HK1158765A - Exposure method, exposure apparatus and maintenance method - Google Patents

Description

Exposure method, exposure apparatus, and maintenance method

The present application is a divisional application of an invention patent application having an application date of 2007, 5 and 22, application No. 200780005867.4, entitled "exposure method and apparatus, maintenance method, and device manufacturing method".

Technical Field

The present invention relates to an exposure technique for exposing a substrate with exposure light through a liquid, a maintenance technique for an exposure apparatus using the exposure technique, and a device manufacturing technique using the exposure technique.

Background

Microdevices (electronic devices) such as semiconductor devices and liquid crystal display devices are manufactured by a so-called photolithography method in which a pattern formed on a mask such as a reticle is transferred onto a substrate such as a wafer coated with a photosensitive material such as a resist. In the photolithography process, an exposure apparatus such as a step & repeat (step & repeat) reduction projection type exposure apparatus (so-called stepper) or a step & scan (step & scan) reduction projection type exposure apparatus (so-called scanning stepper) is used to transfer a pattern on a mask onto a substrate via a projection optical system.

In such an exposure apparatus, in order to cope with the demand for improved resolution (resolution) in the years accompanying the miniaturization of patterns due to high integration of semiconductor devices and the like, the reduction in the wavelength of exposure light and the increase in the Number of Apertures (NA) of a projection optical system (increase in NA) have been carried out. However, the reduction in the wavelength and the increase in the NA of the exposure light can improve the resolution of the projection optical system, but the depth of focus is reduced, and thus the depth of focus is too small, which may result in insufficient focusing during the exposure operation.

Therefore, as a method of substantially shortening the exposure wavelength and enlarging the depth of focus more than in the air, an exposure apparatus using a liquid immersion method has been developed (for example, see patent document 1). In this liquid immersion method, a space between the lower surface of the projection optical system and the substrate surface is filled with a liquid such as water or an organic solvent, and exposure is performed in a state where a liquid immersion region is formed. Accordingly, the wavelength of the exposure light in the liquid is 1/n times (n is a refractive index of the liquid, for example, about 1.2 to 1.6) that of the exposure light in the air, thereby improving the resolution and extending the focal depth to about n times.

[ patent document 1] International publication No. 99/49504 pamphlet

In the exposure process using the liquid immersion method, exposure is performed while supplying a liquid from a predetermined liquid supply mechanism to a liquid immersion area between the projection optical system and the substrate, and the liquid in the liquid immersion area is recovered by a predetermined liquid recovery mechanism. However, in exposure using this liquid immersion method, there is a possibility that fine foreign matter (particles) such as resist residue may adhere to a portion in contact with the liquid, for example, a portion in contact with the liquid such as liquid flow paths of the liquid supply mechanism and the liquid recovery mechanism. Such foreign matter adhering to the substrate may be mixed into the liquid again at the time of exposure and adhere to the substrate to be exposed, which may cause defects such as a defective shape of the transfer pattern.

Therefore, it is desirable to periodically determine whether or not there is a possibility that foreign matter may adhere to at least a part of a portion where the liquid comes into contact, the foreign matter causing a shape failure or the like, which hardly causes a reduction in productivity in the exposure step (an operation rate of the exposure apparatus).

Recently, various resists have been developed to improve resolution, sensitivity, and the like. In addition, a surface coating for antireflection and/or resist protection may be applied to the resist, and new materials for such a surface coating and the like have been newly developed. However, some of these materials do not cause problems in dry exposure, but may cause shape errors in the resist pattern stage in exposure by the liquid immersion method. In this way, when the material is found to be unsuitable for use in the liquid immersion method after actually passing through the exposure step and the development step, the exposure step and the like become ineffective, and the efficiency of device production is reduced.

In addition, when exposure is performed by a liquid immersion method in the case where there is an abnormality (for example, uneven film thickness) in a resist, a surface coating film, or the like, peeling or the like is likely to occur due to contact with a liquid, and there is a possibility that a shape error or the like occurs at a resist pattern stage. Therefore, when the liquid immersion exposure is performed even in the case where the film state is abnormal, the exposure process and the subsequent processes may be ineffective.

Disclosure of Invention

In view of the above circumstances, it is a first object of the present invention to provide an exposure technique, a maintenance technique, and a device manufacturing technique that can effectively determine whether or not there is an abnormality in a portion in contact with an exposure apparatus that performs exposure by a liquid immersion method, that is, whether or not there is a possibility of foreign matter adhering thereto, which may cause, for example, a shape defect of a pattern to be transferred. The present invention has a2 nd object to provide an exposure technique and a device manufacturing method capable of determining whether or not a state of a substrate to be exposed is suitable for exposure by a liquid immersion method without actually performing exposure.

The invention according to claim 1 is an exposure method for exposing a substrate (P) with Exposure Light (EL) through an optical member (2) and a liquid (1), comprising: a1 st step (S1, S2) of optically observing the state of detected parts (68A-68D) of at least a part of a liquid contact part which is in contact with the liquid during a predetermined operation, and storing the obtained 1 st observation information; a2 nd step (S4, S5) of optically observing the state of the detected part after the predetermined operation to obtain 2 nd observation information; and a3 rd step (S6, S7) of comparing the 1 st observation information with the 2 nd observation information to determine whether the detected part is abnormal or not.

According to claim 1 of the present invention, by comparing only the 1 st observation information in the state where the foreign matter is not attached before exposure with the 2 nd observation information after exposure, it is possible to efficiently determine whether or not the foreign matter exceeding a predetermined allowable range is attached to the portion to be inspected (lyophobic portion), for example, and further determine whether or not there is an abnormality. The exposure method according to claim 1 of the present invention may further include a step 4 of stopping the exposure operation when the abnormality is found in the step 3. This can reduce the possibility of foreign matter being mixed into the liquid at the time of exposure by the subsequent liquid immersion method.

The invention according to claim 2 is an exposure method for exposing a substrate (P) with Exposure Light (EL) through an optical member (2) and a liquid (1), comprising: detecting information relating to the state of the liquid contact portions (68A-68D, 25) with which the liquid is in contact during a predetermined operation; and detecting information relating to an abnormality of the liquid contact portion based on the detection information and reference information relating to a state of the liquid contact portion before the predetermined operation.

The invention according to claim 3 is an exposure apparatus for exposing a substrate (P) with Exposure Light (EL) through an optical member (2) and a liquid (1), comprising: an optical device (ALG, 65) for optically observing the state of the detection target sections (68A-68D, 25) of at least a part of the liquid contact section that is in contact with the liquid; a memory device (58) for storing the observation information of the optical device; and a control device (57, CONT) for comparing observation information obtained by observing the detected portion a plurality of times by the optical device (ALG, 65) to determine whether the detected portion is abnormal or not.

The invention according to claim 4 is an exposure apparatus for exposing a substrate (P) with Exposure Light (EL) through an optical member (2) and a liquid (1), comprising: an optical device (ALG, 65) that detects information relating to the state of liquid contact portions (68A-68D, 25) that are in contact with the liquid during a predetermined operation; and a control device (57) that detects information relating to an abnormality in the liquid contact portion, based on the detection information and reference information relating to the state of the liquid contact portion before the predetermined operation.

The invention according to claim 5 is a maintenance method for maintaining an exposure apparatus that exposes a substrate (P) via an optical member (2) and a liquid (1), comprising: detecting information relating to the state of liquid contact portions (68A-68D, 25) that are in contact with the liquid during a predetermined operation; and detecting information relating to an abnormality of the liquid contact portion based on the detection information and reference information relating to a state of the liquid contact portion before the predetermined operation.

The invention according to claim 6 is an exposure method for exposing a substrate (P) with Exposure Light (EL) through a liquid (1), comprising: step 1 (part of step 2103) of supplying the liquid to only a partial region on the substrate; a2 nd step (a part of step 2103) of recovering at least a part of the liquid supplied in the 1 st step and detecting a state of the recovered liquid; a step 3 (step 2105) of inspecting a film state of the substrate; and a4 th step (steps 2104, 2106) of determining whether or not there is an abnormality in the substrate based on a result of detection in at least one of the 2 nd step and the 3 rd step

According to claim 6 of the present invention, it is possible to easily determine the state of the substrate to be exposed and whether or not the film state of the substrate is suitable for the exposure by the liquid immersion method without actually performing the exposure.

The invention according to claim 7 is an exposure method for exposing a substrate (P) with Exposure Light (EL) through an optical member (2) and a liquid (1), comprising: filling a space between the optical member and an object with a liquid to form a liquid immersion space, and recovering the liquid in the liquid immersion space; detecting information relating to said recovered liquid; and detecting information relating to an abnormality of the liquid contact portion with which the liquid is in contact, based on the detection information.

An exposure apparatus (EX') according to claim 8, which exposes a substrate (P) with Exposure Light (EL) through a liquid (1), includes: a liquid supply system (212 ) for supplying the liquid (1) to only a partial region on the substrate (P); a1 st detector (226) for recovering the liquid supplied by the liquid supply system and detecting a state of the recovered liquid; a2 nd detector (ALG) for detecting a state of the film of the substrate; and a control device (CONT) for determining whether or not there is an abnormality in the substrate based on the detection result of at least one of the 1 st detector and the 2 nd detector.

An exposure apparatus according to claim 9 of the present invention exposes a substrate (P) with Exposure Light (EL) through an optical member (2) and a liquid (1), and includes: a liquid immersion mechanism (10, 20) that fills a space between the optical member and the object with a liquid to form a liquid immersion space, and collects the liquid in the liquid immersion space; a detection device (226) for detecting information relating to the recovered liquid; and a control device (CONT) for detecting information relating to an abnormality in a liquid contact portion that is in contact with the liquid, based on the detection information.

The invention according to claim 10 is a method for manufacturing a component, comprising: exposing (204) the substrate using the exposure method or the exposure apparatus (EX, EX'); developing (204) the exposed substrate; and processing the developed substrate (205).

The numerals in parentheses after the respective prescribed requirements of the present invention correspond to the members in the drawings showing the embodiments of the present invention, but the respective numerals show the requirements of the present invention only for easy understanding of the present invention, and the present invention is not limited to the configurations of the embodiments.

Drawings

Fig. 1 is a partially broken schematic configuration diagram of an example of an exposure apparatus according to an embodiment of the present invention.

Fig. 2 is a perspective view showing the nozzle member 30 in fig. 1.

Fig. 3 is a perspective view of the nozzle member in bottom view 2.

Fig. 4 is a diagram showing an example of the configuration of the alignment sensor ALG in fig. 1.

Fig. 5 is a plan view showing the substrate stage PST and the measurement stage MST in fig. 1.

Fig. 6 is a cross-sectional view showing a state in which measurement table MTB in measurement stage MST in fig. 1 is moved to a position below projection optical system PL.

Fig. 7 is a plan view showing an example of a relative movement path between the substrate holder PH, the projection optical system PL, and the alignment sensor ALG on the substrate stage PST in fig. 1.

Fig. 8 is a flowchart showing an example of the sequence of the exposure method according to embodiment 1 of the present invention.

Fig. 9 is a schematic configuration diagram showing an example of an exposure apparatus according to embodiment 2 of the present invention.

Fig. 10 is a perspective view showing the nozzle member shown in fig. 9.

Fig. 11 is a plan view showing the arrangement of the supply port and the recovery port for the liquid formed in the 1 st member shown in fig. 10.

Fig. 12 is a sectional view taken along line XII-XII of fig. 10.

Fig. 13 is a plan view showing the substrate stage shown in fig. 9 and a substrate thereon.

Fig. 14 is a plan view showing an area through which a liquid immersion area on a substrate passes.

Fig. 15 is a flowchart showing an example of the procedure for determining whether or not the substrate film is good according to embodiment 2 of the present invention.

Fig. 16 is a flowchart showing an example of the process of the micro component.

Reference numerals

1: a liquid; 2: an optical element; 10: a liquid supply mechanism; 11: a liquid supply section; 13. 14: a supply port; 20: a liquid recovery mechanism; 21: a liquid recovery unit; 24: a recovery port; 25: a mesh filter; 26: a cleaning solution supply section; 29A to 29D: a recovery port; 30: a nozzle member; 31. 32: the 1 st member and the 2 nd member of the nozzle member; 65: a nozzle observation device; 68A to 68G: an observation target portion; ALG: an alignment sensor; AR 2: a liquid immersion area; CONT: a control device; EL: exposure light; m: masking; MTB: a measuring table; MST: a measuring platform deck; p: a substrate; PL: a projection optical system.

Detailed Description

EXAMPLE 1 embodiment

Hereinafter, an example of the best 1 st embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a schematic configuration diagram showing an exposure apparatus EX constituted by a scanning type exposure apparatus (so-called scanning stepper) of the present example, and in fig. 1, the exposure apparatus EX includes: a mask stage RST for supporting a mask M on which a transfer pattern is to be formed, a substrate stage PST for supporting a substrate P to be exposed, an illumination optical system IL for illuminating the mask M supported by the mask stage RST with exposure light EL, a projection optical system PL for projecting a pattern image of the mask M illuminated with the exposure light EL onto a projection area AR1 on the substrate P supported by the substrate stage PST, a measurement stage MST on which alignment reference marks and the like are formed, a control device CONT for controlling overall operations of the exposure device EX, a liquid immersion system (liquid immersion mechanism) for applying a liquid immersion method, and an off-axis alignment sensor ALG for aligning the substrate P, for example, an image processing method. The liquid immersion system of the present embodiment includes: a liquid supply mechanism 10 for supplying the liquid 1 onto the substrate P and the measurement stage MST, and a liquid recovery mechanism 20 for recovering the liquid 1 supplied onto the substrate P and the measurement stage MST.

The exposure apparatus EX forms the liquid immersion area AR2 in a partial area on the substrate P (the projection area AR1 including the projection optical system PL) or in a partial area on the substrate P and its surrounding area (local) by the liquid 1 supplied by the liquid supply mechanism 10 at least while the pattern image of the mask M is transferred onto the substrate P. More specifically, the exposure apparatus EX employs a local immersion method in which a liquid 1 is filled between an optical element (for example, a lens having a substantially flat bottom surface, a parallel plate, or the like) 2 at the end of the projection optical system PL on the image plane side and the surface of the substrate P disposed on the image plane side, and exposes the substrate P with the exposure light EL passing through the mask M through the projection optical system PL and the liquid 1 between the projection optical system PL and the substrate P, thereby transferring and exposing the pattern of the mask M to the substrate P. In this example, the liquid immersion exposure is performed using a liquid immersion space forming member that forms a liquid immersion space including an optical path space of the exposure light EL emitted from the projection optical system PL.

Hereinafter, a description will be given taking a direction parallel to the optical axis AX of the projection optical system PL as a Z-axis, taking a direction of synchronous movement (scanning direction) of the mask M and the substrate P in a plane perpendicular to the Z-axis as an X-axis, and taking a direction (non-scanning direction) perpendicular to the scanning direction as a Y-axis. Directions around the X, Y, and Z axes (tilt) are referred to as θ X, θ Y, and θ Z directions, respectively. The substrate herein includes, for example, a substrate coated with a photosensitive material (hereinafter, referred to as a resist as appropriate) on a base material of a semiconductor wafer or the like such as a silicon wafer, and the so-called photosensitive film includes various films coated with other protective films (topcoat films). The mask includes a reticle for forming a device pattern to be reduced in size on a substrate, and a predetermined pattern is formed on a transparent plate member such as a glass plate using a light-shielding film such as chromium. The transmission mask is not limited to a binary mask in which a pattern is formed by a light-shielding film, and includes, for example, a phase shift mask of a half-tone type, a spatial frequency modulation type, or the like. In this embodiment, a resist of a photosensitive material having a predetermined thickness (for example, about 20 nm) is applied to a disc-shaped semiconductor wafer having a diameter of, for example, about 200mm to 300mm by, for example, an unillustrated coating and developing apparatus, and an antireflection film or a top coat film is applied thereon as necessary.

First, illumination optical system IL illuminates mask M supported by mask stage RST with exposure light EL, and includes: an optical integrator for uniformizing the illuminance of a light beam emitted from an exposure light source, not shown, a condenser lens for condensing the exposure light EL from the optical integrator, a relay lens system, a variable field stop for setting an illumination region on the mask M by the exposure light EL in a slit shape, and the like. The predetermined illumination area on the mask M is illuminated with exposure light EL having a uniform illumination distribution by an illumination optical system IL. The exposure light EL emitted from the illumination optical system IL is, for example, a bright line (i line, etc.) in the ultraviolet band emitted from a mercury lamp, a deep ultraviolet light (DUV light) such as a KrF excimer laser (wavelength 248nm), or an ArF excimer laser (wavelength 193nm), F₂Vacuum ultraviolet light (VUV light) such as laser light (wavelength 157 nm). In this example, ArF excimer laser light was used as the exposure light EL.

