JP2004078209A - Holding device, exposing device and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a holding device which brings about desired optical performance by reducing the deformation of an optical member to be deterioration of imaging performance and aberration of positional deviation and to provide an exposing device and a device manufacturing method. <P>SOLUTION: This holding device 100 holds an optical member 110 having three first grooves 116, has a first support member 120 for supporting the optical member through the first grooves 116, three second grooves 132 corresponding to the first grooves 116, and a second support member (fixed part) 130 for supporting the first support member 120 through the second grooves 132. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention generally relates to a precision instrument on which an optical member is mounted, in particular, to a projection optical system such as an exposure apparatus, and more particularly, to a semiconductor device, an imaging device (such as a CCD) or a thin film magnetic head. In an exposure apparatus used in a lithography process, when an image of an original (for example, a mask or a reticle (the terms are used interchangeably in the present application)) is projected and exposed on an object to be processed, it is more accurate. TECHNICAL FIELD The present invention relates to a holding device for an optical member for obtaining a proper imaging relationship.

2. Description of the Related Art When manufacturing a device using a photolithography (printing) technique, a reduction projection exposure apparatus that transfers a circuit pattern by projecting a circuit pattern drawn on a mask onto a wafer or the like by a projection optical system has been conventionally used. . The projection optical system forms an image by causing the diffracted light from the circuit pattern to interfere with the wafer.

In order to meet the recent demand for smaller and thinner electronic devices, it is necessary to highly integrate devices mounted on the electronic devices, and finer circuit patterns to be transferred, that is, higher resolution Are increasingly required. In order to obtain a high resolution, it is effective to shorten the wavelength of the exposure light and increase the numerical aperture (NA) of the projection optical system, and at the same time, the aberration of the projection optical system must be extremely small. .

(4) When deformation occurs in an optical element such as a lens or a mirror that constitutes a projection optical system, an optical path is refracted before and after the deformation, and a ray to be imaged at one point does not converge at one point, causing an aberration. The aberration causes a displacement and a short circuit of the circuit pattern on the wafer. On the other hand, if the pattern size is increased in order to prevent a short circuit, it is against the demand for miniaturization.

Therefore, in order to realize a projection optical system with small aberration, the shape and the position of the optical element constituting the projection optical system with respect to the optical axis are held in the projection optical system without changing, and the original It is necessary to maximize optical performance. In particular, with the recent increase in the NA of the projection optical system, the diameter of the projection lens has been increased, so that the volume of the lens has also been increased, and deformation due to its own weight has been likely to occur. An exposure apparatus using extreme ultraviolet (EUV) light, which has been actively studied recently, has a short wavelength EUV light (wavelength of about 10 nm to 15 nm) which is one of its features. The projection optical system must be composed of a small number of reflecting elements (that is, mirrors), and the shape of the mirror and the positional accuracy with respect to the optical axis are extremely severe.

(4) Since the EUV exposure apparatus is used for exposure of a circuit pattern of 0.1 μm or less, the line width accuracy is very strict, and the mirror shape is allowed to have a deformation of about 0.1 nm or less. Therefore, it is necessary to accurately reproduce the mirror processing shape when incorporating the mirror into an EUV exposure apparatus.

However, the base material of the mirror is very soft, and the mirror is deformed by about 0.1 nm only by the force (holding force) applied by the holding member holding the mirror. In addition, the displacement of the mirror is caused by thermal expansion, vibration, and deformation of the holding member. Furthermore, the mirror does not reflect all of the exposure light, but absorbs more than 30% of the exposure light, so that the absorbed exposure light is split into heat and thermally expands the mirror. Changes the position with respect to. Therefore, the mirror cannot be held in the projection optical system without changing its shape and position with respect to the optical axis, and the desired optical performance cannot be exhibited.

Accordingly, it is an exemplary object of the present invention to provide a holding apparatus, an exposure apparatus, and a device manufacturing method that provide desired optical performance by reducing aberration due to deformation and displacement of an optical member that deteriorates imaging performance. And

In order to achieve the above object, a holding device according to one aspect of the present invention is a holding device that holds an optical member having three first grooves, and supports the optical member via the first grooves. A first support member, and a second support member (fixing member) having three second grooves corresponding to the first grooves and supporting the first support member via the second grooves. It is characterized by having.

保持 A holding device as another aspect of the present invention is characterized in that the first groove is a linear groove along the radial direction.

保持 A holding device as yet another aspect of the present invention is characterized in that three first grooves or their extensions intersect at substantially one point.

保持 A holding device as yet another aspect of the present invention is characterized in that three second grooves or their extensions intersect at substantially one point.

保持 A holding device as still another aspect of the present invention is characterized in that at least one of the three first grooves or the three second grooves has a spiral shape.

According to still another aspect of the present invention, there is provided a holding device in which one of the three first grooves or an extension thereof intersects with the other first groove or an extension thereof, and It is characterized in that a point where one groove or its extension line intersects with the remaining first groove or its extension line is different.

According to still another aspect of the present invention, there is provided a holding device in which one of the three second grooves or an extension thereof intersects another second groove or an extension thereof, and The second groove or its extension is different from the intersection with the remaining second groove or its extension.

