Object processing method

Abstract

A method of processing an object, the method including: a laser processing step of forming a modified region along an imaginary surface inside the object by irradiating laser light to the object. The object has a surface, a part of the surface side is set as a removal region, and the imaginary surface includes: a first surface extending in a direction intersecting the surface; and a second surface connected to the opposite side of the first surface from the surface side via a connection portion and extending in a direction intersecting the first surface. In a cross-sectional view intersecting the surface, a first angle formed by the first surface and the second surface and a second angle formed by the surface and the second surface are obtuse angles, the first angle is smaller than the second angle, and the connection portion is disposed in the removal region in the object.

Description

Technical Field

[0001] This disclosure relates to a method for processing objects. Background Technology

[0002] As a method for processing objects, there is a known method that includes a laser processing step that forms a modified region along an imaginary surface inside the object by irradiating the object with a laser (for example, see Patent Document 1). After the laser processing step, a portion of the object is peeled off, with the modified region covering the imaginary surface as its boundary. In such an object processing method, a portion of the surface side of the object is designated as a removal region, for example, by grinding.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-002312 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In techniques like those described above, for example, when a portion of the object is peeled off with the modified region covering the imaginary surface as the boundary, there is a possibility that a portion of the object may remain as a residue on the peeled surface (the surface corresponding to the peeled imaginary surface). As a result, this residue may adversely affect the quality of the processed object, leading to concerns about a deterioration in the quality of the processed object.

[0008] Therefore, the technical problem of this disclosure is to provide a method for processing objects that can suppress the deterioration of the quality of the processed objects.

[0009] Technical means to solve the problem

[0010] The object processing method disclosed herein is as follows: [1] "An object processing method is an object processing method for processing an object, comprising: a laser processing step, wherein a modified region is formed along an imaginary surface inside the object by irradiating the object with a laser, the object having a surface, a portion of the surface side being set as a removal region, the imaginary surface comprising: a first surface extending in a direction intersecting the surface; and a second surface connected to the opposite side of the surface side of the first surface via a connecting portion and extending in a direction intersecting the first surface, wherein in a cross-sectional view intersecting the surface, a first angle formed by the first surface and the second surface and a second angle formed by the surface and the second surface are obtuse angles, the first angle being smaller than the second angle, and the connecting portion being provided in the object in the removal region."

[0011] In the object processing method of this disclosure, by defining the first and second angles, for example, when peeling off a portion of the imaginary surface with the modified region covering the imaginary surface as the boundary, a portion of the object that was not completely peeled off, namely the residual portion (hereinafter also simply referred to as the "residual portion"), can be easily concentrated around the periphery of the portion corresponding to the connection between the first and second surfaces of the imaginary surface on the peeled surface. Then, since the connection portion is provided in the removal area, the residual portion is also removed when the removal area is removed, thus suppressing the residual portion from adversely affecting the quality of the processed object. Therefore, according to this disclosure, the quality deterioration of the processed object can be suppressed.

[0012] The object processing method disclosed herein may also be, [2] "According to the object processing method described in [1] above, it includes: a peeling step, in which, after the laser processing step, the modified region covering the imaginary surface is set as a boundary and a portion of the object is peeled off; and a removal step, in which, after the laser processing step, the removal area of ​​the object is removed." In this case, the peeling off of a portion of the object and the removal of the removal area can be performed.

[0013] The object processing method disclosed herein can also be, [3] "according to the object processing method described in [2] above, wherein the removal process is performed by grinding the removal area." In this case, the removal process can be specifically implemented.

[0014] The object processing method disclosed herein can also be, [4] "According to any one of [1] to [3] above, the object processing method comprises: a third surface connected to the opposite side of the surface side of the second surface and extending in a direction intersecting the second surface, wherein in a cross-sectional view intersecting the surface, the third angle formed by the second surface and the third surface is an obtuse angle, and the first angle is smaller than the third angle." In this case, for example, when peeling off a portion of the object with the modified area covering the imaginary surface as the boundary, it is also possible to easily concentrate the remaining portion around the periphery of the part corresponding to the connecting portion on the peeled surface. Furthermore, the position of the first surface in the object can be easily adjusted according to the user's requirements without changing the first angle.

[0015] The object processing method disclosed herein can also be, [5] "according to any of the object processing methods described in [1] to [4] above, wherein the object is configured to include: a peripheral portion located at the periphery when viewed from a direction opposite to the surface; and a main body portion located closer to the inside than the peripheral portion, wherein the first surface is formed inside the object along the boundary between the peripheral portion and the main body portion in the object." In this case, at least a portion of the peripheral portion can be peeled off.

[0016] The object processing method disclosed herein may also be, [6] "According to the object processing method described in [5] above, it includes: a peripheral processing step, wherein the modified region is formed by irradiating the laser along a radial line extending radially from the inner side to the outer side of the peripheral region." Thus, the peeling can be reliably achieved when peeling off the peripheral region.

[0017] The object processing method disclosed herein can also be, [7] "according to any one of [1] to [6] above, the object has a first substrate and a second substrate, a first device layer is formed on the main surface of the first substrate, a second device layer is formed on the main surface of the second substrate, and the first substrate and the second substrate are bonded via the first device layer and the second device layer." In such an object, for example, after peeling off a portion of the object with the modified region covering the imaginary surface as the boundary, the effect of suppressing damage to the outer periphery is achieved compared to an object having only one substrate.

[0018] The object processing method disclosed herein may also be, [8] "According to any one of [1] to [7] above, the object processing method comprises: a first laser processing step, wherein the modified region is formed by irradiating the laser along at least a first portion of the imaginary surface under a first processing condition; and a second laser processing step, wherein, after the first laser processing step, the modified region is formed by irradiating the laser along the imaginary surface under a second processing condition, wherein the first processing condition is a condition in which a plurality of cracks contained in the modified region are discontinuously connected, and the second processing condition is a condition in which the plurality of cracks contained in the modified region formed by the first and second laser processing steps are interconnected after the second laser processing step and extend throughout the entire region of the imaginary surface." In such an object processing method, firstly, a plurality of discontinuously connected cracks are formed along at least a first portion of the imaginary surface by the first laser processing step, and then, by the subsequent second laser processing step, the plurality of cracks are connected and extend throughout the entire region of the imaginary surface. In this case, by using multiple intermittently connected cracks, the propagation of cracks covering the entire area of ​​the imaginary surface can be appropriately guided. Therefore, compared to the case where multiple cracks extending across the entire area of ​​the imaginary surface are formed in one laser processing operation, the accidental formation of cracks not along the imaginary surface on the object can be prevented.

[0019] The effects of the invention

[0020] According to this disclosure, a method for processing an object can be provided, which can suppress the quality deterioration of the processed object. Attached Figure Description

[0021] Figure 1 This is a structural diagram illustrating the object processing system of the implementation method.

[0022] Figure 2 It means Figure 1 A schematic diagram of the structure of a laser processing head.

[0023] Figure 3 (a) means Figure 1 An example diagram of the input / output screen of the GUI of a laser processing device. Figure 3 (b) means Figure 1 An example diagram of the input / output screen of the GUI of a grinding device.

[0024] Figure 4 (a) means Figure 1 A top view of the object. Figure 4 (b) is along Figure 4 (a) Cross-sectional view of line AA.

[0025] Figure 5 It will be along Figure 4 The diagram is shown by enlarging a portion of the cross section of the BB line in (b).

