JP5454303B2 - Semiconductor light emitting device array - Google Patents

Description

The present invention relates to semi-conductor light emitting element array you emit light in the stacking direction.

  Conventionally, in a GaN-based semiconductor light emitting device, a phosphor material is generally provided outside the semiconductor light emitting device as a method for converting the wavelength of light output from the semiconductor light emitting device.

  In a technical field different from the above, examples in which the excitation light source and the light emitting part are separated from each other, such as phosphor film excitation light emission by ultraviolet rays and phosphor film excitation light emission by electron beams, are well known (Patent Literature). 1-3).

Japanese Patent No. 3724490 Japanese Patent No. 3736357 Japanese Patent No. 3609365

  By the way, when providing a phosphor material outside the semiconductor light emitting device, a process different from the process for manufacturing the semiconductor light emitting device is required. Therefore, there has been a problem that the development and manufacturing costs increase. In addition, the phosphor material has a small Stoke shift, and it is not easy to select the color of the material itself. Furthermore, the emission spectrum after conversion becomes significantly broader than the excitation-side spectrum of the current phosphor material.

  As another method of wavelength conversion, it has been considered to form an electron excitation type light emitting element by mixing rare earth elements and the like. A light-emitting element according to this method is advantageous for wavelength selection because red can be selected as the emission wavelength after conversion. However, this method for manufacturing a light-emitting element is extremely difficult and has low practicality.

  Thus, conventionally, it is not easy to increase the Stoke shift, and it is difficult to provide the wavelength conversion structure in the chip by a simple method.

The present invention has been made in view of the above problems, its object is to provide a semi-conductor light emitting element array capable of providing in a chip of large wavelength converting structure of the Stokes shift in a simple manner.

The first and second semiconductor light emitting element arrays of the present invention include a first conductive type semiconductor layer, an active layer, a second conductive type semiconductor layer, and a chromaticity conversion layer in this order, and emit light emitted from the active layer. A semiconductor layer having a plurality of mesa portions to be output to the outside through a chromaticity conversion layer is provided. The first and second semiconductor light emitting element arrays further include electrodes arranged at positions where current can be injected into the active layer without going through the chromaticity conversion layer.
The first semiconductor light emitting element array of the present invention further includes the following components (A1) to (A3).
(A1) The chromaticity conversion layer included in the first mesa portion among the plurality of mesa portions absorbs light emitted from the active layer and emits light having a wavelength in the first wavelength band. have.
(A2) The chromaticity conversion layer included in the second mesa portion among the plurality of mesa portions absorbs the light emitted from the first multilayer structure and the first multilayer structure, and from the first wavelength band And a second multilayer structure that emits light having a long wavelength.
(A3) The chromaticity conversion layer included in the third mesa portion among the plurality of mesa portions absorbs light emitted from the first multilayer structure, the second multilayer structure, and the second multilayer structure. And a third multilayer structure that emits light having a wavelength longer than that of the second wavelength band.
The second semiconductor light emitting element array of the present invention further includes the following components (B1) to (B5).
(B1) A chromaticity conversion layer included in the first mesa portion among the plurality of mesa portions absorbs light emitted from the active layer and emits light having a wavelength in the first wavelength band. have.
(B2) The chromaticity conversion layer included in the second mesa portion among the plurality of mesa portions absorbs the light emitted from the active layer, and emits light having a wavelength longer than the first wavelength band. It has a multilayer structure.
(B3) The chromaticity conversion layer included in the third mesa portion among the plurality of mesa portions absorbs light emitted from the active layer, and emits light having a wavelength longer than that of the second wavelength band. It has a multilayer structure.
(B4) The semiconductor layer has a semiconductor substrate between the second conductivity type semiconductor layer and the chromaticity conversion layer.
(B5) The chromaticity conversion layer is formed by crystal growth on a semiconductor substrate.

In the first and second semiconductor light emitting element arrays of the present invention, a chromaticity conversion layer is provided in the semiconductor layer. Thereby, the chromaticity conversion layer can be provided in the semiconductor layer using the same manufacturing method as that for the active layer. Further, in the present invention, the chromaticity conversion layer is provided in a portion of the semiconductor layer that is different from the current path injected by the electrode. Thereby, a chromaticity conversion layer can be provided in the semiconductor layer without changing the driving conditions. In addition, since the composition ratio and the laminated structure of the chromaticity conversion layer can be freely changed, the stalk shift amount can be freely changed only by appropriately changing them.

