Wafer processing system and wafer processing method

Abstract

To provide a wafer processing system and a wafer processing method that appropriately processes blades on a laser-machined groove.SOLUTION: A wafer processing system includes: a control device 38 that acquires positional deviation information indicating positional deviation of a groove C relative to a planned dividing line L simultaneously with processing of the groove C by laser light along the planned dividing line L on a wafer W; a database server 60 that stores the acquired positional deviation information in association with information unique to the wafer W; and a blade dicing device 50 that performs cutting of the wafer W along the groove C with a blade on the basis of the stored positional deviation information corresponding to the wafer W.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wafer processing system and a wafer processing method, and more particularly to a technique for dicing a wafer with a blade after grooving the wafer with a laser. [Background technology]

[0002] As semiconductor devices become more sophisticated, wafers with mechanically fragile films (such as low-k films or high-k films) on their surface are becoming more common. When these wafers are blade diced, the mechanical load applied during dicing can cause the film to break or peel off. If this peeling reaches the device, it can result in a defective chip, resulting in a decrease in yield. To prevent this decrease in yield, a process is commonly used in which fragile films on the blade dicing line are removed using laser processing, which places a small mechanical load on the device, before blade dicing (see Patent Document 1). In this process, dicing is performed using two machines: a laser processing machine in the lead-up and a blade dicing machine in the follow-up.

[0003] In recent years, processing lines have become narrower in order to reduce chip size and increase the number of chips that can be taken from a single wafer in response to the increasing performance of chips. As a result, the width of the processed grooves has become smaller in both laser processing and blade processing, and higher precision processing is required. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-064231 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above process, the blade dicing must process the center of the laser-machined groove. This is because if the blade edge does not enter the laser-machined groove, mechanical load will cause the film to peel off. In other words, the blade dicing in this process must recognize the chip pattern and the pre-machined laser-machined groove.

[0006] When the equipment corrects the processing position in the preceding laser processing process, the relative position of the chip and laser-processed groove from that processing line shifts to the correct position from the previous processing line. However, since this corrected position cannot be grasped in the subsequent blade dicing, the laser-processed groove and blade processing position shift relative to that line. To prevent this, it is necessary to recognize the laser-processed groove position on all processing lines during blade dicing, but this takes time and is not practical.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a wafer processing system and a wafer processing method that perform blade processing appropriately on laser-processed grooves. [Means for solving the problem]

[0008] One aspect of a wafer processing system for achieving the above-mentioned object is a wafer processing system comprising a laser processing device, a blade dicing device, and a memory unit. The laser processing device comprises: a first stage that holds a wafer having a planned dividing line formed on its surface; a laser irradiation unit that irradiates laser light onto the surface of the wafer; a grooving processing control unit that processes grooves in the wafer along the planned dividing line with the laser light by moving the first stage and the laser irradiation unit relatively; an acquisition unit that acquires positional deviation information indicating the positional deviation of the groove relative to the planned dividing line by capturing an image of the wafer surface with an imaging unit; and a memory control unit that associates the positional deviation information with information unique to the wafer and stores it in the memory unit. The blade dicing device processes a wafer having a groove formed by the laser processing device as an object to be processed. The blade dicing device comprises: a positional information acquisition unit that acquires positional deviation information corresponding to the wafer from the memory unit; a second stage that holds the wafer; a blade that cuts the wafer; and a cutting processing control unit that cuts the wafer along the groove with the blade by moving the second stage and the blade relatively based on the acquired positional deviation information.

[0009] According to this aspect, the laser-machined groove can be appropriately machined with a blade.

[0010] The imaging unit is preferably disposed downstream of the laser irradiation unit in the direction of relative movement of the first stage and the laser irradiation unit, so that the imaging unit can capture an image of the wafer surface immediately after the grooves are machined.

[0011] It is preferable that the laser irradiation unit has an objective lens that focuses the laser light, and the imaging unit images the surface of the wafer through the objective lens, whereby the focus of the laser irradiation unit and the imaging unit can be adjusted using a common objective lens, and the groove processing and imaging of the wafer surface can be performed using the common objective lens.

