TW201938722A - Method for treating DUV photomask protective film aluminum frame adhesive in which a photosensitive and pressure sensitive adhesive having a low viscosity property is coated on the surface of an aluminum frame - Google Patents

Abstract

A method for treating DUV photomask protective film aluminum frame adhesive includes coating a layer of photosensitive and pressure sensitive adhesive on a surface where an aluminum frame is adhered to a photomask, wherein the photosensitive and pressure sensitive adhesive has a low viscosity property and when it is coated on the surface of the aluminum frame, it can fill up the uneven surface of the aluminum frame, so that the photosensitive and pressure sensitive adhesive and the surface of the aluminum frame are in contact in a face-to-face manner; then covering a transparent flat substrate having a layer of a release agent on the photosensitive and pressure sensitive adhesive, so that the release agent is in contact with the photosensitive and pressure sensitive adhesive; and then, exposing the photosensitive and pressure sensitive adhesive to ultraviolet light through the other surface of the substrate having no release agent to polymerize the photosensitive and pressure sensitive adhesive; and then separating the flat substrate and the polymer pressure sensitive adhesive to obtain a rubber surface having a flat surface.

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 and fill the uneven surface of an aluminum frame with a liquid photosensitive pressure-sensitive adhesive, and then flatten the surface of the photosensitive pressure-sensitive adhesive and perform high When it is molecularized, 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 a semiconductor device is transferred to the surface of a silicon wafer through a lithography process. Specifically, a light source with a specific wavelength is projected through a photomask. Method, the circuit pattern is transferred to the surface of the silicon wafer.

In general, an aluminum frame is provided on the surface of the photomask, and the surface of the photomask and the aluminum frame are adhered with an adhesive, and the aluminum frame is covered with a photomask protective film. With the development of miniaturization, the requirements for the flatness of the surface of the photomask are becoming stricter.

In addition, when the aluminum frame is bonded to the surface of the photomask, if the surface of the primer that the aluminum frame is combined with the surface of the photomask is uneven, when the protective film aluminum frame is adhered to the photomask, due to the difference in force, This will cause the flatness of the mask surface to change, and the change in flatness will change the shape of the pattern on the surface of the mask, which will affect the subsequent exposure accuracy or overlap of the multilayer mask.

As shown in Figure 1, it is a schematic diagram of a conventional aluminum frame coating adhesive, which is mainly coated with a layer of hot-melt pressure-sensitive adhesive 101 or a silicon polymer solution or an acrylic polymer latex on the aluminum frame 100. When the glue is cooled or After the solution is volatilized, a very flat quartz substrate is pressed against the glue 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 bonded to the other end surface of the aluminum frame 100, and the film 102 is used to protect the photomask from the exposure of the dust.

However, since the surface of the aluminum frame 100 is usually anodized, the surface of the aluminum frame 100 has countless uneven surfaces, and the pressure-sensitive adhesives 101 that are conventionally used are polymer adhesives. The degree is high, and it is impossible to fill and 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 in convex contact, and the concave surface forms a cavity; when the pressure-sensitive adhesive 100 is pressed on the photomask You must apply a pressure on the aluminum frame 100 toward the photomask 103 to adhere the aluminum frame 100 to the photomask. However, since 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 mask 103 due to uneven force, but such slight deformation will distort the pattern shape on the surface of the mask 103 Affects the exposure yield, so the above-mentioned conventional planarization process still has defects.

Therefore, if a surface-to-surface contact between the glue and the aluminum frame can be devised so that the mask is evenly stressed, the distortion of the pattern shape on the surface of the mask can be avoided. Therefore, the present invention should be the most Best solution.

The invention relates to a method for treating an aluminum frame of a DUV photomask protective film. The method is as follows: take an aluminum frame, the top surface of the aluminum frame is a concave and convex surface, and place the aluminum frame in a frame-shaped positioning space of a fixture. 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; a layer is coated on the top surface of the aluminum frame and the top of the surrounding wall The surface is nearly aligned, and is a single-molecule low-viscosity liquid-state 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 light-transmitting substrate, the light-transmitting substrate has a very flat surface, there is a very flat release agent layer on the extremely flat surface, and the release agent layer of the light-transmitting substrate covers the surrounding wall of the jig; The top surface is pressed against the surface of the photosensitive pressure-sensitive adhesive at the same time, 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 rubber surface; take an ultraviolet lamp, and convert ultraviolet light The lamp is placed on the other side of the light-transmitting substrate without the release agent layer, The ultraviolet light generated by the ultraviolet lamp will be exposed to the photosensitive pressure-sensitive adhesive, so that the photosensitive pressure-sensitive adhesive is converted into a polymer non-hardened pressure-sensitive adhesive after exposure, and has high viscosity; by the release agent layer, Set so that the light-transmitting substrate is easily removed from the surface of the pressure-sensitive adhesive, so that the adhesive surface of the light-sensitive pressure-sensitive adhesive is formed into an extremely flat surface, and the aluminum frame is moved out of the jig at the same time; The aluminum frame is not provided on the other surface of the pressure-sensitive adhesive, and the 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, the height difference between the top surface of the aluminum frame and the surrounding wall is 0.2mm ~ 0.8mm, and the thickness of the pressure-sensitive adhesive is controlled between 0.2mm ~ 0.8mm.

