Device for growing single crystals of sapphire

 

The invention relates to the field of growing single crystals from the melt and can be used to create a device for growing single crystals of sapphire. The invention consists in that the device for growing single crystals of sapphire, containing installed in a vacuum chamber screens, heater, structurally with fixed therein by the seed crystal, the crucible with the lid and the shaper, the speed regulation system of lifting the seed crystal and the power of the heater, on the cover of the camera fortified bunker, made in the form of a cylinder with a conical top and bottom, the volume of the cylinder is equal to the volume of the crucible, the lower part contains the shut-off valve in the form of a truncated cone, the upper part of the hopper has a bellows, which is connected with the shut-off valve with stem, with manual or automatic movement, the lower part of the hopper tightly inserted into the tube for supplying the source of powder material, is lowered into the crucible through the hole in the lid of the crucible. The lower end of the tube is located below the edge of the crucible at a depth corresponding 0,20-0,25 height of the crucible, and the distance between the axes of the tube and crucible faced scoobysnack alumina alpha-modification in the form of powder, reduction of energy consumption for melting of raw materials and increase productivity by increasing the volume of the melt in the same process. 1 Il.

The invention relates to the field of growing single crystals from the melt by the method of directional solidification and can be used to create a device for growing single crystals of sapphire.

The technical problem solved by the invention is to reduce the cost of the obtained crystals, mainly used in optoelectronics.

A device for growing single crystals based on complex oxides, for example, for growing alyumoittrievy garnets. The device is a sealed chamber in which is installed a rod with attached seed with the possibility of vertical movement and rotation, water-cooled coil connected to a source of induction heating, water-cooled bottom, made in the form of a spiral, the crucible, made with a hole at the bottom and fixed inside the inductor in a stationary position, the boot device in the form of a sealed hopper feeder with mixture and feeding tube. The internal volume ti is via the bottom hole of the additional amount, formed by the gap between the crucible and the coil. Originally are loaded crucible and extra volume and melt the charge. In the growth process are yoshitoku through feed tube in additional volume from which the resulting melt is fed into the crucible through the bottom hole. This device cannot be used to obtain single crystals of sapphire due to the high content of impurities. In addition, the powdery raw materials for alyumoittrievy garnet is a coarse (granulated) product. (A. C. 904347, With 30 15/12, publ. 1993)

A device for growing single crystals of sapphire, containing installed in a vacuum chamber screens, heater, crucible former, structurally with fixed therein by the seed crystal sapphire, the speed regulation system of lifting the seed crystal and the power of the heater. (Eurasian patent 003419, With 30 In 17/00, 29/20, 2002)

This device provides for the loading of raw materials before the start of the process, and is used as raw material lump waste production Vernal. Other types of source materials, for example, powdered, cannot be recycled in this device. Melting Kus is ri filling of the crucible. In addition, lump waste production Vernell have considerable value.

Currently, the sapphires are not only used in microelectronics, demanding high crystallographic characteristics, but also in other areas where particular importance is the cost of the product. The technical result of the invention is the possibility of processing cheap powdered aluminum oxide, alpha-modification in the form of powder, the reduction of energy consumption for melting of raw materials and increase productivity by increasing the volume of the melt in the same process.

The technical result is achieved in that a device for growing single crystals of sapphire, containing installed in a vacuum chamber screens, heater, structurally with fixed therein by the seed crystal, the crucible with the lid and the shaper, the speed regulation system of lifting the seed crystal and the power of the heater according to the invention on the cover of the camera fortified bunker, made in the form of a cylinder with a conical top and bottom, the volume of the cylinder is equal to the volume of the crucible, the lower part contains the shut-off valve in the form of a truncated cone, the top h is m manual or automatic movement, the lower part of the hopper tightly inserted into the tube for supplying the source of powder material, is lowered into the crucible through the hole in the lid of the crucible, and also that the lower end of the tube is located below the edge of the crucible at a depth corresponding 0,20-0,25 height of the crucible, and the distance between the axes of the tube and the crucible is 0.20-0.30 diameter of the crucible.

