CN109473389B

CN109473389B - Setting method of alignment pattern

Info

Publication number: CN109473389B
Application number: CN201811030602.6A
Authority: CN
Inventors: 渡部晃司; 宫田论
Original assignee: Disco Corp
Current assignee: Disco Corp
Priority date: 2017-09-08
Filing date: 2018-09-05
Publication date: 2024-03-15
Anticipated expiration: 2038-09-05
Also published as: JP2019050258A; TWI791580B; TW201913844A; CN109473389A; JP6979312B2

Abstract

Provided is a method for setting an alignment pattern, which can suppress the reduction of alignment accuracy even if the alignment pattern does not include a characteristic portion. The setting method of the alignment pattern comprises the following steps: an imaging step (ST 1) for imaging an image including the intersection of the streets of the wafer; a specification step (ST 2) for specifying, on an operation screen of the device that displays an image including the intersections, two or more areas including boundaries between the streets and mutually different devices; a whole image creation step (ST 3) for creating a whole image including all the specified areas; a masking step (ST 4) for masking the region other than the specified region in the overall view; a setting step (ST 5) of setting the masked whole image as an alignment pattern; and a storage step (ST 6) for storing the distance between the alignment pattern and the center of the spacer in the width direction.

Description

Setting method of alignment pattern

Technical Field

The present invention relates to a method for setting an alignment pattern used for detecting a processing position when dividing a wafer.

Background

A disk-shaped semiconductor wafer or a wafer such as an optical device wafer having silicon, sapphire, gallium, or the like as a base material is formed with devices in a plurality of regions partitioned by lattice-shaped lines on the front surface. The wafer is divided into individual devices along a dividing line by a processing device such as a laser processing device or a cutting device (for example, refer to patent document 1).

With the processing apparatus shown in patent document 1 and the like, when the above-described wafer is divided in a fully automatic processing manner, the following alignment is performed: image processing such as pattern matching is performed on a preset alignment pattern and an image obtained by photographing a wafer to be processed, so that alignment of a processing unit with respect to the wafer is performed, and the following notch inspection is performed: a determination is made as to whether or not the machining position where the machining is performed by the machining unit is appropriate.

Patent document 1: japanese patent application laid-open No. 2014-203836

Regarding the wafer to be processed in the processing apparatus shown in patent document 1 and the like, it is preferable that an alignment pattern is formed for all devices in order to perform the alignment and the notch inspection described above, and that the alignment pattern includes a characteristic portion that is not included in other portions in order to avoid erroneous recognition as other portions.

Disclosure of Invention

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a method for setting an alignment pattern, which can suppress a decrease in alignment accuracy even if the alignment pattern does not include a characteristic portion.

In order to achieve the above object, the present invention provides a method for setting an alignment pattern for detecting a position of a street when dividing a wafer having a device formed on a front surface thereof and divided into a plurality of streets along the streets, the method comprising: a photographing step of photographing an image including an intersection of the streets; a specifying step of specifying at least two or more areas including a boundary between the spacer and the device in an operation screen of the apparatus displaying the image including the intersection; a whole image creating step of creating a whole image including all the specified areas; masking the region of the whole map except the designated region; a setting step of setting the masked whole image as an alignment pattern; and a storage step of storing a distance between an arbitrary designated region in the alignment pattern and the spacer.

In the method for setting an alignment pattern, in the specifying step, a position where a member or a processing mark formed on the spacer is avoided may be specified as the region.

In the method for setting an alignment pattern, in the specifying step, the region may be specified by drawing on an operation screen of the device that displays an image including the intersection.

The setting method of the alignment pattern of the invention has the following effects: even if the alignment pattern does not include a characteristic portion, a decrease in alignment accuracy can be suppressed.

Drawings

Fig. 1 is a perspective view showing a configuration example of a laser processing apparatus that implements the method for setting an alignment pattern according to embodiment 1.

