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CN-122013317-A - Preparation method and application of monocrystalline silicon rod

CN122013317ACN 122013317 ACN122013317 ACN 122013317ACN-122013317-A

Abstract

The invention relates to the field of semiconductors, in particular to a preparation method and application of a monocrystalline silicon rod. The preparation method of the monocrystalline silicon rod comprises the following steps of (a) filling polycrystalline silicon raw materials to form a bottom raw material layer, filling a plurality of polycrystalline silicon raw material layers on the bottom raw material layer, doping materials into at least one polycrystalline silicon raw material layer, and (b) compacting, vacuum treating, heating and melting, seeding, shouldering, isodiametric growth, ending and annealing after filling the raw materials. According to the method, through a collaborative strategy of layered filling and dynamic supplementation, the problem of uneven doping caused by low segregation and high evaporation of antimony element is effectively solved, the uniformity of axial and radial doping of the monocrystalline silicon rod is remarkably improved, and the crystal defect density is reduced. Meanwhile, the method is suitable for various preparation scenes such as conventional, high-precision, large-diameter and the like, realizes precise control of resistivity and process universality, and provides high-quality substrate materials for high-end semiconductor devices.

Inventors

  • SHI KUN
  • LIU XIN
  • XU YAO
  • Qiao le
  • FU MINGQUAN

Assignees

  • 青海高景太阳能科技有限公司
  • 高景太阳能股份有限公司

Dates

Publication Date
20260512
Application Date
20260409

Claims (10)

  1. 1. The preparation method of the monocrystalline silicon rod is characterized by comprising the following steps of: (a) Filling a polycrystalline silicon raw material to form a bottom raw material layer, wherein a plurality of polycrystalline silicon raw material layers are filled on the bottom raw material layer, and doping materials are doped in at least one polycrystalline silicon raw material layer; (b) After raw materials are filled, compacting treatment, vacuum treatment, heating and melting treatment, seeding, shouldering, constant diameter growth, ending and annealing are carried out.
  2. 2. The method for producing a single crystal silicon rod according to claim 1, characterized by comprising at least one of the following technical features: (1) The bottom raw material layer is 15-80 wt% of the total amount of the polysilicon raw material; (2) The doping amount of the doping material in the polysilicon raw material layer is 50-100 wt% of the first target doping amount; (3) The doping amount of the doping material in each polysilicon raw material layer is 20-60 wt% of the first target doping amount.
  3. 3. The method for producing a single crystal silicon rod according to claim 2, wherein when the doping amount of the doping material in the polycrystalline silicon raw material layer is less than 100wt% of the first target doping amount, the remaining doping material is doped into the melt at the initial stage of the isodiametric growth so that the doping amount of the doping material is 100wt% of the first target doping amount.
  4. 4. The method of producing a single crystal silicon rod according to claim 2, wherein when the doping amount of the doping material in the polycrystalline silicon raw material layer is 100wt% of the first target doping amount, the doping material is additionally doped in the constant diameter growth stage in any one of the following manners: (1) In the isodiametric growth stage, the doping material is doped in real time according to the real-time change of the resistivity of the melt; (2) And respectively supplementing and doping the doping materials in the early stage, the middle stage and the later stage of the equal-diameter growth, wherein the doping amount of the doping materials in the early stage is 10-40 wt% of the second target doping amount, the doping amount of the doping materials in the middle stage is 20-60 wt% of the second target doping amount, and the doping amount of the doping materials in the later stage is 10-40 wt% of the second target doping amount.
  5. 5. The method of producing a single crystal silicon rod according to claim 1, wherein when the doping material is doped in a plurality of the polycrystalline silicon raw material layers, the doping concentration of the doping material is sequentially decreased from the underlying raw material layer to the polycrystalline silicon raw material layer.
  6. 6. The method for producing a single crystal silicon rod according to claim 1, characterized by comprising at least one of the following technical features: (1) The vacuum degree of the vacuum treatment is 0.6X10 5 ~1×10 5 Pa; (2) The heating and melting treatment keeps the temperature of the melt to be more than 15 ℃ higher than the melting point of silicon; (3) And in the heating and melting treatment stage, a longitudinal steady magnetic field of 0.2-0.3T is applied.
  7. 7. The method for producing a silicon single crystal rod according to claim 1, wherein the pulling rate of the seeding is 0.5 to 0.8mm/min, and the rotation speed is 20 to 30rpm; and/or the pulling speed of the shouldering is 1.2-1.8 mm/min, and the rotating speed is 8-12 rpm.
  8. 8. The method for producing a silicon single crystal rod according to claim 1, wherein the pulling rate of the isodiametric growth is 0.8 to 1.2mm/min, and the rotation speed is 12 to 18rpm; And/or applying a longitudinal steady magnetic field of 0.2-0.3T in the constant diameter growth stage.
  9. 9. The method for producing a silicon single crystal rod according to claim 1, wherein the pulling speed of the ending is 0.4 to 0.6mm/min, and the rotation speed is 5 to 8rpm; And/or the annealing temperature is 1150-1250 ℃, the time is 5-8 h, and the cooling rate is 8-15 ℃ per hour.
  10. 10. A method for manufacturing a semiconductor device, characterized by comprising the method for manufacturing a single crystal silicon rod according to any one of claims 1 to 9.

