JP2018180252A - Pellicle frame and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pellicle frame and a method of producing the frame in which generation of particles can be suppressed.SOLUTION: Because a pellicle frame 1 made of ceramic has a shape that at least a first edge part 23a formed by an inner peripheral surface 7 and an upper surface 11 and a second edge part 23b formed by the inner peripheral surface 7 and a lower surface 13 are R-chamfered having R radius, particle falling at the first and second edge parts 23a, 23b can be suppressed. Therefore, generation of particles by particle falling can be suppressed, so that generation of a defect of a wiring pattern in manufacturing a semiconductor component can be suppressed for example. Particularly, by setting R radius of R chamfer to a value within the range of R0.01 mm to R0.1 mm, particle falling (that is, generation of particles) in the first and second edge parts 23a, 23b can be preferably suppressed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pellicle frame and a method of manufacturing the same.

  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) adhere to the photomask, defects in the wiring pattern occur.

As a countermeasure, that is, to prevent dust, a pellicle in which a transparent thin film (pellicle film) covering the surface of the photomask is stretched is used.
Moreover, in order to arrange this pellicle film away from the photomask by a predetermined distance, a rectangular frame called a pellicle frame is used (see Patent Document 1).

  Since this pellicle frame is required to have high flatness and rigidity in order to suppress deformation of the photomask, a ceramic material is suitable as the material.

JP, 2016-122091, A

  However, while ceramics are high rigidity and high hardness materials, they are brittle materials, so microcracks are easily generated especially at the edges where the surfaces intersect with each other during machining of the pellicle frame, and the cause of particle detachment It has become.

  If particles are generated due to the dropping of particles from the pellicle frame or the like, they cause defects in the wiring pattern as described above, so it is desirable to suppress the generation of particles, but the countermeasure is not always sufficient.

  For example, it is conceivable to perform a C-chamfering process using a diamond grindstone on a ceramic material, but in the C-chamfering process, only the edge angle is increased (for example, changed from 90 ° to 135 °), The edge itself remains unchanged.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a pellicle frame capable of suppressing the generation of particles and a method of manufacturing the same.

(1) A first aspect of the present invention relates to a pellicle frame for stretching a pellicle film, having an inner peripheral surface and an outer peripheral surface, and an upper surface and a lower surface connected to the inner peripheral surface and the outer peripheral surface. is there.
The pellicle frame is made of ceramic, and at least an edge formed by the inner peripheral surface and the upper surface and an edge formed by the inner peripheral surface and the lower surface have a shape having an R radius chamfered.

  In the first aspect, in the pellicle frame made of ceramics, at least the edge formed by the inner peripheral surface and the upper surface and the edge formed by the inner peripheral surface and the lower surface are R-chamfered so that particles fall off at the edge Can be suppressed. Therefore, since the generation of particles due to particle detachment can be suppressed, for example, the remarkable effect of suppressing the generation of defects of the wiring pattern at the time of manufacturing a semiconductor component can be achieved.

(2) In the second aspect of the present invention, the R radius of the R chamfer may be R 0.01 mm to R 0.1 mm.
In the second aspect, by setting the R radius of the R-chamfering in the range of R 0.01 mm to R 0.1 mm, it is possible to preferably suppress particle falling off (thus generation of particles) at the edge portion.

(3) In the third aspect of the present invention, at least one of the upper surface and the lower surface may have a surface roughness of arithmetic average roughness Ra> 0.05 μm and maximum height Ry> 0.5 μm.
The pellicle is attached to the photomask with a pressure sensitive adhesive, but if haze (haze) or foreign matter adheres to the pellicle film due to exposure or the like, it is necessary to replace the pellicle film.

  Then, when peeling the pellicle from the photomask, the adhesive strength of the adhesive needs to be: anti-pellicle frame> anti-photomask so that the adhesive does not remain on the photo mask side. That is, the adhesive needs to be easily peeled off from the photomask and not easily peeled off from the pellicle frame.

  However, since the pellicle frame (especially the upper surface and the lower surface) is usually polished to obtain high flatness, the surface roughness of the upper surface and the lower surface is low (for example, Ra <0.05 μm). The adhesive strength of the agent was not sufficient.

