Patent Description:
Conventionally, in a lithography process to manufacture electronic devices (microdevices) such as a semiconductor device (an integrated circuit or the like) or a liquid crystal display device, mainly, a projection exposure apparatus of a step-and-repeat method (a so-called stepper), projection exposure apparatus of a step-and-scan method (a so-called scanning stepper (also called a scanner)) or the like is mainly used.

Substrates such as a wafer, a glass plate and the like subject to exposure that are used in these types of exposure apparatuses are gradually becoming larger (for example, in the case of a wafer, in every ten years). Although a <NUM>-mm
wafer which has a diameter of <NUM> is currently the mainstream, the coming of age of a <NUM> wafer which has a diameter of <NUM> looms near. When the transition to <NUM> wafers occurs, the number of dies (chips) output from a single wafer becomes double or more than the number of chips from the current <NUM> wafer, which contributes to reducing the cost.

However, because the thickness does not necessarily increase in proportion to the size of the wafer, the <NUM> wafer is extremely weak in intensity and rigidity when compared with the <NUM> wafer. Therefore, when focusing on a point such as a carriage of a wafer, it was considered that there was a risk of warping occurring in the wafer, which may negatively effect the exposure accuracy when a means method similar to the current <NUM> wafer was employed. Accordingly, as the carry-in method of the wafer, a proposal is made of a carry-in method or the like that can be employed even when the wafer is a <NUM> wafer in which the wafer is suctioned from above in a non-contact manner by a carrier member equipped with a Bernoulli chuck or the like to maintain the flatness degree (flatness) and performs carry-in onto a wafer holder (holding device) (for example, refer to <CIT> hereinafter PTL <NUM>).

However, in the case of employing the non-contact suction from above by the carrier member described above as a carry-in method of the wafer onto the wafer stage (wafer holder), there was a risk of positional deviation (rotation deviation) in a horizontal plane of the wafer being generated at an unacceptable level, to which correction based on measurement results was difficult to perform.

As a method for resolving the inconvenience due to suction in a non-contact manner from above by the wafer carrier member described above, a method can be considered in which while a wafer is suctioned in a non-contact manner suction from above by a Bernoulli chuck or the like, the wafer is also supported from below by a support section (for example, vertical-motion pins on a wafer stage). However, according to studies of the inventors, in the case of performing loading of the wafer onto the wafer stage in a non-contact suction from above the wafer and support from below, it became clear that warping that is not acceptable could occur even in the case of a <NUM> wafer. By investigating the cause of this warping of the wafer, the inventors reached a conclusion that the main factor is surplus-restraint which occurs due to the wafer being vertically restrained around the center of the wafer.

According to a first aspect of the present invention, there is provided a carrier system as recited in claim <NUM> below.

In some embodiments, the suction force with respect to the object generated by each of the plurality of suction members, can be made different according to, for example, the position on the base member of each suction member. Therefore, for example, in the case of performing support of the object from below by the support section and suction in a non-contact manner from above of the object by this suction device, it becomes possible to make the suction force generated by the suction members placed at a part facing the support section of the base member be weaker than the suction force generated by the suction members placed at a part which does not face the support section of the base member.

According to a second aspect of the present invention, there is provided an exposure apparatus as recited in claim <NUM> below.

According to a third aspect of the present invention, there is provided the use of the exposure apparatus in a device manufacturing method as recited in claim <NUM> below.

According to a fourth aspect of the present invention, there is provided a carry-in method as recited in claim <NUM>.

The dependent claims provide particular embodiments of each respective aspect.

An embodiment will be described below, based on <FIG>.

<FIG> schematically shows a structure of an exposure apparatus <NUM> related to an embodiment. This exposure apparatus <NUM> is a projection exposure apparatus of a step-and-scan method, or a so-called scanner. As it will be described later on, a projection optical system PL is arranged in the present embodiment, and in the description below, a direction parallel to an optical axis AX of this projection optical system PL will be described as a Z-axis direction, a direction within a plane orthogonal to the Z-axis direction in which a reticle R and a wafer W are relatively scanned will be described as the Y-axis direction, a direction orthogonal to the Z-axis and the Y-axis will be described as an X-axis direction, and rotational (inclination) direction around the X-axis, the Y-axis, and the Z-axis will be described as a θx direction, a θy direction, and a θz direction.

Exposure apparatus <NUM> is equipped with an illumination system <NUM>, a reticle stage RST which holds reticle (mask) R, projection optical system PL, a wafer stage WST which holds wafer W, a carry-in unit <NUM> which structures a wafer carrier system <NUM> (refer to <FIG>) along with a carry-out unit which is not shown and a vertical-motion pin which will be described later on, and a control system or the like of these parts.

Illumination system <NUM>, as is disclosed in, for example, <CIT> and the like, includes a light source, an illuminance equalizing optical system including an optical integrator and the like, and an illumination optical system that has a reticle blind and the like (none of which are shown). Illumination system <NUM> illuminates a slit-shaped illumination area IAR set (limited) on reticle R by the reticle blind (also called a masking system) by an illumination light (exposure light) IL, with a substantially uniform illuminance. In this case, as illumination light IL, for example, an ArF excimer laser beam (wavelength <NUM>) is 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>) is fixed, for example, by vacuum chucking. Reticle stage RST, for example, is finely drivable within the XY plane by a reticle stage driving system <NUM> (not shown in <FIG>, refer to <FIG>) including a linear motor, a planar motor or the like, and is also drivable in a scanning direction (the Y-axis direction which is the lateral direction of the page surface in <FIG>) at a predetermined scanning speed.

Position information (including rotation information in the θz direction) of reticle stage RST in the XY plane is constantly detected, for example, by a reticle laser interferometer (hereinafter, referred to as a "reticle interferometer") <NUM>, via a movable mirror <NUM> (actually, a Y movable mirror (or a retroreflector) having a reflection surface orthogonal to the Y-axis direction and an X movable mirror having a reflection surface orthogonal to the X-axis direction are provided) fixed to reticle stage RST, at a resolution of, for example, around <NUM>.

Measurement values of reticle interferometer <NUM> are sent to a main controller <NUM> (not shown in <FIG>, refer to <FIG>). Main controller <NUM> drives reticle stage RST via reticle stage driving system <NUM> (refer to <FIG>), based on the position information of reticle stage RST. Incidentally, in the present embodiment, position information of reticle stage RST in the XY plane can be detected using an encoder, instead of the reticle interferometer described above.

Projection optical system PL is placed below reticle stage RST in <FIG>. Projection optical system PL is mounted on a main frame BD supported horizontally by a support member which is not shown. Used as projection optical system PL, for example, is a dioptric system consisting of a plurality of optical elements (lens elements) arranged along optical axis AX, which is parallel to the Z-axis. Projection optical system PL, for example, is double telecentric, and has a predetermined projection magnification (for example, <NUM>/<NUM> times, <NUM>/<NUM> times or <NUM>/<NUM> times). Therefore, when illumination area IAR on reticle R is illuminated by illumination light IL from illumination system <NUM>, a reduced image of the circuit pattern of reticle R (a reduced image of a part of the circuit pattern) within illumination area IAR is formed in an area (hereinafter, also called an exposure area) IA conjugate to illumination area IAR on wafer W whose surface is coated with a resist (sensitive agent) and is placed on a second surface (image plane) side of projection optical system PL, via projection optical system PL, by illumination light IL having passed through reticle R placed so that its pattern surface substantially coincides with a first surface (object plane) of projection optical system PL. And, by reticle stage RST and wafer stage WST (to be more precise, fine movement stage WFS to be described later on which holds wafer W) being synchronously driven, scanning exposure of a shot area (divided area) on wafer W is performed, by reticle R being relatively moved in the scanning direction (Y-axis direction) with respect to illumination area IAR (illumination light IL) and wafer W being relatively moved in the scanning direction (Y-axis direction) with respect to exposure area IA (illumination light IL), and the pattern of reticle R is transferred onto the shot area. That is, in the present embodiment, the pattern of reticle R is generated on wafer W by illumination system <NUM> and projection optical system PL, and by the exposure of the sensitive layer (resist layer) on wafer W with illumination light IL the pattern is formed on wafer W.

