HK1182185B - Measuring method, loading method, exposure method, exposure apparatus, and device production method - Google Patents

Description

Measuring method, loading method, exposure method and exposure apparatus, and device manufacturing method

The present application is a divisional application of an invention patent application entitled "position measuring method, position controlling method, measuring method, loading method, exposure apparatus, and device manufacturing method" filed on 18/11/2005 and filed on 200580038725.9.

Technical Field

The present invention relates to a position measuring method, a position control method, a measuring method, a loading method, an exposure apparatus, and a device manufacturing method, and more particularly, to a position measuring method for measuring position information of a plate detachably loaded on a movable body; a position control method using the position measurement method; a measuring method for measuring information of a plate (having an opening) mounted on a movable body and used for mounting an object; a method of loading an object using the measuring method; an exposure method using the loading method and an exposure apparatus suitable for implementing the methods; and a device manufacturing method using the exposure apparatus or the exposure method.

Background

Conventionally, in a photolithography process for manufacturing electronic devices such as semiconductor devices (integrated circuits) and liquid crystal display devices, a reduction projection exposure apparatus (stepper) of a step-and-repeat system or a projection exposure apparatus (scanning stepper (also referred to as scanner)) of a step-and-scan system is mainly used to transfer a pattern image of a mask or a reticle (hereinafter, collectively referred to as "reticle") to a plurality of irradiation regions on a photosensitive object (hereinafter, referred to as "wafer") such as a wafer or a glass plate coated with a photoresist (photosensitive agent) via a projection optical system.

However, with the miniaturization of circuit patterns with the high integration of semiconductor devices, in order to improve the resolution of a projection optical system provided in a projection exposure apparatus, the wavelength of exposure light (exposure wavelength) is gradually shortened, and the Numerical Aperture (NA) of the projection optical system is gradually increased. On the other hand, the focal depth is reduced due to the shortening of the exposure wavelength and the increase in NA of the projection optical system (large NA). The exposure wavelength will be shorter in the future, and if the depth of focus is too small, the focus margin may be insufficient during the exposure operation.

Therefore, an exposure apparatus using the immersion method has recently been attracting attention as a method of substantially shortening the wavelength for exposure and increasing (widening) the depth of focus as compared with the case of the air. An exposure apparatus using this liquid immersion method is known that performs exposure in a state where a space between the lower surface of the projection optical system and the surface of the wafer is partially filled with a liquid such as water or an organic solvent (for example, see patent document 1). In the exposure apparatus described in patent document 1, the wavelength of the exposure light in the liquid is such that the resolution is improved by the characteristic of 1/n times in air (n is the refractive index of the liquid, and is usually about 1.2 to 1.6), and the resolution similar to the resolution can be increased by n times the depth of focus compared to a projection optical system (which can manufacture such a projection optical system) obtained without using the liquid immersion method, that is, by substantially n times the depth of focus compared to air.

Recently, however, it has been proposed to arrange a plate member, which is detachably attached to a wafer stage of an exposure apparatus and forms a flat portion substantially matching a wafer, around the wafer held on the wafer stage. When such a detachable plate is used for a wafer stage, it is necessary to accurately know the position of the plate.

Further, when a plate member is used as the wafer stage, an opening for positioning a wafer must be formed in the central portion of the plate member (for example, when a semiconductor wafer is used, a circular opening is used), but when the circular opening of the plate member has a low degree of roundness and is deformed into a circular or elliptical shape, for example, a gap between the outer peripheral surface of the wafer and the inner peripheral surface of the opening is varied, and there is a possibility that the wafer comes into contact with the inner wall surface of the opening of the plate member or the wafer cannot be inserted into the opening of the plate member.

Further, since the gap between the opening of the plate and the wafer is very narrow, when the wafer is loaded, if the relative positions of the wafer and the plate are not accurately aligned, the wafer loading operation is not easy.

In addition, in the case of an exposure apparatus using the liquid immersion method, liquid may infiltrate into a portion where a gap between an opening edge of the plate and an outer peripheral edge of the wafer is wide.

(patent document 1) International publication No. 99/49504

Disclosure of Invention

In view of the above 1, a position measuring method according to the present invention is a position measuring method for measuring position information of a plate member of a predetermined shape detachably mounted on a movable body, the position measuring method including:

a peripheral edge position obtaining step of detecting a part of the plate while measuring the position of the movable body by a measuring device defining a movable coordinate system thereof, and obtaining position information of the peripheral edge of the plate based on the detection result and the measurement result of the measuring device corresponding thereto.

Thus, the position of a moving body (a plate member of a predetermined shape is detachably mounted) can be measured by a measuring device of a limited moving coordinate system, a part of the plate member is detected, and the position information of the peripheral edge of the plate member is obtained based on the detection result and the measurement result of the corresponding measuring device. Therefore, the position of the peripheral edge of the plate member can be managed on the moving coordinate system defined by the measuring device.

From the viewpoint of the 2 nd aspect, the position control method of the present invention is a position control method for controlling a position of a movable body on which a plate is detachably mounted; the position of the movable body is controlled based on the positional information of the peripheral edge of the plate measured by the position measuring method of the present invention.

Accordingly, since the position of the movable body is controlled based on the positional information of the peripheral edge of the plate measured by the position measuring method of the present invention, the position of the movable body can be managed in consideration of the position of the peripheral edge of the plate.

Thus, the position control method of the present invention can be used for an exposure apparatus. Therefore, from the 3 rd viewpoint, the 1 st exposure apparatus of the present invention can also use the position control method of the present invention.

From the viewpoint of the 4 th aspect, the present invention provides a measuring method for measuring information on a plate detachably mounted on a movable body and having an opening for mounting an object formed therein, the measuring method comprising:

an inner peripheral edge position obtaining step of detecting a part of the plate member and obtaining position information of an inner peripheral edge of the opening based on a result of the detection.

In this way, information on a plate which is detachably mounted on the movable body and has an opening for mounting the object is detected, and position information of the inner peripheral edge of the opening is obtained based on the detection result. Therefore, the position or shape of the opening can be calculated based on the position information of the inner peripheral edge.

From the viewpoint of 5, the loading method of the present invention is a method for loading an object on a movable body which detachably mounts a plate having an opening for loading the object; the object is loaded in the opening of the plate on the movable body based on the position information of the inner peripheral edge of the opening of the plate obtained by the measuring method of the present invention.

Accordingly, the object is loaded in the opening of the plate on the movable body based on the position information of the inner peripheral edge of the opening of the plate obtained by the measuring method of the present invention. Therefore, it is easy to load the object in the opening of the plate on the movable body.

From the viewpoint of 6, the 1 st exposure method of the present invention is an exposure method for exposing an object, comprising the steps of:

loading the object into the opening of the plate on the movable body using the 1 st loading method of the present invention; and

an exposure beam is irradiated on the object loaded on the moving object.

In this way, according to the 1 st loading method of the present invention, the object is loaded in the opening of the plate on the movable body, and the exposure light beam is irradiated to the object loaded on the movable body to perform exposure.

From the 7 th viewpoint, the 2 nd loading method according to the present invention is a method for loading an object to be processed in a concave portion at an upper end portion of a movable body, comprising the steps of:

loading an object into a recess in the movable body; and

an acquisition step of acquiring positional relationship information between the inner peripheral edge of the recess and the object loaded in the recess.

Here, "object" also includes the concept of an object to be processed. That is, in the loading step, the object to be processed may be loaded in the recess of the movable body, or another object, for example, a dedicated object for the purpose of obtaining the above positional relationship may be loaded.

In any case, the obtaining step obtains information on the positional relationship between the inner peripheral edge of the recess and the object loaded in the recess. Therefore, the object can be mounted in the recess of the movable body in a desired positional relationship based on the acquired positional relationship.

From the viewpoint of 8, the exposure method of the invention, which is the 2 nd exposure method for exposing an object to be processed, comprises the steps of:

loading the object to be processed in the concave portion of the movable body by using the 2 nd loading method of the present invention; and

the exposure light beam is irradiated to the object to be processed mounted in the recess of the movable body.

In this way, according to the 2 nd loading method of the present invention, the object to be processed is loaded in the concave portion of the movable body, and the exposure light beam is irradiated to the object to be processed loaded in the concave portion of the movable body to perform exposure.

From the 9 th viewpoint, the 2 nd exposure apparatus according to the present invention is an exposure apparatus for irradiating an object with an exposure beam, comprising:

a 1 st stage for detachably mounting a plate member having a predetermined shape;

a position measurement system for measuring the position of the 1 st stage;

a detection device for detecting a part of the 1 st stage; and

a peripheral edge position acquiring device for detecting a part of the plate by the detecting device while measuring the position of the 1 st stage by the position measuring system, and acquiring position information of the peripheral edge of the plate based on the detection result and the measurement result of the position measuring system.

In this way, the peripheral edge position acquisition device uses the position measurement system to measure the 1 st stage position of a plate detachably mounted on a predetermined shape, while the detection device detects a part of the plate, and acquires the position information of the peripheral edge of the plate based on the detection result and the measurement result of the corresponding position measurement system. Therefore, the position of the peripheral edge of the board mounted on the stage 1 can be managed in the moving coordinate system defined by the position measurement system.

From the viewpoint of 10, the 3 rd exposure apparatus of the present invention is for irradiating an object with an exposure beam; it is provided with:

an exposure stage on which a plate having a predetermined shape and an opening is formed, the opening being loaded with an object;

a position measurement system for measuring a position of the exposure stage;

a detection device which can detect a part of the exposure stage; and

an inner peripheral edge position obtaining device measures the position of the exposure stage by using the position measuring system, detects a part of the plate by using the detecting device, and obtains position information of the inner peripheral edge of the opening based on the detection result and the corresponding measurement result of the position measuring system.

In this way, the inner peripheral edge position acquisition means detects a part of the plate by the detection means while measuring the position of the exposure stage by the position measurement system, and acquires the position information of the inner peripheral edge of the opening based on the detection result and the measurement result of the position measurement system. Therefore, the information such as the position or shape of the opening can be obtained based on the position information of the inner peripheral edge.

In the photolithography step, the exposure apparatus of the present invention of the 1 st to 3 rd is used, thereby forming a pattern on an object with good precision, and thereby, a microdevice can be manufactured with high yield. Similarly, in the photolithography step, the patterns can be formed on the object with high precision by using the 1 st and 2 nd exposure methods of the present invention, and thereby, the microdevice can be manufactured with high yield. Therefore, from another point of view, the device manufacturing method of the present invention uses any one of the 1 st to 3 rd exposure apparatuses or any one of the 1 st and 2 nd exposure methods.

Drawings

Fig. 1 is a schematic configuration diagram showing an exposure apparatus according to an embodiment.

Fig. 2 is a perspective view showing the stage device of fig. 1.

Fig. 3 is a perspective view showing the measurement stage of fig. 1.

Fig. 4 is a plan view showing a wafer table.

Fig. 5 is a diagram illustrating the configuration of an interferometer system.

FIG. 6 is a block diagram showing a main configuration of a control system of an exposure apparatus according to an embodiment.

Fig. 7 is a flowchart showing a processing algorithm of the main control device (internal CPU) in the return operation to the reference state of the wafer table.

Fig. 8 is a diagram for explaining the processing algorithm start condition shown in the flowchart of fig. 7, and shows an example of the position of the wafer table WTB at the start thereof.

Fig. 9(a) to (D) show the state in which the measurement points No. 1, No. 2, No. 3, and No. 4 are positioned in the imaging field of view of the alignment system when the positional information of the peripheral edge of the liquid-repellent plate is acquired.

Fig. 10(a) shows a state where the wafer table WTB moves when position information of a plurality of measurement points on the + Y-side end edge of the liquid-repellent plate is measured in sequence, and fig. 10(B) shows a state where 3-point measurement points are set on all the edges of 4 sides.

Fig. 11 is a flowchart (1) showing a processing algorithm of the main controller (internal CPU) when a series of processes are performed from the exchange of the liquid repellent plates on the wafer stage to the exchange of the next liquid repellent plate.

Fig. 12 is a flowchart (2) showing a processing algorithm of the main controller (internal CPU) when a series of processes are performed from the exchange of the liquid repellent plates on the wafer stage to the exchange of the next liquid repellent plate.

Fig. 13 is a flowchart showing the sub-path of step 222.

Fig. 14 is a flowchart showing the sub-path of step 236.

Fig. 15(a) to (D) show the state in which the measurement points No. 1, No. 2, No. 3, and No. 4 are positioned in the imaging field of view of the alignment system when the positional information of the inner peripheral edge of the opening of the liquid repellent plate is acquired.

Fig. 16(a) to (D) show the state in which the measurement points No. 5, No. 6, No. 7, and No. 8 are positioned in the imaging field of view of the alignment system when the positional information of the inner peripheral edge of the opening of the liquid repellent plate is acquired.

FIG. 17(A) is a schematic conceptual view showing a state of acquiring the shot data at 8 on the inner peripheral edge of the opening, and FIG. 17(B) is a schematic conceptual view showing a state of acquiring the shot data at 8 on the outer peripheral edge of the wafer for the tool.

Fig. 18 is an enlarged side view showing the vicinity of the edge of the liquid repellent plate.

Fig. 19(a) to (D) are (a) to (D) diagrams illustrating modifications.

Fig. 20(a) to (C) are diagrams (two) for explaining modifications.

Detailed Description

An embodiment of the present invention will be described below with reference to fig. 1 to 17 (B).

Fig. 1 is a schematic configuration of an exposure apparatus 100 according to a preferred embodiment of the present invention, which schematically illustrates an implementation of a position measurement method, a position control method, a measurement method, a loading method, and an exposure method. The exposure apparatus 100 is a projection exposure apparatus of step-and-scan type, i.e., a scanning stepper (also referred to as a scanner). The exposure apparatus 100 includes: illumination system 10, reticle stage RST for holding reticle R, projection unit PU, stage device 150 (having wafer stage WST and measurement stage MST), and control systems for these. A wafer is loaded on wafer stage WST.

The illumination system 10 is composed of a light source, an illuminance uniformizing optical system including an optical integrator [ fly eye lens, rod integrator (internal reflection type integrator), diffractive optical element, etc. ], a beam splitter, a relay lens, a variable NA filter, a reticle shield, etc. (all not shown), as disclosed in, for example, japanese patent application laid-open No. 2001-313250 and U.S. patent application laid-open No. 2003/0025890 corresponding thereto. The disclosures in the above-mentioned publications and the corresponding U.S. patent application publications are incorporated herein by reference as if allowed by the national laws of the designated country (or selected country of choice) specified in the international application.

The illumination system 10 illuminates a slit-shaped illumination region defined by a reticle mask on a reticle R with substantially uniform illumination by illumination light (exposure light) IL as an exposure beam. As an example of the illumination light IL, an ArF excimer laser (having a wavelength of 193nm) can be used.