  On the other hand, in the third aspect, bonding of the adhesive is performed by setting at least one of the upper surface and the lower surface to have a surface roughness of arithmetic average roughness Ra> 0.05 μm and maximum height Ry> 0.5 μm. The strength can be increased.

  Thus, when the pellicle is peeled from the photomask, the adhesive can be prevented from remaining on the photomask side, and therefore, the photomask can be prevented from being soiled by the remaining adhesive.

In addition, 0.4 micrometer or less can be employ | adopted as arithmetic mean roughness Ra, and 4.0 micrometer or less can be employ | adopted as maximum height Ry.
(4) In the fourth aspect of the present invention, the Young's modulus may be 150 GPa or more, and the Vickers hardness may be 800 or more.

  Since a pellicle frame having such characteristics uses a sintered body having a high Young's modulus and Vickers hardness, it is possible that the pellicle frame is deformed by the film tension generated when the pellicle film is stretched on the pellicle frame. It can be suppressed.

(5) A fifth aspect of the present invention relates to the method for producing a pellicle frame according to any one of the first to fourth aspects.
In this method of manufacturing a pellicle frame, R-chamfering is performed by polishing the frame body made of ceramic using abrasive grains and a brush.

  When manufacturing a pellicle frame (especially when processing an edge portion), it is conceivable to perform sandblasting regardless of machining. However, in this method, the pellicle frame may be warped due to the compressive stress generated by the impact pressure of the blast abrasive grains, and the flatness may be deteriorated.

  On the other hand, in the fifth aspect of the present invention, the R-chamfering is performed by performing polishing (so-called brush polishing) on the frame made of ceramic using abrasive grains and a brush, so that warpage occurs in the pellicle frame R chamfering can be suitably performed, suppressing that.

(6) In the sixth aspect of the present invention, polishing may be performed using a brush provided with a plurality of filaments containing abrasive grains.
In the sixth aspect, a preferred example in the case of performing polishing using abrasive grains and a brush is shown. The R-chamfering can be suitably performed by using a brush provided with a filament containing abrasive grains. In addition, the surface roughness can be increased and the above-described surface roughness can be suitably adjusted without deteriorating the flatness of the upper surface and the lower surface. In addition, there is an advantage that cleaning and the like are easy at the time of processing.

Hereinafter, the configuration of the present invention will be described.
As a method of obtaining the R radius of the R-chamfering, it is possible to adopt a known method of specifying a circle by performing circle fitting by the method of least squares using coordinates of a plurality of points.

Arithmetic mean roughness Ra and maximum height Ry are in accordance with JIS B 0601-1994.
-As ceramics, either alumina, a zirconia, silicon nitride, sialon, and those composite materials are employable, for example.

  “Consists of ceramic” indicates that the ceramic is 85% by volume or more. For example, a sintered body obtained by sintering an inorganic material such as a sintered body of inorganic particles (ceramic particles) or a composite sintered body of inorganic particles (ceramic particles) and metal particles is included.

  The upper surface of the pellicle frame is one surface connecting the inner peripheral surface and the outer peripheral surface of the frame, and the lower surface is the surface opposite to the upper surface. When the pellicle film is stretched on the upper surface of the pellicle frame, the lower surface is placed on the photomask.

A thickness of 2 mm to 5 mm can be adopted as the thickness of the pellicle frame (dimension between the upper surface and the lower surface).
-As a material of an abrasive grain, a diamond is mentioned, for example. Moreover, as a magnitude | size (size) of an abrasive grain, the thing (for example, # 500) of the range of # 220-# 800 is mentioned.

  -A filament is a threadlike member which constitutes a brush, and nylon, an aramid, etc. are mentioned as the material.

It is a perspective view showing a pellicle frame as an embodiment. It is AA sectional drawing in FIG. FIG. 3A is an enlarged cross-sectional view showing a cross section (a cross section perpendicular to the longitudinal direction) of the frame, and FIG. 3B is an enlarged cross-sectional view showing a portion B (edge portion) in FIG. It is process drawing which shows the manufacturing method of a pellicle frame. It is a magnifying glass photograph in which the edge part of the sample of No. 2 in Experimental example 2 is expanded and shown. It is a microscope picture which expands and shows the edge part of an additional sample. It is a microscope picture which expands and shows the edge part of the sample of a comparative example. It is explanatory drawing which shows the result of the shape measurement at the time of calculating | requiring R radius of the edge part of the upper surface of the sample of No. 7 in Experimental example 3. FIG. It is explanatory drawing which shows the result of shape measurement at the time of calculating | requiring R radius of the edge part of the lower surface of the sample of No. 7 in Experimental example 3. FIG. It is explanatory drawing which shows the result of the shape measurement at the time of calculating | requiring R radius of the edge part of the lower surface of the sample of No. 10 in Experimental example 3. FIG.

