Substrate etching method for making mask

Abstract

A substrate etching method for manufacturing a mask is provided, which may include the following steps: preparing a substrate; providing a first coating layer, which may be optically transparent, may cover a covered portion of the substrate, and may expose an exposed portion of the substrate; forming a scattering layer between the first coating layer and the substrate; and removing the exposed portion of the substrate to form a mask hole.

Description

[0001] This patent application claims the priority benefit of Korean Patent Application No. 10-2018-0139333 filed on November 13, 2018 in the Korean Intellectual Property Office; the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION The present invention relates to a method of etching a substrate for manufacturing a mask. Background Art

[0003] Generally, an organic light emitting diode (OLED) display device includes an organic light emitting element for emitting light through an electrical excitation process. The organic light emitting element generally has a multilayer structure including an emission layer (EML), an electron transport layer (ETL), and a hole transport layer (HTL). In some cases, the organic light emitting element may further include an electron injection layer (EIL) and a hole injection layer (HIL).

[0004] Organic light emitting elements are generally manufactured by a deposition process. A fine metal mask (FMM) is used in the deposition process. The fine metal mask includes a mask pattern formed by a chemical etching process, a plating-based patterning process, and / or a laser etching process. Summary of the invention

[0005] Embodiments may relate to a method of producing a mask for optimizing the yield of organic light emitting element manufacturing and / or display device manufacturing.

[0006] According to an embodiment, a method for etching a substrate may include: preparing a target substrate, which includes a plurality of hole areas and a blocking area surrounding the hole areas when viewed in a plan view; forming a first coating layer having an optically transparent property on the target substrate; forming a scattering layer between the first coating layer overlapping the blocking area in a plan view and the target substrate; and etching the hole area of ​​the target substrate to form a plurality of mask holes.

[0007] In an embodiment, the method may further include patterning the first coating layer after the step of forming the first coating layer. In a plan view, the patterned first coating layer may overlap the barrier region and may not overlap the hole region.

[0008] In an embodiment, the step of forming the scattering layer may include generating particles on the target substrate by irradiating the target substrate with a first laser, and then removing the particles from the hole region. The particles on the blocking region may be covered by the first coating layer.

[0009] In an embodiment, the step of generating particles on the target substrate may be performed by irradiating the first laser onto the entire areas of the hole area and the blocking area.

[0010] In an embodiment, the step of generating particles on the target substrate may be performed in such a way that a focus of the first laser is located between the first coating layer and the target substrate.

[0011] In an embodiment, the first laser may have a diameter of about 2 μm or less.

[0012] In an embodiment, the first coating layer may have a thickness of about 1.5 μm or more.

[0013] In an embodiment, the step of forming the mask hole may include irradiating the target substrate with a second laser.

[0014] In an embodiment, the second laser may have a diameter larger than a diameter of the first laser.

[0015] In an embodiment, a diameter of the second laser may be greater than or equal to about 10 μm.

[0016] In an embodiment, the first laser may have a focal length that is shorter than a focal length of the second laser.

[0017] In an embodiment, the first laser and the second laser may have the same wavelength band.

[0018] In an embodiment, the method may further include removing the first coating layer and the scattering layer after the step of forming the mask hole in the target substrate.

[0019] In an embodiment, the first coating layer may include a negative photoresist.

[0020] In an embodiment, the first coating layer may be provided in the form of a tape and may be disposed on a target substrate.

[0021] In an embodiment, the target substrate may include a metallic material.

[0022] In an embodiment, the method may further include forming a second coating layer on the scattering layer and the target substrate after the step of forming the scattering layer. The second coating layer may have an optical transparency lower than that of the first coating layer.

[0023] In an embodiment, the method may further include removing the first coating layer, the scattering layer, and the second coating layer after the step of forming the mask hole.

[0024] In an embodiment, the second coating layer may include a positive photoresist.

[0025] According to an embodiment, a method for etching a substrate may include: preparing a target substrate, the target substrate including a plurality of hole regions and a blocking region surrounding the hole regions when viewed in a plan view; forming a first coating layer on the target substrate, the first coating layer having an optically transparent property and overlapping with the blocking region but not overlapping with the hole region in a plan view; irradiating a first laser to form a scattering layer between the first coating layer overlapping with the blocking region in a plan view and the target substrate; and irradiating a second laser to etch the hole region of the target substrate, the second laser having a diameter larger than that of the first laser.

