Halftone mask defect repair equipment

Abstract

To provide a defect correction device for a half tone mask capable of improving, uniformity of a film thickness of a correction film, therefore acquiring a high quality correction film without unevenness in a transmission factor.SOLUTION: A defect correction device for a half tone mask comprises: a laser beam emission device 21; a beam expander 23 for expanding a beam diameter of the laser beam; an optical member 28 which has an optical action part 28b for reducing peak intensity in a center axis of the laser beam; a beam scan unit 25 for scanning the laser beam which passed through the beam expander 23 and the optical member 28 using a spatial light modulation element, for planarly radiating the laser beam to a defect correction object region of the half tone mask; and a gas supply system for making the defect correction object region a raw material gas atmosphere being a raw material of the correction film.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a defect repair device for a half-tone mask that repairs a defect occurring in a semi-transparent portion of a half-tone mask. [Background technology]

[0002] Halftone masks are known as a photolithography technology. Halftone masks have semi-transmitting sections with a transmittance between that of the transmitting section and the light-shielding section, enabling multiple tones (three or more tones) to be achieved by combining two tones (white gradations in the transmitting section and black gradations in the light-shielding section) with intermediate tones (gray tones) between white and black in the semi-transmitting section. Therefore, they are also called multi-tone photomasks. By using a halftone mask, patterns with different exposure amounts can be formed in the photoresist with a single exposure. This reduces the number of photomasks used, the number of manufacturing processes, and ultimately the manufacturing costs.

[0003] Here, in half-tone masks, problems in the manufacturing process or the like can cause two main types of defects. One is a defect in which a defect exists in part of the semi-transparent portion (the presence of a defect increases the transmittance, so this is called a "white defect"). The other is a defect in which an excess or foreign matter exists in part of the semi-transparent portion (the presence of foreign matter decreases the transmittance, so this is called a "black defect").

[0004] When such defects occur, they must be repaired. In the case of white defects, they are repaired by forming a repair film on the defective area. In the case of black defects, they are repaired by removing the foreign matter or the part of the semi-transparent area where the foreign matter is present, and then forming a new repair film as necessary.

[0005] A known defect repair device is described in Patent Document 1. This device forms a repair film using a laser CVD (Chemical Vapor Deposition) method. That is, this device forms a CVD repair film by passing a laser beam emitted from a laser oscillator through an aperture, converging it with an objective lens, and irradiating the laser beam onto the surface of a photomask to be repaired, which is placed in a reactive gas atmosphere. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-173670 Summary of the Invention [Problem to be solved by the invention]

[0007] The defect repair device described in Patent Document 1 forms a repair film large enough to fill the defect repair area by forming multiple unit repair films in a two-dimensional array at a pitch where adjacent films overlap. However, due to the intensity distribution (Gaussian distribution) of the laser beam, the unit repair film has a convex shape with a thin film thickness at the periphery and a thick film thickness at the center. This makes it easy for the film thickness of the repair film to become uneven beyond the allowable range, which in turn makes it easy for the transmittance of the repair film to become uneven.

[0008] Therefore, the present invention has been made in consideration of the above circumstances, and has as its object to provide a defect repair device for a half-tone mask that can improve the uniformity of the film thickness of the repair film, thereby obtaining a high-quality repair film with no unevenness in transmittance. [Means for solving the problem]

[0009] The apparatus for repairing a defect in a half-tone mask according to the present invention comprises: a stage on which a half-tone mask is placed; a laser beam emitting device; an optical member having an optical action portion having a shape larger than the beam diameter of the laser beam, the optical action portion reducing the peak intensity at the central axis of the laser beam passing through the optical action portion; a beam expander that expands the beam diameter of the laser beam; a beam scanning unit that uses a spatial light modulation element to scan the laser beam that has passed through the beam expander and the optical member, thereby irradiating the laser beam onto a defect correction target area of ​​the halftone mask in a planar manner; a gas supply system for supplying a source gas atmosphere for the defect repair target area, the source gas atmosphere being a raw material for the repair film; This is a defect repair device for halftone masks.

