JP2014127654A - Suction apparatus, method, and exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suck a wafer without changing temperature.SOLUTION: Using a temperature sensor 128, the temperature of air ejected from a loading disk (Bernoulli cup) is measured and a temperature controller 133 is controlled according to the result of the measurement, thereby adjusting the temperature of air in a pipe 135. Thus, by using the loading unit (loading disk), a wafer can be sucked without a temperature change. In addition, by using a loading unit (loading disk), a wafer W can be loaded onto a wafer stage WST without being thermally deformed.

Description

  The present invention relates to a suction apparatus and method, and an exposure apparatus, and more particularly, a suction apparatus and method for applying a suction force to a wafer in a non-contact manner, and a wafer is loaded on a wafer stage using the suction apparatus. And an exposure apparatus for forming a pattern on the wafer.

  Conventionally, in a lithography process for manufacturing electronic devices (microdevices) such as semiconductor elements (integrated circuits, etc.), liquid crystal display elements, etc., step-and-repeat projection exposure apparatuses (so-called steppers), step-and- A scanning projection exposure apparatus (a so-called scanning stepper (also called a scanner)) or the like is used.

  Wafers exposed by these exposure apparatuses are becoming larger year by year. Currently, wafers with a diameter of 300 mm (300 mm wafers) to wafers with a diameter of 450 mm (450 mm wafers) are becoming mainstream. In the case of a 450 mm wafer, the number of dies (chips) that can be taken from one wafer is more than twice the number in the case of a current 300 mm wafer. Therefore, the manufacturing cost spent per chip can be greatly reduced.

  Since the thickness of the wafer is constant while the wafer is increased in size, it is expected that a more careful handling will be required in transferring a 450 mm wafer as compared with a 300 mm wafer. In view of this, the inventor has proposed that the wafer is placed on the wafer stage by holding the wafer in a non-contact manner by ejecting air from above to the surface of the wafer using a Bernoulli chuck (for example, a patent Reference 1). However, when a Bernoulli chuck is used, the positional deviation or the like when placing the wafer on the wafer stage may exceed an allowable limit, and the wafer is cooled (or heated) by the air ejected from the Bernoulli chuck. May be thermally deformed, and due to these, for example, alignment measurement (detection of a mark on a wafer) is expected to be difficult.

US Patent Application Publication No. 2010/0297562 No. 3-41461 specification

  The present invention has been made under the circumstances described above. From a first viewpoint, the present invention is a suction device that applies a suction force to a plate-like object in a non-contact manner, and is opposed to the object. A suction member capable of generating the suction force by forming a gas flow between the facing part and the object by the gas ejected from the ejection part. A temperature adjusting device capable of adjusting the temperature of the gas and supplying the adjusted gas to the ejection unit, a setting device for setting at least one of a flow rate and a flow velocity of the gas ejected from the ejection unit to a predetermined value, and A changing device that is provided on a gas supply path from a temperature control device to the ejection part and changes at least one of a flow rate and a flow velocity of the gas guided from the temperature control device according to the predetermined value. A suction device.

  According to this, it becomes possible to hold | maintain an object, without changing temperature.

  From a second viewpoint, the present invention is an exposure apparatus that irradiates an energy beam to form a pattern on an object, and includes a moving body that sucks and moves the object, and the suction apparatus of the present invention. An exposure apparatus that stacks the object on the moving body using the suction device.

  According to this, by using the holding device of the present invention, it is possible to load an object on a moving body without thermal deformation.

  From a third aspect, the present invention is a suction method in which a suction force is applied to a plate-like object in a non-contact manner, and is opposed to the object by a gas ejected from an ejection part that ejects gas. Generating the suction force by forming a gas flow between the part and the object, adjusting the temperature of the gas, supplying the adjusted gas to the ejection part, and ejecting from the ejection part Setting at least one of a gas flow rate and a flow velocity to a predetermined value, and changing at least one of the gas flow rate and the flow velocity according to the predetermined value on a path through which the temperature-controlled gas is supplied to the ejection unit A suction method including:

  According to this, it becomes possible to hold | maintain an object, without changing temperature.

It is a figure which shows schematically the structure of the exposure apparatus which concerns on one Embodiment. FIGS. 2A and 2B are a cross-sectional view and a bottom view, respectively, schematically showing the configuration of the loading unit and the loading disk, respectively. FIGS. 3A and 3B are diagrams showing a schematic configuration of the air supply unit and pipe switching by the electromagnetic valve. FIG. 2 is a block diagram showing a main configuration of a control system of the exposure apparatus in FIG. 1. It is a flowchart which shows the procedure of the temperature control of air. 6A to 6C are diagrams for explaining a procedure for loading a wafer onto a wafer stage using a loading unit (particularly, a procedure for holding a wafer using a loading disk) (Part 1). ~ 3). FIGS. 7A to 7C are views (Nos. 4 to 6) for explaining a procedure for loading a wafer onto a wafer stage using a loading unit. FIGS. 8A and 8B are views (Nos. 7 and 8) for explaining a procedure for loading a wafer onto a wafer stage using a loading unit. FIG. 9A and FIG. 9B are diagrams showing modified configurations (Nos. 1 and 2) of the air supply unit.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a schematic configuration of an exposure apparatus 100 according to an embodiment. The exposure apparatus 100 is a step-and-scan projection exposure apparatus, a so-called scanner. As will be described later, in the present embodiment, a projection optical system PL is provided. In the following description, a reticle and wafer are arranged in a direction perpendicular to the Z-axis direction parallel to the optical axis AX of the projection optical system PL and in a plane perpendicular to the Z-axis direction. And the direction perpendicular to the Z and Y axes is the X axis direction, and the rotation (tilt) directions around the X, Y, and Z axes are θx, θy, And the θz direction will be described.

