JP2012044205A - Optical semiconductor device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical semiconductor device allowing mass production at a low cost and downsizing to the same extent as a semiconductor light-emitting device.SOLUTION: An optical semiconductor device comprises: a light-emitting layer 2 including a stack of semiconductor layers separated from a substrate after being epitaxially grown on the substrate; first and second electrodes 7 formed on a second primary surface of the light-emitting layer; a light-transmitting layer 5 provided on a first primary surface; a fluorescent layer 4 provided on the light-transmitting layer; first and second metal posts 8 provided on the first and second electrodes; and a sealing layer 10 that is provided on the second primary surface, is formed from a material having light shielding properties against the light emitted from the light-emitting layer, seals the first and second metal posts, and covers the side surfaces of the light-emitting layer. The side surfaces of the light-transmitting layer has a portion that is not covered with the fluorescent layer and the sealing layer. A part of the light emitted from the light-emitting layer undergoes wavelength conversion in the fluorescent layer and can be emitted to the outside, and the other part of the light can be emitted to the outside from the side surfaces of the light-transmitting layer.

Description

  Embodiments described herein relate generally to an optical semiconductor device.

  As a small-sized light-emitting element with low power consumption, various semiconductor light-emitting elements are used not only in visible light bands such as red, green, and blue, but also in a wide wavelength band from infrared light to ultraviolet light. In addition, for example, an optical semiconductor device that emits white light by combining a semiconductor light emitting element such as a blue LED (Light Emitting Diode) and a phosphor has been developed.

  The most general-purpose optical semiconductor device that is currently commercialized uses a semiconductor light emitting element in which a semiconductor layer is epitaxially grown on a substrate. That is, a semiconductor layer is epitaxially grown on a substrate such as GaAs, GaP, or sapphire, and an electrode or the like is formed and then divided to obtain each semiconductor light emitting element. The semiconductor light-emitting element thus obtained is mounted on a lead frame, an SMD (Surface Mounting Device) type housing, various mounting substrates, etc., and given wiring is provided. The optical semiconductor device is completed by sealing the element.

JP 2000-183407 A

  Embodiments of the present invention provide an optical semiconductor device that can be mass-produced at low cost and can be downsized to the same extent as a semiconductor light emitting element.

  According to the embodiment, the semiconductor stacked body is epitaxially grown on the substrate and then separated from the substrate, and includes a first main surface and a second main surface that is an opposite surface of the first main surface. A light-emitting layer, a first electrode and a second electrode formed on the second main surface of the light-emitting layer, a light-transmitting layer provided on the first main surface, and provided on the light-transmitting layer A phosphor layer including a phosphor that absorbs light emitted from the light emitting layer and emits light of different wavelengths, a first metal post provided on the first electrode, and a second electrode on the second electrode. A second metal post provided; and a second metal post provided on the second main surface and made of a light-shielding material with respect to light emitted from the light emitting layer; and an end portion of the first metal post and the second metal post. When the end of the metal post is exposed and the first metal post and the second metal post are sealed And a sealing layer covering a side surface of the light emitting layer, and the side surface of the light transmitting layer has a portion not covered with the fluorescent layer and the sealing layer, and is emitted from the light emitting layer. A part of the light propagates through the light-transmitting layer, is wavelength-converted in the fluorescent layer and can be emitted to the outside, and another part of the light emitted from the light-emitting layer propagates through the light-transmitting layer and transmits the light. An optical semiconductor device characterized in that it can be emitted to the outside from the side surface of the layer is provided.

FIG. 1A is a cross-sectional view showing a schematic configuration of the optical semiconductor device according to the present embodiment, and FIG. 1B is a plan view showing a lower surface of the optical semiconductor device shown in FIG. It is a schematic diagram showing the 2nd specific example of 1st Embodiment. It is a schematic diagram showing the 3rd specific example of 1st Embodiment. It is a schematic diagram showing the 4th specific example of 1st Embodiment. It is a schematic diagram showing the 5th example of 1st Embodiment. It is sectional drawing which shows schematic structure of the optical semiconductor device which concerns on 2nd Embodiment, and is sectional drawing corresponding to Fig.1 (a). It is sectional drawing which shows schematic structure of the optical semiconductor device which concerns on 3rd Embodiment. It is sectional drawing which shows schematic structure of the optical semiconductor device which concerns on 4th Embodiment. It is sectional drawing which shows schematic structure of the optical semiconductor device which concerns on 5th Embodiment. It is sectional drawing which shows schematic structure of the optical semiconductor device which concerns on 6th Embodiment. It is sectional drawing which shows schematic structure of the optical semiconductor device which concerns on 7th Embodiment. (A) is sectional drawing showing schematic structure of the optical semiconductor device which concerns on 8th Embodiment, (b) is a top view showing the lower surface of the optical semiconductor device represented to the figure (a). It is process sectional drawing showing the manufacturing method of the optical semiconductor device of 9th Embodiment. It is process sectional drawing showing the manufacturing method of the optical semiconductor device of 9th Embodiment. It is process sectional drawing showing the manufacturing method of the optical semiconductor device of 9th Embodiment. It is process sectional drawing showing a part of manufacturing method of the optical semiconductor device of 10th Embodiment. It is process sectional drawing showing a part of manufacturing method of the optical semiconductor device of 11th Embodiment. It is process sectional drawing showing a part of manufacturing method of the optical semiconductor device of 12th Embodiment. It is process sectional drawing showing a part of manufacturing method of the optical semiconductor device of 13th Embodiment. It is process sectional drawing showing a part of manufacturing method of the optical semiconductor device of 14th Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.
Note that, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.
(First embodiment)
A first embodiment of the present invention will be described with reference to FIG.

  FIG. 1A is a cross-sectional view showing a schematic configuration of the optical semiconductor device according to the present embodiment, and FIG. 1B is a plan view showing a lower surface of the optical semiconductor device shown in FIG.

  As shown in FIG. 1, the optical semiconductor device 1A according to the present embodiment includes a light emitting layer 2 having a first main surface M1 and a second main surface M2, and an adhesive layer provided on the first main surface M1. 3, the translucent layer 5 provided on the adhesive layer 3, the reflective layer 6 provided in the first region of the second main surface M2 of the light emitting layer 2, and the second region of the second main surface M2. The first electrode 7a provided on the plurality of second electrodes 7b provided on the reflective layer 6, the first metal post 8a provided on the first electrode 7a, and the second electrode 7b provided on each of the second electrodes 7b. A plurality of second metal posts 8b, an insulating layer 9 provided on the second main surface M2 of the light emitting layer 2 so as to avoid the metal posts 8a, 8b, and the metal posts 8a, 8b on the insulating layer 9 Sealing layer 10 provided to seal, first metal layer 11a provided at the end of first metal post 8a, and each second metal post A plurality of second metal layer 11b provided on the end of the b, and a.

  The light emitting layer 2 includes a first semiconductor layer 2a, a second semiconductor layer 2b having a smaller area than the first semiconductor layer 2a, and an active layer 2c sandwiched between the first semiconductor layer 2a and the second semiconductor layer 2b. And a semiconductor laminate including: The first semiconductor layer 2a is, for example, a first cladding layer that is an n-type semiconductor layer. The second semiconductor layer 2b is, for example, a second cladding layer that is a p-type semiconductor layer. However, the conductivity type of each of these layers is arbitrary. That is, the first semiconductor layer 2a may be p-type and the second semiconductor layer 2b may be n-type.

  For the first semiconductor layer 2a, the second semiconductor layer 2a, and the active layer 2c, various compound semiconductors such as an InGaAlAs compound semiconductor, an InGaAlAs compound semiconductor, an InGaAlP compound semiconductor, and an InGaAlN based workpiece semiconductor are used. it can.

  For example, by using GaAlAs as the material of the active layer 2c, infrared light or red light emission can be obtained. Further, by using InGaAlP as the material of the active layer 2c, light emission of orange, yellow, green, etc. can be obtained. By using an InGaAlN compound semiconductor as the material of the active layer 2c, green or blue light emission or ultraviolet light can be obtained.

  Each of the first semiconductor layer 2a, the second semiconductor layer 2b, and the active layer 2c is not necessarily a single layer. For example, the active layer 2c may have a multilayer structure in which a quantum well layer and a barrier layer are combined. Similarly, the first semiconductor layer 2a and the second semiconductor layer 2b may have a multilayer structure in which a plurality of semiconductor layers are combined.

  When using an InGaAlN-based compound semiconductor, the first semiconductor layer 2a is an n-type cladding layer containing, for example, GaN. The second semiconductor layer 2b is a p-type cladding layer containing, for example, GaN. The active layer 2c has, for example, a quantum well layer made of InGaN and a barrier layer made of AlGaN stacked on the quantum well layer. Thus, the active layer 2c can have, for example, a single quantum well structure or a multiple quantum well structure.

