KR20140057139A - Laser processing apparatus and method of establishing processing condition of a substrate with pattern - Google Patents

Abstract

The present invention relates to a method for establishing machining conditions capable of well chipping a substrate having a pattern. The method for establishing machining conditions in chopping a substrate with a pattern by irradiating the substrate with laser light to allow the machining marks formed on the substrate to be dispersed along the machining expecting line and extends cracks from the machining marks includes the steps of conducting the crack extending as temporary machining on partial positions of the substrate with the pattern and determining an offset direction of the irradiated position of the laser light by using a first profile obtained by adding pixel values up along the machining direction upon the temporary machining with respect to first photographed image obtained by photographing the temporary machining conducting positions in the state where a focus is taken on the principal plane of the substrate with the pattern.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a laser processing apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of setting a processing condition in dividing a substrate having a pattern formed by repeatedly arranging a plurality of unit patterns two-dimensionally on a substrate, And a setting method.

An LED element is a substrate in which a pattern formed by repeatedly forming a unit pattern of an LED element two-dimensionally on a wafer or a mother substrate (a substrate having an LED pattern) such as sapphire single crystal, Is divided into a predetermined area to be divided, which is called a street formed in a lattice shape, and is made into a piece of material (chip). Here, And is a narrow width region which is a gap portion of two parts serving as elements.

As a method for such division, a laser beam, which is ultrarapid pulsed light with a pulse width of psec order, is irradiated to a region where a to-be-irradiated region of each unit pulse beam is discrete A method of forming a starting point for division along a line to be machined (usually a street center position) is already known (see, for example, Patent Document 1). In the technique disclosed in Patent Document 1, cracks due to cleavage or cracking between the processing traces formed in the irradiated regions of the respective single pulse lights (cracks And the substrate is divided along these cracks, thereby realizing the disassembly.

Japanese Laid-Open Patent Publication No. 2011-131256

In a substrate having a pattern as described above, a unit pattern is usually arranged in a direction parallel to an orientation flat formed on a sapphire single crystal substrate and along a direction orthogonal to the orientation flat. Thus, for a substrate with such a pattern, streets are made extending in a direction parallel to and perpendicular to the orientation flat.

When a substrate having such a pattern is divided by a technique as disclosed in Patent Document 1, laser light is naturally irradiated along streets parallel to the orientation flat and streets perpendicular to the orientation flat. In this case, the extension of the crack from the processing trace accompanying the irradiation of the laser beam occurs not only in the irradiation direction (scanning direction) of the laser beam, which is also the extending direction of the line to be processed, but also in the thickness direction of the substrate.

However, when laser light is irradiated along a street parallel to the orientation flat, the crack extension in the thickness direction of the substrate occurs in a direction perpendicular to the processing trace. On the other hand, along the street perpendicular to the orientation flat, It is empirically known that when irradiated with light, there is a difference in the crack as it is stretched in an oblique direction from the vertical direction, not in the vertical direction. In addition, the directions in which these cracks are inclined coincide with each other in the same wafer plane, but they may differ depending on substrates having individual patterns.

In addition, in the sapphire single crystal substrate used for the patterned substrate, the plane orientation of the crystal planes such as the c-plane and the a-plane coincides with the normal direction of the main surface, and besides, the direction perpendicular to the orientation flat is inclined (Hereinafter also referred to as an off substrate) provided with a so-called off angle, which is inclined with respect to the normal direction by giving the plane orientation of these crystal planes, may be used, but it is also possible to use a substrate perpendicular to the aforementioned orientation flat It has been confirmed by the inventors of the present invention that the inclination of the crack in the case of irradiating the laser beam occurs not on the off substrate but on the off substrate as well.

On the other hand, it is desirable that the width of the street is narrower in view of the demand for improvement in the number of LEDs per unit area or the like. However, when the technique disclosed in Patent Document 1 is applied to a substrate having a narrow pattern of such a street, in streets perpendicular to the orientation flat, the inclined crack does not stay in the width of the street, There arises a problem that it reaches the region where the LED element is formed. The occurrence of such a problem is undesirable because it causes a decrease in the yield of the LED element.

In order to suppress the deterioration of the yield, it is necessary to specify the direction in which the cracks are inclined when processing the substrate having the individual patterns, and accordingly, to set the processing conditions such as the processing position. In the mass production process, it is required to quickly set the processing conditions for the substrate having the individual patterns in order to improve processing productivity.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of setting processing conditions and an apparatus for realizing the processing conditions so that a substrate having a pattern can be satisfactorily separated.

According to a first aspect of the present invention, there is provided a semiconductor device comprising: an emission source for emitting a laser beam; a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns two-dimensionally on a four- 1. A laser processing apparatus having a fixable stage and capable of irradiating the substrate with the pattern while scanning the laser light along a predetermined line to be machined by relatively moving the outgoing source and the stage, A laser beam is radiated onto the substrate having the pattern by the pulse light so that the laser beam is discretely positioned along the expected line to be machined, It is possible to perform the crack extension processing, and the pattern placed on the stage Further comprising an offset condition setting means for setting an offset condition for offsetting the irradiated position of the laser beam from the line to be processed at the time of the crack extension processing, wherein the offset condition setting means sets, Wherein a portion of the substrate having the pattern is set as an execution position of the crack extension processing for setting the offset condition and the machining process for the offset condition setting is performed on the execution position A step of obtaining a first captured image by capturing an image of the execution position of the processing in a state of focusing on a main surface of the substrate having the pattern, Using the first profile obtained by integrating the pixel values along the processing direction of the dummy disclosure, And at the time of processing that must be offset a direction of the laser beams in the irradiation position, wherein the specific.

The invention according to claim 2 is the laser machining apparatus according to claim 1, wherein the offset condition setting means acquires the first picked-up image to the image pickup means, And a second picked-up image is obtained by picking up the above-mentioned execution position of the above-mentioned machining in a state in which the machining trace is formed by the above-mentioned machining, On the basis of a positional coordinate of the machining trace of the second picked-up image and a positional coordinate of the machining trace of the machining, which is specified from the second profile obtained by integrating the pixel values along the machining direction of the tentative disclosure with respect to the second picked- And the direction in which the irradiation position of the laser beam should be offset during the crack extension processing is specified.

The invention according to claim 3 is the laser machining apparatus according to claim 1, wherein the offset condition setting means sets, based on the slope of two approximate curves sandwiching an extremal value in the first profile, And specifies the direction in which the irradiation position of the laser light should be offset at the time of processing.

According to a fourth aspect of the present invention, there is provided a semiconductor laser device comprising: an outgoing source for emitting laser light; and a stage capable of fixing a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns two-dimensionally on a single crystal substrate, A laser processing apparatus capable of irradiating the substrate with the pattern while scanning the laser light along a predetermined line to be machined by relatively moving the stage, characterized in that the laser processing apparatus is formed on the substrate having the pattern by each unit pulse light of the laser light The laser beam is irradiated so that a machining mark is discretely positioned along the line to be machined so that crack extension machining can be carried out to extend a crack from the respective machining marks to the patterned substrate, An imaging means capable of imaging a substrate on which the pattern is placed, Further comprising an offset condition setting means for setting an offset condition for offsetting the irradiation position of the laser beam from the line to be processed at the time of thermal expansion processing, wherein the offset condition setting means sets a part of the substrate Wherein said control means sets said offset position as an execution position of said crack extension processing for setting said offset condition and after said crack extension processing for setting said offset condition is performed, In a state in which the focal point of the laser beam is focused and the first picked-up image is picked up by picking up the above-mentioned execution spot in the state of focusing on the main surface of the laser beam, Acquires a second captured image from the first captured image, On the basis of the difference between the position coordinate of the end of the crack extending from the machining trace formed by the machining process and the position coordinate of the machining trace of the machining process specified from the second picked-up image, And specifies the direction in which the irradiation position of the laser light should be offset at the time of processing.

