TWI782139B - Mask unit and exposure device - Google Patents

Abstract

It is designed so that the film photomask can be easily attached to the transparent plate, and the problem of reducing the shape accuracy of the transferred pattern can be eliminated. The film photomask (1) supported by the transparent plate (2) is vacuum-adsorbed at its periphery through the vacuum suction holes (34) of the photomask frame (3). The vent groove (21) formed on the face facing the film photomask (1) of the transparent plate (2) reaches the edge on the right side of the face, and terminates on the way of the chamfer (22). The cleaning roller (91) of the exposure device contacts the film mask (1) from the left edge to the right edge and moves while rotating to remove foreign matter (c) and air bubbles (g). ) of extrusion. The gas forming bubbles (g) is discharged through the vent groove (21) and the suction port (37).

Description

Mask unit and exposure device

The invention of this application relates to an exposure device used for pattern transfer in the manufacture of various products, and also relates to a mask unit mounted on the exposure device.

An exposure device that irradiates an object with a predetermined pattern of light to expose it is used in various applications as a core technology of photolithography. Among the exposure devices, a type that directly draws a pattern is known, but light is usually irradiated through a mask to transfer the pattern on the mask to the object.

The photomask mounted on the exposure device has a pattern drawn on a transparent glass plate with a light-shielding material. Usually, a film of a light-shielding material is attached to a glass plate and patterned by photolithography. Compared with such a mask made of glass, a so-called film mask is used more and more recently. The pattern formed by the light-shielding material is a transparent thin film formed of a material such as PET (polyethylene terephthalate) film, and a glass plate is used to support the film (film light cover) structure. In the case of thin film masks, the glass plate can be shared, and it is only necessary to manufacture and store various thin film masks according to the type. Therefore, it becomes low cost, and it is easy to store or take out. The space required for storage is also reduced. For such reasons, more and more exposure apparatuses employ thin-film masks. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 61-41151 [Patent Document 2] Japanese Patent Application Laid-Open No. 11-30851

[Problem to be solved by the invention]

Although the film photomask has the advantages as described above, it is a problem to be solved that it must be mounted on the exposure device in a state in which it is sufficiently adhered to the glass plate. Even if the thin and soft film mask is pressed against the glass plate to make it close, air bubbles are likely to remain in it. If air bubbles remain, the pattern on the film photomask will be distorted in this part, so the transferred pattern will also become distorted, which will easily become the cause of product defects.

Therefore, after pushing the film photomask onto the glass plate, it is necessary for the operator to wipe it with a spatula and squeeze out the air bubbles to the outside, which becomes an obstacle to the improvement of productivity. In addition, the film mask is deformed (stretched) when it is wiped with a spatula, and the film mask is easily adhered to and fixed to the glass plate in a distorted state. The problem is, this deformation happens randomly, so it is difficult to control. Therefore, the shape accuracy of the pattern to be transferred tends to be lowered. The invention of this application is developed to solve the unsolved problems in the above-mentioned film photomask, and the purpose is to design it so that the film photomask can be easily attached to the transparent plate, and eliminate the shape accuracy of the transferred pattern. problem of reduction. [Technical means to solve the problem]

In order to solve the above-mentioned problems to be solved, the invention described in item 1 of the scope of patent application of this case is mounted on the mask unit of the exposure device, and has the following structure, that is, it has: Thin film masks; and a transparent plate supporting a film mask; and a photomask frame to hold the transparent plate at the periphery; The photomask frame has a vacuum adsorption hole for vacuum adsorption of the film photomask, On the surface of the transparent plate facing the film photomask, there is provided a concave portion or a convex portion forming a vent space reaching one edge of the surface. In addition, in order to solve the above-mentioned problems to be solved, the invention described in item 2 of the scope of patent application has the following structure in the structure of item 1 of the scope of patent application, that is, the aforementioned photomask frame, and the aforementioned transparent plate The end face faces the inner side, and has a suction port that can be sucked by vacuum. In addition, in order to solve the above-mentioned problems to be solved, the invention described in item 3 of the scope of patent application has the following structure in the composition of item 1 of the scope of patent application, that is, it is characterized in that the aforementioned transparent plate has The oblique surface that is connected to the surface facing the above-mentioned film photomask and the end surface, that is, the chamfered portion, The above-mentioned part is a shape in the middle of the above-mentioned air leakage space reaching the chamfered part. In addition, in order to solve the above-mentioned problems to be solved, the invention described in item 4 of the scope of patent application is equipped with: a transport system to transport the substrate to the exposure operation position; and The mask unit described in any one of items 1 to 3 of the scope of the patent application is arranged at the exposure operation position; and The exposure unit exposes the substrate by irradiating light through the aforementioned film mask in the mask unit; the exposure device has the following configuration, namely, Equipped with a cleaning head and a head moving mechanism for removing foreign objects on the surface of the film photomask, The head moving mechanism is a mechanism that makes the cleaning head move while touching the film mask, and is a mechanism that moves the cleaning head from the edge of the side of the transparent plate opposite to the aforementioned side toward the edge of the aforementioned side. In addition, in order to solve the above-mentioned problems to be solved, the invention described in item 5 of the scope of patent application has the following structure in the composition of item 4 of the scope of patent application, that is, the aforementioned cleaning head is to form an adhesive layer on the surface , a cleaning roller that rotates while contacting the above-mentioned film photomask. In addition, in order to solve the above-mentioned problems to be solved, the invention described in item 6 of the scope of patent application has the following structure in the composition of item 4 of the scope of patent application, that is, the aforementioned head moving mechanism is a moving mechanism for the aforementioned cleaning head. A mechanism that decelerates the speed of movement when approaching the edge of the aforementioned side. [Efficacy of Invention]

