JP2009170663A - Projection optical unit, aligner, exposure method, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify and miniaturize the configuration of an aligner, and to reduce the costs of the aligner. <P>SOLUTION: A projection optical unit PLU1 projects a pattern image of a mask R2 lit by illumination light from an illumination light source on a substrate W. The projection optical unit PLU1 includes: an optical member 25 that is provided in the optical path between the mask R2 and the substrate W and separates reflection light on the substrate W from the optical path; and a detection means B1 for detecting light separated by the optical member 25. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projection optical unit that projects an image of an illuminated mask pattern onto a substrate, an exposure apparatus including the projection optical unit, an exposure method, and a device manufacturing method using the exposure method.

  In a photolithography process for manufacturing semiconductor elements, thin film magnetic heads, and other microdevices, a reticle or mask (hereinafter collectively referred to as a reticle) on which a pattern (device pattern) to be transferred is formed is used. An exposure apparatus that exposes a substrate (photosensitive substrate) such as a wafer coated with a photoresist (photosensitive material) with light is used. The exposure apparatus includes a light source, an illumination optical system, a projection optical system, a stage, and the like, and a plurality of elements set in an array on the substrate by repeatedly performing exposure while stepping the stage on which the substrate is placed. An image of the reticle pattern is transferred to the shot area.

  As an exposure method for each shot region, there are a static exposure type that performs batch exposure while the reticle and the substrate are stationary, and a scanning exposure type that sequentially exposes the reticle and the substrate while relatively moving relative to each other.

  By the way, in a chemical mechanical polishing (CMP) process performed in a step subsequent to the photolithography step, a shot region including the entire device pattern (hereinafter, referred to as a normal shot region) on one substrate. Between the area where the pattern is arranged and the outer peripheral edge of the substrate that cannot cover the entire shot area (edge part), that is, the area where the pattern is not exposed and transferred. There is a problem that a step occurs.

  This inconvenience can be alleviated by transferring a pattern having the same density as the pattern transferred into the normal shot region or a density of the same level as the pattern transferred to the vicinity of the outer peripheral edge.

  For this reason, a shot area is also set in the vicinity of the outer peripheral edge and exposure processing is performed. Unlike the normal shot area, this shot area is a shot area that lacks a part of the shot area, or a shot area that includes the edge of the substrate, or an edge shot area. Sometimes called.

  Note that, since the chip shot area cannot include the entire device pattern, the pattern is transferred, but generally is an area that is not used as a product.

  Conventionally, the exposure process for such a missing shot area has been performed by a single exposure apparatus in the same process as the exposure process for the normal shot area. The time for processing the substrate has become longer, and the throughput (processing amount per unit time) has been reduced.

  Therefore, an exposure unit that performs exposure processing on a normal shot area, an exposure unit that performs exposure processing on a missing shot area, and two stages that can hold substrates respectively (that is, substantially two units) are provided. And a technique for performing exposure processing in parallel has been proposed (see Patent Document 1 below).

  In an exposure apparatus that performs exposure processing on such a missing shot area, similarly to an exposure apparatus that exposes a normal shot area, exposure amount control, mark detection on a substrate for alignment, and substrate detection for autofocus control are performed. It is necessary to detect the surface position and the like, and conventionally, a detection system for performing such detection and control has been mounted independently of the projection optical system. For example, Patent Document 1 describes an off-axis type as an alignment system and an oblique-incidence type as a focus detection system, which are provided in the vicinity thereof independently of the projection optical system. Yes.

  Here, the exposure processing of the missing shot area does not necessarily require as high accuracy as the normal shot area. In addition, an exposure apparatus that performs exposure processing on a shot area is considered to be attached to an exposure apparatus that normally performs exposure processing on a shot area, or to be attached to a transport device provided nearby. Therefore, there is a demand for small size and low cost.

  However, conventionally, the detection system used for exposure control, mark detection, focus control, etc. is configured and arranged separately from the projection optical system, so in order to simplify and downsize the configuration, There was a limit. Further, as a result of such separate and independent arrangement, each has to be expensive, and the number of assembly steps of the apparatus is large, which has been an obstacle to cost reduction.

  The request for simplification, miniaturization, cost reduction, etc. can be applied to the exposure unit that performs exposure processing on the normal shot area.

The present invention has been made in view of the above points, and aims to simplify, reduce the size, and reduce the cost of the configuration of an exposure apparatus. As a result, it is also an object to reduce the manufacturing cost of the device.
International Publication WO2004 / 053951 Pamphlet

  In the description of this section, reference numerals indicating members and the like shown in the drawings representing the embodiments to be described later are appended with parentheses, but this is merely for ease of understanding, and each component of the present invention is: The present invention is not limited to the members shown in the drawings with the reference numerals indicating these members.

  According to a first aspect of the present invention, there is provided a projection optical unit (PLU1 to PLU3) that projects an image of a pattern of a mask (R2) illuminated with illumination light (EL2) from an illumination light source onto a substrate (W). And an optical member (25, 27) provided in an optical path between the mask and the substrate for separating the reflected light from the substrate from the optical path, and detecting for detecting the light separated by the optical member. And a projection optical unit comprising means (B1, C6, D9).

  The optical member (25, 27) transmits one of the illumination light (EL2) and the reflected light of the illumination light on the substrate and reflects the other to reflect the illumination light on the substrate. What separates light can be used, and the detection means (B1, C6, D9) can be made to detect the reflected light on the substrate of the illumination light separated by the optical member.

  Further, detection light sources (C1, D1) for emitting detection light (DL1, DL2) having a wavelength different from that of the illumination light (EL2) for detecting the position of the substrate and an image of the mask (R2) are obtained. And a projection optical system (26, 27, 28) formed on the substrate (W). In this case, the detection light (DL1, DL2) is used as the optical member (27). (W) is coupled to the optical path of the projection optical system to irradiate (W), and transmits one of the illumination light and the reflected light of the detection light on the substrate, and reflects the other, The detection light (C6, D9) can be made to detect the reflected light on the substrate of the detection light separated by the optical member by using the detection light that separates the reflected light on the substrate. .

  Further, a control unit that outputs a control signal for controlling the position of the substrate (W) based on the detection result of the detection means (B1, C6, D9) can be provided. The detection means (B1) is caused to detect the illumination light (EL2) reflected on the substrate (W), and the light quantity of the illumination light from the illumination light source is controlled based on the detection result of the detection means. A control unit that outputs a control signal for the purpose may be provided.

  According to a second aspect of the present invention, there is provided an exposure apparatus (2) comprising an illumination light source that supplies illumination light (EL2) and the projection optical units (PLU1 to PLU3) according to the first aspect of the present invention described above. Provided.