Wafer stage WST, as is shown in <FIG>, is supported by levitation on base board <NUM>, via air bearings which will be described later on. Here, base board <NUM> is supported almost horizontally (parallel to the XY plane) on a floor F by a vibration-proof mechanism (omitted in drawings). Base board <NUM> consists of a member that has a flat plate-like outer shape. Further, inside base board <NUM>, a coil unit is housed, which includes a plurality of coils <NUM> placed in the shape of a matrix with the XY two-dimensional direction serving as a row direction and a column direction.

Wafer stage WST, as it can be seen from <FIG> and <FIG>, has a coarse movement stage WCS, and a fine movement stage WFS, which is supported in a non-contact state by coarse movement stage and is relatively movable with respect to coarse movement stage WCS. Here, wafer stage WST (coarse movement stage WCS) is driven in predetermined strokes in the X-axis direction and the Y-axis direction, and is also finely driven in the θz direction by a coarse movement stage driving system <NUM> (refer to <FIG>). Further, fine movement stage WFS is driven in directions of six degrees of freedom (the X-axis direction, the Y-axis direction, the Z-axis direction, the θx direction, the θy direction and the θz direction) by a fine movement stage driving system <NUM> (refer to <FIG>), with respect to coarse movement stage WCS.

Coarse movement stage WCS, as is shown in <FIG>, is equipped with a coarse movement slider section <NUM> having a rectangular plate-like shape whose length in the X-axis direction is slightly longer than the length in the Y-axis direction in a planar view (when viewed from the +Z direction) , a pair of side wall sections 92a, 92b, each having a rectangular plate-like shape with the longitudinal direction being the Y-axis direction, and being fixed on the upper surface of one end and the other end of coarse movement slider section <NUM> in the longitudinal direction in a state parallel to the YZ plane, and a pair of stator sections 93a, 93b fixed on the upper surface of side wall sections 92a, 92b, respectively, at the center in the Y-axis direction facing the inner side. Coarse movement stage WCS, as a whole, has a low height rectangular parallelepiped shape whose upper surface is open at the center in the X-axis direction and on both sides in the Y-axis direction. That is, in coarse movement stage WCS, a space section penetrating in the Y-axis direction is formed inside. Incidentally, side wall sections 92a, 92b can have almost the same length in the Y-axis direction as stator sections 93a, 93b. That is, side wall sections 92a, 92b may be provided only at the center in the Y-axis direction on the upper surface of coarse movement slider section <NUM>, at one end and the other end in the longitudinal direction.

At the bottom surface of coarse movement stage WCS, that is, at the bottom surface of coarse movement slider section <NUM>, a magnet unit corresponding to the coil unit placed inside base board <NUM> is provided, consisting of a plurality of permanent magnets <NUM> placed in the shape of a matrix with the XY two-dimensional directions serving as a row direction and the column direction. The magnet unit, along with the coil unit of base board <NUM>, structures coarse movement stage driving system <NUM> (refer to <FIG>) consisting of a planar motor of an electromagnetic force (Lorentz force) driving method whose details are disclosed, for example, in <CIT> and the like. The magnitude and direction of the electric current supplied to each coil <NUM> structuring the coil unit (refer to <FIG>) are controlled by main controller <NUM>.

At the bottom surface of coarse movement slider section <NUM>, a plurality of air bearings <NUM> is fixed around the magnet unit described above. Coarse movement stage WCS is supported by levitation by the plurality of air bearings <NUM>, via a predetermined gap (clearance, gap) above base board <NUM>, such as for example, a gap of about several µm, and is driven in the X-axis direction, the Y-axis direction and the θz direction by coarse movement stage driving system <NUM>.

Incidentally, coarse movement stage driving system <NUM> is not limited to the planar motor of the electromagnetic force (Lorentz force) driving method, and for example, a planar motor of a variable magneto-resistance driving method can also be used. Other than this, coarse movement stage driving system <NUM> can be structured by a magnetic levitation type planar motor, and the planar motor can drive coarse movement stage WCS in directions of six degrees of freedom. In this case, the air bearings will not have to be arranged at the bottom surface of coarse movement slider section <NUM>.

Each of the pair of stator sections 93a, 93b, for example, consists of a member having an outer shape that is a rectangular plate shape, and inside each member, coil units CUa, CUb consisting of a plurality of coils are housed. The magnitude and direction of the electric current supplied to each coil structuring coil units CUa, CUb is controlled by main controller <NUM>.

Fine movement stage WFS, as is shown in <FIG>, for example, is equipped with a main section <NUM> consisting of a low-height columnar member having an octagonal shape in a planar view, a pair of mover sections 82a, 82b each fixed to one end and the other end in the X-axis direction of a main section <NUM>, and a wafer table WTB consisting of a rectangular plate-shaped member when viewed from above, which is integrally fixed to the upper surface of main section <NUM>.

Main section <NUM> is preferably made of a material having a thermal expansion coefficient, which is the same or around the same level as that of wafer table WTB, and the material is preferably a material having a low thermal expansion coefficient. Here, although it is omitted in the drawing in <FIG>, at main section <NUM>, a plurality of (for example, three) vertical-motion pins <NUM> (refer to <FIG>) being vertically movable is provided, which are inserted into through holes which are not shown formed in wafer table WTB (and in a wafer holder which is not shown). At the upper surface of each of the three vertical-motion pins <NUM>, an exhaust opening <NUM> is formed for vacuum exhaust. Further, each of the three vertical-motion pins <NUM> has the lower end surface fixed to the upper surface of a platform member <NUM>. Each of the three vertical-motion pins <NUM> is placed at a position which is almost the vertex of an equilateral triangle in a planar view on the upper surface of platform member <NUM>. Exhaust opening <NUM> provided at each of the three vertical-motion pins <NUM> is connected to a vacuum pump (not shown), via an exhaust pipeline formed inside vertical-motion pin <NUM> (and platform member <NUM>) and a vacuum exhaust piping which is not shown. Platform member <NUM> is connected to a driving device <NUM>, via a shaft <NUM> fixed at the center of the lower surface. That is, the three vertical-motion pins <NUM> are driven in the vertical direction by driving device <NUM>, integrally with platform member <NUM>. In the present embodiment, platform member <NUM>, the three vertical-motion pins <NUM> and shaft <NUM> structure a wafer support section <NUM>, which can support from below a part of a center section area of the wafer lower surface. Here, displacement in the Z-axis direction from a reference position of the three vertical-motion pins <NUM> (wafer support section <NUM>) is detected by a displacement sensor <NUM> (not shown in <FIG>, refer to <FIG>), such as, for example, the encoder system provided at driving device <NUM>. Main controller <NUM>, based on measurement values of displacement sensor <NUM>, drives the three vertical-motion pins <NUM> (wafer support section <NUM>) in the vertical direction via driving device <NUM>.

Referring back to <FIG>, each of the pair of mover sections 82a, 82b has a housing whose YZ section is a rectangular frame shape, which is fixed, respectively, to a surface at one end and a surface at the other end in the X-axis direction of main section <NUM>. Hereinafter, for the sake of convenience, the housings will be described as housings 82a, 82b using the same reference signs as mover sections 82a, 82b.

Housing 82a has a hollow section whose YZ section is a rectangular shape elongate in the Y-axis direction, with the Y-axis direction dimension (length) and the Z-axis direction dimension (height) both slightly longer than stator section 93a. In the hollow section of housings 82a, 82b, the end on the -X side of stator section 93a of coarse movement stage WCS is inserted in a non-contact manner. Inside an upper wall section 82a<NUM> and a bottom wall section 82a<NUM> of housing 82a, magnet units MUa<NUM>, MUa<NUM> are provided.

