JP2009054858A - Immersion lithography apparatus and method for manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an immersion lithography apparatus in which the deterioration of a liquid-repellent material is suppressed. <P>SOLUTION: The immersion lithography apparatus is constituted so that the pattern of an original plate is projected on a substrate through a projection optical system and a liquid so as to expose the substrate, and includes a substrate reference plate arranged on a substrate stage to hold the substrate, and a drive portion to drive a field stop which restricts a measuring light irradiated to the substrate reference plate. The substrate reference plate includes a liquid-repellent property region coated by the liquid-repellent material and a non liquid-repellent property region 28 not coated by the liquid-repellent material, wherein a mark EM to be measured by the measuring light is arranged in the non liquid-repellent property region 28. The field stop restricts the measuring light irradiated to the substrate reference plate so that it is irradiated to the mark arranged in the non liquid-repellent property region 28, and is not irradiated to the liquid-repellent property region. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exposure apparatus, and more particularly to an immersion exposure apparatus that exposes a substrate by projecting an original pattern onto a substrate via a projection optical system and a liquid.

  In a manufacturing process of a semiconductor device composed of a fine pattern such as SI or VLSI, a reduction type projection exposure apparatus that transfers a pattern formed on an original plate on a substrate coated with a photosensitive agent by reducing the projection is used. Yes.

As the integration density of semiconductor devices has increased, further miniaturization of patterns has been demanded, and at the same time as the development of resist processes, the miniaturization of exposure apparatuses has been addressed. As an approach for improving the resolving power of the exposure apparatus, a method of shortening the exposure wavelength and a method of increasing the numerical aperture (NA) of the projection optical system are generally used. The exposure wavelength is shifting from i-line at 365 nm to KrF excimer laser light having an oscillation wavelength near 248 nm, and further development of an ArF excimer laser having an oscillation wavelength near 193 nm is in progress. Further, a fluorine (F ₂ ) excimer laser having an oscillation wavelength near 157 nm has been developed.

  On the other hand, a projection exposure method using an immersion method is attracting attention as a technique for improving resolution, which is completely different from these. Conventionally, the space between the final surface of the projection optical system and the exposure target substrate (for example, wafer) surface is filled with gas, but in the immersion method, this space is filled with liquid to perform projection exposure. The advantage of the immersion method is that the resolution is improved over the conventional method even when a light source having the same wavelength as that of the conventional method is used.

  For example, it is assumed that the liquid provided in the space between the projection optical system and the wafer is pure water (refractive index 1.44), and the maximum incident angle of the light beam that forms an image on the substrate is equal between the immersion method and the conventional method. In this case, the resolution of the immersion method is improved 1.44 times that of the conventional method. This is equivalent to increasing the NA of the projection optical system of the conventional method by 1.44 times. According to the immersion method, it is possible to obtain a resolution of NA = 1 or higher, which is impossible with the conventional method.

  Patent Document 1 discloses an immersion exposure apparatus in which a light receiver is disposed on a substrate stage. The exposure apparatus exposes the substrate by irradiating the substrate disposed on the image plane of the projection optical system with exposure light via the projection optical system and the liquid. An exposure apparatus disclosed even in Patent Document 1 includes a light receiver that receives light that has passed through a projection optical system via a slit plate disposed on an image plane of the projection optical system, and a projection optical system between the projection optical system and the slit plate. And a temperature sensor for detecting temperature information of the filled liquid. Performance information including imaging performance is calculated based on the detection result by the light receiver and the measurement result by the temperature sensor, and this is reflected at the time of exposure.

  Patent Document 2 discloses that a flat plate having a liquid-repellent flat surface at substantially the same height as the substrate is provided on the substrate stage, and that this flat plate can be replaced. Patent Document 2 further discloses that the surface of a reference member having a reference mark disposed on the substrate stage is also liquid repellent and can be replaced. Patent Document 2 further discloses the use of polytetrafluoroethylene as a liquid repellent material.

Patent Documents 3 and 4 disclose a method of performing a liquid repellent treatment on a glass surface. Patent Document 3 discloses that a reactive aqueous emulsion containing an alkoxysilane is applied to a glass surface and dried to form a liquid repellent film. Patent Document 4 discloses a fluorocarbon silane hydrolyzate-containing aqueous emulsion.
JP 2005-116570 A JP 2005-191557 A Japanese Patent Laid-Open No. 10-167767 JP 2001-335893 A

  FIG. 1 is a plan view showing a configuration example of a substrate stage (wafer stage) WST. A substrate reference plate (wafer reference plate) WFP or a measurement unit (not shown) can be arranged around the outside of the substrate (wafer) W. In the immersion exposure apparatus, the immersion area IML is larger than the exposure area (not shown). The liquid contact area IMW is larger than the liquid immersion area IML. The liquid contact area IMW is an area that comes into contact with the liquid as the liquid immersion area IML moves with the exposure operation. A substrate reference plate WFP may be included in the liquid contact area IMW.

