JP2015149427A - Lithography apparatus and goods manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithography apparatus favorable to detect an original point of an encoder.SOLUTION: A lithography apparatus comprises: an encoder for measuring a position of a stage, which includes scales 24, 25 including original point patterns 26, 27 and a plurality of detection parts 22, 23 for detecting signals from the scales 24, 25; and a control part for controlling an operation of the stage and an operation of the encoder in a manner such that original point detection of the encoder is performed by detecting signals of the original point patterns 26, 27 corresponding to some of the plurality of detection parts of the plurality of detection parts 22, 23, respectively, relating to a first range 100 and a second range 200 which are included in a movable range of the stage, and a combination of the plurality of detection parts 22, 23 used for original point detection related to the first range 100 and a combination of the plurality of detection parts 22, 23 used for original point detection related to the second range 200 are the same with each other.

Description

  The present invention relates to a lithographic apparatus and a method for manufacturing an article.

  An exposure apparatus exposes a substrate (such as a wafer or a glass plate having a resist layer formed on the surface) through a pattern of an original (such as a reticle) in a lithography process included in a manufacturing process of a semiconductor device or a liquid crystal display device. Device. As an example of such an exposure apparatus, Patent Document 1 discloses a so-called twin stage type projection exposure apparatus that includes two stages for holding a substrate in order to improve throughput. The twin stage type projection exposure apparatus has two processing areas, a first area (exposure station) for exposing the substrate and a second area (measurement station) for measuring the substrate. Exposure and measurement can be performed in parallel by arranging them in the two regions. Then, the two stages move so as to be switched between the two areas when the respective processes are completed.

  The twin stage exposure apparatus includes measuring instruments such as a laser interferometer and an encoder in order to measure the stage position with high resolution and high accuracy. Patent Document 2 discloses a lithography apparatus using an encoder in order to shorten the optical path of measurement light and reduce the influence of fluctuations in the optical path atmosphere. This encoder has a total of four sensors (encoder heads) installed one by one at the four corners of the stage and four scales fixed in the apparatus, and at least three sensors detect signals from the scales. Thus, the stage position is measured.

  Patent Document 3 discloses a device that detects the origin position by irradiating light from a light source to a reflecting mirror provided on a stage and detecting the return light with a photoelectric sensor in a lithography apparatus.

Japanese Patent Laid-Open No. 10-163099 JP 2007-318119 A JP 2001-217190 A

  In an encoder as described in Patent Document 2, it is difficult to provide a scale so that the position of the stage can be measured over the entire range in which the stage moves due to restrictions on arrangement and cost. Therefore, it is preferable to use a measuring instrument having a lower resolution and a lower accuracy than the encoder in an area where the accuracy required for positioning the stage is low. For example, a capacitance sensor or the like can be used in an area for carrying a substrate in or out of the stage as long as the position of the stage can be measured with lower resolution and lower accuracy. Similarly, when the stage is moving between the exposure station and the measurement station, positioning may be performed using a sensor with lower resolution and accuracy.

  Here, when the stage moves from a region that is positioned using a lower resolution and lower accuracy sensor to a region that is positioned using a higher resolution and higher accuracy incremental encoder, the origin (origin position) of the encoder is detected. There is a need to. The origin detection can be performed by detecting an origin detection pattern provided on the scale with each of the plurality of encoder heads. Here, in order to complete the origin detection earlier, the combination of encoder heads used for origin detection may differ depending on the area where the origin is detected and the path of the stage leading to the area. In that case, a change in the position of each encoder head may cause a deviation (offset) in the positioning of the stage between the two regions (for example, between the measurement station and the exposure station). This deviation can degrade performance such as overlay performance or resolution performance of the lithographic apparatus.

  An object of the present invention is to provide a lithographic apparatus that is advantageous, for example, in terms of detecting the origin of an encoder.