保持 The holding device according to claim 3, wherein the substantially one point is a center of the optical member.

保持 A holding device as still another aspect of the present invention is characterized in that the above-mentioned approximately one point is a point other than the center of the optical member.

保持 A holding device as yet another aspect of the present invention is characterized in that three second grooves or their extensions intersect at substantially one point.

保持 A holding device according to yet another aspect of the present invention is characterized in that three first grooves form 120 degrees with each other and three second grooves form 120 degrees with each other.

保持 A holding device as still another aspect of the present invention is characterized in that the first groove and the second groove have a V-shaped cross section.

保持 A holding device as still another aspect of the present invention is characterized in that the V-shaped cross section has an angle of about 90 °.

保持 A holding device as still another aspect of the present invention is characterized in that the first support member has a spherical shape.

保持 A holding device as still another aspect of the present invention is characterized in that the first support member is rollable along the first groove and the second groove.

In a holding device according to still another aspect of the present invention, the optical member and the first support member are in contact with each other at a position 60% to 70% of the radius of the optical member from the center of the optical member. .

A holding device as still another aspect of the present invention is a holding device for holding an optical member having three spherical convex portions on an outer periphery, and includes a spherical convex portion in a direction along a radial direction of the optical member. It has a groove having a substantially V-shaped cross section for mounting, and a holding member for holding the optical member through the groove.

保持 A holding device as still another aspect of the present invention is characterized in that the holding member is movable in the radial direction of the optical member.

保持 A holding device as still another aspect of the present invention is characterized in that three spherical projections are arranged at a pitch of 120 degrees with respect to the center of the optical member.

保持 A holding device as still another aspect of the present invention is characterized by further having a drive mechanism for driving each of two support planes forming a groove in a direction perpendicular to the support plane.

A holding device as still another aspect of the present invention is characterized in that the projection has a hole having a V-shaped cross section, and further has pressure applying means for applying pressure to the spherical surface through the hole. .

A holding device as still another aspect of the present invention is a holding device for holding an optical member having three V-shaped protrusions on the outer periphery, and two holding members that are in contact with each other so as to sandwich the V-shaped protrusion. It has a spherical portion, and has a holding member for holding the optical member via the spherical portion.

保持 A holding device as still another aspect of the present invention is characterized in that the holding member is movable in a direction along a radial direction of the optical member.

保持 A holding device as still another aspect of the present invention is characterized in that three V-shaped protrusions are arranged at a pitch of 120 degrees with respect to the center of the optical member.

保持 A holding device as still another aspect of the present invention is characterized in that the optical member is a mirror.

An exposure apparatus as still another aspect of the present invention includes the holding device according to claim 2, and exposes a pattern formed on a mask or a reticle to an object to be processed through an optical member held by the holding device. It is characterized by having an optical system to perform.

An exposure apparatus as still another aspect of the present invention includes the holding device according to claim 3, and exposes a pattern formed on a mask or a reticle to an object to be processed through an optical member held by the holding device. It is characterized by having an optical system to perform.

A holding device as still another aspect of the present invention includes the holding device according to claim 17, and exposes a pattern formed on a mask or a reticle to an object to be processed through an optical member held by the holding device. It is characterized by having an optical system to perform.

An exposure apparatus as still another aspect of the present invention includes the holding device according to claim 22, and exposes a pattern formed on a mask or a reticle to an object to be processed through an optical member held by the holding device. It is characterized by having an optical system to perform.

A device manufacturing method according to still another aspect of the present invention includes a step of projecting and exposing an object to be processed by using the exposure apparatus according to claim 26, and a step of performing a predetermined process on the object to be projected and exposed. It is characterized by having.

A device manufacturing method according to still another aspect of the present invention includes a step of projecting and exposing an object to be processed using the exposure apparatus according to claim 27, and a step of performing a predetermined process on the object to be projected and exposed. It is characterized by having.

A device manufacturing method as still another aspect of the present invention includes a step of projecting and exposing an object to be processed by using the exposure apparatus according to claim 28, and a step of performing a predetermined process on the object to be projected and exposed. It is characterized by having.

A device manufacturing method according to still another aspect of the present invention includes a step of projecting and exposing an object to be processed using the exposure apparatus according to claim 29, and a step of performing a predetermined process on the object to be projected and exposed. It is characterized by having. The claims of the device manufacturing method having the same operation as that of the above-described exposure apparatus extend to the device itself as an intermediate and final product. Such devices include semiconductor chips such as LSI and VLSI, CCDs, LCDs, magnetic sensors, thin-film magnetic heads, and the like.

Further objects and other features of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

According to the holding device of the present invention, desired optical performance can be achieved by reducing aberrations due to deformation and displacement of the optical member, which deteriorates imaging performance.

Hereinafter, exemplary holding devices and exposure devices of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to these embodiments, and each component may be replaced as long as the object of the present invention is achieved. For example, in the present embodiment, the holding device 100 is exemplarily applied to the projection optical system 530 of the exposure device 500, but may be applied to the illumination optical system 514 of the exposure device 500 or any other known optical system. . Here, FIG. 1 is a schematic configuration diagram showing a holding device 100 according to one aspect of the present invention. FIG. 1A is a perspective view of the holding device 100, and FIG. FIG. 2 is a cross-sectional view of the holding device 100 shown in FIG.

