JP2006135165A - Exposure apparatus and method of manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus capable of suppressing the leakage or residue of liquid. <P>SOLUTION: This exposure apparatus comprises a first stage ST1 and a second stage ST2 independently movable in the XY plane on the image surface side of a projection optical system PL, a drive mechanism for moving the first and second stages together in a state they are in proximity to or contact with each other, and a liquid immersion mechanism for forming a liquid immersion region according to the liquid on the upper surface of at least one stage of the first and second stages. When the liquid immersion region is moved from the upper surface of one stage to the upper surface of the other stage, the upper surface of the one stage is made higher than that of the other stage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exposure apparatus and a device manufacturing method for exposing a substrate through a projection optical system.

In a photolithography process that is one of the manufacturing processes of microdevices such as semiconductor devices and liquid crystal display devices, an exposure apparatus that projects and exposes a pattern formed on a mask onto a photosensitive substrate is used. This exposure apparatus has a mask stage for supporting a mask and a substrate stage for supporting a substrate, and projects the mask pattern onto the substrate via a projection optical system while sequentially moving the mask stage and the substrate stage. is there. Some exposure apparatuses include two stages that can move independently from each other on the image plane side of the projection optical system for the purpose of improving throughput. In the manufacture of micro devices, miniaturization of patterns formed on a substrate is required in order to increase the density of devices. In order to meet this demand, it is desired to further increase the resolution of the exposure apparatus. As one of means for realizing the high resolution, the liquid immersion area is formed by filling the space between the projection optical system and the substrate as disclosed in Patent Document 1 below. An immersion exposure apparatus has been devised that performs an exposure process through a region of liquid.
International Publication No. 99/49504 Pamphlet

  When liquid leaks or remains, the environment (humidity, etc.) in which the exposure apparatus is placed fluctuates due to the leakage or residual liquid, or each member constituting the exposure apparatus by heat of vaporization when the liquid evaporates There is a possibility that the exposure temperature and measurement accuracy may be affected. In addition, the leaked or remaining liquid may damage various devices constituting the exposure apparatus, cause rusting, or contaminate each member constituting the exposure apparatus with watermarks formed when the liquid evaporates. There is a risk of inconvenience such as

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide an exposure apparatus and a device manufacturing method that can suppress leakage and residual liquid.

  In order to solve the above-described problems, the present invention adopts the following configuration corresponding to FIGS. 1 to 7 shown in the embodiment. However, the reference numerals with parentheses attached to each element are merely examples of the element and do not limit each element.

  According to the first aspect of the present invention, in the exposure apparatus that exposes the substrate (P) through the projection optical system (PL), the image plane side of the projection optical system (PL) is substantially parallel to the image plane. The first stage (ST1) and the second stage (ST2) that can move independently from each other in the dimensional plane (in the XY plane), and the first stage (ST1) and the second stage (ST2) are brought close to or in contact with each other. In this state, a drive mechanism (SD) that moves the first stage (ST1) and the second stage (ST2) together within a predetermined area including a position directly below the projection optical system (PL), and a first stage (ST1) ) And the second stage (ST2) and a liquid immersion mechanism (1) for forming a liquid immersion area (LR) of the liquid (LQ) on the upper surface (F1, F2) of the first stage (ST1). ) And the second stage (ST2) In the state where the liquid (LQ) is held between the projection optical system (PL) and the upper surface of at least one stage, the liquid immersion region (LR) is moved to the upper surface (ST1) of the first stage (ST1). F1) and the upper surface (F2) of the second stage (ST2), and of the first stage (ST1) and the second stage (ST2), the upper surface of one stage to the upper surface of the other stage An exposure apparatus (EX) is provided that moves the upper surface of one stage higher than the upper surface of the other stage when moving the liquid immersion region (LR).

  According to the first aspect of the present invention, when the liquid immersion region is moved from the upper surface of one stage to the upper surface of the other stage of the first stage and the second stage, the upper surface of one stage is moved to the other stage. By making the height higher than the upper surface, it is possible to prevent liquid from leaking out from between the first stage and the second stage or from remaining on the stage. Therefore, good exposure accuracy and measurement accuracy can be maintained.

  According to the second aspect of the present invention, a device manufacturing method using the exposure apparatus (EX) of the above aspect is provided.

  According to the second aspect of the present invention, since the exposure process and the measurement process can be performed satisfactorily, a device having a desired performance can be manufactured.

  According to the present invention, since leakage and residual liquid can be suppressed, exposure accuracy and measurement accuracy can be maintained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

<First Embodiment>
FIG. 1 is a schematic block diagram that shows an exposure apparatus according to the first embodiment. In FIG. 1, an exposure apparatus EX is mounted with a mask stage MST that can move while holding a mask M, a substrate stage ST1 that can move while holding a substrate P, and a measuring instrument that performs measurement related to exposure processing. Possible measurement stage ST2, illumination optical system IL for illuminating mask M held on mask stage MST with exposure light EL, and pattern image of mask M illuminated with exposure light EL are held on substrate stage ST1. A projection optical system PL that performs projection exposure on the substrate P, and a control device CONT that controls the overall operation of the exposure apparatus EX. Each of the substrate stage ST1 and the measurement stage ST2 is supported so as to be movable on the base member BP, and is movable independently of each other. The lower surface U1 of the substrate stage ST1 is provided with a gas bearing 41 for supporting the substrate stage ST1 in a non-contact manner with respect to the upper surface BT of the base member BP. Similarly, a gas bearing 42 for supporting the measurement stage ST2 in a non-contact manner with respect to the upper surface BT of the base member BP is also provided on the lower surface U2 of the measurement stage ST2. Each of the substrate stage ST1 and the measurement stage ST2 can move independently of each other within a two-dimensional plane (XY plane) substantially parallel to the image plane on the image plane side of the projection optical system PL.

