JP2005062035A - Method for detecting foreign matter between substrates, near field exposing method, detector of foreign matter between substrates and near field exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for detecting foreign matter between substrates constituted so as to enhance a yield by detecting the foreign matter present between the substrates, and to provide a near field exposing method, a detector of the foreign matter between the substrates and a near field exposure device. <P>SOLUTION: For example, this detection means of the foreign matter between the substrates is adapted to the near field exposing method, which is constituted so as to deform an exposure mask to bring the same into close contact with an object 106 to be treated to perform exposure using the near field bleeding out of the fine opening formed to the exposure mask, or the near field exposure device therefor. This detection means has a means 103 for bringing the exposure mask into close contact with the object to be treated and a means 110 for detecting the deformation of the exposure mask produced by the foreign matter 111 present between the exposure mask and the object to be treated to be bonded to them. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a foreign matter detection method between substrates, a near-field exposure method, a foreign matter detection device between substrates, and a near-field exposure device, for example, generally a photomask or an object to be processed in a manufacturing process such as an integrated circuit or a liquid crystal display (LCD). It is related with the technique for detecting and removing the foreign material adhering to the surface.

Due to the recent demand for smaller and thinner electronic devices, there is an increasing demand for miniaturization of semiconductor elements mounted on electronic devices. For example, the design rule for a mask or reticle pattern is expected to be 130% in line and space (L & S) in a mass production process, and is expected to become smaller in the future. 2. Description of the Related Art In recent years, projection exposure apparatuses that have become mainstream generally include an illumination optical system that illuminates a mask using a light beam emitted from a light source, and a projection optical system that is disposed between the mask and an object to be exposed.
In a projection exposure apparatus, it is generally said that the wavelength of a light source to be used is substantially limited in resolution, and even if an excimer laser is used, it is difficult for the projection exposure apparatus to form a pattern of 0.10 μm or less. In addition, even if there is a light source having a shorter wavelength, the optical material used for the projection optical system (that is, the glass material of the lens) cannot pass through the exposure light having the shorter wavelength (as a result, the exposure target is exposed). There is also a problem that exposure cannot be performed (because it cannot be projected onto an object).

In recent years, an exposure apparatus using the principle of a scanning near field optical microscope (SNOM) has been proposed as a means for enabling fine processing of 0.1 μm or less to deal with such problems. As such an exposure apparatus, for example, in Patent Document 1 or Patent Document 2, a mask that is elastically deformable in the normal direction of the mask surface is brought into close contact with the resist, and a fine aperture pattern having a size of 100 nm or less formed on the mask surface. There has been proposed an apparatus that performs local exposure on an object to be exposed that exceeds the wavelength limit of light using near-field light that oozes out from the light. As a feature of this method, near-field light that oozes out from a minute aperture is localized up to a distance of about the wavelength of the light incident on the aperture, so the distance between the object to be processed and the aperture is preferably less than the wavelength of the light. Needs to be close to a distance of 100 nm or less. For this reason, a mask that can be elastically deformed is used as the exposure mask, and is configured to follow the substrate by bending the exposure mask even when the substrate is wavy.
Japanese Patent Laid-Open No. 11-145051 JP-A-11-184094

  However, when exposure is performed in a state where the elastically deformable mask is not in close contact with the object to be exposed and is separated to a region where no near-field light exists, the object to be exposed has a local area exceeding the wavelength limit of light. Exposure may not be possible. In particular, when a foreign object is caught between the mask and the object to be processed, not only the part where the foreign object 302 exists as shown in FIG. The close contact region 304 exists, and a gap is generated between the photomask 301 and the object to be processed 303 even around the foreign substance 302. As a result, the near-field light 306 does not reach the workpiece 303, and the process proceeds to the next process. Therefore, a pattern cannot be formed, and a defect occurs in the manufactured wafer or glass substrate, resulting in a yield. There was a decrease in

  Therefore, the present invention solves the above problems and detects foreign matter existing between the substrates, thereby improving the yield. The foreign matter detection method between the substrates, the near-field exposure method, and the foreign matter detection between the substrates. An object of the present invention is to provide an apparatus and a near-field exposure apparatus.

