TW201834263A - Light-emitting element and method for manufacturing same - Google Patents

Abstract

The present invention provides a light-emitting element comprising: a window layer-cum-support substrate; and a plurality of light-emitting units that are provided on the window layer-cum-support substrate and have mutually different light emission wavelengths, wherein each of the plurality of light-emitting units: has a structure in which a second-conductivity-type second semiconductor layer, an active layer, and a first-conductivity-type first semiconductor layer are formed in the order given; includes a removed section in which the first semiconductor layer or the second semiconductor layer and the active layer have been removed, and a non-removed section that is outside of the removed section; and include a first ohmic electrode that is provided to the non-removed section and a second ohmic electrode that is provided to the removed section.

Description

Light-emitting element and method of manufacturing same

The present invention relates to a light-emitting element and a method of manufacturing the same.

In AR (Augmented Reality) and HMD (Head Mounted Display), an ultra-small display having a long side of about 1 to 2 cm square is required, and a display having a high brightness is also required.

When a Full HD type display with a long side of about 1 to 2 cm is used, since 1920 × 1080 pixel pixels are required, the size of 1 pixel must be 5.2 μm to 10.4 μm.

In such an ultra-small illuminator, a high luminance is required per unit area of one element, and an organic electroluminescence display such as LCD or Patent Document 2 of Patent Document 1 is also preferable. .

Furthermore, since a high degree of process precision is required, it is more appropriate to select a material that can be applied to a semiconductor process. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2013-210588 (Patent Document 2) JP-A-2013-037021

[Problems to be Solved by the Invention] The pixel-sized black-and-white display as described above, as disclosed in CEA-LETI (France), can be realized by using a wafer that can be applied to a semiconductor process.

However, the technology disclosed by CEA-LETI is monochrome, and there is no proposal for multi-color technology. This is because the InGaN-based epitaxial wafer that emits blue to green light and the AlGaInP-based material that emits yellow to red light are used to form an optimum temperature band for the wafer (InGaN is 800 to 1000 ° C, and AlGaInP is 500 to 700 ° C) and substrates (InGaN-based sapphire substrates, AlGaInP-based GaAs substrates) are extremely difficult to form on a single wafer by epitaxial growth.

Although it is technically possible to complete the display by graining and transferring very small light-emitting elements to the drive substrate, if it is desired to achieve, for example, two-color illumination in a 1920×1080 pixel display, even at 0.2 sec/ The transfer of the production distance also requires 240 days of manufacturing time, which is not pragmatic.

In order to realize a narrow-pitch (small-size) light-emitting element array at a high density, it is desirable to realize a wafer having a function of different light-emitting wavelengths on one wafer, and then to form a narrow-pitch component array through a semiconductor process, thereby completing monitor.

In view of the above problems, an object of the present invention is to provide a light-emitting element in which a plurality of light-emitting portions having different light-emitting wavelengths are formed in the same light-emitting element and a light-emitting device suitable for a narrow pitch, and a method of manufacturing such a light-emitting element. An array of components. [Technical means to solve the problem]

In order to achieve the above problems, the present invention provides a light-emitting element including a window layer and a support substrate, and a plurality of light-emitting portions disposed on the window layer-supporting substrate and having different emission wavelengths, wherein the plurality of light-emitting portions have a plurality of light-emitting portions. a structure formed by the order of the second semiconductor layer of the second conductivity type, the active layer, and the first semiconductor layer of the first conductivity type, and having the first semiconductor layer or the second semiconductor layer and the active layer removed The removed portion and the non-removed portion other than the removed portion further include a first ohmic electrode provided in the non-removed portion and a second ohmic electrode provided in the removed portion.

In the case of such a light-emitting element, a plurality of light-emitting portions having different light-emitting wavelengths are formed on the same light-emitting element, and are suitable for light-emitting elements of a light-emitting element array having a narrow pitch.

Further, one of the plurality of light-emitting elements is formed of an epitaxial layer directly formed on the window layer and the support substrate, and the other light-emitting portions are preferably bonded to the epitaxial layer.

In the case of such a light-emitting element, light of a plurality of wavelengths can be prevented from interfering with each other, and can be radiated to the outside while maintaining high luminance.