Further, mask stage RST supports mask M and is movable in 2 dimensions and slightly rotatable in the θ Z direction in a plane perpendicular to optical axis AX of projection optical system PL, i.e., an XY plane, on a mask holder, not shown. Mask stage RST is driven by mask stage driving device RSTD such as a linear motor. The mask stage driving device RSTD is controlled by the control device CONT. A mirror 55A is provided on mask stage RST, and a laser interferometer 56A is provided at a position opposite to mirror 55A. In practice, the laser interferometer 56A is configured as a laser interferometer system having a longitudinal axis of 3 or more axes. The 2-dimensional directional position and the rotation angle of the mask stage RST (mask M) are measured in real time by the laser interferometer 56A, and the measurement results are output to the control device CONT. The control device CONT drives the mask stage driving device RSTD based on the measurement result, thereby moving and positioning the mask M supported by the mask stage RST. Further, mirror 55A may include not only a plane mirror but also a corner cube (retro-reflector), or may use, instead of mirror 55A, for example, a reflecting surface formed by applying a mirror surface process to an end surface (side surface) of mask stage RST.

The projection optical system PL is used for projection exposure of the pattern of the mask M onto the substrate P at a predetermined projection magnification β (β is a reduction magnification such as 1/4 or 1/5), and is composed of a plurality of optical elements including an optical element 2 provided at an end portion on the substrate P side (image plane side of the projection optical system PL), and these optical elements are supported by a barrel PK. The projection optical system PL is not limited to the reduction system, and may be any of an equal magnification system and an enlargement system. Further, the optical element 2 at the tip of the projection optical system PL is detachably (replaceably) provided in the lens barrel PK, and the liquid 1 in the liquid immersion area AR2 contacts the optical element 2. Although not shown, the projection optical system PL is mounted on a lens barrel stage supported by 3 supports via a vibration-proof mechanism, the projection optical system PL may be suspended and supported on a main frame member, not shown, disposed above the projection optical system PL, the mask base, or the like, as disclosed in wo 2006/038952 pamphlet.

In this example, pure water was used as the liquid 1. Pure water not only allows ArF excimer laser to pass through, but also can be used as bright line of ultraviolet band emitted from mercury lamp or far ultraviolet (DUV light) of KrF excimer laserCan penetrate through. Fluorite (CaF) for optical element 2₂) And (4) forming. Since fluorite has high affinity with water, the liquid contact surface 2a of the optical element 2 can be brought into substantially complete contact with the liquid 1. The optical element 2 may be quartz or the like having high affinity for water.

The resist of the substrate P is, for example, a resist having liquid repellency to repel the liquid 1. As described above, a protective topcoat layer may be applied to the resist as needed. In this example, the property of repelling the liquid 1 is referred to as lyophobicity. When the liquid 1 is pure water, the lyophobicity means hydrophobicity. A substrate holder PH for holding the substrate P by vacuum suction, for example, is fixed to the upper portion of the substrate stage PST. Further, substrate stage PST includes: a Z stage 52 that controls a Z-direction position (focus position) of the substrate holder PH (substrate P) and tilt angles in the θ X and θ Y directions, and an XY stage 53 that supports and moves the Z stage 52, the XY stage 53 being, for example, mounted on a guide surface parallel to the XY plane (a surface substantially parallel to the image plane of the projection optical system PL) on a base 54 via an air bearing. The substrate stage PST (the Z stage 52 and the XY stage 53) is driven by a substrate stage driving device PSTD such as a linear motor. The substrate stage driving device PSTD is controlled by the control device CONT. In this example, the substrate holder is formed on a table (table) movable in the Z, θ X, and θ Y directions, and is collectively referred to as a substrate holder PH. The stage and the substrate holder may be separately configured, and the substrate holder may be fixed to the stage by, for example, vacuum suction. Further, Z stage 52 may be configured by, for example, a substrate holder PH (stage) and an actuator (e.g., a voice coil motor) that drives substrate holder PH (stage) in the Z, θ X, and θ Y directions.

A mirror 55B is provided on the substrate holder PH on the substrate stage PST, and a laser interferometer 56B is provided at a position opposite to the mirror 55B. The mirror 55B is actually composed of an X-axis mirror 55BX and a Y-axis mirror 55BY, as shown in fig. 5, and the laser interferometer 56B is composed of an X-axis laser interferometer 56BX and a Y-axis laser interferometer 56 BY. Referring back to fig. 1, the 2-dimensional directional position and the rotation angle of the substrate holder PH (substrate P) on the substrate stage PST are measured in real time by the laser interferometer 56B, and the measurement results are output to the control unit CONT. The control device CONT drives the substrate stage driving device PSTD based on the measurement result, thereby moving and positioning the substrate P supported by the substrate stage PST. The laser interferometer 56B may be designed to measure the Z-axis position of the substrate stage PST and the rotation information in the θ X and θ Y directions, and details thereof are disclosed in, for example, japanese patent application laid-open No. 2001-510577 (corresponding to the pamphlet of international publication No. 1999/28790). Instead of the mirror 55B, a mirror formed by mirror-finishing the side surface of the substrate stage PST or the substrate holder PH may be used.

Further, a replaceable ring-shaped, flat, liquid-repellent plate 97 is provided on the substrate holder PH so as to surround the substrate P. The lyophobic treatment may be a single-layer or multi-layer film coating treatment using a lyophobic material. Examples of the material having liquid repellency include a fluorine-based resin material such as tetrafluoroethylene (teflon (registered trademark)), an acrylic-based resin material, a silicone-based resin material, and a synthetic resin material such as polyethylene. A flat surface on the plate member 97 is substantially at the same level as the surface of the substrate P held by the substrate holder PH. Here, although there is a gap of 0.1 to 1mm between the edge of the substrate P and the plate member 97, in this example, since the resist of the substrate is lyophobic and the liquid 1 has surface tension, the liquid 1 hardly flows into the gap, and even if exposure is performed near the edge of the substrate P, the liquid 1 can be held between the plate member 97 and the projection optical system PL. Further, a suction device (not shown) for discharging the liquid 1 flowing into the gap between the plate 97 and the substrate P to the outside may be provided in the substrate holder PH. Therefore, the resist (or topcoat) of the substrate P does not necessarily have to have lyophobicity. In this example, the plate member 97 is provided on the substrate holder PH, but a liquid repellent treatment may be applied to the upper surface of the substrate holder PH surrounding the substrate P to form a flat surface.

[ description of the mechanism for supplying and recovering liquid ]

Next, the liquid supply mechanism 10 of fig. 1 supplies a predetermined liquid 1 onto the substrate P, and includes: a liquid supply part 11 capable of sending out the liquid 1, and a supply pipe 12 having one end connected to the liquid supply part 11. The liquid supply unit 11 includes: a reservoir for storing the liquid 1, a filter unit, and a pressure pump. The liquid supply device 11 need not include all of a liquid tank, a filter unit, a pressure pump, and the like, and at least a part thereof may be replaced with equipment such as a factory in which the exposure apparatus EX is installed.

The liquid recovery mechanism 20 recovers the liquid 1 supplied onto the substrate P, and includes: a liquid recovery unit 21 capable of recovering the liquid 1, a recovery pipe 22 having one end connected to the liquid recovery unit 21, a supply pipe 27 connected to the recovery pipe 22, and a cleaning liquid supply unit 26 connected to the end of the supply pipe 27 and supplying a predetermined cleaning liquid. Valves 23 and 28 are provided on the recovery pipe 22 and the supply pipe 27, respectively. The liquid recovery unit 21 includes, for example, a vacuum system (suction device) such as a vacuum pump, a reservoir for storing the recovered liquid 1, and the like. The cleaning liquid supply unit 26 includes a reservoir for storing the cleaning liquid, a pressure pump, and the like. By closing the valve 23 on the recovery pipe 22 side and opening the valve 28 on the supply pipe 27 side, the cleaning liquid can be supplied from the cleaning liquid supply unit 26 to the recovery pipe 22 through the recovery pipe 27. The liquid recovery mechanism 20 does not need to have a vacuum system, a liquid storage tank, or the like, and at least a part thereof may be replaced with equipment such as a factory in which the exposure apparatus EX is installed.

As the cleaning liquid, a mixed liquid of water and a diluent, or a solvent such as γ -butyl propyl ester (γ -butyl lactone) or isopropyl alcohol (IPA) other than the liquid 1 can be used. However, the cleaning liquid 1 may be used. Further, the supply pipe 27 from the cleaning liquid supply portion 26 may be connected to the supply pipe 12 communicating with the liquid supply portion 11. In this case, the cleaning liquid can be supplied to the liquid immersion area (liquid immersion space) separately and independently from the supply flow path (for example, supply pipe 12) of the liquid 1. Further, for example, when the liquid 1 supplied from the liquid supply portion 11 is used as the cleaning liquid, the cleaning liquid supply portion 26 and the supply pipe 27 are not necessarily provided.

A nozzle member 30 as a flow path forming member is disposed near the optical element 2 at the end of the projection optical system PL. The nozzle member 30 is an annular member provided above the substrate P (substrate stage PST) around the optical element 2, and is supported by a column mechanism (not shown) via a support member (not shown). In a state where the projection area AR1 of the projection optical system PL is positioned on the substrate P, the nozzle member 30 includes the 1 st supply port 13 and the 2 nd supply port 14 (see fig. 3) which are arranged so as to face the surface of the substrate P. The nozzle member 30 has supply flow paths 82A and 82B (see fig. 3) therein. One end of the supply channel 82A is connected to the 1 st supply port 13, the middle of the supply channel 82A is connected to the 2 nd supply port 14 (see fig. 3) via the supply channel 82B, and the other end of the supply channel 82A is connected to the liquid supply unit 11 via the supply tube 12. The nozzle member 30 includes a rectangular frame-shaped recovery port 24 (see fig. 3) disposed so as to face the front surface of the substrate P.

Fig. 2 is a schematic perspective view of the nozzle member 30. As shown in fig. 2, the nozzle member 30 is an annular member provided around the optical element 2 at the end of the projection optical system PL, and includes, for example, a1 st member 31 and a2 nd member 32 disposed above the 1 st member 31. The 1 st and 2 nd members 31 and 32 are plate-like members, respectively, and have through holes 31A and 32A in the center thereof, in which the projection optical system PL (optical element 2) can be disposed.

Fig. 3 is a perspective view of the 1 st member 31 of the lower layer of the nozzle member 30 of fig. 2 as viewed from the bottom (lower surface). In fig. 3, the supply flow paths 82A, 82B of the 2 nd member 32 formed thereon and the supply pipe 12 connected to the supply flow path 82A are indicated by two-dot chain lines. The 1 st member 31 of the nozzle member 30 includes: a1 st supply port 13 formed on the + X direction side of the optical element 2 of the projection optical system PL for supplying the liquid 1 onto the substrate P, and a2 nd supply port 14 formed on the-X direction side of the optical element 2 for supplying the liquid 1 onto the substrate P. The supply ports 13 and 14 are arranged so as to sandwich the projection area AR1 in the X direction (the scanning direction of the substrate P). The supply ports 13 and 14 are through holes penetrating the 1 st member 31, and are elongated in the Y direction and rectangular, but may be circular arc-shaped or the like extending outward from the center of the projection area AR 1.

In addition, the 1 st member 31 is formed with: a rectangular (or circular or the like) frame-shaped recovery port 24 disposed so as to surround the optical element 2 (projection area AR1) of the projection optical system PL, and a recovery flow path 84 for communicating the recovery port 24 and the recovery tube 22. The recovery port 24 is formed in a groove-like recess in the bottom surface of the 1 st member 31 and is provided outside the supply ports 13 and 14 with respect to the optical element 2. The gaps between the supply ports 13 and 14 and the substrate P and the gaps between the recovery port 24 and the substrate P are substantially the same, for example. Further, a mesh filter 25 (a porous member having a plurality of small holes formed in a mesh shape) covering the recovery port 24 is inserted. The liquid immersion area AR2 filled with the liquid 1 is formed inside a rectangular (circular or the like) area surrounded by the recovery port 24 so as to cover the projection area AR1, and is partially formed on (or includes) a part of the substrate P during scanning exposure.

The 1 st member 31, the 2 nd member 32 of the nozzle member 30 of fig. 2, and the mesh filter 25 of fig. 3 are each formed of a lyophilic material that readily affinites with the liquid 1, such as stainless steel (SUS) or titanium. Therefore, in fig. 1, the liquid 1 in the liquid immersion area AR2 is smoothly collected into the liquid collection unit 21 through the collection flow path 84 and the collection pipe 22 after passing through the mesh filter 25 provided in the collection port 24 of the nozzle member 30. At this time, among foreign substances such as resist residues, foreign substances larger than the meshes of the mesh filter 25 remain on the surface thereof.

In fig. 3, the liquid recovery port 24 of the present example is rectangular or circular frame-shaped, but as shown by the two-dot chain line, a recovery port composed of 2 rectangular (or arc-shaped or the like) recovery ports 29A and 29B provided so as to sandwich the supply ports 13 and 14 in the X direction and 2 rectangular (or arc-shaped or the like) recovery ports 29C and 29D provided so as to sandwich the optical element 2 in the Y direction may be used, and a mesh filter is disposed in each of the recovery ports 29A to 29D. The number of recovery ports 29A to 29D may be arbitrary. Further, as disclosed in, for example, pamphlet of international publication No. 2005/122218, the liquid 1 in the liquid immersion area AR2 may be recovered by using the recovery ports 29A to 29D and the recovery port 24 in double. Further, a filter-like member for preventing foreign matter in the liquid immersion area AR2 from entering the nozzle member 30 may be disposed at the supply ports 13 and 14. Conversely, for example, when the possibility of foreign matter adhering to the recovery pipe 22 is low, it is not always necessary to provide a mesh filter.

The nozzle member 30 used in the above embodiment is not limited to the above structure, and for example, the flow path forming members described in european patent application publication No. 1420298, international publication No. 2004/055803 pamphlet, international publication No. 2004/057589 pamphlet, international publication No. 2004/057590 pamphlet, international publication No. 2005/029559 pamphlet (corresponding to U.S. patent application publication No. 2006/0231206), and the like can be used.

In this example, the supply ports 13 and 14 and the recovery port 24 for the liquid are provided in the same nozzle member 30, but the supply ports 13 and 14 and the recovery port 24 may be provided in different members. In fig. 1, the supply ports 13 and 14 may be connected to different liquid supply portions, respectively, and the liquid 1 may be supplied from the supply ports 13 and 14 to the liquid immersion area AR2 in a state in which the control amounts are independently controllable. The supply ports 13 and 14 may not be disposed opposite to the substrate P. Further, the lower surface of the nozzle member 30 is set closer to the image plane side (substrate side) than the lower end surface (emission surface) of the projection optical system PL, but the lower surface of the nozzle member 30 may be set to the same height (Z position) as the lower end surface of the projection optical system PL, for example. Further, a part (lower end) of the nozzle member 30 may be recessed below the projection optical system PL (optical element 2) so as not to shield the exposure light EL.

As described above, the nozzle member 30 of fig. 1 constitutes a part of the liquid supply mechanism 10 and a part of the liquid recovery mechanism 20, respectively. That is, the nozzle member 30 is a part of the liquid immersion mechanism of this example. The valves 23 and 28 provided in the recovery pipe 22 and the supply pipe 27 open and close the flow paths of the recovery pipe 22 and the supply pipe 27, respectively, and the operation thereof is controlled by the control device CONT. While the flow path of the recovery tube 22 is open, the liquid recovery unit 21 can suction and recover the liquid 1 from the immersion area AR2 through the recovery port 22, and when the flow path of the recovery tube 22 is closed by the valve 23 with the valve 28 in the closed state, the suction and recovery of the liquid 1 through the recovery port 24 is stopped. Thereafter, by opening the valve 28, the cleaning liquid can be flowed from the cleaning liquid supply unit 26 through the supply pipe 27, the recovery pipe 22, and the mesh filter 25, and through the recovery port 24 of the nozzle member 30. Further, a part of the liquid immersion mechanism, for example, at least the nozzle member 30 may be suspended and supported by a main frame (including the lens barrel stage, for example) that holds the projection optical system PL, or another frame member different from the main frame. Alternatively, when the projection optical system PL is supported in a suspended manner as described above, the nozzle member 30 may be suspended and supported integrally with the projection optical system PL, or the nozzle member 30 may be provided separately and independently from the projection optical system PL on the measurement frame, and in the latter case, the projection optical system PL may not be supported in a suspended manner.

In fig. 1, the liquid supply of the liquid supply portion 11 and the cleaning liquid supply portion 26 is controlled by the control device CONT. The controller CONT can independently control the amounts of the liquid supplied to the substrate P per unit time by the liquid supply unit 11 and the cleaning liquid supply unit 26. The liquid 1 sent from the liquid supply unit 11 is supplied onto the substrate P from the supply ports 13 and 14 (see fig. 3) provided on the lower surface of the nozzle member 30 (the 1 st member 31) so as to face the substrate P via the supply pipe 12 and the supply flow paths 82A and 82B of the nozzle member 30.

The liquid recovery operation of the liquid recovery unit 21 is controlled by the control unit CONT. The control unit CONT can control the amount of liquid recovered by the liquid recovery unit 21 per unit time. The liquid 1 on the substrate P collected from the recovery port 24 provided opposite to the substrate P from the lower surface of the nozzle member 30 (the 1 st member 31) via the mesh filter 25 is recovered to the liquid recovery unit 21 through the recovery flow path 84 of the nozzle member 30 and the recovery pipe 22.

