Machining device

Abstract

To provide a machining device capable of removing a chamfered part with such high accuracy that slightly exceeds a finish thickness, which is obtained by grinding a rear face of a wafer.SOLUTION: In a machining device, control means 100 is configured to: position height measurement means 20 in an outer periphery of a wafer 10 corresponding to angles from 0 degree to one round while rotating a chuck table 7; measure a depth of a step part obtained by cutting a chamfered part 15 of the wafer by cutting means 8 correspondingly to a finish thickness of the wafer; store a depth DZ of the step part for each angle; measure a width W in a radial direction, of the step part; store, for each angle while positioning a camera 21 in the outer periphery of the wafer; combine, for each angle, the measured values to generate a three-dimensional composite image; and causes display means 24 to display the generated image.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a processing apparatus for a wafer having a device area, in which a plurality of devices are partitioned by planned division lines, and a peripheral excess area, which has a chamfered portion surrounding the device area, formed on its surface. [Background technology]

[0002] A wafer has a plurality of devices such as ICs and LSIs formed on its surface, separated by planned dividing lines. The back surface is ground to a predetermined thickness, and then the wafer is divided into individual device chips using a dicing machine, which are then used in electrical equipment such as mobile phones and personal computers.

[0003] The grinding device is configured to include a chuck table for holding a wafer, a grinding means having a rotatable grinding wheel with a ring-shaped arrangement of grinding stones for grinding the wafer held on the chuck table, a feeding means for feeding the grinding means for grinding, and a measuring means for measuring the thickness of the wafer, and is capable of grinding the wafer to a desired thickness.

[0004] However, a chamfer is formed on the outer periphery of the wafer, and when the back surface of the wafer is ground to thin it, the chamfer becomes a sharp knife edge, which causes cracks that originate from the outer periphery to extend into the device region where multiple devices are separated by the planned division lines, damaging the devices and posing a risk of injury to the operator.

[0005] Therefore, the present applicant has proposed a technique for removing the chamfered portion before grinding the back surface of the wafer (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-096295 Summary of the Invention [Problem to be solved by the invention]

[0007] In particular, in the case of two-layer wafers, before stacking the wafers, the chamfered portion of one wafer whose backside is ground is removed, and then the front side of the chamfered wafer is stacked on the other wafer. However, if the entire chamfered portion of one wafer is removed, it is difficult to accurately align the center of the one wafer with the center of the other wafer, so it is necessary to leave more than half of the chamfered portion of one wafer. However, there is a problem in that it is difficult to accurately cut and remove the chamfered portion from the front side of one wafer so that the thickness is slightly greater than the finished thickness obtained by grinding the back side of the one wafer.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and its main technical object is to provide a processing apparatus capable of removing a chamfered portion with such high precision that the thickness slightly exceeds the finished thickness obtained by grinding the back surface of a wafer. [Means for solving the problem]

[0009] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a processing apparatus for a wafer having a surface formed with a device region in which a plurality of devices are partitioned by planned division lines and a peripheral excess region having a chamfered portion surrounding the device region, the processing apparatus comprising: a rotatable chuck table having a holding surface defined by X and Y axes for suction-holding the wafer; cutting means having a rotation axis in the Y-axis direction for supporting a cutting blade that cuts the chamfered portion of the wafer held by suction on the chuck table to a thickness corresponding to the finished thickness of the wafer and forms a step portion; Z-axis feeding means for feeding the cutting means in the Z-axis direction perpendicular to the holding surface; height measuring means for measuring the height of the top surface of the wafer held by suction on the chuck table; a camera for measuring the width of the step portion in the radial direction; control means; and display means, wherein the control means sets the cutting depth in the Z-axis direction of the chamfered portion to be cut from the surface of the wafer held by suction on the chuck table. a surface coordinate storage unit that operates the height measurement means to measure and store the Z-axis coordinate of the wafer surface; a chamfering operation unit that performs processing to cut the chamfered portion based on the cut depth set by the cut depth setting unit, the width set by the width setting unit, and the Z-axis coordinate stored in the surface coordinate storage unit; a depth storage unit that, after cutting of the chamfered portion by the chamfering operation unit is completed, positions the height measurement means on the outer periphery of the wafer corresponding to an angle from 0 degrees to one revolution while rotating the chuck table, measures the depth of the stepped portion and stores the depth of the stepped portion for each angle; a width storage unit that positions the camera on the outer periphery of the wafer, measures the radial width of the stepped portion and stores the measured values for each angle; and a three-dimensional image generation unit that generates a three-dimensional composite image by combining the measurement values stored in the depth storage unit and the width storage unit for each angle and displays the composite image on the display means.

[0010] The control means can rotate the 3D composite image while displaying it on the display means. The control means can also partially enlarge the 3D composite image and display it on the display means. Furthermore, it is preferable that the control means includes an attention information recording unit that records attention information when a noteworthy portion is found based on the 3D composite image.

