Aluminum gallium nitride material and preparation method thereof
By regulating the growth pressure of the aluminum gallium nitrogen epitaxial layer and combining the vapor deposition reaction method of metal organic matter, high-quality aluminum gallium nitrogen materials were prepared, which solved the problem that traditional methods were difficult to obtain high-quality materials and improved device performance.
Patent Information
- Application Number
- CN202311722828.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-14
- Publication Date
- 2025-06-17
AI Technical Summary
It is difficult to obtain high-quality aluminum gallium nitride single-layer materials in the traditional aluminum gallium nitride epitaxial layer preparation method, resulting in carrier loss and degradation of device performance.
By adjusting the growth pressure of the aluminum gallium nitrogen epitaxial layer and combining with the vapor deposition reaction of metal organic matter, a gallium nitride nucleation layer was prepared on the substrate, and the aluminum gallium nitrogen epitaxial layer was grown by annealing and recrystallization treatment, and the growth pressure was set between 140mbar and 160mbar.
Aluminum gallium nitrogen materials with low impurity concentration and vacancy concentration are achieved, reducing defect density and improving material quality, thereby improving the performance of gallium nitride-based devices.
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Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of gallium nitride semiconductor devices, and more particularly to an aluminum gallium nitride material and a preparation method thereof. Background Art
[0002] External laser diodes are widely used in fields such as biomedicine, environmental protection, sterilization, and ultraviolet curing. Ultraviolet detectors are applied in fields such as flame detection and space detection. Gallium nitride (GaN)-based devices mainly include light-emitting devices and detection devices. Therefore, related ultraviolet devices based on gallium nitride (GaN) play an important role in many current fields.
[0003] However, it is difficult to obtain a high-quality aluminum gallium nitride (Al x Ga 1-x N) single-layer material by the conventional preparation method of the aluminum gallium nitride epitaxial layer, which leads to an increase in non-radiative recombination in the applications of lasers and detectors, causing carrier loss and reducing the performance of gallium nitride (GaN)-based devices. Summary of the Invention
[0004] In view of this, to at least partially solve at least one of the above-mentioned technical problems, the present disclosure provides an aluminum gallium nitride material and a preparation method thereof, which can obtain an aluminum gallium nitride material with both impurity concentration and vacancy concentration at a relatively low level by controlling the growth pressure of the aluminum gallium nitride epitaxial layer, reduce the defect density of the aluminum gallium nitride material, and obtain an aluminum gallium nitride material with high quality.
[0005] According to a first aspect of the present disclosure, there is provided a method for preparing an aluminum gallium nitride material, including: preparing a gallium nitride nucleation layer on a substrate by metalorganic chemical vapor deposition reaction; performing recrystallization treatment on the gallium nitride nucleation layer by annealing; growing an aluminum gallium nitride epitaxial layer on the recrystallized gallium nitride nucleation layer by metalorganic chemical vapor deposition reaction, wherein the growth pressure of the aluminum gallium nitride epitaxial layer is 140 mbar to 160 mbar.
[0006] According to an embodiment of the present disclosure, growing an aluminum gallium nitride epitaxial layer on the recrystallized gallium nitride nucleation layer by metalorganic chemical vapor deposition reaction includes: introducing an aluminum source, a gallium source, and a nitrogen source into the reaction chamber, and reacting at 1000 - 1100 °C to grow an aluminum gallium nitride epitaxial layer on the recrystallized gallium nitride nucleation layer, wherein the flow rate of the aluminum source is 7 - 9 sccm, the flow rate of the gallium source is 29 - 31 sccm, and the flow rate of the nitrogen source is 4 - 6 slm.
[0007] According to an embodiment of the present disclosure, the aluminum source is trimethylaluminum; the gallium source is trimethylgallium or triethylgallium; the nitrogen source is ammonia.
[0008] According to an embodiment of the present disclosure, a gallium nitride nucleation layer is prepared on a substrate by metalorganic chemical vapor deposition (MOCVD), including: introducing a gallium source and a nitrogen source into a reaction chamber, reacting at 500 - 600 °C, and growing a gallium nitride nucleation layer on the substrate, wherein the flow rate of the gallium source is 5 - 7 sccm, and the flow rate of the nitrogen source is 4 - 6 slm.