The holding device 100 includes a support member 120 (a first support member) and a fixing member (a second support member) 130, as is often shown in FIG. The holding device 100 is applied to the projection optical system 530, and holds the optical member 110 via the support member 120 and the fixing member 130.

The optical member 110 is mounted on a support member 120 described below via the first groove 116, and forms an image of light using reflection, refraction, diffraction, and the like. In the present embodiment, the optical member 110 is illustratively configured as a mirror. For example, a diffractive optical element such as a mirror, a lens, a parallel plate glass, a prism and a Fresnel zone plate, a kinoform, binary optics, and a hologram is used. including. As shown in FIG. 2, the optical member 110 has first grooves 116 having a V-shaped cross section at three places on a bottom surface 114 (that is, on the support member 120 side) opposite to the reflection surface 112 that reflects light. Here, FIG. 2 is a schematic perspective view of the optical member 110 shown in FIG.

The first groove 116 is arranged in a radial direction opened at a 120 ° pitch from the center O of the bottom surface 114 of the optical member 110. The first groove 116 is placed on a support member 120 described later, and the optical member 110 is held via the first groove 116. As described above, since the first grooves 116 are distributed at substantially equal intervals along the circumferential direction of the optical member 110, the optical member 110 is stabilized on the support member 120. The first groove 116 is provided between the support member 120 and the optical member at a position 60% to 70% of the radius of the optical member 110 from the center O in the radial direction so that the bending due to the own weight deformation of the optical member 110 is minimized. It is preferable to arrange the first groove 116 so as to be in contact therewith. Therefore, it is preferable to form the first groove 116 at a position 50 to 80% of the radius from the center O in the radial direction of the optical member 110, or at a position within this range. Of course, the first groove 116 itself may be formed at a position of 60 to 70% as shown in FIG.

The support member 120 is a member having a spherical shape, and is in contact with the first groove 116. The support member 120 supports the optical member 110 via the first groove 116. The support member 120 is made of, for example, a material having a linear expansion coefficient substantially equal to the linear expansion coefficient of the optical member 110. With such a configuration, when the temperature environment changes, the relative displacement between the optical member 110 and the support member 120 caused by the difference in the coefficient of linear expansion causes the support member 120 to separate from the first groove 116 or cause the first groove 116 to move. It is possible to prevent the optical member 110 from being deformed by applying an external force via the optical member 110.

The fixing member 130 is disposed on the side facing the optical member 110 with respect to the support member 120. The fixing member 130 has second grooves 132 having a V-shaped cross section at three places on the surface on the optical member 110 side, and fixes the support member 120 via the second grooves 132.

The second groove 132 is arranged in a radial direction opened at a pitch of 120 ° from the center O. In other words, the second groove 132 is arranged at a position facing the first groove 116 arranged on the bottom surface 114 of the optical member 110. The second groove 132 mounts the support member 120 so as to be movable in the radial direction (that is, with a degree of freedom in the radial direction). That is, the second groove 132 defines the circumferential movement of the support member 120 and is formed such that the true spherical support member 120 rolls in the radial direction. Accordingly, the second groove 132 allows the optical member 110 or the fixed member 130 to expand in the radial direction even when thermal expansion occurs, when the temperature environment fluctuates. Therefore, the center O of the optical member 110 is aligned with the optical axis. On the other hand, it is possible to prevent displacement.

The holding device 100 places the support member 140 in the second groove 132 of the fixing member 130, and further places the optical member 110 on the support member 140 so that the first groove 116 contacts the optical member 110. Hold 110. As shown in FIG. 3, the first groove 116 of the optical member 110 and the second groove 132 of the fixing member 130 have an angle θ of a V-shaped cross section of approximately 90 °. The groove 116) and the support member 120 contact at two points A1 and A2, and the support member 120 and the (second groove 132 of) the fixing member 130 also contact at two points B1 and B2. Further, the support member 120 is designed to contact the first groove 116 and the second groove 132 at two points. Therefore, as a whole of the holding device 100, the optical member 110 is supported by the support member 120 at six points, and the support member 120 is supported by the fixing member 130 at six points, thus providing kinematic support. The position of the optical member 110 is uniquely determined because the support member 120 is fixed to the fixing member 130 by the weight of the optical member 110. Therefore, the holding device 100 can minimize the own weight deformation of the optical member by arranging the first groove 116 at a position 60% to 70% away from the center O of the optical member 110, and The optical member 110 is kinematically supported by the support member 120 that can move in the radial direction along the second groove 132, thereby reducing aberrations due to deformation and displacement of the optical member 110, which deteriorates imaging performance. Thereby, desired optical performance can be achieved. In the case where the optical member 110 is a transmissive member, a hole may be provided in the fixing member 130 in accordance with the transmission region of the optical member 110 so as not to block light. Member 130 may be used. Here, FIG. 3 is a schematic sectional view showing the first groove 116 of the optical member 110, the support member 120, and the second groove 132 of the fixing member 130 in a state where the holding device 100 holds the optical member 110.

