阅读说明：本技术 一种高纯碲化镓的制备方法及装置 (Preparation method and device of high-purity gallium telluride ) 是由 李镇宏 朱刘 狄聚青 周亚明 劳秀钱 陈超辉 于 2021-08-18 设计创作，主要内容包括：本发明属于半导体材料制备领域,公开了一种高纯碲化镓的制备方法及装置,所述制备方法包括以下步骤：S1.将碲和镓混合装入坩埚舟中；S2.将步骤S1中坩埚舟置于石英管中,保持石英管内氮气/氢气氛围；S3.控制加热器,使石英管整体升温,使碲和镓进行反应；S4.控制加热器,从石英管一端开始至另一端,将石英管依次分成若干小段,控制加热器,依次进行降温至中间段温度；S5.控制加热器,使石英管整体降温至室温,取出石英管内坩埚舟,得高纯碲化镓。本发明所述高纯碲化镓的制备方法工序简单、效率高,且制备得到的碲化镓性能良好,纯度较高,无气泡、夹杂等缺陷,重复率较高,合格成品率达80～90%。(The invention belongs to the field of semiconductor material preparation, and discloses a preparation method and a device of high-purity gallium telluride, wherein the preparation method comprises the following steps: s1, mixing tellurium and gallium and loading the mixture into a crucible boat; s2, placing the crucible boat in the step S1 in a quartz tube, and keeping the nitrogen/hydrogen atmosphere in the quartz tube; s3, controlling the heater to integrally heat the quartz tube so as to react the tellurium and the gallium; s4, controlling a heater, sequentially dividing the quartz tube into a plurality of small sections from one end of the quartz tube to the other end of the quartz tube, and controlling the heater to sequentially cool the quartz tube to the temperature of the middle section; s5, controlling the heater to integrally cool the quartz tube to room temperature, and taking out the crucible boat in the quartz tube to obtain the high-purity gallium telluride. The preparation method of the high-purity gallium telluride is simple in process and high in efficiency, the prepared gallium telluride is good in performance, high in purity, free of defects such as bubbles and inclusions, high in repetition rate and high in qualified finished product rate of 80-90%.)

1. The preparation method of the high-purity gallium telluride is characterized by comprising the following steps:

s1, mixing tellurium and gallium according to a specified molar ratio, wherein tellurium is excessive relative to gallium, and loading the mixed material into a crucible boat;

s2, placing the crucible boat in the quartz tube in the step S1, placing the quartz tube in a heater, exhausting air in the quartz tube, and keeping the atmosphere of nitrogen and hydrogen in the quartz tube;

s3, controlling a heater to enable the whole quartz tube to be heated to 850-1000 ℃ at a first heating rate, and preserving heat for a period of time to enable tellurium and gallium to react;

s4, controlling the heater, starting to the other end from quartz capsule one end, divide into a plurality of segments with the quartz capsule in proper order, control the heater, every section of quartz capsule is cooled down to target temperature 550~620 ℃ with first cooling rate in proper order, specifically is: the temperature of the former section is kept after reaching the target temperature, and the temperature of the latter section is kept until reaching the target temperature of the last section;

s5, controlling the heater to enable the whole quartz tube to be cooled to the room temperature at a second cooling rate, stopping introducing nitrogen and hydrogen, stopping heating, and taking out the crucible boat in the quartz tube to obtain the high-purity gallium telluride.

2. The method of claim 1, wherein in step S1, the tellurium is 7N tellurium and the gallium is 7N gallium.

3. The method for producing high-purity gallium telluride according to claim 1 or 2, wherein in step S1, the prescribed molar ratio of tellurium to gallium is 1.002 to 1.005: 1.

4. the method according to claim 1, wherein in step S2, a mixed gas of hydrogen and nitrogen having a hydrogen concentration of 20 to 30% is kept as a shielding gas.

5. The method according to claim 1, wherein in step S3, the first temperature rise rate is 200-500 ℃/h.

6. The method according to claim 1, wherein in step S4, the first temperature reduction rate is 30-50 ℃/h.

7. The method for preparing high-purity gallium telluride as in claim 1 or 6, wherein in step S4, after the final stage reaches the target temperature and the temperature is kept, the temperature of the heater is controlled and kept constant for 1-2 h.

