JP2019036662A - Manufacturing method for light-emitting element - Google Patents

Abstract

To provide a manufacturing method for a light-emitting element, by which an unsatisfactory rate of braking is reduced when a light-emitting element is separated from a semiconductor substrate by scribe braking, the semiconductor substrate having a window layer -cum- support substrate not lattice matching.SOLUTION: A manufacturing method for a light-emitting element comprises: forming a light-emitting layer part on a substrate by epitaxial-growing a first semiconductor layer, an active layer, and a second semiconductor layer by use of a lattice matching material; epitaxial-growing a window layer -cum- support substrate by use of a material not lattice matching with the light-emitting layer; removing the substrate; forming a first ohmic electrode; forming a removal part; forming a semiconductor substrate by forming a second ohmic electrode in the removal part; and separating a light-emitting element from the semiconductor substrate by scribe braking. In this method, a groove that is 70 μm or less in the remaining thickness of window layer -cum- support substrate is formed in a surface, opposite the light-emitting layer part formation surface, of the semiconductor substrate, and the light-emitting element is separated by scribe braking.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a light emitting element, and more particularly to a method for manufacturing a light emitting element including a step of separating a light emitting element from a semiconductor substrate by scribing and breaking.

  Products such as chip-on-board (COB) are excellent in heat dissipation from LED elements, and are LED chip mounting methods employed in applications such as lighting. When mounting an LED on a COB or the like, flip mounting in which a chip is directly bonded to a board is essential. In order to realize flip mounting, it is necessary to manufacture a flip chip in which energization pads having different polarities are provided on one surface of a light emitting element. Further, the surface opposite to the surface provided with the energization pad needs to be made of a material having a light extraction function.

  When a flip chip is manufactured using yellow to red LEDs, an AlGaInP-based material is used for the light emitting layer. Since the AlGaInP-based material has no bulk crystal and the LED portion is formed by an epitaxial method, a material different from that of AlGaInP is selected for the starting substrate. In many cases, GaAs or Ge is selected as the starting substrate, and these substrates have a property of absorbing light with respect to visible light. Therefore, when a flip chip is manufactured, the starting substrate is removed.

  However, since the epitaxial layer forming the light emitting layer is an extremely thin film, it cannot stand by itself after the starting substrate is removed. Therefore, it is necessary to replace the starting substrate with a material / structure having a function as a support substrate having a thickness sufficient to make the light emitting layer substantially transparent to the emission wavelength and function as a window layer and to be self-supporting. There is.

  GaP, GaAsP, sapphire, or the like is selected as a replacement material having a window layer / supporting substrate function. Whichever material is selected, since it is a different material from the AlGaInP-based material, mechanical properties such as lattice constant, thermal expansion coefficient and Young's modulus are different from those of the AlGaInP-based material.

  As such a technique, Patent Document 1 discloses a method of forming GaP by crystal growth as a window layer and supporting substrate.

  Here, an example of a method for manufacturing a conventional light emitting element having a flip chip structure will be described with reference to FIGS.

When manufacturing an AlGaInP-based epitaxial wafer, first, as shown in FIG. 3A, for example, a GaAs substrate inclined by 15 degrees in the [001] direction is prepared as a starting substrate 300. Next, (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6) is formed on the GaAs substrate 300 by metal organic chemical vapor deposition (MOVPE). A first semiconductor layer (N clad layer) 301 made of, an active layer 302 made of (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6), A second semiconductor layer (P clad layer) 303 made of (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6) is laminated, and the light emitting layer portion 307. Next, an intermediate composition layer 304 made of Ga _y In _1-y P (0.0 ≦ y ≦ 1.0) and a GaP window layer 305 having a thickness of 0.5 μm or more are sequentially stacked. These production methods are not limited to the MOVPE method, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Next, a window layer / support substrate 306 made of GaAs _z P _1-z (0.0 ≦ z ≦ 0.1) is formed in contact with the GaP window layer 305. Although the window layer / support substrate 306 can be formed by the MOVPE method or the MBE method, a hydride vapor phase epitaxy (HVPE) method that is inexpensive and has a high growth rate can be preferably used. The thickness can be about 100 μm, for example.

  Next, as shown in FIG. 3B, after the window layer / support substrate 306 is formed, a wafer 031 is formed by removing the GaAs substrate 300 of the AlGaInP-based epitaxial wafer by chemical etching. The chemical etchant preferably has an etching selectivity with respect to the AlGaInP-based material, and is generally removed with an ammonia-containing etchant.