  The exposure apparatus EX of the present embodiment is an immersion exposure apparatus to which an immersion method is applied in order to substantially shorten the exposure wavelength to improve the resolution and substantially widen the depth of focus. An immersion mechanism 1 for forming an immersion area LR of the liquid LQ on the image plane side of the PL is provided. The liquid immersion mechanism 1 is provided in the vicinity of the image plane side of the projection optical system PL. The nozzle member 70 includes a supply port 12 for supplying the liquid LQ and a recovery port 22 for recovering the liquid LQ. The liquid supply mechanism 10 that supplies the liquid LQ to the image plane side of the projection optical system PL via the supply port 12 and the liquid LQ on the image plane side of the projection optical system PL via the recovery port 22 provided in the nozzle member 70. And a liquid recovery mechanism 20 for recovering the liquid. The nozzle member 70 is formed in an annular shape so as to surround the image plane side tip of the projection optical system PL. While transferring at least the pattern image of the mask M onto the substrate P, the exposure apparatus EX uses a liquid LQ supplied from the liquid supply mechanism 10 to a part on the substrate P including the projection area AR of the projection optical system PL. An immersion region LR of the liquid LQ that is larger than the projection region AR and smaller than the substrate P is locally formed. Specifically, the exposure apparatus EX has an optical path between the first optical element LS1 closest to the image plane of the projection optical system PL and a part of the surface of the substrate P arranged on the image plane side of the projection optical system PL. A local immersion method for filling the space with the liquid LQ is adopted, and the substrate P is irradiated with the exposure light EL that has passed through the mask M via the liquid LQ between the projection optical system PL and the substrate P and the projection optical system PL. Thereby, the pattern of the mask M is projected and exposed onto the substrate P.

  In the present embodiment, the exposure apparatus EX is a scanning exposure apparatus (so-called so-called exposure apparatus EX) that exposes the pattern formed on the mask M onto the substrate P while synchronously moving the mask M and the substrate P in different directions (reverse directions) in the scanning direction. A case where a scanning stepper) is used will be described as an example. In the following description, the synchronous movement direction (scanning direction) of the mask M and the substrate P in the horizontal plane is the X-axis direction, the direction orthogonal to the X-axis direction in the horizontal plane is the Y-axis direction (non-scanning direction), the X-axis, and A direction perpendicular to the Y-axis direction and coincident with the optical axis AX of the projection optical system PL is defined as a Z-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively. Here, the “substrate” includes a substrate in which a photosensitive material (resist) is coated on a base material such as a semiconductor wafer, and the “mask” includes a reticle on which a device pattern to be reduced and projected on the substrate is formed.

  Each of the substrate stage ST1 and the measurement stage ST2 can be moved by driving a drive mechanism SD including a linear motor and the like. The control device CONT controls the drive mechanism SD, so that the substrate stage ST1 and the measurement stage ST2 are within a predetermined region including directly under the projection optical system PL in a state where the substrate stage ST1 and the measurement stage ST2 are close to or in contact with each other. Can be moved together in the XY plane. The control device CONT moves the substrate stage ST1 and the measurement stage ST2 together, thereby supplying the liquid LQ between the projection optical system PL and at least one of the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the measurement stage ST2. In the held state, the immersion area LR can be moved between the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the second stage ST2.

  In the present embodiment, an upper region (a region including the upper surface F1) of the side surface of the substrate stage ST1 is an overhang portion H1 that protrudes outward from the central portion of the upper surface F1. Similarly, the upper region (region including the upper surface F2) of the side surface of the measurement stage ST2 is an overhang portion H2 that protrudes outward from the central portion of the upper surface F2. A region on the + Y side of the upper surface F1 of the substrate stage ST1 and a region on the −Y side of the upper surface F2 of the measurement stage ST2 are close to or in contact with each other.

  Here, the state in which the substrate stage ST1 and the measurement stage ST2 are “close to each other” means that the substrate stage is moved when the liquid immersion region LR is moved between the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the second stage ST2. A state in which the liquid LQ is close enough not to leak from between ST1 and measurement stage ST2, and the allowable value of the interval between both stages ST1 and ST2 depends on the material and surface treatment of both stages, the type of liquid LQ, etc. Different.

  Further, when the exposure apparatus EX moves the liquid immersion region LR from one upper surface F1 (F2) of the substrate stage ST1 and measurement stage ST2 to the other upper surface F2 (F1), the upper surface of one stage ST1 (ST2). F1 (F2) is set higher than the upper surface F2 (F1) of the other stage ST2 (ST1).

