JP2005064373A - Exposure equipment - Google Patents

Abstract

An object of the present invention is to increase the degree of freedom of arrangement in a factory while maintaining the maintainability of an exposure apparatus.
In an exposure apparatus 10, an illumination unit ILU is erected on the −X side and a wafer loader WL is installed on the −Y side with respect to a wafer stage base 12 having a substantially rectangular plate shape. In addition, a side unit along the longitudinal direction on the + Y side of the wafer stage base 12 and a side unit along the short side on the + X side are provided with a fixed unit for maintenance of the wafer stages WST1 and WST2 from here. I try not to. In this way, maintainability with respect to both stages WST1, WST2 can be maintained, and it is not necessary to dispose a fixed unit in at least one of the side regions on both sides in the longitudinal direction of wafer stage base 12. The whole is not elongated in a predetermined direction in the horizontal plane.
[Selection] Figure 2

Description

  The present invention relates to an exposure apparatus, and more particularly, to an exposure apparatus that transfers a pattern formed on a mask onto a photosensitive object via a projection optical system using an energy beam.

  Conventionally, in a lithography process for manufacturing a semiconductor element, a liquid crystal display element or the like, a resist or the like is applied to a pattern formed on a mask or a reticle (hereinafter collectively referred to as “reticle”) via a projection optical system. Projection exposure apparatus for transferring onto a substrate such as a wafer or a glass plate (hereinafter collectively referred to as “wafer”), for example, a step-and-repeat reduction projection exposure apparatus (so-called stepper), and improvements to this stepper Sequentially moving projection exposure apparatuses such as step-and-scan type scanning exposure apparatuses (so-called scanning steppers) are used relatively frequently.

  Recently, in such an exposure apparatus, in order to improve the throughput of how many wafers can be processed within a certain time, that is, the throughput, the wafer exchange operation and the alignment operation are simultaneously performed in parallel with the exposure operation. In some cases, a stage apparatus having a plurality of wafer stages that hold and move the wafer is provided.

  As an example of such an exposure apparatus, an exposure apparatus 10 'having a stage apparatus having two wafer stages is schematically shown in FIG. FIG. 6 is a top view of the exposure apparatus 10 ′, and unnecessary components are not shown. As shown in FIG. 6, the exposure apparatus 10 ′ includes a stage apparatus 30. In stage device 30, wafer stage base 12 having a substantially rectangular plate shape when viewed from the + Z side is laid, and wafer stage WST1 for holding wafers W1 and W2 on the XY plane of wafer stage base 12 is provided. , WST2 are configured to be independently movable by a stage drive system including an actuator such as a linear motor or a planar motor (not shown).

  In addition to the stage apparatus 30, the exposure apparatus 10 'includes a projection optical system PL, an illumination unit ILU, alignment systems ALG1 and ALG2, wafer loaders WL1 and WL2, and the like. In FIG. 6, the projection optical system PL is installed substantially above the center of the wafer stage base 12 (+ Z side). The illumination unit ILU is erected on the −Y side of the wafer stage base 12, and the upper part (+ Z side) projects to the + Y side up to above the projection optical system PL. In the illumination unit ILU, illumination light emitted from a light source (not shown) provided near the floor and traveling in the + Z direction by the internal optical system is folded to the + Y side by the folding mirror, and then to the −Z side, and the reticle. (Not shown), the light is emitted toward the projection optical system PL. The alignment systems ALG1 and ALG2 are arranged on the wafer stage base 12 so as to sandwich the projection optical system PL in the X-axis direction. Wafer loader WL1 is installed on the −X side of wafer stage base 12, and performs loading and unloading operations of wafer W1 on wafer stage WST1. Wafer loader WL2 is installed on the + X side of wafer stage base 12, and performs loading and unloading operations of wafer W2 on wafer stage WST2.

  In exposure apparatus 10 ′ configured as described above, one of wafer stages WST1 and WST2 moves below projection optical system PL and is performing exposure of the wafer held on that stage. In the other stage, wafer exchange and alignment using an alignment system (any of alignment systems ALG1 and ALG2) are performed. In this way, when the exposure on one stage is completed, the other stage can be quickly moved below the projection optical system PL to perform exposure, thereby improving the throughput.

  By the way, in such an exposure apparatus 10 ′, it is necessary to periodically perform operations such as maintenance and adjustment of both wafer stages WST 1 and WST 2 in order to prevent a decrease in throughput and exposure accuracy. In the configuration (unit arrangement) of FIG. 6, operations such as maintenance and adjustment of both wafer stages WST1 and WST2 are performed along the longitudinal direction (X-axis direction) of wafer stage base 12 having good accessibility to both stages WST1 and WST2. Further, since it can be carried out from the side surface portion on the + Y side, it can be said that such an arrangement is desirable from the viewpoint of maintenance and adjustment efficiency of both stages WST1 and WST2.

