JP4006660B2 - Pellicle mounting structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pellicle mounting structure, and more particularly, in a manufacturing process of a semiconductor integrated circuit, used in a photolithography process for optically forming a pattern on a mask on a substrate. The present invention relates to a pellicle attachment structure that is attached and covers a mask surface.
[0002]
[Prior art]
4A and 4B are explanatory views showing the configuration of a main part of a conventional pellicle mounting structure, where FIG. 5A is a plan view, FIG. 5B is a cross-sectional view, and FIG. 5 is a cross-sectional view illustrating the operation of the conventional pellicle mounting structure. is there.
4 and 5, 1 is a pellicle film (indicated by hatching in FIG. 4A), 2 is a pellicle frame, 3 is a mask, 4 is an adhesive, and 5 is a liner. A pellicle U for attaching the pellicle film 1 to the mask 3 is constituted by the pellicle film 1 and the pellicle frame 2 and the like.
[0003]
For the adhesive 4, for example, a double-sided tape is used. Generally, the pressure-sensitive adhesive is attached to both sides of a base material such as a foamable resin, and the liner 5 is attached to the pressure-sensitive adhesive until it is attached to the surface to be bonded. The attached liner 5 prevents unintentional adhesion with a nearby object and deterioration of adhesive force due to dust adhering to the adhesive surface. Also in the adhesive 4 for attaching the pellicle 1, the liner 5 is attached so as to cover the adhesive surface before the pellicle frame 2 is attached to the mask 3. Then, the liner 5 attached to the adhesive 4 is peeled off, and then the pellicle frame 2 is pressed so that the pellicle frame 2 is attached to both sides of the mask 3 via the adhesive 4 as shown in FIG. It has become.
[0004]
[Problems to be solved by the invention]
In the conventional mounting structure of the pellicle frame 2, the pellicle frame 2 is fixed to the surface of the mask 3 through the adhesive surface of the adhesive material 4 provided over the entire contact surface as described above. . Therefore, as shown in FIG. 5, the pressure-sensitive adhesive 4 usually protrudes laterally due to the pressing force at the time of attachment. For this reason, the UV light projected by the exposure apparatus goes around the adhesive 4 and acts on the adhesive 4 to become a particle generation source. In particular, when short-wavelength light such as excimer laser is used as the projection light for exposure, the tendency is strong and the quality of the transfer pattern is reduced, resulting in a decrease in wafer yield. There was a problem.
[0005]
The present invention was made to solve the problems of the conventional mounting structure of the pellicle frame, and it is possible to manufacture a high-quality wafer substrate without generation of particles by a simple mounting operation. The object is to realize a pellicle mounting structure.
[0006]
[Means for Solving the Problems]
The present invention relates to a pellicle mounting structure in which a pellicle frame is attached to a mask by bringing the other surface of the pellicle frame in which the pellicle is mounted on one surface in the thickness direction into contact with the mounting surface of the mask. A pellicle mounting structure having a plurality of mounting holes through which adhesive is injected to mount the pellicle frame to the mounting surface of the mask through the thickness direction is configured. Further, the present invention provides a pellicle mounting structure in which two pellicle frames are attached to both sides of a mask by bringing the other side of the two pellicle frames in which the pellicle is attached to one side in the thickness direction into contact with both sides of the mask. A pellicle mounting structure is provided in which a plurality of mounting holes on both sides are inclined in a symmetric direction with respect to the mask. Furthermore, a pellicle mounting structure in which the adhesive reservoir is provided at the deepest part of the mounting hole is configured.
[0007]
The pellicle frame on which the pellicle is stretched is pressed against the surface of the mask while positioning. With the pellicle frame pressed, adhesive is successively injected into the mounting holes at the four corners. The injected adhesive is dried and solidified in the attachment hole, and the pellicle frame is attached to the surface of the mask. Also, the pellicle frame is pressed and set on both sides of the vertically erected mask. Then, the adhesive is injected from the left and right into the inclined mounting holes on both sides of the vericle frame, and quickly reaches the deepest bonding surface along the inclined mounting holes. When the reservoir portion is provided at the deepest portion, the adhesive that has flowed down is stored in the reservoir portion, and the pellicle frame is attached to both sides of the mask.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
Embodiment 1
1A and 1B are explanatory views showing a configuration of a main part of Embodiment 1 of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a cross-sectional view along A-A in FIG. FIG. 2 is a cross-sectional view showing the operation of the first embodiment. In the embodiment of the present invention, the same parts as those of the conventional apparatus are denoted by the same reference numerals, and a part of them will be described in detail.