[0011] The control means may be configured to display, in different colors, the difference between the measurement values stored in the depth memory unit and the width memory unit based on the cutting depth set by the cutting depth setting unit and the width set by the width setting unit. The control means may also be configured to display a line for slicing the 3D composite image, and to display a cross-sectional view and measurement values corresponding to the slicing line. Furthermore, the control means may be configured to include a processing time information recording unit that records processing time information of the cutting means when executing a chamfering operation unit that cuts a chamfered portion.

[0012] The control means may be configured to prompt maintenance of the cutting blade. The control means may also be configured to continuously display a three-dimensional composite image of a plurality of wafers on the display means. [Effects of the Invention]

[0013] The processing apparatus of the present invention includes a rotatable chuck table having a holding surface defined by X and Y axes for suction-holding a wafer, cutting means having a rotation axis in the Y-axis direction for supporting a cutting blade for cutting the chamfered portion of the wafer held by suction on the chuck table to a thickness corresponding to the finished thickness of the wafer and forming a step portion, Z-axis feeding means for processing and feeding the cutting means in the Z-axis direction perpendicular to the holding surface, height measuring means for measuring the height of the top surface of the wafer held by suction on the chuck table, a camera for measuring the radial width of the step portion, control means, and display means, wherein the control means includes a cutting depth setting unit for setting the cutting depth in the Z-axis direction of the chamfered portion to be cut from the surface of the wafer held by suction on the chuck table, a width setting unit for setting the radial width of the chamfered portion to be cut, a surface coordinate storage unit for operating the height measuring means to measure and store the Z-axis coordinate of the surface of the wafer, and a cutting depth set by the cutting depth setting unit. a chamfering operation unit that performs processing to cut a chamfered portion based on the width set by the width setting unit and the Z-axis coordinate stored in the surface coordinate storage unit; a depth storage unit that, after cutting of the chamfered portion by the chamfering operation unit is completed, positions the height measurement means on the outer periphery of the wafer corresponding to an angle from 0 degrees to one revolution while rotating the chuck table, measures the depth of the step portion and stores the depth of the step portion for each angle; a width storage unit that positions the camera on the outer periphery of the wafer, measures the radial width of the step portion and stores the measured value for each angle; and a 3D image generation unit that generates a 3D composite image by synthesizing the measurement values stored in the depth storage unit and the width storage unit for each angle, and displays the image on the display means.As a result, it is possible to intuitively view the step portion formed by the chamfering processing and easily check the condition of the step portion, and it is possible to perform chamfering processing to remove the chamfered portion with high precision that slightly exceeds the finished thickness obtained by grinding the back surface of the wafer. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is an overall perspective view of a processing device according to an embodiment of the present invention; [Figure 2](a) A conceptual diagram showing the connection between the control means and each operating unit arranged in the processing apparatus shown in Figure 1, (b) an oblique view of the wafer which is the workpiece, and (c) an enlarged partial cross-sectional view showing the cutting depth DZ in the Z-axis direction of the chamfered portion to be cut from the surface of the wafer, which are set in the control means, the radial width W of the chamfered portion to be cut, and the Z-axis coordinate Z1 of the surface of the wafer. [Figure 3] 2 is a perspective view showing a manner in which a wafer is placed on a chuck table of the processing apparatus shown in FIG. 1. FIG. [Figure 4] FIG. 1A is a perspective view showing a mode for measuring the surface height of a wafer, and FIG. 1B is a side view of the chuck table and height measuring means shown in FIG. [Figure 5] FIG. 1A is a perspective view showing a mode of performing chamfering, and FIG. 1B is a cross-sectional view showing an enlarged portion of the chamfering shown in FIG. [Figure 6] (a) A partially enlarged cross-sectional view showing how the depth of a step portion is measured using a height measurement means, (b) a partially enlarged cross-sectional view showing how the width of a step portion is measured using a camera, and (c) a conceptual diagram for explaining 0 degrees, which is the reference for the wafer being measured, and the rotation angle. [Figure 7] FIG. 10 is a conceptual diagram of a storage table in which information on a depth storage section and a width storage section is stored. [Figure 8] (a) is a conceptual diagram showing an overview of a display mode M-1, (b) is a conceptual diagram showing an overview of a display mode M-2, and (c) is a conceptual diagram showing an overview of a display mode M-3. [Figure 9] FIG. 10 is a conceptual diagram showing an overview of a display mode M-4. [Figure 10] FIG. 10 is a conceptual diagram showing an overview of a display mode M-5. [Figure 11] FIG. 10 is a conceptual diagram showing an overview of a display mode M-6. [Figure 12] FIG. 10 is a conceptual diagram showing an overview of a display mode M-7. [Figure 13] FIG. 10 is a conceptual diagram showing an overview of a display mode M-8. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a processing apparatus configured based on the present invention will be described in detail with reference to the accompanying drawings.

