Device chip manufacturing method and laser processing apparatus

Abstract

To suppress the damage of a device and the occurrence of the division failure of a workpiece even when a street is deformed.SOLUTION: The method of manufacturing the device chip includes the first processing step S10 of forming the modified layer 16 inside the workpiece 10 by irradiating the workpiece 10 with the laser beam along the first division line, the second processing step S12 of forming the modified layer 16 inside the workpiece 10 by irradiating the workpiece 10 with the laser beam along the adjacent division line adjacent to the first division line, and the step of, after performing the first processing step S10, and a position coordinates acquiring step S11 of acquiring position coordinates of a key pattern P formed in a predetermined region of the workpiece 10 along an extending direction of the adjacent division line, wherein in the second processing step S12, the adjacent division line is corrected based on the position coordinates of the key pattern P, and the laser beam is applied along the corrected adjacent division line Lc.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a device chip and a laser processing apparatus. [Background technology]

[0002] As a method for dividing a plate-shaped workpiece such as a semiconductor wafer into device chips, a method is known in which a laser beam that is transparent to the workpiece is irradiated into the inside of the workpiece to form a modified layer, and then an external force is applied starting from the modified layer to divide the workpiece, thereby manufacturing device chips (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3408805 Summary of the Invention [Problem to be solved by the invention]

[0004] In the device chip manufacturing method described in Patent Document 1, streets formed in a workpiece are used as dividing lines, and modified layers are formed along the dividing lines. When the modified layers are formed, the mechanical strength of the surrounding area around the modified layers is reduced, causing the workpiece to expand in a direction perpendicular to the direction of the streets, which can result in deformation, such as bending of the planned streets. If a laser beam is irradiated linearly along such curved streets, the laser beam may be irradiated onto the device or other device, which not only damages the product but also prevents the formation of an appropriate modified layer inside the wafer, potentially resulting in division defects.

[0005] The present invention provides a device chip manufacturing method and a laser processing apparatus that can prevent damage to the device and defective division of the workpiece even when the street is deformed. [Means for solving the problem]

[0006] One aspect of the present invention is A method of manufacturing device chips, comprising: dividing a workpiece, on which a plurality of devices are formed in an area partitioned by a plurality of planned dividing lines, along the planned dividing lines to manufacture device chips, a first processing step of irradiating the workpiece with a laser beam having a wavelength that can transmit the workpiece along a first planned dividing line to form a modified layer inside the workpiece; a second processing step in which, after the first processing step is performed, the laser beam is irradiated along an adjacent dividing line adjacent to the first dividing line processed in the first processing step to form a modified layer inside the workpiece; a position coordinate acquiring step of acquiring position coordinates of a key pattern formed in a predetermined region of the workpiece along an extending direction of the adjacent planned dividing line after the first processing step is performed, The second processing step includes: The adjacent planned division line is corrected based on the position coordinates of the key pattern acquired in the position coordinate acquisition step, and the laser beam is irradiated along the corrected adjacent planned division line.

[0007] Another aspect of the present invention is A laser processing apparatus for processing a workpiece by irradiating a laser beam onto the workpiece, the workpiece having a plurality of devices formed in areas partitioned by a plurality of planned division lines, a holding table for holding the workpiece; a laser irradiation unit that irradiates the workpiece with the laser beam having a wavelength that is transparent to the workpiece to form a modified layer inside the workpiece; a moving unit that moves the workpiece held on the holding table and the focal point of the laser beam relatively; an acquisition unit for acquiring position coordinates of a key pattern formed in a predetermined area of ​​the workpiece; a control unit for controlling the laser processing device, The control unit a position coordinate acquisition unit for acquiring position coordinates of the key pattern acquired by the acquisition unit; an irradiation position correction unit that corrects the planned division line based on the acquired position coordinates and irradiates the laser beam along the corrected planned division line, Laser processing equipment. [Effects of the Invention]

[0008] According to the present invention, even if the street is deformed, damage to the device and defective separation of the workpiece can be suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of a laser processing device 1. As shown in FIG. [Figure 2] FIG. 2 is a perspective view showing an example of the workpiece 10. As shown in FIG. [Figure 3] FIG. 3 is a top view showing an example of the workpiece 10. As shown in FIG. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of the control unit 100. As shown in FIG. [Figure 5] FIG. 5 is a flowchart showing an example of a process of a manufacturing method for a device chip. [Figure 6] FIG. 6 is a diagram for explaining the image of the key pattern P acquired in the position coordinate acquisition step S11. [Figure 7] FIG. 7 is a diagram for explaining the planned division line Lc corrected in the second processing step S12. [Figure 8]FIG. 8 is a diagram for explaining the processing in the second processing step S12, and particularly shows an example in which the position coordinate acquisition step S11 and the second processing step S12 are performed in parallel. [Figure 9] FIG. 9 is a diagram for explaining a modified example of the position coordinate obtaining step S11. [Figure 10] FIG. 10 is a diagram for explaining a modified example of the laser irradiation unit 30 and the imaging unit 50. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a device chip manufacturing method and a laser processing apparatus 1 according to one embodiment of the present invention will be described with reference to the drawings.

[0011] First, before describing the details of the device chip manufacturing method, the configuration of the laser processing apparatus 1 used for manufacturing the device chip will be described. In the following description, the X-axis direction is one direction on a horizontal plane. The Y-axis direction is a direction on a horizontal plane that is perpendicular to the X-axis direction. The Z-axis direction is a direction that is perpendicular to the X-axis and Y-axis directions.

[0012] 1 is a perspective view showing an example of a laser processing apparatus 1 according to an embodiment. The laser processing apparatus 1 processes a workpiece 10, which is an object to be processed, by irradiating the workpiece 10 with a laser beam. The processing of the workpiece 10 by the laser processing apparatus 1 is, for example, a modified layer forming process in which a modified layer is formed inside the workpiece 10 by the laser beam. Here, the workpiece 10 will be described.

[0013] (Workpiece) The workpiece 10 is, for example, a substantially disk-shaped wafer or optical device wafer made of a material such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor. The workpiece 10 may also be a variety of plate-shaped processing materials, such as a ceramic, glass, or sapphire-based plate-shaped inorganic material substrate, or a plate-shaped ductile material such as metal or resin. The workpiece 10 may also be a package substrate containing multiple device chips sealed with a molded resin or the like. FIG. 2 shows a wafer as an example of the workpiece 10.

[0014] As shown in FIG. 2, a surface 11 of a workpiece 10 has a plurality of intersecting streets 12 defined as division lines L, forming a grid of regions partitioned by the division lines L. Devices 13, such as integrated circuits (ICs), large-scale integrated circuits (LSIs), and microelectromechanical systems (MEMSs), are formed in each of the regions partitioned by the division lines L. The division lines L include division lines Lx extending in one direction (e.g., the X-axis direction) and division lines Ly extending in another direction (e.g., the Y-axis direction) that intersects the one direction. In the example shown in FIG. 2, the division lines Lx and the division lines Ly are each indicated by a dashed-dotted line. When a wafer, which is the workpiece 10, is divided along the division lines L, individual device chips are formed. In the embodiment, the device chips are, for example, square-shaped, but may also be rectangular.