8. The method for preparing high-purity gallium telluride as claimed in claim 1, wherein in the step S5, the second temperature reduction rate is 60-80 ℃/h.

9. The device for preparing the high-purity gallium telluride is characterized by comprising a quartz tube, a crucible boat placed in the quartz tube and a heater arranged around the wall of the quartz tube.

10. The apparatus according to claim 9, wherein the heater comprises a plurality of independently controlled heating elements, each of which is sequentially fitted over the wall of the quartz tube at a predetermined interval.

Technical Field

The invention belongs to the field of semiconductor material preparation, and particularly relates to a preparation method and a device of high-purity gallium telluride.

Background

Gallium telluride is an important doped material, is widely applied to the growth of antimonide single crystals, and can greatly improve the electrical property of the antimonide single crystals and reduce dislocation. The use of high purity gallium telluride as a dopant contributes to the production of antimonide single crystals of superior performance.

At present, the preparation method of gallium telluride mainly uses the traditional VB method, the cost of equipment and time required by preparation is relatively high, the production efficiency is low, and impurities are not easy to discharge by the VB method, so that the purity of the product is not high, and the product performance is reduced.

Disclosure of Invention

In view of the above problems in the prior art, an object of the present invention is to provide a method for preparing high-purity gallium telluride, which has the advantages of simple process, high efficiency, good performance of the prepared gallium telluride, high purity, and no defects such as bubbles and inclusions.

The invention also aims to provide a preparation device of high-purity gallium telluride.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a preparation method of high-purity gallium telluride comprises the following steps:

s1, mixing tellurium and gallium according to a specified molar ratio, wherein tellurium is excessive relative to gallium, and filling the mixed material into a crucible boat.

S2, placing the crucible boat in the quartz tube in the step S1, placing the quartz tube in a heater, exhausting air in the quartz tube, continuously introducing nitrogen and hydrogen as protective gases, and keeping the nitrogen/hydrogen atmosphere in the quartz tube.

And S3, controlling the heater to heat the whole quartz tube to 850-1000 ℃ at a first heating rate, and preserving the temperature for a period of time to react the tellurium and the gallium.

S4, controlling the heater, starting to the other end from quartz capsule one end, divide into a plurality of segments with the quartz capsule in proper order, controlling the heater, cooling to target temperature 550~620 ℃ with first cooling rate in proper order, specifically be: the temperature of the former section is kept after reaching the target temperature, and the temperature of the latter section is kept until reaching the target temperature of the last section; in the solidification process, impurities with the segregation coefficient smaller than 1 are concentrated in the backward solidification part, and impurities with the segregation coefficient larger than 1 are concentrated in the early solidification part. The middle section is high-purity material with low impurity.

And S5, controlling the heater to enable the whole quartz tube to be cooled to the room temperature at a second cooling rate. Stopping introducing nitrogen and hydrogen, stopping heating, taking out the crucible boat in the quartz tube, and removing the parts with high impurities at the head and the tail, wherein the middle section is the required high-purity gallium telluride.

Further, in step S1, the tellurium is 7N tellurium, and the gallium is 7N gallium.

Further, in step S1, the predetermined molar ratio of tellurium to gallium is 1.002 to 1.005: 1.

further, in step S2, the atmosphere in the quartz tube is exhausted so that nitrogen gas is introduced into the quartz tube.

Further, in step S2, the introduced gas is 5N of high purity gas. The gas keeps flowing in the quartz tube, the two ends of the quartz tube are connected and sealed by adopting metal flanges, the tail end of the quartz tube is provided with a solid particle filtering device, and the gas finally enters the tail gas absorption tank and is discharged.

Further, in the steps S3, S4 and S5, the hydrogen and nitrogen mixed gas with the hydrogen concentration of 20-30% is kept as the protective gas, so that the oxygen content in the quartz tube can be greatly reduced, the material oxidation is avoided, and the purity of the product is further improved.

Further, in step S3, the first temperature rise rate is 200 to 500 ℃/h.

Furthermore, the temperature of the melt is kept for 1-2 hours after the temperature is raised to 750-820 ℃, so that the temperature of the melt is uniform, and the melt is fully melted and mixed.

