JP2009252988A - Aligner, device method for manufacturing, and maintenance method for aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain precision of position measurement of an encoder system and then high driving precision of a moving body inexpensively. <P>SOLUTION: A plate 28 forming a top portion of a wafer table is composed of a first liquid repellent plate 28a and four second liquid repellent plates 28b<SB>1</SB>to 28b<SB>4</SB>. The four second liquid repellent plates have X scales 39X<SB>1</SB>and 39X<SB>2</SB>, and Y scales 39Y<SB>1</SB>and 39Y<SB>2</SB>respectively for the encoder system. The liquid repellent plates 28a, and 28b<SB>1</SB>to 28b<SB>4</SB>are fixed on an upper surface of a table body 29 individually through vacuum suction. Only the second liquid repellent plates having, especially, the scales which are frequently replaced can be replaced without attaching nor detaching other liquid repellent plates. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exposure apparatus, a device manufacturing method, and a maintenance method of the exposure apparatus. More specifically, the present invention relates to an exposure apparatus used in a lithography process for manufacturing a semiconductor element (such as an integrated circuit), and a device manufacturing using the exposure apparatus. And a maintenance method of the exposure apparatus.

  Conventionally, in a lithography process for manufacturing electronic devices (microdevices) such as semiconductor elements (integrated circuits, etc.), liquid crystal display elements, etc., a step-and-repeat type projection exposure apparatus (so-called stepper) or a step-and-scan type Projection exposure apparatuses (so-called scanning steppers (also called scanners)) are mainly used.

  In this type of exposure apparatus, due to the miniaturization of patterns due to the recent high integration of semiconductor elements, the requirement for overlay accuracy becomes strict, and a substrate such as a wafer or a glass plate (hereinafter collectively referred to as a wafer) is held. Short-term fluctuations in measured values due to air fluctuations in the laser interferometer used to measure the position of the wafer stage have become a major weight in the overlay budget. Therefore, an exposure apparatus that employs an encoder that has a measurement resolution comparable to or higher than that of a laser interferometer and is generally less susceptible to air fluctuations than an interferometer is proposed as a wafer stage position measurement device. (For example, refer to Patent Document 1).

  However, in the exposure apparatus disclosed in Patent Document 1, since a plate configured by combining the first and second liquid repellent plates is fixed on the wafer stage (wafer table), the table surface is configured. It was difficult to remove only one of the first and second liquid repellent plates from the wafer table. Also, since the outer second liquid repellent plate is formed with a plurality of scales constituting the encoder system, even if only one scale needs to be replaced due to dirt or the like, the plate (or the second liquid repellent plate) Plate), ie, all scales need to be replaced. For these reasons, the exposure apparatus disclosed in Patent Document 1 may have an excessive running cost.

International Publication No. 2007/097379 Pamphlet

  The present invention has been made under the circumstances described above. From a first viewpoint, the present invention is an exposure apparatus that irradiates an energy beam to form a pattern on an object, and holds the object in a predetermined plane. A plurality of movable bodies, each of which is individually and detachably fixed on a surface substantially parallel to the predetermined plane on which the object of the movable body is placed, each of which is formed with a diffraction grating An encoder system having a plurality of heads that project a measurement beam onto the grating member and measure the position of the movable body in the predetermined plane; based on a measurement result of the encoder system, An exposure apparatus comprising: a driving device that drives the moving body;

  According to this, a plurality of grating members on which diffraction gratings are formed are fixed individually and detachably on one surface of a moving body substantially parallel to a predetermined plane on which an object is placed. Therefore, among the plurality of grating members, for example, due to deterioration or the like, only the grating member on which the diffraction grating that needs to be replaced can be replaced individually without attaching or detaching other grating members. Therefore, not only the cost for exchanging the diffraction grating is suppressed, but also the maintenance of the encoder system such as correction of measurement errors is facilitated. Therefore, the position measurement accuracy of the encoder system and the high driving accuracy of the moving body by the driving device can be maintained at a low cost, and as a result, the pattern can be formed on the object with high accuracy. .

  According to a second aspect of the present invention, there is provided a device manufacturing method comprising: a step of forming a pattern on an object using the exposure apparatus of the present invention; and a step of processing the object on which the pattern is formed. It is.

  According to a third aspect of the present invention, there is provided an exposure apparatus maintenance method for irradiating an object held by a moving body moving within a predetermined plane with an energy beam and forming a pattern on the object, wherein the movement The movable body within the predetermined plane of the movable body, which is individually and detachably fixed on a surface substantially parallel to the predetermined plane on which the object is placed, and in which a diffraction grating is formed, respectively. This is a maintenance method for an exposure apparatus including a step of performing replacement processing for some of the plurality of grating members, in which measurement beams are projected from a plurality of heads for measuring positions.

  According to this, in a predetermined plane of the moving body, each of which is individually and detachably fixed on a plane substantially parallel to the predetermined plane on which the object of the moving body is placed, and each has a diffraction grating formed thereon. Replacement processing for a part of the lattice members among the plurality of lattice members is performed, in which measurement beams are projected from the plurality of heads that measure the positions at the positions. Therefore, among the plurality of grating members, for example, due to deterioration or the like, only the grating member on which the diffraction grating that needs to be replaced can be replaced individually without attaching or detaching other grating members. Therefore, not only the cost for exchanging the diffraction grating is suppressed, but also the maintenance of the encoder system such as correction of measurement errors is facilitated.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to FIGS.

  FIG. 1 schematically shows a configuration of an exposure apparatus 100 according to an embodiment. The exposure apparatus 100 is a step-and-scan projection exposure apparatus, that is, a so-called scanner. As will be described later, in the present embodiment, a projection optical system PL and a primary alignment system AL1 (see FIGS. 7 and 8, etc.) are provided. In the following, the direction parallel to the optical axis AX of the projection optical system PL is the Z-axis direction, and the direction parallel to the straight line connecting the optical axis AX and the detection center of the primary alignment system AL1 in the plane orthogonal to this is the Y-axis direction. The direction orthogonal to the Z axis and the Y axis is defined as the X axis direction, and the rotation (tilt) directions around the X axis, the Y axis, and the Z axis are defined as the θx, θy, and θz directions, respectively.

  The exposure apparatus 100 includes an illumination system 10, a reticle stage RST, a projection unit PU, a local immersion apparatus 8, a stage apparatus 50 having a wafer stage WST and a measurement stage MST, a control system for these, and the like. In FIG. 1, wafer W is placed on wafer stage WST.

  The illumination system 10 includes a light source, an illuminance uniformizing optical system including an optical integrator, a reticle blind, and the like (both not shown) as disclosed in, for example, US Patent Application Publication No. 2003/0025890. And an illumination optical system. The illumination system 10 illuminates the slit-shaped illumination area IAR on the reticle R defined by the reticle blind (masking system) with illumination light (exposure light) IL with substantially uniform illuminance. Here, as an example of the illumination light IL, ArF excimer laser light (wavelength 193 nm) is used.

  On reticle stage RST, reticle R having a circuit pattern or the like formed on its pattern surface (lower surface in FIG. 1) is fixed, for example, by vacuum suction. The reticle stage RST can be finely driven in the XY plane by a reticle stage drive system 11 (not shown in FIG. 1, refer to FIG. 10) including, for example, a linear motor, and the scanning direction (left and right direction in FIG. 1). In the Y-axis direction) at a predetermined scanning speed.

  Position information in the XY plane of reticle stage RST (including rotation information in the θz direction) is transferred by reticle laser interferometer (hereinafter referred to as “reticle interferometer”) 116 to movable mirror 15 (actually in the Y-axis direction). Through a Y-moving mirror (or retro reflector) having an orthogonal reflecting surface and an X moving mirror having a reflecting surface orthogonal to the X-axis direction), detection is always performed with a resolution of, for example, about 0.25 nm. Is done. The measurement value of reticle interferometer 116 is sent to main controller 20 (not shown in FIG. 1, refer to FIG. 10).

