Ablation processing method, ablation processing apparatus, substrate, and method for manufacturing substrate

Abstract

The present invention is an ablation processing method in which a recess is formed in a surface of a substrate by ablation processing using irradiation energy of a laser beam, an irradiation region of the laser beam in a single emission in the substrate is made smaller than a region to be processed of the substrate, and the substrate is irradiated by multiple emissions of the laser beam. In the irradiation of the plurality of radiations, the irradiation region of the laser beam is moved relative to the substrate in a first direction of the substrate and in a second direction orthogonal to the first direction, and the laser beam is irradiated on the whole surface of the region to be processed of the substrate while the irradiation region of the laser beam is moved relative to the substrate in the first direction and in the second direction orthogonal to the first direction. On the other hand, a part of the irradiation area in each sub-emission is overlapped with the irradiation area in the other emission in the first direction and the second direction in a manner that a concave part with a depth in a specified range is formed in the processing area of the substrate. Consequently, a recess having a target depth can be obtained, while preventing penetration of the film due to excessive processing, with a simple procedure.

Description

Technical Field

[0001] The present invention relates to an ablation processing method, an ablation processing apparatus, a substrate, and a method for manufacturing the substrate. Background Art

[0002] Semiconductor packaging substrates are shifting from the trend of "More Than Moore" to the trend of System on a Chip (SoC) that monolithizes the system, and are being actively developed along with this trend.

[0003] In addition, as the structure of semiconductor packaging substrates becomes more complex and denser, apparatuses using excimer lasers are gradually applied in the manufacture of their base substrates.

[0004] For example, Patent Document 1 describes a laser processing method in which a laser beam is used to perform shape processing on a workpiece until a specified depth position. The laser processing method is characterized in that the laser power of the laser beam and the relative movement speed between the workpiece and the laser beam are increased, and the number of irradiations required for laser processing is reduced so that the energy per unit length of the laser beam optimally set according to the workpiece is within the energy range that does not penetrate the workpiece even when the laser power increases due to power fluctuations in the laser oscillator.

[0005] In addition, Patent Document 2 describes a laser processing method in which, for an excavation region of a workpiece, a laser beam having a small beam profile with respect to the excavation region is sequentially irradiated to process the excavation region. The laser processing method is characterized by including: a first processing step of sequentially irradiating the entire excavation region with a laser beam having a first-shaped beam profile and forming a first irradiation region corresponding to the first-shaped beam profile on the workpiece; and a second processing step of sequentially irradiating the excavation region with a laser beam having a second-shaped beam profile smaller than the first shape and forming a second irradiation region corresponding to the second-shaped beam profile on the workpiece. In the first processing step, the laser beam forming the first irradiation region is sequentially irradiated in such a way that a part of the first irradiation regions overlap each other to form an overlapping region, and in the second processing step, the laser beam forming the second irradiation region is sequentially irradiated in such a way that the second irradiation region is included in a region other than the overlapping region in the excavation region.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Laid-Open No. 2009-22978

[0009] Patent Document 2: Specification of International Publication No. WO2013 / 094025 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] For example, in Patent Documents 1 and 2 described above, a laser processing method including overlapping irradiation regions of laser beams is proposed. In these methods, it is necessary to accurately align the ends of the irradiation regions of the laser beams. However, if the alignment is not performed at the micron level, for example, as Figure 17 shown, overprocessing occurs, forming a portion 88 with a very large local processing depth that can penetrate the substrate 80, or conversely, for example, as Figure 18 shown, a portion 89 that cannot be locally processed is generated in the substrate 80. As a result, in the existing methods, there are risks of film penetration or problems of not being able to obtain the target pattern locally.

[0012] In addition, a substrate with high reliability is also required.

[0013] The present invention is made to solve the above problems, and an object thereof is to provide an ablation processing method capable of obtaining a recess with a target depth while reducing the risk of film penetration by an easy procedure, an ablation processing apparatus capable of obtaining a recess with a target depth while reducing the risk of film penetration by an easy procedure, a substrate with high reliability that can be expected, and a manufacturing method capable of manufacturing a substrate with high reliability that can be expected.

[0014] Technical Means for Solving the Problems

[0015] To solve the above problems, in the present invention, an ablation processing method is provided, in which a recess is formed on the surface of a substrate by ablation processing using the irradiation energy of a laser beam. In the ablation processing method,

[0016] the irradiation region of the laser beam in a single emission in the substrate is made smaller than the region to be processed of the substrate, and the substrate is irradiated with the laser beam in multiple emissions, whereby the entire surface of the region to be processed of the substrate is irradiated with the laser beam,

[0017] in the multiple emissions irradiation, while relatively moving the irradiation region of the laser beam with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, a recess having a depth within a specified range is formed in the region to be processed of the substrate, and a part of the irradiation region in each emission overlaps the irradiation region in other emissions in the first direction and the second direction.

[0018] By means of the ablation processing method of the present invention, in such a manner that a recess having a depth within a specified range is formed in the processing region of the substrate, a part of the irradiation region in each emission overlaps with the irradiation regions in other emissions in the first direction and the second direction. Thus, a recess with a target depth can be obtained with a simple procedure while preventing film penetration due to overprocessing.

[0019] In the irradiation of the multiple emissions, it may be that

[0020] a light source and a mask are used, the light source oscillates the laser beam, and the mask includes an effective region having a pattern corresponding to the recess to be formed in the substrate.

[0021] The laser beam from the light source is irradiated onto a mask irradiation region that is a part of the effective region of the mask.

[0022] The laser beam that has passed through the mask is irradiated onto a substrate irradiation region that is at least a part of the processing region of the substrate, and the pattern is projected onto the substrate irradiation region to perform ablation processing.

[0023] When the irradiation region of the laser beam is relatively moved with respect to the substrate, the mask and the substrate are synchronously shifted in a plane direction substantially perpendicular to the irradiation direction of the laser beam.

[0024] In the present invention, for example, ablation processing can be performed using a mask in such a manner. In addition, in the above configuration, the processing region is not limited by the region of the lens, so that an area (field angle) larger than the region of the lens can be processed.

[0025] In addition, through the above configuration, the reduction projection optical system required during irradiation can be reduced, and the laser irradiation position accuracy or temperature controllability can also be good. Furthermore, since the reduction projection optical system can be made smaller, the distortion of the image caused by irradiation is also less.

[0026] In the above case, it is preferable to irradiate the mask irradiation region of the mask with the laser beam having a rectangular irradiation shape.

[0027] By irradiating the laser beam having a rectangular irradiation shape, film penetration due to overprocessing can be more reliably prevented.

[0028] In particular, by performing rectangular irradiation, for example, compared with the overlapping irradiation of circular irradiation, the efficiency can be better, and the position or number of microscopic overlapping irradiations can be controlled more accurately.

[0029] In addition, it is preferable to perform laser beam irradiation without stopping the mask and the substrate during the irradiation of the multiple emissions in the first direction and / or the second direction.

[0030] As described above, ablation processing can be performed more efficiently.

[0031] In addition, when the first mask and the second mask are used as the mask, it can be

[0032] Irradiate the multiple emissions using the first mask.

[0033] Next, replace the first mask with the second mask.

[0034] Irradiate the multiple emissions using the second mask in such a manner that a part of the substrate irradiation area of the substrate overlaps with a part of the substrate irradiation area generated by the irradiation of the multiple emissions using the first mask in the first direction.

[0035] In the present invention, not only one mask can be used, but also two or more masks can be used. By using two or more masks, a larger area of the processing area of the substrate can be processed efficiently.

[0036] For example, an excimer laser can be used as the laser beam.

[0037] In the ablation processing method of the present invention, for example, an excimer laser can be used. By using an excimer laser, it is possible to efficiently ablate the processing surface of a substrate containing an organic material such as an Ajinomoto Build-up Film (ABF) substrate, achieving highly productive processing. In addition, since the interferability of the excimer laser is low, by using the excimer laser, the position or number of micro-overlapping irradiations can be controlled more accurately.

[0038] For example, ablation processing can be performed on a semiconductor package substrate as the substrate.

[0039] The substrate to be processed is not particularly limited. For example, a semiconductor package substrate can be used as the processing object.

[0040] Especially in the case of processing a semiconductor package substrate, there are processing patterns such as the coexistence of VIA processing or groove processing. In such a case, the processing can be performed in the same process by the method of the present invention without dividing it into the processes of VIA processing and groove processing.

