32results about How to "Increased axial temperature gradient" patented technology

The invention provides hot-cold combined casting mould horizontal continuous casting equipment of cupronickel tubing and a technology thereof. The equipment comprises a smelting system for melting metal, a heat insulation system for storing molten metal, a horizontal continuous casting system for casting and shaping and an auxiliary system, wherein in the continuous casting system, the front end of a cold shaping section is provided with a hot shaping section so as to effectively control the solid-liquid interface of a tube billet to be located near the juncture of a cold section and a hot section; a shorter water-cooling copper bush and electromagnetic induction heating are adopted to reasonably design coil structure and the power and the frequency of a heating power supply, reduce electromagnetic constraint force to balance the hydrostatic pressure of a metal fusant, reduce friction between a primary kish and the casting mould, improve the surface quality of the tube billet and prolong the service life of the casting mould. Thus, the inner surface and the outer surface of the tube billet manufactured by the invention have good quality and no defects of orange peel, wrinkles, cracks and the like, net shape continuous casting is realized, the production efficiency and the metal yield are improved and the production cost is obviously lowered.

The invention discloses a high-speed single crystal growth device and method and mainly relates to a crystal cooling manner and a reaction cylinder for conveying reactants to perform chemical reactions. The reaction cylinder is made of high-temperature-resistant materials and comprises a gas inlet cylinder and a gas discharge cylinder. The gas inlet cylinder is provided with a passage for feeding the reactants and protecting gas. The reactants are sprayed to the surfaces of growing high-temperature crystals after passing the gas inlet cylinder to perform chemical reaction so as to absorb heat and fast remove the heat on the surfaces of the crystals. The gas discharge cylinder is used for discharging the reactants not completely reacted and reaction product gas out of a furnace. The gas inlet cylinder and the gas discharge cylinder are integrally connected and fixed on a furnace wall. The high-speed single crystal growth device and method has the advantages that the chemical heat-absorption reaction is applied to the intensified cooling in crystal growth for the first time, the heat on the surfaces of the crystals can be removed fast, the axial temperature gradient inside the crystals can be increased evidently, and accordingly the crystal growth speed is increased.

The invention discloses a vertical Bridgman growth furnace. From the bottom up, the inside of an outer shell of the furnace is provided with a thermal insulating board, two groups of I type heating modules, a cooling fin, a group of II type heating modules, two groups of I-type heating modules and a furnace hearth cover. The center hole of the thermal insulating board is filled with fireproof ceramic cotton, and the center of five sections of heating modules is provided with two sections of liner tubes which are separated by the cooling fin, and the outside of the joint of the liner tubes is provided with a liner sleeve, and the surrounding of the center hole of each group of heating modules is provided with an electric heated wire of each separate temperature control system, and a Pt / PtRh10 thermocouple is arranged in the radical direction, being in the middle of the outer wall which is vertical to the outer wall of each group of modules, and the temperature measuring contact of the thermocouple is close to the outer wall of the liner tube 5. The invention also discloses the optimization method of the temperature field of the vertical Bridgman growth furnace. As the vertical Bridgman growth furnace adopts the design of five sections of modules, adjustable temperature field for growing various crystals can be obtained by changing different modules, thus solving the problem of constitutional super cooling caused by small axial temperature gradient.

The present invention provides a semiconductor crystal growth device, which comprises: a furnace body; a crucible arranged inside the furnace body to accommodate silicon melt; a pulling device arranged in the The top of the furnace body is used to pull out silicon crystal rods from the silicon melt; and a heat shield device, the heat shield device includes a draft tube, and the draft tube is barrel-shaped and wraps around the silicon crystal Rods are arranged around to rectify the argon gas input from the top of the furnace body and adjust the thermal field distribution between the silicon crystal rods and the silicon melt level; wherein, the heat shield device also includes The adjustment device arranged inside the lower end of the draft tube is used to adjust the minimum distance between the heat shield device and the silicon crystal rod. According to the present invention, by setting the adjustment device inside the lower end of the draft tube, the distance between the silicon crystal rod and the device close to the heat shield can be adjusted without changing the shape and position of the draft tube, thereby improving the crystal growth speed and quality.

The invention discloses a micro-downward pulling crystal growth furnace, which comprises an upper heat insulation layer and a bottom heat insulation layer (13) arranged from top to bottom, and an observation hole (4) is arranged in the bottom heat insulation layer (13) for observation The hole (4) is tubular, and the included angle between its central axis and the normal to the top surface of the bottom insulation layer (13) is 45° to 60°; the inner layer insulation layer, the middle insulation layer and the bottom insulation layer (13) are all composed of mass Zirconia and alumina with a ratio of 1:9 are pressed and calcined. The observation window provided by the invention can observe the crystal growth condition at the crystal growth interface in time; moreover, the observation window has little influence on the temperature field of the crystal growth furnace, and can further improve the yield of crystal growth.

