WO2022145470A1

WO2022145470A1 - Structure, and exposure device and mirror for position measurement using same

Info

Publication number: WO2022145470A1
Application number: PCT/JP2021/048955
Authority: WO
Inventors: 徹彌井上
Original assignee: 京セラ株式会社
Priority date: 2020-12-28
Filing date: 2021-12-28
Publication date: 2022-07-07

Abstract

The present invention comprises a prismatic-shaped or square-tube-shaped elongated body in which the cross section perpendicular to the axial direction is rectangular, and is provided with, on the outer surface thereof, a bonding surface for bonding to a to-be-bonded surface, wherein the bonding surface is provided with a plurality of first grooves that extend in the longitudinal direction of the elongated body, and a plurality of second grooves that intersect the first grooves, and the first grooves are open on both ends thereof and the second grooves are formed such that at least one end thereof is sealed.

Description

Structure, position measurement mirror and exposure equipment using this

The present disclosure relates to, for example, a structure for mounting a reflective film used for position measurement of a substrate stage in an exposure apparatus, a position measurement mirror using the structure, and an exposure apparatus.

Conventionally, a method of measuring the position of a stage on which a substrate is mounted using a laser interferometer and a reflecting mirror has been used in an electron beam exposure apparatus such as an immersion exposure apparatus (Patent Document 1).

In such an exposure apparatus, a stage mechanism as shown in FIG. 8 is used, and the stage mechanism is a substrate stage 101 on which the semiconductor wafer 100 is placed and an X-direction motor 102 that moves the substrate stage 101 in the X direction. The Y-direction motor 103 that moves the board stage 101 in the Y direction, the X-direction position measurement mirror 104 that is fixed to the end of the board stage 101 and extends in the Y direction, and the position measurement mirror 104 are orthogonal to each other. A Y-direction position measurement mirror 105 fixed to the end of the substrate stage 101 and extending in the X direction, and an X-direction position measurement laser interferometer 106 that irradiates the position measurement mirror 104 with laser light. It has a position measurement laser interferometer 107 for irradiating a position measurement mirror 105 with a laser beam in the Y direction.

The position measuring mirror 104 in the X direction has a mirror main body 108 made of a long prismatic or cylindrical body, and a reflective film 109 formed on the surface of the mirror main body 108 on the side to be irradiated with the laser beam. is doing.

The mirror 105 for position measurement in the Y direction has a mirror main body 110 made of a long body having a prismatic or square cylinder shape, and a reflective film 111 formed on the surface of the mirror main body 110 on the side to be irradiated with the laser beam. is doing.

The laser light emitted from the position measurement laser interferometer 106 is reflected by the position measurement mirror 104 and returns to the position measurement laser interferometer 106, interferes with the reference light, and the amount of change in the substrate stage 101 in the X direction changes. It is measured and the position in the X direction from the reference position is calculated.

Similarly, the laser light emitted from the position measurement laser interferometer 107 is reflected by the position measurement mirror 105, returns to the position measurement laser interferometer 107, interferes with the reference light, and is in the Y direction of the substrate stage 101. The amount of change is measured and the position in the Y direction from the reference position is calculated.

Japanese Unexamined Patent Publication No. 2004-177331

The structure of the present disclosure consists of a prismatic or square tubular elongated body having an N-square cross section (N is an integer of 4 or more) perpendicular to the axial direction, and is joined to the outer surface and the bonded surface. The joint surface is provided with a plurality of first grooves extending in the longitudinal direction of the elongated body and a plurality of second grooves intersecting with the first groove, and the first groove is open at both ends. The second groove is sealed at least one end thereof.

The position measurement mirror of the present disclosure has the above structure and a reflective film mounted on the mounted surface of the structure. The exposure apparatus of the present disclosure includes a substrate stage to which a position measuring mirror is joined.

It is a schematic perspective view which looked at the structure which concerns on one Embodiment of this disclosure from the side to which it wears. FIG. 3 is a schematic perspective view of the structure shown in FIG. 1A as viewed from the joint surface side. ~ It is sectional drawing which is perpendicular to the axial direction of the structure shown in FIG. 1A, respectively. It is a front view which shows the joint surface in one Embodiment of this disclosure. It is an enlarged view of the part A of FIG. It is a schematic diagram which enlarged the cross section of the inner peripheral surface surrounding the through hole of the structure shown in FIGS. 1A to 1F. It is sectional drawing perpendicular to the axial direction of the structure in one Embodiment of this disclosure. It is sectional drawing perpendicular to the axial direction of the structure in one Embodiment of this disclosure. It is a schematic perspective view of the linear guide using the structure which concerns on one Embodiment of this disclosure. It is a schematic perspective view which shows an example of the exposure apparatus in this disclosure. It is a schematic schematic diagram which shows an example of a substrate stage.

