Laser processing method, laser processing device and electronic device manufacturing method

Abstract

To provide a laser processing method that enables circuit wiring to be processed more finely.SOLUTION: A laser processing method irradiates a work-piece with a laser beam through a mask. The irradiation through the mask includes irradiation of the work-piece with a laser beam through a first mask pattern on which a first trench pattern including a first pad part and a first via pattern are formed, and irradiation of the work-piece with a laser beam through a second mask pattern on which a second trench pattern and a second via pattern are formed. By the irradiation of the work-piece with a laser beam through the second mask pattern, a second trench processed part that is processed through the second trench pattern is positioned adjacent to a first trench processed part of the work-piece processed through the first trench pattern, and a second via processed part that is processed through the second via pattern is positioned in a first pad processed part of the work-piece processed through the first pad part.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a laser processing method, a laser processing apparatus, and a method for manufacturing an electronic device. [Background technology]

[0002] Circuit boards, which are widely used in various electronic devices, are required to have finer and denser circuit wiring in order to reduce the size and improve the functionality of the electronic devices. A known manufacturing technique for circuit boards is a build-up method in which insulating layers and conductor layers are alternately stacked on an inner layer substrate. In a build-up manufacturing method, an insulating layer is formed by laminating a resin composition layer on an inner layer substrate using, for example, an adhesive layer including a support and a resin composition layer provided on the support, and then thermally curing the resin composition layer. Next, a laser beam is irradiated onto the formed insulating layer to form via holes for connecting the conductor layer. Subsequently, a circuit is formed by seed layer deposition, lithography, plating, and seed layer etching.

[0003] To achieve even higher density circuit wiring, it is desirable to reduce the diameter and width of via holes. Via holes are generally formed by laser drilling, and carbon dioxide gas lasers are currently the most commonly used laser due to their high drilling speed and manufacturing cost advantages. However, there are limits to how small the diameter of via holes can be; for example, it is difficult to form via holes with an opening diameter of 25 μm or less using a carbon dioxide gas laser. Furthermore, in terms of wiring width, it is difficult to achieve a line / space of 2 μm / 2 μm or less in the wiring pattern using semiconductor packaging equipment that uses lithography and etching.

[0004] To further reduce the width of via holes and wiring, the use of excimer lasers instead of carbon dioxide lasers is being considered.

[0005] Excimer laser light has a pulse width of approximately several tens of nanoseconds and short wavelengths of, for example, 248.4 nm and 193.4 nm, and is therefore sometimes used for direct processing of polymeric materials, glass materials, and the like.

[0006] The bonds of polymeric materials can be broken by excimer laser light, which has a photon energy higher than the bond energy. This allows for processing without heating, and is known to produce clean processed shapes.

[0007] Excimer lasers generally emit strong ultraviolet light, and unlike infrared lasers such as carbon dioxide lasers, do not generate heat. This allows for finer processing, and is expected to contribute to the miniaturization of via holes and wiring widths. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-164707 [Patent Document 2] Overview of U.S. Patent No. 6,136,479

[0009] A laser processing method according to one aspect of the present disclosure is a laser processing method in which laser light output from a laser device is irradiated onto a workpiece through a mask, the workpiece including a substrate and an insulating film formed on the substrate, and the irradiation through the mask includes irradiating the workpiece with laser light through a first mask pattern in which a first trench pattern including a first pad portion and a first via pattern are formed, and irradiating the workpiece with laser light through a second mask pattern in which a second trench pattern and a second via pattern are formed, and the irradiating the workpiece with laser light through the second mask pattern includes positioning a second trench processing portion to be processed through the second trench pattern adjacent to the first trench processing portion of the workpiece processed through the first trench pattern, and positioning a second via processing portion to be processed through the second via pattern within the first pad processing portion of the workpiece processed through the first pad portion.

[0010] A method for manufacturing an electronic device according to one aspect of the present disclosure is a method for manufacturing an electronic device, in which laser light output from a laser apparatus is irradiated onto a workpiece through a mask to manufacture the electronic device, wherein the workpiece includes a substrate and an insulating film formed on the substrate, and the irradiation through the mask includes irradiating the workpiece with laser light through a first mask pattern in which a first trench pattern including a first pad portion and a first via pattern are formed, and irradiating the workpiece with laser light through a second mask pattern in which a second trench pattern and a second via pattern are formed, and the irradiating the workpiece with laser light through the second mask pattern includes positioning a second trench processing portion to be processed through the second trench pattern adjacent to the first trench processing portion of the workpiece processed through the first trench pattern, and positioning a second via processing portion to be processed through the second via pattern within the first pad processing portion of the workpiece processed through the first pad portion.

[0011] A laser processing apparatus according to one aspect of the present disclosure is a laser processing apparatus that irradiates a workpiece with laser light output from a laser device through a mask, and includes: a mask mounting member on which a first mask and a second mask are mounted; a mask moving mechanism that moves either the first mask or the second mask mounted on the mask mounting member to a laser light irradiation position; and a processor, wherein the processor moves the first mask to the laser light irradiation position, irradiates the workpiece with the laser light via a first trench pattern and a first via pattern including first pad portions formed on the first mask, and and moving the second mask to a position where the workpiece is irradiated with laser light through the second trench pattern and the second via pattern formed on the second mask, and irradiating the workpiece with laser light through the second trench pattern and the second via pattern includes positioning a second trench processing portion to be processed through the second trench pattern adjacent to the first trench processing portion of the workpiece processed through the first trench pattern, and positioning a second via processing portion to be processed through the second via pattern within the first pad processing portion of the workpiece processed through the first pad portion. [Brief explanation of the drawings]