  In order to solve the above problems, the present invention provides a lithography apparatus for forming a pattern on a substrate, the stage holding the substrate, a movable stage, a scale including an origin pattern, and a plurality of signals for detecting signals from the scale. And an encoder for measuring the position of the stage with one of the scale and the plurality of detection units provided on the stage, and a first range and a second range included in the movable range of the stage. For each of the plurality of detection units, each of a plurality of detection units detects a signal from the corresponding origin pattern, thereby detecting the origin of the encoder and detecting the origin with respect to the first range. The operation and error of the stage are set so that the combination of the plurality of detection units used matches the combination of the plurality of detection units used for origin detection with respect to the second range. And having a control unit for controlling the operation of the coder.

  According to the present invention, for example, it is possible to provide a lithographic apparatus that is advantageous in terms of detecting the origin of an encoder.

It is a figure which shows the structure of the exposure apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the position of the reflection part and wafer stage in 1st Embodiment. It is a figure which shows the relationship between piping of a wafer stage, and a movement path | route. It is a flowchart which shows the flow of a detection of an origin position. It is a figure which shows the combination of the use sensor at the time of origin position detection. It is a figure which shows the position of the reflection part in 2nd Embodiment, and a wafer stage. It is a figure which shows the use sensor at the time of the origin position detection in the conventional exposure apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
First, the configuration of the lithography apparatus according to the first embodiment of the present invention will be described. The lithography apparatus is an apparatus that forms a pattern on a substrate such as a wafer. Hereinafter, the lithography apparatus according to the present embodiment will be described as an exposure apparatus as an example. FIG. 1 is a schematic diagram showing a configuration of an exposure apparatus 1 according to the present embodiment. In FIG. 1, the Z-axis is taken in parallel to the optical axis (vertical direction in the present embodiment) of the projection optical system 4 to be described later, and the Y-axis is taken in the scanning direction of the wafer W during exposure within a plane perpendicular to the Z-axis. The X axis is taken in the non-scanning direction orthogonal to the Y axis. As an example, the exposure apparatus 1 is used in a semiconductor device manufacturing process, and a wafer having a resist (photosensitive agent) layer formed on a surface of a pattern formed on a reticle R by a step-and-repeat method. A projection type that exposes on W (on the substrate) is used. Further, the exposure apparatus 1 has a plurality of stages for holding the wafer W in the apparatus, and in this embodiment, in particular, is a so-called twin stage type including two wafer stages 6a and 6b as an example. First, the exposure apparatus 1 includes an exposure station 100 as a first area for mainly exposing the wafer W, a measurement station 200 as a second area for mainly measuring the wafer W, a control unit 300, a wafer, and the like. A transport system 400.

  The exposure station 100 includes an illumination system 2, a reticle stage 3, and a projection optical system 4. The illumination system 2 shapes the light emitted from the light source into a predetermined beam shape, and irradiates the reticle R held on the reticle stage 3. As the light source, ArF excimer laser light (wavelength 193 nm) or the like is used. The reticle R is, for example, a glass original plate on which a fine circuit pattern is formed. The reticle stage 3 can be finely driven in six axes by holding, for example, the reticle R by suction via a reticle chuck (not shown). The projection optical system 4 reduces the circuit pattern image of the reticle R at a predetermined reduction magnification, and forms and projects the image on a shot (pattern formation region) set on the wafer W.

  The measurement station 200 includes a substrate measurement sensor 20 that performs alignment measurement and focus / leveling measurement. Specifically, the substrate measurement sensor 20 includes an alignment mark on a wafer W held on a wafer stage 6 to be described later, and a reference mark on a reference mark plate installed on the wafer stage 6 (both not shown). ) Position measurement. The substrate measurement sensor 20 can also measure the surface shape on the wafer stage 6. The projection optical system 4 and the substrate measurement sensor 20 are both held by the lens barrel surface plate 5 supported from the floor surface via, for example, a vibration isolation unit.