The illumination optical system IL includes an exposure light source, an optical integrator that equalizes the illuminance of a light beam emitted from the exposure light source, a condenser lens that collects the exposure light EL from the optical integrator, a relay lens system, and the exposure light EL. A field stop for setting an illumination area on the mask M is provided. A predetermined illumination area on the mask M is illuminated with the exposure light EL having a uniform illuminance distribution by the illumination optical system IL. As the exposure light EL emitted from the illumination optical system IL, for example, far ultraviolet light (g-line, h-line, i-line) and KrF excimer laser light (wavelength 248 nm) emitted from a mercury lamp, DUV light), vacuum ultraviolet light (VUV light) such as ArF excimer laser light (wavelength 193 nm) and F ₂ laser light (wavelength 157 nm), or the like is used. In this embodiment, ArF excimer laser light is used.

  In the present embodiment, pure water is used as the liquid LQ. Pure water is not only ArF excimer laser light, but also, for example, far ultraviolet light (DUV) such as ultraviolet emission lines (g-line, h-line, i-line) and KrF excimer laser light (wavelength 248 nm) emitted from a mercury lamp. Light) can also be transmitted.

  Mask stage MST is movable while holding mask M. Mask stage MST holds mask M by vacuum suction (or electrostatic suction). The mask stage MST is in a plane perpendicular to the optical axis AX of the projection optical system PL, that is, in the XY plane, while holding the mask M by driving a drive mechanism MD including a linear motor and the like controlled by the control device CONT. Can be moved two-dimensionally and can be rotated slightly in the θZ direction. A movable mirror 31 is provided on the mask stage MST. A laser interferometer 32 is provided at a position facing the moving mirror 31. The position of the mask M on the mask stage MST in the two-dimensional direction and the rotation angle in the θZ direction (including rotation angles in the θX and θY directions in some cases) are measured by the laser interferometer 32 in real time. The measurement result of the laser interferometer 32 is output to the control device CONT. The control device CONT drives the drive mechanism MD based on the measurement result of the laser interferometer 32 and controls the position of the mask M held on the mask stage MST.

  The projection optical system PL projects and exposes the pattern of the mask M onto the substrate P at a predetermined projection magnification β, and is composed of a plurality of optical elements, which are held by a lens barrel PK. . In the present embodiment, the projection optical system PL is a reduction system having a projection magnification β of, for example, 1/4, 1/5, or 1/8. Note that the projection optical system PL may be either an equal magnification system or an enlargement system. Of the plurality of optical elements constituting the projection optical system PL, the first optical element LS1 closest to the image plane of the projection optical system PL is exposed from the lens barrel PK.

  The substrate stage ST1 has a substrate holder PH that holds the substrate P, and the substrate holder PH can be moved on the image plane side of the projection optical system PL. The substrate holder PH holds the substrate P by, for example, vacuum suction. A recess 36 is provided on the substrate stage ST1, and a substrate holder PH for holding the substrate P is disposed in the recess 36. The upper surface F1 of the substrate stage ST1 other than the recess 36 is a flat surface (flat portion) that is substantially the same height (level) as the surface of the substrate P held by the substrate holder PH.

  The substrate stage ST1 projects projection optics on the image plane side of the projection optical system PL in a state where the substrate P is held via the substrate holder PH by driving a drive mechanism SD including a linear motor and the like controlled by the control device CONT. It can be moved two-dimensionally in an XY plane substantially parallel to the image plane of the system PL and can be slightly rotated in the θZ direction. Furthermore, the substrate stage ST1 is also movable in the Z-axis direction, the θX direction, and the θY direction. Therefore, the surface of the substrate P supported by the substrate stage ST1 can move in directions of six degrees of freedom in the X axis, Y axis, Z axis, θX, θY, and θZ directions. A movable mirror 33 is provided on the side surface of the substrate stage ST1. A laser interferometer 34 is provided at a position facing the movable mirror 33. The two-dimensional position and rotation angle of the substrate P on the substrate stage ST1 are measured in real time by the laser interferometer 34. Further, the exposure apparatus EX is an oblique incidence type focus / leveling detection system for detecting surface position information of the surface of the substrate P supported by the substrate stage ST1, as disclosed in, for example, Japanese Patent Application Laid-Open No. 8-37149. (Not shown). The focus / leveling detection system detects surface position information (position information in the Z-axis direction and inclination information of the substrate P in the θX and θY directions). As the focus / leveling detection system, a system using a capacitive sensor may be adopted. The measurement result of the laser interferometer 34 is output to the control device CONT. The detection result of the focus / leveling detection system is also output to the control device CONT. The control device CONT drives the drive mechanism SD based on the detection result of the focus / leveling detection system, and controls the focus position (Z position) and the tilt angle (θX, θY) of the substrate P to automate the surface of the substrate P. The position is controlled in the X-axis direction, the Y-axis direction, and the θZ direction of the substrate P based on the measurement result of the laser interferometer 34 while being adjusted to the image plane of the projection optical system PL by the focus method and the auto-leveling method. .

  The measurement stage ST2 is mounted with various measuring instruments (including measurement members) that perform measurement related to the exposure process, and is movable on the image plane side of the projection optical system PL. As this measuring instrument, as disclosed in, for example, Japanese Patent Laid-Open No. 5-21314, a reference mark plate on which a plurality of reference marks are formed, for example, disclosed in Japanese Patent Laid-Open No. 57-117238. Non-uniformity sensor for measuring illuminance non-uniformity or measuring the variation of the transmittance of the exposure light EL of the projection optical system PL as disclosed in JP-A-2001-267239, JP-A-2002-14005 And a dose sensor (illuminance sensor) as disclosed in Japanese Patent Application Laid-Open No. 11-16816. The upper surface F2 of the measurement stage ST2 is a flat surface (flat portion), like the upper surface F1 of the substrate stage ST1.

