JP2005209705A - Exposure device and manufacturing method for device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure device capable of detecting the deterioration or the like of a pattern image resulting from a gas section in a liquid when a substrate is irradiated with an exposure light, and exposed and treated through a projection optical system and the liquid. <P>SOLUTION: The exposure device EX has a gas detection system 40 optically detecting the presence of the gas in the liquid immersion region AR2 of the liquid LQ formed on a substrate P. The gas detecting system 40 projects a detection light La approximately parallel with the surface of the substrate P to the liquid immersion region AR2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exposure apparatus and a device manufacturing method for exposing a substrate by irradiating the substrate with exposure light via a projection optical system and a liquid.

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)
δ = ± k ₂ · λ / NA ² (2)
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 equations (1) and (2), it can be seen that if the exposure wavelength λ is shortened and the numerical aperture NA is increased to increase the resolution R, the depth of focus δ becomes narrower.

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.
International Publication No. 99/49504 Pamphlet

  When exposure processing is performed by the immersion method, if a gas portion such as a bubble exists in the liquid between the projection optical system and the substrate, the pattern image formed on the substrate may be deteriorated by the bubble (gas portion). There is. For example, the bubbles may be generated in the liquid after the supply as well as when the bubbles are included in the supplied liquid. If such an image formation failure of an image of a pattern is left unattended, it will be discovered as a defective product after it becomes a final device, which may lead to a decrease in device productivity.

  The present invention has been made in view of such circumstances, and when performing exposure processing by irradiating a substrate with exposure light through a projection optical system and a liquid, a pattern image caused by a gas portion in the liquid is obtained. An object of the present invention is to provide an exposure apparatus capable of detecting deterioration and the like, and a device manufacturing method using the exposure apparatus. It is another object of the present invention to provide an exposure apparatus that can suppress a decrease in productivity and a device manufacturing method that uses this exposure apparatus even when the immersion method is used.

In order to solve the above-described problems, the present invention adopts the following configuration corresponding to FIGS. 1 to 8 shown in the embodiment.
The exposure apparatus (EX) of the present invention forms a liquid (LQ) immersion area (AR2) on a substrate (P), and the substrate (P) through the projection optical system (PL) and the liquid (LQ). In an exposure apparatus that exposes a substrate (P) by irradiating exposure light (EL) thereon, a gas detection system (40) for optically detecting the presence or absence of a gas portion (100) in the immersion area (AR2) is provided. The gas detection system (40) projects detection light (La) substantially parallel to the surface of the substrate (P) to the liquid immersion area (AR2).

  According to the present invention, by detecting the presence or absence of a gas portion in the liquid immersion area formed on the substrate by the gas detection system, for example, during exposure of the substrate, the pattern image can be generated due to the gas portion. It is possible to determine whether or not an imaging failure or a defective shot has occurred, and appropriate measures can be taken to maintain high device productivity. In addition, since it is possible to start exposure of the substrate after confirming that there is no gas portion in the optical path of the exposure light, it is possible to suppress the occurrence of defective devices. Since the gas detection system projects detection light substantially parallel to the substrate surface to the liquid immersion area formed on the substrate, the presence / absence of a gas portion in a wide range of the liquid immersion area ( Almost simultaneously).

  The exposure apparatus (EX) of the present invention forms a liquid (LQ) immersion area (AR2) on a substrate (P), and the substrate (P) through the projection optical system (PL) and the liquid (LQ). In an exposure apparatus that exposes a substrate (P) by irradiating exposure light (EL) thereon, a gas detection system (40) for optically detecting the presence or absence of a gas portion (100) in the immersion area (AR2) is provided. The gas detection system (40) includes a projection system (41) that projects detection light (La) onto the liquid (LQ), and a light receiving system (42) that receives light via the liquid (LQ). The projection system (41) includes a first light transmission system (74) that guides detection light (La) downward from an upper position of the liquid immersion area (AR2), and detection light from the first light transmission system (74). And a second light transmission system (76) that makes (La) substantially parallel to the surface of the substrate (P).

  According to the present invention, by detecting the presence or absence of a gas portion in a liquid immersion area formed on a substrate by a gas detection system, for example, during exposure of the substrate, a pattern image caused by the gas portion. Thus, it is possible to grasp whether or not an imaging failure or a defective shot has occurred, and appropriate measures can be taken to maintain high device productivity. In addition, since it is possible to start exposure of the substrate after confirming that there is no gas portion in the optical path of the exposure light, it is possible to suppress the occurrence of defective devices. Even if there are other devices or members around the projection optical system, the substrate, etc. and the arrangement of the optical system of the gas detection system is limited, the arrangement of the optical system of the gas detection system is limited by the first light transmission system. The degree of freedom is improved. Therefore, even if there is the restriction, the detection light from the first light transmission system is smoothly projected through the second light transmission system substantially parallel to the substrate surface. And since the detection light substantially parallel to the substrate surface is projected to the liquid immersion area formed on the substrate, the presence or absence of a gas portion is detected collectively (substantially simultaneously) in a wide range of the liquid immersion area. be able to.

  According to the present invention, when exposure processing is performed based on the liquid immersion method, the presence or absence of a gas portion is detected in a wide range of the liquid immersion region formed on the substrate, which is a portion that greatly affects the pattern transfer accuracy by the gas detection system. Can be detected in a batch. Therefore, it is possible to take an appropriate measure for maintaining good productivity based on the detection result.

The exposure apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing an embodiment of the exposure apparatus of the present invention.
In FIG. 1, an exposure apparatus EX includes a mask stage MST that supports a mask M, a substrate stage PST that supports a substrate P, and an illumination optical system IL that illuminates the mask M supported by the mask stage MST with exposure light EL. A projection optical system PL that projects and exposes the pattern image of the mask M illuminated by the exposure light EL onto the substrate P supported by the substrate stage PST, and a control device CONT that controls the overall operation of the exposure apparatus EX. I have.

  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 increase the depth of focus. A liquid supply mechanism 10 for supplying the liquid LQ to the substrate P, and a liquid recovery mechanism 20 for recovering the liquid LQ on the substrate P. The exposure apparatus EX, while transferring at least the pattern image of the mask M onto the substrate P, is applied to a part on the substrate P including the projection area AR1 of the projection optical system PL by the liquid LQ supplied from the liquid supply mechanism 10. An immersion area AR2 that is larger than the projection area AR1 and smaller than the substrate P is locally formed. Specifically, the exposure apparatus EX employs a local liquid immersion method in which the liquid LQ is filled between the optical element 2 at the image plane side end portion of the projection optical system PL and the surface of the substrate P disposed on the image plane side. The pattern of the mask M is projected onto the substrate P by irradiating the substrate P with the liquid LQ between the projection optical system PL and the substrate P and the exposure light EL that has passed through the mask M via the projection optical system PL. Exposure.

  The exposure apparatus EX also includes a gas detection system 40 that optically detects the presence or absence of a gas portion in the liquid immersion area AR2 of the liquid LQ formed on the substrate P. The gas detection system 40 includes a projection system 41 that projects detection light La substantially parallel to the surface of the substrate P to the liquid LQ in the immersion area AR2.

  In this embodiment, the exposure apparatus EX is a scanning exposure apparatus (so-called so-called exposure apparatus EX) that exposes a 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 direction that coincides with the optical axis AX of the projection optical system PL is the Z-axis direction, the synchronous movement direction (scanning direction) between the mask M and the substrate P in the plane perpendicular to the Z-axis direction is the X-axis direction, A direction (non-scanning direction) perpendicular to the Z-axis direction and the X-axis direction is defined as a Y-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively.

The illumination optical system IL illuminates the mask M supported by the mask stage MST with the exposure light EL, and the exposure light source, and an optical integrator and an optical integrator for uniformizing the illuminance of the light beam emitted from the exposure light source A condenser lens that collects the exposure light EL from the light source, a relay lens system, a variable field stop that sets the illumination area on the mask M by the exposure light EL in a slit shape, and the like. 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 illumination optical system IL, for example, far ultraviolet light (g-line, h-line, i-line) and KrF excimer laser light (wavelength 248 nm) emitted from a mercury lamp (e.g. DUV light), vacuum ultraviolet light (VUV light) such as ArF excimer laser light (wavelength 193 nm) and F ₂ laser light (wavelength 157 nm), or the like is used. In this embodiment, ArF excimer laser light is used.

  In the present embodiment, pure water is used as the liquid LQ. Pure water is not only ArF excimer laser light, but also far ultraviolet light (DUV light) such as ultraviolet emission lines (g-line, h-line, i-line) emitted from mercury lamps and KrF excimer laser light (wavelength 248 nm). Can also be transmitted.

  The mask stage MST is movable while holding the mask M. For example, the mask M is fixed by vacuum suction (or electrostatic suction). The mask stage MST can be moved two-dimensionally in the plane perpendicular to the optical axis AX of the projection optical system PL, that is, the XY plane, and can be slightly rotated in the θZ direction by a mask stage driving device MSTD including a linear motor or the like. The mask stage MST is movable at a scanning speed specified in the X-axis direction, and the movement stroke in the X-axis direction is such that the entire surface of the mask M can cross at least the optical axis AX of the projection optical system PL. have.

