JP2012149983A - Displacement detecting deice, exposure device, and device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the displacement amount of a surface to be inspected by minimizing an influence of a swell.SOLUTION: An object lens 18 projects a light flux emitted by a light source 13 on a surface 23a to be inspected as minute beam light. A cylindrical lens 21 gives astigmatism to a reflection light flux reflected by the surface 23a to be inspected. A light-receiving sensor 19 has a light-receiving surface which is divided into plural pieces so as to make the reflection light flux to which the astigmatism is given incident and obtain output change according to a light-receiving pattern. A signal processing portion 26 detects the displacement of the surface 23a to be inspected on the basis of a displacement signal obtained from the light-receiving surface. A surface swell correcting portion 28 obtains a cycle pitch of a swell on a surface on the basis of the displacement signal, changes an interval between a condenser lens 20 and the light-receiving surface 19a so as to make a beam diameter on the surface 23a to be inspected at that time larger than the cycle pitch, and moves the object lens 18 while interlocking the change.

Description

  The present invention relates to a displacement detection apparatus that detects a displacement between an objective lens and a test surface using an optical astigmatism method, an exposure apparatus using the same, and a device manufacturing method using the exposure apparatus. is there.

  Conventionally, a light beam emitted from a light source is projected as a minute beam onto a test surface by an objective lens, and astigmatism is given to the reflected light from the test surface by an astigmatism optical member. A displacement detection device that detects a displacement of a surface position of a test surface (a position along a normal direction of the test surface) with respect to an objective lens based on a light beam is known (Patent Document 1). In this displacement detection device, a reflected light beam reflected from the surface to be measured is received by a four-divided sensor. The quadrant sensor generates a differential signal (displacement signal) value based on an output signal obtained from the quadrant sensor using the astigmatism method, and converts the differential signal value into a displacement amount of the test surface and outputs it. To do.

  By the way, an optical displacement measuring device using a diffraction grating (grating) is known as a device for detecting a relative movement position of a movable part such as a machine tool, a semiconductor manufacturing device, or an exposure device. The displacement measuring device generally includes a diffraction grating, a coherent light source, two mirrors, a half mirror, a photodetector, and the like. For example, in the case of an exposure apparatus, the diffraction grating is provided on the surface of a substrate stage that holds a photosensitive substrate such as a wafer. The coherent light source emits laser light that is coherent light. The half mirror divides the laser light emitted from the coherent light source into two beams and irradiates the diffraction grating, and superimposes and interferes the two diffracted lights from the diffraction grating. The two mirrors reflect the diffracted light diffracted by the diffraction grating. The photodetector receives the two interfered diffracted lights and generates an interference signal (Patent Document 2).

JP-A-4-366711 JP 2000-81308 A

  In the displacement detection apparatus described above, it is assumed that the test surface is a flat surface. Therefore, when a minute uneven wave is provided on the test surface, the amount of displacement is detected following this. However, when the undulation of the minute unevenness is not intended, it may be preferable to measure the average value while ignoring the undulation.

  As such a case, it is conceivable to measure the displacement of the surface position of the substrate stage provided with the above-described diffraction grating. Since a diffraction grating for length measurement is engraved on the substrate stage, even when the upper layer is flattened, fine irregularities of a certain period (periodic structure) may remain. Since what is actually desired to be detected is the surface height of the portion where the diffraction grating is not engraved, it is preferable to ignore the waviness of the unevenness. The influence on the amount of displacement becomes a problem when the diameter of the minute beam that irradiates the surface to be examined is not sufficiently large with respect to the periodic pitch of the undulations on the surface.

  The present invention has been made in view of the above circumstances, and when there is a undulation peculiar to the test surface, a displacement detection device devised so as to detect the displacement amount of the test surface while minimizing the influence of the swell, exposure An object is to provide an apparatus and a device manufacturing method.