[0012] It is preferable that the laser irradiation unit and the imaging unit have their focuses adjustable independently of each other, so that groove processing and imaging of the wafer surface can be performed by the laser irradiation unit and the imaging unit, each with their focuses adjusted.

[0013] It is preferable that the acquisition unit acquires the positional deviation information simultaneously with the groove processing, thereby reducing the time required to acquire the positional deviation information.

[0014] One aspect of a wafer processing method for achieving the above-mentioned object is a wafer processing method comprising: a grooving processing control step of relatively moving a first stage that holds a wafer having planned dividing lines formed on its surface and a laser irradiation unit that irradiates the laser light onto the surface of the wafer to form grooves on the wafer along the planned dividing lines with laser light; an acquisition step of acquiring positional deviation information that indicates the positional deviation of the grooves relative to the planned dividing lines by imaging the surface of the wafer; a storage control step of linking the positional deviation information to information unique to the wafer and storing it in a storage unit; a positional information acquisition step of acquiring, from the storage unit, the positional deviation information linked to the information unique to the wafer having the grooves formed on it; and a cutting processing control step of relatively moving a second stage that holds the wafer having the grooves formed on its surface and a blade that cuts the wafer having the grooves formed on it, to cut the wafer having the grooves along the grooves with the blade.

[0015] According to this aspect, the laser-machined groove can be appropriately machined with a blade. [Effects of the Invention]

[0016] According to the present invention, it is possible to appropriately perform blade machining on the laser-machined groove. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is an overview of a wafer processing system. [Figure 2] FIG. 2 is a plan view of the wafer. [Figure 3] FIG. 3 is a schematic diagram of the laser processing device according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram of a blade dicing device. [Figure 5] FIG. 5 is a flowchart showing an example of a process of a wafer processing method. [Figure 6] FIG. 6 is a diagram showing an example of a barcode attached to a wafer. [Figure 7] FIG. 7 is a diagram illustrating an example of data stored in the database server. [Figure 8] FIG. 8 is a schematic diagram of a laser processing device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. In this embodiment, the X, Y, and Z directions are perpendicular to each other. The X and Y directions are horizontal directions, and the Z direction is vertical.

[0019] First Embodiment [Overall configuration of wafer processing system] 1 is a schematic diagram of a wafer processing system 10. The wafer processing system 10 includes a laser processing device 20, a blade dicing device 50, and a database server 60.

[0020] The laser processing apparatus 20 is an apparatus that performs laser processing on a workpiece having a laminated film including a metal film formed on its surface. Here, the laser processing apparatus 20 irradiates a wafer W (workpiece) with laser light, which is processing light, along the streets L, which are intended dividing lines, formed on its surface, to process grooves C, which are processed grooves (kerfs). The blade dicing apparatus 50 is an apparatus that cuts the workpiece with a blade. Here, the blade dicing apparatus 50 cuts the wafer W having the grooves C formed thereon.

[0021] The database server 60 corresponds to a memory unit in which positional deviation information, which will be described later, is stored, and is equipped with server functions and large-capacity storage. The laser processing apparatus 20 and the database server 60, and the blade dicing apparatus 50 and the database server 60 are each connected to each other so that they can communicate with each other via a network, such as a P2P (Peer to Peer) connection. The database server 60 may be provided in the laser processing apparatus 20 or the blade dicing apparatus 50.

[0022] [Overall configuration of laser processing device] FIG. 2 is a plan view of a wafer W. The wafer W is a laminated body in which a low-k film and a functional film that forms a circuit are laminated on the surface of a substrate such as silicon. The wafer W is divided into multiple regions by multiple streets L arranged in a grid pattern in directions that intersect with each other. In FIG. 2, streets parallel to the X direction are denoted as LX, and streets parallel to the Y direction are denoted as LY. Devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are formed on chips C, which are regions divided by the streets LX and LY.

[0023] Fig. 3 is a schematic diagram of a laser processing apparatus 20 according to the first embodiment. As shown in Fig. 3, the laser processing apparatus 20 includes a stage 22, a laser light source 24, a laser irradiation unit 26, a Z base 28 for the laser irradiation unit, a camera 30, a Z base 32 for the camera, a common base 34, a movement mechanism 36, and a control device 38.