[0015] In the embodiments, when a planned division line extending in the X-axis direction is indicated, it is marked with the symbol "Lx", when a planned division line extending in the Y-axis direction is indicated, it is marked with the symbol "Ly", and when there is no need to distinguish between a planned division line extending in the X-axis direction and a planned division line extending in the Y-axis direction, it is simply marked with the symbol "L". Furthermore, as will be described later, when a plurality of planned division lines extending in the X-axis direction are to be distinguished from one another, they are marked with the symbols "Lx1", "Lx2", etc., which are numbers added to "Lx".

[0016] Furthermore, the workpiece 10 is transported and processed while being integrated with an annular frame 14 and tape 15 attached so as to cover the opening of the annular frame 14. The frame 14 is an annular plate member formed of, for example, metal or resin, and has an opening larger than the outer diameter of the workpiece 10. The tape 15 is expandable and in the form of a sheet with an outer diameter larger than the opening of the frame 14. The tape 15 is attached to the back side of the frame 14 so as to cover the opening of the frame 14. The workpiece 10 is positioned at a predetermined position in the opening of the frame 14, and the back side of the workpiece 10 is attached to the tape 15, thereby being fixed to the frame 14 and the tape 15.

[0017] 3, a characteristic key pattern P is formed in a predetermined region on the surface 11 of the workpiece 10 (for example, the enlarged portion shown in FIG. 3). This key pattern P is a mark to be detected when aligning the workpiece 10 with the laser processing device 1. The key pattern P utilizes, for example, a characteristic portion of a circuit in a device 13. In the example shown in FIG. 3, the key pattern P is a cross-shaped mark that is parallel to the planned division line Lx and the planned division line Ly and intersects with each other. The key pattern P is located at the same position in each device 13, and if the key patterns P formed on the devices 13 arranged in the same row are connected by a line, the line will be parallel to the planned division lines Lx and Ly in both the X-axis direction and the Y-axis direction.

[0018] 1, the following describes the configuration of the laser processing apparatus 1. The laser processing apparatus 1 includes, as its main components, a holding table 20, a laser irradiation unit 30, a moving unit 40, an imaging unit 50, a display unit 60, and a control unit 100.

[0019] (holding table) The holding table 20 holds the workpiece 10 on a holding surface 21. The holding surface 21 is a disk-shaped surface made of porous ceramic or the like. In this embodiment, the holding surface 21 is a flat surface parallel to the horizontal direction. The holding surface 21 is connected to a vacuum suction source, for example, via a vacuum suction path (not shown). The holding table 20 holds the workpiece 10 placed on the holding surface 21 by suction. A plurality of clamps 22 are arranged around the holding table 20 to clamp the annular frame 14 that supports the workpiece 10.

[0020] The holding table 20 is rotated around an axis parallel to the Z-axis direction by a rotation unit 23. The rotation unit 23 is supported by an X-axis direction moving plate 24, and is moved together with the holding table 20 in the X-axis direction by a movement unit 40 (more specifically, a processing feed unit 41, which will be described later) via the X-axis direction moving plate 24. Furthermore, the rotation unit 23 and the holding table 20 are moved in the Y-axis direction by a movement unit 40 (more specifically, an indexing feed unit 42, which will be described later) via a Y-axis direction moving plate 25.

[0021] (Laser irradiation unit) The laser irradiation unit 30 is a unit that irradiates a laser beam onto the workpiece 10 held on the holding surface 21 of the holding table 20, and is supported by a column 3 that stands upright from the device body 2 of the laser processing device 1. The laser irradiation unit 30 is capable of emitting a pulsed laser beam of a predetermined wavelength that is transparent or absorbent to the workpiece 10 and the tape 15, and in an embodiment in which a modified layer is formed, it emits a transparent laser beam. Specifically, the laser irradiation unit 30 irradiates the laser beam along the planned division line L on the workpiece 10 to form a modified layer 16 (see, for example, FIG. 8 ) inside the workpiece 10.

[0022] The laser irradiation unit 30 also includes a condenser 31 that irradiates the laser beam at a desired position inside the workpiece 10. The condenser 31 is a focusing lens that focuses the laser beam on the workpiece 10 held on the holding table 20 and irradiates the workpiece 10. The focal point of the laser beam focused by the condenser 31 is positioned inside the workpiece 10. In the embodiment, the back side of the workpiece 10 is held on the holding table 20 and the laser beam is irradiated from the front side 11, but it is also possible to hold the front side 11 on the holding table 20 and irradiate the laser beam from the back side.

[0023] The laser irradiation unit 30 then irradiates the laser beam along the planned dividing line L while moving the focal point of the laser beam and the workpiece 10 relative to each other, thereby forming a modified layer 16 along the planned dividing line L.

[0024] (Mobile unit) The moving unit 40 is a unit that moves the focal point of the laser beam in the laser irradiation unit 30 and the imaging unit 50 relative to the workpiece 10 held on the holding table 20. The moving unit 40 includes a processing feed unit 41 and an indexing feed unit 42.

[0025] The processing feed unit 41 is a unit that relatively moves the holding table 20 and the focal point of the laser irradiation unit 30 in the X-axis direction, which is the processing feed direction. The processing feed unit 41 is installed on the device body 2 of the laser processing device 1, supports the X-axis moving plate 24 so that it can move freely in the X-axis direction, and moves the holding table 20 in the X-axis direction via the X-axis moving plate 24, for example.

[0026] The indexing feed unit 42 is a unit that moves the holding table 20 and the focal point of the laser irradiation unit 30 relatively in the Y-axis direction, which is the indexing feed direction. The indexing feed unit 42 is installed on the device body 2 of the laser processing device 1, supports the Y-axis moving plate 25 so that it can move freely in the Y-axis direction, and moves the holding table 20 in the Y-axis direction via, for example, the Y-axis moving plate 25 and the X-axis moving plate 24.

[0027] The processing feed unit 41 and the indexing feed unit 42 each include a ball screw, a pulse motor, and a guide rail (none of which are shown). The ball screw is rotatable about its axis. The pulse motor rotates the ball screw about its axis. The guide rail of the processing feed unit 41 supports the X-axis moving plate 24 so that it can move in the X-axis direction. The guide rail of the processing feed unit 41 is fixed to the Y-axis moving plate 25. The guide rail of the indexing feed unit 42 supports the Y-axis moving plate 25 so that it can move in the Y-axis direction. The guide rail of the indexing feed unit 42 is fixed to the device main body 2.