[0041] In addition, the semiconductor package substrate is being advanced in high density. In the laser drilling method in the through-hole processing performed hitherto, since the processing time increases due to the increase in the number of hole processes accompanying the high density, in this method, there is no increase in the processing time caused by the increase in the number of hole processes or the high refinement of the pattern.

[0042] In addition, the present invention provides an ablation processing apparatus that forms a recess on the surface of a substrate by ablation processing using the irradiation energy of a laser beam.

[0043] The ablation processing apparatus includes:

[0044] A light source that oscillates the laser beam;

[0045] A substrate stage that supports the substrate; and

[0046] A controller,

[0047] The controller is configured to perform the following control:

[0048] Make the irradiation area of the laser beam in one emission of the substrate smaller than the processing area of the substrate, and irradiate the substrate with multiple emissions of the laser beam, thereby irradiating the entire surface of the processing area of the substrate with the laser beam.

[0049] During the irradiation of the multiple emissions, while moving the irradiation area of the laser beam relative to the substrate in the first direction of the substrate and the second direction orthogonal to the first direction respectively, and forming a recess having a depth within a specified range in the processing area of the substrate, a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction.

[0050] If such an ablation processing apparatus of the present invention is used, a recess having a depth within a specified range can be formed in the processing area of the substrate, and a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction. As a result, a recess with a target depth can be obtained while preventing film penetration caused by overprocessing with a simple program.

[0051] Preferably, it further includes:

[0052] A mask including an effective area having a pattern corresponding to the processing area of the substrate; and

[0053] A mask stage that supports the mask,

[0054] The controller is further configured to: further, move the mask stage and the substrate stage synchronously in a plane direction substantially perpendicular to the irradiation direction of the laser beam.

[0055] In the ablation processing apparatus of the present invention, a mask can be used in such a manner, for example. In addition, in the above-described form, the processing area is not restricted by the area of the lens, and thus, an area (field angle) larger than the area of the lens can be processed.

[0056] In addition, by the above-described form, the reduction projection optical system required during irradiation can be reduced, and the laser irradiation position accuracy or temperature controllability can also be good. Furthermore, since the reduction projection optical system can be made smaller, the distortion of the image caused by irradiation is also small.

[0057] In the above case, it is preferable that a shaping optical system is further included between the light source and the mask, and the shaping optical system shapes the irradiation shape of the laser beam into a rectangular irradiation shape.

[0058] If it is the ablation processing apparatus of the above-described preferable form, a laser beam having a rectangular irradiation shape can be irradiated, and as a result, film penetration due to overprocessing can be more reliably prevented.

[0059] In particular, by performing rectangular irradiation, for example, compared with the overlapping irradiation of circular irradiation, the efficiency can be better, and the position or number of microscopic overlapping irradiations can be controlled more accurately.

[0060] The light source can be a excimer laser light source.

[0061] The light source is not particularly limited, and for example, an excimer laser light source can be used. By using an excimer laser, the processing surface of a substrate containing an organic material such as an ABF substrate can be efficiently ablated, and high-productivity processing can be achieved. In addition, since the interferability of the excimer laser is low, by using an excimer laser, the position or number of microscopic overlapping irradiations can be controlled more accurately.

[0062] In addition, the present invention provides a substrate having grooves on its surface. In the substrate,

[0063] The bottom of the groove has a plurality of recesses periodically arranged in the length direction of the groove.

[0064] Such a substrate can exhibit an anchoring effect, that is, a plurality of recesses periodically arranged in the length direction of the groove fix a layer or the like formed thereon, and thus, high reliability can be exhibited. If it is such a substrate, peeling of the buried conductive layer that may occur in a plating process or chemical mechanical polishing (CMP) or the like performed after the ablation processing step of the present invention is less likely to occur, and in the finally processed product, a high-quality product having high resistance to stress caused by thermal cycling or the like can also be provided.

[0065] The substrate can be, for example, a semiconductor package substrate.

[0066] The type of the substrate is not particularly limited. For example, it can be a semiconductor package substrate.

[0067] Especially in the case of processing a semiconductor package substrate, there are processing patterns such as via hole processing or groove processing existing in combination. In such a case, the processing can be carried out in the same process by the method of the present invention without dividing the processes of via hole processing and groove processing.

[0068] In addition, the semiconductor package substrate is being advanced towards high density. In the laser drilling method in the via hole processing carried out hitherto, since the processing time becomes longer due to the increase in the number of hole processes accompanying high density, in contrast, in this method, there is no increase in the processing time caused by an increase in the number of hole processes or high refinement of the pattern.

[0069] In addition, the present invention provides a method for manufacturing a substrate, which manufactures a substrate having grooves on the surface by ablation processing using the irradiation energy of a laser beam, wherein,

[0070] the irradiation area of the laser beam in a single emission in the substrate is made smaller than the area to be processed of the substrate, and the substrate is irradiated with the laser beam in multiple emissions, thereby irradiating the entire surface of the area to be processed of the substrate with the laser beam,

[0071] in the irradiation in the multiple emissions, while the irradiation area of the laser beam is relatively moved with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction respectively, in such a manner that a groove having a depth within a specified range is formed in the area to be processed of the substrate, a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction,

[0072] the irradiation in the multiple emissions is carried out in such a manner that irradiation areas with different overlapping times are respectively provided in the first direction and the second direction,

[0073] thereby manufacturing a substrate in which a plurality of recesses are periodically arranged in the length direction of the bottom of the groove.

[0074] By the method for manufacturing a substrate of the present invention, a substrate in which a plurality of recesses are periodically arranged in the length direction of the bottom of the groove can be manufactured. Such a substrate can exhibit an anchoring effect, that is, the plurality of recesses periodically arranged in the length direction of the groove fix a layer or the like formed thereon, thereby exhibiting high reliability.

[0075] If it is such a manufacturing method, it is not likely to cause the peeling of the buried conductive layer that may occur in the plating process or CMP etc. carried out after the manufacturing method of the present invention. In the finally processed product, it is also possible to provide a high-quality product with high resistance to stress caused by thermal cycling etc.

[0076] Effects of the Invention

[0077] As described above, if it is the ablation processing method of the present invention, a concave portion with a target depth can be obtained while preventing film penetration caused by overprocessing with a simple procedure.

[0078] In addition, if it is the ablation processing device of the present invention, it becomes a device that can obtain a concave portion with a target depth while preventing film penetration caused by overprocessing with a simple procedure.

[0079] In addition, regarding the substrate of the present invention, it is expected to provide a highly reliable packaging substrate.

[0080] Moreover, by the manufacturing method of the substrate of the present invention, a substrate with high reliability can be manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 is a schematic diagram showing an example of the ablation processing device of the present invention.

[0082] Figure 2 is a schematic diagram showing an example of the laser beam irradiation area of a single emission in the ablation processing method of the present invention.

[0083] Figure 3 is a schematic diagram showing an example of the overlapping irradiation in the ablation processing method of the present invention.

[0084] Figure 4 is a schematic diagram showing an example of the overlapping irradiation in the ablation processing method of the present invention.

[0085] Figure 5 is a schematic diagram showing an example of the overlapping irradiation in the ablation processing method of the present invention.

[0086] Figure 6 is Figure 5 a schematic plan view of a part of the substrate after the overlapping irradiation shown.

[0087] Figure 7 is a schematic diagram showing an example of the overlapping irradiation in the ablation processing method of the present invention.

[0088] Figure 8 is a schematic diagram showing an example of the overlapping irradiation in the ablation processing method of the present invention.

[0089] ​​​​​​​​​Figure 9 is a flowchart of an example of the ablation processing method of the present invention.

[0090] Figure 10 is a schematic diagram showing Figure 9 an example of ablation processing in the example shown.

[0091] Figure 11 is a schematic diagram showing an example of overlapping irradiation for forming a recess at the bottom of a groove.

[0092] Figure 12 is a schematic diagram showing an example of overlapping irradiation for suppressing the formation of a recess at the bottom of a groove.

[0093] Figure 13 is a schematic diagram showing another example of overlapping irradiation for suppressing the formation of a recess at the bottom of a groove.

[0094] Figure 14 is a schematic diagram showing an example of ideal irradiation for preventing the formation of a recess at the bottom of a groove portion.

[0095] Figure 15 is a schematic diagram of overlapping irradiation of a reference example.

[0096] Figure 16 is a schematic diagram showing an example of overlapping irradiation for suppressing the formation of a recess at the bottom of a groove.