Fig. 2 is a perspective view of a wafer to be processed in the laser processing apparatus shown in fig. 1.

Fig. 3 is a flowchart showing a flow of a method for setting an alignment pattern according to embodiment 1.

Fig. 4 is a diagram showing an example of an image obtained in the photographing step of the method for setting an alignment pattern shown in fig. 3.

Fig. 5 is a diagram showing an example of a designated step in which the method for setting the alignment pattern shown in fig. 3 is performed on the image shown in fig. 4.

Fig. 6 is a diagram showing an enlarged main portion of the image shown in fig. 5.

Fig. 7 is a diagram showing an example of an overall diagram manufacturing step in which the method for setting the alignment pattern shown in fig. 3 is performed on the image shown in fig. 5.

Fig. 8 is a diagram showing an example of masking steps in which the method for setting the alignment pattern shown in fig. 3 is performed on the image shown in fig. 7.

Fig. 9 is a diagram showing an example of the distance between the alignment pattern and the spacer or the like stored in the storage step of the method for setting an alignment pattern.

Fig. 10 is a diagram showing an example of an image at a step of specifying the alignment pattern setting method according to embodiment 2.

Fig. 11 is a diagram showing an example of an image after the specification step of the method for setting an alignment pattern according to embodiment 2 is performed.

Fig. 12 is a diagram showing an example of an image obtained in the imaging step of the method for setting an alignment pattern according to embodiment 3.

Fig. 13 is a diagram showing an example in which a designation step is performed on an image obtained in the imaging step of the method for setting an alignment pattern according to embodiment 3.

Description of the reference numerals

70: a display unit (device); 71: a screen (operation screen); 100: a wafer; 101: a front face; 102: a spacer; 103: a device; 104: TEG (component); 106: an intersection; 107: a center; 200: an alignment pattern; 201: a distance; 300: an image; 400: a region; 500: an overall diagram; ST1: shooting; ST2: a designating step; ST3: a step of overall graph manufacture; ST4: masking; ST5: setting; ST6: and a storage step.

Detailed Description

The mode (embodiment) for carrying out the present invention will be described in detail with reference to the accompanying drawings.

The present invention is not limited to the following embodiments. The constituent elements described below include those that can be easily understood by those skilled in the art and those that are substantially the same. The structures described below may be appropriately combined. Various omissions, substitutions and changes in the structure may be made without departing from the spirit of the invention.

Embodiment 1

A method of setting an alignment pattern according to embodiment 1 of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing a configuration example of a laser processing apparatus that implements the method for setting an alignment pattern according to embodiment 1. Fig. 2 is a perspective view of a wafer to be processed in the laser processing apparatus shown in fig. 1.

The method of setting the alignment pattern according to embodiment 1 is a method performed when dividing the wafer 100 shown in fig. 1 and 2 by a processing apparatus used in a semiconductor manufacturing process or the like. The processing device is a laser processing device 1 shown in fig. 1 for dividing a wafer 100 by laser processing or a cutting device for cutting the wafer 100 to divide the wafer.

The wafer 100 is a disk-shaped semiconductor wafer or an optical device wafer using silicon, sapphire, gallium, or the like as a base material. As shown in fig. 2, a wafer 100 has devices 103 formed on a front surface 101 and divided in a lattice by a plurality of streets 102. In addition, the wafer 100 is formed with a TEG (Test Element Group: test element group) 104 as a component on the streets 102. The TEG 104 is formed of metal or the like, and is a test pattern for finding problems in design and manufacture of the device 103. The TEG 104 is disposed at a predetermined position of the streets 102 of the wafer 100.

