Composite patterned substrate and tilt angle control method thereof

Abstract

This invention discloses a composite patterned substrate and its tilt angle control method. The method includes providing a composite substrate; the composite substrate includes a substrate and a heterolayer; forming a photoresist layer on the surface of the composite substrate and patterning the photoresist layer to form a photoresist pillar mask; using a first etching process, by introducing at least a first etching gas into the reaction chamber of the first etching process, adjusting the etching rate of the heterolayer and the photoresist pillar mask, so that the tilt angle of the heterolayer is at a first preset angle; using a second etching process, by introducing at least a first etching gas into the reaction chamber of the second etching process, removing the photoresist pillar mask, and making the tilt angle of the heterolayer at a first target angle, and the tilt angle of the substrate at a second target angle. Using the above method, through the main second etching process, precise control of the tilt angle of the heterolayer and the substrate tilt angle is achieved, forming different types of heterolayer and substrate tilt angle patterned structures, providing possibilities for multi-scenario applications of composite patterned substrates.

Description

Technical Field

[0001] This invention relates to the technical field of composite patterned substrates, and more particularly to a composite patterned substrate and a method for controlling its tilt angle. Background Technology

[0002] Patterned sapphire substrates (PSS) are one of the core technologies for improving LED light extraction efficiency (LEE). By designing micro- and nano-structures on the substrate surface (such as conical or pyramidal shapes), the total internal reflection (TIR) ​​effect can be disrupted, increasing the photon escape probability and thus significantly improving external quantum efficiency (EQE). In high-end applications such as automotive lighting and Micro-LEDs, the precision requirements for patterned structures are becoming increasingly stringent, especially the precise control of sidewall tilt angles (α) and radians (R value), which directly affect axial light extraction intensity and epitaxial quality. Composite structures utilizing low-refractive-index materials (Si3N4, SiO2, etc.) can achieve larger total internal reflection angles, thereby increasing axial light extraction efficiency and further improving luminous efficacy. In the patterning process for fabricating composite structures, traditional wet etching is prone to over-etching of sidewalls. The etching rate mismatch between the low-refractive-index layer (such as Si3N4, SiO2) and the substrate material leads to pattern transfer distortion, making it difficult to meet the patterning requirements of composite structures (such as sapphire substrate + low-refractive-index heterolayer). Although dry etching has the potential for high precision in pattern transfer, the tilt angle matching problem between the heterolayer and the substrate still exists. Summary of the Invention

[0003] This invention provides a composite patterned substrate and its tilt angle control method to achieve precise control of the tilt angle between the heterolayer and the substrate in the composite pattern, and completes the high-fidelity transfer of the tilt angle between the heterolayer and the substrate in the composite structure substrate. It effectively solves the problem of the complexity of the process of the multilayer mask technology currently used to control the tilt angle of the sidewall of the composite structure, and provides flexible selection for different application scenarios of the composite patterned structure.

[0004] In a first aspect, the present invention provides a method for controlling the tilt angle of a composite patterned substrate, comprising:

[0005] A composite substrate is provided; the composite substrate includes a substrate and a heterolayer located on one side of the substrate;

[0006] A photoresist layer is formed on the surface of a composite substrate, and the photoresist layer is patterned to form a photoresist pillar mask;

[0007] Using the first etching process, at least a first etching gas is introduced into the reaction chamber of the first etching process to adjust the etching rate of the heterolayer and the photoresist mask, so that the tilt angle of the heterolayer is at a first preset angle α1.

[0008] Using a second etching process, at least a first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1; α4 < α1; the tilt angle of the substrate is the angle between the plane where the bottom surface of the substrate is located and the plane where the sidewall of the substrate is located, and the tilt angle of the heterolayer is the angle between the plane where the bottom surface of the heterolayer is located and the plane where the sidewall of the heterolayer is located, and the angle is an acute angle.

[0009] Optionally, using a first etching process, by introducing at least a first etching gas into the reaction chamber of the first etching process, the etching rate of the heterolayer and the photoresist mask is adjusted so that the tilt angle of the heterolayer is at a first preset angle α1, including:

[0010] By introducing a first etching gas and a second etching gas at preset flow rates into the reaction chamber of the first etching process, a passivation layer is formed on the sidewall of the heterolayer under the first preset conditions. The etching rates of the adhesive column mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is at a second preset angle α2.

[0011] Stop the supply of the second etching gas, and under the second preset conditions, reduce the etching rate at the top of the adhesive column mask and the longitudinal etching rate of the heterolayer, so that the tilt angle of the heterolayer is at the third preset angle α3.

[0012] While maintaining the cessation of the second etching gas supply, under the third preset condition, the lateral etching rate of the heterolayer is increased so that the tilt angle of the heterolayer is at the first preset angle α1; α2=α3>α1.

[0013] Optionally, the first preset condition includes an upper RF power range of 1000W-1500W, a lower RF power range of 700W-900W, and a response time of 200s-300s; the second preset condition includes an upper RF power range of 1000W-1500W, a lower RF power range of 700W-900W, and a response time of 350s-600s; the third preset condition includes an upper RF power range of 1000W-1500W, a lower RF power range of 200W-350W, and a response time of 200s-300s.

[0014] Optionally, using a second etching process, at least a first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist pillar mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1, including:

[0015] By introducing a first etching gas with a preset flow rate into the reaction chamber of the second etching process, under the fourth preset conditions, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is at the first target angle α4, and the tilt angle of the substrate is at the second target angle β1; α4=β1.

[0016] Optionally, using a second etching process, at least a first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist pillar mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1, including:

[0017] By introducing a first etching gas with a preset flow rate into the reaction chamber of the second etching process, under the fourth preset conditions, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is the fourth preset angle α5 and the tilt angle of the substrate is the fifth preset angle β2.

[0018] A first etching gas and a second etching gas with a preset flow rate are introduced into the reaction chamber of the second etching process. Under the fifth preset condition, the bottom tilt angle of the substrate is reduced so that the tilt angle of the heterolayer is at the first target angle α4 and the tilt angle of the substrate is at the second target angle β1; α4=α5=β2>β1.

[0019] Optionally, the fourth preset condition is that the upper RF power range is 1000W-1500W and the lower RF power range is 400W-700W; the fifth preset condition is that the upper RF power range is 1000W-1500W and the lower RF power range is 400W-700W.

[0020] Optionally, using a first etching process, by introducing at least a first etching gas into the reaction chamber of the first etching process, the etching rate of the heterolayer and the photoresist mask is adjusted so that the tilt angle of the heterolayer is at a first preset angle α1, including:

[0021] By introducing a first etching gas with a preset flow rate into the reaction chamber of the first etching process, and under the sixth preset condition, the etching rate of the photoresist mask and the heterolayer is adjusted so that the tilt angle of the heterolayer is at the sixth preset angle α6.

[0022] Under the seventh preset condition, the etching rate at the top of the adhesive pillar mask and the longitudinal etching rate of the heterolayer are reduced, so that the tilt angle of the heterolayer is at the first preset angle α1; α1 < α6;

[0023] Using a second etching process, at least a first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist pillar mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1, including:

[0024] Increase the flow rate of the first etching gas, and under the eighth preset condition, remove the photoresist pillar mask to increase the etching rate difference between the substrate and the heterolayer, so that the tilt angle of the heterolayer is at the first target angle α4 and the tilt angle of the substrate is at the second target angle β1; α4 < β1.