  According to a third aspect of the present invention, there is provided an exposure method in which a mask (R2) is illuminated with illumination light (EL2), and an image of the mask pattern is exposed and transferred to a substrate (W). There is provided an exposure method in which light is separated from an optical path between the mask and the substrate, the reflected light separated from the optical path is detected, and control is performed based on the detected value.

  In this case, for example, the reflected light of the illumination light (EL2) on the substrate is detected as the reflected light on the substrate (W), and the light amount of the illumination light is controlled based on the detection result. Also good. Further, an optical path between the mask (R2) and the substrate (W) for detecting light (DL1, DL2) having a wavelength different from that of the illumination light (EL2) for detecting the position of the substrate (W). In this case, the reflected light on the substrate is detected as reflected light on the substrate, and the position of the substrate is controlled based on the detection result. It may be.

  According to a fourth aspect of the present invention, there is provided a device manufacturing method (S12) in which a photosensitive substrate (W) is prepared; and the exposure method according to the third aspect of the present invention described above, Exposing a predetermined pattern to each of the first and second regions on the photosensitive substrate (S13); developing the exposed photosensitive substrate, and forming a mask layer having a shape corresponding to the exposed pattern There is provided a device manufacturing method comprising a step (S13) of forming on the surface of the photosensitive substrate; and a step (S13) of processing the surface of the photosensitive substrate through the mask layer.

  In the present invention, the reflected light on the substrate is separated from the optical path between the mask and the substrate, and the separated light is detected. Therefore, the reflected light on the substrate of the illumination light is detected or separately detected light. Can be irradiated to the substrate through a part of the projection optical system, and the reflected light can be detected. The optical path of the illumination light and the reflected light on the substrate (the reflected light of the illumination light on the substrate or the detection light) A part of the optical path of the light reflected from the substrate can be shared. Accordingly, it is possible to provide a compact projection optical unit having a simple configuration, and to simplify, reduce the size and reduce the cost of the exposure apparatus equipped with the projection optical unit, and thus to manufacture the device. Can be reduced.

  According to the present invention, there is an effect that the configuration of the exposure apparatus can be simplified and downsized. In addition, there is an effect that the manufacturing cost of the device can be reduced.

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

[Exposure system]
FIG. 1 is a view schematically showing an outline of the overall configuration of an exposure system according to an embodiment of the present invention. The exposure system includes a first exposure apparatus 1 that exposes a first region on a wafer W as a photosensitive substrate coated with a photoresist (photosensitive material) with exposure light (illumination light) EL1, and the first exposure. As an exposure apparatus (or exposure unit) used together with the apparatus 1, a second exposure apparatus 2 that exposes a second area different from the first area on the wafer W with exposure light (illumination light) EL2, and a first exposure A wafer transfer unit (transfer apparatus) 3 for transferring the wafer W between the apparatus 1 and the second exposure apparatus 2 is provided.

  In the transfer path of the wafer W by the wafer transfer unit 3, there is provided a liquid removal unit 4 that removes liquid from the wafer W on which the exposure process for the first region by the first exposure apparatus 1 has been performed.

  In the following description, the XYZ orthogonal coordinate system shown in FIG. 1 is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. The XYZ orthogonal coordinate system is set so that the Y axis is perpendicular to the paper surface, and the X axis and the Z axis are parallel to the paper surface. In the XYZ orthogonal coordinate system in the figure, the XY plane is actually set to a plane parallel to the horizontal plane, and the Z axis is set to the vertically upward direction.

  In this embodiment, as shown in FIG. 2, a plurality of rectangular shot areas Sh are set in an array on the wafer W.

  Of these shot areas Sh, as indicated by a solid line in FIG. 2, the entire pattern to be transferred (projected image of the pattern formed on the reticle) is transferred as a normal shot area Sh1.

  Further, as shown by the dotted line in FIG. 2, a part of the pattern is located at or near the outer peripheral edge (edge) E of the wafer W. What is transferred in a state where accuracy cannot be obtained is referred to as a chipped shot region Sh2.

  In many cases, a scribe line having a predetermined width is disposed between adjacent shot regions Sh, and an alignment mark or the like is disposed on the scribe line.

  In many cases, the missing shot area does not include the entire pattern, or a part thereof does not have sufficient accuracy. Therefore, although the pattern is transferred, it is generally used as a product (device). This is an area that never happens.

  In this embodiment, it is assumed that the first area on the wafer W that is exposed by the first exposure apparatus 1 is the normal shot area Sh1, and the first area on the wafer W that is exposed by the second exposure apparatus 2 is used. The two areas are assumed to be the missing shot area Sh2.

[First exposure apparatus]
The first exposure apparatus 1 of this embodiment is an immersion type exposure apparatus that exposes the normal shot region Sh1 through a liquid. Further, the first exposure apparatus 1 synchronously moves (scans) a reticle stage (not shown) that moves the reticle R1 relative to the projection optical system PL and a wafer table WT1 of the wafer stage WS1 that moves the wafer W. The step-and-scan type exposure apparatus sequentially transfers the pattern image formed on the reticle R1 to the normal shot region Sh1 on the wafer W.

  However, the first exposure apparatus 1 performs step-and-repeat that collectively transfers the pattern image formed on the reticle R1 to the normal shot region Sh1 of the wafer W while the reticle R1 and the wafer W are stationary. An exposure apparatus of a system may be used.

  In FIG. 1, an illumination optical system (not shown) arranged on the upper side of a reticle R1 has a cross-sectional shape of laser light emitted from a light source such as an ArF excimer laser light source (wavelength 193 nm) orthogonal to the scanning (scanning) direction. It is shaped into a slit extending in the direction, and its illuminance distribution is made uniform and emitted as exposure light EL1.

In this embodiment, the light source is an ArF excimer laser. However, the light source is not limited to this, and an ultrahigh pressure mercury lamp that emits g-line (wavelength 436 nm) or i-line (wavelength 365 nm) or a KrF excimer laser. (Wavelength 248 nm), F ₂ laser (wavelength 157 nm), and other light sources can be used.

  The reticle R1 is attracted and held on a reticle stage (not shown), and the position of the reticle stage is measured by a laser interferometer (not shown).

  The reticle R1 is positioned by moving the reticle stage in a plane (XY plane) perpendicular to the optical axis direction (Z-axis direction) of the projection optical system PL and rotating it slightly around the Z axis (not shown). Is done by. The reticle driving device scans the reticle stage at a constant speed in a predetermined scanning direction when transferring the pattern image of the reticle R1 onto the wafer W.

  Above the reticle stage, a pair of alignment systems (not shown) for photoelectrically detecting a plurality of reticle alignment marks formed around the reticle R1 are provided along the scanning direction.