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

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

Please refer to FIGS. 2A to 2F, which are schematic diagrams of the preparation process of the aluminum frame adhesive treatment method for the DUV mask protective film of the present invention. As can be seen from the figure, the steps are:

As shown in Figs. 2A and 2B, an aluminum frame 1 is taken. The surface of the aluminum frame 1 is a concave-convex surface 11. The aluminum frame 1 is placed on a jig 8 having a frame-shaped positioning space 81. The positioning space is formed by two corresponding fences 82, which are higher than the height of the aluminum frame 1. The aluminum frame 1 is positioned in the positioning space 81 so that the top surface of the aluminum frame 1 and the fence 82 Has a height difference h of 0.2mm to 0.8mm, and the height difference h is 0.2mm, 03mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm or 0.8mm;

Please refer to FIG. 2C, a layer of liquid photosensitive pressure-sensitive adhesive 2 is coated on the top surface of the aluminum frame 1. The photosensitive pressure-sensitive adhesive 2 is a single molecule with low viscosity, so that the photosensitive pressure-sensitive adhesive 2 can penetrate into the aluminum. The concave-convex surface 11 of the frame 1 is filled with the concave-convex surface 11 so that the photosensitive pressure-sensitive adhesive 2 and the surface of the aluminum frame are in face-to-face contact to achieve the purpose of average force and force. 2 will be nearly aligned with the top surface of the surrounding wall 82, and will be blocked and shaped by the surrounding wall 82, so that the thickness of the photosensitive pressure-sensitive adhesive 2 on the aluminum frame 1 is 0.2 mm to 0.8 mm. Thickness is 0.2mm, 03mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm or 0.8mm;

Referring to FIG. 2D, a light-transmitting substrate 3 is taken. The light-transmitting substrate 3 has an extremely flat surface (surface flatness is 1-5 μm), and a release agent layer is evenly coated on the extremely flat surface. 4. The release agent layer also has a surface with a flatness of 1-5 μm. The release agent layer 4 of the transparent substrate 3 covers the top surface of the surrounding wall 82 of the jig 8 and presses against the photosensitive pressure at the same time. The surface of the pressure-sensitive adhesive 2 makes the release agent layer 4 in contact with the photosensitive pressure-sensitive adhesive 2, so that the photosensitive pressure-sensitive adhesive 2 is held by the weight of the light-transmitting substrate 3, and the flat surface of the release agent layer 4 is affected. Forming a flat rubber surface; wherein the transparent substrate 3 is a quartz substrate;

Referring to FIG. 2E, take an ultraviolet lamp 7 and place the ultraviolet lamp 7 on the other side of the light-transmitting substrate 3 without the release agent layer 4 so that the ultraviolet light 71 generated by the ultraviolet lamp 7 is directed toward the The photosensitive pressure-sensitive adhesive 2 is exposed to light for at least 5 minutes, so that the photosensitive pressure-sensitive adhesive 2 is converted into a polymer non-hardened pressure-sensitive adhesive 2 'after exposure, and has high viscosity;

Please refer to FIG. 2F. With the design of the release agent layer 4, the light-transmitting substrate 3 is easily removed from the surface of the polymer pressure-sensitive adhesive 2 ', so that the adhesive surface of the pressure-sensitive adhesive 2' is formed into a pole. The flat surface will not be affected by the uneven surface 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 FIG. 2H. A thin film layer 6 is combined on the other surface of the aluminum frame 1 without the polymer pressure-sensitive adhesive 2 '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 thin film layer 6 to prevent Fine dust falls on the photomask 5, because the pressure-sensitive adhesive 2 'has filled the concave-convex surface 11 of the aluminum frame 1, the adhesive surface of the pressure-sensitive adhesive 2' bonded to the aluminum frame 1 is not affected by the concave-convex surface. Hollow, and through 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 Each force receiving point of the photomask 5 is an average force, and no deformation occurs, thereby ensuring that the surface pattern of the photomask 5 does not deform.

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) The present invention uses liquid photosensitive pressure-sensitive adhesive to fill the concave and convex surface of the aluminum frame first, and then There is no gap between the surface of the aluminum frame and the surface of the photosensitive pressure-sensitive adhesive, and then the photosensitive pressure-sensitive adhesive is polymerized to form a highly viscous pressure-sensitive adhesive. When the aluminum frame is pressed on the surface of the photomask, it can effectively Avoid the situation that the mask surface pattern changes due to uneven force. (2) The invention can effectively improve the yield of the photomask in the lithography process.