[0025] Optionally, the sixth preset condition is an upper RF power range of 1000W-1500W, a lower RF power range of 400W-700W, and a response time of 200s-300s; the seventh preset condition is an upper RF power range of 1000W-1500W, a lower RF power range of 200W-350W, and a response time of 350s-600s; the eighth preset condition is an upper RF power range of 1000W-1500W, and a lower RF power range of 700W-900W.

[0026] Optionally, the preset flow rate of the first etching gas is 90 sccm-120 sccm, and the flow rate of the second etching gas is 10 sccm-25 sccm.

[0027] Optionally, the first etching gas includes at least boron trichloride gas or a mixture of chlorine and boron trichloride; and / or, the second etching gas includes at least nitrogen.

[0028] Secondly, the present invention provides a composite patterned substrate, which is prepared by the above-described tilt angle control method for composite patterned substrates.

[0029] The technical solution of this invention provides a composite substrate, comprising a substrate and a heterolayer located on one side of the substrate. A photoresist layer is formed on the surface of the composite substrate, and the photoresist layer is patterned to form a photoresist pillar mask. At least a first etching gas is introduced into the reaction chamber of a first etching process to adjust the etching rate of the heterolayer and the photoresist pillar mask, so that the tilt angle of the heterolayer is at a first preset angle α1. Using a second etching process, at least the first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist pillar mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1; the first target angle α4 is less than the first preset angle α1. Using the above method, through the main second etching process, precise control of the tilt angle of the heterolayer and the substrate is achieved at each stage, ensuring the accuracy of the final target tilt angles of the heterolayer and the substrate. This achieves high-fidelity transfer of the tilt angles of the heterolayer and the substrate in the composite structure substrate, providing flexible options for different application scenarios of the composite patterned structure.

[0030] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of a tilt angle control method for a composite patterned substrate provided in an embodiment of the present invention;

[0033] Figure 2 A fabrication process diagram of a method for controlling the tilt angle of a composite patterned substrate provided in an embodiment of the present invention;

[0034] Figure 3 A flowchart illustrating another tilt angle control method for a composite patterned substrate provided in an embodiment of the present invention;

[0035] Figure 4 for Figure 3 Fabrication process diagram of the corresponding tilt angle control method for composite patterned substrates;

[0036] Figure 5 for Figure 4 A schematic diagram showing the parameter changes during the corresponding preparation process;

[0037] Figure 6 A flowchart illustrating another tilt angle control method for a composite patterned substrate provided in an embodiment of the present invention;

[0038] Figure 7 for Figure 6 Fabrication process diagram of the corresponding tilt angle control method for composite patterned substrates;

[0039] Figure 8 for Figure 7 A schematic diagram showing the parameter changes during the corresponding preparation process;

[0040] Figure 9 A flowchart illustrating another tilt angle control method for a composite patterned substrate provided in an embodiment of the present invention;

[0041] Figure 10 for Figure 9 Fabrication process diagram of the corresponding tilt angle control method for composite patterned substrates;

[0042] Figure 11 for Figure 10 A schematic diagram showing the parameter changes during the corresponding preparation process;

[0043] Figures 12-14The diagram shows the structure of three composite patterned substrates provided in the embodiments of the present invention. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0046] In one embodiment, Figure 1 This is a flowchart of a tilt angle control method for a composite patterned substrate provided in an embodiment of the present invention. Figure 2 This is a fabrication process diagram of a method for controlling the tilt angle of a composite patterned substrate provided in an embodiment of the present invention. This embodiment is applicable to situations where precise control of the tilt angle of the heterolayer and the substrate is achieved to improve production efficiency, such as... Figure 1 and Figure 2 As shown, the method includes:

[0047] S110 provides a composite substrate.

[0048] For details, please refer to Figure 2As shown in Figure a), the composite substrate includes a substrate 10 and a heterolayer 20 located on one side of the substrate 10. The substrate 10 is a smoothed and polished substrate with a flat surface, meaning that the substrate 10 has a high-quality C-plane, which helps the epitaxial crystal to form a nucleus and grow into the heterolayer 20. The material of the substrate 10 may include, but is not limited to, sapphire substrates, etc. During the preparation process, an SMP solution (a mixture of sulfuric acid (H2SO4) solution and hydrogen peroxide (H2O2) solution) is used to clean the surface of the substrate 10 to remove metal impurities; then, the heterolayer 20 is formed on one side of the substrate 10 by chemical vapor deposition or other methods. The heterolayer 20 is made of a heterogeneous material, which is essentially a material different from the substrate 10 and the epitaxial layer material, such as gallium nitride.

[0049] S120. A photoresist layer is formed on the surface of the composite substrate, and the photoresist layer is patterned to form a photoresist pillar mask.

[0050] For details, please refer to Figure 2 As shown in Figure b), a photoresist layer is formed on the surface of the heterolayer 20, and the photoresist layer is patterned using a pattern transfer technique to form a photoresist pillar mask 30. Exemplarily, the pattern transfer technique can be photolithography or nanoimprint lithography, etc. The photoresist pillar mask 30 is a pattern mask for patterning the photoresist layer, and it serves as a sacrificial layer for subsequent tilt etching of the heterolayer 20 and the substrate 10.

[0051] S130. Using the first etching process, at least a first etching gas is introduced into the reaction chamber of the first etching process to adjust the etching rate of the heterolayer and the photoresist mask, so that the tilt angle of the heterolayer is at a first preset angle α1.

[0052] The dry etching process includes a first etching process and a second etching process. The dry etching process can be an inductively coupled plasma (ICP) process, but is not limited to this. The principle of dry etching can be roughly described as follows: Plasma, after gas dissociation, bombards the material surface, causing physical and / or chemical changes, thereby removing part of the material and achieving the etching purpose. The etching gases introduced into both the first and second etching processes include at least the first etching gas. A second etching gas may also be introduced depending on the situation. The first etching gas plays the main etching role, while the second gas plays a role in fine-tuning the etching rate.

[0053] For details, please refer to Figure 2Figure c) shows that during the etching process, a first etching process is used, and a first etching gas of a certain flow rate is introduced into the reaction chamber of the first etching process. A certain amount of radio frequency power is applied to the reaction chamber. Under these conditions, by adjusting the flow rate of the first etching gas, a chemical or physical reaction occurs between the first etching gas and the heterolayer 20 and the adhesive pillar mask 30, so as to adjust the etching rate of the heterolayer 20 and the adhesive pillar mask 30. After the reaction time reaches the predetermined time, the tilt angle of the heterolayer 20 can be made to reach the first preset angle α1.

[0054] S140. Using a second etching process, at least a first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist pillar mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1.

[0055] Where α4 < α1, the tilt angle of substrate 10 is the angle between the plane containing the bottom surface of substrate 10 and the plane containing the sidewall of substrate 10, and the tilt angle of heterolayer 20 is the angle between the plane containing the bottom surface of heterolayer 20 and the plane containing the sidewall of heterolayer 20, and the angle is acute.