[0010] Here, as one aspect of the half-tone mask defect repair device according to the present invention, The optical action portion has at least one of a filtering action that makes the rate of decrease in intensity of the portion of the laser beam that passes through the center of the optical action portion higher than the rate of decrease in intensity of the portion of the laser beam that passes through the peripheral portion of the optical action portion, or a diffusing action that diffuses the laser beam. The above configuration can be adopted. In another aspect of the half-tone mask defect repair device according to the present invention, The optical action portion is a cloudy portion formed by clouding part of the surface of the transparent member. The above configuration can be adopted.

[0011] In addition, as another aspect of the halftone mask defect repair device according to the present invention, The defect repair target area of ​​the half-tone mask is set for defects of 20 μm or less in size. The above configuration can be adopted. In still another aspect of the halftone mask defect repair device according to the present invention, a glass plate covering an outlet opening of a housing of the laser beam emitting device; The optical member is a glass plate provided separately from this glass plate. The above configuration can be adopted.

[0012] In addition, as another aspect of the halftone mask defect repair device according to the present invention, The optical element may further include an optical element support device that supports the optical element so that its position can be adjusted relative to the center of the optical path in a plane perpendicular to the optical path of the laser beam. The above configuration can be adopted. [Effects of the Invention]

[0013] According to the present invention, the laser beam emitted from the laser beam emitter is expanded in beam diameter by the beam expander, and the peak intensity at the central axis is reduced by the optical action portion of the optical member, so that the laser beam is irradiated in a planar manner onto the defect repair target area of ​​the half-tone mask in an overall smoothed state. Therefore, according to the present invention, the uniformity of the film thickness of the repair film can be improved, and thereby a high-quality repair film with uniform transmittance can be obtained. [Brief explanation of the drawings]

[0014] [Figure 1] 1(a) is a schematic diagram of a defect correction device for a half-tone mask according to one embodiment, and FIGS. 1(b) and 1(c) are schematic diagrams of slits in the defect correction device. [Figure 2] Fig. 2(a) is a schematic diagram of the laser optical system of the defect repair device. Fig. 2(b) is a plan view of an optical element used in the laser optical system. Fig. 2(c) is an explanatory diagram of one example of the optical characteristics of the optical element. Fig. 2(d) is an explanatory diagram of another example of the optical characteristics of the optical element. [Figure 3] Figure 3(a) is a plan view of the optical element support device, and Figure 3(b) is a side view of the optical element support device. [Figure 4] Figure 4(a) is a front view of the optical element support device, and Figure 4(b) is a front view of the optical element support device with the support base for the optical element removed. [Figure 5] 5(a) to 5(d) are explanatory diagrams of a method for repairing a defect in a halftone mask. [Figure 6] Fig. 6(a) is an explanatory diagram of a film formation image when no optical member is used, and Fig. 6(b) is an explanatory diagram of a film formation image when an optical member is used. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a defect repair device for a half-tone mask according to an embodiment and a defect repair method for a half-tone mask using the same will be described with reference to FIGS.

[0016] <Defect repair equipment> First, the defect repair device will be described. As shown in Fig. 1(a), the defect repair device 10 is a device that forms a repair film (CVD film) using a laser CVD method. The defect repair device 10 mainly includes a laser optical system 20, a laser optical system 30, an optical system 40, a gas supply system 50, and a position control system 60.

[0017] The laser optical system 20 is a laser optical system for forming a repair film. The laser optical system 20 includes a laser oscillator (CVD laser) 21, a shutter 22, a beam expander 23, an attenuator 24, and a beam scanning unit 25. The laser beam (laser light) emitted from the laser oscillator 21, which serves as a laser beam emitting device, has its beam diameter expanded by the beam expander 23, and is adjusted to an appropriate output by the attenuator 24, and then scanned by the beam scanning unit 25. The beam scanning unit 25 performs main scanning and sub-scanning using a reflective or transmissive spatial light modulation element such as a galvanometer mirror, a digital micromirror device (DMD), or a PLZT element.

