Photomask and its manufacturing method

Abstract

This invention discloses a photomask and its fabrication method. The fabrication method includes preparing and etching a first inorganic material layer on a substrate to form a first pattern layer comprising multiple first patterns; forming a second inorganic material layer covering the side surface of the substrate; preparing and etching a metal layer on the first pattern layer to form a metal pattern layer comprising multiple metal patterns, with each metal pattern located between two adjacent first patterns; preparing a third inorganic material layer on the metal pattern layer; removing the second inorganic material layer in a first region and removing the substrate in the first region; and removing the first pattern layer and the third inorganic material layer. By fabricating the metal pattern layer on the substrate using semiconductor manufacturing processes, the via size on the metal pattern layer can be reduced, meeting users' requirements for high resolution in display panels.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a photomask and its fabrication method. Background Technology

[0002] Organic Light Emitting Diode (OLED) display panels are panels that use OLEDs as display pixels. Compared to traditional LCD panels, OLED display panels are becoming increasingly popular in the market due to their many advantages, such as self-illumination, low power consumption, good color performance, and applicability to flexible displays.

[0003] OLEDs are typically fabricated by depositing organic light-emitting materials onto an array substrate. This process usually requires the use of a photomask. Existing photomasks typically use metal strips and lasers to drill holes in the metal strips to create through-holes. Due to the limitations of laser drilling technology, the size of the through-holes on existing photomasks is usually quite large, which is increasingly unable to meet users' demands for high resolution display panels. Summary of the Invention

[0004] This invention provides a photomask and its manufacturing method to reduce the size of the through holes on the photomask, thereby reducing the limitation of the through hole size on the vapor deposition process and meeting users' requirements for high resolution of display panels.

[0005] According to one aspect of the present invention, a method for manufacturing a photomask is provided, the method comprising the following steps:

[0006] A substrate is provided, the substrate including a first surface and a second surface disposed opposite to each other, and a side surface disposed between the first surface and the second surface; a first inorganic material layer is formed on the first surface of the substrate; the first inorganic material layer is etched to form a first pattern layer including a plurality of first patterns, the first pattern including a first top surface away from the substrate and a first side surface connecting the first top surface, the first top surface and the first side surface having a first included angle; a second inorganic material layer is formed, the second inorganic material layer covering the side surface of the substrate; a metal layer is formed on the first pattern layer; the metal layer is etched to form a metal pattern layer including a plurality of metal patterns, each metal pattern being located between two adjacent first patterns; the metal pattern including a second top surface away from the substrate and a second side surface connecting the second top surface, the second top surface and the second side surface having a second included angle, the second included angle being complementary to the first included angle; a third inorganic material layer is formed on the metal pattern layer; the substrate is etched from one side of the second surface of the substrate, retaining the substrate in a second region and removing the substrate in the first region; wherein the second region is a peripheral region surrounding the first region; the first pattern layer and the third inorganic material layer are removed.

[0007] According to another aspect of the present invention, a photomask is provided, the photomask including a first side and a second side disposed opposite to each other, the photomask including a first region and a second region surrounding the first region; in the first region, the photomask including a plurality of metal patterns, with through holes disposed between adjacent metal patterns; on the first side of the photomask, the metal pattern including a second top surface, the metal pattern including a second side surface connected to the second top surface, the second top surface and the second side surface of the metal pattern having a second included angle; in the second region, the photomask having a first frame layer and a second frame layer, the first frame layer being made of a semiconductor material, the second frame layer being made of the same material as the metal pattern, and a second inorganic material layer being disposed between the first frame layer and the second frame layer.

[0008] The photomask and its fabrication method provided in this invention fabricate a metal pattern layer on a substrate using semiconductor manufacturing processes. Compared to traditional fine metal photomask fabrication processes, this method helps reduce the via size on the metal pattern layer, lessening the limitations imposed by via size on the vapor deposition process, and thus meeting users' high-resolution requirements for display panels. Furthermore, the substrate retained in the second region provides support and fixation for the metal pattern layer. On one hand, compared to traditional fine metal photomask fabrication processes, it reduces the rigidity requirements of the metal pattern layer, helping to reduce the thickness of the metal layer. This, in turn, helps to reduce the distance between the photomask and the substrate to be vaporized during vapor deposition, mitigating the shadowing effect during the vapor deposition process, reducing the deviation between the actual vapor-deposited film pattern size and the design value, and improving the accuracy of the vapor deposition process. On the other hand, compared to methods that weld the photomask to the photomask frame using laser welding, it prevents displacement between the metal pattern layer and the substrate, further improving the precision of the vapor deposition process.

[0009] 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

[0010] 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.

[0011] Figure 1 This is a schematic diagram of a partial cross-sectional structure of a display panel in related technologies;

[0012] Figure 2 This is a schematic diagram of a partial cross-sectional structure of a display panel provided in an embodiment of the present invention;

[0013] Figure 3 A schematic flowchart illustrating a method for fabricating a photomask according to an embodiment of the present invention;

[0014] Figures 4-14 A schematic diagram of the process structure of a method for fabricating a photomask provided in an embodiment of the present invention;

[0015] Figure 15 A schematic diagram of the process structure of another method for fabricating a photomask provided in an embodiment of the present invention;

[0016] Figure 16 A schematic diagram of a photomask provided in an embodiment of the present invention;

[0017] Figure 17 A schematic diagram of a vapor deposition process provided for related technologies;

[0018] Figure 18 This is a schematic diagram of a vapor deposition process using the photomask provided in an embodiment of the present invention;

[0019] Figure 19 A comparative schematic diagram of metal patterns;

[0020] Figure 20 A schematic diagram of a substrate provided in an embodiment of the present invention;

[0021] Figure 21 A schematic diagram of a photomask provided in an embodiment of the present invention;

[0022] Figure 22 for Figure 21 A schematic diagram of the cross-sectional structure along the A-A' direction;

[0023] Figure 23 A schematic diagram of the cross-sectional structure of a photomask provided in an embodiment of the present invention;

[0024] Figure 24 A schematic diagram of the cross-sectional structure of another mask provided in an embodiment of the present invention;

[0025] Figure 25 A schematic diagram of the cross-sectional structure of another mask provided in an embodiment of the present invention;

[0026] Figure 26 This is a schematic diagram of the cross-sectional structure of another mask provided in an embodiment of the present invention. Detailed Implementation

[0027] 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 of the present invention. 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.

[0028] 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 a 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.

[0029] Figure 1 This is a schematic diagram of a partial cross-sectional structure of a display panel in related technologies, such as... Figure 1 As shown, the display panel uses a white-emitting organic light-emitting diode 10 combined with a color filter (CF) 11 to achieve color image display.

[0030] The organic light-emitting diode (OLED) 10 includes an anode 101, an organic light-emitting material layer 102, and a cathode 103 stacked on one side of the array substrate 13. When electrons and holes are injected into the organic light-emitting material layer 102 from the cathode 103 and the anode 101, respectively, they recombine in the organic light-emitting material layer 102, releasing energy and emitting light. The material of the organic light-emitting material layer 102 determines the emission color of the OLED 10. In this embodiment, since all OLEDs 10 emit white light, the organic light-emitting material layer 102 in all OLEDs 10 can use the same organic material. Therefore, the organic light-emitting material layer 102 can be fabricated as a single layer. Thus, in the fabrication process of this display panel, an open mask can be used to deposit organic material on the array substrate 13 to form the organic light-emitting material layer 102.

[0031] It should be noted that an open mask refers to a mask with a large opening area, which is suitable for forming a film layer with a large coverage area on the array substrate 13. When the organic light-emitting material layer 102 is deposited through the open mask, the opening of the open mask can correspond to the entire display area of ​​the display panel, so that the orthographic projection of the deposited organic light-emitting material layer 102 in the plane of the display panel covers the entire display area of ​​the display panel.

[0032] However, in Figure 1 In the color display scheme shown, the color gamut of the color filter 11 limits the color gamut range of the display panel, thus affecting the final display effect of the display panel.