[0097] Figure 17 is a schematic diagram showing ablation processing as an example of the prior art.

[0098] Figure 18 is a schematic diagram showing ablation processing as an example of the prior art. DETAILED DESCRIPTION

[0099] As described above, there is a demand for developing an ablation processing method that can obtain a recess with a target depth while reducing the risk of film penetration with an easy procedure, an ablation processing apparatus that can obtain a recess with a target depth while reducing the risk of film penetration with an easy procedure, a substrate with high reliability to be expected, and a manufacturing method capable of manufacturing a substrate with high reliability to be expected.

[0100] The inventors of the present invention repeatedly made diligent studies on the above problems, and as a result, found that by forming a recess with a depth within a specified range in a processing region of a substrate, and overlapping a part of the irradiation region in each emission in a first direction and a second direction with the irradiation region in other emissions, it is possible to obtain a recess with a target depth while preventing film penetration due to overprocessing with a simple procedure, thereby completing the present invention.

[0101] ​​​​​​​​​In addition, the inventors et al. found that if a substrate having a plurality of recesses periodically arranged in the length direction of the groove is used, an anchoring effect of fixing a layer or the like formed on the plurality of recesses can be exhibited, and high reliability of a semiconductor package substrate can be expected, thus completing the present invention.

[0102] That is, the present invention is an ablation processing method in which a recess is formed on the surface of a substrate by ablation processing using irradiation energy of a laser beam. In the ablation processing method,

[0103] the irradiation area of the laser beam in a single emission in the substrate is made smaller than the processing area of the substrate, and the substrate is irradiated with the laser beam multiple times, whereby the entire surface of the processing area of the substrate is irradiated with the laser beam.

[0104] In the multiple emissions of irradiation, while the irradiation area of the laser beam is relatively moved with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction in such a manner that the recess having a depth within a specified range is formed in the processing area of the substrate.

[0105] In addition, the present invention is an ablation processing apparatus in which a recess is formed on the surface of a substrate by ablation processing using irradiation energy of a laser beam.

[0106] The ablation processing apparatus includes:

[0107] a light source that oscillates the laser beam;

[0108] a substrate stage that supports the substrate; and

[0109] a controller,

[0110] The controller is configured to perform the following control:

[0111] The irradiation area of the laser beam in a single emission in the substrate is made smaller than the processing area of the substrate, and the substrate is irradiated with the laser beam multiple times, whereby the entire surface of the processing area of the substrate is irradiated with the laser beam.

[0112] In the irradiation of the multiple emissions, while relatively moving the irradiation region of the laser beam with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, respectively, a part of the irradiation region in each emission overlaps with the irradiation regions in other emissions in the first direction and the second direction in such a manner that a recess having a depth within a specified range is formed in the processed region of the substrate.

[0113] In addition, the present invention relates to a substrate having grooves on its surface. In this substrate,

[0114] the bottom of the groove has a plurality of recesses periodically arranged in the length direction of the groove.

[0115] In addition, the present invention relates to a method for manufacturing a substrate. A substrate having grooves on its surface is manufactured by ablation processing using the irradiation energy of a laser beam. In this method,

[0116] the irradiation region of the laser beam in one emission in the substrate is made smaller than the processed region of the substrate, and the substrate is irradiated with the laser beam multiple times, thereby irradiating the entire surface of the processed region of the substrate with the laser beam.

[0117] In the irradiation of the multiple emissions, while relatively moving the irradiation region of the laser beam with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, respectively, a groove having a depth within a specified range is formed in the processed region of the substrate in such a manner that a part of the irradiation region in each emission overlaps with the irradiation regions in other emissions in the first direction and the second direction.

[0118] The irradiation of the multiple emissions is performed in such a manner that irradiation regions having different overlapping frequencies are provided in the first direction and the second direction, respectively.

[0119] Thereby, a substrate is manufactured in which the bottom of the groove has a plurality of recesses periodically arranged in the length direction of the groove.

[0120] Hereinafter, the present invention will be described in detail, but the present invention is not limited to these.

[0121] [Ablation Processing Apparatus]

[0122] Figure 1 is a schematic diagram showing an example of the ablation processing apparatus of the present invention. Figure 1 The shown ablation processing apparatus 100 is an ablation processing apparatus that forms a recess on the surface of a substrate 80 by ablation processing using the irradiation energy of a laser beam 4. In addition, Figure 1The ablation processing apparatus 100 shown is an example of the ablation processing apparatus of the present invention, but the ablation processing apparatus of the present invention is not limited to Figure 1 the apparatus shown.

[0123] Figure 1 The ablation processing apparatus 100 shown includes: a light source 11 that oscillates a laser beam; a substrate stage 40 that supports a substrate 80; and a controller 90.

[0124] More specifically, Figure 1 the ablation processing apparatus 100 of the example shown includes a first optical functional unit 10 and a second optical functional unit 20.

[0125] The light source 11 that oscillates the laser beam is a light source (laser oscillator) 11 that irradiates (emits) the laser beam 1 in a pulsed manner, and is included in the first optical functional unit 10. As the laser beam 1, for example, an excimer laser can be used, but there is no particular limitation.

[0126] The first optical functional unit 10 further includes an arbitrary shaping optical system 12 irradiated with the laser beam 1 from the light source 11. The shaping optical system 12 shapes the irradiation shape shown in, for example, Figure 1 (a) into, for example, Figure 1 the rectangular irradiation shape shown in (b). The laser beam 2 having a rectangular irradiation shape can exhibit a uniform irradiation energy density, and for example, has a top-hat shaped beam profile.

[0127] The arbitrary second optical functional unit 20 includes a mask 21. The mask 21 includes an effective region 22 having a pattern corresponding to the recess to be formed in the substrate 80. The size of the mask 21 is not particularly limited. For example, a mask 21 having an outer shape of 700 mm × 800 mm and an effective region 22 size of 600 mm × 600 mm can be used.

[0128] The mask 21 includes a mask irradiation region irradiated with the laser beam 2 that has passed through the first optical functional unit 10. The mask irradiation region is a part of the effective region 22 of the mask 21.

[0129] The laser beam 3 that has passed through the second optical functional unit 20 and has, for example, Figure 1 the irradiation shape shown in (c) passes through an arbitrary folding mirror 50, changes its traveling direction as shown in Figure 1 (d), and is incident on an arbitrary third optical functional unit 30 (to be described later). Figure 1 The ablation processing apparatus 100 of the example shown is configured such that the laser beam 4 emitted from the third optical functional unit 30 is irradiated onto a part of the substrate 80 held by the substrate stage 40.

[0130] The substrate 80 includes a substrate irradiation area on which a pattern is projected by a laser beam passing through the mask 21 (and any optional third optical functional unit 30).

[0131] In Figure 1 the example of, the mask 21 is configured to scan (sweep) along the Figure 1 shown sweep axis 21X and sweep axis 21Y. In addition, the substrate stage 40 is configured to scan along the Figure 1 shown sweep axis 80X and sweep axis 80Y.

[0132] The controller 90 is configured to control in such a manner that the irradiation area of the laser beam 4 in one emission in the substrate 80 is smaller than the processing area of the substrate 80, and the substrate 80 is irradiated with the laser beam 4 in multiple emissions, whereby the entire surface of the processing area of the substrate 80 is irradiated with the laser beam. In the multiple emissions irradiation, while causing the irradiation area of the laser beam 4 to relatively move with respect to the substrate 80 in the first direction (for example, the direction of the sweep axis 80X) and the second direction (for example, the direction of the sweep axis 80Y) orthogonal to the first direction of the substrate 80, respectively, a concave portion having a depth within a specified range is formed in the processing area of the substrate 80, and a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction. Details of such control will be described below.

[0133] [Ablation processing method]

[0134] The ablation processing method of the present invention can be performed, for example, using the ablation processing apparatus of the present invention, but can also be performed using an apparatus other than the ablation processing apparatus of the present invention.

[0135] Hereinafter, an example of the ablation processing method of the present invention that can be performed using the Figure 1 shown ablation processing apparatus 100 will be specifically described.

[0136] The ablation processing method of the present invention is an ablation processing method for forming a concave portion on the surface of the substrate 80 by ablation processing using the irradiation energy of the laser beam 4.

[0137] In the ablation processing method of the present invention, for example, as Figure 2 schematically shown in, the irradiation area 41 of the laser beam 4 in one emission in the substrate 80 is smaller than the processing area 8 of the substrate 80.