  Below the projection optical system PL having a plurality of optical elements such as lenses, a wafer stage WS1 is provided. Wafer stage WS1 includes wafer table WT1 and a drive device that moves wafer table WT1 two-dimensionally in the XY plane and moves it slightly in the Z-axis direction.

  The wafer table WT1 is provided with a wafer holder WH1 that detachably vacuum-sucks the wafer W, and the wafer W to be exposed is placed on the wafer holder WH1 and fixed by suction.

  The position of wafer table WT1 in the X and Y axis directions is measured by a laser interferometer (not shown). The position of wafer table WT1 in the Z-axis direction is measured by AF sensor (surface position detection device) AF1 provided in an autofocus mechanism (AF mechanism).

  Although not shown in FIG. 1, a center table (not shown) capable of moving up and down in the vertical direction (Z-axis direction) is provided at the center of the wafer holder WH1. The center table has a suction port for vacuum-sucking the back surface of the wafer W, and is a vertical movement mechanism for carrying the wafer W in and out of the wafer stage WS1 (wafer holder WH1). The center table transports the wafer W to the second exposure apparatus 2. A coater (coating apparatus) for applying a photoresist onto the wafer W and / or a developer for developing a pattern exposed and transferred onto the wafer W between the wafer transfer unit 3 and adjacent to the exposure system When a (developing device) (hereinafter referred to as a coater / developer) or the like is installed, the wafer W is transferred to or from a transfer unit provided in the coater / developer.

  On the side of the projection optical system PL, an off-axis type alignment sensor AS1 for measuring position information of a wafer mark (alignment mark) formed on the wafer W is provided.

  In this embodiment, the alignment sensor AS1 irradiates the target mark with broadband detection light that does not sensitize the resist on the wafer W, and receives an image of the target mark received on the light receiving surface by reflected light from the target mark; An image of an unillustrated index (an index mark on an index plate provided in the sensor) is captured by an image sensor (camera) such as a two-dimensional CCD (Charge Coupled Device), and the captured image is output. A processing type FIA (Field Image Alignment) type sensor is used.

  An AF sensor (surface position detection device) AF1 including a light transmission optical system 11 and a light reception optical system 12 is provided in the vicinity of the projection optical system PL.

  The AF sensor AF1 receives a detection light (a plurality of slit lights) from a light source from a light transmission optical system 11 that irradiates the surface of the wafer W as a test surface from an oblique direction, and a reflected light from the surface of the wafer W. And a light receiving optical system 12 having a detector composed of a line sensor or the like that detects the position of the wafer W in the Z-axis direction based on the output of the detector.

  Based on the detection result, wafer table WT1 described above is driven in the Z-axis direction, and the surface of wafer W is accurately aligned with the image plane of projection optical system PL.

  On the wafer table WT1 of the wafer stage WS1, a reference plate (not shown) used for calibration of various sensors, measurement of a baseline amount, and the like is attached. On the surface of the reference plate, a reference mark (fiscal mark) that can be detected by the alignment system and other marks are formed together with the mark of the reticle R1. Here, the baseline amount is an amount indicating the distance between the reference position (for example, the center of the pattern image) of the pattern image of the reticle R1 projected on the wafer W and the center of the visual field of the alignment sensor AS1.

  Since the first exposure apparatus 1 is a liquid immersion type, although not shown in the vicinity of the front end portion on the image plane side (wafer W side) of the projection optical system PL, the liquid constituting the liquid immersion mechanism is omitted. A supply nozzle and a liquid recovery nozzle are provided so as to face the supply nozzle. The liquid supply nozzle is connected to the liquid supply apparatus via a supply pipe, and the liquid recovery nozzle is connected to a recovery pipe connected to the liquid recovery apparatus.

  As the liquid, for example, ultrapure water that transmits ArF excimer laser light (wavelength 193 nm) is used.

  The refractive index n of water with respect to ArF excimer laser light is approximately 1.44. In this water, the wavelength of the exposure light EL1 is shortened to 193 nm × 1 / n = about 134 nm. A control device (not shown) appropriately controls the liquid supply device and the liquid recovery device to supply the liquid (pure water) from the liquid supply nozzle and recover the liquid from the liquid recovery nozzle, whereby the projection optical system PL A certain amount of liquid Lq is held between the wafer W and the wafer W. The liquid Lq is always changed during exposure.

  When the exposure process for all the normal shot areas Sh1 to be exposed on the wafer W is completed, the supply of the liquid is stopped, and after the liquid on the wafer W is recovered, the wafer table WT1 is moved to a predetermined delivery position, At the delivery position, the wafer W is delivered (unloaded) to the wafer transfer unit 3.

[Wafer transfer unit]
The wafer transfer unit 3 includes an articulated transfer robot having a first arm unit 31, a second arm unit 32, a hand unit 33 and a robot body 34.

  One end of the first arm unit 31 is attached to the robot body 34 via a first joint 35 that is rotationally driven by a motor (not shown), and one end of the second arm unit 32 is connected to the other end of the first arm unit 31. The hand portion 33 is attached to the other end of the second arm portion 32 via a third joint 37 that is rotationally driven by a motor (not shown). ing.

  Here, the first to third joints 35, 36, and 37 are set so that their rotation center axes are substantially parallel to the Z axis, but also rotate around the X and / or Y axes. A multiaxial joint may be used.

  The hand portion 33 is formed in, for example, a substantially U shape in the XY plane, and a plurality of suction holes (not shown) for vacuum-sucking the back surface of the wafer W are provided on the upper surface thereof.

  By appropriately rotating the first to third joints 35, 36, and 37, the wafer W is received from the first exposure apparatus 1 at a predetermined delivery position (first delivery position), and is then given to the second exposure apparatus 2. It can be delivered at the delivery position (second delivery position).

  Further, the wafer transfer unit 3 can position the wafer W at a predetermined liquid removal position for performing liquid removal by the liquid removal unit 4 described later.

  In addition, when the height of the 1st delivery position of the 1st exposure apparatus 1 and the 2nd delivery position of the 2nd exposure apparatus 2 differs, for example, the raising / lowering apparatus which raises / lowers the 1st joint 35 to a Z-axis direction is a robot main body. For example, the wafer W may be moved in the Z-axis direction by providing it on the surface 34.

  Further, the wafer transfer unit 3 is not limited to such a configuration, and may be a slider type, or an articulated robot having another configuration.

  Further, the wafer transfer unit 3 may be a dedicated apparatus for transferring the wafer W between the first exposure apparatus 1 and the second exposure apparatus 2, but a coater / developer or the like is adjacent to the exposure system. If it is installed, it may also be used as a transfer unit for delivering the wafer W between the exposure system and the coater / developer.

