Laser processing apparatus and laser processing method

Abstract

A laser processing apparatus includes a support section, an irradiation section, a moving mechanism, a control section, and an imaging section. The control section performs a first pre-process of irradiating a laser to an object along a processing line having a plurality of parallel lines arranged side by side to form a modified region on the object. The imaging section acquires a first image showing a processing state in which the modified region is formed along the processing line having the plurality of parallel lines by the first pre-process.

Description

[0001] This application is a divisional application of the patent application filed on October 30, 2019, with application number 201980071652.5 and entitled "Laser Processing Apparatus and Laser Processing Method". Technical Field

[0002] One aspect of the present invention relates to a laser processing apparatus and a laser processing method. Background Technology

[0003] Patent Document 1 discloses a laser processing apparatus comprising: a holding mechanism for holding a workpiece, and a laser irradiation mechanism for irradiating the workpiece held by the holding mechanism with a laser. In the laser processing apparatus disclosed in Patent Document 1, the laser irradiation mechanism having a focusing lens is fixed relative to a base, and the movement of the workpiece along a direction perpendicular to the optical axis of the focusing lens is implemented by the holding mechanism.

[0004] [Existing Technical Documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent No. 5456510 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] However, in laser processing apparatuses like those described above, there are cases where a modified region is formed inside the object along an imaginary surface by irradiating the object with a laser. In this case, a portion of the object is peeled off, with the modified region covering the imaginary surface as the boundary. In such peeling processes, under processing conditions such as when irradiating the object with a laser, there is a concern that peeling the object may become difficult.

[0009] Therefore, one aspect of the present invention is to provide a laser processing apparatus and a laser processing method capable of reliably peeling off an object.

[0010] [Technical means to solve the problem]

[0011] According to one aspect of the present invention, a laser processing apparatus forms a modified region along an imaginary surface inside an object by irradiating it with a laser. The laser processing apparatus includes: a support portion supporting the object; an irradiation portion irradiating the object supported by the support portion with a laser; a movement mechanism that moves at least one of the support portion and the irradiation portion in such a way that the position of the laser focusing point moves along the imaginary surface; a control portion controlling the support portion, the irradiation portion, and the movement mechanism; and an imaging portion that captures an image of the object from a direction along the incident direction of the laser. The control portion performs a first preprocessing step in which the laser is irradiated onto the object along a processing line having multiple parallel lines arranged side by side, and a modified region is formed on the object. The imaging portion acquires a first image showing the processing state in which the modified region is formed along the processing line having multiple parallel lines through the first preprocessing step.

[0012] Through repeated and painstaking research, the inventors discovered a correlation between the peeling off of the object and the processing state in which a modified region is formed along a processing line having multiple parallel lines. Therefore, in one aspect of the laser processing apparatus of the present invention, a first image is acquired showing the processing state in which a modified region is formed along a processing line having multiple parallel lines. Based on this first image, processing conditions can be determined in a manner that allows for the peeling off of the object. Thus, the object can be reliably peeled off.

[0013] One aspect of the laser processing apparatus of the present invention may include a control unit performing a second preprocessing step, which involves irradiating a workpiece with a laser along a processing line to form a modified region on the workpiece, and an imaging unit acquiring a second image showing the processing state in which a modified region has been formed along a processing line through the second preprocessing step.

[0014] Through further painstaking research, the inventors discovered a correlation between the peeling off of the object and the processing state in which a modified region is formed along a processing line. Therefore, one aspect of the laser processing apparatus of the present invention acquires a second image showing the processing state in which a modified region is formed along a processing line. Based on this second image, processing conditions can be determined in a manner that allows for the peeling off of the object. Thus, the object can be reliably peeled off.

[0015] In one embodiment of the laser processing apparatus of the present invention, the control unit determines the processing state presented in the second image and changes the processing conditions of the second preprocessing according to the determination result. In this case, the processing conditions of the second preprocessing can be automatically changed according to the second image.

[0016] In one aspect of the laser processing apparatus of the present invention, the control unit determines whether the processing state presented in the second image is a first slicing state. If it is not a first slicing state, the processing conditions of the second pre-processing are changed. The first slicing state is a state in which cracks extending from the plurality of modified points contained in the modified region extend in the direction along a processing line. It has been found that if the processing state in which the modified region is formed along a processing line is not the first slicing state, it makes peeling off the object difficult. Therefore, in one aspect of the present invention, if the processing state presented in the second image is not the first slicing state, the processing conditions of the second pre-processing are changed. In this way, the processing conditions can be determined in a manner that allows for peeling off the object.

[0017] In one embodiment of the laser processing apparatus of the present invention, the control unit determines the processing state presented in the first image and changes the processing conditions of the first preprocessing according to the determination result. In this case, the processing conditions of the first preprocessing can be automatically changed according to the first image.

[0018] One aspect of the laser processing apparatus of the present invention may include: a first pre-processing step in which a laser is irradiated onto a workpiece along a processing line having multiple parallel lines arranged side by side, forming a modified region on the workpiece under a first processing condition; an imaging unit, as a first image, acquires an image showing the processing state after a first predetermined amount of laser processing; and a control unit, based on the first image, determines whether the processing state after the first predetermined amount of laser processing performed in the first pre-processing step is a second cutting state. If it is not a second cutting state, the first processing condition is changed. The second cutting state is a state in which cracks extending from multiple modified points contained in the modified region extend and connect in the direction along the parallel lines and in the direction intersecting the parallel lines.

[0019] It has been discovered that when forming a modified region along a processing line having multiple parallel lines, if laser processing is performed in a manner where the processed state after a first predetermined amount of laser processing becomes the second cutting state, the object can be reliably peeled off. Therefore, in one aspect of the present invention, it is determined based on a first image whether the processed state after the first predetermined amount of laser processing is the second cutting state, and if it is not the second cutting state, the first processing conditions are changed. In this way, the first processing conditions that allow for the reliable peeling off of the object can be determined.

[0020] One aspect of the laser processing apparatus of the present invention includes a first preprocessing step in which a laser is irradiated onto a workpiece along a processing line having multiple parallel lines arranged side by side, forming a modified region on the workpiece under second processing conditions. An imaging unit acquires, as a first image, an image showing a processing state after laser processing with a first predetermined amount, and an image showing a processing state after laser processing with a second predetermined amount, which is more than the first predetermined amount. A control unit determines, based on the first image showing the processing state after laser processing with the first predetermined amount, whether the processing state after laser processing with the first predetermined amount performed in the first preprocessing step is a second cutting state. When the first predetermined amount... If the processing state after laser processing is the second cutting state, the second processing conditions are changed. If the processing state after laser processing of the first specified amount is not the second cutting state, the processing state after laser processing of the second specified amount is determined based on the first image, which is an image showing the processing state after laser processing of the second specified amount. If the processing state after laser processing of the second specified amount is not the second cutting state, the second processing conditions are changed. The second cutting state is a state in which cracks extending from multiple modified points contained in the modified region extend and connect in the direction along parallel lines and in the direction intersecting with parallel lines.

[0021] It has been found that when forming a modified region along a processing line having multiple parallel lines, if laser processing is performed in a manner where the processed state after a second predetermined amount of laser processing becomes the second cutting state, the increase in production time can be suppressed, and the object can be peeled off. Therefore, in one aspect of the present invention, it is determined based on a first image whether the processed state after a first predetermined amount of laser processing is the second cutting state; if it is the second cutting state, the second processing conditions are changed. It is also determined based on a first image whether the processed state after a second predetermined amount of laser processing is the second cutting state; if it is not the second cutting state, the second processing conditions are changed. In this way, a second processing condition that suppresses the increase in production time and peels off the object can be determined.

[0022] One aspect of the laser processing apparatus of the present invention can be a wafer for determining conditions or a wafer for semiconductor devices. When the wafer is a wafer for determining conditions, processing lines can be set at any point across the entire wafer area to determine the processing conditions. When the wafer is a wafer for semiconductor devices, processing lines can be set at the outer edge region of the wafer where they have less impact on the peeling quality to determine the processing conditions. A wafer for determining conditions is, for example, a wafer used for operation (practice) that will not ultimately become a semiconductor device (product). A wafer used for semiconductor devices is, for example, a wafer used for production (manufacturing) that will ultimately become a semiconductor device.

[0023] One aspect of the laser processing method of the present invention involves irradiating an object with a laser to form a modified region along an imaginary surface inside the object. The laser processing method includes a first pre-processing step and a first imaging step. The first pre-processing step involves irradiating the object with a laser along a processing line having multiple parallel lines arranged side by side to form a modified region on the object. The first imaging step involves acquiring a first image, which shows the processing state in which the modified region has been formed along the processing line having multiple parallel lines through the first pre-processing step.

[0024] In this laser processing method, a first image is obtained, which shows the processing state in which a modified region has been formed along a processing line having multiple parallel lines by a first preceding process. Based on the obtained first image, processing conditions can be determined in a manner that allows the object to be peeled off. Therefore, the object can be reliably peeled off.

[0025] [The effects of the invention]

[0026] According to one aspect of the present invention, a laser processing apparatus and a laser processing method are provided that can reliably peel off an object. Attached Figure Description

[0027] [ Figure 1 [This is a perspective view of the laser processing apparatus according to the embodiment.]

[0028] [ Figure 2 ]for Figure 1 A front view of a portion of the laser processing apparatus shown.

[0029] [ Figure 3 ]for Figure 1 The front view of the laser processing head of the laser processing device shown.

[0030] [ Figure 4 ]for Figure 3 The image shows a side view of the laser processing head.

[0031] [ Figure 5 ]for Figure 3 The diagram shows the structure of the optical system of the laser processing head.

[0032] [ Figure 6 [This is a structural diagram of the optical system of a modified laser processing head.]

[0033] [ Figure 7 [This is a front view of a portion of a modified laser processing apparatus.]

[0034] [ Figure 8 [This is a three-dimensional view of a modified laser processing apparatus.]

[0035] [ Figure 9This is a top view showing the schematic structure of the laser processing apparatus of the first embodiment.

[0036] [ Figure 10 (a)] is a top view showing an example of the object, [ Figure 10 (b)] is Figure 10 (a) is a side view of the object shown.

[0037] [ Figure 11 [a] is a side view of an object used to illustrate a method for manufacturing a semiconductor device using the laser processing apparatus of the first embodiment. Figure 11 (b)] For display Figure 11 (a) is a side view of the subsequent object.

[0038] [ Figure 12 (a)] is for display Figure 11 (b) The side view of the subsequent object, [ Figure 12 (b)] For display Figure 12 (a) Top view of the subsequent object, [ Figure 12 (c)] is Figure 12 (b) is a side view of the object shown.

[0039] [ Figure 13 (a)] is for display Figure 12 (b) The side view of the subsequent object, [ Figure 13 (b)] For display Figure 13 (a) is a side view of the subsequent object.

[0040] [ Figure 14 [a] is a top view showing the object to be stripped in the first embodiment. Figure 14 (b)] To make Figure 14 (a) is a magnified side view of the area within the dashed box.

[0041] [ Figure 15 [This is a top view used to illustrate the multiple modified particles formed during the peeling process in the first embodiment.]

[0042] [ Figure 16 (a)] is an image showing the cut stealth state, [ Figure 16 (b) is an image showing the half-cut state.

[0043] [ Figure 17 (a)] To display other images showing the hidden cut state, [ Figure 17 (b) is another image showing the partially cut state.

[0044] [ Figure 18[a] is an image showing the processing state after laser processing of the first specified amount, i.e., the state of complete cutting (full-cut). Figure 18 (b) is an image showing the processing state after laser processing of the second specified amount, i.e., the state of complete cutting.

[0045] [ Figure 19 This is a flowchart illustrating the stripping process of the first embodiment.

[0046] [ Figure 20 [a] is a top view of the object to be peeled in the first embodiment. Figure 20 (b)] For display Figure 20 (a) is a top view of the subsequent object.

[0047] [ Figure 21 (a)] is for display Figure 20 (b) The top view of the subsequent object, [ Figure 21 (b)] For display Figure 21 (a) is a top view of the subsequent object.

[0048] [ Figure 22 [This is a top view of an object used to illustrate the cracks extending from the modified region.]

[0049] [ Figure 23 To display Figure 22 The image shows the results of observations on the cracks in the object.

[0050] [ Figure 24 [a] is a top view of the object to be peeled off in a modified example of the first embodiment, used to illustrate the modification. Figure 24 (b)] For display Figure 24 (a) is a top view of the subsequent object.

[0051] [ Figure 25 This is an example of a GUI settings screen.

[0052] [ Figure 26 [Image showing other examples of GUI settings screens]

[0053] [ Figure 27 This is an example diagram of the administrator mode that displays the settings screen of the GUI.

[0054] [ Figure 28 [Graph showing experimental results of the optimal pulse energy for the investigation of the stripping process.]

[0055] [ Figure 29 [a] is a top view of the object to be peeled off in the second embodiment, and [29(b)] shows... Figure 29(a) is a top view of the subsequent object.

[0056] [ Figure 30 This is a flowchart illustrating the stripping process of the second embodiment.

[0057] [ Figure 31 [A flowchart showing the peeling process of a modified example of the second embodiment.]

[0058] [ Figure 32 [A flowchart illustrating the stripping process of the third embodiment.]

[0059] [ Figure 33 This is a flowchart illustrating a process example in which the semi-cutting processing conditions are determined during the peeling process of the fourth embodiment.

[0060] [ Figure 34 This is a flowchart illustrating a process example in which the first processing conditions are determined during the peeling process of the fourth embodiment.

[0061] [ Figure 35 This is a flowchart illustrating a process example in which the second processing conditions are determined during the peeling process of the fourth embodiment.

[0062] [ Figure 36 [a] is a side view of the object used to illustrate the manufacturing method of the semiconductor device in the modified example. Figure 36 (b)] For display Figure 36 (a) is a side view of the subsequent object.

[0063] [ Figure 37 [a] is a side view of the object used to illustrate the manufacturing method of a semiconductor device for other variations. Figure 37 (b)] For display Figure 37 (a) is a side view of the subsequent object.

[0064] [ Figure 38 [a] is a side view of an object used to illustrate a method for manufacturing a semiconductor device according to another variation. Figure 38 (b)] For display Figure 38 (a) is a side view of the subsequent object.

[0065] [ Figure 39 [This is a top view of the object being peeled off as a variation.]

[0066] [ Figure 40 [This is a top view of a modified laser processing apparatus.]

[0067] [ Figure 41 [This is a top view showing an example of an object.] Figure 41 (b)] is Figure 41 (a) is a side view of the object shown.

[0068] [ Figure 42 This is a top view of a laser processing apparatus used to illustrate a method of manufacturing semiconductor devices using a modified laser processing apparatus.

[0069] [ Figure 43 [a] is a side view of the object used to illustrate the method of manufacturing a semiconductor device using a modified laser processing apparatus. Figure 43 (b)] For display Figure 43 (a) is a side view of the subsequent object.

[0070] [ Figure 44 (a)] is for display Figure 43 (b) The side view of the subsequent object, [ Figure 44 (b)] For display Figure 44 (a) Top view of the subsequent object, [ Figure 44 (c)] For display Figure 44 (b) is a side view of the object shown.

[0071] [ Figure 45 This is a top view of a laser processing apparatus used to illustrate a method of manufacturing semiconductor devices using a modified laser processing apparatus.

[0072] [ Figure 46 [This is a side view of a portion of a laser processing apparatus used to illustrate a method of manufacturing semiconductor devices using a modified laser processing apparatus.]

[0073] [ Figure 47 To display Figure 44 (b) and (c) are side views of the periphery of the subsequent objects.

[0074] [ Figure 48 (a)] is for display Figure 47 The side view of the subsequent object, [ Figure 48 (b)] For display Figure 48 (a) is a side view of the subsequent object.

[0075] [ Figure 49 (a)] is a cross-sectional photograph showing the periphery of an object. Figure 49 (b)] To show that Figure 49 (a) is a magnified cross-sectional photograph of a portion of the image.

[0076] [ Figure 50 [This is a side view of a portion of a laser processing apparatus used to illustrate a method of manufacturing semiconductor devices using a modified laser processing apparatus.] Detailed Implementation

[0077] Hereinafter, the embodiments will be described in detail with reference to the drawings. In addition, in each drawing, the same or equivalent parts are given the same symbol and repeated descriptions are omitted.

[0078] First, the basic structure, function, effect, and variations of the laser processing device will be explained.

[0079] [Structure of laser processing equipment]

[0080] like Figure 1 As shown, the laser processing apparatus 1 includes: multiple moving mechanisms 5 and 6, a support 7, a pair of laser processing heads 10A and 10B, a light source unit 8, and a control unit 9. Hereinafter, the first direction will be referred to as the X direction, the second direction perpendicular to the first direction will be referred to as the Y direction, and the third direction perpendicular to both the first and second directions will be referred to as the Z direction. In this embodiment, the X and Y directions are horizontal directions, and the Z direction is a vertical direction.

[0081] The moving mechanism 5 includes a fixed part 51, a moving part 53, and a mounting part 55. The fixed part 51 is mounted on the device frame 1a. The moving part 53 is mounted on a track provided on the fixed part 51 and can move along the Y direction. The mounting part 55 is mounted on a track provided on the moving part 53 and can move along the X direction.

[0082] The moving mechanism 6 includes: a fixed part 61, a pair of moving parts 63 and 64, and a pair of mounting parts 65 and 66. The fixed part 61 is mounted on the device frame 1a. The pair of moving parts 63 and 64 are respectively mounted on tracks provided on the fixed part 61 and can move independently along the Y direction. The mounting part 65 is mounted on the track provided on the moving part 63 and can move along the Z direction. The mounting part 66 is mounted on the track provided on the moving part 64 and can move along the Z direction. That is, relative to the device frame 1a, the pair of mounting parts 65 and 66 can move in both the Y and Z directions. The moving parts 63 and 64 respectively constitute the first and second horizontal moving mechanisms. The mounting parts 65 and 66 respectively constitute the first and second vertical moving mechanisms.

[0083] The support portion 7 is mounted on the rotation axis of the mounting portion 55 provided in the moving mechanism 5, and can rotate about an axis parallel to the Z direction. That is, the support portion 7 can move in both the X and Y directions, and can rotate about an axis parallel to the Z direction. The support portion 7 supports the object 100. The object 100 is, for example, a wafer.