According to the first and second semiconductor light emitting element arrays of the present invention, the chromaticity conversion layer is provided in the semiconductor layer, and the chromaticity conversion layer is formed in the semiconductor layer using the same manufacturing method as that of the first conductivity type semiconductor layer. Can be provided. In addition, the stalk shift amount can be freely changed simply by appropriately changing the composition ratio and the laminated structure of the chromaticity conversion layer. Thereby, a wavelength conversion structure (chromaticity conversion layer) having a large Stoke shift can be provided in the chip by a simple method.

1 is a perspective view of a surface emitting semiconductor light emitting element according to a first embodiment of the present invention. It is sectional drawing of the AA arrow direction of the semiconductor light-emitting device of FIG. It is sectional drawing showing an example of the chromaticity conversion layer of FIG. It is sectional drawing showing the other example of the chromaticity conversion layer of FIG. FIG. 6 is a cross-sectional view illustrating a modification of the semiconductor light emitting element of FIG. 2. It is a perspective view of the surface emitting semiconductor light emitting element array which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the AA arrow direction of the semiconductor light-emitting element array of FIG. FIG. 8 is a cross-sectional view illustrating a first modification of the semiconductor light emitting element array in FIG. 7. It is sectional drawing showing the 2nd modification of the semiconductor light-emitting element array of FIG. It is sectional drawing showing the 3rd modification of the semiconductor light-emitting element array of FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. The description will be given in the following order.

1. 1st Embodiment (FIGS. 1-4)
An example in which the chromaticity conversion layer is provided on the upper surface of the mesa portion. Modification of the first embodiment (FIG. 5)
An example in which the chromaticity conversion layer is provided on the back surface of the substrate. Second embodiment (FIGS. 6 and 7)
○ Example in which multiple mesa parts are provided Modified example of the second embodiment (FIGS. 8 to 10)
○ Variation of internal structure and arrangement of chromaticity conversion layer

<First Embodiment>
FIG. 1 is a perspective view of a surface-emitting type semiconductor light emitting device 1 according to a first embodiment of the present invention. FIG. 2 illustrates an example of a cross-sectional configuration of the semiconductor light emitting device 1 in FIG. 3 and 4 show an example of an internal configuration of a chromaticity conversion layer 15 described later. 1 to 4 are schematically shown and are different from actual dimensions and shapes.

  The semiconductor light emitting element 1 of the present embodiment is configured to include, for example, an LED (Light Emitting Diode). The semiconductor light emitting device 1 includes, for example, a semiconductor layer 20 formed by laminating a lower clad layer 11, an active layer 12, an upper clad layer 13, a contact layer 14 and a chromaticity conversion layer 15 in this order on one surface side of a substrate 10. ing. A columnar mesa portion 16 is formed on the semiconductor layer 20, specifically, a part (upper portion) of the lower cladding layer 11, the active layer 12, the upper cladding layer 13, the contact layer 14, and the chromaticity conversion layer 15. Has been. The mesa unit 16 outputs light emitted from the active layer 12 to the outside via the chromaticity conversion layer 15.

  In the present embodiment, the lower clad layer 11 corresponds to a specific example of “first conductivity type semiconductor layer” of the present invention. The upper cladding layer 13 corresponds to a specific example of a “second conductivity type semiconductor layer” of the present invention. The substrate 10 and the semiconductor layer 20 correspond to a specific example of “semiconductor layer” of the present invention.

  The substrate 10 is made of a group III-V nitride semiconductor such as GaN, for example. The substrate 10 may be a substrate other than a GaN substrate, such as a sapphire substrate, a SiC substrate, or a Si substrate. Here, the “III-V nitride semiconductor” means at least one of the group 3B elements in the short period periodic table, and at least N of the group 5B elements in the short period periodic table. Points to things that contain Examples of the group III-V nitride semiconductor include a gallium nitride compound containing Ga and N. Examples of the gallium nitride compound include GaN, AlGaN, InGaN, AlInGaN, and the like. For group III-V nitride semiconductors, an n-type impurity of a group IV or VI element such as Si, Ge, O, or Se, or a group II or group IV element such as Mg, Zn, or C, if necessary. A p-type impurity is doped.

