Quartz tube for semiconductor crystal growth

Abstract

The utility model relates to the technical field of semiconductor growth, and discloses a quartz tube for semiconductor crystal growth, which comprises a tube body, one end of the tube body is provided with an opening, the other end of the tube body is provided with a gas delivery tube, the tube body comprises a plurality of tube body units which are coaxially arranged, the tube body units are in the shape of a circular tube, and the gas delivery tube is arranged in the tube body. And the diameters of the plurality of pipe body units are sequentially increased in the direction from the gas conveying pipe to the opening. According to the quartz tube disclosed by the utility model, the tube body is arranged into the plurality of circular tube body units, and the diameters of the plurality of tube body units are sequentially increased in the direction from the gas conveying tube to the opening, so that various crystals with different equal diameters can grow on the same quartz tube, and the production efficiency is improved. Meanwhile, the gas delivery pipe is arranged at the other end of the pipe body, gas can be introduced into the quartz pipe, the pressure in the quartz pipe can be effectively controlled, the phenomena that the quartz pipe is broken and the crucible is crushed due to shrinkage or expansion of the quartz pipe in the crystal growth process are avoided, the crystal yield can be improved, and the production cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor growth, in particular to a quartz tube for semiconductor crystal growth. Background Art

[0002] At present, the main compound semiconductors include gallium arsenide, indium phosphide, silicon carbide, gallium oxide, gallium nitride, sapphire, etc. These compound semiconductors need to grow crystals and then cut into wafers, and become qualified substrates after cutting, grinding and polishing. The growth process of semiconductor crystals, including gallium arsenide crystals and indium phosphide crystals, all use the VGF method (vertical gradient solidification method) for single crystal growth. The VGF method requires a crucible as a carrier, which is then placed in a quartz tube and sealed. The matching of the solid quartz tube and the crucible and the shape of the quartz tube will affect the crystal growth yield.

[0003] However, traditional quartz tubes can only be placed in a crucible of equal diameter to grow a crystal of equal diameter. Moreover, gas cannot be passed into the quartz tube, and the pressure inside the quartz tube cannot be controlled. The quartz tube is prone to shrinkage or expansion during the crystal growth process, causing the quartz tube to crack and crush the crucible, resulting in low crystal yield and high production costs. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a quartz tube for growing semiconductor crystals, which can simultaneously grow crystals of different diameters, improve the crystal yield and reduce production costs.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A quartz tube for semiconductor crystal growth comprises a tube body, one end of which is open and the other end of which is provided with a gas supply pipe. The tube body comprises a plurality of coaxially arranged tube units, each of which is in the shape of a circular tube, and the diameters of the plurality of tube units gradually increase from the gas supply pipe to the opening.

[0007] Preferably, the plurality of tube units and the tube unit and the gas pipe are connected via a tapered connecting section, and the diameter of the connecting section gradually increases in a direction from the gas pipe to the opening.

[0008] Preferably, the angle between the tube wall of the connecting section and the axis of the tube body unit is a, and the value range of a is 45-60°.

[0009] Preferably, the connecting section and the tube body unit, and the connecting section and the gas pipe are both connected through a circular arc transition.

[0010] Preferably, the two adjacent tube units are respectively a first tube unit and a second tube unit, and the diameter of the second tube unit is greater than the diameter of the first tube unit;

[0011] The diameter of the first tube unit is D1, the diameter of the second tube unit is D2, and D2=(1.33-1.5)D1.

[0012] Preferably, the diameter of the pipe unit connected to the gas delivery pipe is 50-150 mm.

[0013] Preferably, the height of the tube unit is 80-100 mm.

[0014] Preferably, a plurality of air inlet pipes are provided at one end of the air delivery pipe away from the pipe body.

[0015] Preferably, the wall thickness of the tube body is 4-6 mm.

[0016] Preferably, the wall thicknesses of the tube units are the same, and the wall thicknesses of the plurality of tube units increase sequentially in a direction from the gas delivery pipe to the opening.

[0017] Compared with the prior art, the quartz tube for semiconductor crystal growth of the embodiment of the utility model has the following beneficial effects: by arranging the tube body into a plurality of coaxially arranged circular tubular tube units, and the diameters of the plurality of tube units are successively enlarged from the gas delivery pipe to the opening, so that the same quartz tube can grow a plurality of crystals of different equal diameters, thereby improving production efficiency. At the same time, by arranging a gas delivery pipe at the other end of the tube body, gas can be introduced into the quartz tube, which can effectively control the pressure in the quartz tube, avoid the phenomenon of the quartz tube breaking and crushing the crucible due to the contraction or expansion of the quartz tube during the crystal growth process, and thus improve the crystal yield rate and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The utility model is a schematic diagram of the structure of a quartz tube for semiconductor crystal growth.