[Liquid removal unit]
A liquid removal unit 4 is provided in the transfer path of the wafer W by the wafer transfer unit 3. The liquid removal unit 4 has droplets relating to the liquid Lq supplied between the projection optical system PL and the wafer W on the wafer W exposed by the first exposure apparatus 1 which is an immersion type exposure apparatus. It is a device that removes any remaining residue. By removing the remaining droplets, it is possible to prevent an adverse effect on the exposure processing performed by the second exposure apparatus 2 in the missing shot region Sh2 on the wafer W performed in the next step.

  As the liquid removal unit 4, gas blowing is performed by spraying a gas compressed from the nozzle 41 onto the surface (pattern formation surface) of the wafer W positioned at the liquid removal position in the wafer W transfer path by the wafer transfer unit 3. An apparatus can be illustrated.

  As the shape of the nozzle 41, gas is blown onto the surface of the wafer W as a whole, or gas is applied to a part of the surface of the wafer W so that the cross-sectional shape of the ejected gas is an elongated rectangular shape. What to spray can be used.

  In the latter case, the wafer W is moved or rotated by the wafer transfer unit 3 during the gas blowing, and as a result, the gas is blown over the entire surface of the wafer W.

  Instead of moving or rotating the wafer W, the nozzle 41 may be moved or rotated on the stationary wafer W. You may move both the wafer W and the nozzle 41 relatively.

  The gas ejected from the nozzle 41 can be the same as the gas (air, nitrogen, helium, etc.) in the chamber that accommodates the exposure system.

  In this embodiment, the inside of the chamber is assumed to be air, and the gas for removing liquid ejected from the nozzle 41 is also assumed to be air.

  The temperature of the gas is preferably set to the same temperature as the gas supplied for air conditioning in the chamber so that the temperature of the wafer W is not changed as much as possible by blowing the gas. For example, the gas supplied to air-condition the chamber can be branched and ejected from the nozzle 41. You may use it in the form of circulating the gas in the said chamber.

  In addition, it is preferable that the direction of the ejection of the gas from the nozzle 41 is a direction in which the droplets scattered by the gas blowing toward the first exposure apparatus 1 or the second exposure apparatus 2 are not directed as much as possible. A nozzle, an enclosure, or the like that sucks the sprayed gas may be separately provided to prevent the droplets from being scattered.

[Inspection unit]
In the transfer path of the wafer W by the wafer transfer unit 3, an inspection unit 5 is provided adjacent to the liquid removal unit 4 described above. The inspection unit 5 has droplets relating to the liquid Lq supplied between the projection optical system PL and the wafer W on the wafer W exposed by the first exposure apparatus 1 which is an immersion type exposure apparatus. It is an apparatus for inspecting whether or not it remains.

  The inspection unit 5 determines whether or not liquid droplets remain on the wafer W so as not to adversely affect the exposure process performed by the second exposure apparatus 2 on the chipped shot area Sh2 on the wafer W performed in the next process. Inspect.

  The inspection of the presence or absence of residual liquid droplets by the inspection unit 5 may be performed by inspecting whether liquid droplets remain after the liquid removal by the liquid removal unit 4 described above, or by removing the liquid. Before the liquid removal by the unit 4, the presence or absence of residual liquid droplets on the wafer W is inspected, and when there are residual liquid droplets, the liquid removal unit 4 performs the liquid removal described above. Good.

  In addition, after the liquid removal unit 4 removes the liquid, the presence or absence of residual liquid droplets is inspected. If it is determined that there are residual liquid droplets, the wafer W to which the residual liquid droplets are attached is determined as an error wafer. You may make it store in another predetermined storing place, without passing to the 2nd exposure apparatus 2, and you may make it implement the liquid removal by the liquid removal unit 4 again.

  The inspection unit 5 illuminates the entire surface (pattern formation surface) of the wafer W set at the liquid removal position, images it at once with a two-dimensional CCD camera or the like, and inspects for the presence of residual droplets by image analysis. You can

  In addition, the inspection light source for illuminating a part of the wafer W in a line shape and the line sensor are used for imaging. During imaging, the wafer W is moved or rotated by the wafer transfer unit 3, and as a result, the wafer W You may make it image the whole surface.

  Instead of moving or rotating the wafer W, the light source and the sensor may be moved or rotated on the stationary wafer W. The wafer W and both the light source and the sensor may be moved relatively.

  As schematically shown in FIG. 1, the inspection unit 5 includes a light source 51 that illuminates a part of the wafer W obliquely in a line shape, and diffraction when the residual liquid droplets are present. Alternatively, it is preferable to use a dark field system in which scattered light is received by a sensor 52 composed of a one-dimensional CCD or the like.

[Second exposure apparatus]
Unlike the liquid immersion type first exposure apparatus 1, the second exposure apparatus 2 of this embodiment is a dry system that exposes the missing shot region Sh <b> 2 via a gas that exists between the exposure optical system 21 and the wafer W. Exposure apparatus.

  In the second exposure apparatus 2, the exposure optical system 21 including the projection optical system and the illumination optical system including the reticle R2 is fixed, and the exposure optical system 21 and the wafer W are moved while the wafer W is moved stepwise. Is a step-and-repeat type exposure apparatus that collectively exposes and transfers the pattern image of the reticle R2 to each chipped shot area Sh2 on the wafer W in a state where is stationary.

  However, the second exposure apparatus 2 is a step-and-step in which either one or both of the exposure optical system 21 and the wafer W are relatively moved to sequentially transfer the image of the pattern of the reticle R2 to each missing shot area Sh2. -It may be a scanning method.

  As shown in FIG. 3, the exposure optical system 21 converts exposure light (illumination light) EL2 introduced from a light source (not shown) through the light guide 22 into a lens system 23, a mirror 24, and a reticle. Irradiation onto the wafer W is performed via an illumination optical system including R2 and a projection optical system having a mirror 25, a first projection lens system 26, a mirror 27, and a second projection lens system 28.

  As will be described in detail later, the projection optical system is configured as a projection optical unit that is provided with an exposure amount detection system (FIG. 4), an alignment mark detection system (FIG. 5), or a focus detection system (FIG. 6). ing.

  The wavelength of the exposure light EL2 in the second exposure apparatus 2 is preferably substantially the same as that of the exposure light EL1 in the first exposure apparatus 1. However, since the second exposure apparatus 2 exposes the missing shot region Sh2 that is not used for device manufacture, a different wavelength (long wavelength) from that of the first exposure apparatus 1 may be used.

