JP2011095453A - Tool and method for separating pellicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple tool easily and safely separating pellicle mounted to a photo mask, and to provide a separating method. <P>SOLUTION: The mutual positional relation between the photo mask and the pellicle is fixed by the pellicle separating tool including a fixing member for the photo mask and an adhesive layer for the pellicle, and in the fixed state, a mask adhesive layer is extracted and removed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pellicle used as a dust guard when manufacturing a semiconductor device, a printed circuit board, a liquid crystal display, or the like.

  In the manufacture of semiconductors such as LSI and VLSI, or liquid crystal displays, patterns are created by irradiating light onto a semiconductor wafer or liquid crystal master, but dust adheres to the reticle or other photomask used at this time. If this is the case, the dust will absorb light or bend the light, so the transferred pattern will be deformed, the edges will be rough, the ground will be black, etc. There was a problem that was damaged.

For this reason, these operations are usually performed in a clean room, but it is still difficult to keep the photomask clean. Therefore, exposure is performed after a pellicle is attached to the surface of the photomask to prevent dust. In this case, the foreign matter does not adhere directly to the surface of the photomask but adheres to the pellicle. Therefore, if the focus is set on the pattern of the photomask during lithography, the foreign matter on the pellicle becomes irrelevant to the transfer.

  In general, a pellicle has a transparent pellicle film made of nitrocellulose, cellulose acetate, fluororesin, or the like that transmits light well, and is attached to an upper end surface of a pellicle frame made of aluminum, stainless steel, polyethylene, or the like with an adhesive. Furthermore, at the lower end of the pellicle frame, a mask adhesive layer made of polybutene resin, polyvinyl acetate resin, acrylic resin, silicone resin, etc. for mounting on a photomask, and a release sheet (separator) for the purpose of protecting the adhesive layer Is provided.

  The pellicle is usually attached to the photomask with a dedicated device or jig. The basic operation is the same in any apparatus. After adjusting the positional relationship between the pellicle and the photomask, the pellicle is attached by pressing the pellicle frame in parallel with the photomask for a certain period of time.

  The pellicle after being attached to the photomask must be peeled off if it is necessary to change the pellicle for some reason. Conventionally, as shown in FIG. 3, a peeling jig having a thin protrusion at the tip is inserted from the outside into a portion of the mask adhesive layer 33 between the pellicle frame 32 and the photomask 31, and the pellicle frame 32 is based on the principle of leverage. And a method of lifting and peeling the pellicle frame 32 by inserting a pin-shaped jig into a round hole provided on the outer surface of the pellicle frame.

These methods are simple and can easily peel off the pellicle, but because the pellicle is forcibly peeled off from the photomask surface by applying a force greater than the adhesive strength of the photomask adhesive layer, the mask adhesive layer that remains on the photomask There is a problem that the amount of residue increases and subsequent cleaning becomes difficult. Further, when the pellicle is peeled from the photomask, the mask adhesive layer is displaced and sticks onto the photomask pattern, which may damage or contaminate the pattern. In addition, in the case of a large pellicle with a long side length of the pellicle, it is impossible to peel all at once, so it must be peeled off part by part, but it is necessary to consider that the part that was peeled off does not stick again, Workability is poor.

On the other hand, there is a method of dragging and removing the adhesive layer as it is without breaking (Patent Document 1). This method is suitable because there is less residue of the adhesive layer after peeling, but it can be applied only to adhesives that do not easily break when pulled, and the pellicle frame when the adhesive layer is finally peeled off Is completely free and moves in the lateral direction, and there is a particularly high risk of damage to the pattern surface by the pellicle frame.

As described above, in any of the pellicle peeling methods, the pellicle frame needs to be fixed so as not to be displaced when peeling, but it is actually fixed so that the position does not move while peeling the pellicle. It is quite difficult. In the case of holding by hand, there is a problem in terms of reliability as well as workability.