[0033] Based on the above technical issues Figure 2 This is a partial cross-sectional structural diagram of a display panel provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the display panel uses organic light-emitting diodes 10 that emit different colors of light to achieve color image display, for example, Figure 2 The organic light-emitting diodes 10 in the display panel include a red organic light-emitting diode 10R, a green organic light-emitting diode 10G, and a blue organic light-emitting diode 10B to achieve color image display. Compared with display panels that use color filters to achieve color image display, this display panel has a high color gamut, thereby improving the color image display effect of the display panel.

[0034] Continue to refer to Figure 2 In this display panel, the red organic light-emitting diode 10R includes a red organic light-emitting material layer 102R, the green organic light-emitting diode 10G includes a green organic light-emitting material layer 102G, and the blue organic light-emitting diode 10B includes a blue organic light-emitting material layer 102B. The organic materials of the red organic light-emitting material layer 102R, the green organic light-emitting material layer 102G, and the blue organic light-emitting material layer 102B are typically different. Therefore, in the fabrication process of this display panel, a fine metal mask is required. A red organic light-emitting material layer 102R, a green organic light-emitting material layer 102G, and a blue organic light-emitting material layer 102B are formed by evaporating a metal mask (FMM). The fine metal mask needs to have a large number of through holes, and the size of the through holes is comparable to the size of each organic light-emitting diode 10. It can be understood that the higher the display resolution of the display panel, the smaller the size of the organic light-emitting diode 10 in the display panel. When evaporating the organic light-emitting material layer 102 of the organic light-emitting diode 10 using the fine metal mask, the size of the through holes on the fine metal mask required is smaller. Therefore, the display resolution of the display panel is limited by the size of the through holes on the fine metal mask.

[0035] Existing fine metal photomasks typically use metal strips and lasers to drill holes in the strips to create through-holes. Due to the precision limitations of laser drilling technology, the through-holes on existing fine metal photomasks are usually quite large, which is increasingly unable to meet users' demands for high resolution display panels.

[0036] Meanwhile, when using existing fine metal masks for vapor deposition, the fine metal mask usually needs to be welded to the mask frame for support and fixation before being placed in the vapor deposition machine. During the welding process, problems such as uneven tension or thermal effects applied to the fine metal mask can easily occur, causing displacement between the fine metal mask and the mask frame, which affects the vapor deposition accuracy of the fine metal mask.

[0037] To address the aforementioned technical problems, embodiments of the present invention provide a method for fabricating a photomask and the photomask itself. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] Figure 3 This is a schematic flowchart illustrating a method for fabricating a photomask according to an embodiment of the present invention. Figures 4-14 This is a schematic diagram of the process structure of a method for fabricating a photomask provided in an embodiment of the present invention, as shown below. Figures 3-14 As shown, the method includes:

[0039] Step S110: Provide a substrate 20, which includes a first surface 201 and a second surface 202 disposed opposite to each other, and a side surface 203 disposed between the first surface 201 and the second surface 202.

[0040] Specifically, such as Figure 4 As shown, the substrate 20 has a first surface 201 and a second surface 202 opposite to the first surface 201, and a side surface 203 connects the first surface 201 and the second surface 202. The first surface 201 is the bearing surface for the subsequently formed film layer, and the second surface 202 is the etching surface for the subsequent etching of the substrate 20.

[0041] The substrate 20 can be a semiconductor substrate, which can be a type of substrate commonly used in semiconductor manufacturing processes, such as a wafer, but is not limited to this.

[0042] Optionally, the material of the substrate 20 includes at least one of silicon nitride, single-crystal silicon, germanium, silicon germanide, silicon carbide, gallium arsenide, and indium gallium nitride.

[0043] The use of the aforementioned material in the substrate 20 makes it more suitable for the requirements of subsequent semiconductor manufacturing processes and helps to improve the quality of the film layer prepared later.

[0044] Step S120: A first inorganic material layer 21 is formed on the first surface 201 of the substrate 20.

[0045] Among them, such as Figure 5 As shown, the first inorganic material layer 21 is used to provide a process basis for subsequent etching of the metal layer to form a metal pattern layer with multiple metal patterns.

[0046] Optionally, the thickness of the first inorganic material layer 21 is 1 μm or less, and the thickness of the first inorganic material layer 21 is the same as or approximately the thickness of the metal pattern layer to which multiple metal patterns are to be formed subsequently.

[0047] In some embodiments, a first inorganic material layer 21 can be formed on the first surface 201 of the substrate 20 by chemical vapor deposition (CVD). CVD primarily utilizes one or more gaseous compounds or elements containing thin film elements to chemically react on the substrate surface to generate a thin film. In this embodiment, using CVD to form the first inorganic material layer 21 offers advantages such as low deposition temperature, easy control of film composition and thickness, good uniformity and repeatability, wide applicability, and simple equipment.

[0048] In other embodiments, a first inorganic material layer 21 can also be formed on the first surface 201 of the substrate 20 using plasma-enhanced chemical vapor deposition (PECVD). PECVD is a method of epitaxy in which gas is excited to generate a low-temperature plasma during chemical vapor deposition, enhancing the chemical activity of the reactants. In this embodiment, using PECVD to form the first inorganic material layer 21 offers advantages such as low deposition temperature, good film thickness and composition uniformity, strong film adhesion, and wide applicability.

[0049] Furthermore, in order to reduce the process difficulty of fabricating the first inorganic material layer 21, the first inorganic material layer 21 can be made of commonly used materials with high process integration, such as silicon oxide, silicon nitride, silicon oxynitride, etc. The embodiments of the present invention do not make specific limitations on this.

[0050] Step S130: Etch the first inorganic material layer 21 to form a first pattern layer 22 including a plurality of first patterns 221. The first pattern 221 includes a first top surface 2211 away from the substrate 20 and a first side surface 2212 connecting the first top surface 2211. The first top surface 2211 and the first side surface 2212 have a first included angle θ1.

[0051] Specifically, such as Figure 5 and Figure 6 As shown, the first inorganic material layer 21 can be etched using a dry etching process, which is a thin-film etching technique utilizing plasma. In this embodiment, when using a dry etching process to etch the first inorganic material layer 21, a suitable gas can be selected based on the material of the first inorganic material layer 21 to react with the material of the first inorganic material layer 21 more quickly, achieving the purpose of etching removal. Dry etching has advantages such as controllability, flexibility, good repeatability, safe operation, easy automation, no chemical waste liquid, no pollution introduced during the process, and high cleanliness.

[0052] Continue to refer to Figure 5 and Figure 6 After the first inorganic material layer 21 is etched, a patterned first graphic layer 22 will be formed. The first graphic layer 22 has multiple first graphics 221. The first graphic 221 includes a first top surface 2211 away from the substrate 20, and also includes a first side surface 2212 connected to the first top surface 2211. A first included angle θ1 is formed between the first top surface 2211 and the first side surface 2212.

[0053] The first pattern layer 22 is used to provide a process basis for the subsequent etching of the metal layer, wherein the pattern of the first pattern layer 22 is complementary to the pattern of the subsequently formed metal pattern layer with multiple metal patterns.

[0054] In the first graphic layer 22, a first included angle θ1 is formed between the first top surface 2211 and the first side surface 2212 of the first graphic 221. The first included angle θ1 can determine the included angle of the subsequent formation of the metal graphic.

[0055] Step S140: Form a second inorganic material layer 25, the second inorganic material layer 25 at least covering the side surface 203 of the substrate 20.

[0056] Specifically, such as Figure 7 As shown, the second inorganic material layer 25 is used to protect the side surface 203 of the substrate 20. When the second surface 202 of the substrate 20 is subsequently etched, the side surface 203 can be protected.

[0057] Optionally, a second inorganic material layer 25 may be provided to cover the side surface 203 of the substrate 20, the surface of the first patterned layer 22, and the first surface 201 of the substrate 20 exposed to the surface of the first patterned layer 22. In addition to protecting the side surface 203 of the substrate 20, the second inorganic material layer 25 covering the surface of the first patterned layer 22 and the first surface 201 of the substrate 20 exposed to the surface of the first patterned layer 22 can provide buffering, protection, and fixation for the first patterned layer 22.