  The wafer stage 6 sucks and holds the wafer W via a chuck (not shown), and can be finely driven in six axes by a stage drive system including, for example, a plane pulse motor, a linear motor, and a voice coil motor. is there. The exposure apparatus 1 also includes a stage surface plate 21 on the floor surface, and the wafer stage 6 is supported on the stage surface plate 21 by way of air bearings, for example. Thereby, the wafer stage 6 is movable (movable) at a designated scanning speed within a predetermined movable range in the XY axis direction. In particular, in the present embodiment, a twin stage type exposure apparatus 1 is illustrated, and in this case, there are two wafer stages 6 (a first wafer stage 6a and a second wafer stage 6b). Each wafer stage 6 is independent between a first movable range (first range) including the exposure position in the exposure station 100 and a second movable range (second range) including the alignment measurement position in the measurement station 200. And can be moved (positions are switched alternately). According to the wafer stage 6, for example, exposure of the first wafer W1 on the first wafer stage 6a at the exposure station 100 and measurement of the second wafer W2 on the second wafer stage 6b at the measurement station 200 are performed in parallel. Can be done.

  The position of the wafer stage 6 is measured using an encoder (linear encoder) and a laser interferometer. Specifically, first, the first wafer stage 6a has a plurality of position sensors (detectors) 22 (22a to 22d) on its upper surface, and similarly, the second wafer stage 6b has a plurality of position sensors on its upper surface. (Detector) 23 (23a to 23d) are provided. Each position sensor 22, 23 includes an encoder head and a laser interferometer, respectively. On the other hand, the exposure apparatus 1 is irradiated from the position sensors 22 and 23 at a fixed position where the position sensors 22 and 23 face each other when any of the wafer stages 6 is located at the stations 100 and 200. Reflecting portions 24 and 25 that reflect light are provided. Each of the reflectors 24 and 25 is an encoder scale (scale reflector) configured in combination with an encoder head described later, and has an incremental pattern which is a periodic diffraction grating pattern on the surface thereof. In the present embodiment, the fixed position is the lower surface of the lens barrel surface plate 5. Further, the shapes and arrangements of the reflecting portion 24 in the exposure station 100 and the reflecting portion 25 in the measurement station 200 will be described later.

  The encoder head detects the displacement of the head position in the XY plane direction with respect to the reflecting portions 24 and 25 based on the change in the intensity of the incremental signal generated according to the position of the incremental pattern by the diffracted light reflected by the incremental pattern. To detect. Based on the displacement of the head position acquired from the encoder head, the controller 300 can determine the rotation amounts θ of the wafer stages 6a and 6b with respect to the X, Y, and Z axes with high accuracy. Further, the laser interferometer is, for example, a Michelson interferometer, and detects a displacement of a distance in the Z-axis direction from each of the reflection units 24 and 25. Based on the distance displacement in the Z-axis direction acquired from the laser interferometer, the control unit 300 accurately sets the rotation amount ωx with respect to the Z-axis and X-axis of each wafer stage 6a, 6b and the rotation amount ωy with respect to the Y-axis. Can be sought. Position information regarding the respective axes and rotation amounts of the wafer stages 6a and 6b obtained in this manner is sent to a stage control unit (not shown) (included inside the control unit 300 or installed outside). It is done. The stage control unit controls the movement of the wafer stages 6a and 6b via the stage drive system based on the drive command from the control unit 300 while referring to the acquired position information. Here, the position of the wafer stage 6 is measured using an encoder and a laser interferometer. On the other hand, when the encoder (encoder head) can detect the position relating to each of the X, Y, and Z axes, the wafer is not used by the laser interferometer but only by the encoder. The position of the stage 6 may be measured.

  The control unit 300 is configured by, for example, a computer and is connected to each component of the exposure apparatus 1 via a line, and can execute operation control or various calculations of each component according to a program or the like. Although not shown, the control unit 300 includes a storage device that stores, as a database, information related to a combination of position sensors 22 and 23, which will be described later, used for detecting the origin position of the wafer stage 6. Note that the control unit 300 may be configured integrally with other parts of the exposure apparatus 1 (in a common casing), or separate from the other parts of the exposure apparatus 1 (in a separate casing). It may be configured.

  The wafer transfer system 400 collects the wafer W from the wafer stage 6 and a loading hand 400 a for loading the wafer W on the wafer stage 6 in the measurement station 200 from a FOUP (not shown) that accommodates the wafer W to be processed. The unloading hand 400b.