[0084] like Figure 1 and Figure 2As shown, laser processing head 10A is mounted on mounting portion 65 of moving mechanism 6. When facing support portion 7 in the Z direction, laser processing head 10A irradiates object 100 supported by support portion 7 with laser L1 (also called "first laser L1"). Laser processing head 10B is mounted on mounting portion 66 of moving mechanism 6. When facing support portion 7 in the Z direction, laser processing head 10B irradiates object 100 supported by support portion 7 with laser L2 (also called "second laser L2"). Laser processing heads 10A and 10B constitute the irradiation portion.

[0085] The light source unit 8 has a pair of light sources 81 and 82. Light source 81 outputs laser L1. Laser L1 is emitted from the emission section 81a of light source 81 and guided to laser processing head 10A via optical fiber 2. Light source 82 outputs laser L2. Laser L2 is emitted from the emission section 82a of light source 82 and guided to laser processing head 10B via another optical fiber 2.

[0086] The control unit 9 controls the various parts of the laser processing apparatus 1 (support unit 7, multiple moving mechanisms 5, 6, a pair of laser processing heads 10A, 10B, and light source unit 8, etc.). The control unit 9 is configured as a computer device including a processor, memory, storage, and communication devices. In the control unit 9, software (programs) read from the memory are executed by the processor, and the reading and writing of data in the memory and storage, as well as communication via the communication devices, are controlled by the processor. Thus, the control unit 9 can perform various functions.

[0087] Next, an example of processing using a laser processing apparatus 1 configured as described above will be described. In this example, the object 100 (wafer) is cut into multiple chips, and a modified region is formed inside the object 100 along multiple lines set in a lattice pattern.

[0088] First, to align the support portion 7 of the object 100 with the pair of laser processing heads 10A and 10B in the Z direction, the moving mechanism 5 moves the support portion 7 in various directions along the X and Y directions. Next, to align multiple lines extending in one direction in the object 100 along the X direction, the moving mechanism 5 rotates the support portion 7 about an axis parallel to the Z direction as its centerline.

[0089] Next, to position the focusing point (part of the focusing area) of laser L1 along a line extending in one direction, the moving mechanism 6 moves the laser processing head 10A along the Y direction. Conversely, to position the focusing point of laser L2 along another line extending in one direction, the moving mechanism 6 moves the laser processing head 10B along the Y direction. Next, to position the focusing point of laser L1 inside the object 100, the moving mechanism 6 moves the laser processing head 10A along the Z direction. Conversely, to position the focusing point of laser L2 inside the object 100, the moving mechanism 6 moves the laser processing head 10B along the Z direction.

[0090] Next, the light source 81 outputs laser L1 and the laser processing head 10A irradiates the object 100 with laser L1, while the light source 82 outputs laser L2 and the laser processing head 10B irradiates the object 100 with laser L2. Simultaneously, in order to relatively move the focusing point of laser L1 along one line extending in one direction and relatively move the focusing point of laser L2 along another line extending in one direction, the moving mechanism 5 moves the support 7 along the X direction. Thus, the laser processing apparatus 1 forms modified regions inside the object 100 along each of the multiple lines extending in one direction within the object 100.

[0091] Next, in order to make the multiple lines in the object 100 that extend in another direction orthogonal to one direction follow the X direction, the moving mechanism 5 rotates the support 7 with the axis parallel to the Z direction as the center line.

[0092] Next, to position the focusing point of laser L1 along a line extending in another direction, the moving mechanism 6 moves the laser processing head 10A along the Y direction. Conversely, to position the focusing point of laser L2 along another line extending in another direction, the moving mechanism 6 moves the laser processing head 10B along the Y direction. Next, to position the focusing point of laser L1 inside the object 100, the moving mechanism 6 moves the laser processing head 10A along the Z direction. Conversely, to position the focusing point of laser L2 inside the object 100, the moving mechanism 6 moves the laser processing head 10B along the Z direction.

[0093] Next, the light source 81 outputs laser L1 and the laser processing head 10A irradiates the object 100 with laser L1, while the light source 82 outputs laser L2 and the laser processing head 10B irradiates the object 100 with laser L2. Simultaneously, in order to relatively move the focusing point of laser L1 along one line extending in another direction and relatively move the focusing point of laser L2 along another line extending in another direction, the moving mechanism 5 moves the support 7 along the X direction. Thus, the laser processing apparatus 1 forms modified regions within the object 100 along each of the multiple lines extending in a direction orthogonal to one direction.

[0094] In another example of the aforementioned processing, light source 81 outputs laser L1, which is penetrable to the object 100, using, for example, pulse oscillation. Light source 82 outputs laser L2, which is penetrable to the object 100, using, for example, pulse oscillation. If such laser light is focused inside the object 100, the laser is particularly absorbed at the point corresponding to the focal point, thus forming a modified region inside the object 100. The modified region is a region whose physical properties, such as density, refractive index, and mechanical strength, differ from the surrounding unmodified region. Examples of modified regions include, for example, melt-processed regions, cracked regions, insulation-damaged regions, and regions with refractive index changes.

[0095] If a laser output using pulse oscillation is applied to an object 100, and the laser's focusing point is moved relative to a line set on the object 100, multiple modified particles will be formed in a row along the line. Each modified particle is formed by irradiation with one laser pulse. A row of modified regions is a collection of multiple modified particles arranged in that row. Adjacent modified particles may be connected or separated depending on the relative movement speed of the laser focusing point relative to the object 100 and the laser repetition frequency. The shape of the set line is not limited to a lattice pattern; it can be a ring, a straight line, a curve, or a combination of at least one of these.

[0096] [Structure of the laser processing head]

[0097] like Figure 3 and Figure 4 As shown, the laser processing head 10A includes: a housing 11, an incident part 12, an adjustment part 13, and a focusing part 14.

[0098] The housing 11 has: a first wall portion 21 and a second wall portion 22, a third wall portion 23 and a fourth wall portion 24, and a fifth wall portion 25 and a sixth wall portion 26. The first wall portion 21 and the second wall portion 22 face each other in the X direction. The third wall portion 23 and the fourth wall portion 24 face each other in the Y direction. The fifth wall portion 25 and the sixth wall portion 26 face each other in the Z direction.

[0099] The distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22. The distance between the first wall portion 21 and the second wall portion 22 is smaller than the distance between the fifth wall portion 25 and the sixth wall portion 26. Alternatively, the distance between the first wall portion 21 and the second wall portion 22 may be equal to or greater than the distance between the fifth wall portion 25 and the sixth wall portion 26.

[0100] In the laser processing head 10A, the first wall portion 21 is located on the side opposite to the fixed portion 61 of the moving mechanism 6, and the second wall portion 22 is located on the side of the fixed portion 61. The third wall portion 23 is located on the side of the mounting portion 65 of the moving mechanism 6, and the fourth wall portion 24 is located on the side opposite to the mounting portion 65, i.e., on the side of the laser processing head 10B (see reference). Figure 2 The fifth wall portion 25 is located on the opposite side of the support portion 7, and the sixth wall portion 26 is located on the side of the support portion 7.

[0101] The housing 11 is configured such that the housing 11 is mounted on the mounting portion 65 with the third wall portion 23 disposed on the mounting portion 65 side of the moving mechanism 6. Specifically, it is described below. The mounting portion 65 has a base plate 65a and a mounting plate 65b. The base plate 65a is mounted on a track provided on the moving portion 63 (see reference). Figure 2 Mounting plate 65b is vertically mounted on the end of the base plate 65a on the side of the laser processing head 10B (see reference). Figure 2 With the third wall portion 23 in contact with the mounting plate 65b, bolts 28 are screwed onto the mounting plate 65b via the base 27, thereby mounting the housing 11 onto the mounting portion 65. The base 27 is provided on each of the first wall portion 21 and the second wall portion 22. The housing 11 is removable from the mounting portion 65.

[0102] The incident portion 12 is mounted on the fifth wall portion 25. The incident portion 12 allows the laser L1 to enter the housing 11. The incident portion 12 is located near the second wall portion 22 (one of the wall portions) in the X direction and near the fourth wall portion 24 in the Y direction. That is, the distance between the incident portion 12 and the second wall portion 22 in the X direction is smaller than the distance between the incident portion 12 and the first wall portion 21 in the X direction; the distance between the incident portion 12 and the fourth wall portion 24 in the Y direction is smaller than the distance between the incident portion 12 and the third wall portion 23 in the X direction.

[0103] The incident section 12 is configured such that the connecting end 2a of the optical fiber 2 is connectable. At the connecting end 2a of the optical fiber 2, a collimating lens is provided for collimating the laser L1 emitted from the emitting end of the optical fiber, but an isolator for suppressing return light is not provided. This isolator is located along the optical fiber closer to the light source 81 than at the connecting end 2a. This allows for miniaturization of the connecting end 2a, and consequently, miniaturization of the incident section 12. Alternatively, an isolator could also be provided at the connecting end 2a of the optical fiber 2.

[0104] An adjustment unit 13 is disposed within the housing 11. The adjustment unit 13 is used to adjust the laser L1 incident from the incident section 12. The various structures of the adjustment unit 13 are mounted on an optical base 29 disposed within the housing 11. The optical base 29 is mounted on the housing 11 in such a way that it divides the area within the housing 11 into an area on the side of the third wall portion 23 and an area on the side of the fourth wall portion 24. The optical base 29 is integral with the housing 11. The various structures of the adjustment unit 13 are mounted on the optical base 29 on the side of the fourth wall portion 24. The various structures of the adjustment unit 13 will be described in detail later.

[0105] A light-concentrating part 14 is disposed on the sixth wall portion 26. Specifically, the light-concentrating part 14 is inserted through a hole 26a formed in the sixth wall portion 26 (see reference). Figure 5 The laser beam 14 is disposed on the sixth wall portion 26. The focusing portion 14 focuses the laser L1, adjusted by the adjusting portion 13, and emits it out of the housing 11. The focusing portion 14 is located near the second wall portion 22 (one of the wall portions) in the X direction and near the fourth wall portion 24 in the Y direction. That is, the distance between the focusing portion 14 and the second wall portion 22 in the X direction is smaller than the distance between the focusing portion 14 and the first wall portion 21 in the X direction, and the distance between the focusing portion 14 and the fourth wall portion 24 in the Y direction is smaller than the distance between the focusing portion 14 and the third wall portion 23 in the X direction.

[0106] like Figure 5 As shown, the adjustment unit 13 includes an attenuator 31, a beam expander 32, and a reflector 33. The attenuator 31, beam expander 32, and reflector 33 of the incident part 12 and the adjustment unit 13 are arranged on a straight line (first straight line) A1 extending along the Z direction. The attenuator 31 and beam expander 32 are arranged on straight line A1 between the incident part 12 and the reflector 33. The attenuator 31 is used to adjust the power of the laser L1 incident from the incident part 12. The beam expander 32 enlarges the aperture of the laser L1 after its power is adjusted by the attenuator 31. The reflector 33 reflects the laser L1 after its diameter is enlarged by the beam expander 32.

[0107] The adjustment unit 13 further includes a reflective spatial light modulator 34 and an imaging optical system 35. The reflective spatial light modulator 34, the imaging optical system 35, and the focusing unit 14 of the adjustment unit 13 are arranged on a straight line (the second straight line) A2 extending along the Z direction. The reflective spatial light modulator 34 modulates the laser L1 reflected by the reflecting mirror 33. The reflective spatial light modulator 34 is, for example, a spatial light modulator (SLM) of reflective liquid crystal on silicon (LCOS). The imaging optical system 35 is a biaxially telecentric optical system configured to place the reflecting surface 34a of the reflective spatial light modulator 34 and the entrance pupil surface 14a of the focusing unit 14 in an imaging relationship. The imaging optical system 35 is composed of three or more lenses.

[0108] Lines A1 and A2 are located on a plane perpendicular to the Y direction. Line A1 is located on the side of the second wall portion 22 (one side of the wall portion) relative to line A2. In the laser processing head 10A, laser L1 enters the housing 11 from the incident portion 12 and travels along line A1. After being reflected sequentially by the reflector 33 and the reflective spatial light modulator 34, it travels along line A2 and is emitted from the focusing portion 14 out of the housing 11. Alternatively, the arrangement order of the attenuator 31 and the beam expander 32 can be reversed. Furthermore, the attenuator 31 can also be positioned between the reflector 33 and the reflective spatial light modulator 34. Additionally, the adjustment portion 13 may include other optical components (e.g., a steering mirror positioned in front of the beam expander 32).

[0109] The laser processing head 10A further includes: a dichroic mirror 15, a measuring unit 16, an observation unit 17, a driving unit 18, and a circuit unit 19.

[0110] A dichroic mirror 15 is disposed between the imaging optical system 35 and the focusing section 14 along line A2. Specifically, the dichroic mirror 15 is disposed within the housing 11 between the adjustment section 13 and the focusing section 14. The dichroic mirror 15 is mounted on the optical base 29 on the fourth wall side 24. The dichroic mirror 15 allows the laser L1 to pass through. Based on the viewpoint of suppressing astigmatism, the dichroic mirror 15 is, for example, cubic in shape, or configured as two plates with a skewed relationship.

[0111] The measuring unit 16 is disposed within the housing 11 on the side of the first wall portion 21 (opposite to the side of one of the wall portions) relative to the adjustment unit 13. The measuring unit 16 is mounted on the optical base 29 on the side of the fourth wall portion 24. The measuring unit 16 outputs measuring light L10 for measuring the distance between the surface of the object 100 (e.g., the surface on the incident side of laser L1) and the focusing unit 14, and detects the measuring light L10 reflected by the surface of the object 100 via the focusing unit 14. That is, the measuring light L10 output from the measuring unit 16 is irradiated onto the surface of the object 100 via the focusing unit 14, and the measuring light L10 reflected by the surface of the object 100 is detected by the measuring unit 16 via the focusing unit 14.

[0112] More specifically, the measurement light L10 output from the measurement unit 16 is sequentially reflected by the beam splitter 20 and the dichroic mirror 15 mounted on the optical base 29 on the fourth wall 24 side, and then emitted from the focusing unit 14 out of the housing 11. The measurement light L10, after being reflected by the surface of the object 100, enters the housing 11 from the focusing unit 14 and is sequentially reflected by the dichroic mirror 15 and the beam splitter 20, and then enters the measurement unit 16 for detection.

[0113] The observation unit 17 is disposed within the housing 11 on the side of the first wall portion 21 (opposite to one of the wall portions) relative to the adjustment unit 13. The observation unit 17 is mounted on the optical base 29 on the side of the fourth wall portion 24. The observation unit 17 outputs observation light L20 for observing the surface of the object 100 (e.g., the surface on the incident side of laser L1) and detects the observation light L20 reflected by the surface of the object 100 via the focusing unit 14. In other words, the observation light L20 output from the observation unit 17 is the light that is irradiated onto the surface of the object 100 via the focusing unit 14, and the observation light L20 reflected by the surface of the object 100 is detected by the observation unit 17 via the focusing unit 14.

[0114] More specifically, the observation light L20 output from the observation unit 17 is reflected by the dichroic mirror 15 after passing through the beam splitter 20, and then emitted from the focusing unit 14 out of the housing 11. The observation light L20, after being reflected by the surface of the object 100, enters the housing 11 from the focusing unit 14, is reflected by the dichroic mirror 15, passes through the beam splitter 20, and enters the observation unit 17, where it is detected. In addition, the wavelengths of the laser L1, the measuring light L10, and the observation light L20 are all different from each other (at least their center wavelengths are offset from each other).

[0115] The drive unit 18 is mounted on the optical base 29 on the side of the fourth wall 24. The drive unit 18 moves the focusing part 14 disposed on the sixth wall 26 along the Z direction by driving force, for example, a piezoelectric element.

[0116] The circuit section 19 is disposed on the third wall 23 side within the housing 11, relative to the optical base 29. That is, the circuit section 19 is disposed on the third wall 23 side within the housing 11, relative to the adjustment section 13, the measuring section 16, and the observation section 17. The circuit section 19 is, for example, a plurality of circuit boards. The circuit section 19 is used to process signals output from the measuring section 16 and signals input to the reflective spatial light modulator 34. The circuit section 19 controls the drive section 18 based on the signals output from the measuring section 16. As an example, the circuit section 19 controls the drive section 18 in a manner that maintains a constant distance between the surface of the object 100 and the focusing section 14 (i.e., maintains a constant distance between the surface of the object 100 and the focusing point of the laser L1) based on the signals output from the measuring section 16. Additionally, a connector (not shown) is provided in the housing 11 for electrically connecting the circuit section 19 to the control section 9 (see reference 1). Figure 1 Wiring connections, etc.

[0117] The laser processing head 10B, like the laser processing head 10A, includes: a housing 11, an incident section 12, an adjustment section 13, a focusing section 14, a dichroic mirror 15, a measuring section 16, an observation section 17, a driving section 18, and a circuit section 19. However, the structures of the laser processing head 10B are as follows: Figure 2 As shown, the structure of the laser processing head 10A is symmetrical about an imaginary plane that passes through the midpoint between the pair of mounting parts 65 and 66 and is perpendicular to the Y direction.

[0118] For example, the housing (first housing) 11 of the laser processing head 10A is mounted on the mounting portion 65 such that the fourth wall portion 24 is located on the laser processing head 10B side relative to the third wall portion 23 and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25. In contrast, the housing (second housing) 11 of the laser processing head 10B is mounted on the mounting portion 66 such that the fourth wall portion 24 is located on the laser processing head 10A side relative to the third wall portion 23 and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25.

[0119] The housing 11 of the laser processing head 10B is configured such that the housing 11 is mounted on the mounting portion 66 with the third wall portion 23 disposed on the mounting portion 66 side. Specifically, it is described below. The mounting portion 66 includes a base plate 66a and a mounting plate 66b. The base plate 66a is mounted on a track provided on the moving portion 63. The mounting plate 66b is erected at the end of the base plate 66a on the laser processing head 10A side. The housing 11 of the laser processing head 10B is mounted on the mounting portion 66 with the third wall portion 23 in contact with the mounting plate 66b. The housing 11 of the laser processing head 10B is detachable from the mounting portion 66.

[0120] [Functions and Effects]

[0121] In the laser processing head 10A, since the light source for outputting the laser L1 is not located within the housing 11, miniaturization of the housing 11 is possible. Furthermore, within the housing 11, the distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22, causing the focusing portion 14 disposed on the sixth wall portion 26 to be positioned closer to the fourth wall portion 24 in the Y direction. Thus, when the housing 11 is moved along a direction perpendicular to the optical axis of the focusing portion 14, even if other structures (such as the laser processing head 10B) exist on the fourth wall portion 24 side, the focusing portion 14 can still be brought closer to those other structures. Therefore, the laser processing head 10A is suitable for moving the focusing portion 14 along a direction perpendicular to its optical axis.

