[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO2024027072A1 - 一种超重力下通过熔体迁移制备化合物晶体的方法 - Google Patents

一种超重力下通过熔体迁移制备化合物晶体的方法 Download PDF

Info

Publication number
WO2024027072A1
WO2024027072A1 PCT/CN2022/138864 CN2022138864W WO2024027072A1 WO 2024027072 A1 WO2024027072 A1 WO 2024027072A1 CN 2022138864 W CN2022138864 W CN 2022138864W WO 2024027072 A1 WO2024027072 A1 WO 2024027072A1
Authority
WO
WIPO (PCT)
Prior art keywords
crucible
melt
growth
centrifugal
seed crystal
Prior art date
Application number
PCT/CN2022/138864
Other languages
English (en)
French (fr)
Inventor
王书杰
孙聂枫
怀俊彦
徐森锋
史艳磊
邵会民
刘峥
党冀萍
李晓岚
王阳
刘惠生
Original Assignee
中国电子科技集团公司第十三研究所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 中国电子科技集团公司第十三研究所 filed Critical 中国电子科技集团公司第十三研究所
Publication of WO2024027072A1 publication Critical patent/WO2024027072A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B9/00—Single-crystal growth from melt solutions using molten solvents
    • C30B9/04—Single-crystal growth from melt solutions using molten solvents by cooling of the solution
    • C30B9/06—Single-crystal growth from melt solutions using molten solvents by cooling of the solution using as solvent a component of the crystal composition
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/40—AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B30/00—Production of single crystals or homogeneous polycrystalline material with defined structure characterised by the action of electric or magnetic fields, wave energy or other specific physical conditions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to the field of semiconductor preparation, in particular to a method for preparing compound single crystals by causing melt migration under hypergravity, especially driven by centrifugal force.
  • Compound semiconductors are semiconductor materials composed of two or more elements. They have characteristics such as high saturation speed, easy tailoring of energy bands, and wide band gaps. They have unique advantages in high power and high frequency. They are widely used in wireless communications, power electronics, and optical fibers. It has an irreplaceable position in communications and other industries.
  • the traditional vertical Bridgman method, vertical temperature gradient solidification method, guided mode method, Czochralski method and other melt methods are generally used to grow aluminum oxide, gallium arsenide, indium phosphide, gallium oxide and other large materials.
  • Bulk crystals use physical vapor transport methods, metal-organic chemical vapor deposition, etc. to grow compound semiconductors such as silicon carbide and gallium nitride.
  • the above methods are high-cost and low-efficiency.
  • the melt method is the lowest cost and most efficient crystal preparation method.
  • the melt method due to the high melting point and high saturated vapor pressure of some compound semiconductors, the melt method is either expensive or difficult to prepare by the melt method.
  • Non-proportioned melts can not only reduce the high saturated vapor pressure, but also lower the crystallization point of the melt.
  • it is very difficult to control the growth interface of non-proportioned melts, and as the growth progresses, the ratio becomes worse and worse. , so it is difficult to prepare crystals.
  • the technical solution adopted by the present invention is: a method for preparing compound crystals through melt migration under hypergravity, which includes the following steps:
  • T 0 is the melting point of the compound semiconductor AxBy
  • T 0 is greater than the melting point of the A element
  • Element A melts to form a melt, the space occupied by the melt forms a molten pool, the contact surface between the melt and the seed crystal forms interface I, and the contact surface between the melt and the polycrystalline forms interface II;
  • the melt dissolves the seed crystal, and at interface II, the melt dissolves the polycrystalline, eventually forming a non-proportional melt containing elements A and B until the equilibrium composition at this temperature is reached.
  • the composition in the melt is C 0 ;
  • the A and B elements in the melt move to both sides of the melt pool: the elements that increase the liquid-solid transition equilibrium temperature move toward interface I, and the elements that decrease the liquid-solid transition equilibrium temperature move toward interface II. and the ingredients on both sides change;
  • liquid-solid transition equilibrium temperatures at the two interfaces are different: at the interface II, a degree of superheat ⁇ T h is generated, causing the polycrystals to continue to be dissolved; at the interface I, a degree of undercooling ⁇ T c is generated, causing the seeds to continue to dissolve.
  • the crystal begins to grow into a single crystal;
  • melt migrates toward the polycrystalline direction to achieve single crystal preparation.
  • Centrifugal force is a means of producing supergravity.
  • the invention places an element constituting a compound semiconductor between the seed crystal and the polycrystal, heats the system, and applies centrifugal force to the system.
  • the element melts and dissolves part of the seed crystal and the polycrystal to form a non-proportional melt.
  • the centrifugal force is used to make the elements that lower the liquid-solid transition equilibrium temperature be enriched on the polycrystalline material side, causing the polycrystalline material to dissolve; the elements that increase the liquid-solid transition equilibrium temperature move to the single crystal side, increasing the crystallization point of the melt, resulting in supercooling This causes the seed crystal to begin to grow and expel another element into the melt, keeping the composition of the melt in the molten pool constant.
  • This process is accompanied by molten pool migration, continuously achieving single crystal growth and melting of polycrystalline materials, and ultimately achieving single crystal preparation.
  • This method is suitable for the preparation of compound semiconductors such as gallium oxide, silicon carbide, indium phosphide, and gallium arsenide.
  • Figure 1 is an assembly diagram of the device used in the present invention.
  • Figure 2 is a schematic diagram of the seed crucible.
  • Figure 3 is a schematic diagram of the growth crucible
  • Figure 4 shows the crucible assembly diagram
  • FIG. 5 is a schematic diagram of the present invention
  • Figure 6 is a schematic diagram of melt pool migration during crystal growth.