  In the present embodiment, the above-described unevenness sensor used for the measurement using the exposure light EL in response to the immersion exposure for exposing the substrate P by the exposure light EL through the projection optical system PL and the liquid LQ. In the aerial image measurement sensor, the irradiation amount sensor, etc., the exposure light EL is received through the projection optical system PL and the liquid LQ. In addition, for example, only a part of the optical system of each sensor may be mounted on the measurement stage ST2, or the entire sensor may be disposed on the measurement stage ST2.

  The measurement stage ST2 is connected to the image plane of the projection optical system PL on the image plane side of the projection optical system PL in a state in which a measuring instrument is mounted by driving a drive mechanism SD including a linear motor and the like controlled by the control device CONT. It can be moved two-dimensionally in an almost parallel XY plane and can be rotated slightly in the θZ direction. Furthermore, the measurement stage ST2 can move in the Z-axis direction, the θX direction, and the θY direction. That is, the measurement stage ST2 can also move in directions of six degrees of freedom in the X axis, Y axis, Z axis, θX, θY, and θZ directions, like the substrate stage ST1. A movable mirror 37 is provided on the side surface of the measurement stage ST2. A laser interferometer 38 is provided at a position facing the movable mirror 37. The position and rotation angle of the measurement stage ST2 in the two-dimensional direction are measured by the laser interferometer 38 in real time.

  In the figure, the movable mirrors 33 and 37 are provided in the overhang portions H1 and H2 of the stages ST1 and ST2, but may be provided in a region below the overhang portion. By doing so, even if the liquid LQ flows out from the upper surfaces F1 and F2, it is possible to prevent the liquid LQ from adhering to the movable mirrors 33 and 37 by the overhang portions H1 and H2.

  An off-axis alignment system ALG that detects an alignment mark on the substrate P and a reference mark on the reference mark plate is provided near the tip of the projection optical system PL. In the alignment system ALG of the present embodiment, for example, as disclosed in Japanese Patent Laid-Open No. 4-65603, a target detection mark is irradiated with a broadband detection light beam that does not expose the photosensitive material on the substrate P, and the target mark is irradiated. An image of the target mark imaged on the light receiving surface by the reflected light and an image of an index (not shown) (an index pattern on an index plate provided in the alignment system ALG) are captured using an image sensor (CCD or the like). An FIA (Field Image Alignment) method is employed in which the position of the mark is measured by performing image processing on these image pickup signals.

  Further, in the vicinity of the mask stage MST, a TTR system using light of an exposure wavelength for simultaneously observing the alignment mark on the mask M and the corresponding reference mark on the reference mark plate via the projection optical system PL. A pair of mask alignment systems RAa and RAb made of an alignment system are provided at a predetermined distance in the Y-axis direction. In the mask alignment system of this embodiment, for example, as disclosed in Japanese Patent Laid-Open No. 7-176468, the mark is irradiated with light, and the mark image data captured by a CCD camera or the like is subjected to image processing and the mark is processed. A VRA (Visual Reticle Alignment) method for detecting the position is adopted.

  Next, the liquid supply mechanism 10 and the liquid recovery mechanism 20 of the liquid immersion mechanism 1 will be described. The liquid supply mechanism 10 is for supplying the liquid LQ to the image plane side of the projection optical system PL, and connects the liquid supply unit 11 capable of delivering the liquid LQ and one end thereof to the liquid supply unit 11. And a supply pipe 13. The other end of the supply pipe 13 is connected to the nozzle member 70. Inside the nozzle member 70, an internal flow path (supply flow path) that connects the other end of the supply pipe 13 and the supply port 12 is formed. The liquid supply unit 11 includes a tank that stores the liquid LQ, a pressure pump, a filter unit that removes foreign matter in the liquid LQ, and the like. The liquid supply operation of the liquid supply unit 11 is controlled by the control device CONT.

  The liquid recovery mechanism 20 is for recovering the liquid LQ on the image plane side of the projection optical system PL, and has a liquid recovery part 21 that can recover the liquid LQ and one end connected to the liquid recovery part 21. And a recovery pipe 23. The other end of the recovery pipe 23 is connected to the nozzle member 70. Inside the nozzle member 70, an internal flow path (recovery flow path) that connects the other end of the recovery pipe 23 and the recovery port 22 is formed. The liquid recovery unit 21 includes, for example, a vacuum system (a suction device) such as a vacuum pump, a gas-liquid separator that separates the recovered liquid LQ and gas, and a tank that stores the recovered liquid LQ.

  The supply port 12 for supplying the liquid LQ and the recovery port 22 for recovering the liquid LQ are formed on the lower surface 70 </ b> A of the nozzle member 70. The lower surface 70A of the nozzle member 70 is provided at a position facing the surface of the substrate P and the upper surfaces F1 and F2 of the stages ST1 and ST2. The nozzle member 70 is an annular member provided so as to surround the side surface of the first optical element LS1, and the supply port 12 is provided on the lower surface 70A of the nozzle member 70 with the first optical element LS1 (projection) of the projection optical system PL. A plurality are provided so as to surround the optical axis AX) of the optical system PL. The recovery port 22 is provided outside the supply port 12 with respect to the first optical element LS1 on the lower surface 70A of the nozzle member 70, and is provided so as to surround the first optical element LS1 and the supply port 12. ing.