  In the light emitting layer 2, for example, a crystal that becomes the first semiconductor layer 2a, a crystal that becomes the active layer 2c, and a crystal that becomes the second semiconductor layer 2b are sequentially grown on a substrate (not shown) such as GaAs, GaP, or sapphire. Thereafter, the active layer 2c and the second semiconductor layer 2b in a predetermined region are removed and formed. Further, the substrate (not shown) is also removed from the light emitting layer 2. The thickness of the light emitting layer 2 is, for example, about 5 micrometers.

  The first main surface M1 is the upper surface (in FIG. 1) of the first semiconductor layer 2a, and the second main surface M2 is the lower surface (in FIG. 1) of the first semiconductor layer 2a and the lower surface of the second semiconductor layer 2b (in FIG. 1). 1) and has a step in the middle. That is, the semiconductor stacked body including the first semiconductor layer 2a, the second semiconductor layer 2b, and the active layer 2c has the first main surface M1 and the second main surface M2 opposite to the first main surface M1. And the 1st electrode 7a and the 2nd electrode 7b are provided in the 2nd main surface M2 side of the semiconductor laminated body.

  As shown in FIG. 1B, the planar shape of the first semiconductor layer 2a is, for example, a square having a side of 550 micrometers (see the dotted line in FIG. 1B). On the lower surface (in FIG. 1) of the first semiconductor layer 2a, the second semiconductor layer 2b is formed in a region excluding the corner region (a square of 150 micrometers on a side) of the first semiconductor layer 2a with the active layer 2c in between. Is formed. The active layer 2c has the same shape as the second semiconductor layer 2b and has the same area.

  The adhesive layer 3 is made of, for example, a silicone resin. The thickness of the adhesive layer 3 is, for example, 1 micrometer or less. The adhesive layer 3 adheres the first main surface M1 of the first semiconductor layer 2a of the light emitting layer 2 and the light transmitting layer 5. The silicone resin is, for example, methylphenyl silicone having a refractive index of about 1.5. The resin constituting the adhesive layer 3 may be a silicone resin having another composition such as dimethyl silicone in addition to methylphenyl silicone. Silicone resin is advantageous in the case where emitted light of these wavelengths is emitted from the light emitting layer 2 in terms of high durability against blue and ultraviolet rays.

  On the other hand, when the luminance of the light emitted from the light emitting layer 2 is low or is not deteriorated by blue light, the material of the adhesive layer 3 is an epoxy resin, a hybrid resin of an epoxy resin and a silicone resin, or An appropriate resin such as urethane resin may be used in a timely manner according to the application.

  The translucent layer 5 has translucency with respect to the emitted light emitted from the light emitting layer 2. The light transmissive layer 5 is formed of an inorganic material or an organic material. Examples of the inorganic material include various oxides such as glass, quartz, and aluminum oxide, various nitrides such as silicon nitride, and various fluorides such as magnesium fluoride. Examples of the organic material include acrylic, epoxy, polycarbonate, polypropylene, polyethylene, and silicone resin.

  The thickness of the translucent layer 5 can be set to about 200 micrometers, for example. The material of the light transmissive layer 5 is not limited to a transparent material, and any material that transmits light emitted from the light emitting layer 2 may be used. That is, the material of the light transmissive layer 5 is not required to completely absorb or reflect the emitted light emitted from the light emitting layer 2.

By providing the translucent layer 5, the difference between the refractive index of the first semiconductor layer 2a and the refractive index of air is alleviated, so that the light extraction efficiency can be increased. That is, by providing the light transmitting layer 5 with an intermediate refractive index between the refractive index of the first semiconductor layer 2a and the refractive index of air, the emitted light emitted from the light emitting layer 2 is extracted from the light extraction surface of the light emitting layer 2. Can be prevented from being totally reflected. As a result, it is possible to improve the efficiency of taking out the emitted light emitted from the light emitting layer 2 to the outside (in the air).
From this viewpoint, it is desirable that the light transmissive layer 5 is formed of a light transmissive material having a refractive index in the range of 1 to 2.

  As will be described in detail later with specific examples, the light-transmitting layer 5 can have an action of changing the traveling direction of light, such as a lens action or a refraction action. Thereby, the radiation angle of the light emitted from the light emitting layer 2 can be adjusted.

  The reflective layer 6 is made of a metal such as Ag or Al. The thickness of the reflective layer 6 is, for example, 0.3 micrometers. The reflective layer 6 is provided in the entire region (first region) of the lower surface (in FIG. 1) of the second semiconductor layer 2b of the light emitting layer 2. Specifically, a Ni / Au contact electrode (not shown) is formed of a metal such as Ni / Au with a thickness of 0.1 micrometers / 0.1 micrometers on the lower surface of the second semiconductor layer 2b. A reflective layer 6 having a thickness of 0.3 micrometers is formed thereon.

  The first electrode 7a is formed of a metal such as Ni / Au with a thickness of 0.1 micrometers / 0.1 micrometers, for example. The thickness of the first electrode 7a is, for example, 0.2 micrometers. For example, the first electrode 7a is provided in a circular shape having a diameter of 100 micrometers on the exposed region (second region) of the lower surface (FIG. 1A) of the first semiconductor layer 2a of the light emitting layer 2 (FIG. 1). 1 (b)).

  Each second electrode 7b is also formed of a metal such as Ni / Au with a thickness of 0.1 micrometers / 0.1 micrometers, for example. The thickness of each second electrode 7b is, for example, 0.2 micrometers. These second electrodes 7b are provided on the lower surface (FIG. 1A) of the reflective layer 6 in a circular shape with a diameter of 100 micrometers, for example, at a pitch of 200 micrometers (see FIG. 1B).

  The first metal post 8a is formed in a columnar shape from a metal such as Cu. The height of the first metal post 8a is, for example, about 100 micrometers, and the diameter thereof is, for example, 100 micrometers. The first metal post 8a is energized to the first electrode 7a. The shapes of the first electrode 7a and the first metal post 8a can be changed as appropriate.

  Each of the second metal posts 8b is formed in a columnar shape with a metal such as Cu, for example. The height of the second metal post 8b is, for example, 100 micrometers, and the diameter thereof is, for example, 100 micrometers. The second metal post 8b is energized to the second electrode 7b. The second metal posts 8b are provided at a pitch of, for example, 200 micrometers, as in the arrangement of the second electrodes 7b (see FIG. 2). In addition, the shape of the 2nd electrode 7b and the 2nd metal post 8b can also be changed suitably.

The insulating layer 9 is made of an insulating material such as SiO ₂ and functions as a passivation film (protective film). The thickness of the insulating layer 9 is, for example, 0.3 micrometers. The insulating layer 9 completely covers the light emitting layer 2 up to its end portion, and prevents external energization except for the first electrode 7a and the second electrodes 7b. Thereby, it is possible to prevent a short circuit or the like due to the rising of the mounting solder.

The sealing layer 10 is made of, for example, a thermosetting resin. The thickness of the sealing layer 10 is about 100 micrometers like each metal post 8a, 8b. The sealing layer 10 is formed of the insulating layer 9 so as to seal the first metal post 8a and each second metal post 8b by exposing the end of the first metal post 8a and the end of each second metal post 8b. It is provided on the entire surface. As a result, the peripheral surfaces of the first metal posts 8 a and the second metal posts 8 b are completely covered with the sealing layer 10.
Furthermore, the sealing layer 10 also covers the side surface of the light emitting layer 2. That is, as illustrated in FIG. 1A, the side surface between the first main surface M <b> 1 and the second main surface M <b> 2 of the light emitting layer 2 is covered with the sealing layer 10 via the insulating layer 9. ing. This can be applied not only to this embodiment but also to all embodiments described later with reference to FIGS. When the sealing layer 10 is formed of a material that blocks light emitted from the light emitting layer 2, the side surface of the light emitting layer 2 is covered with the sealing layer 10, so that light from the side surface of the light emitting layer 2 can be transmitted. Leakage can be prevented.

  In addition, although the insulating layer 9 is provided so that the light emitting layer 2 may be covered completely to the edge part, this embodiment is not restricted to this. For example, the sealing layer 10 may be provided so as to completely cover the light emitting layer 2 up to its end instead of the insulating layer 9. Even in this case, since electrical conduction with the outside is prevented except for the first electrode 7a and each second electrode 7b, a short circuit or the like due to rising of the mounting solder can be prevented.

  The first metal layer 11a and each second metal layer 11b are made of a metal such as Ni / Au with a thickness of 1.0 micrometers / 0.1 micrometers, for example. The first metal layer 11a is provided at the end of the first metal post 8a, that is, at the exposed portion. Each second metal layer 11b is provided at an end portion of each second metal post 8b, that is, an exposed portion. The first metal layer 11a has the same circular shape as the first electrode 7a, and the second metal layer 11b has the same circular shape as the second electrode 7b (see FIG. 1B).

