JP2013179136A - Exposure system and device manufacturing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure system which is advantageous when a region not to be irradiated on by exposure light is formed in a specific region on a substrate.SOLUTION: The exposure system comprises: a douser, disposed on a surface conjugate with a substrate surface and including in its edge a circular arc overlapping a round boundary line on the inside from the circumference of the substrate defining a region on the substrate in which an image is formed, which shades light so that light is not incident on a circumferential region on the outside of the round boundary line on the substrate; a first drive unit which drives the douser to rotate around an axis parallel to the optical axis of an illumination system; a second drive unit which drives the douser linearly within a plane perpendicular to the optical axis; a detection unit which detects a shading position; and a control unit which, having a shading position at a reference point of time stored therein, calculates the amount of change in the shading position from a difference between the shading position detected by the detection unit at any point of time after the reference point of time and the shading position at the reference point of time (S102).

Description

  The present invention relates to an exposure apparatus and a device manufacturing method using the exposure apparatus.

  In a lithography process included in a manufacturing process of a semiconductor device, a liquid crystal display device, or the like, an exposure apparatus converts a pattern of an original (such as a reticle) into a photosensitive substrate (a wafer having a resist layer formed on the surface) via a projection optical system. Or a glass plate). Here, there is flip chip mounting as a method for mounting a semiconductor device on a wafer. The manufacturing process of the semiconductor device corresponding to the flip chip mounting includes a process of forming solder balls on the device (chip). Furthermore, there is a plating method as one method for forming the solder balls. In this plating method, in order to contact (conduct) the conductive film formed on the wafer and the electrode of the plating apparatus, a portion of the resist that is formed on the conductive film is previously contacted with the electrode. It is necessary to peel off. For example, when the resist is a negative resist, exposure light is not irradiated on the outer peripheral area of the wafer during exposure by the exposure apparatus. In order to realize this, Patent Document 1 discloses an apparatus in which a light shielding plate that shields the outer peripheral region during exposure is arranged on the upper surface of the wafer. Further, Patent Document 2 discloses a lithography apparatus in which a light shielding plate is arranged on a surface optically conjugate with the wafer surface, not on the wafer. In Patent Document 2, in order to define an exposure region corresponding to a peripheral shot region located in the outer peripheral region, a light shielding plate having a shape including an arc edge is rotationally driven around an axis parallel to the optical axis of the illumination optical system. Positioning is controlled by a first driving unit that performs the above and a second driving unit that performs linear driving in a vertical plane. According to this positioning control, the distance (light shielding width) from the outer periphery of the wafer to the boundary of the outer peripheral region shielded from light is constant for each peripheral shot region.

US Pat. No. 6,680,774 JP 2011-233781 A

  However, if the light shielding plate is arranged on the upper surface of the wafer as shown in Patent Document 1, it is necessary to retract the light shielding plate every time the wafer is replaced. Not desirable. On the other hand, as shown in Patent Document 2, when a light shielding plate is arranged on a surface optically conjugate with the wafer surface, a driving mechanism for the light shielding plate is installed in the apparatus. For example, in order to shield a desired position in any peripheral shot region by two-axis driving of rotation and linear motion, a second driving unit that further linearly drives on the first driving unit that rotates and rotates around the optical axis It becomes the configuration equipped with. Therefore, in consideration of directly measuring the position of the light shielding plate within the drive mechanism, it is difficult to arrange the sensor and the mounting portion. In addition, it is desirable that the rotation center of the first drive unit coincides with the optical axis from the viewpoint of optimizing the drive amount for improving the throughput. At this time, it is necessary to transmit rotation from the first drive unit to the light shielding plate due to the arrangement restriction of the light shielding plate near the rotation center serving as an optical path. There is a concern about deterioration. Such mechanical deterioration directly affects the light-blocking positioning accuracy. In particular, mechanical deterioration due to long-term use causes a change in the light-shielding position on the wafer, which may affect the product itself. .

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an exposure apparatus that is advantageous when forming a region where exposure light is not irradiated on a specific region on a substrate.

