Ablation processing method, laser processing apparatus, and ablation processing mask

Abstract

To provide a mask design and a laser processing method capable of appropriately forming a processing pattern on a substrate or the like while repeatedly scanning a line-shaped beam, in ablation processing.SOLUTION: In a processing device 100, a mask M formed with mask patterns P1 to P4 is placed on a mask stage 40. By moving a line beam formation part 20 and changing an angle of an angle changing mirror 26, a line-shaped beam LB is scanned in a main scanning direction (X direction) and an irradiation position of the line-shaped beam LB is shifted in a sub-scanning direction (Y direction). By moving the mask M by moving the mask stage 40, the irradiation position of the line-shaped beam LB is aligned to the positions of scanning regions MR1 to MR4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laser processing apparatus and a processing method for forming a pattern by ablating a substrate or the like using light with a high energy density such as ultraviolet laser light.

Background Art

[0002] As a method for forming a pattern with high precision on a printed wiring board or the like, ablation processing is known. In this method, a laser with a high energy density such as an excimer laser is irradiated onto a mask and projected onto a substrate or the like. By instantaneously removing the material surface according to the mask pattern, vias, grooves for wiring, etc. can be formed on a laminated substrate or the like.

[0003] In a laser processing apparatus for ablation processing, the light oscillated from the laser is shaped into a line shape. For example, for a fixed laser beam, by synchronously moving a mask having a pattern corresponding to vias, grooves, etc. and a stage on which a substrate is mounted, the mask pattern is drawn on the substrate (see, for example, Patent Document 1). Alternatively, by moving an optical system for forming a line beam in the scanning direction with respect to the mask, a processing pattern is formed on the substrate (see Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The pattern size in the mask is determined according to the size of the processing area defined on the substrate, the energy density of the laser beam, and the characteristics of the optical system, such as the reduction ratio of the projection optical system. Therefore, for mask patterns that exceed the width of the line of light, the processing is performed on the processing area of ​​the substrate by scanning the line of light multiple times.

[0006] In this case, to prevent processing defects caused by insufficient fluence (light intensity per unit area) due to misalignment of the irradiation position at the connection points between line-shaped beams, it is necessary to scan the line-shaped beams while overlapping them.

[0007] However, even if the fluence magnitude and number of irradiations are adjusted for the overlapping area to make the total fluence equal, the shape of patterns such as vias and grooves may differ between the overlapping and non-overlapping areas.

[0008] Therefore, in ablation processing, there is a need to provide a mask design and laser processing method that can appropriately form a processing pattern on a substrate or the like while repeatedly scanning it with a line-shaped light. [Means for solving the problem]

[0009] This invention focuses on an ablation processing method that involves overlapping scanning of line-shaped light, as well as ablation processing masks and laser processing equipment that can be used in such processing methods.

[0010] One aspect of the present invention is an ablation processing method in which a line beam forming optical system shapes light emitted from a laser into a line shape, guides the line shape of light to an ablation processing mask, and performs ablation processing on a processing area of ​​a substrate by overlap scanning the line shape of light.

[0011] Here, "overlapping scanning of line-shaped light" refers to a scanning process where, when viewed from the scanning width direction (sub-scanning direction), adjacent scanning regions along the scanning width direction partially overlap. Whether or not the scanning regions of the line-shaped light in the mask actually partially overlap is irrelevant.

[0012] In one embodiment of the present invention, an ablation processing method is performed based on a single mask. Specifically, a single mask is used to define multiple strip-shaped scanning regions having a line-shaped light scanning width, spaced apart from each other in the scanning direction (main scanning direction). A mask pattern (referred to here as multiple divided mask patterns) is formed on the single mask by dividing the mask pattern of the processing region according to the multiple strip-shaped scanning regions. Line-shaped light is then scanned through the multiple strip-shaped scanning regions.

[0013] Here, "separating multiple strip-shaped scanning regions from each other in the scanning direction" means that adjacent strip-shaped scanning regions in the scanning width direction are separated by a predetermined distance in the scanning direction so that there are no overlapping portions along the scanning width direction; that is, a predetermined space exists in the scanning direction between the end of one strip-shaped scanning region and the end of the other strip-shaped scanning region.

