Source: https://patents.google.com/patent/JP2011097121A/en
Timestamp: 2019-12-07 16:54:24
Document Index: 106243091

Matched Legal Cases: ['art 50', 'art 11', 'art 11', 'art 21', 'art 41', 'art 41', 'art 11', 'art 31']

JP2011097121A - Exposure apparatus, exposure method and device manufacturing method - Google Patents
JP2011097121A
JP2011097121A JP2011032385A JP2011032385A JP2011097121A JP 2011097121 A JP2011097121 A JP 2011097121A JP 2011032385 A JP2011032385 A JP 2011032385A JP 2011032385 A JP2011032385 A JP 2011032385A JP 2011097121 A JP2011097121 A JP 2011097121A
JP2011032385A
JP5152356B2 (en
JP2011097121A5 (en
Tatsu Sugawara
Soichi Yamato
龍 菅原
2004-08-03 Priority to JP2004227226 priority
2011-02-17 Priority to JP2011032385A priority patent/JP5152356B2/en
2011-02-17 Application filed by Nikon Corp, 株式会社ニコン filed Critical Nikon Corp
2011-03-01 First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=35787091&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=JP2011097121(A) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
2011-05-12 Publication of JP2011097121A publication Critical patent/JP2011097121A/en
2012-05-31 Publication of JP2011097121A5 publication Critical patent/JP2011097121A5/en
2013-02-27 Publication of JP5152356B2 publication Critical patent/JP5152356B2/en
238000007654 immersion Methods 0 abstract 4
<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus capable of grasping the state of liquid immersion area of liquid. <P>SOLUTION: The exposure apparatus EX is equipped with a projection optical system PL, and the projection optical system PL is provided with a first optical element LS1 closest to the image plane of the projection optical system PL. In this case, the exposure apparatus EX is equipped with a first liquid immersion mechanism 1, which forms a first liquid immersion region LR1 of first liquid LQ1, between the upper surface 65 of a transparent member 64 provided on the image surface side of the projection optical system PL and a first optical element LS1; and an observation device 60 for observing the state of the first liquid immersion region LR1. <P>COPYRIGHT: (C)2011,JPO&INPIT
The present invention relates to an exposure apparatus that exposes a substrate through a liquid, an exposure method, and a device manufacturing method.
Semiconductor devices and liquid crystal display devices are manufactured by a so-called photolithography technique in which a pattern formed on a mask is transferred onto a photosensitive substrate. An exposure apparatus used in this photolithography process has a mask stage for supporting a mask and a substrate stage for supporting a substrate, and a mask pattern is transferred via a projection optical system while sequentially moving the mask stage and the substrate stage. It is transferred to the substrate. In recent years, in order to cope with higher integration of device patterns, higher resolution of the projection optical system is desired. The resolution of the projection optical system becomes higher as the exposure wavelength used is shorter and the numerical aperture of the projection optical system is larger. Therefore, the exposure wavelength used in the exposure apparatus is shortened year by year, and the numerical aperture of the projection optical system is also increasing. The mainstream exposure wavelength is 248 nm of the KrF excimer laser, but the 193 nm of the shorter wavelength ArF excimer laser is also being put into practical use. Also, when performing exposure, the depth of focus (DOF) is important as well as the resolution. The resolution R and the depth of focus δ are each expressed by the following equations.
R = k 1 · λ / NA (1)
Here, λ is the exposure wavelength, NA is the numerical aperture of the projection optical system, and k 1 and k 2 are process coefficients. From the equations (1) and (2), it can be seen that the depth of focus δ becomes narrower when the exposure wavelength λ is shortened and the numerical aperture NA is increased in order to increase the resolution R.
If the depth of focus δ becomes too narrow, it becomes difficult to match the substrate surface with the image plane of the projection optical system, and the focus margin during the exposure operation may be insufficient. Therefore, as a method for substantially shortening the exposure wavelength and increasing the depth of focus, for example, a liquid immersion method disclosed in Patent Document 1 below has been proposed. In this 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 to form an immersion region, and the wavelength of exposure light in the liquid is 1 / n of that in air. (Where n is the refractive index of the liquid, which is usually about 1.2 to 1.6), the resolution is improved, and the depth of focus is expanded about n times.
By the way, in order to perform exposure processing based on the immersion method satisfactorily, it is indispensable to make the immersion region in a desired state. For this reason, it is desirable to perform exposure processing after confirming the state of the liquid immersion area and confirming that the liquid immersion area is in the desired state.
The present invention has been made in view of such circumstances, and provides an exposure apparatus and an exposure method capable of grasping the state of a liquid immersion area, and a device manufacturing method using the exposure apparatus and the exposure method. For the purpose.
In order to solve the above-described problems, the present invention employs the following configurations corresponding to the respective drawings shown in the embodiments. However, the reference numerals with parentheses attached to each element are merely examples of the element and do not limit each element.
According to the first aspect of the present invention, the substrate (P) is interposed between the projection optical system (PL) and the liquid (LQ1) in the immersion region (LR1) formed on the image plane side of the projection optical system (PL). ), The projection optical system (PL) has a first optical element (LS1) closest to the image plane of the projection optical system (PL), and is located on the image plane side of the projection optical system (PL). An immersion mechanism (12, 14 etc.) for forming an immersion area (LR1) of the liquid (LQ1) between the provided predetermined surface (65) and the first optical element (LS1); and an immersion area (LR1) An exposure apparatus (EX) provided with an observation apparatus (60) for observing the state of ().
According to the second aspect of the present invention, the substrate (P) is interposed between the projection optical system (PL) and the liquid (LQ2) in the immersion region (LR2) formed on the image plane side of the projection optical system (PL). ), The projection optical system (PL) is closest to the image plane next to the first optical element (LS1) closest to the image plane of the projection optical system (PL) and the first optical element (LS1). A liquid immersion mechanism (32) having a second optical element (LS2) and forming a liquid immersion area (LR2) of the liquid (LQ2) between the first optical element (LS1) and the second optical element (LS2). , 34, and the like) and an observation apparatus (60) for observing the state of the liquid immersion area (LR2) are provided.
According to the third aspect of the present invention, the substrate (P) is exposed through the optical element (LS1) and the liquid (LQ1) in the liquid immersion area (LR1) formed on the light emission side of the optical element. In the exposure apparatus, an immersion mechanism (12, 14 etc.) for filling a space between the predetermined surface (65) arranged on the light emission side of the optical element (LS1) and the optical element (LS1), an optical An exposure apparatus (EX) including an observation apparatus (60) for observing the state of the liquid (LQ1) between the element (LS1) and a predetermined surface (65) is provided.
According to the first to third aspects of the present invention, since the observation device for observing the state of the immersion region is provided, the formed immersion region is in a desired state based on the observation result of the observation device. It can be confirmed whether or not. Then, after determining that the formed immersion area is in a desired state based on the observation result of the observation apparatus, the substrate is exposed through the liquid in the immersion area, for example, by exposing the substrate, for example. be able to. On the other hand, when it is determined that the formed immersion area is not in the desired state based on the observation result of the observation apparatus, an appropriate treatment for bringing the immersion area into the desired state, for example, replacement of the liquid is performed. Can do.
According to the fourth aspect of the present invention, there is provided a device manufacturing method using the exposure apparatus (EX) of the above aspect.
According to the fourth aspect of the present invention, after confirming that the formed immersion region is in a desired state, exposure processing and measurement processing for manufacturing a device through the liquid in the immersion region are performed. It can be done well. Therefore, a device having desired performance can be provided.
According to the fifth aspect of the present invention, the liquid (LQ1 and / or LQ2) in the liquid immersion region (LR1 and / or LR2) formed on the light emission side of the optical element (LS1 and / or LS2) is used. An exposure method for exposing a substrate (P), wherein the substrate is exposed through the liquid in the immersion area, the exposed substrate (P) is replaced with an unexposed substrate (P), And detecting a gas portion in the liquid of the immersion area during the exchange.
According to the fifth aspect of the present invention, by detecting a gas portion in the liquid in the liquid immersion region, the state of the liquid immersion region is grasped, and a necessary treatment is appropriately performed on the liquid immersion region. The immersion area can be maintained. In addition, since the gas portion is detected when the substrate is replaced, the detection of the gas portion does not affect the exposure operation, and the desired throughput of the exposure apparatus can be maintained. The “gas portion in the liquid” includes not only bubbles in the liquid but also voids in the liquid.
According to a sixth aspect of the present invention, there is provided a device manufacturing method including exposing a substrate by the exposure method of the present invention, developing the exposed substrate, and processing the developed substrate. The Since this device manufacturing method employs the exposure method of the present invention, a device having desired performance can be provided.
According to the present invention, it is possible to confirm that the liquid immersion area is in a desired state using an observation apparatus, and to satisfactorily expose the substrate.
It is a schematic block diagram which shows the exposure apparatus which concerns on 1st Embodiment. It is the top view which looked at the substrate stage and the measurement stage from the upper part. It is an expanded sectional view near the projection optical system tip. It is a figure for demonstrating a mode that a 1st immersion area | region moves between a substrate stage and a measurement stage. It is a flowchart figure which shows an example of an exposure procedure. It is a figure which shows the state which the observation apparatus observes the liquid immersion area | region. It is a figure which shows the exposure apparatus which concerns on 2nd Embodiment. It is a figure which shows the exposure apparatus which concerns on 3rd Embodiment. It is a flowchart figure which shows an example of the observation timing by an observation apparatus. It is a flowchart figure which shows an example of the exposure procedure which concerns on 4th Embodiment. It is a figure which shows the principal part of the exposure apparatus which concerns on 4th Embodiment. It is a figure which shows an example of a deaeration apparatus. It is the schematic which shows the observation apparatus provided with the illumination light source. It is the schematic which shows an example of the illuminating device which illuminates a liquid immersion area | region. It is the schematic which shows an example of the illuminating device which illuminates a liquid immersion area | region. It is the schematic which shows an example of the illuminating device which illuminates a liquid immersion area | region. It is the schematic which shows an example of the illuminating device which illuminates a liquid immersion area | region. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.
FIG. 1 is a schematic block diagram that shows an exposure apparatus EX according to the first embodiment. In FIG. 1, an exposure apparatus EX includes a mask stage MST that can move while supporting a mask M, and a substrate holder PH that holds a substrate P, and a substrate stage that can move while holding the substrate P in the substrate holder PH. Illumination optics that illuminates the exposure stage EL with a PST1 and a measurement stage PST2 that can move independently of the substrate stage PST1 and a mask M supported by the mask stage MST. A system IL, a projection optical system PL that projects an image of the pattern of the mask M illuminated by the exposure light EL onto the substrate P supported by the substrate stage PST1, and a control device CONT that controls the overall operation of the exposure apparatus EX. And. The control device CONT is connected to a display device DY that displays information related to the exposure process.
The exposure apparatus EX of the present embodiment is an immersion exposure apparatus to which an immersion method is applied in order to substantially shorten the exposure wavelength to improve the resolution and substantially widen the depth of focus. Among the plurality of optical elements LS1 to LS7 constituting the PL, the first liquid LQ1 fills the space between the lower surface T1 of the first optical element LS1 closest to the image plane of the projection optical system PL and the substrate P, and the first liquid immersion. A first immersion mechanism 1 that forms the region LR1 is provided. The first liquid immersion mechanism 1 includes a first liquid supply mechanism 10 that supplies a first liquid LQ1 between the lower surface T1 of the first optical element LS1 and the substrate P, and a first liquid supplied by the first liquid supply mechanism 10. And a first liquid recovery mechanism 20 that recovers the liquid LQ1. The operation of the first immersion mechanism 1 is controlled by the control device CONT.
Further, in the vicinity of the image plane side of the projection optical system PL, specifically, in the vicinity of the optical element LS1 at the end of the projection optical system PL on the image plane side, a nozzle member 70 constituting a part of the first liquid immersion mechanism 1 is provided. Is arranged. The nozzle member 70 is an annular member provided so as to surround the periphery of the distal end portion of the projection optical system PL above the substrate P (substrate stage PST).
Further, the exposure apparatus EX fills a space between the first optical element LS1 and the second optical element LS2 close to the image plane of the projection optical system PL next to the first optical element LS1 with the second liquid LQ2 to fill the second liquid immersion. A second immersion mechanism 2 for forming the region LR2 is provided. The second optical element LS2 is disposed above the first optical element LS1, and the upper surface T2 of the first optical element LS1 is disposed so as to face the lower surface T3 of the second optical element LS2. The second liquid immersion mechanism 2 includes a second liquid supply mechanism 30 that supplies the second liquid LQ2 between the first optical element LS1 and the second optical element LS2, and a second liquid supply mechanism 30 that supplies the second liquid LQ2. And a second liquid recovery mechanism 40 that recovers the liquid LQ2. The operation of the second immersion mechanism 2 is controlled by the control device CONT.
The exposure apparatus EX in the present embodiment employs a local liquid immersion method in which the first liquid immersion region LR1 is locally formed in a part on the substrate P. The exposure apparatus EX also locally forms the second immersion region LR2 on a part of the upper surface T2 of the first optical element LS1. The exposure apparatus EX uses the first liquid immersion mechanism 1 to transfer the first optical element LS1 and the substrate P arranged on the image plane side at least while transferring the pattern image of the mask M onto the substrate P. The first liquid LQ1 is filled in between to form the first liquid immersion region LR1, and the second liquid LQ2 is placed between the first optical element LS1 and the second optical element LS2 using the second liquid immersion mechanism 2. Filling and forming the second immersion region LR2.
The measurement stage PST2 is provided with an observation device 60 capable of observing the states of the first liquid immersion area LR1 and the second liquid immersion area LR2. The observation device 60 is provided inside the measurement stage 60.
