Method for moving equal-diameter crucible in early stage

Abstract

The invention belongs to the technical field of single crystal production, and relates to an equal-diameter early-stage crucible moving method which comprises the following steps: identifying the actual pulling speed V1 of a single crystal; the actual pulling speed V1 and the set pulling speed V2 are compared, and the difference value between the actual pulling speed V1 and the set pulling speed V2 is calculated; calculating a corresponding crucible position compensation coefficient alpha according to the difference value; and calculating the actually required moving speed V according to the crucible position compensation coefficient alpha, the crucible-to-heel ratio tau and the liquid level compensation speed V3, so that the crucible shaft jacks the crucible or descends the crucible according to the V. The method has the beneficial effects that the corresponding crucible position compensation coefficient is calculated according to the difference value between the actual pulling speed and the set pulling speed, whether the crucible is lifted or descended is judged, the actually needed crucible moving speed is obtained by combining the crucible following ratio and the liquid level compensation speed, and the crucible shaft is adjusted on the basis, so that the crucible is rapidly in place; and the temperature gradient required by crystal growth is met, so that the growth curve of the single crystal is better matched, the interface depth of the single crystal can be improved, and the aim of increasing the yield is finally achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of single crystal production and relates to a method for moving a crucible in the early stage with equal diameter. Background Art

[0002] Since the temperature-stabilizing crucible position is lower than the equal-diameter crucible position, it is beneficial to the temperature stabilization, crystal induction and shoulder release processes of the single crystal. Therefore, the temperature-stabilizing crucible position needs to be lower than the equal-diameter crucible position. However, in order to ensure that the single crystal has sufficient temperature gradient, the crucible position needs to be quickly raised to a suitable position after the single crystal enters the equal-diameter state. The current conventional process is to use the crucible level ratio and liquid level detection and liquid level compensation to push the crucible. However, this method can only adjust the speed of pushing the crucible by the distance between the guide tube mouth and the liquid surface. The adjustment speed is slow, resulting in the single crystal being unable to reach the maximum pulling speed for a long time, and easily causing excessive cooling for growth control to cause breakage, affecting production. Therefore, a method of moving the crucible in the early stage of equal diameter is needed to solve the above technical problems. Summary of the invention

[0003] In order to solve the above-mentioned technical problems, the present invention provides a method for moving the crucible in advance with equal diameter, which can quickly confirm the actual moving speed of the top crucible or the lowering crucible, so that the crucible can be quickly put in place to meet the temperature gradient required for crystal growth, so that the single crystal growth curve can be more matched, and then the single crystal interface depth can be improved, ultimately achieving the purpose of increasing production.

[0004] The technical solution adopted by the present invention is: a method for moving a crucible in the early stage with equal diameter, characterized in that it comprises the following steps:

[0005] Identify the actual pulling speed V of the single crystal 1 ;

[0006] Compare the actual casting speed V 1 and set the pulling speed V 2 , and calculate the difference between the two;

[0007] Calculate the corresponding crucible position compensation coefficient α according to the difference;

[0008] According to the crucible position compensation coefficient α, crucible to heel ratio τ and liquid level compensation speed V 3 The actually required moving speed V is calculated so that the crucible axis can move up or down the crucible according to the moving speed V.

[0009] Furthermore, the moving speed V, V = V 1 ·τ+V 3 +(V 2 -V 1 )·α.

[0010] Further, the difference is -50 to 50 mm / h.

[0011] Furthermore, the crucible position compensation coefficient α is -10 to 10.

[0012] Furthermore, when the actual pulling speed V 1 Higher than the set pulling speed V 2 When the crucible position compensation coefficient α is a negative number, the crucible axis moves down at the moving speed V.

[0013] Furthermore, when the actual pulling speed V 1 Lower than the set pulling speed V 2 When the crucible position compensation coefficient 2 is a positive number, the crucible axis moves up the crucible at the moving speed V.

[0014] Furthermore, when the actual pulling speed V 1 Equal to the set pulling speed V 2 , the crucible position compensation coefficient 2 is zero.

[0015] Furthermore, the crucible to heel ratio τ is obtained by the descending speed of the liquid surface.

[0016] Furthermore, the liquid level compensation speed V is obtained according to the change in the distance between the lower edge of the guide tube and the liquid surface. 3 .

[0017] Furthermore, the actual pulling speed V of the single crystal is identified by the pulling head. 1 .

[0018] The present invention relates to a method for moving a crucible in the early stage of equal diameter. In the method, a corresponding crucible position compensation coefficient is calculated according to the difference between an actual pulling speed and a set pulling speed, and it is determined whether the crucible is raised or lowered. Then, the actual required crucible moving speed is obtained by combining the crucible-to-heel ratio and the liquid level compensation speed. Based on this, the crucible axis is adjusted to enable the crucible to be quickly in place, meet the temperature gradient required for crystal growth, make the single crystal growth curve more matched, and further improve the single crystal interface depth, thereby ultimately achieving the purpose of increasing production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of an embodiment provided by the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0021] In the description of the embodiments of the present invention, it should be understood that the terms "above", "below", etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0022] The present invention provides a method for moving a crucible in the early stage with equal diameter, characterized in that it comprises the following steps:

[0023] Identify the actual pulling speed V of the single crystal 1 ;

[0024] Compare the actual pulling speed V 1 and set the pulling speed V 2 , and calculate the difference between the two;

[0025] Calculate the corresponding crucible position compensation coefficient α according to the difference;

[0026] According to the crucible position compensation coefficient α, crucible to heel ratio τ and liquid level compensation speed V 3 The actual required moving speed V is calculated so that the crucible axis can be lifted or lowered according to the above moving speed V. The actual moving speed V of the single crystal calculated by the crucible-to-heel ratio, the crucible position compensation coefficient and the liquid level compensation speed is more accurate, which can make the single crystal growth curve more matched with the set curve. At the same time, the moving speed of the crucible can be accelerated, so that the crucible position can be quickly raised or lowered to a suitable position, and the temperature gradient required for crystal growth can be quickly reached. The single crystal pulling speed can also be increased accordingly, and the single crystal interface depth can also be improved, ultimately achieving the purpose of increasing production.