[0012] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a diagram showing the configuration of a mask transfer type laser processing system according to a comparative example. [Figure 2] FIG. 2 is a plan view showing an example of an illumination beam illuminating a mask. [Figure 3] FIG. 3 is a diagram showing a build-up substrate as an example of the workpiece. [Figure 4] FIG. 4 is a diagram for explaining processing using a plurality of masks according to a comparative example. [Figure 5] FIG. 5 is a flowchart showing steps of a processing method using a trench mask and a via mask. [Figure 6] FIG. 6 is a diagram for explaining shoulder droop. [Figure 7] FIG. 7 is a diagram for explaining processing using a plurality of masks according to the first embodiment. [Figure 8] FIG. 8 is a flowchart showing steps of the processing method according to the first embodiment. [Figure 9] FIG. 9 is a flowchart showing steps of a processing method according to a modified example of the first embodiment. [Figure 10] FIG. 10 is a diagram for explaining the processing method according to the second embodiment. [Figure 11] FIG. 11 is a diagram showing the configuration of a laser processing system 10A according to the third embodiment. [Figure 12] FIG. 12 is a plan view of the mask moving mechanism 138. Embodiment

[0013] -table of contents- 1. Explanation of terms 2. Overview of a mask transfer type laser processing system according to a comparative example 2.1 Configuration 2.2 Operation 2.3 Challenges 3. Embodiment 1 3.1 Configuration 3.2 Operation 3.3 Actions and Effects 3.4 Variations 3.4.1 Configuration and operation 3.4.2 Actions and Effects 4. Embodiment 2 4.1 Configuration 4.2 Operation 4.3 Actions and Effects 5. Embodiment 3 5.1 Configuration 5.2 Operation 5.3 Actions and Effects 6. Manufacturing method of electronic devices 7.Other

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and redundant explanations will be omitted.

[0015] 1. Explanation of terms A "via" is a through hole that penetrates at least one layer of a multi-layer board.

[0016] A "pad" is a portion formed around a via and wider than the via diameter for soldering a lead of an electronic component, and a portion located below the via and wider than the via diameter.

[0017] 2. Overview of a mask transfer type laser processing system according to a comparative example 2.1 Configuration A mask transfer type laser processing system according to a comparative example will be described. Note that the comparative example in the present disclosure is a form that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0018] 1 is a diagram showing the configuration of a mask transfer type laser processing system 10 according to a comparative example. The laser processing system 10 includes a laser device 12, an optical path tube 13, and a laser processing device 14. The optical path tube 13 is disposed on the optical path of the laser light between the exit port of the laser device 12 and the entrance port of the laser processing device 14.

[0019] The laser device 12 is an excimer laser device that outputs ultraviolet pulsed laser light. For example, the laser device 12 may be a discharge-pumped laser device that uses F2, ArF, KrF, XeCl, or XeF as a laser medium. The laser device 12 includes a master oscillator (MO) 20, a monitor module 24, a shutter 26, and a laser processor 28.

[0020] The master oscillator 20 includes a chamber 30 , an optical resonator 32 , a charger 36 , and a pulsed power module (PPM) 38 .

[0021] Excimer laser gas containing a laser medium is sealed inside the chamber 30. The excimer laser gas may be a mixed gas containing a rare gas such as Ar, Kr, or Xe, a halogen gas such as F2 or Cl2, and a buffer gas such as He or Ne.

[0022] The chamber 30 includes a pair of electrodes 44a and 44b and windows 47 and 48. The pair of electrodes 44a and 44b are disposed within the chamber 30. The electrode 44a is supported by an insulating member 45. The electrode 44a is connected to the PPM 38 via a conductive portion 46 embedded in a feedthrough of the insulating member 45. The electrode 44b is supported by a return plate (not shown), and the return plate is connected to the inner surface of the chamber 30 by wiring (not shown).

[0023] The PPM 38 includes a switch 39, a step-up transformer (not shown), and a magnetic compression circuit (not shown). The PPM 38 is connected to a charger 36. The charger 36 is a DC power supply device that charges a charging capacitor (not shown) of the PPM 38 at a predetermined voltage.

[0024] The optical resonator 32 includes a rear mirror 33 and an output coupling mirror 34. The rear mirror 33 has a flat substrate coated with a highly reflective film. The output coupling mirror 34 has a flat substrate coated with a partially reflective film. The chamber 30 is disposed on the optical path of the optical resonator 32.

[0025] The monitor module 24 includes a beam splitter 50 and a light sensor 52 .

[0026] The shutter 26 is disposed on the optical path of the pulsed laser light output from the monitor module 24 .

[0027] The optical path of the pulsed laser light may be sealed by a housing and an optical path tube 13 (not shown), and may be purged with N2 gas or the like.

[0028] The laser processing apparatus 14 includes an irradiation optical system 70, a frame 72, an XYZ stage 74, a table 76, and a laser processing processor 100. A workpiece 160 is fixed on the table 76.

[0029] The illumination optical system 70 includes high-reflection mirrors 111 and 112 , an attenuator 120 , an illumination optical system 130 , a mask 140 , a projection optical system 142 , a window 146 , and a housing 150 .

[0030] High-reflection mirror 111 is arranged so that the laser light that has passed through optical path tube 13 passes through attenuator 120 and is incident on high-reflection mirror 112 .

[0031] Attenuator 120 is disposed on the optical path between high-reflection mirror 111 and high-reflection mirror 112. Attenuator 120 includes two partial reflection mirrors 121 and 122, and rotation stages 123 and 124 that change the angles of incidence of partial reflection mirrors 121 and 122, respectively.

[0032] The high-reflection mirror 112 is disposed so that the laser light that has passed through the attenuator 120 enters the illumination optical system 130 .

[0033] The illumination optical system 130 includes a highly reflective mirror 133, a fly's eye lens 134, and a condenser lens 136. The illumination optical system 130 is arranged to Kohler illuminate the mask 140 with a rectangular illumination beam.