[0026] Figure 6 (a) is a side cross-sectional view of a portion of the object for illustrating the object processing method of the embodiment. Figure 6 (b) is to Figure 6 The diagram is represented by an enlarged portion of (a). Figure 6 (c) represents Figure 6 (a) is a continuation of the side section view.

[0027] Figure 7 (a) means Figure 6 (c) is a continuation of the side section view. Figure 7 (b) means Figure 7 (a) is a continuation of the side section view.

[0028] Figure 8 (a) is a side cross-sectional view of the object representing the imaginary surface of the first modified example. Figure 8 (b) is to Figure 8 An enlarged side section view of part (a). Figure 8 (c) represents Figure 8 (a) is a side cross-sectional view of the object after the peeling process.

[0029] Figure 9 (a) is a side cross-sectional view of the object representing the imaginary surface of the second variation. Figure 9 (b) is to Figure 9 An enlarged side section view of part (a). Figure 9 (c) represents Figure 9 (a) is a side cross-sectional view of the object after the peeling process.

[0030] Figure 10 (a) is a side cross-sectional view of the object representing the imaginary surface of the third variation. Figure 10 (b) is to Figure 10 An enlarged side section view of part (a). Figure 10 (c) represents Figure 10 (a) is a side cross-sectional view of the object after the peeling process.

[0031] Figure 11 (a) is a side cross-sectional view of the object representing the imaginary surface of the fourth variation. Figure 11 (b) is to Figure 11 An enlarged side section view of part (a). Figure 11 (c) represents Figure 11 (a) is a side cross-sectional view of the object after the peeling process.

[0032] Figure 12 (a) is a side cross-sectional view of the object representing the imaginary surface of the fifth variation. Figure 12 (b) is a side cross-sectional view of the object representing the imaginary surface of the sixth variation.

[0033] Figure 13 (a) is a side cross-sectional view of the object used to illustrate the first laser processing step. Figure 13 (b) is a side cross-sectional view of the object used to illustrate the second laser processing step.

[0034] Figure 14 This is a side view of the object representing a variation.

[0035] Figure 15 To represent a side view of a semiconductor device, the semiconductor device is shown relative to... Figure 14 The object is obtained by performing an object processing method on the first substrate of the object.

[0036] Figure 16 This is a top view of the object used to illustrate the radial cutting process. Detailed Implementation

[0037] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. The same or equivalent parts are labeled with the same symbols in each drawing, and repeated descriptions are omitted.

[0038] like Figure 1As shown, the object processing system 101 of the embodiment is a system for processing object 11, and includes a laser processing device 1, an object conveying mechanism 40 and a grinding device 60.

[0039] [Laser processing equipment]

[0040] The laser processing apparatus 1 is an apparatus that aligns a focusing position (at least a portion of the focusing area, the focusing point) with an object 11 and irradiates it with a laser, thereby forming a modified region along an imaginary surface inside the object 11. Before grinding by the grinding apparatus 60, the laser processing apparatus 1 irradiates the object 11 with a laser along a processing line, forming one or more rows of modified regions on an imaginary surface inside the object 11. The laser processing apparatus 1 can perform trimming processing on the object 11. Trimming processing is a process used to remove unwanted portions of the object 11. In this embodiment, the X and Y directions are horizontal directions, and the Z direction is a vertical direction.

[0041] The laser processing apparatus 1 includes a stage 2, a laser processing head 3, a Z-axis track 22, a Y-axis track 24, a camera unit 25, a GUI 9, and a control unit 8. The stage 2 is a support unit that supports the object 11. The stage 2 is configured to rotate about an axis parallel to the Z-direction. The object 11 is placed on the stage 2. The stage 2 is driven to rotate by the driving force of a known drive device such as a motor.

[0042] like Figure 1 and Figure 2 As shown, the laser processing head 3 irradiates the object 11 placed on the stage 2 along the Z direction with laser L via the focusing part 33, forming a modified region 12 inside the object 11. The laser processing head 3 can move linearly in the Z direction along the Z-axis track 22 by the driving force of a known drive device such as a motor. The laser processing head 3 can also move linearly in the Y direction along the Y-axis track 24 by the driving force of a known drive device such as a motor. The laser processing head 3 constitutes an irradiation part.

[0043] The laser processing head 3 focuses a transmissive laser L onto the object 11. When the laser L is focused into the interior of the object 11, it is specifically absorbed in the focusing region C, forming a modified region 12 inside the object 11. Furthermore, the focusing region C is either the position where the laser beam intensity is at its highest or a region within a specified range from the center of beam intensity.

[0044] The modified region 12 is a region whose density, refractive index, mechanical strength, and other physical properties differ from the surrounding unmodified region. Examples of modified regions 12 include melt-processed regions, cracked regions, insulation failure regions, and regions with refractive index changes. The modified region 12 contains multiple modified light spots 12s and multiple cracks extending from each modified light spot 12s. Each modified light spot 12s is formed by irradiation with a pulse of laser L.

[0045] The laser processing head 3 includes a light source 31, a spatial light modulator 7, and a focusing section 33. The light source 31 outputs laser light L, for example, via pulse oscillation. Alternatively, the laser processing head 3 may be configured without a light source 31, allowing laser light L to be introduced from outside the laser processing head 3. The spatial light modulator 7 modulates the laser light L output from the light source 31. The focusing section 33 focuses the laser light L modulated by the spatial light modulator 7 and output from the spatial light modulator 7 (i.e., the laser light after passing through the spatial light modulator 7) toward the object 11. The focusing section 33 includes a focusing lens.

[0046] In the spatial light modulator 7, when a signal representing a modulation pattern is input from the control unit 8, the modulation pattern is displayed according to the signal. The modulation pattern is used to modulate the laser L. In the spatial light modulator 7, when the modulation pattern is displayed, the laser L is incident from the outside and reflected outwards, and the laser L is modulated according to the displayed modulation pattern. Thus, by appropriately setting the displayed modulation pattern, the laser L can be modulated (e.g., the intensity, amplitude, phase, polarization, etc. of the laser L). In the laser processing head 3, the laser L output from the light source 31 is incident on the focusing unit 33 via the spatial light modulator 7, and is focused into the object 11 by the focusing unit 33, thereby forming a modified region 12 on the object 11 in the portion corresponding to the focusing region C.

[0047] Back Figure 1 The Z-axis track 22 extends along the Z direction. The Z-axis track 22 is mounted to the laser processing head 3 via the mounting part 21. The Z-axis track 22 moves the laser processing head 3 along the Z direction, thereby moving the focusing position of the laser L along the Z direction. The Y-axis track 24 extends along the Y direction. The Y-axis track 24 is mounted to the Z-axis track 22 via the mounting part 23. The Y-axis track 24 moves the laser processing head 3 along the Y direction, thereby moving the focusing position of the laser L along the Y direction.

[0048] The imaging unit 25 captures an image of the object 11 from the direction of incident of the laser L. The imaging unit 25 includes an alignment camera AC and an imaging unit IR. The alignment camera AC and the imaging unit IR are mounted to the mounting unit 21 together with the laser processing head 3. The alignment camera AC captures a device pattern, for example, using light transmitted through the object 11. The resulting image is provided for alignment of the laser L with respect to the irradiation position of the object 11.