[0027] Preferably, the moving speed V, V = V 1 ·τ+V 3 +(V 2 -V 1 )·α, the more precise crucible axis moving speed can make the single crystal enter the later stage of equal diameter state, and quickly adjust the crucible position to the appropriate position, so that the single crystal can reach the maximum pulling speed in the shortest time, avoiding the single crystal breaking caused by excessive cooling due to growth control, and improving the yield.

[0028] Preferably, the difference is -50 to 50 mm / h.

[0029] Preferably, the crucible position compensation coefficient α is -10 to 10.

[0030] Preferably, when the actual pulling speed V 1 Higher than the set pulling speed V 2 When , the crucible position compensation coefficient α is a negative number, and the crucible axis moves down at the moving speed V.

[0031] Preferably, when the actual pulling speed V 1 Lower than the set pulling speed V 2 When the crucible position compensation coefficient α is a positive number, the crucible axis moves up the crucible at the moving speed V. 1 Lower than the set pulling speed V 2When the temperature at the growth interface is high, the crystallization speed of the single crystal slows down, and the diameter of the single crystal tends to shrink. 1 and set the pulling speed V 2 The difference between the two is multiplied by the crucible position compensation coefficient α, plus the crucible to heel ratio multiplied by the actual pulling speed and the liquid level compensation speed V 3 , calculate the actual moving speed of the crucible to make the adjustment more precise and better meet the temperature gradient required for crystal growth.

[0032] Preferably, when the actual pulling speed V 1 Equal to the set pulling speed V 2 When , the crucible position compensation coefficient α is zero.

[0033] Preferably, the crucible to heel ratio τ is obtained by the descending speed of the liquid level.

[0034] Preferably, the liquid level compensation speed V is obtained according to the change in the distance between the lower edge of the guide tube and the liquid surface. 3 .

[0035] Preferably, the actual pulling speed V of the single crystal is identified by the pulling head. 1 .

[0036] It should be noted that the crucible to heel ratio τ and liquid level compensation speed V 3 The acquisition and calculation of are technical means commonly used by those skilled in the art and are common knowledge, so they will not be elaborated in detail.

[0037] The present invention relates to a tail-end single crystal crystallization method. In the method, a corresponding crucible position compensation coefficient is calculated according to the difference between the actual pulling speed and the set pulling speed, and it is judged whether to raise the crucible or lower the crucible. Then, the actual required crucible moving speed is obtained by combining the crucible-to-heel ratio and the liquid level compensation speed. Based on this, the crucible axis is adjusted to make the crucible quickly in place, meet the temperature gradient required for crystal growth, make the single crystal growth curve more matched, and then improve the single crystal interface depth, and finally achieve the purpose of increasing production.

[0038] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for moving a crucible in an equal diameter phase, characterized in that: The steps include: Identify the actual pulling speed V1 of the single crystal; Comparing the actual pulling speed V1 with the set pulling speed V2, and calculating the difference between the two; Calculate the corresponding crucible position compensation coefficient α according to the difference; The actually required moving speed V is calculated according to the crucible position compensation coefficient α, the crucible-to-heel ratio τ and the liquid level compensation speed V3, so that the crucible axis can be raised or lowered according to the moving speed V.

2. The method for moving the crucible at an equal diameter stage according to claim 1, characterized in that: The moving speed V, V = V1·τ+V3+(V2-V1)·α.

3. The method for moving the crucible at an equal diameter in the early stage according to claim 2, characterized in that: The difference is -50 to 50 mm / h.

4. The method for moving the crucible at an equal diameter stage according to claim 3, characterized in that: The crucible position compensation coefficient α is -10 to 10.

5. The method for moving the crucible at an equal diameter stage according to claim 4, characterized in that: When the actual pulling speed V1 is higher than the set pulling speed V2, the crucible position compensation coefficient α is a negative number, and the crucible axis moves down at the moving speed V.

6. The method for moving the crucible at an equal diameter stage according to claim 4, characterized in that: When the actual pulling speed V1 is lower than the set pulling speed V2, the crucible position compensation coefficient α is a positive number, and the crucible axis moves up the crucible at the moving speed V.

7. The method for moving the crucible at an equal diameter stage according to claim 4, characterized in that: When the actual pulling speed V1 is equal to the set pulling speed V1, the crucible position compensation coefficient α is zero.

8. The method for moving a crucible at an equal diameter in the early stage according to any one of claims 1 to 7, characterized in that: The crucible to heel ratio τ is obtained by the falling speed of the liquid surface.

9. The method for moving the crucible at an equal diameter stage according to claim 8, characterized in that: The liquid level compensation speed V3 is obtained according to the change in the distance between the lower edge of the guide tube and the liquid surface.

10. The method for moving a crucible at an equal diameter in the early stage according to claim 1, characterized in that: The actual pulling speed V1 of the single crystal is recognized by the pulling head.

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