Crystal and preparation method thereof

Abstract

The invention discloses a crystal and a preparation method thereof, and relates to the field of semiconductor manufacturing. The preparation method of the crystal comprises the following steps: installing a polycrystal material and a seed crystal into a zone melting furnace; heating and melting the polycrystal material to obtain a molten polycrystal material; welding the seed crystal with the molten polycrystal material; after the thin neck drawing, shoulder expanding and equal-diameter operation is executed, a crystal is obtained; wherein when the fusion welding of the seed crystal and the molten polycrystal material fails, the fusion welding is stopped, and the operation of increasing the volume of the molten polycrystal material is executed after the fusion welding is stopped, so that the seed crystal and the molten polycrystal material are subjected to fusion welding again. According to the preparation method of the crystal, after welding of the seed crystal and the molten polycrystal material fails, the seed crystal and the molten polycrystal material are welded again by increasing the volume of the molten polycrystal material, the crystal does not need to be prepared again after a zone melting furnace is cooled, the furnace is disassembled and the seed crystal is replaced, the production efficiency of the crystal can be improved, and the production cost can be reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a crystal and a method for preparing the same. Background Art

[0002] In the crystal growth process, the zone melting method is a process that uses a high-frequency magnetic field to heat polycrystalline materials, melt local areas into a molten state, and then cool and solidify to grow into crystals. The zone melting method is also called the suspended zone melting method. Because it does not directly contact other impurity sources, the crystal impurity content is extremely low, and the purity and quality are excellent. However, the process of the zone melting method increases with the increase of the size of the crystal; if the welding fails during the seed crystal welding process, it is necessary to cool down, dismantle the furnace, replace the seed crystal, and then grow the crystal, which seriously affects the production efficiency of the crystal. Summary of the invention

[0003] The purpose of this application is to provide a method for preparing a crystal, which can improve the production efficiency of the crystal and reduce the production cost of the crystal.

[0004] The first aspect of the present application provides a method for preparing a crystal, comprising:

[0005] Installing polycrystalline material and seed crystal into the zone furnace;

[0006] Heating the polycrystalline material to obtain a molten polycrystalline material;

[0007] welding the seed crystal to the molten polycrystalline material;

[0008] After performing operations of pulling a thin neck, expanding shoulders, and equalizing diameters, a crystal is obtained;

[0009] When the seed crystal and the molten polycrystalline material fail to be welded together, the welding is stopped, and after stopping, an operation of increasing the volume of the molten polycrystalline material is performed to re-weld the seed crystal and the molten polycrystalline material.

[0010] In some embodiments, when the seed crystal is welded to the molten polycrystalline material, the moving direction of the polycrystalline material is a first direction, and the step of increasing the volume of the molten polycrystalline material to re-weld the seed crystal to the molten polycrystalline material comprises:

[0011] Increasing the power of the heating material to increase the volume of the molten polycrystalline material;

[0012] reducing the moving speed of the polycrystalline material along the first direction;

[0013] The moving direction of the seed crystal is changed from the first direction to a reverse extension direction of the first direction, and the rotation speed of the seed crystal is reduced so that the seed crystal and the molten polycrystalline material are re-melted.

[0014] In some embodiments, during the process of remelting the seed crystal with the molten polycrystalline material, the power of the heated material is 60-70%, the rotation speed of the polycrystalline material is 1-5 rpm / min, and the moving speed of the polycrystalline material along the first direction is 0 mm / min; the rotation speed of the seed crystal is 5-10 rpm / min, and the moving speed of the seed crystal in the reverse extension direction of the first direction is 0.1-1 mm / min.

[0015] In some embodiments, when the thin neck is broken, the thin neck is heated and melted back to obtain a melted polycrystalline material;

[0016] The seed crystal is re-melted with the remelted polycrystalline material.

[0017] In some embodiments, when the seed crystal is welded to the molten polycrystalline material, the moving direction of the polycrystalline material is a first direction, and the step of heating and melting the narrow neck includes:

[0018] Changing the moving direction of the polycrystalline material from a first direction to a reverse extension direction of the first direction, and reducing the moving speed of the polycrystalline material;

[0019] The heating power of the heating and melting back is increased to heat and melt back the narrow neck.

[0020] In some embodiments, the step of remelting the seed crystal and the remelted polycrystalline material comprises:

[0021] changing the moving direction of the seed crystal from the first direction to a reverse extension direction of the first direction, and reducing the rotation speed of the seed crystal and the moving speed of the seed crystal;

[0022] The moving speed of the seed crystal is made greater than the moving speed of the polycrystalline material, so that the seed crystal and the remelted polycrystalline material are re-melted.