  One aspect of the displacement detection apparatus illustrating the present invention is as follows: a light source, an objective lens that projects a light beam emitted from the light source as a minute beam on the surface to be tested, and an astigmatism to the reflected light beam reflected by the surface to be tested An astigmatism optical member, a condensing lens for condensing the reflected light beam provided with astigmatism, and a plurality of light receiving surfaces so that the reflected light beam that has been collected is incident and an output change according to the light receiving pattern is obtained. A light receiving sensor divided into two, a signal processing means for detecting a displacement amount of the test surface based on a displacement signal obtained from the light receiving surface, and a fine unevenness of the test surface in which the diameter of the micro beam is obtained based on the displacement amount. Surface waviness correcting means for relatively moving the condensing lens and the light receiving surface along the optical axis incident on the light receiving surface so as to be larger than the periodic pitch of the waviness is provided.

  According to the displacement detection apparatus of the present invention, the distance between the condensing lens and the light receiving surface is changed so that the diameter of the minute beam irradiated on the test surface is larger than the periodic pitch of the undulations of the unevenness of the test surface. Therefore, it is possible to detect a displacement amount in which the influence of the undulation on the test surface is reduced as much as possible.

It is a perspective view which shows the outline of the displacement detection apparatus of this embodiment. It is explanatory drawing which shows the spot light which injects into a light receiving sensor when the distance between an objective lens and a to-be-tested surface corresponds with the focal distance of an objective lens. It is explanatory drawing which shows the spot light which injects into a light receiving sensor when the distance of an objective lens and a to-be-tested surface turns into a distance exceeding the focal distance of an objective lens. It is explanatory drawing which shows the spot light which injects into a light receiving sensor when the distance of an objective lens and a to-be-tested surface turns into a distance less than the focal distance of an objective lens. It is a graph which shows the characteristic of the displacement signal obtained from a light-receiving sensor, and the displacement amount of a to-be-tested surface. It is a block diagram which shows the structure of a surface waviness correction | amendment part. It is explanatory drawing which shows the outline of the exposure apparatus using the displacement detection apparatus of this embodiment. It is a top view which shows the substrate stage of exposure apparatus. It is a flowchart explaining the operation | movement procedure of the displacement detection apparatus of this embodiment. It is a graph which shows the relationship between the variation | change_quantity of the ratio of the part higher than the average of the height of a wave | undulation, and the ratio of the period pitch of a wave | undulation, and a beam radius. It is a flowchart which shows the procedure of the manufacturing process of a semiconductor device. It is a flowchart which shows the procedure of the manufacturing process of liquid crystal devices, such as a liquid crystal display element.

  As shown in FIG. 1, the displacement detection apparatus 10 according to the present embodiment includes a non-contact sensor unit 11 and a detection unit 12. The non-contact sensor unit 11 includes a light source 13, a collimating lens 14, a light adjusting member 15, a polarizing beam splitter 16, a λ / 4 plate 17, an objective lens 18, a light receiving sensor 19, a condensing lens 20, a cylindrical lens 21, and a light receiving sensor movement. The mechanism 24, the objective lens moving mechanism 25, and the like are configured to detect the test surface 23a of the test object 23 in a non-contact manner.

  The detection unit 12 includes a signal processing unit 26, a surface waviness correction unit 28, and a display unit 27, and detects the displacement amount of the test surface 23 a based on the displacement signal obtained from the non-contact sensor unit 11.

  The light source 13 emits laser light emitted from, for example, a semiconductor laser diode, a super luminescence diode, or a light emitting diode toward the collimator lens 14. The collimating lens 14 converts the emitted light L emitted from the light source 13 into parallel light. The outgoing light L converted into parallel light is incident on the light adjusting member 15.

  The light adjusting member 15 is disposed on the optical path between the collimating lens 14 and the polarization beam splitter 16, and the beam diameter of the emitted light L imaged on the test surface 23 a is set as compared with the case without the light adjusting member 15. While expanding, the resolution of the emitted light L is lowered.

  The light adjusting member 15 is disposed around the circular light shielding portion 33 by forming a metal layer on the circular glass substrate 22 and patterning the formed metal layer into a predetermined shape by photolithography or the like. And an annular transmission part 34. The light shielding unit 33 shields the paraxial light beam of the emitted light L. The transmission part 34 allows the emitted light L to pass toward the test surface 23a. By adjusting the opening diameter of the transmission part 34, it is possible to adjust the passing light amount of the parallel light emitted from the collimating lens 14.

