KR20180134104A - Method for manufacturing pellicle - Google Patents

Abstract

The present invention relates to a method of manufacturing a lithographic pellicle used as a dustproof film when manufacturing a semiconductor device or a liquid crystal display. More particularly, the present invention relates to a method for producing a pellicle for ultraviolet rays. The method comprises a step a) of manufacturing an organic substrate, a step b) of forming a pellicle film on the organic substrate, a step c) of attaching the organic substrate on which the pellicle film is formed to a transfer frame, a step d) of removing at least a portion of the organic substrate, and a step e) of transferring the pellicle film attached to the transfer frame to a pellicle frame. According to the present invention, it is possible to produce a pellicle having an inorganic pellicle film of a very thin thickness and a good condition without wrinkles.

Description

Method for manufacturing pellicle < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a pellicle for lithography used as a vibration damping film when manufacturing a semiconductor device or a liquid crystal display or the like, and more particularly, to a method of manufacturing a pellicle for ultraviolet ray.

In the production of a semiconductor device or a liquid crystal display panel, a method called photolithography is used for patterning a semiconductor wafer or a liquid crystal substrate. In photolithography, a mask is used as an original plate for patterning, and a pattern on the mask is transferred to a wafer or liquid crystal substrate. If the dust adheres to the mask, light is absorbed or reflected by the dust, so that the transferred pattern is damaged, resulting in a problem that the performance and the yield of the semiconductor device, the liquid crystal display panel, and the like are lowered. Therefore, although these operations are usually performed in a clean room, there is dust in the clean room, so that a method of attaching a pellicle to prevent dust from adhering to the surface of the mask is performed. In this case, the dust does not directly adhere to the surface of the mask but sticks to the pellicle film. At the time of lithography, the focal point matches the pattern of the mask, so that the dust on the pellicle is not focused and transferred to the pattern.

Gradually, the required resolution of an exposure apparatus for semiconductor manufacturing is getting higher, and the wavelength of the light source is getting shorter to realize the resolution. Specifically, the UV light source is gradually shortened in ultraviolet light (EUV, extreme ultra violet, 13.5 nm) in the ultraviolet light g line 436, the I line 365, the KrF excimer laser 248 and the ArF excimer laser 193 ought. Development of a new light source, a resist, a mask, and a pellicle is indispensable to realize such an exposure technique using ultraviolet rays. That is, the conventional organic pellicle film has a problem that its physical properties are changed by an exposure light source having a high energy, and its life is short, so that it is difficult to use the pellicle for an ultraviolet ray pellicle. Various attempts have been made to solve these problems.

For example, Patent Publication No. 2009-0088396 discloses a pellicle made of an aerogel film.

Japanese Laid-Open Patent Publication No. 2009-0122114 discloses a pellicle for a super ultraviolet ray, which comprises a pellicle film made of a silicon single crystal film and a base substrate for supporting the pellicle film, wherein the base substrate forms an opening of 60% or more .

However, the pellicle for ultraviolet rays disclosed in Japanese Patent Application Laid-Open No. 2009-0122114 needs to form a silicon single crystal film as a thin film in order to transmit ultraviolet rays. Since such a silicon single crystal thin film can be easily damaged even in a small impact, a base substrate for supporting the silicon single crystal thin film is used. Such reinforcing frame of the base substrate forms a certain pattern, and there is a problem that this pattern is transferred to the substrate in the lithography process. In addition, there is a problem that the transmittance is as low as about 60%.

Since ultraviolet rays have a short wavelength, energy is very high, and because of low transmittance, a considerable amount of energy is absorbed by the pellicle film and the base substrate, and the pellicle film and the base substrate can be heated. Therefore, when the materials of the pellicle film and the base substrate are different from each other, there is a problem that deformation may occur due to the thermal expansion difference caused by the heat generated in the lithography process.

Also disclosed is a method of using a pre-staged pellicle that does not use a separate base substrate to reinforce the pellicle membrane.