As explained below, according to the invention described in item 1 of the patent scope of this application, the adsorption force of the edge of the side of the transparent plate facing the film mask is eased, and the gas forming the bubbles will be discharged through the air leakage space, so There will be no residual air bubbles, and the film mask will be fully adhered to the transparent plate. Therefore, there is no problem that the shape accuracy of the pattern to be transferred is lowered. In addition, according to the invention described in claim 2, the gas that escapes through the air leakage space is quickly discharged from the suction port, so the effect of preventing air bubbles from remaining is further enhanced. In addition, according to the invention described in item 3 of the scope of application, in addition to the above-mentioned effects, the air leakage space reaches the chamfered part, so the film photomask is prevented from being strongly adsorbed at the chamfered part to hinder the escape of gas. Therefore, the effect of preventing air bubbles remaining will be further enhanced. In addition, according to the invention described in claim 4, in addition to the above-mentioned effects, the cleaning head is moved by the head moving mechanism to remove air bubbles, so the removal and cleaning of air bubbles can be performed simultaneously. In addition, the stretching of the film photomask can be made reproducible, and the problem of lowering the transfer accuracy of the pattern can be avoided. In addition, according to the invention described in item 5 of the scope of patent application, in addition to the above effects, the cleaning head is a cleaning roller that rotates on the film mask, so it is not easy to apply strong force to the film mask, which is very important for preventing the film mask from deforming. It is appropriate to say. In addition, according to the invention described in claim 6 of the scope of application, in addition to the above-mentioned effects, the cleaning head will slow down when approaching the edge of one side, so there is no risk of backflow of gas, and the residual air bubbles can be further improved without reducing productivity. preventive effect.

Next, embodiments (embodiments) of the present application will be described. FIG. 1 is a schematic front sectional view of a mask unit according to an embodiment, and FIG. 2 is a schematic exploded perspective view of the mask unit in FIG. 1 . The mask unit shown in FIGS. 1 and 2 is a mask unit mounted on an exposure device. This mask unit includes a film mask 1 , a transparent plate 2 , and a mask frame 3 .

The film mask 1 is a thin transparent film made of a material such as a polyester film, and has a thickness of, for example, about 100 μm to 200 μm. Since it is mounted on an exposure device, a pattern (not shown) to be transferred is drawn on the film mask 1 . In addition, in this example, the thin film mask 1 is square.

The transparent plate 2 is a member that supports the film mask 1 so as to maintain a stable shape without slack during exposure. In this embodiment, the transparent plate 2 is made of glass (glass plate). The transparent plate 2 needs to be sufficiently transparent particularly to the light of the exposure wavelength, and a glass plate commercially available under the name of a blue plate or a white plate can be used. The thickness is preferably set to about 5 mm to 10 mm from the viewpoint of ensuring mechanical strength. In addition, the transparent plate 2 is a square shape slightly smaller than the film mask 1 . In addition, as the transparent plate 2 , a material other than glass such as acrylic resin may be used.

FIG. 3 is a schematic plan view of the transparent plate 2 and the mask frame 3 viewed from the lower side. In FIG. 3 , the illustration of the film mask is omitted. The mask frame 3 is made of metal such as aluminum or stainless steel, and has a square frame shape as shown in FIGS. 2 and 3 . As shown in FIG. 1 , the inner edge of the photomask frame 3 has a height difference. The height of the step is almost equal to the thickness of the transparent plate 2 , and the transparent plate 2 is attached to the mask frame 3 with its peripheral portion within the step. Hereinafter, the surface 31 facing the end surface of the transparent plate 2 among the height differences is called an inner surface, and the surface 32 facing the plate surface of the transparent plate 2 is called a plate supporting surface.

