Partitioned film formation buffer layer preparation method, patterned composite substrate and preparation method thereof

Abstract

This invention discloses a method for preparing a partitioned buffer layer, a patterned composite substrate, and the same method. The preparation method includes: providing a patterned substrate; the three-dimensional pattern on the surface of the patterned substrate has inclined sidewalls, and gap planes exist between adjacent three-dimensional patterns; forming an argon ion accumulation layer, utilizing the repulsive effect between argon ions to bombard the patterned substrate, making the inclined sidewalls positively charged; sputtering negatively charged aluminum atoms that electrostatically adsorb onto the inclined sidewalls to form an aluminum atom thin film; the sputtered aluminum atoms react with at least nitrogen gas to form a first thin film on the gap plane, and the aluminum atom thin film reacts with nitrogen and oxygen gas to form a second thin film on the inclined sidewalls; the first and second thin films constitute a buffer layer. This invention achieves partitioned film formation of a buffer layer on a patterned substrate, where the film elements, proportions, and crystal quality differ and are controllable in different regions, effectively matching the stress and crystal quality during epitaxial growth and reducing defect density.

Description

Technical Field

[0001] This invention relates to the field of semiconductor process technology, and more particularly to a method for preparing a partitioned film buffer layer, a patterned composite substrate, and a method for preparing the same. Background Technology

[0002] In nitride semiconductor epitaxy, physical vapor deposition sputtering buffer layers have become a core technology for improving the quality of GaN / AlN thin films on patterned sapphire substrates. Traditional direct epitaxy on patterned sapphire substrates suffers from high lattice mismatch between sapphire and nitride, as well as parasitic nucleation effects on the pattern sidewalls, resulting in a penetration dislocation density as high as 10-1. 9 -10 10 cm -2 This process induces stacking faults and grain boundary defects. Sputtering buffer layers (such as AlN) can initially suppress dislocation density to 10⁻⁶ by providing a near-epicentric template. 8 cm -2 This significantly improves the photoelectric performance of LEDs by a large margin.

[0003] However, recent studies have found that the buffer layer needs to be doped with trace amounts of oxygen to address the problem of abnormal sidewall growth. Without doping, there is an energy difference between the sidewalls and the c-plane, leading to epitaxial nucleation of GaN on the sidewalls of the pattern, resulting in high-density stacking faults and abnormal epitaxial merging. While oxygen-doped AlON can increase the sidewall surface energy, forcing GaN to preferentially nucleate on the c-plane, it introduces a new bottleneck. Due to oxygen interference with lattice order, c-plane AlON exhibits a mixed polycrystalline / amorphous state, and the dislocation density in the nucleation layer remains high. The polycrystalline interface induces edge-screw dislocation reactions, forming a mixed dislocation concentration region, ultimately generating high-density V-pits on the chip surface, exacerbating nonradiative recombination of charge carriers and causing the LED reverse leakage current to surge by 10-100 times. For deep ultraviolet AlN-LEDs, this problem is further exacerbated.

[0004] Therefore, there is an urgent need to develop novel buffer layer technologies to ensure ultra-high crystal quality (single crystal, low oxygen, low dislocation) on the C-plane while maintaining ultra-high sidewall energy barriers (completely suppressing parasitic nucleation), and simultaneously be compatible with the high-temperature characteristics of deep ultraviolet epitaxy. Breakthrough directions need to consider both differentiated surface energy design and adaptation to epitaxial growth kinetics to achieve a performance leap in nitride semiconductor devices. Summary of the Invention

[0005] This invention provides a method for preparing a partitioned film buffer layer, a patterned composite substrate and its preparation method, to solve the problems of lattice mismatch and parasitic nucleation effect, ensure the quality of C-plane ultra-high crystal, and take into account the high temperature characteristics of deep ultraviolet epitaxy.

[0006] In a first aspect, embodiments of the present invention provide a method for preparing a partitioned film-forming buffer layer, comprising:

[0007] A patterned substrate is provided and placed in a magnetron sputtering system; a plurality of three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls, the inclined sidewalls being non-C-planes; and a gap plane is provided between adjacent three-dimensional patterns, the gap plane being C-planes;

[0008] In the magnetron sputtering system, an argon ion accumulation layer is formed. The patterned substrate is bombarded by the repulsive effect between argon ions to break the chemical bonds in the inclined sidewalls. The inclined sidewalls are positively charged, and the gap plane is electrically neutral.

[0009] Argon gas is introduced into the magnetron sputtering system, and the argon gas is controlled to ionize and bombard the aluminum target, so that the sputtered negatively polar aluminum atoms are attracted by the electrostatic force of the inclined sidewall and form an aluminum atom film on the inclined sidewall.

[0010] Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to control the ionization of the argon and bombardment of the aluminum target, so that the sputtered aluminum atoms react with at least the nitrogen to form a first thin film on the gap plane. At the same time, the aluminum atom thin film reacts with nitrogen and oxygen to form a second thin film on the inclined sidewall. The first and second thin films constitute a buffer layer. The first thin film is an aluminum nitride film, and the second thin film is an aluminum oxynitride film; or, both the first and second thin films are aluminum oxynitride films, and the oxygen content in the first film is less than the oxygen content in the second film.

[0011] Secondly, embodiments of the present invention also provide a method for preparing a patterned composite substrate, comprising:

[0012] A patterned substrate is prepared; wherein a plurality of three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls, the inclined sidewalls being non-C-planes; and there are gap planes between adjacent three-dimensional patterns, the gap planes being C-planes;

[0013] The buffer layer is prepared on the surface of the patterned substrate using the partitioned film buffer layer preparation method as described in the first aspect.

[0014] Thirdly, embodiments of the present invention also provide a patterned composite substrate, prepared using the patterned composite substrate preparation method described in the second aspect; the patterned composite substrate includes:

[0015] A patterned substrate, wherein a plurality of three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls, the inclined sidewalls being non-C-planes; and there are gap planes between adjacent three-dimensional patterns, the gap planes being C-planes;

[0016] The buffer layer includes a first film and a second film; the first film covers the gap plane and the second film covers the inclined sidewall; the first film is an aluminum nitride film and the second film is an aluminum oxynitride film; or, both the first film and the second film are aluminum oxynitride films, and the oxygen content in the first film is less than the oxygen content in the second film.

[0017] The technical solution of this invention utilizes magnetron sputtering technology. Argon ions generated by argon ionization bombard a patterned substrate, making the inclined sidewalls electrically positive and the gap plane electrically neutral. Then, aluminum atoms are generated by bombarding an aluminum target with argon ions, and electrostatic adsorption causes the aluminum atoms to adsorb onto the inclined sidewalls, forming an aluminum film. Subsequently, by introducing oxygen, nitrogen, and argon gases and controlling the sputtering parameters, a buffer layer is formed on the gap plane and inclined sidewalls of the patterned substrate. The buffer layer includes a first thin film and a second thin film. By controlling the flow rate of the gas introduced into the magnetron sputtering system and other parameters, the first thin film is formed on the gap plane of the patterned substrate, and the second thin film is formed on the inclined sidewalls of the patterned substrate. By controlling the oxygen content, when the oxygen content is low, the first thin film can be an aluminum nitride film, and the second thin film can be an aluminum oxynitride film; or, when the oxygen content is high, both the first and second thin films can be aluminum oxynitride films. Even when both the first and second thin films are aluminum oxynitride, their oxygen content differs, with the oxygen content in the first film being lower than that in the second film. Thus, it is essentially possible to achieve partitioned film formation on a patterned substrate, resulting in a patterned composite substrate. It also achieves better film formation continuity and higher coverage, can adapt to epitaxial conditions of different equipment and processes, effectively matches stress and crystal quality, and reduces defect density. Attached Figure Description

[0018] Figure 1 This is a flowchart of a method for preparing a partitioned film-forming buffer layer according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 The diagram shows a structural flowchart of a method for preparing a partitioned film-forming buffer layer.