  In such an optical semiconductor device 1A, when a voltage is applied to the first metal post 8a and each second metal post 8b, a potential is applied from the first metal post 8a to the first semiconductor layer 2a. A potential is applied from the post 8b to the second semiconductor layer 2b, and light is emitted from the active layer 2c sandwiched between the first semiconductor layer 2a and the second semiconductor layer 2b. A part of the emitted light is transmitted through the light-transmitting layer 5 and emitted as it is from the surface of the light-transmitting layer 5, and the other part is reflected by the reflecting layer 6 and transmitted through the light-transmitting layer 5. It is emitted from the surface of the optical layer 5.

According to the structure of this embodiment, the device configuration is simplified, and a small optical semiconductor device 1A having the same size as the plane area of the light emitting layer 2 can be obtained. Furthermore, it is not necessary to perform a molding process, a mounting process, a connection process, and the like at the time of manufacturing, and manufacturing by a normal semiconductor manufacturing apparatus is possible, so that costs can be suppressed.
In addition, by forming the light-transmitting layer 5 on the light emitting layer 2, it becomes possible to alleviate the difference in refractive index between the light emitting layer 2 and air, so that the light extraction efficiency can be improved. Further, according to the structure of the present embodiment, even when the optical semiconductor device 1A having the same size as the plane area of the light emitting layer 2 is mounted on a glass epoxy substrate which is a general wiring board, the glass epoxy substrate and the light emitting layer 2 are mounted. It is possible to relieve the difference in linear expansion coefficient between the metal posts 8a and 8b. As a result, the reliability at the time of mounting the optical semiconductor device 1A can be ensured.

As described above, according to the first embodiment of the present invention, a light-transmitting inorganic or organic material is provided as the light-transmitting layer 5 on the light-emitting layer 2, and the first electrode 7a of the light-emitting layer 2 is further provided. A first metal post 8a is provided thereon, a second metal post 8b is provided on each second electrode 7b of the light emitting layer 2, and a sealing layer for sealing the first metal post 8a and each second metal post 8b is provided. By providing 10 on the light emitting layer 2, the optical semiconductor device 1A having the above-described structure is obtained.
According to this optical semiconductor device 1A, when the light-transmitting layer 5 is formed of an inorganic material, silicone resin, or the like, deterioration of the light-transmitting layer 5 due to light (particularly blue light) emitted from the light-emitting layer 2 is prevented. Therefore, it is possible to suppress a decrease in life. Furthermore, since the apparatus configuration is simplified and manufacturing costs are reduced, cost reduction can be realized. In addition, since the device configuration is simplified and the planar size of the device is about the same as the plane area of the light emitting layer 2, the optical semiconductor device 1A can be miniaturized to the same extent as a normal optical semiconductor element. .

Furthermore, according to the present embodiment, it is possible to impart an optical function to the light transmitting layer 5.
FIG. 2 is a schematic diagram illustrating a second specific example of the present embodiment. 2A is a cross-sectional view of the optical semiconductor device of this example, and FIG. 2B is a plan view as viewed from the Z direction. FIG. 2A shows a cross section taken along line AA of FIG.

In this specific example, a convex lens 5 a is formed on the light extraction surface of the translucent layer 5. Thereby, the condensing effect | action of the light discharge | released from the light emitting layer 2 is obtained.
FIG. 3 is a schematic diagram illustrating a third specific example of the present embodiment. 3A is a cross-sectional view of the optical semiconductor device of this example, and FIG. 3B is a plan view as viewed from the Z direction. FIG. 3A shows a cross section taken along line AA of FIG.

In this specific example, a concave lens 5 b is formed on the light extraction surface of the translucent layer 5. In this way, the light emitted from the light emitting layer 2 can be expanded to control the light distribution characteristics.
FIG. 4 is a schematic diagram illustrating a fourth specific example of the present embodiment. 4A is a cross-sectional view of the optical semiconductor device of this example, and FIG. 4B is a plan view viewed from the Z direction. FIG. 4A shows a cross section taken along the line AA in FIG.

In this specific example, a plurality of convex lenses 5 a are formed on the light extraction surface of the translucent layer 5. Even in this case, the light emitted from the light emitting layer 2 can be emitted as a plurality of convergent lights.
FIG. 5 is a schematic diagram illustrating a fifth specific example of the present embodiment. 5A is a cross-sectional view of the optical semiconductor device of this example, and FIG. 5B is a plan view viewed from the Z direction. FIG. 5A shows a cross section taken along the line AA in FIG.

  In this specific example, a Fresnel lens 5 c is formed on the light extraction surface of the translucent layer 5. By forming the Fresnel lens 5c, it is possible to control the light distribution characteristics by condensing the light emitted from the light emitting layer 2 while reducing the thickness of the light transmitting layer 5.

According to this embodiment, the translucent layer 5 is bonded to the light emitting layer 2 by the adhesive layer 3. That is, it is easy to previously mold the translucent layer 5 as a separate member from the light emitting layer 2. Therefore, it is possible to manufacture an optical semiconductor device provided with the translucent layer 5 having various lens shapes as described above with reference to FIGS. 2 to 5 or other various light distribution characteristics at low cost. It becomes.
(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the differences from the first embodiment will be mainly described. In addition, regarding this embodiment, the same part as the part demonstrated regarding 1st Embodiment is attached | subjected with the same code | symbol, and the description is abbreviate | omitted suitably.

FIG. 6 is a cross-sectional view showing a schematic configuration of the optical semiconductor device according to the present embodiment, and is a cross-sectional view corresponding to FIG.
In the present embodiment, the light transmitting layer 5 is directly provided on the light emitting layer 2. That is, the translucent layer 5 is formed on the light emitting layer 2 without using the adhesive layer 3 (see FIG. 1).
Such a structure can be realized, for example, by forming the translucent layer 5 from a resin. For example, a resin material before curing is applied on the first main surface M1 of the light emitting layer 2. Thereafter, the resin material is cured by heat, UV (ultraviolet light) or the like. In this way, the light transmissive layer 5 can be formed directly on the light emitting layer 2.
Alternatively, the light-transmitting layer 5 can be formed by applying, for example, liquid glass on the first main surface M1 of the light emitting layer 2 by a method such as spin coating and curing the liquid glass.

According to the present embodiment, in addition to the various functions and effects described above with reference to the first embodiment, light absorption and scattering by the adhesive layer 3 can be suppressed, and the light extraction efficiency can be further improved.
In addition, since the process of forming the adhesive layer 3 can be eliminated in the manufacturing process, the process can be shortened and the cost can be reduced.

In the present embodiment as well, various optical functions described above with reference to FIGS. 2 to 5 can be imparted to the transmission layer 5. For example, using a mold corresponding to the shape of a predetermined convex lens, concave lens, Fresnel lens, or the like, the resin material on the first main surface M1 of the light emitting layer 2 may be cured while being controlled. Alternatively, imprinting (embossing) may be performed with a stamp corresponding to the shape of a predetermined convex lens, concave lens, Fresnel lens, or the like before the resin material on the first main surface M1 of the light emitting layer 2 is cured.
(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, differences from the first and second embodiments will be mainly described. In addition, regarding this embodiment, the same part as the part demonstrated regarding 1st and 2nd embodiment is attached | subjected with the same code | symbol, and the description is abbreviate | omitted suitably.

FIG. 7 is a cross-sectional view showing a schematic configuration of the optical semiconductor device according to the present embodiment.
In the present embodiment, the fluorescent layer 4 is provided on the light emitting layer 2 via the adhesive layer 3. The fluorescent layer 4 contains phosphor particles that convert the wavelength of the light emitted from the light emitting layer 2. Specifically, the phosphor layer 4 has a structure in which phosphor particles are dispersed in an organic material such as a silicone resin. Moreover, the fluorescent layer 4 may be one in which phosphor particles are dispersed in an inorganic material such as silicon oxide. The thickness of the fluorescent layer 4 can be about 15 micrometers, for example. Alternatively, the fluorescent layer 4 may be formed by combining phosphor particles with a binder made of an organic material or an inorganic material.

  When a silicone resin is used as the organic material used for the fluorescent layer 4, the same type of resin as the adhesive layer 3 and methylphenyl silicone having a refractive index of about 1.5 can be used. However, the material of the fluorescent layer 4 is not limited to this, and may be another kind of organic material or inorganic material.

  The phosphor contained in the phosphor layer 4 need not have one composition. For example, two types of phosphors that convert blue light into green light and red light may be mixed and used. If it does in this way, the blue light discharge | released from the light emitting layer 2, the green light and the red light which were wavelength-converted by fluorescent substance can be mixed, and white light with high color rendering property can be obtained.

  Moreover, the fluorescent layer 4 does not need to be a single layer. For example, a first layer in which phosphor particles that absorb blue light and emit green light are dispersed; a second layer in which phosphor particles that absorb blue light and emit red light are dispersed; The laminated body which laminated | stacked these may be sufficient. In this case, when the first layer and the second layer are stacked in this order from the light emitting layer 2 side, loss due to absorption of green light in the first layer can be reduced.

