Device for growing single crystals from melt

 

The invention relates to a device for the cultivation of large volumetric shaped single crystals from the melt, for example, sapphire methods Czochralski, kyropoulos. The inventive device for growing single crystals from the melt to the seed crystal includes a cylindrical chamber with a lid, heat the node, the crucible to melt structurally mounted on the shaft for rotation and vertical movement. Luggage made two and the mechanism of vertical movement of the sections, thermal unit is installed between the upper and lower sections of the camera and is made in the form of a hollow water-cooled cylinder placed inside the heater collected from the curved shape of the inner surface of the crucible U-shaped blades, and closed annular water-cooled current leads, a cylinder mounted on the secondary shaft, located on the outer surface of the cylinder and provided with a mechanism for moving the cylinder vertically and around the rod, the inner side of the cylinder in the lower part thereof is made with the tabs, which are insulators, the current leads are made with holes, in which is secured the free ends of the slats, and U on entirely heater, and their findings are located on the lateral surface of the cylinder in different horizontal planes, a heater installed inside the crucible, the dimensions of the crucible and heater satisfy the relation dkr2dload-dcrucible. The device allows to increase the perfection of the structure and to ensure uniformity in size along the length of the single crystal, to increase the productivity by increasing the size of the load, to reduce energy consumption and to reduce the consumption of starting material due to the full sample of the melt for growing a single crystal and to increase the service life of the tungsten crucible and heater. 5 C.p. f-crystals, 3 ill.

The invention relates to a device for growing single crystals from the melt to the seed crystal and can be used in the technology of growing crystals, such as sapphire, methods Czochralski, kyropoulos.

The technical problem solved by the invention is a device for growing large volume shaped single crystals from the melt in a uniform thermal field, simplifying the design and operation of thermal unit and heater, in particular, as well as providing a hundred is about the perfection of the crystals.

A device for growing monocrystalline ribbons sapphire, which includes a camera located inside the crucible, thermal unit, the shaper, structurally mounted on a rod.

Thermal unit made in the form of cylindrical graphite heater, the inner surface of which is coated with a layer of silicon carbide, and screens.

The crucible to melt coated on the external side with a layer of tungsten. The crucible is mounted on a pedestal and placed inside a graphite heater. Screens placed above the crucible (see ed.St. The USSR 1213781, publ. 23.04.1991, With 30 In 15/34).

The device has the following disadvantages.

The material of the heater - graphite with a deposited layer of silicon carbide, chemically reacts with corrosive oxides of aluminum at high temperatures, which dramatically reduces the life of the heater and pollutes the carbon of the growing crystal. The heater cannot be repaired in the event of a breakdown. Thermal unit cannot provide a rectangular radial isotherms necessary to obtain high-quality surround shaped single crystals.

The device cannot be used for growing large crystals.

A device for in the eat-shaper and thermal unit, containing situated coaxially to the crucible with a gap of a graphite heater in the form of a Cup with a front opening at the level of the end face of the shaper and with the increasing cross section of the hole towards the bottom, and the screen in the form of a hollow cylinder mounted above the crucible with tie rods attached to the upper block insulation. The heater is connected to the current source (see ed. St. USSR 1592414, publ. 15.09.90, WITH 30 IN 15/34).

The device is designed for the sapphire tube and cannot be used for growing high-quality bulk single crystals.

A device for growing bulk single crystals, including the camera, two melting heater and the double-crucible. In the upper section of the melted source material using one heater located around the upper section of the crucible, and the cultivation is carried out on the lower section of the crucible using a different heater installed under the bottom section of the crucible (see ed. St. 661966, publ. 30.03.80, WITH 30 IN 15/02). The unit is adopted for the prototype.

The device cannot be used for growing bulk shaped single crystals, due to the impossibility of creating in the radial melt isotherm different geometry.

The technical result is army and structural perfection due to the permanence of form radial isotherms and small temperature gradients in the melt, as well as ease of operation and ergonomics of thermal node and a heater, in particular.

The technical result is achieved in that a device for growing single crystals from the melt to the seed crystal, comprising a cylindrical chamber with a lid, heat the node, the crucible to melt structurally mounted on the shaft for rotation and vertical movement, according to the invention the chamber is two and the mechanism of vertical movement of the sections, thermal unit is installed between the upper and lower sections of the camera and is made in the form of a hollow water-cooled cylinder placed inside the heater collected from the curved shape of the inner surface of the crucible U-shaped blades, and closed annular water-cooled current leads, the cylinder is fixed on the secondary shaft, located on the outer surface of the cylinder and provided with a mechanism for moving the cylinder vertically and around the rod, the inner side of the cylinder in the lower part thereof is made with the tabs, which are insulators, the current leads are made with holes, in which are secured the free ends of the blades, and U-shaped curved ends of slats secured to the us on the side surface of the cylinder in different horizontal planes, the heater is installed inside of the crucible, the dimensions of the crucible and heater satisfy the relation dkr2dload.-dcrucible.

