CN110820043A - Crystal growth apparatus and growth method - Google Patents

Abstract

The invention relates to a crystal growth device, which comprises a quartz furnace, a base, a top cover, a pulling mechanism and a seed crystal; the base and the top cover are respectively fixed on the lower surface and the upper surface of the quartz furnace; the quartz furnace includes a crucible, a heat insulating material covering the crucible, a heater surrounding the crucible, an air inlet pipe, a bellows, a seed rod, and a gas outlet; the crucible has a built-in melt, and the seed crystal is in contact with the liquid surface of the melt The upper part of the thermal insulation material is provided with a first through hole that penetrates up and down, the top cover is provided with a second through hole that penetrates up and down, the bellows is connected between the top cover and the pulling mechanism, the quartz furnace, the top cover, the bellows, the lifting mechanism The mechanisms together form a furnace cavity, the seed rod penetrates the first through hole and the second through hole up and down, and the two ends of the seed rod are respectively connected to the seed crystal and the pulling mechanism; the air intake pipe penetrates the base and communicates with the furnace cavity; the air outlet pipe penetrates through In the top cover, one end of the gas outlet pipe is communicated with the furnace cavity. The invention also relates to a crystal growth method.

Description

Crystal growth apparatus and growth method

technical field

The invention relates to the field of crystal preparation, in particular to a crystal growth device and a growth method.

Background technique

The pulling method, also known as the Chukraski method, is a method of pulling and growing high-quality single crystals from a melt. The process of the pulling method is to heat and melt the raw materials constituting the crystal in a crucible, fuse the seed crystal on the surface of the melt and start pulling, and under certain conditions, the melt gradually solidifies on the solid-liquid interface to grow a single crystal. The pulling method has become the most widely used crystal growth method.

Single crystal pulling furnace is a device for growing crystals by pulling method, which generally consists of furnace cavity, heating system, pulling system, atmosphere control system and other parts. Among them, the furnace cavity is a container for crystal growth and an important part of the single crystal pulling furnace. The furnace cavity plays the role of isolating air and heat radiation. Under normal circumstances, the furnace cavity is made of double-layer stainless steel, and the middle is protected by cooling water. Most single crystal pulling furnaces require openings in the furnace cavity to observe the crystal growth. Due to the complex structure of the furnace cavity, the cost of the single crystal pulling furnace is high, which is not conducive to large-scale production; the cooling circulating water takes away a large amount of heat, which is not conducive to energy saving; because the furnace cavity is welded by stainless steel with a fixed size, the growth of different sizes The crystals need to be customized with different sizes of furnace chambers, resulting in higher additional costs.

Therefore, it is necessary to design a crystal growth apparatus and growth method which can simplify the furnace cavity and reduce the cost.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a crystal growth device and a growth method that simplify the furnace cavity and reduce the cost.

In order to achieve the foregoing purpose, the present invention adopts the following technical solutions: a crystal growth device, the crystal growth device includes a quartz furnace, a base, a top cover, a pulling mechanism and a seed crystal; the base and the top cover are respectively fixed on the lower surface and the upper surface of the quartz furnace; the quartz furnace includes a crucible, an insulating material covering the crucible, a heater surrounding the crucible, an air inlet pipe, a bellows pipe, a seed rod, and an air outlet pipe; the crucible There is a built-in melt, and the seed crystal is connected to the liquid level of the melt; the upper part of the thermal insulation material is provided with a first through hole that penetrates up and down, the top cover is provided with a second through hole that penetrates up and down, and the bellows is connected to the top cover and the puller. Between the mechanisms, the quartz furnace, the top cover, the bellows, and the pulling mechanism together form a furnace cavity, the seed rod penetrates the first through hole and the second through hole up and down, and the two ends of the seed rod are respectively connected to the seed crystal and the second through hole. A lifting mechanism; an air inlet pipe penetrates through the base and communicates with the furnace cavity; an air outlet pipe penetrates through the top cover, and one end of the air outlet pipe is communicated with the furnace cavity.

As a further improvement of the present invention, the upper surface of the base is protruded with a plurality of clamping blocks; the quartz furnace and the base are fixedly connected through the clamping blocks.

As a further improvement of the present invention, a first water inlet pipe and a first water outlet pipe are connected to the base.

As a further improvement of the present invention, a second water inlet pipe and a second water outlet pipe are connected to the top cover.

As a further improvement of the present invention, the crystal growth apparatus further includes a support for supporting the pulling mechanism.

