradient along the vertical axis, thus increasing the lift force in the region between the normal and the counter-turn windings. [3]

[0005] To use the technique in metallurgy, after melting the material in the EM field, the liquid phase obtained can be poured into a mold, where it rapidly cools and solidifies. If it is necessary to obtain a material with a high quality crystalline structure (or other type of solid) from the molten material, the liquid phase must be cooled in a controlled manner so that the atoms of the material can arrange themselves in a crystalline (or other type) structure without creating unwanted defects. The EM field creates both lift force and heating, as well as strong turbulence, which makes it difficult to control and regulate the temperature of the molten material in the crystallization zone. In EM levitation, the temperature of the molten material is primarily determined by the properties of the material, the geometry of the EM coil and the parameters of the electric current source. There are several techniques to influence the temperature of molten material in EM levitation. One of these techniques is to change the alternating current frequency and match the value of the current in the EM levitation coil to compensate for changes in the EM lift force. [4] There are also patents for dynamic changes in the geometry ofEM coils, where the parameters of the EM field are regulated by controlling the spatial arrangement of the coil turns. [5] The temperature of the molten material can also be influenced with the help of gas flow, with an infrared radiation-absorbing cover, or by additional heating with various methods (lasers, infrared radiation, etc.). Attempts have been made to crystallize molten material in EM levitation conditions, with success so far only in the case of very small crystals, as no replenishment of the molten material was performed. [6]

[0006] It is possible to grow a crystal from the material melted levitation conditions in the EM levitation coil analogously to the Czochralski technique - with the help of a crystal seed. In weightless conditions, growing crystals in an EM field would be significantly easier [7], unfortunately, transporting crystals and crystal blanks from / to Earth's orbit is not yet economically viable option. In the Earth's gravity, in the conditions of electromagnetic levitation, the amount of material that can be held at the same time is limited by the geometry of the EM coil and the power supplied to it at the frequency of alternating current used. Stable levitation (equilibrium state) in the EM coil is possible only in the area where the force of the electromagnetic interaction is positive with a negative derivative in the vertical, upward direction (by the bottom we mean the direction of action of the forces of gravity or some other external force, such as light pressure, electrostatic, etc. - if material moves down, lift increases). We will call this area the “levitation zone”, where stable material retention is possible. Heat generation in the levitating material is proportional to the square of the EM field strength. Along the vertical axis of EM levitation coil, the highest EM field intensity in EM coils is observed in the region of space where the EM force changes direction, and this location will always be offset relative to the levitation zone. If we denote the region of space along the vertical axis of EM levitation coil, where most of the heat (-50%) is generated, by the term "heating zone", then under the conditions of Earth's gravity the heating zone will always be below the levitation zone.

[0007] There is also a semi-levitation crystal growing technique, which can be described as a hybrid of Levitation and Czochralski techniques, where the force of levitation holds only part of the molten material. In one example of the semi -levitation technique, a portion of the molten material in the EM coil rests on a crucible / shell base that is covered with a solid layer of the same material. The levitation force acts on only a portion of the material and pushes the molten material away from the sides of the crucible / shell. [8] There have also been attempts to create a shell-less semi-levitation system, where a crystal blank, being fed from below, would act as an additional support for the molten, levitating material, but these efforts have not yet been crowned with success, because when sliding the crystal blank from below, it passes through the heating zone of the inductor. If the movement of the crystal blank is not fast enough, it will meltbefore entering the levitation zone of the inductor. For very slowly growing crystals, it is not practically feasible to realize a sufficiently slow workpiece movement speed.

[0008] The techniques described above have the following shortcomings: a) The EM field acting on the crystallization zone and the crystal grown in the crystallization zone increases the thermal gradient that causes dislocation defects in the grown crystals. b) The size of the crystals grown in the EM levitation process is limited by the amount of material that can be held simultaneously in a stable equilibrium state.Summary of the invention

[0009] In order not to limit the size of the grown crystals by the volume of the levitating material, it is necessary to supplement the volume of the molten material (to compensate for the loss of material in the molten volume in the process of crystal extraction). The principle of levitation ensures shell-less melting technology. The term "crystal" will be used hereinafter to refer to any solid state structure, including monocrystalline, polycrystalline, and other solid state structures (e.g., amorphous structures). The technique described here is intended for the growth of monocrystalline and polycrystalline structures, but can also be applied to obtain any (including amorphous) solid state structures.

