JP2006024681A - Apparatus and method for position measurement, and aligner and method for exposure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable measurement of position of a mark on a wafer with high precision. <P>SOLUTION: An exposure apparatus 1 is provided with a surface state inspection device 30 which has an imaging apparatus 22c for inspecting surface state of a wafer W held on a wafer holder 15. Imaging data D2 imaged by the imaging apparatus 22c are supplied to a main control system 20, and defective distribution on the wafer W is computed. Based on the defective distribution, the main control system 20 selects a mark for instrumentation from marks formed on the wafer W, and location information of the selected mark for instrumentation is measured by using an alignment detection system AS. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention uses a position measurement apparatus and position measurement method for measuring position information of a position measurement pattern formed on a substrate such as a wafer or an object, and position information obtained by using the position measurement apparatus or position measurement method. The present invention relates to an exposure apparatus and an exposure method for aligning a wafer and exposing and transferring a pattern formed on a mask onto the wafer.

  Semiconductor elements, liquid crystal display elements, and other devices are generally manufactured using photolithography technology. Photolithography is a technique in which a mask or reticle (hereinafter referred to as a mask when these are collectively called) on which a fine pattern is formed is irradiated with illumination light, and the mask pattern is applied to a wafer or glass coated with a photosensitive agent such as a photoresist. This is a technique for transferring onto a substrate such as a plate, developing a photosensitive agent to form a resist pattern on the substrate, and performing various processes such as etching on the substrate using the resist pattern. In general, a device is manufactured by repeating the above-described series of processes a plurality of times and forming a plurality of different patterns on the substrate.

  When manufacturing a device, it is necessary to accurately align a pattern already formed on a substrate with a pattern to be formed next. For this reason, when a pattern is formed on a substrate, an alignment mark (position measurement pattern) is formed in association with a region where the pattern is formed (shot region), and the substrate is formed when the next pattern is formed. By measuring the position information of the mark formed above, the array coordinates of each shot area are obtained, and based on this position information, the mask on which the pattern to be transferred next is formed and each shot area are aligned. Then, the pattern is transferred.

  The arrangement coordinates of each shot area on the substrate are obtained by EGA (enhanced global alignment) calculation. This EGA calculation measures mark position information associated with a predetermined number (several to several tens) of sample shots (shots to be measured) in a shot area set on a substrate. Statistical processing is performed using the measurement results to determine the array coordinates of all shot areas on the substrate.

  By the way, in recent years, CMP (Chemical Mechanical Polishing) processing is frequently performed on a substrate as one of device manufacturing processes. This CMP process uses a slurry (chemical abrasive), a polishing pad, etc., and mechanically scrapes the surface (the surface on which the pattern is formed) associated with the multi-layer structure of the device, thereby flattening or reducing the film thickness. It is processing to do.

  In this CMP process, the substrate surface is mechanically polished, so that scratches (scratches) may occur due to the slurry, or defects such as particles contained in the slurry being embedded in the substrate surface may occur. Further, the surface of the substrate that has been subjected to the CMP process is subjected to a cleaning process, and the slurry adhering to the surface of the substrate is washed away. However, a part of the slurry may remain as a residue without being washed away. When these defects are formed on the mark (if they remain), there is a problem that the position information of the mark may be erroneously measured. When a defect is formed on a mark associated with a sample shot, there is a problem that an array coordinate of a shot area obtained by an EGA calculation using the measurement result of the mark is also incorrect.

  Further, in recent semiconductor elements, wiring is often formed using Cu (copper) having a low electric resistance in order to suppress heat generation, and in order to remove an excess portion of wiring formed on the substrate, Cu− A CMP process is performed. In this Cu-CMP process, a portion where polishing is insufficient tends to be distributed on a specific portion on the substrate, for example, a scribe line (street line). Since marks associated with shot areas are often formed on scribe lines, it is often possible that the positional information of marks formed at places where polishing is insufficient cannot be accurately measured. There was a problem. That is, when the mark is located at a location where polishing is insufficient, there is a problem that the array coordinates of the shot area cannot be obtained accurately even if the EGA calculation using the measurement result of the mark is performed.

  The present invention has been made in view of such problems of the prior art, and a position measuring apparatus and method capable of measuring position information of a position detection pattern formed on a substrate with high accuracy, and To provide an exposure apparatus capable of exposing and transferring a mask pattern to each shot area on a substrate in a state where the mask and the substrate are aligned with high accuracy based on position information measured using the apparatus or method. With the goal.

  Hereinafter, in the description shown in this section, the present invention will be described in association with the member codes shown in the drawings representing the embodiments. However, each constituent element of the present invention is limited to the members shown in the drawings attached with these member codes. Is not to be done.

In order to solve the above problem, according to the first aspect of the present invention, the positions of a plurality of position measurement patterns (Mx _i , My _i ) formed on a substrate (W) on which a circuit pattern is to be formed. A position measuring device for measuring information, the inspection means (30) for inspecting the surface state of the substrate on the substantially entire surface on the side where the pattern for position measurement is formed, and the inspection result of the inspection means Based on the selection means (45) for selecting a predetermined number of position measurement patterns as a measurement target pattern from the plurality of position measurement patterns formed on the substrate, and the selection means selected by the selection means There is provided a position measurement device comprising measurement means (AS) for measuring position information of a measurement target pattern.

In order to solve the above problem, according to a second aspect of the present invention, the positions of a plurality of position measurement patterns (Mx _i , My _i ) formed on a substrate (W) on which a circuit pattern is to be formed. A position measurement method for measuring information, wherein an inspection step (S3) for inspecting a surface state over substantially the entire surface of the substrate on which the position measurement pattern is formed, and an inspection result of the inspection step And a selection step (S4) for selecting a predetermined number of position measurement patterns as a measurement target pattern from among the plurality of position measurement patterns formed on the substrate, and the selection selected in the selection step There is provided a position measurement method comprising a measurement step (S5) for measuring position information of a measurement target pattern.

  In these inventions, since the position measurement pattern is selected based on the inspection result of the surface state of the substrate, the position measurement pattern existing in the portion where the surface state is not good is omitted from the measurement target pattern, and the surface state is By measuring the position information using the position measurement pattern existing in a good part as the measurement target pattern, the position information of the position measurement pattern can be measured with high accuracy.

According to a third aspect of the present invention, there is provided a substrate stage (WST) configured to be movable while holding a substrate (W), and a pattern of a mask (R) is formed on the substrate (shot region (WST)). In the exposure apparatus (1) for exposing and transferring to each of ES _i ), statistical calculation is performed using position information of the measurement target pattern measured by the position measurement apparatus according to the first aspect of the present invention, and the plurality Calculating means (47) for obtaining positional information of the shot area, and positioning of the mask and the shot area on the substrate are controlled by moving the substrate stage based on the positional information obtained by the computing means. There is provided an exposure apparatus having an alignment apparatus (20) for performing.

