Mask structure

Abstract

The utility model provides a mask structure, the mask structure is made of monocrystalline silicon, the mask structure comprises a mask structure body and a plurality of openings, and the plurality of openings jointly form a pattern to be transferred; the mask structure is provided with a first surface and a second surface which are opposite, the multiple openings penetrate through the first surface and the second surface, the cross section of each opening is trapezoidal, the short edge of each opening is located on the first surface, the long edge of each opening is located on the second surface, and the short edge is used for facing a target workpiece. According to the mask structure provided by the invention, the size precision of the target pattern formed on the target workpiece is relatively high.

Description

Technical Field

[0001] The present application relates to the field of microelectronic processing technology, and in particular to a mask structure. Background Art

[0002] The mask structure is a plate-like member used for pattern transfer. The mask structure is widely used in microelectronics and optical fields such as screen printing, LCD, LED, OLED, etc.

[0003] The mask structure includes a mask structure body and a plurality of openings arranged on the mask structure body, and the plurality of openings together form a pattern to be transferred. The openings can usually be arranged on the mask structure body by the following methods: forming a plurality of openings on the mask structure body by mechanical processing methods such as laser cutting or wire cutting, and the heat generated during the mechanical processing may cause the mask structure body to deform, resulting in poor opening accuracy; forming a plurality of openings on the mask structure body by etching, and the etching process is difficult to accurately control, and double-sided etching may form a plurality of protrusions on the sides of the opening, resulting in poor opening accuracy; forming a plurality of openings on the mask structure body by electroforming, and the thickness of the mask structure formed by electroforming is relatively small, and it is easy to deform when the net is stretched, resulting in poor opening accuracy. In addition, the mask structure is usually made of metal materials, and during use, the net stretching stress may also cause the mask structure body to deform, resulting in the problem of poor opening accuracy.

[0004] The opening accuracy in the mask structure is poor, so that the accuracy of the pattern to be transferred formed by the multiple openings is poor, and thus the dimensional accuracy of the target pattern formed on the target workpiece is poor. Utility Model Content

[0005] The present application provides a mask structure. The target pattern formed on the target workpiece using the mask structure provided by the present application has high dimensional accuracy.

[0006] The present application provides a mask structure, the mask structure is made of single crystal silicon, the mask structure includes a mask structure body and a plurality of openings, and the plurality of openings together form a pattern to be transferred;

[0007] The mask structure has a first surface and a second surface relative to each other, and multiple openings penetrate the first surface and the second surface. The cross-sectional shape of each opening is trapezoidal, the short side of the opening is located on the first surface, the long side of the opening is located on the second surface, and the short side is used to face the target workpiece.

[0008] In a possible implementation manner, the mask structure provided by the present application has a first surface and a single crystal silicon <100> The crystal orientation is consistent;

[0009] The short side of the opening and the side of the opening form a first cone angle, and the angle of the first cone angle is greater than 45° and less than 90°.

[0010] In a possible implementation manner, in the mask structure provided by the present application, the thickness of the mask structure body is 20 μm-1000 μm.

[0011] In a possible implementation manner, in the mask structure provided in the present application, the flatness of the side edges of the opening is less than or equal to 5 μm.

[0012] In a possible implementation, the mask structure provided by the present application further includes a plurality of first alignment holes, which are evenly spaced along the periphery of the mask structure body and are used for aligning with the target workpiece.

[0013] The mask structure provided by the present application is provided with a mask structure body and a plurality of openings, and the plurality of openings together form a pattern to be transferred; the cross-sectional shape of each opening is a trapezoid, the long side of the opening is located on the first surface, and the short side of the opening is located on the second surface. In the process of coating the target workpiece, the short side faces the target workpiece, and the particles emitted by the emission source are deposited on the target workpiece after passing through the long side and the short side in sequence. The trapezoidal opening acts as a funnel and will not block the particles emitted by the emission source, so that the size of the target pattern formed on the target workpiece is the same as the size of the pattern to be transferred formed by the short side of the opening, and the size accuracy of the target pattern formed on the target workpiece is high. In addition, the mask structure is made of single crystal silicon, and the mask structure made of single crystal silicon has no ductility. Therefore, when the mask structure is stretched, the mask structure will not be deformed due to the stress of stretching the net, and thus, the opening will not be deformed, so that the size accuracy of the opening is high, and thus, the size accuracy of the target pattern formed on the target workpiece is also high. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A schematic structural diagram of a mask structure provided in an embodiment of the present application;