In embodiment 1, the arrangement positions of the TEGs 104 are different from one another in the streets 102, but in the present invention, the wafer 100 may have a plurality of streets 102 in which the TEGs 104 are arranged at the same position. Fig. 2 shows the TEGs 104 disposed in some of the streets 102, and the TEGs 104 disposed in other streets 102 are omitted. In embodiment 1, the wafer 100 has the TEG 104 as a member formed on the streets 102, but in the present invention, the dummy pattern for CMP (Chemical Mechanical Polishing: chemical mechanical polishing) may be formed as a member without being limited to the TEG 104. The dummy pattern of CMP is formed on the streets 102 to uniformly grind the wafer 100 during CMP polishing and to suppress thickness variation, and is made of metal, oxide film, resin, or the like. In embodiment 1, the wafer 100 is integrated with the ring frame 111 by attaching the adhesive tape 110 to the back surface 105 on the back surface side of the front surface 101 and providing the ring frame 111 outside Zhou Niantie of the adhesive tape 110.

As shown in fig. 1, a laser processing apparatus 1 as an example of a processing apparatus includes: a chuck table 10 for holding the wafer 100 by suction by the holding surface 11 and capable of rotating around an axis by a rotation driving source; a laser beam irradiation unit 20 that irradiates the wafer 100 with laser beams having a wavelength that is absorptive to the wafer 100 held by the chuck table 10; an X-axis moving unit, not shown, that moves the chuck table 10 in the X-axis direction; and a Y-axis moving unit, not shown, that moves the chuck table 10 in the Y-axis direction. The laser processing device 1 further includes: a cassette lifter 40 for placing the cassette 30 storing the wafers 100 before and after laser processing and lifting the cassette 30 in the Z-axis direction; a not-shown transport unit for transporting the wafer 100 between the cassette 30 and the chuck table 10; a photographing unit 50 photographing the wafer 100 held by the chuck table 10; and a control unit 60 which is a computer that controls each component.

The laser beam irradiation unit 20 has a processing head 21 which is opposed to the wafer 100 held by the chuck table 10 and irradiates laser beams. The photographing unit 50 is mounted to the processing head 21 of the laser beam irradiation unit 20. The imaging unit 50 includes a CCD (Charge Coupled Device: inductive coupler) imaging element or the like for imaging the front surface 101 of the wafer 100 held by the chuck table 10. The photographing unit 50 outputs the photographed image to the control unit 60.

The control unit 60 controls the above-described components of the laser processing apparatus 1, respectively, so that the laser processing apparatus 1 performs a processing operation for the wafer 100. In addition, the control unit 60 is a computer. The control unit 60 has: an arithmetic processing device having a microprocessor such as a CPU (central processing unit: central processing unit); a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory: random access memory); and an input/output interface device.

The arithmetic processing device of the control unit 60 performs arithmetic processing in accordance with a computer program stored in the storage device, and outputs a control signal for controlling the laser processing device 1 to the above-described constituent elements of the laser processing device 1 via the input/output interface device. The control unit 60 is connected to a display unit 70 for displaying the state of the machining operation, an image, and the like, and an input unit 80 for use when an operator registers machining content information and the like.

The display unit 70 includes: a liquid crystal display (liquid crystal display), an organic electro-luminescence display, or an inorganic EL display (Inorganic electro-luminescence display). The screen 71 of the display device is an operation screen. The display unit 70 displays characters, images, signs, graphics, and the like in the screen. In addition, the display unit 70 displays the image captured by the capturing unit 50.

The input unit 80 has: a touch panel 81 overlapped with the screen 71 of the display device constituting the display unit 70; and an external input device such as a keyboard, not shown. The touch panel 81 detects contact or proximity of a finger, pen, stylus, or the like. The touch panel 81 can detect a position on the touch panel 81 when a plurality of fingers, pens, or styluses are in contact or proximity. In the following description, the positions where a plurality of fingers, pens, touch pens, and the like detected by the touch panel 81 are in contact with or come close to each other are denoted as "detection positions". The input unit 80 outputs the contact or proximity of the finger or the like to the control unit 60 together with the detection position.