[0024] Stage 22 (an example of a first stage) holds wafer W on its upper surface with the surface of wafer W facing upward in the Z direction. Stage 22 is equipped with a motor (not shown) and configured to be movable in the X and Y directions and rotated within the XY plane by a movement mechanism 36.

[0025] The laser light source 24 includes a laser oscillator (not shown) and generates laser light, which is processing light. The laser irradiation unit 26 irradiates the surface of the wafer W with the laser light. The laser irradiation unit 26 includes an irradiation optical system (not shown) including an objective lens 26A, and the laser light generated by the laser light source 24 is converged and emitted by the irradiation optical system. The Z base 28 for the laser irradiation unit holds the laser irradiation unit 26 with the objective lens 26A of the laser irradiation unit 26 facing downward in the Z direction.

[0026] The camera 30 (an example of an imaging unit) is equipped with an observation optical system (not shown) including a light source (not shown), an imaging element (not shown), and an objective lens 30A, and captures (observes) an image of the surface of the wafer W. The camera 30 is equipped with a light source (not shown) equivalent to a 250 W metal halide light source, and is capable of capturing an image with an exposure time of less than 1 μs. The objective lens 30A has a numerical aperture NA of 0.4 and a resolution of approximately 0.8 μm at a wavelength of 550 nm of observation light.

[0027] The camera Z base 32 holds the camera 30 with the objective lens 30A of the camera 30 facing downward in the Z direction. The common base 34 holds the laser irradiation unit Z base 28 and the camera Z base 32.

[0028] In this way, the laser irradiation unit 26 and the camera 30 are held so that their respective focuses can be adjusted. The common base 34 also holds the camera 30 downstream of the laser irradiation unit 26 in the X-direction relative movement between the common base 34 and the stage 22 during laser processing, which will be described later.

[0029] The control device 38 performs overall control of the laser processing device 20. The laser processing device 20 processes grooves along the streets LX and LY of the wafer W in accordance with the control of the control device 38.

[0030] That is, the control device 38 controls the laser light source 24 to generate laser light. The control device 38 also controls a motor (not shown) to move the Z base 28 for the laser irradiation unit in the Z direction so that the focal point of the objective lens 26A of the laser irradiation unit 26 is aligned with a desired position on the wafer W in the Z direction.

[0031] The control device 38 controls a motor (not shown) to move the camera Z base 32 in the Z direction so that the focal point of the objective lens 30A of the camera 30 is aligned with a desired position on the wafer W in the Z direction.

[0032] The control device 38 (an example of a grooving processing control unit) controls a motor (not shown) to move (scan) the common base 34 in the X direction relative to the stage 22, and uses laser light to remove the low-k film along the street LX of the wafer W to process grooves. In the example shown in FIG. 3, the stage 22 is scanned leftward in the X direction relative to the common base 34. When laser processing of one street LX is completed, the control device 38 controls a motor (not shown) to move the stage 22 in the Y direction relative to the common base 34, and then performs laser processing of the adjacent street LX in a similar manner.

[0033] In this embodiment, the stage 22 is configured to be movable in the X and Y directions, and the laser irradiation unit 26 is configured to be movable in the Z direction. However, it is only necessary that the stage 22 and the laser irradiation unit 26 are capable of moving relatively in the X, Y, and Z directions. For example, the stage 22 may be configured to be movable in the X direction, and the laser irradiation unit 26 may be configured to be movable in the Y and Z directions.

[0034] Furthermore, when laser processing of all the streets LX is completed, the control device 38 controls a motor (not shown) to rotate the stage 22 by 90°, thereby rotating the wafer W by 90°. Thereafter, as in the case of the streets LX, the stage 22 is scanned leftward in the X direction relative to the common base 34, and grooves C are processed along the streets LY of the wafer W with the laser light.