  The exposure apparatus 100 includes an illumination system IOP, a reticle stage RST that holds a reticle R, a projection unit PU that projects a pattern image formed on the reticle R onto a wafer W coated with a sensitive agent (resist), and a wafer W. A wafer stage WST that holds and moves in the XY plane, a loading unit 120 that loads and unloads the wafer W onto and from the wafer stage WST, and a control system thereof are provided.

  The illumination system IOP includes a light source and an illumination optical system connected to the light source via a light transmission optical system, and is slit-like illumination that extends in the X-axis direction on the reticle R defined by the reticle blind (masking system). The area IAR is illuminated with substantially uniform illuminance by illumination light (exposure light) IL. The configuration of the illumination system IOP is disclosed in, for example, US Patent Application Publication No. 2003/0025890. Here, as an example, ArF excimer laser light (wavelength 193 nm) is used as the illumination light IL.

  Reticle stage RST is arranged below illumination system IOP. On reticle stage RST, reticle R having a circuit pattern or the like formed on its pattern surface is placed. The reticle R is fixed on the reticle stage RST, for example, by vacuum suction.

  The reticle stage RST can be finely driven in a horizontal plane (XY plane) by a reticle stage drive system 11 (not shown in FIG. 1, see FIG. 4) including a linear motor, for example, and also in a scanning direction (Y-axis direction). It is possible to drive within a predetermined stroke range. Position information of the reticle stage RST in the XY plane (including rotation information in the θz direction) is formed on the end face of the reticle stage RST by a reticle laser interferometer (hereinafter referred to as “reticle interferometer”) 14. Measured at a resolution of about 0.25 nm, for example. The measurement result of reticle interferometer 14 is supplied to main controller 20 (not shown in FIG. 1, see FIG. 4).

  Projection unit PU is arranged below reticle stage RST. The projection unit PU includes a lens barrel 40 and a projection optical system PL held in the lens barrel 40. As the projection optical system PL, for example, a refractive optical system including a plurality of optical elements (lens elements) arranged along the optical axis AXp 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 light IL from the illumination system IOP, the reticle R in which the first surface (object surface) of the projection optical system PL and the pattern surface are substantially coincided with each other is arranged. With the illumination light IL that has passed through the projection optical system PL (projection unit PU), a 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 projected through the projection optical system PL (projection unit PU). Is formed in a region (hereinafter also referred to as an exposure region) IA that is conjugated to the illumination region IAR on the wafer W, which is disposed on the second surface (image surface) side of the wafer W, the surface of which is 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. .

  Wafer stage WST is driven on stage base 22 with a predetermined stroke in the X-axis direction and Y-axis direction by stage drive system 24 including a linear motor and the like, and in Z-axis direction, θx direction, θy direction, and θz direction. It is driven minutely. Instead of wafer stage WST, a first stage that moves in the X-axis direction, the Y-axis direction, and the θz direction, and a second stage that finely moves in the Z-axis direction, θx direction, and θy direction on the first stage; It is also possible to use a stage apparatus comprising

  A wafer holder (not shown) is provided on wafer stage WST. The wafer W is held by vacuum suction or the like by a wafer holder (not shown). Further, CT pins 140 (see FIG. 2A) for supporting the back surface of the wafer W are provided in the wafer stage WST so as to be able to be taken in and out of a wafer holder (not shown).

  On the wafer stage WST, a reference plate FP whose surface is the same height as the surface of the wafer W is fixed. On the surface of the reference plate FP, a reference mark used for baseline measurement of the alignment detection system AS, a pair of reference marks detected by a reticle alignment detection system described later, and the like are formed.

  Position information of wafer stage WST in the XY plane (including rotation information (yaw amount (rotation amount θz in θz direction), pitching amount (rotation amount θx in θx direction), rolling amount (rotation amount θy in θy direction))) Is always measured by a laser interferometer system (hereinafter referred to as “interferometer system”) 18 via a movable mirror 16 (a reflecting surface formed on the end face of wafer stage WST) with a resolution of about 0.25 nm, for example. Is done. The measurement result is supplied to the main controller 20 (see FIG. 4). Main controller 20 controls the position of wafer stage WST in the XY plane (including rotation in the θz direction) via stage drive system 24 in accordance with the measurement result of interferometer system 18.

  Although not shown in FIG. 1, the position and the amount of tilt in the Z-axis direction on the surface of the wafer W are various in the oblique incidence method disclosed in, for example, US Pat. No. 5,448,332. It is measured by a focus sensor AF (see FIG. 4) comprising a point focus position detection system. The measurement result of the focus sensor AF is also supplied to the main controller 20 (see FIG. 4).