Examples of the red phosphor include the following. However, the red phosphor used in the embodiment is not limited to these.
Y ₂ O ₂ S: Eu,
Y ₂ O ₂ S: Eu + pigment,
Y ₂ O ₃ : Eu,
Zn ₃ (PO ₄ ) ₂ : Mn,
(Zn, Cd) S: Ag + In ₂ O ₃ ,
(Y, Gd, Eu) BO ₃ ,
(Y, Gd, Eu) ₂ O ₃ ,
YVO ₄ : Eu,
La ₂ O ₂ S: Eu, Sm,
LaSi ₃ N ₅ : Eu ²⁺ ,
α-sialon: Eu ²⁺ ,
CaAlSiN ₃ : Eu ²⁺ ,
CaSiN _X : Eu ²⁺ ,
CaSiN _X : Ce ²⁺ ,
M ₂ Si ₅ N ₈ : Eu ²⁺ ,
CaAlSiN ₃ : Eu ²⁺ ,
(SrCa) AlSiN ₃ : Eu ^{X +} ,
Sr _x (Si _y Al ₃ ) _z (O _x N): Eu ^{X +}

Examples of the green phosphor include the following. However, the green phosphor used in the embodiment is not limited to these.
ZnS: Cu, Al,
ZnS: Cu, Al + pigment,
(Zn, Cd) S: Cu, Al,
ZnS: Cu, Au, Al, + pigment,
Y ₃ Al ₅ O ₁₂ : Tb,
Y ₃ (Al, Ga) ₅ O ₁₂ : Tb,
Y ₂ SiO ₅ : Tb,
Zn ₂ SiO ₄ : Mn,
(Zn, Cd) S: Cu,
ZnS: Cu,
Zn ₂ SiO ₄ : Mn,
ZnS: Cu + Zn ₂ SiO ₄ : Mn,
Gd ₂ O ₂ S: Tb,
(Zn, Cd) S: Ag,
ZnS: Cu, Al,
Y ₂ O ₂ S: Tb,
ZnS: Cu, Al + In ₂ O ₃ ,
(Zn, Cd) S: Ag + In ₂ O ₃ ,
(Zn, Mn) ₂ SiO ₄ ,
BaAl ₁₂ O ₁₉ : Mn
(Ba, Sr, Mg) O.aAl ₂ O ₃ : Mn,
LaPO ₄ : Ce, Tb,
Zn ₂ SiO ₄ : Mn,
ZnS: Cu,
3 (Ba, Mg, Eu, Mn) O.8Al ₂ O ₃ ,
_{La 2 O 3 · 0.2SiO 2 ·} 0.9P 2 O 5: Ce, Tb,
CeMgAl ₁₁ O ₁₉ : Tb,
CaSc ₂ O ₄ : Ce,
(BrSr) SiO ₄ : Eu,
α-sialon: Yb ²⁺ ,
β-sialon: Eu ²⁺ ,
(SrBa) YSi ₄ N ₇ : Eu ²⁺ ,
(CaSr) Si ₂ O ₄ N ₇ : Eu ²⁺ ,
Sr (SiAl) (ON): Ce

Examples of the blue phosphor include the following. However, the blue phosphor used in the embodiment is not limited to these.
ZnS: Ag,
ZnS: Ag + pigment,
ZnS: Ag, Al,
ZnS: Ag, Cu, Ga, Cl,
ZnS: Ag + In ₂ O ₃ ,
ZnS: Zn + In ₂ O ₃ ,
(Ba, Eu) MgAl ₁₀ O ₁₇ ,
(Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) 6 Cl ₂ : Eu,
Sr ₁₀ (PO ₄ ) 6Cl ₂ : Eu,
(Ba, Sr, Eu) (Mg, Mn) Al ₁₀ O ₁₇ ,
10 (Sr, Ca, Ba, Eu) · 6PO ₄ · Cl ₂ ,
BaMg ₂ Al ₁₆ O ₂₅ : Eu

Examples of the yellow phosphor include the following. However, the yellow phosphor used in the embodiment is not limited to these.
Li (Eu, Sm) W ₂ O ₈ ,
(Y, Gd) ₃ , (Al, Ga) ₅ O ₁₂ : Ce ³⁺ ,
Li ₂ SrSiO ₄ : Eu ²⁺ ,
(Sr (Ca, Ba)) ₃ SiO ₅ : Eu ²⁺ ,
SrSi ₂ ON _2.7 : Eu ²⁺

  According to the structure of the present embodiment, the fluorescent layer 4 for converting the wavelength of light is provided on the light emitting layer 2, and light in various wavelength bands can be obtained. For example, when blue light is emitted from the light emitting layer 2, white light can be obtained by including in the fluorescent layer 4 a phosphor that absorbs blue light and emits yellow light. That is, white light is obtained by mixing the blue light from the light emitting layer 2 and the yellow light from the fluorescent layer 4.

  According to the structure of the present embodiment, the reflective layer 6 is formed on the lower surface (in FIG. 7) of the light emitting layer 2 to emit blue light only in the upward direction, whereby white light is emitted in the upper surface direction of the optical semiconductor device 1C. Can emit light.

Further, by dispersing phosphor particles in a material such as resin or glass as the fluorescent layer 4, it becomes possible to reduce the refractive index difference between the fluorescent layer 4 and air, thereby improving the light extraction efficiency. be able to.
(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, differences from the first to third embodiments will be mainly described. In addition, regarding this embodiment, the same part as the part demonstrated regarding the 1st thru | or 3rd embodiment is attached | subjected with the same code | symbol, and the description is abbreviate | omitted suitably.

FIG. 8 is a cross-sectional view showing a schematic configuration of the optical semiconductor device according to the present embodiment.
In the present embodiment, the fluorescent layer 4 is directly provided on the light emitting layer 2. That is, the fluorescent layer 4 is formed on the light emitting layer 2 without using the adhesive layer 3 (see FIG. 7).

  Such a structure can be realized, for example, by forming the fluorescent layer 4 using a resin. For example, a resin material before curing in which phosphor particles are dispersed is applied on the first main surface M1 of the light emitting layer 2. Thereafter, the resin material is cured by heat, UV (ultraviolet light) or the like. By doing so, the fluorescent layer 4 can be formed directly on the light emitting layer 2. Use of a silicone resin as the resin constituting the fluorescent layer 4 is advantageous in that it has high durability against blue light and ultraviolet light, and can suppress deterioration such as discoloration even after long-term lighting.

  Alternatively, the fluorescent layer 4 is formed on the first main surface M1 of the light emitting layer 2 by applying, for example, a liquid glass in which phosphor particles are dispersed by a method such as spin coating and curing the liquid glass. be able to. In this case as well, glass is advantageous in that it has high durability against blue light and ultraviolet light and can suppress deterioration such as discoloration even after long-term lighting.

  Alternatively, the fluorescent layer 4 may be formed on the light emitting layer 2 by sputtering or CVD (Chemical Vapor Deposition). That is, the phosphor material can be deposited on the light emitting layer 2 by sputtering or CVD. In this way, it is possible to form the fluorescent layer 4 containing a high concentration of phosphor.

  Also in this embodiment, the fluorescent layer 4 does not need to be a single layer. For example, a first layer in which phosphor particles that absorb blue light and emit green light are dispersed; a second layer in which phosphor particles that absorb blue light and emit red light are dispersed; The laminated body which laminated | stacked these may be sufficient.

Further, according to the present embodiment, in addition to the various effects described above with respect to the third embodiment, it is possible to suppress light absorption and scattering by the adhesive layer 3 and further improve the light extraction efficiency. Become.
(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, parts different from the first to fourth embodiments will be mainly described. In addition, regarding this embodiment, the same part as the part demonstrated regarding 1st thru | or 4th embodiment is attached | subjected with the same code | symbol, and the description is abbreviate | omitted suitably.

FIG. 9 is a cross-sectional view illustrating a schematic configuration of the optical semiconductor device according to the present embodiment.
In the present embodiment, the light transmitting layer 5 and the fluorescent layer 4 are provided in this order on the light emitting layer 2 via the adhesive layer 3. The adhesive layer 3 and the translucent layer 5 can be the same as those described above with respect to the first embodiment. Further, the fluorescent layer 4 may be the same as that described above with respect to the third and fourth embodiments.

  For example, an uncured resin material in which phosphor particles are dispersed is applied on the light transmitting layer 5. Thereafter, the resin material is cured by heat, UV (ultraviolet light) or the like. By doing so, the fluorescent layer 4 can be formed directly on the light transmitting layer 5. Thus, the light-transmitting layer 5 on which the fluorescent layer 4 is formed may be bonded to the light emitting layer 2 through the adhesive layer 3.

  Use of a silicone resin as the resin constituting the fluorescent layer 4 is advantageous in that it has high durability against blue light and ultraviolet light, and can suppress deterioration such as discoloration even after long-term lighting.

