JP2020042105A - Pellicle frame and pellicle - Google Patents

Abstract

To provide a pellicle frame and a pellicle that enable rapid evacuation and air introduction and that easily have a configuration for ventilation.SOLUTION: A pellicle frame 1 has a rectangular shape in plan view and includes a first face 15 and a second face 17 that are provided on opposite sides in the thickness direction, and an inner peripheral face 11 and an outer peripheral face 13 that are connected to the first face 15 and the second face 17. The pellicle frame 1 has a plurality of recesses 25 that open to the first face 15 and connect the inner peripheral face 11 side and the outer peripheral face 13 side at the edge part 21.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a pellicle frame and a pellicle.

  In semiconductor manufacturing, a photomask is used in an exposure step of forming a wiring pattern on a semiconductor wafer. However, if foreign matter (particles or the like) adheres to the photomask, a defect in the wiring pattern occurs.

As a countermeasure, a pellicle provided with a transparent thin film (pellicle film) that covers the surface of the photomask is used to prevent dust.
In order to arrange the pellicle film at a predetermined distance from the photomask, a rectangular frame called a pellicle frame is used. As a member constituting the frame, a member having a small diameter such as a prism having a length of 3 mm and a width (thickness) of 2 mm is used.

  Further, the pellicle frame is provided with a small-diameter through-hole (that is, a vent) communicating the inside and the outside of the pellicle, and dust or the like enters the inside of the pellicle at an open end outside the vent. To prevent this, a filter is placed.

  In recent years, finer wiring patterns and the like have been miniaturized, and accordingly, the wavelength of exposure light has been shortened. For example, EUV exposure using EUV (Extreme Ultra Violet) light having a main wavelength of 13.5 nm is being studied.

  In this EUV exposure, the pellicle is mounted on a photomask in the atmosphere and used in a vacuum in the exposure apparatus, so that the vacuum is drawn in the exposure apparatus or the like. In a step after the evacuation, release to the atmosphere is performed (see Patent Document 1).

JP-A-2006-190902

  By the way, conventionally, since the filter is arranged so as to directly cover the opening end of the ventilation hole, there is a problem that it is not easy to perform vacuuming or opening to the atmosphere in a short time. In other words, when the above-described vacuuming or the like is performed, the pressure loss of the filter is much larger than that of the air hole, so that air is less likely to pass through the filter than the air hole. Therefore, it is not easy to perform evacuation or the like in a short time.

  As a countermeasure, Patent Document 1 discloses a technique in which a member communicating with a ventilation hole is provided so as to protrude inside or outside a pellicle frame, and a filter is disposed in the protruding portion in parallel with the pellicle film. I have.

  However, in this conventional technique, there is a problem that the inner space of the pellicle becomes small and the exposure range becomes small. Alternatively, there is a problem that the outer dimensions of the pellicle become large and the pellicle becomes large. Moreover, since the structure of the pellicle frame becomes very complicated, it is not easy to provide such a structure in the pellicle frame which is a small-diameter frame.

  Apart from this measure, it is conceivable to provide a large number of ventilation holes (that is, through holes) in the pellicle frame. However, since the thickness of the pellicle frame is usually 2 mm or less, a large number of pellicle frames having such a thickness are provided. It is not easy to provide ventilation holes.

  The present disclosure has been made in order to solve the above problems, and provides a pellicle frame and a pellicle that can be quickly evacuated or released to the atmosphere, and that can easily form a configuration for ventilation. With the goal.

  (1) A first aspect of the present disclosure has a rectangular shape in a plan view, and includes a first surface and a second surface provided on both sides in a thickness direction, and an inner peripheral surface connected to the first surface and the second surface. And a pellicle frame having an outer peripheral surface. The pellicle frame has a concave portion which is opened on the first surface and communicates between the inner peripheral surface side and the outer peripheral surface side.

  The pellicle frame of the first aspect is used as a frame constituting the pellicle. A pellicle film is stretched on the first surface side of the pellicle frame. Usually, the pellicle frame is provided with a ventilation hole communicating the inner peripheral surface side and the outer peripheral surface side of the pellicle frame. In the first aspect, however, the recess communicates the inner peripheral surface side with the outer peripheral surface side. By doing so, it has a function as a ventilation hole.

  Therefore, by setting the size of the concave portion (that is, the cross-sectional area of the flow path connecting the inner peripheral surface side and the outer peripheral surface side: the cross-sectional area perpendicular to the flow direction) to a required size, the inside of the pellicle frame is Sufficient ventilation can be ensured between the peripheral surface side and the outer peripheral surface side. When the cross-sectional area of the flow path is the same along the flow direction, the state of the flow of air or the like can be adjusted by the area of the opening end (opening area) of the flow path.

  Therefore, for example, when the inside of the pellicle is evacuated (that is, when evacuating), the evacuation can be performed in a short time. The same applies to the case where the atmosphere is introduced from the outside of the pellicle into the inside of the pellicle, and the atmosphere can be opened in a short time.

  Further, in the first aspect, the inner space of the pellicle is not reduced unlike the related art, so that the exposure range is not reduced. Alternatively, there is no problem that the outer dimensions of the pellicle are increased and the pellicle is enlarged.

  In addition, since the concave portion can be formed by making a cut in the pellicle frame, for example, the pellicle frame which is a frame having a smaller diameter than the through hole can be easily provided. Also, a large number of recesses can be easily formed. In addition, by adjusting the size and the number of the concave portions, the strength of the pellicle frame can be sufficiently ensured.

(2) In the second aspect of the present disclosure, in the longitudinal direction of each side of the pellicle frame, the length L of the first opening end that opens on the first surface side of the concave portion, and the length from the bottom surface of the concave portion to the second surface. The shortest distance d may satisfy the relationship of L / d ² ≦ 3.0.

In the second aspect, as is apparent from an experimental example described later, when the pellicle frame satisfies the relationship of L / d ² ≦ 3.0, the deformation amount (that is, the elasticity) when the pellicle frame is manufactured. Therefore, the pellicle frame has high flatness.

  Note that the side of the pellicle frame indicates a frame corresponding to each side of the pellicle frame having a rectangular outer shape (the same applies hereinafter). In addition, the opening end indicates a portion of the concave portion that is open on the surface of the pellicle frame (that is, a region on the outermost surface). When the length of the open end differs depending on the position (for example, when the shape of the open end is distorted), the maximum length can be adopted as the length of the open end (the same applies hereinafter).

(3) In the third aspect of the present disclosure, the ratio S / V of the total area Smm ² of the second opening end that opens to the outer peripheral surface side of the concave portion and the volume Vmm ^{3 of the} internal space surrounded by the pellicle frame is 0.1. It may be not less than 008 mm ^{-1 and not} more than 0.020 mm ^-1 .

