JP2015162565A - Substrate with led pattern, method for manufacturing the same, and method for manufacturing led element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate with an LED pattern and a method for manufacturing the same which can obtain an LED element more excellent in light extraction efficiency than conventional.SOLUTION: A method for manufacturing a substrate with an LED pattern includes: a step that a scribe line is formed by performing laser scribing along a planned division position defined on one main surface of a wafer; and a step that an LED pattern that repeats a unit pattern two-dimensionally each of which composes one LED element is formed on the laser-scribed side of the main surface. In the scribing step, the scribe line is formed as an arrangement of a plurality of processing marks discretely present along the planned division position inside the wafer, and a crack is extended between the scribe line and the main surface.

Description

  The present invention relates to a substrate with an LED pattern, a method for manufacturing the same, and a method for manufacturing an LED element.

  In general, an LED element is formed by repeatedly forming a unit pattern of an LED element made of a group III nitride semiconductor layer such as GaN or a metal electrode on a substrate (wafer, mother substrate) such as a sapphire single crystal in two dimensions. A substrate with a pattern (a substrate with an LED pattern) is manufactured by a process of dividing the substrate into divided regions called streets provided in a grid and dividing the substrate into chips (chips). Here, the street is a narrow area that is a gap between two parts that become LED elements by division.

  A substrate with a pattern is formed on a wafer with a buffer layer made of a group III nitride, an n-type conductive layer (also called an n-type cladding layer, an n-type contact layer, etc.), a light emitting layer, a p-type conductive layer ( p-type cladding layer, p-type contact layer, etc.) are stacked, and then a p-electrode and an n-type conductive layer are exposed on the p-type conductive layer, and an n-electrode is formed on the exposed surface. (For example, refer to Patent Documents 1 to 3).

  In addition, as a technique for division, laser light that is ultrashort pulse light having a pulse width of the order of psec is irradiated under the condition that the irradiated area of each unit pulse light is discretely positioned along the planned processing line. By doing so, a method of forming a starting point for division along a planned processing line (usually a street center position) is already known (see, for example, Patent Document 4). In the technique disclosed in Patent Document 4, crack extension (crack extension) is generated by cleaving or cleaving between the processing marks formed in the irradiated regions of each single pulse light, and the substrate is moved along the crack. By dividing (breaking), singulation is realized.

Japanese Patent Laid-Open No. 10-200215 JP 2012-64811 A JP 2010-225787 A JP 2011-131256 A

  In the case of the technique disclosed in Patent Document 4, the singulation is performed on a substrate with a pattern on which a unit pattern constituting an LED element is formed on a wafer. This is performed in a mode in which light is irradiated. Ideally, the crack extension during singulation should occur perpendicular to the substrate surface, but according to the conventional procedure, the group III nitride semiconductor layer cracked obliquely during the division, and other than the street In some cases, the III-nitride semiconductor layer of the element constituent part is damaged. Such damage reduces the light extraction efficiency of the LED element.

  Further, depending on the LED element to be manufactured, the chip size, the layer configuration (material, thickness, etc.) of the substrate with the pattern, the street width, and the like vary, and the division needs to be performed well in each layer. For this reason, there are problems that processing restrictions are large and it is difficult to set processing conditions.

  On the other hand, when normal division is performed, the side surface of the group III nitride semiconductor layer in the obtained individual pieces (LED elements) is a flat surface without unevenness, so that the light from the light emitting layer is not emitted. The light is reflected at the side surface and is not easily emitted to the outside of the element. This is not preferable from the viewpoint of further increasing the light extraction efficiency of the LED. Although a technique called SWE (side wall etching) in which etching is performed on the side surface is also envisaged, such a technique is not preferable because it may corrode or damage the group III nitride semiconductor layer.

  In addition, ODR (Omni-Directional Reflector) and DBR (Distributed Bragg Reflector) are provided on the irradiated surface, which is the opposite side of the surface on which the unit pattern is formed, with a metal thin film. Therefore, there is a problem that it is difficult to perform good division.