[0028] (imaging unit) The imaging unit 50 is provided to face the workpiece 10 held on the holding table 20 in the Z-axis direction, and images the workpiece 10. For example, the imaging unit 50 images each planned dividing line L of the wafer, which is the workpiece 10, each street 12, or a key pattern P formed on each device 13. The imaging unit 50 is fixed, for example, adjacent to the condenser 31 of the laser irradiation unit 30, and is moved by the moving unit 40 integrally with the laser irradiation unit 30 relative to the workpiece 10 held on the holding table 20.

[0029] The imaging unit 50 includes a microscope section and an imaging section (not shown), and the imaging section captures the image of the workpiece 10 captured by the microscope section. The imaging element may be, for example, a charge-coupled device (CCD) imaging element or a complementary metal oxide semiconductor (CMOS) imaging element. The imaging unit 50 acquires an image for aligning the workpiece 10 with the laser irradiation unit 30, and outputs the image data to the control unit 100. The imaging unit 50 may be, for example, an infrared ray (IR) camera that uses infrared rays that pass through the workpiece 10. The imaging unit 50 is an example of the "acquisition unit" of the present invention.

[0030] (Display unit) The display unit 60 is a display device equipped with, for example, a touch panel display. The display unit 60 displays various information such as a setting screen for processing conditions and the state of the workpiece 10 captured by the imaging unit 50 (for example, the processing state of the workpiece 10, the streets 12, the key pattern P, and the planned division lines L). The display unit 60 also includes an input unit that can accept various operations such as the operator registering processing information. Furthermore, the display unit 60 may include an alarm unit that emits sound or light to notify the operator of the laser processing apparatus 1 of predetermined information.

[0031] (control unit) The control unit 100 controls each of the above-mentioned components of the laser processing apparatus 1 to cause the laser processing apparatus 1 to perform various processes on the workpiece 10. FIG. 4 shows an example configuration including the control unit 100 and the components that input and output data between the control unit 100 and the outside. The control unit 100 is a computer including a control unit 110 that performs various calculations, a memory unit 120 having a storage medium, and an input / output interface (not shown) that controls the input and output of data between the control unit 100 and the outside. The control unit 110 includes a microprocessor such as a CPU (Central Processing Unit). The memory unit 120 has memories such as an HDD (Hard Disk Drive), ROM (Read Only Memory), or RAM (Random Access Memory). The control unit 110 performs various calculations based on predetermined programs stored in the memory unit 120. The control unit 110 outputs various control signals to the above-mentioned components via the input / output interface according to the calculation results, thereby controlling the laser processing apparatus 1.

[0032] The storage unit 120 stores, for example, key pattern information 120a, which is information about the key pattern P formed on each device 13 described above. The key pattern information 120a stores information such as the shape of the key pattern P (cross-shaped in this embodiment) previously set by an operator or the like, the position coordinates of the key pattern P formed on each device 13, and a reference distance D from the key pattern P to the planned division line L. The position coordinates may be XY coordinates expressed, for example, as "X1, Y1," "X2, Y2," "X3, Y3," etc. The reference distance D is, as shown in FIG. 3, the distance obtained by drawing a perpendicular line from the intersection point of the cross-shaped key pattern P in this embodiment to the planned division line L. Assuming that the key patterns P are formed at the same position on each device 13 before processing by the laser processing apparatus 1, the reference distance D from each key pattern P to the planned division line L will be approximately the same. Note that the key pattern information 120a may also store other information, such as the distance between adjacent planned division lines (not shown).

[0033] The storage unit 120 also stores image data of the workpiece 10 captured by the imaging unit 50. This image data includes, for example, images of the key pattern P, the streets 12, and the planned division lines L. The image data is output from the imaging unit 50 to the control unit 100 and stored in the storage unit 120. The image data captured by the imaging unit 50 and the key pattern information 120a described above can be used as parameters in the processing of the control unit 110, which will be described later. The detailed processing will be described later in the device chip manufacturing method.

[0034] The control unit 110 executes various programs stored in the memory unit 120. As described above, the laser processing apparatus 1 forms modified layers 16 along the streets 12 of the workpiece 10 when manufacturing device chips. Here, the modified layers 16 will be described. The modified layers 16 refer to areas where the density, refractive index, mechanical strength, or other physical properties are different from those of the surrounding area. The modified layers 16 are, for example, crack areas, dielectric breakdown areas, refractive index change areas, or a mixture of these areas. In other words, the areas where the modified layers 16 are formed have lower mechanical strength and other properties than other areas of the workpiece 10.

[0035] If the mechanical strength of the workpiece 10 is reduced in this manner, the workpiece 10 may expand in a direction perpendicular to the direction in which the streets 12 extend, resulting in deformation such as bending of the unprocessed streets 12 (i.e., the streets 12 to be processed). This phenomenon is particularly likely to occur because the number of lines processed on the workpiece 10 has increased with the recent trend toward miniaturization of devices, resulting in denser streets 12. In this state, if a laser beam is irradiated along the remaining planned dividing lines L to be processed, the laser beam will be irradiated linearly onto the devices 13, etc., which may not only damage the product but also prevent the formation of an appropriate modified layer 16 inside the wafer, which is the workpiece 10, potentially resulting in defective division of the workpiece 10. Therefore, in this embodiment, a program is executed to suppress damage to the devices 13 due to the curvature of the streets 12 and defective division of the wafer, which is the workpiece 10.

[0036] The control unit 110 includes, as functional units realized by executing the program, a position coordinate acquisition unit 111 and an irradiation position correction unit 112. Note that, hereinafter, the processes described as being performed by the position coordinate acquisition unit 111 and the irradiation position correction unit 112 are processes realized by the control unit 110.

[0037] The position coordinate acquisition unit 111 acquires the position coordinates of the key pattern P acquired by the imaging unit 50. That is, the position coordinate acquisition unit 111 refers to the storage unit 120 to acquire image data output from the imaging unit 50 to the control unit 100, and acquires the key pattern P of the workpiece 10 included in the captured image from the image data. Note that there may be cases where the storage unit 120 does not store image data but stores the position coordinates of the key pattern P. In such cases, the position coordinate acquisition unit 111 acquires the position coordinates of the key pattern P by referring to the storage unit 120.

[0038] The irradiation position correction unit 112 corrects the predetermined division line L based on the position coordinates of the key pattern P acquired by the position coordinate acquisition unit 111, and irradiates the laser beam along the corrected division line Lc. The specific processing content will be described in the device chip manufacturing method.