In the present embodiment, the exposure apparatus EX is a scanning exposure apparatus (so-called so-called exposure apparatus EX) that exposes the pattern formed on the mask M onto the substrate P while synchronously moving the mask M and the substrate P in different directions (reverse directions) in the scanning direction. A case where a scanning stepper) is used will be described as an example. In the following description, the synchronous movement direction (scanning direction) of the mask M and the substrate P in the horizontal plane is the X-axis direction, the direction orthogonal to the X-axis direction in the horizontal plane is the Y-axis direction (non-scanning direction), the X-axis, and A direction perpendicular to the Y-axis direction and coincident with the optical axis AX of the projection optical system PL is defined as a Z-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively. Here, the “substrate” includes a semiconductor wafer coated with a resist, and the “mask” includes a reticle on which a device pattern to be reduced and projected on the substrate is formed.
The illumination optical system IL includes an exposure light source that emits exposure light EL, an optical integrator that equalizes the illuminance of the exposure light EL emitted from the exposure light source, a condenser lens that collects the exposure light EL from the optical integrator, and a relay. A lens system and a field stop for setting an illumination area on the mask M by the exposure light EL are included. A predetermined illumination area on the mask M is illuminated with the exposure light EL having a uniform illuminance distribution by the illumination optical system IL. As the exposure light EL emitted from the exposure light source, for example, far ultraviolet light (DUV light) such as bright lines (g-line, h-line, i-line) and KrF excimer laser light (wavelength 248 nm) emitted from a mercury lamp, Further, vacuum ultraviolet light (VUV light) such as ArF excimer laser light (wavelength 193 nm) and F 2 laser light (wavelength 157 nm) is used. In this embodiment, ArF excimer laser light is used.
In the present embodiment, pure water is used as the first liquid LQ1 supplied from the first liquid supply mechanism 10 and the second liquid LQ2 supplied from the second liquid supply mechanism 30. That is, in the present embodiment, the first liquid LQ1 and the second liquid LQ2 are the same liquid. Pure water can transmit not only ArF excimer laser light but also far ultraviolet light (DUV light) such as bright lines (g-line, h-line, i-line) emitted from mercury lamps and KrF excimer laser light (wavelength 248 nm). It is.
The mask stage MST can move while holding the mask M, can move two-dimensionally in a plane perpendicular to the optical axis AX of the projection optical system PL, that is, in the XY plane, and can be rotated slightly in the θZ direction. The mask stage MST is driven by a mask stage drive mechanism MSTD including a linear motor and the like. The mask stage drive mechanism MSTD is controlled by the control device CONT. A movable mirror 52 is provided on the mask stage MST. A laser interferometer 53 is provided at a position facing the movable mirror 52. The two-dimensional position and rotation angle of the mask M on the mask stage MST are measured in real time by the laser interferometer 53, and the measurement result is output to the control device CONT. The control device CONT drives the mask stage drive mechanism MSTD based on the measurement result of the laser interferometer 53, thereby positioning the mask M supported by the mask stage MST.
The projection optical system PL projects the pattern of the mask M onto the substrate P at a predetermined projection magnification β, and includes a plurality of optical elements LS1 to LS1 including the first optical element LS1 provided at the front end portion on the substrate P side. The plurality of optical elements LS1 to LS7 are supported by a lens barrel PK. In the present embodiment, the projection optical system PL is a reduction system having a projection magnification β of, for example, 1/4, 1/5, or 1/8. Note that the projection optical system PL may be either an equal magnification system or an enlargement system. The projection optical system PL may be any one of a catadioptric system including a refractive element and a reflective element, a refractive system not including a reflective element, and a reflective system not including a refractive element. The exposure light EL emitted from the illumination optical system IL is incident on the projection optical system PL from the object plane side, passes through the plurality of optical elements LS7 to LS1, and then is emitted from the image plane side of the projection optical system PL, and the substrate. Reach on P. Specifically, after passing through each of the plurality of optical elements LS7 to LS3, the exposure light EL passes through a predetermined region on the upper surface T4 of the second optical element LS2, passes through a predetermined region on the lower surface T3, The light enters the two-immersion region LR2. The exposure light EL that has passed through the second immersion region LR2 passes through a predetermined region on the upper surface T2 of the first optical element LS1, then passes through a predetermined region on the lower surface T1, and enters the first immersion region LR1. It reaches on the substrate P.
In the present embodiment, the first optical element LS1 is a non-refractive parallel plane plate capable of transmitting the exposure light EL, and the lower surface T1 and the upper surface T2 of the first optical element LS1 are substantially parallel. On the other hand, the second optical element LS2 has a refractive power (lens action). Note that the first optical element LS1 may have refractive power (lens action).
The substrate stage PST1 has a substrate holder PH that holds the substrate P, and is provided so as to be movable on the base BP on the image plane side of the projection optical system PL. The substrate stage PST is driven by the substrate stage drive mechanism PSTD1. The substrate stage drive mechanism PSTD1 is controlled by the control device CONT. The substrate stage drive mechanism PSTD1 includes, for example, a linear motor and a voice coil motor, and can move the substrate stage PST1 in the X-axis, Y-axis, and Z-axis directions, and in the θX, θY, and θZ directions. It is. Therefore, the substrate stage PST1 can move the substrate P held by the substrate holder PH in each of the X-axis, Y-axis, and Z-axis directions, and the θX, θY, and θZ directions.
A movable mirror 54 is provided on the side surface of the substrate stage PST1. A laser interferometer 55 is provided at a position facing the movable mirror 54. The two-dimensional position and rotation angle of the substrate P on the substrate stage PST1 are measured in real time by the laser interferometer 55, and the measurement result is output to the control device CONT. Based on the measurement result of the laser interferometer 55, the control device CONT drives the substrate stage PST1 via the substrate stage drive mechanism PSTD1 in the two-dimensional coordinate system defined by the laser interferometer 55, thereby causing the substrate stage PST1 to move. The substrate P that is supported is positioned in the X-axis direction and the Y-axis direction.
The exposure apparatus EX has an oblique incidence type focus detection system that detects surface position information on the surface of the substrate P as disclosed in, for example, Japanese Patent Laid-Open No. 8-37149. The focus detection system detects a position (focus position) in the Z-axis direction of the surface of the substrate P with respect to the image plane of the projection optical system PL. Further, by obtaining the focus positions at a plurality of points on the surface of the substrate P, the focus detection system can also obtain the posture of the substrate P in the tilt direction. The control device CONT drives the substrate stage PST1 via the substrate stage drive mechanism PSTD1 based on the detection result of the focus detection system, and the position (focus position) of the substrate P in the Z-axis direction and the position in the θX and θY directions. To adjust the surface (exposure surface) of the substrate P to the image surface formed through the projection optical system PL and the liquid LQ. Further, as disclosed in Japanese translations of PCT publication No. 2000-505958 (corresponding US Pat. No. 5,969,441) or US Pat. Concavity and convexity information) may be measured.
The focus detection system may detect the surface position of the substrate P outside the liquid immersion region LR1 without using the liquid LQ1, or detect the surface position of the substrate P via the liquid LQ1. It may be used in combination.
A concave portion 50 is provided on the substrate stage PST1, and the substrate holder PH is disposed in the concave portion 50. And the upper surface 51 other than the recessed part 50 on the substrate stage PST1 is a flat surface that is substantially the same height (level) as the surface of the substrate P held by the substrate holder PH. Upper surface 51 of substrate stage PST1 has liquid repellency with respect to first liquid LQ1. Since the upper surface 51 that is substantially flush with the surface of the substrate P is provided around the substrate P, the first liquid LQ1 is applied to the image surface side of the projection optical system PL even when the peripheral area of the surface of the substrate P is subjected to immersion exposure. The first immersion region LR1 can be satisfactorily formed by holding. If the first immersion region LR1 can be maintained satisfactorily, there may be a step between the surface of the substrate P held by the substrate holder PH and the upper surface 51.
The measurement stage PST2 is equipped with various measuring instruments that perform measurement related to exposure processing, and is provided on the base BP so as to be movable on the image plane side of the projection optical system PL. Measurement stage PST2 is driven by measurement stage drive mechanism PSTD2. The measurement stage drive mechanism PSTD2 is controlled by the control device CONT. The control device CONT can move the substrate stage PST1 and the measurement stage PST2 independently of each other on the base BP via the stage drive mechanisms PSTD1 and PSTD2, respectively. The measurement stage drive mechanism PSTD2 has the same configuration as the substrate stage drive mechanism PSTD1, and the measurement stage PST2 is measured by the measurement stage drive mechanism PSTD2 in the X-axis, Y-axis, and Z-axis directions, θX, similarly to the substrate stage PST1. , ΘY, and θZ directions. A movable mirror 56 for the laser interferometer 57 is provided on the side surface of the measurement stage PST2. The position and rotation angle of the measurement stage PST2 in the two-dimensional direction are measured in real time by the laser interferometer 57, and the control device CONT controls the position of the measurement stage PST2 based on the measurement result of the laser interferometer 57.
An opening 64K is formed on the measurement stage PST2 disposed on the image plane side of the projection optical system PL, and a transparent member 64 is disposed in the opening 64K. The transparent member 64 is made of, for example, a glass plate. Note that the material of the transparent member 64 can be appropriately selected from fluorite, quartz, and the like depending on the wavelength of light guided to an image sensor described later. The upper surface 65 of the transparent member 64 is a flat surface. Further, the upper surface 58 other than the opening 64K on the measurement stage PST2 is also a flat surface. The upper surface 58 of the measurement stage PST2 and the upper surface 65 of the transparent member 64 disposed in the opening 64K are provided so as to be substantially the same height (level), and the upper surface 58 of the measurement stage PST2 is transparent. The upper surface 65 of the member 64 is included. Note that the upper surface 58 of the measurement stage PST2 and the upper surface 65 of the transparent member 64 are desirably liquid repellent with respect to the liquid LQ.
The upper surface 58 of the measurement stage PST2 including the upper surface 65 of the transparent member 64 is provided at a position aligned with the upper surface 51 of the substrate stage PST1 including the surface of the substrate P. The upper surface 51 of the substrate stage PST1 and the measurement stage PST2 The upper surface 58 is provided so as to have substantially the same height position.
An internal space 66 connected to the opening 64K is formed in the measurement stage PST2. An observation device 60 is arranged in the internal space 66 of the measurement stage PST2. The observation device 60 includes an optical system 61 disposed on the lower side of the transparent member 64, and an imaging element 63 configured by a CCD or the like. The image sensor 63 can acquire an optical image (image) such as a liquid (LQ1, LQ2) or an optical element (LS1, LS2) via the transparent member 64 and the optical system 61. The image sensor 63 converts the acquired image into an electrical signal and outputs the signal (image information) to the control device CONT. Further, the observation device 60 includes an adjustment mechanism 62 that can adjust the focal position of the optical system 61. In addition, the observation device 60 has a field of view through which the entire first immersion region LR1 and second immersion region LR2 can be observed. For example, a charge-coupled device (CCD) can be used as the imaging device 63, but not limited thereto, various devices can be used. As the charge coupled device, a device having high sensitivity to light (wavelength) incident thereon can be appropriately selected.
Note that all of the observation apparatus 60 may be disposed inside the measurement stage PST2, but for example, some of the optical elements constituting the optical system 61, the imaging element 63, and the like are outside the measurement stage PST2. May be arranged. Further, a configuration in which the adjustment mechanism 62 is omitted may be used. Alternatively, the image pickup device 63 may be omitted, and the optical signal may be directly guided to the control device CONT through an optical fiber or a waveguide, and may be processed or photoelectrically converted as it is in the control device. Alternatively, the optical signal may be guided to the display device DY as it is, and the state of the first immersion region LR1 and the second immersion region LR2 may be observed with the display device DY.
FIG. 2 is a plan view of the substrate stage PST1 and the measurement stage PST2 as viewed from above. In FIG. 2, on the upper surface 58 of the measurement stage PST2, as a measuring instrument, in order to define the alignment position of the substrate P with respect to the image of the pattern of the mask M via the projection optical system PL, the projection position of the pattern image and the position of A reference member 300 for measuring the positional relationship (baseline amount) in the XY plane with the detection reference of the substrate alignment system shown in the figure is provided. In the reference member 300, a reference mark PFM and a reference mark MFM are formed in a predetermined positional relationship. The fiducial mark PFM is detected without using the projection optical system PL and the liquids LQ1 and LQ2 by an FIA (Field Image Alignment) type substrate alignment system as disclosed in, for example, Japanese Patent Laid-Open No. 4-65603. The The reference mark MFM is detected via the projection optical system PL and the liquids LQ1 and LQ2 by a VRA (visual reticle alignment) type mask alignment system as disclosed in, for example, Japanese Patent Laid-Open No. 7-176468. The On the upper surface 58, as a measuring instrument, for example, unevenness in illuminance is measured as disclosed in Japanese Patent Laid-Open No. 57-117238, or projection optics as disclosed in Japanese Patent Laid-Open No. 2001-267239. An upper plate 401 constituting a part of the unevenness sensor 400 for measuring the fluctuation amount of the transmittance of the exposure light EL of the system PL, one of the aerial image measurement sensors 500 as disclosed in JP-A-2002-14005. And an upper plate 601 constituting a part of a dose sensor (illuminance sensor) 600 as disclosed in Japanese Patent Laid-Open No. 11-16816. The upper surface of the reference member 300 and the upper surfaces of the upper plates 401, 501, and 601 are substantially flush with the upper surface 58 of the measurement stage PST2 and the upper surface 65 of the transparent member 64. Further, the upper surfaces of the reference member 300 and the upper plates 401, 501, and 601 are also liquid repellent like the upper surface 58 of the measurement stage PST2 and the upper surface 65 of the transparent member 64.