[0016] 1 shows a perspective view of a processing apparatus 1 according to this embodiment. The workpiece processed by the illustrated processing apparatus 1 is, for example, a semiconductor wafer 10. The processing apparatus 1 includes a housing 2, a chuck table 7 having a holding surface 7a for holding the wafer 10, cutting means 8 for cutting the chamfered portion of the wafer 10 held on the chuck table 7 to a thickness corresponding to the finished thickness of the wafer 10 to form a step portion, Z-axis feeding means (not shown) for feeding the cutting means 8 in the Z-axis direction perpendicular to the holding surface 7a, height measuring means 20 for measuring the height of the top surface of the wafer 10 held by suction on the chuck table 7, a camera 21 for measuring the radial width of the step portion, display means 24, and control means 100.

[0017] The holding surface 7a of the chuck table 7 is defined by the X-axis and Y-axis and is made of a breathable material. The chuck table 7 is connected to a suction means (not shown), and by operating the suction means, a negative pressure is generated on the holding surface 7a, allowing the wafer 10 to be suction-held. The chuck table 7 is configured to be rotatable by a pulse motor (not shown). It also includes an X-axis feed means (not shown) that moves the chuck table 7 in the X-axis direction.

[0018] The cutting means 8 is provided with a rotary shaft 82 in the Y-axis direction that supports a cutting blade 81 at its tip, and the rotary shaft 82 is driven by a spindle motor (not shown). The cutting means 8 also has a Y-axis feed means (not shown) that moves the cutting blade 81 in the Y-axis direction. The thickness of the cutting blade 81 is preferably set to a thickness that corresponds to or is greater than the width of the chamfered portion 15 of the wafer 10 that is to be cut and removed, and a cutting blade having a thickness of, for example, 3.0 mm is selected.

[0019] In addition to the above-mentioned configuration, the processing apparatus 1 shown in Figure 1 is equipped with a cassette 4 placed on a cassette table 4a that can be raised and lowered and arranged in the housing 2, a transfer means 3 that transfers the wafer 10 from the cassette 4 to a temporary storage table 5, a transfer means 6 having a swivel arm that transfers the wafer 10 that has been transferred to the temporary storage table 5 to a chuck table 7, and a cleaning and transfer means 23 that transfers the wafer 10 from the transfer position where the chuck table 7 is positioned in Figure 1 to a cleaning apparatus 22 (details omitted).

[0020] The height measurement means 20 can be a known height measurement means, and can, for example, irradiate the surface of the object to be measured with a laser beam emitted from a light source (not shown), receive reflected light from the surface and returned light from a reference surface that serves as a height reference, generate interference light, and analyze the interference light to precisely measure the height of the surface. The camera 21 is, for example, a line camera, which can scan the imaged area in a straight line to obtain an image of a straight line.

[0021] 2(a) shows a control means 100 and the components connected to the control means 100. The control means 100 is connected to a pulse motor that rotates the chuck table 7, an X-axis feed means that moves the chuck table 7 in the X-axis direction, the cutting means 8, the height measurement means 20, the camera 21, and the display means 24. The control means 100 is configured by a computer and includes a central processing unit (CPU) that performs calculations according to a control program, a read-only memory (ROM) that stores the control program, a read-write random access memory (RAM) that temporarily stores information obtained by the height measurement means 20 and the camera 20, calculation results, and the like, an input interface, and an output interface (details not shown). The pulse motor that rotates the chuck table 7 and the X-axis feed means, as well as the Y-axis feed means, the Z-axis feed means, and the spindle motor provided in the cutting means 8, are controlled by the control means 100. In addition, the chuck table 7 and the cutting means 8 are provided with position measurement means (not shown), which detect the rotation angle and X-coordinate position of the chuck table 7, and the Y-axis coordinate position and Z-axis coordinate position of the cutting means 8, thereby enabling precise control of the positions of the chuck table 7 and the cutting blade 81 of the cutting means 8.

[0022] 2(b) shows a wafer 10 to be processed in this embodiment. The wafer 10 is a semiconductor wafer made of silicon (Si) having, for example, a diameter of 300 mm and a thickness of 750 μm. The wafer 10 has, on its surface 10a, a device region 16 in which a plurality of devices 12 are partitioned by planned division lines 14, and a peripheral surplus region 17 having a chamfered portion 15 surrounding the device region 16. A division line 18 (two-dot chain line) is shown on the surface 10a of the wafer 10 in the figure, dividing the device region 16 and the peripheral surplus region 17. However, the division line 18 is an imaginary line added for convenience of explanation and is not actually disposed on the surface 10a of the wafer 10. A notch 19 indicating the crystal orientation of the wafer 10 is formed on the outer periphery of the peripheral surplus region 17.