In the third aspect, when the ratio S / V (opening area ratio) is 0.008 mm ^-1 or more and 0.020 mm ^-1 or less, evacuation and release to the atmosphere can be performed in a short time.
The total area Smm ² of the second opening end on the outer peripheral surface side (that is, the opening portion of the concave portion that opens on the outer peripheral surface side) refers to each opening opening on the outer peripheral surface of each concave portion when there are a plurality of concave portions. It is the sum of the area of the parts (ie, the opening area) (ie, the total opening area). Here, it is assumed that the cross-sectional area of the flow path of the concave portion is constant in the flow path direction.

  (4) In the fourth aspect of the present disclosure, when viewed from the inner peripheral surface side and / or the outer peripheral surface side, the shape of the concave portion is a rectangle, a trapezoid, a polygon, a part of a circle, and a part of an ellipse. May be one of these shapes.

The fourth aspect exemplifies a preferable shape of the concave portion.
(5) In the fifth aspect of the present disclosure, in the longitudinal direction of each side of the pellicle frame, the length of the concave portion along the longitudinal direction of the first opening end on the first surface side is equal to the longitudinal direction of the bottom of the concave portion. It may be larger than the length along.

  As described above, when the length of the first opening end on the first surface side of the concave portion along the longitudinal direction is larger than the length of the bottom portion of the concave portion along the longitudinal direction, that is, the first portion of the concave portion When the surface side is more open than the bottom (for example, when the shape of the second opening end is a trapezoid with the first surface side open), when an external force is applied to the pellicle frame, for example, the shape of the second opening end is changed. This is preferable because it is less likely to be damaged as compared with a rectangular shape.

(6) In the sixth aspect of the present disclosure, the corner at the bottom of the concave portion may have an R-chamfered R portion.
As described above, it is preferable to have the R portion at the corner at the bottom of the concave portion, since the corner is hardly damaged when an external force is applied to the pellicle frame.

(7) In the seventh aspect of the present disclosure, the pellicle frame may be made of a ceramic sintered body having conductivity.
In the case of such a configuration, the pellicle frame can be easily processed by electric discharge machining.

(8) In the eighth aspect of the present disclosure, the pellicle frame may have a Young's modulus of 300 GPa or more and a strength of 500 MPa or more.
In the case of such a configuration, the pellicle frame has a sufficient rigidity and strength, so that deformation and breakage hardly occur, which is preferable.

Here, the strength indicates a three-point bending strength at L = 30 mm specified in JIS R1601: 2008.
(9) In the ninth aspect of the present disclosure, the pellicle frame may be made of a ceramic sintered body having a thermal conductivity of 15 W / mK or more.

In the case of such a configuration, the pellicle frame has a high heat conductivity, so that the pellicle frame can be suitably prevented from being deformed due to a rise in temperature during the above-described exposure.
(10) In the tenth aspect of the present disclosure, the pellicle frame may be made of a ceramic sintered body having a coefficient of thermal expansion of 10 ppm / ° C. or less.

In such a configuration, deformation of the pellicle frame due to a rise in temperature during exposure can be suitably suppressed.
The coefficient of thermal expansion is a coefficient of linear thermal expansion in a temperature range from room temperature (25 ° C.) to 600 ° C.

(11) An eleventh aspect of the present disclosure relates to a pellicle provided with the pellicle frame according to any one of the first to tenth aspects, and a pellicle film disposed on the first surface side of the pellicle frame.
In the pellicle, a first opening end on the first surface side of the concave portion of the pellicle frame is covered with a pellicle film.

The pellicle according to the eleventh aspect has an effect obtained by using the pellicle frame described above.
(12) In the twelfth aspect of the present disclosure, the second opening end on the outer peripheral surface side of the concave portion of the pellicle frame may be covered with a filter.

This filter can prevent dust and the like from entering the inside of the pellicle.
<The configuration of the present disclosure will be described below>
As the material of the pellicle frame, a conductive or non-conductive material can be adopted. For example, as a material for forming the pellicle frame, a material mainly composed of ceramics can be used. In addition, the main component indicates the largest component amount (for example, weight%).

  For example, as the conductive material, alumina / titanium carbide, alumina / titanium carbide / titanium nitride, zirconia / titanium carbide, carbide, cermet, and the like can be used. Further, a metal (e.g., an alloy) such as duralumin can be employed.

  When the material forming the pellicle frame is a conductive material, the outer shape of the pellicle frame, a concave portion, a bottomed hole, or the like is formed by electric discharge machining (for example, wire electric discharge machining, fine hole electric discharge machining, die-sinking electric discharge machining, etc.). Can be easily processed into a desired shape.

In addition, as the non-conductive material, for example, ceramics such as alumina, silicon nitride, and zirconia can be adopted.
As the dimensions of the pellicle frame, both the width and the thickness of the frame portion can be, for example, in the range of 2.0 mm to 5.0 mm. As the size of the opening (center through hole), for example, a range of 120 mm to 150 mm in length and 150 mm to 120 mm in width can be adopted.

FIG. 2 is a perspective view illustrating a pellicle frame according to the first embodiment. It is sectional drawing which shows the cross section which fractured | ruptured the pellicle frame of 1st Embodiment along XY plane. It is the front view which looked at a part of 2nd side part in which the crevice was provided of the pellicle frame of a 1st embodiment from the peripheral face side. 4A is a front view of a part of the fourth side of the pellicle of the first embodiment viewed from the outer peripheral surface side, and FIG. 4B is a plan view of a part of the fourth side of FIG. 4A viewed from the first surface side. FIG. 4C is a plan view showing the pellicle film attached to the support frame. It is a flowchart showing a manufacturing method of a pellicle frame of a 1st embodiment. It is the front view which looked at a part of 4th side in which the crevice was provided of the pellicle frame of a 2nd embodiment from the peripheral face side. FIG. 7A is a front view of a part of the fourth side of the pellicle frame in which the recess is provided according to the third embodiment viewed from the outer peripheral surface side, and FIG. 7B is a fourth embodiment in which the pellicle frame of the fourth embodiment in which the recess is provided. FIG. 7C is a front view in which a part of the four sides is viewed from the outer peripheral surface side, and FIG. 7C is a front view in which a part of the fourth side in which the concave portion of the pellicle frame of the fifth embodiment is provided is viewed from the outer peripheral surface side. . FIG. 8A is an explanatory diagram showing a polished state of a beam member used in an experimental example, and FIG. 8B is an explanatory diagram showing that the beam member is deformed by polishing.

Hereinafter, embodiments of a pellicle frame and a pellicle of the present disclosure will be described with reference to the drawings.
[1. First Embodiment]
[1-1. overall structure]
First, the overall configuration of the pellicle frame of the first embodiment will be described.