[0039] (Device Chip Manufacturing Method) Next, a method for manufacturing a device chip in an embodiment will be described. FIG. 5 is a flowchart showing an example of the method for manufacturing the device chip. The manufacturing method includes a first processing step S10, a position coordinate acquisition step S11, and a second processing step S12. The second processing step S12 includes an irradiation position correction step S13. The processing of each of these steps is executed by the control unit 110. Note that the position coordinate acquisition step S11 and the second processing step S12 may be executed in parallel, and in the embodiment, an example in which the position coordinate acquisition step S11 and the second processing step S12 are executed in parallel will be described. An example in which the position coordinate acquisition step S11 and the second processing step S12 are executed separately (i.e., sequentially) will be described later in a modified example.

[0040] In the device chip manufacturing method of the embodiment, before executing the first processing step S10, the control unit 110 transports the workpiece 10 onto the holding table 20 using a transport unit or the like not shown, and holds the workpiece 10 on the holding surface 21 of the holding table 20.

[0041] In the first processing step S10, the control unit 110 forms a modified layer 16 inside the workpiece 10 by irradiating a laser beam having a wavelength that transmits through the workpiece 10 along the first planned dividing line. Here, the first planned dividing line may be either a planned dividing line Lx extending in the X-axis direction or a planned dividing line Ly extending in the Y-axis direction, but in this embodiment, it is the planned dividing line Lx extending in the X-axis direction.

[0042] The first processing step S10 will be described in detail. The control unit 110 captures an image of any one of the multiple streets 12 formed in the X-axis direction, and uses the captured image to rotate the holding table in the X-axis direction, for example, so that the street 12 on the workpiece 10 is parallel to the movement direction of the laser irradiation unit 30 and the imaging unit 50. Then, since a planned division line Lx is formed in advance along the center of the street 12 and extending in the X-axis direction, the control unit 110 controls the laser irradiation unit 30 to irradiate a laser beam along the planned division line Lx, thereby performing a processing process to form a modified layer 16 inside the workpiece 10. The processing is performed sequentially, starting from the planned division line Lx1 formed on the outside of the workpiece 10, as shown in FIG. 3, for example.

[0043] Furthermore, in the first processing step S10, the processing to form the modified layer 16 may be performed on any number of planned division lines Lx (e.g., 1, 3, 5, 10, etc.) set by an operator or the like from among the multiple planned division lines Lx extending in the X-axis direction. This arbitrary number is determined, for example, taking into consideration deformation (curvature) of the streets 12 resulting from the formation of the modified layer 16. That is, the number of lines to be processed is determined taking into consideration circumstances such as the need to correct the processing line to be irradiated with the laser beam because continuing processing along the predetermined planned division lines Lx may damage the device 13 or the like. The arbitrary number of lines to be processed in this first processing step S10 may be determined in advance, for example, through experiments to obtain the degree of deformation of the streets 12 due to the formation of the modified layer 16. Furthermore, the degree of deformation of the streets 12 may vary depending on the material of the workpiece 10, and therefore the arbitrary number to be processed in this first processing step S10 may be determined depending on the material of the workpiece 10, for example. In the embodiment, in the first processing step S10, processing is performed along three planned division lines Lx1, Lx2, and Lx3, for example.

[0044] In the position coordinate acquisition step S11, the control unit 110 acquires the position coordinates of the key pattern P formed in a predetermined area of ​​the workpiece 10 along the extension direction of an adjacent planned division line adjacent to the planned division line Lx processed in the first processing step S10. The adjacent planned division line means a planned division line Lx that has not yet been processed and is to be processed, among the planned division lines adjacent to the planned division line Lx processed in the first processing step S10 (here, the planned division lines Lx1, Lx2, and Lx3). For example, the adjacent planned division line is the planned division line L4 adjacent to the planned division line Lx3.

[0045] More specifically, in the position coordinate acquisition step S11, the control unit 110 controls the imaging unit 50 to capture an image of an area not irradiated with the laser beam. For example, an image of the key pattern P formed on the device 13 of the workpiece 10 in the extension direction of the planned division line Lx to be processed next (i.e., the X-axis direction) is captured. That is, the control unit 110 moves the holding table 20 in the X-axis direction using the moving unit 40, and captures an image of the key pattern P on the planned division line Lx to be processed next using the imaging unit 50. The captured image is output to the control unit 100, and the control unit 110 acquires the position coordinates of the key pattern P from the image.

[0046] FIG. 6 is a diagram showing an example of an image of the acquired key pattern P. The image in FIG. 6 shows a portion of the entire workpiece 10, and for convenience of explanation, shows a portion of the key pattern P formed on the device 13 in the extension direction of one planned division line Lx4 and already-processed lines Lp. The already-processed lines Lp here are lines processed by the laser irradiation unit 30 along the planned division lines Lx1, Lx2, and Lx3. Note that since the modified layer 16 formed by the processed lines Lp is formed inside the workpiece 10, it is usually impossible to determine whether or not the line has been processed unless cracks or the like have occurred. However, in the example shown in FIG. 6, the processed lines Lp are drawn with solid lines for convenience of explanation that the lines have been processed.

[0047] Furthermore, in the position coordinate acquisition step S11, the control unit 110 acquires position coordinates of a plurality of key patterns P at predetermined intervals along the planned division line Lx to be processed next. This process is for acquiring a "corrected planned division line Lc," which is a line obtained by correcting the predetermined planned division line Lx, to be acquired in the second processing step S12 described below. Therefore, in terms of acquiring the corrected planned division line Lc, at least two key patterns P are sufficient, but in order to acquire a line with high accuracy, it is better to have a larger number of key patterns P. In this embodiment, since it is assumed that the street 12 is curved, it is preferable to acquire position coordinates of three or more key patterns P so that a corrected planned division line Lc that follows the curve of the street 12 can be acquired.

[0048] As can be seen from Fig. 6, the position of the key pattern P is different on each device 13. In other words, there is variation in the distance from the division line Lx4 to the center of each key pattern P, and part of the division line Lx4 overlaps with the device 13. Therefore, if processing continues along such a division line Lx4, there is a risk of damaging the device 13. Therefore, in the second processing step S12, the division line Lx to be processed is corrected before processing is performed.

[0049] In the second processing step S12, the control unit 110 corrects the planned division line Lx to be processed (i.e., the planned division line Lx4, which is an example of the adjacent planned division line mentioned above) based on the position coordinates of the key pattern P acquired in the position coordinate acquisition step S11, and irradiates a laser beam along the corrected planned division line Lc to form a modified layer 16 inside the workpiece 10.

[0050] The second processing step S12 includes an irradiation position correction step S13. The second processing step S12 performs a process of calculating a "corrected planned division line Lc," which is a line obtained by correcting the planned division line Lx, in the irradiation position correction step S13, and then performs a process of forming a modified layer 16.