[0034] High-reflection mirror 133 is disposed so that the incident pulsed laser light is incident on fly-eye lens 134 .

[0035] The fly-eye lens 134 is disposed, for example, such that the focal plane of the fly-eye lens 134 coincides with the front focal plane of the condenser lens 136. The condenser lens 136 is disposed, for example, such that the rear focal plane of the condenser lens 136 coincides with the position of the mask 140. The illumination optical system 130 is disposed such that the laser light is uniformly irradiated onto the mask 140.

[0036] The mask 140 is, for example, a mask in which a pattern of a metal or dielectric multilayer film is formed on a synthetic quartz substrate that transmits ultraviolet light. For example, when via holes are to be formed in a workpiece 160 that is a printed circuit board, a pattern for forming holes with a diameter of 5 μm to 30 μm is formed on the mask 140. If the magnification of the projection optical system 142 for the processing dimension is M, a pattern that is 1 / M times the processing dimension is formed on the mask 140.

[0037] The projection optical system 142 is arranged so that an image of the mask 140 is formed on the surface of the workpiece 160 through a window 146. The projection optical system 142 may be a combination of multiple lenses 144, and may be a reduction projection optical system.

[0038] The window 146 is disposed on the optical path between the projection optical system 142 and the workpiece 160. The window 146 is disposed in a hole provided in the housing 150 via an O-ring or the like (not shown). The window 146 is a CaF2 crystal or synthetic quartz substrate that transmits excimer laser light, and may be coated with an anti-reflection film on both sides.

[0039] The housing 150 is provided with a nitrogen (N2) gas inlet 152 and outlet 154. The housing 150 may be sealed with an O-ring or the like (not shown) to prevent outside air from entering the housing 150. The N2 gas inlet 152 is connected to an N2 gas supply source.

[0040] The irradiation optical system 70 and the XYZ stage 74 are fixed to the frame 72. The XYZ stage 74 is an electric stage that relatively moves the irradiation position of the pulsed laser beam with respect to the workpiece 160. The table 76 is fixed on the XYZ stage 74. The workpiece 160 is fixed on the table 76.

[0041] The workpiece 160 may be, for example, an interposer substrate or a flexible printed board that relays between an LSI chip and a main printed board. The electrical insulating film material of this substrate includes a polymer material, a glass epoxy material, or a glass material.

[0042] FIG. 2 is a plan view showing an example of an irradiation beam that illuminates the mask 140. As shown in FIG. 2, let the width of the irradiation beam in the X direction be Bx and the width in the Y direction be By. The example shown in FIG. 2 is a rectangular irradiation beam that satisfies Bx < By.

[0043] 2.2 Operation The user sets an appropriate mask 140 in the laser processing apparatus 14 in advance.

[0044] The laser processing processor 100 reads the irradiation condition parameters during laser processing. Specifically, it reads the fluence on the workpiece 160 when performing laser processing, the number of irradiation pulses, and the repetition frequency. The irradiation conditions may include at least one of fluence, the number of irradiation pulses, and the repetition frequency.

[0045] The laser processing processor 100 causes the laser device 12 to perform adjusted oscillation. For this purpose, the laser processing processor 100 transmits the target pulse energy Et to the laser processor 28.

[0046] When the laser processor 28 receives the target pulse energy Et, it closes the shutter 26 and controls the charger 36 to achieve the target pulse energy Et. The laser processor 28 generates an internal trigger signal using an internal trigger generating unit (not shown). The generated internal trigger signal is input to a switch 39 of the PPM 38, causing the master oscillator 20 to naturally oscillate.

[0047] The pulsed laser light output from the master oscillator 20 is sampled by the beam splitter 50 of the monitor module 24, and the pulse energy E is measured.

[0048] The laser processor 28 controls the charging voltage of the charger 36 so that the difference ΔE between the pulse energy E and the target pulse energy Et approaches zero.

[0049] When ΔE falls within the allowable range, the laser processor 28 sends an external trigger OK signal to the laser processing processor 100 and opens the shutter 26 .

[0050] The laser processing processor 100 receives an external trigger OK signal from the laser processor 28 .

[0051] The laser processing processor 100 then controls the X and Y axes of the XYZ stage 74 so that the irradiation area onto which the image of the mask 140 is transferred by the projection optical system 142 is positioned at an appropriate position on the workpiece 160 .

[0052] The laser processing processor 100 controls the Z axis of the XYZ stage 74 so that the image of the mask 140 is focused at the position on the surface of the workpiece 160 .

[0053] The laser processing processor 100 controls the angles of incidence of the two partial reflection mirrors 121 and 122 using the respective rotation stages 123 and 124 so that the fluence of the pulsed laser light at the surface position of the workpiece 160 (the position of the image of the mask 140) becomes the target fluence.

[0054] The laser processing processor 100 transmits a light emission trigger signal Tr at a predetermined repetition frequency to the laser processor 28. As a result, a pulsed laser beam is output from the master oscillator 20 in synchronization with the light emission trigger signal Tr. The pulsed laser beam transmitted through the beam splitter 50 of the monitor module 24 enters the laser processing device 14 via the optical path tube 13.

[0055] The pulsed laser light incident on the laser processing device 14 is reflected by the high-reflection mirror 111 , passes through the attenuator 120 to be attenuated, and is then reflected by the high-reflection mirror 112 .

[0056] The pulsed laser light highly reflected by the high-reflection mirror 112 is reflected by the high-reflection mirror 133 of the illumination optical system 130, and the light intensity is spatially uniformed by the fly-eye lens 134, before it is incident on the mask 140 as an irradiation beam.

[0057] The pulsed laser light that has passed through the mask 140 enters the projection optical system 142. The pulsed laser light that has passed through the projection optical system 142 is reduced and projected (transfer image formed) and irradiated onto the surface of the workpiece 160. As a result, the portion of the surface of the workpiece 160 that has been irradiated with the pulsed laser light is laser processed.