[0026] An embodiment may relate to a method for manufacturing a mask, which may include the following steps: preparing a substrate; providing a first coating layer, which may be optically transparent, may cover a covered portion of the substrate, and may expose an exposed portion of the substrate; forming a scattering layer between the first coating layer and the covered portion of the substrate; and removing the exposed portion of the substrate to form a mask hole.

[0027] The method may further include the steps of: preparing a material layer; and patterning the material layer to form a first coating layer.

[0028] The step of forming the scattering layer may include generating particles on the substrate by irradiating the substrate with a first laser. The material of the particles may be the same as the material of the substrate. The particles may include a first particle group and a second particle group. The first particle group may be positioned on a covered portion of the substrate. The second particle group may be positioned on an exposed portion of the substrate. The step of forming the scattering layer may also include removing the second particle group. The first particle group may be covered by a first coating. The scattering layer may include the first particle group.

[0029] The step of generating particles on the substrate may include irradiating a first laser onto both the covered portion of the substrate and the exposed portion of the substrate.

[0030] The step of generating particles on the substrate may include positioning a focal point of the first laser between the first coating and the substrate.

[0031] The first laser may have a diameter of 2 μm or less.

[0032] The first coating layer may have a thickness of 1.5 μm or more.

[0033] The step of removing the exposed portion of the substrate may include irradiating the substrate with a second laser.

[0034] The diameter of the second laser light may be larger than the diameter of the first laser light.

[0035] The diameter of the second laser may be greater than or equal to 10 μm.

[0036] The focal length of the first laser may be shorter than the focal length of the second laser.

[0037] The first laser light and the second laser light may have the same wavelength band.

[0038] The method may further include removing the first coating layer and the scattering layer after the step of removing the exposed portion of the substrate.

[0039] The first coating may include a negative photoresist.

[0040] Before the first coating is disposed on the substrate, the first coating may include an opening. The opening may expose an exposed portion of the substrate.

[0041] The substrate may include a metallic material.

[0042] The method may further include forming a second coating layer on the scattering layer and the substrate after the step of forming the scattering layer. The optical transparency of the second coating layer may be lower than the optical transparency of the first coating layer.

[0043] The method may further include removing the first coating layer, the scattering layer, and the second coating layer after the step of removing the exposed portion of the substrate.

[0044] The second coating may include a positive photoresist.

[0045] Embodiments may relate to a method for manufacturing a mask. The method may include the following steps: preparing a substrate; providing a first coating on the substrate, the first coating being optically transparent, covering a covered portion of the substrate, and exposing an exposed portion of the substrate; irradiating a first laser on the substrate to form a scattering layer between the first coating and the substrate; and irradiating a second laser to etch the exposed portion of the substrate. The diameter of the second laser may be larger than that of the first laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is an exploded perspective view illustrating a structure of a mask assembly according to an embodiment.

[0047] Figure 2 is a flowchart illustrating a method of etching a substrate according to an embodiment.

[0048] Figure 3 is a perspective view showing a target substrate according to an embodiment.

[0049] Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10 is a cross-sectional view illustrating a structure formed in a process of etching a substrate according to an embodiment.

[0050] Fig.11 , Fig.12 and Fig.13 is a cross-sectional view illustrating a process of etching a substrate according to an embodiment.

[0051] These drawings are intended to illustrate the general characteristics of methods, structures and / or materials used in certain example embodiments and are intended to supplement the written description provided below. These drawings should not be construed as limiting the example embodiments. In the drawings, relative thicknesses and positions may be reduced or exaggerated for clarity. Similar or identical reference numerals may indicate similar or identical elements or features. DETAILED DESCRIPTION

[0052] Example embodiments are described with reference to the accompanying drawings. Actual embodiments may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. In the accompanying drawings, the thickness of layers and regions may be exaggerated for clarity. The same reference numerals may represent the same elements.

[0053] Although the terms "first", "second", etc. can be used to describe various elements, these elements should not be limited by these terms. These terms can be used to distinguish an element from another element. Without departing from the teaching of one or more embodiments, the first element can be named as the second element. Describing an element as a "first" element does not require or imply the presence of a second element or other elements. The terms "first", "second", etc. can be used to distinguish elements of different categories or groups. For simplicity, the terms "first", "second", etc. can represent "first type (or first group)", "second type (or second group)", etc. respectively.