[0009] According to an embodiment of the present disclosure, the gallium source is trimethylgallium or triethylgallium; the nitrogen source is ammonia.
[0010] According to an embodiment of the present disclosure, the gallium nitride nucleation layer is recrystallized by annealing, including: heating the gallium nitride nucleation layer for annealing to form a three-dimensional island-like crystal structure, wherein the annealing temperature is 1000 °C to 1100 °C.
[0011] According to an embodiment of the present disclosure, the growth thickness of the gallium nitride nucleation layer is 20 nm to 30 nm.
[0012] According to an embodiment of the present disclosure, the substrate includes sapphire.
[0013] According to an embodiment of the present disclosure, before preparing the gallium nitride nucleation layer on the substrate by metalorganic chemical vapor deposition (MOCVD), it further includes: cleaning the substrate at a temperature of 1000 °C to 1200 °C in an H2 atmosphere.
[0014] According to a second aspect of the present disclosure, an aluminum gallium nitride material is provided, which is obtained according to the above preparation method, and the aluminum gallium nitride material is formed on an aluminum gallium nitride nucleation layer.
[0015] By metalorganic chemical vapor deposition (MOCVD), an aluminum gallium nitride epitaxial layer is grown on the gallium nitride nucleation layer under the condition that the growth pressure is set to 140 mbar to 160 mbar, thereby obtaining an aluminum gallium nitride material with both impurity concentration and vacancy concentration at a relatively low level, reducing the defect density of the aluminum gallium nitride material, and improving the quality of the aluminum gallium nitride material. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, the above content and other objects, features, and advantages of the present disclosure will become clearer. In the drawings:
[0017] Figure 1 Schematically shows a structural diagram of an aluminum gallium nitride epitaxial structure according to an embodiment of the present disclosure;
[0018] Figure 2 Schematically shows a flowchart of a preparation method of an aluminum gallium nitride material according to an embodiment of the present disclosure;
[0019] Figure 3A test result graph showing the carbon impurity and vacancy defect concentrations in aluminum gallium nitride materials prepared under different growth pressure conditions according to an embodiment of the present disclosure is schematically shown. Detailed implementation manners
[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, for the sake of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it is obvious that one or more embodiments can be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present disclosure.
[0021] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.
[0022] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.
[0023] In the case of using expressions such as "at least one of A, B, and C, etc.", generally, it should be interpreted according to the meaning commonly understood by those of ordinary skill in the art (for example, "a system having at least one of A, B, and C" should include but not be limited to a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).
[0024] Figure 1 A structural diagram of an aluminum gallium nitride epitaxial structure according to an embodiment of the present disclosure is schematically shown.
[0025] According to an embodiment of the present disclosure, a method for preparing an aluminum gallium nitride material is provided, which is applicable to epitaxially preparing an aluminum gallium nitride material, thereby obtaining an epitaxial structure based on the aluminum gallium nitride material. As Figure 1 shown, the present disclosure provides an aluminum gallium nitride (Al x Ga 1-x N) structure, including: a substrate 10; a gallium nitride nucleation layer 20 disposed on the surface of the substrate 10; and an aluminum gallium nitride epitaxial layer 30 disposed on the surface of the gallium nitride nucleation layer 20.
[0026] Figure 2A flowchart of a method for preparing an aluminum gallium nitride material according to an embodiment of the present disclosure is schematically shown.
[0027] As Figure 2 shown, a method for preparing an aluminum gallium nitride material includes:
[0028] In step S210, a gallium nitride nucleation layer 20 is prepared on a substrate 10 by metalorganic chemical vapor deposition (MOCVD).
[0029] In step S220, the gallium nitride nucleation layer 20 is recrystallized by annealing.
