TWI688635B - DUV photomask protective film aluminum frame adhesive treatment method - Google Patents

Abstract

A DUV photomask protective film aluminum frame adhesive treatment method is to apply a layer of photosensitive pressure sensitive adhesive on the surface of the aluminum mask attached to the aluminum frame. The photosensitive pressure sensitive adhesive has low viscosity characteristics and is coated on the surface of the aluminum frame At the time, the uneven surface of the aluminum frame can be filled and filled, so that the photosensitive pressure-sensitive adhesive and the surface of the aluminum frame are in face-to-face contact, and then the light-transmitting flat substrate surface with a release agent layer is covered on the photosensitive pressure-sensitive adhesive, so that The release agent is in contact with the photosensitive pressure-sensitive adhesive, and then an ultraviolet light is exposed to the photosensitive pressure-sensitive adhesive from the other surface of the substrate without the release agent, the photosensitive pressure-sensitive adhesive is polymerized, and then the flat substrate and the high After the molecular pressure sensitive adhesive is separated, an adhesive surface with a flat surface can be obtained.

Description

DUV photomask protective film aluminum frame adhesive treatment method

The invention relates to an aluminum frame adhesive treatment method for a DUV photomask protective film, in particular to fill up the uneven surface of the aluminum frame with liquid photosensitive pressure-sensitive adhesive, and then flatten the surface of the photosensitive pressure-sensitive adhesive Molecularization, when the aluminum frame is pressed against the photomask, the photomask can be evenly stressed without causing deformation.

According to the current semiconductor device manufacturing technology, the circuit pattern of the semiconductor device is transferred to the surface of the silicon wafer through a lithography process, specifically, a light source of a specific wavelength is projected through a photomask Way, the circuit pattern is transferred to the surface of the silicon wafer.

Generally, an aluminum frame is provided on the surface of the photomask, and an adhesive is adhered between the surface of the photomask and the aluminum frame, and the aluminum frame is covered with a mask protection film. With the development of miniaturization, the requirements for the flatness of the surface of the reticle are becoming more and more strict.

In addition, when the aluminum frame is bonded to the surface of the photomask, if the surface of the primer bonding the aluminum frame and the surface of the photomask is not flat, when the protective film aluminum frame is pasted to the photomask, due to different forces, This will cause the flatness of the reticle surface to change, and the change in the flatness will cause the pattern shape on the reticle surface to change, affecting the subsequent exposure accuracy or overlapping degree of the multi-layer reticle.

As shown in FIG. 1, it is a schematic diagram of conventional aluminum frame coating adhesive, which is mainly to coat a layer of hot-melt pressure-sensitive adhesive 101 or silicon polymer solution or acrylic polymer latex on the aluminum frame 100 when the adhesive is cooled or Solution wave After the hair is released, a very flat quartz substrate is pressed on the adhesive to form a pressure sensitive adhesive 101 with a flat surface on the aluminum frame 100. The pressure sensitive adhesive 101 can be used to adhere to the photomask A film 102 is attached to the other end surface of the aluminum frame 100. The film 102 is used to protect the photomask from exposure to fine dust.

However, since the surface of the aluminum frame 100 is usually anodized, the surface of the aluminum frame 100 has numerous irregularities, and the conventional pressure-sensitive adhesive 101 is a polymer adhesive, which is known to be sticky. High degree, and cannot fill the concave and convex surface of the aluminum frame 100, so that the bonding surface of the pressure sensitive adhesive 101 and the aluminum frame 100 is bump contact, the concave surface will form a hollow; when the pressure sensitive adhesive 100 is pressed on the photomask It is necessary to apply a pressure toward the photomask 103 on the aluminum frame 100 to fix the aluminum frame 100 on the photomask, but because the bonding surface of the pressure sensitive adhesive 101 and the aluminum frame 100 is point-to-point contact, when pressure is applied , Will cause uneven pressure on the convex contact surface and the concave cavity surface, resulting in slight deformation of the surface of the photomask 103 due to uneven force, however such slight deformation will cause distortion of the pattern shape on the surface of the photomask 103 , Affect the exposure yield, so the above-mentioned traditional flattening process is still flawed.

