Source: https://patents.google.com/patent/KR101181683B1/en
Timestamp: 2019-12-11 12:22:10
Document Index: 120160197

Matched Legal Cases: ['art 124', 'art 170', 'art 172', 'art 172', 'art 170', 'art 172', 'art 172', 'art 170', 'art 170', 'art 170', 'art 170', 'art 170', 'art 170', 'art 170', 'art 170', 'art 170', 'art 170', 'art 170', 'art 124', 'art 27', 'art 27', 'arts 25', 'art 25', 'art 27', 'art 27', 'art 26', 'art 25', 'art 27', 'art 27', 'art 25', 'art 25', 'art 26', 'art 25', 'arts 26', 'art 25', 'arts 25']

KR101181683B1 - Exposure equipment, exposure method and device manufacturing method - Google Patents
KR101181683B1
KR101181683B1 KR20067022068A KR20067022068A KR101181683B1 KR 101181683 B1 KR101181683 B1 KR 101181683B1 KR 20067022068 A KR20067022068 A KR 20067022068A KR 20067022068 A KR20067022068 A KR 20067022068A KR 101181683 B1 KR101181683 B1 KR 101181683B1
KR20067022068A
KR20070019721A (en
2004-03-25 Priority to JPJP-P-2004-00088282 priority
2005-03-25 Application filed by 가부시키가이샤 니콘 filed Critical 가부시키가이샤 니콘
2007-02-15 Publication of KR20070019721A publication Critical patent/KR20070019721A/en
2012-09-19 Publication of KR101181683B1 publication Critical patent/KR101181683B1/en
At least a part including the plate is replaceable in the measurement stage MST which has a plate 101 to which a liquid is supplied and performs measurement on exposure through the projection optical system PL and the liquid Lq. For this reason, before a plate surface deteriorates by contact with a liquid, the measurement regarding exposure can always be performed with high precision by exchanging at least one part containing the plate, and it becomes possible to maintain high precision exposure further. . In addition, when at least one end surface of the plate is mirror-finished, even when at least a part of the measurement unit including the plate is replaced with a new one, even if the part after the replacement is roughly positioned, through the mirror-processed end surface of the plate, For example, the position of the plate can be accurately measured using an interferometer or the like.
Exposure apparatus, immersion, lithography, projection optics, measurement
BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an exposure apparatus, an exposure method, and a device manufacturing method, and more particularly, to an exposure apparatus and an exposure method used in a lithography process when manufacturing electronic devices such as semiconductor elements (integrated circuits) and liquid crystal display elements. And a device manufacturing method using the exposure apparatus.
Background Art In the lithography process for manufacturing electronic devices such as semiconductor elements (integrated circuits) and liquid crystal display elements, a wafer or glass plate coated with a resist (photosensitive agent) on a pattern image of a mask (or reticle) through a projection optical system, etc. A step-and-repeat reduction projection exposure apparatus (so-called stepper) that is transferred to each of a plurality of shot regions on a photosensitive object (hereinafter referred to as a "wafer"), or a projection exposure apparatus (so-called scanning stepper (scanner) of a step-and-scan method) Also called)) is mainly used.
In this type of projection exposure apparatus, higher resolution (resolution) is required every year with the miniaturization of patterns due to the higher integration of integrated circuits, and therefore, shorter wavelengths of exposure light and an increase in numerical aperture (NA) of the projection optical system. (Large NAization) has been gradually progressing. By the way, shortening the exposure light and increasing the NA of the projection optical system improve the resolution of the projection exposure apparatus while causing narrowing of the depth of focus. In addition, it is assured that the exposure wavelength will be shorter in the future, and the depth of focus becomes too narrow in this way, and there is a fear that the focus margin during the exposure operation is insufficient.
Therefore, an exposure apparatus using the liquid immersion method has recently attracted attention as a method of substantially shortening the exposure wavelength and increasing (widely) the depth of focus compared to the air. As an exposure apparatus using this immersion method, it is known to expose between the lower surface of a projection optical system and the wafer surface in the state locally filled with liquid, such as water or an organic solvent (for example, following patent document 1). Reference). In the exposure apparatus described in Patent Document 1, the wavelength of the exposure light in the liquid is increased by 1 / n times in the air (n is usually about 1.2 to 1.6 by the refractive index of the liquid), and the resolution is improved. To increase the depth of focus by n times compared to the projection optical system (assuming that such a projection optical system can be manufactured) obtainable without following the immersion method, that is, to substantially increase the depth of focus by n times compared to air. Can be.
Moreover, in recent years, the exposure apparatus provided with the stage (measurement stage) which can drive in a two-dimensional plane independently from a wafer stage (substrate stage), and the measuring instrument used for measurement is provided (for example, a patent See Documents 2, 3, etc.). In the case of employing this measurement stage, only the minimum necessary structural members (for example, a wafer holder, etc.) necessary for the exposure of the wafer need be formed in the wafer stage, so that the size and weight of the wafer stage can be reduced. As a result, it is expected that the driving mechanism (motor) for driving the wafer stage can be reduced in size and the amount of heat generated from the motor can be reduced, so that thermal deformation of the wafer stage and deterioration in exposure accuracy can be suppressed to the maximum.
By the way, in the case of employing the measurement stage in the above-described liquid immersion exposure apparatus, various measurements related to the exposure are made in the state of filling the water on the measurement stage, so that the surface of the member in contact with the liquid of the measurement stage is in contact with the liquid and It is deteriorated by irradiation of exposure light, the measurement precision of various measurement related to exposure deteriorates with time, and also it is high in probability that it will become difficult to maintain exposure precision for a long term. Of course, the water repellent coating is applied to the upper surface of each measuring instrument part of the measurement stage, but this water repellent coating is generally weak against exposure light (ultraviolet or vacuum ultraviolet light) used in immersion exposure, It is deteriorated by nature.
In addition, even when various measuring instruments are provided on the wafer stage without employing the measuring stage, the surface of the member in contact with the liquid (water repellent coating is often applied to the surface of the member) is used for contact with the liquid and irradiation of exposure light. And the phenomenon that the measurement accuracy of various measurement related to the exposure deteriorates with time may occur as described above.
Patent Document 2: Japanese Patent Application Laid-Open No. 11-135400
Patent document 3: Unexamined-Japanese-Patent No. 3-211812
The present invention has been made under the above-described circumstances, and in view of the first aspect, the present invention provides an exposure apparatus for exposing a substrate through a projection optical system, comprising: a substrate stage on which the substrate is mounted and movable; It is a 1st exposure apparatus characterized by including the measurement part which measures the said exposure via the projection optical system and the said liquid, and at least one part containing the said plate which comprises the said measurement part is comprised so that replacement is possible.
According to this, at least one part containing a plate is replaceable among the measuring parts which have a plate to which a liquid is supplied, and measure the said exposure via a projection optical system and a liquid. For this reason, before the plate surface deteriorates due to contact with the liquid, by exchanging at least a part of the plate including the plate, the measurement on the exposure can always be performed with high accuracy, and furthermore, it is possible to maintain a high precision exposure. Become.
According to a second aspect of the present invention, there is provided an exposure apparatus for exposing a substrate through a projection optical system, comprising: a substrate stage movable with the substrate mounted thereon; and a plate on which at least one end surface is mirror-processed; It is a 2nd exposure apparatus provided with the measurement part which measures the exposure regarding, and at least one part containing the said plate which comprises the said measurement part is comprised so that replacement is possible.
According to this, since at least one part containing the plate which comprises a measurement part becomes replaceable, exposure is carried out by exchanging at least one part containing the plate before this plate surface deteriorates by irradiation of exposure light etc. at the time of a measurement. The measurement concerning can always be performed with high precision, and it becomes possible to maintain high precision exposure further. In addition, since at least one end surface of the plate is mirror-finished, even when at least a part of the measurement unit including the plate is replaced with a new one, even if the component after the replacement is roughly positioned, the plate is mirror-processed. Through the cross section, for example, the position of the plate can be accurately measured using an interferometer or the like. Therefore, even if a part of the measurement part is roughly positioned at the time of exchange, it becomes possible to accurately position the measurement part at a desired position at the time of measurement, so that it is not necessary to take a long time for the exchange, and to increase the stop time accompanying the exchange. It is possible to effectively prevent the deterioration of device operation efficiency due to this.
According to the third aspect of the present invention, there is provided an exposure apparatus for exposing a substrate through a projection optical system, the exposure apparatus having a substrate stage movable by mounting the substrate and a replaceable plate, and measuring the exposure through the projection optical system. It is a 3rd exposure apparatus characterized by including a measurement part and the detection apparatus which detects the replacement time of the said plate.
According to this, when the measurement time of the measurement part immediately before it begins to fall by experiment is calculated | required beforehand, this time is set as the replacement time of the plate which a detection apparatus detects beforehand, and when a detection apparatus detects the replacement time. By replacing the plate, it becomes possible to replace the plate at the optimum time before the measurement accuracy of the measurement unit is lowered. That is, while the measurement accuracy of the measurement regarding the exposure by the measurement unit can be maintained with high accuracy, the exchange frequency of the plate can be suppressed as much as possible. Therefore, the exposure accuracy can be maintained with high precision over a long period of time, and it is possible to effectively prevent the decrease in device operation efficiency due to the increase in the stop time accompanying the exchange of the plate.
According to a fourth aspect of the present invention, there is provided an exposure method for exposing a substrate, comprising: a step of exchanging at least a portion of the measurement unit that measures the exposure through a plate to which a liquid is supplied; It is the 1st exposure method including the process of measuring the said exposure using the said measurement part after replacement, and exposing the said board | substrate by reflecting the measurement result.
According to this, for example, before the plate surface deteriorates by contact with a liquid, by replacing at least a part of the measuring unit including the plate, the measurement unit that measures the exposure through the plate to which the liquid is supplied, A measurement part can perform measurement regarding exposure with high precision, and high precision exposure is attained by reflecting the measurement result.
This invention is an exposure method which exposes a board | substrate from a 5th viewpoint, Comprising: At least one part of the measuring part which measures the said exposure through the plate in which at least 1 cross section was mirror-processed is replaced, including the said plate. It is a 2nd exposure method including the process of measuring the position of the said plate after the said replacement through the said cross section, performing the said measurement using the said measurement part, and reflecting the said measurement result, and exposing the said board | substrate. .
According to this, for example, before a plate surface deteriorates by irradiation of exposure light etc. at the time of a measurement, at least one part containing the plate is replaced, the position of the said plate is measured through the said cross section, and it exposes using the said measurement part. The measurement on the exposure can be performed with high accuracy, and when replacing at least a part of the measurement unit including the plate with a new one, even if the parts after the replacement are roughly positioned, the mirror surface of the plate The machined section allows accurate positioning of the plate. Therefore, even if a part of the measurement part is roughly positioned at the time of exchange, the measurement part can be accurately positioned at a desired position at the time of measurement. In addition, highly accurate exposure is possible by reflecting the measurement result.
According to a sixth aspect of the present invention, there is provided an exposure method for exposing a substrate, wherein the measurement is performed using a measurement unit that performs measurement related to the exposure through a plate, and the replacement time of the plate is detected. It is a 3rd exposure method including the process of exchanging a plate, and exposing the said board | substrate by reflecting the said measurement result.