The invention according to claim 5 is the laser machining apparatus according to claim 4, wherein the offset condition setting means sets the offset value for each of the first picked-up image and the second picked-up image by accumulating pixel values along the processing direction of the tilting And the position coordinates of the end of the crack generated in the dummy disclosure and the position coordinates of the processing trace in the dummy disclosure are specified based on the obtained integration profile.

The invention according to claim 6 is the laser machining apparatus according to claim 2, claim 4, or claim 5, wherein the offset condition setting means sets the irradiation position of the laser light at offset Is determined on the basis of the individual information of the substrate having the pattern to be subjected to the crack extension processing that has been obtained in advance.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: irradiating a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns two-dimensionally on a single crystal substrate, A method for setting a condition, the method comprising: a step of disposing a substrate having the pattern thereon, wherein processing marks formed on the substrate having the pattern by each unit pulse light of the laser light are dispersed along the expected line Wherein the laser beam is irradiated with the laser beam so that a crack is propagated in the substrate having the pattern from each of the processing traces, wherein, prior to the crack extension processing, An offset condition setting step of setting an offset condition for offsetting from a predetermined line Wherein the offset condition setting step sets a part of the substrate having the pattern as an execution position of the crack expansion processing for setting the offset condition and sets the crack extension part for the offset condition setting An image pickup step of picking up a first picked-up image by picking up an image of the execution position of the processing in a state in which a predetermined image pickup means is focused on a main surface of the substrate having the pattern; An offset specifying the direction in which the irradiation position of the laser beam should be offset during the crack extension processing by using a first profile obtained by integrating pixel values along the processing direction of the dazzling disclosure with respect to the first captured image, And a direction specifying step.

According to an eighth aspect of the invention, there is provided a processing condition setting method for a substrate having a pattern as set forth in claim 7, wherein in the imaging step, the first imaging image is acquired by the imaging means, In the offset direction specifying step, the second picked-up image is picked up by picking up the execution position of the machining while focusing on the focal point position of the laser beam of the laser beam, And a second profile obtained by integrating a pixel value along a machining direction of the second picked-up image with respect to the second picked-up image and a second profile obtained by integrating pixel values along the machining direction of the second picked- On the basis of the difference value between the irradiation position of the laser beam and the position coordinate, It should be the direction wherein certain.

According to a ninth aspect of the present invention, there is provided a method of setting a processing condition for a substrate having a pattern according to the seventh aspect, wherein in the offset direction specifying step, based on the slope of two approximate curves sandwiching the extremum in the first profile, And the direction in which the irradiation position of the laser beam should be offset during the crack extension processing is specified.

According to the invention of claim 10, there is provided a substrate processing method for processing a substrate having a pattern by irradiating a laser beam onto a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns on a single crystal substrate two-dimensionally, A method for setting a condition, the method comprising: a step of disposing a substrate having the pattern thereon, wherein processing marks formed on the substrate having the pattern by each unit pulse light of the laser light are dispersed along the expected line Wherein the laser beam is irradiated with the laser beam so that a crack is propagated in the substrate having the pattern from each of the processing traces, wherein, prior to the crack extension processing, An offset condition setting step of setting an offset condition for offsetting from a predetermined line Wherein the offset condition setting step sets a part of the substrate having the pattern as an execution position of the crack expansion processing for setting the offset condition and sets the crack extension part for the offset condition setting A step of picking up a first picked-up image by picking up an image of the execution position of the processing in a state in which a predetermined image pickup means is focused on a main surface of the substrate having the pattern, An image pickup step of picking up a second picked-up image by picking up an image of the execution position of the machining in a state in which the focal point of the laser beam is focused at the time of performing the machining; Position coordinates of an end of a crack propagated from a processing trace formed by the machining process, And an offset direction specifying step of specifying a direction in which the irradiation position of the laser beam should be offset during the crack extension processing based on a difference value between the position coordinate of the machining trace and the machining traces.

According to an eleventh aspect of the present invention, there is provided a processing condition setting method for a substrate having a pattern as set forth in claim 10, wherein in the offset direction specifying step, in each of the first captured image and the second captured image, The position coordinates of the end of the crack generated in the dummy disclosure and the position coordinates of the processing trace in the dummy disclosure are specified based on the integration profile obtained by integrating the pixel values along the line.

According to a twelfth aspect of the invention, there is provided a processing condition setting method for a substrate having a pattern according to any one of the eighth, twelfth, and eleventh aspects, wherein the offset condition setting step comprises: Characterized by further comprising an offset amount determining step of determining an offset amount when offsetting from the line to be machined is determined based on individual information of a substrate having the pattern to be subjected to the machining of a new crack .

According to the invention of claims 1 to 12, in the case where a substrate having a pattern is divided by crack extension processing, when a crack can be inclined in processing in a direction orthogonal to the orientation flat, It is suitably suppressed that the unit patterns constituting the individual device chips formed on the patterned substrate are broken at the time of discretization. As a result, the yield of the device chip obtained by dividing the substrate having the pattern is improved.

1 is a schematic view schematically showing a configuration of a laser machining apparatus 100 used for splitting a workpiece.
Fig. 2 is a view for explaining an irradiation mode of the laser beam LB in the crack extension processing.
Fig. 3 is a schematic plan view and partial enlarged view of a patterned substrate W. Fig.
4 is a view showing the shape of a crack extension on a cross section perpendicular to the Y direction of the substrate W having the pattern when the laser light LB is irradiated along the line to be processed PL.
5 is a schematic sectional view showing the shape of a crack extension in the thickness direction of the substrate W having the pattern when the crack extension processing is performed by offsetting the irradiation position IP of the laser light LB.
6 is a diagram showing the flow of the offset condition setting process according to the first embodiment.
Fig. 7 is a diagram illustrating an irradiation position IP1 of the laser beam LB in the dashed line.
Fig. 8 is a diagram for explaining a method of determining the coordinate X1 based on the picked-up image IM1 of the patterned substrate W. Fig.
Fig. 9 is a diagram for explaining a method of determining a coordinate X2 based on a picked-up image IM2 of a patterned substrate W. Fig.
10 is a diagram showing a flow of an offset condition setting process according to the second embodiment.
11 is a diagram showing a flow of an offset condition setting process according to the third embodiment.
12 is a diagram exemplifying a profile PF3 created based on the captured image IM3 of the substrate W having the pattern obtained in step STP13 and the rectangular area RE3 included in the captured image IM3 .
13 is a profile PF3 exemplified for explanation of steps STP25 and STP26.
14 is an approximate straight line profile created based on the profile PF3 shown in Fig.

(Mode for carrying out the invention)

<Laser Processing Apparatus>

1 is a schematic view schematically showing a configuration of a laser machining apparatus 100 used for dividing a workpiece, which is applicable to an embodiment of the present invention. The laser machining apparatus 100 includes a controller 1 for controlling various operations (observation, alignment, machining, and the like) in the apparatus, a controller 1 for controlling the machining of the workpiece 10 A stage 4 and an irradiation optical system 5 for irradiating the workpiece 10 with the laser light LB emitted from the laser light source SL.

The stage 4 is mainly composed of an optically transparent member such as quartz. The stage 4 is capable of sucking and fixing the workpiece 10 placed on its upper surface by a suction means 11 such as a suction pump. The stage 4 is movable in the horizontal direction by the moving mechanism 4m. 1, after the support sheet 10a having adhesiveness is adhered to the workpiece 10, the side of the support sheet 10a is set as a workpiece surface to be processed, Is placed on the stage 4, but an embodiment using the support sheet 10a is not essential.

The moving mechanism 4m moves the stage 4 in a predetermined XY 2 -axis direction within a horizontal plane by the action of driving means (not shown). Thus, movement of the observation position and movement of the laser light irradiation position are realized. Further, with regard to the moving mechanism 4m, it is more preferable to perform the rotation (? Rotation) operation in the horizontal plane around the predetermined rotation axis independently of the horizontal drive in order to perform alignment and the like .