  The control device CONT supplies a predetermined amount of the liquid LQ onto the substrate P using the liquid supply mechanism 10 and recovers the predetermined amount of the liquid LQ on the substrate P using the liquid recovery mechanism 20. A liquid immersion region LR of the liquid LQ is locally formed on the top. When forming the liquid immersion region LR of the liquid LQ, the control device CONT drives each of the liquid supply unit 11 and the liquid recovery unit 21. When the liquid LQ is delivered from the liquid supply unit 11 under the control of the control device CONT, the liquid LQ delivered from the liquid supply unit 11 flows through the supply pipe 13 and then the supply flow path of the nozzle member 70. Then, the image is supplied from the supply port 12 to the image plane side of the projection optical system PL. When the liquid recovery unit 21 is driven under the control device CONT, the liquid LQ on the image plane side of the projection optical system PL flows into the recovery flow path of the nozzle member 70 via the recovery port 22, and the recovery pipe After flowing through 23, the liquid is recovered by the liquid recovery unit 21.

  FIG. 2 is a view of the substrate stage ST1 and the measurement stage ST2 as viewed from above. In FIG. 2, the drive mechanism SD for driving the substrate stage ST1 and the measurement stage ST2 includes linear motors 80, 81, 82, 83, 84, 85. The drive mechanism SD includes a pair of Y-axis linear guides 91 and 93 extending in the Y-axis direction. Each of the Y-axis linear guides 91 and 93 is disposed at a predetermined interval in the X-axis direction. Each of the Y-axis linear guides 91 and 93 is constituted by, for example, a magnet unit containing a permanent magnet group composed of a plurality of N-pole magnets and S-pole magnets arranged alternately at a predetermined interval along the Y-axis direction. Has been. On one Y-axis linear guide 91, two sliders 90 and 94 are supported so as to be movable in the Y-axis direction in a non-contact state. Similarly, two sliders 92 and 95 are supported on the other Y-axis linear guide 93 so as to be movable in the Y-axis direction in a non-contact state. Each of the sliders 90, 92, 94, and 95 is configured by a coil unit that incorporates armature coils arranged at predetermined intervals along the Y axis, for example. That is, in the present embodiment, the moving coil type Y-axis linear motors 82 and 84 are configured by the sliders 90 and 94 made of a coil unit and the Y-axis linear guide 91 made of a magnet unit, respectively. Similarly, the sliders 92 and 95 and the Y-axis linear guide 93 constitute moving coil type Y-axis linear motors 83 and 85, respectively.

  The sliders 90 and 92 constituting the Y-axis linear motors 82 and 83 are fixed to one end and the other end in the longitudinal direction of the X-axis linear guide 87 extending in the X-axis direction. The sliders 94 and 95 that constitute the Y-axis linear motors 84 and 85 are fixed to one end and the other end in the longitudinal direction of the X-axis linear guide 89 extending in the X-axis direction. Therefore, the X-axis linear guide 87 can be moved in the Y-axis direction by the Y-axis linear motors 82 and 83, and the X-axis linear guide 89 can be moved in the Y-axis direction by the Y-axis linear motors 84 and 85.

  Each of the X-axis linear guides 87 and 89 is configured by, for example, a coil unit that incorporates armature coils arranged at predetermined intervals along the X-axis direction. The X-axis linear guide 89 is provided in an inserted state in an opening formed in the substrate stage ST1. Inside the opening of the substrate stage ST1, for example, a magnet unit 88 having a permanent magnet group consisting of a plurality of sets of N-pole magnets and S-pole magnets arranged alternately at predetermined intervals along the X-axis direction. Is provided. The magnet unit 88 and the X-axis linear guide 89 constitute a moving magnet type X-axis linear motor 81 that drives the substrate stage ST1 in the X-axis direction. Similarly, the X-axis linear guide 87 is provided in an inserted state in an opening formed in the measurement stage ST2. A magnet unit 86 is provided in the opening of the measurement stage ST2. The magnet unit 86 and the X-axis linear guide 87 constitute a moving magnet type X-axis linear motor 80 that drives the measurement stage ST2 in the X-axis direction.

  Then, by slightly varying the thrust generated by each of the pair of Y-axis linear motors 84 and 85 (or 82 and 83), the substrate stage ST1 (or measurement stage ST2) can be controlled in the θZ direction. In the figure, each of the substrate stage ST1 and the measurement stage ST2 is shown as a single stage. However, in reality, an XY stage driven by a Y-axis linear motor and a Z on the XY stage are provided. It is mounted via a leveling drive mechanism (for example, a voice coil motor) and includes a Z tilt stage that is relatively finely driven in the Z-axis direction and in the θX and θY directions with respect to the XY stage. A substrate holder PH (see FIG. 1) that holds the substrate P is supported by the Z tilt stage.

  Hereinafter, a parallel processing operation using the substrate stage ST1 and the measurement stage ST2 will be described with reference to FIGS.

  As shown in FIG. 2, when performing immersion exposure of the substrate P, the control device CONT causes the measurement stage ST2 to stand by at a predetermined standby position where it does not collide with the substrate stage ST1. Then, the control device CONT performs step-and-scan immersion exposure on the substrate P supported by the substrate stage ST1 in a state where the substrate stage ST1 and the measurement stage ST2 are separated from each other. When performing immersion exposure of the substrate P, the controller CONT uses the immersion mechanism 1 to form an immersion region LR of the liquid LQ on the substrate stage ST1.