According to this, the time just before the fall of the measurement accuracy of a measurement part is calculated | required by experiment etc., and this time is set previously as a replacement time of a plate. By replacing the plates when the replacement timing is detected, the plates can be replaced at the optimum time before the measurement accuracy of the measurement unit is lowered. That is, while the measurement accuracy of the measurement regarding the exposure by the measurement unit can be maintained with high accuracy, the exchange frequency of the plate can be suppressed as much as possible. Moreover, high precision exposure is attained by reflecting the said measurement result.
Moreover, in a lithography process, it is possible to improve the productivity of a high integration microdevice by exposing a board | substrate using the 1st-3rd exposure apparatus of this invention and forming a device pattern on the board | substrate. Therefore, from another viewpoint, this invention can also be called the device manufacturing method using any one of the 1st-3rd exposure apparatus of this invention.
1 is a schematic view showing an exposure apparatus according to a first embodiment.
2 is a perspective view showing a stage device.
3A is a perspective view illustrating the measurement stage.
3B is a perspective view illustrating a state where the measurement table is removed from the measurement stage.
4 is a longitudinal cross-sectional view of the measurement stage.
5 is a longitudinal cross-sectional view of a self-weight canceller.
6 is a schematic diagram for explaining the operation of the self-weight canceller.
7 is a block diagram showing a main configuration of a control system of the exposure apparatus of the first embodiment.
FIG. 8A is a (first) plan view for explaining the parallel processing operation of the first embodiment. FIG.
FIG. 8B is a (second) plan view for explaining the parallel processing operation of the first embodiment. FIG.
9 (a) is a (third) plan view for explaining the parallel processing operation of the first embodiment.
9 (b) is a (fourth) plan view for explaining the parallel processing operation of the first embodiment.
FIG. 10 is a (fifth) plan view for explaining the parallel processing operation of the first embodiment. FIG.
It is a perspective view which shows the measurement stage and carrying in / out mechanism which concerns on 2nd Embodiment.
12 is a perspective view illustrating a state in which a plate is taken out from a measurement stage.
EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of this invention is described based on FIG.
The schematic structure of the exposure apparatus 100 of 1st Embodiment is shown by FIG. This exposure apparatus 100 is a step-and-scan projection exposure apparatus, that is, a so-called scanning stepper (also called a scanner). The exposure apparatus 100 includes a lighting stage 10, a reticle stage RST holding a reticle R as a mask, a projection unit PU, a wafer stage WST as a substrate stage, and a measurement stage constituting a measurement unit ( The stage apparatus 50 which has MST, these control systems, etc. are provided. On the wafer stage WST, the wafer W as a substrate is mounted.
The illumination system 10 illuminates the slit-shaped illumination region on the reticle R defined by the reticle blind (not shown) with illumination light (exposure light IL) at approximately uniform illuminance. As the illumination light IL, ArF excimer laser light (wavelength 193 nm) is used as an example.
On the said reticle stage RST, the reticle R in which a circuit pattern etc. were formed in the pattern surface (lower surface in FIG. 1) is fixed by vacuum suction, for example. The reticle stage RST is, for example, an optical axis of the illumination system 10 (projection optical system to be described later) by a reticle stage driver 11 (not shown in FIG. 1, see FIG. 7) including a linear motor or the like. It can be micro-driven in the XY plane perpendicular to the optical axis AX of PL) and specified in a predetermined scanning direction (here, the Y-axis direction in the horizontal direction in the plane in FIG. 1). It can be driven by the scanning speed.
The position (including rotation around the Z axis) in the stage moving surface of the reticle stage RST is referred to as a reticle laser interferometer (hereinafter referred to as a "reticle interferometer"): 116 and a moving mirror 15 (actually, the Y axis). A Y moving mirror having a reflective surface orthogonal to the direction and an X moving mirror having a reflective surface orthogonal to the X axis direction are provided), for example, at a resolution of about 0.5 to 1 nm. The measured value of this reticle interferometer 116 is sent to the main control apparatus 20 (not shown in FIG. 1, see FIG. 7), and in the main control apparatus 20 based on the measured value of this reticle interferometer 116 The reticle stage RST is calculated by calculating the positions of the X-axis direction, the Y-axis direction, and the θz direction (the rotation direction around the Z-axis) of the RST, and controlling the reticle stage drive unit 11 based on the calculation result. Control the position (and speed) of.
Above the reticle R, a pair of reticle alignment marks on the reticle R and a pair of reference marks on the measurement stage MST corresponding to them via the projection optical system PL (hereinafter referred to as "first reference mark"). The pair of reticle alignment detection systems RAa and RAb which consist of TTR (Through The Reticle) alignment system which used the light of the exposure wavelength for observing simultaneously) is provided in the X-axis direction at predetermined distances. As these reticle alignment detection systems RAa and RAb, what has the structure similar to what was disclosed, for example in Unexamined-Japanese-Patent No. 7-176468 and US Pat. No. 5,646,413 etc. is used. To the extent permitted by national legislation of the designated country (or selected selected country) specified in this international application, this publication and the disclosures of the corresponding US patents are incorporated herein by reference.
The projection unit PU is disposed below the reticle stage RST in FIG. 1. The projection unit PU is comprised including the barrel 40 and the projection optical system PL which consists of the some optical element hold | maintained in predetermined position relationship in the barrel 40. As shown in FIG. As the projection optical system PL, for example, a refractive optical system composed of a plurality of lenses (lens elements) having a common optical axis AX in the Z axis direction is used. This projection optical system PL is, for example, both telecentric and has a predetermined projection magnification (for example, 1/4 or 1/5 times). For this reason, when the illumination region of the reticle R is illuminated by the illumination light IL from the illumination system 10, the projection optical system PL (projection unit () is provided by the illumination light IL passing through the reticle R. PU)), a reduced image (reduced image of a part of the circuit pattern) of the circuit pattern of the reticle R in the illumination region is formed on the wafer on which a resist (photosensitive agent) is applied to the surface.
In addition, although illustration is abbreviate | omitted, the some specific lens among the some lens which comprises the projection optical system PL is based on the imaging characteristic correction controller 381 (refer FIG. 7) based on the instruction | command from the main control apparatus 20. Moreover, in FIG. The optical properties (including imaging characteristics) of the projection optical system PL can be adjusted, for example, magnification, distortion, coma aberration, image plane curvature (including image plane tilt), and the like. .
In addition, in the exposure apparatus 100 of this embodiment, since exposure which applied the immersion method is performed as mentioned later, the opening on the reticle side becomes large with the numerical aperture NA increasing substantially. For this reason, in the refractive optical system which consists only of a lens, it becomes difficult to satisfy Petzval condition, and it exists in the tendency for a projection optical system to enlarge. In order to avoid the enlargement of the projection optical system, a reflective refractometer (catadioptric system) including a mirror and a lens may be used.
Moreover, since the exposure apparatus 100 of this embodiment performs exposure which applied the immersion method, the lens as an optical element closest to the image surface side (wafer W side) which comprises the projection optical system PL (hereinafter, " A front end lens ”is provided in the vicinity of 91. A liquid supply nozzle 51A and a liquid recovery nozzle 51B constituting the liquid immersion apparatus 132 are formed.
The other end of a supply pipe (not shown), one end of which is connected to the liquid supply device 288 (not shown in FIG. 1, see FIG. 7), is connected to the liquid supply nozzle 51A. ) Is connected to the other end of a recovery pipe (not shown), one end of which is connected to a liquid recovery device 292 (not shown in FIG. 1, see FIG. 7).
The liquid supply device 288 includes a liquid tank, a pressure pump, a temperature control device, a valve for controlling supply and stop of the liquid to the supply pipe, and the like. As the valve, for example, it is preferable to use a flow control valve so that not only the supply / stop of the liquid but also the flow rate can be adjusted. The said temperature control apparatus adjusts the temperature of the liquid in a liquid tank to the temperature of the same grade as the temperature in the chamber (not shown) in which the exposure apparatus main body is accommodated.
The liquid recovery device 292 is configured to include a liquid tank, a suction pump, and a valve for controlling recovery and stop of the liquid through the recovery pipe. As a valve, it is preferable to use a flow control valve corresponding to the valve | bulb of the liquid supply apparatus 288 mentioned above.
As the liquid, ultrapure water (hereinafter, simply described as “water”) through which ArF excimer laser light (light having a wavelength of 193 nm) is transmitted will be used. Ultrapure water can be easily obtained in large quantities at semiconductor manufacturing plants and the like, and has the advantage that there is no adverse effect on photoresist, optical lens or the like on a wafer.
The refractive index n of water with respect to the ArF excimer laser light is approximately 1.44. In this water, the wavelength of the illumination light IL is shortened to 193 nm x 1 / n = about 134 nm.
The liquid supply device 288 and the liquid recovery device 292 are each provided with controllers, and each controller is controlled by the main controller 20 (see FIG. 7). The controller of the liquid supply device 288 opens the valve connected to the supply pipe at a predetermined opening degree according to the instruction from the main control device 20, and between the tip lens 91 and the wafer W via the liquid supply nozzle 51A. Supply water. At this time, the controller of the liquid recovery device 292 opens the valve connected to the recovery pipe at a predetermined opening degree according to the instruction from the main control device 20, and the front end lens 91 through the liquid recovery nozzle 51B. And water are recovered from the wafer W to the inside of the liquid recovery device 292 (liquid tank). At this time, the main controller 20 uses the liquid such that the amount of water supplied from the liquid supply nozzle 51A between the tip lens 91 and the wafer W and the amount of water recovered through the liquid recovery nozzle 51B are always the same. Commands are given to the controller of the supply device 288 and the controller of the liquid recovery device 292. Thus, a certain amount of water Lq (see FIG. 1) is maintained between the front end lens 91 and the wafer W. FIG. In this case, the water Lq held between the front end lens 91 and the wafer W is always replaced.
As can be seen from the above description, the liquid immersion apparatus 132 of the present embodiment includes the liquid supply apparatus 288, the liquid recovery apparatus 292, the supply pipe, the recovery tube, the liquid supply nozzle 51A, and the liquid recovery nozzle 51B. And a local liquid immersion apparatus.
In addition, even when the measurement stage MST is located under the projection unit PU, it is possible to fill water between the measurement table MTB and the front-end lens 91 similarly to the above.
In addition, in the said description, in order to simplify the description, it is assumed that one liquid supply nozzle and one liquid recovery nozzle are provided, respectively, but are not limited to this, and are disclosed in, for example, the pamphlet of International Publication No. 99/49504. As described above, a configuration having many nozzles may be adopted. In other words, as long as the liquid can be supplied between the lowermost optical member (tip lens) 91 and the wafer W constituting the projection optical system PL, the configuration may be any configuration.
Although not shown, an optical fiber type leakage sensor is provided outside the liquid immersion region where water Lq is held, for example, outside the liquid supply nozzle 51A and the liquid recovery nozzle 51B. The main controller 20 is configured to be capable of detecting leaks instantaneously based on the output of the leak sensor.
The stage apparatus 50 includes a frame caster FC, a base panel 12 formed on the frame caster FC, a wafer stage WST disposed above the upper surface of the base panel 12 and a measurement stage ( MST), an interferometer system 118 (see FIG. 7) as a position measuring device including interferometers 16 and 18 for measuring the positions of these stages WST and MST, and a stage for driving the stages WST and MST. The drive part 124 (refer FIG. 7) is provided.