  As shown in FIGS. 1 and 2, the pellicle frame 1 is a member in which a pellicle film 3 (see FIG. 4) is stretched on one side (upper side in FIG. 1). The pellicle frame 1 is made of a material mainly composed of ceramic (for example, a conductive ceramic mainly composed of alumina and containing titanium carbide). That is, the pellicle frame 1 is, for example, a conductive ceramic sintered body mainly composed of alumina.

1 and 2 show the pellicle frame 1 itself, and FIG. 4 described later shows a pellicle 7 having the pellicle film 1 and the filter 5 in the pellicle frame 1.
Hereinafter, of all the surfaces of the pellicle frame 1, the inner surface surrounded by the pellicle frame 1 itself is referred to as an inner peripheral surface 11, and the outer surface opposite to the inner side is referred to as an outer peripheral surface 13. Further, of the surfaces connected to the inner peripheral surface 11 and the outer peripheral surface 13, the side on which the pellicle film 3 is stretched is the upper surface (for example, the first surface) 15, and the opposite surface is the photomask (not shown). It is referred to as a lower surface (for example, a second surface) 17 to be attached.

  As shown in FIG. 1, in a coordinate system of orthogonal X-axis, Y-axis, and Z-axis, the pellicle frame 1 is a rectangular (ie, rectangular) frame (that is, an annular member) in plan view when viewed from the Z direction. ), And has a rectangular central through hole 19 in the center in plan view.

  In other words, the pellicle frame 1 is composed of long frame portions arranged on the same plane in four directions, up, down, left, and right in a plan view. Specifically, the pellicle frame 1 includes a first side 21a and a second side 21b arranged parallel to the X axis, and a third side 21c and a fourth side 21d arranged parallel to the Y axis. It is configured. The dimensions of the first side 21a and the second side 21b are shorter than the third side 21c and the fourth side 21d. The first to fourth sides 21a to 21d are collectively referred to as sides 21.

  The outer dimensions of the pellicle frame 1 are, for example, 149 mm in length (Y direction) × 115 mm in width (X direction) × 1.8 mm in thickness (Z direction), and the inner diameter of the pellicle frame 1 is, for example, vertical ( It is 145 mm in width (Y direction) × 111 mm in width (X direction) × 1.8 mm in thickness (Z direction).

Therefore, the volume (volume) V of the internal space NK of the pellicle frame 1 is, for example, 28971 mm ³ . Here, the volume V of the internal space NK is defined as the space V surrounded by the pellicle frame 1 (that is, the inner peripheral surface 11 thereof) when it is assumed that the pellicle frame 1 is not provided with a concave portion 25 described later. Volume.

Each side 21 of the pellicle frame 1 is a quadrangular prism, and its width dimension (width dimension viewed from the Z direction: frame width) is the same (for example, 2 mm).
Although not shown, corners of the outer periphery and the inner periphery of the pellicle frame 1 from the Z direction are rounded and smoothly curved.

  Further, the pellicle frame 1 has a Young's modulus of 300 GPa or more and a strength (three-point bending strength specified in JIS R1601: 2008) of 500 MPa or more. Furthermore, the pellicle frame 1 has a thermal conductivity of 15 W / mK or more, and a thermal expansion coefficient of 10 ppm / ° C. or less in a temperature range from room temperature (25 ° C.) to 600 ° C. The flatness of the pellicle frame 1 on the first surface 15 and the second surface 17 is 10 μm or less.

  Further, as shown in FIG. 1, the pellicle frame 1 has two portions (total) on the outer peripheral surface 13 side of both frame portions (that is, the third side portion 21 c and the fourth side portion 21 d of the long side) in the X direction. At four locations), bottomed holes 23 are formed.

  The bottomed hole 23 is, for example, a round hole with a bottom having a diameter of 1.5 mm and a depth of 1.2 mm, and the bottom is arranged in a conical shape. In addition, the bottomed hole 23 is used for a positioning part when manufacturing the pellicle 7 and for attaching the pellicle 7 to a photomask thereafter and a gripping part when transporting.

[1-2. Configuration of Main Part of Pellicle Frame]
Next, a configuration of a main part of the pellicle frame 1 will be described.
As shown in FIGS. 1 and 2, a large number of concave portions 25 are formed on the first surface 15 of the third side portion 21 c and the fourth side portion 21 d corresponding to the long side of the pellicle frame 1.

  The concave portion 25 opens on the first surface 15 side and connects the inner peripheral surface 11 side and the outer peripheral surface 13 side. The pellicle film 3 is attached to the first surface 15 side of the pellicle frame 1. In this case, the internal space NK of the pellicle 7 and the external space GK communicate with each other to allow ventilation.

Hereinafter, the concave portion 25 will be described by taking the concave portion 25 provided in the fourth side portion 21d as an example, but since the concave portion 25 of the third side portion 21c has the same shape, description thereof will be omitted.
In the first embodiment, the concave portion 25 is formed in the third side portion 21c and the fourth side portion 21d of the pellicle frame 1, but at least one side portion 21 of all the side portions 21 has: A recess 25 may be provided.

  As shown in FIG. 3, the concave portion 25 of the pellicle frame 1 is a groove-shaped cut extending in the X direction from the inner peripheral surface 11 side to the outer peripheral surface 13 side on the first surface 15 side. Many are formed along the longitudinal direction (Y direction) of the four sides 21d. Of the concave portion 25, an opening portion opening on the first surface 15 side (that is, the first opening end 29a) has a rectangular shape in plan view, and an opening portion opening on the outer peripheral surface 13 side (that is, the second opening end 29b). ) Also have a rectangular shape when viewed from the outer peripheral surface 13 side (see FIG. 4). Therefore, the space inside the concave portion 25 is a rectangular parallelepiped.

  More specifically, as shown in FIG. 3, the dimension (that is, length: cut width) L (hereinafter referred to as L1) of the concave portion 25 in the Y direction is, for example, 1.4 mm, and the margin 27 between the concave portions 25 is set. (For example, the dimension between the concave portions 25 adjacent to each other on the first surface 15) is, for example, 0.3 mm, and the pitch L3 (that is, L1 + L2) is, for example, 1.7 mm. Note that, for example, 24 recesses 25 are provided so as to avoid the bottomed hole 23 (see FIG. 2).

  Since the thickness T of the pellicle frame 1 is, for example, 1.8 mm, the depth (cut depth) t of the concave portion 25 is set to, for example, 1.1 mm, which is smaller than the thickness T. The dimension (shortest distance) d from the surface (bottom surface) 26a of the bottom 26 of the recess 25 to the second surface 17 is, for example, 0.7 mm. Here, the depth t of the concave portion 25 is set in a range of 30 to 75% of the thickness T in order to secure the strength of the pellicle frame 1.