[0016] Figure 2 for Figure 1 Sectional view along line AA;

[0017] Figure 3 A diagram of the use state of the mask structure provided in the embodiment of the present application;

[0018] Figure 4 The process of manufacturing the mask structure provided in the embodiment of the present application Figure 1 ;

[0019] Figure 5 A schematic diagram of the structure of a master plate used to manufacture the mask structure provided in an embodiment of the present application;

[0020] Figure 6 for Figure 5 Side view of

[0021] Figure 7 is a schematic diagram of a structure after a mask layer is formed on a master;

[0022] Figure 8 It is a schematic diagram of the structure after a through hole communicating with the master is formed on the mask layer of the master;

[0023] Fig. 9 is a schematic diagram of the structure after an opening is formed on the master;

[0024] Fig.10 The process of manufacturing the mask structure provided in the embodiment of the present application Figure 2 ;

[0025] Fig.11 is a schematic diagram of the structure after photoresist is coated on the mask layer of the master;

[0026] Fig.12 A schematic diagram of the process of exposing and developing the photoresist on the mask layer;

[0027] Fig.13 A schematic diagram of the structure after removing the mask layer in the area to be etched;

[0028] Fig.14 A flow chart of a method for using a mask structure provided in an embodiment of the present application;

[0029] Fig.15 The graph is a thickness variation curve at the edge of a target pattern formed by vacuum coating using the mask structure provided by an embodiment of the present application.

[0030] Description of reference numerals:

[0031] 100-mask structure; 100a-first surface; 100b-second surface;

[0032] 110-mask structure body;

[0033] 120- opening; 121- long side; 122- short side; 123- side;

[0034] 130 - first alignment hole;

[0035] 200-target artifact;

[0036] 300-Emission source;

[0037] 400-motherboard; 400a-third surface; 400b-fourth surface;

[0038] 500-mask layer; 510-through hole;

[0039] 600-photoresist layer; 610-area to be etched;

[0040] 700-photolithography mask; 710-light transmission hole;

[0041] 800-UV beam;

[0042] 900-carrying platform;

[0043] α - first cone angle;

[0044] L-length direction;

[0045] W - width direction;

[0046] D-thickness direction;

[0047] L1-first length;

[0048] L2-second length;

[0049] L3-third length;

[0050] L4 - fourth length. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0054] The terms "first", "second", "third" (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0055] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or service tool that includes 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 process, method, product, or service tool.

[0056] The mask structure is a plate-like member used for pattern transfer. The mask structure is widely used in microelectronics and optical fields such as screen printing, LCD, LED, OLED, etc.

[0057] The mask structure includes a mask structure body and a plurality of openings arranged on the mask structure body. The plurality of openings together form a pattern to be transferred. The pattern to be transferred on the mask structure is transferred to the workpiece to be processed by sputtering, screen printing, etc. For the sake of convenience of description, the workpiece to be processed is called a target workpiece, and the pattern on the target workpiece is called a target pattern.

[0058] Generally, the following methods can be used to set the openings on the mask structure body: when the opening size is greater than 200 μm, multiple openings can be formed on the mask structure body by mechanical processing methods such as laser cutting or wire cutting. The mechanical processing process will generate heat, which will cause stress accumulation on the mask structure body, causing the mask structure body to deform, and the openings on the mask structure body will also deform, resulting in poor opening accuracy. In addition, the flatness of the side of the opening formed by the mechanical processing method is greater than 15 μm, and the side is relatively rough, which will also affect the accuracy of the opening.

[0059] When the opening size is 20μm-200μm, multiple openings are formed on the mask structure body by etching. The etching process is difficult to accurately control, and double-sided etching will form multiple protrusions on the sides of the openings. These protrusions will produce shadows during the pattern transfer process, affecting the uniformity and resolution of the pattern. In addition, the edges of the openings formed by etching are thinner, and the stress generated during the stretching process will cause the edges to warp, further reducing the accuracy of the openings.