For example, Japanese Patent No. 1552940, filed and filed by the present applicant, discloses a method of forming a graphite thin film on a nickel foil and then etching the nickel foil with an aqueous solution containing iron chloride to obtain a separated graphite thin film have.

In addition, Japanese Patent No. 1303795, filed and filed by the present applicant, discloses a method of forming a zirconium or molybdenum metal thin film layer on an organic substrate and then dissolving the organic substrate using a solvent to obtain a pellicle membrane.

In another method, a pellicle film made of an inorganic material is formed on an organic substance substrate, and then an organic substance substrate having a pellicle membrane formed thereon is attached to a pellicle frame, and then an organic substance substrate is removed to produce a pellicle. This method has an advantage in that it is easy to adhere the pellicle membrane to the pellicle frame. However, as shown in FIG. 11, there is a problem that after the organic substrate is removed, wrinkles are formed in the edge portion of the pellicle membrane and it is difficult to use it as a pellicle.

Published Patent No. 2009-0088396 Published Patent No. 2009-0122114 Patent No. 1552940 Patent No. 1303795

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new pellicle manufacturing method capable of preventing wrinkles from being generated in a pellicle membrane.

In order to achieve the above object, the present invention provides a method for manufacturing a pellicle membrane, comprising the steps of: a) preparing an organic substrate, b) forming a pellicle film on the organic substrate, c) attaching the organic substrate on which the pellicle film is formed to the transfer frame And d) removing at least a portion of the organic substrate, and e) transferring the pellicle membrane attached to the transfer frame to the pellicle frame.

Further, the transfer frame is a frame having a circular, elliptical, polygonal shape having a pentagon or more, or a frame having a pair of parallel linear portions and a curved portion connecting the linear portions to each other.

The pellicle film may include at least one layer selected from the group consisting of a silicon carbide (SiC) thin film layer, a silicon (Si) thin film layer, a carbon (C) thin film layer, a boron carbide (B ₄ C) thin film layer, and a zircon (ZrSiO ₄ ) The present invention also provides a method of manufacturing a pellicle.

Further, the pellicle film provides a pellicle manufacturing method in which a silicon (Si) thin film layer and a silicon carbide (SiC) thin film layer are sequentially formed on a silicon carbide (SiC) thin film layer.

B) forming an inorganic thin film layer on the first coating layer; b-3) forming an inorganic thin film layer on the organic coating layer; And forming a second coating layer on the inorganic thin film layer.

Also, in the step b), the organic substrate is cooled by a cooling jig having a cooling surface for supporting and cooling the organic substrate.

The step (e) may further include: (e-1) applying an adhesive to the pellicle frame and then heat-treating the pellicle frame at 80 to 120 ° C for 30 seconds to 120 seconds.

In the step (e), the pellicle frame may be left at room temperature for 1 to 48 hours after the step (e-1).

The step d) includes the steps of disposing the transfer frame having the organic material substrate on which the pellicle film is formed, in a chamber; and jigging the jig with the electrically conductive surface so that the surface is spaced apart from the pellicle film And placing or introducing a plasma in the chamber. The present invention also provides a method of manufacturing a pellicle including the step of forming or introducing a plasma in the chamber.

The jig includes a plate portion having an upper surface in contact with a lower surface of the transfer frame and a protrusion protruding from the plate portion toward the organic material substrate at a height lower than the thickness of the transfer frame, Wherein the protrusions are formed on an upper surface of the protrusions, and the protrusions have side surfaces that maintain a certain distance from the inner surface of the transfer frame.

Further, the jig and the transfer frame provide a method of manufacturing a pellicle electrically connected thereto.

The step d) includes the steps of disposing the transfer frame having the organic material substrate on which the pellicle film is formed in a chamber, irradiating the organic material substrate with ultraviolet light, and forming or introducing ozone in the chamber The present invention also provides a method of manufacturing a pellicle.

Also, a method of manufacturing a pellicle wherein the temperature of the chamber is maintained at less than 90% of the glass transition temperature of the organic substrate.