As can be seen from FIG. 2 showing the stage apparatus 50 in a perspective view, the frame caster FC has a convex portion protruding upward with the Y-axis direction in the longitudinal direction near one end of the X-direction and the other side thereof. FCa and FCb are formed in a substantially flat plate-like member.
The base plate 12 is made of a plate-shaped member, also called a platen, and is disposed on a region sandwiched between the convex portions FCa and FCb of the frame caster FC. The upper surface of the base board 12 has a very high flatness, and serves as a guide surface during the movement of the wafer stage WST and the measurement stage MST.
As shown in FIG. 2, the wafer stage WST includes a wafer stage main body 28 disposed on the base plate 12 and a Z tilt drive mechanism not shown on the wafer stage main body 28. The wafer table WTB mounted therethrough is provided. The Z tilt drive mechanism actually includes three actuators (for example, a voice coil motor or an electromagnet) that supports the wafer table WTB at three points on the wafer stage main body 28, and the wafer table. (WTB) is minutely driven in three degrees of freedom in the Z-axis direction, the θx direction (the rotation direction around the X axis) and the θy direction (the rotation direction around the Y axis).
The wafer stage main body 28 is constituted by a hollow member having a rectangular cross section and extending in the X-axis direction. A plurality of, for example, four gas static pressure bearings, for example, air bearings, for example, air bearings are provided on the lower surface of the wafer stage main body 28, and the wafer stage WST guides the above described air guides through these air bearings. It is floated and supported non-contactly with a clearance of several micrometers from the upper surface.
Above the convex part FCa of the said frame caster FC, as shown in FIG. 2, the stator 86 for Y-axis extended in a Y-axis direction is arrange | positioned. Similarly, above the convex part FCb of the frame caster FC, the stator 87 for Y axes extended in the Y-axis direction is arrange | positioned. These Y-axis stators 86 and 87 are lifted and supported with a predetermined clearance with respect to the upper surfaces of the convex portions FCa and FCb by gas static pressure bearings, for example, air bearings, which are not provided on each lower surface. . The stator for 86, 87 for Y-axis is comprised as this magnetic pole unit which consists of several permanent magnet group in this embodiment.
Inside the wafer stage main body 28, a magnetic pole unit 90 having a permanent magnet group as a mover in the X-axis direction is formed.
In the inner space of the magnetic pole unit 90, an X-axis stator 80 extending in the X-axis direction is inserted. This X-axis stator 80 is comprised by the armature unit which embeds the some armature coil arrange | positioned at predetermined intervals along the X-axis direction. In this case, the moving magnet type X-axis linear motor which drives the wafer stage WST in the X-axis direction is comprised by the X-axis stator 80 which consists of the magnetic pole unit 90 and the armature unit. In the following, the X-axis linear motor is appropriately referred to as the X-axis linear motor 80 using the same reference numeral as the stator (Stator for X-axis: 80). In addition, a moving coil type linear motor may be used instead of the moving magnet type linear motor.
Movators 82 and 83 made up of armature units having a plurality of armature coils arranged at predetermined intervals along the Y-axis direction at one end in the longitudinal direction and the other side of the stator 80 for the X axis, for example. Are fixed respectively. Each of these movable members 82 and 83 is inserted into each of the above-described Y-axis stators 86 and 87 from the inside. That is, in this embodiment, the moving coil type | mold Y-axis linear motor is comprised by the movable bodies 82 and 83 which consist of an armature unit, and the stator 86 and 87 for Y axes which consist of a pole unit. In the following, each of the two Y-axis linear motors will also be appropriately referred to as Y-axis linear motor 82 and Y-axis linear motor 83 by using the same reference numerals as the respective movers 82 and 83. do. As the Y-axis linear motors 82 and 83, a moving magnet type linear motor may be used.
That is, the wafer stage WST is driven in the X-axis direction by the X-axis linear motor 80 and is integrally Y with the X-axis linear motor 80 by the pair of Y-axis linear motors 82 and 83. Driven in the axial direction. In addition, the wafer stage WST is rotationally driven also in the? Z direction by slightly different driving force in the Y axis direction generated by the Y axis linear motors 82 and 83.
On the wafer table WTB, a wafer holder 70 holding the wafer W is provided. The wafer holder 70 is provided with a plate-shaped main body and an auxiliary plate having a circular opening which is fixed to the upper surface of the main body and whose diameter is about 2 mm larger than the diameter of the wafer W in the center thereof. A large number of fins are arranged in the body portion region inside the circular opening of the auxiliary plate, and vacuum suction is carried out while the wafer W is supported by the plurality of fins. In this case, in the state in which the wafer W is vacuum-adsorbed, the height of the surface of the wafer W and the auxiliary plate surface is approximately the same height.
Moreover, as shown in FIG. 2, on the upper surface of the wafer table WTB, an X moving mirror 17X having a reflecting surface orthogonal to the X axis at one end (-X side end) in the X axis direction extends in the Y axis direction. A Y moving mirror 17Y having a reflecting surface orthogonal to the Y axis is provided at one end (+ Y side end) in the Y axis direction to extend in the X axis direction. As shown in FIG. 2, the reflection surfaces of these moving mirrors 17X and 17Y are provided from the X-axis interferometer 46 and the Y-axis interferometer 18, which constitute the interferometer system 118 (see FIG. 7) described later. The interferometer beams (side beams) are projected respectively, and the respective interferometers 46 and 18 receive the respective reflected light, so that the reference position of each reflecting surface (usually on the side of the projection unit PU or off-axis) ) The displacement of the measurement direction from the alignment system ALG (refer FIG. 7, FIG. 8 (a) etc.) is arrange | positioned and it is made into the reference surface) is measured. The Y axis interferometer 18 has a side axis parallel to the Y axis connecting the projection center (optical axis AX) of the projection optical system PL and the detection center of the alignment system ALG, and the X axis interferometer 46 ) Has a side axis perpendicular to the side axis of the Y-axis interferometer 18 and the projection center of the projection optical system PL (see FIG. 8 (a) and the like).
The Y-axis interferometer 18 is a multi-axis interferometer having at least three optical axes, and the output value of each optical axis can be measured independently. As shown in FIG. 7, the output value (measurement value) of the Y-axis interferometer 18 is supplied to the main controller 20, and in the main controller 20 based on the output value from the Y-axis interferometer 18. Not only the position (Y position) of the wafer table WTB in the Y axis direction, but also the amount of rotation (pitching amount) around the X axis and the amount of rotation (yawing amount) around the Z axis can be measured. . In addition, the X-axis interferometer 46 is a multi-axis interferometer having at least two optical axes, the output value of each optical axis can be measured independently. The output value (measurement value) of this X-axis interferometer 46 is supplied to the main controller 20, and in the main controller 20, X of the wafer table WTB is based on the output value from the X-axis interferometer 46. Not only the position (X position) in the axial direction, but also the amount of rotation (rolling amount) around the Y axis can be measured.
As described above, the moving mirrors 17X and 17Y are actually provided on the wafer table WTB, but in Fig. 1, they are represented as the moving mirrors 17 representatively. For example, you may mirror-process the cross section of the wafer table WTB, and may form a reflecting surface (corresponding to the reflecting surface of the above-mentioned moving mirrors 17X and 17Y).
As shown in FIG. 2, the said measurement stage MST is comprised by the combination of several members, such as the Y stage 81 which makes X-axis direction the longitudinal direction, and the lowest surface (most in the base board 12) A plurality of gas static pressure bearings, for example, air bearings, provided on the lower surface of an adjacent member (eg, air bearings) are lifted and held in a non-contact manner with a clearance of several μm above the upper surface (guide surface) of the base plate 12.
As can be seen from the perspective view of Fig. 3 (a), the measurement stage MST is a measurement stage main body 81c having an elongated rectangular plate shape in the X axis direction and the X axis of the upper surface of the measurement stage main body 81c. Y stage 81 having a pair of protrusions 81a and 81b fixed to one side and the other side of the direction, a leveling table 52 disposed above the upper surface of the measurement stage main body 81c, and the leveling table 52 The measurement table MTB which comprises at least one part of the measurement unit formed on () is provided.
A mover comprising an armature unit having a plurality of armature coils arranged at predetermined intervals along the Y-axis direction on one side and the other end surface of the measurement stage main body 81c constituting the Y stage 81 ( 84 and 85 are respectively fixed. Each of these movable members 84 and 85 is inserted into the above-described Y-axis stator 86 and 87 from the inside, respectively. That is, in this embodiment, the two moving coil type Y-axis linear motors are comprised by the movable bodies 84 and 85 which consist of an armature unit, and the stator 86 and 87 for Y-axis which consist of a pole unit. In the following, each of the two Y-axis linear motors will also be appropriately referred to as Y-axis linear motor 84 and Y-axis linear motor 85 using the same reference numerals as the respective movers 84 and 85. . In this embodiment, these Y-axis linear motors 84 and 85 drive the whole measurement stage MST in a Y-axis direction. The Y-axis linear motors 84 and 85 may also be moving magnet type linear motors.
On the bottom face of the measurement stage main body 81c, a plurality of gas static pressure bearings described above are provided. The pair of protrusions 81a and 81b described above are fixed to each other near one side of the X-axis direction on the upper surface of the measurement stage main body 81c and the other side of the -Y side. Between these protrusions 81a and 81b, stators 61 and stators 63 extending in the X-axis direction, respectively, are disposed at predetermined intervals in the Z-axis direction (up and down), and both ends of the stators 61 and 63 are disposed. Is fixed to the protrusions 81a and 81b, respectively.
The mover of the X voice coil motor 54a is provided in the + X side cross section of the leveling table 52, and the stator of the X voice coil motor 54a is fixed to the upper surface of the measurement stage main body 81c. Moreover, the movers of Y voice coil motors 54b and 54c are respectively provided in the + Y cross section of the leveling table 52, and the stator of these Y voice coil motors 54b and 54c is fixed to the upper surface of the measurement stage main body 81c. It is. The X voice coil motor 54a is constituted by, for example, a mover made of a magnetic pole unit and a stator made of an armature unit, and generates a driving force in the X axis direction by electronic interaction therebetween. Moreover, the said Y voice coil motors 54b and 54c are comprised similarly, and generate the driving force of a Y-axis direction. That is, the leveling table 52 is driven in the X axis direction with respect to the Y stage 81 by the X voice coil motor 54a, and is connected to the Y stage 81 by the Y voice coil motors 54b and 54c. Drive in the Y axis direction. Moreover, by varying the driving force generated by the voice coil motors 54b and 54c, the leveling table 52 can be driven in the rotational direction (θz direction) around the Z axis with respect to the Y stage 81.