[0058] 2.3 Challenges Fig. 3 is a diagram showing a buildup substrate 200, which is an example of the workpiece 160. F3A in Fig. 3 is a plan view of the processed buildup substrate 200. F3B in Fig. 3 is a cross-sectional view taken along line 3B-3B of F3A.

[0059] The build-up substrate 200 has an insulating film 204 made of a polymer material or the like laminated on the upper surface of a substrate 202. The build-up substrate 200 also has a trench 210, a pad 212, and a via 214 formed in the insulating film 204.

[0060] The via 214 penetrates the insulating film 204. The trench 210 and the pad 212 are recesses formed by removing a portion of the insulating film 204. The pad 212 is formed around the via 214. The trench 210 connects the two pads 212. In F3B, the lateral positions of the trench 210, the pad 212, and the via 214 are appropriately changed to facilitate understanding.

[0061] When processing the buildup substrate 200 shown in Fig. 3, processing may be performed in a plurality of steps using a plurality of masks. Fig. 4 is a diagram for explaining processing using a plurality of masks according to a comparative example.

[0062] F4A is a top view of the trench mask 300. The trench mask 300 has a trench pattern 302 and a pad pattern 304, which are laser light transmitting regions corresponding to the trenches 210 and pads 212, respectively, to be processed in the insulating film 204 of the build-up substrate 200.

[0063] F4B shows the buildup substrate 200 processed using the trench mask 300, and is a cross-sectional view taken along line 4B of F4A. As shown in F4B, the insulating film 204 of the buildup substrate 200 is provided with a trench processing portion 220 processed by the pulsed laser light that has passed through the trench pattern 302, and a pad processing portion 222 processed by the pulsed laser light that has passed through the pad pattern 304. The trench processing portion 220 and the pad processing portion 222 are recesses formed by removing the insulating film 204 partway through its thickness.

[0064] F4C is a top view of the via mask 310. The via mask 310 has a via pattern 312, which is a laser light transmitting region corresponding to the via 214 to be processed in the insulating film 204 of the build-up substrate 200.

[0065] F4D shows the buildup substrate 200 processed using the via mask 310, and is a cross-sectional view taken along line F4D of F4C. As shown in F4D, a via processing portion 224 is formed in the insulating film 204 of the buildup substrate 200 by processing the via with the pulsed laser light that has passed through the via pattern 312. The via processing portion 224 is a through-hole that penetrates the insulating film 204.

[0066] 3 can be produced by processing using the trench mask 300 and then switching to the via mask 310. In this case, the insulating film 204 needs to be left uncut in the trench processing portion 220 and the pad processing portion 222, and the number of times and fluence of the laser light irradiation may be adjusted. On the other hand, the insulating film 204 needs to be cut through in the via processing portion 224, and the laser light irradiation conditions may be different from those when the trench mask 300 is used.

[0067] FIG. 5 is a flowchart showing steps of a processing method using a trench mask 300 and a via mask 310.

[0068] In step S1, the user sets the trench mask 300 in the laser processing device 14. In step S2, the laser processing processor 100 sets the irradiation conditions to irradiation conditions 1. In step S3, the laser processing device 14 irradiates the surface of the build-up substrate 200 with pulsed laser light through the trench mask 300 to perform processing.

[0069] As a result, a trench 210 and a pad 212 are formed in the insulating film 204 .

[0070] In step S4, the user sets the via mask 310 in the laser processing device 14. In step S5, the laser processing processor 100 sets the irradiation conditions to irradiation conditions 2. In step S6, the laser processing device 14 irradiates the surface of the build-up substrate 200 with pulsed laser light through the via mask 310 to perform processing.

[0071] As a result, vias 214 are formed in the insulating film 204. This completes the processing of the flowchart.

[0072] In processing such a build-up substrate 200, the need for miniaturization has increased in recent years, and so-called shoulder droop may occur, for example, where the angle of the end of the insulating film 204 left on both sides of the trench 210, which should be formed at a right angle, becomes inclined.

[0073] Fig. 6 is a diagram illustrating shoulder sagging. F6A in Fig. 6 is the same as F4B in Fig. 4 and shows a build-up substrate 200 in which a trench processing portion 220 has been processed using a trench mask 300. F6B in Fig. 6 is a partially enlarged view of F6A, showing the upper part of the trench processing portion 220. In the example shown in F6B, shoulder sagging 221 has occurred in the insulating film 204 on both sides of the trench processing portion 220.

[0074] This shoulder droop occurs when the distance between adjacent linear processed parts becomes too close and the mask's light shielding (remaining part) becomes insufficient due to the limit of resolution. Double patterning of the trench pattern alone can be considered to suppress the shoulder droop, but this has the disadvantage of increasing the number of masks required.

[0075] Therefore, there was a need for a processing method that could suppress shoulder droop while suppressing an increase in the number of masks even with miniaturization.

[0076] 3. Embodiment 1 3.1 Configuration The configuration of the laser processing system of the first embodiment is similar to that of the laser processing system 10 of the comparative example. In the first embodiment, instead of processing only the trench pattern and processing only the via pattern, laser processing is performed using a plurality of masks on which both the trench pattern and the via pattern are mounted.

[0077] 7A and 7B are diagrams illustrating processing using multiple masks according to the first embodiment. FIG. 7A is a top view of a first mask 320. The first mask 320 includes a first trench pattern 322 and a first via pattern 324, which are laser light transmitting regions. The first trench pattern 322 and the first via pattern 324 are examples of a "first mask pattern" in the present disclosure. The first trench pattern 322 includes a first pad portion 326 for forming a pad connected to the trench.