[0122] Furthermore, in the laser processing head 10A, the incident portion 12 is provided on the fifth wall portion 25, which is adjacent to the fourth wall portion 24 in the Y direction. In this way, other structures (e.g., circuit portion 19) can be arranged in the area within the housing 11 that is adjacent to the third wall portion 23 relative to the adjustment portion 13, and this area can be utilized effectively.

[0123] Furthermore, in the laser processing head 10A, the focusing part 14 is positioned against the second wall 22 side in the X direction. Thus, when the housing 11 is moved in a direction perpendicular to the optical axis of the focusing part 14, even if other structures exist on the second wall 22 side, the focusing part 14 can still be brought close to those other structures.

[0124] Furthermore, in the laser processing head 10A, the incident portion 12 is provided on the fifth wall portion 25, which is adjacent to the second wall portion 22 in the X direction. In this way, other structures (e.g., the measuring portion 16 and the observing portion 17) can be arranged in the area within the housing 11 that is adjacent to the first wall portion 21 relative to the adjusting portion 13, and this area can be utilized effectively.

[0125] Furthermore, in the laser processing head 10A, the measuring section 16 and the observing section 17 are disposed in the region within the housing 11 on the side of the first wall portion 21 relative to the adjusting section 13; the circuit section 19 is disposed in the region within the housing 11 on the side of the third wall portion 23 relative to the adjusting section 13; and the dichroic mirror 15 is disposed within the housing 11 between the adjusting section 13 and the focusing section 14. In this way, the region within the housing 11 can be utilized effectively. Moreover, in the laser processing apparatus 1, processing based on the measurement results of the distance between the surface of the object 100 and the focusing section 14 can be performed. Furthermore, in the laser processing apparatus 1, processing based on the observation results of the surface of the object 100 can be performed.

[0126] Furthermore, in the laser processing head 10A, the circuit section 19 controls the drive section 18 based on the signal output from the measurement section 16. Thus, the position of the focusing point of the laser L1 can be adjusted based on the measurement results of the distance between the surface of the object 100 and the focusing section 14.

[0127] Furthermore, in the laser processing head 10A, the attenuator 31, beam expander 32, and reflector 33 of the incident section 12 and the adjustment section 13 are arranged on a straight line A1 extending along the Z direction. The reflective spatial light modulator 34, imaging optical system 35, and focusing section 14 of the adjustment section 13 are arranged on a straight line A2 extending along the Z direction. In this way, the adjustment section 13, which includes the attenuator 31, beam expander 32, reflective spatial light modulator 34, and imaging optical system 35, can be configured to be compact.

[0128] Furthermore, in the laser processing head 10A, line A1 is located on the side of the second wall portion 22 relative to line A2. Thus, in the region within the housing 11 that is on the side of the first wall portion 21 relative to the adjustment portion 13, other optical systems (e.g., measuring portion 16 and observing portion 17) using the focusing portion 14 can be configured, increasing the degree of freedom in the configuration of these other optical systems.

[0129] The same functions and effects can be achieved in the laser processing head 10B.

[0130] Furthermore, in the laser processing apparatus 1, the focusing portion 14 of the laser processing head 10A is located inside the housing 11 of the laser processing head 10A, adjacent to the side of the laser processing head 10B, and the focusing portion 14 of the laser processing head 10B is located inside the housing 11 of the laser processing head 10B, adjacent to the side of the laser processing head 10A. Thus, when the pair of laser processing heads 10A and 10B are moved along the Y direction, the focusing portions 14 of the laser processing head 10A and the laser processing head 10B can be brought closer together. Therefore, according to the laser processing apparatus 1, the object 100 can be processed efficiently and effectively.

[0131] Furthermore, the mounting portions 65 and 66 of the laser processing apparatus 1 can move along the Y and Z directions, respectively. This allows for more efficient processing of the object 100.

[0132] Furthermore, in the laser processing apparatus 1, the support 7 moves along both the X and Y directions and rotates about an axis parallel to the Z direction. This allows for more efficient processing of the object 100.

[0133] [Variation Example]

[0134] For example, such as Figure 6As shown, the incident section 12, the adjustment section 13, and the focusing section 14 can also be arranged on a straight line A extending along the Z direction. This allows the adjustment section 13 to be configured compactly. In this case, the adjustment section 13 may also omit the reflective spatial light modulator 34 and the imaging optical system 35. Furthermore, the adjustment section 13 may also include an attenuator 31 and a beam expander 32. This allows the adjustment section 13 with the attenuator 31 and beam expander 32 to be configured compactly. Additionally, the arrangement order of the attenuator 31 and beam expander 32 can be reversed.

[0135] Furthermore, the housing 11 only needs to be configured such that at least one of the first wall portion 21, the second wall portion 22, the third wall portion 23, and the fifth wall portion 25 is disposed on the mounting portion 65 (or mounting portion 66) side of the laser processing apparatus 1, and the housing 11 is then mounted on the mounting portion 65 (or mounting portion 66). Furthermore, the focusing portion 14 only needs to be positioned at least in the Y direction against the fourth wall portion 24. Thus, when the housing 11 is moved along the Y direction, for example, even if other structures exist on the fourth wall portion 24 side, the focusing portion 14 can still be brought closer to those other structures. Furthermore, when the housing 11 is moved along the Z direction, for example, the focusing portion 14 can be brought closer to the object 100.

[0136] Furthermore, the focusing section 14 can also be positioned against the first wall section 21 in the X direction. Thus, when the housing 11 is moved along a direction perpendicular to the optical axis of the focusing section 14, even if other structures exist on the first wall section 21 side, the focusing section 14 can still be brought close to those other structures. In this case, the incident section 12 can also be positioned against the first wall section 21 side in the X direction. In this way, other structures (e.g., the measuring section 16 and the observation section 17), etc., can be arranged in the area within the housing 11 opposite to the second wall section 22 side of the adjusting section 13, and this area can be utilized effectively.

[0137] Furthermore, at least one of the following can be implemented using a reflector: guiding the laser L1 from the emission portion 81a of the light source unit 8 to the incident portion 12 of the laser processing head 10A, and guiding the laser L2 from the emission portion 82a of the light source unit 8 to the incident portion 12 of the laser processing head 10B. Figure 7 A front view of a portion of the laser processing apparatus 1 in which laser L1 is guided by a reflector. Figure 7 The structure shown shows that the reflector 3 for reflecting the laser L1 is mounted on the moving part 63 of the moving mechanism 6 in such a way that it faces the emission part 81a of the light source unit 8 in the Y direction and faces the incident part 12 of the laser processing head 10A in the Z direction.

[0138] exist Figure 7The structure shown allows the mirror 3 to remain facing the emission portion 81a of the light source unit 8 even when the moving part 63 of the moving mechanism 6 moves along the Y direction. Furthermore, even when the mounting part 65 of the moving mechanism 6 moves along the Z direction, the mirror 3 can remain facing the incident portion 12 of the laser processing head 10A in the Z direction. Therefore, regardless of the position of the laser processing head 10A, the laser L1 emitted from the emission portion 81a of the light source unit 8 can reliably enter the incident portion 12 of the laser processing head 10A. Moreover, it allows the use of light sources such as high-power long / short pulse lasers that are difficult to guide through the optical fiber 2.

[0139] In addition, Figure 7 As shown in the structure, the reflector 3 can also be mounted on the moving part 63 of the moving mechanism 6 in a manner that allows for at least one of angle adjustment and position adjustment. In this way, the laser L1 emitted from the emission part 81a of the light source unit 8 can more reliably enter the incident part 12 of the laser processing head 10A.

[0140] Furthermore, the light source unit 8 may also have a single light source. In this case, the light source unit 8 only needs to be configured such that a portion of the laser output from the single light source is emitted from the emission section 81a and the other portion of the laser is emitted from the emission section 82b.

[0141] Furthermore, the laser processing apparatus 1 may also include a single laser processing head 10A. Even with a single laser processing head 10A, when the housing 11 is moved along the Y direction perpendicular to the optical axis of the focusing portion 14, the focusing portion 14 can be brought close to other structures, for example, on the side of the fourth wall portion 24. Thus, with the laser processing apparatus 1 equipped with a single laser processing head 10A, the object 100 can be processed efficiently. Furthermore, in the laser processing apparatus 1 equipped with a single laser processing head 10A, if the mounting portion 65 is moved along the Z direction, the object 100 can be processed even more efficiently. Furthermore, in the laser processing apparatus 1 equipped with a single laser processing head 10A, if the support portion 7 is moved along the X direction and rotated about an axis parallel to the Z direction as its centerline, the object 100 can be processed even more efficiently.

[0142] In addition, the laser processing device 1 may also have more than three laser processing heads. Figure 8 A perspective view of a laser processing device 1 equipped with two pairs of laser processing heads. Figure 8 The laser processing apparatus 1 shown includes: multiple moving mechanisms 200, 300, 400, support 7, a pair of laser processing heads 10A, 10B, a pair of laser processing heads 10C, 10D, and a light source unit (figure omitted).

[0143] The moving mechanism 200 moves the support 7 along the X, Y and Z directions and rotates the support 7 about an axis parallel to the Z direction as its centerline.

[0144] The moving mechanism 300 includes a fixed part 301 and a pair of mounting parts (first mounting part and second mounting part) 305 and 306. The fixed part 301 is mounted on the device frame (figure omitted). The pair of mounting parts 305 and 306 are respectively mounted on a track provided on the fixed part 301, and can move independently along the Y direction.

[0145] The moving mechanism 400 includes a fixed part 401 and a pair of mounting parts (first mounting part and second mounting part) 405 and 406. The fixed part 401 is mounted on the device frame (not shown in the figure). The pair of mounting parts 405 and 406 are respectively mounted on the track provided on the fixed part 401, and can move independently along the X direction. In addition, the track of the fixed part 401 is arranged to intersect the track of the fixed part 301 three-dimensionally.

[0146] A laser processing head 10A is mounted on the mounting portion 305 of the moving mechanism 300. The laser processing head 10A, facing the support portion 7 in the Z direction, irradiates the object 100 supported by the support portion 7 with a laser. The laser emitted from the laser processing head 10A is guided from the light source unit (not shown) through the optical fiber 2. A laser processing head 10B is mounted on the mounting portion 306 of the moving mechanism 300. The laser processing head 10B, facing the support portion 7 in the Z direction, irradiates the object 100 supported by the support portion 7 with a laser. The laser emitted from the laser processing head 10B is guided from the light source unit (not shown) through the optical fiber 2.

[0147] A laser processing head 10C is mounted on the mounting portion 405 of the moving mechanism 400. The laser processing head 10C, facing the support portion 7 in the Z direction, irradiates the object 100 supported by the support portion 7 with a laser. The laser emitted from the laser processing head 10C is guided from the light source unit (not shown) through the optical fiber 2. A laser processing head 10D is mounted on the mounting portion 406 of the moving mechanism 400. The laser processing head 10D, facing the support portion 7 in the Z direction, irradiates the object 100 supported by the support portion 7 with a laser. The laser emitted from the laser processing head 10D is guided from the light source unit (not shown) through the optical fiber 2.

[0148] Figure 8 The configuration of the pair of laser processing heads 10A and 10B in the laser processing apparatus 1 shown is similar to... Figure 1 The pair of laser processing heads 10A and 10B of the laser processing apparatus 1 shown have the same configuration. Figure 8The configuration of the pair of laser processing heads 10C and 10D in the laser processing apparatus 1 shown is related to the laser processing head... Figure 1 The laser processing heads 10A and 10B of the laser processing apparatus 1 shown are configured identically when rotated 90° around an axis parallel to the Z direction.

[0149] For example, the housing (first housing) 11 of the laser processing head 10C is mounted on the mounting portion 65 such that the fourth wall portion 24 is located on the laser processing head 10D side relative to the third wall portion 23 and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25. The focusing portion 14 of the laser processing head 10C is located on the side of the fourth wall portion 24 (i.e., the laser processing head 10D side) in the Y direction.

[0150] The housing (second housing) 11 of the laser processing head 10D is mounted on the mounting portion 66 such that the fourth wall portion 24 is located on the laser processing head 10C side relative to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25. The focusing portion 14 of the laser processing head 10D is located on the side of the fourth wall portion 24 (i.e., the laser processing head 10C side) in the Y direction.

[0151] Based on the above structure, Figure 8 The laser processing apparatus 1 shown allows the focusing portions 14 of laser processing head 10A and 10B to move closer together when the pair of laser processing heads 10A and 10B are moved along the Y direction. Furthermore, when the pair of laser processing heads 10C and 10D are moved along the X direction, the focusing portions 14 of laser processing head 10C and 10D can also move closer together.

[0152] Furthermore, the laser processing head and laser processing apparatus are not limited to forming a modified region inside the object 100, but can also be used for performing other laser processing.

[0153] The following describes each embodiment. Descriptions that are repeated in the above embodiments will be omitted. Embodiments 1 to 3 are reference embodiments.

[0154] [First Implementation]

[0155] Figure 9The laser processing apparatus 101 shown irradiates a workpiece 100 with a laser beam in a manner that aligns a focal point (at least a portion of the focal area), thereby forming a modified region on the workpiece 100. The laser processing apparatus 101 performs trimming and stripping processes on the workpiece 100 to obtain (manufacture) a semiconductor device. Trimming is a process used to remove unwanted portions from the workpiece 100. Stripping is a process used to peel off a portion of the workpiece 100.

[0156] Object 100 includes, for example, a semiconductor wafer formed in a circular plate shape. There are no particular limitations on the object; it can be formed from various materials and can take on various shapes. Functional elements (not shown) are formed on the surface 100a of object 100. These functional elements are, for example, light-receiving elements such as photodiodes, light-emitting elements such as laser diodes, and circuit elements such as memory.

[0157] like Figure 10 (a) and Figure 10 As shown in (b), an effective region R and a removed region E are defined in the object 100. The effective region R is the portion corresponding to the semiconductor device to be obtained. For example, the effective region R is a circular plate-shaped portion including the central part when the object 100 is viewed from the thickness direction. The removed region E is the region in the object 100 that is further outward than the effective region R. The removed region E is the outer edge portion of the object 100 excluding the effective region R. For example, the removed region E is an annular portion surrounding the effective region R. When the object 100 is viewed from the thickness direction, the removed region E includes the peripheral portion (the beveled portion of the outer edge).

[0158] An imaginary surface M1 is set on the object 100 as the predetermined surface for peeling. The imaginary surface M1 is the surface on which the modified region is to be formed. The imaginary surface M1 is the surface opposite to the laser incident surface of the object 100, i.e., the back surface 100b. The imaginary surface M1 is parallel to the back surface 100b, and is, for example, circular. The imaginary surface M1 is an imaginary region, not limited to a plane, and can also be a curved surface or a three-dimensional surface. The effective region R, the removal region E, and the imaginary surface M1 can be set in the control unit 9. The effective region R, the removal region E, and the imaginary surface M1 can also be assigned coordinates.

[0159] A line M3 is set on the object 100 as a predetermined trimming line. Line M3 is a line that is intended to form a modified region. Line M3 extends in a loop on the inner side of the outer edge of the object 100. Here, line M3 extends in a circular loop. Line M3 is set on the part of the object 100 that is closer to the laser incident surface than the imaginary surface M1, at the boundary between the effective region R and the removal region E. The setting of line M3 can be performed in the control unit 9. Although line M3 is an imaginary line, it can also be an actual drawn line. The coordinates of line M3 can also be assigned.

[0160] like Figure 9 As shown, the laser processing apparatus 101 includes: a stage 107, a laser processing head 10A, a first Z-axis track 106A, a Y-axis track 108, a camera unit 110, a GUI (Graphical User Interface) 111, and a control unit 9. The stage 107 is a support for placing the object 100. The stage 107 is configured to work in conjunction with the aforementioned support unit 7 (see reference 108). Figure 1 The same applies. In this embodiment, the stage 107 holds the object 100 with its back surface 100b facing the laser incident surface (i.e., the upper side) and its surface 100a facing the stage 107 (i.e., the lower side). The stage 107 has a rotation axis C disposed at its center. The rotation axis C is an axis extending along the Z direction. The stage 107 can rotate about the rotation axis C. The stage 107 is driven to rotate by the driving force of a known drive device such as a motor.

[0161] The laser processing head 10A irradiates the object 100 placed on the stage 107 with the first laser L1 along the Z direction (see reference). Figure 11 (a)) and a modified region is formed inside the object 100. The laser processing head 10A is mounted on the first Z-axis track 106A and the Y-axis track 108. The laser processing head 10A can move linearly in the Z direction along the first Z-axis track 106A by the driving force of a known drive device such as a motor. The laser processing head 10A can move linearly in the Y direction along the Y-axis track 108 by the driving force of a known drive device such as a motor. The laser processing head 10A constitutes the irradiation section.

[0162] The laser processing head 10A includes a reflective spatial light modulator 34 as described above. The laser processing head 10A also includes a range sensor 36. The range sensor 36 emits a range-measuring laser towards the laser incident surface of the object 100, detects the range-measuring light reflected from the laser incident surface, and thereby obtains displacement data of the laser incident surface of the object 100. As the range sensor 36, when it is a sensor coaxial with the first laser L1, sensors using triangulation, laser confocal, white confocal, beam splitting interference, or astigmatism methods can be used. As the range sensor 36, when it is coaxial with the first laser L1, sensors using astigmatism methods can be used. The circuit section 19 of the laser processing head 10A (see reference...) Figure 3 Based on the displacement data obtained by the ranging sensor 36, the drive unit 18 is driven in such a way that the focusing unit 14 tracks the laser incident surface (see reference). Figure 5Therefore, in order to maintain a constant distance between the laser incident surface of the object 100 and the focusing point of the first laser L1, i.e., the first focusing point, the focusing part 14 is moved along the Z direction according to the displacement data.

[0163] The first Z-axis track 106A is a track extending along the Z direction. The first Z-axis track 106A is mounted on the laser processing head 10A via the mounting part 65. The first Z-axis track 106A is used to move the laser processing head 10A along the Z direction so that the first focusing point of the first laser L1 moves along the Z direction (the direction intersecting the imaginary plane M1). The first Z-axis track 106A corresponds to the aforementioned moving mechanism 6 (see reference 6). Figure 1 ) or the aforementioned mobile mechanism 300 (refer to Figure 8 () orbit.