  Outgoing light L that has passed through the collimating lens 14 and entered the light adjusting member 15 is such that the paraxial ray (first outgoing light) of the outgoing light L is shielded by the light-shielding portion 33, and ambient light around the paraxial ray. (Second outgoing light) passes through the glass substrate 22 via the transmission part 34.

  The polarization beam splitter 16 transmits the outgoing light L that has passed through the light adjustment member 15 and makes it incident on the λ / 4 plate 17. The λ / 4 plate 17 converts outgoing light L, which is incident linearly polarized light, into right-handed circularly polarized light. The outgoing light L that has passed through the λ / 4 plate 17 is incident on the objective lens 18.

  The objective lens 18 is an optical element including a lens having a predetermined numerical aperture, and is movable along the optical axis of the emitted light L by the objective lens moving mechanism 25. It is set at a predetermined position separated by a distance close to the focal length. The outgoing light L incident on the objective lens 18 is condensed on the surface 23a to be measured with a predetermined beam diameter. The emitted light L collected on the test surface 23a is reflected by the test surface 23a. The reflected light Lr reflected by the test surface 23 a passes through the objective lens 18 and enters the λ / 4 plate 17.

  The λ / 4 plate 17 further rotates the incident reflected light, which is polarized light rightward, to the right, and converts it into reflected light Lr composed of linearly polarized light whose polarization direction is orthogonal to the outgoing light L. The reflected light Lr that has passed through the λ / 4 plate 17 enters the polarization beam splitter 16 again.

  The polarization beam splitter 16 transmits the reflected light Lr toward the condenser lens 20 because the incident reflected light Lr has a polarization direction orthogonal to the outgoing light L.

  The condenser lens 20 is an optical element including a lens having a predetermined numerical aperture, and condenses incident reflected light Lr on the cylindrical lens 21 with a predetermined beam diameter. The cylindrical lens 21 gives astigmatism to the collected reflected light Lr and focuses it on the light receiving sensor 19.

  The light receiving sensor 19 is movable along the optical axis of the reflected light Lr by the light receiving sensor moving mechanism 24, and generates a displacement signal (displacement information) based on the reflected light Lr collected by the cylindrical lens 21. Output. The light receiving sensor 19 is composed of a photodiode divided into four.

  As shown in FIG. 2, the four-divided diodes A to D have a configuration in which a square is divided into four, and each detects the amount of light. The beam diameter of the reflected light Lr collected on the four-divided diodes A to D becomes a light spot as shown in FIG. 2 when the test surface 23a is at the focal length f1 of the objective lens 18. Further, when the objective lens 18 moves away from the test surface 23a from the focal length f1, as shown in FIG. 3, it becomes an elliptical light spot spreading laterally, and when the objective lens 18 is closer than the focal length f1, FIG. As shown in Fig. 2, the light spot becomes an elliptical light beam extending vertically.

  Here, when the output signals corresponding to the light amounts output from the diodes A to D are a, b, c, and d, the displacement signal S representing the deviation of the focal length f1 is, for example, as shown in [Equation 1]. It can be obtained using a standardized expression.

[Equation 1]
S = [(a + d)-(b + c)] / (a + b + c + d)
At this time, the displacement signal S and the displacement amount obtained from the equation [Equation 1] have characteristics as shown in the graph of FIG. The displacement amount “0” shown in FIG. 5 represents the reference surface of the test surface 23a when the distance to the objective lens 18 is equal to the focal length f1 of the objective lens 18.

  The signal processing unit 26 obtains the displacement of the test surface 23a as a displacement amount from the reference surface based on the displacement signal S calculated using the equation [Equation 1]. At this time, the displacement amount of the test surface 23a is converted from the displacement signal S based on the astigmatism amount given at that time.

  The signal processing unit 26 performs predetermined image signal processing, generates an image signal based on the converted displacement amount, and outputs the image signal to the display unit 27. The display unit 27 is composed of, for example, an LCD, and performs display based on the image signal output from the signal processing unit 26, and displays the displacement of the test surface 23a on the screen.

