Substrate processing methods, LED chip substrates and LED products

Abstract

This application discloses a substrate processing method, an LED chip substrate, and an LED product. The substrate processing method includes: a mask fabrication step; a main etching step; an over-etching step; and, after a single main etching step, at least one by-product removal step, and / or, after a single over-etching step, at least one by-product removal step. The by-product removal step includes bombarding the surface of the workpiece to be etched with etching by-products while maintaining second process conditions in a process chamber. The second process gas in the second process conditions is an inert gas. This substrate processing method can produce substrates with relatively flat surfaces.

Description

Technical Field

[0001] This application belongs to the field of semiconductor processing technology, specifically relating to a substrate processing method, an LED chip substrate, and LED products. Background Technology

[0002] Sapphire substrates are the mainstream substrate material in the LED chip field. They can effectively reduce the dislocation density generated in the epitaxial layer, reduce epitaxial defects, and thus significantly improve the crystal quality of the epitaxial layer, thereby enhancing product performance. In the epitaxial process of LED chips, an aluminum nitride layer is usually deposited on the surface of the substrate first to provide a base layer, and then a gallium nitride layer is deposited on the surface of the aluminum nitride layer. The flatness of the substrate surface is closely related to the epitaxial quality. Therefore, how to form a flat substrate surface is a problem that urgently needs to be solved. Summary of the Invention

[0003] The purpose of this application is to provide a substrate processing method, an LED chip substrate, and an LED product. This substrate processing method can be used to process a substrate with a relatively flat surface.

[0004] In a first aspect, embodiments of this application disclose a substrate processing method, the substrate processing method comprising:

[0005] The mask fabrication step involves covering the upper surface of a substrate with a patterned mask layer to form the part to be etched; wherein the substrate is a sapphire substrate, and the patterned mask layer includes multiple cylindrical mask structures that are spaced apart from each other and arranged in a row and column pattern.

[0006] The main etching step involves etching the workpiece to be etched while maintaining the first process conditions in the process chamber to form an intermediate part;

[0007] In the etching step, while maintaining the third process conditions in the process chamber, the intermediate is etched to form a patterned substrate, the patterned substrate comprising a plurality of mutually spaced, row-and-column distributed conical etched patterns.

[0008] After the main etching step is completed in a single run, at least one by-product removal step is performed, and / or, after the over-etching step is completed in a single run, at least one by-product removal step is performed.

[0009] The byproduct removal step includes bombarding the surface of the workpiece to be etched with etching byproducts while maintaining the second process conditions in the process chamber, wherein the second process gas in the second process conditions is an inert gas.

[0010] Secondly, embodiments of this application disclose an LED chip substrate, formed using the aforementioned substrate processing method. The LED chip substrate includes a substrate and a plurality of etched patterns protruding from the upper surface of the substrate. The upper surface of the substrate is planar, and the plurality of etched patterns are spaced apart from each other and arranged in a row-column pattern. Each etched pattern is a conical structure.

[0011] Thirdly, this application discloses an LED product comprising an epitaxial layer and the aforementioned LED chip substrate, wherein the epitaxial layer covers the upper surface of the LED chip substrate.

[0012] This application discloses a substrate processing method, which first covers the upper surface of the substrate with a patterned mask layer to provide a masking effect for the formation of etching patterns on the substrate, thereby realizing pattern transfer. The patterned mask layer includes multiple spaced-apart cylindrical mask structures arranged in a row-column pattern. During subsequent etching, plasma can enter the gaps between the mask structures to etch the sidewalls of the mask structures. Since the gaps between the mask structures are single-sided openings, the etching rate is higher for the portions of the sidewalls of the mask structures further away from the lower surface of the substrate. As the etching process continues, the pattern provided by the cylindrical mask structures for pattern transfer eventually takes on a conical shape, resulting in a patterned substrate comprising a substrate and multiple conical etched patterns spaced apart and arranged in a row-column pattern.