[0020] Figure 3 yes Figure 1 The diagram shows another structural flowchart of the method for preparing a partitioned film buffer layer;

[0021] Figure 4 yes Figure 1 The diagram shows another structural flow chart of the method for preparing a partitioned film buffer layer;

[0022] Figure 5 This is a flowchart of another method for preparing a partitioned film-forming buffer layer provided in an embodiment of the present invention;

[0023] Figure 6 yes Figure 5 The diagram shows the structural flow chart of the method for preparing the partitioned film-forming buffer layer.

[0024] Figure 7 This is a flowchart of another method for preparing a partitioned film-forming buffer layer provided in an embodiment of the present invention;

[0025] Figure 8 yes Figure 7 The diagram shows the structural flow chart of the method for preparing the partitioned film-forming buffer layer.

[0026] Figure 9 This is a flowchart of a method for preparing a patterned composite substrate according to an embodiment of the present invention;

[0027] Figure 10 and Figure 11 yes Figure 9 The diagram shows two structural flowcharts for the fabrication of patterned composite substrates.

[0028] Figure 12 and Figure 13 These are schematic diagrams of the structures of two patterned composite substrates provided in embodiments of the present invention;

[0029] Figure 14 This is a schematic diagram of another patterned composite substrate provided in an embodiment of the present invention;

[0030] Figure 15 This is an electronic pattern of a patterned composite substrate provided in an embodiment of the present invention;

[0031] Figure 16 for Figure 15 The image shown contains elemental spectra at the sidewalls, i.e., locations other than the C-plane.

[0032] Figure 17 for Figure 15 The elemental content spectrum at the C-plane position, which is the gap in the graphic shown. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0034] The terminology used in the embodiments of this invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. It should be noted that directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this invention. Furthermore, in the context, it should be understood that when referring to an element being formed "on" or "below" another element, it can be formed not only directly on or below the other element, but also indirectly on or below it through intermediate elements. The terms "first," "second," etc., are used for descriptive purposes only and do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] The term "comprising" and its variations as used in this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment".

[0036] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish the corresponding contents and are not used to limit the order or interdependence.

[0037] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0038] Figure 1 This is a flowchart of a method for preparing a partitioned film-forming buffer layer according to an embodiment of the present invention. Figure 2 yes Figure 1 The diagram shown is a structural flow chart of a method for preparing a partitioned film-forming buffer layer. (Refer to...) Figure 1 and Figure 2 The specific method for preparing the partitioned film-forming buffer layer may include:

[0039] S110. A patterned substrate is provided and placed in a magnetron sputtering system; a plurality of three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls, which are non-C-planes; there are gap planes between adjacent three-dimensional patterns, which are C-planes.

[0040] Among them, reference Figure 1 and Figure 2 Figure a) shows that the patterned substrate 10 is the substrate structure for fabricating the buffer layer in this embodiment, and this substrate structure needs to meet specific requirements. Specifically, the patterned substrate 10 needs to have a three-dimensional pattern 11 formed on its surface, and the three-dimensional pattern 11 can be a microstructure protrusion (such as...). Figure 2As shown), it can also be a microstructured pit, which can be achieved through an etching process, and is not limited here. The patterned substrate 10 can specifically be a sapphire patterned substrate, and is not limited here. It should be noted that a three-dimensional pattern 11 is formed on the patterned substrate 10, the purpose of which is to form a C-plane and a non-C-plane on the patterned substrate 10. The area between the patterns is a gap plane 12, which is essentially a C-plane. Regardless of whether the pattern is in the form of a protrusion or a pit, it has an inclined sidewall, and its inclined sidewall 13 is essentially a non-C-plane. Based on the patterned substrate 10 with C-planes and non-C-planes, the purpose of this embodiment of the invention is to form different buffer layer films in the areas of the two surfaces respectively, that is, to realize a buffer layer structure with partitioned film formation.

[0041] S120. In the magnetron sputtering system, an argon ion accumulation layer is formed. The repulsion between argon ions is used to bombard the patterned substrate, causing the chemical bonds in the tilted sidewalls to break. The tilted sidewalls are positively charged, and the gap plane is electrically neutral.

[0042] Magnetron sputtering is a commonly used physical vapor deposition (PVD) technique for depositing high-quality, uniform thin films onto material surfaces. Its principle involves using a magnetic field within a vacuum chamber to confine electrons, greatly increasing the probability of collisions between electrons and atoms in the working gas (usually argon), thus generating a high-density plasma. Argon ions in the plasma bombard the target material (the coating material) under the influence of an electric field, causing its atoms or molecules to be sputtered and deposited onto the opposite substrate surface, forming a dense, uniform thin film. Due to its advantages such as high deposition rate, low substrate temperature, and good film adhesion, this process is widely used in semiconductors, optical coatings, decoration, and tool wear-resistant coatings.

[0043] In this step, inert argon gas is introduced into the magnetron sputtering system and ionized under high pressure to generate a large number of argon ions. By adjusting the system power, the argon ions can accumulate in a region near the top of the patterned substrate 10, forming an argon ion accumulation layer. The density of the accumulated argon ions is very high, and they are all positively charged. According to Coulomb's law, like charges repel each other. Through this repulsion, the argon ions are directed towards the patterned substrate 10, bombarding it and causing the chemical bonds on the surface of the inclined sidewalls 13 of the pattern to break. This makes the inclined sidewalls 13 of the pattern positively charged, while the gap plane 12 remains electrically neutral because it is not bombarded by argon ions and its chemical bonds are not broken.

[0044] More specifically, step 120 above may include:

[0045] S121. In a magnetron sputtering system, a baffle is used to block the aluminum target and the patterned substrate.

[0046] refer to Figure 2 In Figure a), before argon gas is introduced into the magnetron sputtering system, the aluminum target 17 and the patterned substrate 10 need to be isolated by the baffle 16. This is to prevent some argon ions from falling onto the surface of the patterned substrate 10 and reacting before the argon gas is ionized, and the reaction is not continuous and obvious due to insufficient concentration and other parameters.

[0047] S122. Argon gas with a flow rate of 60-80 sccm is introduced between the baffle and the aluminum target, and the gas pressure of the magnetron sputtering system is controlled within the range of 6-8 × 10⁻⁶. -3 Torr, with a temperature range of 300-350℃, a sputtering power range of 1700w-2000w, a magnetron rotation speed range of 30-35r / min, and a holding time of more than 120s, to form an argon ion accumulation layer on the side of the aluminum target facing the patterned substrate.

[0048] Continue to refer to Figure 2 As shown in Figure a), for the alumina on the aluminum target 17, its desorption energy is Ed≈2.8eV (270kJ / mol). Appropriate temperature, pressure, sputtering power, and collision frequency (magnetron rotation speed) need to be designed so that the dissociated argon ions cannot bombard and remove the alumina film from the aluminum target 17. Instead, the argon ions are attracted to the surface of the aluminum target 17, causing a positive charge accumulation effect and forming an argon ion accumulation layer. Specifically, according to the formula: Where q is the ionic charge, Vs is the sheath voltage, and n is the number of collisions from the sheath to the substrate. It is the mean free path. It is the unit path energy loss rate, which can be calculated: Controlling the air pressure to 6-8 x 10⁻⁶. -3 When the temperature is controlled at 300-350℃, the sputtering power is set to 1700w-2000w, the holding time is greater than 120s, and the magnetron speed is controlled at 30-35r / min, argon ions can be attracted to the surface of the aluminum target 17 without being neutralized (due to the presence of the insulating layer), thus forming a sufficient concentration of argon ions to create a positive charge control layer. Specifically, the ion concentration range of the argon ion accumulation layer is optionally 1~7×10⁻⁶. 16 ions / m².

