Photolithography mask, photolithography mask manufacturing device and photolithography mask manufacturing method

Abstract

The invention provides a photomask, a photomask manufacturing device and a photomask manufacturing method. The photolithography mask comprises a substrate, an outer frame and a dielectric layer, the substrate is provided with a first substrate surface and a second substrate surface which are oppositely arranged and are parallel to each other, and a photoetching pattern layer is arranged on the first substrate surface; the outer frame is provided with a first open end and a second open end which are opposite, and the second open end is fixedly connected with the first substrate surface. The dielectric layer is of a transparent rigid film structure formed by injecting a molten filling material into a containing cavity defined by the substrate and the outer frame and solidifying the molten filling material. According to the technical scheme, the dielectric layer is of the rigid thin film structure, the dielectric layer is attached to the substrate, and air does not exist between the dielectric layer and the substrate, so that the dielectric layer can be effectively prevented from deforming due to air pressure change in the photoetching process, and meanwhile, photoetching patterns can be prevented from being polluted by impurities; therefore, the photoetching pattern can be accurately projected to the surface of the wafer or the substrate.

Description

Technical Field

[0001] The present application relates to the field of semiconductor processing, and in particular, to a photolithography plate, a photolithography plate manufacturing device and a photolithography plate manufacturing method. Background Art

[0002] A photomask, also known as a mask or a photomask, is a graphic master used in the photolithography process. Its main function is to accurately copy the preset photolithography pattern on its surface onto a wafer or substrate. Usually, a photomask is formed by an opaque light-shielding film on a transparent substrate to form a mask pattern structure. Its working principle is: using the mask pattern structure to selectively illuminate the photoresist layer on the wafer or substrate, so that the chemical properties of the photoresist change, and then developing and removing the corresponding photoresist to obtain a patterned photoresist layer; the patterned photoresist layer can be used as a mask to facilitate the subsequent process of selectively etching, injecting or depositing the wafer or substrate, thereby obtaining a patterned wafer or substrate. Photomasks have been widely used in fields involving photolithography, such as integrated circuits, flat panel displays, printed circuit boards, and micro-electromechanical systems.

[0003] In actual production, dust or other impurities are easily adhered to the photomask, which may pollute the photolithography pattern and affect the subsequent pattern replication effect on the wafer or substrate. In response to this problem, a common solution is to set a dustproof film on the surface of the photomask. However, the dustproof film commonly used in the prior art is only a layer of flexible light-transmitting film, which is easy to deform or break, and cannot be cleaned by common cleaning methods such as high-pressure airflow, which is not convenient for maintenance. In addition, since there is usually a certain distance between the surface of the existing dustproof film and the photomask, and a large amount of heat is generated in the photolithography process, the air between the dustproof film and the photomask will expand or contract under the influence of the ambient temperature, causing the dustproof film to deform. Therefore, the outer frame of the dustproof film is usually provided with pores to balance the internal and external air pressure, but it is difficult to fundamentally solve the problem of dustproof film deformation, and the gas exchange process may also introduce dust or impurities such as sulfate and ammonium in the environment between the dustproof film and the photomask, thereby causing the surface of the photomask or dustproof film to be contaminated, which has a negative impact on the final photolithography effect. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a photolithography plate, a photolithography plate manufacturing device and a photolithography plate manufacturing method. The dielectric layer of the photolithography plate is a rigid film structure, and the dielectric layer is attached to the substrate without air between the two, so the dielectric layer will not be deformed due to changes in air pressure during the photolithography process, which can ensure that the photolithography pattern is accurately projected onto the surface of the wafer or substrate.

[0005] In the first aspect, the present application provides a photolithography plate, comprising a substrate, an outer frame and a dielectric layer. The substrate has a first substrate surface and a second substrate surface that are arranged oppositely and parallel to each other, and a photolithography pattern layer is arranged on the first substrate surface. The outer frame has a first opening end and a second opening end that are opposite to each other, and the second opening end is fixedly connected to the first substrate surface. The dielectric layer is a transparent rigid film structure formed by injecting a molten filler into a receiving cavity surrounded by the substrate and the outer frame and solidifying it.

[0006] In an implementable solution, the second open end of the outer frame is provided with a fitting portion, and the end surface area of ​​the fitting portion is larger than the end surface area of ​​the second open end.

[0007] In an implementable solution, a first auxiliary bonding structure is disposed on the bonding portion surface, and a second auxiliary bonding structure is disposed on the first substrate surface. The first auxiliary bonding structure cooperates with the second auxiliary bonding structure to form a fixed connection between the bonding portion and the first substrate surface.