As the leveling table 52 is schematically shown in cross section in FIG. 4, the outer surface of which the bottom surface is opened is made of a plate-shaped case body, and inside of the three leveling tables 52 generates a driving force in the Z-axis direction. The Z voice coil motor 56 (however, not shown with respect to the Z voice coil motor 56 inside from the ground) is disposed respectively. The stator of each Z voice coil motor 56 is made of an armature unit, and is fixed to an upper surface of the measurement stage main body 81c. Moreover, the mover of each Z voice coil motor 56 consists of a magnetic pole unit, and is fixed to the leveling table 52. As shown in FIG. These three Z voice coil motors 56 generate a driving force in the Z-axis direction by electromagnetic interaction between each stator and the mover. Accordingly, the leveling table 52 is driven in the Z-axis direction by the three Z voice coil motors 56, while in the rotational direction (θx direction) around the X axis, and in the rotational direction (θy direction) around the Y axis. It is also designed to drive minutely.
That is, the leveling table 52 is divided into six degrees of freedom (X, Y, by the X voice coil motor 54a, the Y voice coil motors 54b, 54c, and the three Z voice coil motors 56). Z, [theta] x, [theta] y, [theta] z) can be minutely driven in a non-contact manner.
Moreover, inside the said leveling table 52, as shown in FIG. 4, the self weight canceling mechanism 58 which cancels the own weight of the leveling table 52 is also arrange | positioned. That is, the self-weight canceling mechanism 58 can also be said to compensate for the self-weight of the measurement table MTB. This self-weight canceling mechanism 58 is arrange | positioned in the vicinity of the substantially center of gravity position of the triangle comprised by the three Z voice coil motors 56 mentioned above.
As shown in the longitudinal cross-sectional view of FIG. 5, the self-weight canceller 58 has the cylindrical cylinder part 170A in which the lower end part (-Z side edge part) was opened, and the upper end part (+ Z end part) was closed, and the cylinder part ( A piston portion 170B is inserted into the inside of 170A through the opening and is movable relative to the cylinder portion 170A.
In the cylinder portion 170A, an annular first annular convex portion 172a is formed near the lower end portion (-Z side end portion) over the entire circumference of the inner circumferential surface thereof. Moreover, the 2nd annular convex part 172b is formed in the lower side (-Z side) of the 1st annular convex part 172a at predetermined intervals. And the inner space of the cylinder part 170A is in the inner bottom face of the annular recessed groove 172d of predetermined depth formed between the 1st annular convex part 172a and the 2nd annular convex part 172b of the cylinder part 170A. A plurality of through holes 172c communicating with the outside are formed at predetermined intervals.
The piston portion 170B is inserted into the cylinder portion 170A in a state in which a predetermined clearance is formed between the outer circumferential surface and the first and second annular protrusions 172a and 172b.
The piston portion 170B has a cylindrical shape in which a stage is formed of a cylindrical portion having a first diameter and two portions of a disc portion having a second diameter (> first diameter) provided on the -Z side and concentric with the cylindrical portion. Have In this piston portion 170B, a vent pipe 174a in the Z axis direction that reaches from the center portion of the upper end surface to the bottom surface is formed. The vent pipe 174a communicates with the groove 174b formed in the lower end surface (-Z side end surface) of the piston part 170B, and near the lower end surface of the piston part 170B, the lower end surface becomes close. It is processed so that it gets narrower. That is, the lower end part of the vent pipe 174a is formed so that it may serve as a kind of nozzle (taper nozzle). In addition, the groove 174b has a shape which actually combines a circle and a cross perpendicular to the center thereof.
In addition, in the vicinity of the periphery of the upper end surface of the piston section 170B, four vent pipes 176 are provided at intervals of 90 ° of the center angle (however, in Fig. 5, two vent pipes respectively located on the + Y side and the -Y side (176). ) Is shown in the state where only the remaining two vent pipes 176 located at the + X side and the -X side, respectively, are dug up to a position slightly above the central portion in the height direction of the piston portion 170B. have. In the vicinity of the lower end of these four pipes 176, a throttle hole 178 serving as a gas blowing port communicating with the outside of the outer circumferential surface of the piston 170B is formed.
In this case, the space 180 of a substantially airtight state is formed above the piston part 170B in 170 A of cylinder parts. One end of an air supply pipe (not shown) is connected to the space 180 through an opening (not shown) formed in a part of the cylinder portion 170A, and the other end of the air supply pipe is connected to a gas supply device (not shown). have. From the gas supply device, for example, a rare gas such as helium or a gas such as nitrogen or air is supplied into the space 180 through an air supply pipe, and the space 180 is formed of the cylinder 170A. It is a positive pressure space with a higher air pressure than the outside. Therefore, hereinafter, the space 180 will be referred to as "positive pressure space 180".
In the self-weight canceller 58 configured in this manner, as shown in FIG. 6, the space 180 becomes a positive pressure space so that the flow of the gas indicated by the arrow A 1 in the vent pipe 174a (hereinafter, appropriately referred to as “flow”). (Also called "A 1 )"). The gas represented by this flow A 1 is ejected from the taper nozzle part at the lower end of the vent pipe 174a described above, and a flow of the gas indicated by arrow A 2 occurs in the groove 174b. This gas spreads to the whole area | region of the groove | channel 174b, and is ejected toward the upper surface of the measurement stage main body 81c from the whole groove | channel 174b. Thereby, between the bottom face of the piston part 170B and the top face of the measurement stage main body 81c by the static pressure (in-gap pressure) of the gas between the bottom face of the piston part 170B and the upper surface of the measurement stage main body 81c. Predetermined clearance ΔL 1 is formed. That is, substantially a kind of gas static pressure bearing is provided in the bottom face of the piston part 170B, and the piston part 170B is floating non-contactedly supported above the measurement stage main body 81c. Hereinafter, this gas static pressure bearing is also called "thrust bearing."
Similar to the vent pipe 174a, each of the four vent pipes 176 generates a gas flow indicated by the arrow B 1 , and with this, the throttle hole 178 has an internal portion of the piston 170B. The flow of the gas indicated by the arrow B 2 from the outside to the outside occurs, and the gas ejected from the throttle hole 178 is injected to the second annular projection 172b. At this time, the outer circumferential surface of the piston portion 170B and the first and second annular convex portions 172a, by the positive pressure (in-gap pressure) of the gas between the second annular convex portion 172b and the outer peripheral surface of the piston portion 170B, A predetermined clearance ΔL 2 is formed between the 172b). That is, the gas static pressure bearing is substantially provided in the circumferential wall of the piston part 170B, and the piston part 170B and the cylinder part 170A are non-contact. Hereinafter, this gas static pressure bearing is also called a "radial bearing".
In addition, a plurality of through holes 172c formed in the annular concave groove 172d of the cylinder portion 170A at a predetermined interval generate a flow of gas indicated by the arrow C 1 , whereby the second annular convex portion 172b. ) is a gas, gas and the like in the positive pressure space 180, the gas in the clearance (ΔL 2) injected as is to be discharged to the outside.
According to the self-weight canceller 58 of the present embodiment, when the leveling table 52 is supported at the upper end portion thereof, the self-weight is supported by the positive pressure in the positive pressure space 180 and constitutes the Y stage 81. The clearance ΔL 1 can be maintained at all times by the action of the thrust bearing between the upper surface of the measurement stage main body 81c. In addition, even if a force that it tries to lean to the leveling table 52 in an oblique direction (θx, θy direction) occurs, so to keep the clearances (ΔL 2) by the action of the radial bearing, the inclination of the leveling table 52 Will be absorbed. Therefore, according to the self-weight canceler 58, it is possible to support the leveling table 52 at low rigidity by positive pressure, and to absorb the inclination.
Returning to FIG. 3 (a), the measurement table MTB has a measurement table main body 59 made of a material such as zero-dua (trade name of SHOT Corporation) and the -Y side of the measurement table main body 59. The cross section having the X-axis direction as the longitudinal direction fixed and aligned up and down is provided with the substantially U-shaped movable bodies 62 and 64. As shown in FIG.
Plural, for example, four air bearings 42 (see FIG. 4) are provided on the bottom surface of the measurement table main body 59, and the measurement table MTB is provided with a leveling table 52 through these air bearings 42. ) It is floated and supported non-contactly with a clearance of several μm above the upper surface.
The mover 62 includes an N-pole permanent magnet and an S-pole, which are alternately arranged at predetermined intervals along the X-axis direction on the inner surface of the movable yoke and the inner surface (upper and lower surface) of the movable yoke of which the YZ cross section is substantially U-shaped. A permanent magnet group composed of a plurality of sets of permanent magnets is provided, and is engaged with the stator 61 described above. An alternating magnetic field is formed in the inner space of the movable yoke of the movable element 62 along the X axis direction. The stator 61 is made of, for example, an armature unit containing a plurality of armature coils arranged at predetermined intervals along the X axis direction. That is, the stator 61 and the movable element 62 constitute a moving magnet type X-axis linear motor LX for driving the measurement table MTB in the X-axis direction.
The mover 64 includes a movable yoke having a substantially U-shaped YZ cross section and an N-pole permanent magnet and an S-pole permanent magnet each formed on the inner surface (upper and lower surface) of the movable yoke, and the stator described above. It is in the state fitted to (63). A magnetic field in the + Z direction or the -Z direction is formed in the inner space of the mover yoke of the mover 64. The stator 63 has an armature coil disposed therein by an arrangement in which current flows only in the X-axis direction among magnetic fields formed by the N pole magnets and the S pole magnets. That is, the movable magnet 64 and the stator 63 constitute a moving magnet type Y voice coil motor VY for driving the measurement table MTB in the Y axis direction.
As can be seen from the description so far, in the present embodiment, a fine motion mechanism (not shown) and a measurement stage (MST) that drive the Y-axis linear motors 82 to 85, the X-axis linear motors 80, and the wafer table WTB. The stage drive part 124 shown in FIG. 7 is comprised by each motor 54a-54c, 56, LX, VY of the above-mentioned. Various drive mechanisms constituting the stage drive unit 124 are controlled by the main controller 20 shown in FIG. 7.
The measurement table MTB further includes measurement instruments for performing various measurements related to exposure. If this is demonstrated further in detail, the plate 101 which consists of glass materials, such as zero-dua (trade name of SHOT Corporation) and quartz glass, is provided in the upper surface of the measurement table main body 59, for example. The surface of the plate 101 is coated with chromium over almost the entire surface thereof, and the plural portions disclosed in the area for measuring instruments and in Japanese Patent Application Laid-open No. Hei 5-21314 and US Pat. No. 5,243,195 corresponding thereto. The reference mark area FM in which the reference mark was formed is formed. To the extent permitted by the national legislation of the designated country (or selected selected country) specified in this international application, this publication and the disclosure of the corresponding US patent are incorporated herein by reference.
Patterning is performed in the said measuring device area | region, and the various opening patterns for a measurement are formed. As this measurement opening pattern, for example, the opening pattern for spatial image measurement (for example, a slit-shaped opening pattern), the pinhole opening pattern for illumination nonuniformity measurement, the opening pattern for illuminance measurement, and the opening pattern for wavefront aberration measurement Etc. are formed.
In the measurement table main body 59 below the aperture pattern for spatial image measurement, the exposure light irradiated onto the plate 101 through the projection optical system PL and water is received through the aperture pattern for spatial image measurement. A light receiving system is formed, and is projected by, for example, the projection optical system PL disclosed in Japanese Unexamined Patent Application Publication No. 2002-14005 and the corresponding US Patent Application Publication No. 2002/0041377 specification and the like. The spatial image measuring device which measures the light intensity of the spatial image (projection image) of a pattern is comprised.
