TW201221261A - Laser processing apparatus, processing method of processed object and dividing method of processed object - Google Patents

Abstract

The present invention provides a processing method of divided object capable of more accurately dividing a processed object. The solution is to let a pulse laser light with psec pulse width emitting from a light source in its midway course to a stage branched into a first optical path and a second optical path. For each unit pulse light, the optical path length of the second optical path is so set that the second half pulse light traveling in the second optical path is more delayed than the first half pulse light traveling in the first optical path. The irradiated regions by the first half pulse light and the second half pulse light are the same, and the processing surface of irradiated region of each unit pulse light is irradiated with a pulsed laser light in a discrete way. Because cleavage is generated between the irradiated regions of the processed object, it forms as a starting point for dividing the processed object.

Description

201221261 VI. Description of the Invention: [Technical Field] The present invention relates to a laser processing method for processing a workpiece by irradiating laser light and a laser processing apparatus used in the method. [Prior Art] Various techniques are known as techniques for processing a workpiece by irradiation of laser light (hereinafter, simply referred to as laser processing or laser processing technology) (for example, refer to Patent Documents 1 to Document 4). Patent Document 1 discloses a method of forming a groove (cut groove) having a V-shaped cross section along a line to be divided by a laser stripping when dividing a crystal grain as a workpiece, The die is divided for the starting point. On the other hand, the method disclosed in Patent Document 2 is a method in which a laser beam in a defocused state is irradiated along a planned dividing line of a workpiece (divided body), and a crystal state is generated in the irradiated region as compared with the surrounding region. The fractured and modified region (metamorphic region) having a substantially V-shaped cross section is broken, and the workpiece is divided by the lowest point of the melt-modified region. When forming a division starting point using the techniques disclosed in Patent Document 1 and Patent Document 2, it is important to form a uniform-shaped V-shaped cross section (groove section or metamorphic region) along the scanning direction of the laser light, that is, the direction of dividing the line. Section) to perform the subsequent segmentation well. As a countermeasure for this, for example, the irradiation of the laser light is controlled so that the irradiated area (beam spot) of the laser light per i pulse overlaps before and after. For example, the repetition frequency (unit kHz) set as the most basic parameter for laser processing is R, and the scanning speed (in units of „1111/^(〇 is ¥)