[0008] In an implementable solution, the transmittance of the dielectric layer is greater than or equal to 99.5%.

[0009] In an implementable solution, a sealing strip is provided on the outer side of the connection between the fitting portion of the outer frame and the first substrate surface.

[0010] In a second aspect, the present application also provides a photolithography plate manufacturing device, including a vacuum device, an injection device and a rotating table. The vacuum device includes a vacuum chamber and an exhaust device connected to the inside of the vacuum chamber, and the internal temperature of the vacuum chamber is adjustable. The injection port of the injection device is arranged at the top of the inner wall of the vacuum chamber, and is used to inject molten filling material into the inside of the vacuum chamber. The rotating table is arranged at the bottom surface of the inside of the vacuum chamber.

[0011] In a third aspect, the present application also provides a method for manufacturing a photolithography plate, comprising the following steps:

[0012] S1, preparing a substrate and an outer frame, wherein the substrate has a first substrate surface and a second substrate surface opposite to each other, and a photolithography pattern layer is disposed on the first substrate surface; and the outer frame has a first opening end and a second opening end opposite to each other;

[0013] S2, applying adhesive to the first substrate surface and the second open end of the outer frame respectively, and attaching the second open end to the first substrate surface, so that a receiving cavity with one side open is formed between the substrate and the outer frame;

[0014] S3, injecting molten filling material into the containing cavity to form a molten filling layer;

[0015] S4, cooling the photoresist to solidify the filling layer;

[0016] S5. Grind the upper surface of the filling layer to form a dielectric layer.

[0017] In one feasible solution, steps S3 - S4 are performed in a vacuum environment.

[0018] In one feasible solution, the filler used to form the filling layer is a transparent thermosetting material.

[0019] In an practicable solution, in step S3, the photoresist is kept rotating around a vertical axis, and then a molten filler is injected into the receiving cavity between the substrate and the outer frame, so that the filler is spin-coated on the surface of the substrate to form a filling layer.

[0020] Compared with the prior art, the beneficial effects of this application include at least:

[0021] The present application provides a photolithography plate, whose dielectric layer is a rigid film structure, and the dielectric layer is bonded to the substrate, and there is no air between the two. Therefore, in the photolithography process, the dielectric layer will not be deformed due to changes in air pressure, and the photolithography pattern can be accurately projected onto the surface of the wafer or substrate. In addition, since the dielectric layer is bonded to the substrate, dust in the external environment and impurities such as sulfate and ammonium cannot contact the photolithography pattern, which helps to ensure that the photolithography pattern is not contaminated. Furthermore, since the dielectric layer is a rigid film structure, the first dielectric surface can be easily cleaned, for example, a high-pressure nitrogen cleaning method can be selected, thereby greatly reducing the complexity of maintaining the photolithography plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A cross-sectional view of a first photomask according to an embodiment of the present application;

[0024] Figure 2 for Figure 1 Top view of the medium reticle;

[0025] Figure 3 A cross-sectional view of a second photomask according to an embodiment of the present application;

[0026] Figure 4 A third cross-sectional view of a photomask according to an embodiment of the present application;

[0027] Figure 5 is a schematic diagram of a photolithography plate manufacturing device according to an embodiment of the present application;

[0028] Figure 6 This is the overall flow chart of the photolithography production process;

[0029] Figure 7 A schematic diagram for preparing to bond the outer frame and substrate;

[0030] Figure 8 is a schematic diagram of injecting filler into the surface of a substrate in a vacuum chamber;

[0031] Fig. 9 A schematic diagram of completing the injection of filler material and forming a filling layer in a vacuum chamber;

[0032] Fig.10 Schematic diagram of preparing a photoresist for grinding;

[0033] Fig.11 Schematic diagram of the photoresist after grinding.

[0034] In the figure: 1, substrate; 2, dielectric layer; 3, outer frame; 4, accommodating cavity; 5, filling layer; 7, injection device; 8, grinding device; 101, first substrate surface; 102, second substrate surface; 103, photolithography pattern layer; 201, first dielectric surface; 202, second dielectric surface; 301, first opening end; 302, second opening end; 303, bonding part; 501, filling material; 601, vacuum chamber; 602, exhaust device; 603, rotating table; 604, temperature control device; 901, first auxiliary bonding structure; 902, second auxiliary bonding structure; 903, sealing strip. DETAILED DESCRIPTION