[0030] In step S230, an aluminum gallium nitride epitaxial layer 30 is grown on the recrystallized gallium nitride nucleation layer 20 by metalorganic chemical vapor deposition (MOCVD), wherein the growth pressure of the aluminum gallium nitride epitaxial layer 30 is 140 mbar to 160 mbar.
[0031] According to an embodiment of the present disclosure, a substrate 10 is obtained and placed in a metalorganic chemical vapor deposition (MOCVD) chamber to prepare a low-temperature gallium nitride (GaN) nucleation layer 20.
[0032] According to an embodiment of the present disclosure, the gallium nitride nucleation layer 20 is recrystallized by annealing with temperature increase.
[0033] According to an embodiment of the present disclosure, the growth pressure is set to 140 mbar to 160 mbar in a metalorganic chemical vapor deposition (MOCVD) chamber, and then an aluminum gallium nitride (Al x Ga 1-x N) epitaxial layer 30 is grown.
[0034] According to an embodiment of the present disclosure, for example, the growth pressure can be set to 140 mbar, 150 mbar, or 160 mbar. Preferably, it is 150 mbar. According to an embodiment of the present disclosure, by preparing a gallium nitride nucleation layer 20 on a substrate 10 by metalorganic chemical vapor deposition (MOCVD) and growing an aluminum gallium nitride epitaxial layer 30 on the gallium nitride nucleation layer 20 under the condition that the growth pressure is set to 140 mbar to 160 mbar, an aluminum gallium nitride material with both impurity concentration and vacancy concentration at a relatively low level is obtained, the defect density of the aluminum gallium nitride material is reduced, and the quality is improved.
[0035] According to an embodiment of the present disclosure, sapphire can be selected as the substrate 10.
[0036] According to an embodiment of the present disclosure, before preparing the gallium nitride nucleation layer 20 on the substrate 10 by metalorganic chemical vapor deposition (MOCVD), the temperature is set to 1000 °C to 1200 °C in a metalorganic chemical vapor deposition (MOCVD) chamber, and H2 is introduced to clean the surface of the substrate 10.
[0037] According to an embodiment of the present disclosure, for example, the temperature during cleaning can be set to 1000 °C or 1200 °C, preferably 1100 °C.
[0038] According to an embodiment of the present disclosure, after the surface of the substrate 10 is cleaned, the gallium nitride nucleation layer 20 is started to be prepared on the substrate 10 by metalorganic chemical vapor deposition reaction method.
[0039] According to an embodiment of the present disclosure, a gallium source and a nitrogen source are introduced into the reaction chamber, that is, the metalorganic chemical vapor deposition reaction chamber (MOCVD), and the reaction is carried out at 500-600 °C to prepare the gallium nitride nucleation layer 20.
[0040] According to an embodiment of the present disclosure, for example, the temperature during the growth of the gallium nitride nucleation layer can be set to 500 °C, 550 °C or 600 °C, preferably 550 °C.
[0041] According to an embodiment of the present disclosure, the flow rate of the gallium source during the growth of the gallium nitride nucleation layer can be 5-7 sccm (standard cubic centimeters per minute). For example, the flow rate of the gallium source can be 5 sccm, 6 sccm or 7 sccm, preferably 6 sccm.
[0042] According to an embodiment of the present disclosure, the flow rate of the nitrogen source during the growth of the gallium nitride nucleation layer can be 4-6 slm (liters per minute). For example, the flow rate of the nitrogen source can be 4 slm, 5 slm or 6 slm, preferably 6 slm.
[0043] According to an embodiment of the present disclosure, for example, the gallium source can be trimethylgallium or triethylgallium.
[0044] According to an embodiment of the present disclosure, for example, the nitrogen source can be ammonia.
[0045] According to an embodiment of the present disclosure, the gallium nitride nucleation layer 20 is annealed by heating to form a three-dimensional island-like crystal structure.
[0046] According to an embodiment of the present disclosure, the annealing temperature can be set to 1000 °C to 1100 °C. For example, the annealing temperature can be 1000 °C, 1050 °C or 1100 °C, preferably 1050 °C.