[0035] Furthermore, the control device 38 (an example of an acquisition unit) observes the streets LX and LY and the groove C when the groove C is processed with the laser light by capturing an image of the surface of the wafer W with the camera 30, and acquires positional deviation information indicating the positional deviation of the groove C with respect to the streets LX and LY. Furthermore, the control device 38 (an example of a storage control unit) stores the acquired positional deviation information in the database server 60, linking it to information specific to the wafer W on which the groove C is formed.

[0036] [Overall configuration of blade dicing device] The blade dicing apparatus 50 is an apparatus that processes a wafer W on which grooves C have been formed by the laser processing apparatus 20. Fig. 4 is a schematic diagram of the blade dicing apparatus 50. As shown in Fig. 4, the blade dicing apparatus 50 includes a stage 52, a blade 54, a moving mechanism 56, and a control apparatus 58.

[0037] Stage 52 (an example of a second stage) holds wafer W on its upper surface with the surface of wafer W facing upward in the Z direction. Stage 52 is equipped with a motor (not shown) and configured to be movable in the X direction and rotated in the XY plane (movement in the θZ direction) by a movement mechanism 56. Blade 54 is a disk-shaped member parallel to the XZ plane and equipped with an annular cutting blade (not shown) on its outer periphery. The center of blade 54 is supported by a spindle (not shown) parallel to the Y direction. The spindle is equipped with a motor (not shown) and configured to be movable in the Y and Z directions by the movement mechanism 56. Blade 54 is equipped with a motor (not shown) connected to the spindle and is supported to be rotatable in the XZ plane.

[0038] The control device 58 performs overall control of the blade dicing device 50. The blade dicing device 50 cuts the wafer W under the control of the control device 58.

[0039] That is, the control device 58 (an example of a position information acquisition unit) acquires positional deviation information corresponding to the wafer W to be processed from the database server 60. The control device 58 controls a motor (not shown) to rotate the blade 54. The control device 58 (an example of a cutting processing control unit) controls the motor (not shown) to move the stage 52 in the X direction while adjusting the processing position based on the acquired positional deviation information, and cuts the center of the groove along the street LX of the wafer W with the blade 54. When cutting the center of the groove along one street LX is completed, the control device 58 controls the motor (not shown) to move the blade 54 in the Y direction, and then similarly cuts the center of the groove along the adjacent street LX.

[0040] Furthermore, when cutting along all of the streets LX is completed, the control device 58 controls a motor (not shown) to rotate the stage 52 by 90°, thereby rotating the wafer W by 90°. Thereafter, as in the case of the grooves along the streets LX, the stage 52 is moved in the X direction while adjusting the processing position based on the acquired positional deviation information, and the blade 54 cuts the centers of the grooves along the streets LY of the wafer W.

[0041] In this embodiment, the stage 52 is configured to be movable in the X direction and the θZ direction, and the blade 54 is configured to be movable in the Y direction and the Z direction. However, it is sufficient if the stage 52 and the blade 54 are capable of moving relatively in the X direction, Y direction, Z direction, and the θZ direction. For example, the stage 52 may be configured to be movable in the X direction, Y direction, and the θZ direction, and the blade 54 may be configured to be movable in the Z direction.

[0042] [Wafer processing method] 5 is a flowchart showing an example of a process for a wafer processing method. Here, the positions of all streets L and grooves C on the wafer W are inspected in advance, and blade dicing is performed based on the inspection information. This inspection can be performed using a separate inspection device, but here, in the laser processing process using the preceding laser processing device 20, the amount of misalignment between the streets L and grooves C is determined simultaneously with laser processing, and information on the amount of misalignment of the grooves C relative to each street L is linked to the wafer W and passed to the subsequent blade dicing device 50. Based on this misalignment information, the blade dicing device 50 processes the centers of the grooves C simply by recognizing the chip pattern.

[0043] In step S1 (an example of a grooving control process, an example of an acquisition process), the laser processing device 20 performs grooving on the wafer W while simultaneously observing the position of the groove C relative to the street L and inspecting the amount of positional deviation of the groove C relative to the street L. If the laser processing device 20 determines that the amount of positional deviation between the street L and the groove C is large, it corrects the grooving position relative to the adjacent street L in the next scan.