  However, in the configuration of FIG. 6 (unit arrangement), the length of the apparatus becomes longer in the X-axis direction. Therefore, when the exposure apparatus 10 ′ is arranged in the factory, the arrangement space is restricted. There is a possibility that the degree of freedom of the arrangement of the exposure apparatus 10 'in the inside may be hindered.

  The present invention has been made under such circumstances, and an object of the present invention is to provide an exposure apparatus in which the maintainability of the stage is maintained and the degree of freedom of arrangement in the factory is not limited.

  The invention described in claim 1 is an exposure apparatus for transferring a pattern formed on a mask (R) onto a photosensitive object (W1, W2) via a projection optical system (PL) by an energy beam. A plurality of stages (WST1, WST2) for holding the photosensitive objects (W1, W2); a stage surface plate (12) having a substantially rectangular shape in plan view on which support surfaces of the plurality of stages are formed; Among the regions surrounding the four sides of the plate, at least a part of the specific region excluding the side region along one longitudinal direction of the stage surface plate and the one side region perpendicular to the longitudinal direction, An exposure apparatus (10) comprising: at least one fixed unit (ILU, WL, etc.) partially or entirely arranged.

  According to this, one side region along the longitudinal direction of the stage surface plate among the regions surrounding the four sides of the stage surface plate having a substantially rectangular shape in plan view in which the support surfaces of the plurality of stages are formed, and the A part or all of the fixed unit is arranged in at least a part of the specific region excluding the side region on one side in the short direction perpendicular to the longitudinal direction. Therefore, one side region along the longitudinal direction of the stage surface plate and one side region along the short side direction can be secured as a free space that can be used for maintenance, and the length of the stage surface plate There is no need to place a fixed unit in at least one of the side regions at both ends in the direction. Therefore, it is possible to prevent the apparatus from becoming elongated in a predetermined direction in the horizontal plane and hindering the degree of freedom of arrangement in the factory while maintaining maintainability for each stage.

  In this case, as in the exposure apparatus according to claim 2, the fixed unit includes an illumination unit that irradiates the mask with the energy beam, and a transport apparatus that carries the photosensitive object in and out of each stage. , At least one of a storage mechanism for storing the photosensitive object, a leg portion of a support that supports the projection optical system, and a device that performs at least one of application and development of a photosensitive agent on the photosensitive object. Can be.

  3. The exposure apparatus according to claim 1 or 2, wherein, as in the exposure apparatus according to claim 3, the fixed unit is a transport device that carries the photosensitive object in and out of the stages. The transfer device may be disposed in a side region along the other longitudinal direction of the stage surface plate.

  The exposure apparatus according to any one of claims 1 to 3, wherein, as in the exposure apparatus according to claim 4, a movable unit arranged in an area on one side of the short side of the stage surface plate. Can be further provided.

  In this case, as in the exposure apparatus according to the fifth aspect, the movable unit can be a control apparatus that controls the operation of the entire apparatus.

  In the exposure apparatus according to any one of claims 1 to 5, as in the exposure apparatus according to claim 6, the fixed unit is an illumination unit that irradiates the mask with the energy beam, At least a part of the illumination unit is disposed in a side region along the other lateral direction of the stage surface plate, and when transferring the pattern formed on the mask onto the photosensitive object, the mask and the It is possible to further include a driving device that synchronously moves the photosensitive object along the longitudinal direction of the stage surface plate.

  In this case, as in the exposure apparatus according to claim 7, the illumination unit includes a folding mirror that bends an optical path of the energy beam so as to guide the energy beam generated from the light source that generates the energy beam onto the mask. The folding direction of the energy beam and the synchronous movement direction when the mask and the photosensitive object are synchronously moved substantially coincide with each other on the reflecting surface of the folding mirror.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of an exposure apparatus 10 according to an embodiment.

  The exposure apparatus 10 includes an illumination unit ILU that illuminates a reticle R as a mask with pulsed ultraviolet light (energy beam) from a light source 2, a reticle stage RST that holds the reticle R, and illumination light (pulsed ultraviolet) emitted from the reticle R. Projection optical system PL that projects light) onto wafers W1 and W2 as photosensitive objects, and stage device 30 including wafer stages WST1 and WST2 for holding wafers W1 and W2, respectively. Further, the exposure apparatus 10 includes an illumination unit ILU, a reticle stage RST, a main body 36 that holds the projection optical system PL, and the like. The main body 36 holds the illumination unit ILU by a holding member (not shown in FIG. 1).