[0010] The term "bottom" denotes the direction in which an external net force (gravitational force, light pressure force, electrostatic force, etc.) is acting on the levitating (held) material. The term "top" refers to the opposite direction.

[0011] The term "rod" refers to crystal blanks of long, indefinite shape.

[0012] The term "tube" refers to a long, hollow geometric shape characterized by a hollow centre and closed outer edge with openings at both ends of the tube.

[0013] The term "tubular rod composition" refers to a set of several rods of an undefined shape joined together, having the shape of a tube (the rods form the outer edge of the tube, leaving an empty middle of the tube).

[0014] The term "tubular blank" refers to a crystal blank formed in the form of a tube, which includes both a single and multi-piece tube shape and a tubular rod composition.

[0015] The term "volume of the levitating material" refers to a certain volume of levitating and molten material (in the liquid phase) placed in the EM levitation coil.

[0016] The term "material in the solid phase" refers to a material with a definite shape and volume below the melting point of the material in question, which is not in a gaseous or liquid state.

[0017] The term "solid-phase electrically conductive material" refers to an electrically conductive (specific electrical resistance at room temperature is within 10'8- 10'4Q*cm, e.g. Al, Cu, Fe) material that is below the melting point of the relevant material temperature (in the case of Al, below 660.3 °C) and is not in a gaseous or liquid state.

[0018] The term "solid-phase semiconductor material" denotes a semiconductor material (the specific electrical resistance at room temperature is in the range of 10'4- 108Q*cm, e.g. Si, Ge) which is below the melting temperature of the material in question (in the case of Ge, below 938.2 °C) and is not in a gaseous or liquid state.

[0019] The term "solid-phase electrical insulator" refers to the material of an electrical insulator (the specific electrical resistance at room temperature is in the range of 108- 1018Q*cm), which is below the melting point of the relevant material and is not in a gaseous or liquid state. Most glass, plastic and ceramic materials are electrical insulators.

[0020] The term "normal atmospheric conditions" refers to a region of space where the composition of the gas filling the space corresponds to the composition of the Earth's atmosphere (78.084% N2; 20.947 O2; 0.934% Ar; 0.035% CO2) and whose pressure corresponds to the pressure of the Earth's atmosphere near the sea level (97 - 104 kPa).

[0021] The term "special gas environment" refers to an area of space where the composition of the gas filling the space does not correspond to the composition of the Earth's atmosphere and / or the gas pressure does not correspond to the pressure of the Earth's atmosphere at sea level. This term includes reduced pressure (<97 kPa), elevated pressure (>104 kPa), as well as inert gas (e.g. He, Ar) or other gas atmospheres.

[0022] The essence of the invention is to implement a molten material replenishment system for the levitation (retention) zone, while simultaneously protecting the crystallization zone and the grown crystal from the influence of the EM field, which allows to control the temperature gradient in the crystallization zone and to use the crystal growing technique under levitation conditions for a wider range of materials.

[0023] Consequently, this technique allows protecting the crystallization zone and the grown crystal from the influence of the high-intensity EM field in the coil and optimizing the conditions of the crystallization process in the crystallization zone, while preserving the technological principles of shell-less melting. This, in turn, makes it possible to achieve the highest purity of the grown material (because the molten material does not come into contact with the walls of the containing shell / crucible), as well as to apply this technique at very high material melting temperatures, when the use of a shell / crucible is impossible or irrational.

[0024] Also, the technique allows growing crystals from levitating molten material. The size of the grown crystals and other structures is not limited by the volume of the levitating material. The technological principles of shell-less melting are preserved.

[0025] We propose to use electromagnetic levitation and realize the replenishment of molten, levitating material in the EM levitation coil from above, by forming the material to be added to the melt - a crystal blank in an arbitrary tubular shape or a tubular composition from rods, which are immersed from above into the molten material to compensate for material losses due to crystal growth. The crystal to be grown is located in the central part of the tubular blank and is drawn out of the molten material along the central part of the tubular blank. The arbitrary tubular shape or tubular composition of the crystal blank material protects the crystallization zone and the grown crystal from the high-intensity EM field, and reduces the temperature gradient in the crystallization zone. Since the lower part of the EM levitation coil, located on the other side of the direction of crystal growth and withdrawal, is not used for input or output of material, it is possible to implement additional coil windings under the molten material, which would significantly improve the stability of the volume of the levitating material close to the central axis of the coil, where its instability is greatest .