[0009]
1 and 2, reference numeral 1 denotes a pellicle film, and 2 denotes a pellicle frame made of a substantially square aluminum alloy or the like with a pellicle film 1 stretched on the upper surface. As the pellicle film 1, a thin film made of an optically stable transparent polymer such as nitrocellulose is used. In the first embodiment, the pellicle U is configured by the pellicle film 1 and the pellicle frame 2. 3 is a mask, and pellicles U are attached to both upper and lower sides. A quartz plate or the like is used for the mask 3, and a pattern is formed on the surface. Reference numeral 6 denotes attachment holes penetrating the four corners of the pellicle frame 2, and 7 denotes an adhesive injected into the attachment hole 6. The mounting hole 6 is a round hole having a uniform hole diameter, and a quick-drying type in which the adhesive 7 is solidified and bonded instantaneously in a liquid such as epoxy is suitable.
[0010]
In the first embodiment of the present invention configured as described above, the pellicle frame 2 on which the pellicle film 1 is stretched is pressed against the surface of the mask 3 while being positioned. In a state where the pellicle frame 2 is pressed, adhesives 7 are injected one after another into the mounting holes 6 at the four corners. The injected adhesive 7 is solidified in the mounting hole 6 and the pellicle frame 2 is mounted on the mask 3. Similarly, the pellicle frame 2 with the pellicle film 1 stretched is attached to the back side of the mask 3 with the adhesive 7. The pellicle film 1 is arranged in parallel to both sides of the mask 3 via the pellicle frame 2, and surrounds the frame of the pellicle frame 2 from both sides.
[0011]
The pellicle film 1 stretched in parallel on both sides of the mask 3 via the pellicle frame 2 surrounds the pattern formation region formed on the mask 3 to perform a dustproof function. The mask 3 with the pellicle U attached to one side or both sides is set in the above-described exposure apparatus for the photolithography process. Then, UV light or the like is projected from the light source of the exposure apparatus through the optical system to the mask 3 while passing through the pellicle film 1 and the pellicle frame 2, and the wafer substrate on which the pattern formed on the mask 3 is arranged on the transmission surface side. The image is transferred onto (not shown).
[0012]
As described above, according to the first embodiment of the present invention, the conventional adhesive 5 using the liner 5 is not used. Then, since the pellicle frame 2 is fixed on the mask 3 with the adhesive 7 injected into the mounting hole 6, the adhesive 7 fits within the width of the mounting surface of the pellicle frame 2, and UV light directly touches the adhesive 7 during exposure. There is nothing. Therefore, the generation of particles based on the use of the pressure-sensitive adhesive 4 as in the conventional apparatus is eliminated, the mask 3 can be used in a stable state for a long time, and the quality of the pattern transferred to the semiconductor wafer is improved. As a result, the yield of the wafer is also improved.
[0013]
Further, since the pellicle frame 2 is directly fixed to the mask 3 as described above, the parallelism of the pellicle film 1 with respect to the mask 3 is improved, and the quality of the pattern at the time of transfer is further improved. Furthermore, the base material in the pressure-sensitive adhesive 4 is a cause of generation of foreign matters when the pellicle U is removed, and is a problem that cannot be avoided by the conventional apparatus when cleaning the mask 3. On the other hand, in the present invention using the adhesive 7, it can be easily dissolved with a solvent as compared with the pressure-sensitive adhesive 4, and cleaning of the mask 3 becomes extremely easy. In addition, the bonding area of the adhesive 7 injected into the mounting hole 6 is also much smaller than before, and in this respect, the cleaning after the removal of the pellicle frame 2 can be further facilitated.
[0014]
Embodiment 2
3A and 3B are cross-sectional views of the main part showing the configuration of Embodiment 2 of the present invention, in which FIG. 3A is a cross-sectional view in which the mask is in a vertical state, and FIG.
In FIG. 3, 8 is a reservoir provided at the deepest part of the attachment hole 6, and 9 is an attachment surface. In the second embodiment, the mounting holes 6 of the pellicle frames 2 on both sides are provided so as to be inclined in a symmetric direction with respect to the mounting surface 9 of the mask 3 at an angle θ. When attaching the pellicle U to both sides of the mask 3, the configuration of the second embodiment is utilized.