[0035] 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, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0037] like Figure 1-Figure 4As shown, the present application provides a photolithography plate, including a substrate 1, a dielectric layer 2 and an outer frame 3. The substrate 1 has a first substrate surface 101 and a second substrate surface 102 that are arranged oppositely and parallel to each other, and a photolithography pattern layer 103 is arranged on the first substrate surface 101. The outer frame 3 has a first opening end 301 and a second opening end 302 that are opposite to each other, and the second opening end 302 is fixedly connected to the first substrate surface 101. The dielectric layer 2 has a first dielectric surface 201 and a second dielectric surface 202 that are arranged oppositely and parallel to each other, wherein the second dielectric surface 202 is in contact with the first substrate surface 101. The dielectric layer 2 is a transparent rigid film structure formed by injecting a molten filler into a receiving cavity surrounded by the substrate 1 and the outer frame 3 and curing it. The first dielectric surface 201 is parallel to the first substrate surface 101, so that during the photolithography process, light can directly pass through the dielectric layer 2 without refraction, thereby ensuring that the photolithography pattern is accurately projected at the target position.

[0038] In actual production, a transparent thermosetting filler can be injected into the accommodating cavity surrounded by the substrate 1 and the outer frame 3 in a molten state, and the dielectric layer 2 can be formed after the filler is solidified. The thermosetting fillers that can be used include low-melting-point quartz glass, nitrocellulose resin, and polytetrafluoroethylene, etc., and the specific materials are not limited here. It should be noted that the dielectric layer 2 will fill the gaps between the photolithographic patterns, so that the dielectric layer 2, the photolithographic pattern 3 and the substrate 1 are in close contact, and there is no gap between the three. The dielectric layer 2 should also have excellent light transmission performance so that the photolithographic pattern can be projected to the target position clearly and accurately. Preferably, a material with a transmittance greater than or equal to 99.5% can be selected to make the dielectric layer 2. The outer frame 2 can be made of a metal material that is resistant to high temperatures and is not easily affected by temperature and expands or contracts. For example, a titanium alloy can be selected. The specific materials of the dielectric layer 2 and the outer frame 2 are not too limited here. The photolithographic pattern layer 103 can be made of chromium or molybdenum silicide, and the photolithographic pattern is formed on the photolithographic pattern layer 103 by etching. In actual work, the photolithography pattern layer 103 can be completely located inside the outer frame 3, such as Figure 1 It is also possible to make only the lithography pattern portion of the lithography pattern layer 103 located inside the outer frame 3, such as Figure 3 As shown, at this time, the outer frame 3 is in contact with the non-photolithographic pattern portion of the photolithographic pattern layer 103, which helps to reduce the overall volume of the dustproof film assembly, reduce the weight of the photolithography plate and reduce the production cost.

[0039] In the photolithography process, the photomask is affected by light and generates high temperature. Since the dielectric layer 2 is bonded to the substrate 1, there is no air between the two, and the dielectric layer 2 is a rigid film structure, the dielectric layer 2 will not be deformed due to changes in air pressure, which can ensure that the photolithography pattern is accurately projected onto the surface of the wafer or substrate. In addition, since the dielectric layer 2 is bonded to the substrate 1, dust in the external environment and impurities such as sulfate and ammonium cannot contact the photolithography pattern, which helps to ensure that the photolithography pattern is not contaminated. Furthermore, after a period of use, the first dielectric surface 201 of the dielectric layer 2 may be contaminated by various impurities in the external environment. Since the dielectric layer 2 is a rigid film structure, the first dielectric surface 201 can be easily cleaned, for example, a high-pressure nitrogen cleaning method can be selected, thereby greatly reducing the complexity of maintaining the photomask.

[0040] In one embodiment, if Figure 1-Figure 4 As shown, the second open end 302 of the outer frame 3 can be provided with a fitting portion 303, and the end surface area of ​​the fitting portion 303 is larger than the end surface area of ​​the second open end 302. After the fitting portion 303 is provided, on the one hand, the fitting area between the outer frame 3 and the substrate 1 can be increased, making the combination of the two tighter and stronger, and on the other hand, it also helps to improve the airtightness between the substrate 1 and the outer frame 3, and better prevent the outside air from entering between the dustproof film assembly and the substrate 1. Specifically, the width of the fitting portion 303 can be arbitrarily set between 5mm-25mm, and preferably, the width of the fitting portion 303 can be set to 10mm or 15mm.