[0018] The laser optical system 20 is shown in more detail in FIG. 2( a). The laser optical system 20 further includes a glass plate 26, a mirror 27, and an optical member 28. The glass plate 26 covers the open exit of the housing of the laser oscillator 21 to prevent dust and other particles from entering the housing. A change in temperature inside the housing of the laser oscillator 21 changes the optical axis, affecting wavelength conversion of the laser beam, but the glass plate 26 also serves to maintain a constant temperature inside the housing of the laser oscillator 21. A pair of mirrors 27 is provided between the shutter 22 and the beam expander 23. The pair of mirrors 27 bends the optical path at right angles at two locations, so that the central axis of the laser beam emitted from the laser oscillator 21 and the central axis of the scanning light emitted from the beam scan unit 25 are parallel to each other and in opposite directions. The mirror 27 is provided in consideration of the layout of the laser optical system 20 and may not be necessary depending on the layout of the laser optical system 20.

[0019] The optical member 28 has an optical action portion that reduces the peak intensity at the central axis of the laser beam, and is disposed on the optical path between the pair of mirrors 27, 27. More specifically, the optical member 28 is disposed between the pair of mirrors 27, 27 so that the center of the optical action portion coincides with the center of the optical path.

[0020] As shown in FIG. 2(b), the optical action portion is a cloudy portion 28b formed on the surface of glass plate 28a. Glass plate 28a is circular. Cloudy portion 28b is also circular. Cloudy portion 28b is larger than or the same size as the beam diameter of the laser beam. For example, while the beam diameter (diameter) of the laser beam is 1 mm to 2 mm, cloudy portion 28b is 1.5 mm to 2 mm, and has a size that is 70% to 100% of the beam diameter of the laser beam. This allows the laser beam to pass through cloudy portion 28b. Note that the size of cloudy portion 28b refers to the average width of cloudy portion 28b.

[0021] The opaque portion 28b can be formed in various forms. For example, as shown in FIG. 2(c), the opaque portion 28b is formed by surface-processing a portion of the surface of the glass plate 28a to have a transmittance gradient in which the transmittance is lower in the center than in the periphery and higher in the periphery than in the center. This allows the opaque portion 28b to have a filtering effect that increases the intensity reduction rate of the portion of the laser beam passing through the center of the opaque portion 28b compared to the intensity reduction rate of the portion of the laser beam passing through the periphery of the opaque portion 28b. Alternatively, as shown in FIG. 2(d), the opaque portion 28b is formed by surface-processing a portion of the surface of the glass plate 28a to have a rough surface, such as an uneven or jagged surface. This allows the opaque portion 28b to have a diffusing effect that diffuses the laser beam.

[0022] The optical element 28 is supported by an optical element support device 7 shown in Figures 3 and 4. The optical element support device 7 is disposed between a pair of mirrors 27, 27, and is attached to a mounting base 11 that directly or indirectly mounts components of the laser optical system 20, such as the pair of mirrors 27, 27 and the laser oscillator 21.

[0023] The optical element support device 7 includes a fixed base 70 , a first linear guide 71 , a first slide base 72 , a second linear guide 73 , a second slide base 74 , and a support base 75 .

[0024] The fixed base 70 has a vertical plate shape and is attached (at its lower part) to the mounting base 11. The fixed base 70 has an opening 70a (in its lower half region) that penetrates from front to back and is centered on the center C of the optical path. The first linear guide 71 is attached to the fixed base 70 (in its upper half region) so that the longitudinal direction of the first linear guide 71 is aligned along one axial direction (e.g., the horizontal direction) of two orthogonal axes in an orthogonal plane perpendicular to the optical path. The first slide base 72 is attached to the first linear guide 71 and is slidable in one axial direction (e.g., the horizontal direction). The second linear guide 73 is attached to the first slide base 72 so that the longitudinal direction of the second linear guide 73 is aligned along the other axial direction (e.g., the vertical direction). The second slide base 74 is attached to the second linear guide 73 and is slidable in the other axial direction (e.g., the vertical direction).