The present invention provides a foreign matter detection method between substrates, a near field exposure method, a foreign matter detection device between substrates, and a near field exposure device configured as follows.
That is, in the foreign matter detection method between substrates of the present invention, when a first substrate that is elastically deformable is deformed and brought into close contact with a second substrate that is not elastically deformed, foreign matter existing between these substrates is detected. A method for detecting foreign matter between substrates to be detected, comprising: a step of bringing the first substrate into close contact with the second substrate; and a step of attaching the first substrate to the second substrate between the first substrate and the second substrate. And a step of detecting deformation of the first substrate caused by the adhered foreign matter.
In the foreign matter detection method between substrates according to the present invention, the step of detecting deformation of the first substrate includes the step of irradiating the first substrate and a flat reference surface with light, and the first substrate. And a step of observing interference fringes due to the reflected light from the first substrate reflected from the reference surface and the reflected light from the reference surface reflected from the reference surface.
In the foreign matter detection method between substrates according to the present invention, in the step of irradiating light on the first substrate and a flat reference surface, the first substrate is irradiated with light on the entire surface of the first substrate. It can comprise so that it may irradiate over.
In the foreign matter detection method between substrates according to the present invention, in the step of irradiating light on the first substrate and a flat reference surface, the first substrate is irradiated with light on the entire surface of the first substrate. Can be configured to perform optical scanning.
In the foreign matter detection method between substrates of the present invention, the reference surface can be constituted by the second substrate.
In the foreign matter detection method between substrates according to the present invention, the first substrate is made transparent to the light, and the first substrate and a flat reference surface are irradiated with light on the first substrate side. It can comprise so that it may irradiate from.
In the foreign matter detection method between substrates according to the present invention, the second substrate is transparent to the light, and light irradiation to the first substrate and a flat reference surface is performed on the second substrate side. It can comprise so that it may irradiate from.
Further, in the foreign matter detection method between substrates according to the present invention, the step of observing the interference fringes includes the position, height and size of the foreign matter from the interference fringes, or the first substrate and the second substrate. It can comprise so that the process of calculating the area | region etc. which are spaced apart may be included.
The near-field exposure method of the present invention is a near-field exposure method in which an exposure mask is deformed and brought into close contact with an object to be processed, and exposure is performed using a near-field that oozes out from a minute opening formed in the exposure mask.
When the exposure mask is brought into intimate contact with the object to be processed, the method includes a step of detecting foreign matter existing between the exposure mask and the object to be processed.
In the near-field exposure method of the present invention, the step of detecting the foreign matter can be configured to detect the foreign matter using the foreign matter detection method between the substrates described above.
In the near-field exposure method of the present invention, the step of detecting the foreign matter may be performed by removing the foreign matter based on the detection result of the foreign matter or replacing the exposure mask or the object to be processed with a foreign matter not attached. Can be configured to.
The foreign matter detection device between substrates of the present invention is a foreign matter detection device between substrates for detecting foreign matter existing between a first substrate that can be elastically deformed and a second substrate that is not elastically deformed. Detecting deformation of the first substrate caused by foreign matter adhering to the first substrate and the second substrate, and adhesion means for bringing the first substrate and the second substrate into close contact with each other existing between the first substrate and the second substrate And a shape detecting means.
In the foreign matter detection apparatus between substrates according to the present invention, the shape detection unit includes a light irradiation unit that irradiates light to the first substrate and a flat reference surface, and reflected light that is reflected from the first substrate. And a light receiving element that receives light of interference fringes caused by reflected light reflected from the reference surface.
In the foreign matter detection apparatus between substrates according to the present invention, the shape detection unit includes a light irradiation unit that irradiates light to the first substrate and a flat reference surface, and reflected light that is reflected from the first substrate. A light receiving optical system that receives light of interference fringes caused by reflected light reflected from the reference surface, and a light receiving element that receives light obtained through the light receiving optical system can be used.
In the foreign matter detection apparatus between substrates according to the present invention, the reference plane can be constituted by the second substrate.
The foreign matter detection apparatus between substrates of the present invention is transparent to the light irradiated by the first substrate, and the light irradiation means is a light irradiation means for irradiation from the first substrate. be able to.
The foreign matter detection apparatus between substrates of the present invention is transparent to the light emitted by the second substrate, and the light irradiating means is a light irradiating means for irradiating from the second substrate side. can do.
The foreign matter detection apparatus between substrates according to the present invention calculates a region where the means for obtaining the foreign matter information from the signal from the light receiving element and the first substrate and the second substrate are separated from each other. And a processing apparatus.
Further, the near-field exposure apparatus of the present invention is a near-field exposure apparatus that performs exposure using a near-field that is deformed and brought into close contact with an object to be processed and oozes from a minute opening formed in the exposure mask. It is characterized by having foreign matter detection means for detecting foreign matter existing between the exposure mask and the object to be processed.
In the near-field exposure apparatus of the present invention, the foreign matter detection means can be constituted by the foreign matter detection device between substrates described above.
In the near-field exposure apparatus of the present invention, the foreign substance detecting means removes the foreign substance based on the detection result of the foreign substance, or replaces the exposure mask or the object to be processed with a foreign object not attached. It can be set as the structure which has a detection process means.