In the present embodiment, the light source used in the second exposure apparatus 2 is an ArF excimer laser as in the first exposure apparatus 1, but is not limited to this, and g-line (wavelength 436 nm), i-line As in the case of the first exposure apparatus 1, an ultra-high pressure mercury lamp that emits (wavelength 365 nm), a KrF excimer laser (wavelength 248 nm), an F ₂ laser (wavelength 157 nm), or other light sources can be used. is there.

  The reticle R2 has a pattern density that is approximately the same as that of the pattern image of the reticle R1 transferred to the normal shot region Sh1 by the first exposure apparatus 1 (hereinafter sometimes referred to as the first pattern for simplicity). A line and space pattern in which line patterns are arranged at a predetermined interval (pitch) is formed.

  As the reticle R2, a plurality of types of reticles having different line and space pattern duties (line width, arrangement interval, etc.) may be prepared, and may be used by appropriately replacing them with the pattern density of the first pattern. .

  Further, by attaching these plural types of reticles to a rotation revolver or the like and rotating the revolver by a predetermined angle, an appropriate pattern may be selectively arranged on the optical path of the exposure optical system 21. . Here, it is assumed that reticle R2 is fixed to the casing of exposure optical system 21 in a state where the position of fine reticle R2 can be finely adjusted.

  As shown in FIG. 1, a wafer stage WS <b> 2 is provided below the projection optical system (projection lens system 28) of the exposure optical system 21. Wafer stage WS2 includes wafer table WT2 and a drive device that moves wafer table WT2 two-dimensionally in the XY plane and moves it slightly in the Z-axis direction.

  The wafer table WT2 is provided with a wafer holder WH2 as a holding mechanism that detachably sucks the wafer W, and the wafer W as an exposure target is placed on the wafer holder WH2 and fixed by suction.

  Wafer holder WH2 is supported on wafer table WT2 by a rotation mechanism (not shown) that rotates so as to be positioned every 90 degrees within a range of 360 degrees.

  The position of wafer table WT2 in the X and Y axis directions is measured by a laser interferometer or an encoder (not shown). The position of wafer table WT2 in the Z-axis direction is determined by AF sensor AF2 when AF sensor (surface position detection device) AF2 is provided, or when the projection optical unit is provided with a composite focus detection system. Is measured by the focus detection system.

  Although not shown, a center table that can move up and down in the vertical direction (Z-axis direction) is provided at the center of the wafer holder WH2. The center table has a suction port for sucking and holding the wafer W at the tip, and is a vertical movement mechanism for carrying the wafer W in and out of the wafer stage WS2 (wafer holder WH2). The wafer W is transferred to or from a transfer unit provided in a coater / developer (not shown) disposed adjacent to the exposure system.

  In FIG. 3, a pair of alignment sensors AS <b> 2 are provided so as to be directed to two predetermined locations on the wafer W. These alignment sensors AS2 are devices for measuring positional information of wafer marks (alignment marks) formed on the wafer W.

  The alignment sensor AS2 receives detection light supplied from a light source (detection light source) not shown through the light guide A1 via the lens system A2, the reflection mirror A3, the half prism A4, the reflection mirror A5, and the lens system A6. , A light transmission system for irradiating a predetermined field area including the alignment mark on the wafer W, and light reception for introducing the reflected light to the sensor A8 via the lens system A6, the reflection mirror A5, the half prism A4, and the lens system A7. System.

  These alignment sensors AS2 can be moved in the X and Y axis directions, respectively, and their positions can be changed according to the positions of the alignment marks on the wafer W to be measured.

  The detection light is broadband light that does not expose the resist on the wafer W. The sensor A8 is an image pickup device (camera) composed of a two-dimensional CCD or the like, and performs image processing on the image of the alignment mark formed on the light receiving surface thereof to detect the position of the alignment mark.

  Based on the detection results of the pair of alignment sensors AS2, the positional deviation amount (shift amount) of the wafer W in the X and Y axis directions and the rotational deviation amount around the Z axis are detected, and the wafer stage WS2 is driven, The amount of deviation is corrected.

  Here, the alignment sensor AS2 is described as being provided independently of the exposure optical system 21, but the projection optical system of the exposure optical system 21 is described later with reference to FIG. As an example, when the projection optical unit PLU2 having a composite alignment mark detection system is used, the alignment sensor AS2 can be omitted.

  Further, instead of measuring the position information of the wafer mark formed on the wafer W by the alignment sensor AS2, the pre-alignment unit that optically detects the outer shape (edge) of the wafer W is used to perform the X and Y axis directions of the wafer W. The positional deviation amount and the rotational deviation amount about the Z axis may be detected. Such a pre-alignment unit is disclosed in, for example, US Pat. No. 6,225,012 and US Pat. No. 6,624,433.

  The alignment mark detection system of the alignment sensor AS2 or the projection optical unit PLU2 described later normally detects an alignment mark (a pattern formed through a process such as exposure, development, and etching) formed on the wafer W. When the exposure process for the normal shot region Sh1 by the first exposure apparatus 1 is the exposure process for the first layer (exposure process for forming a pattern on the wafer W for the first time), the exposure by the first exposure apparatus 1 The latent image of the alignment mark exposed and transferred in the process is detected.

  In FIG. 3, an AF sensor (surface position detection device) AF2 is provided in the vicinity of the exposure optical system 21. As this AF sensor AF2, a sensor provided with the light transmission optical system 11 and the light receiving optical system 12 similar to the AF sensor AF1 provided in the first exposure apparatus 1 can be used.

  Based on the output of the AF sensor AF2, the wafer table WT2 is driven in the Z-axis direction, and the surface of the wafer W is accurately aligned with the image plane of the projection optical system (projection lens system 28) of the exposure optical system 21. .

  Here, the AF sensor AF2 is described as being provided independently of the exposure optical system 21, but the projection optical system of the exposure optical system 21 is described later with reference to FIG. As described above, when the projection optical unit PLU3 including a focus detection system is used, the AF sensor AF2 can be omitted.

  Further, when the depth of focus of the pattern image transferred onto the wafer W by the second exposure apparatus (exposure unit) 2 is sufficiently deep, the AF sensor AF2 may not be used.

  The exposure processing for the normal shot region Sh1 is completed by the first exposure apparatus 1, residual liquid droplets are removed by the liquid removal unit 4 in the conveyance path by the wafer conveyance unit 3, and the presence of the residual liquid droplets is confirmed by the inspection unit 4. The wafer W that has not been transferred is transferred from the wafer transfer unit 3 onto the wafer holder WH2 of the wafer table WT2 and sucked and held at a predetermined transfer position.

  Next, a predetermined alignment mark on the wafer W is measured by the alignment sensor AS2 or the alignment mark detection system shown in FIG. 5, and the wafer stage WS2 is driven on the basis of the measurement result to the exposure optical system 21 of the wafer W. The positional deviation in the X and Y axis directions and the rotational deviation around the Z axis are corrected.