In the first embodiment, the length L1 of the recess 25 and the depth d (ie, the shortest distance) from the bottom surface 26a of the recess 25 to the second surface 17 are L1 / d ² ≦ 3.0. Meet the relationship.

The corners of the bottom 26 of the recess 25 (that is, the left and right ends of the bottom 26 in FIG. 3) are rounded R portions 26b.
[1-3. Pellicle]
Next, the configuration of the pellicle 7 will be described.

  As shown in FIG. 4, the pellicle 7 has a pellicle film 3 attached to the first surface 15 side of the pellicle frame 1 and an opening portion on the outer peripheral surface 13 side of the concave portion 25 (that is, the second opening on the lower side in FIG. 4B). And a filter 5 that covers the end 29b.

  The filter 5 only needs to cover the opening portion 29b on the outer peripheral surface 13 side of the concave portion 25. For example, the filter 5 may be individually arranged with respect to the opening portion 29b, or may be a plurality of opening portions 29b. May be arranged in a continuous form.

  The pellicle film 3 is, for example, a transparent film having a thickness of 47 nm. When attaching the pellicle film 3 to the first surface 15 of the pellicle frame 1, a frame-shaped support frame 33 is used as shown in FIG. 4C.

That is, a rectangular frame-shaped support frame 33 is attached to the outer peripheral edge of the pellicle film 3, and the support frame 33 is attached to the first surface 15 of the pellicle frame 1.
Note that the pellicle film 3 and the support frame 33 are attached so as to cover the opening portion (that is, the first opening end) 29a on the first surface 15 side of the concave portion 25, as indicated by oblique lines in FIG. 4B.

The filter 5 is a known filter that prevents foreign substances such as dust from flowing into the pellicle 7 fixed to the photomask, and is formed of a known material that can prevent foreign substances from flowing.
As the filter 5, for example, it is desirable to use a filter having a particle collection rate of 99.7% to 100% for particles having a particle size of 0.15 μm to 0.3 μm.

  For example, an ULPA filter (Ultra Low Penetration Air Filter) can be used. The ULPA filter is an air filter having a particle collection rate of 99.9995% or more with respect to particles having a rated air volume of 0.15 μm and an initial pressure loss of 245 Pa or less.

  Further, a HEPA filter (High Efficiency Particulate Air Filter) may be used as the filter 5. The HEPA filter is an air filter having a particle collection rate of 99.97% or more for particles having a particle diameter of 0.3 μm at a rated air volume, and having an initial pressure loss of 245 Pa or less.

  As shown in FIG. 4A, the filter 5 has a rectangular shape when viewed from the outer peripheral surface 13 side. Then, it covers the entire rectangular second opening end 29b of the recess 25, and covers the entire periphery of the second opening end 29b so that no gap is formed around the second opening end 29b.

  The filter 5 is attached around the second opening end 29b of the recess 25 by, for example, an adhesive. The upper end of the second opening end 29 b of the filter 5 is attached to the support frame 33 so that no gap is formed.

In the first embodiment, the total area (ie, the total area Smm ² ) of the respective areas (ie, the respective opening areas) of the second opening ends 29 b of all the recesses 25 and the inner peripheral surface 11 of the pellicle frame 1 are enclosed. The ratio (open area ratio: S / V) to the volume (Vmm ³ ) of the internal space NK is 0.008 mm ⁻¹ or more and 0.020 mm ⁻¹ or less.

The total area S of the second opening ends 29b of all the concave portions 25 differs depending on the shape, dimensions, and number of the second opening ends 29a of the concave portions 25, as shown in an experimental example described later.
[1-4. Manufacturing method of pellicle frame]
Next, a method for manufacturing the pellicle frame 1 will be described. In addition, the dimensions of each part are examples.
(1st process P1)
As shown in FIG. 5, first, in a first step (base preparation step) P <b> 1, powder as a raw material of the pellicle frame 1 (that is, base powder) was prepared.

  Here, the powder is a substance that is a source of a sintered body constituting the pellicle frame 1, and after sintering aids are appropriately added to raw material powders such as alumina and a conductive material, wet-mixed, and then spray-dried. It was prepared into granules of 50 μm to 100 μm by the method. Although the particle size of the raw material powder was measured by a laser diffraction / scattering method, it may be measured by a dynamic light scattering method or a sedimentation method.

More specifically, in the step of preparing the base, 63% by volume of α-alumina powder having an average particle size of 0.5 μm, 10% by volume of titanium carbide having an average particle size of 1.0 μm, and 25% by volume of titanium nitride having an average particle size of 1.0 μm A composite material consisting of a sintering aid with the remainder being MgO: Y ₂ O ₃ = 1: 1 was prepared.

Then, the composite material was wet-mixed, an organic binder for molding was added, and a composite ceramic base powder of alumina, titanium carbide, and titanium nitride was prepared by a usual spray drying method.
(2nd process P2)
Next, in a second step (molding step) P2, this powder was molded to form the original shape of the pellicle frame 1.

  Specifically, the composite ceramic base powder is formed into a frame shape having an outer dimension of about 182 mm (length) × 147 mm (width) × 6 mm (thickness) and a width of about 5 mm by a die pressing method, and a prototype (powder molded body) of the pellicle frame 1 is formed. Produced.

Here, since the outer shape of the pellicle frame 1 is reduced by about 20 to 30% by a firing step described later, the pellicle frame 1 is formed larger in advance than the pellicle frame 1 after firing. The pellicle frame 1 can have various sizes according to the size of an exposure mask in a semiconductor exposure apparatus.
(3rd process P3)
Next, in a third step (firing step) P3, after molding the powder, the powder was fired at a predetermined temperature.

More specifically, the powder compact was debindered, fired at 1700 ° C. for 3 hours in an inert gas, and fired to obtain a dense ceramic sintered body having conductivity.
The firing temperature depends on the composition of the powder, but is generally 1500 ° C. or higher. By firing, a sintered body having high Young's modulus and strength is obtained.

The dimensions (outer dimensions) of this sintered body were about 151 mm long × 122 mm wide × 5 mm thick and about 4 mm in frame width. In addition, there was a distortion of about 0.3 mm.
(4th process P4)
Next, in a fourth step (thickness processing step) P4, a thickness processing (specifically, a grinding processing) for adjusting the thickness was performed on the sintered body.

Specifically, the upper and lower surfaces (both surfaces in the thickness direction) of the sintered body were ground by the same amount using a surface grinder to be processed to a thickness of 1.9 mm. The flatness after the surface grinding was 20 μm to 40 μm.
Here, the thicknesses were made uniform except for a grinding allowance (for example, 0.05 mm to 0.10 mm) of precision plane processing (ninth step P9) described later.
(Fifth step P5)
Next, in a fifth step (inner / outer shape processing step) P5, the inner and outer shape processing was performed on the sintered body after the thickness processing.

