Ablation processing apparatus and processing method

Abstract

To provide a processing device which prevents light having high energy density from being continuously radiated to one point of a projection optical system and hardly causes deterioration of an element, when ablation processing is performed using the light.SOLUTION: A processing device 100 for ablation processing includes: a line beam formation part 20 having a line beam formation optical system 25 for shaping a laser beam emitted from a laser 10 into a line shape, and a casing 20K storing the line beam formation optical system 25; a projection optical system 30 which is installed in a device body, and projects a substrate arranged in the device body with the light that is guided to a mask M arranged in the device body from the line beam formation part 20 and transmits through the mask M; and a scanning mechanism 60 which relatively moves the line beam formation part 20 to the device body and scans the device body with line-shaped light. The scanning mechanism 60 faces the casing 20K of the line beam formation part 20 in the scanning direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a processing apparatus used for ablation processing of a substrate or the like using high-energy density light such as laser light to form a pattern. [Background technology]

[0002] As electronic devices become smaller and more densely packed, high-precision pattern formation is required for printed wiring boards, etc. For example, multilayer boards require the formation of microscopic vias and trenches on the order of μm.

[0003] Ablation processing is known as a method for microfabrication. In this method, a high-energy density laser such as an excimer laser is irradiated onto a mask and projected onto a substrate or the like. By instantaneously removing the material surface in accordance with the mask pattern, vias and wiring grooves can be formed on the substrate or the like (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-147242 A [Patent Document 2] JP 2001-79678 A Summary of the Invention [Problem to be solved by the invention]

[0005] In order to cause the ablation phenomenon, it is necessary to increase the energy density (fluency) on the substrate surface. However, the use of light with high energy density is limited because the optical elements of the projection optical system are prone to degradation (such as crack generation and reduced transmittance or reflectance).

[0006] Therefore, it is necessary to provide a processing device that can utilize sufficient high density energy. [Means for solving the problem]

[0007] One aspect of the present invention is a processing apparatus for ablation processing, which comprises a line beam forming unit having a line beam forming optical system that shapes laser light emitted from a laser light source into a line shape and a casing that houses the line beam forming optical system, a projection optical system installed in the apparatus body that is guided from the line beam forming unit to a mask arranged in the apparatus body and projects the light that has passed through the mask onto a substrate arranged in the apparatus body, and a scanning mechanism that moves the line beam forming unit relative to the apparatus body to scan the line-shaped light, and the scanning mechanism faces the casing of the line beam forming unit along the scanning direction.

[0008] For example, the scanning mechanism is located below a casing of the line beam forming unit in the up-down direction of the apparatus body. For example, the scanning mechanism is disposed outside the space above a mask stage that supports a mask.

[0009] For example, the scanning mechanism may be configured such that the optical axis of the line beam forming optical system is aligned along the scanning direction, and may relatively move the line beam forming unit while maintaining the position of the optical axis of the line beam forming optical system.

[0010] The processing apparatus may further include a shutter mechanism that is disposed on the optical path between the mask and the line beam forming optical system and that is capable of changing the width of the line-shaped light. For example, the alignment camera for the mask is installed on the casing of the line beam forming unit.

[0011] The processing device may further include a detection unit that detects the optical axis direction of light incident on the line beam forming optical system from the laser light source, a correction optical system that can adjust the optical axis of the light incident on the line beam forming optical system from the laser light source, and a drive mechanism that drives the correction optical system so as to compensate for the deviation in the optical axis direction based on the output from the detection unit. For example, the correction optical system is provided on the optical path between the laser light source and the line beam forming optical system.

[0012] Another aspect of the present invention is a processing method for an ablation processing device, in which a line beam forming optical system housed in a casing of a line beam forming unit shapes light emitted from a laser light source into a line, guides the line-shaped light to an ablation processing mask arranged in the main body of the ablation processing device, projects the light that has passed through the mask onto a substrate arranged in the main body by a projection optical system installed in the main body, and moves the casing of the line beam forming unit relative to the main body of the device by a scanning mechanism to scan the line-shaped light, wherein the line beam forming optical system is housed in the casing of the line beam forming unit so that the optical axis of the line beam forming optical system is parallel to the scanning direction, and the scanning mechanism is arranged to face the casing of the line beam forming optical system along the scanning direction.