[0138] Moreover, the substrate 80 is irradiated with the laser beam 4 in multiple emissions, whereby the entire surface of the processing area 8 of the substrate 80 is irradiated with the laser beam.

[0139] At this time, in the ablation processing method of the present invention, during multiple emissions of irradiation, while moving the irradiation region 41 of the laser beam 4 relative to the substrate 80 in the first direction (e.g., Figure 1 the direction of the scanning axis 80X of Figure 1 the substrate 80) and the second direction orthogonal to the first direction 80X (e.g.,

[0140] the direction of the scanning axis 80Y of Figure 7 the substrate 80), while forming a concave portion having a depth within a specified range in the processing region 8 of the substrate 80, a part of the irradiation region 41 in each emission is overlapped with the irradiation region 41 in other emissions in the first direction 80X and the second direction 80Y. The following describes specific examples of the overlapping irradiation (hereinafter, also referred to as stitching) in the present invention. In addition, regarding the depth within the specified range, reference will be made to Figure 7 and Figure 8 which will be described in the latter part.

[0141] In Figure 3 the example of overlapping irradiation shown, while moving the irradiation regions 41A-1, 41B-1, 41C-1, and 41D-1 relative to the substrate 80 in the first direction 80X, a part of the irradiation region 41A-1 is overlapped with the irradiation regions 41B-1 and 41C-1 in the first direction 80X, a part of the irradiation region 41B-1 is overlapped with the irradiation regions 41A-1, 41C-1, and 41D-1 in the first direction 80X, a part of the irradiation region 41C-1 is overlapped with the irradiation regions 41A-1, 41B-1, and 41D-1 in the first direction 80X, and a part of the irradiation region 41D-1 is overlapped with the irradiation regions 41B-1 and 41C-1 in the first direction 80X.

[0142] Such overlapping irradiation is repeated until the emission of the laser beam irradiation of the irradiation region 41Z-1 shown in Figure 4 is performed. Then, the irradiation region 41 of the laser beam 4 is moved relative to the substrate 80 in the first direction 80X and the second direction 80Y orthogonal to the first direction 80X. Specifically, the irradiation region 41 is moved so as to become the irradiation region 41A-2 that overlaps with the previous irradiation regions 41A-1, 41B-1, and 41C-1 in the second direction 80Y. Then, while moving the irradiation region 41 relative to the substrate 80 in the first direction 80X, the same overlapping irradiation as before is performed.

[0143] A schematic diagram of performing overlapping irradiation while moving the irradiation region 41 in the first direction 80X and the second direction 80Y as described above is shown inFigure 5 In Figure 5 (a), from the irradiation regions 41A-1 and 41B-1 to the irradiation regions 41Y-1 and 41Z-1, overlapping irradiation is performed while relatively moving the irradiation region 41 in the first direction 80X. Subsequently, in Figure 5 (b), the irradiation region 41 of the laser beam 4 is relatively moved with respect to the substrate 80 in the first direction 80X and the second direction 80Y orthogonal to the first direction 80X. Subsequently, while relatively moving the irradiation region 41 with respect to the substrate 80 in the first direction 80X, the laser beam irradiation from the irradiation region 41A-2 to the irradiation region 41Z-2 is performed in such a manner that it overlaps with the irradiation regions 41A-1 to 41Z-1 in the second direction 80Y and also overlaps in the first direction 80X in the same manner as before. Subsequently, in Figure 5 (c), the irradiation region 41 of the laser beam 4 is relatively moved with respect to the substrate 80 in the first direction 80X and the second direction 80Y orthogonal to the first direction 80X. Subsequently, while relatively moving the irradiation region 41 with respect to the substrate 80 in the first direction 80X, the laser beam irradiation from the irradiation region 41A-3 to the irradiation region 41Z-3 is performed in such a manner that it overlaps with Figure 5 the irradiation regions 41A-1 to 41Z-1 irradiated in the process of Figure 5 (a) and

[0144] Figure 6 represents Figure 5 a schematic plan view of a part of the substrate after the overlapping irradiation shown. In Figure 6 it is as Figure 5As a result of relatively moving the irradiation region 41 emitted at one time in the first direction 80X and the second direction 80Y with respect to the substrate 80 and overlapping a part of the irradiation region 41 in each emission in the first direction 80X and the second direction 80Y as shown. More specifically, in the overlap in the first direction 80X, one-fourth of the width of the irradiation region 41 in the first direction 80X in one emission is overlapped with the irradiation region 41 in the previous emission. In addition, in the overlap in the second direction 80Y, one-third of the width of the irradiation region 41 in the second direction 80Y in one emission is overlapped with other irradiation regions 41 located above and below in the second direction 80Y. In addition, the example of the overlap is only one example, and in the present invention, the degree of overlap is not particularly limited. In addition, the degree of overlap can also be changed according to the part.

[0145] In addition, in Figure 5 and Figure 6 in the example shown, the sweep in the first direction 80X is in the same direction (the direction from left to right in the drawing) in the first row, the second row, and the third row, but for example, the direction can also be changed between even rows and odd rows, or the sweep direction can be set to the vertical direction ( Figure 6 the second direction 80Y).

[0146] In Figure 6 , the irradiation regions 41I in the first emission, 41X in the tenth emission, 41XX in the twentieth emission, and 41XXX in the thirtieth emission are shown in sequence along the first direction 80X. In addition, the first row 41-1 to the eighth row 41-8 of a series of overlapping irradiations in the first direction 80X are shown in sequence along the second direction 80Y.

[0147] Moreover, in Figure 6 , the set of regions where the overlap is 4 times or more in the first direction 80X and 3 times or more in the second direction becomes the processing effective region 82 as the uniform irradiation portion. The processing effective region 82 corresponds to the concave portion to be processed.

[0148] In the ablation processing method of the present invention, the overlapping irradiation described in detail above is performed so as to form a concave portion having a depth within a specified range in the processing region 8 of the substrate 80.

[0149] In Figure 7 , a specific example is shown. In Figure 7 in the process shown, the upper part is a plan view of the irradiation shape 41 in each emission, and the lower part is a cross-sectional view of the substrate 80 after each emission. In Figure 7 in the upper part, the laser irradiation region in this emission is surrounded by a dotted frame line, and the traces of the previous laser irradiation are shown without a frame line.

[0150] In the first emission, as Figure 7 (a) shows, the laser beam 4 with the irradiation shape 41A is irradiated onto the substrate 80 to form the recess 83a.

[0151] In the second emission, as Figure 7 (b) shows, the laser beam 4 with the irradiation shape 41B is irradiated onto the substrate 80 to form the recess 83b. In the recess 83b, the portion 84b formed by the repetition of the first emission and the second emission has a depth greater than the depth of the recess 83a.

[0152] In the third emission, as Figure 7 (c) shows, the laser beam 4 with the irradiation shape 41C is irradiated onto the substrate 80 to form the recess 83c. In the recess 83c, the portion 84c formed by the repetition of the first emission, the second emission, and the third emission has a depth greater than the maximum depth of the recess 83b.

[0153] In the fourth emission, as Figure 7 (d) shows, the laser beam 4 with the irradiation shape 41D is irradiated onto the substrate 80 to form the recess 83d. In the recess 83d, the portion 84d formed by the repetition of the first emission, the second emission, the third emission, and the fourth emission has a maximum depth 85 greater than the maximum depth of the recess 83c.

[0154] In the fifth emission, as Figure 7 (e) shows, the laser beam 4 with the irradiation shape 41E is irradiated onto the substrate 80 to form the recess 83e. In the portion of the recess 83e adjacent to the portion 84d with the maximum depth formed in the fourth emission, it includes the portion 84e formed by the repeated irradiation of the second emission, the third emission, the fourth emission, and the fifth emission. Since the portion 84e is formed using the energy of the laser beam 4 corresponding to four emissions, the maximum depth of the portion 84e is the same as the maximum depth 85 of the portion 84d formed using the energy of the laser beam 4 corresponding to four emissions.

[0155] In the sixth emission, as Figure 7 (f) shows, the laser beam 4 with the irradiation shape 41F is irradiated onto the substrate 80 to form the recess 83f. In the portion of the recess 83f adjacent to the portion 84e with the maximum depth formed in the fifth emission, it includes the portion 84f formed by the repeated irradiation of the third emission, the fourth emission, the fifth emission, and the sixth emission. Since the portion 84f is formed using the energy of the laser beam 4 corresponding to four emissions, the maximum depth of the portion 84f is the same as the maximum depth 85 of the portion 84e formed using the energy of the laser beam 4 corresponding to four emissions.