Hereinafter, the structure according to the embodiment of the present disclosure will be described with reference to the drawings. 1A to 1F show the structure of this embodiment. As shown in FIGS. 1A to 1F, the structure 1 is composed of a long body having a rectangular cross section perpendicular to the axial direction, and has a joint surface 3 for joining to the surface to be joined and a joint surface on the outer surface. Except for 3, the mounted surface 4 on which the functional film is mounted is provided. The joint surface 3 is, for example, a surface on which the structure 1 is mounted on the substrate stage 101 shown in FIG. 8, and the joint surface 3 and the mounted surface 4 are orthogonal to each other. In FIG. 8, the upper surface of the substrate stage 101 facing the joint surface 3 is the surface to be joined.

The flatness of the mounted surface 4 is, for example, 316.4 nm or less. Planarity refers to the magnitude of deviation from a geometrically correct plane of a planar feature. As a method for measuring the flatness, for example, a non-contact method using a laser beam can be adopted. In the non-contact type, the measuring instrument does not come into direct contact with the measuring object and does not damage the measuring object. As a measuring device, for example, a Fizeau type laser interferometer manufactured by ZYGO can be adopted, and if the temperature of the environment to be measured is set to 22 ° C and the temperature fluctuation is controlled to ± 0.05 ° C. good.

The structure 1 having a prismatic shape may have a through hole 8 along the longitudinal direction. The shape of the cross section perpendicular to the longitudinal direction of the through hole 8 is a circular shape or an N-square shape (N is an integer of 4 or more). When the shape of the cross section perpendicular to the longitudinal direction of the through hole 8 is circular, the diameter thereof is preferably, for example, 6 mm or more and 10 mm or less. When the shape of the cross section perpendicular to the longitudinal direction of the through hole 8 is an N-sided shape, the length of the longest diagonal line among the diagonal lines is preferably, for example, 6 mm or more and 10 mm or less. The through hole 8 is provided in order to reduce the weight of the structure 1. When the structure 1 is made lighter, when the structure is mounted on the substrate stage 101 and used, the upper surface of the substrate stage 101 is less likely to bend, so that the flatness of the upper surface is maintained.

The long body in the present disclosure means, for example, a structure having a length of 300 mm or more in the longitudinal direction. The thickness and width of the structure 1 are all preferably 12 mm or more and 20 mm or less, for example. In addition to being prismatic, the structure 1 may have a rectangular tubular shape or the like having a rectangular cross section perpendicular to the axial direction. Further, N-square shapes (N is an integer of 4 or more) including rectangular cross-sections, such as rhombuses, trapezoids (equal leg trapezoids, right angle trapezoids, etc.), pentagons (regular pentagons, pentagons with right angles (eg, Patent No. 1). FIG. 4 (b), etc. disclosed in Japanese Patent Publication No. 4655659), hexagon (regular hexagon, hexagon with steps (for example, fixed mirror 160 in FIG. 1 disclosed in Japanese Patent No. 6380662), etc.), octagonal shape, etc. It may be.

The structure shown in FIG. 5A consists of a long body having a pentagonal cross section perpendicular to the axial direction, and has a joint surface 3 for joining to the surface to be joined and a joint surface 3 on the outer surface, except for the joint surface 3. It is provided with a mounted surface 4 on which a functional film is mounted.

The structure shown in FIG. 5B is a hexagonal long body having a stepped cross section perpendicular to the axial direction, and has a joint surface 3 for joining to the surface to be joined and a joint surface 3 on the outer surface, except for the joint surface 3. It is provided with a mounted surface 4 on which a functional film is mounted.

The material of the structure 1 is, for example, ceramics containing aluminum oxide, silicon carbide or silicon nitride as a main component. In particular, when high dimensional stability, heat resistance, heat resistance deformation, etc. are required, ceramics, glass, etc. having an average linear expansion coefficient within ± 2 × 10 ^-6 / K at 40 ° C to 400 ° C are used. It is possible.

Examples of such ceramics include ceramics containing corgerite, lithium aluminosilicate, potassium zirconium phosphate or mullite as a main component. For ceramics containing cordierite as the main component, Ca is 0.4% by mass or more and 0.6% by mass or less in terms of CaO, Al is _2.3 % by mass or more and 3.5% by mass or less in terms of _Al2O3 , and Mn. And Cr may be contained in an amount of 0.6% by mass or more and 0.7% by mass or less in terms of MnCr ₂ _O4 . This ceramic can have an average coefficient of linear expansion within ± 20 × ^10-9 / K. Ceramics containing lithium aluminosilicate as a main component may contain 20% by mass or less of silicon carbide.

Further, as an example of glass, for example, glass containing titanium silicic acid as a main component can be mentioned. If a member made of ceramics or glass having a small average coefficient of linear expansion is used, the change in shape is small even when exposed to a large temperature change, so that the structure has high reliability.