  Projection unit PU is arranged below reticle stage RST in FIG. The projection unit PU includes a lens barrel 40 and a projection optical system PL held in the lens barrel 40. As projection optical system PL, for example, a refractive optical system including a plurality of optical elements (lens elements) arranged along optical axis AX parallel to the Z-axis direction is used. The projection optical system PL is, for example, both-side telecentric and has a predetermined projection magnification (for example, 1/4 times, 1/5 times, or 1/8 times). For this reason, when the illumination area IAR on the reticle R is illuminated by the illumination system 10, the illumination light that has passed through the reticle R arranged so that the first surface (object surface) and the pattern surface of the projection optical system PL substantially coincide with each other. The reduced image of the circuit pattern of the reticle R in the illumination area IAR (a reduced image of a part of the circuit pattern) is passed through the projection optical system PL (projection unit PU) by the IL on the second surface (image surface) side. And is formed in an area IA (hereinafter also referred to as an exposure area) IA conjugate to the illumination area IAR on the wafer W having a surface coated with a resist (sensitive agent). Then, by synchronous driving of reticle stage RST and wafer stage WST, reticle R is moved relative to illumination area IAR (illumination light IL) in the scanning direction (Y-axis direction) and exposure area IA (illumination light IL). By moving the wafer W relative to the scanning direction (Y-axis direction), scanning exposure of one shot area (partition area) on the wafer W is performed, and a reticle pattern is transferred to the shot area. . That is, in this embodiment, a pattern is generated on the wafer W by the illumination system 10, the reticle R, and the projection optical system PL, and the pattern is formed on the wafer W by exposure of the sensitive layer (resist layer) on the wafer W by the illumination light IL. Is formed.

  The exposure apparatus 100 of the present embodiment is provided with a local liquid immersion apparatus 8 for performing immersion type exposure. The local liquid immersion device 8 includes a liquid supply device 5, a liquid recovery device 6 (both not shown in FIG. 1, refer to FIG. 10), a liquid supply tube 31A, a liquid recovery tube 31B, a nozzle unit 32, and the like. As shown in FIG. 1, the nozzle unit 32 holds an optical element on the most image plane side (wafer W side) constituting the projection optical system PL, here a lens (hereinafter also referred to as “tip lens”) 191. It is suspended and supported by a main frame (not shown) that holds the projection unit PU so as to surround the lower end portion of the lens barrel 40. In the present embodiment, as shown in FIG. 1, the lower end surface of the nozzle unit 32 is set substantially flush with the lower end surface of the front lens 191. Further, the nozzle unit 32 is connected to the supply port and the recovery port of the liquid Lq, the lower surface on which the wafer W is disposed and provided with the recovery port, and the supply connected to the liquid supply tube 31A and the liquid recovery tube 31B, respectively. A flow path and a recovery flow path are provided. As shown in FIG. 7, the liquid supply pipe 31A and the liquid recovery pipe 31B are inclined by approximately 45 ° with respect to the X-axis direction and the Y-axis direction in plan view (viewed from above). The arrangement is symmetric with respect to a straight line (hereinafter referred to as a reference axis) LV parallel to the Y axis connecting the optical axis AX and the detection center of the primary alignment system AL1.

  The liquid supply pipe 31A is connected to the liquid supply apparatus 5 (not shown in FIG. 1, see FIG. 10), and the liquid recovery pipe 31B is connected to the liquid recovery apparatus 6 (not shown in FIG. 1, see FIG. 10). Here, the liquid supply device 5 includes a tank for storing the liquid, a pressurizing pump, a temperature control device, a valve for controlling the flow rate of the liquid, and the like. The liquid recovery device 6 includes a tank for storing the recovered liquid, a suction pump, a valve for controlling the flow rate of the liquid, and the like.

  The main controller 20 controls the liquid supply device 5 (see FIG. 10) to supply liquid between the front lens 191 and the wafer W via the liquid supply pipe 31A. The liquid recovery apparatus 6 (see FIG. 10) is controlled to recover the liquid from between the front lens 191 and the wafer W via the liquid recovery tube 31B. At this time, the main controller 20 controls the liquid supply device 5 and the liquid recovery device 6 so that the amount of supplied liquid and the amount of recovered liquid are always equal. Accordingly, a certain amount of liquid Lq (see FIG. 1) is always exchanged and held between the front lens 191 and the wafer W, thereby forming the liquid immersion region 14 (see FIG. 7). In addition, even when a measurement stage MST described later is positioned below the projection unit PU, the liquid immersion region 14 can be similarly formed between the tip lens 191 and the measurement table.

  In this embodiment, pure water that transmits ArF excimer laser light (light having a wavelength of 193 nm) (hereinafter, simply referred to as “water” unless otherwise required) is used as the liquid. Note that the refractive index n of water with respect to ArF excimer laser light is approximately 1.44, and the wavelength of the illumination light IL is shortened to 193 nm × 1 / n = about 134 nm in water.

  As shown in FIG. 1, the stage apparatus 50 includes a wafer stage WST and a measurement stage MST disposed above the base board 12, and a measurement system 200 (see FIG. 10) that measures positional information of both stages WST and MST. And a stage drive system 124 (see FIG. 10) for driving both stages WST and MST. As shown in FIG. 10, the measurement system 200 includes an interferometer system 118, an encoder system 150, a surface position measurement system 180, and the like.

  Wafer stage WST and measurement stage MST are supported above base plate 12 by a non-contact bearing (not shown) with a clearance of about several μm. Both stages WST and MST can be driven independently in the XY plane by a stage drive system 124 (see FIG. 10) including a linear motor or the like.

  Wafer stage WST includes a stage main body 91 and a wafer table WTB mounted on stage main body 91, as shown in FIG. Wafer table WTB and stage main body 91 are moved in directions of six degrees of freedom (X, Y, Z, θx, θy) relative to base board 12 by a drive system including a linear motor and a Z / leveling mechanism (including a voice coil motor). , Θz).

  Wafer table WTB includes a table main body 29 provided with a wafer holder WH at the center of the upper surface thereof, as shown in FIG. 3 which is a schematic exploded perspective view of wafer table WTB. As the wafer holder WH, a vacuum chuck having a large number of pins HP (see FIG. 4B) is used. As the wafer holder WH, for example, one having a configuration disclosed in International Publication No. 2003/052804 pamphlet can be used. In FIG. 3 and the like, the center-up mechanism and the like are not shown.

  As shown in FIG. 2, a circular opening that is slightly larger than the wafer W held by the wafer holder WH is formed at the center outside the wafer holder WH (wafer W mounting region) on the upper surface of the table main body 29. An apparently integrated plate 28 having a rectangular outer shape (contour) is provided.

  In this embodiment, the plate 28 is composed of five members to be described later. The surface of these members is coated with a fluorine resin material, a fluorine resin material such as polytetrafluoroethylene (Teflon (registered trademark)), an acrylic resin material, or a silicon resin material (repellent property). A liquid repellent film having liquid repellency to the liquid Lq is formed. Therefore, hereinafter, the plate 28 is also referred to as a liquid repellent plate 28 as appropriate.

As shown in FIGS. 3 and 4A, the liquid repellent plate 28 includes a first liquid repellent plate 28a having a rectangular outer shape (contour) in which the above-described circular opening is formed at the center, and a first liquid repellent plate 28a. consists of five members of the second liquid repellent plate 28b ₁ ~28b ₄ four elongated rectangular shape surrounding the peripheral edge of the liquid plate 28a. Each of the liquid repellent plates 28a, 28b _{1 to} 28b ₄ is made of a material having a low coefficient of thermal expansion, such as glass or ceramics (for example, Zerodure (trade name), Al ₂ O _3, TiC, etc. of Schott).

Here, while the illumination light IL is frequently irradiated in the first liquid repellent plate 28a, the second liquid repellent plate 28b ₁ ~28b ₄ outside is not irradiated illumination light IL is hardly. Therefore, the surface of the first liquid repellent plate 28a is provided with a liquid repellent coat that is sufficiently resistant to the illumination light IL, and the surfaces of the second water repellent plates 28b _{1 to} 28b ₄ are provided with the first liquid repellent plate 28a. A liquid repellent coating is provided which is inferior in resistance to the illumination light IL as compared with the above.

