Substrate processing method

Abstract

To improve accuracy in measuring a top face height in a substrate.SOLUTION: A substrate processing method is provided for processing a substrate along a plurality of predetermined dividing lines by means of a processing unit, and includes: a setting step 1001 of setting a position where a top face height of the substrate is measured with coordinates defining a center of the substrate as a reference; a holding step 1002 of holding the substrate on a holding table; a center detection step 1003 of detecting the center of the substrate held on the holding step; a measuring step 1004 of measuring the top face height of the substrate at the position set in the setting step 1001 with the center of the substrate detected in the center detection step 1003 defined as the reference; and a processing step 1005 of processing the substrate along the predetermined dividing lines by operating the processing unit in accordance with the measured top face height after the measuring step 1004 is implemented.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for processing a substrate. [Background technology]

[0002] In a substrate processing method for forming a processed groove or a modified layer in a substrate, the height of the upper surface of the substrate is measured and the processing height is determined based on the upper surface height. For example, Patent Document 1 discloses a processing method in which the position of the surface of a workpiece held on a chuck table is measured before cutting the workpiece, and a processed groove is formed based on that position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-298003 Summary of the Invention [Problem to be solved by the invention]

[0004] With conventional processing methods, if bumps or uneven patterns are formed on the measurement surface of a substrate, the top surface height will change depending on the measurement position, and it may not be possible to form processed grooves or modified layers in the desired positions.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a substrate processing method that can improve the measurement accuracy of the upper surface height of a substrate. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a substrate processing method of the present invention is a substrate processing method in which a substrate is processed along a plurality of planned dividing lines by a processing unit, and a position for measuring the height of an upper surface of the substrate is , set at a position where a flat area can be secured on the upper surface of the substrate on which the pattern is formed, andThe method is characterized by comprising a setting step of setting coordinates based on the center of the substrate; a holding step of holding the substrate on a holding table; a center detection step of detecting the center of the substrate held on the holding table; a measurement step of measuring the height of the top surface of the substrate at the position set in the setting step based on the center of the substrate detected in the center detection step; and a processing step of operating the processing unit according to the measured top surface height after the measurement step is performed, and processing along the planned division line. In the substrate processing method, the setting step may set the position for measuring the height of the upper surface of the substrate at a location where a flat area can be secured on the upper surface of the substrate on which the pattern is formed, and may set the position using coordinates excluding the center of the substrate as the reference. In the substrate processing method, the setting step may set the position for measuring the height of the top surface of the substrate at a location where a flat area can be secured in the peripheral excess area of ​​the top surface of the substrate on which the pattern is formed, and may set the position using coordinates based on the center of the substrate.

[0007] In the substrate processing method, the processing unit is a cutting unit that cuts the substrate by moving a cutting blade relative to the substrate, and the height at which the cutting blade cuts may be adjusted according to the height measured in the measurement step to form a cutting groove in the substrate.

[0008] In the substrate processing method, the processing unit may be a laser beam application unit that applies a laser beam to the substrate, and the height at which the laser beam is focused may be adjusted according to the height measured in the measurement step, thereby forming a processed groove or a modified layer in the substrate. In the substrate processing method, if the upper surface height is measured at a plurality of locations in the measuring step, the processing step may involve setting an average value of the measured values ​​as the upper surface height and then cutting. In the substrate processing method, the processing step may include forming a top surface height map that calculates the gradient of the top surface height of the entire substrate based on the top surface heights at multiple locations, and processing the substrate according to the top surface height map. In the substrate processing method, the measuring step may measure the height of the upper surface of the substrate by positioning a back pressure sensor at a position set in the setting step with reference to the center of the substrate detected in the center detecting step. [Effects of the Invention]