Here, when the structure 1 is made of ceramics, the average coefficient of linear expansion may be obtained in accordance with JIS R 1618: 2002. When the structure 1 is made of glass, the average coefficient of linear expansion may be obtained in accordance with JIS R 3251: 1995. When the average coefficient of linear expansion of the structure 1 is within ± 1 × 10 ^-6 / K, the measurement may be performed using an optical heterodyne method 1 optical path interferometer.

The main component in ceramics means a component that occupies 60% by mass or more of the total 100% by mass of the components constituting the ceramic of interest. In particular, the main component is preferably a component that accounts for 95% by mass or more of the total 100% by mass of the components constituting the ceramic of interest. The components constituting the ceramics may be obtained by using an X-ray diffractometer (XRD). The content of each component can be determined by determining the content of the elements constituting the component using a fluorescent X-ray analyzer (XRF) or an ICP emission spectroscopic analyzer after identifying the component and converting it into the identified component. good. The same applies to glass.

The shape of the structure 1 may be a prismatic shape in addition to the above-mentioned square tubular shape. As shown in FIG. 1C, the cross section perpendicular to the axial direction may be a square.

As shown in FIG. 1D, the cross section perpendicular to the axial direction may be a square shape in which the

corner portions

11 and 12 on the joint surface 3 side and the mounted surface 4 side are curved surfaces.

As shown in FIG. 1E, the cross section perpendicular to the axial direction may be a square shape in which the corner portion 12'is a curved surface only on the mounted surface 4 side.

As shown in FIG. 1F, in the cross section perpendicular to the axial direction, the corner portions 11'and 12 on the joint surface 3 side and the mounted surface 4 side are curved surfaces, and the radius of curvature thereof is larger than that on the joint surface 3 side. The mounting surface 4 side may have a smaller square shape.

With the shape shown in FIGS. 1D to 1F, the area of the reflective film on the mounted surface 4 can be increased by the

corner portions

11, 11', 12, 12' of the curved surface. In particular, when the shape is as shown in FIG. 1F, the area of the reflective film on the mounted surface 4 can be made larger. When the reflective film is formed on the

corners

11, 11', 12, 12', a part of the open pores in the

corners

11, 11', 12, 12'is sealed by the reflective film, so that the reflective film is opened. Particles that can arise from the pores are reduced.

The cross section of the structure 1 shown in FIGS. 1C and 1D is substantially square, but may be an N-square shape (N is an integer of 4 or more) including a substantially rectangle.

A light source for position measurement, for example, a reflective film (not shown) for reflecting laser light emitted from a laser interferometer for position measurement is mounted on the mounted surface 4 on which the functional film is mounted. Will be done. Examples of the reflective film include a metal film made of aluminum, gold, silver and the like.

The functional film in the present disclosure is a low friction film, a semi-conductive film, etc. other than the reflective film, and is a film to which the required function is imparted to a long body.

When improvement of sliding characteristics is required, a low friction film such as a diamond-like carbon (DLC) film may be mounted on the mounted surface 4.

A member having a structure 1 and a low friction film (for example, a diamond-like carbon (DLC) film) mounted on the mounted surface 4 of the structure 1 is, for example, a guide rail of a linear guide shown in FIG. be.

The linear guide 20 shown in FIG. 6 has a guide rail 23 having a first raceway surface 21 and a V-groove-shaped second raceway surface 22 connected to the first raceway surface 21, and slides movably along the guide rail 23. It comprises a slider 24 having a sliding surface in contact with it, and has a low friction film (not shown) on at least one of the first raceway surface 21 and the second raceway surface 22.

The guide rail 23 is a long prismatic body having a hexagonal cross section perpendicular to the axial direction, and the surface opposite to the first raceway surface 21 is joined to a surface to be joined such as a stage (not shown). It is a joint surface 25 for the purpose.

The slider 24 includes a saddle-shaped base portion 26, a first sliding portion 27 facing the first raceway surface 21, and a second sliding portion 28 facing the second raceway surface 22. Both the first sliding portion 27 and the second sliding portion 28 are attached to the base portion 26.

When the gradual removal of static electricity is required, the semi-conductive film may be mounted on the mounted surface 4. The semi-conductive film in the present disclosure refers to a film having a surface resistance value of ^{105 Ω or more and 10 11} ^Ω or less, for example, aluminum oxide and at least one selected from titanium oxide, zinc oxide and niobium oxide. It is a mixed film with an oxide. When the total of the components of the semi-conductive film is 100% by mass, the oxide such as titanium oxide is preferably contained in a ratio of, for example, 32% by mass or more and 48% by mass or less.

When corrosion resistance to plasma is required, a film containing a rare earth oxide such as yttrium oxide as a main component may be mounted on the mounted surface 4.

The member having the structure 1 and the film containing the rare earth oxide as a main component mounted on the mounted surface 4 of the structure 1 is, for example, a member for a film forming apparatus.