[0049] The control unit 8 is configured as a computer device including a processor, memory, storage, and communication devices. In the control unit 8, software (programs) read into the memory are executed by the processor, and the processor controls the reading and writing of data from the memory and storage, as well as communication via the communication devices. The control unit 8 controls various parts of the laser processing apparatus 1 to perform various functions.

[0050] The control unit 8 controls at least the stage 2, the laser processing head 3, the movement of the laser processing head 3 along the Z-axis track 22, and the movement of the laser processing head 3 along the Y-axis track 24. The control unit 8 controls the rotation of the stage 2, the irradiation of the laser L from the laser processing head 3, and the movement of the focusing position of the laser L. The control unit 8 can perform various controls based on rotation information (hereinafter also referred to as "θ information") related to the amount of rotation of the stage 2. θ information can also be obtained from the drive amount of the drive device that rotates the stage 2, or it can be obtained through other sensors, etc. θ information can be obtained through various known methods.

[0051] The control unit 8 performs a trimming process by rotating the stage 2 while positioning the focusing position on the imaginary surface M in the object 11, and controlling the start and stop of laser L irradiation in the laser processing head 3 based on θ information under AF follow control, thereby forming a modified region 12 along the imaginary surface M. The trimming process is the process performed by the control unit 8 to realize the trimming process.

[0052] GUI 9 displays various information. GUI 9 may include, for example, a touchscreen display. In GUI 9, various settings regarding processing conditions are input through user touch and other operations. GUI 9 constitutes an input unit that receives input from the user. Figure 3 The example shown in (a) is a diagram of an example of the input / output screen of GUI 9. Figure 3 (a) represents an example where four rows of modified regions 12 are formed inside the object 11. Figure 3In (a), SD1, SD2, SD3, and SD4 represent the modified regions 12 that are sequentially moved away from the laser incident surface. The Z-height corresponds to the predetermined position for the formation of the modified region 12. The Z-height is defined as a value that increases from the laser incident surface (0) as it travels from the laser incident surface into the interior of the object 11. The predetermined position for the formation of the modified region 12 is, for example, represented by Z-height × DZ rate ± α. The DZ rate is a predetermined value. α is a correction value set according to various processing conditions, i.e., a value determined empirically. The output corresponds to the output of the laser L when the modified region 12 is formed.

[0053] In GUI 9, the user can input the Z-height, output, and detailed conditions for each of SD1 to SD4. The conditions set in the laser processing apparatus 1 can be based on the semiconductor device 11K (see reference) ultimately obtained after the grinding process described below. Figure 7 The thickness of (b) is set (hereinafter also referred to as "finished thickness"). For example, in the example of setting the processing conditions with the finished thickness set to 50 μm, the user sets the Z height of SD1 in GUI 9 so that the distance from the modified region 12 corresponding to SD1 to the back surface 11b exceeds the finished thickness. Here, taking into account the length of the crack extension, 175 μm is input to the Z height of SD1.

[0054] Furthermore, in GUI 9, the user can input an error detection position, which is an AF wobbling detection position used to suppress wobbling in the event of wobbling exceeding the specified value. The control unit 8, as a monitoring process, calculates the wobbling amount of the AF following control (the amount of optical axis offset when the position of the modified region 12 deviates from the predetermined formation position of the modified region 12), and monitors whether the calculated wobbling amount exceeds the distance in the Z direction from the predetermined formation position of the modified region 12 to the error detection position (hereinafter also referred to as the "wobbling allowable range"). If the control unit 8 determines in the monitoring process that the wobbling amount exceeds the wobbling allowable range, it displays an error indication in GUI 9. The control unit 8 can, in the case of determining in the monitoring process that the wobbling amount exceeds the wobbling allowable range, perform control to turn off the laser, control to fix the focusing unit 33 (fix the actuator), control to forcibly raise the focusing unit 33, or change the control parameters (changes to suppress overshoot).

[0055] Furthermore, in GUI 9, you can input the error detection location, the allowable meandering range, the voltage value of the actuator driving the focusing section 33 in the Z direction, the differential signal or displacement sensor signal value in AF tracking control, and the semiconductor device 11K finally obtained after the following grinding process (see reference). Figure 7 (b) The permissible displacement.

[0056] [Object transport mechanism]

[0057] The object transport mechanism 40 is a mechanism for transporting the object 11 processed by the laser processing apparatus 1 to the grinding apparatus 60. The object transport mechanism 40 includes: an arm 41 for holding the object 11; a slider 42 disposed at the base end of the arm 41; and a track 43 for moving the slider 42 in the horizontal direction. The structure of the object transport mechanism 40 is not particularly limited; any known structure can be used as long as it can transport the object 11 between the laser processing apparatus 1 and the grinding apparatus 60.

[0058] The object transport mechanism 40 includes a control unit 48 and a GUI 49. The control unit 48 is configured as a computer device including a processor, memory, storage, and communication devices. In the control unit 48, software loaded into the memory is executed by the processor, and the processor controls the reading and writing of data from the memory and storage, as well as communication via the communication devices. The control unit 48 controls various parts of the object transport mechanism 40 to perform various functions. The GUI 49 displays various information. The GUI 49 may include, for example, a touchscreen display. In the GUI 49, various settings regarding transport conditions are input through user touch or other operations.

[0059] [Grinding device]

[0060] The grinding apparatus 60 is a device for grinding the object 11 processed by the laser processing apparatus 1. The grinding apparatus 60 removes the area 11Z (see reference 11) from the surface 11a to a predetermined grinding position (predetermined grinding depth) of the object 11. Figure 6 (a) A grinding apparatus. The grinding apparatus 60 includes: a grinding stone, i.e., a grinding wheel 61, capable of rotating at high speed; a base 62 rotatably supporting the grinding wheel; a vertical track 63 for moving the base 62 in the vertical direction; a horizontal track 64 for moving the base 62 in the horizontal direction; a thickness gauge 66 for measuring the thickness of the object 11 being ground; and a platform 67 for placing the object 11 being ground. The platform 67 is configured to rotate about an axis parallel to the vertical direction.

[0061] The grinding apparatus 60 includes a control unit 68 and a GUI 69. The control unit 68 is configured as a computer device including a processor, memory, storage, and communication devices. In the control unit 68, software loaded into the memory is executed by the processor, and the processor controls the reading and writing of data from the memory and storage, as well as communication via the communication devices. The control unit 68 controls various parts of the grinding apparatus 60 to perform various functions. The GUI 69 displays various information. The GUI 69 may include, for example, a touchscreen display. In the GUI 69, various settings regarding grinding conditions are input through user touch or other operations.

[0062] Figure 3 Example (b) shows an example of the input / output screen of GUI 69. In the figure, the stage speed is the speed of stage 67 during grinding by grinding apparatus 60. The grinding wheel speed is the speed of grinding wheel 61 during grinding by grinding apparatus 60. In GUI 69, the pre-processing thickness, finished thickness, stage speed, grinding wheel speed, and detailed conditions can be input. The conditions set in grinding apparatus 60 can be set based on the finished thickness. For example, in GUI 69, assuming a 12-inch wafer thickness, the pre-processing thickness of object 11 is input as 775 μm, and the finished thickness is input as 50 μm. Furthermore, when object 11 is bonded to a 100 μm strip material, in GUI 69, the user can also input the pre-processing thickness of object 11 as 875 μm and the finished thickness as 50 μm.

[0063] Next, the main parts of this embodiment will be further explained.