According to a fourth aspect of the present invention, in the exposure method for exposing and transferring the pattern of the mask (R) to each of the shot regions (ES _i ) formed on the substrate (W), the second aspect of the present invention. An exposure method including an alignment step (S6, S7) for aligning the substrate and the mask based on the position information of the measurement target pattern measured by the position measurement method according to the above is provided.

  In these inventions, based on the position information measured by the position measurement device according to the first aspect or the position measurement method according to the second aspect, the position information of the position measurement pattern can be measured with high accuracy. Since the mask and the shot area on the substrate are aligned, the pattern already formed on the substrate and the mask pattern can be superimposed with high accuracy.

  According to the present invention, there is an effect that position information of a position measurement pattern can be measured with high accuracy.

  In addition, since the pattern already formed on the substrate and the pattern of the mask can be superimposed with high accuracy, high-quality and high-performance devices can be manufactured with high yield and high efficiency. There is an effect of becoming.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing an outline of the overall configuration of an exposure apparatus according to an embodiment of the present invention. The exposure apparatus 1 sequentially transfers a pattern formed on the reticle R onto the wafer W while relatively moving the reticle R as a mask and the wafer W as a substrate with respect to the projection optical system PL. Is a step-and-scan exposure apparatus.

  In the following description, an XYZ rectangular coordinate system is set in the drawing, and the positional relationship of each member will be described with reference to the XYZ rectangular coordinate system as necessary. The XYZ orthogonal coordinate system in FIG. 1 is set so that the X axis and the Y axis are parallel to the wafer W, and the Z axis is set in a direction orthogonal to the wafer W. 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, the direction in which the reticle R and the wafer W are moved synchronously (hereinafter referred to as the scanning direction) is set in the Y direction. Hereinafter, this coordinate system may be referred to as a stationary coordinate system.

  The exposure apparatus 1 holds an illumination system 10 that emits exposure illumination light, a reticle stage RST as a mask stage that holds a reticle R as a mask, a projection optical system PL, and a wafer W as a substrate in an XY plane. A wafer stage device 16 on which a substrate table 14 as a substrate stage moving in an XY two-dimensional direction is mounted, a part of a surface state inspection device (inspection means) that images the outer edge shape of the wafer W and detects the surface state of the wafer W A pre-alignment detection system RAS that also functions as an alignment detection system AS that detects an alignment mark (position measurement pattern) formed on the wafer W, and a control system for these. Here, the diameter of the wafer W is about 300 mm here.

The illumination system 10 includes a light source unit, a shutter, an optical integrator, a beam splitter, a condenser lens system, a reticle blind, an imaging lens system, and the like (all not shown). Examples of the light source unit include excimer laser light sources such as KrF excimer laser light source (oscillation wavelength 248 nm) or ArF excimer laser light source (oscillation wavelength 193 nm), F ₂ laser light source (oscillation wavelength 157 nm), harmonics of copper vapor laser light source and YAG laser. A generator or an ultrahigh pressure mercury lamp (g-line, i-line, etc.) can be used.

  The illumination light emitted from the light source unit enters the optical integrator (here, fly-eye lens) when the shutter is open, and when the illumination light enters the optical integrator, a large number of light source images are incident on the exit-side focal plane. A surface light source, that is, a secondary light source is formed. The illumination light emitted from the optical integrator reaches the reticle blind through the beam splitter and the condenser lens system. Illumination light that has passed through the reticle blind is emitted toward the mirror 11 as illumination light IL through the imaging lens system, and the optical path is bent vertically downward (−Z direction) by the mirror 11 and held on the reticle stage RST. The rectangular illumination area IAR on the reticle R is illuminated.

  On reticle stage RST, reticle R is fixed by vacuum suction. In order to position reticle R, reticle stage RST is two-dimensionally (in the direction perpendicular to optical axis AX of projection optical system PL, in the X direction, the Y direction perpendicular to the X direction and the Z axis perpendicular to the XY plane). It is configured to be movable (in the direction of rotation). The reticle stage RST is movable on a reticle base (not shown) at a scanning speed designated in the scanning direction (Y direction) by a reticle driving unit (not shown) constituted by a linear motor or the like. .

  A movable mirror 12 that reflects a laser beam from a laser interferometer (hereinafter referred to as a “reticle interferometer”) 13 is fixed on the reticle stage RST, and the position of the reticle stage RST in the stage moving surface is determined by the reticle interferometer. 13 is always detected with a predetermined resolution. Here, actually, on the reticle stage RST, a movable mirror (or at least one corner cube mirror) having a reflecting surface orthogonal to the scanning direction (Y direction) and orthogonal to the non-scanning direction (X direction). A movable mirror having a reflecting surface is provided, and a reticle interferometer 13 is also provided for one axis or a plurality of axes for each movable mirror. In FIG. 1, these are typically the movable mirror 12 and the reticle interferometer 13. As shown respectively.

  Position information (or velocity information) RPV of reticle stage RST from reticle interferometer 13 is sent to stage control system 21 and main control system 20 through this, and stage control system 21 responds to an instruction from main control system 20. The reticle stage RST is driven via a reticle drive unit (not shown) based on the position information of the reticle stage RST.

  The projection optical system PL has an optical axis AX in the Z direction. Here, the projection optical system PL is a birefringent optical system having a predetermined reduction magnification (for example, 1/5, 1/4, or 1/6). A catadioptric optical system or a reflective optical system may be used. When the illumination region IAR of the reticle R is illuminated by the illumination light IL from the illumination system 10, the circuit pattern of the reticle R in the illumination region IAR is passed through the projection optical system PL by the illumination light IL that has passed through the reticle R. The reduced image (partially inverted image) is projected onto the exposure area IA on the wafer W whose surface is coated with a photoresist.

  Wafer stage WST is driven by, for example, a two-dimensional linear actuator on base BS in the Y direction (the left-right direction in FIG. 1) that is the scanning direction and in the X direction (the direction perpendicular to the paper surface in FIG. 1) perpendicular to the Y direction. It has become. A substrate table 14 is provided on wafer stage WST. A wafer holder 15 is placed on the substrate table 14, and the wafer W is held by the wafer holder 15 by vacuum suction. Wafer stage WST, substrate table 14, and wafer holder 15 constitute wafer stage device 16.

  The substrate table 14 is supported at three points on the wafer stage WST via three actuators, and these are independently driven in the Z direction, whereby the wafer W held on the substrate table 14 is moved. The surface position (Z direction position and inclination with respect to the XY plane) is set to a desired state.

  A movable mirror 18 that reflects a laser beam from a laser interferometer (hereinafter referred to as “wafer interferometer”) 19 is fixed on the substrate table 14, and the position of the substrate table 14 in the XY plane is fixed by the wafer interferometer 19. Is always detected with a predetermined resolution. Here, actually, a movable mirror 18Y having a reflecting surface orthogonal to the Y direction that is the scanning direction and a moving mirror 18X having a reflecting surface orthogonal to the X direction that is the non-scanning direction are provided on the substrate table 14. The wafer interferometers 19X and 19Y are provided for one axis or a plurality of axes for each movable mirror (see FIG. 2). However, in FIG. 1, these are typically shown as a movable mirror 18 and a wafer interferometer 19, respectively.