This film forming apparatus member includes, for example, a plurality of sputter sources for depositing a film forming material on a plurality of film-deposited members arranged in a cylindrical processing chamber into which a sputter gas is introduced, and spatters these. It is a prismatic partition wall member that radially divides the inside of the processing chamber for each source. Such a member for a film forming apparatus is described in, for example, Japanese Patent Application Laid-Open No. 2018-3152. The joint surface of the partition wall member is attached to the joint surface of the top plate constituting the processing chamber. The sputter gas is a gas for colliding ions or the like generated by the plasma generated by the application of electric power with the member to be film-formed.

The main component in the film means a component that occupies 60% by mass or more of the total 100% by mass of the components constituting the film. In particular, the main component is preferably a component that occupies 95% by mass or more of the total 100% by mass of the components constituting the film. The components constituting the film may be obtained by using an X-ray diffractometer (XRD). The content of each component can be determined by determining the content of the elements constituting the component using a fluorescent X-ray analyzer (XRF) or an ICP emission spectroscopic analyzer after identifying the component and converting it into the identified component. good.

Hereinafter, the case where the functional film is a reflective film will be described.

As shown in FIG. 1B, the joint surface 3 includes a plurality of first grooves 5 extending in the longitudinal direction of the structure 1 and a plurality of second grooves 6 intersecting with the first groove 5. Specifically, as shown in FIG. 2, the second groove 6 extends in a direction orthogonal to the first groove 5, that is, in a lateral direction orthogonal to the longitudinal direction of the structure 1.

In the present embodiment, three first grooves 5 are formed, but the present invention is not limited to this, and the first groove 5 can be formed in the range of 3 to 6. The second groove 6 can also be formed in the range of 6 to 12.

As shown in FIG. 2, the first groove 5 has both ends 51 and 52 open. This is an adhesive application that applies and fills the first grooves 5b and 5c located on both sides of the joint surface 3 in the lateral direction as shown by an arrow in FIG. 3, which is an enlarged view of the A portion of FIG. This is because when the portion 7 (for convenience, the adhesive coating portion is shown by hatching), it becomes an air discharge path when the adhesive is applied to the first grooves 5b and 5c and when the adhesive is adhered to the surface to be joined. ..

The cutting level at a load length ratio of 25% in the roughness curve of at least one of the first grooves 5b and 5c of the first bottom surface 5x, and the cutting level at a load length ratio of 75% in the roughness curve. The average value of the cutting level difference (Rδc) representing the difference between the above is preferably 1.1 μm or more and 2.3 μm or less.

When the average value of the cutting level difference (Rδc) is 1.1 μm or more, the anchoring effect on the adhesive is high, so that the bonding strength with respect to the object to be bonded such as the substrate stage 101 is improved. When the average value of the cutting level difference (Rδc) is 2.3 μm or less, it becomes difficult for large particles to be detached from the first bottom surface when adhering to the object to be bonded. As a result, the possibility that the particles are mixed with the adhesive is reduced, and the bonding strength is maintained.

The cutting level difference (Rδc) can be measured using a laser microscope (manufactured by KEYENCE Co., Ltd., ultra-deep color 3D shape measuring microscope (VK-X1000 or its successor model)) in accordance with JIS B 0601: 2001. can. The measurement conditions are coaxial epi-illumination for the illumination method, measurement magnification of 120 times, no cutoff value λs, 0.08 mm for the cutoff value λc, no cutoff value λf, and correction of the termination effect at one location. The measurement range may be set to 2792 μm × 2093 μm, and the measurement range may be set from a total of two locations of the target first groove 5b and 5c, the first bottom surface 5x.

Then, for each measurement range, four lines to be measured may be drawn at approximately equal intervals along the longitudinal direction to measure the line roughness. The length of one line to be measured is 2644 μm. The average value of the cutting level difference (Rδc) may be calculated using the cutting level difference (Rδc) obtained from a total of eight lines to be measured.

On the other hand, the second groove 6 is sealed by abutting and communicating with the first grooves 5b and 5c whose both ends are located at both ends in the lateral direction of the structure 1. Therefore, it is possible to prevent the adhesive from squeezing out from the adhesive coating portion 7 through the second groove 6 to the outside, and the bonding efficiency is improved. In FIG. 3, both ends of the second groove 6 are sealed, but the end opposite to the side where the laser beam is reflected by the reflective film, that is, the end on the side where the semiconductor wafer 100 is located is sealed. Just do it. That is, if the end portion on the side where the semiconductor wafer 100 is located is sealed, it is possible to suppress contamination of the semiconductor wafer 100 by at least the outgas generated from the adhesive.

