JP2013108779A - Surface inspection device, surface inspection method, and exposure system - Google Patents

Abstract

A surface inspection apparatus capable of obtaining a difference in scanning accuracy caused by a difference in scanning direction during exposure is provided.
An illumination system for illuminating a wafer having a pattern produced by exposure with illumination light, a light receiving system for detecting illumination light reflected by the pattern, an imaging device, and a wafer imaged by the imaging device. And an inspection unit 42 for obtaining a line width of the pattern from the diffraction image of the image and obtaining a difference in the line width of the pattern in the scanning direction.
[Selection] Figure 1

Description

The present invention relates to a surface inspection apparatus and a surface inspection method for inspecting the surface of a substrate exposed by an exposure apparatus. The present invention also relates to an exposure system including such a surface inspection apparatus and exposure apparatus.

A step-and-scan exposure apparatus moves a reticle stage (that is, a mask substrate on which a mask pattern is formed) relative to one shot while irradiating slit-shaped light through a mask pattern and a projection lens. By scanning only (= scanning), the semiconductor wafer is exposed for one shot. In this way, since the size of the exposure shot is determined by the relative scanning distance between the long side of the slit (light) and the reticle stage, the exposure shot can be enlarged.

JP 2007-304054 A

In such an exposure apparatus, the scanning direction may be reversed depending on the exposure shot for reasons such as shortening the working time. However, since the scanning accuracy is different between one scanning direction and the other scanning direction opposite to this, the pattern shape may change between exposure shots in different scanning directions. There has been a demand for a method for obtaining a difference in scanning accuracy.

The present invention has been made in view of such problems, and provides a surface inspection apparatus, a surface inspection method, and an exposure system capable of obtaining a difference in scanning accuracy caused by a difference in scanning direction during exposure. For the purpose.

In order to achieve such an object, the surface inspection apparatus according to the present invention includes an illumination unit that illuminates a substrate having a pattern produced by exposure with illumination light, a detection unit that detects illumination light reflected by the pattern, and An arithmetic unit that calculates information related to the exposure amount when the pattern is produced from the detection result, and an evaluation unit that calculates variations in the information related to the exposure amount.

An exposure system according to the present invention includes an exposure apparatus that scans and exposes a predetermined pattern on the surface of the substrate, and a surface inspection apparatus that performs surface inspection of the substrate that has been scanned and exposed to form the pattern on the surface. The surface inspection apparatus is a surface inspection apparatus according to the present invention, and outputs information obtained by the evaluation unit to the exposure apparatus, and the exposure apparatus is received by the evaluation unit input from the surface inspection apparatus. The setting of the exposure apparatus is corrected according to the obtained information.

In the surface inspection method according to the present invention, a substrate having a pattern produced by exposure is illuminated with illumination light, illumination light reflected by the pattern is detected, and the pattern is produced from the detection result. The information regarding the exposure amount is calculated, and the variation in the information regarding the exposure amount is obtained.

According to the present invention, a difference in scanning accuracy caused by a difference in scanning direction during exposure can be obtained.

It is a figure which shows the whole structure of a surface inspection apparatus. It is a figure which shows the state by which the polarizing filter was inserted on the optical path of a surface inspection apparatus. It is an external view of the surface of a semiconductor wafer. It is a perspective view explaining the uneven structure of a repeating pattern. It is a figure explaining the inclination state of the entrance plane of a linearly polarized light and the repeating direction of a repeating pattern. It is a flowchart which shows the method of calculating | requiring the difference of the line width of the pattern scanned and exposed in a forward direction, and the line width of the pattern scanned and exposed in a reverse direction. It is a figure which shows an example of a dose condition swing wafer. It is a figure which shows an example of a dose curve. It is a flowchart which shows the method of calculating | requiring the distribution of the line | wire width in the surface of a wafer. It is a schematic block diagram of an exposure system. It is a control block diagram of an exposure apparatus.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The surface inspection apparatus of this embodiment is shown in FIG. 1, and the surface of a semiconductor wafer 10 (hereinafter referred to as wafer 10), which is a substrate, is inspected by this apparatus. As shown in FIG. 1, the surface inspection apparatus 1 of the present embodiment includes a stage 5 that supports a substantially disk-shaped wafer 10, and the wafer 10 that is transferred by a transfer device (not shown) is placed on the stage 5. It is placed and fixed and held by vacuum suction. The stage 5 supports the wafer 10 so that the wafer 10 can rotate (rotate within the surface of the wafer 10) with the rotational axis of symmetry of the wafer 10 (the central axis of the stage 5) as the rotation axis. The orientation of the wafer due to this rotation will be referred to as the wafer orientation angle for convenience. The stage 5 can tilt (tilt) the wafer 10 about an axis passing through a support surface that supports the wafer 10, and can adjust the incident angle of illumination light.

The surface inspection apparatus 1 further includes an illumination system 20 that irradiates illumination light as parallel light on the entire surface of the wafer 10 supported by the stage 5, and reflected light from the entire surface of the wafer 10 when irradiated with illumination light. A light receiving system 30 that collects diffracted light and the like, an imaging device 35 that receives light collected by the light receiving system 30 and detects an image on the surface of the wafer 10, an image processing unit 40, an inspection unit 42, and a memory And a unit 45. The illumination system 20 includes an illumination unit 21 that emits illumination light, and an illumination-side concave mirror 25 that reflects the illumination light emitted from the illumination unit 21 toward the surface of the wafer 10. The illumination unit 21 includes a light source unit 22 such as a metal halide lamp or a mercury lamp, a light control unit 23 that extracts light having a predetermined wavelength from the light from the light source unit 22 and adjusts the intensity, and a light control unit 23 The light guide fiber 24 is configured to guide light to the illumination-side concave mirror 25 as illumination light.

Then, the light from the light source unit 22 passes through the light control unit 23 and has a predetermined wavelength (for example, 248 nm).
Illumination light having a predetermined intensity and having a predetermined wavelength is emitted from the light guide fiber 24 to the illumination side concave mirror 25, and the illumination light emitted from the light guide fiber 24 to the illumination side concave mirror 25 Since it is arranged on the focal plane of the illumination-side concave mirror 25, the illumination-side concave mirror 25 irradiates the surface of the wafer 10 held on the stage 5 as a parallel light beam. Wafer 10
The relationship between the incident angle and the exit angle of the illumination light with respect to can be adjusted by changing the mounting angle of the wafer 10 by tilting the stage 5.