  An alignment detection system AS that detects alignment marks and reference marks formed on the wafer W is provided on the side surface of the lens barrel 40 of the projection unit PU. As an example of the alignment detection system AS, a mark is illuminated with broadband light such as a halogen lamp, and the mark position is measured by image processing of the mark image, which is a type of image-forming alignment sensor. An FIA (Field Image Alignment) system is used.

  In exposure apparatus 100, a pair of TTR (Through The Reticle) alignment systems using light having an exposure wavelength disclosed in, for example, US Pat. No. 5,646,413, for example, above reticle stage RST. A reticle alignment detection system 13 (not shown in FIG. 1, refer to FIG. 4) is provided. The detection signal of the reticle alignment detection system 13 is supplied to the main controller 20 (see FIG. 4).

  The loading unit 120 is disposed in the vicinity of the alignment detection system AS. A place where the loading unit 120 is disposed is called a loading position.

  2A and 2B are a cross-sectional view and a bottom view of the loading unit 120, respectively. The loading unit 120 includes a drive unit 122, a loading disk 121, an air supply unit 130 (see FIGS. 3A and 3B), and the like.

Driver 122, other the projection optical system PL (projection unit PU) drive 122 ₀ which is fixed through a frame that supports (not shown) to the vibration isolating member (not shown) to the end drive unit 122 ₀ end comprises a movable shaft 122 ₁ which is fixed to the top of the loading disk 121. Drive 122 ₀ includes a power source such as a voice coil motor or the like. Driver 122, by using the driving device 122 _0, the movable shaft 122 ₁ by driving in the direction of the white arrow (Z-axis direction), moves up and down the loading disk 121.

The loading disk 121 includes a disk-shaped disk body 123, a plurality of Bernoulli cups 124 (124 ₀ , 124 ₁ , 124 ₂ ), a gap sensor (not shown), a temperature sensor 128, three imaging elements 129, and the like.

Among the plurality of Bernoulli cups 124, one Bernoulli cups 124 ₀ at the center of the bottom surface of the disk body 123, four Bernoulli cups 124 ₁ around its, are further arranged eight Bernoulli cup 124 ₂ around their (See FIG. 2B). Pipes 125 for supplying air are connected to the plurality of Bernoulli cups 124. In the present embodiment, a common pipe 125 ₁ is connected to the Bernoulli cups 124 ₀ and 124 ₁ , and another common pipe 125 ₂ is connected to the Bernoulli cup 124 ₂ , thereby constituting an independent air supply system. The Bernoulli cup 124 (124 ₀ , 124 ₁ , 124 ₂ ) and the pipe 125 (125 ₁ ) are set so that the conductance received by the air ejected from each Bernoulli cup 124 is equal to each other at least for each independent air supply system. , 125 ₂ ). The arrangement of the Bernoulli cup is not intended to be limited to the arrangement shown in FIG. 2 (B), for example, without providing the Bernoulli cup 124 _0, 124 _1, only the Bernoulli cup 124 ₂ may be a plurality of arranged .

The plurality of Bernoulli cups 124 (124 ₀ , 124 ₁ , 124 ₂ ) use the Bernoulli effect (an effect in which the pressure of the fluid decreases as the flow velocity increases) to eject air and flow the gas around the wafer. As a result, a negative pressure (suction force) is generated between the disk main body 123 and the wafer W facing it. The loading disk 121 uses this negative pressure to suck the wafer W from above without contact. Note that the distance between the disk main body 123 and the wafer W held by the disk main body 123 is determined by the flow velocity of air ejected from each of the plurality of Bernoulli cups 124 (and the weight of the wafer W). The degree of the suction force can be adjusted as appropriate, and the wafer W is sucked and held (sucked and held) by the loading disk 121, so that movement in the Z-axis direction, θx and θy directions can be limited.

  As will be described later, the movement of the wafer W in the Z-axis direction, the θx direction, and the θy direction is restricted by being sucked by the loading disk 121, and the back surface is supported by CT pins 140 that are taken in and out of the wafer stage WST. This restricts movement in the X-axis direction, the Y-axis direction, and the θz direction.

  A plurality of gap sensors (not shown) are arranged on the bottom surface of the disc main body 123 so as to avoid the plurality of Bernoulli cups 124. The gap sensor (not shown) includes, for example, a capacitance sensor, and measures a separation distance between the loading disk 121 (disk main body 123) and the wafer W held by the loading disk 121 (disk main body 123). The result is supplied to the main controller 20. Main controller 20 determines the shape of wafer W from the measurement results from the plurality of gap sensors and the arrangement of the gap sensors.

The temperature sensor 128 includes, for example, a platinum resistor, a thermistor, and the like. The temperature sensor 128 is provided at the bottom of the disc body 123 and is disposed in the vicinity of one of the plurality of Bernoulli cups 124 (Bernoulli cup 124 ₂ in the present embodiment). The probe portion protrudes into a gap (usually a size of 200 to 400 μm) between the bottom surface of the disk main body 123 and the surface of the wafer W held by the loading disk 121. Temperature sensor 128, the temperature of the air ejected from the Bernoulli cup 124 _2, measured in better resolution than 0.01 degrees.