[0013] For example, a processing apparatus for ablation processing which is one embodiment of the present invention includes a line beam forming optical system which shapes light emitted from a laser into a line shape and guides it to a mask for ablation processing which is arranged in the main body of the apparatus, a projection optical system which is installed in the main body of the apparatus and projects the light which has passed through the mask onto a substrate which is arranged in the main body of the apparatus, and a scanning mechanism which moves a line beam forming unit which contains the line beam forming optical system relative to the main body of the apparatus and scans the line-shaped light.

[0014] The line beam forming unit can be disposed in the apparatus body so that the optical axis of the line beam forming optical system is parallel to the scanning direction. For example, the line beam forming unit can include a case or housing that contains the line beam forming optical system, and the apparatus body can support the line beam forming unit above the mask by a support member such as a stand. The line beam forming unit moves relative to the apparatus body along the scanning direction, so that the line-shaped light can be scanned over the mask, the projection optical system, and the substrate. The laser can be installed either inside or outside the processing apparatus.

[0015] The scanning mechanism can be disposed below the line beam forming unit and outside the space above the mask stage that supports the mask, that is, at a location that does not enter the space above. For example, the scanning mechanism can be disposed so as to face the line beam forming unit along the scanning direction.

[0016] The processing device is disposed on the optical path between the mask and the line beam forming optical system, and can be provided with a shutter mechanism capable of changing the width of the line-shaped light. Also, an alignment camera for the mask can be installed on the casing of the line beam forming unit.

[0017] The processing device may also include a detection unit that detects the direction of the optical axis of light incident on the line beam forming optical system from the laser light source, a correction optical system that can adjust the optical axis of light incident on the line beam forming optical system from the laser light source, and a drive mechanism that drives the correction optical system so as to compensate for the deviation in the optical axis direction based on the output from the detection unit. For example, the correction optical system is provided on the optical path between the laser light source and the line beam forming optical system, and can fold the optical path between the laser light source and the line beam forming optical system along the vertical direction of the device body.

[0018] For example, in a processing method using an ablation processing apparatus which is another aspect of the present invention, a line beam forming optical system shapes light emitted from a laser light source into a line shape and guides it to an ablation processing mask arranged in the main body of the ablation processing apparatus, a projection optical system installed in the main body projects the light that has passed through the mask onto a substrate arranged in the main body, and a scanning mechanism moves a line beam forming section which contains the line beam forming optical system relative to the main body of the apparatus to scan the line-shaped light. Effect of the Invention

[0019] According to the present invention, it is possible to provide a processing apparatus in which, when ablation processing is performed using light with high energy density, light does not continuously impinge on one point of the projection optical system, and deterioration of elements is less likely to occur. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic configuration diagram of a processing device according to an embodiment of the present invention, as viewed from the side; [Diagram 2] FIG. 2 is a schematic block diagram of a processing device. [Diagram 3] FIG. 13 is a diagram showing a modified example of the processing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] Fig. 1 is a schematic configuration diagram of the processing device according to the present embodiment as viewed from the side. Fig. 2 is a schematic block diagram of the processing device. Note that Fig. 1 illustrates some of the components of the processing device.

[0023] The processing apparatus 100 is a processing apparatus capable of forming a pattern on a substrate (workpiece) W by ablation processing, and includes a laser 10, a line beam forming unit 20, a projection optical system 30, a mask stage 40, and a processing stage 50. The line beam forming unit 20, the projection optical system 30, the mask stage 40, and the processing stage 50 are mounted on an apparatus body 15, and the mask M and the substrate W are placed on the mask stage 40 and the processing stage 50, respectively (see FIG. 2). Here, the substrate W is constituted by a resin substrate such as a printed circuit board.

[0024] The laser 10 oscillates high energy density laser light from a laser light source 10S. In this embodiment, an excimer laser that irradiates pulses of KrF excimer laser light with a wavelength of 248 nm is used. The laser light emitted from the laser light source 10S is guided to the line beam forming unit 20 by a correction optical system 70.