  Thereafter, the missing shot area Sh2 to be exposed first on the wafer W is positioned in the projection area of the exposure optical system 21, and based on the measurement result by the AF sensor AF2 or the focus detection system shown in FIG. The position in the axial direction is adjusted, and the pattern image of the reticle R2 is transferred to the chipped shot area Sh2.

  Next, the wafer is stepped to the adjacent missing shot area Sh2, and the exposure process is similarly performed for the missing shot area Sh2 that can be exposed in relation to the strokes of the wafer stage WS2 in the X and Y axis directions. Repeat with the repeat method.

  Thereafter, the rotation mechanism of the wafer holder WH2 is driven to rotate the wafer W by 90 degrees and similarly perform the exposure process. Thereafter, the exposure process is similarly performed while rotating by 90 degrees.

  When the exposure process for all of the missing shot areas Sh2 to be exposed is completed, the exposure process is carried out to another transport unit such as a coater / developer disposed adjacent to the exposure system at a predetermined delivery position. The same processing is repeatedly performed on the wafers W sequentially loaded by the wafer transfer unit 3.

[Projection optical unit with multiple exposure detection systems]
As shown in FIG. 4, the exposure optical system 21 of this embodiment includes a projection optical unit PLU1 in which an exposure amount detection system is combined with a projection optical system. The exposure amount detection system includes a detection sensor B1 for detecting the amount of light and a mirror 25 that is also a part of the projection optical system.

  Here, the mirror 25 is an optical member that separates the reflected light of the exposure light EL2 on the wafer W by transmitting one of the exposure light EL2 and the reflected light of the exposure light EL2 on the wafer W and reflecting the other. It is a half mirror. The detection sensor B1 is a detection unit having a photoelectric conversion element that detects light separated by the half mirror 25 (exposure light EL reflected light from the wafer W).

  The exposure light EL2 introduced from the light source (not shown) through the light guide 22 and supplied through the lens system 23, the mirror 24, and the reticle R2 is reflected by the half mirror 25, and the first projection lens system 26, mirror. The light is irradiated onto the wafer W through the second projection lens system 28 and the second projection lens system 28.

  The reflected light from the wafer W is supplied to the half mirror 25 through the second projection lens system 28, the mirror 27, and the first projection lens system 26, passes through the half mirror 25, and enters the light receiving surface of the detection sensor B1. Is done.

  The light receiving surface of the detection sensor B1 is set at a position almost conjugate with the pattern formation surface of the reticle R2, and the detection signal (photoelectric conversion signal) of the detection sensor B1 is supplied to a control device (not shown). It is preferable that the light receiving surface of the detection sensor B1 is sufficiently inclined with respect to the optical axis direction in order to prevent flare due to multiple reflections and improve detection accuracy.

  The control device is a control unit including a microcomputer and a memory. Based on a photoelectric conversion signal as a detection result supplied from the detection sensor B1, the control device obtains an irradiation amount (exposure amount per unit time) actually irradiated onto the wafer W and is emitted from the illumination optical system. A control signal for controlling the amount of exposure light EL2 is output.

  This light quantity control signal is outputted to the light source when the light source used can adjust the light quantity, or is arranged in the illumination optical system (for example, in the lens system 23). Output to variable dimmer. A variable dimmer is a device that adjusts the dimming rate of light passing therethrough stepwise or continuously. Based on this output signal, light quantity control is performed in the light source or the variable dimmer.

  This light amount control can be performed during the exposure process. The reflectance of the wafer W is obtained from the detection result by the detection sensor B1, and data including this reflectance is sent to the control device provided in the first exposure apparatus 1 via a communication line, and exposure control in the first exposure apparatus 1 is performed. You may make it use for.

  Further, the focal position of the projection optical system can be detected by finely driving the wafer table WT2 in the Z-axis direction while monitoring the photoelectric conversion signal from the detection sensor B1, and based on this, for example, an AF sensor Calibration of autofocus control in the AF2 or a focus detection system described later with reference to FIG. 6 can also be performed.

  In FIG. 4, the mirror 25 is a half mirror and the reflected light from the wafer W is separated and detected by the detection sensor B1, but the reflected light from the wafer W is separated by using the mirror 27 as a half mirror. Thus, the detection may be performed by the detection sensor B1 arranged corresponding to this.

  By providing such a projection optical unit PLU1, the light amount control of the exposure light EL2 can be performed in consideration of the reflectance of the exposure light EL2 on the surface of the wafer W based on the reflected light of the exposure light EL2 on the wafer W. It is possible to improve the exposure accuracy. In addition, since the exposure amount detection system is provided in the form attached to the projection optical system, the configuration is simple.

[Projection optical unit with multiple alignment mark detection systems]
As the exposure optical system 21, as shown in FIG. 5, an exposure optical system having a projection optical unit PLU 2 in which an alignment mark detection system is arranged in a composite manner can be used. In addition, when using what is equipped with this projection optical unit PLU2, the alignment sensor AS2 mentioned above can be abbreviate | omitted.

  This alignment mark detection system includes a detection light source C1 that emits detection light DL1, a detection sensor C6 that detects the reflected light of the detection light DL1 on the surface of the wafer W, and a mirror 27 that is also part of the projection optical system. It is configured with. The alignment mark detection system also includes a half prism C3, lens systems C2, C4, C5, and the like in order to optically connect these optical members.

  The detection light source C1 emits detection light DL1 having a wavelength different from that of the exposure light EL2 for detecting the position of the wafer W. The halogen lamp emits broadband detection light that does not expose the resist on the wafer W. A laser diode or the like can be used. The wavelength of the detection light DL1 emitted from the detection light source C1 is not particularly limited as long as it does not cause the resist on the wafer W to be exposed to light. However, it is considered that the dichroic mirror 27 described later can be easily manufactured. Therefore, the wavelength is preferably about 1.5 times that of the exposure light EL2.

  The detection sensor C6 is detection means having a photoelectric conversion element that detects reflected light of the detection light DL1 on the surface of the wafer W. As the photoelectric conversion element, an imaging element (camera) including a two-dimensional CCD (Charge Coupled Device) or the like can be used. The light receiving surface of the detection sensor C6 is set at a position almost conjugate with the pattern formation surface of the reticle R2, and the detection signal (photoelectric conversion signal) of the detection sensor C1 is supplied to a control device (not shown).

  Here, the mirror 27 is a dichroic mirror provided in the pupil space of the projection optical system (between the first projection lens system 26 and the second projection lens system 28). The dichroic mirror 27 couples the detection light DL1 to the optical path of the projection optical system to irradiate the wafer W with the detection light DL1 from the detection light source C1, and also reflects the reflected light of the exposure light EL2 and the detection light DL1 on the wafer W. It is an optical member that separates the reflected light of the detection light DL1 from the wafer W by transmitting one and reflecting the other.