[0051] Specifically, in irradiation position correction step S13, control unit 110 acquires the amount of positional deviation between the position coordinates of the multiple key patterns P acquired in position coordinate acquisition step S11 and the position coordinates of the unprocessed key pattern P stored in storage unit 120. That is, control unit 110 refers to storage unit 120 to identify the position coordinates of the key pattern P corresponding to each of the position coordinates of the multiple acquired key patterns P, and acquires the amount of positional deviation in the Y-axis direction by comparing them with the position coordinates of the key pattern P formed on each device 13.

[0052] The control unit 110 then offsets the planned division line Lx to be processed by the acquired amount of positional deviation, thereby calculating the locus of the corrected planned division line Lc. Fig. 7 is a diagram for explaining an example of the corrected planned division line Lc. As can be seen from Fig. 7, the corrected planned division line Lc has a curved shape. In other words, by correcting the predetermined planned division line Lx4 based on the position coordinates of the key pattern P that has been misaligned in the Y-axis direction, the corrected planned division line Lc becomes a line that follows the shape of the curved street 12.

[0053] Note that the means for calculating the trajectory of this corrected (i.e., post-correction) planned division line Lc is not limited to this, as long as it can be calculated using the position coordinates of the key pattern P. For example, the storage unit 120 stores in advance a reference distance D from the key pattern P to the planned division line Lx. Therefore, for example, the control unit 110 may find each point where the distance from the center of the acquired key pattern P (the point where the cross-shaped key pattern P intersects) to a predetermined planned division line Lx is the reference distance D, and the line connecting each point may be set as the trajectory of the corrected planned division line Lc. As a result, the trajectory will follow the curved street 12.

[0054] In the second processing step S12, a modified layer 16 is formed inside the workpiece 10 along the "corrected planned dividing line Lc" calculated in this way.

[0055] 8 is a diagram for explaining the processing in the second processing step S12. In the example shown in FIG. 8, the position coordinate acquisition step S11 described above is executed in parallel with the second processing step S12. That is, the example shows the case where the moving unit 40 moves the holding table 20 in the X-axis direction, the laser irradiation unit 30 forms a modified layer 16 inside the workpiece 10, and the imaging unit 50 acquires the key pattern P formed on the device 13. Note that in the example shown in FIG. 8, the imaging unit 50 is disposed on the forward side (front side) of the laser irradiation unit 30 in the X-axis direction, which advances the processing. However, the imaging unit 50 may be disposed, for example, behind the laser irradiation unit 30. Alternatively, the imaging unit 50 may be disposed before or after the laser irradiation unit 30.

[0056] In this way, by executing the position coordinate acquisition step S11 while executing the second processing step S12, it is possible, for example, to irradiate a laser beam onto the planned division line Lx currently being processed, and to correct the planned division line Lx in real time and form a modified layer 16 along the corrected planned division line Lc.

[0057] In the second processing step S12, in addition to irradiating the laser beam onto the planned division line Lx currently being processed (for example, the planned division line Lx4) based on the position coordinates of the acquired key pattern P, for example, after processing the planned division line Lx4 currently being processed, the laser beam may be irradiated onto an adjacent planned division line Lx that has not been irradiated with the laser beam (for example, the planned division line Lx5 shown in FIG. 3) based on the position coordinates of the acquired key pattern P. In other words, the acquisition of the position coordinates of the key pattern P is carried out in parallel with the second processing step S12, but processing based on the position coordinates of the acquired key pattern P may be carried out on a planned division line Lx different from the planned division line Lx currently being processed. The planned division line Lx4 is an example of a "second planned division line" in the present invention, and the planned division line Lx5 is an example of a "third planned division line" in the present invention.

[0058] 5 at predetermined intervals (of the planned division lines Lx) taking into consideration deformation of the streets 12. Then, when the control unit 110 has completed the processing for all the planned division lines Lx in the X-axis direction, it then performs the same processing for the planned division lines Ly in the Y-axis direction that intersect with the planned division lines Lx in the X-axis direction. For example, the processing is performed in the order of the planned division lines Ly1, Ly2, and Ly3 shown in FIG. 3.

[0059] At this time, as described above, the position coordinate acquisition step S11 acquires the position coordinates of multiple key patterns P at predetermined intervals along the planned division line Ly to be processed next, but these intervals may be different from the intervals acquired during processing in the X-axis direction. This is because the degree of deformation of the street 12 may differ in the X-axis direction and the Y-axis direction, and it is preferable to acquire the position coordinates of the key pattern P at intervals according to each condition. In other words, when acquiring the position coordinates of the key pattern P along the planned division line Ly in the position coordinate acquisition step S11, the control unit 110 may acquire the position coordinates of the key pattern P at intervals different from the intervals of the position coordinates of the key pattern P acquired along the planned division line Lx extending in the X-axis direction.

[0060] The planned division line Lx is an example of a "planned first direction division line extending in a first direction" of the present invention, and the planned division line Ly is an example of a "planned second direction division line extending in a second direction". Furthermore, the interval between the position coordinates of the key pattern P obtained along the planned division line Lx is an example of a "first interval", and the interval between the position coordinates of the key pattern P obtained along the planned division line Ly is an example of a "second interval".

[0061] On the other hand, when processing the planned division line Ly after processing the planned division line Lx, the interval (i.e., second interval) of the position coordinates along the planned division line Ly may have widened due to the processing process that has already been performed to form the modified layer 16 in the X-axis direction. Specifically, since the modified layer 16 has already been formed in the X-axis direction, the distance between the key patterns may have widened compared to before the processing process was performed. Therefore, it is preferable to acquire the position coordinates of the key pattern P along the planned division line Ly taking such circumstances into consideration. For example, when forming the modified layer 16 along the planned division line Ly after forming the modified layer 16 along the planned division line Lx, the control unit 110 sets the interval of the position coordinates of the key pattern P acquired along the planned division line Ly to a "third interval" that is larger than the second interval. In other words, the control unit 110 acquires the position coordinates of the key pattern P along the planned division line Ly taking into account the widening of the distance between the key patterns. This results in the position coordinates of the key pattern P being based on the desired interval.

[0062] The processing of the other planned division lines Ly extending in the Y-axis direction is similar to the processing of the planned division lines Lx extending in the X-axis direction, and therefore a description thereof will be omitted.

[0063] Then, the workpiece 10 on which the modified layer 16 has been formed in this way is divided starting from the modified layer 16 by applying an external force in the radial direction to the tape 15, for example, by a dedicated device (not shown). As a result, the multiple devices 13 formed on the workpiece 10 are divided into individual pieces, and multiple device chips are manufactured.

[0064] As described above, in the embodiment, the predetermined dividing line L is corrected based on the position coordinates of the key pattern P, and the irradiation position of the laser beam on the workpiece 10 is adjusted along the corrected dividing line Lc. As a result, even if deformation such as curvature of the street 12 occurs, for example, in the process of forming the modified layer 16 inside the workpiece 10, the dividing line L is corrected based on the position coordinates of the key pattern P, and the laser beam is irradiated along the corrected dividing line Lc. As a result, it is possible to irradiate the laser beam in a manner that follows the curved street 12, and it is possible to prevent the laser beam from being irradiated linearly onto the device 13, thereby suppressing or avoiding damage to the device 13 and leaving the workpiece 10, i.e., a wafer, undivided.