Therefore, an apparatus for performing this peeling work has also been proposed (Patent Document 2). Fix the pellicle frame with a strong clamp and peel it off the photomask. However, the apparatus becomes very large. Therefore, until now, the method of carefully peeling the pellicle while holding it with the hand has been the mainstream, and there has been a problem that the risk of photomask damage is great and the productivity is very poor.

JP 09-068792 A JP 2009-151306 A

The problem to be solved by the present invention is a simple pellicle peeling jig and a peeling tool that can peel a pellicle attached to a photomask safely and easily in a short time without damaging the pattern surface. It is to provide a method.

  The pellicle peeling jig of the present invention includes a fixing member for fixing the jig to the photomask, and an adhesive layer (hereinafter referred to as “jig adhesive layer”) for fixing the jig to the pellicle. It is characterized by being.

  The fixing member for fixing the jig to the photomask includes a first arm having a contact surface that comes into contact with the photomask and a second arm having a pressing member. The pressing member of the second arm holds the photomask first. It is preferable that the jig is fixed to the photomask by pressing against the contact surface of one arm. It is preferable to use a screw member as the pressing member.

  The pressure-sensitive adhesive forming the jig pressure-sensitive adhesive layer is preferably a silicone resin.

  The pellicle peeling method of the present invention is a method in which the pellicle peeling jig of the present invention described above fixes the photomask and pellicle, and then pulls out and removes the mask adhesive layer between the pellicle and the photomask to peel the pellicle. is there.

By fixing the pellicle and the photomask together with the pellicle peeling jig of the present invention, the positional relationship between the pellicle and the photomask is fixed. In this state, the mask adhesive layer that adheres the photomask and pellicle is removed. Thereafter, the fixing between the photomask and the pellicle peeling jig is released, and the pellicle is removed from the photomask while being attached to the jig adhesive layer.

According to the present invention, since the position of the pellicle is held on the photomask during the mask adhesive layer removing operation, the pellicle does not come into contact with the pattern surface of the photomask and does not damage the pattern surface. Further, after the mask adhesive layer is removed, the fixing between the photomask and the pellicle peeling jig can be released, and the pellicle can be moved from the photomask to another place while being attached to the jig. Even during this movement, the pellicle does not contact the pattern surface of the photomask. Therefore, according to the present invention, it is possible to remove the pellicle safely and easily, and work can be performed in a short time without the need for manpower.

In particular, when silicone resin is used as the adhesive to form the jig adhesive layer, it can be adhered and fixed even when the pellicle film is a fluororesin, and the jig adhesive layer of the pellicle peeling tool once used can be replaced. In this case, there can be almost no residue (glue residue) after peeling.

It is a figure which shows one Embodiment of the pellicle peeling jig | tool of this invention, and its use condition, (a) is a top view, (b) is sectional drawing by the AA line, (c) is the B section enlarged view. is there. It is explanatory drawing which shows the peeling method of the pellicle of this invention. It is explanatory drawing which shows an example of the peeling method of the conventional pellicle.

  Hereinafter, although the form for implementing this invention is demonstrated, this invention is not limited to this. The present invention is particularly effective for large pellicles with a side length exceeding 500 mm, which are used in liquid crystal manufacturing applications. However, the present invention is applied to small pellicles with a side of about 150 mm used in semiconductor applications. Even if it is effective, its use is not particularly limited.

  FIG. 1 shows an embodiment of a pellicle peeling jig according to the present invention and its usage.

  As shown in FIG. 1B, the pellicle peeling jig 10 is arranged above the pellicle 12 and the photomask 11, and the both ends of the base 13 of the pellicle peeling jig are in contact with the outer periphery of the photomask 11. A first arm 14a having a contact surface and a second arm 14b having a screw member 14c as a pressing member are provided as fixing members for fixing the jig to the photomask. The first arm 14a serves as a reference for positioning the photomask, and the jig 14 is fixed to the photomask by the screw member 14c of the second arm 14b pressing the photomask against the contact surface of the first arm 14a. Is positioned.