[0041] In one embodiment, if Figure 4 As shown, a first auxiliary bonding structure 901 may be provided on the surface of the bonding portion 303, and a second auxiliary bonding structure 902 may be provided on the first substrate surface 101. The first auxiliary bonding structure 901 cooperates with the second auxiliary bonding structure 902 to form a fixed connection between the bonding portion 303 and the first substrate surface 101. Figure 4 As shown, the first auxiliary fitting structure 901 can be a convex structure, and the second auxiliary fitting structure 902 can be a groove structure matched therewith. The first auxiliary fitting structure 901 can also be set as a groove structure, and the second auxiliary fitting structure 902 can be set as a convex structure matched therewith. On the one hand, the first auxiliary fitting structure 901 and the second auxiliary fitting structure 902 help to make the connection between the substrate 1 and the outer frame 3 tighter and prevent the substrate 1 and the outer frame 3 from being misaligned. On the other hand, it also helps to improve the airtightness between the substrate 1 and the outer frame 3, and better prevent the outside air from entering between the dustproof film assembly and the substrate 1.

[0042] In one embodiment, if Figure 4As shown, a sealing strip 903 may be provided outside the connection between the fitting portion 303 of the outer frame 3 and the first substrate surface 101. The sealing strip 903 may be made of a high temperature resistant sealing material, such as polyurethane, chloroprene rubber or silicone rubber. The provision of the sealing strip 903 helps prevent outside air from entering between the dustproof film assembly and the substrate 1, further reducing the possibility of contamination of the photolithography pattern.

[0043] like Figure 5 As shown, the present application also provides a photolithography plate manufacturing device, including a vacuum device and an injection device 7. The vacuum device includes a vacuum chamber 601 and an exhaust device 602 connected to the inside of the vacuum chamber 601. The injection port of the injection device 7 is arranged at the top of the inner wall of the vacuum chamber 601, and is used to inject molten filling material into the vacuum chamber 601. When in use, the air pressure in the vacuum chamber 601 is maintained at a preset pressure value by means of the exhaust device 602. Preferably, the air pressure value in the vacuum chamber 601 can be maintained at 5-1000mTorr (i.e. 0.67-133Pa).

[0044] A rotating table 603 may also be provided on the bottom surface of the vacuum chamber 601. The rotating table has a table top and a rotating bracket that can be used to carry the photolithography to be processed. The rotating bracket can drive the table top to rotate around the vertical direction. A limiting structure (not shown in the figure) may also be provided above the table top of the rotating table 603. The limiting structure may limit the substrate 1 of the photolithography carried above it to prevent the photolithography from being displaced or even thrown off the rotating table during rotation, thereby ensuring that the photolithography production process can be carried out smoothly. The limiting device may be a raised structure provided above the table top of the rotating table 603, and its shape matches the shape of the substrate 1 of the photolithography. In addition, a temperature control device 604 may also be provided inside the vacuum chamber 601. The temperature control device 604 may use a thermocouple temperature control device or a semiconductor temperature control device to achieve temperature regulation, and the specific type is not limited here. When in use, the temperature control device 604 may detect and adjust the temperature inside the vacuum chamber 601 in real time according to a preset program.

[0045] The present application also provides a method for producing a photolithography plate. Figure 6-Figure 11 As shown, the photolithography production method includes the following steps:

[0046] S1, such as Figure 7 As shown, a substrate and an outer frame are prepared, wherein the substrate has a first substrate surface and a second substrate surface opposite to each other, and a photolithography pattern layer is arranged on the first substrate surface; and the outer frame has a first opening end and a second opening end opposite to each other;

[0047] S2, applying adhesive to the first substrate surface and the second open end of the outer frame respectively, and attaching the second open end to the first substrate surface, so that a receiving cavity with one side open is formed between the substrate and the outer frame;

[0048] S3, such as Figure 8 As shown, a molten filling material is injected into the containing cavity to form a molten filling layer;

[0049] S4, such as Fig. 9 As shown, the photoresist is cooled to solidify the filling layer;

[0050] S5, such as Figure 10-11 As shown, the upper surface of the filling layer is ground to form a dielectric layer.

[0051] In step S2, the adhesive used can be epoxy resin, acrylic glue or silicone, and the specific type is not limited here. When executing steps S3-S4, the photoresist can be placed in a vacuum environment as a whole. On the one hand, since the filler needs to be injected in a molten state, the materials of the filler, substrate, outer frame and photolithography pattern layer may undergo oxidation reactions at high temperatures, which may cause the photoresist production to fail in severe cases, and the vacuum environment can effectively avoid this problem; on the other hand, when the filling layer is formed in a vacuum environment, bubbles can be effectively avoided between the filling layer and the substrate, outer frame or photolithography pattern layer. In addition, during the cooling and curing process of the filling layer, the vacuum environment also helps to prevent the filling layer from being affected by the airflow, so that the texture of the solidified dielectric layer is uniform, thereby ensuring the accuracy of the photolithography pattern projection. Preferably, the air pressure value of the vacuum environment can be maintained in the range of 5-1000mTorr (i.e., 0.67-133Pa).