  A movable mirror 31 is provided on the mask stage MST. A laser interferometer 32 is provided at a position facing the moving mirror 31. The position of the mask M on the mask stage MST in the two-dimensional direction and the rotation angle in the θZ direction (including rotation angles in the θX and θY directions in some cases) are measured in real time by the laser interferometer 32, and the measurement result is a control device. Output to CONT. The control device CONT controls the position of the mask M supported by the mask stage MST by driving the mask stage drive device MSTD based on the measurement result of the laser interferometer 32.

  The projection optical system PL projects and exposes the pattern of the mask M onto the substrate P at a predetermined projection magnification β, and includes a plurality of optical elements including an optical element (lens) 2 provided at the front end portion on the substrate P side. These optical elements 2 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 or 1/5. Note that the projection optical system PL may be either an equal magnification system or an enlargement system.

The optical element 2 at the tip of the projection optical system PL of the present embodiment is exposed from the barrel PK, and the liquid LQ in the liquid immersion area AR2 comes into contact therewith. The optical element 2 is made of meteorite. Since the surface of the meteorite or the surface to which MgF ₂ , Al ₂ O ₃ , SiO ₂ or the like is attached has a high affinity with water, the liquid LQ can be brought into close contact with almost the entire liquid contact surface 2A of the optical element 2. it can. That is, in the present embodiment, the liquid (water) LQ having high affinity with the liquid contact surface 2A of the optical element 2 is supplied, so that the adhesion between the liquid contact surface 2A of the optical element 2 and the liquid LQ is high. And the optical path between the optical element 2 and the substrate P can be reliably filled with the liquid LQ. The optical element 2 may be quartz having a high affinity for water. Further, the liquid contact surface 2A of the optical element 2 may be subjected to a hydrophilization (lyophilic process) to further increase the affinity with the liquid LQ.

  The substrate stage PST is movable while holding the substrate P, and includes an XY stage 51 and a Z tilt stage 52 mounted on the XY stage 51. The XY stage 51 is supported in a non-contact manner above the upper surface of the stage base SB via a gas bearing (air bearing) which is a non-contact bearing (not shown). The XY stage 51 (substrate stage PST) is supported in a non-contact manner with respect to the upper surface of the stage base SB, and is in a plane perpendicular to the optical axis AX of the projection optical system PL by the substrate stage driving device PSTD including a linear motor and the like. That is, it can move two-dimensionally in the XY plane and can rotate in the θZ direction. A Z tilt stage 52 is mounted on the XY stage 51, and a substrate P is held on the Z tilt stage 52 by, for example, vacuum suction or the like via a substrate holder (not shown). The Z tilt stage 52 is movably provided in the Z-axis direction, the θX direction, and the θY direction. The substrate stage driving device PSTD is controlled by the control device CONT.

  A movable mirror 33 is provided on the substrate stage PST (Z tilt stage 52). A laser interferometer 34 is provided at a position facing the movable mirror 33. The two-dimensional position and rotation angle of the substrate P on the substrate stage PST are measured in real time by the laser interferometer 34, and the measurement result is output to the control device CONT. The controller CONT positions the substrate P supported by the substrate stage PST by driving the substrate stage driving device PSTD including a linear motor or the like based on the measurement result of the laser interferometer 34.

  Further, the exposure apparatus EX includes a focus / leveling detection system (not shown) that detects the position of the surface of the substrate P supported by the substrate stage PST. The light reception result of the focus / leveling detection system is output to the control device CONT. The control device CONT can detect the position information of the surface of the substrate P in the Z-axis direction and the tilt information of the substrate P in the θX and θY directions based on the detection result of the focus / leveling detection system. The Z tilt stage 52 controls the focus position and tilt angle of the substrate P to adjust the surface of the substrate P to the image plane of the projection optical system PL by the auto focus method and the auto leveling method. Positioning is performed in the X-axis direction and the Y-axis direction. Needless to say, the Z tilt stage and the XY stage may be provided integrally.

  In the vicinity of the substrate stage PST, a substrate alignment system (not shown) for detecting an alignment mark on the substrate P or a reference mark (described later) provided on the substrate stage PST (Z tilt stage 52) is provided. A mask alignment system 360 for detecting a reference mark on the substrate stage PST (Z tilt stage 52) via the mask M and the projection optical system PL is provided in the vicinity of the mask stage MST. The mask alignment system 360 constitutes an alignment system of a so-called TTM (through-the-mask) system (also referred to as a TTR (through-the-reticle) system). As the configuration of the substrate alignment system, for example, the one disclosed in JP-A-4-65603 can be used, and as the configuration of the mask alignment system 360, for example, disclosed in JP-A-7-176468. Can be used.

  A plate member 56 is provided on the substrate stage PST (Z tilt stage 52) so as to surround the substrate P held by the substrate stage PST. The plate member 56 is an annular member and is disposed outside the substrate P. The plate member 56 has a flat surface (flat portion) 57 having substantially the same height (level) as the surface of the substrate P held by the substrate stage PST. The flat surface 57 is disposed around the outside of the substrate P held by the substrate stage PST.

  The plate member 56 is formed of a material having liquid repellency such as polytetrafluoroethylene (Teflon (registered trademark)). Therefore, the flat surface 57 has liquid repellency. For example, the flat surface 57 may be made liquid-repellent by forming the plate member 56 with a predetermined metal and applying a liquid-repellent treatment to at least the flat surface 57 of the metal plate member 56. As the liquid repellent treatment of the plate member 56 (flat surface 57), for example, a fluorine-based resin material such as polytetrafluoroethylene, an acrylic resin material, a silicon-based resin material or the like is applied, or the above-described liquid repellent treatment is performed. A thin film made of a liquid material is attached. Further, the film for surface treatment may be a single layer film or a film composed of a plurality of layers. As the liquid repellent material for making it liquid repellent, a material that is insoluble in the liquid LQ is used. Further, the application area of the liquid repellent material may be applied to the entire surface of the plate member 56, or may be applied to only a part of the area requiring liquid repellency such as the flat surface 57, for example. You may do it.

  Since the plate member 56 having the flat surface 57 that is substantially flush with the surface of the substrate P is provided around the substrate P, even when the edge region E of the substrate P is subjected to immersion exposure, the plate member 56 is provided outside the edge portion of the substrate P. Since there is almost no step portion, the liquid LQ can be held under the projection optical system PL, and the liquid immersion area AR2 can be satisfactorily formed on the image plane side of the projection optical system PL. Further, by making the flat surface 57 liquid repellent, the liquid LQ is prevented from flowing out to the outside of the substrate P (outside the flat surface 57) during immersion exposure, and the liquid LQ is smoothly recovered even after immersion exposure. Thus, the liquid LQ can be prevented from remaining on the flat surface 57.

  The liquid supply mechanism 10 is for supplying a predetermined liquid LQ to the image plane side of the projection optical system PL, and includes a liquid supply unit 11 capable of delivering the liquid LQ and one end of the liquid supply unit 11. Supply pipes 12 (12A, 12B) to be connected are provided. The liquid supply unit 11 includes a tank that stores the liquid LQ, a pressure pump, and the like. When forming the liquid immersion area AR2 on the substrate P, the liquid supply mechanism 10 supplies the liquid LQ onto the substrate P.

  The liquid recovery mechanism 20 is for recovering the liquid LQ on the image plane side of the projection optical system PL, and has a liquid recovery part 21 that can recover the liquid LQ and one end connected to the liquid recovery part 21. The recovery pipe 22 (22A, 22B) is provided. The 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 liquid LQ and gas, and a tank that stores the recovered liquid LQ. As a vacuum system, a vacuum system in a factory where the exposure apparatus EX is disposed may be used without providing the exposure apparatus EX with a vacuum pump. In order to form the immersion area AR2 on the substrate P, the liquid recovery mechanism 20 recovers a predetermined amount of the liquid LQ on the substrate P supplied from the liquid supply mechanism 10.

  A liquid recovery port 61 constituting a second liquid recovery mechanism 60 that recovers the liquid LQ that has flowed out of the substrate P is provided outside the plate member 56 in the Z tilt stage 52. The liquid recovery port 61 is an annular groove formed so as to surround the plate member 56, and a liquid absorbing member 62 made of a sponge-like member, a porous body, or the like is disposed therein. The liquid absorbing member 62 is replaceable. In addition, one end of a recovery channel formed inside the substrate stage PST is connected to the liquid recovery port 61, and the other end of the recovery pipe is a second liquid recovery unit (sometimes provided outside the substrate stage PST). Are also connected). The second liquid recovery unit, like the liquid recovery unit 21, is a vacuum system (suction device) such as a vacuum pump, a gas-liquid separator that separates the recovered liquid LQ and gas, and a tank that stores the recovered liquid LQ. It has.