  The position of the temperature sensor is not particularly limited. For example, when the measurement is performed at one point on the bottom surface of the disk main body 123, the temperature sensor can be disposed at a position facing the center side of the periphery of the wafer W. In addition, the measurement points (sensors using the measurement results) may be appropriately switched by arranging them at a plurality of positions.

  The three image sensors 129 include, for example, a CCD and the like, and are fixed to the side surface of the disk main body 123 (only one image sensor 129 is shown in FIG. 2A). One of the three image sensors 129 captures the notch (V-shaped notch (not shown)) of the wafer W when the loading disk 121 (disk main body 123) holds the wafer W, and the remaining two are Images the periphery of the wafer W. The imaging results of the three imaging elements 129 are supplied to the main controller 20. Based on the imaging results, main controller 20 uses the method disclosed in, for example, U.S. Pat. No. 6,624,433, and the like to shift the position and rotation (θz) of wafer W in the X-axis direction and Y-axis direction. Rotation) error.

  In addition, a wafer transfer arm 118 for transferring a wafer between a loading position (loading unit 120) and a coater / developer (C / D (not shown)) connected in-line to the exposure apparatus 100 is attached.

FIGS. 3A and 3B show a schematic configuration of the air supply unit 130. Air supply unit 130 includes connected from the supply device 130 ₀ via the pipe 135 ₀ flow control valve 131, flow meter 132, the temperature controller 133, the solenoid valve 134, and the like.

Feeder 130 _0, clean air (referred to simply as air) which dust has been removed to supply flows into the pipe 135 _0. Flowmeter 132 measures the flow rate of air flowing through the pipe 135 _0. Flow control valve 131, according to the measurement result of the flow meter 132, and controls the air flow pipe 135 in the _0. The arrangement of the flow meter 132 and the flow control valve 131 may be reversed.

Temperature controller 133, for example, a line heater or the like for heating by contacting the air flowing through a pipe 135 in the ₀ to the heating element, to control the temperature of the air flowing through the pipe 135 _0. As described later, the temperature of the air is measured ejected from the Bernoulli cups 124 by the temperature sensor 128 provided on the loading disk 121, the temperature of the air pipe 135 ₀ by the temperature controller 133 according to the result, For example, it is controlled to 23 degrees.

Solenoid valve 134 is a kind of electric driven valve, by utilizing the magnetic force by driving the main body 134 ₀ in the direction of the black arrow, the pipe 125 or the exposure apparatus communicating pipes 135 ₀ Bernoulli cup 124 100 switch the connection to the pipe 135 ₁ leading to outside. Here, as shown in FIG. 3 (A), by connecting a pipe 135 ₀ to the pipe 125, as the air from the supply device 130 ₀ shown in FIG. 3 (B) to be supplied to the Bernoulli cup 124 in, by connecting the pipes 135 ₀ to the pipe 135 _1, air is exhausted to the outside the exposure apparatus 100, supply to the Bernoulli chuck 124 is stopped.

The pipe 135 _1, throttle valve 136 is provided. In the case of connecting the pipes 135 ₀ with the electromagnetic valve 134 when the pipe 135 ₁ connected to the pipe 125, so that the air flow pipe 135 in the ₀ does not change, piping for air using a throttle valve 136 135 The conductance of ₁ is adjusted to match the conductance of the pipe 125. Thus, it is possible to air passing through the temperature control unit 133 in a substantially constant state, will be air temperature control pipe 135 ₀ is performed under certain conditions, the air temperature Can be kept unchanged. Incidentally, without matching the conductance of the pipe 135 ₁ and the pipe 125, each conductance may be set to have a predetermined relationship.

May also be configured to circulate the air by returning the air supplied to the pipe 135 ₁ to the supply unit 130 _0.

The air supply unit 130 described above is provided for each air supply system. That is, an independent air supply unit 130 is connected to each of the pipes 125 (125 ₁ , 125 ₂ ) in FIG. Thus, independently of the through pipe 125 ₁ of air to the Bernoulli cup ₁₂₄ 0, 124 ₁ is supplied, air is supplied to the Bernoulli cup 124 ₂ via the pipe 125 _2. As will be described later, by supplying air at different flow rates for each air supply system (spouting from the Bernoulli cup 124), the wafer W is exerted with a non-uniform distribution of suction force (suction force), thereby allowing the wafer to W can be kept flat. The configuration of the air supply system is not limited to the configuration of the present embodiment, and can be arbitrarily configured according to actual deformation of the wafer W, for example.

  A measurement stage MST is disposed in the vicinity of the loading position. The measurement stage MST is driven on the stage base 22 in the X axis direction and the Y axis direction by a measurement stage drive system (not shown) including a linear motor and the like. On the measurement stage MST, a line sensor (not shown) that measures the shape of the wafer W by irradiating the back surface of the wafer W held on the loading disk 121 in a line shape and receiving the reflected light. Is provided. Further, position information of the measurement stage MST in the XY plane is measured by a measurement stage position measurement system (not shown) including an interferometer system. The measurement result is supplied to the main controller 20.