In this embodiment, the measurement stage PST2 is a dedicated stage for performing a measurement process related to the exposure process and does not hold the substrate P. The substrate stage PST1 is a measuring instrument that performs a measurement related to the exposure process. The configuration is not installed. The measurement stage PST2 is disclosed in more detail in, for example, Japanese Patent Application Laid-Open No. 11-135400.
Next, the first liquid immersion mechanism 1 and the second liquid immersion mechanism 2 will be described with reference to FIGS. 1 and 3. FIG. 3 is an enlarged cross-sectional view showing the vicinity of the front end of the image plane side of the projection optical system PL.
The first liquid supply mechanism 10 of the first immersion mechanism 1 is for supplying the first liquid LQ1 to the first space K1 on the image plane side of the first optical element LS1 of the projection optical system PL. 1st liquid supply part 11 which can send out 1 liquid LQ1, and the 1st supply pipe 13 which connects the end part to the 1st liquid supply part 11 are provided. The other end of the first supply pipe 13 is connected to the nozzle member 70. In the present embodiment, the first liquid supply mechanism 10 supplies pure water, and the first liquid supply unit 11 adjusts the temperature of the pure water production apparatus and the supplied first liquid (pure water) LQ1. And a deaerator for reducing gas components in the first liquid LQ1 to be supplied. If the predetermined quality condition is satisfied, the pure water production apparatus (utility) of the factory where the exposure apparatus EX is disposed may be used without providing the pure water production apparatus in the exposure apparatus EX. Similarly, it is not necessary to provide all of the temperature control device and the deaeration device in the exposure apparatus EX, and equipment such as a factory in which the exposure apparatus EX is arranged may be used instead of at least a part of them. .
Further, in the middle of the first supply pipe 13, a flow rate controller called a mass flow controller that controls the amount of liquid per unit time that is sent from the first liquid supply unit 11 and supplied to the image plane side of the projection optical system PL. 16 is provided. Control of the liquid supply amount by the flow rate controller 16 is performed under a command signal of the control device CONT.
The first liquid recovery mechanism 20 of the first liquid immersion mechanism 1 is for recovering the first liquid LQ1 on the image plane side of the projection optical system PL, and is capable of recovering the first liquid LQ1. And a first recovery pipe 23 having one end connected to the first liquid recovery part 21. The other end of the first recovery pipe 23 is connected to the nozzle member 70. The first liquid recovery unit 21 includes, for example, a vacuum system (a suction device) such as a vacuum pump, a gas-liquid separator that separates the recovered first liquid LQ1 and gas, a tank that stores the recovered liquid LQ, and the like. . Note that equipment such as a factory in which the exposure apparatus EX is disposed may be used without providing at least a part of the vacuum system, gas-liquid separator, tank, and the like in the exposure apparatus EX.
A nozzle member 70 that is an annular member is disposed in the vicinity of the image plane side of the projection optical system PL. A gap is provided between the nozzle member 70 and the lens barrel PK of the projection optical system PL, and the nozzle member 70 is supported by a predetermined support mechanism so as to be vibrationally separated from the projection optical system PL. ing. The lower surface 70A of the nozzle member 70 faces the surface of the substrate P (the upper surface 51 of the substrate stage PST1).
The lower surface 70A of the nozzle member 70 is provided with a first supply port 12 that supplies the first liquid LQ1 onto the substrate P. A plurality of first supply ports 12 are provided on the lower surface 70 </ b> A of the nozzle member 70. In addition, an internal flow path 14 that connects the other end of the first supply pipe 13 and the first supply port 12 is formed inside the nozzle member 70. One end of the internal flow path 14 is connected to the other end of the first supply pipe 13, and the other end of the internal flow path 14 branches in the middle so as to be connected to each of the plurality of first supply ports 12. is doing.
Further, a first recovery port 22 for recovering the first liquid LQ1 on the substrate P is provided on the lower surface 70A of the nozzle member 70. In the present embodiment, the first recovery port 22 has an annular shape outside the first supply port 12 with respect to the optical axis AX of the projection optical system PL so as to surround the first supply port 12 on the lower surface 70A of the nozzle member 70. Is provided. In addition, an internal flow path 24 that connects the other end of the first recovery pipe 23 and the first recovery port 22 is formed inside the nozzle member 70. The internal flow path 24 includes an annular flow path 24K formed according to the annular first recovery port 22, and a manifold flow path 24M that connects a part of the annular flow path 24K and the other end of the first recovery pipe 23. And have. In the present embodiment, the first recovery port 22 is provided with a porous body 22P. The configuration of the nozzle member 70 (the position of the supply port, the position of the recovery port, etc.) is not limited to that described above, and various types of nozzle members can be used, and an example thereof is US Patent Publication No. 2004/0165159. It is disclosed in the publication.
The operations of the first liquid supply unit 11 and the first liquid recovery unit 21 are controlled by the control device CONT. When forming the first immersion region LR1 of the first liquid LQ1 in the first space K1, the control device CONT sends out the first liquid LQ1 from the first liquid supply unit 11, and supplies the first supply pipe 13 and the nozzle member. The first liquid LQ1 is supplied onto the substrate P from the first supply port 12 provided above the substrate P via the internal flow path 14 of 70. Further, the first liquid LQ1 in the first space K1 is recovered from the first recovery port 22 and recovered by the first liquid recovery unit 21 via the internal flow path 24 of the nozzle member 70 and the first recovery pipe 23. .
In the present embodiment, during the exposure of the substrate P, the exposure apparatus EX has a first part larger than the projection region AR and smaller than the substrate P on a part of the substrate P including the projection region AR of the projection optical system PL. A local liquid immersion method in which the liquid immersion region LR1 is locally formed is employed. Here, the lower surface 70A of the nozzle member 70 and the lower surface T1 of the first optical element LS1 are substantially flat surfaces, and the lower surface 70A of the nozzle member 70 and the lower surface T1 of the first optical element LS1 are substantially flush with each other. ing. Thereby, the first immersion region LR1 can be favorably formed within a desired range. Further, the lower surface T1 of the first optical element LS1 that contacts the first liquid LQ1 of the first immersion region LR1 and the lower surface 70A of the nozzle member 70 that contacts the first liquid LQ1 of the first immersion region LR1 are: It has lyophilicity with respect to the first liquid LQ1.
The second liquid supply mechanism 30 of the second immersion mechanism 2 is for supplying the second liquid LQ2 to the second space K2 between the second optical element LS2 and the first optical element LS1 of the projection optical system PL. The second liquid supply unit 31 that can deliver the second liquid LQ2 and the second supply pipe 33 that connects one end of the second liquid supply unit 31 to the second liquid supply unit 31 are provided. The second liquid supply unit 31 has substantially the same configuration as the first liquid supply unit 11. That is, the second liquid supply unit 31 is for reducing the gas components in the pure water production apparatus, the temperature adjusting apparatus for adjusting the temperature of the supplied second liquid (pure water) LQ2, and the supplied second liquid LQ2. It is equipped with a deaeration device. The other end of the second supply pipe 33 is connected to one end of a supply flow path 34 formed inside the lens barrel PK. The other end of the supply flow path 34 is connected to a supply member 35 disposed inside (internal space) the lens barrel PK. The supply member 35 is formed with an internal flow path through which the second liquid LQ2 flows. The supply member 35 is connected to the internal flow path at a predetermined position of the supply member 35 and supplies the second liquid LQ2 to the second space K2. A second supply port 32 is formed. That is, for the second space K2, the temperature-adjusted and degassed second liquid LQ2 is supplied from the second supply port 32. It should be noted that, without providing all of the pure water production apparatus, the temperature control apparatus, the deaeration apparatus, etc. in the exposure apparatus EX, it is possible to use facilities such as an improvement in which the exposure apparatus EX is installed instead of at least a part of them. Good.
A flow rate controller (mass flow controller) 36 that controls the amount of liquid per unit time that is sent from the second liquid supply unit 31 and supplied to the second space K2 is provided in the middle of the second supply pipe 33. ing. Control of the liquid supply amount by the flow rate controller 36 is performed under a command signal of the control device CONT.
The second liquid recovery mechanism 40 of the second immersion mechanism 2 is for recovering the second liquid LQ2 in the second space K2 between the second optical element LS2 and the first optical element LS1 of the projection optical system PL. The second liquid recovery part 41 capable of recovering the second liquid LQ2 and the second recovery pipe 43 connected to one end of the second liquid recovery part 41 are provided. The second liquid recovery unit 41 has substantially the same configuration as the first liquid recovery unit 21. The other end of the second recovery tube 43 is connected to one end of a recovery channel 44 formed inside the lens barrel PK. The other end of the recovery channel 44 is connected to a recovery member 45 disposed inside (internal space) the lens barrel PK. The recovery member 45 is formed with an internal flow path through which the second liquid LQ2 flows, and is connected to the internal flow path at a predetermined position of the recovery member 45 to recover the second liquid LQ2 in the second space K2. A recovery port 42 is provided. In the present embodiment, the recovery member 45 is an annular member surrounding the second liquid immersion region LR2, and a plurality of second recovery ports 42 are provided on the surface of the recovery member 45 facing the second liquid immersion region LR2. Yes. Note that the configuration of the second immersion mechanism 2 is not limited to the above-described configuration, and various configurations may be adopted as long as the optical path between the first optical element LS1 and the second optical element LS2 can be filled with the second liquid LQ2. can do.
The operations of the second liquid supply unit 31 and the second liquid recovery unit 41 are controlled by the control device CONT. When forming the second immersion region LR2 of the second liquid LQ2 in the second space K2, the control device CONT sends the second liquid LQ2 from the second liquid supply unit 31, and supplies the second supply pipe 33, the supply flow path. 34, the second liquid LQ2 is supplied from the second supply port 32 to the second space K2 via the internal flow path of the supply member 35. In addition, the second liquid LQ2 in the second space K2 is recovered from the second recovery port 42, and the second liquid recovery unit 41 via the internal flow path of the recovery member 45, the recovery flow path 44, and the second recovery pipe 43. To be recovered.
In addition, as a deaeration apparatus of the 1st liquid supply part 11 and the 2nd liquid supply part 31, the apparatus currently disclosed by international publication 2004/053950 can be applied, for example about the structure. 12 will be described in detail later.
In the present embodiment, the exposure apparatus EX includes the second immersion area AR of the second liquid LQ2 only in a part of the upper surface T2 of the first optical element LS1 including the area AR ′ through which the exposure light EL passes. 'Form locally.
In the present embodiment, the first space K1 on the lower surface T1 side of the first optical element LS1 and the second space K2 between the first optical element LS1 and the second optical element LS2 are independent spaces. The control device CONT supplies and recovers the first liquid LQ1 to the first space K1 by the first liquid immersion mechanism 1, and supplies and recovers the second liquid LQ2 to the second space K2 by the second liquid immersion mechanism 2. The operation can be performed independently of each other, and the liquid (LQ1, LQ2) does not enter or exit from one of the first space K1 and the second space K2.
Then, by filling the respective optical path spaces of the first space K1 on the lower surface T1 side and the second space K2 on the upper surface T2 side of the first optical element LS1 with the first liquid LQ1 and the second liquid LQ2, the second optical The reflection loss on the lower surface T3 of the element LS2 and the upper surface T2 of the first optical element LS1 is reduced, and the substrate P can be exposed well with a large image-side numerical aperture secured.
In the present embodiment, the first optical element LS1 is easily attachable / detachable (replaceable) with respect to the lens barrel PK. Therefore, when the first optical element LS1 is contaminated, By exchanging with the clean first optical element LS1, it is possible to prevent deterioration of exposure accuracy and measurement accuracy via the projection optical system PL due to contamination of the optical element.
As shown in FIG. 4, the first immersion region LR1 formed below the first optical element LS1 of the projection optical system PL can be moved between the substrate stage PST1 and the measurement stage PST2. ing. When moving the first immersion region LR1, the control unit CONT uses the stage drive mechanisms PSTD1 and PSTD2 to bring the substrate stage PST1 and the measurement stage PST2 into contact with each other or approach each other, and the measurement stage PST1 and the measurement stage PST2. PST2 is moved together in the XY direction, and the first immersion region LR1 is moved between the upper surface of the substrate stage PST1 and the upper surface of the measurement stage PST2. Thus, the first space K1 (optical path space) on the image plane side of the projection optical system PL is set to the first while suppressing the outflow of the first liquid LQ1 from the gap (gap) between the substrate stage PST1 and the measurement stage PST2. The first immersion region LR1 can be moved between the substrate stage PST1 and the measurement stage PST2 while being filled with the liquid LQ1.
Accordingly, when the substrate stage PST1 moves from below the projection optical system PL, for example, for exchanging the substrate P, the first immersion region LR1 moves from the substrate stay PST1 onto the measurement stage PST2, and is projected. The first liquid LQ1 is held between the first optical element LS1 of the optical system PL and the upper surface of the measurement stage PST2, and the observation device 60, the reference member 300, the unevenness sensor 400, the aerial image measurement sensor 500, and the dose sensor 600 are The operation using at least one is executed through the first liquid LQ1. In this case, the result of the operation is reflected in the subsequent exposure operation or the like. Further, when the substrate stage PST1 moves below the projection optical system PL, the first immersion region LR1 moves from the measurement stage PST2 onto the substrate stage PST1, and the first optical element LS1 of the projection optical system PL The first liquid LQ1 is held between the upper surface (including the surface of the substrate P) of the substrate stage PST1, and the exposure operation of the substrate P is performed.