[0047] According to an embodiment of the present disclosure, the growth thickness of the gallium nitride nucleation layer 20 can be 20 nm to 30 nm. For example, the growth thickness of the gallium nitride nucleation layer 20 can be 20 nm or 30 nm.
[0048] According to an embodiment of the present disclosure, the growth thickness affects the crystallization quality and electrical properties of the aluminum gallium nitride material. The growth thickness of 20 nm to 30 nm of the gallium nitride nucleation layer can provide a lower impurity concentration, thereby improving the performance of the gallium nitride (GaN)-based device.
[0049] According to an embodiment of the present disclosure, an aluminum gallium nitride epitaxial layer 30 is grown on the recrystallized gallium nitride nucleation layer 20 by metalorganic chemical vapor deposition reaction method.
[0050] According to an embodiment of the present disclosure, an aluminum source, a gallium source, and a nitrogen source are introduced into a reaction chamber, namely a metalorganic chemical vapor deposition reaction chamber (MOCVD), and a reaction is carried out at 1000 - 1100 °C to grow an aluminum gallium nitride epitaxial layer 30 on the recrystallized gallium nitride nucleation layer 20.
[0051] According to an embodiment of the present disclosure, for example, the temperature during the growth of the aluminum gallium nitride epitaxial layer 30 can be set to 1000 °C or 1100 °C, and preferably 1065 °C.
[0052] According to an embodiment of the present disclosure, the flow rate of the aluminum source introduced during the growth of the aluminum gallium nitride epitaxial layer 30 is 7 - 9 sccm. For example, the flow rate of the aluminum source is 7 sccm or 9 sccm, and preferably 8 sccm.
[0053] According to an embodiment of the present disclosure, the flow rate of the nitrogen source introduced during the growth of the aluminum gallium nitride epitaxial layer 30 is 4 - 6 sccm. For example, the flow rate of the nitrogen source is 4 slm or 6 slm, and preferably 5 slm.
[0054] According to an embodiment of the present disclosure, the flow rate of the gallium source introduced during the growth of the aluminum gallium nitride epitaxial layer 30 is 29 - 31 sccm. For example, the flow rate of the gallium source is 29 sccm or 31 sccm, and preferably 30 sccm.
[0055] According to an embodiment of the present disclosure, when the flow rate of the gallium source is 30 sccm, the flow rate of the nitrogen source is 5 slm, and the concentration of the aluminum source is 8 sccm during the growth of the aluminum gallium nitride epitaxial layer 30, a large number of lattice dislocations inside the generated aluminum gallium nitride material can be avoided, and the reliability of the gallium nitride (GaN)-based device can be improved.
[0056] According to an embodiment of the present disclosure, the aluminum source can be trimethylaluminum.
[0057] According to an embodiment of the present disclosure, the gallium source can be trimethylgallium or triethylgallium.
[0058] According to an embodiment of the present disclosure, the nitrogen source can be ammonia.
[0059] According to an embodiment of the present disclosure, an aluminum gallium nitride material obtained according to the above preparation method is provided, which is formed on the aluminum gallium nitride nucleation layer 20.
[0060] Figure 3 Schematically shows a test result diagram of the carbon impurity and vacancy defect concentrations in the aluminum gallium nitride materials prepared under different growth pressure conditions according to an embodiment of the present disclosure.
[0061] AsFigure 3 As shown, the horizontal axis represents the growth pressure, and the vertical axis represents the carbon impurity concentration and the vacancy concentration respectively. In a metalorganic chemical vapor deposition reaction chamber (MOCVD), the growth pressures are set to 100 mbar, 150 mbar, and 200 mbar respectively, and the carbon impurity concentration and the vacancy concentration of the aluminum gallium nitride materials generated under different growth pressures are compared respectively.
[0062] According to the embodiments of the present disclosure, under the condition that the growth pressure is 100 mbar, the carbon impurity concentration of the aluminum gallium nitride material is relatively high; under the condition that the growth pressure is 200 mbar, the vacancy concentration of the aluminum gallium nitride material is relatively high; under the condition that the growth pressure is 150 mbar, both the carbon impurity concentration and the vacancy concentration of the aluminum gallium nitride material are at a relatively low level.