Further, in step S4, the first cooling rate is 30 to 50 ℃/h.

Further, in step S4, the temperature is decreased to the target temperature of 600 ℃ at the first temperature decrease rate.

In the invention, the temperature is reduced at the temperature reduction rate of 30-50 ℃/h in sequence, and impurities are effectively removed by the temperature gradient and the temperature reduction rate, so that the gallium telluride with higher purity is obtained.

Further, in step S4, after the last section reaches the target temperature and then the temperature is kept, the heater is controlled to keep the temperature for 1-2 hours.

Further, in step S5, the second cooling rate is 60 to 80 ℃/h. Too fast a temperature decrease during step S5 may cause thermal stress concentration, resulting in cracking of the quartz boat and the gallium telluride. Too slow will influence production efficiency, and this cooling rate is comparatively moderate, satisfies the production requirement of quality and efficiency.

In the invention, after the step S4 is finished, the temperature is kept for 1-2 h, the temperature inside the crystal is balanced, and then the crystal enters a cooling stage, wherein the cooling rate is 60-80 ℃/h, and the cooling rate can reduce the pressure stress between the crystal and the quartz boat caused by different thermal expansion coefficients, thereby avoiding the crystal cracking and the quartz boat crushing.

The invention also discloses a preparation device of the high-purity gallium telluride, which comprises a quartz tube, a crucible boat arranged in the quartz tube and a heater arranged around the wall of the quartz tube.

Furthermore, the heater comprises a plurality of independently controlled heating elements, and each heating element is sequentially sleeved outside the wall of the quartz tube at a certain interval.

Compared with the prior art, the invention has the beneficial effects that:

(1) the preparation method of the high-purity gallium telluride is simple in process and high in efficiency, the prepared gallium telluride is good in performance, high in purity, free of defects such as bubbles and inclusions, high in repetition rate and high in qualified finished product rate of 80-90%.

(2) The preparation method of high-purity gallium telluride has the advantages of short production flow, large treatment capacity, realization of industrialization, popularization of the method and remarkable economic benefit.

(3) The preparation method of the high-purity gallium telluride adopts a production mode of flowing protective gas flow in the resynthesis reaction process, and the designed device has simple structure requirement and lower cost.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus for producing high-purity gallium telluride in example 1 of the present invention.

Detailed Description

In order to facilitate an understanding of the invention, the invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

Example 1

As shown in fig. 1, the embodiment discloses a high-purity gallium telluride preparing apparatus, which includes a quartz tube 110, a quartz boat 120 disposed in the quartz tube 110, and a set of heaters 130 disposed around the tube wall of the quartz tube 110, wherein the heaters 130 include 9 independently controlled heating elements 131, and the 9 heating elements are sequentially sleeved outside the tube wall of the whole quartz tube at intervals of 20 mm.

Example 2

This example discloses a method for preparing high-purity gallium telluride, using the apparatus as described in example 1, comprising the following steps:

s1, selecting 7N high-purity tellurium and 7N high-purity gallium with the total weight of 3kg, wherein the molar ratio is 1.003: 1 weighing the materials, putting the materials into a quartz boat, and uniformly mixing the materials to form a uniformly mixed material;

s2, placing the quartz boat in the middle section of the quartz tube in the step S1, placing the quartz tube in a heater, introducing 5N nitrogen into the quartz tube to replace air in the quartz tube, keeping for 20min, and introducing 5N hydrogen into the quartz tube to control the hydrogen concentration to be 20%;

s3, controlling a heater, heating all the heating elements to 1000 ℃ at a speed of 250 ℃/h, keeping the temperature for 1h, and heating and melting the high-purity raw materials to obtain a gallium telluride melt;

s4, controlling a heater to sequentially cool the heating body to 600 ℃ from beginning to end at a cooling rate of 40 ℃/h, namely: keeping the temperature of the former heating element after reaching the target temperature of 600 ℃, and cooling the latter heating element until the last heating element is cooled, and when the temperature of the last heating element reaches 600 ℃, completing the whole solidification process, and keeping the temperature of 600 ℃ for 1.5 hours;

s5, controlling the heater to enable all the heating bodies to start to cool to room temperature at the same cooling rate of 80 ℃/h, stopping ventilation and heating, and taking out the quartz boat and the gallium telluride in the quartz boat after all mixed gas is removed. The obtained gallium telluride is analyzed after head and tail removal, and the product purity is 6N and has no defects such as air holes, cracks and the like.