The transparent plate 2 is fixed to the mask frame 3 at the peripheral portion by bonding. That is, as shown in FIG. 1 , an adhesive layer 20 is provided between the upper surface of the peripheral portion of the transparent plate 2 and the plate support surface 32 of the photomask frame 3 . In addition, there is a gap 30 between the end surface of the transparent plate 2 and the inner surface 31 of the mask frame 3 . Hereinafter, this gap 30 is referred to as a surrounding space.

The film photomask 1 is fixed to the transparent plate 2 and the photomask frame 3 by vacuum suction. The surface 33 of the mask frame 3 that supports the pellicle mask 1 is called a pellicle support surface. As shown in FIG. 1 , vacuum suction holes 34 are formed in the film support surface 33 . The vacuum suction hole 34 is groove-shaped, and is formed in a circumferential shape extending toward each side of the photomask frame 3 .

The vacuum suction hole 34 is connected to the tube connecting portion 36 through a communication path (not shown in detail) 35 provided in the photomask frame 3 . As shown in FIG. 1 , when the mask unit is used, an exhaust pipe 61 is connected to the pipe connection portion 36 to receive vacuum suction. In this way, the film photomask 1 will be vacuum-adsorbed to the photomask frame 3 . The vacuum suction hole 34 is a circumferential groove, so the film mask 1 is adsorbed to the mask frame 3 in a circumferential shape. In addition, on the inner surface 31 of the mask frame 3 , a suction port 37 is formed, and the suction port 37 is connected to the communication path 35 in the mask frame 3 . Therefore, the surrounding space 30 is also subjected to vacuum exhaust to become a negative pressure.

In this embodiment, the mask unit is used in a horizontal posture, and the film mask 1 is held on the lower side of the transparent plate 2 by vacuum suction. Hereinafter, for convenience of description, the surface of the transparent plate 2 on the film mask 1 side is called the front surface, and the opposite side thereof is called the back surface.

The mask unit of such an embodiment has a structure for preventing the above-mentioned generation of air bubbles. Specifically, as shown in FIGS. 1 and 2 , grooves 21 are formed on the surface of the transparent plate 2 . The groove 21 is used to form a space for gas to escape (hereinafter referred to as a gas leak space) so as not to form air bubbles between the film mask 1 and the transparent plate 2 . Hereinafter, this groove 21 is called a vent groove.

As shown in FIG. 2 , a plurality of air release grooves 21 are provided, and each air release groove 21 reaches the edge of the right side of the surface of the transparent plate 2 . The direction in which each vent groove 21 extends is parallel to the direction in which the sides of the transparent plate 2 extend toward the left and right. The left end of each vent groove 21 is the position that is also largely leaning to the right side than the center of the transparent plate 2 . That is, each vent groove 21 is formed across a margin area at the right end of the surface of the transparent plate 2 . In addition, such a venting mechanism 21 can be formed by grinding or chemical etching when the transparent plate 2 is a glass plate. When the transparent plate 2 is made of resin, it can be realized by the shape of the mold used for molding.

In addition, as shown in FIG. 1 , a chamfer 22 is formed on the peripheral edge of the surface of the transparent plate 2 . The chamfered portion 22 is an oblique surface connecting the surface and the end surface of the transparent plate 2 . The chamfer 22 prevents the pellicle 1 from being damaged by preventing the peripheral edge of the surface of the transparent plate 2 from becoming a sharp corner. Also, as shown in FIG. 1 , each vent groove 21 reaches from the edge of the surface to the chamfered portion 22 , and terminates midway through the chamfered portion 22 .

Through the vent grooves 22, the film photomask 1 is tightly attached to the transparent plate 2 without air bubbles. Hereinafter, this point will be described with reference to FIG. 4 . FIG. 4 is a schematic front cross-sectional view showing the function of the vent groove 21. FIG. FIG. 4(A) shows the mask unit of the reference example without the vent groove 21, and (B) shows the mask unit of the embodiment.

As described above, when vacuum is exhausted from the exhaust pipe 61 , the peripheral portion of the thin film mask 1 is vacuum-adsorbed to the mask frame 3 . At this time, in order to make the film photomask 1 close to the transparent plate 2 and wipe it with a spatula to squeeze out the air bubble g, in the reference example without the air release mechanism 21, as shown in Figure 4 (A ) shows that the edge of the film mask 1 on the surface of the transparent plate 2 will be strongly adsorbed, so the air bubble g is difficult to be squeezed out. Even if it is forced to squeeze out, the bubbles will be generated (moved) to other places. The reason why the film photomask 1 will be strongly adsorbed at the edge of the surface of the transparent plate 2 is that it is close to the vacuum suction hole 34 or the suction port 37 of the photomask frame 3, so that the transparent plate 2 is sucked by the suction from the suction port 37. In particular, the space between the end surface and the inner surface 31 of the photomask frame 3 becomes negative pressure, so the peripheral edge of the surface of the transparent plate 2 is easily attracted by the film photomask 1 strongly.