[0056] For details, please refer to Figure 2 As shown in Figure d), after the first etching process is completed, a second etching process is used, and a certain flow rate of the first etching gas is introduced into the reaction chamber of the second etching process. A certain amount of radio frequency power is applied to the reaction chamber. Under these conditions, by adjusting the flow rate of the first etching gas, a chemical or physical reaction occurs between the first etching gas and the substrate 10, the heterolayer 20, and the adhesive pillar mask 30, so as to adjust the etching rate of the substrate 10, the heterolayer 20, and the adhesive pillar mask 30. After the reaction time reaches the predetermined time, the adhesive pillar mask 30 is completely removed. At this time, the tilt angle of the heterolayer 20 is at the first target angle α4, and the tilt angle of the substrate 10 is at the second target angle β1.

[0057] It should be noted that the process of introducing at least the first etching gas into the reaction chamber of the second etching process in this step is essentially changing the flow rate of the first etching gas from the previous step. This increases or decreases the flow rate of the first etching gas, thereby increasing or decreasing the concentration of the plasma gas source, and achieving the removal of the photoresist mask 30 so that the substrate 10 is at the second target angle β1 and the heterolayer 20 is at the first target angle α4. Instead of transferring the composite substrate to another reaction chamber and re-introducing the gas, this method avoids the generation of impurities and other substances during the intermediate transfer process by keeping the reaction chamber unchanged and only changing the chamber conditions.

[0058] It should also be noted that, for the heterolayer 20, the first target angle α4 obtained after the second etching process is less than the first preset angle α1, that is, α4 < α1. In other words, after the second etching process, the bottom of the heterolayer 20 is widened and the etching rate of the area of ​​the heterolayer 20 away from the substrate 10 is increased, so that the heterolayer 20 finally presents a structure that is narrow at the top and wide at the bottom.

[0059] It should be noted that when both the tilt angle of the substrate 10 and the tilt angle of the heterolayer 20 reach the preset target angles, there may be a certain relationship between the first target angle α4 and the second target angle β1. For example, the first target angle α4 may be greater than the second target angle β1, the first target angle α4 may be less than the second target angle β1, or the first target angle α4 may be equal to the second target angle β1. The actual final result can be determined according to the actual situation, and no restrictions are imposed here. Figure 2 The d-plot only shows the case where the first target angle α4 and the second target angle β1 are equal, as an example only.

[0060] The technical solution of this invention utilizes a first etching process, by introducing at least a first etching gas into the reaction chamber of the first etching process, to adjust the etching rate of the heterolayer and the photoresist pillar mask, so that the tilt angle of the heterolayer is at a first preset angle; and utilizes a second etching process, by introducing at least a first etching gas into the reaction chamber of the second etching process, to remove the photoresist pillar mask, and to make the tilt angle of the heterolayer at a first target angle, and the tilt angle of the substrate at a second target angle; the first target angle is less than the first preset angle. Using the above method, through the main second etching process, precise control of the tilt angle of the heterolayer and the substrate is achieved at each stage, ensuring the accuracy of the final target tilt angle of the heterolayer and the substrate, and completing a high-fidelity transfer of the tilt angle of the heterolayer and the substrate in the composite structure substrate, providing flexible options for different application scenarios of the composite patterned structure.

[0061] In another specific embodiment, Figure 3 This is a flowchart of another method for controlling the tilt angle of a composite patterned substrate provided in an embodiment of the present invention. Figure 4 for Figure 3 The fabrication process diagram of the corresponding tilt angle control method for composite patterned substrates. Figure 5 for Figure 4 The schematic diagram of parameter changes during the corresponding fabrication process is shown in this embodiment. In the above embodiment, S130, utilizing the first etching process, involves introducing at least a first etching gas into the reaction chamber of the first etching process to adjust the etching rate of the heterolayer and the photoresist mask, so that the tilt angle of the heterolayer is at a first preset angle α1. The specific implementation of this is further refined as follows:

[0062] By introducing a first etching gas and a second etching gas at preset flow rates into the reaction chamber of the first etching process, a passivation layer is formed on the sidewall of the heterolayer under the first preset conditions. The etching rates of the adhesive column mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is at a second preset angle α2.

[0063] Stop the supply of the second etching gas, and under the second preset conditions, reduce the etching rate at the top of the adhesive column mask and the longitudinal etching rate of the heterolayer, so that the tilt angle of the heterolayer is at the third preset angle α3.

[0064] While maintaining the cessation of the second etching gas supply, under the third preset condition, the lateral etching rate of the heterolayer is increased so that the tilt angle of the heterolayer is at the first preset angle α1; α2=α3>α1.

[0065] Furthermore, the specific implementation of S140, using the second etching process, by introducing at least the first etching gas into the reaction chamber of the second etching process to remove the photoresist pillar mask, and making the tilt angle of the heterolayer reach the first target angle α4, and the tilt angle of the substrate reach the second target angle β1, is refined as follows:

[0066] By introducing a first etching gas with a preset flow rate into the reaction chamber of the second etching process, under the fourth preset conditions, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is at the first target angle α4, and the tilt angle of the substrate is at the second target angle β1; α4=β1.

[0067] For details not covered in this embodiment, please refer to the above embodiments, which will not be repeated here.

[0068] refer to Figures 3 to 5 As shown, the method includes:

[0069] S310 provides a composite substrate.

[0070] refer to Figure 4 Figure a).

[0071] S320. A photoresist layer is formed on the surface of the composite substrate, and the photoresist layer is patterned to form a photoresist pillar mask.

[0072] refer to Figure 4 Figure b).

[0073] S330. By introducing a first etching gas and a second etching gas at preset flow rates into the reaction chamber of the first etching process, a passivation layer is formed on the sidewall of the heterolayer under the first preset conditions. The etching rates of the adhesive column mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is at a second preset angle α2.

[0074] For details, please refer to Figure 4Figure c) shows that in the first etching stage, a first etching gas and a second etching gas with preset flow rates are introduced into the reaction chamber of the first etching process. The first etching gas may include, but is not limited to, boron trichloride (BCl3) or a mixture of boron trichloride and chlorine (BCl3 / Cl2). The second etching gas may include, but is not limited to, nitrogen. The selection of the first and second etching gases is related to the materials of the heterolayer 20 and the substrate 10, and can be determined according to the actual situation, without limitation here. When the first and second etching gases are introduced simultaneously, the two gases will ionize, generating positive and negative ions. The generated ions will react to form a passivation layer covering the surface of the heterolayer 20 and the adhesive pillar mask 30. Specifically, the ionization process of boron trichloride gas will produce a three-stage ionization reaction, namely ① , ② ③ The second etching gas ionizes to produce a second-order ionization reaction, namely... The plasma source formed at this time includes , , , , , and ,in, and A chemical reaction occurs, generating solid byproducts that adhere to the sidewalls of heterostructure 20 and colloidal pillar mask 30, forming a boron nitride passivation layer. This process can promote the occurrence of the third-stage ionization process, which in turn promotes the occurrence of the first-stage and second-stage ionization processes, making... , , Increased concentration improves the etching rate of the gel pillar mask 30 and the heterolayer 20. Simultaneously, It can form a volatile compound with the oxygen element in the photoresist. Gases cause a decrease in the etching resistance of the mask layer, i.e. Furthermore, when the passivation layer is attached to the surfaces of the heterolayer 20 and the resin pillar mask 30, the etching resistance of the heterolayer 20 and the resin pillar mask 30 is improved, resulting in a slowdown in the lateral etching rate of the heterolayer 20. In contrast, the longitudinal etching rate increases, meaning that the lateral etching rate is less than the longitudinal etching rate. This achieves the adjustment of the etching rate of the heterolayer 20 and the resin pillar mask 30, reducing the ratio of the lateral etching rate to the longitudinal etching rate in the etching process from 0.5-0.7 to 0.2-0.4. Ultimately, this results in the tilt angle of the heterolayer 20 forming the second preset angle α2.

