阅读说明：本技术 一种砷化镓多晶的制备方法 (Preparation method of gallium arsenide polycrystal ) 是由 罗小龙 周铁军 易明辉 曾国治 于 2021-08-17 设计创作，主要内容包括：本发明提供了一种砷化镓多晶的制备方法,涉及多晶合成技术领域。本发明提供的砷化镓多晶的制备方法包括如下步骤：(1)将单质砷、单质镓置于真空装置炉中,炉内抽真空；(2)将所述真空装置炉的炉温升温至第一目标温度；(3)将炉温从所述第一目标温度降温至第二目标温度；(4)将炉温从所述第二目标温度降温至第三目标温度,得到所述砷化镓多晶。本发明砷化镓多晶的制备全程在真空环境下进行,原料采用单质砷和单质镓,单质砷和单质镓在第一目标温度下生成熔融状态的砷化镓,再通过炉内的分阶段降温,使不同高度的砷化镓的温度出现差异,从而实现砷化镓凝固成预定形态的多晶棒。(The invention provides a preparation method of gallium arsenide polycrystal, and relates to the technical field of polycrystal synthesis. The preparation method of the gallium arsenide polycrystal provided by the invention comprises the following steps: (1) placing the elemental arsenic and the elemental gallium in a vacuum device furnace, and vacuumizing the furnace; (2) heating the furnace temperature of the vacuum device furnace to a first target temperature; (3) cooling the furnace temperature from the first target temperature to a second target temperature; (4) and cooling the furnace temperature from the second target temperature to a third target temperature to obtain the gallium arsenide polycrystal. The preparation of the gallium arsenide polycrystal is carried out in a vacuum environment in the whole process, the raw materials adopt simple substance arsenic and simple substance gallium, the simple substance arsenic and the simple substance gallium generate gallium arsenide in a molten state at a first target temperature, and the temperature of the gallium arsenide with different heights is different through staged temperature reduction in the furnace, so that the gallium arsenide is solidified into a polycrystal rod with a preset shape.)

1. A preparation method of gallium arsenide polycrystal is provided, the gallium arsenide polycrystal is prepared in a vacuum device furnace, and the preparation method is characterized by comprising the following steps:

(1) placing the elemental arsenic and the elemental gallium in a vacuum device furnace, and vacuumizing the furnace;

(2) heating the furnace temperature of the vacuum device furnace to a first target temperature;

(3) cooling the furnace temperature from the first target temperature to a second target temperature;

(4) cooling the furnace temperature from the second target temperature to a third target temperature to obtain the gallium arsenide polycrystal;

the first target temperature is 1245 ℃, the second target temperature is 800-.

2. The method of claim 1, wherein the vacuum furnace comprises at least one temperature-controlled zone from the bottom upward, and the temperature-controlled zones are parallel to each other.

3. The production method according to claim 1, wherein the vacuum apparatus furnace includes six temperature-controlled regions which are provided in the order of a first temperature-controlled region, a second temperature-controlled region, a third temperature-controlled region, a fourth temperature-controlled region, a fifth temperature-controlled region, and a sixth temperature-controlled region from the bottom of the vacuum apparatus furnace upward, and the priority of temperature adjustment is in the order of the first temperature-controlled region, the second temperature-controlled region, the third temperature-controlled region, the fourth temperature-controlled region, the fifth temperature-controlled region, and the sixth temperature-controlled region.

4. The method according to claim 3, wherein the elemental gallium is placed in a crucible having a height between the second temperature-controlled zone and the third temperature-controlled zone in step (1).

5. The production method according to claim 4, wherein the first temperature-controlled zone, the second temperature-controlled zone, the third temperature-controlled zone, the fourth temperature-controlled zone, the fifth temperature-controlled zone, and the sixth temperature-controlled zone are equal in height.

6. The method of claim 3, wherein the crucible has an inner diameter of 6 inches.

7. The preparation method according to claim 3, wherein the step (3) specifically comprises the steps of: and respectively cooling the temperatures of the six temperature control areas from the first target temperature to the second target temperature according to the priority sequence at a first cooling rate of 2-4 ℃/min.

8. The method according to claim 1, wherein each of the temperature-controlled regions in step (2) is heated simultaneously; and (4) synchronously cooling each temperature control area according to a second cooling rate.