  The loading unit 120 (drive unit 122, air supply unit 130, wafer transfer arm 118, etc.) is controlled by the main controller 20 (see FIG. 4).

  FIG. 4 shows the main configuration of the control system of the exposure apparatus 100. The control system is mainly configured of a main controller 20 including a microcomputer (or workstation) that performs overall control of the entire apparatus.

  Wafer loading using the loading unit 120 will be described.

Prior to loading the wafer, the temperature of the air ejected from the Bernoulli cup 124 is controlled. Here, the air, when ejected from or Bernoulli cup 124 when flowing in the pipe 125, the Joule-Thomson effect, the temperature is lowered by expansion while maintaining a pressure difference between the pipe 135 _0. For example, for a pressure change of 0.1 MPa, the air temperature changes by about 0.2 degrees. In this embodiment, since the air pressure changes in the range of 0.05 MPa, a temperature change of about 0.1 degrees is expected. When the air whose temperature changes by about 0.1 ° is blown onto the wafer W, the wafer W is cooled, and there is a possibility of causing distortion of the pattern due to thermal contraction. Therefore, it is necessary to suppress the temperature change of the air to 0.01 degrees or less.

  FIG. 5 is a flowchart showing a procedure for controlling the temperature of air when the wafer W is held using the loading disk 121.

As a premise, it is assumed that the loading disk 121 is upward (+ Z direction) and the wafer stage WST is retracted other than the loading position. The air is not supplied to the Bernoulli cup 124, assumed to be a pipe 135 ₀ on the condition being flushed empty. Whereas the loading disk 121 is used intermittently with the loading operation of the wafer, the temperature of the air should always be kept constant at all times the air even when stopping the loading disk 121 piping 135 ₀ It is good to leave it in Therefore, a predetermined flow rate by the flow rate control valve 131 (e.g., flow rate 1 liter / minute for no deformation wafer) flowing air in the pipe 135 _0, pipe 135 by the electromagnetic valve 134 when there is no need sucking operation by the Bernoulli cup 124 ₀ by connecting the pipe 135 ₁ allowed to exhaust air.

In step 204, main controller 20 operates loading disk 121. That is, using the solenoid valve 134 supplies air to the plurality of Bernoulli cup 124 to connect the pipes 135 ₀ to the pipe 125. Here, by which to adjust the conductance of the piping 135 ₁ using the throttle valve 136, before and after the connecting piping 135 ₀ to the pipe 125, the flow rate of air flowing through the pipe 135 ₀ is not to change Therefore, the temperature control unit 133 does not need to adjust the control state (temperature control state) before and after the connection. Therefore, since stable air temperature control is performed, fluctuations in the air temperature can be suppressed. Although the flow rate of air flowing through 135 in ₀ before and after the connection is not to change, but is not limited thereto. For example, the flow rates may be set to have a predetermined relationship before and after the front and rear connection. Further, according to the predetermined relationship may be previously adjusted conductance of the pipe 135 ₁ and the pipe 125.

In the next step 206, the main controller 20 controls the temperature of the air. The main controller 20 measures the temperature of the air ejected from the plurality of Bernoulli cups 124 using the temperature sensor 128, and the temperature controller adjusts the temperature of the air to a predetermined temperature (or the temperature of the wafer W). heating the air flowing through the pipes 135 ₀ with 133.

  In the next step 208, the wafer W is sucked and held using the loading unit 120 (loading disk 121).

  At this time, as shown in FIG. 6A, the wafer W provided with the sensitive layer (resist layer) by C / D (not shown) is moved by the wafer transfer arm 118 toward the loading position by a black arrow. It is conveyed in the direction (+ Y direction). When the wafer W is transferred to just below the loading disk 121, the main controller 20 drives the loading disk 121 in the direction of the white arrow (−Z direction) as shown in FIG. The lower surface of the disk 121 is brought close to the surface of the wafer W. Instead of or in addition to driving the loading disk 121, the wafer transfer arm 118 may be driven in the direction opposite to the white arrow (+ Z direction).

  When the lower surface of the loading disk 121 approaches the surface of the wafer W to the order of 100 μm, the suction force (suction force) of the loading disk 121 reaches the wafer W, and the wafer W is sucked and held by the loading disk 121 without contact. Thereby, the movement of the wafer W in the Z-axis direction, the θx direction, and the θy direction is restricted. As shown in FIG. 6C, the main controller 20 finely drives the loading disk 121 holding the wafer W in the direction of the white arrow (+ Z direction), or instead of (or with this). The wafer transfer arm 118 is finely driven in the direction opposite to the white arrow (−Z direction), and the wafer transfer arm 118 that has released the wafer W is retracted in the direction of the black arrow (−Y direction).

  If the air temperature control in step 206 is sufficiently faster than the temperature change of the wafer W, the order of steps 206 and 208 may be reversed.

  In the next step 210, main controller 20 measures the shape of wafer W held on loading disk 121 by using the plurality of gap sensors (not shown) described above. Here, a line sensor (not shown) provided on the measurement stage MST may be used instead of the gap sensor.

