JP5346909B2 - Semiconductor light emitting device, lighting module, lighting device, and display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device which allows the increase in yield of finished products without inducing the increase in size. <P>SOLUTION: LEDs D1 to D9 being light-emitting elements constituted of a semiconductor multilayer films 206 are disposed midway on a principal surface of a base substrate 204, and a second electrode 226 of one LED and a first electrode 216 of another LED are successively electrically connected in series by bridging wires 234A and 234B being film wires crawlingly laid on an insulating film 228 formed on side surfaces of LEDs, and the first electrode 216 of the LED D6 at one end of an LED array being an array of light-emitting elements connected in series and a first feed terminal 232 are electrically connected, and the second electrode 226 of the LED D4 at the other end and a second feed terminal 230 are electrically connected via a film wire 236A crawlingly laid on the insulating film 228, and a phosphor film 208 covers LEDs D1 to D9 so as to be received by the base substrate 204. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a semiconductor light emitting device such as a light emitting diode (hereinafter referred to as “LED”), a lighting module, a lighting device, and a display element using the semiconductor light emitting device, and more particularly to a phosphor. The present invention relates to a semiconductor light emitting device that obtains light of a desired color.

  LEDs have higher efficiency and longer life than incandescent bulbs and halogen bulbs, and in particular, as white LEDs have become increasingly brighter in recent years, research on the use of white LEDs for lighting applications has been actively conducted. Currently, the mainstream of white LEDs is a combination of an LED bare chip that emits blue light and a phosphor that emits yellow light when excited by the blue light, and obtains white light by mixing blue light and yellow light.

  Such a white LED is generally manufactured through a wafer process for obtaining an LED bare chip and an assembly process for packaging the LED bare chip into a white LED.

  In LED bare chips manufactured through a wafer process, a semiconductor multilayer film including a light emitting layer is formed by crystal growth on a translucent substrate such as a sapphire substrate, and the semiconductor multilayer film faces the sapphire substrate. A structure having both positive (anode) and negative (cathode) electrodes on the opposite side is common.

  Since the LED bare chip cannot be used as it is, it is mounted on a lead frame, a printed wiring board or the like in the assembly process. A resin mixed with a fluorescent material is dropped from the mounted LED bare chip and hardened to form a phosphor film. Furthermore, the white LED is completed through a process such as molding the periphery of the phosphor film with a resin. The completed white LED is shipped after inspection of electrical and optical characteristics.

  However, the white LED manufactured as described above has a problem that a defect rate concerning optical characteristics is increased. That is, in the white LED, since the phosphor film is formed by a method of dropping and solidifying a resin mixed with a phosphor material on the LED bare chip, the thickness of the phosphor film is likely to vary. In the white LED, the color temperature is determined by the light quantity balance of the blue light and the yellow light. When the phosphor film is thick, the blue light is reduced, the yellow light is increased and the color temperature is reduced to white light. Conversely, if the phosphor film is thin, the color temperature becomes white light with a high color temperature, and a desired color temperature cannot be obtained. In addition, if the thickness of the phosphor film exceeds the allowable limit and becomes non-uniform, a problem of uneven color occurs.

The white LED in which such a defect has occurred is rejected in the inspection of the optical characteristics described above, resulting in a decrease in the yield of the finished product (white LED).
Under the circumstances as described above, there has been a demand to inspect color unevenness before the assembly process in order to improve the yield of finished products. An LED chip described in Patent Document 1 is known as one developed to meet this demand.

  In the LED chip described in Patent Document 1, the LED bare chip is placed on a substrate (submount substrate) having a slightly larger main area than the LED bare chip, and the semiconductor multilayer film is directed downward (that is, the sapphire substrate is directed upward). And a phosphor film is formed around the LED bare chip as a receiving tray. According to this, color unevenness and the like can be inspected before being mounted on a lead frame or a printed wiring board in the assembly process, so that the yield of the finished product is improved.

JP 2001-15817 A (Patent No. 3399440)

  However, since the LED chip described in Patent Document 1 includes an additional component such as a submount substrate, the thickness (height) of the entire chip increases by the size of the submount substrate, leading to an increase in size of the chip. End up.

  In view of the above problems, the present invention provides a semiconductor light emitting device capable of improving the yield of a finished product without causing an increase in size, an illumination module using the semiconductor light emitting device, an illumination device, and a display element. The purpose is to do.

In order to achieve the above object, a semiconductor light emitting device according to the present invention is arranged in the middle of a base substrate and one main surface of the base substrate, each of which is a first conductive type layer and a light emitting element from the base substrate side. A plurality of light emitting elements composed of a semiconductor multilayer film in which a layer and a second conductivity type layer are laminated in this order, and a main surface of each of the light emitting elements opposite to the light emitting layer of the first conductivity type layer A first electrode formed; a second electrode formed on a main surface opposite to the light emitting layer of the second conductivity type layer in each light emitting element; and an insulation formed on a side surface of each light emitting element. Each of the semiconductor multilayer films having the film and the first power supply terminal and the second power supply terminal formed on the one main surface of the base substrate so as to be separated from each other, and constituting each of the light emitting elements, Formed by crystal growth on a single crystal substrate different from Is a film separated from the single crystal substrate and transferred to the base substrate, wherein a second electrode of one light-emitting element and a first electrode of another light-emitting element are provided on the insulating film. The wiring is sequentially electrically connected, and all or a part of the plurality of light emitting elements are connected in series, and the first electrode of the light emitting element at one end of the light emitting element array connected in series and the first A power supply terminal is electrically connected, and the second electrode of the other end of the light emitting element and the second power supply terminal are electrically connected via a film wiring provided on the insulating film. And the phosphor film is formed so as to cover the side surface of each light emitting element and the main surface opposite to the base substrate in such a manner that the phosphor film is received by the base substrate . Each has a fan shape in plan view, and the plurality of semiconductor multilayer films are in plan view. Characterized in that it is arranged to look like a circle.

  The second electrode is formed at an edge of the main surface of the second conductivity type layer, and electrically connects the second electrode of one light emitting element and the first electrode of another light emitting element. The film wiring is drawn from the second electrode to the side of the second conductivity type layer, and electrically connects the second electrode of the light emitting element at the other end and the second power supply terminal. The wiring is characterized in that it is led out from the second electrode to the side of the second conductivity type layer.

The phosphor film is characterized in that a thickness of a portion of each semiconductor multilayer film covering a main surface opposite to the base substrate is substantially equal to a thickness of a portion covering a side surface of the fan-shaped arc portion. .

In addition, a concavo-convex structure for improving light extraction efficiency is formed on a main surface of the second conductivity type layer opposite to the light emitting layer.
In order to achieve the above object, an illumination module according to the present invention includes a mounting board, and the semiconductor light emitting device is mounted on the mounting board.

In order to achieve the above object, an illumination device according to the present invention includes the illumination module as a light source.
In order to achieve the above object, a display device according to the present invention includes the above-described semiconductor light emitting device as a light source.

  According to the semiconductor light emitting device according to the present invention, in the middle of one main surface of the base substrate, a plurality of light emitting elements composed of a semiconductor multilayer film are arranged and received by the base substrate, Since the phosphor film is formed so as to cover the side surface of each light emitting element and the main surface opposite to the base substrate, in this state, it is possible to inspect optical characteristics such as color unevenness. . That is, it is possible to inspect before mounting on a lead frame or a printed wiring board, and the yield of finished products can be improved. Moreover, there is no increase in size due to additional parts such as a submount substrate as in the prior art.

  In addition, according to the illumination module and the illumination device according to the present invention, since the semiconductor light emitting device described above is included, the yield of the illumination module and the illumination device according to the finished product can be improved, thereby reducing the cost. it can.