Next, a procedure for exposing the substrate P using the exposure apparatus EX having the above-described configuration will be described with reference to the flowchart of FIG. 5 and FIG.
First, the control device CONT drives each of the first liquid immersion mechanism 1 and the second liquid immersion mechanism 2 in a state where the projection optical system PL and the transparent member 64 on the measurement stage PST2 are opposed to each other. Each of the immersion region LR1 and the second immersion region LR2 is formed (step SA1). Thereby, as shown in FIG. 6, the first immersion region LR <b> 1 is formed on the upper surface 58 of the measurement stage PST <b> 2 including the upper surface 65 of the transparent member 64.
The control device CONT uses the observation device 60 to observe the state of the first liquid immersion region LR1 formed on the transparent member 64 (Step SA2). The observation device 60 observes the state of the first immersion region LR1 on the upper surface 65 of the transparent member 64 through the transparent member 64. Note that when the observation device 60 is observing the state of the first immersion region LR1, the measurement stage PST2 is substantially stationary. The optical system 61 of the observation device 60 is disposed in the internal space 66 below the transparent member 64, and the imaging device 63 is configured to store the first liquid LQ 1 that forms the first liquid immersion region LR 1 on the transparent member 64. An image is acquired through the transparent member 64 and the optical system 61. When observing the state of the first immersion region LR1 using the observation device 60, the control device CONT uses the adjustment mechanism 62 to move the focal position of the optical system 61 to a position in the Z-axis direction of the first immersion region LR1. Match. Therefore, the image sensor 63 can acquire an image of the first liquid LQ1 forming the first liquid immersion area LR1 on the transparent member 64 in a good manner. Further, since the observation device 60 has a field of view larger than that of the first liquid immersion region LR1, it is possible to collectively acquire images of the first liquid LQ1 that forms the first liquid immersion region LR1.
Note that the size of the first immersion region LR1 may vary depending on the amount of liquid supplied and the amount of liquid recovered by the first immersion mechanism 1, but the observation device 60 is expected to have the largest first immersion region. LR1 has a field of view that can be observed.
Image information regarding the first immersion region LR1 acquired by the imaging element 63 is output to the control device CONT (step SA3). The control device CONT displays an image of the first liquid LQ forming the first liquid immersion area LR1 on the display device DY based on the signal (image information) output from the imaging element 63.
Next, the control device CONT uses the observation device 60 to observe the state of the second immersion region LR2 (step SA4). The observation device 60 observes the second liquid immersion area LR2 via the first liquid LQ1 in the first liquid immersion area LR1 and the first optical element LS1. Even when the observation device 60 is observing the state of the second immersion region LR2, the measurement stage PST2 is almost stationary. When observing the state of the second immersion region LR2 using the observation device 60, the control device CONT uses the adjustment mechanism 62 to set the focal position of the optical system 61 to the position of the second immersion region LR2 in the Z-axis direction. Match. Therefore, the image sensor 63 can acquire an image of the second liquid LQ2 forming the second liquid immersion region LR2 satisfactorily. Further, since the observation device 60 has a field of view larger than that of the second liquid immersion region LR2, it is possible to collectively acquire images of the second liquid LQ2 that forms the second liquid immersion region LR2.
Image information regarding the second immersion region LR2 acquired by the imaging element 63 is output to the control device CONT (step SA5). The control device CONT displays an image of the second liquid LQ2 forming the second liquid immersion area LR2 on the display device DY based on the signal (image information) output from the imaging element 63.
Here, after observing the state of the first immersion region LR1, the state of the second immersion region LR2 is observed. However, after observing the state of the second immersion region LR2, the first immersion region LR2 is observed. You may make it observe the state of LR1.
In step SA3 and step SA5, the control device CONT performs arithmetic processing (image processing) on the signal output from the image sensor 63, and the first and second liquid immersion regions LR1 and LR2 are desired based on the processing result. It is determined whether or not it is in a state (step SA6). In particular, the control device CONT determines whether or not particles or gas portions (such as air bubbles or bubbles) are present in the liquid (LQ1, LQ2). For example, the control device CONT determines whether the output from the image sensor 63 is bright or dark for each pixel, regards the isolated pixel or group of pixels as the presence of bubbles in the liquid, and determines the bubbles from the number of such pixels or pixel groups. The number and amount of can be determined. Alternatively, the control device CONT stores image data of a plurality of liquid samples with known number and amount of bubbles in the memory of the control device CONT, and determines the number and amount of bubbles in comparison with the data. Good. In this case, the image data may associate the average area or average number of bright or dark parts of the pixel with the number or amount of bubbles. The image data and the reference data may be stored in the memory of the control device, or may be stored in a memory provided separately in the exposure apparatus. Similarly, the position and size of the void in the liquid can be detected.
For example, immediately after the first immersion mechanism 1 starts forming the first immersion region LR1 (immediately after the supply of the first liquid LQ1 is started), the first immersion region LR1 sufficiently covers the projection region AR. There is a high possibility that an uncovered state (liquid running out state) occurs, or a problem such as bubbles mixed in the first liquid LQ1 occurs. Further, not only immediately after the operation of forming the first liquid immersion area LR1 is started, the state of the first liquid immersion area LR1 varies depending on the operation state of the first liquid immersion mechanism 1, and the above-described problem occurs. there's a possibility that. When exposure processing and measurement processing are performed through the first immersion region LR1 in a state where such a problem has occurred, good exposure accuracy and measurement accuracy cannot be obtained. In the present embodiment, by observing the state of the first liquid immersion region LR1 using the observation device 60, it is possible to grasp whether or not a defect has occurred in the first liquid immersion region LR1. Similarly, in the second liquid immersion area LR2, there is a possibility that a liquid out-of-liquid condition occurs or bubbles are mixed in. However, the state of the second liquid immersion area LR2 is changed using the observation device 60. By observing, it is possible to grasp whether or not a defect has occurred in the second immersion region LR2. Note that the observation apparatus 60 of the present embodiment can observe (detect) bubbles having a diameter of 0.1 mm or more, for example, but the observation (detection) capability of the observation apparatus 60 is formed on the substrate P by the exposure apparatus EX. What is necessary is just to determine according to the line | wire width of a pattern, etc. For example, you may enable it to observe the bubble of 0.01 mm or more.
When determining that the first and second liquid immersion regions LR1 and LR2 are in the desired state, the control device CONT performs a measurement process using each measuring instrument mounted on the measurement stage PST2 (step SA7). That is, the control device CONT moves the measurement stage PST2 in the XY directions, and moves the first immersion region LR1 from the transparent member 64 to any one of the reference member 300, the upper plate 401, the upper plate 501, and the upper plate 601. Move up one. For example, when the first immersion area LR1 is moved from the transparent member 64 to the upper plate 401 of the illuminance unevenness sensor 400, the control device CONT includes the projection optical system PL, the first liquid LQ1 in the first immersion area LR1, and The exposure light EL is irradiated onto the upper plate 401 via the second liquid LQ2 in the second immersion region LR2, and the illuminance unevenness of the exposure light EL is measured using the illuminance unevenness sensor 400. Similarly, the control device CONT sequentially moves the first immersion region LR1 on the reference member 300, the upper plate 500, and the upper plate 600, and the reference member 300, the aerial image measurement sensor 500, and the irradiation amount sensor. Measurement processing using each of 600 is performed. And based on the measurement result using each said measuring device, the control apparatus CONT performs the calibration process of the projection optical system PL, etc. suitably.
In parallel with various measurement operations in step SA7 or before and after the measurement operation, the reference mark PFM on the reference member 300 is detected by a substrate alignment system (not shown) to determine the baseline amount.
On the other hand, if it is determined that at least one of the first liquid immersion area LR1 and the second liquid immersion area LR2 is not in the desired state, the control device CONT eliminates the above-described problems (liquid running out, bubble mixing, etc.). In order to eliminate the above-mentioned problems, the liquid supply to the space in which the liquid immersion area determined to be not in the desired state is stopped, the liquid is recovered, and the liquid is discharged again. Supply and take steps to recreate the immersion area. Alternatively, appropriate measures such as changing the operating state of the first and second liquid immersion mechanisms 1 and 2 are taken in order to eliminate the above-described problems (step SA8). Here, the change in the operating state of the first and second liquid immersion mechanisms 1 and 2 is, for example, per unit time by the first and second liquid supply mechanisms 10 and 30 of the first and second liquid immersion mechanisms 1 and 2. Change of the liquid supply amount, adjustment of a deaeration device provided in the first and second liquid supply mechanisms 10 and 30 and the like. Then, the state of the first and second liquid immersion regions LR1 and LR2 is observed again using the observation device 60 (steps SA2 and SA4), and after confirming that the above-described problems have been resolved, measurement processing (step SA7). I do.
After the measurement process using the measurement stage PST2 is completed, as described with reference to FIG. 4, the control device CONT uses the first immersion region LR1 of the first liquid LQ1 formed on the measurement stage PST2. Then, the substrate P is moved onto the substrate stage PST1 supporting the substrate P. Then, after moving the first liquid immersion area LR1 onto the substrate stage PST1, the control device CONT performs the projection optical system PL, the second liquid LQ2 in the second liquid immersion area LR2, and the first liquid in the first liquid immersion area LR1. The substrate P is exposed by irradiating the substrate P with the exposure light EL through the liquid LQ1 (step SA9).
Note that, based on the images of the first and second liquid immersion regions LR1 and LR2 displayed on the display device DY, for example, the operator determines whether the first and second liquid immersion regions LR1 and LR2 are in a desired state. You may make it judge. In this case, an operator or the like instructs the control device CONT to perform the next operation.
As described above, since the observation device 60 for observing the state of the first and second liquid immersion regions LR1 and LR2 is provided, the first and second liquids formed based on the observation result of the observation device 60 are provided. It can be confirmed whether or not the immersion regions LR1 and LR2 are in a desired state. Then, after determining that the formed first and second immersion regions LR1 and LR2 are in a desired state based on the observation result of the observation device 60, the substrate P is exposed to perform first and second exposure. The substrate P can be satisfactorily exposed through the first and second liquids LQ1, LQ2 in the liquid immersion regions LR1, LR2. On the other hand, when it is determined that the first and second immersion regions LR1 and LR2 are not in a desired state based on the observation result of the observation device 60, such a state is not desired. When exposure processing and measurement processing are performed via the first and second liquid immersion regions LR1 and LR2, good exposure accuracy and measurement accuracy cannot be obtained. Therefore, the control device CONT performs appropriate measures for bringing the first and second liquid immersion regions LR1 and LR2 into a desired state, and confirms that the first and second liquid immersion regions LR1 and LR2 are in a desired state. After the confirmation, the substrate P can be satisfactorily exposed by exposing the substrate P through the first and second liquids LQ1, LQ2 in the first and second immersion regions LR1, LR2.
In addition, the first immersion region LR1 is formed between the projection optical system PL and the transparent member 64 disposed on the image plane side of the projection optical system PL, and the observation device 60 passes the first liquid through the transparent member 64. Since the immersion region LR1 is observed, the state of the first immersion region LR1 can be favorably observed.
FIG. 7 is a diagram showing a second embodiment. In the following description, the same or equivalent components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is simplified or omitted.
As shown in FIG. 7, when observing the second immersion region LR2 using the observation device 60, the control device CONT drives the second immersion mechanism 2 without forming the first immersion region LR1. Thus, only the second immersion region LR2 may be formed. Even in this case, the observation device 60 can observe the second immersion region LR2 of the second space K2 via the first optical element LS1.
In addition, the observation of the first immersion region LR1 is performed in a state where the second immersion region LR2 is formed or a state where the second immersion region LR2 is not formed before or after the observation of the second immersion region LR2. .
FIG. 8 is a diagram showing a third embodiment. In FIG. 8, the observation device 60 is provided in an internal space 66 ′ of the substrate stage PST1. An opening 64K ′ is formed in a part of the upper surface 51 of the substrate stage PST1 so as to be connected to the internal space 66 ′, and the transparent member 64 is disposed in the opening 64K ′. Thus, the transparent member 64 and the observation device 60 may be provided on the substrate stage PST1 that can move while holding the substrate P.
In each of the above-described embodiments, the observation device 60 has a larger field of view than the first and second immersion regions LR1 and LR2, but is smaller than the first and second immersion regions LR1 and LR2. You may have a visual field. In that case, the measurement stage PST2 (or the substrate stage PST1) on which the observation device 60 is mounted is moved in the XY direction with respect to the projection optical system PL, that is, the first and second immersion regions LR1 and LR2 and the observation device. By observing the 60 visual fields while relatively moving, the entire areas of the first and second liquid immersion regions LR1 and LR2 can be favorably observed.
In addition, a zoom optical system is mounted on the observation device 60 to change the size of the observation field between when observing the immersion region LR1 and when observing the immersion region LR2, or to enlarge a part of the immersion region. You may make it observe.
In the above-described embodiment, based on the image information acquired by the image sensor 63 of the observation device 60, the control device CONT causes the display device DY to display the images of the first and second liquid immersion regions LR1, LR2. However, the observation device 60 may have an image processing function and a display device DY.
In the above-described embodiment, the control device CONT performs the observation operation using the observation device 60 when the first immersion mechanisms 1 and 2 form the first immersion regions LR1 and LR2. However, the observation operation may be executed every predetermined time interval or every predetermined number of processed substrates.
Further, during the exchange of the substrate P (for example, exchange of the exposed substrate and the unexposed substrate), the liquid LQ1 is held between the first optical element LS1 of the projection optical system PL and the measurement stage PST2. An observation operation can also be performed. In this case, the observation operation by the observation device 60 can be executed every time the substrate P is replaced, but the observation operation may be executed every predetermined number of processed substrates. FIG. 9 shows an example of the timing of observation by the observation device 60, and shows the procedure for executing the observation operation by the observation device 60 for each exposure process of four substrates. FIG. 9 shows a processing procedure subsequent to the exposure in step SA9 (exposure of the first substrate) described in the flowchart of FIG.