[0060] When the opening size is less than 20 μm, multiple openings are formed on the mask structure body by electroforming. The mask structure formed by electroforming has a small thickness and is easily deformed when the mesh is stretched, resulting in poor opening accuracy.

[0061] In addition, the mask structure in the related art is usually made of metal material. Metal has ductility. During use, the tension stress will also cause the mask structure body to deform, resulting in poor opening accuracy.

[0062] Therefore, in the related art, the opening accuracy in the mask structure is poor, so that the accuracy of the pattern to be transferred formed by the multiple openings is poor, and thus the dimensional accuracy of the target pattern formed on the target workpiece is poor.

[0063] Based on this, the present application provides a mask structure, and the target pattern formed on the target workpiece using the mask structure provided by the present application has high dimensional accuracy.

[0064] Figure 1 A schematic structural diagram of a mask structure provided in an embodiment of the present application; Figure 2 for Figure 1 Sectional view along line AA. Figure 1 and Figure 2 As shown, the mask structure 100 provided in the present application is made of single crystal silicon, and the mask structure 100 includes a mask structure body 110 and a plurality of openings 120, and the plurality of openings 120 together form a pattern to be transferred; the mask structure 100 has a first surface 100a and a second surface 100b relative to each other, and the plurality of openings 120 all penetrate the first surface 100a and the second surface 100b, and the cross-sectional shape of each opening 120 is a trapezoid, and the long side 121 of the opening 120 is located on the first surface 100a, and the short side 122 of the opening 120 is located on the second surface 100b, and the short side 122 is used to face the target workpiece.

[0065] The mask structure 100 is generally a plate-shaped member used for pattern transfer. Figure 1 and Figure 2 In the illustrated embodiment, the length direction of the mask structure 100 is represented by L, the width direction of the mask structure 100 is represented by W, and the thickness direction of the mask structure 100 is represented by D.

[0066] The mask structure body 110 has a plurality of openings 120, and the layout of the openings 120 on the mask structure body 110 is arranged according to the specific shape and size of the pattern to be transferred. In this embodiment, the plurality of openings 120 extend along the length direction L of the mask structure 100 and are arranged at intervals along the width direction W of the mask structure 100. The plurality of openings 120 together form the pattern to be transferred.

[0067] For ease of description, two opposite surfaces of the mask structure 100 along the thickness direction D thereof are respectively referred to as a first surface 100 a and a second surface 100 b , and the openings 120 penetrate the mask structure body 110 along the thickness direction D of the mask structure 100 .

[0068] Next, the specific shape and formation method of the opening 120 will be described.

[0069] Please continue to see Figure 2 As shown, the cross section of the opening 120 is an isosceles trapezoid, and the cross-sectional shape of the isosceles trapezoid of the opening 120 is formed by utilizing the anisotropic etching characteristics of single-crystal silicon. Specifically, the mask structure 100 is a plate-like member made of a single-crystal silicon wafer, and the alkaline etching solution has different etching speeds for different crystal directions of single-crystal silicon. The etching solution can be one of KOH (potassium hydroxide), TMAH (tetramethylammonium hydroxide), EDP (ethylenediamine), NH2NH2 (hydrazine), NaOH (sodium hydroxide), and CsOH (cesium hydroxide). In this embodiment, KOH is used as the etching solution.

[0070] In this embodiment, the mask structure body 110 is placed in a KOH etching solution, and the KOH etching solution starts to etch from the first surface 100a. The etching speed of the etching solution along the width direction W of the mask structure 100 is greater than the etching speed along the thickness direction D of the mask structure 100. Therefore, when the etching solution penetrates the second surface 100b, the size of the opening 120 on the first surface 100a is greater than the size of the opening 120 on the second surface 100b, and an opening 120 with a cross-sectional shape of an isosceles trapezoid is formed on the mask structure body 110.

[0071] The side of the opening 120 on the first surface 100a is called a long side 121, the side of the opening on the second surface 100b is called a short side 122, and the side connecting the long side 121 and the short side 122 is called a side 123. Figure 2 In the figure, the long side 121 and the short side 122 of the opening 120 are schematically shown by dotted lines.