On reticle stage RST, reticle R on which a circuit pattern or the like is formed on its pattern surface (the lower surface in fig. 1) is fixed by, for example, vacuum suction. Reticle stage RST is, for example, micro-drivable in an XY plane perpendicular to the optical axis of illumination system 10 (coinciding with optical axis AX of projection optical system PL described later) by a reticle stage driving unit 11 (not shown in fig. 1, see fig. 6) including a linear motor or the like, and is drivable at a scanning speed specified in a predetermined scanning direction (here, the Y-axis direction in the left-right direction in the sheet of fig. 1).

The position (including the rotation around the Z axis) of reticle stage RST within the stage moving surface is continuously detected with a resolution of, for example, about 0.5 to 1nm by a reticle laser interferometer (hereinafter referred to as "reticle interferometer") 116 through a moving mirror 15 (actually, a Y moving mirror (having a reflecting surface orthogonal to the Y axis direction) and an X moving mirror (having a reflecting surface orthogonal to the X axis direction) are provided). The measurement values of reticle interferometer 116 are transmitted to main control device 20 (not shown in fig. 1, see fig. 6), and main control device 20 calculates the positions of reticle stage RST in the X-axis direction, the Y-axis direction, and the θ Z direction (the rotational direction around the Z axis) based on the measurement values of reticle interferometer 116, and controls reticle stage driving unit 11 based on the calculation results, thereby controlling the position (and speed) of reticle stage RST. Instead of the movable mirror 15, the end surface of the reticle stage RST may be mirror-finished to form a reflecting surface (corresponding to the reflecting surface of the movable mirror 15).

Above reticle R, a pair of reticle alignment detection systems RAa, Rab composed of TTR (through-resist) alignment systems that use light of an exposure wavelength to simultaneously observe a pair of reticle alignment marks on reticle R and a pair of reference marks (hereinafter referred to as "1 st reference marks") on corresponding measurement stage MST through projection optical system PL are provided in the X-axis direction at predetermined intervals. As the reticle alignment detection systems RAa and RAb, for example, those having the same configuration as disclosed in japanese patent application laid-open No. 7-176468 (corresponding to U.S. Pat. No. 5,646,413) can be used. The disclosures in the above-mentioned publications and the corresponding U.S. patent specifications are incorporated as part of the description of the present specification, as far as the national regulations permit the designated country (or selected country) specified in the international application.

Projection unit PU is arranged below reticle stage RST in fig. 1. The projection unit PU is constituted by a lens barrel 40 and a projection optical system PL (constituted by a plurality of optical elements held in a predetermined positional relationship in the lens barrel 40). As the projection optical system PL, a refractive optical system (composed of a plurality of lenses (lens elements) having an optical axis AX common in the Z-axis direction) can be used. The projection optical system PL is, for example, telecentric on both sides and has a predetermined projection magnification (for example, 1/4 or 1/5 times). Therefore, the illumination area on the reticle R is illuminated with the illumination light IL from the illumination system 10, and the circuit pattern reduced image (reduced image of a part of the circuit pattern) of the reticle R in the illumination area is formed in an area (exposure area) conjugate to the illumination area on the wafer W coated with the resist (photosensitive agent) on the surface thereof by the illumination light IL transmitted through the reticle R through the projection optical system PL (projection unit PU).

In addition, since the exposure apparatus 100 of the present embodiment performs exposure by using the liquid immersion method, the aperture on the reticle side becomes larger as the numerical aperture NA substantially increases. Therefore, in a refractive optical system composed of only lenses, the Petzval (Petzval) condition is not easily satisfied, and the projection optical system tends to be large in size. In order to avoid an increase in size of the projection optical system, a catadioptric system including a mirror and a lens may be used.

Since the exposure apparatus 100 of the present embodiment performs exposure by using the liquid immersion method, a liquid supply nozzle 51A (constituting the liquid immersion mechanism 132) and a liquid recovery nozzle 51B are provided in the vicinity of a lens (hereinafter, also referred to as a "front lens") 91 constituting an optical element on the most image plane side (wafer side) of the projection optical system PL.

The liquid supply nozzle 51A has one end connected to a supply pipe (not shown in fig. 1, see fig. 6) not shown, and the liquid recovery nozzle 51B has one end connected to a recovery pipe (not shown in fig. 1, see fig. 6) not shown).

The liquid supply device 88 is composed of a liquid storage tank, a pressure pump, a temperature control device, and a valve (for controlling supply and stop of liquid to the supply pipe). In the case of a valve, for example, not only can the supply and stop of liquid but also the flow rate can be adjusted, and it is preferable to use a flow rate control valve. The temperature control device adjusts the temperature of the liquid in the liquid storage tank to the same temperature as the temperature in a chamber (not shown) that houses the exposure apparatus main body.

Further, the storage tank, the pressure pump, the temperature control device, and the valve for supplying the liquid do not need to be provided in the exposure apparatus 100, and at least a part of the equipment such as a factory in which the exposure apparatus 100 is installed may be replaced.

The liquid recovery device 92 is composed of a liquid storage tank, a suction pump, and a valve (for controlling the recovery and stop of the liquid through a recovery tube). As the valve, a flow control valve is preferably used corresponding to the valve on the liquid supply device 88 side.

Further, the storage tank, the suction pump, and the valve for recovering the liquid are not necessarily all provided in the exposure apparatus 100, and at least a part of the equipment such as a factory in which the exposure apparatus 100 is installed may be replaced with the equipment.

As the liquid, ultrapure water (hereinafter, simply referred to as "water" unless otherwise particularly required) which transmits ArF excimer laser light (having a wavelength of 193nm) can be used herein. Ultrapure water is easily available in large quantities in semiconductor manufacturing plants and the like, and has an advantage of not adversely affecting a resist, an optical lens, or the like on a wafer.

The refractive index n of water to ArF excimer laser light is approximately 1.44. In this water, the wavelength of the illumination light IL is shortened to about 134nm, i.e., 193nm × 1/n.

The liquid supply device 88 and the liquid recovery device 92 each have a controller, and each controller is controlled by the main control device 20 (see fig. 6). The controller of the liquid supply device 88 opens a valve connected to a supply pipe at a predetermined opening degree in response to an instruction from the main control device 20, and supplies water between the front lens 91 and the wafer W (or a plate described later) through the liquid supply nozzle 51A. At this time, the controller of the liquid recovery device 92 opens the valve connected to the recovery pipe at a predetermined opening degree in response to an instruction from the main controller 20, and recovers water from between the front lens 91 and the wafer W into the liquid recovery device 92 (liquid storage tank) through the liquid recovery nozzle 51B. At this time, the main controller 20 gives commands to the controller of the liquid supply device 88 and the controller of the liquid recovery device 92 so that the amount of water supplied from the liquid supply nozzle 51A and the amount of water recovered by the liquid recovery nozzle 51B are continuously kept equal between the front lens 91 and the wafer W. Therefore, the water Lq held between the front lens 91 and the wafer W is continuously renewed.

As is clear from the above description, the liquid immersion mechanism 132 of the present embodiment is a local liquid immersion mechanism constituted by the liquid supply device 88, the liquid recovery device 92, the supply pipe, the recovery pipe, the liquid supply nozzle 51A, the liquid recovery nozzle 51B, and the like, and forms a liquid immersion area in a part of the wafer W when exposing the wafer W.

In addition, when measurement stage MST is provided below projection unit PU, water can be filled between measurement stage MTB and front lens 91, which will be described later, in the same manner as described above.

In the above description, for the sake of simplifying the description, the liquid supply nozzle and the liquid recovery nozzle are provided separately, but the invention is not limited thereto, and a configuration having a plurality of nozzles may be adopted, for example, as disclosed in the pamphlet of international publication No. 99/49504. The configuration may be any as long as liquid can be supplied mainly between the optical member (front lens) 91 constituting the lowermost end of the projection optical system PL and the wafer W. For example, the liquid immersion mechanism disclosed in international publication No. 2004/053955 or the liquid immersion mechanism disclosed in european patent publication No. 1420298 can be applied to the exposure apparatus of the present embodiment.

Stage device 150 includes a frame FC, a base plate 12 provided on frame FC, a wafer stage WST and a measurement stage MST arranged above the upper surface of base plate 12, an interferometer system 118 (see fig. 6) as a position measurement system (including interferometers 16 and 18 as position measurement devices for measuring the positions of these stages WST and MST), and a stage driving unit 124 (see fig. 6) for driving stages WST and MST.

As is apparent from fig. 2 showing stage device 150 in a perspective view, frame FC is formed of substantially flat plate-like members integrally formed with projecting portions FCa and FCb projecting upward with the Y-axis direction as the longitudinal direction in the vicinity of one side and the other side end in the X-direction.

The chassis 12 is formed of a plate-like member called a surface plate, and is disposed in a region between the convex portions FCa and FCb of the frame FC. The flatness of the upper surface of base plate 12 is made extremely high, and serves as a guide surface for movement of wafer stage WST and measurement stage MST.

As shown in fig. 2, wafer stage WST includes: a wafer stage body 28 disposed on the base plate 12; and a wafer table WTB mounted on the wafer stage main body 28 as an exposure stage by a Z tilt drive mechanism, not shown. The Z tilt driving mechanism is actually configured by 3 actuators (e.g., voice coil motors) or the like that support the wafer table WTB at 3 points, and is capable of micro-driving in a 3-degree-of-freedom direction in the Z-axis direction, the θ X direction (rotational direction around the X axis), and the θ Y direction (rotational direction around the Y axis).

The wafer stage main body 28 is a hollow member having a rectangular frame shape in cross section and extending in the X-axis direction. A plurality of, for example, 4 air hydrostatic bearings (for example, air bearings), not shown, are provided on the lower surface of this wafer stage main body 28, and the wafer stage WST is supported in a non-contact manner above the guide surface through a gap of about several μm by these air bearings.

As shown in fig. 2, a Y-axis fixing member 86 extending in the Y-axis direction is disposed above the protruding portion FCa of the frame FC. Similarly, a Y-axis fixing member 87 extending in the Y-axis direction is disposed above the convex portion FCb of the frame FC. The Y-axis fixing members 86 and 87 are supported above the convex portions FCa and FCb in a floating manner with a predetermined gap by an air hydrostatic bearing (for example, an air bearing) provided on the lower surface (not shown). The Y-axis fixing members 86 and 87 are constituted by magnetic pole units having a plurality of permanent magnets arranged at predetermined intervals in the Y-axis direction in the present embodiment.

Movable member 90 is provided inside wafer stage body 28, and is composed of a U-shaped magnetic pole unit having a plurality of permanent magnets and having a predetermined cross section, which is arranged at a predetermined interval in the X-axis direction.

In the internal space of the movable member 90, the X-axis fixing member 80 is inserted in the X-axis direction. The fixing member 80 for the X-axis is composed of armature units having a plurality of armature coils arranged at predetermined intervals in the X-axis direction. In this case, a moving magnet type X-axis linear motor that drives wafer stage WST in the X-axis direction is configured by movable member 90 including a magnetic pole unit and X-axis fixed member 80 including an armature unit. Hereinafter, the X-axis linear motor is referred to as an X-axis linear motor 80 as appropriate, using the same reference numeral as the fixing member (X-axis fixing member) 80. Moving coil type linear motors may also be used.

Movable members (for example, armature units having a plurality of armature coils disposed at predetermined intervals in the Y-axis direction) 82 and 83 are fixed to one end and the other end of the X-axis fixing member 80 in the longitudinal direction, respectively. The movable members 82 and 83 are inserted into the Y-axis fixing members 86 and 87 from the inside, respectively. That is, in the present embodiment, the movable members 82 and 83 formed of the armature units and the Y-axis fixed members 86 and 87 formed of the magnetic pole units constitute a moving-coil type 2Y-axis linear motor. Hereinafter, the 2Y-axis linear motors are referred to as a Y-axis linear motor 82 and a Y-axis linear motor 83 as appropriate, using the same reference numerals as those of the movable members 82 and 83. In addition, moving magnet linear motors may be used as the Y-axis linear motors 82 and 83.

That is, wafer stage WST is driven in the X-axis direction by X-axis linear motor 80, and is driven in the Y-axis direction integrally with X-axis linear motor 80 by a pair of Y-axis linear motors 82 and 83. Further, wafer stage WST can be rotationally driven in the θ z direction by slightly different driving forces in the Y axis direction generated by Y axis linear motors 82 and 83.

As shown in the plan view of fig. 4, the wafer table WSB is substantially square in plan view, and on the top surface thereof, a chuck type wafer holder WH for holding the wafer W and a plate holder PH are provided.

As shown in fig. 4, the wafer holder WH includes: a plurality of 1 st pins 32(32, … …) provided at predetermined intervals in a circular region of a predetermined area in the center portion of the upper surface of the wafer table WTB, a 1 st edge portion 30 (constituted by an annular convex portion surrounding the circular region in which the 1 st pins 32, … … are arranged), and 3 cylindrical 2 nd edge portions 35A, 35B, 35C (each provided at each apex position of a substantially square shape having a distance equal to the center of the circular region (holder center)). The front end of each 1 st pin 32, the 1 st edge 30, and the upper end surfaces of the 2 nd edges 35A, 35B, and 35C are set to be substantially the same height.

Through holes 39 circular in plan view are formed in the inner peripheries of the 2 nd rim portions 35A, 35B, and 35C, respectively, and each of the through holes has a cylindrical shape inside, and movable up-down moving pins (central convex portions) 34a, 34B, and 34C are provided in the up-down direction (the direction perpendicular to the paper surface in fig. 4). These 3 central convex portions 34a to 34c are raised and lowered (moved up and down) by the same amount in the vertical direction (the Z-axis direction perpendicular to the paper surface in fig. 4) by a vertical movement mechanism (not shown) constituting the stage driving unit 124 (see fig. 6). When wafers are loaded and unloaded, the center projections 34a to 34c are driven by the vertical movement mechanism, and the wafer W is supported from below by the center projections 34a to 34c, and can be moved vertically in this state.

In a circular area surrounded by the 1 st edge portion 30 on the upper surface of the wafer table WTB, as shown in fig. 4, the plurality of exhaust ports 36 are formed radially (in a direction of 3 radial lines having a central angle interval of approximately 120 °) at predetermined intervals from the center (holder center) of the circular area. The exhaust ports 36 are formed at positions not interfering with the 1 st pin 32. The exhaust ports 36 are connected to exhaust passages 38A, 38B, and 38C formed in the wafer table WTB through pipes directly below the exhaust ports, respectively, and the exhaust passages 38A, 38B, and 38C are connected to a 1 st vacuum exhaust mechanism 44 through vacuum exhaust pipes 41a, 41B, and 41C, respectively (see fig. 6).