[0054] When a first element is referred to as being "on", "connected" or "coupled" to a second element, the first element may be directly on, directly connected or directly coupled to the second element, or one or more intervening elements may be present between the first and second elements. When a first element is referred to as being "directly on", "directly connected" or "directly coupled" to a second element, there are no intervening elements (except environmental elements such as air) between the first and second elements.

[0055] The term "and / or" may indicate any and all combinations of one or more related items.

[0056] For ease of description, spatially relative terms such as "under", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to another element or feature. It will be understood that the spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, the elements described as "below" or "beneath" other elements or features would then be oriented as "above" the other elements or features. Thus, the exemplary term "under" can include both above and below orientations. The device can be positioned otherwise (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein interpreted accordingly.

[0057] The terms used herein are for the purpose of describing specific embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a", "one", and "the" may also include plural forms. The terms "include", "comprises", and / or variations thereof may indicate the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, and / or components.

[0058] Example embodiments are described herein with reference to cross-sectional illustrations which are schematic diagrams of idealized structures. For example, variations in the shapes of the illustrations resulting from, for example, manufacturing techniques and / or tolerances are to be expected. Thus, example embodiments should not be construed as limited to the specific shapes of the regions illustrated herein but are to include deviations in shape resulting from, for example, manufacturing.

[0059] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those of ordinary skill in the art. Unless explicitly defined herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

[0060] Figure 1 is an exploded perspective view showing a mask assembly structure MAS according to an embodiment.

[0061] The mask assembly structure MAS may be used in a process of depositing a deposition material on a process target object. In an embodiment, the mask assembly structure MAS may be used in an organic material deposition process for manufacturing an organic light emitting element (not shown), and the process target object may be a base substrate of an organic light emitting display panel.

[0062] The mask assembly structure MAS may include a supporting frame FRM and a plurality of deposition masks MSK.

[0063] The support frame FRM may have an annular or ring shape when viewed in a plan view along the third direction DR3. In an embodiment, the support frame FRM may have a rectangular structure whose long sides are parallel to the first direction DR1 and whose short sides are parallel to the second direction DR2 and / or perpendicular to the first direction DR1.

[0064] In a plan view, the opening MOP may be in a central region of the support frame FRM. The opening MOP may have a rectangular shape whose long sides are parallel to the first direction DR1 and whose short sides are parallel to the second direction DR2. The length of the opening MOP in the first direction DR1 and the second direction DR2 may be determined according to the number or size of the mask MSK.

[0065] The masks MSK may be mounted on the supporting frame FRM. The masks MSK may be arranged in the first direction DR1. Each of the masks MSK may extend in the second direction DR2. The array of the masks MSK may be exposed through the opening MOP of the supporting frame FRM.

[0066] Opposite ends of each of the masks MSK in the second direction DR2 may overlap with and be mounted on the supporting frame FRM. The opposite ends of the mask MSK may be coupled to the supporting frame FRM through an adhesive process (eg, a welding process).

[0067] A plurality of mask holes MH may be defined in each of the masks MSK. The mask holes MH may be arranged in a matrix / array in each of the masks MSK. The mask holes MH may be exposed through the openings MOP of the support frame FRM. Therefore, during the deposition process, a deposition material (not shown) may pass through the openings MOP and the mask holes MH.

[0068] The mask holes MH may define a deposition area on a process target object (not shown). The size, shape, and number of patterns deposited on the process target object in a deposition process may depend on the size, shape, and number of the mask holes MH.

[0069] Figure 2 is a flow chart illustrating steps in a method of etching a substrate for forming a mask according to an embodiment.

[0070] Figure 3 is a perspective view showing a substrate according to an embodiment. Figures 4 to 10 is a cross-sectional view illustrating a structure formed in a process of etching a substrate for forming a mask according to an embodiment. Figures 4 to 10 Each figure shows a Figure 3 A vertical cross-sectional view taken along line II'.

[0071] As in Figure 3 As shown in FIG. 1 , a target substrate SUB may be prepared (at step S1). In an embodiment, the target substrate SUB may be a substrate for one or more of the aforementioned masks (eg, see Figure 1 Therefore, the etching process of the target substrate SUB can produce one or more masks MSK or a mother mask substrate.

[0072] The target substrate SUB may be formed of or include a metal material. In an embodiment, the target substrate SUB may be formed of or include a Fe-Ni alloy. A suitable material of the target substrate SUB may be selected for producing the deposition mask MSK.