  Next, as shown in FIG. 3C, after removing the GaAs substrate, a first ohmic electrode 351 is formed on the first semiconductor layer (lower cladding layer) 301 of the wafer 031, and at least the first semiconductor layer (lower cladding layer) is formed. ) After forming a region (removal part) 320 in which a part of 301 and the active layer 302 are cut out, a second ohmic electrode 361 is formed on a part of the removal part 320.

  Next, among the regions (non-removed portions) 310 other than the region (removed portion) 320 of the first semiconductor layer (lower cladding layer) 301, at least part of the region 311 that does not have the first ohmic electrode 351 is dielectric. A body portion 340 can be provided. In addition, the dielectric portion 341 can be provided in at least a part of the step portion 330 between the region 310 and the region 320. In the region 320, a semiconductor substrate A03 provided with a dielectric portion 342 in at least a part of the region 321 other than the second ohmic electrode 361 is obtained.

  FIG. 3C illustrates the case where all of the dielectric portions 340, 341, and 342 are provided. However, it is not necessary to include all of the dielectric portions 340, 341, and 342. can get. Further, although the structure having only the dielectric portion 340 is illustrated in the region 311, a light reflecting film or a light reflecting portion may be provided between the dielectric portion 340 and the region 311 of the first semiconductor layer 301. Alternatively, a light reflecting film or a light reflecting portion may be provided on the surface of the dielectric portion 340 that does not contact the region 311 of the first semiconductor layer 301.

  Further, although the case where the region 311 has a flat surface is illustrated, the region 311 may have a surface having unevenness. As for the surface having irregularities, a simple rough surface by wet etching, a faceted rough surface having a facet surface, a patterned rough surface patterned by photolithography having a pitch of several tens of μm to several hundreds of nm, and several to several hundreds of nanometers It can be a photonic rough surface having a pitch trench shape.

  Further, although the stepped portion 330, the region (removal portion) 320, and the window layer / support substrate 306 are illustrated as flat surfaces without unevenness, they may be uneven surfaces. As for the surface having irregularities, a simple rough surface by wet etching, a faceted rough surface having a facet surface, a patterned rough surface patterned by photolithography having a pitch of several tens of μm to several hundreds of nm, and several to several hundreds of nanometers Any of photonic rough surfaces having a trench shape with a pitch may be used. Further, although a structure in which there is no film on the surface of the window layer / supporting substrate 306 is shown, an antireflection film made of a dielectric may be provided.

  Next, as shown in FIG. 3D, a scribing process is performed on the second surface 03B of the semiconductor substrate A03 along the braking spare line 381 to make a scribe mark 382. The scribing process can be performed using, for example, a 4-point diamond head and a load of 50 g. The scribing conditions are not limited to the above-mentioned conditions. A multi-point or small-point head may be used, and the load is not limited to this value.

  The scribing may be performed by a laser ablation method without being limited to the diamond head. When the laser ablation method is employed, for example, a scribing process can be performed using a laser having a wavelength of 355 nm and an output of 0.5 W.

  After the scribing process, the protective sheet is placed on the surface of the second surface 03B, the blade is applied from the surface opposite to the protective sheet surface (first surface 03A), the braking process is performed, and the light emitting element is formed by dicing. A light emitting element is manufactured by separating.

JP2015-005551A

  By the way, in a semiconductor substrate in which the window layer / support substrate is formed of a lattice mismatched material such as GaP, when performing dicing by scribing / braking, high density crystal defects are originally formed on the window layer / support substrate such as GaP. Since there is (dislocation), it is difficult to extend the defect line with a physical force of the scribe level, and as a result, many braking failures dies occur.

  In order to reduce the occurrence frequency of braking failures, the frequency of occurrence can be reduced by increasing the pressure applied during braking, but the “cracking / destruction” process is not based on defective lines. It does not lead to improvement.

  The present invention has been made in view of the above problems, and reduces the braking failure rate when a light emitting element is separated from a semiconductor substrate having a window layer / supporting substrate such as a lattice mismatched GaP by scribe / braking. An object of the present invention is to provide a method for manufacturing a light emitting device.