[0023] In some embodiments, in the process of remelting the seed crystal and the remelted polycrystalline material, the heating remelting power is 60-70%, the rotation speed of the polycrystalline material is 1-5 rpm / min, and the moving speed of the polycrystalline material along the reverse extension direction of the first direction is 0.1-0.5 mm / min; the rotation speed of the seed crystal is 5-10 rpm / min, and the moving speed of the seed crystal along the reverse extension direction of the first direction is 1-1.5 mm / min.

[0024] In some embodiments, when the seed crystal is welded with the molten polycrystalline material, the moving direction of the polycrystalline material is a first direction. In the process of heating the polycrystalline material to obtain molten polycrystalline material, the power of the heating material is 50-60%, the rotation speed of the polycrystalline material is 1-5rpm / min, and the moving speed of the polycrystalline material along the first direction is 0mm / min; the rotation speed of the seed crystal is 0rpm / min, and the moving speed of the seed crystal along the first direction is 0mm / min.

[0025] In some embodiments, when the seed crystal is welded with the molten polycrystalline material, the moving direction of the polycrystalline material is a first direction. During the process of drawing a narrow neck, the power of the heated material is 55-65%, the rotation speed of the polycrystalline material is 1-5 rpm / min, and the moving speed of the polycrystalline material along the first direction is 1-2 mm / min; the rotation speed of the seed crystal is 20-30 rpm / min, and the moving speed of the seed crystal along the first direction is 12-15 mm / min.

[0026] In some embodiments, when the seed crystal is welded with the molten polycrystalline material, the moving direction of the polycrystalline material is a first direction. In the process of welding the seed crystal with the molten polycrystalline material, the power of the heated material is 55-65%, the rotation speed of the polycrystalline material is 1-5 rpm / min, and the moving speed of the polycrystalline material along the first direction is 0.1-0.5 mm / min; the rotation speed of the seed crystal is 20-30 rpm / min, and the moving speed of the seed crystal along the first direction is 0.1-1 mm / min.

[0027] The second aspect of the present application provides a crystal prepared by the above-mentioned crystal preparation method, wherein the oxygen content in the crystal is 0 to 1E16 atom / cm 3 .

[0028] The beneficial effects of this application are:

[0029] The present application provides a method for preparing a crystal, comprising: installing polycrystalline material and seed crystal into a zone furnace; heating the polycrystalline material to obtain molten polycrystalline material; fusing the seed crystal with the molten polycrystalline material; after pulling a thin neck, expanding shoulders, and equalizing diameters, a crystal is obtained; wherein, if the seed crystal fails to be fused with the molten polycrystalline material, the volume of the molten polycrystalline material is increased to re-fuse the seed crystal with the molten polycrystalline material. The method for preparing a crystal in the present application, after the seed crystal fails to be fused with the molten polycrystalline material, the volume of the molten polycrystalline material is increased to re-fuse the seed crystal with the molten polycrystalline material, without having to wait for the zone furnace to cool down, dismantle the furnace to replace the seed crystal, and then re-prepare the crystal, which can improve the production efficiency of the crystal and reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A flow chart of a crystal preparation method provided in this application;

[0031] Figure 2 A flow chart of another crystal preparation method provided in this application;

[0032] Figure 3 This is a schematic diagram of the first structure in the crystal preparation process provided in this application;

[0033] Figure 4 A second structural schematic diagram of the crystal preparation process provided in this application;

[0034] Figure 5 A third structural schematic diagram of the crystal preparation process provided in this application;

[0035] Figure 6 This is a schematic diagram of the fourth structure in the crystal preparation process provided in this application;

[0036] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0037] 1. polycrystalline material; 101. melted polycrystalline material; 102. melted polycrystalline material; 2. seed crystal; 3. narrow neck; 4. coil. DETAILED DESCRIPTION

[0038] The technical solution of the present application will be described clearly and completely below in conjunction with the embodiments and drawings of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and simplicity, and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which are applicable regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any quoted numbers (fractions or integers) within the indicated range.

[0039] like Figure 1 , Figure 3-Figure 4 As shown, the first aspect of the present application provides a method for preparing a crystal, comprising:

[0040] Step S1: installing polycrystalline material 1 and seed crystal 2 into a zone melting furnace;

[0041] Step S2: heating the polycrystalline material 1 to obtain a molten polycrystalline material 101;

[0042] Step S3: welding the seed crystal 2 to the molten polycrystalline material 101;

[0043] Step S4: After executing the operations of pulling the narrow neck 3, expanding the shoulders, and equalizing the diameter, a crystal is obtained; wherein, when the seed crystal 2 and the molten polycrystalline material 101 fail to be welded together, the welding is stopped, and after stopping, the volume of the molten polycrystalline material 101 is increased to allow the seed crystal 2 and the molten polycrystalline material 101 to be welded together again.

