JP2009152297A - Semiconductor light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device which is built in a compact package with one chip and can emit light in multiple colors with high luminance. <P>SOLUTION: Disclosed is the semiconductor light-emitting device which includes a substrate 10, a first semiconductor light-emitting element 12 disposed on the substrate 10, a stuck electrode 14 disposed on the first semiconductor light-emitting element 12, and a second semiconductor light-emitting element 16 disposed on the stuck electrode 14, wherein the substrate 10 is transparent to a light emission wavelength. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor light emitting device, and more particularly to a semiconductor light emitting device capable of emitting multicolor light.

  Multi-wavelength semiconductor light emitting devices such as light emitting diodes (LEDs) capable of emitting a plurality of different colors of light have been developed.

  For example, a manufacturing method of a one-chip type semiconductor light emitting element in which at least two light emitting layer forming portions are formed of different semiconductor materials on one semiconductor substrate has already been disclosed (for example, refer to Patent Document 1). In the semiconductor light emitting device of Patent Document 1, one of at least two light emitting layer forming portions is formed of an AlGaInP quaternary compound semiconductor layer, and the other is formed of a compound semiconductor layer made of GaP.

  On the other hand, for example, a white light emitting diode that can form a white or various mixed colors by realizing a light emitting element of two wavelengths on one substrate and can be manufactured by a simple process and a manufacturing method thereof have already been disclosed. (For example, refer to Patent Document 2). In the white light emitting diode of Patent Document 2, the active layer constituting the first light emitting part is formed of an AlGaInP quaternary compound semiconductor layer, and the active layer constituting the second light emitting part is a II-VI group. The compound semiconductor layer is formed. As a result, by growing a III-V compound semiconductor having a wavelength region of 635 to 780 nm and a II-VI compound semiconductor having a wavelength region of 450 to 550 nm on a substrate, white and various visible colors can be obtained. A wavelength band in the optical region is realized.

  Furthermore, for example, a gallium nitride-based compound semiconductor light-emitting device in which InAlGaN is laminated, in particular, a light-emitting device that can emit multicolor light with one chip has already been disclosed (see, for example, Patent Document 3). In the light emitting device of Patent Document 3, multicolor light emission is realized by doping an active layer made of InAlGaN.

  Conventionally, for light emission of two or more colors, it is necessary to perform epitaxial growth twice or to form active layers having different emission wavelengths by one epitaxial growth.

  FIG. 16A schematically shows an example of a conventional structure in which active layers having different emission wavelengths are formed by performing epitaxial growth twice when forming the first semiconductor light emitting device 12 and the second semiconductor light emitting device 16. FIG. 16B shows that when the first semiconductor light emitting element 12 and the second semiconductor light emitting element 16 are formed, continuous epitaxial growth is performed, and active layers having different emission wavelengths are formed by one epitaxial growth. An example of a conventional structure is schematically shown.

However, blue to green light emitting LEDs must be formed of gallium nitride semiconductor materials, and yellow green to red light emitting LEDs must be formed of InGaAlP semiconductor materials. It was difficult.
Japanese Patent No. 3817323 JP 2002-43624 A Patent No. 2910023

  An object of the present invention is to provide a semiconductor light emitting device that can be incorporated into a small package with one chip and can emit light with high luminance and multicolor.

  According to one aspect of the present invention for achieving the above object, a substrate, a first semiconductor light emitting element disposed on the substrate, and an adhesive electrode disposed on the first semiconductor light emitting element, There is provided a semiconductor light emitting device comprising: a second semiconductor light emitting element disposed on the pasted electrode, wherein the substrate is transparent with respect to an emission wavelength.

According to another aspect of the present invention, a substrate, a first semiconductor light emitting element disposed on the substrate, and a bonded electrode disposed on the substrate adjacent to the first semiconductor light emitting element. And a second semiconductor light emitting element disposed on the pasted electrode. A semiconductor light emitting device is provided.

  According to another aspect of the present invention, a substrate, a first semiconductor light emitting element disposed on the substrate, and a second semiconductor element disposed on the substrate adjacent to the first semiconductor light emitting element. A semiconductor light emitting element; a first affixing electrode disposed on the first semiconductor light emitting element; a second affixing electrode disposed on the second semiconductor light emitting element; And a third semiconductor light emitting element disposed on the third adhesive electrode, wherein the substrate is transparent to the emission wavelength. A semiconductor light emitting device is provided.

  According to another aspect of the present invention, a substrate, a first semiconductor light emitting device disposed on the substrate, a pasted electrode disposed on the first semiconductor light emitting device, and the pasted electrode And a third semiconductor light emitting element disposed adjacent to the second semiconductor light emitting element on the pasted electrode, and the substrate is adapted to emit light at a wavelength corresponding to the emission wavelength. And a semiconductor light emitting device characterized by being transparent.

  In the semiconductor light emitting device according to the embodiment of the present invention, a gallium nitride-based LED and an InGaAlP-based LED can be bonded to realize an LED of two or more colors.

  Since the LED on the lower side is blocked by the pasted electrode part, the light needs to be taken out from the lateral direction, so the lower side must be made a transparent substrate, and the light can be taken out from the lateral direction of the substrate. Can do. In addition, it is also possible to take out the light of lower LED (for example, blue LED) to the upper side by reducing a sticking electrode part.

  According to the present invention, it is possible to provide a semiconductor light emitting device that can be incorporated into a small package with a single chip and can improve multi-color light emission by using a highly efficient LED.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus and a method for embodying the technical idea of the present invention. The technical idea of the present invention is the arrangement of each component as described below. It is not something specific. The technical idea of the present invention can be variously modified within the scope of the claims.

  In the semiconductor light emitting device according to the following embodiments of the present invention, “transparent” is defined as having a transmittance of about 50% or more. The term “transparent” is used to mean colorless and transparent with respect to visible light in the semiconductor light emitting device according to the embodiment of the present invention. Visible light corresponds to a wavelength of about 360 nm to 830 nm and an energy of about 3.4 eV to 1.5 eV, and is transparent unless absorption, reflection, or scattering occurs in this region.