[0013] Furthermore, during the processing, the workpiece to be etched undergoes a main etching step and an over-etching step, respectively. Specifically, the process chamber is kept under the first process condition and the third process condition to etch the workpiece. At the same time, compared with the main etching step, the power of the lower electrode is relatively greater during the over-etching step. This results in a relatively greater kinetic energy of the plasma generated by the process gas in the third process condition, which is beneficial for gradually removing the edges and corners of the etched pattern in the intermediate workpiece, so that the etched pattern gradually approaches the ideal conical structure.

[0014] Furthermore, by performing at least one by-product removal step after completing the main etching step in a single run, and / or performing at least one by-product removal step after completing the over-etching step in a single run, the second process gas in the second process conditions can bombard the by-products on the surface of the workpiece to be etched, thereby preventing the by-products generated during the etching process from affecting the uniformity of the etching process and making the surface of the workpiece to be etched as flat as possible. This allows the surface of the patterned substrate formed using the substrate processing method disclosed in the embodiments of this application to have a relatively flat structure. As a result, when using the patterned substrate for epitaxial processing, the formation quality of the epitaxial layer can be guaranteed to be relatively high, thereby improving the product quality of the semiconductor. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0016] Figure 1 Electron micrographs of the workpiece after only the main etching step has been performed.

[0017] Figure 2 for Figure 1 Electron micrograph of the part to be etched after only the etching step has been performed;

[0018] Figure 3 This is a schematic flowchart of the substrate processing method disclosed in the embodiments of this application;

[0019] Figure 4 Electron micrographs of intermediate components formed in the substrate processing method disclosed in the embodiments of this application;

[0020] Figure 5 This is an electron microscope image of a patterned substrate formed in the substrate processing method disclosed in the embodiments of this application. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0023] As described above, the technical problem this application aims to solve is how to form a relatively flat substrate. Based on research into the above technical problem, the inventors discovered that a patterned sapphire substrate can be formed by sequentially performing a main etching step and an over-etching step. Byproducts generated during the etching process are deposited on the surface of the substrate. Although these byproducts are removed by re-etching, the high randomness of the byproduct deposition distribution results in varying thicknesses of byproducts deposited at different locations on the substrate surface. Therefore, as... Figure 1 and Figure 2 As shown, with the continuous increase of etching time, the etching depth at different locations on the substrate surface varies, resulting in an uneven surface on the substrate, which will have a serious adverse effect on the quality of subsequent epitaxial processes.

[0024] Based on the above, the inventors further improved the substrate processing technology, such as... Figure 3 , and combined Figure 4 and Figure 5 This application discloses a substrate processing method. Using this substrate processing method, a substrate can be processed so that the substrate can be patterned to form a patterned substrate, wherein the substrate is specifically a sapphire substrate.

[0025] To elaborate, substrate processing methods include:

[0026] S1. Mask fabrication step: A patterned mask layer is applied to the upper surface of the substrate to form the part to be etched. That is, in this application, the part to be etched includes the substrate and the patterned mask layer, both of which are etched together. Optionally, the patterned mask layer can be formed by coating, or it can be formed by imprinting, that is, the patterned mask layer is an imprinting mask.

[0027] Furthermore, in the substrate processing method disclosed in this application embodiment, the substrate processed is a sapphire substrate. When forming an LED chip using this substrate, the dislocation density generated in the epitaxial layer can be effectively reduced, and the epitaxial quality can be improved. Accordingly, in order to form the required pattern on the substrate, the patterned mask layer needs to have a corresponding pattern. Specifically, the patterned mask layer includes multiple cylindrical mask structures, which are spaced apart from each other and arranged in a row-column pattern, thereby ensuring that the subsequent etching process can form an etching pattern that is spaced apart and arranged in a row-column pattern on the substrate. Specifically, the diameter and thickness of the mask structure, as well as the spacing between two adjacent mask structures, can be flexibly determined according to actual needs and are not limited here.