1 is a diagram showing an LED chip according to Embodiment 1. FIG. (A) is a top view of the state except a fluorescent substance layer, (b) is the AA sectional view taken on the line in (a), (c) is a bottom view. 5 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 1. FIG. 5 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 1. FIG. 5 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 1. FIG. 5 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 1. FIG. 5 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 1. FIG. 5 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 1. FIG. 6 is a diagram showing an LED chip according to Embodiment 2. FIG. (A) is a top view of the state except a fluorescent substance layer, (b) is the BB line sectional drawing in (a). 10 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 2. FIG. 10 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 2. FIG. 10 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 2. FIG. 10 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 2. FIG. 10 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 2. FIG. 10 is a diagram showing a part of the manufacturing process of the LED chip according to Embodiment 2. FIG. FIG. 6 is a diagram showing an LED array chip according to a third embodiment. (A) is a top view of the state which removed the fluorescent substance layer, (b) is CC sectional view taken on the line in (a), (c) is a connection diagram in an LED array chip. 12 is a diagram showing a part of the manufacturing process of the LED array chip according to Embodiment 3. FIG. 12 is a diagram showing a part of the manufacturing process of the LED array chip according to Embodiment 3. FIG. 12 is a diagram showing a part of the manufacturing process of the LED array chip according to Embodiment 3. FIG. 12 is a diagram showing a part of the manufacturing process of the LED array chip according to Embodiment 3. FIG. FIG. 6 is a diagram showing an LED array chip according to a fourth embodiment. (A) is a perspective view, (b) is a plan view, and (c) is a connection diagram in the LED array chip. (A) is the HH sectional view taken on the line in FIG.20 (b), (b) is the J * J sectional view. FIG. 10 is a diagram showing a part of a manufacturing process of an LED array chip according to a fourth embodiment. FIG. 10 is a diagram showing a part of a manufacturing process of an LED array chip according to a fourth embodiment. FIG. 10 is a diagram showing a part of a manufacturing process of an LED array chip according to a fourth embodiment. FIG. 10 is a diagram showing a part of a manufacturing process of an LED array chip according to a fourth embodiment. FIG. 10 is a diagram showing a part of a manufacturing process of an LED array chip according to a fourth embodiment. FIG. 10 is a diagram showing a part of a manufacturing process of an LED array chip according to a fourth embodiment. FIG. 10 is a perspective view of a white LED module according to Embodiment 5. (A) is a top view of the said white LED module, (b) is the GG line sectional drawing in (a), (c) is an enlarged view of the chip mounting part in (b). (A) is a figure which shows the wiring pattern in the said white LED module, (b) is a figure which shows the pad pattern formed on the ceramic substrate which comprises a white LED module. (A) is a perspective view which shows the illuminating device in Embodiment 5, (b) is a bottom view of the said illuminating device. FIG. 10 is an exploded perspective view of a lighting device in a fifth embodiment. FIG. 10 shows an emission spectrum of the lighting device in the fifth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1A is a plan view of a white LED chip 2 (hereinafter simply referred to as “LED chip 2”) as a semiconductor light emitting device, and FIG. FIG. 1C is a sectional view of the LED chip 2, and FIG. 1A shows a state excluding a phosphor film 8 (see FIG. 1B) described later. Moreover, the scale between each component is not unified in all the figures including FIG.

  As shown in FIG. 1, the LED chip 2 has a configuration in which a semiconductor multilayer film 6 and a phosphor film 8 are provided on a high-resistance Si substrate 4 (hereinafter simply referred to as “Si substrate 4”) serving as a base substrate. I am doing. The Si substrate 4 has a main surface that is slightly larger in area than the main surface of the semiconductor multilayer film 6, and the semiconductor multilayer film 6 is arranged in the middle of one main surface of the Si substrate 4.

  The semiconductor multilayer film 6 includes, in order from the Si substrate 4 side, a p-AlGaN layer 10 (thickness 200 nm) that is a conductive type layer, an InGaN / AlGaN multiple quantum well light emitting layer 12 (thickness 40 nm), and an n type that is a conductive type layer. -It consists of the AlGaN layer 14 (thickness 2 micrometers), and comprises the diode structure.

  The chip size is 500 μm square and the thickness is 300 μm (Si substrate 4 thickness 100 μm, phosphor film 8 thickness 200 μm (height from the upper surface of Si substrate 4)). The thickness of the semiconductor multilayer film 6 is as described above, and the size of the main surface is 420 μm square.

  A high reflectivity electrode 16 made of Rh / Pt / Au is formed on the entire bottom surface of the p-AlGaN layer 10 (the main surface opposite to the light emitting layer 12). As will be described later, the semiconductor multilayer film 6 and the high reflectivity electrode 16 are separately formed on a sapphire substrate 42 (see FIG. 2) by a semiconductor process and then transferred to the Si substrate 4.

  A conductive film 18, which is a conductive member, is formed at least in a region corresponding to the high reflectivity electrode 16 on the upper surface of the Si substrate 4. The conductive film 18 is made of Ti / Pt / Au, and is bonded to the high reflectivity electrode 16 via a bonding layer 20 made of a conductive material such as Au / Sn.

An uneven structure 22 is formed on the upper surface of the n-AlGaN layer 14 (main surface opposite to the light emitting layer 12), which serves as a light extraction surface in the semiconductor multilayer film 6, in order to improve light extraction efficiency. As will be described later, the concavo-convex structure 22 is formed by selectively removing a part of the tantalum oxide (Ta ₂ O ₅ ) film 24 formed on the upper surface of the n-AlGaN layer 14 with a uniform thickness by etching. It is a thing. In addition, an L-shaped electrode 26 made of Ti / Pt / Au is formed in a partial region on the upper surface of the n-AlGaN layer 14.

An insulating film 28 made of silicon nitride is formed on the entire side surface and a part of the upper surface of the semiconductor multilayer film 6 (a shape that borders the upper surface along the outer periphery).
An anode feeding terminal 30 and a cathode feeding terminal 32 made of Ti / Au are formed on the lower surface of the Si substrate 4 (the surface opposite to the side on which the semiconductor multilayer film 6 is formed).

  The conductive film 18 has an extending portion 18 </ b> A that protrudes from the lower surface of the semiconductor multilayer film 6. The conductive film 18 is electrically connected to the anode power supply terminal 30 through a through hole 34 formed in the Si substrate 4 in the extended portion 18A.

  On the other hand, one end portion of the wiring 36 extending to the Si substrate 4 is connected to the corner portion 26A of the L-shaped electrode 26. The end portion on the electrode 26 side of the wiring 36 is configured to be drawn out from the connection portion with the electrode 26 to the side of the outer main surface (light extraction surface) of the n-AlGaN layer 14. 6 reaches the Si substrate 4 along the side surface. The wiring 36 is made of a Ti / Pt / Au film, and is electrically insulated from the semiconductor multilayer film 6 by the insulating film 28. The end of the wiring 36 on the Si substrate 4 side and the cathode power supply terminal 32 are electrically connected through a through hole 38 provided in the Si substrate 4. The through holes 34 and 38 are formed by filling Pt into through holes formed in the thickness direction of the Si substrate 4.

The phosphor film 8 is formed so as to be received by the Si substrate 4 so as to cover the side surface of the semiconductor multilayer film 6 and the main surface (light extraction surface) opposite to the Si substrate. The phosphor film 8 is made of, for example, (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu ²⁺ or (Ba, Sr, Ca, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ as a blue phosphor on a translucent resin such as silicone. : At least one kind from Eu ^{2+ and the} like, green phosphors such as BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ and (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ etc., and yellow phosphors such as (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ at least one kind, red phosphors such as La ₂ O ₂ S: Eu ³⁺ and CaS: Eu ²⁺ (Ca, Sr, Ba) ₃ Si ₅ N ₈ : Eu ²⁺ From at least one kind of phosphor powder of a total of four colors and metal oxide fine particles such as SiO ₂ are dispersed. Note that an epoxy resin or a polyimide resin may be used as the translucent resin. The phosphor film 8 has a substantially uniform thickness throughout.

A light reflecting film 40 made of Al is formed between the Si substrate 4 and the phosphor film 8 around the semiconductor multilayer film 6.
In the LED chip 2 having the above configuration, when the power is supplied through the anode power supply terminal 30 and the cathode power supply terminal 32, near-ultraviolet light having a wavelength of 390 nm is emitted from the light emitting layer 12 of the semiconductor multilayer film 6. Most of the near ultraviolet light emitted from the light emitting layer 12 is emitted from the n-AlGaN layer 14 side and absorbed by the phosphor film 8. Near ultraviolet light is converted into white light by the phosphor film 8.

  As described above, the thickness of the phosphor film 8 is sufficiently thick at 200 μm compared to the thickness of the semiconductor multilayer film 6 being less than 3 μm. A phosphor film 8 is also provided on the outer periphery of the side surface of the semiconductor multilayer film 6. Therefore, the phosphor film 8 is formed with a substantially uniform thickness around the semiconductor multilayer film 6, thereby obtaining white light with little color unevenness due to the thickness unevenness of the phosphor film 8. be able to.

  In the LED chip 2 of the present embodiment, the light extraction efficiency from the semiconductor multilayer film 6 is greatly improved by adopting the high reflectivity electrode 16 as the p-side electrode. The light extraction efficiency from the semiconductor multilayer film 6 is also improved by the concavo-convex structure 22 provided on the upper surface of the n-AlGaN layer 14 serving as a light extraction surface. Further, the light reflection film 40 improves the light extraction efficiency from the LED chip 2.

  Furthermore, since the LED chip 2 is not provided with a sapphire substrate or the like on the light extraction surface side of the semiconductor multilayer film 6, the light from the light emitting layer is emitted to the outside of the LED chip via the sapphire substrate or the like. Compared to the above, the light extraction efficiency from the semiconductor multilayer film 6 is very high. In addition, since the p-side electrode (high reflectivity electrode 16) is disposed on substantially the entire surface of the p-GaN layer, which is generally considered difficult to reduce the resistance, a current is uniformly injected into the entire semiconductor multilayer film 6. Therefore, the entire semiconductor light emitting layer 12 emits light uniformly, and the operating voltage can be lowered.

  As will be described later, the LED chip 2 is mounted by directly bonding the power supply terminals 30 and 32 to the pads on the mounting substrate. Here, since the LED chip 2 itself has a phosphor film and can emit white light, the above-described optical characteristic inspection can be performed before the LED chip 2 is mounted. It is possible to prevent the finished product including the mounting substrate from being defective (non-standard) due to the special characteristics. As a result, the yield of finished products is improved. In addition, it is possible to realize a reduction in size as compared with the above-described conventional substrate that requires a submount substrate in addition to the base substrate that directly supports the semiconductor multilayer film.