Transparency is determined by the band gap E _g and the plasma frequency ω _p . When the band gap E _g is about 3.4 eV or more, the visible light does not absorb the visible light because the transition between the electrons does not occur in the visible light. On the other hand, light having energy lower than the plasma frequency ω _p cannot enter the plasma and is reflected by carriers that can be regarded as plasma. The plasma frequency ω _p is expressed as ω _p = (nq ² / εm ^* ) ^1/2 where n is the carrier density, q is the charge, ε is the dielectric constant, and m ^* is the effective mass, and is a function of the carrier density. is there.

[First embodiment]
(Element structure)
As shown in FIG. 1A, the semiconductor light emitting device according to the first embodiment of the present invention includes a substrate 10, a first semiconductor light emitting element 12 disposed on the substrate 10, and a first semiconductor. A pasting electrode 14 disposed on the light emitting element 12 and a second semiconductor light emitting element 16 disposed on the pasting electrode 14 are provided. The substrate 10 is transparent with respect to the emission wavelength. Here, the substrate 10 can be made of, for example, sapphire or GaP.

  As shown in FIG. 1A, an electrode 18 disposed adjacent to the pasted electrode 14 is further provided on the first semiconductor light emitting element 12, and the electrode 4 is provided on the first semiconductor light emitting element 12. You may have.

  The pasted electrode 14 and the electrode 18 constitute an anode or cathode electrode of the first semiconductor light emitting element 12, and the electrode 4 and the pasted electrode 14 constitute an anode or cathode electrode of the second semiconductor light emitting element 16. The pasted electrode 14 becomes a common anode electrode or a cathode electrode.

  Further, the first semiconductor light emitting element 12 and the second semiconductor light emitting element 16 may be semiconductor light emitting elements having an emission peak wavelength of one wavelength or two wavelengths.

  In the semiconductor light emitting device according to the first embodiment of the present invention, for example, a gallium nitride LED is applied as the first semiconductor light emitting element 12, and an InGaAlP LED is used as the second semiconductor light emitting element 16. It can be applied and pasted together with the pasting electrode 14 to realize LEDs of two or more colors. Since the lower LED 1 is blocked at the portion of the pasted electrode 14 that has been pasted, it is necessary to extract the light from the lateral direction. For this reason, when the lower side is the transparent substrate 10, light can be extracted from the lateral direction of the substrate 10.

  In addition, you may further provide the transparent electrode 8 arrange | positioned on the board | substrate 10 similarly to FIG.1 (b) mentioned later. As a material of the transparent electrode 8, ZnO, ITO, or the like can be applied.

  In addition, it is also possible to take out the light of lower LED1 (for example, blue LED) to upper side by reducing the part of the bonding electrode 14. FIG.

(Modification 1)
As shown in FIG. 1B, the semiconductor light emitting device according to the first modification of the first embodiment of the present invention includes a substrate 10, a first semiconductor light emitting element 12 disposed on the substrate 10, A pasting electrode 14 disposed on the first semiconductor light emitting element 12 and a second semiconductor light emitting element 16 disposed on the pasting electrode 14 are provided. The substrate 10 is transparent with respect to the emission wavelength. The substrate 10 can be made of sapphire, GaP, or the like, for example.

  An electrode 4 may be provided on the second semiconductor light emitting element 16, and a transparent electrode 8 disposed on the substrate 10 may be further provided.

  In the semiconductor light emitting device according to the first modification of the first embodiment of the present invention, for example, a gallium nitride LED is applied as the first semiconductor light emitting element 12, and the InGaAlP is used as the second semiconductor light emitting element 16. System LEDs can be applied and pasted together with the pasting electrode 14 to realize two or more colors of LEDs. Since the lower LED 1 is blocked by the portion of the pasted electrode 14 that is pasted, it is necessary to take out light from the lateral direction. Light can be extracted.

  The pasted electrode 14 and the transparent electrode 8 constitute an anode or cathode electrode of the first semiconductor light emitting element 12, and the electrode 4 and the pasted electrode 14 constitute an anode or cathode electrode of the second semiconductor light emitting element 16. . The pasted electrode 14 becomes a common anode electrode or a cathode electrode.

  Further, the first semiconductor light emitting element 12 and the second semiconductor light emitting element 16 may be semiconductor light emitting elements having an emission peak wavelength of one wavelength or two wavelengths.

(Modification 2)
As shown in FIG. 1C, the semiconductor light emitting device according to the second modification of the first embodiment of the present invention includes a substrate 10, a first semiconductor light emitting element 12 disposed on the substrate 10, An adhesive electrode 14 disposed adjacent to the first semiconductor light emitting element 12 and a second semiconductor light emitting element 16 disposed on the adhesive electrode 14 are provided on the substrate 10. Here, the substrate 10 can be composed of, for example, sapphire, GaP, GaAs, SiC, or the like.

  The substrate 10 may be transparent to the emission wavelength. In this case, the substrate 10 can be composed of, for example, sapphire or GaP.

  As shown in FIG. 1 (c), the electrode 18 disposed on the first semiconductor light emitting element 12, the electrode 4 disposed on the second semiconductor light emitting element 16, and the electrode disposed on the substrate 10. 2 may be further provided.

  The pasted electrode 14 and the electrode 4 constitute an anode or cathode electrode of the second semiconductor light emitting element 16, and the electrode 18 and the electrode 2 constitute an anode or cathode electrode of the first semiconductor light emitting element 12. The pasted electrode 14 becomes a common anode electrode or a cathode electrode.

  Further, the first semiconductor light emitting element 12 and the second semiconductor light emitting element 16 may be semiconductor light emitting elements having an emission peak wavelength of one wavelength or two wavelengths.

  In the semiconductor light emitting device according to the second modification of the first embodiment of the present invention, for example, a gallium nitride LED is applied as the first semiconductor light emitting element 12, and the InGaAlP is used as the second semiconductor light emitting element 16. System LEDs can be applied and pasted together with the pasting electrode 14 to realize two or more colors of LEDs. Both the first semiconductor light emitting device 12 and the second semiconductor light emitting device 16 can extract light from above. In addition, the 1st semiconductor light-emitting device 12 can also take out light from lower side by using the transparent board | substrate 10. FIG.