The surface inspection apparatus 1 further includes a main control unit 50 and a hardware control unit 55 connected to the main control unit 50, and the main control unit 50 is connected to the light source unit 22 via the hardware control unit 55. And the light control unit 23 is controlled. The main control unit 50 also receives the image signal output from the imaging device 35 and sends it to the image processing unit 40. The image data processed by the image processing unit 40 is sent to the inspection unit 42 by the main control unit 50 and inspected. Inspection results and image data are stored in the main controller 5
0 is sent to the storage unit 45 for storage.

In addition, an illumination-side polarizing filter 26 is provided between the light guide fiber 24 and the illumination-side concave mirror 25 so as to be able to be inserted into and removed from the optical path, and as shown in FIG. An inspection using the diffracted light (hereinafter referred to as a diffraction inspection for the sake of convenience) is performed in the extracted state, and as shown in FIG. 2, polarized light (structural complex) is inserted with the illumination side polarization filter 26 inserted in the optical path. An inspection using a change in polarization state due to refraction (hereinafter referred to as a PER inspection for convenience) is performed (details of the illumination-side polarizing filter 26 will be described later).

Light emitted from the surface of the wafer 10 (diffracted light or reflected light) is collected by the light receiving system 30. The light receiving system 30 is mainly configured by a light receiving side concave mirror 31 disposed to face the stage 5, and emitted light (diffracted light or reflected light) collected by the light receiving side concave mirror 31 is an imaging device 35.
The image of the wafer 10 is formed.

In addition, a light receiving side polarizing filter 32 is provided between the light receiving side concave mirror 31 and the imaging device 35 so as to be inserted into and extracted from the optical path. As shown in FIG. 1, the light receiving side polarizing filter 32 is removed from the optical path. In this state, the diffraction inspection is performed, and as shown in FIG. 2, the PER inspection is performed with the light receiving side polarizing filter 32 inserted in the optical path (details of the light receiving side polarizing filter 32 will be described later). To do).

The imaging device 35 photoelectrically converts an image of the surface of the wafer 10 formed on the imaging surface to generate an image signal (digital image data), and outputs the image signal to the image processing unit 40 via the main control unit 50. To do. The image processing unit 40 generates a digital image of the wafer 10 based on the image signal of the wafer 10 input from the imaging device 35. The image data of the non-defective wafer is stored in the storage unit 45 in advance, and the inspection unit 42 receives the image data of the wafer 10 and the image data of the non-defective wafer from the main control unit 50 and compares them. Inspect for defects (abnormality). Then, the inspection result by the inspection unit 42 and the image of the wafer 10 at that time are output and displayed by an image display device (not shown). Further, the inspection unit 42 can obtain a dose amount during exposure by the exposure apparatus 101 using an image of the wafer (details will be described later).

By the way, the wafer 10 is projected and exposed with a predetermined mask pattern onto the uppermost resist film by the exposure device 101, developed by a developing device (not shown), and then a wafer cassette (not shown) by a transport device (not shown). Or it is conveyed on the stage 5 from a developing device. At this time, the wafer 10 is transferred onto the stage 5 in a state where the alignment is performed with reference to the pattern or outer edge (notch, orientation flat, etc.) of the wafer 10. Note that a plurality of chip regions 11 (shots) are formed on the surface of the wafer 10 as shown in FIG.
Are arranged vertically and horizontally (in the XY directions in FIG. 3), and in each chip region 11, a repeated pattern 12 such as a line pattern or a hole pattern is formed as a semiconductor pattern.

The exposure apparatus 101 is the above-described step-and-scan exposure apparatus,
For example, scanning exposure is performed in the + Y direction (from the lower side to the upper side in FIG. 3) for the odd-numbered shot row from the left end in the X direction, and for the even-numbered shot row from the left end in the X direction,
Scanning exposure is performed in the −Y direction (from the top to the bottom in FIG. 3). In other words, the exposure apparatus 101 performs scanning exposure on the wafer 10 in one scanning direction or the other scanning direction opposite to the scanning direction. The exposure apparatus 101 is electrically connected to the surface inspection apparatus 1 of the present embodiment via a cable or the like.

In order to perform diffraction inspection of the surface of the wafer 10 using the surface inspection apparatus 1 configured as described above, first, the illumination side polarizing filter 26 and the light receiving side polarizing filter 32 are removed from the optical path as shown in FIG. Then, the wafer 10 is transferred onto the stage 5 by a transfer device (not shown). In addition, the positional information of the pattern formed on the surface of the wafer 10 is acquired by an alignment mechanism (not shown) during the transfer, and the wafer 10 is placed at a predetermined position on the stage 5 in a predetermined direction. Can do.

Next, while rotating the stage 5 so that the illumination direction on the surface of the wafer 10 coincides with the pattern repetition direction (in the case of a line pattern, it is orthogonal to the line),
When the pitch of the pattern is P, the wavelength of the illumination light irradiated on the surface of the wafer 10 is λ, the incident angle of the illumination light is θ1, and the emission angle of the nth-order diffracted light is θ2, Setting is performed so as to satisfy the expression (1) (the stage 5 is tilted).

  P = n × λ / {sin (θ1) −sin (θ2)} (1)

Next, the illumination system 20 irradiates the surface of the wafer 10 with illumination light. When irradiating the illumination light onto the surface of the wafer 10 under such conditions, the light from the light source unit 22 in the illumination unit 21 passes through the dimming unit 23 and has a predetermined wavelength (for example, a wavelength of 248 nm). Intense illumination light is emitted from the light guide fiber 24 to the illumination-side concave mirror 25, and the illumination light reflected by the illumination-side concave mirror 25 is irradiated onto the surface of the wafer 10 as a parallel light beam. The diffracted light diffracted on the surface of the wafer 10 is collected by the light-receiving side concave mirror 31 and reaches the image pickup surface of the image pickup device 35.
(Diffraction image) is formed. A condition of diffracted light determined by a combination of a wafer azimuth angle, an illumination wavelength, an illumination angle, an emission angle, a diffraction order, and the like is referred to as a diffraction condition.

Therefore, the imaging device 35 photoelectrically converts an image of the surface of the wafer 10 formed on the imaging surface to generate an image signal, and outputs the image signal to the image processing unit 40 via the main control unit 50. The image processing unit 40 is based on the image signal of the wafer 10 input from the imaging device 35.
(Hereinafter, the digital image of the wafer 10 based on the diffracted light is referred to as a diffracted image for convenience). Further, when generating the diffraction image of the wafer 10, the image processing unit 40 sends the diffraction image to the inspection unit 42 via the main control unit 50, and the inspection unit 42 outputs the image data of the wafer 10 and the image data of the non-defective wafer. In comparison, the presence or absence of a defect (abnormality) on the surface of the wafer 10 is inspected. Then, the inspection result by the inspection unit 42 and the diffraction image of the wafer 10 at that time are output and displayed by an image display device (not shown).