  • Figure 7 is a schematic diagram after the single crystal growth is completed.
  • a method of preparing compound crystals through melt migration under hypergravity using compound semiconductor polycrystals with the molecular formula AxBy, elemental elements of A, and seed crystals to prepare single crystals.
  • Compound semiconductor AxBy A is one element, B is another element, x and y represent the stoichiometric ratio of the semiconductor, such as indium phosphide (InP), gallium oxide (Ga 2 O 3 ), silicon carbide (SiC), etc. .
  • the purpose of using elemental elements is to form a low-melting-point melt, dissolve polycrystalline and single-crystal compounds, and redistribute the A and B elements in the non-proportional melt through centrifugal force, lowering the melting temperature of the polycrystalline interface and increasing the single-crystalline compound.
  • the growth temperature of the crystal interface enables the preparation of single crystals.
  • A is a metal element such as gallium, indium, etc., or a semiconductor element such as silicon, germanium, etc.
  • B is a non-metal element, such as oxygen, carbon, phosphorus, arsenic, etc.
  • the above purpose can be achieved by using elemental elements A or B, but B may be a gaseous element such as oxygen; or it may be a carbon element with an extremely high melting point, both of which are not suitable.
  • the single substance of element A is used to prepare single crystals.
  • element A is a metal element or non-metal element whose melting point is below 2000°C and is not easily volatile, such as In, Ga, Al, Si, Ge, etc.
  • the method includes the following steps: placing a compound semiconductor polycrystal with a molecular formula of AxBy, a simple substance of element A, and a seed crystal in a crucible in close contact in sequence, placing the crucible horizontally on a centrifugal rotating device, and heating the crucible to T 0 , 800°C ⁇ T 0 ⁇ T m , T m is the melting point of the compound semiconductor AxBy, and T 0 is greater than the melting point of the A element.
  • Element A melts to form a melt, the space occupied by the melt forms a molten pool, the contact surface between the melt and the seed crystal forms interface I, and the contact surface between the melt and the polycrystalline forms interface II; initially there is only element A in the melt.
  • the melt dissolves the seed crystal.
  • the melt dissolves the polycrystalline.
  • the melt contains elements A and B, and finally forms a non-proportional melt containing elements A and B until it reaches this temperature.
  • the equilibrium composition of , the composition in the melt is C 0 .
  • Liquid-solid transition equilibrium temperature the melting point and crystallization point of the compound.
  • the content of elements A and B affects the melting point and crystallization point of the melt (“liquid-solid transition equilibrium temperature”).
  • the melt temperature is different, and the content of each element in it when reaching equilibrium is also different. If the temperature is Tm, the content of each element in the melt is the ratio in the molecular formula; if the temperature is set to T 0 , the component in the melt is C. Different components have different liquid-solid transition equilibrium temperatures.
  • the composition of the melt at this temperature is determined, and the liquid-solid transition equilibrium temperature of the melt is determined to be T 0 .
  • dissolution can also be expressed as “erosion”, which can be compared to water dissolving solid sugar or salt.
  • liquid-solid transition equilibrium temperatures at the two interfaces are different:
  • the actual temperature is T0. Due to the movement of elements, the liquid-solid transition equilibrium temperature decreases, resulting in a superheat degree ⁇ T h , causing polycrystals to continue to be dissolved;
  • the actual temperature is T0. Due to the movement of elements, the liquid-solid transition equilibrium temperature increases, resulting in a degree of supercooling ⁇ T c , which causes the seed crystal to continue to grow into single crystals.
  • melt migrates toward the polycrystalline direction to achieve single crystal preparation.
  • the melt in the molten pool contains two elements A and B.
  • One of the key points of the present invention is to increase the liquid-solid transition equilibrium temperature at the interface between the seed crystal and the melt, and to reduce the liquid-solid transition equilibrium temperature at the interface between the polycrystalline and the melt. This is It is necessary to set the positions of the seed crystal and the polycrystal relative to the centrifugal spindle according to the characteristics of the elements.
  • the present invention also proposes a method for preparing compound crystals through melt migration under hypergravity using special equipment.
  • the device includes a centrifugal rotating motor 16, a centrifugal spindle 17 connected to the centrifugal rotating motor 16, a connecting rod 20 connected to the centrifugal spindle 17 and arranged horizontally, and a crystal growth device connected to the connecting rod 20.
  • the crystal growth equipment includes a furnace side disk 5 connected to the connecting rod 20, a furnace barrel 6 connected to the furnace side disk 5 and forming a sealed space.
  • An insulation layer 7 is provided close to the furnace barrel 6 in the sealed space, and is placed within the insulation layer 7.
  • the combined crucible and the heating wire 4 around the combined crucible have an outer top block 12 and an inner pad block 13 at both ends of the combined crucible; the crystal growth equipment is placed in a horizontal direction.
  • the combined crucible includes a growth crucible 14 and a seed crucible 15 that are placed horizontally and combined with each other.
  • growth crucible 14 includes a crucible base 14-2 and crucible walls 14-3 that form a growth zone 14-1.
  • the seed crystal crucible 15 includes a jacket layer 15-1, a seed crystal cover 15-5 connecting the jacket layer 15-1, a platform 15-3 inside the jacket layer 15-1, and the platform 15-3 to the seed crystal
  • the space in the cover 15-5 is the seed hole 15-2, and the space above the platform 15-3 is the connection area 15-4.
  • the angle ⁇ between the seed crystal cover 15-5 and the jacket layer 15-1 is between 70° and 85°, and the seed crystal cooperates with this angle to prevent the seed crystal from moving.
  • the inner diameter of the jacket layer 15-1 is larger than the outer diameter of the crucible wall 14-3, and the difference between the two diameters is less than 2 mm, and the two can be closely combined.
