JP2015099898A - Evaluation device, evaluation method, exposure system and method for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and highly accurately evaluate at least one of a film thickness condition and an exposure condition in forming a pattern using a substrate having the pattern formed thereon.SOLUTION: An evaluation device 1 includes: an illumination system 20 for illuminating polarized light on a surface of a wafer 10 having a repetitive pattern 12 formed thereon; an imaging apparatus 35 and an image processing section 40 for receiving light reflected from the surface by the illumination of the illumination system 20 to detect stokes parameters of the light; and an operation section 50 for evaluating a film thickness condition and an exposure condition in forming the repetitive pattern 12 on the basis of a film thickness condition and an exposure condition in forming the repetitive pattern 12 on a conditioned wafer 10a, data representing relationships with stokes parameters S1, S2, and stokes parameters S1, S2 of light reflected from the surface.

Description

  The present invention relates to an evaluation technique for evaluating a processing condition of a pattern formed on a substrate, an exposure technique using the evaluation technique, and a device manufacturing technique using the evaluation technique.

  An exposure apparatus such as a scanning stepper or a stepper used in a lithography process for manufacturing a device (semiconductor device or the like) illuminates a mask on which a predetermined pattern is formed, and projects an image of the mask pattern on a projection optical system. Then, the substrate is exposed by projecting onto a substrate (for example, a semiconductor wafer (hereinafter simply referred to as a wafer)) coated with a photosensitive resin (so-called resist).

  Further, an oxide film may be formed in advance on the surface of the substrate exposed by the exposure apparatus (the back surface of the photosensitive resin) by a thermal oxidation method or a CVD (Chemical Vapor Deposition) method. Further, a conductive film may be formed on the surface of the substrate by a vacuum deposition method, a sputtering method, a CVD method, or the like. In this case, a pattern of an oxide film or a conductive film is formed by a process such as etching after development of the photosensitive resin.

  In an exposure apparatus, it is necessary to manage a plurality of exposure conditions such as an exposure amount (so-called dose), a focus position (a defocus amount of a substrate to be exposed with respect to an image plane of a projection optical system), and an exposure wavelength with high accuracy. . For this purpose, it is necessary to expose the substrate with an exposure apparatus and evaluate the actual exposure conditions of the exposure apparatus with high accuracy using a pattern or the like formed on the exposed substrate.

  For example, as a conventional method for evaluating the focus position of an exposure apparatus, a mask evaluation pattern is illuminated with illumination light whose chief ray is inclined, and the pattern image is displayed on a plurality of substrates while changing the height of the substrate on the stage. A method is known in which each shot is sequentially exposed, a lateral shift amount of a resist pattern obtained by development after exposure is measured, and a focus position at the time of exposure of each shot is evaluated from this measurement result (for example, Patent Documents) 1).

US Patent Application Publication No. 2002/0100012

  In order to further increase the yield of devices manufactured using the substrate exposed by the exposure apparatus, the film thickness of the photosensitive resin, oxide film, or conductive film formed on the substrate is within a desired range. For this purpose, it is necessary to evaluate the film thickness condition with high accuracy.

In order to further increase the yield of the device, it is preferable that the exposure conditions in the exposure apparatus are within a desired range. For this purpose, it is necessary to evaluate the exposure conditions with high accuracy.
Furthermore, in order to manufacture the device with high throughput (productivity), it is preferable to efficiently evaluate the film thickness condition or the exposure condition.

  The aspect of the present invention has been made in view of such problems, and efficiently using at least one of the film thickness condition and the exposure condition when the pattern is formed using the substrate on which the pattern is formed, The purpose is to evaluate with high accuracy.

  According to the first aspect of the present invention, an illumination unit that illuminates polarized light on the surface of a test substrate having a test pattern formed on the surface, and light reflected from the surface by illumination of the illumination unit is received. And data indicating the relationship between the detector for detecting the conditions for defining the polarization state of the light, the film thickness conditions and the exposure conditions for forming the predetermined pattern, and the conditions for defining the polarization state, and the surface thereof. An arithmetic unit that evaluates at least one of a film thickness condition when the test pattern is formed and an exposure condition when the test pattern is formed based on a condition that defines a polarization state of the reflected light; Are provided.

According to a second aspect, there is provided a coating apparatus that applies a photosensitive film to the surface of a substrate, an exposure apparatus that exposes a pattern on the surface of the substrate, and an evaluation apparatus according to an aspect of the present invention. An exposure system that adjusts at least one of the coating apparatus and the exposure apparatus according to the result is provided.
According to the third aspect, the polarized light is illuminated on the surface of the test substrate having the test pattern formed on the surface, and the light reflected from the surface by the illumination of the polarized light is received, and the light Detecting the conditions that define the polarization state of the film, data indicating the relationship between the film thickness condition and the exposure condition when forming the predetermined pattern, and the conditions that define the polarization state, and the polarization of the light reflected from the surface An evaluation method comprising: evaluating at least one of a film thickness condition when the test pattern is formed and an exposure condition when the test pattern is formed based on a condition defining a state Provided.

  According to the fourth aspect, the photosensitive film is applied on the surface of the substrate, the pattern is exposed on the surface of the substrate, and the film thickness when the pattern is formed using the evaluation method of the aspect of the present invention. A semiconductor device manufacturing method that evaluates at least one of conditions and exposure conditions, and corrects at least one of the film thickness condition of the photosensitive film and the exposure condition of the pattern according to the evaluation result of the evaluation method Is provided.

  According to the aspect of the present invention, using a substrate on which a pattern is formed, at least one of a film thickness condition and an exposure condition when the pattern is formed can be evaluated efficiently and with high accuracy.

(A) is a figure which shows the whole structure of the evaluation apparatus which concerns on an example of embodiment, (b) is a top view which shows a wafer. (A) is an enlarged perspective view showing the concavo-convex structure of the repeating pattern, and (b) is a diagram showing the relationship between the incident surface of the linearly polarized light and the periodic direction (or repeating direction) of the repeating pattern. (A) is a figure which shows an example of the relationship between exposure amount and the change of a polarization state, (b) is a figure which shows an example of the relationship between a focus position and the change of a polarization state. It is a flowchart which shows an example of the method (condition extraction) which calculates | requires apparatus conditions (evaluation conditions). It is a flowchart which shows an example of the evaluation method of film thickness conditions and exposure conditions. (A) is a plan view showing an example of a shot arrangement of a conditioned wafer, (b) is an enlarged view showing one shot, and (c) is an enlarged view showing an example of an arrangement of a plurality of setting areas in the shot. . (A) And (b) is a figure which shows an example of the relationship between the film thickness and exposure conditions on the 1st apparatus conditions, and Stokes parameters S1 and S2, respectively, (c) is an exposure amount and a Stokes parameter It is a figure which shows an example of a relationship. (A) And (b) is a figure which shows an example of the relationship between the film thickness and exposure conditions on the 2nd apparatus conditions, and Stokes parameters S1 and S2, respectively, (c) is a film thickness and a Stokes parameter It is a figure which shows an example of a relationship. (A) and (b) are diagrams showing an example of the relationship between the film thickness and exposure conditions under the third apparatus condition and the Stokes parameters S1 and S2, respectively. (C) is the relationship between the focus position and the Stokes parameter. It is a figure which shows an example of a relationship. (A) is a figure which shows an example of the template for film pass / fail determination. (A) is a figure which shows an example of the change of the Stokes parameter on the Poincare sphere when the film thickness and / or the exposure conditions are changed, and (b) is the Stokes on the Poincare sphere under different apparatus conditions. The figure which shows an example of the change of a parameter, (c) is a figure which shows an example of the template for a pass / fail determination on a Poincare sphere. It is a flowchart which shows a semiconductor device manufacturing method.

  Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to FIGS. 1 (a) to 9 (c). FIG. 1A shows an evaluation apparatus 1 according to this embodiment. In FIG. 1A, the evaluation apparatus 1 includes a stage 5 that supports a substantially disk-shaped wafer (semiconductor wafer) 10, and the wafer 10 transferred by a transfer system (not shown) Is mounted and fixed and held, for example, by vacuum suction. Hereinafter, on a plane parallel to the upper surface of the stage 5 in an untilted state, the X axis is taken in a direction parallel to the paper surface of FIG. 1A, and the Y axis is taken in a direction perpendicular to the paper surface of FIG. In the following description, the Z axis is taken in the direction perpendicular to the plane including the X axis and the Y axis. In FIG. 1A, the stage 5 has a first drive unit (not shown) that controls a rotation angle φ1 with a normal CA at the center of the upper surface of the stage 5 as a rotation axis, and the center of the upper surface of the stage 5, for example. As described above, a tilt angle φ2 (tilt of the surface of the wafer 10) is an inclination angle with an axis TA (tilt axis) perpendicular to the paper surface of FIG. 1A (parallel to the Y axis of FIG. 1A) as a rotation axis. It is supported by a base member (not shown) via a second drive unit (not shown) that controls the angle.

  The evaluation apparatus 1 further includes an illumination system 20 that irradiates the illumination light ILI as parallel light onto the surface of the wafer 10 (hereinafter referred to as a wafer surface) supported by the stage 5 and having a predetermined repetitive pattern formed on the surface. A light receiving system 30 that collects light (regular reflection light, diffracted light, etc.) emitted from the wafer surface upon receiving the illumination light ILI, and an image of the wafer surface that receives the light collected by the light receiving system 30 An imaging device 35 that processes the image signal output from the imaging device 35 and obtains a condition that defines the polarization state of the light that forms the image, and information about the condition is described later. As described above, at least one of film thickness conditions when a resist as a photosensitive resin layer is applied to the wafer surface with a coater / developer and exposure conditions when the resist is exposed through a mask by an exposure apparatus Includes a calculation unit 50 for evaluation of conditions, the. The imaging device 35 includes an imaging optical system 35a that forms an image on the wafer surface and a two-dimensional imaging device 35b such as a CCD or a CMOS. The imaging device 35b collects images of the entire surface of the wafer 10 as an example. And picks up an image and outputs an image signal. The film thickness conditions were not only the thickness when the resist was applied, but also the thickness of the oxide film, the conductive film, etc., the height of the pattern formed through the exposure and development processes, and the etching process. Including the height of the pattern. Note that the height of the pattern formed through the exposure and development processes and the height of the pattern formed through the etching process can be referred to as the pattern height condition. Note that when the test pattern is formed only in a partial region of the entire surface of the wafer 10, the imaging element 35b may capture only an image of the partial region.

  On the wafer surface, exposure areas having a mask pattern as a unit are formed at predetermined intervals by exposure of an exposure apparatus. Hereinafter, this exposure area is referred to as a shot. Some shots have only one mask pattern exposed, while others have a plurality of mask patterns connected and exposed. In the shot, an area that finally becomes a single device through the exposure process is hereinafter referred to as a chip. There may be a plurality of chips in a shot, or one shot may become one chip.

  Based on the image signal of the wafer 10 input from the imaging device 35, the image processing unit 40 performs digital image of the wafer 10 (signal intensity for each pixel, signal intensity averaged for each shot, or for each area smaller than the shot. (Averaged signal intensity and the like) information is generated, and Stokes parameters described later as conditions for defining the polarization state obtained based on this information are output to the arithmetic unit 50. Note that the image processing unit 40 is configured to simply output digital image information (information on signal intensity distribution for each pixel, etc.) to the calculation unit 50. The calculation unit 50 includes an inspection unit 60 including calculation units 60a, 60b, and 60c that processes information such as Stokes parameters, a control unit 80 that controls operations of the image processing unit 40 and the inspection unit 60, and an image. A storage unit 85 for storing information on the data, and an evaluation result (described later) of the obtained film thickness and exposure conditions are output to a control unit (not shown) of the coater / developer 95 and a control unit (not shown) of the exposure apparatus 100, respectively. And a signal output unit 90. In addition, the image processing unit 40 and the calculation unit 50 may be configured as a whole, and the image processing unit 40, the inspection unit 60, the control unit 80, and the like may be functions on the software of the computer.

  In this embodiment, the evaluation apparatus 1 is formed on the surface of the wafer 10 by a pattern forming thin film (an oxide film formed by a thermal oxidation method or a CVD method, or a vacuum deposition method, a sputtering method, a CVD method, or the like). A thin film forming apparatus (not shown) such as a thermal oxidation apparatus, a plasma CVD apparatus, a vacuum evaporation apparatus, or a sputtering apparatus, or a resist is applied to the surface of the wafer 10, and the exposed resist is developed. The coater / developer 95, the exposure apparatus 100 that exposes the surface of the wafer 10 coated with the resist through the mask on which the pattern is formed and the projection optical system, and the wafer 10 are etched using the developed resist as a mask. Etching apparatus (not shown), and host computer (not shown) for comprehensively controlling the operation of these apparatuses Include, the exposure system or device manufacturing system for manufacturing semiconductor devices is constituted.