The irradiation optical system 5 includes a laser light source SL, a half mirror 51 provided in a lens barrel (not shown), and a condenser lens 52.

In the laser processing apparatus 100, after the laser light LB emitted from the laser light source SL is roughly reflected by the half mirror 51, the laser light LB is focused on the condenser lens 52 The workpiece 10 is focused so as to focus on the workpiece 10 placed on the stage 4 and irradiated to the workpiece 10. In this embodiment, by moving the stage 4 while irradiating the laser beam LB, the workpiece 10 can be machined along a predetermined line to be machined. In other words, the laser machining apparatus 100 is a device that performs machining by relatively scanning the laser beam LB with respect to the workpiece 10.

As the laser light source SL, it is preferable to use an Nd: YAG laser. As the laser light source SL, those having a wavelength of 500 nm to 1600 nm are used. Further, in order to realize the processing to the above-described processing pattern, the pulse width of the laser beam LB needs to be about 1 psec to 50 psec. It is preferable that the repetition frequency R is about 10 kHz to 200 kHz, and the irradiation energy (pulse energy) of the laser light is about 0.1 μJ to 50 μJ.

In the laser processing apparatus 100, it is also possible to irradiate the laser beam LB in a defocus state in which the focussing position is intentionally shifted from the surface of the workpiece 10, if necessary, during the processing It is becoming. In the present embodiment, it is desirable to set the defocus value (displacement of the focussing position in the direction from the surface of the workpiece 10 to the inside thereof) to a range of 0 占 퐉 to 30 占 퐉.

The laser processing apparatus 100 further includes an upper observation optical system 6 for observing and imaging the workpiece 10 from above and an upper observation optical system 6 for observing the workpiece 10 from the stage 4 And an upper illumination system 7 for irradiating illumination light from above. A lower illumination system 8 for irradiating the workpiece 10 with illumination light from below the stage 4 is provided below the stage 4.

The upper observation optical system 6 includes a CCD camera 6a provided above the half mirror 51 (above the mirror barrel) and a monitor 6b connected to the CCD camera 6a. The upper illumination system 7 includes an upper illumination light source S1 and a half mirror 71. [

The upper observation optical system 6 and the upper illumination system 7 are coaxial with the irradiation optical system 5. More specifically, the half mirror 51 and the condenser lens 52 of the irradiation optical system 5 are shared with the upper observation optical system 6 and the upper illumination system 7. Thus, the upper illumination light L1 emitted from the upper illumination light source S1 is reflected by the half mirror 71 provided in the barrel (not shown) and transmitted through the half mirror 51 constituting the irradiation optical system 5 The workpiece 10 is focused by the condenser lens 52 and irradiated onto the workpiece 10. In the upper observation optical system 6, when the upper illuminating light L1 is irradiated, the name of the workpiece 10 that has passed through the condenser lens 52, the half mirror 51, and the half mirror 71 Bright) field of view.

The lower illumination system 8 includes a lower illumination light source S2, a half mirror 81, and a condenser lens 82. [ That is, in the laser processing apparatus 100, the lower illumination light L2 emitted from the lower illumination light source S2, reflected by the half mirror 81, and condensed by the condenser lens 82 is reflected by the stage 4, So that the workpiece 10 can be irradiated. For example, by using the lower illumination system 8, it is possible to observe the transmitted light in the upper observation optical system 6 while irradiating the workpiece 10 with the lower illumination light L2.

Further, as shown in Fig. 1, the laser processing apparatus 100 may be provided with a lower observation optical system 16 for observing and imaging the workpiece 10 from below. The lower observation optical system 16 includes a CCD camera 16a provided below the half mirror 81 and a monitor 16b connected to the CCD camera 16a. In the lower observation optical system 16, for example, the transmitted light can be observed in a state in which the upper illumination light L1 is irradiated to the work 10. [

The controller 1 includes a control section 2 for controlling the operation of each section of the apparatus to realize the processing of the workpiece 10 in the embodiment to be described later and a program for controlling the operation of the laser processing apparatus 100 3p) and a storage unit 3 for storing various kinds of data to be referred to at the time of processing.

The control unit 2 is realized by a general-purpose computer such as a personal computer or a microcomputer. By reading the program 3p stored in the storage unit 3 and executing the program 3p, The component is realized as a functional component of the control unit 2. [

The storage unit 3 is realized by a storage medium such as a ROM, a RAM, and a hard disk. The storage unit 3 may be realized by an element of a computer that realizes the control unit 2, or may be an embodiment that is formed separately from the computer, such as a hard disk.

The storage section 3 stores not only the program 3p but also individual information (e.g., material, crystal orientation, shape (size, thickness), etc.) of the work 10 to be machined, ) And the conditions for the individual parameters of the laser beam and the driving conditions of the stage 4 (or the setting of the driving conditions of the stage 4) according to the embodiment of laser machining in the individual machining modes And the machining mode setting data D2 describing the machining mode setting data D2. The storage section 3 stores irradiation positions to be referred to when it is necessary to offset the irradiation position of the laser light LB by a predetermined distance with respect to the processing position described in the workpiece data D1 for reasons to be described later The offset data D3 is also appropriately stored.

The control unit 2 includes a drive control unit 21 for controlling the operation of various driving parts related to the processing such as driving of the stage 4 by the moving mechanism 4m and focusing operation of the condenser lens 52 An image pickup control section 22 for controlling the observation and image pickup of the workpiece 10 by the upper observation optical system 6 and the lower observation optical system 16 and an image pickup control section 22 for controlling the laser light LB from the laser light source SL An attraction control section 24 for controlling the attraction and fixing operation of the workpiece 10 to the stage 4 by the suction means 11, (25) for executing processing to a processing target position in accordance with the machining mode setting data (D2) and processing mode setting data (D2), and processing for setting a condition according to the offset of the irradiation position of the laser beam (LB) And an offset setting unit 26 for setting an offset.

In the laser machining apparatus 100 including the controller 1 configured as described above, the operator instructs the machining execution instruction in the predetermined machining mode for the machining position described in the workpiece data D1 The machining processing unit 25 acquires the workpiece data D1 and acquires the condition corresponding to the selected machining mode from the machining mode setting data D2 and controls the drive And controls operations of corresponding units through the control unit 21 and the irradiation control unit 23 and the like. For example, the irradiation control section 23 realizes the wavelength or the output of the laser light LB emitted from the laser light source SL, the repetition frequency of the pulse, and the adjustment of the pulse width. Thus, machining in the specified machining mode is realized at the machining position to be machined.

However, in the laser machining apparatus 100 according to the present embodiment, for example, the workpiece 10 is a substrate W having a pattern (see Figs. 3 and 4) The irradiation position of the laser beam LB can be offset as necessary before laser processing according to the above-described embodiment. The details of the offset of the irradiation position of the laser light LB will be described later.

Preferably, the laser machining apparatus 100 further includes a laser machining apparatus 100 for performing machining in accordance with a machining process menu that is available to the operator in the controller 1 under the action of the machining process unit 25, So that the machining mode can be selected. In this case, the processing menu is preferably provided in the GUI.

With the above configuration, the laser machining apparatus 100 can appropriately perform various types of laser machining.

<Principle of crack extension processing>

Next, crack extension processing, which is one of the processing methods that can be realized in the laser processing apparatus 100, will be described. Fig. 2 is a view for explaining an irradiation mode of the laser light LB in the crack extension processing. More specifically, Fig. 2 shows the relationship between the repetition frequency R (kHz) of the laser beam LB at the time of crack extension processing and the moving speed V (kHz) of the stage on which the workpiece 10 is placed upon irradiation of the laser beam LB (Mm / sec) and the beam spot center distance? (占 퐉) of the laser beam LB. In the following description, it is assumed that the outgoing source of the laser beam LB is fixed and the stage 4 on which the workpiece 10 is placed is moved on the premise that the above-described laser machining apparatus 100 is used, The relative scanning of the laser beam LB with respect to the workpiece 10 is realized but even in the embodiment in which the source of the laser beam LB is moved while the workpiece 10 is stationary, Are equally feasible.