  • the device also includes a thermocouple I8, a thermocouple II9, and a thermocouple III10 arranged on the side of the combined crucible.
  • the thermocouple I8 passes through the furnace side plate 5 and the slider I18 connected to the centrifugal spindle 17, and derives signals through the thermocouple connection line 11.
  • Thermocouple II9 and thermocouple III10 pass through the furnace side plate 5 and the slider II19 connected to the centrifugal spindle 17, and derive their signals through the thermocouple connecting wire 11.
  • indium phosphide Take indium phosphide (InP) as an example.
  • the density of indium is greater than that of phosphorus; in a phosphorus-indium melt, increasing indium will reduce the liquid-solid transition equilibrium temperature of the melt, while increasing phosphorus will increase the liquid-solid transition equilibrium temperature of the melt.
  • the purpose is to make the polycrystal 2 and the growth crucible 14 in close contact to prevent the centrifugal force from squeezing the melt 3 in the molten pool 22 into the gap in subsequent steps.
  • the element 3 of element A in this embodiment is the indium element, is placed on the surface of the polycrystal 2 .
  • the element 3 of element A is disk-shaped, and its outer diameter is the same as the inner diameter of the growth crucible 14 .
  • the seed crystal cover 15-5 is used to block the seed crystal hole 15-2.
  • the growth crucible 14 and the seed crystal crucible 15 form a combined crucible, as shown in Figure 4.
  • thermocouple I8, thermocouple II9 and thermocouple III10 are arranged through the insulation layer 7, and the temperature measuring heads of the thermocouple I8, thermocouple II9 and thermocouple III10 pass through the inner wall of the insulation layer 7 and are close to the outer wall of the combined crucible.
  • thermocouple I8 is connected to the slider I18 through the furnace side disk 5 to derive the temperature signal
  • thermocouple II9 and thermocouple III10 are connected to the slider II19 through the furnace side disk 5 to derive the temperature signal.
  • the above steps complete the assembly of the crystal growth equipment.
  • two crystal growth devices are assembled.
  • the two crystal growth devices are symmetrically arranged on both sides of the centrifugal spindle 17 . If there are more than two, they should be evenly arranged around the centrifugal spindle 17 .
  • the combination crucible is placed in a position where the seed crystal 1 is close to the centrifugal spindle 17 .
  • the furnace space formed by the furnace barrel 6 and the furnace side plate 5 is evacuated to 100 Pa through the gas filling and exhausting pipeline 23, and then filled with inert gas to a pressure of 3MPa-4MPa.
  • the combined crucible is heated by the heating wire 4, the temperature is detected by the thermocouples I8, II9, and III10, and is heated to the temperature T 0 .
  • T 0 is limited to 800°C ⁇ T 0 ⁇ T m .
  • the element 3 of element A (indium in this embodiment) melts into a melt, and the occupied space forms a molten pool 22.
  • the melt dissolves part of the seed crystal 1 and the polycrystalline 2, forming a non-complex containing indium-phosphorus in the molten pool.
  • the composition of the binary melt is C 0 , and the interface I3-1 between the seed crystal 1 and the melt and the interface II3-2 between the polycrystal 2 and the melt are formed.
  • Step 2 Start the centrifugal rotating motor 16 to drive the furnace barrel 6 to rotate, and gradually increase the rotation speed at a speed of 5-50rad/ s2 until the centrifugal force G is greater than 100g.
  • the centrifugal force G is usually expressed as a multiple of g (gravitational acceleration).
  • the radius R can be regarded as the distance from the furnace side disk 5 to the centrifugal spindle 17 .
  • the rotation speed of the centrifugal rotating motor 16 can be calculated.
  • centrifugal force G greater than 50g can cause the separation of elements in the melt.
  • G is set to be greater than 100g in this embodiment.
  • the indium element of the melt in the molten pool 22 moves to the polycrystal 2 side, and the composition of the melt reaches Ch at the interface II3-2, generating a superheat ⁇ T h , causing the polycrystal 2 to dissolve; the molten pool
  • the phosphorus element in the melt in 22 moves to the single crystal 1 side, and the composition of the melt reaches C c at the interface I3-1, generating a supercooling degree ⁇ T c , causing the seed crystal 1 to begin to grow a single crystal and expel the indium element to the melt. body, as shown in Figure 5.
  • the horizontal axis of the upper coordinate system is the component C
  • the vertical axis is the temperature T.
  • the curve in the figure is the liquid-solid transition equilibrium temperature of different components in the melt;
  • the horizontal axis of the lower coordinate system is the position L, starting from The starting position is the bottom of the crystal seed 1
  • the vertical axis is the component C
  • the curve in the figure is the component of the melt at different positions in the molten pool 22.
  • the setting direction of the horizontal axis of this figure is opposite to the conventional setting. If the crystal seed 1 is placed in a different position, the starting position and direction of the horizontal axis will change.
  • the proportion of the A element (indium in this embodiment) in the melt is Ch >C 0 >C c
  • the proportion of the B element (phosphorus in this embodiment) in the melt is Ch ⁇ C 0 ⁇ C c
  • the result is that the melt at different positions of the molten pool 22 contains different components and has different liquid-solid transition equilibrium temperatures.
  • the liquid-solid transition equilibrium temperature of a melt with a composition of C 0 is T 0
  • the liquid-solid transition equilibrium temperature of a melt with a composition of Ch is less than T 0
  • the molten pool 22 migrates in the direction of the polycrystalline 2, ultimately achieving single crystal preparation.
  • the seed crystal 1 grows in a direction away from the centrifugal spindle 17, as shown in Figure 6.
  • Step 3 Repeat steps 1-2 to complete the single crystal preparation according to the sample single crystal growth time, as shown in Figure 7. After the growth is completed, the device is dismantled and the single crystal is taken out.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Liquid Deposition Of Substances Of Which Semiconductor Devices Are Composed (AREA)

