Quartz crucible assembly for indium antimonide crystal growth and growth furnace

Abstract

The utility model provides a quartz crucible assembly for indium antimonide crystal growth and a growth furnace. The quartz crucible assembly comprises a first quartz crucible and a second quartz crucible; the first quartz crucible is provided with an inner cavity with an upward opening and a closed bottom side and peripheral side; the second quartz crucible is in a big-end-down horn shape, is hollow inside, and is opened upwards and downwards; the first quartz crucible is configured to be used for containing an indium antimonide material for growing indium antimonide crystals by a czochralski method at the bottom of the inner cavity; the second quartz crucible is arranged in the first quartz crucible, is positioned on the indium antimonide material of the first quartz crucible and is in contact with the inner circumferential wall of the first quartz crucible at the bottom periphery; the height of the second quartz crucible is 1 / 3-6 / 7 of the height of the inner cavity of the first quartz crucible; the inner diameter of the bottom of the second quartz crucible is 1 / 2-3 / 5 of the inner diameter of the top of the inner cavity of the first quartz crucible; and the inner diameter of the top of the second quartz crucible is 1 / 10-1 / 5 of the inner diameter of the top of the inner cavity of the first quartz crucible.

Description

Technical Field

[0001] The present disclosure relates to the field of crystal growth, and more particularly to a quartz crucible assembly and a growth furnace for growing indium antimonide crystals. Background Art

[0002] Indium antimonide (InSb), as a III-V semiconductor crystal material, has an extremely narrow bandgap, extremely small electron effective mass and extremely high electron mobility, and its physical and chemical properties are stable. Based on these excellent properties, it has been applied in important industrial technology fields such as magnetoresistive elements and Hall devices. It is particularly noteworthy that since InSb has intrinsic absorption in the 3-5μm band, infrared detectors based on InSb have extremely high quantum efficiency and response rate, so InSb has become the preferred material for medium-wave infrared detectors. With the development of a new generation of ultra-large-scale array infrared focal plane devices such as megapixels, in order to reduce the manufacturing cost of detectors and improve production efficiency, the demand for the development of large-size, high-quality InSb crystals is increasing, and large-size InSb crystal growth technology has become the first key issue to be solved. Among them, diameter control technology, dislocation density control technology and electrical parameter control technology all need to be solved in the crystal growth stage.

[0003] Many schemes have been used to improve crystal growth. The core of the three technical problems that need to be solved, namely diameter control, dislocation density and electrical parameters, is the temperature gradient during crystal growth. The temperature gradient causes changes in the crystal growth interface. The crystal growth interface (i.e., the melt surface) directly affects the crystal growth rate. The small faces in the crystal growth interface have a key influence on the stability of electrical parameters. In addition, the thermal stress generated by the temperature gradient is the main driving force for the generation, climb and proliferation of dislocations in the crystal. Therefore, designing a stable and controllable temperature gradient is the key to obtaining large-sized, high-quality indium antimonide crystals.

[0004] In the growth of indium antimonide crystals, indium telluride material is placed in a crucible structure, and indium telluride crystal rods are formed by pulling the indium telluride material from the surface of the melt through the Czochralski method. Crucibles, as the components for holding the melt, are also an aspect of improving the crystal growth temperature field and improving the crystal quality. Therefore, it is necessary to conduct further research on the crucible structure. Utility Model Content

[0005] In view of the problems existing in the background technology, the purpose of the present disclosure is to provide a quartz crucible assembly and a growth furnace for growing indium antimonide crystals, which can reduce the dislocation of the obtained indium antimonide crystals when used for growing indium antimonide crystals, thereby improving the quality of the indium antimonide crystals.

[0006] Therefore, a quartz crucible assembly for growing indium antimonide crystals is provided, the quartz crucible assembly comprising a first quartz crucible and a second quartz crucible; the first quartz crucible has an inner cavity which is open upward and closed at the bottom and the circumference; the second quartz crucible is trumpet-shaped, small at the top and large at the bottom, hollow inside, and open upward and downward; the first quartz crucible is configured to hold indium antimonide material for growing indium antimonide crystals by a Czochralski method at the bottom of the inner cavity; the second quartz crucible is configured to be placed in the first quartz crucible, on the indium antimonide material in the first quartz crucible, and contact the inner peripheral wall of the first quartz crucible at the bottom periphery; the height of the second quartz crucible is 1 / 3-6 / 7 of the height of the inner cavity of the first quartz crucible; the inner diameter of the bottom of the second quartz crucible is 1 / 2-3 / 5 of the inner diameter of the top of the inner cavity of the first quartz crucible; the inner diameter of the top of the second quartz crucible is 1 / 10-1 / 5 of the inner diameter of the top of the inner cavity of the first quartz crucible.