[0019] Figure 2 for Figure 1 A partial enlarged view of middle A.

[0020] Among them: 1-tube body, 11-opening, 12-tube body unit, 13-connecting section, 14-arc section, 2-air delivery pipe, 3-air inlet pipe. DETAILED DESCRIPTION

[0021] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0022] like Figure 1-2 As shown, a quartz tube for semiconductor crystal growth in a preferred embodiment of the utility model comprises a tube body 1, one end of the tube body 1 is open 11, the other end of the tube body 1 is provided with a gas delivery pipe 2, the tube body 1 comprises a plurality of coaxially arranged tube body units 12, the tube body units 12 are circular tube-shaped, and the diameters of the plurality of tube body units 11 are successively larger from the gas delivery pipe 2 to the opening 11. The diameter described in this application refers to the inner diameter, and of course, it can also be understood as the outer diameter.

[0023] The quartz tube for semiconductor crystal growth based on the above characteristics is configured such that the tube body 1 is configured to be a plurality of coaxially arranged circular tubular tube units 12, and the diameters of the plurality of tube units 12 are successively increased from the gas delivery tube 2 to the opening 11, so that the same quartz tube can grow a plurality of crystals of different equal diameters, thereby improving production efficiency. At the same time, by configuring the gas delivery tube 2 at the other end of the tube body 1, gas can be introduced into the quartz tube, which can effectively control the pressure in the quartz tube, avoid the phenomenon of the quartz tube being broken and the crucible being crushed due to the contraction or expansion of the quartz tube during the crystal growth process, and thus improve the crystal yield rate and reduce production costs.

[0024] In this embodiment, the plurality of tube units 12 and the tube unit 12 and the gas pipe 2 are connected by a conical connecting section 13, and the diameter of the connecting section 13 gradually increases from the gas pipe 2 to the opening 11. By setting the conical connecting section 13 to connect tube units 12 of different diameters, the crystals can be smoothly transitioned step by step, and the small diameter crystals can be gradually overgrown into large diameter crystals. This method can improve the yield of the crystals. At the same time, if the angle between the tube wall of the connecting section 13 and the axis of the tube unit 12 is a, the value range of a is 45 to 60°, such as 48°, 50°, 52°, 55°, etc.

[0025] In specific settings, the angles of the tapered connecting sections 13 of different stages of the same crucible may be the same or different. Generally, the angle of the connecting section 13 connecting the tube unit 12 with a larger diameter is smaller than the angle of the connecting section 13 connecting the tube unit 12 with a smaller diameter. The angle of the tapered connecting section 13 will affect the yield of crystal growth. The solid-liquid interface of a crystal with a larger diameter is less affected by the surface tension, so the solid-liquid interface is easily turned into a concave surface, thereby generating twins. Therefore, for a crystal with a larger diameter, the angle of the tapered connecting section 13 becomes smaller, which slows down the rapid formation of the solid-liquid interface, increases the solid-liquid surface tension, forms a convex surface, and reduces the formation of twins.

[0026] In addition, to ensure smoothness of communication, the connection section 13 and the tube unit 12 , as well as the connection section 13 and the gas pipe 2 are transitionally connected via an arc section 14 .

[0027] In this embodiment, the gas pipe 2 is provided with multiple air inlet pipes 3 at one end away from the tube body 1, and can also be a straight tube type single-port gas pipe 2, whose function is to input different gases according to the crystal growth requirements; multiple air inlet pipes 3 are connected to the gas pipe 2 to input multiple gases, while the straight tube type single-port gas pipe 2 can only input one gas.

[0028] In this embodiment, the wall thickness of the tube body 1 is 4-6 mm, such as 4.5 mm, 5 mm, 5.5 mm, etc. In specific configuration, the wall thickness of each tube body unit 12 is the same, and the wall thickness of the plurality of tube body units 12 increases in sequence from the gas delivery pipe 2 to the opening 11. That is, the larger the diameter of the tube body unit 12 of the quartz tube, the thicker the corresponding quartz tube.

[0029] In this embodiment, the two adjacent tube units 12 are respectively the first tube unit and the second tube unit, and the diameter of the second tube unit is greater than the diameter of the first tube unit; specifically, if the diameter of the first tube unit is D1 and the diameter of the second tube unit is D2, then D2 = (1.33-1.5) D1, that is, the diameters of the tube units 12 of equal diameters in each order differ by 66%-75%. At the same time, the diameter of the tube unit 12 connected to the gas delivery pipe 2 is 50-150 mm, such as 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, etc.; the height of the tube unit is 80-100 mm, such as 90 mm, 95 mm, etc.