  The illumination unit ILU includes an illumination system housing 40 and a predetermined position in the illumination system housing 40 as disclosed in, for example, Japanese Patent Application Laid-Open No. 1-259533 (corresponding US Pat. No. 5,307,207). Variable dimmer, beam shaping optical system, optical integrator (such as fly-eye lens, internal reflection type integrator, or diffractive optical element), condensing optical system, vibrating mirror, illumination system aperture stop plate, relay A reticle stage RST using illumination light generated by a light source 2 and obtained via a beam matching unit (BMU). The illumination stage includes a lens system, a reticle blind, a main condenser lens, a mirror, and a lens system. A predetermined illumination area on the reticle R held above (a slit shape linearly extending in the Y-axis direction or Illuminating an illumination area) of the shape with a uniform illuminance distribution. Here, the rectangular slit-shaped illumination light IL applied to the reticle R is set to extend in the Y-axis direction (non-scanning direction) at the center of the circular projection field of the projection optical system PL in FIG. The width of the illumination light IL in the X-axis direction (scanning direction) is set to be substantially constant.

  The main body 36 has a plurality (four in this case) of support members 42A to 42D (in FIG. 1, only the support members 42A and 42D are illustrated on the floor F, and the support members 42C and 42D are illustrated. 2) and a lens barrel base plate 46 supported substantially horizontally via an anti-vibration unit 44 fixed to the upper portions of the support members 42A to 42D, and a support column 52 provided on the lens barrel base plate 46. And.

  The anti-vibration unit 44 includes, for example, an air mount and a voice coil motor, which are arranged in series (or in parallel) on the upper portions of the support members 42A to 42D and can adjust the internal pressure. The vibration isolation unit 44 is adapted to insulate micro vibrations from the floor surface F transmitted to the lens barrel surface plate 46 via the floor surface F and the support members 42A to 42D at the micro G level.

  The lens barrel surface plate 46 is made of a casting or the like, and has a circular opening in a plan view (viewed from above) at the center thereof, and the projection optical system PL has its optical axis direction in the Z-axis direction. Is inserted from above. A flange FLG integrated with the lens barrel is provided on the outer periphery of the lens barrel of the projection optical system PL, and the projection optical system PL is attached to the lens barrel base plate 46 via the flange FLG. ing.

  The support column 52 includes, for example, three legs 58 (the illustration of the legs 58 on the back side of the drawing is omitted) disposed on the upper surface of the lens barrel base plate 46 so as to surround the projection optical system PL, and these legs. And a reticle base surface plate 60 supported substantially horizontally by 58.

  The reticle stage RST is disposed on the reticle base surface plate 60 constituting the support column 52. Reticle stage RST is driven by a reticle stage drive system (not shown) including, for example, a linear motor, etc., and reticle R is linearly driven on reticle base surface plate 60 with a large stroke in the X-axis direction, and in the Y-axis direction and θz direction. With respect to the (rotational direction around the Z axis), it is possible to perform minute driving.

  The reticle stage RST is formed with a reflecting surface composed of a moving mirror or the like facing the X-axis direction and the Y-axis direction for reflecting the laser beam, and the position (rotation around the Z-axis) in the XY plane of the reticle stage RST. Is detected with a resolution of about 0.5 to 1 nm by a reticle laser interferometer 64 that is fixed to the reticle base surface plate 60 and irradiates the above-mentioned reflecting surface with laser light. Here, actually, a reticle X interferometer having a length measuring axis along the X axis direction and a reticle Y interferometer having a length measuring axis along the Y axis direction are provided. Is typically shown as a reticle laser interferometer 64. At least one of the reticle Y interferometer and the reticle X interferometer, for example, the reticle X interferometer, is a two-axis interferometer having two measurement axes, and the X position of the reticle stage RST is based on the measurement value of the reticle X interferometer. In addition, the rotation amount (yawing amount) in the θz direction (rotation direction around the Z axis) can also be measured.

  Position information (or velocity information) of reticle stage RST (that is, reticle R) measured by reticle laser interferometer 64 is sent to a control device (not shown). The control device basically uses a reticle stage drive system (not shown) so that the position information (or speed information) output from the reticle laser interferometer 64 matches the command value (target position, target speed). The position (or speed) of the stage RST is controlled.

  Here, as the projection optical system PL, both the object plane (reticle R) side and the image plane (wafer W1 (or W2)) side are telecentric and have a circular projection field, and quartz or fluorite is used as an optical glass material. A refracting optical system having a reduction ratio of 1/4, 1/5, or 1/6 consisting of only the refractive optical element (lens element) is used. For this reason, when the reticle R is irradiated with pulsed ultraviolet light, the imaging light beam from the portion illuminated by the pulsed ultraviolet light in the circuit pattern area on the reticle R enters the projection optical system PL, and the circuit pattern The partial inverted image is formed in the center of the circular field on the image plane side of the projection optical system PL in a slit shape or a rectangular shape (polygonal shape) for each pulse irradiation of pulsed ultraviolet light. As a result, the partially inverted image of the projected circuit pattern is formed on the resist layer on the surface of one shot area of the plurality of shot areas on the wafer W1 (or W2) arranged on the imaging plane of the projection optical system PL. Reduced transfer.

  On one side and the other side of the projection optical system PL in the X-axis direction, a pair of alignment systems ALG1 and ALG2 as off-axis type mark detection systems having the same function are provided on the lens barrel surface plate. 46 are respectively located at the same distance from the optical axis of projection optical system PL (substantially coincident with the projection center of the reticle pattern image).

