Twin crystal processing method for growing gallium antimonide by liquid-sealed pulling method

Abstract

The twin crystal treatment method for growing the gallium antimonide by the liquid seal pulling method comprises the following steps: heating and melting a gallium antimonide polycrystal and liquid seal agent powder in a crucible to obtain a gallium antimonide melt covered with a liquid seal agent, clamping a seed crystal by a seed crystal rod, contacting the liquid level of the gallium antimonide melt, slowly lifting the seed crystal rod according to a pulling procedure, and cooling to crystallize the melt on the seed crystal, thereby obtaining the gallium antimonide crystal. Finally, pulling to form a gallium antimonide crystal, and stopping a pulling procedure when a twin crystal area appears on the gallium antimonide crystal; raising the temperature of the gallium antimonide melt by 5-15 DEG C at the temperature raising speed of 0.3-0.5 DEG C / min according to the position of the twin crystal area at the diameter of the gallium antimonide crystal; the seed crystal rod slowly descends at the speed of 10-20 mm / h until the twin crystal area of the gallium antimonide crystal is completely melted, and the seed crystal rod stops descending; the seed crystal rod is continuously and slowly lifted according to the original pulling procedure, and the crucible is continuously cooled according to the original pulling procedure, so that the gallium antimonide crystal is continuously pulled to grow.

Description

Technical Field

[0001] The invention belongs to the field of single crystal growth, and in particular relates to a twin crystal processing method for growing gallium antimonide by a liquid-sealed Czochralski method. Background Art

[0002] In recent years, antimonide infrared technology has developed rapidly, becoming a key development direction in semiconductor technology. Gallium antimonide, a typical III-V compound semiconductor, has become a key substrate material for antimonide infrared optoelectronic devices due to its excellent performance. Currently, the liquid-enclosed Czochralski (LEC) method is commonly used to grow GaSb single crystals in industry. Compared to silicon, germanium, and other crystals, GaSb has a lower stacking fault energy. Therefore, twinning is common in GaSb crystals grown using the LEC method. When growing semiconductor single crystals using the Czochralski method, once twins appear, the crystal must be melted down to a seed crystal and then regrown with necking and shouldering to prevent an increase in defect density. This prolongs the single crystal growth time and significantly reduces single crystal growth efficiency. Therefore, while ensuring single crystal quality, a new twinning treatment method for GaSb grown using the LEC method is proposed to prevent complete remelting of twinned GaSb crystals. This approach is of great significance for improving single crystal growth efficiency and reducing production costs. Summary of the Invention

[0003] In view of the problems existing in the background technology, the invention object of the present application is to provide a twinning treatment method for gallium antimonide grown by a liquid-sealed Czochralski method.

[0004] To achieve the above objectives, the present invention adopts the following specific technical solutions.

[0005] The present invention provides a method for processing twins of gallium antimonide grown by a liquid-sealed Czochralski method, comprising: heating and melting gallium antimonide polycrystals and liquid sealing agent powder in a crucible to obtain a gallium antimonide melt covered with the liquid sealing agent; clamping the seed crystal with a seed crystal rod and contacting the liquid surface of the gallium antimonide melt; slowly raising the seed crystal rod and cooling it according to a pulling procedure to allow the gallium antimonide melt to crystallize on the seed crystal; and finally pulling to form a gallium antimonide crystal. During the pulling process, when a twin region is found on the gallium antimonide crystal, the following steps are performed:

[0006] (1) Stop the lifting process

[0007] When twin regions are found on the GaSb crystal, the above pulling process is stopped;

[0008] (2) Raising the temperature of the gallium antimonide melt

[0009] The temperature of the GaSb melt is raised by 5-15°C at a heating rate of 0.3-0.5°C / min, depending on the diameter of the twin region in the GaSb crystal.

[0010] (3) The seed crystal rod slowly descends

[0011] The seed crystal rod slowly descends at a speed of 10-20 mm / h until the twin regions of the GaSb crystal are completely melted, and then the seed crystal rod stops descending;

[0012] (4) Continue the original pulling process

[0013] The seed crystal rod continues to be slowly raised according to the original pulling procedure, and the crucible continues to be cooled according to the original pulling procedure, so that the gallium antimonide crystal continues to be pulled and grown.

[0014] The present invention provides a twinning method for growing gallium antimonide by a liquid-sealed Czochralski method, wherein: the growth direction of the gallium antimonide crystal includes <100> and <111> direction.

[0015] The twinning treatment method for growing gallium antimonide by the liquid-sealed Czochralski method of the present invention has the following beneficial effects:

[0016] 1. The twinning treatment method for growing GaSb by the liquid-sealed Czochralski method of the present invention can give full play to the advantage of visible growth of the liquid-sealed Czochralski method. When twins appear in the GaSb crystal during its growth, it is only necessary to melt back the region where the twins appear, without melting back the crystal to the seed crystal. This effectively shortens the single crystal growth time, improves the single crystal growth efficiency, and reduces costs.

[0017] 2. After re-melting and growth, the dislocation density of the single crystal does not increase significantly, ensuring the quality of the single crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a cross-sectional schematic diagram of the equipment used in the gallium antimonide processing process of the present invention;

[0019] Figure 2 FIG2 is a perspective schematic diagram of an apparatus used in the gallium antimonide processing process of the present invention, with the front of the apparatus cut away for clarity;

[0020] Figure 3 The 3-inch twin crystal processing method for growing gallium antimonide by the liquid sealing pulling method of the present invention is prepared <100> Photo of a single crystal of gallium antimonide;

[0021] Figure 4 : is a distribution diagram of the number of dislocation corrosion pits of the grown GaSb crystal before welding using the method of the present invention;

[0022] Figure 5 The figure is a distribution diagram of the number of dislocation corrosion pits of the grown GaSb crystal after re-welding according to the method of the present invention.