After the exposure processing of the first substrate in step SA9, the baseline amount is measured using the reference member 300 (step SA10). Next, exposure processing of the second substrate is executed (step SA11), and thereafter, measurement of the amount of variation in transmittance using the unevenness sensor 400 is executed (step A12). Next, exposure processing of the third substrate is executed (step SA13), and then image plane position measurement using the aerial image measurement sensor 500 is executed (step SA14). Next, an exposure process for the fourth substrate is performed (step SA15), and then the observation of the liquid immersion area LR1 by the observation device 60 is performed (step SA16). Next, exposure processing of five substrates is executed (step SA17), and thereafter steps SA10 to SA17 are repeatedly performed. Note that the flowchart of FIG. 9 is merely an example, and the order of each operation using the observation device 60, the reference member 300, and the sensors 400 and 500 can be appropriately changed, and the execution frequency of each operation is also determined as necessary. can do.
Note that the measurement members and measurement devices mounted on the measurement stage PST2 are not limited to those described above, and various measurement members and measurement devices may be mounted as necessary. For example, the wavefront aberration measuring apparatus disclosed in International Publication No. 99/60361 pamphlet (corresponding US application 09 / 714,183), Japanese Patent Application Laid-Open No. 2002-71514, US Patent No. 6650399, etc. The reflection part disclosed in Japanese Patent Laid-Open No. 62-183522 may be mounted on the measurement stage PST2.
In the above-described embodiment, the substrate stage PST1 and the measurement stage are used to move the first immersion region LR1 from one of the substrate stage PST1 and the measurement stage PST2 before and after the substrate exchange operation of the substrate stage PST1. Although PST2 is contacted or approached, the two stages may be contacted or approached as necessary during other operations. For example, an alignment process for detecting a plurality of alignment marks on the substrate P is executed before the exposure of the substrate P is started. During the alignment process, a part of the first immersion region LR1 is the upper surface of the substrate stage PST1. If there is a risk of detachment from 51, the two stages may be brought into contact or approached to maintain the first immersion region LR1. Further, when there is a possibility that a part of the first liquid immersion area LR1 is detached from the upper surface 51 of the substrate stage PST1 during the exposure of the substrate P, the two stages are brought into contact with each other in order to maintain the first liquid immersion area LR1. Or you may make it approach. By doing in this way, even if the area of the upper surface 51 of the substrate stage PST1 is small, the first immersion region LR1 can be maintained.
Although not clearly shown in the flowchart of FIG. 9, the movement of the first immersion region LR1 from one stage to the other stage is performed between the steps, and further, step SA10, In parallel with the operations in SA12, SA14, and SA16, an exchange operation between the exposed substrate and the next exposed substrate is performed using the substrate stage PST1.
Further, it is not necessary to observe the first liquid immersion area LR1 and the second liquid immersion area LR2 each time an observation operation using the observation apparatus 60 is performed, and either one may be observed.
A fourth embodiment will be described. In the above-described embodiment, the control device CONT determines whether or not the liquid immersion region is in a desired state based on the observation result of the observation device 60 (step SA6 in FIG. 5), and the liquid immersion region is in the desired state. However, in this embodiment, there are gas portions such as bubbles in the liquid forming the liquid immersion area, although various measures are taken to solve the problem (step SA8 in FIG. 5). In this case, the control device CONT supplies the degassed liquid LQ for a predetermined time as a treatment for reducing or eliminating the gas portion. That is, when the control device CONT determines that there is a gas portion in the second liquid LQ2 that forms the second immersion region LR2 based on the observation result of the observation device 60 mounted on the measurement stage PST2, for example, The vaporized second liquid LQ2 is supplied to the second space K2 between the first optical element LS1 and the second optical element LS2 for a predetermined time, and in accordance with the supply amount of the degassed second liquid LQ2. The second liquid immersion mechanism 2 is controlled so as to collect a predetermined amount of the second liquid LQ2 from the two spaces K2. As described above, since the second liquid supply unit 31 of the second liquid immersion mechanism 2 includes the deaeration device for reducing the gas component in the second liquid LQ2, the control device CONT has the second liquid. The second liquid LQ2 is sufficiently deaerated using a deaeration device provided in the supply unit 31, and then the second liquid immersion mechanism 2 is controlled to remove the degassed second liquid LQ2 from the first optical element LS1. And the second space K2 between the second optical element LS2 and the second optical element LS2. Then, by supplying the sufficiently degassed second liquid LQ2 to the second space K2 for a predetermined time, the gas portion (bubbles) in the second liquid LQ2 forming the second immersion region LR2 is changed to the second. It can be dissolved or reduced or eliminated in the liquid LQ2.
FIG. 10 is a flowchart for explaining an example of an operation of supplying the degassed second liquid LQ2 for a predetermined time. Here, a case where the observation operation by the observation device 60 is executed when the second liquid LQ2 is replaced will be described as an example. The exchange of the second liquid LQ2 means that the second liquid LQ2 is filled with the second liquid LQ2 in the second space K2 between the first optical element LS1 and the second optical element LS2. The supply operation of the second liquid LQ2 to the space K2 and the recovery operation of the second liquid LQ2 in the second space K2 are performed in parallel, and the second liquid LQ2 previously filled in the second space K2 is removed from the second space K2. The operation is to collect the second fresh liquid LQ2 adjusted to a predetermined temperature and supplied to the second space K2.
In the present embodiment, it is assumed that the replacement operation of the second liquid LQ2 in the second liquid immersion region LR2 is performed for each lot of substrates P (every predetermined number of substrates processed). During exposure of the substrate P, the second liquid LQ2 is filled in the second space K2 between the first optical element LS1 and the second optical element LS2, but the second liquid LQ2 by the second immersion mechanism 2 is filled. The supply operation and the recovery operation are not performed. By doing this, during the exposure of the substrate P, it is possible to prevent the occurrence of vibration due to the liquid supply operation and the recovery operation by the second immersion mechanism 2. Then, by performing the replacement operation of the second liquid LQ2 in the second immersion region LR2 for each lot of substrates P (every predetermined number of processed substrates), the second space K2 can be filled with the second liquid LQ2 having a desired temperature. it can.
Further, when the second liquid LQ2 in the second immersion region LR2 is replaced, the second space K2 is always filled with the second liquid LQ2 without completely removing the second liquid LQ2 from the second space K2. As described above, it is preferable that the second liquid LQ2 previously filled in the second space K2 and the new second liquid LQ2 are gradually replaced. By doing so, it is possible to suppress the generation of gas parts (bubbles) in the second liquid LQ2 in the second immersion region LR2 due to the replacement of the second liquid LQ2 in the second immersion region LR2. Can do.
After the exposure of the final substrate P of the predetermined lot is completed (step SA18), the control device CONT replaces the second liquid LQ2 in the second liquid immersion area LR2 (step SA19). The control device CONT supplies the second liquid LQ2 to the second space K2 by the second liquid immersion mechanism 2 and the second operation of the second space K2 in order to exchange the second liquid LQ2 in the second liquid immersion region LR2. The recovery operation of the liquid LQ2 is performed in parallel. In addition, after the exposure of the final substrate P in the predetermined lot is completed, the control device CONT moves the measurement stage PST2 to a position facing the projection optical system PL, and the second observation device 60 mounted on the measurement stage PST2 The replacement operation of the second liquid LQ2 is started in a state where the second liquid LQ2 in the liquid immersion region LR2 can be observed.
After the replacement of the second liquid LQ2 in the second liquid immersion area LR2 is completed, the control device CONT uses the observation device 60 to observe the state of the second liquid immersion area LR2. Then, the control device CONT determines whether or not there is a gas portion (bubble) in the second liquid LQ2 in the second immersion region LR2 based on the observation result of the observation device 60 (step SA20).
In Step SA20, when it is determined that there are no bubbles in the second liquid LQ2 forming the second immersion area LR2, the control device CONT performs exposure of the substrate P of the next lot (Step SA21).
On the other hand, when it is determined in step SA20 that there are bubbles in the second liquid LQ2 forming the second immersion region LR2, the control device CONT supplies the degassed second liquid LQ2 for a predetermined time. The second immersion mechanism 2 is controlled (step SA22). Here, in order to reduce or eliminate bubbles, the liquid supply amount per unit time when the second liquid LQ2 is supplied to the second space K2 and the second liquid LQ2 in the second immersion region LR2 are exchanged. The liquid supply amount per unit time may be substantially the same, or the liquid supply per unit time when the second liquid LQ2 is supplied to the second space K2 in order to reduce or eliminate bubbles The amount may be larger than the liquid supply amount per unit time when the second liquid LQ2 in the second immersion region LR2 is replaced.
FIG. 11 is a diagram illustrating a state in which the degassed second liquid LQ2 is supplied to the second space K2 after it is determined that there are bubbles in the second liquid LQ2 forming the second immersion region LR2. It is. As shown in FIG. 11, the control device CONT observes the state of the second immersion region LR2 with the observation device 60, and the second degassed from the second liquid supply unit 31 of the second immersion mechanism 2. The liquid LQ2 is supplied to the second space K2. In FIG. 11, the first immersion region LR1 is not formed. The control device CONT observes the state of the second immersion region LR2 with the observation device 60, and until the size or amount of bubbles in the second liquid LQ2 forming the second immersion region LR2 becomes a predetermined level or less. The second liquid LQ2 sufficiently deaerated from the second liquid supply unit 31 is supplied to the second space K2, and the second liquid LQ2 in the second space K2 is recovered by the second liquid recovery unit 41. By continuing to supply the sufficiently degassed second liquid LQ2 to the second space K2 for a predetermined time, bubbles in the second liquid LQ2 in the second immersion region LR2 can be reduced or eliminated. Further, for example, even when bubbles are attached to the upper surface T2 of the first optical element LS1 and the lower surface T3 of the second optical element LS2, the sufficiently degassed second liquid LQ2 is predetermined in the second space K2. By continuing the supply for a time, the bubbles can be eliminated.
The second liquid LQ2 supplied to the second space K2 in order to reduce or eliminate bubbles is the same as the liquid that fills the second space K2 when the substrate P is exposed. In the present embodiment, the degassing device 38 provided in the second liquid supply unit 31 has a dissolved gas concentration of the second liquid LQ2 supplied to the second space K2 to reduce or eliminate bubbles to 5 ppm or less. Thus, the second liquid LQ2 is degassed. More specifically, the degassing device 38 degass the second liquid LQ2 so as to satisfy at least one condition of a dissolved oxygen concentration of 5 ppm or less, a dissolved carbon dioxide concentration of 5 ppm or less, and a dissolved nitrogen concentration of 5 ppm or less. By reducing the dissolved gas concentration of the second liquid LQ2 supplied to the second space K2 to 5 ppm or less, the bubbles in the second liquid LQ2 forming the second immersion region LR2 are dissolved in the second liquid LQ2 to reduce or Can be eliminated.
FIG. 12 is a cross-sectional view showing a schematic configuration of the deaeration device 38. A cylindrical hollow fiber bundle 172 is accommodated inside the housing 171 via a predetermined space 173. The hollow fiber bundle 172 is formed by bundling a plurality of straw-shaped hollow fiber membranes 174 in parallel. Each hollow fiber membrane 174 is a material having high hydrophobicity and excellent gas permeability (for example, poly 4 methylpentene 1). It is formed with. Vacuum cap members 175 a and 175 b are fixed to both ends of the housing 171, and sealed spaces 176 a and 176 b are formed outside both ends of the housing 171. The vacuum cap members 175a and 175b are provided with deaeration ports 177a and 177b connected to a vacuum pump (not shown). Further, sealing portions 178a and 178b are formed at both ends of the housing 171 so that only both ends of the hollow fiber bundle 172 are connected to the sealed spaces 176a and 176b, and are connected to the deaeration ports 177a and 177b. The inside of each hollow fiber membrane 174 can be decompressed by a vacuum pump. A tube 179 connected to a predetermined liquid supply source is disposed inside the hollow fiber bundle 172. The pipe 179 is provided with a plurality of liquid supply holes 180, and the liquid LQ is supplied from the liquid supply hole 180 to the space 181 surrounded by the sealing portions 178 a and 178 b and the hollow fiber bundle 172. When the supply of the liquid LQ from the liquid supply hole 180 to the space 181 is continued, the liquid LQ flows outward so as to cross the layers of the hollow fiber membranes 174 bundled in parallel, and the liquid LQ flows to the outer surface of the hollow fiber membrane 174 Contact with. As described above, each of the hollow fiber membranes 174 is formed of a material having high hydrophobicity and excellent gas permeability, so that the liquid LQ does not enter the inside of the hollow fiber membranes 174, and between the hollow fiber membranes 174. And move to a space 173 outside the hollow fiber bundle 172. On the other hand, the gas (molecules) dissolved in the liquid LQ moves (is absorbed) to the inside of each hollow fiber membrane 174 because the inside of the hollow fiber membrane 174 is in a reduced pressure state (about 20 Torr). . As described above, the gas component removed (degassed) from the liquid LQ while traversing the layer of the hollow fiber membrane 174 is desorbed from both ends of the hollow fiber bundle 172 through the sealed spaces 176a and 176b as indicated by arrows 183. The air is discharged from the air ports 177a and 177b. The degassed liquid LQ is supplied to the second supply pipe 33 (second space K2) from the liquid outlet 182 provided in the housing 151. In the present embodiment, the second liquid supply unit 31 uses the deaeration device 38 to set the dissolved gas concentration of the second liquid LQ2 supplied to the second space K2 to 5 ppm or less.