Moreover, the light receiving system containing a light receiving element is formed in the inside of the measurement table main body 59 below the pinhole opening pattern for illumination nonuniformity measurement, and by this, Unexamined-Japanese-Patent No. 57-117238 and this correspond The illuminance nonuniformity measuring instrument which has the pinhole light receiving part which receives illumination light IL on the image surface of projection optical system PL disclosed in US Patent No. 4,465,368 etc. is comprised.
In addition, a light receiving system including a light receiving element is formed inside the measurement table main body 59 under the aperture pattern for illuminance measurement, and this corresponds to, for example, Japanese Patent Application Laid-Open No. 11-16816 and this. The illuminance monitor which has a light receiving part of a predetermined area which receives illumination light IL through water on the image surface of the projection optical system PL which is disclosed by Unexamined-Japanese-Patent No. 2002/0061469 specification etc. is comprised. To the extent permitted by the national legislation of the designated country (or selected selected country) specified in this international application, each publication and the disclosure of the corresponding US patent or US patent application publication are incorporated herein by reference.
Moreover, the light receiving system containing a microlens array is formed in the inside of the measurement table main body 59 below the opening pattern for wavefront aberration measurement, for example, International Publication No. 99/60361 A wavefront aberration measuring instrument disclosed in the pamphlet and European Patent No. 1,079,223 corresponding thereto is provided.
7, the spatial image measuring instrument, illuminance nonuniformity measuring instrument, illuminance monitor, and wavefront aberration measuring instrument are shown as the measuring instrument group 43. In FIG.
In addition, in this embodiment, in response to performing immersion exposure which exposes the wafer W by exposure light (lighting illumination IL) through projection optical system PL and water, it measures to the measurement using illumination light IL. In the above-described illuminance monitor, uneven illuminance measuring instrument, space image measuring instrument, wavefront aberration measuring instrument, and the like, the illumination light IL is received through the projection optical system PL and water. For this reason, the surface of the plate 101 is given water repellent coating. In addition, each said measuring device may be equipped with only a part of an optical system etc. in the measurement stage MST, for example, and may arrange | position the whole measuring instrument in the measurement stage MST.
On the upper surface of the measurement table MTB (plate 101), an X moving mirror 117X having a reflecting surface orthogonal to the X axis is provided at one end in the X axis direction (-X side end) and extended in the Y axis direction. , Y moving mirror 117Y having a reflecting surface orthogonal to the Y axis at one end (−Y side end) in the Y axis direction extends in the X axis direction. As shown in FIG. 2, the interferometer beam (side beam) from the Y-axis interferometer 16 constituting the interferometer system 118 is projected onto the reflecting surface of the Y moving mirror 117Y, and the reflected light is emitted from the interferometer 16. By receiving the light, the displacement from the reference position of the reflective surface of the Y moving mirror 117Y is measured. In addition, when the measurement table MTB moves just below the projection unit PU at the time of measurement, etc., the interferometer beam (measured beam) from the X-axis interferometer 46 is projected on the reflecting surface of the X moving mirror 117X. In the interferometer 46, the reflected light is received to measure the displacement from the reference position of the reflection surface of the X moving mirror 117X. The Y axis interferometer 16 has a side axis parallel to the Y axis direction perpendicular to the side axis of the X axis interferometer 46 described above at the projection center (optical axis AX) of the projection optical system PL. have.
The Y-axis interferometer 16 is a multi-axis interferometer having at least three optical axes, and the output value of each optical axis can be measured independently. The output value (measurement value) of this Y-axis interferometer 16 is supplied to the main control apparatus 20, as shown in FIG. 7, and the main control apparatus 20 is based on the output value from the Y-axis interferometer 16. Not only the Y position of the measurement table MTB, but also the pitching amount and yaw amount can be measured. In addition, in the main control device 20, the X position and the rolling amount of the measurement table MTB are measured based on the output value from the X-axis interferometer 46.
As can be seen from the description so far, in the present embodiment, the interferometer beam from the Y axis interferometer 18 is always projected onto the moving mirror 17Y in the entire region of the movement range of the wafer stage WST, and the Y axis interferometer The interferometer beam from 16 is always projected on the moving mirror 117Y in the entire region of the movement range of the measurement stage MST. Therefore, in the Y axis direction, the positions of the stages WST and MST are always managed by the main controller 20 based on the measured values of the Y axis interferometers 18 and 16.
On the other hand, as easily imagined also from FIG. 2, the main controller 20 outputs the X-axis interferometer 46 only in a range in which the interferometer beam from the X-axis interferometer 46 touches the moving mirror 17X. X-axis interferometer 46 only manages the X position of the wafer table WTB (wafer stage WST) based on the values, and only in the range in which the interferometer beam from the X-axis interferometer 46 touches the moving mirror 117X. The X position of the measurement table MTB (measurement stage MST) is managed based on the output value of. Therefore, the position of the wafer table WTB and the measurement table MTB while the X position cannot be managed based on the output value of the X axis interferometer 46 is measured by an encoder (not shown). Based on the measured values of the encoder, the main controller 20 manages the positions of the wafer table WTB and the measurement table MTB while the X position cannot be managed based on the output values of the X-axis interferometer 46. do.
In addition, the main control unit 20 starts at the point immediately after the interferometer beam from the X-axis interferometer 46 does not reach anywhere of the moving mirrors 17X and 117X and starts to reach the moving mirror 17X or the moving mirror 117X and start touching. Resetting the X-axis interferometer 46, which was not used for control until then, and then using the Y-axis interferometer 18 or 16 and the X-axis interferometer 46, which constitute the interferometer system 118, The position of the wafer stage WST or the measurement stage MST is managed.
In this embodiment, although the interferometer system 118 of FIG. 7 is comprised including two Y-axis interferometers 16 and 18 and one X-axis interferometer 46, a plurality of X-axis interferometers are formed and always An arrangement in which the interferometer beams from several X-axis interferometers touch the moving mirrors 17X and 117X may be adopted. In this case, what is necessary is just to switch the X-axis interferometer which manages the position of the wafer stage WST and the measurement stage MST according to the X position of these stages.
Moreover, the above-mentioned multi-axis interferometer inclines 45 degrees, and irradiates a laser beam to the reflecting surface provided in the holding member which hold | maintains the projection unit PU through the reflecting surface provided in the stage WST, MST, and the reflecting surface And relative positional information regarding the optical axis direction (Z axis direction) of the projection optical system PL of the stage.
Moreover, in the exposure apparatus 100 of this embodiment, the holding member holding the projection unit PU is abbreviated as an off-axis alignment system (hereinafter referred to as "alignment system": ALG) (not shown in FIG. 1, 7 and 8 (a) and the like) are formed. The alignment system ALG, for example, irradiates a target mark with a detection light beam, which is a broadband that does not expose the resist on the wafer, and shows an image and an illustration of the target mark formed on the light receiving surface by the reflected light from the target mark. An image of an unindexed index (indicator pattern on an index plate formed in the alignment system ALG) is imaged using an imaging device (CCD, etc.), and an image processing method FIA (Field Image Alignment) system of an image processing method for outputting these captured signals is provided. The sensor is being used. The imaging signal from alignment system ALG is supplied to main controller 20 of FIG.
The alignment system ALG is not limited to the FIA system, but irradiates coherent detection light to a target mark, detects scattered light or diffracted light generated from the target mark, or generates 2 from the target mark. It is of course possible to use an alignment sensor that detects by interfering two diffracted light (for example, diffracted light of the same order or diffracted light diffracted in the same direction) alone or in appropriate combination.
In the exposure apparatus 100 of this embodiment, although illustration is abbreviate | omitted in FIG. 1, For example, Unexamined-Japanese-Patent No. 6-283403 consists of the irradiation system 90a and the light receiving system 90b (refer FIG. 7). A multi-point focal position detection system of an incidence method similar to that disclosed in US Pat. No. 5,448,332 or the like corresponding thereto is provided. In this embodiment, as an example, the irradiation system 90a is supported by the holding member holding the projection unit PU on the -X side of the projection unit PU, and the light receiving system 90b is + X of the projection unit PU. It is supported by hanging below the holding member from the side. That is, the irradiation system 90a, the light receiving system 90b, and the projection optical system PL are attached to the same member, and the positional relationship of both is kept constant. To the extent permitted by the national legislation of the designated country (or selected selected country) specified in this international application, this publication and the disclosure of the corresponding US patent are incorporated herein by reference.
The main structure of the control system of the exposure apparatus 100 is shown by FIG. This control system is comprised centering on the main control apparatus 20 which consists of a microcomputer (or workstation) which controls the whole apparatus collectively. In addition, a display DIS such as a memory MEM, a CRT display (or a liquid crystal display) is connected to the main controller 20.
Next, about parallel processing operation | movement which used the wafer stage WST and the measurement stage MST in the exposure apparatus 100 of this embodiment comprised as mentioned above, FIGS. 8A-10. It demonstrates based on. In addition, during the following operation, opening and closing control of each valve of the liquid supply apparatus 288 of the liquid immersion apparatus 132 and the liquid collection | recovery apparatus 292 is performed by the main control apparatus 20 as mentioned above, and a projection optical system Water is always filled immediately below the front end lens 91 of the PL. However, in the following, the description regarding the control of the liquid supply device 288 and the liquid recovery device 292 is omitted for clarity of explanation.
Fig. 8A shows the step-and-scan exposure of the wafer W on the wafer stage WST (here, for example, the last wafer of one lot (one lot is 25 or 50 sheets)). The state in which this is carried out is shown. At this time, the measurement stage MST is waiting at a predetermined waiting position which does not collide with the wafer stage WST.
The exposure operation is performed by the main controller 20 beforehand, for example, as a result of wafer alignment such as Enhanced Global Alignment (EGA) and the baseline of the latest alignment system ALG. Based on the measurement result or the like, the inter-short movement operation in which the wafer stage WST is moved to the scanning start position (acceleration start position) for exposure of each shot region on the wafer W, and the pattern formed on the reticle R are each This is performed by repeating the scanning exposure operation that is transferred to the shot region by the scanning exposure method.
Here, in the short-term movement operation in which the wafer stage WST is moved, the main controller 20 monitors the measured values of the interferometers 18 and 46, while the X-axis linear motor 80 and the Y-axis linear motor ( 82, 83 to control the operation. Further, the scanning exposure is performed by the main controller 20 while monitoring the measured values of the interferometers 18 and 46 and the reticle interferometer 116, and the reticle stage driver 11 and the Y-axis linear motors 82 and 83 (and By controlling the X-axis linear motor 80, the reticle R (reticle stage RST) and the wafer W (wafer stage WST) are scanned relative to the Y axis direction, and the acceleration during the relative scanning is performed. At the constant velocity movement between the end and just before deceleration start, the reticle R (reticle stage RST) and the wafer W (wafer stage WST) with respect to the illumination region of the illumination light IL with respect to the Y axis direction. It is realized by moving at constant speed. In addition, the said exposure operation is performed in the state hold | maintained water between the front-end | tip lens 91 and the wafer W. As shown in FIG.