[0063] According to the embodiments of the present disclosure, the high carbon impurity concentration and the high vacancy concentration result in large self-defects of the aluminum gallium nitride material, increasing the non-radiative recombination and thus reducing the performance. Therefore, the aluminum gallium nitride material prepared under the condition that the growth pressure is 150 mbar reduces the defect density and improves the performance of the gallium nitride (GaN)-based device.
[0064] Those skilled in the art can understand that the features recited in the various embodiments and / or claims of the present disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly recited in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features recited in the various embodiments and / or claims of the present disclosure can be combined and combined in various ways. All such combinations and / or combinations fall within the scope of the present disclosure.
[0065] The above describes the embodiments of the present disclosure. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present disclosure. Although the embodiments are described separately above, this does not mean that the measures in the respective embodiments cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present disclosure.
Claims
1. A preparation method of aluminum gallium nitride material, characterized in that, Comprising: Preparing a gallium nitride nucleation layer (20) on a substrate (10) by metalorganic chemical vapor deposition (MOCVD); Recrystallizing the gallium nitride nucleation layer (20) by annealing; Growing an aluminum gallium nitride epitaxial layer (30) on the recrystallized gallium nitride nucleation layer (20) by metalorganic chemical vapor deposition (MOCVD), wherein the growth pressure of the aluminum gallium nitride epitaxial layer (30) is 140 mbar to 160 mbar.
2. The preparation method according to claim 1, characterized in that, Growing an aluminum gallium nitride epitaxial layer (30) on the recrystallized gallium nitride nucleation layer (20) by metalorganic chemical vapor deposition (MOCVD), comprising: Introducing an aluminum source, a gallium source, and a nitrogen source into a reaction chamber, reacting at 1000 - 1100 °C, and growing the aluminum gallium nitride epitaxial layer (30) on the recrystallized gallium nitride nucleation layer (20), wherein the flow rate of the aluminum source is 7 - 9 sccm, the flow rate of the gallium source is 29 - 31 sccm, and the flow rate of the nitrogen source is 4 - 6 slm.
3. The preparation method according to claim 2, characterized in that: The aluminum source is trimethylaluminum; The gallium source is trimethylgallium or triethylgallium; The nitrogen source is ammonia.
4. The preparation method according to claim 1, characterized in that, Preparing a gallium nitride nucleation layer (20) on a substrate (10) by metalorganic chemical vapor deposition (MOCVD), comprising: Introducing a gallium source and a nitrogen source into a reaction chamber, reacting at 500 - 600 °C, and growing the gallium nitride nucleation layer on the substrate (10), wherein the flow rate of the gallium source is 5 - 7 sccm, and the flow rate of the nitrogen source is 4 - 6 slm.
5. The preparation method according to claim 4, characterized in that: The gallium source is trimethylgallium or triethylgallium; The nitrogen source is ammonia.
6. The preparation method according to claim 1 or 4, characterized in that, Recrystallizing the gallium nitride nucleation layer (20) by annealing, comprising: Performing temperature-raising annealing on the gallium nitride nucleation layer (20) to form a three-dimensional island-like crystal structure, wherein the annealing temperature is 1000 °C to 1100 °C.
7. The preparation method according to claim 1, characterized in that, The growth thickness of the gallium nitride nucleation layer (20) is 20 nm to 30 nm.
8. The preparation method according to claim 1, characterized in that, The substrate (10) comprises sapphire.
9. The preparation method according to claim 1, characterized in that, Before preparing the gallium nitride nucleation layer (20) on the substrate (10) by metalorganic chemical vapor deposition (MOCVD), further comprising: Cleaning the substrate (10) at a temperature of 1000 °C to 1200 °C in an H2 atmosphere.
10. An aluminum gallium nitride material, characterized in that, Obtained by the preparation method according to any one of claims 1 to 9, the aluminum gallium nitride material is formed on an aluminum gallium nitride nucleation layer (20).