[0044] It can be understood that after the seed crystal 2 and the molten polycrystalline material 101 fail to weld, the welding is stopped, and the seed crystal 2 and the molten polycrystalline material 101 are re-melted by increasing the volume of the molten polycrystalline material 101. There is no need to wait for the zone furnace to cool down, dismantle the furnace, replace the seed crystal, and then re-prepare the crystal, which can improve the crystal production efficiency and reduce the production cost.

[0045] In some embodiments, when the seed crystal 2 is welded to the molten polycrystalline material 101, the moving direction of the polycrystalline material 1 is the first direction Y, and the step of increasing the volume of the molten polycrystalline material 101 to re-weld the seed crystal 2 to the molten polycrystalline material 101 includes:

[0046] Increasing the power of heating the material to increase the volume of the molten polycrystalline material 101;

[0047] reducing the moving speed of the polycrystalline material 1 along the first direction Y;

[0048] The moving direction of the seed crystal 2 is changed from the first direction Y to an opposite extension direction of the first direction Y, and the rotation speed of the seed crystal 2 is reduced so that the seed crystal 2 and the molten polycrystalline material 101 are re-melted.

[0049] It can be understood that by increasing the power of the coil 4 to heat the material, the temperature of the material can be increased, thereby obtaining more molten polycrystalline material, reducing the moving speed of the polycrystalline material 1 along the first direction Y, and at the same time changing the moving direction of the seed crystal 2 from the first direction Y to the reverse extension direction of the first direction Y, and reducing the rotation speed of the seed crystal 2 to achieve re-melting of the seed crystal 2 and the molten polycrystalline material 101.

[0050] In some embodiments, in the process of remelting the seed crystal 2 with the molten polycrystalline material 101, the power of heating the material is 60-70%, the rotation speed of the polycrystalline material 1 is 1-5rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 0mm / min; the rotation speed of the seed crystal 2 is 5-10rpm / min, and the moving speed of the seed crystal 2 along the reverse extension direction of the first direction Y is 0.1-1mm / min. Specifically, the power of heating the material can be any one of 60%, 62%, 64%, 66%, 68%, and 70%, or a range consisting of any two values; the rotation speed of the polycrystalline material 1 can be any one of 1rpm / min, 1.5rpm / min, 2rpm / min, 2.5rpm / min, 3rpm / min, 3.5rpm / min, 4rpm / min, 4.5rpm / min, and 5rpm / min, or a range consisting of any two values; the rotation speed of the seed crystal 2 can be 5rpm / min, 6rpm / min, 8rpm / min, 9rpm / min, 10rpm / min, 11rpm / min, 12rpm / min, 13rpm / min, 14rpm / min, 15rpm / min, 16rpm / min, 17rpm / min, 18rpm / min, 19rpm / min, 20rpm / min, 21rpm / min, 22rpm / min, 23rpm / min, 24rpm / min, 25rpm / min, 26rpm / min, 27rpm / min, 28rpm / min, 29rpm / min, 30rpm / min, 31rpm / min, 32rpm / min, 33rpm / min, 34rpm / min, 35rpm / min, 36rpm / min, 37rpm / min, 38rpm / min, 39rpm in, 7rpm / min, 8rpm / min, 9rpm / min, 10rpm / min, any one of the values ​​or a range consisting of any two of the values; the moving speed of the seed crystal 2 along the reverse extension direction of the first direction Y can be 0.1mm / min, 0.2mm / min, 0.3mm / min, 0.4mm / min, 0.5mm / min, 0.6mm / min, 0.7mm / min, 0.8mm / min, 0.9mm / min, 1mm / min, any one of the values ​​or a range consisting of any two of the values.

[0051] It can be understood that, in the process of re-melting the seed crystal 2 with the molten polycrystalline material 101, the power of the heated material is set to 60-70%, the rotation speed of the polycrystalline material 1 is set to 1-5 rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 0 mm / min; the rotation speed of the seed crystal 2 is set to 5-10 rpm / min, and the moving speed of the seed crystal 2 along the reverse extension direction of the first direction Y is set to 0.1-1 mm / min, so that the seed crystal 2 and the molten polycrystalline material 101 can be re-melted.

[0052] In some embodiments, before installing the polycrystalline material 1 and the seed crystal 2 into the zone furnace, the zone furnace needs to be dismantled.

[0053] In some embodiments, after the operations of drawing the narrow neck 3, expanding the shoulder, and equalizing the diameter, the process further includes cooling the zone furnace.

[0054] like Figure 2 , Figure 5-Figure 6 As shown, in some embodiments, step S5: when the narrow neck 3 is broken, the narrow neck 3 is heated and melted back to obtain the melted polycrystalline material 102; and the seed crystal 2 and the melted polycrystalline material 102 are re-melted.