In general, it is difficult to apply a liquid repellent coating that is sufficiently resistant to the illumination light IL (particularly vacuum ultraviolet light) on the glass plate. From this point of view as well, the liquid repellent plate 28 is disposed on the inner first repellent plate as described above. It is effective to configure the liquid plate 28a and the outer second liquid repellent plates 28b _{1 to} 28b ₄ . Needless to say, the same kind of liquid repellent coating having sufficient resistance to the illumination light IL (particularly vacuum ultraviolet light) may be applied to all the surfaces of the liquid repellent plates 28a, 28b _{1 to} 28b ₄ .

On the upper surface of the table main body 29, as shown in FIG. 3, a region 29a surrounded by an annular convex portion surrounding the rim portion of the outer peripheral portion of the wafer holder WH described above and a square convex portion outside thereof, and four narrow rectangular regions 29b ₁ ~29b ₄ surrounding the area 29a is provided. The region 29b ₁ and the region 29b ₂ are arranged at the + X end portion and the −X end portion of the upper surface of the table body 29 with the region 29a, the regions 29b ₃ and 29b ₄ sandwiched in the X-axis direction. Further, the regions 29b ₃ and 29b ₄ are arranged at the + Y end portion and the −Y end portion of the upper surface of the table main body 29 with the region 29a sandwiched in the Y axis direction. The regions 29b _{1 to} 29b ₄ are surrounded on all sides by a convex portion having a rectangular frame shape. The upper end surface of each of the convex portions on the upper surface of wafer table WTB is set at substantially the same height as the rim portion of wafer holder WH. Here, a later-described measurement plate 30 is provided in the center of the boundary between the region 29a and the region 29b _{3 in} the X-axis direction.

  In each of the five regions on the upper surface of the table main body 29, a large number of pins VP (see FIG. 4B) are provided at predetermined intervals, like the wafer holder WH.

In the region 29a, as shown in FIG. 4 (B), is formed at a position where the two exhaust ports VC ₁ communicating with a vacuum exhaust line (not shown) formed on the table body 29 does not interfere with the pin VP Yes. Evacuation pipe communicating with these two exhaust ports VC ₁ is connected to a vacuum pump 43A (see FIG. 10) via the evacuation pipe (not shown).

In each of the regions 29b ₁ , 29b ₂ , 29b ₃ , 29b ₄ , exhaust ports VC ₂ , VC ₃ , VC ₄ , VC ₅ are provided at positions where they do not interfere with the pin VP. The exhaust ports VC ₂ , VC ₃ , VC ₄ , VC ₅ communicate with vacuum exhaust pipes (not shown) formed in the table body 29, and each vacuum exhaust pipe is connected to a vacuum pump via the vacuum exhaust pipe. 43B, 43C, 43D, and 43E (see FIG. 10) are individually connected.

On the lower surface (the surface on the −Z side) of the first liquid repellent plate 28a, as shown in FIG. 4A, cylindrical positioning pins PC are projected in the vicinity of the four corners. Corresponding to the four positioning pins PC, as shown in FIG. 4B, a circle having a slightly larger diameter than the positioning pins PC is provided in the vicinity of the four corners of the first region 29a on the upper surface of the table body 29. The recess PH ₁ is formed in a state where it does not interfere with the pin VP and the exhaust port VC ₁ .

As shown in FIG. 4A, a pair of second liquid repellent plates 28b ₁ , 28b ₂ , 28b ₃ , 28b ₄ has a pair of surfaces in the vicinity of both ends in the longitudinal direction. A cylindrical positioning pin PC is projected. Corresponding to these positioning pins PC, as shown in FIG. 4B, the regions 29b ₁ , 29b ₂ , 29b ₃ , 29b ₄ on the upper surface of the wafer table WTB are in the vicinity of both ends in the longitudinal direction. In a state where the pair of circular recesses PH ₂ , PH ₃ , PH ₄ , PH ₅ having a slightly larger diameter than the positioning pin PC do not interfere with the pin VP and the exhaust port VC _j (j = ₂ , ₃ , ₄ , 5), Each is formed.

As can be seen from the above description and FIG. 3, the first liquid repellent plate 28 a closes the region 29 a of the table main body 29, and the outer peripheral edge is on the upper surface of the convex portion that divides the outer peripheral portion of the first region. It is fixed to the table main body 29 in a state where it partially hangs over the entire periphery. The second liquid repellent plate 29b ₁ ~29b ₄ is a region 29b ₁ ~29b ₄ of table body 29 closed respectively, and within each of the outer peripheral edge, on the side adjacent to at least a first liquid repellent plate 28a side Is fixed to the wafer table WTB in a state where it hangs on the upper surface of the convex portion that divides the outer peripheral portion of the region 29a. In the state after the attachment, a first liquid repellent plate 28a and each of the second liquid repellent plate 28b ₁ ~28b _4, between each adjacent liquid repellent plates, to form a predetermined clearance, and as a whole Then, the substantially same surface that is apparently integrated, which is the upper surface of wafer table WTB, is formed (see FIG. 2). The first liquid repellent plate 28a also forms a predetermined clearance with the wafer W placed on the wafer holder WH, and forms substantially the same surface as a whole. Here, the predetermined clearance is set to a gap (for example, 0.1 mm to 0.3 mm) that does not allow the liquid Lq to enter and allows each liquid repellent plate to be individually installed.

  As shown in FIGS. 3 and 4A, a rectangular notch is provided at the + Y side end of the first liquid repellent plate 28a. The first liquid repellent plate 28a is attached to the wafer stage WST in a state where the notches are in contact with the three sides of the measurement plate 30 on the wafer table WTB (see FIG. 2).

  As shown in FIG. 2, a reference mark FM is arranged in the center of the measurement plate 30, and a pair of aerial image measurement slit patterns (slit measurement patterns) SL are formed so as to sandwich the reference mark FM. ing. Corresponding to each aerial image measurement slit pattern SL, there is provided a light transmission system (not shown) for guiding the illumination light IL passing therethrough to the outside of wafer stage WST (a light receiving system provided in measurement stage MST described later). It has been.

Here, a method of attaching the liquid repellent plates 28a, 28b _{1 to} 28b _{4 to} the table body 29 will be described. Here, as an example, a method of attaching the second liquid repellent plate 28b ₄ will be described.

First, as shown by an arrow in FIG. 5A, the operator brings the second liquid repellent plate 28b ₄ closer to the table body 29 so as to close the region 29b ₄ from above, and the second liquid repellent plate the lower surface of the pair of positioning pins PC of 28b _4, the pair of recesses PH ₅ formed in the region 29 b _4, to insert respectively. As a result, as shown in FIG. 5B, the second liquid repellent plate 28b ₄ is attached in a state of being positioned in a predetermined positional relationship with respect to the region 29b _{4 on} the upper surface of the table main body 29.

Next, the operator gives a command to the main controller 20 to start the operation of the vacuum pump 43E. As a result, the gas in the space formed between the second liquid repellent plate 28b ₄ and the annular convex portion defining the region 29b ₄ is exhausted to the outside via the exhaust port VC ₅ and the vacuum exhaust pipe line. The inside of the space becomes negative pressure, and the second liquid repellent plate 28b ₄ is sucked and held by a pin chuck composed of a large number of pins VP and fixed to the table body 29.

The other second liquid repellent plates 28b ₁ , 28b ₂ , 28b ₃ are paired by the operator so as to project from the lower surface of each second liquid repellent plate, similarly to the second liquid repellent plate 28b _4. The pin PC is attached to the upper surface of the table main body 29 in a state of being inserted into a pair of circular recesses PH ₂ , PH ₃ , PH ₄ formed in the regions 29 b ₁ , 28 b ₂ , 29 b ₃ . 5A and 5B show a procedure for attaching the _second liquid repellent plates 28b ₁ and 28b ₂ among them.

Then, according to an instruction of the operator, the main controller 20, a vacuum pump 43B~43D starts operation respectively, in the same manner as described above, the second liquid repellent plate 28b ₁ ~28b ₃ is corresponding regions 29 b ₁ ~ It is sucked and held by a pin chuck composed of a large number of pins VP provided on 29 b ₃ and fixed to the table body 29.