  In the evaluation apparatus 1, the illumination system 20 includes an illumination unit 21 that emits illumination light, and an illumination-side concave mirror 25 that reflects illumination light emitted from the illumination unit 21 toward the wafer surface as parallel light. The illumination unit 21 emits light having a predetermined wavelength (for example, different wavelengths λ1, λ2, λ3, etc.) out of light from the light source unit 22 according to a command from the control unit 80 and a light source unit 22 such as a metal halide lamp or a mercury lamp. A light control unit 23 for selecting and adjusting the intensity, a light guide fiber 24 for emitting light selected by the light control unit 23 and adjusted in intensity from a predetermined emission surface to the illumination side concave mirror 25, and a light guide fiber 24 And a polarizer 26 (illumination side polarization filter) that linearly polarizes the illumination light emitted from the exit surface. The polarizer 26 is, for example, a polarizing plate having a transmission axis. The polarizer 26 is rotatable about an axis that passes through the center of the surface 26 a on which illumination light emitted from the exit surface of the light guide fiber 24 is incident and is orthogonal to the surface 26 a. That is, the direction of the transmission axis of the polarizer 26 can be set to an arbitrary direction, and the vibration direction of the linearly polarized light converted by the polarizer 26 can be set to an arbitrary direction. The rotation angle of the polarizer 26 (the direction of the transmission axis of the polarizer 26) is controlled by a drive unit (not shown) based on a command from the control unit 80. As an example, the wavelength λ1 is 248 nm, λ2 is 265 nm, and λ3 is 313 nm. In this case, since the exit surface of the light guide fiber 24 is disposed at the focal point of the illumination-side concave mirror 25, the illumination light ILI reflected by the illumination-side concave mirror 25 is irradiated as a parallel light beam onto the wafer surface. The incident angle θ1 of the illumination light with respect to the wafer 10 (the angle formed between the principal ray of the illumination light and the normal of the wafer surface) is emitted from the light guide fiber 24 via a drive mechanism (not shown) according to a command from the control unit 80. Adjustment is possible by controlling the position of the unit and the position and angle of the illumination-side concave mirror 25. In the present embodiment, the normal line of the wafer surface is parallel to the normal line CA of the stage 5.

  In the present embodiment, the position and angle of the illumination-side concave mirror 25 are controlled by tilting the illumination-side concave mirror 25 about the tilt axis TA of the stage 5, and thereby the illumination light incident on the wafer 10 (wafer surface). The incident angle θ1 is adjusted. In the present embodiment, when the incident angle θ1 is changed during normal inspection, the position of the exit portion of the light guide fiber 24 and the position and angle of the illumination-side concave mirror 25 are controlled, and the regular reflection light ILR from the wafer 10 is controlled. That is, the stage 5 so that light having an emission angle θ2 from the wafer surface (an angle formed between the principal ray of light reflected from the wafer surface and the normal of the wafer surface) that is the same as the incident angle θ1 enters the light receiving system 30. The tilt angle φ2 is controlled.

Thus, in a state where the polarizer 26 is inserted on the optical path, an inspection using polarized light (change in polarization state due to structural birefringence) (hereinafter also referred to as a polarization inspection for convenience) is performed.
The light receiving system 30 includes a light receiving side concave mirror 31 disposed facing the stage 5 (wafer 10), a quarter wavelength plate 33 disposed on the optical path of light reflected by the light receiving side concave mirror 31, and 1 / And an analyzer 32 (light receiving side polarization filter) disposed in the optical path of the light that has passed through the four-wavelength plate 33, and the front focal point of the imaging optical system 35 a of the imaging device 35 is disposed at the focal point of the light receiving concave mirror 31. ing. Therefore, the parallel light emitted from the wafer surface is condensed by the light receiving side concave mirror 31 and the imaging optical system 35a of the imaging device 35, and an image of the wafer surface is formed on the imaging surface of the imaging element 35b. The analyzer 32 is also a polarizing plate having a transmission axis, for example, like the polarizer 26. The analyzer 32 passes through the center of the surface 32a on which the light reflected by the light-receiving side concave mirror 31 is incident, and is rotatable about an axis orthogonal to the surface 32a. That is, the direction of the transmission axis of the analyzer 32 can be set to an arbitrary direction, and the vibration direction of the linearly polarized light converted by the analyzer 32 can be set to an arbitrary direction. The rotation angle of the analyzer 32 (the direction of the transmission axis of the polarizing plate) is controlled by a drive unit (not shown) based on a command from the control unit 80. As an example, the transmission axis of the analyzer 32 can be set in a direction (crossed Nicols) orthogonal to the transmission axis of the polarizer 26. The quarter-wave plate 33 passes through the center of the surface 33a on which the light reflected by the light-receiving side concave mirror 31 is incident, and is rotatable about an axis orthogonal to the surface 33a. The rotation angle of the quarter-wave plate 33 can be controlled by a drive unit (not shown) based on a command from the control unit 80. For example, by processing a plurality of images of the wafer surface obtained while rotating the quarter-wave plate 33, a Stokes parameter, which is a condition that defines the polarization state of the reflected light from the wafer 10 as described later, is used as a pixel. It can be obtained every time.

  Further, an oxide film is formed on the surface of the wafer 10 by a thermal oxidation apparatus or a plasma CVD apparatus according to a process, or a conductive film is formed by a vacuum evaporation apparatus, a sputtering apparatus, a CVD apparatus, or the like. A resist is applied by a coater / developer 95. Then, a predetermined pattern is projected and exposed to the uppermost resist through a mask by the exposure apparatus 100, and after development of the resist by the coater / developer 95, the wafer 10 is transferred onto the stage 5 of the evaluation apparatus 1. Here, a repetitive pattern 12 (see FIG. 1B) is formed on the upper surface of the wafer 10 transferred onto the stage 5 through exposure and development processes by the exposure apparatus 100 and the coater / developer 95.

  Then, the wafer 10 is transferred by a not-shown alignment mechanism in the course of conveyance, a pattern in a shot of the wafer 10, a mark on the wafer surface (for example, a search alignment mark), or an outer edge (notch, orientation flat, uneven mark on the back surface, etc.) Is transferred onto the stage 5 in a state where alignment is performed with reference to. In the present embodiment, as shown in FIG. 1B, a plurality of shots 11 are arranged on the wafer surface at predetermined intervals in two orthogonal directions (X direction and Y direction). As an example of a circuit pattern of a semiconductor device, a line pattern having a longitudinal direction as a Y direction is formed. This line pattern is a repeated pattern 12 in which irregularities are repeated in the X direction of the line. In FIGS. 1B and 1C, in the plane parallel to the surfaces of the wafers 10 and 10a, the two axes orthogonal to each other are the X axis and the Y axis, and the axis is perpendicular to the plane including the X axis and the Y axis. Is the Z axis. The repeating pattern 12 may be a pattern made of a dielectric material such as a resist pattern, or may be a pattern made of a metal. The repeating pattern is not limited to a line pattern, and may be a hole pattern, for example. Note that a single shot 11 often includes a plurality of chip areas, but in FIG. 1B, it is assumed that there is one chip area in one shot for simplicity.

In the present embodiment, as an example, the inspection unit 60 processes the image of the wafer surface as will be described later, and the film thickness condition of the resist applied to the wafer 10 by the coater / developer 95 and the exposure condition of the exposure apparatus 100. The case of evaluating (inspecting) is described.
Here, the film thickness condition includes an average value of the film thickness of the resist applied to the wafer 10, distribution in the wafer surface, variation, and the like. The exposure conditions include the exposure amount (so-called dose of exposure energy and the like) of the exposure apparatus 100 that has exposed the wafer 10, the focus position (the position of the image plane of the mask pattern in the optical axis direction of the projection optical system in the exposure apparatus, the exposure) Projection optical system and wafer for exposure by the immersion method, exposure wavelength (center wavelength and / or half-value width), exposure wavelength (center wavelength and / or half-value width) in the optical axis direction of the projection optical system with respect to the target wafer The temperature of the liquid between and the like. The evaluation results of the film thickness condition and the exposure condition are output to a control unit (not shown) in the coater / developer 95 and a control unit (not shown) in the exposure apparatus 100 as an example, and according to the evaluation result, In order to correct the film thickness condition (for example, correction of offset, variation, etc.), the coater / developer 95 includes, for example, various resist film forming conditions on the wafer surface, such as resist coating amount, heat treatment temperature and time, and the like. Conditions can be adjusted. Similarly, according to the evaluation result, the exposure apparatus 100 can correct the exposure conditions (for example, correction of offset, variation, etc.).

  An example of a method for performing evaluation or inspection based on a change in the polarization state of reflected light from the wafer surface using the evaluation apparatus 1 configured as described above will be described. In this case, the repetitive pattern 12 on the wafer surface in FIG. 1B is along the arrangement direction (here, the X direction) in which the plurality of line portions 2A are short directions, as shown in FIG. 2A. It is assumed that the resist patterns (line patterns) are arranged at a constant pitch (period) P with the space portion 2B interposed therebetween. The arrangement direction (X direction) of the line portions 2A is also referred to as a periodic direction (or a repeating direction) of the repeating pattern 12.

  Here, as an example, the design value (that is, the ideal value) of the ratio between the line width da of the line portion 2A and the height T of the line portion 2A is set to 1: 1. When the repeated pattern 12 is formed as designed, the shape of the XZ cross section of the line portion 2A is a square. On the other hand, if the resist film thickness, the focus position in the exposure apparatus 100, and the exposure amount when forming the repeated pattern 12 deviate from the appropriate values, the line width da of the line portion 2A and the height T of the line portion 2A. And the ratio of the XZ cross section of the line portion 2A is not square (in other words, the volume of the line portion 2A deviates from the design value).

  The evaluation of this embodiment is based on the change in the polarization state of the reflected light from the wafer surface (so-called repetition on the wafer surface) accompanying the change in the XZ sectional shape (volume) of the line portion 2A in the repetitive pattern 12 as described above. The resist film thickness condition and the exposure condition are evaluated using the change in the polarization state of reflected light due to structural birefringence in the pattern 12. Note that the change in the XZ sectional shape (volume) of the line portion 2 </ b> A of the repetitive pattern 12 appears for each shot 11 of the wafer 10 and for each of a plurality of regions in the shot 11.

  In order to evaluate the resist film thickness condition and the exposure condition from the change in the state of the reflected light from the wafer surface using the evaluation apparatus 1 of the present embodiment, the control unit 80 stores recipe information stored in the storage unit 85. (Device conditions or evaluation conditions, procedures, etc.) are read and the following processing is performed. In the present embodiment, Stokes parameters S0, S1, S2, and S3 defined by the following equation of light regularly reflected on the wafer surface are measured as conditions for defining the polarization state. Note that the axes orthogonal to each other in the plane perpendicular to the optical axis of the light are the x-axis and the y-axis, and the intensity of the linearly polarized light component (transversely polarized light) in the x direction is Ix, and the linearly polarized light component in the y direction (vertically polarized light) The intensity of the linearly polarized light component in the direction inclined by 45 ° with respect to the x axis (45 ° polarized light) (Ipx) and the intensity of the linearly polarized light component in the direction inclined by 135 ° (−45 °) with respect to the x axis (135 The intensity of (polarized light) is Imx, the intensity of the clockwise circularly polarized component is Ir, and the intensity of the counterclockwise circularly polarized component is Il.

S0 = total intensity of luminous flux (1A)
S1 (intensity difference between horizontally polarized light and vertically polarized light) = Ix−Iy (1B)
S2 (intensity difference between 45 ° polarized light and 135 ° polarized light) = Ipx−Imx (1C)
S3 (intensity difference between clockwise and counterclockwise circularly polarized light components) = Ir−Il (1D)
The Stokes parameter S0 is the square root of the square sum of the other three Stokes parameters S1 to S3, and is normalized so that the Stokes parameter S0 is 1 below. In this case, the values of the other Stokes parameters S1 to S3 are in the range of −1 to +1. The Stokes parameters (S1, S2, S3) are, for example, (0, -1, 0) for perfect 135 ° polarization and (0, 0, 1) for perfect clockwise circular polarization.

  First, the wafer 10 on which the repetitive pattern 12 to be inspected is formed on the stage 5 through the steps of resist application in the coater / developer 95, resist exposure in the exposure apparatus 100, and resist development in the coater / developer 95. It is placed in a predetermined direction at a predetermined position. The tilt angle φ2 of the stage 5 is set so that the regular reflection light ILR from the wafer 10 can be received by the light receiving system 30, that is, the light received by the light receiving system 30 with respect to the incident angle θ1 of the incident illumination light ILI with respect to the wafer surface. The reflection angle (light reception angle or emission angle) is set to be equal. Further, as an example, the angle of the polarizer 26 is set so that the illumination light ILI incident on the wafer surface becomes P-polarized light linearly polarized in a direction parallel to the incident surface. As an example, the rotation angle of the stage 5 is such that the periodic direction of the repetitive pattern 12 on the wafer surface is the illumination light on the wafer surface as shown in FIG. 2B (in FIG. It is set to be inclined at 45 ° with respect to the vibration direction of light L). This is because the signal intensity of the reflected light from the repeated pattern 12 is maximized. When the angle between the periodic direction and the vibration direction is 22.5 ° or 67.5 °, the detection sensitivity (change in detection signal or parameter with respect to change in film thickness or exposure conditions) increases. The angle may be changed. The angle is not limited to these and can be set to an arbitrary angle.