Hereinafter, embodiments to which the present invention is applied will be described using the drawings.
[1. Embodiment]
[1-1. overall structure]
First, the entire configuration of the pellicle frame will be described.

  As shown in FIGS. 1 and 2, the pellicle frame 1 is a member made of ceramics (for example, silicon nitride) in which the pellicle film 3 is stretched on one side (upper side of FIG. 2). Note that FIG. 1 shows the pellicle frame 1 itself, and FIG. 2 shows the pellicle 5 in which the pellicle film 3 is stretched on one side of the pellicle frame 1.

  Further, in the following, among all the surfaces of the pellicle frame 1, the inner surface of the pellicle frame 1 is referred to as the inner peripheral surface 7, and the outer surface is referred to as the outer peripheral surface 9. Further, among the surfaces connected to the inner peripheral surface 7 and the outer peripheral surface 9, the side on which the pellicle film 3 is provided is called an upper surface 11 and the opposite surface is called a lower surface 13. In addition, when it is not necessary to distinguish these surfaces, it may only be called a surface.

  As shown in FIG. 1, in the coordinate system of orthogonal X, Y, and Z axes, the pellicle frame 1 is a rectangular frame in a plan view seen from the Z direction, and in the center is a plan view It has a rectangular central through hole 15.

  That is, the pellicle frame 1 is composed of a long frame portion disposed in four directions, upper, lower, left and right, in plan view on the same plane. Specifically, the pellicle frame 1 is configured by an upper frame portion 1c and a lower frame portion 1d disposed in parallel to the X axis, and a left frame portion 1a and a right frame portion 1b disposed in parallel to the Y axis. .

  The external dimensions of the pellicle frame 1 are, for example, about 149 mm in length (Y direction) × about 120 mm in width (X direction) × thickness (Z direction) of about 3 mm. The frame portions 1a to 1d of the pellicle frame 1 are quadrangular prisms, and their vertical and horizontal dimensions (that is, vertical and horizontal dimensions in a cross section perpendicular to the longitudinal direction) are the same (that is, about 3 mm).

  The pellicle frame 1 is provided with four depressions 17 and 19 in the left and right frame portions (left frame portion 1a and right frame portion 1b) in the X direction in plan view. The depressions 17 and 19 are round holes with a bottom, as shown in FIG. 2, and the bottoms are arranged in a conical shape. The recesses 17 and 19 are used for manufacturing the pellicle 5 and positioning for subsequent attachment to a photomask (not shown). At the time of positioning, positioning pins provided on a pellicle manufacturing apparatus or pellicle mounting apparatus (not shown) fit into the four recesses 17 and 19.

  Through holes 21 are provided in the upper frame portion 1c and the lower frame portion 1d of the pellicle frame 1, respectively. After the pellicle 5 is attached to the photomask, the through hole 21 is used to adjust the pressure of the space surrounded by the pellicle 5 and the photomask and the external environment. In addition, the filter which is not shown in figure is provided in the through-hole 21 so that dust may not penetrate | invade from external environment.

  In particular, in the present embodiment, as shown in an enlarged manner in FIG. 3, in each of the frame portions 1 a to 1 d of the pellicle frame 1, a corner portion (first edge portion 23 a) where the inner peripheral surface 7 and the upper surface 11 intersect; A corner portion (second edge portion 23b) where the inner circumferential surface 7 and the lower surface 13 intersect, a corner portion (third edge portion 23c) where the outer circumferential surface 9 and the upper surface 11 intersect, and an outer circumferential surface 9 and the lower surface 13 An R-chamfered portion 25 is formed on the corner (the fourth edge portion 23d) by R-chamfering described later. The R radius of the R chamfered portion 25 is in the range of R 0.01 mm to R 0.1 mm.