Therefore, if it is possible to design a face-to-face contact between the glue and the aluminum frame to make the photomask evenly stressed, the pattern shape on the surface of the photomask can be prevented from being distorted, so the present invention should be the most Best solution.

The invention relates to a method for processing an aluminum frame adhesive of a DUV photomask protective film. The method is as follows: an aluminum frame is taken, the top surface of the aluminum frame is an uneven surface, and the aluminum frame is placed in a frame-shaped positioning space of a jig , The positioning space is formed by two corresponding surrounding walls, the surrounding walls are higher than the height of the aluminum frame, so that there is a height difference between the top surface of the aluminum frame and the surrounding wall; a layer is coated on the top surface of the aluminum frame and the top of the surrounding wall Noodles are close to cut, and It is a single-molecule low-viscosity liquid photosensitive pressure-sensitive adhesive. The photosensitive pressure-sensitive adhesive penetrates into the concave-convex surface of the aluminum frame, fills the concave-convex surface, and is shaped by the surrounding wall; take a transparent substrate The light-transmitting substrate has an extremely flat surface, and an extremely flat release agent layer is formed on the extremely flat surface. The release agent layer of the light-transmitting substrate covers the top surface of the surrounding wall of the jig and simultaneously presses against On the surface of the photosensitive pressure-sensitive adhesive, the release agent layer is brought into contact with the photosensitive pressure-sensitive adhesive, so that the photosensitive pressure-sensitive adhesive forms a flat adhesive surface; take an ultraviolet lamp, and place the ultraviolet lamp in the unset The other side of the light-transmitting substrate of the release agent layer exposes the ultraviolet light generated by the ultraviolet lamp toward the photosensitive pressure-sensitive adhesive, and the photosensitive pressure-sensitive adhesive is converted into a polymer non-hardened pressure-sensitive adhesive after exposure , And has high viscosity; by setting the release agent layer, the transparent substrate can be easily removed from the surface of the pressure-sensitive adhesive, so that the adhesive surface of the photosensitive pressure-sensitive adhesive is formed into an extremely flat surface, and the aluminum frame Remove the jig; take a thin film layer, the thin film layer is bonded to the other surface of the aluminum frame where the pressure-sensitive adhesive is not provided, the thin film can prevent fine dust from falling on the photomask.

In a preferred embodiment, the transparent substrate is a quartz substrate.

In a preferred embodiment, there is a height difference between the top surface of the aluminum frame and the surrounding wall, the height difference is 0.2 mm to 0.8 mm, and the thickness of the pressure sensitive adhesive is relatively controlled to be 0.2 mm to 0.8 mm.

In a preferred embodiment, the exposure time of the ultraviolet light is 5 minutes.

Idiom

100: aluminum frame

101: pressure sensitive adhesive

102: film

103: Mask

Symbol of the invention

1: Aluminum frame

11: uneven surface

2: photosensitive pressure sensitive adhesive

2’: Pressure sensitive adhesive

3: Translucent substrate

4: Release agent layer

5: Mask

6: Film layer

7: UV lamp

71: Ultraviolet light

8: Fixture

81: positioning space

82: fence

h: height difference

[Figure 1] is a schematic diagram of a conventional protective film frame.

[Figure 2A] This is a schematic diagram of the implementation of the treatment method of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention.

[Figure 2B] This is a schematic diagram of the implementation of the treatment method of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention.

[Figure 2C] This is a schematic diagram of the implementation of the processing method of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention.

[Figure 2D] It is a schematic diagram of the implementation of the processing method of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention.

[Figure 2E] This is a schematic diagram of the implementation of the processing method of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention.

[Fig. 2F] It is a schematic diagram of the implementation processing structure of the aluminum frame adhesive processing method of the DUV mask protective film of the present invention.

[Figure 2G] This is a schematic diagram of the implementation of the processing method of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention.

[Figure 2H] This is a schematic diagram of the implementation of the processing method of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention.

[Figure 3] This is a schematic view of the structure of the combination of the DUV photomask protective film aluminum frame adhesive treatment method of the present invention and the photomask.