  FIG. 2 shows the arrangement of the reflecting portions 24 and 25 at the stations 100 and 200 and the positions of the wafer stages 6a and 6b as viewed from the upper surface side (Z-axis direction plus side) in the exposure apparatus 1. It is a schematic plan view. In FIG. 2, each wafer stage 6a, 6b is shown in a transparent state in consideration of easy understanding. FIG. 2A shows, as an example, a state in which exposure is performed on the first wafer W1 on the first wafer stage 6a at the exposure station 100, and on the second wafer stage 6b at the measurement station 200. It is a figure showing the state which is measuring the 2nd wafer W2. The four position sensors 22a to 22d installed on the first wafer stage 6a are arranged one by one at the four corners on the surface. Similarly, the four position sensors 23a to 23d installed on the second wafer stage 6b are also arranged one by one at the four corners on the surface. The reflection unit 24 in the exposure station 100 includes four reflection units 24a to 24d each having a square plane (surface) shape, and is arranged in parallel on each axis around the projection optical system 4 on the XY plane. Similarly, the reflection unit 25 in the measurement station 200 includes four reflection units 25a to 25d each having a square plane (surface) shape, and is arranged in parallel on each axis around the substrate measurement sensor 20 on the XY plane. . The oblique lines shown in the reflecting portions 24 and 25 in FIG. 2 represent the above-described incremental pattern.

  FIG. 3 is a schematic plan view showing the relationship between the piping 30 connected to each of the wafer stages 6a and 6b and the movement path of each of the wafer stages 6a and 6b. For example, the piping 30a for the first wafer stage 6a extends to the left side of the drawing (X-axis direction minus side) and is connected to an external pneumatic device (not shown). On the other hand, the piping 30b for the second wafer stage 6b extends to the right side (X-axis direction plus side) of the drawing and is connected to an external pneumatic device. As described above, the wafer stages 6a and 6b can move (replace) between the stations 100 and 200, respectively. In the case of this example, the first wafer stage 6a is turned around the left side of the drawing as shown by the white arrow in FIG. , It is replaced by turning around the right side of the page.

  Here, referring back to FIG. 2, when detecting the position of the wafer stage 6 (each wafer stage 6a, 6b), some of a plurality of (four in the present embodiment) position sensors respectively installed. At least three of these are used. Hereinafter, the movable range of the wafer stage 6 in which the position of the wafer stage 6 can be guaranteed with high accuracy by the position sensors 22 and 23 is referred to as “observable range”. Here, since the movable range of the wafer stage 6 is wider than the observable range, depending on the drive position, the observable range may deviate. When the wafer stage 6 is out of the observable range, the encoder head and the laser interferometer as the position sensors 22 and 23 lose their origins with respect to the reflecting portions 24 and 25, and measurement becomes impossible. Therefore, when the wafer stage 6 once goes out of the observable range and then returns to the observable range, the control unit 300 detects the origin position (origin detection) as follows.

  First, in order to clarify the feature of detection of the origin position in the present embodiment, a conventional origin position detection will be described as a comparative example. FIG. 7 is a schematic plan view showing a representative wafer stage position when detecting the origin position and an encoder head used for detecting the origin position at that time. 7A and 7B show the state in the exposure station 100, and FIGS. 7C to 7E show the state in the measurement station 200. FIG. For simplification of the following description, the same reference numerals are given to components corresponding to the components of the exposure apparatus 1 according to the present embodiment shown in FIG.

  First, it is assumed that the wafer stage 6 moves from the measurement station 200 to the exposure station 100. At this time, when the wafer stage 6 that has moved from the measurement station 200 enters an area that can be measured by the encoder head (position sensors 22 and 23) in the exposure station 100, the encoder head detects the origin position. Here, when the first wafer stage 6a has moved around the left side of the drawing, the encoder head is located at the lower left position on the drawing, which is the earliest position facing the reflector 24, as shown in FIG. Detect the origin position. The encoder heads used at this time are three (black squares in the figure) corresponding to the three position sensors 22b, 22c, and 22d, that is, lower right, upper left, and lower left on the paper surface. On the other hand, when the second wafer stage 6b has moved around the right side of the page, the encoder head moves to the lower right side of the page, which is the earliest position facing the reflector 24, as shown in FIG. The origin position is detected at the position. The encoder heads used at this time are three (black squares in the figure) corresponding to the three position sensors 23a, 23b, and 23d, that is, upper right, lower right, and lower left on the paper surface.