  The R-chamfered portion 25 may not be provided on the third edge portion 23 c where the outer peripheral surface 9 and the upper surface 11 intersect and the fourth edge portion 23 d where the outer peripheral surface 9 and the lower surface 13 intersect. The edge portions 23 a to 23 d are collectively referred to as an edge portion 23.

Further, in the present embodiment, the upper surface 11 and the lower surface 13 of the pellicle frame 1 have a surface roughness of arithmetic average roughness Ra> 0.05 μm and maximum height Ry> 0.5 μm.
In addition, only the lower surface 13 of the pellicle frame 1 may be the above-described surface roughness (Ra, Ry), and the upper surface 11 may be a different surface roughness. For example, the surface roughness of the upper surface 11 may be smaller (i.e., smooth) than the surface roughness of the lower surface 13 such as arithmetic mean roughness Ra <0.05 μm and maximum height Ry <0.5 μm. .

  This is because, when the pellicle 5 is attached to the photomask, the surface roughness of the lower surface 13 on the photomask side of the pellicle frame 1 is in the above range, so that the adhesive and pellicle frame when attaching the pellicle 5 to the photomask Adherence with 1 can be secured sufficiently. Therefore, when the pellicle 5 is removed from the photomask, the adhesive can be prevented from remaining on the photomask.

Furthermore, in the present embodiment, the pellicle frame 1 has a Young's modulus of 150 GPa or more and a Vickers hardness of 800 or more.
The flatness of the pellicle frame 1 is 10 μm or less.

[1-2. Outline of manufacturing method of pellicle frame]
Next, an outline of a method of manufacturing the pellicle frame 1 will be described.
(1) As shown in FIG. 4, when manufacturing the pellicle frame 1, powder is manufactured first (process P1).

  Here, powder refers to a substance that is the basis of a sintered body, and as described later, a sintering aid or the like is appropriately added to raw material powders such as silicon nitride, zirconia, or alumina, etc. and wet mixed, and then spray dried. According to the method, it is made into 50 μm to 100 μm granules.

In addition, although the measurement of the particle size of raw material powder was performed by the laser diffraction and the scattering method, you may perform by the dynamic light scattering method or the sedimentation method.
(2) Next, the powder is molded to form an original form of the pellicle frame 1 (step P2).

  In the present embodiment, after firing, it is molded so as to have a length of about 153 mm in length × 124 mm in width × about 7 mm in width (cross-sectional aspect) of the frame portion. Since the outer shape of the pellicle frame 1 is shrunk by about 20 to 30% in the firing step described later, the outer shape of the pellicle frame 1 is previously molded to be larger than the pellicle frame 1 after firing. The pellicle frame 1 can have various sizes in accordance with the size of the exposure mask in the semiconductor exposure apparatus.

(3) Next, after the powder is molded, it is fired at a predetermined temperature (process P3).
The firing temperature is generally 1,500 ° C. or higher, depending on the composition of the powder. By firing, a sintered body having high Young's modulus and hardness can be obtained.

(4) Next, after firing, the outer shape is ground using a machining center or the like (step P4).
The external shape of the pellicle frame 1 shrinks by about 20 to 30% by firing, so dimensional variation of 0.5 to 1.0% is inevitable, and grinding to a desired size by grinding is performed to obtain dimensional accuracy. Do. By grinding, dimensional accuracy and flatness of about 50 μm can be obtained.

(5) Next, plan grinding is performed (process P5).
In the flat grinding process, a disk-shaped diamond grindstone having a width of about 20 mm is rotated at a high speed to flatten the upper surface 11 and the lower surface 13 of the pellicle frame 1 which has been ground. Processing is performed so that the flatness is 10 μm or less, preferably about 5 μm. In addition, arithmetic mean roughness Ra processes about 0.05 micrometer.

(6) Next, polishing of the surface of the pellicle frame 1 and R-chamfering of each edge portion 23 are performed by brush polishing (process P6).
The brushing according to the present embodiment is to polish the surface with a brush provided with a large number of thread-like members (filaments) into which abrasive grains are kneaded. In the present embodiment, the surface is polished by the brush polishing to set the surface roughness of the upper surface 11 and the lower surface 13 in the above-described range, and the edge portion 23 is polished to form the R-chamfered portion 25.