[0055] It can be understood that after the narrow neck 3 is broken, the narrow neck 3 is heated and melted back to obtain the melted polycrystalline material 102, and the seed crystal 2 is re-melted with the melted polycrystalline material 102. There is no need to wait for the zone furnace to cool down, dismantle the furnace, replace the seed crystal, and then re-prepare the crystal. This can improve the production efficiency of the crystal and reduce the production cost.

[0056] In some embodiments, when the seed crystal 2 is welded to the molten polycrystalline material 101, the moving direction of the polycrystalline material 1 is the first direction Y, and the step of heating and melting the narrow neck 3 includes:

[0057] The moving direction of the polycrystalline material 1 is changed from the first direction Y to a reverse extension direction of the first direction Y, and the moving speed of the polycrystalline material 1 is reduced;

[0058] The heating power of the heating and melting back is increased to heat and melt back the narrow neck 3 .

[0059] It can be understood that the polycrystalline material 1 is transformed from the first direction Y to move in the opposite extension direction of the first direction Y, while the moving speed of the polycrystalline material 1 is reduced and the heating power of the coil 4 for heating and melting back is increased to achieve heating and melting back of the narrow neck.

[0060] In some embodiments, the step of remelting the seed crystal 2 and the remelted polycrystalline material 102 comprises:

[0061] The moving direction of the seed crystal 2 is changed from the first direction Y to the reverse extension direction of the first direction Y, and the rotation speed of the seed crystal 2 and the moving speed of the seed crystal are reduced;

[0062] The moving speed of the seed crystal 2 is made greater than the moving speed of the polycrystalline material 1 , so that the seed crystal 2 and the remelted polycrystalline material 102 are re-melted.

[0063] It can be understood that the polycrystalline material 1 changes from the first direction Y to the opposite extension direction of the first direction Y, and the seed crystal 2 also changes from the first direction Y to the opposite extension direction of the first direction Y. By making the moving speed of the seed crystal 2 greater than the moving speed of the polycrystalline material 1, the seed crystal 2 and the remelted polycrystalline material 102 can be re-melted.

[0064] In some embodiments, in the process of remelting the seed crystal 2 with the remelted polycrystalline material 102, the heating remelting power is 60-70%, the rotation speed of the polycrystalline material 1 is 1-5 rpm / min, and the moving speed of the polycrystalline material 1 along the reverse extension direction of the first direction Y is 0.1-0.5 mm / min; the rotation speed of the seed crystal 2 is 5-10 rpm / min, and the moving speed of the seed crystal 2 along the reverse extension direction of the first direction Y is 1-1.5 mm / min. Specifically, the power of heating and melting back can be any one of 60%, 62%, 64%, 66%, 68%, and 70%, or a range consisting of any two values; the rotation speed of the polycrystalline material 1 can be any one of 1rpm / min, 1.5rpm / min, 2rpm / min, 2.5rpm / min, 3rpm / min, 3.5rpm / min, 4rpm / min, 4.5rpm / min, and 5rpm / min, or a range consisting of any two values; the moving speed of the polycrystalline material 1 along the reverse extension direction of the first direction Y can be any one of 0.1mm / min, 0.2mm / min, 0.3mm / min, 0.4mm / min, and 0.5mm / min. the rotation speed of the seed crystal 2 can be any one of 5rpm / min, 5.5rpm / min, 6rpm / min, 6.5rpm / min, 7rpm / min, 7.5rpm / min, 8rpm / min, 8.5rpm / min, 9rpm / min, 9.5rpm / min, and 10rpm / min, or a range consisting of any two values; the moving speed of the seed crystal 2 along the reverse extension direction of the first direction Y can be any one of 1mm / min, 1.1mm / min, 1.2mm / min, 1.3mm / min, 1.4mm / min, and 1.5mm / min, or a range consisting of any two values.

[0065] It can be understood that, in the process of remelting the seed crystal 2 and the remelted polycrystalline material 102, the heating remelting power is set to 60-70%, the rotation speed of the polycrystalline material 1 is 1-5rpm / min, and the moving speed of the polycrystalline material 1 along the reverse extension direction of the first direction Y is 0.1-0.5mm / min; the rotation speed of the seed crystal 2 is 5-10rpm / min, and the moving speed of the seed crystal 2 along the reverse extension direction of the first direction Y is 1-1.5mm / min, so that the seed crystal 2 and the remelted polycrystalline material 102 can be remelted.

[0066] In some embodiments, when the seed crystal 2 is welded to the molten polycrystalline material 101, the moving direction of the polycrystalline material 1 is the first direction Y. In the process of heating the polycrystalline material 1 to obtain the molten polycrystalline material 101, the power of heating the material is 50-60%, the rotation speed of the polycrystalline material 1 is 1-5rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 0mm / min; the rotation speed of the seed crystal 2 is 0rpm / min, and the moving speed of the seed crystal 2 along the first direction Y is 0mm / min. Specifically, the power of heating the material can be any one of 50%, 52%, 54%, 56%, 58%, and 60%, or a range consisting of any two values; the rotation speed of the polycrystalline material 1 can be any one of 1rpm / min, 1.5rpm / min, 2rpm / min, 2.5rpm / min, 3rpm / min, 3.5rpm / min, 4rpm / min, 4.5rpm / min, and 5rpm / min, or a range consisting of any two values.