  By providing the second liquid recovery mechanism 60, even if the liquid LQ flows out to the outside of the substrate P and the plate member 56, the outflowing liquid LQ can be recovered, and the substrate due to vaporization of the outflowing liquid LQ. It is possible to prevent the occurrence of inconvenience such as an environmental change where P is placed. The second liquid recovery mechanism 60 (second liquid recovery unit) may be configured to spill the liquid LQ recovered by the liquid absorbing member 62 outside the substrate stage PST by its own weight without providing a vacuum system. Furthermore, without providing the second liquid recovery unit including the vacuum system, only the liquid absorbing member 62 is disposed on the substrate stage PST, and the liquid absorbing member 62 that has absorbed the liquid LQ is periodically (eg, for each lot). It is good also as a structure exchanged. In this case, the substrate stage PST varies in weight depending on the liquid LQ, but the stage positioning accuracy can be maintained by changing the stage control parameter according to the weight of the liquid LQ collected by the liquid absorbing member 62.

  A flow path forming member 70 is disposed in the vicinity of the optical element 2 at the end of the projection optical system PL. The flow path forming member 70 is an annular member provided so as to surround the optical element 2 above the substrate P (substrate stage PST). The flow path forming member 70 can be formed of, for example, aluminum, titanium, stainless steel, duralumin, and an alloy containing these. Alternatively, the flow path forming member 70 may be configured by a transparent member (optical member) having light permeability such as glass (quartz).

  The flow path forming member 70 includes a liquid supply port 13 (13A, 13B) provided above the substrate P (substrate stage PST) and disposed so as to face the surface of the substrate P. In the present embodiment, the flow path forming member 70 has two liquid supply ports 13A and 13B. The liquid supply ports 13A and 13B are provided on the lower surface 70A of the flow path forming member 70.

  Further, the flow path forming member 70 has supply flow paths 14 (14A, 14B) corresponding to the liquid supply ports 13 (13A, 13B) therein. One end portions of the supply flow paths 14A and 14B are connected to the supply portion 11 via supply tubes 12A and 12B, respectively, and the other end portions are connected to the liquid supply ports 13A and 13B, respectively.

  In the middle of the supply pipes 12A and 12B, flow controllers 16A and 16B that are supplied from the liquid supply unit 11 and control the amount of liquid supplied per unit time to the liquid supply ports 13A and 13B are provided. Control of the liquid supply amount by the flow controllers 16A and 16B is performed under a command signal of the control device CONT.

  Furthermore, the flow path forming member 70 includes a liquid recovery port 23 provided above the substrate P (substrate stage PST) and disposed so as to face the surface of the substrate P. In the present embodiment, the flow path forming member 70 has two liquid recovery ports 23A and 23B. The liquid recovery ports 23A and 23B are provided on the lower surface 70A of the flow path forming member 70.

  Further, the flow path forming member 70 has a recovery flow path 24 (24A, 24B) corresponding to the liquid recovery port 23 (23A, 23B) therein. One end portions of the recovery flow paths 24A and 24B are connected to the first liquid recovery portion 21 via recovery tubes 22A and 22B, respectively, and the other end portions are connected to the liquid recovery ports 23A and 23B, respectively.

  In the present embodiment, the flow path forming member 70 constitutes a part of each of the liquid supply mechanism 10 and the liquid recovery mechanism 20. The liquid supply ports 13A and 13B constituting the liquid supply mechanism 10 are provided at respective positions on both sides in the X-axis direction across the projection area AR1 of the projection optical system PL, and the liquid constituting the liquid recovery mechanism 20 The recovery ports 23A and 23B are provided outside the liquid supply ports 13A and 13B of the liquid supply mechanism 10 with respect to the projection area AR1 of the projection optical system PL.

  The operations of the liquid supply unit 11 and the flow rate controllers 16A and 16B are controlled by the control device CONT. When supplying the liquid LQ onto the substrate P, the control device CONT delivers the liquid LQ from the liquid supply unit 11 and is provided above the substrate P via the supply pipes 12A and 12B and the supply flow paths 14A and 14B. The liquid LQ is supplied onto the substrate P from the liquid supply ports 13A and 13B. At this time, the liquid supply ports 13A and 13B are arranged on both sides of the projection area AR1 of the projection optical system PL, and the liquid LQ can be supplied from both sides of the projection area AR1 via the liquid supply ports 13A and 13B. . Further, the amount per unit time of the liquid LQ supplied from the liquid supply ports 13A and 13B onto the substrate P can be individually controlled by the flow rate controllers 16A and 16B provided in the supply pipes 12A and 12B, respectively. It is.

  The liquid recovery operation of the liquid recovery unit 21 is controlled by the control device CONT. The control device CONT can control the liquid recovery amount per unit time by the liquid recovery unit 21. The liquid LQ on the substrate P recovered from the liquid recovery ports 23A and 23B provided above the substrate P is recovered through the recovery channels 24A and 24B of the channel forming member 70 and the recovery tubes 22A and 22B. Collected by the unit 21.

  In the present embodiment, the supply pipes 12A and 12B are connected to one liquid supply section 11. However, a plurality (two in this case) of liquid supply sections 11 corresponding to the number of supply pipes are provided, and the supply pipe 12A is provided. , 12B may be connected to each of the plurality of liquid supply sections 11. Further, the recovery pipes 22A and 22B are connected to one liquid recovery part 21, but a plurality (two in this case) of liquid recovery parts 21 corresponding to the number of recovery pipes are provided, and each of the recovery pipes 22A and 22B is provided. May be connected to each of the plurality of liquid recovery sections 21.

  In the present embodiment, the liquid supply ports 13A and 13B for supplying the liquid LQ and the liquid recovery ports 23A and 23B for recovering the liquid LQ are formed on the lower surface 70A of one flow path forming member 70. However, the flow path forming member (supply member) having the liquid supply ports 13A and 13B and the flow path forming member (collecting member) having the liquid recovery ports 23A and 23B may be provided separately.

The liquid contact surface 2A of the optical element 2 of the projection optical system PL and the lower surface (liquid contact surface) 70A of the flow path forming member 70 are lyophilic (hydrophilic). In the present embodiment, the liquid contact surfaces of the optical element 2 and the flow path forming member 70 are subjected to lyophilic treatment, and the liquid contact surfaces of the optical element 2 and the flow path forming member 70 are changed by the lyophilic treatment. It is lyophilic. In other words, at least the liquid contact surface of the surface of the member facing the exposed surface (surface) of the substrate P held by the substrate stage PST is lyophilic. Since the liquid LQ in the present embodiment is water having a large polarity, as a lyophilic treatment (hydrophilic treatment), for example, a thin film is formed of a substance having a molecular structure with a large polarity such as alcohol, whereby the optical element 2 and the flow path are formed. Hydrophilicity is imparted to the liquid contact surface of the forming member 70. That is, when water is used as the liquid LQ, it is preferable to provide a liquid contact surface with a highly polar molecular structure such as an OH group. Alternatively, MgF ₂ , Al ₂ O ₃ , SiO ₂ or the like may be provided on the liquid contact surface.

  In this embodiment, the lower surface (surface facing the substrate P side) 70A of the flow path forming member 70 is a substantially flat surface, and the lower surface 2A of the optical element 2 that is the image surface side end surface of the projection optical system PL is also substantially the same. It is a flat surface. The lower surface 70A and the lower surface 2A are substantially flush.

  In this embodiment, the lower surface 70A of the flow path forming member 70 is a substantially flat surface, but the liquid recovery port 23 (23A, 23B) with respect to the projection optical system PL of the lower surface 70A of the flow path forming member 70. In a further outer region, a surface inclined with respect to the XY plane, specifically, away from the surface of the substrate P toward the outer side with respect to the projection region AR1 (immersion region AR2) (to go upward). (Ii) An inclined surface (trap surface) having a predetermined length to be inclined may be provided. By doing so, the liquid LQ between the projection optical system PL and the substrate P accompanying the movement of the substrate P is captured by the trap surface even if it tries to flow outside the lower surface 70A of the flow path forming member 70. The outflow of the liquid LQ can be prevented. Here, the trap surface is treated with a lyophilic solution to make it lyophilic, thereby protecting the photosensitive material from a film applied to the surface of the substrate P (photosensitive material film such as photoresist, antireflection film or liquid). The liquid LQ that has flowed out of the liquid recovery port 23 is captured by the trap surface.

  The gas detection system 40 optically detects the presence or absence of a gas portion including bubbles in the liquid immersion area AR2 of the liquid LQ formed on the substrate P. A projection system 41 that projects detection light La substantially parallel to the surface of the substrate P is provided. The projection system 41 includes a light source 43 that emits a light beam, a pinhole 44 that shapes the light beam emitted from the light source 43 into a circular light beam, a collimator lens 45 that collimates the light beam that has passed through the pinhole 44, and a collimator A beam expander 46 that expands the diameter of the light beam that has passed through the lens 45, a mirror 47 that bends the optical path of the light beam that has passed through the beam expander 46 to be parallel to the surface of the substrate P, and a first light beam that expands the light beam through the mirror 47. And second cylindrical lenses 48 and 49.