Next, the case where the surface inspection apparatus 1 performs PER inspection on the surface of the wafer 10 will be described. As shown in FIG. 4, the repetitive pattern 12 is a resist pattern (line pattern) in which a plurality of line portions 2A are arranged at a constant pitch P along the short side direction (X direction).
Suppose that Further, a space 2B is provided between the adjacent line portions 2A. Further, the arrangement direction (X direction) of the line portions 2A will be referred to as a “repetitive direction of the repeated pattern 12”.

Here, the design value of the line width D _A of the line portion 2A in the repetitive pattern 12 is set to ½ of the pitch P. If repeated pattern 12 is formed as the design value, the line width D _B of the line width D _A and the space portion 2B of the line portion 2A are equal, the volume ratio of the line portion 2A and the space portion 2B is substantially 1: 1 In contrast, when the exposure focus at the time of forming the repeating pattern 12 deviates from a proper value, the pitch P does not change, with the line width D _A of the line portion 2A becomes different from a design value, of the space portion 2B It is different from the line width D _B , and the line part 2
The volume ratio between A and the space portion 2B deviates from about 1: 1.

The PER inspection performs an abnormality inspection of the repetitive pattern 12 by using a change in the volume ratio between the line portion 2A and the space portion 2B in the repetitive pattern 12 as described above.
In order to simplify the description, the ideal volume ratio (design value) is 1: 1. The change in the volume ratio is caused by deviation from the appropriate value of the exposure focus, and appears for each shot area of the wafer 10. The volume ratio can also be referred to as the area ratio of the cross-sectional shape.

In the PER inspection, as shown in FIG. 2, the illumination side polarizing filter 26 and the light receiving side polarizing filter 32 are inserted on the optical path. When performing the PER inspection, the stage 5 tilts the wafer 10 to an inclination angle at which the regular reflection light from the wafer 10 irradiated with the illumination light can be received by the light receiving system 30, and stops at a predetermined rotational position. Repeat pattern 1 on wafer 10
2, illumination light (linearly polarized light L) on the surface of the wafer 10, as shown in FIG.
) With respect to the vibration direction of 45). This is because the amount of light for inspection of the repeated pattern 12 is maximized. If the angle is 22.5 degrees or 67.5 degrees, the inspection sensitivity is increased. In addition, an angle is not restricted to these, It can set to an arbitrary angle direction.

The illumination-side polarizing filter 26 is disposed between the light guide fiber 24 and the illumination-side concave mirror 25, and its transmission axis is set to a predetermined direction, and the light from the illumination unit 21 is linearly set according to the transmission axis. Extract polarized light. At this time, since the exit portion of the light guide fiber 24 is disposed at the focal position of the illumination-side concave mirror 25, the illumination-side concave mirror 25 converts the light transmitted through the illumination-side polarizing filter 26 into a parallel light beam and is a wafer as a substrate. Illuminate 10. Thus, the light guide fiber 2
The light emitted from 4 becomes p-polarized linearly polarized light L (see FIG. 5) via the illumination-side polarizing filter 26 and the illumination-side concave mirror 25, and is irradiated on the entire surface of the wafer 10 as illumination light.

At this time, the traveling direction of the linearly polarized light L (the linearly polarized light L that reaches an arbitrary point on the surface of the wafer 10).
The direction of the principal ray of the light beam is substantially parallel to the optical axis.
Are equal to each other because of the parallel light flux. Further, since the linearly polarized light L incident on the wafer 10 is p-polarized light, as shown in FIG. 5, the repeating direction of the repeated pattern 12 is the incident surface of the linearly polarized light L (the traveling direction of the linearly polarized light L on the surface of the wafer 10). Is set to 45 degrees, the angle formed by the vibration direction of the linearly polarized light L on the surface of the wafer 10 and the repeating direction of the repeating pattern 12 is also set to 45 degrees. In other words, linearly polarized light L
In the state where the vibration direction of the linearly polarized light L on the surface of the wafer 10 is inclined 45 degrees with respect to the repeating direction of the repeating pattern 12, the incident light enters the repeating pattern 12 so as to cross the repeating pattern 12 obliquely.

The specularly reflected light reflected on the surface of the wafer 10 is collected by the light receiving side concave mirror 31 of the light receiving system 30 and reaches the image pickup surface of the image pickup device 35. At this time, the light is linearly reflected by the structural birefringence in the repetitive pattern 12. The polarization state of the polarized light L changes. The light receiving side polarizing filter 32 is disposed between the light receiving side concave mirror 31 and the imaging device 35, and the direction of the transmission axis of the light receiving side polarizing filter 32 is orthogonal to the transmission axis of the illumination side polarizing filter 26 described above. Is set (cross Nicole state). Therefore, the polarization component 32 (for example, s) of the specularly reflected light from the wafer 10 (repetitive pattern 12) is substantially perpendicular to the linearly polarized light L by the light receiving side polarizing filter 32.
Polarization component) can be passed and guided to the imaging device 35. As a result, the imaging device 35
On the imaging surface, a reflected image of the wafer 10 is formed by a polarized component whose vibration direction is substantially perpendicular to the linearly polarized light L of the regular reflected light from the wafer 10. The light receiving side polarizing filter 32 can be rotated about the optical axis, and the sensitivity is improved by adjusting the minor axis direction of the elliptically polarized regular reflected light and the transmission axis of the light receiving side polarizing filter 32. Can be made. Also in this case, the adjustment angle is several degrees, which is an orthogonal category.

In order to perform the PER inspection on the surface of the wafer 10 by the surface inspection apparatus 1, first, as shown in FIG. 10 is conveyed onto the stage 5. In addition, the positional information of the pattern formed on the surface of the wafer 10 is acquired by an alignment mechanism (not shown) during the transfer, and the wafer 10 is placed at a predetermined position on the stage 5 in a predetermined direction. Can do. At this time, the stage 5 tilts the wafer 10 at an inclination angle at which the regular reflection light from the wafer 10 irradiated with the illumination light can be received by the light receiving system 30, stops at a predetermined rotational position, and repeats on the wafer 10. The repeating direction of the pattern 12 is held so as to be inclined by 45 degrees with respect to the vibration direction of the illumination light (linearly polarized light L) on the surface of the wafer 10.