Abstract

一种超重力下通过熔体迁移制备化合物晶体的方法，所述方法包括：将分子式为AxBy的化合物半导体多晶、A元素的单质、籽晶依次紧密接触放置于坩埚中，并将坩埚水平放置在离心旋转设备上，加热坩埚至T 0，800℃＜T 0＜T m，启动离心旋转设备，使离心力G大于100g；施加离心力后，熔体中的A、B元索向熔池两侧移动，多晶被溶解，籽晶开始生长出单晶；随着多晶不断被溶解和单晶不断生长，熔体向多晶方向迁移，实现单晶制备。

Description

一种超重力下通过熔体迁移制备化合物晶体的方法 技术领域
本发明涉及半导体制备领域，特别是在超重力、尤其是在离心力驱动下引起熔体迁移进行化合物单晶制备的方法。
背景技术
化合物半导体是由两种及以上元素构成的半导体材料，具有饱和速度高、能带易剪裁、带隙宽等特性，在高功率、高频率等方面特有的优势，在无线通信、电力电子、光纤通信等产业中有着不可替代的地位。
当前技术中，一般使用传统的垂直布里奇曼法、垂直温度梯度凝固法、导模法、直拉法等熔体法用来生长氧化铝、砷化镓、磷化铟、氧化镓等大块晶体，利用物理气相输运法、金属有机化学气相沉积等生长碳化硅、氮化镓等化合物半导体，但上述方法成本高、效率低。
熔体法是成本最低且最高效的晶体制备方法，但是因为部分化合物半导体的熔点高、饱和蒸气压高等特点，要么熔体法成本高，要么就是很难通过熔体法制备。而非配比熔体不仅可以降低饱和蒸气压高，也可以降低熔体的结晶点，但是因为非配比熔体生长界面控制难度很大，且随着生长进行，配比度越来越差，因此制备晶体的难度较大。
发明内容
为克服现有技术的缺陷，提出了本发明。
本发明采用的技术方案是：一种超重力下通过熔体迁移制备化合物晶体的方法，包括以下步骤：
将分子式为AxBy的化合物半导体多晶、A元素的单质、籽晶依次紧密接触放置于坩埚中，并将坩埚水平放置在离心旋转设备上；
加热坩埚至T 0，800℃<T 0<T m，T m为化合物半导体AxBy的熔点，T 0大于A元素的熔点；
A元素熔化形成熔体，熔体所占的空间形成熔池，熔体与籽晶的接触面形成界面I，熔体与多晶的接触面形成界面II；
在界面I，熔体溶解籽晶，在界面II，熔体溶解多晶，最终形成含A元素和B元素的非配比熔体，直至达到该温度下的平衡成分，熔体内的成分为C 0；
启动离心旋转设备，使离心力G大于100g；
施加离心力后，熔体中的A、B元素向熔池两侧移动：使得液固转变平衡温度提高的元素向 界面I移动，使得液固转变平衡温度降低的元素向界面II移动，熔体中间和两侧的成分发生变化；
由于成分的不同，在两个界面处的液固转变平衡温度不同：在界面II，产生一个过热度ΔT h，导致多晶继续被溶解；在界面I，产生一个过冷度ΔT c，使得籽晶开始生长出单晶；
随着多晶不断被溶解和单晶不断生长，熔体向多晶方向迁移，实现单晶制备。
现有研究表明，超重力作为一种强化分离手段，可以实现合金中元素的分离，使用该手段可以实现物质的提纯和对两种合金的凝固组织细化。
杨玉厚在《超重力对金属凝固组织细化及元素偏析行为的基础研究》中披露，在超重力场G＝70g下，Fe-C合金中已经有C分离，Fe-0.99wt％C低碳钢奥氏体晶粒显著细化。
离心力是产生超重力的一种手段。
本发明在籽晶和多晶之间放置组成化合物半导体的一种元素，并对系统加热，给系统施加离心力，该元素熔化并溶解部分籽晶和多晶，形成非配比熔体。利用离心力使得降低液固转变平衡温度的元素富集在多晶料侧，并导致多晶料溶解；提高液固转变平衡温度的元素向单晶侧移动，熔体的结晶点提高，产生过冷使得籽晶开始生长并排出另一种元素至熔体中，保持熔池中熔体的成分恒定。这个过程伴随着熔池迁移，不断实现单晶生长和多晶料的熔化，最终实现单晶制备。该方法适用于氧化镓、碳化硅、磷化铟、砷化镓等化合物半导体的制备。
有益效果：采用本发明提出的方法，可以在低于化合物半导体熔点快速生长单晶，提高生长界面临界剪切应力，降低位错密度。同时，降低熔点的同时也能降低熔体的饱和蒸气压，降低压力设备的要求和生长条件，并使得原本不能够利用熔体法制备的晶体实现熔体法的高效生长。
附图说明
图1为本发明使用的装置装配图，
图2为籽晶坩埚的示意图，
[根据细则91更正 22.02.2023]图3为生长坩埚的示意图，
图4为坩埚组装图，
图5为本发明的原理图，
图6为晶体生长过程中熔池迁移示意图，
图7为单晶生长完成后的示意图。
1：籽晶；2：多晶；3：元素A的单质；3-1：界面I；3-2：界面II；4：加热丝；5： 炉侧盘；6：炉筒；7：保温层；8：热电偶I；9：热电偶II；10：热电偶III；11：热电偶连接线；12：外顶块；13：内垫块；14：生长坩埚；14-1：生长区；14-2；14-3坩埚壁；坩埚底座；15：籽晶坩埚；15-1：套层；15-2：籽晶孔；15-3：平台；15-4：连接区；15-5：籽晶盖；16：离心旋转电机；17：离心主轴；18：滑块I；19：滑块II；20：连接杆；21：多晶碎料；22：熔池；23：充放气管路。