S 156646.doc 201221261 V/R becomes the center interval of the beam spot, but in the technique disclosed in Patent Document 2 and Patent Document 2, laser light is irradiated and scanned under the condition that V/R is 1 or less to make the beam. Points overlap each other. Further, Patent Document 3 discloses a mode in which a modified region is formed inside a substrate by irradiating laser light to a focused spot on a substrate having a laminated portion on the surface thereof, and the modified region is a cutting starting point. Further, Patent Document 4 discloses a method in which a laser beam scanning is repeated a plurality of times for one separation line, and a groove portion and a reforming portion which are continuous in the direction of the separation line in the depth direction are formed, and are discontinuous in the direction of the separation line. Internal reform department. On the other hand, Patent Document 5 discloses a configuration in which laser light is processed using an ultrashort pulse having a pulse width of psec, and the workpiece (plate body) is adjusted by adjusting the position of the focused spot of the pulsed laser light. From the surface layer portion to the surface, minute melting traces of minute cracks are formed in a group to form a separation facilitating region in which the melting traces are connected in a line shape. [PRIOR ART DOCUMENT] [Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. 2006-139. [Patent Document 4] Japanese Patent Laid-Open Publication No. 2008-98465 [Patent Document 5] Japanese Patent Laid-Open Publication No. Hei No. 2005-271563 [Summary of the Invention] [Problems to be Solved by the Invention] 156646.doc 201221261 Segmentation by laser light The starting point and the subsequent division by the cutter are advantageous in terms of autonomy, high speed, stability, and high precision as compared with the diamond dicing which is a mechanical cutting method which has been performed before. However, in the case where the starting point of the division is formed by the laser light by the prior method, π can be avoided to form a so-called processing mark (laser processing mark). The term "processing mark" refers to a metamorphic region in which the material or structure changes as compared with that before irradiation. The formation of the processing marks usually adversely affects the characteristics of the divided workpieces (the original sheets), and is preferably suppressed as much as possible. For example, in the prior laser processing disclosed in Patent Document 2, a light-emitting element having an LED (llght emitting diode) structure or the like is formed on a substrate including a hard brittle and optically transparent material such as sapphire. The edge portion of the light-emitting element (the portion irradiated by the laser light at the time of division) which is divided by the wafer unit is added, and the processing is performed continuously with a width of about μηη and a depth of about μηη to several tens of μηη. mark. Therefore, there is a problem in that the processing mark absorbs light generated inside the light-emitting element, resulting in a decrease in light extraction efficiency from the element. This problem is particularly remarkable in the case of using a light-emitting element structure of a sapphire substrate having a high refractive index. As a result of active research, the inventors of the present invention have obtained the knowledge that when the workpiece is irradiated with laser light to form a starting point of the division, the rationality or ambiguity of the workpiece can be utilized, thereby suppressing it well. The formation of processing marks. Further, it is obtained that the use of ultrashort pulsed laser light in the processing is preferred. In Patent Document 1 to Patent Document 5, there is no disclosure or suggestion that the form of the starting point of the division is formed by the rationality or ambiguity of the object added to the 156646.doc 201221261. The present invention has been made in view of the above problems, and an object thereof is to provide a method for processing a divided body capable of suppressing formation of a processing mark and forming a dividing starting point for more reliably achieving division of a workpiece, and Laser processing equipment used. [Technical means for solving the problem] In order to solve the above problems, the invention provides a laser processing apparatus characterized by comprising: a light source that emits pulsed laser light; and a stage on which the workpiece is placed; The pulsed laser light has an ultrashort pulse light having a pulse width of ^%, and the optical path of the pulsed laser light from the light source to the stage is partially branched into a second optical path and a second optical path in the middle and then merged. The laser processing apparatus further includes an optical path length adjusting mechanism that changes an optical path length of the second optical path; and the pulsed laser light defined as being emitted from the light source branches into a first thunder that advances in the first optical path And projecting the second laser light that is advanced in the second optical path, and the unit pulse light of the pulsed laser light is branched into a unit pulse of the first half pulse light and the second laser light When the light is the second half-pulse light, the optical path length adjusting means is configured to delay the second half-pulse light by the ith half-pulse light in the optical path after the merging The light path length of the second optical path is such that the pulsed light is transmitted to the workpiece while the workpiece is being placed on the stage, and the pulsed light is transmitted to the workpiece The first half pulse light of each unit pulse light and the second half pulse light are irradiated on the processed surface of the workpiece, and are processed on the processed surface of the processed object 156646.doc 201221261 The above-described irradiated regions of the respective unit pulse lights are discretely formed. The invention of the technical solution 2 is as a technical solution! In the laser processing apparatus, the optical path length adjusting mechanism delays the second half pulse light by only 1/3 times the half value width of the unit pulse light with respect to the third half pulse light, and a delay of 1 〇-down The mode of time is longer than the optical path of the second optical path. The invention of claim 2 is the laser processing apparatus according to claim 2, further comprising: a strength adjustment mechanism for adjusting the intensity of the second laser light; and the optical path length adjustment mechanism for causing the second half pulse light to be relative to the first The half pulse light sets the optical path length of the second optical path only by delaying the delay time of the half value width of the unit pulse light by more than 丨 and twice or less; and the intensity adjusting mechanism makes the intensity of the second laser light smaller than The intensity of the second laser light is adjusted in such a manner as to increase the intensity of the first laser light. The invention of claim 4 is the laser processing apparatus according to claim 2, further comprising: a focus adjustment mechanism for adjusting a focus of the second laser light; and the optical path length adjustment mechanism for causing the second half pulse light to be relative to the first The half pulse light sets the optical path length of the second optical path such that the delay time of the half value width of the unit pulse light is delayed by more than 丨 and twice or less; and the focus adjustment mechanism causes the beam diameter of the second laser light The focus of the second laser light is adjusted in a manner larger than the beam diameter of the laser light. The invention of claim 5 is a processing method for forming a starting point of the workpiece, wherein the optical path setting step includes a light source of the pulsed laser light having an ultrashort pulse of light having a pulse width of psec. The optical path of the stage of the processing object is set to be halved to the optical path and the second optical path and merged thereafter; the optical path length adjusting step is defined as the pulsed laser branch of the pulse emitted from the light source. In the above-mentioned (the i-th laser light that advances in the optical path and the second laser light that advances in the second optical path, and the unit pulse light of the pulsed laser light is branched into the unit pulse light of the second laser light, that is, the i-th The half-pulse light and the second half-pulse light of the unit laser light of the second laser light are set to set an optical path length of the second optical path such that the second half-pulse light is delayed more than the first half-pulse light; a placing step of placing the workpiece on the stage; and an irradiation step of irradiating the second half pulse light and the second half pulse light of each unit pulse light The region is the same, and the pulsed region of the unit pulse light is discretely formed on the surface to be processed of the workpiece, and the pulsed laser light is irradiated onto the workpiece to be irradiated The above-mentioned workpiece is processed or cleaved between the regions to form a starting point for the division of the workpiece. The invention of claim 6 is a method for processing a workpiece according to claim 5 In the optical path length adjustment step, the above-described second half-pulse light is set to be delayed by only 1/3 times or more and twice or less the half-value width of the unit pulse light with respect to the first half-pulse light. The invention is the method of processing the workpiece according to the sixth aspect of the invention, wherein the method further includes the step of adjusting the intensity of the second laser light; and the step of adjusting the optical path length The second half-pulse light is delayed by only one time or more and two times or less the half value width of the unit pulse light with respect to the first half pulse light by 156646.doc 201221261. The optical path length of the second optical path is set in a delay time manner, and the intensity of the second laser light is adjusted so that the intensity of the second laser light is smaller than the intensity of the second laser light in the intensity adjustment step. The invention of claim 8 is the method for processing a workpiece according to claim 6, wherein the towel further includes a focus adjustment step of adjusting a focus of the second light #光; in the optical path length adjustment step, the second half pulse is The light path length of the second optical path is set so that the first half-pulse light is delayed by one time or more and two times or less the half-value width of the unit pulse light, and the focus adjustment step is performed. The focus of the second laser light is adjusted such that the beam diameter of the second laser beam is larger than the beam diameter of the second laser beam. The invention of claim 9 is the method for processing a workpiece according to any one of claims 5 to 8, wherein the above-mentioned workpiece is formed adjacent to each other in a direction in which it is easy to open or split, and the above is different. At least two illuminated regions formed by unit pulsed light. The invention of claim 10 is the method for processing a workpiece according to claim 9, wherein all of the irradiated regions are formed along a direction in which the workpiece is easily split or split. The invention of claim 11 is the method for processing a workpiece according to claim 9, wherein the formation of the at least two irradiated regions is alternately performed in two directions in which the workpiece is different from the above-mentioned workpiece. The invention of claim 12 is the method for processing a workpiece according to any one of claims 5 to 8, wherein the irradiation is performed in a direction equivalent to the difference of the above-mentioned workpiece = 156646.doc 201221261 An area that is easy to open or split. The invention of claim 13 is a method of dividing a workpiece, and the workpiece having the division starting point formed by the method of the fifth aspect of the invention is divided along the division starting point. [Effects of the Invention] According to the inventions of the first to thirteenth aspects, the formation of the processing marks or the scattering of the workpiece due to the deterioration of the workpiece can be limited to a local phenomenon, and the other can be actively The workpiece is subjected to cleavage or cleavage to form a starting point of the workpiece at a very high speed compared to the prior art. In particular, according to the inventions of claims 2 to 4 and 6 to 8, the energy utilization efficiency of the pulsed laser light is improved, so that the division can be performed more efficiently and surely. <Principle of Processing> The principle of processing realized in the embodiment of the present invention shown below will be described. The processing performed in the present invention is roughly as follows: scanning pulsed laser light (hereinafter also referred to simply as laser light) to irradiate the pulsed laser light onto the upper surface (processed surface) of the workpiece, Thereby, the workpiece is sequentially processed or cleaved between the irradiated regions of the respective pulses, and the starting point for the division is formed as the continuous surface of the cleavage plane or the cleavage plane formed on each of the pulses ( Split the starting point). Further, in the present embodiment, the cleavage means that the workpiece is substantially regularly broken along the crystal plane other than the cleavage plane, and the crystal surface is called cleavage 156646.doc •10·201221261 In addition to the microscopic phenomenon of the microscopic phenomenon, the cleavage of the nucleus is completely along the surface of the crystal. Depending on the substance, there are also only those that are mainly responsible for philosophical, cleavage, or cracking—to 71 pairs of 劈 “to avoid the cumbersome explanations and the cleavage and the cracks are not treated separately as cleavage/cleavage, etc.: 'The processing of the above-described form is sometimes referred to simply as splitting/cracking processing, etc. Hereinafter, the workpiece is a hexagonal single crystal material, and the U-axis 'U: and the axis of the a3 axis are easy. The case of the direction of splitting/cracking is exemplified. For example, the c-plane sapphire substrate or the like conforms to this. The ai axis, the a2 axis, and the a3 axis of the hexagonal crystal are mutually symmetrical at an angle of 12 于 in the c-plane. In the processing of the present invention, there are several patterns depending on the relationship between the direction of the equiaxions and the direction of the predetermined processing line (predetermined processing direction). Hereinafter, the pattern such as the hai will be described. The laser light that is pulsed and irradiated is called unit pulse light. <First Processing Pattern> The first processing pattern is a form in which the i-axis direction, the a2-axis direction, and the a3-axis direction are parallel to the pre-twisting line. More generally, it is a processing form in which the direction of easy splitting/cracking is consistent with the direction of the predetermined processing line. Fig. 1 is a view schematically showing a processing form of a second processing pattern. In the case of Fig. i, the case where the axis of the al axis is not parallel to the predetermined processing line L is exemplified. Fig. 1(a) is a view showing the relationship between the a-axis direction, the a2-axis direction, and the a3-axis direction in the case of a predetermined processing line. Fig. 1(b) shows a unit pulse of the first pulse of the laser light 156646.doc 201221261 A state in which the light is irradiated to the irradiated region re丨 at the end of the predetermined processing line L. In general, the irradiation of the unit pulsed light applies a higher energy to the extremely small area of the workpiece. Therefore, the irradiation causes the irradiated area corresponding to the unit pulse light (laser light) of the illuminated surface or is more The deterioration, melting, evaporation, and the like of the substance are generated within a wide range of the irradiation area. However, when the irradiation time of the unit pulsed light, that is, the pulse width is set to be extremely short, the substance in the substantially central region of the irradiated area RE1 which is narrower than the spot size of the laser light obtains the kinetic energy from the irradiated laser light and the plasma The temperature is changed to a gas state or the like, and is further pulverized in a direction perpendicular to the surface to be irradiated. On the other hand, the impact generated by the irradiation of the unit pulse light represented by the reaction force generated by the scattering or The stress acts on the periphery of the irradiated region, and particularly acts in the a-axis direction, the a2-axis direction, and the a3-axis direction which are directions which are easy to open/split. Thereby, the contact state is maintained in the direction in the direction but partially generates minute cleavage or cleavage' or a state in which thermal deformation is caused but does not cause cleavage or cleavage. In other words, it can be said that the irradiation of the unit pulse light of the ultrashort pulse functions as a driving force for forming a weak portion having a substantially linear shape in a plan view in a direction in which the opening/cleaving is easy. In FIG. 1(b), a weak intensity portion in the +al direction which coincides with the direction in which the predetermined processing line L extends is schematically indicated by a broken line arrow in a weak intensity portion formed in each of the above-described easy splitting/cracking directions. . Then, when the unit pulse light of the second pulse of the laser light is irradiated as shown in FIG. 1(c), the irradiated region r1 is formed at a position on the predetermined processing line L from the irradiated region RE1 only by a certain distance, and Similarly to the 1 pulse, a weak intensity portion along the direction of easy splitting/cracking is also formed under the second pulse of 156646.doc 12 