  The light source 43 is constituted by a laser light irradiation device, and emits laser light having a wavelength different from that of the exposure light EL. In the present embodiment, the light source 43 emits He—Ne laser light (wavelength 633 nm). The laser light emitted from the light source 43 is shaped into a circular beam by the pinhole 44 and then converted into parallel light by the collimator lens 45. The light beam that has passed through the collimator lens 45 is expanded to a light beam diameter of about several millimeters by the beam expander 46 and then enters the first cylindrical lens 48 via the mirror 47. Here, the mirror 47 makes the optical path of the light beam substantially parallel to the surface of the substrate P, and in this embodiment, substantially parallel to the XY plane. The first cylindrical lens 48 spreads the light beam in a direction (XY direction) substantially parallel to the surface of the substrate P. The light beam that has passed through the first cylindrical lens 48 is incident on the second cylindrical lens 49. The second cylindrical lens 49 expands the light beam in a direction (Z-axis direction) substantially perpendicular to the surface of the substrate P. Thus, the laser light emitted from the light source 43 is converted into a sheet-like light beam, so-called laser sheet light, by the projection system 41 including the first and second cylindrical lenses 48 and 49. The laser sheet light (detection light) La is emitted from the side of the liquid immersion area AR2 of the liquid LQ filled between the projection optical system PL and the substrate P to the liquid LQ in the liquid immersion area AR2. Irradiated substantially parallel to the P surface.

  The projection system 41 irradiates detection light (laser sheet light) La so as to cover an area having a predetermined size or more in the liquid immersion area AR2. In the present embodiment, the projection system 41 irradiates the irradiation area in the Z-axis direction of the detection light (laser sheet light) La on the liquid immersion area AR2 with the image plane side end of the projection optical system PL (ie, the liquid contact of the optical element 2). The distance WD is set to be substantially the same as the distance WD between the surface 2A) and the substrate P or larger than the distance WD (more than the distance WD). The distance (so-called working distance) WD between the image plane side end of the projection optical system PL and the substrate P is, for example, about 1 to 5 mm. Further, as described above, since the lower surface 2A of the projection optical system PL and the lower surface 70A of the flow path forming member 70 are substantially flush, the distance between the lower surface 70A of the flow path forming member 70 and the substrate P is also a distance. It is almost the same as WD.

  Further, the projection system 41 has an irradiation area in the XY direction of the detection light (laser sheet light) La for the liquid immersion area AR2 larger than the projection area AR1 of the projection optical system PL that is the irradiation area of the exposure light EL (projection area AR1). It is set to be larger than the size of AR1. Furthermore, the irradiation area of the detection light La is preferably larger than the liquid immersion area AR2.

  In this embodiment, He—Ne laser light is used as the detection light La. However, light that is non-photosensitive to the photosensitive material applied on the substrate P may be used, and even single wavelength light may be used. Broadband light may be used.

  FIG. 2 is a plan view of the substrate stage PST (Z tilt stage 52) as viewed from above. In FIG. 2, the movable mirror 33 is provided at two mutually perpendicular edges of the Z tilt stage 52 having a rectangular shape in plan view. In addition, a substrate holder that constitutes a part of the Z tilt stage 52 that holds the substrate P is disposed at a substantially central portion of the Z tilt stage 52. Around the substrate P, a plate member 56 having a flat surface 57 that is almost the same height (level) as the surface of the substrate P is provided. The plate member 56 is an annular member and is disposed so as to surround the substrate P held by the substrate holder.

  A reference member 300 is disposed at a predetermined position outside the plate member 56 on the Z tilt stage 52 (substrate stage PST). The reference member 300 is provided with a reference mark PFM detected by the substrate alignment system and a reference mark MFM detected by the mask alignment system 360 in a predetermined positional relationship. Further, the upper surface 301 of the reference member 300 is substantially flat, and may be used as a reference surface for a focus / leveling detection system. Further, the upper surface 301 of the reference member 300 is provided at substantially the same height (level) as the surface of the substrate P and the surface (flat surface) 57 of the plate member 56.

  Further, on the Z tilt stage 52 (substrate stage PST), an illuminance unevenness sensor 400 as disclosed in, for example, Japanese Patent Laid-Open No. 57-117238 is disposed as an optical sensor at a predetermined position outside the plate member 56. Has been. The illuminance unevenness sensor 400 includes an upper plate 402 having a rectangular shape in plan view. The upper surface 401 of the upper plate 402 is substantially flat and is provided at substantially the same height (level) as the surface of the substrate P and the surface (flat surface) 57 of the plate member 56. A pinhole portion 403 through which light can pass is provided on the upper surface 401 of the upper plate 402. Of the upper surface 401, the portions other than the pinhole portion 403 are covered with a light shielding material such as chromium.

  Further, an aerial image measurement sensor 500 as disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-14005 is provided as an optical sensor at a predetermined position outside the plate member 56 on the Z tilt stage 52 (substrate stage PST). Is provided. The aerial image measurement sensor 500 includes an upper plate 502 having a rectangular shape in plan view. The upper surface 501 of the upper plate 502 is substantially flat and may be used as a reference surface for a focus / leveling detection system. The upper surface 501 of the upper plate 502 is provided at substantially the same height (level) as the surface of the substrate P and the surface (flat surface) 57 of the plate member 56. On the upper surface 501 of the upper plate 502, a slit portion 503 capable of passing light is provided. Of the upper surface 501, the portions other than the slit portion 503 are covered with a light shielding material such as chromium.

  Although not shown, an irradiation amount sensor (illuminance sensor) as disclosed in, for example, Japanese Patent Application Laid-Open No. 11-16816 is also provided on the Z tilt stage 52 (substrate stage PST). The upper surface of the upper plate of the irradiation amount sensor is provided at substantially the same height (level) as the surface of the substrate P and the surface (flat surface) 57 of the plate member 56.

  The exposure apparatus EX in the present embodiment projects and exposes a pattern image of the mask M onto the substrate P while moving the mask M and the substrate P in the X-axis direction (scanning direction). A pattern image of a part of the mask M is projected into the projection area AR1 via the liquid LQ in the area AR2 and the projection optical system PL, and is synchronized with the movement of the mask M in the −X direction (or + X direction) at the velocity V. Then, the substrate P moves in the + X direction (or −X direction) with respect to the projection area AR1 at the speed β · V (β is the projection magnification). Then, a plurality of shot areas are set on the substrate P, and after the exposure to one shot area is completed, the next shot area is moved to the scanning start position by the stepping movement of the substrate P. Hereinafter, step-and-scan The scanning exposure process for each shot area is sequentially performed while moving the substrate P by the method.

  As shown in FIG. 2, the projection area AR1 of the projection optical system PL is set in a rectangular shape in plan view with the Y axis direction as the long direction and the X axis direction as the short direction. In addition, it is preferable that the width | variety of the flat surface 57 currently formed in the annular | circular shape among the plate members 56 is formed at least larger than the projection area | region AR1. Thereby, when the edge region E of the substrate P is exposed, the exposure light EL is not irradiated to the outside of the plate member 56. Furthermore, the width of the flat surface 57 is preferably larger than the liquid immersion area AR2 formed on the image plane side of the projection optical system PL. Thus, when the edge area E of the substrate P is subjected to immersion exposure, the immersion area AR2 is disposed on the flat surface 57 of the plate member 56 and is not disposed outside the plate member 56. The occurrence of inconvenience such as the liquid LQ flowing out of the plate member 56 can be prevented.

  Further, the liquid immersion area AR2 filled with the liquid LQ is substantially in a region surrounded by the two liquid recovery ports 23A and 23B so as to include the projection area AR1 and locally on a part of the substrate P. Formed. The liquid immersion area AR2 only needs to cover at least the projection area AR1, and the entire area surrounded by the two liquid recovery ports 23A and 23B may not necessarily become the liquid immersion area.

  The liquid supply ports 13A and 13B are provided on both sides in the scanning direction (X-axis direction) with respect to the projection area AR1 on the lower surface 70A of the flow path forming member 70 facing the substrate P. Specifically, the liquid supply port 13A is provided on one side (−X side) in the scanning direction with respect to the projection area AR1 on the lower surface 70A of the flow path forming member 70, and the liquid supply port 13B is on the other side (+ X). Side). That is, the liquid supply ports 13A and 13B are provided near the projection area AR1, and are provided on both sides of the projection area AR1 with respect to the scanning direction (X-axis direction). Each of the liquid supply ports 13 </ b> A and 13 </ b> B is formed in a slit shape having a substantially U-shape (arc shape) in plan view extending in the Y-axis direction. The lengths of the liquid supply ports 13A and 13B in the Y-axis direction are at least longer than the length of the projection area AR1 in the Y-axis direction. The liquid supply ports 13A and 13B are provided so as to surround at least the projection area AR1. The liquid supply mechanism 10 can simultaneously supply the liquid LQ on both sides of the projection area AR1 via the liquid supply ports 13A and 13B.