[0044] In this way, the laser processing device 20 performs inspection during laser processing. Note that "simultaneously" here does not necessarily mean exactly the same timing, but means that inspection is performed in parallel during one scan.

[0045] Stopping the laser beam processing increases the processing time. For this reason, in this embodiment, a method is adopted in which the street L and groove C are imaged during laser processing (during the relative movement between the laser beam and the wafer W) and the amount of misalignment is inspected. This method is called a scan kerf check. In this scan kerf check, the wafer W is imaged during scanning, so a light source with a large amount of light and a processing device that performs continuous image processing are required so that the street L and groove C can be recognized even with a short exposure time.

[0046] Here, the scanning speed for grooving is 600 [mm / sec]. By using the camera 30, the deviation in the Y direction can be suppressed to about 3 [μm].

[0047] The inspection of the amount of positional deviation of the groove C may be performed for all streets L or for some of the streets L. If there is a street L on which the amount of positional deviation of the groove C has not been inspected, the amount of positional deviation of the groove C relative to that street L is generated by interpolation from the amount of positional deviation of the groove C relative to neighboring streets L.

[0048] In step S2 (an example of a storage control process), in order to transfer the positional deviation information from the laser processing device 20 to the blade dicing device 50, the positional deviation information recorded in step S1 is linked to the wafer W on which the groove C is formed and stored in the database server 60.

[0049] The wafer W on which the groove C is formed is linked to the misalignment information acquired from the wafer W using a wafer ID (an example of information unique to the wafer) engraved on the wafer W or a barcode (an example of information unique to the wafer) affixed to the frame of the wafer W as a key. FIG. 6 is a diagram showing an example of a barcode attached to a wafer W. FIG. 6 shows a wafer W with a wafer ID of #1 and a wafer W with a wafer ID of #2. As shown in FIG. 6, each wafer W has a unique barcode B attached to its backside.

[0050] The laser processing device 20 acquires the wafer ID of the wafer W on which the groove C is formed, and stores the wafer ID and the misalignment information in the database server 60 in association with each other.

[0051] 7 is a diagram showing an example of positional deviation information stored in the database server 60. In the example shown in Fig. 7, the deviation amounts of the grooves C with respect to the streets L having street numbers 1, 2, 3, 4, ... of the wafer W having a wafer ID of #1 are -0.5 µm, +1.0 µm, +0.1 µm, +0.1 µm, ..., respectively. Also, the deviation amounts of the grooves C with respect to the streets L having street numbers 1, 2, ... of the wafer W having a wafer ID of #2 are -2.0 µm, -3.0 µm, ..., respectively.

[0052] As described above, the amount of deviation of the groove C from the street L can be linked to the wafer ID of the wafer W on which the groove C is formed and stored in the database server 60. Here, an example has been described in which the wafer ID is managed by the barcode B, but the information specific to the wafer may also be managed in order, such as "the order in which the wafer was processed."

[0053] In step S3 (an example of a position information acquisition step), the blade dicing device 50 acquires the wafer ID of the wafer W to be processed, and acquires from the database server 60 the positional deviation information of the wafer ID.

[0054] In step S4 (an example of a cutting process control step), the blade dicing device 50 adjusts the cutting position based on the acquired positional deviation information with respect to the street L to be cut on the wafer W. As a result, the blade dicing device 50 cuts the center of the groove C on the wafer W without inspecting the position of the groove C on the wafer W to be processed.

[0055] Here, the street L recognized by the laser processing device 20 and the street L recognized by the blade dicing device 50 are linked together by pattern matching using unique patterns such as chip edges and notches on the wafer W.

[0056] For example, when initially registering information about the wafer W in the laser processing device 20 and the blade dicing device 50, by registering information indicating how many μm away the first street L is from the unique pattern, it is possible to align the first street L between the laser processing device 20 and the blade dicing device 50. In the case of the wafer W shown in FIG. 2, it has a unique pattern P with no similar patterns in nearby areas, and by specifying the distance from the pattern P, the first street L can be recognized in common by the laser processing device 20 and the blade dicing device 50. As the unique pattern, a feature of the outer shape of the wafer W, such as a notch or an orientation flat, may be used.