  The substrate reference plate WFP may include a mark for calibration of the exposure apparatus or a mark used for alignment between the original (reticle) and the substrate W. The mark included in the substrate reference plate WFP can be detected by an off-axis detection system disposed above the substrate stage WST, an oblique incidence detection system that detects the height inclination of the substrate surface, or via a projection optical system. . Under the substrate reference plate WFP, a light receiving portion that receives the light beam that has passed through the mark is disposed. The substrate reference plate WFP can be configured by drawing a mark on a glass plate. In general, since glass is non-liquid-repellent, the substrate reference plate WFP moves into the immersion area IML during exposure of the substrate or measurement using the substrate reference plate WFP, and thereafter, outside the immersion area IML. If moved to (4), the liquid remains on the substrate reference plate WFP. Furthermore, when the exposure operation is continued from this state, the remaining liquid is scattered, which may change the environment inside the exposure apparatus or generate rust.

  By reducing the speed at which the immersion area IML moves on the substrate reference plate WFP, the remaining amount of the liquid can be reduced to some extent, but it is difficult to eliminate it. Even if the residual liquid can be eliminated, the speed of the substrate stage WST needs to be reduced when exposing the peripheral portion of the substrate W, which causes a problem that the throughput is reduced.

  In Patent Document 2, as described above, the reference member (substrate reference plate) having the reference mark is made liquid repellent, the reference member is replaced when the liquid repellent property is deteriorated, and the liquid repellent material is used. It is disclosed that polytetrafluoroethylene is used as However, when polytetrafluoroethylene is irradiated with excimer laser light, particularly ArF excimer laser light, contamination occurs simultaneously with a decrease in liquid repellency, which may cause defects during exposure of the substrate.

  Further, when the reference member (substrate reference plate) is coated with polytetrafluoroethylene, the surface shape is not stable, and therefore an error may occur when measuring the surface of the reference member with the oblique incidence detection system. Furthermore, since polytetrafluoroethylene has low transmittance with respect to the exposure light and the detection light wavelength of the off-axis detection system, the measurement accuracy can be lowered.

  An object of the present invention is to provide an immersion exposure apparatus in which deterioration of a liquid-repellent material is suppressed, for example, with the recognition of the above-described problems.

  The immersion exposure apparatus of the present invention is configured to project an original pattern onto a substrate through a projection optical system and a liquid to expose the substrate, and a substrate reference plate disposed on a substrate stage holding the substrate; A driving unit that drives a field stop that restricts the measurement light applied to the substrate reference plate, and the substrate reference plate includes a liquid repellent region coated with a liquid repellent material, and a liquid repellent material. A non-liquid-repellent region that is not coated, a mark to be measured with measurement light is disposed in the non-liquid-repellent region, and the field stop is disposed on the mark disposed in the non-liquid-repellent region. Is limited, and the measurement light irradiated on the substrate reference plate is limited so that the liquid repellent area is not irradiated.

  According to the present invention, for example, an immersion exposure apparatus in which deterioration of a liquid repellent material is suppressed is provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 2 is a view showing the schematic arrangement of an exposure apparatus according to a preferred embodiment of the present invention. The exposure apparatus shown in FIG. 2 is configured to project a pattern of an original (reticle) R onto a substrate (wafer) W via a projection optical system 13 and a liquid L to expose the substrate W. Although the exposure apparatus of this embodiment is configured as a scanning exposure apparatus (scanner), the exposure apparatus of the present invention can also be configured as a stepper, for example.

  The original (reticle) R is illuminated by the illumination optical system IL using light provided from the light source 1. Illumination optical system IL includes, for example, shaping optical system 2, fly-eye lens 3, condenser lens 4, field stop 5, movable blind 7, and relay lens 8.

  The illumination optical system IL illuminates the slit-shaped illumination area 21 on the object plane of the projection optical system 13 with uniform illuminance. On the object plane, the original R held by the original stage RST is arranged, and the circuit pattern of the original R in the illumination area 21 is arranged between the projection optical system 13 and the projection optical system 13 and the substrate W. The liquid L is projected onto the substrate W.

The light source 1 is preferably an excimer laser light source such as an F ₂ excimer laser, an ArF excimer laser, or a KrF excimer laser. Also, a metal vapor laser light source, a YAG laser light source, or a mercury lamp can be used.