[0075] It should be noted that the reference Figure 5In this process, it is necessary to control the first preset conditions in the first etching process, namely the flow rates of the first and second etching gases, and the magnitude of the radio frequency power, so that the tilt angle of the heterolayer 20 is at the second preset angle α2. In this embodiment, the first preset conditions include an upper radio frequency power range of 1000W-1500W, a lower radio frequency power range of 700W-900W, a reaction time of 200s-300s, a preset flow rate of the first etching gas of 90sccm-120sccm, and a flow rate of the second etching gas of 10sccm-25sccm. The upper radio frequency power range is 1000W-1500W. For example, the upper radio frequency power can be 1000W, 1100W, 1200W, 1300W, 1400W, or 1500W, which can be determined according to the actual situation and is not limited here. The lower RF power range is 700W-900W. For example, the lower RF power can be 700W, 750W, 800W, 850W, or 900W, and can be determined according to actual conditions. No limitation is imposed here. The reaction time is 200s-300s. For example, the reaction time can be 200s, 220s, 260s, 280s, or 300s, and can be determined according to actual conditions. No limitation is imposed here. The preset flow rate of the first etching gas is 90sccm-120sccm. For example, the preset flow rate of the first etching gas can be 90sccm, 100sccm, 110sccm, or 120sccm, and can be determined according to actual conditions. No limitation is imposed here. The flow rate of the second etching gas is 10sccm-25sccm. For example, the preset flow rate of the second etching gas can be 10sccm, 15sccm, 20sccm, or 25sccm, and can be determined according to actual conditions. No limitation is imposed here. It can be seen that introducing a small amount of second etching gas simultaneously with the first etching gas not only improves the selectivity but also increases the etching rate and reduces the process time. By reasonably controlling the ratio of the first etching gas to the auxiliary etching gas, on the one hand, the selectivity can be increased to improve the height; on the other hand, the sidewall morphology of the heterolayer 20 and the photoresist pillar mask 30 can be controlled, and the bottom width of the heterolayer 20 can be gradually increased so that the tilt angle of the heterolayer 20 is at the second preset angle α2.

[0076] S340. Stop the supply of the second etching gas. Under the second preset conditions, reduce the etching rate at the top of the adhesive column mask and the longitudinal etching rate of the heterolayer, so that the tilt angle of the heterolayer is at the third preset angle α3.

[0077] For details, please refer to Figure 4Figure d) shows that in the second etching stage, the second etching gas is stopped, and only the first etching gas is supplied. Under the second preset conditions, the concentration of the second etching gas decreases, resulting in a reduction in the positive ions generated by the ionization of the second etching gas and a decrease in the reaction with the negative ions generated by the ionization of the first etching gas. Consequently, the solid passivation layer is reduced, causing the passivation layers on the sidewalls of the heterolayer 20 and the adhesive pillar mask 30 to become thinner or partially detach. The plasma gas source formed at this time includes particles including , , , and Simultaneously, under the same RF power, the ion bombardment energy decreases, making it difficult to break through the resin pillar mask 30 layer and the passivation layer on the sidewalls of the heterolayer 20. This reduces the reaction rate on the surface of the heterolayer 20, resulting in a decrease in the vertical etching rate of the heterolayer 20 and improving edge protection at the top of the heterolayer 20. Furthermore, for the resin pillar mask 30, its consumption is mainly due to free ion attack. High-energy ion bombardment exacerbates the reaction rate. In this step, the concentration of free ions and the ion bombardment intensity are reduced, thus decreasing the rate at which the resin pillar mask 30 is chemically etched. Simultaneously, the vertical bombardment is reduced, thereby slowing down the shrinkage of the resin pillar mask 30 and preserving the top width of the resin pillar mask 30 as much as possible to achieve high-fidelity pattern transfer.

[0078] Furthermore, the reduced formation of the passivation layer weakens its protection of the sidewalls of the heterolayer 20 and the resin pillar mask 30, resulting in a slight increase in the lateral etching rate of the heterolayer 20. However, the overall etching rate remains dominated by the longitudinal etching rate. This causes the sidewalls of the heterolayer 20 and the resin pillar mask 30 to extend downwards, resulting in the tilt angle of the heterolayer 20 being a third preset angle α3. It should be noted that the third preset angle α3 is the same as the second preset angle α2, i.e., α2=α3. In other words, the tilt angle of the heterolayer 20 continues downwards from the second preset angle α2 formed in the first etching stage, ensuring that the tilt angle of the heterolayer 20 remains unchanged.

[0079] It should be noted that the reference Figure 5The etching conditions set during the second etching stage are the second preset conditions, namely, an upper RF power range of 1000W-1500W, a lower RF power range of 700W-900W, and a response time of 350s-600s. The upper RF power range of 1000W-1500W can be exemplarily 1000W, 1100W, 1200W, 1300W, 1400W, or 1500W, and can be determined according to actual conditions without limitation. The lower RF power range of 700W-900W can be exemplarily 700W, 750W, 800W, 850W, or 900W, and can be determined according to actual conditions without limitation. The reaction time is 350s-600s. For example, the reaction time can be 350s, 400s, 450s, 500s, 550s, or 600s, and the specific time can be determined according to the actual situation. No limitation is imposed here. Additionally, the preset flow rate of the first etching gas is 90sccm-120sccm. For example, the preset flow rate of the first etching gas can be 90sccm, 100sccm, 110sccm, or 120sccm, and the specific flow rate can be determined according to the actual situation. No limitation is imposed here.

[0080] S350, Maintain the stop of the second etching gas supply, and under the third preset condition, increase the lateral etching rate of the heterolayer so that the tilt angle of the heterolayer is at the first preset angle α1.

[0081] For details, please refer to Figure 4Figure e) shows that in the third etching stage, the second etching gas is stopped and only the first etching gas is supplied. Under the third preset conditions, the upper radio frequency power range is 1000W-1500W, the lower radio frequency power range is 200W-350W, and the reaction time is 200s-300s. It can be seen that compared with the second etching stage, the lower radio frequency power is reduced in this stage, and it is under low radio frequency power conditions. The purpose of this setting is to increase the lateral etching rate of the heterolayer 20 and promote lateral expansion. Specifically, stopping the flow of the second etching gas reduces the positive ions generated by the ionization of the second etching gas, thereby reducing the amount of material needed to form the passivation layer, making the passivation layer thinner. At the same time, reducing the lower radio frequency power, such as from 600W to 350W-450W, reduces the ion bombardment energy, making the passivation layer on the sidewall of the heterolayer 20 less susceptible to damage, thus forming temporary protection. The longitudinal etching rate of the heterolayer 20 weakens, while the lateral etching rate relatively increases. In other words, the longitudinal etching rate of the heterolayer 20 decreases significantly, and the lateral etching rate also decreases, but at a slower rate than the longitudinal etching rate. Therefore, the lateral etching rate increases relative to the longitudinal etching rate, resulting in a slight increase in the ratio of the lateral to longitudinal etching rates, which in turn promotes the lateral etching rate of the heterolayer 20. Ultimately, this makes the sidewall of the heterolayer 20 more inclined, with the tilt angle of the heterolayer 20 being a first preset angle α1. It can be seen that the first preset angle α1 is less than the third preset angle α3.