  Here, the exposure light EL2 for exposing the wafer W from the illumination optical system is reflected, and the reflected light on the surface of the wafer W of the detection light DL1 from the alignment mark detection system is transmitted.

  The detection light DL1 emitted from the detection light source C1 is reflected by the half prism C3 via the lens system C2, passes through the dichroic mirror 27 via the lens system C4, and passes through the second projection lens system 28 and passes through the wafer W. The region including the upper alignment mark is irradiated.

  The reflected light from the wafer W passes through the dichroic mirror 27 through the second projection lens system 28, passes through the half prism C3 through the lens system C4, and is received by the detection sensor C6 through the lens system C5. The image is formed on the surface.

  The photoelectric conversion signal from the detection sensor C6 is supplied to the control device, and the control device detects the position of the alignment mark formed on the wafer W by performing image processing. Based on the detected position of the alignment mark, the control device outputs a control signal for controlling the position and rotation of the wafer W in the XY plane to the driving device of the wafer stage WS2, thereby The position and rotation of the wafer W in the XY plane are adjusted so that the shot area to be exposed (here, the missing shot area Sh2) coincides with the projection area by the projection optical system.

  As described above, since the projection optical unit PLU2 is configured as a single unit including the projection optical system and the alignment mark detection system in combination, an alignment mark detection system such as the alignment sensor AS2 can be obtained by using this. There is no need to provide it separately from the projection optical system, the configuration of the apparatus can be simplified and downsized, the number of steps required for assembling the exposure apparatus can be reduced, and the cost can be reduced. .

[Projection optical unit with multiple focus detection systems]
As the exposure optical system 21, as shown in FIG. 6, an exposure optical system having a projection optical unit PLU 3 formed by combining a focus detection system with a projection optical system can be used. In addition, when using what is equipped with this projection optical unit PLU3, AF sensor AF2 mentioned above can be abbreviate | omitted.

  The focus detection system includes a detection light source D1 that emits detection light DL2, a detection sensor D9 that detects reflected light of the detection light DL2 on the surface of the wafer W, and a mirror 27 that is also a part of the projection optical system. It is prepared for. The focus detection system includes a half prism D5 and lens systems D2, D4, D6, and D7 to optically connect these optical members, and a first pinhole disposed in the optical path. A plate D3 and a second pinhole plate D8 are also provided.

  The detection light source D1 emits detection light DL2 having a wavelength different from that of the exposure light EL2 for detecting the position of the wafer W. Here, the laser emits detection light that does not sensitize the resist on the wafer W. A diode is used. The wavelength of the detection light DL2 emitted from the detection light source D1 is not particularly limited as long as it does not expose the resist on the wafer W, but it is considered that the dichroic mirror 27 described later can be easily manufactured. Therefore, the wavelength is preferably about 1.5 times that of the exposure light EL2.

  The detection sensor D9 is detection means having a photoelectric conversion element that detects reflected light of the detection light DL2 on the surface of the wafer W. A photodiode or the like can be used as the photoelectric conversion element. The light receiving surface of the detection sensor D9 is set at a position almost conjugate with the pattern formation surface of the reticle R2, and the detection signal (photoelectric conversion signal) of the detection sensor D9 is supplied to a control device (not shown).

  Here, the mirror 27 is a dichroic mirror provided in the pupil space of the projection optical system (between the first projection lens system 26 and the second projection lens system 28). The dichroic mirror 27 couples the detection light DL2 to the optical path of the projection optical system to irradiate the wafer W with the detection light DL2 from the detection light source D1, and also reflects the reflected light of the exposure light EL2 and the detection light DL2 on the wafer W. It is an optical member that separates the reflected light of the detection light DL2 from the wafer W by transmitting one and reflecting the other. Here, the exposure light EL2 for exposing the wafer W from the illumination optical system is reflected, and the reflected light on the surface of the wafer W of the detection light DL2 from the alignment mark detection system is transmitted.

  The detection light DL2 emitted from the detection light source D1 is shaped by the pin pole of the first pinhole plate D3 disposed at a position conjugate with the pattern surface of the reticle R2 via the lens system D2, and then via the lens system D4. The light is reflected by the half prism D5, passes through the dichroic mirror 27 through the lens system D6, and is irradiated onto the wafer W through the second projection lens system 28.

  The reflected light of the detection light DL2 on the wafer W passes through the dichroic mirror 27 through the second projection lens system 28, passes through the half prism D5 through the lens system D6, and passes through the lens system D7 and the first pinhole. The light imaged on the second pinhole plate D8 disposed at a position conjugate with the plate D3 (pattern surface of the reticle R2) and passed through the pinhole formed in the second pinhole plate D8 is the back side thereof. The light is incident on the light receiving surface of a detection sensor D9 disposed in the vicinity.

  The photoelectric conversion signal from the detection sensor D9 is supplied to the control device. According to the confocal principle, when the surface of the wafer W coincides with the image plane of the projection optical system, the intensity of the output signal from the detection sensor D9 is maximized. The signal intensity decreases according to the focus amount. Therefore, by monitoring the output signal from the detection sensor D9 and finely driving the wafer table WT2 in the Z-axis direction, the surface of the wafer W can be matched with the image plane of the projection optical system.

  As described above, since the projection optical unit PLU3 is configured as a single unit having a projection optical system and a focus detection system in combination, the focus detection system such as the AF sensor AF2 is independent of the projection optical system. Therefore, the apparatus configuration can be simplified and reduced in size, and the man-hours required for assembling the exposure apparatus can be reduced. As a result, the cost can be reduced.

  When the above-described AF sensor AF2 is provided separately, the detection result of the focus detection system provided in the projection optical unit PLU3 can be used for calibration of the AF sensor AF2.

  In the exposure optical system 21 of the second exposure apparatus 2 described above, as shown in FIG. 7, four movable plates are provided with rectangular openings in the plane perpendicular to the optical axis in the vicinity of the reticle R2. It is possible to provide a blind mechanism RB arranged so as to have.

  Each of the four movable plates is configured to be able to advance and retreat with respect to the optical axis, and can arbitrarily change a rectangular opening region centered on the optical axis. The blind mechanism RB is disposed at a position slightly defocused from the pattern surface (or its conjugate surface) of the reticle R2. By this blind mechanism RB, the size of the exposure area on the wafer W can be arbitrarily changed within a certain range.

  Note that any two or all of the exposure amount detection system, the alignment mark detection system, and the focus detection system provided in the three types of projection optical units PLU1 to PLU3 described above may be combined to form a single unit. A projection optical unit may be configured.