  At this time, since the illumination light incident on the wafer surface is P-polarized light, as shown in FIG. 2B, the periodic direction of the repeated pattern 12 is the incident surface of the light L (the traveling direction of the light L on the wafer surface). On the other hand, when the angle is set to 45 °, the angle formed by the vibration direction of the light L on the wafer surface and the periodic direction of the repeated pattern 12 is also set to 45 °. In other words, the linearly polarized light L is incident so as to obliquely cross the repetitive pattern 12 in a state where the vibration direction of the light L on the wafer surface is inclined by 45 ° with respect to the periodic direction of the repetitive pattern 12.

  The specularly reflected light ILR of the parallel light reflected by the wafer surface 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 via the quarter wavelength plate 33 and the analyzer 32. At this time, due to structural birefringence in the repetitive pattern 12, the polarization state of the specularly reflected light ILR changes to, for example, elliptically polarized light with respect to the linearly polarized light of incident light. As an example, the orientation of the transmission axis of the analyzer 32 is set to be orthogonal to the transmission axis of the polarizer 26 (in a crossed Nicols state). Therefore, of the specularly reflected light whose polarization state has changed from the wafer 10 (repetitive pattern 12), the analyzer 32 extracts a polarization component whose vibration direction is substantially perpendicular to the light L and guides it to the imaging device 35. As a result, an image of the wafer surface is formed on the imaging surface of the imaging device 35 by the polarization component extracted by the analyzer 32. It is also possible to take an image of the wafer surface by shifting the angle of the analyzer 32 by a predetermined angle from the crossed Nicols state.

  In the present embodiment, as an example, the Stokes parameters S0 to S3 indicating the polarization state of the reflected light from the wafer surface are obtained by the rotational phase shifter method. In this case, the rotation angle θ of the quarter-wave plate 33 is set to a plurality of angles (for example, at least four different angles) θi (i = 1, 2,...) Step by step, and the wafer surface at each rotation angle. The image is picked up by the image pickup device 35b, and the obtained image signal is supplied to the image processing unit 40. Information about the rotation angle of the quarter-wave plate 33 is also supplied to the image processing unit 40. At this time, when the Stokes parameter S0 (total intensity of each pixel) is Fourier-transformed with respect to the rotation angle θ of the quarter-wave plate 33, the 0th-order coefficient is a0 / 2, the sin2θ coefficient is b2, and the cos4θ coefficient is a4. When the coefficient of sin 4θ is b4, the Stokes parameters S1, S2, and S3 correspond to the coefficients a4, b4, and b2, respectively. Therefore, the image processing unit 40 can obtain the Stokes parameters S0 to S3.

The rotational phase shifter method is described as, for example, “Method with Rotating λ / 4 Plate” in the document “Tatsuo Tsuruta: Applied Optics II (Applied Physics), p.233 (Baifukan, 1990)”. Yes. A detailed method for calculating the Stokes parameter is also described in Japanese Patent Application Laid-Open No. 2010-249627 filed by the present applicant.
The image processing unit 40 outputs the obtained Stokes parameter information for each pixel of the imaging device 35 to the inspection unit 60. The inspection unit 60 evaluates the film thickness condition in the coater / developer 95 and the exposure condition in the exposure apparatus 100 used when the repetitive pattern 12 of the wafer 10 is formed using the information. As described above, when the Stokes parameter for each pixel of the image on the wafer surface is obtained, the incident angle θ1 of the illumination light ILI with respect to the wafer surface in the evaluation apparatus 1 (or the emission angle of the exit light from the wafer surface), the illumination light ILI. Wavelength λ (λ1 to λ3, etc.), rotation angle of analyzer 32 (direction of transmission axis), rotation angle of polarizer 26 (direction of transmission axis), rotation angle of stage 5 (direction of wafer 10), etc. The combination is called one device condition. The apparatus conditions can also be called evaluation conditions. When the evaluation based on the change in the polarization state is performed as described above, the apparatus condition can also be called a polarization condition. A plurality of device conditions are included in the recipe information of the evaluation device 1 stored in the storage unit 85. In this embodiment, an apparatus condition suitable for evaluating the film thickness condition and the exposure condition of the pattern formed on the wafer is selected from the plurality of apparatus conditions. As the apparatus conditions, at least one of the wavelength λ, the incident angle θ1, and the angle of the analyzer 32 may be used, or any other condition that can be adjusted in the evaluation apparatus 1 may be used. The wavelength λ of the illumination light ILI, the incident angle θ1 of the illumination light ILI with respect to the wafer surface, and the rotation angle (azimuth of the transmission axis) of the polarizer 26 are examples of illumination conditions, and the exit angle of the exit light from the wafer surface (Reception angle by the light receiving system 30) and the rotation angle of the analyzer 32 (the direction of the transmission axis) are examples of detection conditions of the detector, and the rotation angle of the stage 5 (the direction of the wafer 10) and the tilt angle φ2 of the stage 5 (Tilt angle of wafer surface) is an example of the attitude condition of the stage.

  In the following description, as an example, the exposure conditions to be evaluated by the exposure apparatus 100 are defined as the first exposure condition and the second exposure condition, the first exposure condition is the exposure amount, and the second exposure condition is the focus position. At this time, since the line width of the pattern changes (the cross-sectional shape changes) when the exposure amount changes, when a linearly polarized light beam enters the wafer surface, the exposure of the pattern is performed as shown in FIG. If the exposure amount at the time changes from D1 (low state with respect to the optimum value) to D8 (high state with respect to the optimum value) through D5 (optimum value, so-called best dose amount Dbe), the wafer qualitatively. The polarization state of the reflected light from the surface changes both the direction (tilt) of the major axis of elliptically polarized light and the ellipticity. Further, since the major axis direction of elliptically polarized light corresponds to the Stokes parameter S2 and the ellipticity corresponds to the Stokes parameters S1 and S3, the Stokes parameters S1, S2, and S3 of the reflected light change when the exposure amount changes.

  On the other hand, since the cross-sectional shape of the pattern changes when the focus position changes, as shown in FIG. 3B, when the linearly polarized light beam enters the wafer surface, the focus position during exposure of the pattern is F1 ( When the state changes from F4 (optimum value, so-called best focus position Zbe) to F8 (highest state relative to the optimum value) through F4 (low state with respect to the optimum value), qualitatively, the polarization of the reflected light from the wafer surface The state is that the major axis direction (tilt) of elliptically polarized light is substantially the same, and only the ellipticity tends to change. For this reason, when the focus position changes, the Stokes parameters S1 and S3 of the reflected light change relatively large, and the rate of change of the Stokes parameter S2 tends to be relatively small. By utilizing the fact that the Stokes parameters that change depending on the exposure conditions differ in this way, it becomes possible to inspect individual exposure conditions from the measured values of the Stokes parameters.

Further, when the thickness of the resist formed on the wafer 10 changes, the height T of the repeated pattern 12 changes and the polarization state of the reflected light from the wafer surface changes, so that the resist thickness is determined from the measured Stokes parameter value. Can be measured. As an example, when the incident angle of the illumination light with respect to the wafer surface is large, the change in the polarization state of the reflected light with respect to the change in the pattern height T (resist film thickness change) is extremely small, and the Stokes parameter for the resist film thickness. Tend to be less sensitive. This is because when the incident angle of the illumination light with respect to the wafer surface is large, the ratio of the reflected light from the adjacent convex patterns (recesses) decreases, and the ratio of the reflected light from the surface of the convex patterns increases. This is a predictable trend.
Further, since the measured value of the Stokes parameter is a function of the film thickness and the exposure condition, in order to obtain the film thickness and the exposure condition individually from the measured value of the Stokes parameter, a predetermined calculation or the like is performed as described below. .

  Next, in the present embodiment, the evaluation apparatus 1 is used to detect light from a repetitive pattern on the wafer surface, and the film thickness condition of the coater / developer 95 used when forming the pattern and the exposure apparatus 100 exposure. An example of a method for evaluating (inspecting) the conditions (here, the exposure amount and the focus position) will be described with reference to the flowchart of FIG. Since it is necessary to obtain an apparatus condition (evaluation condition) in advance for the evaluation, an example of a method for obtaining the apparatus condition (hereinafter also referred to as “conditioning”) will be described with reference to the flowchart of FIG. These operations are controlled by the control unit 80.

  The film thickness condition of the unexposed resist is evaluated below. The film thickness condition is reflected light from the repetitive pattern 12 formed through exposure by the exposure apparatus 100 and development in the coater / developer 95. Is evaluated based on the Stokes parameters. Therefore, in the following description, the change in the resist film thickness due to the exposure by the exposure apparatus 100 and the development by the coater / developer 95 is negligibly small, and the thickness of the unexposed resist formed by the coater / developer 95 (film) It is assumed that the thickness of the repetitive pattern formed by exposing the resist with the exposure apparatus 100 and developing with the coater / developer 95 is the same.

  First, in order to determine the conditions, in step 102 of FIG. 4, seven wafers 10a, 10b, 10c, 10d, 10e, 10f, and 10g coated with resists with different thicknesses are prepared in the coater / developer 95, respectively. . Of these wafers 10a to 10g, the wafer 10a is shown in FIG. As shown in FIG. 6A, on the surface of the wafer 10a (the same applies to the other wafers 10b to 10g), as an example, N pieces (N is an integer of about several 10 to 100) with the scribe line region SL interposed therebetween. Of shots 11 are arranged. Hereinafter, the nth shot 11 on the surface of the wafer 10a is referred to as a shot SAn (n = 1 to N). Then, the resist-coated wafer 10a is transported to the exposure apparatus 100 in FIG. 1A, and the exposure apparatus 100 scans the wafer 10a, for example, in the scanning direction during scanning exposure (a direction along the Y axis in FIG. 6A). The exposure amount gradually changes between shots arranged in a), and the focus position gradually changes between shots arranged in a non-scanning direction orthogonal to the scanning direction (the direction along the X axis in FIG. 6A). As described above, a pattern of a mask (not shown) for a device that is actually a product is exposed on each shot SAn while changing the exposure conditions.

  Similarly, the other wafers 10b to 10g are sequentially exposed in the exposure apparatus 100 by changing the exposure amount and the focus position in the same shot arrangement with the same pattern as the pattern exposed on the wafer 10a. Thereafter, by developing the exposed wafers 10a to 10g, seven wafers (hereinafter referred to as conditionally adjusted wafers) 10a to 10g in which the pattern 12 is repeatedly formed on each shot SAn under different exposure conditions. Is created.

  In the following, it is assumed that a defocus amount with respect to the best focus position Zbe (herein referred to as a focus value) is used as the focus position. With respect to the focus position, as an example, the focus value is set in seven steps from −60 nm to 0 nm to +60 nm in increments of 20 nm. Numbers 1 to 7 of the focus value F on the horizontal axis in FIG. 7A and the like to be described later correspond to the seven stages of focus values (−60 to +60 nm). Note that the focus value can be set at any step and in any step, and can be set in multiple steps, for example, in increments of 10 nm or 30 nm, and the focus value can be set, for example, in increments of 25 nm from −200 nm to It can also be set to 17 steps of +200 nm.

  As an example, the exposure amount is 7 steps (11.5 mJ, 13.0 mJ, 14.5 mJ, 16.0 mJ, 17.5 mJ, 19.0 mJ, 20. 5 mJ). Numbers 1 to 7 of the exposure amount D on the horizontal axis in FIG. 7A and the like to be described later correspond to the seven exposure amounts. The exposure amount can also be set at an arbitrary step amount and at an arbitrary stage (for example, 9 stages).

  Further, as an example, the resist film thickness T of the conditionally adjusted wafers 10a to 10g is set in seven steps (35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, and 65 nm) in steps of 5 nm around the optimum film thickness Tbe. The For example, the film thickness of the conditionally adjusted wafer 10d is set to the optimum film thickness Tbe. Numbers 1 to 7 of the film thickness T on the horizontal axis in FIG. 7A described later correspond to the seven stages of film thickness. Further, as an example, the focus value, the exposure amount, and the film thickness range of the non-defective product are respectively expressed as an allowable range EG1 (for example, a focus position, an exposure amount, and a film thickness at which the manufactured device does not cause a malfunction). The allowable range EG1 is actually different from each other in focus value, exposure amount, and film thickness.

  The conditionally controlled wafers 10a to 10g of the present embodiment are a plurality of so-called FEM wafers (Focus Exposure Matrix wafers) that have different film thicknesses and are exposed and developed by oscillating exposure amounts and focus positions in a matrix. When the number of shots with different combinations of exposure conditions obtained by the product of the number of focus value stages and the number of exposure dose stages is greater than the number of shots on the entire surface of one conditionally adjusted wafer 10a, the same film is used. A plurality of thickly conditioned wafers may be created.

  Conversely, for example, when the number of arrangements of shots SAn in the non-scanning direction is larger than the number of stages of change in focus value and / or when the number of arrangements in the scanning direction is larger than the number of stages of change in exposure amount, A plurality of shots having the same value and exposure amount may be formed, and the measurement values obtained for the shots having the same focus value and exposure amount may be averaged. In addition, for example, the influence of subtle application unevenness of the resist between the central portion and the peripheral portion of the wafer, the influence of the difference in the scanning direction of the wafer (+ Y direction or −Y direction in FIG. 2B) at the time of scanning exposure, etc. In order to reduce, a plurality of shots having different focus values and exposure amounts may be arranged at random.