[ description of alignment sensor ALG ]

Next, the configuration of the alignment sensor ALG according to the image processing method of this embodiment will be described with reference to fig. 4. The alignment sensor ALG is an off-axis fia (field Image alignment) system, and includes a light source (e.g., a halogen lamp) 141 for supplying illumination light having a wide wavelength band (e.g., about 400 to 800 nm) outside a sealed housing 140 for housing an optical system. Illumination light supplied from the light source 141 is guided into the housing 140 through a condensing optical system (not shown) and a light guide 142 made of an optical fiber, and illumination light ILA of a substantially visible light band emitted from an emission end of the light guide 142 is incident on a dichroic mirror 144 that reflects visible light and transmits infrared light through a condensing lens 143. The illumination light ILA reflected by the dichroic mirror 144 passes through the illumination field stop 145 and the lens system 146, and enters the prism 147.

The prism 147 has a property of transmitting all the light beams incident upward and reflecting all the light beams incident downward, and the illumination light ILA is transmitted through the prism 147 and then incident on the infrared light reflecting plate 149 through the lens system 148. The infrared light reflecting plate 149 has a pointer mark IM formed on the surface thereof, has a characteristic of reflecting infrared light on the back surface thereof and transmitting visible light, and has a light transmissive substrate on which an infrared light reflecting film is formed. The illumination light ILA passing through the infrared reflector 149 illuminates the alignment mark AM (or a reference mark or the like) formed on the substrate P through the objective lens 150.

The reflected light (including diffracted light, also referred to as ILA) from the alignment mark AM (or reference mark) by the irradiation of the illumination light ILA passes through the objective lens 150, the infrared light reflecting plate 149, and the lens system 148, is totally reflected by the prism 147, and then enters the dichroic mirror 152, which transmits visible light and reflects infrared light, through the lens system 151. The reflected light ILA transmitted through the dichroic mirror 152 enters the XY-splitting half prism 154 through a condenser lens, not shown, and the light reflected by the half prism 154 forms a mark image on the CCD155 as an X-direction image pickup device, while the light transmitted through the half prism 154 forms a mark image on the CCD156 as a Y-direction image pickup device.

The alignment sensor ALG includes a light source for illuminating the pointer mark IM and an LED (light emitting diode) 157 that emits illumination light having a wavelength of 870nm, for example. The infrared band illumination light ILB emitted from the LED157 illuminates the infrared reflector 149 via the condenser lens 158, the dichroic mirror 144, the illumination field stop 145, the lens system 146, the prism 147, and the lens system 148. The illumination light ILB reflected by the infrared light reflecting surface of the infrared light reflecting plate 149 illuminates the pointer mark IM formed on the infrared light reflecting plate 149. The illumination light ILB illuminating the pointer mark IM passes through the lens system 148, the prism 147, and the lens system 151, and is reflected by the dichroic mirror 152 to form an image of the pointer mark IM on the CCD153 of the pointer mark image pickup device.

The CCDs 155 and 156 for the X direction and the Y direction respectively include a plurality of pixels arranged in 2 dimensions in an elongated region corresponding to the X direction and the Y direction on the substrate stage PST in fig. 1, and are used for position detection of the X-axis and the Y-axis alignment marks (or reference marks). The pointer mark CCD153 includes a plurality of pixels arranged in, for example, 2-dimensional in a frame-shaped region corresponding to the pointer mark IM, and is used for detecting the position of the pointer mark serving as an X-direction and Y-direction position reference when detecting the position of the alignment mark or the reference mark. The image pickup signals of the CCDs 155, 156, and 153 are supplied to the data processing device 57, and when detecting the mark, the data processing device 57 detects the amount of displacement of the detected mark in the X direction and the Y direction from the supplied image pickup signal with respect to the pointer mark IM, and sends the detection result to the alignment control unit in the control device CONT of fig. 1.

As described above, the alignment sensor ALG is used for detecting the position of the detection target mark, and in the present example, as described later, image data of the image of the detection target portion captured by the alignment sensor ALG is used for determining whether or not at least a part (observation target portion) of the liquid contact portion of the portion that is likely to contact the liquid 1 is abnormal when the exposure is performed by the liquid immersion method among the members constituting the exposure apparatus EX. That is, the alignment sensor ALG is also used as a means for optically observing the state of the observation target portion. As an image pickup device for this purpose, any of the CCDs 155 and 156 for the X direction and the Y direction can be used. The resolution at the time of abnormality determination of the alignment sensor ALG (here, the size of the object surface corresponding to 1 pixel of the CCD155 (or 156)) may be, for example, about 10 μm, and the resolution at the time of alignment is far finer than this, and therefore there is no problem.

At this time, the image data captured for the abnormality determination is stored in the image memory 58, which is connected to the data processing device 57 and is constituted by a magnetic disk device or the like. Further, since the field of view of the alignment sensor ALG is in the-Z direction, the liquid contact portions for abnormality determination by the alignment sensor ALG are the upper surface of the plate member 97 on the substrate holder PH (substrate stage PST), the area between the plate member 97 and the substrate P, the upper surface of the substrate P, and the upper surface of the measurement stage MST (the upper surface of the plate member 101 described later). In addition, when a part of the suction means for sucking the liquid flowing into the groove between the plate 97 and the substrate P is provided in the substrate holder PH, the inside of the groove (the part where the suction port is formed) may be a liquid contact part, and foreign matter may be easily left in the inside. Therefore, for example, as shown in fig. 7, a region including a plurality of regions (for example, 4 regions) arranged at equal angular intervals in the region between the plate member 97 and the substrate P can be used as the observation target portions 68A, 68B, 68C, and 68D of the alignment sensor ALG.

In this example, as shown in fig. 1, an alignment sensor (mask alignment system) 90 of an image processing system (e.g., a so-called reticle alignment microscope) for detecting the positions of alignment marks on mask M and corresponding predetermined reference marks on measurement stage MST is arranged above mask stage RST. The alignment sensor 90 can observe an object (foreign matter or the like) image on the image plane of the projection optical system PL via the projection optical system PL. Therefore, the alignment sensor 90 on the mask side can be used for determining the abnormality of the liquid contact portion. Further, an observation device such as a spectrometer (for example, a device which irradiates a detection target portion with broadband illumination light and measures reflectance distribution of different wavelengths) which is different from the alignment sensors ALG and 90 may be provided near the side surface of the projection optical system PL, and the spectrometer may detect a change in the observation target portion (a change in reflectance distribution corresponding to the presence or absence of a foreign substance, or the like) in the liquid contact portion.

In addition, in the case where ultraviolet pulsed light of excimer laser light is used as the exposure light EL as in this example, there is a possibility that fluorescence (phosphorescence is included in the present specification) is emitted by irradiation of the pulsed light from foreign matter such as resist residue. Therefore, the alignment sensor ALG (or the alignment sensor 90) of the present example is also used as a fluorescence microscope for detecting an image generated by fluorescence emitted from the foreign substances, as needed. In this case, for example, a fluorescent filter that can freely insert and remove only fluorescence to be detected is provided on the incident surface of the observation CCD155 or 156 in fig. 4, and when the alignment sensor ALG is used as the fluorescent microscope, the fluorescent filter may be provided on the incident surface of the CCD155 or 156. In this example, although the alignment sensors (mark detection systems) ALG and 90 are image processing systems, they are not limited to this, and may be other systems such as detecting diffracted light generated from the marks by irradiation of coherent light beams. The optical device for detecting the state of the liquid contact portion is not limited to the alignment sensors ALG and 90, the spectrometer, and the fluorescence microscope, and for example, a detection system or the like for detecting scattered light generated from the liquid contact portion (foreign substance or the like) may be used.

[ description of the measurement station ]

In fig. 1, measurement stage MST includes: the X stage 181, which is elongated in the Y direction and is driven in the X direction, includes an adjustment table 188 mounted thereon via an air bearing, for example, and a measurement table MTB as a measurement unit mounted on the adjustment table 188. For example, the measurement table MTB is mounted on the leveling table 188 via an air bearing, but the measurement table MTB may be integrated with the leveling table 188. The X stage 181 is mounted on the base 54 via an air bearing, for example, so as to be movable in the X direction.

Fig. 5 is a plan view showing substrate stage PST and measurement stage MST in fig. 1, and in fig. 5, X-axis fixing members 186 and 187 are provided in parallel with the X axis so as to sandwich base 54 in the Y direction (non-scanning direction), a plurality of permanent magnets are arranged in a predetermined array in the X direction on the inner surfaces thereof, respectively, and a Y-axis slider 180 which is movable in the X direction is arranged substantially in parallel with the Y direction via moving members 182 and 183 including coils between fixing members 186 and 187, respectively. Substrate stage PST is movably arranged in the Y direction along Y-axis slider 180, and a Y-axis linear motor for driving substrate stage PST in the Y direction is constituted by moving members in substrate stage PST and fixing members (not shown) on Y-axis slider 180, and a pair of X-axis linear motors for driving substrate stage PST in the X direction are constituted by fixing members 186 and 187 corresponding to moving members 182 and 183, respectively. These X-axis and Y-axis linear motors and the like correspond to the substrate stage driving device PSTD in fig. 1.

Further, X-stage 181 of measurement stage MST is arranged to be movable in the X direction via moving members 184 and 185 each including a coil between fixing members 186 and 187, and a pair of X-axis linear motors each driving measurement stage MST in the X direction are configured by moving members 184 and 185 and corresponding fixing members 186 and 187. This X-axis linear motor and the like are shown as measurement stage driving device TSTD in fig. 1.

In fig. 5, a stator 167 having a cross-sectional shape of "コ" and a plate-shaped stator 171 are fixed to the-X direction end of the X stage 181 so as to be substantially parallel to the Y axis, overlap in the Z direction, and face the inner surface in this order, the stator 167 includes a plurality of permanent magnets arranged so as to generate the same magnetic field in the Z direction, the stator 171 includes a coil wound (arranged) substantially in the X axis direction, the moving elements 166A and 166B including a coil wound (arranged) in the Y axis direction are fixed to the lower stator 167 at positions 2 apart in the Y direction of the measurement table MTB, respectively, and the stator 170 includes a plurality of permanent magnets arranged in a predetermined arrangement in the Y direction so as to sandwich the upper stator 171 in the Z direction and fix the stator 170 having a cross-sectional shape of "コ" to the measurement table MTB. X-axis voice coil motors 168A and 168B (see fig. 1) for finely driving the measurement table MTB in the X direction and the θ z direction with respect to the X stage 181 are respectively configured by the lower fixture 167 and the moving members 166A and 166B, and a Y-axis linear motor 169 for driving the measurement table MTB in the Y direction with respect to the X stage 181 is configured by the upper fixture 171 and the moving member 170.

An X-axis mirror 55CX and a Y-axis mirror 55CY are fixed to the measuring table MTB in the-X direction and the + Y direction, respectively, and an X-axis laser interferometer 56C is disposed so as to face the mirror 55CX in the-X direction. The mirrors 55CX, 55CY are shown in fig. 1 as mirror 55C. The laser interferometer 56C is a multi-axis laser interferometer, and the laser interferometer 56C measures the position of the measurement table MTB in the X direction, the rotation angle in the θ z direction, and the like as needed. Instead of mirrors 55CX and 55CY, a reflective surface formed by mirror-finishing the side surface of measurement stage MST, for example, may be used.

On the other hand, in fig. 5, the laser interferometer 56BY for Y-direction position measurement is used in common for the substrate stage PST and the measurement stage MST. That is, the optical axes of the 2 laser interferometers 56BX and 56C on the X axis pass through the center of the projection area AR1 of the projection optical system PL (in this example, the optical axis AX in fig. 1) and are parallel to the X axis, and the optical axis of the Y-axis laser interferometer 56BY passes through the center of the projection area thereof (the optical axis AX) and is parallel to the Y axis. Therefore, normally, when the substrate stage PST is moved to the lower side of the projection optical system PL for scanning exposure, the laser beam of the laser interferometer 56BY is irradiated onto the reflecting mirror 55BY of the substrate stage PST, and the position in the Y direction of the substrate stage PST (substrate P) is measured BY the laser interferometer 56 BY. Further, for example, in order to measure the imaging characteristics of projection optical system PL, when measuring table MTB of measuring stage MST is moved to the lower side of projection optical system PL, the laser beam of laser interferometer 56BY is irradiated onto mirror 55CY of measuring table MTB, and the Y-direction position of measuring table MTB is measured BY laser interferometer 56 BY. In this way, the positions of the substrate stage PST and the measurement table MTB can be measured with high accuracy with reference to the center of the projection area of the projection optical system PL, and the number of expensive laser interferometers can be reduced with high accuracy, thereby reducing the manufacturing cost.

Further, linear encoders (not shown) of an optical system or the like are disposed along the Y-axis linear motor for substrate stage PST and the Y-axis linear motor 169 for measurement table MTB, respectively, and the Y-direction positions of substrate stage PST and measurement table MTB are measured BY the linear encoders while the laser beam of laser beam dryer 56BY is not irradiated to mirrors 55BY or 55 CY.

Returning to fig. 1, the 2-dimensional direction position and the rotation angle of the measurement table MTB are measured BY the laser interferometer 56C and the laser interferometer 56BY (or the linear encoder) of fig. 5, and the measurement results are sent to the control unit CONT. The controller CONT drives the measurement stage driving device TSTD, the linear motor 169, and the voice coil motors 168A and 168B based on the measurement result, thereby moving or positioning the measurement table MTB on the measurement stage MST.

The leveling stage 188 is provided with 3Z-axis actuators capable of controlling the Z-direction position by, for example, an air cylinder or a voice coil motor, and normally controls the Z-direction position, the θ x-direction angle, and the θ y-direction angle of the measurement table MTB so that the upper surface of the measurement table MTB is brought into focus with the image plane of the projection optical system PL by the leveling stage 188. Therefore, an autofocus sensor (not shown) for measuring the position of the surface to be detected such as the upper surface of the substrate P in and near the projection area AR1 is provided near the nozzle member 30, and the operation of the leveling stage 188 is controlled by the control unit CONT based on the measurement value of the autofocus sensor. Further, although not shown, actuators for maintaining the position of the leveling stage 188 with respect to the X-direction, Y-direction, and θ z-direction of the X-stage 181 are provided.

The autofocus sensor also detects tilt information (rotation angle) in the θ x direction and the θ y direction by measuring Z-direction positional information of the surface to be detected at each of the plurality of measurement points, but at least a part of the plurality of measurement points may be set within the liquid immersion area AR2 (or the projection area AR1), or all of the plurality of measurement points may be set outside the liquid immersion area AR 2. Further, for example, when the positional information of the surface to be detected in the Z-axis direction, the θ x direction, and the θ y direction can be measured by the laser interferometers 56B and 56C, the position of the surface to be detected in the Z-axis direction, the θ x direction, and the θ y direction can be controlled by using the measurement results of the laser interferometers 55B and 55C at least during the exposure operation without providing an autofocus sensor that can measure the positional information of the substrate P in the Z-axis direction during the exposure operation.

The measurement table MTB of this example includes measurement instruments (measurement members) for performing various measurements relating to exposure. That is, the measurement table MTB includes: a movable member or the like to which the wire motor 169 is fixed, a measurement table main body 159 of the mirror 55C, and a plate member 101 fixed thereto and made of a light transmissive material having a low expansion rate such as quartz glass. A light shielding film 102 (see fig. 6) made of a chromium film is formed on the entire surface of the plate 101, and a reference mark region FM in which a plurality of reference marks are formed is provided anywhere in a region for a measuring instrument, as disclosed in japanese unexamined patent publication No. 5-21314 (corresponding to U.S. Pat. No. 5243195).

As shown in fig. 5, a pair of fiducial marks FM1 and FM2 for the mask alignment sensor 90 and a fiducial mark FM3 for the substrate alignment sensor ALG in fig. 1 are formed in the fiducial mark region FM on the board 101. By measuring the positions of these reference marks with the corresponding alignment sensors, the amount of the reference line (base line) of the interval (positional relationship) between the projection position of the projection area AR1 of the projection optical system PL and the detection position of the alignment sensor ALG can be measured. In this measurement of the reference line amount, the liquid immersion area AR2 is also formed on the plate 101.

In the area for the measurement on the plate 101, various opening patterns for measurement are formed. As the aperture pattern for measurement, for example, there are aperture patterns for spatial image measurement (for example, slit-shaped aperture patterns 62X and 62Y), pinhole aperture patterns for uneven illumination measurement, aperture patterns for illuminance measurement, aperture patterns for liquid surface aberration measurement, and the like, and a measuring instrument including a corresponding optical system for measuring and a photoelectric sensor is disposed in the measurement table main body 159 on the bottom surface side of these aperture patterns.

Examples of the measuring device include an illuminance unevenness sensor disclosed in, for example, japanese patent laid-open No. 57-117238 (corresponding to U.S. patent No. 4465368), a spatial image measuring device 61 for measuring the light intensity of a pattern spatial image (projection image) projected by a projection optical system PL, for example, japanese patent laid-open No. 2002-14005 (corresponding to U.S. patent application publication No. 2002/0041377), an illuminance monitor disclosed in, for example, japanese patent laid-open No. 11-16816 (corresponding to U.S. patent application publication No. 2002/0061469), and a wavefront aberration measuring device disclosed in, for example, international publication No. 99/60361 (corresponding to european patent No. 1079223).