[0049] S123. Close the baffle and introduce argon gas into the magnetron sputtering system at a flow rate of 100-110 sccm, controlling the gas pressure of the magnetron sputtering system to be 3-5 × 10⁻⁶. -3The Torr temperature range is 400-430℃, the sputtering power range is 1800-2100W, the magnetron speed range is 80r / min, the target spacing is controlled at 3.1-5.2mm, and the time is maintained for 120-150s. This allows the argon ions generated by argon ionization to bombard the patterned substrate under the repulsion of the argon ion accumulation layer, causing the chemical bonds in the tilted sidewalls to break. The tilted sidewalls are positively charged, and the gap plane is electrically neutral.

[0050] refer to Figure 2 In Figure b), the baffle 16 is closed, and argon gas is continuously introduced into the magnetron sputtering system at a certain flow rate. The gas pressure range, temperature range, sputtering power range, and magnetron rotation speed range of the magnetron sputtering system are adjusted. Simultaneously, the distance between the aluminum target 17 and the patterned substrate 10 is controlled. For example, this distance is between 3.1 and 5.2 mm. This operating state is maintained for 120-150 seconds. After these steps, the argon ions generated by argon ionization repel the previously formed argon ion accumulation layer. During this repulsion, a certain accelerating voltage is generated, causing the argon ions to bombard the patterned substrate 10 in the direction of the downward arrow in the figure. After the bombardment is designed with the above parameters, the argon ions can violently bombard the inclined sidewalls 13 of the sapphire patterned substrate, causing the aluminum-oxygen bonds in the inclined sidewalls 13 to break, thus making the inclined sidewalls 13 positively charged. The gap plane 12 is not bombarded by argon ions and therefore remains electrically neutral. The plus sign on the inclined sidewall 13 in the figure indicates positive charge.

[0051] Specifically, taking patterned sapphire substrates as an example, they have multiple crystal planes, such as the A-plane (11-20) and the M-plane (10-10), which have high surface free energies of (3.5–4.0 J / m²) and (3.0–3.2 J / m²) respectively. These planes have loose atomic arrangements, numerous dangling bonds, and strong chemical reactivity. The C-plane (0001) exhibits the highest stability and the lowest surface energy (2.4 J / m²), with a dense atomic arrangement, few dangling bonds, and extremely high chemical stability. Furthermore, in the atomic arrangements of non-C-planes, the content of aluminum dangling bonds is relatively high. According to this formula... After the baffle 16 is closed, the argon ions will be repelled by the positive charge accumulated on the surface of the aluminum target 17, and an accelerating voltage will be generated to bombard the surface of the patterned substrate 10. The designed bombardment energy will etch the non-C side of the patterned substrate 10, causing the Al-O bond on the surface to break and the oxygen atoms to be carried away by the bombardment. In addition, the non-C side is positively charged due to the unsaturated bonds that are rich in aluminum bonds, while the C side remains electrically neutral.

[0052] S130. Argon gas is introduced into the magnetron sputtering system, and the ionization of argon gas is controlled to bombard the aluminum target material, so that the sputtered negatively polarized aluminum atoms are attracted by the electrostatic force of the inclined sidewall and form an aluminum atom film on the inclined sidewall.

[0053] refer to Figure 2 As shown in Figure c), argon gas continues to be introduced into the magnetron sputtering system, and the argon gas is controlled to ionize and generate argon ions, which in turn generate electrons. These argon ions bombard the aluminum target 17, sputtering aluminum atoms from the target. These sputtered aluminum atoms collide with and combine with electrons in the system, forming multiple negatively charged aluminum atoms. The small rectangles in the figure represent aluminum atoms. According to Coulomb's law of attraction between positive and negative charges, the negatively charged aluminum atoms are electrostatically attracted by the positively charged inclined sidewall 13, thus preferentially depositing on the inclined sidewall 13 to form a thin film of aluminum atoms. For the electrically neutral interstitial plane 12, there is no electrostatic attraction in this region, and the probability and speed of aluminum atom deposition on the interstitial plane 12 are greatly reduced. Ultimately, a uniform thin film of aluminum atoms forms on the inclined sidewall 13, while there is almost no film or a very thin film on the interstitial plane 12.

[0054] For more specific details, please refer to [link / reference]. Figure 2 In Figure c), step 130 above can be:

[0055] S131. Argon gas with a flow rate of 20-30 sccm is introduced into the magnetron sputtering system, and the gas pressure of the magnetron sputtering system is controlled to be 1-3 × 10⁻⁶. -3 The temperature range is 300-350℃, the sputtering power range is 1000-1500W, the magnetron rotation speed range is 60r / min, the target spacing is controlled at 7.5-8mm, and the time is maintained for 10-20s, so that the argon ions generated by the ionization of argon gas bombard the aluminum target material, and the sputtered negatively polar aluminum atoms are attracted by the electrostatic force of the inclined sidewall to form an aluminum atom film on the inclined sidewall.

[0056] Argon ions, generated from ionization of argon gas, bombard the aluminum target 17, sputtering out negatively charged aluminum atoms (represented by small rectangles in the diagram). Due to the principle of attraction between opposite charges, these negatively charged aluminum atoms are adsorbed onto the positively charged inclined sidewall 13, forming a thin film of aluminum atoms. The downward arrows indicate that the aluminum atoms are adsorbed onto the inclined sidewall 13.

[0057] Optionally, the thickness of the aluminum atom thin film can range from 1 to 2 nm.

[0058] Through a series of parameter controls, the aluminum atom thin film ultimately formed on the inclined sidewall 13 has a range of 1-2 nm.

[0059] S140. Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to control the ionization of argon and bombardment of the aluminum target, so that the sputtered aluminum atoms react with at least nitrogen to form a first thin film on the gap plane. At the same time, the aluminum atom thin film reacts with nitrogen and oxygen to form a second thin film on the inclined sidewall. The first and second thin films constitute a buffer layer. The first thin film is an aluminum nitride film, and the second thin film is an aluminum oxynitride film. Alternatively, both the first and second thin films are aluminum oxynitride films, and the oxygen content in the first film is less than the oxygen content in the second film.

[0060] Among them, reference Figure 2 Figure d) shows that argon, nitrogen, and oxygen are simultaneously introduced into the magnetron sputtering system, with nitrogen and oxygen serving as reactant gases. The aluminum atom film deposited on the inclined sidewall 13 is exposed to the oxygen and nitrogen environment. Since oxygen is far more reactive than nitrogen, and its positively charged surface further promotes the reaction, oxygen preferentially reacts with the aluminum on the inclined sidewall 13 to form aluminum oxide. Because nitrogen is also present, the aluminum oxide then reacts with nitrogen to form an aluminum oxynitride film on the inclined sidewall 13, which is the second film 15. Simultaneously, argon continues to be controlled to ionize and bombard the aluminum target 17. The sputtered aluminum atoms preferentially react with nitrogen on their way to the patterned substrate to form aluminum nitride. Since the gap plane 12 is electrically neutral and has low chemical reactivity, and most of the aluminum atoms reaching this point have already reacted with nitrogen to form stable aluminum nitride, oxygen has difficulty reacting with it. Finally, an aluminum nitride film is formed on the gap plane 12, which is the first film 14. At this time, the first thin film 14 and the second thin film 15 are formed in different regions on the surface of the patterned substrate 10, constituting a buffer layer on the patterned substrate 10.

