JP2000194122A - Pellicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent contamination from causing on the inner side of a pellicle frame even if long-time exposure is carried out with light of a short wavelength by providing the outer wall of the pellicle frame with a fixing means for holding the pellicle frame in tight contact on the surface of a matrix provided with a transfer pattern to a substrate. SOLUTION: An adhesive tape 13 is stuck to the outer wall of the pellicle frame 11 and the pellicle frame 11 is tightly adhered to the surface of a reticle 18 provided with the transfer pattern by this adhesive tape 13. The adhesive tape 13 for fixing the pellicle frame 11 to the reticle 18 is stuck to the outer wall of the pellicle frame 11 in the manner described above, by which the volatile component of the tacky adhesive material of the adhesive tape 13 is prevented from flowing into the inner side of the pellicle frame 11. Then, even if the long-time execute is carried out by the exposure light of the short wavelength, such as a KrF laser, the photochemical reaction of the acid remaining on the surface of the reticle 18 with the volatile component of the tacky adhesive material of the adhesive tape 13 does not occur and the contamination is not caused on the surface of the reticle 18 on the inner side of the pellicle frame 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellicle mounted on a master to prevent foreign substances from adhering to the surface of the master when a transfer pattern of the master such as a mask or a reticle is transferred to a wafer by exposure.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture a semiconductor device or the like by using a photolithography technique, a transfer pattern provided on a mask or a reticle is formed on a substrate such as a wafer through a projection optical system using a projection exposure apparatus. Transcribed to At this time, if foreign matter adheres to the surface of the master such as a mask or a reticle, the shape of the foreign matter is transferred to the substrate as a defect.

In order to prevent foreign matter from adhering to the surface of the master, a pattern is transferred by mounting a pellicle on the master. Below, about the conventional pellicle,
This will be described with reference to FIGS.

As shown in FIG. 7 and FIG.
0 is a rectangular pellicle frame 131 and this pellicle frame 13
1 has a transparent pellicle film 132 stretched over a pellicle frame 131 so as to cover an opening on the upper surface. And pellicle 1
30 is attached to the surface of the reticle 138 (or mask) provided with the transfer pattern by applying an adhesive 133 to the lower surface of the pellicle frame 131. By performing the transfer of the transfer pattern of 138, foreign matter is prevented from adhering to the surface of the reticle 138.

Although foreign matter in the air adheres to the pellicle film 132, the exposure light is focused on the surface of the reticle 138 at the time of exposure. If it is smaller than a certain size, it is not transferred to a substrate (not shown).

[0006]

However, even if the above-described pellicle is mounted and pattern transfer is performed,
When exposure is performed for a long time using a KrF laser exposure apparatus, foreign matter may be generated inside the pellicle, and the foreign matter may be transferred to a wafer to cause a defect.

Analysis of the cause revealed that the surface of the master was cleaned with, for example, a mixed solution of sulfuric acid and hydrogen peroxide before mounting the pellicle. The acid remaining on the surface of the master during this cleaning was KrF It has been found that the laser irradiation causes a photochemical reaction with the volatile components of the adhesive to generate foreign matter. Such a phenomenon was not observed in exposure using g-line or i-line. It is considered that the above-mentioned photochemical reaction was easily caused by shortening the wavelength of the exposure light. Incidentally, while the wavelength of the g-line is 436 nm and the wavelength of the i-line is 365 nm, the wavelength of the KrF laser is 248 nm.

Accordingly, an object of the present invention is to provide a pellicle in which no foreign matter is formed inside the pellicle frame even when exposure is performed for a long time with light having a short wavelength.

[0009]

In order to achieve the above object, a pellicle according to the present invention comprises a pellicle frame and a pellicle film stretched over the pellicle frame so as to cover the pellicle frame. The outer wall is provided with fixing means for holding the pellicle frame in close contact with the surface of the master on which the transfer pattern to the substrate is provided.

In the pellicle of the present invention configured as described above, the fixing means for holding the pellicle frame in close contact with the surface of the master is provided on the outer wall of the pellicle frame. Even if it is fixed using a member containing a property, the volatile component does not flow into the inside of the pellicle frame. Therefore, the acid remaining on the master during the cleaning of the master does not cause a photochemical reaction with volatile components during exposure, and no foreign matter is generated inside the pellicle frame.

As the fixing means, an adhesive tape, a band fastened to the master, a frame for holding the master sandwiched from above and below, and the like can be used. In particular, when a band or a frame is used, it is not necessary to attach a margin to the surface of the master, so that the surface of the master can be used effectively.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a plan view showing a state in which a pellicle according to a first embodiment of the present invention is mounted on a reticle, and FIG. 2 is a sectional view taken along line AA of FIG. is there.

As shown in FIGS. 1 and 2, the pellicle 10
Has a rectangular pellicle frame 11 and a transparent pellicle film 12 stretched over the pellicle frame 11 so as to cover an opening on the upper surface of the pellicle frame 11. The pellicle film 12 is made of, for example, nitrocellulose or fluoropolymer. The pellicle film solvent is applied to the pellicle frame 11, the pellicle film 12 is adhered, and then dried.