  The light provided from the light source 1 reaches the fly-eye lens 3 with the light beam diameter set to a predetermined size by the shaping optical system 2. A large number of secondary light sources are formed on the exit surface of the fly-eye lens 3, and illumination light from these secondary light sources is collected by the condenser lens 4 and reaches the movable blind 7 through the fixed field stop 5. In FIG. 2, the fixed field stop 5 is disposed on the condenser lens 4 side relative to the movable blind 7, but the fixed field stop 5 may be disposed on the relay lens 8 side.

  The fixed field stop 5 has a rectangular slit-shaped opening, and the illumination light that has passed through the fixed field stop 5 becomes a light beam having a slit-shaped cross section and enters the relay lens 8. The longitudinal direction of the slit is parallel to the X direction. The relay lens 8 is a lens system that conjugates the movable blind 7 and the surface on which the pattern of the original R is formed. The relay lens 8 is a bilateral telecentric optical system, and the telecentricity is maintained in the slit-shaped illumination area 21 of the original R.

  The movable blind (exposure field stop) 7 defines two blades (light shielding plates) 7a and 7b that define the width in the scanning direction (Y direction) and the width in the non-scanning direction (X direction) perpendicular to the scanning direction. It consists of two blades (not shown). The blades 7a and 7b that define the width in the scanning direction are supported by the drive units 6a and 6b so as to be independently movable in the scanning direction, and the two blades that define the width in the non-scanning direction (not shown) are also independent. It is supported so that it can be driven.

  In this embodiment, the exposure area further limited by the movable blind (exposure field stop) 7 in the slit-shaped illumination area limited by the fixed field stop 5 is illuminated with the exposure light. The circuit pattern in the illumination area 21 of the original R is projected onto the substrate W by the projection optical system 13 and the liquid L.

  The original R is held on the original stage RST. The position of the original stage RST is detected by the interferometer 22 and is driven by the original stage drive unit 10.

  An original reference plate (reticle reference plate) RFP is disposed on the original stage RST. The original reference plate RFP includes a mark for calibrating the exposure apparatus, a reference mark for aligning the original stage RST and the substrate stage WST, and a reference mark for measuring the optical performance of the projection optical system 13. Is arranged.

  Here, in this specification, the direction parallel to the optical axis of the projection optical system 13 is the Z direction, the scanning direction of the original R in a two-dimensional plane perpendicular to the optical axis is the + Y direction (or -Y direction), The direction orthogonal to the Y direction and the Z direction is the X direction.

  The original stage RST holding the original R is driven in the scanning direction (+ Y direction or −Y direction) by the original stage drive unit 10. The movable blind 7 serving as an exposure field stop is driven by a drive mechanism including drive units 6 a and 6 b controlled by the movable blind control unit 11. The original stage drive unit 10 and the movable blind control unit 11 are controlled by the main control system 12.

  The substrate W is transferred by a transfer device (not shown), and is vacuum-sucked by a substrate chuck (wafer chuck) WC disposed on a substrate stage (wafer stage) WST. Substrate stage WST includes a Z stage that positions substrate W in a plane perpendicular to the optical axis of projection optical system 13, an X stage and a Y stage that can scan substrate W in the X direction and the Y direction, and the like. Is done.

  The position of substrate stage WST is detected by interferometer 23. Although only one interferometer 23 is typically shown in FIG. 2, the X, Y direction, the rotation direction around the X axis, and the rotation direction around the Y axis are detected by the interferometer.

  A substrate reference plate (wafer reference plate) WFP is disposed on the substrate stage WST. On the substrate reference plate WFP, a calibration mark for the exposure apparatus, a reference mark for aligning the original stage RST and the substrate stage WST, and a reference mark for measuring the optical performance of the projection optical system 13 are arranged. ing. Although not shown in FIG. 2, a light receiving portion that receives light transmitted through the reference mark is disposed under the substrate reference plate WFP. Further, a coplanar plate WP having a surface substantially the same height as the surface of the substrate W is disposed around the substrate W. For example, the same surface plate WP is fixed to the substrate stage WST by vacuum suction.

  A liquid supply / recovery unit NZ is disposed above the substrate W and on the image plane side of the projection optical system 13. The liquid supply / recovery unit NZ is connected to a supply unit including a liquid supply pipe (not shown), a pump, a temperature control unit, a filter, and the like, and a recovery unit including a liquid recovery pipe, a pump, and a gas-liquid separator. The supply unit and the recovery unit are controlled by the main control system 12.

