Gallium nitride film vapor phase growth method and gallium nitride film

Abstract

The invention discloses a vapor phase growth method of a gallium nitride film and the gallium nitride film, and relates to the technical field of vapor phase growth of semiconductor materials. The method comprises the following steps: S1, arranging the top of a substrate below a linear gas supply port, enabling gallium chloride gas, ammonia gas and carrier gas to flow to the substrate through the linear gas supply port to grow gallium nitride, moving the substrate to the gas output direction of the linear gas supply port, and gradually adjusting the width of the linear gas supply port, the growth of gallium nitride is completed until the tail part of the substrate is positioned below the linear gas supply port; and S2, repeating the step S1 to obtain the gallium nitride thin film. According to the vapor phase growth method of the gallium nitride film and the gallium nitride film provided by the invention, point supply is changed into line supply through the width-adjustable linear gas supply port, and the movable substrate is matched, so that single-point nucleation is realized, and large-area single crystal growth of a film material is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of vapor phase growth of semiconductor materials, and in particular to a vapor phase growth method of a gallium nitride thin film and the gallium nitride thin film. Background Art

[0002] The preparation of large-area single-crystal van der Waals two-dimensional materials has always been a bottleneck to be overcome in academia and industry, and vapor deposition methods are often used. For the vapor deposition of thin films, whether physical vapor deposition or chemical vapor deposition, in general vapor deposition devices, the supply of reactants in the reaction chamber is full-space, that is, when thin film deposition occurs, the reactants or gaseous raw materials fill the entire reaction chamber. This causes the deposition and growth of materials to occur on all interfaces of the entire reaction chamber, including the entire surface of the substrate, and the direct result is multi-point nucleation. The biggest difficulty that multi-point nucleation brings to thin film growth is the inconsistent orientation of nucleation. The inconsistency is reflected in two aspects. One is the inconsistent orientation of the crystal plane, and the upper surface crystal plane of the nucleation has multiple orientations; on the other hand, even if the orientation of the upper surface crystal plane of most nucleations is consistent, the direction of the high symmetry axis in the plane is not necessarily consistent. Different nucleations may rotate at a certain angle around the direction perpendicular to the substrate surface. In the end, either a polycrystalline film is grown, or the grain boundary density and defect density are too large due to the inconsistent orientation of the high symmetry axis in the plane. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for vapor phase growth of a gallium nitride thin film and a gallium nitride thin film.

[0004] The specific technical solutions include the following:

[0005] In a first aspect, a method for vapor phase growth of a gallium nitride thin film is provided, comprising the following steps:

[0006] S1. The top of the substrate is set below the linear gas supply port, and gallium chloride gas, ammonia gas and carrier gas flow to the substrate through the linear gas supply port to grow gallium nitride, and the substrate is moved toward the gas output direction of the linear gas supply port and the width of the linear gas supply port is gradually adjusted until the tail of the substrate is located below the linear gas supply port, thereby completing the growth of gallium nitride;

[0007] S2. Repeat step S1 to obtain a gallium nitride thin film.

[0008] Furthermore, in step S1, the moving speed of the substrate is 1-100 mm / h.

[0009] Furthermore, in step S1, the width of the linear air supply port is adjusted from a width of 0.1-1 mm to a width of 5-10 cm.

[0010] Furthermore, in step S1, the width of the linear air supply port is adjusted by a baffle, which is disposed at two opposite ends of the linear air supply port and movably connected to the linear air supply port.

[0011] Furthermore, the substrate is rectangular or circular.

[0012] Furthermore, the moving speed of the substrate is 5-80 mm / h.

[0013] Furthermore, in step S1, the width of the linear air supply port is adjusted from a width of 0.1-0.8 mm to a width of 8-10 cm.

[0014] Furthermore, the substrate is one of GaN, Al2O3, GaAs, SiC and Si.

[0015] Furthermore, the carrier gas includes at least one of nitrogen, hydrogen, helium and argon.

[0016] Preferably, in step S1, the V / III ratio is controlled to be 40-90 when the gallium chloride gas, ammonia gas and carrier gas are flowed to the substrate through the linear gas supply port to grow gallium nitride.

[0017] Preferably, the temperature of the linear air supply port is 950°C.

[0018] Preferably, the temperature of the substrate is 1050°C.

[0019] Preferably, the substrate is GaN.

[0020] Preferably, the flow rate of ammonia (NH 3) is 3000-3500 sccm.

[0021] Preferably, the flow rate of the gallium chloride (GaCl) is 15-30 sccm.