[0057] Alternatively, the distance from the center of the wafer W to the first street L may be set in advance, and the center of the wafer W may be determined using the outer shape measurement function, thereby aligning the position of the first street L.

[0058] As described above, according to the wafer processing method of this embodiment, the position of the groove C measured by the laser processing device 20 can be transferred to the blade dicing device 50, and the blade dicing device 50 can perform cutting without inspecting the position of the groove C again. As a result, high quality, high precision, and short processing time are possible throughout the entire process.

[0059] In theory, it is also possible to observe the groove C before cutting using the blade dicing device 50 to obtain positional deviation information. However, the blade dicing device 50 is subject to many disturbances due to the handling of cutting water for cooling the blade, making it an undesirable environment for photographing. Therefore, the laser processing device 20 is preferable to the blade dicing device 50 because it allows the position of the groove C to be observed in a stable environment.

[0060] In this embodiment, the objective lens 26A of the laser irradiation unit 26 and the objective lens 30A of the camera 30 are independent of each other. Furthermore, the laser irradiation unit Z base 28 and the camera Z base 32 are configured to allow the laser irradiation unit 26 and the camera 30 to be moved independently in the Z direction. Therefore, there are no limitations on the wavelength of the processing light, the focal depth, the pupil diameter, the light emission during processing, the focus position during processing, and the like. Furthermore, even when an optical system with a shallow depth of field is used, the laser irradiation unit 26 and the camera 30 can be independently focused, allowing both to be focused at an appropriate height, and processing and imaging to be performed under optimal conditions.

[0061] On the other hand, since the irradiation position of the laser irradiation unit 26 and the imaging position of the camera 30 are separated, the scanning distance in the X direction increases by the distance between them, which increases the processing time. For this reason, inspection may be performed not for all streets L but at any timing, such as at intervals between any streets L or before or after correction by laser processing. The timing of inspection may be configured to be set by the user. Furthermore, the deviation amount of grooves C that are not inspected may be interpolated using a linear or any higher-order curve, or may not be interpolated.

[0062] Furthermore, the laser irradiation unit 26 and the camera 30 may share a common Z base, and the laser irradiation unit 26 and the camera 30 may be configured to be movable simultaneously in the Z direction.

[0063] Furthermore, a portable storage medium such as a USB (Universal Serial Bus) memory may be used instead of the database server 60. In this case, the laser processing device 20 and the blade dicing device 50 are configured to be able to access data from the portable storage medium.

[0064] <Second embodiment> 8 is a schematic diagram of a laser processing apparatus 70 according to a second embodiment. Parts common to those in the laser processing apparatus 20 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. As shown in FIG. 8, the laser processing apparatus 20 includes a laser irradiation unit 72, a dichroic mirror 74, and a common Z base 76.

[0065] The laser irradiation unit 72 includes an objective lens 72A. The dichroic mirror 74 is disposed in the optical path of the laser light from the laser light source 24 to the objective lens 72A. The common Z base 76 holds the laser irradiation unit 72 with the objective lens 72A of the laser irradiation unit 72 facing downward in the Z direction.

[0066] The laser light emitted from the laser light source 24 passes through the dichroic mirror 74 and enters the objective lens 72A of the laser irradiation unit 72. The objective lens 72A focuses the incident laser light onto the wafer W at its focal position.

[0067] The common Z base 76 also holds the camera 30. The camera 30 includes an observation light source 30B, a half mirror 30C, and an image sensor 30D. Observation light emitted from the observation light source 30B is reflected by the half mirror 30C and the dichroic mirror 74 and enters the objective lens 72A. The objective lens 72A directs the incident observation light to the focal position of the wafer W.

[0068] Of the observation light incident on the wafer W, a portion of the light reflected by the wafer W enters the objective lens 72A as subject light. The subject light incident on the objective lens 72A is reflected by the dichroic mirror 74, enters the camera 30, passes through the half mirror 30C, and enters the image sensor 30D. The image sensor 30D receives the incident subject light and captures an image of the subject.