[0028] In one specific embodiment, a patterned mask layer can be formed by coating photoresist. More specifically, step S1 above may include:

[0029] Photoresist is coated onto the upper surface of the substrate to form a photoresist layer. Specifically, methods such as spin coating can be used to coat a photoresist layer of a predetermined thickness onto the upper surface of the substrate.

[0030] Subsequently, the photoresist layer is processed by exposure and development, so that the part of the photoresist layer that needs to be used as a mask is retained, and the other parts of the photoresist layer except for the mask are removed, forming a patterned photoresist layer. Accordingly, the patterned photoresist layer includes multiple cylindrical mask structures that are spaced apart from each other and arranged in a row and column pattern.

[0031] Specifically, the thickness of the photoresist layer can be between 2.0 μm and 3.0 μm, and the distance between the centers of any two adjacent cylindrical mask structures in each row and column can be 3.0 μm, and the diameter of the mask structure can be between 2.0 μm and 2.3 μm.

[0032] Following step S1 above, the substrate processing method disclosed in this application further includes:

[0033] S2, the main etching step, involves etching the workpiece to be etched while maintaining the first process conditions in the process chamber to form an intermediate part.

[0034] In the first process condition, the process gas introduced into the process chamber is the first process gas, which is used to generate the first plasma to etch the workpiece. That is, when the process chamber maintains the first process condition, the process that takes place in the process chamber is an etching process, which etches the workpiece from its upper surface.

[0035] Furthermore, during the aforementioned etching process, since a patterned mask layer is provided on the upper surface of the substrate, and the mask structures included in the patterned mask are spaced apart from each other, the first plasma can not only etch the upper surface of the etched part (including the mask structure and the substrate) during the etching process using the first process gas, but also etch the sidewalls of the mask structure by moving to the gap between any two adjacent mask structures.

[0036] Meanwhile, since the etching process produces byproducts, for the etching process of the sidewall of the mask structure, the byproducts generated after the area closer to the upper surface of the sidewall is etched are more easily discharged from the gap, and the first plasma is more likely to enter the area closer to the upper surface of the mask structure. As a result, the etching rate of the area closer to the upper surface of the sidewall of the mask structure is greater.

[0037] Conversely, because the first plasma is less likely to enter the lower part of the gap between the mask structures, and the byproducts generated during the etching process are also less likely to be discharged from the bottom of the mask structure, the etching rate of the part of the sidewall closer to the bottom of the mask structure is also lower. Furthermore, as the etching process continues, the shape of the cylindrical mask structure will change to a structure that is smaller at the top and larger at the bottom, and the difference between the diameter of the lower surface and the diameter of the upper surface of the mask structure will become larger and larger. This ensures that as the processing continues, the mask structure not only provides pattern transfer for the substrate, but also changes the shape of the transferred pattern, and ultimately forms multiple mutually spaced, row-and-column distributed conical etching patterns on the upper half of the substrate.

[0038] Specifically, the first process gas can generate plasma capable of reacting with the workpiece (including the sapphire substrate and the mask layer). Since the mask layer is typically a photoresist layer, its removal by etching is relatively easy, and there is almost no need to consider the type of gas used to etch it separately. Because the main component of the sapphire substrate is aluminum oxide, the first process gas can include boron chloride. The ions generated after boron chloride ionization readily react with aluminum oxide, and the resulting byproducts are mostly gaseous materials, which reduces the difficulty of controlling the etching process. Of course, the first process gas can be a single-component gas, or it can be a mixture of two or more gases.