[0072] The process of pattern transfer using the mask structure 100 is described below by taking vacuum coating as an example.

[0073] Figure 3 This is a diagram of the use state of the mask structure provided in the embodiment of the present application. Figure 3 As shown, when the mask structure 100 is used for pattern transfer, the second surface 100 b faces the target workpiece 200 , that is, the short side 122 of the opening 120 faces the target workpiece 200 , and the emission source 300 is on one side of the first surface 100 a .

[0074] In the process of coating the target workpiece 200, the particles emitted by the emission source 300 are deposited on the target workpiece 200 after passing through the long side 121 and the short side 122 in sequence. It should be noted that the size of the pattern formed on the target workpiece 200 is the same as the size of the short side 122. Since the size of the emission source 300 is difficult to be completely the same as the size of the mask structure 100, the emission source 300 will not face every opening 120, and there is an angle between the emission source 300 and most of the openings 120.

[0075] Since the cross-section of the opening 120 is a trapezoid, and the long side 121 is facing the emission source 300, therefore, at the opening 120 that is not completely aligned with the emission source 300, the trapezoidal opening 120 acts as a funnel and does not block the particles emitted by the emission source 300, so that the size of the target pattern formed on the target workpiece 200 is the same as the size of the pattern to be transferred formed by the short side 122 of the opening 120, and the size accuracy of the target pattern formed on the target workpiece 200 is high.

[0076] In addition, the mask structure 100 is made of single crystal silicon, and the mask structure 100 made of single crystal silicon has no ductility. Therefore, when the mask structure 100 is used for coating, there is no need to stretch the mesh. The mask structure 100 will not be deformed due to the stretching stress, and the opening 120 will not be deformed. This makes the size accuracy of the opening 120 higher, and the accuracy of the pattern to be transferred formed by multiple openings 120 is higher. Therefore, the size accuracy of the target pattern formed on the target workpiece 200 is also higher.

[0077] The mask structure 100 provided in the present application is provided with a mask structure body 110 and a plurality of openings 120, and the plurality of openings 120 together form a pattern to be transferred; the cross-sectional shape of each opening 120 is a trapezoid, the long side 121 of the opening 120 is located on the first surface 100a, and the short side 122 of the opening 120 is located on the second surface 100b. In the process of coating the target workpiece 200, the short side 122 faces the target workpiece 200, and the particles emitted by the emission source 300 are deposited on the target workpiece 200 after passing through the long side 121 and the short side 122 in sequence. The trapezoidal opening 120 acts as a funnel and will not block the particles emitted by the emission source 300, so that the size of the target pattern formed on the target workpiece 200 is the same as the size of the pattern to be transferred formed by the short side 122 of the opening 120, and the size accuracy of the target pattern formed on the target workpiece 200 is high. In addition, the mask structure 100 is made of single crystal silicon, and the mask structure 100 made of single crystal silicon has no ductility. Therefore, when the mask structure 100 is stretched, the mask structure 100 will not be deformed due to the stretching stress. Therefore, the opening 120 will not be deformed either, so that the dimensional accuracy of the opening 120 is relatively high. Therefore, the dimensional accuracy of the target pattern formed on the target workpiece 200 is also relatively high.

[0078] Please continue to see Figure 2 As shown, the first surface 100a and the single crystal silicon <100> The crystal directions are consistent; the short side 122 of the opening 120 and the side 123 of the opening 120 form a first cone angle α, and the angle of the first cone angle α is greater than 45° and less than 90°.

[0079] Specifically, the mask structure 100 is usually processed using a single crystal silicon wafer as the raw material. Commonly used single crystal silicon wafers include <100> Crystal direction, <110> Crystal orientation and <111> Crystal direction. KOH solution has different corrosion rates on different crystal directions. <111> The etching rate of the crystal direction is the smallest. <100> Crystal orientation can be <111> The crystal directions form an acute angle. <110> Crystal orientation can be <111> The crystal directions form a right angle.

[0080] Therefore, in this embodiment, using <100> The mask structure 100 is made of single crystal silicon with a crystal orientation, and the mask structure body 110 is etched in a KOH solution. <111> A first taper angle α is formed between the side edge 123 formed by the crystal orientation and the first surface 100 a (or the second surface 100 b ).