As a further improvement of the present invention, the crystal growth device further includes a liquid tank, the liquid tank contains the absorption liquid, and the other end of the gas outlet pipe is located in the absorption liquid.

As a further improvement of the present invention, the absorbing liquid is water.

The present invention also provides a crystal growth method, which adopts the above crystal growth device, and the crystal growth method comprises the following steps:

S1: furnace loading stage: fix the quartz furnace in the base; put the raw materials into the crucible, and install the heater; install the top cover on the quartz furnace, and insert the gas outlet pipe into the liquid tank containing the absorption liquid; Cooling water is passed from the first water inlet pipe to the base, and cooling water is passed from the second water inlet pipe to the top cover; the cooling water of the base is discharged from the first water outlet pipe; the cooling water of the top cover is discharged from the second water outlet pipe;

S2: Crystal growth stage: the first protective gas is introduced into the furnace cavity from the air inlet pipe; after maintaining for 0.5-2h, the crystal growth program is started, and the second protective gas is introduced into the furnace cavity from the air inlet pipe, and the crystal is seeded as the The foundation begins to grow, and as the crystal grows, the pulling mechanism adjusts the position of the seed rod as needed until the crystal growth is completed.

As a further improvement of the present invention, the first protective gas is argon

As a further improvement of the present invention, the second protective gas is one or a mixture of nitrogen gas and inert gas.

The crystal growth device and growth method of the invention greatly simplifies the structure of the furnace cavity, the same furnace cavity can be used to grow crystals of different sizes, also reduces the cost of crystal growth, and can achieve good crystal growth effect.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the crystal growth apparatus of the present invention.

Detailed ways

The technical solutions will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to FIG. 1 , the present invention provides a crystal growth apparatus, which includes a quartz furnace 1 , a base 2 , a top cover 3 , a pulling mechanism 4 and a seed crystal 5 . The base 2 and the top cover 3 are respectively fixed on the lower surface and the upper surface of the quartz furnace 1 .

The quartz furnace 1 includes a crucible 11 , an insulating material 12 covering the crucible 11 , a heater 13 surrounding the crucible 11 , an air inlet pipe 14 , a bellows 15 , a seed rod 16 , and an air outlet pipe 17 .

The crucible 11 contains a melt 18 , and the seed crystal 5 is in contact with the liquid surface of the melt 18 . The upper part of the thermal insulation material 12 is provided with a first through hole 121 that penetrates up and down, the top cover 3 is provided with a second through hole 33 that penetrates up and down, the bellows 15 is connected between the top cover 3 and the pulling mechanism 4, the quartz furnace 1, the top The cover 3, the bellows 15, and the pulling mechanism 4 together form a furnace cavity 19. The seed rod 16 penetrates the first through hole 121 and the second through hole 33 up and down, and the two ends of the seed rod 16 are respectively connected to the seed crystal 5 and the lifter. Pull Mechanism 4. The air inlet pipe 14 penetrates through the base 2 and communicates with the furnace cavity 19 ;

The centers of the first through hole 121 and the second through hole 33 are located on the same vertical line.

When heating is required, the heater 13 forms a certain thermal field for crystal growth.

A first water inlet pipe 21 and a first water outlet pipe 22 are connected to the base 2 . The first water inlet pipe 21 , the first water outlet pipe 22 and the base 2 can form a cooling water cycle to maintain the base 2 to dissipate heat. The upper surface of the base 2 is protruded with a plurality of clamping blocks 23 . The quartz furnace 1 and the base 2 are fixedly connected by a clamping block 23 .

The top cover 3 is connected with a second water inlet pipe 31 and a second water outlet pipe 32 . The second water inlet pipe 31 , the second water outlet pipe 32 and the top cover 3 can form a cooling water cycle to maintain the top cover 3 to dissipate heat.

The pulling mechanism 4 can adjust the position of the seed rod 16 as required for crystal growth. In some embodiments of the present invention, the crystal growth apparatus further includes a support 7 for supporting the pulling mechanism 4 .

The liquid tank 6 contains the absorption liquid 61, the other end of the gas outlet pipe 17 is located in the absorption liquid 61, and the exhaust gas is absorbed by the absorption liquid and then discharged to avoid environmental pollution. In certain embodiments of the present invention, the absorption liquid is water.