Mover section 82b is structured in a similar manner, although the structure is symmetrical to mover section 82a. In the hollow section of housing (mover section) 82b, the end on the +X side of stator section 93b of coarse movement stage WCS is inserted in a non-contact manner. Inside an upper wall section 82b<NUM> and bottom wall section 82b<NUM> of housing 82b, magnet units MUb<NUM>, MUb<NUM> are provided, which are structured similarly to magnet units MUa<NUM>, MUa<NUM>.

Coil units CUa, CUb described above are housed, respectively, inside stator sections 93a and 93b so that the units face magnet units MUa<NUM>, MUa<NUM> and magnet units MUb<NUM>, MUb<NUM>.

The structure of magnet units MUa<NUM>, MUa<NUM> and magnet units MUb<NUM>, MUb<NUM>, and coil units CUa, CUb, is disclosed in detail, for example, in <CIT>, <CIT> and the like.

In the present embodiment, fine movement stage driving system <NUM> (refer to <FIG>) in which fine movement stage WFS is supported by levitation in a non-contact state with respect to coarse movement stage WCS and is also driven in a non-contact manner in directions of six degrees of freedom is structured similarly to the <CIT> and the <CIT> described above, including the pair of magnet units MUa<NUM>, MUa<NUM> that mover section 82a previously described has and coil unit CUa that stator section 93a has, and the pair of magnet units MUb<NUM>, MUb<NUM> that mover section 82b has and coil unit CUb that stator section 93b has.

Incidentally, in the case of using a magnetic levitation type planar motor as coarse movement stage driving system <NUM> (refer to <FIG>) , because fine movement stage WFS can be finely driven in the Z-axis direction, the θx direction and the θy direction integrally with coarse movement stage WCS by the planar motor, fine movement stage driving system <NUM> can be structured so that fine movement stage WFS is drivable in the X-axis direction, the Y-axis direction and the θz direction, or that is, in directions of three degrees of freedom in the XY plane. Other than this, for example, to each of the pair of side wall sections 92a, 92b of coarse movement stage WCS, a pair of electromagnets each can be provided facing the oblique side of the octagonal shape of fine movement stage WFS, and facing each electromagnet a magnetic body member can be provided at fine movement stage WFS. With this arrangement, since fine movement stage WFS can be driven in the XY plane by the magnetic force of the electromagnet, this allows a pair of Y-axis linear motors to be structured by mover sections 82a, 82b and stator sections 93a, 93b.

In the center on the upper surface of wafer table, wafer W is fixed by vacuum chucking or the like via the wafer holder which is not shown such as a pin chuck. Further, on wafer table WTB, a movable mirror <NUM> (illustrated as movable mirrors 27X, 27Y in <FIG>) which reflects the laser beam from a wafer laser interferometer (hereinafter referred to as a "wafer interferometer") <NUM> (refer to <FIG>) is fixed, and by wafer interferometer <NUM> fixed to main frame BD in a suspended state, position of wafer table WTB in the XY plane is constantly detected, for example, at a resolution of around <NUM> to <NUM>. Here, actually, as is shown in <FIG>, on wafer table WTB, movable mirror 27Y having a reflection surface orthogonal to the Y-axis direction which is the scanning direction and movable mirror 27X having a reflection surface orthogonal to the X-axis direction which is the non-scanning direction are provided, and wafer interferometer <NUM> is provided with one axis in the scanning direction and two axes in the non-scanning direction, however, in <FIG>, these are representatively shown as movable mirror <NUM> and wafer interferometer <NUM>. Position information (or velocity information) of wafer table WTB is sent to main controller <NUM>. Main controller <NUM> controls the movement of wafer table WTB in the XY plane, via coarse movement stage driving system <NUM> and fine movement stage driving system <NUM>, based on the position information (or velocity information). Incidentally, the position information of wafer table WTB in the XY plane can be detected using, for example, an encoder system in which a scale (diffractive grating) or a head is mounted on wafer table WTB, instead of wafer interferometer <NUM>. Further, in the present embodiment, while wafer stage WST was a coarse fine movement stage equipped with coarse movement stage WCS and fine movement stage WFS, the present invention is not limited to this, and the wafer stage may be structured by a single stage which is movable in directions of six degrees of freedom.

Carry-in unit <NUM> is a unit for holding the wafer before exposure above the loading position prior to loading the wafer onto wafer table WTB and for loading the wafer onto wafer table WTB. Further, the carry-out unit which is not shown is a unit for unloading the wafer after exposure from wafer table WTB.

Carry-in unit <NUM>, as is shown in <FIG>, is equipped with a chuck unit driving system <NUM> attached to main frame BD via an anti-vibration device <NUM>, a chuck unit <NUM> and the like. Anti-vibration device <NUM> is a device for suppressing or preventing vibration generated at the time of driving chuck unit <NUM> by chuck unit driving system <NUM> from travelling to main frame BD, that is, for vibrationally separating chuck unit <NUM> from main frame BD. Accordingly, chuck unit driving system <NUM> and chuck unit <NUM> can be provided at another member, which is physically separate from main frame BD.

Chuck unit <NUM>, as is shown in <FIG>, for example, is equipped with a plate member <NUM> of a predetermined thickness having a circular shape in a planar view, and a plurality of chuck members <NUM> fixed in a predetermined placement to the lower surface of plate member <NUM>. Here, plate member <NUM> may also function as a cool plate in which piping and the like are provided inside, and by liquid controlled to a predetermined temperature flowing in the piping, the wafer is controlled to a predetermined temperature.

In the present embodiment, as is shown in <FIG> which is a planar view of chuck unit <NUM> when viewed from the -Z direction, at the lower surface of plate member <NUM> lower surface, seven chuck members <NUM> are placed at the center section area including the center point and at the outer periphery in a stat surrounding these seven chuck members <NUM> , eleven chuck members <NUM> are placed. The six chuck members <NUM> that surround chuck member <NUM> positioned at the center point of the lower surface of plate member <NUM>, are provided at positions substantially facing vertical-motion pins <NUM> when wafer stage WST is positioned at the loading position.

Each chuck member <NUM> consists of a so-called Bernoulli chuck. Bernoulli chuck, as is well known, is a chuck which uses the Bernoulli effect so that the flow velocity of the fluid blowing out (for example, air) is locally increased to suction (hold in a non-contact manner) the target object. Here, Bernoulli effect is an effect in which the pressure of the fluid decreases when the flow velocity increases, and with the Bernoulli chuck, the suction state (hold/levitation state) is determined by the weight of the target object to be suctioned (held, fixed) , and the flow amount (flow velocity, pressure) of the fluid blown out from the chuck. That is, in the case the size of the target object is known, the size of the gap between the chuck and the target object to be held is determined according to the flow amount (flow velocity) of the fluid blown out from the chuck. In the present embodiment, chuck member <NUM> is used to suction wafer W, by blowing out gas from its gas flow holes (for example, a nozzle or a blowout port) and generating a flow of gas (gas flow) in the periphery of wafer W (refer to <FIG> ). The degree of the force of suction (that is, the flow velocity and the like of the gas blown out) can be appropriately adjusted, and by suctioning wafer W with chuck member <NUM> and performing suction hold of the wafer, movement in the Z-axis direction, the θx direction and the θy direction can be restricted.

Further, with the plurality of chuck members <NUM>, flow velocity of the gas and the like blown out from each member is controlled by main controller <NUM>, via a first adjustment device 125a or a second adjustment device 125b (refer to <FIG> ). This allows the suction force (adsorption force) of each chuck member <NUM> to be set to any value. In the present embodiment, the suction force of each chuck member <NUM> is controlled, via the first adjustment device 125a or the second adjustment device 125b (refer to <FIG> ) in groups. The first adjustment device 125a has a first fluid supply device which is not shown connected to the seven chuck members <NUM> placed at the center section area of the plate member <NUM> lower surface, and adjusts the suction force of the seven chuck members <NUM> (adjusts the flow velocity of the fluid (gas, for example, air) blown out from chuck member <NUM>). Further, the second adjustment device 125b has a second fluid supply device which is not shown connected to the eleven chuck members <NUM> placed in the area excluding the center section area (that is, the outer circumference section) of the plate member <NUM> lower surface, and adjusts the suction force of the eleven chuck members <NUM>. That is, in the present embodiment, a gas supply device <NUM> including the first adjustment device 125a and the second adjustment device 125b is structured, which supplies fluid (gas, for example, air) to the plurality of (in this case, <NUM>) chuck members <NUM>.

