JP2009230020A - Defect correction device, defect correction method and method for manufacturing patterned substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defect correction device and method for reliably correcting a defect, and also to provide a method for manufacturing a patterned substrate. <P>SOLUTION: The defect correction device is equipped with: correction optics 20 for irradiating a defective part of a sample with a laser beam through an objective lens 43; and illumination optics 50 for irradiating and illuminating the sample with a laser beam at the same wavelength as the above laser beam through the objective lens 43 to observe the sample 70, wherein the illumination optics 50 has a homogenizing part 65 for homogenizing the spatial distribution of a laser beam. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a defect correction apparatus, a defect correction method, and a pattern substrate, and more particularly to a defect correction apparatus, a defect correction method, and a pattern substrate that correct a defect portion by irradiating a laser beam.

  A laser repair device for correcting a defect of a pattern substrate is disclosed (Patent Document 1). In such a laser repair apparatus, the defect is removed by irradiating the defective portion of the pattern with laser light. As a result, the wiring pattern of the semiconductor device and the light shielding pattern of the photomask can be corrected. Further, a visible light source is provided for positioning a portion to be corrected and for checking a defect correction result. Therefore, the laser repair apparatus is provided with a correction optical system for irradiating the laser beam and an observation optical system for observing the defect portion. By providing an optical system for observation, the corrected portion can be confirmed.

  In order to observe the defective portion irradiated with the laser light, the laser light and the illumination light are incident on substantially the same position. That is, the optical axis of the correcting optical system and the optical axis of the observing optical system are merged on the way. Therefore, a dichroic mirror or a half mirror is provided at a position where the optical axes meet. For example, the illumination light is reflected by the half mirror and the laser light is transmitted through the half mirror, so that the optical axes merge. Accordingly, the objective lens is shared in these optical systems.

  Furthermore, in the defect correction method using laser light, a technique for preventing redeposition of debris generated by laser irradiation is disclosed (Patent Document 2). In the method of Patent Document 2, a resist is formed on a chrome pattern to cover a defective portion. Then, while supplying a gas containing carbon, the resist on the chromium pattern is irradiated with an energy beam. Thereby, the resist of the defective part is removed. Then, the gas supply is stopped and the energy beam is irradiated to the chromium pattern. In the portion where the resist is removed, the black defect of the chromium pattern is removed by etching. An ion beam or a laser beam is used as the energy beam.

JP-A-5-228678 JP 63-47769 A

  Moreover, in patent document 2, the irradiation position of a beam cannot be confirmed. Accordingly, it is impossible to accurately irradiate the defective portion with the energy beam. It is also difficult to confirm whether the defect has been reliably corrected.

  Further, in order to improve the spatial resolution of defect correction by laser light, it is necessary to shorten the wavelength of the laser light. For example, the resolution can be improved by using a KrF laser having an oscillation wavelength of 248 nm. Further, visible light is usually used for observing the defective portion. In the case of defect correction using ultraviolet laser light, the wavelength range differs between observation illumination light and correction laser light. If the wavelength of the laser light and the wavelength range of the illumination light are different, defect correction cannot be reliably performed due to chromatic aberration of the objective lens. That is, the incident position of the laser beam and the incident position of the illumination light are shifted on the sample. Therefore, there is a problem that it is difficult to reliably correct the defect.

  An object of the present invention is to provide a defect correcting apparatus, a defect correcting method, and a pattern substrate manufacturing method capable of reliably correcting a defect.

A defect correction apparatus according to a first aspect of the present invention is a defect correction apparatus that corrects a defect in a pattern provided on a sample, and irradiates a defective portion of the sample with a laser beam through an objective lens. A correction optical system and an illumination optical system for irradiating the sample with illumination light having the same wavelength as the laser beam through the objective lens in order to observe the sample. Thereby, since the optical axes of the illumination optical system and the correction optical system coincide with each other, the defect can be reliably corrected.
A defect correction apparatus according to a second aspect of the present invention is the defect correction apparatus described above, wherein the illumination optical system includes a uniformizing unit that equalizes the intensity distribution of the illumination light. is there. Thereby, since the optical axes of the illumination optical system and the correction optical system coincide with each other, the defect can be reliably corrected. Thereby, since it can illuminate with the illumination light made uniform and weakened, it can prevent that a sample is processed during observation.

  A defect correction device according to a third aspect of the present invention is the above-described defect correction device, wherein the illumination optical system causes the laser beam used for defect correction to enter the homogenization unit, and the homogenization unit The sample is irradiated with light emitted from as illumination light. Thereby, since illumination and defect correction can be performed with one laser light source, the apparatus configuration can be simplified.

  A defect correction apparatus according to a fourth aspect of the present invention is the above-described defect correction apparatus, wherein the uniformizing unit includes a two-dimensional diffraction grating on which illumination light is incident and a plurality of diffractions from the two-dimensional diffraction grating. A light guide member through which light is incident and propagates inside while repeating the total reflection, and a changing means for changing an incident position of the diffracted light from the two-dimensional diffraction grating on the incident end face of the light guide member; It is what has. Thereby, since speckle noise is reduced, a defective part can be observed easily.

A defect correction apparatus according to a fifth aspect of the present invention is the defect correction apparatus described above, wherein an emission end face of the light guide member is disposed at a position conjugate with the sample. Thereby, since uniform surface illumination can be performed, a defective part can be observed easily.
A defect correction apparatus according to a sixth aspect of the present invention is the defect correction apparatus described above, wherein the objective lens is a catadioptric objective lens. Thereby, an objective lens having a long working distance can be used. Furthermore, a pellicle for protecting the objective lens can be used in combination.

  A defect correction apparatus according to a seventh aspect of the present invention is the above-described defect correction apparatus, wherein a protective film is provided so as to cover a pattern provided on the sample, and the protective film in the defective portion is removed. Further, the pattern is etched through the protective film from which the defective portion has been removed by irradiating the laser beam. Thereby, it can prevent that the etched part adheres on a sample. In addition, etching around the defective portion can be prevented. Therefore, it is possible to surely correct the defect.

  A defect correction apparatus according to an eighth aspect of the present invention is the above-described defect correction apparatus, further comprising a jet part for jetting an etching gas around the defect part, and the periphery of the defect part becomes an etching gas atmosphere. In this state, the pattern is photoexcited and etched by irradiating the laser beam. Thereby, since defects can be corrected by continuous irradiation with laser light, productivity can be improved.

A defect correction method according to a ninth aspect of the present invention is a defect correction method for correcting a defect of a pattern provided on a sample using a laser beam, and the laser beam is used for observing the sample. Illuminating the sample by causing the illumination light to be incident on the sample via the objective lens of the illumination optical system; and And detecting the reflected light reflected by the objective lens through the objective lens and irradiating the sample with the laser light through the objective lens. Thereby, since the optical axes of the illumination optical system and the correction optical system coincide with each other, the defect can be reliably corrected.
A defect correction method according to a tenth aspect of the present invention is the above-described defect correction method, further comprising a step of homogenizing a spatial distribution of the illumination light in the middle of the illumination optical system. The illumination light is incident on the sample through the objective lens of the illumination optical system to illuminate the sample. Thereby, since it can illuminate with the illumination light made uniform and weakened, it can prevent that a sample is processed during observation.

  A defect correction method according to an eleventh aspect of the present invention is the defect correction method described above, wherein the illumination of the sample and the defect correction are performed by laser light from the same laser light source. Is. Thereby, since illumination and defect correction can be performed with one laser light source, the apparatus configuration can be simplified.