  Above the substrate W, an off-axis detection system (not shown) and an oblique incidence detection system (not shown) are arranged. The alignment marks arranged on the substrate W and the substrate reference plate WFP are detected by the off-axis detection system, and the height and inclination of the substrate W and the substrate reference plate WFP are detected by the oblique incidence detection system. These pieces of information are sent to the main control system 12.

  The main control system 12 controls the positioning operation and scanning operation of the substrate stage WST via the substrate stage drive unit 18. When the pattern formed on the original R is transferred to each shot area of the substrate W by the scanning exposure method, the −Y direction (or + Y direction) with respect to the slit-shaped illumination area 21 set by the fixed field stop 5 is used. The original is scanned at a speed VR. When the projection magnification of the projection optical system 13 is β, the substrate W is scanned in the + Y direction (or −Y direction) at a speed VW (= β · VR) in synchronization with the scanning of the original plate R. Thereby, the circuit pattern image of the reticle R is sequentially transferred to the shot area of the substrate W.

  FIG. 1 is a plan view of the substrate stage WST. A substrate reference plate WFP is disposed around the substrate W. In FIG. 1, two substrate reference plates WFP are arranged on the substrate stage WST, but one or three or more substrate reference plates WFP may be arranged.

  The liquid contact area IMW is a part in contact with the liquid immersion area IML when the substrate W is exposed. Since at least a partial area of the substrate reference plate WFP is located in the liquid contact area IMW, the substrate reference plate WFP contacts the liquid contact area IMW when the substrate W is exposed.

  FIG. 3 is a plan view showing a configuration example of the substrate reference plate WFP. The substrate reference plate WFP includes a mark area EXP detected using measurement light (hereinafter simply referred to as measurement light) including the same wavelength as the exposure light, a mark area OA detected by an off-axis detection system, and oblique incidence. The region FO detected by the detection system is included.

  The mark area EXP can include an alignment mark for illuminating the reference mark on the original reference plate RFP using measurement light to align the original stage RST and the substrate stage WST via the projection optical system 13. . The mark area EXP may further include an evaluation mark for evaluating the optical performance of the projection optical system 13 and a measurement mark for measuring illuminance.

  FIG. 4 is an enlarged view of the mark area EXP. Here, the alignment mark EM is shown as an example. By simultaneously measuring a plurality of (for example, two) alignment marks, the original stage RST and the substrate stage WST can be more accurately aligned, and the inclination of the substrate stage WST or the substrate reference plate WFP can be determined. Rotation can also be measured.

  On the other hand, as described above, the surface of the substrate reference plate WFP in the immersion exposure apparatus is desirably liquid repellent from the viewpoint of preventing the liquid from remaining there. However, if the region 24 including the plurality of alignment marks EM is made liquid repellent, contamination occurs when the region 24 is irradiated with exposure light. As a method for preventing the occurrence of contamination, it is conceivable that only the region 24 is not coated. However, in this method, an area having low liquid repellency is included on the substrate reference plate WFP, and when the area 24 contacts the liquid immersion area IML, residual liquid may be generated on the substrate reference plate WFP. There is sex.

  Therefore, a coating that increases liquid repellency is applied to the area excluding the alignment mark EM, and the irradiation area is limited to a rectangle by the movable blinds 7 and 27 (FIG. 4), and the plurality of alignment marks EM are individually illuminated. A method is also conceivable. However, in this method, every time the alignment mark EM is measured, it is necessary to drive the movable blind 7 in the scanning direction and the movable blind in the non-scanning direction. In this method, since a plurality of alignment marks EM cannot be measured simultaneously, the processing speed (throughput) of the exposure apparatus may be reduced.

  Therefore, in the first embodiment of the present invention, a measurement movable blind (measurement field stop) 25 different from the movable blind 7 is provided in the illumination optical system IL. The movable movable blind 25 can be used when measuring a mark on the substrate reference plate WFP with measurement light, such as when aligning the original stage RST and the substrate stage WST. The measurement light irradiation area limited by both the movable blind (exposure field stop) 7 and the measurement movable blind (measurement field stop) 25 at the time of measurement is set to the minimum necessary area for mark measurement, thereby reducing the substrate. The amount of residual liquid on the reference plate WFP can be minimized.

  FIG. 5 is a diagram illustrating a configuration example of the measurement movable blind 25. In the example shown in FIG. 5, the movable movable blind 25 for measurement is arranged at substantially the same position as the movable blind 7. The measurement movable blind 25 is configured to be driven in the Y direction by the drive unit 26 independently of the movable blind 7. In the example shown in FIG. 5, the condenser lens 4, the fixed field stop 5, the movable blind (exposure field stop) 7, and the measurement movable blind (measurement field stop) 25 are arranged in this order. You don't have to follow it.

