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CN-122013307-A - Resistance method growth equipment and method for large-size silicon carbide single crystal

CN122013307ACN 122013307 ACN122013307 ACN 122013307ACN-122013307-A

Abstract

The invention discloses resistance method growth equipment and a resistance method for large-size silicon carbide single crystals, and relates to the technical field of silicon single crystal preparation, wherein the resistance method growth equipment comprises an inert gas inlet mechanism, the inert gas inlet mechanism comprises an integrated bottom plate, the top of the integrated bottom plate is fixedly connected with a fixed ring, and the inside of the fixed ring is fixedly connected with an inert gas cylinder; the heating mechanism comprises an insulation box body, and a vacuum cavity is arranged at the upper end of the insulation box body. According to the invention, through the design of the guide cylinder combining the spiral guide groove and the cooling cavity, the cooling flow channel in the mounting frame is matched, so that the transmission path of the gas phase substance can be optimized, the residence time of the gas phase substance in the guide cylinder is prolonged, the gas phase molecules are distributed more uniformly, the growth quality difference between the edge and the central area of the crystal is obviously reduced, meanwhile, the pressure is quickly increased to 500-800mbar in the ultrahigh-pressure quick growth stage, the collision frequency of the gas phase molecules is greatly increased, the growth rate is obviously increased compared with that of the traditional process, and the market demand for productivity is met.

Inventors

  • HU JIURONG

Assignees

  • 嘉兴南湖学院
  • 中科超芯(浙江)新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260311

Claims (10)