In order to achieve the above object, according to the present invention, at least a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially grown by epitaxial growth on a substrate with a lattice-matching material with the substrate. Forming a window layer / support substrate epitaxially on the light emitting layer portion using a material having a lattice mismatch with the light emitting layer portion, removing the substrate, and Forming a first ohmic electrode on the surface of the first semiconductor layer; removing at least the first semiconductor layer and the active layer to form a removal portion; and the second semiconductor layer or window layer of the removal portion. By the step of forming a second ohmic electrode on the supporting substrate, at least the light emitting layer portion other than the removing portion, the first ohmic electrode, and the second ohmic electrode are formed on the window layer supporting substrate. A semiconductor substrate of manufacture, then, from the semiconductor substrate, in the manufacturing method of the light emitting element for producing a light emitting device by separating the light emitting element by scribing braking,
The light emitting element is separated by forming a groove with a remaining thickness of 70 μm or less in the window layer / supporting substrate on the surface of the semiconductor substrate opposite to the light emitting layer portion forming surface side, and then the semiconductor A light-emitting element is separated by making a scribe mark along the groove on the surface of the semiconductor substrate from the light-emitting layer portion forming surface side of the substrate and applying a force perpendicular to the semiconductor substrate to the entire length or a part of the groove. A method for manufacturing a light-emitting element is provided.

  With such a method of manufacturing a light emitting element, a groove having a remaining thickness of 70 μm or less in the window layer / supporting substrate is formed on the surface of the semiconductor substrate opposite to the light emitting layer portion forming surface. Even when the window layer / supporting substrate is epitaxially grown with a material mismatched with the light emitting layer, the defect rate in the scribe / braking process can be reduced.

  In this case, the groove is preferably formed by wet etching or dry etching.

  According to these methods, a groove having a desired depth can be reliably formed.

  With the method for manufacturing a light emitting device of the present invention, when separating the light emitting device from a semiconductor substrate having a window layer and supporting substrate such as a lattice mismatched GaP by scribe and braking, the braking failure rate is reduced. Thus, a high-quality light-emitting element can be manufactured with high productivity.

It is the schematic which showed 1st embodiment of the manufacturing method of the light emitting element of this invention. It is the schematic which showed 2nd embodiment of the manufacturing method of the light emitting element of this invention. It is the schematic which showed the manufacturing method of the conventional light emitting element. It is the graph which showed the relationship between the remaining thickness of the groove | channel in a window layer and support substrate, and the defect rate (%) by scribe braking about Examples 1-10 and Comparative Examples 1-6. It is the graph which showed the relationship between the residual thickness of the groove | channel in a window layer and support substrate, and the defect rate (%) by scribe braking about Examples 11-20 and Comparative Examples 7-16.

  As described above, in a semiconductor substrate in which the window layer / support substrate is formed of a lattice-mismatched material such as GaP, when dicing is performed by scribing / braking, the window layer / support substrate such as GaP originally has a high density. Therefore, there is a problem in that it is difficult to extend the defect line with a physical force of a scribe level, resulting in frequent occurrence of braking failure dies.

  Therefore, the present inventor has intensively studied to solve such problems. As a result, a groove having a remaining thickness of 70 μm or less in the window layer / supporting substrate is formed on the surface of the semiconductor substrate opposite to the light emitting layer portion forming surface side, and then diced by scribe braking. As a result, it was found that the defect rate due to dicing can be reduced, and the present invention has been completed.

That is, the present invention includes a step of sequentially forming at least a first semiconductor layer, an active layer, and a second semiconductor layer by epitaxial growth on a substrate using a lattice-matching material with the substrate to form a light emitting layer portion, and the light emission. A window layer / support substrate forming step of epitaxially growing a window layer / support substrate on the light emitting layer portion with a layer mismatched material and a layer mismatching material; a step of removing the substrate; and a first surface on the first semiconductor layer surface A step of forming an ohmic electrode; a step of removing at least the first semiconductor layer and the active layer to form a removed portion; and a second ohmic on the second semiconductor layer or window layer / support substrate of the removed portion. By forming an electrode, on the window layer and supporting substrate, at least a light emitting layer portion other than the removal portion, the first ohmic electrode, and the semiconductor substrate having the second ohmic electrode are manufactured, After, from the semiconductor substrate, in the manufacturing method of the light emitting element for producing a light emitting device by separating the light emitting element by scribing braking,
The light emitting element is separated by forming a groove with a remaining thickness of 70 μm or less in the window layer / supporting substrate on the surface of the semiconductor substrate opposite to the light emitting layer portion forming surface side, and then the semiconductor A light-emitting element is separated by making a scribe mark along the groove on the surface of the semiconductor substrate from the light-emitting layer portion forming surface side of the substrate and applying a force perpendicular to the semiconductor substrate to the entire length or a part of the groove. A method of manufacturing a light-emitting element.