Next, the illumination system 20 irradiates the surface of the wafer 10 with illumination light. When irradiating the illumination light onto the surface of the wafer 10 under such conditions, the light emitted from the light guide fiber 24 of the illumination unit 21 passes through the illumination-side polarizing filter 26 and the illumination-side concave mirror 25 and is p-polarized linearly polarized light L. Thus, the entire surface of the wafer 10 is irradiated as illumination light. The specularly reflected light reflected from the surface of the wafer 10 is collected by the light-receiving side concave mirror 31 and reaches the image pickup surface of the image pickup device 35.
The image (reflected image) is formed.

At this time, the polarization state of the linearly polarized light L changes due to the structural birefringence in the repeating pattern 12, and the light receiving side polarizing filter 32 causes the linearly polarized light L and the vibration direction of the regular reflected light from the wafer 10 (repeating pattern 12). Can be guided to the imaging device 35 by passing a polarization component having a substantially right angle (ie, extracting a change in the polarization state of the linearly polarized light L). As a result, the imaging device 35
On the imaging surface, a reflected image of the wafer 10 is formed by a polarized light component whose vibration direction is substantially perpendicular to the linearly polarized light L of the regular reflected light from the wafer 10.

Therefore, the imaging device 35 photoelectrically converts an image (reflected image) of the surface of the wafer 10 formed on the imaging surface to generate an image signal (digital image data), and outputs the image signal via the main control unit 50. The image is output to the image processing unit 40. The image processing unit 40 receives the wafer 10 input from the imaging device 35.
Based on this image signal, a digital image of the wafer 10 (hereinafter, the digital image of the wafer 10 based on polarization is referred to as a polarization image for convenience) is generated. Further, when the polarized image of the wafer 10 is generated, the image processing unit 40 sends the polarized image to the inspection unit 42 via the main control unit 50, and the inspection unit 42 outputs the image data of the wafer 10 and the image data of the non-defective wafer. In comparison, the presence or absence of a defect (abnormality) on the surface of the wafer 10 is inspected. In addition, the signal intensity (
(Luminance value) is considered to indicate the highest signal intensity (luminance value). For example, if the signal intensity change (luminance change) compared to a non-defective wafer is greater than a predetermined threshold (allowable value), “abnormal” "If it is smaller than the threshold value, it is determined as" normal ". Then, the inspection result by the inspection unit 42 and the polarization image of the wafer 10 at that time are output and displayed by an image display device (not shown).

The signal intensity is signal intensity corresponding to light detected by the image sensor of the imaging device 35, such as diffraction efficiency, intensity ratio, energy ratio, and the like. In addition to the above-described diffraction inspection and PER inspection, inspection based on regular reflection light from the surface of the wafer 10 (hereinafter referred to as regular reflection inspection for convenience).
It is also possible to perform. When performing the regular reflection inspection, the image processing unit 40 generates a digital image based on the regular reflection light from the surface of the wafer 10 (hereinafter referred to as a regular reflection image for convenience), and generates the regular reflection image of the wafer 10. Based on this, the presence or absence of defects (abnormalities) on the surface of the wafer 10 is inspected.

Further, the inspection unit 42 can obtain the dose amount during exposure by the exposure apparatus 101 from the diffraction image of the wafer 10 or the like. The dose is an energy amount when forming a pattern. Furthermore, by making a template of the relationship between the line width of the repetitive pattern 12 and the dose amount, the inspection unit 42 can calculate the line width of the repetitive pattern 12 from the obtained dose amount. Therefore, the inspection unit 42 determines the exposure apparatus 1 from the diffraction image of the wafer 10.
01, the line width of the repeated pattern 12 scanned and exposed in one scanning direction (hereinafter referred to as the forward direction for convenience) and the other scanning direction opposite to this (hereinafter referred to as the reverse direction for convenience).
Thus, the difference from the line width of the repeated pattern 12 to be scanned and exposed can be obtained.

A method for obtaining the difference between the line width of the repeated pattern 12 scanned and exposed in the forward direction and the line width of the repeated pattern 12 scanned and exposed in the opposite direction will be described with reference to the flowchart shown in FIG. First, a wafer on which a repeated pattern is formed by changing the dose amount of the exposure apparatus 101 is manufactured (step ST101). At this time, exposure and development are performed while varying the dose amount for each exposure shot. Hereinafter, such a wafer is referred to as a dose condition swing wafer 10a (see FIG. 7). Here, the doses are made different for the purpose of offsetting the influence of differences in resist conditions that occur between the center side and the outer periphery side of the wafer.

As shown in FIG. 7, the dose condition swing wafer 10a of the present embodiment has a dose amount of 1.5 m.
8 steps in increments of J (10.0 mJ, 11.5 mJ, 13.0 mJ, 14.5 mJ, 16.0
mJ, 17.5 mJ, 19.0 mJ, 20.5 mJ). Each shot in FIG. 7 shows a dose offset stage shaken in 1.5 mJ increments. When the stage is the same and the scanning direction (scanning direction) is the reverse direction, “′” is attached. Yes. For example, in the shot represented by number 6, exposure performed with the same dose amount is performed by two movements in the reticle movement Y + direction / center side, two shots / reticle movement Y + direction / outer periphery side, and two shots / reticle movement Y− direction / center side. Eight positions are set as two shots in the shot / reticle movement Y-direction / outer peripheral side. Further, for example, in the shot represented by the number 1, the exposure with the same dose amount is performed with the conditionally adjusted wafer 10a.
Reciprocal movement Y + direction / peripheral side 4 shot reticle movement Y−
Eight locations are set like 4 shots on the direction / outer peripheral side. In this embodiment, the dose-conditioning wafer 10a is made with a total of 64 shots of 8 dose offsets and 8 shots for each dose amount. The exposure amount required for pattern exposure is 5 depending on the pattern.
mJ to about 40 mJ, and the swing width when making a dosing condition wafer is 0.5 mJ to 2
. It is desirable to set it to 0 mJ.

Note that a plurality of dose-conditioning wafers may be manufactured. In this case, it is preferable that the shot arrangement for each dose amount of each conditionally adjusted wafer is set so as to cancel the influence due to conditions other than the dose amount.

When the dose-conditioning wafer 10a is manufactured, the dose-conditioning wafer 10a is transferred onto the stage 5 in the same manner as in the diffraction inspection (step ST102). Next, as in the case of the diffraction inspection, the illumination system 20 irradiates the illumination light onto the surface of the dose-conditioning wafer 10a, and the imaging device 35 photoelectrically converts the image of the dose-conditioning wafer 10a to generate an image signal. Then, the image signal is output to the image processing unit 40 via the main control unit 50 (step ST103). At this time,
With respect to the dose-conditioning wafer 10a, the diffraction conditions are obtained using the pitch information of the exposed pattern or the diffraction condition search, and the same setting as in the diffraction inspection is performed so that diffracted light is obtained. In the diffraction condition search, the tilt angle of the stage 5 is changed stepwise in an angle range other than specular reflection to acquire images at the respective tilt angles, and the image is brightened, that is, the tilt angle at which diffracted light is obtained is obtained. Refers to the function. In addition, the azimuth angle (attitude of the exposed pattern with respect to the illumination direction of the illumination light) of the dose condition swing wafer 10a matches the illumination direction with the repeated direction of the exposed pattern (in the case of a line-and-space pattern, the direction orthogonal to the line). Are arranged to be.