[0065] Furthermore, as described above, in the embodiment, for example, after the first processing step S10 is performed, the position coordinate acquisition step S11 is performed while the second processing step S12 is being performed, and a laser beam is irradiated onto the planned division line being processed based on the position coordinates of the key pattern P acquired in the position coordinate acquisition step S11. This makes it possible to perform the second processing step S12 by following the key pattern P acquired in the position coordinate acquisition step S11, making it possible to correct the planned division line L in real time, and also to irradiate the laser beam along the corrected planned division line Lc in the second processing step S12.

[0066] Furthermore, in an embodiment, for example, after the first processing step S10 is performed, the position coordinate acquisition step S11 is performed while the second processing step S12 is being performed, and a laser beam is irradiated onto an adjacent planned division line different from the planned division line L currently being processed based on the position coordinates of the key pattern P acquired in the position coordinate acquisition step S11. This reduces the control load compared to, for example, the above-mentioned case where the planned division line L is processed while being corrected in real time, and there is a possibility that the accuracy of correction of the planned division line L and processing can be improved.

[0067] Furthermore, in the embodiment, in the position coordinate acquisition step S11, a plurality of position coordinates of the key pattern P are acquired along the planned division line L to be processed. Therefore, it is possible to calculate the trajectory of the planned division line Lc to be corrected based on the acquired position coordinates of the plurality of key patterns P. In particular, the more position coordinates of the key patterns P that are acquired, the more accurate the trajectory can be calculated, and therefore the accuracy of correction of the planned division line can be improved.

[0068] Furthermore, in the embodiment, for example, the intervals for acquiring the position coordinates of the key pattern P for the planned division line Lx extending in the X-axis direction and the planned division line Ly extending in the Y-axis direction are different. That is, the conditions for acquiring the position coordinates of the key pattern P are independent of each other. In other words, since deformation such as curvature of the street 12 may differ between the X-axis direction and the Y-axis direction, it is possible to more accurately process the street 12 in accordance with the shape by acquiring the position coordinates of the key pattern P in each axial direction, correcting the planned division line based on this, and irradiating the laser.

[0069] On the other hand, for example, when processing the planned division line Ly after processing the planned division line Lx, the interval between the position coordinates along the predetermined division line Ly may have widened due to the processing process that has already been performed to form the modified layer 16 in the X-axis direction. However, the above-described embodiment is configured to take such a circumstance into consideration. That is, the interval between the position coordinates of the key pattern P acquired along the planned division line Ly is set to a third interval that is larger than the predetermined second interval. As a result, even if the device interval has widened due to processing along the planned division line Lx, for example, by acquiring the position coordinates of the key pattern P along the planned division line Ly at the third interval that is larger than the predetermined second interval, processing on the planned division line Ly is based on the position coordinates of the key pattern P at the desired device interval.

[0070] (Variation) Next, a modified example will be described. In the above embodiment, the processing of the position coordinate acquisition step S11 is configured to be performed in parallel with the processing of the second processing step S12, but the processing of the position coordinate acquisition step S11 may be performed separately from the processing of the second processing step S12. In this case, after the first processing step S10 is performed, the processing of the position coordinate acquisition step S11 and the second processing step S12 are performed in this order.

[0071] FIG. 9 is a diagram showing an example of a modified example of the processing of the position coordinate acquisition step S11. In the example shown in FIG. 9, the second processing step S12 is not performed in parallel, so only the imaging unit 50 is moved relative to the holding table 20.

[0072] In this way, by performing the processing of the position coordinate acquisition step S11 as a separate process rather than in parallel with the second processing step S12, the accuracy of both processes may be improved compared to, for example, performing the process of acquiring the key pattern P and the process of irradiating the workpiece 10 with a laser beam simultaneously, and in that case, processing can be performed more accurately in line with the deformation of the street 12.

[0073] Furthermore, in the above-described embodiment, the laser irradiation unit 30 is disposed so as to face the processing target on the workpiece 10 in the Z-axis direction, and the imaging unit 50 is disposed adjacent to the laser irradiation unit 30. Therefore, the laser irradiation unit 30 and the imaging unit 50 are disposed on different axes. On the other hand, the target irradiated with the laser beam by the laser irradiation unit 30 and the target imaged by the imaging unit 50 are substantially the same, such as the planned division line L and the street 12, so it is preferable that the processing position in the laser irradiation unit 30 and the imaging position in the imaging unit 50 are coaxial. Therefore, FIG. 10 schematically shows an example of a configuration in which the processing position in the laser irradiation unit 30 and the imaging position in the imaging unit 50 are substantially coaxial.

[0074] In the modification shown in FIG. 10, of the components constituting the laser processing apparatus 1 described above, the laser irradiation unit 30, the imaging unit 50, and the workpiece 10 are shown.

[0075] 10, the laser irradiation unit 30 includes a laser oscillator 32 that emits a laser beam, a dichroic mirror 33, and a condenser 31. The imaging unit 50 includes a camera 51, a light source 52, and a dichroic mirror 53.

[0076] In the laser irradiation unit 30, a laser beam emitted from a laser oscillator 32 is transmitted through a dichroic mirror 33 and directed to a condenser 31, and a modified layer 16 is formed inside the workpiece 10. In the imaging unit 50, illumination light emitted from a light source 52 is reflected by the dichroic mirror 33 and directed to an imaging area via the condenser 31, and incident light from the imaging area is directed to a camera 51 via the condenser 31. The camera 51 can image the imaging area based on the incident light from the imaging area. The imaging area refers to the planned dividing line L, the street 12, etc. on the workpiece 10.

[0077] 10, it is possible to coaxially irradiate the laser beam in the laser irradiation unit 30 and the illumination light for imaging in the imaging unit 50. This prevents deviation from occurring between the processing position of the workpiece 10 in the laser irradiation unit 30 and the imaging position in the imaging unit 50, making it possible to more accurately correct the planned division line Lc and to perform processing along the corrected planned division line Lc.

[0078] It should be noted that the modified example shown in FIG. 10 is not limited to the example of FIG. 10, as long as the laser beam of the laser irradiation unit 30 and the illumination light in the imaging unit 50 are configured coaxially.

[0079] Although the embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0080] In the above embodiment, machining is performed from the division line Lx extending in the X-axis direction among the mutually intersecting division lines L, but machining may also be performed from the division line Ly extending in the Y-axis direction.