[0156] By performing overlapping irradiation in the same manner even after the seventh emission, finally, as shown in Figure 7 (g), a recess 83z is formed. The portion 84z of the maximum depth of the recess 83z and the portion 84d of the maximum depth 85 of the recess 83d are formed using the energy of the laser beam 4 corresponding to four emissions. Therefore, the maximum depth of the portion 84z is the maximum depth 85.

[0157] Figure 7 The depth of the recess formed by performing overlapping irradiation while relatively moving the irradiation region 41 with respect to the substrate 80 in the first direction (for example, Figure 1 in the direction of the scanning axis 80X) has been described. In the ablation processing method of the present invention, as described with reference to Figure 5 and Figure 6 , overlapping irradiation is also performed while moving in the second direction orthogonal to the first direction (for example, Figure 1 in the direction of the scanning axis 80Y). As a result, the maximum depth of the obtained recess becomes within a specified range.

[0158] The so-called depth within the specified range in the present invention is within the depth range of the recess allowed to be formed on the substrate 80. When it is assumed that a recess with a depth of 15 μm is to be formed, the depth within the specified range can be set to 15 μm ± 3 μm, for example.

[0159] By the above, the ablation processing method of the present invention can obtain a recess with a target depth on the substrate 80 while preventing film penetration due to overprocessing with a simple procedure.

[0160] In addition, as a modification example, for example, as shown in Figure 8 , by changing the overlapping degree of emissions, portions with different maximum depths can be formed periodically. Specifically, in Figure 7 (e), the irradiation region 41E of the fifth emission is not overlapped with the irradiation region 41A of the first emission. However, as shown in Figure 8 (e), by overlapping a part of the irradiation region 41E of the fifth emission with the irradiation region 41A of the first emission, a portion 86 with a maximum depth 87 can be formed. Subsequently, as shown in Figure 8 (f), by overlapping a part of the irradiation region 41F of the sixth emission with the irradiation region 41B of the second emission to the same extent as the overlapping of the irradiation region 41E of the fifth emission and the irradiation region 41A of the first emission shown in Figure 8 (e), another portion 86 with the same maximum depth 87 as that formed during the fifth emission can be formed. Moreover, by periodically repeating the same overlapping, as shown in Figure 8As shown in (g), a plurality of recesses 86 periodically arranged in one direction 86A may be formed at the bottom of the recess 83z. Among them, it is important to perform overlapping irradiation in such a way that the maximum depth 87 of the plurality of portions 86 falls within the specified range.

[0161] The overlapping irradiation described above may also be performed without using, for example, Figure 1 the mask 21 shown. On the other hand, by using Figure 1 the mask 21 shown, ablation processing of various micro-shaped patterns can be performed.

[0162] In the case of using the mask 21, it is preferable that the laser beam 2 from the light source 11 is irradiated onto the mask irradiation region which is a part of the effective region 22 of the mask 21, the laser beam 4 that has passed through the mask 21 is irradiated onto the substrate irradiation region which is at least a part of the region to be processed 8 of the substrate 80, the pattern is projected onto the substrate irradiation region to perform ablation processing, and when the irradiation region 41 of the laser beam 4 moves relative to the substrate 80, the mask 21 and the substrate 80 are synchronously shifted in the plane direction substantially perpendicular to the irradiation direction of the laser beam 4.

[0163] In the above preferred form, the processing region is not limited by the region of the lens (for example, the third optical functional unit 3), so that an area (field angle) larger than the region of the lens can be processed.

[0164] In addition, through the above form, the reduction projection optical system 31 (described later) required during irradiation can be reduced, and the laser irradiation position accuracy or temperature controllability can also be good. Furthermore, since the reduction projection optical system 31 can be made smaller, the distortion of the image caused by irradiation is also small.

[0165] In addition, it is preferable that, for example, a laser beam 2 having a rectangular irradiation shape is irradiated onto the mask irradiation region of the mask 21 using an ablation processing apparatus 100 as shown in Figure 1 .

[0166] By the above, the laser beam 4 having a rectangular irradiation shape 41 can be scanned across the substrate 80. By irradiating the laser beam 4 having such a rectangular irradiation shape, film penetration due to overprocessing can be more reliably prevented.

[0167] In particular, by performing rectangular irradiation, for example, compared with the overlapping irradiation of circular irradiation, the efficiency can be better, and the position or number of microscopic overlapping irradiations can be controlled more accurately.

[0168] In addition, it is preferable that during the irradiation of multiple emissions in the first direction 80X and / or the second direction 80Y, the laser beam 4 is irradiated without stopping the mask 21 and the substrate 80.

[0169] As described above, ablation processing can be performed more efficiently.

[0170] In addition, when using the mask 21, it can be: as the mask 21, use the first mask and the second mask, perform irradiation of multiple emissions using the first mask, and then replace the first mask with the second mask, and use the second mask to perform irradiation of multiple emissions in such a way that a part of the substrate irradiation area of the substrate 80 overlaps with a part of the substrate irradiation area generated by the irradiation of multiple emissions using the first mask in the first direction.

[0171] For example, the first mask can also be used to perform Figure 6 the first row 41-1 to the fourth row 41-4 of the overlapping irradiation shown, and use the second mask replaced with the first mask to perform Figure 6 the fifth row 41-5 to the eighth row 41-8 of the overlapping irradiation shown. In this case, the first mask and the second mask can also be arranged along the second direction 80Y with respect to the substrate 80.

[0172] In addition, in this case, it can be: during the irradiation of multiple emissions using the first mask, perform laser beam irradiation without stopping the first mask and the substrate 80, and during the irradiation of multiple emissions using the second mask, perform laser beam irradiation without stopping the second mask and the substrate 80.

[0173] In this way, in the ablation processing method of the present invention, during the process of using the first mask, laser beam irradiation can be performed without stopping using the first mask and the substrate 80, and during the process of using the second mask, laser beam irradiation can be performed without stopping using the second mask and the substrate 80. As described above, ablation processing can be performed more efficiently and reliably.

[0174] Or, when using two or more masks, it can also be carried out in accordance with the Figure 9 flowchart shown, as Figure 10 shown for ablation processing.

[0175] In Figure 9 and Figure 10 the ablation processing method of the example shown, first, perform relative positioning of the first mask with respect to the substrate 80.

[0176] Using the positioned first mask, perform scanning processing using the first mask as Figure 10 (a) shown. The scanning processing here, for example, adopts overlapping irradiation under the program shown in Figure 8 (a) to (g), but is not limited thereto. Thus, a concave portion 83A corresponding to the mask irradiation area of the first mask can be formed.

[0177] Next, the first mask and the second mask are replaced, and the starting position of substrate processing is changed so that the substrate processing positions have the following positional relationship: The predetermined recess 83B to be processed next is exactly adjacent and joined to the recess 83A that has been processed previously. The example is a representative example of moving the substrate processing position in the first direction 80X.

[0178] Next, relative positioning of the second mask with respect to the substrate 80 is performed.

[0179] Using the positioned second mask, as Figure 10 shown in (b), scanning processing using the second mask is performed. The scanning processing here, for example, employs Figure 8 overlapping irradiation under the procedures shown in (a) to (g), but is not limited thereto. Thereby, a recess 83B corresponding to the mask irradiation area of the second mask can be formed.

[0180] Then, as needed, for example, similar to Figure 5 and Figure 6 shown, ablation processing by overlapping irradiation is also repeatedly performed in the first direction 80X and the second direction 80Y.

[0181] Then, finally, splicing is completed, and as Figure 10 shown in (c), a target recess 83C can be formed on the surface of the substrate 80.

[0182] By using two or more masks while changing the substrate processing position in this way, the processed area of a substrate larger than the substrate processing area corresponding to the effective area of the mask can be processed by bonding processing.

[0183] Figure 1 The controller 90 shown, for example, is configured to control and perform the overlapping irradiation described above. For example, in the Figure 1 shown ablation processing apparatus 100, the controller 90 is electrically connected to the mask 21 and the substrate stage 40. Preferably, the controller is further configured to: Further, in a plane direction substantially perpendicular to the irradiation direction of the laser beam 4, synchronously move the mask stage (not shown) supporting the mask 21 and the substrate stage 40 (for example, synchronize the movement on the sweep axis 21X with the movement on the sweep axis 80X, and synchronize the movement on the sweep axis 21Y with the movement on the sweep axis 80Y).