[0009] The substrate processing method of the present invention has the effect of improving the measurement accuracy of the upper surface height of the substrate. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a processing device for carrying out a processing method according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing an example of a substrate to be processed by the processing device according to the embodiment. [Figure 3]FIG. 3 is a flowchart showing an example of the procedure of the processing method according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining an example of detecting the center of a substrate held on a holding table according to the embodiment. [Figure 5] FIG. 5 is a diagram for explaining the measurement step of the processing method according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining the processing steps of the processing method according to the embodiment. [Figure 7] FIG. 7 is a perspective view of a processing device suitable for carrying out a processing method according to a modified embodiment. [Figure 8] FIG. 8 is a diagram for explaining processing steps of a processing method according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0012] In the embodiments described below, an XYZ Cartesian coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ Cartesian coordinate system. One direction within a horizontal plane is defined as the X-axis direction, the direction perpendicular to the X-axis direction within the horizontal plane is defined as the Y-axis direction, and the direction perpendicular to both the X-axis and Y-axis directions is defined as the Z-axis direction. The XY plane containing the X-axis and Y-axis is parallel to the horizontal plane. The Z-axis direction perpendicular to the XY plane is the vertical direction.

[0013] [Embodiment] Fig. 1 is a perspective view of a processing device for carrying out a processing method according to an embodiment. The processing device 2 shown in Fig. 1 is a cutting device equipped with a back pressure sensor. The processing device 2 includes a pair of guide rails 6 mounted on a stationary base 4 and extending in the X-axis direction.

[0014] The X-axis moving block 8 is moved in the processing feed direction, i.e., the X-axis direction, by a processing feed unit (X-axis feed mechanism) 14 consisting of a ball screw 10 and a pulse motor 12. A holding table 20 is mounted on the X-axis moving block 8 via a cylindrical support member 22. The holding table 20 is, for example, a chuck table.

[0015] The holding table 20 has a suction holding portion 24 made of porous ceramics or the like. In the example shown in Fig. 1, the holding table 20 is provided with a plurality of clamps 26 (two in this embodiment) that clamp the annular frame. The holding table 20 further has a frame that surrounds the suction holding portion 24.

[0016] The processing feed unit 14 includes a scale 16 disposed on the stationary base 4 along the guide rail 6, and a read head 18 disposed on the underside of the X-axis moving block 8 for reading the X coordinate value of the scale 16. The read head 18 is electrically connected to the control unit 76 of the processing device 2.

[0017] The processing device 2 is fixed on a stationary base 4 and includes a pair of guide rails 28 extending in the Y-axis direction. The Y-axis moving block 30 is moved in the Y-axis direction by an indexing feed unit 36 ​​including a Y-axis feed mechanism composed of a ball screw 32 and a pulse motor 34. The operation of the indexing feed unit 36 ​​is controlled by a control unit 76.

[0018] A pair of guide rails 38 (only one shown) extending in the Z-axis direction are formed on the Y-axis moving block 30. The Z-axis moving block 40 is moved in the Z-axis direction by a Z-axis feed mechanism 44 composed of a ball screw and a pulse motor 42 (not shown).

[0019] The processing device 2 includes a processing unit 3. The processing unit 3 is a cutting unit 46. The cutting unit 46 has a spindle housing 48 inserted and supported in the Z-axis moving block 40. A spindle 47 is housed in the spindle housing 48 and rotatably supported by an air bearing. The spindle 47 is driven to rotate by a motor (not shown) housed in the spindle housing 48. A cutting blade 50 is detachably attached to the tip of the spindle 47, and the cutting blade 50 is rotated by the rotational drive.

[0020] A measuring unit 52 is mounted on the spindle housing 48. The measuring unit 52 has an imaging unit 54 that captures an image of the wafer held on the holding table 20. The cutting blade 50 and the imaging unit 54 are aligned in the X-axis direction.

[0021] A back pressure sensor 56 is attached to the measurement unit 52 to detect the height positions of the holding surface of the holding table 20 and the processing surface (upper surface) of the workpiece 100. The back pressure sensor 56 is configured to be indirectly fixed to the spindle housing 48 via the measurement unit 52. In this embodiment, the back pressure sensor 56 is an example of a measurement unit. Note that the back pressure sensor 56 may also be attached directly to the spindle housing 48.

[0022] The back pressure sensor 56 is equipped with a jet nozzle 58 that jets air toward the holding surface of the holding table 20 and the workpiece 100 held on the holding surface. The jet nozzle 58 is fixed to a piston rod 60 of an air cylinder 62 attached to the measurement unit 52.

[0023] The ejection nozzle 58 is connected to an air supply source 66 via a first path 64. The air supply source 66 is also connected to a second path 68. The second path 68 is open to the atmosphere via a throttle valve 70. Gas is supplied from the air supply source 66 to the first path 64 and the second path 68 in an appropriate ratio. The air flowing through the first path 64 is supplied to the ejection nozzle 58.