In this example, in response to performing immersion exposure in which the substrate P is exposed to the exposure light EL through the projection optical system PL and the liquid 1, the exposure light EL is received through the projection optical system PL and the liquid 1 in the above-described uneven illuminance sensor, illuminance monitor, aerial image measuring device, wavefront aberration measuring device, and the like used for measurement using the exposure light EL. Therefore, the light shielding film 102 on the surface of the plate 101 is coated with a lyophobic coating 103 (see fig. 6) except for a specific region described later.

In fig. 5, the measuring table MTB is mainly provided with a nozzle observation device 65 for optically observing the states of the nozzle member 30 and the optical element 2 in fig. 1.

Fig. 6 is a sectional view showing a state where measurement table MTB in fig. 5 is moved to the bottom surface side of projection optical system PL. In fig. 6, an aerial image measuring apparatus 61 including a condenser lens 63 and a photodetector 64 is provided on a measurement stage main body 159 on the bottom surface side of an X-axis aperture pattern 62X, and a photoelectric conversion signal of the photodetector 64 is supplied to a data processing device 57. In this case, the substantially entire surface of the upper surface of the lyophobic coating 103 is a liquid contact portion with which the liquid immersion exposure liquid may come into contact.

However, although the lyophobic coating layer 103 is removed so as to allow the exposure light EL to pass through the substantially circular region 103a including the opening pattern 62X (and the Y-axis opening pattern 62Y in fig. 5) provided in the light shielding film 102, the circular region 103a is also a liquid contact portion. Therefore, when the liquid 1 in fig. 1 is supplied as the liquid immersion area AR2 to the circular area 103a in order to measure the imaging characteristics of the projection optical system PL using the aerial image measuring apparatus 61, if foreign matter is mixed in the liquid 1, the foreign matter is particularly likely to remain in the vicinity of the opening pattern 62X or the like. Therefore, in this example, the circular region 103a of the liquid contact portion from which the lyophobic coating is removed is set as one observation target portion 68G for abnormality determination using the alignment sensor ALG of fig. 1.

In fig. 6, an opening 102b is provided in the light-shielding film 102, and the lyophobic coating layer 103 is removed in order to allow the exposure light EL to pass through a circular region 103b including the opening 102 b. A nozzle observation device 65 including a 2-dimensional imaging element 67 composed of an objective lens 66 and a 2-dimensional CCD is provided in the measurement stage main body 159 on the bottom surface of the opening 102 b. The image pickup signal of the image pickup device 67 is supplied to the data processing device 57, and image data obtained from the image pickup signal is stored in the image memory 58. The resolution of the nozzle observation device 65 (the size of an object on the object surface corresponding to one pixel of the imaging element 67) is set to be, for example, less than several 10 μm.

The liquid contact portion of the nozzle observation device 65 to be observed is the bottom surface of the nozzle member 30, the inside of the supply ports 13 and 14, the inside of the recovery port 24 (including the mesh filter 25), and the bottom surface of the optical element 2, and particularly, foreign matter may be attached to the mesh filter 25, and therefore, for example, the bottom surface of the mesh filter 25 is used as the observation target portion of the nozzle observation device 65. Therefore, in fig. 6, the object surface of the objective lens 66 of the nozzle observation device 65 is set on the bottom surface of the mesh filter 25. The nozzle observation device 65 is further provided with an illumination system (not shown) for illuminating the object to be detected.

In this example, at least one of the plurality of measuring instruments, the reference mark, and the nozzle observation device 65 are provided on the measuring table MTB as measuring members, but the type, number, and/or the like of the measuring members are not limited thereto. As the measuring member, for example, a transmittance measuring instrument for measuring the transmittance of the projection optical system PL may be provided. In addition, only a part of the measuring device or the nozzle observation device 65 may be provided on the measurement stage MST, and the other part may be provided outside the measurement stage MST. Further, members other than the measuring member, for example, cleaning members for cleaning the nozzle member 30, the optical element 2, and the like, are also mounted on the measurement stage MST. As the cleaning member, for example, a cleaning device having a spray nozzle for spraying the liquid 1 or the cleaning liquid to the nozzle member 30 or the like can be used. Further, the measuring stage MST may not be provided with a measuring member, a cleaning member, and the like. At this time, measurement stage MST is disposed to face projection optical system PL by exchanging with substrate stage PST in order to maintain liquid immersion area AR2, for example, at the time of replacement of substrate P. In addition, at least one measuring member may be provided on the substrate stage PST.

[ description of Exposure procedure ]

As shown in fig. 7, a plurality of irradiation regions SH are partitioned (set) on the substrate P. In addition, for convenience of explanation, only a part of the irradiation region SH is shown in fig. 7. In the exposure apparatus EX shown in fig. 1, the controller CONT moves the substrate stage PST while monitoring the output of the laser interferometer 56B, advances the substrate P along a predetermined path with respect to the optical axis AX (projection area AR1) of the projection optical system PL, and sequentially exposes a plurality of shot areas in a step & scan manner. That is, during scanning exposure by exposure apparatus EX, a partial pattern image of mask M is projected onto rectangular projection area AR1 of projection optical system PL, and in synchronization with the movement of mask M in the X direction at velocity V relative to projection optical system PL, substrate P is moved in the X direction at velocity β · V (β is the projection magnification) via substrate stage PST. After the exposure of one shot on the substrate P is completed, the substrate P is moved to the scanning start position of the next shot by the step movement of the substrate P, and then the scanning exposure processing for each shot is sequentially performed while moving the substrate P in the step-and-scan manner.

In the exposure process of the substrate P, the controller CONT drives the liquid supply mechanism 10 to perform a liquid supply operation onto the substrate P. The liquid 1 sent from the liquid supply portion 11 of the liquid supply mechanism 10 flows through the supply tube 12, and is then supplied onto the substrate P through the supply flow paths 82A, 82B formed inside the nozzle member 30. The liquid 1 supplied onto the substrate P flows under the projection optical system PL in accordance with the movement of the substrate P. For example, when the substrate P moves in the + X direction during exposure of an irradiation region, the liquid 1 flows under the projection optical system PL in the + X direction, which is the same as the substrate P, at substantially the same speed as the substrate P. In this state, the exposure light EL emitted from the illumination optical system IL and passing through the mask M is irradiated onto the image plane side of the projection optical system PL, whereby the pattern of the mask M, that is, the liquid 1 passing through the projection optical system PL and the liquid immersion area AR2 is exposed on the substrate P. The control apparatus CONT supplies the liquid 1 on the substrate P by the liquid supply mechanism 10 when the exposure light EL is irradiated on the image plane side of the projection optical system PL, that is, during the exposure operation of the substrate P. The liquid immersion area AR2 is formed satisfactorily by continuing the supply of the liquid 1 by the liquid supply mechanism 10 during the exposure operation. On the other hand, the controller CONT performs recovery of the liquid 1 on the substrate P by the liquid recovery mechanism 20 when the exposure light EL is irradiated on the image plane side of the projection optical system PL, that is, during the exposure operation of the substrate P. During the exposure operation (when the exposure light EL is irradiated onto the image plane side of the projection optical system PL), the liquid 1 on the substrate P is continuously recovered by the liquid recovery mechanism 20, whereby the liquid immersion area AR2 can be suppressed from expanding.

In this example, in the exposure operation, the liquid supply mechanism 10 simultaneously supplies the liquid 1 on the substrate P from both sides of the projection area AR1 through the supply ports 13 and 14. Accordingly, the liquid 1 supplied onto the substrate P from the supply ports 13 and 14 can be favorably spread between the substrate P and the lower end surface of the optical element 2 at the terminal end of the projection optical system PL, and between the substrate P and the lower surface of the nozzle member 30 (the 1 st member 31), thereby forming a liquid immersion area AR2 that is at least wider than the projection area AR 1. In addition, if the supply ports 13 and 14 are connected to other liquid supply units, the amount of liquid supplied per unit time from the front of the projection area AR1 may be set to be larger than the amount of liquid supplied from the opposite side with respect to the scanning direction.

Further, the liquid 1 collecting operation of the liquid collecting mechanism 20 may not be performed during the exposure operation, and after the exposure is completed, the liquid 1 on the substrate P is collected by opening the flow path of the collecting tube 22. For example, the liquid 1 on the substrate P may be collected by the liquid collection unit 21 only during a part of the period from the end of exposure of a certain shot region on the substrate P to the start of exposure of the next shot region (at least a part of the period during which the substrate P is moved in steps).

The controller CONT continues to supply the liquid 1 by the liquid supply mechanism 10 during the exposure of the substrate P. By continuing the supply of the liquid 1, not only can the space between the projection optical system PL and the substrate P be satisfactorily filled with the liquid 1, but also the occurrence of vibration of the liquid 1 (so-called water hammer phenomenon) can be prevented. In this way, all the irradiated regions of the substrate P can be exposed by the liquid immersion method.

Further, for example, during replacement of substrate P, controller CONT moves measurement stage MST to a position facing optical element 2 of projection optical system PL, and forms liquid immersion area AR2 on measurement stage MST. At this time, the substrate stage PST and the measurement stage MST are moved in a state of being brought close to each other, and by arranging one stage to face the optical element 2 instead of the other stage, the liquid immersion area AR2 is moved between the substrate stage PST and the measurement stage MST. The controller CONT performs a measurement (for example, a baseline measurement) related to exposure using at least one measuring instrument (measuring member) mounted on the measurement stage MST in a state where the liquid immersion area AR2 is formed on the measurement stage MST. The details of the movement of moving liquid immersion area AR2 between substrate stage PST and measurement stage MST and the measurement operation of measurement stage MST during substrate P exchange are disclosed in international publication No. 2005/074014 pamphlet (corresponding to european patent application publication No. 1713113), international publication No. 2006/013806 pamphlet, and the like. Further, an exposure apparatus including a substrate stage and a measurement stage is disclosed in, for example, japanese patent laid-open No. 11-135400 (corresponding to the pamphlet of international publication No. 1999/23692) and japanese patent laid-open No. 2000-164504 (corresponding to U.S. patent No. 6897963). The disclosure of U.S. patent No. 6897963 is incorporated herein by reference to the extent permitted by the national directives of the designated and selected countries.

[ Explanation of the Presence or absence of abnormality determination procedure ]

As in the above-described exposure step, when the substrate P in fig. 1 is brought into contact with the liquid 1 in the liquid immersion area AR2, a part of the components of the substrate P may be dissolved in the liquid 1. For example, when a chemically amplified resist is used as the photosensitive material on the substrate P, the chemically amplified resist contains a base resin, a photoacid Generator (PAG: Photo Acid Generator) contained in the base resin, and an amine-based substance called "Quencher". When such a resist contacts the liquid 1, some components of the resist, specifically, PAG, amine-based substances, and the like therein may dissolve in the liquid 1. In addition, when the base material itself (for example, a silicon substrate) of the substrate P comes into contact with the liquid 1, there is a possibility that a part of the components (silicon and the like) of the base material dissolves in the liquid 1 depending on the constitution of the base material.

In this way, the liquid 1 after contacting the substrate P may contain fine foreign substances such as particles made of impurities generated from the substrate P and resist residues. Further, the liquid 1 may contain fine foreign matters such as dust and impurities in the atmosphere. Therefore, the liquid 1 recovered by the liquid recovery mechanism 20 may contain foreign substances such as various impurities. Therefore, the liquid recovery portion 21 discharges the recovered liquid 1 to the outside. Further, at least a part of the recovered liquid 1 may be purified by an internal treatment device, and the purified liquid 1 may be sent to the liquid supply unit 11 to be reused.

In addition, among the foreign substances such as the fine particles mixed in the liquid 1 in the liquid immersion area AR2, foreign substances larger than the mesh size of the mesh filter 25 provided in the recovery port 24 of the nozzle member 30 in fig. 1 may adhere to and remain on the liquid contact portion including the surface (outer surface) of the mesh filter 25. These remaining foreign substances may be mixed again into the liquid 1 in the liquid immersion area AR2 during exposure of the substrate P. If the foreign matter mixed in the liquid 1 adheres to the substrate P, a defect such as a shape defect may occur in a pattern formed on the substrate P.

Therefore, the exposure apparatus EX of the present example determines whether or not the liquid contact portion is abnormal in such a manner that the foreign matter is attached to the liquid contact portion beyond the allowable range of the plurality of observation target portions (detection target portions) determined in advance. The exposure method according to the present embodiment will be described below with reference to the flowchart of fig. 8.

[ step 1]

First, before the exposure process is started, a portion of the liquid contact portion of the exposure apparatus EX set as an observation target portion in advance is imaged by the alignment sensor ALG of fig. 1 and/or the nozzle observation apparatus 65 of fig. 6 (S1), and the obtained 1 st image data is stored as reference observation information (reference information) in the image memory 58 (S2). At this time, on the substrate holder PH, as the substrate P, for example, a wafer coated with a resist starting in a lot having an exposure object loaded thereon is used.

Fig. 7 is a plan view of substrate stage PST in fig. 1, and in fig. 7, traces 60A, 60B, and 60C show the relative movement paths of alignment sensor ALG with respect to substrate holder PH and substrate P on substrate stage PST. In practice, the alignment sensor ALG is stationary and the substrate stage PST (and the measurement stage MST) moves, but for convenience of description, fig. 7 shows the alignment sensor ALG moving relative to the substrate stage PST.

In this case, as described above, in the present example, 4 observation target portions 68A to 68D including the region where foreign substances are likely to adhere between the substrate P and the plate member 97 are set. The shapes of the observation target portions 68A to 68D are substantially the same as the rectangular observation field of view of the alignment sensor ALG, or are formed by connecting a plurality of observation fields in the X direction and the Y direction. In addition, in the measurement of the reference line amount, in a state where the substrate holder PH of fig. 5 is coupled to the measurement table MTB, the alignment sensor ALG moves along the trajectory 60C relative to the substrate holder PH in fig. 7, and moves on the reference mark region FM of fig. 5. At this time, since the liquid immersion area AR2 is formed between the projection optical system PL and the plate 97 or 101 and the movement along the trajectory 60C is performed at an extremely high speed, foreign substances may remain along the trajectory 60C. Therefore, in this example, a plurality of observation target portions 68E and 68F (having the same shape as the observation target portion 68A) are set (here, 2 positions) in the area on the plate 97 along the trajectory 60C. In addition, in the scanning exposure of the irradiation region near the edge of the substrate P, since the liquid immersion region AR moves while partially protruding outside the substrate P, foreign substances may be deposited on the upper surface of the substrate stage PST (plate member 97). Therefore, at least one observation target portion may be set in a region on the plate 97 where the liquid immersion area AR moves during exposure.

As shown in fig. 6, the region including the opening pattern 62X of the lyophobic coating 103 on the measuring table MTB from which the opening pattern is removed is also set as the observation target portion 68G of the alignment sensor ALG, and the bottom surface of the mesh filter 25 of the nozzle member 30 is set as the observation target portion of the nozzle observation device 65. First, the observation target portions 68A to 68F of the substrate holder PH in fig. 7 and the observation target portion 68G on the measurement table MTB in fig. 6 are sequentially moved into the field of view of the alignment sensor ALG, images of the observation target portions 68A to 68G are captured, and the obtained 1 st image data is stored in the image memory 58. Next, the measuring table MTB of fig. 6 is driven in the X direction and the Y direction below the projection optical system PL, and an image of the substantially entire surface of the bottom surface of the mesh filter 25 of the nozzle member 30 is captured by the nozzle observation device 65, and the obtained 1 st image data (here, a combination of a plurality of image data) is stored in the image memory 58.

At this time, the observation target portion can be reset along the region on the measurement table MTB in fig. 5 of the extended locus 60C. In addition to the observation target portions 68A to 68G, an arbitrary number of observation target portions having arbitrary sizes may be set on the substrate holder PH (including on the substrate P) and on the measurement table MTB. The 1 st image data obtained for each of these observation target portions may be stored as reference observation information in the image memory 58. As is clear from fig. 7, the trajectory 60A is substantially similar to the movement path of the exposure-time liquid immersion area AR2 along the irradiation areas SH partitioned on the substrate P, but the trajectories 60B and 60C are different from the movement path of the exposure-time liquid immersion area AR 2.

[ 2 nd step ]

Here, alignment of the substrate P and transfer exposure of the pattern of the mask M to the substrate P using the liquid immersion method are performed in the same manner as described in the above exposure step (S3). At this time, the substrate P and the projection area AR1 of the projection optical system PL of fig. 1 move relatively, for example, along the locus 60A of fig. 7. In practice, the scanning direction of the mask M and the substrate P is reversed for each irradiation region, and therefore the path 60A becomes a more complicated path. Further, a predetermined number of substrates in the same batch are aligned and exposed by a liquid immersion method. After the exposure of the predetermined number of substrates is completed and before the next substrate is exposed, an image of the observation target portion 68A and the like is captured (S4), and the obtained 2 nd image data is stored as the observation information to be detected in the image memory 58 (S5).