201221261. For example, a weak intensity portion W2a is formed in the _al direction, and a weak intensity portion W2b is formed in the +ai direction. However, at this point of time, the weak intensity portion formed by the irradiation of the unit pulse light of the first pulse is in the extending direction of the weak intensity portion W2a. That is, the direction in which the weak-strength portion W2a extends is a portion where energy can be generated or cleaved (high energy absorption rate) smaller than other portions. Therefore, in actuality, when the unit pulse light of the second pulse is irradiated, the impact or stress generated at this time is propagated in the direction of easy splitting/cleaving and the weak intensity portion at the tip end thereof, which is substantially weak at the moment of irradiation. The intensity portion W2a to the weak intensity portion wi produces a thorough cleavage or cleavage. Thereby, the cleavage/cleavage plane C1 which is not shown in Fig. i(d) is formed. Further, the texture/cleavage plane C1 can be formed to a depth of about 4,111 to several tens of μηη in the direction perpendicular to the self-image of the workpiece. Further, as described above, on the cleavage/cleavage plane C1, slippage occurs on the crystal plane as a result of strong impact or stress, and undulation occurs in the depth direction. Then, when the irradiated areas RE1, RE2, RE3, RE4, .. are sequentially irradiated with the unit pulse light by scanning the laser light along the predetermined processing line L as shown in FIG. 1(e), 'corresponding to this The cleavage/cleavage planes C2, C3 — are formed in sequence. In this form, the cleavage/cleavage plane is continuously formed into a split/cleavage process of the first processed pattern. It can be said from other viewpoints that the surface layer portion of the workpiece is expanded by applying heat energy by irradiating the unit pulse light, and the larger central region of each of the irradiated regions RE1, RE2, RE3, RE4, ... Outside 156646.doc -13- 201221261 Side effects and cleavage / cleavage to promote splitting / splitting. C2. · Vertical tensile stress, in the multiplexed pattern, the ',,,, and regions are discretely disposed along the predetermined processing line 1 and the cleavage/cleavage plane formed between the plurality of illuminated regions When the total processing is performed, the predetermined processing line L divides the workpiece into 1 and also Iβ 35°. After forming the starting point of the division, the division is performed using a specific division, and the processing line L can be substantially along the line L. The form divides the workpiece. In order to realize the splitting/cracking process, it is necessary to irradiate a short pulse of laser light having a short pulse width. Specifically, it is necessary to use laser light having a pulse width of 100 psec or less. For example, it is preferable to use laser light having a pulse width of about i (four) to about (four). On the other hand, the irradiation pitch of the unit pulse light (the center interval of the irradiated spot) may be set within a range of 4 μm to 50 μm. If the irradiation pitch is larger than this, the formation of the weak strength portion in the direction in which the splitting/cleaving is easy to occur cannot progress to the extent that the cleavage/cleavage plane can be formed, and thus the self-contained cleavage/cleavage is formed. The viewpoint of the starting point of the segmentation is not considered well. Furthermore, in terms of scanning speed, processing efficiency and product quality, it is preferable that the irradiation distance is larger, but in order to form the cleavage/cleavage surface more reliably, it is preferable to be in the range of 4 μm to 30 μm. The setting is preferably from 4 μηι to 15 μπι. Currently, when the repetition frequency of the laser light is R (kHz), unit pulse light is emitted from the laser light source at 1/R (msec). When the laser light is relatively moved at a speed V (mm/sec) with respect to the workpiece, the irradiation 156646.doc • 14 - 201221261 The pitch Δ (μιη) is defined by Δ^ν/R. Therefore, the scanning speed v of the laser light and the repetition frequency are defined in such a manner that Δ is several μηη. For example, the scanning speed 乂 is about 50 mm/sec to 3000 mm/sec, and the repetition rate is from 1 kHz to 2 kHz kHz, preferably from about 10 kHz to about 200 kHz. The specific value of V*R can also be appropriately set in consideration of the material, absorption rate, thermal conductivity, melting point, and the like of the workpiece. The laser light is preferably irradiated with a beam diameter of about 1 μm to 10 μϊη. In this case, the peak power density of the laser light irradiation is approximately 〇j TW/cm2 to several 10 TW/cm2. Further, the irradiation energy (pulse energy) of the laser light can also be appropriately determined within the range of 5 〇. Fig. 2 is an optical microscope image of the surface of the workpiece having the division starting point formed by the splitting/cracking process by the second processing pattern. Specifically, the sapphire C-plane substrate is used as a workpiece, and the result of the processing of the irradiated spot is discretely formed at intervals of 7 with the a-axis direction being the extending direction of the predetermined processing line on the c-plane. The results shown in Fig. 2 indicate that the actual workpiece is processed by the above mechanism. Moreover, FIG. 3 is a SEM (scanning electron microscope) from the surface (c surface) to the 〇J plane of the sapphire c-plane substrate having the division starting point formed by the processing of the second processing pattern along the division starting point. Electron microscope) image. Further, in Fig. 3, the boundary portion between the surface and the cross section is indicated by a broken line. 3, 156646.doc, ^ 201221261 elongated triangular shape or needle-like region is observed from the surface of the workpiece to the inside at substantially equal intervals in the range from the left and right sides of the surface. It is a region (hereinafter referred to as a direct metamorphic region) in which a phenomenon such as deterioration or scattering is directly caused by irradiation of a unit pulsed light. Moreover, it is observed that a stripe-shaped portion having a longitudinal direction in the left-right direction observed between the direct metamorphic regions is observed at a submicron pitch in a plurality of regions viewed from the upper and lower directions in the drawing. Cleavage face. The lower part of the direct metamorphic area and the cleavage/cleavage plane are the split planes formed by the division. The region where the cleavage/cleavage plane is formed is not the region irradiated with the laser light. Therefore, in the processing of the first processing pattern, only the directly deformed regions which are discretely formed become the processing marks. Moreover, the size of the directly deteriorated region on the surface to be processed is only about several hundred nm to 1 μmη. Namely, by performing the processing in the i-th processing pattern, the formation of the division starting point can be realized as compared with the prior art, and the formation of the processing marks can be preferably suppressed. Further, as observed in the SEM image as a stripe portion, it is actually a micro unevenness having a height difference of about ηηι to 丨μιη formed on the cleavage/cleavage surface. When the embossing is caused by an inorganic compound such as sapphire hard and brittle, the impact or stress caused by the irradiation of the unit pulse light on the workpiece is caused by the specific crystal plane. The person formed by the slide. According to FIG. 3, it is determined that the surface and the cross section are substantially orthogonal to each other by the wave and the line portion. Therefore, it can be said that the fine unevenness is within the allowable range as a machining error, and the second processing is performed. When the pattern forms the starting point of the division and divides the workpiece along the starting point of the division, the workpiece can be divided substantially vertically with respect to the surface. 156646.doc -16· 201221261 Situation. (4) When there is a positive magnetism to form the fine concavities and convexities, the first processing pattern can be processed, and the light extraction efficiency obtained by the second processing pattern described below can be achieved to the extent that The effect of improvement. '1 and significantly <Second processing pattern> The shape of the first processing pattern W, the a-axis direction, the a2 drawing direction, and the fixed processing line are perpendicular to the split/split processing. Then = ^ 2 processing a picture f to make the conditions of the laser light used in contrast with the first] processing pattern - generally equivalent to the direction of the two different easy to open / split directions (to become 2 The direction in which the direction of the axis of symmetry of the direction in which the splitting is easy to open/break is the processing direction of the predetermined processing line. Fig. 4 is a view schematically showing a processing form of the second processing pattern. In Fig. 4, the case where the direction of the a-axis is not orthogonal to the predetermined processing line L is exemplified. Fig. 4 (sentence diagram shows the direction of the ag direction, the direction of the a2 axis, and the relationship between the direction of the axis and the orientation of the predetermined processing line l in Fig. 4. Fig. 4(b) shows the unit pulse light of the third pulse of the laser light irradiated to the predetermined In the case of the second processing pattern, in the case of the second processing pattern, the weak intensity portion is formed by irradiating the unit pulse light of the ultrashort pulse as in the jth processing pattern. b) in the 'dash arrow' schematically indicates the weak intensity in the -a2 direction and the +a3 direction which are formed in the weak intensity portion in the direction of the above-mentioned easy splitting/cracking, which is close to the extending direction of the predetermined processing line L. a portion of wi la, W12a. Further, as shown in FIG. 4(c), when the unit pulse light of the second pulse of the laser light is irradiated, a position on the predetermined processing line L from the irradiated region re 11 is separated by a specific distance. In the irradiated area RE12, similarly to the second pulse, 156646.doc 17. 201221261 also forms a weak intensity portion along the direction of easy splitting/cleaving under the second pulse. For example, weakly formed in the -a3 direction. The strength portion Wllb forms weak in the +a2 direction The portion W12b forms a weak intensity portion Tile in the +a3 direction and a weak intensity portion W12c in the -a2 direction. In this case, as in the case of the first processing pattern, the unit pulse light of the first pulse is irradiated. The formed weak strength portions W1 la, W12a are respectively in the extending direction of the weak intensity portions W11 b, W12b, so that when the unit pulse light of the second pulse is irradiated, the impact or stress generated at this time is easily split/cracked. The direction of the opening and the weak intensity portion at the front end propagate, that is, as shown in Fig. 4(d), 'the cleavage/cleavage planes cila, Cllb are formed. Further, in this case, the cleavage/cleavage plane cna, Cllb can also be formed in the vertical direction of the workpiece to a depth of several pm to several tens of μm. Then, when scanning the laser light along the predetermined processing line l as shown in Fig. 4(e), When the irradiation areas RE11, RE12, RE13, and RE14 are sequentially irradiated with the unit pulse light, the impact or stress generated during the irradiation is sequentially formed along the predetermined processing line L as a straight line viewed from the drawing. / cleavage plane cUa and Cllb, C12a and C12b, C 13a and C13b, C14a, and C14b.... As a result, the state in which the cleavage/cleavage plane is located at a symmetrical position with respect to the predetermined processing line is realized. In the second processing pattern, the plural number exists discretely along the predetermined processing line L. The area to be irradiated is the starting point of the division when the workpiece is divided along the predetermined processing line L as a whole, and the processing/disintegration surface existing in the zigzag shape is as shown in Fig. 5. Fig. 5 is the opening/split by the second processing pattern An optical microscope image of the surface of the workpiece having the starting point of 156646.doc -18-201221261 is formed by machining. Specifically, it indicates that a sapphire c-plane substrate is used as a workpiece, and a row is formed on the c-plane by a direction orthogonal to the axial direction as a predetermined processing line [the extending direction and discretely formed at intervals of 7 μm. The light spot "The result of the processing. (4) Fig. 5, in the workpiece to be processed in the same way as in the figure 4(e)", as shown in the figure, it is confirmed that it is jagged (serrated) from the front. The result is that the actual workpiece is processed by the above mechanism. [8] FIG. 6 is a sapphire C-plane substrate having a division starting point formed by processing the second processing pattern. The SEM image from the surface (C surface) to the cross section after the splitting start point is divided. Further, the boundary portion between the surface and the scraping surface is indicated by a broken line in Fig. 6. According to Fig. 6, the cross section of the workpiece after the division In the range from the surface to the left and right, it is confirmed that the cross section of the workpiece has the unevenness corresponding to the zigzag arrangement schematically shown in Fig. 4, and the irregularities are formed as the cleavage/cleavage plane. The distance between the bumps in Fig. 6 is about 5 μηη. In the same manner as in the processing of the pattern, the cleavage/cleavage plane is not flat, and the specific crystal plane is slid by the irradiation of the unit pulsed light, and the unevenness of the submicron pitch is generated. The surface extending from the surface portion in the depth direction is a cross section of the direct metamorphic region, and the shape is uneven compared to the direct metamorphic region formed by the processing of the first processing pattern shown in Fig. 3. Moreover, 'these are directly deteriorated. The area and the cleavage/cleavage plane are lower than the split surface formed by the division. The case of the second processing pattern is also the same as the direct deterioration of the discrete formation. 3⁄4 156646.doc 201221261 The area becomes the processing mark The aspect is the same as that of the first processing pattern. Moreover, the size of the directly deteriorated region in the surface to be processed is only several hundred nm to 2 μm and the right side, that is, when processing is performed in the second processing pattern, processing can also be realized. The formation of the mark is better than the formation of the previous starting point of the segmentation. In the case of the processing of the second processed pattern, except for the unevenness of the submicron pitch formed on the cleavage/cleavage plane, adjacent The texture/cleavage planes are formed with irregularities at a distance of about several μm. The form of the cross section having the uneven shape is effective in the case where it is to be on a substrate containing a hard brittle and optically transparent material such as sapphire. The object to be processed having the structure of a light-emitting element such as a led structure is divided into units of a wafer (divided original piece). In the case of a light-emitting element, light is absorbed at a portion of a processing mark formed on the substrate by laser processing. When the light generated inside the element is light, the light extraction efficiency from the element is lowered, but when the concave and convex portions shown in FIG. 6 are formed on the processed cross section of the substrate by intentionally processing the second processing pattern, The total reflectance of the position is lowered to achieve higher light extraction efficiency in the light-emitting element. <Third processing pattern> The third processing pattern is perpendicular to the predetermined processing line in terms of the use of the ultrashort pulse laser light, and the "axis direction a2 axis direction and the a3 axis direction are both perpendicular to the predetermined processing line (the two are easy to open with respect to each other) The direction in which the direction of the split is equivalent to the direction of the predetermined processing line is the same as that of the second processed pattern, but the irradiation form of the laser light is different from the second processed pattern. FIG. 7 schematically shows the third processed pattern. Fig. 7 is a case where the direction of the &1 axis is orthogonal to the predetermined processing line L. Fig. 7(a) shows]56646.doc -20- 201221261 The a-axis direction and the a2-axis direction of the case And a view of the azimuthal relationship between the a3 axis direction and the predetermined processing line L. In the second processing pattern described above, in the same orientation relationship as that shown in Fig. 7(a), along the extending direction of the predetermined processing line L, The a2 axis direction and the a3 axis direction are in the middle direction (the direction equivalent to the a3 axis direction and the a3 axis direction), and the laser light is linearly scanned. In the third processing pattern, instead of this, as shown in FIG. 7(b) So that each of the illuminated areas is alternately processed along the clamping The two directions of the L-opening/cleaving direction are formed in a zigzag (zigzag) manner, and the unit pulse light forming each of the irradiated regions is irradiated. If the case of Fig. 7 is used, the alternately along - In the a2 direction and the +a3 direction, the irradiated regions RE21, RE22, RE23, RE24, RE25, ... are formed. When the unit pulse light is irradiated in this manner, similarly to the first processed pattern and the second processed pattern, The cleavage/cleavage plane is formed between the irradiated regions