[0024] A differential pressure sensor 72 is connected between the first path 64 and the second path 68. The differential pressure sensor 72 includes a diaphragm 74. The diaphragm 74 is displaced in accordance with the difference between the pressure in the first path 64 and the pressure in the second path 68, and a voltage corresponding to the amount of displacement is output from the differential pressure sensor 72 to the control unit 76.

[0025] The voltage output when air is supplied from the air supply source 66 to the first path 64 and the second path 68 and there is no workpiece 100 in the direction of air ejection from the ejection port 58a of the ejection nozzle 58 can be set to 1 volt (1V), for example, by adjusting the restrictor 70 formed at the tip of the second path 68. The state where there is no workpiece 100 in the direction of air ejection from the ejection port 58a includes, for example, a state where there is a distance of 5 mm or more.

[0026] The ejection nozzle 58 has an ejection port 58a at the tip facing the workpiece 100, and by operating the air cylinder 62 and lowering the piston rod 60, the ejection port 58a can be brought closer to the workpiece 100, which is a substrate.

[0027] A limit switch 78 is disposed below the piston rod 60. The limit switch 78 limits the downward movement of the jet nozzle 58 and detects whether the jet nozzle 58 is in the operating position. The limit switch 78 is connected to the control unit 76, and detects whether the jet nozzle 58 is in the operating position or the non-operating position and notifies the control unit 76 of the result.

[0028] If there is no obstacle in the direction of air ejection from the ejection port 58a of the ejection nozzle 58, the first path 64 will also be open to the atmosphere, just like the second path 68, so the pressure in the first path 64 and the pressure in the second path 68 will be balanced, and the diaphragm 74 of the differential pressure sensor 72 will be in an equilibrium state. At this time, since the output voltage in the equilibrium state is set to 1V, the voltage value output from the differential pressure sensor 72 will be 1V.

[0029] On the other hand, when the outlet 58a of the ejection nozzle 58 approaches the workpiece 100, the outlet 58a becomes blocked by the workpiece 100, the pressure in the first path 64 changes, the equilibrium state of the diaphragm 74 is disrupted, and a voltage corresponding to the distance between the outlet 58a and the workpiece 100 is output from the differential pressure sensor 72.

[0030] The differential pressure sensor 72 is electrically connected to the control unit 76. The control unit 76 is also electrically connected to a memory unit 80. The control unit 76 reads the voltage value output by the differential pressure sensor 72 and stores it in the memory unit 80, and controls the pulse motor 42 of the Z-axis feed mechanism 44 during machining according to the value stored in the memory unit 80. The memory unit 80 stores in advance, for example, the relationship between the distance from the ejection port 58a of the ejection nozzle 58 to the machining surface of the workpiece 100 and the voltage output from the differential pressure sensor 72.

[0031] Therefore, the control unit 76 can determine the distance between the ejection port 58a of the ejection nozzle 58 and the processing surface 11a based on the voltage output from the differential pressure sensor 72 and the corresponding information stored in the memory unit 80. For example, when the output from the differential pressure sensor 72 is 5 V, the distance between the ejection port 58a and the processing surface 11a can be determined to be 100 μm.

[0032] The holding table 20 suction-holds the workpiece 100 on the holding surface 23 by suction from the suction holding section 24. The holding table 20 moves along the X-axis direction as the processing feed unit 14 moves along the X-axis direction. The holding table 20 can rotate around the Z-axis relative to the processing feed unit 14 by a rotation drive source (not shown).

[0033] The processing device 2 processes the workpiece 100 held on the holding surface 23. The processing device 2 cuts the workpiece 100 with a cutting blade 50 that rotates around the Y axis. The cutting blade 50 of the processing device 2 can be moved along the Y axis direction by the Y axis moving block 30, and can be moved along the Z axis direction by the Z axis moving block 40.

[0034] The processing device 2 cuts the workpiece 100 held on the holding table 20 along the planned division line by moving the holding table 20 and the cutting unit 46 relative to each other along the planned division line using the X-axis moving block 8, the Y-axis moving block 30, and the Z-axis moving block 40.