[0064] like Figure 4 (a) and Figure 4 As shown in (b), the object 11 is, for example, a silicon wafer. The object 11 includes: a surface 11a as a first main surface; and a back surface 11b as the opposite side of the surface 11a. On the back surface 11b of the object 11, a device layer containing a plurality of functional elements is formed. The object 11 is supported on the stage 2 such that the surface 11a faces the laser processing head 3 (i.e., the surface 11a is set as the laser incident surface, and the back surface 11b faces the stage 2).

[0065] The object 11 includes a main body portion R, which is the effective area, and a peripheral portion E, which is the removal area. The main body portion R is a circular portion containing the center of the object 11 when viewed from the Z direction (the thickness direction of the object 11), which is opposite to the surface 11a. The peripheral portion E is a region of the object 11 located further outward than the main body portion R. The peripheral portion E is the portion located at the periphery of the object 11 when viewed from the Z direction; in this case, it is the outer edge portion of the object 11 other than the main body portion R. The peripheral portion E is a ring-shaped portion surrounding the main body portion R. The peripheral portion E includes a bevel portion of the outer edge of the object 11.

[0066] In object 11, an imaginary surface M is provided as a predetermined peeling surface. The imaginary surface M is the surface on which the predetermined modification region 12 is formed. The imaginary surface M is an imaginary region. The imaginary surface M is not limited to a plane, and can also be a curved surface or a three-dimensional surface. The setting of the imaginary surface M can be performed in the control unit 8. The coordinates of the imaginary surface M can also be specified.

[0067] like Figure 5 As shown, a processing line 5 is provided on the object 11. This processing line 5 has multiple parallel lines 5a arranged in a manner that resembles a hypothetical plane M. The processing line 5 is a hypothetical line. The multiple parallel lines 5a are set parallel to each other on the XY plane. The multiple parallel lines 5a extend in a circular shape with different diameters. The extension direction of the parallel lines 5a corresponds to the direction of laser L's travel (scanning direction), i.e., the processing travel direction. The arrangement direction of the parallel lines 5a corresponds to the index direction. The index direction is the direction orthogonal to the extension direction of the parallel lines 5a when viewed from the laser incident surface. For example, the index direction is the direction in which the laser processing head 3 moves parallel to the stage 2 when the focusing position of the laser L is moved. The setting of the processing line 5 can be performed in the control unit 8. The coordinates of the processing line 5 can also be specified.

[0068] like Figure 6 As shown in (a), in this embodiment, a portion of the surface 11a side of the object 11 is designated as the removal region 11Z. Here, the removal region 11Z is a circular plate-shaped region. The removal region 11Z can be determined, for example, based on the pre-processing thickness and the finished thickness input by the user in the GUI 69.

[0069] The imaginary surface M includes: a first surface M11 extending in a direction intersecting with surface 11a; a second surface M12 connected to the back surface 11b side (opposite to surface 11a side) of the first surface M11 via a connecting portion J, and extending in a direction intersecting with the first surface M11; a third surface M13 connected to the back surface 11b side of the second surface M12, and extending in a direction intersecting with the second surface M12; and a fourth surface M14 connected to the back surface 11b side of the third surface M13, and extending in a direction intersecting with the third surface M13.

[0070] The first surface M11 is formed inside the object 11 along the boundary between the peripheral portion E and the main body portion R. The first surface M11 has a shape corresponding to the circumferential surface of a cylinder. The surface 11a side of the first surface M11 reaches the surface 11a. The second surface M12 has a shape corresponding to the circumferential surface of a frustum of a cone. The second surface M12 is an inclined surface that slopes radially inward relative to the Z direction as it approaches the surface 11a. The third surface M13 has a shape corresponding to the circumferential surface of a frustum of a cone. The third surface M13 is an inclined surface that slopes radially inward relative to the Z direction as it approaches the surface 11a. The fourth surface M14 is an annular surface and is a plane parallel to the XY plane. The radially outer side of the fourth surface M14 reaches the side surface of the object 11.

[0071] like Figure 6 As shown in (b), when observing a cross-section along the Z direction containing the central axis of object 11 (hereinafter referred to as the "cross-sectional view along the Z direction"), the first angle θ1 formed by the first surface M11 and the second surface M12, the second angle θ2 formed by the surface 11a and the second surface M12, and the third angle θ3 formed by the second surface M12 and the third surface M13 are obtuse angles. In other words, the first angle θ1 is the obtuse angle formed by the first surface M11 and the second surface M12, the second angle θ2 is the obtuse angle formed by the surface 11a and the second surface M12, and the third angle θ3 is the obtuse angle formed by the second surface M12 and the third surface M13. The first angle θ1 is smaller than the second angle θ2. The first angle θ1 is smaller than the third angle θ3. The connection J between the first surface M11 and the second surface M12 is provided in the object 11 in the removed area 11Z. Furthermore, the cross-sectional view along the Z direction corresponds to the cross-sectional view intersecting the surface 11a.

[0072] In the object processing method of this embodiment, such as Figure 6 As shown in (c), a laser L is irradiated onto the object 11 by the laser processing apparatus 1, forming a modified region 12 along the imaginary surface M inside the object 11 (laser processing step). Specifically, in the laser processing step, the laser L is irradiated onto the object 11 by the laser processing head 3, and the laser L is focused onto a processing line 5 set on the imaginary surface M inside the object 11. While rotating the stage 2 to move the focusing position of the laser L along the processing line 5, AF tracking control is performed to make the focusing position follow the displacement of the surface 11a, which is the laser incident surface. This laser processing is repeated on all the processing lines 5 on the imaginary surface M. Thus, a modified region 12 is formed on the object 11 along the imaginary surface M. Furthermore, there is no particular limitation on the order of laser processing on each surface of the imaginary surface M. The order of laser processing on the first surface M11, the second surface M12, the third surface M13, and the fourth surface M14 of the imaginary surface M is different.

[0073] Next, as Figure 7 As shown in (a), after the laser processing step, external stress is applied to the workpiece 11, and the modified region 12 covering the imaginary surface M is set as the boundary, and a portion of the peripheral portion E is peeled off (peeling process). Next, based on the transport conditions input via GUI 49, the workpiece 11 is transported from the laser processing apparatus 1 to the grinding apparatus 60 by the workpiece transport mechanism 40. Based on the grinding conditions input via GUI 69, the grinding apparatus 60 performs a grinding process (removal process). That is, as... Figure 7 As shown in (b), the removal area 11Z of the object 11 after the stripping process is removed by grinding with a grinding wheel 61. As a result, a semiconductor device 11K is obtained (manufactured). Furthermore, planarization processing can also be performed by laser processing or etching between the stripping process and the removal process.

[0074] Here, in the object processing method of this embodiment, by defining the first angle θ1 and the second angle θ2 as described above, for example, when peeling off the peripheral portion E of the object 11 with the modified region 12 covering the imaginary surface M as the boundary, the connection portion J (refer to the imaginary surface M) on the peeled surface can be made possible. Figure 6 A portion of the object that was not completely peeled off is easily concentrated around the area corresponding to (a) , namely the residual portion 11P (hereinafter also simply referred to as "residual portion 11P"). The peeling surface is the surface corresponding to the imaginary surface M of the object 11 after the peripheral portion E has been peeled off. The peeling surface is the surface corresponding to the boundary between the object 11 and the peripheral portion E.