  Alternatively, the fluorescent layer 4 can be formed by applying, for example, a liquid glass in which phosphor particles are dispersed on the light-transmitting layer 5 by a method such as spin coating and curing the liquid glass. In this case as well, glass is advantageous in that it has high durability against blue light and ultraviolet light and can suppress deterioration such as discoloration even after long-term lighting.

  Alternatively, the fluorescent layer 4 may be formed on the light transmitting layer 5 by sputtering or CVD (Chemical Vapor Deposition). That is, the phosphor material can be deposited on the light emitting layer 2 by sputtering or CVD. In this way, it is possible to form the fluorescent layer 4 containing a high concentration of phosphor.

  According to the present embodiment, the light emitted from the light emitting layer 2 is first guided to the light transmitting layer 5, whereby the light distribution characteristic or the luminance distribution can be made more uniform. That is, when light emitted from the light emitting layer 2 enters the light transmitting layer 5 and propagates through the light transmitting layer 5, the light transmitting layer 5 acts as a light guide and alleviates unevenness in light luminance. It becomes possible to make it. In this way, the light with reduced luminance unevenness is incident on the fluorescent layer 4 and wavelength-converted, whereby the color unevenness of the light emitted to the outside can be made more uniform.

  For example, when blue light is emitted from the light emitting layer 2 and a part thereof is converted into yellow light in the fluorescent layer 4 and is extracted to the outside as white light, if the intensity of the blue light incident on the fluorescent layer 4 is strong, The blue component may become strong. That is, if the luminance of the blue light emitted from the light emitting layer 2 is uneven, white light extracted outside through the fluorescent layer 4 also has an uneven blue component. This may be recognized as color unevenness by the observer.

On the other hand, in the present embodiment, the light emitted from the light emitting layer 2 is first guided to the light transmissive layer 5 and guided therethrough, thereby reducing unevenness in luminance. As a result, color unevenness of light extracted outside can be reduced.
(Sixth embodiment)
A sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, differences from the first to fifth embodiments will be mainly described. In addition, regarding this embodiment, the same part as the part demonstrated regarding 1st thru | or 5th embodiment is attached | subjected with the same code | symbol, and the description is abbreviate | omitted suitably.

FIG. 10 is a cross-sectional view showing a schematic configuration of the optical semiconductor device according to the present embodiment.
In the present embodiment, the light transmitting layer 5 and the fluorescent layer 4 are provided in this order on the light emitting layer 2. That is, the light-transmitting layer 5 and the fluorescent layer 4 are directly formed on the light emitting layer 2 without the adhesive layer 3 (see FIG. 9).

  The translucent layer 5 can be the same as that described above with respect to the second embodiment. The fluorescent layer 4 can be the same as that described above with respect to the third to fifth embodiments.

Also in the embodiment, by providing the light-transmitting layer 5 and the fluorescent layer 4 in this order on the light emitting layer 2, the effects described above with respect to the fifth embodiment can be obtained similarly.
Furthermore, in this embodiment, since the adhesive layer 3 is not used, light absorption and scattering by the adhesive layer 3 can be suppressed, and the light extraction efficiency can be further improved.
In addition, since the process of forming the adhesive layer 3 can be eliminated in the manufacturing process, the process can be shortened and the cost can be reduced.
(Seventh embodiment)
A seventh embodiment of the present invention will be described with reference to FIG. In the present embodiment, parts different from the first to sixth embodiments will be mainly described. In addition, regarding this embodiment, the same part as the part demonstrated regarding 1st thru | or 6th embodiment is attached | subjected with the same code | symbol, and the description is abbreviate | omitted suitably.

FIG. 11 is a cross-sectional view showing a schematic configuration of the optical semiconductor device according to the present embodiment.
In the optical semiconductor device 1G according to the present embodiment, the first metal layer 11a and each second metal layer 11b are solder bumps. That is, hemispherical solder bumps having a diameter of 100 micrometers are formed on the first metal posts 8a and the second metal posts 8b. The composition of the solder bump is a solder material used for surface mounting such as Sn-3.0Ag-0.5Cu, Sn-0.8Cu, Sn-3.5Ag.

According to the present embodiment, the same effect as that of the first embodiment can be obtained. Furthermore, when the optical semiconductor device 1G is mounted on the wiring board by forming the first metal layer 11a and the second metal layers 11b with solder bumps, the optical semiconductor device 1G is compared with the optical semiconductor device 1A according to the first embodiment. In addition, since the gap between the optical semiconductor device 1G and the wiring board is increased by the solder bumps, the stress generated by the difference in linear expansion coefficient when heated can be further relaxed.
Instead of the solder bumps, for example, metal bumps formed of indium or the like may be provided. Such metal bumps can be joined by, for example, pressure bonding while applying heat or ultrasonic waves.

Moreover, although the structure of 1st Embodiment was illustrated in FIG. 11, this embodiment is not limited to this. That is, in any of the second to sixth embodiments, a similar effect can be obtained by providing solder bumps or metal bumps.
(Eighth embodiment)
An eighth embodiment of the present invention will be described with reference to FIG. In the eighth embodiment of the present invention, parts different from the first to seventh embodiments will be described. In the eighth embodiment, the same parts as those described in the first to seventh embodiments are denoted by the same reference numerals, and the description thereof is omitted.

12A is a cross-sectional view illustrating a schematic configuration of the optical semiconductor device according to the present embodiment, and FIG. 12B is a plan view illustrating a lower surface of the optical semiconductor device illustrated in FIG. .
In the optical semiconductor device 1H according to the present embodiment, a square first electrode 7a having a side of 100 micrometers, for example, is formed on the lower surface of the first cladding layer 2a. On the other hand, the second electrode 7b on the lower surface of the second cladding layer 2b has a shape of, for example, a square having a side of 500 micrometers and a corner region of the first cladding layer 2a lacking, for example, a square region having a side of 150 micrometers. The first metal post 8a is a rectangular parallelepiped prism with the same planar shape as the first electrode 7a, and the second metal post 8b is a prism with the same planar shape as the second electrode 7b. Furthermore, the first metal layer 11a has the same planar shape as the first electrode 7a, and the second metal layer 11b has the same planar shape as the second electrode 7b (see FIG. 12B).

  According to this embodiment, the same effect as that of the first embodiment can be obtained. Furthermore, compared with the optical semiconductor device 1A according to the first embodiment, the plane areas of the first electrode 7a and the second electrode 7b are increased, that is, by increasing the first metal post 8a and the second metal post 8b. Since the heat dissipation path for releasing the heat generated by the light emission is increased, the heat resistance can be reduced by reducing the thermal resistance, and the transient thermal resistance can be greatly reduced.

In addition, although the structure of 1st Embodiment was illustrated in FIG. 12, this embodiment is not limited to this. That is, in any of the second to sixth embodiments, by increasing the plane area of the first electrode 7a and the second electrode 7b, it is possible to reduce the amount of heat generated when current is applied by reducing the thermal resistance. At the same time, the transient thermal resistance can be greatly reduced.
(Ninth embodiment)
A ninth embodiment of the present invention will be described with reference to FIGS. The present embodiment is a method for manufacturing the optical semiconductor device 1A according to the first embodiment and the optical semiconductor device 1C according to the third embodiment. In the description of this embodiment, the same parts as those described in the first to eighth embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  13 to 15 are process cross-sectional views showing the method for manufacturing the optical semiconductor device of this embodiment. Here, as an example, the method for manufacturing the optical semiconductor device 1A according to the first embodiment is shown.

  First, as shown in FIG. 13A, for example, an InGaN blue light emitting layer 12 of, for example, InGaN is formed on a substrate 11 which is a sapphire wafer having a diameter of 2 inches and a thickness of 200 micrometers. The light emitting layer 12 is first formed by epitaxial growth of the original light emitting layer, and the light emitting layer is individualized by RIE (reactive ion etching) processing. Thereby, the light emitting layer 2 of the optical semiconductor device 1A is formed. In the light emitting layer 2, for example, a first cladding layer 2a is formed in a square region having a side of 550 micrometers, and an active layer 2c is sandwiched between the lower surface of the first cladding layer 2a, and a corner region of the first cladding layer 2a ( The second cladding layer 2b is formed in a region excluding a square having a side of 150 micrometers (see FIG. 1).

Next, as shown in FIG. 13B, the multilayer film 13 is formed on each light emitting layer 12 on the substrate 11. First, a Ni / Au film (not shown) having a thickness of 0.1 micrometer / 0.1 micrometer is formed by sputtering on the entire surface of the light emitting layer 12 as a contact layer of the light emitting layer 12, and on the film. An Ag or Al metal film (not shown) is formed by sputtering to a thickness of 0.3 micrometers. Thereby, the reflective layer 6 of the optical semiconductor device 1A is formed. Thereafter, a Ni / Au film (not shown) having a thickness of 0.1 micrometer / 0.1 micrometer is formed on the electrode portion of the light emitting layer 12 as an electrode material, and the thickness is 0 in a region other than the electrode portion. A passivation film (not shown) of a 3 micrometer SiO ₂ film is formed by sputtering. As a result, the first electrode 7a, each second electrode 7b, and the insulating layer 9 of the optical semiconductor device 1A are formed. In this way, the multilayer film 13 is formed on each light emitting layer 2 on the substrate 11.