[0014] On the other hand, in another aspect of the present invention, the ablation processing method is performed based on multiple masks. That is, multiple strip-shaped scanning regions having a scanning width for line-shaped light are defined for multiple masks, and multiple divided mask patterns are formed on the multiple masks by dividing the mask pattern of the processing region according to the multiple strip-shaped scanning regions. Then, while exchanging the multiple masks, line-shaped light is scanned through the multiple strip-shaped scanning regions.

[0015] There are various configurations for forming multiple subdivision mask patterns on multiple masks, and the number of masks and the number of subdivision mask patterns formed on each mask are arbitrary. For example, it is possible to form one subdivision mask pattern for each mask. On the other hand, it is also possible to form at least two subdivision mask patterns on at least one mask among multiple masks. For example, it is possible to prepare multiple masks (e.g., two) to match the number of subdivision mask patterns to be formed (e.g., four), and form the same number (e.g., two) subdivision mask patterns on each mask.

[0016] The configuration for scanning a line of light across multiple strip-shaped scanning regions can be determined according to the configuration of the laser processing apparatus. For example, by moving the line beam forming optical system in the scanning direction, a line of light can be scanned in the scanning direction (main scanning direction) relative to a mask placed on a mask stage. Alternatively, by moving the mask stage, it is possible to scan the line of light along the strip-shaped regions of the divided mask pattern.

[0017] On the other hand, a configuration that moves the strip-shaped scanning region of multiple divided mask patterns to the next strip-shaped scanning region can be achieved by moving the mask stage. Alternatively, it can be achieved by the synchronized movement of the processing stage on which the substrate is placed and the line beam forming optical system. This moves the irradiation position of the line-shaped light to align with the scanning start position of the strip-shaped scanning region of the divided mask pattern.

[0018] For example, scanning of a strip-shaped region of a divided mask pattern along the main scanning direction is performed by moving the line beamforming optical system, and the alignment of the irradiation position of the line-shaped light from one divided mask pattern to the next, which is the scanning order, is performed by moving the mask stage in the scanning direction and moving the line beamforming optical system in the sub-scanning direction.

[0019] The scanning order and scanning method for multiple divided mask patterns can be determined separately for the use of a single mask and for the use of multiple masks, or they can be determined in the same way. For example, in the case of a single mask, line-shaped light is scanned in an overlapping manner according to the order in which the multiple divided mask patterns are arranged along the scanning width direction.

[0020] When using multiple masks, it is possible to sequentially scan the strip-shaped scanning areas of the divided mask patterns formed on each mask with a linear beam of light. For example, if a predetermined number of divided mask patterns are formed on each of the multiple masks, it is possible to sequentially scan the strip-shaped scanning areas of the divided mask patterns formed on each mask with a linear beam of light; that is, after scanning the strip-shaped scanning area of ​​the divided mask pattern formed on one mask is completed, scanning for the next mask can be performed.

[0021] In contrast to the ablation processing method described above, the present invention can provide an ablation processing mask configured as a single mask. One embodiment of the present invention is a single ablation processing mask in which a plurality of divided mask patterns are formed on a processing area of ​​a substrate, with the mask pattern of the processing area divided according to the strip-shaped scanning area, which is determined according to the scanning width of the line-shaped light formed by the line beam forming optical system of a laser processing apparatus, and the plurality of divided mask patterns are separated from each other along the scanning direction.

[0022] The formation positions of the divided mask patterns formed on a single mask can be set in various ways, within the range that satisfies the above-mentioned configuration of being "separated from each other along the scanning direction." For example, multiple divided mask patterns can be formed in a staggered pattern, for example, so as to be arranged regularly and at equal intervals with respect to the scanning direction (main scanning direction) and / or the scanning width direction (sub-scanning direction).

[0023] In addition, in the present invention, an ablation processing mask configured as a plurality of masks can be provided. The ablation processing mask according to one aspect of the present invention forms a plurality of divided mask patterns obtained by dividing the mask pattern of the processing region according to a plurality of strip-shaped scanning regions determined according to the scanning width of the line-shaped light formed by the line beam forming optical system of the laser processing apparatus with respect to the processing region of the substrate, and is a plurality of ablation processing masks. The divided mask patterns adjacent to each other in the scanning width direction are formed on different masks.