  ADVANTAGE OF THE INVENTION According to this invention, the foreign material detection method and foreign material detection apparatus which can detect the foreign material which exists between board | substrates can be provided, and this is applied to a near field exposure, The manufactured wafer, It is possible to realize a near-field exposure method and a near-field exposure apparatus that can prevent defects in the glass substrate and can improve the yield.

[Embodiment 1]
FIG. 1 is a diagram showing a configuration in Embodiment 1 of the present invention, (a) is a diagram showing a configuration of a near-field exposure apparatus to which the above-described foreign matter detection means of the present invention is applied, and (b) is a light receiving element. It is a figure which shows the interference fringe by the intensity distribution of the light irradiated on.
In FIG. 1, reference numeral 101 denotes an exposure mask, which has the same configuration as the exposure mask shown in FIG. That is, in this exposure mask, as shown in FIG. 4, a light shielding layer 402 having a light shielding property for light used for exposure is formed on a mask base material 401 that is transparent to the light used for exposure. In the light shielding layer, a minute opening 403 corresponding to an arbitrary pattern is formed. This exposure mask is composed of a thin film elastic body 404 so as to bend when it comes into contact with a small foreign substance, and this thin film is supported by a support body 405.
In addition, the “back surface” of the exposure mask here is the side facing the pressure control container, and refers to the upper side in FIG. 1, and the “front surface” refers to the opposite side.

The near-field exposure apparatus in FIG. 1 is roughly classified into a pressure adjustment container, a pressure adjustment means, an exposure mask, a light source, a workpiece, a foreign object detection light source, a foreign object detection collimator lens, a half mirror, a reference surface, and a light receiving element. Divided. The exposure mask is arranged with the back surface facing the pressure adjusting device, and is arranged relative to the object to be processed.
The exposure mask 101 is disposed in the pressure adjustment container 103 of the near-field exposure apparatus so that the back surface of the exposure mask 101 faces, and is configured to adjust the deflection of the thin film portion of the mask by pressure adjustment. .
As an object to be processed, a resist 106 is formed on the surface of the substrate 105 (hereinafter referred to as 106 / substrate 105). The resist 106 / substrate 105 is mounted on a stage 118, the stage 118 is driven in the normal direction of the exposure mask 101 surface, and the distance between the front surface of the exposure mask 101 and the resist 106 surface on the substrate 105 extends over the entire surface. Both are brought into close contact with each other so as to be 100 nm or less.

As a close contact method, by applying pressure from the back surface of the exposure mask 101 toward the front surface, the exposure mask 101 is bent due to elastic deformation and pressed against the resist 106 / substrate 105. , It can be adhered over the entire surface.
As an example of a method for applying such pressure, as shown in FIG. 1, the back surface faces the inside of the pressure adjustment container 103 so that the front surface of the exposure mask 101 faces the outside of the pressure adjustment container 103. The high pressure gas is introduced into the pressure regulating container 103 by using the pressure regulating means 117 such as a pump so that the pressure inside the pressure regulating container 103 is higher than the external pressure. As another example, the pressure adjustment container 103 may be filled with a liquid transparent to illumination light, and the pressure of the liquid inside the pressure adjustment container 103 may be adjusted using a cylinder.

  Here, in order to bring the exposure mask 101 and the resist 106 / substrate 105 into close contact with each other, the back surface of the exposure mask 101 is disposed in the pressure adjustment container 103, and the exposure mask is caused by the pressure difference from the lower external pressure than in the pressure adjustment container 103. Although an example in which pressure is applied to the front surface side from the back surface side of 101 is shown, as an opposite configuration, the front surface of the exposure mask and the resist / substrate are arranged in a decompression vessel, Pressure may be applied from the back side of the exposure mask to the front side due to a pressure difference with a higher external pressure. In any case, a pressure difference may be provided so that the pressure on the back surface side is higher than that on the front surface side of the mask.