  A defect correcting method according to a twelfth aspect of the present invention is the above-described defect correcting method, wherein in the step of uniformizing the spatial distribution of the illumination light, the illumination light is incident on a two-dimensional diffraction grating, and the two A plurality of diffracted lights from the three-dimensional diffraction grating are made incident on the light guide member, the light propagated while repeating the total reflected light inside the light guide member is emitted from the light guide member, and at the incident end face of the light guide member, The incident position of the diffracted light from the two-dimensional diffraction grating is changed. Thereby, since speckle noise is reduced, a defective part can be observed easily.

  A defect correcting method according to a thirteenth aspect of the present invention is the above-described defect correcting method, wherein the exit end face of the light guide member is arranged at a position conjugate with the sample. Thereby, since uniform surface illumination can be performed, a defective part can be observed easily.

  A defect correcting method according to a fourteenth aspect of the present invention is the above-described defect correcting method, wherein a protective film covering a pattern provided on the sample is formed, and the protective film in the defective portion is removed. The sample is irradiated with the laser beam, and the pattern is etched using the protective film from which the defective portion has been removed as a mask. Thereby, it can prevent that the etched part adheres on a sample. In addition, etching around the defective portion can be prevented. Therefore, it is possible to surely correct the defect.

  A defect correcting method according to a fifteenth aspect of the present invention is the above-described defect correcting method, wherein an etching gas is jetted around the defective portion, and the laser is irradiated in an etching gas atmosphere around the defective portion. The pattern is photoexcited and etched by irradiating light. Thereby, since defects can be corrected by continuous irradiation with laser light, productivity can be improved.

  A defect correction method according to a sixteenth aspect of the present invention is the defect correction method described above, wherein the sample is irradiated with laser light to correct a defect in a pattern provided on the sample. Irradiating a protective film provided on the pattern with a laser beam to remove the protective film at a defective portion; and supplying the etching gas to the sample from which the protective film has been removed; Irradiating the sample with laser light in the etching gas atmosphere, and photoexciting the pattern of the portion from which the protective film has been removed. Thereby, since a defect can be corrected in a simple process, productivity can be improved.

  A defect correction method according to a seventeenth aspect of the present invention is the above-described defect correction method, comprising: irradiation with a laser beam for removing the protective film; and irradiation with a laser beam for etching the pattern. It is done continuously. Thereby, productivity can be improved.

  According to an eighteenth aspect of the present invention, there is provided a method for manufacturing a patterned substrate, comprising: forming a pattern on a sample; detecting a defect in the pattern on the sample; and correcting the defect by the defect correcting method described above. Thereby, productivity can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the defect correction apparatus which can correct a defect reliably, the defect correction method, and the manufacturing method of a pattern board | substrate can be provided.

Embodiments of the present invention will be described below with reference to the drawings. The following description shows preferred embodiments of the present invention, and the scope of the present invention is not limited to the following embodiments. In the following description, the same reference numerals indicate substantially the same contents.
The defect correction apparatus according to the present embodiment is a defect correction apparatus that corrects a defect of a pattern provided on a sample. The defect correction apparatus includes a correction optical system that irradiates a defective portion of a sample with a laser beam through an objective lens, and illumination light having the same wavelength as that of the laser beam through the objective lens so as to observe the sample. And an illumination optical system for irradiation. Furthermore, the illumination optical system may include a uniformizing unit that uniformizes the intensity distribution of the illumination light.

Embodiment 1 FIG.
A defect correction apparatus according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration of a defect correction apparatus according to the present embodiment. The defect correction apparatus according to the present embodiment irradiates the sample 70 with laser light in order to correct the defect. Accordingly, a correction optical system 20 for guiding the laser beam from the laser light source 11 to the sample 70 is provided. Further, the sample 70 is illuminated by illumination light from the lamp light source 81. That is, the lamp light source 81 is an illumination light source. An illumination optical system 50 for guiding the illumination light to the sample is provided. In order to confirm whether or not the defect is surely corrected, the defective portion of the sample 70 is confirmed. Accordingly, an illumination optical system 50 for guiding the lamp illumination light from the lamp light source 81 to the sample 70 is provided. The illumination optical system 50 performs epi-illumination on the sample 70. Further, the sample 70 is illuminated with illumination light having the same wavelength as the laser wavelength by the interference filter 82 arranged at the subsequent stage of the lamp light source 81.

A frame-like pellicle frame 77 is attached to the objective lens. The pellicle frame 77 is provided with a transparent pellicle 78. Thereby, the tip of the objective lens 43 is sealed with the pellicle frame 77 and the pellicle 78, and debris and the like generated during processing can be prevented from adhering to the lens surface.
Here, description will be made assuming that the sample 70 is a photomask used in the manufacturing process of the semiconductor device. Therefore, a light shielding pattern is formed on the photomask. Furthermore, the sample 70 may be provided with a pellicle for preventing adhesion of foreign substances or the like. The pellicle is attached to the sample 70 via a pellicle frame. A frame-shaped pellicle frame is attached to the pattern surface of the sample 70. The pellicle frame is formed so as to surround a region where the pattern of the sample 70 is formed. A transparent pellicle is provided on the surface of the pellicle frame opposite to the sample 70. Thereby, the pattern of the sample 70 is surrounded by the pellicle and the pellicle frame. Therefore, the space on the pattern of the sample 70 is sealed by the pellicle and the pellicle frame, and foreign matter or the like can be prevented from adhering to the pattern surface.

  In the present embodiment, laser light for defect correction is irradiated through the pellicle 78. Further, illumination light for observation is irradiated through the pellicle 78.

  In the present embodiment, the illumination optical system 50 and the correction optical system 20 share the objective lens 43. That is, the same objective lens 43 irradiates the sample with correction laser light and illumination light. Furthermore, since they have the same wavelength, there is no large chromatic aberration. Thereby, the incident position of the illumination light and the laser beam for correction can be matched. Therefore, the defect can be corrected accurately. Moreover, since the illumination light for observation is not condensed on the sample 70 but is widely illuminated, it is possible to prevent the sample 70 from being processed during observation.

  First, the correction optical system 20 will be described. A laser beam for defect correction is emitted from the laser light source 11. Ultraviolet light is emitted from the laser light source 11. The laser light source 11 is, for example, a KrF excimer laser, and emits laser light having a wavelength of 248 nm. Alternatively, a Q-switched Nd: YAG laser can be used as the laser light source 11. In this case, it is preferable to use a fourth harmonic having a wavelength of 266 nm. Laser light from the laser light source 11 enters the lens 12. The laser light refracted by the lens 12 enters the slit 24. Here, the lens 12 condenses the laser light on the slit 24. Accordingly, the slit 24 is disposed at the focal position of the lens 12.

  The slit 24 has an opening for allowing the laser beam to pass therethrough. Of course, it is also possible to shape the beam by making the opening of the slit 24 variable. That is, the opening width and the opening shape of the slit 24 may be changed in accordance with the region for correcting the defect. An image of the slit 24 is projected on the sample 70. Therefore, the slit 24 is disposed at a position conjugate with the sample 70. Thereby, a laser beam can be irradiated to a desired area.

  The laser beam that has passed through the slit 24 enters the mirror 31. The mirror 31 is detachably provided in the optical path of the laser beam. In other words, the mirror 31 is provided with a drive mechanism 31 a for driving the mirror 31. When the drive mechanism 31a is driven, the mirror 31 moves in the direction of the arrow. For example, the mirror 31 is inserted into the optical path when the defect is corrected, and the mirror 31 is removed from the optical path when observing. Thus, by driving the mirror 31, the defect correction mode and the observation mode are switched. That is, when shifting from the defect correction mode to the observation mode, the mirror 31 is removed from the optical path. On the contrary, when shifting from the observation mode to the defect correction mode, the mirror 31 is inserted into the optical path.