[0075] Furthermore, by defining the first angle θ1 and the second angle θ2 as described above, for example, in the formation of the modified region 12 by a laser processing step, the residual portion 11P can be easily concentrated around the periphery of the portion corresponding to the connecting portion J. In the illustrated example, the residual portion 11P is randomly and locally retained in the annular groove formed by the peeling surface H11 corresponding to the first surface M11 and the peeling surface H12 corresponding to the second surface M12. The reason for this is that when the removal region 11Z is removed, due to the way external stress is applied, the residual portion 11P is more likely to remain around the periphery of the portion corresponding to the connecting portion J.

[0076] Then, since the connecting portion J is provided in the removal area 11Z, the residual portion 11P is also removed when the removal area 11Z is removed. That is, by shifting the position where the residual portion 11P is concentrated in the Z direction to a position shallower than the predetermined grinding position, the residual portion 11P can be prevented from remaining on the workpiece 11 after the grinding process. Therefore, the adverse effects of the residual portion on the quality of the processed workpiece 11, i.e., the semiconductor device 11K, can be prevented. Therefore, the quality deterioration of the processed workpiece 11 can be prevented.

[0077] In the object processing method, the object 11 is configured to include a peripheral portion E and a main body portion R, and a first surface M11 is formed inside the object 11 along the boundary between the peripheral portion E and the main body portion R. In this case, at least a portion of the peripheral portion E can be peeled off by using the modified region 12 that extends throughout the imaginary surface M as the boundary.

[0078] The object processing method includes: a peeling step, which peels off the peripheral portion E with the modified region 12 as the boundary after the laser processing step; and a removal step, which removes the removal region 11Z of the object 11 after the laser processing step. In this case, the peeling of a portion of the object 11 and the removal of the removal region 11Z can be performed. In the object processing method, the removal step is a grinding step that removes the material by grinding the removal region 11Z. In this case, the removal step can be specifically implemented.

[0079] In the object processing method, the imaginary surface M includes a third surface M13. In a cross-sectional view along the Z direction, the third angle θ3 formed by the second surface M12 and the third surface M13 is an obtuse angle, and the first angle θ1 is smaller than the third angle θ3. In this case, for example, when a portion of the object 11 is peeled off with the modified region 12 as the boundary, and / or when the modified region 12 is formed by a laser processing step, the residual portion 11P can be easily concentrated and retained around the periphery of the part corresponding to the connecting portion J on the peeled surface. Furthermore, the position of the first surface M11 in the object 11 can be easily adjusted according to the user's requirements without changing the first angle θ1.

[0080] In this embodiment, the fourth surface M14 formed near the back surface 11b of the object 11 is better the closer it is to the object 11, and it can also be configured to overlap the back surface 11b at least partially. In this case, the object 11 can be further thinned by a subsequent grinding process. Alternatively, the fourth surface M14 can also be configured to be separated from the back surface 11b of the object 11 by a certain distance or more. In this case, it is possible to suppress the formation of cracks (so-called bottom cracks) that do not follow the imaginary surface toward the back surface 11b of the object 11.

[0081] [Variation Example]

[0082] The present invention is not limited to the above-described embodiments.

[0083] In the above embodiments, the imaginary surface M is not particularly limited, and various methods can be used as illustrated below.

[0084] Figure 8 (a) is a side cross-sectional view of object 11 representing the imaginary surface M of the first modified example. Figure 8As shown in (a), the imaginary surface M of the first variation differs in the following aspects: relative to the imaginary surface M of the above embodiment (refer to...) Figure 6 (a) includes a first surface M21 replacing the first surface M11. The first surface M21 is a surface with a shape corresponding to the circumferential surface of a frustum. The first surface M21 is an inclined surface that slopes radially inward relative to the Z direction as it approaches surface 11a. The surface 11a side of the first surface M21 reaches surface 11a. The second surface M12 is connected to the back surface 11b side of the first surface M21 via a connecting portion J2. Figure 8 As shown in (b), in the cross-sectional view along the Z direction, the first angle θ21 formed by the first surface M21 and the second surface M12 is an obtuse angle. In other words, the obtuse angle formed by the first surface M21 and the second surface M12 is the first angle θ21. The first angle θ21 is smaller than the second angle θ2. The first angle θ21 is smaller than the third angle θ3. The connection J between the first surface M21 and the second surface M12 is provided in the removed area 11Z of the object 11.

[0085] When processing an object 11 with a first modified surface M, a laser L is irradiated onto the object 11 by a laser processing apparatus 1, forming a modified region 12 along the imaginary surface M inside the object 11. Then, as... Figure 8 As shown in (c), external stress is applied to the object 11, and the modified region 12 covering the imaginary surface M is set as the boundary, and a portion of the peripheral part E is peeled off. In this case, the residual part 11P can be easily concentrated and retained around the part corresponding to the connection J2 of the imaginary surface M in the peeled surface. The above-mentioned effect can also be achieved in such a processing method.

[0086] Figure 9 (a) is a side cross-sectional view of object 11 representing the imaginary surface M of the second modified example. Figure 9 As shown in (a), the imaginary surface M of the second variation differs in the following aspects: relative to the imaginary surface M of the first variation described above (refer to...) Figure 8 (a) includes a second face M32 in place of the second face M12, the third face M13 and the fourth face M14.

[0087] The second surface M32 is an inclined surface that slopes towards surface 11a relative to the horizontal direction as it travels radially inward. The second surface M32 is connected to the back surface 11b side of the first surface M21 via the connecting portion J3 and extends in a direction intersecting the first surface M21. The radially outer side of the second surface M32 is located near the back surface 11b of the object 11 and reaches the side surface of the object 11. Figure 9As shown in (b), in the cross-sectional view along the Z direction, the first angle θ31 formed by the first surface M21 and the second surface M32, and the second angle θ32 formed by the second surface M32 and the surface 11a are obtuse angles. In other words, the first angle θ31 is the obtuse angle formed by the first surface M21 and the second surface M32, and the second angle θ32 is the obtuse angle formed by the second surface M32 and the surface 11a. The first angle θ31 is smaller than the second angle θ32. The connection portion J3 between the first surface M21 and the second surface M32 is provided in the removed area 11Z of the object 11.

[0088] When processing an object 11 with a second modified surface M, a laser L is irradiated onto the object 11 by the laser processing apparatus 1, forming a modified region 12 along the imaginary surface M inside the object 11. Then, as... Figure 9 As shown in (c), external stress is applied to the object 11, and the modified region 12 covering the imaginary surface M is set as the boundary, and a portion of the peripheral portion E is peeled off. In this case, the residual portion 11P can be easily concentrated and retained around the part corresponding to the connection portion J3 of the imaginary surface M in the peeled surface. The above-mentioned effect can also be achieved in such a processing method.

[0089] Figure 10 (a) is a side cross-sectional view of object 11 representing the imaginary surface M of the third modified example. Figure 10 As shown in (a), the imaginary surface M of the third variation differs in the following aspects: relative to the imaginary surface M of the first variation described above (refer to...) Figure 8 (a) includes a second face M42 in place of the second face M12 and the third face M13.