[0184] In addition, Figure 1The ablation processing apparatus 100 shown includes a mask alignment camera 23 as an imaging unit for reading the characteristic portions of the mask 21, and a substrate alignment camera 60 as an imaging unit for reading the characteristic portions of the substrate 80. The mask alignment camera 23 is configured to send the position information of the characteristic portions of the mask 21 to the controller 90. The substrate alignment camera 60 is configured to send the position information of the characteristic portions of the substrate 80 to the controller 90. The controller 90 is configured to align the relative positions of the substrate 80 and the mask 21 based on this position information.

[0185] Figure 1 The ablation processing apparatus 100 shown further includes a third optical functional unit 30 including an arbitrary reduction projection optical system 31 between the second optical functional unit 20 and the substrate stage 40.

[0186] In recent years, the miniaturization of substrate processing has been promoted, and several micrometers are required as the minimum width of the processing. It also has an impact on fine dust. In particular, fine dust attached to the mask portion can cause a large number of processing defects. Therefore, the mask 21 is enlarged in advance compared with the actual processing, and the laser beam 3 passing through the mask 21 is reduced and projected for exposure by the subsequent reduction projection optical system 31, thereby minimizing the impact on fine dust.

[0187] In addition, by enlarging the mask 21 in advance compared with the actual processing pattern, the energy of the laser beam 2 reaching the mask 21 can be made smaller than the processing energy. If the reduction ratio of the reduction projection optical system 31 is set to N, the energy of the laser beam reaching the mask surface becomes 1 / (N 2 ). Thus, thermal drift caused by the energy of the laser beam 2 can be suppressed, and therefore thermal expansion of the mask 21 can be suppressed, and high-precision processing can be performed even after a long processing operation.

[0188] Furthermore, deterioration of optical components (for example, the shaping optical system 12 and the mask 21) caused by the heat of the laser beam can also be suppressed, and thus the life of the optical components can be extended.

[0189] The reduction projection optical system 31 may include a pair of reduction projection lenses. In the case where the reduction projection optical system 31 is an infinity optical system, the magnification based on the reduction projection optical system 31 can be adjusted, for example, by the ratio of the focal lengths of the reduction projection lenses and the distance between the reduction projection lenses.

[0190] The numerical aperture (NA) of the reduction projection lens is preferably selected according to the energy density required in the processing of the substrate 80. The NA of the reduction projection lens is preferably 0.12 or more.

[0191] The third optical functional unit 30 preferably further includes a temperature adjustment unit for adjusting the temperature of the reduction projection optical system 31.

[0192] By including the temperature adjustment unit, the influence of heat caused by the laser beam energy in the reduction projection optical system 30 can be further suppressed. In the reduction projection optical system 30, since the laser beam 3 passing through the mask 21 is reduced and projected by 1 / N, the energy of the laser beam that will pass through the lens portion at the solid front end becomes N 2 times that of the laser beam energy irradiated onto the mask 21, and heat influence is likely to occur in this portion. Therefore, in order to suppress the thermal energy, a temperature adjustment function is given to the reduction projection optical system 30, whereby thermal drift caused by the energy of the laser beam can be suppressed, and high-precision processing can be performed even after a long-time processing operation.

[0193] Moreover, in the ablation processing method and ablation processing apparatus of the present invention, a reduction projection lens with a very small aperture can be used. The temperature adjustment unit of the reduction projection lens does not directly give a temperature adjustment unit to the lens itself, but cools the sheath portion that holds the lens. Therefore, if the lens aperture becomes larger, although temperature management can be performed in the peripheral portion of the lens, it is difficult to spread the temperature adjustment effect near the crucial central portion, making it difficult to perform thermal management. Therefore, even for a minute energy absorption in the lens caused by long-time laser beam irradiation, distortion caused by heat is likely to occur. If the third optical functional unit 30 has a temperature adjustment function, the lens aperture can be reduced, thus suppressing such an adverse situation.

[0194] Furthermore, it is also possible to suppress the adverse effects caused by laser beam irradiation in the reduction projection optical system 31, thereby extending the life.

[0195] Figure 1 The ablation processing apparatus 100 shown further includes an arbitrary beam image detection camera 70 in addition to an arbitrary mask alignment camera 23 and an arbitrary substrate alignment camera 60.

[0196] Regarding the processing shape of the substrate 80, the shape of the projected image of the pattern of the mask 21 is not limited to being exactly a similar shape, and furthermore, due to the influence of thermal expansion, etc., the magnification is not limited to being always the same. In addition, due to minute strain or deformation of the substrate 80, etc., there is sometimes a need to deform the processing shape of the substrate 80 relative to the projected image of the mask 21.

[0197] Therefore, the positions of the mask 21 and the substrate 80 are obtained by the mask alignment camera 23 and the substrate alignment camera 60, and based on this information, the projected image of the mask 21 is aligned with the shape to be processed of the substrate, whereby accurate concavo-convex processing of the substrate can be performed.

[0198] Specifically, for example, the projection position of the projected image of the mask 21 is obtained by the beam image detection camera 70, and correction is performed based on the information of the projection position to optimize the projection magnification based on the third optical functional unit 30. In addition, based on the information, the scanning speed during ablation processing is optimized. Thereby, within a certain range, the longitudinal magnification and the lateral magnification of the image of the substrate 80 with respect to the mask 21 can be arbitrarily changed, and thus the optimal substrate processing shape can be applied.

[0199] In the ablation processing method and ablation processing apparatus of the present invention, the substrate to be processed is not particularly limited. For example, a semiconductor package substrate can be used as the processing object.

[0200] Especially in the case of processing a semiconductor package substrate, there are processing patterns such as the coexistence of via hole processing and groove processing. In such a case, the processing can be performed in the same process by the method of the present invention without being divided into the processes of via hole processing and groove processing.

[0201] In addition, the semiconductor package substrate is being advanced in high density. In the laser drilling method in the via hole processing performed hitherto, since the processing time becomes longer due to the increase in the number of hole processes accompanying the high density, in this method, there is no increase in the processing time caused by the increase in the number of hole processes or the high refinement of the pattern.

[0202] The component of the processed region constituting the substrate is not particularly limited. For example, epoxy resin, polyimide resin, acrylonitrile-butadiene-styrene copolymer resin (ABS (Acrylonitrile Butadiene Styrene) resin) can be cited.

[0203] In addition, in the present invention, for example, an excimer laser can be used as the laser beam.

[0204] In one emission of the pulsed excimer laser beam irradiation, a recess with a depth of about 0.5 μm can be formed in the processed region on the surface of the substrate containing these materials. In the present invention, the target depth is divided into the number of emissions of the laser beam, and overlapping irradiation is performed in such a way that the processing depth does not exceed the specified depth. Thereby, in the present invention, a pattern of a recess with a target depth can be obtained with a simple program while preventing film penetration due to overprocessing.

[0205] In addition, by using an excimer laser, the processing surface of a substrate containing an organic material such as an ABF substrate can be efficiently ablated, achieving high-productivity processing. Moreover, since the interferability of the excimer laser is low, by using an excimer laser, the position or number of microscopic overlapping irradiations can be more accurately controlled.

[0206] [Substrate]

[0207] The substrate of the present invention is, for example, the substrate 80 whose cross-section is shown in Figure 8 (g). More specifically, the substrate 80 has a recess 83z serving as a groove (trench), and the bottom of the groove 83z has a plurality of recesses 86 periodically arranged in the length direction 86A of the groove 83z.

[0208] In such a substrate 80, an anchoring effect can be exerted, that is, the plurality of recesses 86 periodically arranged in the length direction 86A of the groove 83z fix a layer or the like formed thereon, thereby high reliability can be exerted. If such a substrate is used, it is not easy to cause the peeling of the buried conductive layer that may occur in the plating process or CMP etc. after the ablation process of the present invention. In the finally processed product, it is also possible to provide a high-quality product with high resistance to stress caused by thermal cycling etc.

[0209] In addition, due to the presence of the plurality of recesses 86, a preferable change in conductivity can be presented.

[0210] The substrate 80 of the present invention is, for example, a semiconductor package substrate, but is not limited thereto.