with the irradiation of the respective unit pulsed light. If it is the case shown in Fig. 7(b), the irradiated regions RE21, RE22, RE23, RE24 are sequentially formed. RE25..., and the cleavage/cleavage planes C21, C22, C23, C24, ... are sequentially formed. As a result, in the third processing pattern, a zigzag arrangement with the predetermined processing line L as an axis is used. The plurality of irradiated regions which are discretely present and the texture/cleavage plane formed between the respective irradiated regions are the starting points of the division when the workpiece is divided along the predetermined processing line L as a whole. Actually, when dividing along the starting point of the segmentation, and the second The work pattern is similarly formed in a range of about 10 μm from the surface of the cross-section of the workpiece to be processed, and the unevenness of the number of 156646.doc •21 - 201221261 μπι caused by the cleavage/cleavage plane is formed. In the same manner as in the case of the second processing pattern and the second processing pattern, the respective processing/cleavage planes are caused by the sliding of the specific crystal plane due to the irradiation of the unit pulsed light, and the submicron pitch unevenness is directly generated. The formation form of the metamorphic region is also the same as that of the second processing pattern. That is, in the third processing pattern, the formation of the processing marks is also suppressed to the same extent as the second processing pattern. Therefore, in the case of processing the third processed pattern, in addition to the processing of the second pattern, in addition to the unevenness formed on the submicron pitch of the cleavage/cleavage surface, the cleavage/cleavage planes are mutually In the case where the third processing pattern is processed for the light-emitting element, the obtained light-emitting element is more preferable from the viewpoint of improving the light extraction efficiency described above. Further, depending on the type of the workpiece, it is possible to produce the cleavage/cleavage more reliably, or the position on the predetermined processing line L, that is, the irradiated area RE21 and the irradiated area RE22 of Fig. 7(b). The midpoint, the midpoint of the irradiated area RE22 and the irradiated area RE23, the point of the irradiated area RE23 and the irradiated area RE24, and the point of the irradiated area RE24 and the irradiated area rE25 form an illuminated area. Further, it is said that the arrangement position of the irradiated area in the third processing pattern is partially along the direction in which the opening/cleaving is easy. The same applies to the case where the irradiated area is formed at the midpoint position on the predetermined processing line L as described above. In other words, the third processing pattern can be formed to be common to the first processed pattern in that at least two of the irradiated regions are adjacently formed in the direction in which the workpiece is easily split/cleared. Therefore, the 'in other words' third processing pattern can also be regarded as processing the i-th processing pattern while periodically omitting the direction of the scanning laser light 156646.doc -22· 201221261. Further, in the case of the i-th processing pattern and the second processing pattern, the irradiated area is located on a straight line, so that the emission source of the laser light is moved along the 'pre-processing line on the straight line every time to reach a specific formation. Irradiation at the position of the object: It is only necessary to form the irradiated area by the pulsed light. This formation form is most effective early. However, in the case of the third processing pattern, it is formed in a recorded shape (zigzag) without being aligned. Since the irradiation area is used, not only can the laser light source be actually moved in a zigzag manner (zigzag), but also the irradiated area can be formed by such a method. Furthermore, the movement of the print source in the present embodiment refers to the relative movement of the workpiece and the exit source, and includes not only the workpiece being fixed but the source being moved, but also the source being fixed and being moved by the object. (actually, it is a form in which the stage on which the workpiece is placed is moved). For example, the m-plane causes the exit source and the stage to move at a constant speed in parallel with the predetermined guard line, and the -plane causes the exit direction of the laser light to periodically change in a plane perpendicular to the predetermined processing line, etc. The irradiated region is formed in a form satisfying the above-described mineral tooth configuration. Alternatively, 'the plurality of emission sources are relatively moved in parallel at a constant speed by the surface, and the irradiation timing of the unit pulse light from each of the emission sources is periodically changed' to satisfy the above-described configuration of the ore-like arrangement relationship. Shaped Irradiation Area ❶ Fig. 8 is a view showing the relationship between the predetermined processing line and the predetermined formation position of the irradiated area in the two cases. In either case, it can be regarded as shown in Fig. 8 'like the predetermined formation positions (2), P22, P23 'P24, p25... of the areas to be irradiated RE21, re22 re23 re24, RE25·., 156646.doc -23 - 201221261 6X is set on the straight line La, ίβ parallel to the predetermined processing line L, and is simultaneously formed in parallel with the irradiated area of P21, P23, P25, ... along the predetermined formation position of the straight line La, and The formation of the illuminated regions of the predetermined positions P22, P24, ... of the straight line Lp is formed. In addition, when the output source is moved in a zigzag manner (serration), the source of the laser light is directly moved, or the laser beam is relatively scanned by moving the stage on which the workpiece is placed. The movement of the exit source or the stage is simultaneous operation of the two axes. On the other hand, the operation of moving only the source or the stage in parallel with the predetermined processing line is a single-axis operation. Therefore, the latter is preferable in terms of realizing high-speed movement of the discharge source, that is, improvement in processing efficiency. As shown in each of the above processing patterns, the splitting/cracking process performed in the present embodiment is mainly for imparting a discrete treatment of the unit pulse light to impart a continuous treatment/solution for the workpiece. The processing form of the mechanism of impact or stress. The deterioration of the workpiece in the irradiated area (formation of the processing marks) or the scattering, etc., is only incidental to the local producer. The mechanism of the splitting/cracking process of the present embodiment having this feature is substantially different from the fact that the irradiation region of the unit pulsed light is repeatedly or intermittently deformed, melted, and evaporated by one side. The previous processing method for processing. Further, it is sufficient to apply a strong impact or stress to each of the irradiated regions instantaneously, so that the laser light can be irradiated while scanning at a high speed. Specifically, S ′ can be scanned at a very high speed of up to 1000 mm/sec, that is, south speed machining. The processing speed of the cloud in the previous processing method is at most about 200 mm/sec, which is more significant. Of course, it can be said that the processing method realized by 156646.doc -24· 201221261 in the present embodiment significantly improves the production compared with the previous finishing method, and the opening/spliting in the present embodiment is 5, π 丄It is particularly effective in the case where the crystal orientation of the workpiece (the direction in which the direction is easy to open/split) is determined in relation to the predetermined line (4), and the object to be applied is not limited (4). In principle, it can also be applied. (4) The person is in the relationship of ff or the gamma is multi-crystal. In such cases, the direction of cleavage/cleavage relative to the predetermined jade line is not necessarily fixed; Therefore, irregular irregularities are generated at the starting point of the splitting, but by appropriately sighing the irradiation conditions of the irradiated regions and the laser light represented by the pulse width, the allowable range of the bumping and stopping (four) guarding error can be performed. It is only used for processing that does not have problems. <Cutter-off beam energy utilization efficiency upwards> The split/crack process of the present embodiment is such that the pulse width of 1 〇〇psec or less is separated by the separation between about 4 pm and 50 μηι as described above. The unit pulsed light causes deterioration, melting, evaporation, and the like of the substance in the central portion of each of the irradiated regions, thereby causing the cleaving/cracking to progress to between the irradiated regions. Therefore, it is not necessary to carry out the necessary processing in the irradiated area, and it is of course necessary to make the cleavage/cleavage progress from the irradiated area with respect to the direction in which it is easy to open/crack. For example, 'in the case of a unit pulse light having a large peak power density and a small pulse width, the excess energy applied to the irradiated area causes more damage than necessary to the irradiated area, and on the other hand causes lumps/ Cleavage cannot progress better. The reason for this is that the energy of the unit pulsed light that is irradiated is not fully utilized for the progress of the cleavage/cleavage. 156646.doc •25· 201221261. More specifically, it can be considered that it takes about 10 psec in the energy absorption from the electronic system to the vibration of the molecular system caused by the energy. Therefore, in order to make the energy of the unit pulsed light of the irradiation more used for the progress of the cleavage/cleavage, it can be said that the peak power density is suppressed to the unit of the weakest intensity portion and the unit of the pulse width is increased. It is preferable that the pulsed light is irradiated to the form of the workpiece. In this case, the energy utilization efficiency of the laser light is increased. In the present embodiment, the improvement of the energy use efficiency is achieved by optically temporarily dividing each unit pulse light into two parts, and one of the two is different from the other by making the optical path lengths of the two different. A slight delay (up to about 10 nsec) is applied to the substantially identical illuminated area on the workpiece. The processing of this form is referred to as split beam processing. Hereinafter, the description will be specifically made. Fig. 9 is a view schematically showing a change in the intensity distribution (time change of the beam intensity) of the laser light actually irradiated to the workpiece when the delay time is different. Specifically, it is considered that the unit pulse light UP having the peak intensity (peak power density) 1 and the half value width ω is divided into two first half-pulse lights H1 and a second half pulse having the same distribution as shown in FIG. 9( a ). The light H2 is delayed by the second half pulse light H2 with respect to the first half pulse light H1 by making the optical path lengths of the two different. Set the delay time to d. First, for example, the delay time D shown in FIG. 9(b) is about 1/3 of the half value width ω (number of Psec to several tens of psec) of the unit pulse light UP (in the case of D=co/3). When the delay time is small, the first half pulse light H1 and the second half pulse light H2 are irradiated in time, and the composite pulse light CP1 of the two 156646.doc '26-201221261 is used as the peak. A single unit of pulsed light with a strong intensity and a half-value width is transmitted through. However, by delaying the irradiation of the second half-pulse light H2 with respect to the ith half-pulse light m, the second half-pulse light H2 is irradiated to the first half-pulsed light H1 to cause the substance to be deteriorated, and the cleavage/solution is started. The energy absorption efficiency of the higher state (plasma state or high temperature state) is taken as the 'radiation area'. At this time, the energy of the second half-pulsed light H2 is mainly used for the progress of the cleavage/cleavage. Of course, as the delay time D is increased, the time overlap between the first half pulse light and the second half pulse H2 is small. However, as shown in Fig. 9(c), if the delay time D is wider than the half value of the unit pulse light!^!» (when the same degree is used (when 〇 = ω), the first half pulse light HI The combined pulsed light CP2 with the second half-pulse diaphragm 2 has two peaks of the peak intensity 12 smaller than the peak intensity 11 of the combined pulsed light cpi. However, only the second half-pulse light is irradiated to the second half of the irradiation. The area to be irradiated in the state in which the energy absorption efficiency is high is the same as that in the case of irradiating the combined pulsed light CP1. Further, the combined pulsed light CP2 as a whole can be regarded as a unit of the half value width ω2 (> ω1). Pulse light. When the delay time D is larger than ω and is about twice the half value width ω of the unit pulse light UP as shown in Fig. 9(d) (when D=2〇), 1 half-pulse light H1 and the second half-pulse diaphragm 2 have almost no overlap, and the combined pulsed light CP3 (so named in the name) is essentially merely irradiating the first half-pulse light out in order with the delay time d. The two individual unit pulse lights UP3a and uP3b of the second half pulse light 112 (that is, the peak intensity 13 is approximately P/2). However, the delay time D in this case is at most about 1 〇〇pSeC even if it is increased, so the energy generated by the irradiation of the unit pulse light UP3a is 156646.doc 27· 201221261 The period in which the absorption efficiency is high is not lost. Irradiation unit pulse *up3b. Therefore, the energy of the unit pulsed light UP3b is used for the progress of the cleavage/cleavage plane. In other words, in this case as well, the energy of the unit pulsed light UP emitted from the light source can be efficiently utilized in the same manner as the case where the second half pulse light 1 and the second half pulse light H2 are substantially overlapped. Furthermore, the inventors of the present invention have found that when the delay time D is in the range of approximately n sec, the effect of improving the energy efficiency of the unit pulse light upi described above can be obtained. This is considered to be because the time during which the energy absorption efficiency achieved by the irradiation of the unit pulse light UP3a is maintained is at most about 1 secsec. Further, when the delay time D is lower than ω/3, the effect of delaying the second half-pulse diaphragm 2 cannot be sufficiently obtained, and the workpiece 1〇 is liable to be excessively damaged, which is not preferable. According to the above, if the optical path length difference between the first half-pulse light output and the second half-pulse light H22 is set such that the delay time D is set as a value within a range of 10 nsec or less, even if the unit pulse light emitted from the light source has When the peak power density is excessively damaged to the irradiated area, the peak intensity of the unit pulse light actually irradiated to the workpiece can be lowered, and the irradiation time can be substantially increased, thereby making it possible to Each unit of pulsed light increases the ratio of energy used for the progress of cleavage/cleavage. Specifically, s ' can mainly use the energy of the second half-pulsed light H2 of delayed irradiation for the progress of the cleavage/cleavage. In other words, when the optical path length difference between the first half pulse light H1 and the second half pulse light H2 is set so that the delay time D satisfies the range, and the separation beam processing is performed, the energy utilization efficiency can be further improved. .doc •28- 201221261 Open processing. Thereby, the starting point of the division of the workpiece 10 can be formed more efficiently and surely. In addition, the split beam processing system described so far causes the second half-pulse diaphragm 2 to be delayed in time compared with the first half-pulse diaphragm 2, and both of them are irradiated to substantially the same irradiated region, but on the other hand, In the present embodiment, as described above, the laser beam is relatively scanned while scanning at a scanning speed of about 50 mm/sec to 3000 mm/sec. At first glance, the two seem to be contradictory. This is because 'the period between the irradiation of the first half-pulse light H1 and the second half-pulse light H2 is irradiated, and the laser beam and the workpiece 相对 are also relatively moved. Therefore, the formation position of the irradiated region of each half-pulse light should be There are different. However, even if the scanning speed of the laser light is set to 3 〇〇〇mm/sec (=3 m/sec) and the delay time d is 1 〇nsec, the irradiation position of the first half pulse light H1 and the second half pulse light are set. When the position of H2 is most deviated, the calculation of the deviation between the two positions is only 3〇ηιη❶. On the other hand, the beam of the laser beam is about 1 μιηη to about πμπ1, or is split/cracked. The areas to be irradiated formed on the workpiece 1 at the time of the opening are spaced apart from each other by 4 μm to 50 μm. The value of 30 nm is about 1/1 〇〇 to 1/1 〇〇〇, which can be considered to be sufficiently within the error range. Therefore, even when the first half pulse light H1 and the second half pulse light H2M are incident on substantially the same irradiated region during processing, it is possible. Further, the separation beam processing can be performed when the processing of any of the above-described second processing pattern to the third processing pattern is performed. In the above description, the first half pulse light H1 and the second half pulse light H2 are equally distributed, but this is not necessary.