As shown in FIG. 3, the width w1 of the first groove 5a located in the central portion of the structure 1 in the lateral direction is narrower than the width w2 of the other first grooves 5b and 5c located on both sides of the central portion. It should be. As a result, the rigidity of the structure 1 is less likely to be impaired than when the widths of the plurality of first grooves 5 are all the same, and the change in the flatness of the mounted surface for mounting the reflective film is suppressed. Can be done. Further, since the other first grooves 5b and 5c located on both sides are the adhesive application portions 7, a sufficiently wide width is required, whereas the first grooves 5a located in the central portion will be described later. In addition, the groove width is sufficient for discharging air at the time of applying the adhesive to the first grooves 5b and 5c and at the time of joining, and a wide width is not required. By providing the air discharge path in this way, it is possible to prevent the adhesive from squeezing out from the joint surface 3. For example, the width w1 is 1.7 mm or more and 2.3 mm or less, and the width w2 is 2.7 mm or more and 3.3 mm or less.

The plurality of first grooves 5 are mirror surfaces with respect to the center line in the longitudinal direction of the joint surface 3, that is, the line extending in the longitudinal direction at a position having a length of 1/2 of the total length in the lateral direction of the joint surface 3. It should be arranged symmetrically. Further, it is preferable that the plurality of first grooves 5 are arranged at equal intervals in the lateral direction of the structure 1. As a result, it is possible to suppress a partial change in the joint surface 3 in the lateral direction, so that a change in the flatness of the mounting surface is suppressed. Here, the equidistant arrangement of the first grooves 5 means a state in which the intervals of the center lines of the first grooves 5 are equal.

The plurality of second grooves 6 are for the center line in the lateral direction of the joint surface 3, that is, the line extending in the lateral direction at a position of 1/2 of the total length in the longitudinal direction of the joint surface 3. It is better to arrange them mirror-symmetrically. Further, the plurality of second grooves 6 are preferably arranged at equal intervals in the longitudinal direction of the joint surface 3. As a result, the partial change in the longitudinal direction of the joint surface 3 can be suppressed, and the change in the flatness of the mounting surface can be suppressed. Here, the equidistant arrangement of the second grooves 6 means a state in which the intervals of the center lines of the second grooves 6 are equal.

Of the plurality of first grooves 5 and the plurality of second grooves 6, at least the adhesive application portion 7 should have a groove width larger than the groove depth. As a result, the adhesive area is increased while maintaining the rigidity of the structure 1, so that the adhesive strength to the bonded member such as the substrate stage can be increased.

The first bottom surface 5x of the first groove 5 may be a blasted surface or a laser machined surface. Regardless of whether the first bottom surface 5x is a blasted surface or a laser machined surface, the arithmetic mean roughness (Ra) is likely to be larger than that of the ground surface, so that a high anchoring effect can be obtained in the bonding process to the member to be joined. The reliability of the joint is maintained even when vibration is applied.

Similarly, the second bottom surface 6x of the second groove 6 may be a blasted surface or a laser machined surface.

It is preferable that the first bottom surface 5x of the first groove 5b and the side surface of the first groove 5b are connected by a curved surface. When the adhesive is applied by being connected by a curved surface, air bubbles easily escape at the intersection of the first bottom surface 5x and the side surface of the first groove 5b, and the adhesive is filled up to the vicinity of the intersection, so that the bonding strength is increased. Can be high.

For the same reason, it is preferable that the first bottom surface 5x of the first groove 5c and the side surface of the first groove 5c are connected by a curved surface.

The mounted surface 4 should have an arithmetic mean roughness (Ra) of 0.01 μm or more and 0.5 μm or less. When the arithmetic mean roughness (Ra) is 0.01 μm or more, an appropriate anchor effect can be obtained when the reflective film is formed by the vapor deposition method, and the arithmetic mean roughness (Ra) is 0.5 μm or less. Then, since deep scratches are relatively reduced on the mounted surface 4, coarse suspended particles are less likely to adhere to the inside of the scratches. When the arithmetic mean roughness (Ra) is in the above range, the bonding strength of the reflective film is improved and the flatness of the surface of the reflective film is also suppressed.

In order to make the arithmetic mean roughness (Ra) of the mounted surface 4 0.01 μm or more and 0.5 μm or less, the particle size of the abrasive grains should be adjusted when the mounted surface 4 is polished with diamond abrasive grains or the like. Allows the desired arithmetic mean roughness (Ra) to be obtained.

The arithmetic average roughness (Ra) of the mounted surface 4 is obtained in accordance with JIS B0601: 2001. For example, a surface roughness measuring machine (surf coder) SE500 manufactured by Kosaka Laboratory Co., Ltd. is used as a measurement condition. The radius of the stylus may be 5 μm, the measurement length may be 2.5 mm, and the cutoff value may be 0.8 mm.

FIG. 4 is a schematic view of an enlarged cross section of the inner peripheral surface surrounding the through hole 8 of the structure 1 shown in FIG. 1, and is a diagram showing an example of a cross section cut by a plane including the center line of the through hole 8. be. The inner peripheral surface surrounding the through hole 8 of the structure 1 may have crystal particles 9 protruding from the exposed portion 10a of the grain boundary phase 10 existing between the crystal particles. With such a configuration, the grain boundary phase 10 is positioned in a recessed state from the crystal particles 9. Therefore, the contact angle with pure water, ultrapure water, or the like is reduced, and the hydrophilicity (wetting property) is further improved, so that the cleaning efficiency is increased.