  The position information (or speed information) WPV of the substrate table 14 is sent to the stage control system 21 and the main control system 20 through this, and the stage control system 21 receives the position information (or speed) in response to an instruction from the main control system 20. Information) Based on WPV, wafer stage WST is controlled via wafer drive unit 17. On the substrate table 14, various reference marks for measuring the distance from the detection center of an off-axis alignment detection system AS described later to the optical axis AX of the projection optical system PL are formed. A reference member (not shown) is fixed.

  The pre-alignment detection system RAS is held by a holding member (not shown) at a position separated from the projection optical system PL. The pre-alignment detection system RAS includes three pre-alignment sensors 22 a, 22 b, and 22 c that detect the positions of three outer green portions of the wafer W that are conveyed by a wafer loader (not shown) and held by the wafer holder 15. Here, the configuration of the pre-alignment detection system RAS will be described with reference to FIG.

  As shown in FIG. 2, the outer peripheral portion of the wafer W has a circular shape, and an orientation flat OF which is a linear cutout is formed in a part thereof. The pre-alignment sensors 22a and 22b are respectively arranged at positions where the vicinity of both ends of the orientation flat OF is imaged. Further, the pre-alignment sensor 22c is disposed at a position for imaging a part of the outer edge position of the wafer W other than the portion where the orientation flat OF is formed. In the example shown in FIG. 2, when the orientation flat OF of the wafer W is arranged parallel to the X axis and below the pre-alignment sensors 22 a and 22 b (−Z direction), the wafer W extends from the center to the −X direction. The pre-alignment sensor 22c is arranged at a position where the outer periphery of the wafer W that is positioned can be photographed. The relative positional relationship between the pre-alignment sensors 22a, 22b, and 22c is determined in advance.

  These pre-alignment sensors 22a, 22b, and 22c are output from the image pickup device such as a CCD, an optical system that forms an optical image incident from below (-Z direction) on the image pickup surface of the image pickup device, and the image pickup device. And an image processing circuit that performs image processing of the image signal. In addition, any one or a plurality of pre-alignment sensors 22a, 22b, and 22c provided in the pre-alignment system RAS are used as a part of the surface state inspection apparatus for inspecting the surface state of the wafer W. In the present embodiment, it is assumed that the pre-alignment sensor 22c is used as part of the surface state inspection apparatus.

  The surface condition inspection apparatus includes a scratch formed on a wafer W that has been subjected to a CMP process, embedding particles contained in a slurry used in the CMP process on the wafer W, a slurry residue on the wafer W, and a wafer W. This is an apparatus for inspecting the coating unevenness of the resist applied thereon as the surface state of the wafer W. In the surface condition inspection apparatus, the pre-alignment sensor 22c is used as a light receiving device that receives reflected light, diffracted light, and the like from the surface of the wafer W.

  FIG. 3 is a view showing a configuration of a surface state inspection apparatus provided in the exposure apparatus 1 of the present embodiment. The surface condition inspection apparatus 30 includes a detection illumination system 30a for irradiating the surface of the wafer W held on the wafer holder 15 with detection illumination light, reflected light from the wafer W by irradiating the detection illumination light, diffracted light, and the like. And an imaging optical system 30b that collects the light and a pre-alignment sensor 22c.

  The detection illumination system 30a performs wavelength selection by transmitting a discharge light source 31 such as a metal halide lamp, a collector lens 32 for condensing the illumination light beam from the discharge light source 31, and transmitting the illumination light beam collected by the collector lens 32. The wavelength selection filter 33, a neutral density filter 34 that performs dimming, and an input lens 35 that condenses the illumination light flux that has passed through the wavelength selection filter 33 and the neutral density filter 34 are configured. The illumination light focused by the input lens 35 is introduced into one end 36 a of the fiber 36.

  Here, the wavelength selection filter 33 is provided in a disk (turret) 33b having a switching drive mechanism 33a, and several types of filters can be switched and used. For example, an interference filter that transmits only light of a specific wavelength such as g-line (wavelength 436 nm), i-line (wavelength 365 nm), a band-pass filter that transmits light of a specific wavelength band, or light having a wavelength longer than a predetermined wavelength A sharp cut filter or the like that transmits only the light can be selected and used as necessary. The neutral density filter 34 is composed of a disk-like filter in which the amount of transmitted light sequentially changes according to the rotation angle, and is configured to be able to control the amount of transmitted light by being rotationally controlled by the rotation drive mechanism 34a.

  The detection illumination system 30a further includes an illumination system concave mirror 37 that receives the divergent light beam emitted from the other end 36b of the fiber 36, and the fiber 36 is located at a position substantially away from the illumination system concave mirror 37 by its focal length. The other end 36b is disposed. For this reason, the illumination light introduced into one end 36 a of the fiber 36 and emitted from the other end 36 b of the fiber 36 toward the illumination system concave mirror 37 is converted into a parallel light beam by the illumination system concave mirror 37 and held by the wafer holder 15. The surface of W is irradiated.

At this time, the illumination light beam applied to the surface of the wafer W is incident on the axis AX1 (vertical axis) perpendicular to the surface of the wafer W at an angle θ _i and is emitted at an angle θ _r . The relationship between the incident angle θ _i and the emission angle θ _r can be adjusted by tilting (tilting) the wafer holder 15 about an axis AX2 (for example, an axis parallel to the X axis) parallel to the surface of the wafer W. is there. That is, the relationship between the incident angle θ _i and the exit angle θ _r can be adjusted by changing the mounting angle of the wafer W by tilting the wafer holder 15.

  Light emitted from the surface of the wafer W (here, diffracted light is used) is collected by the imaging optical system 22c. The pre-alignment sensor 22c images reflected light from the wafer with an image sensor. Here, the size of the measurement visual field MV of the pre-alignment sensor 22c is set to such a size that a part of the wafer W is photographed.

  The surface state inspection apparatus 30 does not inspect the surface state of the wafer W in detail, but performs a so-called macro inspection that inspects the state over the entire surface of the wafer W. For this reason, it is desirable that the size of the measurement visual field MV is originally set to such a size that the entire wafer W can be photographed at once. However, in this embodiment, since the pre-alignment sensor 22c used during pre-alignment is also used by the surface state inspection apparatus 30, the size of the measurement visual field MV is set smaller than the size of the wafer W. The surface state inspection apparatus 30 of the present embodiment performs macro inspection on the entire wafer W by taking in light from each part of the wafer W while moving the wafer stage WST.

  The detailed configuration of the surface state inspection apparatus 30 is disclosed in Japanese Patent Laid-Open No. 2002-162368. Alternatively, a magnification switching mechanism may be arranged in the pre-alignment system 22c so that a wider range can be inspected at a time. As an example, the magnification switching mechanism 30b may be retracted outside the measurement visual field of the pre-alignment sensor 22c during pre-alignment, and disposed within the measurement visual field of the pre-alignment sensor 22c during the surface condition inspection of the wafer W. Also, the measurement time can be shortened by providing the same functions as 22c to 22a and 22b and simultaneously measuring them.