Here, the first groove 116 and the second groove 132 are formed at a pitch of 120 degrees around the center O of the optical member, but this is not a limitation, and the first groove 116 and the second groove 132 may be formed. An angle other than 120 degrees may be used as long as the two grooves 132 correspond to each other. However, the three angles between each of the three grooves are preferably configured such that two of the three angles are equal, and the two equal angles are greater than 120 degrees; In particular, it is preferable that the angle is set to 150 degrees or more.

Furthermore, the first groove does not necessarily need to be arranged to extend in the radial direction, and may be arranged as shown in FIG. 15, for example. FIG. 15 is a plan view of the holding device 100 in which the first groove 116A is formed. The three first grooves 116A are formed by a point where one of the first grooves 116a or an extension thereof intersects with the other first groove 116b or an extension thereof, and one of the first grooves 116a or the extension thereof. The extension is formed so as to be different from the point where the extension intersects with the remaining first groove 116c or the extension thereof.

In addition, the first grooves do not necessarily have to be arranged in a straight line. For example, as shown in FIG. 16A, one spiral first groove 116B is formed in the holding device 100. May be. Furthermore, as shown in FIG. 16C, for example, three spiral first grooves 116D are formed so as to intersect at the center of the holding device 100 and spread while drawing spirals at equal intervals. Of course it is good.

The same can be said for not only the first groove but also the second groove. That is, the second groove 132 does not necessarily need to extend along the radial direction, and need not be linear.

Here, each of the first groove and the second groove has three grooves along the radial direction of the optical member, and each of the three grooves corresponds to a corresponding position (the same position with respect to the center of the optical member). The optical member can be fixed by the holding device if the angled state or the angle formed by each of the three grooves is equal to each other.

In addition, three first grooves intersect or three first grooves intersect on an extension line, and three second grooves also intersect or three second grooves intersect on an extension line. With this configuration, the optical member can be similarly fixed by the holding device. Here, it is preferable that approximately one point where the three grooves intersect (the width is widened by the width of the groove, and may be finer) is the center of the optical member. However, it may be other than the center.

Further, it is preferable that the support member 120 (first support member) has a true sphere shape, but it is only necessary that only a region in contact with the first groove or the second groove has a sphere shape. The shape need not be a true sphere.

Next, another holding device 200 will be described with reference to FIGS. FIG. 4 is a schematic configuration diagram showing another holding device 200 as one aspect of the present invention. The holding device 200 is applied to the projection optical system 530, and holds the optical member 210 via the holding member 220 as shown in FIG.

The optical member 210 is mounted on a holding member 220 described later via a convex portion, and forms an image of light using reflection, refraction, diffraction, and the like. The optical member 210 includes, for example, a diffractive optical element such as a mirror, a lens, a parallel plate glass, a prism and a Fresnel zone plate, a kinoform, binary optics, and a hologram. As shown in FIG. 5, the optical member 110 has three spherical convex portions 212 on the outer periphery. Here, FIG. 5 is a schematic perspective view of the optical member 210 shown in FIG.

The three spherical projections 212 are arranged at a pitch of 120 °. As described above, since the optical members 210 are distributed at substantially equal intervals along the circumferential direction of the optical member 210, the optical member 210 is stabilized on the holding member 220. In the present embodiment, since the convex portion 212 is formed integrally with the optical member 210, when the convex portion 212 is joined to the optical member 210, a force is applied to the optical member 210, and the surface shape changes. Nothing. However, if the surface shape of the optical member 210 does not change by joining the convex portion 212 to the optical member 210, or if the change in the surface shape is within an allowable range, the optical member 210 and the convex portion 212 are separated. You may comprise.

The holding member 220 has a groove 222 having a V-shaped cross section for mounting three spherical protrusions 212 provided on the outer periphery of the optical member 210 in a direction along the radial direction of the optical member 210, The optical member 210 is held through the groove 222. The holding member 220 is arranged in accordance with the protrusion 212 provided on the outer periphery of the optical member 210. The holding member 220 is freely movable only in the radial direction of the optical member 210, and is formed of an elastic member having sufficient rigidity in the radial direction and other directions, for example, a parallel leaf spring. When the holding member 220 places the spherical convex portion 212 of the optical member 210 in the groove 222 having a V-shaped cross section, the holding member 220 utilizes the sufficiently soft leaf spring rigidity of the parallel leaf spring to form the convex portion 212 and the groove. The deformation of the optical member 210 due to the frictional force generated between the optical member 210 and the optical member 222 can be reduced. Further, since the holding member 220 is movable in the radial direction, it is possible to prevent the optical member 210 from being isotropically extended from the center O and to prevent the optical member 210 from being displaced.

The groove 222 having a V-shaped cross section mounts the spherical projection 212 of the optical member 210 and holds the optical member 210. As shown in FIG. 6, the groove 222 of the holding member 220 contacts the convex portion 212 of the optical member 210 at two points C1 and C2 because the angle θ of the V-shaped cross section is approximately 90 °. The convex portion 212 of the optical member 210 is designed to contact the groove 222 of the holding member 220 at two points. Therefore, as a whole of the holding device 200, the optical member 210 is supported by the holding member 220 at six points, and the optical member 210 is kinematically supported. With this configuration, the holding device 200 can achieve desired optical performance by reducing aberrations due to deformation and displacement of the optical member 210, which deteriorates imaging performance.