  Next, as shown in FIG. 13C, a seed layer 14 which is a conductive film serving as a power feeding layer for plating is formed over the entire surface of the substrate 11 by a physical deposition method such as a vapor deposition method or a sputtering method. The As the seed layer 14, for example, a laminated film such as Ti / Cu is used. Here, the Ti layer is formed for the purpose of increasing the adhesion strength with the resist or pad. Therefore, the film thickness may be about 0.1 micrometers. On the other hand, since Cu mainly contributes to power feeding, the film thickness is preferably 0.2 micrometers or more.

  Next, as shown in FIG. 13D, a resist layer 15, which is a sacrificial layer having an electrode pad portion that is the first electrode 7 a and each second electrode 7 b portion, is formed over the entire surface of the substrate 11. As the resist, a photosensitive liquid resist or a dry film resist can be used. The resist layer 15 is formed on the entire surface of the substrate 11 by first forming a resist layer as a base, and then using a light shielding mask for forming an opening, and forming the opening by exposure and development. The developed resist is baked if necessary depending on the material.

  Subsequently, as shown in FIG. 14A, a plating layer 16 is formed in the opening of the resist layer 15 by electroplating. Thereby, the metal posts 8a and 8b of the optical semiconductor device 1A are formed. In electroplating, for example, the wafer substrate 11 is immersed in a plating solution made of copper sulfate and sulfuric acid, and the negative electrode of the DC power source is connected to the seed layer 14 so as to face the surface to be plated of the substrate 11. The anode of the direct current power source is connected to the Cu plate serving as the installed anode, current is passed, and Cu plating is started. The thickness of the plating film increases with time, but before the thickness of the resist layer 15 is reached, the energization is stopped and the plating is completed.

  After the plating, as shown in FIG. 14B, the resist layer 15 is peeled off from the substrate 11 and removed. Thereafter, the seed layer 14 is removed by etching by acid cleaning. Thereby, the light emitting layer 12, the multilayer film 13, and the plating layer 16 are exposed.

  Next, as shown in FIG. 14C, a thermosetting resin layer 17 that becomes a sealing layer is formed over the entire surface of the substrate 11. First, a thermosetting resin is supplied to the periphery of the plating layer 16 by spin coating so as to fill the plating layer 16, and then put into an oven, and the thermosetting resin layer 17 is cured by heating. For example, the resin is cured by heating at 150 ° C. for 2 hours.

  Thereafter, as shown in FIG. 14D, the surface of the thermosetting resin layer 17 is ground to expose the plating layer 16. Thereby, the sealing layer 10 of the optical semiconductor device 1A is formed. A rotating polishing wheel is used for grinding the thermosetting resin layer 17, and grinding can be completed while ensuring flatness by rotating grinding. After grinding is completed, drying may be performed as necessary. In this grinding step, it is difficult to apply the thermosetting resin by exposing only the end portion of the plating layer 16 by spin coating or the like in the previous step (the application time and cost are high). This step is necessary to expose the end of the substrate.

  Next, as shown in FIG. 15A, laser is irradiated between the substrate 11 and the light emitting layer 12, and the light emitting layer 12 is lifted off from the substrate 11. That is, the light emitting layer 12 is separated from the substrate 11 and peeled off. As a result, the light emitting base 12 </ b> A composed of the light emitting layer 12, the multilayer film 13, the plating layer 16, and the thermosetting resin layer 17 is separated from the substrate 11. The lift-off is performed by irradiating a laser beam having a wavelength of 355 nm through the substrate 11 between the light emitting layer 12 and the third harmonic laser of Nd: YAG. Note that lift-off is an option and can be omitted.

  In addition, here, a specific example in which a gallium nitride crystal is grown on the substrate 11 of the sapphire wafer and separated from the substrate 11 has been described, but the present embodiment is not limited to this. For example, it is possible to grow an InGaAlP-based crystal on a GaAs substrate and remove the GaAs substrate by a method such as etching to form the light emitting layer 12. Light emitted from the InGaAlP-based crystal is absorbed by the GaAs substrate. By removing the GaAs substrate in this way, the light emitted from the InGaAlP-based light-emitting layer is not absorbed by the GaAs substrate, and the external Can be taken out.

  Next, as illustrated in FIG. 15B, the light emitting base material 12 </ b> A formed by lift-off is bonded to the light transmitting base material 18 such as an optical glass wafer with the light emitting layer 12 facing through the adhesive layer 20. The In a separate step, a silicone resin layer is formed as the adhesive layer 20 on the translucent substrate 18 made of a translucent inorganic substance. In this way, the light transmitting layer 5 and the adhesive layer 3 of the optical semiconductor device 1A are formed.

  Here, the light-transmitting substrate 18 and the light-emitting layer 12 are bonded together by supplying a silicone resin onto the light-transmitting substrate 18 by a spray method, and then bonding after alignment, so that the light-emitting substrate in a bonded state is obtained. The material 12A and the translucent substrate 18 are put in an oven, and are cured and bonded. The silicone resin can be cured, for example, by heating at 150 ° C. for 1 hour.

  Next, as shown in FIG. 15C, the Ni / Au layer 21 is formed on the Cu electrode of the plating layer 16 by electroless plating. Thereby, the metal layers 11a and 11b of the optical semiconductor device 1A are formed. At the time of electroless plating of Ni, for example, degreasing is performed by a treatment for 3 minutes with a weakly defatted degreasing solution, washing with water is performed for 1 minute with running water, and the temperature is adjusted to 70 ° C. after pickling After the wafer is immersed in the nickel-phosphorous plating solution, the wafer is washed with water, whereby the Ni layer is formed. Further, in the electroless plating of Au, the wafer is immersed in an electroless gold plating solution adjusted to 70 ° C., and then washed with water and dried, whereby the surface of the Cu electrode is plated.

Finally, as shown in FIG. 15D, dicing is performed by a dicer, whereby a plurality of optical semiconductor devices 1A are cut out, and the optical semiconductor device 1A according to the first embodiment is obtained. Note that, in the manufacturing process of the optical semiconductor device 1H according to the eighth embodiment, the same process as described above is used, and the optical semiconductor device 1H according to the eighth embodiment is changed by changing the opening size and shape of the resist layer 15. can get.
On the other hand, in the steps shown in FIGS. 15B and 15C, a fluorescent base material to be the fluorescent layer 4 is used instead of the light-transmitting base material 18, and the fluorescent base material is bonded to the light emitting base material 12 </ b> A by the adhesive layer 20. 1D and dicing as shown in FIG. 15D, an optical semiconductor device 1C according to the third embodiment is obtained.

As described above, according to this embodiment, the optical semiconductor devices 1A and 1C according to the first and third embodiments can be manufactured. As a result, the same effects as those of the first and third embodiments can be obtained. Obtainable. Further, by changing the opening size and shape of the resist layer 15, the optical semiconductor device 1H according to the eighth embodiment can be manufactured, and as a result, the same effects as those of the eighth embodiment can be obtained. Furthermore, since a large number of optical semiconductor devices 1A, 1C, 1H can be manufactured in a single manufacturing process, mass production of the optical semiconductor devices 1A, 1C, 1H can be realized. As a result, the optical semiconductor The costs of the devices 1A, 1C, and 1H can be reduced.
(Tenth embodiment)
A tenth embodiment of the present invention will be described with reference to FIG. The present embodiment is a method for manufacturing the optical semiconductor device 1B according to the second embodiment. In the description of this embodiment, the same parts as those described in the first to ninth embodiments are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 16 is a process cross-sectional view illustrating a part of the method for manufacturing the optical semiconductor device of this embodiment.
The steps up to the step shown in FIG. 16A can be the same as those described above with reference to FIGS. 13A to 15A.
Then, as described above with reference to FIG. 15A, the laser is irradiated between the substrate 11 and the light emitting layer 12, and the light emitting base material 12 </ b> A is lifted off from the substrate 11.

Next, as illustrated in FIG. 16A, the light-transmitting substrate 42 is formed on the surface of the light-emitting substrate 12 </ b> A formed by lift-off on the light-emitting layer 12 side. The translucent substrate 42 can be formed, for example, by applying liquid glass by a method such as spin coating and curing. The liquid glass can be supplied by a spray method in addition to spin coating, and the supply method is not limited. The glass layer can be cured, for example, by heating at 200 ° C. for 1 hour. The film forming material for the light transmissive layer 42 can be appropriately selected depending on the application in addition to liquid glass.
Alternatively, a material such as silicon oxide may be deposited by a method such as sputtering or CVD (Chemical Vapor Deposition).