[0022] Preferably, the flow rate of the carrier gas is 6500sccm-12000sccm.

[0023] Preferably, the carrier gas is nitrogen.

[0024] In a second aspect, a gallium nitride thin film is provided, which is produced by the gas phase growth method of the gallium nitride thin film described in the first aspect.

[0025] The beneficial effects of the present invention are: providing a method for the vapor phase growth of a gallium nitride film and a gallium nitride film that changes point supply to line supply through a linear gas supply port with adjustable width, and cooperates with a movable substrate to achieve single-point nucleation, which is beneficial to large-area single crystal growth of thin film materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0027] Figure 1 A side view of a device for implementing a method for vapor phase growth of a gallium nitride thin film;

[0028] Figure 2 for Figure 1 Cross-sectional view along AA direction;

[0029] Description of the symbols in the figure:

[0030] 1-reaction chamber; 2-graphite tray; 3-magnetic levitation generator; 4-air inlet pipe; 5-linear air supply port; 6-air pump. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0033] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0034] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0035] In order to more fully understand the technical content of the present invention, the technical solution of the present invention is further introduced and illustrated in conjunction with specific embodiments below.

[0036] In this embodiment, the temperature of the linear gas supply port is 950°C, and the temperature of the substrate is 1050°C.

[0037] In this embodiment, the device for implementing the method for vapor phase growth of gallium nitride thin film is as follows: Figure 1 and Figure 2 As shown. Among them, Figure 1 A side view of a device for implementing a method for vapor phase growth of a gallium nitride thin film; Figure 2 for Figure 1 Cross-sectional view along the AA direction.

[0038] The device includes a reaction chamber 1 and a graphite tray 2. The graphite tray 2 is arranged in the reaction chamber 1 and is used to support the substrate. The graphite tray 2 is connected to a magnetic levitation generator 3, which is arranged outside the reaction chamber 1. The magnetic levitation generator 3 can drive the graphite tray 2 to reciprocate along the axial direction of the reaction chamber 1. An air inlet pipe 4 is also provided in the device. The air inlet pipe 4 is used to introduce gallium chloride gas, nitrogen gas and carrier gas. The air inlet pipe 4 is arranged above the graphite tray 2. The end of the air inlet pipe 4 is a linear air supply port 5. The opposite ends of the linear air supply port 5 are provided with baffles, which are movably connected to the linear air supply port 5 and are used to adjust the width of the linear air supply port 5. In addition, an air pump 6 is also provided at one end of the reaction chamber 1. The air pump 6 is used to discharge the waste in the reaction chamber 1 after the preparation of the gallium nitride film is completed.

[0039] Example 1

[0040] A method for vapor phase growth of a gallium nitride thin film, characterized by comprising the following steps:

[0041] S1. The top of the substrate is set below the linear gas supply port, and gallium chloride gas with a flow rate of 20 sccm, ammonia gas with a flow rate of 3200 sccm, and carrier gas (nitrogen) with a flow rate of 8000 sccm flow to the substrate through the linear gas supply port to grow gallium nitride, and the V / III ratio is controlled to be 60. The substrate is moved toward the gas output direction of the linear gas supply port and the width of the linear gas supply port is gradually adjusted until the tail of the substrate is located below the linear gas supply port, and the growth of gallium nitride is completed. The average growth rate of gallium nitride is 48 μm / h; wherein the substrate is GaN, the substrate is circular, the movement speed of the substrate is 50 mm / h, the width of the linear gas supply port is adjusted to adjust the width of the linear gas supply port from 0.5 mm to 8 cm, and the width of the linear gas supply port is adjusted by a baffle, which is arranged at opposite ends of the linear gas supply port and is movably connected to the linear gas supply port;

[0042] S2. Repeat step S1 to obtain the gallium nitride thin film of Example 1.

[0043] Example 2

[0044] A method for vapor phase growth of a gallium nitride thin film, characterized by comprising the following steps:

[0045] S1. The top of the substrate is set below the linear gas supply port, and a gallium chloride gas with a flow rate of 25 sccm, an ammonia gas with a flow rate of 3500 sccm, and a carrier gas (nitrogen) with a flow rate of 9500 sccm flow to the substrate through the linear gas supply port to grow gallium nitride, and the V / III ratio is controlled to be 70. The substrate is moved toward the gas output direction of the linear gas supply port and the width of the linear gas supply port is gradually adjusted until the tail of the substrate is located below the linear gas supply port, and the growth of gallium nitride is completed. The average growth rate of gallium nitride is 72 μm / h; wherein the substrate is GaN, the substrate is circular, the movement speed of the substrate is 1 mm / h, the width of the linear gas supply port is adjusted to adjust the width of the linear gas supply port from 0.1 mm to 5 cm, and the width of the linear gas supply port is adjusted by a baffle, which is arranged at opposite ends of the linear gas supply port and is movably connected to the linear gas supply port;

[0046] S2. Repeat step S1 to obtain the gallium nitride thin film of Example 2.