  Returning to FIG. 1, imaging data D <b> 1 of the outer edge of the wafer W during pre-alignment using the pre-alignment detection system RAS is supplied to the main control system 20. The imaging data D1 includes imaging result data DA by the pre-alignment sensor 22a, imaging result data DB by the pre-alignment sensor 22b, and imaging result data DC by the pre-alignment sensor 22c. In addition, image data D <b> 2 captured by the pre-alignment sensor 22 c when inspecting the surface state of the wafer W is also output to the main control system 20. Based on the orientation information of the wafer obtained in D1, the wafer is rotated and set in a predetermined direction, then placed on the wafer holder and moved under the alignment detection system AS.

  The alignment detection system AS is arranged on the side surface of the projection optical system PL, and in this embodiment, the image is formed to measure a scribe line (street line) and a position detection mark (fine alignment mark) formed on the wafer W. An off-axis alignment microscope consisting of an alignment sensor is used. The detailed configuration of the alignment detection system AS is disclosed in, for example, Japanese Patent Laid-Open No. 9-219354 and US Pat. No. 5,859,707. Image data D3 of the wafer W observed by the alignment detection system AS is supplied to the main control system 20.

  Further, in this exposure apparatus, the measurement point set in the exposure area IA (the area on the wafer W optically conjugate with the illumination area IAR described above) and its neighboring area respectively in the Z direction ( A multi-point focus position detection system (not shown), which is one of oblique detection type focus detection systems (focus detection systems) for detecting the position in the optical axis AX direction), is provided. The multi-point focus position detection system includes an irradiation optical system including an optical fiber bundle, a condensing lens, a pattern forming plate, a lens, a mirror, and an irradiation objective lens, a condensing objective lens, a rotational direction vibration plate, an imaging lens, The light receiving optical system is composed of a light receiving slit plate and a light receiver having a number of photosensors (all not shown). The detailed configuration of this multipoint focus position detection system is disclosed in, for example, Japanese Patent Laid-Open No. 6-283403 and US Pat. No. 5,448,332 corresponding thereto.

  Next, the main control system 20 will be described. FIG. 4 is a block diagram showing the configuration of the main part of the main control system 20 provided in this exposure apparatus. The main control system 20 includes an image data storage unit 41, a wafer design data storage unit 42, a wafer position error calculation unit 43, a defect distribution calculation unit 44, a mark selection unit 45, a mark position information calculation unit 46, a shot array calculation unit 47, And a control unit 48.

  The image data storage unit 41 includes imaging data D1 output from the pre-alignment detection system RAS (pre-alignment sensors 22a to 22c), imaging data D2 output from the pre-alignment sensor 22c when inspecting the surface state of the wafer W, and Each of the image data D3 output from the alignment detection system AS is temporarily stored. The wafer design data storage unit 42 stores design coordinates of shot areas on the wafer W (shot map data) and design coordinate values of marks (fine alignment marks) associated with the shot areas.

Here, the shot area set on the wafer W will be briefly described. FIG. 5 is a diagram showing an example of an array of shot areas set on the wafer W. As shown in FIG. It should be noted that an example in which many scratches are generated around the shot ES ₃ (sample shot SA ₂ ) on the wafer of FIG. As shown in FIG. 5, a coordinate system (x, y) different from the stationary coordinate system (X, Y) shown in FIG. 1 is set on the wafer W, and along this coordinate system (x, y). Shot areas ES ₁ , ES ₂ ,..., ES _M (M is an integer of 3 or more) are regularly formed. In each shot area ES _i (i = 1 to M), a chip pattern is formed by the process so far. Each shot area ES _i is delimited by a scribe line having a predetermined width extending in the x direction and the y direction, and an X-axis mark Mx is provided at the center of the scribe line extending in the x direction in contact with each shot area ES _{i. i} is formed, and a Y-axis mark My _i is formed at the center of the scribe line extending in the y direction in contact with each shot region ES _i . As an example, the size of the shot area ES _i is about 30 mm square, and the width of the scribe line is about 50 to 80 μm.

Mark Mx _i and mark My _i for the Y-axis of the X-axis are those formed by arranging three linear pattern at a predetermined pitch in the x and y directions, respectively, the recess in the base of these patterns the wafer W, convex It is formed as a pattern of part or embedding. Coordinate system on the wafer W (x, y) marks the x coordinate (coordinate value in design) of Mx _{i x i,} and y-coordinate (coordinate value in design) of the mark My _i in _{y i} are known, It is stored in the wafer design data storage unit 42 described above. In this case, the x coordinate of the mark Mx _i and the y coordinate of the mark My _i are regarded as the x coordinate and the y coordinate of the shot area ES _i , respectively.

In addition, a predetermined number of shot areas are selected in advance as sample shots (sample areas) among the plurality of shot areas ES _{1 to} ES _M set on the wafer W. In the example shown in FIG. 5, nine shot areas with diagonal lines are selected as sample shots SA _{1 to} SA ₉ . Each of the sample shots SA _{1 to} SA ₉ is provided with marks Mx and My. For example, the sample shot SA ₁ is provided with marks Mx ₁ and My ₁ , respectively. It is assumed that more scratches are generated on the mark provided accompanying the sample shot SA ₂ (shot ES ₃ ) than other marks.

  Returning to FIG. 4, the wafer position error calculation unit 43 performs image processing on the imaging data D1 stored in the image data storage unit 41 to obtain the position of the orientation flat OF formed on the wafer W, and the substrate table 14. A position error and a rotation amount of the wafer W from the reference position set in advance above are calculated. The position error and the rotation amount calculated by the wafer position error calculation unit 43 are output to the control unit 48.

  The defect distribution calculation unit 44 performs comparison processing between the imaging data D2 stored in the image data storage unit 41 and the image (inspection reference image) of the surface of the non-defective wafer stored in advance, or has been learned in advance. The presence / absence inspection of the difference from the feature of the inspection reference image is performed, and the defect distribution on the wafer W is calculated. Here, the distribution calculated by the defect distribution calculation unit 44 is performed on the scratch distribution, slurry residue distribution, resist coating unevenness distribution, and wafer W surface formed on the wafer W by performing the CMP process. The distribution of reflectance or spectral characteristics due to variations in various processes such as etching, and the distribution of remaining substances after the cleaning process. These appear as non-uniformity in the shape (unevenness) of the surface of the wafer W, nonuniformity in reflectance, and nonuniformity in spectral characteristics.

For example, when obtaining the distribution of scratches, the defect distribution calculation unit 44 sets the threshold value TH shown in FIG. 6 for the imaging data D2 subjected to the above-described inspection for the presence of a difference, and a signal exceeding the threshold value TH It is determined that a pixel obtained from the above is a pixel obtained by imaging a scratch formed on the wafer W, that is, a pixel obtained by imaging a defective portion. FIG. 6 is a diagram for explaining an example of processing performed by the defect distribution calculation unit 44. The defect distribution calculation unit 44 performs the above processing over the entire imaging data D2 to obtain the distribution on the wafer W. Distribution of defects, for example, expressed by each shot area ES _i number of defects included in these every (defective pixel count), or on the wafer W is divided into a predetermined plurality of areas for each of these divided regions It can be expressed by the number of defects included in these. Further, when calculating the distribution of the resist coating unevenness, the defect distribution calculating unit 44 calculates the color unevenness or light / dark stripes captured by the alignment sensor 22c. An example of the width of the scratch is about 100 μm.