[0069] In this way, the camera 30 captures an image of the surface of the wafer W on which the groove C is formed through the objective lens 72A of the laser irradiation unit 72. The use of a single objective lens 72A allows the entire optical system to be made compact. Furthermore, the common Z base 76 allows the focus of the processing light and the focus of the observation light to be adjusted simultaneously. Furthermore, the scanning distance during processing can be shortened. Note that an optical system may be added to allow the focus of the processing light and the focus of the observation light to be adjusted independently of each other.

[0070] The single objective lens 72A has lower contrast and resolution than the dedicated objective lens 30A (see FIG. 3) of the camera 30. Specifically, the objective lens 72A has a numerical aperture NA of about 0.15 and a resolution of about 1.7 μm when the wavelength of the observation light is 430 nm.

[0071] <Other> With the laser processing device 20 and the laser processing device 70, it is also possible to use the deviation amount of the groove C as feedback, such as by adjusting the Y-direction position (active Y) or adjusting the angle (active θ) during processing in real time in a direction that cancels out the deviation amount of the groove C shown in Figure 7.

[0072] If the amount of misalignment at a certain Y coordinate and a certain X-axis speed is reproducible, then once the amount of misalignment is observed under those conditions and stored, there is no need for real-time inspection when machining under the same conditions thereafter. However, if there are disturbances such as changes in water temperature or air temperature, it is effective to measure and correct in real time. The advantages of not inspecting in real time include the ability to sample frequently, since the inspection interval does not affect the machining speed, and the fact that processing time does not affect the machining speed, leaving more room for processing, so problems do not occur even with equipment with low processing capacity.

[0073] Furthermore, the amount of debris generated may be observed with the camera 30, and the soundness of the nozzle may be inspected based on the amount of debris generated.

[0074] If the grooves C for all streets L of the wafer W can be observed without any gaps, then a visual inspection of the grooves C of all chips can be performed within the laser processing device 20 (70), making it possible to identify defective chips where processing defects or omissions have occurred in advance. Also, by measuring the change in distortion, it is possible to predict failures and determine the timing of maintenance of the laser processing device 20 (70).

[0075] The technical scope of the present invention is not limited to the scope described in the above embodiments. The configurations and the like in each embodiment can be appropriately combined with each other within the scope that does not deviate from the spirit of the present invention. [Explanation of symbols]

[0076] 10...Wafer processing system 20...Laser processing equipment 22...Stage 24...Laser light source 26...Laser irradiation unit 26A...Objective lens 28...Z base for laser irradiation unit 30...Camera 30A...Objective lens 32...Z base for camera 34...Common base 36...Movement mechanism 38...Control device 50...Blade dicing device 52...Stage 54...Blade 56…Movement mechanism 58...Control device 60...Database server 70...Laser processing equipment 72...Laser irradiation unit 72A...Objective lens 74...Dichroic mirror 76...Common Z base B...Barcode C…Groove L, LX, LY...Street P...Pattern W...wafer S1 to S4: Each step in the wafer processing method

Claims

1. an information acquiring unit that acquires, for a wafer on which grooves are machined by a laser beam along planned dividing lines, positional deviation information indicating positional deviation of the grooves with respect to the planned dividing lines simultaneously with machining of the grooves; a storage unit that stores the acquired positional deviation information in association with information unique to the wafer; a processing unit that cuts the wafer along the groove with a blade based on the stored positional deviation information corresponding to the wafer; Equipped with Wafer processing system.

2. The unique information of the wafer is a wafer ID or a barcode attached to the wafer. The wafer processing system according to claim 1 .

3. an information acquiring step of acquiring, simultaneously with processing of the grooves on a wafer in which grooves are processed by a laser beam along the planned dividing lines, positional deviation information indicating positional deviation of the grooves with respect to the planned dividing lines; a storage step of storing the acquired misalignment information in association with information unique to the wafer; a processing step of cutting the wafer along the groove with a blade based on the stored positional deviation information corresponding to the wafer; Equipped with Wafer processing method.

4. The unique information of the wafer is a wafer ID or a barcode attached to the wafer. The wafer processing method according to claim 3 .

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