  Further, the LED chip 2 has an anode power supply terminal 30 and a cathode power supply terminal 32 on the lower surface side of the semiconductor multilayer film 6, and in the mounted state, the upper surface side that becomes the light extraction side blocks the emitted light such as a bonding wire. Therefore, light without shadow can be emitted.

  A method for manufacturing the LED chip 2 having the above configuration will be described with reference to FIGS. In FIGS. 2 to 7, reference numerals in the 1000s are assigned to the material parts that are the constituent parts of the LED chip 2, and the numbers assigned to the corresponding constituent parts of the LED chip 2 are used as the last two digits. I will do it.

  First, using an organic metal chemical vapor deposition method (MOCVD method), as shown in FIG. 2, an n-AlGaN layer 1014, an InGaN / AlGaN multiple quantum well light emitting layer 1012, p on a sapphire substrate 42 which is a single crystal substrate. -AlGaN layers 1010 are stacked in this order by crystal growth [step (a)]. The sapphire substrate 42 is a substrate having a diameter of 2 inches and a thickness of 300 μm.

  Next, a part of the grown semiconductor multilayer film 1006 is masked, and the remaining part is removed by dry etching until the sapphire substrate 42 appears. The semiconductor multilayer film remaining at this time becomes individual semiconductor multilayer films 6 (see FIG. 1B) constituting the LED chip 2 [step (b)].

Subsequently, an Rh / Pt / Au film is formed on the upper surface of each semiconductor multilayer film 6 (p-AlGaN layer 10) by an electron beam evaporation method or the like, and the high reflectivity electrode 16 is produced [step (c)].
In parallel with the steps (a) to (c), the step (d) and the step (e) shown in FIG.

  Holes 44 and 46 are formed in the thickness direction of the high resistance Si substrate 1004 by dry etching, and the holes 44 and 46 are filled with Pt by electroless plating to form through holes 34 and 38. [Step (d)].

  Next, a Ti / Pt / Au film is formed in a predetermined range on the upper surface of the Si substrate 1004 to produce a conductive film 18. Further, an Au / Sn film is formed on the predetermined range of the conductive film 18 to form a bonding layer 20. Prepare [Step (e)].

  Subsequently, the sapphire substrate 42 and the Si substrate 1004 are stacked and pressed so that the high reflectance electrode 16 on the sapphire substrate 42 and the corresponding bonding layer 20 on the Si substrate 1004 overlap, and the bonding layer 20 is pressed. Is heated to about 300 ° C. [step (f)]. Thereby, the high reflectivity electrode 16 and the bonding layer 20 are eutectic bonded.

  Subsequent to the bonding of the high reflectivity electrode 16 and the bonding layer 20, the process of separating the sapphire substrate 42 from the semiconductor multilayer film 6 is entered [step (g)]. A YAG laser third harmonic beam LB having a wavelength of 355 nm is irradiated from the sapphire substrate 42 side so as to scan the entire surface of the sapphire substrate 42. The irradiated laser beam is not absorbed by the sapphire substrate 42 but is absorbed only at the interface between the sapphire substrate 42 and the n-AlGaN layer 14, and the bonding of AlGaN near the interface is decomposed by local heat generation. As a result, the sapphire substrate 42 is separated from the semiconductor multilayer film 6 in terms of crystal structure [step (g)]. At this time, the sapphire substrate 42 and the semiconductor multilayer film 6 are separated from each other in terms of crystal structure, but are attached via a layer containing metal Ga (pyrolysis layer). Can be dissolved and completely separated [step (h)]. In addition to the third harmonic of the YAG laser, a KrF excimer laser with a wavelength of 248 nm or a mercury lamp emission line with a wavelength of 365 nm can be used.

  As described above, by separating the sapphire substrate 42 and transferring the semiconductor multilayer film 6 and the like from the sapphire substrate 42 to the Si substrate 1004, the difference in lattice constant between the n-AlGaN layer 14 and the sapphire substrate 42. The internal stress generated in the semiconductor multilayer film 6 due to this is eliminated. Thereby, the semiconductor multilayer film 6 with less distortion can be obtained. Further, the degree of freedom in selecting a substrate (base substrate) that supports the semiconductor multilayer film in the LED chip is increased. For example, a substrate having higher heat dissipation (higher thermal conductivity) than that used for crystal growth is adopted as the base substrate. It becomes possible.

  Subsequently, in step (i), a silicon nitride film is formed by high-frequency sputtering or the like for the purpose of insulation and surface protection, and the insulating film 28 is produced. The silicon nitride film is formed across the periphery of the upper surface of the semiconductor multilayer film 6 (n-AlGaN layer 14), the side surface of the semiconductor multilayer film 6, and the extending portion 18A of the conductive film 18.

Next, a Ti / Pt / Au film is formed to produce the electrode 26 and the wiring 36 [step (j)]. That is, the electrode 26 and the wiring 36 are integrally formed.
An Al film is formed to produce the light reflecting film 40 [step (k)].

After depositing a tantalum oxide (Ta ₂ O ₅ ) film 24 on the exposed surface of the n-AlGaN layer 14 by sputtering or the like, a part thereof is removed by etching to form the concavo-convex structure 22 [step (l)].

  Subsequently, the first polymer film 48 is formed on the front side of the Si substrate 1004 where the semiconductor multilayer film 6 is formed via an adhesive layer (not shown) made of, for example, polyester, which foams and loses adhesive strength when heated. Adhere [process (m)].

  After the first polymer film 48 is bonded, polishing is performed from the back side until the thickness of the Si substrate 1004 reaches 100 μm [step (n)]. As a result, the through holes 34 and 38 appear on the back side of the Si substrate 1004.

When the through holes 34 and 38 appear, a Ti / Au film is formed in a predetermined region of the Si substrate 1004, and the anode feeding terminal 30 and the cathode feeding terminal 32 are produced [step (o)].
Next, the first polymer film 48 attached to the front side of the Si substrate 1004 is peeled off, and the second polymer film 50 that is a dicing sheet is attached to the back side of the Si substrate 1004 [step (p)]. .

Subsequently, after forming the phosphor film 8 by screen printing [step (q)], the LED chip 2 is completed by dicing into individual pieces by the dicing blade DB [step (r)].
(Embodiment 2)
In the LED chip 2 according to the first embodiment, both the anode and cathode feeding terminals are provided on the back side of the Si substrate 4 as the base substrate, but the white LED chip 102 according to the second embodiment (hereinafter simply referred to as “ The LED chip 102 ”is provided with one power supply terminal (in this example, an anode power supply terminal) on the back side of the base substrate and the other power supply terminal (in this example, the cathode power supply terminal) on the front side of the base substrate. This is a point that is greatly different from the first embodiment.

  The composition and thickness of each layer constituting the semiconductor multilayer film and the composition of the phosphor film employed are the same as those in the first embodiment, but the structure of the electrodes formed on both surfaces of the semiconductor multilayer film is different. ing. The semiconductor multilayer film is formed by transferring a semiconductor multilayer film formed on a single crystal substrate different from the base substrate to the base substrate, as in the case of the first embodiment.

  FIG. 8A shows a plan view of the LED chip 102 according to the second embodiment, and FIG. 8B shows a cross-sectional view taken along the line BB. FIG. 8A shows a state where the phosphor film 108 (FIG. 8B) is removed.

  As shown in FIG. 8, the LED chip 102 has a configuration in which a semiconductor multilayer film 106 and a phosphor film 108 are provided on an n-type SiC substrate 104 (hereinafter simply referred to as “SiC substrate 104”) serving as a base substrate. I am doing. SiC substrate 104 has a main surface that is slightly larger in area than the main surface of semiconductor multilayer film 106, and semiconductor multilayer film 106 is arranged in the middle of one main surface of SiC substrate 104.

  The semiconductor multilayer film 106 is composed of a p-AlGaN layer 110, an InGaN / AlGaN multiple quantum well light emitting layer 112, and an n-AlGaN layer 114 in this order from the SiC substrate 104 side, and constitutes a diode structure.

On the lower surface of the p-AlGaN layer 110, a dielectric multilayer film 116 made of SiO ₂ / Ta ₂ O ₅ and a high reflectivity electrode 118 made of Rh / Pt / Au are formed. The dielectric multilayer film 116 is formed by partially removing a single dielectric multilayer film in a predetermined pattern by selective etching. The dielectric multilayer film 116 and the p-AlGaN layer 110 are removed at a portion where the dielectric multilayer film is removed. The reflectance electrode 118 is electrically connected. A conductive film 120 which is a conductive member is formed in a region corresponding to the high reflectivity electrode 118 on the upper surface of the SiC substrate 104. The conductive film 120 is made of Ti / Pt / Au, and is bonded to the high reflectivity electrode 118 via a bonding layer 122 made of a conductive material such as Au / Sn. An anode feeding terminal 124 made of a Ti / Au film is formed on the entire lower surface of the SiC substrate 104. Therefore, high reflectivity electrode 118 and anode power supply terminal 124 are electrically connected via bonding layer 122, conductive film 120, and SiC substrate 104.