In this embodiment, the pressing member is composed of the screw member 14c. However, any mechanism that can press the photomask can be used as the pressing member.

  A jig adhesive layer 16 is provided on the surface of the base 13 facing the pellicle 12 via a base member 17, and a handle 15 is provided on the top of the base 13.

The base 13 is preferably made of a rigid material such as an engineering plus chip or metal.

In this embodiment, the base 13 has a frame shape as shown in FIG. 1A. However, if the rigidity and adhesion area sufficient to fix and handle the pellicle 12 and the photomask 11 can be secured, the shape of the base is It can be anything. For example, a plate-shaped member may be used as the base, or a plate-shaped member attached to a frame-shaped member may be used as the base.

The jig adhesive layer 16 may be provided directly on the lower surface of the base without using the base member 17.

  In this embodiment, the photomask fixing member is arranged to fix only the short axis direction of the photomask. However, only the long axis direction or both orthogonal directions may be fixed.

  The pressure-sensitive adhesive constituting the jig pressure-sensitive adhesive layer 16 is not particularly limited, but is preferably determined in consideration of the pressure-sensitive adhesiveness to the pellicle film 12a to be bonded, and acrylic resin, epoxy resin, silicone resin, etc. can be used. However, among these, it is preferable to use a silicone resin.

  The silicone resin can be adhered and fixed even when the pellicle film is a fluororesin. Also, once the pellicle stripping jig has been used, it is necessary to peel off the pellicle film from the jig adhesive layer and replace it with a new jig adhesive layer. Since it is difficult to break when pulled, the residue (paste residue) after peeling can be almost eliminated, and workability is extremely good.

  As a method for forming the jig adhesive layer 16, an adhesive may be applied directly to the base 13, but a so-called double-sided sheet in which an adhesive layer is formed by applying an adhesive to both surfaces of a thin film such as PET in advance. It is preferable from the viewpoint of workability to cut and paste the shape into a desired size and apply it.

  The base member 17 is a plate-like member provided for the purpose of adjusting the height between the base and the pellicle frame 12b, preventing damage to the photomask 11 and the like, and adjusting the adhesive force. When the adhesion of the adhesive layer 16 to the pellicle film 12a is poor, the adhesiveness can be improved by using a soft resin such as rubber as a plate-like member, and by adjusting the size and shape. You can also adjust the adhesive strength. The base member 17 preferably has antistatic properties for the purpose of preventing electrostatic breakdown of adjacent photomasks.

  The material of the first arm and the second arm is not limited, but it should be made of resin so that it has sufficient rigidity to fix, and the photomask will not be damaged by contact. From the viewpoint of reducing as much as possible and preventing electrostatic breakdown of the pattern surface of the photomask, it is preferable to have antistatic performance, and conductive MC nylon, conductive PEEK, conductive HDPE and the like can be suitably used.

For other members constituting the pellicle peeling jig such as the base 13, the handle 15, and the jig adhesive layer as well, antistatic properties are provided for the purpose of preventing electrostatic breakdown of the photomask and preventing the operator from being charged. It is preferable to use a material having

  Next, a pellicle peeling method using this pellicle peeling jig will be described with reference to FIG.

  First, as shown in FIG. 2A, the screw member 14c of the second arm 14b is moved backward, and the handle 15 is held, and the first arm 14a is placed on the pellicle 12 while being in contact with one end of the photomask 11. To go. Then, finally, as shown in FIG. 2B, the jig adhesive layer 16 provided on the lower surface of the base 13 comes into contact with the uppermost part of the pellicle 12, that is, the pellicle film 12a, and is immediately adhered. In this state, the screw member 14c of the second arm 14b is tightened, and the pellicle peeling jig 10 is fixed to the photomask 11.