[0211] [Manufacturing method of substrate]

[0212] An example of the manufacturing method of the substrate of the present invention is a processing method including a series of processes schematically shown in Figure 8 . The manufacturing method of the substrate of the present invention can also be referred to as a form of the ablation processing method of the present invention.

[0213] If referring again to Figure 1 , Figure 2 and Figure 8To summarize, the method for manufacturing the substrate of the present invention is a method for manufacturing a substrate 80 having a groove 83z on its surface by ablation processing using the irradiation energy of a laser beam. Among them, the irradiation area 41 of the laser beam 4 in a single emission in the substrate 80 is made smaller than the processing area 8 of the substrate 80, and the substrate 80 is irradiated with the laser beam 4 in multiple emissions, thereby irradiating the entire surface of the processing area 8 of the substrate 80 with the laser beam. During the multiple emissions of irradiation, while causing the irradiation area 41 of the laser beam to relatively move in the first direction 80X of the substrate 80 and the second direction 80Y orthogonal to the first direction 80X with respect to the substrate 80, and in such a manner that a groove 83z having a depth within a specified range is formed in the processing area 8 of the substrate 80, a part of the irradiation area 41 in each emission overlaps with the irradiation area 41 in other emissions in the first direction 80X and the second direction 80Y, and the multiple emissions of irradiation are performed in such a way that irradiation areas with different overlap frequencies are respectively provided in the first direction 80X and the second direction 80Y, thereby manufacturing a substrate in which the bottom of the groove 83z has a plurality of recesses 86 periodically arranged in the length direction 86A of the groove 83z.

[0214] Through the method for manufacturing the substrate, the substrate of the present invention can be manufactured.

[0215] In addition, through the ablation method of the present invention, a substrate as shown in Figure 8 (g), in which the bottom of the groove 83z has a plurality of recesses 86 periodically arranged in the length direction 86A of the groove 83z, can be manufactured, but a substrate in which no plurality of recesses are formed at the bottom of the groove 83z as shown in Figure 7 (g) can also be manufactured.

[0216] Hereinafter, the control of the formation of the recesses in the groove will be described.

[0217] In Figure 11 , an example of the overlapping irradiation based on the present invention for forming the recess 86 in the groove 8a formed in the processing area 8 is shown. The left is a schematic plan view of the irradiation area 41, the right is a schematic plan view of the first row 41-1 and the second row 41-2 of the overlapping irradiation performed on the processing area 8, and the center is a schematic cross-sectional view of the processing area 8 after the first row 41-1 and the second row 41-2 of the overlapping irradiation.

[0218] Figure 11 The overlapping irradiation shown is an example of the sweeping overlapping irradiation of a rectangular irradiation area 41 performed regularly. More specifically, in Figure 11In the overlapping irradiation shown, the long side of the rectangular irradiation region 41 is parallel to the second direction 80Y, and the short side is parallel to the first direction 80X. While making a part overlap with the first row 41-1 of the overlapping irradiation along the first direction 80X in the direction parallel to the second direction 80Y, the second row 41-2 of the overlapping irradiation along the first direction 80X is performed. In the overlapping portion 41a between the first row 41-1 and the second row 41-2, a concave portion 86 within a specified depth range is formed.

[0219] On the other hand, for example, as Figure 12 shown, if the long side of the rectangular irradiation region 41 is inclined with respect to the second direction 80Y, and while making a part overlap with the first row 41-1 of the overlapping irradiation along the first direction 80X in the direction parallel to the second direction 80Y, the second row 41-2 of the overlapping irradiation along the first direction 80X is performed, then the number of overlapping times in the overlapping portion 41b between the first row 41-1 and the second row 41-2 is less than Figure 11 the number of overlapping times in the overlapping portion 41a in the example of Figure 12 shown. Thus, as Figure 11 shown, the situation where a concave portion 86 is formed in the groove 8a as formed in the example of

[0220] The inclination of the irradiation region 41 can be achieved, for example, by making the laser beam inclined relative to the moving directions of the photomask and the substrate (such as Figure 1 shown 21X, 21Y, 80X, and 80Y). The member that actually undergoes inclination is the photomask or the stage, and it is not necessarily required to adjust the laser beam itself.

[0221] The means for suppressing the formation of the concave portion is not limited to Figure 12 the example shown, and for example, it can also be Figure 13 the example shown and other methods. In Figure 13 the example shown, the laser beam is obliquely truncated before and after the photomask to deform the irradiation region 41. For example, metal plates 24 are placed on one side or both sides of the photomask. As Figure 13 shown, if the irradiation region 41 is deformed, and while making a part overlap with the first row 41-1 of the overlapping irradiation along the first direction 80X in the direction parallel to the second direction 80Y, the second row 41-2 of the overlapping irradiation along the first direction 80X is performed, then the number of overlapping times in the overlapping portion 41c between the first row 41-1 and the second row 41-2 is less than Figure 11 the number of overlapping times in the overlapping portion 41a in the example of

[0222] In addition, as Figure 14As shown, if the second row 41-2 of overlapping irradiation can be performed in such a way that it does not overlap with the first row 41-1 of overlapping irradiation along the first direction 80X in the second direction 80Y, that is, in a non-overlapping manner in the region 41d, the formation of recesses in the groove can be completely prevented. However, it is difficult to perform such control for overlapping irradiation in reality. For example, sometimes, as Figure 15 (a) shows, a completely non-overlapping offset portion 41e is generated between the first row 41-1 and the second row 41-2, or sometimes, as Figure 15 (b) shows, the first row 41-1 and the second row 41-2 overlap in the overlapping portion 41f.

[0223] On the other hand, for example, in the case where the formation of recesses at the bottom can be suppressed to a desired level or below when performing up to quadruple irradiation to form a groove, as in the example of Figure 16 , for the first row 41-1 and the second row 41-2 of overlapping irradiation by tilting the irradiation region, the number of overlaps in the overlapping portion 41e becomes four times, and the depth of the bottom of the groove is not completely uniform, but the formation of the recess 86 can be suppressed to a desired level or below. In the method of deforming the irradiation region 41 as in Figure 13 , the formation of recesses can also be suppressed.

[0224] As for the substrate 80 described with reference to Figure 8 (g), if the bottom of the groove 83z has a plurality of recesses 86, an anchoring effect on metal electrodes or the like embedded in the termination processing (grooving processing) portion can be exerted. In addition, in the ablation processing method of the present invention, since recesses with a depth within a specified range are formed in the processed region of the substrate, overprocessing of the substrate or a situation where the processing depth is insufficient can be prevented.

[0225] On the other hand, as shown in Figure 7 (g), by suppressing the formation of recesses at the bottom to form the groove 83z, the situation of penetrating the substrate 80 to be processed or defective conditions (such as an increase in electrode resistance) caused by insufficient processing depth can be more reliably prevented.

[0226] Moreover, by, for example, referring to the methods described in Figure 12 , Figure 13 and Figure 16 , the bottom uneven state at the joint portion of the ablation processing can be controlled, and its uneven shape can be alleviated, so high-quality termination (grooving) processing can be performed.

[0227] This specification includes the following embodiments.

[0228] [1] An ablation processing method forms recesses on the surface of a substrate through ablation processing using the irradiation energy of a laser beam. In this ablation processing method, the irradiation area of the laser beam in the primary emission in the substrate is made smaller than the processing area of the substrate, and the substrate is irradiated with the laser beam in multiple emissions, thereby irradiating the entire surface of the processing area of the substrate with the laser beam. In the multiple emissions irradiation, while causing the irradiation area of the laser beam to relatively move with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, a recess having a depth within a specified range is formed in the processing area of the substrate, and a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction.

[0229] [2] The ablation processing method according to [1], wherein, in the multiple emissions irradiation, a light source and a mask are used. The light source oscillates the laser beam, and the mask includes an effective area having a pattern corresponding to the recess to be formed in the substrate. The laser beam from the light source is irradiated onto a mask irradiation area that is a part of the effective area of the mask, and the laser beam that has passed through the mask is irradiated onto a substrate irradiation area that is at least a part of the processing area of the substrate, and the pattern is projected onto the substrate irradiation area to perform ablation processing. When the irradiation area of the laser beam relatively moves with respect to the substrate, the mask and the substrate are synchronously shifted in a plane direction substantially perpendicular to the irradiation direction of the laser beam.

[0230] [3] The ablation processing method according to [2], wherein the laser beam having a rectangular irradiation shape is irradiated onto the mask irradiation area of the mask.