[0023] exist Figures 1 to 2In the figure, number 1 is a crucible; number 2 is a seed crystal; number 3 is a seed crystal rod; number 4 is a gallium antimonide crystal; number 5 is a gallium antimonide melt; number 6 is an outer shell; number 7 is a heater; number 8 is an insulation layer; number 9 is a crucible rod; number 10 is a twin region; and number 11 is a liquid sealant. DETAILED DESCRIPTION

[0024] The method for growing gallium antimonide by the liquid-sealed Czochralski method of the present invention is Figure 1 and Figure 2 The process is carried out in a device comprising a crucible 1, a seed crystal rod 3, a housing 6, a heater 7, an insulating layer 8 and a crucible rod 9. The crucible 1 is supported by the crucible rod 9, the crucible 1 is placed in the heater 7, the insulating layer 8 is placed in the heater 7, the seed crystal rod 3 is mounted above the crucible 1 and holds the seed crystal 2.

[0025] like Figure 1 and Figure 2 The method for growing gallium antimonide by the liquid-sealed pulling method of the present invention comprises: heating and melting gallium antimonide polycrystals and liquid sealing agent powder in a crucible 1 to obtain a gallium antimonide melt 5 covered with a liquid sealing agent 11, a seed crystal rod 3 clamping a seed crystal 2 and contacting the liquid surface of the gallium antimonide melt 5, slowly lifting the seed crystal rod 3 and cooling it according to a pulling procedure, so that the gallium antimonide melt 5 crystallizes on the seed crystal 2, and finally pulling to form a gallium antimonide crystal 4.

[0026] During the pulling process, when a twin region 10 is found on the GaSb crystal 4, the following steps are taken:

[0027] (1) Stop the lifting process

[0028] When a twin region 10 is found on the GaSb crystal 4, the pulling process is stopped.

[0029] (2) Raising the temperature of the gallium antimonide melt 5

[0030] The twin region 10 appears at a diameter of 40 mm on the GaSb crystal 4. The temperature of the GaSb melt 5 is increased by 8°C at a heating rate of 0.5°C / min.

[0031] (3) Seed rod 3 slowly descends

[0032] The seed rod 3 is slowly lowered at a speed of 10 mm / h until the twin regions 10 of the gallium antimonide crystal 4 are completely melted, and then the seed rod 3 stops lowering;

[0033] (4) Continue the original pulling process

[0034] The seed rod 3 continues to rise slowly according to the original pulling procedure, and the crucible 1 continues to cool down according to the original pulling procedure, so that the GaSb crystal 4 continues to grow. The growth direction of the GaSb crystal 4 is <100> direction.

[0035] Figure 3 The 3-inch <100> Photo of a gallium antimonide single crystal.

[0036] According to GJB 10343-2021 Measurement Method for Dislocation Density of Polished Gallium Antimonide Single Crystal Wafers, the dislocation density of gallium antimonide wafers before and after welding was tested. The diameter of the wafer before welding was about 30mm, and the diameter of the wafer after re-welding was about 40mm. The test results are as follows: Figure 4 and 5 The test results show that: compared with the pre-welding Figure 4 ), after re-welding ( Figure 5 )-grown GaSb crystals showed no obvious dislocation proliferation.

[0037] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the present invention to only the specific implementation methods described. Obviously, many modifications and variations can be made based on the contents of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for processing twin crystals of gallium antimonide grown by a liquid-sealed Czochralski method, comprising: GaSb polycrystals and liquid sealing agent powder are heated and melted in a crucible (1) to obtain a GaSb melt (5) covered with a liquid sealing agent (11); a seed crystal rod (3) clamps the seed crystal (2) and contacts the liquid surface of the GaSb melt (5); the seed crystal rod (3) is slowly lifted and cooled according to a pulling procedure to allow the GaSb melt (5) to crystallize on the seed crystal (2); and finally, the GaSb crystal (4) is pulled to form the GaSb crystal. The method is characterized in that: during the pulling process, when a twin region (10) is found on the GaSb crystal (4), the following steps are adopted: (1) Stop the lifting process When a twin region (10) is found on the gallium antimonide crystal (4), the pulling process is stopped; (2) Raising the temperature of the gallium antimonide melt (5) According to the diameter position of the twin region (10) at the gallium antimonide crystal (4), the temperature of the gallium antimonide melt (5) is increased by 5-15°C at a heating rate of 0.3-0.5°C / min; (3) The seed crystal rod (3) slowly descends The seed crystal rod (3) slowly descends at a speed of 10-20 mm / h until the twin region (10) of the gallium antimonide crystal (4) is completely melted, and then the seed crystal rod (3) stops descending; (4) Continue the original pulling process The seed crystal rod (3) continues to be slowly raised according to the original pulling procedure, and the crucible (1) continues to be cooled according to the original pulling procedure, so that the gallium antimonide crystal (4) continues to be pulled and grown.

2. The twinning treatment method for gallium antimonide grown by the liquid-sealed Czochralski method according to claim 1, characterized in that: The growth direction of the gallium antimonide crystal (4) includes <100> and <111> direction.

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