[0090] The second surface M42 is an inclined curved surface that approaches surface 11a relative to the horizontal plane as it travels radially inward, and in a cross-sectional view along the Z direction, it curves in a manner that bulges towards the back surface 11b. The radially inward side of the second surface M42 is connected to the back surface 11b side of the first surface M21 via a connecting portion J4. The radially outward side of the second surface M42 is connected to the radially inward side of the fourth surface M14. Figure 10 As shown in (b), in the cross-sectional view along the Z direction, the first angle θ41 formed by the first surface M21 and the second surface M42, and the second angle θ42 formed by the second surface M42 and the surface 11a are obtuse angles. In other words, the first angle θ41 is the obtuse angle formed by the first surface M21 and the second surface M42, and the second angle θ42 is the obtuse angle formed by the second surface M42 and the surface 11a. The first angle θ41 is smaller than the second angle θ42. The connection portion J4 between the first surface M21 and the second surface M42 is provided in the removed area 11Z of the object 11.

[0091] Furthermore, since the second surface M42 is curved, in a cross-sectional view along the Z direction, the angle between the first surface M21 and the second surface M42 can be approximated, for example, as the angle between the first surface M21 and the tangent direction of the second surface M42 passing through its midpoint. Similarly, since the second surface M42 is curved, in a cross-sectional view along the Z direction, the angle between the second surface M42 and surface 11a can be approximated as the angle between the tangent direction of the second surface M42 passing through its midpoint and surface 11a. The same applies to the curved surfaces described below.

[0092] When processing an object 11 with a third modified surface M, a laser L is irradiated onto the object 11 by a laser processing apparatus 1, forming a modified region 12 along the imaginary surface M inside the object 11. Then, as... Figure 10 As shown in (c), external stress is applied to the object 11, and the modified region 12 covering the imaginary surface M is set as the boundary, and a portion of the peripheral portion E is peeled off. In this case, the residual portion 11P can be easily concentrated and retained around the portion corresponding to the connection J4 of the imaginary surface M in the peeled surface. The above-mentioned effect can also be achieved in such a processing method.

[0093] Figure 11 (a) is a side cross-sectional view of object 11 representing the imaginary surface M of the fourth modified example. Figure 11 As shown in (a), the imaginary surface M of the fourth variation differs from the imaginary surface M of the first variation described above (refer to...). Figure 8 (a) includes the first face M51 and the second face M52 in place of the first face M21, the second face M12, the third face M13 and the fourth face M14.

[0094] The first surface M51 differs from the first surface M21 at a point located radially outward relative to it; otherwise, it is constructed identically to the first surface M21. The second surface M52 is an inclined curved surface that approaches surface 11a relative to the horizontal plane as it travels radially inward, and in a cross-sectional view along the Z direction, curves in a manner that bulges towards the rear surface 11b. The radially inward side of the second surface M52 is connected to the rear surface 11b side of the first surface M51 via a connecting portion J5. The radially outward side of the second surface M52 is located near the rear surface 11b of the object 11 and reaches the side surface of the object 11. Figure 10 As shown in (b), in the cross-sectional view along the Z direction, the first angle θ51 formed by the first surface M51 and the second surface M52, and the second angle θ52 formed by the second surface M52 and the surface 11a are obtuse angles. The first angle θ51 is smaller than the second angle θ52. The connection portion J5 between the first surface M51 and the second surface M52 is provided in the object 11 in the removed area 11Z.

[0095] When processing an object 11 with a fourth modified surface M, a laser L is irradiated onto the object 11 by a laser processing apparatus 1, forming a modified region 12 along the imaginary surface M inside the object 11. Then, as... Figure 11 As shown in (c), external stress is applied to the object 11, and the modified region 12 covering the imaginary surface M is set as the boundary, and a portion of the peripheral portion E is peeled off. In this case, the residual portion 11P can be easily concentrated and retained around the periphery of the portion corresponding to the connection J5 of the imaginary surface M in the peeled surface. The above-mentioned effect can also be achieved in such a processing method.

[0096] Figure 12 (a) is a side cross-sectional view of object 11 representing the imaginary surface M of the fifth variation. For example... Figure 12 As shown in (a), the imaginary surface M of the fifth variation differs in the following aspects: relative to the imaginary surface M of the third variation described above (refer to...) Figure 10 (a) includes the second face M62 and the fourth face M64 in place of the second face M42 and the fourth face M14.

[0097] The second surface M62 is an inclined curved surface that approaches surface 11a relative to the horizontal plane as it travels radially inward, and in a cross-sectional view along the Z direction, it curves in a manner that bulges towards the back surface 11b. The radially inward side of the second surface M62 is connected to the back surface 11b side of the first surface M21 via a connecting portion J6. The radially outward side of the second surface M62 overlaps (connects) with the back surface 11b of the object 11. The fourth surface M64 is an annular surface and is a plane parallel to the XY plane. The radially inward side of the fourth surface M64 is connected to the radially outward side of the second surface M62.

[0098] In the cross-sectional view along the Z direction, the first angle formed by the first surface M21 and the second surface M62, and the second angle formed by the second surface M62 and the surface 11a, are obtuse angles. In other words, the obtuse angle formed by the first surface M21 and the second surface M62 is the first angle, and the obtuse angle formed by the second surface M62 and the surface 11a is the second angle. The first angle is smaller than the second angle. The connection portion J6 between the first surface M21 and the second surface M62 is provided in the removal area 11Z of the object 11. When the above-described laser processing and peeling process are performed on the object 11 with the imaginary surface M provided in the fifth modified example, the residual portion 11P can be easily concentrated and retained around the periphery of the portion corresponding to the connection portion J6 of the imaginary surface M in the peeled surface. The above-described effect can also be achieved in such a processing method.

[0099] Figure 12 (b) is a side cross-sectional view of object 11 representing the imaginary surface M of the sixth variation. Figure 12As shown in (b), the imaginary surface M of the sixth variation differs in the following aspects: relative to the imaginary surface M of the fourth variation described above (refer to...) Figure 11 (a) includes the second face M72 in place of the second face M52.

[0100] The second surface M72 is an inclined surface that approaches the surface 11a relative to the horizontal plane as it travels radially inward, and in a cross-sectional view along the Z direction, it is curved in a manner that bulges toward the back surface 11b. The radially inward side of the second surface M72 is connected to the back surface 11b side of the first surface M51 via the connecting portion J7. The radially outward side of the second surface M72 overlaps (connects) with the back surface 11b of the object 11.

[0101] In the cross-sectional view along the Z direction, the first angle formed by the first surface M51 and the second surface M72, and the second angle formed by the second surface M72 and the surface 11a, are obtuse angles. In other words, the obtuse angle formed by the first surface M51 and the second surface M72 is the first angle, and the obtuse angle formed by the second surface M72 and the surface 11a is the second angle. The first angle is smaller than the second angle. The connection portion J7 between the first surface M51 and the second surface M72 is provided in the removal area 11Z of the object 11. When the above-described laser processing and peeling processes are performed on the object 11 with the imaginary surface M provided in the sixth modified example, the residual portion 11P can be easily concentrated and retained around the periphery of the portion corresponding to the connection portion J7 of the imaginary surface M in the peeled surface. The above-described effect can also be achieved in the most important processing method.

[0102] In the above embodiments, the laser processing step may also include: a first laser processing step, in which a modified region 12 is formed by irradiating a laser L along at least a first portion of the imaginary surface M under first processing conditions; and a second laser processing step, in which, after the first laser processing step, a modified region 12 is formed by irradiating a laser L along the imaginary surface M under second processing conditions. The first processing conditions may also be conditions in which multiple cracks contained in the modified region 12 are discontinuously connected, and the second processing conditions may be conditions in which the multiple cracks contained in the modified region 12 formed by the first and second laser processing steps are interconnected after the second laser processing step and extend throughout the entire region of the imaginary surface M. An example will be described below.