[0024] The shapes, sizes, etc. between the plurality of masks vary. For example, they can be defined to have the same shape and size, or can have different shapes and sizes. In each mask, it can be configured such that the distances from the mask reference position (for example, one edge or four corners of the mask) of the divided mask pattern scanned first are equal.

[0025] Note that in the ablation processing mask composed of a single mask or a plurality of masks, it is possible to solve the technical problems of the present invention regardless of the above-described overlap scanning.

[0026] In the present invention, a laser processing apparatus for realizing the above-described ablation processing method can be provided. The laser processing apparatus according to one aspect of the present invention includes a line beam forming optical system that shapes the light oscillated from the laser into a line shape, a scanning unit that scans the line-shaped light in the scanning direction by moving the line beam forming optical system, a processing stage moving unit that moves a processing stage on which a substrate with a defined processing region can be placed, and a mask moving unit that moves a mask stage on which one or a plurality of masks having a scanning width of the line-shaped light and on which a plurality of divided mask patterns obtained by dividing the mask pattern of the processing region are formed with respect to a plurality of strip-shaped scanning regions spaced apart from each other, and the line-shaped light can be sequentially scanned in the plurality of strip-shaped scanning regions.

[0027] Various configurations are possible for moving a linear beam of light from a strip-shaped scanning region of a divided mask pattern that has finished scanning to the next strip-shaped scanning region to be scanned. For example, the mask moving unit can move the mask stage to sequentially align the scanning position of the linear beam with the scanning start position of the strip-shaped scanning region of the divided mask pattern. Alternatively, the processing stage moving unit and the scanning unit can synchronize the movement of the processing stage and the line beam forming optical system, respectively, to align the irradiation position of the linear beam with the scanning start position of the strip-shaped scanning region of each divided mask pattern. [Effects of the Invention]

[0028] According to the present invention, it is possible to provide a mask design and laser processing method that can appropriately form a pattern on a substrate or the like while repeatedly scanning a line-shaped light during ablation processing. [Brief explanation of the drawing]

[0029] [Figure 1] This is a schematic diagram of the laser processing apparatus according to the first embodiment. [Figure 2] This is a schematic block diagram of a laser processing device. [Figure 3] This figure shows a mask for ablation processing in the first embodiment. [Figure 4] This figure shows a single mask pattern corresponding to the entire processing area AR of the substrate W. [Figure 5] This figure shows a mask for ablation processing in a laser processing apparatus, which is a second embodiment. [Modes for carrying out the invention]

[0030] Embodiments of the present invention will be described below with reference to the drawings.

[0031] Figure 1 is a schematic configuration diagram of a laser processing apparatus according to the first embodiment. Figure 2 is a schematic block diagram of the laser processing apparatus.

[0032] The laser processing apparatus 100 is a processing apparatus capable of forming a pattern on a substrate W by ablation processing, and comprises a line beam forming unit 20, a projection optical system 30, a mask stage 40, and a processing stage 50. The line beam forming unit 20, the mask stage 40, and the processing stage 50 are mounted on a main apparatus body (not shown) and are movable relative to the main apparatus body. The mask M and the substrate W are mounted on the mask stage 40 and the processing stage 50, respectively. In this case, the substrate W is made of a resin substrate such as a printed circuit board.

[0033] The laser 10, installed next to the main body of the device, emits high-energy-density laser light. Here, an excimer laser that pulses KrF excimer laser light with a wavelength of 248 nm is used. The laser light emitted from the laser 10 is guided to the line beam forming unit 20 via a corrective optical system for optical axis adjustment (not shown). The laser 10 may be configured as part of the laser processing apparatus 100, or as a separate device.

[0034] The line beam forming unit 20 includes an optical system such as a lens array 24, a line beam forming optical system 25 including a laser light cylindrical lens, and an angle switching mirror 26. The lens array 24 adjusts the intensity distribution of the incident laser light. The line beam forming optical system 25 shapes the beam of the incident laser light into a line-shaped light LB. For example, it is possible to shape the line-shaped light LB into a rectangular shape with a length of 26 mm and a width of 0.1 mm.