The mark selection unit 45 is a measurement target mark (measurement target pattern) used for EGA calculation when determining the arrangement of the shot areas ES _i on the wafer W by EGA calculation based on the defect distribution obtained by the defect distribution calculation unit 44. Make a selection. The mark selection unit 45 abstractly selects marks Mx and My included in a shot area or a divided area having no or few defects as the measurement target marks. More specifically, the mark selection unit 45 obtains uniformity (a degree of a small number of defects) for each shot region, and accompanies the shot region where the uniformity is equal to or greater than a predetermined threshold (second level). The mark to be measured is selected from the marks Mx and My to be measured, or the uniformity is obtained for each divided region, and the uniformity is included in the divided region where the uniformity is equal to or higher than a predetermined threshold (first level). A measurement target mark is selected from marks Mx and My associated with each shot area.

If the marks Mx and My are arbitrarily selected by such processing, for example, if only the mark formed in the central portion of the wafer W is selected, the linear expansion / contraction of the wafer W, which is a parameter used in the EGA calculation, is selected. The accuracy such as (scaling) or offset (parallel movement of the wafer W) may deteriorate, and the error may increase. Therefore, the mark selection unit 45 obtains uniformity (degree of a small number of defects) for each of the sample shots SA _{1 to} SA ₉ set in a distributed manner, and the uniformity is a predetermined threshold value (second level). A mark to be measured is selected from the marks Mx and My accompanying the sample shots SA _{1 to} SA ₉ as described above, or uniformity is obtained for each divided region, and the uniformity is determined in advance by a predetermined threshold value ( The measurement target mark may be selected from the marks Mx and My associated with the sample shots SA _{1 to} SA ₉ included in the divided area that is equal to or higher than the first level. At this time, the mark formed at a position that does not require a long time to be arranged in the field of view of the alignment detection system AS is preferentially selected, or the uniformity is selected as much as possible. It is even better if the selection is made in consideration of factors. In the above description, the number of sample shots is nine, but considering these, it is desirable to set about 16 or 32 sample shots.

  Further, in the above description, selection is performed by comparison with a predetermined threshold value set in advance, but the uniformity for each shot area or each divided area is relatively set without setting such a threshold value. You may make it select by evaluating. For example, a standard deviation may be calculated for the uniformity of each shot area or each divided area, and the standard deviation may be used as a threshold value.

  The mark position information calculation unit 46 performs image processing on the image data D3 stored in the image data storage unit 41, that is, the image data D3 imaged by the alignment detection system AS, and the mark Mx formed on the wafer W. , My position information (sample shot position information) is calculated. Specifically, for example, aliasing autocorrelation processing, template matching processing using a predetermined template, or edge position measurement processing (processing for obtaining the contour of a mark, the edge position of each mark element forming a mark from the obtained contour The position information of the sample shot is calculated by performing a process such as a process for detecting the mark and a process for obtaining the mark center from the detected edge position. The position information calculated here is position information on the (x, y) coordinate system set on the wafer W. Here, the mark imaged by the alignment detection system AS is the mark selected by the mark selection unit 45 described above. Alternatively, all the image data D3 of the sample shot may be collected by AS, and the position information may be calculated only for the mark selected by the data D2.

The shot array calculation unit 47 performs an EGA operation using the position information calculated by the mark position information calculation unit 46 and the shot map data stored in the wafer design data storage unit 42, and the array coordinates of each shot area ES _i Is calculated. Specifically, first, the sample shot position information (position information on the wafer W) calculated by the mark position information calculation unit 46 and the position information WPV of the substrate table 14 when each sample shot is measured by the alignment detection system AS. The position information (measured value) of the sample shot on the stationary coordinate system (XYZ coordinate system) is obtained from the above. Next, a determinant that converts the design coordinate value of the sample shot into the actual sample shot position is set, and the design coordinate value for each of the sample shots is substituted into this determinant, and the design coordinate value is set. A plurality of determinants that show the relationship between the calculated coordinate value and the calculated coordinate value are obtained. Then, the determinant is determined so that the difference between the actually measured value and the calculated coordinate value is minimized. By substituting the coordinate value of each shot area ES _i into the determined determinant, the array coordinates on the stationary coordinate system of all shot areas are calculated.

The control unit 48 outputs a control signal to each of the wafer position error calculation unit 43 to the shot arrangement calculation unit 47 so as to obtain a position error and a rotation amount with respect to a reference position at the time of pre-alignment, and defect distribution on the wafer W. (Uniformity) is calculated, a mark used for EGA calculation is selected, EGA calculation is performed using the selected mark, and the array coordinates of the shot area ES _i are calculated. Further, to control the positioning of the wafer stage WST by supplying stage control data CD to the stage control system 21 based on the arrangement coordinates of the calculated shot areas ES _i, position information (speed information) of the reticle R during exposure RPV Based on the position information (velocity information) WPV of the wafer W, the stage control data CD is supplied to the stage control system 21 to scan the reticle stage RST and the wafer stage WST.

  Further, the control unit 48 performs switching operation control of the wavelength selection filter 33 by the switching drive mechanism 33a provided in the surface state inspection apparatus 30 shown in FIG. 3 and rotation control of the neutral density filter 34 by the rotation drive mechanism 34a. Stage control data CD is output to the stage control system 21 to perform rotation control of the wafer holder 15 around the axis AX1, tilt control of the wafer holder 15 around the axis AX2, and the like.

  In FIG. 4, the case where each block is configured in hardware and the main control system 20 is configured by combining these is illustrated as an example. However, in terms of hardware, the main control system 20 may be configured as a computer system, and the functions of the blocks constituting the main control system 20 may be realized by a program built in the main control system 20. Further, when the main control system 20 is configured as a computer system, it is not always necessary to incorporate all the programs for realizing the functions of the respective blocks constituting the main control system 20 in the main control system 20 in advance. Rather, the programs for realizing the functions of the above blocks are stored in a recording medium, read out from the recording medium when necessary, and then installed via a communication network using the Internet or the like. You can also.

  Next, the operation during exposure will be described. FIG. 7 is a flowchart showing an outline of the operation of the exposure process of this exposure apparatus. Here, it is assumed that the pattern formed in the previous process is formed in each shot area on the wafer W. Further, the flowchart shown in FIG. 7 shows processing for one wafer W, and the processing shown in FIG.

  When the exposure process is started, first, a reticle R on which a pattern to be transferred is formed from a reticle library (not shown) using a reticle loader (not shown) is loaded on the reticle stage RST. Further, a wafer W to be exposed is loaded onto the substrate table 14 (on the wafer holder 15) by a wafer loader (not shown) (step S1).