[0035] FIG. 2 is a perspective view showing an example of a substrate processed by the processing apparatus 2 according to the embodiment. As shown in FIG. 2, the workpiece 100 has a substrate 101 made of silicon, sapphire, gallium, or the like. The substrate 101 includes a disk-shaped semiconductor wafer or an optical device wafer. On an upper surface 102 of the substrate 101, devices 104 are formed in each chip region defined by a plurality of planned division lines (streets) 103 formed in a grid pattern. The substrate 101 has, on its surface, a device region 107 in which a plurality of devices 104 are formed, and a peripheral excess region 109 surrounding the device region 107. The direction in which the substrate 101 is attached to the annular frame is aligned with respect to a notch 105. The upper surface 102 of the substrate 101 refers to the surface on which the substrate 101 is processed.

[0036] In FIG. 2, a plurality of measurement positions 110-1, 110-2, 110-3, 110-4, and 110-5 can be set on the substrate 101. The plurality of measurement positions 110-1, 110-2, 110-3, 110-4, and 110-5 are set in a flat peripheral excess region 109 of the substrate 101. Each of the measurement positions 110-1, 110-2, 110-3, 110-4, and 110-5 is set using coordinates based on the center 130 of the substrate 101. Hereinafter, when there is no need to distinguish between the measurement positions 110-1, 110-2, 110-3, 110-4, and 110-5, they will be referred to as measurement positions 110 as appropriate. In the example shown in FIG. 2, five measurement positions 110 are set on the substrate 101, but the number of measurement positions 110 is not limited to this. The measurement position 110 may be a single coordinate or may be an area including multiple coordinates. The number of measurement positions 110 can be set appropriately depending on the workpiece 100.

[0037] Because the device region 107 of the substrate 101 has bumps and uneven patterns formed thereon, it is difficult to accurately measure the top surface height, and the measurement point for the top surface height of the substrate 101 may be specified as a specific location. In particular, when measuring using the back pressure sensor 56, the substrate 101 requires a flat area on the top surface 102 into which air can be sprayed, making accurate measurement impossible in the uneven device region. Furthermore, even if there are locations along the planned division lines where uneven patterns are not formed, accurate measurement is impossible if the width of the planned division lines is small. For this reason, the measurement points are limited to the peripheral excess region of the substrate 101 or specific locations in the device region 107 where a flat area can be secured. In this embodiment, the processing method provides a technology capable of accurately measuring the top surface height of the substrate 101.

[0038] Returning to FIG. 1, the control unit 76 controls each mechanism that drives the processing device 2. The control unit 76 controls each part of the processing device 2 to realize processing by the processing device 2. The control unit 76 realizes a processing method for the substrate 101 in which the processing unit 3 processes the substrate 101 along a plurality of planned dividing lines 013. An example of the processing method for the substrate 101 will be described later.

[0039] The control unit 76 includes, for example, a computer system. The control unit 76 has an arithmetic processing unit having a microprocessor such as a CPU (central processing unit), a storage device having memory such as a ROM (read only memory) or RAM (random access memory), and an input / output interface device. The arithmetic processing unit executes arithmetic processing in accordance with a computer program stored in the storage unit 80 or the like, and outputs control signals for controlling the processing device 2 to each component of the processing device 2 via the input / output interface device.

[0040] The memory unit 80 stores various data and programs. The memory unit 80 is realized by, for example, a semiconductor memory element such as RAM or flash memory, or a storage device such as a hard disk or optical disk. The memory unit 80 is configured to store computer programs and the like for causing the control unit 76 to execute the processing method for the workpiece 25. The memory unit 80 stores various information indicating the measurement results for each holding table 20, the measurement results for each of the multiple workpieces, etc. The memory unit 80 is electrically connected to the control unit 76.

[0041] The above describes an example of the configuration of the processing device 2 according to this embodiment. Note that the above configuration described using Fig. 1 is merely an example, and the configuration of the processing device 2 according to this embodiment is not limited to this example. The functional configuration of the processing device 2 according to this embodiment can be flexibly modified depending on the specifications and operation.

[0042] The processing device 2 according to this embodiment will be described as measuring the upper surface height using the back pressure sensor 56, but is not limited to this. For example, the processing device 2 may measure the upper surface height using an air gap sensor, an ultrasonic sensor, a depth camera, or the like.