Next, the image processing unit 40 generates a diffraction image (digital image) of the dose condition swing wafer 10 a based on the image signal of the dose condition swing wafer 10 a input from the imaging device 35. Further, when the image processing unit 40 generates a diffraction image of the dose condition swing wafer 10a, the image processing unit 40 sends the diffraction image to the inspection unit 42 via the main control unit 50, and the inspection unit 42 has a dose amount and a scanning direction (scan direction). The signal intensity (luminance) is averaged pixel by pixel (pixels corresponding to each shot) for each shot (step ST104). Note that a portion determined to be a defect by the diffraction inspection is excluded from the above-described averaging target.

At this time, the inspection unit 42 encloses a plurality of setting areas (small rectangles) set in the shot shown in FIG. 7 for all shots obtained by averaging (different dose amounts from each other) whose scanning direction is the positive direction. The average value of the signal intensity in area A) (hereinafter referred to as average luminance for convenience) is obtained. Further, at this time, the inspection unit 42 obtains the average brightness in each of the plurality of setting areas A for all the shots obtained by the averaging (different in dose amount) whose scanning directions are opposite to each other. Since the dose amount of the exposure apparatus 101 is changed for each shot in the dose condition changing wafer 10a, the dose amount can be obtained from the position of the shot, and the same dose in each shot exposed with a different dose amount can be obtained. In the position setting area A, the average luminance changes according to the dose.

Therefore, the inspection unit 42 corresponds to the average luminance in the setting region A at the same position in each shot whose scanning direction is the positive direction (different in dose amount) for each setting region A for which the average luminance is obtained. A graph showing the relationship with the dose amount (hereinafter referred to as a dose curve) is obtained. Further, the inspection unit 42 corresponds to the average luminance in the setting region A at the same position in each shot in which the scanning direction is opposite (different in dose amount) for each setting region A for which the average luminance is obtained. A graph showing the relationship with the dose amount, that is, a dose curve is obtained (step ST105).
. Here, an example of a dose curve is shown in FIG. Note that a dose curve obtained in this step in a shot in which the scanning direction is forward is referred to as a forward reference dose curve, and a dose curve in a shot in which the scanning direction is reversed is referred to as a backward reference dose curve.

Next, the inspection unit 42 obtains approximate curves obtained by approximating the forward reference dose curve and the reverse reference dose curve with functions for each set region A (step ST106). Note that it is preferable to use a quartic function (quaternary expression) as the function of the approximate curve. The quartic function is the following (
2) It is expressed as shown below.

y = ax ⁴ + bx ³ + cx ² + dx + e (2)

Here, x is the dose amount, y is the signal intensity (average luminance), and a, b, c, d, e
Is a coefficient. The optimum coefficient a for approximating the dose curve using the least square method or the like,
By obtaining b, c, d, and e, an approximate function of equation (2) is obtained.

Next, the inspection unit 42 performs a dose amount that is a luminance (signal intensity) corresponding to the design value in the approximate curve of the forward reference dose curve, and a luminance (signal intensity) that corresponds to the design value in the approximate curve of the reverse direction reference dose curve. Each dose amount is determined (step ST107). At this time, a dose amount that provides luminance (signal intensity) corresponding to the design value is obtained for each setting region A (
Step ST108). In this way, it is possible to obtain a dose distribution in a shot whose scanning direction is the forward direction and a dose distribution in a shot whose scanning direction is the reverse direction. Note that the luminance (signal intensity) corresponding to the design value in the approximate curve of the dose curve is obtained in advance using a pattern whose line width matches the design value.

As described above, the relationship between the line width and the dose amount of the repetitive pattern 12 is templated in advance as a data map or the like and stored in the storage unit 45. The inspection unit 42 includes the storage unit 4
Using the data map stored in 5, the line width of the repeated pattern 12 that is scanned and exposed in the positive direction is obtained for each set region A from the dose amount in the shot whose scanning direction is the positive direction.
Also, the inspection unit 42 uses the data map stored in the storage unit 45 to set the line width of the repeated pattern 12 scanned and exposed in the reverse direction from the dose amount in the shot whose scan direction is the reverse direction. Each time (step ST109). At this time, since the line width is obtained for each set region A, the distribution of the line width in the shot whose scanning direction is the forward direction and the distribution of the line width in the shot whose scanning direction is the reverse direction can be obtained.

Next, the inspection unit 42 obtains, for each setting region A, the difference between the line width of the repeated pattern 12 that is scanned and exposed in the forward direction and the line width of the repeated pattern 12 that is scanned and exposed in the reverse direction (step ST110). . At this time, since the difference in line width is obtained for each setting area A, the distribution of the difference in line width in the shot due to the difference in the scanning direction can be obtained. The line width difference due to the difference in the scanning direction thus obtained is converted into, for example, a parameter suitable for the exposure apparatus 101, and is output from the inspection unit 42 to the exposure apparatus 101 via the signal output unit 60 for exposure. Device 10
1 is reflected in the exposure by 1. At this time, for example, the line width distribution in the shot in which the scanning direction is the forward direction and the line width distribution in the shot in which the scanning direction is the reverse direction are matched to the one having the smaller line width variation (variance value). Adjustment of the exposure apparatus 101 is performed. in this way,
The inspection unit 42 has a calculation / evaluation function for obtaining a difference in dose (exposure amount) and line width.

When the scanning accuracy of the exposure apparatus 101 differs depending on the scanning direction, it is considered that the synchronous drive precision of the reticle stage 120 and the stage apparatus 150 (see FIG. 10) of the exposure apparatus 101 is low, and in particular, scanning exposure (scanning) is started. In this case, since the acceleration increases, a difference in scanning accuracy due to a difference in scanning direction is likely to occur. If a difference in scanning accuracy due to a difference in scanning direction occurs, the focus does not change, but a difference occurs in the dose amount per shot. Therefore, the line width of the repetitive pattern 12 exposed to the exposure apparatus 101 also differs in the scanning direction. Will cause a difference.