  1. 1. A resistance method growth device for large-size silicon carbide single crystal is characterized by comprising The inert gas feeding mechanism comprises an integrated bottom plate (11), a fixed ring (12) is fixedly connected to the top of the integrated bottom plate (11), and an inert gas cylinder (13) is fixedly connected to the inside of the fixed ring (12); The heating mechanism comprises an insulation box body (21), a vacuum cavity (22) is formed in the upper end of the insulation box body (21), a graphite heating piece (23) is fixedly connected to the inner wall of the vacuum cavity (22), and a box cover (24) is arranged at the top of the insulation box body (21); The large-size silicon single crystal growth mechanism comprises an air cylinder (31), wherein the bottom of the air cylinder (31) is fixedly connected with the inner wall of the lower end of the heat insulation box body (21), the output end of the air cylinder (31) is fixedly connected with a supporting piece (32), and the top of the supporting piece (32) is fixedly connected with a crucible tray (33); Multistage evacuating mechanism, multistage evacuating mechanism includes exhaust tube (41), the inside of exhaust tube (41) is provided with first check valve (42), the one end of exhaust tube (41) is provided with first vacuum pump (43), the output of first vacuum pump (43) is provided with output tube (44).
  2. 2. The apparatus for the resistive growth of large-sized silicon carbide single crystals as set forth in claim 1, wherein the inert gas introduction mechanism further comprises a gas pipe (14), and an electromagnetic valve (15) is provided inside the gas pipe (14).
  3. 3. The resistive growth apparatus of large-size silicon carbide single crystal according to claim 1, wherein the heating mechanism further comprises an observation window (25), the observation window (25) is arranged on the surface of the case cover (24), a first mounting rod (27) is fixedly connected to the bottom of the inner cavity of the vacuum chamber (22), a vacuumizing port (28) is arranged on the surface of the case cover (24), and the vacuumizing port (28) is communicated with the air exhaust pipe (41).
  4. 4. The apparatus for the electrical resistance method growth of large-sized silicon carbide single crystals as set forth in claim 1, wherein the large-sized silicon single crystal growth mechanism further comprises a mounting frame (34), the bottom of the mounting frame (34) is disposed at the top of the crucible tray (33), and a guide cylinder (35) is bolted to the top of the mounting frame (34).
  5. 5. A resistance method growth device of large-size silicon carbide single crystals according to claim 4 is characterized in that a crucible (36) for containing silicon carbide powder is arranged at the top of a crucible tray (33), a cooling flow channel (37) is arranged in a mounting frame (34), the lower end of the cooling flow channel (37) penetrates through the crucible tray (33) and a supporting piece (32), and the end part of the cooling flow channel (37) is externally connected with a water cooling device.
  6. 6. A resistance method growth apparatus for large-sized silicon carbide single crystals as set forth in claim 1, wherein said large-sized silicon single crystal growth mechanism further comprises a fixing plate (38), said fixing plate (38) being disposed on top of the first mounting bar (27), a seed crystal (39) being fixedly connected to the bottom of said fixing plate (38).
  7. 7. The resistive growth apparatus of large-scale silicon carbide single crystal according to claim 4, wherein the guide cylinder (35) comprises a cylinder body (351), the diameter of the upper end of the cylinder body (351) is larger than that of the lower end of the cylinder body, a gas phase temporary storage cavity (353) is formed in the cylinder body (351), and a gas phase collecting hole (352) is formed in the bottom of the inner cavity of the gas phase temporary storage cavity (353).
  8. 8. The resistive growth apparatus of large-size silicon carbide single crystal according to claim 7, wherein a spiral diversion trench (354) is formed at the top of the inner cavity of the gas phase temporary storage cavity (353), a cooling cavity (355) is formed inside the cylinder (351), a mounting plate (356) is arranged at the bottom of the cylinder (351), a communication hole (357) is formed at the bottom of the mounting plate (356), and the inside of the cooling cavity (355) is communicated with the cooling flow channel (37) through the communication hole.
  9. 9. The resistive growth apparatus of large-size silicon carbide single crystal according to claim 1, wherein the multistage vacuumizing mechanism further comprises a buffer gas tank (45), the inside of the buffer gas tank (45) is communicated with the output pipe (44), the inner wall of the buffer gas tank (45) is connected with a second vacuum pump (48) through a communicating pipe (46), and a second one-way valve (47) is arranged in the communicating pipe (46).
  10. 10. A method of using the resistance method growth apparatus for a large-size silicon carbide single crystal as set forth in any one of claims 1 to 9, characterized by comprising S1, equipment assembling and preparing, namely fixing an integrated bottom plate, installing an inert gas cylinder and related pipelines, sealing a box cover, placing a crucible filled with silicon carbide powder, fixing a guide cylinder, connecting water cooling equipment with a cooling flow channel, and communicating all parts of a vacuumizing assembly; S2, system vacuumizing and leak detection, namely, firstly starting a first vacuum pump to coarsely pump a vacuum cavity, then starting a second vacuum pump to pump air secondarily through a buffer gas tank, reducing the air pressure to a growth standard, closing a valve to maintain the pressure for 30 minutes, and detecting the leak rate of the system; S3, heating and gasifying the silicon carbide raw material, namely starting a graphite heating element, heating the vacuum cavity to 2100-2300 ℃ at the speed of 5-10 ℃ per minute, and introducing inert gas to maintain the pressure of 10-100mbar when the temperature reaches 1800 ℃, wherein the silicon carbide powder is decomposed into gas-phase substances at high temperature, and enters a gas-phase temporary storage cavity of the guide cylinder through a gas-phase collecting hole; S4, in an ultrahigh-pressure rapid growth stage, when the surface temperature of the seed crystal is stabilized at 2150+/-5 ℃, argon is rapidly injected through an inert gas inlet mechanism, the system pressure is increased from 10-100mbar to 500-800mbar within 30 minutes, a water cooling device is synchronously started, the flow rate of cooling liquid in a cooling cavity of a guide cylinder is increased, the temperature of the outer wall of the guide cylinder is maintained at 800-1000 ℃ to form a radial temperature gradient of 200-300 ℃, a gas phase substance forms a stable clockwise spiral rising flow field through a spiral flow guide groove under a high-pressure environment, the retention time is prolonged by 20%, when the temperature field is offset due to pressure rising, the power of a graphite heating piece is automatically regulated, the constant growth temperature of 2150+/-3 ℃ is maintained through the fine adjustment of the distance between the crucible and the seed crystal by a cylinder, and the SiC crystal growth rate is increased to 1.2-1.5mm/h under the pressure of 500-800mbar, and the polycrystallization risk is avoided by adjusting the flow rate of the argon and the cooling strength of the guide cylinder; S5, vapor phase transportation and single crystal growth, wherein vapor phase substances are uniformly distributed on the surface of the seed crystal under the action of a spiral diversion trench, a water cooling device adjusts the flow of cooling liquid, controls the temperature of a cooling cavity of a diversion drum to form an axial temperature gradient, a cylinder slowly lifts a supporting piece to maintain a constant growth interface, and the temperature and the pressure are monitored and adjusted through an observation window, an infrared thermometer and a pressure sensor; S6, annealing and cooling the crystal, namely, after the growth is finished, preserving the temperature at 2000-2100 ℃ for 2-4 hours, annealing in situ to eliminate stress, slowly cooling to room temperature at the rate of 10-20 ℃ per hour, synchronously increasing the pressure of inert gas to the atmospheric pressure step by step, and closing the water cooling equipment to take out the silicon carbide single crystal after the growth is finished.