[0007] A growth furnace for growing indium antimonide crystals is provided, the growth furnace comprising a furnace body, a heater, the aforementioned quartz crucible assembly, a seed crystal and a crystal pulling rod; the quartz crucible assembly is supported and fixed in the furnace body; the heater is located in the furnace body, and the heater is used to heat from the outside of a first quartz crucible of the quartz crucible assembly so that the indium antimonide material in the first quartz crucible forms an indium antimonide melt; the seed crystal is fixed to the end of the crystal pulling rod; the crystal pulling rod is arranged in the furnace body, located above the quartz crucible assembly and can reciprocate in the up and down directions, and the crystal pulling rod is configured to drive the seed crystal to move downward into the second quartz crucible of the quartz crucible assembly, immerse into the indium antimonide melt from the surface, and then the crystal pulling rod is pulled upward to vertically grow the indium antimonide crystal to form an indium antimonide crystal rod.

[0008] The beneficial effects of the present disclosure are as follows: when the quartz crucible assembly and the growth furnace for growing indium antimonide crystals are used for growing indium antimonide crystals, the dislocation of the obtained indium antimonide crystals can be reduced, thereby improving the quality of the indium antimonide crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic cross-sectional view of a growth furnace for growing indium antimonide crystals according to the present disclosure.

[0010] Figure 2 is an assembled cross-sectional view of a quartz crucible assembly for growing indium antimonide crystals according to the present disclosure.

[0011] Figure 3 yes Figure 2 Exploded three-dimensional diagram.

[0012] Figure 4 This is the dislocation EPD distribution diagram of the indium antimonide crystal slice of Example 1.

[0013] Figure 5 This is the dislocation EPD distribution diagram of the indium antimonide crystal slice of comparative example 1.

[0014] The description of the accompanying drawings is as follows.

[0015] 100 Growth furnace 311 arc-shaped peripheral wall

[0016] 1 Furnace body 312 flat bottom wall

[0017] 11 top cover 32 second quartz crucible

[0018] 12 Middle Cylinder H2 Height

[0019] 13 Base Db bottom inner diameter

[0020] 2 Heater Dt Top Inner Diameter

[0021] 21 graphite heater 321 arc-shaped peripheral wall

[0022] 22 graphite double layer insulation cover T wall thickness

[0023] 221 inner layer 4 seed crystal

[0024] 222 outer layer 5 crystal pulling rod

[0025] 23 carbon felt 6 vacuum interface

[0026] 3 Quartz crucible assembly 7 Gas inlet

[0027] 31 first quartz crucible 8 bracket

[0028] H1 Lumen Height Screw

[0029] D Inner cavity top inner diameter 200 Indium antimonide material DETAILED DESCRIPTION

[0030] The accompanying drawings show embodiments of the present disclosure, and it will be understood that the disclosed embodiments are merely examples of the present disclosure, and the present disclosure can be implemented in various forms. Therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as the basis for the claims and as a representative basis for teaching ordinary technicians in the field to implement the present disclosure in various ways.

[0031] [Quartz crucible assembly for InSb crystal growth]

[0032] Reference Figure 2 and Figure 3 And cooperate Figure 1 The quartz crucible assembly 3 for growing an indium antimonide crystal according to the present disclosure includes a first quartz crucible 31 and a second quartz crucible 32 .