  The laser beam reflected by the mirror 31 is reflected in the direction of the sample 70. Therefore, the laser beam reflected by the mirror 31 enters the lens 32. Then, the laser light refracted by the lens 32 enters a PBS (polarization beam splitter) 41. The PBS 41 reflects or transmits light according to the polarization state. For example, the P-polarized component passes through the PBS 41, and the S-polarized component is reflected by the PBS 41. As a result, the P-polarized component of the laser light passes through the PBS 41. The laser beam that has passed through the PBS 41 is linearly polarized.

  The laser beam that has passed through the PBS 41 is incident on the λ / 4 plate 42. The λ / 4 plate 42 shifts the phase between the ordinary light component and the extraordinary light component by 90 °. Therefore, the light that has passed through the λ / 4 plate 42 is circularly polarized. The laser light that has passed through the λ / 4 plate 42 enters the objective lens 43. The objective lens 43 condenses the laser light on the sample 70. Laser light from the objective lens 43 enters the sample 70 via the pellicle 78. On the sample 70, the spot diameter of the laser light is, for example, about 0.3 μm. An image of the slit 24 is formed on the sample 70. Thereby, a laser beam can be irradiated to a desired area. The sample 70 is placed on the movable stage 76. The movable stage 76 is, for example, an XY stage, and can move the position of the sample 70 with respect to the optical axis.

  Further, a catadioptric objective lens is used as the objective lens 43. That is, a lens and a reflecting mirror are provided in the lens barrel of the objective lens 43. The catadioptric objective lens 43 has a large NA (numerical aperture) and a long working distance. Thereby, the distance from the pattern surface of the sample 70 to the objective lens 43 can be separated. Therefore, debris at the time of defect correction can be prevented from adhering to the objective lens 43. Furthermore, even when the objective lens 43 with a pellicle is used or when the mask with the pellicle 78 is used as the sample 70, the pellicle and the objective lens 43 or the sample 70 do not interfere with each other because the working distance is long. Thus, when the objective lens 43 with a pellicle is used or when the mask with a pellicle is used as the sample 70, the catadioptric objective lens 43 is preferable. Further, by performing observation and correction with the pellicle 78 attached, it is possible to prevent debris generated at the time of defect correction from adhering to the objective lens 43. That is, debris generated by laser irradiation can be prevented from adhering to the objective lens 43. Further, with a catadioptric objective lens, chromatic aberration correction (achromaticity) is easy. Thereby, the lamp light source 11 with a wide half value width can be used.

  Next, the illumination optical system 50 will be described. Here, a part of the illumination optical system 50 has the same optical axis as that of the correction optical system 20. Thereby, since the objective lens 43 can be shared, the apparatus configuration can be simplified. The illumination light is irradiated as illumination light by passing through the illumination optical system 50. Further, a part of the illumination optical system 50 is common to a part of the correction optical system 20.

  The lamp light source 81 is, for example, a mercury xenon lamp. The lamp illumination light emitted from the lamp light source 81 has a spectrum including the laser wavelength. That is, broad continuous spectrum illumination light including the laser wavelength of 248 nm is emitted from the lamp light source 81. Of course, a light source other than the mercury xenon lamp may be used as the light source for illumination.

  The illumination light emitted from the lamp light source 81 enters the light guide member 56 through the lens 53, the interference filter 82, and the lens 55. Here, the interference filter 82 is a band-pass filter, for example, and transmits only a necessary wavelength. Here, the interference filter 82 transmits light having the same wavelength 248 nm as the laser wavelength. Therefore, the center wavelength of the light transmitted through the interference filter 82 is 248 nm, and light whose wavelength is shifted from 248 nm is shielded.

  The illumination light is refracted by the lens 55 and condensed on the end face (incident end face) of the light guide member 56. The light guide member 56 is a transparent member such as a square rod or an optical fiber. The illumination light propagates by repeating total reflection inside the light guide member 56. Then, the light is emitted from the end face (outgoing end face) of the light guide member 56. Therefore, the spatial intensity distribution of light is uniform on the exit end face of the light guide member 56. Therefore, the light guide member 56 is a uniformizing unit that uniformizes the spatial distribution of illumination light. That is, the spatial distribution of the light intensity at the exit end face of the light guide member 56 is uniform.

  The illumination light from the light guide member 56 enters the mirror 60 through the lens 57, the diaphragm 58, and the lens 59. The mirror 60 reflects the illumination light in the direction of the PBS 41. The illumination light reflected by the mirror 60 enters the PBS 41 via the diaphragm 61 and the lens 62. As described above, the PBS 41 transmits or reflects light according to the polarization state. Accordingly, the S-polarized component of the illumination light incident on the PBS 41 from the lens 62 is reflected in the direction of the sample 70.

  The illumination light reflected by the PBS 41 becomes circularly polarized light by the λ / 4 plate 42 and enters the objective lens 43. The objective lens 43 collects the illumination light on the sample 70. Illumination light from the objective lens 43 enters the sample 70 via the pellicle 78. Here, the sample 70 and the emission end face of the light guide member 56 are arranged at conjugate positions. Thereby, it can illuminate with illumination light with a uniform spatial distribution. In the illumination optical system 50, the illumination light uses only a part of the pupil. Therefore, the spot diameter of the illumination light incident on the objective lens 43 is smaller than the spot diameter of the correction laser light.

  Next, the observation optical system will be described. The optical system for observation has the same optical axis as a part of the illumination optical system 50. That is, the reflected light reflected by the sample 70 propagates along the optical axis common to the illumination light. The reflected light reflected by the sample 70 enters the objective lens 43 through the pellicle 78. The reflected light refracted by the objective lens 43 passes through the λ / 4 plate 42 and enters the PBS 41. Here, the λ / 4 plate 42 converts the reflected light, which has been circularly polarized, into P-polarized light. The forward path from the PBS 41 to the objective lens 43 and the return path from the objective lens 43 to the PBS 41 pass through the λ / 4 plate 42 once. That is, the light passes through the λ / 4 plate 42 twice while reciprocating between the PBS 41 and the sample 70. For this reason, a phase difference of 180 ° occurs between the ordinary light component and the extraordinary light component. As a result, the light that was S-polarized when reflected by the PBS 41 becomes P-polarized and enters the PBS 41. By doing in this way, light can be efficiently guided to the camera 63. The optical axis of illumination light and reflected light is branched by the PBS 41.

  The reflected light that has passed through the PBS 41 enters the camera 63 through the lens 32. During observation, the mirror 31 is removed from the optical path by the drive mechanism 31a. The lens 32 condenses the reflected light on the light receiving surface of the camera 63. Thereby, an image of the sample 70 is formed on the camera 63. Therefore, the sample 70 can be observed. Based on the image of the sample 70 captured by the camera 63, the defective portion of the sample 70 is observed. Thereby, it is possible to reliably irradiate the defect of the sample 70 with the laser beam. In addition, the finish of the correction can be confirmed.

  As described above, the optical axis of the correction optical system 20 is merged with the optical axis of the illumination optical system 50 by the PBS 41. Then, the illumination light for observation and the correction laser light propagate along a common optical axis. An objective lens 43 is disposed on the common optical axis. That is, the optical paths from the PBS 41 to the sample 70 are the same. Furthermore, since correction and observation are performed with light of the same wavelength, the deviation due to chromatic aberration of the objective lens 43 is eliminated. That is, the incident position of the correction laser light and the incident position of the illumination light in the sample 70 coincide with each other. Thereby, the shift | offset | difference of the irradiation position of the light by the chromatic aberration of the objective lens 43 can be suppressed. Therefore, it is possible to surely correct the defect.