  When the conditionally controlled wafers 10 a to 10 g are created, the conditionally controlled wafers 10 a to 10 g are sequentially transferred onto the stage 5 of the evaluation apparatus 1. Then, the control unit 80 reads out a plurality of device conditions from the recipe information in the storage unit 85. As a plurality of apparatus conditions, for example, the wavelength λ of the illumination light ILI is any one of the above λ1, λ2, and λ3, and the incident angle θ1 of the illumination light ILI (the exit angle θ2 of the reflected light) is 10 °, 15 °, 30 °, 45 °, 60 °, or 85 °, and the polarizer angle or polarization angle, which is the rotation angle of the polarizer 26 (the direction of the transmission axis), is either 0 ° to 165 ° in 15 ° increments. Assume the condition set for the angle. Here, the wavelength λ is λn (n = 1 to 3), the incident angle θ1 is αm (m = 1 to 6), and the rotation angle of the polarizer 26 is βj (j = 1 to J, where J is an integer of 2 or more). Can be expressed by the condition ε (n−m−j).

Further, the incident angle θ1 may be an arbitrary settable angle, and may be set at an interval of about 5 ° so as to be any one of 10 ° to 85 °, for example. In addition, the polarizer angle may be set to a plurality of angles with the reference angle as a center with respect to the direction parallel to the illumination light incident surface with respect to the wafer surface.
Then, in the evaluation apparatus 1, with the first conditionally adjusted wafer 10a placed on the stage 5, the wavelength of the illumination light ILI is set to λ1 (step 104), and the incident angle θ1 is set to α1 (also together) The tilt angle of the stage 5 is set, the light receiving angle of the light receiving system 30 is set (step 106), the rotation angle (polarizer angle) of the polarizer 26 is set to β1 (step 108), and the ¼ wavelength is set. The rotation angle of the plate 33 (phase plate) is set to an initial value (step 110). Then, under this apparatus condition, the illumination light ILI is irradiated onto the surface of the first conditionally adjusted wafer 10a, and the imaging device 35 detects the conditionally adjusted wafer 10a based on the regular reflection light from the conditionally adjusted wafer 10a. An image is captured and an image signal is output to the image processing unit 40 (step 112). Next, it is determined whether or not the quarter-wave plate 33 is set to all angles (step 114). If the quarter-wave plate 33 is not set to all angles, the quarter-wave plate 33 is set to, for example, about 1.41. The angle is rotated by ° (angle obtained by dividing the rotatable angle range 360 ° of the quarter-wave plate 33 by 256) (step 116), and the process returns to step 112 to capture an image of the conditioned wafer 10a. By repeating step 112 until the angle of the quarter-wave plate 33 is rotated by 360 ° in step 114, images of 256 wafers are picked up corresponding to different rotation angles of the quarter-wave plate 33. Since there are four unknowns regarding the Stokes parameters (S0 to S3), the angle of the quarter-wave plate 33 may be set to four different angles, for example, and only four images of the wafer may be captured. Any other arbitrary number may be used.

  Thereafter, the operation proceeds from step 114 to step 118, and the image processing unit 40 performs Stokes parameters S0 to S3 for each pixel of the image sensor 35b by the above-described rotational phase shift method from the obtained digital images of 256 wafers. Ask for. In the present embodiment, since the Stokes parameter S0 is standardized to be 1, the Stokes parameters that are actually obtained are S1 to S3 below. These Stokes parameters S1 to S3 are output to the first calculation unit 60a of the inspection unit 60, and the first calculation unit 60a obtains, as an example, an average value for each shot of each Stokes parameter (hereinafter referred to as a shot average value). , Output to the second calculation unit 60b and the storage unit 85 in correspondence with the apparatus condition ε (n−m−j), the film thickness, and the exposure condition.

  Thereafter, it is determined whether or not the rotation angle of the polarizer 26 is set to all angles (step 120). If not set to all angles, the polarizer 26 is rotated by, for example, 15 ° to an angle β2. Set (step 122) and return to step 110. Then, the Stokes parameters for each pixel of the image on the wafer surface, the shot average value, and the like (steps 110 to 118) are executed by the rotational phase shift method. Thereafter, when the rotation angles of the polarizer 26 are set to all the angles βj (j = 1 to J), the process proceeds from step 120 to step 124, and the incident angle θ1 of the illumination light ILI is set to all the angles. If it is not set to all angles, the illumination system 20 and the stage 5 are driven, the incident angle θ1 is set to α2 (step 126), and the process returns to step 108. Then, the Stokes parameters for each pixel of the wafer surface image, the shot average value, and the like (steps 108 to 122) are executed by the rotational phase shift method.

  Thereafter, when the incident angles θ1 are set to all the angles αm (m = 1 to 6), the process proceeds from step 124 to step 128 to determine whether or not the wavelengths λ of the illumination light ILI are set to all the wavelengths. If the wavelength is not set to all wavelengths, the illumination unit 21 changes the wavelength λ to λ2 (step 130) and returns to step 106. Then, the Stokes parameters for each pixel of the image on the wafer surface, the shot average value, and the like (steps 106 to 126) are executed by the rotational phase shift method. Thereafter, when the wavelengths λ are set to all the wavelengths λn (n = 1 to 3), the Stokes in steps 104 to 130 is performed on the next condition wafer 10b (not shown) having a different film thickness. Repeat the parameter measurement operation. Similarly, the Stokes parameter measurement operation in steps 104 to 130 is repeated for the third to seventh conditionally adjusted wafers 10c to 10g (not shown) having different film thicknesses. Thereafter, the operation proceeds from step 128 to step 132.

  In step 132, the second computing unit 60b uses the Stokes parameter information measured for each shot of all the conditionally controlled wafers 10a to 10g under the above-described all apparatus conditions, and the Stokes parameter measured under all the apparatus conditions. Regarding S1 to S3, sensitivity (hereinafter also referred to as film thickness sensitivity) which is a ratio (inclination) of a change in measurement value with respect to a change in film thickness T, sensitivity (hereinafter referred to as a ratio of change in measurement value with respect to change in exposure amount). And also a sensitivity (hereinafter also referred to as focus sensitivity) which is a ratio of a change in the measured value with respect to a change in the focus value.

  In the second calculation unit 60b, the film thickness sensitivity is particularly low, the dose sensitivity is high, and the focus sensitivity is any of the Stokes parameters S1 to S3 among all the apparatus conditions ε (n−m−j). A condition where the sensitivity is lower than the dose sensitivity is determined as a first apparatus condition (or a first evaluation condition) A. As an example of the first apparatus condition A, the wavelength of the illumination light is λ1, the incident angle θ1 of the illumination light with respect to the wafer surface is 85 °, and the rotation angle (polarizer angle) of the polarizer 26 is 45 °.

  As an example, in the first apparatus condition A, the Stokes parameters S1 and S2 are respectively shown in FIGS. 7A and 7B with respect to the exposure amount D, the focus value F, and the film thickness T of the conditionally adjusted wafers 10a to 10g. Changes as shown. Numerical values 1 to 7 on the horizontal axis of FIGS. 7A and 7B represent the respective stages when the exposure amount D, the focus value F, and the film thickness T are changed to the above-described seven stages. Four stages are optimum values. The same applies to FIGS. 8A and 8B and FIGS. 9A and 9B.

  7A and 7B, dotted curves (or broken lines; the same applies hereinafter) BD1 and BD2, dashed curves BF1 and BF2, and solid curves BT1 and BT2 are the exposure amount D and the focus value F, respectively. , And changes in the Stokes parameters S1 and S2 with respect to changes in the film thickness T. 7A and 7B, the curves BT1 and BT2 are almost flat, so that the ratio of change in the Stokes parameters S1 and S2 with respect to the change in the film thickness T (film thickness sensitivity) is particularly low. Further, since the slopes of the curves BD1 and BD2 are large, it can be seen that the dose sensitivity of the Stokes parameters S1 and S2 is high. For practical use, the first threshold value of the absolute value of the inclination is determined in advance, and the film thickness sensitivity is particularly great when the absolute value of the average inclination of the curves BT1 and BT2 is smaller than the first threshold value. The first apparatus condition A may be selected from the apparatus conditions that are regarded as low and the film thickness sensitivity is particularly low. In this example, since the absolute values of the slopes of the curves BF1 and BF2 are smaller than the absolute values of the slopes of the curves BD1 and BD2, respectively, it can be seen that the focus sensitivity of the Stokes parameters S1 and S2 is lower than the dose sensitivity. Furthermore, since the signs of the slopes of the curves BF1 and BF2 are opposite, it can be seen that the signs of the changes in the Stokes parameters S1 and S2 with respect to the changes in the focus value F are opposite.

  When the average slopes of the curves BD1 and BF1 are a1 and c1 (<a1), the average slopes of the curves BD2 and BF2 are a2 and c2 (−c2 <a2), and the offsets are d1 and d2, FIG. The Stokes parameters S1 and S2 of a) and (b) can be approximately expressed as a function of the exposure amount D and the focus value F as follows. Note that, under the first apparatus condition A, the Stokes parameters S1 and S2 are considered not to depend on the film thickness T.

S1 = a1 · D + c1 · F + d1 (2A)
S2 = a2 · D + c2 · F + d2 (2B)
Then, the second calculation unit 60b subtracts an expression obtained by multiplying the expression (2B) by the expression (2B) from the expression (2A) to obtain a function of only the exposure amount D as follows.
S1- (c1 / c2) S2
= {A1- (c1 / c2) a2} D + d1- (c1 / c2) d2 (2C)
Assuming that the coefficient and offset of the exposure dose D in this equation are a7 and d7, respectively, the following arithmetic expression corresponding to the straight line BS1 in FIG. The horizontal axis of FIG. 7C is the exposure amount D, and EG2A on the horizontal axis is a non-defective range of the exposure amount D. The coefficient a7 and the offset d7 are values obtained from the measured values related to the Stokes parameters S1 and S2.

S1− (c1 / c2) S2 = a7 · D + d7 (2D)
This arithmetic expression (2D) becomes the first template (first template information). The second calculation unit 60b stores the determined first device condition A and the first template in the storage unit 85.
In the next step 134, in the second computing unit 60b, the film thickness sensitivity and the dose sensitivity are high with respect to any one of the Stokes parameters S1 to S3 in all the apparatus conditions ε (n−m−j). A condition where the focus sensitivity is lower than the film thickness sensitivity and the dose sensitivity is determined as the second apparatus condition (or second evaluation condition) B. As an example of the second apparatus condition B, the wavelength of the illumination light is λ1, the incident angle θ1 of the illumination light with respect to the wafer surface is approximately 60 °, and the polarizer angle is 45 °.

  As an example, in the second apparatus condition B, the Stokes parameters S1 and S2 are respectively shown in FIGS. 8A and 8B with respect to the exposure amount D, the focus value F, and the film thickness T of the conditionally adjusted wafers 10a to 10g. Changes as shown. 8A and 8B, dotted curves BD3 and BD4, dashed curves BF3 and BF4, and solid curves BT3 and BT4 are Stokes with respect to changes in exposure dose D, focus value F, and film thickness T, respectively. It represents the change of the parameters S1 and S2. 8A and 8B, the absolute values of the slopes of the curves BT3 and BT4 are large (however, the signs are opposite), and the absolute values of the slopes of the curves BD3 and BD4 are also large (however, the signs are reversed). It can be seen that the film thickness sensitivity and dose sensitivity of the Stokes parameters S1, S2 are high. In practice, a second threshold value of the absolute value of the slope is determined in advance, and the absolute value of the average slope of the curves BT3 and BT4 and the absolute value of the average slope of the curves BD3 and BD4 are respectively determined. Even when the second apparatus condition B is selected from the apparatus conditions having high film thickness sensitivity and dose sensitivity, the film thickness sensitivity and dose sensitivity are regarded as high when the second threshold value is exceeded. Good. Further, since the slopes of the curves BF3 and BF4 are smaller than the absolute values of the slopes of the other curves BT3 and BD3, it can be seen that the focus sensitivity of the Stokes parameters S1 and S2 is lower than the film thickness sensitivity and the dose sensitivity.

When the average slopes of the curves BD3, BT3, and BF3 are a3, b3, and c3, the average slopes of the curves BD4, BT4, and BF4 are a4, b4, and c4, and the offsets are d3 and d4, FIG. The Stokes parameters S1 and S2 in (b) can be approximately expressed as a function of the exposure amount D, the film thickness T, and the focus value F as follows.
S1 = a3 · D + b3 · T + c3 · F + d3 (3A)
S2 = a4 · D + b4 · T + c4 · F + d4 (3B)
Then, the second arithmetic unit 60b subtracts an expression obtained by multiplying the expression (3A) by the expression c3 / c4 from the expression (3A) to obtain a function of only the exposure amount D and the film thickness T as follows.