<FIG> shows chuck members <NUM> whose suction force is adjusted by the first adjustment device 125a and chuck members <NUM> whose suction force is adjusted by the second adjustment device 125b, classified by color. Incidentally, in the present embodiment, while the suction force of each chuck member is made adjustable by performing blowout of the fluid (gas) at a different flow velocity as a state different from each other in the plurality of chuck members, the embodiment is not limited to this. For example, the pressure of the fluid (gas) may be changed, or the flow amount may be changed. Further, a structure may also be employed in which the plurality of chuck members <NUM> are not grouped and the suction forces can be individually adjusted.

Chuck unit <NUM> is drivable in predetermined strokes in the Z-axis direction (in between a first position where wafer W carried in by a carrier arm <NUM> (refer to <FIG>) which is described later is suctioned and a second position where the suctioned wafer W is mounted on wafer table WTB) , by chuck unit driving system <NUM> (refer to <FIG>). Chuck unit driving system <NUM> is controlled by main controller <NUM> (refer to <FIG>).

Referring back to <FIG>, on the -Y side of projection optical system PL, an off-axis alignment detection system <NUM> is provided. As alignment detection system <NUM>, for example, an FIA (Field Image Alignment) system alignment sensor of an image processing method is used, which irradiates a broadband detection beam that is not sensitive to the resist on wafer W on the subject mark, picks up an image of the subject mark formed on the light-receiving plane by the reflected light from the subject mark and an index image not shown using an imaging element (CCD) or the like, and outputs the imaging signals. The imaging results of this alignment detection system <NUM> are sent to main controller <NUM>.

Although it is not shown in <FIG>, above reticle R, a pair of reticle alignment detection systems <NUM> (refer to <FIG>) of a TTR (Through The Reticle) method is placed that uses an exposure wavelength to simultaneously observe a pair of reticle alignment marks on reticle R and an image via projection optical system PL of a pair of first reference marks on a reference mark plate which is not shown on wafer table WTB corresponding to the reticle alignment marks. Detection signals of the pair of reticle alignment detection systems <NUM> are supplied to main controller <NUM>.

Other than this, in exposure apparatus <NUM>, a multi-point focal point detection system <NUM> (refer to <FIG>) is provided, consisting of an irradiation system and a light-receiving system which are placed with alignment detection system <NUM> in between, and being structured in a similar manner as the system disclosed in, for example, <CIT> and the like.

<FIG> shows a block diagram illustrating an input/output relation of control main controller <NUM>, which mainly structures the control system of exposure apparatus <NUM> and has overall control over each section. Main controller <NUM> includes a work station (or a microcomputer) or the like, and has overall control over each section of exposure apparatus <NUM>.

In exposure apparatus <NUM> related to the present embodiment structured in the manner described above, first of all, reticle loading is performed by a reticle loader under the control of main controller <NUM>. Next, by main controller <NUM>, preparatory operations such as base line measurement of alignment detection system <NUM> are performed according to a predetermined procedure, using the pair of reticle alignment detection systems <NUM> (refer to <FIG>), the reference mark plate (not shown) on wafer stage WST, and alignment detection system <NUM> (refer to <FIG> and <FIG>) and the like. Loading of the wafer is performed after these preparatory operations.

Now, the procedure of loading of wafer W will be described based on <FIG>. As a premise, chuck unit driving system <NUM> is to be driven by main controller <NUM>, and chuck unit <NUM> is to be moved to a position (waiting position) at a predetermined height within the stroke range and to be waiting at this position.

In this state, first of all, as is shown in <FIG>, carrier arm <NUM> holding wafer W under the control of main controller <NUM> is moved to a position under chuck unit <NUM>. That is, wafer W is carried to a position below chuck unit <NUM> by carrier arm <NUM>. Next, as is shown by the outlined arrow in <FIG>, carrier arm <NUM> holding wafer W moves upward by a predetermined amount. On this operation, a high-pressure air flow is made to blow out from all the chuck members <NUM> of chuck unit <NUM>, via each gas flow hole.

Then, when carrier arm <NUM> is moved upward by a predetermined amount, as is shown in <FIG>, the upper surface of wafer W is suctioned in a non-contact manner by all the chuck members <NUM> of chuck unit <NUM>. Next, main controller <NUM> withdraws carrier arm <NUM> from under wafer W, after separating carrier arm <NUM> and wafer W. By this operation, wafer W moves to a state suctioned in a non-contact manner by chuck unit <NUM> located at a predetermined height position (waiting position) at the loading position. On this operation, while wafer W is in a state held by chuck unit <NUM> where its movement is restricted in the Z-axis direction, the θx direction, and the θy direction by the suction of chuck unit <NUM>, another member for holding wafer W may be prepared so that chuck unit <NUM> provides only the suction force (a force which can perform suction but not holding) to wafer W.

In this state, main controller <NUM> drives wafer stage WST via coarse movement stage driving system <NUM> (refer to <FIG>) to the position under wafer W held by chuck unit <NUM>. <FIG> shows wafer table WTB in the state after this movement of wafer stage WST.

Next, main controller <NUM>, as is shown in <FIG>, drives the three vertical-motion pins <NUM> (wafer support section <NUM>) on wafer stage WST (refer to <FIG>) upward, via driving device <NUM>. Then, when the three vertical-motion pins <NUM> come into contact with the lower surface of wafer W suctioned by chuck unit <NUM>, main controller <NUM> stops the upward drive of wafer support section <NUM>. Here, the Z position of wafer W suctioned by chuck unit <NUM> located at the waiting position can be obtained accurately to some extent. Accordingly, by driving wafer support section <NUM> by a predetermined amount from the reference position based on the measurement results of displacement sensor <NUM>, main controller <NUM> can make the three vertical-motion pins <NUM> come into contact with the lower surface of wafer W suctioned by chuck unit <NUM>. However, the arrangement is not limited to this, and it can be set in advance so that the three vertical-motion pins <NUM> come into contact with the lower surface of wafer W suctioned by chuck unit <NUM> at the upper limit of the movement position of wafer support section <NUM> (the three vertical-motion pins <NUM>).

Then, main controller <NUM> operates a vacuum pump which is not shown, and begins the vacuum chucking with respect to the wafer W lower surface by the three vertical-motion pins <NUM>. Incidentally, suction (holding) of wafer W by chuck member <NUM> is still being continued in this state. Movement of wafer W is restricted by the suction by chuck member <NUM> and a frictional force by the support from below of vertical-motion pins <NUM>, in directions of six degrees of freedom.

When wafer W is supported (suction hold is performed) by the three vertical-motion pins <NUM>, as is shown in <FIG>, main controller <NUM> releases the suction of wafer W by the seven chuck members <NUM> by stopping the outflow of the high-pressure air flow from the seven chuck members <NUM> at the center section area, via the first adjustment device 125a (refer to <FIG>). This is because when suction hold (support) by the three vertical-motion pins <NUM> from below and suction by chuck unit <NUM> from above is performed with respect to wafer W as is shown in <FIG>, partial surplus-restraint may occur in wafer W. When a downward synchronous drive of chuck unit <NUM> and wafer support section <NUM> (the three vertical-motion pins <NUM>) to load wafer W onto wafer table WTB is performed in the manner described below in this partially surplus state, in the case the chuck unit and the wafer support section lose synchronization, warping may occur in wafer W. Therefore, to prevent such a situation from occurring, the suction of wafer W by the seven chuck members <NUM> was released.