[0025] More specifically, the laser light emitted from the laser light source 10S is reflected by the correction optical system 70A disposed below, and travels horizontally to the other correction optical system 70B disposed at the same height. The laser light reflected by the correction optical system 70B travels upward, and enters the line beam forming unit 20 via the mirror 29A.

[0026] The correction optical system 70 is capable of adjusting the optical axis of the laser light incident on the line beam forming unit 20. The drive mechanism 90 drives the correction optical system 70 to adjust the position (posture) of the correction optical system 70. A detection unit (photo sensor) 95 that detects the optical axis direction of the laser light is provided near the light entrance of the line beam forming unit 20 and near the laser light source 10S. Note that the detection unit 95 can also be a CCD camera, a line sensor, or the like.

[0027] The line beam forming unit 20 has a line beam forming optical system 25 including a cylindrical lens and the like, and shapes the beam of laser light incident along the scanning direction into a line-shaped beam. The line-shaped light is guided to the mask M via a mirror 29B. For example, the laser light is shaped into light having a length of 300 mm in the longitudinal direction and a width of 100 μm or less.

[0028] The line beam forming unit 20 accommodates the line beam forming optical system 25 in its casing 20K, and is held by the stand 27 so as to be located above the mask stage 40. The line beam forming unit 20 is also installed so that the optical axis of the line beam forming optical system 25 is parallel to the scanning direction. The scanning mechanism 60 supporting the stand 27 is located at approximately the same height as the mask stage 40, and is disposed adjacent to the mask stage 40 along the scanning direction X. The scanning mechanism 60 is installed on the same support stand 15S as the mask stage 40. The scanning mechanism 60 can move the line beam forming unit 20 back and forth along the scanning direction (X direction). As the line beam forming unit 20 moves, a line-shaped light perpendicular to the scanning direction (X direction) moves relative to the mask M and the projection optical system 30, and the mask M and the substrate W fixed to the mask stage 40 and the processing stage 50, respectively, are scanned.

[0029] The mask stage 40 holds the mask M and can position the mask M by moving it in the XY directions and rotating it. An alignment camera 91 that captures an image of an alignment mark provided on the mask M is installed on the surface (here, the side surface) of the casing 20K of the line beam forming unit 20 (not shown in FIG. 3).

[0030] A shutter mechanism 93 is provided above the mask stage 40. The shutter mechanism 93 is disposed between the line beam forming unit 20 and the mask M, and is capable of changing the size of the exposure area of ​​the mask M by adjusting the width (length in the Y direction) of the line-shaped light.

[0031] The projection optical system 30 is a projection optical system having a focal point on the surface of the mask M and the surface of the substrate W, and projects the light transmitted through the mask M onto the substrate W. Here, the projection optical system 30 is configured as a reduction projection optical system (for example, a magnification of 1 / 4).

[0032] The processing stage 50 fixes the substrate W by vacuum suction or the like, and can position the substrate W with respect to the mask M by moving in the XY directions and rotating. The processing stage 50 can also move in steps along the scanning direction (here, the X direction) so that ablation processing can be performed over the entire substrate W. An alignment camera (not shown) is installed beside the processing stage 50 to capture an image of an alignment mark provided on the substrate W.

[0033] The mask M has a mask pattern drawn on a base material (e.g., quartz glass) that transmits the KrF excimer laser light, by forming a light-shielding film (e.g., an Al film) that blocks the KrF excimer laser light. A pattern that appears repeatedly on the substrate W may be drawn on the mask M, or a pattern that covers the entire substrate W may be drawn on the mask M.

[0034] As described above, the substrate W here is a resin substrate, with a copper wiring layer formed on a base material such as epoxy resin, and an insulating layer formed thereon. By irradiating the substrate W with high-energy density excimer laser light from the excimer laser 10, ablation occurs on the substrate W, and a pattern corresponding to the mask pattern (hereinafter referred to as a processed pattern) is formed.