  Furthermore, the spatial distribution of the illumination light is made uniform by the light guide member 56. That is, surface illumination with a uniform spatial distribution of light incident on the sample 70 is performed. For this reason, even when the illumination light having the same wavelength as the laser beam for correction is used, it is possible to prevent the sample 70 from being processed by the illumination light during observation. That is, since surface illumination is performed, the power density of the illumination light is lower than that of the correction laser light. The resist is not processed even when illumination light with low power density is irradiated. Therefore, the defect can be corrected with high accuracy.

  Note that when the lamp light source 81 is used as in the present embodiment, the light guide member 56 need not be used. That is, the light guide member 56 may be removed from the illumination optical system 50.

Embodiment 2. FIG.
The defect correction apparatus according to this embodiment will be described with reference to FIG. FIG. 2 is a diagram showing a configuration of the defect correction apparatus according to the present embodiment. The defect correction apparatus according to the present embodiment irradiates the sample 70 with laser light in order to correct the defect. Accordingly, a correction optical system 20 for guiding the laser beam from the laser light source 11 to the sample 70 is provided. Further, the sample 70 is illuminated by the laser light from the same laser light source 11. That is, the laser light source 11 becomes an illumination light source. An illumination optical system 50 for guiding the illumination light to the sample is provided. In order to confirm whether or not the defect is surely corrected, the defective portion of the sample 70 is confirmed. Accordingly, an illumination optical system 50 for guiding the laser light from the laser light source 11 to the sample 70 is provided. The illumination optical system 50 performs epi-illumination on the sample 70.

In the present embodiment, the illumination optical system 50 and the correction optical system 20 share the objective lens 43. That is, the correction laser beam and the illumination beam are collected on the sample by the same objective lens 43. Furthermore, since they have the same wavelength, there is no large chromatic aberration. Thereby, the incident position of the illumination light and the laser beam for correction can be matched. Therefore, the defect can be corrected accurately. Moreover, since the illumination light for observation is not condensed on the sample 70 but is widely illuminated, it is possible to prevent the sample 70 from being processed during observation.
Note that a pattern substrate such as a photomask or a semiconductor wafer can be used as the sample 70 to be corrected by the defect correction apparatus according to the present embodiment. Of course, as shown in Embodiment Mode 1, a photomask with a pellicle may be used as the sample 70.

  First, the correction optical system 20 will be described. A laser beam for defect correction is emitted from the laser light source 11. Ultraviolet light is emitted from the laser light source 11. The laser light source 11 is, for example, a KrF excimer laser, and emits laser light having a wavelength of 248 nm. Alternatively, a Q-switched Nd: YAG laser can be used as the laser light source 11. In this case, it is preferable to use a fourth harmonic having a wavelength of 266 nm. Laser light from the laser light source 11 enters the lens 12. The laser light refracted by the lens 12 enters the lens 13. The lens 12 and the lens 13 constitute a beam reducer (beam contractor). Thereby, the spot diameter of the laser beam is reduced to an appropriate size. Further, the laser light is collimated by the lens 12 and the lens 13 to become a parallel light beam. The laser light from the lens 13 is reflected by the mirror 14 in the direction of the mirror 15.

  The mirror 15 is detachably provided in the optical path of the laser beam. That is, the mirror 15 is provided with a drive mechanism 15 a for driving the mirror 15. When the drive mechanism 15a is driven, the mirror 15 moves in the direction of the arrow. For example, when correcting the defect, the mirror 15 is inserted into the optical path, and when observing, the mirror 15 is removed from the optical path. Thus, by driving the mirror 15, the defect correction mode and the observation mode are switched.

  The laser beam reflected by the mirror 15 passes through the diaphragm 21 and enters the lens 22. The laser light from the lens 22 is reflected by the mirror 23 and enters the slit 24. Here, the lens 22 condenses the laser light on the slit 24. Accordingly, the slit 24 is disposed at the focal position of the lens 22.

  The slit 24 has an opening for allowing the laser beam to pass therethrough. Of course, it is also possible to shape the beam by making the opening of the slit 24 variable. That is, the opening width and the opening shape of the slit 24 may be changed in accordance with the region for correcting the defect. An image of the slit 24 is projected on the sample 70. Therefore, the slit 24 is disposed at a position conjugate with the sample 70. Thereby, a laser beam can be irradiated to a desired area.

  The laser beam that has passed through the slit 24 enters the mirror 31. The mirror 31 is detachably provided in the optical path of the laser beam. In other words, the mirror 31 is provided with a drive mechanism 31 a for driving the mirror 31. When the drive mechanism 31a is driven, the mirror 31 moves in the direction of the arrow. For example, the mirror 31 is inserted into the optical path when the defect is corrected, and the mirror 31 is removed from the optical path when observing. Thus, by driving the mirror 31, the defect correction mode and the observation mode are switched. That is, when shifting from the defect correction mode to the observation mode, the mirror 15 and the mirror 31 are removed from the optical path. On the other hand, when shifting from the observation mode to the defect correction mode, the mirror 15 and the mirror 31 are inserted into the optical path.

  The laser beam reflected by the mirror 31 is reflected in the direction of the sample 70. Therefore, the laser beam reflected by the mirror 31 enters the lens 32. Then, the laser light refracted by the lens 32 enters a PBS (polarization beam splitter) 41. The PBS 41 reflects or transmits light according to the polarization state. For example, the P-polarized component passes through the PBS 41, and the S-polarized component is reflected by the PBS 41. As a result, the P-polarized component of the laser light passes through the PBS 41. The laser beam that has passed through the PBS 41 is linearly polarized.

  The laser beam that has passed through the PBS 41 is incident on the λ / 4 plate 42. The λ / 4 plate 42 shifts the phase between the ordinary light component and the extraordinary light component by 90 °. Therefore, the light that has passed through the λ / 4 plate 42 is circularly polarized. The laser light that has passed through the λ / 4 plate 42 enters the objective lens 43. The objective lens 43 condenses the laser light on the sample 70. On the sample 70, the spot diameter of the laser light is, for example, about 0.3 μm. An image of the slit 24 is formed on the sample 70. Thereby, a laser beam can be irradiated to a desired area. The sample 70 is placed on the movable stage 76. The movable stage 76 is, for example, an XY stage, and can move the position of the sample 70 with respect to the optical axis.

  Further, in the present embodiment, the ejection portion 25 is provided in the vicinity of the objective lens 43. The ejection part 25 has, for example, a nozzle that ejects gas. The ejection unit 25 supplies an etching gas to the space between the objective lens 43 and the sample 70. As a result, the periphery of the defect portion irradiated with the laser light becomes an etching gas atmosphere. Accordingly, the laser light exits the objective lens 43 and then enters the sample 70 through the etching gas atmosphere. The defect correction process will be described later.

  Next, the illumination optical system 50 will be described. Here, the illumination optical system 50 uses the laser light source 11 common to the correction optical system 20. Thereby, since illumination and defect correction can be performed with one laser light source 11, the apparatus configuration can be simplified. The laser light is irradiated as illumination light by passing through the illumination optical system 50. Further, a part of the illumination optical system 50 is common to a part of the correction optical system 20.

  Laser light from the laser light source 11 enters the mirror 14 via the lens 12 and the lens 13. The mirror 14 reflects the laser light in the direction of the galvanometer mirror 51. At the time of observation, as described above, the mirror 15 is removed from the optical path. Accordingly, the laser light is incident on the galvanometer mirror 51 without being reflected by the mirror 15. A drive mechanism 51 a is connected to the galvanometer mirror 51. The drive mechanism 51 a changes the angle of the reflection surface of the galvanometer mirror 51. Thereby, the laser beam is scanned.