[0033] The first quartz crucible 31 has an inner cavity which is open upward and closed at the bottom and the circumference. The second quartz crucible 32 is a trumpet-shaped one which is small at the top and large at the bottom, hollow inside, open upward and open downward. The first quartz crucible 31 is configured to hold the indium antimonide material 200 for growing indium antimonide crystals by the Czochralski method at the bottom of the inner cavity. The second quartz crucible 32 is configured to be placed in the first quartz crucible 31, on the indium antimonide material 200 of the first quartz crucible 31, and contact the inner circumference of the first quartz crucible 31 at the bottom periphery. The height H2 of the second quartz crucible 32 is 1 / 3-6 / 7 of the inner cavity height H1 of the first quartz crucible 31; the bottom inner diameter Db of the second quartz crucible 32 is 1 / 2-3 / 5 of the inner diameter D of the top of the inner cavity of the first quartz crucible 31; the top inner diameter Dt of the second quartz crucible 32 is 1 / 10-1 / 5 of the inner diameter D of the top of the inner cavity of the first quartz crucible 31.

[0034] As verified later, when the quartz crucible assembly 3 of the present disclosure is used for growing indium antimonide crystals, it is possible to reduce dislocations of the obtained indium antimonide crystals, thereby improving the quality of the indium antimonide crystals.

[0035] In one example, the first quartz crucible 31 and the second quartz crucible 32 have the same wall thickness, and the wall thickness T is 1 / 140-5 / 140 of the inner diameter D of the top of the inner cavity of the first quartz crucible 31. That is, the first quartz crucible 31 and the second quartz crucible 32 are both thin-walled crucibles.

[0036] In one example, if Figure 3 As shown, the inner cavity of the first quartz crucible 31 is surrounded by an arc-shaped peripheral wall 311 and a flat bottom wall 312; the diameter Dp of the flat bottom wall 312 is 3 / 10-4 / 10 of the inner diameter D of the top of the inner cavity of the first quartz crucible 31. The radius of curvature of the arc-shaped peripheral wall 311 can be determined based on the inner diameter D of the top of the inner cavity of the first quartz crucible 31, the diameter Dp of the flat bottom wall 312 of the first quartz crucible 31, and the inner cavity height H1 of the first quartz crucible 31, as long as the arc-shaped peripheral wall 311 is continuous and smooth.

[0037] In one example, if Figure 3 As shown, the inner cavity of the second quartz crucible 32 is surrounded by an arc-shaped peripheral wall 321. The radius of curvature of the arc-shaped peripheral wall 321 can be determined based on the top inner diameter Dt of the second quartz crucible 32, the bottom inner diameter Db of the second quartz crucible 32, and the height H2 of the second quartz crucible 32, as long as the arc-shaped peripheral wall 321 is continuous and smooth.

[0038] [Growth furnace for growing indium antimonide crystals]

[0039] Reference Figure 1 Combined with Figure 2 and Figure 3The growth furnace 100 for growing indium antimonide crystal according to the present disclosure includes a furnace body 1 , a heater 2 , the aforementioned quartz crucible assembly 3 , a seed crystal 4 , and a crystal pulling rod 5 .

[0040] The quartz crucible assembly 3 is supported and fixed in the furnace body 1. The heater 2 is located in the furnace body 1, and the heater 2 is configured to heat from the outside of the first quartz crucible 31 of the quartz crucible assembly 3 so that the indium antimonide material 200 in the first quartz crucible 31 forms an indium antimonide melt. The seed crystal 4 is fixed to the end of the crystal pulling rod 5. The crystal pulling rod 5 is arranged in the furnace body 1, located above the quartz crucible assembly 3 and can reciprocate in the up and down directions. The crystal pulling rod 5 is configured to drive the seed crystal 4 to move downward into the second quartz crucible 32 of the quartz crucible assembly 3, immerse from the surface of the indium antimonide melt, and then the crystal pulling rod 5 is pulled upward to grow the indium antimonide crystal to form an indium antimonide crystal rod.

[0041] like Figure 1 As shown, the furnace body 1 includes a top cover 11, a middle cylinder 12 and a base 13 which are arranged in sequence from top to bottom. The top cover 11 and the middle cylinder 12 are detachably assembled via screws S, and the middle cylinder 12 and the base 13 are detachably assembled via screws S.

[0042] like Figure 1 As shown, in one example, the heater 2 includes a graphite heater 21, a graphite double-layer heat-insulating cover 22, and a carbon felt 23; the graphite heater 21 is arranged around the first quartz crucible 31, and the graphite double-layer heat-insulating cover 22 is arranged around the graphite heater 21. Further, the graphite double-layer heat-insulating cover 22 includes an inner layer 221 and an outer layer 222; the carbon felt 23 is filled between the inner layer 221 and the outer layer 222 of the graphite double-layer heat-insulating cover 22.