FIG. 3 is a configuration example of the first semiconductor light emitting element 12 applied to the semiconductor light emitting device according to the first embodiment of the present invention, and a schematic cross-sectional structure in which a blue LED is formed on the sapphire substrate 10. The figure is shown. As shown in FIG. 3, an adhesive electrode 14 made of, for example, a gold (Au) layer is disposed on the first semiconductor light emitting element 12.

FIG. 4 is an example of the second semiconductor light emitting element 16 applied to the semiconductor light emitting device according to the first embodiment of the present invention, and is a schematic cross-sectional structure in which a red LED is formed on a GaAs substrate. The figure is shown. That is, the second semiconductor light emitting element 16 applied to the semiconductor light emitting device according to the first embodiment of the present invention includes a GaAs substrate 22 and a GaP disposed on the GaAs substrate 22 as shown in FIG. A layer 24, an n-type cladding layer 26 made of AlInP arranged on the GaP layer 24, an active layer 28 arranged on the n-type cladding layer 26, and a p-type made of AlInP arranged on the active layer 28. The clad layer 30, a GaP layer 32 disposed on the p-type clad layer 30, and a bonding electrode 34 disposed on the GaP layer 32 and made of, for example, a gold (Au) layer are provided.

FIG. 5 is a schematic diagram of a semiconductor light emitting device according to the first embodiment of the present invention, in which the blue LED shown in FIG. 3 and the red LED shown in FIG. A cross-sectional structure diagram is shown.

  The bonding conditions of the bonding electrodes 14 and 34 are, for example, about 150 ° C. to 700 ° C., desirably 200 ° C. to 400 ° C., and the pressure of thermocompression bonding is, for example, about 0.1 Pa to 10 Pa, Desirably, the pressure is about 0.1 Pa to 1.0 Pa. In the above example, an example in which the Au layer and the Au layer are bonded together is shown, but the Au layer and the Sn layer may be bonded together. As a result, as shown in FIG. 5, the pasting electrodes 14 and 34 are pasted by thermocompression bonding to form a common anode electrode 48.

  FIG. 6 is a detailed enlarged schematic cross-sectional structure diagram of parts connected by the attaching technique in FIG. As shown in FIG. 6, in the vicinity of the anode side of the first semiconductor light emitting element 12, a p-type semiconductor layer 44 made of a GaN layer, a transparent electrode 38 disposed on the p-type semiconductor layer 44, and the transparent electrode 38 And a pasting electrode 14 disposed on the reflective layer 36.

  The transparent electrode 38 is formed of, for example, a ZnO film having a thickness of about 0.1 μm to 10 μm. Further, desirably, the transparent electrode 3 is formed of a ZnO film having a thickness of about 1 μm.

The reflective layer 36 can be formed of a reflective laminated film (DBR: Distributed Bragg Reflector) having a laminated structure of λ / 4n ₁ and λ / 4n ₂ (n ₁ and n ₂ are refractive indexes of the laminated layers). As a material used for the laminated structure, for example, a laminated structure made of ZrO ₂ (n = 2.12) and SiO ₂ (n = 1.46) can be used for blue light with λ = 450 nm. In this case, the thickness of each layer is, for example, about 53 nm for ZrO ₂ and about 77 nm for SiO ₂ . As another material for forming the laminated structure, TiO ₂ , Al ₂ O ₃ or the like can be used. Furthermore, aluminum (Al) or silver (Ag) can be used as another material for forming the stacked structure.

  FIG. 7 is a specific configuration example of the semiconductor light emitting device according to the first embodiment of the present invention, in which a blue LED and a red LED are attached to form a two-color light emitting semiconductor light emitting element. A cross-sectional structure diagram is shown.

In the pasting structure of FIG. 5, after further removing the GaAs substrate 22, as shown in FIG. 7A, cathode electrodes 50 and 46 are formed, and the semiconductor light emitting device according to the first embodiment of the present invention is formed. Complete.

FIG. 7B shows the circuit configuration of FIG. 7A, in which the cathodes K1 and K2 are separated from the common anode A to constitute a semiconductor light emitting device having an anode common configuration.

  FIG. 8 shows another specific configuration example of the semiconductor light emitting device according to the first embodiment of the present invention, in which a blue LED and a red LED are attached to form a two-color light emitting semiconductor light emitting device. A schematic cross-sectional structure diagram is shown. 4 corresponds to a structure in which a structure in which the GaP layer 32 is omitted is bonded, and the stacked structure is simplified as compared with the structure in FIG. The other components are the same as those in FIG.

(Specific configuration example)
-Red LED-
As shown in FIG. 9, the red LED applicable to the semiconductor light emitting device according to the first embodiment of the present invention includes a GaAs substrate 100, a GaAs buffer layer 120 disposed on the GaAs substrate 100, and a GaAs buffer. A reflective laminated film (DBR) 140 having a laminated structure of AlInP / (AlGa) InP disposed on the layer 120, an n-type cladding layer 160 made of, for example, AlInP, disposed on the reflective laminated film 140, and an n-type cladding. For example, a multiple quantum well of (Al _x Ga _1-x ) _0.5 In _0.5 P well layer and (Al _y Ga _1-y ) _0.5 In _0.5 P barrier layer (0 ≦ x <y <1) disposed on the layer 160 An active layer 180 having a structure, a p-type cladding layer 200 made of, for example, AlInP, an InGaAlP layer 220 disposed on the p-type cladding layer 200, and In The GaP window layer 240 disposed on the aAlP layer 220, the (AlGa) InP layer 260 disposed on the GaP window layer 240 and serving as an etching stop layer, and the GaAs layer 280 disposed on the (AlGa) InP layer 260 With. The first epitaxial growth layer 300 is formed by continuous crystal growth.