[0082] Experimental results show that the bottom width of heterolayer 20 expands to 2.42 μm under 350W-450W power and to 2.34 μm under 600W power. It can be seen that the bottom width is larger under lower power and smaller under higher power. This is because the vertical etching rate is lower at lower power, while the lateral etching is relatively more active, allowing more time for sidewall etching. As etching progresses, the lateral etching amount of each layer gradually accumulates, resulting in a larger bottom width at lower power, forming a trapezoidal profile that is narrower at the top and wider at the bottom. Furthermore, the reduced vertical etching rate slows down the vertical etching process, thus extending the process time. This process accounts for 30%-50% of the total etching time, achieving long-term adaptability.

[0083] It should be noted that the reference Figure 5The third preset condition is that the upper RF power range is 1000W-1500W, the lower RF power range is 200W-350W, and the response time is 200s-300s. Specifically, the upper RF power range of 1000W-1500W can be, for example, 1000W, 1100W, 1200W, 1300W, 1400W, or 1500W, and can be determined according to actual conditions without limitation. The lower RF power range of 200W-350W can be, for example, 200W, 250W, 300W, or 350W, and can be determined according to actual conditions without limitation. The response time of 200s-300s can be, for example, 200s, 250s, 280s, or 300s, and can be determined according to actual conditions without limitation. In addition, the preset flow rate of the first etching gas is 90 sccm-120 sccm. For example, the preset flow rate of the first etching gas can be 90 sccm, 100 sccm, 110 sccm or 120 sccm. The specific flow rate can be determined according to the actual situation and is not limited here.

[0084] S360. By introducing a first etching gas with a preset flow rate into the reaction chamber of the second etching process, under the fourth preset conditions, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is at the first target angle α4, and the tilt angle of the substrate is at the second target angle β1.

[0085] Where α4 = β1.

[0086] For details, please refer to Figure 4Figure f) shows that in the fourth etching stage, the second etching gas is stopped from being introduced into the reaction chamber, and only the first etching gas with a preset flow rate is introduced. Under the fourth preset conditions, the upper RF power range is 1000W-1500W and the lower RF power range is 400W-700W. It can be seen that compared with the second and third preset conditions, the lower RF power in this step is between the two, that is, the lower RF power is in the lower-middle RF power condition. Under this condition, the flow rate of the first etching gas is reduced, which reduces the density of negative ions generated by the ionization of the first etching gas, and thus reduces the concentration of the plasma gas source. The etching process becomes mild, slow and controllable, and the remaining adhesive pillar mask 30 can be etched, thereby removing the adhesive pillar mask 30 and etching into the interface region between the heterolayer 20 and the substrate 10. Furthermore, at medium to low RF power, the ion bombardment energy is enhanced compared to the fourth etching stage, which helps reduce the etching rate difference between the heterolayer 20 and the substrate 10. Based on the etching resistance, the etching rates between the heterolayer 20 and the substrate 10 are made similar, avoiding phenomena such as steps, drilling, or reflections at the interface between the heterolayer 20 and the substrate 10. The heterolayer 20 and the substrate 10 can be treated as the same material for etching, ensuring a relatively smooth transition of the sidewalls of the heterolayer 20 and the substrate 10. This achieves a high-fidelity transfer of the tilt angle of the heterolayer 20 to the substrate 10, and the tilt angle of the heterolayer 20 formed at this time is the first target angle. The substrate 10 is tilted at the second target angle. The first target angle is equal to the second target angle, i.e., α4 = β1. Furthermore, the sidewall curvature of the heterolayer 20 in the final patterned composite substrate is relatively low, and the arc height of the heterolayer 20 is greater than 50% of the pattern arc height, which improves the longitudinal light extraction efficiency.

[0087] It should be noted that continued reference is necessary. Figure 5 The fourth preset condition is that the upper RF power range is 1000W-1500W, and the lower RF power range is 400W-700W. Specifically, the upper RF power range of 1000W-1500W can be, for example, 1000W, 1100W, 1200W, 1300W, 1400W, or 1500W, and can be determined according to actual conditions, without limitation here. The lower RF power range of 400W-700W can be, for example, 400W, 450W, 500W, 550W, 600W, or 700W, and can be determined according to actual conditions, without limitation here. In addition, the preset flow rate of the first etching gas is 90 sccm-120 sccm. For example, the preset flow rate of the first etching gas can be 90 sccm, 100 sccm, 110 sccm or 120 sccm. The specific flow rate can be determined according to the actual situation and is not limited here.

[0088] The technical solution of this invention involves introducing a first etching gas and a second etching gas at preset flow rates into the reaction chamber of the first etching process. Under a first preset condition, a passivation layer is formed on the sidewall of the heterolayer. The etching rates of the photoresist mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is a second preset angle. The second etching gas is then stopped. Under the second preset condition, the etching rate at the top of the photoresist mask and the longitudinal etching rate of the heterolayer are reduced so that the tilt angle of the heterolayer is a third preset angle. The second etching gas is then stopped. Under the third preset condition, the lateral etching rate of the heterolayer is increased so that the tilt angle of the heterolayer is a first preset angle. The first etching gas at a preset flow rate is then introduced into the reaction chamber of the second etching process. Under a fourth preset condition, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced so that the tilt angle of the heterolayer is a first target angle, and the tilt angle of the substrate is a second target angle. The first target angle and the second target angle are equal. Using the above method, the bottom and height expansion efficiency of the heterolayer was improved, and high-fidelity transfer of the heterolayer to the substrate was achieved, which improved the patterning transfer efficiency by 10%-15% and improved the longitudinal light extraction efficiency.

[0089] In another specific embodiment, Figure 6 This is a flowchart of another method for controlling the tilt angle of a composite patterned substrate provided in an embodiment of the present invention. Figure 7 for Figure 6 The fabrication process diagram of the corresponding tilt angle control method for composite patterned substrates. Figure 8 for Figure 7 The schematic diagram of parameter changes during the corresponding fabrication process is shown in this embodiment. In the above embodiment, S130, utilizing the first etching process, involves introducing at least a first etching gas into the reaction chamber of the first etching process to adjust the etching rate of the heterolayer and the photoresist mask, so that the tilt angle of the heterolayer is at a first preset angle α1. The specific implementation of this is further refined as follows:

[0090] By introducing a first etching gas and a second etching gas at preset flow rates into the reaction chamber of the first etching process, a passivation layer is formed on the sidewall of the heterolayer under the first preset conditions. The etching rates of the adhesive column mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is at a second preset angle α2.

[0091] Stop the supply of the second etching gas, and under the second preset conditions, reduce the etching rate at the top of the adhesive column mask and the longitudinal etching rate of the heterolayer, so that the tilt angle of the heterolayer is at the third preset angle α3.

[0092] While maintaining the cessation of the second etching gas supply, under the third preset condition, the lateral etching rate of the heterolayer is increased so that the tilt angle of the heterolayer is at the first preset angle α1; α2=α3>α1.

[0093] Furthermore, the specific implementation of S140, using the second etching process, by introducing at least the first etching gas into the reaction chamber of the second etching process to remove the photoresist pillar mask, and making the tilt angle of the heterolayer reach the first target angle α4, and the tilt angle of the substrate reach the second target angle β1, is refined as follows:

[0094] By introducing a first etching gas with a preset flow rate into the reaction chamber of the second etching process, under the fourth preset conditions, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is the fourth preset angle α5 and the tilt angle of the substrate is the fifth preset angle β2.