[0015]
In such a case, the mask 3 is placed upright as shown in FIG. Then, the vericle frame 2 is pressed against both sides of the vertical mask 3, and the adhesive 7 is injected into the inclined mounting holes 6 from the left and right. The injected adhesive 7 quickly reaches the deepest mounting surface 9 along the inclined mounting holes 6. In this case, if the reservoir 8 is provided at the deepest part as shown in the enlarged view (b) of the shape of the attachment hole 6, the adhesive 7 that has flowed down is stored in the reservoir 8. According to the second embodiment having such a configuration, the pellicle frame 2 can be attached to both sides of the mask 3 at the same time. Therefore, the pellicle frame 2 can be fixed easily and quickly, and the efficiency of the mounting operation of the pellicle U can be improved.
[0016]
In the first and second embodiments, the case where the pellicle frame and the mask are almost rectangular has been described as an example. However, the present invention can also be applied to a case where the pellicle frame and the mask are circular or polygonal. In the drawing of the second embodiment, the case where the inclination angles θ of the mounting holes on both sides are equal is shown. However, all the inclination angles may be different. Furthermore, the shape of the mounting hole, the type of the adhesive, and the like are not necessarily limited to the embodiment as long as the same function is possible in principle.
[0017]
【The invention's effect】
The present invention relates to a pellicle mounting structure in which a pellicle frame is attached to a mask by bringing the other surface of the pellicle frame in which the pellicle is mounted on one surface in the thickness direction into contact with the mounting surface of the mask. A pellicle mounting structure having a plurality of mounting holes through which adhesive is injected to mount the pellicle frame to the mounting surface of the mask through the thickness direction was configured. Further, the present invention provides a pellicle mounting structure in which two pellicle frames are attached to both sides of a mask by bringing the other side of the two pellicle frames in which the pellicle is attached to one side in the thickness direction into contact with both sides of the mask. A pellicle mounting structure is provided in which a plurality of mounting holes on both sides are inclined in a symmetrical direction with respect to the mask. Furthermore, a pellicle mounting structure in which the adhesive reservoir was provided at the deepest part of the mounting hole was constructed.
[0018]
As a result, the adhesive falls within the width of the mounting surface of the pellicle frame, and UV light does not directly touch the adhesive during exposure. Therefore, unlike the conventional apparatus, the generation of particles based on the use of the adhesive is eliminated, and the mask can be used in a stable state for a long time. Further, since the pellicle frame is directly fixed to the mask, the parallelism of the pellicle with respect to the mask is improved, and the pattern quality at the time of transfer is further improved. Furthermore, in the present invention using an adhesive, it can be easily dissolved in a solvent as compared with a pressure-sensitive adhesive, and the mask can be cleaned very easily. In addition, the bonding area of the adhesive injected into the mounting hole is much smaller than before, and in this respect, cleaning after removing the pellicle frame can be further facilitated.
[0019]
Therefore, according to the present invention, it is possible to provide a pellicle mounting structure having various features such as improving the quality of a pattern transferred to a semiconductor device by a simple mounting operation of injecting an adhesive.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a configuration of a main part of a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the operation of the first embodiment.
FIG. 3 is a cross-sectional view of a main part showing the configuration of the second embodiment.
FIG. 4 is an explanatory view showing a configuration of a main part of a conventional pellicle mounting structure.
FIG. 5 is a cross-sectional view showing the operation of a conventional pellicle mounting structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pellicle film 2 Pellicle frame 3 Mask 4 Adhesive 5 Liner 6 Mounting hole 7 Adhesive 8 Pool part 9 Mounting surface U Pellicle

Claims (3)

In the pellicle mounting structure in which the other surface of the pellicle frame in which the pellicle film is mounted on one surface in the thickness direction is brought into contact with the mounting surface of the mask, and the pellicle frame is mounted on the mask.
A pellicle mounting structure characterized in that a plurality of mounting holes are provided through the pellicle frame in the thickness direction and into which an adhesive is injected to mount the pellicle frame on the mounting surface of the mask . In a pellicle mounting structure in which the other pellicle frame with the pellicle film mounted on one surface in the thickness direction is brought into contact with both sides of the mask, and the two pellicle frames are mounted on both sides of the mask.
2. The pellicle mounting structure according to claim 1, wherein the plurality of mounting holes on both sides are inclined in a symmetrical direction with respect to the mounting surface of the mask.   The pellicle mounting structure according to claim 2, wherein the adhesive reservoir is provided at a deepest portion of the mounting hole.

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