―Yellow green LED―
As shown in FIG. 10, a yellow-green LED applicable to the semiconductor light emitting device according to the first embodiment of the present invention includes a GaAs substrate 100, a GaAs buffer layer 120 disposed on the GaAs substrate 100, GaAs A reflective laminated film 150 having an AlInP / (AlGa) InP laminated structure disposed on the buffer layer 120, an n-type cladding layer 170 made of, for example, AlInP, and an n-type cladding layer 170 disposed on the reflective laminated film 150. For example, a multiple quantum well structure of (Al _x Ga _1-x ) _0.5 In _0.5 P well layer and (Al _y Ga _1-y ) _0.5 In _0.5 P barrier layer (0 ≦ x <y <1) An active layer 190, a p-type cladding layer 210 made of, for example, AlInP, an InGaAlP layer 230 disposed on the p-type cladding layer 210, and an InGaA GaP window layer 250 disposed on P layer 230, (AlGa) InP layer 270 disposed on GaP window layer 250 and serving as an etching stop layer, and GaAs layer 290 disposed on (AlGa) InP layer 270 With. The second epitaxial growth layer 320 is also formed by continuous crystal growth.

―Blue LED―
The blue LED applicable to the semiconductor light emitting device according to the first embodiment of the present invention includes a substrate 10 and a buffer layer 39 disposed on the substrate 10 as shown in FIG. The buffer layer 39 is disposed, the n-type semiconductor layer 40 is doped with n-type impurities, and the block is disposed on the n-type semiconductor layer 40 and doped with the n-type impurities at a lower concentration than the n-type semiconductor layer 40. A layer 41; an active layer 42 disposed on the block layer 41; a p-type semiconductor layer 44 disposed on the active layer 42; and an oxide electrode 45 disposed on the p-type semiconductor layer 44.

  As shown in FIG. 11B, the active layer 42 has a laminated structure in which barrier layers 311 to 31n and 310 and well layers 321 to 32n having a smaller band gap than the barrier layers 311 to 31n and 310 are alternately arranged. Have. Hereinafter, the first barrier layer 311 to the n-th barrier layer 31n included in the active layer 42 are collectively referred to as “barrier layers”. Further, all the well layers 321 to 32n included in the active layer 42 are collectively referred to as “well layers”.

  The film thickness of the final barrier layer 310 in the uppermost layer of the stacked structure is larger than the thicknesses of the other barrier layers (the first barrier layer 311 to the nth barrier layer 31n) included in the stacked structure other than the final barrier layer 310. It may be formed.

  In the semiconductor light emitting device shown in FIG. 11, the concentration of the p-type dopant in the final barrier layer 310 extends from the first main surface of the final barrier layer 310 in contact with the p-type semiconductor layer 44 along the film thickness direction of the final barrier layer 310. There is no p-type dopant on the second main surface that gradually decreases and faces the first main surface.

  As the substrate 10, for example, a c-plane (0001), 0.25 ° off sapphire substrate or the like can be used. The n-type semiconductor layer 40, the active layer 42, and the p-type semiconductor layer 44 are each made of a group III nitride semiconductor, and the buffer layer 39, the n-type semiconductor layer 40, the block layer 41, the active layer 42, and the p-type are formed on the substrate 10. Semiconductor layers 44 are sequentially stacked.

  As shown in FIG. 11A, the p-type semiconductor layer 44 is disposed on the active layer 42, and includes a first nitride-based semiconductor layer 411 containing a p-type impurity and the first nitride-based semiconductor layer 411. Disposed on the second nitride semiconductor layer 412 containing a p-type impurity at a lower concentration than the p-type impurity of the first nitride semiconductor layer 411, and disposed on the second nitride semiconductor layer 412; A third nitride-based semiconductor layer 413 containing a p-type impurity having a higher concentration than the p-type impurity of the two-nitride-based semiconductor layer 412, and the third nitride-based semiconductor disposed on the third nitride-based semiconductor layer 413; And a fourth nitride semiconductor layer 414 containing a p-type impurity at a lower concentration than the p-type impurity of the layer 413.

  The thickness of the second nitride semiconductor layer 412 is formed to be greater than the thickness of the first nitride semiconductor layer 411 or the third nitride semiconductor layer 413 to the fourth nitride semiconductor layer 414.

  As shown in FIG. 11B, the active layer 42 includes a first well layer 321 to an nth well layer 32n sandwiched between a first barrier layer 311 to an nth barrier layer 31n and a final barrier layer 310, respectively. It is a quantum well (MQW) structure (n: natural number). That is, the active layer 42 has an n-pair structure in which a quantum well structure in which a well layer is sandwiched between barrier layers having a larger band gap than the well layer is a unit pair structure, and this unit pair structure is stacked n times.

  Specifically, the first well layer 321 is disposed between the first barrier layer 311 and the second barrier layer 312, and the second well layer 322 is disposed between the second barrier layer 312 and the third barrier layer 313. The The nth well layer 32n is disposed between the nth barrier layer 31n and the final barrier layer 310. The first barrier layer 311 of the active layer 42 is disposed on the n-type semiconductor layer 40 via the block layer 41, and the p-type semiconductor layer 44 (411 to 414) is disposed on the final barrier layer 310 of the active layer 42. Is done.

The well layers 321 to 32n are formed by, for example, In _x Ga _1-x N (0 <x <1) layers, and the barrier layers 311 to 31n and 310 are formed by, for example, GaN layers.

  FIG. 12A is a schematic cross-sectional structure diagram of another blue LED applicable to the semiconductor light-emitting device according to the first embodiment of the present invention, and a schematic cross-sectional structure diagram of the semiconductor light-emitting element portion, FIG. 12 (b) shows an enlarged schematic sectional view of the active layer portion.

  Another blue LED applicable to the semiconductor light emitting device according to the first embodiment of the present invention includes a substrate 10 and a buffer layer 39 disposed on the substrate 10 as shown in FIG. An n-type semiconductor layer 40 disposed on the buffer layer 39 and doped with an n-type impurity, and an n-type impurity disposed on the n-type semiconductor layer 40 and doped at a lower concentration than the n-type semiconductor layer 40 A block layer 41, an active layer 42 disposed on the block layer 41, a p-type semiconductor layer 44 disposed on the active layer 42, and an oxide electrode 45 disposed on the p-type semiconductor layer 44 are provided. .