  FIG. 6 is a view showing a state in which the movable blind 7 and the movable movable blind 25 for measurement are viewed from the relay lens 8 side when the alignment mark EM is measured using the movable movable blind 25 for measurement. The region 24 illustrated in FIG. 4 is defined by the movable blind 7 (7a, 7b) that defines the width in the scanning direction and the movable blind (exposure field stop) 27 (27a, 27b) that defines the width in the non-scanning direction. The Further, by inserting the measurement movable blind 25 into the optical path, the area between the two alignment marks EM is prevented from being irradiated to the area between the two alignment marks EM (liquid repellent area). The area is shielded from light. By inserting the measurement movable blind 25 into the optical path, the illumination area is reduced as illustrated as the non-liquid-repellent area 28 in FIG. 7 compared to the area 24 illustrated in FIG. Therefore, the coating with the liquid repellent material for increasing the liquid repellency can be applied to the region between the two alignment marks EM. Here, the non-liquid-repellent area 28 is an area that is not coated with the liquid-repellent material, and areas other than the non-liquid-repellent area 28 in the mark area EXP are coated with the liquid-repellent material. It is a liquid repellent region. The plurality of non-liquid repellent areas 28 are separated from each other by the liquid repellent areas. The non-liquid-repellent region 28 includes an alignment mark EM as a mark to be measured with measurement light. In this embodiment, a field stop for measuring the alignment mark EM is configured by both the movable blind (exposure field stop) 7 and the measurement movable blind (measurement field stop) 25 during measurement. The field stop is irradiated to the alignment mark EM arranged in the non-liquid-repellent region 28 and is not irradiated to the liquid-repellent region other than the non-liquid-repellent region 28. Limit the measurement light emitted to

  Ideally, it is desirable that the movable blind 7 and the movable movable blind 25 are arranged at positions that are conjugate with the alignment mark EM. However, if these cannot be arranged at a conjugate position due to spatial restrictions in the exposure apparatus, the irradiation area may be expanded due to the effect of optical blur. In this case, taking into account the spread of the irradiation area from the arrangement relationship of the movable blind 7, the measurement movable blind 25, and the relay lens 8, the measurement light is not irradiated to the liquid-repellent area coated with the liquid-repellent material. In addition, a non-liquid-repellent region that is not coated may be widened.

  According to this embodiment, the movable blinds (7a, 7b, 27a, 27b) and the movable movable blind 25 can form a plurality of irradiation areas on the substrate reference plate WFP, and a plurality of alignment marks EM. Can be measured simultaneously. Thereby, the throughput of the exposure processing of the substrate W can be improved.

  Further, by driving each movable blind, the size of the irradiation region can be changed, and the irradiation region can be a minimum region necessary for measurement of the alignment mark EM.

  Further, according to this embodiment, since the coating is performed with the liquid repellent material in order to increase the liquid repellency other than the irradiation region irradiated with the measurement light, the liquid repellency on the substrate reference plate WFP is reduced. The occurrence of contamination can be suppressed. The irradiation area is not coated to increase liquid repellency, but the irradiation area is very small, so the residual liquid on the substrate reference plate can fluctuate the environment inside the exposure system or cause rusting. It can be suppressed to an amount that will not be generated.

  The inventors have applied a coating that increases the liquid repellency to the region other than the region 24 on the substrate reference plate WFP and a coating that increases the liquid repellency to the region other than the non-liquid repellant region 28. Prepared with what you did. When the respective areas are in contact with the liquid immersion area, the inventors have generated a large amount of residual liquid in the former, whereas the latter has no residual liquid or the amount of residual liquid compared to the former. It was confirmed by experiment that there was extremely little.

  FIG. 4 illustrates the case where the region 24 includes two alignment marks EM. However, the present invention can be applied to a case where the region 24 includes three or more alignment marks EM. Is possible.

  For example, when the region 24 includes four alignment marks EM, a movable movable blind 29 that can be independently driven in the Y direction is added as shown in FIG. 8 to form four irradiation regions. To do. Then, a coating with a liquid repellent material may be applied outside the irradiation area formed by the movable blind 7 and the movable movable blind 29 to increase the liquid repellency. The measurement movable blind 29 may be configured to be driven by a common drive unit, or may be configured to be driven by an individual drive unit.

  The measurement movable blinds 25 and 29 may be drivable in the X direction. When it is necessary to illuminate an area limited by the field stop 5, the measurement movable blinds 25 and 29 are arranged outside the field stop 5 so as not to block the illumination area. Can be evacuated.