In order to obtain an inner peripheral surface having crystal particles 9 protruding from the exposed portion 10a of the grain boundary phase 10 existing between the crystal particles, a molded body made of granules is prepared and machined into the molded body. It can be produced by forming a through hole in the above and then firing this molded body. That is, by forming a so-called baked surface that is not machined after firing, the inner peripheral surface of the through hole 8 protrudes from the exposed portion 10a of the grain boundary phase 10 existing between the crystal particles 9. Will have.

The position measurement mirror includes a base layer (not shown) between the mounted surface 4 and the reflective film (for example,

reflective films

109 and 111 as shown in FIG. 8), and the base layer is chromium, chromium oxide, or the like. It may consist of at least one of yttrium oxide, lanthanum titanate, silicon oxide, titanium oxide, aluminum oxide and magnesium aluminome.

The base layer composed of these components enhances the adhesion between the mounted surface 4 and the reflective film, and can suppress corrosion due to contact of water vapor contained in the pores opened on the mounted surface 4 with the reflective film. can.

The composition formulas of chromium oxide, yttrium oxide, lanthanum titanate, silicon oxide, titanium oxide, aluminum oxide and magnesium aluminate are, for example, CrO, Cr ₂ O ₃ , Y ₂ O ₃ , La TIM ₃ , La ₂ Ti ₃ O. ₈ , SiO ₂ , TiO ₂ , Al ₂ O ₃ and Mg Al ₂ O ₄ . The thickness of the base layer is, for example, preferably 10 to 200 nm, particularly 30 to 80 nm.

The position measuring mirror has a reflective film (not shown) on the surface of the reflective film, and the reflective film is at least one of yttrium oxide, magnesium fluoride, lanthanum titanate, silicon oxide, titanium oxide, and aluminum oxide. It may consist of. The antireflection film can increase the reflectance due to the interference effect of light.

The hyperreflective film composed of these components can increase the reflectance and suppress the corrosion of water vapor contained in the air due to contact with the reflective film. The composition formulas of yttrium oxide, magnesium fluoride, lanthanum titanate, silicon oxide, titanium oxide and aluminum oxide are, for example, Y2O ₃ , MgF, LaTIO ₃ , La ₂ Ti ₃ O ₈ , SiO ₂ , TIO ₂ , and so _on . It is Al ₂ O ₃ .

Further, the hyperrefractive film may include a plurality of laminated bodies composed of a low refractive index layer and a high refractive index layer having a different thickness from the low refractive index layer. With such a configuration, high reflectance can be obtained in a wide wavelength range.

The laminated body is, for example, composed of SiO ₂ or MgF for the low refractive index layer and Nb ₂ O _5, TIO ₂ or HfO ₂ for the high refractive index layer, and the difference in thickness (physical layer thickness) is 1 nm or more and 50 nm or less. The number of laminated bodies is 20 or more (the number of layers is 40 or more). The total thickness of the laminate is, for example, 400 nm or more and 3000 nm or less.

When the surface of the reflective film or the hyperreflecting film is an irradiation surface of light such as laser light, the average value of the root mean square slope (RΔq) in the roughness curve of this surface is preferably 0.1 or less. If the average value of the root mean square slope (RΔq) is 0.1 or less, diffuse reflection is unlikely to occur even if light is incident on the irradiation surface. The accuracy of positioning can be improved. Further, since the unevenness of the irradiation surface is reduced, the possibility that the suspended particles adhere to the irradiation surface is reduced. For the root mean square slope (RΔq), the same method as the method for obtaining the cutting level difference (Rδc) may be used.

The structure of the present disclosure includes a plurality of first grooves 5 in which the joint surface 3 extends in the longitudinal direction of the structure, and a plurality of second grooves 6 intersecting the first groove 5. Both ends are open. As a result, by applying and filling the adhesive in the portions of the

grooves

5 and 6 to be the adhesive coating portion 7, the amount of excess adhesive protruding from between the joint surface 3 and the surface to be joined is reduced, and reflection is achieved. It is possible to suppress changes in the flatness of the mounted surface on which a functional film such as a film is mounted. As a result, the position of the object to be measured such as the substrate stage can be accurately measured.

Further, since the second groove 6 has an end portion located on the side where the light is reflected by the reflective film is sealed, even if the second groove 6 is attached to the side surface of the substrate stage 101 using an adhesive, the reflected light is emitted. Excessive adhesive squeeze out to the side where the receiving reference mirrors (reflecting films 109 and 111) are located is suppressed. Therefore, the irregular scattering of light caused by the protrusion of the adhesive is suppressed. In addition, the reflective film, the base layer, and the hyperreflective film are less likely to be affected by the shrinkage of the adhesive, and the position of the substrate stage can be accurately measured.