  Hereinafter, the first embodiment and the second embodiment of the present invention will be described in more detail with reference to the drawings, but the present invention is not limited thereto. Note that the first embodiment and the second embodiment differ only in the groove formation method, and the other steps can be basically performed by the same method. First, common steps in the first half of the first embodiment and the second embodiment will be described with reference to FIGS. 1 (a) to 1 (c) and FIGS. 2 (a) to 2 (c).

  First, as shown in FIGS. 1A and 2A, when an AlGaInP-based epitaxial wafer is manufactured, starting substrates 100 and 200 such as GaAs inclined by 15 degrees in the [001] direction are prepared.

  Next, at least the first semiconductor layers 101 and 201, the active layers 102 and 202, and the second semiconductor layers 103 and 203 are sequentially grown by epitaxial growth on the substrates 100 and 200 using a material that is lattice-matched with the substrates 100 and 200. The light emitting layer portions 107 and 207 are formed.

Specifically, when a GaAs substrate is used as the substrates 100 and 200, (Al _x Ga _1-x ) _y In _1-y P () is formed on the GaAs substrate by metal organic vapor phase epitaxy (MOVPE). N clad layers (first semiconductor layers) 101, 201 composed of 0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6), (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6), (Al _x Ga _1−x ) _y In _1−y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6) P-cladding layers (second semiconductor layers) 103 and 203 made of) are sequentially grown by epitaxial growth to form light emitting layer portions 107 and 207. Next, intermediate composition layers 104 and 204 made of Ga _y In _1-y P (0.0 ≦ y ≦ 1.0) and window layers 105 and 205 made of GaP having a thickness of 0.5 μm or more are sequentially stacked. be able to.

  These production methods are not limited to the MOVPE method, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Next, the window layer / supporting substrates 106 and 206 are epitaxially grown on the light emitting layer portion using a material having a lattice mismatch with the light emitting layer portions 107 and 207. Specifically, the light emitting layer portions 107 and 207 are in contact with the GaP window layers 105 and 205, and the lattice mismatching system GaAs _z P _1-z (0.0 ≦ z ≦ 0.1) window layer and supporting substrate. The window layer / support substrates 106 and 206 can be formed on the light emitting layer portions 107 and 207 by epitaxially growing the layers 106 and 206. Although the window layer / supporting substrates 106 and 206 can be formed by the MOVPE method or the MBE method, a hydride vapor phase epitaxy (HVPE) method which is inexpensive and has a high growth rate can be preferably used. The thickness can be 20 to 200 μm, for example, about 100 μm.

  After the window layer / supporting substrates 106 and 206 are formed, a step of removing the substrates 100 and 200 is performed as shown in FIGS. 1 (b) and 2 (b). For example, the GaAs substrates 100 and 200 of the AlGaInP-based epitaxial wafer are removed by chemical etching to form wafers 011 and 021. The chemical etchant preferably has an etching selectivity with respect to the AlGaInP-based material, and is generally removed with an ammonia-containing etchant.

  Next, as shown in FIGS. 1C and 2C, after removing the substrates 100 and 200, the first ohmic electrode is formed on the lower clad layers (first semiconductor layers) 101 and 201 of the wafers 011 and 021. 151, 251 is formed, and then at least the first semiconductor layers 101, 201 and the active layers 102, 202 are removed to form removed portions 120, 220, and the second semiconductor layers 103, 203 of the removed portions 120, 220 or Second ohmic electrodes 161 and 261 are formed on the window / support substrates 106 and 206.

  Next, among the non-removed portions (regions other than the removed portions 120 and 220) 110 and 210, the dielectric portions 140 and 240 are provided in at least a part of the regions 111 and 211 that do not have the first ohmic electrodes 151 and 251. be able to.

  In addition, the dielectric portions 141 and 241 can be provided on at least part of the step portions 130 and 230 between the non-removal portions 110 and 210 and the removal portions 120 and 220.

  Dielectric portions 142 and 242 may be provided in at least a part of the regions 121 and 221 other than the second ohmic electrodes 161 and 261 in the removal portions 120 and 220. The semiconductor substrates A01 and A02 manufactured as described above are formed on the window layer / support substrates 106 and 206, at least the light emitting layer portions 107 and 207 other than the removal portions 120 and 220, and the first ohmic electrode 151, 251 and second ohmic electrodes 161 and 261.