  As the alignment systems ALG and ALG2, in the present embodiment, an FIA (field image alignment) type alignment sensor, which is a kind of image processing type imaging type alignment sensor, is used. These alignment systems ALG1 and ALG2 include a light source (for example, a halogen lamp) and an imaging optical system, an index plate on which an index mark serving as a detection reference is formed, an image sensor (CCD), and the like. In these alignment systems ALG1 and ALG2, a mark to be detected is illuminated by broadband light from a light source, and reflected light from the vicinity of the mark is received by a CCD via an imaging optical system and an index. At this time, the mark image is formed on the image pickup surface of the CCD together with the index image. Then, by performing predetermined signal processing on the image signal (imaging signal) from the CCD, the position of the mark with respect to the center of the index mark that is the detection reference point is measured.

  In addition to the FIA system, the target mark is irradiated with coherent detection light to detect scattered light or diffracted light generated from the target mark, or two diffracted lights (for example, of the same order) generated from the target mark. Of course, it is possible to use an alignment sensor that detects the interference by interfering with each other singly or in an appropriate combination.

  In the present embodiment, alignment system ALG1 is used for measuring the position of an alignment mark on a wafer held on wafer stage WST1 or a reference mark formed on a reference mark plate (not shown). Alignment system ALG2 is used for measuring the position of alignment marks on a wafer held on wafer stage WST2 and a reference mark formed on a reference mark plate (not shown).

  The stage device 30 has the upper surface of the wafer stage base 12 as a support surface, and is levitated and supported above it via an air bearing (not shown). Are two wafer stages WST1 and WST2 that can be moved two-dimensionally independently in the Y-axis direction (the direction orthogonal to the paper surface in FIG. 1), and linears (not shown) that drive these wafer stages WST1 and WST2 in the XY plane, respectively. A stage drive system including an actuator such as a motor or a planar motor is provided. For example, the configuration of a stage drive system including a linear motor is described in, for example, Japanese Patent Application Laid-Open No. 10-163100, and detailed description thereof is omitted here.

  The one wafer stage WST1 is composed of a plate-like member, and a wafer holder (not shown) is provided on the upper surface thereof so that the wafer W1 is sucked and held on the wafer holder by a vacuum suction force of a vacuum pump or the like of the wafer holder. It has become.

  Wafer stage WST1 has a reflecting surface such as a moving mirror perpendicular to the X axis extending at one end (−X side end) in the X axis direction, and at one end (+ Y side end) in the Y axis direction. A reflecting surface such as a movable mirror orthogonal to the Y axis is extended. As shown in FIG. 2, interferometer beams (measurement beams) from a plurality of interferometers, which will be described later, are projected onto the respective reflecting surfaces, and the reflected light is received by the respective interferometers. Displacement from the reference position of the reflecting surface (generally, a fixed mirror is disposed on the side surface of the projection optical system PL or the side surface of the alignment system ALG1 and used as the reference surface) is measured, and thereby, 2 of the wafer stage WST1 is measured. The dimension position is measured.

  The configuration of the other wafer stage WST2 is the same as that of wafer stage WST1 described above. Wafer stage WST2 has a reflecting surface such as a movable mirror orthogonal to the X axis extending at the + X side end.

  Next, the interferometer system for measuring the two-dimensional position of each wafer stage will be described with reference to FIG.

  As shown in FIG. 2, the reflection surface orthogonal to the X-axis direction on wafer stage WST1 has X-axis interference along the X-axis passing through the optical axis of projection optical system PL and the optical axis of alignment system ALG1. The interferometer beam indicated by the measurement axis BI1X from the meter 116 is irradiated. Similarly, the reflection surface orthogonal to the X-axis direction on wafer stage WST2 is measured by X-axis interferometer 118 along the X-axis passing through the optical axis of projection optical system PL and the optical axis of alignment system ALG2. The interferometer beam indicated by the long axis BI2X is irradiated. The X-axis interferometers 116 and 118 receive the reflected light from the respective reflecting surfaces, thereby measuring the relative displacement of each reflecting surface from the reference position and measuring the positions of the wafer stages WST1 and WST2 in the X-axis direction. It is supposed to be. Here, the X-axis interferometers 116 and 118 are three-axis interferometers each having three optical axes. In addition to the measurement in the X-axis direction of the wafer stages WST1 and WST2, the pitching (rotation around the Y-axis (θy rotation) is performed. )) And yawing (rotation in the θz direction) can be measured. The output value of each optical axis can be measured independently.

  The interferometer beams of the measurement axis BI1X and the measurement axis BI2X always come into contact with the reflecting surfaces orthogonal to the X-axis direction of both stages WST1 and WST2 over the entire movement range of the wafer stages WST1 and WST2. In the X-axis direction, the X position of wafer stages WST1 and WST2 regardless of whether both stages WST1 and WST2 are positioned under projection optical system PL or under alignment systems ALG1 and ALG2. Are managed based on the measurement values of the measurement axis BI1X and the measurement axis BI2X.