[0081] The angle of the first cone angle α can vary between 45° and 90° depending on the concentration of the etching solution, the temperature during the etching process, and the etching time. In this embodiment, the concentration of the etching solution is 32%, the temperature of the etching solution during the etching process is 85°C, the etching time is 240 minutes, and the angle of the first cone angle α obtained by etching is 54.7°.

[0082] Please continue to see Figure 2 As shown, the thickness of the mask structure body 110 is 20 μm-1000 μm.

[0083] The thickness of commonly used single crystal silicon wafers ranges from 20 μm to 1000 μm. For example, the thickness of single crystal silicon wafers can be 100 μm, 200 μm, 279 μm, 300 μm, 400 μm, 500 μm, 525 μm, 600 μm, 675 μm, 700 μm, 725 μm, 775 μm, 1000 μm, etc. The smaller the thickness of the single crystal silicon wafer, the higher the cost. In this embodiment, when the thickness of the single crystal silicon wafer is less than 20 μm, the strength of the mask structure 100 will be reduced. When the thickness of the single crystal silicon wafer is greater than 1000 μm, the etching time will be increased and the production efficiency will be reduced. Therefore, a single crystal silicon wafer with an existing thickness between 20 μm and 1000 μm is usually selected to make the mask structure 100.

[0084] In this embodiment, the flatness of the side edge 123 of the opening 120 is less than or equal to 5 μm.

[0085] The flatness of the surface obtained by anisotropically etching the single crystal silicon is relatively small, so the side 123 is relatively smooth, and the protrusions on the side 123 produce less obstruction during pattern transfer, so that the size accuracy of the target pattern on the target workpiece is relatively high.

[0086] Please continue to see Figure 1 As shown, the mask structure 100 further includes a plurality of first alignment holes 130 . The first alignment holes 130 are evenly spaced along the circumference of the mask structure body 110 . The first alignment holes 130 are used to align with the target workpiece 200 .

[0087] Specifically, the first alignment holes 130 are evenly spaced along the periphery of the mask structure body 110, thereby avoiding the area of ​​the pattern to be transferred and achieving better alignment. The shape of the first alignment holes 130 can be any one of circular / rectangular / triangular / cross.

[0088] The target workpiece 200 also has second alignment holes (not shown) arranged in one-to-one correspondence with the first alignment holes 130. The mask structure 100 and the target workpiece 200 can be aligned by aligning the first alignment holes 130 with the second alignment holes.

[0089] Figure 4 The process of manufacturing the mask structure provided in the embodiment of the present application Figure 1 . See Figure 4As shown, the present application also provides a method for manufacturing a mask structure, which is used to manufacture the mask structure 100 provided in the above embodiment, wherein the specific structure of the mask structure 100 has been described in detail in the above embodiment and will not be repeated here.

[0090] The method for manufacturing the mask structure includes:

[0091] S101 , forming a mask layer 500 on the third surface 400 a and the fourth surface 400 b of the master 400 .

[0092] Specifically, Figure 5 A schematic diagram of the structure of a master plate used to manufacture the mask structure provided in an embodiment of the present application; Figure 6 for Figure 5 Side view of the . Figure 5 and Figure 6 As shown, the single crystal silicon wafer for making the mask structure 100 is called a motherboard 400. The motherboard 400 has a flat third surface 400a and a fourth surface 400b. It should be noted that the third surface 400a of the motherboard 400 is the first surface 100a of the mask structure 100, and the fourth surface of the motherboard 400 is the second surface 100b of the mask structure 100. The distinction between the third surface 400a and the first surface 100a and the distinction between the fourth surface 400b and the second surface 100b is only for the convenience of description.

[0093] Figure 7 Schematic diagram of the structure after the mask layer is formed on the master. Figure 7 As shown, a mask layer 500 is formed on both the third surface 400a and the fourth surface 400b of the motherboard 400. The mask layer 500 can be a film layer formed of silicon dioxide, silicon nitride, silicon carbide, or metal Au, Ag, Cr.