[0078] F7B shows the buildup substrate 200 processed using the first mask 320, and is a cross-sectional view taken along line 7B of F7A. As shown in F7B, the insulating film 204 of the buildup substrate 200 is provided with a first trench processing portion 230 processed by the pulsed laser beam that has passed through the first trench pattern 322, a first via processing portion 232 processed by the pulsed laser beam that has passed through the first via pattern 324, and a first pad processing portion 234 processed by the pulsed laser beam that has passed through the first pad portion 326 of the first trench pattern 322. The first trench processing portion 230, the first via processing portion 232, and the first pad processing portion 234 are each recessed portions formed by removing the insulating film 204 partway through its thickness.

[0079] F7C is a top view of the second mask 330. The second mask 330 includes a second trench pattern 332 and a second via pattern 334, which are laser light transmitting regions. The second trench pattern 332 and the second via pattern 334 are examples of a "second mask pattern" in this disclosure. The second trench pattern 332 includes a second pad portion 336 for forming a pad connected to the trench.

[0080] F7D shows the buildup substrate 200 processed using the second mask 330, and is a cross-sectional view taken along line 7D of F7C. As shown in F7D, the insulating film 204 of the buildup substrate 200 is provided with a second trench processing portion 240 processed by the pulsed laser beam transmitted through the second trench pattern 332, a second via processing portion 242 processed by the pulsed laser beam transmitted through the second via pattern 334, and a second pad processing portion 244 processed by the pulsed laser beam transmitted through the second pad portion 336 of the second trench pattern 332. The second trench processing portion 240, the second via processing portion 242, and the second pad processing portion 244 are recesses formed by removing the insulating film 204 to a depth that is partway along the length of the insulating film 204.

[0081] The first mask 320 and the second mask 330 are configured and positioned so that the second trench processing portion 240 processed through the second trench pattern 332 is positioned adjacent to any of the first trench processing portions 230 processed through the multiple first trench patterns 322.

[0082] The first mask 320 and the second mask 330 are configured and positioned such that the second via pattern 334 is disposed within the first pad portion 326 of the first trench pattern 322. Similarly, the first mask 320 and the second mask 330 are configured and positioned such that the first via pattern 324 is disposed within the second pad portion 336 of the second trench pattern 332.

[0083] The first mask 320 and the second mask 330 may be configured and positioned such that the first pad portion 326 and the second pad portion 336 are disposed adjacent to each other. The first mask 320 and the second mask 330 may be configured and positioned such that the first via pattern 324 and the second via pattern 334 are disposed adjacent to each other.

[0084] 7F7E shows a cross section of the build-up substrate 200 processed using the first mask 320 and the second mask 330. As shown in F7E, a plurality of trenches 250 corresponding to either the first trench processing portion 230 or the second trench processing portion 240 are processed in the insulating film 204 of the build-up substrate 200. The line / space of the plurality of trenches 250 is 2 μm / 2 μm or less.

[0085] Furthermore, a pad 252 corresponding to the first pad processing portion 234 is formed in the insulating film 204 of the buildup substrate 200, and a via 254 corresponding to the second via processing portion 242 is formed inside the pad 252. Similarly, a pad 256 corresponding to the second pad processing portion 244 is formed in the insulating film 204 of the buildup substrate 200, and a via 258 corresponding to the first via processing portion 232 is formed inside the pad 256.

[0086] 3.2 Operation 8 is a flowchart showing steps of the laser processing method according to embodiment 1. The laser processing method is an example of the "laser processing method in which a workpiece is irradiated with laser light output from a laser device via a mask" of the present disclosure.

[0087] In step S11, the user sets the first mask 320 in the laser processing device .

[0088] In step S12, the laser processing processor 100 sets the irradiation conditions to irradiation condition 1. Irradiation condition 1 is a condition under which the insulating film 204 is penetrated only in the portions processed using both the first mask 320 and the second mask 330, and is a condition under which the insulating film 204 is not penetrated when processed using only one of the first mask 320 and the second mask 330. Specifically, irradiation condition 1 is a condition under which the second via processing portion 242 penetrates the insulating film 204 after the pad 252 is formed, and is a condition under which the second trench processing portion 240 does not penetrate the insulating film 204. For example, the laser processing processor 100 sets a condition under which the insulating film 204 is penetrated with twice the number of pulses as in irradiation condition 1.

[0089] In step S13, the laser processing device 14 performs processing by irradiating the surface of the build-up substrate 200 with pulsed laser light through the first mask 320. As a result, a first trench processing portion 230, a first via processing portion 232, and a first pad processing portion 234 are formed in the insulating film 204 of the build-up substrate 200.

[0090] In step S14, the user sets the second mask 330 in the laser processing apparatus 14. The second trench processing portion 240 processed through the second trench pattern 332 of the second mask 330 is positioned adjacent to the first trench processing portion 230 in the insulating film 204 of the build-up substrate 200. The second via processing portion 242 processed through the second via pattern 334 of the second mask 330 is positioned to be located inside the first pad processing portion 234. The second pad portion 336 of the second trench pattern 332 of the second mask 330 is positioned to include the first via processing portion 232 in the insulating film 204 of the build-up substrate 200.

[0091] In step S15, the laser processing processor 100 sets the irradiation conditions to irradiation conditions 1. Since the irradiation conditions 1 set in step S15 are the same as the irradiation conditions 1 set in step S12, the processing of step S15 may be omitted.

[0092] In step S16, the laser processing apparatus 14 irradiates the surface of the buildup substrate 200 with pulsed laser light through the second mask 330 to perform processing. As a result, a second trench processing portion 240, a second via processing portion 242, and a second pad processing portion 244 are formed in the insulating film 204 of the buildup substrate 200, in which the first trench processing portion 230, the first via processing portion 232, and the first pad processing portion 234 have been formed. As a result, a trench 250, pads 252 and 256, and vias 254 and 258 are formed in the insulating film 204 of the buildup substrate 200. This completes the processing of the flowchart.