[0023] Returning to FIG. 2(a), the control means 100 includes a cutting depth setting unit 110 that sets a cutting depth DZ for cutting the chamfered portion 17 to be cut in the Z-axis direction from the front surface 10a of the wafer 10 held by suction on the chuck table 7, a width setting unit 120 that sets a width W in the radial direction of the chamfered portion 15 to be cut, and a surface coordinate storage unit 130 that operates the height measurement means 20 to measure and store a Z-axis coordinate Z1 indicating the height of the front surface 10a of the wafer 10 (see also FIG. 2(c)). The control means 100 also includes a cutting depth setting unit 110 that sets a cutting depth DZ for cutting the chamfered portion 17 in the Z-axis direction from the front surface 10a of the wafer 10 held by suction on the chuck table 7, a width setting unit 120 that sets a width W in the radial direction of the chamfered portion 15 to be cut, and a surface coordinate storage unit 130 that operates the height measurement means 20 to measure and store a Z-axis coordinate Z1 indicating the height of the front surface 10a of the wafer 10 (see also FIG. 2(c)). a depth memory unit 150 that, after cutting of the chamfered portion 15 by the chamfering operation unit 140 is completed, positions the height measurement means 20 on the outer periphery of the wafer 10 while rotating the chuck table 7, measures the depth of the step portion formed by the cutting means 8 corresponding to an angle (360 degrees) from 0 degrees based on the position of the notch 19, and stores the depth of the step portion for each angle; a width memory unit 160 that positions the camera 21 on the outer periphery of the wafer 10, measures the radial width of the step portion, and stores the measured value for each angle; and a three-dimensional image generation unit 170 that combines the measurement values stored in the depth memory unit 150 and the width memory unit 160 for each angle, generates a three-dimensional composite image, and displays the image on the display unit 24. Furthermore, the control means 100 is equipped with an attention information recording unit 180 that records attention information when a noteworthy portion is found based on the 3D composite image, and a processing information recording unit 190 that records information at the time of processing when removing the chamfered portion 15.

[0024] The processing device 1 of this embodiment has roughly the configuration as described above, and the function and action of each component in the processing device 1 will be described in more detail.

[0025] The processing device 1 described above performs chamfering processing by cutting and removing the chamfered portion 15 based on the cutting depth DZ set in the cutting depth setting unit 110, the width W set in the width setting unit 120, and the Z-axis coordinate Z1 stored in the surface coordinate memory unit 130.

[0026] More specifically, when performing chamfering using the cutting means 8 of the processing apparatus 1 described with reference to FIG. 1 , the cutting depth setting unit 110 of the control means 100 sets the cutting depth DZ in the Z-axis direction of the chamfered portion 15 to be cut from the front surface 10a of the wafer 10 held by suction on the chuck table 7. This cutting depth DZ is set to a value slightly exceeding the finished thickness obtained by grinding the back surface 10b of the wafer 10 using a grinding device (not shown) after the chamfered portion 15 has been cut and removed by the processing apparatus 1 of this embodiment, and is set to a thickness that leaves more than half the thickness of the chamfered portion 15. In this embodiment, the cutting depth DZ is 350 μm, which is input in advance by the operator and stored in the cutting depth setting unit 110. Furthermore, the width setting unit 120 of the control means 100 sets the radial width W of the chamfered portion 15 to be cut. The width W is, for example, 2360 μm, which is input in advance by the operator and stored.

[0027] As described above, once the cutting depth DZ in the Z-axis direction of the chamfered portion 15 to be cut and the radial width W of the chamfered portion 15 to be cut are set, the wafer 10 stored in the cassette 4 is transferred to the temporary placement table 5 by the transfer means 3, and then transferred from the temporary placement table 5 to the chuck table 7, which is positioned at the front transfer position in FIG. 1, by the transfer means 6. Then, as shown in FIG. 3, the back surface 10b of the wafer 10 is placed on the holding surface 7a of the chuck table 7 facing downward, and the suction means (not shown) is activated to hold the wafer 10 by suction. Next, as shown in FIGS. 4(a) and 4(b), the X-axis feed means is activated to position the peripheral excess region 17 of the front surface 10a of the wafer 10, where the chamfered portion 15 is formed, directly below the height measurement means 20. Next, the height measurement means 20 is activated to measure the height of the front surface 10a of the wafer 10 at the peripheral excess region 17. The Z-axis coordinate Z1 indicating the height of the surface 10a of the wafer 10 obtained by the measurement is stored in the surface coordinate storage unit 130 of the control means 100.

[0028] Furthermore, the camera 21 captures an image of the peripheral excess area 17 of the wafer 10, and the chuck table 7 is rotated to detect the position coordinates of the multiple peripheral edge portions where the chamfered portions 15 of the wafer 10 are formed. At this time, the position coordinates of the notch 19 are detected, and the position of the notch 19 is set as the reference (0 degrees) for the rotation direction.