Next, a foreign object detection method according to the present embodiment will be described.
The exposure mask 101, foreign object detection light source, half mirror, reference surface, and light receiving element in FIG. 1 will be described in detail. In FIG. 1A, foreign matter is sandwiched between the exposure mask and the resist / substrate that is the object to be processed, and the exposure mask that is a thin film is deformed.
FIG. 1B is a view of the intensity distribution of light irradiated on the light receiving element as viewed from the lower side of the drawing, and interference fringes are visible. In FIG. 1, reference numeral 111 denotes a foreign substance sandwiched between the exposure mask and the object to be processed, 107 a foreign substance detection light source, 108 a half mirror, 109 a reference surface, and 110 a light receiving element.

  As shown in FIG. 1, when the foreign substance 111 is put in close contact between the exposure mask 101, which is a thin film, and the resist 106 / substrate 105, which is an object to be processed, the thin film bends and deforms according to the size and shape of the foreign substance. Occurs. Here, the foreign matter detection light PL emitted from the foreign matter detection light source 107 is extended to an area where it is desired to detect the foreign matter through the beam expander 112 or the like. Then, after collimating the light through the collimator lens 113, the light is divided into two by the half mirror 108. One is a thin film portion on the exposure mask 101 where foreign matter is to be detected, and the other is an optically smooth surface. The reference surface 109 is irradiated. Reflected light therefrom is irradiated onto the light receiving element 110 through the half mirror 108, and interference between the reflected lights is observed on the light receiving element 110. That is, it has the same configuration as the Twiman Green interferometer.

  Since the region where the exposure mask 101 and the resist 106 / substrate 105 are blocked from being adhered by the foreign substance 111 is bent without contacting the substrate, the optical path difference from the reference surface 109 changes, and the light receiving element. Interference fringes (FIG. 1B) centering on foreign matter are observed on 110. From the interference fringes, the position and height of the foreign matter, and the non-contact region where the thin film and the substrate are not in close contact can be estimated. From the signal detected by the light receiving element 110, the position, height, and non-contact area of the foreign matter are calculated, and if the foreign matter affects the exposure, the foreign matter is removed, or the object to be processed or the exposure mask is used. Replace with a new one and proceed.

Next, after the foreign object detection processing is performed as described above, in the present embodiment, exposure with near-field light is performed as follows.
First, the half mirror 108 and the light receiving element 110 used for detecting foreign matter are moved to a position where the exposure light is not blocked by an actuator (not shown).
Next, the exposure process is performed. In FIG. 1, the exposure light EL emitted from the exposure light source 115 is collimated by the collimator lens 114, then introduced through the glass window 116 and introduced into the pressure adjustment container 103, and the back surface (in FIG. 1) The resist is exposed with near-field light that irradiates from the upper side) and exudes from a fine aperture pattern formed in the metal thin film 102 on the mask base material 104 on the front surface of the exposure mask 101.
By adopting the above-described configuration, it is possible to detect foreign matter existing between the thin-film exposure mask and the object to be processed, and as a result, there are fewer defects in the manufactured wafer or glass substrate and the yield is reduced. I was able to improve.

[Embodiment 2]
FIG. 2 is a diagram showing a configuration of a near-field exposure apparatus according to Embodiment 2 to which the above-described foreign matter detection means of the present invention is applied.
As in the first embodiment, this is a form of foreign matter detection in which foreign matter existing between an exposure mask that is a thin film and an object to be processed is detected by deformation of the thin film. The method for detecting the deformation of the thin film is basically the same as in the first embodiment. Differences from the first embodiment will be described below.
In the first embodiment, the foreign matter detection light is irradiated at once to the entire area where foreign matter is to be detected. In contrast, in the present embodiment, as shown in FIG. 2, the half mirror is two-dimensionally formed by the deflecting elements 211 and 212 that can deflect the light emitted from the light source such as a galvano mirror. By scanning the through-exposure mask 201, light is irradiated two-dimensionally on a region where foreign matter is to be detected. Reflected light from the exposure mask 201 and the reference surface 209 is detected by the light receiving element 210. At this time, in synchronism with the foreign matter detection light PL that scans on the exposure mask 201, the intensity of the light that is reflected from the exposure mask 201 that reaches the light receiving element 210 and the reflected light from the reference surface 209 is detected. Interference fringes can be detected from the position irradiated with light and the light intensity detected at that time. From the interference fringes, the position and height of the foreign matter, and the non-contact region where the thin film and the substrate are not in close contact can be estimated.
By adopting the above-described configuration, the foreign matter existing between the thin film exposure mask and the object to be processed can be detected. As a result, defects such as manufactured wafers and glass substrates were reduced, and the yield could be improved.