The laser processing apparatus 1 performs ablation processing by relatively moving the chuck table 10 and the processing head 21 along the streets 102 by the X-axis moving means, the rotation driving source, and the Y-axis moving means while irradiating the wafer 100 with laser light from the processing head 21 of the laser light irradiation means 20, and forms laser processing grooves in the streets 102. In embodiment 1, a wafer 100 having a laser processing groove formed in a spacer 102 by a laser processing apparatus 1 is divided into individual devices 103 by breaking along the laser processing groove or the like.

The control unit 60 of the laser processing apparatus 1 outputs the image captured by the capturing unit 50 to the display unit 70, and displays the image on the display unit 70. The control unit 60 performs alignment before laser processing of the wafer 100, performs alignment of the wafer 100 and the processing head 21, performs notch inspection during laser processing of the wafer 100, and determines the position of the laser processing groove actually formed in the streets 102 and the size of the edge chipping that can be allowed to be formed at both edges in the width direction of the laser processing groove. When the laser processing apparatus 1 performs alignment, the control unit 60 performs image processing such as pattern matching on the alignment pattern 200 stored in advance in the storage device and the image captured by the capturing unit 50.

Next, a method for setting the alignment pattern according to embodiment 1 will be described. Fig. 3 is a flowchart showing a flow of a method for setting an alignment pattern according to embodiment 1. Fig. 4 is a diagram showing an example of an image obtained in the photographing step of the method for setting an alignment pattern shown in fig. 3. Fig. 5 is a diagram showing an example of a designated step in which the method for setting the alignment pattern shown in fig. 3 is performed on the image shown in fig. 4. Fig. 6 is a diagram showing an enlarged main portion of the image shown in fig. 5. Fig. 7 is a diagram showing an example of an overall diagram manufacturing step of performing the method for setting the alignment pattern shown in fig. 3 on the image shown in fig. 5. Fig. 8 is a diagram showing an example of masking steps in which the method for setting the alignment pattern shown in fig. 3 is performed on the image shown in fig. 7. Fig. 9 is a diagram showing an example of the distance between the alignment pattern and the spacer or the like stored in the storage step of the method for setting an alignment pattern.

The method for setting the alignment pattern according to embodiment 1 (hereinafter, abbreviated as a setting method) is as follows: when a laser processing groove is to be formed on the streets 102 of the wafer 100 to divide the wafer 100 into individual devices 103 along the streets 102, an alignment pattern 200 for detecting the positions of the streets 102 is set. The alignment pattern 200 is image information for pattern matching when detecting (i.e., performing alignment) the position (coordinate information) of the laser processing groove processed by the spacer 102 by the control unit 60 of the laser processing apparatus 1, and the alignment pattern 200 is set by the setting method of embodiment 1 and stored in the storage device. In embodiment 1, the position (coordinate information) shows the coordinates in the X-axis direction and the Y-axis direction with respect to a preset reference position of the wafer 100.

In the setting method, first, an operator places the cassette 30 accommodating the wafer 100 integrated with the ring frame 111 on the cassette elevator 40 of the laser processing apparatus 1, and the operator operates the input unit 80 to register the position of the front surface 101 of the wafer 100 imaged by the imaging unit 50 at the time of alignment execution in the control unit 60. In embodiment 1, the position of the front surface 101 of the wafer 100 imaged when alignment is performed is a position at which the intersection 106 (shown in fig. 2) where the streets 102 intersect with each other can be imaged. As shown in fig. 3, the setting method includes an imaging step ST1, a specifying step ST2, an overall view creating step ST3, a masking step ST4, a setting step ST5, and a storing step ST6.

The photographing step ST1 is a step of photographing an image 300 (shown in fig. 4) including the intersection 106 of the streets 102 of the wafer 100. In the photographing step ST1, when the operator inputs a setting start instruction of the alignment pattern 200 by operating the input unit 80, the control unit 60 extracts one wafer 100 before laser processing from the cassette 30 by the conveying unit, places the wafer on the holding surface 11 of the chuck table 10, and suctions and holds the wafer 100 by the holding surface 11 of the chuck table 10.