  The liquid recovery ports 23A and 23B are provided outside the liquid supply ports 13A and 13B of the liquid supply mechanism 10 with respect to the projection region AR1 on the lower surface 70A of the flow path forming member 70 facing the substrate P. It is provided on both sides of the scanning direction (X-axis direction) with respect to AR1. Specifically, the liquid recovery port 23A is provided on one side (−X side) in the scanning direction with respect to the projection area AR1 on the lower surface 70A of the flow path forming member 70, and the liquid recovery port 23B is on the other side (+ X). Side). Each of the liquid recovery ports 23A and 23B is formed in a slit shape having a substantially U-shape (arc shape) in plan view extending in the Y-axis direction. The liquid recovery ports 23A and 23B are provided so as to surround the liquid supply ports 13A and 13B.

  In addition, although the liquid supply port 13 is the structure provided one each on both sides of the projection area | region AR1, it may be divided | segmented into plurality and the number is arbitrary. Similarly, the liquid recovery port 23 may also be divided into a plurality.

  In addition, although the liquid supply ports 13 provided on both sides of the projection area AR1 are formed with substantially the same size (length), they may have different sizes. Similarly, the liquid recovery ports 23 provided on both sides of the projection area AR1 may have different sizes.

  In addition, the slit width of the supply port 13 and the slit width of the recovery port 23 may be the same, or the slit width of the recovery port 23 may be larger than the slit width of the supply port 13, or conversely. The slit width of the port 23 may be smaller than the slit width of the supply port 13.

  FIG. 3 is a plan view schematically showing a state in which the detection light La is applied to the immersion area AR2 of the liquid LQ formed on the substrate P. FIG. As described above, the irradiation area of the detection light La is larger than the projection area AR1 (irradiation area of the exposure light EL) of the projection optical system PL and larger than the liquid immersion area AR2. Further, the gas detection system 40 has a light receiving system 42 that receives light via the liquid LQ in the liquid immersion area AR2. The light receiving system 42 is provided on the side of the liquid immersion area AR2 of the liquid LQ, and includes a mirror 80 that bends the optical path of light from the liquid LQ, a lens system 81 that condenses the light via the mirror 80, and a lens system 81. And a light receiving element 82 for receiving light via the. As the light receiving element 82, a charge coupled device (CCD) or a photomultiplier tube can be used. In the present embodiment, the light receiving element 82 is constituted by a charge coupled device (CCD).

  In the present embodiment, the projection system 41 irradiates the substrate P (the liquid immersion area AR2) with the detection light La from the −X side. The light receiving system 42 is disposed at a position where the detection light La from the projection system 41 does not directly enter, specifically, at a position other than facing the projection system 41. In the present embodiment, the substrate P (immersion area AR2). ) To the + Y side.

  When there is no bubble (gas portion) in the liquid immersion area AR2 of the liquid LQ, the detection light La irradiated by the projection system 41 passes through the liquid LQ in the liquid immersion area AR2 and is not received by the light receiving system. On the other hand, as shown in FIG. 3, when the bubble 100 which is a gas part exists in the liquid LQ of the liquid immersion area AR2, the detection light La irradiated to the liquid immersion area AR2 from the projection system 41 enters the bubble 100. It hits and scatters. Scattered light generated when the detection light La strikes the bubble 100 is received by the light receiving element 82 via the mirror 80 and the lens system 81 of the light receiving system 42. In this way, the gas detection system 40 can detect the presence or absence of the bubble (gas portion) 100 in the liquid immersion area AR2 based on the light reception result of the light receiving system 42, and when the light receiving element 82 receives light, It is determined that the bubble 100 is present in the liquid LQ in the area AR2.

  Here, the scattered light generated when the detection light La hits the bubble 100 depends on the size and shape of the bubble 100. Since the bubbles 100 are often several μm in size, the scattered light exhibits a so-called Mie scattering aspect.

  Mie scattering varies depending on the size of the detection target (in this case, the bubble 100), the refractive index, the wavelength of the light (in this case, the detection light La), and the like. In the present embodiment, since the wavelength of the detection light La is constant, the light intensity of the scattered light generated in the bubble 100 and the amount of light received by the light receiving element 82 change according to the size of the bubble 100. . Specifically, when the bubble 100 is large, the amount of light received by the light receiving element 82 increases, and when the bubble 100 is small, the amount of light received by the light receiving element 82 also decreases. Therefore, the size of the bubble 100 can be estimated based on the light intensity of the scattered light generated in the bubble 100, that is, the amount of light received by the light receiving element 82 (light receiving system 42).

  In the case of Mie scattering, the direction in which the light intensity of scattered light generated from the bubble 100 when the bubble 100 is irradiated with light from a predetermined direction is specified is specified. In the present embodiment, when the detection light La is irradiated from the −X direction to the bubble 100, the direction in which the light intensity of the scattered light generated from the bubble 100 is the strongest is the + Y direction. Therefore, the scattered light generated from the bubble 100 can be detected (received) by disposing the light receiving system 42 (mirror 80) at a position away from the bubble 100 (immersion area AR2) in the + Y direction.

  Further, the gas detection system 40 can also determine the amount of bubbles 100 per unit area in the liquid immersion area AR2 based on the intensity of light received by the light receiving system 42 (light reception amount).

Next, a procedure for exposing the pattern of the mask M onto the substrate P through the projection optical system PL and the liquid LQ using the exposure apparatus EX having the above-described configuration will be described.
After the mask M is loaded on the mask stage MST and the substrate P is loaded on the substrate stage PST, the controller CONT drives the liquid supply mechanism 10 and the liquid recovery mechanism 20 to supply the liquid LQ on the substrate P and A recovery operation is performed to form a liquid LQ immersion area AR2 on the substrate P.

  When the operation of forming the immersion area AR2 of the liquid LQ on the substrate P is performed before the exposure processing of the substrate P is started, the control device CONT supplies the detection light La from the projection system 41 of the gas detection system 40. Irradiate the liquid LQ in the immersion area AR2. Then, the control device CONT determines whether or not the exposure operation start for the substrate P is appropriate based on the detection result of the gas detection system 40. That is, in the liquid immersion area forming operation before the exposure process, when there is a bubble 100 in the liquid LQ of the liquid immersion area AR2, the control device CONT determines whether the liquid immersion area is based on the output of the light receiving system 42 of the gas detection system 40. It is determined that there is a bubble 100 in the AR, and it is determined that it is inappropriate to start the immersion exposure process. Then, the control device CONT continues the supply and recovery operation of the liquid LQ by the liquid supply mechanism 10 and the liquid recovery mechanism 20 until the bubbles 100 in the liquid LQ in the liquid immersion area AR2 disappear, or the liquid of the liquid supply mechanism 10 Appropriate measures are taken to eliminate the bubbles 100, such as changing the supply amount and the liquid recovery amount of the liquid recovery mechanism 20, or changing the immersion region forming operation conditions such as moving the position of the substrate P. When the control device CONT determines that there is no bubble 100 in the liquid LQ in the liquid immersion area AR2 based on the detection result of the gas detection system 40, the control device CONT determines that it is appropriate to start the liquid immersion exposure process. . The control device CONT that determines that it is appropriate to start the immersion exposure process starts the exposure light EL and performs the exposure process.

  The controller CONT drives the substrate stage PST to scan the substrate P in the X-axis direction, illuminates the mask M with the exposure light EL from the illumination optical system IL, and projects the pattern of the mask M onto the projection optical system PL and the liquid Projection exposure is performed on the substrate P through the LQ. While the substrate P is being exposed, the control device CONT performs detection by the gas detection system 40 in parallel with the exposure of the substrate P.

  The gas detection system 40 irradiates detection light (laser sheet light) La substantially parallel to the surface of the substrate P so as to cover almost the entire immersion area AR2 of the liquid LQ between the projection optical system PL and the substrate P. Therefore, the presence / absence of the bubble 100 can be collectively detected in a wide range of the liquid immersion area AR2. In particular, since the detection light La is irradiated from the side to the liquid LQ in the liquid immersion area AR2, the gas detection system 40 can detect the bubbles 100 floating in the liquid LQ satisfactorily.

  Further, the irradiation area of the detection light La is set to be larger than the distance WD between the liquid contact surface 2A of the projection optical system PL and the substrate P, and further larger than the liquid immersion area AR2. Therefore, the gas detection system 40 simultaneously irradiates each of the liquid contact surface 2A of the projection optical system PL, the liquid contact surface 70A of the flow path forming member 70, and the surface (liquid contact surface) of the substrate P with the detection light La. Is possible. Therefore, in addition to the bubble 100 floating in the liquid LQ, each of the liquid contact surface 2A of the projection optical system PL, the liquid contact surface 70A of the flow path forming member 70, and the surface (liquid contact surface) of the substrate P The adhering bubble 100 can also be detected well.

  Even in the liquid immersion area forming operation before the exposure process, the gas detection system 40 includes the bubbles 100 floating in the liquid LQ in the liquid immersion area AR2, the liquid contact surface 2A of the projection optical system PL, and the flow path forming member. Needless to say, the bubble 100 attached to each of the 70 liquid contact surfaces 70 </ b> A and the surface (liquid contact surface) of the substrate P can also be detected.