[0047] Example 3

[0048] A method for vapor phase growth of a gallium nitride thin film, characterized by comprising the following steps:

[0049] S1. The top of the substrate is set below the linear gas supply port, and gallium chloride gas with a flow rate of 30 sccm, ammonia gas with a flow rate of 3300 sccm, and carrier gas (nitrogen) with a flow rate of 10000 sccm flow to the substrate through the linear gas supply port to grow gallium nitride, and the V / III ratio is controlled to be 70. The substrate is moved toward the gas output direction of the linear gas supply port and the width of the linear gas supply port is gradually adjusted until the tail of the substrate is located below the linear gas supply port, and the growth of gallium nitride is completed. The average growth rate of gallium nitride is 59 μm / h; wherein the substrate is GaN, the substrate is rectangular, the moving speed of the substrate is 100 mm / h, the width of the linear gas supply port is adjusted to adjust the width of the linear gas supply port from 1 mm to 10 cm, and the width of the linear gas supply port is adjusted by a baffle, which is arranged at opposite ends of the linear gas supply port and is movably connected to the linear gas supply port;

[0050] S2. Repeat step S1 to obtain the gallium nitride thin film of Example 3.

[0051] The performance of the gallium nitride films of Examples 1-3 was tested, and the test results are shown in Table 1 below:

[0052] Table 1 Performance test results of gallium nitride films of Examples 1-3

[0053] performance Example 1 Example 2 Example 3 Dislocation density <![CDATA[5.75*10 6 cm -2 ]]> <![CDATA[6.45*10 7 cm -2 ]]> <![CDATA[8.53*10 7 cm -2 ]]>

[0054] It can be seen from the test results in Table 1 that the dislocation density test results of the gallium nitride films of Examples 1-3 of the present invention are good.

[0055] In summary, the gas phase growth method of gallium nitride thin film and the gallium nitride thin film provided by the present invention change point supply to line supply through a linear gas supply port with adjustable width, and cooperate with a movable substrate to achieve single-point nucleation, which is conducive to large-area single crystal growth of gallium nitride thin film (thin film material).

[0056] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for vapor phase growth of a gallium nitride thin film, characterized in that: The following steps are involved: S1. The top of the substrate is set below the linear gas supply port, and gallium chloride gas, ammonia gas and carrier gas flow to the substrate through the linear gas supply port to grow gallium nitride, and the substrate is moved toward the gas output direction of the linear gas supply port and the width of the linear gas supply port is gradually adjusted until the tail of the substrate is located below the linear gas supply port, thereby completing the growth of gallium nitride; S2. Repeat step S1 to obtain a gallium nitride thin film.

2. The method for vapor phase growth of a gallium nitride thin film according to claim 1, wherein: In step S1, the moving speed of the substrate is 1-100 mm / h.

3. The method for vapor phase growth of a gallium nitride thin film according to claim 2, wherein: In step S1, the width of the linear air supply port is adjusted from a width of 0.1-1 mm to a width of 5-10 cm.

4. The method for vapor phase growth of a gallium nitride thin film according to claim 3, characterized in that: In step S1 , the width of the linear air supply port is adjusted by means of baffles, which are arranged at opposite ends of the linear air supply port and are movably connected to the linear air supply port.

5. The method for vapor phase growth of a gallium nitride thin film according to claim 4, characterized in that: The substrate is rectangular or circular.

6. The method for vapor phase growth of a gallium nitride thin film according to claim 5, characterized in that: The moving speed of the substrate is 5-80 mm / h.

7. The method for vapor phase growth of a gallium nitride thin film according to claim 6, wherein: In step S1, the width of the linear air supply port is adjusted from a width of 0.1-0.8 mm to a width of 8-10 cm.

8. The method for vapor phase growth of a gallium nitride thin film according to claim 7, characterized in that: The substrate is one of GaN, Al2O3, GaAs, SiC and Si.

9. The method for vapor phase growth of a gallium nitride thin film according to claim 8, characterized in that: The carrier gas includes at least one of nitrogen, hydrogen, helium and argon.

10. A gallium nitride thin film, characterized in that: The gallium nitride thin film is prepared by the gas phase growth method of any one of claims 1 to 9.

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