[0061] It should be added that the material of the first thin film 14 formed on the gap plane 12 is mainly determined by the oxygen content introduced. If the first thin film 14 to be formed is aluminum nitride, a lower oxygen content can be introduced. When a sufficient amount of oxygen is introduced, some aluminum atoms sputtered to the gap plane 12 can react with excess oxygen and nitrogen during sputtering to form an aluminum oxynitride film, that is, the first thin film 14 is also an aluminum oxynitride film. However, since an aluminum atom film is formed on the inclined sidewall 13, it will preferentially react with oxygen and nitrogen to fully form an aluminum oxynitride film. This results in more aluminum oxynitride and a higher oxygen content on the inclined sidewall 13, while the aluminum oxynitride formed on the gap plane 12 mainly depends on the remaining oxygen for reaction, so it is relatively less and has a lower oxygen content. At this time, it is also possible to form aluminum oxynitride films with different oxygen contents in different areas of the patterned substrate 10, realizing the preparation of a buffer layer with partitioned film formation.

[0062] For more specific details, please refer to [link / reference]. Figure 2In Figure d), step 140 above can be specifically described as follows:

[0063] S1401. Introduce argon gas at a flow rate of 20-30 sccm, oxygen gas at a flow rate of 0.5-2 sccm, and nitrogen gas at a flow rate of 120-200 sccm into the magnetron sputtering system, controlling the gas pressure of the magnetron sputtering system to be within the range of 3.5-4.0 × 10⁻⁶. -3 The temperature range is 650-700℃, the sputtering power range is 4000-4500W, the magnetron speed range is 60r / min, and the target spacing is controlled at 4.5-6mm. This allows the argon gas to ionize and bombard the aluminum target, causing the sputtered aluminum atoms to react with at least nitrogen gas to form the first film on the gap plane. The first film is the aluminum nitride film. The aluminum atom film reacts with nitrogen and oxygen gas to form the second film on the inclined sidewall. The second film is the aluminum oxynitride film. The first film and the second film constitute the buffer layer.

[0064] In the diagram, the pentagon represents nitrogen, and the circle represents oxygen. Oxygen and nitrogen are used as reacting gases. When the oxygen content is low, because oxygen is more reactive than nitrogen, the aluminum atom film on the inclined sidewall 13 reacts with oxygen first to form an aluminum oxide film. The aluminum oxide film then reacts with nitrogen to form an aluminum oxynitride film, which is deposited on the inclined sidewall 13 to obtain the second film 15. Since the oxygen content is low, it is consumed during the formation of the second film 15. Then, the sputtered aluminum atoms react directly with nitrogen to form an aluminum nitride film, which is deposited on the gap plane 12 to obtain the first film 14.

[0065] Figure 3 yes Figure 1 The diagram shows another structural flow chart of the method for preparing the partitioned film buffer layer, see reference. Figure 1 and Figure 3 In Figure d), step 140 above can also be specifically described as follows:

[0066] S1402. Introduce argon gas at a flow rate of 20-30 sccm, oxygen gas at a flow rate of 2-6 sccm, and nitrogen gas at a flow rate of 120-200 sccm into the magnetron sputtering system, controlling the gas pressure of the magnetron sputtering system to be within the range of 3.5-4.0 × 10⁻⁶ sccm. -3The temperature range is 650-700℃, the sputtering power range is 4000-4500W, the magnetron speed range is 60r / min, and the target spacing is controlled at 4.5-6mm. This allows the argon gas to ionize and bombard the aluminum target, causing the sputtered aluminum atoms to react with nitrogen and oxygen to form the first thin film on the gap plane, and the aluminum atom thin film to react with nitrogen and oxygen to form the second thin film on the inclined sidewall. Both the first and second thin films are aluminum oxynitride thin films, and the oxygen content in the first film is less than that in the second film. The first and second thin films constitute the buffer layer.

[0067] When the oxygen content is high, without changing other sputtering environment and physical parameters, the aluminum atom film on the inclined sidewall 13 reacts with oxygen first to form aluminum oxide, and then reacts with nitrogen to form an aluminum oxynitride film, which is deposited on the inclined sidewall 13 to obtain the second film 15. Due to the high oxygen content, a small amount of oxygen will also react with the aluminum atoms obtained from argon ion bombardment of the aluminum target 17, and then react with nitrogen to form an aluminum oxynitride film, which is deposited on the gap plane 12 to obtain the first film 14. In this case, both the first film 14 and the second film 15 are aluminum oxynitride films, the difference being that the oxygen content in the aluminum oxynitride of the first film 14 is less than that in the aluminum oxynitride of the second film 15.

[0068] Figure 4 yes Figure 1 The diagram shows another structural flowchart of the partitioned film-forming buffer layer preparation method. Unlike the embodiments described above, this partitioned film-forming buffer layer is formed on a pit-shaped patterned substrate. The three-dimensional pattern 11 on the patterned substrate 10 is a pit. Similarly, the pit-shaped three-dimensional pattern 11 also has inclined sidewalls 13 and gap planes 12 between adjacent three-dimensional patterns 11. Therefore, through the partitioned film-forming buffer layer preparation method provided by this embodiment of the invention, a second thin film 15 can be formed on the inclined sidewalls 13 of the pit-shaped three-dimensional pattern 11, and a first thin film 14 can be formed on the gap planes 12. Furthermore, as... Figure 4 As shown in Figure d), the first film 14 is an aluminum nitride film, and the second film 15 is an aluminum oxynitride film. Of course, as... Figure 3 In the embodiment shown, the present invention can also form a first thin film 14 and a second thin film 15, both of which are aluminum oxynitride thin films, on a pit-shaped patterned substrate 10 through a corresponding partitioned film buffer layer preparation method. The oxygen content in the first thin film 14 is less than that in the second thin film 15, which will not be shown in the figure here.

[0069] Figure 5 This is a flowchart of another method for preparing a partitioned film-forming buffer layer provided in an embodiment of the present invention. Figure 6 yes Figure 5The structural flow diagram of the partitioned film-forming buffer layer preparation method is shown below. (Refer to...) Figure 5 and Figure 6 This embodiment is an optimization of the previous embodiment. Specifically, before S120 of the above embodiment, the following steps can be added:

[0070] The surface of the aluminum target 17 in the magnetron sputtering system facing the patterned substrate 10 is oxidized to form an aluminum oxide insulating layer.

[0071] Therefore, before S130 in the above embodiment, the following steps need to be added:

[0072] Remove the aluminum oxide insulating layer from the surface of the aluminum target 17.

[0073] For details not covered in this embodiment, please refer to the previous embodiment.

[0074] like Figure 5 As shown, the method for preparing a partitioned film-forming buffer layer provided in this embodiment of the invention includes the following steps:

[0075] S210. A patterned substrate is provided and placed in a magnetron sputtering system; a plurality of three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls, which are non-C-planes; there are gap planes between adjacent three-dimensional patterns, which are C-planes.

[0076] S220. The surface of the aluminum target in the magnetron sputtering system facing the patterned substrate is oxidized to form an aluminum oxide insulating layer.

[0077] refer to Figure 6 In Figure a), the baffle 16 is opened, meaning that in the magnetron sputtering system, the baffle 16 is placed to isolate the aluminum target 17 from the patterned substrate 10. Oxygen is then introduced, causing the side of the aluminum target 17 facing the patterned substrate 10 to begin an oxidation reaction with the oxygen, thereby forming an aluminum oxide insulating layer. It should be noted that the circles in the figure represent oxygen, and the dark rectangular portion below the aluminum target 17 represents the aluminum oxide insulating layer. This aluminum oxide insulating layer prevents argon ions from bombarding the aluminum target 17 during the next step; instead, the ionized argon ions are adsorbed onto the surface of the aluminum target 17.

[0078] Optionally, step S220 above can be refined as follows:

[0079] In the magnetron sputtering system, a baffle 16 is used to block the aluminum target 17 and the patterned substrate 10.

[0080] Oxygen with a flow rate of 50-80 sccm is introduced between the baffle 16 and the aluminum target 17. The temperature of the magnetron sputtering system is controlled to be 250-300℃ and maintained for more than 10-15 seconds, so that the aluminum target 17 reacts with oxygen on the surface of the patterned substrate 10 to generate an aluminum oxide insulating layer.