[0094] The mask layer 500 can be covered on the third surface 400a and the fourth surface 400b by plasma enhanced chemical vapor deposition (PECVD) technology. PECVD technology is to ionize the gas containing the atoms of the film components by microwave or radio frequency, and form plasma locally, so as to deposit the mask layer 500 on the master 400. The mask layer 500 formed by PECVD technology has the advantages of fast deposition rate, good film quality, less pinholes, and not easy to crack, so as to facilitate the subsequent process. The thickness of the mask layer 500 is usually less than or equal to 500um.

[0095] S102 , forming a through hole 510 communicating with the motherboard 400 on the mask layer 500 on the third surface 400 a .

[0096] Specifically, Figure 8 Schematic diagram of the structure after forming a through hole connected to the master on the mask layer of the master. Figure 8 As shown, according to the specific shape of the pattern to be transferred, part of the mask layer 500 on the third surface 400a is removed, and these areas after the mask layer 500 is removed form through holes 510 connected to the third surface 400a of the master 400. Figure 8 In FIG. 5 , the through hole 510 is schematically shown by a dotted line.

[0097] S103 , anisotropically etching the motherboard 400 through the through hole 510 using an etching solution to form an opening 120 with a trapezoidal cross section.

[0098] Specifically, Fig. 9 Schematic diagram of the structure after the opening is formed on the master. Fig. 9 As shown, the motherboard 400 in the through hole 510 area is anisotropically etched by an etching solution. The etching solution can be one of KOH, TMAH (tetramethylammonium hydroxide), EDP (ethylenediamine), hydrazine, sodium hydroxide, and cesium hydroxide. In this embodiment, KOH is used as the etching solution. When the concentration of KOH is too high, the etching rate is high, but the surface formed after etching is also rough; when the concentration of KOH is too low, the etching rate is too slow, affecting the processing efficiency. Therefore, the weight percentage of the KOH solution is usually selected between 10% and 50%.

[0099] It should be noted that the size of the through hole 510 is consistent with the size of the long side of the opening 120 .

[0100] S104 , removing the mask layer 500 on the third surface 400 a and the fourth surface 400 b to form a mask structure 100 .

[0101] After peeling off the remaining mask layer on the third surface 400 a and the mask layer 500 on the fourth surface 400 b , the mask structure 100 provided in the embodiment of the present application can be obtained.

[0102] Next, a specific process of forming the through hole 510 communicating with the motherboard 400 on the third surface 400 a is described.

[0103] Fig.10 The process of manufacturing the mask structure provided in the embodiment of the present application Figure 2 ; Fig.11 is a schematic diagram of the structure after photoresist is coated on the mask layer of the master; Fig.12 A schematic diagram of the process of exposing and developing the photoresist on the mask layer; Fig.13 Schematic diagram of the structure after removing the mask layer in the area to be etched. Figures 10 to 13As shown, forming a through hole connected to the master on the mask layer 500 on the third surface 400a includes:

[0104] S1021, coating a photoresist layer 600 on the mask layer 500 on the third surface 400a;

[0105] For details, please refer to Fig.11 As shown, a photoresist layer 600 is uniformly coated on the mask layer 500 on the third surface 400 a of the master 400 .

[0106] S1022, exposing and developing the photoresist layer 600 to expose the to-be-etched area 610;

[0107] For details, please refer to Fig.12 As shown, a photolithography mask 700 is disposed on one side of the third surface 400 a , wherein the photolithography mask 700 has a light-transmitting hole 710 , and the size of the light-transmitting hole 710 is the same as the size of the long side of the opening 120 .

[0108] The ultraviolet light beam 800 passes through the light-transmitting hole 710 to expose and develop the photoresist, exposing the area to be etched 610 in the photoresist layer 600. Fig.12 In the figure, the light-transmitting hole 710 and the area to be etched 610 are schematically shown by dotted lines.

[0109] S1023 , removing the mask layer 500 in the to-be-etched area 610 to form a through hole 510 communicating with the motherboard 400 .

[0110] For details, please refer to Fig.13 As shown, the mask layer 500 at a position corresponding to the to-be-etched area 610 is removed by chemical etching, and a through hole 510 communicating with the motherboard 400 can be formed on the mask layer 500 .