[0039] Therefore, to improve etching efficiency and etching effect, the first process gas may also include trifluoromethane. That is, the first process gas includes boron chloride and trifluoromethane. In this case, the reactions that occur after the first process gas is introduced into the process chamber include:

[0040] BCl3↑→BCl x +↓+Cl-↑(x=0,1,2);

[0041] Al₂O₃↓+BCl x +↑→Al3+↑+BOCl z +↑+Cl-↑(z=1,2,3);

[0042] Cl-↑+Al3+↑→AlCl3↓;

[0043] CHF3↑→CHF m +↑+F-↑(m=0,1,2);

[0044] Al3+↑+F-↑→AlF3↓;

[0045] Of course, the first process gas, in the case of boron chloride, may also include hydrogen and dichloromethane, but not trifluoromethane. The assembly method of these first process gases can ensure that the workpiece can be etched normally. In general, the first process gas includes boron chloride, or the first process gas includes boron chloride and also includes at least one of trifluoromethane, hydrogen, and dichloromethane.

[0046] After step S2, a portion of the etched part can be etched away to form an intermediate part. To this end, compared with the etched part, the substrate of the intermediate part has etched trenches. The etched trenches correspond to the gaps between the mask structures in the patterned mask layer. The size of the mask structure in the intermediate part is smaller. At the same time, the diameter of the upper surface of the mask structure is smaller than the diameter of its lower surface, that is, the mask structure is in a state of being smaller at the top and larger at the bottom.

[0047] Following step S2, the intermediate part formed after step S2 of the etched part needs to be further processed to form the patterned substrate required in this application. Therefore, the substrate processing method disclosed in the above embodiments further includes:

[0048] S3. Over-etching step: Under the condition of maintaining the third process conditions in the process chamber, the intermediate part is etched to form a patterned substrate, corresponding to the above-mentioned patterned mask layer. Based on the etching principle, the patterned substrate formed after the over-etching step includes multiple mutually spaced and arranged in a row-column pattern of conical etched patterns.

[0049] In the third process condition, the process gas introduced into the process chamber is the third process gas, which is used to generate the third plasma to etch the intermediate part. That is, while maintaining the third process condition in the process chamber, the process inside the process chamber is also an etching process, and the intermediate part is etched from the upper surface of the intermediate part.

[0050] Furthermore, in the initial stage of the aforementioned etching process, since a portion of the mask layer may still exist on the upper surface of the substrate, and the mask structures are all spaced apart, the substrate has etching trenches. Therefore, during the etching of the intermediate part using the third process gas, the sidewalls of the etching trenches in the substrate can be further etched, expanding the width of the etching trenches. Subsequently, as the etching process continues, the mask layer can eventually be completely etched away, causing the depth of the etching trenches on the substrate to continuously increase. The width of the etching trenches becomes larger towards the bottom surface of the substrate and smaller towards the bottom surface, ensuring that the patterned substrate includes multiple conical etching patterns that correspond to the mask structures, are spaced apart from each other, and are distributed in a row-and-column pattern.

[0051] Optionally, similar to the first process gas, the third process gas may include boron chloride to reduce the difficulty of etching control of intermediate parts. Of course, when the third process gas includes boron chloride, in order to improve etching efficiency, the third process gas may also include at least one of trifluoromethane, hydrogen, and dichloromethane; this is not limited herein.

[0052] In addition, the lower electrode power in the third process condition needs to be greater than that in the first process condition, so that the kinetic energy of the plasma during the etching process in step S3 is greater than that of the plasma during the etching process in step S2. This makes the plasma in step S3 have a relatively stronger etching effect, so that the corners and edges of the etched pattern can be gradually removed in step S3, thereby making the etched pattern tend to be a more ideal conical shape.

[0053] After step S3, the remaining mask layer on the intermediate component can be completely removed, and the depth and width of the etching trenches on the intermediate component can be further increased, thereby forming a patterned substrate. More specifically, the patterned substrate includes a substrate and multiple etching patterns protruding from the upper surface of the substrate. The upper surface of the substrate is planar, and the multiple etching patterns are spaced apart and distributed in a row-column pattern. Each etching pattern is a conical structure. It should be noted that the upper surface of the substrate is the internal structure of the substrate before etching. By forming etching trenches on the substrate, some of the internal structure of the substrate is exposed, thereby forming a "new upper surface," which is the upper surface of the substrate. Furthermore, the substrate and the multiple etching patterns are an integral structure. In this application, in order to distinguish the various functional parts in the patterned substrate, they are artificially divided into two structures, but in reality, there is no clear boundary between the two structures.