  Further, when the detection by the gas detection system 40 is performed in parallel with the exposure of the substrate P, the control device CONT continues the exposure on the substrate P based on the detection result of the gas detection system 40 (light receiving system 42). Determine whether or not. For example, when the gas detection system 40 detects the bubble 100, the exposure process is stopped.

  Further, as described above, the intensity of light received by the light receiving system 42 changes according to the size of the bubble 100. Therefore, when the detection by the gas detection system 40 is performed in parallel with the exposure of the substrate P, the control device CONT determines whether or not to continue the exposure to the substrate P based on the light intensity received by the light receiving system 42. It can also be judged.

  Here, the control device CONT stores allowable value information regarding the bubble 100 indicating whether or not the pattern is transferred to the substrate P with a desired pattern transfer accuracy. This allowable value includes an allowable value related to the size of the bubble 100 or the amount (number) of the bubbles 100 for one shot region. Furthermore, the relationship between the received light intensity and the allowable value is also stored. For example, when the bubble 100 having a small diameter is slightly floating in the liquid LQ, a desired pattern transfer accuracy may be obtained even when the bubble 100 is present in the liquid LQ. In this case, even if the bubble 100 is detected by the gas detection system 40, the intensity of the light received at that time is very small, so the control device CONT continues to expose the substrate P. On the other hand, when the received light intensity is higher than the light intensity corresponding to the above-described allowable value, the control device CONT interrupts the exposure processing operation or drives an alarm device (not shown), for example, to generate bubbles above the allowable value. A measure such as notification that 100 exists is performed.

  As described above, by detecting the presence or absence of the bubble (gas portion) 100 in the liquid LQ in the liquid immersion area AR2 formed on the substrate P by the gas detection system 40, for example, during the exposure of the substrate P, It is possible to grasp whether or not a pattern image formation failure or a defective shot has occurred due to the bubble 100, and appropriate measures can be taken to maintain high device productivity. Further, since it is possible to start exposure of the substrate P after confirming that there is no gas portion in the optical path of the exposure light EL, it is possible to suppress the occurrence of defective devices. The gas detection system 40 projects detection light (laser sheet light) La substantially parallel to the surface of the substrate P onto the liquid immersion area AR2 of the liquid LQ formed on the substrate P. The presence / absence of a gas portion can be collectively detected in a wide range.

  In the embodiment described above, the gas detection system 40 detects the bubble 100. However, not only a small gas portion such as the bubble 100 but also a relatively large gas space (gas portion) is present in the liquid LQ. In some cases, the gas may remain on the image plane side of the projection optical system PL when the liquid LQ is generated or when the supply of the liquid LQ is started from the liquid supply mechanism 10. Also in such a case, since the detection light La is scattered in the gas portion and the scattered light enters the light receiving system 42, the presence or absence of the gas portion on the image plane side of the projection optical system PL is determined based on the light reception result of the light receiving system 42. Can be detected.

  In the above-described embodiment, the irradiation area of the detection light La by the projection system 41 of the gas detection system 40 is larger than the liquid immersion area AR2, but exists in the optical path of the exposure light EL including the projection area AR1 of the projection optical system PL. By detecting the bubbles 100 to be generated, it is possible to prevent the pattern image transferred to the substrate P from being deteriorated. Therefore, it is sufficient that the irradiation area of the detection light La is at least larger than the projection area AR1 (the irradiation area of the exposure light EL). On the other hand, since the irradiation area of the detection light La is made larger than the liquid immersion area AR2, it is possible to detect the bubble 100 existing at a position other than the optical path of the exposure light EL in the liquid LQ of the liquid immersion area AR2. For example, during scanning exposure, the bubble 100 existing at a position other than the optical path of the exposure light EL moves in the liquid LQ with the movement of the substrate P and is disposed on the optical path of the exposure light EL, or on the substrate P or the optical element 2. Even if there is a possibility of adhering, the gas detection system 40 causes the bubble 100 existing at a position other than the optical path of the exposure light EL to be placed on the optical path of the exposure light EL or before adhering to the substrate P or the optical element 2. In addition, the bubble 100 can be detected. Therefore, during the exposure process, for example, the bubble 100 is exposed based on the output of the gas detection system 40 before the bubble 100 floating in the liquid LQ is placed on the optical path of the exposure light EL or the substrate P. It is predicted that the light EL will be placed on the optical path or the substrate P, and appropriate measures such as stopping the exposure process or driving an alarm device can be taken, resulting in exposure failure or defective shot. Inconvenience can be avoided.

  In the above-described embodiment, the light receiving system 42 is disposed at a position other than facing the projection system 41. When the light receiving system 42 is located at a position facing the projection system 41, the possibility that the detection light La emitted from the projection system 41 is directly incident on the light receiving system 42 is increased, and the directly incident detection light La is received by the light receiving system 42. This is a noise component. However, by disposing the light receiving system 42 at a position other than facing the projection system 41, it is possible to prevent inconvenience that the detection light La emitted from the projection system 41 is directly incident on the light receiving system 42.

  In the embodiment described above, the projection system 41 irradiates the detection light La from the X-axis direction (scanning direction) to the substrate P (immersion area AR2), but from the Y-axis direction (non-scanning direction). You may make it irradiate. That is, it is only necessary to irradiate the liquid immersion area AR2 with the detection light La substantially parallel to the surface of the substrate P, and irradiation can be performed from any of the radial directions with respect to the optical axis AX of the projection optical system PL.

  In the embodiment described above, there is one projection system 41, and the detection light La is irradiated from one place to the liquid immersion area AR2. However, a plurality of projection systems 41 are provided, and the liquid immersion area AR2 is provided. Alternatively, the detection light La may be irradiated from each of a plurality of positions (directions).

  Further, in the present embodiment, the detection light La having a wavelength different from that of the exposure light EL is irradiated, but scattered light generated when the exposure light EL hits the bubble 100 is received by the light receiving system 42. Is also possible. On the other hand, by irradiating the detection light La different from the exposure light EL, the bubble detection operation can be performed at a timing other than the exposure process.

  In the above-described embodiment, the case where the liquid immersion area AR2 is formed on the substrate P has been described. However, the reference member 300 on the substrate stage PST (Z tilt stage 52) as described with reference to FIG. The liquid LQ immersion region AR2 may be formed on the upper surface 301, the upper surface 401 of the upper plate 402 of the illuminance unevenness sensor 400, the upper surface 501 of the upper plate 502 of the aerial image measurement sensor 500, and the upper surface of the upper plate of the irradiation amount sensor. Conceivable. When measurement is performed via the liquid LQ with such a reference member or sensor, if there is a possibility that a measurement error may occur if the gas portion (bubble) 100 exists on the image plane side of the projection optical system PL, gas detection is performed. The presence or absence of a gas portion may be detected using the system 40.

Hereinafter, another embodiment of the present invention will be described with reference to FIG. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
In FIG. 4, the gas detection system 40 includes a first light receiving system 42 </ b> A and a second light receiving system 42 </ b> B provided at different positions that receive light via the liquid LQ. Scattered light generated when the detection light La emitted from the projection system 41 strikes the bubble 100 is incident on each of the first and second light receiving systems 42A and 42B. Each of the light receiving elements 82A and 82B of the first and second light receiving systems 42A and 42B is constituted by a CCD.

  As described above, the direction in which the light intensity of the scattered light generated from the bubble 100 when the bubble 100 is irradiated with light from a predetermined direction is specified, and the first and second positions corresponding to the direction are specified. Light receiving systems 42A and 42B are arranged. The scattered light generated from the bubble 100 is incident on the light receiving surfaces of the light receiving elements 82A and 82B. The scattered light is incident on a position on the light receiving surface corresponding to the position of the bubble 100 on the liquid immersion area AR2 (on the substrate P).

  Each of the light receiving elements 82A and 82B is configured by a one-dimensional CCD capable of specifying a light receiving position in the XY direction (horizontal direction) on the light receiving surface. Further, the scattered light has a peak value, and the light receiving elements 82A and 82B specify the light receiving position in the XY directions on the light receiving surface based on the peak value of the scattered light. That is, when the position of the bubble 100 on the XY plane changes, the light receiving position of the scattered light by the light receiving elements 82A and 82B also changes as indicated by arrows S1 and S2 in FIG. Therefore, the gas detection system 40 can obtain position information on the XY plane of the bubble 100 based on the light receiving positions on the light receiving surfaces of the light receiving elements 82A and 82B of the first and second light receiving systems 42A and 42B. it can.

  Here, each of the light receiving elements 82A and 82B is configured by a one-dimensional CCD capable of specifying a light receiving position in the XY direction (horizontal direction) on the light receiving surface. A position of 100 in the Z-axis direction can also be obtained.

