JP7799463B2 - processing equipment - Google Patents

Description

The present invention relates to a processing apparatus that processes a wafer having a plurality of devices formed on its surface, partitioned by planned division lines.

Wafer surfaces are divided by planned division lines to form multiple devices such as ICs and LSIs. These are then separated into individual device chips using a cutting device equipped with a rotatable cutting blade, a laser processing device equipped with a laser beam irradiation means, or the like. These chips are then used in electrical equipment such as mobile phones and personal computers.

The cutting device includes a chuck table having a holding surface defined by X and Y axes that holds a wafer, imaging means for imaging the wafer held on the chuck table, display means for displaying the image captured by the imaging means, processing means for processing the wafer held on the chuck table, X-axis movement means and Y-axis movement means for moving the chuck table in the X-axis and Y-axis directions relative to the imaging means and processing means, and control means. It is capable of cutting the wafer along its planned dividing lines with high precision and dividing it into individual device chips (see, for example, Patent Document 1).

The applicant has also proposed a technology for automatically finding feature points from a device imaged by an imaging device or from a circuit formed on the planned division line in order to align the cutting blade with the planned division line, and then performing pattern matching using the feature points as a key pattern to detect the position of the planned division line based on the position of the key pattern (see, for example, Patent Document 2).

Japanese Patent Application Publication No. 02-290040 Japanese Patent Application Publication No. 07-321181

According to the technology disclosed in the aforementioned Patent Document 2, feature points are automatically selected as key patterns based on the calculations of a control program that processes captured images, and pattern matching is performed. However, processing equipment is installed in a variety of environments, and the selection environment changes depending on factors such as the lighting conditions and rotational misalignment when holding the wafer. Furthermore, the patterns that appear on devices as candidate feature points vary widely depending on the type of wafer or device, so the optimal feature points are not always selected. In many cases, a skilled worker can more appropriately select feature points as key patterns. On the other hand, it is not easy for an inexperienced worker to visually select feature points as key patterns, and it takes an inexperienced worker longer to appropriately select a characteristic pattern than a skilled worker.

The present invention was developed in light of the above facts, and its main technical objective is to provide a processing device equipped with an assist mechanism that allows even inexperienced and unskilled workers to select key patterns at a level comparable to that of experienced workers.

In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a processing apparatus for processing a wafer having a surface on which a plurality of devices are formed and partitioned by planned division lines, the processing apparatus comprising: a chuck table having a holding surface defined by X- and Y-axes for holding the wafer; imaging means for imaging the wafer held on the chuck table; display means for displaying the image captured by the imaging means; processing means for processing the wafer held on the chuck table; X-axis moving means and Y-axis moving means for moving the chuck table in the X-axis and Y-axis directions relative to the imaging means and the processing means; and control means, the control means being configured to image the wafer held on the chuck table with the imaging means and display the image on the display means, and including an assist mechanism for displaying the suitability of a key pattern in an area from which a key pattern is to be selected to assist in the selection of a key pattern , and the assist mechanism being configured to calculate the similarity between an arbitrary area and other areas when the arbitrary area is selected as a key pattern. The processing device calculates a degree of similarity for each of the areas to which a degree of similarity has been assigned, and calculates a degree of suitability for the area to be a key pattern so that the lower the degree of similarity, the higher the degree of suitability, and displays the degree of suitability for the area on the display means.The processing device rotates the chuck table within an angle error range between the planned division line and the X-axis direction, calculates a change in similarity for each of the areas to which a degree of similarity has been assigned, and corrects the degree of suitability by multiplying the degree of similarity by a coefficient based on the lowest degree of similarity, or changes the brightness of the area imaged by the imaging means, and calculates a change in similarity for each of the areas to which a degree of similarity has been assigned, and corrects the degree of suitability by multiplying the degree of similarity by a coefficient based on the lowest degree of similarity, or multiplies the degree of similarity by 1 if the imaging area imaged by the imaging means covers the entire area related to one device and has been assigned a degree of suitability for the key pattern, or if the imaging area does not cover the entire area, multiplies the degree of similarity by 1 if the imaging area does not cover the entire area .