In addition, the organic material substrate may be prepared from a cellulose acetate butyrate (CAB), a nitrocellulose, a fluororesin, and a poly (methyl methacrylate) substrate.

The inorganic thin film layer may include at least one selected from the group consisting of a silicon carbide (SiC) thin film layer, a silicon (Si) thin film layer, a carbon (C) thin film layer, a boron carbide (B ₄ C) thin film layer, and a zircon (ZrSiO ₄ ) Of the pellicle.

Also, the first coating layer may include a metal selected from ruthenium (Ru), molybdenum (Mo), and niobium (Nb).

Also, the second coating layer may include a metal selected from ruthenium (Ru), molybdenum (Mo), and niobium (Nb).

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to produce a pellicle having an inorganic pellicle film with a very thin thickness and a good condition without wrinkles.

1 is a view for explaining a step of manufacturing an organic substrate in an embodiment of the method for producing a pellicle according to the present invention.
2 is a view showing a state in which a pellicle film is formed in an embodiment of the method for producing a pellicle according to the present invention.
3 is a view showing an example of the pellicle membrane shown in Fig.
4 is a view showing examples of a transfer frame used in an embodiment of the method for manufacturing a pellicle according to the present invention.
5 is a view showing a state in which an organic substrate on which a pellicle film is formed is attached to a transfer frame in an embodiment of the method for manufacturing a pellicle according to the present invention.
6 is a view showing a state in which a conductive jig is disposed in an embodiment of the method for manufacturing a pellicle according to the present invention.
7 is a view showing a state in which an organic substrate is removed in an embodiment of the method for manufacturing a pellicle according to the present invention.
8 is a view showing a pellicle film according to the shape of a transfer frame.
9 is a view illustrating a step of bonding a center portion of a pellicle film attached to a transfer frame to a pellicle frame in an embodiment of the method for manufacturing a pellicle according to the present invention.
10 is a cross-sectional view of a pellicle manufactured by an embodiment of the method for producing a pellicle according to the present invention.
Fig. 11 is a photograph of a conventional pellicle having a wrinkle on an edge portion thereof.

Hereinafter, a method of manufacturing a pellicle according to the present invention will be described in detail with reference to the accompanying drawings.

The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

The method of manufacturing a pellicle according to the present invention comprises the steps of: a) preparing an organic substrate, b) forming a pellicle film on the organic substrate, c) attaching the organic substrate on which the pellicle film is formed to the transfer frame, d) And e) transferring the pellicle film attached to the transfer frame to the pellicle frame.

First, the step of manufacturing the organic material substrate 10 will be described.

As shown in FIG. 1, the organic substrate 10 can be formed by coating a solution in which a resin is dissolved on another substrate 1 having a smooth surface, followed by drying. As the substrate 1, a quartz glass substrate, a general glass substrate, a silicon substrate, or the like can be used, but a quartz glass substrate is preferably used. As the coating method, various known methods can be used. For example, the organic substrate 10 can be formed on the substrate 1 by a coating method such as roll coating, casting, spin coating, water casting, dip coating or langmuir blodgett. When the spin coating method is used, the thickness of the film can be controlled by changing conditions such as the concentration of the solution to be coated on the substrate 1 and the number of revolutions of the spin coater. The organic material substrate 10 may be formed to a thickness of about 0.2 to 2 mu m.

After the drying is completed, a mold jig coated with a cellophane tape or an adhesive is bonded to the organic substrate 10, and the cellophane tape or the frame jig is lifted from one end by hand or mechanical means The organic substrate 10 can be removed.

Examples of the organic substrate 10 include cellulose acetate butyrate (CAB), nitrocellulose, fluororesin, and poly (methyl methacrylate) film.

Next, the step of forming the pellicle film 20 on the organic substrate 10 will be described.

As shown in Fig. 2, the pellicle film 20 is formed on the thin organic substrate 10 made. As the pellicle film 20, an inorganic thin film layer can be used. For example, silicon carbide (SiC), silicon (Si), carbon (C), boron carbide (B ₄ C) thin film layer and zircon (ZrSiO ₄ ) thin film layer can be used as the pellicle film 20.