As shown in Fig. 2, when the repetition frequency of the laser light LB is R (kHz), one laser pulse (also referred to as unit pulse light) is emitted from the laser light source every 1 / R (msec). When the stage 4 on which the workpiece 10 is placed moves at a speed V (mm / sec), while the next laser pulse is emitted after a certain laser pulse is emitted, (탆) of the beam spot center position of a laser pulse and the beam center position of the next laser pulse, i.e., the beam spot center distance? (占 퐉) Δ = V / R.

At this point, the beam diameter (beam waist diameter, also referred to as spot size) Db of the laser light LB on the surface of the workpiece 10 and the beam spot center distance?

?> Db (1)

, The individual laser pulses do not overlap at the time of scanning of the laser beam.

In addition, when the irradiation time of the unit pulse light, that is, the pulse width is set to be very short, at a position to be irradiated with each unit pulse light, a substance which is narrower than the spot size of the laser light LB, Is obtained by obtaining the kinetic energy from the irradiated laser beam, it is scattered or deteriorated in the direction perpendicular to the surface to be irradiated, while the impact or stress generated by the irradiation of the unit pulse light including the reaction force accompanying the scattering A phenomenon that acts around the irradiated position occurs.

By using these, it is possible to sequentially and discretely irradiate laser pulses (unit pulse light) sequentially emitted from the laser light source along the line to be processed. Minute cracks are successively formed on the workpiece, cracks are continuously formed between the individual workpieces, and further cracks are also stretched in the thickness direction of the workpiece. As described above, the cracks formed by the crack extension processing serve as a starting point of the division when the work 10 is divided. In the case where the laser beam LB is irradiated in a defocus state below a predetermined (not zero) defocus value, deterioration occurs in the vicinity of the focal point position, and the region where such deterioration occurs is the above- It becomes a trace.

The work 10 can be divided by performing, for example, a breaking process in which a crack formed by the crack extension processing is extended to the opposite surface of the substrate W using a known braking device It becomes. In addition, when the work 10 is completely divided in the thickness direction by the expansion of the crack, the above-mentioned breaking process is unnecessary. However, even if some cracks reach the opposite surface, ) Is rarely complete in two minutes, it is common to involve a braking process.

The brake process is performed, for example, in such a manner that the work 10 is placed on the other side in a state in which the main surface on the side where the machining marks are formed is in the lower side and both sides of the line to be divided are supported by the two lower brake bars And lowering the upper brake bar toward the brake position just above the scheduled line to be divided.

In addition, if the beam spot center distance? Corresponding to the pitch of the machining trace is too large, the brake characteristic deteriorates and the brake along the expected machining line can not be realized. It is necessary to determine the machining conditions in consideration of this point in the crack extension processing.

Taking the above points into consideration, the conditions suitable for performing the crack expansion processing for forming the crack serving as the division starting point in the work 10 are approximately as follows. The specific conditions may be appropriately selected depending on the material and the thickness of the work 10.

Pulse width?: 1 psec or more and 50 psec or less;

Beam diameter Db: about 1 탆 to about 10 탆;

Stage moving speed V: 50 mm / sec to 3000 mm / sec;

Pulse repetition frequency R: 10 kHz or more and 200 kHz or less;

Pulse energy E: 0.1 占 ~ to 50 占..

&Lt; Patterned substrate &gt;

Next, a substrate W having a pattern as an example of the workpiece 10 will be described. 3 is a schematic plan view and partial enlarged view of a substrate W having a pattern.

The substrate W having a pattern is formed by laminating predetermined device patterns on one main surface of a single crystal substrate (a wafer or a mother substrate W1 (see Fig. 4) such as sapphire . The device pattern has a configuration in which a plurality of unit patterns UP, each of which constitutes one device chip, are repeatedly arranged two-dimensionally after being separated from one another. For example, an optical device such as an LED device or an electronic device The unit pattern UP is repeated two-dimensionally.

Although the substrate W having the pattern has a substantially circular shape in plan view, a part of the outer periphery is provided with a straight orientation flat OF. Hereinafter, the extending direction of the orientation flat OF in the plane of the patterned substrate W is referred to as the X direction, and the direction orthogonal to the X direction is referred to as the Y direction.

As the single crystal substrate W1, those having a thickness of 70 mu m to 200 mu m are used. A sapphire single crystal having a thickness of 100 mu m is preferably used. Further, the device pattern is usually formed to have a thickness of about several micrometers. The device pattern may have irregularities.

For example, in the case of a substrate W having a pattern for manufacturing LED chips, a plurality of thin film layers including a light emitting layer and a group III nitride semiconductor including GaN (gallium nitride) are epitaxially formed on a sapphire single crystal, And an electrode pattern constituting a current-carrying electrode in the LED element (LED chip) is formed on the thin film layer.

In the formation of the patterned substrate W, the plane direction of the crystal plane of the c-plane, the a-plane, or the like is defined as the direction normal to the plane of the principal plane A so-called off-angle-imparted substrate (also referred to as an off-substrate) may be used.

The narrow area, which is the boundary of each unit pattern UP, is referred to as a street ST. The street ST is irradiated along the street ST in a later-described embodiment as a division target position of the substrate W having a pattern so that the substrate W having the pattern is divided into individual device chips do. The street ST is usually set to have a width of several tens of micrometers and to form a lattice shape when the device pattern is viewed in a plane. However, the single crystal substrate W1 need not be exposed in the portion of the street ST, and the thin film layer constituting the device pattern may be formed continuously at the position of the street ST.

<Crack Expansion and Offset of Machining Position in a Patterned Substrate>

Hereinafter, a case will be considered in which crack extension processing is performed along a planned processing line PL defined at the center of the street ST in order to divide the substrate W having the above-described pattern along the street ST.

In the present embodiment, in the case of performing crack extension processing in this embodiment, the side of the substrate W on which the device pattern is not formed, that is, the side of the substrate W on which the single crystal substrate W1 is exposed It is assumed that the laser beam LB is irradiated toward the main surface Wa (see Fig. 4). That is, the main surface Wb (see FIG. 4) on the side where the device pattern is formed is placed on the stage 4 of the laser processing apparatus 100 and fixed with the surface to be irradiated with laser light LB . Strictly speaking, although there are irregularities on the surface of the device pattern, since the irregularities are sufficiently smaller than the thickness of the entire substrate W having the pattern, the device pattern of the substrate W having the pattern is substantially It is regarded that a flat main surface is provided on the side where it is formed. Alternatively, the main surface of the single crystal substrate W1 on which the device pattern is formed may be regarded as the main surface Wb of the substrate W having the pattern.

This is because the irradiation of the laser beam is not necessary in the implementation of the crack extension processing, but in the case where the width of the street ST is small or the thin film layer is formed on the portion of the street ST, In order to reduce the influence to be imparted to the image, or to achieve more reliable division. 3, the unit pattern UP or the street ST is indicated by a broken line because the main surface Wa on which the single crystal substrate is exposed is the surface to be irradiated with the laser beam and the main surface Wb on which the device pattern is formed, It is pointing toward the opposite side.

It is also assumed that the crack extension processing is performed in a defocus state in which a predetermined (not zero) defocus value is given to the laser beam LB. The defocus value is set to be sufficiently smaller than the thickness of the substrate W having the pattern.

4 is a view showing a state in which the laser processing apparatus 100 sets the irradiation condition for generating the crack extension and then sets the irradiation condition to be set at the center position of the street ST extending in the Y direction orthogonal to the orientation flat OF, Sectional view showing the shape of the crack extension in the thickness direction of the substrate W having the pattern when the laser beam LB is irradiated along the laser beam PL to perform crack extension processing. Hereinafter, the main surface Wa of the patterned substrate W is also referred to as the surface of the substrate W having the pattern, and the main surface Wb of the patterned substrate W is referred to as the substrate W ) May be referred to as the back side.