In the next step 212, the main controller 20 determines the flow rate of air ejected from each of the plurality of Bernoulli cups 124 (124 ₀ , 124 ₁ , 124 ₂ ) based on the shape of the wafer W, and the flow control valve 131. Use to adjust the air flow rate. As a result of the measurement in step 210, for example, it is assumed that the wafer W is bent upward in a convex shape. A case, the main controller 20, with a flow rate control valve 131, to increase the air flow rate with respect to the Bernoulli cup ₁₂₄ 0, 124 ₁ are ejected from the Bernoulli cup 124 _2. Thereby, a strong suction force acts on the peripheral portion with respect to the central portion of the wafer W. On the other hand, as a result of the measurement in step 210, it is assumed that the wafer W is bent in a convex shape downward. A case, the main controller 20, with a flow rate control valve 131, to reduce the air flux with respect to the Bernoulli cup ₁₂₄ 0 124 ₁ is ejected from the Bernoulli cup 124 _2. Thereby, a weak suction force acts on the peripheral portion with respect to the central portion of the wafer W. As a result, the wafer W is held flat by the loading disk 121.

  Next, wafer W sucked and held by loading disk 121 is loaded onto wafer stage WST.

  The main controller 20 images the periphery (notch or the like) of the wafer W held on the loading disk 121 by using the three image sensors 129. Main controller 20 obtains the positional deviation and rotation (θz rotation) error of wafer W in the X-axis direction and Y-axis direction from these imaging results.

  As shown in FIG. 7A, main controller 20 moves wafer stage WST to the loading position. Here, main controller 20 positions wafer stage WST at a position and orientation that cancels the positional deviation and rotation error obtained above. Alternatively, the positional deviation and the rotation error obtained above may be stored, and the result may be corrected in the alignment measurement.

  When wafer stage WST is positioned immediately below loading disk 121, main controller 20 causes three CT pins 140 from inside wafer stage WST via a wafer holder (not shown) as shown in FIG. 7B. Are exposed in the direction of the black arrow (+ Z direction), and their tips are brought into contact with the back surface of the wafer W held on the loading disk 121 to support (suck) the wafer W. This further restricts the movement of the wafer W in the X-axis direction, the Y-axis direction, and the θz direction.

  The wafer W is held on the loading disk 121 so that movement in the Z-axis direction, θx direction, and θy direction is restricted, and the back surface is supported by three CT pins 140, so that the X-axis direction, Y When the movement in the axial direction and the θz direction is restricted, as shown in FIG. 7C, the main controller 20 drives the loading disk 121 in the direction of the white arrow (−Z direction), At the same time, the three CT pins 140 are moved in the direction of the black arrow (−Z direction) to enter the wafer stage WST. As a result, as shown in FIG. 8A, wafer W is loaded on wafer stage WST while maintaining a state where movement in the direction of six degrees of freedom is restricted.

When wafer W is loaded onto wafer stage WST, main controller 20 operates a wafer holder (not shown) to attract and hold wafer W on wafer stage WST, and hold wafer W by loading disk 121. To release. That is connected pipes 135 ₀ by the electromagnetic valve 134 in the piping 135 ₁ air is exhausted.

  Finally, as shown in FIG. 8B, main controller 20 retracts loading disk 121 in the direction of the white arrow (+ Z direction), so that wafer W is loaded onto wafer stage WST. Complete.

  The unloading of wafer W on wafer stage WST is performed in the reverse procedure of loading. Therefore, detailed description thereof is omitted.

  An exposure operation of the exposure apparatus 100 of this embodiment will be briefly described.

  Prior to exposure, main controller 20 loads wafer W on which a sensitive layer (resist layer) is provided by C / D (not shown) onto wafer stage WST (wafer holder (not shown)) according to the above-described procedure. To do.

  Main controller 20 detects an alignment mark (attached to a sample shot area on wafer W) provided on the surface of wafer W using alignment detection system AS, and performs alignment measurement (EGA). Thereby, the position of the shot area on the wafer W in the XY plane (further, the magnification in the scanning direction, the rotation around the optical axis AX, and the orthogonality) is determined. Details of alignment measurement (EGA) are described in, for example, Japanese Patent Laid-Open No. 6-349705.

  Main controller 20 calculates the relative positional relationship between the projection position of the pattern on reticle R (projection center of projection optical system PL) and each shot area on wafer W according to the result of alignment measurement (EGA). In accordance with the result, main controller 20 sequentially exposes the pattern of reticle R in the entire shot area on wafer W by scanning exposure.

  In the scanning exposure for each shot area on wafer W, main controller 20 monitors the measurement results of reticle interferometer 14 and interferometer system 18, and moves reticle stage RST and wafer stage WST to their respective scan start positions (acceleration). Move to the start position. Then, main controller 20 relatively drives both stages RST and WST in the Y-axis direction, but in opposite directions. Here, when both stages RST and WST reach their respective target speeds, the pattern area of reticle R starts to be illuminated by illumination light IL, and scanning exposure is started.

  Main controller 20 performs a reticle stage so as to maintain the speed Vr of reticle stage RST and the speed Vw of wafer stage WST in the Y-axis direction at a speed ratio corresponding to the projection magnification of projection optical system PL during scanning exposure. The RST and the wafer stage WST are driven synchronously.