  Similarly, it is assumed that the wafer stage 6 moves from the exposure station 100 to the measurement station 200. At this time, when the wafer stage 6 moved from the exposure station 100 enters an area that can be measured by the encoder head (position sensors 22 and 23) in the measurement station 200, the encoder head detects the origin position. Here, when the first wafer stage 6a has moved around the left side of the drawing, the encoder head is located at the upper left position on the drawing, which is the earliest position facing the reflecting portion 25, as shown in FIG. Detect the origin position. The encoder heads used at this time are three (black squares in the figure) corresponding to the three position sensors 22a, 22c, and 22d, that is, upper right, upper left, and lower left in the drawing. On the other hand, when the second wafer stage 6b has moved around the right side of the page, the encoder head is positioned at the upper right side of the page, which is the earliest position facing the reflecting portion 25, as shown in FIG. The origin position is detected by the position. The encoder heads used at this time are the three heads (black square in the figure) corresponding to the three position sensors 23a, 23b, and 23c.

  On the other hand, the encoder head detects the origin position even when the wafer stage 6 enters an area that can be measured by the encoder in the measurement station 200 after exchanging the wafer W. In this case, as shown in FIG. 7E, the encoder head detects the origin position at the lower left position on the paper surface, which is the earliest position facing the reflecting portion 25. The encoder head used at this time is not limited to the left or right side of the wafer stage 6 in the drawing, and corresponds to the three position sensors 22b, 22c, 22d (23b, 23c, 23d). These are the three in the upper left (black squares in the figure).

  As described above, in the conventional exposure apparatus, even if the number of wafer stages 6 installed and the movement path are the same as those of the exposure apparatus 1 according to the present embodiment, the origin position is detected for each of the stations 100 and 200 by the sequence. Different combinations of encoder heads are used. Therefore, for example, when the relative position of each encoder head changes due to a change with time, a difference occurs in the change with time of the origin position at each station 100, 200, which may result in a reduction in the quality of the exposed wafer W. Is as described above.

  On the other hand, in the present embodiment, as shown in FIG. 2A, each of the reflectors 24 and 25 generates an origin signal, that is, an encoder head for detecting the origin position of the wafer stage 6. Origin patterns 26 and 27 are provided as origin positions. First, the reflection unit 24 in the exposure station 100 has six origin patterns 26a to 26f. Specifically, the origin pattern 26a is formed in the reflection portion 24a, the two origin patterns 26b and 26c are formed in the reflection portion 24b, the origin pattern 26d is formed in the reflection portion 24c, and the two origin patterns 26e and 26f are formed in the reflection portion 24d. is set up. Among these, the three origin patterns 26c, 26e, and 26f are the earliest positions at which the first wafer stage 6a has entered the observable range at the exposure station 100, and 1 for the three position sensors 22b, 22c, and 22d. It is arranged at a position facing each other. On the other hand, the other three origin patterns 26a, 26b, and 26d are the earliest positions at which the second wafer stage 6b has entered the observable range at the exposure station 100, and the three position sensors 23a, 23b, and 23d. They are arranged one by one at opposing positions.

  Similarly, the reflection unit 25 in the measurement station 200 has six origin patterns 27a to 27f. Specifically, the origin pattern 27a is formed in the reflection portion 25a, the two origin patterns 27b and 27c are formed in the reflection portion 25b, the origin pattern 27d is formed in the reflection portion 25c, and the two origin patterns 27e and 27f are formed in the reflection portion 25d. is set up. The three origin patterns 27c, 27e, and 27f are the earliest positions at which the wafer stage 6 completes entry into the observable range at the measurement station 200 from the carry-in hand 400a side, and the three origin sensors 23b, 23c, and 23d. They are arranged one by one at opposing positions. On the other hand, the other three origin patterns 27a, 27b, and 27d are the earliest positions at which the wafer stage 6 exits to the unloading hand 400b within the observable range of the measurement station 200, and the three position sensors 23a, 23b, and 23d. One at a time.