[0103] First, relative to the setting Figure 6 The object 11, which is an imaginary surface M as shown in (a), is irradiated with laser L along the second surface M12 and the third surface M13, which are the first part of the imaginary surface M, under the first processing conditions. Thus, as Figure 13As shown in (a), a modified region 12a (first laser processing step) is formed along the second surface M12 and the third surface M13 inside the object 11. Specifically, in the first laser processing step, a laser L is irradiated onto the object 11 by the laser processing head 3 under first processing conditions, causing the laser L to be focused onto a processing line 5 set on the second surface M12 and the third surface M13 in the imaginary surface M inside the object 11. While rotating the stage 2 to move the focusing position of the laser L along the processing line 5, AF tracking control is performed to make the focusing position follow the displacement of the surface 11a, which is the laser incident surface. This laser processing is repeated on all the processing lines 5 on the second surface M12 and the third surface M13. As a result, a modified region 12a is formed along the second surface M12 and the third surface M13.

[0104] The first processing condition is that the multiple cracks contained in the modified region 12a are discontinuously connected. The first processing condition is that the processed state of the modified region 12a on the second surface M12 and the third surface M13 after the first laser processing step changes to the first slicing state. The first slicing state is a stealth state where at least a portion of the multiple cracks contained in the modified region 12a are not connected to each other in both the processing direction and the index direction (the direction intersecting the processing direction). The first slicing state can also be a half-cut state where at least a portion of the multiple cracks contained in the modified region 12a are not connected to each other in the index direction. That is, in the first laser processing step, along the second surface M12 and the third surface M13 of the imaginary surface M, a modified region 12a containing multiple cracks is formed with discontinuous connections (here, the modified region 12a in the first slicing state). The laser processing of the first laser processing step is also called dot-line processing.

[0105] Next, in the laser processing procedure, such as Figure 13As shown in (b), after the first laser processing step, a modified region 12b is formed by irradiating the first surface M11 and the fourth surface M14 of the imaginary surface M under second processing conditions (second laser processing step). Specifically, in the second laser processing step, the laser L is irradiated onto the object 11 by the laser processing head 3 under second processing conditions, causing the laser L to be focused on the processing line 5 set on the first surface M11 and the fourth surface M14, excluding the first part of the imaginary surface M inside the object 11. At the same time, while rotating the stage 2 to move the focusing position of the laser L along the processing line 5, AF tracking control is performed to make the focusing position follow the displacement of the surface 11a, which is the laser incident surface. This laser processing is repeated on all the processing lines 5 on the first surface M11 and the fourth surface M14. As a result, the modified region 12b is formed along the first surface M11 and the fourth surface M14.

[0106] The second processing condition is that the multiple cracks contained in the modified regions 12a and 12b formed by the first and second laser processing steps are interconnected after the second laser processing step and extend to the entire region of the imaginary surface M. The second processing condition is as follows: the processed state of the modified region 12, which covers the entire region of the imaginary surface M after the second laser processing step, becomes a second slice state. The second slice state is a full-cut state in which the multiple cracks contained in the modified region 12 extend and are interconnected in the processing direction and in directions intersecting the processing direction. That is, in the second laser processing step, the modified region 12b in the second slice state is formed along the first surface M11 and the fourth surface M14, and the modified region 12a in the first slice state, which was formed in the first laser processing step, changes to the modified region 12c in the second slice state as the cracks extend with the formation of the modified region 12b.

[0107] The slice-hidden (SST) state is characterized by the following: the crack does not extend from the multiple modified light spots (marks) 12s contained in the modified region 12, or the crack is not connected. The slice-hidden state is a state in which only the modified light spots 12s can be observed through the camera unit 25. In the slice-hidden state, since there is no extension of cracks, even if the number of processing lines is increased, the state will not change to the full slice state.

[0108] The semi-slice (SHC) state is as follows: cracks extending from multiple refining spots 12s contained in the refining region 12 extend along parallel lines 5a (processing travel direction). The full slice (SFC) state is as follows: cracks extending from multiple refining spots 12s contained in the refining region 12 extend and connect with each other along multiple parallel lines 5a and in directions intersecting with parallel lines 5a. The full slice state is as follows: cracks extending from refining spots 12s cross multiple parallel lines 5a and are connected. The full slice state is a state generated by the connection of cracks crossing multiple parallel lines 5a, and therefore will not occur when the refining region 12 is formed by irradiating laser L along one parallel line 5a. In order for the full slice state to occur, the semi-slice state becomes necessary and indispensable as a processing state when the refining region 12 is formed by irradiating laser L along one parallel line 5a.

[0109] In this object processing method, a first laser processing step forms multiple cracks that are discontinuously connected along a first portion of an imaginary surface M. A subsequent second laser processing step connects these multiple cracks, extending them to the entire area of ​​the imaginary surface M. In this case, the discontinuous connection of multiple cracks allows for the appropriate guidance of the crack extension throughout the entire area of ​​the imaginary surface M. Therefore, compared to the case where cracks extending throughout the entire area of ​​the imaginary surface M are formed in a single laser processing step, the unintentional formation of cracks not along the imaginary surface M (initial cracks extending in directions other than those along the imaginary surface M) on the object 11 can be suppressed.

[0110] In the above embodiment, for example, object 11 (see reference) is used as a silicon wafer. Figure 4 (b) etc.), but the object is not specifically limited, such as Figure 14 As shown, an object 111 can also be used as a bonding wafer. Object 111 has a first substrate 151 and a second substrate 152. The first substrate 151 and the second substrate 152 correspond to object 11.

[0111] A first device layer 161 comprising multiple functional elements is formed on the back side 151b, which is the main surface of the first substrate 151. A second device layer 162 comprising multiple functional elements is formed on the surface 152a, which is the main surface of the second substrate 152. The first substrate 151 and the second substrate 152 are bonded via the first device layer 161 and the second device layer 162. In such a wafer-mounted object 111, for example, after peeling off the peripheral portion E with the modified region 12 covering the imaginary surface M as the boundary, the effect of suppressing damage to the outer periphery is achieved compared to an object 11 having a single substrate.

[0112] For example, in object 111, when the peripheral portion E is peeled off with the modified region 12 covering the imaginary surface M formed on the first substrate 151 as the boundary, the crack can extend radially inward from the bonding surface of the first device layer 161 and the second device layer 162, cross the pattern of the first device layer 161 and reach the modified region 12 inside the first substrate 151, and extend along the modified region 12.

[0113] Furthermore, the imaginary surface M formed near the back surface 151b of the first substrate 151 in the object 111 should be as close to the object 11 as possible, and can also be configured such that at least a portion overlaps with the back surface 151b. In this case, cracks extending from the bonding surface of the first device layer 161 and the second device layer 162 to the modified region 12 of the first substrate 151 can be suppressed from progressing to the central portion in the thickness direction of the first substrate 151.

[0114] Figure 15 To show a side view of semiconductor device 111K, semiconductor device 111K is viewed relative to... Figure 14 The first substrate 151 of the object 111 is obtained by performing the object processing method described above. In the semiconductor device 111K, the surface 71 on the opposite side of the second substrate 152 side of the first substrate 151 has an inclined surface 72 at its end.