The invention discloses a single crystal furnace for achieving rapid crystal growth through a chemical heat sink enhanced cooling technology and mainly relates to a reaction device capable of conveying reactants and carrying out a chemical endothermic reaction inside the device. The reaction device is composed of a graphite cylinder and a reaction cylinder, wherein the reaction cylinder is made of an inert material; the reactants are introduced from an inlet, the chemical endothermic reaction is carried out in the reaction cylinder at a high temperature, the temperature on the surface of the reaction device and in a nearby argon gas area thereof is reduced, heat on the crystal surface is rapidly transferred, and incompletely reacted reactants and the reaction product are discharged out of the furnace by an outlet. The single crystal furnace is reasonable in structural design, the reactants can react in the reaction device, and impurities can be prevented from being introduced into the furnace in the reaction process. According to the device disclosed by the invention, the growing crystal is subjected to enhanced cooling by virtue of the chemical endothermic reaction, the heat on the crystal surface is rapidly transferred, and the axial temperature gradient inside the crystal is obviously improved, so that the crystal growth speed is improved, and the aim of reducing the crystal preparation cost is achieved.

The invention discloses a high-quality silicon carbide single crystal, and a substrate and an efficient preparation method thereof, and belongs to the field of semiconductor materials. The preparationmethod comprises the following steps: putting raw materials and seed crystals into a crucible, assembling the crucible and a heat preservation structure into a crystal growth furnace, arranging a heating coil assembly at the periphery of the side wall of the crystal growth furnace, and mounting an adjusting mechanism; removing impurities; and growing the crystal, wherein the heating coil assemblycomprises a first coil assembly arranged corresponding to a raw material area and a second coil assembly arranged corresponding to a crystal growth area, and the inner diameter of the second coil assembly is increased in the direction from raw materials to seed crystals. The preparation method of the silicon carbide single crystal is characterized in that the axial temperature gradient in a growth cavity is formed, so the high-quality silicon carbide single crystal can be prepared; the radial temperature gradient in the growth cavity for growing the single crystal is adjusted, so the crystalgrowth rate and the crystal growth quality are improved; and the radial temperature gradient is reduced, and a certain axial temperature gradient can be ensured, so the high-quality silicon carbide single crystal can be efficiently prepared.

The application discloses a silicon carbide single crystal, a substrate and a preparation method thereof, belonging to the field of semiconductor materials. The silicon carbide single crystal preparation method comprises that the temperature measuring hole formed by the upper insulation layer group outside the crucible forms a low-temperature zone and a high-temperature zone in the crucible, and the raw material in the high-temperature zone is gas-phase transported to the surface of the seed crystal in the low-temperature zone by using a physical gas phase transport method. Carry out crystal growth; the upper insulation layer group includes the second insulation layer and the first insulation layer arranged in sequence along the direction of the raw material from the seed crystal, the first insulation layer is provided with the first opening, the second insulation layer is provided with the second opening, and the rotation adjustment mechanism Rotate the first insulation layer and / or the second insulation layer to adjust the cross-sectional area of ​​the temperature measuring hole formed by the first opening and the second opening, thereby adjusting the axial and radial temperature gradients in the crucible during the crystal growth process. The silicon carbide single crystal preparation method can not only adjust the radial temperature gradient in the growth chamber for growing single crystals; but also ensure a certain axial temperature gradient while reducing the radial temperature gradient, and produce high-quality silicon carbide single crystals with high efficiency. crystal.

The present application discloses a high-quality silicon carbide crystal and a growth method and device thereof, which include the following steps: 1) assembling: after installing a seed crystal unit in a crucible filled with raw materials, move it into a closed accommodating cavity; 2) long Crystal stage: control the crystal growth conditions in the accommodating cavity, adjust the temperature of the first cooling water to 8-16 ℃, and the flow rate to 18-54 mL / s, that is, to obtain the crystal; wherein, the accommodating cavity is composed of An assembly of cooling jackets is formed, the cooling jackets include a first cooling pipe and a second cooling pipe, the first cooling pipe being sleeved inside the second cooling pipe and cooperating to form a connection for passage into the second cooling pipe. A first interlayer of cooling water, the thickness of the first interlayer linearly increases along the direction from the bottom of the crucible to the opening. The crystal growth method can realize the controllable axial temperature gradient inside the crucible, thereby controlling the growth quality and growth rate of the crystal; at the same time, the axial temperature gradient formed in the crucible is more stable, which can further ensure the crystal growth quality.

The invention provides a preparation method and a growth device of an N-type silicon carbide crystal, the method comprising: (1) placing a raw material in a high temperature zone of a crucible, placing a seed crystal in a low temperature zone of the crucible, and the top outer wall of the crucible facing inward An annular gas groove is formed by the depression; the assembled crucible is placed in the furnace body of the crystal growth furnace, so that the annular air groove is close to the ventilation hole of the furnace body; (2) in the crystal growth stage, the air is passed into the furnace body through the ventilation hole Nitrogen source gas, controlling the growth temperature and pressure, and growing N-type silicon carbide crystals on the seed crystals. Through the annular air groove close to the vent hole of the furnace body, the incoming gas can flow along the annular air groove, the air flow rate is fast, and the gas diffuses into the crucible, so that the heat transfer in the crucible away from the central axis is accelerated, reducing the number of crucibles. The radial temperature gradient improves the quality of crystal growth.