  Next, the main control system 20 (more specifically, the control unit 48 (see FIG. 4)) outputs a control signal to the stage control system 21 to drive the wafer stage WST via the wafer driving device 17, thereby The pre-alignment sensors 22a, 22b, and 22c are moved to imaging positions. Specifically, the orientation flat OF formed on the wafer W is positioned directly below the pre-alignment sensors 22a and 22b, and a part of the outer edge position of the wafer W other than the portion where the orientation flat OF is formed is directly below the pre-alignment sensor 22c. The wafer W is moved so as to be positioned at the position.

  When the movement of the wafer W is completed, the vicinity of the outer edge of the wafer W is imaged using the pre-alignment sensors 22a, 22b, and 22c. Image data D1 of the wafer W imaged by the pre-alignment sensors 22a, 22b, and 22c is supplied to the main control system 20. The imaging data D1 supplied to the main control system 20 is temporarily stored in the image data storage unit 41 (see FIG. 4). When the imaging data D1 is stored in the image data storage unit 41, a control signal is output from the control unit 48 to the wafer position error calculation unit 43, whereby the wafer position error calculation unit 43 causes the position error relative to the reference position of the wafer W and Processing for calculating the amount of rotation is performed (step S2). The position error and the rotation amount with respect to the reference position of the wafer W obtained by this processing are output to the control unit 48 and are used as correction values when driving the wafer stage WST thereafter.

  When the pre-alignment of the wafer W is completed, the control unit 48 emits the illumination light beam from the discharge light source 31 provided in the surface state inspection apparatus 30 shown in FIG. 3, and controls the switching drive mechanism 33a to activate the wavelength selection filter 33. The neutral density filter 34 is controlled to rotate by switching and controlling the rotation drive mechanism 34a. Further, the stage control data CD is output to the stage control system 21 to perform rotation control of the wafer holder 15 about the axis AX1, tilt control of the wafer holder 15 about the core axis AX2, and the like. Then, wafer stage WST is driven in the X direction or Y direction, and reflected light, diffracted light, and the like from the surface of wafer W are imaged by pre-alignment sensor 22c while moving wafer W at a constant speed. At this time, the tilt control of the wafer holder 15 is set so that, for example, the contrast is the best.

Imaging data D2 captured by the pre-alignment sensor 22c is supplied to the main control system 20 and temporarily stored in the image data storage unit 41. When the imaging data D2 is stored in the image data storage unit 41, a control signal is output from the control unit 48 to the defect distribution calculation unit 44, and the imaging data D2 and an image of the surface of the non-defective wafer stored in advance (inspection reference image) ) And a defect determination process using the threshold value TH shown in FIG. 6 are performed, and the number of defects included in each shot area ES _i is obtained. In this way, the defect distribution (uniformity) is obtained, and the surface state inspection (macro inspection) of the entire wafer W is performed (step S3).

When the surface state of the wafer W is inspected, a control signal is output from the control unit 48 to the mark selection unit 45, and a process of selecting a sample shot based on the surface state inspection result is performed (step S4). Specifically, for example, among sample shots SA _{1 to} SA ₉ , sample shots in which the number of defects obtained by the surface condition inspection exceeds a preset threshold value (that is, uniformity is less than a predetermined threshold value). Except for this, a defect whose number of defects is equal to or less than a preset threshold value (that is, uniformity is equal to or greater than a predetermined threshold value) is selected. In this way, a sample shot with a low defect rate is selected. In the case of the example shown in FIG. 5, since many scratches are generated in the region around the sample shot SA ₂ (shot SE ₃ ), this sample shot SA ₂ is a sample used for EGA calculation. It is excluded from the shot (also excluded from the position measurement process in the later step S5).

  When the number of sample shots selected here is larger than a preset number (the maximum number of marks used for EGA calculation), for example, marks associated with each sample shot are sequentially placed in the measurement field of view of the alignment detection system AS. Select the sample shot with the shortest total time required for placement. Information on the selected sample shot is output to the control unit 48.

  When the above processing is completed, the control unit 48 outputs stage control data CD to the stage control system 21 and moves the wafer stage WST in the XY plane, thereby accompanying the sample shot selected by the mark selection unit 48. The marks are sequentially arranged in the measurement visual field of the alignment detection system AS and imaged. The mark image data D3 captured by the alignment detection system AS is supplied to the main control system 20 and temporarily stored in the image data storage unit 41.

  When imaging of all the selected marks is completed, a control signal is output from the control unit 48 to the mark position information calculation unit 46. Thereby, the mark position information calculation unit 46 performs processing such as folding autocorrelation processing, template matching processing using a predetermined template, or edge position measurement processing on the image data D3, and is selected in step S4. The position information of each sample shot is calculated (step S5). The calculated position information is output to the shot array calculation unit 47.

Next, a control signal is output from the control unit 48 to the shot arrangement calculation unit 47. Based on this control signal, the shot array calculation unit 47 performs EGA calculation based on the position information of the sample shot obtained by the mark position information calculation unit 46 and the shot map data stored in the wafer design data storage unit 42, The arrangement coordinates of all shot areas ES _i on the wafer W are calculated (step S6). The calculated array coordinates are output to the control unit 48.

  When the above processing is completed, the wafer W is exposed (step S7). In this exposure operation, first, the substrate table 14 is moved so as to be a scanning start position for exposure of the first shot area (first shot) on the wafer W. In this movement, each of the arrangement coordinates calculated in step S6 is corrected with a baseline amount (distance between the projection area center of the projection optical system PL and the measurement visual field center of the alignment detection system AS) obtained in advance with high accuracy. This is performed by the main control system 20 via the stage control system 21 and the wafer driving device 17 based on the arrayed coordinate values and the position information (speed information) from the wafer interferometer 19. At the same time, the reticle stage RST is moved so that the XY position of the reticle R becomes the scanning start position. This movement is performed by the main control system 20 via a stage control system 21 and a reticle driving unit (not shown).

  Next, the stage control system 21 responds to a control command from the main control system 20, the Z position information of the wafer W detected by the multipoint focus position detection system, and the XY of the reticle R measured by the reticle interferometer 13. Based on the position information and the XY position information of the wafer W measured by the wafer interferometer 19, the surface position of the wafer W is adjusted via the reticle driving unit and the wafer driving device 17 (not shown), and the reticle R and the wafer. The scanning exposure is performed by relatively moving W.

  When the exposure of the first shot area is completed by the above processing, the substrate table 14 is moved so as to be the scanning start position for the exposure of the next shot area, and the XY position of the reticle R is set to the scanning start position. The reticle stage RST is moved so that Then, scanning exposure relating to this shot area is performed in the same manner as the first shot area described above. Thereafter, scanning exposure is performed on each shot area in the same manner, and the exposure is completed. When the exposure of wafer W is completed, wafer stage WST is moved to the unload position, and then wafer W is unloaded from substrate table 14 by a wafer unloader (not shown) (step S8). Thus, the exposure process for one wafer is completed.