The present invention also relates to a crystal growth method, using the above-mentioned crystal growth device, comprising the following steps:

S1: furnace loading stage: fix the quartz furnace in the base; put the raw materials into the crucible, and install the heater; install the top cover on the quartz furnace, and insert the gas outlet pipe into the liquid tank containing the absorption liquid; Cooling water is introduced into the base from the first water inlet pipe, and the cooling water of the base is discharged from the first water outlet pipe; cooling water is introduced into the top cover from the second water inlet pipe, and the cooling water of the top cover is discharged from the second water outlet pipe;

S2: Crystal growth stage: The first protective gas is introduced into the furnace cavity at a certain flow rate from the air inlet pipe; after maintaining for 0.5-2h, the crystal growth program is started, and the second protective gas is introduced from the air inlet pipe to the furnace cavity at a certain flow rate, and the crystal The growth starts on the basis of the seed crystal. As the crystal grows, the pulling mechanism adjusts the position of the seed crystal rod as required until the crystal growth is completed.

In certain embodiments of the present invention, the first shielding gas is argon. Argon is denser than air and can more easily replace the air in the furnace cavity.

In some embodiments of the present invention, the second protective gas is one or a mixture of nitrogen gas and inert gas. The second protective gas forms a protective atmosphere to facilitate crystal growth.

The crystal growth device and the crystal growth method can be applied to germanium crystal, silicon crystal, bismuth germanate crystal, tellurium dioxide crystal, doped yttrium vanadate crystal, doped gadolinium vanadate crystal, doped lithium niobate crystal, doped Lithium tantalate crystal, doped yttrium aluminum garnet crystal, doped yttrium aluminate crystal, doped lutetium aluminate crystal, doped gadolinium gallium aluminum garnet crystal, doped lutetium aluminum garnet crystal, doped yttrium silicate crystal growth.

Example 1.

Using the above-mentioned crystal growth device, a quartz furnace with an inner diameter of 800mm is fixed to the base and the top cover respectively, and the gas outlet pipe is inserted into the liquid tank containing water; the first water inlet pipe, the first water outlet pipe and the base can form a cooling water circulation Maintain the heat dissipation of the base; the second water inlet pipe, the second water outlet pipe and the top cover can form a cooling water cycle to maintain the top cover to dissipate heat; 15kg doped yttrium silicate crystal material is put into an iridium crucible with a diameter of 160mm, and the zirconia heating is turned on The heating method of the zirconia heater is medium frequency induction heating. Pass 5N argon gas from the air inlet to the bottom of the furnace cavity; after maintaining for 0.5h, turn on the power supply, enter the crystal growth process, and pass a certain flow of 5N nitrogen gas from the air inlet to the bottom of the furnace cavity; the tail gas enters the liquid tank through the gas outlet pipe in and out after being absorbed by water.

During crystal growth, observe the crystal growth through the furnace chamber, and use this as the basis for setting the crystal growth program.

The prepared yttrium lutetium silicate crystal has no defects such as cracking, bubbles, inclusions, and scattering.

Example 2.

Using the above-mentioned crystal growth device, the quartz furnace with an inner diameter of 600mm is fixed to the base and the top cover respectively, and the gas outlet pipe is inserted into the liquid tank containing water; the first water inlet pipe, the first water outlet pipe and the base can form a cooling water circulation Maintain the heat dissipation of the base; the second water inlet pipe, the second water outlet pipe and the top cover can form a cooling water cycle to maintain the top cover to dissipate heat; 8kg doped yttrium aluminum garnet crystal material is put into an iridium crucible with a diameter of 150mm, and the zirconia heating is turned on The heating method of the zirconia heater is medium frequency induction heating. Pass 5N argon gas from the air inlet to the bottom of the furnace cavity; after maintaining for 1 hour, turn on the power supply, enter the crystal growth process, and pass 5N argon gas from the air inlet to the bottom of the furnace cavity; the exhaust gas enters the liquid tank through the gas outlet pipe, and excreted after water absorption.

During crystal growth, observe the crystal growth through the furnace chamber, and use this as the basis for setting the crystal growth program.

The prepared yttrium aluminum garnet crystal has no defects such as cracking, bubbles, inclusions, scattering, etc., the diameter reaches 60 mm, and the equal diameter length is 150 mm, which achieves a good crystal growth effect.

Example 3.