The processing device may either change the brightness of the area imaged by the imaging means, calculate the change in similarity for each area to which a suitability has been assigned, and correct the suitability by multiplying the suitability by a coefficient based on the lowest similarity, or, if the imaging area imaged by the imaging means covers the entire area related to one device and has been assigned a suitability for a key pattern, multiply the suitability by 1, or, if the imaging area does not cover the entire area, multiply the suitability by the ratio of the imaging area to the entire area to correct the suitability.In either case, the processing device may change the brightness of the area imaged by the imaging means, calculate the change in similarity for each area to which a suitability has been assigned, and correct the suitability by multiplying the suitability by a coefficient based on the lowest similarity.

When the imaging area imaged by the imaging means covers the entire area related to one device and assigns a suitability to the key pattern, the processing device multiplies the suitability by 1, and when the imaging area does not cover the entire area, the processing device multiplies the suitability by the ratio of the imaging area to the entire area to correct the suitability.In this case, the processing device may change the brightness of the area imaged by the imaging means, calculate the change in similarity for each area to which a suitability has been assigned, and multiply the suitability by a coefficient based on the lowest similarity. The processing device may also vary the brightness of the area imaged by the imaging means, calculate the change in similarity for each area to which a suitability has been assigned, and modify the suitability by multiplying the suitability by a coefficient based on the lowest similarity, and if the imaging area imaged by the imaging means covers the entire area related to one device and has been assigned a suitability for a key pattern, multiply the suitability by 1, and if the imaging area does not cover the entire area, multiply the suitability by the ratio of the imaging area to the entire area to modify the suitability, and further vary the brightness of the area imaged by the imaging means, calculate the change in similarity for each area to which a suitability has been assigned, and modify the suitability by multiplying the suitability by a coefficient based on the lowest similarity.

The processing apparatus of the present invention processes a wafer having a surface on which a plurality of devices are formed and partitioned by planned division lines, and includes a chuck table having a holding surface defined by X and Y axes for holding the wafer, imaging means for imaging the wafer held on the chuck table, display means for displaying the image captured by the imaging means, processing means for processing the wafer held on the chuck table, X-axis moving means and Y-axis moving means for moving the chuck table in the X-axis direction and Y-axis direction relative to the imaging means and the processing means, and control means, wherein the control means images the wafer held on the chuck table with the imaging means and displays the image on the display means, and is equipped with an assist mechanism for displaying suitability as a key pattern in an area for selecting a key pattern to assist in selection of a key pattern, and the assist mechanism calculates similarity between an arbitrary area as a key pattern and other areas, and performs calculations such that the lower the similarity, the higher the suitability as a key pattern, and the display means In the processing device, which assigns and displays suitability to the arbitrary region, the chuck table is rotated within an angle error range between the planned division line and the X-axis direction, and a change in similarity is calculated for each of the regions to which the suitability has been assigned, and the suitability is corrected by multiplying the suitability by a coefficient based on the lowest similarity, or the brightness of the region imaged by the imaging means is changed, and a change in similarity is calculated for each of the regions to which the suitability has been assigned, and the suitability is corrected by multiplying the suitability by a coefficient based on the lowest similarity, or If the imaging area imaged by the imaging means covers the entire area related to one device and assigns a suitability to the key pattern, the suitability is multiplied by 1, and if the imaging area does not cover the entire area, the suitability is corrected by multiplying it by the ratio of the imaging area to the entire area.Therefore , even an operator with little experience and skill can be assisted in selecting a key pattern when performing alignment, and can select a key pattern with efficiency comparable to that of an experienced and highly skilled operator.

1 is an overall perspective view of a cutting device according to an embodiment of the present invention; FIG. 10 is a perspective view showing an embodiment in which an image of a wafer is captured by an imaging means and displayed on a display means. FIG. 2 is a conceptual diagram of an area displayed on a display unit. FIG. 1A is a conceptual diagram showing an enlarged view of an arbitrary region, and FIG. 1B is a conceptual diagram showing a state in which the region shown in FIG. 1A is rotated. (a) Conceptual diagram of an arbitrary area imaged at average illuminance, (b) Conceptual diagram of an area imaged at a brighter illuminance than the area shown in (a), and (c) Conceptual diagram of an area imaged at a darker illuminance than the area shown in (a).