Next, the control unit 60 moves the chuck table 10 by the X-axis moving unit toward the lower side of the processing head 21 of the laser beam irradiation unit 20, and places a position to be imaged when the wafer 100 held by the chuck table 10 is aligned under the imaging unit 50 attached to the processing head 21, and images the front surface 101 of the wafer 100 by the imaging unit 50. As shown in fig. 4, the control unit 60 displays an image 300 including the intersection 106 of the streets 102 on the front surface 101 of the wafer 100, which is captured by the capturing unit 50, on a screen 71 that is an operation screen of the display unit 70. Since the image 300 is an image captured by the imaging unit 50, it is an image showing the intensity of light at a predetermined gray level, that is, an image having a shade. When the image 300 is displayed on the screen 71 of the display unit 70, the setting method proceeds to the designation step ST2.

The designation step ST2 is the following step: at least two or more areas 400 including boundaries between the streets 102 and the mutually different devices 103 are specified in the screen 71 of the display unit 70, which is a device that displays the image 300 including the intersections 106. In the embodiment, in the specification step ST2, the operator moves the stylus 90 in contact with the outer edge of the region 400 surrounding the boundary between the street 102 including the image 300 displayed on the screen 71 of the display unit 70 and each device 103 and avoiding the position of the TEG 104 disposed in the street 102, and draws the image with the stylus 90.

In the specification step ST2, the control unit 60 detects the locus of movement of the stylus 90 on the screen 71 as the position of the outer edge of the area 400 from the detection position of the stylus 90 of the touch panel 81 of the input unit 80, and stores the locus in the storage device. In embodiment 1, the drawing is performed by the stylus 90 in the specification step ST2, but the present invention is not limited to the stylus 90, and the drawing may be performed by a finger or a pen.

When detecting and storing the position of the outer edge of the area 400, the control unit 60 detects the position of the stylus 90 of the touch panel 81 of the input unit 80 in units of pixels of the screen 71 of the display unit 70, and for example, counts the pixels of the detected position of the stylus 90 of the touch panel 81 as "1", and counts the pixels other than the detected position as "0". The control unit 60 calculates the position of the outer edge of the region 400 from the positions of the pixels which have been digitized as described above, the registered positions of the front surface 101 of the wafer 100 which are imaged by the imaging unit 50 at the time of alignment execution, and the like, and specifies the region 400. In addition, in the designation step ST2, as shown in fig. 5, the control unit 60 displays the designated area 400 on the screen 71 of the display unit 70. In embodiment 1, in the specification step ST2, four areas 400 are specified, but in the present invention, the number is not limited to four, and two or more areas 400 may be specified.

In addition, when the outer edge of the region 400 is discontinuous as shown in fig. 6, the control unit 60 connects the two ends 401 and 402 of the discontinuity to each other by the shortest line as shown by the broken line in fig. 6, and calculates the position of the outer edge of the region 400. In this way, in the specification step ST2, the operator specifies, as the region 400, at least two or more positions that avoid the boundary between the streets 102 and the devices 103 including the image 300 displayed on the screen 71 of the display unit 70 and the TEG 104 disposed in the streets 102. In addition, in the specification step ST2, the operator specifies the region 400 by drawing on the screen 71 displayed on the image 300 of the display unit 70 with the stylus 90. When the operator operates the input means 80 to input the content for which the specification of the area 400 is completed, the setting method proceeds to the overall diagram creation step ST3.

The entire map creation step ST3 is a step of creating the entire map 500 including all the areas 400 designated in the designation step ST2. In the overall map creation step ST3, the control unit 60 calculates the largest coordinate and the smallest coordinate among the coordinates in the X-axis direction and the Y-axis direction of each designated region 400. The control unit 60 calculates a largest X-axis direction coordinate 501 among a plurality of largest coordinates and a smallest X-axis direction coordinate 502 among a plurality of smallest coordinates of the X-axis directions of all the regions 400, and calculates a largest Y-axis direction coordinate 503 among a plurality of largest coordinates and a smallest Y-axis direction coordinate 504 among a plurality of smallest coordinates of the Y-axis directions of all the regions 400.