[0058] Optionally, such as Figure 7 As shown, a second inorganic material layer 25 can also be provided to cover the surface of the first patterned layer 22, with the first surface 201 of the substrate 20 exposed to the surface of the first patterned layer 22 and the second surface 202 and side surface 203 of the substrate 20, so that the second inorganic material layer 25 can provide all-round protection for the first patterned layer 22 and the substrate 20.

[0059] Optionally, the second inorganic material layer 25 can be silicon oxide, silicon nitride, silicon oxynitride, etc., to provide good protection.

[0060] In addition, the thickness of the second inorganic material layer 25 can be between 0.1 μm and 1 μm, which can provide good protection while helping to control costs.

[0061] Optionally, the second inorganic material layer 25 can be prepared by low-pressure chemical vapor deposition (LPCVD). LPCVD involves heating the substrate under low-pressure conditions to react and deposit a gaseous compound onto the substrate surface, forming a stable solid film. In this embodiment, using LPCVD to form the second inorganic material layer 25 achieves a high deposition rate and throughput, ensuring that the second inorganic material layer 25 has excellent step coverage.

[0062] Furthermore, in order to reduce the process difficulty of fabricating the second inorganic material layer 25, the second inorganic material layer 25 can be made of commonly used materials with high process integration, such as silicon nitride, etc., and the embodiments of the present invention do not limit this.

[0063] Step S150: Form a metal layer 23 on the first pattern layer 22.

[0064] It should be noted that in step S140, if the second inorganic material layer 25 covers the surface of the first patterned layer 22 and the first surface 201 of the substrate 20 is exposed to the surface of the first patterned layer 22, then as follows: Figure 8 As shown, a metal layer 23 is formed on the first patterned layer 22 covering the second inorganic material layer 25. "On the first patterned layer 22" is a directional description and does not imply that the metal layer 23 must be in direct contact with the first patterned layer 22. Specifically, as... Figure 8 As shown, a metal layer 23 is formed on the second inorganic material layer 25, wherein the metal layer 23 is located on the side of the first patterned layer 22 away from the substrate 20, and the bottom surface of the metal layer 23 near the substrate 20 matches the surface of the first patterned layer 22 away from the substrate 20.

[0065] Optionally, the metal layer 23 can be prepared using physical vapor deposition (PVD). PVD refers to a technique that uses physical methods under vacuum conditions to vaporize the surface of a material source (solid or liquid) into gaseous atoms or molecules, or partially ionize them into ions, and then deposits a thin film on the substrate surface through a low-pressure gas (or plasma) process. In this embodiment, the metal layer 23 is formed using physical vapor deposition, which has advantages such as a simple process, no pollution, low material consumption, uniform and dense film formation, and strong adhesion to the substrate.

[0066] Step S160: Etch metal layer 23 to form metal pattern layer 24 including multiple metal patterns 241, each metal pattern 241 being located between two adjacent first patterns 221; metal pattern 241 includes a second top surface 2411 away from substrate 20, and a second side surface 2412 connecting the second top surface 2411, the second top surface 2411 and the second side surface 2412 having a second included angle θ2, the second included angle θ2 and the first included angle θ1 being complementary.

[0067] Specifically, the metal layer 23 can be etched using Chemical Mechanical Polishing (CMP). CMP combines surface chemical action with mechanical polishing techniques to remove micron / nanoscale materials from the film surface. The main working principle of CMP is that, under certain pressure and in the presence of a polishing slurry, the film being polished moves relative to the polishing pad. Through the highly organic combination of the mechanical polishing action of the nano-abrasives and the chemical action of various chemical reagents, the thickness of the polished film is reduced, and the surface of the polished film achieves high flatness, low surface roughness, and low defects.

[0068] During the etching of the metal layer 23, the surface of the metal layer 23 facing away from the substrate 20 is ground until the first pattern layer 22 is exposed, thereby enabling the metal layer 23 to form a metal pattern layer 24 that is complementary to the pattern of the first pattern layer 22.

[0069] Optionally, in step S140, if the second inorganic material layer 25 covers the surface of the first patterned layer 22 and the first surface 201 of the substrate 20 is exposed on the surface of the first patterned layer 22, then during the etching of the metal layer 23, the surface of the metal layer 23 facing away from the substrate 20 is ground until the second inorganic material layer 25 is exposed, thereby allowing the metal layer 23 to form a metal patterned layer 24 that is complementary to the pattern of the first patterned layer 22, such as... Figure 9 As shown.

[0070] In subsequent actual use of the photomask, the surface of the metal pattern layer 24 facing the substrate 20 can be oriented towards the evaporation source, and the surface of the metal pattern layer 24 facing away from the substrate 20 can be oriented towards the substrate to be vaporized. The vaporization material from the evaporation source is vaporized onto the substrate to be vaporized through the metal pattern layer 24 to form a thin film with a preset pattern.

[0071] It should be noted that, as Figure 8 and Figure 9As shown, in an optional embodiment, the metal layer 23 is prepared on the second inorganic material layer 25, which is disposed across the entire surface. During the grinding of the metal layer 23, the second inorganic material layer 25 can buffer, protect, and fix the first patterned layer 22, thereby preventing damage or misalignment of the patterned first patterned layer 22 caused by the frictional force applied during grinding, and improving the accuracy of the patterning of the metal patterned layer 24. Furthermore, the adhesion between the metal layer 23 and the second inorganic material layer 25 is also relatively good. Therefore, preparing the metal layer 23 on the second inorganic material layer 25, which is disposed across the entire surface, can also reduce the risk of the metal layer 23 detaching from the second inorganic material layer 25 during grinding, which is beneficial for the smooth progress of the etching process.

[0072] Continue to refer to Figure 8 and Figure 9 The metal pattern layer 24 includes a metal pattern 241 located between two adjacent first patterns 221. After the first pattern 221 is subsequently removed, a through hole matching the first pattern 221 will be formed on the metal pattern layer 24 at the location of the first pattern 221, and the through hole penetrates the metal pattern layer 24. During the vapor deposition process, a thin film with a preset pattern is formed through the through hole on the metal pattern layer 24.

[0073] Among them, such as Figure 9 As shown, the metal pattern 241 includes a second top surface 2411 and a second side surface 2412. The second top surface 2411 is the surface of the metal pattern 241 facing away from the substrate 20. The second top surface 2411 is parallel to the first surface 201 of the substrate 20. The second side surface 2412 is parallel to the first side surface 2212 of the first pattern 221.

[0074] Furthermore, such as Figure 9 As shown, the second included angle θ2 between the second top surface 2411 and the second side surface 2412 of the metal pattern 241 is complementary to the first included angle θ1 between the first top surface 2211 and the first side surface 2212 of the first pattern 221; that is, the sum of the second included angle θ2 and the first included angle θ1 is equal to 180 degrees. It can be understood that the pattern of the metal pattern layer 24 is determined by the pattern of the first pattern layer 22, and the second included angle θ2 between the second top surface 2411 and the second side surface 2412 of the metal pattern 241 is determined by the first included angle θ1 between the first top surface 2211 and the first side surface 2212 of the first pattern 221. Therefore, the pattern of the first pattern layer 22 and the size of the first included angle θ1 can be set according to the preset pattern of the metal pattern 241 to be formed and the required size of the second included angle θ2. This embodiment of the invention does not specifically limit this.

[0075] It should be noted that, in order to reduce the difficulty of the mask fabrication process, materials that are commonly used in the process and have a high degree of process integration can be selected as the material for the metal layer 23.

[0076] Optionally, the material of the metal layer 23 includes nickel, iron, titanium, tantalum or tungsten, or the material of the metal layer 23 includes an alloy of at least one of nickel, iron, titanium, tantalum and tungsten.

[0077] The metal layer 23 is made of the above-mentioned material or an alloy of the above-mentioned material, which can make the metal layer 23 have good rigidity and not easily deformed. This can improve the mechanical strength of the metal pattern layer 24 formed by the metal layer 23. When the metal pattern layer 24 is used for subsequent vapor deposition, the probability of the metal pattern layer 24 bending, deforming or breaking can be reduced, which is beneficial to improving the quality of the mask and the accuracy of vapor deposition.