[0164] Y-axis track 108 is a track extending along the Y direction. Y-axis track 108 is mounted on the first Z-axis track 106A. Y-axis track 108 is used to move the laser processing head 10A along the Y direction so that the first focusing point of the first laser L1 moves along the Y direction (along the direction of the imaginary surface M1). Y-axis track 108 corresponds to the aforementioned moving mechanism 6 (see reference 6). Figure 1 ) or the aforementioned mobile mechanism 300 (refer to Figure 8 () orbit.

[0165] The imaging unit 110 captures images of the object 100 from the direction of incident along the first laser L1. The imaging unit 110 includes an alignment camera AC and an imaging unit IR. The alignment camera AC and the imaging unit IR are mounted together with the laser processing head 10A on the mounting unit 65. The alignment camera AC captures images of device patterns, for example, using light that penetrates the object 100. The resulting image is used for aligning the position of the first laser L1 irradiation on the object 100.

[0166] The imaging unit IR captures images of the object 100 using light that penetrates it. For example, when the object 100 is a silicon-containing wafer, the imaging unit IR uses near-infrared light. The imaging unit IR includes a light source, an objective lens, and a light detection unit. The light source outputs light that is penetrable to the object 100. The light source is, for example, composed of a halogen lamp and a filter, and outputs near-infrared light. The light output from the light source is guided by an optical system such as a mirror and passes through the objective lens to illuminate the object 100.

[0167] An objective lens allows light reflected from the surface opposite to the laser incident surface of the object 100 to pass through. In other words, an objective lens allows light to pass through after propagating (penetrating) through the object 100. The numerical aperture (NA) of the objective lens is, for example, 0.45 or greater. The objective lens has a correction ring. The correction ring corrects aberrations caused by light within the object 100 by adjusting the distance between the multiple lenses constituting the objective lens, for example. A light detection unit detects the light passing through the objective lens. The light detection unit is, for example, constructed using an InGaAs camera, for detecting light in the near-infrared region. An imaging unit IR can image at least one of the modified region formed inside the object 100 and cracks extending from the modified region. That is, in the laser processing apparatus 101, the processing state of the laser processing can be non-destructively confirmed using the imaging unit IR. The imaging unit IR is configured as a processing state monitoring unit that monitors (internal monitoring) the processing state of the laser processing inside the object 100.

[0168] The GUI111 displays various information. The GUI111 includes, for example, a touch panel display. Users input various settings regarding processing conditions into the GUI111 through touch or other operations. The GUI111 is an input unit that receives input from the user.

[0169] The control unit 9 is configured as a computer device including a processor, memory, storage, and communication devices. In the control unit 9, software (programs) read from the memory are executed by the processor, and the reading and writing of data in the memory and storage, as well as communication via the communication devices, are controlled by the processor. The control unit 9 controls all parts of the laser processing apparatus 101, thereby realizing various functions.

[0170] The control unit 9 controls at least the stage 107, the laser processing head 10A, and the aforementioned moving mechanism 6 (see reference). Figure 1 ) or the aforementioned mobile mechanism 300 (refer to Figure 1 The control unit 9 controls the rotation of the stage 107, the irradiation of the first laser L1 from the laser processing head 10A, and the movement of the first focusing point of the first laser L1. The control unit 9 can perform various controls based on rotation information (hereinafter also referred to as "θ information") regarding the amount of rotation of the stage 107. The θ information can be obtained based on the drive amount of the drive device that rotates the stage 107, or it can be obtained through other sensors, etc. The θ information can be obtained using various known methods. Here, the θ information includes the rotation angle based on the state when the object 100 is located in the 0° direction.

[0171] The control unit 9, while rotating the stage 107 and positioning the first focusing point along line M3 (the periphery of the effective region R) of the object 100, controls the start and stop of the irradiation of the first laser L1 of the laser processing head 10A based on θ information, thereby performing a trimming process to form a modified region along the periphery of the effective region R. This trimming process is performed by the control unit 9. In this embodiment, the trimming process involves irradiating the object 100 along line M3, on the side opposite to the laser incident surface that is further from the imaginary surface M1 than the surface to which the first laser L1 is applied, before the peeling process (the first processing described later), to form a modified region.

[0172] The control unit 9 rotates the stage 107 while irradiating the first laser L1 from the laser processing head 10A, and controls the movement of the first focusing point in the Y direction, thereby performing a peeling process to form a modified region along the imaginary surface M1 inside the object 100. The peeling process is handled by the control unit 9. The control unit 9 controls the display of the GUI 111. Trimming and peeling processes are performed based on various settings input from the GUI 111.

[0173] The formation and cessation of the modified region can be achieved as follows. For example, in the laser processing head 10A, the formation and cessation of the modified region can be switched by switching the start and stop (ON / OFF) of the irradiation (output) of the first laser L1. Specifically, when the laser oscillator is composed of a solid-state laser, the start and stop of the irradiation of the first laser L1 can be switched rapidly by switching the ON / OFF of the Q-switch (AOM (acousto-optic modulator), EOM (electro-optic modulator), etc.) provided in the resonator. When the laser oscillator is composed of a fiber laser, the start and stop of the irradiation of the first laser L1 can be switched rapidly by switching the ON / OFF of the output of the semiconductor laser constituting the seed laser and the amplifier (excitation) laser. When the laser oscillator uses an external modulation element, the ON / OFF of the irradiation of the first laser L1 can be switched rapidly by switching the ON / OFF of the external modulation element (AOM, EOM, etc.) provided outside the resonator.

[0174] Alternatively, the formation and cessation of the modified region can be switched as follows. For example, the optical path of the first laser L1 can be opened and closed by controlling a mechanical mechanism such as a shutter, thereby switching the formation and cessation of the modified region. The first laser L1 can also be switched to CW (continuous wave) light, thereby stopping the formation of the modified region. A pattern can also be displayed on the liquid crystal layer of the reflective spatial light modulator 34, making the focusing state of the first laser L1 a non-modified state (e.g., a pear-skin-like pattern of laser scattering), thereby stopping the formation of the modified region. The power adjustment unit such as an attenuator can also be controlled to reduce the power of the first laser L1 in a way that prevents the formation of the modified region, thereby stopping the formation of the modified region. The polarization direction can also be switched, thereby stopping the formation of the modified region. The first laser L1 can also be scattered (dispersed) in a direction other than the optical axis, thus cutting it off, thereby stopping the formation of the modified region.

[0175] The following describes an example of a method for manufacturing (obtaining) a semiconductor device by performing trimming and stripping processes on an object 100 using a laser processing apparatus 101. The manufacturing method described below refers to the reuse of the removed portions (parts of the object 100 that are not used as semiconductor devices) that are removed from the object 100 by trimming and stripping processes.

[0176] First, the object 100 is placed on the stage 107 with the back side 100b as the laser incident surface. The surface 100a of the object 100, which carries the functional components, is protected by a support substrate or tape.

[0177] Next, finishing and processing will be carried out. Specifically, such as... Figure 11 As shown in (a), while the stage 107 rotates at a certain speed, the first laser L1 of the laser processing head 10A is irradiated with the first focusing point P1 positioned on line M3 of the object 100. The irradiation by the first laser L1 is repeated by changing the Z-direction position of the first focusing point P1. That is, as shown in (a). Figure 10 (b) and Figure 11 As shown in (b), prior to the stripping process, along line M3, a modified region 43 is formed on the opposite side of the laser incident surface, inside the object 100, which is closer to the imaginary surface M1.

[0178] Next, a stripping process is performed. Specifically, such as... Figure 12As shown in (a), while rotating the stage 107 at a certain rotational speed, the first laser L1 is irradiated from the laser processing head 10A, and the first focusing point P1 is moved from the outer edge of the imaginary surface M1 inward along the Y direction, the laser processing head 10A is moved along the Y-axis track 108. Thus, as... Figure 12 (b) and Figure 12 As shown in (c), a rotation axis C is formed along the imaginary surface M1 inside the object 100 (see reference). Figure 9 The modified region 4 extends in a vortex-like (involute curve) shape centered on the location of the point. The resulting modified region 4 contains multiple modified points. Thus, as... Figure 13 As shown in (a), a portion of the object 100 is peeled off, with the modified region 4 covering the imaginary surface M1 and the cracks extending from the modified points of the modified region 4 as boundaries. At the same time, the removal region E is removed, with the modified region 43 along the line M3 and the cracks extending from the modified points of the modified region 43 as boundaries.

[0179] Furthermore, the removal of object 100 and the removal of area E can also be performed, for example, using an adsorption device. The removal of object 100 can be performed on stage 107 or by moving it to a dedicated removal area. The removal of object 100 can be performed using air blow or adhesive tape. When external stress alone is insufficient to remove object 100, an etching solution (KOH or TMAH, etc.) that reacts with object 100 can be used to selectively etch the modified areas 4, 43. In this way, object 100 can be easily removed. Although stage 107 is rotated at a fixed speed, this speed can be varied. For example, the rotation speed of stage 107 can be changed to alter the pitch of the modified points contained in modified area 4 to a fixed interval.

[0180] Next, as Figure 13 As shown in (b), the peeled surface 100h of the object 100 is subjected to fine grinding or polishing using an abrasive such as a grinding stone. This polishing process can be simplified when the object 100 is peeled off by etching. The above results in the acquisition of the semiconductor device 100k.

[0181] Next, the stripping process of this embodiment will be described in more detail.

[0182] like Figure 14 As shown in (a), a line (processing line) M11 is provided on the object 100, which is the object to be stripped. The line M11 is a line that is intended to form the modified region 4. The line M11 extends in a spiral shape from the peripheral side toward the inward side in the object 100. In other words, the line M11 is oriented toward the rotation axis C of the stage 107 (see reference). Figure 9 The position is centered on a spiral (involute) extension. Line M11 is a machining line with multiple parallel lines M11a arranged side by side. For example, one full rotation of the spiral constitutes one parallel line M11a. Although line M11 is a hypothetical line, it can also be an actual drawn line. Line M11 can also be assigned coordinates.

[0183] like Figure 14 (a) and Figure 14 As shown in (b), the object 100 has a beveled portion (peripheral portion) BB, which has a side surface intersecting the laser incident surface, i.e., the back surface 100b. The beveled portion BB is, for example, a chamfered surface used to improve strength. The beveled portion BB is formed by making the corner of the periphery of the object 100 curved (R surface). The beveled portion BB is, for example, the portion of the object 100 from the periphery to an inner side of 200 to 300 μm.

[0184] The object 100 is provided with an alignment object 100n. For example, the alignment object 100n has a certain relationship with the position of the object 100 in the 0° direction in the θ direction (the rotation direction of the stage 107 about the rotation axis C). The position in the 0° direction is the position of the object 100 that serves as a reference in the θ direction. For example, the alignment object 100n is a notch formed on the peripheral side of the object 100. The alignment object 100n is not particularly limited and can be the orientation plane of the object 100 or a pattern of a functional element.

[0185] Control unit 9 performs a first processing procedure on the beveled peripheral portion (first part) 100X, including the beveled portion BB, by irradiating it with the first laser L1 under a first processing condition. After the first processing procedure, control unit 9 performs a second processing procedure on the inner peripheral portion (second part) 100Y of the object 100, which is further inward than the beveled peripheral portion 100X, by irradiating it with the first laser L1 under a second processing condition different from the first processing condition. The first and second processing procedures are included in the stripping process. The sizes of the beveled peripheral portion 100X and the inner peripheral portion 100Y of the object can be input via GUI 111.

[0186] In the first and second processing steps, such as Figure 15 As shown, the first laser L1 is branched by forming a plurality of modified particles SA arranged in a row along an inclined direction C2 that is orthogonal to the extension direction C1 (processing direction) of line M11 on an imaginary surface. The branching of the first laser L1 can be achieved, for example, by using a reflective spatial light modulator 34 (see reference). Figure 5 To achieve this.

[0187] In the example shown in the diagram, the first laser L1 is branched into four points SA. For an adjacent pair of points SA among the four branched points SA, the spacing along the extension direction C1 of line M11 is the branch pitch BPx, and the spacing in the orthogonal direction of the extension direction C1 is the branch pitch BPy. For a pair of points SA formed by irradiation with two consecutive pulses of the first laser L1, the spacing along the extension direction C1 is the pulse pitch PP. The angle between the extension direction C1 and the tilt direction C2 is the branch angle α.

[0188] In the first and second processing steps, the first laser L1 irradiates the object 100, and the position of the first focusing point P1 is moved relative to the object 100 along a spiral line M11 from the periphery toward the inward side, thereby forming a modified region 4 along the line M11. That is, in the first and second processing steps, the region in the object 100 where the modified region 4 is formed is moved along a first direction from the periphery toward the inward side.

[0189] The first and second processing conditions, when the first laser L1 is irradiated along a processing line to form the modified region 4, are conditions that cause the internal processing state of the object 100 (hereinafter also referred to as the "processing state") to become the partially cut state (first cutting state) described later. The first and second processing conditions, when the first laser L1 is irradiated along a processing line having multiple parallel lines arranged side by side, i.e., line M11, to form the modified region 4, are conditions that cause the processing state to become the fully cut state (second cutting state) described later.

[0190] The first processing condition is the condition that makes the processed state after laser processing with a first specified amount reach a state of complete cutting. The second processing condition is the condition that makes the processed state after laser processing with a second specified amount, greater than the first specified amount, reach a state of complete cutting. Specific parameters for the first and second processing conditions can be listed as follows: the number of branches of the first laser L1, the branch pitches BPy and BPx, the pulse energy, the pulse pitch and pulse width, and the processing speed, etc. The processing condition that makes the processed state reach a state of partial cutting is the processing condition after the parameters are appropriately set according to known techniques to achieve this state. The processing condition that makes the processed state reach a state of complete cutting is the processing condition after the parameters are appropriately set according to known techniques to achieve this state. For example, in the first processing condition, the number of branches is 4, the branch pitch BPy is 20 μm, the branch pitch BPx is 30 μm, the pulse energy is 16.73 μJ, the processing speed is 800 mm / s, the pulse pitch is 10 μm, and the pulse width is 700 ns. For example, under the second processing condition, except that the branch pitch BPy is 30μm, it is the same as the first processing condition.

[0191] The processing conditions discovered during the stripping process are described below.

[0192] Figure 16 (a) and Figure 17 (a) is an image showing the hidden cut. Figure 16 (b) and Figure 17 (b) is an image showing the partially cut state. Figure 18 (a) An image showing the processing state after laser processing of the first specified amount, i.e., the state of complete cutting. Figure 18 (b) An image showing the processing state after laser processing of the second specified quantity, i.e., the state of complete cutting.

[0193] Figure 16 (a)~ Figure 18 (b) is an image of the position of the imaginary surface M1 taken by the camera unit IR from the laser incident surface. Figure 16 (a) and Figure 16 (b) The processing state in which the first laser L1 is irradiated along a processing line (parallel line) to form the modified region 4. Figure 17 (a)~ Figure 18 (b) shows the processing state where the first laser L1 is irradiated along multiple processing lines to form the modified region 4. The processing lines are set to extend in a straight line to the left and right in the diagram. Figure 16 (a)~ Figure 18 As shown in (b), the processing state changes in three stages depending on the pulse energy and branch pitch.

[0194] like Figure 16 (a) and Figure 17 As shown in (a), the concealed cut (SST) state refers to a state where the cracks at the multiple modified points (scratches) SA contained in the modified region 4 have not extended or are not connected. The concealed cut state is a state in which only the modified points SA can be observed. In the concealed cut state, because the cracks have not extended, even if the number of processing wires is increased, it is impossible to change the state to a state of complete cut.

[0195] like Figure 16 (b) and Figure 17As shown in (b), the semi-cut (SHC) state refers to a state in which cracks extending from the multiple modified points SA contained in the modified region 4 extend in the direction along the processing line. In the image, the modified points SA and stains along the processing line can be identified in the semi-cut state. By increasing the number of processing lines to make the processing state a semi-cut state, it can be changed to a fully cut state, but the number of processing lines that change to a fully cut state will vary depending on the processing conditions. Furthermore, in order to produce a fully cut state, the semi-cut state is indispensable as a processing state in which the modified region 4 is formed by irradiating the first laser L1 along a processing line.

[0196] The fully cut (SFC) state refers to a state where cracks extending from multiple modification points SA within modification region 4 extend and connect along multiple processing lines and in directions intersecting with the processing lines. The fully cut state also refers to a state where cracks extending from modification points SA extend horizontally, vertically, and horizontally across multiple processing lines in the image and are connected. For example... Figure 18 (a) and Figure 18 As shown in (b), the state of complete cut is a state in which the modified point SA on the image cannot be identified (the state in which the space or gap formed by the crack is identified). The state of complete cut is a state caused by the connection of cracks across multiple processing lines, and it is impossible to form the modified region 4 by irradiating the first laser L1 along a processing line.

[0197] The complete cutting state includes: the first complete cutting state and the second complete cutting state. The first complete cutting state is the complete cutting state produced after the first specified amount of laser processing (refer to...). Figure 18 (a)). The second completely cut-off state is the completely cut-off state produced after laser processing with a second specified amount greater than the first specified amount (see reference). Figure 18 (a)).

[0198] The first specified amount of laser processing refers to, for example, the case where a first laser L1 is irradiated along multiple parallel lines less than 100 to form the modified region 4. The first specified amount of laser processing also refers to, for example, the case where the width of the region forming the modified region 4 in the object 100 in the index direction is less than 12 mm. The index direction is a direction orthogonal to the extension direction of the processing lines when viewed from the laser incident surface. The second specified amount of laser processing refers to, for example, the case where a first laser L1 is irradiated along multiple processing lines more than 100 to form the modified region 4. The second specified amount of laser processing also refers to, for example, the case where the width of the region forming the modified region 4 in the object 100 in the index direction is 12 mm or more. The first and second specified amounts are not particularly limited and can be various parameter values. The first and second specified amounts can also be, for example, processing time. The first and second specified amounts can also be a combination of multiple parameter values.

[0199] in addition, Figure 16 (a)~ Figure 18 (b) Although the image is captured by the IR camera unit, it can also be obtained using a typical IR camera. Figure 16 (a)~ Figure 18 (b) The same image. Figure 16 (a)~ Figure 18 (b) As a result, there are no particular limitations on the shape and size of the object 100. Even if the object 100 is a hole wafer or a small wafer, it is still possible to obtain the same... Figure 16 (a)~ Figure 18 (b) The same result. Figure 16 (a)~ Figure 18 (b) is the result of laser processing only (the result of processing without applying stress). Even if the modified region 4 is formed by irradiating the first laser L1 along multiple processing lines less than 100, there are still cases where the object 100 is completely cut off by applying stress.