  In detail, the radius of R in the R-chamfered portion 25 is adjusted to the range of R 0.01 mm to R 0.1 mm by this brush polishing. At the same time, the surface roughness of the upper surface 11 and the lower surface 13 of the pellicle frame 1 is adjusted to the range of arithmetic mean roughness Ra> 0.05 μm and maximum height Ry> 0.5 μm.

In addition, as an apparatus (brush grinder: brush processing machine) which performs brush grinding, a commercially available well-known apparatus can be used.
Here, since the size of the radius of curvature depends on the processing time of brushing, the radius of curvature can be adjusted to a desired radius by adjusting the processing time. For example, 2 minutes to 10 minutes can be adopted, preferably 3 minutes to 4 minutes or so.

  Further, since the surface roughness of the pellicle frame 1 depends on the particle size of the abrasive grains, the particle size of the corresponding abrasive grains may be appropriately selected in order to obtain the target surface roughness. In addition, although the correspondence of surface roughness and the particle size of an abrasive grain is disclosed according to a brush polisher, you may confirm by experiment etc.

  In addition, as a material of an abrasive grain, a diamond can be employ | adopted, for example, As a particle size, the range (for example, # 500) of # 220-# 800 can be employ | adopted, for example. Further, as the filament, a diameter of φ1 mm or less (for example, φ0.7 mm) made of a resin such as nylon or aramid can be adopted.

The pellicle frame 1 of the present embodiment can be manufactured by the above steps.
[Example]
Next, a specific example of the method of manufacturing the pellicle frame 1 will be described.

According to the manufacturing process shown in FIG. 4, the pellicle frame 1 using silicon nitride as a main component of a raw material was manufactured at the following processes.
(1) First, silicon nitride powder having an α-type silicon nitride content of 90% by volume or more and an average particle diameter of 0.7 μm, yttrium oxide having an average particle diameter of 1.5 μm as a sintering aid, and an average particle diameter of 1.0 μm These aluminum oxides were wet mixed in a weight ratio of 94: 3: 3, and after adding a molding organic binder, a silicon nitride base powder was produced by a usual spray drying method. This corresponds to the powder production process P1.

(2) Next, the base powder was molded into an outer dimension of about 184 mm long × 149 mm wide × 8.5 mm wide by a die pressing method. This corresponds to the molding step P2.
(3) Further, after removing the binder, the molded body is held at 1850 ° C. for 2 hours in an atmosphere of nitrogen gas at 20 atm, and then the nitrogen gas pressure is increased to 75 atm and held for further 2 hours to obtain dense nitriding. The silicon sintered body (153 mm long × 124 mm wide × 7 mm wide) was fired. This corresponds to the firing step P3.

(4) After that, the outer shape was processed into 149 mm × 120 mm × width 3 mm at a machining center. This corresponds to the external shape grinding process P4.
(5) Further, the top and bottom surfaces subjected to the external shape grinding were subjected to a flat grinding process with a diamond grindstone. This corresponds to the Hiraken process P5.

  (6) Finally, brush polishing is performed using a brush provided with a large number of filaments (filament diameter φ 0.7 mm) including # 500 diamond abrasive grains, and the upper surface 11 and the lower surface 13 are polished, and R chamfering is performed. Did. This corresponds to the brush polishing step P6.

  By the above processing, a pellicle frame 1 containing silicon nitride as a main component was obtained. When the Young's modulus and Vickers hardness of the pellicle frame 1 were measured, the Young's modulus was 320 GPa and the Vickers hardness was 1,500.

A pellicle frame of the same shape may be manufactured using the other ceramic materials such as alumina by the same method as the conventional method except for brush polishing.
[1-3. effect]
(1) In the present embodiment, in the pellicle frame 1 made of ceramics, at least a first edge portion 23a formed by the inner peripheral surface 7 and the upper surface 11, and a second edge portion 23b formed by the inner peripheral surface 7 and the lower surface 13 , R-chamfered, it is possible to suppress the particles falling off at each edge portion 23. Therefore, since the generation of particles due to particle detachment can be suppressed, for example, the remarkable effect of suppressing the generation of defects of the wiring pattern at the time of manufacturing a semiconductor component can be achieved.

  (2) In the present embodiment, by setting the R radius of R chamfering to a range of R 0.01 mm to R 0.1 mm, it is possible to preferably suppress particle falling off (thus generation of particles) at the edge portion 23.