位置 The position of the optical member 210 is uniquely determined because the optical member 210 is fixed to the holding member 220 by its own weight. In order to sufficiently increase the contact between the convex portion 212 of the optical member 210 and the groove 222 of the holding member 220, when it is necessary to apply pressure as well as the weight of the optical member 210, as shown in FIG. A hole 214 having a V-shaped cross section at the end may be formed in the portion 212, and pressure applying means 216 for applying pressure to the convex portion 212 through the hole 214 may be provided. The pressure applied by the pressure applying means 216 to the convex portion 212 becomes a stress acting only inside the convex portion 212, and does not generate a force for deforming the surface of the optical member 210. In addition, by forming the tip of the pressure applying means 216 as a spherical surface, the end formed in the convex portion 212 can cooperate with the hole 214 having a V-shaped cross section to bring the inside of the convex portion 212 into a stress state. Here, FIG. 6 is a schematic cross-sectional view showing the protrusion 212 of the optical member 210 and the groove 222 of the holding member 220 in a state where the holding device 200 holds the optical member 210, and FIG. FIG. 4 is a schematic cross-sectional view showing a protrusion 212 of a member 210 and a groove 222 of a holding member 220.

Further, as shown in FIG. 8, the holding device 200 drives each of the two support planes 224 and 226 forming the groove 222 of the holding member 220 in a direction perpendicular to the support planes 224 and 226. 228. The drive mechanism 228 is realized by, for example, an actuator using a piezo element or a mechanical configuration using a screw lead or the like. The drive mechanism 228 operates on the two support planes 224 and 226, respectively. Accordingly, as a whole of the holding device 200, six supporting planes can be driven, and the optical member 210 can be held with six degrees of freedom (3 translational degrees of freedom and 3 rotational degrees of freedom). Here, FIG. 8 is a schematic configuration diagram illustrating the holding device 200 in which the driving mechanism 228 is provided on the holding member 220.

Next, a holding device 200A which is a modification of the holding device 200 will be described with reference to FIGS. The holding device 200A differs from the holding device 200 in the projection 212A of the optical member 210A and the holding member 220A. Here, FIG. 9 is a schematic configuration diagram showing a holding device 200A which is a modification of the holding device 200 shown in FIG. The holding device 200A is applied to the projection optical system 530, and holds the optical member 210A via the holding member 220A, as shown in FIG.

The optical member 210A is mounted on a holding member 220A described later via the convex portion 212A, and forms an image of light using reflection, refraction, diffraction, and the like. As shown in FIG. 10, the optical member 210A has three V-shaped convex portions 212A on the outer periphery. Here, FIG. 10 is a schematic perspective view of the optical member 210A shown in FIG. The three V-shaped protrusions 212A are arranged at a pitch of 120 °. As described above, since the optical members 210A are distributed at substantially equal intervals along the circumferential direction of the optical member 210A, the optical member 210A is stabilized on the holding member 220A.

The holding member 220A has two spherical surfaces 222A and 224A that are in contact with each other so as to sandwich three V-shaped convex portions 212A provided on the outer periphery of the optical member 210A, and the optical member 210A is formed via the spherical surfaces 222A and 224A. Hold. The spherical surfaces 222A and 224A of the holding member 220A are arranged in accordance with the convex portions 212A of the optical member 210A. The two spherical surfaces 222A and 224A are configured by, for example, a parallel leaf spring or a rolling mechanism that can move only in a direction along the radial direction of the optical member 210A. Therefore, the holding member 220A can allow the optical member 210A to expand in the radial direction even when the thermal expansion of the optical member 210A occurs due to the temperature environment change due to the two spherical surfaces 222A and 224A. It is possible to prevent the displacement from occurring with respect to the shaft.

２ The two spherical surfaces 222A and 224A of the holding member 220A are placed so as to sandwich the V-shaped convex portion 212A of the optical member 210A, and hold the optical member 210A. As shown in FIG. 11, the convex portion 212A of the optical member 210A has a V-shaped angle θ of approximately 90 °, so that the convex portion 212A of the optical member 210A and the two spherical surfaces 222A and 224A of the holding member 220 Contact at two points D1 and D2. Further, the convex portion 212A of the optical member 210A is designed so as to contact the two spherical surfaces 222A and 224A of the holding member 220A at two points. Therefore, as a whole of the holding device 200A, the optical member 210A is supported by the holding member 220A at six points, thus providing kinematic support. With this configuration, the holding device 200A can achieve desired optical performance by reducing aberrations due to deformation and displacement of the optical member 210A, which deteriorates imaging performance. Here, FIG. 11 is a schematic cross-sectional view showing the convex portion 212A of the optical member 210A and the two spherical surfaces 222A and 224A of the holding member 220A in a state where the holding device 200A holds the optical member 210A.