[0081] Before introducing gas into the magnetron sputtering system, a baffle 16 is used to separate the aluminum target 17 from the patterned substrate to prevent substrate contamination. Then, oxygen is introduced, and the magnetron sputtering system is heated by controlling parameters such as the flow rate and temperature range of the introduced oxygen, so that the oxygen reacts with the aluminum target 17 to generate an aluminum oxide insulating layer.

[0082] Optionally, the thickness of the alumina insulating layer is less than 1 nm.

[0083] For example, in a magnetron sputtering system, the aluminum oxide insulating layer generated by the reaction of oxygen with the aluminum target 17 is very thin, with a thickness range of less than 1 nm.

[0084] S230. In a magnetron sputtering system, an argon ion accumulation layer is formed. The repulsion between argon ions is used to bombard the patterned substrate, causing the chemical bonds in the tilted sidewalls to break. The tilted sidewalls are positively charged, and the gap plane is electrically neutral.

[0085] S240, Remove the aluminum oxide insulating layer from the surface of the aluminum target.

[0086] After Figure 6 After processing the diagram in c), where the inclined sidewall 13 becomes electrically positive and the gap plane 12 becomes electrically neutral, refer to... Figure 6 As shown in Figure d), open the baffle 16, turn off the sputtering power set on the aluminum target 17, and adjust the argon gas flow rate and sputtering power so that the argon gas bombards the aluminum target 17.

[0087] Optionally, step S240 above can be refined as follows:

[0088] The target spacing of the magnetron sputtering system is adjusted to be above 13mm.

[0089] In the magnetron sputtering system, a baffle 16 is used to block the aluminum target 17 and the patterned substrate 10.

[0090] The sputtering power was turned off for 60 seconds to neutralize the argon ions in the argon ion accumulation layer.

[0091] Argon gas with a flow rate of 120-150 sccm is introduced between the baffle 16 and the aluminum target 17. The sputtering power of the magnetron sputtering system is controlled to be above 3000W, the duty cycle of the sputtering voltage is 65%-80%, and it is maintained for more than 150 seconds, so that the argon ions generated by the ionization of argon gas bombard the aluminum target 17 and peel off the aluminum oxide insulating layer from the aluminum target 17.

[0092] Specifically, in the process of removing the alumina insulating layer from the surface of the aluminum target 17, the distance between the aluminum target 17 and the patterned substrate 10 in the magnetron sputtering system is first adjusted to be above 13mm. Increasing the distance prevents high-energy argon ions or detached alumina fragments from sputtering onto the patterned substrate 10, thus protecting the patterned substrate from contamination. Simultaneously, using a baffle 16 to isolate the aluminum target 17 from the patterned substrate also prevents substrate contamination. After introducing argon gas, high power is not immediately applied to prevent the rapid accumulation of argon ions on the insulating alumina layer surface, which could trigger a momentary arc discharge. Therefore, the sputtering power is first turned off for 60 seconds to neutralize the argon ions in the argon ion accumulation layer. After the entire gas environment stabilizes, argon gas is then introduced into the system, and parameters such as the argon gas flow rate, sputtering power, and sputtering voltage duty cycle are controlled. This allows the argon ions generated by the ionization of argon gas to bombard the aluminum target 17, removing the alumina insulating layer and obtaining... Figure 6 In the state of Figure e), the rectangular dark aluminum oxide below the aluminum target 17 disappears.

[0093] S250. Argon gas is introduced into the magnetron sputtering system, and the ionization of the argon gas is controlled to bombard the aluminum target, so that the sputtered negatively polar aluminum atoms are attracted by the electrostatic force of the inclined sidewall and form an aluminum atom film on the inclined sidewall.

[0094] S260. Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to control the ionization of argon and bombardment of the aluminum target, so that the sputtered aluminum atoms react with at least nitrogen to form a first thin film on the gap plane. At the same time, the aluminum atom thin film reacts with nitrogen and oxygen to form a second thin film on the inclined sidewall. The first and second thin films constitute a buffer layer. The first thin film is an aluminum nitride film, and the second thin film is an aluminum oxynitride film. Alternatively, both the first and second thin films are aluminum oxynitride films, and the oxygen content in the first film is less than the oxygen content in the second film.

[0095] Figure 7 This is a flowchart of another method for preparing a partitioned film-forming buffer layer provided in an embodiment of the present invention. Figure 8 yes Figure 7 The structural flow diagram of the partitioned film-forming buffer layer preparation method is shown below. (Refer to...) Figure 7 and Figure 8 This embodiment is an optimization of the previous embodiment. Specifically, before S140 of the above embodiment, the following steps can be added:

[0096] The temperature of the magnetron sputtering system can be changed to adjust the thickness distribution of aluminum atom thin films.

[0097] Based on this, S140 of the above embodiment can be further refined as follows:

[0098] Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to react the aluminum atom thin film with nitrogen and oxygen, forming a second thin film with gradually increasing or decreasing oxygen content in a first direction on the inclined sidewall; wherein, the first direction is the direction perpendicular to the patterned substrate and away from the patterned substrate.

[0099] For details not covered in this embodiment, please refer to the embodiments described above.

[0100] like Figure 7 As shown, the method for preparing a partitioned film-forming buffer layer provided in this embodiment of the invention includes the following steps:

[0101] S310. A patterned substrate is provided and placed in a magnetron sputtering system; multiple three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls that are not C-planes; there are gap planes between adjacent three-dimensional patterns that are C-planes.

[0102] S320. In the magnetron sputtering system, an argon ion accumulation layer is formed. The repulsion between argon ions is used to bombard the patterned substrate, causing the chemical bonds in the tilted sidewalls to break. The tilted sidewalls are positively charged, and the gap plane is electrically neutral.

[0103] S330. Argon gas is introduced into the magnetron sputtering system, and the ionization of the argon gas is controlled to bombard the aluminum target, so that the sputtered negatively polar aluminum atoms are attracted by the electrostatic force of the inclined sidewall and form an aluminum atom film on the inclined sidewall.

[0104] S340. Change the temperature of the magnetron sputtering system to adjust the thickness distribution of the aluminum atom thin film.

[0105] refer to Figure 8 Figure d) shows that the temperature of the magnetron sputtering system affects the surface mobility of aluminum atoms deposited on the patterned substrate 10. Surface mobility refers to the ease and ability of adsorbed atoms to move on the substrate surface. Specifically, in the figure, the double-headed arrows on the aluminum film surface represent the migration of aluminum atoms.

[0106] By adjusting the temperature, the mobility of aluminum atoms on the tilted sidewall 13 of the substrate is controlled, allowing aluminum atoms to migrate appropriately on the sidewall, thereby adjusting the thickness of the aluminum atom film on the tilted sidewall 13, which is beneficial for subsequent processing. Figure 8 Figure e) shows the preparation for depositing a thin film on a patterned substrate 10.

[0107] Specifically, step S340 may optionally include:

[0108] The temperature range of the magnetron sputtering system is controlled at 450-500℃ to cause the aluminum atom film to migrate and form an aluminum atom film with a gradually thickening thickness from top to bottom; or, the temperature range of the magnetron sputtering system is controlled at 700-800℃ to cause the aluminum atom film to volatilize and form an aluminum atom film with a gradually thinning thickness from top to bottom.

[0109] By precisely adjusting the temperature range of the magnetron sputtering system, the migration of aluminum atoms in the thin film can be altered, thereby controlling the thickness of the aluminum atom film.

[0110] S350. Argon, nitrogen and oxygen are introduced into the magnetron sputtering system to react the aluminum atom thin film with nitrogen and oxygen to form a second thin film with gradually increasing or decreasing oxygen content in a first direction on the inclined sidewall; wherein, the first direction is the direction perpendicular to the patterned substrate and away from the patterned substrate.