On the other hand, an ITO transparent electrode 126 is formed on the upper surface of the n-AlGaN layer 114, and subsequently, a dielectric multilayer film 128 made of SiO ₂ / Ta ₂ O ₅ is disposed.
Further, an insulating film 130 made of SiO ₂ is formed on the upper surface of the SiC substrate 104 excluding the formation region of the semiconductor multilayer film 106, and the entire side surface of the semiconductor multilayer film 106 and a part of the upper surface (the upper surface extends along the outer periphery). In this way, an insulating film 132 made of silicon nitride is formed.

On the insulating film 130, as shown in FIG. 8A, a rectangular cathode power supply terminal 134 is formed. The cathode power supply terminal 134 is made of a Ti / Pt / Al film.
Then, one side of the ITO transparent electrode 126 and one side of the cathode power supply terminal 134 are connected mainly by a wiring 136 arranged along the side surface of the semiconductor multilayer film 106. The wiring 136 is made of a Ti / Pt / Al film, and is electrically insulated from the semiconductor multilayer film 106 by the insulating film 132.

On the insulating film 132, a light reflection film 138 is formed in a “U” shape so as to surround the semiconductor multilayer film 106. The light reflecting film 138 is made of a Ti / Pt / Al film.
The phosphor film 108 is formed so as to be received by the SiC substrate 104 so as to cover the side surface of the semiconductor multilayer film 106 and the main surface (light extraction surface) opposite to the SiC substrate 104. As shown in FIG. 8B, most of the cathode power supply terminal 134 is exposed from the phosphor film 108.

  In the LED chip 102 configured as described above, near-ultraviolet light having a wavelength of 390 nm is emitted from the light emitting layer 112 of the semiconductor multilayer film 106 when power is supplied through the anode power supply terminal 124 and the cathode power supply terminal 134.

  Here, in the present embodiment, the semiconductor multilayer film 106 is arranged between the mirror structures composed of the dielectric multilayer films 116 and 128. The reflectivity of the mirror structure on the p-AlGaN layer 110 side is 99% or more, and the reflectivity of the mirror structure on the n-AlGaN layer 114 side is 90% or more, which constitutes a resonant LED structure. Near-ultraviolet light having a wavelength of 390 nm emitted from the light emitting layer 112 is emitted from the dielectric multilayer 128 having a lower reflectivity provided on the n-AlGaN layer 114 side and is absorbed by the phosphor layer 108. Near ultraviolet light is converted into white light by the phosphor layer 108.

  Therefore, the LED bare chip 102 according to Embodiment 2 has good light extraction efficiency in the direction perpendicular to the light emitting layer 112 due to the resonant LED structure. In general, when the p-AlGaN layer or the n-AlGaN layer is thinned, the spread of the current in the lateral direction tends to be non-uniform, which can hinder uniform light emission within the light-emitting surface. In particular, this tendency becomes more prominent as the light emitting area becomes wider. In the present embodiment, the p-AlGaN layer side is partially removed from the dielectric multilayer film, so that power is supplied from the high reflectivity electrode formed over the entire surface, and the n-AlGaN layer side is also applied to the entire surface. Power is supplied from the ITO transparent electrode. As a result, since the current can be uniformly injected into the entire semiconductor light emitting layer 112, the entire semiconductor light emitting layer 112 emits light uniformly, and the operating voltage can be lowered. Furthermore, since an insulating substrate such as a sapphire substrate is not included, the electrostatic withstand voltage is improved.

  The LED chip 102 is mounted by directly joining the anode power supply terminal 124 to a pad on the mounting substrate and connecting another pad and the cathode power supply terminal 134 with a bonding wire. Here, since the LED chip 102 itself has a phosphor film and can emit white light, the above-described optical characteristic inspection can be performed before mounting the LED chip 102, and the optical It is possible to prevent a finished product including a mounting board from becoming defective (non-standard) due to the physical characteristics, and as a result, the yield of the finished product is improved. This is the same as the case of 1. In addition, as in the first embodiment, it is possible to realize downsizing as compared with the above-described conventional substrate that requires a submount substrate in addition to the base substrate that directly supports the semiconductor multilayer film.

  In the LED chip 102, the anode power supply terminal 124 is disposed on the back surface of the SiC substrate 104, and the cathode power supply terminal 132 is disposed on the top surface of the SiC substrate 104. That is, both feeding terminals are arranged closer to the SiC substrate 104 side than the light extraction surface of the semiconductor multilayer film 106, and the anode feeding terminal 124 is connected to the p-side electrode (high reflectance electrode 118) via the SiC substrate 104. The cathode feeding terminal 132 is connected to the n-side electrode (ITO transparent electrode 126) and the wiring 136 drawn from the ITO transparent electrode 126 to the light extraction surface side of the n-AlGaN layer 114. Since they are connected, there is nothing blocking the emitted light such as a bonding wire on the upper surface side which is the light extraction side in the mounted state, and light without shadow can be emitted.

  A method for manufacturing the LED chip 102 having the above configuration will be described with reference to FIGS. In FIGS. 9 to 14, the material parts that are the constituent parts of the LED chip 102 are given reference numerals in the 2000 series, and the lower three digits are the numbers assigned to the corresponding constituent parts of the LED chip 102. I will do it.

  First, using an organic metal chemical vapor deposition method (MOCVD method), as shown in FIG. 9, an n-AlGaN layer 2114, an InGaN / AlGaN multiple quantum well light emitting layer 2112, p on a sapphire substrate 140 which is a single crystal substrate. -The AlGaN layer 2110 is stacked in this order by crystal growth [step (a)]. The sapphire substrate 140 is a substrate having a diameter of 2 inches and a thickness of 300 μm.

  Next, a part of the grown semiconductor multilayer film 2106 is masked, and the remaining part is removed by dry etching until the sapphire substrate 140 appears. The semiconductor multilayer film remaining at this time becomes individual semiconductor multilayer films 106 (see FIG. 8B) constituting the LED chip 102 [step (b)].

A dielectric multilayer film made of SiO ₂ / Ta ₂ O _{5 is} formed on the upper surface of each semiconductor multilayer film 106 (p-AlGaN layer 110) by RF sputtering or the like, and is then partially etched by selective etching. Until the dielectric multilayer film 116 is formed [step (c)]. Further, an Rh / Pt / Au film is formed thereon by electron beam vapor deposition or the like to produce a high reflectivity electrode 118 [step (d)].

In parallel with the above-described steps (a) to (d), the step (e) shown in FIG. 10 is advanced.
After an SiO ₂ film is formed on the entire surface of one surface of the n-type SiC substrate 2104, the insulating film 130 is formed by removing the SiO ₂ film portion corresponding to the region where the conductive film 120 is to be formed. Then, a Ti / Pt / Au film is formed on the removed portion to produce the conductive film 120, and an Au / Sn film 2122 is further formed thereon [step (e)].

  Subsequently, the sapphire substrate 140 and the SiC substrate 2104 are stacked and pressed so that the high reflectivity electrode 118 on the sapphire substrate 140 and the corresponding Au / Sn film 2122 on the SiC substrate 1104 overlap, while Au / Sn film 2122 is heated to about 300 ° C. [step (f)]. As a result, the high reflectivity electrode 118 and the Au / Sn film 2122 are eutectic bonded, and the Au / Sn film 2122 becomes the bonding layer 122, so that the high reflectivity electrode 118 and the conductive film 120 are physically and electrically connected. Will be connected.

  Subsequent to the bonding of the high reflectance electrode 118 and the bonding layer 122, the step (g) and the step (h) are performed to separate the sapphire substrate 140 from the semiconductor multilayer film 106. Since the steps (g) and (h) are the same as the steps (g) and (h) (FIG. 4) described in Embodiment 1, the description thereof is omitted.

  When the sapphire substrate 140 is separated by the steps (g) and (h) and the semiconductor multilayer film 106 and the like are transferred from the sapphire substrate 140 to the SiC substrate 2104, the process proceeds to step (i). In step (i), the surface in contact with the sapphire substrate 140 is flattened by a mechanical or chemical method, and then an ITO film is formed on the upper surface of the n-AlGaN layer 114 by sputtering or the like to produce the ITO transparent electrode 126. To do.

Further, a dielectric multilayer film 116 is formed thereon by sputtering or the like [step (j)].
A silicon nitride film is formed by sputtering or the like to produce the insulating film 132 [step (k)].

Subsequently, a Ti / Pt / Al film is deposited in a predetermined region to simultaneously form the cathode power supply terminal 134, the wiring 136, and the light reflecting film 138 [step (l)].
Next, as in the case of the first embodiment, the first polymer film 142 is bonded to the front side of the SiC substrate 2104 where the semiconductor multilayer film 106 is formed [step (m)].

  After the first polymer film 142 is adhered, after polishing from the back side until the thickness of the SiC substrate 2104 reaches 100 μm, the Ti / Au serving as the anode feeding terminal 124 (FIG. 8B) is applied to the back side. A film 2124 is formed [step (n)].

  Next, the first polymer film 142 attached to the front side of the SiC substrate 2104 is peeled off, and the second polymer film 144 that is a dicing sheet is attached to the back side of the SiC substrate 2104 [step (o)]. .

Subsequently, after forming the phosphor film 108 by screen printing [step (p)], the LED chip 102 is completed by dicing into individual pieces by the dicing blade DB [step (q)].
(Embodiment 3)
FIG. 15A is a plan view of a white LED array chip 202 (hereinafter referred to as “LED array chip 202”) which is a semiconductor light emitting device, and FIG. 15B is an LED array in FIG. It is sectional drawing which cut | disconnected the chip | tip 202 by CC line. In addition, the said sectional drawing is represented substantially similarly also when cut | disconnected along the E * E line or the F * F line in Fig.15 (a). FIG. 15A shows a state excluding a phosphor layer 208 (see FIG. 15B) described later.