In the present embodiment, when the main controller 20 starts the vacuum evacuation operation by the 1 st vacuum evacuation mechanism 44 after the wafer W is loaded on the wafer holder WH of the wafer table WTB, the inside of the space surrounded by the wafer W and the 1 st edge portion 30 and the 32 nd edge portions 35A, 35B, and 35C is brought into a negative pressure state, and the wafer W is sucked and held by the plurality of 1 st edge portions 32 and the 1 st edge portions 30 and the 32 nd edge portions 35A, 35B, and 35C.

A3 rd edge 45 formed of an annular convex portion concentric with the 1 st edge 30 is protruded outside the 1 st edge 30 on the upper surface of the wafer table WTB. On the outer side of the 3 rd edge portion 45, a recess 49 is formed, the inner side of which is partitioned by the 3 rd edge portion 45 and the outer side of which is surrounded by an outer partition wall 48 of the wafer table WTB. A plurality of 2 nd pins 53 are provided at predetermined intervals on the inner bottom surface of the recess 49, and the height of the tip thereof is the same as the 3 rd edge 45 and the outer partition wall 48. In this case, the height of the 3 rd edge 45 and the upper end surface of the outer partition wall 48 is set to be slightly lower than that of the 1 st partition wall. A liquid repellent plate (for example, a water repellent plate) 50 of a substantially square plate member having a circular opening 50a at the center is detachably mounted on the 3 rd edge portion 45, the outer partition wall 48, and the plurality of 2 nd pins 53 configured as described above. The liquid deflector 50 is mounted on the wafer table WTB in a state that its outer peripheral surface is slightly projected outward from the outer surface of the outer partition wall 48 of the wafer table WTB. That is, the plate holder PH of the chuck type for holding the liquid repellent plate 50 is constituted by including the 3 rd edge portion 45 and the outer partition wall 48 on the upper surface of the wafer table WTB and the plurality of 2 nd pins 53.

Here, in the region where the plurality of 2 nd pins 53 partitioned by the 3 rd edge portion 45 and the outer partition wall 48 constituting the plate holder PH are provided, similarly to the wafer holder WH, a plurality of exhaust ports (not shown) are formed at predetermined intervals, and each exhaust port is connected to an unillustrated exhaust passage formed inside the wafer table WTB through a corresponding one of the pipes directly below the exhaust port, and the unillustrated exhaust passages are connected to a 2 nd vacuum ejector mechanism 56 shown in fig. 6 through corresponding one of the vacuum exhaust pipes not shown.

In the present embodiment, the main controller 20 causes the space (the internal space of the concave portion 49) surrounded by the liquid repellent plate 50, the 3 rd edge portion 45, and the outer partition wall 48 to be vacuum-sucked by the 2 nd vacuum exhaust mechanism 56, and the liquid repellent plate 50 is sucked and held by the plate holder PH. Here, for example, since the liquid repellent plate 50 is easily detached, the vertical movement pins similar to the central convex portions 34a to 34c are provided in the space, and the main control device 20 may control the driving mechanism of the vertical movement pins.

In the present embodiment, the heights of the portions constituting the wafer holder WH and the plate holder PH are set so that the upper surface of the liquid repellent plate 50 sucked and held by the plate holder PH and the surface of the wafer W sucked and held by the wafer holder WH are substantially at the same height (see fig. 1). In the state of being held by the plate holder PH, the inner peripheral edge of the opening 50a of the liquid repellent plate 50 is substantially coincident with the inner peripheral wall of the 3 rd edge portion 45. That is, in the present embodiment, the recess 140 for loading the wafer W is formed inside the 3 rd edge portion 45 and the inner wall surface of the opening 50a of the liquid deflector 50, and the wafer holder WH is provided in the recess 140. Further, the shape and size of the opening 50a are set to a value of about 0.1 to 0.4mm, for example, as a gap between the outer peripheral edge of the wafer W and the inner peripheral edge of the opening 50a of the liquid-repellent plate 50. The wafer W is held by the wafer holder WH, and an outer surface of the wafer table WTB is formed to be entirely flat.

The wafer table WTB is formed of a material having a low thermal expansion coefficient (for example, a material having a certain degree of elasticity such as ceramic), and the 1 st edge 30, the 2 nd edge 35A, 35B, 35C, the 3 rd edge 45, the plurality of 1 st pins 32, the plurality of 2 nd pins 53, and the like are integrally formed by etching the surface of the material having a substantially square shape as a whole.

The surface of the liquid repellent plate 50 is subjected to a liquid repellent treatment using a fluorine-based material or the like (here, a liquid repellent treatment such as a liquid repellent coating is performed), thereby forming a liquid repellent surface (water repellent surface). The liquid (water) repellent surface of the liquid repellent plate 50 generally cannot withstand light in the far ultraviolet region or the vacuum ultraviolet region, and the exposure light deteriorates the liquid (water) repellent performance. Further, since there is a possibility that a liquid adhering trace (water mark or the like) is formed on the upper surface of the liquid repellent plate 50, the liquid repellent plate 50 can be easily attached and detached (replaced). The liquid repellent plate 50 may be held not only by vacuum suction but also by another method such as electrostatic suction.

Further, a photoresist (photosensitive agent) is coated on the surface of the wafer W. In this embodiment, the photosensitizer used is, for example, a photosensitizer for ArF excimer laser light, and has liquid repellency (water repellency, contact angle of 80 ° to 85 °). Of course, a material having a top coat layer having liquid repellency (a contact angle with a liquid is 90 ° to 120 °) may be applied on the upper layer of the sensitizer. The surface of the wafer W may not necessarily have liquid repellency, and a resist having a contact angle with liquid of about 60 ° to 80 ° may be used. In addition, a liquid repellent treatment may be applied to at least a part of the side surface and the back surface of the wafer W. Similarly, a liquid repellent treatment may be applied to at least a part of the wafer holder WH and the plate holder PH.

The position of wafer table WTB configured as described above is measured by interferometer system 118 (see fig. 6), and will be described later.

As shown in fig. 2, the measurement system MST is configured by a combination of a plurality of members such as a Y stage 81 whose longitudinal direction is the X-axis direction, and is supported in a non-contact manner above the upper surface (guide surface) of the base plate 12 by a plurality of air hydrostatic bearings (for example, air bearings) provided at the lowermost surface (lower surface of the member closest to the base plate 12) thereof through a gap of about several μm.

As is apparent from the perspective view of fig. 3, measurement stage MST includes: a Y stage 81 having a pair of convex portions 81a and 81b fixed to a rectangular plate-shaped measuring stage body 81c elongated in the X axis direction and to one side and the other side in the X axis direction of an upper surface of the measuring stage body 81c, respectively; a leveling table 52 disposed above the upper surface of the measuring system main body 81c, and a measuring table MTB provided on the leveling table 52.

Movable members 84 and 85 each composed of an armature unit (in which a plurality of armature coils are arranged at predetermined intervals in the Y-axis direction) are fixed to one side end surface and the other side end surface in the X-axis direction of a measurement stage main body 81c constituting the Y stage 81. The movable members 84 and 85 are inserted into the Y-axis fixed members 86 and 87, respectively, from the inside. That is, in the present embodiment, two moving coil type Y-axis linear motors are configured by the movable members 84 and 85 configured by the armature units and the Y-axis fixed members 86 and 87 configured by the magnetic pole units into which both the movable members 84 and 85 are inserted. Hereinafter, the two Y-axis linear motors are also referred to as a Y-axis linear motor 84 and a Y-axis linear motor 85, respectively, using the same reference numerals as those of the movable members 84 and 85. In the present embodiment, the entire measurement stage MST is driven in the Y axis direction by these Y axis linear motors 84, 85. In addition, the Y-axis linear motors 84 and 85 can be used as moving magnet type linear motors.

The plurality of aerostatic bearings are provided on the bottom surface of the measuring stage body 81 c. The pair of projections 81a and 81b are fixed so as to face each other in the vicinity of the + Y-side end on one side and the other side in the X-axis direction of the upper surface of the measurement stage main body 81 c. The fixing members 61 and 63 extending in the X-axis direction in the XY plane are provided in the Z-axis direction (up and down) at predetermined intervals between the projections 81a and 81 b.

A movable member of the X voice coil motor 54a is provided on the + X-side end surface of the leveling stage 52, and a fixed member of the X voice coil motor 54a is fixed to the upper surface of the measurement stage main body 81 c. Movable members of Y voice coil motors 54b and 54c are provided on the-Y-side end surface of the leveling table 52, and fixed members of the Y voice coil motors 54b and 54c are fixed to the upper surface of the measurement stage main body 81 c. The X voice coil motor 54a is composed of, for example, a movable member composed of a magnetic pole unit and a fixed member composed of an armature unit, and generates a driving force in the X axis direction by electromagnetic interaction between these members. The Y voice coil motors 54b and 54c are also configured in the same manner, and generate a driving force in the Y axis direction. That is, in the leveling stage 52, the Y stage 81 is driven in the X-axis direction by the X voice coil motor 54a, and the Y stage 81 is driven in the Y-axis direction by the Y voice coil motors 54b and 54 c. Further, by making the driving forces generated by the Y voice coil motors 54b and 54c different, the leveling stage 52 can drive the Y stage 81 in the direction of rotation around the Z axis (θ Z direction).

Inside the leveling table 52, 3Z voice coil motors (not shown) that generate driving force in the Z-axis direction are disposed, respectively.

That is, the leveling stage 52 can be driven in the 6-degree-of-freedom direction (X, Y, Z, θ X, θ Y, θ Z) in a minute manner in a non-contact manner by the X voice coil motor 54a, the Y voice coil motors 54b, 54c, and a Z voice coil motor (not shown) disposed inside.

Referring back to fig. 3, the measurement table MTB includes: a measuring table main body 59; and movable members 62 and 64 each having a substantially U-shaped cross section, with the X-axis direction of the + Y side surface fixed to the measurement stage main body 59 in parallel in the up-down direction being taken as the longitudinal direction.

The movable member 62 includes: a movable member yoke having a YZ cross section in a substantially U shape; and a permanent magnet group composed of a plurality of groups of N-pole permanent magnets and S-pole permanent magnets alternately arranged on the inner surface (upper and lower surfaces) of the movable member yoke at predetermined intervals in the X-axis direction, and engaged with the fixed member 61. An alternating magnetic field is formed in the X-axis direction in the internal space of the movable member yoke of the movable member 62. The fixing member 61 is composed of an armature unit (for example, a plurality of armature coils arranged at predetermined intervals in the X-axis direction are provided inside). That is, the fixed member 61 and the movable member 62 constitute a moving magnet type X-axis linear motor LX that drives the measurement table MTB in the X-axis direction.

The movable member 64 includes: a movable member yoke having a YZ cross section in a substantially U shape; and an N-pole permanent magnet and an S-pole permanent magnet provided on the inner surface (upper and lower surfaces) of the movable member yoke, respectively, and engaged with the fixed member 63. A magnetic field in the + Z direction or the-Z direction is formed in the internal space of the movable member yoke of the movable member 64. The fixing member 63 includes: the armature coil is configured to flow a current only in the X-axis direction in a magnetic field formed inside the armature coil by using an N-pole magnet and an S-pole magnet. That is, the movable member 64 and the fixed member 63 constitute a moving magnet type Y voice coil motor VY which drives the measurement table MTB in the Y axis direction.

As is clear from the above description, in the present embodiment, the stage driving unit 124 shown in fig. 6 is configured by the Y-axis linear motors 82 to 85 and the X-axis linear motor 80, the Z tilt driving mechanism (not shown) for driving the wafer table WTB, and the motors (54a to 54c, LX, VY, and the Z voice coil motor (not shown) on the measurement stage. Various drive mechanisms constituting stage drive unit 124 are controlled by main control device 20 shown in fig. 6.

The measuring table MTB further includes: and measuring instruments for performing various measurements related to exposure. To describe this in more detail, a plate 101 made of a glass material such as Zerodur (trade name of Schott corporation) or quartz glass is provided on the upper surface of the measurement stage main body 59. The plate 101 is coated with chromium over substantially the entire surface thereof, and is provided with a measuring area, a high-low reference reflection surface area used for measuring the reticle transmittance, or a reference mark area FM [ in which a plurality of reference marks are formed as disclosed in japanese patent application laid-open No. 5-21314 (corresponding to U.S. patent No. 5,243,195) or 10-050600 (corresponding to U.S. patent No. 6,243,158) ]. The reference mark region constitutes a measuring member. The surface of the plate member 101 is a flat surface. The disclosures in the above-mentioned publications and the corresponding U.S. patent specifications are incorporated as a part of the description of the present specification, as far as the national regulations permit the designated country (or the selected country) specified in the international application.

The measurement area is patterned and various measurement opening patterns are formed. As the aperture pattern for measurement, for example, an aperture pattern for aerial image measurement (for example, slit-shaped aperture pattern), a pinhole aperture pattern for uneven illumination measurement, an aperture pattern for illuminance measurement, an aperture pattern for wavefront aberration measurement, and the like are formed.

A light receiving system is provided in the measurement stage main body 59 below the aerial image measurement opening pattern, and receives the exposure light irradiated to the plate 101 through the projection optical system PL and water through the aerial image measurement opening pattern, thereby forming an aerial image measuring instrument disclosed in, for example, japanese patent application laid-open No. 2002-14005 (corresponding to U.S. patent application publication No. 2002/0041377), and measuring the light intensity of the pattern aerial image (projection image) projected by the projection optical system PL. The disclosures in the above-mentioned publications and the corresponding U.S. patent application publications are incorporated herein by reference as if allowed by the national laws of the designated country (or selected country of choice) specified in the international application.

Further, a light receiving system including a light receiving element is provided in the measuring stage main body 59 below the pinhole opening pattern for uneven illumination measurement, thereby constituting an uneven illuminance measuring instrument [ for example, disclosed in japanese patent application laid-open No. 57-117238 (corresponding to U.S. patent No. 4,465,368), etc. ], which has a pinhole-shaped light receiving unit that receives the illumination light IL on the image plane of the projection optical system PL. The disclosures in the above-mentioned publications and the corresponding U.S. patent specifications are incorporated as part of the description of the present specification, as far as the national regulations permit the designated country (or selected country) specified in the international application.

Further, a light receiving system including a light receiving element is provided in the measurement stage main body 59 below the illuminance measurement aperture pattern, and an illuminance monitor (disclosed in, for example, japanese patent application laid-open No. 11-16816 (corresponding to U.S. patent application publication No. 2002/0061469) or the like) is configured to have a light receiving unit of a predetermined area for receiving the illumination light IL through water on the image plane of the projection optical system PL. The disclosures in the above-mentioned publications and the corresponding U.S. patent application publications are incorporated herein by reference as if allowed by the national laws of the designated country (or selected country of choice) specified in the international application.