  As reticle R moves in the Y-axis direction, the entire pattern area is illuminated by illumination light IL. At the same time, the pattern of the reticle R is transferred onto the wafer W by moving the wafer W in the Y-axis direction, but in the opposite direction to the reticle R. Thereby, the scanning exposure for one of the shot areas on the wafer W is completed.

  When the scanning exposure for one of the shot areas is completed, main controller 20 moves (steps) wafer stage WST to the scanning start position (acceleration start position) for the next shot area. Then, main controller 20 performs scanning exposure on the next shot area in the same manner as described above. The scanning exposure for the other shot areas is performed in the same manner. In this manner, the pattern of the reticle R is transferred to all the shot areas on the wafer W by repeating the step movement between the shot areas and the scanning exposure for each shot area.

  When the exposure is completed, main controller 20 unloads exposed wafer W from wafer stage WST (wafer holder (not shown)) by a procedure reverse to the above-described procedure. Then, the next wafer W provided with a sensitive layer (resist layer) by C / D (not shown) is loaded onto wafer stage WST (wafer holder (not shown)) by the above-described procedure. That is, the wafer W on the wafer stage WST is exchanged. Main controller 20 repeats the exposure operation for a new wafer W in the same manner.

As described above in detail, according to the exposure apparatus 100 of the present embodiment, the temperature of the air ejected from the loading disk 121 (Bernoulli cup 124) is measured using the temperature sensor 128, and temperature control is performed according to the measurement result. temperature of the air in the pipe 135 within ₀ is adjusted by controlling the vessel 133. As a result, the wafer can be held using the loading unit 120 (loading disk 121) without changing the temperature. Further, by using the loading unit 120 (loading disk 121) of the present embodiment, the wafer W can be loaded on the wafer stage WST without being thermally deformed.

Although the temperature sensor 128 in this embodiment is provided in the bottom portion of the disk body 123, instead of this, for example, as shown in FIG. 9 (A), a flow path 135 ₀ after the passage of the temperature controller 133 It may be arranged so that the temperature of the gas in the flow path becomes a predetermined value. Further, as shown in FIG. 9B, it may be arranged in the flow path 125 in front of the Bernoulli cup 124. You may arrange | position in several places of the flow path of gas. In this case, the measurement point (sensor using the measurement result) may be switched as appropriate.

  Further, a sensor other than the temperature sensor 128 may be used if information on the gas temperature is obtained. For example, information on the temperature of the gas may be obtained by measuring the pressure of the gas.

  In the exposure apparatus 100 of the present embodiment, the loading position for loading the wafer W onto the wafer stage WST and the unloading position for unloading the wafer W from the wafer stage WST are arranged at the same position. Instead, they may be arranged at different positions, and a loading unit (unloading unit) 120 may be provided for each. As a result, the throughput of the wafer W can be expected to be improved because the wafer W can be loaded and unloaded in parallel with other operations.

  In the above-described embodiment, the case where the present invention is applied to a dry type exposure apparatus that exposes the wafer W without using liquid (water) has been described. No. 99/49504, European Patent Application No. 1,420,298, International Publication No. 2004/055803, US Pat. No. 6,952,253, etc. The present invention can also be applied to an exposure apparatus that forms an immersion space including an optical path of illumination light between the wafer and the wafer, and exposes the wafer with illumination light through the projection optical system and the liquid in the immersion space. . The present invention can also be applied to an immersion exposure apparatus disclosed in, for example, US Patent Application Publication No. 2008/0088843.

  In the above embodiment, the case where the present invention is applied to a scanning exposure apparatus such as a step-and-scan method has been described. However, the present invention is not limited to this, and the present invention is applied to a stationary exposure apparatus such as a stepper. May be. 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. Further, as disclosed in, for example, US Pat. No. 6,590,634, US Pat. No. 5,969,441, US Pat. No. 6,208,407, etc. The present invention can also be applied to a multi-stage type exposure apparatus provided with a stage. Further, as disclosed in, for example, US Pat. No. 7,589,822, an exposure including a measurement stage including a measurement member (for example, a reference mark and / or a sensor) separately from the wafer stage. The present invention can also be applied to an apparatus.

  Further, the projection optical system in the exposure apparatus of the above embodiment may be not only a reduction system but also any of the same magnification and enlargement systems, and the projection optical system PL may be any of a reflection system and a catadioptric system as well as a refraction 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, U.S. 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 as vacuum ultraviolet light, For example, a harmonic which 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 can be applied to 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). 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.

  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 1 on the wafer by one scan exposure. The present invention can also be applied to an exposure apparatus that double exposes two shot areas almost simultaneously.

  In the above embodiment, the object on which the pattern is to be formed (the object to be exposed to which the energy beam is irradiated) is not limited to the wafer, but may be another object such as a glass plate, a ceramic substrate, a film member, or a mask blank. good.