Regarding other technical contents, features and effects of the present invention, it will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings.

Please refer to Figures 2A~2F, which is a schematic diagram of the preparation process of the aluminum frame adhesive treatment method of the DUV mask protective film of the present invention. From the figure, the steps are: as shown in Figures 2A and 2B, an aluminum frame is taken 1. The surface of the aluminum frame 1 is a concave-convex surface 11, and the aluminum frame 1 is placed on a jig 8, the jig 8 has a frame-shaped positioning space 81, which is formed by Two corresponding surrounding walls 82 are formed. The surrounding walls 82 are higher than the height of the aluminum frame 1. The aluminum frame 1 is positioned in the positioning space 81 so that there is a 0.2mm~0.8 between the top surface of the aluminum frame 1 and the surrounding wall 82 mm height difference h, the height difference h is 0.2mm, 03mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm or 0.8mm; please refer to Figure 2C, coating a layer of liquid on the top surface of aluminum frame 1 The photosensitive pressure-sensitive adhesive 2 is in the shape of a single molecule with low viscosity, so that the photosensitive pressure-sensitive adhesive 2 can penetrate into the uneven surface 11 of the aluminum frame 1 to fill the uneven surface 11 to make the photosensitive The pressure-sensitive adhesive 2 is in face-to-face contact with the surface of the aluminum frame to achieve the purpose of average force and force, and the liquid adhesive photosensitive pressure-sensitive adhesive 2 will be close to the top surface of the surrounding wall 82 and be blocked by the surrounding wall 82 Shaping, so that the thickness of the photosensitive pressure-sensitive adhesive 2 on the aluminum frame 1 is 0.2mm~0.8mm, wherein the thickness of the photosensitive pressure-sensitive adhesive is 0.2mm, 03mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm or 0.8mm; please refer to Figure 2D, take a transparent substrate 3, the transparent substrate 3 has a very flat surface (surface flatness of 1-5μm), evenly coated on the very flat surface The release agent layer 4 also has a surface with a flatness of 1-5 μm. The release agent layer 4 of the light-transmitting substrate 3 covers the top surface of the surrounding wall 82 of the jig 8 and is pressed against The surface of the photosensitive pressure-sensitive adhesive 2 brings the release agent layer 4 into contact with the photosensitive pressure-sensitive adhesive 2, so that the photosensitive pressure-sensitive adhesive 2 is pressed by the weight of the light-transmitting substrate 3, and the release agent layer 4 is flat The surface is affected to form a flat adhesive surface; wherein, the transparent substrate 3 is a quartz substrate; please refer to FIG. 2E, take an ultraviolet lamp 7 and place the ultraviolet lamp 7 in the release agent On the other side of the transparent substrate 3 of the layer 4, the ultraviolet light 71 generated by the ultraviolet lamp 7 is exposed to the photosensitive pressure-sensitive adhesive 2 for at least 5 minutes, and the photosensitive pressure-sensitive adhesive 2 is converted into a polymer The hardened pressure-sensitive adhesive 2'has high viscosity; please refer to FIG. 2F, the design of the release agent layer 4 allows the transparent substrate 3 to be easily removed from the surface of the polymer pressure-sensitive adhesive 2', As a result, the adhesive surface of the pressure-sensitive adhesive 2'is formed as an extremely flat surface, without Affected by the uneven surface 11 of the aluminum frame 1, as shown in Figure 2G, at the same time, the aluminum frame is removed from the jig 8; please refer to Figure 2H, the aluminum frame 1 is not provided with another polymer pressure sensitive adhesive 2' A thin film layer 6 is combined on the surface to form a cover body. The thin film layer 6 can prevent fine dust from falling on the photomask.

Please refer to FIG. 3, the polymer photosensitive pressure-sensitive adhesive 2 on the aluminum frame 1 can be attached to the surface of a photomask 5, and the other surface of the aluminum frame 1 is the film layer 6 to prevent Fine dust falls on the photomask 5. Since the pressure-sensitive adhesive 2'has filled the uneven surface 11 of the aluminum frame 1, the adhesive surface of the pressure-sensitive adhesive 2'combined with the aluminum frame 1 will not be affected by the uneven surface. Void, and with the flat adhesive surface of the pressure-sensitive adhesive 2', when the pressure-sensitive adhesive 2'on the aluminum frame 1 is attached to the surface of a photomask 5, when the aluminum frame 1 applies a pressure to the photomask 5 At this point, each stress point of the photomask 5 is averagely stressed without deformation, thereby ensuring that the surface pattern of the photomask 5 is not deformed.