Specifically, the inner shape and outer shape of the sintered body were processed by wire electric discharge machining so that the outer dimensions were 149 mm long × 120 mm wide and 2 mm in frame width. In other words, the outer peripheral surface of the sintered body is gripped by a holding jig (not shown), wire electric discharge machining is performed on the inner peripheral surface and the outer peripheral surface of the sintered body, and the dimensions for the inner shape and outer shape are intended. Processed to. At this time, the ridge (corner) may be rounded.
(Sixth process P6)
Next, in a sixth step (drilling step) P6, two bottomed holes 23 were formed on the opposing long sides of the sintered body by die sinking electric discharge machining.

More specifically, for the sintered body, a bottomed hole having a diameter of φ1.5 mm × a depth of 1.2 mm, for example, is formed in a portion corresponding to the outer peripheral surface 13 of the third side 21 c and the fourth side 21 d of the pellicle frame 1. No. 23 was formed.
(Seventh process P7)
Next, in a seventh step (cutting step) P6, the first surface 15 of the third side 21c and the fourth side 21d of the pellicle frame 1 is formed on the sintered body by wire electric discharge machining. A plurality of recesses 25 each having a groove shape were formed.

Specifically, the wire is moved along the cut shape of the concave portion 25, and a rectangular parallelepiped cut portion corresponding to the space is cut off in the concave portion 25.
At the time of this wire electric discharge machining, the corner at the bottom 26 of the concave portion 25 is smoothly machined to form the R portion 26b.

  In addition, since the position of the concave portion 25 in the third side portion 21c and the fourth side portion 21d is the same, the concave portion 25 in the position facing the third side portion 21c and the fourth side portion 21d using a long wire. Can be processed simultaneously.

In addition to the wire electric discharge machining, the concave portions 25 of the third side 21c and / or the fourth side 21d can be collectively processed by die sinking electric discharge machining. Alternatively, the recess 25 can be formed by machining.
(8th process P8)
Next, in an eighth step (surface treatment step of electric discharge machining surface) P8, a surface treatment was performed on the surface subjected to electric discharge machining in the above fifth to eighth steps P5 to P7 (that is, an electric discharge machining surface).

Specifically, the heat affected layer generated by electric discharge machining was removed by sandblasting. In the sandblasting process, silicon carbide abrasive grains having a particle size of # 600 (average particle size of about 30 μm) were used. The thickness of the removed layer was about 5 μm.
(9th process P9)
Next, in a ninth step (precision plane processing step) P9, the sintered body after the sand blast processing was subjected to precision plane processing.

In this precision plane processing, the sintered body was polished by 25 μm to 50 μm on each side using a diamond grindstone to a thickness of 1.8 mm and a flatness of less than 10 μm.
Through the above processing, a pellicle frame 1 containing alumina as a main component was obtained.

When the Young's modulus and the strength of the pellicle frame 1 were measured, the Young's modulus was 420 GPa and the strength was 690 MPa.
The ridge of the formed pellicle frame 1 may be subjected to brush polishing and chamfering with an R radius of 0.03 mm to 0.05 mm.

  Then, the pellicle film 3 is disposed on the first surface 15 side of the pellicle frame 1 via the support frame 33 so as to cover the entire surface of the central through hole 19 of the pellicle frame 1, and the pellicle film is formed using a well-known adhesive. 3 was attached to the first surface 15 of the pellicle frame 1 via the support frame 33. That is, the outer edges of the pellicle film 3 and the support frame 33 were attached to the first surface 15 of the pellicle frame 1.

  At this time, the first opening end 29a of each recess 25 on the first surface 15 side is opened on the first surface 15, so that the first opening end 29a of the recess 25 is covered with the pellicle film 3. become.

  Thereafter, the filters 5 were respectively attached to the pellicle frame 1 using a well-known adhesive so as to cover the second opening end 29b on the outer peripheral surface 13 side of each recess 25. That is, the outer edge portion of the filter 5 was attached around the second opening end 29b of the concave portion 25.

Thus, the pellicle 7 was able to be manufactured.
[1-5. effect]
(1) The pellicle frame 1 of the first embodiment is provided with a plurality of concave portions 25 that are open on the first surface 15 side and communicate the inner peripheral surface 11 side and the outer peripheral surface 13 side. Therefore, in the concave portion 25, sufficient ventilation can be secured between the inner peripheral surface 11 side and the outer peripheral surface 13 side of the pellicle frame 1.

  Therefore, for example, when the inside of the pellicle 7 is evacuated (that is, when evacuating), evacuation can be performed in a short time. The same applies to the case where the atmosphere is introduced from the outside of the pellicle 7 to the inside of the pellicle 7, and the opening to the atmosphere can be performed in a short time.

  In the first embodiment, the inner space NK of the pellicle 7 does not become small unlike the related art, so that the exposure range does not become small. Alternatively, there is no problem that the outer dimensions of the pellicle 7 increase and the pellicle 7 increases in size.

  Moreover, since the concave portion 25 can be formed by making a cut in the pellicle frame, the pellicle frame 1 which is a frame having a smaller diameter than the through hole can be easily provided. Further, a large number of concave portions 25 can be easily formed. In addition, by adjusting the size and number of the concave portions 25, the strength of the pellicle frame 1 can be sufficiently ensured.

(2) In the first embodiment, the length L1 of the first opening end 29a of the concave portion 25 and the shortest distance d from the bottom surface of the concave portion 25 to the second surface 17 are such that L1 / d ² ≦ 3.0. Meet the relationship.
Therefore, as will be apparent from an experimental example described later, the amount of deformation (that is, the amount of elastic deformation) when manufacturing the pellicle frame 1 is small, so that the pellicle frame 1 has a high flatness.

(3) In the first embodiment, the opening area ratio (S / V) of the total area (Smm ² ) of the second opening ends 29b of all the recesses 25 to the volume (Vmm ³ ) of the internal space NK of the pellicle frame 1 is set. ) is 0.008 mm ^-1 or 0.02 mm ^-1 or less.

Even in such a case, evacuation and release to the atmosphere can be performed in a short time.
(4) In the first embodiment, since the corner portion of the bottom portion 26 of the concave portion 25 has the R portion 26 b, it is difficult to be damaged from the corner portion when an external force is applied to the pellicle frame 1. It is.

(5) In the first embodiment, since the pellicle frame 1 is made of a ceramic sintered body having conductivity, the pellicle frame 1 can be easily processed by electric discharge machining.
(6) In the first embodiment, since the pellicle frame 1 has a Young's modulus of 300 GPa or more and a strength of 500 MPa or more, the pellicle frame 1 has sufficient rigidity and strength.