S1- (c3 / c4) S2 = {a3- (c3 / c4) a4} D +
{B3- (c3 / c4) b4} T + d3- (c3 / c4) d4 (3C)
When the exposure amount D and the coefficient of the film thickness T and the offset of this equation are a8, b8, and d8, respectively, the following arithmetic expression is obtained. The coefficients a8 and b8 and the offset d8 are values obtained from the measured values related to the Stokes parameters S1 and S2.

S1- (c3 / c4) S2 = a8.D + b8.T + d8 (3D)
In this arithmetic expression, an expression in which the exposure amount D is set to a certain value corresponds to the straight line BS2 in FIG. The horizontal axis of FIG. 8C is the film thickness T, and EG2B on the horizontal axis is a non-defective range of the film thickness T.
This arithmetic expression (3D) becomes the second template (second template information). The second calculation unit 60b stores the determined second device condition B and the second template in the storage unit 85.

  In the next step 136, in the second computing unit 60b, the film thickness sensitivity and the focus sensitivity are high with respect to any of the Stokes parameters S1 to S3 in all the apparatus conditions ε (n−m−j) described above. A condition in which the dose sensitivity is lower than the film thickness sensitivity and the focus sensitivity is determined as a third apparatus condition (or a third evaluation condition) C. As an example, the third apparatus condition C is that the wavelength of illumination light is λ1, the incident angle θ1 of the illumination light with respect to the wafer surface is 10 ° close to the minimum value, and the polarizer angle is 10 °.

  As an example, in the third apparatus condition C, the Stokes parameters S1 and S2 are respectively shown in FIGS. 9A and 9B with respect to the exposure amount D, the focus value F, and the film thickness T of the conditionally adjusted wafers 10a to 10g. Changes as shown. 9A and 9B, dotted curves BD5 and BD6, broken curve BF5 and BF6, and solid curve BT5 and BT6 are Stokes with respect to changes in exposure dose D, focus value F, and film thickness T, respectively. It represents the change of the parameters S1 and S2. 9A and 9B, the absolute values of the slopes of the curves BT5 and BT6 are large (however, the signs are opposite), and the absolute values of the slopes of the curves BF5 and BF6 are also large (however, the signs are reversed). It can be seen that the film thickness sensitivity and focus sensitivity of the Stokes parameters S1 and S2 are high. In practice, a third threshold value of the absolute value of the slope is determined in advance, and the absolute value of the average slope of the curves BT5 and BT6 and the absolute value of the average slope of the curves BF5 and BF6 are respectively determined. When it becomes larger than the third threshold value, it is considered that the film thickness sensitivity and the focus sensitivity are high, and even if the third apparatus condition C is selected from the apparatus conditions having such a high film thickness sensitivity and focus sensitivity. Good. Further, since the slopes of the curves BD5 and BD6 are smaller than the absolute values of the slopes of the other curves BT5 and BF5, it can be seen that the dose sensitivity of the Stokes parameters S1 and S2 is lower than the film thickness sensitivity and the focus sensitivity.

Assuming that the average slopes of the curves BD5, BT5, and BF5 are a5, b5, and c5, the average slopes of the curves BD6, BT6, and BF6 are a6, b6, and c6, and the offsets are d5 and d6, FIG. The Stokes parameters S1 and S2 in (b) can be approximately expressed as a function of the exposure amount D, the film thickness T, and the focus value F as follows.
S1 = a5 · D + b5 · T + c5 · F + d5 (4A)
S2 = a6 * D + b6 * T + c6 * F + d6 (4B)
Then, the second calculation unit 60b subtracts an expression obtained by multiplying Expression (4B) by Expression (4B) from Expression (4A) to obtain a function of only the film thickness T and the focus value F as follows.

S1- (a5 / a6) S2 = {b5- (a5 / a6) b6} T +
{C5- (a5 / a6) c6} F + d5- (a5 / a6) d6 (4C)
When the coefficient of film thickness T and the focus value F, and the offset of this equation are b9, c9, and d9, respectively, the following arithmetic expression is obtained. The coefficients b9 and c9 and the offset d9 are values obtained from the measured values related to the Stokes parameters S1 and S2.

S1− (a5 / a6) S2 = b9 · T + c9 · F + d9 (4D)
In this arithmetic expression, an expression in which the film thickness T is set to a certain value corresponds to the straight line BS3 in FIG. The horizontal axis of FIG. 9C is the focus value F, and EG2C on the horizontal axis is the non-defective range of the focus value F. The arithmetic expression (4D) becomes the third template (third template information). The second calculation unit 60b stores the determined third device condition C and the third template in the storage unit 85.

  With the above operation, the condition determination for obtaining the apparatus conditions (here, three apparatus conditions) used when inspecting the wafer exposure conditions is completed. In the present embodiment, among the Stokes parameters measured under these apparatus conditions, only the Stokes parameters S1 and S2 are used as template information. For this reason, the Stokes parameters S1 and S2 can be referred to as a first specified condition and a second specified condition that define the polarization state of the light reflected from the wafer surface, respectively.

  Next, in the actual device manufacturing process, the above conditions are applied by the evaluation apparatus 1 to the wafer on which a repeated pattern is formed by application of a resist by the coater / developer 95, exposure by the exposure apparatus 100, and development by the coater / developer 95. By measuring the Stokes parameters of the reflected light from the wafer surface using the three apparatus conditions obtained in the process, the film thickness condition of the coater / developer 95 and the exposure amount and the focus position in the exposure condition of the exposure apparatus 100 Is evaluated as follows. First, the wafer 10 which has the same shot arrangement as that in FIG. 6A and is an actual product (device) coated with a resist is transported to the coater / developer 95 in FIG. 10 is transferred to the exposure apparatus 100, and the exposure apparatus 100 exposes a mask (not shown) pattern for an actual product (device) to each shot SAn (n = 1 to N) of the wafer 10. The wafer 10 is conveyed to the coater / developer 95 to develop the wafer 10. At this time, the film thickness condition and the exposure condition are the optimum values according to the resist used in all shots, and the exposure amount is the best dose amount determined according to the mask, The focus position is the best focus position.

  However, in actuality, there is a risk that an unintended shift in the average value of film thickness or an increase in dispersion may occur due to uneven coating on the wafer 10 in the coater / developer 95. Further, the exposure apparatus 100 has, for example, a slight illuminance unevenness in the slit-shaped illumination area at the time of scanning exposure, for example, a slight illuminance unevenness in the non-scanning direction, and stage vibration (including vibration due to disturbance). Variations in exposure amount and focus position may occur in each repeated pattern for each shot SAn, and unintended changes in exposure amount (changes from the best dose amount) and unintentional changes in focus position (from the best focus value). Change), the film thickness, exposure amount, and focus position are individually evaluated.

  In step 150 of FIG. 5, the resist-coated, exposed and developed wafer 10 is loaded onto the stage 5 of the evaluation apparatus 1 of FIG. 1A via an alignment mechanism (not shown). And the control part 80 reads the 1st, 2nd, 3rd apparatus conditions determined by said condition determination from the recipe information of the memory | storage part 85. FIG. First, the apparatus condition is set to the first apparatus condition A in which the film thickness sensitivity of the Stokes parameters S1 and S2 is extremely low (step 152), and the rotation angle of the quarter wavelength plate 33 (phase plate) is set to the initial value. Set (step 110A). Then, the illumination light ILI is irradiated onto the wafer surface, and the imaging device 35 outputs an image signal of the wafer surface to the image processing unit 40 (step 112A). Next, it is determined whether or not the quarter-wave plate 33 is set to all angles (step 114A). If the quarter-wave plate 33 is not set to all angles, the quarter-wave plate 33 is set to about 1.41 °, for example. It rotates by (an angle obtained by dividing the rotation angle range 360 ° by 256) (step 116A), and the process proceeds to step 112A to capture an image of the wafer 10. By repeating step 112A until the angle of the quarter-wave plate 33 is rotated by 360 ° in step 114A, images of 256 wafer surfaces corresponding to different rotation angles of the quarter-wave plate 33 are taken. . The angle of the quarter-wave plate 33 may be set to four different angles, for example, and only four images of the wafer may be taken, or any other number may be used.

  Thereafter, the operation proceeds to step 118A, and the image processing unit 40 obtains Stokes parameters S1 and S2 for each pixel of the imaging device 35 from the obtained digital images of 256 wafers by the above-described rotational phase shift method. In the present embodiment, since only the Stokes parameters S1 and S2 are used in the template information (formulas (2D) to (4D)) obtained under the above three apparatus conditions, only the Stokes parameters S1 and S2 are used here. Seeking. These Stokes parameters are output to the first calculation unit 60a of the inspection unit 60. The first calculation unit 60a obtains an average value (shot average value) for each shot of the Stokes parameters S1 and S2 as an example, and performs a third calculation. To the unit 60c and the storage unit 85. Then, it is determined whether or not the inspection is performed under all the apparatus conditions (step 154). If all the apparatus conditions for inspection are not set, the second apparatus condition B is set at step 156 and then the step. Move to 110A. After the acquisition of the Stokes parameter under the second apparatus condition B is completed, the third apparatus condition C is set at Step 156 and then the process proceeds to Step 110A, where the Stokes parameter is acquired under the third apparatus condition C. To do. Then, when the acquisition (inspection) of the Stokes parameters under the first, second, and third apparatus conditions is completed in step 154, the operation proceeds to step 158.

In step 158, the third calculation unit 60c of the inspection unit 60 uses the values of the Stokes parameters S1 and S2 (S1a and S2a) for each shot of the wafer 10 obtained under the first apparatus condition A as described above. By applying to the left side of the first template (calculation expression (2D)) stored in step 132 of FIG. 4, the following expression is obtained with respect to the exposure amount D of the shot.
y1 = S1a− (c1 / c2) S2a = a7 · D + d7 (2E)

  Further, the third calculation unit 60c obtains the value Dx1 of the exposure amount D from the equation (2E) (see FIG. 7C). As a result, the exposure amount D for each shot of the wafer 10 is obtained. Then, the third calculation unit 60 c calculates a distribution (error distribution) of a difference (error) from the best dose amount Dbe of the exposure amount D for each shot of the wafer 10, and outputs this to the control unit 80. This error distribution also includes information on whether or not the exposure amount D of each shot is within the non-defective range. The control unit 80 stores the error distribution of the exposure amount D for each shot in the storage unit 85 and displays it on a display device (not shown). Note that the third calculation unit 60c is not limited to the error distribution of the exposure amount D, and may output the calculated exposure amount D to the control unit 80, for example. Further, the control unit 80 may not display the error distribution of the exposure dose D or the exposure dose D on the display device.

  In the next step 160, the third computing unit 60c determines the Stokes parameters S1 and S2 for each shot of the wafer 10 obtained under the second apparatus condition B (referred to as S1b and S2b) and the shot obtained in step 158. The value Dx1 of each exposure amount D is applied to the second template (calculation expression (3D)) stored in step 134 described above, and the following expression is obtained for the shot.

y2 = S1b- (c3 / c4) S2b = a8.Dx1 + b8.T + d8 (3E)
This equation corresponds to the straight line BS2 in FIG. And the 3rd calculating part 60c calculates | requires the value Tx1 of the film thickness T from Formula (3E). As a result, the film thickness T for each shot of the wafer 10 is obtained. Further, the third calculation unit 60 c obtains a difference (error) distribution (error distribution) from the optimum value Tbe of the film thickness for each shot of the wafer 10, and outputs this to the control unit 80. This error distribution also includes information on whether or not the film thickness T of each shot is within the non-defective range. The control unit 80 stores the error distribution of the film thickness T for each shot in the storage unit 85 and displays it on a display device (not shown). Note that the third calculation unit 60c is not limited to the error distribution of the film thickness T, and may output the calculated exposure amount T to the control unit 80, for example. Further, the controller 80 may not display the error distribution of the film thickness T or the film thickness T on the display device.

  In the next step 162, the third computing unit 60 c determines the values of Stokes parameters S 1 and S 2 for each shot of the wafer 10 obtained under the third apparatus condition B (referred to as S 1 c and S 2 c) and for each shot obtained in step 158. The value Dx1 of the exposure amount D and the value Tx1 of the film thickness T for each shot obtained in step 160 are applied to the third template (calculation equation (4D)) stored in step 136 described above, and Get the formula.

y3 = S1c− (a5 / a6) S2c = b9 · Tx1 + c9 · F + d9 (4E)
This equation corresponds to the straight line BS3 in FIG. And the 3rd calculating part 60c calculates | requires the value Fx1 of the focus value F from Formula (4E). As a result, the focus value F for each shot of the wafer 10 is obtained. Further, the third calculation unit 60 c obtains a difference (error) distribution (error distribution) from the best focus position of the focus value F for each shot of the wafer 10, and supplies this to the control unit 80. This error distribution also includes information on whether or not the focus value F of each shot is within the non-defective range. The control unit 80 stores the error distribution of the focus value F for each shot in the storage unit 85 and displays it on a display device (not shown). Note that the third calculation unit 60c is not limited to the error distribution of the focus F, and may output the calculated focus F to the control unit 80, for example. The control unit 80 may not display the error distribution of the focus F or the focus F on the display device.