The control unit 60 creates an overall map 500 of the area surrounded by the largest X-axis direction coordinate 501, the smallest X-axis direction coordinate 502, the largest Y-axis direction coordinate 503, and the smallest Y-axis direction coordinate 504. In the overall view creating step ST3, as shown in fig. 7, the control unit 60 displays an overall view 500 on the screen 71 of the display unit 70. When the control unit 60 creates the whole map 500, the setting method proceeds to masking step ST4.

The masking step ST4 is a step of masking the region other than the designated region 400 in the entire map 500. In masking step ST4, control section 60 performs image processing to make the outer sides of all areas 400 displayed in overall view 500 of display section 70 black as shown by hatching in fig. 8, thereby forming mask 510. That is, in masking step ST4, control unit 60 forms the outer sides of all regions 400 in overall diagram 500 as mask 510. In the present invention, in masking step ST4, control section 60 may perform image processing to make the outer sides of all areas 400 in overall view 500 displayed on display section 70 white to form mask 510. When the control unit 60 forms the mask 510, the setting method proceeds to the setting step ST5.

The setting step ST5 is a step of setting the entire map 500 on which the mask 510 is formed as the alignment pattern 200. In the setting step ST5, the control unit 60 sets the entire map 500 including the mask 510 and each region 400 shown by the intensity of light of a predetermined gray scale as the alignment pattern 200, and stores the alignment pattern in the storage device. When the control unit 60 stores the alignment pattern 200, the setting method proceeds to the storage step ST6.

The storage step ST6 is a step of storing the distance 201 (shown in fig. 9) between the arbitrary region 400 in the alignment pattern 200 and the center 107 in the width direction of the spacer 102. In addition, in the present invention, in the storage step ST6, the distance between the arbitrary region 400 and the end of the spacer 102 may be stored, and in any case, the distance between the arbitrary region 400 and the arbitrary position of the spacer 102 may be stored. In the storage step ST6, the operator operates the input unit 80 to input the distance 201 between any one area 400 of the plurality of areas 400 of the alignment pattern 200 and the center 107 of the spacer 102 in the width direction, and the control unit 60 stores the input distance 201 in the storage device and displays the center 107 of the spacer 102 on the screen 71 of the display unit 70 as shown in fig. 9. The setting method ends when the control unit 60 stores the distance 201.

When the alignment is performed, the control unit 60 of the laser processing apparatus 1 in which the alignment pattern 200 is set as described above photographs the position to be photographed when the alignment is performed, which is registered in advance in the front surface 101 of the wafer 100, with the photographing unit 50. When performing alignment, the control unit 60 performs image processing such as pattern matching on the image captured by the capturing unit 50 and the image of the region 400 of the alignment pattern 200. The control unit 60 calculates the position of the spacer 102 from the image or the like captured by the capturing unit 50, based on the result of the image processing.

The control unit 60 rotates the chuck table 10 around the axis so that one of the perpendicular streets 102 is parallel to the X-axis direction, and aligns the wafer 100 with the processing head 21 of the laser beam irradiation unit 20 so as to irradiate the laser beam at a position spaced from the region 400 by the distance 201 stored in the storage step ST6. The control unit 60 rotates the wafer 100 by 90 degrees around the axis by the rotation driving source, and performs alignment of the other one of the streets 102 perpendicular to each other in the same manner as the one. The control unit 60 causes the processing head 21 of the laser beam irradiation unit 20 and the wafer 100 to move relatively along the streets 102 by using the X-axis movement unit, the Y-axis movement unit, and the rotational drive source according to the processing conditions, and forms laser processing grooves in the streets 102.