Thus, according to the surface inspection apparatus 1 of the present embodiment, the line width of the repeated pattern 12 that is scanned and exposed in one scanning direction and the repeated pattern 12 that is scanned and exposed in the other scanning direction.
By calculating the difference from the line width (that is, the line width variation due to the difference in the scanning direction),
It becomes possible to obtain a difference in scanning accuracy caused by a difference in scanning direction in the exposure apparatus 101. Also, by feeding back the obtained line width difference to the exposure apparatus 101, the line width of the pattern exposed and developed on the entire surface of the wafer can be made as designed.

Further, if an image by diffracted light generated from the surface of the wafer is taken, it is difficult to be affected by fluctuations in the film thickness of the resist film or the like, so the dose during exposure (that is, the line width of the repetitive pattern 12) is set. It is possible to measure with high accuracy. In particular, the wavelength of the illumination light is 248n.
Wavelengths in the deep ultraviolet region such as m and 313 nm (j line) are desirable. Further, if the dose amount at the time of exposure is obtained using a plurality of diffraction conditions, for example, further improvement in accuracy can be expected by averaging for each diffraction condition. Further, by selecting an optimal diffraction condition for each of various target patterns, highly sensitive and highly accurate measurement can be performed.

Note that the inspection unit 42 can also obtain a variation state of the dose with respect to the entire surface of the wafer 10 by using images of a plurality of wafers that are exposed and developed while changing the dose amount of the exposure apparatus 101 for each wafer. As described above, the inspection unit 42 repeats the pattern 1 from the dose amount.
Since the line width of 2 can be calculated, the distribution of the line width on the surface of the wafer 10 can be obtained from the variation state of the dose with respect to the entire surface of the wafer 10. Therefore, the wafer 10
A method for obtaining the distribution of the line width on the surface will be described with reference to the flowchart shown in FIG. First, a plurality of wafers (exposure amounts are 10.0 mJ, 11.5 mJ, 13.0 mJ, and 14.5 mJ) that are exposed and developed while changing the dose amount of the exposure apparatus 101 for each wafer.
, 16.0 mJ, 17.5 mJ, 19.0 mJ, 20.5 mJ) images (step ST201). At this time, wafer illumination, imaging, and the like are performed in the same manner as in the case of diffraction inspection (conditions for obtaining a predetermined signal intensity from a pattern exposed and developed with an optimal dose amount and an optimal focus condition). Here, a plurality of wafers having different dose amounts are referred to as measurement wafers.

Next, the inspection unit 42 sets the signal intensity for each measurement wafer in which the dose amount of the exposure apparatus 101 is changed from the acquired wafer image, and the average value of the setting regions formed by pixel units (or a small number of pixels). , The same applies hereinafter) (step ST202). Whether it is a pixel unit or a setting area formed by a small number of pixels, it is referred to as a setting area A for convenience, and its signal intensity (or average value) is referred to as average luminance. Next, for each shot setting area A, the inspection unit 42 shows the relationship between the average luminance in the setting area A at the same position in each wafer (with different focus offset amounts) and the corresponding dose amount. Graph, ie dose curve (
In order to distinguish it from the reference dose curve obtained from the dose condition wafer 10a, the sample dose curve is hereinafter referred to as appropriate (step ST203). Note that it is preferable to use a quartic function as the approximate curve when approximating the sample dose curve (step ST).
204). At this time, since the dose offset of the exposure apparatus 101 is changed for each measurement wafer, the dose amount can be obtained from the type of measurement wafer, and in the set area A at the same position in the shot, the dose amount can be determined. As a result, the average luminance changes.

Next, using the obtained sample dose curve, the inspection unit 42 obtains a dose shift amount corresponding to the sample dose curve of each setting area A for each setting area A of all shots (step ST205). Specifically, fitting (so-called fitting) is performed so that the correlation between the sample dose curve of each setting area A stored in a memory (not shown) and the forward reference dose curve or the backward reference dose curve of the corresponding setting area A is the best. Pattern matching). At this time, the amount of movement of the dose amount in the increasing / decreasing direction is the dose shift amount of the setting area A. Note that the forward reference dose curve or the reverse reference dose curve is selected according to the scanning direction of each shot.

In this way, since the distribution of the dose shift amount on the wafer surface can be obtained, the variation state of the dose with respect to the entire wafer surface can be obtained. Then, using the data map stored in the storage unit 45, the inspection unit 42 obtains the line width of the repeated pattern 12 for each setting region A from the amount of dose shift in each setting region A (step ST2).
06). At this time, since the line width is obtained for each setting region A, the distribution of the line width on the surface of the wafer can be obtained. That is, the line width distribution in the shot whose scanning direction is the forward direction and the line width distribution in the shot whose scanning direction is the reverse direction can be respectively obtained on the wafer surface. It is possible to obtain a variation in line width due to a difference in scanning direction on the surface. At this time, for example, the difference in line width between a certain shot whose scanning direction is the forward direction and each shot whose scanning direction is the reverse direction can be obtained.
Further, for example, the difference in line width between a shot in which the scanning direction is the forward direction and a shot in which the scanning direction adjacent thereto is in the reverse direction can be obtained. Further, the inspection unit 42 converts the line width variation (line width difference) due to the difference in the scanning direction into, for example, a parameter suitable for the exposure apparatus 101, and outputs the parameter to the exposure apparatus 101 via the signal output unit 60. It is also possible.

Using a measurement wafer whose scanning direction is all in the forward direction and a measurement wafer whose scanning direction is all in the reverse direction, the distribution of the line width on the surface of each wafer is obtained, and the line width over the entire surface of the wafer The difference may be obtained.

Further, the repetitive pattern 1 is obtained from the line width of the repetitive pattern 12 obtained by the inspection unit 42.
If the presence / absence of abnormality in 2 is inspected, the reference of the inspection becomes clear because the line width of the repetitive pattern 12 is used as a reference, and the presence / absence of abnormality of the repetitive pattern 12 can be accurately inspected. At this time, for example, the inspection unit 42 can determine that the line width of the obtained repeated pattern 12 is normal if the line width is within a predetermined range, and can determine that the line pattern is out of the predetermined range.

In the above-described embodiment, the repeated pattern 1 that is scanned and exposed in one scanning direction.
Although the difference between the line width of 2 and the line width of the repeated pattern 12 scanned and exposed in the other scanning direction is obtained, the present invention is not limited to this. For example, the difference in the scanning direction between the dose amount (exposure amount) for the shot exposed in the one scanning direction and the dose amount for the shot exposed in the other scanning direction may be obtained. Even in this way, it is possible to obtain a difference in scanning accuracy caused by a difference in scanning direction in the exposure apparatus 101. Further, by feeding back the obtained dose amount difference to the exposure apparatus 101, the line width of the pattern exposed and developed on the entire surface of the wafer can be made as designed. In this case, a variation in dose amount among a distribution of dose amount for shots exposed in scanning direction in one scanning direction and a distribution of dose amount for shots exposed in scanning direction in the other scanning direction (
The exposure apparatus 101 is adjusted so as to match the smaller (dispersion value).