Although not shown, the first liquid repellent plate 28a is formed by the operator with four positioning pins PC projecting on the lower surface thereof in the region 29a in the same manner as the second liquid repellent plate 28b ₄ described above. the circular recess PH ₁ at four positions which are, in a state of being inserted respectively attached to the upper surface of the table main body 29. Then, in response to the operator's instruction, the main controller 20 starts the operation of the vacuum pump 43A, and the first liquid repellent plate 28a has a large number of pins VP provided in the corresponding region 28a in the same manner as described above. It is adsorbed and held by a pin chuck made of and fixed to the table main body 29.

Each of the second liquid repellent plates 28b _{1 to} 28b ₄ is formed with a scale for an encoder system to be described later. More specifically, as shown in FIG. 4A, Y scales 39Y ₁ and 39Y ₂ are formed on the second liquid repellent plates 28b ₁ and 28b ₂ , respectively. The Y scales 39Y ₁ and 39Y ₂ are, for example, reflective type gratings (for example, diffraction gratings) in which the Y axis direction is a periodic direction in which grid lines 38 having the X axis direction as the longitudinal direction are arranged at a predetermined pitch in the Y axis direction. ). Similarly, X scales 39X ₁ and 39X ₂ are formed on the second liquid repellent plates 28b ₃ and 28b ₄ , respectively. The X scales 39X ₁ and 39X ₂ are, for example, reflection type gratings (for example, diffraction gratings) in which the X-axis direction is a periodic direction in which grid lines 37 having a longitudinal direction in the Y-axis direction are arranged in the X-axis direction at a predetermined pitch. ).

  The pitch of the grid lines 37 and 38 is set to 1 μm, for example. In FIG. 4A and other figures, the pitch of the grating is shown larger than the actual pitch for convenience of illustration.

  In order to protect the diffraction grating, it is also effective to cover it with a glass plate having a low thermal expansion coefficient having liquid repellency. Here, as the glass plate, a glass plate having the same thickness as that of the wafer, for example, a thickness of 1 mm can be used, and a wafer on which the surface of the glass plate is placed on the first liquid repellent plate 28a and the wafer holder WH. It is installed on the upper surface of wafer table WTB so as to be the same height (level) as the surface. In this case, a liquid repellent coating for the immersion liquid Lq is applied to the surface of the glass plate.

  Further, as shown in FIG. 2, a reflecting surface 17a and a reflecting surface 17b used in an interferometer system to be described later are formed on the −Y end surface and the −X end surface of the wafer table WTB.

  As shown in FIG. 1, the measurement stage MST includes a stage main body 92 that is driven in an XY plane by a linear motor (not shown) and the like, and a measurement table MTB mounted on the stage main body 92. The measurement stage MST is configured to be driven in at least three degrees of freedom (X, Y, θz) with respect to the base board 12 by a drive system (not shown).

  In FIG. 10, a stage drive system 124 including a drive system for wafer stage WST and a drive system for measurement stage MST is shown.

  Various measurement members are provided on the measurement table MTB (and the stage main body 92). As this measuring member, for example, as shown in FIG. 6, an illuminance unevenness sensor 94, an aerial image measuring instrument 96, a wavefront aberration measuring instrument 98, an illuminance monitor (not shown), and the like are provided. Further, the stage main body 92 is provided with a pair of light receiving systems (not shown) in an arrangement facing the above pair of light sending systems (not shown). In the present embodiment, each aerial image measurement slit pattern SL of measurement plate 30 on wafer stage WST is measured in a state where wafer stage WST and measurement stage MST are close to each other within a predetermined distance in the Y-axis direction (including a contact state). An aerial image measuring device 45 (see FIG. 10) is configured in which the transmitted illumination light IL is guided by each light transmission system (not shown) and received by a light receiving element of each light receiving system (not shown) in the measurement stage MST. The

  Further, reflection surfaces 19a and 19b for interferometers are formed on the + Y end surface and the −X end surface of the measurement table MTB.

  As shown in FIG. 6, a fiducial bar (hereinafter abbreviated as “FD bar”) 46 extending in the X-axis direction is attached to the −Y side surface of the measurement table MTB. Reference gratings (for example, diffraction gratings) 52 having a periodic direction in the Y-axis direction are formed in the vicinity of one end and the other end in the longitudinal direction of the FD bar 46 in a symmetrical arrangement with respect to the center line CL. . A plurality of reference marks M are formed on the upper surface of the FD bar 46. As each reference mark M, a two-dimensional mark having a size detectable by an alignment system described later is used. The surface of the FD bar 46 and the surface of the measurement table MTB are also covered with a liquid repellent film.

In the exposure apparatus 100 of the present embodiment, as shown in FIGS. 7 and 8, the detection center is located at a position a predetermined distance from the optical axis AX of the projection optical system PL to the −Y side on the reference axis LV. A primary alignment system AL1 is provided. Primary alignment system AL1 is fixed to the lower surface of the main frame (not shown). As shown in FIG. 8, secondary alignment systems AL2 ₁ and AL2 _{2 in} which detection centers are arranged almost symmetrically with respect to the reference axis LV on one side and the other side in the X-axis direction across the primary alignment system AL1. , AL2 ₃ and AL2 ₄ are provided. The secondary alignment systems AL2 _{1 to} AL2 ₄ are fixed to the lower surface of the main frame (not shown) via a movable support member, and the X-axis is used using the drive mechanisms 60 _{1 to} 60 ₄ (see FIG. 10). The relative positions of these detection areas can be adjusted with respect to the direction.

In the present embodiment, for example, an image processing type FIA (Field Image Alignment) system is used as each of the alignment systems AL1, AL2 _{1 to} AL2 ₄ . Imaging signals from each of the alignment systems AL1, AL2 _{1 to} AL2 ₄ are supplied to the main controller 20 via a signal processing system (not shown).

  In exposure apparatus 100 of the present embodiment, as shown in FIG. 1, wafer interferometer 16 that measures the position of wafer stage WST in the direction of five degrees of freedom (X, Y, θx, θy, θz), and a measurement stage An interferometer system 118 (see FIG. 10) is provided, including an interferometer 18 that measures the position of at least three degrees of freedom (X, Y, θz) in the MST. Wafer interferometer 16 projects an interferometer beam (length measuring beam) onto reflecting surfaces 17a and 17b. The interferometer 18 projects an interferometer beam (length measurement beam) on the reflecting surfaces 19a and 19b. As the interferometer system 118, the one disclosed in the pamphlet of International Publication No. 2007/097379 may be adopted to measure the position of wafer stage WST in the 6-degree-of-freedom direction. The measurement result of the interferometer system 118 is supplied to the main controller 20.

  In the present embodiment, position information (including rotation information in the θz direction) of wafer stage WST (wafer table WTB) in the XY plane is mainly measured using encoder system 150 described later. Interferometer system 118 is used when wafer stage WST is positioned outside the measurement area of encoder system 150 (for example, near the unloading position or the loading position). The interferometer system 118 is supplementarily used when correcting (calibrating) long-term fluctuations in the measurement results of the encoder system 150 (for example, due to deformation of the scale over time). Of course, interferometer system 118 and encoder system 150 may be used in combination to measure all position information of wafer stage WST (wafer table WTB).

  In exposure apparatus 100 of the present embodiment, a plurality of heads constituting encoder system 150 for measuring position (X, Y, θz) of wafer stage WST in the XY plane independently of interferometer system 118. A unit is provided.

As shown in FIG. 7, four head units 62A, 62B, 62C, and 62D are arranged on the + X side, + Y side, -X side of the nozzle unit 32, and -Y side of the primary alignment system AL1, respectively. ing. Further, as shown in FIG. 8, head units 62E and 62F are respectively arranged on both outer sides in the X-axis direction of the alignment systems AL1, AL2 _{1 to} AL2 ₄ . These head units 62A to 62F are fixed in a suspended state to a main frame (not shown) that holds the projection unit PU via support members.