具体实施方式
一种超重力下通过熔体迁移制备化合物晶体的方法，使用分子式为AxBy的化合物半导体多晶、A元素的单质、籽晶制备单晶。
化合物半导体AxBy，A为一种元素，B为另一种元素，x和y代表半导体的化学计量比，如磷化铟(InP)、氧化镓(Ga 2O 3)、碳化硅(SiC)等。使用单质元素的目的是形成一个低熔点的熔体，溶解多晶和单晶化合物，通过离心力，使得非配比熔体中的A和B元素重新分布，降低多晶界面的熔化温度，提高单晶界面的生长温度，实现单晶的制备。
按照化学式的命名规则，AxBy中，A为金属元素如镓、铟等，或者半导体元素如硅、锗等，B是非金属元素，例如氧、碳、磷、砷等。
原理上，使用A或B的单质元素都可以实现上述目的，但B可能是氧等气态元素的；或者是碳元素，熔点极高，均不适合。本发明中使用元素A的单质实现单晶的制备。
本发明中，元素A为熔点在2000℃以下且不易挥发的金属元素或者非金属元素，如In、Ga、Al、Si、Ge等。
所述方法包括以下步骤：将分子式为AxBy的化合物半导体多晶、A元素的单质、籽晶依次紧密接触放置于坩埚中，并将坩埚水平放置在离心旋转设备上加热坩埚至T 0，800℃<T 0<T m，T m为化合物半导体AxBy的熔点，T 0大于A元素的熔点。
A元素熔化形成熔体，熔体所占的空间形成熔池，熔体与籽晶的接触面形成界面I，熔体与多晶的接触面形成界面II；熔体内开始只有A元素。
在界面I，熔体溶解籽晶，在界面II，熔体溶解多晶，熔体内包含A元素和B元素，最终形成含A元素和B元素的非配比熔体，直至达到该温度下的平衡成分，熔体内的成分为C 0。
此时，如果温度保持不变、熔体保持静止状态，界面I和界面II以及熔体中间的液固转变平衡温度相同，可以实现平衡，熔体不再溶解籽晶和多晶。
“液固转变平衡温度”：该化合物的熔点和结晶点。A、B元素的含量影响熔体的熔点和结晶点(“液固转变平衡温度”)。
熔体温度不同，达到平衡时其中各元素的含量也不同。如果温度为Tm，熔体各元素的含量为分子式中的比例；如果是设定温度T 0，熔体内的成分为C。成分不同，液固转变平衡温度也不同。
设定了温度T 0，也就决定了该温度下熔体的成分，同时决定了熔体的液固转变平衡温度为T 0。
上述的“溶解”，也可表述为“侵蚀”，可以类比为水溶解固体的糖或盐。
启动离心旋转设备，以5-50rad/s 2的加速度逐渐增加转速，直至离心力G大于100g。
在离心力的作用下，不同密度A、B元素向熔池两侧移动，通过设置籽晶和多晶相对于离心旋转轴的位置，实现：使得液固转变平衡温度提高的元素向界面I移动，使得液固转变平衡温度降低的元素向界面II移动，熔池中间和两侧的熔体中的成分发生变化。
由于成分的不同，在两个界面处的液固转变平衡温度不同：
在界面II，实际温度为T0，由于元素的移动使得液固转变平衡温度降低，产生一个过热度ΔT h，导致多晶继续被溶解；
在界面I，实际温度为T0，由于元素的移动使得液固转变平衡温度提高，产生一个过冷度ΔT c，使得籽晶持续生长出单晶。
随着多晶不断被溶解和单晶不断生长，熔体向多晶方向迁移，实现单晶制备。
熔池内的熔体包含两种元素A和B，本发明的关键点之一是提高籽晶与熔体界面的液固转变平衡温度，降低多晶与熔体界面的液固转变平衡温度，这就需要根据元素的特性，设置籽晶与多晶相对于离心主轴的位置。
共有4种情况，如下表所示：
Figure PCTCN2022138864-appb-000001
本发明还提出了一种专用设备实现超重力下通过熔体迁移制备化合物晶体的方法。
参看图1，所述装置包括离心旋转电机16、连接离心旋转电机16的离心主轴17、连接离心主轴17且水平设置的连接杆20以及连接在连接杆20上的晶体生长设备。
晶体生长设备包括连接在连接杆20上的炉侧盘5、与炉侧盘5连接并形成密闭空间的炉筒6，在密闭空间内贴近炉筒6设置保温层7，在保温层7内放置组合坩埚及组合坩埚周边的加热丝4，在组合坩埚两端分别有外顶块12和内垫块13；晶体生长设备水平方向放置。
组合坩埚包括水平放置且相互结合的生长坩埚14和籽晶坩埚15。
参看图3，生长坩埚14包括形成生长区14-1的坩埚底座14-2和坩埚壁14-3。
参看图2，所述籽晶坩埚15包括套层15-1、连接套层15-1的籽晶盖15-5、套层15-1内部的平台15-3，平台15-3至籽晶盖15-5的空间为籽晶孔15-2，平台15-3上部的空间为连接区15-4。籽晶盖15-5与套层15-1之间的夹角θ在70°至85°之间，籽晶与该角度相配合，防止籽晶移动。
套层15-1的内径大于坩埚壁14-3的外径，两个直径差小于2mm，两者可以紧密结合。
所述装置还包括设置在组合坩埚侧的热电偶I8、热电偶II9、热电偶III10，热电偶I8经炉侧盘5、连接离心主轴17的滑块I18，通过热电偶连接线11导出信号，热电偶II9、热电偶III10经炉侧盘5、连接离心主轴17的滑块II19，通过热电偶连接线11导出信号。