  In order to solve the above-described problems, the present invention is an exposure apparatus that irradiates a pattern formed on an original plate with light from an illumination system, and exposes an image of the pattern on a substrate via a projection optical system. Including an arc that overlaps with a circular boundary line on the inner side of the outer periphery of the substrate that is disposed on a plane conjugate with a substrate surface that is an object plane of the projection optical system in the system and that defines an area on which an image is formed on the substrate; A light shielding plate that blocks light so that light does not enter an outer peripheral region outside the circular boundary on the substrate, and a first drive unit that rotationally drives the light shielding plate about an axis parallel to the optical axis of the illumination system A second drive unit that linearly drives the light shielding plate in a plane perpendicular to the optical axis, a detection unit that detects a light shielding position shielded by the light shielding plate, and a light shielding position at a reference time point in advance, The light-shielding position detected by the detection unit at any time after It characterized in that it comprises a control unit for calculating the amount of variation in light-shielding position from the difference between the light shielding position at the point.

  ADVANTAGE OF THE INVENTION According to this invention, the exposure apparatus advantageous when forming the area | region where exposure light is not irradiated to the specific area | region on a board | substrate can be provided, for example.

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 structure of a light-shielding mechanism. It is a figure which shows the exposure area | region and light-shielding area | region on a wafer. It is a flowchart which shows the flow of the test | inspection sequence in 1st Embodiment. It is a figure which shows the light-shielding area | region at the time of the test | inspection in 1st Embodiment. It is a figure which shows the light-shielding area | region at the time of calculating | requiring the linear drive amount in 2nd Embodiment. It is a figure which shows the light-shielding area | region at the time of calculating | requiring the rotational drive amount in 2nd Embodiment.

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

(First embodiment)
First, the configuration of the exposure apparatus according to the first embodiment of the present invention will be described. The exposure apparatus of this embodiment is used in a lithography process in a manufacturing process of a semiconductor device or the like, and performs an exposure process on a wafer that is a substrate. Hereinafter, this exposure apparatus adopts a step-and-repeat method as an example, and is assumed to be a projection type exposure apparatus that projects and exposes a pattern formed on a reticle as an original on a wafer (on a substrate). FIG. 1 is a schematic diagram showing a configuration of an exposure apparatus 1 according to the present embodiment. In FIG. 1, a Z-axis is taken in parallel to the optical axis of the projection optical system, a Y-axis is taken in the scanning direction of the wafer during scanning exposure in a plane perpendicular to the Z-axis, and the non-axis perpendicular to the Y-axis is taken. An explanation will be given taking the X axis in the scanning direction. The exposure apparatus 1 includes an illumination optical system 2, a reticle stage that holds a reticle 3, a projection optical system 4, a wafer stage that holds a wafer 5, and a light shielding mechanism 6 that is installed on a wafer conjugate plane CPW. The control unit 7 is provided.

  The illumination optical system (illumination system) 2 adjusts the light emitted from the light source 8 and illuminates the reticle 3. The light source 8 of this embodiment is an ultra-high pressure mercury lamp, and irradiates the illumination optical system 2 while condensing light using a condensing mirror 9. The type of the light source 8 is not limited to a continuous light source such as an ultrahigh pressure mercury lamp, and may be a pulsed light source such as an ArF excimer laser having a wavelength of about 193 nm or an F2 excimer laser having a wavelength of about 153 nm. The condensing mirror 9 may be, for example, an elliptical mirror, but in addition to the elliptical mirror, a facet mirror optimized to increase the degree of condensing at the condensing point may be used. In this embodiment, as shown in FIG. 1, a masking blade 10 is installed on a wafer conjugate plane (hereinafter referred to as “conjugated plane”) CPW inside the illumination optical system 2. This masking blade 10 changes the area that illuminates the reticle 3 as an aperture with a variable aperture, so that the area outside the linear side that defines the outer edge of the shot area existing on the wafer 5 is changed. This is a first light shielding plate that blocks light from entering. That is, the masking blade 10 defines the shape of one shot area when the exposure apparatus 1 repeats the transfer for a plurality of shot areas existing on the wafer 5. Here, using the conjugate plane CPW as a reference, the illumination optical system 2 includes a first illumination optical system 2a between the light source 8 side and the conjugate plane CPW, and a conjugate stage CPW to a later-described reticle stage (reticle 3) side. And the second illumination optical system 2b. Among these, the first illumination optical system 2a specifies the shutter that adjusts the exposure amount to the wafer 5 by adjusting the opening and closing time, the fly-eye lens that produces uniform illuminance, and the light from the light source 8. Includes filters that cut out wavelengths. On the other hand, the second illumination optical system 2 b includes a masking imaging lens for irradiating the reticle 3 with an irradiation range defined by the masking blade 10.