[Embodiment 3]
Next, a foreign object detection method according to Embodiment 3 of the present invention will be described with reference to FIGS.
FIG. 6 is a drawing that best represents the features of the present embodiment, in which 601 is a pseudo mask, 602 is an object to be inspected, and 603 is between the pseudo mask and the object to be processed. A foreign substance 604 is an area where the pseudo mask and the object to be processed are not in close contact.
The details of the pseudo mask are shown in FIG. In the figure, 501 is a pseudo mask transparent to illumination light, 502 is a support for supporting the pseudo mask, and 503 is a thin film portion in which the pseudo mask is a thin film.
FIG. 6A is a cross-sectional view of a state in which the foreign material 603 is sandwiched between the pseudo mask 601 and the object to be processed 602, and FIG. 6B is a view seen from the back side of the pseudo mask 601. Here, the front surface of the pseudo mask refers to the front surface that is in close contact with the object to be processed 602, and the reverse is the rear surface. Here, the pseudo mask is a mask in which a photomask is usually provided with a light shielding layer such as metal for shielding light, but is not provided with a light shielding layer for the purpose of observation from the back side. Say. Further, the pseudo mask is formed of a thin film elastic body so as to bend when it comes into contact with a small foreign matter.

As shown in FIG. 6, when the foreign substance is adhered between the pseudo mask and the object to be processed, the pseudo mask 601 is bent to form a non-contact area 604 centering on the foreign substance. When this non-contact region 604 is irradiated with light of a certain wavelength λ, interference fringes 605 appear around the foreign material 603 as seen from the back side of the pseudo mask as shown in FIG. 6B.
This is because the light reflected from the surface of the pseudo mask and the surface of the object to be processed interferes, and the gap between the surface of the pseudo mask and the surface of the object to be processed becomes “nλ / 2 (n is an integer)”. This occurs because light is strengthened at the part and weakened at the part where “(2n + 1) λ / 4”. That is, the interference fringe 605 can estimate the location where the foreign matter 603 exists, the height (size) of the foreign matter, and the width of the non-contact region 604.
Foreign matter information (position, height, non-contact region, etc.) is stored from the interference fringe 605, the pseudo mask 601 is moved to the object to be processed 602 at a different location, and is again brought into close contact with the object to be processed 602. The information of the foreign object 603 is read. By repeating this operation and comparing the position and size of the stored foreign matter 603, the foreign matter adhering to the pseudo mask 601 and the foreign matter 603 adhering to the object to be processed 602 can be selected. Information about the foreign matter 603 adhering to the surface is obtained.

Here, a pseudo mask 601 without a light shielding layer is used for observation from the back side of the mask, but the object 602 in FIG. 6 is changed to a transparent substrate 703 as shown in FIG. Thus, it is possible to detect foreign matter adhering to a normal exposure mask 705 provided with a light shielding film.
The exposure mask here has the same configuration as the exposure mask shown in FIG. 4 as described in Embodiment 1, and as shown in FIG. 4, a mask base material 401 that is transparent to the light used for exposure. Further, a light shielding layer 402 having a light shielding property to light used for exposure is formed, and a minute opening 403 corresponding to an arbitrary pattern is formed in the light shielding layer. Similar to the above-described pseudo mask, the exposure mask is also composed of a thin-film elastic body 404 so as to bend when it comes into contact with a small foreign matter. This thin film is supported by a support 405.

In FIG. 7, when the light shielding layer 701 on the exposure mask 705 is brought into close contact with the transparent substrate 703 and the foreign substance 704 is sandwiched therebetween, a non-contact region 706 is formed in the same manner as described above. The interference fringes 707 can be observed by irradiating light with a wavelength λ in that region and observing from the transparent substrate 703 side. By similarly observing the interference fringes 707 at a plurality of locations on the transparent substrate 703, the foreign matter adhering to the exposure mask 705 and the foreign matter adhering to the transparent substrate 703 are selected and attached to the exposure mask 705. It is possible to obtain information about the foreign matter that is present.
With the configuration described above, it is possible to detect foreign substances between the pseudo mask and the object to be processed and between the mask and the transparent substrate. By performing both detections on different objects to be processed or transparent substrates, it is possible to detect the number, position, height, and non-contact area of the foreign objects attached to the object to be processed and the mask.
[Embodiment 4]
Embodiment 4 in which the above-described foreign matter detection method of the present invention is incorporated in an exposure apparatus using near-field light will be described with reference to FIG.
An exposure mask 801 in FIG. 8 is an exposure mask having the same configuration as the exposure mask shown in FIG. The pseudo mask 802 is a pseudo mask having the same configuration as the pseudo mask shown in FIG. The “back surface” of the exposure mask and the pseudo mask here refers to the side where the support is present with respect to the thin film, and the “front surface” refers to the opposite side.
The exposure mask 801 and the pseudo mask 802 are arranged in pressure adjusting containers 803 and 804 of the two near-field exposure apparatuses so that the back surfaces of the exposure mask 801 and the pseudo mask 802 face each other, and pressure adjustment is performed. Adjust the deflection of the thin film part.