[0029] As described above, once the cutting depth DZ is set by the cutting depth setting unit 110, the width W is set by the width setting unit 120, and the Z-axis coordinate Z1 of the height of the surface 10a of the wafer 10 is measured by the height measuring means 20, the chamfering operation unit 140 of the control means 100 is activated to perform chamfering processing, which cuts and removes the chamfered portion 15.

[0030] More specifically, as shown in FIG. 5( a), the X-axis feed means is operated to position the chuck table 7 directly below the cutting means 8, and the cutting blade 81 of the cutting means 8 is positioned above the chamfered portion 15 of the wafer 10. At this time, the Y-axis feed means is operated to move the cutting means 8 in the direction indicated by arrow R1, and the cutting blade 81 is positioned at a position where the cutting blade 81 cuts the radial width W of the chamfered portion 15 from the outer peripheral edge of the wafer 10. Then, while rotating the chuck table 7, the spindle motor of the cutting means 8 (not shown) is operated to rotate the rotary shaft 82, rotating the cutting blade 81 at high speed in the direction indicated by arrow R2, and the Z-axis feed means is operated to feed the cutting means 8 in the direction indicated by arrow R3. The amount of cutting at this time is a preset cutting depth DZ (350 μm) based on the Z-axis coordinate Z1 stored in the surface coordinate memory unit 130. While operating the cutting means 8 in this manner, the chuck table 7 is rotated at least once (360 degrees) or multiple times (see also Figure 5(b)), whereby the chamfered portion 15 formed in the peripheral excess area 17 of the wafer 10 is cut and removed, forming a step portion 11 along the entire periphery of the wafer 10.

[0031] After the chamfering operation by the chamfering operation unit 140 described above is performed and the chamfering process of cutting and removing the chamfered portion 15 is completed, the chuck table 7 is moved in the X-axis direction, and the height measurement unit 20 is positioned above the peripheral excess region 17 of the wafer 10, as shown in FIG. 6(a). Next, while rotating the chuck table 7, the depth of the step portion 11 formed on the outer periphery of the wafer 10 is measured corresponding to an angle from 0 degrees to one full rotation angle (360 degrees) based on the notch 19 shown in FIG. 6(c), and the depth of the step portion 11 for each angle (for example, every 5 degrees) is stored in the depth storage unit 150 of the control unit 100. Note that the depth of the step portion 11 is measured not only at one location in the radial direction, but also at multiple locations, for example, at 50 μm intervals, within a range W in the radial direction.

[0032] Once the depth of the step portion 11 has been stored as described above, the camera 21 is positioned on the outer periphery of the wafer 10 on which the step portion 11 is formed, as shown in Figure 6(b), and images are taken while rotating the chuck table 7. The radial width of the step portion 11 formed on the outer periphery of the wafer 10 is measured corresponding to an angle from 0 degrees to one full rotation angle (360 degrees) based on the notch 19 shown in Figure 6(c), and the width of the step portion 11 for each angle is stored in the width memory unit 160 of the control means 100.

[0033] The information on the depth of the stepped portion 11 measured as described above and the radial width of the stepped portion 11 that is measured and stored in the depth memory unit 150 and width memory unit 160 can be stored, for example, in the form of a memory table 200 shown in Fig. 7. As described above, the depth of the stepped portion 11 that is stored in the depth memory unit 150 is measured at multiple locations in the radial direction, and the memory table 200 of this embodiment shown in Fig. 7 is configured to display the shape of the stepped portion 11 as a two-dimensional image based on the measured depth information.

[0034] The control means 100 can display various information on the display means 24 based on the measurement values stored in the depth storage unit 150 and the width storage unit 160. Below, the display forms that the control means 100 in the processing device 1 of this embodiment can display on the display means 24 will be explained. Each display mode explained below can be selected from a menu screen (not shown), and can be appropriately selected and displayed based on the information required by the operator.

[0035] (Display mode M-1) The control means 100 is equipped with a three-dimensional image generation unit 170, which can generate a three-dimensional composite image showing the wafer 10 by combining the measurement values stored in the depth storage unit 150 and the width storage unit 160 for each angle of the wafer 10. In display mode M-1 shown in FIG. 8(a), the three-dimensional composite image of the wafer 10 generated as described above can be displayed on the display means 24. In this display mode M-1, the measurement results of the depth and width of the step portion 11 formed by cutting and removing the chamfered portion 15 are expressed by the unevenness of the three-dimensional composite image, allowing the state of the step portion 11 to be intuitively viewed.

[0036] Furthermore, in the display mode M-1 of this embodiment, it is possible to rotate the wafer 10 in the direction indicated by the arrow R4 in the figure, and if the display means 24 is configured as a touch panel, it is possible to view the state of the step portion 11 formed on the wafer 10 over the entire circumference by directly touching the display means 24 and tracing in the direction indicated by the arrow R4.

