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CN-121974550-A - System and method for preparing low-bubble-density quartz crucible

CN121974550ACN 121974550 ACN121974550 ACN 121974550ACN-121974550-A

Abstract

The invention discloses a system and a method for preparing a quartz crucible with low bubble density, belonging to the technical field of crucible production, wherein the system comprises a mould air permeability structure optimization module, a feeding proportion optimization module, an electrode control module and a vacuum control module; the air permeability structure optimization module of the die is provided with a plurality of unevenly distributed air holes and a plurality of temperature control areas for independently controlling temperature, the feeding proportion optimization module comprises a storage and distribution device for realizing gradient particle grade feeding, the electrode control module comprises an electrode group with adjustable position and angle and a pulse current generation unit, and the vacuum control module comprises a graded air extraction pipeline with asymmetric pipeline diameter and an intelligent variable frequency control unit. The invention greatly reduces the density of micro bubbles in the liquid level line area of the upper opening of the crucible, and solves the problem that the stability and the crystal quality of the subsequent crystal bar growth are affected due to the overhigh density of the liquid level line of the upper opening of the quartz crucible in the prior art.

Inventors

  • CHENG PAN
  • WAN PENGYUAN
  • LIU WEI

Assignees

  • 江苏复高新材料科技有限公司

Dates

Publication Date
20260505
Application Date
20260121

Claims (10)

  1. 1. The system for preparing the quartz crucible with low bubble density is characterized by comprising a mold air permeability structure optimization module, a feeding proportion optimization module, an electrode control module and a vacuum control module; The mold ventilation structure optimization module comprises a crucible mold made of a porous gradient composite material, wherein a plurality of ventilation holes which are unevenly distributed and have different pore diameters are formed in the crucible mold, a plurality of temperature control areas which are independently controlled in temperature are integrated on the inner wall of the crucible mold, and the distribution of the temperature control areas is related to the distribution of the ventilation holes; the feeding proportion optimization module comprises a storage and distribution device for realizing gradient particle grade feeding; the electrode control module comprises an electrode group with adjustable position and angle and a pulse current generating unit for supplying power to the electrode group; The vacuum control module comprises a graded air extraction pipeline with asymmetric pipeline diameters and an intelligent variable frequency regulation and control unit, wherein a plurality of pressure sensors and gas flow sensors are arranged on the graded air extraction pipeline, and the intelligent variable frequency regulation and control unit dynamically adjusts the air extraction parameters of the graded air extraction pipeline based on feedback parameters of the pressure sensors and the gas flow sensors.
  2. 2. The system for preparing a low bubble density quartz crucible according to claim 1, wherein the crucible mold is divided into a plurality of temperature controlled zones of independent temperature control along its axial and/or circumferential direction, each of the temperature controlled zones having independent heating and/or cooling elements integrated therein; The air holes on the crucible mold are divided into a plurality of air hole distribution areas, a plurality of temperature control areas are in one-to-one correspondence with a plurality of air hole distribution areas, wherein the aperture and the aperture density of the air holes in at least two different air hole distribution areas are not identical.
  3. 3. The system for preparing a low bubble density quartz crucible of claim 2, wherein the plurality of independently temperature controlled zones integrated on the inner wall of the crucible mold comprises at least a first temperature controlled zone corresponding to the position of the upper port level line of the quartz crucible and a second temperature controlled zone adjacent to the first temperature controlled zone; the vent hole opening density and the aperture of the vent hole distribution area corresponding to the first temperature control area are larger than those of the vent hole distribution area corresponding to the second temperature control area.
  4. 4. The system for preparing a low bubble density quartz crucible according to claim 3, wherein in the vent hole distribution area corresponding to the first temperature control area, vent holes are distributed in a matrix, and the interval between two adjacent vent holes is 25mm; The set control temperature of the first temperature control area is higher than the set control temperature of the second temperature control area.
  5. 5. The system for preparing a low bubble density quartz crucible of claim 1, wherein the storage and delivery device comprises a storage mechanism and a delivery mechanism, the storage mechanism comprises at least three mutually independent storage bins, the three storage bins are respectively used for storing quartz raw materials with different particle size ranges, and the delivery mechanism is used for controlling the quartz raw materials in the storage bins to be sequentially delivered into the crucible mold according to a set proportion and a layer sequence.
  6. 6. The system for preparing a low bubble density quartz crucible of claim 5, wherein the storage mechanism comprises: the first storage bin is used for storing coarse-grain quartz sand with grain size larger than 40 meshes; the second storage bin is used for storing medium-grain-size quartz grains with grain sizes between 70 meshes and 120 meshes; The third storage bin is used for storing nano-grade silicon micro powder with the particle size smaller than 325 meshes; The distribution mechanism sequentially controls the coarse grain diameter quartz sand in the first storage bin to be thrown into the bottom of the crucible mold to form a core layer, the medium grain diameter quartz particles in the second storage bin to be thrown into the middle of the crucible mold to form a transition layer, and the nano-scale silicon micro powder in the third storage bin to be thrown into the top of the crucible mold to form a surface layer, so that gradient grain grade distribution and feeding are realized.
  7. 7. The system for preparing a low bubble density quartz crucible of claim 1, wherein the electrode control module further comprises: the electrode driving mechanism is used for driving each electrode in the electrode group to move in position and adjusting the opening angle of the electrode; The state detection unit is used for acquiring melting progress information and temperature distribution information of the melt in the crucible die in real time; The control unit is in signal connection with the electrode driving mechanism and the state detection unit, generates and sends an adjusting instruction of the position and the angle of each electrode in the electrode group according to the chemical material progress information and the temperature distribution information acquired by the state detection unit, and the electrode driving mechanism drives each electrode in the electrode group to move in position and adjust the opening angle of the electrode according to the received adjusting instruction of the position and the angle of each electrode.
  8. 8. The system for preparing a quartz crucible with low bubble density according to claim 7, wherein the control unit stores a three-dimensional electric field-thermal field coupling simulation model, the control unit obtains melting progress information and temperature distribution information of the melt in the crucible mold from the state detection unit, calculates position and angle parameters of each electrode in the electrode group through the three-dimensional electric field-thermal field coupling simulation model, and generates an adjustment instruction of the position and angle of each electrode in the electrode group according to the obtained position and angle parameters of each electrode in the electrode group.
  9. 9. The system for preparing a low bubble density quartz crucible of claim 1, wherein the graded pumping line comprises at least a first pumping branch disposed at a level line position of an upper port of the crucible mold and a second pumping branch disposed at a lower middle position of the crucible mold, and wherein a pipe diameter of the first pumping branch is larger than a pipe diameter of the second pumping branch.
  10. 10. A method for producing a low bubble density quartz crucible, wherein the system for producing a low bubble density quartz crucible as claimed in claim 1 is employed, comprising the steps of: Preparing a crucible mold, wherein the crucible mold is made of a porous gradient composite material, a plurality of ventilation holes which are unevenly distributed and have different pore diameters are formed in the crucible mold, a plurality of temperature control areas which are independently controlled in temperature are integrated on the inner wall of the crucible mold, and the distribution of the temperature control areas is related to the distribution of the ventilation holes; Adopting the storage and distribution device to perform layered distribution on at least three quartz raw materials with different particle size ranges in the direction from the bottom to the top of the crucible die so as to form gradient particle grade distribution and feeding from bottom to top; A melting control step of placing the electrodes in the electrode group in the melt of the crucible mold and applying pulse current to each electrode in the electrode group through the pulse current generating unit; And in the vacuum pumping step, pumping the interior of the crucible mold through a graded pumping pipeline with an asymmetric pipeline diameter in the melting process, and dynamically adjusting pumping parameters of the graded pumping pipeline by the intelligent variable-frequency regulation and control unit based on feedback parameters of the pressure sensor and the gas flow sensor.