晶体生长设备在离心主轴17周边均匀设置2-4个。
以磷化铟(InP)为例。铟的密度大于磷的密度；磷-铟熔体中，增加铟会降低熔体的液固转变平衡温度，增加磷会提高提高熔体的液固转变平衡温度。
使用上述装置实现超重力下通过熔体迁移制备化合物晶体的方法具体步骤如下：
步骤1、
1、将磷化铟多晶碎料21置于生长坩埚14中，通过加热使其熔化并降温凝固为磷化铟多晶
2，目的是使多晶2与生长坩埚14紧密接触，防止后续步骤中离心力将熔池22中的熔体3挤压进入缝隙。
将元素A的单质3，本实施例为铟元素，置于多晶2表面上，元素A的单质3为圆盘形，其外径与生长坩埚14的内径相同。
将籽晶坩埚15中的套层15-1的内表面与生长坩埚14生长区14-1外表面装配在一起，坩埚壁14-3的顶端抵住平台15-3，将籽晶1放置于籽晶孔15-2中，利用籽晶盖15-5封堵籽晶孔15-2。生长坩埚14、籽晶坩埚15组成组合坩埚，如图4所示。
2、将组合坩埚置于炉筒6中，通过外顶块12和内垫块13固定组合坩埚。
组合坩埚外部为加热丝4，加热丝4外部为保温层7。穿过保温层7布置热电偶I8、 热电偶II9、热电偶III10，热电偶I8、热电偶II9、热电偶III10的测温头穿过保温层7的内壁接近组合坩埚外壁。
热电偶I8通过炉侧盘5连接滑块I18导出温度信号，热电偶II9和热电偶III10通过炉侧盘5连接滑块II19导出温度信号。
上述步骤完成晶体生长设备的组装。晶体生长设备可以有2-4个，本实施例中，组装两个晶体生长设备。
3、将炉筒6固定到炉侧盘5上，并将炉侧盘5固定到连接杆20上，连接杆20与离心主轴17相连。
两个晶体生长设备在离心主轴17两侧对称设置。多于两个的话，在离心主轴17周边均匀设置。
由于铟的密度大于磷的密度，磷-铟熔体中，增加铟会降低熔体的液固转变平衡温度，因此，本实施例中，组合坩埚的放置位置为籽晶1靠近离心主轴17。
以上过程完成装置的装配，如图1所示。
将炉筒6和炉侧盘5形成的炉体空间通过充放气管路23抽真空至100Pa，然后充入惰性气体，气压至3MPa-4MPa。
通过加热丝4对组合坩埚进行加热，通过热电偶I8、热电偶II9、热电偶III10检测温度，加热至温度T 0。
理论上，只要T 0大于元素A的熔点即可实现晶体的生长；同样离心力下，T0越高，晶体生长的越快，T 0过低，生长过程会很慢，因此，本实施例将T 0限定在800℃<T 0<T m。
元素A的单质3(本实施例中为铟)熔化为熔体，所占空间形成熔池22，熔体溶解部分籽晶1和多晶2，在熔池中形成含铟-磷的非配比二元熔体，二元熔体成分为C 0，并形成籽晶1与熔体的界面I3-1及多晶2与熔体的界面II3-2。
步骤2、启动离心旋转电机16带动炉筒6转动，以5-50rad/s 2的速度逐渐增加转速，直至离心力G大于100g。
离心力G通常以g(重力加速度)的倍数来表达，G与和转速之间的换算公式如下：G＝1.11×10 -5×R×ω 2×g，G为离心力，ω为转速，单位是rmp，R为半径，单位为厘米。
本实施例中，半径R可以看做炉侧盘5至离心主轴17的距离。
通过以上公式，可以计算出离心旋转电机16的转速。
实验表明，离心力G大于50g就可以引起熔体中元素的分离。为了加快元素分离的速度，进而加快合成速度，本实施例中将G设置为大于100g。
在离心力的作用下，熔池22中熔体的铟元素向多晶2侧移动，熔体在界面II3-2处成分达到C h，产生一个过热度ΔT h，导致多晶2溶解；熔池22中熔体的磷元素向单晶1侧移动，熔体在界面I3-1处成分达到C c，产生一个过冷度ΔT c，使得籽晶1开始生长出单晶并排出铟元素至熔体中，如图5所示。
图5中，上面的坐标系横轴为成分C，纵轴为温度T，图中的曲线为熔体中不同成分下的液固转变平衡温度温度；下面的坐标系横轴是位置L，起始位置为晶籽1的底部，纵轴是成分C，图中的曲线是熔体在熔池22中不同的位置的成分。该图的横轴设置方向与常规设置相反，如果晶籽1放置的位置不同，横坐标的起始位置及方向会有所变化。
本实施例中，A元素(本实施例中为铟)在熔体中的占比C h>C 0>C c，B元素(本实施例中为磷)在熔体中的占比C h<C 0<C c，结果是熔池22不同位置的熔体含有不同的成分，具有不同的液固转变平衡温度。成分为C 0的熔体，其液固转变平衡温度为T 0，成分为C h的熔体，其液固转变平衡温度小于T 0，成分为C c的熔体，其液固转变平衡温度大于T 0。
随着多晶2不断被溶解、晶体的不断生长，熔池22向多晶2方向迁移，最终实现单晶制备。
本实施例中。在此过程中籽晶1向远离离心主轴17方向生长，如图6所示。
进行3-5组实验，分别在1小时、2小时、3小时拆出样品，测试界面I3-1的移动速度；根据移动速度和材料数量决定单晶生长时间。
步骤3、重复步骤1-2的操作，根据样品单晶生长时间完成单晶制备，如图7所示。生长完成后，拆除装置，取出单晶。