  In this embodiment, the Y-axis interferometer 146 having a measurement axis BI2Y perpendicularly intersecting the measurement axes BI1X and BI2X with the optical axis of the projection optical system PL, and the measurement with the optical axes of the alignment systems ALG1 and ALG2. Y-axis interferometers 144 and 148 having length measuring axes BI1Y and BI3Y respectively perpendicular to the axes BI1X and BI2X are provided.

  In the present embodiment, the Y-axis interferometer having a measurement axis BI2Y that passes through the optical axis of the projection optical system PL is used for measuring the Y-direction position of the wafer stages WST1 and WST2 when it is located in the vicinity of the projection optical system PL. The Y-axis interferometer 144 having the measurement axis BI1Y passing through the optical axis of the alignment system ALG1 is used to measure the Y-direction position of the wafer stage WST1 when the measurement value 146 is used and is positioned in the vicinity of the alignment system ALG1. Is used, and Y-direction position measurement of wafer stage WST2 when it is positioned in the vicinity of alignment system ALG2 uses Y-axis interferometer 148 having a measurement axis BI3Y that passes through the optical axis of alignment system ALG2. Measurement values are used.

  Thus, in this embodiment, the wafer interferometer that manages the XY two-dimensional coordinate positions of wafer stages WST1 and WST2 by a total of five interferometers, that is, X-axis interferometers 116 and 118 and Y-axis interferometers 144, 146, and 148. The system is configured.

  Since the distance between the measurement beams of Y-axis interferometers 144 to 148 is larger than the length in the longitudinal direction of the reflecting surface perpendicular to the Y-axis direction of wafer stages WST1 and WST2, depending on the situation, the distance between Y-axis interferometers The measurement axis is deviated from the reflection surfaces of wafer stages WST1 and WST2. That is, when moving from the alignment position (position just below alignment systems ALG1 and ALG2) to the exposure position (position just below projection optical system PL) or from the exposure position to the wafer exchange position, the Y-axis direction When the interferometer beam does not hit the movable mirrors of wafer stages WST1 and WST2, a state occurs in which the interferometer used for stage position control must be switched. In light of this point, exposure apparatus 10 is provided with a linear encoder (not shown) that measures the positions of wafer stages WST1, WST2 in the Y-axis direction.

  That is, in this embodiment, the control device (not shown) moves the X-axis interferometer when the wafer stages WST1 and WST2 move from the alignment position to the exposure position or from the exposure position to the wafer exchange position. The movement of the X and Y positions of wafer stages WST1 and WST2 is controlled on the basis of the Y position information of wafer stages WST1 and WST2 measured by, and the X position information of wafer stages WST1 and WST2 measured by a linear encoder. .

  Of course, in the control apparatus, when the interferometer beam from the Y-axis interferometer again hits the movable mirror of the wafer stages WST1, WST2, the Y-axis interferometer of the measuring axis that has not been used for the control until then is reset ( Thereafter, the movement of wafer stages WST1 and WST2 is controlled based only on the measurement values of the X-axis interferometer and Y-axis interferometer constituting the interferometer system.

  The Y-axis interferometers 144, 146, and 148 are two-axis interferometers each having two optical axes. In addition to the measurement of the wafer stages WST1 and WST2 in the Y-axis direction, rolling (rotation around the X axis ( θx rotation)) can be measured. In addition, the output value of each optical axis can be measured independently.

  The measurement value of each interferometer constituting the interferometer system configured as described above is sent to a control device (not shown). In the control device, wafer stages WST1 and WST2 are controlled via the stage drive system (not shown) based on the output values of the interferometers. In other words, in this embodiment, wafer stages WST1 and WST2 are driven in the XY two-dimensional direction independently of each other and without mechanical interference.

  Further, in this embodiment, although not shown, a reticle mark on the reticle R and a reference mark plate (not shown) on the wafer stages WST1 and WST2 are provided above the reticle R via the projection optical system PL. There is provided a TTR (Through The Reticle) type reticle alignment microscope using an exposure wavelength for simultaneously observing the mark. Detection signals of these reticle alignment systems are supplied to a control device (not shown) via an alignment control device (not shown). Note that the configuration of the reticle alignment system is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-176468, and the detailed description thereof is omitted here.

  Although not shown, each of the projection optical system PL and alignment systems ALG1 and ALG2 has an autofocus / autoleveling measurement mechanism (hereinafter referred to as “AF / AL system”) for examining the in-focus position. Are provided. As described above, the configuration of the exposure apparatus in which the AF / AL system is provided in each of the projection optical system PL and the pair of alignment systems ALG1 and ALG2 is disclosed in detail in, for example, Japanese Patent Application Laid-Open No. 10-214783, and is publicly known. Therefore, further explanation is omitted here.