Description

System and method for preparing low-bubble-density quartz crucible Technical Field The invention relates to the technical field of crucible production, in particular to a system and a method for preparing a quartz crucible with low bubble density. Background With the rapid development of industries such as global semiconductors, new energy sources and the like, the quartz crucible is used as a key basic consumable material for crystal growth, the market demand of the quartz crucible is continuously increased, and the requirements on the product quality are also increasingly severe. In the melting process of the quartz crucible, the problem of micro bubbles at the liquid level line position (namely at the solid-liquid-gas three-phase interface) of the upper opening of the melt is a core technical bottleneck which influences the quality of the inner wall of the quartz crucible and further restricts the crystal growth yield and performance of monocrystalline silicon and the like. At present, a traditional graphite mold is generally adopted in the industry for melting. The graphite mold has the common problems of poor distribution uniformity of ventilation holes and single pore diameter structure, so that the surface tension of a melt is unbalanced, a stable and orderly exhaust channel is difficult to form, and micro bubbles are abnormally gathered and detained in a liquid level line area. Meanwhile, the whole melting process is highly dependent on experience of operators to carry out parameter regulation and control, lacks accurate theoretical model guidance, for example, electrode positions and current parameters are fixed, and is difficult to adapt to a temperature field and a flow field which dynamically change in the material melting process, and new bubble nucleation is easily induced due to current concentration. Meanwhile, the vacuum pumping system mostly adopts a pipeline layout with fixed flow rate and uniform diameter, the migration paths and degassing efficiency differences of bubbles at different melt depths are not considered, and the inhibition and removal capability of micro bubbles is limited. The above factors together lead to high bubble density and large liquid level fluctuation of the liquid level line at the upper opening of the prepared quartz crucible, and seriously influence the stability and crystal quality of the subsequent crystal rod growth. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a system and a method for preparing a low-bubble density quartz crucible, which can reduce the bubble density of the liquid level line at the upper opening of the quartz crucible and improve the growth stability and the crystal quality of the subsequent crystal rod. In order to solve the technical problems, the invention adopts the following technical scheme: A system for preparing a quartz crucible with low bubble density comprises a mold air permeability structure optimization module, a feeding proportion optimization module, an electrode control module and a vacuum control module; The mold ventilation structure optimization module comprises a crucible mold made of a porous gradient composite material, wherein a plurality of ventilation holes which are unevenly distributed and have different pore diameters are formed in the crucible mold, a plurality of temperature control areas which are independently controlled in temperature are integrated on the inner wall of the crucible mold, and the distribution of the temperature control areas is related to the distribution of the ventilation holes; the feeding proportion optimization module comprises a storage and distribution device for realizing gradient particle grade feeding; the electrode control module comprises an electrode group with adjustable position and angle and a pulse current generating unit for supplying power to the electrode group; The vacuum control module comprises a graded air extraction pipeline with asymmetric pipeline diameters and an intelligent variable frequency regulation and control unit, wherein a plurality of pressure sensors and gas flow sensors are arranged on the graded air extraction pipeline, and the intelligent variable frequency regulation and control unit dynamically adjusts the air extraction parameters of the graded air extraction pipeline based on feedback parameters of the pressure sensors and the gas flow sensors. Preferably, the crucible mold is divided into a plurality of temperature control areas with independent temperature control along the axial direction and/or the circumferential direction, and independent heating and/or cooling elements are integrated in each temperature control area; The air holes on the crucible mold are divided into a plurality of air hole distribution areas, a plurality of temperature control areas are in one-to-one correspondence with a plurality of air hole distribution areas, wherein the aperture and the aperture density of the air holes in