Compared with other conventional technologies, the DUV photomask protective film aluminum frame adhesive treatment method provided by the present invention has the following advantages:

(1) In the present invention, the liquid photosensitive pressure-sensitive adhesive is used to fill the uneven surface of the aluminum frame first, so that there is no gap between the surface of the aluminum frame and the photosensitive pressure-sensitive adhesive, and then the photosensitive pressure-sensitive adhesive is polymerized to form a High-viscosity pressure-sensitive adhesive, when the aluminum frame is pressed on the surface of the reticle, can effectively avoid the situation that the pattern on the surface of the reticle changes due to uneven force application.

(2) The present invention can effectively improve the yield of the photomask in the lithography process.

The present invention has been disclosed as above through the above embodiments, but it is not intended to limit the present invention. Anyone who is familiar with this technical field and has general knowledge should understand the foregoing technical features and embodiments of the present invention without departing from the scope of the present invention. No changes or modifications can be made within the spirit and scope, so the patent protection scope of the present invention shall be subject to the definition as defined in the claims attached to this specification.

1: Aluminum frame

11: uneven surface

2’: Pressure sensitive adhesive

6: Film layer

Claims (4)

A DUV (deep ultraviolet) mask protective film aluminum frame adhesive treatment method, the method is: take an aluminum frame, the top surface of the aluminum frame is a concave and convex surface, the aluminum frame is placed in a jig-shaped positioning In the space, the positioning space is formed by two corresponding surrounding walls, which are higher than the height of the aluminum frame, so that there is a height difference between the top surface of the aluminum frame and the surrounding wall; The top surface of the fence is close to cut, and is a single-molecule low-viscosity liquid-state photosensitive pressure-sensitive adhesive. The photosensitive pressure-sensitive adhesive penetrates into the concave and convex surface of the aluminum frame, fills the concave and convex surface, and is blocked by the fence Shaping; take a light-transmitting substrate, the light-transmitting substrate has a very flat surface, a very flat parting agent layer on the very flat surface, covering the parting agent layer of the light-transmitting substrate On the top surface of the surrounding wall of the jig and simultaneously press against the surface of the photosensitive pressure-sensitive adhesive, so that the release agent layer is in contact with the photosensitive pressure-sensitive adhesive, so that the photosensitive pressure-sensitive adhesive forms a flat adhesive surface; An ultraviolet lamp, the ultraviolet lamp is placed on the other side of the translucent substrate without the release agent layer, so that the ultraviolet light generated by the ultraviolet lamp will be exposed to the photosensitive pressure-sensitive adhesive, and the photosensitive pressure-sensitive adhesive is exposed through After that, it is converted into a polymer non-hardened pressure-sensitive adhesive, which has high viscosity; by setting the release agent layer, the transparent substrate is easily removed from the surface of the pressure-sensitive adhesive, resulting in the adhesive surface of the photosensitive pressure-sensitive adhesive It is formed as an extremely flat surface, and at the same time, the aluminum frame is removed from the jig; a thin film layer is taken, and the thin film layer is bonded to the other surface of the aluminum frame on which the pressure-sensitive adhesive is not provided. on. The DUV mask protective film aluminum frame adhesive treatment method according to claim 1, wherein the transparent substrate is a quartz substrate. The DUV mask protective film aluminum frame adhesive treatment method as described in claim 1, wherein the There is a height difference between the top surface of the aluminum frame and the surrounding wall, the height difference is 0.2mm~0.8mm, and the thickness of the pressure sensitive adhesive is relatively controlled to be 0.2mm~0.8mm. The DUV photomask protective film aluminum frame adhesive treatment method according to claim 1, wherein the exposure time of the ultraviolet light is 5 minutes.

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