As shown in FIG. 8, each of the head units 62A and 62C includes a plurality of (here, five) Y heads 65 _{1 to} 65 ₅ and Y heads 64 ₁ to 64 ₅ . Here, the Y heads 65 _{2 to} 65 ₅ and the Y heads 64 ₁ to 64 ₄ are spaced by a distance WD on a straight line (hereinafter referred to as a reference axis) LH parallel to the X axis orthogonal to the optical axis AX and the reference axis LV. Is arranged in. Y heads 65 ₁ and Y head 64 ₅ are disposed on the -Y side position of a predetermined distance apart nozzle units 32 in the -Y direction from the reference axis LH. The distance in the X-axis direction between the Y heads 65 ₁ and 65 _{2 and} between the Y heads 64 ₄ and 64 ₅ is also set to WD. The Y heads 65 _{1 to} 65 ₅ and the Y heads 64 ₅ to 64 ₁ are disposed symmetrically with respect to the reference axis LV. Hereinafter, Y heads 65 _{1 to} 65 ₅ and Y heads 64 ₁ to 64 ₅ are also referred to as Y head 65 and Y head 64, respectively, as necessary.

The head unit 62A uses a Y scale 39Y ₁ to measure a Y-axis position (Y position) of the wafer stage WST (wafer table WTB) in the Y-axis direction (Y-lens here) 70A (FIG. 10). To configure). Similarly, head unit 62C uses the Y scales 39Y _2, constitute a Y linear encoder 70C of wafer stage WST multiview that measures the Y position of the (wafer table WTB) (here 5 eyes) (see FIG. 10) To do. In the following, the Y linear encoder is abbreviated as “Y encoder” or “encoder” as appropriate.

Here, the interval WD in the X-axis direction of the five Y heads 65 and 64 (more precisely, the projection points on the scale of the measurement beams emitted by the Y heads 65 and 64) provided in the head units 62A and 62C, respectively, is The Y scales 39Y ₁ and 39Y ₂ are set slightly narrower than the width in the X-axis direction (more precisely, the length of the grid lines 38). Therefore, for example, at the time of exposure, at least one of the five Y heads 65 and 64 always faces the corresponding Y scales 39Y ₁ and 39Y ₂ (projects a measurement beam).

As shown in FIG. 8, the head unit 62 </ b> B includes a plurality (four in this case) of X heads 66 _{5 to} 66 ₈ arranged on the reference axis LV at intervals WD. Further, head unit 62D has a plurality of on reference axis LV are spaced WD (four in this case) and a X heads 66 ₁ to 66 _4. Hereinafter, the X heads 66 _{5 to} 66 ₈ and the X heads 66 _{1 to} 66 ₄ are also referred to as the X head 66 as necessary.

The head unit 62B uses the X scale 39X ₁ to measure the position (X position) of the wafer stage WST (wafer table WTB) in the X-axis direction (here, four eyes) X linear encoder 70B (FIG. 10). Further, head unit 62D uses the X scale 39X _2, multiview that measures the X-position of wafer stage WST (wafer table WTB) (here 4 eyes) constituting the X linear encoder 70D (refer to FIG. 10) . In the following, the X linear encoder is abbreviated as “encoder” as appropriate.

Here, the interval WD in the Y-axis direction between adjacent X heads 66 (more precisely, projection points on the scale of the measurement beam emitted by the X head 66) included in the head units 62B and 62D is the X scale 39X ₁ , (more precisely, the length of the grating lines 37) 39X ₂ in the Y-axis direction of the width is set narrower than. The distance between the most + Y side X heads 66 ₄ of the most -Y side of the X heads 66 ₅ and the head unit 62D of the head unit 62B is the movement of the Y-axis direction of wafer stage WST, between the two X heads The width of the wafer table WTB is set to be narrower than the width in the Y-axis direction so that it can be switched (connected). Therefore, for example, at the time of exposure, at least one of the X heads 66 included in the head units 62B and 62D always faces the corresponding X scale (39X ₁ or 39X ₂ ) (projects a measurement beam). .

Head unit 62E, as shown in FIG. 8, and a Y head 67 _{1-67 4} a plurality of (four in this case). Here, the three Y heads 67 _{1 to} 67 ₃ are arranged on the −X side of the secondary alignment system AL2 ₁ on a straight line parallel to the X axis perpendicular to the reference axis LV at the detection center of the alignment system AL1 (hereinafter referred to as a reference). (Referred to as an axis) are arranged on the LA at substantially the same interval as the interval WD. Y head 67 _4, from the reference axis LA in the + Y direction are disposed on the + Y side of secondary alignment system AL2 ₁ a predetermined distance away. The distance in the X-axis direction between the Y heads 67 ₃ and 67 ₄ is also set to WD.

Head unit 62F is equipped with a Y heads 68 ₁ to 68 ₄ of a plurality (four in this case). These Y heads 68 ₁ to 68 _4, with respect to the reference axis LV, is disposed on the Y head 67 _{4-67 1} and symmetrical position. Hereinafter, if necessary, the Y heads _67i to 674 ₄ and Y heads 68 ₁ to 68 _4, each describing both Y heads 67 and Y heads 68.

At the time of alignment measurement, at least one Y head 67 and 68 faces the Y scales 39Y ₂ and 39Y ₁ , respectively. The Y position (and θz rotation) of wafer stage WST is measured by Y heads 67 and 68 (that is, Y encoders 70E and 70F constituted by Y heads 67 and 68).

In the present embodiment, the Y heads 67 ₃ and 68 ₂ adjacent to the secondary alignment systems AL2 ₁ and AL2 ₄ in the X-axis direction are used as a pair of reference grids of the FD bar 46 when measuring the baseline of the secondary alignment system. The Y position of the FD bar 46 is measured at the position of each reference grating 52 by the Y heads 67 ₃ and 68 ₂ that face each other and the pair of reference gratings 52. In the following, encoders composed of Y heads 67 ₃ and 68 ₂ that face the pair of reference gratings 52 are respectively Y linear encoders (also abbreviated as “Y encoder” or “encoder” where appropriate) 70E ₂ and 70F ₂ ( This is referred to as FIG. For identification purposes, Y encoders composed of Y heads 67 and 68 facing Y scales 39Y ₂ and 39Y ₁ are referred to as Y encoders 70E ₁ and 70F ₁ .

The measurement values of the six linear encoders 70A to 70F described above are supplied to the main controller 20, and the main controller 20 includes three of the linear encoders 70A to 70D or the linear encoders 70E ₁ , 7F ₁ , 70B and 70D. The position of the wafer table WTB in the XY plane is controlled based on the three measured values, and the θz direction of the FD bar 46 (measurement stage MST) is determined based on the measured values of the linear encoders 70E ₂ and 70F _2. Control the rotation of

  As each encoder head, for example, an interference type encoder head disclosed in International Publication No. 2007/097379 is used. In this type of encoder head, two measurement lights are projected onto a corresponding scale, each return light is combined with one interference light and received, and the intensity of the interference light is measured using a photodetector. Based on the intensity change of the interference light, the displacement in the measurement direction of the scale (period direction of the diffraction grating) is measured.

As shown in FIGS. 7 and 9, the exposure apparatus 100 according to the present embodiment includes a multipoint focal position detection system (90a, 90a) for measuring the surface position of the entire surface of the wafer W placed on the wafer stage WST. 90b) and a plurality of Z heads (72a to 72d, 74 ₁ to 74 ₅ , 76 _{1 to} 76 ₅ ) constituting a surface position measurement system 180 for measuring the position of the wafer stage WST in the Z-axis direction and the tilt direction. Is provided. As shown in FIG. 7, the Z head is connected to the main controller 20 via a signal processing / selecting device 170 constituting the surface position measuring system 180. Note that details of the multipoint focal position detection system and the surface position measurement system 180 are disclosed in the pamphlet of International Publication No. 2007/097379, and thus detailed description thereof is omitted. Further, in FIGS. 7 and 9, etc., a plurality of detection points irradiated with the detection beam are not individually illustrated, and are elongated detection regions (beam regions) extending in the X-axis direction between the irradiation system 90a and the light receiving system 90b. ) Shown as AF.