At this time, Alignment (Alignment) of the substrate P in fig. 7 is performed by an enhanced wafer Alignment (EGA) method in which Alignment marks located in the measurement regions 69A to 69H within a plurality of irradiation regions selected from the substrate P are detected by the Alignment sensor ALG, and position information of each irradiation region on the substrate P is calculated by statistically processing position information of the detected Alignment marks. This EGA method is disclosed in, for example, Japanese patent application laid-open No. Sho 61-44429 (corresponding to U.S. Pat. No. 4780617). At this time, when the alignment sensor ALG is moved relative to the substrate P along the trajectory 60B to sequentially detect the alignment marks of the measurement regions 69A to 69H for alignment of the substrate P, the observation target portions 68A to 68D located at the nearest positions are sequentially imaged using the alignment sensor ALG. And sequentially stores the resulting 2 nd picture data in the picture memory 58 of fig. 4. For example, when the alignment sensor ALG is moved from the measurement area 69A to the measurement area 69B, the alignment sensor ALG is moved to the observation target portion 68A located in the vicinity thereof, and the 2 nd image data of the observation target portions 68A to 68D can be obtained without increasing the alignment time. In the present example, in the alignment operation, that is, in the alignment mark detection operation, the plurality of observation target portions are continuously detected after the alignment mark of the nearest detection target is detected, but the present invention is not limited to this, and the alignment mark and the observation target portion detection order in which the detection time is shortest may be determined by, for example, a genetic algorithm or the like.

When the alignment sensor ALG is relatively moved along the track 60C to measure the reference line amount before exposure of the substrate P, images of the observation target portions 68E and 68F positioned on the way of the track 60C are captured using the alignment sensor ALG. Further, for example, when the imaging characteristics of the projection optical system PL are measured using the aerial image measuring device 61 of fig. 6, the observation target portion 68G on the aerial image measuring device 61 is first moved to a position below the alignment sensor ALG, and an image of the observation target portion 68G is captured via the alignment sensor ALG. The 2 nd image data of the observation target portions 68E to 68G obtained in this way is sequentially stored in the image memory 58.

Further, for example, when measuring table MTB is moved to the lower side of projection optical system PL in order to measure the reference line amount or move immersion area AR2 from substrate stage PST to measurement stage MST, as shown in fig. 6, measurement table MTB is driven to move nozzle observation device 65 substantially over the entire bottom surface of mesh filter 25 of nozzle member 30 to capture an image of mesh filter 25, and the obtained 2 nd image data is sequentially stored in image memory 58. In this way, when the reference line is measured or the imaging characteristics of the projection optical system PL are measured, the 2 nd image data of the observation target portion 68G on the measurement table MTB and the mesh filter 25 of the nozzle member 30 are added, and the high efficiency of the exposure process can be maintained.

[ 3 rd step ]

Next, after the end of the above-described step 2, under the control of the control apparatus CONT shown in fig. 1, the data processing apparatus 57 shown in fig. 4 (fig. 6) reads out the 1 st image data obtained in the step 1 and the 2 nd image data obtained in the step 2 from the image memory 58 for each observation target portion, and compares the read image data and the read image data, thereby specifying the difference portion between the 2 image data (S6). The identification of the difference portion at this time can be performed at a very high speed by, for example, subtracting the 2 nd image data from the 1 st image data for each pixel data. The specific difference portion can be regarded as a foreign substance attached to the corresponding observation target portion by contact with the liquid 1 during the liquid immersion exposure.

Then, the data processing device 57 recognizes that an abnormality has occurred when the specified difference portion exceeds a predetermined size (for example, 100 μm square) or more or when the luminance (absolute value) of the image after the difference processing is equal to or more than a predetermined value for each observation target portion, and sends information (abnormality content information) such as the position where the abnormality has occurred (the position of the observation target portion where the abnormality has occurred), the number and size of the difference portions, or the difference in luminance to the control device CONT in fig. 1 (S7).

On the other hand, in the 3 rd step, when the difference portion is within the allowable range for any observation target portion, the data processing unit 57 determines that there is no abnormality, and sends the determination result to the control device CONT. At this time, the exposure of the substrate P is performed directly (S8). Then, the above-described 2 nd and 3 rd steps are performed again.

[ 4 th step ]

Next, in the above-described step 3, when the determination result of the abnormality and the abnormality content information are sent from the data processing device 57 to the control device CONT, the control device CONT stops the exposure of the substrate P, for example (S9). Then, a dummy substrate (cover member) made of, for example, a silicon substrate is loaded on the substrate holder PH of fig. 7 instead of the substrate P, and then the liquid contact portion is cleaned (S10). Specifically, the valve 23 in fig. 1 is closed to open the valve 28, and the cleaning liquid is supplied from the cleaning liquid supply unit 26 to the recovery port 24 of the nozzle member 30 through the supply pipe 27, the recovery pipe 22, and the recovery flow path 84. After supplying the cleaning liquid onto the substrate holder PH (plate member 97) and the measuring table MTB, the supplied cleaning liquid is collected by the liquid collecting section 21, and the liquid contact portion is cleaned. In this case, for example, suction devices for liquids may be provided in the substrate holder PH and the measuring table MTB, respectively, and the cleaning liquid may be collected by these suction devices. Alternatively, the cleaning liquid may be supplied to the plate member 97 or the measurement table MTB by vibrating the cleaning liquid using, for example, an ultrasonic oscillator, or the like, or the substrate stage PST or the measurement stage MST may be moved relative to the liquid immersion area while forming the liquid immersion area by supplying and collecting the cleaning liquid at the same time. In the latter case, the number of particles in the cleaning liquid collected from the liquid immersion area may be counted by, for example, a particle counter described later, and the cleaning operation may be controlled based on the counted number. Further, the cleaning of the liquid contact portion may be performed by using the cleaning device of the measurement stage MST. When the dummy substrate has lyophilic properties such as a silicon substrate, a liquid repellent treatment is applied to the upper surface (front surface) of the dummy substrate. As the lyophobic treatment, for example, there is a coating treatment of applying a lyophobic material to form a lyophobic coating. Examples of the material having liquid repellency include synthetic resins such as fluorine compounds, silicon compounds, and polyethylene. The lyophobic coating may be a single layer film or a film composed of a plurality of layers.

Thereafter, the alignment sensor ALG and the nozzle observation device 65 are used again to obtain the 2 nd image data of the observation target portions 68A to 68G and the like (S4 to S5), and the 2 nd image data is compared with the 1 st image data (S6) to determine whether or not there is an abnormality (S7), and exposure is performed on the substrate P at the time when the abnormality disappears (S8). Thereafter, the operation returns to step 2. The frequency of obtaining the 2 nd image data of each observation target portion in the 2 nd step and comparing the image data in the 3 rd step can be set arbitrarily, and can be performed, for example, every batch to 10 batches of exposures. Further, depending on the kind of a film (resist film, topcoat film, or the like) of the substrate, for example, the exposure may be performed every 1 lot or after the exposure of a plurality of substrates in the same lot. Further, the interval between the steps 2 and 3 may be gradually shortened as the number of exposure processing sheets of the substrate increases. The 1 st image data of each observation target portion obtained in the 1 st step may be periodically updated. In this case, the step 1 may be periodically performed, and for example, the 2 nd image data (detection information) obtained after the cleaning operation of the liquid contact portion may be stored as the 1 st image data (reference information).

By providing the above-described step of determining the presence or absence of an abnormality, the probability of exposure in a state where foreign matter adheres to the substrate P can be reduced, and defects such as a defective shape of the transferred pattern can be reduced, so that the yield of the device to be finally manufactured can be improved.

The operations and advantages of the exposure apparatus and the exposure method of the present example are summarized as follows.

A1) In this example, comparing the 1 st image data with the 2 nd image data for each observation target portion makes it possible to more effectively determine the presence or absence of an abnormality, that is, efficiently determine the presence or absence of an abnormality, that is, the presence or absence of adhesion of a foreign substance, which may cause an error in a transferred pattern.

A2) When an abnormality is found in step 3 of this example, the exposure is stopped and the liquid contact portion is cleaned in step 4, whereby the probability of foreign matter being mixed into the liquid is reduced when the next exposure is performed by the immersion method. In addition, in the case where the observation target portion in which an abnormality is found in step 3 is, for example, the observation target portion 68G on the aerial image measuring apparatus 61 of the measuring table MTB in fig. 6, or in the case where the size of the detected foreign matter is small and the number of the detected foreign matters is small, that is, in the case where the possibility that the foreign matter adheres to the substrate P via the liquid is small even when the exposure is performed directly, it is predicted that the substrate P can be exposed directly.

A3) The presence or absence of an abnormality determined in step 3 of this example is the presence or absence of an abnormality in the observation target portion, and in addition, it may be determined that an abnormality is present when, for example, the amount of change in reflectance distribution measured by a spectrometer in the observation target portion is large.

A4) In this example, an alignment sensor ALG of an image processing system for detecting the alignment mark position on the substrate P is used to optically observe the states of the observation target portions 68A to 68G. Therefore, the alignment sensor ALG can be effectively used.

A5) In the above-described step 2, the acquisition of the 2 nd image data of the observation target portions 68A to 68G between the plate 97 and the substrate P in fig. 7 is performed together with the position detection of the predetermined plurality of alignment marks on the substrate P by the alignment sensor ALG. The acquisition of the 2 nd image data of the observation target portions 68E and 68F at 2 on the plate 97 is performed when the reference line amount is measured using the alignment sensor ALG. Therefore, the efficiency of the exposure process is hardly lowered.

The acquisition of the 2 nd image data of the observation target portions 68A to 68D may be performed separately from the alignment operation using the alignment sensor ALG. In this case, when the interval for determining the abnormality of the liquid contact portion is long, the efficiency of the exposure process does not substantially decrease.

A6) In this example, since the mesh filter 25 provided in the liquid recovery port 24 of the nozzle member 30 is used as the observation target portion (a part of the liquid contact portion), the nozzle observation device 65 is provided on the measurement table MTB of fig. 6 on the measurement stage MST. Therefore, the state of the liquid contact portion that cannot be observed with the alignment sensor ALG can be optically observed. Further, the nozzle observation device 65 may be provided on the substrate stage PST (substrate holder PH).

A7) In this example, a circular region 103a including the opening pattern 62X of the lyophobic coating 103 removed on the measurement table MTB of fig. 6 is also set as the observation target portion 68G of the alignment sensor ALG. Since the circular region 103a is likely to have foreign matter attached thereto when liquid is supplied, it is very suitable as an observation target portion. In the observation of the observation target portion 68G and the observation target portions 68E and 68F on the substrate holder PH in fig. 7, the alignment sensor ALG may be formed by the fluorescence microscope by moving the observation target portions to the projection area of the projection optical system PL and irradiating the exposure light EL in advance. In this case, when the foreign substances in the observation target portions 68E to 68G have the property of emitting fluorescence, the foreign substances can be easily detected by detecting the fluorescence by the alignment sensor ALG.

When detecting fluorescence in this manner, in the above-described step 1, exposure light EL may be irradiated to obtain the 1 st image data of the observation target portions 68E to 68G, and the alignment sensor ALG may be set as a fluorescence microscope.

A8) In this example, the alignment sensor ALG and the nozzle observation device 65 are used as devices for optically observing the liquid contact portion, and in addition to this, the above-described spectrometer may be used, or the spectrometer and the imaging device may be used in combination. Further, the optical detection (observation) of the liquid contact portion may be performed by using an optical sensor other than the imaging (image processing) system.

In the above embodiment, the 2 nd image data of the observation target portions 68A to 68D is acquired after the exposure operation of the substrate P, but the 2 nd image data may be acquired after another operation other than the exposure operation. In the above-described embodiment, the presence or absence of an abnormality is determined by focusing on the size and/or brightness (difference) of a specific difference portion in an observation target portion, but the presence or absence of an abnormality may be determined using another feature (for example, density of a difference portion or the like) instead of or in combination with this.

In the above embodiment, the 1 st image data of the observation target portion is acquired in the state where the substrate holder PH holds the substrate P in the 1 st step, but the invention is not limited to this, and the 1 st image data of the observation target portion may be acquired in the state where the virtual substrate is held by the substrate holder PH, for example. In this case, in the 1 st step and the 2 nd step, the position, size, and the like of the observation target portion may be set so that the observation target portion on the substrate holder PH does not include the dummy substrate and the substrate P. In the above embodiment, the 1 st step of acquiring the 1 st image data of the observation target portion is set to be performed immediately before the exposure operation, but the present invention is not limited thereto, and the 1 st image data may be acquired regardless of the exposure operation. For example, the 1 st image data may be acquired at the time of adjustment of the exposure apparatus or at the time of maintenance or the like. In the above embodiment, although the 1 st image data of the observation target portion is stored as the reference information, for example, when the observation target portion is detected using the fluorescence microscope, since fluorescence (phosphorescence) emitted from a foreign substance such as an organic substance is received, the foreign substance of the observation target portion can be detected without using the reference information. Therefore, the reference information (1 st image data) may not be acquired.

In the above embodiment, the abnormality determination (and the cleaning of the liquid contact portion) is performed as a part of the exposure operation, but the abnormality determination may be performed independently of the exposure operation, for example, at the time of maintenance or the like. In the above-described embodiment, the 2 nd and 3 rd steps are performed simultaneously on a plurality of observation target portions, but the 2 nd and 3 rd steps may be performed using a timing and/or interval different from that of another observation target portion, for example, on a part of the plurality of observation target portions. Further, in the above-described embodiment, a plurality of observation target portions are set in the substrate holder PH (plate 97), the nozzle member 30, the measurement table MTB, and the like, but the position, the number, and the like of the observation target portions are not limited thereto and may be set arbitrarily.

EXAMPLE 2 EXAMPLE

Next, an exposure apparatus EX' and an exposure method according to embodiment 2 of the present invention will be described with reference to fig. 9 to 15. In the following description, the same or equivalent components as those in embodiment 1 are given the same reference numerals, and the description thereof is simplified or omitted.

Fig. 9 is a schematic configuration diagram showing a scanning exposure apparatus EX 'of the present example, and in fig. 9, the exposure apparatus EX' includes: the exposure apparatus comprises a mask stage RST for supporting a mask M, a substrate stage PST for supporting a substrate P, an illumination optical system IL for illuminating the mask M supported by the mask stage RST with exposure light EL, a projection optical system PL for projecting a pattern image of the mask M illuminated with the exposure light EL onto the substrate P supported by the substrate stage PST, a control unit CONT for controlling the overall operation of the exposure apparatus EX', a liquid immersion system (liquid immersion mechanism) to which a liquid immersion method is applied, and an alignment sensor ALG for detecting an alignment mark on the substrate P to perform alignment of the substrate P, for example, an image processing system. The liquid immersion system of the present embodiment includes: a liquid supply mechanism 210 for supplying the liquid 1 onto the substrate P, and a liquid recovery mechanism 220 for recovering the liquid 1 supplied onto the substrate P. The exposure apparatus EX' applies the exposure light EL passing through the mask M to the substrate P via the liquid 1 and the projection optical system PL between the projection optical system PL and the substrate P by the local liquid immersion method as in embodiment 1, thereby transferring and exposing the pattern of the mask M to the substrate P.

The structures of illumination optical system IL, mask stage RST and projection optical system PL included in exposure apparatus EX' are the same as those of embodiment 1, and therefore, descriptions thereof are omitted. In the exposure apparatus EX' of this example, pure water is also used as the liquid 1, but unlike embodiment 1, the measurement stage MST is not provided, and various measurement functions are provided on the substrate stage as described below.

The substrate stage PST includes a Z stage 52 that holds the substrate P via a substrate holder (not shown), and an XY stage 53 that supports the Z stage 52, and is mounted on a base 54 via an air bearing, for example, so as to be movable in 2 dimensions. A mirror 55B is provided on Z stage 52, and a laser interferometer 56B is provided at a position opposite to mirror 55B. The 2-dimensional direction position and the rotation angle of the Z stage 52 (substrate P) are measured in real time by the laser interferometer 56B, and the measurement results are output to the control unit CONT. The substrate stage PST is driven by a substrate stage driving device PSTD such as a linear motor. The substrate stage driving device PSTD is controlled by the control device CONT to move or position the substrate stage PST (substrate P) as in embodiment 1.

Further, on the substrate stage PST (Z stage 52), a ring-shaped plate member 257 is provided so as to surround the substrate P. The plate member 257 has a flat surface 257A substantially the same height as the surface of the substrate P held by the substrate holder. Here, although there is a gap of about 0.1 to 1mm between the edge of the substrate P and the plate member 257, in this example, since the resist of the substrate is lyophobic (having a property of repelling the liquid 1) and the liquid 1 has surface tension, the liquid 1 hardly flows into the gap, and even when exposure is performed near the peripheral edge of the substrate P, the liquid 1 can be held between the plate member 257 and the projection optical system PL. Further, in the case where, for example, the substrate holder is equipped with a suction mechanism for discharging the liquid flowing into the gap, the resist (or topcoat layer) of the substrate P does not necessarily have to have liquid repellency.

The liquid supply mechanism 210 supplies a predetermined liquid 1 onto the substrate P, and includes: a1 st liquid supply part 211 and a2 nd liquid supply part 212 capable of sending out the liquid 1, and 1 st and 2 nd supply pipes 211A and 212A having one ends connected to the 1 st and 2 nd liquid supply parts 211 and 212, respectively. The 1 st and 2 nd liquid supply portions 211 and 212 each include: a liquid storage tank for storing the liquid 1, a pressure pump, and the like. The liquid supply mechanism 210 does not need to include all of a liquid tank, a filter unit, a pressure pump, and the like, and at least a part thereof may be replaced with equipment such as a factory in which the exposure apparatus EX' is installed, for example.