[0111] S1024 , stripping off the remaining photoresist layer 600 on the mask layer 500 .

[0112] The photoresist layer 600 is dissolved by a photoresist stripping solution to remove the remaining photoresist layer 600 .

[0113] Thus, the formation Figure 8 The motherboard 400 shown in FIG. 1 has a mask layer 500 on both the third surface 400a and the fourth surface 400b, wherein the mask layer 500 on the third surface 400a has a through hole 510 connected to the motherboard 400. After anisotropic etching, a Fig. 9 The opening 120 is shown in FIG.

[0114] Please continue to see Fig. 9 and Fig.13As shown, the size of the area to be etched 610 is the same as the size of the through hole 510 and is the same as the size of the long side of the opening; the length of the long side of the opening is:

[0115] L3=L4+2b*coty

[0116] Wherein, L4 is the size of the short side 122 of the opening 120 , b is the thickness of the motherboard 400 , and y is the angle of the first cone angle α.

[0117] Specifically, the length of the area to be etched 610 is used to schematically illustrate the size of the area to be etched, which is called the first length L1; the length of the through hole 510 is used to schematically illustrate the size of the through hole 510, which is called the second length L2; the length of the long side 121 is used to schematically illustrate the size of the long side 121, which is called the third length L3; the length of the short side 122 is used to schematically illustrate the size of the short side 122, which is called the fourth length L4. The first length L1 and the second length L2 are the same as the third length L3.

[0118] The fourth length L4 is the size of the pattern to be transferred, that is, the size of the target pattern. The size of the target pattern is a known value. The thickness b of the master 400 is the thickness of the single crystal silicon wafer. The first cone angle α can be estimated based on the composition of the etching solution and the etching time. The cross section of the opening 120 is an isosceles trapezoid, so the third length L3 of the long side 121 of the opening 120 can be calculated by the following formula:

[0119] L3=L4+2b*coty

[0120] The first length L1 and the second length L2 are all the same as the third length L3 , thereby obtaining the sizes of the to-be-etched region 610 and the through hole 510 .

[0121] Therefore, the size of the area to be etched 610 can be accurately calculated according to the size of the target pattern, so that the size accuracy of the opening 120 is high, and the size accuracy of the pattern to be transferred formed by the opening 120 is high. Therefore, the target pattern formed on the target workpiece 200 also has high size accuracy.

[0122] In order to increase the etching rate, anisotropic etching solution is used to pass through the through hole 510 to anisotropically etch the motherboard 400 to form an opening 120 with a trapezoidal cross-section. The process also includes: heating and stirring the anisotropic etching solution, wherein the heating temperature is 65°-90°, and the stirring method is magnetic rotation stirring or ultrasonic stirring.

[0123] Heating the KOH solution can increase the anisotropic etching rate, but if the heating temperature is too high, the etching rate will be too high, making the etched surface rougher. Therefore, the temperature during the etching process is kept within the range of 65°-90°. During the etching process, stirring the KOH solution with magnetic rotation stirring or ultrasonic stirring can make the KOH more uniform, so that the rate of the entire etching process is more uniform.

[0124] After the etching is completed, the mask layer 500 on the third surface 400 a and the fourth surface 400 b of the master 400 needs to be removed.

[0125] In this embodiment, removing the mask layer 500 on the third surface 400a and the fourth surface 400b to form the mask structure 100 includes: removing the mask layer on the third surface 400a and the fourth surface 400b by dry etching or wet etching.

[0126] In wet etching, the mask layer 500 is stripped by chemical reaction between the etching solution and the mask layer 500; in dry etching, the etchant is plasma, and the plasma reacts with the mask layer to form volatile substances, or the plasma directly bombards the mask layer 500 to strip the mask layer. According to actual process requirements, one of dry etching and wet etching can be selected to remove the mask layer on the third surface 400a and the fourth surface 400b.

[0127] Fig.14 A flowchart of a method for using a mask structure provided in an embodiment of the present application. Fig.14 As shown, the present application also provides a method for using the mask structure, including:

[0128] S201, mounting the mask structure 100 on the carrier platform 900;

[0129] The carrier platform 900 is used to install the mask structure 100 . The mask structure 100 can be installed on the carrier platform 900 by fasteners. The mask structure 100 can also be clamped on the carrier platform 900 .