9. The method of claim 8, wherein the second cooling rate is 4-5 ℃/min.

10. The method according to claim 1, wherein the molar ratio of elemental arsenic to elemental gallium in step (1) is 1.0-1.2: 1.

Technical Field

The invention relates to the technical field of polycrystal synthesis, in particular to a preparation method of gallium arsenide polycrystal.

Background

The current domestic gallium arsenide process for producing polycrystalline materials is HB (horizontal Brillouin method), which uses quartz tubes for vacuum sealing, and most of the prepared polycrystalline materials are 2-inch and 3-inch polycrystalline materials, and the polycrystalline materials are mainly used for producing 4-inch and 6-inch single crystals. However, when a polycrystalline material of 2 inches or 3 inches is used as a raw material for growing a single crystal, a good crystal yield can be obtained when a single crystal having a diameter of 4 inches is produced, but when a single crystal having a diameter of 6 inches is produced, the crystal yield of the single crystal is seriously affected. The reasons why the above problems occur are: (1) the materials of 2 inches and 3 inches are too much, the surface area is increased, and more oxygen molecules are attached to the surface after the cleaning is finished; (2) the excessive material of 2 inches and 3 inches can damage the inner wall of the crucible in the processes of loading, transporting and charging, and if the oxygen molecules are excessive, the inner wall of the crucible is damaged, the growth of the single crystal can be seriously influenced, thereby leading to the low crystallization rate of the 6-inch single crystal.

Disclosure of Invention

The invention mainly aims to provide a preparation method of gallium arsenide polycrystal, aims to provide a novel gallium arsenide polycrystal raw material for synthesizing 6-inch gallium arsenide single crystal, and solves the problem that polycrystal materials of only 2 inches and 3 inches can be used as raw materials for growing single crystal at present.

In order to achieve the above object, the present invention provides a method for preparing a gallium arsenide polycrystal, wherein the gallium arsenide polycrystal is prepared in a vacuum device furnace, the vacuum device furnace comprises at least one temperature control region from the bottom to the top, and the temperature control regions are parallel to each other, the method comprises the following steps:

(1) placing the elemental arsenic and the elemental gallium in a vacuum device furnace, and vacuumizing the furnace;

(2) heating the furnace temperature of the vacuum device furnace to a first target temperature;

(3) cooling the furnace temperature from the first target temperature to a second target temperature;

(4) and cooling the furnace temperature from the second target temperature to a third target temperature to obtain the gallium arsenide polycrystal.

In the technical scheme of the invention, the whole preparation process of gallium arsenide polycrystal is carried out in a vacuum environment, the raw materials adopt simple substance arsenic (with the purity of 99.9999%) and simple substance gallium (with the purity of 99.9999%), the simple substance arsenic and the simple substance gallium generate gallium arsenide in a molten state at a first target temperature, and the temperature of the gallium arsenide with different heights is different through staged temperature reduction in a furnace, so that the gallium arsenide is solidified into a polycrystal rod with a preset shape.

The first target temperature is 1245 ℃, the second target temperature is 800-.

Because the simple substance arsenic is heated to 613 ℃, the simple substance arsenic can be directly sublimated into arsenic vapor without being in a liquid state; the melting point of the simple substance gallium is 29.76 ℃, and the boiling point is 2403 ℃; the melting point of gallium arsenide is 1238 ℃. In the technical scheme of the invention, the first target temperature is 1245 ℃, in the process of heating the elemental arsenic and the elemental gallium from the room temperature to 1245 ℃, the arsenic is sublimated into steam and is diffused in the whole vacuum device furnace, the arsenic steam is continuously diffused and is contacted with the gallium in a molten state to react to generate gallium arsenide, and the generated gallium arsenide is in a molten state at 1245 ℃.

When the elemental gallium and the elemental arsenic completely react to generate the gallium arsenide, the temperature is reduced to a second target temperature (namely 800-.

As a preferable embodiment of the method for preparing gallium arsenide polycrystal according to the present invention, the vacuum apparatus furnace includes at least one temperature control region from the bottom upward, and the temperature control regions are parallel to each other.

According to the technical scheme, the temperature is adjusted through a plurality of temperature control areas arranged in parallel in the vacuum device furnace, and each temperature control area can independently control the temperature, so that the gradient control of the temperatures corresponding to different heights in the vacuum device furnace can be realized.