Further, a light receiving system including, for example, a microlens array is provided in the measuring table main body 59 below the aperture pattern for measuring wavefront aberration, thereby constituting a wavefront aberration measuring instrument [ for example, disclosed in international publication No. 99/60361 pamphlet (corresponding to european patent No. 1,079,223), and the like ]. The disclosures in the above-mentioned international pamphlet and the corresponding european patent specification are incorporated as a part of the description of the present specification, as far as the national regulations permit the designated country (or the selected country) specified in the international application.

In fig. 6, the aerial image measuring instrument, the uneven illuminance measuring instrument, the illuminance monitor, and the wavefront aberration measuring instrument are shown as a measuring instrument group 43.

In the present embodiment, immersion exposure for exposing the wafer W is performed by exposure light (illumination light) IL through the projection optical system PL and water, and the illumination light IL is received through the projection optical system PL and water by the illuminance monitor, the illuminance unevenness measuring instrument, the aerial image measuring instrument, the wavefront aberration measuring instrument, and the like used for measurement using the illumination light IL. Therefore, a water repellent coating may be applied to the surface of the plate 101. Further, each of the measuring instruments described above may be mounted on measuring stage MST only in part of the optical system and the like, or may be disposed entirely on measuring stage MST. The aerial image measuring instrument, the illuminance unevenness measuring instrument, the illuminance monitor, and the wavefront aberration measuring instrument do not necessarily have all of them, and may be mounted only partially as needed.

The position of measurement stage MST (measurement stage MTB) configured as described above is measured by interferometer system 118 (see fig. 6) described later.

The exposure apparatus 100 according to the present embodiment is provided with an off-axis alignment system (hereinafter, simply referred to as "alignment system" ALG) as shown in fig. 1, as a holding member for holding the projection unit PU. As this alignment system ALG, a sensor of a field alignment (field alignment) system of an image processing system is used, and for example, a sensor of a field alignment (field alignment) system disclosed in japanese patent application laid-open No. 2001-257157 (corresponding to U.S. patent application publication No. 2001/0023918), japanese patent application laid-open No. 8-213306 (corresponding to U.S. patent application publication No. 2001/0023918), or japanese patent application laid-open No. 8-213306 (corresponding to U.S. patent application publication No. 5,783,833) irradiates a wide-band detection light beam that does not expose a resist on a wafer to light onto a target mark, and uses a photographic element (CCD or the like) to photograph an image of the target mark imaged on a light receiving surface and an image of an unillustrated index (index pattern on an index plate provided in the alignment system ALG) using reflected light from the target mark, and outputs the photographic signal. The photographing signal from the alignment system ALG is supplied to the main control device 20 of fig. 6. The disclosures in each of the above-mentioned publications and the corresponding U.S. patent application publications or U.S. patent specifications are incorporated as part of the description of the present specification as long as they are permitted by the national laws of the designated country (or the selected country) specified in the international application.

It is to be noted that the alignment system ALG is not limited to the FIA system, and it is needless to say that the alignment sensor may be singly or appropriately combined to irradiate coherent (coherent) detection light to the target mark, detect scattered light or diffracted light generated from the target mark, or detect by interfering two diffracted lights (for example, diffracted lights of the same order or diffracted lights diffracted in the same direction) generated from the target mark.

Further, the optical element or the holding member for holding the optical element of the alignment system ALG may be disposed near the moving surface of the wafer table WTB, and a water-repellent cover may be provided to a member where liquid may be attached by scattering of the liquid. Further, a sealing member such as an O-ring is disposed in a gap between the optical element and a holding member for holding the optical element, in which there is a concern that liquid may infiltrate into the alignment system ALG. Further, the surface of the optical member disposed in the vicinity of the surface on which the wafer table WTB moves, such as the surface of the optical element at the end of the alignment system ALG or the surface of the interferometer mirror fixed to the alignment system ALG, is coated with a liquid repellent material, and therefore, not only is water prevented from adhering thereto, but also an operator or other operator can easily wipe off the surface even if water adheres thereto.

Further, although not shown in fig. 1, the exposure apparatus 100 of the present embodiment is provided with a multi-point focus detection system of an oblique incidence system including an irradiation system 90a and a light receiving system 90b (see fig. 6), for example, as disclosed in japanese patent application laid-open No. 6-283403 (corresponding to U.S. Pat. No. 5,448,332). In the present embodiment, for example, the illumination system 90a is supported by a holding member for holding the projection unit PU in a suspended manner on the-X side of the projection unit PU, and the light receiving system 90b is supported by a holding member in a suspended manner on the + X side of the projection unit PU. That is, the illumination system 90a and the light receiving system 90b are mounted on the same member as the projection optical system PL, and the positional relationship therebetween is maintained constant. The disclosures in the above-mentioned publications and the corresponding U.S. patent specifications are incorporated as a part of the description of the present specification, as far as the national regulations permit the designated country (or the selected country) specified in the international application.

Next, the configuration and operation of the interferometer system 118 will be described.

the-X side end surface and the-Y side end surface of the wafer table WTB are mirror-finished to form reflection surfaces 17X and 17Y, respectively, as shown in fig. 2. the-X side end surface, + Y side end surface, and-Y side end surface of the measurement table MTB are mirror-finished to form reflection surfaces 117X and 117Y, respectively₁、117Y₂。

The interferometer system 118 is composed of the Y-axis interferometers 16, 18, 78 and the X-axis interferometers 46, 66, 76, as shown in FIG. 5.

The Y-axis interferometers 16 and 18 each have a longitudinal axis parallel to the Y-axis and connecting a projection center (optical axis AX) of the projection optical system PL and a detection center of the alignment system ALG. The Y-axis interferometers 16, 18 are multi-axis interferometers having at least 3 optical axes, the output of each optical axis being independently measurable. The X-axis interferometer 46 has a length measurement axis that perpendicularly intersects the projection center of the projection optical system PL at the length measurement axis of the Y-axis interferometers 16 and 18. The X-axis interferometers 46, 66 are multi-axis interferometers having at least 2 optical axes, the output of each optical axis being independently measurable. The output values (measurement values) of the above 4 interferometers 16, 18, 46, 66 are supplied to the main control device 20 shown in fig. 6. For example, in the state of fig. 5, the interferometer beam (length measuring beam) from the Y-axis interferometer 16 is projected on the reflection surface 117Y of the measurement table WTB₁The interferometer beam (length measuring beam) from the Y-axis interferometer 18 is projected onto the reflection surface 17Y of the measurement table WTB, the interferometer beam (length measuring beam) from the X-axis interferometer 46 is projected onto the reflection surface 117X of the measurement table WTB, and the interferometer beam (length measuring beam) from the X-axis interferometer 66 is projected onto the reflection surface 17X of the measurement table WTB. The interferometers 16, 18, 46, and 66 receive the reflected light from the respective reflection surfaces of the respective optical axis length measuring beams, and thereby measure the displacement in the measurement direction from the reference position of the respective reflection surfaces (generally, a fixed mirror is disposed on the side surface of the projection unit PU or the side surface of the off-axis alignment system ALG (see fig. 6, 5, and the like) as a reference surface for each optical axis.

In the case of fig. 5, the main controller 20 measures not only the position (Y position) of the wafer table WTB in the Y axis direction but also the amount of rotation (longitudinal rotation) around the X axis and the amount of rotation (yaw) around the Z axis based on the output value from the Y-axis interferometer 18. The main controller 20 measures not only the Y-axis position (Y position) of the measurement table MTB but also the amount of rotation around the X axis (longitudinal rotation amount) and the amount of rotation around the Z axis (yaw amount) based on the output from the Y-axis interferometer 16. The main controller 20 measures not only the position (X position) of the wafer table WTB in the X-axis direction but also the amount of rotation (amount of lateral rotation) around the Y-axis based on the output value (measurement value) from the X-axis interferometer 66. The main controller 20 measures the X position and the amount of lateral rotation of the measurement table MTB based on the output value (measurement value) from the X-axis interferometer 46.

As can be seen from fig. 5, in the present embodiment, the interferometer beams from Y-axis interferometer 18 are projected continuously onto movable mirror 17Y over the entire transfer range during alignment and exposure of wafer stage WST, and the interferometer beams from Y-axis interferometer 16 are projected continuously onto movable mirror 117Y over the entire transfer range of measurement stage MST₁. Therefore, the Y-position of stages WST and MST is managed by main control device 20 based on the measurement values of Y-axis interferometers 18 and 16, except for the case where wafer stage WST moves to the wafer exchange position shown in fig. 5 by a two-point chain line, for example.

On the other hand, as is also apparent from fig. 2 and 5, main controller 20 controls the X position of wafer table WTB (wafer stage WST) based on the output value of X-axis interferometer 46 only on the range irradiated by reflection surface 17X by the interferometer beam from X-axis interferometer 46, and controls the X position of measurement table MTB (measurement stage MST) based on the output value of X-axis interferometer 46 only on the range irradiated by reflection surface 117X by the interferometer beam from X-axis interferometer 46.

In main controller 20, the interferometer beams from X-axis interferometer 46 and X-axis interferometer 66 include a range irradiated by reflection surface 17X, and the X position of wafer table WTB (wafer stage WST) is managed by X-axis interferometer 66 at the time of wafer alignment, and the X position of wafer table WTB (wafer stage WST) at the time of exposure is managed by X-axis interferometer 46. Thus, the X position of wafer table WTB (wafer stage WST) can be controlled without Abbe (Abbe) error even during wafer alignment and exposure.

The remaining X-axis interferometer 76 and Y-axis interferometer 78 are interferometers for managing the position of wafer stage WST when they are located near the wafer exchange position that cannot be managed by interferometers 46, 66, and 18. Based on the measured values of these interferometers 76, 78, main controller 20 manages the position of wafer table WTB (wafer stage WST) during the X position period based on the output values of interferometers 46, 66, 18.

When measurement stage MST is further positioned at the standby position on the + Y side from the state of fig. 5, X-axis interferometer 66 does not irradiate reflection surface 117X with the interferometer beam from X-axis interferometer 46, of course. When measuring stage MST is moved in the-Y direction in this state, main controller 20 resets X-axis interferometer 46 that cannot be controlled at that time from a state in which the interferometer beams from X-axis interferometer 46 are not irradiated onto reflection surface 117X at the time point after reflection surface 117X starts to be irradiated, and then manages the X position of measuring stage MTB (measuring stage MST) using X-axis interferometer 46. The other interferometers can perform a reset (link reset) operation using the outputs (measurement values) of the adjacent interferometers. That is, before the time point when the interferometer is reset, the measurement beams from the two adjacent interferometers are simultaneously irradiated onto the reflection surface, and before that, the interferometer to be reset is reset (preset) using the measurement values of the X-axis interferometer or the Y-axis interferometer used for the position control of the wafer stage WST or the measurement stage MST, whereby the reset interferometer can be used without any problem, and the position of the wafer stage WST or the measurement stage MST can be managed. Of course, when the measurement table MTB is located at the standby position, an interferometer for measuring the position of the measurement table MTB in the X axis direction may be added.

Further, the exposure apparatus 100 of the present embodiment, and the waferThe wafer exchange position (loading position) at which the baseline measurement of reticle alignment and alignment system ALG is performed with wafer stage WST can be positioned near the + X-side end and near the-Y-side end of the movable range of wafer stage WST. When wafer stage WST is present at the wafer exchange position, the interferometer beam (measurement beam) from Y-axis interferometer 18 is irradiated onto reflection surface 117Y of measurement table MTB₂Therefore, first, the main control device 20 resets the measurement value of the Y-axis interferometer 18. Subsequently, the main controller 20 uses the reset Y-axis interferometer 18 and X-axis interferometer 46 to manage the position of the measurement stage MTB, and starts a series of operations of baseline measurement by the reticle alignment and alignment system ALG. This is because the position of measurement table MTB is managed using Y-axis interferometer 18 used for position measurement of wafer table WTB (wafer stage WST) at the time of wafer alignment and exposure, and the baseline is measured using reference mark region FM on measurement table MTB, and the position of wafer table WTB at the time of exposure is controlled using the measured baseline, thereby preventing the occurrence of a position error due to a difference in interferometers used for control.

In the present embodiment, during reticle alignment, the main controller 20 controls the opening and closing of the valves of the liquid supply device 88 and the liquid recovery device 92 of the liquid immersion mechanism 132 as described above, and water is continuously filled between the front lens 91 of the projection optical system PL and the reference mark region FM of the measurement table WTB. Next, main controller 20 detects the relative positions (1 st relative positions) of at least one pair of 1 st fiducial marks on fiducial mark area FM of at least one pair of reticle alignment marks on reticle R with reticle alignment detection systems RAa and RAb, and then measurement table WTB moves fiducial mark area FM to a position directly below alignment system ALG based on the design value of the baseline, detects the 2 nd fiducial mark on fiducial mark area FM with alignment system ALG in a state where water Lq is not present on fiducial mark area FM, and detects the relative position (2 nd relative position) of the detection center of alignment system ALG and the 2 nd reference. Next, the main controller 20 calculates a baseline of the alignment system ALG based on the designed values of the 1 st and 2 nd relative positions and the baseline and the positional relationship between the pair of the 1 st reference mark and the 2 nd reference mark.

In the present embodiment, the interferometer system 118 of fig. 6 is configured by three Y-axis interferometers 16, 18, 78 and three X-axis interferometers 46, 66, 76, but the configuration of such an interferometer system is merely an example, and the present invention is not limited thereto.

Returning to fig. 1, exposure apparatus 100 is provided with a transfer arm 70 that transfers a wafer to wafer stage WST. The transfer arm 70 is preferably one that transfers a wafer between a pre-alignment device, not shown, that detects the center position and rotation angle of the wafer and a wafer stage WST positioned for wafer exchange, and may be a sliding type arm or a horizontal articulated robot arm. The present embodiment includes: the transfer arm 70, a pre-alignment device (not shown), and a transfer unit for transferring the pre-alignment device from the outside constitute a transfer system 72 (see fig. 6) for transferring the wafer to the wafer stage WST.

Fig. 6 shows a main configuration of a control system of the exposure apparatus 100. The control system is composed of a main control device 20[ which is composed of a microcomputer (or a workstation) for comprehensively controlling the whole devices ].

Further, the positions of wafer table WTB and measurement table MTB in the XY plane can be measured with a resolution of about 0.5 to 1nm by the respective interferometers of interferometer system 118 as described above, but since liquid ejecting plate 50 of the present embodiment does not have a mark or the like as a position measurement reference, it is difficult to return wafer table WTB to a reference state (or a state before the last interferometer beam is turned off) after, for example, interferometer beams from all Y-axis interferometers or all X-axis interferometers are not irradiated on the reflection surface of wafer table WTB and at least one interferometer is reset. In the present embodiment, since the periphery of the liquid deflector 50 extends outward from the wafer table WTB (reflection surface), it is difficult to control the position of the wafer table WTB in order to avoid collision of the peripheral edge of the liquid deflector 50. In particular, it is not easy to control the position of the wafer table WTB after the exchange of the liquid-repellent plate 50. In view of this, the exposure apparatus 100 according to the present embodiment measures the position of the liquid-repellent plate 50 by the main controller 20 as described below, and performs position management of the wafer table WTB based on the measurement result.