  In addition, when it is not necessary to form a plurality of irradiation regions, a field stop for making one irradiation region minute can be used.

  On the other hand, since the exposure light is not irradiated to the region OA and the region FO, it is possible to perform coating with a liquid repellent material in order to increase the liquid repellency.

  As the coating for forming the liquid repellent region, a coating layer formed by applying and drying a fluorocarbonsilane hydrolyzate-containing aqueous emulsion can be used. As the liquid repellent material, for example, Zonyl TC coat manufactured by DuPont is suitable. In this case, coating can be performed in a thin film state of about 20 to 30 nm, and flatness equivalent to the substrate flatness can be ensured, which is very advantageous when measuring with a measurement system.

  The wavelength range used in the off-axis detection system is, for example, about 400 nm to 800 nm. The same applies to the wavelengths used in the substrate height tilt detection system. In order to coat the surface of the reference mark with Zonyl TC coat and use it for measurement, it is necessary to have a certain reflectance in the wavelength range.

  9A and 9B show reflectance measurement samples. In the sample shown in FIG. 9A, a coating film 32 that partially increases liquid repellency is formed on a quartz glass substrate 30 on which a metal film 31 is deposited. In the sample shown in FIG. 9B, a coating film 32 is partially formed on the quartz glass substrate 30.

  As a result of the reflectance measurement for both samples, the average reflectance in the wavelength range was about 8% in the coated region and the uncoated region in the sample shown in FIG. 9B. It was. In the sample shown in FIG. 9A, both the coated region and the uncoated region have a reflectance of about 60%. The mark formed on the substrate reference plate WFP is generally formed of a metal film such as Cr. From the measurement result of the reflectance described above, when a mark on the substrate reference plate WFP is detected by the off-axis detection system, a reflectance difference of about 50% can be secured, which is sufficient for detecting the mark by image processing. It is possible to obtain contrast.

  The oblique incidence detection system irradiates a detection surface with a detection pattern or detection light by an oblique incidence type optical system, and detects reflected light from the detection surface. Even when the substrate incidence plate WFP is measured by the oblique incidence detection system, the mark can be sufficiently detected if the reflectance is ensured.

  Therefore, a coating with high liquid repellency can be used for the off-axis detection system mark and the reflection surface for the oblique incidence detection system.

[Second Embodiment]
A second embodiment of the present invention will be described. Here, only differences from the first embodiment will be described, and the configuration of the substrate reference plate WFP and the liquid repellent material can be according to the first embodiment.

  In the second embodiment of the present invention, the opening for selectively irradiating the exposure light on the region to be irradiated with the exposure light for measurement on the substrate reference plate WFP is provided in any one of the movable blinds 7a and 7b. Is provided. Furthermore, the size of the opening is optimized with respect to the size of the mark on the substrate reference plate WFP, and the irradiation area is set to the minimum necessary area for measurement, thereby reducing the amount of residual liquid on the substrate reference plate WFP Can be minimized.

  FIG. 10 is a diagram illustrating an example of the movable blind 7 according to the second embodiment. As shown in FIG. 10, the movable blind 7 b has an opening 35. In the second embodiment, when measuring the alignment mark EM, an area including the opening 35 of the movable blind 7b is inserted into the optical path of the measurement light. Only the light beam that has passed through the opening 35 illuminates the substrate reference plate WFP. Therefore, as in the first embodiment, the illumination area can be reduced as shown as the non-liquid-repellent area 28 in FIG. 7 compared to the area 24 shown in FIG. Therefore, the coating with the liquid repellent material can be applied to the areas other than the non-liquid repellent area 28.

  Compared to the first embodiment, in this embodiment, it is not necessary to add a new movable blind, and only an opening is added to the movable blind 7.

  Ideally, it is desirable that the movable blind 7 be disposed at a position conjugate with the alignment mark EM. However, when the movable blind 7 cannot be disposed at a conjugate position due to spatial restrictions in the exposure apparatus, The irradiation area may be expanded due to the effect of optical blur. In such a case, the measurement light is not irradiated onto the liquid-repellent region that has been coated in order to increase the liquid-repellent property in consideration of the spread of the irradiation region based on the positional relationship between the movable blind 7 and the relay lens 8. In addition, a non-liquid-repellent region that is not coated may be widened.

  According to this embodiment, a plurality of alignment marks EM can be simultaneously measured by configuring a plurality of openings. By optimizing the size of the opening with respect to the size of the alignment mark EM, it is possible to make the irradiation region a minimum region necessary for measurement.