[0035] The line beam forming unit 20 houses optical systems such as the line beam forming optical system 25 in its casing 20K, and the casing 20K is supported by a scanning mechanism 60. The scanning mechanism 60 is capable of moving the line beam forming unit 20 at a predetermined speed along the main scanning direction (X direction), and is capable of moving the line-shaped light LB relative to the mask M in the main scanning direction (X direction), which is the scanning direction.

[0036] The angle-switching mirror 26 provided in the line beam forming section 20 can switch its angle (position) to shift the irradiation position of the line-shaped light LB on the mask M along the sub-scanning direction (Y direction), that is, to switch the scanning area. Here, the angle-switching mirror 26 is provided at a conjugate position between the lens array 24 and the line beam forming optical system 25.

[0037] The mask stage 40 supports the mask M and can be moved and rotated in the main scanning direction (X direction) and the sub-scanning direction (Y direction), which is the scanning width direction of the line-shaped light LB. The mask stage moving mechanism 70 drives the mask stage 40 based on a signal output from a position detection encoder (not shown).

[0038] The projection optical system 30 is an imaging optical system that focuses on the surface of the mask M and the surface of the substrate W, and projects light (pattern light) that has passed through the mask pattern formed on the mask M onto the substrate W. Here, the projection optical system 30 is configured as a reduction projection optical system and is set to a projection magnification of, for example, 0.5 times.

[0039] The processing stage 50 fixes the substrate W by vacuum suction or the like, and can move and rotate the substrate W in the main scanning direction (X direction) and the sub-scanning direction (Y direction). The processing stage movement mechanism 80 drives the processing stage 50 based on signals output from a position detection encoder (not shown). An alignment camera (not shown) is installed next to the processing stage 50 to capture alignment marks provided on the substrate W.

[0040] The substrate W, which is a resin substrate, has a copper wiring layer formed on a base material such as epoxy resin, and an insulating layer formed on top of that. By irradiating the substrate W with high-energy-density excimer laser light from the excimer laser 10, ablation occurs on the substrate W, and a pattern (hereinafter referred to as the processed pattern) WA is formed according to the mask pattern formed on the mask M. The processed pattern WA can be a through via, a non-through via, or a groove (trench) for a wiring pattern.

[0041] As the scanning mechanism 60 moves the line beam forming unit 20 in the main scanning direction (X direction), a line-shaped beam of light LB perpendicular to the main scanning direction (X direction) and parallel to the sub-scanning direction (Y direction) moves relative to the mask M (mask stage 40), the projection optical system 30, and the substrate W (processing stage 50). As a result, the mask M and substrate W mounted on the mask stage 40 and processing stage 50, respectively, are scanned. Here, a mask pattern corresponding to the pattern WA repeatedly formed on the substrate W is formed on the mask M.

[0042] The mask pattern formed on the mask M has an area size that exceeds the width of the line-shaped light LB, depending on the processing area AR where the processing pattern WA is formed and the projection magnification of the projection optical system 30. In this embodiment, the processing pattern WA is formed over the entire processing area AR by repeatedly scanning along the main scanning direction (X direction) while switching the irradiation position of the line-shaped light LB with the angle switching mirror 26.

[0043] As described later, the processing stage 50 moves in steps along the main scanning direction (X direction) and the sub-scanning direction (Y direction) each time a processing pattern WA is formed in the processing area, and ablation processing is performed over the entire substrate W. After the processing pattern is formed on the substrate W by ablation processing, a conductor such as copper is filled in. Alternatively, a mask pattern for drawing the pattern over the entire substrate W may be formed on the mask M.

[0044] The controller 90 controls the angle switching mirror 26, scanning mechanism 60, mask stage moving mechanism 70, and processing stage moving mechanism 80 of the line beam forming unit 20, and performs control during the ablation processing, namely, positioning of the mask M, positioning of the substrate W, movement of the line-shaped light LB in the main scanning direction (X direction) and switching of the irradiation position along the sub-scanning direction (Y direction).

[0045] In this embodiment, overlap scanning is performed along the main scanning direction (X direction) and the sub-scanning direction (Y direction) for scanning the linear light LB. On the other hand, the mask pattern is not configured as a single pattern corresponding to the processing area AR as a whole of the substrate W, but rather as multiple mask patterns formed at positions apart from each other. The combined pattern of these mask patterns is then configured as the pattern for the entire processing area AR. This will be described in detail below.