[0095] A first etching gas and a second etching gas with a preset flow rate are introduced into the reaction chamber of the second etching process. Under the fifth preset condition, the bottom tilt angle of the substrate is reduced so that the tilt angle of the heterolayer is at the first target angle α4 and the tilt angle of the substrate is at the second target angle β1; α4=α5=β2>β1.

[0096] For details not covered in this embodiment, please refer to the above embodiments, which will not be repeated here.

[0097] refer to Figures 6 to 8 As shown, the method includes:

[0098] S410 provides a composite substrate.

[0099] refer to Figure 7 Figure a).

[0100] S420. A photoresist layer is formed on the surface of the composite substrate, and the photoresist layer is patterned to form a photoresist pillar mask.

[0101] refer to Figure 7 Figure b).

[0102] S430. By introducing a first etching gas and a second etching gas at preset flow rates into the reaction chamber of the first etching process, a passivation layer is formed on the sidewall of the heterolayer under the first preset conditions. The etching rates of the adhesive column mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is at a second preset angle α2.

[0103] For details, please refer to Figure 7 Figure c)

[0104] S440. Stop the supply of the second etching gas. Under the second preset conditions, reduce the etching rate at the top of the adhesive column mask and the longitudinal etching rate of the heterolayer, so that the tilt angle of the heterolayer is at the third preset angle α3.

[0105] For details, please refer to Figure 7 d) of the figure.

[0106] S450, Maintain the stop of the second etching gas supply, and under the third preset condition, increase the lateral etching rate of the heterolayer so that the tilt angle of the heterolayer is at the first preset angle α1.

[0107] For details, please refer to Figure 7 Figure e).

[0108] S460. By introducing a first etching gas with a preset flow rate into the reaction chamber of the second etching process, under the fourth preset conditions, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is a fourth preset angle α5, and the tilt angle of the substrate is a fifth preset angle β2.

[0109] For details, please refer to Figure 7 The f) diagram. It is understood that this step is essentially the same as S360, and will not be repeated here. The final fourth preset angle α5 is equal to the fifth preset angle β2.

[0110] S470. Introduce a first etching gas and a second etching gas at preset flow rates into the reaction chamber of the second etching process. Under the fifth preset condition, reduce the bottom tilt angle of the substrate so that the tilt angle of the heterolayer is at the first target angle α4 and the tilt angle of the substrate is at the second target angle β1.

[0111] Among them, α4=α5=β2>β1.

[0112] For details, please refer to Figure 7 As shown in Figure g), in the fifth etching stage, a second etching gas can be introduced into the reaction chamber of the etching process based on the fourth etching stage. Under the fifth preset conditions, the positive ions ionized by the second etching gas and the negative ions ionized by the first etching gas combine to form a passivation layer covering the sidewall surface and top of the heterolayer 20, protecting the sidewall and top of the heterolayer 20, increasing the etching resistance of the heterolayer 20, and making the etching rate extremely low, so that the overall outline of the sidewall of the heterolayer 20 is basically "frozen", that is, the tilt angle of the heterolayer 20 does not change significantly, and the first target angle α4 is equal to the fourth preset angle α5. Simultaneously, the sidewalls of substrate 10 are also covered with a passivation layer. However, due to the varying stability of the passivation layer on different surfaces, the bombardment energy of the free plasma source is low when bombarding the sidewalls due to the tilted angle, making it difficult to completely remove the passivation layer. This results in anisotropic modification etching, suppressing the lateral expansion of substrate 10. The bottom, however, is bombarded vertically by the plasma source with higher energy, causing the passivation layer of substrate 10 to be rapidly sputtered away, extending downwards and reducing the tilt angle of the bottom of substrate 10. This brings the tilt angle of substrate 10 to the second target angle β1, achieving a "fine-tuning" of the bottom of substrate 10, making it more vertical and beneficial for subsequent filling, stress relief, or electrical performance optimization. The second target angle β1 is smaller than the first target angle α4.

[0113] It should be noted that the reference Figure 8 The fifth preset condition is that the upper RF power range is 1000W-1500W, the lower RF power range is 400W-700W, the preset flow rate of the first etching gas is 90sccm-120sccm, and the flow rate of the second etching gas is 10sccm-25sccm. Specifically, the upper RF power range of 1000W-1500W can be, for example, 1000W, 1100W, 1200W, 1300W, 1400W, or 1500W, and can be determined according to actual conditions without limitation. The lower RF power range of 400W-700W can be, for example, 400W, 450W, 500W, 600W, or 700W, and can be determined according to actual conditions without limitation. The preset flow rate of the first etching gas is 90 sccm-120 sccm. For example, the preset flow rate of the first etching gas can be 90 sccm, 100 sccm, 110 sccm, or 120 sccm, and can be determined according to the actual situation; no restriction is placed here. However, it must be ensured that the flow rate of the first etching gas in this stage is less than the flow rate of the first etching gas introduced in the first to third etching stages. The flow rate of the second etching gas is 10 sccm-25 sccm. For example, the preset flow rate of the second etching gas can be 10 sccm, 15 sccm, 20 sccm, or 25 sccm, and can be determined according to the actual situation; no restriction is placed here. However, it must be ensured that the flow rate of the second etching gas in this stage is greater than the flow rate of the second etching gas introduced in the first etching stage.

[0114] The technical solution of this invention involves introducing a first etching gas at a predetermined flow rate into the reaction chamber of the second etching process. Under a fourth predetermined condition, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, resulting in a fourth predetermined angle for the heterolayer and a fifth predetermined angle for the substrate. Then, a first etching gas and a second etching gas at predetermined flow rates are introduced into the reaction chamber of the second etching process. Under the fifth predetermined condition, the bottom tilt angle of the substrate is reduced, resulting in a first target angle for the heterolayer and a second target angle for the substrate. The first target angle, the fourth predetermined angle, and the fifth predetermined angle are all equal and greater than the second target angle. Using this method, the tilt angle of the heterolayer is greater than the tilt angle of the substrate, increasing the substrate step height, reducing the risk of heterolayer anomalies, improving lattice fit, and effectively reducing fogging anomalies in the epitaxial process.

[0115] In another specific embodiment, Figure 9 This is a flowchart of another method for controlling the tilt angle of a composite patterned substrate provided in an embodiment of the present invention. Figure 10 for Figure 9The fabrication process diagram of the corresponding tilt angle control method for composite patterned substrates. Figure 11 for Figure 10 The schematic diagram of parameter changes during the corresponding fabrication process is shown in this embodiment. In the above embodiment, S130, utilizing the first etching process, involves introducing at least a first etching gas into the reaction chamber of the first etching process to adjust the etching rate of the heterolayer and the photoresist mask, so that the tilt angle of the heterolayer is at a first preset angle α1. The specific implementation of this is further refined as follows:

[0116] By introducing a first etching gas with a preset flow rate into the reaction chamber of the first etching process, and under the sixth preset condition, the etching rate of the photoresist mask and the heterolayer is adjusted so that the tilt angle of the heterolayer is at the sixth preset angle α6.