  The control apparatus CONT moves the measurement stage ST2 using the drive mechanism SD after completing the immersion exposure for the predetermined number of substrates P in the substrate stage ST1, and moves the measurement stage ST2 to the substrate stage ST1 as shown in FIG. On the other hand, the measurement stage ST2 is brought into contact (or close proximity).

  Next, the control apparatus CONT uses the drive mechanism SD to move the substrate stage ST1 and the measurement stage ST2 in the −Y direction while maintaining the relative positional relationship between the substrate stage ST1 and the measurement stage ST2 in the Y-axis direction. Move at the same time. That is, the control device CONT moves together in the −Y direction within a predetermined region including a position directly below the projection optical system PL in a state where the substrate stage ST1 and the measurement stage ST2 are in contact (or close to each other).

  The control device CONT moves the substrate stage ST1 and the measurement stage ST2 together, so that the liquid LQ held between the first optical element LS1 of the projection optical system PL and the substrate P is transferred to the substrate stage ST1. It moves from the upper surface F1 to the upper surface F2 of the measurement stage ST2. The liquid immersion region LR of the liquid LQ formed between the first optical element LS1 of the projection optical system PL and the substrate P is moved along with the movement of the substrate stage ST1 and the measurement stage ST2 in the −Y direction. The surface moves in the order of the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the measurement stage ST2. Then, while the liquid immersion area LR of the liquid LQ is moving on the upper surface F2 of the measurement stage ST2 from the upper surface F1 of the substrate stage ST1, as shown in FIG. 3B, the upper surface F1 of the substrate stage ST1 and the measurement stage It arrange | positions simultaneously so that the upper surface F2 of ST2 may be straddled.

  When the substrate stage ST1 and the measurement stage ST2 further move together in the −Y direction by a predetermined distance from the state of FIG. 3B, as shown in FIG. 4A, the first optical element LS1 of the projection optical system PL and The liquid LQ is held between the measurement stage ST2. That is, the liquid immersion area LR of the liquid LQ is disposed on the upper surface F2 of the measurement stage ST2.

  Next, the control device CONT uses the drive mechanism SD to move the substrate stage ST1 to a predetermined substrate replacement position and replace the substrate P. In parallel with this, a predetermined measurement process using the measurement stage ST2 is performed. Perform as necessary. As this measurement, for example, baseline measurement of the alignment system ALG performed after replacement on the mask stage MST can be cited as an example. Specifically, in the control apparatus CONT, the above-described mask alignment system RAa, a pair of first reference marks on the reference mark plate FM provided on the measurement stage ST2 and the corresponding mask alignment marks on the mask M are represented. Detection is performed simultaneously using RAb, and the positional relationship between the first reference mark and the corresponding mask alignment mark is detected. At the same time, the control device CONT detects the second reference mark on the reference mark plate FM by the alignment system ALG, thereby detecting the positional relationship between the detection reference position of the alignment system ALG and the second reference mark. Then, the control device CONT includes a positional relationship between the first reference mark and the corresponding mask alignment mark, a positional relationship between the detection reference position of the alignment system ALG and the second reference mark, a known first reference mark, Based on the positional relationship with the second reference mark, the distance between the projection center of the mask pattern by the projection optical system PL and the detection reference position of the alignment system ALG, that is, the baseline of the alignment system ALG is obtained. FIG. 4B shows the state at this time.

  Then, after the processing on both the stages ST1 and ST2 is completed, the control apparatus CONT, for example, brings the measurement stage ST2 and the substrate stage ST1 into contact (or close proximity) and maintains the relative positional relationship therebetween. , Move in the XY plane, and perform an alignment process on the replaced substrate P. Here, a plurality of shot areas are provided on the substrate P, and an alignment mark is provided along with each of the plurality of shot areas. The control device CONT detects the alignment mark on the replaced substrate P by the alignment system ALG, and calculates the position coordinates of the plurality of shot areas provided on the substrate P with respect to the detection reference position of the alignment system ALG.

  Thereafter, contrary to the previous case, the control device CONT moves both stages ST1 and ST2 together in the + Y direction while maintaining the relative positional relationship between the substrate stage ST1 and the measurement stage ST2 in the Y-axis direction. After moving the substrate stage ST1 (substrate P) below the projection optical system PL, the measurement stage ST2 is retracted to a predetermined position. Thereby, the immersion region LR is arranged on the upper surface F1 of the substrate stage ST1. Even when the immersion region LR of the liquid LQ is moved from the upper surface F2 of the measurement stage ST2 to the upper surface F1 of the substrate stage ST1, the immersion region LR straddles the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the measurement stage ST2. Are arranged at the same time.

  Thereafter, the control device CONT performs a step-and-scan immersion exposure operation on the substrate P, and sequentially transfers the pattern of the mask M to each of a plurality of shot regions on the substrate P. The movement of the substrate stage ST1 to the acceleration start position for exposure of each shot area on the substrate P is performed immediately before the position coordinates of the plurality of shot areas on the substrate P obtained as a result of the above-described substrate alignment. This is based on the measured baseline.