  FIG. 10 shows the main configuration of the control system of the exposure apparatus 100. This control system is mainly configured of a main control device 20 composed of a microcomputer (or a workstation) for overall control of the entire apparatus. In FIG. 10, various sensors provided on the measurement stage MST such as the illuminance unevenness sensor 94, the aerial image measuring device 96, and the wavefront aberration measuring device 98 described above are collectively shown as a sensor group 99.

In exposure apparatus 100 of the present embodiment configured as described above, wafer stage WST and measurement stage MST are performed in accordance with the same procedure as that disclosed in the above-mentioned embodiment of International Publication No. 2007/097379. The following series of processing operations using and are performed. That is,
a) When the wafer stage WST is at the unloading position UP shown in FIG. 7, when the wafer W is unloaded and moved to the loading position LP shown in FIG. 7, a new wafer W is placed on the wafer table WTB. To be loaded. In the vicinity of the unloading position UP and loading position LP, the position of wafer stage WST with six degrees of freedom is controlled based on the measurement value of interferometer system 118.

In parallel with the wafer exchange described above, the baseline measurement of the secondary alignment systems AL2 _{1 to} AL2 ₄ is performed. This baseline measurement is performed in a state in which the θz rotation of the FD bar 46 (measurement stage MST) is adjusted based on the measurement values of the encoders 70E ₂ and 70F ₂ described above, similarly to the method disclosed in the above international pamphlet. The alignment marks AL1 and AL2 _{1 to} AL2 ₄ are used to simultaneously measure the reference mark M on the FD bar 46 in each field of view.
b) After completion of the wafer exchange and the baseline measurement of the secondary alignment systems AL2 _{1 to} AL2 ₄ , the base of the prime alignment system AL1 that moves the wafer stage WST and detects the reference mark FM of the measurement plate 30 by the primary alignment system AL1. The first half of the line check is performed. Around this time, the origins of the encoder system 150 and the interferometer system 118 are reset (reset).
c) Thereafter, while measuring the position of the wafer stage WST in the direction of 6 degrees of freedom using the encoder system 118 and the Z heads 72a to 72d, the alignment systems AL1, AL2 _{1 to} AL2 ₄ are used to measure a plurality of positions on the wafer W. Alignment measurement for detecting alignment marks in the sample shot area is performed, and in parallel with this, focus mapping (wafer W based on the measurement values of the Z heads 72a to 72d) using the multipoint AF system (90a, 90b) is performed. Measurement of the surface position (Z position) information). Here, after the alignment measurement is started and before the focus mapping is started, the wafer stage WST and the measurement stage MST are in a scrum state, and the wafer stage WST for alignment measurement and focus mapping moves in the + Y direction, Liquid immersion area 14 is transferred from measurement stage MST to wafer stage WST. Then, when the measurement plate 30 reaches just below the projection optical system PL, the pair of alignment marks on the reticle R is measured by the slit scan method using the aerial image measurement device 45, and the latter half of the baseline check of the primary alignment system AL1. Is performed.
d) Thereafter, alignment measurement and focus mapping are continued.
e) When the alignment measurement and focus mapping are completed, the wafer is obtained by the step-and-scan method based on the position information of each shot area on the wafer obtained as a result of the alignment measurement and the latest alignment system baseline. A plurality of shot areas on W are exposed, and a reticle pattern is transferred. During the exposure operation, focus leveling control of the wafer W is performed based on information obtained by focus mapping. The Z and θy of the wafer being exposed are controlled based on the measured values of the Z heads 74 _i and 76 _j , while θx is controlled based on the measured value of the Y interferometer 16.

By the way, as well as the distortion of the Y scales 39Y ₁ , 39Y ₂ , 39X ₁ , 39X ₂ and the irregularities on the surface thereof, the contamination of the second liquid repellent plates 28b _{1 to} 28b ₄ is also affected by the encoder system 150 and the surface position sensor. It becomes a cause of generation of measurement errors of the system 180. In the exposure apparatus 100 of the present embodiment, since the liquid immersion area 14 frequently travels on the scale, the liquid Lq forming the liquid immersion area 14 is expected to adhere or remain. Therefore, it is necessary to replace the second liquid repellent plates 28b _{1 to} 28b ₄ as appropriate. Also, liquid immersion area 14, in particular, X scales 39X ₁ to traffic frequently on, only the second liquid repellent plate 28b ₃ of X scales 39X ₁ is formed, frequently than other liquid repellent plate It needs to be replaced. This is primarily deposited liquid immersion area 14 is on the surface of the second liquid repellent plate 28b _3, it remains, thereby, compared with cleaning or washing of the second liquid repellent plate 28b _3, the other liquid-repellent plate Because it must be done frequently.

In the present embodiment, the liquid repellent plate 28 is composed of five liquid repellent plates 28a, 28b _{1 to} 28b ₄ and is individually vacuum-adsorbed to the table main body 29 using individual vacuum pumps. Only one necessary liquid repellent plate (for example, the second liquid repellent plate 28b ₃ ) can be replaced without attaching or removing another liquid repellent plate. Therefore, running cost can be suppressed.

Here, when the liquid repellent plate replacement process refers to, for example, the second liquid repellent plate 28b ₃ , the second liquid repellent plate 28b ₃ is removed from the upper surface of the table main body 29 and cleaned (cleaning is performed after washing). It is meant to be mounted again on the table main body 29. In this case, after mounting the cleaned second liquid repellent plate 28b ₃ on the table main body 29 on the table main body 29, the position of the liquid repellent plate is measured again, whereby the encoder system 150 and the surface due to the scale are measured. It is necessary to update the error correction parameter of the position measurement system 180. In this case, since it is only necessary to measure the position of the second liquid repellent plate 28b ₃ mounted again, the time required for the measurement and update of the error correction parameter is short. Thereby, the maintenance time can be shortened.

Incidentally, the second liquid repellent plate 28b _3, may be replaced with a new second liquid repellent plate 28b _3. In this case, the scale formed on the new second liquid repellent plate 28b ₃ unevenness, distortion, installation position, etc., is necessary to update the correction parameters of the encoder system 150 and surface position measurement system 180 due to the scale Yes, various measurements are necessary for this purpose. However, even in this case, in this embodiment, the measurement and the error correction parameter need only be updated for the replaced second liquid repellent plate 28b ₃ (scale). Can be shortened compared to the case of updating the error correction parameter for all scales.

The other second liquid repellent plates 28b ₁ , 28b ₂ , 28b ₄ may be cleaned or replaced with new second liquid repellent plates.

As described above in detail, according to the exposure apparatus 100 of the present embodiment, the plate (liquid repellent plate) 28 constituting the upper surface of the wafer table WTB is positioned on the outer periphery of the first liquid repellent plate 28a located in the center. and a four second liquid repellent plates 28b ₁ ~28b ₄ Metropolitan to. Scales used for measuring the position of wafer stage WST using an encoder, that is, X scales 39X ₁ and 39X ₂ and Y scales 39Y ₁ and 39Y ₂ are formed on each of the four outer peripheral portions. The first liquid repellent plate 28a and four second liquid repellent plate 28b ₁ ～28B ₄ is a separate vacuum pump 43A, 43B, 43C, 43D, the 43E, by vacuum suction through a separate vacuum exhaust path, It is fixed to the upper surface of wafer table WTB. Therefore, for example, it is possible to replace only the second liquid repellent plate 28b ₃ on which the scale 39X _{1 which} is easily dirty and requires frequent replacement is formed without attaching or removing another liquid repellent plate. Therefore, not only the cost for replacement can be suppressed, but also the measurement error of the encoder due to the scale can be easily corrected, so that high throughput can be maintained.

In the above-described embodiment, two or four positioning pins PC are provided on each of the liquid repellent plates 28a, 28b _{1 to} 28b ₄ constituting a part of the plate 28, and the corresponding circular recess PHi (i = 1). , 2, 3, 4, 5) are provided on the upper surface of the table body 29, but the present invention is not limited to this. In short, it is only necessary to uniquely fix the position and orientation of each liquid repellent plate. Therefore, it is sufficient to provide at least two positioning pins for one liquid repellent plate. Of course, three or more positioning pins may be provided. Further, a positioning pin PC may be provided on the upper surface of the table body 29, and a recess may be provided on the lower surface of the liquid repellent plate facing the positioning pin PC.