Hereinafter, an exemplary exposure apparatus 500 of the present invention will be described with reference to FIG. Here, FIG. 12 is a schematic configuration diagram of an exemplary exposure apparatus 500 of the present invention. The exposure apparatus 500 of the present invention uses the EUV light (for example, a wavelength of 13.4 nm) as the exposure illumination light to convert the circuit pattern formed on the mask 520 by the step-and-scan method or the step-and-repeat method. This is a projection exposure apparatus that exposes an object to be processed 540. Such an exposure apparatus is suitable for a submicron or quarter-micron lithography process. Hereinafter, in this embodiment, a step-and-scan type exposure apparatus (also referred to as a “scanner”) will be described as an example. Here, in the step-and-scan method, the wafer is continuously scanned (scanned) with respect to the mask to expose the mask pattern to the wafer, and after the exposure of one shot is completed, the wafer is step-moved. This is an exposure method for moving to an exposure area. The step-and-repeat method is an exposure method in which the wafer is step-moved for each batch exposure of the wafer and moves to the exposure area of the next shot.

Referring to FIG. 12, an exposure apparatus 500 mounts an illumination device 510, a mask 520, a mask stage 525 on which the mask 520 is mounted, a projection optical system 530, an object to be processed 540, and an object to be processed 540. It has a wafer stage 545 to be placed, an alignment detection mechanism 550, and a focus position detection mechanism 560.

As shown in FIG. 12, since EUV light has a low transmittance to the atmosphere, it is preferable that at least an optical path through which EUV light passes is a vacuum atmosphere VC.

The illumination device 510 illuminates the mask 720 with arc-shaped EUV light (for example, a wavelength of 13.4 nm) with respect to the arc-shaped field of view of the projection optical system 530, and includes an EUV light source 512 and an illumination optical system 514. Be composed.

(4) As the EUV light source 512, for example, a laser plasma light source is used. In this method, a high-intensity pulsed laser beam is irradiated to a target material in a vacuum vessel to generate high-temperature plasma, and EUV light having a wavelength of, for example, about 13 nm emitted from the plasma is used. As the target material, a metal film, a gas jet, a droplet, or the like is used. In order to increase the average intensity of the emitted EUV light, the repetition frequency of the pulse laser is preferably high, and the operation is usually performed at a repetition frequency of several kHz.

The illumination optical system 514 includes a condenser mirror 512a and an optical integrator 512b. The condensing mirror 512a plays a role of collecting EUV light emitted almost isotropically from the laser plasma. The optical integrator 512b has a role of illuminating the mask 520 uniformly with a predetermined numerical aperture. The illumination optical system 514 is provided with an aperture 513c at a position conjugate with the mask 520 to limit the illumination area of the mask 520 to an arc shape. The holding devices 100, 200, and 200A of the present invention (hereinafter, the "holding device 100") include the holding devices 200 and 200A for holding optical members such as the condenser mirror 512a and the optical integrator 512b of the illumination optical system 514. ) Can be used.

The mask 520 is a reflective mask on which a circuit pattern (or image) to be transferred is formed, and is supported and driven by a mask stage 525. The diffracted light emitted from the mask 520 is reflected by the projection optical system 530 and projected onto the object 540. The mask 520 and the object to be processed 540 are arranged in an optically conjugate relationship. Since the exposure apparatus 500 is a step-and-scan exposure apparatus, it scans the mask 520 and the object 540 to reduce and project the pattern of the mask 520 onto the object 540.

The mask stage 525 supports the mask 520 and is connected to a moving mechanism (not shown). As the mask stage 525, any configuration known in the art can be applied. The moving mechanism (not shown) is configured by a linear motor or the like, and can move the mask 520 by driving the mask stage 525 at least in the X direction. The exposure apparatus 500 scans the mask 520 and the object 540 in synchronization. Here, the scanning direction in the mask 520 or the object 540 is X, the direction perpendicular to the scanning direction is Y, and the direction perpendicular to the mask 520 or the object 540 is Z.

The projection optical system 530 uses a plurality of reflection mirrors (that is, multilayer mirrors) 530a to reduce and project the pattern on the mask 520 onto the object 540 as an image plane. The number of mirrors 530a is about four to six. In order to realize a wide exposure area with a small number of mirrors, the mask 520 and the object 540 are simultaneously scanned by using only a thin arc-shaped area (ring field) separated by a certain distance from the optical axis. Transfer a large area. The numerical aperture (NA) of the projection optical system 530 is about 0.1 to 0.2.

保持 The holding device 100 of the present invention can be used to hold an optical member such as a mirror 530a constituting the projection optical system 530. The holding device 100 is connected to the lens barrel of the projection optical system 530 by a spring member (not shown). With such a configuration, it is possible to prevent the holding member 100 from being eccentric with respect to the lens barrel due to a relative displacement between the lens barrel and the holding member 100 caused by a difference in linear expansion coefficient during a temperature environment change such as transportation of the apparatus. Can be prevented. Note that the holding device 100 has the above-described configuration, and a detailed description thereof will be omitted. Therefore, the projection optical system 530 can reduce aberration due to deformation and displacement of the optical member, which deteriorates imaging performance, and can achieve desired optical performance.