  This invention is made | formed in view of the said subject, and it aims at providing the board | substrate with an LED pattern which can obtain the LED element which was excellent in the light extraction efficiency conventionally, and its manufacturing method.

  In order to solve the above-mentioned problems, the invention of claim 1 is a method of manufacturing a substrate with an LED pattern, wherein a laser is applied to the wafer along a predetermined division position defined in a lattice shape on one main surface of the wafer. A scribe process for forming a scribe line by scribing, and an LED for forming an LED pattern that two-dimensionally repeats unit patterns each constituting one LED element on the main surface of the wafer that has undergone the scribe process. Forming a pattern, and in the scribing step, the scribe line is formed as an array of a plurality of processing traces that are discretely present along the planned division position inside the wafer, and the scribe line And a crack extending between the main surface and the main surface.

  Invention of Claim 2 is a manufacturing method of the board | substrate with an LED pattern of Claim 1, Comprising: In the said scribing process, the pulse width is 200 fsec-100 psec, the focus position is the said position of the said wafer By irradiating while irradiating each single pulsed light of the pulsed laser light in a state of being inside the wafer while scanning under a condition in which the regions to be divided are distributed along the extending direction of the division planned position, the scribe line Is formed.

  Invention of Claim 3 is a manufacturing method of the board | substrate with an LED pattern of Claim 2, Comprising: In the said scribe process, the beam diameter of the said pulse laser beam in the said focus position is 0.25 micrometer-2.0 micrometers. The scribe line is formed so that a maximum depth of the lowermost end portion of the processing mark from the main surface of the wafer is 15 μm to 50 μm.

  The invention of claim 4 is a method of manufacturing an LED element, wherein the substrate with LED pattern is manufactured by the method for manufacturing a substrate with LED pattern according to any one of claims 1 to 3. And an individualization step of obtaining a plurality of LED elements by dividing the substrate with the LED pattern obtained by the substrate manufacturing step into pieces by breaking along the scribe line.

  According to the invention of claim 5, an LED pattern formed by two-dimensionally repetitively forming unit patterns each constituting one LED element is provided on one main surface of the wafer and is divided at a predetermined division position. A substrate with an LED pattern on which a large number of LED elements are manufactured, and a scribe line in which a plurality of processing traces are arranged discretely along the planned division position is formed inside the wafer. In addition, a crack is extended between the scribe line and the main surface.

  According to the first to fifth aspects of the present invention, an LED element having excellent light extraction efficiency can be obtained at a higher yield than the conventional one.

2 is a schematic cross-sectional view showing the structure of an LED element 10. FIG. 3 is a cross-sectional view schematically showing a state in the middle of manufacturing the LED element 10. FIG. It is a figure for demonstrating a laser scribe. It is a figure which illustrates the structure of the laser processing apparatus 100 used for a laser scribe. It is a figure which shows roughly about the mode of individualization by the break apparatus. It is a figure for demonstrating a modification.

<LED element and its production procedure>
FIG. 1 is a schematic cross-sectional view showing the structure of an LED element 10 which is a production target of the manufacturing method according to the present embodiment. The LED element 10 has an undoped layer 2, an n-type layer 3, a light emitting layer 4, each made of GaN, AlN or InN, or a group III nitride that is a mixed crystal thereof, on the sapphire substrate 1. A p-type layer 5 is epitaxially grown in this order, and a p-type electrode 6 is provided on the p-type layer 5, and an n-type electrode 7 is formed in an electrode formation region 7 a in which a part of the n-type layer 3 is exposed. It has the composition provided with. Note that each of the undoped layer 2, the n-type layer 3, the light-emitting layer 4, and the p-type layer 5 is not limited to a single layer, and may be configured by stacking a plurality of layers.