[0115] The inclined surface 72 is inclined in a manner that it tilts towards the rear surface 151b as it travels radially outward. The inclined surface 72 extends in a ring shape when viewed from the Z direction. The inclined surface 72 illustrated is inclined in stages and includes multiple surfaces with different tilt angles. Specifically, the inclined surface 72 includes: a first inclined surface 72A corresponding to the second surface M12 of the imaginary surface M, and a second inclined surface 72B corresponding to the third surface M13 of the imaginary surface M. Additionally, the surface 71 includes: a circular central surface 73 continuous with the radially inner side of the inclined surface 72; and a ring-shaped surface, i.e., an outer edge surface 74, continuous with the radially outer side of the inclined surface 72. The central surface 73 corresponds to the polished surface being polished in the polishing process. The outer edge surface 74 corresponds to the fourth surface M14 of the imaginary surface M. In such a semiconductor device 11K, a wider effective area of ​​the device can be ensured. Furthermore, the semiconductor device 111K is not limited to including the inclined surface 72; there are also cases where the inclined surface 72 is replaced by an inclined surface and / or an inclined curved surface in accordance with the imaginary surface M.

[0116] In the above embodiments, such as Figure 16As shown, a radial cutting process (peripheral processing process) can also be included, in which a modified region 12 is formed by irradiating a laser L along a processing line 5, i.e., a radial line 5h, extending radially from the inner side to the outer side of the peripheral region E. The radial line 5h can be set in GUI 9. The radial line 5h is an imaginary line. The coordinates of the radial line 5h can also be specified. The radial line 5h is the predetermined radial cutting line for the formation of the modified region caused by the predetermined radial cutting process. When viewed from the laser incident surface, the radial line 5h extends in a straight line (radially) along the radial direction of the object 11. In the illustrated example, when viewed from the Z direction, multiple radial lines 5h are set in such a way that the peripheral region E is equally divided in the circumferential direction (in this case, divided into four parts).

[0117] The radial cutting process is a process used to separate unwanted portions removed by trimming. For example, in the radial cutting process, after the second laser processing step and before the peeling step, with the stage 2 not rotated and the focusing position positioned along the radial lines 5h in the object 11, the start and stop of laser L irradiation in the laser processing head 3 are controlled under AF follow-up control, and the focusing position of the laser L is moved along the radial lines 5h. This laser processing is repeated on all radial lines 5h, thereby forming one or more rows of modified regions 12 along the radial lines 5h in the Z direction. According to this radial cutting process, the peripheral portion E can be reliably peeled off.

[0118] In the above embodiments, when the imaginary surface M comprises multiple surfaces, the processing order of laser processing relative to these multiple surfaces is not particularly limited, and can be different orders. In the above embodiments, the indexing direction is not particularly limited, and can be a direction from the radial inside to the radial outside, or a direction from the radial outside to the radial inside, or these directions can be appropriately combined depending on the situation.

[0119] In the above embodiments, there are no particular limitations on the type, shape, size, number and orientation of crystal positions of the object 11, or orientation of the main surface of the object 11. In the above embodiments, the vicinity of the back surface 11b may include, for example, positions close to the back surface 11b, positions near the back surface 11b, and positions around the back surface 11b, and may also include positions on the back surface 11b and positions overlapping with the back surface 11b.

[0120] In the above embodiment, the surface 11a of the object 11 is used as the laser incident surface, but the back surface 11b of the object 11 can also be used as the laser incident surface. In the above embodiment, the modified region 12 can also be, for example, a crystalline region, a recrystallized region, or a gettering region formed inside the object 11. The crystalline region is the region that maintains the structure of the object 11 before processing. The recrystallized region is the region that temporarily evaporates, plasma-enhances, or melts, and then solidifies into a single crystal or polycrystalline structure upon re-solidification. The gettering region is the region that concentrates and captures impurities such as heavy metals, and can be formed continuously or intermittently. The above embodiment can also be applied to processes such as ablation.

[0121] The structures in the above-described embodiments and modifications are not limited to the materials and shapes described above, and can be applied to various materials and shapes. Furthermore, the structures in the above-described embodiments or modifications can be arbitrarily applied to the structures in other embodiments or modifications.

[0122] Explanation of symbols

[0123] 5…processing line, 5a…parallel line, 5h…radial line, 11…object (first substrate, second substrate), 11a…surface (main surface), 11b…back side (main surface), 11Z…removal area, 12, 12a, 12b, 12c…modification area, 12s…modification spot, 111…object, 161…first device layer, 162…second device layer, E…peripheral portion, H11, H12…peeling surface, J, J2, J3 J4, J5, J6, J7… connecting part, L… laser, M… imaginary surface, M11, M21, M51… first surface, M12… second surface (first part), M32, M42, M52, M62, M72… second surface, M13… third surface (first part), R… main body, θ1, θ21, θ31, θ41, θ51… first angle, θ2, θ32, θ42, θ52… second angle, θ3… third angle.

Claims

1. A method for processing an object, wherein, It is a method of processing objects. It includes: a laser processing step, which forms a modified region along an imaginary surface inside the object by irradiating the object with a laser. The object has a surface, and a portion of the surface side is designated as a removed area. The imaginary surface includes: a first surface that extends in a direction intersecting the surface; And a second surface, which is connected to the opposite side of the surface side of the first surface via a connecting portion, and extends in a direction intersecting the first surface. In a cross-sectional view intersecting the surface, the first angle formed by the first surface and the second surface, and the second angle formed by the surface and the second surface, are obtuse angles. The first angle is smaller than the second angle. The connecting portion is provided in the object within the removal area.

2. The object processing method according to claim 1, wherein, have: A peeling process, which, after the laser processing process, sets the modified region covering the imaginary surface as a boundary and peels off a portion of the object; and The removal process, which is performed after the laser processing process, removes the removal area of ​​the object.

3. The object processing method according to claim 2, wherein, The removal process involves grinding the removal area.

4. The object processing method according to claim 1 or 2, wherein, The imaginary surface includes a third surface that connects to the opposite side of the surface side of the second surface and extends in a direction intersecting the second surface. In a cross-sectional view intersecting the surface, the third angle formed by the second surface and the third surface is an obtuse angle. The first angle is smaller than the third angle.

5. The object processing method according to claim 1 or 2, wherein, The object is configured to include: a peripheral portion located at the periphery when viewed from a direction opposite to the surface; and a main body portion located further inward than the peripheral portion. The first surface is formed inside the object along the boundary between the peripheral portion and the main body portion.

6. The object processing method according to claim 5, wherein, It includes a peripheral processing step, in which the laser is irradiated along radial lines extending radially from the inner side to the outer side of the peripheral portion to form the modified region.

7. The object processing method according to claim 1 or 2, wherein, The object has a first substrate and a second substrate. A first device layer is formed on the main surface of the first substrate. A second device layer is formed on the main surface of the second substrate. The first substrate and the second substrate are bonded together via the first device layer and the second device layer.

8. The object processing method according to claim 1 or 2, wherein, The laser processing step has the following characteristics: A first laser processing step, wherein the modified region is formed by irradiating at least a first portion of the imaginary surface with the laser under first processing conditions; and The second laser processing step, following the first laser processing step, involves irradiating the imaginary surface with the laser under second processing conditions to form the modified region. The first processing condition is that the modified region contains multiple intermittently connected cracks. The second processing condition is a condition in which the multiple cracks contained in the modified region formed by the first and second laser processing steps are interconnected after the second laser processing step and extend to the entire area of ​​the imaginary surface.

Images