  The galvanometer mirror 51 is, for example, PBS, and reflects light according to the polarization state. The galvanometer mirror 51, which is a PBS, reflects the S-polarized component. The laser beam reflected by the galvanometer mirror 51 enters the two-dimensional diffraction grating 52. As described above, the incident position of the laser beam on the two-dimensional diffraction grating 52 is changed by the galvanometer mirror 51. A predetermined diffraction grating pattern is formed on the two-dimensional diffraction grating 52. The two-dimensional diffraction grating is a transmission type diffraction grating. Therefore, when the laser light is incident on the two-dimensional diffraction grating 52, the diffracted light is emitted from the surface opposite to the incident surface. The diffracted light is emitted with a certain spread. The two-dimensional diffraction grating 52 generates a plurality of diffracted lights from one laser beam to form a two-dimensional multi-spot. That is, the laser light is converted into a plurality of multi-beams by the two-dimensional diffraction grating 52. Then, the multi-beams arranged in a circle are emitted from the two-dimensional diffraction grating 52. For example, a maximum of about 100 multi-beams are arranged in the diameter direction. The two-dimensional diffraction grating 52 is designed to have a diffraction angle that is the same as or slightly larger than the required NA. Each light beam may partially overlap with another adjacent light beam. The multi-beam pattern incident on the two-dimensional diffraction grating 52 is not limited to a circular shape.

  The multi-beam emitted from the two-dimensional diffraction grating 52 enters the light guide member 56 through the lens 53, the stop 54, and the lens 55. The diaphragm 54 is disposed at the position of the pupil of the objective lens 43. The lens 53 and the lens 55 collect a multi-beam having a predetermined divergence angle on the end face (incident end face) of the light guide member 56. The multi-beam propagates by repeating total reflection inside the light guide member 56. Then, the light is emitted from the end face (outgoing end face) of the light guide member 56. Here, the light guide member 56, the two-dimensional diffraction grating 52, the galvanometer mirror 51, and the drive mechanism 51a constitute a uniformizing unit 65 that uniformizes the intensity distribution of the laser light. Therefore, the spatial intensity distribution of light is uniform on the exit end face of the light guide member 56. That is, the spatial distribution of the light intensity at the exit end face of the light guide member 56 is uniform. The uniformizing unit 65 will be described later.

The illumination light from the light guide member 56 enters the mirror 60 through the lens 57, the diaphragm 58, and the lens 59. The mirror 60 reflects the illumination light in the direction of the PBS 41. The illumination light reflected by the mirror 60 enters the PBS 41 via the diaphragm 61 and the lens 62.
As described above, the PBS 41 transmits or reflects light according to the polarization state. Accordingly, the S-polarized component of the illumination light incident on the PBS 41 from the lens 62 is reflected in the direction of the sample 70.

  The illumination light reflected by the PBS 41 becomes circularly polarized light by the λ / 4 plate 42 and enters the objective lens 43. The objective lens 43 collects the illumination light on the sample 70. Here, the sample 70 and the emission end face of the light guide member 56 are arranged at conjugate positions. Thereby, it can illuminate with illumination light with a uniform spatial distribution. In the illumination optical system 50, the illumination light uses only a part of the pupil. Therefore, the spot diameter of the illumination light incident on the objective lens 43 is smaller than the spot diameter of the correction laser light.

  Further, a catadioptric objective lens may be used as the objective lens 43. In the catadioptric objective lens 43, a lens and a reflecting mirror are provided in the lens barrel. The catadioptric objective lens 43 has a large NA (numerical aperture) and a long working distance. Thereby, the distance from the pattern surface of the sample 70 to the objective lens 43 can be separated. Therefore, debris at the time of defect correction can be prevented from adhering to the objective lens 43. When the objective lens 43 with pellicle is used or when the mask with pellicle is used as the sample 70, a catadioptric objective lens is suitable.

  Next, the observation optical system will be described. The optical system for observation has the same optical axis as a part of the illumination optical system 50. That is, the reflected light reflected by the sample 70 propagates along the optical axis common to the illumination light. The reflected light is refracted by the objective lens 43 and enters the λ / 4 plate 42. The reflected light passes through the λ / 4 plate 42 and enters the PBS 41. Here, the λ / 4 plate 42 converts the reflected light, which has been circularly polarized, into P-polarized light. The forward path from the PBS 41 to the objective lens 43 and the return path from the objective lens 43 to the PBS 41 pass through the λ / 4 plate 42 once. That is, the light passes through the λ / 4 plate 42 twice while reciprocating between the PBS 41 and the sample 70. For this reason, a phase difference of 180 ° occurs between the ordinary light component and the extraordinary light component. As a result, the light that was S-polarized when reflected by the PBS 41 becomes P-polarized and enters the PBS 41. By doing in this way, light can be efficiently guided to the camera 63. The optical axis of illumination light and reflected light is branched by the PBS 41.

  The reflected light that has passed through the PBS 41 enters the camera 63 through the lens 32. During observation, the mirror 31 is removed from the optical path by the drive mechanism 31a. The lens 32 condenses the reflected light on the light receiving surface of the camera 63. Thereby, an image of the sample 70 is formed on the camera 63. Therefore, the sample 70 can be observed. Based on the image of the sample 70 captured by the camera 63, the defective portion of the sample 70 is observed. Thereby, it is possible to reliably irradiate the defect of the sample 70 with the laser beam. In addition, the finish of the correction can be confirmed.

  As described above, the optical axis of the correction optical system 20 is merged with the optical axis of the illumination optical system 50 by the PBS 41. Then, the illumination light for observation and the correction laser light propagate along a common optical axis. An objective lens 43 is disposed on the common optical axis. That is, the optical paths from the PBS 41 to the sample 70 are the same. Furthermore, since correction and observation are performed with the light from the same laser light source 11, there is no shift due to chromatic aberration of the objective lens 43. That is, the incident position of the correction laser light and the incident position of the illumination light in the sample 70 coincide with each other. Thereby, the shift | offset | difference of the irradiation position of the laser beam by the chromatic aberration of the objective lens 43 can be suppressed. Therefore, it is possible to surely correct the defect.

  Further, the illumination optical system 50 is provided with a uniformizing unit 65. A method for making the intensity distribution of the laser light uniform by the uniformizing unit 65 will be described. FIG. 3 is a perspective view showing a configuration of the light guide member 56 used in the first and second embodiments. The light guide member 56 has a rectangular rod shape. That is, the light guide member 56 is a quadrangular columnar member, and the light propagation direction is the longitudinal direction. The specific size of the light guide member 56 is about 1 mm × 1 mm × 50 mm. The light guide member 56 is made of, for example, a transparent material having a high refractive index. In addition, the material of the light guide member 56 should just be a thing with a refractive index higher than the periphery (for example, air). The light incident on the light guide member 56 propagates through the inside thereof. That is, the incident light is totally reflected on the side surface of the light guide member 56 and propagates. By this total reflection, the light intensity distribution of the incident diffracted light is made uniform.

  For example, the light guide member 56 is formed of quartz, fluoride, resin, or the like. The light guide member 56 has a rectangular cross-sectional shape. Therefore, even when light having a non-uniform light intensity distribution is incident on the light guide member 56, the light having a uniform light intensity distribution can be emitted from the emission end face of the light guide member 56. Moreover, when the light guide member 56 forms fluoride, far ultraviolet light having a wavelength of 200 nm or less can be propagated. This is because the band gap energy of fluoride is so high that it is not absorbed even in light in this wavelength region.