The setting method of embodiment 1 specifies four areas 400 including boundaries between the streets 102 and the mutually different devices 103 in the specification step ST2. Thus, the set-up method includes an area 400 in the alignment pattern 200 that includes boundaries between the plurality of streets 102 and the device 103. As a result, the setting method can perform alignment using the plurality of regions 400 including the boundaries between the plurality of streets 102 and the device 103, and therefore, even if the regions 400, that is, the alignment pattern 200, do not include a characteristic portion, a decrease in alignment accuracy can be suppressed.

In addition, the setting method of embodiment 1 designates, as the region 400, a position where the TEG 104 disposed in the spacer lane 102 is avoided in the designating step ST2, and forms, as the mask 510, the outside of the region 400 of the entire map 500 in the masking step ST4. Therefore, the alignment pattern 200 set in the setting method can be suppressed from including the TEG 104 disposed in the spacer 102. As a result, the setting method can suppress the alignment pattern 200 from including the TEG 104 that reflects light, and thus can suppress a decrease in accuracy of alignment.

In addition, since the setting method according to embodiment 1 is performed by drawing on the screen 71 of the display unit 70 to designate the region 400, the region 400 can be easily designated, and the alignment pattern 200 can be easily set.

Embodiment 2

A method of setting an alignment pattern according to embodiment 2 of the present invention will be described with reference to the drawings. Fig. 10 is a diagram showing an example of an image at a step of specifying the alignment pattern setting method according to embodiment 2. Fig. 11 is a diagram showing an example of an image after the specification step of the method for setting an alignment pattern according to embodiment 2 is performed. In fig. 10 and 11, the same reference numerals are given to the same parts as those in embodiment 1, and the description thereof is omitted.

The method of setting an alignment pattern according to embodiment 2 (hereinafter, abbreviated as "setting method") is similar to the method of embodiment 1 except that the method of setting an alignment pattern according to embodiment 1 is different from embodiment 1 in the specification step ST2.

In the specification step ST2 of the setting method of embodiment 2, as shown in fig. 10, the control unit 60 displays the specified area 600 in the displayed image 300 on the screen 71 of the display unit 70, and moves the specified area 600 on the image 300 in accordance with the operation of the operator from the input unit 80. When an operator operation for determining the position of the specified area 600 is input from the input unit 80, as shown in fig. 11, the control unit 60 designates the determined specified area 600 as the above-described area 400 (calculates and stores the position of the outer edge) as in embodiment 1. In embodiment 2, the planar shape of the designated area 600 is rectangular, and only the corners 601 of the designated area 600 are displayed on the image 300, but in the present invention, the shape and display method of the designated area 600 are not limited to those shown in embodiment 2.

The setting method of embodiment 2 specifies four areas 400 including boundaries between the streets 102 and the mutually different devices 103 in the specification step ST2. Therefore, the setting method can suppress a decrease in alignment accuracy even if the region 400, i.e., the alignment pattern 200 does not include a characteristic portion, as in embodiment 1, in which the region 400 including the boundaries between the plurality of streets 102 and the device 103 is included in the alignment pattern 200.

Embodiment 3

A method of setting an alignment pattern according to embodiment 3 of the present invention will be described with reference to the drawings. Fig. 12 is a diagram showing an example of an image obtained in the imaging step of the alignment pattern setting method according to embodiment 3. Fig. 13 is a diagram showing an example in which a designation step is performed on an image obtained in the imaging step of the method for setting an alignment pattern according to embodiment 3. In fig. 12 and 13, the same reference numerals are given to the same portions as those in embodiment 1, and the description thereof is omitted.

The method of setting an alignment pattern (hereinafter, abbreviated as a setting method) according to embodiment 3 is the same as that according to embodiment 1 except that laser scores as processing marks are arranged on the streets 102 of the wafer 100 as shown in fig. 12. In the case where a Low-k dielectric film (Low-k film) is formed on the front surface 101 of the wafer 100, the laser scores 108 are formed at both ends in the width direction of each of the streets 102 in order to prevent the Low-k dielectric film from peeling off due to cutting processing. The laser scoring 108 is a so-called laser-machined groove formed parallel to the streets 102 by performing ablation processing using laser light on both ends in the width direction of each street 102. The low dielectric constant insulator film is composed of an inorganic film such as SiOF or BSG (SiOB) and an organic film which is a polymer film such as polyimide or parylene.