[0054] Furthermore, in order to ensure that the surface of the substrate formed after the above steps S2 and S3 is relatively flat, the substrate processing method disclosed in this application embodiment further includes:

[0055] S4. After a single main etching step is completed, at least one by-product removal step is performed, and / or after a single over-etching step is completed, at least one by-product removal step is performed. The by-product removal step includes: bombarding the surface of the workpiece to be etched with etching by-products while maintaining the second process conditions in the process chamber, wherein the second gas in the second process conditions is an inert gas.

[0056] The second process gas is primarily used to bombard the etched part to remove byproducts from its surface. Therefore, it is crucial that the second process gas does not react with the etched part. Based on this, as mentioned above, the second process gas is an inert gas. Optionally, the second process gas includes argon to reduce production costs while meeting requirements. Correspondingly, after the second process gas is introduced into the process chamber, the resulting reactions include:

[0057] Ar↑→Ar+↑+e-;

[0058] Of course, the second process gas can also include neon or krypton, etc.

[0059] After the second process gas is introduced into the process chamber, it can be ionized to generate ions. Under the action of the lower electrode power, these ions move towards the workpiece being etched and eventually collide with it, removing etching byproducts from the surface of the workpiece through bombardment. Since the substrate used in this embodiment is a sapphire substrate, which has relatively high hardness and strong resistance to bombardment, the sapphire substrate is almost never damaged during the process of using the second process gas to bombard the workpiece to remove etching byproducts. Of course, to further prevent the sapphire substrate from being damaged by the second plasma, the lower electrode power can be controlled according to the actual process to ensure that the second plasma can remove etching byproducts without damaging the sapphire substrate.

[0060] As described above, the byproduct removal step can be performed at least once after the main etching step is completed in a single operation. In this case, the process chamber can switch the process conditions from the first process condition to the second process condition after completing one main etching step. Of course, some process parameters may be the same in the two process conditions, or neither process parameter may be the same.

[0061] In one specific embodiment of this application, the time for a single execution of the main etching step can be 60-120s, and the time for a single execution of the byproduct removal step can be 30-60s. Based on this, the process chamber can be switched to maintain the second process condition for 30-60s after maintaining the first process condition for 60-120s. This allows the byproduct removal step to remove byproducts generated and attached to the surface of the substrate during the etching process, preventing the byproducts from affecting the subsequent etching process and ensuring that the surface of the etched part remains relatively flat.

[0062] Furthermore, the main etching step and the byproduct removal step can be performed alternately. That is, the process chamber can be alternately maintained under the first process conditions and the second process conditions to provide a corresponding process environment for the workpiece to be etched in the process chamber. The holding time of the first process conditions and the second process conditions can be determined according to the actual situation.

[0063] When adopting the above scheme, if Figure 4As shown, while ensuring a relatively smooth surface on the intermediate part formed after the main etching step, high etching efficiency can also be achieved. Accordingly, by repeatedly alternating between the first and second process conditions in the process chamber, the workpiece to be etched can be etched, forming an intermediate part. The number of alternations between the two process conditions can be determined based on the actual situation, specifically 10 to 20 times, which can further balance etching efficiency and etching effect.

[0064] If at least one byproduct removal step is performed after the main etching step is completed in a single step, the timing for the completion of the main etching step can be determined by controlling the total time of the main etching step. Alternatively, the timing for the completion of the main etching step can be determined by using the etching depth of the trench on the intermediate part as a reference.