Description

Resistance method growth equipment and method for large-size silicon carbide single crystal Technical Field The invention relates to the technical field of silicon single crystal preparation, in particular to resistance method growth equipment and method of a large-size silicon carbide single crystal. Background Silicon carbide (SiC) is used as a third-generation semiconductor core material, and plays a key role in the fields of new energy automobile power devices, 5G base station radio frequency modules, rail transit high-voltage power transmission and distribution and the like by virtue of high breakdown field strength, high electron transfer rate and excellent high temperature resistance. The large-size silicon carbide single crystal substrate is the basis for realizing high-performance devices, and the preparation technology of the large-size silicon carbide single crystal substrate directly determines the development level of a semiconductor industry chain. The resistance method growth equipment is used as core equipment for preparing silicon carbide single crystals, and is important to improve the crystal quality and the production efficiency by precisely controlling a temperature field, a gas environment and a crystal growth interface. In the resistance method growth scene of the large-size silicon carbide single crystal, the conventional equipment has low gas phase molecular transportation efficiency under the conventional growth pressure, so that the growth rate is slow, and the growing market demand is difficult to meet, meanwhile, the conventional guide cylinder structure cannot adapt to the growing demand of the large-size silicon carbide single crystal, and the gas phase substances easily generate concentration gradient in the transmission process, so that the growth quality difference between the edge and the central area of the crystal is obvious, and therefore, the resistance method growth equipment and the resistance method of the large-size silicon carbide single crystal are provided. Disclosure of Invention The invention provides a resistance method growth device and method for large-size silicon carbide single crystals, which are used for solving the problems that the conventional growth pressure of the conventional device provided in the background art is low in silicon carbide gas phase molecular transportation efficiency, so that the growth rate is slow and the growing market demand is difficult to meet, meanwhile, the conventional guide cylinder structure cannot adapt to the growth demand of large-size crystals, concentration gradient is easy to generate in the transmission process of gas phase substances, so that the growth quality difference between the edges and the central area of the crystals is obvious, and the resistance method growth device and method for large-size silicon carbide single crystals are provided. In order to solve the technical problems, the invention adopts the following technical scheme: The resistance method growth equipment and method for the large-size silicon carbide single crystal comprise an inert gas inlet mechanism, a heating mechanism and an output end, wherein the inert gas inlet mechanism comprises an integrated bottom plate, a fixing ring is fixedly connected to the top of the integrated bottom plate, an inert gas cylinder is fixedly connected to the inside of the fixing ring, the heating mechanism comprises an insulation box body, a vacuum cavity is arranged at the upper end of the insulation box body, a graphite heating piece is fixedly connected to the inner wall of the vacuum cavity, a box cover is arranged at the top of the insulation box body, the large-size silicon single crystal growth mechanism comprises a cylinder, the bottom of the cylinder is fixedly connected with the inner wall of the lower end of the insulation box body, a supporting piece is fixedly connected to the output end of the cylinder, a crucible tray is fixedly connected to the top of the supporting piece, the multistage vacuumizing mechanism comprises an exhaust pipe, a first one-way valve is arranged in the interior of the exhaust pipe, a first vacuum pump is arranged at one end of the exhaust pipe, and an output pipe is arranged at the output end of the first vacuum pump. The technical scheme of the invention is further improved in that the inert gas inlet mechanism further comprises a gas pipe, and an electromagnetic valve is arranged in the gas pipe. The heating mechanism is further improved in that the heating mechanism further comprises an observation window, the observation window is arranged on the surface of the box cover, the bottom of the inner cavity of the vacuum cavity is fixedly connected with a first mounting rod, the surface of the box cover is provided with a vacuumizing port, and the vacuumizing port is communicated with the exhaust pipe. The technical scheme of the invention is further improved in that the large-size silicon single crystal growth mecha