[0078] Optionally, the thickness of the metal layer 23 is less than or equal to 1 μm.

[0079] In this embodiment, the metal pattern layer 24 is formed on the substrate 20 through semiconductor manufacturing process. The substrate 20 can support and fix the metal pattern layer 24. Compared with the traditional fine metal mask manufacturing process, the rigidity requirement of the metal pattern layer 24 can be reduced, which is beneficial to reducing the thickness of the metal layer 23.

[0080] In this embodiment of the invention, the thickness of the metal layer 23 can be set to 1 μm or less. Correspondingly, the thickness of the metal pattern layer 24 formed by etching the metal layer 23 is also 1 μm or less. While ensuring that the metal pattern layer 24 is not easily broken during the use of the mask, it is beneficial to reduce the distance between the mask and the substrate to be vaporized during evaporation, thereby reducing the shadow effect during evaporation, reducing the deviation between the actual vaporized film pattern size and the design value, and improving the accuracy of the evaporation process.

[0081] Furthermore, during the etching of the metal layer 23, the surface of the metal layer 23 facing away from the substrate 20 is ground until the first pattern layer 22 is exposed, or until the second inorganic material layer 25 is exposed. The thickness of the final metal pattern layer 24 is usually equal to or less than the thickness of the first pattern layer 22. Therefore, in this embodiment of the invention, the thickness of the first inorganic material layer 21 can be set to 1 μm or less, so that the thickness of the first pattern layer 22 formed by the first inorganic material layer 21 is 1 μm or less, thereby matching the thickness of the first pattern layer 22 with the required thickness of the metal pattern layer 24, which is beneficial for forming a thinner metal pattern layer 24.

[0082] Step S170: Form a third inorganic material layer 26 on the metal pattern layer 24.

[0083] Among them, such as Figure 10As shown, the third inorganic material layer 26 can support and protect the metal pattern layer 24 during the subsequent etching of the substrate 20, thereby reducing the probability of the metal pattern layer 24 falling off, bending, deforming or breaking, which is conducive to further improving the quality of the mask.

[0084] Optionally, the thickness of the third inorganic material layer 26 can be between 0.1 and 10 μm, which can provide good support and protection for the metal pattern layer 24 while helping to control costs.

[0085] Specifically, such as Figure 10 As shown, a third inorganic material layer 26 can be prepared on the side of the metal pattern layer 24 away from the substrate 20 by plasma enhanced chemical vapor deposition (PECVD), which has the advantages of low deposition temperature, good thickness and composition uniformity of the film, strong adhesion of the film, and wide range of applications.

[0086] Furthermore, in order to reduce the process difficulty of fabricating the third inorganic material layer 26, the third inorganic material layer 26 can be made of materials that are commonly used in the process and have a high degree of process integration.

[0087] Optionally, the third inorganic material layer 26 includes at least one of silicon oxide, silicon nitride, and silicon oxynitride to provide good support and protection for the metal pattern layer 24. This embodiment of the invention does not specifically limit this.

[0088] Step S180: Etch the substrate 20 from the second surface 202 side of the substrate 20, retain the substrate 20 in the second region 32, and remove the substrate 20 in the first region 31; wherein, the second region 32 is the peripheral region surrounding the first region 31.

[0089] Optionally, in step S140, if the second inorganic material layer 25 covers the second surface 202 of the substrate 20, then in step S180, the second inorganic material layer 25 can be used as a mask for etching the second surface 202 of the substrate 20. Specifically, the second inorganic material layer 25 on the second surface 202 of the substrate 20 is etched, the second inorganic material layer 25 in the first region 31 is removed, and the second inorganic material layer 25 in the second region 32 is retained; wherein, the second region 32 is the peripheral region surrounding the first region 31, such as... Figure 11As shown, the substrate 20 is etched from one side of the second surface 202 of the substrate 20 using the etched second inorganic material layer 25 as a mask, retaining the substrate 20 in the second region 32 and removing the substrate 20 in the first region 31; wherein, the second region 32 is the peripheral region surrounding the first region 31. When removing the substrate 20 in the first region 31, the second inorganic material layer 25 can act as an etching mask, thereby protecting the substrate 20 in the second region 32 and the side surface 203 of the substrate 20, preventing excessive removal of the substrate 20 in the second region 32 and the side surface 203 of the substrate 20, so that the remaining substrate 20 can still support and fix the metal pattern layer 24, thereby reducing the probability of detachment between the substrate 20 and the metal pattern layer 24 and the breakage of the metal pattern layer 24.

[0090] In this embodiment, the second inorganic material layer 25 on the second surface 202 of the substrate 20 can be etched using a dry etching process. This process offers advantages such as controllability, flexibility, good repeatability, safe operation, easy automation, no chemical waste, no pollution introduced during processing, and high cleanliness. The second inorganic material layer 25 can be made of at least one of silicon oxide, silicon nitride, and silicon oxynitride, which allows for a high etching selectivity between the second inorganic material layer 25 and the substrate 20. This reduces the difficulty of removing the substrate 20 from the first region 31 and minimizes damage to the second inorganic material layer 25 during the removal process, thus providing better protection for the sides 203 and other areas of the substrate 20.

[0091] For example, such as Figure 11 As shown, when etching the second inorganic material layer 25, the mask can be flipped and etched on the second inorganic material layer 25 on the side of the substrate 20 away from the metal pattern layer 24 to remove the second inorganic material layer 25 of the first region 31 and retain the second inorganic material layer 25 of the second region 32.

[0092] Alternatively, in other embodiments, an etching barrier mask for the substrate 20 can be formed in other ways, such as forming another mask layer on one side of the second surface 202 of the substrate 20, and exposing the first region 31 and blocking the second region 32. In this case, after etching the substrate 20, the substrate 20 with the second region 32 is retained, and the substrate 20 with the first region 31 is removed.

[0093] Optionally, the substrate 20 can be etched using a wet etching process, wherein wet etching is a technique in which the etching material is immersed in an etching solution for etching.

[0094] In this embodiment, when using a wet etching process to etch the substrate 20, a suitable etching solution can be selected based on the material of the substrate 20 to react more quickly with the material of the substrate 20 and achieve the purpose of etching removal. For example, when the substrate 20 is a silicon substrate, a potassium hydroxide solution can be used to etch the substrate 20, but it is not limited to this.

[0095] The structure of the etched substrate 20 can be referenced. Figure 12 In order to enable the mask to function properly, the base 20 of the first region 31 is removed to expose the metal pattern layer 24.

[0096] Step S190: Remove the first pattern layer 22 and the third inorganic material layer 26.

[0097] In order to enable the mask to function properly, the first pattern layer 22 and the third inorganic material layer 26 are removed.

[0098] Optionally, the materials of the first inorganic material layer 21 and the third inorganic material layer 26 include at least one of silicon oxide, silicon nitride, and silicon oxynitride.

[0099] The use of the aforementioned materials in the first inorganic material layer 21 and the third inorganic material layer 26 allows for a high etching selectivity between the first pattern layer 22 and the third inorganic material layer 26 formed by the first inorganic material layer 21 and the metal pattern layer 24. This reduces the difficulty of removing the first pattern layer 22 and the third inorganic material layer 26 and minimizes damage to the metal pattern layer 24 caused by the removal of the first pattern layer 22 and the third inorganic material layer 26.

[0100] Meanwhile, since the first inorganic material layer 21 and the third inorganic material layer 26 are made of the same material, the first pattern layer 22 and the third inorganic material layer 26 formed by the first inorganic material layer 21 can be removed in the same process step, thereby simplifying the process steps and improving the efficiency of mask production.

[0101] It should be noted that the removal methods for the first graphic layer 22 and the third inorganic material layer 26 can be set according to actual needs.

[0102] Optionally, the step of removing the first patterned layer 22 and the third inorganic material layer 26 includes:

[0103] The first patterned layer 22 and the third inorganic material layer 26 are removed by dilute hydrofluoric acid (DHF).

[0104] When the first pattern layer 22 and the third inorganic material layer 26 are made of the above-mentioned materials, the first pattern layer 22 and the third inorganic material layer 26 can be removed by cleaning with dilute hydrofluoric acid (DHF) to achieve a good removal effect, but it is not limited to this.