  As shown in FIG. 15, the LED array chip 202 includes nine LEDs (D1 to D9) arranged in a matrix of 3 rows and 3 columns. The size of the LED array chip 202 is about 1.2 mm square. Each of D1 to D9 has basically the same configuration as the LED chip 2 of Embodiment 1 except that the uneven structure for improving the light extraction efficiency and the pattern of the n-side electrode are different. As shown in FIG. 15 (c), D1 to D9 are connected in series in the row direction, and connected in parallel, so-called series / parallel connection to form an LED array. Yes. In addition, the connection aspect between each LED is mentioned later.

As shown in FIG. 15B, the LED array chip 202 has an AlN substrate 204 as a base substrate that supports the semiconductor multilayer film.
As with the LED chip 2 (FIG. 1) of the first embodiment, the semiconductor multilayer film 206 constituting each LED is formed in order from the AlN substrate 204 side, as in the p-AlGaN layer 210, the InGaN / AlGaN multiple quantum well light emitting layer 212, n. -It consists of an AlGaN layer 214. The p-AlGaN layer 210 is provided with a p-side electrode 216 that is a high reflectance electrode made of Rh / Pt / Au. On the other hand, a conductive film 218 made of Ti / Pt / Au is formed on the surface of the AlN substrate 204, and the conductive film 218 and the p-side electrode 216 are physically connected via a bonding layer 220 made of Au / Sn. • Electrically connected. The upper surface of the n-AlGaN layer 214 (the light extraction surface in the semiconductor multilayer film 206) is processed into irregularities so as to improve the light extraction efficiency, thereby exhibiting an irregular structure 222.

  An n-side electrode 226 made of Ti / Pt / Al is formed along one side of the upper surface of the n-AlGaN layer 214 in each semiconductor multilayer film 206. An insulating film 228 made of silicon nitride is formed so as to cover part of the upper surface and side surfaces of each semiconductor multilayer film 206.

Then, the aspect of the serial connection between D4-D6 is demonstrated.
The conductive film 218 of D4 and the n-side electrode 226 of D5 are connected by the bridge wiring 234A, the conductive film 218 of D5 and the n-side electrode 226 of D6 are connected by the bridge wiring 234B, and D4, D5, and D6 are They are connected in series. Similarly, D1, D2, and D3 are connected in series in this order, and D7, D8, and D9 are connected in series in this order.

  A cathode power supply terminal 230 made of Ti / Pt / Al is formed in the left half region of the upper surface of the AlN substrate 204 as viewed in the drawing, and an anode power supply made of Ti / Pt / Al is also formed in the right half region. A terminal 232 is formed.

  The n-side electrode 226 of D4 is electrically connected to the cathode power supply terminal 230 via the wiring 236A. Similarly, the n-side electrodes 226 of D1 and D7 are also connected to the cathode power supply terminal 230, whereby the n-side electrodes 226 of D1, D4, and D7 are electrically connected in parallel.

  The conductive film 218 of D6 extends to a position where it overlaps with the anode power supply terminal 232, and is connected at the overlapping portion. Similarly, the conductive films D3 and D9 are also connected to the anode power supply terminal 232, whereby the p-side electrodes 216 of D3, D6, and D9 are electrically connected in parallel.

  As can be seen from the above description, the cathode power supply terminal 230 and the anode power supply terminal 232 also function as wiring for connecting the LED strings connected in series to each other in parallel. Further, the cathode power supply terminal 230 and the anode power supply terminal 232 formed so as to occupy most of the region other than the region where the semiconductor multilayer film 206 is formed on the upper surface of the AlN substrate 204 also function as a light reflection film.

  The nine LEDs D1 to D9 connected in series and parallel as described above and arranged in a matrix are arranged in the middle of the AlN substrate 204 having a main surface that is slightly larger than the arrangement area. The phosphor film 208 is formed so as to cover the side surface of each LED (semiconductor multilayer film) and the main surface opposite to the AlN substrate 204 as received by the AlN substrate 204. Note that the phosphor film 208 can have a composition similar to that of the first embodiment.

A Ti / Au film 238 is formed on the back surface of the AlN substrate 204.
In the LED array chip 202 having the above configuration, when power is supplied through the cathode power supply terminal 230 and the anode power supply terminal 232, near ultraviolet light having a wavelength of 390 nm is emitted from each of the light emitting layers 212 of D1 to D9. Most of the near ultraviolet light emitted from the light emitting layer 212 is emitted from the n-AlGaN layer 214 side and absorbed by the phosphor film 208. Near ultraviolet light is converted into white light by the phosphor film 208.

  In the LED array chip 202, the light extraction efficiency from the semiconductor multilayer film 206 is greatly improved by configuring the p-side electrode 216 with a high reflectance electrode. The light extraction efficiency from the semiconductor multilayer film 206 is also improved by the concavo-convex structure 222 provided on the upper surface of the n-AlGaN layer 214 serving as a light extraction surface. Further, the light extraction efficiency from the LED array chip 202 is improved by the cathode power supply terminal 230 and the anode power supply terminal 232 that function as a light reflecting film.

  The LED array chip 202 is mounted by directly bonding a Ti / Au film 238 to a pad on the mounting substrate. The power supply pad formed on the mounting substrate is connected to the cathode power supply terminal 230 and the anode power supply terminal 232 by wire bonding.

  Here, the LED array chip 202 itself has a phosphor film, and the effects produced by being able to emit white light are the same as those in the first and second embodiments described above.

  A method for manufacturing the LED array chip 202 having the above configuration will be described with reference to FIGS. In FIGS. 16 to 19, a material part that is each constituent part of the LED array chip 202 is assigned a number in the 3000 series, and the last three digits are a number assigned to a corresponding constituent part of the LED array chip 202. Will be used.

  First, using a metal organic chemical vapor deposition method (MOCVD method), as shown in FIG. 16, an n-AlGaN layer 3214, an InGaN / AlGaN multiple quantum well light emitting layer 3212, p on a sapphire substrate 240 which is a single crystal substrate. -AlGaN layers 3210 are stacked in this order by crystal growth [step (a)]. The sapphire substrate 240 is a substrate having a diameter of 2 inches and a thickness of 300 μm.

  Next, a part of the grown semiconductor multilayer film 3206 is masked, and the remaining part is removed by dry etching until the sapphire substrate 240 appears. The semiconductor multilayer film remaining at this time becomes individual semiconductor multilayer films 206 (see FIG. 15B) constituting the LED array chip 202 [step (b)].

Subsequently, an Rh / Pt / Au film is formed on the upper surface of each semiconductor multilayer film 206 (p-AlGaN layer 210) by an electron beam evaporation method or the like, and a p-side electrode 216 is produced [step (c)].
In parallel with the steps (a) to (c), the step (d) shown in FIG.

  In step (d), a Ti / Pt / Au film is formed in a predetermined range on the upper surface of the AlN substrate 3204 to produce the conductive film 218, and Au / Sn that becomes the bonding layer 220 is formed on a part of the conductive film 218. A film 3220 is formed. On the other hand, a Ti / Au film 2238 is formed on the entire back surface of the AlN substrate 3204 by plating.

  Subsequently, the sapphire substrate 240 and the AlN substrate 3204 are stacked and pressed so that the p-side electrode 216 on the sapphire substrate 240 and the corresponding Au / Sn film 3220 on the AlN substrate 3204 overlap, and Au / The Sn film 3220 is heated to about 300 ° C. [Step (e)]. As a result, the p-side electrode 3216 and the Au / Sn film 3220 are eutectic bonded, and the Au / Sn film 3220 becomes the bonding layer 220 to physically and electrically connect the p-side electrode 216 and the conductive film 218. Will be.

  Subsequent to the bonding of the p-side electrode 216 and the conductive film 218 via the bonding layer 220, the step (f) and the step (g) are performed to separate the sapphire substrate 240 from the semiconductor multilayer film 206. In addition, since this process (f) and (g) is the same as that of process (g), (h) (FIG. 4) demonstrated in Embodiment 1, the description is abbreviate | omitted.

  As described above, when the sapphire substrate 240 is separated and the semiconductor multilayer film 206 and the like are transferred from the sapphire substrate 240 to the AlN substrate 3204, the process proceeds to step (h). In step (h), a silicon nitride film is formed by high-frequency sputtering or the like for the purpose of insulation and surface protection, and an insulating film 228 is produced. The silicon nitride film is formed across the periphery of the upper surface of the semiconductor multilayer film 206 (n-AlGaN layer 214) and the side surface of the semiconductor multilayer film 6.

Next, the concavo-convex structure 222 is formed by subjecting the exposed surface of the n-AlGaN layer 214 to anisotropic etching using a KOH solution or the like [step (i)].
A Ti / Pt / Al film is formed in a predetermined region, and the n-side electrode 226, the bridge wirings 234A and B, the wiring 236, the cathode power supply terminal 230, and the anode power supply terminal 232 are manufactured simultaneously [step (j)].