The configuration of the plate (liquid repellent plate) 28 that constitutes the upper surface of the wafer table WTB of the above embodiment is merely an example, and the present invention is of course not limited to this. In the above embodiment, the first liquid repellent plate 28a, 4 single and second liquid repellent plates 28b ₁ ~28b ₄ is has been vacuum suction table body 29 separately, not limited thereto, for example, the most frequently Only the second liquid repellent plate 28b ₃ that is expected to be replaced is vacuum-adsorbed by another vacuum exhaust system from the other liquid repellent plates 28a and 28b ₁ , 28b ₂ , 28b _4. Also good. In this case, all of the liquid repellent plates 28a and 28b ₁ , 28b ₂ , 28b ₄ may be vacuum-sucked by the same vacuum exhaust system, or any combination is vacuum-sucked separately by a plurality of vacuum exhaust systems. It may be a configuration.

For example, as shown in FIG. 11A, the second liquid repellent plate 28c ₁ on which the Y scale 39Y ₁ and the X scale 39X ₁ are formed, the Y scale 39Y ₂ and the X scale 39X ₂ are formed. The plate (liquid repellent plate) 28 may be constituted by three liquid repellent plates, the second liquid repellent plate 28c ₂ and the first liquid repellent plate 28a similar to the above embodiment. In this case, as shown in FIG. 11B, on the upper surface of the table body 29, there are three regions 29a, 29c ₁ , 29c ₂ corresponding to the three liquid repellent plates 28a, 28c ₁ , 28c ₂ , respectively. Provided. Each of the three regions 29a, 29c ₁ and 29c ₂ is individually provided with at least one exhaust port VC connected to a large number of pins VP and individual vacuum pumps. As a result, the Y scale 39Y ₁ and the X scale 39X ₁ and the Y scale 39Y ₂ and the X scale 39X ₂ can be exchanged separately.

In addition, the first liquid repellent plate 28a is not necessarily prepared separately from the second liquid repellent plate on which the scale is formed. For example, as shown in FIG. 12A, a liquid repellent plate 28d on which a Y scale 39Y ₁ and an X scale 39X ₁ are formed, a liquid repellent plate 28e on which a Y scale 39Y ₂ and an X scale 39X ₂ are formed, The plate (liquid repellent plate) 28 may be constituted by the two liquid repellent plates. In this case, as shown in FIG. 12B, two regions 29d and 29e corresponding to the two liquid repellent plates 28d and 28e are provided on the upper surface of the table body 29, respectively. Each of the two regions is individually provided with a number of pins VP and at least one exhaust port VC connected to a separate vacuum pump. Also in this case, the Y scale 39Y ₁ and the X scale 39X ₁ and the Y scale 39Y ₂ and the X scale 39X ₂ can be exchanged separately. Furthermore, since the plate 28 is configured with a small number of members, the number of vacuum pumps, exhaust ports VC, and vacuum exhaust pipes connected to the exhaust ports VC can be reduced.

In the above embodiment and the modifications, by vacuum suction, the liquid repellent plate 28a, it is assumed to fix the 28b ₁ ~28b ₄ on the upper surface of the table body 29, not limited to this, for example mechanically fixed It is also good to do. The configuration of the fixing means is not limited as long as each of the liquid repellent plates 28a, 28b _{1 to} 28b ₄ is individually installed at a predetermined position and orientation.

  In the above embodiment, the case where the present invention is applied to the exposure apparatus of the step-and-scan method and the immersion exposure method is described. However, the present invention is not limited to this, and the present invention is also applied to a stationary exposure apparatus such as a stepper. Is applicable. Even in the case of a stepper or the like, the same effect can be obtained because the position of the stage on which the object to be exposed is mounted can be measured using the encoder as in the above embodiment. The present invention can also be applied to a non-immersion type exposure apparatus. The present invention can also be applied to a step-and-stitch reduction projection exposure apparatus, a proximity exposure apparatus, or a mirror projection aligner that synthesizes a shot area and a shot area. In addition, as disclosed in, for example, US Pat. No. 6,590,634, US Pat. No. 5,969,441, US Pat. No. 6,208,407, a plurality of wafers. The present invention can also be applied to a multi-stage type exposure apparatus provided with a stage.

  In addition, the projection optical system in the exposure apparatus of the above embodiment may be not only a reduction system but also an equal magnification and an enlargement system, and the projection optical system PL may be not only a refraction system but also a reflection system or a catadioptric system. The projected image may be either an inverted image or an erect image. In addition, the illumination area and the exposure area described above are rectangular in shape, but the shape is not limited to this, and may be, for example, an arc, a trapezoid, or a parallelogram.

The light source of the exposure apparatus of the above embodiment is not limited to the ArF excimer laser, but is a KrF excimer laser (output wavelength 248 nm), F ₂ laser (output wavelength 157 nm), Ar ₂ laser (output wavelength 126 nm), Kr ₂ laser ( It is also possible to use a pulse laser light source with an output wavelength of 146 nm, an ultrahigh pressure mercury lamp that emits a bright line such as g-line (wavelength 436 nm), i-line (wavelength 365 nm), and the like. A harmonic generator of a YAG laser or the like can also be used. In addition, as disclosed in, for example, US Pat. No. 7,023,610, a single wavelength laser beam in an infrared region or a visible region oscillated from a DFB semiconductor laser or a fiber laser is used as vacuum ultraviolet light. For example, a harmonic that is amplified by a fiber amplifier doped with erbium (or both erbium and ytterbium) and wavelength-converted into ultraviolet light using a nonlinear optical crystal may be used.

  In the above embodiment, it is needless to say that the illumination light IL of the exposure apparatus is not limited to light having a wavelength of 100 nm or more, and light having a wavelength of less than 100 nm may be used. For example, the present invention is also suitable for an EUV exposure apparatus that uses EUV (Extreme Ultraviolet) light in a soft X-ray region (for example, a wavelength region of 5 to 15 nm) as exposure light and uses an all-reflection reduction optical system and a reflective mask. Can be applied. In the EUV exposure apparatus, it is necessary to fix the lattice member to the wafer stage main body by means other than vacuum suction. In addition, the present invention can be applied to an exposure apparatus using a charged particle beam such as an electron beam or an ion beam.

  In the above-described embodiment, a light transmission mask (reticle) in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. Instead of this reticle, For example, as disclosed in US Pat. No. 6,778,257, an electronic mask (variable shaping mask, which forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed, as disclosed in US Pat. No. 6,778,257. For example, a non-light emitting image display element (spatial light modulator) including a DMD (Digital Micro-mirror Device) may be used.

  Further, for example, the present invention can be applied to an exposure apparatus (lithography system) that forms line and space patterns on a wafer by forming interference fringes on the wafer.

  Further, as disclosed in, for example, US Pat. No. 6,611,316, two reticle patterns are synthesized on a wafer via a projection optical system, and one scan exposure is performed on one wafer. The present invention can also be applied to an exposure apparatus that performs double exposure of shot areas almost simultaneously.

  The apparatus for forming a pattern on an object is not limited to the above-described exposure apparatus (lithography system), and the present invention can also be applied to an apparatus for forming a pattern on an object by, for example, an inkjet method.

  Note that the object on which the pattern is to be formed in the above embodiment (the object to be exposed to the energy beam) is not limited to the wafer, but other objects such as a glass plate, a ceramic substrate, a film member, or a mask blank. But it ’s okay.

  The use of the exposure apparatus is not limited to the exposure apparatus for semiconductor manufacturing. For example, an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern onto a square glass plate, an organic EL, a thin film magnetic head, an image sensor ( CCDs, etc.), micromachines, DNA chips and the like can also be widely applied to exposure apparatuses. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., glass substrates or silicon wafers, etc. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern.