[0037] (Display mode M-2) The control means 100 can partially enlarge the above-mentioned 3D composite image and display it on the display means 24, as in the display mode M-2 shown in FIG. 8(b). For example, as shown in the figure, a partial enlargement area S1 is set at one location on the display means 24, and the area corresponding to the partial enlargement area S1 is partially enlarged and displayed on the display means 24. As described above in the description of the display mode M-1, the 3D composite image of the wafer 10 can be rotated on the display means 24 in the direction indicated by the arrow R4. By changing the position corresponding to the partial enlargement area S1 set on the display means 24, the step portion 11 can be enlarged and displayed over the entire circumference of the wafer 10. By enlarging and displaying a portion in this manner, the operator can view the area he or she wishes to check in more detail. The magnification for the enlarged display can also be changed as appropriate, and the magnification can be adjusted as needed. Although not shown in the figure, the rotational position of the partially enlarged and displayed area from the reference position of the wafer 10 (the position of the notch 19 in this embodiment) may also be displayed.

[0038] (Display mode M-3) The control means 100 includes a noteworthy information recording unit 180 that records a noteworthy location as noteworthy information when the location is found based on the above-described 3D composite image. A typical example of noteworthy information is a chipping (chipping) that occurs on the outer periphery of the wafer 10 due to the chamfering process, as shown by P1 in the display mode M-3 in FIG. 8(c). When a chipping location P1 to be designated as noteworthy information is found in the display mode M-1, the operator can record the reason for the chipping, such as the presence or size of the chipping, along with its position information (angle). The noteworthy information recorded in the noteworthy information recording unit 180 is not limited to the above-described chipping. For example, a location where the depth of the step portion 11 is significantly poor or a location where the width of the step portion 11 is significantly poor may be recorded as noteworthy information. Furthermore, the location recorded as noteworthy information can be appropriately enlarged for display. Furthermore, in display mode M-3 of this embodiment, as explained based on display mode M-1, the displayed three-dimensional composite image can be rotated in the direction indicated by arrow R4, and even if there are multiple pieces of information of interest, the appropriate location can be displayed in the foreground, and the contents of the information of interest can be displayed sequentially.

[0039] (Display mode M-4) As shown in display mode M-4 in FIG. 9 , the control unit 100 can display on the display unit 24 the difference between the measurement values stored in the depth memory unit 150 and the width memory unit 160 using color gradation based on the cutting depth DZ set by the cutting depth setting unit 110 and the width W set by the width setting unit 120. For example, in the step portion 11 shown in the figure, the darker areas represent areas deeper than the reference cutting depth DZ, while the lighter areas represent areas shallower than the reference cutting depth DZ. By displaying in this manner, it is possible to intuitively determine whether the chamfering process of cutting and removing the chamfered portion 15 to form the step portion 11 was performed correctly. If necessary, a partial area may be enlarged and displayed, as shown in display mode M-2. Furthermore, when displaying the step portion 11 of the wafer 10 in this display mode M-4, the reference cutting depth DZ and the position of the width W set in the width setting unit 120 may be superimposed on the 3D composite image of the wafer 10 and displayed semi-transparently on the display means 24. By displaying in this manner, it is possible to intuitively view areas where the cutting is deeper or shallower than the target, or areas where the cutting is wider or narrower than the target. Furthermore, in display mode M-4 of this embodiment, as described based on display mode M-1, the displayed 3D composite image can be rotated in the direction indicated by arrow R4, allowing intuitive viewing of the entire circumference to determine whether the chamfering process for forming the step portion 11 of the wafer 10 was performed correctly.

[0040] As shown in display mode M-5 in FIG. 10, the control unit 100 can display an AA line slicing the above-described three-dimensional composite image, and can display a cross-sectional view of the step portion 11 corresponding to the AA line, a measured value of the width W of the step portion 11, and a measured value of the cutting depth DZ. In display mode M-5, the angle of the position sliced by the AA line (in the illustrated embodiment, the angle is 300 degrees) is also displayed. In display mode M-5 of this embodiment, as described based on display mode M-1, the three-dimensional composite image can be rotated in the direction indicated by arrow R4. A desired angular position can be positioned on the AA line slicing, and a cross-sectional view of the step portion 11 at the desired angle, a measured value of the width W of the step portion 11, and a measured value of the cutting depth DZ can be displayed. This allows the cross-sectional view of the step portion 11, a measured value of the width W of the step portion 11, and a measured value of the cutting depth DZ to be displayed over the entire circumference. If necessary, a graph showing the change in each measurement value before and after the specified angle and an image of the camera 21 at any angle can be displayed together with the above cross-sectional view. In addition, in display mode M-5, information related to the processing conditions when cutting the chamfered portion 15, such as the rotation direction of the cutting blade 81, the rotation direction of the chuck table 7, and the rotation speed of the chuck table 7, can be displayed using animated animation, characters, figures such as arrows, color changes, etc.