  For example, the undoped layer 2 is exemplified by a GaN layer having a thickness of about 1.5 μm to 3 μm (for example, 2 μm). Further, the n-type layer 3 may be provided with a contact layer, a clad layer, and the like. Examples of the n-type layer 3 include a GaN layer having a film thickness of about 1.5 μm to 3 μm (for example, 2 μm). The light emitting layer 4 may be configured to have, for example, a multiple quantum well structure. The light emitting layer 4 includes a first unit layer (barrier layer) made of GaN and having a thickness of about 8 nm to 15 nm (for example, 10 nm) and a second unit layer made of GaInN and having a thickness of about 2 nm to 4 nm (for example, 3 nm). An example is a multiple quantum well active layer that is repeatedly and alternately stacked. By changing the InN molar fraction of the second unit layer, the emission wavelength can be changed in the range of 380 nm to 620 nm. Furthermore, the p-type layer 5 may be configured to include an electron block layer, a contact layer, and the like. The p-type layer 5 includes a p-AlGaN layer having a film thickness of about 15 nm to 25 nm (for example, 20 nm), a p-GaN layer having a film thickness of about 90 nm to 200 nm (for example, 150 nm), and a film thickness of about 8 nm to 15 nm. A configuration in which a p-GaN contact layer (for example, 10 nm) is stacked is exemplified.

  Further, an ODR (Omni-Directional Reflector) or DBR (Distributed Bragg Reflector) made of a metal thin film is formed on the main surface opposite to the main surface on which the above-mentioned layers of the wafer W are formed. (Distributed Bragg Reflector) may be provided.

  FIG. 2 is a cross-sectional view schematically showing a state in the process of manufacturing the LED element 10. In the present embodiment, a substrate (LED pattern) provided with an LED pattern PT formed by two-dimensionally repeating unit patterns constituting each LED element 10 on a wafer W made of single crystal sapphire. Manufactured with a so-called multi-chip process in which a substrate is attached to a division area called a street ST (see FIG. 3) provided in a lattice shape and divided into chips (chips). It shall be.

  In manufacturing the LED element 10 in this manner, first, as shown in FIG. 2A, a wafer W is prepared. The thickness of the wafer W to be prepared is preferably about 380 μm to 430 μm.

  Next, a scribe line SL is formed on the wafer W by laser scribe. Laser scribing is a process for forming a scribe line SL by irradiating the pulse laser beam LB while scanning it along the scheduled division position A set in advance on the one main surface (front surface) Wa side of the wafer W in advance. It is.

  FIG. 3 is a diagram for explaining the laser scribe. First, FIG. 3A is a partially enlarged view of the main surface Wa of the wafer W that is the target of laser scribing. In FIG. 3A, the position that becomes the street ST in the wafer W is indicated by a broken line. Yes. More specifically, a position in the vicinity of one intersection of streets ST extending in two orthogonal directions is shown. Here, the street ST is a narrow region that is a gap portion between two portions that become the LED elements 10 by division, in which the center position in the width direction matches the planned division position A, and the main surface Wa of the wafer W. Is defined in a lattice shape over substantially the entire surface.

  For confirmation, the street ST as shown in FIG. 3A is not provided in the actual wafer W, and the position to be the street ST is determined for pattern design. Only.

  FIG. 4 is a diagram illustrating the configuration of the laser processing apparatus 100 used for laser scribing.

  The laser processing apparatus 100 mainly includes a stage 101 for placing the wafer W thereon, and a controller 110 for controlling various operations (observation operation, alignment operation, processing operation, etc.) of the laser processing apparatus 100. By irradiating the wafer W placed on the wafer W with pulsed laser light (also simply referred to as laser light) LB emitted from the laser light source LS, various processing can be performed on the wafer W. Yes.

As the laser light source LS, an Nd: YAG laser is preferably used. Alternatively, an embodiment using an Nd: YVO ₄ laser or other solid-state laser may be used. Furthermore, the laser light source LS is preferably provided with a Q switch.

  As will be described later, the pulse width of the laser beam LB is set to any value in the order of fsec (femtoseconds) to psec. Also. The wavelength of the laser beam LB may be any wavelength of 200 nm to 1100 nm, but preferably belongs to the wavelength range of 200 nm to 563 nm. In particular, when an Nd: YAG laser is used as the laser light source LS, its third harmonic It is a preferred embodiment to use (wavelength of about 355 nm). The pulse repetition frequency is preferably 10 kHz or more and 200 kHz or less.