  In addition, as a specific composition of fluoride, calcium fluoride, magnesium fluoride, barium fluoride, barium fluoride lithium, lithium yttrium fluoride, lithium strontium aluminum fluoride, lithium calcium aluminum fluoride, lithium strontium fluoride Gallium etc. can be used.

  By using such a light guide member 56, light having a spatially uniform distribution is emitted from the emission end face. That is, the light incident from the incident end face propagates while repeating total reflection in the light guide member 56. As a result, the multi-beams at different incident positions are mixed inside the light guide member 56. Furthermore, since the multi-beams have a certain spread, the multi-beams overlap at the exit end face. Then, the distance between the two-dimensional diffraction grating 52 and the light guide member 56 is adjusted so that the light intensity distribution on the exit end face is uniform. Thereby, even if the light intensity distribution is non-uniform at the incident end face, it is made uniform at the outgoing end face. Thus, by making a multi-beam incident on one light guide member 56, a light beam having a uniform spatial light intensity distribution can be extracted. In addition, the light intensity distribution can be made more uniform by increasing the length of the light guide member 56. Furthermore, by using the light propagated through the light guide member 56, the emission angle of the illumination light can be limited. That is, light is not propagated at an angle exceeding the angle of total reflection determined by the refractive index between the light guide member 56 and the surroundings. Therefore, the passage of light inclined by a certain angle or more with respect to the central axis of the light guide member 56 is restricted. Therefore, the angular distribution of illumination light can be limited.

  Furthermore, in the present embodiment, as described above, the galvano mirror 51 is used to scan the laser light minutely. Thereby, the incident position of the laser beam in the two-dimensional diffraction grating 52 changes. Accordingly, the position of the multi-spot diffracted light on the incident end face of the light guide member 56 also changes. That is, the incident position of the light guide member 56 for diffracted light changes according to time. Here, the scanning distance by the galvanometer mirror 51 may be such a distance that one spot of the diffracted light moves to the adjacent spot on the incident end face. Therefore, the scanning cycle can be increased. As described above, by changing the incident position of the diffracted light at a constant period, the incident position of the diffracted light on the incident end face vibrates. That is, in the present embodiment, illumination is performed by light emitted from the light guide member 56 while changing the incident position of the diffracted light from the two-dimensional diffraction grating 52 on the incident end surface of the light guide member 56. Thereby, the exit position of the diffracted light on the exit end face also changes. Therefore, speckle noise can be reduced with a simple configuration.

  For example, when an image sensor such as a CCD camera is used, the scanning cycle of the galvanometer mirror 51 may be set to be longer than the frame cycle of the CCD camera. Therefore, the galvanometer mirror 51 can be 10 Hz or more, for example. Furthermore, it is preferable to scan at a cycle of an integer of the integration time of the CCD camera. As a result, each frame is illuminated with the same light intensity. Uniform illumination is possible by performing illumination using the illumination device according to the present embodiment. Specifically, the exit end face of the light guide member 56 is disposed at a position conjugate with the sample surface. Thereby, uniform surface illumination can be performed. In this way, the exit end face of the light guide member 56 is arranged at a position conjugate with the image plane. The illumination light pattern on the pupil is matched with the far field pattern of the two-dimensional diffraction grating 52. That is, a position conjugate with the pupil is set as the far field of the two-dimensional diffraction grating 52.

  Further, in the present embodiment, the two-dimensional diffraction grating 52 and the light guide member 56 may be integrally formed. That is, the two-dimensional diffraction grating 52 is formed on the incident end face of the light guide member 56. Thereby, the number of parts can be reduced. For example, the two-dimensional diffraction grating 52 and the light guide member 56 can be integrally formed by injection molding. In this case, the two-dimensional diffraction grating 52 and the light guide member 56 are formed of plastic having an appropriate refractive index. Thereby, component cost can be reduced. Furthermore, since all of the multi-beams emitted from the two-dimensional diffraction grating 52 can be made incident on the light guide member 56, light loss can be reduced.

  As described above, the illumination light for observing the sample 70 passes through the uniformizing unit 65. The uniformizing unit 65 makes the light intensity distribution in the horizontal direction uniform. For example, when the intensity distribution of the laser light is a Gaussian distribution, the light intensity on the optical axis becomes weak. That is, the light intensity at the center of the spot is weakened and the light intensity at the periphery thereof is increased. The exit end face of the light guide member 56 is disposed at a position conjugate with the surface of the sample 70. Thereby, uniform surface illumination can be performed. Further, the position of the laser beam incident on the two-dimensional diffraction grating 52 is minutely changed. For this reason, speckle noise can be suppressed even when highly coherent laser light is used. Thereby, a defective part can be observed easily.

  The light guide member 56 is not limited to a square rod. For example, an optical fiber or a bundle fiber can be used. Further, a beam homogenizer having a fly array lens or the like can be used. As described above, the spatial distribution of the illumination light can be made uniform using these so that it can be easily observed.

  Thus, the incident position of the diffracted light on the incident end face of the light guide member 56 is changed. Then, the exit position of the diffracted light on the exit end face also changes. Therefore, speckle noise can be reduced with a simple configuration. Thereby, a defective part can be observed easily.

  Note that the configuration for changing the incident position of the diffracted light on the incident end face is not limited to the galvanometer mirror 51. For example, a transparent plate or the like is inserted between the two-dimensional diffraction grating 52 and the light guide member 56. Then, a drive mechanism is provided on the transparent plate to slightly change the angle of the transparent plate with respect to the optical axis. Thereby, the refraction angle of a multi-beam changes according to time. Even with such a method, the incident position of the diffracted light on the incident end face of the light guide member 56 can be changed.

  In addition, a diffusion plate may be provided between the two-dimensional diffraction grating 52 and the light guide member 56. Then, a drive mechanism is provided on the diffusion plate to rotate the diffusion plate. Thereby, the incident position of the diffracted light on the incident end face of the light guide member 56 can be changed.

  Alternatively, a driving mechanism may be provided in the two-dimensional diffraction grating 52 and the two-dimensional diffraction grating 52 may be rotated. Thereby, the incident position of the diffracted light on the incident end face of the light guide member 56 can be changed.

When a reflection type is used as the two-dimensional diffraction grating 52, the angle of the two-dimensional diffraction grating 52 may be changed. For example, similarly to the galvanometer mirror 51, a drive mechanism for driving the two-dimensional diffraction grating 52 is provided. Then, the angle of the two-dimensional diffraction grating 52 is changed according to time. Thereby, the incident angle of the laser beam with respect to the reflection type two-dimensional diffraction grating 52 changes according to time.
Therefore, the incident position of the diffracted light on the incident end face of the light guide member 56 can be changed.

  The correction optical system 20 includes a lens 12, a lens 13, a mirror 14, a mirror 15, a diaphragm 21, a lens 22, a mirror 23, a slit 24, a mirror 31, a lens 32, a PBS 41, a λ / 4 plate 42, and an objective lens 43. Is provided. On the other hand, the illumination optical system 50 includes a lens 12, a lens 13, a mirror 14, a galvanometer mirror 51, a two-dimensional diffraction grating 52, a lens 53, a diaphragm 54, a lens 55, a light guide member 56, a lens 57, a diaphragm 58, and a lens. 59, a mirror 60, a diaphragm 61, a lens 62, a PBS 41, a λ / 4 plate 42, and an objective lens 43 are provided. Therefore, some optical systems including the objective lens 43 are common. That is, the illumination light and the laser light propagate along the optical axis of the objective lens 43. A common objective lens is used. For this reason, even when the optical system is switched, the deviation of the light irradiation position on the sample 70 can be reduced. Therefore, it is possible to surely correct the defect.