  (7) In the first embodiment, since the pellicle frame 1 is made of a ceramic sintered body having a thermal conductivity of 15 W / mK or more, it is preferable that the pellicle frame 1 be deformed due to a rise in temperature during exposure. Can be suppressed.

  (8) In the first embodiment, since the pellicle frame 1 is made of a ceramic sintered body having a coefficient of thermal expansion of 10 ppm / ° C. or less, it is assumed that the pellicle frame 1 is deformed due to a rise in temperature during exposure. It can be suppressed suitably.

[1-6. Correspondence of wording]
In the first embodiment, the first surface 15, the second surface 17, the inner peripheral surface 11, the outer peripheral surface 13, the pellicle frame 1, the concave portion 25, the side portion 21, the bottom surface 26a, the bottom portion 26, the R portion 26b, the pellicle film 3, The pellicle 7 and the filter 5 are respectively a first surface, a second surface, an inner peripheral surface, an outer peripheral surface, a pellicle frame, a concave portion, a side portion, a bottom surface, a bottom portion, an R portion, a pellicle film, a pellicle, and a filter of the present disclosure. This corresponds to an example.

[2. Second Embodiment]
Next, the second embodiment will be described, but the description of the same contents as the first embodiment will be omitted or simplified. In addition, about the structure similar to 1st Embodiment, the same number is attached | subjected.

As shown in FIG. 6, the pellicle frame 41 of the second embodiment differs from the first embodiment in the shape of the concave portion 43.
That is, in the second embodiment, the shape of the concave portion 43 on the outer peripheral surface 13 side is a trapezoidal shape. More specifically, the length L4 of the first opening end 45a on the first surface 15 side of the recess 43 along the longitudinal direction (the left-right direction in FIG. 6) is longer than the length L5 of the bottom 47 of the recess 43 along the longitudinal direction. Is also large.

  For example, the length L4 is 3.0 mm, the length L5 is 0.6 mm, and the length L6 between the concave portions 43 is 1.0 mm. Further, when the thickness T of the pellicle frame 41 is, for example, 1.8 mm, the depth t of the concave portion 43 is, for example, 1.3 mm.

Further, in the second embodiment, 36 concave portions 43 are provided in the third side portion 21c and the fourth side portion 21d which are the long sides, respectively, and the first side portion 21a and the second side portion 21b which are the short sides are provided. In the case where 26 recesses 43 are provided, the total area (each opening area) of each second opening end 45b on the outer peripheral surface 13 side of the recess 43 (total opening area: total area S) is 285. it is a 5mm ^2.

Therefore, when the volume V of the internal space NK is 28971 mm ³ , the opening area ratio (S / V) is 0.0099 mm ⁻¹ .
The second embodiment has the same effects as the first embodiment. In the second embodiment, since the first surface 15 side is an isosceles trapezoid with a wide opening, for example, the area (each opening area) of each first opening end 45a on the first surface 15 side is different from that of the first embodiment. If they are the same, there is an advantage that even if a force is applied from the outside, it is harder to break than in the first embodiment.

[3. Third to fifth embodiments]
Next, the third to fifth embodiments will be described, but the description of the same contents as the first embodiment will be omitted or simplified. In addition, about the structure similar to 1st Embodiment, the same number is attached | subjected.

As shown in FIG. 7A, the pellicle frame 51 of the third embodiment is different from the first embodiment in the shape of the concave portion 53.
That is, in the third embodiment, the shape of the concave portion 53 on the outer peripheral surface 13 side is a polygon (for example, an octagon) exceeding a quadrangle. In addition, it may be a triangle.

  The third embodiment has the same effects as the first embodiment. Further, in the third embodiment, since the angle of the bent portion is wider than 90 degrees, there is an advantage that even if a force is applied from the outside, it is hard to break.

As shown in FIG. 7B, the pellicle frame 61 of the fourth embodiment is different from the first embodiment in the shape of the concave portion 63.
That is, in the fourth embodiment, the shape of the concave portion 63 on the outer peripheral surface 13 side is a part of a circle (for example, a semicircle).

  The fourth embodiment has the same effects as the first embodiment. Further, in the fourth embodiment, since the concave portion 63 is smoothly curved, there is an advantage that the concave portion 63 is not easily damaged even when a force is applied from the outside.

As shown in FIG. 7C, the pellicle frame 71 of the fifth embodiment differs from the first embodiment in the shape of the concave portion 73.
That is, in the fifth embodiment, the shape of the concave portion 73 on the outer peripheral surface 13 side is a part of an ellipse (for example, half of the ellipse).

  The fifth embodiment has the same effects as the first embodiment. In the fifth embodiment, since the concave portion 73 is smoothly curved, there is an advantage that the concave portion 73 is not easily damaged even when a force is applied from the outside.

[4. Experimental example]
Next, a description will be given of an example of an experiment using a calculation or the like.
[4-1. Experimental Example 1]
In Experimental Example 1, the preferred range of the opening area ratio (S / V) was determined by defining the dimensions of each part of the pellicle frame.

(Conventional example)
First, the opening area ratio when a conventional pellicle frame is provided with two ventilation holes as through holes will be described.

  Here, the outer size of the pellicle frame is 149 mm long × 115 mm wide, the inner diameter of the pellicle frame is 145 mm long × 111 mm wide, and the height (thickness) T of the pellicle frame is 1.8 mm or 2 mm. The width of the pellicle frame is 2 mm.

Therefore, the length of the inner side when the pellicle frame is expanded is
(111 + 145) × 2 = 512 mm
The length of the straight part excluding the R part is
(105 + 140) × 2 = 490 mm
The inner volume V of the pellicle frame is
When T = 1.8 mm, 145 × 111 × 1.8 = 28971 mm ³
When T = 2.0 mm, 145 × 111 × 2.0 = 32190 mm ³
Since the diameter of each of the two ventilation holes is φ0.5 mm, the total opening area (total area S) is (0.25) ² × 3.14 × 2 = 0.3925 mm ³
Therefore, the opening area ratio (S / V) is
1.35E-05mm ^-1 when T = 1.8mm
1.2E-05mm ^-1 when T = 2.0mm
(Example of the present disclosure)
Next, an opening area ratio when the pellicle frame of the present disclosure has a concave portion (that is, a cut) having the shape described in the first embodiment will be described. The opening area (that is, the cut area) is the area of the second opening end that opens on the outer peripheral surface side of the concave portion.