  Alternatively, it can be formed by applying a resin material such as a silicone resin on the light emitting substrate 12A by spin coating or the like and then putting it in an oven or curing it with UV (ultraviolet light). As a silicone resin, what hardens | cures by heating for 1 hour at 150 degreeC, for example is used. In order to form the transparent base material 42 having a uniform thickness, after a silicone resin is supplied onto the light emitting base material 12A, a spacer is formed, and a jig having a highly releasable fluorine process is attached to the surface. Combined and cured. Thereby, it is possible to form a silicone resin film having a uniform thickness while suppressing the curvature of the surface due to the surface tension of the resin.

Next, as shown in FIG. 16B, a Ni / Au layer 43 is formed on the Cu electrode of the plating layer 16 by an electroless plating method. Thereby, the metal layers 11a and 11b of the optical semiconductor device 1B are formed. In the electroless plating of Ni and the electroless plating of Au, the same plating as in the process of forming the Ni / Au layer 21 according to the ninth embodiment is performed.
Finally, as shown in FIG. 16C, dicing is performed by a dicer, whereby a plurality of optical semiconductor devices 1B are cut out, and the optical semiconductor device 1B according to the second embodiment is obtained.

As described above, according to this embodiment, the optical semiconductor device 1B according to the second embodiment can be manufactured, and as a result, the same effects as those of the second embodiment can be obtained. Furthermore, since a large number of optical semiconductor devices 1B can be manufactured in a single manufacturing process, mass production of the optical semiconductor device 1B can be realized, and as a result, the cost of the optical semiconductor device 1B can be suppressed. it can.
(Eleventh embodiment)
An eleventh embodiment of the present invention will be described with reference to FIG. In the present embodiment, a method for manufacturing an optical semiconductor device 1D according to the fourth embodiment will be described. About this embodiment, the same part as the part demonstrated regarding the 1st thru | or 10th embodiment is attached | subjected with the same code | symbol, and the description is abbreviate | omitted.

FIG. 17 is a process cross-sectional view illustrating a part of the method for manufacturing the optical semiconductor device of this embodiment.
The manufacturing process according to the present embodiment includes the same processes as those of the ninth embodiment from the process of forming the light emitting layer 12 shown in FIG. 13A to the lift-off process shown in FIG.

  After the lift-off process, as shown in FIG. 17A, the fluorescent layer 41 is formed on the surface of the light emitting substrate 12A on the light emitting layer 12 side. The fluorescent layer 41 is formed using a silicone resin mixed with phosphor particles, liquid glass, or the like. Thereby, the fluorescent layer 4 of the optical semiconductor device 1D is formed.

  Here, the phosphor particles and the silicone resin (or liquid glass or the like) are uniformly mixed by, for example, a self-revolving mixing device, and then supplied by spin coating on the light emitting substrate 12A. It can be formed by curing. As a silicone resin, what hardens | cures by heating for 1 hour at 150 degreeC, for example is used. In order to form the fluorescent layer 4 having a uniform thickness, after a silicone resin is supplied onto the light emitting substrate 12A, a spacer is formed, and a jig having a highly peelable fluorine process is bonded to the surface. And cured. Thereby, it is possible to form a silicone resin film having a uniform thickness while suppressing the curvature of the surface due to the surface tension of the resin.

Alternatively, the fluorescent layer 41 can be formed on the light emitting substrate 12A by sputtering. At this time, the fluorescent layer 41 can be stacked by performing sputtering a plurality of times, and the optical semiconductor device 1D according to the fourth embodiment can be manufactured. The fluorescent layer 41 can also be formed using a CVD apparatus.
When the phosphor material is deposited by sputtering or CVD, the phosphor layer 41 containing a high concentration phosphor can be formed.

Next, as shown in FIG. 17B, a Ni / Au layer 43 is formed on the Cu electrode of the plating layer 16 by an electroless plating method. Thereby, the metal layers 11a and 11b of the optical semiconductor device 1D are formed. In the electroless plating of Ni and the electroless plating of Au, the same plating as in the process of forming the Ni / Au layer 21 according to the ninth embodiment is performed.
Finally, as shown in FIG. 17C, dicing is performed by a dicer, whereby a plurality of optical semiconductor devices 1D are cut out, and the optical semiconductor device 1D according to the fourth embodiment is obtained.

As described above, according to the present embodiment, the optical semiconductor device 1D according to the fourth embodiment can be manufactured, and as a result, the same effects as those of the fourth embodiment can be obtained. Further, since a large number of optical semiconductor devices 1D can be manufactured in a single manufacturing process, mass production of the optical semiconductor device 1D can be realized, and as a result, the cost of the optical semiconductor device 1D can be suppressed. it can.
(Twelfth embodiment)
A twelfth embodiment of the present invention will be described with reference to FIG. The present embodiment is a method for manufacturing the optical semiconductor device 1E according to the fifth embodiment. In the description of this embodiment, the same parts as those described in the first to eleventh embodiments are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 18 is a process cross-sectional view illustrating a part of the method for manufacturing the optical semiconductor device of this embodiment.
The processes up to the process shown in FIG. 18A can be the same as those described above with reference to FIGS. 13A to 15D.
Then, as shown in FIG. 18A, a laser is irradiated between the substrate 11 and the light emitting layer 12, and the light emitting layer 12 is lifted off from the substrate 11.

  Next, as shown in FIG. 18B, the light emitting substrate 12 </ b> A formed by lift-off emits light from the light transmitting substrate 18 such as an optical glass wafer provided with the fluorescent layer 19 through the adhesive layer 20. Affixed to layer 2. In another step, a fluorescent substrate is formed, that is, a silicone resin layer or the like in which phosphor particles are mixed on the transparent substrate 18 made of a light-transmitting inorganic or organic material is formed as the fluorescent layer 19. Then, a silicone resin layer is formed as an adhesive layer 20 on the translucent substrate 18. In this way, the fluorescent layer 4, the light transmitting layer 5, and the adhesive layer 3 of the optical semiconductor device 1E are formed.

  Here, the phosphor particles and the silicone resin are uniformly mixed by, for example, a self-revolving mixing device, and then supplied by spin coating on the translucent substrate 18, and then put into an oven and cured. Can be formed. As a silicone resin, what hardens | cures by heating for 1 hour at 150 degreeC, for example is used. In order to form the fluorescent layer 4 having a uniform thickness, after a silicone resin is supplied onto the translucent substrate 18, a spacer is formed, and a jig having a highly releasable fluorine process is bonded to the surface. And cured. Thereby, it is possible to form a silicone resin film having a uniform thickness while suppressing the curvature of the surface due to the surface tension of the resin.

  In addition, the light-transmitting substrate 18 on which the fluorescent layer 19 is formed and the light-emitting layer 12 are bonded by supplying a silicone resin onto the light-transmitting substrate 18 by a spray method, and then bonding after alignment. The light emitting base material 12A and the light transmitting base material 18 in the combined state are put into an oven, and are cured and bonded. The silicone resin can be cured, for example, by heating at 150 ° C. for 1 hour.

Next, as shown in FIG. 18C, the Ni / Au layer 21 is formed. Thereby, the metal layers 11a and 11b of the optical semiconductor device 1A are formed.
Finally, as shown in FIG. 18D, dicing is performed by a dicer, whereby a plurality of optical semiconductor devices 1E are cut out, and the optical semiconductor device 1E according to the fifth embodiment is obtained.

As described above, according to this embodiment, the optical semiconductor device 1E according to the fifth embodiment can be manufactured, and as a result, the same effect as that of the fifth embodiment can be obtained. Note that, by changing the opening size and shape of the resist layer 15, the optical semiconductor device 1H according to the eighth embodiment can be manufactured, and as a result, the same effect as in the eighth embodiment can be obtained. it can. Furthermore, since a large number of optical semiconductor devices 1E and 1H can be manufactured in a single manufacturing process, mass production of the optical semiconductor devices 1E and 1H can be realized. As a result, the optical semiconductor devices 1E and 1H can be realized. Costs can be reduced.
(Thirteenth embodiment)
A thirteenth embodiment of the present invention will be described with reference to FIG. The present embodiment is a method for manufacturing the optical semiconductor device 1F according to the sixth embodiment. In the description of this embodiment, the same parts as those described in the first to twelfth embodiments are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 19 is a process cross-sectional view illustrating a part of the method for manufacturing the optical semiconductor device of this embodiment.
The steps up to the step shown in FIG. 19A can be the same as those described above with reference to FIGS. 13A to 15A.
Then, as described above with reference to FIG. 15A, the laser is irradiated between the substrate 11 and the light emitting layer 12, and the light emitting base material 12 </ b> A is lifted off from the substrate 11.