  Details of the laser processing apparatus 100 will be described later.

  FIG. 3B is a diagram illustrating a state after laser scribing is performed on the wafer W illustrated in FIG. In the present embodiment, a large number of machining marks P that are discretely arranged along the extending direction of the planned division position A as shown in FIG. That is, in the present embodiment, the arrangement of the processing marks P forms a scribe line SL. Moreover, the array of the processing marks P is formed inside the wafer W as shown in FIG.

  Formation of the scribe line SL (arrangement of the processing marks P) in such a mode is performed by irradiating and scanning with the laser beam LB having a pulse width of the order of fsec to psec, and focusing on the wafer W instead of the main surface Wa of the wafer W. In the defocused state intentionally shifted to the inside of the laser beam LB, the irradiated area of each single pulse light of the laser beam LB extends along the extending direction of the planned division position A (extending direction of the street ST). This is realized by performing the process under discrete conditions. Such an irradiation region can be dispersed by appropriately adjusting the repetition frequency and the relative movement speed with respect to the wafer W.

  When the laser beam LB is irradiated under such conditions, the irradiation area of each unit pulse beam of the laser beam LB (a region near the in-focus position F of each unit pulse beam) inside the wafer W. In sapphire, sapphire melts and expands locally and instantaneously, and a minute altered region is formed through subsequent shrinkage and resolidification. Such an altered region is a processing mark P.

  In addition, when forming the processing mark P in such a mode, as shown in FIG. 2B, local and instantaneous melting / expansion occurs in the irradiation region of the unit pulse light. , Crack CR extends from each processing mark P.

  The crack CR extends in the thickness direction of the wafer W (perpendicular to the main surfaces Wa and Wb of the wafer W), and also along the extending direction of the division planned position A (extending direction of the street ST). Extend. Among these, the crack CR1 that is directed to the main surface Wa side of the wafer W with a small distance from the processing mark P substantially reaches the main surface Wa of the wafer W. On the other hand, since the distance from the formation position of the processing mark P to the other main surface (back surface) Wb of the wafer W is sufficiently larger than the distance to the main surface Wa, the crack CR2 toward the main surface Wb is Usually, it stays in the middle of the wafer W as shown in FIG.

  Since no gap is formed at the crack CR, the flatness on the main surface Wa of the wafer W remains maintained.

  The size of the processing mark P is about 0.5 μm to 2.0 μm in the in-plane direction of the wafer W, and preferably about 10 μm to 30 μm in the thickness direction of the wafer W. Further, it is preferable that the processing mark P is formed so that the maximum depth of the lowermost end portion is at a position of about 15 μm to 50 μm from the main surface Wa of the wafer W. Furthermore, the pitch of the processing marks P is preferably about 1 μm to 10 μm. In order to meet these requirements, the substrate W1 with the LED pattern (FIG. 2C) manufactured using the wafer W is preferably divided along the scribe line SL where the processing marks P are arranged in a subsequent process, and separated into individual pieces. I can do it.

  The scribe line SL is formed in this manner by setting the pulse width of the laser beam LB to 200 fsec to 100 psec, the beam diameter of the laser beam LB at the in-focus position F to 0.25 μm to 2.0 μm, and the main surface of the wafer W. The distance (defocus value) from Wa to the in-focus position F is 5 μm to 45 μm, the repetition frequency of the laser light LB is 50 kHz to 100 kHz, and the scanning speed of the laser light LB with respect to the wafer W is 100 mm / sec to 500 mm / sec. It is realized by doing.

  Preferably, prior to the formation of the scribe line SL, an alignment mark is formed on the surface of the wafer W where the scribe line SL is formed by an appropriate method. This is performed after aligning the wafer W by using it. The alignment mark can also be formed using the same laser processing apparatus 100 as laser scribe.

  After the scribe line SL is formed at a desired position by laser scribe, an LED pattern PT is formed on the main surface Wa of the wafer W as shown in FIG. That is, after the low-temperature buffer layer is formed, the group III nitride layer (crystal layer) that becomes the undoped layer 2, the n-type layer 3, the light emitting layer 4, and the p-type layer 5 is epitaxially grown. Formation of the p-type electrode 6 on the surface of the mold layer 5, formation of the electrode formation region 7a by exposing a part of the n-type layer 3, and formation of the n-type electrode 7 on the electrode formation region 7a Is done.