S 156646.doc -29- 201221261 Form. Fig. 10 is a view showing the intensity distribution of the laser light in the case where the delay time is about twice the half value width of the unit pulse light, but the peak intensity of the second half pulse light H2 is smaller than the peak intensity of the first half pulse light. When the laser beam of this form is used for the separation beam processing, efficient splitting/cracking processing can also be realized. In this case, the beam spot diameter or the diffusion angle of the second half-pulse light H2 may be different from the first half-pulse light H1, so that the irradiation spot of the second half-pulsed light H2 when irradiated to the workpiece may be made. The diameter of the illumination spot having a diameter larger than that of the first half pulse light H1. In this case, the half value width of the second half-pulse light H2 is larger than the half value width of the second half pulsed aperture 1 so that the irradiation time can be further delayed. <Summary of Laser Processing and Swinging> Next, a laser processing apparatus capable of realizing processing of the above various processing patterns will be described. Figure 11 is a view schematically showing the construction of the laser processing apparatus 5 of the present embodiment.

The horse's eye is placed on the side of the stage 7 (referred to as the side of the back or the side of the cut sweat (referred to as the work object 10, the back view or cut surface) via the stage 156646.doc 201221261 7 The workpiece 10 0 β stage 7 S is movable in the horizontal direction between the laser beam irradiation unit 5 〇Α and the observation unit 50 藉 by the moving mechanism 7 m. The moving mechanism 7 m is driven by a driving mechanism not shown. The movement of the stage 7 in the horizontal direction of the χ γ 2 axis in the horizontal plane is performed, whereby the movement of the laser light irradiation position in the laser light irradiation unit 5〇α and the movement of the observation position in the observation unit 50Β are performed. Or the movement of the stage 7 between the laser beam irradiation unit 50A and the observation unit 50A. Further, the rotation (one rotation) in the horizontal plane centered on the specific rotation axis of the movement mechanism 7m may be independent of the horizontal drive. Further, in the laser processing apparatus 50, the front view and the back view can be appropriately switched, whereby the optimum observation corresponding to the material or state of the workpiece 1 can be flexibly and quickly performed. The stage 7 is formed of a transparent member such as quartz, A suction controller (not shown) for sucking and fixing the intake passage of the workpiece 10 is provided inside. The suction pipe is provided by, for example, machining a specific position of the stage 7 by machining. In a state in which the workpiece 1 is placed on the stage 7, the suction pipe is sucked by a suction mechanism 11 such as a suction pump, and the suction pipe is placed on the suction stage. 7 The negative pressure is applied to the suction hole at the front end of the mounting surface side, whereby the workpiece 10 (and the fixing sheet 4) is fixed to the stage 7. Further, in the figure u, the workpiece 1 which is not processed is processed. In the case where the crucible is attached to the fixing sheet 4, it is preferable that a fixing ring (not shown) for fixing the fixing sheet 4 is disposed on the outer edge portion of the fixing sheet 4. <Lighting system and observation system> 156646.doc 2 -31 - 201221261 The observation portion 50B is configured such that the workpiece 10 placed on the stage 7 overlaps the epi-illumination from the epi-illumination light source S1 over the stage 7 The illumination of the light L1 and the oblique light from the oblique illumination source 82 are transmitted through the illumination light L2. The upper side of the stage 7 is viewed from the front by the front view mechanism 6, and the lower side of the stage 7 is viewed from the back side of the stage 7. The specific view is the 'emission illumination light emitted from the epi-illumination source S1. The half lens 9 provided in the lens barrel (not shown) is reflected and irradiated to the workpiece 10. The observation unit 50B is provided with a front observation mechanism 6 including the upper surface of the half lens 9 ( A CCD (charge coupled device) camera 6a and a monitor 6b connected to the CCD camera can perform a bright field of the workpiece 10 in a state where the epi-illumination light L1 is irradiated. Like observation. Further, in the observation unit 50B, the back view mechanism 16 is preferably provided below the stage 7, and the β-Hui back view mechanism 16 includes a CCD camera 16a provided below the half lens unit (below the lens barrel), which will be described later, and the CCD. The monitor 16b to which the camera 16a is connected. Further, the monitor 16b and the monitor 6b provided in the front observation mechanism 6 may be common. Further, the coaxial illumination light L3' emitted from the coaxial illumination light source 33 provided under the stage 7 can also be reflected by the half mirror 19 provided in the lens barrel (not shown) and collected by the collecting lens 18, and The workpiece 7 is irradiated to the workpiece 1 via the stage 7. More preferably, the oblique illumination light source S4 is provided below the stage 7, and the oblique illumination light L4 is irradiated to the workpiece 1 via the stage 7. The coaxial illumination source S3 or the oblique illumination source μ can be preferably used, for example, to have an opaque metal layer or the like on the surface side of the workpiece 156646.doc • 32-201221261 ι〇, which makes it difficult to generate observation from the surface side. When the metal material is reflected, the workpiece 10 is observed from the back side. &lt;Laser light source&gt; As the laser light source SL, a wavelength of 500 nm to 1600 nm is used. Further, in order to realize the processing using the above-described processing pattern, the pulse width of the laser light Lb needs to be about 1 psec to 50 psec. Further, it is preferable that the repetition frequency scale is from about 1 kHz to about 200 kHz, and the irradiation energy (pulse energy) of the laser light is about μ"μ·ί to 50 μ«ί. Further, the polarization state of the laser light LB emitted from the laser light source SL may be either circularly polarized or linearly polarized. However, in the case of linear polarization, it is preferable that the polarization direction is substantially parallel to the scanning direction from the viewpoint of the bending of the processed section and the energy absorption rate in the material to be processed, for example, the angle formed by the two is ±1. . Within. The optical system 5 is a portion where the optical path when the laser light is irradiated to the workpiece 1 is set. The laser beam is irradiated with a specific irradiation position (a predetermined formation position of the irradiated region) of the workpiece in accordance with the optical path set by the optical system 5. Fig. 12 is a schematic view showing the configuration of the optical system 5. The optical system 5 mainly includes a beam expander 51, an objective lens _ 糸 糸, a first 52 branch lens 53 and a synthetic lens, and an appropriate number of lenses 5a may be disposed at appropriate positions in the optical system 5 to convert the laser light β Lens 5 仏 situation. In the direction. In Fig. 12, it is exemplified that 4 and 'when the emitted light is linearly polarized,' is preferably an optical system $