Next, the mask adhesive layer 12c is removed. In the embodiment of FIG. 2 (c-1), the mask adhesive layer 12 c is grasped and pulled out from the outside of the pellicle frame 12 b with tweezers 28. If the entire circumference is pulled out as it is, the adhesive layer is completely removed. As another method, as shown in FIG. 2 (c-2), an adhesive layer drawer 29 in which an adhesive substance 29b is attached to the surface of a thin plate 29a such as stainless steel or resin is prepared, and this is attached to the outside of the pellicle frame 12b. It is also effective to attach the mask adhesive layer 12c and pull it out to the outside. Further, when the mask adhesive layer 12c is hard and cannot be pulled out, the method shown in FIGS. 2C-1 and 2C-2 is applied while softening the mask adhesive layer 12c using a hot air gun (not shown). Good.

In this way, even if all the mask adhesive layers 12c are completely removed, the pellicle 12 does not move because it is adhered to the jig adhesive layer 16 of the pellicle peeling jig 10, and is lifted from the photomask 11. Is retained. Thereafter, as shown in FIG. 2 (d), the screw member 14c of the second arm 14b is retracted to release the fixation, and when the handle 15 is grasped and the pellicle peeling jig 10 is lifted upward, the pellicle 12 is peeled off. It is completely removed from the photomask 11 while sticking to the jig 10. During this series of operations, the pellicle 12 never contacts the photomask 11, and damage to the photomask is completely prevented. Finally, if the pellicle 12 adhered to the jig adhesive layer 16 of the pellicle peeling jig 10 is peeled off at a safe place and the jig adhesive layer 16 is attached, preparation for the next operation is completed.

Examples of the present invention will be described below, but the present invention is not limited thereto.
A pellicle peeling jig having a structure as shown in FIG. 1 was manufactured. The base 13 was made into a frame shape with an extruded hollow material of A6063 aluminum alloy having a cross section of 30 mm × 30 mm, and a first arm 14 a and a second arm 14 b made of antistatic ultrahigh molecular weight polyethylene were attached to both ends thereof. A screw member 14c made of antistatic MC nylon is attached to the second arm 14b. A handle 15 made of an antistatic resin was attached on the base 13.

  A base member 17 made of antistatic PVC was provided under the base 13. Then, a silicone adhesive (trade name: KR3700 / manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to both sides of a 100 μm thick PET film so that the film thickness is 50 μm after drying, and then heated and cured to form the shape of the base member 17 The adhesive layer 16 was formed by being cut and attached to the lower surface of the base member 17.

  The pellicle peeling jig 10 thus manufactured was fixed to the photomask 11 to which the pellicle 12 was adhered so as to be in the state of FIG. Here, the photomask 11 is made of quartz glass of 1100 mm × 1620 mm × 17 mm, the pellicle 12 has an outer dimension of 1068 mm × 1526 mm, an inner dimension of 1031 mm × 1490 mm, and a height of 8 mm, and the material of the pellicle film is a fluororesin. The pellicle frame is made of A5052 aluminum alloy, and the mask adhesive layer is made of a silicone adhesive.

  As shown in FIG. 2A, the fixing was started from a state in which the screw member 14c of the second arm 14b was retracted. After confirming that the jig adhesive layer 16 firmly adheres to the pellicle film 12a and fixes the pellicle, the screw member 14c of the second arm 14b is tightened, and the pellicle peeling jig 10 is attached to the outer shape of the photomask 11. Fixed against. Next, as shown in FIG. 2 (c-2), from the outside of the mask adhesive layer 12c, an adhesive layer drawer 29 in which a silicone adhesive 29b is applied to a 0.5 mm thick stainless steel plate 29a is inserted, and the mask adhesive layer 12c is attached. It was pulled out with adhesion. Then, it pulled out continuously and made 1 round and removed all the adhesion layers.