Further, since the control device CONT can obtain the size of bubbles and the amount of bubbles in the second liquid LQ2 in the second immersion region LR2 based on the observation result of the observation device 60, the second immersion region LR2 The time for supplying the second liquid LQ2 degassed from the second liquid supply unit 31 may be adjusted according to the size or amount of bubbles in the second liquid LQ2. A timer TM is connected to the control device CONT, and the control device CONT can manage the time by the timer TM. While managing the time, the degassed second liquid LQ2 is supplied to the second space K2. By supplying for a predetermined time, bubbles in the second liquid LQ2 forming the second immersion region LR2 can be reduced or eliminated. Specifically, when the size of the bubbles is large or the amount of bubbles is large, the control device CONT increases the time for supplying the degassed second liquid LQ2, and the size of the bubbles is small. Alternatively, when the amount of bubbles is small, the time for supplying the degassed second liquid LQ2 is shortened. In this way, when the bubble size is large or the amount of bubbles is large, the bubbles can be reliably reduced or eliminated, and when the bubble size is small or the amount of bubbles is small. Can eliminate waste such as continuing to supply the degassed second liquid LQ2 despite the reduction or disappearance of the bubbles.
Further, the control device CONT supplies the second liquid LQ2 deaerated from the second liquid supply unit 31 according to the size or amount of bubbles in the second liquid LQ2 in the second immersion region LR2. The liquid supply amount per unit time can also be adjusted. For example, when the size of bubbles is large or the amount of bubbles is large, the control device CONT increases the amount of liquid supplied per unit time when supplying the degassed second liquid LQ2, When the size is small or the amount of bubbles is small, the liquid supply amount per unit time when the degassed second liquid LQ2 is supplied is decreased.
Then, after supplying the degassed second liquid LQ2 for a predetermined time, the size or amount of bubbles in the second liquid LQ2 forming the second immersion region LR2 is determined based on the observation result of the observation device 60. After confirming that the level is below the level, exposure of the substrate P of the next lot is started.
In the present embodiment, the control device CONT supplies the degassed second liquid LQ2 to the second space K2 for a predetermined time while observing the state of the second immersion region LR2 with the observation device 60. While the degassed second liquid LQ2 is supplied to the second space K2, the observation device 60 may not always be used to observe the state of the second immersion region LR2. For example, at the first time point, the state of the second immersion region LR2 is observed using the observation device 60, and the second liquid LQ2 that forms the second immersion region LR2 is formed based on the observation result of the observation device 60. The controller CONT may supply the second liquid LQ2 deaerated from the second liquid supply unit 31 for a predetermined time without performing the observation operation of the observation device 60 after determining that there is a bubble in . Then, after a predetermined time has elapsed, at the second time point, by using the observation device 60, it is confirmed whether or not the bubbles in the second liquid LQ2 in the second immersion region LR2 have been reduced or eliminated, thereby controlling the control device CONT. Can determine whether to expose the substrate of the next lot or to continue the supply of the degassed second liquid LQ2. Even in this case, the control device CONT can obtain the size or amount of the bubbles in the second immersion region LR2 based on the observation result of the observation device 60 at the first time point. The supply time for supplying the degassed second liquid LQ2 can be adjusted according to the length or amount. When adjusting the supply time of the degassed second liquid LQ2, the control device CONT can adjust the supply time while monitoring the timer TM.
In this embodiment, the observation device 60 observes the state of the second immersion region LR2 after the replacement of the second liquid LQ2 in the second immersion region LR2 is completed. The state of the second immersion region LR2 may be observed by the observation device 60 while exchanging the second liquid LQ2 in the region LR2.
As shown in FIG. 11, when the observation device 60 is provided on the measurement stage PST2, the observation operation of the observation device 60 and the replacement operation of the substrate P on the substrate stage PST1 (final substrate of a predetermined lot) And the replacement operation with the substrate of the next lot) can be performed in parallel. On the other hand, as described in the third embodiment, the observation device 60 may be provided on the substrate stage PST1. In this case, the exchange operation of the substrate P on the substrate stage PST1 can be performed before or after the observation operation of the observation apparatus 60. In FIG. 11, when the state of the second immersion region LR2 is observed using the observation device 60, the first immersion region LR1 is not formed, but the first immersion region LR1 is formed. Also good. In this case, the observation device 60 observes the second immersion region LR2 via the first liquid LQ1 in the first immersion region LR1. On the other hand, as shown in FIG. 11, when the state of the second immersion region LR2 is observed using the observation device 60, the second immersion region LR2 is formed by not forming the first immersion region LR1. The presence or absence of bubbles in the second liquid LQ2 can be observed with higher accuracy.
In the present embodiment, the replacement operation of the second liquid LQ2 in the second immersion region LR2 is performed for each lot of the substrate P (that is, for each replacement of the mask M with respect to the mask stage MST), but at predetermined time intervals. Alternatively, it may be performed every predetermined number of processed substrates.
In the present embodiment, the observation operation by the observation device 60 is performed every time the second liquid LQ2 in the second liquid immersion region LR2 is replaced, but other than when the second liquid LQ2 in the second liquid immersion region LR2 is replaced. You may make it carry out at timing. For example, when the second liquid LQ2 is supplied to the second space K2 in a state where there is no second liquid LQ2, the observation by the observation device 60 may be performed. Alternatively, even during one lot, when the substrate P on the substrate stage PST1 is being exchanged, the projection optical system PL and the measurement stage PST2 face each other, so the observation device 60 is provided on the measurement stage PST2. In the case of the configuration, the second immersion region LR2 can be observed when replacing the substrate in the middle of the lot. When it is determined that there is a bubble in the second liquid LQ2 forming the second immersion region LR2 based on the observation result of the observation device 60, the control device CONT controls the substrate P loaded on the substrate stage PST1. In order to reduce or eliminate bubbles in the second immersion region LR2 without performing exposure, the degassed second liquid LQ2 can be supplied to the second space K2 for a predetermined time.
In the present embodiment, the replacement operation of the second liquid LQ2 in the second immersion area LR2 is performed for each lot (or for each predetermined time interval or for each predetermined number of processed substrates). The second immersion mechanism 2 may always perform the operation of supplying the second liquid LQ2 to the second space K2 and the operation of collecting the second liquid LQ2 in the second space K2. In this case, when the state of the second immersion region LR2 (second liquid LQ2) is observed during a non-exposure operation such as during the exchange of the substrate P and it is determined that there are bubbles in the second liquid LQ2, the control device CONT Without starting the exposure of the next substrate P, the supply operation and the recovery operation of the degassed second liquid LQ2 are performed to reduce or eliminate the bubbles in the second liquid LQ2. At this time, the liquid supply amount per unit time when supplying the second liquid LQ2 deaerated to the second space K2 in order to reduce or eliminate bubbles, and the second space when exposing the substrate P The liquid supply amount per unit time when the second liquid LQ2 is supplied to K2 may be the same, or the second gas K2 deaerated with respect to the second space K2 in order to reduce or eliminate bubbles. The liquid supply amount per unit time when the two liquids LQ2 are supplied is larger than the liquid supply amount per unit time when the second liquid LQ2 is supplied to the second space K2 when the substrate P is exposed. May be.
In the present embodiment, when it is determined that there are bubbles in the second liquid LQ2 forming the second immersion region, the second liquid LQ2 that has been deaerated to reduce or eliminate the gas portion is used. Although the liquid is supplied to the second space K2 for a predetermined time, bubbles are generated in the second liquid LQ2 forming the second liquid immersion region LR2 without managing the liquid supply time of the degassed second liquid LQ2. When it is determined that there is, the second liquid LQ2 forming the second liquid immersion region LR2 is continuously or intermittently observed by the observation device 60 while supplying the degassed second liquid LQ2 to the second space K2. The supply of the degassed second liquid LQ2 is stopped and / or the exposure light EL is irradiated when it is determined that the gas portion in the second liquid LQ2 has been reduced or eliminated to an extent that does not affect exposure and measurement. You may make it do.
In the present embodiment, when it is determined that there are bubbles in the second liquid LQ2 forming the second immersion region LR2, the degassed second liquid LQ2 is supplied to the second space K2 for a predetermined time. However, when the control device CONT determines that there are bubbles in the first liquid LQ1 forming the first immersion region LR1 based on the observation result of the observation device 60, the control device CONT uses the degassed first liquid LQ1. The first immersion mechanism 1 may be controlled so as to supply for a predetermined time. Since the first liquid supply unit 11 of the first liquid immersion mechanism 1 also includes a deaeration device, the first liquid supply unit 11 of the first liquid immersion mechanism 1 can supply the degassed first liquid LQ1. .
In each of the above-described embodiments, when performing an observation operation using the observation device 60, the liquid immersion regions LR1 and LR2 may be illuminated with light from a light source, as described in this embodiment. In this embodiment, various illumination methods and apparatuses and structures therefor will be described. For example, exposure light EL can be used as illumination light, and in this case, the intensity may be reduced. Further, a transparent material (for example, fluorite or quartz) is appropriately selected as the material of the transparent member 64 according to the wavelength of the exposure light EL. Moreover, it is preferable to use a highly sensitive image sensor or detection element according to the wavelength of the exposure light EL.
As shown in FIG. 13, the observation device 60 may have a light source 67 for illumination. As a light source for illumination, for example, an LED (white LED or the like) or an EL element (inorganic EL sheet or the like) can be used. Further, a dark field illumination method or a bright field illumination method can be used as the illumination method of the illumination light, and the dark field illumination method and the bright field illumination method can be switched. In this case, for example, the bright field illumination method is used to observe whether or not the spaces K1, K2 are sufficiently filled with the liquids LQ1, LQ2, and the dark field illumination method is used to observe small bubbles or small bubbles in the liquids LQ1, LQ2. It is possible to observe whether or not particles are mixed.
Further, as shown in FIG. 14, the illumination device 68 for illuminating the second immersion region LR2 is opposed to the observation device 60 above the second immersion region LR2, that is, across the second immersion region LR2. It may be arranged at a position, and illumination light may be irradiated from above on the second immersion region LR2. The illuminating device 68 can be configured by, for example, an LED (such as a white LED) or an EL element (such as an inorganic EL sheet). The illumination device 68 shown in FIG. 14 is provided so as to be able to advance and retreat with respect to the optical path space of the exposure light EL. When the control device CONT observes the second immersion region LR2 using the observation device 60, the illumination device 68 is illuminated. The device 68 is disposed in the optical path space of the exposure light EL, and the illumination light emitted from the illumination device 68 is irradiated from above on the second immersion region LR2. The illumination light emitted from the irradiation device 68 can illuminate the second immersion region LR2 of the second space K2 after passing through each optical element of the projection optical system PL. When the exposure light EL is allowed to pass through the projection optical system PL, such as when exposing the substrate P, the control device CONT retracts the illumination device 68 from the optical path space of the exposure light EL. In the example illustrated in FIG. 14, the illumination device 68 is disposed between the mask stage MST (mask M) and the projection optical system PL, but may be disposed above the mask stage MST (mask M).
Further, as shown in FIG. 15, the illumination device 68 may be attached to the lower surface of the mask stage MST. By doing so, it is possible to irradiate the second immersion region LR2 with illumination light from above. When observing the second immersion region LR2 using the observation device 60, the control device CONT drives the mask stage MST, arranges the illumination device 68 above the projection optical system PL, and emits it from the illumination device 68. The illuminated illumination light is irradiated from above on the second immersion region LR2 via each optical element of the projection optical system PL.
Further, as shown in FIG. 16, the fluorescent member (fluorescent plate) 69 is held by the mask stage MST, and the light (illumination light) generated from the fluorescent plate 69 is irradiated from above on the second immersion region LR2. May be. The mask stage MST is provided with an opening Km for allowing the exposure light EL to pass through. The light generated from the fluorescent plate 69 passes through the opening Km and then passes through each optical element of the projection optical system PL. The second immersion region LR2 is irradiated. In order to make the fluorescent plate 69 fluoresce, for example, the fluorescent plate 69 may be irradiated with the exposure light EL. Alternatively, a fluorescent plate opening different from the opening Km may be provided in a part of the mask stage MST, and the fluorescent plate may be fixed to the fluorescent plate opening.
It is also possible to illuminate the first immersion region LR1 using the illumination light described with reference to FIGS.
Further, as shown in FIG. 17, an illumination device 68 is provided in the vicinity of the nozzle member 70, and illumination light is emitted from the illumination device 68, so that the illumination light illuminates the first immersion region LR <b> 1 from the tilt direction. Can do. In the example shown in FIG. 17, the illumination device 68 is supported by a part of the body (column) 100 of the exposure apparatus EX via the first support mechanism 81. The column 100 supports a flange PF provided on the lens barrel PK of the projection optical system PL. Further, the column 100 can support the nozzle member 70 via the second support mechanism 82.
In the above description, the state of the liquids (LQ1, LQ2) forming the liquid immersion regions (LR1, LR2) is observed through the transparent member 64, but the lighting device 68 shown in FIG. An observation device (for example, an imaging device or a bubble detector) may be provided to observe the first liquid LQ1 forming the first immersion region LQ1 from the side. As such an observation apparatus, for example, a bubble detector as disclosed in WO 2004/053958 may be used. This bubble detector has a projection system and a detection system installed at positions away from the optical axis of the projection optical system. More specifically, the projection system and the detection system are provided in the scanning direction (X direction) so as to sandwich the projection area of the projection optical system, and detection light is transmitted from a plurality of projection units of the projection system to the liquid immersion area. When the light is incident obliquely and no bubbles are present in the liquid immersion area, the light is reflected by the bottom surface or the interface of the liquid immersion area (the upper surface of the transparent member 64 in the present application) and received by the light receiving system. When bubbles are present in the immersion area, light is scattered by the bubbles, so that the light is received by another light receiving system provided at a position different from the light receiving system, and the amount of bubbles is based on the amount of light received. Is required (dark field detection).