S 156646.doc -33· 201221261 equipped with an attenuator 5b. The attenuator 5b is disposed at an appropriate position on the optical path of the laser beam LB, and functions to adjust the intensity of the emitted laser light LB. As illustrated in Fig. 12, in the optical system 5, a branch lens 53 and a composite lens 54 each having a half lens are disposed on the optical path OP of the laser light LB emitted from the laser light source SL. The optical path OP branches into the first branched optical path OP1 and the second branched optical path OP2 by the branch lens 53, and the first branched optical path OP1 and the second branched optical path OP2 merge in the combined lens 54 to become the optical path OP again. Thereby, the laser light LB emitted from the laser light source SL is separated into the first laser light LB1 that advances in the first branch optical path OP1 and the second laser light LB2 that advances in the second branched optical path OP2 by the branch lens 53. . In this case, the first half pulse light H1 corresponds to the unit pulse light of the first laser light LB1, and the second half pulse light H2 corresponds to the unit pulse light of the second laser light LB2. Further, an optical path length adjusting mechanism 55 is disposed on the second branch optical path OP2. The optical path length adjusting mechanism 55 includes a plurality of lens groups that reflect the second laser light LB2 advancing on the second branched optical path OP2 toward the synthetic lens 54. Further, the optical path length adjusting mechanism 55 is configured as shown by an arrow AR1 in such a manner that the reflection position of the second laser light LB2 can be freely adjusted by changing the position in the extending direction of the second branch optical path OP2. By adjusting the reflection position of the second laser beam LB2 in this manner, the optical path length of the second laser light LB2 advanced in the second branch optical path OP2 can be arbitrarily set. The optical path length adjustment mechanism 55 sets the optical path length of the second branched optical path OP2 to be longer than the optical path length of the first branched optical path OP1, thereby forming the combined lens 54 that merges with the first branched optical path OP1 and the second branched optical path OP2. In the optical path OP on the downstream side, the second laser light LB2 is delayed by 156646.doc • 34· 201221261 with respect to the first laser light LB1. Therefore, in the laser processing apparatus 50, the optical path length difference between the first branched optical path OP1 and the second branched optical path 2p2 is appropriately set by the optical path length adjusting mechanism 55, and the above-described split beam processing can be performed for any delay time D. Furthermore, if the optical path length difference is AL, the relationship between the delay time d and the optical path length difference can be expressed as AI^cD using the speed c of the light. For example, in the case of D = 10 psec, 's is not c=3> &lt;108 m/sec, AL = 3 mm. Further, the focus adjustment lens system 56 is provided on the second branch optical path P2. By appropriately setting the focus adjustment lens system 56, the beam diameter or the diffusion angle of the second pulse light H2 which is the unit pulse light of the second laser light LB2 can be made different from the unit pulse light of the second laser light LB2. ! Half pulse light H1. Thereby, it is possible to process the separated beam in a state where the irradiation spot diameter of the second half pulse light H2 when the object is irradiated is larger than the diameter of the irradiation spot of the first half pulse light H1. Further, by appropriately adjusting the attenuator 5b of the first branch optical path OP or the attenuator 5b of the second branch optical path P2, the intensity of the second laser light LB 2 can be made smaller than that of the first laser light lb 1 The intensity, and thus the separation beam processing under the distribution shown in Fig. 1A, can also be performed. And it is said that it is possible to perform the above-described method of separating the beam processing by preparing two different laser light sources and delaying the emission timing of each laser light, but in fact, the irradiated regions are discretely formed. Under the condition, it is difficult to control the delay of the emission timing from the two laser light sources with pSec level or nsec level with high precision, so it is unrealistic. Furthermore, the image from the objective lens system 52 to the workpiece 1 is illustrated in FIG. The light path of the light LB is fixed. It is also possible to set a plurality of optical paths 156646.doc •35· 201221261 〇p below the synthetic lens 54 in a practical or hypothetical manner, and irradiate each unit pulse light of the laser light LB by an optical path setting mechanism not shown. The optical path to the workpiece is sequentially switched in a plurality of set optical paths. In this case, it is realized in a state in which a plurality of portions on the upper surface of the workpiece 10 are simultaneously scanned in parallel, or assumed to be in such a state. In other words, it can be said that the optical path of the laser light LB is increased. &lt;Controller&gt; The controller 1 further includes a control unit 2 that controls the operation of each of the above-described parts to realize processing of the workpiece 10, and a storage unit 3 that stores a program for controlling the operation of the laser processing apparatus 50 3p or various materials referenced during processing. The control unit 2 realizes, by a computer such as a personal computer or a microcomputer, that the program 3p stored in the storage unit 3 is read into the computer and executed, and various components are used as the functional components of the control unit 2. The elements are implemented. Specifically, the control unit 2 mainly includes a drive control unit 21 that controls the operation of the various driving portions related to the machining process such as the driving of the stage 7 or the focusing operation of the collecting lens 18 by the moving mechanism 7m; the imaging control unit 2 2, which controls the imaging of the CCD cameras 6a and 16a; the illumination control unit 23 controls the illumination of the laser light LB from the laser light source SL and the setting mode of the optical path in the optical system 5; the adsorption control unit 24 controls the borrowing The operation of sucking and fixing the workpiece 1 to the stage 7 by the suction mechanism 11 and the processing unit 25 are processed in accordance with the supplied processing position data D1 (described later) and the processing mode setting data D2 (described later). The object position performs machining processing. 156646.doc -36- 201221261 Storage. Ρ 3 is realized by a storage medium such as R〇M (read-only memory) or RAM (rand〇m-access memory) and a hard disk. Furthermore, the storage unit 3 may be realized by implementing the components of the computer of the control unit 2, and may be in a form separate from the computer when the hard disk is used. The machining position data m of the position where the wealth is added to the line is provided from the outside and stored in the storage unit 3. Further, the storage unit 艸 stores in advance the conditions in which the respective parameters of the laser light are described in the processing mode, the setting conditions of the optical path in the optical system 5, or the driving conditions of the stage 7 (or the settable circumferences), and the like. Add mode mosquito information D2. Furthermore, the operator refers to the various inputs provided by the laser processing apparatus 5, preferably using a controller! Realized in the implementation of Gm (graphicai coffee, such as catching ce, graphical user interface). For example, the processing processing menu is provided by Gm by the action of the processing unit 25. The operator selects a processing mode, a processing condition, and the like described later based on the processing processing menu. &lt;Alignment Operation&gt; In the laser processing apparatus 50, the alignment operation of the arrangement position of the workpiece 10 can be finely adjusted in the observation unit _ before the processing. Alignment action