[0052] In step S3, the photomask can be kept rotating around the vertical axis, and then a molten filler is injected into the accommodating cavity between the substrate and the outer frame, so that the filler is spin-coated on the surface of the substrate to form a filling layer. In addition, the filler used to form the filling layer in step S3 is a transparent thermosetting material, and specifically, low-melting-point quartz glass, nitrocellulose resin or polytetrafluoroethylene can be selected, which is not limited here.

[0053] In step S4, a temperature control device can be used to monitor the temperature of the photoresist in real time, so that the photoresist is always cooled slowly at a uniform and stable cooling rate to avoid abrupt temperature changes, thereby preventing deformation or cracks in the filling layer. Preferably, the temperature of the photoresist can be evenly reduced to 20-25°C within 5-10 minutes.

[0054] In step S5, the upper surface of the filling layer is preferably ground by chemical mechanical polishing (CMP). During the grinding process, the upper part of the outer frame can be ground together so that the upper part of the outer frame is flush with the upper surface of the filling layer, so as to ensure that the edge of the dielectric layer can be fully ground, and the process complexity can also be reduced. After step S5, sulfuric acid and hydrogen peroxide solution can be used to clean the surface of the filling layer to remove stains and impurities.

[0055] During the process of carrying out steps S1 to S5, it should be ensured that the photomask is in a dust-free environment, and the cleanliness standard thereof is preferably ISO grade 5 or higher, so as to prevent the photomask from being contaminated.

[0056] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photolithography plate, characterized in that: include: A substrate (1) having a first substrate surface (101) and a second substrate surface (102) which are arranged opposite to and parallel to each other, wherein a photolithography pattern layer (103) is arranged on the first substrate surface (101); An outer frame (3) having a first opening end (301) and a second opening end (302) opposite to each other, wherein the second opening end (302) is fixedly connected to the first substrate surface (101); The dielectric layer (2) is a transparent rigid film structure formed by injecting molten filling material into a receiving cavity surrounded by the substrate (1) and the outer frame (3) and solidifying the molten filling material.

2. The photolithography plate according to claim 1, characterized in that: The second open end (302) of the outer frame (3) is provided with a fitting portion (303), and the end surface area of ​​the fitting portion (303) is larger than the end surface area of ​​the second open end (302).

3. The photolithography plate according to claim 2, characterized in that: The surface of the bonding portion (303) is provided with a first auxiliary bonding structure (901), and the first substrate surface (101) is provided with a second auxiliary bonding structure (902); The first auxiliary bonding structure (901) cooperates with the second auxiliary bonding structure (902) to form a fixed connection between the bonding portion (303) and the first substrate surface (101).

4. The photolithography plate according to claim 1, characterized in that: The transmittance of the medium layer (2) is greater than or equal to 99.5%.

5. The photolithography plate according to claim 2, characterized in that: A sealing strip (903) is provided on the outside of the connection between the fitting portion (303) of the outer frame (3) and the first substrate surface (101).

6. A photolithography plate manufacturing device, characterized in that: include: A vacuum device, comprising a vacuum chamber (601) and an exhaust device (602) connected to the interior of the vacuum chamber (601), wherein the internal temperature of the vacuum chamber (601) is adjustable; An injection device (7), the injection port of which is arranged at the top of the inner wall of the vacuum chamber (601), and is used to inject molten filling material into the interior of the vacuum chamber (601); The rotating table (603) is arranged at the bottom surface of the vacuum chamber (601).

7. A method for producing a photolithography plate, characterized in that: include: S1, preparing a substrate and an outer frame, wherein the substrate has a first substrate surface and a second substrate surface opposite to each other, and a photolithography pattern layer is disposed on the first substrate surface; The outer frame has a first open end and a second open end opposite to each other; S2, applying adhesive to the first substrate surface and the second open end of the outer frame respectively, and attaching the second open end to the first substrate surface, so that a receiving cavity with one side open is formed between the substrate and the outer frame; S3, injecting molten filling material into the containing cavity to form a molten filling layer; S4, cooling the photoresist to solidify the filling layer; S5. Grind the upper surface of the filling layer to form a dielectric layer.

8. The method for producing a photolithography plate according to claim 7, characterized in that: Steps S3-S4 are performed in a vacuum environment.

9. The method for producing a photolithography plate according to claim 7, characterized in that: The filler used to form the filling layer is a transparent thermosetting material.

10. The method for producing a photolithography plate according to claim 7, characterized in that: In step S3, the photoresist is kept rotating around the vertical axis, and then a molten filler is injected into the receiving cavity between the substrate and the outer frame, so that the filler is spin-coated on the surface of the substrate to form a filling layer.

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