  By obtaining the position of the bubble 100 on the liquid immersion area AR2 (substrate P), the distance between each of the light receiving elements 82A and 82B and the bubble 100 can be derived. Further, the light intensity of the scattered light generated in the bubble 100 and the light intensity (the amount of received light) received by the light receiving elements 82A and 82B change according to the size of the bubble 100. The intensity of light received by the light receiving elements 82A and 82B also changes depending on the distance between each of the light receiving elements 82A and 82B and the bubble 100.

  Therefore, the control device CONT obtains the size of the bubble 100 based on the information regarding the distance between each of the light receiving elements 82A and 82B and the bubble 100 and the light intensity received by the light receiving elements 82A and 82B. Can do.

  Specifically, the relationship (characteristic curve) between the size of the bubble 100 and the light intensity received by the light receiving elements 82A and 82B is obtained in advance by experiments, simulations, or the like. Further, the relationship (characteristic curve) is obtained in association with a plurality of the distances. The obtained information is stored in the control device CONT.

  Then, the control device CONT determines the position of the bubble 100 based on the positional information of the bubble 100 detected using the gas detection system 40 (and thus the information on the distance), the light intensity received at that time, and the stored information. The size can be determined.

  And the control apparatus CONT controls the operation | movement regarding exposure based on at least any one among the magnitude | size and position of the bubble 100 which were calculated | required. For example, threshold information about the bubble 100 indicating whether or not the pattern is transferred to the substrate P with a desired pattern transfer accuracy is stored in the control device CONT in advance. This threshold value includes a threshold value related to the size of the bubble 100 and a threshold value related to the position of the bubble 100. Then, the control device CONT compares the stored threshold information with the detection result of the size or position of the bubble 100. The control device CONT determines whether or not the detection result of the bubble 100 by the gas detection system 40 is equal to or greater than the threshold value. For example, when the bubble 100 having a small diameter is slightly floating in the liquid LQ, a desired pattern transfer accuracy may be obtained even when the bubble 100 is present in the liquid LQ. Therefore, a threshold value regarding the amount and size of the bubble 100 is obtained in advance, and it can be determined that the exposure of the substrate P can be appropriately performed if the detection result of the gas detection system 40 is equal to or less than the threshold value. In this case, even if the bubble 100 is detected by the gas detection system 40, the control device CONT continues to expose the substrate P. On the other hand, when it is determined that the detected bubble 100 is equal to or greater than the threshold value, the control device CONT, for example, interrupts the exposure processing operation or drives an alarm device (not shown) to exceed the allowable range ( A measure such as notification that the bubble 100 of the threshold value or more is present is performed.

  Alternatively, the control device CONT detects the position of the bubble 100 during the exposure of each of the plurality of shot areas on the substrate P, and the pattern image is not properly formed by the bubbles 100 among the plurality of shot areas. Memorize the shot area. Then, after the exposure process is completed, a shot area in which a pattern image is not properly formed out of a plurality of shot areas based on the stored information is obtained from the subsequent exposure process of another layer. Excluded or re-exposed after re-applying resist. Furthermore, there is a difference in the degree of pattern degradation between the case where the bubble 100 is adhered on the substrate P and the case where the bubble 100 is floating in the tip surface of the projection optical system PL or the liquid LQ. Even in that case, the subsequent processing may be determined according to the position where the bubble 100 exists.

  In each of the above-described embodiments, the case where the gas detection system 40 is applied to the local liquid immersion method in which the liquid immersion area AR2 is locally formed on a part of the substrate P has been described as an example. As shown, the substrate stage PST holding the substrate P can be applied to a so-called global liquid immersion method in which the substrate stage PST is moved in the liquid tank 90. FIG. 5A is a side view showing an example of the global immersion exposure apparatus, and FIG. 5B is a plan view. In FIG. 5, the liquid tank 90 includes an incident window 91 through which the detection light La from the projection system 41 can pass, and an exit window 92 through which scattered light generated from the bubble 100 can pass. As an immersion exposure apparatus to which the global immersion method is applied, for example, a configuration disclosed in JP-A-6-124873 can be employed.

  6 is a side view showing another embodiment of the present invention, and FIG. 7 is a view of the liquid immersion area AR2 of FIG. 6 as viewed from below. In FIG. 6, the projection system 41 that projects the detection light La in the gas detection system 40 first guides the detection light La from the upper position of the liquid immersion area AR2 of the liquid LQ formed on the substrate P downward. A light transmission system 74 and an optical path bending mirror 76 that makes the detection light La from the first light transmission system 74 substantially parallel to the surface of the substrate P are provided. The light source 43, pinhole 44, collimator lens 45, beam expander 46, first and second cylindrical lenses 48, 49, etc. described with reference to FIG. 1 and the like are provided above the immersion area AR2. The laser sheet light La, which is detection light, is guided by the first light transmission system 74 from the upper position to the lower position of the liquid immersion area AR2.

  The first light transmission system 74 is configured by an optical fiber bundle in which a plurality of optical fibers are bundled, and a part of the first light transmission system 74 is disposed inside the flow path forming member 70. The exit end of the optical fiber bundle (first light transmission system) 74 is immersed in the liquid LQ in the liquid immersion area AR2. A cylindrical lens (see reference numeral 75) for forming laser sheet light may be disposed on the exit end side of the optical fiber bundle 74. The cylindrical lens 75 is also immersed in the liquid LQ in the immersion area AR2.

  The mirror 76 is attached to the lower surface 70 </ b> A of the flow path forming member 70 via a support member 77. The mirror 76 is also immersed in the liquid LQ in the immersion area AR2.

  Of the gas detection system 40, the light receiving system 42 that receives light includes an optical path bending mirror 78 that guides light through the liquid LQ upward of the liquid immersion area AR2, and a lens system 85 that guides light from the mirror 78 to the light receiving element 86. And.

  The lens system 85 is attached to the flow path forming member 70, and the light receiving end where the light from the mirror 78 is incident is immersed in the liquid LQ in the liquid immersion area AR2. The light receiving element 86 is provided above the flow path forming member 70, and the flow path forming member 70 is formed with a through-hole 87 for securing an optical path of light from the lens system 85 toward the light receiving element 86. ing.

  Further, the mirror 78 constituting a part of the light receiving system 42 is attached to the lower surface 70 </ b> A of the flow path forming member 70 via a support member 79. The mirror 78 is also immersed in the liquid LQ in the immersion area AR2.

  As described above, among the plurality of members constituting the gas detection system 40, the support members 77 and 79, the mirrors 76 and 78, or the emission end of the optical fiber bundle 74 and the light reception end of the lens system 85 are liquid in the liquid immersion area AR2. I'm immersed in LQ. In the form in which the detection light La is incident on the liquid LQ in the liquid immersion area AR2 from the outside of the liquid LQ via the air, the detection light La is scattered at the interface between the liquid LQ and the air, and the bubble detection accuracy deteriorates. Although this may occur, as in the present embodiment, a specific member among a plurality of members constituting the gas detection system 40 is immersed in the liquid LQ in the liquid immersion area AR2, and the detection light La is supplied to the liquid LQ and air. The occurrence of the above inconveniences can be prevented by not passing through the interface.

  The projection system 41 and the light receiving system 42 are respectively provided on both sides of the projection area AR1 of the projection optical system PL. Further, as shown in FIG. 7, the liquid supply ports 13A and 13B for supplying the liquid LQ are provided at positions separated in the X-axis direction with respect to the projection area AR1 of the projection optical system PL. Of the plurality of members constituting the projection system 41 and the light receiving system 42, at least a member immersed in the liquid LQ, that is, the exit end of the optical fiber bundle 74, mirrors 76 and 78, support members 77 and 79, and The light receiving end of the lens system 85 is provided at a position separated in a direction different from the X-axis direction. In the example shown in FIG. 7, the member immersed in the liquid LQ is provided at a position substantially away from the projection area AR1 of the projection optical system PL in the Y-axis direction. With such an arrangement, it is possible to prevent inconvenience that the liquid LQ supplied from the liquid supply ports 13A and 13B hits the member and disturbs the flow of the liquid LQ in the liquid immersion area AR2. In the example shown in FIG. 7, the mirror 78 constituting a part of the light receiving system 42 is provided at a position where the detection light La emitted from the optical fiber bundle 74 and passed through the mirror 76 is not directly incident.

  As described above, it is also possible to use the optical fiber bundle 74 to guide the detection light La downward from the upper position of the liquid immersion area AR2 and make the detection light La incident from above the liquid immersion area AR2. By doing so, even if other devices and members exist around the projection optical system PL, the substrate P, etc., and the arrangement of the optical system of the gas detection system 40 is restricted, the gas detection system 40 is provided by the optical fiber bundle 74. The degree of freedom of arrangement of the optical system is improved. Therefore, even if there is the restriction, the detection light La from the optical fiber bundle 74 is smoothly projected almost parallel to the surface of the substrate P via the mirror 76. Since the detection light La that is substantially parallel to the surface of the substrate P is projected onto the liquid immersion area AR2 of the liquid LQ formed on the substrate P, the presence / absence of the bubble 100 is collectively determined in a wide range of the liquid immersion area AR2. Can be detected.