  Another blue LED applicable to the semiconductor light emitting devices according to the first and second embodiments of the present invention includes a p-type impurity disposed on the active layer 42 as shown in FIG. A third nitride-based semiconductor layer 413 including the fourth nitride including a p-type impurity disposed on the third nitride-based semiconductor layer 413 and having a lower concentration than the p-type impurity of the third nitride-based semiconductor layer 413. And a transparent electrode formed on the fourth nitride semiconductor layer 414 and made of an oxide electrode 45.

  The blue LED applicable to the semiconductor light emitting device according to the first embodiment of the present invention includes an n-side electrode 510 for applying a voltage to the n-type semiconductor layer 40 and a p-type semiconductor layer 44 as shown in FIG. Further, a p-side electrode 110 for applying a voltage is provided. As shown in FIG. 13, the p-type semiconductor layer 44, the active layer 42, the block layer 41, and a partial region of the n-type semiconductor layer 40 are exposed on the n-type semiconductor layer 40 by mesa etching. An electrode 510 is disposed.

  The p-side electrode 110 is disposed on the p-type semiconductor layer 44 via the oxide electrode 45. Alternatively, the p-side electrode 110 may be disposed directly on the p-type semiconductor layer 44. The transparent electrode composed of the oxide electrode 45 disposed on the fourth nitride-based semiconductor layer 414 includes, for example, any of ZnO, ITO, or ZnO containing indium.

  The n-side electrode 510 is, for example, an aluminum (Al) film, a multilayer film of Ti / Ni / Au or Al / Ti / Au, Al / Ni / Au, Al / Ti / Ni / Au, or Au—Sn / Ti from the upper layer. The p-side electrode 110 is made of, for example, an Al film, palladium (Pd) -gold (Au) alloy film, Ni / Ti / Au multilayer film, or Au—Sn / It consists of a multilayer film of Ti / Au. The n-side electrode 510 is ohmically connected to the n-type semiconductor layer 40, and the p-side electrode 110 is ohmically connected to the p-type semiconductor layer 44 through the oxide electrode 45.

  FIG. 14 shows the surface of the p-side electrode 110 and the surface of the n-side electrode 330 for mounting the blue LED applicable to the semiconductor light emitting device according to the first embodiment of the present invention in a flip chip structure. It is formed so that the height measured from 10 becomes the same height. Similarly to the n-side electrode 510, the n-side electrode 330 is made of, for example, an aluminum (Al) film, a Ti / Ni / Au multilayer film, or a multilayer film of Au—Sn / Ti / Au / Ni / Al from the upper layer.

The structure shown in FIG. 14 includes a structure in which a transparent conductive film ZnO is formed as the oxide electrode 45 and this ZnO is covered with a reflective laminated film 58 that reflects the wavelength λ of the emitted light. The reflective laminated film 58 has a laminated structure of λ / 4n ₁ and λ / 4n ₂ (n ₁ and n ₂ are the refractive indexes of the laminated layers). As a material used for the laminated structure, for example, a laminated structure made of ZrO ₂ (n = 2.12) and SiO ₂ (n = 1.46) can be used for blue light with λ = 450 nm. In this case, the thickness of each layer is, for example, about 53 nm for ZrO ₂ and about 77 nm for SiO ₂ . As another material for forming the laminated structure, TiO ₂ , Al ₂ O ₃ or the like can be used.

  According to the blue LED shown in FIG. 14, the light emitted in the active layer 42 by the reflective laminated film 58 can be taken out from the substrate 10 side without being absorbed by the p-side electrode 110. Efficiency can be improved.

  The semiconductor light emitting device according to the first embodiment of the present invention has a size of 200 μm × 300 μm. The multicolor light emitting semiconductor light emitting device having such a fine pattern enables multicolor light emission such as red, yellow green, blue two color light emission, and three color light emission.

  Even if the red, yellow-green, and blue elements are individually formed small, the size of the entire package is not reduced by the package base on which the elements are mounted. However, by using the semiconductor light emitting device according to the first embodiment of the present invention, a package of, for example, about 1.5 mm × 1.3 mm square is reduced to, for example, about 1.0 mm × 1.0 mm square. It became possible.

In the semiconductor light-emitting device according to the first embodiment of the present invention, the active layer of the first semiconductor light-emitting element 12 is made of, for example, an In _x Ga _1-x N (0 <x <1) / GaN MQW structure. And forming the active layer of the second semiconductor light emitting element 16 with (Al _x Ga _y ) _0.5 In _0.5 P (0 ≦ x ≦ 0.85, 0 ≦ y ≦ 1) quaternary compound semiconductor. The blue LED and the red or yellow-green LED can be mounted by a pasting technique.

For example, the active layer of the second semiconductor light emitting element 16 includes (Al _x Ga _1-x ) _0.5 In _0.5 P well layer and (Al _y Ga _1-y ) _0.5 In _0.5 P barrier layer (0 ≦ x <y <1 ), A yellow-green LED or a red LED can be mounted by adjusting the composition ratio.

  By adjusting the composition ratio and the like, it is possible to obtain a two-color light emission, three-color light emission, and multicolor light emission semiconductor light-emitting device having a desired light emission wavelength peak in a wavelength range of about 450 nm to 700 nm.

(Plane pattern configuration example)
15 is a plan pattern configuration example of the semiconductor light emitting device according to the first embodiment of the present invention corresponding to FIG. 7, and FIG. 15A is a configuration diagram of the plane pattern example 1, and FIG. ) Is a configuration diagram of the planar pattern example 2, and FIG. 15C is a configuration diagram of the planar pattern example 3.

  In order to emit multiple color light emitting semiconductor light emitting devices separately or simultaneously, common cathode electrode and separate cathode electrode configuration and common anode electrode and separate cathode electrode pad configuration There is a common anode configuration. The semiconductor light emitting device according to the first embodiment of the present invention corresponding to FIG. 7 corresponds to the anode common configuration, as is apparent from the circuit configuration of FIG.