[0067] It can be understood that, in the process of heating and melting the polycrystalline material 1 to obtain the molten polycrystalline material 101, the power of heating the material is 50-60%, the rotation speed of the polycrystalline material 1 is 1-5rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 0mm / min; the rotation speed of the seed crystal 2 is 0rpm / min, and the moving speed of the seed crystal 2 along the first direction Y is 0mm / min, so that the polycrystalline material 1 can be heated and melted.

[0068] In some embodiments, when the seed crystal 2 is welded with the molten polycrystalline material 101, the moving direction of the polycrystalline material 1 is the first direction Y. During the process of drawing the narrow neck 3, the power of heating the molten material is 55-65%, the rotation speed of the polycrystalline material 1 is 1-5 rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 1-2 mm / min; the rotation speed of the seed crystal 2 is 20-30 rpm / min, and the moving speed of the seed crystal 2 along the first direction Y is 12-15 mm / min. Specifically, the power of heating the material can be any one of 55%, 57%, 59%, 61%, 63%, 65%, or a range consisting of any two values; the rotation speed of the polycrystalline material 1 can be any one of 1rpm / min, 1.5rpm / min, 2rpm / min, 2.5rpm / min, 3rpm / min, 3.5rpm / min, 4rpm / min, 4.5rpm / min, 5rpm / min, or a range consisting of any two values; the rotation speed of the seed crystal 2 can be 20rpm / min, 21rpm / min, 22rpm / min, / min, 23rpm / min, 24rpm / min, 25rpm / min, 26rpm / min, 27rpm / min, 28rpm / min, 29rpm / min, 30rpm / min, any one of the values ​​or a range consisting of any two of the values; the moving speed of the seed crystal 2 along the first direction Y can be any one of 12mm / min, 12.5mm / min, 13mm / min, 13.5mm / min, 14mm / min, 14.5mm / min, 15mm / min, any one of the values ​​or a range consisting of any two of the values.

[0069] It can be understood that, in the process of drawing the thin neck 3, the power of heating the material is 55-65%, the rotation speed of the polycrystalline material 1 is 1-5rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 1-2mm / min; the rotation speed of the seed crystal 2 is 20-30rpm / min, and the moving speed of the seed crystal 2 along the first direction Y is 12-15mm / min, so that the thin neck 3 can be drawn.

[0070] In some embodiments, when the seed crystal 2 is welded with the molten polycrystalline material 101, the moving direction of the polycrystalline material 1 is the first direction Y. In the process of welding the seed crystal 2 with the molten polycrystalline material 101, the power of heating the material is 55-65%, the rotation speed of the polycrystalline material 1 is 1-5 rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 0.1-0.5 mm / min; the rotation speed of the seed crystal 2 is 20-30 rpm / min, and the moving speed of the seed crystal 2 along the first direction Y is 0.1-1 mm / min. Specifically, the power of heating the material can be any one of 55%, 57%, 59%, 61%, 63%, 65%, or a range consisting of any two values; the rotation speed of the polycrystalline material 1 can be any one of 1rpm / min, 1.5rpm / min, 2rpm / min, 2.5rpm / min, 3rpm / min, 3.5rpm / min, 4rpm / min, 4.5rpm / min, 5rpm / min, or a range consisting of any two values; the moving speed of the polycrystalline material 1 along the first direction Y can be any one of 0.1mm / min, 0.2mm / min, 0.3mm / min, 0.4mm / min, 0.5mm / min. the rotation speed of the seed crystal 2 can be any one of 20rpm / min, 21rpm / min, 22rpm / min, 23rpm / min, 24rpm / min, 25rpm / min, 26rpm / min, 27rpm / min, 28rpm / min, 29rpm / min, and 30rpm / min, or a range consisting of any two values; the moving speed of the seed crystal 2 along the first direction Y is any one of 0.1mm / min, 0.2mm / min, 0.4mm / min, 0.6mm / min, 0.8mm / min, and 1mm / min, or a range consisting of any two values.

[0071] It can be understood that, in the process of welding the seed crystal 2 with the molten polycrystalline material 101, the power of heating the material is 55-65%, the rotation speed of the polycrystalline material 1 is 1-5rpm / min, and the moving speed of the polycrystalline material 1 along the first direction Y is 0.1-0.5mm / min; the rotation speed of the seed crystal 2 is 20-30rpm / min, and the moving speed of the seed crystal 2 along the first direction Y is 0.1-1mm / min, so that the seed crystal 2 and the molten polycrystalline material 101 can be welded.