An embodiment of a processing device constructed based on the present invention will be described in detail below with reference to the accompanying drawings.

Figure 1 shows an overall perspective view of a cutting device 1, which is one embodiment of the processing device of the present invention. The workpiece processed by the cutting device 1 is a semiconductor wafer 10 (see also Figure 2) on whose surface 10a a plurality of devices 12 are formed and partitioned by planned division lines 14, and is held in an annular frame F via protective tape T.

The cutting device 1 comprises a substantially rectangular parallelepiped housing 2, a cassette 4 placed on a cassette table 4a that can be raised and lowered, a transfer means 3 that transfers wafers 10 held in frames F from the cassette 4 to a temporary storage table 5, a transport means 6 with a swivel arm that transports the wafers 10 transferred to the temporary storage table 5 to a chuck table 7 having a holding surface 7a, a cutting means 8 that is provided as a processing means for processing the wafers 10 held on the chuck table 7 and is equipped with a cutting blade, an imaging means 20 that images the wafers 10 held on the chuck table 7 and performs alignment to detect the planned division lines 14 to be cut by the cutting blade of the cutting means 8, a cleaning and transport means 9a that transports the wafers 10 from the transfer position where the chuck table 7 is positioned in FIG. 1 to a cleaning device 9 (details omitted), a control means 30, and a display means M.

The holding surface 7a of the chuck table 7 is a substantially horizontal XY plane defined by the X-axis direction and the Y-axis direction perpendicular to the X-axis direction. The holding surface 7a is made of a breathable material, and is connected to a suction source (not shown). Activating the suction source generates negative pressure on the holding surface 7a. Inside the housing 2, there are provided an X-axis moving means for moving the chuck table 7 in the X-axis direction relative to the imaging means 20 and the cutting means 8, and a Y-axis moving means for moving the chuck table 7 in the Y-axis direction (both not shown).

The control means 30 is connected to at least the imaging means 20 and the display means M. The control means 30 of this embodiment is configured as 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, etc., a readable/writable random access memory (RAM) for temporarily storing detected values, calculation results, etc., an input interface, and an output interface (details not shown). For convenience of explanation, in FIG. 1, the control means 30 is shown outside the housing 2, but in reality it is disposed inside the housing 2. In addition to the imaging means 20 and display means M, the control means 30 of this embodiment is also connected to the cutting means 8, X-axis movement means and Y-axis movement means (not shown), etc., and controls each operating unit of the cutting device 1.

The control means 30 is equipped with an assist mechanism that images the wafer W held on the chuck table 7, displays the captured image on the display means M, and displays the suitability of the key pattern in the key pattern selection area to assist in the selection of the key pattern (this assist mechanism will be described in detail later).

The cutting device 1 of this embodiment has roughly the configuration described above, and the functions and operations of the assist mechanism of this embodiment will be explained below.

When operating the assist mechanism in the cutting device 1 of this embodiment, first, the wafer 10 stored in the cassette 4 is transported and placed on the chuck table 7 by the loading/unloading means 3, the transport means 6, etc., and is held by suction. Next, the X-axis movement means and Y-axis movement means described above are operated to position the wafer 10 held on the chuck table 7 directly below the imaging means 20, as shown in Figure 2. A portion of the wafer 10 is imaged by the imaging means 20, and the image is sent to the control means 30, and the image is displayed on the display means M.

The control program constituting the assist mechanism stored in the control unit 30 performs the following computational processing on the image data captured by the imaging unit 20. More specifically, first, in the image area captured by the imaging unit 20 and displayed on the display unit M, multiple areas containing circuit components or pattern shapes formed by printing or the like on the device 12 and the planned division line 14 are captured. These areas are, for example, areas k1 to k10, as shown in FIG. 3. As shown in FIG. 3, these areas may be areas where individual patterns are captured individually (e.g., areas k1 to k9), or may be a composite area k10 (area k2 + area k6 + area k7 + area k8) where multiple individually captured areas are combined. Note that the pattern on the device 12 shown in FIG. 3 is simplified for ease of explanation and may differ from the pattern observed on the actual device 12. Also, for convenience of explanation, Figure 3 shows areas k1 to k10 relating to only some patterns, but in reality, the assist mechanism of the control means 30 captures all patterns as areas that will become key patterns and is the subject of calculation. Also, the display means M in Figure 3 displays the entire area 100 relating to one device 12. This entire area 100 is an area that includes the device 12 and the planned division line 14 adjacent to the device 12, and is an area necessary for properly selecting a characteristic key pattern relating to the device 12.