In order to prevent the temperature of the organic substrate 10 from rising during the process of forming the pellicle film 20, it is preferable to form the pellicle film 20 at room temperature. Further, it is preferable to cool the organic substrate 10 using a cooling jig. The cooling jig may be provided with a pipe through which cooling water can flow.

In addition, the pellicle film 20 may be a multi-layer structure composed of a plurality of thin film layers instead of a single film. For example, a multi-layered inorganic thin film layer including a silicon carbide thin film and a silicon thin film. That is, it may be a multilayer structure of SiC / Si / SiC, SiC / Si, and the like.

3, the pellicle film 20 may have a multi-layer structure composed of a first coating layer 21, an inorganic thin film layer 22, and a second coating layer 23. This structure includes the steps of forming a first coating layer 21 on the organic substrate 10, forming an inorganic thin film layer 22 on the first coating layer 21, 2 < / RTI > coating layer (23). The first coating layer 21 and the second coating layer 23 serve to protect the inorganic thin film layer 22 from a light source of high output. The first coating layer 21 and the second coating layer 23 should be stable to hydrogen radicals generated by EUV light and be capable of protecting the inorganic thin film layer 22 from heat load by EUV light. The first coating layer 21 and the second coating layer 23 preferably include at least one of ruthenium (Ru), molybdenum (Mo), and niobium (Nb). The first coating layer 21 and the second coating layer 23 can be formed by various methods such as a CVD method, a sputtering method, an electron beam deposition method, and an ion beam source deposition method. The inorganic thin film layer 22 may be a single film or may have a multi-layer structure.

Next, the step of attaching the organic substrate on which the pellicle film is formed to the transfer frame will be described.

First, the transfer frame 9 is prepared. As shown in Fig. 4, the transfer frame 9 has a pair of curved lines connecting a pair of rectilinear portions and a rectilinear portion, as shown in Fig. 4 (d) Is preferably a frame composed of two parts. Next, an adhesive 8 is applied to the transfer frame 9 and then heat-treated. 5, the organic substrate 10 on which the pellicle film 20 is formed is adhered to the transfer frame 9 to form a transfer frame 9 having the organic substrate 10 on which the pellicle film 20 is formed 9) can be obtained. 5, the pellicle film 20 is shown bonded to the transfer frame 9. However, the pellicle film 20 may be adhered to the transfer frame 9 so that the organic substrate 10 contacts the transfer frame 9.

Next, a step of removing at least a part of the organic substrate 10 will be described. The step of removing at least a part of the organic substrate 10 may be a dry ashing step. Dry ashing includes a method using plasma, a method using ultraviolet rays and ozone, and the like, without using an acidic solution having a strong oxidizing power and removing organic substances. Hereinafter, the step of removing at least a part of the organic substrate 10 using the plasma will be described.

In this step, the organic substrate 10 attached to the transfer frame 9 is placed in the chamber, a plasma is generated in the vacuum chamber, and the plasma is brought into contact with the organic substrate 10 to remove the organic substrate 10 do. As the plasma, an oxygen plasma can be used.

At this time, the plasma may be concentrated on the transfer frame 9, resulting in a difference in removal rates of the center portion and the peripheral portion of the organic substrate 10. When the periphery of the organic substrate 10 is first removed, the pellicle membrane 20 may be damaged by the tension of the remnants of the organic substrate 10 remaining in the center portion. Therefore, the conductive jig 2 for uniformly inducing the plasma is disposed adjacent to the pellicle film 20 so that the plasma is not concentrated on the transfer frame 9. [

6 is a view showing a state in which the conductive jig is disposed. 6, the conductive jig 2 has a plate-like portion 3 having an upper surface 5 in contact with the lower surface of the transfer frame 9 and a plate-like portion 3 in the direction of the organic substrate 10 in the plate- And a protrusion 4 protruding at a height lower than the thickness of the transfer frame 9. [ The conductive jig 2 and the transfer frame 9 are electrically connected through the contact between the lower surface of the transfer frame 9 and the upper surface 5 of the plate-

The protruding portion 4 has an electrically conductive upper surface 6 and a side surface 7 that maintains a certain distance from the inner surface of the transfer frame 9 and maintains a constant gap with the organic substrate 10. Arranging the conductive jig 2 makes it possible to prevent the plasma from acting on the organic substrate 10 uniformly and damaging the pellicle film 20.