[0043] (Substrate processing method) Next, a processing method for the substrate 101 executed by the processing device 2 will be described. Fig. 3 is a flowchart showing an example of the procedure of the processing method according to the embodiment. Fig. 4 is a diagram for explaining an example of detecting the center of the substrate 101 held on the holding table 20 according to the embodiment. Fig. 5 is a diagram for explaining a measurement step of the processing method according to the embodiment. Fig. 6 is a diagram for explaining a processing step of the processing method according to the embodiment.

[0044] 3 is realized by the control unit 76 of the processing device 2 executing a program. The processing method includes a setting step 1001, a holding step 1002, a center detection step 1003, a measurement step 1004, and a processing step 1005. The processing method executes the steps in the order of setting step 1001, holding step 1002, center detection step 1003, measurement step 1004, and processing step 1005.

[0045] First, setting step 1001 is a step of setting the position for measuring the height of the upper surface of the substrate 101 in polar coordinates based on the center of the substrate 101. The polar coordinates allow a point to be specified by the angle from the center of the substrate 101 and the distance from the center. The processing device 2 can rotate the polar coordinate system set on the substrate 101 by rotating the holding table 20 around the Z axis.

[0046] In setting step 1001, the processing apparatus 2 sets one or more measurement positions 110 on the upper surface 102 of the substrate 101 to be processed. For example, as shown in FIG. 2, the processing apparatus 2 sets the multiple measurement positions 110 on the upper surface 102 of the substrate 101 using polar coordinates, and stores setting information indicating the measurement positions 110 in a storage device. For example, the processing apparatus 2 can display an image showing the upper surface 102 of the substrate 101 on a touch panel or the like, and set the measurement positions 110 in accordance with operations on the image. For example, the processing apparatus 2 can obtain measurement position information capable of identifying measurement positions corresponding to the substrate 101 to be processed from a database or the like, and set the measurement positions 110 based on the measurement position information.

[0047] 3 , the holding step 1002 is a step of holding the substrate 101 on the holding table 20. In the holding step 1002, for example, when the substrate 101 of the workpiece 100 is placed on the holding surface 23 of the holding table 20, the processing device 2 sucks the substrate 101 on the holding surface 23 of the holding table 20 by using a suction source (not shown) connected to the holding surface 23 of the holding table 20.

[0048] The center detection step 1003 is a step for detecting the holding center of the substrate 101 held on the holding table 20. The holding center indicates the center of the substrate 101 in a state where it is actually held on the holding table 20. When the processing device 2 sequentially holds each of the multiple substrates 101 on the holding table 20, there is a possibility that the centers will not be at the same position on the holding table 20 due to errors, misalignment in placement, etc. For this reason, the center detection step 1003 detects the actual holding center of the substrate 101 held on the holding table 20.

[0049] In the center detection step 1003, the processing device 2 detects the holding center of the substrate 101 using a technique such as that described in Japanese Patent Application Laid-Open No. 2011-249572. As shown in FIG. 4, the processing device 2 captures an image 500 in which an edge 140 of the substrate 101 can be identified using the imaging unit 54, and detects three or more distinct edge positions 141 on the outer periphery of the substrate 101 through image processing. The multiple edge positions 141 may be determined appropriately based on, for example, the notch 105 of the substrate 101. The processing device 2 detects the holding center 150 of the substrate 101 based on the circumscribing circle of the triangle indicated by the multiple edge positions 141. After detecting the holding center 150 of the substrate 101, the processing device 2 stores coordinate information indicating the coordinates of the holding center 150 in a storage device.

[0050] 3, measuring step 1004 is a step of measuring the height of the upper surface of substrate 101 at the position set in setting step 1001, using as a reference the holding center 150 of substrate 101 detected in center detection step 1003. In measuring step 1004, processing device 2 determines a plurality of measurement positions 110 on upper surface 102 of substrate 101, using as a reference the holding center 150, as shown in FIG.