Comparative example 1

This comparative example is substantially the same as example 2 except for the differences in S4 and S5.

In the comparative example, S4/S5 is combined as one step, specifically: controlling the heater to enable all the heating bodies to start to cool to room temperature at the same cooling rate of 80 ℃/h, stopping ventilation and heating, and taking out the quartz boat and gallium telluride in the quartz boat after all mixed gas is removed. When the quartz boat is discharged, the quartz boat is broken, and the obtained gallium telluride has obvious cracks and fine cracks. After the head and the tail are removed, the product has more impurities and the purity of 5N.

Example 3

As shown in fig. 1, the embodiment discloses a high-purity gallium telluride preparing apparatus, which includes a quartz tube 110, a quartz boat 120 disposed in the quartz tube 110, and a set of heaters 130 disposed around the tube wall of the quartz tube 110, wherein the heaters 130 include 7 independently controlled heating elements 131, and the 7 heating elements are sequentially sleeved outside the tube wall of the whole quartz tube at intervals of 20 mm.

Example 4

This example discloses a method for preparing high-purity gallium telluride using the apparatus as described in example 3, comprising the steps of:

s1, selecting 7N high-purity tellurium and 7N high-purity gallium with the total weight of 5kg, wherein the molar ratio is 1.003: 1 weighing the materials, putting the materials into a quartz boat, and uniformly mixing the materials to form a uniformly mixed material;

s2, placing the quartz boat in the middle section of the quartz tube in the step S1, placing the quartz tube in a heater, introducing nitrogen into the quartz tube to replace air in the quartz tube, keeping for 30min, and introducing hydrogen into the quartz tube to control the concentration of the hydrogen to be 30%;

s3, controlling a heater, heating all the heating elements to 1000 ℃ at a speed of 350 ℃/h, keeping the temperature for 1.5h, and heating and melting the high-purity raw materials to obtain a gallium telluride melt;

s4, controlling a heater to sequentially cool the heating body to 600 ℃ from beginning to end at a cooling rate of 30 ℃/h, namely: keeping the temperature of the former heating element after reaching the target temperature of 600 ℃, and cooling the latter heating element until the last heating element is cooled, and when the temperature of the last heating element reaches 600 ℃, completing the whole solidification process, and keeping the temperature of 600 ℃ for 1 h;

s5, controlling the heater to enable all the heating bodies to start to cool to room temperature at the same cooling rate of 60 ℃/h, stopping ventilation and heating, and taking out the quartz boat and the gallium telluride in the quartz boat after all mixed gas is removed. The obtained gallium telluride is analyzed after head and tail removal, and the product purity is 6N and has no defects such as air holes, cracks and the like.

Comparative example 2

This comparative example is substantially the same as example 4 except for the differences in S4 and S5.

In the comparative example, S4/S5 is combined as one step, specifically: controlling the heater to enable all the heating bodies to start to cool to room temperature at the same cooling rate of 60 ℃/h, stopping ventilation and heating, and taking out the quartz boat and gallium telluride in the quartz boat after all mixed gas is removed. The obtained gallium telluride has obvious cracking and fine cracks. After the head and the tail are removed, the product has more impurities and the purity of 5N.

Comparative example 3

This comparative example is substantially the same as example 4 except for the difference at S2.

The method specifically comprises the following steps: and (5) placing the quartz boat in the middle section of the quartz tube in the step S1, placing the quartz tube in a heater, introducing 5N nitrogen into the quartz tube to replace air in the quartz tube, keeping for 20min, and introducing 5N hydrogen into the quartz tube, wherein the concentration of the hydrogen is controlled to be 10%.

The purity of the product of the gallium telluride finally obtained by the comparative example is 5.5N after head and tail removal, wherein the content of As and Pb elements is higher, and the product has no defects such As air holes, cracks and the like.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.