  Thereafter, under the control of the control unit 80 of the evaluation apparatus 1, an error distribution of the resist film thickness for each shot on the entire surface of the wafer 10 is transferred from the signal output unit 90 to the control unit (not shown) of the coater / developer 95. Information on so-called coating unevenness is provided (step 164). In the case where the coating unevenness is out of the target range or is also biased within the target range, the coater / developer 95 has various conditions for forming a resist on the wafer surface (for example, the resist coating amount, The film thickness condition is corrected by adjusting the heat treatment temperature and time.

  Further, from the signal output unit 90 of the evaluation apparatus 1 to the control unit (not shown) of the exposure apparatus 100, the exposure amount error distribution (exposure amount unevenness) and the focus position error distribution (defocus amount amount) for each shot of the wafer 10. Distribution) information is provided (step 164). In response to this, a control unit (not shown) of the exposure apparatus 100 sets the exposure amount and / or the focus position when, for example, the unevenness of the exposure amount and / or the distribution of the defocus amount exceeds a predetermined allowable range. In order to correct, for example, correction of the distribution of the width in the scanning direction of the illumination area at the time of scanning exposure, or adjustment of the offset of the height of the wafer surface is performed. Thereby, the resist film thickness error, the exposure amount error, and the defocus amount are reduced during the subsequent exposure. Thereafter, in step 168, the coater / developer 95 applies a resist to the next wafer under the corrected condition, and in step 170, the exposure apparatus 100 exposes the wafer under the corrected exposure condition.

  According to this embodiment, the Stokes parameters are detected under three apparatus conditions using the wafer 10 on which a pattern for a device that is actually a product is formed, and the conditions shown in FIG. By sequentially applying the detected Stokes parameter values to the first to third template information obtained in the extraction process, the film thickness condition of the coater / developer 95 used at the time of forming the pattern, and the exposure apparatus An exposure amount and a focus position in 100 exposure conditions can be obtained. In other words, in each apparatus condition, the film thickness condition, the exposure amount, and the change rate (sensitivity) of the Stokes parameter to the change in the focus position are different from each other, and the film thickness condition, the exposure amount, Further, by utilizing the fact that the ratio (sensitivity) of the Stokes parameter change amount to the focus position change amount is different from each other, the film thickness condition, the exposure amount, and the focus position can be individually evaluated or inspected with high accuracy. Therefore, by correcting the film thickness condition in the coater / developer 95 and / or the exposure condition in the exposure apparatus 100 based on this evaluation result, the film thickness and the exposure condition for the subsequent wafer can be brought closer to the proper range. Devices can be manufactured with high accuracy and high yield.

  As described above, the evaluation apparatus 1 and the evaluation method of the present embodiment are configured such that the concave and convex repeated pattern 12 (test pattern) provided on the wafer 10 by a lithography process including resist application, pattern exposure, and resist development. Apparatus and method for evaluating film thickness conditions (such as film thickness offset) and exposure conditions (for example, exposure amount and focus position). The evaluation apparatus 1 includes an illumination system 20 that illuminates linearly polarized illumination light ILI (polarized light) on the surface of the wafer 10 (substrate to be tested) on which the repeated pattern 12 is formed, and illumination of the illumination system 20. The image pickup device 35 and the image processing unit 40 (detection unit) that receive the light reflected from the surface thereof and detect the Stokes parameters (conditions for defining the polarization state) of the light, and the repetitive patterns on the conditionally controlled wafers 10a to 10g Expressions (2D), (3D), (4D) (data) showing the relationship between the film thickness conditions and exposure conditions when forming 12 (predetermined pattern) and the Stokes parameters S1, S2, and reflection from the surface And an arithmetic unit 50 that evaluates the film thickness condition and the exposure condition when the repetitive pattern 12 is formed based on the Stokes parameters S1 and S2 of the light.

  Further, in the evaluation method of the present embodiment, the step 112A of illuminating the surface of the wafer 10 on which the repeated pattern 12 is formed with polarized light is received, and the light reflected from the surface by the illumination of the polarized light is received. Step 118A for detecting the Stokes parameter of the light, film thickness conditions and exposure conditions (for example, exposure amount and focus position) when the pattern 12 is repeatedly formed on the conditionally adjusted wafers 10a to 10g, and the Stokes parameters S1 and S2 Based on arithmetic expressions (2D), (3D), and (4D) indicating the relationship, and Stokes parameters S1 and S2 of the light reflected from the surface, film thickness conditions and exposure conditions when the repeated pattern 12 is formed Are evaluated at steps 158 to 162.

  According to this embodiment, a wafer having a repetitive pattern 12 for a device that is actually a product provided by application of a resist under a predetermined film thickness condition and exposure under a predetermined exposure condition. 10 is used to detect the Stokes parameters S1 and S2, and the three Stokes parameters (2D), (3D), and (4D) (first to third template information) obtained in advance are added to the detected Stokes parameters. By applying the values of the parameters S1 and S2, the film thickness condition of the coater / developer 95 used at the time of forming the repeated pattern 12, and the exposure amount and the focus position in the exposure condition of the exposure apparatus 100 can be obtained. In other words, the detected Stokes parameters S1 and S2 are expressed in the three arithmetic expressions (2D), (3D), and (4D) that represent the Stokes parameters as a function of film thickness, exposure amount, and focus position. By solving the three equations obtained by fitting with respect to the film thickness condition, the exposure amount, and the focus position, the film thickness condition, the exposure amount, and the focus position can be obtained individually with high accuracy. The film thickness condition and exposure condition when formed can be individually evaluated with high accuracy. Furthermore, there is no need to use a separate evaluation pattern, and the film thickness and exposure conditions can be evaluated by detecting light from the wafer on which the device pattern that will actually be the product is formed. The film thickness condition and the exposure condition related to the pattern to be performed can be evaluated efficiently. Moreover, since the film thickness condition and the exposure condition can be obtained by the evaluation apparatus 1, the film thickness condition and the exposure condition can be obtained efficiently without using separate apparatuses.

Of the conventional methods for evaluating the focus position as the exposure condition, the method of measuring the lateral shift amount of the resist pattern is difficult to increase the measurement efficiency and illuminates the mask evaluation pattern with illumination light whose chief ray is inclined. Therefore, it has been difficult to accurately measure the focus position when performing exposure using an actual device pattern. On the other hand, according to the present embodiment, an actual device pattern can be used, and it is not necessary to measure the shape of the formed resist pattern. Therefore, in the process of forming the actual device pattern The exposure conditions can be obtained efficiently and with high accuracy.
Further, according to the present embodiment, the film thickness conditions such as the film thickness distribution of the resist formed on the wafer can be obtained efficiently, so by feeding back the obtained film thickness conditions to the coater / developer, The film thickness of the resist formed on the wafer can be kept within the target range, and the yield of devices finally manufactured can be increased.

  Moreover, in this embodiment, the calculating part 50 is the 1st-3rd apparatus conditions or evaluation of the evaluation apparatus 1 for evaluating the film thickness conditions and exposure conditions at the time of forming the repeating pattern 12 on the surface of the wafer 10. FIG. Stokes parameters S1 and S2 of the light reflected from the surfaces of the conditionally controlled wafers 10a to 10g on which the pattern 12 is repeatedly formed under conditions where both the film thickness condition and the exposure condition are known. (Steps 104 to 136). As a result, when the wafer 10 is evaluated, the Stokes parameters need only be obtained using the obtained apparatus conditions or evaluation conditions, so that the wafer 10 can be evaluated efficiently.

  Further, the exposure system of the present embodiment includes a coater / developer 95 (coating apparatus) for applying a resist to the surface of the wafer, an exposure apparatus 100 having a projection optical system for exposing a pattern to the surface of the wafer, and the evaluation apparatus 1. The film thickness condition of the coater / developer 95 and the exposure condition in the exposure apparatus 100 are corrected according to the evaluation result of the calculation unit 50 of the evaluation apparatus 1. According to this exposure system, a coater / developer can be efficiently and accurately used so that a pattern having a target shape is formed on the surface of a wafer using a wafer that is actually used for device manufacture. The film thickness condition at 95 and the exposure condition at the exposure apparatus 100 can be adjusted.

In the above-described embodiment, the following modifications are possible.
First, in the above embodiment, the calculation formulas (2D), (3D), and (4D) (template information) are obtained by the calculation unit 50 of the evaluation device 1, but the template information is different from the evaluation device 1. For example, it may be obtained by a host computer (not shown) as the arithmetic unit. In this case, the template information is supplied from the host computer to the control unit 80 of the evaluation device 50 of the evaluation device 1, and the control unit 80 stores the template information in the storage unit 85. Then, as shown in FIG. 5, when obtaining the film thickness condition and the exposure condition, the template information stored in the storage unit 85 may be used.

In the above embodiment, the incident angle θ1 of the illumination light is adjusted by controlling the position of the exit portion of the light guide fiber 24 and the position and angle of the illumination-side concave mirror 25 via a drive mechanism (not shown). However, the incident angle θ1 of the illumination light can also be adjusted by controlling the tilt angle φ2 of the wafer 10 via the second drive unit. In this case, it is necessary to control the position and angle of the imaging device 35 while tilting the light-receiving side concave mirror 31 about the tilt axis TA.
In addition, when an oxide film or a conductive film is formed as a resist base in the substrate exposed by the exposure apparatus, a pattern such as an oxide film or a conductive film is formed by a process such as etching after developing the resist. The In order to form this pattern with high accuracy, it is preferable to evaluate the film thickness conditions of the oxide film or the conductive film. In this case, the wafer on which the pattern of the oxide film or the conductive film is formed is placed on the stage 5 in FIG. 1A, and the Stokes parameter of the reflected light from the wafer is obtained, thereby obtaining the above-described embodiment. Similarly, the film thickness condition of the oxide film or the conductive film can be evaluated.

  In the above embodiment, the Stokes parameters S1 and S2 are considered not to depend on the film thickness T under the first apparatus condition A. However, for example, the first apparatus condition A may be an apparatus condition in which the Stokes parameter changes greatly with respect to the dose and focus value changes and the Stokes parameter changes with respect to the film thickness change is small. In this case, the exposure amount D, the focus value F, and the film from the simultaneous equations (first to third templates) relating to the exposure amount D, the focus value F, and the film thickness T obtained from the measurement results of the three apparatus conditions. The thickness T can be determined individually.

In the above embodiment, the calculation formula (2D) is used as a template. However, the template is not limited to the calculation formula, and the value of the Stokes parameter for each exposure amount obtained under the first apparatus condition A described above. It is also possible to use data in a table form.
Further, in the above embodiment, the calculation formula (3D) is used as a template. However, the template is not limited to the calculation formula, and for each exposure amount and each film thickness obtained in the second apparatus condition B described above. Data in which Stokes parameter values are tabulated may be used.
In the above-described embodiment, the calculation formula (4D) is used as a template. However, the template is not limited to the calculation formula, and for each focus value and each film thickness obtained in the third apparatus condition C described above. Data in which Stokes parameter values are tabulated may be used.

In the above embodiment, it is assumed that the change in the resist film thickness due to exposure and development is negligible.
However, exposure depends on the type of resist used, apparatus conditions in the coater / developer (for example, resist coating amount, heat treatment temperature and time, etc.), exposure apparatus apparatus conditions (for example, exposure amount, focus position, etc.), etc. The height of the repeated pattern 12 formed after exposure may be lower than the previous resist film thickness (hereinafter referred to as film reduction). In this case, for example, a film reduction ratio may be obtained in advance, and the height of the repeated pattern 12 obtained in step 160 of FIG. 5 may be multiplied by the film reduction ratio. The rate of film reduction can be calculated by a known method. For example, the resist film thickness before exposure is obtained by a known film thickness meter (for example, an ellipsometer) and the pattern height after exposure is determined by a known method (for example, scatterometer or CD-SEM (scanning electron The ratio is obtained by a microscope), an ellipsometer, etc., and the ratio thereof may be set as the ratio of reducing the film. In the above-described embodiment, the film thickness of the resist before exposure is obtained in step 160 in the evaluation of FIG. 5, but the height of the pattern formed after exposure may be obtained. In this case, the film thickness condition is the pattern height (in other words, the pattern height condition). Even in this case, the height of the repeated pattern can be obtained through the steps of FIG. 4 (conditioning) and FIG. 5 (evaluation). By obtaining the pattern height, the exposure conditions of the exposure apparatus and the film thickness conditions formed by the coater / developer can be corrected in the same manner as described above.

  In the above-described embodiment, the film thickness and the exposure conditions are evaluated using the Stokes parameters S1 and S2. However, the film thickness condition and the exposure condition may be evaluated using at least one of the Stokes parameters S0 to S3. Further, different Stokes parameters may be used when evaluating the film thickness condition or the exposure condition.

In the above-described embodiment, both the film thickness condition and the exposure condition (for example, the exposure amount and the focus position) are evaluated. However, at least one of the film thickness condition and the exposure condition may be evaluated. At this time, when the exposure condition includes the exposure amount and the focus position, it is only necessary to evaluate at least one of the exposure amount and the focus position.
As an example, when evaluating the exposure amount condition among the film thickness condition and the exposure condition, the Stokes parameters are obtained only in the first apparatus condition and the second apparatus condition in steps 152 to 156 in FIG. Only need. Then, by executing Steps 158 and 160, the error distribution of the exposure amount and the error distribution of the film thickness can be obtained.