Next, main controller <NUM>, as is shown in <FIG>, synchronously drives chuck unit <NUM> and the three vertical-motion pins <NUM> (wafer support section <NUM>) downward, via chuck unit driving system <NUM> and driving device <NUM>. By this operation, chuck unit <NUM> and the three vertical-motion pins <NUM> (wafer support section <NUM>) are synchronously driven downward, while maintaining the suction (hold) state by chuck unit <NUM> (chuck member <NUM>) and the support state by the three vertical-motion pins <NUM> with respect to wafer W. This drive of chuck unit <NUM> and the three vertical-motion pins <NUM> (wafer support section <NUM>) is performed until the lower surface (rear surface) of wafer W comes into contact with a planar wafer mounting surface <NUM> of wafer table WTB (refer to <FIG>). Here, although wafer mounting surface <NUM> is actually a virtual flat plane (area) formed by the upper end surface of multiple pins that the pin chuck provided on wafer table WTB has, <FIG> and the like illustrates the upper surface of wafer table WTB serving as wafer mounting surface <NUM>.

Then, when the lower surface of wafer W comes into contact with the wafer table WTB upper surface (wafer mounting surface <NUM>) as is shown in <FIG>, main controller <NUM> stops the outflow of the high-pressure air flow from the eleven chuck members <NUM> at the outer circumference section via second adjustment device 125b, and after the suction of wafer W by all chuck members <NUM> has been released, begins the adsorption of wafer W by the wafer holder which is not shown on wafer table WTB. Next, main controller <NUM> drives chuck unit <NUM> upward to the waiting position previously described, via chuck unit driving system <NUM>, as is shown in <FIG>. This completes the loading (carry-in) of wafer W onto wafer table WTB. Further, the adsorption (suction) of wafer W by the wafer holder may be started before the lower surface of wafer W comes into contact with the wafer table WTB upper surface (wafer mounting surface <NUM>). In such a case, the suction of wafer W by all or a part of chuck member <NUM> may be released before the lower surface of wafer W comes into contact with the wafer table WTB upper surface (wafer mounting surface <NUM>).

After the loading of wafer W described above, alignment measurement (wafer alignment) such as EGA (Enhanced Global Alignment) is executed by main controller <NUM>, using alignment detection system <NUM>.

After the alignment measurement has been completed, exposure operation by the step-and-scan method is performed as is described below. On the exposure operation, first of all, wafer stage WST (wafer table WTB) is moved so that the XY position of wafer W is at a scanning starting position (acceleration starting position) for exposure of the first shot area (first shot) on wafer W. Simultaneously, reticle stage RST is moved so that the XY position of reticle R is at a scanning starting position. Then, scanning exposure is performed by main controller <NUM> synchronously moving reticles R and wafer W, via reticle stage driving system <NUM>, coarse movement stage driving system <NUM> and fine movement stage driving system <NUM>, based on position information of reticle R measured by reticle interferometer <NUM> and position information of wafer W measured by wafer interferometer <NUM>. During the scanning exposure, by main controller <NUM>, focus leveling control is performed, in which fine movement stage WFS is finely driven in the Z-axis direction, the θx direction and the θy direction based on measurement results of multi-point focal point detection system <NUM>, so that the irradiation area (exposure area) of illumination light IL of wafer W is made to coincide within the range of the depth of focus of the image plane of projection optical system PL.

When transfer of the reticle pattern with respect to a shot area is completed in this manner, stepping of wafer table WTB is performed by one shot area, and scanning exposure is performed with respect to the next shot area. In this manner, the stepping and the scanning exposure are sequentially repeated, so that the pattern of reticle R is overlaid and transferred to a predetermined number of shot areas on wafer W.

As is described so far, according to exposure apparatus <NUM> related to the present embodiment, on loading wafer W on wafer table WTB via chuck unit <NUM> and the three vertical-motion pins <NUM>, main controller <NUM> at first secures the flatness of wafer W by making the suction force of all chuck members <NUM> of chuck unit <NUM> act simultaneously on the upper surface of wafer W, and in a state maintaining the flatness, decreases the suction force by the seven chuck members <NUM> that suctions the center section area of the wafer W upper surface to zero at the stage where wafer W is supported (suction hold) from below by the three vertical-motion pins <NUM>. By this operation, the surplus-restraint in which wafer W receives forces from both side surfaces in the vertical direction of chuck unit <NUM> and vertical-motion pins <NUM> is prevented. Then, by chuck unit <NUM> and vertical-motion pins <NUM> being synchronously driven downward while the suction state by chuck unit <NUM> (chuck member <NUM>) and the support state by the three vertical-motion pins <NUM> are maintained, the entire surface of the rear surface of wafer W almost simultaneously or in the order of the center of the rear surface toward the outer circumference section comes into contact with wafer mounting surface <NUM>, and it becomes possible to load wafer W onto wafer table WTB in a state where there is no warping (a state in which the flatness degree is high).

Further, according to exposure apparatus <NUM> related to the present embodiment, because exposure is performed in a stepping-and-scanning method with respect to wafer W loaded on wafer table WTB in a state where the flatness degree is high, exposure without defocus to each of a plurality of shot areas on wafer W becomes possible, which allows the pattern of reticle R to be transferred favorably onto the plurality of shot areas.

Incidentally, in the embodiment above, the suction force of a plurality of (for example, eighteen) chuck members <NUM> was controlled for each group via the first adjustment device 125a or the second adjustment device 125b (refer to <FIG> ), the groups being the seven first groups placed in the center area of plate member <NUM> lower surface and the eleven second groups placed at the outer circumference section. However, the embodiment is not limited to this, and a structure can be employed in which the suction force of the plurality of (for example, eighteen) chuck members <NUM> can be set individually and arbitrarily. In this case, a design value of the suction force (that is, flow velocity of the fluid or the like blown out from chuck member <NUM>) and the placement of each of the plurality of chuck members <NUM> may be obtained in advance by fluid analysis, experiment or the like so that the suction force of the plurality of chuck members <NUM> with respect to wafer W becomes an optimal value (a value which does not generate warping caused by the surplus-restraint with respect to wafer W, and also a value which can secure a desired flatness degree of wafer W) corresponding to the position of each chuck member <NUM>.

Further, in the embodiment described above, while the case has been described where chuck members <NUM> were placed almost on the entire surface of the lower surface of plate member <NUM> of chuck unit <NUM>, the embodiment is not limited this, and for example, as is shown in <FIG>, in the embodiment described above only the chuck members <NUM> placed at the outer circumference section on the lower surface of plate member <NUM> whose suction force is adjusted by the second adjustment device 125b may be set. As a matter of course, in the case, the first adjustment device 125a is not necessary. Such a structure is suitable in a case when it is obvious that a desired flatness degree level of wafer W can be secured by only the chuck members <NUM> placed at the outer circumference section on the lower surface of plate member <NUM>. In the case of the structure shown in <FIG>, as long as chuck unit <NUM> and vertical-motion pins <NUM> are driven downward synchronously, there is almost no possibility that the periphery section at the rear surface of wafer W will come into contact with wafer mounting surface <NUM> before the center section. Alternately, wafer W can be made so that the desired level of flatness degree is secured by chuck members <NUM> and the three vertical-motion pins <NUM>. In this case, for example, by adjusting the driving velocity of chuck unit driving system <NUM> and driving device <NUM> while monitoring the flatness degree of the wafer, , it is possible to make wafer W have the desired level of flatness degree.

Further, in the embodiment described above, while the suction force of the seven chuck members <NUM> placed at the center section on the lower surface of plate member <NUM> was totally reduced to zero via the first adjustment device 125a at the stage where wafer W was supported from below by the three vertical-motion pins <NUM>, the embodiment is not limited to this, and the suction force of the seven chuck members <NUM> can be weakened (reduced), or the suction force of a part of the chuck members <NUM> of the seven chuck members <NUM> can be weakened (or reduced to zero).

Incidentally, in the embodiment described above, the first adjustment device 125a may be structured so that the suction force of the plurality of (seven) chuck members <NUM> is adjustable individually, or in groups which are decided in advance. Similarly, the second adjustment device 125b may be structured so that the suction force of the plurality of (eleven) chuck members <NUM> is adjustable individually, or in groups which are decided in advance.