[0043] The description of the structure and effect of the quartz crucible assembly 3 is referred to above and will not be repeated here. In addition, the first quartz crucible 31 is fixed on the bracket 8 during operation, and the bracket 8 is connected to an external rotating mechanism (not shown) and an external lifting mechanism (not shown) so that it can rotate and rise simultaneously during crystal growth, so that the liquid level in the first quartz crucible 31 is within the range heated by the heater 2, and the rotation of the first quartz crucible 31 is opposite to the rotation of the crystal pulling rod 5.

[0044] The seed crystal 4 may be an indium antimonide single crystal with a purity of 7N or higher.

[0045] The crystal pulling rod 5 is connected to a corresponding rotating mechanism (not shown) and a corresponding lifting mechanism (not shown) and can move linearly upward while rotating.

[0046] like Figure 1 As shown, the growth furnace 100 further includes a vacuum extraction interface 6 , which is disposed on the base 13 .

[0047] In addition, refer to Figure 1The growth furnace 100 further includes a gas inlet 7 , which is disposed on the top cover 11 .

[0048] [test]

[0049] Example 1

[0050] Example 1 adopts the following steps:

[0051] S1, loading the indium antimonide material 200 into the first quartz crucible 31 of the growth furnace 100, wherein the purity of the indium antimonide material 200 is 7N, and the amount of the indium antimonide material 200 loaded is such that the top surface of the loaded indium antimonide material 200 does not interfere with the bottom periphery of the second quartz crucible 32 when the second quartz crucible 32 is placed in the first quartz crucible 31, and the structural dimensions of the first quartz crucible 31 are as follows: the inner diameter D of the top of the inner cavity of the first quartz crucible 31 is 25 cm, the inner cavity height H1 of the first quartz crucible 31 is 17.5 cm, the diameter Dp of the flat bottom wall 312 is 7.5 cm, the curvature radius of the arc-shaped peripheral wall 311 is 13.75 cm, and the first quartz crucible 31 has a uniform wall thickness and a thickness of 0.5 cm;

[0052] S2, placing the second quartz crucible 32 into the first quartz crucible 31, wherein the structural dimensions of the second quartz crucible 32 are: the top inner diameter Dt of the second quartz crucible 32 is 3.75 cm, the bottom inner diameter Db of the second quartz crucible 32 is 15 cm, the height H2 of the second quartz crucible 32 is 12.5 cm, the radius of curvature of the arc-shaped peripheral wall 321 is 17.5 cm, and the second quartz crucible 32 has a uniform wall thickness of 0.5 cm;

[0053] S3, evacuating the growth furnace 100, removing gas, and checking for leaks, so that the growth furnace 100 reaches a vacuum, and the vacuum pressure is below 10Pa (monitored by a pressure gauge (not shown)). The evacuation and removal of gas are performed alternately 2-3 times by using a vacuum pump to evacuate the growth furnace 100 and fill the growth furnace 100 with nitrogen. The evacuation interface 6 for evacuation is provided at the bottom of the growth furnace 100, and the removal of gas is performed by using nitrogen through a gas inlet 7 provided at the top of the growth furnace 100.

[0054] S4, after step S3 is completed, the top cover 11 and the middle tube 12 are locked by corresponding screws S, and the middle tube 12 and the base 13 are locked by corresponding screws S, and then the vacuum port 6 and the gas inlet 8 are closed;

[0055] S5, opening the gas inlet 7 again, filling the growth furnace 100 with a nitrogen-hydrogen mixed gas so that the pressure in the growth furnace 100 reaches 0.1 MPa (monitored by a pressure gauge), and then closing the gas inlet 7;

[0056] S6, start heating the first quartz crucible 31, raise the temperature to melt the indium antimonide material 200 in the first quartz crucible 31, wherein the heater 2 includes a graphite heater 21, a graphite double-layer insulation cover 22 and a carbon felt 23, the graphite heater 21 is arranged around the first quartz crucible 31, the graphite double-layer insulation cover 22 is arranged around the graphite heater 21, the carbon felt 33 is filled between the inner layer 221 and the outer layer 222 of the graphite double-layer insulation cover 22, and the heater 2 for heating the first quartz crucible 31 is the only heating device in the growth furnace 100;