Using the above-mentioned crystal growth device, the quartz furnace with an inner diameter of 600mm is fixed to the base and the top cover respectively, and the gas outlet pipe is inserted into the liquid tank containing water; the first water inlet pipe, the first water outlet pipe and the base can form a cooling water circulation Maintain the heat dissipation of the base; the second water inlet pipe, the second water outlet pipe and the top cover can form a cooling water cycle to maintain heat dissipation of the top cover; put 10kg of germanium crystal raw material into a graphite crucible with a diameter of 100mm, and turn on the zirconia heater; zirconia heating The heating method of the heater is medium frequency induction heating. Pass 5N argon gas from the air inlet to the bottom of the furnace cavity; after maintaining for 2 hours, turn on the power supply, enter the crystal growth process, and pass 5N helium gas from the air inlet to the bottom of the furnace cavity; the exhaust gas enters the liquid tank through the gas outlet pipe, and excreted after water absorption.

During crystal growth, observe the crystal growth through the furnace chamber, and use this as the basis for setting the crystal growth program.

The prepared germanium crystal has no defects such as cracking, bubbles, inclusions, scattering, etc., the diameter reaches 50 mm, and the equal diameter length is 500 mm, which achieves a good crystal growth effect.

The crystal growth device and growth method of the invention greatly simplifies the structure of the furnace cavity, the same furnace cavity can be used to grow crystals of different sizes, also reduces the cost of crystal growth, and can achieve good crystal growth effect.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those of ordinary skill in the art will appreciate that various Improvements, additions and substitutions are possible.

Claims (10)

1. A crystal growth device, characterized in that: the crystal growth device comprises a quartz furnace, a base, a top cover, a pulling mechanism and a seed crystal; the base and the top cover are respectively fixed on the lower surface of the quartz furnace and the upper surface; the quartz furnace includes a crucible, an insulating material covering the crucible, a heater surrounding the crucible, an air inlet pipe, a bellows, a seed rod, and an air outlet pipe; the crucible has a built-in melt, and the seed The crystal is in contact with the liquid level of the melt; the upper part of the thermal insulation material is provided with a first through hole that penetrates up and down, the top cover is provided with a second through hole that penetrates up and down, and the bellows is connected between the top cover and the pulling mechanism. The quartz furnace, the top cover, the bellows and the pulling mechanism together form a furnace cavity, the seed rod penetrates the first through hole and the second through hole up and down, and the two ends of the seed rod are respectively connected to the seed crystal and the pulling mechanism; the air intake pipe It penetrates through the base and communicates with the furnace cavity; the gas outlet pipe penetrates through the top cover, and one end of the gas outlet pipe is communicated with the furnace cavity. 2 . The crystal growth device according to claim 1 , wherein: the upper surface of the base is protruded with a plurality of clamping blocks; the quartz furnace and the base are fixedly connected by the clamping blocks. 3 . 3 . The crystal growth apparatus according to claim 2 , wherein a first water inlet pipe and a first water outlet pipe are connected to the base. 4 . 4. The crystal growth apparatus according to claim 3, wherein a second water inlet pipe and a second water outlet pipe are connected to the top cover. 5 . The crystal growth device according to claim 4 , wherein the crystal growth device further comprises a support for supporting the pulling mechanism. 6 . 6 . The crystal growth device according to claim 5 , wherein the crystal growth device further comprises a liquid tank, the liquid tank contains the absorption liquid, and the other end of the gas outlet pipe is located in the absorption liquid. 7 . 7. The crystal growth apparatus according to claim 6, wherein the absorbing liquid is water. 8. A crystal growth method, using the crystal growth device according to any one of claims 4-7, wherein the crystal growth method comprises the following steps: S1: furnace loading stage: fix the quartz furnace in the base; put the raw materials into the crucible, and install the heater; install the top cover on the quartz furnace, and insert the gas outlet pipe into the liquid tank containing the absorption liquid; Cooling water is passed from the first water inlet pipe to the base, and cooling water is passed from the second water inlet pipe to the top cover; the cooling water of the base is discharged from the first water outlet pipe; the cooling water of the top cover is discharged from the second water outlet pipe; S2: Crystal growth stage: the first protective gas is introduced into the furnace cavity from the air inlet pipe; after maintaining for 0.5-2h, the crystal growth program is started, and the second protective gas is introduced into the furnace cavity from the air inlet pipe, and the crystal is seeded as the The foundation begins to grow, and as the crystal grows, the pulling mechanism adjusts the position of the seed rod as needed until the crystal growth is completed. 9 . The crystal growth method according to claim 8 , wherein the first protective gas is argon. 10 . 10 . The crystal growth method according to claim 8 , wherein the second protective gas is one or a mixture of nitrogen gas and inert gas. 11 .

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