[0046] Figure 3 shows the mask pattern formed on the mask M for ablation processing. Figure 4 shows a single mask pattern corresponding to the entire processing area AR of the substrate W.

[0047] In the mask M, a light-shielding film (e.g., an Al film) is formed in areas other than the mask pattern, blocking the KrF excimer laser light from the substrate (e.g., quartz glass) that transmits the KrF excimer laser light. Here, a mask pattern (see black circle) is formed on the mask M to create through vias as a processing pattern.

[0048] As shown in Figure 3, the mask M has multiple (in this case, four) mask patterns (hereinafter referred to as divided mask patterns) P1 to P4, which are formed at positions that are separated from each other with respect to the main scanning direction (X direction) and the sub-scanning direction (Y direction). Each of the divided mask patterns P1 to P4 is contained within a rectangular strip-shaped scanning region.

[0049] Figure 4 shows a (virtual) mask pattern P0 configured as a single pattern to match a single processing area AR. When a single, integrated mask pattern P0 is configured, the shape and size of the pattern area MR containing the mask pattern P0 depend on the shape and size of the processing area AR and the reduction ratio of the projection optical system 30.

[0050] As described above, the line-shaped light LB formed by the line beamforming optical system 25 has a scanning width LW that requires multiple scans. This is based on reasons such as reducing the scanning width to obtain sufficient fluence to exceed the ablation threshold of the workpiece (in this case, the resin layer of the substrate W) and increasing the energy density per unit area.

[0051] The scanning width LW of the linear light LB is defined so that the linear light LB overlaps the scanning of the mask pattern P0. Rather than dividing the pattern region MR of the mask pattern P0 into multiple sections along the sub-scanning direction (Y direction) and defining the width of one of these sections as the scanning width LW, the scanning width LW is defined in such a way that an overlap region OL is provided. In this case, the linear light LB has a scanning width L that requires overlap scanning of the processing region AR in four separate steps.

[0052] The divided mask patterns P1 to P4 shown in Figure 3 are patterns formed by dividing the strip-shaped scanning regions M1 to M4, corresponding to the scanning width LW of the line-shaped optical fiber LB shown in Figure 4, so that they are spaced apart from each other along the main scanning direction (X direction) in accordance with the scanning order. Therefore, the divided mask patterns P1 to P4 (strip-shaped scanning regions MR1 ​​to MR4) are parallel to each other along the main scanning direction (X direction). The pattern regions MR1 ​​to MR4 corresponding to the scanning regions M1 to M4 each have a longitudinal length LL along the main scanning direction (X direction) of the mask pattern P0.

[0053] In accordance with the overlapping regions OL1, OL2, and OL3 provided in the strip-shaped scanning regions M1 to M4 shown in Figure 3, the strip-shaped scanning regions MR1 ​​to MR4 of the divided mask patterns P1 to P4 also have overlapping regions OG1, OG2, and OG3 along the sub-scanning direction (Y direction). Here, even if there is no overlapping portion as a region, regions OG1 to OG3 that overlap in position with respect to the sub-scanning direction (Y direction) are called overlapping regions.

[0054] The divided mask patterns P1 to P4 are formed by dividing and distributing the mask pattern P0 according to the strip-shaped scanning regions MR1 ​​to MR4. Therefore, some patterns formed near adjacent scanning regions are not formed in both scanning regions, but are distributed to one of them.

[0055] Thus, the divided mask patterns P1 to P4 are formed as discrete patterns in which the strip-shaped scanning regions M1 to M4, which are defined when overlap scanning is performed on the (virtual) mask pattern P0, which is configured as a single block of pattern in accordance with the processing region AR, are offset in the main scanning direction (X direction) before and after the scanning order.

[0056] Furthermore, the distance intervals along the main scanning direction (X direction) of the scanning areas of adjacent divided mask patterns are defined to be the same in this case. The offset distance interval D1 between divided mask pattern P1 and divided mask pattern P2 is equal to the offset distance interval D2 between divided mask pattern P3 and divided mask pattern P4. In other words, the four divided mask patterns P1 to P4 are separated from each other by a distance interval d with respect to the main scanning direction (X direction).