[0025] The support base 75 is in the form of a vertical plate, and is attached to the second slide base 74 (at its upper half region) so as to face the fixed base 70. The support base 75 has an opening 75a that penetrates from front to back and is coaxial with the opening 70a of the fixed base 70. The opening 75a is a circular hole of the same size as the glass plate 28a of the optical element 28, and by fitting the optical element 28 into this opening 75a, the support base 75 supports the optical element 28 (at its lower half region). With this configuration, the optical element 28 is movable in a plane perpendicular to the optical path.

[0026] The optical element support device 7 includes a first micrometer 76. The first micrometer 76 has a main body 76a attached to the fixed base 70 via a first mounting member 77, and is disposed along the sliding direction of the first slide base 72. The tip of a spindle 76b of the first micrometer 76 is rotatably engaged with an engaging portion 72a that is part of the first slide base 72. With this configuration, by rotating the first micrometer 76, it is possible to adjust the position of the optical element 28 in one axial direction (for example, the horizontal direction) of two orthogonal axes in a plane orthogonal to the optical path.

[0027] The optical element support device 7 includes a second micrometer 78. The second micrometer 78 has a main body 78a attached to the first slide base 72 via a second mounting member 79, and is disposed along the sliding direction of the second slide base 74. The tip of the spindle 78b of the second micrometer 78 is rotatably engaged with an engaging portion 74a that is part of the second slide base 74. With this configuration, by rotating the second micrometer 78, it is possible to adjust the position of the optical element 28 in the other axial direction (for example, the vertical direction) of two orthogonal axes in a plane orthogonal to the optical path.

[0028] With the above configuration, the position of the optical member 28 can be adjusted with respect to the center C of the optical path in a plane perpendicular to the optical path. As a result, the opaque portion 28b of the optical member 28 is positioned so that the center of the opaque portion 28b coincides with the center C of the optical path.

[0029] 1(a), the laser optical system 30 is a laser optical system for partially removing the semi-transparent film that constitutes the semi-transparent portion. The laser optical system 30 includes a laser oscillator (Zap Laser) 31, a shutter 32, a beam expander 33, and an attenuator 34. The laser beam (laser light) emitted in pulses from the laser oscillator 31 has its beam diameter expanded by the beam expander 33, and is adjusted to an appropriate output by the attenuator 34.

[0030] The optical system 40 guides the laser beams emitted from the laser optical systems 20 and 30 onto the surface of the halftone mask 8. The optical system 40 includes a prism 41, a prism 42, a slit 43, a prism 44, a prism 45, and an objective lens 46. The prism 41 reflects the laser beam emitted from the laser optical system 20. The prism 42 transmits the laser beam reflected by the prism 41 and reflects the laser beam emitted from the laser optical system 30. The slit 43 narrows the beam diameter of the laser beam transmitted through the prism 42 and the laser beam reflected by the prism 42 to a predetermined size. The laser beam passing through the slit 43 is reflected by the prisms 44 and 45, passes through the objective lens 46, and is irradiated onto the surface of the halftone mask 8 placed on the stage 61.

[0031] The slit 43 defines a laser beam irradiation area on the surface of the halftone mask 8. As shown in FIGS. 1(b) and 1(c), the slit 43 includes a first pair of frames 430, 430 that are parallel to each other and whose spacing is adjustable, and a second pair of frames 431, 431 that are also parallel to each other and whose spacing is adjustable and that are perpendicular to the first pair of frames 430, 430. A rectangular opening 432 (hatched area in the figure) surrounded by the four mutually perpendicular frames 430, 430, 431, 431 becomes the laser beam irradiation area. The opening 432 can also be slit-shaped by narrowing the spacing between one pair of frames.

[0032] The gas supply system 50 supplies the source gas that is the raw material for the repair film. The gas supply system 50 includes a source gas supply pipe 51. The source gas is generated by mixing a carrier gas consisting of an inert gas with a source gas that has been gasified by heating. The source gas supplied from the source gas supply pipe 51 is ejected toward the surface of the half-tone mask 8, creating a source gas atmosphere in the defect repair target area on the surface of the half-tone mask 8. In this source gas atmosphere, a laser beam from the laser optical system 20 is irradiated onto the surface of the half-tone mask 8, forming an irradiation spot, and a repair film is formed according to the size and shape of the irradiation spot. Examples of the source gas include metal carbonyls such as chromium carbonyl, molybdenum carbonyl, and tungsten carbonyl.