The current leads are either coaxial or one above the other.

The slats are made of the same length and configuration and assembled in a circle or in sections, the number of lamellae in the heater and hole current in multiples of 12. To create a radial isotherms polygonal shapes, the length of the sections of the blades and their locations correspond to the lengths of sides of the polygon.

The diameter of the hollow cylinder is equal to the diameters of the sections of the camera.

Centering ring, tightening curved U-shaped ends of the slats, is not involved in the electric circuit.

The essence of the claimed device is a new design thermal unit in which all the elements, namely: the heater, the current leads, insulators, suspension cylinder is made compact and represent a single whole.

The new design of the device is installing a heater inside the crucible and adherence to the stated ratio of the diameter of the crucible, the heater and the diameter of the grown crystal. The crucible in this case is the holder of the melt and the screen heater. Provides vozmojnos overheating of the melt, consequently, the occurrence of bubbles in it. This has a positive effect on the structure of the grown single crystal and the energy consumption per unit of production.

Design thermal unit also has a number of advantages.

The heater is assembled from strips, mounted on the closed annular current and centring ring at the same time performs the function of a thermal shaper, has the ability to change the shape of the radial isotherms and to determine the profile shape of the grown crystals. The heater is simple in operation, can be easily assembled and disassembled when changing profile of the single crystal, so that changing forms radial isotherm is achieved by removing or adding the desired number of slats in sections. The initial number of blades and the number of holes in tokiwadai a multiple of 12.

Hollow water-cooled cylinder also serves several functions. He, forming the middle section of the camera, at the same time holds the current leads with slats heater and also creates a symmetric thermal field relative to the vertical axis of the camera by centering heater as by insulators based on internal projections of the cylinder, and due to the possibility of horizontal perfection of forms and crystal structure.

In addition, the execution of the cylinder with the possibility of vertical movement and movement about the axis of the shaft on which the cylinder is fixed, provides easy access to the heater and the replacement of elements of thermal unit, and also to the cavities of the upper and lower sections of the chamber.

In General, thermal unit design significantly increases the period of its operation, ergonomic and does not require the consumption of expensive graphite, polluting the single crystal and not subject to recovery.

The location of the heater inside the crucible makes it possible to grow large single crystals. Possibility by changing the number of fins and their location in the current leads to obtain not only round, but also a polygonal shape radial isotherms allow in combination with other essential features to grow large volume shaped sapphire crystal with a high degree of perfection of the structure and a given size along the entire length of the single crystal.

The stated ratio of the diameters of the crystal, the crucible and the heater provides the greatest performance of the device and the full sample of the melt, as in this case, is the required condition that the temperature at timisoreana in Fig.1.

The device includes upper 1 and lower 2 sections cameras, made with a mechanism for moving in the vertical direction (in Fig. 1 not shown), with cover 3, strukturdaten 4, the crucible 5, made for example of tungsten and installed in the lower section of the 2 cameras, the top rod 6 for fastening structurally 4, the lower rod 7 for mounting the crucible 5. The rods 6 and 7 are rotatably. Between the upper section 1 and the lower section 2 cameras installed thermal unit in the form of a hollow water-cooled cylinder 8. Inside the cylinder 8 is placed a heater 9, assembled from curved shape of the inner surface of the crucible U-shaped slats 10, made of refractory metals and alloys, such as tungsten, and a closed annular water-cooled current leads 11, 12. The current leads 11, 12, one above the other or coaxial (not shown), have holes 13, in which is fixed the upper ends of the U-shaped slats 10. The lower bent U-shaped ends of the slats 10 fixed centering their ring 14, is not involved in the electric circuit of the heater 9.

The cylinder 8 is fixed on the secondary shaft 15, which is located on the outer side of the cylinder 8 and is equipped with a transfer mechanism (Fig.2 is not shown) Qili the protrusions 16.

The current leads 11, 12 mounted on the protrusions 16 in the insulator 17, which center and the current leads 11, 12 and the heater 9.

On the lateral surface of the cylinder 8 in different horizontal planes placed conclusions 18, 19 current leads 11, 12. The heater 9 is placed within the crucible 5.

Device for growing single crystals from the melt to the seed crystal is as follows.