[0041] The control means 100 includes a processing information recording unit 190 that records processing information when the cutting means 8 removes the chamfered portion 15 to form the stepped portion 11. The control means 100 can appropriately display the processing information recorded in the processing information recording unit 190, as in display mode M-6 shown in FIG. 11 . The processing information recording unit 190 records, for example, the load current value of the spindle motor that drives the rotary shaft 82 of the cutting means 8, the flow rate of cutting water supplied to the cutting location, and the rotation speed of the chuck table 7 (indicated by C / T in the figure) for each rotation angle with the notch 19 of the wafer 10 as the reference (0 degrees), and each piece of information is displayed in display mode M-6. As described above, by viewing the result of forming the stepped portion 11 using a 3D composite image and referring to this processing information, the processing status of the stepped portion 11 can be viewed in association with the processing information. This allows, for example, retroactive analysis of the cause of a processing defect.

[0042] The control means 100 can prompt for maintenance related to the cutting blade 81. For example, the maintenance includes the timing for cutting blade dressing, the timing for cutting blade replacement, and adjustment of the Z-axis and Y-axis positions of the cutting blade, as shown in display mode M-7 in Fig. 12. Note that, for convenience of explanation, display mode M-7 shown in Fig. 12 simultaneously displays messages prompting for cutting blade dressing, informing of the timing for cutting blade replacement, adjusting the Z-axis of the cutting blade, and adjusting the Y-axis of the cutting blade, but in reality, only the necessary information is selected and displayed. The displayed message can be determined, for example, based on the measured cutting depth and width of the step portion 11 formed by the chamfering process. If the cutting blade 81 is clogged, the message "Please dress the cutting blade" is displayed. If the cutting blade 81 is worn, the message "Please replace the cutting blade" is displayed. Furthermore, if only the deviation of the cutting blade 81 in the Z-axis direction is detected, the message "Please adjust the Z-axis of the cutting blade" is displayed. If the deviation of the cutting blade 81 in the Y-axis direction is detected, the message "Please adjust the Y-axis of the cutting blade" is displayed. Various display methods can be selected. The above-mentioned display messages can be displayed independently on the display unit 24 or, for example, in conjunction with the display of the display modes M-1 to M-5. Furthermore, the maintenance-related messages can be displayed using animation, such as horizontally flowing or flashing, or by changing the shape or color of the characters.

[0043] The control means 100 can continuously display 3D composite images of multiple wafers on the display means 24, as in the display mode M-8 shown in FIG. 13. In the illustrated embodiment, measurement results A-1 to A-6 for six wafers 10 are continuously displayed. However, the present invention is not limited to this number, and other numbers may be displayed. Furthermore, if there are measurement results for, for example, 30 wafers, other wafers can be displayed by moving the displayed page. In this case, an animation display in which the pages move along with the wafers on the display screen 24 can be created. Then, by selecting a specific wafer (e.g., A-1) from the display screen 24, the operator can select and display the display mode he or she wants to view for wafer A-1 via the menu screen for selecting the above-mentioned display modes M-1 to M-6 to display detailed information related to the selected wafer A-1. In this way, measurement results for multiple wafers can be continuously viewed.

[0044] Furthermore, in the above-mentioned display mode M-8, by utilizing the function of displaying a three-dimensional composite image of multiple wafers, a three-dimensional composite image created based on the measurement results is displayed, and the measurement results are fed back to the chamfering process, and multiple assumed processing results, assuming that the chamfering process is performed by appropriately adjusting the processing conditions of the chamfering process, are generated as three-dimensional composite images, and may be displayed continuously together with the three-dimensional composite image created based on the measurement results. In this way, the effect of performing chamfering by feeding back the measurement results can be examined in advance.

[0045] Furthermore, the measurement results of the step portion 11 after chamfering are fed back to adjust the processing conditions for performing the chamfering, and the chamfering is actually performed on the wafer 10. Then, the step portion 11 of the wafer 10 on which the chamfering has been performed is measured to generate a 3D composite image. At the same time, a 3D composite image of the assumed processing results of the chamfering that would have been performed had the measurement results of the step portion 11 after the chamfering not been fed back is generated. The 3D composite image of the wafer 10 that has actually been chamfered after the feedback may be continuously displayed, along with the assumed processing results of the chamfering that would have been performed had the measurement results not been fed back. This makes it possible to confirm which parameters affected the shape of the step portion 11 formed on the wafer 10 and how they affected the shape of the step portion 11 formed on the wafer 10 as a result of adjusting the processing conditions by feeding back the measurement results.