Fig. 7 is a flowchart showing, for example, a processing algorithm of the main controller 20 (internal CPU) when the operation of the liquid-repellent plate 50 is returned to the reference state of the wafer table WTB. The start of this processing algorithm is when the wafer stage WST is moved to the position shown in fig. 8 after the measurement values of interferometer 18 are reset. At this time, the position of wafer table WTB is managed by main controller 20 based on the measurement values of interferometers 18 and 76. In addition, the rotation error of the wafer table WTB itself in the theta-z direction is small enough to be ignored. As described above, while the aforementioned preset linking of the interferometer measurement values is executed when wafer table WTB (wafer stage WST) or the like is moved, in the following description of the processing algorithm, for the sake of simplifying the description thereof, the description of the preset linking of the interferometer measurement values or the like is omitted, and the position of wafer table WST (wafer table WTB) is managed on a stage coordinate system (X, Y) defined by the longitudinal axis of interferometer system 118. It is considered that even this assumption is not particularly problematic since the measurement values of the adjacent X-axis interferometer and the measurement value of the Y-axis interferometer are sequentially replaced by the link default.

First, in step 202 of fig. 7, the count value n of the 1 st counter indicating the number of the peripheral edge measurement points of the liquid dial 50 is initialized to 1(n ← 1). Here, the number of regions to be measured is limited to N, and here, 4 regions, that is, the center points of the upper, lower, left, and right edges of the liquid repellent plate 50 are limited.

In a next step 204, the position of wafer table WTB is measured using interferometer system 118, and wafer stage WST for positioning the n-th (here, No. 1) measurement point on the peripheral edge of liquid repellent plate 50 directly below alignment system ALG is moved.

Fig. 9 a shows a case where No. 1 measurement point on the outer peripheral edge of liquid repellent plate 50 on wafer table WTB (wafer stage WST) is positioned in the imaging field of alignment system ALG. In fig. 9(a) to 9(D), a symbol ALG' indicates a field of view of the alignment system ALG.

Referring back to fig. 7, in step 206, the nth measurement point (here, 1 st) on the peripheral edge is photographed by using the alignment system ALG, and the photographed data (photographing signal) is acquired, and the measurement value of the interferometer system 118 at that time is acquired and stored in the memory (not shown) corresponding to both.

Next, in step 208, it is determined whether or not the count value N of the 1 st counter has reached N (where N is 4), and since N is 1, the determination is negative, and the process proceeds to step 210, where the count value N of the 1 st counter is incremented by 1, and the process returns to step 204.

Thereafter, until the determination in step 208 is affirmative, the loop processing in step 204 → 206 → 208 → 210 is repeated. With this, the wafer table positions are sequentially positioned from the position shown in fig. 9(a) to the positions shown in fig. 9(B), 9(C), and 9(D), the outer peripheral edge of the liquid-repellent plate 50 is photographed at each of the positioned positions by the alignment system ALG, and the position information of the wafer table WTB corresponding to the photographed data is stored in the memory.

When the acquisition of the negative X-side edge image of the liquid repellent plate 50 shown in fig. 9(D) is completed, the determination in step 208 is affirmative, and the process proceeds to step 212.

In step 212, position information of peripheral edge measurement points of the number 1 to the number N (here, number 4) of the liquid-repellent plate 50 is obtained by an image processing method based on the imaging data (imaging result) of each edge stored in the memory and the measurement result of the corresponding interferometer system 118.

Next, in step 214, the position information of the liquid-repellent plate 50, for example, the position information on the stage coordinate system (X, Y) of a predetermined reference point (for example, the center point) of the liquid-repellent plate 50, is calculated based on the obtained position information of the peripheral edge of N positions (here, 4 positions), and then, after the process of step 216 is performed as necessary, the process shown in the flowchart of fig. 7 is completed.

Based on the thus measured position information of the outer peripheral edge of liquid repellent plate 50 or the position information of liquid repellent plate 50, the position of wafer table WTB is thereafter managed by main controller 20, for example, main controller 20, so that the outer peripheral edge of liquid repellent plate 50 mounted on wafer table WTB does not collide with measuring stage WST, and at least one of the position of wafer table WTB (wafer stage WST) and the position of measuring stage MST is controlled based on the position information of the outer peripheral edge of liquid repellent plate 50 or the position information of liquid repellent plate 50.

Here, for example, when the processing of step 216 is performed, the positional information of a part of the wafer holder is obtained in the same manner as the positional information of the aforementioned liquid-repellent plate 50, and the positional relationship between the wafer holder WH (wafer table WTB) and the liquid-repellent plate is calculated based on the positional information and the positional information of the liquid-repellent plate 50 obtained in step 212 or 214.

Here, for example, also in the case of measuring θ z rotation of the liquid repellent plate 50, a plurality of positions (i.e., 5 or more in total) are set in advance for measuring the peripheral edge of the liquid repellent plate 50 on at least one edge, and the processing is preferably performed according to the same flowchart as that of the aforementioned fig. 7. FIG. 10(A) shows the movement of wafer table WTB when position information of a plurality of measurement points on the edge of the end of the + Y-side is measured sequentially. Next, in step 214, the position information of the liquid-repellent plate 50 preferably includes the position information of the reference point, and the θ z rotation of the edge (i.e., the rotation angle to the stage coordinate system of the liquid-repellent plate 50) is also calculated based on the position information of at least 2 points on the edge set in the plurality of measurement target areas.

In this case, a plurality of measurement points may be set on all the four edges of the liquid repellent plate 50, and θ z rotation of each edge may be determined. For example, as shown in the schematic diagram of fig. 10(B), 3-point measurement points may be set on all the edges of four sides, and the average value of θ z rotations of each obtained edge may be calculated.

In reality, although the imaging field of view ALG 'of the alignment system ALG is fixed and the wafer table WTB moves, the imaging field of view ALG' is shown to move relative to the fixed wafer stage WTB for convenience in fig. 10 (B).

In the present embodiment, the outer peripheral edge of the liquid repellent plate 50 is imaged at a plurality of positions including 2 positions symmetrical with respect to the approximate center of the liquid repellent plate 50, but the imaging position is not limited thereto, and the positions 2 asymmetrical with respect to the approximate center of the liquid repellent plate 50 may be used. For example, the peripheral edge may be photographed at a plurality of positions including one peripheral edge of one side of the liquid repellent plate 50 and one peripheral edge of the other side opposite to the one side. In this case, since substantially symmetrical images of at least the peripheral edges of the two opposing sides can be obtained, the positional information (e.g., the center position) of the liquid-repellent plate 50 can be calculated.

Next, a series of processes performed by the exposure apparatus 100 according to the present embodiment from the exchange of the liquid ejecting plates on the wafer table WTB to the exchange of the next liquid ejecting plate will be described based on the flowcharts of fig. 11 and 12 showing the processing algorithm of the main controller 20 (internal CPU). In the following description of the processing algorithm, the description of the default connection of the interferometer measurement values is omitted, and the position of wafer stage WST (wafer stage WTB) is managed on a stage coordinate system (X, Y) defined by the long axis of interferometer system 118.

First, in step 222 of fig. 11, a sub-path process for measuring positional information of the inner peripheral edge of the opening of the liquid-repellent plate is performed.

In the sub-path of step 222, first, in step 302 of fig. 13, a count value m of a 2 nd counter indicating the order of measurement points at the inner peripheral edge of the opening 50a of the liquid-repellent plate 50 is initialized to 1(m ← 1). Here, M, here 8, are defined as the measurement points, that is, 8 points including the intersection points of 8 lines extending radially in 8 directions at a center angle of 45 ° in the vertical and horizontal directions from the center of the opening 50a of the liquid repellent plate 50 and the inner peripheral edge are defined.

Next, in step 304, the position of wafer table WTB is measured using interferometer system 118, and the measurement point of the m-th position (here, 1 st position) on the inner peripheral edge of opening 50a of liquid-repellent plate 50 is positioned directly below the imaging field of view of alignment system ALG, and wafer table WTB (wafer stage WST) is moved.

Fig. 15(a) shows a case where the measurement point No. 1 is positioned in the imaging field of view of the alignment system ALG. Note that in fig. 15(a) to 15(D) and 16(a) to 16(D), a symbol ALG' indicates an imaging field of view of the alignment system ALG.

Next, in step 306, the m-th (here, 1 st) measurement point on the inner peripheral edge of the opening 50a is photographed by using the alignment system ALG, and the photographed data (photographing signal) is captured, and the measurement value of the interferometer system 118 at this time is captured and stored in the memory (not shown) corresponding to both.

Next, in step 308, it is determined whether or not the count value M of the 2 nd counter reaches M (here, M is 8), and since M is 1, the determination is negative, and the process proceeds to step 310, where the count value M of the 2 nd counter is incremented by 1, and the process returns to step 304.

Thereafter, until the determination in step 308 is affirmative, the loop processing in step 304 → 306 → 308 → 310 is repeated. With this, wafer table WTB is sequentially positioned from the position shown in fig. 15(a) to the positions shown in fig. 15(B), fig. 15(C), fig. 15(D), fig. 16(a), fig. 16(B), fig. 16(C), and fig. 16(D), the inner peripheral edge of opening 50a of liquid-repellent plate 50 is photographed at each positioning position using alignment system ALG, and the position information of wafer table WTB with the photographed data is stored in the memory.

Next, when the acquisition of the image data of the No. 8 measurement point on the inner peripheral edge of the opening 50a shown in fig. 16(D) is completed, the determination in step 308 is affirmative, and the process proceeds to step 314. At this point, as shown in the schematic view of fig. 17(a), the imaging data at 8 on the inner peripheral edge of the opening 50a and the corresponding position information data of the wafer table WTB are stored in the memory. In reality, although the imaging field of view ALG 'of the alignment system ALG is fixed and the wafer table WTB moves, the imaging field of view ALG' is shown to move relative to the fixed wafer table WTB in fig. 17(a) for convenience.

In step 314, the position information of the measurement points from 1 st to M th (here, 8 th) on the inner peripheral edge of the opening 50a of the liquid-repellent plate 50 is obtained by an image processing method based on the imaging data (imaging result) stored in M (here, 8 th) on the inner peripheral edge of the opening 50a in the memory and the measurement result of the corresponding interferometer system 118, and then the sub-path processing is completed, and the process returns to step 224 of the main path (see fig. 11).

In step 224, based on the obtained position information of the inner peripheral edge of the opening 50a at M (here, 8), for example, position information of the opening 50a of the liquid-repellent plate 50 is calculated by the least squares method, for example, position information on the stage coordinate system (X, Y) of a predetermined reference point (for example, the center point) of the opening 50a is calculated (that is, based on the position information of the inner peripheral edge, the positional relationship between the stage coordinate system defined by the interferometer system 118 and the opening 50a is determined), and the process proceeds to step 226.

In step 226, the shape information of the liquid-repellent plate 50a (the shape information includes at least the roundness of the opening 50 a) is calculated by a predetermined operation based on the position information of the inner peripheral edge of the opening 50a at the position M (here, 8 positions). Here, the roundness represents an evaluation amount indicating a deviation from an ideal true circle of the opening 50a, and can be defined by a difference between a maximum radius and a minimum radius of the center of the opening 50a with respect to the contour of the opening 50 a. Here, the center of the circle serving as the roundness standard may be calculated by any of the following methods a to d. a. Minimum zone center Method (MZC): center with the smallest difference in radius of the concentric circles when separating the opening profiles by two concentric circles, b. Center of least square mean circle (circle in which the sum of squares of deviations from the reference circle becomes minimum), c. minimum circumscribed circle center Method (MCC): center of circle with minimum circumscribed opening profile, d. maximum inscribed circle center Method (MIC): at the center of the circle of maximum inscribed opening profile.

Next, in step 228, it is determined whether or not the roundness degree calculated in step 226 is smaller than the 1 st threshold value. Here, the 1 st threshold is a limit value that is defined as an allowable use of the liquid repellent plate. Accordingly, in the case where the determination at step 228 is negative, the liquid-repellent plate 50 forms a plate having an opening with insufficient circularity to such an extent that the exposure apparatus cannot be used, and therefore the process proceeds to step 264 of fig. 12, and, for example, the liquid-repellent plate failure is notified to the operator on a display (not shown), for example, to "liquid-repellent plate failure (replacement is required)", and the present process is completed. Then, by confirming the notification (display), the operator stops the operation of the exposure apparatus 100 and manually performs the exchange of the liquid repellent plate 50. In the case where a robot or the like for exchanging the liquid repellent plates 50 is provided, the main control device 20 displays the exchange timing on the display, and stops the operation of the device, so that the exchange of the liquid repellent plates can be performed by using the robot or the like.

On the other hand, if the determination at step 228 is affirmative, the process proceeds to step 230, where it is determined whether or not the roundness degree calculated at step 226 is smaller than the 2 nd threshold value. Subsequently, if the determination is negative, the process proceeds to step 234, where a tool wafer W1 (see fig. 17B) as a tool substrate is loaded onto the wafer holder WH in the opening 50a of the liquid-repellent plate 50 using the transfer arm 70 of the transfer system 72 and the above-described center projections 34a to 34c, and then the process proceeds to a sub-path where positional information of the object peripheral edge in the opening is measured in step 236. Here, the tool wafer W1 has a smaller diameter periphery (outer diameter) than the wafer W as the object to be processed used for device fabrication. On the contrary, if the determination in step 230 is affirmative, the process proceeds to step 232, where the wafer W is loaded on the wafer holder WH inside the opening 50a of the liquid repellent plate 50 by using the transfer arm 70 of the transfer system 72 and the above-described central convex portions 34a to 34c, and then the process proceeds to the sub-path of step 236. Here, at the time of loading, first, the position of at least one of wafer table WTB and transfer arm 70 is controlled based on the position information of the inner peripheral edge of opening 50a obtained in step 222 or the position information of opening 50a obtained in step 224.

Therefore, the 2 nd threshold is defined by selecting the separation of the tool wafer W1 or the wafer W. When the roundness of the opening 50a is high, the opening 50a and the diameter thereof are slightly different, and the wafer W for device fabrication can be mounted on the wafer holder WH inside the opening 50a without being obstructed, but when the roundness of the opening 50a is low, the wafer W is likely to contact the inner peripheral edge of the opening 50a when the wafer W is mounted on the wafer holder WH inside the opening 50a, and the mounting may be difficult. In the latter case, therefore, the tool wafer W1 having a smaller diameter than the wafer W is loaded on the wafer holder WH.