[0117] Under the seventh preset condition, the etching rate at the top of the adhesive pillar mask and the longitudinal etching rate of the heterolayer are reduced, so that the tilt angle of the heterolayer is at the first preset angle α1; α1 < α6;

[0118] Furthermore, the specific implementation of S140, using the second etching process, by introducing at least the first etching gas into the reaction chamber of the second etching process to remove the photoresist pillar mask, and making the tilt angle of the heterolayer reach the first target angle α4, and the tilt angle of the substrate reach the second target angle β1, is refined as follows:

[0119] Increase the flow rate of the first etching gas, and under the eighth preset condition, remove the photoresist pillar mask to increase the etching rate difference between the substrate and the heterolayer, so that the tilt angle of the heterolayer is at the first target angle α4 and the tilt angle of the substrate is at the second target angle β1; α4 < β1.

[0120] For details not covered in this embodiment, please refer to the above embodiments, which will not be repeated here.

[0121] refer to Figures 9 to 11 As shown, the method includes:

[0122] S510 provides composite substrates.

[0123] refer to Figure 10 Figure a).

[0124] S520. A photoresist layer is formed on the surface of the composite substrate, and the photoresist layer is patterned to form a photoresist pillar mask.

[0125] refer to Figure 10 Figure b).

[0126] S530. By introducing a first etching gas with a preset flow rate into the reaction chamber of the first etching process, under the sixth preset condition, the etching rate of the photoresist mask and the heterolayer is adjusted so that the tilt angle of the heterolayer is at the sixth preset angle α6.

[0127] For details, please refer to Figure 10 In Figure c), during the first etching stage, only the first etching gas is introduced. Under the sixth preset condition, the lower-frequency power range is 400W-700W, which is considered a lower-frequency power range. At this time, only the first etching gas undergoes ionization, generating negative ions. The plasma gas source at this time includes... , , , and Therefore, no passivation layer is generated on the sidewalls of the heterostructure 20 and the resin pillar mask 30, so that the sidewalls of the resin pillar mask 30 and the heterostructure 20 are exposed to the plasma. Under medium and low radio frequency power conditions, the ion bombardment energy is high, and the unprotected resin pillar mask 30 and the heterostructure 20 are etched, which promotes the rapid etching of the resin pillar mask 30 and the heterostructure 20 in the longitudinal direction and improves the longitudinal etching rate. After etching, the tilt angle of the heterostructure 20 is the sixth preset angle α6.

[0128] It should be noted that the reference Figure 11 The etching conditions set during the first etching stage are the sixth preset conditions, namely, an upper RF power range of 1000W-1500W, a lower RF power range of 400W-700W, and a response time of 200s-300s. The upper RF power range of 1000W-1500W can be exemplarily 1000W, 1100W, 1200W, 1300W, 1400W, or 1500W, and can be determined according to actual conditions without limitation. The lower RF power range of 400W-700W can be exemplarily 400W, 450W, 500W, 600W, or 700W, and can be determined according to actual conditions without limitation. The reaction time is 200s-300s. For example, the reaction time can be 200s, 250s, 280s, or 300s, and the specific time can be determined according to the actual situation. No limitation is imposed here. Additionally, the preset flow rate of the first etching gas is 90sccm-120sccm. For example, the preset flow rate of the first etching gas can be 90sccm, 100sccm, 110sccm, or 120sccm, and the specific flow rate can be determined according to the actual situation. No limitation is imposed here.

[0129] S540. Under the seventh preset condition, reduce the etching rate at the top of the adhesive pillar mask and the longitudinal etching rate of the heterolayer, so that the tilt angle of the heterolayer is at the first preset angle α1.

[0130] Among them, the first preset angle α1 is less than the sixth preset angle α6;

[0131] For details, please refer to Figure 10As shown in Figure d), in the second etching stage, the first etching gas flow rate remains constant. Under the seventh preset condition, the RF power range is 200W-350W, which is a low RF power condition. Under this condition, the ion bombardment energy decreases, the overall plasma activity weakens, and the vertical physical sputtering on the resin pillar mask 30 and the heterolayer 20 is reduced, thus slowing down the shrinkage of the resin pillar mask 30. The top width of the resin pillar mask 30 is maintained as much as possible to achieve high-fidelity pattern transfer. Furthermore, the top structure of the resin pillar mask 30 is stable under low power, continuing to shield the top of the heterolayer 20. Therefore, etching mainly occurs in the central region of the exposed heterolayer 20, achieving edge protection of the top of the heterolayer 20. After a long period of low-power etching, the sidewalls of the heterolayer 20 continue to extend downwards, but the tilt angle becomes slightly gentler, forming a first preset angle α1. The first preset angle α1 is smaller than the sixth preset angle α6.

[0132] It should be noted that the reference Figure 11 The etching conditions set during the second etching stage are the seventh preset conditions, namely, an upper RF power range of 1000W-1500W, a lower RF power range of 200W-350W, and a response time of 350s-600s. The upper RF power range of 1000W-1500W can be exemplarily 1000W, 1100W, 1200W, 1300W, 1400W, or 1500W, and can be determined according to actual conditions without limitation. The lower RF power range of 200W-350W can be exemplarily 200W, 250W, 300W, or 350W, and can be determined according to actual conditions without limitation. The reaction time is 350s-600s. For example, the reaction time can be 350s, 400s, 450s, 500s, 550s, or 600s, and the specific time can be determined according to the actual situation. No limitation is imposed here. Additionally, the preset flow rate of the first etching gas is 90sccm-120sccm. For example, the preset flow rate of the first etching gas can be 90sccm, 100sccm, 110sccm, or 120sccm, and the specific flow rate can be determined according to the actual situation. No limitation is imposed here.

[0133] S550. Increase the flow rate of the first etching gas, remove the photoresist pillar mask under the eighth preset condition, and increase the etching rate difference between the substrate and the heterolayer, so that the tilt angle of the heterolayer is the first target angle α4 and the tilt angle of the substrate is the second target angle β1.

[0134] Among them, the first target angle α4 is smaller than the second target angle β1.

[0135] For details, please refer to Figure 10As shown in Figure e), in the third etching stage, by increasing the flow rate of the first etching gas, under the eighth preset condition (where the upper RF power range is 1000W-1500W and the lower RF power range is 700W-900W), a high RF power condition is achieved. Under this condition, the increased flow rate of the first etching gas leads to an increased concentration of negative ions generated by the ionization of the first etching gas, i.e., an increased plasma gas source concentration, resulting in a high etching rate. This facilitates rapid penetration of the adhesive pillar mask 30 to remove the adhesive pillar mask 30 and etch into the interface between the heterolayer 20 and the substrate 10. Furthermore, a high etching rate helps to widen the etching rate difference between the heterolayer 20 and the substrate 10, leading to a differential transfer of the tilt angle of the heterolayer 20 towards the substrate 10. This increases the etching rate of the sidewalls of the heterolayer 20. While vertical etching can extend rapidly downwards, lateral etching, being faster, gradually accumulates, causing the sidewalls of the heterolayer 20 to expand further outwards. Therefore, the first target angle α4 formed by the heterolayer 20 is smaller than the first preset angle α1. In addition, due to the etching resistance of the substrate 10, the etching rate of the substrate 10 is slower, and the etching mainly occurs in the central region of the bottom of the substrate 10. Therefore, the sidewalls of the substrate 10 will be straighter, ultimately forming the second target angle β1. It can be seen that the second target angle β1 is greater than the first target angle α4.