On the other hand, in the structure of the embodiment with the air release groove 21, the adsorption force on the periphery of the surface of the transparent plate 2 will be relaxed, and the gas that forms the bubble g will pass through the air release groove 21 to reach the surroundings when it is wiped with a spatula. The space 30 is exhausted from the suction port 37. Therefore, as shown in FIG. 4(B) , the air bubbles g do not remain, and the film photomask 1 is in a state of being sufficiently adhered to the surface of the transparent plate 2 . In addition, the width of the vent groove 21 may be, for example, about 0.5 mm to 1 mm, and the depth may be about 0.05 mm to 0.3 mm. In addition, the length calculated from the peripheral edge is about 5 mm to 30 mm.

In the structure of the photomask unit of the above-mentioned embodiment, the vent groove 21 reaches the chamfered portion 22, which means that even if the vacuum suction force is increased to improve the fixing force of the film photomask 1, the air bubbles will not be formed. Residue occurs. This point will be described with reference to FIG. 5 . FIG. 5 is a schematic front cross-sectional view illustrating a problem related to a situation where the vent groove 21 does not reach the chamfered portion 22 .

As mentioned above, when the pellicle mask 1 is vacuum-adsorbed to the mask frame 3 , the surrounding space 30 will also become negative pressure, so the pellicle mask 1 will protrude toward the side of the surrounding space 30 and be in a slightly curved state. In this case, if the vent groove 21 terminates at the edge of the surface of the transparent plate 2 , the film mask 1 will be strongly attracted to the chamfered portion 22 and may be closed there. In this case, the gas forming the bubbles cannot flow to the surrounding space 30, and the bubbles g tend to remain as shown in FIG. 5 . On the other hand, if the vent groove 21 reaches the middle of the chamfered portion 22, the film mask 1 will not be strongly attracted to the chamfered portion 22 as shown in FIG. 4(B), and air bubbles will not remain.

However, if the vacuum suction force is not increased so much, even if the vent groove 21 does not reach the middle of the chamfered portion 22, it will not be in the state shown in FIG. 5 , and there will be no problem. Conversely, the structure in which the vent groove 21 reaches the chamfered portion 22 has the advantage of improving the vacuum suction force and further improving the fixing strength of the film photomask 1 . In addition, if this effect is to be obtained, of course, the vent groove 21 does not have to end on the way of the chamfered portion 22 , and can also continue to the boundary between the chamfered portion 22 and the end surface.

In the mask unit of the above-mentioned embodiment, the suction port 37 on the inner surface 31 of the mask frame 3 is not necessarily essential. The gas forming bubbles will leak out as long as the surrounding space 30 is not completely hermetically sealed. For example, it will be discharged from the fine hole etc. which the adhesive layer 20 which joins the transparent board 2 and the photomask frame 3 has. In addition, when the vacuum suction holes 34 for the film photomask 1 to be vacuum-suctioned are not endless, and the photomask film 1 is not vacuum-suctioned in a state where the surrounding space 30 is airtightly sealed, the gas will never Seal leaks. However, compared with these, the conductance (conductance) becomes higher in the configuration where the suction port 37 is provided for suction, so the gas is quickly discharged. Therefore, the effect of preventing air bubbles remaining will be further enhanced. In addition, when the adhesive layer 20 is provided intermittently and the gas conductivity is high, the suction port 37 may not be provided. However, since the strength will decrease after that, it is preferable to provide the suction port 37 and to arrange the adhesive layer 20 in an endless circle (non-intermittently).

Next, other shapes for forming the deflated space will be described. FIG. 6 and FIG. 7 are schematic diagrams illustrating other shapes for forming the deflated space. Among them, FIG. 6 is a schematic plan view illustrating another example of the air leakage groove 21, and FIG. 7 is a schematic side cross-sectional view illustrating an example of forming an air leakage space.

The vent groove 21 in the above-mentioned embodiment is a plurality of things scattered in the direction of one side of the surface of the transparent plate 2, and all of them are arranged at equal intervals, but as shown in Figure 6 (1), a plurality of them can also be provided. A group consisting of a plurality of vent grooves 21 arranged at narrow intervals. In addition, as shown in Fig. 6 (2) (3), it can also be a vent groove 21 with branches, and it can also be a thing with a plurality of branches. The vent groove 21 of the above-mentioned embodiment will have a shape as shown in FIG. 7(1) in a side cross-sectional view, but in addition, it may also be formed by a convex portion 23 as shown in FIG. 7(2). The situation of deflated space. In this case, the protrusion 23 may be a long shape (convex line) facing the edge of the surface of the transparent plate 2, or may be a shape in which protrusions are scattered. In addition, only one of the concave portion or the convex portion may form the bleed space, and such a shape may also be adopted.