  Each layer in the semiconductor layer 20 (mesa portion 16) is composed of the same material system, specifically, a group III-V nitride semiconductor. The semiconductor layer 20 has a wurtzite crystal structure. The growth plane orientation of the semiconductor layer 20 is the (0001) direction, and the crystal plane orientations of the layers in the semiconductor layer 20 are all the same direction. The semiconductor layer 20 (mesa portion 16) is formed by crystal growth on the substrate 10, and the layers in the semiconductor layer 20 are formed in a lump together. That is, the chromaticity conversion layer 15 is formed together with the other layers in the semiconductor layer 20.

  The lower cladding layer 11 is made of, for example, n-type AlGaN. The active layer 12 is made of, for example, undoped GaInN. The active layer 12 has, for example, a band gap corresponding to a wavelength band of light in the ultraviolet region (ultraviolet light), and emits ultraviolet light by current injection. The upper cladding layer 13 is made of, for example, p-type AlGaN. The contact layer 14 is made of, for example, p-type AlGaN.

  The chromaticity conversion layer 15 is formed in a portion of the semiconductor layer 20 that is different from a current path injected by a lower electrode 35 and an upper electrode 31 described later. For this reason, the chromaticity conversion layer 15 does not affect the driving conditions of the semiconductor light emitting element 1, but only affects the light emitted from the active layer 12. The chromaticity conversion layer 15 has a multilayer structure that absorbs light emitted from the active layer 12 and emits light having a wavelength different from the wavelength of the absorbed light. For example, as shown in FIG. 3A, the chromaticity conversion layer 15 has a multilayer structure 15a that absorbs ultraviolet light emitted from the active layer 12 and emits light in the red wavelength band. Further, for example, as shown in FIG. 3B, the chromaticity conversion layer 15 has a multilayer structure 15b that absorbs ultraviolet light emitted from the active layer 12 and emits light in the green wavelength band. Yes. The chromaticity conversion layer 15 has a multilayer structure 15c that absorbs ultraviolet light emitted from the active layer 12 and emits light in a blue wavelength band, for example, as shown in FIG. Yes.

  Each of the multilayer structure 15a, the multilayer structure 15b, and the multilayer structure 15c has a multiple quantum well structure in which, for example, well layers and barrier layers formed of GaInN having different composition ratios are alternately stacked. The In composition ratios included in the multilayer structure 15a, the multilayer structure 15b, and the multilayer structure 15c are different from each other. The In composition ratio included in the multilayer structure 15a is, for example, about 30 to 35%, and the In composition ratio included in the multilayer structure 15b is, for example, about 25%, and is included in the multilayer structure 15c. The In composition ratio is about 15%, for example. That is, the wavelength of light emitted from the multilayer structure 15a, the multilayer structure 15b, and the multilayer structure 15c is defined only by the difference in the In composition ratio. Even if the wavelength of light emitted from the multilayer structure 15a, the multilayer structure 15b, and the multilayer structure 15c is adjusted by adjusting not only the In composition ratio but also the thickness and combination of each layer included in the multilayer structure. Good.

  In this specification, when the chromaticity conversion layer 15 outputs red light to the outside, the chromaticity conversion layer 15 is referred to as a redness conversion layer 15R. In addition, when the chromaticity conversion layer 15 outputs green light to the outside, the chromaticity conversion layer 15 is referred to as a greenness conversion layer 15G. When the chromaticity conversion layer 15 outputs blue light to the outside, the chromaticity conversion layer 15 is referred to as a blueness conversion layer 15B.

  The chromaticity conversion layer 15 may consist of only a single multilayer structure as shown in FIG. 3, but includes a plurality of multilayer structures as shown in FIGS. 4 (A) and 4 (B), for example. It may be comprised. For example, as shown in FIG. 4A, the chromaticity conversion layer 15 (redness conversion layer 15R) is formed by laminating a multilayer structure 15c, a multilayer structure 15b, and a multilayer structure 15a in this order from the upper cladding layer 13 side. Has been. Further, the chromaticity conversion layer 15 (greenness conversion layer 15G) is configured by, for example, laminating a multilayer structure 15c and a multilayer structure 15b in order from the upper cladding layer 13 side, as shown in FIG. 4B. Yes.