Incidentally, in exposure apparatus <NUM> related to the embodiment described above, in the case plate member <NUM> of chuck unit <NUM> also functions as a cool plate, chuck unit <NUM> may wait in a state suctioning the wafer subject to the next exposure at the waiting position of the predetermined height above the loading position while exposure with respect to wafer W on wafer stage WST is being performed. In this case, wafer W can be controlled to a predetermined temperature even during the waiting.

Now, in exposure apparatus <NUM> related to the embodiment described above, when wafer W is loaded onto wafer table WTB, chuck unit <NUM> and the three vertical-motion pins <NUM> (wafer support section <NUM>) are driven downward synchronously (refer to <FIG>) while the suction state by chuck unit <NUM> (chuck member <NUM>) and the support state by the three vertical-motion pins <NUM> with respect to wafer W are maintained. On this operation, if chuck unit <NUM> and the three vertical-motion pins <NUM> (wafer support section <NUM>) lose synchronization on the drive and the latter is driven downward before the former, a driving force in the -Z direction by driving device <NUM> may act on the area adsorbed by the three vertical-motion pins <NUM> in the center of the lower surface of wafer W, which may cause the center section area of wafer W to deform (warp) in a downward protruded shape. In this case, while it can be considered to set the suction force of the seven chuck members placed at the center section area not to zero but to a predetermined value, and to provide the suction force to wafer W as an upward force opposing the driving force in the -Z direction described above, in such a way, it is as previously described that a surplus-restraint state will occur in wafer W.

Therefore, in order to restrain deformation to a downward protruded shape of the center section of wafer W described above, for example, instead of each of the three vertical-motion pins <NUM> previously described, for example, a vertical-motion pin <NUM> related to a first modified example having a structure as is shown in a sectional view in <FIG>, can be arranged on the upper surface of platform member <NUM>.

Vertical-motion pin <NUM>, as is shown in <FIG>, is equipped with a shaft member <NUM> fixed to the upper surface of platform member <NUM>, and a suspended member <NUM> which is attached slidable in the vertical direction with respect to shaft member <NUM> and has a recess section <NUM> of a predetermined depth formed on a surface opposing platform member <NUM>.

Suspended member <NUM>, as is shown in <FIG>, is equipped with a support section <NUM>, a slide section <NUM> and a stopper section <NUM>.

Support section <NUM> consists of a stepped rod-shaped member whose lower end is slightly thicker than other parts. Slide section <NUM> consists of a cylindrical (columnar) member which has a sectional shape when overlapping in a planar view the same with the lower end of support section <NUM>. Slide section <NUM> has a recess section of a predetermined depth, for example, whose sectional shape is circular, formed in the lower end surface. Slide section <NUM> and support section <NUM> are integrated by fixing the lower end surface of support section <NUM> to the upper surface of slide section <NUM>. Integration of slide section <NUM> and support section <NUM> is performed, for example, by bolting, by adhering or the like.

In support section <NUM> and slide section <NUM>, an exhaust pipeline <NUM> is provided which runs from an exhaust opening <NUM> formed at the upper end surface of support section <NUM>, passes through the inside of support section <NUM>, furthermore passes through the inside of slide section <NUM>, and opens at the outer circumference surface of slide section <NUM>. To the opening on the opposite side of exhaust opening <NUM> of exhaust pipeline <NUM>, one end of a vacuum piping is connected that has the other end connected to a vacuum pump which is not shown.

Stopper section <NUM> consists of a ring-shaped member that has an outer circumferential surface substantially flush with the outer circumferential surface of slide section <NUM> and an inner circumferential surface that protrudes slightly inward than the inner circumferential surface of inner slide section <NUM>, and on the inner circumferential side of its upper surface, a step section <NUM> is formed. Stopper section <NUM> and slide section <NUM> are integrated by stopper section <NUM> being fixed to the lower end surface of slide section <NUM>. Integration of stopper section <NUM> and slide section <NUM> is performed, for example, by bolting, by adhering or the like. Incidentally, while support section <NUM>, slide section <NUM>, and stopper section <NUM> can be formed as separate members and then be integrated into suspended member <NUM>, at least two parts can be integrally formed.

Shaft member <NUM> consists of a stepped columnar member in which a part of the lower end has a diameter smaller than other parts. The outer diameter of the large diameter section of shaft member <NUM> is slightly smaller than the inner diameter of the recess section of slide section <NUM>, for example, by several um to several tens of um. Further, the outer diameter of the small diameter section of shaft member <NUM> is smaller by around several mm than the inner diameter of stopper section <NUM>. The dimension in the height direction of shaft member <NUM> is a dimension in which the upper end surface of suspended member <NUM> is almost in contact with the bottom surface of the recess section of slide section <NUM>, in a state where suspended member <NUM> is in contact with the platform member <NUM>.

At the bottom surface (lower surface) of shaft member <NUM>, a space <NUM> having a circular sectional shape of a predetermined depth is formed in the center section. In shaft member <NUM>, a plurality of penetrating holes not shown that communicate with the outer circumferential surface from space are formed in a radial placement, at different height positions of the shaft member. To space <NUM>, a gas supply device (for example, a compressor) which is not shown is connected, via a gas supply pipeline and a gas supply pipe which are not shown.

The supply amount or the like of gas (for example, compressed air) into space <NUM> by the gas supply device which is not shown is controlled by main controller <NUM>. Here, when the compressed air is supplied into space <NUM>, the compressed air is made to blow out from between the outer circumferential surface of shaft member <NUM> and the inner circumferential surface of slide section <NUM>, via a plurality of penetrating holes which are not shown formed in the side wall of shaft member <NUM>. That is, an air static pressure bearing (air bearing) <NUM> is formed in between shaft member <NUM> and slide section <NUM>. Incidentally, in the description below, the outer circumferential surface of shaft member <NUM> (the inner circumferential surface of slide section <NUM>) will be referred to as a guide surface <NUM>, using the same reference sign as air bearing <NUM>.

In the section at the border of the large diameter section and the small diameter section of shaft member <NUM>, as is shown in <FIG>, a step section <NUM> is formed. Step section <NUM> of stopper section <NUM> is placed to face this step section <NUM>. A predetermined gap (gap) exists in between the opposing surfaces of step section <NUM> and step section <NUM>. In strokes corresponding to the size of this gap, suspended member <NUM> is drivable along guide surface <NUM> with respect to shaft member <NUM>. Strokes in the vertical direction of suspended member <NUM> are restricted by stopper section <NUM>. Meanwhile, movement of suspended member <NUM> in the horizontal plane is restricted (restrained) by shaft member <NUM>. Incidentally, since stopper section <NUM> only has to restrict the strokes in the vertical direction of suspended member <NUM>, stopper section <NUM> does not necessarily have to be annular.

In the exposure apparatus equipped with wafer stage WST that has a wafer support section having three vertical-motion pins <NUM> with the structure described above provided on the upper surface of platform member <NUM>, loading of wafer W onto wafer table WTB is performed in a procedure similar to the embodiment described above.

On this operation, in the state immediately after supporting wafer W suctioned in a non-contact manner by chuck unit <NUM> (chuck member <NUM>) corresponding to <FIG> from below by the three vertical-motion pins <NUM>, suspended member <NUM> of vertical-motion pin <NUM>, as is shown in <FIG>, is positioned at the lowest end position (movement lower limit position) within the stroke range.

Next, wafer W is driven downward along with chuck unit <NUM> and vertical-motion pins <NUM>, while maintaining the predetermined gap with respect to chuck unit <NUM> (chuck member <NUM>). On this operation, due to the difference of driving responsiveness between chuck unit <NUM> and vertical-motion pins <NUM>, vertical-motion pins <NUM> may be driven downward before chuck unit <NUM>. In this case, immediately after the beginning of the drive, shaft member <NUM> is driven along guide surface <NUM> downward with respect to slide section <NUM> within a range of predetermined strokes, in a state where the position of suspended member <NUM> is maintained. Then, when step section <NUM> of shaft member <NUM> hits step section <NUM> of stopper section <NUM>, suspended member <NUM> will also be driven downward by driving device <NUM>, along with shaft member <NUM>. Accordingly, if the downward movement of chuck unit <NUM> synchronous with the three vertical-motion pins <NUM> begins by the time step section <NUM> of shaft member <NUM> hits step section <NUM> of stopper section <NUM>, generation of deformation (flexure) previously described to a downward protruded shape of the center section of wafer W due to the action of the driving force in the -Z direction caused by driving device <NUM> can be suppressed.