In the sub-path of step 236, first, in step 322 of fig. 14, the count value k of the 3 rd counter indicating the measuring point number of the outer peripheral edge of the object (tool wafer W1 or wafer W, hereinafter referred to as a representative wafer W1) in the opening 50a is initialized to 1(k ← 1). Here, K, here, 8 points are defined as the measurement points, that is, 8 points at which 8 lines radially extending in 8 directions including a center angle of 45 ° in the vertical and horizontal directions from the center of the tool wafer W1 intersect with the outer peripheral edge of the tool wafer W1.

Next, in step 324, the position of wafer table WTB is measured using interferometer system 118, and the measurement point of the k-th position (here, position No. 1) on the outer peripheral edge of tool wafer W1 in opening 50a of liquid-repellent plate 50 is positioned directly below the imaging field of view of alignment system ALG, and wafer table WTB (wafer stage WST) is moved.

Next, in step 326, the k-th (in this case, No. 1) measurement point on the outer peripheral edge of the tool wafer W1 is photographed by using the alignment system ALG, and the photographed data (photographing signal) is captured, and the measurement value of the interferometer system 118 at this time is captured and stored in a memory (not shown) corresponding to both.

Next, in step 328, it is determined whether or not the count value K of the 3 rd counter reaches K (here, K is 8), and since K is 1, the determination is negative, and the process proceeds to step 330, where the count value K of the 3 rd counter is incremented by 1, and the process returns to step 324.

Thereafter, until the determination in step 328 is affirmative, the loop processing in step 324 → 326 → 328 → 330 is repeated. Thus, as shown in fig. 17(B), wafer table WTB is sequentially positioned at positions where 8 measurement points are located within the imaging field ALG' of alignment system ALG, and the peripheral edge of tool wafer W1 is imaged at each positioning position using alignment system ALG, and the positional information of wafer table WTB corresponding to the imaging data is stored in the memory.

Then, when the acquisition of the imaging data of the No. 8 measurement point on the outer peripheral edge is completed, the determination in step 328 is affirmative, and the process proceeds to step 332.

In step 332, based on the imaging data (imaging result) at K (here, 8) on the outer peripheral edge of the object (tool wafer W1 (or wafer W)) stored in the memory in the opening 50a and the corresponding measurement result of the interferometer system 118, the position information of the measurement points No. 1 to No. K (here, No. 8) on the outer peripheral edge of the object in the opening 50a is obtained by an image processing method, and the sub-path processing is completed, and the main path is returned to step 240 (see fig. 12).

In step 240, the positional relationship between the inner peripheral edge of the opening 50a and the object in the opening 50a is obtained. Specifically, the positional relationship between the inner peripheral edge of the opening 50a and the object in the opening 50a, for example, the positional deviation between the center of the opening 50a and the object in the opening 50a, for example, the center of the opening 50a and the center of the object (tool wafer W1 or wafer W) is obtained by calculation based on the positional information of the above-mentioned K (here, 8) on the outer peripheral edge of the object in the opening 50a, for example, the positional information on the stage coordinate system (X, Y) of the center of the object calculated by the least squares method or the like and the positional information of the opening 50a of the liquid-repellent plate 50 obtained in the above-mentioned step 224 (for example, the positional information on the stage coordinate system (X, Y) of the center of the opening 50 a).

Next, in step 242, wafer stage WST is moved to the wafer exchange position, and the object (tool wafer W1 or wafer W) is unloaded from wafer holder WH using transfer arm 70 and center convex portions 34a to 34c of transfer system 72.

In the next step 244, 1 lot (a predetermined number of wafers) of exposure is started.

In step 244, the wafer W as the 1 st substrate to be exposed to be subjected to the pre-alignment (centering and rotation adjustment) is transferred to the upper side of the wafer stage WST located at the wafer exchange position by the pre-alignment device (not shown) constituting the transfer system 72 using the transfer arm 70, and the positional relationship between the transfer arm 70 and the wafer stage WST is adjusted by taking into account the information on the positional relationship between the inner peripheral edge of the opening 50a and the object in the opening 50a obtained in step 204, for example, the aforementioned deviation information, and the wafer W is loaded from the transfer arm 70 onto the wafer holder WH provided on the wafer table WTB. Here, adjustment of the positional relationship between transfer arm 70 and wafer stage WST can be achieved by adjusting the position of one or both of transfer arm 70 and wafer stage WST. Therefore, when wafer W is loaded, by adjusting the positional relationship between transfer arm 70 and wafer stage WST, and then loading wafer W, wafer W can be loaded on wafer holder WH inside the inner peripheral edge of opening 50a of liquid-repellent plate 50 above wafer table WTB (inside the recess on the upper surface of wafer table WTB) so that the outer peripheral edge of wafer W is normally prevented from coming into contact with the inner peripheral edge of liquid-repellent plate 50a (the inner peripheral edge of recess 140 on the upper surface of wafer table WTB) and the interval between the outer peripheral edge of wafer W and the inner peripheral edge of opening 50a is smaller than a predetermined value, for example, by about 0.3 mm.

Next, in step 246, wafer stage WST is moved to below alignment system ALG.

Next, in step 248, the entire periphery of the wafer W is extended, and the gap between the inner peripheral edge of the opening 50a of the liquid deflector 50 and (the outer peripheral edge of) the wafer W is executed by the same procedure as the measurement of the positional information of the outer peripheral edge of the wafer W or the like using the alignment system ALG. In this case, particularly, when measuring the outer peripheral edge of the wafer or the inner peripheral edge of the opening, it is important to set at least a plurality of sets of measurement points in directions different from the 8 directions from the center of the wafer.

Next, in step 250, it is determined whether the interval is within the allowable range around the entire wafer based on the measurement result of step 248. In general, as described above, the wafer W can be loaded on the wafer holder WH so that the outer peripheral edge of the wafer W does not contact the inner peripheral edge of the liquid deflector 50a (the inner peripheral edge of the recess 140 on the upper surface of the wafer table WTB) and the interval between the outer peripheral edge of the wafer W and the inner peripheral edge of the opening 50a is smaller than, for example, about 0.3mm, and therefore the determination in step 250 is affirmative, and the process proceeds to step 252.

On the other hand, the result of the determination of step 250 is obtained from the measurement result of step 248 due to the outer diameter error of wafer W or the like, and the result of the determination may be negative. Accordingly, if the determination at step 250 is negative, the process proceeds to step 242, where the 1 st wafer W is unloaded from the wafer holder. Next, the operations of step 244, step 246, step 248, and step 250 are performed on the 2 nd wafer W in the same manner as described above. In this case, when the 2 nd wafer W is mounted on the wafer stage (wafer holder) in step 244, the positional relationship between the transfer arm and the wafer stage is adjusted in consideration of the measurement result of step 248 with respect to the 1 st wafer W. If the determination in step 250 for the 2 nd wafer W is affirmative, the process proceeds to step 252.

In step 252, the alignment mark on the wafer W is detected by using the alignment system ALG, and the position information of the alignment mark is detected according to the detection result and the measurement value of the interferometer system 118 during the detection, so as to perform wafer alignment, for example, wafer alignment such as enhanced full wafer alignment (EGA).

Next, in step 254, based on the positional information of the plurality of shot areas on the wafer W obtained as a result of the above-described wafer alignment, the measurement result of the latest alignment system ALG baseline, and the like, the inter-shot movement operation of the wafer stage WST to the scanning start position (acceleration start position) on the wafer W for exposing each shot area, and the scanning exposure operation for transferring the pattern formed on the reticle R to each shot area by the scanning exposure method are repeated, thereby exposing the plurality of shot areas on the wafer W by the step-and-scan method. In addition, during this exposure, water is continuously filled just below the front lens 91 of the projection optical system PL.

In the next step 256, it is determined whether all wafers in a batch have been exposed. If the determination is negative, the process proceeds to step 262, and after the wafer W having been exposed by the wafer holder WH held on the wafer table WTB is exchanged with a new wafer, the process proceeds to step 252, and then the loop process of step 252 → 254 → 256 → 262 is repeated until the determination of step 256 is affirmative.

On the other hand, if the determination at step 256 is affirmative, the process proceeds to step 258.

Next, in step 258, it is determined whether or not the exchange timing of the liquid repellent plate has come, for example, with reference to the irradiation history of the illumination light IL. Here, in the present embodiment, the relationship between the degradation of the water repellant coating on the surface of the liquid repellent plate 50 and the integrated energy irradiated on the surface of the liquid repellent plate 50 is determined by experiments in advance, and the arrival of the exchange timing of the liquid repellent plate 50 is determined before the degradation of the water repellant coating from the relationship and the irradiation history of the illumination light IL.

Then, the process proceeds to step 264, where the process proceeds to the next batch.

Accordingly, a series of processes from the exchange of the liquid repellent plates to the next exchange is performed.

As is clear from the above description, in the present embodiment, main controller 20 can realize an outer peripheral edge position acquisition device, an inner peripheral edge acquisition device, a determination device shape calculation device, an object outer peripheral edge position acquisition device, an interval measurement device, a stage control device, and a control device, in order to more accurately use the CPU inside main controller 20 and software executed by the CPU. However, it is needless to say that at least a part of the constituent elements realized by the software may be constituted by hardware.

As described above, according to exposure apparatus 100 of the present embodiment, the position of wafer table WTB (wafer stage WST) detachably mounted on liquid-repellent plate 50 is measured by interferometer system 118 using main controller 20 functioning as an outer peripheral edge position acquisition device, a part of liquid-repellent plate 50 is detected by alignment system ALG, and position information of the outer peripheral edge of liquid-repellent plate 50 is acquired based on the detection result and the measurement result of corresponding interferometer system 118 (steps 204 to 210). Therefore, as in the present embodiment, even if there is no mark or the like for position measurement on wafer table WTB (wafer stage WST), the position of liquid repellent plate 50, that is, the position of wafer table WTB (wafer stage WST), can be managed on the moving coordinate system (stage coordinate system) defined by the interferometer system based on the position data of the outer peripheral edge of liquid repellent plate 50.

Further, as in the present embodiment, when the outer periphery of liquid repellent plate 50 extends outward from wafer table WTB, the position of wafer table WTB (wafer stage WST) can be controlled so as to avoid collision of the outer peripheral edge of liquid repellent plate 50 with another member (e.g., measurement stage MST).

In addition, even when a mark for position measurement is provided on wafer table WTB (wafer stage WST) or liquid repellent plate 50, or even when the outer periphery of liquid repellent plate 50 does not protrude outward from wafer table WTB, it is possible to obtain position information of the outer peripheral edge of liquid repellent plate 50, as described above.

Further, according to the exposure apparatus 100 of the present embodiment, the main controller 20 functioning as the inner peripheral edge position acquisition device measures the position of the wafer table WTB using the interferometer system 118, detects a part of the liquid-repellent plate 50 using the alignment system ALG, and acquires the position information of the inner peripheral edge of the opening 50a of the liquid-repellent plate 50 based on the detection result and the measurement result of the corresponding interferometer system 118 (step 222). Therefore, the position, shape, etc. of the opening 50a can be calculated based on the position information of the inner peripheral edge (see steps 224 and 226).

In the exposure apparatus 100 of the present embodiment, when the roundness is smaller than the 2 nd threshold value, for example, as the main controller 20 functioning as the stage controller, the wafer W is loaded on the wafer holder WH in the opening 50a of the liquid-repellent plate 50 on the wafer stage WST (wafer table WTB) via the transport system 72 based on the position information of the peripheral edge in the opening 50a of the liquid-repellent plate 50 (step 232). Therefore, it is easier to load wafer W into opening 50a of liquid repellent plate 50 on wafer stage WST, compared to the case where information about the inner peripheral edge of opening 50a of liquid repellent plate 50 is not taken into consideration.

In the exposure apparatus 100 of the present embodiment, when the positional relationship between the inner peripheral edge of the opening 50a and the object (tool wafer W1 or wafer W) in the opening 50a is acquired (see step 240), and the main controller 20 functioning as the stage controller controls at least one of the wafer table WTB and the transfer arm 70 of the transfer system 72 in consideration of the information of the positional relationship when the wafer W is transferred to the wafer table WTB by the transfer system 72, and adjusts the positions of the transfer arm 70 and the wafer table to load the wafer (see step 244). Therefore, based on the obtained positional relationship, the wafer can be loaded in the recess 140 of the wafer table WTB (that is, inside the inner peripheral edge of the opening 50a of the liquid repellent plate 50) in a desired positional relationship. In this case, the wafer W is loaded on the wafer holder WH inside the inner peripheral edge of the opening 50a of the liquid-repellent plate 50 above the wafer table WTB (inside the recess on the wafer table WTB) so that the outer peripheral edge of the wafer W is prevented from contacting the inner peripheral edge of the opening 50a of the liquid-repellent plate 50 (inside the recess on the wafer table WTB) and the interval between the outer peripheral edge of the wafer W and the inner peripheral edge of the opening 50a is smaller than a predetermined value (for example, 0.3 mm).

In the operations described with reference to fig. 11 and 12, the 1 st threshold and the 2 nd threshold are set for the shape (roundness) of the opening 50a, and the tool wafer W1 is loaded on the wafer holder, but it is also possible to determine whether or not to load the tool wafer W1 using only one threshold. In this case, the tool wafer W1 may be a wafer having a smaller diameter than the wafer W to be exposed, or may be a wafer having a diameter substantially the same as the wafer W to be exposed.

In the operation described with reference to fig. 11 and 12, the tool wafer W1 is loaded on the wafer holder after the shape information of the opening 50a is acquired, but the acquisition of the shape information may be omitted. In this case, the tool wafer W1 may be a wafer having a smaller diameter than the wafer W to be exposed, or may be a wafer having a diameter substantially the same as the wafer W to be exposed.

In the operation described in fig. 11 and 12, the tool wafer W1 is mounted on the wafer holder after the position information and shape information of the opening 50a are obtained, but the position information and shape information of the opening 50a may be omitted, and the position information and positional relationship (including the interval) between the inner peripheral edge of the opening and the outer peripheral edge of the tool wafer W1 may be obtained after the tool wafer W1 is mounted on the wafer holder. Of course, if necessary, the shape information of the opening 50a can also be obtained. In this case, the tool wafer W1 is preferably a wafer having a smaller diameter than the wafer W to be exposed, but may be a wafer having substantially the same diameter as the wafer W to be exposed.

In the operations described with reference to fig. 11 and 12, the positional relationship (gap) between the inner peripheral edge of the opening 50a and the wafer W is measured when the wafer W as the 1 st substrate to be exposed is placed on the wafer holder, but the measurement operation may be omitted when the wafer W as the substrate to be exposed is placed at a predetermined position in the opening 50a based on the information obtained by using the tool wafer W1 (steps 246, 248, 250).

In the operation described in fig. 11 and 12, it is determined whether or not to exchange the liquid ejecting plate 50 after the completion of one batch of exposure processing in step 258, but step 258 may be omitted, and the determination may be made at every predetermined time, and the determination as to whether or not to exchange may not be made, or the liquid ejecting plate may be exchanged after the elapse of the predetermined time.