[0026] Brief description of drawingsFigure 1 shows a schematic side view of the proposed processA - crystal blank in tubular form; A’ - the inner part of the tubular blank; A” - the bottom part of the tubular blank; B - levitating material; B’ - top surface of the levitating material; C - crystallization zone; C’ - lowered EM field zone with reduced melt turbulence and reduced temperature gradient in the crystallization zone; D - rod of crystallized material; E - crystal seed; F - windings of the EM levitation coil; G - levitation zone; H - heating zone; P - the direction of the external force vector.Figure 2 is a top view of Figure 1 with two different configurations of the crystal blank - a tube and a tubular rod composition.A - crystal blank in tubular form; B - levitating material; D - rod of crystallized material; F - windings of the EM levitation coil; I - crystal blank (tubular rod composition).3. Figure 3 shows an example of a block diagram of the invention.A - crystal blank in tubular form; B - levitating material; D - rod of crystallized material; E - crystal seed; F - windings of the EM levitation coil; J - a push rod for holding and enabling the movement of the crystal blank; K - crystal seed holder with channel for cooling gas ; L - power source (max. power parameters - 20 kW, 850 A, 50 kHz).Figure 4 shows an example of an EM levitation coil.F’- top part of the EM levitation coil; F” - bottom part of the EM levitation coil.

[0027] The system (see fig. 1, 2) uses a crystal blank in shape of free-form tube (see. fig. 2, A) or tubular rod composition (see. fig. 2, I), with a function to feed the levitating volume of the molten material (see. fig. 1, 2, B), which is placed in the levitation zone (see. fig. 1, G), above the heating zone (see fig. 1, H). Crystal blank (see fig. 1, A) acts as a shield that protects the crystallization zone (see fig. 1, C) and the grown crystal (see fig. 1, 2, 3, D) from the EM field and the influence of disruptive effects caused by it. Crystal blank is inserted into the molten volume of the levitating material at a rate sufficient to compensate for its mass loss in the process of pulling out the growing crystal (the amount of mass supplied to the molten material per unit of time should be equal to the amount of mass removed during the crystal extraction process, the movement speeds of the crystal seed and the crystal blank may differ depending on the ratio of the cross-sectional areas of the seed and the blank). The levitation coil / inductor windings and counter-turn windings in the figures do not represent the actual geometrical configuration of the coil (see fig. 1, 2, 3, F).

[0028] The movement of the crystal blank is ensured by the holder rod (see fig. 3, J). The movement of the crystal seed / grown crystal is ensured by the push rod - crystal blank holder (see fig. 3, K). If the crystal growth process requires a special gas environment, the system or its parts can be placed in a chamber, which can be filled with the necessary gas and / or provide the necessary gas pressure if necessary. If the material is a semiconductor or electrical insulator and does not conduct electricity at ambient temperature, then the part of the crystal blank that is introduced into the levitation or holding area must be heated to a temperature at which the material begins to conduct electricity. This can be done, for example, with a laser or with focused infrared radiation, or with a flow of heated shielding gases.