Next, as illustrated in FIG. 19A, the light-transmitting substrate 42 is formed on the surface on the light-emitting layer 12 side of the light-emitting substrate 12 </ b> A formed by lift-off. The translucent substrate 42 can be formed, for example, by applying liquid glass by a method such as spin coating and curing. The liquid glass can be supplied by a spray method in addition to spin coating, and the supply method is not limited. The glass layer can be cured, for example, by heating at 200 ° C. for 1 hour. The film forming material for the light transmissive layer 42 can be appropriately selected depending on the application in addition to liquid glass.
Alternatively, a material such as silicon oxide may be deposited by a method such as sputtering or CVD (Chemical Vapor Deposition).

  Alternatively, it can be formed by applying a resin material such as a silicone resin on the light emitting substrate 12A by spin coating or the like and then putting it in an oven or curing it with UV (ultraviolet light). As a silicone resin, what hardens | cures by heating for 1 hour at 150 degreeC, for example is used. In order to form the transparent base material 42 having a uniform thickness, after a silicone resin is supplied onto the light emitting base material 12A, a spacer is formed, and a jig having a highly releasable fluorine process is attached to the surface. Combined and cured. Thereby, it is possible to form a silicone resin film having a uniform thickness while suppressing the curvature of the surface due to the surface tension of the resin.

  Next, as shown in FIG. 19B, the fluorescent layer 41 is formed on the translucent substrate 42. The fluorescent layer 41 is formed using a silicone resin mixed with phosphor particles, liquid glass, or the like. Thereby, the fluorescent layer 4 of the optical semiconductor device 1F is formed.

  Here, the phosphor particles and the silicone resin (or liquid glass or the like) are uniformly mixed by, for example, a self-revolving mixing device, and then supplied onto the light-transmitting substrate 42 by spin coating, and then the oven And can be cured and formed. As a silicone resin, what hardens | cures by heating for 1 hour at 150 degreeC, for example is used. In order to form the fluorescent layer 4 having a uniform thickness, after a silicone resin is supplied onto the translucent substrate 42, a spacer is formed, and a jig whose surface is subjected to fluorine processing with high peelability is provided. Laminated and cured. Thereby, it is possible to form a silicone resin film having a uniform thickness while suppressing the curvature of the surface due to the surface tension of the resin.

  Alternatively, the fluorescent layer 41 can be formed on the translucent substrate 42 by sputtering. At this time, the fluorescent layer 41 can be laminated by performing sputtering a plurality of times. The fluorescent layer 41 can also be formed using a CVD apparatus. When the phosphor material is deposited by sputtering or CVD, the phosphor layer 41 containing a high concentration phosphor can be formed.

  Next, as shown in FIG. 19C, the Ni / Au layer 43 is formed on the Cu electrode of the plating layer 16 by an electroless plating method. Thereby, the metal layers 11a and 11b of the optical semiconductor device 1F are formed. In the electroless plating of Ni and the electroless plating of Au, the same plating as in the process of forming the Ni / Au layer 21 according to the ninth embodiment is performed.

  Finally, as shown in FIG. 19D, dicing is performed by a dicer, whereby a plurality of optical semiconductor devices 1F are cut out, and the optical semiconductor device 1F according to the sixth embodiment is obtained.

As described above, according to the present embodiment, the optical semiconductor device 1F according to the sixth embodiment can be manufactured, and as a result, the same effects as in the sixth embodiment can be obtained. Furthermore, since a large number of optical semiconductor devices 1F can be manufactured in a single manufacturing process, mass production of the optical semiconductor device 1F can be realized, and as a result, the cost of the optical semiconductor device 1F can be suppressed. it can.
(Fourteenth embodiment)
A fourteenth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a method for manufacturing an optical semiconductor device 1G according to the seventh embodiment will be described. Note that in the fourteenth embodiment, the same portions as those described in the first to thirteenth embodiments are denoted by the same reference numerals, and description thereof is omitted.

FIG. 20 is a process cross-sectional view illustrating a part of the method for manufacturing the optical semiconductor device of this embodiment.
The manufacturing process according to the present embodiment includes the same processes as those of the ninth embodiment from the film forming process of the light emitting layer 12 shown in FIG. 13A to the bonding process shown in FIG. ing.

  After the bonding step, as shown in FIG. 20A, a contact layer 31 such as a Ni / Au layer is formed on the Cu electrode of the plating layer 16 by an electroless plating method. In the electroless plating of Ni and the electroless plating of Au, the same plating as in the process of forming the Ni / Au layer 21 according to the sixth embodiment is performed.

  Next, as shown in FIG. 20B, a Sn-3.0Ag-0.5Cu solder paste 32 is applied onto the contact layer 31 by a printing method. The method for applying the solder paste 32 is not limited to the printing method.

  Thereafter, as shown in FIG. 20C, the translucent substrate 18 of the wafer is passed through a reflow furnace, the solder is remelted, and the flux residue is washed, so that the solder bumps 33 are formed on the plating layer 16. It is formed on the Cu electrode. Thereby, the metal layers 11a and 11b of the optical semiconductor device 1B are formed.

  Finally, as shown in FIG. 20D, dicing is performed by a dicer, whereby a plurality of optical semiconductor devices 1G are cut out, and the optical semiconductor device 1G according to the seventh embodiment is obtained.

As described above, according to the present embodiment, the optical semiconductor device 1G according to the seventh embodiment can be manufactured, and as a result, the same effects as those of the seventh embodiment can be obtained. Furthermore, since a large number of optical semiconductor devices 1G can be manufactured in a single manufacturing process, mass production of the optical semiconductor device 1G can be realized, and as a result, the cost of the optical semiconductor device 1G can be suppressed. it can.
(Other embodiments)
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, some components may be deleted from all the components shown in the above-described embodiment. Furthermore, you may combine the component covering different embodiment suitably. Moreover, in the above-mentioned embodiment, although various numerical values are mentioned, those numerical values are illustrations and are not limited.

  DESCRIPTION OF SYMBOLS 1A-1G ... Optical semiconductor device, 2 ... Light emitting layer, 4 ... Fluorescent layer, 5 ... Translucent layer, 7a ... 1st electrode, 7b ... 2nd electrode, 8a ... 1st metal post, 8b ... 2nd metal post, DESCRIPTION OF SYMBOLS 10 ... Sealing layer, 11 ... Substrate, 11a ... 1st metal layer, 11b ... 2nd metal layer, 12 ... Light emitting layer, 12A ... Light emitting base material, 14 ... Conductive film (seed layer), 15 ... Sacrificial layer ( Resist layer), 16 ... plating layer, 17 ... sealing layer (thermosetting resin layer), 18 ... translucent base material, 19, 41 ... fluorescent layer, 21, 33, 43 ... metal layer, 42 ... translucent layer, M1 ... 1st main surface, M2 ... 2nd main surface

  Embodiments described herein relate generally to an optical semiconductor device and a method for manufacturing the same.

  Embodiments of the present invention provide an optical semiconductor device that can be mass-produced at low cost and can be downsized to the same extent as a semiconductor light emitting element, and a method for manufacturing the same.

  According to the embodiment, the semiconductor stacked body is epitaxially grown on the substrate and then separated from the substrate, and includes a first main surface and a second main surface that is an opposite surface of the first main surface. A light emitting layer, a first electrode and a second electrode formed on the second main surface of the light emitting layer, provided on the first main surface, have translucency, and have a refractive index of 1 to 2. A light-transmitting layer made of an inorganic material, and a fluorescent layer provided on the light-transmitting layer and including a phosphor that absorbs light emitted from the light-emitting layer and emits light of different wavelengths The side surface of the light-transmitting layer has a portion that is not covered with the fluorescent layer, and part of the light emitted from the light-emitting layer propagates through the light-transmitting layer and converts the wavelength in the fluorescent layer. And the other part of the light emitted from the light emitting layer propagates through the light transmissive layer and before the light transmissive layer. An optical semiconductor device is provided, characterized in that it is released from the side surface to the outside.

Claims (1)

A light emitting layer including a semiconductor stacked body that is epitaxially grown on the substrate and then separated from the substrate, and having a first main surface and a second main surface opposite to the first main surface;
A first electrode and a second electrode formed on the second main surface of the light emitting layer;
A translucent layer provided on the first main surface;
A fluorescent layer that is provided on the light-transmitting layer and includes a phosphor that absorbs light emitted from the light emitting layer and emits light of different wavelengths;
A first metal post provided on the first electrode;
A second metal post provided on the second electrode;
Provided on the second main surface and made of a light shielding material with respect to light emitted from the light emitting layer, exposing an end portion of the first metal post and an end portion of the second metal post. Sealing the first metal post and the second metal post, and covering a side surface of the light emitting layer;
With
The side surface of the translucent layer has a portion that is not covered by the fluorescent layer and the sealing layer,
A part of the light emitted from the light emitting layer propagates through the light transmitting layer, is wavelength-converted in the fluorescent layer and can be emitted to the outside, and another part of the light emitted from the light emitting layer is the light transmitting light. An optical semiconductor device characterized in that it can propagate through a layer and be emitted to the outside from the side surface of the translucent layer.

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