The near-field exposure apparatus in FIG. 8 is roughly classified into a pressure adjustment container, a pressure adjustment means, a pseudo mask, an exposure mask, a light source, an object to be processed, a transparent substrate, a light receiving optical system, and a light receiving element. The exposure mask and the pseudo mask are arranged facing the back surface of the pressure adjusting device, and are arranged so as to be opposed to the transparent substrate and the object to be processed.
As an object to be processed, a resist 806 is formed on the surface of a substrate 805. A resist 806 / substrate 805 is mounted on the stage 815, the stage 815 is driven in the normal direction of the pseudo mask 802, and the distance between the front surface of the pseudo mask 802 and the resist 806 surface on the substrate 805 is 100 nm or less over the entire surface. The two are brought into close contact with each other.
As a close contact method, by applying pressure from the back surface of the pseudo mask 802 toward the front surface, the pseudo mask 802 is caused to bend due to elastic deformation and pressed against the resist 806 / substrate 805. , It can be adhered over the entire surface.

  As an example of a method for applying such pressure, as shown in FIG. 8, the back surface faces the inside of the pressure regulation container 803 so that the front surface of the pseudo mask 802 faces the outside of the pressure regulation container 803. The high pressure gas is introduced into the pressure regulating container 803 by using the pressure regulating means 809 such as a pump so that the pressure regulating container 803 has a pressure higher than the external pressure. As another example, the inside of the pressure adjustment container 803 may be filled with a liquid transparent to illumination light, and the pressure of the liquid inside the pressure adjustment container 803 may be adjusted using a cylinder.

  Here, in order to bring the pseudo mask 802 and the resist 806 / substrate 805 into close contact with each other, the back surface of the pseudo mask is disposed in the pressure adjustment container 803, and the pseudo mask 802 is caused by a pressure difference with the external pressure lower than that in the pressure adjustment container 803. Although an example is shown in which pressure is applied from the back side to the front side, as a reverse configuration, the front side of the pseudo mask and the resist / substrate are placed in a vacuum container, Pressure may be applied from the back surface side of the near-field mask to the front surface side due to a pressure difference with a high external pressure. In any case, a pressure difference may be provided so that the pressure on the back surface side is higher than that on the front surface side of the mask.

Thereafter, the foreign matter sandwiched between the pseudo mask 802 and the resist 806 / substrate 805 is detected using the foreign matter detection method of the present invention described above. Light is irradiated from the back side of the pseudo mask 802, and interference fringes due to a gap generated around the foreign substance between the pseudo mask and the resist 806 / substrate 805 are caused to pass through the optical system 807 such as an objective lens from the back side of the pseudo mask 802 through the CCD. It is detected by a light receiving element 808 such as. Thereafter, the location of the resist 806 / substrate 805 to be detected is changed, and foreign matter detection is performed in the same manner as described above, so that the foreign matter attached to the pseudo mask 802 and the foreign matter attached to the resist 806 / substrate 805 are selected. The foreign matter adhering to the resist 806 / substrate 805 is detected.
Here, the detected signal from the light receiving element may be merely viewed on the monitor, but the image processing may be performed through the image processing system 821 to calculate information on the foreign matter, and may be automatically stored and mapped.
As a result of the detection, if foreign matter is adhered on the resist / substrate, the resist / substrate is disposed without being subjected to the exposure processing, or the foreign matter is removed and then the exposure processing is performed.

In parallel with the detection of the foreign matter adhering to the resist / substrate described above, the foreign matter between the exposure mask 801 and the transparent substrate 818 is similarly detected.
A transparent substrate 818 is attached to the stage 817, and the stage 817 is driven in the normal direction of the exposure mask 801 surface, so that the distance between the surface of the exposure mask 801 and the surface of the transparent substrate 818 is 100 nm or less over the front surface. As a method for the close contact, the same method as the close contact method between the pseudo mask 802 and the resist 806 / substrate 805 described above is used.