  In the present embodiment, the case where all of the dielectric portions 140, 240, 141, 241, 142, and 242 are illustrated is illustrated, but it is not necessary to have all, and even if only a portion is included, the same The effect is obtained. Further, in the present embodiment, the structure including only the dielectric portions 140 and 240 in the regions 111 and 211 of the first semiconductor layers 101 and 201 is illustrated, but the dielectric portions 140 and 240 and the first semiconductor layer are illustrated. A light reflecting film or a light reflecting portion may be provided between the regions 111 and 211 of the 101 and 201, or the surfaces of the dielectric portions 140 and 240 that do not contact the regions 111 and 211 of the first semiconductor layers 101 and 201. A light reflecting film or a light reflecting portion may be provided on the side.

  Moreover, in this embodiment, although the area | regions 111 and 211 have illustrated the case where it has a flat surface, you may have the surface which has an unevenness | corrugation. As for the surface having irregularities, a simple rough surface by wet etching, a faceted rough surface having a facet surface, a patterned rough surface patterned by photolithography having a pitch of several tens of μm to several hundreds of nm, and several to several hundreds of nanometers It can be a photonic rough surface having a pitch trench shape.

  Further, in the present embodiment, the stepped portions 130 and 230, the removing portions 120 and 220, and the window layer / supporting substrates 106 and 206 are illustrated as flat surfaces without unevenness, but even with uneven surfaces. Good. As for the surface having irregularities, a simple rough surface by wet etching, a faceted rough surface having a facet surface, a patterned rough surface patterned by photolithography having a pitch of several tens of μm to several hundreds of nm, and several to several hundreds of nanometers The case of any photonic rough surface having a trench shape with a pitch is included.

  In addition, although a structure in which there is no film on the surface of the window / supporting substrates 106 and 206 is shown, an antireflection film made of a dielectric may be provided.

  Up to this point, the first embodiment and the second embodiment are exactly the same steps. Thereafter, as shown in FIGS. 1D, 1E, 2D, and 2E, the surface of the semiconductor substrate A01, A02 opposite to the light emitting layer portion forming surface (that is, the window layer) Grooves 180 and 280 having a remaining thickness of 70 μm or less in the window layer / support substrates 106 and 206 are formed in the first surface 01A and 02A having the support substrates 106 and 206, and the light emitting layers of the semiconductor substrates A01 and A02 From the part forming surface (01B, 02B) side, scribe marks 182 and 282 are formed along the groove on the surface of the semiconductor substrate, and a force perpendicular to the semiconductor substrate is applied to the entire length or part of the grooves 180 and 280 The process of isolate | separating is performed. The method for forming the groove will be described in detail below by dividing it into wet etching (first embodiment) and dry etching (second embodiment).

First, a first embodiment will be described using FIGS. 1D and 1E. As shown in FIG. 1D, an SiO ₂ film is formed on the surface 01A of the semiconductor substrate A01 opposite to the light emitting layer portion forming surface side (that is, the first surface having the window layer / supporting substrate 106). A SiO ₂ pattern 170 having a thickness of 1 μm and opening a preliminarily provided braking spare line 181 is provided by photolithography. Etching is easy if the width of the opening 171 is large, but it can be, for example, 25 μm. The width of the opening 171 is not limited to 25 μm, and may have a width of 1/20 or more with respect to the etching depth.

Next, electron wax is applied to the surface (second surface) 01B on the light emitting layer portion forming surface side opposite to the first surface 01A of the semiconductor substrate A01 having the SiO ₂ pattern 170, and hydrochloric acid and nitric acid are 1: Into the etching solution mixed at a ratio of 3, the opening 171 is etched. It is possible to perform etching of about 1 μm by immersion for about 5 minutes. Then, control is performed by time management so as to obtain a desired groove depth while keeping the etching solution warm. At this time, the groove 180 is formed so that the remaining thickness of the window layer / supporting substrate 106 is 70 μm or less.

  Next, as shown in FIG. 1E, on the second surface 01B surface of the semiconductor substrate A01 provided with a desired groove depth, along the groove 180 (that is, along the braking spare line 181), A scribing process for attaching the scribing mark 182 is performed. The scribing process can be performed using, for example, a 4-point diamond head and a load of 50 g. The scribing conditions are not limited to the above-mentioned conditions. A multi-point or small-point head may be used, and the load is not limited to this value.