  Conventionally, the LED pattern PT is formed before laser scribing, but in the present embodiment, the LED pattern PT is formed after laser scribing.

  Various known epitaxial growth techniques can be applied to the epitaxial growth of the group III nitride layer. For example, it can be performed by a technique such as MOCVD (metal organic chemical vapor deposition) or MBE (molecular beam epitaxy). The actual epitaxial growth conditions (wafer temperature, raw material composition, raw material gas flow rate, raw material gas pressure, growth time, etc.) when each growth method is used are the undoped layer 2, n-type layer 3, and light emitting layer 4 to be formed. , And the composition and thickness of the p-type layer 5.

  For forming the p-type electrode 6 and the n-type electrode 7, various thin film forming methods such as vapor deposition and sputtering can be suitably used. The electrode material may be appropriately selected from various metal materials such as Ni, Pd, Pt, Au, and Al. Alternatively, the p-type electrode 6 and the n-type electrode 7 may be provided as a multilayer electrode in which metal layers having different compositions are laminated.

  Also, a known etching process or photolithography process can be applied to the formation of the electrode formation region 7a.

  Through the procedure as described above, a substrate W1 with an LED pattern formed by forming the LED pattern PT on the wafer W is obtained. In other words, the substrate W1 with the LED pattern according to the present embodiment is provided with the scribe line SL in which the processing marks P are arranged inside the wafer W and the one main surface Wa (LED pattern) of the wafer W. It can be said that a crack CR is provided between the PT forming surface) and the scribe line SL.

  Note that the wafer W is heated during the epitaxial growth of the group III nitride layer described above. The heating temperature at that time varies depending on the composition of the layer to be formed, etc., but is generally about 600 ° C. to 1200 ° C. When the wafer W is heated in such a manner, stress is generated in the wafer W. Then, when the stress acts, the crack CR2 formed from the scribe line SL toward the main surface Wb further extends toward the main surface Wb. The extension of the crack CR has an effect of making it easier to break during the subsequent singulation. In this case, the extension of the crack usually does not reach the time when the wafer W is divided as in the case of forming the scribe line SL. Alternatively, the formation depth of the processing mark P may be determined in anticipation of the extension of the crack CR due to heating during the epitaxial growth.

  Next, division (separation) of the substrate W1 with the LED pattern will be described. FIG. 5 is a diagram schematically showing how the individual pieces are separated by the break device 200.

  Prior to the division, the main surface Wb (the main surface on the side where the LED pattern PT is not formed) of the wafer W may be polished to reduce its thickness.

  The break device 200 is a device that breaks an object using a three-point support method. The break device 200 includes one upper break bar 201 and two lower break bars 202. The upper break bar 201 is a columnar member having a triangular cross section or an isosceles trapezoidal cross section, and the lower break bar 202 is a plate member.

  At the time of separation, the upper break bar 201 is positioned above the main surface Wb of the wafer W in a state where the LED pattern substrate W1 is horizontally supported so that the LED pattern PT is on the lower side and appropriately positioned. A position just above the planned division position A is arranged in parallel with the planned division position A, and the two lower break bars 202 are arranged at positions below the LED pattern PT and symmetrical to the planned division position A. Then, the upper break bar 201 is brought into contact with the main surface Wb immediately above the scheduled division position A, and the two lower break bars 202 are brought into contact with the LED pattern PT while being symmetrical with respect to the planned division position A. Let Due to the stress acting thereon, the crack CR as shown in FIG. 2C (particularly the crack CR2) is in the vertical direction (the thickness direction of the substrate W1 with the LED pattern perpendicular to the main surfaces Wa and Wb of the wafer W). Towards the extension. As a result, the substrate W1 with LED pattern can be favorably divided (broken) along the scribe line SL.

  By sequentially performing breaks on all the scribe lines SL, a large number of LED elements 10 can be obtained as shown in FIG.