[0081] In the above-described embodiment, the focal point of the laser beam is moved relative to the workpiece 10 by moving the holding table 20 using the moving unit 40. However, for example, the focal point of the laser beam may be moved relative to the workpiece 10 by scanning the laser irradiation unit 30. In other words, the relative movement may be achieved by scanning the laser beam. When scanning the laser beam, for example, a known galvanometer scanner, an acousto-optic deflector (AOD), an optical modulator, or the like may be used.

[0082] Furthermore, for example, the above-described laser processing apparatus 1 may exist as a plurality of separate devices. For example, at least some of the imaging unit 50, display unit 60, control unit 110, and storage unit 120 included in the above-described laser processing apparatus 1 may be separate devices. Furthermore, a processing system may be configured by a plurality of devices. For example, if the imaging unit 50 is configured independently from the laser processing apparatus 1, image data captured by the imaging unit 50 is output to the control unit 100 and stored in the storage unit 120, and the control unit 110 refers to the storage unit 120 to obtain the position coordinates of the key pattern P formed on the device 13. Note that the devices and systems existing as a plurality of separate devices are not limited to this.

[0083] Furthermore, for example, in the above-described control unit 100, the position coordinate acquisition unit 111 and the irradiation position correction unit 112, which constitute the control unit 110, may be separated into multiple devices. For example, some of the functions of the position coordinate acquisition unit 111 and the irradiation position correction unit 112 may be realized by a server or the like.

[0084] The manufacturing method described in the above-described embodiment can be realized by executing a prepared control program on a computer. The control program is recorded on a computer-readable storage medium and executed by being read from the storage medium. The control program may be provided in a form stored on a non-transitory storage medium such as a flash memory, or may be provided via a network such as the Internet. The computer that executes the control program may be included in a processing device, or may be included in an electronic device such as a smartphone, tablet, or personal computer that can communicate with the processing device, or may be included in a server device that can communicate with these processing devices and electronic devices.

[0085] This specification describes at least the following items. Note that the components in parentheses correspond to those in the above-described embodiment, but are not limited to these.

[0086] (1) A method for manufacturing device chips, in which a workpiece (workpiece 10) having a plurality of devices (devices 13) formed in an area partitioned by a plurality of planned dividing lines (planned dividing lines L) is divided along the planned dividing lines to manufacture device chips, A first processing step (first processing step S10) of forming a modified layer (modified layer 16) inside the workpiece by irradiating a laser beam having a wavelength that transmits the workpiece along a first planned dividing line (planned dividing line Lx3); After the first processing step is performed, a second processing step (second processing step S12) is performed in which the laser beam is irradiated along an adjacent dividing line (dividing line Lx4) adjacent to the first dividing line processed in the first processing step to form a modified layer inside the workpiece; a position coordinate acquiring step (position coordinate acquiring step S11) of acquiring position coordinates of a key pattern (key pattern P) formed in a predetermined area of ​​the workpiece along an extension direction of the adjacent planned dividing line after the first processing step is performed, The second processing step includes: correcting the adjacent planned division line based on the position coordinates of the key pattern acquired in the position coordinate acquisition step, and irradiating the laser beam along the corrected adjacent planned division line (corrected planned division line Lc); A method for manufacturing a device chip.

[0087] According to (1), for example, it is possible to irradiate the laser beam in a manner that follows a curved or otherwise deformed street, and it is possible to prevent the laser beam from being irradiated in a straight line onto the device, thereby suppressing or avoiding damage to the device and leaving the workpiece undivided.

[0088] (2) A method for manufacturing the device chip according to (1), the position coordinate acquiring step acquires position coordinates of the key pattern by capturing an image of an area not irradiated with the laser beam while the second processing step is being performed; the second processing step irradiates the laser beam onto the adjacent planned division line being processed based on the acquired position coordinates of the key pattern; A method for manufacturing a device chip.

[0089] According to (2), for example, the second processing step can be executed by following the key pattern acquired in the position coordinate acquisition step, and the planned division line can be corrected in real time, and in the second processing step, a laser beam can be irradiated along the corrected planned division line.

[0090] (3) A method for manufacturing the device chip according to (1), The adjacent planned dividing lines include at least a second planned dividing line (planned dividing line Lx4) and a third planned dividing line (planned dividing line Lx5), the position coordinate acquiring step acquires position coordinates of the key pattern by capturing an image of an area not irradiated with the laser beam while processing the second planned division line in the second processing step; the second processing step includes irradiating the laser beam onto the third planned dividing line based on the acquired position coordinates of the key pattern after processing along the second planned dividing line; A method for manufacturing a device chip.

[0091] According to (3), for example, compared to the case where the planned dividing lines are corrected in real time while processing is performed as described above, the control load can be reduced, and the accuracy of the correction of the planned dividing lines and the processing that accompanies it can be improved.

[0092] (4) A method for manufacturing the device chip according to (1), the position coordinate acquisition step is performed after the first processing step is performed and before the second processing step is performed; A method for manufacturing a device chip.

[0093] According to (4), the position coordinate acquisition step and the second processing step are each performed as separate processes, so the accuracy of each process can be improved compared to, for example, when the position coordinate acquisition step and the second processing step are performed in parallel, and in that case, processing can be performed more accurately in line with street deformation.

[0094] (5) A method for manufacturing the device chip according to (1), the position coordinate obtaining step obtains position coordinates of the plurality of key patterns at predetermined first intervals along the adjacent division planned line; A method for manufacturing a device chip.

[0095] According to (5), for example, it is possible to calculate the locus of the planned dividing line to be corrected based on the position coordinates of the acquired multiple key patterns.

[0096] (6) A method for manufacturing the device chip according to (5), The adjacent planned division lines include a first direction planned division line (planned division line Lx) extending in a first direction and a second direction planned division line (planned division line Ly) extending in a second direction intersecting the first direction, The position coordinate acquisition step includes: When acquiring position coordinates of the key pattern along the first direction planned division line, acquiring position coordinates of the key pattern at each of the first intervals; When acquiring the position coordinates of the key pattern along the second direction planned division line, the position coordinates of the key pattern are acquired at second intervals different from the first intervals. A method for manufacturing a device chip.

[0097] According to (6), the intervals for acquiring the position coordinates of the key patterns of the first direction dividing line extending in the first direction and the second direction dividing line extending in the second direction are different from each other. This makes it possible to acquire the position coordinates of the key patterns at intervals that take into account the deformation of the workpiece in each direction, and as a result, it becomes possible to correct the dividing line more accurately.

[0098] (7) A method for manufacturing the device chip according to (5), the adjacent planned dividing lines include a first direction planned dividing line extending in a first direction and a second direction planned dividing line extending in a second direction intersecting the first direction, In the case where the modified layer is formed along the first direction dividing line and then the modified layer is formed along the second direction dividing line, The position coordinate acquisition step includes: When acquiring position coordinates of the key pattern along the first direction planned division line, acquiring position coordinates of the key pattern at each of the first intervals; When acquiring the position coordinates of the key patterns along the second direction planned division line, the position coordinates of the key patterns are acquired at third intervals that are greater than the predetermined second intervals. A method for manufacturing a device chip.