[0072] The second aspect of the present application provides a crystal prepared by the above-mentioned crystal preparation method, wherein the oxygen content in the crystal is 0 to 1E16 atom / cm 3 .

[0073] It is understandable that the value of the oxygen content in the crystal (unit: atom / cm 3) can be any value among 0.1, 1, 1E5, 1E10, 1E15, 5E15, 1E16 or a range between any two values. The crystal prepared by the crystal preparation method provided by the present application can meet the above oxygen content value range, and the crystal quality is good.

[0074] The present application will be described below with reference to specific embodiments.

[0075] Example 1

[0076] Installing polycrystalline material 1 and seed crystal 2 into the zone melting furnace;

[0077] The polycrystalline material 1 is moved to above the coil 4 along the first direction Y and then kept still, the heating power of the coil 4 is set to 55%, the rotation speed of the polycrystalline material 1 is set to 3 rpm / min, the rotation speed of the seed crystal 2 is set to 0 rpm / min, the moving speed of the seed crystal 2 along the first direction Y is set to 0 mm / min, the polycrystalline material 1 is heated and melted to obtain a molten polycrystalline material 101;

[0078] After the seed crystal 2 is moved in the reverse extension direction of the first direction Y until the seed crystal 2 contacts the molten polycrystalline material 101, the rotation speed of the seed crystal 2 is 25 rpm / min, the movement speed of the seed crystal 2 in the first direction Y is 0.5 mm / min, the rotation speed of the polycrystalline material 1 is 3 rpm / min, the movement speed of the polycrystalline material 1 in the first direction Y is 0.3 mm / min, and the heating power of the coil 4 is 60%, so that the seed crystal 2 and the molten polycrystalline material 101 are welded;

[0079] When the seed crystal 2 and the molten polycrystalline material 101 fail to be welded, the welding is stopped, the power of the coil 4 for heating the molten material is increased to 65%, and the moving speed of the polycrystalline material 1 along the first direction Y is reduced; the moving speed of the polycrystalline material along the first direction Y is 0 mm / min, and the rotation speed of the polycrystalline material 1 is 3 rpm / min, and the moving direction of the seed crystal 2 is changed from the first direction Y to the reverse extension direction of the first direction Y, and the rotation speed of the seed crystal 2 is reduced to 0.5 mm / min and 8 rpm / min, so that the seed crystal 2 and the molten polycrystalline material 101 are re-welded;

[0080] When the seed crystal 2 is successfully welded to the molten polycrystalline material 101, the moving speed of the seed crystal 2 along the first direction Y is 13 mm / min, the rotation speed of the seed crystal 2 is 25 rpm / min, the moving speed of the polycrystalline material 1 along the first direction Y is 1.5 mm / min, the rotation speed of the polycrystalline material 1 is 3 rpm / min, the heating power of the coil 4 is 60%, and the narrow neck 3 is drawn;

[0081] After shoulder expansion and equal diameter operations, the crystal is obtained.

[0082] The total oxygen content of the prepared crystals was detected by secondary ion mass spectrometry (SIMS). The analysis method was based on the standard ASTM E1078-2009. The oxygen content in each region of the crystal was less than 1E16 atom / cm 3 .

[0083] Example 2

[0084] Installing polycrystalline material 1 and seed crystal 2 into the zone melting furnace;

[0085] The polycrystalline material 1 is moved to above the coil 4 along the first direction Y and then kept still, the heating power of the coil 4 is set to 55%, the rotation speed of the polycrystalline material 1 is set to 3 rpm / min, the rotation speed of the seed crystal 2 is set to 0 rpm / min, the moving speed of the seed crystal 2 along the first direction Y is set to 0 mm / min, the polycrystalline material 1 is heated and melted to obtain a molten polycrystalline material 101;

[0086] After the seed crystal 2 is moved in the reverse extension direction of the first direction Y until the seed crystal 2 contacts the molten polycrystalline material 101, the rotation speed of the seed crystal 2 is 25 rpm / min, the movement speed of the seed crystal 2 in the first direction Y is 0.5 mm / min, the rotation speed of the polycrystalline material 1 is 3 rpm / min, the movement speed of the polycrystalline material 1 in the first direction Y is 0.3 mm / min, and the heating power of the coil 4 is 60%, so that the seed crystal 2 and the molten polycrystalline material 101 are welded;