The liquid recovery mechanism 220 recovers the liquid 1 supplied onto the substrate P, and includes: a liquid recovery unit 221 capable of recovering the liquid 1, and a recovery pipe 222 (including 1 st to 4 th recovery pipes 222A, 222B, 222C, and 222D, see fig. 10) having one end connected to the liquid recovery unit 221. A valve 224 (composed of 1 st to 4 th valves 224A, 224B, 224C, and 224D, see fig. 10) is provided in the middle of the recovery pipe 222(222A to 222D). The liquid recovery unit 221 includes, for example, a vacuum system (suction device) such as a vacuum pump, a reservoir for storing the recovered liquid 1, and the like. The liquid recovery mechanism 220 does not need to have a vacuum system, a liquid storage tank, or the like, and at least a part thereof may be replaced with equipment such as a factory in which the exposure apparatus EX' is installed.

A particle counter 226 for measuring the number of fine particles (foreign substances) is connected to the middle of the recovery pipe 222 via the branch pipe 225. The particle counter 226 extracts a predetermined volume of liquid at a predetermined sampling rate from the liquid flowing through the recovery pipe 222, irradiates the extracted liquid with a laser beam, and performs image processing on an image of scattered light to measure the number of particles in the liquid. The measured number of particles is supplied to the control unit CONT. The particle counter 226 may be independently provided in each of the 4 recovery pipes 222A to 222D, but may be provided in each of only 1 recovery pipe (for example, the recovery pipe 222A) as a representative. In the case where the particle counters 226 are provided in the 4 recovery pipes 222A to 222D, for example, an average value of the number of particles measured by the 4 particle counters 226 may be used as the measured value of the number of particles.

A nozzle member 230 as a flow path forming member is disposed near the optical element 2 at the end of the projection optical system PL. The nozzle member 230 is an annular member provided around the optical element 2 above the substrate P (substrate stage PST). The nozzle member 30 includes a1 st supply port 213 and a2 nd supply port 214 (see fig. 11) disposed to face the surface of the substrate P. The nozzle member 230 has a supply flow path 282(282A, 282B) therein. One end of the supply channel 282A is connected to the 1 st supply port 213, and the other end is connected to the 1 st liquid supply portion 211 via the 1 st supply tube 211A. One end of the supply flow path 282B is connected to the 2 nd supply port 214, and the other end is connected to the 2 nd liquid supply portion 212 via the 2 nd supply tube 212A. The nozzle member 230 includes 4 recovery ports 223 (see fig. 11) arranged above the substrate P (substrate stage PST) and facing the surface of the substrate P.

Fig. 10 is a schematic perspective view of the nozzle member 230. As shown in fig. 10, the nozzle member 230 is an annular member provided around the optical element 2 at the end of the projection optical system PL, and includes a1 st member 231, a2 nd member 232 disposed above the 1 st member 231, and a3 rd member 233 disposed above the 2 nd member 232. The 1 st to 3 rd members 231 to 233 are plate-like members, respectively, and have holes 231A to 233A in the center thereof, in which the projection optical system PL (optical element 2) can be disposed.

FIG. 11 is a view showing the 1 st member 231 disposed at the lowermost layer among the 1 st to 3 rd members 231 to 233 in FIG. 10. In fig. 11, the 1 st member 231 includes: a1 st supply port 213 formed on the-X direction side of the projection optical system PL for supplying the liquid 1 onto the substrate P, and a2 nd supply port 214 formed on the + X direction side for supplying the liquid 1 onto the substrate P. The 1 st supply ports 213 and 214 are through holes penetrating the 1 st member 231, and are formed in a substantially arc shape in plan view. The 1 st member 231 further includes: a1 st recovery port 223A, a2 nd recovery port 223B, a3 rd recovery port 223C, and a4 th recovery port 223D formed on the-X direction, -Y direction, + X direction, and + Y direction sides of the projection optical system PL for recovering the liquid 1 on the substrate P, respectively. The 1 st to 4 th recovery ports 223A to 223D are also formed to have a substantially arc shape in plan view by penetrating through the through-holes of the 1 st member 231, and are provided at substantially equal intervals along the periphery of the projection optical system PL and outside the supply ports 213 and 214 with respect to the projection optical system PL. The distances between the supply ports 213 and 214 and the substrate P and the distances between the recovery ports 223A to 223D and the substrate P are substantially the same. That is, the height positions of the supply ports 213 and 214 and the height positions of the recovery ports 223A to 223D are substantially the same.

Returning to fig. 9, the nozzle member 230 includes a recovery flow path 284(284A, 284B, 284C, 284D) communicating with the recovery ports 223A to 223D (see fig. 11). The recovery passages 284B and 284D (not shown) are passages for communicating the recovery ports 223B and 223D in the scanning direction in fig. 11 with the recovery pipes 222B and 22D in fig. 12. The other ends of the recovery flow paths 284A to 284D are connected to the liquid recovery unit 221 through recovery pipes 222A to 222D in fig. 10. In this example, the nozzle member 230 is configured as a part of the liquid supply mechanism 210 and the liquid recovery mechanism 220, respectively. That is, the nozzle member 230 is a part of the liquid immersion mechanism of this example.

The 1 st to 4 th valves 224A to 224D provided in the 1 st to 4 th recovery pipes 222A to 222D in fig. 10 are flow paths for opening and closing the 1 st to 4 th recovery pipes 222A to 222D, respectively, and their operations are controlled by the control device CONT in fig. 9. While the flow path of the recovery pipes 222(22A to 222D) is open, the liquid recovery mechanism 220 can suction and recover the liquid 1 from the recovery ports 223(223A to 223D), and when the flow path of the recovery pipes 222(22A to 222D) is closed by the valves 224(224A to 224D), the suction and recovery of the liquid 1 through the recovery ports 223(223A to 223D) are stopped.

In fig. 9, the liquid supply operations of the 1 st and 2 nd liquid supply units 211 and 212 are controlled by the control unit CONT. The controller CONT can independently control the liquid supply amounts per unit time of the 1 st and 2 nd liquid supply portions 211 and 212 to the substrate P. The liquid 1 sent from the 1 st and 2 nd liquid supply portions 211 and 212 is supplied onto the substrate P from the supply ports 213 and 214 (see fig. 13) provided on the lower surface of the nozzle member 230 (the 1 st member 231) so as to face the substrate P through the supply pipes 211A and 212A and the supply flow paths 282A and 282B of the nozzle member 230.

The liquid recovery operation of the liquid recovery unit 221 is controlled by the control unit CONT. The control unit CONT can control the amount of liquid recovered by the liquid recovery unit 221 per unit time. The liquid 1 on the substrate P collected from the recovery port 223 provided on the lower surface of the nozzle member 230 (the 1 st member 231) so as to face the substrate P is recovered to the liquid recovery unit 221 through the recovery flow path 284 of the nozzle member 230 and the recovery pipe 222. A liquid trap surface (inclined surface) 270 having a predetermined length for trapping the liquid 1 is formed by the recovery port 223 of the nozzle member 230 with respect to the lower surface (surface facing the substrate P side) outside the projection optical system PL. The catching surface 270 is subjected to lyophilic treatment. The liquid 1 flowing out to the outside of the recovery port 223 is captured by the capture surface 270.

Fig. 11 is a plan view showing the positional relationship between the 1 st and 2 nd supply ports 213 and 214 and the 1 st to 4 th recovery ports 223A to 223D formed in the nozzle member 230 of fig. 10 and the projection area AR1 of the projection optical system PL. In fig. 11, the projection area AR1 of the projection optical system PL is set to a rectangle whose longitudinal direction is the Y direction. The liquid immersion area AR2 filled with the liquid 1 is formed inside a substantially circular area substantially surrounded by the 4 recovery ports 224A to 224D, includes the projection area AR1, and is locally formed on the substrate P (or includes a part of the substrate P) during the scanning exposure.

The 1 st and 2 nd supply ports 213 and 214 are formed in a slit shape having a substantially circular arc shape on both sides thereof in the scanning direction (X direction) so as to sandwich the projection area AR 1. The lengths of the supply ports 213 and 214 in the Y direction are longer than the length of the projection area AR1 in the Y direction. The liquid supply mechanism 210 can simultaneously supply the liquid 1 from the 2 supply ports 213 and 214 on both sides of the projection area AR 1.

Further, the 1 st to 4 th recovery ports 223A to 223D are formed as arc-shaped slits around the supply ports 213 and 214 and the projection area AR 1. Among the plurality of (4) recovery ports 223A to 223D, the recovery ports 223A and 223C are disposed on both sides thereof in the X direction (scanning direction) so as to sandwich the projection area AR1, and the recovery ports 223B and 223D are disposed on both sides thereof in the Y direction (non-scanning direction) so as to sandwich the projection area AR 1. The lengths of the recovery ports 223A and 223C in the Y direction are longer than the lengths of the supply ports 213 and 214 in the Y direction. The recovery ports 223B and 223D are also formed to have substantially the same length as the recovery ports 223A and 223C, respectively. The recovery ports 223A to 223D are respectively communicated with the liquid recovery unit 221 in fig. 9 via recovery pipes 222A to 222D in fig. 10. In this example, the number of the recovery ports 223 is not limited to 4, and any number or only 1 recovery port may be provided as long as the recovery ports are arranged so as to surround the projection area AR1 and the supply ports 213 and 214.

The nozzle member 230 used in the above embodiment is not limited to the above structure, and examples thereof include those described in european patent publication No. 1420298, international publication No. 2004/055803 pamphlet, international publication No. 2004/057589 pamphlet, international publication No. 2004/057590 pamphlet, and international publication No. 2005/029559 pamphlet (corresponding to U.S. patent publication No. 2006/0231206).

In this example, the supply ports 213 and 214 and the recovery ports 223A to 223D for the liquid are provided in the same nozzle member 230, but the supply ports 213 and 214 and the recovery ports 223A to 223D may be provided in different members. Further, for example, as disclosed in pamphlet of international publication No. 2005/122218, a2 nd recovery port (nozzle portion) for recovering liquid may be provided outside the nozzle member 230. The supply ports 213 and 214 may not be provided to face the substrate P. Further, the lower surface of the nozzle member 230 is set to be substantially the same height (Z position) as the lower end surface (emission surface) of the projection optical system PL, but the lower surface of the nozzle member 230 may be set closer to the image plane side (substrate side) than the lower end surface of the projection optical system PL, for example. In this case, in order to avoid blocking the exposure light EL, a part (lower end portion) of the nozzle member 230 may be submerged below the projection optical system PL (optical element 2).

Fig. 13 is a plan view of Z stage 52 of substrate stage PST as viewed from above. In fig. 13, mirrors 55B are arranged at 2 edges of Z stage 52 that are perpendicular to each other and have a rectangular shape in plan view. The substrate P is held at a substantially central portion on the Z stage 52, and a ring-shaped plate member 257 having a flat surface 257A substantially at the same height as the surface of the substrate P is provided integrally with the Z stage 52 around the periphery of the substrate P.

The flat surface 257 of the plate member 257 has 2 corners each having a wide width, and a fiducial mark FM used for alignment of the mask M and the substrate P with respect to a predetermined position is provided in one of the wide portions. The reference mark FM is detected by a mask alignment system 90 (see fig. 9) provided above the mask M through the mask M and the projection optical system PL. That is, The mask alignment system 90 constitutes a so-called ttm (through The mask) type alignment system. The alignment system ALG of the present example is, for example, a fia (field Image alignment) system disclosed in japanese patent application laid-open No. 7-183186 (corresponding to U.S. Pat. No. 5684569), and includes: an off-axis alignment sensor includes an illumination system for illuminating a region where a mark to be detected is formed, an imaging optical system for forming an image of the mark to be detected, and an image pickup device for photoelectrically converting the image. The image pickup signal from the alignment system ALG is processed by the image processing unit in the control apparatus CONT shown in fig. 9, and thus, the shift amount of the image of the detected mark from the predetermined mark can be obtained, and the X-coordinate and the Y-coordinate of the detected mark can be obtained, and the alignment of the substrate P can be performed based on the coordinates.

The image processing unit of this example also has a function of detecting whether or not a film (resist or the like) on the surface (region to be imaged) of the substrate P has peeled off, based on the imaging signal of the alignment system ALG. In addition, in the vicinity of the alignment system ALG of the exposure apparatus EX of this example, a film thickness measuring apparatus 261 for measuring the film thickness of the resist or the like applied to the substrate P is provided, and the measurement result is also supplied to the control apparatus CONT. The film thickness measuring device 261 measures the film thickness from the state of the interference fringes (such as uniform-thickness interference fringes) of the laser beam, for example. As the film thickness measuring device 261, an Ellipsometer (elipsometer) that detects a change in the polarization state (elliptical polarization, etc.) of the reflected light may be used.

In addition, at the other wide portion of the flat surface 257A of the plate member 257, an optical sensor 258 is provided. The light sensor 258 is an illuminance sensor for detecting the exposure light EL passing through the projection optical system PL and detecting the amount of irradiation (illuminance) of the exposure light EL on the image plane side of the projection optical system PL, or an illuminance unevenness sensor for detecting the illuminance distribution (illuminance unevenness) of the projection area AR 1.

In fig. 9, a plurality of shot regions are set on the substrate P, and the control apparatus CONT sequentially exposes the plurality of shot regions set on the substrate P. In this example, the controller CONT moves the substrate stage PST (XY stage 53) while monitoring the output of the laser interferometer 56B so that the optical axis AX of the projection optical system PL advances along a predetermined trajectory with respect to the substrate P, thereby sequentially exposing a plurality of irradiation regions. That is, during scanning exposure of the substrate P, a partial pattern image of the mask M is projected onto a rectangular projection area AR1 immediately below the terminal end of the projection optical system PL, and the mask M moves in the X direction at a velocity V relative to the projection optical system PL, and the substrate P moves in the X direction at a velocity β · V (β is a projection magnification) via the XY stage 53 in synchronization with this. After the exposure of 1 shot region on the substrate P is completed, the substrate P is moved to the scanning start position of the next shot region by the Step movement of the substrate P, and then the scanning exposure processing for each shot region is sequentially performed while moving the substrate P in a Step-and-Scan (Step & Scan) manner.

In the exposure process of the substrate P, the controller CONT drives the liquid supply mechanism 210 to perform the liquid supply operation on the substrate P. The liquid 1 discharged from the 1 st and 2 nd liquid supply portions 211 and 212 of the liquid supply mechanism 210 flows through the supply pipes 211A and 212A, and is then supplied onto the substrate P through the supply flow paths 282A and 282B formed in the nozzle member 230. The liquid 1 supplied onto the substrate P flows under the projection optical system PL in cooperation with the action of the substrate P. For example, when the substrate P is moved in the + X direction during exposure of a certain irradiation region, the liquid 1 flows under the projection optical system PL in the + X direction in the same direction as the substrate P at substantially the same speed as the substrate P. In this state, the exposure light EL emitted from the illumination optical system IL and passing through the mask M is irradiated on the image plane side of the projection optical system PL, and thereby the pattern of the mask M is exposed to the substrate P via the projection optical system PL and the liquid 1 in the liquid immersion area AR 2.

The controller CONT supplies the liquid 1 on the substrate P by the liquid supply mechanism 210 at least when the exposure light EL is irradiated on the image plane side of the projection optical system PL, that is, during the exposure operation of the substrate P. The liquid immersion area AR2 can be formed satisfactorily by continuing the supply of the liquid 1 by the liquid supply mechanism 210 during the exposure operation. On the other hand, the controller CONT performs the recovery of the liquid 1 on the substrate P by the liquid recovery mechanism 220 at least when the exposure light EL is irradiated onto the image plane side of the projection optical system PL, that is, during the exposure operation of the substrate P. During the exposure operation (when the exposure light EL is irradiated onto the image plane side of the projection optical system PL), the liquid 1 is continuously collected by the liquid collection mechanism 220, whereby the liquid immersion area AR2 can be prevented from expanding.

In this example, in the exposure operation, the liquid supply mechanism 210 simultaneously supplies the liquid 1 onto the substrate P from both sides of the projection area AR1 through the supply ports 213 and 214. Accordingly, the liquid 1 supplied onto the substrate P from the supply ports 213 and 214 can be satisfactorily diffused between the lower end surface of the optical element 2 at the terminal end of the projection optical system PL and the substrate P and between the lower surface of the nozzle member 230 (the 1 st member 231) and the substrate P, and the liquid immersion area AR2 is formed to be larger than at least the projection area AR 1.

When the liquid 1 is supplied to the substrate P from both sides of the projection area AR1 in the scanning direction, the controller CONT controls the liquid supply operation of the 1 st and 2 nd liquid supply units 211 and 212 of the liquid supply mechanism 210 so that the amount of liquid supplied from the front of the projection area AR1 per unit time is set to be larger than the amount of liquid supplied from the opposite side in the scanning direction. In this case, for example, since the substrate P moves in the + X direction, the amount of liquid moving in the + X direction with respect to the projection area increases, and a large amount of liquid may flow to the outside of the substrate P. However, since the liquid 1 moving in the + X direction is caught by the catching surface 270 provided on the lower surface of the + X side of the nozzle member 230, it is possible to prevent a problem such as flowing out or scattering around the substrate P.