  The scribing may be performed by a laser ablation method without being limited to the diamond head. When the laser ablation method is employed, for example, a scribing process can be performed using a laser having a wavelength of 355 nm and an output of 0.5 W.

  After the scribing process, the light emitting element is separated by applying a force perpendicular to the semiconductor substrate A01 to the entire length or a part of the groove 180. At this time, a protective sheet is placed on the surface of the second surface 01B, and a cutting process is performed by applying a blade from a surface opposite to the surface of the protective sheet.

Next, a second embodiment will be described with reference to FIGS. On the surface opposite to the light emitting layer portion forming surface side of the semiconductor substrate A02 (that is, the first surface having the window layer / supporting substrate 206 of the semiconductor substrate A02) 02A, a 1 μm SiO ₂ film is formed and attached in advance. A photoresist pattern 290 having an opening in the area of the braking spare line 281 is provided by photolithography. Etching is easy if the width of the opening 271 is large, but can be, for example, 25 μm. The width of the opening portion 271 is not limited to 25 μm, and may have a width of 1/20 or more with respect to the etching depth.

The wafer A02 having the photoresist pattern 290 is put into a hydrofluoric acid solution to obtain a SiO ₂ pattern 270 substantially the same as the photoresist pattern 290. After forming the SiO ₂ pattern 270, the photoresist pattern 290 is removed by organic cleaning and ashing.

For example, a treatment containing chlorine plasma is performed on the first surface 02A of the wafer A02 having the SiO ₂ pattern 270, and the opening 271 is etched. Cl ₂ can be used as a chlorine plasma source, and ICP can be used as a plasma application method. The plasma application output can be set to 150 W, for example. Control is performed by time management so that a desired groove depth is obtained. At this time, the groove 280 is formed so that the remaining thickness of the window layer / supporting substrate 206 is 70 μm or less.

The conditions shown above are merely examples and are not limited to the above conditions. In addition, SiCl ₄ and BCl ₃ can be selected as the chlorine plasma generation source and gas, and RIE can also be selected as the plasma application method. If the output is 50 W or more, etching can be performed.

  On the second surface 02B surface opposite to the first surface 02A of the semiconductor substrate A02 provided with a desired groove depth, along the groove 280 (that is, along the braking reserve line 281), the scribe mark 282 is formed. Perform a scribing process. The scribing process can be performed with a load of 50 g using a 4-point diamond head. The scribing conditions are not limited to the above-mentioned conditions. A multi-point or small-point head may be used, and the load is not limited to this value.

  Moreover, it is not limited to a diamond head, You may perform a scribe process by the laser ablation method. When the laser ablation method is employed, for example, a scribing process can be performed using a laser having a wavelength of 355 nm and an output of 0.5 W.

  After the scribing process, the light emitting element is separated by applying a force perpendicular to the semiconductor substrate A02 to the entire length or a part of the groove 280. At this time, the protective sheet is placed on the surface of the second surface 02B, and the cutting process is performed by applying a blade from the surface opposite to the protective sheet surface, whereby dicing can be performed.

  As described above, grooves 180 and 280 having a remaining thickness of 70 μm or less in the window layer / supporting substrates 106 and 206 are formed on the surfaces 01A and 02A opposite to the light emitting layer portion forming surface side of the semiconductor substrates A01 and A02. The scribe marks 182 and 282 are formed along the grooves on the surfaces of the semiconductor substrates A01 and A02 from the light emitting layer portion forming surface side of the semiconductor substrate, and a force perpendicular to the semiconductor substrate is applied to the entire length or part of the grooves 180 and 280. In addition to separating the light emitting element by adding to the semiconductor substrate having the window layer / supporting substrate such as a lattice mismatched GaP or the like, it is possible to reduce the braking failure rate when separating the light emitting element by scribe braking. it can.

  When the groove having a remaining thickness of the window layer / supporting substrate exceeding 70 μm is formed, when the groove is not formed, or when the groove is formed on the light emitting layer portion forming surface side of the semiconductor substrate, the braking failure rate is Get higher.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples of the present invention, but the present invention is not limited to these.

(Examples 1-5)
The light emitting device was manufactured based on the first embodiment of the method for manufacturing the light emitting device of the present invention as shown in FIG.
First, as shown in FIG. 1, a substrate made of GaAs (001) was prepared as a starting substrate 100, and a double hetero layer (light emitting layer portion 107) as a functional layer was formed on the substrate by MOVPE. The light emitting layer portion 107 is formed by sequentially laminating a lower clad layer (first semiconductor layer) 101, an active layer 102, and an upper clad layer (second semiconductor layer) 103.