[0051] For example, in the setting step 1001, the setting information 400 is stored in the storage device. The setting information 400 includes polar coordinates (R-1, θ-1), (R-2, θ-2), (R-3, θ-3), (R-4, θ-4), and (R-5, θ-5) set for each of the five measurement positions 110-1, 110-2, 110-3, 110-4, and 110-5. R indicates the distance from the center of the substrate 101 to the measurement position 110. θ indicates the angle from a reference line passing through the center of the substrate 101 to the measurement position 110. The processing device 2 converts each of the polar coordinates (R-1, θ-1), (R-2, θ-2), (R-3, θ-3), (R-4, θ-4), and (R-5, θ-5) of the multiple measurement positions 110 into a polar coordinate system based on the holding center 150. Based on the conversion result, the processing apparatus 2 determines five measurement positions 110-1, 110-2, 110-3, 110-4, and 110-5 of the actually held substrate 101. The processing apparatus 2 positions the back pressure sensor 56 at each of the five measurement positions 110-1, 110-2, 110-3, 110-4, and 110-5 to measure the top surface height. As a result, even if the holding position of the substrate 101 relative to the holding table 20 is shifted, the back pressure sensor 56 can measure the top surface height at the flat measurement position 110 on the top surface 102 of the substrate 101, thereby improving measurement accuracy. The processing apparatus 2 associates the measured top surface height with the measurement position 110 of the substrate 101 and stores it in the storage device.

[0052] Returning to FIG. 3 , processing step 1005 is a step in which, after measuring step 1004, the processing unit 3 is operated according to the measured upper surface height to perform processing along the planned division line 103. In processing step 1005, as shown in FIG. 6 , the processing device 2 moves the cutting blade 50 in direction 2000, and causes the Z-axis moving block 40 to move the cutting blade 50 to the processing height at the planned division line 103 based on the upper surface height measured in measuring step 1004. This allows the processing device 2 to form a processed groove 160 of a desired depth based on the upper surface height in the upper surface 102 of the substrate 101 while suppressing deviation from the planned division line 103. Note that, in processing step 1005, if the upper surface height is measured at multiple locations in measuring step 1004, an average value of the measured values ​​may be set as the upper surface height and used for cutting. Alternatively, processing step 1005 may involve forming a top surface height map that calculates the slope of the top surface height of the entire substrate 101 based on the top surface heights at multiple locations, and processing while adjusting the processing height up and down using the Z-axis moving block 40 according to the top surface height map.

[0053] Returning to FIG. 3, when the processing of processing step 1005 is completed, the processing device 2 determines whether or not to terminate processing (determination step 1006). For example, the processing device 2 determines to terminate processing when processing of all of the multiple workpieces 100 has been completed. If the processing device 2 determines not to terminate processing (No in determination step 1006), it returns to the holding step 1002 and executes a series of steps from the holding step 1002 to the processing step 1005 for the next workpiece 100. On the other hand, if the processing device 2 determines to terminate processing (Yes in determination step 1006), it terminates the procedure of the processing method shown in FIG. 3.

[0054] As described above, when the processing apparatus 2 processes a plurality of substrates 101 sequentially, the processing method can measure the top surface height at the measurement position 110 based on the actual holding center 150 of the substrate 101 held on the holding table 20. Since the processing method can measure the top surface height at the measurement position 110 suitable for the substrate 101 held on the holding table 20, the substrate 101 can be accurately processed based on the top surface height. In the case of the processing apparatus 2 that measures the top surface height using the back pressure sensor 56, the processing method can accurately measure the flat top surface 102 of the substrate 101, thereby further improving the processing accuracy of the substrate 101.

[0055] In other words, when processing a plurality of substrates 101 sequentially, the processing device 2 can use the processing method to measure the top surface height at a measurement position 110 based on the actual holding center 150 of the substrate 101 held on the holding table 20. Since the processing device 2 can measure the top surface height at the measurement position 110 suitable for the substrate 101 held on the holding table 20, it can accurately process the substrate 101 based on the top surface height.

[0056] For example, when the processing apparatus 2 calculates coordinates based on the center of the holding table 20, if the holding position of the workpiece 100 shifts relative to the holding table 20, the measurement position 110 of the substrate 101 may shift. In contrast, the processing apparatus 2 according to the embodiment detects the center of the substrate 101 held on the holding table 20 and measures the top surface height of the substrate 101 at the measurement position 110 based on the center. This allows the processing apparatus 2 to improve the measurement accuracy of the top surface height of the substrate 101 regardless of the state of the substrate 101 held on the holding table 20. As a result, the processing apparatus 2 can process the substrate 101 based on the accurate top surface height, thereby improving the processing accuracy of the workpiece 100.