  According to this embodiment, since the coating with the liquid repellent material for increasing the liquid repellency is performed only outside the irradiation region, the decrease in the liquid repellency on the substrate reference plate WFP and the occurrence of contamination are suppressed. Can do. Although the coating that increases the liquid repellency is not applied to the irradiated area, the irradiated area is a very small area, so the residual liquid on the substrate reference plate may fluctuate the internal environment of the exposure device or generate rust. The amount is not reduced.

  FIG. 10 shows a case where the movable blind 7b has only two openings 35. However, the openings may be configured in any movable blind, and the number thereof may be one or three or more. But you can.

  In addition to the movable blind 7 and the movable blind 27, a blind that can be driven in at least one of the scanning direction and the non-scanning direction and has an opening may be newly configured. However, in any case, the aperture is positioned outside the region limited by the field stop 5 within the driving range of the movable blind so that the illumination light does not pass through the aperture during scanning exposure of the substrate W or the like. Need to be placed.

  In this embodiment, a rectangular opening is shown, but the shape of the opening is not limited to this, and may be a polygonal shape, a circular shape, or an elliptical shape.

[Third Embodiment]
A third embodiment of the present invention will be described. In the third embodiment, only differences from the first and second embodiments will be described, and the configuration of the substrate reference plate WFP and the liquid repellent material can be in accordance with the first embodiment.

  Also in the second embodiment, when the mark on the substrate reference plate WFP is measured with the measurement light, such as when the original stage RST and the substrate stage WST are aligned, the irradiation area is minimized. In the third embodiment, a light shield is arranged on the circuit pattern surface of the original R or the reference mark surface of the original reference plate RFP to reduce the irradiation area on the substrate reference plate WFP.

  The light shielding body in this embodiment is configured on the circuit pattern surface of the original R or the reference mark surface of the substrate reference plate RFP, and takes the form of a metal film. 11 and 12 are diagrams showing an example in which a light-shielding body 37 made of a metal film is formed on the reference mark surface of the original reference plate RFP. An opening 39 is formed in the light shield 37 and functions as a field stop for measurement. The opening 39 includes a reference mark (not shown) used for aligning the original stage RST and the substrate stage WST. According to this embodiment, as in the first embodiment, the illumination area can be reduced as shown as the non-liquid-repellent area 28 in FIG. 7, compared with the area 24 shown in FIG. The coating for increasing the thickness can be applied to the areas other than the non-liquid-repellent area 28.

  Compared with the first and second embodiments, in the third embodiment, the configuration and driving of the current movable blind are not changed, but on the circuit pattern surface of the original R or on the reference mark surface of the original reference plate RFP. It is only necessary to add a metal film. Accordingly, since it is not necessary to drive a new movable blind, even if it is necessary to measure the alignment mark EM during the substrate exposure process, the wafer processing speed is not reduced.

  According to the third embodiment, the irradiation area on the substrate reference plate WFP can be a minimum area necessary for measurement. In addition, since the coating that increases the liquid repellency is applied only outside the irradiation region, it is possible to suppress the decrease in liquid repellency on the substrate reference plate WFP and the occurrence of contamination. Although the coating that increases the liquid repellency is not applied to the irradiated area, the irradiated area is a very small area, so the residual liquid on the substrate reference plate may fluctuate the internal environment of the exposure device or generate rust. The amount is not reduced.

[Others]
In each of the above embodiments, a rectangular opening is exemplified, but the shape of the opening is not limited to this, and various shapes such as a polygonal shape, a circular shape, and an elliptical shape can be adopted.

  In the present invention, not only the alignment of the original stage and the substrate stage but also the exposure light to the substrate reference plate needs to be irradiated, for example, wavefront aberration measurement, birefringence measurement, pupil transmittance distribution measurement of the projection optical system It is also applicable when measuring the illuminance on the substrate surface.

  Moreover, although the 1st-3rd embodiment was comprised separately until now, you may use combining these.

  In each of the above embodiments, the exposure apparatus having one substrate stage is exemplified, but the exposure apparatus may have a plurality of substrate stages. In this case, the substrate reference plate disposed on each substrate stage may have the configuration exemplified as the embodiment.