And at the stage where the exposure with respect to the wafer W was complete | finished on the wafer stage WST side, the main control unit 20 is a Y-axis linear motor based on the measured value of the interferometer 16, and the measured value of the encoder which is not shown in figure. (84, 85) and the X-axis linear motor LX are controlled to move the measurement table MTB to the position shown in FIG. 8 (b). In the state of FIG. 8B, the + Y side cross section of the measurement table MTB and the −Y side cross section of the wafer table WTB are in contact with each other. In addition, the measured values of the interferometers 16 and 18 may be monitored to separate the measurement table MTB and the wafer table WTB about 300 µm with respect to the Y-axis direction to maintain a non-contact state.
Next, the main controller 20 starts an operation of simultaneously driving both stages WST and MST in the + Y direction while maintaining the positional relationship in the Y axis direction between the wafer table WTB and the measurement table MTB. .
In this way, when the wafer stage WST and the measurement stage MST are driven simultaneously by the main controller 20, in the state of FIG. 8 (b), the front end lens 91 of the projection unit PU and the wafer W are used. The water retained between the wafers 1) moves on the wafers W → wafer holder 70 → the measurement table MTB in sequence with movement to the + Y side of the wafer stage WST and the measurement stage MST. In addition, during the movement, the wafer table WTB and the measurement table MTB maintain the positional relationship in contact with each other. In FIG. 9 (a), the water is present on the wafer stage WST and the measurement stage MST at the same time during the above-described movement, that is, the water flows from the wafer stage WST to the measurement stage MST. The state just before the transfer is shown.
When the wafer stage WST and the measurement stage MST are simultaneously driven a predetermined distance in the + Y direction from the state of Fig. 9A, as shown in Fig. 9B, the measurement table MTB and the tip lens ( 91) the state of water is maintained. Prior to this, the main controller 20 resets the X-axis interferometer 46 at a point in time at which the interferometer beam from the X-axis interferometer 46 is irradiated to the moving mirror 117X on the measurement table MTB. Is running. In addition, in the state of FIG. 9B, the main controller 20 manages the X position of the wafer table WTB (wafer stage WST) based on measured values of an encoder (not shown).
Next, the main control unit 20 controls the linear motors 80, 82, 83 while managing the position of the wafer stage WST based on the interferometer 18 and the measured values of the encoder, and controls the position of the wafer stage WST at a predetermined wafer exchange position. The wafer stage WST is moved and the next lot is replaced with the first wafer, and in parallel with this, a predetermined measurement using the measurement stage MST is performed as necessary. As this measurement, the baseline measurement of the alignment system ALG performed after reticle replacement on the reticle stage RST is mentioned as an example. Specifically, in the main controller 20, the reticle described above with the reticle alignment mark on the reticle corresponding to the pair of first reference marks in the reference mark region FM formed on the plate 101 on the measurement table MTB. It simultaneously detects using alignment systems RAa and RAb, and detects the positional relationship of a pair of 1st reference mark and the reticle alignment mark corresponding to it. At the same time, in the main control device 20, by detecting the second reference mark in the reference mark area FM with the alignment system ALG, the positional relationship between the detection center of the alignment system ALG and the second reference mark is determined. Detect. The main control unit 20 includes a positional relationship between the pair of first reference marks and a reticle alignment mark, a positional relationship between a detection center of the alignment system ALG and the second reference mark, and a pair of existing Based on the positional relationship between the first reference mark and the second reference mark, the distance between the projection center of the reticle pattern by the projection optical system PL and the detection center of the alignment system ALG, that is, the base line of the alignment system ALG is determined. Obtain In addition, the state at this time is shown in FIG.
In addition, a plurality of pairs of reticle alignment marks are formed on the reticle together with the measurement of the base line of the alignment system ALG, and correspondingly, a plurality of pairs of first reference marks are formed in the reference mark region FM. The reticle alignment systems RAa and RAb are used to move the relative positions of the at least two pairs of the first reference marks and the reticle alignment marks corresponding to the reticle stage RST and the wafer stage WST in the Y axis direction. By measuring, so-called reticle alignment is performed.
In this case, detection of the mark using the reticle alignment systems RAa and RAb is performed through the projection optical system PL and water.
Then, at the stage where the work on both stages WST and MST described above is finished, the main controller 20 moves the measurement table MTB and the wafer table WTB (wafer stage WST). While contacting and maintaining the state, the wafer is driven in the XY plane to return the wafer stage WST immediately below the projection unit. Even during this movement, the main controller 20 resets the X-axis interferometer 46 at any point in time when the interferometer beam from the X-axis interferometer 46 is irradiated to the moving mirror 17X on the wafer table WTB. Is running. Then, on the wafer stage WST side, the alignment marks on the wafer after the replacement by the wafer alignment, that is, the alignment system ALG, are detected for the wafer after the replacement, and the position coordinates of the plurality of shot regions on the wafer are calculated. As described above, the measurement table MTB and the wafer table WTB (wafer stage WST) may be in a non-contact state.
Subsequently, in the main controller 20, the two stages WST and MST are maintained, while maintaining the positional relationship in the Y-axis direction between the wafer table WTB (wafer stage WST) and the measurement table MTB, as opposed to a while ago. Is simultaneously driven in the -Y direction to move the wafer stage WST (wafer) below the projection optical system PL, and then the measurement stage MST is evacuated to a predetermined position.
Thereafter, the main controller 20 performs the step-and-scan exposure operation on the new wafer as described above, and sequentially transfers the reticle pattern to the plurality of shot regions on the wafer.
In addition, although the above description demonstrated the case where baseline measurement is performed as a measurement operation, it is not limited to this, While measuring each wafer on the wafer stage WST side, the measurement stage MST The measurement instrument group 43 may be used to perform illuminance measurement, illuminance nonuniformity measurement, spatial image measurement, wavefront aberration measurement, and the like, and reflect the measurement result to the exposure of the wafer to be performed later. Specifically, the projection optical system PL can be adjusted by the above-described imaging characteristic correction controller 381 based on the measurement result.
In this case, different measurement can be performed for each wafer exchange depending on the time required for wafer exchange. In addition, when one measurement is not completed between one wafer exchange, the measurement may be divided into multiple times.
By the way, as mentioned above, since the measurement using each said measuring instrument is performed in the state in which water was filled on the plate 101 of the measurement table MTB, the water-repellent coating is applied to the surface (upper surface) of the plate 101. It is carried out. However, since this water repellent coating is weak to ultraviolet rays and deteriorates when ultraviolet rays are irradiated for a long time, it is necessary to perform maintenance (exchange) of the water repellent coating portion at a predetermined frequency. In view of such a point, in the exposure apparatus 100 of the present embodiment, the measurement table MTB is in a non-contact state with other components of the measurement stage MST. That is, by moving the measurement table MTB to the + Y side and releasing the coupling of the mover and the stator of each of the X linear motor LX and the Y voice coil motor VY, as shown in Fig. 3 (b), The measurement table MTB can be easily removed from other components of the measurement stage MST. In this embodiment, the measurement table MTB is replaced with a new measurement table at a predetermined exchange time.
At the time when the measurement table MTB is replaced, the water-repellent coating is performed from the viewpoint of maintaining the measurement accuracy of various measurements satisfactorily and minimizing the stop time of the apparatus accompanying the replacement of the measurement table MTB. It is preferable to set it immediately before deterioration (just before deterioration exceeds a predetermined allowable range).
Therefore, in this embodiment, based on the relationship between the deterioration of the water repellent coating and the change of the measurement result of the various measuring instruments formed in the measurement table MTB by experiment in advance, the measured values of various measuring instruments immediately before the water repellent coating is deteriorated are calculated | required. In the memory MEM (see FIG. 7), the threshold value at which the measurement results of various measuring instruments exceed the allowable value is stored as a threshold value. When the measurement is performed using the measurement table MTB while the device is in use, the main controller 20 compares the measurement result with the threshold stored in the memory MEM to determine whether an exchange time has arrived. I judge it. Then, when it is determined that the replacement time has come, the main controller 20 displays the message on the display DIS (see FIG. 7). There, the operator stops the operation of the exposure apparatus 100 and executes the replacement of the measurement table MTB according to the manual. That is, in this embodiment, the detection apparatus which detects the exchange time of the plate 101 by the main control apparatus 20 and the memory MEM is comprised.
Moreover, when equipped with the robot etc. which are used for the exchange of the measurement table MTB, the main control unit 20 displays the exchange time on the display DIS, and stops operation of the apparatus, and the robot It is also possible to carry out the measurement table MTB to the outside using the etc., and to carry in a new measurement table on the measurement stage main body 81c.
In addition, detection of the timing of exchanging the measurement table MTB is performed, for example, in the vicinity of the projection unit PU by using optical fiber or the like for light (detection light) having the same wavelength as the exposure light, separately from the exposure light. And irradiating the detected light to a portion other than the portion used for various measurements of the plate 101 of the measurement table MTB for the same (or slightly longer) time as the measurement time, and the illuminance of the detected light at that time (light quantity ) And the like may be measured by an optical sensor provided exclusively for replacement timing detection, and the deterioration degree may be calculated based on the measurement result to determine the arrival of the replacement timing. In addition, the degree of deterioration may be predicted using a timer or the like based on the deterioration time obtained in advance by simulation or the like. The point is that the method does not matter as long as it can detect the deterioration state of the water-repellent coating using any means and detect that the exchange time has arrived.
As described above in detail, according to the exposure apparatus 100 of this embodiment, in the measurement stage MST which has the plate 101 to which water (liquid) is supplied, and performs measurement regarding exposure via a projection optical system and water, The measurement table MTB including the plate 101 is replaceable. For this reason, even when the measurement regarding exposure through the projection optical system PL and water is repeatedly performed using the measurement stage MST in the state in which water was supplied to the surface of the plate 101, the surface of the plate 101 surface. By exchanging the measurement table MTB before it deteriorates by contact with this water, the measurement regarding exposure can always be performed with high precision, and it becomes possible to maintain high precision exposure further.
Moreover, in the exposure apparatus of this embodiment, the time immediately before the measurement precision of the various measuring instruments installed in the measurement table MTB begins to fall by experiment is calculated | required in advance, and this time is previously mentioned as a replacement time of the measurement table MTB. By setting, the arrival of the time is detected by the main controller 20 in the same manner as described above. Therefore, by exchanging the measurement table MTB according to the detection result, it becomes possible to exchange the measurement table MTB at the optimum time before the measurement precision of the various measuring instruments formed in the measurement table MTB falls. That is, while the measurement precision of the measurement regarding exposure by the measurement table MTB can be maintained with high precision, the exchange frequency of the measurement table MTB can be suppressed as much as possible. Therefore, the exposure accuracy can be maintained with high accuracy over a long period of time, and it is possible to effectively prevent the decrease in device operation efficiency due to the increase in the stop time accompanying the exchange of the measurement table.
Moreover, according to the exposure apparatus 100, the pattern of the reticle R can be accurately transferred onto a wafer by performing liquid exposure by performing exposure with high resolution and a large depth of focus compared with air. For example, as a device rule, transfer of a fine pattern of about 70 to 100 nm can be realized.
In addition, in the said embodiment, although the case where the measurement stage MST is equipped with the exchangeable measurement table MTB was demonstrated, this invention is not limited to this, The measurement stage MST itself is replaceable, That is, you may employ | adopt the structure which can release | release the engagement between the stator and the mover of the Y-axis linear motor which drives a measurement stage to a Y-axis direction.