The position measurement mirror 1 of the present disclosure has a structure 1 and a reflective film on the mounted surface 4 of the structure 1. That is, the position can be measured by joining to the bonded surface (mounting surface) of the substrate stage 101 or the like shown in FIG. Even if the position measurement mirror 1 is joined to the bonded surface (mounting surface), the flatness of the reflective film mounted on the mounted surface 4 hardly changes, so that accurate position measurement of the substrate stage 101 or the like is possible. Become.

Therefore, the present disclosure is suitably applicable to an exposure apparatus provided with a substrate stage to which a position measuring mirror is joined. FIG. 7 shows an example of the exposure apparatus in the present disclosure. This exposure apparatus includes a substrate stage 101 on which a semiconductor wafer 100 (a substrate to be processed) that may include a photosensitive film (photoresist film) on its surface is placed, and an X-direction motor 102 that moves the substrate stage 101 in the X direction. , The Y-direction motor 103 that moves the substrate stage 101 in the Y direction, the position measurement mirror 115 in the X direction that is fixed to the end of the substrate stage 101 and extends in the Y direction, and the position measurement mirror 115 are orthogonal to each other. A mirror 116 for position measurement in the Y direction fixed to the end of the substrate stage 101 and extending in the X direction, and a projection optical system 112 that irradiates the semiconductor wafer 100 mounted on the substrate stage 101 with exposure light. Have. The projection optical system 112 shown in FIG. 7 is composed of a lens barrel, and when the surface of the semiconductor wafer 100 is set as the in-focus target surface, the focus of the projection optical system 112 is adjusted so as to be in focus with the in-focus target surface. There is. That is, the exposure light L is projected onto the projection region R of the semiconductor wafer 100 by the projection optical system 112. By exposing the semiconductor wafer 100 with the exposure light L in this way, an image of a pattern corresponding to the film pattern to be formed is projected onto a resist film (not shown) on the semiconductor wafer 100. Then, the exposed resist film is developed.

Further, the position measurement mirror of the present disclosure can be applied not only to an exposure apparatus but also to an application requiring accurate position measurement, for example, an optical component mounted on a space flying object such as a satellite. Further, the structure of the present disclosure can be applied not only to a mirror for position measurement and a guide rail, but also to a member for a long liquid crystal panel manufacturing device and a member for a semiconductor manufacturing device.

Next, an example of the manufacturing method of the structure of the present disclosure will be described. A case where the structure is made of ceramics containing cordierite as a main component will be described.

First, synthetic cordierite powder, aluminum oxide powder, and calcium carbonate powder, which are crushed by calcining a mixed powder prepared so that each powder of magnesium carbonate, aluminum oxide, and silicon oxide has a predetermined ratio, are used. Weigh at a predetermined ratio and use as the primary raw material.

Here, for example, the content of aluminum oxide powder contained in the total 100% by mass of the primary raw material is 3% by mass or more, and the content of calcium carbonate powder in terms of CaO is 0.4% by mass or more and 0.6% by mass. Below, the synthetic corderite powder may be 95% by mass or more.

With such a ratio, the absolute value of the average linear expansion rate from 40 ° C to 400 ° C is 0.03 ppm / ° C or less, the specific rigidity is 57 GPa · cm ³ / g or more, and the four-point bending strength is high. Ceramics of 250 MPa or more can be used.

In order to improve the mechanical strength and chemical resistance of the ceramics, zirconium oxide powder may be contained in an amount of 3% by mass or less in a total of 100% by mass of the primary raw materials. After wet mixing this primary raw material, a binder is added to obtain a slurry.

Next, the slurry is sprayed and dried by the spray granulation method (spray drying method) to obtain granules. Granules are filled in a molding die and molded by a hydrostatic pressure press molding (rubber press) method or a powder press molding method to obtain a prismatic molded body. If necessary, a prismatic structure 1 can be obtained by forming a through hole 8 by cutting and then firing at a maximum temperature of 1400 ° C. or higher and 1450 ° C. or lower in the atmospheric atmosphere. Further, a square tubular structure 1 can be obtained by cutting from a prismatic molded body.

Further, by hot isotropic pressure pressing at a pressure of 100 to 200 MPa and a temperature of 1000 to 1350 ° C. after firing, the density can be further refined.

Then, of the fired surface to be the joint surface after polishing, the unprocessed portion may be covered with a mask, and in that state, the first groove 5 and the second groove 6 may be formed by blasting or laser processing.

After forming the first groove 5 and the second groove 6, the mask is removed, and at least after polishing, the first fired surface to be the mounted surface 4 and the second fired surface to be the joint surface 3 are polished to obtain the present disclosure. Structure 1 can be obtained.