[0033] The position control system 60 is used to position the portion of the half-tone mask 8 to be irradiated with laser light at the laser irradiation position (on the central axis of the objective lens 46). The position control system 60 includes a stage 61 and a position control unit 62. The half-tone mask 8 is placed on the stage 61, which is movable in the X and Y directions that are perpendicular to each other on a horizontal plane. The position control unit 62 controls the movement and position of the stage 61.

[0034] The mechanism for changing the relative position of the laser irradiation position and the halftone mask 8 may be a mechanism for moving the stage 61 in the X and Y directions, or may be (i) a mechanism in which the stage is fixed and a head unit equipped with a laser irradiation unit (objective lens) moves in the X and Y directions, or (ii) a mechanism in which one of the head unit and the stage moves in the X direction and the other moves in the Y direction.

[0035] <Defect correction method> Next, a defect repair method will be described. The defect repair method is used when the size of the defect is 20 μm or less, that is, when the size of the defect is within a square of 20 μm × 20 μm or less, and generally includes, as shown in Fig. 5, (i) a trimming step (first step) for setting a defect repair target area 4 that encompasses a defect 3 generated in a semi-transparent portion 2 of a half-tone mask 8 and removing the existing semi-transparent film 2 that exists within the defect repair target area 4, and (ii) a repair film deposition step for depositing a repair film 7 in the defect repair target area 4 so that the transmittance is equal to that of the semi-transparent portion 2 and in a shape that matches the defect repair target area 4. The correction film deposition process also includes (ii-i) a base layer deposition process (second process) for depositing a base layer 5 having a transmittance higher than that of the semi-transparent section 2, and (ii-ii) a transmittance adjustment layer deposition process (third process) for depositing one or more transmittance adjustment layers 6 on the base layer 5 so that the transmittance is equal to that of the semi-transparent section 2.

[0036] In the first step (trimming step), the opening shape of the slit 43 of the defect correction device 10 is aligned with the defect correction target area 4, and the existing semi-transparent film 2 existing in the defect correction target area 4 is removed using the laser optical system 30. As a result, the defect 3 disappears, and a non-film-formed portion with a rectangular outline is formed, i.e., a transparent portion where the transparent substrate 1 is exposed in a rectangular shape.

[0037] In the second process (base layer deposition process of the repair film deposition process), the opening shape of the slit 43 of the defect repair device 10 is aligned with the optical center of the beam scan unit 25 (the center of the galvanometer mirror in the case of a galvanometer mirror), and the opening shape of the slit 43 is aligned with the defect repair target area 4. With this in mind, a base layer 5 is formed in the defect repair target area 4 using the laser optical system 20. The base layer 5 is deposited by main-scanning and sub-scanning the laser beam using the beam scan unit 25 while continuously irradiating the laser beam. The base layer 5 is formed in a rectangular shape corresponding to the opening shape of the slit 43 of the defect repair device 10.

[0038] As described above, the base layer 5 is a CVD film. The transmittance of the base layer 5 is higher than that of the semi-transparent portion 2. This is because the transmittance of the correction film 7 is adjusted by laminating a transmittance adjustment layer 6 to decrease the transmittance. The transmittance of the base layer 5 is preferably set to be greater than or equal to +10% and less than or equal to +20% of the transmittance of the semi-transparent portion 2. In this embodiment, the transmittance of the semi-transparent portion 2 is 30%, while the transmittance of the base layer 5 is 40%.