Claims (9)

  1. 一种超重力下通过熔体迁移制备化合物晶体的方法，其特征在于，
    所述方法包括以下步骤：
    将分子式为AxBy的化合物半导体多晶、A元素的单质、籽晶依次紧密接触放置于坩埚中，并将坩埚水平放置在离心旋转设备上；
    加热坩埚至T 0，800℃<T 0<T m，T m为化合物半导体AxBy的熔点，T 0大于A元素的熔点；A元素熔化形成熔体，熔体所占的空间形成熔池，熔体与籽晶的接触面形成界面I，熔体与多晶的接触面形成界面II；
    在界面I，熔体溶解籽晶，在界面II，熔体溶解多晶，最终形成含A元素和B元素的非配比熔体，直至达到该温度下的平衡成分，熔体内的成分为C 0；
    启动离心旋转设备，使离心力G大于100g；
    施加离心力后，熔体中的A、B元素向熔池两侧移动：使得液固转变平衡温度提高的元素向界面I移动，使得液固转变平衡温度降低的元素向界面II移动，熔体中间和两侧的成分发生变化；
    由于成分的不同，在两个界面处的液固转变平衡温度不同：在界面II，产生一个过热度ΔT h，导致多晶继续被溶解；在界面I，产生一个过冷度ΔT c，使得籽晶开始生长出单晶；
    随着多晶不断被溶解和单晶不断生长，熔体向多晶方向迁移，实现单晶制备。
  2. 根据权利要求1所述的方法，其特征在于，
    如果A元素的密度大于B元素，且A元素的增加会降低熔体的液固转变平衡温度，或如果A元素的密度小于B元素，且A元素的增加会提高熔体的液固转变平衡温度，则籽晶靠近离心旋转设备的旋转轴；否则，多晶靠近离心旋转设备的旋转轴。
  3. 根据权利要求1所述的方法，其特征在于，
    所述方法使用离心力驱动的制备化合物晶体的装置实现，所述装置包括离心旋转电机(16)、连接离心旋转电机(16)的离心主轴(17)、连接离心主轴(17)水平设置的连接杆(20)以及连接在连接杆(20)上的晶体生长设备；
    所述晶体生长设备水平方向放置，包括连接在连接杆(20)上的炉侧盘(5)、与炉侧盘(5)连接并形成密闭空间的炉筒(6)，在密闭空间内贴近炉筒(6)设置保温层(7)，在保温层(7)内放置组合坩埚及组合坩埚周边的加热丝(4)，在组合坩埚两端分别有外顶块(12)和内垫块(13)；
    所述组合坩埚包括水平放置且相互结合的生长坩埚(14)和籽晶坩埚(15)；
    所述生长坩埚(14)包括形成生长区(14-1)的坩埚底座(14-2)和坩埚壁(14-3)；
    所述籽晶坩埚(15)包括套层(15-1)、连接套层(15-1)的籽晶盖(15-5)、套层(15-1)内部的平台(15-3)，平台(15-3)至籽晶盖(15-5)的空间为籽晶孔(15-2)，平台(15-3)上部的空间为连接区(15-4)。
  4. 根据权利要求3所述的方法，其特征在于，
    所述籽晶盖(15-5)与套层(15-1)之间的夹角(θ)在70°至85°之间。
  5. 根据权利要求3所述的方法，其特征在于，
    所述装置还包括设置在组合坩埚侧的热电偶I(8)、热电偶II(9)及热电偶III(10)。
  6. 根据权利要求3-5任一所述的方法，其特征在于，
    所述晶体生长设备有2-4个，在离心主轴(17)周边均匀设置。
  7. 根据权利要求6所述的方法，其特征在于，
    所述方法包括：
    步骤1、将分子式为AxBy的化合物半导体多晶碎料(21)置于生长坩埚(14)中，加热使其熔化并降温凝固为多晶(2)，使得多晶(2)与生长坩埚(14)紧密接触；将元素A的单质(3)置于多晶(2)表面上；
    将籽晶坩埚(15)的套层(15-1)的内表面与生长坩埚(14)生长区(14-1)外表面装配在一起，将籽晶(1)放置于籽晶孔(15-2)中，利用籽晶盖(15-5)盖住籽晶孔(15-2)；生长坩埚(14)、籽晶坩埚(15)组成组合坩埚；
    将组合坩埚置于炉筒(6)中，通过外顶块(12)和内垫块(13)固定；
    将炉筒(6)固定到炉侧盘(5)上，并将炉侧盘(5)固定到连接杆(20)上；
    将炉筒(6)和炉侧盘(5)形成的炉体空间抽真空至100Pa，然后充入惰性气体，气压至3MPa-4MPa；
    通过加热丝(4)对组合坩埚进行加热，加热至温度T 0；
    步骤2、启动离心旋转电机(16)带动炉筒(6)转动，以5-50rad/s 2的加速度逐渐增加转速，直至离心力G大于100g；
    步骤3、生长完成后，拆除装置，取出单晶。
  8. 根据权利要求7所述的方法，其特征在于，
    元素A的单质(3)为圆盘形，其外径与生长坩埚(14)的内径相同。
  9. 根据权利要求7所述的方法，其特征在于，
    步骤1中，如果A元素的密度大于B元素，且A元素的增加会降低熔体的液固转变平衡温度，或如果A元素的密度小于B元素，且A元素的增加会提高熔体的液固转变平衡温度， 将组合坩埚中的籽晶坩埚(15)靠近离心主轴(17)；
    否则，将组合坩埚中的生长坩埚(14)靠近离心主轴(17)。
PCT/CN2022/138864 2022-08-05 2022-12-14 一种超重力下通过熔体迁移制备化合物晶体的方法 WO2024027072A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210938176.6 2022-08-05
CN202210938176.6A CN116180208A (zh) 2022-08-05 2022-08-05 一种超重力下通过熔体迁移制备化合物晶体的方法