  On the upper surface of the mesa portion 16 (outer edge of the contact layer 14), an annular upper electrode 31 having an opening at least in a region facing the central region of the upper surface of the mesa portion 16 is formed. The upper electrode 31 is electrically connected to the contact layer 14 and is disposed at a position where current can be injected into the active layer 12 without using the chromaticity conversion layer 15. An insulating layer 32 is formed on the side surface and the peripheral surface of the mesa portion 16. On the surface of the insulating layer 32 corresponding to the periphery of the mesa portion 16, electrode pads 33 and 36 for bonding wires (not shown) and connection portions 34 and 37 are provided. Further, an opening 32A in which a part of the lower cladding layer 11 is exposed is provided at the base of the mesa portion 16 in the insulating layer 32, and a C-type is formed on the surface of the lower cladding layer 11 exposed in the opening 32A. The lower electrode 35 is provided. The lower electrode 35 is electrically connected to the lower cladding layer 11. The electrode pad 33 is electrically connected to the upper electrode 31 through the connection portion 34. The electrode pad 36 is electrically connected to the lower electrode 35 via the connection portion 37.

  Here, the insulating layer 32 is made of an insulating material such as oxide or nitride. The upper electrode 31, the electrode pads 33 and 36, and the connection portions 34 and 37 are configured by, for example, sequentially stacking Ti, Pt, and Au from the contact layer 14 side. The lower electrode 35 has, for example, a structure in which an alloy of Au and Ge, Ni, and Au are sequentially stacked from the lower cladding layer 11 side.

[Production method]
The semiconductor light emitting device 1 of the present embodiment can be manufactured as follows, for example.

Here, the compound semiconductor layer on the substrate 10 made of GaN is formed by, for example, MOCVD (Metal Organic Chemical Vapor Deposition). At this time, for example, trimethylaluminum (TMA), trimethylgallium (TMG), trimethylindium (TMIn), and ammonia (NH3) are used as the raw material for the III-V group nitride semiconductor. , H ₂ Se, and dimethyl zinc (DMZ), for example, is used as the acceptor impurity material.

  Specifically, first, the lower clad layer 11, the active layer 12, the upper clad layer 13, the contact layer 14, and the chromaticity conversion layer 15 are laminated on the substrate 10 in this order. Next, a circular resist layer is formed on the surface of the chromaticity conversion layer 15. Subsequently, the chromaticity conversion layer 15 is selectively removed by, for example, reactive ion etching (RIE) method using the resist layer as a mask. As a result, a circular chromaticity conversion layer 15 is formed on the contact layer 14. Thereafter, the resist layer is removed.

  Next, a circular resist layer is formed on the surface of the contact layer 14 including the chromaticity conversion layer 15 so as to cover the chromaticity conversion layer 15. Subsequently, the contact layer 14 to the upper part of the lower cladding layer 11 are selectively removed by, for example, RIE, using the resist layer as a mask. As a result, a columnar mesa portion 16 extending from the upper portion of the lower cladding layer 11 to the chromaticity conversion layer 15 is formed immediately below the circular resist layer. Thereafter, the resist layer is removed.

Next, an insulating layer 32 made of an insulating inorganic material such as silicon oxide (SiO ₂ ) is formed on the entire surface. Subsequently, a resist layer (not shown) having an annular opening on the upper surface of the mesa portion 16 (upper surface of the contact layer 14) and a C-shaped opening at the base of the mesa portion 16 is formed on the entire surface. Thereafter, the insulating layer 32 is selectively removed by, for example, RIE using the resist layer as a mask. Thereby, an opening (not shown) is formed in a portion where the upper electrode 31 is formed and a portion where the lower electrode 35 is formed. Thereafter, the resist layer is removed.

  Next, the above-mentioned metal material is laminated on the entire surface by, for example, vacuum deposition. Thereafter, for example, by selective etching, the annular upper electrode 31 and the C-shaped lower electrode 35 are formed so as to fill the opening of the insulating layer 32, and the electrode is formed on the surface of the insulating layer 32 corresponding to the periphery of the mesa portion 17. Pads 33 and 36 are formed. Further, a connection portion 34 is formed between the electrode pad 33 and the upper electrode 31, and a connection portion 37 is formed between the electrode pad 36 and the lower electrode 35. In this way, the semiconductor light emitting device 1 of the present embodiment is manufactured.