[0057] S7, when the indium antimonide material 200 is completely melted to form a melt and the pressure in the growth furnace 100 rises to 0.15 MPa (monitored by a pressure gauge), the temperature of the first quartz crucible 31 is maintained unchanged, wherein the formation of the melt is confirmed by observing through an observation window (not shown) provided in the growth furnace 100;

[0058] S8, after step S7, the crystal pulling rod 5 drives the seed crystal 4 to move downward into the second quartz crucible 32 of the quartz crucible assembly 3, and immerses into the indium antimonide melt from the surface, and then the crystal pulling rod 5 performs vertical pulling upward to grow the indium antimonide crystal to form an indium antimonide crystal rod. During the growth of the indium crystal, the first quartz crucible 31 and the crystal pulling rod 5 maintain opposite rotation speeds, the rotation speed of the first quartz crucible 31 is 1 rpm, the rotation speed of the crystal pulling rod 5 is 3 rpm, and the seed crystal 4 is an indium antimonide single crystal with a purity of 7N;

[0059] S9, after the crystal growth is completed, the heating is stopped, the temperature is lowered, and the gas in the furnace is replaced with nitrogen by the vacuum pump through the vacuum port 6 and the gas inlet 7, and then the growth furnace 100 is opened to cut the crystal rod from the crystal pulling rod 5;

[0060] S10, slicing the crystal rod to perform EPD (Etch pits Density) detection.

[0061] Comparative Example 1

[0062] Except that step S1 does not use the second quartz crucible 32, step S2 is not involved, and in step S8 "the crystal pulling rod 5 drives the seed crystal 4 to move downward into the first quartz crucible 31 of the quartz crucible assembly 3", the rest is the same as embodiment 1.

[0063] Figure 4 1 is a dislocation EPD distribution diagram of an indium antimonide crystal slice of Example 1. Example 1 adds a second quartz crucible 32 on the basis of the first quartz crucible 31. Figure 4 The dislocation EPD distribution diagram shows that the average dislocation of InSb crystal is 17 / cm 2 .

[0064] Figure 5is the dislocation EPD distribution diagram of the indium antimonide crystal slice of Example 1. Comparative Example 1 only uses the first quartz crucible 31 (i.e., without the second quartz crucible 32), based on Figure 5 The dislocation EPD distribution diagram shows that the average dislocation of InSb crystal is 1264 / cm 2 .

[0065] It can be seen that the quartz assembly 3 including the first quartz crucible 31 and the second quartz crucible 32 of the present invention, which have a mutual geometric structure relationship, can significantly reduce the dislocation of the grown indium antimonide crystal. The reason for this is that the inventor of the present application believes that the setting of the second quartz crucible 32 changes the temperature distribution in the first quartz crucible 31, so that the temperature gradient at the solid-liquid interface during the growth of the indium antimonide crystal in the first quartz crucible 31 is reduced, and the thermal stress of the indium antimonide crystal growth is reduced, thereby reducing the generation of dislocations, and the temperature gradient away from the solid-liquid interface is larger than the temperature gradient at the solid-liquid interface, so that the crystallization latent heat generated by the solid-liquid interface is released by the crystal, thereby improving the crystal growth interface and avoiding the generation of dislocations (even a concave interface appears at the solid-liquid interface).

[0066] The above detailed description is used to describe multiple exemplary embodiments, but this document is not intended to be limited to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined together to form multiple additional combinations that are not shown for the sake of simplicity.