Also, not only scanning accuracy, but when performing split exposure like mix and match,
The dose amount (exposure amount) of each divided region can be obtained. Therefore, when the dose amount is deviated from the appropriate amount, the dose amount of each divided region can be adjusted.

In the above-described embodiment, it is preferable to use a quartic equation as the approximate curve equation of the dose curve. However, linear approximation may be performed depending on the shape of the graph.

In the above-described embodiment, the technique for obtaining the line width difference in the scanning direction by a technique similar to the diffraction inspection has been described. However, the line width difference in the scanning direction can also be obtained by a technique similar to the PER inspection (polarization inspection). Can be sought.

For example, in step ST103 of the flowchart shown in FIG. 6, the illumination system 20 irradiates the surface of the dose condition wafer 10a with linearly polarized light L as illumination light, and the imaging device 35 photoelectrically converts the reflected image of the dose condition wafer 10a. The image signal may be generated and the image signal may be output to the image processing unit 40 via the main control unit 50. Accordingly, the inspection unit 42 can obtain a dose curve due to polarization using the polarization image of the dose condition swing wafer 10a. The inspection unit 42 uses this dose curve to obtain a dose amount at which the luminance (signal intensity) of polarized light becomes a value corresponding to the design value, and calculates the line width of the repeated pattern 12 from the obtained dose amount. For example, as in the case of diffracted light, the repeated pattern 12 that is scanned and exposed in the positive direction.
And the line width of the repeated pattern 12 scanned and exposed in the opposite direction can be obtained.

In the above-described embodiment, the line width difference in the scanning direction obtained by the inspection unit 42 is calculated as follows.
It can be output from the inspection unit 42 to the exposure apparatus 101 via the signal output unit 60 and fed back to the setting of the exposure apparatus 101. Therefore, an exposure system provided with the above-described surface inspection apparatus 1 will be described with reference to FIGS. In this exposure system 100, a predetermined mask pattern (repetitive pattern) is formed on the surface of a wafer 10 coated with a resist.
An exposure apparatus 101 for projecting exposure, and a surface inspection apparatus 1 for inspecting a wafer 10 having a repeated pattern 12 formed on the surface through an exposure process by an exposure apparatus 101 and a development process by a development apparatus (not shown). It is configured with.

As shown in FIG. 10, the exposure apparatus 101 includes an illumination system 110, a reticle stage 120, a projection unit 130, a local immersion apparatus 140, a stage apparatus 150, and the main controller 2.
00 (see FIG. 11). In the following description, the directions of arrows X, Y, and Z shown in FIG. 10 will be described as the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively.

Although not shown in detail, the illumination system 110 includes a light source, an illuminance equalizing optical system including an optical integrator, and an illumination optical system including a reticle blind. The reticle is defined by the reticle blind. The slit-shaped illumination area on R is illuminated with illumination light (exposure light) with substantially uniform illuminance. As illumination light, for example, ArF excimer laser light (wavelength 193 nm) is used.

On reticle stage 120, reticle (photomask) R on which a predetermined pattern (for example, line pattern) is formed on its pattern surface (lower surface in FIG. 10) is fixed and held by, for example, vacuum suction. The reticle stage 120 can be moved in the XY plane by a reticle stage driving device 121 (see FIG. 11) including a linear motor, for example, and at a predetermined scanning speed in the scanning direction (here, the Y-axis direction). It is configured to be movable.

Position information of the reticle stage 120 in the XY plane (including rotation information about the rotation direction around the Z axis) is reflected on the first reflecting mirror 123 having a reflecting surface orthogonal to the Y axis provided on the reticle stage 120 and the X axis. Detection is performed by the reticle interferometer 125 via a second reflecting mirror (not shown) having an orthogonal reflecting surface. The position information detected by the reticle interferometer 125 is sent to the main controller 200, and the main controller 200 moves the position (and moving speed) of the reticle stage 120 via the reticle stage driving device 121 based on the position information. To control.

The projection unit 130 is disposed below the reticle stage 120 and includes a lens barrel 131 and a projection optical system 135 held in the lens barrel 131. The projection optical system 135 is
It has a plurality of optical elements (lens elements) arranged along the optical axis AX of illumination light, is telecentric on both sides, and has a predetermined projection magnification (for example, 1/4, 1/5, 1/8, etc.)
It is comprised so that it may have. For this reason, when the illumination area on the reticle R is illuminated by the illumination light emitted from the illumination system 110, the illumination light transmitted through the reticle R arranged so that the object plane and the pattern plane of the projection optical system 135 substantially coincide with each other. Thus, a reduced image of the pattern of the reticle R in the illumination area via the projection optical system 135 is conjugated to the exposure area on the wafer 10 arranged on the image plane side of the projection optical system 135 (the illumination area on the reticle R). A region). And
By synchronous driving of the reticle stage 120 and the stage apparatus 150 that holds the wafer 10, the reticle R is moved in the scanning direction (Y-axis direction) with respect to the illumination area, and the wafer 10 is moved in the scanning direction (Y By moving in the axial direction, scanning exposure of one shot area on the wafer 10 is performed, and the pattern (mask pattern) of the reticle R is transferred to the shot area.

The exposure apparatus 101 is provided with a local liquid immersion apparatus 140 for performing immersion type exposure. As shown in FIGS. 10 and 11, the local liquid immersion device 140 includes a liquid supply device 141,
The liquid recovery apparatus 142, the liquid supply pipe 143A, the liquid recovery pipe 143B, and the nozzle unit 145 are configured. The nozzle unit 145 holds the projection unit 130 so as to surround the periphery of the lower end portion of the lens barrel 131 that holds the optical element on the most image plane side (wafer side) constituting the projection optical system 135, here the tip lens 136. It is supported by a frame member (not shown) (a frame member constituting the exposure apparatus 101). Further, as shown in FIG. 10, the nozzle unit 145 is set so that its lower end surface is substantially flush with the lower end surface of the front lens 136.

Although not shown in detail, the liquid supply device 141 includes a tank that stores liquid, a pressurizing pump, a temperature control device, and a valve that controls the flow rate of the liquid. It is connected to the nozzle unit 145 via a pipe 143A. The liquid recovery device 142
Although not shown in detail, the tank includes a tank for storing the recovered liquid, a suction pump, and a valve for controlling the flow rate of the liquid, and is connected to the nozzle unit 145 via the liquid recovery pipe 143B. Has been.