[0200] Control unit 9 sets the first processing condition and the second processing condition based on user input via GUI 111. The display and input of GUI 111 will be described later. Control unit 9 displays the imaging results from the camera unit IR, i.e., the processing status of the interior of the object 100, on GUI 111.

[0201] The camera unit IR monitors whether the processing state of the modified region 4 formed along the spiral line M11 is in a partially cut state. In the first processing step, the camera unit IR monitors whether the processing state after a first predetermined amount of laser processing is in a fully cut state (i.e., whether it is in the first fully cut state). In the second processing step, the camera unit IR monitors whether the processing state after a second predetermined amount of laser processing is in a fully cut state (i.e., whether it is in the second fully cut state). State monitoring includes: performing the function of monitoring the state and / or obtaining information that can determine the state (e.g., acquiring an image).

[0202] The control unit 9 determines, based on the monitoring results of the camera unit IR, whether the processing state after the first predetermined amount of laser processing in the first processing step is a state of complete cutting of the second cut, and whether the processing state after the second predetermined amount of laser processing in the second processing step is a state of complete cutting of the second cut. The determination of the processing state can be performed using various known image processing methods. The determination of the processing state can also be performed using a pre-trained model obtained through deep learning (AI, artificial intelligence). Other determinations made by the control unit 9 are the same.

[0203] Next, regarding the above-mentioned stripping process, refer to Figure 19 The flowchart is explained in detail.

[0204] In this embodiment, the peeling process involves performing a second processing step after the cracks reach the beveled surface BB using the first processing step, thereby peeling off the object 100. Specifically, the following processes are performed by controlling each part of the laser processing apparatus 101 via the control unit 9.

[0205] First, with the alignment camera AC positioned directly above the alignment object 100n of the object 100 and focused on the alignment object 100n, the stage 107 is rotated and the laser processing head 10A is moved along the Y-axis track 108 and the first Z-axis track 106A. An image is captured by the alignment camera AC. Based on the image captured by the alignment camera AC, the position of the object 100 in the 0-degree direction is obtained. Furthermore, based on the image captured by the alignment camera AC, the diameter of the object 100 is obtained. Alternatively, the diameter of the object 100 can also be set via user input.

[0206] Next, as Figure 9 and Figure 20As shown in (a), the stage 107 is rotated so that the object 100 is positioned at 0 degrees. The laser processing head 10A is moved along the Y-axis track 108 such that the first focusing point P1 is positioned at the predetermined peeling start position in the Y direction. The laser processing head 10A is moved along the first Z-axis track 106A such that the first focusing point P1 is positioned at the imaginary surface M1 in the Z direction. For example, the predetermined peeling start position is a predetermined position further away from the object 100.

[0207] Next, the rotation of the stage 107 begins. Tracking using the back surface 100b of the range sensor begins. Before the range sensor begins tracking, it is confirmed that the position of the first focusing point P1 is within the range of the range sensor. When the rotational speed of the stage 107 reaches a constant speed, irradiation with the first laser L1 from the laser processing head 10A begins.

[0208] While irradiating the peripheral portion 100X of the inclined surface with the first laser L1 under the first processing conditions, the laser processing head 10A is moved along the Y-axis track 108 by moving the first focusing point P1 inward along the Y direction (step S1, first processing step). In step S1, the area in the object 100 where the modified region 4 is formed is moved along the first direction E1 from the periphery inward. In step S1, laser processing is performed with the index direction set to the first direction E1. In step S1, the modified region 4 is formed by moving the first focusing point P1 along the spiral line M11 from the periphery inward. In step S1, the irradiation of the first laser L1 can begin when the optical axis of the first laser L1 is still outside the object 100 or when it is located at the peripheral portion 100X of the inclined surface.

[0209] After the first processing step of the first predetermined quantity is completed, the rotation of the stage 107 and the irradiation of the first laser L1 are stopped, and the first processing step is stopped. Based on the imaging results of the imaging unit IR, it is determined whether the processing state after the first predetermined quantity of processing is a completely cut state (step S2). If the above step S2 is yes, the rotation of the stage 107 and the irradiation of the first laser L1 are restarted, and the first processing step is restarted (step S3). In this way, the modified region 4 is formed along the spiral line M11 at the periphery 100X of the inclined surface, so that the processing state is a completely cut state (see reference). Figure 20 (b)).

[0210] Next, as Figure 9 and Figure 21As shown in (a), while the stage 107 is rotated, the laser processing head 10A moves along the Y-axis track 108 while irradiating the inner periphery 100Y with the first laser L1 under the second processing condition, and the first focusing point P1 moves inward along the Y direction towards the inner periphery (step S4, second processing step). In step S4, the index direction is set to the first direction E1 for laser processing. In step S4, the first focusing point P1 is moved along the spiral line M11 from the periphery towards the inner side to form the modified region 4.

[0211] After the second processing step of the second specified quantity, the rotation of the stage 107 and the irradiation of the first laser L1 are stopped, and the second processing step is stopped. Based on the imaging results of the imaging unit IR, it is determined whether the processing state after the second specified quantity of processing is a completely cut state (step S5). If step S5 is yes, the rotation of the stage 107 and the irradiation of the first laser L1 are restarted, and the second processing step is restarted (step S6). In this way, the modified region 4 is formed along the spiral line M11 in the inner peripheral portion 100Y, so that the processing state is a completely cut state (see reference). Figure 21 (b)).

[0212] Through the above actions, the modified region 4 is formed along line M11 over the entire area of ​​the imaginary surface M1, thus completing the processing (step S7). Based on the imaging results of the imaging unit IR, it is determined whether the processed state after processing is a completely cut state over the entire area of ​​the imaginary surface M1 (step S8). If step S8 is yes, the peeling process is considered to have been completed normally, and the processing ends normally. On the other hand, if step S2 is no, step S5 is no, or step S8 is no, it is determined that an error has occurred in the processing state, and for example, the error in the processing state is reported via GUI 111 (step S9). For example, after step S9, the first processing condition and the second processing condition are reset through another process (for example, the process of the fourth embodiment described later).

[0213] Additionally, if the width of the beveled perimeter 100X in the index direction is less than 35mm, warping of the beveled surface BB may occur during the second processing step. If the width of the beveled perimeter 100X in the index direction is greater than 35mm, warping of the beveled surface BB may occur during the first processing step.

[0214] Figure 22 This is a top view used to illustrate the cracked object 100 extending from the modified region 4 formed along the imaginary surface M1. Figure 23 show Figure 22The observation results of cracking on object 100. Figure 22 This shows the state of the object 100 as observed from the laser incident surface. In this experiment, in the object 100, a modified region 4 is formed along multiple parallel straight processing lines in the outer peripheral portion 100G and the inner peripheral portion 100F. Furthermore, the number of processing lines is varied to observe cracks on the rear side (outer peripheral portion 100G side) of the inner peripheral portion 100F in the index direction, cracks on the front side of the inner peripheral portion 100F in the index direction, and cracks on the front side of the outer peripheral portion 100G in the index direction.

[0215] In the figure, the left and right directions are the scanning directions (the extension direction of the processing lines), and the up and down directions are the index directions. The first laser L1 has 4 branches, a branch pitch BPy of 20 μm, a branch pitch BPx of 30 μm, a pulse energy of 16.73 μJ, a processing speed of 800 mm / s, a pulse pitch of 10 μm, and a pulse width of 700 ns. Object 100 is a silicon wafer with the (100) plane as its main surface. The thickness of object 100 is 775 μm.

[0216] like Figure 22 and Figure 23 As shown, the amount of crack extension varies greatly in the direction preceding the index direction and does not depend on the number of processing lines. In the direction following the index direction, the amount of crack extension increases with the increase of the number of processing lines. It is known that the crack extends in the direction opposite to the index direction (behind the index direction). It is known that the amount of crack extension depends on the number of processing lines. That is, it was found that when the modified region 4 is formed along the imaginary surface M1, the migration direction (index direction) of the region forming the modified region 4 in the object 100 greatly contributes to the direction of crack extension from the modified region 4 along the imaginary surface M1. Specifically, it was found that crack extension is easily and stably achieved in the direction opposite to this migration direction.

[0217] Furthermore, using processing condition I, a wafer with a beveled surface (BB) was laser-processed in a manner where the processing state was a fully cut state. The experimental results are shown below. The width of the modified region is its width in the index direction. "×" represents No Good, "△" represents Good, and "○" represents Very Good.

[0218] <Processing Conditions I>

[0219] Number of branches: 4; Branch pitch: BPy: 20μm; Branch pitch: BPx: 30μm; Machining speed: 800mm; Frequency: 80kHz

[0220] <Experimental Results>

[0221] Modified zone width 10mm (processing lines 500): Cracks reach the bevel surface BB×

[0222] The width of the modified zone is 20mm (1000 processing lines): cracks reach the bevel surface BB×

[0223] The width of the modified zone is 25mm (1252 processing lines): cracks reach the bevel surface BB×

[0224] The width of the modified zone is 30mm (1500 processing lines): cracks reach the beveled surface BB△

[0225] The width of the modified zone is 35mm (1752 processing lines): cracks reach the bevel surface BB○ (warpage 0.3mm).

[0226] Furthermore, processing condition II was used to laser process a wafer with a beveled BB portion in a semi-cut state. The experimental results are shown below. The width of the modified region is its width in the index direction. "×" represents No Good, "△" represents Good, and "○" represents Very Good.

[0227] <Processing Conditions II>

[0228] Number of branches: 4; Branch pitch: BPy: 30μm; Branch pitch: BPx: 30μm; Machining speed: 800mm; Frequency: 80kHz

[0229] <Experimental Results>

[0230] The width of the modified zone is 10mm (333 processing lines): cracks reach the bevel surface BB×

[0231] The width of the modified zone is 20mm (666 processing lines): cracks reach the bevel surface BB×

[0232] The width of the modified zone is 25mm (833 processing lines): cracks reach the bevel surface BB×

[0233] The width of the modified zone is 30mm (1000 processing lines): cracks reach the bevel surface BB×

[0234] The width of the modified zone is 100mm (number of processing lines is 3333): cracks reach the bevel surface BB×

[0235] Based on these experimental results, it can be seen that when the processing state of the modified zone is a complete cut, the crack can reach the bevel surface BB. When the processing state of the modified zone is a partial cut, the crack is difficult to reach the bevel surface BB. That is, in order for the crack to extend at the bevel surface BB, the processing state of the modified zone must at least be a complete cut.

[0236] In the laser processing apparatus 101 and laser processing method described above, the region forming the modified region 4 in the peripheral portion 100X of the inclined surface is moved along a first direction E1 from the periphery toward the inward side. That is, the index direction of the first laser L1 is set to the first direction E1. In this way, it is easier to stably extend the crack along the direction opposite to the first direction E1, that is, from the inward side toward the periphery. It is easier to stably extend the crack along the direction opposite to the first direction E1 in the modified region 4, that is, from the inward side toward the periphery. As a result, the crack can still be formed even in the difficult-to-process inclined surface BB, and the object 100 can be reliably peeled off. Furthermore, in the inner peripheral portion 100Y, which is further inward than the peripheral portion 100X of the inclined surface, laser processing can be performed with the desired processing conditions set as the second processing conditions, thereby realizing laser processing that meets various needs such as shortening production time.

[0237] In the first processing step of the laser processing apparatus 101 and the first processing step of the laser processing method, a modified region 4 is formed from the periphery to the inside along a spiral line M11 extending from the periphery to the inside in the object 100, or multiple modified regions 4 are sequentially formed from the periphery to the inside along multiple parallel straight lines arranged in the direction from the periphery to the inside in the object 100. Specifically, this can be achieved by migrating the region where the modified region 4 is formed in the peripheral portion 100X of the inclined surface including the inclined surface BB along the first direction E1 from the periphery to the inside.

[0238] In the first and second processing conditions of the laser processing apparatus 101 and the laser processing method, when a modified region is formed by irradiating a laser along a processing line, the processing state becomes a cutting / semi-cutting state. Based on such processing conditions, the object 100 can be reliably peeled off.

[0239] In the first and second processing conditions of the laser processing apparatus 101 and the laser processing method, when the first laser L1 is irradiated along a processing line having multiple parallel lines (a spiral line M11 and multiple straight lines) to form a modified region 4, the processing state is such that the cutting is completely severed. Based on such processing conditions, the object 100 can be reliably peeled off.

[0240] In the first processing condition of the laser processing apparatus 101 and the laser processing method, the processed state after a first predetermined amount of laser processing becomes a state of complete cutting. The second processing condition is a condition where the processed state after a second predetermined amount of laser processing, exceeding the first predetermined amount, becomes a state of complete cutting. In this case, according to the second processing condition, compared to the first processing condition, the multiple modified points SA contained in the formed modified region 4 become larger, allowing for more efficient laser processing. Thus, laser processing with reduced production time can be achieved.

[0241] In the laser processing apparatus 101 and laser processing method, a finishing process (finishing process) is performed before the stripping process (stripping treatment). This finishing process involves forming a modified region 43 on the part of the object 100 that is closer to the surface 100a than the imaginary surface M1, along a line M3 that extends in a ring shape on the inner side of the periphery of the object 100. This finishing process removes the periphery of the line M3. Because the finishing process can be performed before stripping the object 100, it is possible to avoid irradiating the first laser L1 with cracks caused by stripping, compared to performing the finishing process after stripping. Furthermore, the removed portion from the object 100 by the finishing process and the stripping process is reusable.

[0242] In the second processing step of the laser processing apparatus 101 and the second processing method, the region in the object 100 where the modified region 4 is formed is moved along the first direction E1. That is, the index direction of the first laser L1 in the second processing step or the second processing method is set to the first direction E1. In this way, the object 100 can be reliably peeled off.

[0243] As mentioned above, it has been found that if the processing state in which the modified region 4 is formed along a processing line having multiple parallel lines is not a complete cut, it is difficult to peel off the object 100. Therefore, in the laser processing apparatus 101 and the laser processing method, it is monitored whether the processing state in which the modified region 4 is formed along line M11 is a complete cut. Based on the monitoring results, it can be easily determined whether the object 100 can be peeled off.

[0244] In the laser processing apparatus 101 and laser processing method, in the first processing step (first processing procedure), the processing state after a first predetermined amount of laser processing is monitored to ensure that the cut is completely severed. In the second processing step (second processing procedure), the processing state after a second predetermined amount of laser processing is monitored to ensure that the cut is completely severed. Thus, it is easy to determine whether the object 100 can be peeled off through the first processing step (first processing procedure). It is also easy to determine whether the object 100 can be peeled off through the second processing step (second processing procedure).

[0245] In the laser processing apparatus 101, the control unit 9 determines, based on the monitoring results of the camera unit IR, whether the processing state after the first predetermined amount of laser processing in the first processing is a completely cut state, and whether the processing state after the second predetermined amount of laser processing in the second processing is a completely cut state. In this case, the control unit 9 can automatically determine whether the processing state is a completely cut state based on the monitoring results.

[0246] In the laser processing apparatus 101 and the laser processing method, it is further monitored whether the processing state after processing is a completely cut state. In this way, it can be determined whether the object 100 can be peeled off after processing. In addition, the above-mentioned step S8 and related processes for determining whether the processing state after processing is a completely cut state can be omitted.

[0247] Incidentally, in this embodiment, the camera unit IR can also monitor whether the processing state when the modified region 4 is formed along a processing line is in a cutting / partial-cut state. For example, when the processing line includes multiple lines, the processing state when the modified region 4 is formed along any one of the lines can be monitored. Additionally, for example, if the processing line is a spiral-shaped line M11, the processing state when the modified region 4 is formed along a portion of that spiral can be monitored.

[0248] In this situation, the control unit 9 can determine whether the processing state of forming the modified region 4 along a processing line is a half-cut state based on the monitoring results of the camera unit IR. Thus, the processing state can be automatically determined based on the monitoring results. If the processing state of forming the modified region 4 along a processing line is not a half-cut state (but a partially cut state), it is determined that an error has occurred in the processing state. For example, the error in the processing state is reported via GUI 111, and the processing conditions are reset.

[0249] In this embodiment, the first processing (first processing method) is performed on the peripheral portion 100X of the inclined surface, and the second processing (second processing) is performed on the inner peripheral portion 100Y. However, the second processing (second processing) may be omitted, and the first processing (first processing) may be performed on the entire area of ​​the object 100.

[0250] In the second processing step (second processing step) of this embodiment, such as Figure 24 (a) and Figure 24As shown in (b), the region forming the modified region 4 can also be moved along the second direction E2. Specifically, the index direction is set to the first direction E1, and laser processing is performed on the peripheral portion 100X of the inclined surface. In the peripheral portion 100X of the inclined surface, the modified region 4 is formed along the line M11 in a manner from the outer edge of the spiral shape toward the inner periphery. Then, the index direction is set to the second direction E2, and laser processing is performed on the inner periphery 100Y. In the inner periphery 100Y, the modified region 4 is formed along the line M11 in a manner from the inner periphery of the spiral shape toward the outer edge.

[0251] Therefore, even when the pointer direction of the first laser L1 in the second processing step (second processing step) is set to the second direction E2, the object 100 can still be reliably peeled off. Furthermore, in this case, the distance of the beveled periphery 100X in the pointer direction can be less than a predetermined distance. This predetermined distance is, for example, less than 35 mm, specifically 20 mm. In this way, peeling can be performed without causing cracks in the object 100.

[0252] In this embodiment, the order of the first processing step (first processing step) and the second processing step (second processing step) may be interchanged, and the first processing step may be performed after the second processing step. In this case, although cracks may easily occur during the processing of the beveled periphery 100X, at least the beveled periphery 100X is peelable. In this embodiment, as long as the index direction of the first processing step is the first direction E1, other processing conditions (the order of the first and second processing steps, and the processing state of the first and second processing steps, etc.) are not particularly limited. As long as the processing conditions described above are met, the object 100 can be reliably peeled off.

[0253] In the laser processing apparatus 101 and the laser processing method, input from the user can be received by the GUI 111, and the control unit 9 can set at least one of the first processing conditions and the second processing conditions based on the input from the GUI 111. The first processing conditions and the second processing conditions can be set as desired. The following is an example of the setting screen displayed on the GUI 111.