  Subsequently, after forming the phosphor film 208 by screen printing [step (k)], a polymer film 242 as a dicing sheet is pasted on the back side of the AlN substrate 3204, and dicing into individual pieces by a dicing blade DB. Thus, the LED array chip 202 is completed [step (l)].

In the above embodiment, one LED array chip is composed of nine LEDs (light emitting elements) and has a size of approximately 1.2 mm square, but the number of LEDs (light emitting elements) constituting the LED array chip The size of the LED array chip is not limited to this. An LED array chip can be configured with an arbitrary number of LEDs (light emitting elements).
(Embodiment 4)
20A is a perspective view of a white LED array chip 402 (hereinafter referred to as “LED array chip 402”) according to the fourth embodiment, and FIG. 20B is a plan view thereof. In FIG. 20B, a phosphor film 406, which will be described later, is represented by a two-dot chain imaginary line. Further, in FIG. 20A and FIG. 20B, fine irregularities of the outer shape are omitted.

  As shown in FIG. 20A and FIG. 20B, the LED array chip 402 is provided with a semiconductor multilayer film having an overall columnar shape on a Si substrate 404 that is a semiconductor substrate. A phosphor film 406 is disposed around the multilayer film. Hereinafter, the substantially multilayered semiconductor multilayer film portion on the square (in this example, square) Si substrate 404 is referred to as a “columnar portion 408”. The Si substrate 404 is 2.5 mm square and has a thickness of 200 μm.

  The columnar portion 408 is equally divided into four sectors having a central angle of about 90 degrees, and each of the equally divided portions constitutes an LED that is an independent light emitting element. Here, as shown in FIG. 20A and FIG. 20B, each of the four LEDs is distinguished by being given a reference numeral D01 to D04. D01 to D04 are connected in series on the Si substrate 404 as shown in FIG. 20C, and this connection mode will be described later.

The configuration of the LEDs D01 to D04 in the LED array chip 402 will be described with reference to cross-sectional views.
21A shows a cross-sectional view taken along the line H / H in FIG. 20B, and FIG. 21B shows a cross-sectional view taken along the line J / J. That is, FIG. 21A shows D01 and D02, and FIG. 21B shows D03 and D04. Since the configuration in the stacking direction of the semiconductor multilayer film in each LED (D01 to D04) is the same, D01 is represented here, and a description thereof will be given with reference thereto. In D02 to D04, components similar to those in D01 are assigned the same numbers as in D01, and description thereof is omitted. When distinguishing the corresponding constituent parts between D01 and D04, the numbers indicating the constituent parts are given “A” in D01, “B” in D02, “C” in D03, and “D” in D04. I will do it.

As shown in FIG. 21A, the semiconductor multilayer film 410A includes, in order from the Si substrate 404 side, a p-GaN cladding layer 412A (Mg doping amount 1 × 10 ¹⁹ cm ⁻³ , thickness 200 nm), InGaN (thickness). 2 nm) / GaN (thickness 8 nm), including a multi-quantum well light-emitting layer 414A having 6 periods and an n-GaN cladding layer 416A (Si doping amount 3 × 10 ¹⁸ cm ⁻³ , thickness 200 nm).

  A p-side electrode 418A is provided on the Si substrate 404 side of the p-GaN cladding layer 412A via a p-GaN contact layer (not shown). The p-side electrode 418A is made of an Rh / Pt / Au film stacked in order from the p-GaN cladding layer 412A side, and also functions as a light reflecting film that reflects light from the light emitting layer 414A with high reflectivity.

  Note that the n-GaN cladding layer 416A, the light emitting layer 414A, the p-GaN cladding layer 412A, and the p-side electrode 418A are formed on a single crystal substrate different from the Si substrate 404, as described later. It is transferred to the substrate 404. The single crystal substrate is an n-GaN substrate, but a part of the single crystal substrate remains as a concavo-convex structure 420A for improving light extraction efficiency.

  On the other hand, on the upper surface of the Si substrate 404, a silicon oxide film 422 which is an insulating film, a wiring 424A, and a mounting pad 426A are formed in this order. Both the wiring 424A and the mounting pad 426A are composed of a Ti / Pt / Al film.

The mounting pad 426A and the p-side electrode 418A are bonded via a bonding layer 428A made of Au / Sn that is a conductive material.
An arc-shaped n-side electrode 430A is provided in a partial region on the top surface of the concavo-convex structure 420A (a region that borders a sectoral arc portion (see FIG. 20B)).

A polyimide film 432A that is an insulating film is formed on the side surface of the multilayer structure portion from the uneven structure 420A to the bonding layer 428A.
A silicon nitride film 434 that is an insulating film is formed in a predetermined region on the upper surface of the Si substrate 404 and a predetermined region on the upper surface of the wiring 424A.

The above is a configuration that is basically common to the LEDs (D01 to D04), although the details are partially different.
D01 to D04 are connected in series as shown in FIG. 20 (c), but (i) a connection mode between D01 at the low potential side end and a cathode side feeding terminal 436 described later, and (ii) a high potential. Next, the connection mode between the side end D04 and the anode power supply terminal 440 described later, and (iii) the connection mode between D01 to D04 will be described.
(I) Connection of D01 at the low potential side end and the cathode side power supply terminal 436 As shown in FIGS. 20B and 21A, a silicon oxide film 422, a silicon nitride film are formed on the upper surface of the Si substrate 404. A cathode-side power supply terminal 436 is formed via 434. The cathode power supply terminal 436 is made of a Ti / Pt / Al film.

The cathode-side power supply terminal 436 and the D01 n-side electrode 430A are electrically connected by a wiring 438A made of a Ti / Pt / Al film. Note that the wiring 438A, the n-side electrode 430A, and the cathode-side power supply terminal 436 are integrally formed at the same time in the same process as described later.
(Ii) Connection between D04 at the high potential side end and the anode power supply terminal 440 As shown in FIGS. 20B and 21B, the anode side power supply terminal 440 is formed on the upper surface of the Si substrate 404. Yes. The wiring 424D below D04 extends to the lower side of the anode-side power supply terminal 440, and is electrically connected to the anode-side power supply terminal 440 at the extended portion. As a result, the anode-side power supply terminal 440 and the p-side electrode 418D of D04 are electrically connected via the wiring 424D, the mounting pad 426D, and the bonding layer 428D.
(Iii) Connection mode between D01 and D04 Since the connection mode between D01 and D02, between D02 and D03, and between D03 and D04 are basically the same, here, referring to FIG. A connection mode between D01 and D02 will be described as a representative.

  The wiring 438B connected to the n-side electrode 430B of D02 is wired through the polyimide film 432B on the side surface of the semiconductor multilayer film 410B constituting the D02, and further extended to the opening 434H of the silicon nitride film 434. Yes. And the front-end | tip part of the wiring 438B and the wiring 424A extended from just under D01 are connected.

  As a result, the p-side electrode 418A of D01 and the n-side electrode 430B of D02 are electrically connected through the wiring 438B, the wiring 424A, the mounting pad 426A, and the bonding layer 428A.

  Similarly to the above, D03 and D04 are connected via a wiring 438D (see FIG. 21B), and D02 and D03 are connected via a wiring 438C (see FIG. 27P).

As described above, D01 to D04 are connected in series as shown in FIG.
In the LED array chip 402 having the above configuration, when power is supplied from the anode side power supply terminal 440 and the cathode side power supply terminal 436, blue light having a wavelength of 460 nm is emitted from the light emitting layers 414A to D of the LEDs D01 to D04. Since D01 to D04 are obtained by dividing the columnar portion 408 into four equal parts, the areas of the light emitting layers 414A to 414D in the respective D01 to D04 are almost the same. Therefore, the density of the current flowing through each LED (D01 to D04) is also substantially the same, and uniform brightness can be obtained between D01 and D04. As a result, illuminance unevenness on the irradiated surface is prevented.

A phosphor film 406 is formed on the upper surface (LED-side main surface) of the Si substrate 404 so as to cover the upper surface and side surfaces (including the gaps between the LEDs) of the columnar portion 408. The phosphor film 406 is made of (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ yellow phosphor powder and SiO ₂ fine particles dispersed in a translucent resin such as silicone. The phosphor film 406 has a substantially uniform thickness throughout. That is, the thickness of the phosphor film 406 covering the top surface of the columnar portion 408 is substantially equal to the thickness covering the side surface. Note that the translucent resin is not limited to silicone, and an epoxy resin or a polyimide resin may be used.

  Part of the blue light emitted from the light emitting layer 414 of each LED (D01 to D04) is converted into yellow light by the phosphor in the phosphor film 406. The blue light from the LED and the yellow light from the phosphor are combined (mixed) to generate white light.

  At this time, in the LED array chip 402, the semiconductor multilayer film including the light emitting layer is formed in a substantially cylindrical shape, and the phosphor film 406 is formed with a substantially uniform thickness with respect to the semiconductor multilayer film (that is, Since the phosphor film 406 has a bottomed cylindrical shape.), The spot shape of light obtained from the LED array chip 402 is also substantially circular. Therefore, the LED array chip 402 is suitable as an illumination light source.