[0087] When the seed crystal 2 and the molten polycrystalline material 101 fail to be welded, the welding is stopped, the power of the coil 4 for heating the molten material is increased to 65%, and the moving speed of the polycrystalline material 1 along the first direction Y is reduced; the moving speed of the polycrystalline material along the first direction Y is 0 mm / min, and the rotation speed of the polycrystalline material 1 is 3 rpm / min, and the moving direction of the seed crystal 2 is changed from the first direction Y to the reverse extension direction of the first direction Y, and the rotation speed of the seed crystal 2 is reduced to 0.5 mm / min and 8 rpm / min, so that the seed crystal 2 and the molten polycrystalline material 101 are re-welded;

[0088] When the seed crystal 2 is successfully welded to the molten polycrystalline material 101, the moving speed of the seed crystal 2 along the first direction Y is 13 mm / min, the rotation speed of the seed crystal 2 is 25 rpm / min, the moving speed of the polycrystalline material 1 along the first direction Y is 1.5 mm / min, the rotation speed of the polycrystalline material 1 is 3 rpm / min, the heating power of the coil 4 is 60%, and the narrow neck 3 is drawn;

[0089] If the narrow neck 3 is broken, the moving direction of the polycrystalline material 1 is changed from the first direction Y to the reverse extension direction of the first direction Y, and the moving speed of the polycrystalline material 1 is reduced, so that the rotation speed of the polycrystalline material 1 is 3rpm / min, and the moving speed of the polycrystalline material 1 along the reverse extension direction of the first direction Y is 0.3mm / min, the heating power of heating and melting is increased, and the heating and melting power of the coil 4 is 65%, and the moving direction of the seed crystal 2 is changed from the first direction Y to the reverse extension direction of the first direction Y, and the rotation speed and moving speed of the seed crystal 2 are reduced, so that the moving speed of the seed crystal 2 along the reverse extension direction of the first direction Y is 1.3mm / min, and the rotation speed of the seed crystal 2 is 8rpm / min; so that the seed crystal 2 and the remelted polycrystalline material 102 are re-melted;

[0090] After the seed crystal 2 and the remelted polycrystalline material 102 are successfully re-melted, a narrow neck drawing, shoulder expansion and equal diameter operations are performed to obtain a crystal.

[0091] The total oxygen content of the prepared crystals was detected by secondary ion mass spectrometry (SIMS). The analysis method was based on the standard ASTM E1078-2009. The oxygen content in each region of the crystal was less than 1E16 atom / cm 3 .

[0092] The present application provides a method for preparing a crystal, comprising: installing a polycrystalline material 1 and a seed crystal 2 into a zone melting furnace; heating and melting the polycrystalline material 1 to obtain a molten polycrystalline material 101; fusing the seed crystal 2 with the molten polycrystalline material 101; and obtaining a crystal after performing operations such as drawing a thin neck 3, expanding shoulders, and equalizing diameters; wherein, when the seed crystal 2 and the molten polycrystalline material 101 fail to be fused, the fusing is stopped, and after stopping, an operation of increasing the volume of the molten polycrystalline material 101 is performed to re-fuse the seed crystal 2 with the molten polycrystalline material 101; when the thin neck 3 is broken, an operation of heating and remelting the thin neck 3 is performed to obtain a remelted polycrystalline material 102; and the seed crystal 2 and the remelted polycrystalline material 102 are re-fused. The method for preparing the crystal in the present application stops the welding after the welding failure between the seed crystal 2 and the molten polycrystalline material 101, and re-welds the seed crystal 2 and the molten polycrystalline material 101 by increasing the volume of the molten polycrystalline material 101; after the thin neck 3 is broken, the thin neck 3 is heated and remelted to obtain the remelted polycrystalline material 102; the seed crystal 2 and the remelted polycrystalline material 102 are re-melted; there is no need to wait for the zone furnace to cool down, dismantle the furnace to replace the seed crystal 2, and then re-prepare the crystal, which can improve the production efficiency of the crystal and reduce the production cost.

[0093] The above is a detailed introduction to the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for preparing a crystal, characterized in that: include: Installing polycrystalline material (1) and seed crystal (2) into a zone melting furnace; The polycrystalline material (1) is heated to obtain a molten polycrystalline material (101); welding the seed crystal (2) to the molten polycrystalline material (101); After performing the operations of pulling a narrow neck (3), expanding the shoulders, and equalizing the diameter, a crystal is obtained; When the welding of the seed crystal (2) and the molten polycrystalline material (101) fails, the welding is stopped, and after stopping, an operation of increasing the volume of the molten polycrystalline material (101) is performed to re-weld the seed crystal (2) and the molten polycrystalline material (101).

2. The method for preparing a crystal according to claim 1, characterized in that: When the seed crystal (2) is welded to the molten polycrystalline material (101), the moving direction of the polycrystalline material (1) is a first direction (Y), and the volume of the molten polycrystalline material (101) is increased to re-weld the seed crystal (2) to the molten polycrystalline material (101), comprising: Increasing the power of heating the material to increase the volume of the molten polycrystalline material (101); reducing the moving speed of the polycrystalline material (1) along the first direction (Y); The moving direction of the seed crystal (2) is changed from the first direction (Y) to a direction extending in the opposite direction of the first direction (Y), and the rotation speed of the seed crystal (2) is reduced, so that the seed crystal (2) and the molten polycrystalline material (101) are re-melted.