  Next, a process for correcting defects by irradiating laser light will be described with reference to FIG. FIG. 4 is a process cross-sectional view illustrating the defect correcting method according to the present embodiment.

  Here, the pattern of the metal film 72 of the sample 70 is formed on the substrate 71. For example, the substrate 71 is a semiconductor wafer, and the metal film 72 is wiring for a semiconductor circuit. Then, the pattern of the metal film 72 is a correction target. Here, a defect 74 exists in a part of the metal film 72. The defect 74 is a black defect. Therefore, the metal film 72 is present where the metal film 72 does not exist.

  First, as shown in FIG. 4A, a resist 73 is applied on the metal film 72. Thereby, the pattern of the metal film 72 is covered with the resist 73. Then, as shown in FIG. 4B, the defect 74 is irradiated with laser light. As a result, the resist 73 in the portion of the defect 74 is removed, and the metal film 72 is exposed. That is, an opening of the resist 73 is formed at a location irradiated with laser light. In the opening of the resist 73, the metal film 72 is exposed. Here, pulsed laser light is applied to the resist 73. The resist 73 is removed by laser ablation or the like.

Next, while supplying Cl ₂ as an etching gas (etchant), the defect 74 is irradiated with laser light. Note that the etching gas is not particularly limited, and in addition to Cl ₂ , CCl ₄ , CHCl ₃ , CH ₂ Cl, BCl _3, or the like can be used. Of course, you may use the mixed gas which mixed these. Further, a gas other than the above may be used as the etching gas, and it is appropriately selected according to the material whose defect is corrected. For example, when the metal film 72 is chromium or the like, oxygen gas is mixed with chlorine-based gas.

  By ejecting the etching gas from the ejection part 25, the optical path of the laser light becomes an etching gas atmosphere. Then, the etching gas is irradiated with ultraviolet rays, and chlorine is excited. Therefore, photoexcited etching can be performed on the metal film 72.

  Thereby, the metal film 72 is etched in the defect 74 portion. For example, the metal film 72 is dry etched by chlorine ions or radicals. Note that the periphery of the defect 74 is masked with a resist 73. That is, the metal film 72 is protected by the resist 73 except for the defect 74 portion. Therefore, the metal film 72 can be removed with high accuracy. For example, since the chlorine radical has a long lifetime, it diffuses to the periphery of the portion irradiated with the laser beam. However, the metal film 72 is protected around the defect 74 by the resist 73. Therefore, the metal film 72 is not etched except for the defect 74. Therefore, the metal film 72 can be processed with high accuracy.

  Then, when the resist 73 is stripped using a resist stripping solution or the like, the configuration shown in FIG. As a result, the resist 73 provided on the entire surface of the substrate 71 is removed from the substrate 71. Then, the defect 74 of the metal film 72 is corrected. That is, since the metal film 72 is removed at the defect 74 portion, the black defect is corrected. Thereby, the metal film 72 pattern without a defect can be obtained.

  The metal film 72 such as aluminum has high thermal conductivity and high light reflectance. Therefore, if the metal film 72 is removed by laser irradiation, fine processing may be difficult. That is, when a defect is corrected by directly irradiating the metal film 72 with laser light, the metal film 72 having a high reflectivity is hardly given energy. Furthermore, since heat conductivity is high, thermal energy is also given to the periphery of 74 defects. The metal film 72 is also processed around the defect. For this reason, fine processing may become difficult. In this embodiment, since photoexcited etching is performed as described above, defects can be corrected with high accuracy.

  At the time of etching, the surface of the substrate 71 is covered with a resist 73. That is, the substrate 71 and the metal film 72 are protected by the resist 73. Therefore, debris and the like scattered by etching can be prevented from adhering to the surface of the substrate 71. For example, debris of the metal film 72 scattered by etching adheres to the resist. For this reason, debris is removed with resist peeling. Thereby, it is possible to prevent a new defect from occurring, and to reliably correct the defect.

  Laser ablation for removing the resist and photoexcited etching are continuously performed. This eliminates the need to move the sample 50 to an etching apparatus or the like and perform etching. Defects can also be observed in the same device. Therefore, productivity can be improved. The wavelengths used for pattern observation, resist processing, and photoexcited etching are the same. That is, these processes can be executed with laser light from one laser light source. Of course, pattern observation and defect correction may be performed with different light sources. In this case, two or more laser light sources are prepared.

  The resist 73 may not be formed on the entire surface of the substrate 71. For example, the resist 73 may be formed only on the defect 74 and its periphery. In this case, the resist 73 is dropped at the defect 74 portion.

  Next, the defect correction processing procedure will be described. First, the defect of the sample 70 is detected. The defect 74 may be provided with a defect detection function to detect the defect 74, or the defect 74 may be detected by another defect correction apparatus. A transparent resist 73 is applied on the sample. The coordinates where the defect 74 is detected are illuminated by the illumination optical system 50 described above. That is, the sample 70 is placed on the movable stage 76. Then, the movable stage 76 is driven so that the defect position is arranged on the optical axis. And it illuminates with illumination light and observes the defect 74 part. When the defect 74 is displaced from the optical axis, the optical axis of the illumination optical system 50 is aligned with the position of the defect 74. That is, the sample 70 is moved to the center of the visual field of the camera 63 using the movable stage 76.

  Specifically, illumination light having the same wavelength as the laser light is incident on the illumination optical system 50. And then. In the middle of the illumination optical system 50, the spatial distribution of illumination light is made uniform. The uniformed illumination light is incident on the sample 70 via the objective lens 43 of the illumination optical system 50. By doing so, the sample 70 is illuminated. Then, the reflected light reflected by the sample 70 through the objective lens 43 is detected, and the sample is observed. Based on the observation result of the sample 70, the defect portion of the sample 70 is aligned with the optical axis of the objective lens 43.

  Then, the optical system is switched to irradiate a correction laser beam. That is, the mirror 31 and the mirror 15 are inserted into the optical path. Thereby, the illumination optical system 50 is switched to the correction optical system 20. Note that the optical system may be switched by an optical element other than the mirror. Laser light is irradiated through the correction optical system 20. As a result, the sample 70 is irradiated with laser light through the objective lens 43. Then, the resist 73 in the defect 74 part is removed. Next, an etching gas is jetted by the jetting part 25 to make the periphery of the defect 74 an etching gas atmosphere. When laser light is irradiated in this state, the metal film 72 at the defect 74 portion is removed by etching.

  After removing the metal film 72 at the defect 74 portion, the defect 74 portion may be observed again. Thereby, it can be confirmed whether or not the defect 74 is corrected. In this case, the mirror 15 and the mirror 31 are removed from the optical path. Therefore, the correction optical system 20 is switched to the illumination optical system 50. The laser light propagates through the illumination optical system 50 and enters the sample 70. Thereby, the defective part of the sample 70 and its periphery are illuminated. Then, an image of the defective portion of the sample 70 and its periphery is acquired by the camera 63. The image acquired by the camera 63 is monitored to check whether the defect 74 has been corrected. If the defect 74 is not reliably corrected, the defect is corrected by irradiating the laser beam again in the same procedure.

  If it is confirmed that the defect has been corrected, another defect is corrected in the same manner. When all the detected defects 74 are corrected, the resist 73 is peeled off. By doing in this way, the defect 74 can be corrected reliably.