In the scanning exposure, the liquid 1 on the substrate P can be recovered by opening the flow path of the recovery tube 222 after the exposure is completed, without recovering the liquid 1 by the liquid recovery mechanism 220. For example, the liquid 1 on the substrate P may be collected by the liquid collection mechanism 220 only during a part of the period (at least a part of the step period) from the end of exposure of a certain shot region on the substrate P to the start of exposure of the next shot region.

The controller CONT continues supply of the liquid 1 using the liquid supply mechanism 210 during exposure of the substrate P. By continuing the supply of the liquid 1 by the liquid supply mechanism 210, not only can the space between the projection optical system PL and the substrate P be satisfactorily filled with the liquid 1, but also the occurrence of vibration of the liquid 1 (so-called water hammer phenomenon) can be prevented. In this way, all the irradiated regions of the substrate P can be exposed by the liquid immersion method.

In the exposure step described above, when the substrate P in fig. 9 is brought into contact with the liquid 1 in the liquid immersion area AR2, the base material (e.g., silicon substrate) of the substrate P and/or a partial component of the material applied thereto may dissolve in the liquid 1. As described previously, for example, in the case where a chemically amplified resist is used as the photosensitive material of the substrate P, the chemically amplified resist contains a base resin, a photoacid generator (PAG) contained in the base resin, and an amine-based substance called "Quencher". When such a resist contacts the liquid 1, some components of the resist, specifically, PAG, amine-based substances, and the like in the resist may dissolve in the liquid 1. In addition, when the base material itself of the substrate P comes into contact with the liquid 1, there is a possibility that a part of the components (silicon and the like) of the base material is dissolved in the liquid 1 depending on the constitution of the base material.

In this way, the liquid 1 after contacting the substrate P may contain fine foreign substances such as particles made of impurities generated in the substrate P and resist residues. Further, the liquid 1 may contain fine foreign matters such as dust and impurities in the atmosphere. Therefore, the liquid 1 recovered by the liquid recovery mechanism 220 may contain foreign substances such as various impurities. Therefore, the liquid recovery mechanism 220 discharges the recovered liquid 1 to the outside. Further, at least a part of the recovered liquid 1 may be purified by an internal treatment device, and the purified liquid 1 may be returned to the liquid supply mechanism 210.

Further, the fine foreign matters such as the fine particles mixed in the liquid 1 in the liquid immersion area AR2 may adhere to and remain on the upper surface of the substrate stage PST. These remaining foreign substances and foreign substances such as particles dissolved in the liquid 1 may be mixed again into the liquid 1 in the liquid immersion area AR2 when the substrate P is exposed. If the foreign matter mixed in the liquid 1 adheres to the substrate P, a defect such as a shape defect may occur in a pattern formed on the substrate P.

The amount of foreign matter dissolved from the substrate P into the liquid 1 varies depending on the type of the substrate P and the material thereon. Therefore, in this example, whether or not the film (resist film and/or topcoat film) of the substrate P is suitable for exposure by the liquid immersion method is determined according to the determination flow of fig. 15.

First, in step 2101 of fig. 15, a resist is coated on a base material of an exposure target substrate by a coating and developing apparatus not shown. In a next step 2102, a top coat is applied over the resist layer.

In next step 2103, after the substrate P having the resist film and the topcoat layer is mounted on the substrate stage PST of the exposure apparatus EX' of fig. 9, the exposure light EL is not irradiated, and as shown in fig. 12, the liquid 1 is supplied from the liquid supply mechanism 210 between the peripheral edge portion of the substrate P and the projection optical system PL to form a liquid immersion area AR2, and the substrate P is moved in the X direction or the Y direction with respect to the liquid immersion area AR2 via the substrate stage PST. That is, as shown in fig. 13, for example, the peripheral edge portion 260A in the-Y direction including the edge portion of the substrate P is relatively scanned along the track 259A in the liquid immersion area AR 2. Next, by scanning the substrate P relative to the liquid immersion area AR2 along the trajectory 259B in fig. 13, as shown in fig. 14, the peripheral edge portions 260B, 260C, 260D in the-X direction, + Y direction, and + X direction of the substrate P are also scanned in the liquid immersion area AR 2.

In this case, in fig. 9, the liquid 1 in the liquid immersion area AR2 is recovered by the liquid recovery unit 221 of the liquid recovery mechanism 220 at a recovery amount per unit time substantially equal to the supply amount per unit time of the liquid 1 supplied from the liquid supply mechanism 210 to the liquid immersion area AR 2. In this collection, the number of particles in the collected liquid is calculated at a predetermined sampling rate by the particle counter 226, and the calculation result is supplied to the control unit CONT.

In the next step 2104, the controller CONT determines whether or not the number of particles supplied from the particle counter 226 is within a predetermined allowable range, and if so, moves to step 2105 to take an image of the state of the peripheral portions 260A to 260D of fig. 14 where the substrate P is scanned in the liquid immersion area AR2, with the alignment sensor ALG, without passing through the liquid 1. In next step 2106, the controller CONT determines whether or not the state of the resist film and the topcoat film is normal in the regions of the peripheral portions 260A to 260D of the substrate P, particularly the edge portions Pe or the vicinity thereof, based on the image captured by the alignment sensor ALG. More specifically, the controller CONT determines whether or not the amount of peeling of at least a part of the resist film and the topcoat film is within an allowable range. When the peeling amount is within the allowable range, the process proceeds to step 2107, where the substrate P is exposed through the mask M by a liquid immersion method.

On the other hand, when the number of particles of the liquid recovered in step 2104 exceeds the allowable range and/or the amount of material peeling in step 2106 exceeds the allowable range, the control device CONT judges that the resist film and/or the top coat film of the substrate P is not suitable for the exposure by the liquid immersion method, and proceeds to step 2108 to stop the exposure of the substrate P, and if necessary, performs cause analysis of the unsuitable exposure of the resist film and/or the top coat film by the liquid immersion method.

As described above, according to this example, since steps 2101, 2103, 2105, and 2106 are performed, it is possible to determine whether or not the film of the substrate P is suitable for the exposure by the liquid immersion method without actually performing the exposure of the substrate P. Therefore, the productivity of the component manufacturing can be improved.

In this example, when an abnormality occurs in the film (here, when the peeling amount of the film exceeds the allowable range) in step 2106, the exposure of the substrate P is stopped (step 2108), and therefore, the subsequent exposure is not wasted.

In this example, since there is a step of applying a topcoat film on the resist of the substrate P (step 2102), it is also possible to determine whether or not the topcoat film is suitable for exposure by the liquid immersion method. Further, when the topcoat film is not required on the resist film, step 2102 may be omitted. In addition, a top coat for antireflection may be applied in step 2102 together with or instead of the top coat for resist protection.

In step 2103, the area on the substrate P scanned with the immersion area AR2 includes at least a part of the edge portion of the substrate P. Since peeling of a film such as a resist film is particularly likely to occur in the edge portion, it is possible to reliably determine whether or not the film material such as the resist film is peeled by exposure to a liquid immersion method. In this example, since the number of particles in the collected liquid is calculated by performing steps 2101, 2103, and 2104, it is possible to determine whether or not a film material such as a resist film of the substrate P is suitable for exposure by the liquid immersion method, and whether or not the amount of the resist or the like dissolved in the liquid is within an allowable range, without actually performing exposure to the substrate P.

In the present embodiment, the number of fine particles contained in the liquid 1 is measured in order to detect an abnormality of the liquid 1 recovered from the recovery port 223 of the liquid recovery mechanism 220, but instead of or together with this, for example, the resistivity, the number of metal ions, organic carbon (TOC), the number of bubbles, the number of bacteria, the concentration of Dissolved Oxygen (DO), the concentration of Dissolved Nitrogen (DN), and the like of the recovered liquid 1 may be measured.

In step 2105 in the determination procedure of fig. 15, after the substrate P is mounted on the substrate stage PST of fig. 9 by inspecting the film state of the substrate P using the alignment sensor ALG, the substrate P is moved in the X direction and the Y direction below the film thickness measuring apparatus 261 of fig. 13, and the film thickness distribution (film thickness unevenness) of the uppermost layer on the substrate P is measured in a dry state without supplying a liquid. And determining whether the film thickness distribution is within an allowable range, that is, whether the film coating unevenness is within an allowable range. Accordingly, it is possible to easily determine whether or not the state of the film (here, film thickness uniformity) is suitable for the exposure by the liquid immersion method without actually performing the exposure.

As a result of this determination, when it is considered that the variation in film thickness exceeds the allowable range, and film peeling is likely to occur or bubbles are likely to be attached (remain) during exposure by the liquid immersion method, the exposure of the substrate P is stopped. In this case, the film may be peeled off and the substrate may be coated with a resist or the like again by the coating and developing apparatus. And exposure is performed after the variation in film thickness of the resist or the like is within the allowable range, so that the waste of the exposure step of the liquid immersion method can be prevented.

In addition, both the inspection of the film state of the substrate P using the alignment sensor ALG and the film state detection using the film thickness measuring apparatus 261 can be performed. The alignment sensor ALG that detects the film state of the substrate P is not limited to the image processing method. In addition, when the film state of the substrate P can be detected only by the alignment sensor ALG or the film thickness measuring device 261, the exposure device EX' may not be provided for inspection in the alignment sensor ALG and the film thickness measuring device 261.

In the present embodiment, before the exposure of the substrate P is performed, it is determined whether or not a film (a resist film and/or a top coat film) of the substrate P is suitable for the liquid immersion exposure, and when it is determined that the liquid immersion exposure is suitable (when yes in step 2106), the liquid immersion exposure of the substrate P is performed. However, if it is determined only whether the film state of the substrate P or the film material is suitable for the immersion exposure, the substrate P may be recovered without performing the exposure of the substrate P after step 2106 of the above-described procedure. In addition, when the film material of the substrate P has a plurality of materials, the above-described steps 2103 to 2106 may be performed for each material, and screening (screening) processing for selecting an optimum material may be performed. In the present embodiment, the virtual substrate described in embodiment 1 may be arranged on the substrate stage PST instead of the substrate P, and information on the abnormality of the nozzle member 230 (presence or absence of foreign matter, etc.) may be acquired by measuring the number of fine particles in the liquid collected from the liquid immersion area AR2 formed on the virtual substrate, for example, by a particle counter.

In addition, in embodiments 1 and 2, the position information of each of mask stage RST, substrate stage PST, and measurement stage MST is measured using interferometer systems (51, 56A to 56C), but the present invention is not limited to this, and an encoder system for detecting a scale (diffraction grating) provided on each stage may be used, for example. In this case, it is preferable that both of the interferometer system and the encoder system are mixed, and the measurement result of the interferometer system is used to correct (calibrate) the measurement result of the encoder system. Further, the position of the stage may be controlled by switching between the interferometer system and the encoder system, or by using both of them.

In addition, in embodiments 1 and 2, the substrate holder PH and the substrate stage PST may be formed integrally, or the substrate holder PH and the substrate stage PST may be separately configured, and the substrate holder PH may be fixed to the substrate stage PST by, for example, vacuum suction. The present invention according to embodiment 1 can be applied to an exposure apparatus in which various measuring instruments (measuring members) are mounted on the substrate stage PST (an exposure apparatus not including the measuring stage MST). The present invention according to embodiment 2 can be applied to an exposure apparatus equipped with a measurement stage having various types of measuring instruments. Only a part of the various measuring instruments may be mounted on the measurement stage MST or the substrate stage, and the rest may be provided outside or other members. The particle counter 226 described in embodiment 2 may be introduced into the exposure apparatus EX of embodiment 1 to perform the processing described in embodiment 2.

In embodiments 1 and 2, water (pure water) is used as the liquid 1 used in the liquid immersion method, but a liquid other than water may be used. For example, the light source of the exposure light EL is F₂For laser light (wavelength 157nm), a fluorine-based fluid such as a fluorine-based oil or a perfluorinated polyether (PFPE) may be used as the liquid 1. In addition to the liquid 1, a liquid that is transparent to the exposure light EL and has a refractive index as high as possible and that is stable to a resist (e.g., cedarwood oil or cedaroil) applied to the projection optical system PL and the surface of the substrate P can be used. In addition, the liquid 1 may have a refractive index higher than that of quartz or fluorite (about 1.6 to 1.8). Further, the optical element 2 may be formed using a material having a higher refractive index than quartz or fluorite (for example, 1.6 or more).

As shown in fig. 16, a microdevice such as a semiconductor device is manufactured and shipped through a function and performance designing step 201 of the microdevice, a step 202 of manufacturing a mask (reticle) based on the designing step, a step 203 of manufacturing a substrate (base material of the device), a substrate processing step 204 including a step of exposing a pattern of the mask to the substrate using exposure apparatuses EX and EX' of the above-described embodiments, a step of developing the exposed substrate, a step of heating and etching the developed substrate, and the like, a device assembling step 205 (a processing step including a dicing step, a bonding step, a packaging step, and the like), and an inspection step 206.

The substrate P of each of the above embodiments can be applied to, in addition to a semiconductor wafer for manufacturing a semiconductor device, a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, a mask or a reticle original plate (synthetic quartz or silicon wafer) used in an exposure apparatus, a sheet-like member, and the like. The shape of the substrate P is not limited to a circular shape, and may be other shapes such as a rectangular shape.

In the above embodiments, although a mask having a transfer pattern formed thereon is used, an electronic mask that forms a transmission pattern or a reflection pattern from electronic data of a pattern to be exposed as disclosed in, for example, U.S. Pat. No. 6778257 may be used instead of the mask. The electronic mask includes a mask (also called a variable shape mask (active mask or image generator), such as a DMD (Digital Micro-mirror Device) which is a kind of non-light emitting type image display Device (spatial light modulator), etc.). The DMD has a plurality of reflection elements (micro mirrors) driven based on predetermined electronic data, and the plurality of reflection elements are arranged in a 2-dimensional matrix on the surface of the DMD and driven in units of pixels to reflect and deflect exposure light. Each reflection assembly can adjust the angle of the reflection surface. The operation of the DMD may be controlled by the control unit CONT. The controller CONT drives the reflection unit of the DMD based on electronic data (pattern information) corresponding to a pattern to be formed on the substrate P, and patterns the exposure light irradiated by the illumination system IL with the reflection unit. By using the DMD, compared with the case of performing exposure using a mask having a pattern formed thereon, since a mask replacement operation and a mask position alignment operation on a mask stage are not required at the time of changing the pattern, the exposure operation can be performed more efficiently. In addition, in an exposure apparatus using an electronic mask, the substrate can be moved in the X-axis and Y-axis directions only by the substrate stage without providing a mask stage. In addition to the above-mentioned U.S. patent, an exposure apparatus using a DMD is disclosed in, for example, Japanese patent application laid-open Nos. 8-313842 and 2004-304135. The disclosure of U.S. patent No. 6778257 is incorporated herein by reference to the extent permitted by the statute of the designated country and the selected country.

Further, the exposure apparatuses EX and EX' are applicable to not only a scanning type exposure apparatus (scanning stepper) of a step-and-scan method for synchronously moving the mask M and the substrate P to expose the pattern of the mask M, but also a projection exposure apparatus (stepper) of a step-and-repeat method for exposing the pattern of the mask M at one time while the mask M and the substrate P are stationary and sequentially moving the substrate P in steps.

The types of exposure apparatuses EX, EX' are not limited to exposure apparatuses for manufacturing semiconductor devices that expose semiconductor device patterns to substrates P, but are widely applicable to exposure apparatuses for manufacturing liquid crystal display devices, thin film magnetic heads, micromachines, MEMS, DNA chips, image pickup devices (CCDs), reticles, masks, and the like.

The exposure apparatus and the exposure apparatus applied to the maintenance method and the exposure method of the present invention do not necessarily include a projection optical system. It is sufficient if the optical member for guiding the exposure light from the light source to the substrate is provided within the range in which the present invention can be implemented. The illumination optical system and the light source may be provided separately from the exposure device. In addition, the mask stage and/or the substrate stage may be omitted in accordance with the exposure method described above.

The present invention can be applied to a multi-stage exposure apparatus having a plurality of substrate stages, which is disclosed in, for example, Japanese patent application laid-open Nos. H10-163099, H10-214783 (corresponding to the specifications of U.S. Pat. Nos. 6341007, 6400441, 6549269 and 6590634), Japanese patent application laid-open No. 2000-505958 (corresponding to the specification of U.S. Pat. No. 5969441), and 6208407. In this case, cleaning is performed for each of the plurality of substrate stages. The disclosure of the above U.S. patent is incorporated as part of the present specification, as far as the domestic regulations of the designated country and the selected country permit.

Further, although the projection optical system according to each of the above embodiments fills the optical path space (liquid immersion space) on the image plane side of the front end optical element with the liquid, for example, a projection optical system in which the mask-side optical path space of the front end optical element is filled with the liquid as disclosed in wo 2004/019128 pamphlet may be used. The present invention can also be applied to a liquid immersion type exposure apparatus in which a liquid immersion area between a projection optical system and a substrate is held by an air curtain (air current) around the liquid immersion area.