The processing is performed in such a manner that the γ coordinate axis of the gamma coordinate is matched with the seat W of the stage 7. In the case of performing the processing of the above-described processing pattern (4), the alignment processing is important in satisfying the specific orientation required for each processing pattern so that the crystal orientation of the workpiece, the predetermined processing line, and the scanning direction of the laser light are satisfied. 156646.doc -37- 201221261 Alignment action can be applied to the week. Technology 仃 can be carried out according to the processing pattern. For example, if it is for use! When a plurality of device dies made by a mother substrate are cut in a case where a repeating pattern is formed on the surface of the workpiece, the alignment operation can be realized by using pattern matching or the like. In this case, roughly, the coffee camera or the W acquires the captured image of the plurality of alignment marks formed on the workpiece 1 , and the processing unit 25 determines the relative position of the captured image based on the captured image. The alignment amount is specified in the sexual relationship, and the drive control unit Kawasaki moves the reading stage 7 by the moving mechanism 7 according to the alignment amount, thereby achieving alignment. By performing this alignment operation, the processing position in the processing can be specified on the disk. Further, after the alignment operation is completed, the stage 7 on which the workpiece 1 is placed is moved to the laser light irradiation unit 50A, and then processed by irradiation of the laser light. Further, the movement of the carrier 7 from the observation portion 5〇b to the laser beam irradiation unit 50A is ensured so that the predetermined processing position set at the time of the alignment operation does not deviate from the actual machining position. &lt;Summary of Processing Process&gt; Next, the processing of the laser processing apparatus 5A of the present embodiment will be described. In the laser processing apparatus 50, by the combination of the irradiation of the laser light lb emitted from the laser light source and creased by the optical system 5, and the movement of the stage 7 on which the workpiece 10 is placed and fixed, the optical processing can be performed while being optically The laser light B of the system is processed by the workpiece (7) while being scanned relative to the workpiece 1 。. Specifically, you can do the above! The processing drawing is performed until the third processing pattern is opened/cleaved. In the case of processing in the first processing pattern, as for the predetermined processing line l 156646.doc •38· 201221261 parallel to the direction of the valley open/cracking, the side which is easy to open/split (4):::Processing 1〇' so that it is predetermined to add 1〇: line alignment, and scanning by the laser beam LB on the pre-processing line L of the workpiece. As for the processing company:: the direction of the easy phase/cracking direction is set vertically. The direction is orthogonal to the direction of movement of the stage 7. The second workpiece is aligned with 0, and by laser light (10) When the third processing pattern is processed, the workpiece 1 is processed so that the predetermined processing line 成为 becomes the equivalent position with respect to the two split/split directions. Aligning and alternately moving the stage 7 in such a manner that the scanning of the laser light LB is alternately performed in each of the split/split directions. Alternatively, when processing in the third processing mode, A line La parallel to the predetermined processing line L as shown in FIG. Alternatively, along the pre-processing line L itself, a plurality of laser beams are scanned substantially or hypothetically. Further, a plurality of laser scanning means are hypothetically irradiated with laser light by one optical path. The optical path is temporally changed, thereby realizing the same scanning pattern as in the case of irradiating the laser light with a plurality of optical paths. Further, even in the case of any of the processed patterns, the optical path length difference AL can be appropriately set. The delay time D is set to a value equal to or less than about 2 times the pulse width, so that the split beam processing can be preferably performed. [Simple description of the drawing] 156. 156646.doc •39· 201221261 圏)) to (4) is modewise Fig. 2 showing the processing form of the mth pattern is an optical microscope image of the surface of the workpiece to be processed by the first cutting edge by splitting with the second processing pattern. 2 = 3 by the first processing pattern The processing is performed to form a blue of the starting point of the division: the earning map; 4 from the surface (C surface) after the division starting point is divided to the sectional view 4 (a) to (4) schematically showing the processing pattern of the second processing pattern. " Figure 5 is the same as the second processing vte - &gt; «Raku 2 into the prescribed processing pattern of cleavage / cleavage processed to form an optical microscope image of the surface with a division start point of the workpiece. Fig. 6 is an SEM image of a self-surface (c-plane) to a cross-section of a sapphire c-plane substrate having a division starting point formed along the division starting point by processing of the second processing pattern. Fig. 7 (a) and (b) are diagrams schematically showing the processing form of the third processing pattern. Fig. 8 is a view showing the relationship between a predetermined processing line of the third processing pattern and a predetermined formation position of the irradiated area. Fig. 9 is a view schematically showing a change in intensity distribution of laser light actually irradiated to a workpiece when the delay time is different. Fig. 10 is a view showing the intensity distribution of the laser light when the delay time is about twice the half value width of the unit pulse light, but the peak intensity of the second half pulse light H2 is smaller than the peak intensity of the first half pulse light (1). Fig. 11 is a schematic view showing the configuration of 156646.doc - 40 - 201221261 of the laser processing apparatus 50 of the present embodiment. Fig. 12 is a schematic view showing the configuration of the optical system 5. [Description of main components] 1 Controller 2 Control unit 3 Storage unit 3p Program 4 Fixed sheet 5 Optical system 5a Lens 5b Attenuator 6 Front view mechanism 6a ' 16a CCD camera 6b, 16b Monitor 7 Stage 7m Movement mechanism 10 Workpiece 10a (to-be-processed object) mounting surface 11 suction mechanism 16 back surface observation mechanism 18 condensing lens 19 half lens 21 drive control unit 22 imaging control unit 156646.doc - 41 - 201221261 23 24 25