[0254] Figure 25 This is an example of the GUI111 settings screen. Figure 25 The settings screen shown is for use during mass production or when the user makes decisions about processing conditions. Figure 25The setup screen shown includes: a machining method selection button 201 for choosing from multiple machining methods; an input field 202 for setting the size of the bevel perimeter 100X; an input field 203 for setting the size of the inner perimeter 100Y; and a detail button 204 for navigating to detailed settings. The multiple machining methods differ depending on the direction of the first machining process, the direction of the second machining process, and the presence or absence of the second machining process. The input field 202a for the case without the second machining process (i.e., when performing full machining using the first machining process) contains all available options.

[0255] Figure 26 Other examples of displaying the GUI111 settings screen. Figure 26 The setup screen shown is, for example, when the user touches the details button 204 (see reference). Figure 25 The screen shows the detailed settings for the situation. Figure 26 The setup screen shown includes: a processing condition selection button 211 for selecting processing conditions; a branch number field 212 for inputting or selecting the number of branches of the first laser L1; an index field 213 for inputting the distance to move from one processing line to the next processing line after laser processing; a schematic diagram for inputting or displaying the number of branches and indexes; a processing Z height field 215 for inputting the position of the modified particle SA in the Z direction; a processing speed field 216 for inputting the processing speed; and a condition switching method button 217 for selecting the method to switch processing conditions.

[0256] The processing condition selection button 211 allows you to select whether to set the first or second processing condition. Based on the indicator bar 213, when the number of branches is 1, the laser processing head 10A automatically moves in the indicated direction by an amount corresponding to its input value. When the number of branches is greater than 1, the laser processing head 10A automatically moves in the indicated direction according to the following calculation formula.

[0257] Indicator = (Number of branches) × Indicator input value

[0258] Schematic diagram 214 includes: a display unit 214a for the index input value, and a power input field 214b for inputting the power of each modified particle SA. The processing speed field 216, since the actual platform 107 rotates, can be the rotational speed. The processing speed field 216 can also automatically convert the input processing speed to rotational speed. The condition switching method button 217 allows selection: automatically continuing the second processing step after the first processing step is completed, or stopping the device briefly after the first processing step is completed to perform status monitoring, and then continuing the first processing step.

[0259] Figure 27 This is an example of the administrator mode of the GUI111 settings screen. Figure 27The setup screen shown includes: a branch direction selection button 221 for selecting the branch direction of the first laser L1; a branch number field 222 for inputting or selecting the number of branches of the first laser L1; a branch pitch input field 223 for inputting the branch pitch BPx; a branch pitch column input field 224 for inputting the number of columns of the branch pitch BPx; a branch pitch input field 225 for inputting the branch pitch BPy; an index field 226 for inputting the index; a schematic diagram of the optical axis based on the number of branches 227; a forward / backward selection button 228 for selecting the scanning direction of the first laser L1 as one direction (outward) or another direction (backward); and a balance adjustment start button 229 for automatically adjusting the balance of various values.

[0260] At the point when the number of branches and the branch pitches BPx and BPy are input, the distance to the optical axis is automatically calculated. The calculated value is based on the imaging optical system 35 (reference). Figure 5 If the relationship between the branches is incorrect, the GUI 111 will display the relevant information. To perform this calculation, information related to the imaging optical system 35 can be entered. When the branch direction selection button 221 is set to vertical, multiple branch pitches 227a in the optical axis diagram 227 can be set to not be displayed. The number of branches can also be adjusted by increasing or decreasing the number of squares in the branch pitches 227a and 227b in the optical axis diagram 227. In the optical axis diagram 227, although the input values ​​are obtained from the branch pitch column number input field 224 and the branch pitch input field 225, checking the boxes in each checkbox CK will change the distance of the branch pitches 227a and 227b corresponding to the checked checkbox CK.

[0261] Figure 28 An example of a survey showing the optimal pulse energy for peeling processing. Figure 28 The diagram shows the processing status when laser processing is performed along a single processing line, and the feasibility of peeling after laser processing along multiple processing lines (parallel lines). The first laser, L1, has 4 branches, with branch pitches BPx and BPy both at 30 μm, a processing speed of 800 mm / s, a pulse pitch of 10 μm, and a pulse width of 700 ns. "SST" in the diagram indicates a concealed cutting state. "SHC" indicates a partially cut state. Figure 28 As shown, the optimal pulse energy for producing a semi-cut state is in the range of 9.08–56 μJ. Furthermore, it is evident that stripping can be performed without problems, particularly within the pulse energy range of 12.97–25 μJ. Additionally, when the pulse pitch is greater than 10 μm, the optimal pulse energy tends to be higher than the experimental results shown in the figure. When the pulse pitch is less than 10 μm, the optimal pulse energy tends to be lower than the experimental results shown in the figure.

[0262] In this embodiment, although the processing state is automatically determined by the control unit 9, the user can also determine the processing state based on the monitoring results of the camera unit IR. The determination that the processing state is in the state of complete cutting is equivalent to the determination that the processing state is not in the state of partial cutting or the state of concealed cutting.

[0263] In typical peeling processes, the pitch of multiple modified points SA contained in the modified region 4 to be formed narrows, and the modified points SA are arranged to fill the imaginary surface M1, which serves as the predetermined peeling surface, before peeling off the object 100. In this case, the processing conditions are chosen to minimize the propagation of cracks from the modified points SA (e.g., a short wavelength laser (1028 nm), a pulse width of 50 nm, and a pulse pitch of 1–10 μm (particularly 1.5–3.5 μm)). In contrast, in this embodiment, the processing conditions are chosen to allow cracks to propagate along the imaginary surface M1. For example, the processing conditions for the first laser L1 used to form the modified region 4 along the imaginary surface M1 are: a long wavelength laser L1 (e.g., 1099 nm) and a pulse width of 700 nm. As a result, new processing states (partial cutting and complete cutting, etc.) are discovered.

[0264] In this embodiment, the control unit 9 may also perform a third processing step during the first processing step. This third processing step involves irradiating the beveled periphery 100X with the first laser L1 under processing conditions different from the first processing conditions. In other words, the third processing step may also be performed during the first processing step, whereby the beveled periphery 100X is irradiated with the first laser L1 under processing conditions different from the first processing conditions. These other processing conditions are not particularly limited and can be various. For example, these other processing conditions could be those that cause the internal processing state of the object 100 to be a partially cut, partially cut, or completely cut state. In this case, the object 100 can be reliably peeled off. The spacing of the index directions of the processing lines in the third processing step (third processing step) may be wider than the spacing of the index directions of the processing lines in the first processing step (first processing step).

[0265] In this embodiment, when switching between the first processing step (first processing step) and the second processing step (second processing step), processing can be stopped once before switching, or processing can be switched without stopping. In this embodiment, when switching between the first processing step (first processing step) and the third processing step (third processing step), processing can be stopped once before switching, or processing can be switched without stopping. When switching processing steps without stopping processing, the processing conditions can be switched smoothly. For example, when the difference between the first processing condition and the second processing condition is only the branch pitch BPy, when the branch pitch BPy changes from 20μm to 30μm, instead of stopping processing before switching, the branch pitch BPy can be changed gradually (in the order of 20μm, 21μm, 22μm, 23μm...30μm) without stopping the rotation of the stage 107.

[0266] [Second Implementation]

[0267] The second embodiment will now be described. The description of the second embodiment will focus on the differences from the first embodiment, while details repeated in the first embodiment will be omitted.

[0268] In the first embodiment described above, the peeling process is achieved using the first and second processing steps. In contrast, in this embodiment, the peeling process is achieved using only one processing step. That is, as... Figure 29 (a) and Figure 29 As shown in (b), in this embodiment, the difference from the first embodiment described above is that the entire area of ​​the object 100, including the inclined peripheral portion 100X and the inner peripheral portion 100Y, is laser-processed under one processing condition.

[0269] The control unit 9 performs processing on the entire area of ​​the object 100 by irradiating the first laser L1 under the second processing conditions. Specifically, the first laser L1 is irradiated onto the object 100 under the second processing conditions, and the position of the first focusing point P1 is moved relative to the object 100 along a spiral line M11 from the periphery toward the inward side, thereby forming a modified region 4 along the line M11. That is, the region in the object 100 where the modified region 4 is formed is moved along a first direction E1 from the periphery toward the inward side.

[0270] The control unit 9 is a suction device used to adsorb the laser-processed object 100, which rotates in a twisting manner around the Z direction. In this way, external stress can be applied to the object 100 in a way that peels it off.

[0271] Next, regarding the stripping process of this embodiment, refer to... Figure 30 The flowchart is explained in detail.

[0272] In this embodiment, the peeling process is performed by controlling each part of the laser processing apparatus 101 through the control unit 9, and the following processes are carried out. That is, the rotation of the stage 107 is started. While irradiating the object 100 with the first laser L1 under the second processing conditions, the laser processing head 10A is moved along the Y-axis track 108 in such a way that the first focusing point P1 is moved inward along the Y direction (step S11, processing step).

[0273] In step S11 above, the index direction is set to the first direction E1 for laser processing. In step S11 above, the first focusing point P1 is moved along the spiral line M11 from the periphery to the inward side to form the modified region 4. In step S11 above, the starting point for irradiation by the first laser L1 can be when the optical axis of the first laser L1 is still outside the object 100, or when it is located at the periphery 100X of the inclined surface.

[0274] After the second predetermined amount of processing is completed, the rotation of the stage 107 and the irradiation of the first laser L1 are stopped, and the processing step is stopped. Based on the imaging results of the imaging unit IR, it is determined whether the processing state after the second predetermined amount of processing is a completely cut state (i.e., whether it is a second completely cut state) (step S12). If the above step S12 is yes, the rotation of the stage 107 and the irradiation of the first laser L1 are restarted, and the processing step is restarted (step S13). In this way, on the object 100, the modified region 4 is formed along the spiral line M11, and the processing state is a completely cut state (see reference). Figure 29 (b) Through the above actions, the modified region 4 is formed along line M11 in the entire area of ​​the imaginary surface M1, thus completing the processing (step S14).

[0275] Based on the imaging results of the imaging unit IR, it is determined whether the processed state after processing is a complete cut across the entire area of ​​the imaginary surface M1 (step S15). If step S15 is yes, stress is applied to peel off a portion of the object 100 (step S16). In step S16, for example, an adsorption device used to adsorb the object 100 is twisted around the Z direction, thereby applying external stress to the object 100. Then, the process is considered to have been completed normally, and the process ends normally. On the other hand, if step S12 is no or step S15 is no, it is determined that an error has occurred in the processing state, and for example, the error in the processing state is reported via GUI 111 (step S17). For example, after step S17, the second processing conditions are reset through another process (for example, the process of the fourth embodiment described later).

[0276] In the laser processing apparatus 101 and laser processing method of this embodiment, the same effects as in the first embodiment can be achieved. The laser processing apparatus 101 and laser processing method of this embodiment, by simply achieving a completely cut-off state through laser processing, can peel off the object 100 by applying stress.

[0277] Alternatively, in this embodiment, the condition for making the processing state a half-cut state can be set as the processing condition. Furthermore, the condition for making the processing state a first fully cut state can also be set as the processing condition. In the processing condition for making the processing state a first fully cut state, the above-described step S16 of applying stress can be omitted.

[0278] In this embodiment, there are no particular limitations on the method or structure of applying stress. For example, physical stress (adsorption, pressurization, or water pressure, etc.) can be applied to cause the cracks to extend and peel off. Alternatively, stress can be applied, for example, by laser preheating or ultrasound, to cause the cracks to extend and peel off.

[0279] Figure 31 This is a flowchart illustrating the peeling process of a modified example of the second embodiment. In the modified example, peeling is performed by laser processing and applying stress to achieve a completely severed cutting state. In the modified example, instead of... Figure 30 The process shown is implemented. Figure 31 The following processes are shown. Specifically, the stage 107 is rotated, and while the first laser L1 is irradiated onto the object 100 under the third processing condition, the laser processing head 10A is moved along the Y-axis track 108 in such a way that the first focusing point P1 moves inward along the Y direction (step S21). The third processing condition, when the first laser L1 is irradiated along a processing line to form the modified region 4, is a condition that the processing state is a partially cut state; when the first laser L1 is irradiated along a processing line having multiple parallel lines arranged side-by-side to form the modified region 4, the processing state is a condition that the processing state does not become a completely cut state. This third processing condition is configured by appropriately setting various parameters according to known techniques to ensure that the processing state is a partially cut state and does not become a completely cut state. Thus, the modified region 4 is formed along line M11 over the entire area of ​​the imaginary surface M1, and the processing is completed (step S22). Stress is applied to the object 100 in a manner that makes the processing state a state of complete cutting (step S23).

[0280] Based on the imaging results from the camera unit IR, it is determined whether the processed state after processing is a complete cut across the entire area of ​​the imaginary surface M1 (step S24). If step S24 is yes, the peeling process is considered to have been completed normally, and the process ends normally. On the other hand, if step S24 is no, it is determined that an error has occurred in the processing state, and for example, the error in the processing state is reported via GUI111 (step S25). In this modified example of the laser processing apparatus and laser processing method, the same effect as described above can be achieved.

[0281] [Third Implementation]

[0282] The third embodiment will now be described. The description of the third embodiment will focus on the differences from the first embodiment, while details repeated in the first embodiment will be omitted.

[0283] In the peeling process of this embodiment, the ranging sensor 36 of the laser processing head 10A (refer to...) Figure 9 The warping of the beveled surface BB is monitored by detecting the height (displacement) of the beveled surface BB. In this embodiment, the peeling process is performed by controlling each part of the laser processing apparatus 101 via the control unit 9. Figure 32 The following processes are shown.

[0284] The stage 107 begins to rotate. While irradiating the peripheral portion 100X of the inclined surface with the first laser L1 under the first processing condition, the laser processing head 10A is moved along the Y-axis track 108 by moving the first focusing point P1 inward along the Y direction (step S31). While irradiating the inner peripheral portion 100Y with the first laser L1 under either the first or second processing condition, the laser processing head 10A is moved along the Y-axis track 108 by moving the first focusing point P1 inward along the Y direction (step S32). In steps S31 and S32, the modified region 4 is formed by moving the first focusing point P1 along the spiral line M11 from the periphery inward.

[0285] The rotation of the stage 107 and the irradiation of the first laser L1 are stopped, and the laser processing of the inner circumference 100Y is stopped. Based on the detection result of the distance sensor 36, it is determined whether warping has occurred on the inclined surface BB (step S33). In step S33, if the height of the inclined surface BB detected by the distance sensor 36 is above a predetermined height, it is determined that warping has occurred on the inclined surface BB.

[0286] If step S33 is true, the rotation of the stage 107 and the irradiation of the first laser L1 are resumed, and laser processing of the inner periphery 100Y is resumed (step S34). Then, the modified region 4 is formed along line M11 over the entire area of ​​the imaginary surface M1, and the processing is completed (step S35). On the other hand, if step S33 is false, it is determined that an error has occurred in the processing state, and the error is reported via GUI 111 (step S36). For example, after step S36, the first processing condition and the second processing condition are reset through another process (for example, the process described in the fourth embodiment below).

[0287] In summary, the laser processing apparatus and laser processing method of this embodiment can achieve the same effects as those of the first embodiment described above. Furthermore, it has been found that if a crack extends along the imaginary surface M1 and reaches the interior of the beveled surface BB, warping will occur in the beveled surface BB. Based on this, the laser processing apparatus 101 and laser processing method of this embodiment can monitor (visually monitor) the warping of the beveled surface BB to determine when a crack reaches the beveled surface BB.

[0288] Furthermore, if the warping of the beveled surface BB becomes significant, it may cause the laser processing apparatus 1 to come into contact with the beveled surface BB. Therefore, in this embodiment, when step S33 is true, the size of the warping of the beveled surface BB is calculated based on the detection result of the ranging sensor 36. If the size of the warping of the beveled surface BB is greater than or equal to a predetermined value, the process proceeds to step S36, which involves reporting an error.

[0289] However, if laser processing is performed on the portion of object 100 located at a certain distance (e.g., 35 mm) or more from the periphery to the inner side, in order to achieve a fully cut state as described in the first cut, there is a tendency for the beveled surface BB to warp. If, after this laser processing, further laser processing is performed using a second direction E2 from the inner periphery of object 100 towards the periphery as the reference direction, there is a concern that the object 100 may crack due to the stress caused by this warping. Therefore, in this situation, by monitoring to ensure that no warping occurs before laser processing is performed using the second direction E2 as the reference direction, cracking of object 100 can be prevented in advance.

[0290] In this embodiment, although a range sensor 36 is used as the peripheral monitoring unit for monitoring the warping of the beveled surface BB, it is not limited to this. Various devices can be used as the peripheral monitoring unit, such as observation cameras or non-contact sensors, as long as the appearance of the beveled surface BB can be monitored. When using a non-contact sensor to monitor the warping of the beveled surface BB, the presence and amount of warping can be monitored in real time without stopping the laser processing. In this embodiment, although the warping of the beveled surface BB is determined by the control unit 9, the user can also determine the warping of the beveled surface BB based on the detection results of the range sensor 36. This embodiment is applicable not only to the first embodiment but also to the second embodiment.

[0291] [Fourth Implementation]

[0292] The fourth embodiment will now be described. The description of the fourth embodiment will focus on the differences from the first embodiment, while details repeated in the first embodiment will be omitted.

[0293] In this embodiment, the processing conditions for making the internal processing state of the object 100 a half-cut state, i.e., the half-cut processing conditions, are determined (recognized) in advance before the actual laser processing of the object 100 is performed.

[0294] That is, the control unit 9 performs one-line processing (second pre-processing), which involves irradiating the object 100 with the first laser L1 along a processing line under half-cut processing conditions, thereby forming a modified region 4 on the object 100. The imaging unit IR acquires a one-line image (second image), which shows the processing state in which the modified region 4 is formed along a processing line through one-line processing. The control unit 9 determines the processing state presented in the one-line image and changes the half-cut processing conditions according to the determination result. Specifically, the control unit 9 determines whether the processing state presented in the one-line image is a half-cut state, and changes the half-cut processing conditions if it is not a half-cut state. The half-cut processing conditions are prerequisites for the aforementioned first and second processing conditions. The control unit 9 sets the half-cut processing conditions (processing conditions of the second pre-processing) according to the input of the GUI 111.

[0295] Figure 33 This is a flowchart illustrating a process example for determining the conditions for partial cutting. In determining the conditions for partial cutting, the control unit 9 controls each part of the laser processing apparatus 101 to perform the process. Figure 33 The following are examples of the processes.