  Prior to dividing the substrate W1 with LED pattern, an ODR (Omni-Directional Reflector) or DBR (Distributed Bragg Reflector) is formed of a metal thin film on the other main surface Wb of the wafer W. However, according to the present embodiment, even in such a case, a good break can be performed.

<Effects of performing laser scribing in advance>
As described above, in the present embodiment, after the scribe line SL is formed on the wafer W by laser scribing, the LED pattern PT is formed, and then the LED element 10 is obtained by dividing into pieces. Yes. Hereinafter, the effect of producing the LED element 10 according to the procedure will be described.

  First, when laser scribing is performed after the LED pattern PT is formed as in the prior art, there is a possibility that the LED pattern PT is damaged by the laser beam LB. Since laser scribing is performed in the state where PT is not formed, the LED pattern PT is not damaged.

  Second, in the case of the conventional procedure, in order to avoid the influence of the laser beam LB on the LED pattern PT as much as possible, laser scribing is performed with the main surface Wb opposite to the main surface Wa on which the LED pattern PT is formed as the irradiated surface. As a result, the crack extending from the scribe line SL at the time of the break reaches the LED pattern PT, and the LED pattern PT may be divided instead of the street ST. In the case of the form, since laser scribing is performed from the main surface Wa side before the formation of the LED pattern PT, the LED element 10 can be obtained with a high yield because there is no division at the LED pattern PT. I can do it.

  Third, in the case of the conventional procedure, the street ST is irradiated with the laser beam LB in a state where the street ST is physically partitioned as a narrow region by the LED pattern PT. Although the restrictions were large, in the case of the present embodiment, although the position of the street ST is fixed, the actual processing target is the wafer W in which the LED pattern PT does not exist, and thus the degree of freedom in setting processing conditions is high. Thus, laser scribing can be performed under more suitable conditions.

  Fourth, it is difficult to produce an LED element having an ODR or DBR made of a metal thin film by the above-described conventional procedure because the metal thin film reflects laser light. In the case of the embodiment, since laser scribing is performed before forming the metal thin film, an LED element having ODR and DBR and having excellent light extraction efficiency can be produced without any problem.

  By obtaining the above effects, according to the present embodiment, an LED element having excellent light extraction efficiency can be obtained with a higher yield than conventional.

<Detailed configuration of laser processing equipment>
Finally, a detailed configuration of the laser processing apparatus 100 shown in FIG. 4 will be described. As described above, the laser processing apparatus 100 mainly includes the stage 101 on which the wafer W is placed, and the controller 110 that controls various operations of the laser processing apparatus 100.

  The stage 101 is movable in the horizontal direction by the moving mechanism 102. The moving mechanism 102 moves the stage 101 in a predetermined XY 2-axis direction within a horizontal plane by the action of a driving unit (not shown). Thereby, the movement of the laser beam irradiation position and the like are realized. The moving mechanism 102 can also perform a rotation (θ rotation) operation in a horizontal plane around a predetermined rotation axis independently of horizontal driving.

  Further, in the laser processing apparatus 100, surface observation for directly observing the wafer W from the side irradiated with the laser light through an imaging unit (not shown), or observation through the stage 101 from the side placed on the stage 101 is performed. You can perform backside observation.

  The stage 101 is formed of a transparent member such as quartz, and a suction pipe (not shown) serving as an intake passage for adsorbing and fixing the wafer W with the adhesive protection sheet AS attached to the main surface Wb is disposed inside the stage 101. Is provided. The suction pipe is provided, for example, by drilling a predetermined position of the stage 101 by machining.

  In a state where the wafer W to which the adhesive protection sheet AS is stuck is placed on the stage 101, the suction pipe is sucked by the suction means 103 such as a suction pump, for example, and the suction pipe is placed on the stage 101 placement surface side. The wafer W (and the adhesive protective sheet AS) is fixed to the stage 101 by applying a negative pressure to the suction hole provided at the tip.