As shown in FIG. 11, the main control device 200 controls the operation of the liquid supply device 141 to supply liquid (for example, pure water) between the tip lens 136 and the wafer 10 via the liquid supply tube 143A. At the same time, the operation of the liquid recovery device 142 is controlled to recover the liquid from between the front lens 136 and the wafer 10 via the liquid recovery tube 143B. At this time, the main controller 200 determines that the amount of liquid supplied and the amount of liquid recovered are always equal.
41 and the liquid recovery apparatus 142 are controlled. Therefore, a certain amount of liquid is always exchanged and held between the front lens 136 and the wafer 10, thereby forming an immersion area (immersion space). Thus, in the exposure apparatus 101, the wafer 10 is exposed by irradiating the wafer 10 with illumination light through the liquid forming the liquid immersion area.

The stage device 150 is a wafer stage 151 disposed below the projection unit 130.
And a stage driving device 155 (see FIG. 11) for driving the wafer stage 151. Wafer stage 151 has a clearance of about several μm by an air slider (not shown) and is supported to float above base member 105, and is configured to hold wafer 10 on the upper surface of wafer stage 151 by vacuum suction. . Wafer stage 151 is then moved to base member 105 by a motor that constitutes stage drive device 155.
It is possible to move in the XY plane along the upper surface.

Position information of the wafer stage 151 in the XY plane is detected by an encoder device 156 (see FIG. 11). The position information detected by the encoder device 156 is sent to the main control device 200, and the main control device 200 determines the stage driving device 15 based on the position information.
5 is used to control the position (and moving speed) of the wafer stage 151.

In the exposure apparatus 101 configured as described above, when the illumination area on the reticle R is illuminated by the illumination light emitted from the illumination system 110, the object plane and the pattern plane of the projection optical system 135 are substantially aligned. The reduced image of the pattern of the reticle R in the illumination area is supported on the wafer stage 151 and arranged on the image plane side of the projection optical system 135 through the projection optical system 135 by the illumination light transmitted through the reticle R. Is formed in an exposed region on the wafer 10 (region conjugate to the illumination region on the reticle R). Then, by synchronous driving of the reticle stage 120 and the wafer stage 151 that supports the wafer 10, the reticle R is moved in the scanning direction (Y-axis direction) with respect to the illumination area, and the wafer 10 is moved in the scanning direction with respect to the exposure area. By moving in the (Y-axis direction), scanning exposure of one shot area on the wafer 10 is performed, and the pattern of the reticle R is transferred to the shot area.

At this time, for example, in the odd-numbered shot row from the end in the X-axis direction, the reticle R is moved in the −Y-axis direction with respect to the illumination area, and the wafer 10 is moved in the −Y-axis direction with respect to the exposure area. By moving, for each shot area in the odd-numbered column from the end +
Scanning exposure in the Y-axis direction is performed. On the other hand, in the even-numbered shot row from the end in the X-axis direction, the reticle R is moved in the + Y-axis direction with respect to the illumination area, and the wafer 10 is moved in the + Y-axis direction with respect to the exposure area. Scanning exposure in the -Y-axis direction is performed on each shot area in the even-numbered columns from. That is, the scanning exposure is performed on the wafer 10 in one scanning direction or the other scanning direction opposite to the scanning direction.

When the exposure process by the exposure apparatus 101 is performed in this manner, a developing device (not shown)
Through the development process and the like, the surface inspection of the wafer 10 on which the repeated pattern 12 is formed is performed by the surface inspection apparatus 1 according to the above-described embodiment. Before performing the exposure process,
As described above, the surface inspection apparatus 1 obtains a difference in line width in the scanning direction, and connects the connection cable (
The line width difference data in the scanning direction is output to the exposure apparatus 101 via a not shown).
Then, the correction processing unit 210 provided in the main controller 200 of the exposure apparatus 101 does not cause a difference in the line width depending on the scanning direction based on the difference in the line width depending on the scanning direction input from the surface inspection apparatus 1. In addition, various setting parameters of the exposure apparatus 101 are corrected.

Thereby, according to the exposure system 100 of the present embodiment, scanning is performed in order to correct the setting of the exposure apparatus 101 according to the difference in line width in the scanning direction input from the surface inspection apparatus 1 according to the above-described embodiment. The exposure apparatus 101 can be set more appropriately without the pattern shape changing between exposure shots in different directions.

1 Surface inspection device 5 Stage 10 Wafer (10a dose condition wafer)
20 Illumination system (illumination part)
30 light receiving system (detection unit) 35 imaging device (detection unit)
40 Image processing unit 42 Inspection unit (calculation unit, evaluation unit)
DESCRIPTION OF SYMBOLS 100 Exposure system 101 Exposure apparatus

Claims (7)

An illumination unit that illuminates a substrate having a pattern produced by exposure with illumination light;
A detection unit for detecting illumination light reflected by the pattern;
A calculation unit for calculating information on an exposure amount when the pattern is produced from the detection result;
A surface inspection apparatus comprising: an evaluation unit that obtains variation in information regarding the exposure amount. The surface inspection apparatus according to claim 1, wherein the pattern is formed by exposure during scanning of the substrate, and the evaluation unit obtains variation in the scanning. On the substrate, a pattern exposed while scanning the substrate in one side and a pattern exposed while scanning the substrate in the other side opposite to the one are prepared,
The surface inspection apparatus according to claim 1, wherein the evaluation unit obtains a difference between the one scan and the other scan. An exposure apparatus that scans and exposes a predetermined pattern on the surface of the substrate, and a surface inspection apparatus that performs surface inspection of the substrate that is scanned and exposed to form the pattern on the surface,
The surface inspection apparatus is the surface inspection apparatus according to any one of claims 1 to 3,
Outputting the information obtained by the evaluation unit to the exposure apparatus;
The exposure apparatus corrects the setting of the exposure apparatus according to information obtained by the evaluation unit input from the surface inspection apparatus. Illuminate a substrate having a pattern produced by exposure with illumination light;
Detecting the illumination light reflected by the pattern;
Calculate information on the amount of exposure when the pattern is produced from the result of the detection,
A surface inspection method characterized by obtaining variation in information relating to the exposure amount. 6. The surface inspection method according to claim 5, wherein the pattern is formed by exposure during scanning of the substrate, and variation in the scanning is obtained. On the substrate, a pattern exposed while scanning the substrate in one side and a pattern exposed while scanning the substrate in the other side opposite to the one are prepared,
The difference between the one scan and the other scan is obtained.
The surface inspection method described in 1.

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