The present invention has been disclosed as above through the above-mentioned embodiments, but it is not intended to limit the present invention. Anyone with ordinary knowledge in this technical field will understand the aforementioned technical features and embodiments of the present invention without departing from the scope of the present invention. Within the spirit and scope, minor changes and retouching are not allowed. Therefore, the scope of patent protection of the present invention shall be subject to the definition in the claims attached to this specification.

Conventional symbols

100‧‧‧ aluminum frame

101‧‧‧ pressure sensitive adhesive

102‧‧‧ film

103‧‧‧Mask

Present symbol

1‧‧‧ aluminum frame

11‧‧‧ uneven surface

2‧‧‧ photosensitive pressure-sensitive adhesive

2’‧‧‧ pressure-sensitive adhesive

3‧‧‧Transparent substrate

4‧‧‧ release agent layer

5‧‧‧Mask

6‧‧‧ film layer

7‧‧‧ UV lamp

71‧‧‧ultraviolet light

8‧‧‧ jig

81‧‧‧ positioning space

82‧‧‧ fence

[Figure 1] is a schematic diagram of a conventional protective film frame. [FIG. 2A] It is a schematic diagram of the implementation structure of the method for processing the aluminum frame adhesive of the DUV photomask protective film of the present invention. [FIG. 2B] It is a schematic diagram of the implementation structure of the method for processing the aluminum frame adhesive of the DUV photomask protective film of the present invention. [FIG. 2C] It is a schematic diagram of the implementation structure of the method for processing the aluminum frame adhesive of the DUV photomask protective film of the present invention. [FIG. 2D] It is a schematic diagram of the implementation structure of the method for processing the aluminum frame adhesive of the DUV photomask protective film of the present invention. [FIG. 2E] It is a schematic diagram of a treatment structure for implementing an adhesive treatment method for an aluminum frame of a DUV photomask protective film according to the present invention. [FIG. 2F] It is a schematic diagram of the structure of the implementation of the method for processing the adhesive treatment of the aluminum frame of the DUV photomask protective film of the present invention. [FIG. 2G] It is a schematic diagram of the implementation structure of the method for processing the aluminum frame adhesive of the DUV photomask protective film of the present invention. [FIG. 2H] It is a schematic diagram of the implementation structure of the method for processing the aluminum frame adhesive of the DUV photomask protective film of the present invention. [FIG. 3] It is a schematic view of a combination structure with a photomask of the method for processing an aluminum frame of a DUV photomask protective film according to the present invention.

Claims (4)

A DUV photomask protective film aluminum frame adhesive treatment method is as follows: take an aluminum frame, the top surface of the aluminum frame is a concave-convex surface, and place the aluminum frame in a frame-shaped positioning space of a jig; the positioning The space is formed by two corresponding surrounding walls. The height of the surrounding wall is higher than that of the aluminum frame, so that there is a height difference between the top surface of the aluminum frame and the surrounding wall. And 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 up the concave-convex surface, and is shaped by the retaining wall; A light-transmitting substrate having a very flat surface, a very flat release agent layer on the extremely flat surface, covering the top surface of the wall of the fixture with the release agent layer of the light-transmitting substrate, 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 rubber surface; take an ultraviolet lamp, and place the ultraviolet lamp on The other side of the light-transmitting substrate without the release agent layer, so that the ultraviolet The ultraviolet light generated by the line lamp will be exposed to the photosensitive pressure-sensitive adhesive, so that the photosensitive pressure-sensitive adhesive is converted into a polymer non-hardened pressure-sensitive adhesive through exposure, and has high viscosity; by the release agent layer, Set so that the light-transmitting substrate is easily removed from the surface of the pressure-sensitive adhesive, so that the adhesive surface of the light-sensitive pressure-sensitive adhesive is formed into an extremely flat surface, and at the same time, the aluminum frame is removed from the fixture; a thin film layer is taken, and the thin film layer is bonded to The aluminum frame is not provided on the other surface of the pressure-sensitive adhesive, and the film can prevent fine dust from falling on the photomask. The method for processing a DUV photomask protective film aluminum frame adhesive according to claim 1, wherein the transparent substrate is a quartz substrate. The method for processing a DUV photomask protective film aluminum frame adhesive according to claim 1, wherein the height difference between the top surface of the aluminum frame and the surrounding wall is 0.2 mm to 0.8 mm, and the pressure sensitivity is relatively controlled. The glue thickness is 0.2mm ~ 0.8mm. The method for processing a DUV photomask protective film aluminum frame adhesive according to claim 1, wherein the exposure time of the ultraviolet light is 5 minutes.