In the first semiconductor layer 101, a composition of (Al _x Ga _1-x ) _y In _1-y P (0.6 ≦ x ≦ 1.0, 0.4 ≦ y ≦ 0.6) is selected. In the example, as the first semiconductor layer, an n-type AlInP cladding layer is 0.7 μm (doping concentration 3.0 × 10 ¹⁷ / cm ³ ), and an n-type Al _0.85 GaInP layer is 0.3 μm (doping concentration 1.0). X10 ¹⁷ / cm ³ ).

The active layer 102 is selected from (Al _x Ga _1-x ) _y In _1-y P (0.15 ≦ x ≦ 0.8, 0.4 ≦ y ≦ 0.6), and the composition x and y depends on the wavelength. Changed. In this embodiment, a multiple active layer is used as the active layer. The film thicknesses of the active layer and the barrier layer were changed depending on the desired wavelength, and were adjusted according to the wavelength in the range of 4 to 12 nm.

As the second semiconductor layer 103, a p-type AlInP clad layer is 0.9 μm (doping concentration 3.0 × 10 ¹⁷ / cm ³ ), and a p-type Al _0.6 GaInP layer is 0.1 μm (doping concentration 1.0 × 10). ¹⁷ / cm ³ ).

  A buffer layer (intermediate composition layer 104) made of GaInP is formed on the light emitting layer 107, and a window layer / support substrate 106 made of GaP is formed on the buffer layer by about 100 μm by MOVPE and HVPE. did.

  After forming the window layer / supporting substrate 106, as shown in FIG. 1B, the substrate 100 was removed by wet etching to form a self-supporting substrate, and the first ohmic electrode 151 was formed on the surface from which the substrate 100 was removed. . The first ohmic electrode 151 is made of an Au electrode containing Si, Zn, and S, and has a thickness of 1.5 μm.

  Next, as shown in FIG. 1C, a part of the light emitting layer portion 107 is cut out by a photolithography method and an etching method to expose the light emitting layer region 110 (non-removed portion) and the window layer / support substrate. Area (removal part) 120 is provided.

  Then, the second ohmic electrode 161 was formed on the window layer / supporting substrate 106 of the removal portion 120. The second ohmic electrode 161 was made of an Au electrode containing Be, and the film thickness was 1.5 μm.

Next, as shown in FIG. 1D, a 1 μm SiO ₂ film is formed on the first surface (01A) of the semiconductor substrate A01 having the window layer / supporting substrate 106, and the region of the braking spare line 181 is formed. The opened SiO ₂ pattern 170 was provided by photolithography. The opening width was 25 μm.

Next, electron wax was applied to the second surface (01B) opposite to the first surface (01A) of the semiconductor substrate having the SiO ₂ pattern 170, and hydrochloric acid and nitric acid were mixed at a ratio of 1: 3. The groove 180 was formed by etching into the etching solution and etching the opening 171. As shown in Table 1, the remaining thickness (groove portion thickness) of the groove 180 in the window layer / supporting substrate 106 was changed by changing the etching time. At this time, the groove 180 was formed so that the remaining thickness in the window layer / supporting substrate 106 was 70 μm or less.

  Next, as shown in FIG. 1E, a scribing process was performed along the preliminary braking line 181 on the second surface (01B) of the semiconductor substrate provided with a desired groove depth. The scribing process was performed using a 4-point diamond head with a load of 50 g.

  After the scribing treatment, a protective sheet was placed on the surface of the second surface 01B, and a braking treatment was performed by applying a blade from the surface opposite to the protective sheet surface to form a die.

(Comparative Examples 1-3)
A light emitting device was manufactured in the same manner as in Example 1 except that the etching time was changed and the remaining thickness of the groove window layer / support substrate was changed to the thickness shown in Table 1.

(Examples 6 to 10)
The light emitting device was fabricated in the same manner as in Example 1, except that the opening was etched by performing treatment containing chlorine plasma, and the remaining thickness of the groove window layer / supporting substrate was set to the thickness shown in Table 1. Manufactured. Cl ₂ was used as the chlorine plasma source, and ICP was used as the plasma application method. The plasma application output was 150 W. Control was performed by time management so as to obtain a desired groove depth. At this time, the grooves were formed so that the remaining thickness of the window layer / supporting substrate was 70 μm or less.