As described above, once the entire area 100 captured by the imaging means 20 is displayed on the display means M, the suitability of the area as a characteristic key pattern suitable for use in alignment is calculated. There are various possible methods for calculating the suitability, and although there are no particular limitations, it may be calculated, for example, as follows:

3, a plurality of regions k1 to k10 are captured in the entire region 100 displayed on the display means M. If region k1 is set as the key pattern, the similarity with the other regions is calculated based on, for example, the following formula (1), and an aptitude X1 is calculated based on the maximum value of the calculated similarities.
Suitability X1 = maximum similarity - maximum similarity with other regions (1)

The above similarity is an evaluation of the degree of similarity between an arbitrary region and other regions through pattern matching, and is calculated, for example, between 0 and 100. If there is another region composed of the same pattern as the arbitrary region, they will match perfectly through pattern matching, and the similarity will be calculated as the maximum value of 100. The "maximum similarity" in the above formula (1) is a fixed value, which is 100 in this embodiment. Furthermore, the "maximum similarity with other regions" in the above formula (1) is, for example, the largest similarity among the multiple similarities calculated when multiple pattern matches are performed between the arbitrary region and regions other than the arbitrary region captured in the entire region 100 displayed on the display means M. That is, according to the above formula (1), the similarity between an arbitrary region and a plurality of other regions is calculated, and the similarity obtained when pattern matching is performed with the most similar region is subtracted from the maximum similarity value (=100). It can be understood that the higher the similarity with other regions, the smaller the suitability value X1, and the lower the similarity with other regions, i.e., the more distinctive the arbitrary region, the larger the suitability value X1, and the higher the suitability as a key pattern to be used in alignment. Note that, in the entire region 100 imaged on the display means M shown in Figure 3, for example, the suitability of region k1 = 40, the suitability of region k2 = 60, the suitability of region k3 = 40, the suitability of region k4 = 20, the suitability of region k5 = 50, the suitability of region k6 = 30, the suitability of region k7 = 15, the suitability of region k8 = 10, and the suitability of region k10 = 80 are displayed in the upper right corner of each region. For ease of explanation, the suitability of all areas corresponding to each pattern on the device 12 is not displayed, but it is also possible to display the suitability X1 for all areas.

The assistance mechanism of this embodiment, as described above, displays the aptitude X1 calculated based on the above formula (1) for each of the multiple regions k1-k9 and k10 on the device 12 in the entire key pattern selection region 100 displayed on the display means M shown in FIG. 3. The aptitude X1 becomes a higher value the more distinctive the pattern contained in each region is determined to be by the control program. In the embodiment shown in FIG. 3, the composite region k10 has the highest aptitude X1 (=80). By referencing this aptitude X1 value on the display means M, even less experienced and skilled workers can be assisted in selecting key patterns when performing alignment, allowing them to select key patterns with efficiency comparable to that of experienced and highly skilled workers. Furthermore, even highly skilled workers can efficiently exclude regions with low aptitude when selecting key patterns, thereby enabling them to select key patterns efficiently. As shown in Figure 3, when the suitability X1 is displayed on the display means M together with the entire area 100 related to the device 12, it is also possible to change the color of the suitability value in association with the suitability value. For example, if the suitability is 70 or higher, it is considered highly recommended and is displayed in blue, and as the score decreases, the color may change to green, yellow, or red.

The suitability X1 calculated based on the above formula (1) can be modified based on the technical concepts described below.

As described above, when the wafer 10 is held on the frame F via the protective tape T, it is held at a predetermined angle relative to the frame F. However, the wafer 10 held on the frame F has an angular error θ in the rotational direction, for example, the angular error θ = ±3°. If the wafer 10 is misaligned in the rotational direction relative to the frame F within this range of angular error θ, the suitability of each of the above-mentioned regions as a key pattern may be impaired (degraded). Therefore, after calculating the suitability X1 for each region of the entire region 100 on the device 12, the wafer 10 held on the chuck table 7 is rotated within the angular error range of ±3°.