  When recognizing with a machine, since it recognizes with the reflectance of an electrode pad, it is necessary to change a shape or a reflectance. This machine recognition enables mass production.

  In pattern examples 1 to 3 of FIGS. 15A to 15C, the cathode electrode 50 is disposed on the GaP layer 24 of the red LED, the cathode electrode 46 is disposed on the n-type semiconductor layer 40 of the blue LED, A common anode electrode 48 is disposed on the p-type semiconductor layer 44 of the blue LED.

By changing the planar pattern shape of the p-type semiconductor layer 44 of the blue LED, it is possible to change the configuration as shown in pattern examples 1 to 3 in FIGS. In particular, in the planar pattern example 3 of FIG. 15C, the p-type semiconductor layer 44 of the blue LED is substantially the same as the shape of the substrate 10 and is not shown.

  According to the first embodiment of the present invention and the first and second modifications thereof, a semiconductor light-emitting device that is incorporated in a small package with a single chip, improves brightness by using a high-efficiency LED, and can emit multiple colors. Can be provided.

[Second Embodiment]
(Element structure)
As shown in FIG. 2A, the semiconductor light emitting device according to the second embodiment of the present invention includes a substrate 10, a first semiconductor light emitting element 12 arranged on the substrate 10, and a substrate 10. , A second semiconductor light emitting element 16 disposed adjacent to the first semiconductor light emitting element 12, a first pasted electrode 14a disposed on the first semiconductor light emitting element 12, and a second semiconductor light emitting element. Second pasted electrode 14c disposed on element 16, third pasted electrode 14b disposed on first pasted electrode 14a and second pasted electrode 14c, and third pasted A third semiconductor light emitting element 20 disposed on the electrode 14b. The substrate is transparent to the emission wavelength.

  Here, the substrate 10 can be made of, for example, sapphire or GaP.

  As shown in FIG. 2A, an electrode 6 disposed on the third semiconductor light emitting element 20 and a transparent electrode 8 disposed on the substrate 10 may be further provided.

  The pasted electrode 14a and the transparent electrode 8 constitute the anode or cathode electrode of the first semiconductor light emitting element 12, and the pasted electrode 14c and the transparent electrode 8 constitute the anode or cathode electrode of the second semiconductor light emitting element 16. To do. The pasted electrode 14 b and the electrode 6 constitute an anode or cathode electrode of the third semiconductor light emitting element 20.

  The pasted electrodes 14a, 14b, and 14c are common anode electrodes or cathode electrodes.

  In addition, the first semiconductor light emitting element 12, the second semiconductor light emitting element 16, and the third semiconductor light emitting element 20 may be semiconductor light emitting elements having an emission peak wavelength of one wavelength or two wavelengths.

  In the semiconductor light emitting device according to the second embodiment of the present invention, for example, a gallium nitride LED is applied as the first semiconductor light emitting element 12, and an InGaAlP LED is used as the second semiconductor light emitting element 16. By applying an InGaAlP-based LED as the third semiconductor light emitting element 20, and bonding them together with the bonding electrodes 14a, 14b, and 14c, an LED of three or more colors can be realized.

  Since the lower LED 1 and LED 2 are blocked by the pasted electrodes 14a or 14c, the light needs to be taken out from the lateral direction. Light can be extracted from the lateral direction.

  In addition, ZnO, ITO, etc. are applicable as a material of the transparent electrode 8 arrange | positioned on the board | substrate 10. FIG.

  In addition, it is also possible to take out the light of lower LED1 (for example, blue LED) or LED2 to the upper side by reducing the part of the bonding electrode 14a or 14c.

(Modification)
As shown in FIG. 2B, the semiconductor light emitting device according to the modification of the second embodiment of the present invention includes a substrate 10, a first semiconductor light emitting element 12 disposed on the substrate 10, A bonding electrode 14 disposed on one semiconductor light emitting element 12, a second semiconductor light emitting element 16 disposed on the bonding electrode 14, and a second semiconductor light emitting element 16 on the bonding electrode 14. And a third semiconductor light emitting element 20 arranged adjacent to each other. The substrate 10 is transparent with respect to the emission wavelength. Here, the substrate 10 can be made of, for example, sapphire or GaP.

  As shown in FIG. 2B, the first semiconductor light emitting device 12 is further provided with an electrode 18 disposed adjacent to the pasted electrode 14, and the second semiconductor light emitting device 16 is provided with the electrode 4. The electrode 6 may be provided on the third semiconductor light emitting element 20.

  The pasted electrode 14 and the electrode 18 constitute an anode or cathode electrode of the first semiconductor light emitting element 12, the electrode 4 and the pasted electrode 14 constitute an anode or cathode electrode of the second semiconductor light emitting element 16, The electrode 6 and the pasted electrode 14 constitute an anode or cathode electrode of the third semiconductor light emitting element 20. The pasted electrode 14 becomes a common anode electrode or a cathode electrode.

  In addition, the first semiconductor light emitting element 12, the second semiconductor light emitting element 16, and the third semiconductor light emitting element 20 may be semiconductor light emitting elements having an emission peak wavelength of one wavelength or two wavelengths.

  In the semiconductor light emitting device according to the modification of the second embodiment of the present invention, for example, a gallium nitride LED is applied as the first semiconductor light emitting element 12, and an InGaAlP system is used as the second semiconductor light emitting element 16. In this case, an InGaAlP-based LED is applied as the third semiconductor light-emitting element 20 and is bonded to each other with the bonding electrode 14 to realize an LED of three or more colors. Since the lower LED 1 is blocked by the portion of the pasted electrode 14 that is pasted, it is necessary to take out light from the lateral direction. Light can be extracted.

  Note that, similarly to FIG. 1B, a transparent electrode 8 disposed on the substrate 10 may be further provided. As a material of the transparent electrode 8, ZnO, ITO, or the like can be applied.