[0057] The processing apparatus 2 according to this embodiment includes a holding table 20, a processing unit 3, a measurement unit 52, a back pressure sensor 56, and a control unit 76, and can be configured so that the control unit 76 executes a method for processing a substrate 101. For example, the control unit 76 is configured to hold the substrate 101 on the holding table 20, detect a holding center 150 of the substrate 101 held on the holding table 20, measure the height of the upper surface of the substrate 101 at a measurement position 110 based on the holding center 150 of the substrate 101, operate the processing unit 3 according to the measured upper surface height, and process the substrate along the planned dividing line 103.

[0058] 3, the processing method has been described as a case in which the setting step 1001 is performed once, and then a series of steps from the holding step 1002 to the processing step 1005 are performed for each of the plurality of substrates 101, but this is not limiting. For example, the processing method may be a case in which a series of steps from the setting step 1001 to the processing step 1005 are performed for each of the plurality of substrates 101.

[0059] [Modification of the embodiment] A method for processing a substrate 101 according to a modified example of the above embodiment will be described below. FIG. 7 is a perspective view of a processing apparatus 2 suitable for carrying out the processing method according to the modified example of the embodiment. The processing apparatus 2 shown in FIG. 7 is a laser processing apparatus that irradiates a workpiece 100 with a laser beam. The processing apparatus 2 includes a holding table 20, a processing feed unit 14, an indexing feed unit 36, a measuring unit 52, a control unit 76, a memory unit 80, and a laser beam application unit 300.

[0060] Laser beam application unit 300 includes unit holder 301 and laser beam application means 302 attached to unit holder 301. Unit holder 301 is provided with a pair of guided grooves 511 that slidably fit into a pair of guide rails 38 provided on Y-axis moving block 30, and by fitting these guided grooves 511 into the guide rails 38, unit holder 301 is supported so as to be movable in the Z-axis direction.

[0061] The laser beam application means 302 includes a cylindrical casing 521 that is fixed to the unit holder 301 and extends substantially horizontally. A laser beam oscillation means (not shown) is disposed within the casing 521. A YAG laser oscillator or a YVO4 laser oscillator can be used as the laser beam oscillation means. The laser beam oscillation means irradiates a laser beam under the control of the control unit 76. A back pressure sensor 56 of the measurement unit 52 is fixed to one end of the casing 521.

[0062] The above describes an example of the configuration of the processing device 2 according to a modified example of this embodiment. Note that the above configuration described using Fig. 7 is merely an example, and the configuration of the processing device 2 according to this embodiment is not limited to this example. The functional configuration of the processing device 2 according to this embodiment can be flexibly modified depending on the specifications and operation.

[0063] (Substrate processing method according to modified example) Next, a description will be given of a method for processing the substrate 101 executed by the processing apparatus 2 according to the modified example. The processing apparatus 2 can use the flowchart showing an example of the procedure of the processing method shown in FIG.

[0064] 7 executes a program to realize a processing method. The processing method includes the above-described setting step 1001, holding step 1002, center detection step 1003, measurement step 1004, and processing step 1005. In the processing method according to the modified example, processing step 1005 is changed as follows.

[0065] 8 is a diagram illustrating the processing steps of a processing method according to a modified example of the embodiment. In processing step 1005, the processing device 2 moves the laser beam application unit 300 in direction 2000, as shown in FIG. 8, and positions the laser beam application unit 300 at the processing height for each of the planned division lines 103 based on the upper surface height measured in measuring step 1004. The processing device 2 irradiates the substrate 101 with a laser beam having a wavelength that is adsorbable to the substrate, thereby forming processed grooves 160 on the upper surface 102 of the substrate 101 while suppressing deviation from the planned division lines 103.

[0066] If the processing device 2 determines not to end processing (No in decision step 1006), it returns to the holding step 1002 and executes a series of steps from the holding step 1002 to the processing step 1005 on the next workpiece 100. On the other hand, if the processing device 2 determines to end processing (Yes in decision step 1006), it ends the procedure of the processing method shown in FIG.