In addition, in the said embodiment, although the measurement table MTB demonstrated the case where attachment and detachment is free with respect to the leveling table 52 which comprises the measurement stage MST, this invention is not limited to this, An example is given. For example, the measurement table may be screwed to a part of the measurement stage MST. Even in such a case, it is because a measurement table can be replaced only by loosening a screw.
Moreover, in the said embodiment, although the case where the leveling table 52 employ | adopted the structure which has 6 degrees of freedom and the measurement table MTB has 3 degrees of freedom was demonstrated, it is not limited to this, The leveling table 52 is three. The degree of freedom and the measurement table MTB may adopt a configuration having three degrees of freedom. It is also possible to adopt a configuration in which the measurement table MTB has six degrees of freedom without providing the leveling table 52. In other words, the configuration may be such that at least a part of the measurement unit including the plate 101 can be replaced.
In addition, in the said embodiment, although the case where the piston-shaped self-weight canceller 58 was employ | adopted as a mechanism for canceling the self-weight of the leveling table 52 was demonstrated, it is not limited to this, It is a bellows-shaped self-weighted canceller. It is good also as employ | adopted. In addition, the weight of the wafer stage main body 28 may be canceled by the self-weight canceller 58.
Next, 2nd Embodiment of this invention is described based on FIG. Here, the same or equivalent parts as those of the above-described first embodiment are used with the same reference numerals, and the description thereof will be simplified or omitted. In the exposure apparatus of this 2nd Embodiment, the structure of the measurement stage as a measurement part, etc. differ from the above-mentioned 1st Embodiment, and the structure of other parts is made the same as the above-mentioned 1st Embodiment. Therefore, the following description will focus on differences from the viewpoint of avoiding redundant description.
In FIG. 11, the measurement stage MST 'which concerns on this 2nd Embodiment is shown by perspective view. When this FIG. 11 and FIG. 3 (a) are compared, in the measurement stage MST 'of this 2nd Embodiment, the measurement table MTB as a measurement unit instead of the measurement table MTB of 1st Embodiment mentioned above. You can see that ') is installed. The measurement table MTB 'includes a measurement table main body 159 that is slightly different from the measurement table main body 59 described above, and a plate 101' freely attached to and detached from the measurement table main body 159. ). Therefore, except for this point, the configuration is basically the same as that of the above-described measurement table MTB, and has the same function.
Like the said 1st Embodiment, the said plate 101 'is comprised from glass materials, such as zero-dua (short brand name) and quartz glass, for example, and chromium is apply | coated over almost the whole surface of the surface, In some places, areas for measuring instruments and reference mark areas are formed. And the area | region for a measuring instrument is patterned, and the opening pattern for spatial image measurement (for example, a slit-shaped opening pattern), the illumination nonuniformity measurement pinhole opening pattern, the illumination intensity measurement opening pattern similar to 1st Embodiment mentioned above is performed. And an opening pattern for measurement such as an opening pattern for wavefront aberration measurement.
In addition, the -Y side cross section and the -X side cross section of the plate 101 'are mirror-finished, and reflecting surfaces (corresponding to the reflecting surfaces of the moving mirrors 117X and 117Y on the measurement table MTB in the first embodiment). Is formed. Moreover, also in this 2nd Embodiment, since various measurements are performed in the state in which water was supplied on the plate 101 ', the water-repellent coating is given to the surface of the plate 101'.
In the second embodiment, the plate 101 'is sucked and held on the measurement table main body 159 through a vacuum chuck (not shown) provided in the measurement table main body 159. Of course, it is not limited to vacuum suction, You may fix the plate 101 'to the measurement table main body 159 using a mechanical mechanism.
It is the same as that of 1st Embodiment mentioned above that the measurement table main body 159 is provided in the inside with the several light reception system corresponding to the above-mentioned various measurement opening pattern, respectively. However, in the upper surface of this measurement table main body 159, the groove 21a extended in the X-axis direction below the area | region where the plate 101 'is mounted is formed in the center part of the Y-axis direction of + X side cross section, Grooves 21b and 21c extending in the X-axis direction to the lower side of the region where the plate 101 'is mounted are formed at one side in the Y-axis direction and the other side of the -X-side cross section, respectively.
Above the measurement stage MST 'in FIG. 11, the carrying in / out mechanism 24 used for carrying in / out of the plate 101' is provided. This carrying in / out mechanism 24 is actually provided above the edge part of the base board 12 near the -Y direction.
The carry-in / out mechanism 24 is attached to the main-body part 27 and the main-body part 27 which can perform the slide operation regarding a Y-axis direction, and the lifting operation regarding a Z-axis direction, and is a direction opposite to an X-axis direction. The two hand parts 25a and 25b which are substantially L-shaped are seen from the + Y direction which can move (move to each other, and move to the direction which is separated).
One hand part 25a is attached in the state which + X side edge part protruded to the outer side of the main body part 27, and hanged on the main body part 27, and the hook part 26a is attached to the + X side edge part. Formed. Moreover, the other hand part 25b is attached in the state supported by the main-body part 27 in the state which the -X side edge part protruded to the outer side of the main-body part 27, and is supported by the -X side edge part. , An extension portion extending in the Y axis direction is formed, and hook portions 26b and 26c are formed at the + Y side end portion and the -Y side end portion of the extension portion. The hook portions 26a, 26b, 26c are formed at approximately the same height position.
The hand portions 25a and 25b are freely slidable in the directions opposite to each other along the X-axis direction by a drive mechanism (not shown) provided in the main body portion 27 (that is, the opening and closing is free). This carry-out / out mechanism 24 is controlled by the main control device 20.
The configuration of the other parts is the same as in the first embodiment described above. Therefore, also in the exposure apparatus of this 2nd Embodiment, exposure operation and measurement operation are performed in the same procedure as the above-mentioned 1st Embodiment.
In the second embodiment, similarly to the first embodiment, the water-repellent coating is based on the relationship between deterioration of the water-repellent coating in advance and the change of the measurement result of various measuring instruments provided on the measurement table MTB 'by experiment. The measured values of the various measuring instruments immediately before the deterioration are obtained, and the value of the boundary exceeding the allowable value of the measured results of the various measuring instruments is stored in the memory MEM as a threshold value. And when measurement is performed using the measurement table MTB ', the main control apparatus 20 compares the measurement result with the threshold stored in the memory MEM, and the exchange time of the plate 101' arrives. Determine whether or not. That is, in this 2nd Embodiment, the detection apparatus which detects the arrival of the exchange time of the plate 101 'including the main control apparatus 20 and the memory MEM is comprised.
In addition, you may perform detection of the replacement time of the plate 101 'using the other method illustrated by 1st Embodiment mentioned above.
In any case, when the main controller 20 detects the replacement timing of the plate 101 '(determined that the replacement timing has arrived), it displays the arrival of the replacement timing on the display DIS and waits for an instruction from the operator. Alternatively, when detecting the replacement timing of the plate 101 '(determining that the replacement timing has arrived), the main controller 20 displays the arrival of the replacement timing on the display DIS, and performs the plate ( 101 ') is replaced.
That is, after the main controller 20 moves the carry-out / out mechanism 24 to the position shown in FIG. 11, the main body 27 is driven downward, and the hook portion 26a is opened in the state where the hand portions 25a and 25b are opened. , 26b, 26c are inserted from above into the grooves 21a, 21b, 21c described above. Then, the main controller 20 closes the hand portions 25a and 25b by a predetermined amount via the drive mechanism in the main body portion 27. Thereby, the hand part 25a is driven to the -X side, the hand part 25b is driven to the + X side, and the hook part 26a of the hand part 25a and the hook parts 26b and 26c of the hand part 25b are plate | plates. It is located below 101 ', respectively. The state at this time is shown in FIG. At this time, the hook portions 26b and 26c are not in contact with the −X side end surface of the plate 101 '.
Then, in the state of FIG. 12, the main controller 20 stops the vacuum chuck of the measurement table main body 159 to release vacuum suction of the plate 101 ′, and then moves the main body 27 in the + Z direction. By driving, the plate 101 'is lifted by the hook portions 26a to 26c. Thereafter, the main control device 20 drives the main body 27 to the predetermined height and then drives the plate 101 'to a conveying system (not shown) by driving toward the -Y side. Thereby, the plate 101 'is carried out of the exposure apparatus by the conveyance system, and the new plate 101' is conveyed by the said conveyance system to the predetermined position inside an exposure apparatus, and is waiting in the position. It is passed to the hand parts 25a, 25b of the unloading mechanism 24 which exist.
Thereafter, the main controller 20 performs the operation opposite to the above, so that the new plate 101 'is carried onto the measurement table main body 159. However, in carrying in this new plate 101 ', main controller 20 pushes the + X side cross-section of the new plate 101', etc. to the positioning pin which is not shown in the measurement table main body 159, and the like. Press to roughly perform positioning. After completion of positioning, the main controller 20 turns on the vacuum chuck (not shown) to hold the new plate 101 'on the measurement table main body 159.
In this case, since the cross section of the plate 101 'is mirror-finished as mentioned above, even if the plate 101' is roughly positioned as mentioned above, the measurement stage MST 'is performed after that. In the various measurements using, since the position of the plate 101 'can be accurately measured using an interferometer, it is consequently to perform various measurements using the measurement stage MST' with high accuracy even after the plate is replaced. It is possible.
As described above, according to the exposure apparatus of the second embodiment, a time period immediately before the measurement accuracy of various measuring instruments on the measurement table MTB 'begins to decrease is determined in advance by experiment or the like, and this time is determined by the plate 101'. By setting in advance as the replacement time, the measurement accuracy of various measuring instruments on the measurement table MTB 'is lowered by replacing the plate 101' when the main controller 20 as the detection device detects the replacement time. It is possible to replace the plate at the optimum time. That is, the measurement accuracy of the measurement regarding the exposure by the various measuring instruments on the measurement table MTB 'can be maintained with high accuracy, and the exchange frequency of a plate can be suppressed as much as possible. Therefore, the exposure accuracy can be maintained with high accuracy over a long period of time, and it is possible to effectively prevent the deterioration of the device operating efficiency due to the increase in the stop time accompanying the plate replacement.
In the second embodiment, since the plate 101 'is mirror-finished with two end faces, even when the plate 101' is replaced with a new one, even if the plate after the replacement is roughly positioned, the mirror surface of the plate Through the processed cross section, the position of the plate can be accurately measured using the interferometers 16 and 46. Therefore, even if the plate is roughly positioned at the time of exchange, the measurement table MTB constituting the measurement unit at the time of measurement can be accurately positioned at a desired position, thus eliminating the need for a long time for replacement. It becomes possible to effectively prevent the fall of the apparatus operation efficiency due to the increase in the downtime accompanying the replacement.
Moreover, also in the exposure apparatus of this 2nd Embodiment, since immersion exposure is performed, the pattern of the reticle R can be accurately transferred on a wafer.
In addition, although the plate 101 'was made replaceable in the said 2nd Embodiment, this invention is not limited to this, At least of the measurement part (the measurement table of the said 2nd Embodiment is equivalent) containing a plate here. Some may be configured to be exchangeable.