[0231] [4] The ablation processing method according to [2] or [3], wherein, during the multiple emissions irradiation in the first direction and / or the second direction, the laser beam irradiation is performed without stopping the mask and the substrate.

[0232] [5] The ablation processing method according to any one of [2] to [4], wherein, as the mask, a first mask and a second mask are used. The multiple emissions irradiation is performed using the first mask, and then the first mask is replaced with the second mask, and the multiple emissions irradiation is performed using the second mask in such a manner that a part of the substrate irradiation area of the substrate overlaps with a part of the substrate irradiation area generated by the multiple emissions irradiation using the first mask in the first direction.

[0233] [6] The ablation processing method according to any one of [1] to [5], wherein an excimer laser is used as the laser beam.

[0234] [7] The ablation processing method according to any one of [1] to [6], wherein an ablation process is performed on a semiconductor package substrate as the substrate.

[0235] [8] An ablation processing apparatus that forms a recess on the surface of a substrate by ablation processing using the irradiation energy of a laser beam. The ablation processing apparatus includes: a light source that oscillates the laser beam; a substrate stage that supports the substrate; and a controller that is configured to perform the following control: making the irradiation area of the laser beam in one emission in the substrate smaller than the processing area of the substrate, and performing multiple emissions of the laser beam on the substrate, thereby irradiating the entire surface of the processing area of the substrate with the laser beam. In the multiple emissions of irradiation, while relatively moving the irradiation area of the laser beam with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, and in such a manner that a recess having a depth within a specified range is formed in the processing area of the substrate, a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction.

[0236] [9] The ablation processing apparatus according to [8], further including: a mask that includes an effective area having a pattern corresponding to the processing area of the substrate; and a mask stage that supports the mask. The controller is further configured to: further, in a plane direction substantially perpendicular to the irradiation direction of the laser beam, synchronously move the mask stage and the substrate stage.

[0237]

[10] The ablation processing apparatus according to [9], wherein, between the light source and the mask, a shaping optical system is further included, and the shaping optical system shapes the irradiation shape of the laser beam into a rectangular irradiation shape.

[0238]

[11] The ablation processing apparatus according to any one of [8] to

[10] , wherein the light source is an excimer laser light source.

[0239]

[12] A substrate having a groove on its surface. In the substrate, the bottom of the groove has a plurality of recesses periodically arranged in the length direction of the groove.

[0240]

[13] The substrate according to

[12] , which is a semiconductor package substrate.

[0241]

[14] A method for manufacturing a substrate, which manufactures a substrate having grooves on the surface by ablation processing using the irradiation energy of a laser beam. In this method, the irradiation area of the laser beam in the first emission in the substrate is made smaller than the processing area of the substrate, and the substrate is irradiated with the laser beam in multiple emissions, whereby the entire surface of the processing area of the substrate is irradiated with the laser beam. In the multiple emissions, while relatively moving the irradiation area of the laser beam with respect to the substrate in the first direction of the substrate and the second direction orthogonal to the first direction respectively, in such a manner that grooves having a depth within a specified range are formed in the processing area of the substrate, a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction, and the multiple emissions are performed in such a manner that irradiation areas with different overlap numbers are provided in the first direction and the second direction respectively, thereby manufacturing a substrate in which a plurality of recesses are periodically arranged in the length direction of the bottom of the groove.

[0242] In addition, the present invention is not limited to the above-described embodiments. The above-described embodiments are illustrative, and any manner having a structure substantially the same as the technical idea described in the claims of the present invention and achieving the same effects is included in the technical scope of the present invention.

Claims

1. An ablation processing method, in which a concave portion is formed on the surface of a substrate by ablation processing using the irradiation energy of a laser beam. In the ablation processing method, the irradiation area of the laser beam in a single emission in the substrate is made smaller than the processing area of the substrate, and the substrate is irradiated with the laser beam in multiple emissions, whereby the entire surface of the processing area of the substrate is irradiated with the laser beam. In the irradiation in multiple emissions, while the irradiation area of the laser beam is relatively moved with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, the ablation is performed in such a manner that a concave portion having a depth within a specified range is formed in the processing area of the substrate, and a part of the irradiation area in each emission overlaps with the irradiation area in other emissions in the first direction and the second direction.

2. The ablation processing method according to claim 1, wherein, In the irradiation in multiple emissions, a light source and a mask are used. The light source oscillates the laser beam, and the mask includes an effective area having a pattern corresponding to the concave portion to be formed in the substrate. The laser beam from the light source is irradiated onto a mask irradiation area that is a part of the effective area of the mask. The laser beam that has passed through the mask is irradiated onto a substrate irradiation area that is at least a part of the processing area of the substrate, and the pattern is projected onto the substrate irradiation area to perform ablation processing. When the irradiation area of the laser beam is relatively moved with respect to the substrate, the mask and the substrate are synchronously shifted in a plane direction substantially perpendicular to the irradiation direction of the laser beam.

3. The ablation processing method according to claim 2, wherein, The mask irradiation area of the mask is irradiated with the laser beam having a rectangular irradiation shape.

4. The ablation processing method according to claim 2, wherein, During the irradiation in multiple emissions in the first direction and / or the second direction, the laser beam irradiation is performed without stopping the mask and the substrate.

5. The ablation processing method according to any one of claims 2 to 4, wherein, As the mask, a first mask and a second mask are used. The irradiation in multiple emissions is performed using the first mask. Next, the first mask is replaced with the second mask. Using the second mask, the irradiation in multiple emissions is performed in such a manner that a part of the substrate irradiation area of the substrate overlaps with a part of the substrate irradiation area generated by the irradiation in multiple emissions using the first mask in the first direction.

6. The ablation processing method according to any one of claims 1 to 4, wherein, An excimer laser is used as the laser beam.

7. The ablation processing method according to any one of claims 1 to 4, wherein, A semiconductor package substrate as the substrate is subjected to ablation processing.

8. An ablation processing apparatus, in which a concave portion is formed on the surface of a substrate by ablation processing using the irradiation energy of a laser beam. The ablation processing apparatus includes: a light source that oscillates the laser beam; a substrate stage that supports the substrate; and a controller, wherein the controller is configured to perform the following control: The irradiation area of the laser beam in a single emission in the substrate is made smaller than the processing area of the substrate, and the substrate is irradiated with the laser beam in multiple emissions, whereby the entire surface of the processing area of the substrate is irradiated with the laser beam. In the irradiation of the multiple emissions, while relatively moving the irradiation region of the laser beam with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, the irradiation region of each emission is overlapped with the irradiation region of other emissions in the first direction and the second direction in such a manner that a recess having a depth within a specified range is formed in the processed region of the substrate.

9. The ablation processing apparatus according to claim 8, further comprising: a mask including an effective region having a pattern corresponding to the processed region of the substrate; and a mask stage for supporting the mask, the controller is further configured to: further, in a plane direction substantially perpendicular to the irradiation direction of the laser beam, synchronously move the mask stage and the substrate stage.

10. The ablation processing apparatus according to claim 9, wherein, Between the light source and the mask, a shaping optical system is further included, and the shaping optical system shapes the irradiation shape of the laser beam into a rectangular irradiation shape.

11. The ablation processing apparatus according to any one of claims 8 to 10, wherein, The light source is an excimer laser light source.

12. A substrate having a groove on a surface, in the substrate, the bottom of the groove has a plurality of recesses periodically arranged in the length direction of the groove.

13. The substrate according to claim 12, which is a semiconductor package substrate.

14. A method for manufacturing a substrate, which manufactures a substrate having a groove on a surface by ablation processing using the irradiation energy of a laser beam, wherein, the irradiation region of the laser beam in one emission in the substrate is made smaller than the processed region of the substrate, and the substrate is irradiated with the laser beam in multiple emissions, whereby the entire surface of the processed region of the substrate is irradiated with the laser beam, in the irradiation of the multiple emissions, while relatively moving the irradiation region of the laser beam with respect to the substrate in a first direction of the substrate and a second direction orthogonal to the first direction, the irradiation region of each emission is overlapped with the irradiation region of other emissions in the first direction and the second direction in such a manner that a groove having a depth within a specified range is formed in the processed region of the substrate, the irradiation of the multiple emissions is performed in such a manner that the irradiation regions having different overlapping times are respectively provided in the first direction and the second direction, thereby manufacturing a substrate in which the bottom of the groove has a plurality of recesses periodically arranged in the length direction of the groove.

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