[0067] As described above, the processing apparatus 2 according to the modified embodiment can improve the measurement accuracy of the top surface height of the substrate 101 regardless of the state of the substrate 101 held on the holding table 20. As a result, the processing apparatus 2 can accurately process the substrate 101 with a laser beam based on the accurate top surface height, thereby improving the processing accuracy of the workpiece 100.

[0068] Furthermore, the processing step 1005 of the processing method may be performed by irradiating the substrate 101 with a laser beam having a wavelength that is transparent to the substrate. In this case, the processing device 2 forms a modified layer inside the substrate 101 by irradiating the substrate 101 with a laser beam having a wavelength that is transparent to the substrate while moving the laser beam application unit 300 along the planned dividing lines 103. In this way, the processing device 2 can suppress deviation from the planned dividing lines 103 by irradiating the substrate 101 with a laser beam having a wavelength that is adsorbable to the substrate 101, and can accurately form a modified layer inside the substrate 101.

[0069] The present invention is not limited to the above-described embodiment, and can be implemented in various modifications without departing from the gist of the present invention.

[0070] In the embodiment, an example has been described in which the back pressure sensor 56 is used as the measurement unit used in the measurement step, but the measurement unit used in the measurement step is not limited to this, and may be a contact displacement sensor, an optical displacement sensor, an image sensor type displacement sensor, or the like. [Explanation of symbols]

[0071] 2 Processing equipment 3 Processing Unit 14 Processing feed unit 20 Holding table 23 Holding surface 25 Workpiece 36 Indexing feed unit 47 Spindle 50 cutting blades 52 Measuring Unit 76 Control Unit 80 Storage section 101 Substrate 103 Planned division line 110 Measurement position 150 Holding Center 300 Laser beam irradiation unit

Claims

1. A substrate processing method in which a substrate is processed along a plurality of planned dividing lines by a processing unit, a setting step of setting a position for measuring the height of the upper surface of the substrate at a location where a flat area can be ensured on the upper surface of the substrate on which the pattern is formed, and setting the position using coordinates with the center of the substrate as a reference; a holding step of holding the substrate on a holding table; a center detecting step of detecting the center of the substrate held on the holding table; a measuring step of measuring the height of the upper surface of the substrate at the position set in the setting step with reference to the center of the substrate detected in the center detecting step; a processing step of operating the processing unit according to the measured upper surface height after the measuring step, and processing along the planned dividing line; A substrate processing method comprising:

2. A method for processing a substrate as described in claim 1, wherein the setting step sets the position for measuring the top surface height of the substrate at a location where a flat area can be secured on the top surface of the substrate on which the pattern is formed, and sets it at coordinates excluding the center of the substrate based on the center of the substrate.

3. A method for processing a substrate as described in claim 1, wherein the setting step sets the position for measuring the top surface height of the substrate at a location where a flat area can be secured in the peripheral excess area of ​​the top surface of the substrate on which the pattern is formed, and sets it at coordinates based on the center of the substrate.

4. The processing unit comprises: a cutting unit that cuts the substrate by moving a cutting blade relative to the substrate; 2. The method for processing a substrate according to claim 1, wherein the cutting groove is formed in the substrate by adjusting the cutting height of the cutting blade in accordance with the height measured in the measuring step.

5. The processing unit comprises: a laser beam irradiation unit that irradiates a laser beam onto a substrate; 2. The substrate processing method according to claim 1, wherein the height at which the laser beam is focused is adjusted according to the height measured in the measuring step, and a processed groove or a modified layer is formed in the substrate.

6. A method for processing a substrate as described in Claim 4, characterized in that in the processing step, if the top surface height is measured at multiple locations in the measurement step, the average of the multiple measured values ​​is set as the top surface height and cutting is performed.

7. A method for processing a substrate as described in claim 1, characterized in that the processing step forms a top surface height map that calculates the slope of the top surface height of the entire substrate based on the top surface heights at multiple locations, and processes the substrate according to the top surface height map.

8. A method for processing a substrate as described in claim 1, characterized in that the measurement step measures the top surface height of the substrate by positioning a back pressure sensor at a position set in the setting step based on the center of the substrate detected in the center detection step.

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