JP2012108293A - Method for producing pellicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a pellicle preventing overflowing of an adhesive or a gluing agent from a pellicle frame and discontinuous joint of a coating, at the time of applying a pellicle film adhesive or a mask gluing agent to the pellicle frame.SOLUTION: At the time of forming a pellicle film adhesive layer 3 or a mask gluing agent layer 4 on a pellicle frame 2, a pellicle film adhesive or a mask gluing agent is applied two rounds or more on the pellicle frame 2 with one stroke.

Description

  The present invention relates to a pellicle for lithography, and more particularly to a method for manufacturing a pellicle used as a dust prevention when manufacturing a semiconductor device such as an LSI or a VLSI or a liquid crystal display panel.

  In manufacturing a semiconductor device such as an LSI or a super LSI or a liquid crystal display panel, there is a step of performing patterning by irradiating a semiconductor wafer or a liquid crystal original plate with light. At that time, a method of using a pellicle in which a pellicle film that transmits light for exposure well is attached to the surface of the exposure original plate to prevent dust is used.

  A conventional general pellicle is shown in FIG. In FIG. 1, reference numeral 1 denotes a pellicle film, and a pellicle film 1 is stretched on a pellicle frame 2 via a pellicle film adhesive layer 3. Reference numeral 4 denotes a mask adhesive layer, which is provided to fix the pellicle on the exposure original plate.

  Normally, a pellicle has a transparent pellicle film made of nitrocellulose, cellulose acetate, fluororesin, etc. that allows light to pass well, and an acrylic resin, epoxy resin, fluororesin, etc. on the upper surface of a pellicle frame made of aluminum, stainless steel, polyethylene, etc. Adhesive layer is used, and an adhesive layer made of polybutene resin, polyvinyl acetate resin, acrylic resin, silicone resin, etc. and a release layer (separator) that protects the adhesive layer are laminated on the lower surface of the pellicle frame. ing. A number of methods for manufacturing a pellicle have been reported (see, for example, Patent Documents 1 and 2).

JP-A-5-323584 JP-A-6-266098

  In general, when a pellicle film adhesive layer or a mask pressure-sensitive adhesive layer is formed on a pellicle frame, the pellicle film adhesive or mask pressure-sensitive adhesive is ejected from a needle having an appropriate diameter to draw a stroke on the upper end surface or lower end surface of the pellicle frame. Apply by writing.

  At this time, when the pellicle film adhesive layer is formed, the pellicle film adhesive is applied so that the pellicle film adhesive is overlapped with the adhesive at the beginning of the application so that the adhesive is not interrupted. If the amount is too large, the adhesive may protrude from the end surface of the pellicle frame and spill on the side surface. If the overlap is too small, the coating may become discontinuous. In this case, there arises a problem that the closed space of the pellicle formed between the pellicle film and the exposure original plate cannot be completely sealed (air pass state).

  In particular, considering the function of the pellicle that protects the pattern surface of the mask from surrounding foreign matters, the seam of the pellicle film adhesive application becomes discontinuous, and the state where the pellicle closed space cannot be completely sealed becomes a big problem. This problem is the same when a mask adhesive layer is formed using a mask adhesive.

  The present invention has been made in view of the above problems, and when the pellicle film adhesive layer or the mask pressure-sensitive adhesive layer is formed on the pellicle frame, when the pellicle film adhesive or the mask pressure-sensitive adhesive is applied to the pellicle frame, It is an object of the present invention to provide a method for producing a pellicle in which the pellicle film adhesive or the mask adhesive does not protrude from the pellicle frame and the coating seam is not discontinuous.

  The pellicle manufacturing method of the present invention is such that when a pellicle film adhesive layer or a mask pressure-sensitive adhesive layer is formed on a pellicle frame, the pellicle film adhesive or mask pressure-sensitive adhesive is continuously applied to the pellicle frame two or more times with a single stroke. It is characterized by doing. In this case, the viscosity of the pellicle film adhesive or mask adhesive used for coating is preferably in the range of 0.01 to 100 Pa · s at room temperature.

  According to the method for producing a pellicle of the present invention, it is possible to avoid a problem that the pellicle film adhesive or the mask pressure-sensitive adhesive protrudes from the pellicle frame or the joint between the pellicle film adhesive layer and the mask pressure-sensitive adhesive layer becomes discontinuous. The pellicle closed space can be completely sealed.

It is a longitudinal cross-sectional view which shows the outline of the conventional common pellicle. The state when there are too few pellicle film adhesives or mask adhesives applied on the pellicle frame by a prior art is shown, (a) is a top view, (b) is a side view. The state when there are too many pellicle film adhesives or mask adhesives apply | coated on the pellicle frame by a prior art is shown, (a) is a top view, (b) is a side view. It is a side view which shows the state which apply | coated the pellicle film | membrane adhesive agent or the mask adhesive on the pellicle frame with the manufacturing method of this invention.

When applying a pellicle film adhesive or a mask adhesive (hereinafter referred to as “pellicle film adhesive”) on the pellicle frame, the liquid pellicle film adhesive is usually put in a cartridge or continuously supplied. Then, the adhesive is discharged onto the end surface of the pellicle frame from a needle having a diameter equal to or slightly smaller than the width of the coated surface of the pellicle frame.