[0039] In the third process (transmittance adjustment layer deposition process of the repair film deposition process), the opening shape of the slit 43 of the defect repair device 10 is aligned with the optical center of the beam scan unit 25 (the center of the galvanometer mirror in the case of a galvanometer mirror), and the opening shape of the slit 43 is aligned with the defect repair target area 4, and then the laser optical system 20 is used to form the transmittance adjustment layer 6 in the defect repair target area 4. As with the base layer 5, the transmittance adjustment layer 6 is deposited by continuously irradiating the laser beam while main-scanning and sub-scanning the laser beam using the beam scan unit 25. The transmittance adjustment layer 6 is formed in a rectangular shape corresponding to the opening shape of the slit 43 of the defect repair device 10.

[0040] In the transmittance adjustment layer deposition process, the transmittance of the correction film 7 is measured every time the transmittance adjustment layer 6 is deposited. As a transmittance measurement method, various known transmittance measurement methods can be used, such as a method of directly measuring the transmittance by irradiating light (for example, at one point in the center of the correction film 7) and measuring the amount of transmitted light, as well as a method of indirectly measuring the transmittance by capturing an image of the correction film 7 (for example, its pixel values) and comparing an image of the semi-transparent portion 2 (for example, its pixel values).

[0041] When the measurement results show that the transmittance of the correction film 7 is the same as that of the semi-transparent section 2, or the difference between the transmittance of the correction film 7 and that of the semi-transparent section 2 is negligible, the transmittance adjustment layer deposition process, and ultimately the correction film deposition process, is completed.

[0042] Through the above steps, a repair film 7 is obtained that has a uniform transmittance over the entire surface of the defect correction target region 4 and that is equal to the transmittance of the semi-transparent portion 2 that is made up of a normal semi-transparent film around the defect correction target region 4. Note that, in order to obtain a repair film 7 of higher quality, if necessary, a compensation film formation process may be performed as described in Japanese Patent No. 6741893, in which a compensation film is formed in a high transmittance portion that remains in the defect correction target region 4 even after the formation of the repair film 7, so that the transmittance becomes equal to the transmittance of the semi-transparent portion 2.

[0043] If the defect occurs in the semi-transmitting portion near the boundary between the semi-transmitting portion and the transmitting portion, trimming may be performed with the slit 43 aligned so that it forms a U-shape connected to the transmitting portion, or with the slit 43 rotated by a predetermined angle so that it forms a substantially triangular shape. In the latter case, trimming may be performed with the rotation angle of the slit 43 aligned, and repair film 7 formed, and the repair film 7 protruding from the edge line of the semi-transmitting portion may be removed using laser optical system 30.

[0044] <Effects of this embodiment> As described above, the opaque portion 28b of the optical member 28 has a filtering effect that makes the intensity reduction rate of the laser beam passing through the center of the opaque portion 28b higher than the intensity reduction rate of the laser beam passing through the peripheral portion of the opaque portion 28b, or a diffusing effect that diffuses the laser beam. As a result, as shown in Figure 6(b), the laser beam irradiated on a surface by the main scanning and sub-scanning of the beam scanning unit 25 is smoothed overall. This improves the uniformity of the film thickness of the repair film 7, thereby enabling a high-quality repair film 7 with uniform transmittance.

[0045] Furthermore, the optical element 28 is supported by a support base 75 of the optical element support device 7, which is movable on two orthogonal axes in a plane orthogonal to the optical path, and is movable in the plane orthogonal to the optical path. This allows the position of the optical element 28 to be adjusted with respect to the center C of the optical path in the plane orthogonal to the optical path.

[0046] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0047] In the above embodiment, the optical member 28 is disposed between the pair of mirrors 27, 27 in the laser optical system 20. However, the present invention is not limited to this. The optical member can be disposed anywhere on the optical path from the laser oscillator (or shutter) to the beam expander. Alternatively, the optical member may also serve as a glass plate covering the outlet opening of the housing of the laser oscillator.

[0048] Furthermore, in the above embodiment, the optical action portion (opaque portion 28b) is provided on a portion of the surface of the glass plate 28a of the optical member 28. However, the present invention is not limited to this. The optical action portion (opaque portion) may be provided on the entire surface of the glass plate. Furthermore, in the above embodiment, the optical member is constructed using a glass plate. However, the present invention is not limited to this. The optical member may be a transparent member of another form, such as a transparent resin plate.