  As illustrated in FIG. 6, the surface waviness correction unit 28 includes a surface waviness determination unit 29, a beam diameter determination unit 30, an interval determination unit 31, and a focus position correction unit 32. The surface undulation determining unit 29 determines whether or not there is a fine undulation characteristic on the test surface 23a based on the amount of displacement. If it is determined that there is, the beam diameter determining unit 30 obtains the periodic pitch of the undulation of the test surface 23a, and compares the value of the beam diameter and the periodic pitch irradiated to the test surface 23a at that time. It is determined whether or not the beam diameter value is larger than the periodic pitch value. When the value of the beam diameter is equal to or less than the value of the periodic pitch, the interval determining unit 31 obtains the interval between the condenser lens 20 and the light receiving surface 19a so that the value of the beam diameter exceeds the value of the periodic pitch. The light-receiving sensor 19 is moved by controlling the light-receiving sensor moving mechanism 24 so that the interval is reached. When the beam diameter value exceeds the periodic pitch value, the interval is not changed.

  When the light receiving surface 19a of the light receiving sensor 19 is moved, the focus position of the objective lens 18 is shifted. For this reason, the focus position correction unit 32 controls the objective lens moving mechanism 25 so as to correct the focus position of the objective lens 18 according to the interval determined by the interval determination unit 31. Note that the cylindrical lens 21 may be disposed between the condenser lens 20 and the polarization beam splitter 16.

  Such a displacement detection apparatus 10 is used as an inclination detection means for correcting the inclination of the substrate stage 41 in the exposure apparatus 40 shown in FIG. As is well known, the exposure apparatus 40 illuminates a mask 43 on which a pattern is formed by light emitted from a light source provided in the illumination unit 42, and a resist is applied to the pattern image of the mask 43 by the projection optical unit 44. The image is transferred onto a plurality of unit exposure areas set vertically and horizontally on a wafer (photosensitive substrate) 45.

  The wafer 45 is held on the substrate stage 41. The substrate stage 41 is provided on the XY table 46. The XY table 46 moves the wafer 45 in the X and Y directions by driving an XY table driving mechanism 47.

  The control unit 48 comprehensively controls the illumination unit 42, the XY table drive mechanism 47, and the like. In the exposure, the unit exposure area on the wafer 45 is positioned at the exposure position by moving the XY table 46 along the XY plane, and the pattern image of the mask 43 is exposed to the unit exposure area. By repeating the operation described above, the pattern image of the mask 43 is exposed to all unit exposure areas.

  As shown in detail in FIG. 8, the plurality of displacement detection devices 10 are, for example, 3 to 5 spots at a plurality of measurement positions set outside the region holding the wafer 45 on the surface of the reference stage 41. The amount of displacement of the surface of the reference stage 41 is measured by irradiating light 49 to 54. In addition, the code | symbol 55 shown in the figure is a unit exposure area | region.

  During the exposure, the control unit 48 operates the plurality of displacement detection devices 10 to detect the displacement of the surface of the reference stage 41. The reference stage 41 moves in the X and Y directions together with the movement of the XY table 46 to change the measurement positions of the plurality of displacement detection devices 10. The displacement amount obtained from each displacement detection device 10 is continuously sent to the control unit 48.

  The control unit 48 obtains the inclination of the reference stage 41 based on the displacement amount obtained from each displacement detection device 10, and changes the pressing amounts of the plurality of pressing means 57 and 58 via the driver 56 so as to correct the inclination. Thus, the inclination of the reference stage 41 is corrected to be horizontal.

  Here, FIG. 9 shows an operation procedure when the displacement detection apparatus 10 of the present embodiment is used. First, the interval determination unit 31 sets the light receiving sensor 19 at a predetermined initial position (S-1). Thereafter, the in-focus position correcting unit 32 moves the objective lens 18 to the vicinity of the in-focus position where the amount of displacement becomes substantially zero at that time (S-2). As a result, the spot light imaged by the objective lens 18 is in the vicinity of the test surface 23a, and the light enters the light receiving surface 19a substantially evenly.

  Thereafter, the controller 48 of the exposure apparatus 40 pre-measures the displacement amount of the surface (test surface) of the reference stage 41 by preliminarily step-driving the XY table 46 in the X and Y directions (pre-scan). (S-3).

  The signal processing unit 26 sends the displacement signal S obtained by the pre-scan to the beam diameter determining unit 30. The surface waviness determination unit 29 includes a known discrete Fourier transform processing unit, filter processing unit, and inverse discrete Fourier transform processing unit (all not shown).