In this case, machining marks M are discretely formed along the Y-axis direction at positions at a distance of several mu m to 30 mu m from the main surface Wa in the thickness direction of the substrate W having the pattern, The cracks are stretched between the machining marks M and the cracks CR1 and cracks CR1 and CR2 are radiated from the machining trace M toward the upper side (main surface Wa side) and downward (toward the main surface Wb) (CR2).

It is to be noted that these cracks CR1 and CR2 are formed on the surface P1 extending in the vertical direction or downward direction of the processing trace M, that is, extending in the thickness direction of the substrate W, But is inclined with respect to the plane P1 and deviates from the plane P1 as the distance from the processing trace M increases. In addition, the directions in which the cracks CR1 and CR2 deviate from the plane P1 in the X direction are opposite to each other.

In the case where the cracks CR1 and CR2 are inclined in this manner, the ends T of the cracks CR2 are stretched by a subsequent breaking process, as shown in Fig. 4, depending on the degree of inclination , It may happen that the area exceeds the range of the street ST and is extended to the part of the unit pattern UP constituting the device chip. When the braking is performed starting from the point where the cracks CR1 and CR2 are extended as described above, the unit pattern UP is broken and the device chip becomes defective. Further, it is known empirically that such a crack inclination occurs in the same processing position in the same direction as long as the processing is performed in the same direction in the substrate W having the same pattern. If the slope of the cracks in the thickness direction occurs in each street ST and further, the breakage of the unit pattern UP occurs, the number of device chips (yield) which is a good product is lowered Abandoned.

In order to avoid the occurrence of such a problem, in the present embodiment, the irradiating position of the laser light LB is set at the machining position (machining position) so that the end T of the crack CR2 remains within the range of the street ST From the set position of the line PL.

5 is a graph showing the relationship between the irradiation position IP of the laser light LB and the position of the pattern when the crack extension processing is performed by offsetting the irradiation position IP of the laser light LB in the -X direction indicated by the arrow AR1 from the scheduled processing line PL shown in Fig. Sectional view showing the shape of a crack extension in the thickness direction of the substrate W having a predetermined thickness. As shown in Fig. 5, when the irradiation position IP of the laser beam LB is offset, destruction of the unit pattern UP is avoided.

5, the end T2 of the crack CR2 is located immediately below the line to be machined PL, but this is not an essential embodiment, and the end T2 is within the range of the street ST It is good to stay.

5, the end T1 of the crack CR1 extending to the side of the main surface Wa on which the unit pattern UP does not exist does not remain within the range of the street ST, Is not a problem unless it is a significant leaning that affects the. For example, as long as the shape of the device chip stays within a predetermined allowable range, a slope such as the crack CR1 shown in Fig. 5 is allowed.

The inclination of the crack as described above is a phenomenon that occurs only when a crack extension processing is performed along the Y direction orthogonal to the orientation flat OF with respect to the substrate W having the pattern and the orientation flat In the case where crack extension processing is performed along the X direction which is parallel to the direction of the X axis. That is, when the crack extension processing is performed along the X direction, the extension of the crack in the thickness direction of the substrate W with the pattern is generated vertically upward and downward from the processing trace.

<Setting of Offset Condition>

(First Embodiment)

As described above, in the case where the substrate W having the pattern is subjected to the crack extension processing to be separated, in the processing in the Y direction orthogonal to the orientation flat OF, the position of the irradiation position of the laser beam LB An offset may be required. 4 and 5, the crack CR1 is inclined in the -X direction and the crack CR2 is inclined in the + X direction. However, this is only an example, The direction of extension of the laser beam LB can be changed by the substrate W having the individual patterns and the direction in which the inclination of the cracks occurs in the substrate W having the individual patterns and the direction of the laser beam LB And it can not be known unless the crack extension processing is performed. If at least the direction of the inclination is not known, it is impossible to actually offset the irradiation position.

In addition, in the process of mass production of a device chip, it is required to set conditions for offset automatically and as quickly as possible from the viewpoint of productivity improvement.

6 is a diagram showing the flow of the offset condition setting process performed in the laser machining apparatus 100 according to the present embodiment based on the above points. The setting process of the offset condition in the present embodiment is roughly performed by actually performing crack extension processing on a part of the substrate W having a pattern to be separated and then changing the direction of inclination of the generated crack by image processing A predetermined offset amount (distance) is given in the specified direction. The setting process of the offset condition is carried out in such a manner that the offset setting section 26 provided in the controller 1 of the laser processing apparatus 100 operates the respective sections of the apparatus in accordance with the program 3p stored in the storage section 3 And performing necessary arithmetic processing and the like.

The substrate W having the pattern is fixed on the stage 4 of the laser machining apparatus 100 and fixed in the X direction and the Y direction in advance before the setting process, Axis direction, which is the direction of movement of the base plate 4m. In addition to the technique disclosed in Patent Document 1, a well-known technique can be appropriately applied to the alignment process. It is assumed that the workpiece data D1 describes the individual information of the substrate W having the pattern to be machined.

First, a position (an irradiation position of the laser light LB) for performing an offset setting crack extension processing is determined (step STP1), and a laser light LB is applied to the position to perform crack extension processing Step STP2). Hereinafter, such crack extension processing for setting the offset will be referred to as "temporary working".

It is preferable that such a machining is performed at a position where the machining result does not affect the number of extraction of the device chip. For example, it is preferable to carry out the outer edge position where the unit pattern UP, which becomes the device chip, is not formed in the substrate W having the pattern. Fig. 7 is a diagram illustrating the irradiation position IP1 of the laser light LB in the dashed line in consideration of this point. 7, the vicinity of the outer edge (X direction side) of the substrate W having a pattern more than the street ST (ST1) having the position coordinate in the X direction is the most negative, (IP1) is set. 7, the irradiation position IP1 is shown extending over two outer peripheral edge positions of the patterned substrate W. However, the laser light LB may be irradiated over the entire range between both outer peripheral edge positions You do not have to.

The method of setting the specific irradiation position IP1 is not particularly limited. For example, it may be an embodiment based on data relating to the shape of the substrate W having the pattern imparted in advance, or the position of the street ST (ST1) may be specified by image processing, The present invention is not limited thereto.

When the processing for the irradiation position IP1 is finished, the substrate W having the pattern is irradiated with the transmitted illumination light from the side of the main surface Wb by the lower illumination light source S2, (Step STP3) in a state in which the focal position (height) of the substrate W is aligned with the main surface Wa, which is the surface of the substrate W having the pattern in this case. Then, a predetermined processing is performed on the obtained picked-up image to determine a coordinate X1 that can be regarded as a typical coordinate position in the X direction of the end T1 of the main surface Wa of the crack CR1 (Step STP4).

Fig. 8 is a diagram for explaining a method of determining the coordinate X1 based on the picked-up image IM1 of the substrate W having the pattern obtained in step STP3.

More specifically, FIG. 8A shows a portion in the vicinity of the irradiation position IP1 of the laser beam LB in the captured image IM1 obtained in step STP3. In the photographed image IM1, the processing marks M are observed as a minute array (dotted line) or almost continuous line extending in the Y direction. Further, the crack CR1 stretched from the processing trace M toward the side of the main surface Wa is observed with a relatively higher contrast (higher pixel value, more specifically, blacker) than the processing trace M is observed. It is to be noted that the crack CR1 is relatively stronger in contrast to the processing mark M than the processing mark M is in the vicinity of the focus position of the CCD camera 6a as compared with the processing mark M Because.

The determination of the coordinate X1 based on the captured image IM1 obtained in this manner is carried out by determining the coordinates X1 on the basis of the captured image IM1, A predetermined rectangular area RE1 is set and a profile obtained by integrating the pixel value (color density value) at the same position of the X coordinate in the rectangular area RE1 along the Y direction is created. 8 (b) is a profile PF1 obtained by this integration processing, with respect to the captured image IM1 shown in Fig. 8 (a).