50 50A 50B 51 52 53 54 55 56 AR1

Cl to C3, Clla to C14b, C21 to C24

Cpl to CP3

D D1 D2

HI H2

II, 12 L LI to L4 Irradiation control unit Adsorption control unit Processing unit Laser processing device Laser beam irradiation unit Observation unit Beam expander Objective lens Branch lens Synthetic lens Optical path length Adjustment mechanism Focus adjustment lens system Arrow treatment/solution Surface Synthetic Pulse Light Delay Time Processing Position Data Processing Mode Setting Data 1st Half Pulse Light 2nd Half Pulse Light Peak Intensity Scheduled Processing Line Epi-Illumination Light 156646.doc -42· 201221261 LB Laser Light LB1 1st Laser Light LB2 2nd Laser light La ' Lp Straight OP optical path OP1 First branch optical path OP2 Second branch optical path P21 to P25 Predetermined formation positions RE, RE1 to RE4, RE11 to REI5, illuminated areas RE21 to RE25 SI to S4 Falling illumination source SL Laser source UP, UP3a, UP3b unit pulse light W1, W2, W2a, W2b, weak intensity portion Wlla, W12a, W11b, W12b ' Wile ' W12c ω , ω1 , ω2 Half value width 156646.doc 43

Claims (1)

201221261 VII. Patent application scope: 1. A laser processing apparatus i, characterized in that: a light source 'which emits pulsed laser light; and a stage 'which carries a workpiece; and the pulsed laser light pulse width is Ultra-short pulse light of the psec level; the optical path of the pulsed laser light from the light source to the stage is partially branched in the middle! The optical path and the second optical path are connected to each other; the laser processing device further includes an optical path length that changes to an optical path length of the second optical path; and the pulse laser light defined by the light source is branched from the first a first laser light that advances in the optical path and a second laser light that advances in the second optical path and the unit pulse light of the pulsed laser light is branched into a unit pulse light that is a unit pulse light of the first laser light and In the second half-pulse light, which is the unit pulse light of the second laser beam, the optical path length adjusting means sets the second half-pulse light more delayed than the first half-pulse light in the optical path after the merged light. The optical path of the second optical path is long; and when the workpiece is placed on the stage, the pulsed laser light is irradiated onto the workpiece while the stage is moved, and the respective units are The second half pulse light of the pulsed light and the irradiated area of the second half pulse light are substantially identical in the processed surface of the workpiece, and are added as described above. Discretely forming the irradiated region of the light pulse of the above-described various units of the processed surface thereof. 156646.doc 201221261 2. The laser processing apparatus of claim 1, wherein the optical path length adjusting mechanism delays the second half pulse light by only one-half of a half value width of the unit pulse light with respect to the first half pulse light The optical path length of the second optical path is set by the method of delay time of 3 times or more and 1 〇 nsec or less. 3. The laser processing apparatus of claim 2, further comprising: an intensity adjustment mechanism for adjusting the intensity of the second laser light; and the optical path length adjustment mechanism to cause the second half pulse light to be optical only with respect to the first half pulse light Setting an optical path length of the second optical path by delaying a delay time equal to or larger than a half value width of the unit pulse light; and the intensity adjusting mechanism is configured to make the intensity of the second laser light smaller than the first thunder The intensity of the second laser light is adjusted in such a manner as to increase the intensity of the light. 4. The laser processing apparatus according to claim 2, further comprising: a focus adjustment mechanism for adjusting a focus of said second laser light; said optical path length adjustment mechanism for causing said second half pulse light to be said only with respect to said first half pulse light Setting an optical path length of the second optical path by delaying a delay time equal to or larger than a half value width of the unit pulse light; and the focus adjustment mechanism is configured to increase a beam diameter of the second laser beam; The focus of the second laser light is adjusted in such a manner that the beam diameter of the field light is emitted. The processing method of the workpiece is characterized in that it is used for the processing method of the workpiece = the starting point of the division, and includes: • a step of 'ultra-short pulse light with a pulse width of psec of 156646.doc The light path of the pulsed laser light source of 201221261 to the stage on which the workpiece is placed is set to be partially branched into the second light path and the second light path in the middle and merged thereafter; the optical path length adjustment step is defined as being emitted from the light source The pulse laser light branch is a second laser light that advances in the first optical path and a second laser light that advances in the second optical path, and the unit pulse light of the pulsed laser light branches into the first When the unit pulsed light of the laser light is the second half pulse light, which is the unit pulse light of the second laser light, the second half pulse light is made higher than the above! The half pulse light is further delayed to set the optical path length of the second optical path; the placing step is to place the workpiece on the stage; and the irradiating step is such that the first half of each unit pulse light is The pulsed light is irradiated to the irradiated region of the second half-pulse light, and the irradiated region of the unit pulse light is discretely formed on the processed surface of the workpiece, and the pulsed laser light is irradiated to The workpiece is thereby subjected to processing or cleavage of the workpiece between the irradiated regions, thereby forming a starting point for dividing the workpiece. 6. The method of processing a workpiece according to π, wherein, in the optical path length adjusting step, the second half pulse light is delayed by a half value of the unit pulse light with respect to the third half pulse light. The optical path length of the second optical path is set to be 1/3 times or more and the delay time of the second optical path is set. 7. The processing method of the workpiece according to claim 6 further includes adjusting the second The intensity adjustment step of the intensity of the laser light; in the optical path length adjustment step, the second half pulse optical phase 156646.doc 201221261 is delayed by only one times the half value width of the unit pulse light for the ith half pulse light The optical path length of the second optical path is set to be longer than the delay time of 2 times or less; and the second adjustment is performed so that the intensity of the second laser light is smaller than the intensity of the first laser light in the intensity adjustment step The method for processing a workpiece according to Item 6, further comprising a focus adjustment step of adjusting a focus of the second laser light; wherein in the optical path length adjustment step, r is oblique at w The second half-pulse light is delayed by only one time U of the half-value width of the soap-level pulse light with respect to the second half-pulse light, and the optical path length of the optical path is delayed by two times or less; (4) the second aspect is set In the focus adjustment step, the second laser light diameter is larger than the focus of the first laser light laser light. The second light is adjusted according to any one of the claims 5 to 8. The processing method of the workpiece ^V is such that the above-mentioned broken material is easily opened or split-formed by a different ui on the upper side of the if〇D; the early pulse irradiation area. At least two of them are formed. 10. The processing method of the workpiece according to claim 9, the workpiece is easily opened or split, and the middle portion is along the above-mentioned added region. ° All of the above-mentioned irradiated &quot; The two processing methods of the workpiece according to Item 9 are alternately formed in the direction in which the processing is easy to open or split, and 156646.doc 201221261 is formed to form at least two of the irradiated regions. Such as The processing of the workpiece according to any one of claims 5 to 8 forms the irradiated region 13 in a direction that is equal to the two different directions of the workpiece, and the method of dividing the workpiece. And the method of the object, and the method of dividing the workpiece processed by the method of any one of claims 5 to 12 along the segmentation starting point, wherein the system is opened or split The segmentation is added to form a segmentation 156646.doc