[0073] The target substrate SUB may include a plurality of hole areas HA (or portions to be exposed or substantially removed) and barrier areas CA (portions to be covered or substantially retained). The hole areas HA may be spaced apart from each other and may be arranged in a matrix / array in a plan view. The hole areas HA may be portions in which the substrate is to be formed. Figure 1 The blocking area CA may surround the hole area HA in a plan view. After the etching process, the blocking area CA may surround the hole area HA. Figure 1 The mask hole MH.

[0074] Then, as in Figure 4 As shown in , a first coating layer 10 (or first coating 10) can be formed on a target substrate SUB (at step S2). The first coating layer 10 can be optically transparent. For example, a material layer for forming the first coating layer 10 can be prepared, and then the material layer can be patterned to form the first coating layer 10.

[0075] The first coating layer 10 may be formed of or include an organic material that allows for an easy subsequent patterning process. In an embodiment, the first coating layer 10 may include a negative photoresist. In an embodiment, the first coating layer 10 may include an inorganic material.

[0076] The first coating layer 10 may include a negative photoresist coated on the target substrate SUB through a spin coating process or a screen printing process.

[0077] The first coating layer 10 may be / include a film attached to the target substrate SUB through an adhesive material.

[0078] Then, as in Figure 5As shown in FIG. 1 , the first coating layer 10 may be patterned (at step S3 ). The first coating layer 10 may include a negative photoresist and may be patterned by a photolithography process.

[0079] After the patterning step (step S3), the remaining first coating layer 10 may overlap the barrier area CA but not the hole area HA. Figure 5 As shown in FIG. 1 , the top surface of the target substrate SUB corresponding to the hole area HA may be exposed through the first coating layer 10 .

[0080] When the first coating layer 10 is provided in the form of a film, a patterning step (at step S3) may be performed in advance before the first coating layer 10 is provided on the target substrate SUB. After the patterning step (at step S3) has been performed on the first coating layer 10, the patterned first coating layer 10 may be provided on the target substrate SUB.

[0081] Afterwards, as in Figure 6 As shown in, the target substrate SUB can be irradiated with a first laser LS1. The focus of the first laser LS1 can be positioned between the target substrate SUB and the first coating layer 10. The first laser LS1 can be generated by a laser generator and can be irradiated onto the target substrate SUB. The laser generator can be two-dimensionally movable in a plane parallel to the top surface of the target substrate SUB.

[0082] Since the first coating layer 10 is optically transparent, the first laser LS1 may pass through the first coating layer 10. According to an embodiment, the thickness T1 of the first coating layer 10 is greater than a certain value so that the first laser LS1 may pass through the first coating layer 10 without seriously damaging the first coating layer 10.

[0083] The thickness T1 of the first coating layer 10 may be determined based on the depth of focus (DOF) of the first laser LS1. Therefore, the thickness T1 of the first coating layer 10 is greater than half of the depth of focus (DOF) so that the first coating layer 10 is not seriously damaged even when irradiated with the first laser LS1.

[0084] The depth of focus (DOF) of the first laser LS1 may be changed according to the focal length Z. In an embodiment, the depth of focus (DOF) of the first laser LS1 may be changed according to the focal length Z. 0 2 / λ gives the focal length Z, where λ is the wavelength of the first laser LS1, w 0 is the diameter of the first laser LS1.

[0085] In the embodiment, the diameter w of the first laser LS1 is 0 The thickness T1 of the first coating layer 10 may be equal to or less than about 2 μm, and may be equal to or greater than about 1.5 μm.

[0086] When the first laser LS1 is irradiated onto the target substrate SUB, particles PT may be generated on the top surface of the target substrate SUB. The material of the particles PT is the same as that of the target substrate SUB. After the first laser LS1 has been irradiated onto the entire top surface of the target substrate SUB, the particles PT may be dispersed throughout the entire top surface of the target substrate SUB.

[0087] The particles PT generated on the barrier area CA may be disposed between the target substrate SUB and the first coating layer 10. The particles PT generated on the hole area HA may be disposed on the top surface of the target substrate SUB and may be exposed through the opening of the first coating layer 10.

[0088] In an embodiment, the first laser LS1 may be locally irradiated onto the top surface of the blocking area CA of the target substrate SUB without being irradiated onto the hole area HA. ​​As a result, particles PT may be generated on the top surface of a local area (eg, the blocking area CA) of the target substrate SUB.