The target object 540 is a wafer in the present embodiment, but widely includes a liquid crystal substrate and other target objects. A photoresist is applied to the object 540. The photoresist application step includes a pretreatment, an adhesion improver application process, a photoresist application process, and a pre-bake process. The pretreatment includes washing, drying, and the like. The adhesion improver application treatment is a surface modification treatment (that is, a hydrophobic treatment by applying a surfactant) for increasing the adhesion between the photoresist and the base, and the organic film such as HMDS (Hexamethyl-disilazane) is treated. Coat or steam. Prebaking is a baking (firing) step, but is softer than that after development, and removes the solvent.

The wafer stage 545 supports the object 540 by the wafer chuck 545a. The wafer stage 545 moves the object 540 in the XYZ directions using, for example, a linear motor. The mask 520 and the object 540 are scanned synchronously. The position of the mask stage 525 and the position of the wafer stage 545 are monitored by, for example, a laser interferometer, and both are driven at a constant speed ratio.

The alignment detecting mechanism 550 measures the positional relationship between the position of the mask 520 and the optical axis of the projection optical system 530, and the positional relationship between the position of the processing target 540 and the optical axis of the projection optical system 530. The positions and angles of the mask stage 525 and the wafer stage 545 are set so that the projected image matches a predetermined position of the object 540.

The focus position detection mechanism 560 measures the focus position in the Z direction on the surface of the processing object 540 and controls the position and angle of the wafer stage 545 so that the surface of the processing object 545 is constantly exposed by the projection optical system 530 during exposure. Keep at the imaging position.

In the exposure, the EUV light emitted from the illumination device 510 illuminates the mask 520 and forms a pattern on the mask 520 on the object 540. In the present embodiment, the image plane is an arc-shaped (ring-shaped) image plane, and the entire surface of the mask 520 is exposed by scanning the mask 520 and the object 540 at a reduction ratio.

Next, an embodiment of a device manufacturing method using the above-described exposure apparatus 500 will be described with reference to FIGS. FIG. 13 is a flowchart for explaining the manufacture of devices (semiconductor chips such as ICs and LSIs, LCDs, CCDs, and the like). Here, the manufacture of a semiconductor chip will be described as an example. In step 1 (circuit design), the circuit of the device is designed. Step 2 (mask fabrication) forms a mask on which the designed circuit pattern is formed. In step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is referred to as a preprocess, and an actual circuit is formed on the wafer by lithography using the mask and the wafer. Step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer created in step 4, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). Including. In step 6 (inspection), inspections such as an operation check test and a durability test of the semiconductor device created in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 14 is a detailed flowchart of the wafer process in Step 4. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the surface of the wafer. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the exposure apparatus 500 to expose a circuit pattern on the mask onto the wafer. Step 17 (development) develops the exposed wafer. Step 18 (etching) removes portions other than the developed resist image. Step 19 (resist stripping) removes unnecessary resist after etching. By repeating these steps, multiple circuit patterns are formed on the wafer. According to the device manufacturing method of the present embodiment, it is possible to manufacture a higher-quality device than before. As described above, the device manufacturing method using the exposure apparatus 500 and the resulting device also constitute one aspect of the present invention.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the gist. For example, the holding device of the present invention may be used to support a mask or a wafer.

It is a schematic structure figure showing the holding device as one side of the present invention. FIG. 2 is a schematic perspective view of the optical member shown in FIG. 1. FIG. 2 is a schematic cross-sectional view illustrating a first groove of an optical member, a second groove of a support member, and a second groove of a fixing member in a state where the holding device illustrated in FIG. 1 holds the optical member. It is a schematic structure figure showing another holding device as one side of the present invention. FIG. 5 is a schematic perspective view of the optical member shown in FIG. 4. FIG. 5 is a schematic cross-sectional view illustrating a protrusion of the optical member and a groove of the holding member in a state where the holding device illustrated in FIG. 4 holds the optical member. FIG. 4 is a schematic cross-sectional view illustrating a convex portion of an optical member having a pressure applying unit and a groove of a holding member. It is a schematic structure figure showing the holding device provided with the drive mechanism in the holding member. It is a schematic structure figure showing the holding device which is a modification of the holding device shown in Drawing 4. It is a schematic perspective view of the optical member shown in FIG. FIG. 10 is a schematic cross-sectional view illustrating two spherical surfaces of a projection of the optical member and a holding member in a state where the holding device illustrated in FIG. 9 holds the optical member. FIG. 1 is a schematic configuration diagram of an exemplary exposure apparatus of the present invention. 6 is a flowchart for explaining the manufacture of a device (a semiconductor chip such as an IC or LSI, an LCD, a CCD, or the like). 14 is a detailed flowchart of the wafer process in Step 4 shown in FIG. FIG. 2 is a plan view showing a variation of a first groove formed in the holding device shown in FIG. 1. It is a top view which shows the variation of the 1st groove | channel formed in the holding device shown in FIG. 1, (a) is a case where a 1st groove | channel is one spiral groove | channel, (b) is the 1st groove | channel. The case where one groove is three spiral grooves is shown.