[0049] Although the above embodiment describes the repair of a white defect, the defect to be repaired may also be a black defect.

[0050] In the above embodiment, the defect correction target area 4 and the trimming area are rectangular due to the structure of the slit 43 of the defect correction device 10. However, by adopting an appropriate mask shape, the defect correction target area and the trimming area can be set to any appropriate shape. Alternatively, by appropriately controlling the laser beam, it is also possible to form a repair film without using a slit.

[0051] In the above embodiment, a trimming step is performed. However, depending on the shape of the defect, the defect itself may be set as the defect correction target area. In this case, the trimming step is not necessary.

[0052] In the above embodiment, the repair film deposition step includes a base layer deposition step and a transmittance adjustment layer deposition step. However, if the desired repair film can be obtained using only the base layer, the transmittance adjustment layer deposition step is not necessary. [Explanation of symbols]

[0053] 1...transparent substrate (glass substrate), 2...semi-transparent film (semi-transparent portion), 3...defect (white defect), 4...trimming area (area to be repaired defect), 5...base layer, 6...transmittance adjustment layer, 7...repair film, 8...halftone mask, 10...defect repair device, 11...mounting base, 20...laser optical system, 21...laser oscillator, 22...shutter, 23...beam expander, 24...attenuator, 25...beam scan unit, 26...glass plate, 27...mirror, 28...optical member, 28a...glass plate, 28b...opaque portion, 30...laser optical system, 31...laser oscillator, 32...shutter, 33...beam expander, 34...attenuator, 40...optical system, 41...prism, 42...prism, 43...slit, 43 0...frame, 431...frame, 432...aperture, 44...prism, 45...prism, 46...objective lens, 50...gas supply system, 51...raw material gas supply pipe, 60...position control system, 61...stage, 62...position control unit, 7...optical element support device, 70...fixed base, 70a...aperture, 71...first linear guide, 72...first slide base, 72a...engagement portion, 73...second linear guide, 74...second slide base, 74a...engagement portion, 75...support base, 75a...aperture, 76...first micrometer, 76a...main body, 76b...spindle, 77...first mounting member, 78...second micrometer, 78a...main body, 78b...spindle, 79...second mounting member, S...defect size, C...center of optical path

Claims

1. a stage on which a half-tone mask is placed; a laser beam emitting device; an optical member having an optical action portion having a shape larger than the beam diameter of the laser beam, the optical action portion reducing the peak intensity at the central axis of the laser beam passing through the optical action portion; a beam expander that expands the beam diameter of the laser beam; a beam scanning unit that uses a spatial light modulation element to scan the laser beam that has passed through the beam expander and the optical member, thereby irradiating the laser beam onto a defect correction target area of ​​the halftone mask in a planar manner; a gas supply system for supplying a source gas atmosphere for the defect repair target area, the source gas atmosphere being a raw material for the repair film; Halftone mask defect repair equipment.

2. The optical action portion has at least one of a filtering action that makes the rate of decrease in intensity of the portion of the laser beam that passes through the center of the optical action portion higher than the rate of decrease in intensity of the portion of the laser beam that passes through the peripheral portion of the optical action portion, or a diffusing action that diffuses the laser beam.

2. The apparatus for repairing a defect in a half-tone mask according to claim 1.

3. The optical action portion is a cloudy portion formed by clouding part of the surface of the transparent member.

3. The apparatus for repairing a defect in a half-tone mask according to claim 1.

4. The defect repair target area of ​​the halftone mask is set for defects of 20 μm or less in size.

4. The apparatus for repairing a defect in a half-tone mask according to claim 1.

5. A glass plate covering an outlet opening of a housing of a laser beam emitting device, The optical member is a glass plate provided separately from this glass plate.

5. The apparatus for repairing a defect in a half-tone mask according to claim 1.

6. The optical element may further include an optical element support device that supports the optical element so that its position can be adjusted relative to the center of the optical path in a plane perpendicular to the optical path of the laser beam.

6. The apparatus for repairing a defect in a half-tone mask according to claim 1.

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