In this regard, as described with reference to FIG. 3, when the focus position changes, the Stokes parameters S1 and S3 of the reflected light tend to change relatively greatly, and the rate of change of the Stokes parameter S2 tends to be relatively small. . Therefore, when evaluating the film thickness condition and the exposure amount condition, the Stokes parameter S2 of the reflected light may be used.
Further, the focus position condition among the film thickness condition and the exposure condition may be evaluated. For this purpose, a condition in which the focus sensitivity of the Stokes parameter (any of S1 to S3) is higher than the dose sensitivity and the film thickness sensitivity is low is selected as the first apparatus condition described above, and the second apparatus condition described above is selected. As for the Stokes parameter (any one of S1 to S3), a condition in which the film thickness sensitivity and the focus sensitivity are high and the dose sensitivity is lower than the film thickness sensitivity and the focus sensitivity is selected, and in steps 152 to 156 in FIG. The Stokes parameters may be obtained based on only the first device condition and the second device condition, and steps 158 and 160 may be executed.

When only the film thickness condition is evaluated, as an example of the first apparatus condition, the Stokes parameter (any one of S1 to S3) is used in the condition where the incident angle of the illumination light with respect to the wafer surface is small. With regard to, a condition in which the film thickness sensitivity is larger than the dose sensitivity and the focus sensitivity may be selected. In addition, when the incident angle of illumination light is small, both the reflected light from the surface of the convex pattern and the reflected light from between adjacent convex patterns (concave portions) tend to increase, and thus the film thickness sensitivity tends to increase. There is. Therefore, the first apparatus condition is selected in the condition where the incident angle is small, and the Stokes parameter is obtained only by the first apparatus condition, thereby increasing the film thickness sensitivity and making the film thickness condition highly accurate. Can be evaluated.
In the above-described embodiment, the wafer is evaluated under three apparatus conditions (evaluation conditions). However, the wafer may be evaluated under at least one apparatus condition (evaluation conditions). .

  In addition, the wavelength λ, the incident angle θ1, and the rotation angle of the polarizer 26 included in the first to third apparatus conditions are merely examples, and the apparatus conditions include other arbitrary values that can be changed by the evaluation apparatus 1. Conditions can be included. For example, the condition that the rotation angle of the analyzer 32 is set to a plurality of angles at intervals of, for example, an arbitrary angle (for example, about 5 °) around the crossed Nicol state, or the rotation angle of the stage 5 (the orientation of the wafer 10). Etc. can be included in the apparatus conditions.

Further, in the above-described embodiment, since the film thickness and the exposure conditions are finally evaluated using the Stokes parameters S1 and S2, the Stokes parameters S1 and S2 are set in step 118 in the condition determination shown in FIG. Just ask.
In step 118, all shots SAn (see FIG. 6B) excluding the scribe line region SL (region serving as a boundary when the chips are cut in the device dicing process) of the conditioned wafer 10a are supported. The Stokes parameters of the pixels to be calculated may be calculated, and the calculation results may be averaged to obtain the shot average value. The reason why the shot average value is calculated in this way is to suppress the influence of the aberration of the projection optical system of the exposure apparatus 100 and the like. In order to further suppress the influence of the aberration and the like, for example, a value obtained by averaging the Stokes parameters of the corresponding pixels in the partial area CAn at the center of the shot SAn in FIG. 6B may be calculated.

  However, the influence of the aberration of the projection optical system (error distribution given to the digital image) can be obtained in advance, and the influence of the aberration can be corrected at the stage of the digital image. In this case, instead of the shot average value, the average value is calculated for each setting region 16 (see FIG. 6C) such as a rectangle of I (I is an integer of several tens) within the shot SAn. For example, the subsequent processing may be performed using the average value of the setting area 16 at the same position in the shot SAn. The arrangement of the setting areas 16 is, for example, 6 rows in the scanning direction and 5 columns in the non-scanning direction, but the size and arrangement are arbitrary.

Further, when the wafer 10 is evaluated, the average value of the Stokes parameters may be detected for all the setting areas 16 in all the shots of the wafer, and the film thickness and the exposure conditions may be evaluated for each setting area 16. .
Further, in steps 164 and 166 of FIG. 5, information on the film thickness distribution (coating unevenness) of the entire surface of the wafer 10, exposure error distribution (dose nonuniformity), and focus position error distribution (defocus amount distribution). Is output from the signal output unit 90 to a host computer (not shown) that comprehensively controls the operations of a plurality of exposure apparatuses, coater / developers, etc., instead of the coater / developer 95 and the control unit (not shown) of the exposure apparatus 100. May be. In this case, the host computer (not shown) may issue a command for correcting the film thickness condition and the exposure condition to the coater / developer 95 and the exposure apparatus 100 based on the output information. Alternatively, on the basis of the information output from the signal output unit 90, the host computer obtains apparatus conditions for correcting the film thickness condition and the exposure condition in the coater / developer 95 and the exposure apparatus 100, and each condition is obtained from the host computer. May be output to the coater / developer 95 or the exposure apparatus 100 to correct the film thickness condition and the exposure condition.

In the above-described embodiment, the template information (arithmetic expressions (2D), (3D), (4D)) stored in the storage unit 85 in steps 132 to 136 is an expression including the Stokes parameters, which is the exposure amount D and the film thickness. This is expressed by a primary arithmetic expression using at least one of T and focus position F as a parameter. However, as the template information, an approximate expression obtained by mathematically fitting a curve indicating a change in an arbitrary Stokes parameter with respect to a film thickness and an arbitrary exposure condition by an arbitrary quadratic function or an exponential function. May be used.
Further, as the template information, data obtained by tabulating the Stokes parameter values in addition to the arithmetic expression can be used.

  In the above-described embodiment, whether or not these amounts are within the non-defective range is evaluated from the exposure amount D, the film thickness T, and the focus position F obtained from the Stokes parameters. On the other hand, for example, when the Stokes parameters S1 and S2 are obtained under a certain apparatus condition and the exposure dose D is evaluated from these values, the two-dimensional distribution of the Stokes parameters S1 and S2 as shown in FIG. Among these, a good product range EG3, an overdose range EB1, and an underdose range EB2 may be set, and this two-dimensional distribution may be used as template information for determining the quality of the exposure amount. In this case, the values of the parameters S1 and S2 may be represented by (S1, S2), and the non-defective product range EG3 may be approximately inside a circle having the following center coordinates (sa, sb) and radius sr. When the value obtained by substituting the measured parameter values (S1, S2) into the arithmetic expression on the left side of Equation (5) satisfies Equation (5), the measured value is such that the exposure amount D is within the non-defective range. You are doing something.

(S2-sa) ² + (S3-sb) ² ≦ sr ² (5)
Similarly, regarding the film thickness T and the focus position F, a non-defective range or the like may be set in the two-dimensional distribution of the Stokes parameters S1 and S2.
In the above-described embodiment, the film thickness condition and / or the exposure condition are evaluated using the two Stokes parameters S1 and S2. As another method, three Stokes parameters S1, S2, and S3 are used, and as shown in FIGS. 11 (a), (b), and (c), the evaluation apparatus 1 is under certain apparatus conditions (evaluation conditions). A set of values of the Stokes parameters S1, S2, and S3 obtained in (1) may be expressed on a Poincare sphere.

  Using the plurality of conditionally adjusted wafers 10a to 10g in which the pattern 12 is repeatedly formed by changing the resist film thickness T, the exposure amount D, and the focus position F, the present inventor Each set of values of Stokes parameters S1 to S3 measured under a predetermined apparatus condition by the evaluation apparatus 1 was plotted on the Poincare sphere in FIG. As a result, the Stokes parameters S1 to S3 when the film thickness T, the exposure amount D, and the focus position F are optimum values are at one point MPC on the Poincare sphere, and when the focus position F changes from that state, It was found that the set of Stokes parameters S1 to S3 to be measured moves along the curve BCF1. Similarly, when the exposure amount D changes from the state of the point MPC, the set of measured Stokes parameters S1 to S3 moves along the curve BCD1 that intersects the curve BCF1 at a certain small angle, and the state of the point MPC It can be seen that when the film thickness T is changed, the set of Stokes parameters S1 to S3 to be measured moves along the curve BCT1 that intersects the curve BCD1 at a substantially smaller angle.

  As described above, the Stokes parameters S1 to S3 obtained from the pattern formed by changing the film thickness T, the exposure amount D, and the focus position F change along a substantially continuous curve on the Poincare sphere. For this reason, for example, using the coefficient kT1 obtained by plotting the curve BCT1, the error δT from the optimum value of the film thickness T at the position dt from the point MPC indicating the optimum value in the curve BCT1 is substantially the following. It can be approximated as follows. Tbe is the optimum value of the film thickness, and the distance dt is positive in the direction in which the error δT increases along the curve BCT1.

δT = Tbe + kT1 · dt (6)
If the Stokes parameters S1 to S3 at the point MPC are (S11, S21, S31) and the Stokes parameters S1 to S3 at the distance dt are (S12, S22, S32), the distance dt is It can be calculated as follows.
dt ² = (S12−S11) ² + (S22−S21) ² + (S32−S31) ² (6)

  Therefore, instead of setting the conditions in FIG. 4 of the above-described embodiment, the Stokes parameters S1 to S3 are measured under a number of apparatus conditions using a plurality of conditionally adjusted wafers 10a to 10g, and the measurement results are obtained. You may plot on a Poincare sphere. In this case, as an example, the device condition when the set of values of the Stokes parameters S1 to S3 changes along the curve BCF2 substantially parallel to the curve BCF1 in FIG. 11A is the first device condition, the Stokes parameter S1. The device condition when the value set of S3 changes along the curve BCD2 substantially parallel to the curve BCD1 of FIG. 11A is the second device condition, and the value set of the Stokes parameters S1 to S3 is The apparatus condition when changing along the curve BCT2 substantially parallel to the curve BCT1 of 11 (a) may be set as the third apparatus condition.

  When evaluating the film thickness and exposure conditions of the wafer 10 on which the actual repetitive pattern 12 is formed under these apparatus conditions, for example, the point MPT of the set of Stokes parameters S1 to S3 obtained under the third apparatus condition By obtaining the signed distance dtm from the optimum point MPC, the error of the film thickness T at the point MPT can be easily calculated from the equation (5). Similarly, an expression corresponding to Expression (5) is obtained by obtaining a signed distance between a point of the set of Stokes parameters S1 to S3 obtained under the first and second apparatus conditions and an optimum value point MPC. Thus, the error of the focus position F and the exposure amount D can be easily calculated.

  Further, as shown in FIG. 11C, it is possible to set a non-defective range EGC on the Poincare sphere. As an example, when the set of average values of the Stokes parameters S1 to S3 measured in a certain shot of the wafer 10 is within the non-defective range EGC, the film thickness T, the exposure amount D, and the focus position F are related to the shot. All can be considered to be in the non-defective range. In addition, the range of Stokes parameters S1 to S3 when the film thickness T, the exposure amount D, or the focus position F is in the non-defective range may be obtained individually for each apparatus condition.

  Further, in the above-described embodiment, in the condition determination in FIG. 4, the template information (calculation formula) is used by using the conditionally adjusted wafers 10 a to 10 g on which repeated patterns are formed by applying the resist in the coater / developer 95 and exposing the exposure apparatus 100. (2D), (3D), (4D)) is obtained, and the template information is used to evaluate the film thickness condition of the coater / developer 95 and the exposure condition of the exposure apparatus 100 used in the condition determination at the time of evaluation in FIG. Exposure amount and focus position) were determined. However, at the time of the evaluation of FIG. 5, using the template information (calculation expressions (2D), (3D), (4D)), the film thickness condition of a coater / developer (not shown) different from the coater / developer 95, and Alternatively, exposure conditions of an exposure apparatus (not shown) different from the exposure apparatus 100 may be obtained. In this case, a wafer on which a pattern is formed by a coater / developer different from the coater / developer 95 and / or an exposure apparatus different from the exposure apparatus 100 is evaluated as in steps 158 to 162 in FIG. The coater / developer and the exposure apparatus may be corrected like 164 and 166. Further, the wafer on which the pattern is formed by the coater / developer 95 and the exposure apparatus 100 is evaluated as in steps 158 to 162 in FIG. 5 described above, and from the evaluation results, in steps 164 and 166, the coater / developer 95 is defined. A different coater / developer and / or an exposure apparatus different from the exposure apparatus 100 may be corrected.

  Further, the inspection unit 60 may not only determine the film thickness condition and the exposure condition but also determine whether the obtained film thickness condition and the exposure condition are acceptable. In this case, the signal output unit 90 may provide a warning to the exposure apparatus 100 or the host computer that the film thickness condition or the exposure condition is not appropriate based on the quality determination result. This pass / fail determination may be performed, for example, by comparing the obtained film thickness condition or exposure condition with a predetermined threshold value.