  Next, the operation and effect of the semiconductor light emitting device 1 of the present embodiment will be described.

[Action / Effect]
In the semiconductor light emitting device 1 of the present embodiment, when a predetermined voltage is applied between the lower electrode 35 and the upper electrode 31, a current is injected into the active layer 12 through the current injection region 19A in the current confinement layer 19, This causes light emission due to recombination of electrons and holes. The light generated in the active layer 12 is output from the upper surface of the mesa unit 17 to the outside.

  In the present embodiment, the chromaticity conversion layer 15 is formed in a portion of the semiconductor layer 20 that is different from the current path injected by the lower electrode 35 and the upper electrode 31. Therefore, no current flows through the chromaticity conversion layer 15, and the chromaticity conversion layer 15 has no influence on the driving conditions of the semiconductor light emitting element 1. Therefore, the composition ratio and the laminated structure of the chromaticity conversion layer 15 are not limited by the driving conditions of the semiconductor light emitting device 1.

  In the present embodiment, the chromaticity conversion layer 15 is provided in the semiconductor layer 20. Thereby, the chromaticity conversion layer 15 can be provided in the semiconductor layer 20 using the same manufacturing method as that for the active layer 12 and the like. Further, since the composition ratio and the laminated structure of the chromaticity conversion layer 15 can be freely changed as described above, the stalk shift amount can be freely changed by changing them appropriately. Therefore, the wavelength conversion structure (chromaticity conversion layer 15) having a large Stoke shift can be provided in the chip (in the semiconductor layer 20) by a simple method.

<Modification of the first embodiment>
In the above embodiment, the chromaticity conversion layer 15 is provided on the upper surface of the mesa unit 16, but may be formed on the back surface of the substrate 10 as shown in FIG. 5, for example. In this case, the chromaticity conversion layer 15 is formed by crystal growth on the substrate 10, and the light emission surface 15 </ b> A of the semiconductor light emitting element 1 is the back side of the substrate 10. At this time, the contact layer 14 is exposed on the upper surface of the mesa unit 16. For example, as shown in FIG. 5, the upper electrode 31 may be formed on the entire upper surface of the mesa unit 16. In this modification, the chromaticity conversion layer 15, the substrate 10, and the semiconductor layer 20 correspond to a specific example of the “semiconductor layer” of the present invention.

<Second Embodiment>
Next, a surface emitting semiconductor light emitting element array 2 according to a second embodiment of the present invention will be described. FIG. 6 is a perspective view of the semiconductor light emitting element array 2. 7 and 8 illustrate an example of a cross-sectional configuration of the semiconductor light emitting element array 2 in FIG. 6 to 8 are schematically shown and are different from actual dimensions and shapes.

  The semiconductor light emitting element array 2 of the present embodiment has a plurality of semiconductor light emitting elements 1 formed on one chip. Therefore, in the following, description of points in common with the above embodiment will be omitted as appropriate, and feature points of this embodiment will be described in detail. In addition, the lower electrode 35 of each semiconductor light emitting element 1 may be made common as shown in FIG. 6, or may be formed separately from each other although not shown.

  The semiconductor light emitting element array 2 includes a plurality of mesa portions 16 on one surface side of the substrate 10. Each layer in each mesa portion 16 is composed of the same material system, and specifically is composed of a group III-V nitride semiconductor. Each mesa portion 16 is formed by crystal growth on the substrate 10, and each layer in the semiconductor layer 20 (each mesa portion 16) is formed in a lump. That is, the chromaticity conversion layer 15 is formed together with the other layers in the semiconductor layer 20. Each mesa unit 16 outputs light emitted from the active layer 12 to the outside via the chromaticity conversion layer 15. Here, as illustrated in FIG. 6, the chromaticity conversion layer 15 included in one mesa unit 16 (first mesa unit) among the plurality of mesa units 16 is a redness conversion layer 15R. In addition, the chromaticity conversion layer 15 included in another mesa unit 16 (second mesa unit) among the plurality of mesa units 16 is a greenness conversion layer 15G, and among the plurality of mesa units 16 The chromaticity conversion layer 15 included in the other mesa unit 16 (third mesa unit) is a blueness conversion layer 15G.