[0111] Specifically, the aluminum atom thin film forms a second thin film 15 on the inclined sidewall 13 during the reaction of nitrogen and oxygen. During the deposition process, the oxygen content of the second thin film 15 gradually increases or decreases in the first direction of the inclined sidewall 13 by adjusting the flow rate of the introduced oxygen. For example, if the flow rate of the introduced oxygen is controlled to gradually increase from low to high, the oxygen content of the second thin film 15 in the first direction will gradually increase; if the flow rate of the introduced oxygen is controlled to gradually decrease from high to low, the oxygen content of the second thin film 15 in the first direction will gradually decrease.

[0112] In this embodiment, before bombarding the substrate with argon ions generated by argon ionization, oxygen is introduced into the magnetron sputtering system to generate an aluminum oxide film on the aluminum target 17. Appropriate sputtering parameters are adjusted so that during the subsequent argon ion accumulation layer formation and substrate bombardment, the argon ions do not bombard the aluminum target 17, thus ensuring the tilted sidewall 13 of the substrate exhibits electropositive polarity. To form the aluminum film on the tilted sidewall 13, the sputtering parameters are adjusted to control the argon ions to bombard the aluminum target 17 and remove the aluminum oxide. After removal, the sputtering parameters are adjusted again to continue bombarding the aluminum target 17 with argon ions. The negatively polarized aluminum atoms on the aluminum target 17 are ionized and then formed on the tilted sidewall 13 through electrostatic adsorption. Furthermore, by adjusting the sputtering temperature, the migration of aluminum atoms is controlled, changing the thickness of the aluminum film. This allows for flexible adjustment of the film thickness uniformity and precise control of the deposition process. By controlling the flow rate of oxygen, the oxygen content of the second thin film 15 in the first direction is controlled, thereby optimizing the film's performance. Finally, nitrogen, oxygen, and argon are introduced into the sputtering system to react with the aluminum film, thereby forming the second thin film 15 on the inclined sidewall 13 and the first thin film 14 on the gap plane 12, achieving partitioned film formation on the patterned substrate.

[0113] Based on the same inventive concept, and building upon the method for preparing a partitioned film buffer layer provided in the above embodiments, this invention also provides a method for preparing a patterned composite substrate. Figure 9 This is a flowchart illustrating a method for preparing a patterned composite substrate according to an embodiment of the present invention. Figure 10 and Figure 11 yes Figure 9 The diagram shows two structural flowcharts for the fabrication of patterned composite substrates, for reference. Figures 9-11 The method for preparing the patterned composite substrate includes:

[0114] S410. Prepare a patterned substrate; wherein, multiple three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls, the inclined sidewalls are non-C-planes; there are gap planes between adjacent three-dimensional patterns, the gap planes are C-planes.

[0115] Among them, reference Figure 9 , Figure 10 Figure a) and Figure 11As shown in Figure a), the patterned substrate 10 can specifically be a sapphire substrate, i.e., made of aluminum oxide. Other substrates can also be used, including single substrates such as Si, SiC, AlN, and GaN, as well as composite material patterned substrates such as SiO / Sapphire and QST substrates. Taking a sapphire patterned substrate as an example, the three-dimensional pattern 11 on it can be a raised microstructure or a recessed microstructure; this embodiment of the invention is not limited to these. The three-dimensional pattern 11 can be achieved using etching processes, including but not limited to ion milling, plasma etching, reactive ion etching, and chemical etching.

[0116] S420. A buffer layer is prepared on the surface of a patterned substrate using a partitioned film-forming buffer layer preparation method.

[0117] Based on the prepared patterned substrate, the patterned substrate is placed in a magnetron sputtering system, and a buffer layer is formed on the surface of the patterned substrate using the partitioned film-forming buffer layer preparation method provided in this embodiment of the invention. The buffer layer formed by magnetron sputtering technology includes a first thin film 14 and a second thin film 15. The first thin film 14 covers the gap plane 12 of the patterned substrate 10, and the second thin film 15 covers the inclined sidewall 13. The composition of the first thin film 14 and the second thin film 15 differs depending on the oxygen content. (Refer to...) Figure 10 Figure b) shows that when the oxygen content is low, the first film 14 deposited on the interstitial plane 12 is an aluminum nitride film, and the second film 15 deposited on the inclined sidewall 13 is an aluminum oxynitride film. (Reference) Figure 11 As shown in Figure b), when the oxygen content introduced is high, the first film 14 and the second film 15 can both be aluminum oxynitride films, but in this case, the oxygen content in the first film 14 is less than the oxygen content in the second film 15.

[0118] Figure 12 and Figure 13 These are schematic diagrams of two patterned composite substrates provided in embodiments of the present invention, for reference. Figure 12 and Figure 13 The patterned composite substrate is prepared using the patterned composite substrate preparation method provided in the embodiments of the present invention; the patterned composite substrate includes:

[0119] A patterned substrate 10 has multiple three-dimensional patterns 11 formed on its surface; each three-dimensional pattern 11 has an inclined sidewall 13, which is a non-C-plane; and there is a gap plane 12 between adjacent three-dimensional patterns 11, which is a C-plane.

[0120] The buffer layer includes a first film 14 and a second film 15; the first film 14 covers the gap plane 12, and the second film 15 covers the inclined sidewall 13; the first film 14 is an aluminum nitride film, and the second film 15 is an aluminum oxynitride film; or, both the first film 14 and the second film 15 are aluminum oxynitride films, and the oxygen content in the first film 14 is less than the oxygen content in the second film 15.

[0121] It should be added that the three-dimensional pattern 11 shown in the above-described patterned composite substrate 10 and its preparation method, which is a raised microstructure, is only one example. In other embodiments of the present invention, the three-dimensional pattern 11 can also be a pitted microstructure, which will not be illustrated in the accompanying drawings here. Furthermore, the shape of the raised microstructure shown in the figures can be a three-dimensional raised shape such as a cone, pyramid, frustum, truncated cone, or spherical cap, and the pitted microstructure can also be a three-dimensional pit shape such as a cone, pyramid, frustum, truncated cone, or spherical cap. Those skilled in the art can design and select according to actual needs, and reasonable modifications based on the above schemes all fall within the protection scope of the present invention.

[0122] Figure 14 This is a schematic diagram of another patterned composite substrate provided in an embodiment of the present invention, with reference to... Figure 14 Optionally, the oxygen content of the second thin film 15 gradually increases or decreases in the first direction; wherein, the first direction is the direction perpendicular to the patterned substrate and away from the patterned substrate 10.

[0123] Specifically, by controlling the range of oxygen flow, the oxygen content of the second thin film 15 in the first direction is changed. The first direction can be understood as the vertically upward direction in the figure. In this embodiment, by controlling the oxygen content, the oxygen content of the generated second thin film 15 in the first direction is adjusted, thereby enabling the generation of thin films with different compositions and enhancing the flexibility of the buffer layer generation.

[0124] Based on the above preparation method, the present invention also prepared the above patterned composite substrate according to the above preparation method, on which a 25nm buffer layer was sputtered to verify its effectiveness. Figure 15 This is an electronic pattern of a patterned composite substrate provided in an embodiment of the present invention. Figure 16 for Figure 15 The image shown contains elemental spectra at locations on the sidewalls, i.e., locations other than the C-plane. Figure 17 for Figure 15 The elemental content spectrum at the C-plane position, which is the gap in the graphic shown, is based on... Figures 15-17 It is known that the buffer layer in the non-C-plane area of ​​the patterned sidewall contains three elements: nitrogen, oxygen, and aluminum, while the buffer layer in the C-plane area contains only two elements: nitrogen and aluminum. That is, the patterned composite substrate prepared by the patterned composite substrate preparation method provided in this embodiment of the invention effectively realizes the buffer layer of partitioned film formation.