Next, an embodiment of the invention of the exposure apparatus will be described. Fig. 8 is a schematic front view of an exposure apparatus according to the embodiment. The exposure apparatus shown in FIG. 8 includes a transport system 4 for transporting a substrate S as an exposure target, a mask unit 10 arranged at an exposure work position, and the substrate S is irradiated with the film mask 1 passing through the mask unit 10. Exposure unit 5 for light exposure. The exposure apparatus of the embodiment is, for example, an apparatus that exposes a strip-shaped flexible substrate S such as a substrate for a flexible printed circuit board. Therefore, the transport system 4 is a mechanism for transporting the substrate S in a roll-to-roll manner.

Specifically, the transport system 4 includes: a delivery-side core roller 41 around which an unexposed substrate S is wound; a delivery-side pinch roller 42 that pulls the substrate S out from the delivery-side core roller 41; and The winding-side core roller 43 on which the exposed substrate S is wound, and the winding-side pinch roller 44 which pulls out the exposed substrate S and winds the winding-side core roller 43 . In addition, the feeding direction of the substrate S by the transfer system 4 is defined as the X direction, and the horizontal direction perpendicular thereto is defined as the Y direction. The Y direction is the width direction of the substrate S. The direction perpendicular to the XY plane is defined as the Z direction.

An exposure work position is set between the sending-side pinch roller 42 and the take-up-side pinch roller 44 . The exposure device of the embodiment is a device for simultaneously exposing both surfaces of the substrate S, and the mask unit 10 and the exposure unit 5 are arranged on both sides (upper and lower in this example) of the substrate S at the exposure operation position. Therefore, there are two photomask units 10 and two exposure units 5 respectively.

The upper and lower mask units 10 and the exposure unit 5 have the same configuration, and are disposed in a vertically symmetrical manner sandwiching the substrate S at the exposure work position. That is, the mask unit 10 on the upper side is arranged in a state where the pellicle mask 1 faces downward, and a transparent plate (not shown in FIG. 8 ) supports the pellicle mask 1 on the upper side. The mask unit 10 on the lower side is arranged in a state where the pellicle mask 1 faces upward, and the transparent plate supports the pellicle mask 1 on the lower side. The apparatus is provided with an unillustrated stage (hereinafter referred to as a mask stage) on which each mask unit 10 is mounted. Each mask unit 10 is mounted on the apparatus by fixing the mask frame 3 to the mask stage.

In addition, the device is provided with a vacuum exhaust system 6 for creating a state in which the thin-film photomask 1 in each photomask unit 10 is adsorbed to the photomask frame 3 . Each exhaust pipe 61 of the vacuum exhaust system 6 is connected to the pipe connection portion 36 of each mask frame 3 as described above. The vacuum exhaust system 6 is controlled by a main controller 8 described later, but may also be manually controlled by an input from an input unit 81 of the main controller 8 . In addition, although description is omitted, marks for alignment (hereinafter referred to as mask marks) are provided on each film mask 1 .

Each exposure unit 5 includes a light source 51, an optical system 52 for irradiating light from the light source 51 to the film mask 1, and the like. The device of this embodiment is a device for performing contact exposure, and each exposure unit 5 is a unit for irradiating parallel light to each film mask 1 . Therefore, the optical system 52 includes a collimating lens. For contact exposure, each mask unit 10 is provided with a mask moving mechanism 7 . Each mask moving mechanism 7 is a mechanism for moving the mask in the Z direction, making the mask stick to the substrate S or separating it from the substrate S after exposure. In addition, each mask moving mechanism 7 also has a function of moving each mask unit 10 in the XY direction to align (position) the substrate S for alignment during exposure.

Moreover, the exposure apparatus of embodiment is equipped with the mask cleaning means which removes the foreign matter adhering to the film mask 1. The cleaning means is provided for each of the upper and lower pellicle masks 1 . Each cleaning means includes a cleaning head and a head moving mechanism that moves the cleaning head in a state of being in contact with the pellicle 1 to perform cleaning. In this embodiment, the cleaning head is a roller (hereinafter referred to as cleaning roller) 91 with an adhesive layer on the surface, and the head moving mechanism is a roller moving mechanism 92 .

The details of the roller moving mechanism 92 are omitted from the illustration, but each cleaning roller 91 is held to be driven to rotate around the rotating shaft along the Y direction. The roller moving mechanism 92 maintains the rotating shaft at both ends through bearings. The arm is a structure that connects the source of movement in the X direction and the source of movement in the Z direction (up and down). For example, it is conceivable to set a linear slide rail on the bottom plate, install a linear motor on the connecting part of the arm and the linear slide rail so as to move in the X direction while being guided by the linear slide rail, and then set an air cylinder on the bottom plate. A mechanism that moves the source of the source to move in the Z direction.