  Here, for example, as shown in FIG. 7, the redness conversion layer 15 </ b> R has a multilayer structure 15 a that absorbs ultraviolet light emitted from the active layer 12 and emits light in the red wavelength band. Further, as shown in FIG. 7, for example, the green degree conversion layer 15G has a multilayer structure 15b that absorbs ultraviolet light emitted from the active layer 12 and emits light in the green wavelength band. In addition, the blue degree conversion layer 15B has a multilayer structure 15c that absorbs ultraviolet light emitted from the active layer 12 and emits light in a blue wavelength band, for example, as shown in FIG. The multilayer structure 15a, the multilayer structure 15b, and the multilayer structure 15c have, for example, a multiple quantum well structure in which well layers and barrier layers respectively formed of GaInN having different composition ratios are alternately stacked. The In composition ratios included in the multilayer structure 15a, the multilayer structure 15b, and the multilayer structure 15c are different from each other. The In composition ratios included in the multilayer structure 15a, the multilayer structure 15b, and the multilayer structure 15c are the same as the values described in the first embodiment.

  Note that the redness conversion layer 15R and the greenness conversion layer 15G may have only a single multilayer structure as shown in FIG. 7, for example, a plurality of multilayer structures as shown in FIG. It may be configured to include. For example, as illustrated in FIG. 8, the redness conversion layer 15 </ b> R may be configured by sequentially laminating a multilayer structure 15 c, a multilayer structure 15 b, and a multilayer structure 15 a from the upper cladding layer 13 side. At this time, the multilayer structure 15b absorbs light emitted from the active layer 12 and the multilayer structure 15c, and emits light in the green wavelength band. The multilayer structure 15a absorbs light emitted from the active layer 12, the multilayer structure 15c, and the multilayer structure 15b, and emits light in the red wavelength band. Further, for example, as shown in FIG. 8, the green degree conversion layer 15G may be configured by laminating a multilayer structure 15c and a multilayer structure 15b in order from the upper clad layer 13 side. At this time, the multilayer structure 15b absorbs light emitted from the active layer 12 and the multilayer structure 15c, and emits light in the green wavelength band.

[Production method]
Next, an example of a method for manufacturing the semiconductor light emitting element array 2 of the present embodiment will be described. The semiconductor light emitting element array 2 can be basically manufactured by a method similar to the method for manufacturing the semiconductor light emitting element 1. However, when the redness conversion layer 15R and the greenness conversion layer 15G are configured to include a plurality of multilayer structures as shown in FIG. 8, for example, the following method is preferably used.

  Specifically, first, the lower clad layer 11, the active layer 12, the upper clad layer 13, the contact layer 14, and the chromaticity conversion layer 15 are laminated on the substrate 10 in this order. Further, as the chromaticity conversion layer 15, a multilayer structure 15 c, a multilayer structure 15 b, and a multilayer structure 15 a that are stacked in order from the upper cladding layer 13 side are formed on the upper cladding layer 13.

  Next, in the chromaticity conversion layer 15, the surface including the region where the redness conversion layer 15R is to be formed is covered, and the region where the greenness conversion layer 15G and the blueness conversion layer 15B are to be formed is included. A resist layer having an opening on the surface is formed. Subsequently, the multilayer structure 15a in the chromaticity conversion layer 15 is selectively removed by the RIE method, for example, using the resist layer as a mask. Thereafter, the resist layer is removed.

  Subsequently, the chromaticity conversion layer 15 covers a surface including a region where the redness conversion layer 15R and the greenness conversion layer 15G are formed, and includes a region where the blueness conversion layer 15B is formed. A resist layer having an opening on the surface is formed. Subsequently, for example, by the RIE method, the multilayer structure 15b in the chromaticity conversion layer 15 is selectively removed using the resist layer as a mask. Thereafter, the resist layer is removed.