Next, according to the exposure apparatus 100, as described above, illumination light is irradiated onto the wafer W placed inside the inner peripheral edge of the opening 50a of the liquid deflector 50 above the wafer table WTB (inside the recess on the upper surface of the wafer table WTB) to perform exposure (step 254). Therefore, during the exposure operation, the liquid (water) Lq is prevented from leaking from between the wafer W and the liquid-repellent plate 50, and by performing the exposure with high resolution and a focal depth larger than that in the air by the immersion exposure, the pattern of the reticle R can be transferred onto the wafer with high accuracy, and for example, the transfer of a fine pattern of about 45 to 100nm can be realized using ArF excimer laser as the device specification.

According to exposure apparatus 100 of the present embodiment, since the minimum components necessary for exposing wafer stage WST (wafer table WTB) are provided, for example, only a wafer holder and the like can be provided, wafer stage WST can be made small and light, the size of a drive mechanism (motor) for driving the wafer stage and the amount of heat generated by the motor can be reduced, and thermal deformation of wafer stage WST and a decrease in exposure accuracy can be suppressed as much as possible.

In addition, the above embodiment has been described with respect to the case where a plurality of measurement points are set on the outer peripheral edge of the liquid repellent plate 50 to obtain position information of the plurality of measurement points, but the present invention is not limited to this, and for example, a known mark may be formed at a position inside the position of the outer peripheral edge on the upper surface of the liquid repellent plate 50 in a positional relationship with the outer peripheral edge, for example, a linear mark parallel to the outer peripheral edge may be formed at a position at a predetermined distance (assumed as D) from the outer peripheral edge, at least one measurement point may be set on the mark, the position information of the measurement point may be measured, and the position of the outer peripheral edge may be obtained based on the measurement result and the distance. As shown in fig. 18, since a curved surface (or inclined surface) having a width d and a height h is often present near the edge of the liquid-repellent plate 50, and the height h is about 0.1mm, the focal depth of the alignment system ALG is small, and the edge image is blurred. In this case, the linear mark may be provided at a position D > D, and the alignment system ALG may image the linear mark. Of course, the mark is not limited to the above-described line shape, and the positional relationship with the peripheral edge is known regardless of the shape.

Similarly, a mark having a known positional relationship with the inner peripheral edge of the opening 50a of the liquid-repellent plate 50 may be formed in advance, and positional information of at least one measurement point on the mark may be acquired. For example, a circular line concentric with the opening 50a may be formed as a mark outside the inner peripheral edge of the opening 50a by a predetermined distance.

When the position information such as the peripheral edge of the liquid repellent plate 50 is detected, it is preferable to use a focus detection system having an alignment system ALG, but when the detection beam of the focus detection system having the alignment system ALG deviates from the liquid repellent plate 50, the detection beam is irradiated to the position on the surface of the liquid repellent plate 50, and after focusing is performed, it is preferable to perform a focus displacement operation for positioning the measurement point in the imaging field of view of the alignment system ALG while maintaining the focus state.

In the above embodiment, the case where the peripheral edge of the liquid deflector 50, the inner peripheral edge of the opening 50a, the tool wafer W1, or the peripheral edge of the wafer W is photographed by using the alignment system ALG constituted by the sensors of the FIA system, and the position information of each measurement point is obtained by the image processing method using the photographed result is described. In the case of the FIA system, although it is needless to say that reflected light from the object can be detected by the down-light illumination, the edge of the liquid repellent plate 50 may be illuminated from below, and transmitted light may be detected above the liquid repellent plate 50.

In the above embodiment, at least one of the exchange operation of the liquid deflector 50 and the various measurements of the liquid deflector 50 may be performed in a state where the liquid Lq is absent on the image plane side of the projection optical system PL, or may be performed in a state where the liquid Lq is held between the measurement table MTB and the projection optical system PL. When the liquid Lq is continuously held between the measurement table MTB and the projection optical system PL, the wetting state of the front end surface of the projection optical system PL can be maintained, and therefore, not only can the occurrence of water marks or the like be prevented, but also the work of collecting and resupplying the entire liquid Lq can be omitted.

In the above embodiment, wafer table WTB constitutes the 1 st stage (and the movable body) (a board on which position information of the outer periphery thereof is detected is detachably mounted), and measurement stage MST is described as constituting the 2 nd stage, but the present invention is not limited thereto, and measurement stage MTB may constitute the 1 st stage (and the movable body). That is, the position information of the outer peripheral edge of the plate member detachably mounted on the measuring table MTB can be obtained. In this case, the movement of the measuring table MTB can be controlled based on the position information of the outer peripheral edge thereof. In this case, at least one of the plate exchanging operation of the measurement table MTB and the various measurements of the plate may be performed in a state where the liquid Lq is not present on the image plane side of the projection optical system PL.

In addition, the liquid Lq may be held between the measurement stage MTB and the projection optical system PL.

That is, when the liquid-repellent plate 50 is exchanged on the wafer table WTB side, as shown in fig. 19(a), the liquid Lq is positioned on the measurement table MTB, and the position of the measurement table MTB is controlled. Next, after the exchange of the liquid repellent plate 50 is completed, as shown in fig. 19(B), the peripheral edge of the liquid repellent plate 50 on the measurement stage MTB (measurement stage MST) side (+ Y side) is measured using the alignment system ALG. With this, wafer table WTB (wafer stage WST) can be brought close to measurement stage MTB (measurement stage MST).

Next, as shown in fig. 19(C) and 19(D), the-X side peripheral edge of the liquid repellent plate 50 and the + X side peripheral edge of the liquid repellent plate 50 are measured in this order by using the alignment system ALG.

Based on the thus measured 3-position information of the outer peripheral edge of liquid repellent plate 50 or the position information of liquid repellent plate 50 obtained therefrom, the position of wafer table WTB (wafer stage WST) is thereafter managed by main controller 20.

After the positional information of the outer peripheral edge of liquid repellent plate 50 is measured, for example, both stages WST and MST are moved integrally while (liquid repellent plate 50 of) wafer table WTB is kept in contact with (or close to) measurement table MTB, and as shown in fig. 20(a), the inner peripheral edge on the + Y side of opening 50a of liquid repellent plate 50 is measured using alignment system ALG. Next, while (the liquid-repellent plate 50 of) the wafer table WTB is kept in contact with (or close to) the measurement table MTB, the two stages WST and MST are sequentially moved integrally, and as shown in fig. 20(B) and 20(C), the-X inner peripheral edge and the + X inner peripheral edge of the opening 50a of the liquid-repellent plate 50 are sequentially measured by using the alignment system ALG. In this case, since the wafer is not mounted on the wafer table WTB, the liquid Lq cannot be positioned at the portion where the wafer is mounted, and therefore, as shown in fig. 20(a) to 20(C), the inner peripheral edge can be measured, and based on the measurement result, the wafer can be mounted on the wafer holder WH in the same manner as in the above-described embodiment.

As described above, by performing the exchange operation of the liquid-repellent plate 50 of the wafer table WTB or the measurement operation of the outer peripheral edge of the liquid-repellent plate 50 and the inner peripheral edge of the opening 50a of the liquid-repellent plate 50 while maintaining the liquid Lq between the measurement stage MTB and the projection optical system PL, the liquid recovery operation and the liquid supply operation are not required, the time required for these operations is not required, and the throughput of the partial exposure step can be improved.

Further, as described above, the outer peripheral edge of liquid repellent plate 50 and the inner peripheral edge of opening 50a are measured, and after the wafer is mounted on wafer holder WH, the range of movement is expanded in a state where liquid repellent plate 50 of wafer stage WST (wafer table WTB) on which the wafer is mounted is brought into contact with measurement stage WST. That is, the liquid Lq can be disposed over the entire surface of the wafer stage WST. Accordingly, the measurement can be performed again by using the measurement method described in the flowcharts of fig. 7, 11, and 12 according to the above embodiment. This enables measurement with higher accuracy.

In the above embodiment, the measurement points of the position information are set at a plurality of pairs symmetrical to the center on the outer peripheral edge of the liquid repellent plate 50, the inner peripheral edge of the opening 50a, the tool wafer W1, or the outer peripheral edge of the wafer W, but the measurement accuracy is merely expected to be improved by the averaging effect when calculating the position of each center point, for example, but the present invention is not limited thereto.

In the above embodiment, the liquid-repellent plate 50 is described as being substantially square and the opening 50a as being circular, but the plate may be circular, polygonal, or other shapes. Preferably the openings also follow the shape of the object to be treated. For example, when a liquid crystal display element or the like is used as the object to be processed, it is preferable that the opening is formed in a rectangular shape according to the object to be processed (the shape of the glass plate).

In the above embodiment, the plate 50 is described as being attachable to and detachable from the wafer table WTB, but the plate 50 may be integrally formed with the wafer table WTB. In this case, for example, as shown in fig. 11 or 13, the position information of the inner peripheral edge of the recess formed for loading the wafer W on the wafer table WTB can be detected.

In the above-described embodiment, the series of operations including the measurement of the positional information of the outer peripheral edge of the plate described with reference to fig. 7 and the series of operations including the measurement of the positional information of the inner peripheral edge of the opening of the plate described with reference to fig. 11 are not necessarily performed together, and either one or both of them may be performed.

In addition, although the above embodiment describes the case where the present invention is applied to a liquid immersion exposure apparatus, the application range of the present invention is not limited thereto, and the present invention can be applied to a general stepper of a non-liquid immersion type. In this case, a plate member having no liquid level formed on the surface thereof can be used instead of the liquid level plate.

In the above embodiment, the case where the stage device includes one wafer stage and one measurement stage has been described, but the present invention is not limited to this, and at least one wafer stage for holding a wafer may be provided without a measurement stage. In addition, in the case where a plurality of wafer stages are provided, at least one of the wafer stage that performs the work of exchanging the plate and the various work of measuring the plate may be performed in a state where the liquid Lq is not present on the image plane side of the projection optical system PL, or the other wafer stage may be disposed below (on the image plane side) the projection optical system PL so as to be held between the projection optical system and the other wafer stage.

In the above embodiment, the case where the leveling table 52 has 6 degrees of freedom and the measurement table MTB has 3 degrees of freedom has been described, but the present invention is not limited thereto, and the leveling table 52 may have 3 degrees of freedom and the measurement table MTB may have 3 degrees of freedom. Alternatively, the leveling table 52 may not be provided, and the measuring table MTB may have a 6-degree-of-freedom configuration.

In the above embodiment, ultrapure water (water) is used as the liquid, but the present invention is not limited thereto. As the liquid, a liquid which is chemically stable, has high transmittance of the illumination light IL, and is safe may be used, and for example, a halogen is an inert liquid. As the halogen, an inert liquid, for example, Fluorinert (trade name of 3M company in the United states) can be used. This halogen is also excellent as a point of the inert liquid in cooling effect. Further, as the liquid, a liquid which has a transmittance for the illumination light IL, has a refractive index as high as possible, and is suitable for projection opticsThe system or the photoresist coated on the wafer surface (such as, for example, fir oil). And, handle F₂In the case of a laser as the light source, Fenbulin oil (Fomblin) is preferably selected.

In the above embodiment, the recovered liquid may be reused, and in this case, it is preferable to provide a filter (for removing impurities from the recovered liquid) in advance in the liquid recovery device, the recovery pipe, or the like.

In the above embodiment, the optical element on the most image plane side of the projection optical system PL is used as the front lens, but the optical element is not limited to a lens, and may be an optical plate (such as a parallel plane plate) used for adjusting optical characteristics of the projection optical system PL, for example, aberration (spherical aberration and coma aberration), or may be simply a cover glass. The optical element on the most image plane side of the projection optical system PL (the front lens 91 in each of the embodiments described above) may contaminate the surface with the liquid (water in each of the embodiments described above) due to scattering particles generated from the resist, adhesion of impurities in the liquid, and the like when irradiated with the illumination light IL. Accordingly, the optical element can be fixed to the lowermost portion of the lens barrel 40 in a detachable (exchangeable) manner, and can be exchanged periodically.

In this case, if the optical element in contact with the liquid is a lens, the cost of the exchange element becomes high, and the time required for exchange becomes long, leading to an increase in maintenance cost (running cost) and a reduction in productivity. Therefore, the optical element in contact with the liquid can also be used as a parallel plane plate which is cheaper than the lens 91, for example.

The above embodiment describes a case where the present invention is applied to a scanning exposure apparatus such as a step-and-scan method, but the application range of the present invention is not limited to this. That is, the present invention is also applicable to an exposure apparatus of a step-and-stitch system, an exposure apparatus of a proximity system, or the like.

The use of the exposure apparatus is not limited to exposure apparatuses for semiconductor manufacturing, and for example, the apparatus can be widely applied to exposure apparatuses for liquid crystal, which transfer a liquid crystal display element pattern onto an angled glass plate, and exposure apparatuses for manufacturing organic EL, thin film magnetic heads, imaging elements (such as CCD), micromachines, DNA wafers, and the like. The present invention is applicable to an exposure apparatus for manufacturing a reticle or a mask used for manufacturing microdevices such as semiconductor devices, light exposure apparatus, RUV exposure apparatus, X-ray exposure apparatus, electron beam exposure apparatus, and the like, and transferring a circuit pattern to a silicon wafer or the like.

The light source of the exposure apparatus of the above embodiment is not limited to ArF excimer laser, but KrF excimer laser (output wavelength 248nm) and F can be used₂Laser (output wavelength 157nm), Ar₂Laser (output wavelength 126nm), Kr₂A pulsed laser light source such as a laser (output wavelength: 146nm), or an ultrahigh pressure mercury lamp that generates light such as g-line (wavelength: 436nm) or i-line (wavelength: 365 nm). Further, a harmonic generator of YAG laser or the like can be used. Alternatively, for example, a fiber amplifier doped with erbium (or both erbium and ytterbium) may be used to amplify a single wavelength laser in the infrared region or visible region oscillated from a DFB semiconductor laser or a fiber laser, and a nonlinear optical crystal may be used to convert the wavelength of the laser into a higher harmonic of ultraviolet light. The projection optical system may be a reduction system, or an equal magnification or enlargement system.

Further, although the above embodiment has been described with respect to an exposure apparatus using a light-transmitting mask (reticle) in which a predetermined light-shielding pattern (or phase pattern, or light-reducing pattern) is formed on a light-transmitting substrate, an exposure apparatus using an electronic mask (variable-shape mask) in which a transmission pattern, a reflection pattern, or a light-emitting pattern is formed based on electronic data of a pattern to be exposed, as disclosed in, for example, U.S. Pat. No. 6,778,257, may be applied instead of the reticle.

Further, as disclosed in international publication No. 2001/035168 pamphlet, the present invention is also applicable to an exposure apparatus (lithography system) for forming an equidistant line (linear space) pattern on a wafer W by forming interference fringes on the wafer W.