  In the above example, photoexcited etching is used to remove the metal film 72, but the removal of the metal film 72 is not limited to this. For example, dry etching or wet etching other than photo-excited etching can be used. Specifically, the metal film 72 can be processed by RIE (reactive ion etching). In this case, reactive ion etching is performed on the plurality of defects 74. That is, the resist 73 is removed by sequentially irradiating the sample 70 with a laser beam on a plurality of 74 defects. Then, the sample 70 is carried into the etching apparatus. Etching is performed with the resist 73 opened at a plurality of locations. Furthermore, instead of etching, the defect may be corrected by direct irradiation with laser light.

  Moreover, since ultraviolet light is used, defect resolution and spatial resolution of observation can be improved. Furthermore, by using the same wavelength, achromaticity becomes unnecessary. Thereby, highly accurate defect correction can be performed simply. By using the uniformizing portion 65, it is possible to prevent the resist 73 from being processed during observation. That is, since surface illumination is performed, the power density of the illumination light is lower than that of the correction laser light. The resist is not processed even when illumination light with low power density is irradiated. Therefore, the defect can be corrected with high accuracy.

  In the above description, the resist 73 is formed on the metal film 72, but a protective film other than the resist 73 may be formed. For example, an organic resin film can be formed as a protective film. The protective film is not limited to the photosensitive resin. That is, the protective film only needs to be removable by laser irradiation. For example, a material that causes a thermal decomposition reaction or a photodecomposition reaction by laser irradiation can be used. Further, since the resist 73 can be thin, it can be processed by laser ablation.

  Furthermore, an ArF excimer laser having a wavelength of 193 nm can also be used as the laser light source 11. In this case, the resist 73 can be removed not by laser ablation but by a photolysis reaction. Thereby, it can process with high precision.

  Note that the pattern to be corrected is not particularly limited. For example, a wiring pattern provided in a semiconductor device or a liquid crystal display device can be corrected. Or you may correct a defect with respect to the light shielding pattern provided in the photomask for lithography. Of course, other patterns may be modified. If the above-described defect correction is used for manufacturing the pattern substrate, the productivity of the pattern substrate can be improved. That is, a pattern is formed on the substrate by photolithography. Then, the defect of the pattern is detected and corrected as described above. Thereby, a defect can be corrected simply and reliably. Note that Embodiments 1 and 2 may be combined as appropriate.

It is a figure which shows the structure of the defect correction apparatus concerning Embodiment 1 of this invention. It is a figure which shows the structure of the defect correction apparatus concerning Embodiment 2 of this invention. It is a figure which shows the structure of the light guide member used for the defect correction apparatus concerning embodiment of this invention. It is process sectional drawing which shows the defect correction method concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Laser light source 12 Lens 13 Lens 14 Mirror 15 Mirror 15a Drive mechanism 20 Correction optical system 21 Diaphragm 22 Lens 23 Mirror 24 Slit 25 Ejection part 31 Mirror 31a Drive mechanism 32 Lens 41 PBS
42 λ / 4 plate 43 Objective lens 50 Illumination optical system 51 Galvano mirror 51a Drive mechanism 52 Two-dimensional diffraction grating 53 Lens 54 Diaphragm 55 Lens 56 Light guide member 57 Lens 58 Diaphragm 59 Lens 60 Mirror 61 Diaphragm 62 Lens 63 Camera 65 Uniform 70 Sample 71 Substrate 72 Metal film 73 Resist 74 Defect 76 Movable stage 77 Pellicle frame 78 Pellicle 81 Lamp light source 82 Interference filter

Claims (18)

A defect correcting device for correcting a defect of a pattern provided on a sample,
A correction optical system for irradiating a defective portion of the sample with a laser beam through an objective lens;
A defect correction apparatus comprising: an illumination optical system that irradiates the sample with illumination light having the same wavelength as the laser light through the objective lens so as to observe the sample.   The defect correction apparatus according to claim 1, wherein the illumination optical system includes a uniformizing unit that uniformizes an intensity distribution of the illumination light. In the illumination optical system, the laser beam used for defect correction is incident on the uniformizing unit,
The defect correction apparatus according to claim 2, wherein the sample is irradiated with light emitted from the uniformizing unit as illumination light. The uniformizing part is
A two-dimensional diffraction grating on which illumination light is incident;
A plurality of diffracted light from the two-dimensional diffraction grating is incident, and the light guide member that propagates inside while repeating the total reflection of the incident light,
The defect correction apparatus according to claim 2, further comprising a changing unit that changes an incident position of diffracted light from the two-dimensional diffraction grating on an incident end face of the light guide member.   The defect correction apparatus according to claim 4, wherein an emission end face of the light guide member is disposed at a position conjugate with the sample.   The defect correction apparatus according to claim 1, wherein the objective lens is a catadioptric objective lens. A protective film covering the pattern provided on the sample is provided,
In order to remove the protective film of the defective portion, the laser beam is irradiated,
The defect correction apparatus according to claim 1, wherein the pattern is etched through a protective film from which the defective portion has been removed. It further comprises a jet part for jetting an etching gas around the defect part,
8. The defect correcting apparatus according to claim 7, wherein the pattern is photoexcited and etched by irradiating the laser beam with the periphery of the defective portion in an etching gas atmosphere. A defect correction method for correcting a defect in a pattern provided on a sample using a laser beam,
In order to observe the sample, the step of making the illumination light having the same wavelength as the laser light enter the illumination optical system;
Illuminating the sample by causing the illumination light to enter the sample through an objective lens of the illumination optical system;
Detecting reflected light reflected by the sample through the objective lens and observing the sample;
Irradiating the sample with the laser light through the objective lens. Further comprising the step of homogenizing the spatial distribution of the illumination light in the middle of the illumination optical system,
The defect correction method according to claim 9, wherein the sample is illuminated by causing the uniformed illumination light to enter the sample via an objective lens of the illumination optical system.   The defect correction method according to claim 10, wherein the illumination of the sample and the defect correction are performed by laser light from the same laser light source. In the step of uniforming the spatial distribution of the illumination light,
The illumination light is incident on a two-dimensional diffraction grating,
A plurality of diffracted lights from the two-dimensional diffraction grating are incident on a light guide member,
The light propagated while repeating the total reflected light inside the light guide member is emitted from the light guide member,
The defect correction method according to claim 10 or 11, wherein an incident position of diffracted light from the two-dimensional diffraction grating on an incident end face of the light guide member is changed.   The defect correction method according to claim 12, wherein an emission end face of the light guide member is disposed at a position conjugate with the sample. Forming a protective film covering the pattern provided on the sample;
In order to remove the protective film of the defective portion, the sample is irradiated with the laser light,
The defect correction method according to claim 9, wherein the pattern is etched using the protective film from which the defective portion has been removed as a mask. Etching an etching gas around the defective portion,
The defect correction method according to claim 14, wherein the pattern is photoexcited by irradiating the laser beam in a state where the periphery of the defect portion is in an etching gas atmosphere. A defect correction method for correcting defects in a pattern provided on a sample by irradiating the sample with laser light,
Irradiating a protective film provided on the pattern with a laser beam to remove the protective film in a defective portion;
Supplying the etching gas to the sample from which the protective film has been removed;
Irradiating the sample with laser light in the etching gas atmosphere to photoexcite and etch the pattern of the portion from which the protective film has been removed.   The defect correction method according to claim 15 or 16, wherein the laser beam irradiation for removing the protective film and the laser beam irradiation for etching the pattern are continuously performed. Forming a pattern on the sample,
Detecting pattern defects on the sample;
The manufacturing method of the pattern board | substrate which corrects a defect with the defect correction method of any one of Claims 9 thru | or 17.

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