In addition, as shown in FIG. 8, the device includes a main controller 8 for controlling each part. In the main controller 8, a main sequence program (main sequence program) 82 for controlling the operation of each part of the device according to a predetermined procedure is installed. That is, the main sequence program 82 is stored in the storage unit 80 of the main controller 8 and can be executed by a processor (not shown) of the main controller 8 . In addition, the main controller 8 includes an input unit 81 for performing manual operations and the like.

Next, the operation|movement of the said exposure apparatus is demonstrated schematically. A pair of photomask units 10 are located at a standby position away from the substrate S in the Z direction. The main sequence program 82 sends a control signal to the conveying system 4, so that the substrate S is fed for a precisely prescribed stroke. After the feed is complete, perform the calibration. A mark (substrate mark) for alignment is provided on the substrate S, and the mask mark and the substrate mark of each film mask 1 are photographed with a camera not shown in the figure, and the mask moving mechanism 7 moves the mask unit 10 in accordance with the photographed data. Calibration is performed by moving in the XY direction.

After the calibration is completed, the main sequence program 82 sends a control signal to the mask moving mechanism 7 to make each mask unit 10 move toward the substrate S and stick to the film mask 1 . In this state, the main sequence program 82 operates each exposure unit 5, irradiates light through each film mask 1, and performs exposure. After exposure for a predetermined time, the main sequence program 82 sends a control signal to the mask moving mechanism 7 to move each mask unit 10 away from the substrate S and return to the original standby position. Then, a control signal is sent to the conveyance system 4, and the predetermined stroke is fed again. Thereafter, the above operation is repeated.

After repeating the above-mentioned operations, when switching to exposure for a product of a different type, an exchange operation of the film photomask 1 will be performed. The device of the embodiment has a special structure used in this exchange operation. In the following, this point will be explained. As shown in FIG. 8, in the main controller 8, a mask maintenance program 83 is built as a program for maintenance. The mask maintenance program 83 is mainly a program executed when the film mask 1 is exchanged, and can be executed by input from the input unit 81 . FIG. 9 is a schematic front view showing a mask maintenance program 83 included in the exposure device.

As mentioned above, if the type is different, a different pellicle mask 1 is required, and the pellicle mask 1 is exchanged. In this embodiment, the exchange of the film mask 1 is performed by detaching the mask unit 10 . First, the operator stops the operation of the vacuum exhaust system 6 holding the film photomask 1 and removes it from the photomask platform. Then, the previously used pellicle mask 1 is disassembled, and the pellicle mask 1 for the next type is attached to the mask frame 3 . At this time, the pellicle mask 1 is covered at a predetermined position with respect to the mask frame 3 and temporarily fixed with an adhesive tape or the like. The mask frame 3 is formed with a mark showing the mounting position of the pellicle mask 1, so it is covered and temporarily fixed as an index.

Then, the mask unit 10 with the thin film mask 1 replaced is fixed to the mask platform as before. In this state, the operator operates the input unit 81 of the main controller 8 to operate the vacuum exhaust system 6 . In this way, the film photomask 1 will be vacuum-adsorbed to the photomask frame 3 . In this state, the operator operates the input unit 81 to execute the mask maintenance program 83 .

The mask maintenance program 83 is programmed to send a control signal to the roller moving mechanism 92 so as to control the movement of each cleaning roller 91 at a prescribed speed in each prescribed direction while contacting each film photomask 1 . The pair of cleaning rollers 91 are vertically symmetrical, and the actions of the mask maintenance program 83 are also vertically symmetrical. As an example, the operation of the cleaning roller 91 on the upper side is as shown in FIG. 9 .

As shown in FIG. 9(1), the roller moving mechanism 92 raises the cleaning roller 91 so that the cleaning roller 91 on the upper side abuts against the film photomask 1 at the starting position on the left side of the film photomask 1 set on the upper side. . The starting position is a position corresponding to the left edge of the transparent plate 2 in the X direction. The roller moving mechanism 92 moves the cleaning roller 91 toward the right edge from the start position ( FIG. 9( 2 )). The roller moving mechanism 92 makes the cleaning roller 91 move to the end position set on the right side of the film photomask 1. Once the end position is reached, it will be lowered by a predetermined distance and returned to the left side as shown in Figure 9 (3). original standby position. The end position is a position corresponding to the right edge of the transparent plate 2 in the X direction. Sequence program sends control signal to the cylinder moving mechanism 92 to make the cleaning cylinder 91 do such an action.

During the above actions, the cleaning roller 91 is driven to rotate by friction with the film mask 1 . Then, the foreign matter c on the surface of the film mask 1 is removed by the adhesive layer on the surface. Also, as shown in FIG. 9 , the gas forming bubbles g existing between the film mask 1 and the transparent plate 2 is squeezed out by the cleaning roller 91 . At this time, as mentioned above, the gas will be squeezed out rapidly through the air leakage groove 21 .