  (3) In the present embodiment, at least one of the upper surface 11 and the lower surface 13 has a surface roughness of arithmetic average roughness Ra> 0.05 μm and maximum height Ry> 0.5 μm. The bonding strength of the agent can be increased.

  As a result, when the pellicle 5 is peeled from the photomask, the adhesive can be prevented from remaining on the photomask side, so that the adhesive can be prevented from being stained by the adhesive.

  (4) In the present embodiment, since the pellicle frame 1 has a Young's modulus of 150 GPa or more and a Vickers hardness of 800 or more, the pellicle frame is generated when the pellicle film 3 is stretched on the pellicle frame 1. It is possible to suppress the deformation of the frame 1.

  (5) In the present embodiment, in the case of manufacturing the pellicle frame 1, the pellicle frame made of ceramics (after planing) is polished using a brush provided with a plurality of filaments containing abrasive grains. Since R-chamfering is performed by processing (i.e., brush grinding), R-chamfering can be suitably performed while suppressing the occurrence of warpage in the pellicle frame 1.

  Moreover, according to this brushing, the surface roughness can be increased and the above-mentioned surface roughness can be suitably adjusted without deteriorating the flatness of the upper surface 11 and the lower surface 13. In addition, there is an advantage that cleaning and the like are easy at the time of processing.

[1-4. Correspondence of wording]
The pellicle frame of the first embodiment, the pellicle frame 1, the pellicle film 3, the inner circumferential surface 7, the outer circumferential surface 9, the upper surface 11, the lower surface 13, the first edge portion 23a and the second edge portion 23b respectively. It corresponds to an example of a pellicle film, an inner peripheral surface, an outer peripheral surface, an upper surface, a lower surface, and an edge portion.

[2. Experimental example]
Next, experimental examples in which the effects and the like of the present invention are confirmed will be described.
Experimental Example 1
A sample of a pellicle frame manufactured by the same method as that of the above example (however, a sample before brush polishing) was subjected to brush polishing using the above-described brush polishing machine under the following test conditions. The results are shown in Table 1 below.

(Test conditions)
・ Diamond abrasive grain size: # 500
· Filament wire diameter: φ 0.7 mm
-Brush tip position: Height from work surface: -0.9 mm
· Polishing rotation direction: The first half of polishing time is normal rotation, the second half is reverse rotation

  In addition, arithmetic mean roughness Ra which shows surface roughness was calculated | required according to the prescription | regulation of JISB0601-1994. (The same may be said of the largest height Ry mentioned later.). The surface roughness (Ra, Ry) was measured using a known surface roughness measurement detector.

 Further, the R-chamfered dimension is the R radius of the edge portion on the central through hole side of the pellicle frame (the same applies to the following). In addition, about this R radius, as shown in Experimental example 3 mentioned later, it calculated | required with the detector for shape measurement.

  As is clear from this Table 1, for the samples of the present invention (samples Nos. 1 to 4) after brush polishing, the arithmetic mean roughness of the surface in the thickness direction of the pellicle frame of the sample (that is, equivalent to the upper surface or lower surface) Ra was greater than 0.05 μm and was a preferred range.

Moreover, R chamfering dimension (namely, R radius of an edge part) was the range of 0.01 mm-0.1 mm, and was a preferable range.
In addition, according to the present experimental example 1, even if the polishing time was increased, the change in the arithmetic mean roughness Ra was not so much seen. In addition, when the polishing time was increased, the R-chamfered dimension increased, but no significant deformation was observed.

<Experimental Example 2>
Further, with respect to each of the samples No. 1 to No. 4 after polishing of Experimental Example 1, when the polished edge part was observed with a scanning electron microscope (200 × magnification), the surface of the edge part was smooth, No defects such as particle detachment were observed.

In addition, the magnifying glass photograph of the edge part of the sample of No. 2 is shown in FIG.
In addition, a similar sample (additional sample) was prepared separately from the above sample, and similarly, when the polished edge was observed with a scanning electron microscope, the surface of the edge was smooth, and particles were dropped, etc. There were no defects found in

The additional sample has a brushing time of 5 minutes and an R radius of 0.03 mm.
A micrograph of the edge of the additional sample is shown in FIG. 6 (a) is a photomicrograph at 500 × magnification, and FIG. 6 (b) is a photomicrograph at 1000 × magnification of the same sample.