  With such a configuration, the wafer stage 6 moves to the exposure station 100 (or measurement station 200), and then stops at a position where the origin pattern 26 (or origin pattern 27) can be detected. Then, the encoder head, for example, uses the change in the intensity of another signal (origin signal) that does not affect the change in the intensity of the incremental signal due to the diffracted light to determine the origin position in a certain direction of the XY plane with the origin pattern 26. To detect. In addition, the laser interferometer detects the origin position in the Z-axis direction with respect to the reflection unit 24 (or the reflection unit 25) on the origin pattern 26 by using, for example, the phase difference between interference signals obtained from two wavelengths.

  FIG. 2B is a schematic plan view showing the state when the measurement station 200 is focused and the second wafer stage 6b is moved to the position where the wafer W is received as an example. At this time, the position sensors 23a to 23d on the second wafer stage 6b are outside the observable range and cannot observe the reflecting portions 25a to 25d. Therefore, also at this time, the encoder head and the laser interferometer of the second wafer stage 6b lose their origins with respect to the reflection unit 25. However, when receiving the wafer W in this way, position control with high resolution and high accuracy is not required. Therefore, in this case, the position of the second wafer stage 6b is controlled based on the result measured using another measuring device. As another measuring apparatus, for example, a scale is arranged on the stage surface plate 21, a lower resolution and lower accuracy encoder, a laser interferometer having a long measuring distance and a low cost, or a capacitance sensor. . Then, after receiving the wafer W, the second wafer stage 6b returns again to the observable range at the measurement station 200, and the origin position is detected as described above.

  Next, the flow of detection of the origin position of the wafer stage 6 in this embodiment will be described by taking the detection of the origin position of the second wafer stage 6b at the measurement station 200 as an example. FIG. 4 is a flowchart showing a flow of detection of the origin position of the second wafer stage 6b in the measurement station 200. FIG. 5 is a schematic plan view for explaining a combination of the position sensors 22 and 23 used at this time. First, the control unit 300 reads combination information of the position sensor 23 used when the second wafer stage 6b detects the origin position at the exposure station 100 from the storage device in the control unit 300 (step S101). In each combination of the position sensors 22 and 23 used for detecting the origin position in the exposure station 100, the situation where the origin position needs to be detected is only the replacement of the wafer stage 6 and the throughput is prioritized. Each wafer stage 6 is uniquely determined. For example, as shown in FIG. 5A, the first wafer stage 6a can be simultaneously observed by the position sensor 22b and the origin pattern 26c, the position sensor 22c and the origin pattern 26f, and the position sensor 22d and the origin pattern 26e. The origin position is detected at the position. On the other hand, as shown in FIG. 5B, the second wafer stage 6b can be simultaneously observed by the position sensor 23a and the origin pattern 26a, the position sensor 23b and the origin pattern 26b, and the position sensor 23d and the origin pattern 26d. The origin position is detected at the position. In this example, attention is paid to the second wafer stage 6b, so that the position sensors 23a, 23b, and 23d are read as combination information.

  Next, the control unit 300 determines the coordinate position of the second wafer stage 6b where the origin position can be detected by the combination of the position sensors 23 obtained in step S101 (step S102). When there are a plurality of candidates at this coordinate position, an appropriate coordinate position is determined according to a predetermined condition. For example, a coordinate position closest to the current position of the second wafer stage 6b can be set as an appropriate coordinate position here. Here, in the second wafer stage 6b, the position sensors 23a, 23b, and 23d are used for detecting the origin position. Therefore, as shown in FIG. 5C, the position where the position sensor 23a and the origin pattern 27a, the position sensor 23b and the origin pattern 27b, and the position sensor 23d and the origin pattern 27d can be observed simultaneously are the positions of the second wafer stage 6b. It is determined as a coordinate position.

  Next, the control unit 300 moves the second wafer stage 6b to the coordinate position determined in step S102 via the stage control unit (step S103).

  Next, the control unit 300 uses the position sensors 23a, 23b, and 23d to detect the origin position of the second wafer stage 6b (the origin position with respect to the origin patterns 27a, 27b, and 27d) (step S104). Here, the detection of the origin position of the second wafer stage 6b may be performed with the second wafer stage 6b stopped, or may pass through each origin pattern 27 while the second wafer stage 6b is moving. May be performed in combination with the following step S105.