Thereafter, the foreign matter sandwiched between the exposure mask 801 and the transparent substrate 818 is detected using the foreign matter detection method of the present invention described above. An optical system such as an objective lens is formed from the back side of the transparent substrate 818 by irradiating light from the back side (stage side) of the transparent substrate 818 and causing interference fringes due to a gap between the exposure mask 801 and the transparent substrate 818 with a foreign object as a center. Detection is performed by a light receiving element 811 such as a CCD through 810. Thereafter, the location of the transparent substrate 818 to be detected is changed, and foreign matter detection is performed in the same manner as described above, whereby the foreign matter attached to the exposure mask 801 and the foreign matter attached to the transparent substrate 818 are selected, and the exposure mask 801 is selected. Detect foreign matter adhering to the.
Here, the detected signal from the light receiving element may be simply viewed on the monitor, but the image processing may be performed through the image processing system 822 to calculate information on the foreign matter, and may be automatically stored and mapped.
As a result of detection, if foreign matter is attached to the exposure mask, do not perform exposure processing using the exposure mask, replace it with a new mask, or clean the exposure mask and detect foreign matter again to confirm the removal of foreign matter. Proceed to exposure processing.

As described above, the foreign matter adhering to the object to be processed (resist 806 / substrate 805) and the exposure mask 801 is detected, and no foreign matter is attached to the object to be processed (resist 806 / substrate 805) and the exposure mask 801. It became. Thereafter, the object to be processed (resist 806 / substrate 805) is moved to the exposure processing position 816 by driving the stage 815. At the same time, the pressure adjustment container 804 with the exposure mask 801 is moved to the exposure processing position 816 by an actuator (not shown).
By driving the stage 815, relative alignment of the object to be processed (resist 806 / substrate 805) in the two-dimensional direction in the mask plane with respect to the exposure mask 801 is performed. Next, the stage 815 is driven in the normal direction of the mask surface, and both are brought into close contact so that the distance between the front surface of the exposure mask 801 and the object to be processed (resist 806 / substrate 805) is 100 nm or less over the entire surface. . As the method for the close contact, the same method as the close contact method at the time of detecting the foreign matter described above is used.

  Thereafter, the exposure light 819 emitted from the exposure light source 813 is collimated by the collimator lens 814, then passed through the glass window 820, introduced into the pressure adjustment container 804, and the back surface (in FIG. 8, in FIG. 8). Exposure of the resist 806, which is the object to be processed (resist 806 / substrate 805), in the near field that irradiates from the upper side) and exudes from the minute opening pattern formed in the light shielding film on the mask base material of the exposure mask 801. I do.

Next, peeling of the exposure mask and the object to be processed after the near-field exposure is completed is performed as follows.
Using the pressure adjusting means 812, the pressure in the pressure adjusting container 804 is made smaller than the external atmospheric pressure, and the exposure mask 801 is peeled from the object to be processed.
As described above, in the apparatus configuration for applying pressure at the time of close contact, the front surface of the exposure mask and the resist / substrate are arranged in a decompression container as a construction opposite to that in FIG. When the pressure is applied from the back surface side of the exposure mask to the front surface side due to the pressure difference between and the inside of the container, the pressure inside the container may be set higher than the external pressure at the time of peeling.
In any case, at the time of peeling, a pressure difference may be provided so that the pressure on the back surface side is lower than that on the front surface side of the exposure mask.
By adopting the above-described configuration, the foreign matter existing between the thin film exposure mask and the object to be processed can be detected. As a result, defects such as manufactured wafers and glass substrates were reduced, and the yield could be improved.

It is a figure which shows the structure in Embodiment 1 of this invention, (a) is a figure which shows the structure of the near-field exposure apparatus to which the foreign material detection means of this invention is applied, (b) is irradiated on the light receiving element. The figure which shows the interference fringe by the intensity distribution of light. It is a figure which shows the structure in Embodiment 2 of this invention, (a) is a figure which shows the structure of the near field exposure apparatus to which the foreign material detection means of this invention is applied, (b) is irradiated on the light receiving element. The figure which shows the interference fringe by the intensity distribution of light. The figure explaining the concept by which the exposure using near field light is inhibited by the foreign material in the subject of this invention. The figure which shows the structure of the exposure mask for describing embodiment of this invention. The figure which shows the structure of the exposure mask for demonstrating Embodiment 3 of this invention. The figure explaining the foreign material detection method in the near field exposure of Embodiment 3 of this invention. The figure explaining the foreign material detection method in the near field exposure by another aspect of Embodiment 3 of this invention. The figure explaining the foreign material detection method in the near field exposure of Embodiment 4 of this invention.