  In addition, since the n-GaN cladding layer 416 side is the light extraction side, and a high-reflectance electrode is employed for the p-side electrode 418 provided facing the substantially entire surface of the p-GaN cladding layer 412, the p The blue light emitted toward the side electrode 418 is reflected by the p-side electrode 418 toward the light extraction surface side. Thereby, the light extraction efficiency in each LED improves.

A Ti / Pt / Au film 442 is formed on the lower surface of the Si substrate 404.
In the LED array chip 402, the Ti / Pt / Au film 442 portion is directly bonded to a pad on the mounting substrate, and one of the pair of power supply pads and the cathode side power supply pad 436, and the other pad and the anode side. The power supply pad 440 is mounted by being connected with a separate bonding wire.

  Here, the LED array chip 402 itself has a phosphor film, and the effects produced by being able to emit white light are the same as those in the first to third embodiments.

  A method of manufacturing the LED array chip 402 having the above configuration will be described with reference to FIGS. In FIGS. 22 to 27, the material parts that are the constituent parts of the LED array chip 402 are given reference numerals in the 5000 series, and the lower three digits are the numbers assigned to the corresponding constituent parts of the LED array chip 402. Will be used.

  First, an n-GaN buffer layer (not shown), an n-GaN cladding layer 5416, an InGaN / Metal Vapor Deposition Method (MOCVD method) is used on an n-GaN substrate 5420. A multi-quantum well light emitting layer 5414 having a GaN 6 period, a p-GaN cladding layer 5412, and a p-GaN contact layer (not shown) are stacked in this order [step (a)]. Note that the n-GaN substrate 5420 is a substrate having a diameter of 2 inches and a thickness of 300 μm. Step (a) shown in FIG. 22 to step (f) shown in FIG. 23 are steps for producing a material (LED chip) to be each LED (D01 to D04) constituting the LED array chip 402.

Subsequently, a groove 444 is formed by etching in order to divide the semiconductor multilayer film 5410 formed in the above step into 1 mm square [step (b)].
Next, a nitride film 446 is formed as a passivation film on the inner wall of the groove 444 [step (c)].

An Rh / Pt / Au film is formed on the upper surface of the divided semiconductor multilayer film 5410 by sputtering or the like to produce a p-side electrode 5418 [step (d)].
The n-GaN substrate 5420 is polished and adjusted to a thickness of about 100 μm [step (e)].

Subsequently, dicing is performed with a diamond blade DB to separate the chips into 1 mm square chips [step (f)]. Hereinafter, the chips separated into 1 mm squares are referred to as “intermediate chips”.
In parallel with the steps (a) to (f), the step (g) in FIG. 24 to the step (j) in FIG. 25 are performed.

  First, a Ti / Pt / Au film is formed in a predetermined region by sputtering or the like to form a wiring 5424 on a Si substrate 5404 with a silicon oxide film 5422 [step (g)]. The diameter of the Si substrate 5404 is 6 inches. Note that a large number of LED array chips 402 are manufactured with one Si substrate 5404. FIG. 24 and subsequent figures show a partial cross section of the Si substrate 5404. The cutting position of the cross section is a position corresponding to the K · K line shown in FIG. 20B in the LED array chip 402.

Next, a silicon nitride film 5434 is formed in a predetermined region [step (h)].
A mounting pad 426 is formed by forming a Ti / Pt / Au film in a predetermined region [step (i)].
Further, an Sn film 448 is formed so as to overlap the mounting pad 426 [step (j)].

  Subsequently, the intermediate chip 450 obtained in the step (f) is mounted at the position of the Sn film 448 and heated to about 300 ° C. while pressing the intermediate chip 450 against the Si substrate 5404. As a result, the Au film portion of the p-side electrode 5418 (Rh / Pt / Au film) and the Sn film 448 are eutectic bonded, and the intermediate chip 450 is fixed to the Si substrate 5404 [step (k)].

Next, the n-GaN substrate 5420 is polished to a thickness of about 10 μm [step (l)].
In the next step (m) of FIG. 26, the Si substrate 5404 is viewed from above, and regions corresponding to nine LED array chips 402 appear. In the step (m), a set of four intermediate chips 450 is formed, and a part of each intermediate chip 450 is removed by etching to form the columnar portion 408 with the four intermediate chips 450. For example, when one LED array chip 402 is manufactured with four intermediate chips 450A to 450D, a mask 452 (shaded portion) is applied as shown in the figure, and regions other than the masking are etched. The columnar part is formed by removing.

  Subsequently, the surface of the n-GaN substrate 5420 is processed to form the uneven structure 420. Further, the Si substrate 5404 is polished and adjusted to a thickness of about 200 μm. Further, a Ti / Pt / Au film 5442 is formed on the lower surface after polishing [step (n)].

Next, a polyimide film 432 is formed on the side surface of each semiconductor multilayer film [step (o)].
Subsequently, a Ti / Pt / Au film is formed in a predetermined region, and an anode-side power supply terminal 440, a cathode-side power supply terminal 436, an n-side electrode 430, and a wiring 438 are formed simultaneously [step (p)].

The phosphor film 406 is formed by screen printing or the like [step (q)].
Finally, dicing is performed for each of the four sets [step (r)] to complete the LED array chip 402 (FIG. 20).
(Embodiment 5)
FIG. 28 is an external perspective view of a white LED module (hereinafter simply referred to as “LED module”) 300 that is an illumination module having the LED chip 2 (see FIG. 1) according to the first embodiment. The LED module 300 is used by being mounted on a lighting fixture 332 (FIG. 31) described later.

  The LED module has a ceramic substrate 302 made of AlN having a circular shape with a diameter of 5 cm and 217 resin lenses 304. The ceramic substrate 302 is provided with a guide recess 306 for attaching to the lighting fixture 332 and terminals 308 and 310 for receiving power from the lighting fixture 332.

  29 (a) is a plan view of the LED module 300, FIG. 29 (b) is a cross-sectional view taken along the line GG in FIG. 29 (a), and FIG. 29 (c) is an enlarged view of the chip mounting portion in FIG. 29 (b). Each figure is shown.

As shown in FIG. 29 (c), the lower surface of the ceramic substrate 302 is provided with a gold plating 312 for improving heat dissipation characteristics.
On the ceramic substrate 302 corresponding to the center of each lens that looks circular in FIG. 29A, one LED chip 2 is mounted (a total of 217).

The ceramic substrate 302 is a ceramic substrate in which two ceramic substrates 314 and 316 having a thickness of 0.5 mm and mainly made of AlN are laminated. As materials for the ceramic substrates 314 and 316, Al ₂ O ₃ , BN, MgO, ZnO, SiC, diamond and the like can be considered in addition to AlN.

  The LED chip 2 is mounted on the lower ceramic substrate 316. The upper ceramic substrate 314 is provided with a tapered through-hole 318 that creates a space for mounting the LED chip 2.

  A cathode pad 320 and an anode pad 322 as shown in FIG. 30B are formed on the upper surface of the ceramic substrate 316 corresponding to each mounting position of the LED chip 2. Each of the pads 320 and 322 is made by performing Au plating on the surface of Cu. PbSn solder is placed on each of the pads 320 and 322, and the cathode power supply terminal 32 and the anode power supply terminal 30 (see FIG. 1) of the LED chip 2 are joined.

  Alternatively, if AuSn solder is plated on the power supply terminals 32 and 30 of the LED chip 2, a step of placing solder on the pads 320 and 322 becomes unnecessary. After the LED chips 2 are arranged on all the pads, if the temperature of the ceramic substrate 302 is raised to a temperature at which the solder can be melted through a reflow furnace, all 217 LED chips 2 can be bonded at a time. Although not mentioned here, the reflow soldering described above is possible if the shape of the pad, the amount of solder, the shape of the power supply terminal of the LED chip 2 and the like are optimized. In addition, you may join by silver paste or a bump irrespective of solder.

  Here, the LED chip 2 provided for mounting has passed optical characteristic inspections such as color unevenness and color temperature performed before mounting. That is, according to the present embodiment, since the LED chip 2 itself has a phosphor layer and can emit white light, as described above, the optical chip is mounted before the LED chip 2 is mounted. It becomes possible to execute a characteristic inspection, and it is possible to prevent the LED module from becoming a defective product (non-standard) due to the optical characteristics. As a result, the yield of the finished product (LED module) is improved.

  As shown in FIG. 29 (c), an aluminum reflective film 324 is formed on the side wall of the through hole 318 provided in the upper ceramic substrate 314 and the upper surface of the ceramic substrate 314.

  After mounting the LED chip 2 on the ceramic substrate 316, the LED chip 2 is covered with a silicone resin 326 or the like as a first resin, and a lens 304 is formed by injection molding using an epoxy resin 328 or the like as a second resin.

The 217 LED chips 2 are connected in 31 series and 7 in parallel by a wiring pattern 330 formed on the upper surface of the ceramic substrate 316.
FIG. 30A is a plan view of the LED module 300 in a state where the lens 304 and the upper ceramic substrate 314 are removed. As described above, the anode pad 322 and the cathode pad 320 (FIG. 30B) are arranged on the surface of the ceramic substrate 316 at the mounting position of each LED chip 2.

  Then, 31 LED chips 2 are connected in series between each anode pad 322 and each cathode pad 320 connected to each LED chip 2, and the 7 groups of LED chips connected in series are connected in parallel. As shown, the wiring patterns 330 are connected. One end of the wiring pattern 330 is connected to the positive terminal 308 shown in FIG. 29A via a through hole (not shown), and the other end is connected to the negative electrode shown in FIG. 29 via a through hole (not shown). The terminal 310 is connected.