  The reticle 3 is, for example, an original plate made of quartz glass, and a pattern (for example, a circuit pattern) to be transferred is formed. Although not shown, the reticle stage holds the reticle 3 and is movable at least in the XY-axis direction. Note that the position of the reticle 3 shown in FIG. 1 has the meaning of the reticle plane relative to the conjugate plane CPW. The projection optical system 4 projects and exposes the pattern on the reticle 3 illuminated with the irradiation light from the illumination optical system 2 onto the wafer 5 at a predetermined magnification (for example, 1/2 to 1/5). As the projection optical system 4, an optical system composed of only a plurality of optical elements, or an optical system composed of a plurality of optical elements and at least one concave mirror (catadioptric optical system) can be employed. . Alternatively, as the projection optical system 4, an optical system composed of a plurality of optical elements and at least one diffractive optical element such as a kinoform, an all-mirror optical system, or the like can be employed. The wafer 5 is a substrate made of single crystal silicon, for example, having a resist (photosensitive agent) applied on the surface thereof. The wafer 5 may be made of glass, sapphire, or a compound other than those made of single crystal silicon. Further, although not shown, the wafer stage is movable at least in the XY axis direction while placing and holding the wafer 5. Here, the position of the wafer 5 shown in FIG. 1 is the object plane of the projection optical system 4 and has the meaning of the wafer plane (substrate plane) with respect to the conjugate plane CPW.

  The light shielding mechanism 6 is installed on the conjugate plane CPW similarly to the masking blade 10 and blocks light from entering the outer peripheral region that is a predetermined width from the outer periphery of the wafer 5. FIG. 2 is a schematic diagram showing the configuration of the light shielding mechanism 6. The light shielding mechanism 6 first includes a second light shielding plate (light shielding plate) 11 including an arc that overlaps a circular boundary line inside the outer periphery of the wafer 5 at the edge. In addition, in the 2nd light shielding plate 11 shown in FIG. 2, although the location where the edge of circular arc is formed is made into the opening of the center part of a flat plate part, this is an example, for example, the circular arc is formed in the outer peripheral side of a flat plate part. There may be a configuration that forms an edge. The light shielding mechanism 6 is a driving mechanism for changing the position of the second light shielding plate 11, and the first driving unit 12 that rotates around an axis parallel to the optical axis of the illumination optical system 2 and a vertical plane. And a second drive unit 13 that drives linearly. The light shielding mechanism 6 is also similar to the masking blade 10 in that the shape of the shot area is defined according to the exposure position when the exposure apparatus 1 repeatedly exposes the shot area. In particular, in the light shielding mechanism 6, in order to shield a desired position in any outer peripheral shot region by rotating and linear biaxial driving, as shown in FIG. It is desirable that the second drive unit 13 that drives linearly is mounted. Furthermore, it is desirable that the rotational center of the rotational drive in the first drive unit 12 at this time coincides with the optical axis. As described above, installing the masking blade 10 and the second light shielding plate 11 of the light shielding mechanism 6 on the conjugate plane CPW in one illumination optical system 2 is acceptable. It will be placed at a defocused position within the range. At this time, it is desirable to arrange the second light shielding plate 11 in a position optically conjugate with the wafer 5, that is, in alignment with the conjugate plane CPW, and in a position where the masking blade 10 is defocused. If the defocus amount in the arrangement is not allowable, the shape of the shot area is determined by a Cr (chrome) pattern on the reticle 3, and the masking blade 10 prevents transfer due to Cr defects on the reticle 3. The light may be shielded in an area larger than the shape of the shot area. Further, the order of the arrangement positions of the masking blade 10 and the light shielding mechanism 6 in the illumination optical system 2 is not particularly limited, and either may be on the light source 8 side. Further, if it is necessary to suppress the influence of the defocus amount on the arrangement, the illumination optical systems having different optically conjugate positions may be separately arranged.

  Further, as a mechanism related to the masking blade 10 and the light shielding mechanism 6, the exposure apparatus 1 includes a detection unit 14 that detects a light shielding position by the light shielding mechanism 6. The detector 14 is a line or spot light quantity detector mounted on the wafer stage. The detection surface of the detection unit 14 is appropriately moved by driving the wafer stage, and coincides with the image plane of the exposure light when detecting the light shielding position. The control unit 7 to be described later calculates a light shielding position on the wafer 5 from the detection result by the detection unit 14 and the stage coordinates of the wafer stage. Here, the calculated light shielding position refers to a boundary between the light shielding area and the exposure area formed by the masking blade 10 or the second light shielding plate 11 of the light shielding mechanism 6 at the time of detection.