Furthermore, in the above-described embodiment, the exposure amount and the focus position are evaluated as the exposure conditions. As the exposure conditions, the exposure light wavelength, the illumination conditions (for example, the coherence factor (σ value), and the projection optical system in the exposure apparatus 100 are evaluated. In order to evaluate the numerical aperture of the liquid or the temperature of the liquid during the immersion exposure, the evaluation of the above embodiment may be used.
Further, the evaluation method of the film thickness condition and the exposure condition of the above-described embodiment is a resist film for a wafer on which a repetitive pattern with a fine pitch is formed by a so-called spacer double patterning method (or sidewall double patterning method). The present invention can also be applied when evaluating the thickness condition and the exposure condition.

Furthermore, in the above-described embodiment, the illumination system 20 of the evaluation apparatus 1 in FIG. 1A collectively illuminates the entire surface of the wafer 10 with the polarized light, and the imaging device 35 (detection unit) 10 has an image sensor 35b that captures an image of the entire surface of the surface. For this reason, the film thickness and exposure conditions of the repeated pattern 12 formed on each shot on the entire surface of the wafer 10 can be efficiently evaluated.
On the other hand, an illumination system that illuminates a part of the surface of the wafer 10 (test substrate) with polarized light, an imaging device that captures an image of a part of the surface of the wafer 10, and a surface parallel to the surface of the wafer 10. An evaluation apparatus (not shown) including a stage movable in the X direction and the Y direction may be used. In the evaluation apparatus of this modification, the wafer 10 is moved by the stage so that the entire surface of the wafer 10 is sequentially irradiated with polarized light from the illumination system. In this modification, the surface of the wafer 10 is divided into a plurality of portions, and the film thickness and exposure conditions of the repeated pattern 12 formed in each portion are sequentially evaluated. Since the evaluation apparatus of this modification can be reduced in size, for example, it can be incorporated in the exposure apparatus 100 on-body. In this case, since the stage of the evaluation apparatus can also be used as the wafer stage (not shown) of the exposure apparatus 100, the configuration of the evaluation apparatus can be further simplified.

  In the above embodiment, the conditions that define the polarization state of light from the wafer are represented by Stokes parameters. However, the condition that defines the polarization state may be expressed by a Jones vector (Jones Vector) composed of two rows of complex column vectors for expressing the polarization characteristics of the optical system in the so-called Jones notation. The Jones notation is described in, for example, the reference `` M. Totzeck, P. Graeupner, T. Heil, A. Goehnermeier, O. Dittmann, DSKraehmer, V. Kamenov and DGFlagello: Proc. SPIE 5754, 23 (2005) ''. As described, a Jones matrix (Jones Matrix) composed of a 2 × 2 complex matrix (polarization matrix) for representing the polarization characteristics of the optical system, and a polarization state converted by the optical system For the Jones vector.

Further, a condition that defines the state of polarization may be expressed using both the Stokes parameter and the Jones vector. Furthermore, the conditions that define the state of polarization can be expressed by a so-called Mueller matrix.
In the above-described embodiment, the exposure apparatus 100 may be a scanning stepper using an immersion exposure method, or a dry type scanning stepper or a stepper. Furthermore, the above-described embodiment is also used when the exposure apparatus uses an EUV exposure apparatus that uses EUV light (Extreme Ultraviolet Light) having a wavelength of 100 nm or less as exposure light, or an electron beam exposure apparatus that uses an electron beam as an exposure beam. Is applicable.

  In this embodiment, the linearly polarized light obtained by converting the light from the light source unit 22 into linearly polarized light by the polarizer 26 is illuminated on the wafer, but the light that illuminates the wafer may not be linearly polarized light (see FIG. 1 (a)). For example, the wafer may be illuminated with circularly polarized light. In this case, for example, by providing a half-wave plate in addition to the polarizer 26, the light from the light source unit 22 is converted into circularly-polarized light by the polarizer 26 and the half-wave plate to illuminate the wafer. Further, the wafer may be illuminated with elliptically polarized light other than circularly polarized light. A known configuration other than the above can be applied to the configuration for converting the light from the light source unit 22 into linearly polarized light or elliptically polarized light (elliptical polarized light including circularly polarized light). In addition to the light source that emits non-polarized light, such as a metal halide lamp or a mercury lamp, a light source that emits linearly polarized light or elliptically polarized light can also be used as the light source unit 22. In this case, the polarizer 26 can be omitted.

  In the present embodiment, the quarter wavelength plate 33 is disposed on the optical path of the light reflected by the light receiving side concave mirror 31 of the light receiving system 30, but is not limited to this arrangement. For example, the quarter wavelength plate 33 may be disposed in the illumination system 20. Specifically, in the illumination system 20, the light from the light guide fiber 24 may be disposed on the optical path of the light that has passed through the polarizer 26. In this case, it is arranged on the optical path between the polarizer 26 and the illumination-side concave mirror 25.

  Further, as shown in FIG. 12, a semiconductor device (not shown) includes a design process (step 221) for designing the function and performance of the device, and a mask manufacturing process (mask) for manufacturing a mask (reticle) based on the design process (step 221). Step 222), a substrate manufacturing process (Step 223) for manufacturing a wafer substrate from a silicon material or the like, a substrate processing process (Step 224) for forming a pattern on the wafer by the device manufacturing system DMS or a pattern forming method using the same. It is manufactured through an assembly process (step 225) including a dicing process for assembling a device, a bonding process, a packaging process, and the like, and an inspection process (step 226) for inspecting the device. In the substrate processing step (step 224), a process of applying a resist to the wafer by the coater / developer 95, an exposure process of exposing the mask pattern onto the wafer by the exposure apparatus 100, and a development process of developing the wafer by the coater / developer 95 And an inspection process for evaluating the film thickness, exposure conditions and the like using light from the wafer by the evaluation apparatus 1.

In such a device manufacturing method, the film thickness and the exposure condition are evaluated using the evaluation apparatus 1 described above, and the film thickness condition and / or the exposure condition are corrected based on the evaluation result, for example. The yield of the semiconductor manufactured can be improved.
In the device manufacturing method of the present embodiment, the method of manufacturing a semiconductor device has been particularly described. However, the device manufacturing method of the present embodiment can be applied to a semiconductor material such as a liquid crystal panel or a magnetic disk in addition to a device using a semiconductor material. The present invention can also be applied to the manufacture of devices using other materials.

  Note that the requirements of the above-described embodiments can be combined as appropriate. Some components may not be used. In addition, as long as it is permitted by law, the disclosure of all published publications and US patents related to the inspection devices and inspection methods cited in the above embodiments and modifications are incorporated herein by reference.

  DESCRIPTION OF SYMBOLS 1 ... Evaluation apparatus, 5 ... Stage, 10 ... Wafer, 10a ... Conditional wafer, 20 ... Illumination system, 30 ... Light receiving system, 35 ... Imaging part, 40 ... Image processing part, 50 ... Calculation part, 60 ... Inspection part, 85 ... Storage unit, 95 ... Coater / developer, 100 ... Exposure device

Claims (19)

An illumination unit that illuminates polarized light on the surface of the test substrate on which the test pattern is formed;
A detector that receives light reflected from the surface by illumination of the illuminator and detects a condition that defines a polarization state of the light;
Based on the data indicating the relationship between the film thickness condition and the exposure condition when forming the predetermined pattern and the condition defining the polarization state, and the condition defining the polarization state of the light reflected from the surface, the test pattern An arithmetic unit that evaluates at least one of a film thickness condition when forming the test pattern and an exposure condition when forming the test pattern;
An evaluation apparatus comprising: The condition that defines the state of polarization includes a plurality of defining conditions,
2. The data according to claim 1, wherein the data indicates a relationship between the film thickness condition and the exposure condition, and a prescribed condition in which a change in the other is larger with respect to one change in the change in the film thickness condition and the exposure condition. Evaluation device. The computing unit is
The data for evaluating at least one of the film thickness condition and the exposure condition when the test pattern is formed on the surface, the pattern was formed under the known film thickness condition and the known exposure condition. The evaluation apparatus according to claim 1, wherein the evaluation apparatus is obtained based on a condition that defines a polarization state of light emitted from the surface of the substrate. The conditions defining the state of polarization include a first defining condition and a second defining condition,
The computing unit is
The evaluation apparatus according to claim 3, wherein the data is obtained based on changes in the first prescribed condition and the second prescribed condition with respect to changes in the film thickness condition and the exposure condition when forming the predetermined pattern.   The evaluation apparatus according to claim 1, further comprising a storage unit that stores the data. The test pattern formed on the surface is formed through a lithography process including thin film formation by a thin film forming apparatus and exposure by an exposure apparatus,
The film thickness condition includes a thickness of the thin film formed by the thin film forming apparatus, and the exposure condition includes an exposure amount and a focus state of exposure in the exposure apparatus,
The data indicates a relationship between the film thickness condition, the exposure amount, the focus state, and a condition that defines the polarization state.
The arithmetic unit determines at least one of the film thickness condition, the exposure amount, and the focus state when the test pattern is formed based on a condition that defines a polarization state of light reflected from the surface. The evaluation device according to any one of claims 1 to 5 to be evaluated. The thin film forming apparatus includes a photosensitive film forming apparatus that forms a photosensitive film on the substrate,
The evaluation apparatus according to claim 6, wherein the film thickness condition includes a thickness of the photosensitive film. The illumination unit illuminates the entire surface of the substrate to be tested with the polarized light in a lump.
The evaluation device according to claim 1, wherein the detection unit includes an image sensor that captures an image of the entire surface of the substrate to be tested. The illumination unit illuminates a part of the surface of the test substrate with the polarized light,
The detection unit includes an image sensor that captures an image of a part of the surface of the test substrate;
The evaluation according to any one of claims 1 to 7, further comprising a stage capable of moving the test substrate so that the polarized light from the illumination unit is sequentially irradiated onto the entire surface of the test substrate. apparatus. A coating apparatus for coating a photosensitive film on the surface of the substrate;
An exposure apparatus that exposes a pattern on the surface of the substrate;
An evaluation apparatus according to any one of claims 1 to 9,
An exposure system that adjusts at least one of the coating apparatus and the exposure apparatus according to an evaluation result of the evaluation apparatus. Illuminating polarized light on the surface of the test substrate having a test pattern formed on the surface;
Receiving light reflected from the surface by illumination of the polarized light and detecting a condition that defines a polarization state of the light;
Based on the data indicating the relationship between the film thickness condition and the exposure condition when forming the predetermined pattern and the condition defining the polarization state, and the condition defining the polarization state of the light reflected from the surface, the test pattern Evaluating at least one of the film thickness condition when forming the exposure condition and the exposure condition when forming the test pattern;
Evaluation method including The condition that defines the state of polarization includes a plurality of defining conditions,
The said data shows the relationship between the said film thickness condition and the said exposure condition, and the prescription | regulation conditions from which the other change becomes larger with respect to one change in the change of the said film thickness condition and the said exposure condition. Evaluation method. Evaluating at least one of the film thickness condition when the test pattern is formed and the exposure condition when the test pattern is formed is
The data for evaluating at least one of the film thickness condition and the exposure condition when the test pattern is formed on the surface, the pattern was formed under the known film thickness condition and the known exposure condition. 13. The evaluation method according to claim 11, further comprising: obtaining based on a condition that defines a polarization state of light emitted from the surface of the substrate. The conditions defining the state of polarization include a first defining condition and a second defining condition,
Evaluating at least one of the film thickness condition when the test pattern is formed and the exposure condition when the test pattern is formed is
The evaluation method according to claim 13, further comprising obtaining the data based on changes in the first prescribed condition and the second prescribed condition with respect to changes in the film thickness condition and the exposure condition when forming the predetermined pattern. .   The evaluation method according to claim 11, comprising storing the data. The test pattern formed on the surface is formed through a lithography process including thin film formation by a thin film forming apparatus and exposure by an exposure apparatus,
The film thickness condition includes a thickness of the thin film formed by the thin film forming apparatus, and the exposure condition includes an exposure amount and a focus state of exposure in the exposure apparatus,
The data indicates a relationship between the film thickness condition, the exposure amount, the focus state, and a condition that defines the polarization state.
Evaluating at least one of the film thickness condition when the test pattern is formed and the exposure condition when the test pattern is formed is
Evaluating at least one of the film thickness condition, the exposure amount, and the focus state when the test pattern is formed based on a condition that defines a polarization state of light reflected from the surface. The evaluation method as described in any one of Claims 11-15. The thin film forming apparatus includes a photosensitive film forming apparatus that forms a photosensitive film on the substrate,
The evaluation method according to claim 16, wherein the film thickness condition includes a thickness of the photosensitive film. When illuminating the surface of the test substrate with the polarized light, illuminate the entire surface.
The evaluation method according to any one of claims 11 to 17, wherein when receiving light reflected from the surface of the test substrate, an image of the entire surface is picked up. Applying a photosensitive film to the surface of the substrate;
Exposing the pattern to the surface of the substrate;
Evaluating at least one of a film thickness condition and an exposure condition when the pattern is formed using the evaluation method according to any one of claims 11 to 18,
A semiconductor device manufacturing method for correcting at least one of a film thickness condition of the photosensitive film on the substrate and an exposure condition of the pattern according to an evaluation result of the evaluation method.

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