[0046] The control means 100 can also appropriately superimpose multiple 3D composite images displayed in the above-described display mode M-8. For example, by superimposing two 3D composite images, one of which is semi-transparent, the change in the step portion 11 of the wafer 10 resulting from the chamfering can be intuitively viewed. Furthermore, by superimposing a 3D composite image generated based on the actually processed wafer 10 with a 3D composite image generated based on the assumed processing results assuming that the processing conditions are adjusted based on feedback of the measurement results of the step portion 11, the effect of feedback on the processing conditions based on the measurement results can be intuitively confirmed.

[0047] According to the processing apparatus 1 of the above-described embodiment, it is possible to intuitively view and easily check the state of the step portion 11 formed by the chamfering process, and it is possible to perform chamfering process in which the chamfered portion 15 is removed with such high precision that the thickness slightly exceeds the finished thickness obtained by grinding the back surface 10b of the wafer 10. [Explanation of symbols]

[0048] 1: Processing equipment 2: Housing 3: Carrying in / out means 4: Cassette 5: Temporary table 6: Means of transport 7: Chuck table 7a: Holding surface 8: Cutting means 81: Cutting blade 82: Rotation axis 83: 10: Wafer 10a: surface 10b: Back side 11: Step 12: Device 14: Planned division line 15: Chamfered part 16: Device area 17: Surplus outer area 19: Notch 20: Height measurement means 21: Camera 22: Cleaning equipment 23: Cleaning and carrying out means 24:Display means 100: Control means 110: Cutting depth setting section 120: Width setting section 130: Surface coordinate memory unit 140: Chamfering operation part 150: Depth memory section 160: Width memory section 170: 3D image generation unit 180: Attention Information Recording Department 190: Processing information recording unit

Claims

1. A wafer processing apparatus having a device area in which a plurality of devices are partitioned by planned division lines and an outer peripheral excess area having a chamfered portion surrounding the device area, the apparatus comprising: the wafer chuck table is provided with a holding surface defined by X and Y axes for suction-holding the wafer and is rotatable; cutting means having a rotation axis in the Y-axis direction for supporting a cutting blade for cutting the chamfered portion of the wafer held by suction on the chuck table to a thickness corresponding to the finished thickness of the wafer and forming a step portion; Z-axis feed means for feeding the cutting means in the Z-axis direction perpendicular to the holding surface; height measurement means for measuring the height of the top surface of the wafer held by suction on the chuck table; a camera for measuring the radial width of the step portion; control means; and display means; The control means a cutting depth setting unit that sets a cutting depth in the Z-axis direction of a chamfered portion to be cut from the front surface of the wafer held by suction on the chuck table; a width setting unit that sets the radial width of the chamfered portion to be cut; a surface coordinate storage unit that operates the height measurement means to measure and store the Z-axis coordinate of the surface of the wafer; a chamfering operation unit that performs processing to cut a chamfered portion based on the cutting depth set by the cutting depth setting unit, the width set by the width setting unit, and the Z-axis coordinate stored in the surface coordinate storage unit; a depth storage unit that, after the cutting of the chamfered portion by the chamfering operation unit is completed, positions the height measurement means on the outer periphery of the wafer corresponding to an angle from 0 degree to one revolution while rotating the chuck table, measures the depth of the step portion for each angle, and stores the depth of the step portion for each angle; a width storage unit that positions the camera on the outer periphery of the wafer, measures the radial width of the step portion for each angle, and stores the measured values; and a three-dimensional image generation unit that combines the measurement values stored in the depth storage unit and the width storage unit for each angle, generates a three-dimensional composite image, and displays the image on the display unit. A processing device comprising:

2. 2. The processing apparatus according to claim 1, wherein the control means displays the three-dimensional composite image on the display means while rotating the image.

3. 2. The processing apparatus according to claim 1, wherein the control means displays the three-dimensional composite image on the display means in an enlarged form.

4. 2. The processing device according to claim 1, wherein the control means includes an attention information recording section for recording attention information when a noteworthy portion is found based on the three-dimensional composite image.

5. 2. The processing device according to claim 1, wherein the control means displays the difference between the measurement values stored in the depth memory unit and the width memory unit in different colors, based on the cutting depth set in the cutting depth setting unit and the width set in the width setting unit.

6. 2. The processing apparatus according to claim 1, wherein the control means displays lines for slicing the three-dimensional composite image, and displays cross-sectional views and measurement values corresponding to the slicing lines.

7. 2. The processing device according to claim 1, wherein the control means comprises a processing time information recording section for recording processing time information of the cutting means when the chamfering operation section for cutting the chamfered portion is executed.

8. 2. The processing device according to claim 1, wherein the control means prompts maintenance of the cutting blade.

9. 2. The processing apparatus according to claim 1, wherein said control means continuously displays a three-dimensional composite image of a plurality of wafers on said display means.

Images