[0093] In this way, trenches 250 are formed in the insulating film 204 of the build-up substrate 200 at positions corresponding to the first trench pattern 322 and the second trench pattern 332, pads 252 and 256 are formed at positions corresponding to the first pad portion 326 of the first trench pattern 322 and the second pad portion 336 of the second trench pattern 332, and vias 254 and 258 are formed at positions corresponding to the first via pattern 324 and the second via pattern 334, respectively.

[0094] Here, processing using the first mask 320 is performed followed by processing using the second mask 330, but processing using the second mask 330 may be performed followed by processing using the first mask 320.

[0095] 3.3 Actions and Effects According to the first embodiment, by using a mask that includes both a trench pattern and a via pattern, it is possible to process trenches that do not penetrate an insulating film and to process vias that penetrate the insulating film without increasing the number of masks.

[0096] Furthermore, according to the first embodiment, double patterning is performed, which makes it possible to suppress the shoulder droop of the trench and to achieve finer line and space patterns.

[0097] 3.4 Variations 3.4.1 Configuration and operation The processing method of embodiment 1 may be performed using multiple processing devices. FIG. 9 is a flowchart showing steps of a processing method according to a modified example of embodiment 1. Here, an example using a first laser processing system (not shown) and a second laser processing system (not shown) will be described. The first laser processing system and the second laser processing system each have the same configuration as the laser processing system 10 and include a first laser processing device and a second laser processing device, respectively. At the start of the flowchart, a first mask 320 is set in the first laser processing device, and a second mask 330 is set in the second laser processing device.

[0098] In step S21, the user sets the build-up substrate 200 as the workpiece 160 in the first laser processing device.

[0099] In step S22, the laser processing processor of the first laser processing device sets the irradiation conditions to irradiation conditions 1.

[0100] In step S23, the first laser processing device performs processing by irradiating the surface of the build-up substrate 200 with pulsed laser light through the first mask 320. As a result, a first trench processing portion 230, a first via processing portion 232, and a first pad processing portion 234 are formed in the insulating film 204 of the build-up substrate 200.

[0101] In step S24, the user moves the buildup substrate 200 from the first laser processing device to the second laser processing device. The movement of the buildup substrate 200 may be performed by a robot or the like (not shown).

[0102] In step S25, the user sets the buildup substrate 200 in the second laser processing device.

[0103] In step S26, the laser processing processor of the second laser processing device sets the irradiation conditions to irradiation conditions 2. Irradiation conditions 2 may be the same as irradiation conditions 1, or different parameters may be set for irradiation conditions 1. For example, irradiation conditions 2 may be set for the second laser processing device so that processing to the same depth as processing by the first laser processing device can be performed.

[0104] In step S27, the second laser processing device irradiates the surface of the buildup substrate 200 with pulsed laser light through the second mask 330 to perform processing. As a result, a second trench processing portion 240, a second via processing portion 242, and a second pad processing portion 244 are formed in the insulating film 204 of the buildup substrate 200, in which the first trench processing portion 230, the first via processing portion 232, and the first pad processing portion 234 have been formed. As a result, a trench 250, pads 252 and 256, and vias 254 and 258 are formed in the insulating film 204 of the buildup substrate 200. This completes the processing of the flowchart.

[0105] 3.4.2 Actions and Effects According to the processing method of the modified example of the first embodiment, the mask does not need to be repositioned in the processing apparatus, and therefore the number of steps for positioning the mask can be reduced.

[0106] 4. Embodiment 2 In the first embodiment, an example was described in which a through-via is formed by processing the overlapping portion of two mask patterns twice under the same irradiation conditions. However, due to variations in the deposition of the insulating film and the processing conditions of the laser processing system, processing may occur in which the number of irradiation pulses is relatively small compared to the film thickness. In such cases, vias that do not penetrate the insulating film may be generated, which may result in a decrease in yield. Therefore, it is recommended to deposit a thick insulating film in advance and increase the number of irradiation pulses for each mask. In other words, the influence of variations can be reduced by reducing the contribution of one pulse to processing.

[0107] 4.1 Configuration In the build-up substrate 200A according to the second embodiment, the insulating film 204A is formed to have a relatively large thickness in advance. The thickness of the insulating film 204A is, for example, 1.1 times or more the thickness in a case not according to the second embodiment, and may be 1.1 times or more the thickness required for an electronic device.

[0108] The configuration of the laser processing system 10 is the same as that of embodiment 1. The number of pulses in the irradiation conditions of the laser processing device 14 is set to be 1.1 times or more greater than the number of pulses required to penetrate the insulating film 204A, which is formed relatively thick.

[0109] 4.2 Operation The operation of the laser processing device 14 is basically the same as in the first embodiment, but the total number of pulses for the two times is set to be greater than the number of penetration pulses for the film thickness.

[0110] For example, the insulating film 204A is formed to a thickness of 15 μmt, which is 1.1 times thicker than the final thickness of 10 μmt. Here, 10 μmt refers to a thickness or depth of 10 micrometers. If the processing rate is 1 μm / pulse, the number of pulses required to penetrate the insulating film 204A is 15. Furthermore, the number of pulses required to process each of the first mask 320 and the second mask 330 of the laser processing device 14 is set to 10 pulses (10 μm processing). The total number of pulses (20 pulses) for the two processes is 1.1 times greater than the 15 pulses required to penetrate the insulating film 204A, resulting in a processing depth of 20 μmt, thereby reducing the possibility of incomplete penetration. In this way, the insulating film 204A is penetrated by 20 μm by irradiating the 15 μmt insulating film 204A with a total of 20 pulses.

[0111] The extra film portion on the upper surface of the insulating film 204A, which has been formed relatively thick in advance, is removed by CMP (Chemical Mechanical Polishing) after forming the wiring layer by plating.