[0065] More specifically, as described above, a patterned mask layer can be formed using photoresist, and the thickness of the photoresist layer can be 2.0 μm to 3.0 μm. In this case, when the depth of the etching trench on the intermediate part is in the range of 1.2-1.7 μm, it can be considered that the main etching step can be ended.

[0066] As mentioned above, the byproduct removal step can also be performed at least once after a single over-etching step. In this case, the process chamber can switch the process conditions from the third process condition to the second process condition after completing one over-etching step. Of course, some process parameters may be the same in the two process conditions, or neither process parameter may be the same.

[0067] In one specific embodiment of this application, the time for a single etching step can be 60-120s, and the time for a single byproduct removal step can be 30-60s. Based on this, the process chamber can be switched to maintain the second process condition for 30-60s after maintaining the third process condition for 60-120s, thereby removing byproducts generated on the substrate and attached to its surface during the etching process by means of the byproduct removal step.

[0068] Furthermore, the over-etching step and the by-product removal step can be performed alternately; that is, the process chamber can be alternately cyclically maintained under the third and second process conditions to etch the intermediate part and form a patterned substrate, and as... Figure 5 As shown, this ensures that the surface of the patterned substrate formed is relatively smooth and flat. The number of alternations between the two process conditions can be determined based on the actual situation, specifically 5 to 10 times, to balance etching effect and etching efficiency.

[0069] Accordingly, the timing of completing the over-etching step can be determined based on the morphology of the etched pattern in the etched substrate. Specifically, as described above, a patterned mask layer can be formed using photoresist, with a photoresist layer thickness of 2.0 μm to 3.0 μm. When the main etching step is completed, the depth of the etched trenches on the intermediate part is in the range of 1.2 μm to 1.7 μm. In this case, when the intermediate part is processed into the substrate until the etched pattern protruding from the upper surface is conical in shape, with a height of 1.6 μm to 1.9 μm and a bottom width of 2.6 μm to 2.9 μm, it can be considered that a patterned substrate has been formed. At this point, the over-etching step can be terminated.

[0070] This application discloses a substrate processing method, which first covers the upper surface of the substrate with a patterned mask layer to provide a masking effect for the formation of etching patterns on the substrate, thereby realizing pattern transfer. The patterned mask layer includes multiple spaced-apart cylindrical mask structures arranged in a row-column pattern. During subsequent etching, plasma can enter the gaps between the mask structures to etch the sidewalls of the mask structures. Since the gaps between the mask structures are single-sided openings, the etching rate is higher for the portions of the sidewalls of the mask structures further away from the lower surface of the substrate. As the etching process continues, the pattern provided by the cylindrical mask structures for pattern transfer eventually takes on a conical shape, resulting in a patterned substrate comprising a substrate and multiple conical etched patterns spaced apart and arranged in a row-column pattern.

[0071] Furthermore, during the processing, the workpiece to be etched undergoes a main etching step and an over-etching step, respectively. Specifically, the process chamber is kept under the first process condition and the third process condition to etch the workpiece. At the same time, compared with the main etching step, the power of the lower electrode is relatively greater during the over-etching step. This results in a relatively greater kinetic energy of the plasma generated by the process gas in the third process condition, which is beneficial for gradually removing the edges and corners of the etched pattern in the intermediate workpiece, so that the etched pattern gradually approaches the ideal conical structure.

[0072] Furthermore, by performing at least one by-product removal step after completing the main etching step in a single run, and / or performing at least one by-product removal step after completing the over-etching step in a single run, the second process gas in the second process conditions can bombard the by-products on the surface of the workpiece to be etched, thereby preventing the by-products generated during the etching process from affecting the uniformity of the etching process and making the surface of the workpiece to be etched as flat as possible. This allows the surface of the patterned substrate formed using the substrate processing method disclosed in the embodiments of this application to have a relatively flat structure. As a result, when using the patterned substrate for epitaxial processing, the formation quality of the epitaxial layer can be guaranteed to be relatively high, thereby improving the product quality of the semiconductor.