(Comparative Examples 4-6)
A light emitting device was manufactured in the same manner as in Example 6 except that the remaining thickness of the groove window layer and supporting substrate was changed to the thickness shown in Table 1.

(Examples 11 to 15)
A light emitting device was manufactured in the same manner as in Example 1 except that the thickness of the window layer / support substrate was about 120 μm and the remaining thickness of the groove window layer / support substrate was changed to the thickness shown in Table 1.

(Comparative Examples 7 to 11)
A light emitting device was manufactured in the same manner as in Example 11 except that the remaining thickness of the groove window layer and supporting substrate was changed to the thickness shown in Table 1.

(Examples 16 to 20)
A light emitting device was manufactured in the same manner as in Example 6 except that the thickness of the window layer / support substrate was about 120 μm and the remaining thickness of the groove window layer / support substrate was changed to the thickness shown in Table 1.

(Comparative Examples 12 to 16)
A light emitting device was manufactured in the same manner as in Example 16 except that the remaining thickness of the groove window layer / support substrate was changed to the thickness shown in Table 1.

  Tables 1 and 4 show the relationship between the remaining thickness of the groove window layer / support substrate and the defect rate (%) due to scribe braking for Examples 1 to 10 and Comparative Examples 1 to 6. Tables 1 and 5 show the relationship between the remaining thickness of the groove window layer / support substrate and the defect rate (%) due to scribe braking for Examples 11 to 20 and Comparative Examples 7 to 16.

  From Table 1, FIG. 4 and FIG. 5, it was found that the braking failure rate could be reduced in the example in which the groove having the remaining thickness of 70 μm or less was formed.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

100, 200, 300 ... substrate, 101, 201, 301 ... first semiconductor layer, 102, 202, 302 ... active layer, 103, 203, 303 ... second semiconductor layer, 104, 204, 304 ... intermediate composition layer, 105 , 205, 305 ... window layer, 106, 206, 306 ... window layer and supporting substrate, 107, 207, 307 ... light emitting layer part, 110, 210, 310 ... non-removal part 111, 211, 311 ... non-removal part , A region not having the first ohmic electrode, 120, 220, 320... Removed portion, 121, 221, 321... Removed portion, a region other than the second ohmic electrode, 130, 230, 330. , 142, 240, 241, 242, 340, 341, 342... Dielectric part, 151, 251, 351, first ohmic electrode, 161, 261 361 ... second ohmic electrode, 170, 270 ... SiO ₂ pattern, 290 ... photoresist pattern, 171 and 271 ... opening, 180, 280 ... groove, 181,281,381 ... braking spare line, 182,282 , 382 ... Scribe marks, 011,021, 031 ... Wafer, A01, A02, A03 ... Semiconductor substrate, 01A, 02A, 03A ... Surface opposite to the light emitting layer forming surface side of the semiconductor substrate (first Surface), 01B, 02B, 03B... Surface (second surface) on the light emitting layer portion forming surface side of the semiconductor substrate.

Claims (2)

Forming a light emitting layer portion on a substrate by sequentially growing at least a first semiconductor layer, an active layer, and a second semiconductor layer by epitaxial growth with a material of lattice matching system with the substrate;
A window layer / support substrate forming step of epitaxially growing a window layer / support substrate on the light emitting layer portion with a material of lattice mismatching with the light emitting layer portion;
Removing the substrate;
Forming a first ohmic electrode on the surface of the first semiconductor layer;
Removing at least the first semiconductor layer and the active layer to form a removal portion;
By forming a second ohmic electrode on the second semiconductor layer or window layer / support substrate of the removal portion,
On the window / support substrate, a semiconductor substrate having at least a light emitting layer portion other than the removal portion, the first ohmic electrode, and the second ohmic electrode is manufactured. In a method for manufacturing a light emitting element, in which the light emitting element is manufactured by separating the light emitting element by braking,
The light emitting element is separated by forming a groove with a remaining thickness of 70 μm or less in the window layer / supporting substrate on the surface of the semiconductor substrate opposite to the light emitting layer portion forming surface side, and then the semiconductor A light-emitting element is separated by making a scribe mark along the groove on the surface of the semiconductor substrate from the light-emitting layer portion forming surface side of the substrate and applying a force perpendicular to the semiconductor substrate to the entire length or a part of the groove. A method for manufacturing a light-emitting element.   The method for manufacturing a light-emitting element according to claim 1, wherein the groove is formed by wet etching or dry etching.

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