[0029] The technique for growing crystals proposed in the invention comprising the following steps: a) Creation of volume of the levitating material in one of the following ways: i. maintaining the levitation of the material stored in the previous cycle in a molten state. ii. placing a solid phase material (with a certain shape and volume) in the levitation zone and melting it. The solid phase material blank can optionally be electrically conductive. The shape of the blank can be both a freely levitating volume of an undefined shape in the levitation zone, and a rod / s of an undefined shape partially inserted in the levitation zone.iii. heating a semiconductor or insulator blank in a solid phase (with a certain shape and volume) to an electrically conductive state (which can range from - 273 °C to 4500 °C for different materials), placing it in the levitation zone and melting it. The shape of the blank can be both a freely levitating volume of an undefined shape in the levitation zone, and a rod / s of an undefined shape partially inserted in the levitation zone. b) Ensuring the contact of the tubular blank with the volume of the levitating material in the following way: placing at least one crystal blank holder (see fig. 3, J) in a position so that the lower edge (see fig. 1, A”) of the crystal blank fixed in it (see fig. 1, 2, 3, A) is located in the levitation zone (see Fig. 1, G) of the levitation coil (see Fig. 1, 2, 3, F), and makes contact with the molten material. c) Placing the crystal seed holder (see fig. 3, K) in such a position, so that the crystal seed (see fig. 1, 3, E), which is fixed in the holder, contacts the top part (see fig. 1, B’) of the levitating material (see fig. 1, 3, B), inside the tubular blank (see fig. 1, A’) (During the previous or subsequent steps, stabilization of the temperature of the crystal seed with the flow of shielding gas can be realized in such a way as to ensure the temperature required for the crystallization of the given material, depending on the material used and the crystallization mode). d) Pulling the crystal seed (see fig. 1, 3, E) in the “top” direction and moving the crystal blank in the “bottom” direction. Pulling of the crystal seed (see fig. 1, 3, E) in the “top” direction, opposite the external force direction (see fig. 1, P) and moving the crystal blank (see fig. 1, 2, 3, A) in the “bottom” direction can occur simultaneously or alternately, at such rates that ensure the stability of the molten zone.The direction of gravity or external forces (see fig. 1, P) is used as a direction indication in the coil, which in weightless conditions can be replaced by other force vectors (e.g. light pressure, electrostatic force, etc.).Optionally, if the crystal seed (see fig. 1, E) and the crystal to be grown (see fig. 1, D) consist of the same chemical element (not counting impurities), then the crystal blank (see fig. 2, A or I) consists of the same chemical element. If the crystal to be grown consists of more than one chemical element, then the crystal blank may have the same chemical composition as the crystal to be grown, or it may consist of different materials whose chemical elements are included in the composition of the crystal to be grown.A brief description of the drawings:Fig. 1 Principal scheme.Fig. 2 Schematic representation of the process, top view.Fig. 3 Example of a system schematic.Fig. 4 An example of an electromagnetic levitation coil.Detailed description of the preferred embodiment (under Earth gravity conditions)

[0030] The crystal blank, (see fig. 1, 2, 3, A or I) with a help of reducers (not shown in the drawing) of the electric motor (EM483 is not shown in the drawing) of the corresponding push rod (see fig. 3, J), was placed in such a position, so that the bottom edge of the crystal blank (consisting of aluminium (Al), tube with outer diameter of 38±0,2 mm and inner diameter of 33±0,2 mm) (see fig. 3, A) would be placed in the levitation zone (see fig. 1, G) of the EM levitation coil (see fig. 3, F). The supplied current in the inductor (850 A, alternating current) (see fig. 4) ensured the heating of the crystal blank, its melting, and the creation of the volume of the levitating material. Stabilization of the crystal seed temperature with a chilled (- 100 °C) nitrogen gas flow (see fig. 3, M) was initiated to ensure that the temperature of the seed holder (see fig. 3, K) did not exceed 620±30 °C, which was assessed by a thermal imaging camera (OPTRIS). An alternating current (850±2 A, 46.2±0.1 kHz) was maintained from the power source (see fig. 3, L) to the windings (see fig. 3, F) of the levitation coil (see fig. 4). It was waited until the lower edge of the Al blank reached the melting temperature (melting point of Al is 660.3 °C) and began to melt. The molten material accumulated in the levitation zone and began to form the volume of the levitating material (see fig. 3, B). In the process of melting, the Al blank was gradually pushed into the levitation zone until the diameter of the volume of the levitating material exceeded the diameter of the Al blank (the diameter and height (depth) of the levitating volume were 48±5 mm and 20±5 mm, respectively).

[0031] The downward movement of the Al blank was maintained to ensure its contact with the bulk of the molten material.

[0032] The Al crystal seed holder (see fig. 3, K), with the help of the reducer (not shown in the drawing) of the corresponding electric motor (EM483, not shown in the drawing) and the push rod (not shown in the drawing), was placed in such position, so that the Al crystal seed (~2 mm diameter) (see fig. 1, 3, E) would be in contact with the top surface of the levitating volume, inside the tubular Al crystal blank. The holder (see fig. 3, K) of the Al crystal seed (see fig. 1, 3, E) was a rod with a vertical (parallel to the direction of the gravity vector) non -penetrating bore (see fig. 3, K’) and nozzles (see fig. 3, K”), which were designed for temperature stabilization of the crystal seed with a cooled nitrogen gas. In this step, the temperature stabilization of the crystal seed holder continues, it being kept between 600 °C and 650 °C.