[0112] Fig. 10 is a diagram for explaining a processing method according to embodiment 2. In a buildup substrate 200A shown in Fig. 10, an insulating film 204A is laminated on the upper surface of a substrate 202. The thickness of the insulating film 204A is 1.1 times or more the thickness of the insulating film 204 of the buildup substrate 200 of embodiment 1, and is, for example, 15 µmt.

[0113] 10 shows a buildup substrate 200A processed using a first mask 320. A first trench processing portion 230, a first via processing portion 232, and a first pad processing portion 234 are processed in an insulating film 204A of the buildup substrate 200A shown in F10A. The first trench processing portion 230, the first via processing portion 232, and the first pad processing portion 234 are each processed to a depth of 10 μm in the thickness direction of the insulating film 204A.

[0114] F10B in Fig. 10 shows a buildup substrate 200A processed using a second mask 330. A second trench processing portion 240, a second via processing portion 242, and a second pad processing portion 244 are processed in an insulating film 204A of the buildup substrate 200A shown in F10B. The second trench processing portion 240, the second via processing portion 242, and the second pad processing portion 244 are each processed to a depth of 10 µm in the thickness direction of the insulating film 204A.

[0115] F10C in Fig. 10 shows a cross section of the buildup substrate 200A processed using the first mask 320 and the second mask 330. As shown in F10C, a trench 250, pads 252 and 256, and vias 254 and 258 are processed in the insulating film 204A of the buildup substrate 200A. The vias 254 and 258 are irradiated with pulsed laser light both in the processing using the first mask 320 and in the processing using the second mask 330, and therefore, are irradiated with pulsed laser light under conditions that allow processing to a depth of 20 µm. Therefore, the vias 254 and 258 reliably penetrate the insulating film 204A.

[0116] 10F10D shows a state in which an excess portion 270 on the upper surface of the insulating film 204A has been removed after the wiring layer 260 has been formed in the trench 250, the pads 252 and 256, and the vias 254 and 258. The excess portion 270 is, for example, a portion 5 μm in the film thickness direction from the upper surface of the insulating film 204A. By removing the excess portion 270, the film thickness of the insulating film 204A becomes the same as that of the insulating film 204 of the build-up substrate 200 of the first embodiment.

[0117] 4.3 Actions and Effects According to the second embodiment, the occurrence of non-through vias can be prevented, and therefore a decrease in yield can be suppressed.

[0118] 5. Embodiment 3 5.1 Configuration 11 is a diagram showing the configuration of a laser processing system 10A according to embodiment 3. The laser device 12 of the laser processing system 10A may be an excimer laser device, a solid-state laser device that outputs ultraviolet pulsed laser light, or a device including a solid-state laser device and an excimer amplifier. The same applies to the laser device 12 according to embodiment 1 and embodiment 2.

[0119] 11, the laser processing apparatus 14 of the laser processing system 10A includes a mask moving mechanism 138. The mask moving mechanism 138 is connected to the laser processing processor 100.

[0120] FIG. 12 is a plan view of the mask moving mechanism 138. The mask moving mechanism 138 includes a frame 139. The frame 139 is a mask mounting member on which the first mask 320 and the second mask 330 are mounted. The mask moving mechanism 138 can selectively position either the first mask 320 or the second mask 330 in a laser light irradiation area 400 by moving the frame 139. The laser light irradiation area 400 is an example of the "laser light irradiation position" in this disclosure, and corresponds to the rectangular area of ​​the irradiation beam shown in FIG. 2. In the example shown in FIG. 12, the mask moving mechanism 138 is configured to be able to slide the frame 139, on which the first mask 320 and the second mask 330 are mounted, in the X direction and the -X direction within the XY plane.

[0121] 12, the mask moving mechanism 138 may be configured to rotate the first mask 320 and the second mask 330 by rotating a disk serving as a mask mounting member on which the first mask 320 and the second mask 330 are mounted in the XY plane around an axis parallel to the Z direction, thereby enabling the first mask 320 and the second mask 330 to be rotatably moved, and to selectively place either the first mask 320 or the second mask 330 in the laser light irradiation region 400. The first mask 320 and the second mask 330 may be formed on the same mask substrate.

[0122] 5.2 Operation The laser processing processor 100 positions the first mask 320 in the laser light irradiation region 400 using the mask moving mechanism 138, and performs processing under irradiation condition 1.

[0123] Next, the laser processing processor 100 positions the second mask 330 in the laser light irradiation area 400 using the mask moving mechanism 138, and performs processing under irradiation condition 2. The irradiation condition 2 may be the same as the irradiation condition 1, or different parameters may be set for the irradiation condition 1. For example, the irradiation condition 2 may be set so that processing to the same depth as processing using the first mask 320 can be performed.

[0124] 5.3 Actions and Effects By automatically replacing the first mask 320 and the second mask 330, the number of steps required for mask replacement can be reduced.

[0125] 6. Manufacturing method of electronic devices After trenches, pads, and vias are formed in the workpiece 160 by the laser processing methods according to the first to third embodiments, electronic devices can be manufactured through a number of steps.

[0126] The workpiece 160 may be an interposer substrate that relays between a semiconductor integrated circuit and a substrate. The interposer substrate is processed using the laser processing methods according to the first to third embodiments to produce an interposer. The interposer and a semiconductor integrated circuit (not shown) are bonded together to electrically connect them to each other. The interposer and a circuit board (not shown) are bonded together to electrically connect them to each other. This makes it possible to manufacture an electronic device in which the semiconductor integrated circuit and the circuit board are electrically connected by the interposer.

[0127] 7.Other The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments can be used in combination.