The important point in the above-mentioned action is that the cleaning roller 91 abuts against the film photomask 1 at the edge (starting position) on the side opposite to the side where the air release groove 21 is provided, and faces the edge (end position) on the side where the air release groove 21 is provided. move. If this action is reversed, there will be no air leakage groove 21 at the end point where the cleaning roller 91 squeezes out the gas, so the gas will flow backward and the air bubbles g will easily remain.

As can be seen from the above description, the mask maintenance program 83 in the embodiment realizes the function of cleaning the film mask 1 and removing air bubbles at the same time. Air bubbles can be removed by the mask maintenance program 83, so the operator does not need to manually remove air bubbles when exchanging the film mask 1. Therefore, the replacement work of the film photomask 1 is completed in a short time as a whole. This means that the operation stop time of the device is shortened, which contributes to the improvement of productivity.

In addition, when the cleaning roller 91 squeezes out the gas that forms the bubbles, the film mask 1 will be slightly stretched. Although this can be said to be that the film photomask 1 is twisted, the stretching of the film photomask 1, if the pushing force of the cleaning roller 91 for the film photomask 1 is constant and the moving speed of the cleaning roller 91 is constant, then the film photomask 1 The stretching of is also constant. That is to say, the stretching of the film mask 1 is reproducible and controllable. Therefore, it is possible to take measures such as forming the pattern of the film mask 1 in consideration of the stretching, and avoid the occurrence of the problem of lowering the transfer accuracy of the pattern.

In addition, according to the research of the inventor, the moving speed of the cleaning roller 91 is preferably reduced when approaching the edge of the side where the air leakage groove 21 is provided. Its reason is that if the cleaning roller 91 approaches the edge on the side where the air release groove 21 is provided, the pressure of the gas forming the bubbles tends to become higher. If the pressure becomes higher to a certain extent before reaching the air release groove 21, then It may cause the gas to pass through the abutting part of the cleaning roller 91 toward the film mask 1 and gas out. Therefore, for the cleaning roller 91, it is preferable to perform speed control such that the speed is first set to a high speed and then set to a low speed. This speed control is also realized by the sequence of the mask maintenance program 83 . In addition, although it is also possible to set it to a low speed from the beginning, it takes a long time and there is a problem that productivity falls. To reveal an example of the speed, the speed (linear speed) of the cleaning roller 91 is about 100-150 mm/sec at first, and then decelerates to about 1-10 mm/sec at the position of the air release groove 21 or slightly in front of it.

Since each cleaning roller 91 is repeatedly used, it will be in a state where many foreign substances are attached, so it is configured to be replaced with a new one or to transfer foreign substances to a transfer roller provided separately. The transfer roller is provided near the stand-by position of each cleaning roller 91 , and is made as a roller having a higher adhesive force than that of each cleaning roller 91 . The transfer roller is configured to be driven to rotate, and is configured to rotate while contacting each cleaning roller 91, so that foreign matter on each cleaning roller 91 is transferred to itself.

In the configuration of the exposure apparatus described above, the vent space in the mask unit 10 is not limited to the vent groove 21, and various configurations as shown in FIG. 6 or FIG. 7 can be employed. In addition, although the cleaning head is a cleaning roller 91, a non-roller-shaped cleaning head (such as a spatula-shaped object) can also be used. However, if a cleaning roller that rotates on the pellicle mask 1 is used, it is difficult to apply strong force to the pellicle mask 1, which is suitable for preventing deformation of the pellicle mask 1 . In addition, as for the cleaning head, there are cases where the foreign matter is not removed by adhesive force, but the foreign matter is swept out and removed, and there is also a case where the foreign matter is adsorbed by static electricity.

In addition, in the photomask unit 10, the fixing of the transparent plate 2 of the photomask frame 3 may not be adhesive but other methods such as screw fastening. For example, a member for clamping the transparent plate 2 may also be provided, and the member is screwed to the photomask frame 3 so as to be fixed. However, in the case of a contact method or a proximity method, it is preferable that there is no member protruding from the film photomask 1 on the front side (the side of the substrate S) of the film photomask 1. In this regard, the adhesive layer 20 caused by the fixation is suitable.

As an embodiment of the exposure apparatus, it is not necessarily limited to one that performs exposure on both sides, and one that exposes only one side of the substrate S may be used. In this case, the mask unit 10 is provided only on one side of the substrate S, and one cleaning roller 91 for cleaning and removing air bubbles is provided for one film mask 1 . The object to be exposed may not be the strip-shaped substrate S as described above, but a square substrate may be used as the object, or a non-flexible rigid substrate may be used as the object to be exposed. Therefore, as the conveyance method of the substrate, in addition to the roll-to-roll method, single-sheet conveyance may also be used. In the case of a monolithic device, a stage facing the pellicle mask is provided, and a substrate is placed on the stage. Then, the photomask unit or platform moves to make the substrate close to the state of the film photomask for exposure. In addition, the method of exposure may be a proximity method or a projection exposure method in addition to the contact method.