  In the above-described embodiment, the exposure optical system 21 of the second exposure apparatus 2 includes three mirrors (24, 25, 27) for bending the optical path to reduce the size. The number may be 2 or less, or 4 or more. In this case, the detection systems included in the projection optical units PLU1 to PLU3 described above can be combined by using any one of these mirrors as an optical member such as a half mirror or a dichroic mirror. In addition to these optical path bending mirrors, an optical member such as a half mirror or a dichroic mirror may be inserted in the optical path to couple the detection systems.

  In addition, the exposure optical system 21 may be configured as a straight body type in which optical members and the like are arranged in series in the Z-axis direction without providing any optical path bending mirror. In this case, an optical member such as a half mirror or a dichroic mirror is inserted into the optical path of the projection optical system to couple the detection systems.

  Next, a device manufacturing method using the exposure system according to the embodiment of the present invention will be described. FIG. 8 is a flowchart of production of a device (a semiconductor chip such as an IC or LSI, a CCD, a thin film magnetic head, a micromachine, etc.) using the exposure system according to the embodiment of the present invention.

  As shown in FIG. 8, first, in step S10 (design step), device function and performance design (for example, circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. Subsequently, in step S11 (reticle manufacturing step), a reticle on which the designed circuit pattern is formed is manufactured.

  On the other hand, in step S12 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

  Next, step S13 (wafer processing step) is performed using the reticle and wafer prepared in steps S10 to S12. In this step 13, a resist coating process in which a photosensitive material (photoresist) is coated on the wafer to form a photosensitive substrate, and an exposure process using the exposure systems (first exposure apparatus 1 and second exposure apparatus 2) described above. (Exposure process to normal shot area and chipped shot area), development process (process to develop the exposed photosensitive substrate and form a mask layer having a shape corresponding to the exposed pattern on the surface of the photosensitive substrate), Further, a circuit is formed on the wafer by performing a plurality of processes such as an etching process (a process for processing the surface of the photosensitive substrate through the mask layer) and, if necessary, a CMP process.

  Next, in step S14 (device assembly step), the wafer processed in step S13 is used to form chips. This step S14 includes processes such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), and the like.

  Finally, in step S15 (inspection step), inspections such as an operation confirmation test and a durability test of the manufactured device are performed. After these steps, the device is completed and shipped.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the above-described embodiment, the projection optical system 21 of the second exposure apparatus 2 that performs the exposure process on the missing shot area is provided with each detection system (exposure amount detection system, alignment mark detection system, focus detection system) in combination. Although the case where the optical units PLU1 to PLU3 are provided has been described, the projection optical system PL of the first exposure apparatus 1 that performs exposure processing on the normal shot area is combined with each of the detection systems described above to form a projection optical unit, It is also possible to simplify the configuration and reduce the size.

It is a figure which shows typically the whole structure of the exposure system of embodiment of this invention. It is a figure for demonstrating the normal shot area | region and missing shot area | region set on the wafer of embodiment of this invention. It is a perspective view which shows the structure of the principal part of the optical system and wafer stage of the 2nd exposure apparatus of embodiment of this invention. It is a figure which shows the optical system containing the projection optical unit provided with the exposure amount detection system of embodiment of this invention in combination. It is a figure which shows the optical system containing the projection optical unit provided with the alignment mark detection system of embodiment of this invention in combination. It is a figure which shows the optical system containing the projection optical unit provided with the focus detection system of embodiment of this invention in combination. It is a figure which shows an optical system provided with the blind mechanism of embodiment of this invention. It is a flowchart which shows the device manufacturing process of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... 1st exposure apparatus, 2 ... 2nd exposure apparatus, W ... Wafer, R1, R2 ... Reticle, WS1, WS2 ... Wafer stage, EL1, EL2 ... Exposure light (illumination light), PLU1-PLU3 ... Projection optical unit, B1, C6, D9 ... detection sensor, C1, D1 ... detection light source, DL1, DL2 ... detection light 25 ... mirror (or half mirror), 27 ... mirror (or dichroic mirror), C3, D5 ... half prism.

Claims (10)

A projection optical unit that projects an image of a mask pattern illuminated with illumination light from an illumination light source onto a substrate,
An optical member that is provided in an optical path between the mask and the substrate and separates reflected light from the substrate from the optical path;
Detecting means for detecting light separated by the optical member;
A projection optical unit comprising: The optical member transmits one of the illumination light and the reflected light of the illumination light on the substrate, and reflects the other to separate the reflected light of the illumination light on the substrate,
The projection optical unit according to claim 1, wherein the detection unit detects reflected light on the substrate of the illumination light separated by the optical member. A detection light source that emits detection light having a wavelength different from that of the illumination light for detecting the position of the substrate;
A projection optical system for forming an image of the mask on the substrate;
The optical member couples the detection light to an optical path of the projection optical system to irradiate the detection light on the substrate, and transmits one of the illumination light and the reflected light of the detection light on the substrate. Separating the reflected light from the detection light on the substrate by reflecting the other,
The projection optical unit according to claim 1, wherein the detection unit detects reflected light on the substrate of the detection light separated by the optical member.   The projection optical unit according to claim 3, further comprising a control unit that outputs a control signal for controlling the position of the substrate based on a detection result of the detection unit. The detecting means detects the illumination light reflected on the substrate;
The control part which outputs the control signal for controlling the light quantity of the said illumination light from the said illumination light source based on the detection result of the said detection means is further provided. The projection optical unit described.   An exposure apparatus comprising: an illumination light source that supplies illumination light; and the projection optical unit according to claim 1. An exposure method for illuminating a mask with illumination light and exposing and transferring an image of the mask pattern onto a substrate,
Separating the reflected light from the substrate from the optical path between the mask and the substrate;
Detecting the reflected light separated from the optical path;
An exposure method comprising controlling based on the detected value. The reflected light on the substrate is reflected light on the substrate of the illumination light,
The exposure method according to claim 7, wherein the control is light amount control of the illumination light. Coupling detection light of a wavelength different from the illumination light for detecting the position of the substrate into an optical path between the mask and the substrate;
The reflected light on the substrate is the reflected light on the substrate of the detection light,
8. The exposure method according to claim 7, wherein the control is control of the position of the substrate. A device manufacturing method comprising:
Preparing a photosensitive substrate;
Using the exposure method according to any one of claims 7 to 9, exposing a predetermined pattern to each of the first and second regions on the photosensitive substrate;
Developing the exposed photosensitive substrate and forming a mask layer having a shape corresponding to the exposed pattern on the surface of the photosensitive substrate;
Processing the surface of the photosensitive substrate through the mask layer;
A device manufacturing method comprising:

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