[0073] In the above embodiments, both the etched part and the intermediate part are located in the process chamber, and during the processing of both, the process chamber is set with corresponding process conditions. These process conditions typically include chamber pressure, upper electrode power, lower electrode power, and the type and flow rate of the gas. Of course, to ensure that the temperature of the etched part and the intermediate part does not become relatively high during etching, helium gas can be introduced below the etched part to provide cooling; the helium pressure can be 3-7 Torr. Additionally, a cooler can be provided to further cool the etched part; the cooler's set temperature can be 0-40°C.

[0074] During substrate processing, various parameters within the process chamber can be comprehensively considered. Optionally, in the first process condition, the pressure range of the process chamber can be 2-3 mTorr, the upper electrode power range can be 1200-2000 W, the lower electrode power range can be 300-600 W, and the first process gas can include boron chloride and trifluoromethane, with the boron chloride flow rate being 100-150 sccm and the trifluoromethane flow rate being 5-20 sccm. Using the above process formulation, the etching efficiency and etching effect of the etched part are relatively high.

[0075] Optionally, in the second process conditions, the pressure range of the process chamber can be 2-3 mTorr, the power range of the upper electrode can be 1200-2000W, the power range of the lower electrode can be 50-200W, and the second process gas can include argon gas with a flow rate of 50-100 sccm. This makes the removal of etching byproducts relatively thorough and efficient, and will not damage the substrate.

[0076] Optionally, in the third process conditions, the pressure range of the process chamber can be 2-3 mTorr, the upper electrode power range can be 1200-2000 W, the lower electrode power range can be 700-1000 W, and the third process gas can include boron chloride and trifluoromethane, with a boron chloride flow rate of 60-120 sccm and a trifluoromethane flow rate of 3-10 sccm. Using the above process formulation, the etching efficiency and etching effect of the intermediate part are relatively high, and it is beneficial to form an ideal conical structure for the etched pattern.

[0077] Based on the substrate processing method disclosed in any of the above embodiments, this application also discloses an LED chip substrate, which is formed using the substrate processing method disclosed in any of the above embodiments. Specifically, the LED chip substrate is made of sapphire and includes a substrate and multiple etched patterns protruding from the upper surface of the substrate. The upper surface of the substrate is planar, and the multiple etched patterns are spaced apart from each other. Furthermore, the multiple etched patterns are arranged in a row-column pattern, each etched pattern has a conical structure, and the surface of each etched pattern is relatively flat and smooth. More specifically, in the LED chip substrate, the shape and size of each etched pattern are basically the same, the height of the etched pattern is 1.6-1.9 μm, and the bottom width of the etched pattern is 2.6-2.9 μm. This substrate can provide an ideal growth platform for the epitaxial layer of LED chips and is suitable for MOCVD epitaxial growth of LED chips such as white LEDs, blue LEDs, green LEDs, MiniLEDs, and MicroLEDs.

[0078] Based on the aforementioned LED chip substrate, this application also discloses an LED product, which can specifically be an LED chip. The LED product includes an epitaxial layer and the aforementioned LED chip substrate, with the epitaxial layer covering the upper surface of the LED chip substrate. Specifically, the epitaxial layer can be formed on the upper surface of the LED chip substrate using an epitaxial process, and the specific material of the epitaxial layer can be GaN.

[0079] More specifically, in the process of forming the epitaxial layer, an AlN layer with a thickness of 1-20 nm can first be deposited on the upper surface of the LED chip substrate to provide a base layer and reduce the processing difficulty of the epitaxial layer. Then, the GaN epitaxial layer is grown, with a thickness of 4-5 μm. The GaN epitaxial layer grows vertically from the bottom platform of the substrate, starting from the AlN surface, ultimately obtaining the desired high-quality LED chip.