3. The method for preparing a crystal according to claim 2, characterized in that: In the process of remelting the seed crystal (2) and the molten polycrystalline material (101), the power of the heated material is 60-70%, the rotation speed of the polycrystalline material (1) is 1-5 rpm / min, and the moving speed of the polycrystalline material (1) along the first direction (Y) is 0 mm / min; the rotation speed of the seed crystal (2) is 5-10 rpm / min, and the moving speed of the seed crystal (2) along the reverse extension direction of the first direction (Y) is 0.1-1 mm / min.

4. The method for preparing a crystal according to claim 1, characterized in that: When the thin neck (3) is broken, the thin neck (3) is heated and melted back to obtain a melted polycrystalline material (102); The seed crystal (2) and the remelted polycrystalline material (102) are re-melted.

5. The method for preparing a crystal according to claim 4, characterized in that: When the seed crystal (2) is welded to the molten polycrystalline material (101), the moving direction of the polycrystalline material (1) is a first direction (Y), and the step of heating and remelting the narrow neck (3) comprises: The moving direction of the polycrystalline material (1) is changed from a first direction (Y) to a reverse extension direction of the first direction (Y), and the moving speed of the polycrystalline material (1) is reduced; The heating power of the heating and melting back is increased to heat and melt back the narrow neck (3).

6. The method for preparing a crystal according to claim 5, characterized in that: The step of remelting the seed crystal (2) and the remelted polycrystalline material (102) comprises: The moving direction of the seed crystal (2) is changed from the first direction (Y) to a reverse extension direction of the first direction (Y), and the rotation speed of the seed crystal (2) and the moving speed of the seed crystal are reduced; The moving speed of the seed crystal (2) is made greater than the moving speed of the polycrystalline material (1), so that the seed crystal (2) and the remelted polycrystalline material (102) are re-melted.

7. The method for preparing a crystal according to claim 6, characterized in that: In the process of remelting the seed crystal (2) and the remelted polycrystalline material (102), the heating remelting power is 60-70%, the rotation speed of the polycrystalline material (1) is 1-5 rpm / min, and the moving speed of the polycrystalline material (1) in the reverse extension direction of the first direction (Y) is 0.1-0.5 mm / min; the rotation speed of the seed crystal (2) is 5-10 rpm / min, and the moving speed of the seed crystal (2) in the reverse extension direction of the first direction (Y) is 1-1.5 mm / min.

8. The method for preparing a crystal according to claim 1, characterized in that: When the seed crystal (2) is welded to the molten polycrystalline material (101), the moving direction of the polycrystalline material (1) is a first direction (Y); in the process of heating the polycrystalline material (1) to obtain the molten polycrystalline material (101), the power of the heating is 50-60%, the rotation speed of the polycrystalline material (1) is 1-5 rpm / min, and the moving speed of the polycrystalline material (1) along the first direction (Y) is 0 mm / min; the rotation speed of the seed crystal (2) is 0 rpm / min, and the moving speed of the seed crystal (2) along the first direction (Y) is 0 mm / min.

9. The method for preparing a crystal according to claim 1, characterized in that: When the seed crystal (2) is welded to the molten polycrystalline material (101), the moving direction of the polycrystalline material (1) is the first direction (Y). During the process of drawing the narrow neck (3), the power of the heated material is 55-65%, the rotation speed of the polycrystalline material (1) is 1-5 rpm / min, and the moving speed of the polycrystalline material (1) along the first direction (Y) is 1-2 mm / min; the rotation speed of the seed crystal (2) is 20-30 rpm / min, and the moving speed of the seed crystal (2) along the first direction (Y) is 12-15 mm / min.

10. The method for preparing a crystal according to claim 1, characterized in that: When the seed crystal (2) is welded to the molten polycrystalline material (101), the moving direction of the polycrystalline material (1) is a first direction (Y). In the process of welding the seed crystal (2) to the molten polycrystalline material (101), the power of the heated material is 55-65%, the rotation speed of the polycrystalline material (1) is 1-5 rpm / min, and the moving speed of the polycrystalline material (1) along the first direction (Y) is 0.1-0.5 mm / min; the rotation speed of the seed crystal (2) is 20-30 rpm / min, and the moving speed of the seed crystal (2) along the first direction (Y) is 0.1-1 mm / min.

11. A crystal, characterized in that: The crystal is prepared by the method for preparing the crystal according to any one of claims 1 to 10, wherein the oxygen content in the crystal is 0 to 1E16 atom / cm 3 .

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