  The control unit 7 can control the operation and adjustment of each component of the exposure apparatus 1. The control unit 7 is configured by, for example, a computer, and is connected to each component of the exposure apparatus 1 via a line, and can control each component according to a program or the like. The control unit 7 of the present embodiment executes at least the calculation of the light shielding position with reference to the detection result obtained from the detection unit 14 and the operation control of the light shielding mechanism 6. Note that the light shielding mechanism control unit that independently controls the driving of the first drive unit 12 and the second drive unit 13 of the light shielding mechanism 6 may be configured separately from the control unit 7. Further, the control unit 7 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.

Next, light shielding with respect to the outer peripheral region on the wafer 5 by the light shielding mechanism 6 will be specifically described. First, the arrangement of the shot area as the transfer area on the wafer 5 and the position of the light shielding area will be described. FIG. 3 is a plan view showing a plurality of shot regions C arranged on the surface of the wafer 5 and an outer peripheral region R which is a light shielding region. In general, the area where the exposure apparatus can transfer the pattern in one exposure is determined by the imaging area of the projection optical system, but is usually smaller than the size of the wafer 5. Therefore, the exposure apparatus 1 repeats pattern transfer (exposure) while stepping the wafer 5 by the step-and-repeat method as described above. Among the plurality of shot areas C shown in FIG. 3, a shot area C ₁ indicated by oblique lines indicates an area where a pattern is transferred by one exposure, and the same pattern is formed on the entire surface of the wafer 5 by repeated exposure. Can be transferred.

Here, assuming that a semiconductor device is flip-chip mounted in a series of semiconductor device manufacturing processes including a lithography process by the exposure apparatus 1, the series of processes may include a process of forming solder balls. . In the process of forming the solder balls, there must be a region where the resist is peeled off on the wafer 5 in order to make contact (conduction) between the conductive film on the surface of the wafer 5 and the electrode of the plating apparatus. . As shown in FIG. 3, the region where the resist has been peeled is a peripheral portion on the surface of the wafer 5, specifically, an outer peripheral region R which is a certain width (light-shielding width) d from the outer periphery of the wafer 5. Equivalent to. For example, when the resist applied to the wafer 5 is a negative resist, the outer peripheral region R needs to be shielded from light during exposure. That is, when the pattern is transferred to the peripheral shot region C ₂ where the peripheral portion of the wafer 5 exists, the exposure apparatus 1 needs to specify and expose the transfer region for the peripheral shot region C ₂ individually. The light shielding of the outer peripheral region R is performed by changing the position of the second light shielding plate 11 by the first driving unit 12 that rotationally drives the light shielding mechanism 6 and the second driving unit 13 that drives linearly. In the present embodiment, as described below, the change in the light shielding position on the wafer 5 after use is simply detected from the initial value in the rotational attitude, and the drive offset is reflected in the driving of the second light shielding plate 11. Thus, mechanical deterioration of the light shielding mechanism 6 is corrected. However, at this time, the light shielding width d needs to be within an allowable accuracy, and if it is not within the accuracy, a warning to that effect is issued.