  The discrete Fourier transform processing unit performs discrete Fourier transform on the displacement signal and calculates displacement amount data in the spatial frequency domain. The filter processing unit extracts a high frequency component equal to or greater than a predetermined value from the spatial frequency domain displacement data using a high pass filter. The inverse discrete Fourier transform processing unit performs inverse discrete Fourier transform on the filtered spatial frequency domain displacement amount data to convert it into real space displacement amount data.

  As described above, the surface undulation determining unit 29 performs a process of extracting a high frequency component on the displacement amount data in the spatial frequency region, thereby providing a continuous or dominant period on the unevenness of the test surface 23a. It can be determined whether there is a undulation (S-4).

  If it is determined that there is a wave, the beam diameter determining unit 30 selects a period of the period or a dominant period and calculates a period pitch in the range (S-5).

  The interval determination unit 31 compares the calculated periodic pitch with the beam diameter at that time (S-6). If the beam diameter exceeds the periodic pitch value, the light receiving sensor 19 is not moved. If the beam diameter value is equal to or smaller than the periodic pitch value, the interval between the condenser lens 20 and the light receiving sensor 19 is determined so as to be, for example, approximately 10 times the periodic pitch (S-7). The light receiving sensor moving mechanism 24 is controlled to move the light receiving sensor 19 to a position corresponding to the interval (S-8).

  In conjunction with the movement of the light receiving sensor 19, the in-focus position correction unit 32 moves the objective lens 18 to the in-focus position where the amount of displacement is zero (S-9).

  Thus, each displacement detection device 10 sets the light receiving surface 19a at a position where the beam diameter on the surface 23a to be measured is sufficiently larger than the periodic pitch by performing pre-measurement in advance. Thereafter, the control unit 48 starts the above-described exposure operation, and operates the plurality of displacement detection devices 10 during the exposure to start tilt correction of the reference stage 41 (S-10).

  In the above embodiment, only the light receiving sensor 19 is moved, but the condenser lens 20 may be moved, or both the light receiving sensor 19 and the condenser lens 20 may be moved.

  In each of the above embodiments, the light receiving sensor 19 is moved by performing pre-detection. However, the present invention is not limited to this, and the position of the light receiving sensor 19 is moved according to the waviness period during exposure. You may comprise. In this case, monitoring means for monitoring the presence or absence of swell may be provided.

  By the way, when the objective lens 18 is moved, the position conjugate with the light source 13 is shifted from the test surface 23a, so that the beam diameter spreads on the test surface 23a. In such a state, the spread of the beam diameter can be freely controlled by configuring so that the interval between the condenser lens 20 and the light receiving surface 19a can be freely changed.

  In general, if the beam diameter is widened on the test surface 23a, vignetting of the light flux occurs or the focus fluctuation amount and the signal amount from the light receiving sensor 19 change, which is not preferable. However, in the case where there are undulations of fine irregularities on the surface 23a to be measured, if the beam diameter is sufficiently larger than the periodic pitch of the undulations, it is possible to expect an effect that the influence is canceled and disappears. Therefore, when there is a characteristic period waviness on the test surface 23a, normal measurement is performed in advance to measure the period pitch of the waviness in the test surface 23a, and then the condenser lens 20 and the light receiving surface are measured. Although the measurement accuracy is somewhat lowered by changing the distance to the surface 19a so that the beam diameter on the test surface 23a is sufficiently larger than the periodic pitch of the undulation, the influence of the undulation is reduced. High precision measurement and control of the surface position using the output.

  In the above embodiment, when the beam diameter is smaller than the periodic pitch of the undulation, the interval between the condensing lens 20 and the light receiving sensor 19 is determined so as to be, for example, approximately 10 times or more of the periodic pitch. But it is not limited to this.

  As described above, when waviness exists on the test surface 23a, the measurement value changes due to the actual height difference of the test surface 23a due to the waviness and the fluctuation of the focal position due to the curvature of the test surface 23a. This effect becomes prominent when the beam diameter formed on the test surface 23a is not sufficiently large with respect to the periodic pitch of the waviness.