[0128] Terms used throughout this specification and claims should be construed as "open ended" unless expressly stated otherwise. For example, terms such as "comprise," "have," "comprise," and "equip" should be construed as meaning "without excluding the presence of elements other than those listed." In addition, the modifier "a" should be construed as meaning "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." Furthermore, it should be construed as including combinations of these with elements other than "A," "B," and "C."

Claims

1. A laser processing method in which a laser beam output from a laser device is irradiated onto a workpiece through a mask, comprising: the workpiece includes a substrate and an insulating film formed on the substrate; The irradiation through the mask comprises: irradiating the workpiece with the laser light through a first mask pattern in which a first trench pattern including a first pad portion and a first via pattern are formed; irradiating the workpiece with the laser light through a second mask pattern in which a second trench pattern and a second via pattern are formed; Including, irradiating the workpiece with the laser light through the second mask pattern includes: Positioning a second trench processing portion to be processed through the second trench pattern adjacent to the first trench processing portion of the workpiece processed through the first trench pattern; Positioning a second via processing portion to be processed through the second via pattern within the first pad processing portion of the workpiece processed through the first pad portion; A laser processing method comprising:

2. The laser processing method according to claim 1, setting irradiation conditions for the laser device; the irradiation conditions of the laser light through the first mask pattern and the irradiation conditions of the laser light through the second mask pattern are the same; Laser processing method.

3. The laser processing method according to claim 2, The irradiation conditions include at least one of a fluence, a pulse number, and a repetition frequency of the laser light. Laser processing method.

4. The laser processing method according to claim 3, the irradiation conditions are conditions under which the second via processing portion penetrates the insulating film when the laser light is irradiated through the second mask pattern, and conditions under which the second trench processing portion does not penetrate the insulating film. Laser processing method.

5. The laser processing method according to claim 1, the second trench pattern of the second mask pattern includes a second pad portion; a second pad processing portion processed through the second pad portion is positioned to include a first via processing portion of the workpiece processed through the first via pattern; Laser processing method.

6. The laser processing method according to claim 5, the second pad processing portion is positioned adjacent to the first pad processing portion, The second via processing portion is positioned adjacent to the first via processing portion. Laser processing method.

7. The laser processing method according to claim 1, the laser light is an excimer laser light; Laser processing method.

8. The laser processing method according to claim 2, The insulating film is formed to a thickness that is 1.1 times or more the required thickness, the irradiation conditions include setting a pulse number that is 1.1 times or more greater than the pulse number that can penetrate the insulating film; Laser processing method.

9. The laser processing method according to claim 8, removing the insulating film by CMP; Laser processing method.

10. The laser processing method according to claim 9, forming a wiring layer by plating on the processed portion of the workpiece by the first mask pattern and the second mask pattern before removing the insulating film by the CMP. Laser processing method.

11. The laser processing method according to claim 1, the irradiating of the laser light onto the workpiece via the first mask pattern is performed by a first laser processing apparatus; The irradiating of the workpiece with the laser light via the second mask pattern is performed by a second laser processing apparatus different from the first laser processing apparatus. Laser processing method.

12. The laser processing method according to claim 11, moving the workpiece from the first laser processing device to the second laser processing device by a robot; A laser processing method comprising:

13. The laser processing method according to claim 1, The line / space in the plurality of trenches in which the first trench processing portion and the second trench processing portion are adjacent to each other is 2 μm / 2 μm or less. Laser processing method.

14. 1. A method for manufacturing an electronic device, comprising irradiating a workpiece with laser light output from a laser apparatus through a mask in order to manufacture the electronic device, the method comprising: the workpiece includes a substrate and an insulating film formed on the substrate; The irradiation through the mask comprises: irradiating the workpiece with the laser light through a first mask pattern in which a first trench pattern including a first pad portion and a first via pattern are formed; irradiating the workpiece with the laser light through a second mask pattern in which a second trench pattern and a second via pattern are formed; Including, irradiating the workpiece with the laser light through the second mask pattern includes: positioning a second trench processing portion to be processed through the second trench pattern adjacent to the first trench processing portion of the workpiece processed through the first trench pattern; Positioning a second via processing portion to be processed through the second via pattern within the first pad processing portion of the workpiece processed through the first pad portion; A method for manufacturing an electronic device, comprising:

15. 15. The method for manufacturing an electronic device according to claim 14, comprising: the workpiece is an interposer substrate, fabricating an interposer by processing the interposer substrate by irradiating the laser light; coupling the interposer and a semiconductor integrated circuit to electrically connect them to each other; coupling the interposer and a circuit board to electrically connect them together; A method for manufacturing an electronic device, comprising:

16. A laser processing apparatus that irradiates a workpiece with laser light output from a laser device through a mask, a mask mounting member on which the first mask and the second mask are mounted; a mask moving mechanism that moves one of the first mask and the second mask placed on the mask placement member to a position where the laser light is irradiated; a processor; Equipped with The processor: moving the first mask to a position where the laser light is to be irradiated; and irradiating the workpiece with the laser light through a first trench pattern and a first via pattern, the first trench pattern and the first via pattern including a first pad portion formed on the first mask; moving the second mask to a position where the laser light is to be irradiated, and irradiating the workpiece with the laser light through a second trench pattern and a second via pattern formed on the second mask; Irradiating the workpiece with the laser light through the second trench pattern and the second via pattern includes: Positioning a second trench processing portion to be processed through the second trench pattern adjacent to the first trench processing portion of the workpiece processed through the first trench pattern; Positioning a second via processing portion to be processed through the second via pattern within the first pad processing portion of the workpiece processed through the first pad portion; A laser processing device comprising:

17. The laser processing apparatus according to claim 16, the mask moving mechanism slides or rotates the first mask and the second mask placed on the mask placement member; Laser processing equipment.

18. The laser processing apparatus according to claim 17, the first mask and the second mask are formed on the same mask substrate; Laser processing equipment.

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