Publications (1)

Publication Number Publication Date
WO2024027072A1 true WO2024027072A1 (zh) 2024-02-08

Family

ID=86431292

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/138864 WO2024027072A1 (zh) 2022-08-05 2022-12-14 一种超重力下通过熔体迁移制备化合物晶体的方法

Country Status (2)

Country Link
CN (1) CN116180208A (zh)
WO (1) WO2024027072A1 (zh)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01103984A (ja) * 1987-10-16 1989-04-21 Hitachi Cable Ltd 化合物半導体結晶精製方法
RU2312156C2 (ru) * 2005-08-04 2007-12-10 Олег Владимирович Анисимов Способ производства особо чистых металлов и монокристаллов из них
EP2343140A1 (en) * 2008-04-04 2011-07-13 Alloys S.A. Advanced Method for producing composite metal materials by crystallisation in a centrifuge force field
CN107937984A (zh) * 2017-11-10 2018-04-20 北京鼎泰芯源科技发展有限公司 一种磷化铟的合成方法及其合成装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01103984A (ja) * 1987-10-16 1989-04-21 Hitachi Cable Ltd 化合物半導体結晶精製方法
RU2312156C2 (ru) * 2005-08-04 2007-12-10 Олег Владимирович Анисимов Способ производства особо чистых металлов и монокристаллов из них
EP2343140A1 (en) * 2008-04-04 2011-07-13 Alloys S.A. Advanced Method for producing composite metal materials by crystallisation in a centrifuge force field
CN107937984A (zh) * 2017-11-10 2018-04-20 北京鼎泰芯源科技发展有限公司 一种磷化铟的合成方法及其合成装置

Also Published As

Publication number Publication date
CN116180208A (zh) 2023-05-30

Similar Documents

Publication Publication Date Title
JP5269384B2 (ja) チョクラルスキー法を用いた半導体単結晶製造方法
JP2009505935A (ja) 結晶成長のための装置及び方法
US4652332A (en) Method of synthesizing and growing copper-indium-diselenide (CuInSe2) crystals
Rudolph et al. The horizontal bridgman method
WO2024027072A1 (zh) 一种超重力下通过熔体迁移制备化合物晶体的方法
JPS58500757A (ja) テルル化水銀カドミウム結晶の成長方法
JPS58135626A (ja) 化合物半導体単結晶の製造方法及び製造装置
US2984626A (en) Production of metal halide ingots
CN218404489U (zh) 一种离心力驱动下熔体迁移制备化合物晶体的装置
CN115198347A (zh) 一种离心合成与生长化合物晶体的装置及方法
JP2868204B2 (ja) 四ほう酸リチウム単結晶の製造装置
JP2800713B2 (ja) 化合物半導体単結晶の製造方法
JP2733898B2 (ja) 化合物半導体単結晶の製造方法
US6497762B1 (en) Method of fabricating crystal thin plate under micro-gravity environment
JPH0341432B2 (zh)
CN1766179B (zh) 一种高质量单晶的生长方法
JPS6385082A (ja) 単結晶の成長方法および成長装置
JP2012036015A (ja) 結晶成長方法
JP2600944B2 (ja) 結晶成長方法
JPH0476926B2 (zh)
JPH11343194A (ja) 単結晶の製造装置および単結晶の製造方法
JP2003176198A (ja) 単結晶製造方法および化合物半導体の単結晶インゴット
JP2766897B2 (ja) 単結晶成長装置
JP2003238287A (ja) 固溶体単結晶の製造方法
JPH05139884A (ja) 単結晶の製造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22953860

Country of ref document: EP

Kind code of ref document: A1