  In order to show this phenomenon, it is assumed that a portion having a height higher than the average and a portion having a lower height than the average have waviness in a striped pattern with a duty ratio of 1: 1. This corresponds to a striped rectangular groove structure. When the ratio of the portion where the height of the test surface 23a is higher than the average in the region included in the light beam with such a periodic structure is calculated, the result is as shown in FIG. In FIG. 10, the horizontal axis indicates the ratio between the waviness period pitch and the beam radius, and the vertical axis indicates the amount of change in the ratio. For example, when the fluctuation amount is 0.1, it means that the ratio of the position higher than the average in the irradiation area fluctuates within a range of 50 ± 10% when the beam is scanned. Since the value actually detected depends on the waviness shape, this value does not correspond to the waviness of the detected value on a one-to-one basis, but can be used as a guide for fluctuations in the detected value.

  It can be seen from FIG. 10 that the beam radius should be approximately four times the periodic pitch or less in order to make the ratio fluctuation amount 0.05 or less. Even when assuming a rectangular groove structure with the most severe height difference, if the fluctuation is 0.05 or less, the ratio of the crest portion in the beam is limited to the range of 45 to 55%, so the height difference in the detected value is It can be expected that the actual reduction is about 10% or less. Furthermore, if the beam radius is set to approximately 15 times or more of the periodic pitch, the fluctuation is 0.01 or less, the detected swell is about 2% or less of the actual, and the influence of the swell is considered to be almost negligible.

  For this reason, during normal use, the beam radius is preferably about 4 times or more of the typical waviness period pitch, and particularly when high accuracy is required, the beam radius is preferably about 15 times or more of the period pitch. . On the other hand, if a slight swell is allowed, the beam radius may be about twice or more the periodic pitch and the variation may be 0.1.

  As described above, the beam radius is set in three ways, with the value of the periodic pitch being 2, 4 and 15 (respectively waviness residual ratios of 20%, 10% and 2% in the rectangular grooves). However, these values are not critical for a particular purpose. In the actual case, there are specifications of the fluctuation amount of the detected value and the amount of undulation of the unevenness of the test surface that actually exists, and these are determined from these relationships.

  Next, a device manufacturing method using the exposure apparatus 40 described in FIG. 7, for example, a semiconductor device manufacturing method will be described with reference to FIG. In the semiconductor device manufacturing process, a metal film is vapor-deposited on the wafer 45 serving as a substrate for the semiconductor device (S-11), and a photoresist, which is a photosensitive material, is applied on the vapor-deposited metal film (S-12). Subsequently, using the exposure apparatus 40 described above, the pattern formed on the mask (reticle) 43 is transferred to each unit exposure region 55 on the wafer 45 (S-13: exposure process), and the wafer 45 after the transfer is completed. Development, that is, development of the photoresist to which the pattern has been transferred (S-14: development step). Thereafter, using the resist pattern generated on the surface of the wafer 45 as a mask, processing such as etching is performed on the surface of the wafer 45 (S-15: processing step).

  Here, the resist pattern is a photoresist layer in which irregularities having a shape corresponding to the pattern transferred by the exposure apparatus 40 described above are generated, and the recess penetrates the photoresist layer. In the processing step, the surface of the wafer 45 is processed through this resist pattern. The processing performed in this step includes, for example, at least one of etching of the surface of the wafer 45 and film formation of a metal film or the like. In the exposure process, the above-described exposure apparatus 40 performs pattern transfer using the wafer 45 coated with the photoresist as a photosensitive substrate.

  A device manufacturing method using the exposure apparatus 40, for example, a method for manufacturing a liquid crystal device such as a liquid crystal display element will be described with reference to FIG. In the liquid crystal device manufacturing process, a pattern forming process (S-16), a color filter forming process (S-17), a cell assembling process (S-18), and a module assembling process (S-19) are sequentially performed.

  In the pattern forming step, a predetermined pattern such as a circuit pattern and an electrode pattern is formed on the glass substrate coated with a photoresist as a photosensitive substrate, using the exposure apparatus 40 described above. In this pattern formation step, an exposure step of transferring the pattern to the photoresist layer using the exposure device 40, and development of the photoresist layer on the glass substrate onto which the pattern has been transferred are performed, and a photoresist having a shape corresponding to the pattern A development step for generating a layer and a processing step for processing the surface of the glass substrate through the developed photoresist layer are included.