[0057] Ablation processing is performed on the mask M, which has discretely divided mask patterns P1 to P4 formed in this manner. During this process, overlap scanning is performed with intermittent movement of the mask M. In overlap scanning, a line-shaped light LB is scanned over the divided mask patterns P1 to P4 (band-shaped scanning regions MR11 to MR4) in this order.

[0058] As described above, scanning of the linear light LB along the main scanning direction (X direction) for each scanning region is performed by the movement of the line beam forming optical system 25 (line beam forming unit 20). Since the divided mask patterns P1 to P4 are not connected along the sub-scanning direction (Y direction) and are offset from each other, scanning of the irradiation regions of the linear light LB is not performed.

[0059] The shift in the irradiation position of the linear light LB along the sub-scanning direction (Y direction) is performed by the position control of the angle switching mirror 26, as described above. The amount of shift of the linear light LB at this time, i.e., the amount of mirror angle change, is determined considering the overlap region OG1 to OG3.

[0060] On the other hand, simply shifting the irradiation position of the linear light LB along the sub-scanning direction (Y direction) is insufficient because the divided mask patterns P1 to P4 are spaced apart from each other. Therefore, the position of the next scanning region must be aligned with the shifted position of the linear light LB. To achieve this, once scanning for one scanning region is complete, the mask M is moved by moving the mask stage 40, positioning the mask M at the scanning start position of the next scanning region.

[0061] Specifically, the mask M intermittently moves a distance D along the +X or -X direction each time it scans a divided mask pattern. For example, when scanning a divided mask pattern P1 (a strip-shaped scanning area MR1) causes the irradiation position of the line-shaped light LB to reach the end LP1 (see Figure 3), the angle switching mirror 26 shifts the irradiation position of the line-shaped light LB in the sub-scanning direction (Y direction) and moves the mask M a distance D along the -X direction.

[0062] As a result, the irradiation position of the line-shaped light LB moves to the scanning start position of the band-shaped scanning area MR2. Similarly, the mask M is moved for the movement of the line-shaped light LB from divided mask pattern P2 to divided mask pattern P3, and from divided mask pattern P3 to divided mask pattern P4. By intermittently moving the mask M through the movement of the mask stage 40 while the line-shaped light LB is folded and overlapped by the line beam forming unit 20, a processing pattern WA is formed in the processing area AR of the substrate W.

[0063] As described above, according to this embodiment, a mask M on which divided mask patterns P1 to P4 are formed is placed on a mask stage 40, and the linear light LB is scanned in the main scanning direction (X direction) and the irradiation position of the linear light LB is shifted in the sub-scanning direction (Y direction) by moving the line beam forming unit 20 and switching the angle of the angle switching mirror 26.

[0064] Then, by moving the mask stage 40, the mask M is moved, and the irradiation position of the line-shaped light LB is aligned with the scanning areas MR1 ​​to MR4. As a result, the processing areas are connected on the substrate W, and a processing pattern is formed in the processing area AR.

[0065] By performing this ablation process, it is possible to suppress the occurrence of insufficient processing (processing defects) due to beam irradiation with insufficient fluence, and to suppress the occurrence of differences in processing patterns in different processing areas.

[0066] In other words, the line-shaped light LB is blocked by the light-shielding film formed around the divided mask patterns P1 to P4. Therefore, the edges of the processing area AR on the substrate W are determined according to the positions of the strip-shaped scanning areas M1 to M4 on which the divided mask patterns P1 to P4 are formed.

[0067] Here, the formation positions of the divided mask patterns P1 to P4 correspond to the focal positions of the linear light LB. Therefore, the linear light LB can be blocked with high precision. In other words, a processing pattern can be formed with high precision in the overlapping portions OG1 to OG3 (corresponding to OL1 to OL3 in Figure 4) of the scanning regions MR1 ​​to MR4 of the processing region AR of the substrate W.

[0068] On the other hand, the divided mask patterns P1 to P4 are constructed by dividing the mask pattern P0 (Figure 4) according to the strip-shaped scanning regions MR1 ​​to MR4 and distributing the patterns to one of the scanning regions. Therefore, the line-shaped optical beams (LB) do not scan the same pattern repeatedly.