  In the above description, it is assumed that the processing shown in FIG. However, when a lot consisting of a plurality of wafers is processed, the processing shown in FIG. 7 is performed only on the wafer at the beginning of the lot, and the sample selected on the wafer at the beginning of the lot is applied to the remaining wafers in the lot. Position information of shots (marks attached to sample shots) may be measured, and position information of all shot areas may be obtained by EGA calculation. This shortens the time required for the surface state inspection of the wafer W, which is desirable for improving the throughput.

  By the way, when detecting the surface state of the wafer W, since an already formed pattern is simultaneously imaged along with defects such as scratches and slurry residues, in the above, the non-defective wafer stored in advance with the imaging data D2 A comparison with an image (inspection reference image) on the surface of the wafer (the wafer having almost no defects as described above) is performed to identify the defective portion. However, when the same pattern is formed in each shot area, the data (number of defective pixels) is totaled for each sample shot based on the result of imaging including the already formed pattern. By setting a threshold value that also takes into account, or comparatively evaluating these values, it is possible to identify shots with few defects and shots with many defects (defective shots) and exclude marks related to the defective shots. Then, the measurement target mark may be selected.

  In addition, patterns that have already been formed (patterns that should be originally formed on the substrate, hereinafter referred to as circuit patterns) and defect patterns (such as scratches and slurry residues that should not be originally formed on the substrate). As another method for distinguishing a scratch pattern (hereinafter referred to as a wrinkle pattern), there is a method using dark field illumination. This method will be briefly described.

  In a detection device including an illumination system that illuminates a substrate and an imaging system that forms an image of the illuminated substrate on an imaging device, the distribution of diffracted light on the pupil plane of the imaging system is a pattern (circuit) on the substrate. It is known that it is determined by the directionality of the pattern and the eyelid pattern) and the shape of the illumination light on the pupil plane of the illumination system. By applying this principle, the direction in which the circuit pattern extends is generally known, and accordingly the shape or attitude of the aperture stop in the illumination system and the shape or attitude of the aperture stop in the imaging system are set appropriately. By doing so, the circuit pattern and the heel pattern can be detected separately.

  More specifically, when applied to the surface condition inspection apparatus 30 described above, an aperture stop (for example, an annular aperture stop) for tilting illumination of the wafer W is disposed on the pupil plane of the detection illumination system 30a. In order to form a dark field illumination and image the surface of the wafer W onto the pre-alignment sensor 22c as an imaging device in the dark field method, an aperture stop (for example, a slit-shaped aperture stop) is also formed on the pupil plane of the imaging optical system 30b. Place. Then, by appropriately setting the shape or posture of the aperture stop of the imaging optical system 30b (for example, rotation about the optical axis in the longitudinal direction in the case of a slit-shaped aperture stop), the circuit pattern can be extended. Only a specific pattern (that is, a heel pattern) extending in a direction (oblique direction) different from the existing direction can be selectively imaged. In addition, when the direction of the circuit pattern and the direction of the eyelid pattern coincide with each other, the coincident portion of the eyelid pattern cannot be detected, but most of the eyelid patterns are formed with irregular directionality. Because it is normal, it does not seem to cause much problem.

  Contrary to this, it is configured so that only the circuit pattern is selectively imaged, and the result (circuit pattern, eyelid pattern of the image pattern) is taken without adopting such a dark field illumination method (that is, in the bright field). Alternatively, the wrinkle pattern may be separated by subtracting the imaging result of only the circuit pattern from (including both).

  As described above, according to the present embodiment, since a mark associated with a shot area having no defect or few defects is selected based on the surface state of the wafer W, a defect such as a scratch or slurry residue caused by CMP processing or the wafer The position information of the mark can be obtained with high accuracy even if the resist applied on W is uneven or other scratches are generated. Further, by obtaining the alignment coordinates of the shot area on the wafer W using the position information measurement result of the selected mark, the reticle R and each shot area can be aligned with high accuracy. The pattern that has already been formed and the pattern to be formed next can be superimposed with high accuracy. As a result, defects due to overlay defects are greatly reduced, so that high-performance, high-quality microdevices and the like can be manufactured with high yield and high efficiency.

  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 includes all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the above embodiment, the case where the surface state inspection device 30 includes a diffracted light detection device that performs macro inspection of the surface state of the wafer W using reflected light or diffracted light from the surface of the wafer W has been described as an example. . However, instead of the diffracted light detection device, scattered light that performs a macro inspection of the surface state of the wafer W by irradiating the surface of the wafer W with laser light and measuring the scattered light generated while scanning the laser light. A detection device or a differential interference device can be used. Here, the differential interference device is an interferometer that uses interference between a wavefront of light obtained from the surface of the wafer W and a wavefront obtained by shifting the wavefront in the lateral direction (in the XY plane), for example, Nomarski differential interference. It is an interferometer represented by a meter. Further, instead of providing these apparatuses alone, a plurality of apparatuses may be provided side by side to inspect the surface state of the wafer W using a plurality of apparatuses. By inspecting the surface state of the wafer W with a plurality of apparatuses, more information on the surface state of the wafer W can be obtained, and stable and highly accurate position measurement can be performed.

  In the above embodiment, the pre-alignment sensor 22c provided in the pre-alignment detection system RAS that performs pre-alignment of the wafer W held on the substrate table 14 (wafer holder 15) is also used as the imaging device of the surface state inspection apparatus. It was. However, the pre-alignment sensor provided in the pre-alignment detection system provided in the wafer loader can also be used as the surface condition inspection apparatus. Further, the alignment detection system AS shown in FIG. 1 may also be used as a surface state inspection apparatus. In such a configuration, the illumination light for detection is emitted from the surface state inspection apparatus, and the reflected light, diffracted light, and the like are received by the alignment detection system AS. Furthermore, the structure which provided the surface state inspection apparatus and the pre-alignment detection system separately may be sufficient. In the above embodiment, the alignment system AS is described as an example of a system that performs image processing. However, a system that scans a laser with respect to a wafer to obtain a mark position (LSA system or the like) may be used.

  Further, in the above embodiment, the case where the exposure apparatus is provided with the surface condition inspection apparatus has been described as an example. However, the exposure apparatus and the surface condition inspection apparatus are provided separately, and a LAN (Local) is provided between them. It is good also as a structure which connects with networks, such as Area Network, and transmits the inspection result of a surface state inspection apparatus to an exposure apparatus. For example, a resist coating apparatus (coater) that performs a resist coating process that is a process before the exposure process, a developing apparatus (developer) that performs a development process that is a process after the exposure process, and a CMP apparatus are connected to the exposure apparatus in an in-line manner. In the case of the above-described configuration, it is preferable to provide a surface condition inspection apparatus in the wafer transfer path. Furthermore, in the above embodiment, an example in which the position measuring device of the present invention is applied to an exposure apparatus has been described. However, the position measuring device of the present invention uses marks (position detection patterns) formed on a substrate or other objects. Applicable to general measuring devices.