After the organic substrate 10 is removed, the pressure of the vacuum chamber is slowly raised to atmospheric pressure over about 1 hour, and the transfer frame 9 with the pellicle film 20 attached thereon is removed from the vacuum chamber. This is because if the pressure is increased rapidly, the pellicle membrane 20 may be damaged because the membrane is in a thin state.

As another method of dry ashing, there is a method of removing the organic material substrate 10 by using ultraviolet rays (UV) and ozone at normal pressure. The organic substrate 10 attached to the transfer frame 9 is placed in a chamber in which ultraviolet lamps are arranged, and then the ozone is generated in the chamber to remove the organic substrate 10. [ At this time, if the temperature of the chamber is raised, the ashing rate is increased. However, if the temperature is increased, the organic substrate 10 may be denatured and the organic substrate 10 may be difficult to remove. Thus, it is desirable that the temperature of the chamber be maintained at less than 90% of the glass transition temperature of the organic substrate 10.

7 is a view showing a state where an organic substrate is removed. 7, an adhesive layer 8 is disposed between the transfer frame 9 and the pellicle film 20. As shown in Fig.

8 is a view showing a pellicle film attached to a transfer frame. 8, when the organic substrate 10 on which the pellicle film 20 is formed is adhered to the transfer frame 9 and the organic substrate 10 is removed, wrinkles are generated in the edge portions of the pellicle film 20 . The phenomenon such as elongation of the pellicle film 20 is not observed in the structure in which the pellicle film 20 is formed on the organic substrate 10 because the thickness of the organic substance substrate 10 is relatively thicker than the thickness of the pellicle film 20 When the glass substrate 10 is removed, the pellicle film 20 is stretched and wrinkles are generated. This is because the area of the pellicle film 20 is larger than the area of the organic substrate 10 due to heat generated in the process of manufacturing the pellicle film 20 and cooling of the organic substrate 10 and the like.

The area where the wrinkles are generated is greatly influenced by the shape of the transfer frame 9. As the number of vertexes increases, the area of the polygon where the corrugation occurs becomes closer to the transfer frame 9, and the area of the corrugation area becomes smaller. As can be seen from Figs. 8A and 8B, the area of the wrinkle generation area in the case of using the octagonal transfer frame 9 is much smaller than that in the case of using the rectangular transfer frame 9. 8 (c) and 8 (d), the area of the wrinkle generation area also decreases when the circular or elliptical transfer frame 9 is used. Further, even in the case of using the transfer frame of the type shown in FIG. 8E, the wrinkle occurrence area decreases.

Next, the step of transferring the pellicle film 20 attached to the transfer frame 9 to the pellicle frame 30 will be described.

First, the pellicle frame 30 is prepared. The pellicle frame 30 may be an aluminum alloy frame in which a black alumite coating or a diamond like carbon (DLC) coating, a silicon carbide (SiC) coating, an oxidized plasma coating, or the like is formed. The pellicle frame 30 may be polygonal, circular, or elliptical with a square or more depending on its use.