  In addition, it is also possible to take out the light of lower LED1 (for example, blue LED) to upper side by reducing the part of the bonding electrode 14. FIG.

(Specific configuration example)
Also in the semiconductor light emitting device according to the modification of the second embodiment of the present invention, the structural examples shown in FIGS. 9 to 14 can be applied to the specific structures of the first to third semiconductor light emitting elements. it can.

  The red LED shown in FIG. 9 can also be applied to the semiconductor light emitting device according to the second embodiment of the present invention.

  The yellow-green LED shown in FIG. 10 can also be applied to the semiconductor light emitting device according to the second embodiment of the present invention.

  The blue LED shown in FIGS. 11 to 14 can also be applied to the semiconductor light emitting device according to the second embodiment of the present invention.

Also in the semiconductor light-emitting device according to the second embodiment of the present invention, the active layer of the first semiconductor light-emitting element 12 has, for example, an In _x Ga _1-x N (0 <x <1) / GaN MQW structure. The active layer of the second semiconductor light emitting device 16 and the active layer of the third semiconductor light emitting device 16 are formed as (Al _x Ga _y ) _0.5 In _0.5 P (0 ≦ x ≦ 0.85, 0 ≦ y ≦ 1). ) By forming with a quaternary compound semiconductor, blue LEDs, red and yellow-green LEDs can be mounted by a bonding technique.

Also in the semiconductor light-emitting device according to the second embodiment of the present invention, the active layer of the first semiconductor light-emitting element 12 has, for example, an In _x Ga _1-x N (0 <x <1) / GaN MQW structure. The active layer of the second semiconductor light emitting device 16 is formed by, for example, (Al _x Ga _1-x ) _0.5 In _0.5 P well layer and (Al _y Ga _1-y ) _0.5 In _0.5 P barrier layer (0 ≦ x < The active layer of the third semiconductor light emitting device 20 is formed of an (Al _x Ga _{1 -x} ) _0.5 In _0.5 P well layer and an (Al _y Ga _{1 -y} ) _0.5 In _By forming the multi-quantum well structure of _0.5 P barrier layer (0 ≦ x <y <1), it is possible to mount both a blue LED, a yellow-green LED, and a red LED.

  By adjusting the composition ratio and the like, it is possible to obtain a two-color light emission, three-color light emission, and multicolor light emission semiconductor light-emitting device having a desired light emission wavelength peak in a wavelength range of about 450 nm to 700 nm.

  The semiconductor light emitting device according to the second embodiment of the present invention can be similarly configured by extending FIG. 15 of the planar pattern configuration of the semiconductor light emitting device according to the first embodiment.

  Also in the semiconductor light emitting device according to the second embodiment of the present invention, in the three semiconductor light emitting elements, the cathode electrode is shared, and the cathode common configuration in which the anode electrode pads are separately configured, and the anode electrode are shared. And an anode common configuration in which the cathode electrode pads are separately configured is possible. Alternatively, two of the three semiconductor light emitting elements can be used in a parallel configuration.

  According to the second embodiment of the present invention and its modification, there is provided a semiconductor light emitting device capable of emitting multicolor light by using a highly efficient LED that is incorporated into a small package with one chip. be able to.

[Other embodiments]
As described above, the present invention has been described with reference to the first to second embodiments and the respective modifications. However, it should be understood that the description and drawings constituting a part of this disclosure limit the present invention. is not. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  As the semiconductor light emitting device according to the first embodiment of the present invention, the LED has been mainly described as an example. However, a laser diode (LD) may be configured, and in that case, a distributed feedback type (DFB) : Distributed Feedback) LD, distributed Bragg reflection type (DBR) LD, surface emitting LD, etc. may be configured.

  In the description of the above-described embodiment, the active layer has an MQW structure having a plurality of well layers sandwiched between barrier layers. However, the active layer includes one well layer, and this well A structure in which the film thickness of the final barrier layer disposed between the p-type semiconductor layer and the p-type semiconductor layer is thicker than the Mg diffusion distance may be employed.

  As described above, the present invention naturally includes various embodiments that are not described herein. Accordingly, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The semiconductor light emitting device according to the embodiment of the present invention can be used for semiconductor light emitting devices in general in which a semiconductor light emitting element is incorporated in a small package such as a two-color or three-color package and incorporated in a mobile phone or the like.