  In the color filter forming step, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix, or a filter having three stripes of R, G, and B A color filter is formed by arranging a plurality of sets in the horizontal scanning direction.

  In the cell assembly process, a liquid crystal panel (liquid crystal cell) is assembled using a glass substrate on which a predetermined pattern is formed by the pattern formation process and a color filter formed by the color filter formation process.

  Specifically, for example, a liquid crystal panel is formed by injecting liquid crystal between a glass substrate and a color filter. In the module assembling process, various components such as an electric circuit for performing a display operation of the liquid crystal panel and a backlight are attached to the liquid crystal panel assembled in the cell assembling process.

  The present invention is not limited to application to an exposure apparatus for manufacturing a semiconductor device, for example, an exposure apparatus for a display device such as a liquid crystal display element formed on a square glass plate or a plasma display, or an imaging device. The present invention can be widely applied to an exposure apparatus for manufacturing various devices such as elements (CCD, etc.), micromachines, thin film magnetic heads, and DNA chips. Furthermore, the present invention can also be applied to an exposure process (exposure apparatus) when manufacturing a mask (photomask, reticle, etc.) on which mask patterns of various devices are formed using a photolithography process.

DESCRIPTION OF SYMBOLS 10 Displacement detection apparatus 13 Light source 18 Objective lens 19 Light reception sensor 19a Light reception surface 21 Cylindrical lens 23a Test surface 28 Surface waviness correction | amendment part 40 Exposure apparatus

Claims (7)

A light source;
An objective lens that projects a light beam emitted from a light source onto the surface to be measured as a minute beam;
An astigmatism optical member that gives astigmatism to the reflected light beam reflected by the test surface;
A condensing lens that condenses the reflected light flux provided with astigmatism;
A light receiving sensor that divides the light receiving surface into a plurality of light beams so that the condensed reflected light flux is incident to obtain an output change according to a light receiving pattern;
Signal processing means for detecting a displacement amount of the test surface based on a displacement signal obtained from the light receiving surface;
An optical axis on which the condensing lens and the light receiving surface are incident on the light receiving surface so that the diameter of the minute beam is larger than the periodic pitch of the undulations of the fine irregularities on the surface to be measured determined based on the amount of displacement. Surface waviness correcting means for relatively moving along the surface,
A displacement detection apparatus comprising: The displacement detection apparatus according to claim 1,
The surface waviness correcting means includes objective lens moving means for moving the objective lens to a focusing position where the displacement amount is zero in conjunction with relative movement of the condenser lens and the light receiving surface. A displacement detector characterized by the above. The displacement detection device according to claim 1 or 2,
The surface waviness correcting means includes
A beam diameter determining means for determining a periodic pitch of the undulation of the test surface based on the amount of displacement, and determining a beam diameter irradiated to the test surface so as to be larger than the periodic pitch;
An interval calculating means for calculating an interval between the condenser lens and the light receiving surface based on the determined beam diameter;
The displacement detection apparatus is characterized in that the condenser lens and the light receiving surface are relatively moved so as to have the interval. An exposure apparatus comprising: the displacement detection apparatus according to any one of claims 1 to 3; and a substrate stage that supports a photosensitive substrate on which a predetermined pattern provided on a mask is exposed.
The exposure apparatus according to claim 1, wherein the displacement detection device detects a displacement of a surface position of the surface of the substrate stage. The exposure apparatus according to claim 4, wherein
The displacement detection device is characterized in that the distance between the condenser lens and the light receiving surface is determined in advance by moving the substrate stage in advance to detect the displacement of the surface position of the surface. Exposure equipment to do. The exposure apparatus according to claim 4, wherein
The displacement detection device moves the substrate stage and measures the displacement of the surface position of the surface while exposing the image of the mask pattern on the photosensitive substrate, and detects the displacement between the condenser lens and the light receiving surface. An exposure apparatus characterized by changing the interval. In the device manufacturing method using the exposure apparatus according to any one of claims 4 to 6,
An exposure step of exposing the predetermined pattern to the photosensitive substrate;
Developing the photosensitive substrate to which the predetermined pattern is transferred, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
A processing step of processing the surface of the photosensitive substrate through the mask layer;
A device manufacturing method comprising:

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