Claims

1. A quartz crucible assembly for growing indium antimonide crystals, characterized in that: The quartz crucible assembly (3) comprises a first quartz crucible (31) and a second quartz crucible (32); The first quartz crucible (31) has an inner cavity which is open upward and closed at the bottom and the circumference; The second quartz crucible (32) is in the shape of a trumpet, which is small at the top and large at the bottom, hollow inside, and open upward and downward; The first quartz crucible (31) is configured to hold an indium antimonide material (200) for growing indium antimonide crystals by a Czochralski method at the bottom of the inner cavity; The second quartz crucible (32) is configured to be placed in the first quartz crucible (31), located on the indium antimonide material (200) of the first quartz crucible (31), and contacting the inner peripheral wall of the first quartz crucible (31) at the bottom periphery; The height (H2) of the second quartz crucible (32) is 1 / 3-6 / 7 of the inner cavity height (H1) of the first quartz crucible (31); The inner diameter (Db) of the bottom of the second quartz crucible (32) is 1 / 2-3 / 5 of the inner diameter (D) of the top of the inner cavity of the first quartz crucible (31); The inner diameter (Dt) of the top of the second quartz crucible (32) is 1 / 10-1 / 5 of the inner diameter (D) of the top of the inner cavity of the first quartz crucible (31).

2. The quartz crucible assembly for growing indium antimonide crystals according to claim 1, characterized in that: The first quartz crucible (31) and the second quartz crucible (32) have the same wall thickness, and the wall thickness (T) is 1 / 140-5 / 140 of the inner diameter (D) of the top of the inner cavity of the first quartz crucible (31).

3. The quartz crucible assembly for growing indium antimonide crystals according to claim 1, characterized in that: The inner cavity of the first quartz crucible (31) is surrounded by an arc-shaped peripheral wall (311) and a flat bottom wall (312); The diameter (Dp) of the flat bottom wall (312) is 3 / 10-4 / 10 of the inner diameter (D) of the top of the inner cavity of the first quartz crucible (31).

4. The quartz crucible assembly for growing indium antimonide crystals according to claim 1, characterized in that: The inner cavity of the second quartz crucible (32) is surrounded by an arc-shaped peripheral wall (321).

5. A growth furnace for growing indium antimonide crystals, characterized in that: The growth furnace (100) comprises a furnace body (1), a heater (2), a quartz crucible assembly (3) according to any one of claims 1 to 4, a seed crystal (4), and a crystal pulling rod (5); The quartz crucible assembly (3) is supported and fixed in the furnace body (1); The heater (2) is located in the furnace body (1), and the heater (2) is used to heat the outside of the first quartz crucible (31) of the quartz crucible assembly (3) so that the indium antimonide material (200) in the first quartz crucible (31) forms an indium antimonide melt; The seed crystal (4) is fixed to the end of the crystal pulling rod (5); A crystal pulling rod (5) is arranged on the furnace body (1), located above the quartz crucible assembly (3) and capable of reciprocating in the up and down directions. The crystal pulling rod (5) is configured to drive the seed crystal (4) to move downward into the second quartz crucible (32) of the quartz crucible assembly (3), immerse into the indium antimonide melt from the surface, and then the crystal pulling rod (5) is pulled upward to vertically grow the indium antimonide crystal to form an indium antimonide crystal rod.

6. The growth furnace for growing indium antimonide crystals according to claim 5, characterized in that: The furnace body (1) comprises a top cover (11), a middle tube (12) and a base (13) which are arranged in order from top to bottom. The top cover (11) and the middle cylinder (12) are detachably assembled via screws (S). The middle cylinder (12) and the base (13) are detachably assembled via screws (S).

7. The growth furnace for growing indium antimonide crystals according to claim 6, characterized in that: The growth furnace (100) further comprises a vacuum extraction interface (6). The vacuum extraction interface (6) is arranged on the base (13).

8. The growth furnace for growing indium antimonide crystals according to claim 6, characterized in that: The growth furnace (100) further comprises a gas inlet (7), The gas inlet (7) is arranged on the top cover (11).

9. The growth furnace for growing indium antimonide crystals according to claim 5, characterized in that: The heater (2) comprises a graphite heater (21), a graphite double-layer heat-insulating cover (22) and a carbon felt (23); The graphite heater (21) is arranged around the first quartz crucible (31), and the graphite double-layer heat-insulating cover (22) is arranged around the graphite heater (21).

10. The growth furnace for growing indium antimonide crystals according to claim 9, characterized in that: The graphite double-layer heat-insulating cover (22) comprises an inner layer (221) and an outer layer (222); The carbon felt (23) is filled between the inner layer (221) and the outer layer (222) of the graphite double-layer heat-insulating cover (22).

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