In addition, in the said 2nd Embodiment, although the cross section of the plate 101 'was mirror-processed in order to make rough positioning sufficient in the exchange of the plate 101', it is not limited to this, but mentioned above Similar to the first embodiment, the moving mirrors 117X and 117Y may be provided on the measurement table main body 159.
In addition, in the said 2nd Embodiment, since the plate should just be replaceable, the structure of the other part of a measurement stage is not limited to the structure shown in FIG. For example, you may employ | adopt the measurement stage of the structure similar to the wafer stage WST of FIG. 2, and may comprise the plate which this measurement stage is equipped so that replacement is possible.
Moreover, in the said 2nd Embodiment, although the case where the carrying-out / out mechanism 24 shown in FIG. 11 was employ | adopted as the mechanism which replaces the plate 101 'was demonstrated, it replaced with the carry-in / out mechanism 24, etc., and the like. You may employ | adopt the robot used as a carry-in / out mechanism. In this case, the structure which the edge part of a plate protrudes on both sides of the X-axis direction of the measurement table MTB 'may be employ | adopted, and the plate may be changed by lifting a plate from below by the robot arm, and a plate may be measured. The arm of the robot is inserted below the plate while the arm is moved up and down by the predetermined height to the measurement table MTB 'and the plate is lifted by the up and down mechanism. You may lift and perform plate replacement.
In addition, in each said embodiment, although the case where this invention was applied to the immersion exposure apparatus was demonstrated, it is not limited to this, Even if it is an exposure apparatus which performs exposure other than immersion, at least the measurement part is the same as the said 1st Embodiment. It is possible to replace a part (for example, to install a replaceable measuring table (or measuring stage)) or to install a replaceable plate in the same manner as in the second embodiment, and to mirror the end surface of the plate. It is effective to provide a detection device for processing and for detecting a replacement time of at least a part of the measurement unit including the plate. In this case, it is not necessary to apply a water repellent coating to the plate. However, by replacing a part of the measurement unit including the plate, it is possible to effectively prevent various degradations in measurement accuracy due to deterioration of the plate due to irradiation of high energy exposure light. to be.
In addition, in each said embodiment, although the measurement stage which comprises the measurement part which has measurement table MTB, MTB 'is provided separately from the wafer stage WST, even if a measurement part is provided in the wafer stage WST, do. In this case, at least one part including the plate of the measurement unit constituting the measurement unit may be detachable (replaceable) with respect to the wafer stage WST.
In addition, in each said embodiment, although the case where the stage apparatus provided one wafer stage and one measurement stage was demonstrated, this invention is not limited to this and improves the throughput of an exposure operation | movement. For this purpose, a plurality of wafer stages may be provided.
In addition, in each said embodiment, although ultrapure water (water) was used as a liquid, of course, this invention is not limited to this. As the liquid, a liquid which is chemically stable, has a high transmittance of illumination light IL, and is safe, for example, a fluorine-based inert liquid, may be used. As this fluorine-type inert liquid, florinate (brand name of 3M Corporation of America) can be used, for example. This fluorine-based inert liquid is also excellent in cooling effect. In addition, the liquid is transparent to the illumination light IL and has as high a refractive index as possible, and stable to a projection optical system or a photoresist applied to the wafer surface (for example, cedar oil, etc.). You can also use Further, when the F 2 laser as the light source may be selected a phone Dublin oil.
In each of the above embodiments, the recovered liquid may be reused. In this case, it is preferable that a filter for removing impurities from the recovered liquid is provided in a liquid recovery device, a recovery pipe, or the like.
In addition, in each said embodiment, although the optical element nearest to the image plane side of the projection optical system PL is the front lens 91, the optical element is not limited to a lens, but the optical characteristic of the projection optical system PL For example, the optical plate (parallel flat plate etc.) used for adjustment of aberration (spherical aberration, coma aberration, etc.) may be sufficient, and a simple cover glass may be sufficient. The optical element closest to the image plane side of the projection optical system PL (the tip lens 91 in each of the above embodiments) is due to the adhesion of scattering particles or impurities in the liquid generated from the resist by irradiation of the illumination light IL. The surface may be contaminated by contact with a liquid (water in each of the above embodiments). For this reason, the optical element may be fixed at the bottom of the barrel 40 to be freely attached or detached (exchanged) so as to be replaced periodically.
In such a case, if the optical element in contact with the liquid is a lens, the cost of the replacement part is high, and the time required for replacement becomes long, resulting in an increase in maintenance cost (running cost) or a decrease in throughput. Therefore, you may make the optical element which contacts a liquid into a parallel plane plate cheaper than the lens 91, for example.
Moreover, in each said embodiment, although the case where this invention was applied to scanning type exposure apparatuses, such as a step-and-scan system, was demonstrated, it goes without saying that the application range of this invention is not limited to this. That is, the present invention can also be applied to a projection exposure apparatus of a step-and-repeat method, an exposure apparatus of a step-and-stitch method, an exposure apparatus of a proximity method, and the like.
The use of the exposure apparatus is not limited to an exposure apparatus for semiconductor manufacturing, and for example, an exposure apparatus for a liquid crystal which transfers a liquid crystal display element pattern to a rectangular glass plate, an organic EL, a thin film magnetic head, an imaging device (CCD, etc.). It can also be widely applied to an exposure apparatus for manufacturing micro machines, DNA chips and the like. Moreover, the exposure which transfers a circuit pattern to a glass substrate or a silicon wafer etc. in order to manufacture the reticle or mask used not only in a microdevice, such as a semiconductor element, but also in an optical exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, an electron beam exposure apparatus, etc. The present invention can also be applied to an apparatus.
In addition, the light source is ArF not limited to excimer laser, KrF excimer laser (output wavelength 248㎚), F 2 laser (output wavelength 157㎚), Ar 2 excimer laser (output wavelength 126㎚) of the above-mentioned embodiments of the exposure apparatus Or a pulsed laser light source such as Kr 2 laser (output wavelength 146 nm), or an ultra-high pressure mercury lamp that emits bright rays such as g line (wavelength 436 nm) and i line (wavelength 365 nm). Moreover, the harmonic generator of a YAG laser, etc. can also be used. In addition, the infrared or visible single wavelength laser light oscillated from a DFB semiconductor laser or fiber laser is amplified by, for example, a fiber amplifier doped with erbium (or both of erbium and ytterbium), and is nonlinear optical. You may use the harmonic which wavelength-converted into the ultraviolet light using the crystal. The projection optical system may be any of the equal magnification and the magnification system as well as the reduction system.
Moreover, in each said embodiment, it is a matter of course that it is not limited to the light of wavelength 100nm or more as illumination light IL of an exposure apparatus, You may use the light of wavelength less than 100nm. For example, in order to expose a pattern of 70 nm or less, EUV (Extreme UltraViolet) light in a soft X-ray region (for example, a wavelength range of 5 to 15 nm) using a SOR or plasma laser as a light source. In addition, the EUV exposure apparatus using the total reflection reduction optical system designed under the exposure wavelength (for example, 13.5 nm), and a reflective mask is produced | generated. In this apparatus, there is a configuration in which the mask and the wafer are subjected to synchronous scanning and scan exposure using arc illumination.
In addition, the semiconductor device includes the steps of performing a function and performance design of the device, manufacturing a reticle based on the designing step, manufacturing a wafer from a silicon material, and forming a pattern formed on a mask in the exposure apparatus of each of the above embodiments. And a lithography step to transfer the resist (photosensitive agent) onto the coated wafer, a device assembly step (including a dicing step, a bonding step, a package step), an inspection step, and the like. In this case, since the exposure apparatus of each said embodiment is used in a lithography step, high precision exposure can be realized over a long term. Therefore, the productivity of the highly integrated microdevice in which a fine pattern was formed can be improved.
As explained above, the exposure apparatus, the exposure method, and the device manufacturing method of this invention are suitable for manufacturing electronic devices, such as a semiconductor element (integrated circuit) and a liquid crystal display element.
An exposure apparatus for exposing a substrate with exposure light through a projection optical system and a liquid,
A first stage on which the substrate is mounted;
A second stage movable independently of the first stage,
A detachable member having a flat surface on which a part of the light receiving surface on which the exposure light is incident is arranged, and detachably formed on the second stage;
A liquid immersion system for supplying a liquid directly below the projection optical system to form a liquid immersion region,
Directly below the projection optical system to transition from the first state in which the immersion region is maintained between the projection optical system and the first stage to a second state in which the immersion region is maintained between the projection optical system and the second stage. And the first and second stages are moved while maintaining the immersion area, and in the second state, the immersion area is held between the projection optical system and the flat surface.
The liquid immersion region moves on the flat surface formed on the detachable member while changing from the first state to the second state.
While changing from the first state to the second state, the first and second stages are brought together in the projection optical system in a state where the positional relationship in the first direction between the first stage and the second stage is approached. And a first drive device which moves in the first direction with respect to the.
A base member having a moving surface and on which the first stage and the second stage move;
A second driving device for moving the first stage in a second direction crossing the moving surface;
An exposure apparatus according to the second direction, further comprising a support device for supporting the weight of the first stage.
The second stage is formed around the mounted substrate and has a flat surface having the same height as the surface of the substrate.
The detachable member is mounted so as to be replaceable, and further includes a control device that detects when to replace the detachable member.
And a liquid supply device for supplying a liquid to form the immersion region, and for adjusting a flow rate of the liquid to be supplied.
At least one part of the said detachable member has liquid repellency, The exposure apparatus characterized by the above-mentioned.
A device manufacturing method having a lithography process,
A device manufacturing method is used for transferring a device pattern onto a substrate using the exposure apparatus according to claim 1.
As an exposure method which exposes a board | substrate with exposure light through a projection optical system and a liquid,
Supplying a liquid directly below the projection optical system to form a liquid immersion region, exposing a substrate mounted on a first stage via the projection optical system and the liquid;
From a first state in which the immersion region is maintained between the projection optical system and a second stage movable independently of the first stage, from a first state in which the immersion region is maintained between the projection optical system and the second stage. A flat surface which is movable independently of the first stage and the first stage, and which has a light receiving surface to which the exposure light is incident, while maintaining the liquid immersion region immediately below the projection optical system so as to transition. An exposure method comprising moving a second stage in which a detachable member having a detachable form is detachably formed.
Moving the liquid immersion region on the flat surface formed in the detachable member while changing from the first state to the second state.
While changing from the first state to the second state, the first and second stages are brought together to the projection optical system in a state where the positional relationship in the first direction of the first stage and the second stage is approached. And moving in the first direction relative to the first direction.
Moving the first stage and the second stage on a moving surface,
Moving the first stage in a second direction crossing the moving surface, and
An exposure method further comprising supporting the own weight of the first stage with respect to the second direction.
A substrate is mounted on the second stage, and the exposure method further comprises forming a flat surface having the same height as the surface of the substrate around the substrate mounted on the second stage.
And attaching the detachable member so as to be replaceable, and detecting the timing of replacing the detachable member.
Exposure method further comprising making at least one part of the said detachable member liquid-repellent.
A device manufacturing method for transferring a device pattern onto a substrate using the exposure method according to claim 10.
KR20067022068A 2004-03-25 2005-03-25 Exposure equipment, exposure method and device manufacturing method KR101181683B1 (en)
JPJP-P-2004-00088282 2004-03-25
KR20070019721A KR20070019721A (en) 2007-02-15
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