[0296] First, along a processing line, the first laser L1 is irradiated onto the object 100 under the set semi-cut processing conditions, thereby forming a modified region 4 on the object 100 (step S41, one-line processing). A one-line image of the processing state, showing the modified region 4 formed in step S41, is acquired using an imaging unit IR (step S42). Based on the one-line image, it is determined whether the processing state is a semi-cut state (step S43).

[0297] If step S43 is yes, the currently set half-cut processing conditions are determined to be the final processing conditions (step S44). If step S43 is no, the half-cut processing conditions are adjusted (step S45). In step S45, for example, the pulse energy of the first laser L1 is optimized (see...). Figure 28 And / or narrow the branch pitch BPy, BPx or pulse pitch. After step S45 above, return to step S41 above. In addition, the initial value of the semi-cut-off processing conditions in step S41 above can be set by the user via GUI111.

[0298] Furthermore, in this embodiment, the processing conditions for making the internal processing state of the object 100 reach the first completely cut state, i.e., the first processing conditions, are determined (recognized) in advance before actually performing laser processing on the object 100.

[0299] That is, the control unit 9 performs multi-line processing (first preprocessing), which involves irradiating the object 100 with a first laser L1 along a processing line having multiple lines arranged side by side (parallel lines) under first processing conditions, thereby forming a modified region 4 on the object 100. The imaging unit IR acquires a multi-line image (first image), which shows the processing state in which the modified region 4 is formed through multi-line processing. The control unit 9 determines the processing state presented in the multi-line image and changes the first processing conditions according to the determination result. The control unit 9 sets the first processing conditions based on the input from the GUI 111.

[0300] The imaging unit IR acquires a first multi-line image, which presents the processing state after a first predetermined amount of laser processing, as a multi-line image. The control unit 9 determines, based on the first multi-line image, whether the processing state after the first predetermined amount of laser processing is a completely cut-off state (i.e., whether it is a first completely cut-off state). If the processing state is not a first completely cut-off state, the control unit 9 changes the first processing conditions.

[0301] Figure 34 This is a flowchart illustrating a process example where the first processing condition is determined. In determining the first processing condition, the control unit 9 controls each part of the laser processing apparatus 101 to perform the process. Figure 34The following are examples of the processes.

[0302] First, along multiple parallel lines arranged side by side, the first laser L1 is irradiated onto the object 100 under the set first processing conditions, thereby forming a modified region 4 on the object 100 (step S51, multi-line processing). A first multi-line image is acquired by the imaging unit IR, showing the processing state after the modified region 4 is formed in step S51, i.e., the processing state after a first predetermined amount of laser processing (step S52). Based on the first multi-line image, it is determined whether the processing state after the first predetermined amount of laser processing is a completely cut state (first completely cut state) (step S53).

[0303] If step S53 is yes, the currently set first processing condition is determined to be the final processing condition (step S54). If step S52 is no, the first processing condition is adjusted (step S55). In step S55, for example, the pulse energy of the first laser L1 is optimized (see...). Figure 28 And / or narrow the branch pitch BPy, BPx or pulse pitch. After step S55 above, return to step S51 above. In addition, the initial value of the first processing condition in step S51 above can be set by the user via GUI111.

[0304] Furthermore, in this embodiment, the processing conditions for making the internal processing state of the object 100 reach the second completely cut state, i.e., the second processing conditions, are determined (recognized) in advance before actually performing laser processing on the object 100.

[0305] That is, the control unit 9 performs multi-line processing (first preprocessing), which involves irradiating the object 100 with the first laser L1 along a processing line having multiple lines arranged side by side (parallel lines) under second processing conditions, thereby forming a modified region 4 on the object 100. The imaging unit IR acquires a multi-line image (first image), which shows the processing state in which the modified region 4 is formed through multi-line processing. The control unit 9 determines the processing state presented in the multi-line image and changes the second processing conditions according to the determination result. The control unit 9 sets the second processing conditions based on the input from the GUI 111.

[0306] The imaging unit IR acquires a second multi-line image as a multi-line image of the processing state after laser processing with a second predetermined amount of stress applied. Stress is applied, for example, in accordance with step S16 described above (refer to...). Figure 30The stress is applied in the same way. The control unit 9 determines, based on the second multi-line image, whether the processing state after the second predetermined amount of laser processing is a completely cut-off state (i.e., whether it is a second completely cut-off state). If the processing state is not a second completely cut-off state, the control unit 9 changes the second processing conditions.

[0307] Alternatively, the imaging unit IR acquires a first multi-line image, presenting the processing state after laser processing with a first predetermined amount, as a multi-line image. The control unit 9 determines, based on the first multi-line image, whether the processing state is a first completely cut-off state. If the processing state is a first completely cut-off state, the control unit 9 changes the second processing condition. If the processing state is not a first completely cut-off state, the imaging unit IR acquires a second multi-line image, presenting the processing state after laser processing with a second predetermined amount, as a multi-line image. The control unit 9 determines, based on the second multi-line image, whether the processing state is a second completely cut-off state. If the processing state is not a second completely cut-off state, the control unit 9 changes the second processing condition.

[0308] Figure 35 This is a flowchart illustrating a process example for determining the second processing condition. In determining the second processing condition, the control unit 9 controls each part of the laser processing apparatus 101 to perform the process. Figure 35 The following are examples of the processes.

[0309] First, the first laser L1 is irradiated onto the object 100 along multiple parallel lines arranged side by side under the set second processing conditions, thereby forming a modified region 4 on the object 100 (step S61, multi-line processing). A first multi-line image showing the processing state after a first predetermined amount of laser processing is acquired by the imaging unit IR (step S62). Based on the first multi-line image, it is determined whether the processing state after the first predetermined amount of laser processing is a completely cut state (first completely cut state) (step S63).

[0310] If step S63 is not successful, i.e., the processing state is a partially cut or partially cut state, multi-line processing continues (step S64). A second multi-line image showing the processing state after laser processing of the second predetermined amount is acquired by the imaging unit IR (step S65). Based on the second multi-line image, it is determined whether the processing state after laser processing of the second predetermined amount is a fully cut state (second fully cut state) (step S66).

[0311] If step S66 is true, the currently set second processing condition is determined to be the final processing condition (step S67). If step S63 is true, the second processing condition is adjusted (step S68). In step S68, for example, the branch pitch BPy, BPx, or pulse pitch is increased.

[0312] If step S66 is not successful, adjust the second processing conditions (step S69). In step S69, for example, optimize the pulse energy of the first laser L1 (refer to...). Figure 28 And / or narrow the branch pitch BPy, BPx or pulse pitch. After step S68 or step S69 above, return to step S61 above. In addition, the initial value of the second processing condition in step S61 above can be set by the user via GUI111.

[0313] As described above, the laser processing apparatus 101 and laser processing method of this embodiment can achieve the same effects as those of the first embodiment. Furthermore, it has been found that there is a correlation between the peeling off of the object 100 and the processing state in which the modified region 4 is formed along a processing line having multiple parallel lines. Therefore, the laser processing apparatus 101 and laser processing method of this embodiment obtain a multi-line image showing the processing state in which the modified region 4 is formed along a processing line having multiple parallel lines. Based on this multi-line image, the processing conditions can be determined in a manner that allows the object 100 to be peeled off. Therefore, the object 100 can be reliably peeled off.

[0314] It was discovered that there is a correlation between the peeling of the object 100 and the processing state in which the modified region 4 is formed along a processing line. Therefore, the laser processing apparatus 101 and laser processing method of this embodiment obtain a one-line image showing the processing state in which the modified region 4 is formed along a processing line. Based on this one-line image, the processing conditions can be determined in a way that allows the object 100 to be peeled off. Therefore, the object 100 can be reliably peeled off.

[0315] The laser processing apparatus 101 and laser processing method of this embodiment determine the processing state presented in the one-line image. The partial cut-off processing conditions are then changed according to this determination result. In this case, the partial cut-off processing conditions can be automatically changed according to the one-line image.

[0316] It was discovered that if the processing state when forming the modified region 4 along a processing line is not a half-cut state, peeling off the object 100 becomes difficult. Therefore, in this embodiment, the laser processing apparatus 101 and laser processing method change the half-cut processing conditions when the processing state presented in the 1-line image is not a half-cut state. In this way, the half-cut processing conditions can be determined in a way that allows the object 100 to be peeled off.

[0317] The laser processing apparatus 101 and laser processing method of this embodiment determine the processing state presented in a multi-line image. Based on the determination result, the first and second processing conditions are changed. In this case, the first and second processing conditions can be automatically changed according to the first image.

[0318] It was discovered that when forming the modified region 4 along a processing line having multiple parallel lines, if laser processing is performed in a manner that ensures the processed state after the first predetermined amount of laser processing is a completely cut state, the object 100 can be reliably peeled off. Therefore, in the laser processing apparatus and laser processing method of this embodiment, it is determined whether the processed state after the first predetermined amount of laser processing is a completely cut state based on the first multi-line image. If it is not a completely cut state, the first processing conditions are changed. In this way, the first processing conditions that can reliably peel off the object 100 can be determined.

[0319] It was discovered that when forming the modified region 4 along a processing line having multiple parallel lines, if the processing state after the second predetermined amount of laser processing is performed in a manner that ensures a complete cut, the increase in production time can be suppressed, and the object 100 can be peeled off. Therefore, in the laser processing apparatus 101 and laser processing method of this embodiment, it is determined whether the processing state after the second predetermined amount of laser processing is a complete cut based on the second multi-line image. If it is not a complete cut, the second processing condition is changed. In this way, a second processing condition that suppresses the increase in production time and peels off the object 100 can be determined.

[0320] In this embodiment, although the partial cutting processing condition, the first processing condition, and the second processing condition are determined, it is sufficient to determine at least one of them. For example, if the partial cutting state cannot be confirmed using the camera unit IR, it is sufficient to determine at least one of the first processing condition and the second processing condition. In this embodiment, although the processing state is automatically determined by the control unit 9, the user can also determine the processing state based on the imaging results of the camera unit IR. Steps S51 and S61 constitute the first pre-process, and steps S52 and S62 constitute the first imaging process. This embodiment is not only applicable to the first embodiment but also to the second or third embodiment.

[0321] Examples of objects 100 used to determine processing conditions in this embodiment include: wafers used for operation (practice) that are not ultimately made into semiconductor devices (products) through peeling processes (wafers for determining conditions), and wafers used for production (wafers for semiconductor devices) that are ultimately made into semiconductor devices through peeling processes (wafers for semiconductor devices). In the former case, processing lines can be set at any point in the entire area of ​​the wafer to determine the processing conditions. In the latter case, processing lines can be set in the outer edge area of ​​the wafer where they have less impact on peeling quality to determine the processing conditions, and peeling processes can be continuously performed under the determined processing conditions. For example, the latter method can be used when processing conditions must be adjusted for each wafer due to unevenness of the back film.

[0322] [Variation Example]

[0323] The above is one embodiment of the present invention and is not limited to the above-described embodiments.

[0324] In the above embodiment, a finishing process to form the modified region 43 is performed before the object 100 is peeled off by the peeling process, but as... Figure 36 (a) and Figure 36 As shown in (b), after the object 100 is peeled off by the peeling process, the removed area E can also be removed by the trimming process. In this case, the removed portion that was removed from the object 100 by the peeling process can also be reused.

[0325] In addition, such as Figure 37 (a) and Figure 37 As shown in (b), after forming the modified region 4 along the imaginary surface M1 within the effective region R of the object 100 through peeling processing, the removal region E can also be removed through trimming processing. Furthermore, as... Figure 38 (a) and Figure 38 As shown in (b), after removing the removal area E through trimming, the object 100 can also be peeled off through peeling.

[0326] In the above embodiment, the machining line is not limited to the spiral-shaped line M11; machining lines of various shapes can be set on the object 100. For example, Figure 39 As shown, multiple straight lines (parallel lines) M12 can be set on the object 100 in a manner arranged along a predetermined direction. These multiple lines M12 are included in the line (processing line) M20. The line M12, although imaginary, can also be an actual drawn line. The coordinates of the line M12 can also be specified. The multiple lines M12 arranged side by side can be partially or completely connected, or they can be unconnected.

[0327] The above-described embodiment can include multiple laser processing heads serving as irradiation units. When multiple laser processing heads serve as irradiation units, laser processing can be performed using multiple laser processing heads in each of the first processing step (first processing step), second processing step (second processing step), first preprocessing step (first preprocessing step), and second preprocessing step (second preprocessing step).

[0328] In the above embodiment, although a reflective spatial light modulator 34 is used, the spatial light modulator is not limited to a reflective type; a transmissive spatial light modulator may also be used. In the above embodiment, there are no particular limitations on the type of object 100, the shape of object 100, the size of object 100, the number and direction of crystal orientations of object 100, or the orientation of the main surface of object 100.

[0329] In the above embodiment, although the back surface 100b of the object 100 is set as the laser incident surface, the surface 100a of the object 100 can also be set as the laser incident surface. In the above embodiment, the modified region can be, for example, a crystalline region, a recrystallization region, or a gettingting region formed inside the object 100. The crystalline region is the region that maintains the structure of the object 100 before processing. The recrystallization region is the region that, after being evaporated, plasma-ionized, or melted, solidifies into a single crystal or polycrystalline form during re-solidification. The gettingting region is the region that gathers and captures impurities such as heavy metals to exert a gettingting effect; it can be formed continuously or intermittently. The above embodiment is also applicable to processes such as ablation.

[0330] In the laser processing described above, during the second processing step, if the device reaches its limit (the rotational speed of the stage 107 is at its maximum rotational speed), the pitch of the modified points SA contained in the modified region 4 may narrow. In this case, other processing conditions can be changed in a way that makes the pitch a certain interval.

[0331] For other variations, please refer to the following explanation.

[0332] like Figure 40As shown, the main difference between the laser processing apparatus 1A and the laser processing apparatus 1 described above is that the latter includes an alignment camera AC and an image unit IR, and a laser processing head (first irradiation unit) 10B is mounted on the mounting unit 66 via a rotary mechanism 67. In this embodiment, the laser processing apparatus 1A performs trimming and peeling processes on an object 100 having a surface 100a (hereinafter also referred to as "first main surface 100a") and a surface 100b (hereinafter also referred to as "second main surface 100b") to obtain (manufacture) a semiconductor device. Trimming is a process for removing unwanted portions of the object 100. Peeling is a process for peeling off a portion of the object 100. First, the structure of the laser processing apparatus 1A will be explained focusing on the differences from the laser processing apparatus 1 described above. In addition, Figure 40 The icons for the device frame 1a, light source unit 8, etc., are omitted in the middle.

[0333] like Figure 40 As shown, the alignment camera AC and the imaging unit IR are mounted on the mounting section 65 together with the laser processing head (second irradiation section) 10A. The alignment camera AC, for example, uses light that penetrates the object 100 to capture a pattern. Based on the image obtained by the alignment camera AC, the irradiation position of the laser L1 on the object 100 is aligned. The imaging unit IR captures an image of the object 100 using light that penetrates it. For example, when the object 100 is a silicon-containing wafer, near-infrared light is used in the imaging unit IR. Based on the image obtained by the imaging unit IR, the condition of the modified regions formed inside the object 100 and the cracks extending from these modified regions is confirmed.

[0334] The laser processing head 10B is mounted on the mounting section 66 via a rotary mechanism 67. The rotary mechanism 67 is mounted on the mounting section 66 in a manner that allows rotation around an axis parallel to the X-direction. Thus, the moving mechanism 6 can change the orientation of the laser processing head 10B, causing the optical axis of the focusing section (first focusing section) 14 of the laser processing head 10B to be in a state parallel to the Y-direction (a first direction intersecting the direction perpendicular to the surface of the object) parallel to the second main surface 100b of the object 100, or to be in a state perpendicular to the Z-direction (a second direction) perpendicular to the second main surface 100b. Furthermore, in the laser processing apparatus 1A, the state where the optical axis of the focusing section 14 is along the first direction refers to a state where the optical axis forms an angle of 10° or less relative to the first direction; the state where the optical axis of the focusing section 14 is along the second direction refers to a state where the optical axis forms an angle of 10° or less relative to the second direction.

[0335] Next, the object 100 to be processed by the laser processing apparatus 1A will be described. The object 100 includes, for example, a semiconductor wafer formed in a circular plate shape. The object 100 can be formed of various materials and can have various shapes. Functional elements (not shown) are formed on the first main surface 100a of the object 100. These functional elements include, for example, light-receiving elements such as photodiodes, light-emitting elements such as laser diodes, and circuit elements such as memory.

[0336] like Figure 41 As shown in (a) and (b), an effective portion RR and a peripheral portion EE are provided in the object 100. The effective portion RR is the portion corresponding to the semiconductor device to be obtained. The effective portion RR, for example, is a circular plate-shaped portion including the central portion when the object 100 is viewed from the thickness direction. The peripheral portion EE is the region in the object 100 that is further outward than the effective portion RR. The peripheral portion EE is the outer edge portion of the object 100 other than the effective portion RR. The peripheral portion EE, for example, is an annular beveled portion (beveled surface) surrounding the effective portion RR.

[0337] On the object 100, an imaginary surface M1 is set as the predetermined peeling surface. The imaginary surface M1 is the surface intended to form a modified region. The imaginary surface M1 is the surface facing the laser incident surface of the object 100, i.e., the second main surface 100b (i.e., the surface opposite to the second main surface 100b). The imaginary surface M1 includes a first region M1a and a second region M1b. The first region M1a is the region within the imaginary surface M1 located in the effective portion RR. The second region M1b is the region within the imaginary surface M1 located in the peripheral portion EE. The imaginary surface M1 is a surface parallel to the second main surface 100b, and is, for example, circular. The imaginary surface M1 is an imaginary region and is not limited to a plane; it can be a curved surface or a three-dimensional surface. The setting of the effective portion RR, the peripheral portion EE, and the imaginary surface M1 can be performed in the control unit 9. The effective portion RR, the peripheral portion EE, and the imaginary surface M1 can also be specified with coordinates.

[0338] A line M3 is set on the object 100 as a predetermined trimming line. Line M3 is a line that is intended to form a modified region. Line M3 extends in a loop on the inner side of the outer edge of the object 100. Line M3 may extend in a circular loop, for example. Line M3 is set on the boundary between the effective portion RR and the peripheral portion EE in the portion inside the object 100 that is closer to the laser incident surface than the imaginary surface M1. The setting of line M3 can be performed in the control unit 9. The coordinates of line M3 can also be specified.