[0035] The processing pattern can be a through via, a non-through via, a groove (trenches) for a wiring pattern, etc. After the processing pattern is formed on the substrate W by the ablation process, a conductor such as copper is filled in.

[0036] 2 controls the operation of the processing device 100. When an operator performs an input operation for performing ablation processing, the controller 80 drives the laser 10, drives and controls the scanning mechanism 60 to scan a line of light in the X direction, and drives the driving mechanism 90 to adjust the optical axis. The controller 80 also controls the movement of the mask stage 40 and the processing stage 50, adjusts the optical axis deviation based on an output signal from the detection unit 95, and further performs alignment processing by the alignment camera 91, and controls the opening and closing of the shutter mechanism 93.

[0037] A mask pattern corresponding to a processing pattern to be formed on the substrate W is formed on the mask M, and light that has passed through the mask pattern is projected onto the substrate W. A light-shielding portion that defines the area of ​​the mask pattern is formed around the mask pattern.

[0038] The ablation process is performed while moving the line beam forming unit 20. At this time, the line beam forming unit 20 moves so that the position of the optical axis along the scanning direction of the line beam forming optical system 25 is maintained without deviation. On the other hand, the optical axis of the light incident on the line beam forming unit 20 from the laser 10 may be deviated due to assembly errors or the like. Furthermore, when the substrate W is a multiple substrate, the processing stage 50 is caused to step and repeat, and the line beam forming unit 20 vibrates due to the effect of the movement of the processing stage 50. Therefore, the correction optical system 70 is driven to compensate for the optical axis deviation.

[0039] Thus, according to this embodiment, in the processing apparatus 100 that performs ablation processing, the light from the laser 10 is shaped by the line beam forming optical system 25 into a line-shaped light along a direction perpendicular to the scanning direction X and guided to the mask M, and the line beam forming unit 20 is moved relative to the apparatus body 15 to scan the line-shaped light.

[0040] By scanning the line-shaped light, the fluency on the substrate surface can be increased, and the ablation phenomenon can be caused. In addition, there is no need to continuously irradiate a single point of the projection optical system 30 with high-power laser light, and it is possible to suppress the deterioration of optical characteristics such as transmittance. As a result, it is possible to utilize light with a sufficiently high fluency.

[0041] Furthermore, by moving the line beam forming unit 20 together with the device, the disturbance in shaping of the line-shaped light that occurs when only the optical system is moved is suppressed, and the mask can be scanned with stable high-energy density light. Also, optical scanning can be achieved with a simple scanning mechanism.

[0042] The optical axis of the line beam forming optical system 25 is parallel to the scanning direction, and the position of the optical axis is maintained during movement of the line beam forming unit 20. This makes it easy to project a line of light at an accurate position on the mask M and the substrate W. In addition, since the traveling direction of the light incident on the line beam forming unit 20 is aligned with the scanning direction, disturbance of the optical scanning can be suppressed.

[0043] Scanning mechanism 60, which moves line beam forming unit 20, is installed below line beam forming unit 20 and at the same height as mask stage 40 in apparatus body 15. Since scanning mechanism 60 is not installed above mask stage 40, there is no need to secure space above for arranging the scanning mechanism, and line beam forming optical system 25 and mask M can be arranged as close as possible, enabling highly accurate pattern formation by ablation processing.

[0044] In particular, by arranging the scanning mechanism 60 adjacent to the mask stage 40 along the scanning direction X, it becomes possible to arrange the line beam forming unit 20 directly above, and the moving direction of the line beam forming unit 20 can be stably guided. Note that some member, device, etc. may be arranged in the line beam forming unit 20 and the scanning mechanism 60. In addition, it does not have to be installed on the same table as the mask stage 40, and it is sufficient to arrange it below the line beam forming unit 20 and outside the space SP (see FIG. 2) above the mask stage 40.

[0045] Moreover, optical axis adjustment can be easily performed by providing the correction optical system 70 outside the line beam forming unit 20. In particular, by forming an optical path in which the laser light travels downward and then upward, i.e., a return optical path, it is easy to arrange the correction optical system 70 in the optical path, and it becomes possible to arrange the device body 15 and the laser 10 in close proximity to each other.