[0069] Furthermore, multiple divided mask patterns P1 to P4 are formed in a staggered pattern along the sub-scanning direction (Y direction) such that their distance intervals from each other are equal, and their distance intervals d are equal. With respect to the sub-scanning direction (Y direction), the divided mask patterns P1 to P4 are not offset. Therefore, the movement of the mask M is limited to the main scanning direction (X direction), and the pattern can be formed with high precision even at the machining seams of the machining area AR.

[0070] Next, a laser processing apparatus representing a second embodiment will be described using Figure 5. In the second embodiment, a divided mask pattern is formed on multiple masks.

[0071] Figure 5 shows a mask for ablation processing in the second embodiment. The divided mask patterns P1 to P4 are formed in two masks MA and MB. Specifically, the divided mask patterns formed in adjacent band-shaped regions along the sub-scanning direction (Y direction) are formed in different masks.

[0072] The shapes and sizes of masks MA and MB are equal in this case. The formation positions of the divided mask patterns P1 to P4 along the sub-scanning direction (Y direction) are defined to have the same overlapping regions OG1 to OG4 as in the first embodiment. Furthermore, the formation positions of the divided mask patterns P1 and P2 along the main scanning direction (X direction) are defined such that the distances A and A' from the reference position of masks MA and MB (here, the mask edge) to the divided mask patterns P1 and P2 are equal.

[0073] In the second embodiment, two such masks MA and MB are prepared, and ablation processing is performed while exchanging masks MA and MB. First, when mask MA is mounted on the mask stage 40, the strip-shaped scanning area MR1 of the divided mask pattern P1 is scanned. Then, by moving mask MA, the irradiation position of the line-shaped light LB is moved from the scanning end position LP1 to the scanning start position LP2 of the strip-shaped scanning area MR1 of the divided mask pattern P3.

[0074] Once scanning of the linear optical beam LB with the divided mask patterns P1 and P3 is complete, the mask MA is replaced with mask MB. Then, the linear optical beam LB is scanned with the strip-shaped scanning areas MR2 and MR4 of the divided mask patterns P1 and P3 on mask MB. The processing for each scanning area is connected, and the processing pattern WA is formed across the entire processing area AR. This represents scanning of the multiple scanning areas (divided processing areas) defined by dividing the processing area AR into several parts, sequentially scanning each mask together.

[0075] Thus, according to the second embodiment, the divided mask patterns P1 to P4 are formed not as a single mask as in the first embodiment, but as two separate masks MA and MB. This makes it possible to miniaturize the mask and reduce costs.

[0076] Furthermore, after scanning along all the strip-shaped scanning areas of the divided mask patterns formed on each mask, the mask is replaced and the same scanning is performed. This makes it possible to form a processing pattern on the processing area AR with a single mask change, thereby suppressing the decrease in processing throughput caused by using two masks.

[0077] Furthermore, the formation positions of the initially scanned segmented mask patterns P1 and P2 along the main scanning direction (X direction) in each mask are equal to the reference position in masks MA and MB. Therefore, scanning can be performed immediately after mask replacement without adjusting the mask position.

[0078] Regarding mask replacement, it may be performed by an operator or by an automated control system. In the case of automated mask replacement, multiple masks fixed to frames should be prepared and placed in a shelf-like storage area, and the system should be configured to sequentially retrieve the necessary masks using an automated transport mechanism, load them onto the mask stage 40, and then remove them.

[0079] A shutter mechanism may be provided above the mask stage 40, and the size of the irradiation area of ​​the mask M may be changed by adjusting the width (length in the Y direction) of the line-shaped light M. Furthermore, the scanning width (length along the sub-scanning direction (Y direction)) of the line-shaped light LB, the number of division patterns, the size of the overlap area, etc., can be determined according to the size and shape of the mask pattern P0 based on the processing area AR. In the second embodiment, the number of masks to be used may be determined according to the number of pattern divisions, etc.