Further, an observation apparatus that can observe (check) the state of the first liquid LQ1 forming the first liquid immersion region LQ1 from the side in a state where the measurement stage PST2 is not opposed to the projection optical system PL is a measurement stage PST2. May be provided. In this case, for example, even during the exposure of the substrate P held on the substrate stage PST1, the state of the first immersion region LR1 formed on the substrate stage PST1 (substrate P) (presence of bubbles in the liquid LQ1) Or leakage of the liquid LQ1) can be checked using an observation device provided on the measurement stage PST2.
In each of the above-described embodiments, the projection optical system PL used in a state where the first space K1 on the lower surface T1 side and the second space K2 on the upper surface T2 side of the first optical element LS1 are filled with liquid. However, it is also possible to employ the projection optical system PL that is used in a state where only the first space K1 on the lower surface T1 side of the first optical element LS1 of the projection optical system PL is filled with the liquid. In this case, the observation target by the observation device 60 is only the first immersion region LR1.
In addition to observing the liquid immersion regions LR1 and LR2, the observation device 60 observes the lower surface T1 of the first optical element LS1 of the projection optical system PL, the lower surface 70A of the nozzle member 70, and an objective lens of a substrate alignment system (not shown). It can also be used for observation of the lower surface. In this case, the contamination state of the lower surface T1 of the first optical element LS1, the holding portion of the first optical element LS1, the lower surface 70A of the nozzle member, or the like is confirmed from the image acquired using the observation device 60, or the substrate alignment system It can be confirmed whether or not liquid (water) is attached to the lower surface of the objective lens or the housing of the substrate alignment system.
The liquid LQ in each embodiment described above is pure water. Pure water has an advantage that it can be easily obtained in large quantities at a semiconductor manufacturing factory or the like, and has no adverse effect on the photoresist, optical element (lens), etc. on the substrate P. In addition, pure water has no adverse effects on the environment, and since the impurity content is extremely low, it can be expected to clean the surface of the substrate P and the surface of the optical element provided on the front end surface of the projection optical system PL. . When the purity of pure water supplied from a factory or the like is low, the exposure apparatus may have an ultrapure water production device.
In the case where bubbles are observed in the above-described embodiment, when an image sensor or a transmittance sensor is used, an additive may be added to improve the sensitivity of the element or sensor. For example, a pigment may be added to the liquid in order to clarify the distinction between the bubble liquids. In this case, it is desirable that the dye does not have an absorption band for exposure light. A liquid to which such an additive is added may be used for observing the immersion state, and pure water to which no additive is added may be used during actual exposure.
The refractive index n of pure water (water) with respect to the exposure light EL having a wavelength of about 193 nm is said to be approximately 1.44. When ArF excimer laser light (wavelength 193 nm) is used as the light source of the exposure light EL, On the substrate P, the wavelength is shortened to 1 / n, that is, about 134 nm, and a high resolution can be obtained. Furthermore, since the depth of focus is enlarged by about n times, that is, about 1.44 times compared with that in the air, the projection optical system PL can be used when it is sufficient to ensure the same depth of focus as that in the air. The numerical aperture can be further increased, and the resolution is improved in this respect as well.
In order to increase the numerical aperture in the immersion method, it is conceivable to use a liquid having a high refractive index, for example, a liquid having a refractive index of 1.6 or more. In this case, in order to suppress the size (diameter) of the projection optical system PL, it is desirable to form a part of the projection optical system (especially a lens close to the image plane) with a material having a high refractive index. For example, it is preferable that the second optical element LS2 in contact with the second liquid LQ2 among the optical elements in the projection optical system PL is formed of at least one material of CaO (calcium oxide) and MgO (magnesium oxide). By doing so, a high numerical aperture can be realized under a feasible size. For example, even when an ArF excimer laser (wavelength 193 nm) is used, it is possible to realize a high numerical aperture of about 1.5 or more.
In each of the above-described embodiments, the first optical element LS1 arranged closest to the image plane side (substrate P side) is in the form of a plane parallel plate having no refractive power, but the first optical element LS1 has a refractive power. When it has, it is preferable to form this 1st optical element LS1 arrange | positioned at the most image surface side with the material of at least one among CaO and MgO.
That is, a projection optical system for projecting an image of an object onto a substrate through a liquid in an immersion area formed on the image plane side is arranged on the most image plane side and is CaO (calcium oxide) and MgO (magnesium oxide). It is preferable to provide the 1st optical element formed with at least one material. In addition, a projection optical system that projects an image of an object on a substrate via a liquid in an immersion area formed on the image plane side includes a first optical element disposed closest to the image plane, and a first optical element A second optical element disposed adjacent to the object side, and at least one of the first optical element and the second optical element is made of at least one material of CaO (calcium oxide) and MgO (magnesium oxide). Preferably it is formed. For example, one of the first optical element LS1 and the second optical element LS2 can be formed of CaO (calcium oxide) and the other can be formed of MgO (magnesium oxide).
When the first optical element LS1 has refractive power, the optical path space between the first optical element LS1 and the second optical element LS2 may not be filled with the second liquid LQ2.
CaO (calcium oxide) and MgO (magnesium oxide) have intrinsic birefringence at the wavelength of the exposure light EL (for example, 193 nm), but the signs of intrinsic birefringence are CaO (calcium oxide) and MgO (magnesium oxide). They are opposite to each other. Therefore, when one of the optical elements close to the image plane side (substrate P side) of the projection optical system is formed of CaO or MgO, the optical element near the optical element is formed of MgO or CaO. It is preferable to determine the thickness of the optical element in the optical axis direction so as to reduce the influence of intrinsic birefringence. Here, it is preferable that the crystal directions of these optical elements are aligned. Further, the optical element formed of CaO and the optical element formed of MgO may not be adjacent to each other.
For example, considering the case where the second optical element LS2 is formed of MgO (or CaO) and the third optical element LS3 is formed of CaO (or MgO), the thickness of these second optical elements LS2 in the optical axis direction and The thickness of the third optical element LS3 in the optical axis direction is preferably determined so as to be substantially proportional to the reciprocal of the intrinsic birefringence value of CaO and MgO. In the case described above, the first optical element LS1 closest to the image plane side (substrate P side) can be formed of quartz glass.
When the first optical element LS1 has refractive power, the first optical element LS1 is formed of MgO (or CaO), and the second optical element LS2 is formed of CaO (or MgO). The thickness in the optical axis direction of the first optical element LS1 and the thickness in the optical axis direction of the second optical element LS2 may be determined so as to be substantially proportional to the reciprocal of the intrinsic birefringence values of CaO and MgO. .
Now, when forming an optical element with CaO (calcium oxide), it is preferable to form an antireflection coating containing MgO (magnesium oxide) on the optical surface of the optical element. Moreover, when forming an optical element with MgO (magnesium oxide), it is preferable to form an antireflection coating containing CaO (calcium oxide) on the optical surface of the optical element.
As described above, when the immersion method is used, the numerical aperture NA of the projection optical system may be 0.9 to 1.5. When the numerical aperture NA of the projection optical system becomes large in this way, the imaging performance may deteriorate due to the polarization effect with random polarized light conventionally used as exposure light. desirable. In that case, linearly polarized illumination is performed in accordance with the longitudinal direction of the line pattern of the mask (reticle) line-and-space pattern. From the mask (reticle) pattern, the S-polarized light component (TE-polarized light component), that is, the line pattern It is preferable that a large amount of diffracted light having a polarization direction component is emitted along the longitudinal direction. When the space between the projection optical system PL and the resist applied on the surface of the substrate P is filled with a liquid, the space between the projection optical system PL and the resist applied on the surface of the substrate P is filled with air (gas). Compared with the case where the transmittance of the diffracted light of the S-polarized component (TE-polarized component) contributing to the improvement of the contrast is high on the resist surface, the numerical aperture NA of the projection optical system exceeds 1.0. Even in this case, high imaging performance can be obtained. Further, it is more effective to appropriately combine a phase shift mask and an oblique incidence illumination method (particularly a dipole illumination method) or the like according to the longitudinal direction of the line pattern as disclosed in JP-A-6-188169. In particular, the combination of the linearly polarized illumination method and the dipole illumination method is used when the periodic direction of the line-and-space pattern is limited to a predetermined direction or when the hole pattern is densely aligned along the predetermined direction. It is effective when For example, when illuminating a halftone phase shift mask (pattern with a half pitch of about 45 nm) with a transmittance of 6% using both the linearly polarized illumination method and the dipole illumination method, a dipole is formed on the pupil plane of the illumination system. If the illumination σ defined by the circumscribed circle of the two luminous fluxes is 0.95, the radius of each luminous flux on the pupil plane is 0.125σ, and the numerical aperture of the projection optical system PL is NA = 1.2, the randomly polarized light is The depth of focus (DOF) can be increased by about 150 nm rather than using it.
A combination of linearly polarized illumination and the small σ illumination method (an illumination method in which the σ value indicating the ratio between the numerical aperture NAi of the illumination system and the numerical aperture NAp of the projection optical system is 0.4 or less) is also effective.
Further, for example, an ArF excimer laser is used as the exposure light, and a fine line and space pattern (for example, a line and space of about 25 to 50 nm) is formed on the substrate by using the projection optical system PL with a reduction magnification of about 1/4. When exposing on P, depending on the structure of the mask M (for example, the fineness of the pattern and the thickness of chromium), the mask M acts as a polarizing plate due to the Wave guide effect, and the P-polarized component (TM polarized light) that lowers the contrast More diffracted light of the S polarization component (TE polarization component) than the diffracted light of component) is emitted from the mask M. In this case, it is desirable to use the above-mentioned linearly polarized illumination, but even if the mask M is illuminated with random polarized light, it is high even when the numerical aperture NA of the projection optical system PL is as large as 0.9 to 1.3. Resolution performance can be obtained.
When an extremely fine line-and-space pattern on the mask M is exposed on the substrate P, the P-polarized component (TM-polarized component) is larger than the S-polarized component (TE-polarized component) due to the Wire Grid effect. For example, an ArF excimer laser is used as exposure light, and a line and space pattern larger than 25 nm is exposed on the substrate P using the projection optical system PL with a reduction magnification of about 1/4. In this case, since the diffracted light of the S polarization component (TE polarization component) is emitted from the mask M more than the diffracted light of the P polarization component (TM polarization component), the numerical aperture NA of the projection optical system PL is 0.9. High resolution performance can be obtained even when the value is as large as -1.3.
Furthermore, not only linearly polarized illumination (S-polarized illumination) matched to the longitudinal direction of the line pattern of the mask (reticle) but also a circle centered on the optical axis as disclosed in JP-A-6-53120. A combination of the polarization illumination method that linearly polarizes in the tangential (circumferential) direction and the oblique incidence illumination method is also effective. In particular, when not only a line pattern extending in a predetermined direction but also a plurality of line patterns extending in different directions (a mixture of line and space patterns having different periodic directions) is included in the mask (reticle) pattern, Similarly, as disclosed in Japanese Patent Laid-Open No. 6-53120, an aperture of the projection optical system can be obtained by using both the polarization illumination method that linearly polarizes in the tangential direction of the circle centered on the optical axis and the annular illumination method. Even when the number NA is large, high imaging performance can be obtained. For example, a polarized illumination method and an annular illumination method (annular ratio) in which a half-tone phase shift mask having a transmittance of 6% (a pattern having a half pitch of about 63 nm) is linearly polarized in a tangential direction of a circle around the optical axis. 3/4), when the illumination σ is 0.95 and the numerical aperture of the projection optical system PL is NA = 1.00, the depth of focus (DOF) is more than that of using randomly polarized light. If the projection optical system has a numerical aperture NA = 1.2 with a pattern with a half pitch of about 55 nm, the depth of focus can be increased by about 100 nm.
Further, in addition to the above-described various illumination methods, for example, a progressive focus exposure method disclosed in JP-A-4-277612 and JP-A-2001-345245, or exposure light with multiple wavelengths (for example, two wavelengths) is used. It is also effective to apply a multi-wavelength exposure method that obtains the same effect as the progressive focus exposure method.
In each of the above-described embodiments, the optical element LS1 is attached to the tip of the projection optical system PL, and the optical characteristics of the projection optical system PL, for example, aberration (spherical aberration, coma aberration, etc.) can be adjusted by this lens. it can. The optical element attached to the tip of the projection optical system PL may be an optical plate used for adjusting the optical characteristics of the projection optical system PL. Alternatively, it may be a plane parallel plate that can transmit the exposure light EL.
When the pressure between the optical element at the tip of the projection optical system PL generated by the flow of the liquid LQ and the substrate P is large, the optical element is not exchangeable but the optical element is moved by the pressure. It may be fixed firmly so that there is no.
In the above-described embodiment, the space between the projection optical system PL and the surface of the substrate P is filled with the liquid LQ. However, for example, a cover glass made of a plane parallel plate is attached to the surface of the substrate P. The structure which fills the liquid LQ may be sufficient.