Description

Preparation method and application of monocrystalline silicon rod Technical Field The invention relates to the field of semiconductors, in particular to a preparation method and application of a monocrystalline silicon rod. Background In the field of monocrystalline silicon preparation, a zone-melting Czochralski (RCZ) method is a key process for preparing high-purity monocrystalline silicon, and the antimony-doped monocrystalline silicon has the characteristics of low resistance, high carrier concentration and the like, and is widely applied to the fields of power semiconductors, radio frequency devices and the like. In the prior art, the preparation of the antimony doped monocrystalline silicon rod mostly adopts the 'raw material premixing type doping' or the 'single-time adding type doping in the crystal pulling process', namely antimony particles and polycrystalline silicon raw materials are directly mixed before charging or antimony doping agents are added into a melt at one time in the initial stage of crystal pulling, and then the conventional RCZ process is adopted to complete crystal growth. For example, some of the prior art (e.g., the disclosed zone-melting antimony-doping process) relies on a single doping sequence and fixed process parameters to achieve doping. The prior art has the following defects due to the characteristic of low segregation coefficient and high evaporation coefficient of antimony: 1. The doping uniformity is poor, the attenuation of the axial doping concentration from the head to the tail of the ingot is obvious, the resistivity deviation can reach +/-15%, and the doping of the radial center and the edge is uneven, so that the electrical property consistency of the silicon wafer is poor. 2. The antimony doping causes melt convection disorder, so that defects such as dislocation, facets, cavities and the like are easy to generate, the crystal integrity is reduced, and the reliability of the device is affected. 3. The resistivity control precision is low, the doping amount cannot be controlled accurately, the resistivity fluctuation among batches is large, and the requirement of high-end devices on the precision within +/-3% of the resistivity is difficult to meet. 4. The process universality is weak, and the adaptability is poor for single crystal silicon rods with different diameters (such as 6 inches and 8 inches) and different resistivity requirements due to lack of specific doping process design. In view of this, the present invention has been made. Disclosure of Invention The invention aims to solve the technical problems of poor doping uniformity, more crystal defects, low resistivity control precision and weak process universality in the preparation of an antimony-doped monocrystalline silicon rod by the conventional RCZ method, and provides a preparation method and application of the monocrystalline silicon rod. In order to achieve the above object of the present invention, the following technical solutions are specifically adopted: a preparation method of a monocrystalline silicon rod comprises the following steps: (a) Filling a polycrystalline silicon raw material to form a bottom raw material layer, wherein a plurality of polycrystalline silicon raw material layers are filled on the bottom raw material layer, and doping materials are doped in at least one polycrystalline silicon raw material layer; (b) After raw materials are filled, compacting treatment, vacuum treatment, heating and melting treatment, seeding, shouldering, constant diameter growth, ending and annealing are carried out. According to the preparation method of the monocrystalline silicon rod, through a collaborative strategy of layered filling and dynamic supplementation, the problem of uneven doping caused by low segregation and high evaporation of antimony elements is effectively solved, the uniformity of axial and radial doping of the monocrystalline silicon rod is remarkably improved, and the crystal defect density is reduced. Meanwhile, the method is suitable for various preparation scenes such as conventional, high-precision, large-diameter and the like, realizes precise control of resistivity and process universality, and provides high-quality substrate materials for high-end semiconductor devices. Preferably, the underlayer is 15wt% to 80wt% of the total amount of polysilicon raw material, including but not limited to a point value of any one of 15wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt%, or a range value between any two. Preferably, the doping amount of the doping material in the polysilicon raw material layer is 50wt% to 100wt% of the first target doping amount, including but not limited to a point value of any one of 50wt%, 60wt%, 70wt%, 80wt%, 90wt% or 100wt% or a range value between any two. The first target doping amount has no fixed unified value and needs to be flexibly adjusted by combining the target resistivity and the total amount of the polysilicon raw materials.