  Further, a plurality of circular resist layers having an area smaller than the upper surface of the mesa portion 16 are formed in a region where the mesa portion 16 is to be formed in the chromaticity conversion layer 15. Subsequently, the chromaticity conversion layer 15 is selectively removed by the RIE method using the resist layer as a mask. Thereafter, the resist layer is removed. Thereby, the redness conversion layer 15R in which the multilayer structure 15c, the multilayer structure 15b, and the multilayer structure 15a are sequentially laminated from the upper clad layer 13 side is formed on the upper surface of the mesa portion 16 that emits light in the red wavelength band. Is done. A green degree conversion layer 15G in which the multilayer structure 15c and the multilayer structure 15b are sequentially stacked from the upper clad layer 13 side is formed on the upper surface of the mesa unit 16 that emits light in the green wavelength band. Further, a blueness conversion layer 15B made of a multilayer structure 15c is formed on the upper surface of the mesa unit 16 that emits light in the blue wavelength band.

  Next, a plurality of circular resist layers are formed on the surface of the contact layer 14 including the chromaticity conversion layer 15 so as to cover the individual chromaticity conversion layers 15. Subsequently, the contact layer 14 to the upper part of the lower cladding layer 11 are selectively removed by, for example, RIE, using the resist layer as a mask. As a result, a columnar mesa portion 16 extending from the upper portion of the lower cladding layer 11 to the chromaticity conversion layer 15 is formed immediately below the circular resist layer. Thereafter, the resist layer is removed.

  After that, the same process as the manufacturing method of the semiconductor light emitting device 1 is performed. In this way, the semiconductor light emitting element array 2 of the present embodiment is manufactured.

  Next, the operation and effect of the semiconductor light emitting element array 2 of the present embodiment will be described.

[Action / Effect]
In the semiconductor light emitting element array 2 of the present embodiment, when a predetermined voltage is applied between the lower electrode 35 and each upper electrode 31, the current injection region of the current confinement layer 19 in each mesa portion 17. A current is injected into the active layer 12 through 19A, thereby causing light emission due to recombination of electrons and holes. The light generated in the active layer 12 is output from the upper surface of the mesa unit 17 to the outside.

  By the way, also in the present embodiment, as in the first embodiment, the chromaticity conversion layer 15 is formed in a portion of the semiconductor layer 20 that is different from the current path injected by the lower electrode 35 and the upper electrode 31. Has been. Therefore, no current flows through the chromaticity conversion layer 15, and the chromaticity conversion layer 15 has no influence on the driving conditions of the semiconductor light emitting element 1. Therefore, the composition ratio and the laminated structure of the chromaticity conversion layer 15 are not limited by the driving conditions of the semiconductor light emitting device 1.

  Further, as in the first embodiment, a chromaticity conversion layer 15 is provided in the semiconductor layer 20. Thereby, the chromaticity conversion layer 15 can be provided in the semiconductor layer 20 using the same manufacturing method as that for the active layer 12 and the like. Further, since the composition ratio and the laminated structure of the chromaticity conversion layer 15 can be freely changed as described above, the stalk shift amount can be freely changed by changing them appropriately. Therefore, the wavelength conversion structure (chromaticity conversion layer 15) having a large Stoke shift can be provided in the chip (in the semiconductor layer 20) by a simple method.

<Modification of Second Embodiment>
In the second embodiment, the chromaticity conversion layer 15 is provided on the upper surface of the mesa unit 16. However, for example, as illustrated in FIGS. 9 and 10, the chromaticity conversion layer 15 is formed on the back surface of the substrate 10. Also good. In this case, the chromaticity conversion layer 15 is formed by crystal growth on the substrate 10, and the light emission surface 15 </ b> A of the semiconductor light emitting element array 2 is the back surface side of the substrate 10. At this time, the contact layer 14 is exposed on the upper surface of the mesa unit 16. For example, as shown in FIGS. 9 and 10, the upper electrode 31 is formed on the entire upper surface of the mesa unit 16. Also good. In this modification, the chromaticity conversion layer 15, the substrate 10, and the semiconductor layer 20 correspond to a specific example of the “semiconductor layer” of the present invention.

  Although the present invention has been described with reference to a plurality of embodiments and their modifications, the present invention is not limited to the above-described embodiments and the like, and various modifications can be made.

  For example, in the second embodiment and the modifications thereof, each mesa portion 16 is formed by crystal growth on the substrate 10. For example, although not shown, all the mesa portions 16 are formed. At least one of them may be mounted on the substrate 10.

  In each of the above-described embodiments, the present invention has been described by taking a group III-V nitride semiconductor light emitting device as an example. However, the present invention can also be applied to other compound semiconductor light emitting devices.