  Then, the control unit 300 records the origin position detected in step S104 in the internal storage device (step S105). Thereafter, when the second wafer stage 6b is moved, the control unit 300 can move the second wafer stage 6b to a position that reflects the recorded origin position, thereby enabling high-accuracy positioning.

  Thus, since the exposure apparatus 1 first uses the encoder head in the existing linear encoder when detecting the origin position of the wafer stage 6, it is not necessary to separately install a photoelectric sensor or the like. In addition, in the exposure apparatus 1, a combination of a plurality of position sensors 22 and 23 used for detecting the origin position of the wafer stage 6 in one processing area is always used for detecting the origin position in the other processing area. Match the position sensor combination. Therefore, even if the relative positions of the individual encoder heads (position sensors 22, 23) change due to changes over time, for example, it is possible to suppress the occurrence of an error in the relative origin position between the processing regions. The origin position can be detected.

  As described above, according to this embodiment, it is possible to provide a lithography apparatus that is advantageous in terms of detecting the origin of the encoder.

  In the present embodiment, the detection of the origin position at the measurement station 200 after exchanging the wafer W has been described. However, the present invention relates to a case where the wafer stage 6 is outside the observable range other than exchanging the wafer W. Is also applicable. For example, as shown in FIG. 3, the present invention can also be applied to the detection of the origin position at the measurement station 200 when the wafer stages 6a and 6b are alternately replaced.

  Further, in the present embodiment, it has been described that the reflecting portions 24 and 25 are respectively held on the lens barrel surface plate 5 and the position sensors 22 and 23 are installed on the respective wafer stages 6a and 6b. On the other hand, the present invention can also be applied to a configuration in which the reflectors 24 and 25 are installed on the wafer stage 6 side and the position sensors 22 and 23 are held on the lens barrel surface plate 5 side. In this case, for example, the same effect as described above can be obtained by making the combination of the origin patterns 26 and 27 on the reflectors 24 and 25 used for detecting the origin position the same combination for each of the wafer stages 6a and 6b.

  In the present embodiment, the sensors for detecting the origin position are the position sensors 22 and 23, but it is also conceivable to use a detector provided separately from these. For example, the lens barrel surface plate 5 is provided with a light source and a photoelectric sensor, and a beam irradiated from the light source is reflected by corner cube mirrors installed at four corners on the wafer stage 6, and the reflected light is received by the photoelectric sensor. There may be a configuration for detecting the origin position. In this case, for example, the same effect as described above can be obtained by using the same combination of corner cube mirrors for detecting the origin position for each of the wafer stages 6a and 6b.

  Furthermore, in this embodiment, for example, a combination of the position sensors 22 and 23 used for detecting the origin position of the wafer stage 6 at the measurement station 200 is always used as the position sensor used for detecting the origin position at the exposure station 100. 22 and 23 are combined. However, the present invention is not limited to this. For example, taking into account the processing time required for detecting the origin position, the origin position detection operation of the present embodiment, the combination of the position sensors 22 and 23 having the shortest origin position detection time, and the movement coordinates of the wafer stage 6 are used. It is good also as a structure which switches detection operation suitably.

(Second Embodiment)
Next, a lithographic apparatus according to a second embodiment of the invention will be described. In the first embodiment described above, the shapes (sizes) of the reflecting portions 24 and 25 are uniform at the stations 100 and 200. On the other hand, the feature of this embodiment is that the shapes of the reflecting portions 24 and 25 are different from those of the first embodiment. FIG. 6 shows the arrangement of the reflecting portions 24 and 25 at the stations 100 and 200 and the wafer stages 6a and 6b as seen from the upper surface side (Z-axis direction plus side) in the exposure apparatus according to this embodiment. It is a schematic plan view which shows a position. Note that, for the sake of convenience, the same reference numerals are assigned to the components of the exposure apparatus according to the present embodiment that correspond to the components of the exposure apparatus 1 according to the first embodiment. In the example shown in FIG. 6, the reflection part 25d of the reflection parts 25 in the measurement station 200 has such a size that only the origin pattern 27d can be arranged. Further, as shown in FIG. 6A, the reflection unit 25c is a position sensor in a state in which the position sensors 23a, 23b, and 23d on the second wafer stage 6b can detect the origin patterns 27a, 27b, and 27d, for example. An origin pattern 27g is provided at a position where 23c can be detected. That is, the four origin patterns 27a, 27b, 27d, and 27g are arranged such that the four position sensors 22 (position sensors 23) on the wafer stage 6 can be observed simultaneously.