  As can be seen from FIG. 2, a wafer loader WL is provided in an area on the −Y side of the stage apparatus 30 of the exposure apparatus 10, that is, one side area along the longitudinal direction (X-axis direction) of the wafer stage base 12. ing. The wafer loader WL includes a chamber and a horizontal articulated robot (not shown) accommodated in the chamber. This robot can be driven in the X-axis direction along a guide laid in the chamber with the X-axis direction as the longitudinal direction, and loads and unloads the wafers W1, W2 with respect to both wafer stages WST1, WST2. It is possible.

  In the exposure apparatus 10 of the present embodiment configured as described above, while the wafer stage WST1 is performing an exposure operation immediately below the projection optical system PL, the wafer exchange operation and the alignment system ALG2 directly below the wafer stage WST2. The wafer alignment operation is performed. Similarly, while wafer stage WST2 is performing an exposure operation immediately below projection optical system PL, wafer exchange operation and wafer alignment operation using alignment system ALG1 are performed on wafer stage WST1 side. In exposure apparatus 10 of the present embodiment, throughput is improved by performing parallel processing operations on wafer stages WST1 and WST2 in this way.

  In the wafer exchange, an exposed wafer placed on wafer stage WST1 (or wafer stage WST2) is unloaded and a new wafer is loaded via a horizontal articulated robot in wafer loader WL. In this case, the exchange of the wafer on wafer stage WST1 is performed in a state where wafer stage WST1 is positioned in the vicinity of alignment system ALG1, and the replacement of the wafer on wafer stage WST2 is positioned in the vicinity of alignment system ALG2. It is done in the state.

  In the wafer alignment operation, wafer alignment such as an EGA (Enhanced Global Alignment) method disclosed in, for example, Japanese Patent Application Laid-Open No. 61-44429 is performed using the alignment system ALG1 or ALG2. Then, after such an alignment, the inter-shot stepping operation for moving wafer stage WST1 (or wafer stage WST2) to the acceleration start position for exposure of each shot area on wafer W1 (or wafer W2), A step-and-scan type exposure operation is performed in which the exposure operation for transferring the pattern of the reticle R to the shot area to be exposed is repeated by the scanning exposure. Since this exposure operation is performed in the same manner as a normal scanning stepper, detailed description thereof is omitted.

  In the above exposure operation, the control device drives the Y-axis linear motor (not shown) while driving the wafer stage WST1 (or WST2) in the X-axis direction (scan direction) through an X-axis linear motor (not shown). ) To finely drive wafer stage WST1 (or WST2).

  In the present embodiment, the scanning direction of wafer stages WST1 and WST2 is set to the X-axis direction as described above. This is due to the following reason.

  That is, in the present embodiment, as shown in FIG. 3, a folding mirror M provided in the illumination unit ILU for folding the optical path of the illumination light IL generated from the light source 2 and guiding the illumination light onto the reticle R. In consideration of downsizing in the height (Z-axis) direction and the effect of averaging uneven illumination in the illumination area on the reticle R, when the scan direction is the X-axis direction, a part of the illumination unit ILU This is because it is desirable that the illumination stage IL be arranged on the −X side (or + X side) of the wafer stage base 12 so that the bending direction of the illumination light IL substantially coincides with the scanning direction on the reflection surface of the bending mirror M.

  In the exposure apparatus 10 of the present embodiment, as described above, the wafer loader WL is arranged in the side region along the longitudinal direction of the wafer stage base 12 on the −Y side with respect to the wafer stage base 12. In this way, the shape of the installation space when the exposure apparatus 10 is projected from directly above can be brought close to, for example, a square shape. In this way, the shape of the installation space is not limited to a rectangular shape that is long and thin in the horizontal plane direction, so that the degree of freedom of arrangement of the exposure apparatus 10 in the factory is increased.

  Further, in the exposure apparatus 10, the side regions on the + X side and the + Y side of the wafer stage base 12 are empty spaces. Therefore, both wafer stages WST1, WST2 can be easily maintained from the empty space on the long side of wafer stage base 12 where both wafer stages WST1, WST2 are easily accessible.

  Of course, with respect to the wafer stage base 12, a part of the illumination unit ILU is arranged on the + X side of the wafer stage base 12 to make the -X side area empty, and the wafer loader WL is arranged on the + Y side and -Y side. This area may be an empty space.