In the specification step ST2 of the setting method of embodiment 3, the operator draws the outer edge of the region 400 using the stylus 90, and the control unit 60 calculates the position of the outer edge of the region 400 to specify the region 400, and the region 400 includes the boundary between the streets 102 and the devices 103 of the image 300 displayed on the screen 71 of the display unit 70, and surrounds the positions avoiding the TEG 104 and the laser mark 108 arranged on the streets 102. In addition, in the designation step ST2, as shown in fig. 13, the control unit 60 displays the designated area 400 on the screen 71 of the display unit 70. In this way, in the specification step ST2 of the setting method of embodiment 3, the position avoiding the TEG 104 and the laser score 108 is specified as the region 400, but in the present invention, when only the laser score 108 is arranged without arranging the TEG 104 on the streets 102, it is desirable to specify the position avoiding the laser score 108 as the region 400 in the specification step ST2. That is, in the specification step ST2, the present invention specifies the position of at least one of the laser mark 108, which is the processing mark, and the part such as the dummy pattern for the TEG 104 and CMP, which is avoided, as the region 400.

The setting method of embodiment 3 specifies four areas 400 including boundaries between the streets 102 and the mutually different devices 103 in the specification step ST2. Therefore, in the setting method, as in embodiment 1, even if the region 400, that is, the alignment pattern 200 does not include a characteristic portion, it is possible to suppress a decrease in alignment accuracy.

In addition, in the setting method according to embodiment 3, in the designating step ST2, the positions of the TEG 104 and the laser score 108, which are disposed avoiding the streets 102, are designated as the areas 400. As a result, the setting method can suppress the alignment pattern 200 from including the TEG 104 and the laser scribe 108 that reflect light, and thus can suppress a decrease in accuracy of alignment.

The present invention is not limited to the above embodiment. That is, various modifications may be made and implemented within a range not departing from the gist of the present invention. In addition, although the laser processing apparatus 1 is described as an example of the processing apparatus in the above-described embodiments 1 and 2, the alignment pattern setting method of the present invention can be used in a cutting apparatus.

Claims

1. A setting method of an alignment pattern for detecting a position of a street while dividing a wafer having a device formed on a front surface thereof and divided into a plurality of streets in a lattice form along the streets, the setting method comprising the steps of:

a photographing step of photographing an image including an intersection of the streets;

a specifying step of specifying at least two or more areas including a boundary between the spacer and the device in an operation screen of the apparatus displaying the image including the intersection;

a whole image creating step of creating a whole image including all the specified areas;

a masking step of forming a mask on the outside of the designated region in the overall view;

a setting step of setting an overall image including the specified areas and the mask as an alignment pattern; and

and a storage step of storing a distance between an arbitrary specified region in the alignment pattern and the spacer.

2. The method for setting an alignment pattern according to claim 1, wherein,

image processing is performed on the image obtained by photographing the wafer and the image of the region of the alignment pattern, and the position of the spacer is calculated from the result of the image processing.

3. The method for setting an alignment pattern according to claim 1, wherein,

in the whole map creation step, a region surrounded by the maximum coordinate and the minimum coordinate among the respective coordinates in the X-axis direction and the Y-axis direction of the region specified in the specification step is created as a whole map.

4. The method for setting an alignment pattern according to any one of claims 1 to 3, wherein,

in the specifying step, a position where a part or a processing mark formed on the spacer is avoided is specified as the region.

5. The method for setting an alignment pattern according to any one of claims 1 to 3, wherein,

in the designating step, the region is designated by drawing on an operation screen of the apparatus that displays an image including the intersection.