[0105] Furthermore, in some embodiments, the removal of the first patterned layer 22 and the third inorganic material layer 26 can be carried out separately in different process steps, so that different removal methods can be selected according to the materials of the third inorganic material layer 26 and the first patterned layer 22, thereby achieving a good removal effect.

[0106] Optionally, in step S140, if the second inorganic material layer 25 covers the second surface 202 of the substrate 20, then the second inorganic material layer 25 located at least in the first region 31 also needs to be removed.

[0107] Among them, such as Figure 13 and Figure 14 As shown, in order to enable the mask to function properly, the second inorganic material layer 25 is removed to expose the metal pattern layer 24.

[0108] It should be noted that the method for removing the second inorganic material layer 25 can be set according to actual needs. Optionally, the step of removing the second inorganic material layer 25 located at least in the first region 31 includes: removing the second inorganic material layer 25 located at least in the first region 31 by dilute hydrofluoric acid (DHF).

[0109] In other embodiments, the removal of the first pattern layer 22 and the third inorganic material layer 26, as well as the removal of the second inorganic material layer 25 located at least in the first region 31, can also be performed in the same process step to simplify the process steps and improve the efficiency of mask production.

[0110] Continue to refer to Figure 14 It should be noted that in the first region 31, the substrate 20, the first pattern layer 22, the second inorganic material layer 25, and the third inorganic material layer 26 are all removed, and a hollow is formed at the location of the first pattern layer 22, thereby forming at least one through hole 242 penetrating the metal pattern layer 24. It can be understood that the through hole 242 matches the pattern of the first pattern 221. During the vapor deposition process, the vapor deposition material is deposited onto the substrate to be vapor deposited through the through hole 242 on the metal pattern layer 24 to form a thin film with a preset pattern.

[0111] Figure 14 This is a mask structure after removing the second inorganic material layer 25 located in the first region 31 of the substrate 20, the second inorganic material layer 25 located on the side 203 of the substrate 20, and the second inorganic material layer 25 in the second region 32 of the second surface 202 of the substrate 20. In this embodiment of the mask, only a portion of the second inorganic material layer 25 is retained between the substrate 20 and the metal pattern layer 24 in the second region 32.

[0112] In other embodiments, if the second inorganic material layer 25 only covers the side surface 203 of the substrate 20, then it is not necessary to etch and remove the second inorganic material layer 25. In the final mask structure, the side surface 203 of the substrate 20 still retains the second inorganic material layer 25, and the second region 32 does not have the second inorganic material layer 25 between the substrate 20 and the metal pattern layer 24; then in the second region 32, the substrate 20 and the metal pattern layer 24 are in direct contact.

[0113] In this embodiment of the invention, the first pattern layer 22 and the metal pattern layer 24 are formed by semiconductor manufacturing process. The semiconductor manufacturing process can achieve a smaller size for the first pattern layer 22 and improve the accuracy of the first pattern layer 22, which in turn helps to reduce the size of the via 242 on the metal pattern layer 24. In this embodiment of the invention, the aperture of the via 242 formed by semiconductor manufacturing process can reach 0.5μm to 10μm, achieving a smaller via size, thereby reducing the limitation of the via size 242 on the vapor deposition process, and thus meeting the user's high resolution requirements for the display panel.

[0114] It should be noted that there can be multiple through holes 242 in the first region 31. In this embodiment, for ease of illustration, only two through holes 242 and the first region 31 corresponding to the through holes 242 are shown, but it is not limited to this.

[0115] In summary, the mask fabrication method provided in this embodiment of the invention involves preparing and etching a first inorganic material layer on a first surface of a substrate to form a first pattern layer comprising multiple first patterns. A second inorganic material layer is then prepared on a side surface of the substrate. Next, a metal layer is prepared and etched to form a metal pattern layer comprising multiple metal patterns, each metal pattern located between two adjacent first patterns. A third inorganic material layer is formed on the metal layer, and the third inorganic material layer of the substrate is etched. Then, the substrate is etched from one side of the second surface, retaining the substrate in the second region and removing the substrate in the first region. Finally, the first pattern layer and the third inorganic material layer are removed. This method of fabricating the metal pattern layer on the substrate using semiconductor manufacturing processes, compared to traditional fine metal mask fabrication processes, helps to reduce the via size on the metal pattern layer, lessening the limitation of via size on the vapor deposition process, and thus meeting users' high-resolution requirements for display panels. Furthermore, the substrate retained in the second region can support and fix the metal pattern layer. On the one hand, compared with the traditional fine metal mask manufacturing process, it can reduce the rigidity requirements of the metal pattern layer, which helps to reduce the thickness of the metal layer. This is beneficial to reduce the distance between the mask and the substrate to be vaporized during evaporation, reduce the shadowing effect during evaporation, reduce the deviation between the actual vaporized film pattern size and the design value, and improve the accuracy of the evaporation process. On the other hand, compared with the solution of welding the mask to the mask frame by laser welding, it can prevent displacement between the metal pattern layer and the substrate, which is beneficial to improving the accuracy of the evaporation process.

[0116] Figure 15 A schematic diagram of the process structure of another method for fabricating a photomask provided in an embodiment of the present invention is shown below. Figure 15 As shown, optionally, before the second inorganic material layer 25 covers the surface of the first patterned layer 22 and the first surface 201 of the substrate 20 is exposed to the surface of the first patterned layer 22, and before the metal layer 23 is formed on the first patterned layer 22, the method further includes:

[0117] A recessed structure 251 is formed on the surface of the second inorganic material layer 25.

[0118] Among them, such as Figure 15 As shown in (a) and 15(b), a recessed structure 251 is prepared on the second inorganic material layer 25 on the side facing the metal layer 23, which can increase the adhesion between the metal layer 23 and the second inorganic material layer 25. This reduces the risk of the metal layer 23 falling off the second inorganic material layer 25 when the metal layer 23 is etched by chemical mechanical polishing (CMP), which is beneficial to the smooth progress of the etching process.

[0119] It should be noted that the recessed structure 251 can be formed on the surface of the second inorganic material layer 25 by etching, but it is not limited to this. Those skilled in the art can choose the method of forming the recessed structure 251 according to actual needs.

[0120] Other process flows such as Figure 15 (c) to Figure 15 As shown in (i), its process flow is the same as or similar to that described above, and will not be repeated here.

[0121] Figure 16 This is a schematic diagram of a mask structure provided in an embodiment of the present invention, as shown below. Figure 15 and Figure 16 As shown, optionally, the ratio between the depth of the recessed structure 251 and the thickness of the second inorganic material layer 25 is greater than or equal to 5%.

[0122] By setting the depth of the recessed structure 251 to 5% or more of the thickness of the second inorganic material layer 25, it is possible to ensure good adhesion between the metal layer 23 and the second inorganic material layer 25 when etching the metal layer 23. This prevents the metal layer 23 from falling off the second inorganic material layer 25 when etching the metal layer 23 by chemical mechanical polishing, thus ensuring the smooth progress of the etching process.

[0123] It should be noted that the specific value of the depth of the recessed structure 251 can be set according to actual needs. It can be understood that the greater the ratio between the depth of the recessed structure 251 and the thickness of the second inorganic material layer 25, the better the adhesion between the metal layer 23 and the second inorganic material layer 25. This embodiment of the invention does not make specific limitations on this.

[0124] Continue to refer to Figures 3-16 Optionally, the first included angle θ1 is greater than or equal to 130 degrees, and the second included angle θ2 is less than or equal to 50 degrees.

[0125] Specifically, Figure 17 A schematic diagram of a vapor deposition process is provided for related technologies, such as... Figure 17As shown, during the vapor deposition process, there is a certain relative movement between the evaporation source 14 and the substrate 17 to be vaporized. The vapor deposition material is heated and vaporized in the evaporation source 14, sprayed through the nozzle 15, and then evaporated onto the substrate 17 through the through-holes between the metal patterns 161, forming a corresponding vapor deposition film layer 28. The inventors discovered that when the angle θ between the face of the metal pattern 161 facing the substrate 17 and its side surface is large, the vapor deposition material sprayed from the nozzle 15 is in a beam-like spray during the vapor deposition process, and the metal pattern 161 will obstruct the vapor deposition material. Specifically, when the angle θ is large, the vertex 1611 of the metal pattern 161 near the evaporation source 14 will create a large obstruction area 19. In the obstruction area 19, the vapor deposition material cannot be uniformly deposited, resulting in poor vapor deposition.