[0130] S202, disposing the target workpiece 200 toward the second surface 100b of the mask structure 100, so that the target workpiece 200 is parallel to the second surface 100b;

[0131] The target workpiece 200 is also fixed by the carrier 900. The target workpiece 200 can be mounted on the carrier 900 by fasteners, and the target workpiece 200 can also be clamped on the carrier 900. Figure 3As shown, the target workpiece 200 needs to be disposed on one side of the second surface 100 b and the target workpiece 200 needs to remain parallel to the mask structure 100 , thereby ensuring that the target pattern on the target workpiece 200 is consistent in size with the pattern to be transferred formed by the short side 122 of the opening 120 .

[0132] S203 , disposing the emission source 300 on one side of the first surface 100 a of the mask structure 100 .

[0133] The particles emitted by the emission source 300 are sequentially deposited on the target workpiece 200 via the long sides 121 and the short sides 122 to form a target pattern on the target workpiece 200 .

[0134] In this embodiment, the target workpiece 200 is disposed toward the second surface 100 b of the mask structure 100 so that the target workpiece 200 is parallel to the second surface 100 b and the method also includes: aligning the mask structure 100 with the target workpiece 200 through the first alignment hole 130 on the mask structure 100 .

[0135] The target workpiece 200 also has second alignment holes arranged in one-to-one correspondence with the first alignment holes 130. The mask structure 100 and the target workpiece 200 can be aligned by aligning the first alignment holes 130 with the second alignment holes.

[0136] In other embodiments, the target workpiece 200 and the mask structure 100 may be aligned by other alignment methods.

[0137] In this embodiment, the gap between the target workpiece 200 and the second surface 100 b of the mask structure 100 is 0-1000 μm.

[0138] When the mask structure 100 is used for screen printing, the target workpiece 200 can be set close to the second surface 100b. When the mask structure 100 is used for vacuum coating, there can be a certain gap between the target workpiece 200 and the second surface 100b. When the gap size is too large, due to the projection effect, the size of the target pattern will be larger than the size of the pattern to be transferred, so the gap is usually less than or equal to 1000μm.

[0139] It should be noted that the number of points for measuring the gap must be greater than or equal to three, and the three adjacent points cannot be located on the same straight line, so that the measured gap is accurate.

[0140] Fig.15 The thickness variation curve at the edge of the target pattern formed by vacuum coating using the mask structure provided by the embodiment of the present application is shown in FIG. Fig.15In the figure, the horizontal axis represents the width of the edge area of ​​the target pattern on the target workpiece 200, in μm, wherein the difference between the dotted line x1 and the dotted line x2 is the width of the edge area of ​​the target pattern; the vertical axis represents the thickness of the target pattern on the target workpiece 200, in nm. It can be seen that the width of the edge area of ​​the target pattern is approximately 2.4 μm, the width of the edge area is small, and the target pattern has a higher resolution.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A mask structure, characterized in that: The mask structure is made of single crystal silicon, and the mask structure comprises a mask structure body and a plurality of openings, wherein the plurality of openings together form a pattern to be transferred; The mask structure has a first surface and a second surface relative to each other, and the plurality of openings penetrate the first surface and the second surface. The cross-sectional shape of each of the openings is a trapezoid, the short side of the opening is located on the first surface, the long side of the opening is located on the second surface, and the short side is used to face the target workpiece.

2. The mask structure according to claim 1, characterized in that: The first surface and the single crystal silicon <100> The crystal orientation is consistent; The short side of the opening and the side of the opening form a first cone angle, and the angle of the first cone angle is greater than 45° and less than 90°.

3. The mask structure according to claim 1, characterized in that: The thickness of the mask structure body is 20 μm-1000 μm.

4. The mask structure according to claim 1, characterized in that: The flatness of the side of the opening is less than or equal to 5 μm.

5. The mask structure according to any one of claims 1 to 4, characterized in that: The mask structure further includes a plurality of first alignment holes, which are evenly spaced along the periphery of the mask structure body, and are used for aligning with a target workpiece.

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