As described above, since the picked-up image IM1 shown in Fig. 8A is obtained by focusing on the main surface Wa, the position where a large amount of cracks CR1 are present, and furthermore, the crack CR1 It is considered that the closer to the main surface Wa is, the higher the pixel value is in the profile PF1 shown in Fig. 8 (b). Therefore, in the present embodiment, the coordinate X1 at which the pixel value becomes maximum in the profile PF1 is regarded as the coordinate position in the X direction of the end T1 of the crack CR1.

When the coordinate X1 is determined in this manner, the substrate W having the pattern by the lower illumination light source S2 is irradiated from the side of the main surface Wb with respect to the substrate W in the same manner as when the captured image IM1 is picked up In a state where the focus position (height) of the CCD camera 6a is adjusted to the depth position of the processing mark M, that is, the focal position of the laser light LB at the time of the crack extension processing, And picks up the processing position (step STP5). Then, by performing predetermined processing on the obtained picked-up image, a coordinate X2 that can be regarded as a typical coordinate position in the X direction of the machining trace M is determined (step STP6).

Fig. 9 is a diagram for explaining a method of determining the coordinate X2 based on the picked-up image IM2 of the substrate W having the pattern obtained in step STP5.

More specifically, Fig. 9 (a) shows a portion in the vicinity of the irradiation position IP1 of the laser light LB in the captured image IM2 obtained in step STP5. The machining trace M is observed as a fine line or almost continuous line extending in the Y direction in the picked-up image IM2 similarly to the picked-up image IM1 shown in Fig. 8 (a) A crack CR1 that is extended from the processing mark M toward the side of the main surface Wa is also observed. However, since the focus position at the time of image capture is set at the depth position of the machining trace M, the contrast of the machining trace M is relatively stronger in the picked-up image IM2 than in the picked- do.

The determination of the coordinate X2 based on the captured image IM2 thus obtained is performed in the same manner as in the method of determining the end T1 of the crack CR1 in step STP4, A predetermined rectangular area RE2 including an image of the processing trace M and the crack CR1 is set and the pixel value at the same position in the rectangular area RE2 Value) along the Y-direction. 9 (b) is a profile PF2 obtained by such an integration process, with respect to the captured image IM2 shown in Fig. 9 (a). The rectangular area RE2 and the rectangular area RE1 may be set to the same size or different depending on the position of the processing trace M and the crack CR1 in each captured image.

As described above, since the picked-up image IM2 shown in Fig. 9 (A) is obtained by focusing on the depth position of the machining trace M, the closer to the machining trace M, It is considered that the pixel value is high in the profile PF2 shown in Fig. Therefore, in the present embodiment, the coordinate X2 at which the pixel value becomes the maximum in the profile PF2 is regarded as the coordinate position in the X direction of the machining trace M.

The order of execution of the processing shown as steps STP3 to STP6 may be changed as appropriate, or may be suitably performed in parallel. For example, after the imaging processing in steps STP3 and STP5 is continuously performed, the processing for specifying the coordinates (X1, X2) in steps STP4 and STP6 may be sequentially performed, and the processing in step STP3 The image pick-up processing in step STP5 may be performed in parallel with the image pick-up processing while the processing for specifying the coordinates X1 in step STP4 is being performed.

If the values of the coordinates X1 and X2 are determined in the above embodiment, then the difference value? X = X2-X1 of these coordinate values is calculated and the direction (offset direction) in which the offset is to be performed is specified based on the result (Step STP7).

Specifically, there is the following relationship between? X and the offset direction.

? X> 0? End T1 reaches + X direction than machining mark M → offset in -X direction;

? X <0? End T1 reaches offset in -X direction than processing mark M in offset + X direction;

ΔX = 0 → End T1 reaches directly above the machining trace (M) → No offset required.

In the cases shown in Figs. 8 and 9, since? X &lt; 0, it is specified to be offset in the + X direction.

When the offset direction is thus specified, an offset amount with respect to the specified offset direction is determined based on the workpiece data D1 stored in the storage unit 3 and the irradiation position offset data D3 STP8).

As described above, in the workpiece data D1, pieces of individual information (crystal orientation, thickness, etc.) of the substrate W having a pattern to be actually processed (i.e., subjected to crack extension and machining for offset setting) are described . On the other hand, in the irradiation position offset data D3, a technique capable of setting the offset amount in accordance with the individual information of the substrate W having the pattern is performed in advance. The offset setting unit 26 acquires the individual information of the substrate W having the pattern from the workpiece data D1 and refers to the irradiation position offset data D3 to determine an offset amount according to the individual information .

The offset amount determined from the description content of the irradiation position offset data D3 is a value obtained by offsetting the irradiation position of the laser light LB with respect to the processing position by the value, CR2 in the unit pattern UP is avoided. For example, as long as the thickness of the substrate W having the pattern tends to be larger as the thickness of the substrate W tends to be larger, the irradiation position offset data D3 is larger A countermeasure is taken such that the technique is performed so that the offset amount is set.

The format of the irradiation position offset data D3 is not particularly limited. For example, the irradiation position offset data D3 may be prepared as a table describing the offset amount to be set for each material type or thickness range of the substrate W having the pattern, or alternatively, The present invention is not limited to this.

As is clear from the above-described determination method, since the determination of the offset amount can be performed irrespective of the specification of the offset direction, which is performed from step STP1 to step STP7, it is not always necessary to determine after determining the offset direction Alternatively, the embodiment may be performed before the specification of the offset direction, or in parallel with the specification of the offset direction.

When the determination of the offset direction in step STP7 and the determination of the offset amount in step STP8 are made, the offset setting process is terminated. Subsequently, based on the determined offset direction and offset amount, ) Is subjected to a crack extension processing process. As a result, the dislocation of the patterned substrate W in which the destruction of the unit pattern UP due to the expansion of the crack is appropriately suppressed is realized.

It is also possible in principle to set the offset amount in accordance with the value of DELTA X calculated in step STP7 or to set DELTA X itself as the offset amount. However, by adopting such an embodiment, It does not improve. This is because the coordinates (X1 and X2) determined in the above-described embodiment are not necessarily a value that accurately represents the actual position of the end T1 of the crack CR1 or the machining trace M It can not be said that the difference value DELTA X is a value which is obtained for convenience in determining the offset direction for the most part so that an appropriate offset amount is always given in all the processing of the substrate W having the pattern I can not.

(Second Embodiment)

The method of setting the offset condition in the laser machining apparatus 100 is not limited to the first embodiment described above. 10 is a diagram showing a flow of an offset condition setting process according to the second embodiment. The setting process according to the second embodiment shown in Fig. 10 is different from the first embodiment in that steps STP13 and STP14 are performed in place of steps STP3 and STP4 of the setting process in the first embodiment shown in Fig. 6, , And the coordinate value used for calculation of the difference value in step STP7 is different from the setting process according to the first embodiment, the setting process is the same as the setting process according to the first embodiment.

Specifically, in the second embodiment, after the processing is performed by the steps STP1 to STP2, the light from the side of the main surface Wb to the substrate W having the pattern by the lower illumination light source S2 In the state in which the illumination is applied, the focal position (height) of the CCD camera 6a is matched to the main surface Wb, which is the back surface of the substrate W having the pattern in this case, (Step STP13). Then, by performing the same image processing as the image processing for determining the termination T1 of the crack CR1 described with reference to Fig. 8 on the obtained captured image, the termination at the main surface Wb of the crack CR2 (Step STP14), which can be regarded as a typical coordinate position in the X direction of the coordinate system T2. Concretely, the same profile as the profile PF1 in Fig. 8B is created, and the coordinate X3 at which the pixel value becomes the maximum is considered as the position of the end T2 of the crack CR2 do.

Subsequently, the processing of steps STP5 to STP6 is performed to obtain the coordinate (X2). Then, in step STP7, ΔX = X2-X3 is calculated and the direction (offset direction) (Step STP7).