As shown in FIG. 3, when the thickness T of the pellicle frame, the depth of cut (depth of the concave portion) t, the cut width (dimension in the Y direction of the concave portion) L1, and the allowance L2, the following formula (1) is obtained. To (3).
The following opening area s is the opening area per one cut, the maximum number of cuts Nmax is the maximum value of the number of cuts, and the maximum opening area Smax is the maximum value of the sum of the opening areas s. (Total opening area S = total area S).

s = t × L1 (1)
Nmax = Inner circumference length of linear portion of pellicle frame / (L1 + L2) (2)
Smax = s × Nmax
= T x L1 x inner circumference length of linear portion of pellicle frame / (L1 + L2) ... (3)
Here, assuming that the minimum value of the margin L2 is 0.2 mm and the maximum value of the cut width L1 is 3 × (Tt) ² , Smax is expressed by the following equation (4).

The reason for setting the maximum value of the cut width L1 to 3 × (T−t) ² is to reduce the amount of deformation (that is, the amount of elastic deformation) when manufacturing the pellicle frame, and to maintain a high flatness of the pellicle frame. That's why.
Smax = s × Nmax = t × 3 (T−t) ² × 490 ÷ (3 (T−t) ² +0.2) (4)
Then, as shown in Tables 1 and 2 below, when T = 1.8 mm and T = 2.0 mm, the maximum opening area Smax [mm ² ] and the opening area are calculated using the above-described equation (4) and the like. The ratio [mm ⁻¹ ] was determined. The opening area ratio is obtained by dividing the maximum opening area Smax by the inner volume V of the pellicle frame.

Here, as shown in Tables 1 and 2, t (cut depth) [mm], Tt (bottom wall thickness d) [mm], cut width Lmax [mm], cut area max / The number of pieces [mm ² ] and the maximum number of cuts Nmax [pieces] were set.

  The cut width Lmax is the cut width L1 at the maximum cut number Nmax, and the cut area max / piece is the opening area per cut at the maximum cut number Nmax.

なお、底部肉厚が０．５ｍｍ未満では、ペリクル枠を製造することはできなかった。

When the bottom thickness was less than 0.5 mm, a pellicle frame could not be manufactured.

Table 1 and Table 2, the opening area ratio is found to be in the range of 0.008 mm ^-1 or 0.02 mm ^-1 or less.
[4-2. Experimental Example 2]
In Experimental Example 2, it was investigated that it is desirable that the cut width L and the bottom thickness d satisfy the relationship of “L / d ² ≦ 3.0”. Here, the description will be made using L instead of L1 as the cut width.

<Experimental example of plate material>
As shown in FIG. 8A, both ends of a test plate (beam member) Q1 having a length of 115 mm × a thickness (T) of 2.5 mm × a width (w) of 2.0 mm are placed on a spacer Q2 having a height of 40 μm. It was then polished with a grindstone (diamond grindstone) Q3 for 40 minutes by reciprocating while rotating.

The distance (span) L between both spacers Q2 was 110 mm.
As a result, as shown in FIG. 8B, the amount of deformation in the thickness direction after polishing (that is, the amount of elastic deformation) was 30 μm.

<Theoretical value of plate material deformation>
Next, a calculation method (theoretical value) of the deformation amount of the plate material based on the above-described experimental results will be described.

  Assuming that the size of the opening portion of the cut is the length L in the longitudinal direction, the bottom thickness (ie, the shortest distance from the bottom surface of the cut to the second surface) d, and the width w of the frame, the amount of deformation during polishing (ie, elasticity) The deformation amount δ is approximated by the following equation (5).

Deformation amount δ ≒ Working load × L × (1 / w) × (1 / d) ^2.・ (5)
Further, the right side of the equation (5) can be rewritten as “(processing pressure × w) × L × (1 / w) × (1 / d) ² ”, so that the following equation (6) is obtained. When the grinding process as shown in FIG. 8A is performed, the grinding speed is controlled to be constant, so that the processing load is the processing pressure × w.

Deformation amount δ 圧 力 (processing pressure x w) x L x (1 / w) x (1 / d) ² ... (6)
Then, assuming that the working pressure is P, equation (7) is obtained from equation (6).
Deformation amount δ ≒ P × L / d ²・ ・ (7)
This indicates that the deformation amount δ is proportional to “P × L / d ² ” and does not depend on the width w.

In the experimental example of the plate material, the warpage (deformation) δ when the span L is 110 mm, the thickness d is 2.5 mm, and the width w is 2.0 mm is 30 μm. , the ^{30 ≒ P × 110 / 2.5 2} . Therefore, P is about 30 / (110 / 2.5 ² ).

Therefore, the following expression (8) is obtained from the expression (7).
Deformation amount δ ≒ P × L / d ² = 30 / (110 / 2.5 ² ) × L / d ² (8)
By rewriting this equation, the following equation (9) is obtained.

Deformation amount δ ≒ 30 × (L / 110) × (2.5 / d) ²・ (9)
Accordingly, by setting the values of L and d in this equation (9) as shown in Table 3 below, the deformation amount δ (μm) can be obtained. In Table 3, the gray range is a range where the deformation amount δ is less than 5 μm.

また、前記表３を「Ｌ／ｄ^２」で規格化した。つまり、表３の各欄に対応したＬ及びｄを用いて「Ｌ／ｄ^２」を求め、その値を表４に対応する欄に記載した。なお、表４においても、灰色の範囲が、変形量δが５μｍ未満に対応する範囲である。

Further, Table 3 was standardized by “L / d ² ”. That is, “L / d ² ” was obtained using L and d corresponding to each column of Table 3, and the value was described in the column corresponding to Table 4. Also in Table 4, the gray range is a range corresponding to a deformation amount δ of less than 5 μm.

この表４及び前記表３から明らかなように、「Ｌ／ｄ^２≦３．０」の範囲であれば、変形量が５μｍ未満であり、凹部を形成して、通気性を向上させたとしても、高い平面度を保つことができ、好ましいことが分かる。

As is clear from Table 4 and Table 3 above, if the range of “L / d ² ≦ 3.0” is satisfied, the deformation amount is less than 5 μm, and a concave portion is formed to improve air permeability. Also, it can be seen that high flatness can be maintained, which is preferable.

[4-3. Experimental Example 3]
In Experimental Example 3, the time required for evacuation and release to the atmosphere was determined by defining the dimensions and the like of each part of the pellicle frame.

A filter that satisfies the ULPA standard is used as the filter.
This ULPA standard is a filter having a particle collection rate of 99.9995% or more for particles having a rated air flow and a particle size of 0.15 μm and having an initial pressure loss of 245 Pa or less. .

  As a test method, it is necessary to determine the rated air volume of the pellicle frame by the following equation (10) based on the provisions of JIS B 9927 clean air filter performance test method (test wind speed = 5.3 [cm / sec]). it can. Here, the entire opening area is simply referred to as the opening area S.

Rated air volume of the pellicle frame = wind speed (53 [mm / sec]) × opening area (S [mm ^2])
= 53S [mm ³ / sec] (10)
The time TA during which the pressure difference of 1 atm (100,000 [Pa]) is evacuated or released to the atmosphere can be obtained from the following equation (11).