  In each of the above embodiments and the like, the present invention has been described by taking the LED as an example, but it is of course applicable to a surface emitting semiconductor laser.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor light-emitting device, 2 ... Semiconductor light-emitting device array, 10 ... Substrate, 11 ... Lower clad layer, 12 ... Active layer, 13 ... Upper clad layer, 14 ... Contact layer, 15 ... Chromaticity conversion layer, 15A ... Light emission 15R ... Redness conversion layer, 15G ... Greenness conversion layer, 15B ... Blueness conversion layer, 15a, 15b, 15c ... Multilayer structure, 16 ... Mesa portion, 20 ... Semiconductor layer, 31 ... Upper electrode, 32 ... Insulation Layer, 32A ... opening, 33, 36 ... electrode pad, 34, 37 ... connection, 35 ... lower electrode.

Claims (7)

A plurality of first conductivity type semiconductor layers, active layers, second conductivity type semiconductor layers, and chromaticity conversion layers are arranged in this order, and light emitted from the active layer is output to the outside through the chromaticity conversion layers. A semiconductor layer having a mesa portion;
An electrode disposed at a position where current can be injected into each active layer without going through the chromaticity conversion layer;
With
The chromaticity conversion layer included in the first mesa portion among the plurality of mesa portions has a first multilayer structure that absorbs light emitted from the active layer and emits light having a wavelength in the first wavelength band. And
The chromaticity conversion layer included in the second mesa portion among the plurality of mesa portions absorbs the light emitted from the first multilayer structure and the first multilayer structure, and from the first wavelength band. And a second multilayer structure that emits light of a long wavelength,
The chromaticity conversion layer included in the third mesa portion among the plurality of mesa portions absorbs light emitted from the first multilayer structure, the second multilayer structure, and the second multilayer structure. And a third multilayer structure that emits light having a wavelength longer than that of the second wavelength band.
Semiconductors light emitting element array. A plurality of first conductivity type semiconductor layers, active layers, second conductivity type semiconductor layers, and chromaticity conversion layers are arranged in this order, and light emitted from the active layer is output to the outside through the chromaticity conversion layers. A semiconductor layer having a mesa portion;
An electrode disposed at a position where current can be injected into each active layer without going through the chromaticity conversion layer;
With
The chromaticity conversion layer included in the first mesa portion among the plurality of mesa portions has a first multilayer structure that absorbs light emitted from the active layer and emits light having a wavelength in the first wavelength band. And
The chromaticity conversion layer included in the second mesa portion among the plurality of mesa portions absorbs the light emitted from the active layer and emits light having a wavelength longer than that of the first wavelength band. Has a structure,
A chromaticity conversion layer included in a third mesa portion among the plurality of mesa portions absorbs light emitted from the active layer and emits light having a longer wavelength than the second wavelength band. structure have a,
The semiconductor layer has a semiconductor substrate between the second conductivity type semiconductor layer and the chromaticity conversion layer,
The chromaticity conversion layer is formed by crystal growth on the semiconductor substrate.
Semiconductors light emitting element array. Each mesa portion is a semiconductor light-emitting element array according to claim 1 or claim 2 is constituted by a group III-V nitride semiconductor. The first multilayer structure, the second multilayer structure, and the third multilayer structure are all configured to include In,
4. The semiconductor light-emitting element array according to claim 3 , wherein In composition ratios of the first multilayer structure, the second multilayer structure, and the third multilayer structure are different from each other. The semiconductor layer has a semiconductor substrate on a side opposite to the active layer side in a positional relationship viewed from the first conductivity type semiconductor layer,
Each mesa portion, the semiconductor light-emitting element array array of claim 1 and is formed by crystal growth on a semiconductor substrate. The semiconductor layer has a semiconductor substrate between the second conductivity type semiconductor layer and the chromaticity conversion layer,
The semiconductor light-emitting element array according to claim 1 , wherein the chromaticity conversion layer is formed by crystal growth on the semiconductor substrate. The semiconductor layer has a semiconductor substrate on a side opposite to the active layer side in a positional relationship viewed from the first conductivity type semiconductor layer,
At least one semiconductor light-emitting element array according to claim 1 wherein in which is mounted by the mounting of a semiconductor substrate of all of the mesa portion.

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