[0125] The technical solution of this invention involves controlling the ionization of argon gas in a magnetron sputtering system. The repulsion between argon ions is used to bombard the substrate. By controlling the sputtering environment and parameters in the magnetron sputtering system, argon ions bombard the inclined sidewall 13 without bombarding the gap plane 12, thereby causing the gap plane 12 and the inclined sidewall 13 to exhibit different physical and chemical states. This controls the reaction priority of the reactive gases oxygen and nitrogen with aluminum atoms. Furthermore, aluminum atoms are sputtered from the aluminum target 17 by bombarding it with argon ions. Due to electrostatic adsorption, an aluminum film is formed on the inclined sidewall 13. Then, argon, oxygen, and nitrogen are continuously introduced into the magnetron sputtering system. By controlling the oxygen content and other sputtering environment and physical parameters, nitrogen and oxygen react with the aluminum film on the inclined sidewall 13 to form a second thin film 15, and a first thin film 14 is formed on the gap plane 12, thus achieving the effect of partitioned film formation on the patterned substrate 10. By changing the oxygen content introduced, when the oxygen content is low, a second thin film 15 of aluminum oxynitride can be formed on the inclined sidewall 13, and a first thin film 14 of aluminum nitride can be formed on the gap plane 12; or, when the oxygen content is high, both the first thin film 14 and the second thin film 15 are aluminum oxynitride films, but the oxygen content in the first thin film 14 is lower than the oxygen content in the second thin film 15, which improves the flexibility of partitioned control of film formation on the patterned substrate 10.

[0126] In summary, the technical solutions provided by the embodiments of the present invention have the following beneficial effects:

[0127] 1. Under the same deposition conditions, using PVD magnetron sputtering technology, it is possible to perform zoned controlled film formation on patterned substrates, forming buffer layer films with different element (Al, O, N) contents on C-side and non-C-side.

[0128] 2. The partitioned buffer layer not only has better film continuity and higher coverage, but also effectively increases the crystal quality and nucleation density of C-face nucleation, and can completely suppress the growth of seed crystals on the sidewalls, suppress stacking faults, and optimize the improvement of dislocations.

[0129] 3. The buffer layer formed by partitioning can reduce the accumulation effect of mixed dislocations, effectively suppress V pits, improve electrical properties, and at the same time improve crystal quality and internal quantum efficiency.

[0130] 4. In the growth of AlN in deep ultraviolet LEDs, AlN achieves zero nucleation in the cavities, which can effectively increase porosity and significantly increase the cavity volume. This can effectively optimize stress. The pores serve as dislocation termination points, allowing penetrating dislocations (TDs) to climb and annihilate at the air gap interface, reducing cracks and optimizing light extraction efficiency and light pattern.

[0131] 5. In the AlN growth of deep ultraviolet LEDs, the oxygen content on the nucleation surface (i.e., the C-surface) can be completely suppressed to form a functionalized cut-off layer, which inhibits the formation of AlON amorphous material during the nucleation process of oxygen elements on the growth surface, and prevents diffusion, dislocations, and the formation of "crater" morphology, thus greatly improving crystal quality and performance.

[0132] 6. This process is applicable to patterned substrates made of multiple materials, including single substrates such as Si, SiC, Sapphire, AlN, and GaN, as well as patterned substrates made of composite materials such as SiO / Sapphire and QST substrates.

[0133] 7. The proportion of elements (Al, O, N) in the buffer layer on the C-side and non-C-side can be adjusted, which can adapt to different equipment and epitaxial conditions and effectively match stress and crystal quality.

[0134] 8. It can reduce the coating and preheating processes in the epitaxial growth process, shortening the time by about 0.5-1 hour, and effectively improving epitaxial production capacity.

[0135] 9. It can achieve a gradient distribution of oxygen content in the sidewall film of the pattern, which can adapt to the stress relief requirements of different epitaxial growth processes.

[0136] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for preparing a partitioned film-forming buffer layer, characterized in that, include: A patterned substrate is provided and placed in a magnetron sputtering system; the surface of the patterned substrate has multiple three-dimensional patterns formed thereon. The three-dimensional graphic has inclined sidewalls, which are non-C-shaped; there are gap planes between adjacent three-dimensional graphics, which are C-shaped. In the magnetron sputtering system, an argon ion accumulation layer is formed. The patterned substrate is bombarded by the repulsive effect between argon ions to break the chemical bonds in the inclined sidewalls. The inclined sidewalls are positively charged, and the gap plane is electrically neutral. Argon gas is introduced into the magnetron sputtering system, and the argon gas is controlled to ionize and bombard the aluminum target, so that the sputtered negatively polar aluminum atoms are attracted by the electrostatic force of the inclined sidewall and form an aluminum atom film on the inclined sidewall. Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to control the ionization of the argon and bombardment of the aluminum target, so that the sputtered aluminum atoms react with at least the nitrogen to form a first thin film on the gap plane. At the same time, the aluminum atom thin film reacts with nitrogen and oxygen to form a second thin film on the inclined sidewall. The first and second thin films constitute a buffer layer. The first thin film is an aluminum nitride film, and the second thin film is an aluminum oxynitride film; or, both the first and second thin films are aluminum oxynitride films, and the oxygen content in the first film is less than the oxygen content in the second film.

2. The preparation method according to claim 1, characterized in that, In the magnetron sputtering system, an argon ion accumulation layer is formed. The patterned substrate is bombarded using the repulsive force between argon ions to break the chemical bonds in the tilted sidewalls. The tilted sidewalls are positively charged, and the gap planes are electrically neutral. The system includes: In the magnetron sputtering system, a baffle is used to separate the aluminum target and the patterned substrate; Argon gas with a flow rate of 60-80 sccm is introduced between the baffle and the aluminum target, and the gas pressure of the magnetron sputtering system is controlled within the range of 6-8 × 10⁻⁶. -3 Torr, with a temperature range of 300-350℃, a sputtering power range of 1700w-2000w, a magnetron rotation speed range of 30-35r / min, and a holding time of more than 120s, to form the argon ion accumulation layer on the side of the aluminum target facing the patterned substrate; Close the baffle and introduce argon gas at a flow rate of 100-110 sccm into the magnetron sputtering system, controlling the gas pressure of the magnetron sputtering system to be within the range of 3-5 × 10⁻⁶. -3 The temperature range of the Torr is 400-430℃, the sputtering power range is 1800-2100W, the magnetron speed range is 80r / min, the target spacing is controlled at 3.1-5.2mm, and the time is maintained for 120-150s, so that the argon ions generated by the ionization of argon gas bombard the patterned substrate under the repulsion of the argon ion accumulation layer, causing the chemical bonds in the inclined sidewalls to break. The inclined sidewalls are positively charged, and the gap plane is electrically neutral.

3. The preparation method according to claim 1, characterized in that, Argon gas is introduced into the magnetron sputtering system, and the argon gas is controlled to ionize and bombard the aluminum target, so that the sputtered negatively charged aluminum atoms are attracted by the electrostatic force of the inclined sidewall to form an aluminum atom film on the inclined sidewall, including: Argon gas with a flow rate in the range of 20-30 sccm is introduced into the magnetron sputtering system, and the gas pressure of the magnetron sputtering system is controlled in the range of 1-3×10⁻⁶. -3 The temperature range is 300-350℃, the sputtering power range is 1000-1500W, the magnetron rotation speed range is 60r / min, the target spacing is controlled at 7.5-8mm, and the time is maintained for 10-20s, so that the argon ions generated by the ionization of argon gas bombard the aluminum target material, and the sputtered negatively polar aluminum atoms are attracted by the electrostatic force of the inclined sidewall to form an aluminum atom film on the inclined sidewall.