  In the above embodiment, the case where the present invention is applied to a step-and-scan type exposure apparatus has been described as an example. However, the present invention is also applicable to a step-and-repeat type exposure apparatus (stepper). Can do. Further, as the illumination light IL, in addition to laser light emitted from an excimer laser or the like, a soft X-ray region generated from a laser plasma light source or SOR, for example, EUV (Extreme Ultra of wavelength 13.4 nm or 11.5 nm) Violet) light may be used. Furthermore, you may use charged particle beams, such as an electron beam or an ion beam. Infrared or visible single wavelength lasers oscillated from DFB semiconductor lasers or fiber lasers are amplified with, for example, a fiber amplifier doped with erbium (or both erbium and yttrium) and ultraviolet light is applied using a nonlinear optical crystal. You may use the harmonic which wavelength-converted to light. Note that a reflective mask is used in an exposure apparatus that uses EUV light, and a transmission mask (stencil mask, membrane mask) is used in an electron beam exposure apparatus or the like, so that a silicon wafer or the like is used as an original mask.

  Furthermore, not only an exposure apparatus for transferring a device pattern used for manufacturing a semiconductor element onto a wafer, but also an exposure apparatus for transferring a device pattern used for manufacturing a display including a liquid crystal display element onto a glass plate, a thin film magnetic head. The present invention can also be applied to an exposure apparatus for transferring a device pattern used for manufacturing a ceramic wafer onto an ceramic wafer, an exposure device used for manufacturing an imaging device (CCD or the like), a micromachine, a DNA chip, and the like.

  An illumination optical system and projection optical system composed of multiple lenses are incorporated into the exposure apparatus body for optical adjustment, and a reticle stage and substrate stage consisting of numerous mechanical parts are attached to the exposure apparatus body to connect wiring and piping. Further, the exposure apparatus of the present embodiment can be manufactured by further comprehensive adjustment (electrical adjustment, operation check, etc.). The exposure apparatus is preferably manufactured in a clean room in which the temperature, cleanliness, etc. are controlled.

  A semiconductor element includes a step of designing a function / performance of a device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and a reticle pattern by the exposure apparatus of the above-described embodiment. It is manufactured through an exposure transfer step, a device assembly step (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like.

1 is a view showing an outline of the overall configuration of an exposure apparatus according to an embodiment of the present invention. It is a top view which shows roughly the structure of the pre-alignment detection system periphery of the exposure apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the surface state inspection apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the principal part of the main control system with which the exposure apparatus which concerns on embodiment of this invention is provided. It is a figure which shows an example of the arrangement | sequence of the shot area | region set on a wafer. It is a figure for demonstrating an example of the process performed in a defect distribution calculation part. It is a flowchart which shows the outline of the exposure process operation | movement of the exposure apparatus which concerns on embodiment of this invention.

Explanation of symbols

1 ... exposure device 20 ... main control system 30 ... surface state inspecting apparatus 45 ... mark selection section 47 ... shot array computing unit AS ... alignment detection system ES i _... shot region _Mx i, My i _... mark R ... reticle _SA 1 -SA ₉ ... Sample shot W ... Wafer WST ... Wafer stage

Claims (12)

A position measurement device that measures position information of a plurality of position measurement patterns formed on a substrate on which a circuit pattern is to be formed,
Inspection means for inspecting a surface state over substantially the entire surface of the substrate on which the position measurement pattern is formed;
A selection unit that selects a predetermined number of position measurement patterns as a measurement target pattern from the plurality of position measurement patterns formed on the substrate based on the inspection result of the inspection unit;
And a measuring unit that measures position information of the measurement target pattern selected by the selecting unit. The inspection means performs an inspection for a predetermined uniformity on the surface of the substrate,
The selection unit selects, as the measurement target pattern, the position measurement pattern that exists in an area where the uniformity is evaluated to be a first level or more based on a result of the inspection unit. The position measuring device according to claim 1. On the substrate, a plurality of shot regions each including the position measurement pattern is formed,
The inspection means performs an inspection for a predetermined uniformity on the surface of the substrate,
The selection means selects the position measurement pattern associated with a shot area where the uniformity is equal to or higher than a second level among the plurality of shot areas as the measurement target pattern. The position measuring device described in 1.   The position measuring apparatus according to claim 2, wherein the inspection unit performs an inspection on at least one uniformity among a shape, a reflectance, and a spectral characteristic of the substrate surface.   The inspection means is a diffracted light detection device that detects diffracted light obtained by irradiating light on the surface of the substrate, a scattered light detection device that detects scattered light obtained by irradiating the surface of the substrate with laser light, The position measuring device according to claim 2, further comprising at least one of a differential interference device and a differential interference device. The inspection means includes
A detection illumination system that illuminates the substrate so as to be effective for a specific pattern extending in a direction different from a direction in which the circuit pattern extends among the patterns formed on the substrate;
Including an imaging optical system that forms an image on the surface of the substrate by a dark field method,
The position measuring device according to claim 2, wherein the image pickup device extracts and picks up an image of the specific pattern formed on the substrate. In an exposure apparatus comprising a substrate stage configured to be movable while holding the substrate, and exposing and transferring a mask pattern to each of the shot regions formed on the substrate,
Calculation means for performing statistical calculation using the position information of the measurement target pattern measured by the position measurement device according to any one of claims 1 to 6 to obtain position information of the plurality of shot areas;
An exposure apparatus comprising: an alignment device that controls the movement of the substrate stage on the basis of the position information obtained by the calculating means and aligns the mask and a shot area on the substrate; apparatus. A position measurement method for measuring position information of a plurality of position measurement patterns formed on a substrate on which a circuit pattern is to be formed,
An inspection step for inspecting a surface state over substantially the entire surface of the substrate on which the position measurement pattern is formed;
A selection step of selecting a predetermined number of position measurement patterns as a measurement target pattern from the plurality of position measurement patterns formed on the substrate based on the inspection result of the inspection step;
And a measurement step of measuring position information of the measurement target pattern selected in the selection step. In the inspection step, an inspection for a predetermined uniformity on the surface of the substrate is performed,
In the selection step, based on the result in the inspection step, the position measurement pattern existing in an area where the uniformity is evaluated to be equal to or higher than the first level is selected as the measurement target pattern. The position measuring method according to claim 8. On the substrate, a plurality of shot regions each including the position measurement pattern is formed,
In the inspection step, an inspection for a predetermined uniformity on the surface of the substrate is performed,
9. The position measuring pattern that accompanies a shot area in which the uniformity is equal to or higher than a second level among the plurality of shot areas is selected as the measurement target pattern in the selecting step. The position measuring method described in 1.   The position measurement method according to claim 9 or 10, wherein in the inspection step, an inspection is performed for at least one uniformity among the shape, reflectance, and spectral characteristics of the substrate surface. In an exposure method for exposing and transferring a mask pattern to each of shot areas formed on a substrate,
An alignment step of aligning the substrate and the mask based on position information of the measurement target pattern measured by the position measurement method according to any one of claims 8 to 11 is provided. Exposure method.

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