  The use of the exposure apparatus is not limited to the exposure apparatus for semiconductor manufacturing, but for example, an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern to a square glass plate, an organic EL, a thin film magnetic head, an image sensor (CCD, 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. And a lithography step for transferring the mask (reticle) pattern to the wafer by the exposure method, a development step for developing the exposed wafer, and an etching step for removing the exposed member other than the portion where the resist remains by etching, It is manufactured through a resist removal step for removing a resist that has become unnecessary after etching, a device assembly step (including a dicing process, a bonding process, and a packaging 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.

DESCRIPTION OF SYMBOLS 20 ... Main control apparatus, 100 ... Exposure apparatus, 118 ... Wafer transfer arm, 120 ... Loading unit, 121 ... Loading disk, 124 (124 ₀ , 124 ₁ , 124 ₂ ) ... Bernoulli cup, 125 (125 ₁ , 125 ₂ , 135 ₀ , 135 ₁ ) ... Piping, 128 ... Temperature sensor, 129 ... Image sensor, 130 ... Air supply unit, 130 ₀ ... Supply device, 131 ... Flow control valve, 132 ... Flow meter, 133 ... Temperature controller, 134 ... Solenoid valve, 136 ... throttle valve, 140 ... CT pin, PL ... projection optical system, PU ... projection unit, W ... wafer, WST ... wafer stage.

Claims (17)

A suction device that applies a suction force to a plate-like object in a non-contact manner,
An opposing portion that faces the object and an ejection portion that ejects a gas, and the suction force is generated by forming a gas flow between the opposing portion and the object by the gas ejected from the ejection portion. A suction member that can be generated;
A temperature control device capable of adjusting the temperature of the gas and supplying the adjusted gas to the ejection unit;
A setting device for setting at least one of the flow rate and the flow velocity of the gas ejected from the ejection part to a predetermined value;
A change device that is provided on the gas supply path from the temperature control device to the ejection unit and changes at least one of the flow rate and the flow rate of the gas guided from the temperature control device according to the predetermined value;
A suction device.   The setting device sets at least one of a gas flow rate and a flow velocity to a first set value when the suction member generates the suction force, and a gas flow rate when the suction member does not generate the suction force. And at least one of the flow velocity and the flow velocity is set to a second set value.   In the change device, when the setting device sets the second set value, at least one of a flow rate and a flow velocity of the gas ejected from the ejection unit is less than the gas introduced from the temperature control device. The suction device according to claim 2, which is changed to become.   The suction device according to claim 3, wherein when the setting device sets the second set value, the changing device stops the supply of the gas guided from the temperature control device to the ejection unit.   The suction device according to any one of claims 1 to 4, wherein the changing device includes a valve, and the valve guides the gas guided from the temperature control device without passing through the ejection portion. An exhaust part for exhaust, and an exhaust passage connecting the exhaust part and the valve;
The suction device according to claim 5, wherein a resistance received by the gas passing through the exhaust passage and a resistance received by the gas passing from the valve to the ejection portion are set in a predetermined relationship.   The suction device according to claim 6, further comprising a throttle provided in the exhaust passage and configured to adjust a resistance received by a gas passing through the exhaust passage.   The suction device according to any one of claims 1 to 7, wherein the changing device changes a flow rate of the gas guided from the temperature device. A flowmeter for measuring a flow rate of at least one of a gas supplied to the temperature control device and a gas guided from the temperature control device to the ejection unit;
The suction device according to claim 8, further comprising: a supply device that adjusts a flow rate of a gas supplied to the temperature control device using a measurement result of the flow meter.   The suction device according to any one of claims 1 to 9, wherein the temperature control device includes a sensor that obtains information related to a gas temperature, and adjusts the temperature of the gas using information obtained by the sensor.   The suction device according to claim 10, wherein the temperature sensor obtains the information regarding a gas flowing through a path from the temperature control device to the change device.   The suction device according to claim 10, wherein the temperature sensor obtains the information regarding a gas flowing in a path from the change device to the ejection unit.   The suction device according to claim 10, wherein the temperature sensor obtains the information regarding the gas ejected from the ejection part.   The suction device according to claim 13, wherein the temperature sensor is disposed in the vicinity of a gas ejection hole provided on the facing portion of the suction member. The opposed portion of the suction member is provided with a plurality of ejection holes for ejecting gas,
Further comprising a shape sensor for measuring the shape of the object;
The suction device according to any one of claims 1 to 14, wherein a flow rate of gas sent to each of the plurality of ejection holes is determined using a measurement result of the shape sensor. An exposure apparatus that irradiates an energy beam to form a pattern on an object,
A moving body that moves by sucking an object;
A suction device according to any one of claims 1 to 15,
An exposure apparatus that stacks the object on the moving body using the suction device. A suction method that applies a suction force to a plate-like object in a non-contact manner,
Generating the suction force by forming a gas flow between the object and the facing part facing the object by the gas ejected from the ejection part for ejecting the gas;
Adjusting the temperature of the gas and supplying the adjusted gas to the ejection part;
Setting at least one of the flow rate and the flow velocity of the gas ejected from the ejection part to a predetermined value;
A suction method comprising: changing at least one of a flow rate and a flow rate of the gas according to the predetermined value on a path through which the temperature-controlled gas is supplied to the ejection unit.

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