[0089] Then, refer to Figure 7 , the first laser LS1 may be irradiated to remove the particles PT from the hole area HA. ​​The particles PT may be removed by a suction unit (not shown) or an air blowing unit (not shown). The suction unit or the air blowing unit may change the air pressure on the top surface of the target substrate SUB and may cause the movement of the exposed particles PT on the hole area HA. ​​Therefore, the exposed particles PT may be removed from the top surface of the hole area HA of the target substrate SUB.

[0090] The particles PT generated on the blocking area CA may be disposed between the top surface of the target substrate SUB and the first coating layer 10 and may be covered by the first coating layer 10. Therefore, during the process of removing the particles PT, only the exposed particles PT may be removed from the hole area HA, and the covered particles PT under the first coating layer 10 may not be removed from the blocking area CA. The particles PT remaining on the blocking area CA may form the scattering layer 20 or the light scattering layer 20 (in the Figure 2 Step S4).

[0091] Then, as in Figure 8 As shown in FIG. 1 , the second laser LS2 may be irradiated onto the target substrate SUB to etch the target substrate SUB (in Figure 2 Step S5). The hole area HA of the target substrate SUB may be etched by the second laser LS2.

[0092] When the second laser LS2 is irradiated onto the blocking area CA of the target substrate SUB, the second laser LS2 may be scattered or irregularly reflected by the scattering layer 20. Therefore, even if the second laser LS2 is irradiated onto the blocking area CA, the energy of the second laser LS2 is not significantly transferred to the target substrate SUB. Therefore, the blocking area CA is not significantly etched by the second laser LS2.

[0093] The focal length of the second laser LS2 may be longer than the focal length of the first laser LS1. Therefore, the diameter of the second laser LS2 may be greater than the diameter of the first laser LS1. 0 In an embodiment, the diameter of the second laser LS2 may be equal to or greater than about 10 μm. The second laser LS2 may have the same wavelength range as that of the first laser LS1.

[0094] As in Fig. 9 As shown in , as a result of etching of the hole area HA, a mask hole MH may be formed in the target substrate SUB. The mask hole MH may correspond to the hole area HA in a one-to-one correspondence. The mask hole MH may penetrate the target substrate SUB.

[0095] Then, as in Fig.10 As shown in , the first coating layer 10 and the scattering layer 20 may be removed. In an embodiment, the first coating layer 10 and the scattering layer 20 may be removed by a developing process or a chemical etching process. In an embodiment, the first coating layer 10 may be removed first, and then the scattering layer 20 may be removed by further performing a suction process or an air blast process.

[0096] The remaining target substrate SUB from which the first coating layer 10 and the scattering layer 20 are removed may be used as a reference Figure 1 Describe the mask MSK.

[0097] If the first coating layer 10 and the scattering layer 20 are not implemented, the misalignment between the second laser LS2 and the target substrate SUB during the movement of the second laser LS2 relative to the target substrate SUB may cause a significant change in the position of the mask hole MH in the mask MSK. Specifically, if the number of mask holes MH per unit area of ​​the target substrate SUB increases, the misalignment problem may become so serious that it is unacceptable. In contrast, according to an embodiment, a scattering layer 20 may be formed on the blocking area CA using the first laser LS1 passing through the first coating layer 10, and the scattering layer 20 may cause irregular reflections on the blocking area CA, which prevents the blocking area CA from being etched by the second laser LS2. Therefore, it is possible to ensure the accuracy of the position of the mask hole MH in the target substrate SUB. According to an embodiment, because the first coating layer 10 can be patterned using a photolithography process that allows high-resolution patterning, it is possible to effectively prevent the misalignment problem even when the number of mask holes MH per unit area of ​​the target substrate SUB is large.

[0098] Figures 11 to 13 is a cross-sectional view illustrating a structure formed in a process of etching a substrate according to an embodiment.

[0099] For the sake of brevity of description, previously described elements, features, or steps may be identified by similar or identical reference numerals, and the related description may not be repeated.

[0100] Figures 11 to 13 shows that it is possible to form a reference Figure 7 The process of the scattering layer 20 described in Figure 2 The structure is executed after step S4).

[0101] Reference Fig.11 After the step of forming the scattering layer 20, a second coating layer 30 (or second coating layer 30) may be formed on the first coating layer 10 and the target substrate SUB. The second coating layer 30 may cover the top surface of the first coating layer 10 on the blocking area CA and the exposed top surface portion of the target substrate SUB on the hole area HA.