[Application example]
Next, a device manufacturing method using the above exposure apparatus will be described. FIG. 13 is a diagram showing a flow of an entire manufacturing process of a semiconductor device. In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (reticle fabrication), a reticle (also referred to as an original or a mask) is fabricated based on the designed circuit pattern. On the other hand, in step 3 (wafer manufacture), a wafer (also referred to as a substrate) is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the reticle and wafer. The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, and is an assembly process (dicing, bonding), packaging process (chip encapsulation), etc. Process. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

  FIG. 14 shows a detailed flow of the wafer process. In step 11 (oxidation), the wafer surface is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (CMP), the insulating film is planarized by a CMP process. In step 16 (resist process), a photosensitive agent is applied to the wafer. In step 17 (exposure), the above exposure apparatus is used to expose a wafer coated with a photosensitive agent through a mask on which a circuit pattern is formed, thereby forming a latent image pattern on the resist. In step 18 (development), the latent image pattern formed on the resist on the wafer is developed to form a resist pattern. In step 19 (etching), the layer or substrate under the resist pattern is etched through the portion where the resist pattern is opened. In step 20 (resist stripping), the resist that has become unnecessary after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

It is a top view which shows the structural example of the substrate stage (wafer stage) WST. It is a figure which shows schematic structure of the exposure apparatus of suitable embodiment of this invention. It is a top view which shows the structural example of the board | substrate reference | standard plate WFP. It is an enlarged view of the mark area EXP. It is the schematic which shows an example of the movable blind for a measurement in 1st Embodiment of this invention. It is the schematic which shows an example of the movable blind for a measurement in 1st Embodiment of this invention. It is a figure which shows the mark area | region EXP containing the non-liquid repellency area | region and liquid repellency area | region in 1st Embodiment of this invention. It is the schematic which shows an example of the movable blind for a measurement in the 1st Embodiment of this invention. It is a figure which shows a reflectance measurement sample. It is a figure which shows a reflectance measurement sample. It is the schematic which shows an example of the movable blind in 2nd Embodiment of this invention. It is the schematic which shows the structure of the light-shielding body in 3rd Embodiment of this invention. It is the schematic which shows the light-shielding body in 3rd Embodiment of this invention. It is a figure which shows the flow of the whole manufacturing process of a semiconductor device. It is a figure which shows the flow of the whole manufacturing process of a semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Shaping optical system 3 Fly eye lens 4 Condenser lens 5 Fixed field stop 6a, 6b Driving part 7a, 7b Blade (movable blind)
DESCRIPTION OF SYMBOLS 8 Relay lens 10 Original stage drive part 11 Movable blind control part 12 Main control system 13 Projection optical system 21 Illumination area 22, 23 Interferometer 25 Movable blind 26 for measurement 26 Drive part 27a, 27b Movable blind 29 Measurement movable blind 31 Metal film 32 Coating film 32
35 Opening 37 Light-shielding body WST Substrate stage WFP Substrate reference plate IML Immersion area IMW Liquid contact area RST Substrate stage REF Substrate reference plate EXP Mark area EM Alignment mark

Claims (9)

An immersion exposure apparatus that projects an original pattern onto a substrate through a projection optical system and a liquid to expose the substrate,
A substrate reference plate disposed on a substrate stage for holding the substrate;
A drive unit that drives a field stop that restricts the measurement light applied to the substrate reference plate;
The substrate reference plate includes a liquid repellent area coated with a liquid repellent material and a non-liquid repellent area not coated with the liquid repellent material, and the non-liquid repellent area is measured with measurement light. The mark that should be placed
The field stop limits the measurement light irradiated to the substrate reference plate so that the mark arranged in the non-liquid-repellent region is irradiated and the liquid-repellent region is not irradiated.
An immersion exposure apparatus.   The field stop includes an exposure field stop that limits an exposure area of the substrate at the time of exposure of the substrate and a measurement field stop that is not used at the time of exposure of the substrate. At the time of measurement, both the exposure field stop and the measurement field stop The immersion exposure apparatus according to claim 1, wherein measurement light irradiated on the substrate reference plate is limited by the step.   The immersion exposure apparatus according to claim 1, wherein the field stop is configured by providing an opening in an exposure field stop that limits an exposure area of the substrate during exposure of the substrate.   The immersion exposure apparatus according to claim 1, wherein the field stop is provided on an original plate.   The immersion exposure apparatus according to claim 1, wherein the field stop is provided on an original stage holding the original.   The substrate reference plate includes a plurality of non-liquid-repellent areas separated by liquid-repellent areas, and a mark to be measured with measurement light is arranged in each non-liquid-repellent area. The immersion exposure apparatus according to any one of claims 1 to 5.   The immersion exposure apparatus according to claim 6, wherein the field stop is configured to simultaneously irradiate the plurality of non-liquid-repellent regions with the measurement light.   The immersion exposure apparatus according to claim 1, wherein the measurement light includes the same wavelength as the wavelength of exposure light. A device manufacturing method comprising:
Exposing the substrate using the immersion exposure apparatus according to any one of claims 1 to 8,
Developing the substrate;
A device manufacturing method comprising:

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