[0030] The following is an example of two pipe body units 12, and the pipe body unit close to the gas pipe 2 is a first-order equal-diameter portion, the connecting section at the bottom is a first-order cone, and the upper part is connected to the second-order cone; the second-order equal-diameter portion, the bottom is connected to the second-order cone, and the upper part is connected to the third-order cone.

[0031] In a specific embodiment, the first-order cone portion is connected to the gas delivery pipe 2 at the bottom and connected to the first-order equal-diameter portion at the top, and its cone angle (2a) is 90-120°;

[0032] The first-order equal-diameter portion is connected to the first-order conical portion at the bottom and the second-order conical portion at the top, and has a diameter of 50-150 mm, i.e., 2 inches to 6 inches, and a height of 80-100 mm;

[0033] The second-order cone portion is connected to the first-order equal-diameter portion at the bottom and the second-order equal-diameter portion at the top, and its cone angle (2a) is 90-120°;

[0034] The second-order equal-diameter portion is connected to the second-order cone portion at the bottom and the third-order cone portion at the top. Its diameter is 75-200mm, i.e. 13 inches to 8 inches. The diameter of the second-order equal-diameter portion is 1.1313-1.5 times that of the first-order equal-diameter portion; the height is 80-100mm.

[0035] The height of the equal-diameter parts of each level is maintained between 80-100mm. The height of the equal-diameter parts of the same level is related to the angle of the cone of that level. The larger the angle of the cone, the longer the corresponding height of the equal-diameter part, and the smaller the angle of the cone, the shorter the height of the equal-diameter part.

[0036] Two specific embodiments are listed below to illustrate the specific effects of the quartz tube of the present application:

[0037] Embodiment 1:

[0038] 1. The thickness of the quartz tube is 4mm;

[0039] 2. The bottom gas pipe is Y-shaped;

[0040] 13. The first-order cone angle is 115°, the first-order equal-diameter portion has a diameter of 50mm and a height of 100mm;

[0041] 4. The angle of the second-order cone is 115°, the diameter of the second-order equal-diameter part is 76mm, and the height is 100mm;

[0042] Embodiment 2:

[0043] 1. The thickness of the quartz tube is 6mm;

[0044] 2. The bottom gas pipe is a straight pipe type;

[0045] 13. The first-order cone angle is 90°, the first-order equal-diameter portion has a diameter of 150mm and a height of 95mm;

[0046] 4. The angle of the second-order cone is 90°, the diameter of the second-order equal-diameter part is 200mm, and the height is 90mm;

[0047] The above two embodiments are verified by growing gallium arsenide single crystals, and the single crystal yields are as follows:

[0048]

[0049] Judging from the yield rate of gallium arsenide single crystals in the examples, the yield rate of large-diameter crystals is lower than that of small-diameter crystals. This is because the solid-liquid interface of large-diameter crystals is easily transformed into a concave surface due to the reduced surface tension force, thus producing twins. Therefore, for large-diameter crystals, the angle of the cone becomes smaller, which slows down the rapid formation of the solid-liquid interface, increases the solid-liquid surface tension, forms a convex surface, and reduces the formation of twins.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principle of the present invention. These improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A quartz tube for semiconductor crystal growth, characterized in that: The invention comprises a tube body, one end of which is open, and the other end of which is provided with an air delivery pipe, wherein the tube body comprises a plurality of coaxially arranged tube body units, the tube body units are in a circular tube shape, and the diameters of the plurality of tube body units are gradually increased from the air delivery pipe to the opening; The plurality of tube units and the tube unit and the gas pipe are connected by a tapered connecting section, and the diameter of the connecting section gradually increases from the gas pipe to the opening; The angle between the tube wall of the connecting section and the axis of the tube unit is a, and the value range of a is 45 to 60°; The connecting section and the pipe body unit, and the connecting section and the gas pipe are both connected by arc transition; The two adjacent tube units are respectively a first tube unit and a second tube unit, and the diameter of the second tube unit is greater than the diameter of the first tube unit; The diameter of the first tube unit is D1, the diameter of the second tube unit is D2, and D2=(1.33-1.5)D1.

2. The quartz tube for semiconductor crystal growth according to claim 1, characterized in that: The diameter of the pipe unit connected to the gas delivery pipe is 50-150 mm.

3. The quartz tube for semiconductor crystal growth according to claim 1, wherein: The height of the tube unit is 80-100 mm.

4. The quartz tube for semiconductor crystal growth according to claim 1, wherein: A plurality of air inlet pipes are arranged at one end of the air delivery pipe away from the pipe body.

5. The quartz tube for semiconductor crystal growth according to claim 1, wherein: The wall thickness of the tube body is 4-6 mm.

6. The quartz tube for semiconductor crystal growth according to claim 5, characterized in that: The wall thicknesses of the tube units are the same, and the wall thicknesses of the plurality of tube units increase in sequence from the gas delivery pipe to the opening.

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