  FIG. 4 is a flowchart showing an operation sequence (hereinafter referred to as “inspection sequence”) for detecting a change in the light shielding position in the present embodiment. Prior to this inspection sequence, the control unit 7 keeps the second light-shielding plate 11 of the light-shielding mechanism 6 at a specific inspection position at a reference time, and at the inspection position detected by the detection unit 14. A light shielding position (initial value) and a threshold value are stored in advance. Here, when the light shielding position is detected by the detection unit 14, the control unit 7 adjusts the detection surface of the detection unit 14 to the imaging surface in the state of the inspection position. The reference time is, for example, a time when a new second light shielding plate 11 is installed in the light shielding mechanism 6 and normal exposure processing is started, that is, immediately after the installation position of the second light shielding plate 11 is adjusted. Say time. Further, the initial value and threshold value of the light shielding position are set in the control unit 7 and stored (stored) in the storage unit 7a. The inspection position is a representative position extracted from the wafer layout (arrangement of shot areas set on the wafer 5) set in the inspection sequence, and is not limited to one place, and may be a plurality of places. Good. Further, the initial value of the light shielding position may be measured in advance in accordance with the start of use of the light shielding mechanism 6, or may use data accumulated in advance. Further, the threshold value is a reference value that is determined to be a state where the light shielding width d is acceptable (impossible). When the control unit 7 starts the inspection sequence at an arbitrary time, first, the first driving unit 12 and the second driving unit 13 of the light shielding mechanism 6 are driven to position the second light shielding plate 11 at the inspection position ( Step S100). Here, the arbitrary time point means that a certain time has elapsed from the reference time point, and there is a possibility that a deviation from a desired position occurs at the time point when inspection is required, that is, the light shielding position by the second light shielding plate 11. Say time. Next, the control unit 7 aligns the detection surface of the detection unit 14 with the imaging surface in the state of the inspection position, and causes the detection unit 14 to detect the light shielding position (step S101). Next, the control unit 7 calculates the change amount of the light shielding position from the difference between the light shielding position (initial value) stored in advance and the light shielding position detected in step S101 (step S102). At this time, the amount of change in the light shielding position is obtained by subtracting the light shielding position at an arbitrary time point detected from the light shielding position (initial value). Next, the control unit 7 determines whether or not the change amount of the light shielding position derived in step S102 is a value smaller than the previously stored threshold value (change amount of the light shielding position <threshold value) (step S103). Here, when the control unit 7 determines that the amount of change in the light shielding position is smaller than the threshold (YES), the control unit 7 reflects the amount of change in the driving offset of the light shielding mechanism 6 and the second light shielding plate during normal exposure. 11 is corrected (step S104). That is, the corrected drive amount is obtained by adding the change amount of the light shielding position to the (original) drive amount at an arbitrary time point. When there are a plurality of inspection positions, a plurality of offsets can be used in accordance with the amount of change in the light shielding position at each position. In addition, when the drive offset is reflected on the light shielding mechanism 6, the control unit 7 may automatically perform it, or the offset amount may be set (input) manually. On the other hand, if the control unit 7 determines in step S103 that the amount of change in the light shielding position is equal to or greater than the threshold (the amount of change in the light shielding position ≧ the threshold) (NO), the controller 7 is outside the exposure apparatus 1 (for example, an operator) A warning to that effect is issued (step S105). The threshold value may be set as a fixed value in advance. For example, the test wafer is exposed and developed at a reference time point to inspect the accuracy of the light shielding position, and the completion accuracy inherent to the apparatus is confirmed. The allowable amount of change in the light shielding position obtained in this way may be used. Further, a plurality of threshold values may be set instead of only one, and the control unit 7 may warn the change of the light shielding position in a stepwise manner based on the plurality of threshold values. By this warning, the operator can determine that the mechanical deterioration of the light shielding mechanism 6 has progressed, and can perform maintenance at an appropriate time. The control unit 7 periodically and repeatedly executes such an inspection sequence during the operation period of the exposure apparatus 1.

  Here, in the exposure apparatus 1, the reticle 3 is disposed between the light shielding mechanism 6 and the wafer 5 when viewed on the optical path of the exposure light. Therefore, when detecting the light shielding position as described above, May be affected. Therefore, for example, the control unit 7 drives the reticle stage to remove the reticle 3 from the exposure light irradiation region before step S100 in the inspection sequence shown in FIG. It is desirable to prevent the pattern from entering. Note that the movement of the reticle 3 is performed before step S100, and may be performed between step S100 and step S101, for example. In order to avoid the influence of the reticle pattern, there is a method in which a dedicated inspection reticle having no pattern is prepared in advance and mounted on the reticle stage in place of the normal reticle 3 at the time of inspection. Further, the control unit 7 may set the inspection sequence start condition that the reticle 3 is not mounted.