Meanwhile, in case the responsiveness of chuck unit <NUM> is superior to the responsiveness of vertical-motion pins <NUM> and chuck unit <NUM> begins to move downward earlier on the synchronous drive, prior to starting the downward movement of chuck unit <NUM> immediately after wafer W suctioned in a non-contact manner by chuck unit <NUM> (chuck member <NUM>) is supported from below by the three vertical-motion pins <NUM>, shaft member <NUM> is positioned to the movement lower limit position where step section <NUM> hits the step section <NUM> of stopper section <NUM>. This allows the generation of deformation (flexure) to an upward protruded shape of the center section of wafer W to be restrained.

Now, in the exposure apparatus equipped with wafer stage WST having the wafer support section described above related to the first modified example with the three vertical-motion pins <NUM> provided on the upper surface of platform member <NUM>, deformation to a downward protruded shape (or an upward protruded shape) of the center section of wafer W caused by the difference of responsiveness described above between chuck unit <NUM> and vertical-motion pins <NUM> can be restrained. However, the self-weight of suspended member <NUM> acts as a force in a downward direction with respect to wafer W. Therefore, instead of vertical-motion pins <NUM> or vertical-motion pins <NUM>, a vertical-motion pin <NUM> related to a second modified example below can also be used.

Vertical-motion pin <NUM> related to a second modified example, as is shown in <FIG>, is basically structured in a similar manner as vertical-motion pin <NUM> previously described, however, the following points are different. That is, as is shown in <FIG>, vertical-motion pin <NUM> has an air chamber <NUM> and an exhaust hole <NUM> formed inside which are the points different from vertical-motion pin <NUM>, and since other structures and functions are the same as in the first modified example, the description thereabout will be omitted.

As is shown in <FIG>, air chamber <NUM> is formed inside vertical-motion pin <NUM> (to be more precise, in between slide section <NUM> and shaft member <NUM>). Air chamber <NUM> communicates with space <NUM>, via an air flow passage <NUM> formed below. Therefore, a part of compressed air supplied into space <NUM> via a gas supply device which is not shown passes through air flow passage <NUM> and flows into air chamber <NUM>. That is, the pressure in air chamber <NUM> is higher (positive pressure) when compared with the pressure in the space where vertical-motion pin <NUM> is placed, and a force in an upward direction is applied to suspended member <NUM>. Here, by controlling the gas supply device so that the upward force by the compressed air flowing into air chamber <NUM> is balanced with the downward force in the vertical direction by the self-weight of suspended member <NUM>, it can prevent the self-weight of suspended member <NUM> from acting as a downward force with respect to wafer W.

Exhaust hole <NUM> consists of an opening formed near the upper end of the side surface of slide section <NUM> (the side surface on the -X side in <FIG>), and communicates with air chamber <NUM> via air flow passage <NUM>. That is, a part of the compressed air flowing into air chamber <NUM> is constantly exhausted from exhaust hole <NUM>.

As is described so far, in the exposure apparatus that is equipped with wafer stage WST having a wafer support section in which three vertical-motion pins <NUM> of the structure described above are provided on the upper surface of platform member <NUM>, other than being able to obtain the same effect as the exposure apparatus equipped with the three vertical-motion pins <NUM> described above, by making the pressure inside air chamber <NUM> be positive an upward force equal to its self-weight is applied to suspended member <NUM>, which can prevent deformation occurring to wafer W by the self-weight of suspended member <NUM> when suspended member <NUM> is suspended from the wafer W lower surface. That is, wafer W is mounted on wafer table WTB in a state where wafer W has a higher degree of flatness.

Further, since exhaust hole <NUM> is formed communicating with air chamber <NUM>, vertical-motion pin <NUM> serves as a damper due to viscous resistance of air such as when wafer W held by suction by wafer table WTB is separated from wafer table WTB by being pushed from below by vertical-motion pin <NUM>, which can prevent wafer W from vibrating (jumping).

Other than this, instead of vertical-motion pin <NUM>, a vertical-motion pin <NUM> related to a third modified example below can be used.

As is shown in <FIG>, a vertical-motion pin <NUM> is equipped with a housing <NUM> fixed on the upper surface of platform member <NUM>, and a shaft member <NUM> in which a part of the member is housed in housing <NUM>.

Housing <NUM> consists of a cylindrical member with a bottom that has an opening at the lower end surface and a space <NUM> formed inside. Further, in the upper wall (bottom section) of housing <NUM>, a penetrating hole <NUM> having a circular sectional shape whose diameter is smaller than the inner diameter of housing <NUM> is formed in the vertical direction. In the inner circumferential surface section of penetrating hole <NUM> in the upper wall of housing <NUM>, grooves which are not shown extending in the Z-axis direction are formed at an equal spacing in the radial direction in a planar view. Hereinafter, for the sake of convenience, the grooves will be described as groove <NUM>, using the same reference sign as penetrating hole <NUM>.

Shaft member <NUM> consists of a columnar member whose diameter is slightly smaller than the diameter of penetrating hole <NUM> formed in the upper wall section of housing <NUM>, and a flanged section <NUM> which projects outward is provided at the lower end. Flanged section <NUM> has an outer diameter larger than the inner diameter of penetrating hole <NUM>. Shaft member <NUM> is inserted into penetrating hole <NUM> of housing <NUM> from below, and is allowed to move only in the Z-axis direction with respect to housing <NUM> within a predetermined stroke range. Shaft member <NUM> has a flanged section, a nut or the like which is not shown provided (or joined) at the outer circumference of the upper end so as to prevent the shaft member from dropping inside housing <NUM>. Incidentally, instead of the flanged section, a nut or the like which is not shown provided at the outer circumference of the upper end in shaft member <NUM>, the length of shaft member <NUM> in the long axis (Z-axis) direction can be increased with respect to housing <NUM>, so that the upper surface of shaft member <NUM> is positioned above the upper surface of housing <NUM> when the shaft member <NUM> is positioned at the lowermost end of the strokes.

Further, in shaft member <NUM>, a penetrating hole <NUM> is formed in the center section extending in the Z-axis direction, for example, having a circular sectional shape. Penetrating hole <NUM> has one end (the -Z end) connected to a vacuum pump which is not shown, via a piping which is not shown.

In the exposure apparatus that is equipped with wafer stage WST having a wafer support section in which three vertical-motion pins <NUM> of the structure described above are provided on the upper surface of platform member <NUM>, loading of wafer W onto wafer table WTB is performed in a procedure similar to the embodiment described above.

On this operation, in a state immediately after supporting wafer W suctioned in a non-contact manner by chuck unit <NUM> (chuck member <NUM>) corresponding to <FIG> with the three vertical-motion pins <NUM> from below, shaft member <NUM> of vertical-motion pin <NUM> is at the lowest end position within the stroke range (or at a position in which the bottom surface is in contact with the upper surface of platform member <NUM>).