As a preferred embodiment of the preparation method of gallium arsenide polycrystal, the vacuum device furnace includes six temperature control regions, the temperature control regions are sequentially set from the bottom of the vacuum device furnace to the top as a first temperature control region, a second temperature control region, a third temperature control region, a fourth temperature control region, a fifth temperature control region and a sixth temperature control region, and the priority of temperature adjustment is sequentially the first temperature control region, the second temperature control region, the third temperature control region, the fourth temperature control region, the fifth temperature control region and the sixth temperature control region.

In the technical scheme of the invention, six temperature control areas in the vacuum device furnace are arranged, and a first temperature control area, a second temperature control area, a third temperature control area, a fourth temperature control area, a fifth temperature control area and a sixth temperature control area are sequentially arranged from the bottom to the top. It should be noted that, the priority order described in the present invention is set for the step (3) of cooling the furnace temperature from the first target temperature to the second target temperature, in the cooling stage, according to the priority order, the first temperature control zone starts cooling first, when the temperature of the first temperature control zone is reduced to the target temperature (i.e. the second target temperature), the second temperature control zone starts cooling again, when the temperature of the second temperature control zone is reduced to the target temperature (i.e. the second target temperature), the third temperature control zone starts cooling again, until the temperature of the sixth temperature control zone is reduced to the target temperature (i.e. the second target temperature) according to the rule.

As a preferable embodiment of the preparation method of gallium arsenide polycrystal according to the present invention, in the step (1), elemental gallium is placed in a crucible, and the height of the crucible is between the second temperature control region and the third temperature control region.

In the technical scheme of the invention, a crucible which is matched with the size of the vacuum device furnace and is used for containing the elemental gallium is placed in the vacuum device furnace. The crucible is arranged at the center of the bottom of the vacuum device, the height of the crucible is between the second temperature control area and the third temperature control area, namely the crucible integrally occupies three temperature control areas along the height direction, namely the first temperature control area, the second temperature control area and the third temperature control area, at the moment, when the furnace temperature is reduced from the first target temperature to the second target temperature in the step (3), the molten gallium arsenide in the crucible is condensed in three gradients in the vertical direction, and therefore gallium arsenide polycrystal with good morphological structure can be synthesized.

As a preferred embodiment of the method for preparing a gallium arsenide polycrystalline according to the present invention, the first temperature control region, the second temperature control region, the third temperature control region, the fourth temperature control region, the fifth temperature control region, and the sixth temperature control region have the same height.

In a preferred embodiment of the method for producing a gallium arsenide polycrystal according to the present invention, the crucible has an inner diameter of 6 inches.

In the technical scheme of the invention, the inner diameter of the crucible is 6 inches, 6 inches of gallium arsenide polycrystal can be synthesized, and the synthesized 6 inches of gallium arsenide polycrystal can be directly used for synthesizing 6 inches of gallium arsenide single crystal.

As a preferred embodiment of the method for preparing gallium arsenide polycrystals, the step (3) specifically includes the following steps: and respectively cooling the temperatures of the six temperature control areas from the first target temperature to the second target temperature according to the priority sequence at a first cooling rate of 2-4 ℃/min.

In the technical scheme of the invention, in the process of reducing the furnace temperature from the first target temperature (1245 ℃) to the second target temperature (800-. Repeated experiments show that gallium arsenide polycrystal with good morphological structure can be synthesized when the first cooling rate is 2-4 ℃/min. And (3) in the cooling process of the step (3), the temperatures of the other temperature control regions are kept unchanged except for the temperature change of the temperature control region being cooled, namely, after the temperature of the first temperature control region is reduced to the target temperature (namely, the second target temperature), the temperature of the second temperature control region is started to be cooled again, and in the cooling process of the second temperature control region, the temperatures of the first temperature control region, the third temperature control region, the fourth temperature control region, the fifth temperature control region and the sixth temperature control region are kept unchanged.

As a preferred embodiment of the preparation method of the gallium arsenide polycrystal, in the step (2), each temperature control area is synchronously heated; and (4) synchronously cooling each temperature control area according to a second cooling rate.