1‧‧‧Thin film mask 2‧‧‧Transparent board 21‧‧‧Discharge ditch 3‧‧‧Reticle frame 30‧‧‧surrounding space 31‧‧‧inner side 32‧‧‧Board support surface 33‧‧‧Film supporting surface 34‧‧‧Vacuum adsorption hole 35‧‧‧connected road 36‧‧‧Pipe connection 37‧‧‧Attraction port 4‧‧‧Transportation system 5‧‧‧Exposure unit 6‧‧‧Vacuum exhaust system 61‧‧‧exhaust pipe 7‧‧‧Reticle moving mechanism 8‧‧‧Main controller 83‧‧‧Reticle maintenance program 91‧‧‧Cleaning roller 92‧‧‧Drum moving mechanism

[FIG. 1] A schematic front cross-sectional view of a mask unit according to an embodiment. [Fig. 2] An exploded perspective view of the mask unit in Fig. 1. [Fig. 3] A schematic plan view of the mask frame and glass plate viewed from the bottom. [Fig. 4] A schematic front cross-sectional view revealing the function of the air vent. [FIG. 5] A schematic front cross-sectional view showing a problem in a case where the vent groove does not reach the chamfered portion. [FIG. 6] A schematic diagram showing other shapes forming the deflated space. [FIG. 7] A schematic diagram showing other shapes forming the deflated space. [ Fig. 8 ] A schematic front view of an exposure device according to an embodiment. [Fig. 9] A schematic front view showing the mask maintenance program of the exposure device.

1‧‧‧Thin film mask

2‧‧‧Transparent board

3‧‧‧Reticle frame

10‧‧‧Reticle unit

21‧‧‧Discharge ditch

91‧‧‧Cleaning roller

c‧‧‧foreign matter

g‧‧‧bubble

Claims (7)

A mask unit, which is a mask unit mounted on an exposure device, is characterized by comprising: a film mask; and a transparent plate supporting the film mask; and a mask frame holding the transparent plate at the peripheral portion; The aforementioned photomask frame has a vacuum suction hole capable of vacuum-absorbing the aforementioned thin film photomask, and on the area of the aforementioned transparent plate facing the aforementioned thin film photomask and the aforementioned thin film photomask, there is provided a side that reaches the surface. Concavity or convexity of the deflated space at the edge of the The photomask unit as described in Claim 1 of the patent application, wherein the photomask frame has a suction port that can be sucked by vacuum on the inner side facing the end surface of the aforementioned transparent plate. The photomask unit described in claim 1, wherein the transparent plate has an oblique surface that connects the surface facing the film photomask to the end surface, that is, a chamfered portion, the concave portion or the convex portion, It is the shape on the way from the aforementioned air leakage space to the aforementioned chamfered portion. The mask list as described in any one of the 1st to 3rd items of the scope of the patent application element, wherein the above-mentioned concave part or convex part, on the above-mentioned opposing surface, starts from the position between the edge of the aforementioned one side and the edge of the side opposite to the edge of the aforementioned one side to the edge of the aforementioned one side, and from the position between the edge of the aforementioned one side The position between the edge and the edge of the side opposite to the edge of the one side reaches the edge of the side opposite to the edge of the one side without the concave and convex portions forming the air leakage space. An exposure device comprising: a conveying system for conveying a substrate to an exposure operation position; and a mask unit as described in any one of items 1 to 3 of the scope of the patent application, arranged at the aforementioned exposure operation position; and exposure A unit for exposing the substrate by irradiating light through the film mask of the mask unit; the exposure device is characterized in that it is provided with a cleaning head for removing foreign matter on the surface of the film mask and a head moving mechanism, and the head The moving mechanism is a mechanism that makes the cleaning head touch the film photomask while moving it, and is a mechanism that moves the cleaning head from the edge of the side of the transparent plate opposite to the side toward the edge of the side, The above-mentioned concave part or convex part, on the surface of the above-mentioned transparent plate facing the above-mentioned photomask frame, is from the position in the middle of the moving direction of the aforementioned cleaning head to the edge of the aforementioned side, and from the position on the middle of the moving direction of the aforementioned cleaning head The edge that reaches the side opposite to the aforementioned side does not have the concave and convex portions that form the air leakage space. The exposure device as described in claim 5 of the patent application, wherein the aforementioned cleaning head is a cleaning roller that forms an adhesive layer on the surface and rotates while touching the aforementioned film photomask. The exposure device as described in claim 5 or claim 6, wherein the head moving mechanism is a mechanism that decelerates the moving speed of the cleaning head when it approaches the edge of the one side.

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