[0033] The Al crystal seed was pulled up (at a speed of up to ~2-3 mm / min) while the crystal blank was pushed down (at a speed of up to -0.25 mm / min). The process of crystal growth is started - the melting Al blank feeds the levitating volume of material, from which the Al crystal grows upwards starting from the crystal seed.

[0034] In order to stop the crystal growth process, the feeding of the volume of the levitating material was first stopped - The movement of the Al blank was stopped. The movement of the Al crystal seed / growing structure was continued until the levitating material volume was exhausted and contact between the levitating material volume and the growing structure was lost.

[0035] The AC power to the levitation coil / inductor was turned off and the flow of gases was stopped. The molten material remaining in the levitating material volume, which had lost contact with the growing structure and the Al blank, poured out of the coil. The crystal growth process was over the grown structure could be removed from the holder. In a 15-min process, a -35-40 mm long and -10-12 mm wide crystal was obtained.References[1] Reuschel Konrad (1959). Floating zone melting method for semiconductor rods, U.S. Patent No. US3113841 A, Accessed at 20.08.2023 https: / / patents.google.com / patent / US3113841A[2] Donald M Wroughton, Okress Ernest Carl (1951). Magnetic levitation and heating of conductive materials, U.S. Patent No. US2686864A, Accessed at 20.08.2023 https: / / patents.google.com / patent / US2686864A[3] Janis Priede, Laurent Chrisptophe Bernard Baptiste, Gerardus Gleijm, Johannes Alphonsus Franciscus Maria Schade Van Westrum (2004). Apparatus and method for levitation of an amount of conductive material, Worldwide Patent No. W02006021245A1, Accessed at 20.08.2023 https: / / patents.google.com / patent / WQ2006021245Al[4] John H. Mortimer, (1985). Levitation heating using single variable frequency power supply, U.S. Patent No. US4578552A, Accessed at 20.08.2023 https: / / patents.google.com / patent / US4578552[5] Sergejs Spitans, Henrik Franz, Bjorn Sehring, Egon Bauer, Andreas Krieger (2018).Levitation melting process with mobile induction units, German Patent No. DE102018117300B3, Accessed at 20.08.2023 https: / / patents. google. com / patent / DE 102018117300B3[6] J. P. Witteveen (2021). Containerless metal single-crystal growth via electromagnetic levitation, University of Twente, PhD Thesis, Enschede.[7] Hans Nagorsen (1971). Apparatus for crystal growth in outer space, U.S. Patent No. US3999950A, Accessed at 20.08.2023 https: / / patents.google.com / patent / US3999950A[8] T. Okumura, K. Yamamoto, M. Shibata (2009). Large Scale Cold Crucible Levitation Melting Furnace with Bottom Tapping Nozzle. Proc. Of 6th Internal. Conf. Electromagnetic Processing Materials, Dresden, Germany, pp. 521-524.

Claims

Claims1. A technique for growing crystals comprising the following steps: a) creating of a volume of levitating material (B) by melting a crystal blank in the solid phase placed in the levitation zone, or by placing an already melted volume of material in the levitation zone; b) bringing the tubular crystal blank (A or I) into contact with the volume of levitating material (B), which includes placing at least one crystal blank holder (J) in a position so that the lower edge (A”) of the tubular crystal blank (A) secured therein would be in the levitation zone (G) of the coil (F) and would be making contact with the molten material; c) placing the crystal seed holder (K) in a position so that the crystal seed (E) fixed in it comes into contact with the upper surface (B') of the levitating material (B) inside the tubular blank (A'); d) pulling the crystal seed (E) up against the direction of the external forces (P) and pushing the crystal blank (A) down in the direction of the external forces (P).

2. The technique according to claim 1, where in step a) the material blank in the solid phase is electrically conductive.

3. The technique according to claim 1, where in step a) the material blank in the solid phase is semiconductor or an electric insulator.

4. The technique according to claim 1, where in step d) pulling the crystal seed (E) up and moving the blank (A) down takes place simultaneously.

5. The technique according to claims 1 to 4, wherein the crystal growth takes place under normal atmospheric conditions.

6. The technique according to claims 1 to 4, where crystal growth takes place in a special gas environment.

7. The technique according to claims 1 to 6, wherein the crystal seed (E) is metallic.

8. The technique according to claims 1 to 6, in which the crystal seed (E) is a semiconductor or an electrical insulator.

9. The technique according to claims 1 to 6, wherein the crystal seed (E) is any solid state structure.

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