Next, the adhesive 40 is applied to the pellicle frame 30 and then heat-treated at about 80 to 120 DEG C for about 30 to 120 seconds. Then, it is left at room temperature for about 1 hour to 48 hours to remove the organic gas of the adhesive 40. Then, as shown in Fig. 9, the wrinkle free center portion of the pellicle film 20 attached to the transfer frame 9 is adhered to the pellicle frame 30. As shown in Fig. When the pellicle film 20 is cut along the edge of the pellicle frame 30, a pellicle in which the pellicle film 20 without wrinkles is attached to the pellicle frame 30 can be obtained as shown in Fig.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

10: organic substrate
20: Pellicle membrane
21: First coating layer
22: inorganic thin film layer
23: Second coating layer
30: Pellicle frame
40: Adhesive

Claims (17)

comprising the steps of: a) preparing an organic substrate,
b) forming a pellicle film on the organic substrate,
c) attaching the organic material substrate on which the pellicle film is formed to a transfer frame,
d) removing at least a portion of the organic substrate,
e) transferring the pellicle membrane attached to the transfer frame to the pellicle frame. The method according to claim 1,
Wherein the transfer frame is a frame having a circular shape, an elliptical shape, a polygonal shape having a pentagon or more, or a curved portion connecting a pair of parallel straight portions and straight portions. The method according to claim 1,
Wherein the pellicle film comprises a silicon carbide (SiC) thin film layer, a silicon (Si) thin film layer, a carbon (C) thin film layer, a boron carbide (B ₄ C) thin film layer. Zircon (ZrSiO ₄ ) thin film layer. The method according to claim 1,
Wherein the pellicle film is a multi-layer structure in which a silicon (Si) thin film layer and a silicon carbide (SiC) thin film layer are formed in order on a silicon carbide (SiC) thin film layer. The method according to claim 1,
The step b)
b-1) forming a first coating layer on the organic substrate,
b-2) forming an inorganic thin film layer on the first coating layer,
b-3) forming a second coating layer on the inorganic thin film layer. The method according to claim 1,
Wherein the organic material substrate is cooled by a cooling jig having a cooling surface for supporting and cooling the organic material substrate in the step b). The method according to claim 1,
The step e)
e-1) applying an adhesive to the pellicle frame, and then heat-treating the pellicle frame at 80 to 120 DEG C for 30 seconds to 120 seconds. 8. The method of claim 7,
The step e)
wherein the pellicle frame is left at room temperature for 1 to 48 hours after the step (e-1). The method according to claim 1,
The step d)
Disposing the transfer frame to which the organic material substrate on which the pellicle film is formed is placed in a chamber;
Positioning a jig having an electrically conductive surface such that the surface is spaced apart from the pellicle membrane and spaced apart,
And forming or introducing a plasma into the chamber. 10. The method of claim 9,
Wherein the jig includes a plate portion having an upper surface in contact with a lower surface of the transfer frame and a protrusion protruding from the plate portion toward the organic substrate in a height lower than the thickness of the transfer frame, Wherein the projecting portion has a side surface that is spaced apart from the inner surface of the transfer frame at a predetermined interval. 11. The method of claim 10,
And the jig and the transfer frame are electrically connected to each other. The method according to claim 1,
The step d)
Disposing the transfer frame to which the organic material substrate on which the pellicle film is formed is placed in a chamber;
Irradiating the organic substrate with ultraviolet light,
And forming or introducing ozone into the chamber. 13. The method of claim 12,
Wherein the temperature of the chamber is maintained at less than 90% of the glass transition temperature of the organic substrate. The method according to claim 1,
Wherein the organic substrate is selected from the group consisting of cellulose acetate butyrate (CAB), nitrocellulose, fluororesin, and poly (methyl methacrylate). 6. The method of claim 5,
The inorganic thin film layer may include at least one layer selected from the group consisting of a silicon carbide (SiC) thin film layer, a silicon (Si) thin film layer, a carbon (C) thin film layer, a boron carbide (B ₄ C) thin film layer, and a zircon (ZrSiO ₄ ) ≪ / RTI > 6. The method of claim 5,
Wherein the first coating layer comprises a metal selected from ruthenium (Ru), molybdenum (Mo), and niobium (Nb). 6. The method of claim 5,
Wherein the second coating layer comprises a metal selected from ruthenium (Ru), molybdenum (Mo), and niobium (Nb).

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