[0080] In the first and second embodiments, the configuration is such that the line-shaped light LB is aligned with the band-shaped scanning area MR1 to MR4 by the intermittent movement of the mask. However, scanning alignment may also be performed in a similar manner by the synchronous movement of the line beam forming unit 20 and the processing stage 50 along the main scanning direction (X direction). In this case, the amount of movement of the line beam forming unit 20 and the processing stage 50 is determined according to the reduction magnification of the projection optical system 30.

[0081] Furthermore, overlap scanning of line-shaped light LB can be performed by moving only the mask stage 40, or by the cooperative movement of the mask stage 40 and the processing stage 50. In this case, since it is not necessary to move the line beam forming unit 20 along the main scanning direction (X direction) and shift the irradiation position along the sub-scanning direction (Y direction), even with a simple laser processing device, the same appropriate processing pattern can be formed by applying a mask as shown in the first and second embodiments. [Explanation of Symbols]

[0082] 10 lasers 20 Line beam forming section 25 Line beamforming optical system 26-angle adjustable mirror 30 Projection optical system 40 Mask Stage 50 Processing Stages 100 Laser Processing Equipment M Mask W board

Claims

1. A line beam forming optical system shapes the light emitted from the laser into a line, and guides the line-shaped light to a mask for ablation processing. An ablation process method for ablation processing a processing area of ​​a substrate by overlapping and scanning the aforementioned line-shaped light, For a single mask, a plurality of strip-shaped scanning regions are defined so as to be spaced apart in the scanning direction, each having a sub-scanning direction length corresponding to the scanning width of the line-shaped light and a scanning direction length longer than the scanning direction length of the line-shaped light. A plurality of divided mask patterns are formed in the plurality of strip-shaped scanning regions defined in the single mask, by dividing the mask pattern of the processing region according to the plurality of strip-shaped scanning regions. An ablation processing method characterized by overlapping scanning of the line-shaped light in the plurality of strip-shaped scanning regions.

2. By moving the line beam forming optical system in the scanning direction, the line-shaped light is scanned in the scanning direction with respect to the mask placed on the mask stage, The ablation processing method according to claim 1, characterized in that the irradiation position of the line-shaped light is aligned with the scanning start position of the strip-shaped scanning region of the divided mask pattern by moving the mask stage or by synchronously moving the processing stage on which the substrate is placed and the line beam forming optical system.

3. The ablation processing method according to Claim 1, characterized in that the line-shaped light is scanned in overlapping order according to the order in which the plurality of divided mask patterns are arranged along the scanning width direction.

4. A single ablation mask having a plurality of divided mask patterns formed by dividing the mask pattern of the processing area of ​​a substrate according to a plurality of strip-shaped scanning regions, each having a sub-scanning direction length corresponding to the scanning width of a line-shaped light formed by a line beam forming optical system of a laser processing apparatus, and a scanning direction length longer than the scanning length of the line-shaped light. The plurality of divided mask patterns are separated from each other along the scanning direction, The ablation mask is characterized in that the plurality of strip-shaped scanning regions are provided with overlapping regions that overlap positionally with respect to the sub-scanning direction.

5. The ablation mask according to claim 4, characterized in that the plurality of divided mask patterns are formed in a staggered pattern.

6. A line beam forming optical system for shaping light emitted from a laser into a line, A scanning unit that moves the line beam forming optical system to scan a line of light in the scanning direction, A processing stage moving unit that moves a processing stage on which a substrate with a defined processing area can be placed, It comprises a mask moving unit that moves a mask stage on which a single mask can be placed, The single mask has a sub-scanning direction length corresponding to the scanning width of the line-shaped light and a scanning direction length longer than the scanning direction length of the line-shaped light, which are spaced apart from each other in the scanning direction, and a plurality of divided mask patterns are formed in the plurality of strip-shaped scanning regions by dividing the mask pattern of the processing region according to the plurality of strip-shaped scanning regions. The scanning unit moves the line beam forming optical system in the scanning direction, thereby scanning the line-shaped light with respect to the single mask in the scanning direction. The mask moving unit moves the mask stage to align the irradiation position of the line-shaped light with the scanning start position of the band-shaped scanning region of the divided mask pattern. A laser processing apparatus characterized in that it is possible to perform overlap scanning of the line-shaped light in the plurality of strip-shaped scanning regions.

Images