Explanation of reference numerals

100: holding device 110: optical members 116, 116A, 116a, 116B, 116b, 116c, 116D: first groove 120: support member 130: fixing member 132: second groove 200: holding device 210: optical member 212: Convex part 214: Hole 216: Pressure applying means 220: Holding member 222: Grooves 224, 226: Support plane 228: Driving mechanism 200A: Holding device 210A: Optical member 212A: Convex part 220A: Holding members 222A, 224A: Spherical surface 500: Exposure device 510: illumination device 514: illumination optical system 520: mask 530: projection optical system 540: object to be processed 550: alignment detection mechanism 560: focus position detection mechanism

Claims (33)

A holding device for holding an optical member having three first grooves,
A first support member that supports the optical member via the first groove;
A holding device comprising: three second grooves corresponding to the first grooves; and a second support member that supports the first support member via the second grooves. . The holding device according to claim 1, wherein the first groove is a linear groove along a radial direction. The holding device according to claim 1, wherein the three first grooves or their extensions intersect at substantially one point. The holding device according to claim 1, wherein the three second grooves or their extensions intersect at substantially one point. The holding device according to claim 1, wherein at least one of the three first grooves or the three second grooves has a spiral shape. A point where one of the three first grooves or an extension thereof intersects with the other first groove or an extension thereof, and a point where the one first groove or the extension thereof intersects the other first groove or the extension thereof. The holding device according to claim 1, wherein a point at which the groove intersects the groove or an extension of the groove is different. A point at which one of the three second grooves or an extension thereof intersects another second groove or an extension thereof, and a point at which the one second groove or the extension thereof intersects the remaining second groove or the extension thereof. 2. The holding device according to claim 1, wherein a point at which the groove intersects with the groove or an extension thereof is different. The holding device according to claim 3, wherein the substantially one point is a center of the optical member. The holding device according to claim 3, wherein the substantially one point is a point other than the center of the optical member. The holding device according to claim 1, wherein the three second grooves or their extensions intersect at substantially one point. The holding device according to claim 1, wherein the three first grooves form 120 degrees with each other, and the three second grooves form 120 degrees with each other. The holding device according to claim 1, wherein the first groove and the second groove have a V-shaped cross section. 13. The holding device according to claim 12, wherein the V-shaped cross section has an angle of substantially 90 °. The holding device according to claim 1, wherein the first support member has a true spherical shape. The holding device according to claim 2, wherein the first support member is capable of rolling along the first groove and the second groove. The holding device according to claim 1, wherein the optical member contacts the first support member at a position 60% to 70% of a radius of the optical member from a center of the optical member. A holding device for holding an optical member having three spherical convex portions on an outer periphery,
A groove having a substantially V-shaped cross section for mounting the spherical protrusion in a direction along the radial direction of the optical member, and a holding member for holding the optical member through the groove. Characteristic holding device. 18. The holding device according to claim 17, wherein the holding member is movable in a radial direction of the optical member. 18. The holding device according to claim 17, wherein the three spherical projections are arranged at a pitch of 120 degrees with respect to the center of the optical member. 18. The holding device according to claim 17, further comprising: a driving mechanism that drives each of the two support planes forming the groove in a direction perpendicular to the support plane. 18. The holding device according to claim 17, wherein the convex portion has a hole having a V-shaped cross section, and further includes a pressure applying unit that applies pressure to the spherical surface through the hole. A holding device for holding an optical member having three V-shaped convex portions on the outer periphery,
A holding device, comprising: two spherical portions that are in contact with each other so as to sandwich the V-shaped convex portion, and a holding member that holds the optical member via the spherical portions. 23. The holding device according to claim 22, wherein the holding member is movable in a direction along a radial direction of the optical member. 23. The holding device according to claim 22, wherein the three V-shaped protrusions are arranged at a pitch of 120 degrees with respect to the center of the optical member. The holding device according to claim 1, wherein the optical member is a mirror. An exposure apparatus comprising the holding device according to claim 2, and having an optical system for exposing a pattern formed on a mask or a reticle to an object to be processed via an optical member held by the holding device. An exposure apparatus comprising: the holding device according to claim 3; and an optical system for exposing a pattern formed on a mask or a reticle to an object to be processed through an optical member held by the holding device. An exposure apparatus comprising: the holding device according to claim 17; and an optical system configured to expose a pattern formed on a mask or a reticle to an object to be processed via an optical member held by the holding device. An exposure apparatus, comprising: the holding device according to claim 22; and an optical system that exposes an object to be processed with a pattern formed on a mask or a reticle via an optical member held by the holding device. Projecting and exposing an object to be processed using the exposure apparatus according to claim 26;
Performing a predetermined process on the object subjected to the projection exposure. Projecting and exposing an object to be processed using the exposure apparatus according to claim 27;
Performing a predetermined process on the object subjected to the projection exposure. Projecting and exposing an object to be processed using the exposure apparatus according to claim 28;
Performing a predetermined process on the object subjected to the projection exposure. Projecting and exposing an object to be processed using the exposure apparatus according to claim 29;
Performing a predetermined process on the object subjected to the projection exposure.

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