[0339] The following describes an example of a method for manufacturing (obtaining) a semiconductor device by performing trimming and stripping processes on an object 100 using a laser processing apparatus 1A. The manufacturing method described below allows for the reuse of the removed portions (parts of the object 100 that are not used as semiconductor devices) that are removed from the object 100 through trimming and stripping processes.

[0340] First, such as Figure 40 As shown, with the second main surface 100b as the laser incident surface side, the object 100 is supported by the support portion 7. On the first main surface 100a side of the object 100 where functional elements are formed, a substrate such as a support substrate is joined, or adhesive tape is applied.

[0341] Next, as Figure 42 and Figure 43 As shown in (a), the object 100 is trimmed. Specifically, the laser processing head 10A is positioned such that the focusing part (second focusing part) 14 is above line M3 and the first focusing point P1 of laser L1 (hereinafter also referred to as "focusing point P1") is on line M3. The support part 7 is moved by the moving mechanism 5 and the laser processing head 10A is moved by the moving mechanism 6. Moreover, while the moving mechanism 5 rotates the support part 7 at a certain rotational speed about the rotation axis C (hereinafter also referred to as "axis C"), laser L1 is emitted from the laser processing head 10A with the focusing point P1 on line M3. The laser L1 is repeatedly irradiated by changing the position of the focusing point P1 in the Z direction. Thus, as Figure 43 As shown in (b), prior to the stripping process, the imaginary surface M1 (refer to) inside the object 100 is compared to the surface before the stripping process. Figure 41 The portion further away from the laser incident surface, along line M3 (refer to...) Figure 41 A modified region 43 is formed. In addition, during the finishing process of the object 100, the optical axis of the focusing part 14 of the laser processing head 10A is along the Z direction, and the second main surface 100b of the object 100 is the laser L1 incident surface.

[0342] Next, as Figure 42 and Figure 44 As shown in (a), a peeling process is performed on the effective portion RR of the object 100. Specifically, while the support 7 is rotated at a certain rotational speed by the moving mechanism 5 with the axis C as the center line, and the laser L1 is emitted from the laser processing head 10A, a peeling process is performed on the first region M1a of the imaginary surface M1 (refer to...). Figure 41 The laser processing head 10A is moved by the moving mechanism 6 in a manner that moves the focusing point P1 from the outside to the inside along the Y direction. Thus, as... Figure 44As shown in (b) and (c), inside the object 100, along the first region M1a (refer to...) Figure 41 A modified region 4 extending in a spiral (involute) shape is formed. During the peeling process of the effective portion RR of the object 100, the optical axis of the focusing portion 14 of the laser processing head 10A is along the Z direction, and the second main surface 100b of the object 100 is the incident surface of the laser L1. Thus, during the peeling process of the effective portion RR of the object 100, with the optical axis of the focusing portion 14 of the laser processing head 10A along the Z direction, the modified region 4 is formed along the first region M1a inside the effective portion RR. The support portion 7, the laser processing head 10A, and the multiple moving mechanisms 5,6 are controlled by the control unit 9.

[0343] Next, as Figure 45 and Figure 46 As shown, a peeling process is performed on the peripheral portion EE of the object 100. Specifically, the direction in which the laser processing head 10B faces is changed by the moving mechanism 6 so that the optical axis of the focusing part 14 of the laser processing head 10B is aligned with the Y direction. Figure 41 and Figure 47 As shown, the support 7 is moved by the moving mechanism 5 and the laser processing head 10B is moved by the moving mechanism 6, so that the focusing point P2 of the laser L2 is located on the second region M1b of the imaginary surface M1. Furthermore, while the support 7 rotates at a certain speed around the axis C via the moving mechanism 5, the laser L2 is emitted from the laser processing head 10B with the focusing point P2 of the laser L2 located on the second region M1b. Thus, a modified region 4a is formed along the second region M1b inside the peripheral portion EE. From this modified region 4a, cracks 4b extend inward (i.e., along the modified region 4 side of the first region M1a) and outward (i.e., the side EE1 side of the object 100).

[0344] In the peeling process of the peripheral portion EE of the object 100, the optical axis of the focusing part 14 of the laser processing head 10B is along the Y direction, and the side EE1 of the object 100 is the incident surface of the laser L2. For example... Figure 46 and Figure 47As shown, side surface EE1 is a surface perpendicular to the first main surface 100a and the second main surface 100b (a perpendicular surface when viewed from a direction parallel to the first main surface 100a and the second main surface 100b) among the side surfaces intersecting the first main surface 100a and the second main surface 100b. Side surface EE2 is a chamfered surface formed between the first main surface 100a and side surface EE1 and between the second main surface 100b and side surface EE1 among the side surfaces intersecting the first main surface 100a and the second main surface 100b; for example, it is a rounded arc shape convex outwards. Side surfaces EE1 and EE2 are included in the peripheral portion EE. In this embodiment, side surfaces EE1 and EE2 constitute the inclined surface portion.

[0345] As described above, during the peeling process of the peripheral portion EE of the object 100, with the optical axis of the focusing section 14 of the laser processing head 10B aligned with the Y direction, a modified region 4a is formed inside the peripheral portion EE. The support section 7, the laser processing head 10B, and multiple moving mechanisms 5 and 6 are controlled by the control unit 9. Furthermore, with the optical axis of the focusing section 14 of the laser processing head 10B aligned with the Y direction, the moving mechanism 5 is controlled by the control unit 9 to rotate the support section 7 around an axis C perpendicular to the second main surface 100b of the object 100. Additionally, with the optical axis of the focusing section 14 of the laser processing head 10B aligned with the Y direction, the polarization direction of the laser L2 emitted from the focusing section 14 of the laser processing head 10B is along the direction in which the laser L2 moves relative to the object 100 from its focusing point P2.

[0346] Next, as Figure 48 As shown in (a), to cover the imaginary surface M1 (refer to) Figure 41 A portion of the object 100 is peeled off, with the modified region and the cracks extending from the modified region as boundaries. Simultaneously, along line M3 (refer to...) Figure 41 The modified region and the cracks extending from the modified region are used as boundaries to remove the peripheral portion EE. Alternatively, the peeling of a portion of the object 100 and the removal of the peripheral portion EE can be performed, for example, using an adsorption device. The peeling of a portion of the object 100 can be performed on the support 7 or by moving it to a dedicated peeling area. The peeling of a portion of the object 100 can be performed using air blowing or adhesive tape. When external stress alone is insufficient to peel the object 100, an etching solution (KOH or TMAH, etc.) that reacts with the object 100 can be used to selectively etch the modified regions 4 and 43. In this way, the object 100 can be easily peeled off. Although the support 7 is rotated at a certain speed, this rotation speed can be changed. For example, the rotation speed of the support 7 can be changed in such a way that the pitch of the modified points contained in the modified region 4 becomes a certain interval.

[0347] Next, as Figure 48 As shown in (b), the peeled surface 100h of the object 100 is subjected to fine grinding or polishing using an abrasive such as a grinding stone. This polishing process can be simplified when the object 100 is peeled off by etching. The above results in the acquisition of the semiconductor device 100k.

[0348] Furthermore, in typical peeling processes, the pitch of the multiple modified points SA contained in the modified region 4 to be formed narrows, and the modified points SA are arranged to fill the imaginary surface M1, which serves as the predetermined peeling surface, before the object 100 is peeled off. In this case, the processing conditions are selected to minimize the propagation of cracks from the modified points SA (for example, the laser wavelength is a short wavelength (1028 nm), the pulse width is 50 nm, and the pulse pitch is 1 to 10 μm (especially 1.5 to 3.5 μm)). In contrast, in this embodiment, the processing conditions are selected to allow the cracks to propagate along the imaginary surface M1. For example, the processing conditions for the first laser L1 used to form the modified region 4 along the first region M1a of the imaginary surface M1 are: the wavelength of the first laser L1 is a long wavelength (for example, 1099 nm), and the pulse width is 700 nm.

[0349] [Functions and Effects]

[0350] In the laser processing apparatus 1A, with the optical axis of the focusing section 14 of the laser processing head 10B aligned with the Y direction, which intersects the direction perpendicular to the second main surface 100b of the object 100, laser L2 is focused and emitted from the focusing section 14 of the laser processing head 10B, thereby forming a modified region 4a inside the peripheral portion EE of the object 100. Thus, even if, for example, the sides EE1, EE2 of the object 100 include chamfered surfaces to improve intensity, laser L2 can still be appropriately focused inside the peripheral portion EE of the object 100, including those sides EE1, EE2. Therefore, according to the laser processing apparatus 1A, the modified region 4a can be formed with good precision inside the peripheral portion EE of the object 100.

[0351] Figure 49 (a) is a cross-sectional photograph showing the periphery of the object. Figure 49 (b) To display Figure 49 (a) is a magnified cross-sectional photograph of a portion of the image. Figure 49 In the examples shown in (a) and (b), the object is a silicon wafer with a beveled perimeter. The horizontal width of this beveled portion (parallel to the main surface of the silicon wafer) is approximately 200–300 μm, and the vertical width (perpendicular to the main surface of the silicon wafer) of the side surface constituting this beveled portion is approximately 100 μm. Figure 49 In the examples shown in (a) and (b), the surface perpendicular to the main surface of the silicon wafer among the side surfaces constituting the inclined portion is designated as the laser incident surface, and the laser is focused horizontally from the outside of the inclined portion toward the inside. As a result, a modified region is formed inside the peripheral portion, and cracks extend horizontally from this modified region inward and outward. The extension of the cracks is approximately 120 μm.

[0352] Furthermore, in the laser processing apparatus 1A, with the optical axis of the focusing section 14 of the laser processing head 10A aligned along the Z direction perpendicular to the second main surface 100b of the object 100, laser L1 is focused and emitted from the focusing section 14 of the laser processing head 10A, thereby forming a modified region 4 along the imaginary surface M1 inside the effective portion RR of the object 100. Thus, the modified region 4 can be formed with good precision along the imaginary surface M1 inside the effective portion RR of the object 100.

[0353] Furthermore, in the laser processing apparatus 1A, with the optical axis of the focusing portion 14 of the laser processing head 10B aligned with the Y direction, the support portion 7 is rotated around the axis C perpendicular to the second main surface 100b as the center line, thereby forming a modified region 4a inside the peripheral portion EE of the object 100. Thus, the modified region 4a can be efficiently and effectively formed inside the peripheral portion EE of the object 100.

[0354] Furthermore, in the laser processing apparatus 1A, with the optical axis of the focusing section 14 of the laser processing head 10B aligned with the Y direction, the polarization direction of the laser L2 emitted from the focusing section 14 of the laser processing head 10B is along the direction in which the laser L2 moves relative to the object 100 from its focusing point P2. Thus, the extension of the crack 4b extending from the modified region 4a towards the second main surface 100b of the object 100 within the peripheral portion EE of the object 100 can be increased.

[0355] Furthermore, in the variations described above, for example, the moving mechanisms 5 and 6 only need to be configured to move at least one of the support portion 7 and the laser processing head 10A. Similarly, the moving mechanisms 5 and 6 only need to be configured to move at least one of the support portion 7 and the laser processing head 10B.

[0356] Furthermore, with the optical axis of the focusing section 14 of the laser processing head 10B aligned with the Z-direction, the modified region 4 can be formed along the imaginary surface M1 within the effective portion RR of the object 100, and the support section 7, the laser processing head 10B, and the moving mechanisms 5 and 6 can be controlled by the control section 9. In this way, the modified region 4 can be formed with good precision along the imaginary surface M1 within the effective portion RR of the object 100, either together with or replacing the laser processing head 10A.

[0357] Furthermore, when the laser processing head 10B is in a state where the optical axis of its focusing part 14 is along the Z direction and the optical axis of its focusing part 14 is along the Y direction, and the modified region 4 is formed on the object 100, the laser processing apparatus 1A may not have a laser processing head 10A.

[0358] Furthermore, the laser processing head 10B can also be specifically used to form a modified region 4a on the peripheral portion EE of the object 100 when the optical axis of its focusing section 14 is along the Y direction. In this case, when the laser processing apparatus 1A is specifically used to form the modified region 4a on the peripheral portion EE of the object 100, the laser processing apparatus 1A may not need to have a laser processing head 10A.

[0359] Furthermore, in laser processing device 1A, such as Figure 50 As shown, the laser L2 can be focused and emitted from the focusing section 14 of the laser processing head 10B while the optical axis of the focusing section 14 is positioned in a direction other than the Y direction, which intersects the direction perpendicular to the second main surface 100b of the object 100 (i.e., the Z direction). This is done in a manner that forms a modified region 4a inside the peripheral portion EE of the object 100. In this way, the optical axis angle of the focusing section 14 of the laser processing head 10B can be adjusted according to the shape of the side surfaces EE1, EE2 constituting the peripheral portion EE, so that the laser L2 is appropriately focused inside the peripheral portion EE. Furthermore, the direction in which the optical axis of the focusing section 14 of the laser processing head 10B intersects the direction perpendicular to the second main surface 100b of the object 100 (the first direction intersecting the direction perpendicular to the surface of the object) is, for example, a direction forming an angle of 10 to 90° relative to the direction perpendicular to the second main surface 100b of the object 100, or a direction forming an angle of 30 to 90° relative to the direction perpendicular to the second main surface 100b of the object 100.

[0360] Furthermore, in the above embodiment, although the peeling process is performed on the effective portion RR of the object 100 before the peeling process is performed on the peripheral portion EE of the object 100, it is also possible to perform the peeling process on the peripheral portion EE of the object 100 before the peeling process is performed on the effective portion RR of the object 100. Furthermore, in the above embodiment, although the second main surface 100b of the object 100 is designated as the laser incident surface, it is also possible to designate the first main surface 100a of the object 100 as the laser incident surface. Moreover, the laser processing apparatus 1A can also be applied to processes such as ablation.

[0361] Furthermore, there are no particular limitations on the type, shape, size, number and orientation of crystallization sites of the object 100, or the orientation of its main surface. Additionally, the modification region may be a crystalline region, a recrystallization region, or an adsorption region formed within the object 100. A crystalline region is a region that maintains the original structure of the object 100 before processing. A recrystallization region is a region that, after evaporation, plasma treatment, or melting, solidifies into a single crystal or polycrystalline form. An adsorption region is a region that aggregates and captures impurities such as heavy metals to achieve an adsorption effect.

[0362] The components in the above embodiments and modifications are not limited to the materials and shapes described above, and various materials and shapes can be used. Furthermore, the components in the above embodiments or modifications can be arbitrarily applied to the components in other embodiments or modifications.

[0363] [Symbol Explanation]

[0364] 1,101: Laser processing equipment

[0365] 4,43: Modified Zone

[0366] 6,300: Mobile mechanism

[0367] 9: Control Department

[0368] 10A, 10B: Laser processing head (irradiation section)

[0369] 36: Ranging sensor (perimeter monitoring unit)

[0370] 100: Object

[0371] 100a: Surface

[0372] 100b: Back side (laser incident surface)

[0373] 100X: Peripheral area of ​​the slope (Part 1)

[0374] 100Y: Inner Peripheral Section (Part 2)

[0375] 107: Platform (Support Section)

[0376] 111: GUI (Input Section)

[0377] BB: Peripheral area (slanted face)

[0378] E1: First Direction

[0379] E2: Second Direction

[0380] IR: Camera Unit (Camera Section, Processing Status Monitoring Section)

[0381] L1: First laser (laser)

[0382] L2: Second laser (laser)

[0383] M1: Imaginary Face

[0384] M11: Wire (for machining)

[0385] M11a: Parallel Line

[0386] M12: Line (parallel line, machining line)

[0387] M20: Wire (for processing)

[0388] P1: First focusing point (focusing point)

[0389] SA: Modified particle size.

Claims

1. A laser processing apparatus, wherein, This is a laser processing apparatus that forms a modified region along an imaginary surface inside an object by irradiating it with a laser. The object includes a peripheral portion having sides that intersect with the laser incident surface. The laser processing apparatus includes: A support portion that supports the object; An irradiation unit that irradiates the object supported by the support portion with the laser; A moving mechanism that moves at least one of the support and the irradiation part in such a way as to move the position of the laser focusing point along the imaginary surface; as well as A control unit that controls the support, the irradiation unit, and the moving mechanism. The control unit, A laser is applied along a processing line extending in a spiral shape from the peripheral portion of the object, under conditions where the processing state is a complete cutting state, thereby forming a modified region extending in a spiral shape from the peripheral portion of the object towards the inside. The complete severance of the cut refers to a state in which the cracks extending from the multiple modified points contained in the modified region extend and connect along the direction of the processing line and in the direction intersecting the processing line. The modified region migrates in a direction from the periphery of the object toward the inward side.

2. The laser processing apparatus as described in claim 1, wherein, The control unit implements... The first processing step involves irradiating the first portion, which includes the peripheral portion, with the laser under the first processing conditions; The second processing step involves irradiating the second portion of the object, which is more inner than the first portion, with the laser under second processing conditions after the first processing step. The first processing condition is that the processing state after the first specified amount of laser processing becomes the condition for the complete cutting state. The second processing condition is that the processing state after laser processing, which is more than the first specified amount, becomes the condition for the complete cutting state.

3. A laser processing method, wherein, This is a laser processing method that forms a modified region along an imaginary surface inside an object by irradiating it with a laser. The object includes a peripheral portion having sides that intersect with the laser incident surface. The laser processing method comprises: The process involves irradiating the object with a laser along a processing line extending in a spiral shape from the peripheral portion toward the inward side, under conditions where the processing state is a complete cutting state, to form a modified region extending in a spiral shape from the peripheral portion of the object toward the inward side. The complete severance of the cut refers to a state in which the cracks extending from the multiple modified points contained in the modified region extend and connect along the direction of the processing line and in the direction intersecting the processing line. The modified region migrates in a direction from the periphery of the object toward the inward side.

4. The laser processing method as described in claim 3, wherein, The process of forming the modified region extending in a vortex shape includes: In the first processing step, the laser is irradiated onto the first portion including the peripheral portion under the first processing conditions; In the second processing step, after the first processing step, the second portion of the object that is more inner than the first portion is irradiated with the laser under the second processing conditions. The first processing condition is that the processing state after the first specified amount of laser processing becomes the condition for the complete cutting state. The second processing condition is that the processing state after laser processing, which is more than the first specified amount, becomes the condition for the complete cutting state.

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