Explanation of symbols

101, 201: exposure mask 102 metal light shielding film 103: pressure adjusting container 104: mask base material 105, 205: substrate 106, 206: resist 107, 207: light source 108 for detecting foreign matter 108, 208: half mirror 109, 209: reference surface 110, 210: light receiving element 111: foreign matter 112: beam expander 113: collimator lens 114: collimator lens 115: exposure light source 116: glass window 117: pressure adjusting means 118: stage 211, 212: deflection element 301: photomask 302: foreign matter 303: Object 304: Non-contact area 305: Micro opening 306: Near field light 401: Mask base material 402: Light shielding layer 403: Micro opening 404: Thin film elastic body 405: Support body 501: Pseudo mask 502: Support body 503: Thin film portion 601: Pseudo mask 602: Processed 603: Foreign matter 604: Non-contact area 605: Interference fringe 701: Light shielding layer 702: Mask base material 703: Transparent substrate 704: Foreign substance 705: Exposure mask 706: Non-contact area 707: Interference fringe 801: Exposure mask 802: Pseudo mask 803 804: Pressure adjusting container 805: Substrate 806: Resist 807, 810: Light receiving optical system 808, 811: Light receiving element 809, 812: Pressure adjusting means 813: Exposure light source 814: Collimator lens 815: Stage 816: Exposure processing position 817: Stage 818: Transparent substrate 819: Exposure light 820: Glass window 821, 822: Image processing system

Claims (10)

A foreign matter detection method between substrates for detecting foreign matter existing between these substrates when the elastically deformable first substrate is deformed and brought into close contact with a second substrate that is not elastically deformed.
Adhering the first substrate to the second substrate;
Detecting the deformation of the first substrate caused by foreign matter adhering to these substrates existing between the first substrate and the second substrate;
A method for detecting foreign matter between substrates, comprising: Detecting the deformation of the first substrate,
Irradiating light onto the first substrate and a flat reference surface;
Observing interference fringes caused by reflected light from the first substrate reflected from the first substrate and reflected light from the reference surface reflected from the reference surface;
The method for detecting foreign matter between substrates according to claim 1, wherein:   In the step of irradiating light to the first substrate and the flat reference surface, the light irradiation to the first substrate is light irradiation to irradiate the entire surface of the first substrate, or 3. The method for detecting foreign matter between substrates according to claim 2, wherein the light irradiation is performed to optically scan the entire surface of the first substrate.   The reference surface is the second substrate, and light irradiation to the first substrate and the flat reference surface is irradiation from the first substrate side or the second substrate side. The method for detecting foreign matter between substrates according to claim 2 or 3.   The step of observing the interference fringes includes a step of calculating, from the interference fringes, the position, height, size of the foreign matter, or a region where the first substrate and the second substrate are separated from each other. The foreign matter detection method between substrates of any one of Claims 2-4 characterized by the above-mentioned. In a near-field exposure method in which an exposure mask is deformed and brought into close contact with an object to be processed, and exposure is performed using a near field that oozes out from a minute opening formed in the exposure mask.
A near-field exposure method comprising a step of detecting foreign matter existing between the exposure mask and the object to be processed when the exposure mask is brought into close contact with the object to be processed.   The step of detecting the foreign matter includes a step of removing the foreign matter or exchanging the exposure mask or the object to be processed with a foreign matter not attached based on the detection result of the foreign matter. 6. The near-field exposure method according to 6. A foreign matter detection device between substrates for detecting foreign matter existing between a first substrate that is elastically deformable and a second substrate that is not elastically deformed,
An adhesion means for closely adhering the first substrate and the second substrate;
Shape detecting means for detecting deformation of the first substrate caused by foreign matter attached to these substrates existing between the first substrate and the second substrate;
An apparatus for detecting foreign matter between substrates, comprising: The shape detecting means is
A light irradiation means for irradiating the first substrate and a flat reference surface with light;
A light receiving element that receives light of interference fringes caused by reflected light reflected from the first substrate and reflected light reflected from the reference surface; and
Means for obtaining information of the foreign matter from a signal from the light receiving element;
A processing device for calculating a region where the first substrate and the second substrate are separated from each other;
The apparatus for detecting foreign matter between substrates according to claim 8. In a near-field exposure apparatus that performs exposure using a near-field oozing from a minute opening formed in the exposure mask by deforming the exposure mask and closely contacting the object to be processed,
A near-field exposure apparatus, comprising foreign matter detection means for detecting foreign matter existing between the exposure mask and the object to be processed.

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