[0080] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0081] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A substrate processing method, characterized in that, The substrate processing method includes: The mask fabrication step involves covering the upper surface of a substrate with a patterned mask layer to form the part to be etched; wherein the substrate is a sapphire substrate, and the patterned mask layer includes multiple cylindrical mask structures that are spaced apart from each other and arranged in a row and column pattern. The main etching step involves etching the workpiece to be etched under the condition that the first process conditions are maintained in the process chamber to form an intermediate part. The first process gas in the first process conditions includes boron chloride. In the etching step, while maintaining the third process conditions in the process chamber, the intermediate is etched to form a patterned substrate. The patterned substrate includes multiple mutually spaced and arranged in a row-and-column pattern of conical etched patterns. The third process gas in the third process conditions includes boron chloride. After the main etching step is completed in a single run, at least one by-product removal step is performed, and / or, after the over-etching step is completed in a single run, at least one by-product removal step is performed; wherein the by-product removal step includes: bombarding the surface of the workpiece to be etched with etching by-products while maintaining the second process conditions in the process chamber, wherein the second process gas in the second process conditions is an inert gas.

2. The substrate processing method according to claim 1, characterized in that, The main etching step and the byproduct removal step are performed alternately; The process chamber maintains the first process condition for 60-120 seconds at a time, and the process chamber maintains the second process condition for 30-60 seconds at a time.

3. The substrate processing method according to claim 2, characterized in that, The main etching step and the byproduct removal step are performed alternately 10 to 20 times.

4. The substrate processing method according to any one of claims 1-3, characterized in that, The over-etching step and the by-product removal step are performed alternately; The process chamber maintains the third process condition for 60-120 seconds at a time, and the process chamber maintains the second process condition for 30-60 seconds at a time.

5. The substrate processing method according to claim 4, characterized in that, The over-etching step and the by-product removal step are performed alternately 5 to 10 times.

6. The substrate processing method according to claim 1, characterized in that, The first process gas also includes at least one of trifluoromethane, hydrogen, and dichloromethane; Alternatively, the third process gas may also include at least one of trifluoromethane, hydrogen, and dichloromethane.

7. The substrate processing method according to claim 1, characterized in that, The second process gas includes at least one of argon, neon, or krypton.

8. The substrate processing method according to claim 1, characterized in that, In the first process conditions, the pressure range of the process chamber is 2-3 mT, the power range of the upper electrode is 1200-2000 W, the power range of the lower electrode is 300-600 W, and the first process gas includes boron chloride and trifluoromethane, with a boron chloride flow rate of 100-150 sccm and a trifluoromethane flow rate of 5-20 sccm. And / or, in the third process conditions, the pressure range of the process chamber is 2-3 mT, the upper electrode power range is 1200-2000 W, the lower electrode power range is 700-1000 W, and the third process gas includes boron chloride and trifluoromethane, with a boron chloride flow rate of 60-120 sccm and a trifluoromethane flow rate of 3-10 sccm.

9. The substrate processing method according to claim 1, characterized in that, In the second process conditions, the pressure range of the process chamber is 2-3 mT, the power range of the upper electrode is 1200-2000 W, the power range of the lower electrode is 50-200 W, and the second process gas includes argon with a flow rate of 50-100 sccm.

10. An LED chip substrate, characterized in that, The LED chip substrate is formed by processing the substrate according to any one of claims 1-9. The LED chip substrate includes a substrate and a plurality of etched patterns protruding from the upper surface of the substrate. The upper surface of the substrate is planar. The plurality of etched patterns are spaced apart from each other and are distributed in a row and column manner. Each etched pattern is a conical structure.

11. The LED chip substrate according to claim 10, characterized in that, The height of the etched pattern is 1.6-1.9 μm, and the bottom width of the etched pattern is 2.6-2.9 μm.

12. An LED product, characterized in that, It includes an epitaxial layer and an LED chip substrate as described in claim 10 or 11, wherein the epitaxial layer covers the upper surface of the LED chip substrate.

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