[0099] According to (7), even if the device spacing becomes wider due to processing along the planned division line in the first direction, by obtaining the position coordinates of the key pattern along the planned division line in the second direction at every third interval that is greater than the predetermined second interval, the processing along the planned division line in the second direction will be based on the position coordinates of the key pattern at the desired device spacing.

[0100] (8) A laser processing device (laser processing device 1) that processes a workpiece (workpiece 10) on which a plurality of devices (devices 13) are formed in an area partitioned by a plurality of planned division lines (planned division lines L) by irradiating the workpiece with a laser beam, A holding table (holding table 20) for holding the workpiece; a laser irradiation unit (laser irradiation unit 30) that irradiates the workpiece with the laser beam having a wavelength that is transparent to the workpiece to form a modified layer (modified layer 16) inside the workpiece; a moving unit (moving unit 40) that moves the workpiece held on the holding table and the focal point of the laser beam relatively; an acquisition unit (imaging unit 50) for acquiring position coordinates of a key pattern (key pattern P) formed in a predetermined area of ​​the workpiece; a control unit (control unit 100) that controls the laser processing device; The control unit a position coordinate acquisition unit (position coordinate acquisition unit 111) for acquiring the position coordinates of the key pattern acquired by the acquisition unit; an irradiation position correction unit (irradiation position correction unit 112) that corrects the planned division line based on the acquired position coordinates and irradiates the laser beam along the corrected planned division line (corrected planned division line Lc), Laser processing equipment.

[0101] According to (8), for example, it is possible to irradiate the laser beam in a manner that follows a curved or otherwise deformed street, and it is possible to prevent the laser beam from being irradiated in a straight line onto the device, thereby suppressing or avoiding damage to the device and leaving the workpiece undivided. [Explanation of symbols]

[0102] 1. Laser processing equipment 10 Workpiece 13 devices 16 Modified layer 20 Holding table 30 Laser irradiation unit 40 Mobile Units 50 Imaging unit (acquisition unit) 100 control unit 111 Position coordinate acquisition unit 112 Irradiation position correction section L planned division line Lc corrected division line Lx planned division line (first direction planned division line) Ly planned division line (planned division line in the second direction) Lx3 division line (first division line) Lx4 division line (adjacent division line, second division line) Lx5 division line (third division line) P key pattern S10 First processing step S11 Position coordinate acquisition step S12 Second processing step

Claims

1. A method of manufacturing device chips, comprising: dividing a workpiece, on which a plurality of devices are formed in an area partitioned by a plurality of planned dividing lines, along the planned dividing lines to manufacture device chips, a first processing step of forming a modified layer inside the workpiece by irradiating the workpiece with a laser beam having a wavelength that can transmit along a first planned dividing line; a second processing step in which, after the first processing step is performed, the laser beam is irradiated along an adjacent dividing line adjacent to the first dividing line processed in the first processing step to form a modified layer inside the workpiece; a position coordinate acquiring step of acquiring position coordinates of a key pattern formed in a predetermined area of ​​the workpiece along an extending direction of the adjacent planned dividing line after the first processing step is performed, The second processing step includes: correcting the adjacent planned division line based on the position coordinates of the key pattern acquired in the position coordinate acquisition step, and irradiating the laser beam along the corrected adjacent planned division line; A method for manufacturing a device chip.

2. 2. A method for manufacturing a device chip according to claim 1, comprising: the position coordinate acquiring step acquires position coordinates of the key pattern by capturing an image of an area not irradiated with the laser beam while the second processing step is being performed; the second processing step irradiates the laser beam onto the adjacent planned division line being processed based on the acquired position coordinates of the key pattern; A method for manufacturing a device chip.

3. 2. A method for manufacturing a device chip according to claim 1, comprising: the adjacent planned dividing lines include at least a second planned dividing line and a third planned dividing line, the position coordinate acquiring step acquires position coordinates of the key pattern by capturing an image of an area not irradiated with the laser beam while processing the second planned division line in the second processing step; the second processing step includes irradiating the laser beam onto the third planned dividing line based on the acquired position coordinates of the key pattern after processing along the second planned dividing line; A method for manufacturing a device chip.

4. 2. A method for manufacturing a device chip according to claim 1, comprising: the position coordinate acquisition step is performed after the first processing step is performed and before the second processing step is performed; A method for manufacturing a device chip.

5. 2. A method for manufacturing a device chip according to claim 1, comprising: the position coordinate obtaining step obtains position coordinates of the plurality of key patterns at predetermined first intervals along the adjacent division planned line; A method for manufacturing a device chip.

6. 6. A method for manufacturing a device chip according to claim 5, the adjacent planned dividing lines include a first direction planned dividing line extending in a first direction and a second direction planned dividing line extending in a second direction intersecting the first direction, The position coordinate acquisition step includes: When acquiring position coordinates of the key pattern along the first direction planned division line, acquiring position coordinates of the key pattern at each of the first intervals; When acquiring the position coordinates of the key pattern along the second direction planned division line, the position coordinates of the key pattern are acquired at second intervals different from the first intervals. A method for manufacturing a device chip.

7. 6. A method for manufacturing a device chip according to claim 5, the adjacent planned dividing lines include a first direction planned dividing line extending in a first direction and a second direction planned dividing line extending in a second direction intersecting the first direction, In the case where the modified layer is formed along the first direction dividing line and then the modified layer is formed along the second direction dividing line, The position coordinate acquisition step includes: When acquiring position coordinates of the key pattern along the first direction planned division line, acquiring position coordinates of the key pattern at each of the first intervals; When acquiring the position coordinates of the key pattern along the second direction planned division line, the position coordinates of the key pattern are acquired at third intervals that are greater than the predetermined second intervals. A method for manufacturing a device chip.

8. A laser processing apparatus for processing a workpiece by irradiating a laser beam onto the workpiece, the workpiece having a plurality of devices formed in areas partitioned by a plurality of planned division lines, a holding table for holding the workpiece; a laser irradiation unit that irradiates the workpiece with the laser beam having a wavelength that is transparent to the workpiece to form a modified layer inside the workpiece; a moving unit that moves the workpiece held on the holding table and the focal point of the laser beam relatively; an acquisition unit for acquiring position coordinates of a key pattern formed in a predetermined area of ​​the workpiece; a control unit for controlling the laser processing device, The control unit a position coordinate acquisition unit for acquiring position coordinates of the key pattern acquired by the acquisition unit; an irradiation position correction unit that corrects the planned division line based on the acquired position coordinates and irradiates the laser beam along the corrected planned division line, Laser processing equipment.

Images