  Note that the measurement operation is not limited to the above-described baseline measurement, and the measurement stage ST2 is used to perform illuminance measurement, illuminance unevenness measurement, aerial image measurement, and the like, for example, in parallel with substrate replacement, and based on the measurement results. Thus, for example, a calibration process of the projection optical system PL may be performed, which may be reflected in subsequent exposure of the substrate P.

  In the present embodiment, the liquid LQ immersion region LR is moved between the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the measurement stage ST2 without going through steps such as total recovery of the liquid LQ and resupply. Therefore, the time from the end of the exposure operation at the substrate stage ST1 to the start of the measurement operation at the measurement stage ST2 and the time from the end of the measurement at the measurement stage ST2 to the disclosure of the exposure operation at the substrate stage ST1 can be shortened. Improvements can be made. Further, since the liquid LQ always exists on the image plane side of the projection optical system PL, it is possible to effectively prevent the adhesion mark (so-called watermark) of the liquid LQ from being generated.

  As described above, the liquid immersion area LR of the liquid LQ is moved from the upper surface F1 of the substrate stage ST1 to the upper surface F2 of the measurement stage ST2, or is moved from the upper surface F2 of the measurement stage ST2 to the upper surface F1 of the substrate stage ST1. In other words, the immersion region LR is in a state of being simultaneously disposed so as to straddle the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the measurement stage ST2.

  FIG. 5 is a side view showing a state where the liquid immersion region LR moves from the upper surface F1 of the substrate stage ST1 to the upper surface F2 of the measurement stage ST2. As shown in FIG. 5A, when the immersion region LR is moved from the upper surface F1 of the substrate stage ST1 to the upper surface F2 of the measurement stage ST2, the control device CONT uses the drive mechanism SD to detect the upper surface of the substrate stage ST1. F1 is set higher in the Z-axis direction than the upper surface F2 of the measurement stage ST2. Then, in a state where the relative positional relationship in the Z-axis direction between the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the measurement stage ST2 is maintained, the control device CONT further moves the substrate stage ST1 and the measurement stage ST2 to -Y. Move together in the direction. By doing so, a part of the liquid LQ separated from the liquid immersion region LR is dropped on the upper surface F1 of the substrate stage ST1 and the side surface of the overhang portion H1, or the upper surface F2 of the measurement stage ST2 and the side surface of the overhang portion H2. The liquid immersion region LR is prevented while remaining in the form of (water droplets) or preventing inconvenience such as leakage of the liquid LQ from the gap G between the upper surface F1 of the substrate stage ST1 and the upper surface F2 of the measurement stage ST2. It can move to the upper surface F2 of the measurement stage ST2. By preventing the liquid LQ from remaining or leaking out, the environment in which the exposure apparatus EX is placed changes, the temperature of each member constituting the exposure apparatus due to the heat of vaporization of the remaining liquid LQ, or the liquid on the stage It is possible to prevent the inconvenience of forming (droplet) adhesion marks (so-called watermarks), and to perform exposure processing and measurement processing with high accuracy. FIG. 5B shows a state where the movement from the upper surface F1 of the substrate stage ST1 to the upper surface F2 of the measurement stage ST2 is completed and the liquid immersion region LR is arranged on the upper surface F2 of the measurement stage ST2. Has been.

  Similarly, when moving the immersion region LR from the upper surface F2 of the measurement stage ST2 to the upper surface F1 of the substrate stage ST1, the control device CONT uses the drive mechanism SD to change the upper surface F2 of the measurement stage ST2 to the upper surface of the substrate stage ST1. By making it higher in the Z-axis direction than F1, it is possible to prevent the occurrence of inconvenience that a part of the liquid LQ separated from the liquid immersion region LR remains as a droplet (water droplet) or the liquid LQ leaks.

<Second Embodiment>
FIG. 6 is a view showing an exposure apparatus EX ′ according to the second embodiment. The exposure apparatus EX ′ shown in FIG. 6 moves while holding the substrate P as disclosed in, for example, JP-A-10-163099, JP-A-10-214783, JP2000-505958A, and the like. This is a so-called twin stage type exposure apparatus having two possible substrate stages ST1 ′ and ST2 ′. Also in the exposure apparatus EX ′ shown in FIG. 6, the immersion region LR can be moved between the upper surface F1 ′ of the first substrate stage ST1 ′ and the upper surface F2 ′ of the second substrate stage ST2 ′. As in the above-described embodiment, when the immersion region LR is moved from the upper surface of one stage to the upper surface of the other stage of the first substrate stage ST1 ′ and the second substrate stage ST2 ′, one stage By making the upper surface of the liquid crystal higher than the upper surface of the other stage, it is possible to prevent the liquid LQ from remaining or leaking.

  As described above, the liquid LQ in the present embodiment is composed of pure water. Pure water has an advantage that it can be easily obtained in large quantities at a semiconductor manufacturing factory or the like, and has no adverse effect on the photoresist, optical element (lens), etc. on the substrate P. In addition, pure water has no adverse effects on the environment, and since the impurity content is extremely low, it can be expected to clean the surface of the substrate P and the surface of the optical element provided on the front end surface of the projection optical system PL. . When the purity of pure water supplied from a factory or the like is low, the exposure apparatus may have an ultrapure water production device.