<Experimental Example 3>
A similar sample (samples Nos. 5 to 10) was prepared separately from the above-described Experimental Example 1, and brush polishing was performed in the same manner as in Experimental Example 1 (however, a part of the polishing time or the like was changed). The In Experimental Example 3, brush polishing was similarly performed on the upper surface and the lower surface.

Then, the arithmetic average roughness Ra and the maximum height Ry of each sample were measured. In addition, the R-chamfered dimension (that is, the R radius) was measured in the same manner as in Experimental Example 1. The results are shown in Table 2 below.
Moreover, the sample (sample No. 17) of the comparative example besides the range of this invention was produced separately from the sample (sample No. 5-10) of Experimental example 3. FIG. This sample is a sample of a pellicle frame manufactured in the same manner as in Experimental Example 3, but is not subjected to brushing.

 And arithmetic mean roughness Ra and maximum height Ry were measured also about this comparative example (thing which does not carry out brush polish). Also, the R-chamfered dimension (i.e. R radius) was measured. The results are shown in Table 2 below.

 As is apparent from Table 2, in the samples of the present invention (samples Nos. 5 to 10) after brush polishing, the arithmetic average roughness Ra of the upper surface and the lower surface of the pellicle frame of the sample is greater than 0.05 μm and The maximum height Ry was larger than 0.5 μm, which was a preferable range.

In addition, also in the brush-polished edge portion of this sample (samples No. 5 to 10), as in the case of Experimental Example 1, no defect such as falling of particles was observed.
Moreover, R chamfering dimension (namely, R radius of an edge part) was the range of 0.01 mm-0.1 mm for the upper surface and the lower surface, and was a preferable range.

  On the other hand, in the sample (sample No. 17) of the comparative example in which the brush polishing was not performed, the arithmetic average roughness Ra of the surface of the pellicle frame of the sample (the upper and lower surfaces are the same) is smaller than 0.05 μm It was not a range. The maximum height Ry was larger than 0.5 μm.

  Moreover, the edge part of the sample of the comparative example was observed with a microscope. FIG. 7 (a) is a photomicrograph at 500 × magnification of the sample of the comparative example, and FIG. 7 (b) is a photomicrograph at 1000 × magnification of the same sample.

As apparent from FIG. 7, in the sample of the comparative example, the edge portion has no R-chamfered portion, and a defect of particle dropout is observed from the edge portion. This defect can lead to further particle shedding.
(How to find the R radius)
Here, how to obtain the radius R of the R-chamfered portion will be described.

  As well known, a circle can be identified by fitting the circle by the method of least squares using coordinates of a plurality of points. In other words, if the start and end points of the R-chamfer are specified from the profiles of FIGS. 8 to 10 obtained by scanning the stylus of the detector across the edge of the workpiece (ie, the sample) The program can determine the radius of the circle. In the profiles shown in FIGS. 8 to 10, a point transitioning from a straight line to a circle can be designated as the start point of the R shape, and a point returning from the circle to the straight line can be designated as the end point of the R shape.

  In addition, as data of the point group to be used, the range including an edge part can be set suitably. For example, the R radius (and thus the diameter) can be predicted from experiments and the like (specifically, the relationship between the polishing time and the R radius), and a range sufficiently longer (for example, 10 times) than the expected diameter can be set.

Here, the edge part of the upper surface and lower surface of No. 7, and the lower surface of No. 10 is mentioned as an example, and it demonstrates it as a sample which calculates | requires R radius.
The shape of the R-chamfered portion was measured by measuring the shape of the R-chamfered portion with the shape measuring detector attached to a surface roughness meter under the following experimental conditions. In this measurement, the upper surface and the inner peripheral surface were inclined at 45 ° such that the R-chamfered portion protrudes upward at the center (see FIGS. 8 to 10). In FIGS. 8 to 10, the direction perpendicular to the paper surface is the direction in which the edge portion extends.

(Experimental conditions)
・ Detector for shape measurement: SV-C3000 CNC made by Mitutoyo
Measurement length: X direction: left and right direction of each figure (upper surface of No. 7: 1.3354 mm, lower surface of No. 7: 1.2954 mm, lower surface of No. 10: 1.4558 mm)
・ Measurement pitch: 0.0050 mm
・ Measurement speed: 0.50 mm / sec
The measurement results are shown in FIGS.