Specifically, there is the following relationship between? X and the offset direction.

? X> 0? End T2 reaches the -X direction than the machining trace (M)? Offset in the + X direction;

? X <0? End T2 reaches + X direction than machining mark M? Offset in -X direction;

ΔX = 0 → End (T2) reaches just below the machining trace (M) → No offset required.

The offset amount may be set in the same manner as in the first embodiment.

In the case of the second embodiment, similarly to the first embodiment, when the determination of the offset direction in step STP7 and the determination of the offset amount in step STP8 are made, the offset setting process is ended, Based on the determined offset direction and offset amount, a crack extension processing process is performed to separate the substrate W having the pattern. As a result, the dislocation of the patterned substrate W in which the destruction of the unit pattern UP due to the expansion of the crack is appropriately suppressed is realized.

(Third Embodiment)

Although both the first and second embodiments described above are common in that the offset direction is specified based on the difference value of the coordinate values, the method of setting the offset condition in the laser machining apparatus 100 is not limited to this . 11 is a diagram showing a flow of an offset condition setting process according to the third embodiment.

The setting process according to the third embodiment shown in Fig. 11 is the same as the setting process in the step STP13 of the setting process according to the second embodiment shown in Fig. 10 except that the area ST is orthogonal to the street ST, Is the same as the setting process according to the second embodiment except that the setting process according to the second embodiment differs from the setting process according to the second embodiment in that steps STP24 to STP27 are performed in place of the following steps STP5 to STP7.

Specifically, in the third embodiment, first, after the step STP1 to step STP2 are processed, the focus position (height) of the CCD camera 6a is set to the pattern in this case In the state of being aligned with the main surface Wb, which is the back surface of the substrate W, on which the processing is performed. However, as described above, at the time of image pickup, a portion where the street ST crosses orthogonally is picked up.

12 is a diagram showing a profile PF3 created based on the rectangular area RE3 included in the captured image IM3 and the captured image IM3 of the substrate W having the pattern obtained in step STP13 to be.

In the case of the third embodiment, if a captured image IM3 as shown in Fig. 12 (a) is obtained by the imaging in step STP13, a street ST extended in the Y direction in the captured image IM3 And a profile PF3 obtained by integrating the pixel value (color density value) at the same position of the X coordinate in the rectangular area RE3 along the Y direction is created Step STP24). The obtained profile PF3 is shown in Fig. 12 (b). However, in order to simplify the process of the rear stage, a moving average value such as a 5-point moving average is used for this profile PF3 instead of using the raw data of the integrated value as it is.

In the profiles PF1 and PF2 shown in Figs. 8 (b) and 9 (b), each profile is shown to have a higher value as the brightness decreases (darker). In Fig. 12 (b) On the contrary, the profile PF3 is shown so as to have a higher value as the brightness is higher (bright).

After the profile PF3 is obtained, the slope? (X) of the approximate straight line is calculated for each of three neighboring points in the profile PF3 and the value of the slope? (X) And a plotted profile (approximate straight line slope profile) is created (step STP25). Based on the obtained approximate straight line slope profile, the slope of two approximate straight lines sandwiching the minimum value in the profile PF3 is calculated (step STP26).

Fig. 13 is a profile PF3 exemplified for the explanation of steps STP25 and STP26. In the profile PF3 shown in Fig. 13, it is assumed that the pixel value takes a minimum value (extremum value) at X = Xmin.

14 is an approximate straight line profile created based on the profile PF3 shown in Fig. The approximate straight line slope profile in Fig. 14 roughly shows the change in slope of the profile PF3. 14, the profile PF3 increases, while in the range where the value of? (X) is negative in FIG. 14, the profile PF3 decreases , And the profile PF3 is almost constant in a range in which the value of? (X) is close to 0 in Fig.

Now, in the profile PF3 illustrated in Fig. 13, the pixel value that has been substantially constant as the value of X becomes monotonously decreased as the value of X becomes larger, becomes minimum at X = Xmin, and when the value of X becomes larger, . Therefore, in the approximate straight line slope profile of Fig. 14, the value of X (X = XU1) where the value of (absolute value of) (X) (X) becomes larger than the predetermined threshold value A in a range larger than X = XU1 and X (X = XU2) where the value of (absolute value of) X (X) becomes smaller than the predetermined threshold value B is obtained, the interval XU1 to XU2 ) Is roughly the section in which the pixel value increases in the profile PF3 shown in Fig. Therefore, when the slope? 1 of the approximate straight line between X = XU1 and X = XU2 in the profile PF3 is obtained, this slope indicates the slope of the section in which the pixel value increases in the profile PF3 do.

(X = XL1) where the value of the absolute value of? (X) becomes larger than the predetermined threshold value A in a range smaller than X = Xmin in the approximate straight line slope profile of FIG. 14, (X = XL2) in which the value of the absolute value of the absolute value X is smaller than the predetermined threshold value B (X = XL2), the sections XL2 to XL1 having the former as the maximum value and the latter as the minimum value, Is a section in which the pixel value decreases in the profile PF3 shown in Fig. Therefore, when the slope? 2 of the approximate straight line between X = XL2 and X = XL1 in the profile PF3 is obtained, this slope is obtained by dividing the slope of the section in which the pixel value decreases in the profile PF3 .

In this way, if two slopes? 1 and? 2 of approximate straight lines sandwiching X = Xmin are obtained, the offset direction is specified from the difference between the two slopes (strictly speaking, the absolute value difference) (step STP27).

Specifically, from the correlation between the slant direction of the crack and??, Which is empirically specified between the difference ?? = |? 2 | - |? 1 | between the absolute values of the slopes? 1 and? 2 and the offset direction, There is a corresponding relationship.

?> 0 → end T1 reaches offset in -X direction than processing mark M → offset in + X direction;

?? <0 → end T1 reaches + X direction than processing mark M → offset in -X direction;

Δβ = 0 → End point (T1) reaches just above the machining trace (M) → No offset is required.

In the case shown in Fig. 13, since??> 0, it is specified that it should be offset in the + X direction.

When the offset direction is specified as described above, the offset value is determined based on the workpiece data D1 stored in the storage section 3 and the irradiation position offset data D3, as in the first and second embodiments, The offset amount for the direction is determined (step STP8).

In the case where the profile PF3 is generated such that the pixel value becomes larger as the brightness decreases as in the first and second embodiments, the slope of the two approximate straight lines sandwiching the maximum value of the profile is compared The same correspondence as in the above case is possible.

Instead of the values of the slopes of the two approximate straight lines, the offset direction may be determined based on the tilt angles of the respective approximated straight lines.

As described above, according to the present embodiment, in the case where a cracked substrate can be inclined at the time of machining in the direction orthogonal to the orientation flat when the substrate having the pattern is divided by the crack extension processing, It is possible to appropriately suppress destruction of the unit patterns constituting the individual device chips formed on the patterned substrate when the unit patterns are formed. As a result, the yield of the device chip obtained by dividing the substrate having the pattern is improved.