  As described above in detail, according to the exposure apparatus 10 of the present embodiment, among the regions surrounding the four sides of the wafer stage base 12 having a substantially rectangular shape in plan view on which the support surfaces of the plurality of stages WST1, WST2 are formed, Specific area excluding one side area (+ Y side) along the longitudinal direction (X-axis direction) of wafer stage base 12 and one side area (+ X side) in the short direction perpendicular to the longitudinal direction. At least a part of the illumination unit ILU and a wafer loader WL are arranged. That is, while securing the + Y side region and the + X side region of the wafer stage base 12 as maintenance regions, the wafer loader WL is disposed in the other longitudinal region (−Y side). Yes. In this way, by using one side surface area along the longitudinal direction of wafer stage base 12 as an empty space for maintenance, it becomes possible to maintain maintainability for each stage WST1, WST2, and to The wafer loader WL is disposed in the other side surface region (−Y side) in the longitudinal direction of the wafer stage base 12, so that the wafer loader WL and the illumination unit ILU are provided in at least one of the lateral regions at both longitudinal ends of the wafer stage base 12. It is also possible to adopt a configuration in which a fixed unit such as a part of the exposure apparatus 10 is not arranged, and there is a restriction in arrangement in the length of the exposure apparatus 10 in the horizontal plane (for example, a restriction that it is not elongated in a predetermined direction) in the factory. Can also obtain the degree of freedom of arrangement of the exposure apparatus in the factory

  In the above embodiment, the case where the fixed unit is a part of the illumination unit ILU and the wafer loader WL has been described. However, the present invention is not limited to this, and various units can be adopted. For example, the fixed unit is a storage mechanism (for example, FOUP (Front Opening Unified Pod)) for storing a predetermined number of wafers, or a coater / developer (Coater Developer) for applying a photosensitive agent to the wafer and developing it. It is also possible. Further, as the fixed unit, leg portions 42A to 42D (anti-vibration unit 44) constituting the body 36 that supports the projection optical system PL, the reticle stage RST, and the like can be used. In this case, the leg portions 42A to 42D are used. As described above, it is possible to maintain the maintainability of the exposure apparatus in the same manner as described above by preventing the wafer stage base 12 from being disposed on either one of the ± Y sides of the wafer stage base 12.

  The arrangement of the units constituting the exposure apparatus of the above embodiment is an example, and various other configurations can be employed. For example, as shown in FIG. 4, a movable unit MU may be provided in an empty space near the wafer stage base 12 (a space where no fixed unit is arranged). As the unit that can be easily moved, for example, a unit including a control device including a computer connected to each part of the exposure apparatus, a substrate, various power supplies, and the like can be used. In this case, for example, as shown in FIG. 5, two movable units MU1 and MU2 are used, and each unit MU1 and MU2 is connected to a chamber that covers the outside of the stage device 30 and the like in a state in which the two-way opening is possible. You may do it.

  In addition to the above arrangements, a fixed unit or a movable unit may be arranged near the four corners of the wafer stage base 12. In the above embodiment, the case where the present invention is applied to an exposure apparatus having two off-axis alignment systems corresponding to the respective stages has been described. However, as disclosed in JP-T-2000-511704, The present invention can also be applied to an exposure apparatus in which two wafer stages are installed in a replaceable manner and have only one alignment system.

  In the above embodiment, the scanning direction of wafer stages WST1 and WST2 is the X-axis direction, but the scanning direction may be the Y-axis direction. In this case, it is preferable that a part of the illumination unit ILU is disposed in the vicinity of one end in the Y-axis direction for the above reason, and conversely, in order to secure a maintenance surface along the longitudinal direction of the wafer stage base 12. In addition, it is preferable to arrange the wafer loader WL at one end in the X-axis direction.

  In the above-described embodiment, the configuration including the two wafer stages WST1 and WST2 is adopted as the configuration of the stage apparatus 30, but the present invention is not limited to this. That is, it suffices to have a plurality of wafer stages, and of course, it may have three or more wafer stages.

In the above-described embodiment, far ultraviolet light such as KrF excimer laser light, illumination light IL, vacuum ultraviolet light such as F ₂ laser and ArF excimer laser, or ultraviolet bright line (g-line, However, the present invention is not limited to this, and other vacuum ultraviolet light such as Ar ₂ laser light (wavelength 126 nm) may be used. Further, for example, not only laser light output from each of the above light sources as vacuum ultraviolet light, but also single wavelength laser light in the infrared region or visible region oscillated from a DFB semiconductor laser or fiber laser, for example, erbium (Er) A harmonic that is amplified by a fiber amplifier doped with erbium and ytterbium (Yb) and wavelength-converted into ultraviolet light using a nonlinear optical crystal may be used.

  Further, an exposure apparatus that uses EUV light, X-rays, or charged particle beams such as an electron beam or an ion beam as illumination light IL, a projection system that does not use a projection optical system, such as a proximity type exposure apparatus, a mirror projection aligner, and The present invention may also be applied to an immersion type exposure apparatus disclosed in International Publication WO99 / 49504 and the like in which a liquid is filled between the projection optical system PL and the wafer.

  In the above-described embodiment, the case where the present invention is applied to a scanning exposure apparatus such as a step-and-scan method has been described, but it is needless to say that the scope of the present invention is not limited to this. That is, the present invention can be suitably applied to a step-and-repeat reduction projection exposure apparatus.