At this time, since the handling of the mask adhesive layer that was too long would be difficult to handle, the work was performed while cutting with a scissors to a length of 30-40 cm. In addition, an ionizer was installed above these operations so that there was no electrostatic breakdown of the photomask due to charging in all operations.

Then, after the mask adhesive layer removing operation was completed, the screw member 14c on the first arm 14b was loosened, the handle 15 was grasped by two persons, and slowly lifted upward, and the pellicle 12 was completely removed from the photomask 11.

After that, the surrounding light was turned off and darkened, and the photomask surface was inspected with a halogen lamp with an illuminance of 300,000 Lx, but the part where the mask adhesive layer was slightly adhered was dirty, especially damage such as scratches Was not found and was in a very clean state.

In addition, the adhering dirt (residue residue) could be easily removed by simply wiping the wiper with an organic solvent (trade name: Isopar E, manufactured by ExxonMobil) and wiping it lightly. These operations are very efficient because not only there is no fear of damage to the photomask but also a very large pellicle like this embodiment can be operated in about 10 minutes.

  After all the peeling operations were completed, the pellicle 12 was removed from the pellicle peeling jig 10 at a safe place away from the photomask and the jig adhesive layer 16 was replaced. It was about minutes.

[Comparative example]
A peeling operation was performed on the same pellicle and photomask as in the above example using a peeling jig 30 as shown in FIG. The peeling jig 30 is inserted into the lower end of the pellicle frame 32 to lift and peel the pellicle. The mask adhesive layer 33 is peeled off from the surface of the photomask 31 by the operation of the peeling jig 30, and the pellicle frame 32 is lifted, but not all is peeled off all around the frame. If 30 is returned, it will adhere to the photomask 31 again. Therefore, the work was performed with a small piece of the resin plate sandwiched between the peeled portions, and this was continuously peeled over the entire periphery of the pellicle.

At this time, an operator is arranged at each corner (not shown) of the pellicle frame 32 so that the pellicle frame 32 does not move on the photomask 31 and damage the surface of the photomask 31, and the pellicle frame 32 is prevented from being displaced. Worked while holding down. Then, after all of the mask adhesive layer 33 was peeled off, all the workers breathed together and slowly lifted the pellicle frame 32 from the photomask 31 and pulled it away to a safe place.

This work requires a minimum of five people, including four pellicle pressers in addition to one peeling worker, and the time required is approximately one hour, which is very unproductive. In addition, there is a possibility that the pellicle always comes into contact with the photomask, which is a very undesirable operation in terms of quality control.

DESCRIPTION OF SYMBOLS 10 Pellicle peeling jig | tool 11 Photomask 12 Pellicle 12a Pellicle film 12b Pellicle frame 12c Mask adhesion layer 13 Base 14a First arm 14b Second arm 14c Screw member 15 Handle 16 Jig adhesion layer 17 Base member

28 Tweezers 29 Adhesive layer drawer 29a Thin plate 29b Adhesive substance

30 Peeling jig 31 Photomask 32 Pellicle frame 33 Mask adhesive layer

Claims (5)

  A pellicle peeling tool used when peeling a pellicle from a photomask, comprising a fixing member for fixing a jig to the photomask and an adhesive layer for fixing the jig to the pellicle A pellicle stripping jig characterized by that.   The fixing member includes a first arm having a contact surface that contacts the photomask and a second arm having a pressing member, and the pressing member of the second arm presses the photomask against the contact surface of the first arm. The jig for peeling a pellicle according to claim 1, wherein the jig is fixed to the photomask.   The pellicle peeling jig according to claim 2, wherein the pressing member is a screw member.   The jig for peeling a pellicle according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is a silicone resin.   A method for peeling a pellicle attached to a photomask by a mask adhesive layer from the photomask, wherein the photomask and the pellicle are fixed by the pellicle peeling jig according to any one of claims 1 to 4, A method for peeling a pellicle, wherein the mask adhesive layer is pulled out and removed.

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