[0046] Furthermore, by providing a shutter mechanism 93, it is possible to form patterns in various processing regions (chip regions). Also, by installing the alignment camera 91 in the casing 20K of the line beam forming unit 20, it is not necessary to provide a movement mechanism dedicated to the alignment camera 91, and alignment can be performed without interfering with the movement of the line beam forming unit 20.

[0047] 6 is a diagram showing a modified example of the above-mentioned processing apparatus. A shutter mechanism 93' is provided in the line beam forming unit 20, and is disposed on the optical path between the mirror 29B and the mask stage 40. An alignment camera 91' is installed at a position adjacent to the mask stage 40.

[0048] Since the shutter mechanism 93' is provided in the line beam forming unit 20, the shutter mechanism 93' does not interfere with the driving range of the scanning mechanism 60, and it is possible to make the distance between the mask stage 40 and the lower side of the line beam forming unit 20 closer.

[0049] The laser 10 may be configured to be installed outside the processing apparatus 100. The line beam forming unit 20 may be configured to accommodate other optical systems (such as an illumination optical system). The above-described processing apparatus is also effective for a mask on which no light-shielding pattern is formed. [Explanation of symbols]

[0050] 10. Laser 15. Device body 20 Line beam forming section 25 Line beam forming optics 30 Projection optical system 100 Processing equipment M Mask W substrate

Claims

1. a line beam forming unit including a line beam forming optical system that shapes a laser beam emitted from a laser light source into a line shape and a casing that houses the line beam forming optical system; a projection optical system installed in an apparatus body, the projection optical system being configured to guide light from the line beam forming unit to a mask disposed in the apparatus body and project light transmitted through the mask onto a substrate disposed in the apparatus body; a scanning mechanism for moving the line beam forming unit relative to the device body and scanning a line-shaped light, A processing device for ablation processing, characterized in that the scanning mechanism faces a casing of the line beam forming unit along a scanning direction.

2. 2. The processing apparatus according to claim 1, wherein the scanning mechanism is located below a casing of the line beam forming unit.

3. 3. The processing apparatus according to claim 2, wherein the scanning mechanism is disposed outside a space above a mask stage that supports the mask.

4. 2. The processing apparatus according to claim 1, wherein an optical axis of the line beam forming optical system is aligned along a scanning direction.

5. 2. The processing apparatus according to claim 1, wherein the scanning mechanism relatively moves the line beam forming unit while maintaining the optical axis position of the line beam forming optical system.

6. 2. The processing apparatus according to claim 1, further comprising a shutter mechanism arranged on an optical path between the mask and the line beam forming optical system, the shutter mechanism being capable of changing a width of the line-shaped light.

7. 2. The processing apparatus according to claim 1, wherein an alignment camera for the mask is installed in a casing of the line beam forming unit.

8. a detection unit that detects the direction of an optical axis of light incident from the laser light source to the line beam forming optical system; a correction optical system capable of adjusting an optical axis of light incident from the laser light source to the line beam forming optical system; 2. The processing apparatus according to claim 1, further comprising a drive mechanism that drives the correction optical system so as to compensate for deviation in the optical axis direction based on an output from the detection unit.

9. 9. The processing apparatus according to claim 8, wherein the correction optical system is provided on an optical path between the laser light source and the line beam forming optical system.

10. A line beam forming optical system housed in a casing of the line beam forming unit shapes the light emitted from the laser light source into a line shape, and guides the line-shaped light to an ablation processing mask disposed in the main body of the ablation processing device; projecting the light transmitted through the mask onto a substrate disposed in the apparatus body by a projection optical system disposed in the apparatus body; A processing method for an ablation processing device in which a scanning mechanism moves a casing of the line beam forming unit relative to the device body and scans a line-shaped light, The line beam forming optical system is housed in a casing of the line beam forming unit such that an optical axis of the line beam forming optical system is parallel to a scanning direction; A processing method for an ablation processing apparatus, characterized in that the scanning mechanism is disposed so as to face a casing of the line beam forming optical system along a scanning direction.

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