In the technical scheme of the invention, the temperature of each temperature control area is kept the same in the temperature rising process in the step (2) and the temperature reducing process in the step (4).

As a preferred embodiment of the preparation method of the gallium arsenide polycrystal, the second cooling rate is 4-5 ℃/min.

The inventor finds out through a large number of experiments that the second cooling rate is kept to be 4-5 ℃/min in the cooling process of the step (4), and the gallium arsenide polycrystalline rod can be prevented from generating cracks.

As a preferred embodiment of the preparation method of the gallium arsenide polycrystal, the molar ratio of the elemental arsenic and the elemental gallium in the step (1) is 1.0-1.2: 1.

In the technical scheme of the invention, the addition amount of the simple substance arsenic in the synthetic raw material is controlled to be slightly higher than that of the simple substance gallium, so that the simple substance gallium is completely converted into the gallium arsenide, and the situation that the synthetic gallium arsenide polycrystalline rod contains simple substance gallium impurities can be avoided.

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

the preparation of the gallium arsenide polycrystal is carried out in a vacuum environment in the whole process, the raw materials adopt simple substance arsenic and simple substance gallium, the simple substance arsenic and the simple substance gallium generate gallium arsenide in a molten state at a first target temperature, and the temperature of the gallium arsenide with different heights is different through staged temperature reduction in the furnace, so that the gallium arsenide is solidified into a polycrystal rod with a preset shape.

Drawings

FIG. 1 is a schematic view showing the structure of a vacuum apparatus furnace according to example 1 of the present invention;

wherein the reference numerals are: 1-vacuumizing switch device, 2-vacuum furnace switch device, 3-furnace body, 4-crucible and 5-temperature control zone; 51-a first temperature control zone, 52-a second temperature control zone, 53-a third temperature control zone, 54-a fourth temperature control zone, 55-a fifth temperature control zone, and 56-a sixth temperature control zone;

FIG. 2 is a photograph of a GaAs polycrystalline rod prepared in example 1 of the present invention;

FIG. 3 is a photograph of a GaAs polycrystalline rod prepared in example 1 of the present invention;

FIG. 4 is a photograph of a gallium arsenide polycrystalline rod prepared in comparative example 1 of the present invention.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to the following specific examples.

Example 1

The schematic structural diagram of the vacuum device furnace of the present embodiment is shown in fig. 1, the vacuum device furnace includes a furnace body 3, a vacuum furnace switch device 2 is disposed on the upper portion of the furnace body 3, a vacuum pumping switch device 1 is disposed on the upper portion of the furnace body 3, and the furnace body 3 is sequentially disposed from the bottom upward, and has a first temperature control region 51, a second temperature control region 52, a third temperature control region 53, a fourth temperature control region 54, a fifth temperature control region 55, and a sixth temperature control region 56, where it should be noted that the first temperature control region 51, the second temperature control region 52, the third temperature control region 53, the fourth temperature control region 54, the fifth temperature control region 55, and the sixth temperature control region 56 are actually controlled by heating wires disposed on the furnace body, and in the present embodiment, the heights of the first temperature control region 51, the second temperature control region 52, the third temperature control region 53, the fourth temperature control region 54, the fifth temperature control region 55, and the sixth temperature control region 56 are all equal. The crucible is used for containing elementary gallium, the crucible is made of boron nitride, the top opening height of the crucible is located in the third temperature control area, and the inner diameter of the crucible is 6 inches and the height of the crucible is 8 inches. In this embodiment, the other raw material, elemental arsenic, may be directly placed in the vacuum apparatus furnace, or may be placed in the vacuum apparatus furnace after being held in another crucible.

The present embodiment is used for preparing a 6-inch gallium arsenide polycrystalline rod, and the preparation method of the 6-inch gallium arsenide polycrystalline rod of the present embodiment includes the following steps:

(1) placing the simple substance arsenic and the simple substance gallium in a vacuum device furnace according to the molar ratio of 1.0-1.2:1 between the arsenic and the gallium, and vacuumizing the furnace;

(2) synchronously heating the temperature of a first temperature control area, a second temperature control area, a third temperature control area, a fourth temperature control area, a fifth temperature control area and a sixth temperature control area in a vacuum device furnace to 1245 ℃ from room temperature;