Next, pattern matching is performed between an arbitrary region before rotation, such as region k1 shown in Figure 4(a), and the region k1 after θ rotation shown in Figure 4(b), to calculate the similarity. Because the arbitrary region k1 before rotation and the arbitrary region k1 after rotation are the same region, the similarity is expected to reach the maximum value of 100, even with the aforementioned θ rotation. However, the similarity may decrease from 100 due to factors such as the number of pixels in the image captured by the imaging means 20 and the lighting conditions. This decrease means that if region k1 is selected as a key pattern and the wafer 10 is misaligned in the rotational direction within the angular error θ range, the reliability of proper alignment will decrease. Therefore, as shown in Figure 4(b), the arbitrary region k1 is rotated together with the wafer 10 within the angular error θ range, the similarity to the region k1 before rotation is calculated, and a coefficient (angular error similarity coefficient) for downwardly correcting the suitability X1 is determined. If the wafer 10 held on the chuck table 7 is rotated in multiple stages within the range of the angular error θ, multiple similarities are calculated, and the coefficient for lowering the suitability X1 (angular error similarity coefficient) is determined based on the lowest similarity among the multiple similarities.

Once the angle error similarity coefficient is determined, a corrected aptitude X2 is calculated using the following equation (2), i.e., by multiplying the aptitude X1 calculated based on the above equation (1) by the above angle error similarity coefficient. The angle error similarity coefficient is set to be smaller than 1 as the similarity decreases due to the above θ rotation. For example, if the similarity is 100 despite the θ rotation, the coefficient is set to "1", if the similarity decreases to 80, the coefficient is set to "0.8", and if the similarity decreases to 50, the coefficient is set to "0.5".
Suitability X2 = Suitability X1 × Angle Error Similarity Coefficient (2)

The calculation of formula (2) is performed for each area on the device 12 corresponding to each pattern (e.g., areas k1 to k8, k10), and the suitability X1 assigned to each area is corrected to suitability X2, which is then displayed for each area. According to formula (2) above, it is possible to lower the evaluation of areas whose suitability as key patterns may be impaired if the wafer 10 is misaligned in the rotational direction within the angle error range. By referencing this suitability X2, it has the effect of providing more appropriate assistance to less experienced and less skilled workers when selecting key patterns.

The suitability X1 or suitability X2 calculated based on the above formula (1) or formula (2) can be further modified using the technical concept described below. Note that the following explanation will be given assuming that suitability X2 is modified.

The similarity calculated by the pattern matching described above may vary depending on the amount of light irradiated onto the region imaged by the imaging means 20. Fig. 5(a) shows a region k1 imaged by the imaging means 20 when the wafer 10 is illuminated with a standard amount of light, Fig. 5(b) shows a region k1 imaged by the wafer 10 in a bright state in which the amount of light irradiated onto the wafer 10 is increased compared to Fig. 5(a), and Fig. 5(c) shows a region k1 imaged by the wafer 10 in a dark state in which the amount of light irradiated onto the wafer 10 is decreased compared to Fig. 5(a). In this embodiment, the brightness of the region imaged by the imaging means 20 is changed in this way, and the similarity between the region k1 imaged by illuminating the wafer 10 with the standard illuminance shown in Fig. 5(a) and the bright region k1 shown in Fig. 5(b) and the similarity between the region k1 imaged by illuminating the wafer 10 with the standard illuminance shown in Fig. 5(a) and the dark region k1 shown in Fig. 5(c) are calculated, and the changes therebetween are calculated. For example, if the similarity calculated based on the area k1 when it is brightened as shown in FIG. 5( b) is 90, and the similarity calculated based on the area k1 when it is darkened as shown in FIG. 5( c) is 80, the coefficient 0.8 based on the lowest similarity of 80 is used as the brightness similarity coefficient, and this is multiplied by the suitability X2 calculated as above based on the following equation (3) to calculate the suitability X3, which is the corrected suitability X2.
Suitability X3 = Suitability X2 × Brightness similarity coefficient (3)