  More specifically, in the laser processing apparatus 100, the laser light LB is emitted from the laser light source LS, reflected by a dichroic mirror 104 provided in a lens barrel (not shown), and then the laser light LB is converted into the stage 101. Then, the light is condensed by the condenser lens 105 so as to be focused on the part to be processed of the wafer W placed on the wafer W and irradiated onto the wafer W. The laser beam LB is emitted to the wafer W using the condenser lens 105 as a direct emission source. By combining the irradiation of the laser beam LB and the movement of the stage 101, the wafer W can be processed while the laser beam LB is scanned relative to the wafer W.

  In the laser processing apparatus 100, it is also possible to irradiate the laser beam LB in a defocused state in which the in-focus position is intentionally shifted from the surface of the wafer W as necessary during processing. Yes.

As the laser light source LS, an Nd: YAG laser is preferably used. Alternatively, an embodiment using an Nd: YVO ₄ laser or other solid-state laser may be used. Furthermore, the laser light source LS is preferably provided with a Q switch.

  Further, adjustment of the wavelength and output of the laser light LB emitted from the laser light source LS, the pulse repetition frequency, the pulse width, and the like are realized by the irradiation control unit 123 of the controller 110. When a predetermined setting signal according to the processing mode setting data D2 is issued from the processing unit 125 to the irradiation control unit 123, the irradiation control unit 123 sets the irradiation condition of the laser beam LB according to the setting signal.

  It is preferable that the laser beam LB is radiated while being focused to a beam diameter of about 0.25 μm to 2.0 μm by the condenser lens 105.

  The polarization state of the laser light LB emitted from the laser light source LS may be circularly polarized light or linearly polarized light. Further, when the emitted light is linearly polarized light, the laser processing apparatus 100 preferably includes an attenuator (not shown). The attenuator is disposed at an appropriate position on the optical path of the laser beam LB and plays a role of adjusting the intensity of the emitted laser beam LB.

  The controller 110 controls the operation of each unit described above and is referred to in the control unit 120 that realizes the processing of the wafer W in various modes, the program 130P that controls the operation of the laser processing apparatus 100, and processing. And a storage unit 130 for storing various data.

  The control unit 120 is realized by a general-purpose computer such as a personal computer or a microcomputer, for example, and various components can be obtained by the program 130P stored in the storage unit 130 being read and executed by the computer. Is realized as a functional component of the control unit 120.

  Specifically, the control unit 120 includes a drive control unit 121 that controls operations of various drive parts related to processing such as driving of the stage 101 by the moving mechanism 102 and focusing operation of the condensing lens 105, and the like. An imaging control unit 122 that controls imaging of the wafer W by the imaging unit that does not perform, an irradiation control unit 123 that controls irradiation of the laser light LB from the laser light source LS, and an operation of attracting and fixing the wafer W to the stage 101 by the suction unit 103 Are mainly provided with a suction control unit 124 that controls the processing and a processing unit 125 that executes processing to the processing target position in accordance with the given processing position data D1 and processing mode setting data D2.

  The storage unit 130 is realized by a storage medium such as a ROM, a RAM, and a hard disk. The storage unit 130 stores processing position data D1 describing the formation position of the scribe line SL on the wafer W, and conditions for individual parameters of the laser light and driving conditions of the stage 101 according to the processing mode ( Alternatively, machining mode setting data D2 describing such settable ranges) is stored. The storage unit 130 may be implemented by a computer component that implements the control unit 120, or may be provided separately from the computer, such as a hard disk.

  Various input instructions given by the operator to the laser processing apparatus 100 are preferably performed using a GUI realized in the controller 110. For example, a processing menu is provided on the GUI by the operation of the processing unit 125.

  In the laser processing apparatus 100 having the above-described configuration, the processing unit 125 acquires the processing position data D1 and the processing conditions corresponding to the selected processing mode from the processing mode setting data D2, and the conditions By controlling the operations of the corresponding units through the drive control unit 121, the irradiation control unit 123, and the like so that the operations according to the above are executed, the processing in various processing modes can be selectively performed. It is preferable that the processing mode can be selected according to a processing menu provided to the operator in the controller 110 by the operation of the processing unit 125, for example.