Although the liquid LQ of the above embodiments is water (pure water), a liquid other than water may be, for example, when the light source of exposure light EL is an F 2 laser, the F 2 laser beam Since the liquid LQ does not transmit water, the liquid LQ may be, for example, a fluorine-based fluid such as perfluorinated polyether (PFPE) or fluorine-based oil that can transmit the F 2 laser beam. In this case, the lyophilic treatment is performed by forming a thin film with a substance having a molecular structure having a small polarity including fluorine, for example, at a portion in contact with the liquid LQ. In addition, as the liquid LQ, the liquid LQ is transmissive to the exposure light EL, has a refractive index as high as possible, and is stable with respect to the photoresist applied to the projection optical system PL and the surface of the substrate P (for example, Cedar). Oil) can also be used. Also in this case, the surface treatment is performed according to the polarity of the liquid LQ to be used.
The substrate P in each of the above embodiments is not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus. (Synthetic quartz, silicon wafer) or the like is applied.
As the exposure apparatus EX, in addition to the step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask M by moving the mask M and the substrate P synchronously, the mask M and the substrate P Can be applied to a step-and-repeat type projection exposure apparatus (stepper) in which the pattern of the mask M is collectively exposed while the substrate P is stationary and the substrate P is sequentially moved stepwise.
Further, as the exposure apparatus EX, a reduced image of the first pattern is projected with the first pattern and the substrate P being substantially stationary (for example, a refraction type projection optical system that does not include a reflecting element at 1/8 reduction magnification). The present invention can also be applied to an exposure apparatus that performs batch exposure on the substrate P using the above. In this case, after that, with the second pattern and the substrate P substantially stationary, a reduced image of the second pattern is collectively exposed onto the substrate P by partially overlapping the first pattern using the projection optical system. It can also be applied to a stitch type batch exposure apparatus. Further, the stitch type exposure apparatus can be applied to a step-and-stitch type exposure apparatus in which at least two patterns are partially transferred on the substrate P, and the substrate P is sequentially moved.
The present invention can also be applied to a twin stage type exposure apparatus disclosed in Japanese Patent Application Laid-Open No. 10-163099, Japanese Patent Application Laid-Open No. 10-214783, and Japanese Translation of PCT International Publication No. 2000-505958. In the case of a twin stage type exposure apparatus, at least part of the observation apparatus 60 may be provided on each of the two substrate stages holding the substrate, or at least part of the observation apparatus 60 is provided only on one of the substrate stages. You can also.
In the above-described embodiment, the case where the present invention is applied to the exposure apparatus including the measurement stage and the substrate stage has been described. However, the exposure apparatus includes only one substrate stage without including the measurement stage. The present invention can be applied. In this case, as described in the third embodiment, at least a part of the observation device 60 is mounted on the substrate stage.
In each of the above-described embodiments, the transparent member 64, the optical system 61, and the image sensor 63 are mounted on the substrate stage or the measurement stage. For example, as disclosed in Japanese Patent Laid-Open No. 10-284412. The transparent member 64 is disposed on the stage, the image sensor 63 is disposed on a member (eg, base BP) provided separately from the stage, and the image sensor 63 receives light through the transparent member 64. You may make it observe the state of the liquid (LQ1, LQ2) which forms liquid immersion area | region (LR1, LR2).
In the third embodiment shown in FIG. 8, the transparent member 64, the optical system 61, and the imaging device 63 are mounted on the substrate stage PST1, but the transparent member 64 and the first light transmission system are mounted on the substrate stage PST1. The second light transmission system and the image sensor 63 are mounted on the measurement stage PST2, and the first light transmission system is interposed via the transparent member 64 in a state where the substrate stage PST1 and the measurement stage PST2 are in a predetermined positional relationship. May be received by the imaging device 63 via the second light transmission system, and the state of the liquids (LQ1, LQ2) forming the liquid immersion regions (LR1, LR2) may be observed.
Further, in the above-described fourth embodiment, bubbles (gas portions) are detected using the observation device 60 having the imaging element 63, and when bubbles are detected, the degassed liquid is flowed to reduce or reduce the bubbles. However, the method of detecting bubbles (gas portion) is not limited to the method using the image sensor 63, and other methods may be used to detect the bubbles and allow the degassed liquid to flow. For example, a light receiving element is installed in place of the image sensor, and the light transmittance is detected by the light receiving element by irradiating the liquid immersion area with the method illustrated in the fifth embodiment. You can also. In this case, the amount of bubbles can be determined by previously obtaining the transmittance when the bubbles are within the allowable range as a reference value and comparing the detected value with respect to the reference value. Note that the installation position of such a light receiving element is not limited to the lower side (optical axis position) of the projection optical system, but from the optical axis of the projection optical system as in the bubble detector disclosed in the aforementioned WO 2004/053958. You may install in the position which removed.
Furthermore, a part or all of the observation apparatus 60 can be configured to be detachable from the measurement stage or the substrate stage.
Further, an observation device that observes the state of the first immersion region LR1 from the side may be used. In this case, the observation apparatus may be arranged in the exposure apparatus EX (may be a part of the exposure apparatus), or may be a unit (for example, an optional module) different from the exposure apparatus.
In the above-described embodiment, an exposure apparatus that locally fills the liquid between the projection optical system PL and the substrate P is adopted. However, the present invention is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-124873. The present invention is also applicable to an immersion exposure apparatus in which the entire surface of a substrate to be exposed is covered with a liquid as disclosed in detail in Kaihei 10-303114, US Pat. No. 5,825,043 and the like.
The type of the exposure apparatus EX is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on the substrate P, but an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD). ) Or an exposure apparatus for manufacturing reticles or masks.
In the above-described embodiment, a light-transmitting mask in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. As disclosed in Japanese Patent No. 6,778,257, an electronic mask that forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed may be used.
The exposure apparatus of the present invention can also be applied to a type of exposure apparatus that does not have a projection optical system. In this case, exposure light from the light source passes through the optical element and is irradiated onto the liquid immersion area. As disclosed in the pamphlet of International Publication No. 2001/035168, the present invention is also applied to an exposure apparatus (lithography system) that exposes a line and space pattern on a substrate P by forming interference fringes on the substrate P. The invention can be applied.
As described above, the exposure apparatus EX according to the embodiment of the present application maintains various mechanical subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.
As shown in FIG. 18, a microdevice such as a semiconductor device includes a step 201 for designing the function and performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate which is a base material of the device. Manufacturing step 203, exposure processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus EX of the above-described embodiment, device assembly step (including processing steps such as dicing process, bonding process, and packaging process) 205, inspection It is manufactured through step 206 and the like. The exposure processing step includes processes such as the observation and treatment of the immersion area and the substrate development process described with reference to FIGS.
DESCRIPTION OF SYMBOLS 1 ... 1st immersion mechanism, 2 ... 2nd immersion mechanism, 38 ... Deaeration apparatus, 51 ... Substrate stage upper surface, 58 ... Measurement stage upper surface, 60 ... Observation apparatus, 61 ... Optical system, 62 ... Adjustment mechanism, 63 DESCRIPTION OF SYMBOLS ... Image pick-up element, 64 ... Transparent member, 65 ... Transparent member upper surface, 300 ... Reference member, 400 ... Illuminance unevenness sensor, 500 ... Aerial image measurement sensor, 600 ... Irradiation amount sensor, CONT ... Control device, DY ... Display device, EX ... Exposure apparatus, LQ1 ... first liquid, LQ2 ... second liquid, LR1 ... first liquid immersion area, LR2 ... second liquid immersion area, LS1 ... first optical element, LS2 ... second optical element, P ... substrate, PL ... Projection optical system, PST1 ... Substrate stage, PST2 ... Measurement stage
In an exposure apparatus that exposes a substrate via a projection optical system and a liquid in an immersion area formed on the image plane side of the projection optical system,
An immersion mechanism for forming an immersion area of liquid between a predetermined surface provided on the image plane side of the projection optical system and the first optical element;
An exposure apparatus comprising: an observation apparatus that observes a state of the immersion area.
The exposure apparatus according to claim 1, wherein the observation apparatus observes the state of the liquid immersion area through a predetermined surface arranged on the image plane side of the projection optical system.
The predetermined surface includes a surface of a transparent member;
The exposure apparatus according to claim 2, wherein the observation apparatus observes the liquid immersion area through the transparent member.
A stage movable on the image plane side of the projection optical system;
The exposure apparatus according to claim 2, wherein an upper surface of the stage includes the predetermined surface.
The exposure apparatus according to claim 4, wherein at least a part of the observation apparatus is provided inside the stage.
The exposure apparatus according to claim 4, wherein the stage is movable while holding the substrate.
The stage includes a first stage and a second stage that are movable independently of each other,
The first stage holds and moves the substrate, and the second stage holds and moves a measuring instrument that performs measurement related to exposure processing,
The exposure apparatus according to claim 4, wherein an upper surface of the second stage includes the predetermined surface.
The projection optical system has a second optical element close to the first optical element next to the image plane of the projection optical system,
The liquid immersion mechanism includes a first liquid immersion mechanism that forms a first liquid immersion region between the first optical element and the predetermined surface;
A second immersion mechanism that forms a second immersion region between the first optical element and the second optical element;
The exposure apparatus according to claim 1, wherein the observation apparatus is capable of observing each of the first liquid immersion area and the second liquid immersion area.
The exposure apparatus according to claim 8, wherein the observation apparatus observes the second liquid immersion region through the first optical element.
The observation apparatus has an adjustment mechanism capable of adjusting the focal position of the optical system of the observation apparatus,
The exposure apparatus according to claim 8 or 9, wherein each of the first liquid immersion area and the second liquid immersion area is observed by adjusting the focal position.
The exposure apparatus according to claim 1, wherein the observation apparatus has a field of view larger than the immersion area.
The observation device has a smaller field of view than the immersion area;
The exposure apparatus according to claim 1, wherein observation is performed while relatively moving the immersion area and the visual field.
The exposure apparatus according to claim 1, wherein the observation apparatus acquires an image of a liquid that forms the immersion area.
The exposure apparatus according to claim 12, wherein the observation apparatus includes a display device that displays the image.
The exposure apparatus according to claim 13 or 14, wherein the observation apparatus includes an imaging element.
The exposure apparatus according to claim 1, wherein the observation apparatus observes a mixed state of a gas in the liquid forming the immersion area.
The liquid immersion mechanism has a degassing device for degassing the liquid,
A controller that controls the liquid immersion mechanism to supply the degassed liquid when it is determined that a gas portion is present in the liquid forming the liquid immersion area based on the observation result of the observation apparatus; The exposure apparatus according to claim 1.
18. The exposure apparatus according to claim 17, wherein the degassing device degass the liquid so that the dissolved gas concentration is 5 ppm or less.
The exposure apparatus according to claim 17 or 18, wherein the control device supplies the degassed liquid while observing a state of the immersion area with the observation device.
The exposure apparatus according to any one of claims 17 to 19, wherein the control device adjusts a time for supplying the degassed liquid according to a size or amount of a gas portion in the liquid immersion region.
The projection optical system includes a first optical element closest to the image plane of the projection optical system, and a second optical element closest to the image plane next to the first optical element,
An immersion mechanism for forming a liquid immersion area between the first optical element and the second optical element;
The exposure apparatus according to any one of claims 1 to 21, wherein the observation device includes an illumination device.
The exposure apparatus according to any one of claims 8 to 21, wherein the first optical element is formed from one of CaO and MgO, and the second optical element is formed from the other of CaO and MgO.
The exposure apparatus according to claim 23, further comprising an MgO antireflection coating on a surface of an optical element formed of CaO, and a CaO antireflection coating on a surface of the optical element formed of MgO.
In an exposure apparatus that exposes a substrate through an optical element and a liquid in a liquid immersion region formed on the light emission side of the optical element,
An immersion mechanism for filling a space between the predetermined surface disposed on the light emitting side of the optical element and the optical element;
An exposure apparatus comprising: an observation device that observes a liquid state between the optical element and the predetermined surface.
26. The exposure apparatus according to claim 25, further comprising a projection optical system, wherein the optical element is an optical element closest to an image plane of the projection optical system.
27. A device manufacturing method using the exposure apparatus according to any one of claims 1 to 26.
An exposure method for exposing a substrate through a liquid in a liquid immersion area formed on a light emission side of an optical element,
Exposing the substrate through the liquid in the immersion area;
Replacing the exposed substrate with an unexposed substrate;
Detecting a gas portion in the liquid in the immersion area during the exchange of the substrate.
29. The exposure method according to claim 28, further comprising a step of reducing the gas part in the liquid immersion area when a gas part is detected in the liquid in the liquid immersion area.
30. The exposure method according to claim 29, wherein the treatment includes collecting the liquid in the immersion area while supplying the degassed liquid to the immersion area.
31. The exposure method according to any one of claims 28 to 30, wherein the substrate is exposed and exchanged on a first stage, and a gas portion in a liquid in a liquid immersion area is detected on a second stage.
32. The exposure method according to claim 31, further comprising moving the immersion area between the first stage and the second stage.
The optical element includes a first optical element and a second optical element that are arranged in an order closer to the substrate during exposure, and includes a first space between the first optical element and the substrate, a first optical element, and a first optical element. 33. The exposure method according to any one of claims 28 to 32, wherein an immersion region is formed in at least one of the second spaces between the two optical elements.
34. The exposure method according to claim 33, further comprising detecting a gas portion in the liquid in the liquid immersion area formed in the second space when the liquid in the liquid immersion area formed in the second space is exchanged.
35. The exposure method according to any one of claims 28 to 34, wherein a gas portion in the liquid in the immersion area is detected every time exposure processing of a predetermined number of substrates is completed.
Exposing the substrate by the exposure method according to any one of claims 28 to 35;
A method for manufacturing a device, comprising processing a developed substrate.
JP2011032385A 2004-08-03 2011-02-17 Exposure apparatus and observation method Active JP5152356B2 (en)
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JP2012080480A Pending JP2012129560A (en) 2004-08-03 2012-03-30 Exposure apparatus, exposure method, and device manufacturing method
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