  In this case, the coordinate position of the wafer stage 6 determined in step S102 of FIG. 4 in the first embodiment is the position shown in FIG. 6B for both the wafer stages 6a and 6b in this embodiment. However, the combination information of the position sensor 23 read in step S101 is different for each of the wafer stages 6a and 6b. Therefore, for example, the position of the origin of the first wafer stage 6a is detected by the position sensors 22b, 22c and 22d observing the origin patterns 27b, 27d and 27g simultaneously. On the other hand, the origin position of the second wafer stage 6b is detected by observing the origin patterns 27a, 27b, and 27d simultaneously by the position sensors 23a, 23b, and 23d. Thus, according to this embodiment, even if the shape of the reflection parts 24 and 25 is not uniform as a whole, the same effects as those of the first embodiment can be obtained.

  In the above description, the twin-stage type exposure apparatus including the two wafer stages 6a and 6b is exemplified, but the present invention is not limited to this. For example, the present invention can be applied to a so-called multi-stage type exposure apparatus having two or more wafer stages, or an exposure in which one wafer stage moves between the processing regions in a plurality. It is also applicable to the device.

  In the above description, the exposure apparatus is exemplified as the lithography apparatus, but the present invention is not limited thereto. For example, the lithography apparatus may be a drawing apparatus that performs drawing on a substrate (photosensitive agent on the substrate) with a charged particle beam such as an electron beam, or an imprint material on the substrate is formed using a mold. It may be an imprint apparatus that forms (forms) a pattern on a substrate. In this case, the first area is changed not to the exposure station but to the drawing station or the imprint station as a forming part for forming the pattern. On the other hand, in the above description, the second area is a measurement station as a measurement unit that measures the wafer W, but may be a processing unit that performs processes other than the pattern formation process and the measurement process.

(Product manufacturing method)
The method for manufacturing an article according to an embodiment is suitable for manufacturing an article such as a micro device such as a semiconductor device or an element having a fine structure. The manufacturing method includes a step of forming a pattern (for example, a latent image pattern) on an object (for example, a substrate having a photosensitive agent on the surface) by using the above-described lithography apparatus, and a processing of the object on which the pattern is formed in the step. (For example, a development step). Further, the manufacturing method may include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, and the like). The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation or change is possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 6 Wafer stage 22 Position sensor 23 Position sensor 24 Reflection part 25 Reflection part 26 Origin pattern 27 Origin pattern 100 Exposure station 200 Measurement station

Claims (5)

A lithographic apparatus for forming a pattern on a substrate,
A movable stage holding the substrate;
A scale including an origin pattern; and a plurality of detectors for detecting signals from the scale, and one of the scale and the plurality of detectors is provided on the stage to measure the position of the stage An encoder for
For each of the first range and the second range included in the movable range of the stage, a signal from the origin pattern corresponding thereto is detected by each of a part of the plurality of detection units. Thus, the origin detection of the encoder is performed, and the combination of the plurality of detection units used for the origin detection with respect to the first range matches the combination of the plurality of detection units used for the origin detection with respect to the second range. A control unit for controlling the operation of the stage and the operation of the encoder;
A lithographic apparatus comprising:   The lithographic apparatus according to claim 1, wherein the movable range includes a range in which measurement by the encoder is impossible between the first range and the second range. The first range is a range for performing a process of forming the pattern on the substrate;
The lithographic apparatus according to claim 1, wherein the second range is a range in which a process different from the process performed in the first range is performed on the substrate.   The lithographic apparatus of claim 3, wherein the different processing includes metrology on the substrate. Forming a pattern on a substrate using the lithographic apparatus according to any one of claims 1 to 4,
Processing the substrate on which the pattern is formed in the step;
A method for producing an article comprising:

Images