The calculation of equation (3) is performed for each region on the device 12 corresponding to each pattern (e.g., regions k1 to k8, k10), and the suitability X2 assigned to each region is corrected to suitability X3, which is then displayed for each region. Note that while the suitability X3 described above is calculated by multiplying the suitability X2 calculated based on equation (2) above by the suitability X3, the present invention is not limited to this. For example, if it is not necessary to assume that the suitability will decrease due to an angle error when holding the wafer 10 on the frame F, the suitability X3 may be calculated by multiplying the suitability X1 calculated based on equation (1) above by the brightness similarity coefficient described above. Performing this suitability correction also allows less experienced and less skilled workers to select key patterns that are less affected by changes in brightness, providing more appropriate assistance.

The suitability scores X1 to X3 calculated based on the above formulas (1) to (3) can be further modified using the technical concepts described below. Note that the following explanation will be given on the assumption that suitability score X3 is modified using the above formula (3).

In the above-described embodiment, an image of the entire area 100 of one device 12 is captured by the imaging means 20 and displayed on the display means M, and an aptitude level is assigned to each of the areas k1 to k8 and k10 that form the key pattern. If the captured area captured by the imaging means 20 and displayed on the display means M is a partial area 110 (a small area indicated by a dashed line in FIG. 3 ) that does not fill the entire area 100, even if an aptitude level is calculated for an arbitrary area using the partial area 110, the reliability is lower than that of the aptitude level calculated using the entire area 100. Therefore, in this embodiment, the aptitude level X3 is corrected by multiplying the aptitude level X3 by the ratio of the area of the captured area to the entire area 100 (captured area/total area) based on the following equation (4), and then the aptitude level X4 is calculated. For example, if the imaging area includes the entire area 100, it is multiplied by "1", and if the imaging area does not fill the entire area 100 but is a partial area 110 that covers only 1/4 of the area of the entire area 100 shown in Figure 3, it is multiplied by, for example, "0.25".
Suitability X4 = Suitability X3 x [imaging area/total area]... (4)

The above-mentioned suitability X4 makes it possible to take into account the reliability of suitability due to the narrow and insufficient area captured by the imaging means 20, motivating the worker to adjust the imaging area to a wider area, and providing more appropriate assistance to workers with less experience and skill when selecting key patterns. While the above-mentioned formula (4) shows an example in which [imaging area/total area] is multiplied by suitability X3, the present invention is not limited to this, and the above-mentioned suitability X1 or suitability X2 may also be multiplied by this to make a correction.

In the above-described embodiment, the operator can refer to the suitability displayed by the assist mechanism and appropriately select a characteristic key pattern, perform alignment using that key pattern, and then use the cutting means 8 to appropriately divide the wafer 10 into individual device chips.

In the above embodiment, the assist mechanism is applied to a cutting device 1 equipped with cutting means 8 that cuts the planned dividing lines 14 of the wafer 10 with a cutting blade as the processing means. However, the present invention is not limited to this. The assist mechanism can also be applied to a laser processing device in which the processing means is a laser beam application means that applies a laser beam to the planned dividing lines 14 of the wafer 10, and the same effects as those described above can be achieved.

1: Cutting device 2: Housing 3: Carrying-in/out means 4: Cassette 5: Temporary placement table 6: Transporting means 7: Chuck table 7a: Holding surface 8: Cutting means 9: Cleaning device 9a: Cleaning and transporting means 10: Wafer 12: Device 14: Planned division line 20: Imaging means 30: Control means M: Display means

Claims (6)