  An illumination optical system and projection optical system composed of a plurality of lenses are incorporated into the exposure apparatus body for optical adjustment, and a reticle stage and wafer stage made up of a number of mechanical parts are attached to the exposure apparatus body to provide wiring and piping. , And further performing general adjustment (electrical adjustment, operation check, etc.), the exposure apparatus of the above embodiment can be manufactured. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  The present invention is not limited to an exposure apparatus for manufacturing a semiconductor, but is used for manufacturing a display including a liquid crystal display element. An exposure apparatus for transferring a device pattern onto a glass plate and a device used for manufacturing a thin film magnetic head. The present invention can also be applied to an exposure apparatus that transfers a pattern onto a ceramic wafer, and an exposure apparatus that is used for manufacturing an imaging device (CCD or the like), micromachine, organic EL, DNA chip, and the like. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., glass substrates or silicon wafers, etc. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern. Here, in an exposure apparatus using DUV (far ultraviolet) light, VUV (vacuum ultraviolet) light, or the like, a transmission type reticle is generally used. As a reticle substrate, quartz glass, fluorine-doped quartz glass, meteorite, Magnesium fluoride or quartz is used. Further, in a proximity type X-ray exposure apparatus or an electron beam exposure apparatus, a transmission mask (stencil mask, membrane mask) is used, and a silicon wafer or the like is used as a mask substrate.

  A semiconductor device includes a step of performing functional / performance design of a device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and a reticle by the above-described method using the exposure apparatus of the above-described embodiment. This pattern is manufactured through a step of transferring the pattern to a wafer, a device assembly step (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like.

  As described above, the exposure apparatus of the present invention is suitable for a lithography process for manufacturing semiconductor elements, liquid crystal display elements, and the like.

It is a front view which shows the structure of the exposure apparatus of one Embodiment of this invention. FIG. 2 is a plan view showing an arrangement of a stage device, an illumination unit, and a wafer loader in the exposure apparatus of FIG. 1. It is a figure which shows the relationship between an illumination unit and a scanning direction. It is a figure for demonstrating the modification (the 1) of the layout of the exposure apparatus of one Embodiment. It is a figure for demonstrating the modification (the 2) of the layout of the exposure apparatus of one Embodiment. It is a figure which shows the example of arrangement | positioning of the stage apparatus in a conventional exposure apparatus, an illumination unit, and a wafer conveyance system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10 '... Exposure apparatus, 12 ... Wafer stage base (stage surface plate), 42A-42D ... Support member (fixed unit, leg part), 44 ... Anti-vibration unit (fixed unit), IL ... Illumination light ( Energy beam), ILU ... illumination unit (fixed unit), MU ... unit (movable unit), PL ... projection optical system, R ... reticle (mask), W1, W2 ... wafer (photosensitive object), WL ... wafer loader ( Fixed unit, transfer device), WST1, WST2,... Stage (wafer stage).

Claims (7)

An exposure apparatus that transfers a pattern formed on a mask by an energy beam onto a photosensitive object via a projection optical system,
A plurality of stages for holding the photosensitive object;
A plane plate having a substantially rectangular shape in plan view, on which support surfaces of the plurality of stages are formed;
Among the regions surrounding the four sides of the stage surface plate, at least one of the specific regions excluding the side region along one longitudinal direction of the stage surface plate and the region on one side in the short direction perpendicular to the longitudinal direction. An exposure apparatus comprising: at least one fixed unit, wherein a part or all of the unit is disposed in the unit.   The fixed unit includes an illumination unit that irradiates the mask with the energy beam, a transport device that carries the photosensitive object in and out of the stages, a storage mechanism that stores the photosensitive object, and the projection optics. The exposure apparatus according to claim 1, comprising at least one of a leg portion of a support base that supports a system and an apparatus that performs at least one of application and development of a photosensitive agent to the photosensitive object. The fixed unit is a transport device that carries the photosensitive object in and out of each stage,
The exposure apparatus according to claim 1, wherein the transport apparatus is disposed in a side region along the other longitudinal direction of the stage surface plate.   The exposure apparatus according to any one of claims 1 to 3, further comprising a movable unit disposed in a region on one side of the short direction of the stage surface plate.   The exposure apparatus according to claim 4, wherein the movable unit is a control device that controls the operation of the entire apparatus. The fixed unit is an illumination unit that irradiates the mask with the energy beam;
At least a part of the illumination unit is disposed in a side region along the other lateral direction of the stage surface plate,
When the pattern formed on the mask is transferred onto the photosensitive object, the apparatus further comprises a driving device that synchronously moves the mask and the photosensitive object along the longitudinal direction of the stage surface plate. An exposure apparatus according to any one of claims 1 to 5. The illumination unit includes a folding mirror that folds an optical path of the energy beam to guide the energy beam generated from a light source that generates the energy beam onto the mask;
7. The bending direction of the energy beam and the synchronous movement direction when the mask and the photosensitive object are synchronously moved substantially coincide with each other on the reflection surface of the folding mirror. Exposure equipment.

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