[0102] The second coating layer 30 may have an optical transparency lower than that of the first coating layer 10. For example, the second coating layer 30 may be opaque.

[0103] The second coating layer 30 may be formed of or include an organic material. In an embodiment, the second coating layer 30 may include a positive photoresist.

[0104] The etching rate of the second coating layer 30 corresponding to the second laser LS2 may be higher than the etching rate of the target substrate SUB corresponding to the second laser LS2. In an embodiment, the etching rate of the second coating layer 30 corresponding to the second laser LS2 may be about 20 times higher than the etching rate of the target substrate SUB corresponding to the second laser LS2.

[0105] Then, as in Fig.12 As shown in FIG. 1 , the second laser LS2 may be irradiated onto the target substrate SUB to etch the target substrate SUB. The second laser LS2 may etch the target substrate SUB and the second coating layer 30 at the hole area HA.

[0106] As portions of the target substrate SUB and the second coating layer 30 at the hole area HA are etched and removed, a mask hole MH′ may be formed in the target substrate SUB and the second coating layer 30, as shown in FIG. Fig.13 The mask hole MH′ may penetrate the target substrate SUB and the second coating layer 30 .

[0107] Then, the remaining first coating layer 10, the remaining scattering layer 20, and the remaining second coating layer 30 (remaining on the target substrate SUB) may be removed. As a result, the remaining target substrate SUB may be Fig.10 The target substrates are essentially the same.

[0108] Generally, when a target substrate SUB including a metal material is etched by the second laser LS2, metal particles may be generated. If the first coating layer 10 or the second coating layer 30 is not provided, a large amount of particles may be directly deposited on the top surface of the target substrate SUB. If the particles are larger than a specific size, the particles may not be sufficiently removed by a particle removal process (not shown), and the incomplete removal of the particles may affect subsequent processes. According to an embodiment, even when the target substrate SUB is etched by the second laser LS2, particles PT' may be generated on the top surface of the second coating layer 30 without directly generating the particles PT' on the top surface of the target substrate SUB, such as in Fig.13 As shown in . Therefore, it is possible to sufficiently remove the unnecessary particles PT'.

[0109] According to the embodiments, due to the improved mask accuracy, it is possible to increase the yield of organic light emitting element manufacturing and / or display device manufacturing.

[0110] Although example embodiments have been described, changes in form and detail may be made without departing from the scope of the claims.

Claims

1. A substrate etching method for manufacturing a mask, the substrate etching method comprising the following steps: Prepare the substrate; providing a first coating layer, the first coating layer being optically transparent, covering the covered portion of the substrate and exposing the exposed portion of the substrate; forming a scattering layer between the first coating layer and the covered portion of the substrate by irradiating the substrate with a first laser; as well as removing the exposed portion of the substrate to form a mask hole, The scattering layer includes particles generated when the substrate is irradiated by the first laser.

2. The substrate etching method according to claim 1, further comprising the steps of: preparing material layers; and The material layer is patterned to form the first coating layer.

3. The substrate etching method according to claim 2, wherein: The material of the particles is the same as the material of the substrate, wherein the particles include a first particle group and a second particle group, wherein the first particle group is positioned on the covered portion of the substrate, and wherein the second particle group is positioned on the exposed portion of the substrate, The step of forming the scattering layer further includes: removing the second particle group, wherein the first particle group is covered by the first coating layer, and wherein the scattering layer comprises the first particle group.

4. The substrate etching method according to claim 3, wherein: The step of generating the particles on the substrate includes irradiating the first laser onto both the covered portion of the substrate and the exposed portion of the substrate.

5. The substrate etching method according to claim 3, wherein: The step of generating the particles on the substrate includes positioning a focus of the first laser between the first coating and the substrate.

6. The substrate etching method according to claim 3, wherein: The first laser has a diameter of 2 µm or less.

7. The substrate etching method according to claim 3, wherein: The first coating layer has a thickness of 1.5 μm or more.

8. The substrate etching method according to claim 3, wherein: The step of removing the exposed portion of the substrate includes irradiating the substrate with a second laser.

9. The substrate etching method according to claim 8, wherein: The diameter of the second laser light is larger than the diameter of the first laser light.

10. The substrate etching method according to claim 9, wherein: The diameter of the second laser is greater than or equal to 10 μm.

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