[0126] Based on the above technical issues, such as Figures 4-16 As shown, in this embodiment, the first included angle θ1 is set to be greater than or equal to 130 degrees, and the second included angle θ2 is set to be less than or equal to 50 degrees, that is, the included angle between the second top surface 2411 and the second side surface 2412 of the metal pattern 241 is less than or equal to 50 degrees. Specifically, refer to Figure 18 , Figure 18 This is a schematic diagram of the vapor deposition process using the mask provided in this embodiment of the invention. In the actual use of the mask, the second top surface 2411 of the metal pattern 241 faces the substrate 37 to be vapor deposited, and the second included angle θ2 is less than or equal to 50 degrees. That is, the included angle between the side of the metal pattern 241 of the mask facing the substrate 37 to be vapor deposited and its side surface is less than or equal to 50 degrees. This can reduce the obstruction of the vapor deposition material by the metal pattern 241, allowing more vapor deposition material to pass through the through-hole 242. This can increase the area of ​​the vapor deposition film layer 38 deposited on the substrate 37 to be vapor deposited, thereby improving the flatness of the edge area of ​​the vapor deposition film layer 38 and improving the phenomenon of subsequent material film layers breaking due to the low flatness of the film layer.

[0127] It should be noted that, considering that the size of the through hole 242 of the metal pattern layer 24 on the mask is designed according to the preset pattern size, the size of the through hole 242 can be adjusted as needed while implementing the scheme of the present invention, so as to ensure that the deviation between the pattern size of the actual vapor-deposited film layer 28 and the design value is small.

[0128] Furthermore, the specific values ​​of the first included angle θ1 and the second included angle θ2 can be set according to actual needs, for example, such as... Figure 18As shown, the evaporation angle α of the vapor-deposited material ejected from the nozzle 35 can be limited by the angle limiting plate 36. A second included angle θ2 can be set to be less than or equal to the evaporation angle α, so that the metal pattern 241 can block the film-forming area. Here, the evaporation angle α is the maximum divergence angle of the vaporized vapor-deposited material after it is ejected from the nozzle 35 and limited by the angle limiting plate 36. For example... Figure 18 As shown, the second included angle θ2 is set to be less than or equal to the evaporation angle α, so that the second included angle θ2 has a small angle range. Even the vapor deposition material with the largest diffusion angle will not be blocked by the vertex of the metal pattern 241 on the side close to the evaporation source 34. This can increase the area of ​​the vapor deposition material deposited on the substrate 37 to be vapor deposition, thereby improving the flatness of the edge region of the vapor deposition film 38. This improves the phenomenon that other material films formed subsequently are broken due to the low flatness of the film layer. However, it is not limited to this. The embodiments of the present invention do not make specific limitations in this regard.

[0129] It is understandable that since the first included angle θ1 and the second included angle θ2 are complementary angles, once the angle value of one of the first included angle θ1 and the second included angle θ2 is determined, the corresponding angle value of the other is also determined. For example, if the first included angle θ1 is set to 135 degrees, then the second included angle θ2 formed subsequently will be 45 degrees. Those skilled in the art can set it according to actual needs.

[0130] The mask fabrication method and the mask obtained by the method provided in this embodiment of the invention have the following advantages: the metal pattern of the mask is formed by semiconductor film deposition process, and can be set to be very thin, such as 1μm or less, so that the second included angle θ2 can be set to be small. Figure 19 This is a comparative illustration of metal patterns, for reference. Figure 19 When the width of the metal pattern is the same, such as the width d of metal pattern 161 in related technologies and metal pattern 241 in this embodiment of the invention, but the thickness of metal pattern 241 is less than the thickness of metal pattern 161, and the second included angle θ2 of metal pattern 241 is less than the included angle θ of metal pattern 161, metal pattern 241 can reduce the obstruction of the vapor deposition area and improve the vapor deposition film formation effect. In addition, the metal pattern is formed by semiconductor etching process, and its width is very small. Compared with the existing technology of forming through holes by drilling holes in metal strips with lasers, the size of its through hole 242 is also very small, which is very suitable for the film formation process of small-size, high-precision display panels.

[0131] Figure 20 A schematic diagram of a substrate provided in an embodiment of the present invention, such as... Figure 20 As shown, optionally, the base 20 is circular in shape.

[0132] Since the substrates used to fabricate semiconductor films, such as silicon wafers, are typically circular, in this embodiment, by setting the shape of the substrate 20 to be circular, the cutting of the substrate 20 can be reduced, thereby simplifying the process steps and improving the efficiency of mask fabrication. However, the invention is not limited to this; the shape of the substrate 20 can also be square or other shapes.

[0133] Based on the same inventive concept, this embodiment of the invention also provides a photomask, which can be manufactured using the photomask manufacturing method provided in any of the above embodiments. Therefore, the photomask provided in this embodiment of the invention can have the technical effects of the technical solutions in any of the above embodiments. The explanations of the same or corresponding structures and terms as those in the above embodiments will not be repeated here.

[0134] Figure 21 This is a schematic diagram of a photomask provided in an embodiment of the present invention. Figure 22 for Figure 21 A schematic diagram of the cross-sectional structure along the A-A' direction, as shown below. Figure 21 and Figure 22 As shown, the photomask includes a first side 41 and a second side 42 disposed opposite to each other, wherein the first side 41 is the side facing the evaporation source; the photomask includes a first region 31 and a second region 32 surrounding the first region 31. In the first region 31, the photomask includes a plurality of metal patterns 241, with through holes 242 disposed between adjacent metal patterns 241. On the first side 41 of the photomask, the metal pattern 241 includes a second top surface 2411, and the metal pattern 241 also includes a second side surface 2412 connected to the second top surface 2411. A second included angle θ2 is formed between the second top surface 2411 and the second side surface 2412 of the metal pattern 241. In the second region 32, the photomask has a first frame layer 51 and a second frame layer 52. The material of the first frame layer 51 is a semiconductor material, and the material of the second frame layer 52 is the same as the material of the metal patterns 241. A second inorganic material layer 25 is also disposed between the first frame layer 51 and the second frame layer 52.

[0135] Specifically, such as Figure 21 and Figure 22 As shown, the photomask has a first region 31 and a second region 32 surrounding the first region 31. The photomask has multiple metal patterns 241 in the first region 31, which constitute a metal pattern layer 24. Through holes 242 are provided between adjacent metal patterns 241 and penetrate the metal pattern layer 24. During the vapor deposition process, a thin film with a preset pattern is formed through the through holes 242 on the metal pattern layer 24.

[0136] Continue to refer to Figure 21 and Figure 22The surface of the metal pattern 241 facing the first side 41 of the mask is a second top surface 2411. The metal pattern 241 also includes a second side surface 2412 connected to the second top surface 2411. A second included angle θ2 exists between the second top surface 2411 and the second side surface 2412 of the metal pattern 241. The specific value of the second included angle θ2 can be set according to actual needs, and this embodiment of the invention does not impose a specific limitation on it.

[0137] Continue to refer to Figure 21 and Figure 22 In the second region 32, the mask has a first frame layer 51 and a second frame layer 52, the first frame layer 51 being located on the second side 42 of the mask, and the second frame layer 52 being located on the first side 41 of the mask.

[0138] The material of the second frame layer 52 is the same as that of the metal pattern 241, so that the second frame layer 52 and the metal pattern 241 can be fabricated in the same process step, thereby simplifying the process steps and improving the efficiency of mask fabrication.