  In the above-described embodiment, the optical fiber bundle 74 is used to allow the detection light La to enter from above the liquid immersion area AR2. However, of course, a lens system may be used, or a space may be propagated. I do not care. In addition to the configuration in which the scattered light generated in the bubble 100 is emitted from above the liquid immersion area AR2, the scattered light may be guided in other directions such as a lateral direction.

  As described above, the liquid LQ in the present embodiment is composed of 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.

  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.

  As described above, when the liquid immersion method is used, the numerical aperture NA of the projection optical system may be 0.9 to 1.3. 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 or an oblique incidence illumination method (particularly a die ball illumination method) or the like according to the longitudinal direction of the line pattern as disclosed in JP-A-6-188169.

  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 chrome), 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. Since the diffracted light of the S-polarized component (TE-polarized component) is emitted from the mask M more than the diffracted light of the component), it is desirable to use the above-mentioned linearly polarized illumination, but the mask M is illuminated with random polarized light Even when the numerical aperture NA of the projection optical system PL is as large as 0.9 to 1.3, high 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 a mask (reticle) pattern includes not only a line pattern extending in a predetermined direction but also a plurality of line patterns extending in different directions, the same is disclosed in Japanese Patent Laid-Open No. 6-53120. In addition, by using the polarization illumination method that linearly polarizes in the tangential direction of the circle centered on the optical axis and the annular illumination method, high imaging performance can be obtained even when the numerical aperture NA of the projection optical system is large. it can.

  In the present embodiment, the optical element 2 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. 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 present 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, the liquid with the cover glass made of a plane-parallel plate attached to the surface of the substrate P is used. The structure which satisfy | fills LQ may be sufficient.

The liquid LQ of the present embodiment is water, but may be a liquid other than water. For example, when the light source of the exposure light EL is an F ₂ laser, the F ₂ laser light does not pass through water. The liquid LQ may be, for example, a fluorinated fluid such as perfluorinated polyether (PFPE) or fluorinated oil that can transmit F ₂ laser light. 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. The present invention can also be applied to a step-and-stitch type exposure apparatus that partially transfers at least two patterns on the substrate P.

  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.

  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.

  When using a linear motor (see USP5,623,853 or USP5,528,118) for the substrate stage PST and mask stage MST, use either an air levitation type using air bearings or a magnetic levitation type using Lorentz force or reactance force. Also good. Each stage PST, MST may be a type that moves along a guide, or may be a guideless type that does not have a guide.

  As a driving mechanism for each stage PST, MST, a planar motor that drives each stage PST, MST by electromagnetic force with a magnet unit having a two-dimensionally arranged magnet and an armature unit having a two-dimensionally arranged coil facing each other is provided. It may be used. In this case, either one of the magnet unit and the armature unit may be connected to the stages PST and MST, and the other of the magnet unit and the armature unit may be provided on the moving surface side of the stages PST and MST.

As described in JP-A-8-166475 (USP 5,528,118), the reaction force generated by the movement of the substrate stage PST is not transmitted to the projection optical system PL, but mechanically using a frame member. You may escape to the floor (ground).
As described in JP-A-8-330224 (US S / N 08 / 416,558), a frame member is used so that the reaction force generated by the movement of the mask stage MST is not transmitted to the projection optical system PL. May be mechanically released to the floor (ground).

  As described above, the exposure apparatus EX according to the present embodiment 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. 8, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for manufacturing 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 dicing process, bonding process, packaging process) 205, inspection step 206, etc. It is manufactured after.

It is a schematic block diagram which shows one Embodiment of the exposure apparatus of this invention. It is a top view of a substrate stage. It is a top view which shows one Embodiment of the exposure apparatus of this invention. It is a top view which shows another embodiment of the exposure apparatus of this invention. It is a top view which shows another embodiment of the exposure apparatus of this invention. It is a top view which shows another embodiment of the exposure apparatus of this invention. It is the figure which looked at the liquid immersion area | region of FIG. 6 from the bottom. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.

Explanation of symbols

2 ... optical element, 2A ... liquid contact surface, 10 ... liquid supply mechanism,
13 (13A, 13B) ... liquid supply port, 20 ... liquid recovery mechanism,
23 (23A, 23B) ... liquid recovery port, 40 ... gas detection system, 41 ... projection system,
42 (42A, 42B) ... light receiving system, 70 ... flow path forming member (supply member, recovery member),
70A ... Liquid contact surface, 74 ... Optical fiber bundle (first light transmission system),
76: Mirror (second light transmission system), 78 ... Mirror (third light transmission system),
85 ... Lens system (fourth light transmission system), 86 ... Light receiving element, 100 ... Bubble (gas part),
AR1 ... projection area, AR2 ... immersion area, CONT ... control device, EL ... exposure light,
EX ... exposure apparatus, La ... detection light, LQ ... liquid, P ... substrate, PL ... projection optical system

Claims (21)

In an exposure apparatus that forms a liquid immersion area on a substrate and irradiates the substrate with exposure light via a projection optical system and the liquid to expose the substrate.
Comprising a gas detection system for optically detecting the presence or absence of a gas portion in the immersion region;
The exposure apparatus according to claim 1, wherein the gas detection system projects detection light substantially parallel to the substrate surface to the immersion area.   The exposure apparatus according to claim 1, wherein the detection light is irradiated so as to cover an area of a predetermined size or more in the liquid immersion area.   3. An exposure apparatus according to claim 1, wherein the detection light includes laser sheet light.   The exposure apparatus according to claim 1, wherein an irradiation area of the detection light is larger than a distance between an image plane side end of the projection optical system and the substrate.   The exposure apparatus according to claim 1, wherein an irradiation area of the detection light is larger than an irradiation area of the exposure light.   6. The exposure apparatus according to claim 1, wherein the detection light irradiation area is larger than the liquid immersion area. A supply member having a supply port for supplying the liquid;
A recovery member having a recovery port for recovering the liquid;
The gas detection system irradiates at least one liquid contact surface among the supply member, the recovery member, the projection optical system, and the substrate with the detection light. The exposure apparatus according to any one of the above. The gas portion includes bubbles;
The gas detection system includes at least two light receiving systems provided at different positions for receiving light via the liquid,
The exposure apparatus according to claim 1, wherein position information of the bubbles is obtained based on a light reception result of each of the light receiving systems.   9. The exposure apparatus according to claim 8, wherein the size of the bubble is obtained based on the position information and the intensity of light received by the light receiving system.   The exposure apparatus according to claim 9, wherein an operation related to exposure is controlled based on at least one of the obtained bubble size and position. Detection by the gas detection system is performed in parallel with exposure of the substrate,
The exposure apparatus according to any one of claims 1 to 10, wherein it is determined whether or not to continue the exposure based on a detection result of the gas detection system.   12. The exposure apparatus according to claim 1, wherein whether or not an exposure operation is started for the substrate is determined based on a detection result of the gas detection system. Of the gas detection system, the projection system that projects the detection light is
A first light transmission system that guides the detection light downward from an upper position of the immersion area;
The exposure apparatus according to claim 1, further comprising a second light transmission system that makes the detection light from the first light transmission system substantially parallel to the surface of the substrate. Among the gas detection systems, the light receiving system that receives light is:
A third light transmission system that guides light through the liquid to above the immersion area;
The exposure apparatus according to claim 1, further comprising a fourth light transmission system that guides light from the third light transmission system to a light receiving element. In an exposure apparatus that forms a liquid immersion area on a substrate and irradiates the substrate with exposure light via a projection optical system and the liquid to expose the substrate.
Comprising a gas detection system for optically detecting the presence or absence of a gas portion in the immersion region;
The gas detection system includes a projection system that projects the detection light onto the liquid;
A light receiving system for receiving light through the liquid,
The projection system includes a first light transmission system that guides the detection light downward from an upper position of the liquid immersion region, and a first light that substantially parallels the detection light from the first light transmission system to the substrate surface. An exposure apparatus comprising a two-light transmission system. The light receiving system includes a third light transmission system that guides light through the liquid to the upper side of the liquid immersion area;
16. The exposure apparatus according to claim 15, further comprising a fourth light transmission system that guides light from the third light transmission system to a light receiving element.   The exposure apparatus according to claim 1, wherein a specific member among the plurality of members constituting the gas detection system is immersed in the liquid in the liquid immersion region. The supply port for supplying the liquid is provided at a position away from the projection area of the projection optical system in a predetermined direction,
The exposure apparatus according to claim 17, wherein the member immersed in the liquid is provided at a position separated in a direction different from the predetermined direction.   16. The exposure apparatus according to claim 15, wherein the emission end for emitting the detection light of the first light transmission system and the second light transmission system are immersed in the liquid in the liquid immersion region.   The light receiving end on which light from the third light transmission system is incident among the third light transmission system and the fourth light transmission system is immersed in the liquid in the liquid immersion region. Item 16. The exposure apparatus according to Item 16.   21. A device manufacturing method using the exposure apparatus according to any one of claims 1 to 20.

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