(A) The semiconductor light emitting device according to the first embodiment of the present invention, in which a two-color light emitting semiconductor light emitting device is formed by a bonding technique, and (b) the first embodiment of the present invention. The semiconductor light-emitting device which concerns on the modification 1 of this embodiment, Comprising: The typical cross-section figure which formed the semiconductor light-emitting device of another 2 color light emission by the sticking technique, (c) 1st implementation of this invention FIG. 10 is a schematic cross-sectional structure diagram illustrating a semiconductor light emitting device according to a second modification of the embodiment in which another two-color light emitting semiconductor light emitting device is formed by a bonding technique. (A) A semiconductor light emitting device according to a second embodiment of the present invention, in which a three-color light emitting semiconductor light emitting device is formed by a bonding technique, (b) a second cross section of the present invention. FIG. 6 is a schematic cross-sectional structure diagram illustrating a semiconductor light emitting device according to a modification of the embodiment, in which another three-color light emitting semiconductor light emitting device is formed by a bonding technique. FIG. 3 is a schematic cross-sectional structure diagram illustrating a first semiconductor light emitting element applied to the semiconductor light emitting device according to the first embodiment of the present invention, in which a blue LED is formed on a sapphire substrate. FIG. 3 is a schematic cross-sectional structure diagram illustrating a second semiconductor light emitting element applied to the semiconductor light emitting device according to the first embodiment of the present invention, in which a red LED is formed on a GaAs substrate. FIG. 2 is a schematic diagram of a semiconductor light emitting device according to the first embodiment of the present invention, in which a two-color light emitting semiconductor light emitting device is formed by attaching a blue LED shown in FIG. 3 and a red LED shown in FIG. FIG. In FIG. 5, the expanded typical cross-section figure of the part connected by the sticking technique. BRIEF DESCRIPTION OF THE DRAWINGS It is a specific structural example of the semiconductor light-emitting device concerning the 1st Embodiment of this invention, Comprising: (a) Typical cross section which affixed blue LED and red LED and formed the semiconductor light emitting element of 2 color light emission FIG. 2 is a structural diagram, and FIG. FIG. 5 is another specific configuration example of the semiconductor light emitting device according to the first embodiment of the present invention, in which a blue LED and a red LED are attached to form a two-color light emitting semiconductor light emitting element. Figure. The typical cross-section figure of red LED applicable to the semiconductor light-emitting device which concerns on the 1st thru | or 2nd embodiment of this invention. The typical cross-section figure of yellowish green LED applicable to the semiconductor light-emitting device concerning the 1st thru | or 2nd embodiment of this invention. FIG. 2 is a schematic cross-sectional structure diagram of a blue LED applicable to the semiconductor light-emitting devices according to the first and second embodiments of the present invention, wherein (a) a schematic cross-sectional structure diagram of a semiconductor light-emitting element portion; FIG. 2 is an enlarged schematic sectional view of an active layer portion. FIG. 2 is a schematic cross-sectional structure diagram of another blue LED applicable to the semiconductor light-emitting device according to the first to second embodiments of the present invention, and (a) a schematic cross-sectional structure diagram of a semiconductor light-emitting element portion; FIG. 2 is an enlarged schematic cross-sectional structure diagram of an active layer portion. The typical cross-section figure formed to the p side electrode and n side electrode of blue LED applicable to the semiconductor light-emitting device which concerns on the 1st thru | or 2nd embodiment of this invention. The typical cross-section figure after the last electrode formation process in blue LED applicable to the semiconductor light-emitting device which concerns on the 1st thru | or 2nd embodiment of this invention. FIG. 8 is a plan pattern configuration example of the semiconductor light emitting device according to the first embodiment of the present invention corresponding to FIG. 7, and (a) a configuration diagram of the plane pattern example 1; (C) The block diagram of plane pattern example 3. FIG. It is typical sectional structure drawing of the semiconductor light emitting element concerning a prior art example, Comprising: (a) The example which creates an active layer from which light emission wavelength differs by performing epitaxial growth twice, (b) Example of creating active layers with different emission wavelengths by epitaxial growth.

Explanation of symbols

2, 4, 6, 18 ... electrodes 8, 38 ... transparent electrode 10 ... substrate 12 ... first semiconductor light emitting element (LED1)
14, 14a, 14b, 14c, 34 ... pasted electrode 16 ... second semiconductor light emitting element (LED2)
20 ... Third semiconductor light emitting element (LED3)
22, 100 ... GaAs substrate 24, 32 ... GaP layers 26, 160, 170 ... n-type cladding layers 28, 42, 180, 190 ... active layers 30, 200, 210 ... p-type cladding layer 36 ... reflection layer 39 ... buffer layer 40 ... n-type semiconductor layer 41 ... block layer 44 ... p-type semiconductor layer 45 ... oxide electrode 46, 50 ... cathode electrode 48 ... anode electrode 58 ... reflective laminated film 100 ... GaAs substrate 110 ... p-side electrode 120 ... GsAs buffer layer 140, 150 ... reflective laminated film (DBR)
220, 230 ... InGaAlP layer 240, 250 ... GaP window layer 260, 270 ... AlGaInP layer 280, 290 ... GaAs layer (etching stop layer)
300 ... first epitaxial growth layer 310 ... final barrier layers 311 to 31n ... barrier layer 320 ... second epitaxial growth layers 321 to 32n ... well layers 330, 510 ... n-side electrode 411 ... first nitride semiconductor layer 412 ... first 2 nitride semiconductor layer 413... 3rd nitride semiconductor layer 414... 4th nitride semiconductor layer

Claims (10)

A substrate,
A first semiconductor light emitting device disposed on the substrate;
An affixing electrode disposed on the first semiconductor light emitting element;
And a second semiconductor light emitting element disposed on the affixed electrode, wherein the substrate is transparent to the emission wavelength.   The semiconductor light emitting device according to claim 1, further comprising an electrode disposed adjacent to the pasted electrode on the first semiconductor light emitting element.   The semiconductor light-emitting device according to claim 1, further comprising a transparent electrode disposed on the substrate.   2. The semiconductor light emitting device according to claim 1, wherein each of the first semiconductor light emitting element and the second semiconductor light emitting element is a semiconductor light emitting element having an emission peak wavelength of one wavelength or two wavelengths. A substrate,
A first semiconductor light emitting device disposed on the substrate;
An affixing electrode disposed on the substrate adjacent to the first semiconductor light emitting element;
A semiconductor light emitting device comprising: a second semiconductor light emitting element disposed on the pasted electrode.   6. The semiconductor light emitting device according to claim 5, wherein the first semiconductor light emitting element and the second semiconductor light emitting element are semiconductor light emitting elements having an emission peak wavelength of one wavelength or two wavelengths. A substrate,
A first semiconductor light emitting device disposed on the substrate;
A second semiconductor light emitting element disposed adjacent to the first semiconductor light emitting element on the substrate;
A first pasted electrode disposed on the first semiconductor light emitting element;
A second pasted electrode disposed on the second semiconductor light emitting element;
A third pasted electrode disposed on the first and second pasted electrodes;
And a third semiconductor light emitting element disposed on the third bonding electrode, wherein the substrate is transparent to the emission wavelength.   The semiconductor light emitting device according to claim 7, further comprising a transparent electrode disposed on the substrate. A substrate,
A first semiconductor light emitting device disposed on the substrate;
An affixing electrode disposed on the first semiconductor light emitting element;
A second semiconductor light emitting element disposed on the pasted electrode;
A semiconductor light emitting device comprising: a third semiconductor light emitting element disposed adjacent to the second semiconductor light emitting element on the pasted electrode; and the substrate is transparent to an emission wavelength. .   The semiconductor light emitting device according to claim 9, further comprising an electrode disposed adjacent to the pasted electrode on the first semiconductor light emitting element.

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