  Further, the control unit 7 detects the light shielding position in step S101 in the inspection sequence as described below, so that the change in the light shielding position is caused by rotational driving or is caused by linear driving. It is judged whether it is. FIG. 5 is a plan view illustrating an example of a light shielding region on the detection surface (imaging surface) of the detection unit 14 in a state where the second light shielding plate 11 is positioned at the inspection position by the light shielding mechanism 6. Here, on the region 19 corresponding to the outer shape of the shot region C on the detection surface, the light shielding region 20 is formed in accordance with the shape and position of the second light shielding plate 11 so as to overlap the region 19. That is, the arc end 20a of the light shielding area 20 is a boundary with the exposure area. In this inspection position, the rotation center 21 at the light shielding position (rotation drive of the first drive unit 12) is arranged near the center of the region 19. Particularly in this case, the arc end 20a overlaps the rotation center 21 as shown in FIG. Under such a state, the detection unit 14 sets two detection areas 22 (first detection area 22a and second detection area 22b indicated by dotted lines in FIG. 5) on the area 19, and these detection areas are set. Each point where 22 and the arc end 20a intersect is detected as a light shielding position. Among these, the first detection region 22a detects the light shielding position at the point where the rotation center 21 and the arc end 20a overlap, and therefore the light shielding position detected in the first detection region 22a is determined by the light shielding mechanism 6. Little affected by rotational drive. Therefore, if a change occurs in the light shielding position detected in the first detection region 22a, it can be considered that it is caused by a positional deviation of linear drive. Here, P22a (t) is the light shielding position coordinate of the first detection region 22a at an arbitrary time point, and P22a (1) is the light shielding position (initial value) coordinate of the first detection region 22a at the reference time point, the first detection. It is assumed that the change amount of the light shielding position in the region 22a is (P22a (t) −P22a (1)). At this time, the control unit 7 can determine that the light shielding position change has occurred in the linear drive of the light shielding mechanism 6 by an amount of (P22a (t) −P22a (1)). On the other hand, the second detection region 22b is separated from the rotation center 21 in a direction toward the side end of the region 19 overlapping the arc end 20a, and detects at least one light shielding position close to the side end. Therefore, the light shielding position detected in the second detection region 22b can change due to the rotational displacement and linear drive of the light shielding mechanism 6 and the respective positional deviations. Here, P22b (t) is set as the light shielding position coordinate of the second detection area 22b at an arbitrary time point, and P22b (1) is set as the light shielding position (initial value) coordinate of the second detection area 22b at the reference time point. It is assumed that the amount of change in the light shielding position in the region 22b is (P22b (t) −P22b (1)). At this time, the controller 7 determines that the light shielding position change has occurred in the rotational drive of the light shielding mechanism 6 by the amount of (P22a (t) −P22a (1)) − (P22b (t) −P22b (1)). Can do. By referring to these, the control unit 7 causes the change in the light shielding position to be caused by the first driving unit 12 that rotates the light shielding mechanism 6 or the second driving unit 13 that performs linear driving. It can be judged whether it is a thing. Therefore, the control unit 7 presents the cause of the change in the light shielding position to the operator, for example, so that the operator can appropriately apply to the drive unit of the light shielding mechanism 6 identified as the cause of the change in the light shielding position. Maintenance can be performed. In FIG. 5, the detection area away from the rotation center 21 is only one place of the second detection area 22b, but may be a plurality of places. Further, FIG. 5 shows two inspection positions in which the light-shielding region 20 extends along either the X-axis direction or the Y-axis direction separately in FIGS. 5A and 5B. The rotational drive position in the position may be an arbitrary position and an arbitrary number.

  As described above, the exposure apparatus 1 may inspect the accuracy of the light shielding position after exposing and developing the test wafer for each inspection even if the light shielding mechanism 6 is mechanically deteriorated and the light shielding position is changed. It is possible to easily correct without taking a simple method. In addition, when the amount of change in the light shielding position exceeds an allowable threshold value, the exposure apparatus 1 issues a warning to the outside, so that the influence on the product itself due to the change in the light shielding position can be suppressed in advance. Further, when detecting the change in the light shielding position, the control unit 7 can also identify the drive unit that caused the change in the light shielding position. Inspection man-hours can be reduced as much as possible.

  As described above, according to the present embodiment, it is possible to provide an exposure apparatus that is advantageous when forming a region where exposure light is not irradiated on a specific region on a wafer.