  As shown in FIG. 8, the radius of the edge part of the upper surface of No. 7 is 0.0373 mm. As shown in FIG. 9, the radius of the edge part of the lower surface of No. 7 is 0.0406 mm. As shown in FIG. 10, the radius of the edge portion of the lower surface of No. 10 is 0.0415 mm.

<Experimental Example 4>
A similar sample (samples Nos. 11 to 16) was prepared separately from the above-mentioned Experimental Example 1, and brush polishing was performed in the same manner as in Experimental Example 1 (however, a part of the polishing time or the like was changed). The The results are shown in Table 3 below.

  In the fourth experimental example, brush polishing was similarly performed on the upper surface and the lower surface.

 As apparent from this Table 3, in the sample of the present invention (sample No. 11 to 16) after brush polishing, the surface roughness Ra of the upper surface and the lower surface of the pellicle frame of the sample is larger than 0.05 μm, and a preferable range Met.

Moreover, R chamfering dimension (namely, R radius of an edge part) was the range of 0.01 mm-0.1 mm for the upper surface and the lower surface, and was a preferable range.
In addition, also in the brush-polished edge portion of this sample (samples No. 11 to 16), no defect such as dropping of particles was observed as in the case of Experimental Example 1.

[3. Other Embodiments]
The present invention is not limited to the above-described embodiment and the like, and it goes without saying that various forms can be adopted within the technical scope of the present invention.

  (1) For example, as a ceramic material for forming a pellicle frame, as disclosed in, for example, JP-A-2016-122091, various materials such as silicon nitride, zirconia, and composite ceramics of alumina and titanium carbide are adopted. it can.

  As disclosed in the same publication (see Embodiments 2 and 3), for example, a pellicle frame using zirconia has a Young's modulus of 210 GPa and a Vickers hardness of 1200, and a pellicle using a composite ceramic of alumina and titanium carbide The frame has a Young's modulus of 420 GPa and a Vickers hardness of 2100.

  (2) As a member used for brush polishing, it is preferable to use a brush provided with a large number of filaments containing abrasive grains, but when focusing on R-chamfering, abrasive grains are supplied separately from the filament. You may grind | polish with a brush.

  (3) Note that the function possessed by one component in the above embodiment may be shared by a plurality of components, or the function possessed by a plurality of components may be exhibited by one component. Further, part of the configuration of the above embodiment may be omitted. In addition, at least a part of the configuration of the above-described embodiment may be added to or replaced with the configuration of the other embodiments. In addition, all the aspects contained in the technical thought specified from the wording as described in a claim are an embodiment of this indication.

DESCRIPTION OF SYMBOLS 1 ... pellicle frame 3 ... pellicle film 5 ... pellicle 7 ... inner peripheral surface 9 ... outer peripheral surface 11 ... upper surface 13 ... lower surface 23 ... edge part 23a ... 1st edge part 23b ... 2nd edge part 25 ... chamfered part

Claims (6)

A pellicle frame for tensioning a pellicle film, comprising: an inner peripheral surface and an outer peripheral surface; and an upper surface and a lower surface connected to the inner peripheral surface and the outer peripheral surface,
The pellicle frame is made of ceramics,
At least an edge formed by the inner peripheral surface and the upper surface, and an edge formed by the inner peripheral surface and the lower surface have an R-chamfered R radius.
Pellicle frame. The R radius of the R chamfer is R 0.01 mm to R 0.1 mm.
The pellicle frame according to claim 1. At least one of the upper surface and the lower surface has a surface roughness of arithmetic average roughness Ra> 0.05 μm and maximum height Ry> 0.5 μm.
The pellicle frame according to claim 1 or 2. Young's modulus is 150 GPa or more, and Vickers hardness is 800 or more.
The pellicle frame according to any one of claims 1 to 3. It is a manufacturing method of the pellicle frame of any one of the said Claims 1-4, Comprising:
The above-mentioned R-chamfering is performed by polishing the frame made of ceramic using abrasive grains and a brush.
Method of manufacturing pellicle frame. Performing the polishing process using a brush provided with a plurality of filaments including the abrasive grains;
The manufacturing method of the pellicle frame of Claim 5.