Collect thermal unit. For this purpose water-cooled cylinder 8 mounted on the rod 15 and deployed on the 90orelative to the vertical axis of the camera (see Fig.2) install centering on the insulators 17 water-cooled current leads 11, 12.

For growing shaped bulk single crystals, for example, a rectangular shape (Fig.3 (a,b,C)) into the holes 13 of the ring current leads 11, 12 installing U-shaped slats 10, collected in the section, the length of which corresponds to the lengths of the sides of the given rectangle. The upper ends of the slats 10 are fixed in the holes 13 of the current leads 11, 12, and the lower bent U-shaped ends of the centring ring 14 that is not part of the electrical circuit of the heater.

Such thermal unit deploying on the 90oand combine with the vertical axis of the camera, and hermetically connected to the l with heater. On the top rod 6 set the crystal in the form of four-sided prisms, one of the side faces which are oriented in accordance with sections slats 10, creating a rectangular radial isotherm for crystal growth of a rectangular shape with a natural cut.

The upper section 1 is hermetically connected to thermal node, a heater 9 and carry out the process of growing single crystals by the Czochralski obtaining crystals of rectangular shape.

Were grown single crystals of sapphire, round shape with a diameter of 200 mm and a square shape of size 150x150 mm perfect structure without deviation in size along the length of the crystals.

The device allows to obtain the following positive effects.

1. The possibility of growing large-size shaped single crystals.

2. To increase the perfection of the structure and to ensure uniformity in size along the length of the single crystal.

3. Increase productivity by increasing batch sizes.

4. To reduce the power consumption.

5. To reduce the consumption of starting material due to the full sample of the melt for growing a single crystal.

6. To increase the service life of the tungsten crucible and heater.

3. Device according to any one of paragraphs.1 and 2, characterized in that the slats are made of the same length and configuration.

4. Device according to any one of paragraphs.1-3, characterized in that the number of lamellae in the heater and the hole current in multiples of 12.

5. Device according to any one of paragraphs.1-4, characterized in that for radial isotherms polygonal forms lamellae are collected in section, whose length and location correspond to the sides of the polygon.

6. Device according to any one of paragraphs.1-5, characterized in that the diameter of the hollow cylinder is equal to the diameters of the sections of the camera.

 

Same patents:

The invention relates to devices for growing shaped single crystals from the melt to the seed crystal, such as sapphire, methods Czochralski, kyropoulos

The invention relates to a method and apparatus for growing a single crystal of high quality

The invention relates to the technology of growing single crystals from solutions, melts and can be used in obtaining single crystals of lithium ferrospinel LiFe5O8for devices based on magnetic excitations

The invention relates to the field of production of semiconductor materials
The invention relates to a technology of inorganic scintillators for detector of ionizing radiation, mainly "thermal" neutrons, soft gamma-ray and low-path of charged particles

The invention relates to devices for growing shaped single crystals from the melt to the seed crystal, such as sapphire, methods Czochralski, kyropoulos

The invention relates to techniques for growing shaped crystal pulling from the melt with rotation using formers and can be used to produce monocrystalline tubes and rods with periodically varying impurity content along the length of the crystal

The invention relates to a crystal growth of a given shape from the melt, in particular crystal refractory compounds, such as sapphire, ruby, allmaturewoman pomegranate, etc. that can be used in instrumentation, electronic and chemical industry

The invention relates to techniques for growing shaped crystals of refractory oxides for components and products

The invention relates to the field of production of semiconductor materials and can be used to produce silicon in the form of plates floating method

The invention relates to techniques for growing shaped crystals from the melt with variable cross-sectional shape
The invention relates to techniques for growing shaped crystals from the melt with variable cross-sectional shape

The invention relates to a process for the production of single-crystal materials used in various branches of national economy

The invention relates to the turbines, in particular the production of parts for gas turbine engines directional solidification and can be used in the optical industry, semiconductor engineering and chemical technology

The invention relates to crystal growth by pulling from a melt on a seed crystal and can be used in installations for the manufacture shaped polycrystalline and monocrystalline products from various kristallizuetsya materials, metal alloys, semiconductors, insulators

The invention relates to devices for growing shaped single crystals from the melt to the seed crystal, such as sapphire, methods Czochralski, kyropoulos

The invention relates to crystallography

The invention relates to the field of cultivation of optical single crystals by the Czochralski method

The invention relates to the field of cultivation of optical single crystals by the Czochralski method

The invention relates to single crystal growth, in particular to the stage of preliminary preparation of solution-melts or melts, i.e
Up!