The essence of the invention lies in the fact that the proposed new constructive execution of the boot node device for growing single crystals and new mutual arrangement of its elements, namely the location of the boot tube height, and the diameter of the crucible. The declared design of the boot node to use as the source of previously unused raw material powder of aluminum oxide, to make uploading of the crucible in the melting process with maximum adaptability operations (no dusting, increase the speed and uniformity of the deposition rate, the maximum filling volume of the crucible and the reduction of time for this operation).

Powder of aluminum oxide, alpha-modification get in the evaporation process alemannisch alum (AAC).

The deviation from the declared parameters of the placement of the tube increases lie is.

The claimed device is shown schematically in the drawing.

The device comprises a vacuum chamber 1 with a cover 2 placed inside the chamber 1 by the heater 3, the upper and lower screens 4, the speed regulation system of lifting the seed crystal and the power of the heater (not shown), the crucible 5 with a cylindrical shaper 6 and the cover 7. On the cover 2 of the camera 1 is installed strukturdaten 8, the hopper 9, provided with a shut-off valve 10, the bellows 11 and the tube 12 for filling the source material using a rod 13 in the crucible 5.

The operation of the device is as follows. In the camera 1 with a cover 2 place the heater 3, the upper and lower screens 4, the speed regulation system of lifting the seed crystal and the power of the heater (not shown), the crucible 5 with a cylindrical shaper 6 and a cap 7. Loaded into the crucible 5 original product in the form ofcrystals of aluminum oxide, for example, obtained by the method of Verneuil, in an amount not more than 10 weight% plan download, install strukturdaten 8 with the seed crystal.

In mounted on the cover 2 of the camera 1, the hopper 9, provided with a shut-off valve 10 and the bellows 11, sleep powder Al10^-5mm RT. Art.) the original product, pre-loaded on the bottom of the crucible 5 is melted with the heater 3. Subsequent portions of the melt is produced by a continuous or batch adding the powder from the hopper 9 through the tube 12 by means of the stop valve 10 and shaft 13, provided with a mechanism for automatic or manual movement (not shown). Since the specific weight of the final product - sapphire crystal - is 4 g/cm³and melt 3 g/cm³then cover 7 mounted on the crucible 5, does not impede the growth of the crystal in the volume of the crucible, as the latter when the melt in the solid phase remains unfilled by approximately 30%.

Since the hopper 9 and the camera 1 connected single vacuum space, which is provided with the bellows 11, the process of adding the powder in the crucible does not happen of its dust, which is typical for processes with the use of powdered raw materials, especially under vacuum conditions. Power consumption for melting is minimized, as in this case, almost no voids (gaps) between the particles of the original product. The powder fed from the hopper 9 to be synchronized with the speed of transition of the powder into the melt. The cultivation techniques after melting all of the original product are standard.

In the inventive device the grown single crystal weighing 12 kg with characteristics to meet the requirements of optoelectronics, and yield not lower than 50%. Through the use of cheap raw materials cost of the obtained crystal is reduced by at least 20%. In addition, further cost reduction is achieved by reducing energy consumption at the stage of fusion of about 15%. Thus, the claimed invention allows to provide:

- involved in the production of single crystals of sapphire are practically not used in the past cheap powdered aluminum oxide;

- significant reduction in the cost of the obtained crystals through the use of cheap material in an amount of not less than 90% of the required;

- lower energy process at the stage of obtaining the melt while maintaining rates in the yield.

Claims

Device for growing single crystals of sapphire, containing installed in a vacuum chamber screens, heater, structurally with fixed therein seed Chris is and the power of the heater, characterized in that on the cover of the camera fortified bunker, made in the form of a cylinder with a conical top and bottom portions, the volume of the cylinder is equal to the volume of the crucible, the lower part contains the shut-off valve in the form of a truncated cone, the upper part of the hopper has a bellows, which is connected with the shut-off valve with stem, with manual or automatic movement, the lower part of the hopper tightly inserted into the tube for supplying the source of powder material, is lowered into the crucible through the hole in the lid of the crucible, the lower end of the tube is located below the edge of the crucible at a depth, the corresponding 0,20-0,25 height of the crucible, and the distance between the axes of the tube and the crucible is 0.20-0.30 diameter of the crucible.