4. The preparation method according to claim 1, characterized in that, Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to control the ionization of the argon and bombardment of the aluminum target, causing the sputtered aluminum atoms to react with at least the nitrogen to form a first thin film on the gap plane. Simultaneously, the aluminum atom thin film reacts with nitrogen and oxygen to form a second thin film on the inclined sidewall. The first and second thin films constitute a buffer layer, comprising: Argon gas with a flow rate of 20-30 sccm, oxygen gas with a flow rate of 0.5-2 sccm, and nitrogen gas with a flow rate of 120-200 sccm are introduced into the magnetron sputtering system, and the gas pressure of the magnetron sputtering system is controlled within the range of 3.5-4.0 × 10⁻⁶. - 3 Torr, with a temperature range of 650-700℃, a sputtering power range of 4000-4500W, a magnetron rotation speed range of 60r / min, and a target spacing controlled at 4.5-6mm, is used to ionize and bombard the aluminum target with argon gas, causing the sputtered aluminum atoms to react with at least nitrogen gas to form the first thin film on the gap plane. The first thin film is the aluminum nitride thin film. The aluminum atom thin film is then reacted with nitrogen and oxygen gas to form the second thin film on the inclined sidewall. The second thin film is the aluminum oxynitride thin film. The first and second thin films constitute the buffer layer; or... Argon gas with a flow rate of 20-30 sccm, oxygen gas with a flow rate of 2-6 sccm, and nitrogen gas with a flow rate of 120-200 sccm are introduced into the magnetron sputtering system, and the gas pressure of the magnetron sputtering system is controlled within the range of 3.5-4.0 × 10⁻⁶ sccm. - 3 The temperature range is 650-700℃, the sputtering power range is 4000-4500W, the magnetron speed range is 60r / min, and the target spacing is controlled at 4.5-6mm. This allows the argon gas to ionize and bombard the aluminum target, causing the sputtered aluminum atoms to react with nitrogen and oxygen to form the first thin film on the gap plane, and the aluminum atom thin film to react with nitrogen and oxygen to form the second thin film on the inclined sidewall. Both the first and second thin films are aluminum oxynitride thin films, and the oxygen content in the first film is less than that in the second film. The first and second thin films constitute the buffer layer.

5. The preparation method according to claim 1, characterized in that, In a magnetron sputtering system, an argon ion accumulation layer is formed. The patterned substrate is then bombarded using the repulsive force between argon ions to break the chemical bonds in the tilted sidewalls. Before the tilted sidewalls are positively charged and the gap plane is electrically neutral, the process further includes: The surface of the aluminum target in the magnetron sputtering system facing the patterned substrate is oxidized to form an aluminum oxide insulating layer. In a magnetron sputtering system, an argon ion accumulation layer is formed. The patterned substrate is bombarded using the repulsive force between argon ions to break the chemical bonds in the tilted sidewalls. The tilted sidewalls are positively charged, and the gap plane is electrically neutral. Then, argon gas is introduced into the magnetron sputtering system, and the argon gas is controlled to ionize and bombard the aluminum target. The sputtered negatively charged aluminum atoms are attracted by the electrostatic force of the tilted sidewalls. Before an aluminum atom thin film forms on the tilted sidewalls, the process further includes: Remove the aluminum oxide insulating layer from the surface of the aluminum target.

6. The preparation method according to claim 5, characterized in that, The surface of the aluminum target in the magnetron sputtering system facing the patterned substrate is oxidized to form an aluminum oxide insulating layer, including: In the magnetron sputtering system, a baffle is used to separate the aluminum target and the patterned substrate; Oxygen with a flow rate of 50-80 sccm is introduced between the baffle and the aluminum target, and the temperature of the magnetron sputtering system is controlled to be 250-300℃ and maintained for 10-15 seconds, so that the surface of the aluminum target facing the patterned substrate reacts with the oxygen to generate an aluminum oxide insulating layer. Removing the alumina insulating layer from the surface of the aluminum target material includes: The target spacing of the magnetron sputtering system is adjusted to be above 13mm; In the magnetron sputtering system, a baffle is used to separate the aluminum target and the patterned substrate; Turn off the sputtering power for 60 seconds to neutralize the argon ions in the argon ion accumulation layer; Argon gas with a flow rate of 120-150 sccm is introduced between the baffle and the aluminum target. The sputtering power of the magnetron sputtering system is controlled to be above 3000W, the duty cycle of the sputtering voltage is 65%-80%, and the time is maintained for more than 150 seconds, so that the argon ions generated by the ionization of the argon gas bombard the aluminum target and peel off the alumina insulating layer from the aluminum target.

7. The preparation method according to claim 1, characterized in that, Argon gas is introduced into the magnetron sputtering system, and the argon gas is controlled to ionize and bombard the aluminum target. The sputtered aluminum atoms, carrying negative polarity, are attracted by the electrostatic force of the inclined sidewall, forming an aluminum atom film on the inclined sidewall. Then, argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to control the ionization of the argon gas and bombard the aluminum target, causing the sputtered aluminum atoms to react with at least nitrogen gas to form a first film on the gap plane. Simultaneously, the aluminum atom film reacts with nitrogen and oxygen gas to form a second film on the inclined sidewall. Before the first and second films form a buffer layer, the process further includes: The temperature of the magnetron sputtering system is changed to adjust the thickness distribution of the aluminum atom thin film; Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to control the ionization of the argon and bombardment of the aluminum target, causing the sputtered aluminum atoms to react with at least the nitrogen to form a first thin film on the gap plane. Simultaneously, the aluminum atom thin film reacts with nitrogen and oxygen to form a second thin film on the inclined sidewall. The first and second thin films constitute a buffer layer, comprising: Argon, nitrogen, and oxygen are introduced into the magnetron sputtering system to react the aluminum atom thin film with nitrogen and oxygen, forming a second thin film with a gradually increasing or decreasing oxygen content in a first direction on the inclined sidewall; wherein, the first direction is a direction perpendicular to the patterned substrate and away from the patterned substrate.

8. The preparation method according to claim 7, characterized in that, Changing the temperature of the magnetron sputtering system to adjust the thickness distribution of the aluminum atom thin film includes: The temperature range of the magnetron sputtering system is controlled to be 450-500℃ to cause the aluminum atom film to migrate and form an aluminum atom film with a gradually thickening thickness from top to bottom; or, the temperature range of the magnetron sputtering system is controlled to be 700-800℃ to cause the aluminum atom film to volatilize and form an aluminum atom film with a gradually thinning thickness from top to bottom.

9. A method for preparing a patterned composite substrate, characterized in that, include: A patterned substrate is prepared; wherein, a plurality of three-dimensional patterns are formed on the surface of the patterned substrate; The three-dimensional graphic has inclined sidewalls, which are non-C-shaped; there are gap planes between adjacent three-dimensional graphics, which are C-shaped. The buffer layer is prepared on the surface of the patterned substrate using the partitioned film buffer layer preparation method as described in any one of claims 1-8.

10. A patterned composite substrate, characterized in that, The patterned composite substrate is prepared using the method described in claim 9; the patterned composite substrate comprises: A patterned substrate, wherein a plurality of three-dimensional patterns are formed on the surface of the patterned substrate; the three-dimensional patterns have inclined sidewalls, the inclined sidewalls being non-C-planes; and there are gap planes between adjacent three-dimensional patterns, the gap planes being C-planes; A buffer layer includes a first film and a second film; the first film covers the gap plane, and the second film covers the inclined sidewall; the first film is an aluminum nitride film, and the second film is an aluminum oxynitride film; or, both the first film and the second film are aluminum oxynitride films, and the oxygen content in the first film is less than the oxygen content in the second film; The oxygen content of the second thin film gradually increases or decreases in a first direction; wherein, the first direction is a direction perpendicular to the patterned substrate and away from the patterned substrate.

Images