Regarding the details of polishing, for example, first, using abrasive grains of aluminum oxide having an average particle size of 1 μm, polishing is performed on a polyurethane pad for 2 to 10 hours. Next, a slope and a joint surface can be obtained by polishing on a polyurethane pad for about 2 to 10 hours using cerium oxide abrasive grains having an average particle size of 1 μm.

For the purpose of reducing residual stress generated by firing, at least one of the third firing surface connecting the first firing surface and the second firing surface and the end faces located at both ends in the longitudinal direction of the structure is polished. May be good.

Then, the position measurement mirror provided with the underlayer, the reflective film, the antireflection film and the like can be formed by, for example, a vapor deposition method such as vacuum deposition or ion-assisted vapor deposition, sputtering or ion plating.

1 Structure 3 Joint surface 4 Mounted surface 5, 5a, 5b, 5c 1st groove 5x 1st bottom surface 6 2nd groove 6x 2nd bottom surface 7 Adhesive coating part 8 Through hole 9 Crystal particle 10 Grain boundary phase 10a

Exposed part

11, 11', 12, 12'Square 20 Linear guide 21 First track surface 22 Second track surface 23 Guide rail 24 Slider 25 Joint surface 26 Base 27 First sliding part 28 Second sliding part 100 Semiconductor wafer 101 Substrate Stage 102 X-direction motor 103 Y-

direction motor

104, 105

Position measurement mirror

106, 107 Position

measurement laser interferometer

108, 110

Mirror body

109, 111 Reflective film

Claims

It consists of a prismatic or square tubular elongated body whose cross section perpendicular to the axial direction is N-square (N is an integer of 4 or more), and has a joint surface on the outer surface for joining to the surface to be joined. The joint surface includes a plurality of first grooves extending in the longitudinal direction of the elongated body and a plurality of second grooves intersecting the first groove, and the first groove is open at both ends. The second groove is a structure in which at least one end thereof is sealed.
The structure according to claim 1, wherein at least one of the outer surfaces is a mounted surface to which a functional membrane is mounted, except for the joint surface.
The structure according to claim 1 or 2, wherein the long body is made of ceramics or glass having an average coefficient of linear expansion of ± 2 × 10-6 / K at 40 ° C to 400 ° C.
In the joint surface, the width of the first groove located in the central portion in the lateral direction intersecting the longitudinal direction of the elongated body is larger than the width of the other first grooves located on both sides of the central portion. The narrow structure according to any one of claims 1 to 3.
The structure according to any one of claims 1 to 4, wherein the plurality of first grooves are arranged mirror-symmetrically with respect to the center line in the longitudinal direction of the joint surface.
The structure according to any one of claims 1 to 5, wherein the plurality of first grooves are arranged at equal intervals in the lateral direction of the joint surface.
The structure according to any one of claims 1 to 6, wherein the plurality of second grooves are arranged mirror-symmetrically with respect to the center line in the lateral direction of the joint surface.
The structure according to any one of claims 1 to 7, wherein the plurality of second grooves are arranged at equal intervals in the longitudinal direction of the joint surface.
The structure according to any one of claims 1 to 8, wherein at least the adhesive-applied portion has a groove width larger than the groove depth among the plurality of the first grooves and the plurality of the second grooves.
The structure according to any one of claims 1 to 9, wherein the first bottom surface of the plurality of first grooves is a blasted surface or a laser machined surface.
The structure according to any one of claims 1 to 10, wherein the second bottom surface of the plurality of second grooves is a blasted surface or a laser machined surface.
The structure according to any one of claims 1 to 11, wherein the arithmetic mean roughness (Ra) of the mounted surface is 0.1 μm or more and 0.5 μm or less.
The elongated body has a through hole along the longitudinal direction, and the inner peripheral surface surrounding the through hole has crystal particles protruding from the exposed portion of the grain boundary phase existing between the crystal particles. The structure according to any one of claims 1 to 12.
A position measurement mirror having the structure according to any one of claims 1 to 13 and a reflective film mounted on the mounted surface of the structure.
An underlayer is provided between the mounting surface and the reflective film, and the underlayer is at least one of chromium, chromium oxide, yttrium oxide, lanthanum titanate, silicon oxide, titanium oxide, aluminum oxide, and magnesium aluminome. The position measuring mirror according to claim 14.
15. The 15th aspect of the present invention, wherein a hyperreflective film is provided on the surface of the reflective film, and the hyperreflective film is composed of at least one of yttrium oxide, magnesium fluoride, lanthanum titanate, silicon oxide, titanium oxide and aluminum oxide. Mirror for position measurement.
A claim is provided that a hyperrefractive film is provided on the surface of the reflective film, and the antireflection film includes a plurality of laminates composed of a low refractive index layer and a high refractive index layer having a different thickness from the low refractive index layer. Item 5. The position measuring mirror according to Item 15.
An exposure apparatus including a substrate stage to which a position measurement mirror according to any one of claims 14 to 17 is joined.