[0139] Meanwhile, the first frame layer 51 is made of semiconductor material. The first frame layer 51 is used to support and fix the second frame layer 52 in the second region 32. On the one hand, compared with the traditional fine metal mask manufacturing process, the rigidity requirement of the second frame layer 52 can be reduced, which helps to reduce the thickness of the second frame layer 52. This helps to reduce the distance between the mask and the substrate to be vaporized during evaporation, reduce the shadowing effect during evaporation, reduce the deviation between the actual vaporized film pattern size and the design value, and improve the accuracy of the evaporation process. On the other hand, compared with the solution of welding the mask to the mask frame by laser welding, it can prevent the displacement between the first frame layer 51 and the second frame layer 52, which helps to improve the accuracy of the evaporation process.

[0140] The first frame layer 51 can be made of a substrate material commonly used in semiconductor manufacturing processes. During mask fabrication, multiple metal patterns 241 can be fabricated on the substrate using semiconductor processes. This helps reduce the size of the vias 242, lessening the limitations imposed by the via size on the vapor deposition process, and thus meeting users' high-resolution requirements for the display panel. Subsequently, the substrate is etched, retaining the substrate in the second region 32 and removing the substrate in the first region 31, thereby forming the first frame layer 51.

[0141] Optionally, the material of the first framework layer 51 includes at least one of silicon nitride and monocrystalline silicon.

[0142] The first frame layer 51 uses the aforementioned material, which is more suitable for semiconductor manufacturing process requirements when preparing the mask, and helps to improve the film quality of the mask.

[0143] Optionally, the thickness of the metal pattern 241 is less than or equal to 1 μm.

[0144] The metal pattern 241 can be formed on the substrate through semiconductor manufacturing process. The substrate can support and fix the metal pattern 241. Compared with the traditional fine metal mask manufacturing process, the rigidity requirement of the metal pattern 241 can be reduced, which is conducive to reducing the thickness of the metal pattern 241.

[0145] In this embodiment of the invention, the thickness of the metal pattern 241 can be set to 1 μm or less. While ensuring that the metal pattern 241 is not easily broken during the use of the mask, it is beneficial to reduce the distance between the mask and the substrate to be vaporized during the vapor deposition process. This reduces the shadow effect during the vapor deposition process, reduces the deviation between the actual vapor-deposited film pattern size and the design value, and improves the accuracy of the vapor deposition process.

[0146] Continue to refer to Figure 21 and Figure 22 The degree measure of the second included angle θ2 is less than or equal to 50 degrees.

[0147] Among them, such as Figure 18 As shown, in the actual use of the photomask, the second top surface 2411 of the metal pattern 241 can be oriented towards the substrate 37 to be vaporized. By setting the second included angle θ2 to be less than or equal to 50 degrees, the obstruction of the vaporization area by the metal pattern 241 can be reduced, thereby increasing the area of ​​the vaporized film layer 38 deposited on the substrate 37 to be vaporized. This can further improve the flatness of the edge area of ​​the vaporized film layer 38 and improve the phenomenon that subsequent material films are broken due to the low flatness of the film layer.

[0148] It should be noted that, considering that the size of the through hole 242 of the metal pattern layer 24 on the mask is designed according to the preset pattern size, the size of the through hole 242 can be adjusted as needed while implementing the scheme of the present invention, so as to ensure that the deviation between the pattern size of the actual vapor-deposited film layer 28 and the design value is small.

[0149] Furthermore, the specific value of the second included angle θ2 can be set according to actual needs, for example, such as... Figure 18As shown, the evaporation angle α of the vapor deposition material ejected from the nozzle 35 can be limited by the angle limiting plate 36 to ensure that severe shading does not occur. In an exemplary embodiment, the first included angle θ1 can be set to be greater than or equal to (180-α) so that the second included angle θ2 is less than or equal to the evaporation angle α, thereby reducing or even eliminating the shading of the vapor deposition area by the metal pattern 241, increasing the area of ​​the vapor deposition film layer 38 deposited on the substrate 37 to be vapor deposited, and thus improving the flatness of the edge area of ​​the vapor deposition film layer 38. This improves the phenomenon that subsequent material films formed due to poor flatness of the film layer may break, but it is not limited to this, and the embodiments of the present invention do not specifically limit it.

[0150] Figure 23 A schematic diagram of the cross-sectional structure of another mask provided in an embodiment of the present invention is shown below. Figure 23 As shown, optionally, the surface of the second inorganic material layer 25 facing the second side 42 of the mask has a recessed structure 251.

[0151] Among them, such as Figure 15 and Figure 23 As shown, before forming the metal layer 23 on the second inorganic material layer 25, a recessed structure 251 is prepared on the surface of the second inorganic material layer 25 facing the second side 42, which can increase the adhesion between the metal layer 23 and the second inorganic material layer 25. In this way, when etching the metal layer 23 by chemical mechanical polishing (CMP), the risk of the metal layer 23 falling off the second inorganic material layer 25 can be reduced, which is conducive to the smooth progress of the etching process.

[0152] In addition, such as Figure 23 As shown, the surface of the second inorganic material layer 25 has a recessed structure 251, which can also increase the adhesion between the second frame layer 52 and the second inorganic material layer 25. This reduces the risk of the second frame layer 52 falling off the second inorganic material layer 25 when using a mask for vapor deposition, which is beneficial to the smooth progress of the etching process.

[0153] Optionally, the ratio between the depth of the recessed structure 251 and the thickness of the second inorganic material layer 25 is greater than or equal to 5%.

[0154] Among them, such as Figure 15 and Figure 23 As shown, by setting the depth of the recessed structure 251 to 5% or more of the thickness of the second inorganic material layer 25, it can be ensured that there is good adhesion between the metal layer 23 and the second inorganic material layer 25 when etching the metal layer 23. Thus, when etching the metal layer 23 by chemical mechanical polishing, the metal layer 23 can be prevented from falling off the second inorganic material layer 25, ensuring the smooth progress of the etching process.

[0155] In addition, such as Figure 23 As shown, the depth of the recessed structure 251 is 5% or more of the thickness of the second inorganic material layer 25, which can further increase the adhesion between the second frame layer 52 and the second inorganic material layer 25. This reduces the risk of the second frame layer 52 falling off the second inorganic material layer 25 when using a mask for vapor deposition, and facilitates the smooth progress of the etching process.

[0156] It should be noted that the specific value of the depth of the recessed structure 251 can be set according to actual needs. It can be understood that the larger the ratio between the depth of the recessed structure 251 and the thickness of the second inorganic material layer 25, the better the adhesion between the metal layer 23 / second frame layer 52 and the second inorganic material layer 25. This embodiment of the invention does not make specific limitations in this regard.

[0157] Optionally, the aperture of the through hole 242 between adjacent metal patterns 241 is less than or equal to 10 μm and greater than or equal to 0.5 μm.

[0158] Specifically, the mask structure provided in this embodiment of the invention can be fabricated using semiconductor processing technology, which helps to reduce the size of the via 242. The aperture of the via 242 formed using semiconductor processing technology can be less than or equal to 10 μm, achieving a smaller via size. This reduces the limitation imposed by the via size on the vapor deposition process, allowing for a smaller size of the organic light-emitting diode (OLED) formed from the organic light-emitting material layer of the display panel when using the mask for vapor deposition, thus meeting users' high-resolution requirements for the display panel. Simultaneously, the aperture of the via 242 formed using semiconductor processing technology can be greater than or equal to 0.5 μm, ensuring that the size of the OLED formed from the organic light-emitting material layer is not too small when using the mask for vapor deposition, thus guaranteeing the luminous brightness of the OLED.

[0159] Continue to refer to Figure 21 Optionally, the mask can be circular in shape.

[0160] Since the substrates used to fabricate semiconductor films, such as silicon wafers, are typically circular, in this embodiment, by setting the mask to a circular shape, a circular substrate can be directly used during mask fabrication, thereby reducing substrate cutting, simplifying process steps, and improving mask fabrication efficiency. However, this invention is not limited to this; the mask can also be square or other shapes.

[0161] Please refer to Figure 24 , Figure 24 A schematic diagram of the cross-sectional structure of another mask provided in an embodiment of the present invention is shown below. Figure 24As shown, the difference from the above implementation is that in the second region 32, the mask has a first frame layer 51 and a second frame layer 52, and no second inorganic material layer is disposed between the first frame layer 51 and the second frame layer 52. Referring to an embodiment of the mask forming method of the present invention, when the second inorganic material layer is not formed on the first surface 201 of the substrate 20, the final formed mask has no second inorganic material layer disposed between the first frame layer 51 and the second frame layer 52 in the second region 32.