  An electronic device such as a semiconductor element includes a step of designing a function / performance of the device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and the exposure apparatus (pattern forming apparatus) of the above-described embodiment. ) A lithography step for transferring a mask (reticle) pattern onto a wafer, a development step for developing the exposed wafer, an etching step for removing exposed members other than the portion where the resist remains by etching, and etching is completed. It is manufactured through a resist removal step for removing unnecessary resist, a device assembly step (including a dicing process, a bonding process, and a package process), an inspection step, and the like. In this case, in the lithography step, the exposure method described above is executed using the exposure apparatus of the above embodiment, and a device pattern is formed on the wafer. Therefore, a highly integrated device can be manufactured with high productivity.

  The exposure apparatus of the present invention is suitable for forming a pattern on an object by irradiating an energy beam. The device manufacturing method of the present invention is suitable for manufacturing an electronic device such as a semiconductor element or a liquid crystal display element. The maintenance method of the present invention is suitable for maintenance of a semiconductor exposure apparatus that requires high overlay accuracy.

It is a figure which shows schematically the structure of the exposure apparatus which concerns on one Embodiment. It is a top view which shows a wafer stage. FIG. 3 is a schematic exploded perspective view of the wafer table of FIG. 2. FIG. 4A is a diagram showing a configuration of a liquid repellent plate constituting a part of the wafer table, and FIG. 4B is a plan view showing an example of a configuration of the upper surface of the table body. FIGS. 5A and 5B are diagrams for explaining a procedure for attaching the liquid repellent plate to the table body. It is a top view which shows a measurement stage. It is a top view which shows arrangement | positioning of the stage apparatus with which the exposure apparatus of FIG. 1 is equipped, and measuring devices. It is a top view which shows arrangement | positioning of an encoder head (X head, Y head) and an alignment system. It is a top view which shows arrangement | positioning of Z head and a multipoint AF type | system | group. It is a block diagram which shows the main structures of the control system of the exposure apparatus which concerns on one Embodiment. FIG. 11A is a diagram illustrating a configuration of a liquid repellent plate according to a modified example, and FIG. 11B is a plan view illustrating a configuration of an upper surface of a table body according to the modified example. FIG. 12A is a diagram showing a configuration of a liquid repellent plate according to another modification, and FIG. 12B is a plan view showing a configuration of an upper surface of a table body according to another modification.

Explanation of symbols

8 ... local liquid immersion apparatus, 10 ... illumination system 20 ... main control unit, 39X _1, 39X ₂ ... X scales 39Y _1, 39Y ₂ ... Y scale, 50 ... stage device, 62a to 62f ... head unit 64, 65 ... Y head, 66 ... X head, 67,68 ... Y head, 70A, 70C ... Y linear encoder, 70B, 70D ... X linear encoder, 72a to 72d, 74,76 ... Z head, 90a, 90b ... multiple points AF system, 100 ... exposure device, 124 ... stage drive system, 150 ... encoder system, 170 ... signal processing / selection device, 180 ... surface position measurement system, 200 ... measurement system, PL ... projection optical system, PU ... projection unit, W ... wafer, WST ... wafer stage, WTB ... wafer table.

Claims (22)

An exposure apparatus that irradiates an energy beam to form a pattern on an object,
A movable body holding an object and movable within a predetermined plane;
A plurality of grating members each individually and detachably fixed on a surface substantially parallel to the predetermined plane on which the object of the moving body is placed, each having a diffraction grating;
An encoder system having a plurality of heads that project a measurement beam onto the lattice member and measure the position of the movable body in the predetermined plane;
A driving device for driving the movable body based on a measurement result of the encoder system;
An exposure apparatus comprising:   2. The exposure according to claim 1, wherein the plurality of lattice members are fixed to the one surface by vacuum suction through a vacuum suction path in which a system individually provided in the movable body for each lattice member is different. apparatus.   The positioning mechanism for positioning each lattice member at a predetermined position on the one surface is provided between each of the plurality of lattice members and the one surface of the movable body. The exposure apparatus according to 1 or 2.   The positioning mechanism includes a convex portion provided on one of the one surface of the movable body and the surface of each lattice member facing the one surface, and each lattice member facing the one surface of the movable body and the one surface. The exposure apparatus according to claim 3, further comprising: a concave portion provided on the other side of the first surface and into which the convex portion is fitted.   Each of the plurality of lattice members is fixed on the one surface of the movable body in a state where a predetermined clearance is formed between adjacent lattice members and substantially the same surface is formed as a whole. The exposure apparatus according to any one of 1 to 4.   6. The exposure apparatus according to claim 1, wherein at least one of the plurality of grating members includes a light-transmitting protective member that covers the diffraction grating.   The exposure apparatus according to claim 1, wherein at least two diffraction gratings having different periodic directions are formed on at least one of the plurality of grating members.   A state in which at least a part of the plurality of lattice members forms a predetermined clearance with the object placed on the one surface of the movable body and forms the same surface as the object as a whole The exposure apparatus according to claim 1, wherein the exposure apparatus is fixed on the one surface of the movable body.   In a state in which a predetermined clearance is formed at least between the object and the object and the plurality of lattice members, and substantially the same plane is formed on the one surface of the movable body, independently of the plurality of lattice members. The exposure apparatus according to claim 1, further comprising a surface member that is detachably fixed.   The exposure apparatus according to claim 9, wherein the surface member is disposed at a position surrounding the object to be placed on the one surface, and the plurality of lattice members are disposed at a position surrounding the surface member.   The exposure apparatus according to claim 9 or 10, wherein the surface member is fixed to the one surface by vacuum suction through a vacuum suction path having a system different from that of the plurality of lattice members.   The positioning part which positions the said surface member in the predetermined position on the said one surface is provided between the said surface member and the said one surface of the said mobile body as described in any one of Claims 9-11. Exposure device.   The positioning portion includes a convex portion provided on one of the one surface of the movable body and the surface of the surface member facing the one surface, one surface of the movable body, and a surface of the surface member facing the one surface. The exposure apparatus according to claim 12, further comprising: a recess provided in the other of the first and second recesses into which the protrusion is fitted.   The exposure apparatus according to claim 9, wherein a liquid repellent coat is applied to a surface of the surface member.   A pair of first diffraction gratings having a periodic direction in a first direction parallel to one axis in the predetermined plane on the one surface by fixing the plurality of grating members on the one surface of the movable body, The exposure according to any one of claims 1 to 14, wherein a pair of second diffraction gratings having a second direction parallel to another axis orthogonal to the one axis in the predetermined plane as a periodic direction are provided. apparatus.   The exposure apparatus according to any one of claims 1 to 15, wherein a liquid repellent coating is applied to the surfaces of the plurality of lattice members. An optical system for irradiating the object with the energy beam;
The exposure apparatus according to claim 1, further comprising: a liquid supply device that supplies a liquid between the optical system and the object.   The surface position measuring system which has a some head which projects a measurement beam on the lattice member, and measures a position about a direction perpendicular to the predetermined plane of the one side in a projection point of the measurement beam. The exposure apparatus according to any one of -17. A step of forming a pattern on the object using the exposure apparatus according to claim 1;
Processing the object on which the pattern is formed;
A device manufacturing method including: An exposure apparatus maintenance method for irradiating an energy beam onto an object held by a moving body moving within a predetermined plane and forming a pattern on the object,
In the predetermined plane of the movable body, each of which is individually and detachably fixed on a surface substantially parallel to the predetermined plane on which the object of the movable body is placed, and in which a diffraction grating is formed. An exposure apparatus maintenance method including a step of performing replacement processing of a part of a plurality of grating members, in which measurement beams are projected from a plurality of heads that measure positions at the head.   21. The exposure apparatus according to claim 20, wherein the replacement processing includes removing the part of the lattice member from the one surface of the moving body and cleaning it, and then mounting the lattice member again on the one surface of the moving body. Maintenance method On the one surface of the movable body, a surface member that is detachable independently of the plurality of lattice members forms a predetermined clearance at least with the object, and the object and the plurality of lattice members In a state of forming substantially the same surface together with,
The exposure apparatus maintenance method according to claim 20 or 21, further comprising a step of replacing the surface member independently of the part of the lattice members.

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