In addition, although the above-described embodiments have been described with respect to the case where the position measuring method, the loading method, and the like of the present invention are applied to the exposure apparatus, the present invention is not limited to this, and the position measuring method can be applied to the present invention if a plate having a predetermined shape is provided with a movable body detachably mounted on the movable body, and the measuring method, the loading method, and the like of the present invention can be applied to the case where the apparatus is provided with a movable body detachably mounted on a plate having an opening for a loading object.

In addition, the semiconductor device is manufactured through the steps including: a step of designing the function and performance of the device, a step of fabricating a reticle in accordance with the designing step, a step of fabricating a wafer from a silicon material, a photolithography step (the exposure apparatus of the above embodiment in which the pattern transfer characteristic is adjusted by the above-described adjustment method transfers the pattern formed on the mask onto the photosensitive object), a device assembling step (including a dicing step, a bonding step, a packaging step), and an inspection step. In this case, since the exposure apparatus and the exposure method according to the above-described embodiments are used in the photolithography step, high-precision exposure can be realized over a long period of time. Therefore, the productivity of the high-density microdevice having a fine pattern can be improved.

As described above, the position measuring method of the present invention is applied to position measurement of a plate member detachably mounted on a movable body. Also, the position control method of the present invention is suitable for measuring information on a plate in which an opening (for loading an object) is formed. The loading method of the present invention is suitable for loading an object on the moving object. The exposure method, exposure apparatus, and device manufacturing method of the present invention are suitable for manufacturing microdevices such as semiconductor devices.

Claims (62)

1. A measurement method for measuring information on a plate which is detachably mounted on a movable body and has an opening for placing an object, the measurement method comprising:

an obtaining step of detecting a part of the plate and obtaining position information of an inner peripheral edge of the opening based on a detection result,

the detection of a part of the plate is performed while measuring the position of the movable body by a position measuring system defining a coordinate system of the movable body, and position information of a plurality of positions of an inner peripheral edge of the opening is acquired based on a detection result and a measurement result of the position measuring system.

2. The measuring method according to claim 1, wherein the obtaining step is performed after the plate member is disassembled or exchanged.

3. The measuring method according to claim 2, wherein a plurality of positions of the plate member are detected in order to obtain the positional information of the inner peripheral edge.

4. The measuring method according to claim 1, further comprising a position calculating step of calculating a position of the opening based on position information of the inner peripheral edge.

5. The measuring method according to claim 1, further comprising a shape calculating step of calculating a shape of the opening based on the positional information of the inner peripheral edge.

6. The measuring method according to claim 5, wherein the opening is circular;

the shape calculating step calculates at least the roundness of the opening.

7. The measuring method according to claim 1, wherein the moving body has a reflecting surface; the position measurement system includes an interferometer system that measures a position of the movable body using a reflection surface of the movable body.

8. The measuring method according to claim 1, wherein at least one of the inner peripheral edge of the opening and the mark on the plate member whose positional relationship with the inner peripheral edge is known is detected in order to obtain positional information of the inner peripheral edge.

9. The measuring method according to claim 8, wherein the detection of at least one of the inner peripheral edge and the mark is performed at a plurality of positions including at least 2 positions substantially symmetrical with respect to the center of the opening.

10. A loading method for loading an object on a movable body on which a plate having an opening for loading the object is detachably mounted, characterized in that:

loading the object into the opening of the plate on the movable body based on the position information of the inner peripheral edge of the opening of the plate obtained by using the measuring method according to any one of claims 1 to 9.

11. A loading method according to claim 10, wherein a positional relationship between the object to be loaded and the movable body is adjusted based on the positional information of the inner peripheral edge.

12. The loading method according to claim 10, wherein the object is loaded in the opening of the plate on the movable body based on the positional information of the inner peripheral edge of the opening of the plate in such a manner that the outer peripheral edge of the object is prevented from contacting the inner peripheral edge of the opening and the interval between the outer peripheral edge of the object and the inner peripheral edge of the opening is made smaller than a predetermined value.

13. The loading method according to claim 12, wherein the object is conveyed to above the movable body;

setting the positional relationship between the object to be loaded and the movable body based on the positional information of the inner peripheral edge.

14. An exposure method for exposing an object, comprising the steps of:

loading the object into the opening of the plate on the movable body using the loading method according to claim 10; and

the object mounted on the movable body is irradiated with an exposure light beam.

15. The exposure method according to claim 14, wherein the object is exposed with the exposure beam through a projection optical system and a liquid, and is placed in the opening such that a surface of the object and a surface of the plate are substantially flush.

16. The exposure method according to claim 15, wherein the surface of the plate which is in contact with the liquid is a meniscus.

17. The exposure method according to claim 15, wherein a liquid immersion area is formed by the liquid on the movable body by carrying a part of the object placed in the opening;

the object is exposed through the liquid immersion area located at a portion thereof.

18. The exposure method according to claim 14, wherein the object is subjected to pre-alignment;

the object on which the pre-alignment has been performed is loaded on the moving body.

19. A method for manufacturing a device, comprising: a photolithography step using the exposure method according to claim 14.

20. A loading method for loading an object on a movable body, comprising:

obtaining position information of an inner peripheral edge of an opening formed on the movable body;

in order to load the object on the movable body and carry the object above the movable body into the opening, the positional relationship between the carried object and the movable body is adjusted according to the positional information of the inner peripheral edge of the opening.

21. A loading method according to claim 20, wherein the positional relationship between the object to be conveyed and the movable body is adjusted so that an outer peripheral edge of the object is prevented from contacting an inner peripheral edge of the opening and a distance between the outer peripheral edge of the object and the inner peripheral edge of the opening is made smaller than a predetermined value.

22. The loading method according to claim 21, wherein the upper surface of the movable body is located at substantially the same height as the surface of the object placed in the opening in the movable body.

23. An exposure method for exposing an object, comprising the steps of:

loading the object in an opening on the movable body using the loading method according to any one of claims 20 to 22; and

the object mounted on the movable body is irradiated with an exposure light beam.

24. A loading method for loading an object through a transport system in an exposure apparatus for exposing the object with an exposure beam through a projection optical system and a liquid, comprising:

detecting a part of a stage on which the object is placed in a recess disposed on a part of the upper surface thereof to obtain position information of an inner peripheral edge of the recess;

transporting the object by the transport system to a position above the stage disposed at an exchange position of the object separated from the projection optical system; and

the object is loaded on the stage based on the position information of the inner peripheral edge of the recess in such a manner that the object to be conveyed is loaded in the recess.

25. A loading method according to claim 24, wherein at least one of the carrying system and the stage is controlled based on the positional information of the inner peripheral edge of the recess to set the positional relationship between the object to be carried and the stage.

26. A loading method according to claim 25, wherein information on a center position or a shape of the recess is calculated based on position information of an inner peripheral edge of the recess.

27. A loading method according to claim 25, wherein the positional relationship between the object to be transported and the stage is set so that the object is loaded without contact with the upper surface of the stage and a gap formed between the surface of the object placed in the recess and the upper surface of the stage is smaller than a predetermined value.

28. The loading method according to claim 27, wherein the object is placed in the recess in such a manner that the gap is 0.3mm or less or the interval is substantially uniform.

29. A loading method according to claim 25, wherein the position information of the inner peripheral edge of the recess on the coordinate system is acquired by detecting a part of the stage by a detection device different from the position measurement system while measuring the position information of the stage by the position measurement system of the coordinate system defining the movement of the stage.

30. An exposure method for exposing an object with an exposure beam through a projection optical system and a liquid, comprising the steps of:

loading the object on the stage in such a manner that the object is placed in the concave portion of the stage using the loading method according to any one of claims 24 to 29;

moving the stage so that a liquid immersion area formed under the projection optical system by the liquid is located at a part of the object; and

the liquid passing through the projection optical system and the liquid immersion area exposes the object with the exposure beam.

31. The exposure method according to claim 30, wherein the object is placed in the concave portion with a gap formed between a surface thereof and an upper surface of the stage;

the stage moves so that the liquid immersion area on the upper side thereof crosses the gap.

32. The exposure method according to claim 31, wherein the object is placed in the concave portion such that a surface thereof is substantially flush with an upper surface of the stage.

33. The exposure method according to claim 31, wherein the liquid immersion area is maintained under the projection optical system by a stage different from the stage in a part of the detection operation of the stage.

34. The exposure method according to claim 33, wherein the different stage is capable of carrying an object to which the exposure light beam is exposed through the projection optical system and the liquid immersion area or at least one measurement member to which the exposure light beam is irradiated through the projection optical system and the liquid immersion area.

35. The exposure method according to claim 31, wherein the object is subjected to pre-alignment, and the object subjected to the pre-alignment is loaded on the stage.

36. A method for manufacturing a device, comprising: a photolithography step using the exposure method according to claim 30.

37. An exposure apparatus for irradiating an object with an exposure beam, comprising:

a carrier for carrying a plate having a predetermined shape and an opening, and for carrying the object in the opening;

a position measurement system that measures a position of the stage;

a detection device for detecting a part of the stage; and

and an acquisition device for detecting a part of the plate by the detection device while measuring the position of the stage by the position measurement system, and acquiring the position information of the inner periphery of the opening based on the detection result and the measurement result of the position measurement system.

38. The exposure apparatus according to claim 37, further comprising a determination device for determining a positional relationship between a coordinate system defined by the position measurement system and the opening based on the positional information of the inner peripheral edge.

39. The exposure apparatus according to claim 37, further comprising a shape calculation device for calculating the shape of the opening based on the position information of the inner peripheral edge.

40. The exposure apparatus according to claim 37, further comprising:

a conveying system for conveying the object to the carrying platform; and

and a control device for controlling at least one of the stage and the conveying system based on the position information of the inner peripheral edge in order to load the conveyed object on the stage.

41. The exposure apparatus according to claim 40, wherein the control device sets a positional relationship between the object and the stage based on the positional information of the inner peripheral edge in order to load the object on the stage such that the object is placed in the opening.

42. The exposure apparatus according to claim 41, wherein the plate member is detachably mounted on the stage;

the position information of the inner peripheral edge is obtained every time the plate is removed or exchanged.

43. The exposure apparatus according to claim 40, wherein the control device controls at least one of the stage and the carrying system so as to prevent an inner peripheral edge of the opening from contacting an outer peripheral edge of the object and to make a distance between the inner peripheral edge of the opening and the outer peripheral edge of the object smaller than a predetermined value.

44. The exposure apparatus according to claim 37, further comprising a liquid immersion mechanism for supplying a liquid onto the stage to form a liquid immersion area;

irradiating the object with the exposure light beam through the liquid supplied from the liquid immersion mechanism;

a liquid level is formed on the surface of the stage which is in contact with the liquid immersion area by using the plate.

45. The exposure apparatus according to claim 37, wherein a surface of an object placed in the opening on the stage is located at substantially the same height as a surface of a plate loaded on the stage.

46. The exposure apparatus according to claim 37, wherein the detection device is also used for detection of an alignment mark on the object.

47. An exposure apparatus for irradiating an object with an exposure beam, comprising:

a stage for placing the object;

a carrying system for carrying the object to a position above the stage disposed at the exchange position of the object;

a control device for controlling the carrying platform and the conveying system; and

an acquisition device for acquiring the position information of the inner periphery of the opening formed on the carrier;

the control device adjusts the position relation between the object to be transported and the carrier according to the position information of the inner periphery of the opening, so as to load the object transported by the transport system into the opening on the carrier.

48. The exposure apparatus according to claim 47, wherein a positional relationship between the object to be transported and the stage is adjusted in the loading such that an outer peripheral edge of the object does not contact an inner peripheral edge of the opening and a distance between the outer peripheral edge of the object and the inner peripheral edge of the opening is smaller than a predetermined value.

49. The exposure apparatus according to claim 48, wherein an upper face of the stage is located at substantially the same height as a surface of an object held by the stage in the opening.

50. An exposure apparatus for exposing an object with an exposure beam through a projection optical system and a liquid, comprising:

a stage on which the object is placed in a recess disposed in a part of the upper surface;

a local immersion member that forms an immersion area in a part of the object that is disposed to face the projection optical system on the stage by the liquid;

a transport system that transports the object to a position above the stage disposed at an exchange position of the object separated from the projection optical system;

a measuring device for detecting a part of the stage to obtain position information of the inner peripheral edge of the recess; and

and a control device for controlling at least one of the stage and the conveying system based on the positional information of the inner peripheral edge of the recess, so that the object conveyed to the upper side of the stage by the conveying system is loaded on the stage in such a manner that the object is loaded in the recess.

51. The exposure apparatus according to claim 50, wherein the control device sets a positional relationship between the object to be transported and the stage based on positional information of an inner peripheral edge of the recess.

52. The exposure apparatus according to claim 51, further comprising a position measurement system for measuring position information of the stage;

the measuring device is provided with a detecting device which detects a part of the carrying platform and is different from the position measuring system;

while the position information of the stage is measured by the position measuring system, a part of the stage is detected by the detecting device to obtain the position information of the inner peripheral edge of the recess on a coordinate system defined by the position measuring system.

53. The exposure apparatus according to claim 52, wherein the control device controls driving of the stage based on the position information of the stage measured by the position measurement system.

54. The exposure apparatus according to claim 53, wherein information on a center position or a shape of the concave portion is acquired by detecting a plurality of places of the stage by the measurement device.

55. The exposure apparatus according to claim 53, wherein the positional relationship between the object to be conveyed and the stage is set so that the object is loaded on the upper surface of the stage without contacting the object and a gap formed between the surface of the object placed in the recess and the upper surface of the stage is smaller than a predetermined value.

56. The exposure apparatus according to claim 55, wherein the object is placed in the concave portion in such a manner that the gap is 0.3mm or less or the interval is substantially uniform.

57. The exposure apparatus according to claim 53, wherein the object is placed in the concave portion so that a gap is formed between a surface of the object and an upper surface of the stage;

the stage moves so that the liquid immersion area on the upper side thereof crosses the gap.

58. The exposure apparatus according to claim 57, wherein the object is placed in the concave portion such that a surface thereof is substantially flush with an upper surface of the stage.

59. The exposure apparatus according to claim 57, further comprising a stage different from the stage;

during a detection operation of a part of the stage, the liquid immersion area is maintained under the projection optical system by the different stage.

60. The exposure apparatus according to claim 59, wherein the different stage is capable of carrying an object to which the exposure beam is exposed through the liquid passing through the projection optical system and the liquid immersion area, or at least one measurement member to which the exposure beam is irradiated through the liquid passing through the projection optical system and the liquid immersion area.

61. The exposure apparatus according to claim 57, wherein the conveyance system has a pre-alignment device of the object;

the object that has been pre-aligned by the pre-alignment means is loaded on the stage.

62. A device manufacturing method characterized by comprising a lithography step using the exposure apparatus according to any one of claims 37 to 61.