Adhesive tape 1 is provided on the outer wall of pellicle frame 11.
The pellicle 10 is mounted on the surface of the reticle 18 on which the transfer pattern is provided, with the pellicle frame 11 being in close contact with the adhesive tape 13. As the adhesive tape 13, for example, a material obtained by applying an acrylic resin as an adhesive to a base material made of polyvinyl is used, and any material having good adhesiveness to the pellicle frame 11 and the reticle 18 is used. May be used.

As described above, the pellicle frame 11 is
Since the adhesive tape 13 fixed to 8 is attached to the outer wall of the pellicle frame 11, the volatile component of the adhesive of the adhesive tape 13 does not flow into the pellicle frame 11. Therefore, even if exposure is performed for a long time with short wavelength exposure light such as a KrF laser, the reticle 18 is not cleaned when the reticle 18 is cleaned.
The acid remaining on the surface of the reticle 18 does not cause a photochemical reaction with the volatile component of the adhesive of the adhesive tape 13, and no foreign matter is generated on the surface of the reticle 18 inside the pellicle frame 11.
As a result, it is possible to transfer a good pattern having no defect due to foreign matter to a wafer (not shown).

(Second Embodiment) FIG. 3 is a plan view of a pellicle according to a first embodiment of the present invention, and FIG. 4 is a sectional view taken along line BB of the pellicle shown in FIG. 3 together with a reticle. is there.

As shown in FIG. 3, in the pellicle 20 of the present embodiment, four flexible bands 23 are attached to opposing outer walls of a pellicle frame 21 on which a pellicle film 22 is stretched. Each band 23 is attached to the corner of the pellicle frame 21 so as to face each other such that two bands are paired. In the present embodiment, the band 23 is made of polyvinyl, and is adhered to the pellicle frame 21 with an ultraviolet curable resin. However, the material of the band 23 and the method of fixing the band 23 to the pellicle frame 21 are arbitrary. can do.

As shown in FIG. 4, when the pellicle 20 of the present embodiment is mounted on the reticle 28, the tip of the band 23 is routed to the back side of the reticle 28,
While applying tension to the band 23 so that 1 is in close contact with the surface of the reticle 28, the opposing bands 23 are coupled to the reticle 28 in a tightened state. Thus, the pellicle 20 is fixed to the reticle 28. The bonding of the bands 23 can be performed, for example, by bonding using an adhesive, or by thermal welding if the band 23 can be melted by heat.

As described above, even when the band is fixed to the outer wall of the pellicle frame 21 and the pellicle 20 is mounted on the reticle 28 by the band 23, as in the first embodiment,
Generation of foreign matter inside the pellicle 20 due to the photochemical reaction can be prevented. Furthermore, in the present embodiment, the surface of the reticle 28 does not require the adhesive margin as in the first embodiment, so that the surface of the reticle 28 can be used effectively. In other words, all regions except the region where the pellicle frame 21 is placed can be used as the pattern formation region.

In this embodiment, an example is shown in which two pairs of bands 23 are used, but the number may be increased or decreased as needed.

(Third Embodiment) FIG. 5 is a perspective view showing a state in which a pellicle according to a third embodiment of the present invention is mounted on a reticle, and FIG. 6 is a view at the center of the pellicle shown in FIG. It is a longitudinal cross-sectional view.

As shown in FIG. 5, in the pellicle 30 of the present embodiment, a frame 33 is provided on a pellicle frame 31 on which a pellicle film 32 is stretched. The frame 33 holds the reticle 38 from above and below. The base 33a on which the reticle 38 is placed is connected to one end of the base 33a so as to be freely rotatable. Are provided integrally with the outer wall of the pellicle frame 31 to support the pellicle frame 31, and the supporting portion 33b is provided integrally with the pellicle frame 31 on the outer wall facing the pellicle frame 31, and the tip is a base portion 33a. And a fixing portion 33c to be fixed.

In the present embodiment, the connection between the base portion 33a and the support portion 33b is performed by the hinge 34, and the base portion 33a and the fixing portion 33c are fixed by the bolt 35. Further, a structure in which the support portion 33b and the fixing portion 33c are integrally provided on the pellicle frame 31 as described above,
In the present embodiment, the pellicle frame 31, the support portion 33b
And the fixing portion 33c is integrally formed of aluminum.

With the above structure, the pellicle frame 31 is
As shown in (a), the base is pivotally supported by the base 33a around the hinge 34 in the direction of the arrow. The base portion 33a has an L-shape when viewed from the side, and by pressing down the pellicle frame 31 with the reticle 38 placed on the base portion 33a, as shown in FIG. The pellicle frame 31 is sandwiched from above and below by the pellicle frame 31 and the base portion 33 a, and the pellicle frame 31 is in close contact with the surface of the reticle 38.