1: Controller
4: stage
4m: Moving mechanism
5: irradiation optical system
6: upper observation optical system
6a, 16a: camera
6b, 16b: monitor
7: Upper illumination
8: Lower illumination
10: Workpiece
10a: support sheet
11: suction means
100: laser processing device
16: Lower observation optical system
51, 71, 81: Half mirror
52, 82: condensing lens
CR1, CR2: crack
IM1, IM2: captured image
IP, IP1: irradiation position of laser light
L1: Upper illumination
L2: lower illumination light
LB: laser light
M: Processing trace
OF: Orientation Flat
PL: Line to be processed
S1: Top light source
S2: Lower illumination light source
SL: Laser light source
ST: Street
T, T1, T2: Termination position (of crack)
UP: Unit pattern
W: patterned substrate
W1: single crystal substrate
Wa, Wb: (on the substrate with the pattern)

Claims (12)

An emission source for emitting laser light,
And a stage capable of fixing a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns two-dimensionally on a single crystal substrate,
A laser processing apparatus capable of irradiating the substrate with the pattern while scanning the laser light along a predetermined line to be processed by relatively moving the outgoing source and the stage,
And irradiating the laser light so that a processing trace formed on the substrate having the pattern is discretely positioned along the expected processing line by each unit pulse light of the laser light, And a crack extension process can be carried out,
An imaging means capable of imaging a substrate having the pattern placed on the stage,
Further comprising offset condition setting means for setting an offset condition for offsetting the irradiation position of the laser beam from the scheduled processing line in the crack extension processing,
Wherein the offset condition setting means comprises:
Wherein a portion of the substrate having the pattern is set as an execution position of the crack extension processing for setting the offset condition and the machining process for the offset condition setting is performed on the execution position after,
Wherein said image pickup means is configured to pick up a first shot image by picking up an image of said execution position in a state of being focused on a main surface of said substrate having said pattern,
Characterized in that a direction in which the irradiation position of the laser light is to be offset during the crack extension processing is specified by using a first profile obtained by integrating pixel values along the processing direction of the dichroism for the first captured image . The method according to claim 1,
Wherein the offset condition setting means sets the offset condition setting means to the image pickup means so as to acquire the first picked-up image and adjust the focus position of the machining process in a state of being focused on the focal point position of the laser light when the cut- Capturing a second captured image,
A position coordinate of an end of a crack extending from a machining trace formed by the machining process specified from the first profile and a coordinate value of the position coordinate of the end point of the crack extended from the machining trace formed by the machining process and the pixel value along the machining direction of the tangent to the second picked- And specifies the direction in which the irradiation position of the laser beam should be offset during the crack extension processing, based on a difference value between the machining mark and the position coordinate of the machining trace specified from the obtained second profile. Processing equipment. The method according to claim 1,
The offset condition setting means specifies a direction in which the irradiation position of the laser light should be offset during the crack extension processing based on the slope of two approximate curves sandwiching the extremum in the first profile . An outgoing source for emitting laser light,
And a stage capable of fixing a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns two-dimensionally on a single crystal substrate,
A laser processing apparatus capable of irradiating the substrate with the pattern while scanning the laser light along a predetermined line to be processed by relatively moving the outgoing source and the stage,
Irradiating the laser beam with a laser beam so that a processing trace formed on the substrate having the pattern is discretely positioned along the expected processing line by each unit pulse light of the laser beam, And a crack extension process can be carried out,
An imaging means capable of imaging a substrate having the pattern placed on the stage,
Further comprising offset condition setting means for setting an offset condition for offsetting the irradiation position of the laser beam from the scheduled processing line in the crack extension processing,
Wherein the offset condition setting means comprises:
After setting a portion of the substrate having the pattern as an execution position of the crack extension processing for setting the offset condition and performing the machining of the crack extension processing for setting the offset condition to the execution position,
Wherein said image pickup means is configured to pick up a first shot image of said machining execution position while focusing on a main surface of said substrate having said pattern and to acquire a first picked up image, And a second picked-up image is obtained by picking up the above-mentioned execution position of the above-
A difference value between the position coordinate of the end of the crack extended from the machining trace formed by the machining process and the position coordinate of the machining trace of the machining process specified from the second picked-up image, which is specified from the first picked- , The direction of offsetting the irradiation position of the laser beam during the crack extension processing is specified. 5. The method of claim 4,
Wherein the offset condition setting means sets the offset condition for each of the first picked-up image and the second picked-up image based on an integration profile obtained by integrating the pixel values along the processing direction of the dummy disclosure in each of the first picked- The position coordinate of the end point, and the position coordinate of the machining trace in the dummy disclosure. The method according to any one of claims 2, 4, and 5,
Wherein the offset condition setting means sets the offset amount when offsetting the irradiation position of the laser beam from the scheduled processing line during the crack extension processing to an offset amount of the object Based on information obtained by the laser processing apparatus. There is provided a method of manufacturing a semiconductor device, the method comprising: irradiating a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns two-dimensionally on a single crystal substrate, The method comprising:
Wherein the step of disposing the patterned substrate comprises irradiating the laser light so that a processing trace formed on the substrate having the pattern by the unit pulse light of the laser light is discretely positioned along the expected processing line , A crack extension process that extends cracks from the respective process marks to the patterned substrate,
And an offset condition setting step of setting an offset condition for offsetting the irradiation position of the laser beam from the scheduled processing line in the crack extension processing prior to the crack extension processing,
In the offset condition setting step,
A step of setting a part of the substrate having the pattern as an execution position of the crack extension processing for setting the offset condition and performing the machining process for the crack extension processing for setting the offset condition ,
An imaging step of causing a predetermined imaging means to pick up a first captured image by picking up an image of said execution position in a state of being focused on a main surface of a substrate having said pattern,
A first profile obtained by integrating a pixel value along a machining direction of the dazzling disclosure with respect to the first picked-up image, an offset direction specifying a direction in which the irradiation position of the laser beam should be offset during the crack extension processing And a specific process is performed on the patterned substrate. 8. The method of claim 7,
Wherein the imaging step acquires the first picked-up image to the imaging unit and performs imaging of the machining execution position in a state of focusing on the focal point of the laser light when the machining is performed To acquire a second captured image,
In the offset direction specifying step, the position coordinates of the end of the crack extending from the machining trace formed by the machining, which is specified from the first profile, and the position coordinate of the end of the crack extending from the machining trace formed by the machining to the second picked- On the basis of a difference value between the position of the machining trace and the position coordinate of the machining trace of the machining, which is specified from the second profile obtained by integrating the pixel values, specifies the direction in which the irradiation position of the laser beam should be offset Wherein the pattern is formed on the substrate. 8. The method of claim 7,
In the offset direction specifying step, a direction in which the irradiation position of the laser beam should be offset during the crack extension processing is specified based on the slope of two approximate curves sandwiching the extremum in the first profile A method for setting a processing condition of a substrate having a pattern. As a method for setting processing conditions when a substrate having a pattern formed by repeatedly arranging a plurality of unit device patterns on a single crystal substrate is repeatedly irradiated with a laser beam, ,
Wherein the step of disposing the patterned substrate comprises irradiating the laser light so that a processing trace formed on the substrate having the pattern by the unit pulse light of the laser light is discretely positioned along the expected processing line , A crack extension process that extends cracks from the respective process marks to the patterned substrate,
And an offset condition setting step of setting an offset condition for offsetting the irradiation position of the laser beam from the scheduled processing line in the crack extension processing prior to the crack extension processing,
In the offset condition setting step,
A step of setting a part of the substrate having the pattern as an execution position of the crack extension processing for setting the offset condition and performing the machining process for the crack extension processing for setting the offset condition ,
Wherein the predetermined image pickup means is configured to pick up a first shot image by picking up the execution spot of the machining while focusing on the main surface of the substrate having the pattern, An image pickup step of picking up an image of the execution position of the above-mentioned machining while focusing on a focus position and acquiring a second picked-up image;
A difference value between the position coordinate of the end of the crack extended from the machining trace formed by the machining process and the position coordinate of the machining trace of the machining process specified from the second picked-up image, which is specified from the first picked- And an offset direction specifying step of specifying a direction in which the irradiation position of the laser beam should be offset during the crack extension processing. 11. The method of claim 10,
In the offset direction specifying step, based on an integration profile obtained by integrating the pixel values along the processing direction of the tilting announcement in each of the first captured image and the second captured image, And the position coordinates of the machining trace in the dummy disclosure are specified. 12. A method according to any one of claims 8, 10 or 11,
Wherein the offset condition setting step includes:
An offset amount for offsetting the irradiation position of the laser beam from the expected line to be machined during the crack extension processing is set to an offset which is determined based on the previously acquired individual information of the substrate having the pattern to be subjected to the crack extension processing Wherein the pattern forming step further comprises a step of forming a pattern on the patterned substrate.

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