TA = (Internal volume of pellicle frame / Rated air volume) x (100000 [Pa] / Allowable pressure difference) ... (11)
Here, assuming that the allowable pressure difference at which the pellicle film does not deform or break is 245 [Pa], the time TA can be obtained from the following equation (12). The calculation is performed on the assumption that the allowable pressure difference is 245 [Pa] for convenience.

TA = {28971 / (53 * S)} * (100000/245) ≒ 180000 / S [sec] ... (12)
Here, as the inner volume of the pellicle frame, a case is used in which the inner diameter of the pellicle frame is 145 mm in length × 111 mm in width, and the height (thickness) T of the pellicle frame is 1.8 mm.

Further, the minimum value of the opening area S of the concave portion can be obtained by the following procedure.
That is, assuming that the evacuation time TA is within 1 hour (3600 [sec]), an opening area of 180,000 / 3600 ≒ 50 [mm ² ] or more is required. That is, the minimum value of the opening area S of the concave portion is about 50 [mm ² ].

The required minimum value of the opening area ratio (S / V) can be obtained from the following equation (13).
Opening area ratio [mm ^-1 ] = 50 [mm ² ] ÷ Internal volume V (28971 [mm ³ ]) = 0.002 [mm ^-1 ] (13)
On the other hand, the maximum value of the opening area S of the concave portion (for example, the maximum value of the total opening area of each concave portion) is 503 mm ² according to the equation (4).

Therefore, the maximum value of the opening area ratio (S / V) is 0.02 mm ⁻¹ by the same calculation as the above equation (13).
Accordingly, the scope of the opening area ratio (S / V), in the conditions described above is considered to 0.002 mm ^-1 or 0.02 mm ^-1 or less.

  When the filter medium described in JP-A-2013-52320 is used as the first filter, the pressure loss is as small as 190 [Pa] or less, and the evacuation time can be reduced. The cover layer is <10 [pa], the pre-collection layer is <80 [Pa], and the main collection layer is <100 [Pa].

When only the main trapping layer <100 [Pa] is used, the pressure loss is further reduced by half, and the evacuation time can be shortened.
[5. Other Embodiments]
It is needless to say that the present disclosure is not limited to the above-described embodiments and the like, and may take various forms as long as it belongs to the technical scope of the present disclosure.

  (1) For example, as a material forming the frame of the pellicle frame, for example, conductive ceramics described in Table 5 below can be employed. Further, for example, non-conductive ceramics described in Table 6 below can be employed.

また、導電性セラミックスの組成及びセラミックス以外の導電性材料の組成としては、下記表７の組成を採用できる。さらに、非導電性セラミックスの組成としては、下記表８の組成を採用できる。

Further, as the composition of the conductive ceramics and the composition of the conductive material other than the ceramics, the compositions shown in Table 7 below can be employed. Further, as the composition of the non-conductive ceramic, the composition shown in Table 8 below can be adopted.

なお、表５のNo.１〜４と表７のNo.８〜１１は同じ材料である。表６のNo.５〜７と表８のNo.１２〜１４は同じ材料である。

Note that Nos. 1 to 4 in Table 5 and Nos. 8 to 11 in Table 7 are the same material. Nos. 5 to 7 in Table 6 and Nos. 12 to 14 in Table 8 are the same material.

  (2) As the ceramic material forming the pellicle frame, various materials such as silicon nitride, zirconia, and composite ceramics of alumina and titanium carbide as disclosed in Japanese Patent Application Laid-Open No. 2016-122091 are used. it can.

  (3) The function of one component in each of the above embodiments may be assigned to a plurality of components, or the function of a plurality of components may be exerted by one component. Further, a part of the configuration of each of the above embodiments may be omitted. Further, at least a part of the configuration of each of the above embodiments may be added to or replaced with the configuration of another embodiment. Note that all aspects included in the technical idea specified by the language described in the claims are embodiments of the present disclosure.

1, 41, 51, 61, 71 pellicle frame 3 pellicle film 5 filter 7 pellicle 11 inner peripheral surface 13 outer peripheral surface 15 first surface 17 second surface 21 side 25, 43, 53 , 63, 73 ... concave portion 26 ... bottom portion 26a ... bottom surface 26b ... R portion

Claims (12)

A pellicle frame having a rectangular shape in plan view and having a first surface and a second surface provided on both sides in a thickness direction, and an inner peripheral surface and an outer peripheral surface connected to the first surface and the second surface. At
An opening in the first surface, comprising a concave portion communicating between the inner peripheral surface side and the outer peripheral surface side,
Pellicle frame. In the longitudinal direction of each side constituting the pellicle frame, the length L of a first opening end of the concave portion that opens to the first surface, and the shortest distance d from the bottom surface of the concave portion to the second surface are: Satisfying the relationship of L / d ² ≦ 3.0,
The pellicle frame according to claim 1. The ratio S / V of the total area Smm ² of the second opening end of the concave portion opening to the outer peripheral surface side and the volume Vmm ^{3 of the} internal space surrounded by the pellicle frame is 0.008 mm ⁻¹ or more and 0.020 mm ^−. Less than or equal to ¹ ,
The pellicle frame according to claim 1. The shape of the concave portion is one of shapes of a rectangle, a trapezoid, a polygon, a part of a circle, and a part of an ellipse when viewed from the inner peripheral surface side and / or the outer peripheral surface side. ,
The pellicle frame according to claim 1. In the longitudinal direction of each side constituting the pellicle frame, the length of the concave portion along the longitudinal direction of the first opening end on the first surface side is the length of the bottom portion of the concave portion along the longitudinal direction. Greater than,
The pellicle frame according to claim 1. The corner at the bottom of the recess has an R chamfered R portion,
The pellicle frame according to claim 1. The pellicle frame is made of a conductive ceramic sintered body,
A pellicle frame according to any one of claims 1 to 6. The pellicle frame is made of a ceramic sintered body having a Young's modulus of 300 GPa or more and a strength of 500 MPa or more.
A pellicle frame according to any one of claims 1 to 7. The pellicle frame is made of a ceramic sintered body having a thermal conductivity of 15 W / mK or more.
A pellicle frame according to any one of claims 1 to 8. The pellicle frame is made of a ceramic sintered body having a coefficient of thermal expansion of 10 ppm / ° C. or less.
A pellicle frame according to any one of claims 1 to 9. A pellicle comprising: the pellicle frame according to any one of claims 1 to 10; and a pellicle film disposed on the first surface side of the pellicle frame,
A first opening end of the concave portion of the pellicle frame on the first surface side is covered with the pellicle film.
Pellicle. A second opening end on the outer peripheral surface side of the concave portion of the pellicle frame is covered with a filter,
A pellicle according to claim 11.

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