[0162] Please refer to Figure 25 , Figure 25 A schematic diagram of the cross-sectional structure of another mask provided in an embodiment of the present invention is shown below. Figure 25 As shown, the difference from the above implementation is that a second material layer 25 is also provided on the side of the first frame layer 51 in the second region 32. Referring to the embodiment of the mask forming method of the present invention, when the second inorganic material layer 25 is only formed on the side 203 of the substrate 20, the second inorganic material layer 25 on the side 203 of the substrate 20 can be retained. Since the second inorganic material layer 25 formed on the side 203 of the substrate 20 does not affect the vapor deposition function of the mask, it can be retained. Thus, the formed mask is provided with a second material layer 25 on the side of the first frame layer 51, which can further increase the strength of the first frame layer 51.

[0163] Please refer to Figure 26 , Figure 26 A schematic diagram of the cross-sectional structure of another mask provided in an embodiment of the present invention is shown below. Figure 26 As shown, the difference from the above implementation is that, in the second region 32, a second material layer 25 is also provided on the side of the first frame layer 51, and a second material layer 25 is also provided between the first frame layer 51 and the second frame 51. Referring to an embodiment of the photomask forming method of the present invention, when the second inorganic material layer 25 is formed on the side 203 of the substrate 20 and the first pattern layer 22, the formed photomask also has a second material layer 25 on the side of the first frame layer 51, and a second material layer 25 is also provided between the first frame layer 51 and the second frame 52.

[0164] The mask provided by this invention is particularly suitable for use in the vapor deposition process of silicon-based OLED microdisplays. Silicon-based OLED microdisplays use single-crystal silicon wafers as substrates, and their pixel size can reach 1 / 10 of that of traditional displays. They have advantages such as low power consumption, small size, and high resolution, and have very high requirements for vapor deposition size and precision.

[0165] 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.

[0166] 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 manufacturing a photomask, characterized in that, The manufacturing method includes the following steps: A substrate is provided, the substrate including a first surface and a second surface disposed opposite to each other, and a side surface disposed between the first surface and the second surface; A first inorganic material layer is formed on the first surface of the substrate; The first inorganic material layer is etched to form a first pattern layer including a plurality of first patterns. The first pattern includes a first top surface away from the substrate and a first side surface connected to the first top surface. The first top surface and the first side surface have a first included angle. A second inorganic material layer is formed, the second inorganic material layer covering the side surface of the substrate; A metal layer is formed on the first patterned layer; The metal layer is etched to form a metal pattern layer comprising multiple metal patterns, each metal pattern being located between two adjacent first patterns; each metal pattern includes a second top surface away from the substrate and a second side surface connecting the second top surface, the second top surface and the second side surface having a second included angle, the second included angle being complementary to the first included angle; A third inorganic material layer is formed on the metal pattern layer; The substrate is etched from one side of the second surface of the substrate, retaining the substrate in the second region and removing the substrate in the first region; wherein, the second region is the peripheral region surrounding the first region; Remove the first pattern layer and the third inorganic material layer; The materials of the first inorganic material layer and the third inorganic material layer include at least one of silicon oxide, silicon nitride, and silicon oxynitride; The material of the second inorganic material layer includes at least one of silicon oxide, silicon nitride, and silicon oxynitride.

2. The method for manufacturing a photomask as described in claim 1, characterized in that, The second inorganic material layer also covers the first patterned layer and the first surface of the substrate exposed by the first patterned layer; After removing the first patterned layer and the third inorganic material layer, the second inorganic material layer, at least located in the first region, is removed.

3. The method for manufacturing a photomask as described in claim 1, characterized in that, The second inorganic material layer also covers the second surface of the substrate; Before etching the substrate from one side of the second surface of the substrate, the second inorganic material layer on the second surface of the substrate is etched, the second inorganic material layer in the first region is removed, and the second inorganic material layer in the second region is retained.

4. The method for manufacturing a photomask as described in claim 1, characterized in that, The substrate material includes at least one of silicon nitride, single-crystal silicon, germanium, silicon germanide, silicon carbide, gallium arsenide, and indium gallium nitride.

5. The method for manufacturing a photomask as described in claim 1, characterized in that, The base is circular or square in shape.

6. The method for manufacturing a photomask as described in claim 1, characterized in that, The material of the metal layer includes at least one of nickel, iron, titanium, tantalum, and tungsten, or an alloy containing at least one of nickel, iron, titanium, tantalum, and tungsten.

7. The method for manufacturing a photomask as described in claim 1, characterized in that, The thickness of the metal layer is less than or equal to 1 μm.

8. The method for manufacturing a photomask as described in claim 1, characterized in that, Before forming a metal layer on the first patterned layer, the method further includes forming a recessed structure on the surface of the second inorganic material layer.

9. The method for manufacturing a photomask as described in claim 8, characterized in that, The ratio between the depth of the recessed structure and the thickness of the second inorganic material layer is greater than or equal to 5%.

10. The method for manufacturing a photomask as described in claim 1, characterized in that, The first included angle is greater than or equal to 130 degrees, and the second included angle is less than or equal to 50 degrees.

11. The method for manufacturing a photomask as described in claim 1, characterized in that, The step of removing the first patterned layer and the third inorganic material layer includes: removing the first patterned layer and the third inorganic material layer by dilute hydrofluoric acid.

12. The method for manufacturing a photomask as described in claim 1, characterized in that, The etching of the substrate from the second side of the substrate includes etching the substrate with a potassium hydroxide solution.

13. A photomask, characterized in that, The mask includes a first side and a second side disposed opposite to each other, and the mask includes a first region and a second region surrounding the first region; In the first region, the mask includes multiple metal patterns, and through holes are provided between adjacent metal patterns; On the first side of the photomask, the metal pattern includes a second top surface and a second side surface connected to the second top surface, with a second included angle between the second top surface and the second side surface of the metal pattern; In the second region, the mask has a first frame layer and a second frame layer, wherein the first frame layer is made of a semiconductor material and the second frame layer is made of the same material as the metal pattern. A second inorganic material layer is further disposed between the first frame layer and the second frame layer; The material of the first framework layer includes at least one of silicon nitride, single-crystal silicon, germanium, silicon germanide, silicon carbide, gallium arsenide, and indium gallium nitride; The material of the second frame layer includes at least one of nickel, iron, titanium, tantalum, and tungsten, or an alloy containing at least one of nickel, iron, titanium, tantalum, and tungsten.

14. The photomask according to claim 13, characterized in that, The thickness of the metal pattern is less than or equal to 1 μm.

15. The photomask according to claim 13, characterized in that, The diameter of the through hole between adjacent metal patterns is less than or equal to 10 μm and greater than or equal to 0.5 μm.

16. The photomask according to claim 13, characterized in that, The second included angle is less than or equal to 50 degrees.

17. The photomask according to claim 13, characterized in that, Facing the second side of the mask, the surface of the second inorganic material layer has a recessed structure.

18. The photomask according to claim 17, characterized in that, The ratio between the depth of the recessed structure and the thickness of the second inorganic material layer is greater than or equal to 5%.

19. The photomask according to claim 13, characterized in that, The mask is circular or square in shape.

20. The photomask according to claim 13, characterized in that, The materials of the plurality of metal patterns include at least one of nickel, iron, titanium, tantalum, and tungsten, or an alloy containing at least one of nickel, iron, titanium, tantalum, and tungsten.

21. The photomask according to claim 13, characterized in that, A second inorganic material layer is also provided on the side of the first frame layer.

22. The photomask according to claim 13, characterized in that, When performing vapor deposition using the mask, the second top surface of the metal pattern is oriented toward the substrate to be vaporized, and the vapor deposition source is positioned at a distance from the substrate to be vaporized, with the second included angle being less than or equal to the evaporation angle. The evaporation angle is the maximum divergence angle of the vaporized vapor deposition material after it is ejected from the nozzle and limited by the angle limiting plate.

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