(Second Embodiment)
Next, an exposure apparatus according to the second embodiment of the present invention will be described. In the exposure apparatus 1 of the first embodiment, when obtaining a change in the light shielding position, the absolute position with reference to the coordinates on the region 19 is referred to. On the other hand, the exposure apparatus of the present embodiment is characterized in that the change in the light shielding position is obtained by referring to the change from the initial value of the relative driving amount of the light shielding mechanism 6 to the time of inspection. Here, in order to obtain a change in the relative drive amount of the light shielding mechanism 6, the control unit 7 refers to the detection results of the light shielding positions at a plurality of inspection positions. Hereinafter, in the exposure apparatus of this embodiment, the same components as those of the exposure apparatus 1 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 6 is a plan view showing an example of a light shielding region according to the present embodiment corresponding to FIG. 5 according to the first embodiment, and particularly at an inspection position for calculating the relative drive amount of the linear drive of the light shielding mechanism 6. In this state, the second light shielding plate 11 is positioned. Among these, FIG. 6A and FIG. 6B show a state where the rotational driving posture of the light shielding mechanism 6 is made constant and linear driving is performed in time series. The detection unit 14 includes two detection regions 23 (first detection region 23a and second detection region 23b indicated by dotted lines in the drawing) in the axial direction of the linear drive (X-axis direction in FIG. 6) passing through the rotation center 21. Set. First, in the first state shown in FIG. 6A, the control unit 7 causes the detection unit 14 to detect a point where the first detection region 23a and the arc end 20a intersect as a light shielding position. Subsequently, the control unit 7 moves (positions) the second light shielding plate 11 with respect to the light shielding mechanism 6 so as to be in the second state shown in FIG. A point where the end 20a intersects is detected as a light shielding position. Here, P23a (t) is a light shielding position coordinate of the first detection area 23a at an arbitrary time point, and P23a (1) is a light shielding position (initial value) coordinate of the first detection area 23a at a reference time point. Further, P23b (t) is the light shielding position coordinate of the second detection area 23b at an arbitrary time point, and P23b (1) is the light shielding position (initial value) coordinate of the second detection area 23b at the reference time point. At this time, the control part 7 can calculate the relative drive amount at the time of being in the inspection position from (P23a (t) −P23b (t)) − (P23a (1) −P23b (1)).

  FIG. 7 is a plan view and an explanatory view showing an example of a light shielding region according to the present embodiment corresponding to FIG. 5 according to the first embodiment, and particularly for calculating the relative drive amount of the rotational drive of the light shielding mechanism 6. In this state, the second light shielding plate 11 is positioned at the inspection position. Among these, FIG. 7A and FIG. 7B show a state in which the rectilinear drive posture of the light shielding mechanism 6 is fixed and the rotational drive is performed in time series. In this case, the detection unit 14 does not overlap with the rotation center 21 on the region 19, and as a detection position in the first state shown in FIG. 7A, first, a linear drive shaft that passes through the rotation center 21. The first detection region 24a is set in the direction (X-axis direction in FIG. 7A). Further, the detection unit 14 is separated in both directions in the direction (the Y-axis direction in FIG. 7A) from the rotation center 21 toward the side edge of the region 19 that overlaps the arcuate end 20 a, and the light shielding position close to these side edges. A second detection area 24b and a third detection area 24c to be detected are set. Similarly, the detection unit 14 does not overlap with the rotation center 21 on the region 19, and as a detection position in the second state shown in FIG. 7B, first, a linear drive shaft that passes through the rotation center 21. The fourth detection region 24d is set in the direction (Y-axis direction in FIG. 7B). Furthermore, the detection unit 14 is separated in both directions in the direction (X-axis direction in FIG. 7B) from the rotation center 21 toward the side edge of the region 19 that overlaps the arc edge 20a, and the light shielding position close to these side edges. A fifth detection area 24e and a sixth detection area 24f to be detected are set. That is, in the state shown in FIGS. 7A and 7B, there are three detection areas. First, in the first state shown in FIG. 7A, the control unit 7 shields each of the detection regions from the first detection region 24a to the third detection region 24c and the point where the circular arc end 20a intersects by the detection unit 14. Let it be detected as a position. Next, the control unit 7 calculates the first center 25 of the arc end 20a in the first state as shown in FIG. 7C from the three light shielding positions. Subsequently, in the second state shown in FIG. 7B, the control unit 7 blocks the points where the detection regions 14d to 24f intersect the arc ends 20a by the detection unit 14. Let it be detected as a position. Next, the control unit 7 calculates the second center 26 of the arc end 20a in the second state as shown in FIG. 7C from the three light shielding positions. Then, the control unit 7 sets an angle 27 formed by a line connecting the rotation center 21 and the first center 25 and a line connecting the rotation center 21 and the second center 26 to the second light shielding plate 11 at the inspection position. It can be the relative driving amount at the time. In the example shown in FIG. 7, the number of detection areas is set to three in each state of FIGS. 7A and 7B. However, in order to obtain a more precise relative drive amount. It is good also as three or more places. Further, in FIGS. 6 and 7, the relative drive amount is obtained from each of the two inspection positions, but the posture or number of the inspection positions is arbitrary.