  Specifically, by changing the combination of the irradiation condition of the laser beam LB from the laser light source LS and the scanning condition of the laser beam LB with respect to the wafer W by moving the stage 101, the discrete scribe lines as described above can be obtained. Various processing such as formation or alignment mark formation can be performed under appropriate processing conditions.

<Modification>
FIG. 6 is a diagram for explaining a modification of the above-described embodiment. As shown in FIG. 6A, the scribe lines SL are usually provided in a lattice shape. Therefore, the wafer W is partitioned into a large number of rectangular regions (unit regions) RE1 by the scribe lines SL. Usually, the LED pattern PT is formed such that the unit region RE becomes a formation region (unit pattern region) of one LED element 10.

  However, the formation mode of the LED pattern PT is not limited to this. For example, as shown in FIG. 6A, even if the LED pattern PT is formed such that a region RE2 that extends over a plurality of unit regions becomes a formation region (unit pattern region) of one LED element 10. Good. This indicates that the wafers W having the same scribe line SL form can be used to form LED elements 10 having different sizes.

DESCRIPTION OF SYMBOLS 1 Sapphire substrate 2 Undoped layer 3 N-type layer 4 Light emitting layer 5 P-type layer 6 P-type electrode 7 N-type electrode 7a Electrode formation area 10 LED element 100 Laser processing apparatus 200 Break apparatus 201 Upper break bar 202 Lower break bar A Split Planned position CR, CR1, CR2 Crack F Focus position LB Pulse laser beam (Laser beam)
P Processing mark PT LED pattern SL Scribe line ST Street W Wafer W1 Substrate with LED pattern Wa, Wb (Wafer) main surface

Claims (5)

A method of manufacturing a substrate with an LED pattern,
A scribing step of forming a scribe line by performing laser scribing on the wafer along a predetermined division position determined in a lattice shape on one main surface of the wafer;
An LED pattern forming step of forming an LED pattern in which unit patterns each constituting one LED element are two-dimensionally repeated on the main surface of the wafer that has undergone the scribing step;
With
In the scribing step, the scribe line is formed as an array of a plurality of processing traces that are discretely present along the planned division position inside the wafer, and between the scribe line and the main surface. Extend the crack,
The manufacturing method of the board | substrate with an LED pattern characterized by the above-mentioned. It is a manufacturing method of the board | substrate with an LED pattern of Claim 1, Comprising:
In the scribing step, the pulse laser beam having a pulse width of 200 fsec to 100 psec is in a state where the in-focus position is the inside of the wafer of the wafer, and the irradiation region of each single pulse light of the pulse laser beam is By irradiating while scanning under the condition of being dispersed along the extending direction of the planned division position, the scribe line is formed,
The manufacturing method of the board | substrate with an LED pattern characterized by the above-mentioned. It is a manufacturing method of the board | substrate with an LED pattern of Claim 2, Comprising:
In the scribe process,
The beam diameter of the pulse laser beam at the in-focus position is set to 0.25 μm to 2.0 μm,
Forming the scribe line so that a maximum depth of the lowermost end of the processing mark from the main surface of the wafer is 15 μm to 50 μm;
The manufacturing method of the board | substrate with an LED pattern characterized by the above-mentioned. A method of manufacturing an LED element,
The board | substrate preparation process which produces the said board | substrate with an LED pattern by the manufacturing method of the board | substrate with an LED pattern in any one of Claim 1 thru | or 3.
An individualization step of obtaining a plurality of LED elements by dividing the substrate with the LED pattern obtained by the substrate manufacturing step into pieces by breaking along the scribe line;
The manufacturing method of the LED element characterized by the above-mentioned. An LED pattern formed by two-dimensionally repetitively forming unit patterns each constituting one LED element is provided on one main surface of the wafer, and is divided into a plurality of LEDs by being divided at the planned division positions. A substrate with an LED pattern on which an element is manufactured,
Inside the wafer, a scribe line that is an array of a plurality of processing marks is formed discretely along the planned division position, and a crack is extended between the scribe line and the main surface,
The board | substrate with an LED pattern characterized by the above-mentioned.

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