Usually, the pellicle film adhesive is started to be applied from a certain location on the pellicle frame, and the seam of the adhesive does not become discontinuous by making a round and slightly overlapping the coating end portion with the coating start portion. However, if the liquid amount of the adhesive at the beginning or end of coating changes, for example, if the amount of the adhesive at the end of coating is too small, as shown in FIG. The film adhesive layer 3 becomes discontinuous without overlapping the pellicle film adhesive layer 3 at the start of application. 2A is a view of the coated surface as viewed from above, and FIG. 2B is a view of the coated surface as viewed from the side.
Also, when the amount of the adhesive at the end of coating is too large, as shown in FIG. 3, the amount of liquid is too large at the overlap between the end of coating and the beginning of coating, and the adhesive is removed from the pellicle frame. It may overhang. 3A is a view of the coated surface as viewed from above, and FIG. 3B is a view of the coated surface as viewed from the side.

On the other hand, when the pellicle film adhesive is continuously applied two or more times with a single stroke as in the method of the present invention, it is continuously applied at least once at the beginning or end of the application. Therefore, even if the liquid amount at the beginning or the end of coating varies, the seam of the pellicle film adhesive layer does not become discontinuous. How many times the pellicle film adhesive is applied may be appropriately determined in consideration of the application amount of the pellicle film adhesive, the width of the pellicle frame, the discharge amount from the needle, and the like. The amount of the pellicle film adhesive applied may be determined as appropriate so that the pellicle film adhesive does not protrude from the pellicle frame. In the method of the present invention, the continuous application of two or more rounds of the pellicle film adhesive is further performed on the pellicle film adhesive applied first, as shown in FIG.
Usually, in order to prevent the pellicle film adhesive layer from becoming discontinuous at the beginning and end of coating, the seam overlap is often slightly increased, but in the method of the present invention, there is a risk of discontinuity. Therefore, the overlap at the end of the coating can be minimized and the protrusion can be prevented.

FIG. 4 is an example in the case of applying continuously two times according to the present invention, and is a view of the joint portion at the beginning and end of coating as seen from the side. In FIG. 4, 5 is a pellicle film adhesive layer at the start of coating, 6 is a pellicle film adhesive layer that goes around once and continuously enters the second cycle, and 7 is a pellicle film adhesive layer at the end of coating. . Since the pellicle film adhesive layer 6 entering the second circumference continuously applies the seam between the pellicle film adhesive layer 5 at the start of application and the pellicle film adhesive layer 7 at the end of application, the seam becomes discontinuous. There is no.
In the method of the present invention, the viscosity of the pellicle film adhesive to be used is also important, and is preferably in the range of 0.01 to 100 Pa · s at room temperature, and in the range of 0.01 to 100 Pa · s. If it is present, it is easy to control the discharge amount from the needle, and a layer thickness preferable for stretching the pellicle film can be obtained by applying two or more rounds.
The pellicle film adhesive layer has been described above as an example, but the same applies to the case where the mask adhesive layer is formed using the mask adhesive.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these, Various aspects are possible.

[Example]
After cleaning the aluminum alloy pellicle frame (outside size 149 mm x 122 mm x 5.8 mm, wall thickness 2 mm) with pure water, the silicone adhesive “KR3700” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) with toluene and its viscosity The pressure was adjusted to 30 Pa · s (normal temperature), put in a syringe, discharged from a needle having a diameter of 1 mm, and continuously applied to one end face of the pellicle frame twice. Immediately thereafter, the pellicle frame was heated to 150 ° C. by electromagnetic induction heating.

  “Cytop CTX-A” (trade name, manufactured by Asahi Glass Co., Ltd.) as an adhesive is dissolved in perfluorotributylamine on the opposite end face of the pellicle frame to which the above-mentioned pressure-sensitive adhesive is applied, and the viscosity is 0.01 Pa · s ( A 6% solution prepared at room temperature was discharged from a needle having a diameter of 1 mm, and was continuously applied twice on the other end face of the pellicle frame. Thereafter, the pellicle frame was heated at 130 ° C. to cure the adhesive.

  A 3% solution of “Cytop CTX-S” (trade name, manufactured by Asahi Glass) dissolved in perfluorotributylamine is dropped onto the center of the silicon wafer substrate, and the silicon wafer substrate is rotated at a rotational speed of 760 rpm. The solution was developed on top to form a coating film and allowed to stand at room temperature. Thereafter, the substrate was heated to 180 ° C. to evaporate the solvent, thereby forming a pellicle film. The pellicle film was peeled from the substrate to complete the pellicle film.

The prepared pellicle film was affixed to the side of the pellicle frame where the adhesive was applied, and the portion protruding outward from the pellicle frame was removed to complete the pellicle of the present invention.
In the obtained pellicle, there was no discontinuous portion in the pellicle film adhesive layer, and the pellicle film was completely adhered over the entire periphery of the pellicle frame. Moreover, there was no protrusion from the end surface of the pellicle frame. On the other hand, there was no discontinuous portion in the mask adhesive layer, and there was no protrusion from the end surface of the pellicle frame.

DESCRIPTION OF SYMBOLS 1 Pellicle film 2 Pellicle frame 3 Pellicle film adhesive layer 4 Mask adhesive layer 5 Adhesive layer at the beginning of coating 6 Adhesive layer that enters the second round in succession 7 Adhesive layer at the end of coating

Claims (3)

When forming a pellicle film adhesive layer or a mask pressure-sensitive adhesive layer on a pellicle frame, the pellicle film adhesive or mask pressure-sensitive adhesive is continuously applied to the pellicle frame two or more times with a single stroke. Method. The method for producing a pellicle according to claim 1, wherein the viscosity of the pellicle film adhesive or the mask pressure-sensitive adhesive used for the coating is in the range of 0.01 to 100 Pa · s at room temperature. A pellicle manufactured by the method according to claim 1.

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