  The LED module 300 configured as described above is used by being attached to the lighting fixture 332. The LED module 300 and the lighting fixture 332 constitute a lighting device 334.

FIG. 31A shows a schematic perspective view of the lighting device 334, and FIG. 31B shows a bottom view of the lighting device 334.
The lighting fixture 332 is fixed to, for example, an indoor ceiling. The lighting fixture 332 includes a power supply circuit (not shown) that converts AC power (for example, 100 V, 50/60 Hz) from a commercial power source into DC power necessary to drive the LED module 300.

The structure for attaching the LED module 300 to the lighting fixture 332 will be described with reference to FIG.
The lighting fixture 332 has a circular recess 336 into which the LED module 300 is fitted. The bottom surface of the circular recess 336 is finished to be a flat surface. A female screw (not shown) is cut in a portion near the opening of the inner wall of the circular recess 336. Further, flexible power supply terminals 338 and 340 and a guide piece 342 protrude from the inner wall between the female screw and the bottom surface. Note that the power supply terminal 338 is a positive electrode and the power supply terminal 340 is a negative electrode.

  A silicon rubber O-ring 344 and a ring screw 346 are provided as members for attaching the LED module 300 to the lighting fixture 332. The ring screw 346 has a ring shape having a substantially rectangular cross section, and a male screw (not shown) is formed on the outer periphery thereof. Further, the ring screw 346 has a notch 346A formed by cutting a part in the circumferential direction.

Subsequently, the attachment procedure will be described.
First, the LED module 300 is fitted into the circular recess 336. At this time, the ceramic substrate 302 of the LED module 300 is positioned between the power supply terminals 338 and 340 and the bottom surface of the circular recess 336, and is fitted so that the guide recess 306 and the guide piece 342 are engaged. The guide recess 306 and the guide piece 342 align the positive terminal 308 and the negative terminal 310 with the corresponding power supply terminals 338 and 340.

  When the LED module 300 is fitted, the O-ring 344 is attached, and then the ring screw 346 is screwed into the circular recess 336 and fixed. As a result, the positive electrode terminal 308 and the power supply terminal 338, the negative electrode terminal 310 and the power supply terminal 340 are in close contact with each other, and are electrically connected reliably. Further, almost the entire surface of the ceramic substrate 302 and the flat bottom surface of the circular recess 336 are in close contact with each other, so that the heat generated in the LED module 300 is effectively transmitted to the lighting fixture 332 and the cooling effect of the LED module 300 is improved. Will do. Note that silicon grease may be applied to the bottom surfaces of the ceramic substrate 302 and the circular recess 336 in order to further increase the heat transfer efficiency of the LED module 300 to the lighting fixture 332.

In the lighting device 334 having the above configuration, when power is supplied from a commercial power supply, white light is emitted from each LED chip 2 and emitted through the lens 304 as described above.
As typical characteristics when a current of 1 A was passed through the LED module 300, the total luminous flux was 4,000 lm and the central luminous intensity was 10,000 cd. The emission spectrum was as shown in FIG.

  Up to this point, examples of using the semiconductor light emitting device for lighting applications such as a lighting module and a lighting device have been introduced. However, the present invention is not limited thereto, and the semiconductor light emitting device according to the present invention can be used for display applications. That is, the semiconductor light emitting device according to the present invention may be used as a light source of a display element. Examples of the display element include a surface mount type (SMD) LED formed by packaging an LED chip. The surface-mounted LED has, for example, a structure in which a semiconductor light emitting device (LED chip) is mounted on a ceramic substrate and the semiconductor light emitting device is sealed with a transparent epoxy resin.

  The surface-mounted LEDs are used alone or in combination. Examples of single use include a case where it is mounted on a remote control of a home appliance such as a television, a video, or an air conditioner, or a case where it is used as a power lamp of the home appliance. An example in which a plurality of dots are used simultaneously is a case where the dots are used as dots in a dot matrix display device that displays characters, numbers, symbols, and the like.

As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described form, and for example, the following form is also possible.
(1) In the first to third embodiments, after a semiconductor multilayer film is formed by crystal growth on a sapphire substrate (single crystal substrate), the semiconductor multilayer film is formed on an LED (array) chip (semiconductor light emission) on the sapphire substrate. The apparatus was divided into units (FIG. 2 step (b), FIG. 9 step (b), FIG. 16 step (b)). However, the present invention is not limited to this, and the above-described division of the semiconductor multilayer film is not performed on the sapphire substrate, but a base substrate (high-resistance Si substrate 1004 (FIG. 3 etc.), n) It is also possible to perform the process on the base substrate after transferring the entire crystal multi-layered semiconductor multilayer film to the type SiC substrate 2104 (FIG. 10 and the like) and the AlN substrate 3204 (FIG. 17 and the like).
(2) In the fourth embodiment, the semiconductor multilayer film is formed in a substantially cylindrical shape. That is, by using a columnar body having five or more corners, the spot shape of the obtained light becomes closer to a circle than a square. Moreover, when setting it as N prismatic shape, it is preferable that it is regular N prismatic shape and N is an even number. This is because, as in the case of the circular shape, a spot shape that is point-symmetric can be obtained.
(3) In Embodiment 4 described above, the semiconductor multilayer film formed in the columnar body is divided into four regions to form four independent LEDs (light emitting elements). The number is not limited to four and is arbitrary. Further, it may be left in an integral columnar shape or N-prism shape without being divided. That is, it is good also as comprising one LED chip with one LED (light emitting element), without setting it as an array.

  As described above, the semiconductor light emitting device according to the present invention is suitable for the illumination field that requires optical inspection such as color unevenness before mounting.

2,102 White LED chip 4 High resistance Si substrate 6, 106, 206, 410 Semiconductor multilayer film 8, 108, 208 Phosphor film 10, 110, 210 p-AlGaN layer 12, 112, 212 InGaN / AlGaN multiple quantum well light emission Layer 14, 114, 214 n-AlGaN layer 16 High reflectivity electrode 22, 222, 420 Uneven structure 104 n-type SiC substrate 202, 402 White LED array chip 204 AlN substrate 216 p-side electrode 404 Si substrate 408 Columnar portion 412 p- GaN clad layer 414 InGaN / GaN multiple quantum well light emitting layer 416 n-GaN clad layer 418 p-side electrode (light reflecting film made of Rh / Pt / Au film)
5420 n-GaN substrate

Claims (7)

A base substrate;
Each of the base substrates is arranged in the middle of one main surface, and each of them is composed of a semiconductor multilayer film in which a first conductive type layer, a light emitting layer, and a second conductive type layer are stacked in this order from the base substrate side. A plurality of light emitting elements;
A first electrode formed on a main surface opposite to the light emitting layer of the first conductivity type layer in each of the light emitting elements;
A second electrode formed on the main surface of the second light emitting element on the side opposite to the light emitting layer;
An insulating film formed on a side surface of each light emitting element;
A first power supply terminal and a second power supply terminal formed on the one main surface of the base substrate apart from each other;
Each of the semiconductor multilayer films constituting each light emitting element is formed by crystal growth on a single crystal substrate different from the base substrate, and is separated from the single crystal substrate and transferred to the base substrate. Yes,
A second electrode of one light-emitting element and a first electrode of another light-emitting element are sequentially electrically connected by a film wiring provided on the insulating film, so that all or one of the plurality of light-emitting elements can be connected. Are connected in series,
The first electrode of the light emitting element at one end of the light emitting element row connected in series and the first power supply terminal are electrically connected,
The second electrode of the light emitting element at the other end and the second power supply terminal are electrically connected via a film wiring provided on the insulating film,
The phosphor film is formed so as to cover the side surface of each light emitting element and the main surface opposite to the base substrate, such that the phosphor film is received by the base substrate .
Each of the plurality of semiconductor multilayer films has a fan shape in a plan view, and is arranged so that the plurality of semiconductor multilayer films appear to be substantially circular in the plan view . The second electrode is formed at an edge of the main surface of the second conductivity type layer,
The film wiring for electrically connecting the second electrode of one light emitting element and the first electrode of another light emitting element is led out from the second electrode to the side of the second conductivity type layer,
The film wiring that electrically connects the second electrode of the other end of the light emitting element and the second power supply terminal is drawn out from the second electrode to the side of the second conductivity type layer. The semiconductor light emitting device according to claim 1. 2. The phosphor film according to claim 1, wherein a thickness of a portion of each semiconductor multilayer film covering a main surface opposite to the base substrate is substantially equal to a thickness of a portion covering a side surface of the fan-shaped arc portion. 2. The semiconductor light emitting device according to 1.   2. The semiconductor light emitting device according to claim 1, wherein a concavo-convex structure for improving light extraction efficiency is formed on a main surface of the second conductivity type layer opposite to the light emitting layer. A mounting board,
Lighting module semiconductor light-emitting device according to any one of claims 1 to 4, characterized in that it is mounted on the mounting substrate. An illumination device comprising the illumination module according to claim 5 as a light source. As a light source, a display element comprising the semiconductor light-emitting device according to any one of claims 1-4.

Images