  Furthermore, the relative drive amount calculated as described above can be applied to the inspection sequence shown in FIG. 4 according to the first embodiment. When this relative drive amount is applied to the inspection sequence of FIG. 4, the calculated relative drive amount is used as the light shielding position at the inspection position. For example, in step S103, the control unit 7 determines whether the difference between the initial value of the relative drive amount and the value at the time of inspection is equal to or less than a threshold value. As described above, according to the present embodiment, the control unit 7 can determine whether the mechanical deterioration has progressed by rotational driving or linear driving of the light shielding mechanism 6 as in the first embodiment. . If the relative drive amount is applied to the inspection sequence of FIG. 4, in step S104, the drive amount is not the drive offset, for example, if the relative drive amount is increased by 1%, the drive amount is 101% actual drive at the time of driving. The proportion may be corrected.

(Device manufacturing method)
Next, a method for manufacturing a device (semiconductor device, liquid crystal display device, etc.) according to an embodiment of the present invention will be described. A semiconductor device is manufactured through a pre-process for producing an integrated circuit on a wafer and a post-process for completing an integrated circuit chip on the wafer produced in the pre-process as a product. The pre-process includes a step of exposing a wafer coated with a photosensitive agent using the above-described exposure apparatus, and a step of developing the wafer. The post-process includes an assembly process (dicing and bonding) and a packaging process (encapsulation). A liquid crystal display device is manufactured through a process of forming a transparent electrode. The step of forming the transparent electrode includes a step of applying a photosensitive agent to a glass substrate on which a transparent conductive film is deposited, a step of exposing the glass substrate on which the photosensitive agent is applied using the above-described exposure apparatus, and a glass substrate. The process of developing is included. According to the device manufacturing method of the present embodiment, it is possible to manufacture a higher quality device than before.

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

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Illumination optical system 3 Reticle 4 Projection optical system 5 Wafer 7 Control part 11 2nd light shielding plate 12 1st drive part 13 2nd drive part 14 Detection part

Claims (8)

An exposure apparatus that irradiates a pattern formed on an original plate with light from an illumination system and exposes an image of the pattern on a substrate via a projection optical system,
The illumination system is disposed on a plane conjugate with a substrate surface that is an object plane of the projection optical system, and overlaps a circular boundary line inside the outer periphery of the substrate that defines a region on which the image is formed on the substrate. A light-shielding plate that includes a circular arc at an edge and blocks light so that light does not enter an outer peripheral region outside the circular boundary line on the substrate;
A first drive unit that rotationally drives the light shielding plate around an axis parallel to the optical axis of the illumination system;
A second drive unit that linearly drives the light shielding plate in a plane perpendicular to the optical axis;
A detection unit for detecting a light shielding position shielded by the light shielding plate;
The light shielding position at the reference time is stored in advance, and the light shielding position is determined from the difference between the light shielding position detected by the detection unit at an arbitrary time after the reference time and the light shielding position at the reference time. A control unit for calculating the amount of change;
An exposure apparatus comprising:   The detection unit detects the light shielding position at a rotation center of the light shielding position on the substrate and at least one point away from the rotation center in a direction toward the side edge of the region overlapping the circular boundary line. The exposure apparatus according to claim 1, wherein a position is set. The control unit drives the light shielding plate to a plurality of positions by the first driving unit or the second driving unit, and refers to the light shielding positions obtained at a plurality of detection positions at the plurality of positions. To calculate the driving amount,
The relative drive amount at a reference time point is stored in advance, and at any time point, the relative drive amount is calculated from the difference between the relative drive amount at the arbitrary time point and the relative drive amount at the reference time point. The exposure apparatus according to claim 1, wherein the amount of change is calculated.   The control unit corrects the change by reflecting the change amount in a drive offset of the first drive unit or the second drive unit when the change amount does not exceed a reference value determined to be an unacceptable state. The exposure apparatus according to any one of claims 1 to 3, wherein:   4. The exposure apparatus according to claim 1, wherein the control unit issues a warning when the amount of change exceeds a reference value determined to be an unacceptable state. 5.   6. The exposure apparatus according to claim 1, wherein the control unit causes the original to be removed from the light irradiation region when the detection unit detects the light shielding position. 7.   6. The control unit according to claim 1, wherein when the detection unit detects the light shielding position, the control unit is configured to install an original plate that does not have the pattern instead of the original plate. Exposure equipment. A step of exposing the substrate using the exposure apparatus according to claim 1;
Developing the exposed substrate;
A device manufacturing method comprising:

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