As shown in FIGS. 6A and 6B,
A bolt hole 33d through which the bolt 35 passes is provided in the fixing portion 33c.
On the other hand, a nut hole 33e into which the nut 36 is inserted is formed at the other end of the base portion 33a, and the bolt 35 is passed through the bolt hole 33d with the nut 36 inserted into the nut hole 33e. By fastening the nut 36 to the pellicle frame 31, the pellicle frame 31 can be fixed in a state of being in close contact with the surface of the reticle 38.

As described above, the frame 33 having the support portion 33b and the fixing portion 33c integrally formed with the pellicle frame 31 is used.
The pellicle frame 31 can be fixed to the surface of the reticle 38 without using any adhesive by holding the top and bottom of the reticle 8. As a result, during exposure, the reticle 3
The generation of foreign matter due to the photochemical reaction between the acid remaining on the surface of No. 8 and the exposure light can be reliably prevented. Also, in the present embodiment, since there is no need for bonding, like the second embodiment, the reticle 28 can use all the regions except the region where the pellicle frame 31 is placed as the pattern forming region. it can.

In the present embodiment, an example is shown in which the support portion 33b and the fixing portion 33c are integrally formed with the pellicle frame 31.
The support portion 33b and the fixing portion 33c are used for the pellicle frame 31.
If the support portion 33b and the fixing portion 33c are securely fixed, the pellicle frame 31 is formed as a separate member from the pellicle frame 31.
It is good also as a structure fixed to the outer wall of the. In this case, even if an adhesive is used, the support portion 33b and the fixing portion 33c are bonded to the outer wall of the pellicle frame 31, so that the volatile components of the adhesive do not flow into the pellicle frame 31.

Further, the reticle 38 is held by the bolt 35
Although the example in which the fastening is performed by fastening the reticle 38 to the nut 36 is shown, the invention is not limited to the bolt and nut as long as the reticle 38 can be sandwiched and held from above and below. However, by using a means such as a bolt and a nut that can be removed and re-mounted arbitrarily, the position of the reticle 38 can be easily corrected when the position of the reticle 38 is shifted, and the pellicle 30 can be connected to another reticle. They can be shared.

As described above, the present invention has been described with reference to the three embodiments, but the present invention is not limited to the above-described embodiments. For example, although the pellicle frame has been described as having a square shape, the shape may be any shape such as a circular shape as needed. Also, the pellicle has been described as preventing foreign matter from adhering to the surface of the reticle, but it goes without saying that the pellicle can be applied not only to the reticle but also to a mask.

[0031]

As described above, according to the present invention, the fixing means for holding the pellicle frame in close contact with the surface of the master is provided on the outer wall of the pellicle frame, so that the fixing means and the master can be made of a volatile material such as an adhesive. Even if it is fixed by using a member including a component, generation of foreign matter inside the pellicle frame due to a photochemical reaction can be prevented. Therefore, the method of fixing the fixing means and the master can be arbitrarily set, and the range of the method of attaching the pellicle to the master can be widened.
In particular, when a band or a frame is used as the fixing means, it is not necessary to attach a margin to the surface of the master, so that the surface of the master can be used effectively.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state in which a pellicle according to a first embodiment of the present invention is attached to a reticle.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of a pellicle according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of the pellicle shown in FIG. 3 together with a reticle.

FIG. 5 is a perspective view showing a state in which a pellicle according to a third embodiment of the present invention is mounted on a reticle.

FIG. 6 is a vertical cross-sectional view at the center of the pellicle shown in FIG. 5;

FIG. 7 is a perspective view of a conventional pellicle.

8 is a cross-sectional view showing a state where the pellicle shown in FIG. 7 is mounted on a substrate.

[Explanation of symbols]

 10, 20, 30 Pellicle 11, 21, 31 Pellicle frame 12, 22, 32 Pellicle film 13 Adhesive tape 18, 28, 38 Reticle 23 Band 33 Frame 33a Base 33b Support 33c Fixing 33d Bolt hole 33e Nut hole 34 Hinge 35 bolt 36 nut

Claims (7)

[Claims] 1. A pellicle having a pellicle frame and a pellicle film stretched over the pellicle frame so as to cover the pellicle frame, wherein a surface of a master having a transfer pattern to a substrate on an outer wall of the pellicle frame A pellicle provided with fixing means for holding the pellicle frame in close contact with the pellicle frame. 2. The pellicle according to claim 1, wherein said fixing means is an adhesive tape. 3. The pellicle according to claim 1, wherein said fixing means is at least a pair of bands fixed to said outer side wall of said pellicle frame and fastened to said master. 4. The pellicle according to claim 3, wherein the bands form a pair and the leading ends of the bands are connected to the back side of the master to be joined. 5. The pellicle according to claim 1, wherein the fixing means is a frame that holds the master disc from above and below. 6. The frame has a base on which the master is placed, one end of which is rotatably connected to the base, and the other end integrally provided on an outer wall of the pellicle frame. The pellicle according to claim 5, further comprising: a supporting portion provided on the outer wall of the pellicle frame, and a fixing portion fixed to the base portion. 7. The pellicle according to claim 6, wherein said support portion and said fixed portion are integrally formed with said pellicle frame.