[0136] The technical solution of this invention involves introducing a first etching gas at a predetermined flow rate into the reaction chamber of the first etching process. Under a sixth predetermined condition, the etching rates of the photoresist pillar mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is at a sixth predetermined angle. Under a seventh predetermined condition, the etching rate at the top of the photoresist pillar mask and the longitudinal etching rate of the heterolayer are reduced so that the tilt angle of the heterolayer is at a first predetermined angle. The first predetermined angle is less than the sixth predetermined angle. The flow rate of the first etching gas is increased. Under an eighth predetermined condition, the photoresist pillar mask is removed, increasing the etching rate difference between the substrate and the heterolayer, so that the tilt angle of the heterolayer is at a first target angle, and the tilt angle of the substrate is at a second target angle. The first target angle is less than the second target angle. Using the above method, the substrate sidewall tilt angle is higher than the heterolayer sidewall tilt angle. With the same bottom width, this improves the volume duty cycle of the heterolayer, increases the overall light extraction efficiency of the epitaxial layer, reduces the nucleation ratio of the substrate sidewall, and improves the epitaxial quality.

[0137] Based on the same inventive concept Figures 12-14 The following are schematic diagrams of the structures of three composite patterned substrates provided in embodiments of the present invention, with reference to... Figure 10 , Figures 12-14 As shown, the composite patterned substrate is prepared using the tilt angle control method described above, and has the corresponding beneficial effects of the method.

[0138] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0139] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for controlling the tilt angle of a composite patterned substrate, characterized in that, include: A composite substrate is provided; the composite substrate includes a substrate and a heterolayer located on one side of the substrate; A photoresist layer is formed on the surface of the composite substrate, and the photoresist layer is patterned to form a photoresist pillar mask; Using a first etching process, at least a first etching gas is introduced into the reaction chamber of the first etching process to adjust the etching rate of the heterolayer and the photoresist mask, so that the tilt angle of the heterolayer is at a first preset angle α1. Using a second etching process, the first etching gas is introduced into the reaction chamber of the second etching process to remove the adhesive pillar mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1; α4 < α1; the tilt angle of the substrate is the angle between the plane containing the bottom surface of the substrate and the plane containing the sidewall of the substrate, and the tilt angle of the heterolayer is the angle between the plane containing the bottom surface of the heterolayer and the plane containing the sidewall of the heterolayer, and the included angle is an acute angle.

2. The control method according to claim 1, characterized in that, Using a first etching process, by introducing at least a first etching gas into the reaction chamber of the first etching process, the etching rate of the heterolayer and the photoresist mask is adjusted so that the tilt angle of the heterolayer is at a first preset angle α1, including: By introducing a preset flow rate of the first etching gas and the second etching gas into the reaction chamber of the first etching process, a passivation layer is formed on the sidewall of the heterolayer under a first preset condition. The etching rates of the adhesive column mask and the heterolayer are adjusted so that the tilt angle of the heterolayer is a second preset angle α2. Stop the supply of the second etching gas, and under the second preset conditions, reduce the etching rate at the top of the adhesive column mask and the longitudinal etching rate of the heterostructure, so that the tilt angle of the heterostructure is a third preset angle α3. While maintaining the cessation of the second etching gas supply, under the third preset condition, the lateral etching rate of the heterolayer is increased so that the tilt angle of the heterolayer is at the first preset angle α1; α2=α3>α1.

3. The control method according to claim 2, characterized in that, The first preset condition includes an upper RF power range of 1000W-1500W, a lower RF power range of 700W-900W, and a response time of 200s-300s; the second preset condition includes an upper RF power range of 1000W-1500W, a lower RF power range of 700W-900W, and a response time of 350s-600s; the third preset condition includes an upper RF power range of 1000W-1500W, a lower RF power range of 200W-350W, and a response time of 200s-300s.

4. The control method according to claim 1, characterized in that, Using a second etching process, the first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1, including: By introducing the first etching gas at a preset flow rate into the reaction chamber of the second etching process, under the fourth preset condition, the photoresist mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is the first target angle α4, and the tilt angle of the substrate is the second target angle β1; α4=β1.

5. The control method according to claim 2, characterized in that, Using a second etching process, the first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1, including: By introducing the first etching gas at a preset flow rate into the reaction chamber of the second etching process, under the fourth preset condition, the adhesive pillar mask is removed, and the etching rate difference between the substrate and the heterolayer is reduced, so that the tilt angle of the heterolayer is a fourth preset angle α5, and the tilt angle of the substrate is a fifth preset angle β2. A preset flow rate of the first etching gas and the second etching gas is introduced into the reaction chamber of the second etching process. Under the fifth preset condition, the bottom tilt angle of the substrate is reduced so that the tilt angle of the heterolayer is the first target angle α4 and the tilt angle of the substrate is the second target angle β1; α4=α5=β2>β1.

6. The control method according to claim 5, characterized in that, The fourth preset condition is that the upper radio frequency power range is 1000W-1500W and the lower radio frequency power range is 400W-700W; the fifth preset condition is that the upper radio frequency power range is 1000W-1500W and the lower radio frequency power range is 400W-700W.

7. The control method according to claim 1, characterized in that, Using a first etching process, by introducing at least a first etching gas into the reaction chamber of the first etching process, the etching rate of the heterolayer and the photoresist mask is adjusted so that the tilt angle of the heterolayer is at a first preset angle α1, including: By introducing a preset flow rate of the first etching gas into the reaction chamber of the first etching process, under the sixth preset condition, the etching rate of the adhesive column mask and the heterostructure is adjusted so that the tilt angle of the heterostructure is at the sixth preset angle α6. Under the seventh preset condition, the etching rate at the top of the adhesive pillar mask and the longitudinal etching rate of the heterolayer are reduced, so that the tilt angle of the heterolayer is at the first preset angle α1; α1 < α6; Using a second etching process, the first etching gas is introduced into the reaction chamber of the second etching process to remove the photoresist mask, and the tilt angle of the heterolayer is at a first target angle α4, and the tilt angle of the substrate is at a second target angle β1, including: Increase the flow rate of the first etching gas, and under the eighth preset condition, remove the adhesive pillar mask to increase the etching rate difference between the substrate and the heterolayer, so that the tilt angle of the heterolayer is the first target angle α4 and the tilt angle of the substrate is the second target angle β1; α4 < β1.

8. The control method according to claim 7, characterized in that, The sixth preset condition is that the upper radio frequency power range is 1000W-1500W, the lower radio frequency power range is 400W-700W, and the response time is 200s-300s; the seventh preset condition is that the upper radio frequency power range is 1000W-1500W, the lower radio frequency power range is 200W-350W, and the response time is 350s-600s; the eighth preset condition is that the upper radio frequency power range is 1000W-1500W, and the lower radio frequency power range is 700W-900W.

9. The control method according to claim 2, characterized in that, The preset flow rate of the first etching gas is 90 sccm-120 sccm, and the flow rate of the second etching gas is 10 sccm-25 sccm.

10. The control method according to claim 2, characterized in that, The first etching gas includes at least boron trichloride gas or a mixture of chlorine and boron trichloride; and / or, the second etching gas includes at least nitrogen.

11. A composite patterned substrate, characterized in that, It is prepared using the tilt angle control method of the composite patterned substrate according to any one of claims 1-10.

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