(3) sequentially cooling the temperatures of a first temperature control zone, a second temperature control zone, a third temperature control zone, a fourth temperature control zone, a fifth temperature control zone and a sixth temperature control zone in a vacuum device furnace from 1245 ℃ to 1000 ℃ according to the priority order, wherein the cooling rate is 2.04 ℃/min;

(4) synchronously cooling the temperature of a first temperature control zone, a second temperature control zone, a third temperature control zone, a fourth temperature control zone, a fifth temperature control zone and a sixth temperature control zone in a vacuum device furnace from 1000 ℃ to 200 ℃, wherein the cooling rate is 4.44 ℃/min;

(5) and cooling to 200 ℃ after the temperature of each temperature control area is reduced, and then cooling to normal temperature to obtain the gallium arsenide polycrystalline rod. The temperature variation of each temperature control region in the above preparation process of this example is shown in table 1 below.

TABLE 1 temperature Change in temperature control zones in example 1

The surface of the 6-inch gallium arsenide polycrystalline rod prepared by the embodiment has no crack, and elemental gallium does not exist in the polycrystalline rod, as shown in fig. 2 and fig. 3.

Example 2

The vacuum apparatus furnace of this example has the same structure as that of example 1.

The preparation method of this example is substantially the same as that of example 1, except that the temperature change conditions of the temperature control regions are different. The temperature variation of each temperature control region during the preparation process of this example is shown in table 2 below.

TABLE 2 temperature change conditions of temperature control regions in example 2

The surface of the 6-inch gallium arsenide polycrystalline rod prepared by the embodiment has no crack, and no elemental gallium exists in the polycrystalline rod.

Example 3

The vacuum apparatus furnace of this example has the same structure as that of example 1.

The preparation method of this example is substantially the same as that of example 1, except that the temperature change conditions of the temperature control regions are different. The temperature variation of each temperature control region during the preparation process of this example is shown in table 3 below.

TABLE 3 temperature Change in temperature control zones in example 3

The surface of the 6-inch gallium arsenide polycrystalline rod prepared by the embodiment has no crack, and no elemental gallium exists in the polycrystalline rod.

Comparative example 1

The furnace structure of the vacuum apparatus of this comparative example was the same as that of example 1.

The preparation method of the comparative example is basically the same as that of example 1, except that the temperature change conditions of the temperature control regions are different. The temperature change conditions of the temperature control regions in the preparation process of the comparative example are shown in the following table 4.

TABLE 4 temperature Change in temperature control zones in comparative example 1

The surface of the 6-inch gallium arsenide polycrystalline rod prepared by the comparative example has cracks, elemental gallium exists in the polycrystalline rod, and as shown in fig. 4, white gallium is obtained after the polycrystalline rod is cut off.

Comparative example 2

The furnace structure of the vacuum apparatus of this comparative example was the same as that of example 1.

The preparation method of the comparative example is basically the same as that of example 1, except that the temperature change conditions of the temperature control regions are different. The temperature change conditions of the temperature control regions in the preparation process of the comparative example are shown in the following table 5.

TABLE 5 temperature Change in temperature control zones in comparative example 2

The surface of the 6-inch gallium arsenide polycrystalline rod prepared by the comparative example has cracks, and elemental gallium exists in the polycrystalline rod.

Comparative example 3

The furnace structure of the vacuum apparatus of this comparative example was the same as that of example 1.

The preparation method of the comparative example is basically the same as that of example 1, except that the temperature change conditions of the temperature control regions are different. The temperature change conditions of the temperature control regions in the preparation process of the comparative example are shown in the following table 6.

TABLE 6 temperature Change in temperature control zones of comparative example 3

The surface of the 6-inch gallium arsenide polycrystalline rod prepared by the comparative example has cracks, and elemental gallium exists in the polycrystalline rod.

Effect example 1

The gallium arsenide polycrystals prepared in examples 1 to 3 and comparative examples 1 to 3 were subjected to all-element detection, and the detection results are shown in table 7 below.

TABLE 7 gallium arsenide polycrystal industry element detection standards of examples 1 to 3 and comparative examples 1 to 3

As is clear from Table 6, the 6-inch polycrystalline rods prepared in examples 1 to 3 and comparative examples 1 to 3 each had a content of impurity elements lower than the standard, and could satisfy the semi-insulating production standard.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.