Next, wafer W is driven downward with chuck unit <NUM> and vertical-motion pins <NUM>, while a predetermined gap is maintained with respect to chuck unit <NUM> (chuck member <NUM>). On this operation, driving of vertical-motion pins <NUM> downward may start earlier than chuck unit <NUM>, due to the difference of driving responsiveness between chuck unit <NUM> and vertical-motion pins <NUM>. In this case, immediately after the driving begins, housing <NUM> is driven downward within the predetermined stroke range in a state where the position of shaft member <NUM> is maintained. On this drive, an air flow occurs in groove <NUM>, and in between shaft member <NUM> and housing <NUM>, housing <NUM> is driven in a state where there is almost no friction (that is, a dynamic pressure bearing is structured in between shaft member <NUM> and housing <NUM>). Then, when the upper surface of flanged section <NUM> hits the upper wall of housing <NUM>, shaft member <NUM> will also be driven downward with housing <NUM> by driving device <NUM>. Accordingly, if the downward movement of chuck unit <NUM> synchronous with the three vertical-motion pins <NUM> is started before the upper surface of flanged section <NUM> hits the upper wall of housing <NUM>, generation of deformation (flexure) previously described to a downward protruded shape of the center section of wafer W caused by the driving force acting in the -Z direction by driving device <NUM> can be restrained.

As is described so far, in the exposure apparatus that is equipped with wafer stage WST having a wafer support section in which three vertical-motion pins <NUM> of the structure described above are provided on the upper surface of platform member <NUM>, other than being able to obtain the same effect as the exposure apparatus equipped with the three vertical-motion pins <NUM> described above, because the structure of vertical-motion pin <NUM> is simplified, the weight of the entire device can be reduced. Further, because the gas supply device and a part of the piping member can be omitted, this makes the layout easy, and at the same time improves assembly workability.

Incidentally, in the vertical-motion pin <NUM> related to the third modified example, while the dynamic pressure bearing was structured by providing the plurality of grooves in the inner circumferential surface of penetrating hole <NUM> at the upper wall of housing <NUM>, the embodiment is not limited to this, and for example, the dynamic pressure bearing can be structured by forming grooves on the outer circumferential surface of shaft member <NUM> in equal spacing in the axis direction. Further, shaft member <NUM> and housing <NUM> can be a sliding bearing, using members having a small friction coefficient.

Further, in the embodiment and each modified example described above (hereinafter referred to as the embodiments described above), while the shape of chuck unit <NUM> was circular in a planar view, the embodiments described above are not limited to this, and for example, can have a rectangular shape or the like, as long as wafer W can be suctioned from above in a non-contact manner.

Further, in the embodiments described above, while the three vertical-motion pins <NUM> (<NUM>, <NUM>, <NUM>) were each vertically moved integrally, the embodiments described above are not limited to this, and each pin can be vertically moved independently. For example, wafer support section <NUM> can be structured so that the three vertical-motion pins can vertically move independently, so as to keep the flatness degree of wafer W within a desired range by vertically moving the three vertical-motion pins individually, based on monitoring results of wafer flatness. Incidentally, the number of vertical-motion pins is not limited to three, and can be more or less than three pins.

Further, in the embodiments described above, while an example of a dry type exposure apparatus which performs exposure of wafer W without using liquid (water) was described, the embodiments described above can also be applied to an exposure apparatus in which a liquid immersion space including an optical path of an illumination light is formed between a projection optical system and a wafer and the wafer is exposed by the illumination light via the projection optical system and the liquid of the liquid immersion space, as is disclosed in, for example, <CIT>, <CIT>, <CIT>, <CIT> and the like. Further, the embodiments described above can also be applied to a liquid immersion exposure apparatus or the like disclosed in, for example, <CIT>.

Further, in the embodiments described above, while the case has been described where the exposure apparatus is a scanning type exposure apparatus of the step-and-scan method or the like, the embodiments are not limited to this, and the embodiments described above can also be applied to a stationary type exposure apparatus such as a stepper. Further, the embodiments described above can also be applied to a reduction projection exposure apparatus of the step-and-stitch method in which a shot area and a shot area are synthesized, an exposure apparatus of the proximity method, a mirror projection aligner or the like. Furthermore, the embodiments described above can also be applied to a multi-stage type exposure apparatus equipped with a plurality of wafer stages, as is disclosed in, for example, <CIT>, <CIT>, <CIT> or the like. Further, the embodiments described above can also be applied to an exposure apparatus equipped with a measurement stage separate from the wafer stage, including a measurement member (for example, a reference mark, and/or a sensor or the like), as is disclosed in, for example, PCT International Publication No.<NUM>/<NUM> or the like.

Further, the projection optical system in the exposure apparatus of the embodiments described above is not limited to a reduction system, and can either be an equal-magnifying or a magnifying system, and projection optical system PL is not limited to a refractive system, and can either be a reflection system or a catadioptric system, and its projection image can either be an inverted image or an erect image. Further, while the shape of the illumination area and the exposure area previously described was a rectangular shape, the embodiments are not limited to this, and for example, the shape can be an arc, a trapezoid, a parallelogram or the like.

Further, the light source of the exposure apparatus related to the embodiments described above is not limited to the ArF excimer laser, and a pulse laser light source such as a KrF excimer laser (output wavelength <NUM>), an F<NUM> laser (output wavelength <NUM>), an Ar<NUM> laser (output wavelength <NUM>), or a Kr<NUM> laser (output wavelength <NUM>), a super high pressure mercury lamp which generates a bright line such as a g-line (wavelength <NUM>), an i-line (wavelength <NUM>), or the like can also be used. Further, a harmonic wave generating device which uses a YAG laser can also be used. As other light sources, as is disclosed in, for example, <CIT>, a harmonic wave can also be used as vacuum ultraviolet light, in which a single-wavelength laser beam in the infrared range or the visible range emitted by a DFB semiconductor laser or a fiber laser is amplified by a fiber amplifier doped with, for example, erbium (or both erbium and ytterbium) and wavelength conversion into ultraviolet light is performed using a nonlinear optical crystal.

Further, in the embodiments described above, as illumination light IL of the exposure apparatus, the light is not limited to light having a wavelength of <NUM> or more, and as a matter of course, light having a wavelength less than <NUM> can also be used. For example, the embodiments described above can suitably be applied to an EUV exposure apparatus which uses EUV (Extreme Ultraviolet) light in the soft X-ray region (for example, a wavelength region of <NUM> to <NUM>). Other than this, the embodiments described above can also be applied to an exposure apparatus which uses a charged particle beam such as an electron beam or an ion beam.

Furthermore, the embodiments described above can also be applied to an exposure apparatus which synthesizes two reticle patterns on a wafer via the projection optical system and performs double exposure almost simultaneously on a shot area on the wafer by performing scanning exposure once, as is disclosed in, for example, <CIT>.

Further, the object on which the pattern should be formed (the object subject to exposure on which the energy beam is irradiated) in the embodiments described above is not limited to the wafer, and may be other objects such as a glass plate, a ceramic substrate, a film member, or a mask blank.

The usage of the exposure apparatus is not limited to the exposure apparatus for manufacturing semiconductors, and the embodiments above can be widely applied, for example, to an exposure apparatus for liquid crystals that transfers a liquid crystal display devices pattern onto a square-shaped glass plate, an exposure apparatus for manufacturing an organic EL, a thin film magnetic head, an imaging element (such as a CCD), a micromachine and a DNA chip or the like. Further, the embodiments described above can also be applied to an exposure apparatus that transfers a circuit pattern onto a glass substrate or a silicon wafer for manufacturing a reticle or a mask that is used in not only microdevices such as semiconductor devices, but also used in an optical exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, an electron beam exposure apparatus or the like.

Claim 1:
A carrier system for carrying a plate-like object (W) to a holding member provided with an object mounting surface on an upper surface, the system comprising:
the holding member;
a support section (<NUM>) provided at the holding member;
a vertically-movable suction unit (<NUM>) having a plurality of suction members (<NUM>) able to suction a plurality of places including at least an area at an outer circumference section of a surface of the object,
the carrier system being configured to carry the suction unit to above the holding member located at a predetermined carry-in position,
the suction members each being configured to generate a suction force to suction a surface of the object from above in a non-contact manner,
the support section being vertically movable and configured to support from below a part of the center section area at another surface of the object; and
a driving device (<NUM>) configured to drive the suction unit and the support section downward so that the other surface of the object moves toward the object mounting surface of the holding member, in a state where a suction state by the suction unit and a support state by the support section with respect to the object is maintained.