A processing apparatus for processing a wafer having a surface on which a plurality of devices are formed and partitioned by planned division lines,
The wafer processing apparatus includes a chuck table having a holding surface defined by X- and Y-axes for holding a wafer, an imaging means for imaging the wafer held on the chuck table, a display means for displaying the image captured by the imaging means, a processing means for processing the wafer held on the chuck table, an X-axis moving means and a Y-axis moving means for moving the chuck table in the X-axis and Y-axis directions relative to the imaging means and the processing means, and a control means,
The control means
an assist mechanism for displaying an image of the wafer held on the chuck table, which is captured by the imaging means, on the display means and displaying suitability as a key pattern in an area for selecting a key pattern, thereby assisting in the selection of a key pattern ;
the assist mechanism calculates the similarity between an arbitrary region and another region when the arbitrary region is set as a key pattern, and performs a calculation such that the lower the similarity, the higher the suitability of the arbitrary region as a key pattern; and displays the suitability of the arbitrary region on the display means;
A processing device that rotates the chuck table within an angle error range between the planned division line and the X-axis direction, calculates the change in similarity for each area to which the suitability is assigned, and corrects the suitability by multiplying the suitability by a coefficient based on the lowest similarity . A processing apparatus for processing a wafer having a surface on which a plurality of devices are formed and partitioned by planned division lines,
The wafer processing apparatus includes a chuck table having a holding surface defined by X- and Y-axes for holding a wafer, an imaging means for imaging the wafer held on the chuck table, a display means for displaying the image captured by the imaging means, a processing means for processing the wafer held on the chuck table, an X-axis moving means and a Y-axis moving means for moving the chuck table in the X-axis and Y-axis directions relative to the imaging means and the processing means, and a control means,
The control means
an assist mechanism for displaying an image of the wafer held on the chuck table, which is captured by the imaging means, on the display means and displaying suitability as a key pattern in an area for selecting a key pattern, thereby assisting in the selection of a key pattern;
the assist mechanism calculates the similarity between an arbitrary region and another region when the arbitrary region is set as a key pattern, and performs a calculation such that the lower the similarity, the higher the suitability of the arbitrary region as a key pattern; and displays the suitability of the arbitrary region on the display means;
A processing device that changes the brightness of the area captured by the imaging means, calculates the change in similarity for each area to which an appropriateness level has been assigned, and modifies the appropriateness level by multiplying the appropriateness level by a coefficient based on the lowest similarity level . A processing apparatus for processing a wafer having a surface on which a plurality of devices are formed and partitioned by planned division lines,
The wafer processing apparatus includes a chuck table having a holding surface defined by X- and Y-axes for holding a wafer, an imaging means for imaging the wafer held on the chuck table, a display means for displaying the image captured by the imaging means, a processing means for processing the wafer held on the chuck table, an X-axis moving means and a Y-axis moving means for moving the chuck table in the X-axis and Y-axis directions relative to the imaging means and the processing means, and a control means,
The control means
an assist mechanism for displaying an image of the wafer held on the chuck table, which is captured by the imaging means, on the display means and displaying suitability as a key pattern in an area for selecting a key pattern, thereby assisting in the selection of a key pattern;
the assist mechanism calculates the similarity between an arbitrary region and another region when the arbitrary region is set as a key pattern, and performs a calculation such that the lower the similarity, the higher the suitability of the arbitrary region as a key pattern; and displays the suitability of the arbitrary region on the display means;
If the imaging area captured by the imaging means covers the entire area related to one device and assigns a suitability for the key pattern, the processing device multiplies the suitability by 1, and if the imaging area does not cover the entire area, the processing device corrects the suitability by multiplying the suitability by the ratio of the imaging area to the entire area . 4. The processing device according to claim 2 or 3, wherein the chuck table is rotated within an angular error range between the planned division line and the X-axis direction, the change in similarity for each of the areas to which the suitability is assigned is calculated, and the suitability is corrected by multiplying the suitability by a coefficient based on the lowest similarity . The processing device according to claim 3, wherein the brightness of the area imaged by the imaging means is changed, the change in similarity is calculated for each area to which a suitability is assigned, and the suitability is corrected by multiplying the suitability by a coefficient based on the lowest similarity . changing the brightness of the area imaged by the imaging means, calculating a change in similarity for each area to which an aptitude level has been assigned, and correcting the aptitude level by multiplying the aptitude level by a coefficient based on the lowest similarity level;
The processing device of claim 1, wherein if the imaging area captured by the imaging means covers the entire area related to one device and assigns a suitability for the key pattern, the suitability is multiplied by 1, and if the imaging area does not cover the entire area, the suitability is corrected by multiplying the suitability by the ratio of the imaging area to the entire area .