In addition, the present invention can also be applied to an exposure apparatus that forms a line & space pattern (line & space pattern) on a substrate by forming interference fringes on the substrate, as disclosed in, for example, pamphlet of international publication No. 2001/035168. In this case, the substrate P is irradiated with the exposure light via the liquid between the optical member and the substrate P.

In the above embodiments, the liquid supply unit and/or the liquid recovery unit need not be provided in the exposure apparatus, but may be replaced with equipment such as a factory in which the exposure apparatus is installed. The structure of the exposure apparatus and the accessories required for the immersion exposure is not limited to the above-described structure, and examples thereof include those described in european patent publication No. 1420298, international publication No. 2004/055803, international publication No. 2004/057590, international publication No. 2005/029559 (corresponding to U.S. patent publication No. 2006/0231206), international publication No. 2004/086468 (corresponding to U.S. patent publication No. 2005/0280791), and japanese patent application laid-open No. 2004-in-charge 289126 (corresponding to U.S. patent No. 6952253). The disclosure of the above-mentioned U.S. patent and U.S. patent publication is incorporated as part of the present specification, insofar as the regulations in the designated country and the selected country permit it.

In the above embodiment, as the liquid 1 used in the liquid immersion method, a liquid having a higher refractive index than water, for example, a refractive index of about 1.6 to 1.8 can be used. Examples of the liquid 1 having a refractive index higher than that of pure water (for example, 1.5 or more) include predetermined liquids having a C-H bond and an o-H bond, such as isopropyl alcohol (isoproapanol) having a refractive index of about 1.50, glycerin (Glycerol) having a refractive index of about 1.61, predetermined liquids (organic solvents) such as hexane, heptane and decane, and Decahydronaphthalene (decadecalene) having a refractive index of about 1.60. Alternatively, the liquid 1 may be a mixture of any 2 or more kinds of these predetermined liquids, or may be added (mixed) to pure waterThe liquid is described. Further, as the liquid 1, H may be added (mixed) to pure water⁺、Cs⁺、K⁺、Cl⁺、SO₄ ^2-、PO₄ ^2-And the like bases or acids. Further, fine particles of Al oxide or the like may be added (mixed) to pure water. Further, the liquid 1 is preferably a material having a small absorption coefficient of light and little temperature dependence and being stable to a photosensitive material (e.g., a top coat film or an antireflection film) applied to the projection optical system PL and/or the surface of the substrate P. As the liquid 1, a supercritical fluid may also be used. In addition, a spacer liquid may be provided on the substrate P to protect the photosensitive material and the top coating film of the base material.

Instead of calcium fluoride (fluorite), the optical element (end optical element) 2 of the projection optical system PL may be formed of a single crystal material of, for example, quartz (silicon dioxide) or a fluorine compound such as barium fluoride, strontium fluoride, lithium fluoride, or magnesium fluoride, or may be formed of a material having a higher refractive index (for example, 1.6 or more) than quartz or fluorite. As the material having a refractive index of 1.6 or more, for example, sapphire, germanium dioxide, or the like can be used as disclosed in pamphlet of international publication No. 2005/059617, or potassium chloride (having a refractive index of about 1.75) can be used as disclosed in pamphlet of international publication No. 2005/059618.

In the case of using the liquid immersion method, for example, as disclosed in pamphlet of international publication No. 2004/019128 (corresponding to U.S. patent publication No. 2005/0248856), the optical path on the object surface side of the terminating optical element is filled with a liquid in addition to the optical path on the image surface side of the terminating optical element. Further, a film having lyophilic and/or dissolution preventing function may be formed on a part (including at least a contact surface with a liquid) or the whole of the surface of the final optical element. Further, quartz has high affinity with a liquid and does not require a dissolution preventing film, but quartz is preferably formed with a minimum amount of the dissolution preventing film.

In the above embodiments, although ArF excimer laser light is used as the light source of the exposure light EL, a harmonic generator which outputs pulsed light having a wavelength of 193nm, including a solid-state laser light source such as DFB semiconductor laser light or fiber laser light, an optical amplifier such as a fiber amplifier, and a wavelength converter, may be used as disclosed in wo 1999/46835 pamphlet (corresponding to U.S. patent No. 7023610). In the above-described embodiment, the projection area (exposure area) has a rectangular shape, but may have another shape such as a circular arc shape, a trapezoidal shape, a parallelogram shape, or a rhombic shape.

Further, as disclosed in, for example, japanese patent application laid-open No. 2004-519850 (corresponding to U.S. patent No. 6611316), the present invention can also be applied to an exposure apparatus in which 2 reticle patterns are synthesized on a wafer through a projection optical system and 1 shot region on the wafer is exposed to double exposure substantially simultaneously by 1 scan. As described above, the present invention is not limited to the above embodiments, and various configurations can be adopted without departing from the scope of the present invention.

As described above, the exposure apparatuses EX and EX' according to the embodiments of the present invention are assembled and manufactured so that various subsystems including the respective components recited in the claims of the present application can maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. In order to ensure the various accuracies described above, before and after the assembly, adjustment for achieving optical accuracy is performed for various optical systems, adjustment for achieving mechanical accuracy is performed for various mechanical systems, and adjustment for achieving various electrical accuracy is performed for various electrical systems. The steps of assembling the various subsystems to the exposure apparatus include mechanical connection, electrical circuit connection, and pneumatic circuit connection among the various subsystems. Before the step of assembling the various subsystems into the exposure apparatus, there is, of course, an assembling step of the various subsystems. After the step of assembling the various subsystems into the exposure apparatus is completed, the overall adjustment is performed to ensure various accuracies of the entire exposure apparatus. In addition, the exposure apparatus is preferably manufactured in a clean room in which temperature, cleanliness, and the like are controlled.

Unless otherwise indicated, the disclosures of various U.S. patents and U.S. patent application publications disclosed in the specification are intended to be part of the disclosure, unless otherwise indicated.

According to the present invention, since it is possible to effectively determine whether or not at least a part of the liquid contact portion of the exposure apparatus that performs exposure by the liquid immersion method is abnormal, when an abnormality is found, the exposure operation is stopped and the progress of cleaning or the like is performed, so that the amount of foreign matter in the liquid immersion area during subsequent exposure can be reduced, and the device can be manufactured with high accuracy. Further, according to the present invention, it is possible to easily determine whether or not the state of the substrate to be exposed or the film state of the substrate is suitable for exposure without actually performing exposure, and it is possible to improve the productivity of device manufacturing. Therefore, the present invention can contribute significantly to the development of the precision machine industry including the semiconductor industry in our country.

Claims (62)

1. An exposure method for exposing a substrate with exposure light through an optical member and a liquid, comprising:

a1 st step of optically observing a state of a detection target portion of at least a part of a liquid contact portion that is in contact with the liquid during a predetermined operation, and storing 1 st observation information obtained;

a2 nd step of optically observing a state of the detected portion after the predetermined operation to obtain 2 nd observation information; and

and a3 rd step of comparing the 1 st observation information with the 2 nd observation information to determine whether the detected part is abnormal.

2. The exposure method according to claim 1, characterized in that:

a liquid immersion space is formed by filling a space between the optical member and the substrate with a liquid, and the substrate is exposed by the exposure light through the optical member and the liquid.

3. The exposure method according to claim 1 or 2, characterized by comprising:

and a4 th step of stopping the exposure operation when the abnormality occurs in the 3 rd step.

4. The exposure method according to any one of claims 1 to 3, characterized in that:

the presence or absence of the abnormality determined in the step 3 is the presence or absence of the foreign matter on the detected part.

5. The exposure method according to any one of claims 1 to 4, characterized in that:

an alignment sensor of an image processing system for detecting the position of the alignment mark on the substrate is used to optically observe the state of the detected portion.

6. The exposure method according to claim 5, characterized in that:

the step 2 is performed when the alignment sensor detects the position of the alignment mark on the substrate.

7. The exposure method according to any one of claims 1 to 6, characterized in that:

an imaging device provided on a stage disposed opposite to the optical member is used to optically observe the state of the detected portion.

8. The exposure method according to any one of claims 1 to 7, characterized in that:

the liquid contact portion is in contact with the liquid at least during exposure of the substrate.

9. The exposure method according to any one of claims 1 to 8, characterized in that:

the liquid contact portion includes at least a part of a liquid immersion space forming member that forms a liquid immersion space by filling a space between the optical member and the substrate with the liquid.

10. The exposure method according to claim 9, characterized in that:

the detection unit includes at least one of a supply port and a recovery port of the liquid in the liquid immersion space forming member.

11. The exposure method according to any one of claims 1 to 10, characterized in that:

the liquid contact portion includes at least a part of a movable member disposed to face the optical member.

12. The exposure method according to claim 11, characterized in that:

the detection section includes a flat surface of the movable member and/or a measurement section.

13. The exposure method according to any one of claims 1 to 10, characterized in that:

the step 2 is performed after the exposure operation of the substrate.

14. The exposure method according to any one of claims 1 to 11, characterized by comprising:

and a step of cleaning the liquid contact portion when there is an abnormality in the step 3.

15. An exposure method for exposing a substrate with exposure light via an optical member and a liquid, comprising:

detecting information relating to a state of a liquid contact portion with which the liquid is in contact during a predetermined operation;

and detecting information relating to an abnormality of the liquid contact portion based on the detection information and reference information relating to a state of the liquid contact portion before the predetermined operation.

16. The exposure method according to claim 15, characterized in that:

the liquid contact portion includes a liquid immersion space forming member that fills a space between the optical member and the substrate with the liquid to form a liquid immersion space; a movable member disposed opposite to the optical member; and at least one of the above optical members.

17. The exposure method according to claim 16, characterized in that:

information on the state of the movable member is detected by a mark detection system that detects a mark on the substrate.

18. The exposure method according to claim 17, characterized in that:

the detection information includes information on a flat surface of the movable member and/or a measurement unit.

19. The exposure method according to claim 17 or 18, characterized in that:

the movable member includes a1 st stage that holds the substrate; at least one of the 2 nd stages that is movable independently of the 1 st stage.

20. The exposure method according to any one of claims 16 to 19, characterized in that:

information relating to the state of the liquid immersion space forming member and/or the optical member is detected by using a detector disposed opposite to the liquid immersion space forming member and/or the optical member.

21. The exposure method according to any one of claims 15 to 20, characterized in that:

the termination or continuation of the exposure operation is determined based on the information relating to the abnormality.

22. The exposure method according to any one of claims 15 to 21, characterized in that:

and determining whether the liquid contact portion needs maintenance or not based on the information relating to the abnormality.

23. The exposure method according to claim 22, characterized in that:

the maintenance includes cleaning and/or replacement of the liquid contact portion.

24. The exposure method according to any one of claims 15 to 23, characterized in that:

the reference information is detected at least before the predetermined operation.

25. The exposure method according to any one of claims 15 to 24, characterized in that:

the reference information includes at least information relating to a state of the liquid contact portion before the liquid contact portion comes into contact with the liquid.

26. The exposure method according to any one of claims 15 to 25, characterized in that:

the predetermined operation includes at least an exposure operation of the substrate.

27. An exposure apparatus for exposing a substrate with exposure light via an optical member and a liquid, comprising:

an optical device for optically observing a state of a detection target portion of at least a part of the liquid contact portion that contacts the liquid;

a memory device for storing the observation information of the optical device; and

and a control device for comparing the observation information of the detected part observed by the optical device for a plurality of times to judge whether the detected part is abnormal.

28. The exposure apparatus according to claim 27, characterized in that:

a liquid immersion space is formed by filling a space between the optical member and the substrate with a liquid, and the substrate is exposed to the exposure light through the optical member and the liquid.

29. The exposure apparatus according to claim 27 or 28, characterized in that:

the control device stops the exposure operation when the detected part has an abnormality.

30. The exposure apparatus according to any one of claims 27 to 29, characterized in that:

the optical device includes an alignment sensor of an image processing system for detecting a position of a mark for alignment on the substrate.

31. The exposure apparatus according to any one of claims 27 to 30, characterized by further comprising:

a stage disposed to face the optical member,

the optical device includes an imaging device provided on the stage.

32. The exposure apparatus according to any one of claims 27 to 31, characterized in that:

the optical device includes a fluorescence microscope that detects fluorescence generated when the exposure light is irradiated to the detection target portion.

33. The exposure apparatus according to any one of claims 27 to 32, characterized in that:

the optical device comprises a spectrometer.

34. The exposure apparatus according to any one of claims 27 to 33, characterized in that:

the liquid contact portion is in contact with the liquid at least during exposure of the substrate.

35. The exposure apparatus according to any one of claims 27 to 34, characterized in that:

the liquid contact portion includes at least a part of a liquid immersion space forming member that fills a space between the optical member and the substrate with the liquid to form a liquid immersion space.

36. The exposure apparatus according to claim 35, characterized in that:

the detection target section includes at least one of a supply port and a recovery port of the liquid in the liquid immersion space forming member.

37. The exposure apparatus according to any one of claims 27 to 36, wherein:

the liquid contact portion includes at least a part of a measurement member disposed to face the optical member.

38. The exposure apparatus according to claim 37, characterized by further comprising:

a stage on which the measuring member is disposed.

39. The exposure apparatus according to any one of claims 27 to 38, characterized by comprising:

and a cleaning member for cleaning the part to be inspected.

40. An exposure apparatus for exposing a substrate with exposure light via an optical member and a liquid, comprising:

an optical device that detects information relating to a state of a liquid contact portion that is in contact with the liquid during a predetermined operation; and

and a controller that detects information relating to an abnormality of the liquid contact portion based on the detection information and reference information relating to a state of the liquid contact portion before the predetermined operation.

41. The exposure apparatus according to claim 40, characterized by comprising:

a movable member disposed opposite to the optical member,

the liquid contact portion includes at least one of the movable member and the optical member.

42. The exposure apparatus according to claim 41, wherein:

the optical device includes a mark detection system that detects a mark on the substrate, and information relating to a state of the movable member is detected by the mark detection system.

43. The exposure apparatus according to claim 41 or 42, wherein:

the optical device detects information relating to the flat surface of the movable member and/or the measurement portion.

44. The exposure apparatus according to any one of claims 41 to 43, wherein:

the movable member includes at least one of a1 st stage that holds the substrate and a2 nd stage that is movable independently of the 1 st stage.

45. The exposure apparatus according to any one of claims 40 to 44, characterized by comprising:

a liquid immersion space forming member for filling the space between the optical member and the substrate with the liquid to form a liquid immersion space,

the liquid contact portion includes the liquid immersion space forming member.

46. The exposure apparatus according to claim 45, wherein:

the optical device includes a detector disposed opposite to the liquid immersion space forming member and/or the optical member.

47. The exposure apparatus according to any one of claims 40 to 46, wherein:

the optical device includes at least one of an imaging device, a fluorescence microscope, and a spectrometer.

48. The exposure apparatus according to any one of claims 40 to 47, wherein:

the control device determines whether to stop or continue the exposure operation according to the information related to the abnormality.

49. The exposure apparatus according to any one of claims 40 to 48, characterized by comprising:

a maintenance member for maintaining the liquid contact portion,

the control device determines whether the maintenance is necessary or not based on the information relating to the abnormality.

50. The exposure apparatus according to claim 49, wherein:

the maintenance member includes a cleaning member for cleaning the liquid contact portion.

51. The exposure apparatus according to any one of claims 40 to 50, wherein:

the reference information is detected at least before the predetermined operation.

52. The exposure apparatus according to any one of claims 40 to 51, characterized in that:

the reference information includes at least information relating to a state of the liquid contact portion before the liquid contacts.

53. A maintenance method for maintaining an exposure apparatus that exposes a substrate via an optical member and a liquid, characterized by comprising:

detecting information relating to a state of a liquid contact portion that is in contact with the liquid during a predetermined operation; and

and detecting information relating to an abnormality of the liquid contact portion based on the detection information and reference information relating to a state of the liquid contact portion before the predetermined operation.

54. The repair method of claim 53, wherein:

the liquid contact portion includes at least one of a liquid immersion space forming member that fills a space between the optical member and the substrate with the liquid to form a liquid immersion space, a movable member disposed opposite to the optical member, and the optical member.

55. The repair method of claim 54, wherein:

the detection information includes information relating to a flat surface and/or a measurement portion of the movable member.

56. The repair method according to claim 54 or 55, wherein:

the detection information includes information relating to a liquid recovery unit of the liquid immersion space forming member.

57. The repair method according to any one of claims 53 to 56, wherein:

and judging whether the maintenance is needed according to the information related to the abnormity.

58. The repair method of claim 57, wherein:

the maintenance includes cleaning and/or replacement of the liquid contact portion.

59. An exposure method for exposing a substrate with exposure light via an optical member and a liquid, comprising:

detecting information relating to a state of a liquid contact portion that is in contact with the liquid during a predetermined operation; and

information relating to an abnormality of the liquid contact portion is detected based on the detection information.

60. The exposure method according to claim 59, wherein:

the detection information includes information obtained by detecting the liquid contact portion with a fluorescence microscope.

61. An exposure apparatus for exposing a substrate with exposure light via an optical member and a liquid, comprising:

an optical device that detects information concerning a state of a liquid contact portion that is in contact with the liquid during a predetermined operation; and

and a control device for detecting information relating to an abnormality of the liquid contact portion based on the detection information.

62. The exposure apparatus according to claim 61, wherein:

the optical device comprises a fluorescence microscope.