  The refractive index n of pure water (water) with respect to the exposure light EL having a wavelength of about 193 nm is said to be approximately 1.44. When ArF excimer laser light (wavelength 193 nm) is used as the light source of the exposure light EL, On the substrate P, the wavelength is shortened to 1 / n, that is, about 134 nm, and a high resolution can be obtained. Furthermore, since the depth of focus is enlarged by about n times, that is, about 1.44 times compared with that in the air, the projection optical system PL can be used when it is sufficient to ensure the same depth of focus as that in the air. The numerical aperture can be further increased, and the resolution is improved in this respect as well.

The liquid LQ of the present embodiment is water, but may be a liquid other than water. For example, when the light source of the exposure light EL is an F ₂ laser, the F ₂ laser light does not pass through water. The liquid LQ may be, for example, a fluorinated fluid such as perfluorinated polyether (PFPE) or fluorinated oil that can transmit F ₂ laser light. In this case, the lyophilic treatment is performed by forming a thin film with a substance having a molecular structure having a small polarity including fluorine, for example, at a portion in contact with the liquid LQ. In addition, as the liquid LQ, the liquid LQ is transmissive to the exposure light EL, has a refractive index as high as possible, and is stable with respect to the photoresist applied to the projection optical system PL and the surface of the substrate P (for example, Cedar). Oil) can also be used. Also in this case, the surface treatment is performed according to the polarity of the liquid LQ to be used.

  The substrate P in each of the above embodiments is not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus. (Synthetic quartz, silicon wafer) or the like is applied.

  As the exposure apparatus EX, in addition to the step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask M by moving the mask M and the substrate P synchronously, the mask M and the substrate P Can be applied to a step-and-repeat type projection exposure apparatus (stepper) in which the pattern of the mask M is collectively exposed while the substrate P is stationary and the substrate P is sequentially moved stepwise.

  Further, as the exposure apparatus EX, a reduced image of the first pattern is projected with the first pattern and the substrate P being substantially stationary (for example, a refraction type projection optical system that does not include a reflecting element at 1/8 reduction magnification). The present invention can also be applied to an exposure apparatus that performs batch exposure on the substrate P using the above. In this case, after that, with the second pattern and the substrate P substantially stationary, a reduced image of the second pattern is collectively exposed onto the substrate P by partially overlapping the first pattern using the projection optical system. It can also be applied to a stitch type batch exposure apparatus. Further, the stitch type exposure apparatus can be applied to a step-and-stitch type exposure apparatus in which at least two patterns are partially transferred on the substrate P, and the substrate P is sequentially moved.

  In the above-described embodiment, an exposure apparatus that locally fills the liquid between the projection optical system PL and the substrate P is employed. However, the present invention is disclosed in Japanese Patent Laid-Open No. 6-124873. It is also applicable to an immersion exposure apparatus that moves a stage holding a substrate to be exposed in a liquid tank.

  The type of the exposure apparatus EX is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on the substrate P, but an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD). ) Or an exposure apparatus for manufacturing reticles or masks.

  The exposure apparatus EX according to the embodiment of the present application is manufactured by assembling various subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Is done. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As shown in FIG. 7, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate as a base material of the device. Manufacturing step 203, exposure processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus EX of the above-described embodiment, device assembly step (including dicing process, bonding process, packaging process) 205, inspection step 206, etc. It is manufactured after.

It is a schematic block diagram which shows the exposure apparatus which concerns on 1st Embodiment. It is the top view which looked at the substrate stage and the measurement stage from the upper part. It is a figure for demonstrating operation | movement of a substrate stage and a measurement stage. It is a figure for demonstrating operation | movement of a substrate stage and a measurement stage. It is a figure for demonstrating the state which is moving the liquid immersion area | region. It is a schematic block diagram which shows the exposure apparatus which concerns on 2nd Embodiment. It is a flowchart figure which shows an example of the manufacturing process of a microdevice.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Immersion mechanism, CONT ... Control apparatus, EX ... Exposure apparatus, F1 ... Upper surface, F2 ... Upper surface, LQ ... Liquid, LR ... Immersion area, P ... Substrate, PL ... Projection optical system, SD ... Drive mechanism, ST1 ... Substrate stage (first stage), ST2 ... Measurement stage (second stage)

Claims (4)

In an exposure apparatus that exposes a substrate via a projection optical system,
A first stage and a second stage movable independently of each other in a two-dimensional plane substantially parallel to the image plane on the image plane side of the projection optical system;
A drive mechanism that moves the first stage and the second stage together within a predetermined region including a position directly below the projection optical system in a state in which the first stage and the second stage are close to or in contact with each other; ,
A liquid immersion mechanism for forming a liquid immersion area on the upper surface of at least one of the first stage and the second stage;
By moving the first stage and the second stage together, the liquid immersion area is moved to the first stage while the liquid is held between the projection optical system and the upper surface of the at least one stage. Between the upper surface of the second stage and the upper surface of the second stage,
Of the first stage and the second stage, when the immersion area is moved from the upper surface of one stage to the upper surface of the other stage, the upper surface of the one stage is made higher than the upper surface of the other stage. An exposure apparatus characterized by the above.   2. The exposure apparatus according to claim 1, wherein one of the first stage and the second stage moves while holding the substrate, and the other stage carries and moves a measuring instrument that performs measurement related to exposure processing.   The exposure apparatus according to claim 1, wherein each of the first stage and the second stage moves while holding a substrate.   The device manufacturing method using the exposure apparatus as described in any one of Claims 1-3.

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