Further, it is preferable that a benzocyclobutene film or a SiO ₂ film is provided between the epitaxial layer directly formed on the window layer supporting substrate and the light emitting portion bonded to the epitaxial layer.

In the case of such a light-emitting element, the bonding between the epitaxial layer directly formed on the window layer and the supporting substrate and the light-emitting portion bonded to the epitaxial layer is mechanically stronger.

In addition, the plurality of light-emitting portions may be a light-emitting portion including a blue-green-colored InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material.

In this case, the light-emitting element of the present invention can be, for example, a light-emitting element having a plurality of light-emitting portions having different emission wavelengths such as a cyan system or a red-yellow color.

Furthermore, the present invention provides a method of fabricating a light-emitting device, comprising the steps of: preparing a first epitaxial substrate and a second epitaxial substrate, wherein the first epitaxial substrate has a light emitting a first wavelength on the first substrate The epitaxial layer, the second epitaxial substrate has an epitaxial layer emitting light of a second wavelength on the second substrate; an epitaxial layer bonded to the first epitaxial substrate and a protrusion of the second epitaxial substrate a seed layer; and removing the first substrate or the second substrate from the bonded epitaxial substrate.

In such a manufacturing method, since the light-emitting portions of two or more kinds of emission wavelengths are individually formed and then joined, it is possible to grow the respective light-emitting portions under the most suitable crystal growth conditions, thereby obtaining the light emission for each of the light-emitting portions. A light-emitting layer (light-emitting element region) having a high efficiency in wavelength. In this way, a plurality of light-emitting portions having different light-emitting wavelengths can be easily produced, and light beams of a plurality of wavelengths can be prevented from interfering with each other, and the light-emitting elements can be radiated to the outside while maintaining high luminance.

Further, an InGaN-based material may be used as the epitaxial layer that emits light of a first wavelength, and an AlGaInP-based material is used as the epitaxial layer that emits light of a second wavelength.

As described above, according to the production method of the present invention, it is possible to easily produce a light-emitting element having a plurality of light-emitting portions having a light-emitting wavelength of a cyan-based or red-yellow color.

Furthermore, the epitaxial layer emitting light of a first wavelength and the epitaxial layer emitting light of a second wavelength to form a second semiconductor layer having an second conductivity type, an active layer, and a first conductivity type The epitaxial layer of the structure formed by the order of the first semiconductor layers is preferred.

As described above, the method of the present invention is applicable to a method of forming a light-emitting portion having a double hetero structure.

Furthermore, it is preferable to further include a step of the epitaxial layer emitting light of a first wavelength and emitting light of a second wavelength after the step of removing the first substrate or the second substrate Each of the epitaxial layers is formed with a removed portion that removes the first semiconductor layer or the second semiconductor layer and the active layer, and a non-removed portion other than the removed portion, and a first ohmic electrode is disposed in the non-removed portion, and A second ohmic electrode is disposed in the removal portion.

According to the manufacturing method of the present invention, an ohmic electrode can be provided in the light-emitting portion according to such a procedure.

Furthermore, before the step of bonding the epitaxial layer of the first epitaxial substrate and the epitaxial layer of the second epitaxial substrate, the epitaxial layer on the first epitaxial substrate and the second epitaxial substrate a benzocyclobutene film is formed on at least one of the epitaxial layers, and then the epitaxial layer of the first epitaxial substrate and the epitaxial layer of the second epitaxial substrate are bonded through the benzocyclobutene film The layer is better.

Furthermore, before the step of bonding the epitaxial layer of the first epitaxial substrate and the epitaxial layer of the second epitaxial substrate, the epitaxial layer on the first epitaxial substrate and the second epitaxial substrate An SiO ₂ film is formed on at least one of the epitaxial layers, and then the epitaxial layer of the first epitaxial substrate and the epitaxial layer of the second epitaxial substrate are bonded through the SiO ₂ film.

By bonding the epitaxial layer of the first epitaxial substrate and the epitaxial layer of the second epitaxial substrate through a benzocyclobutene film or a SiO ₂ film, the epitaxial layers can be mechanically bonded to each other. Stronger.

As described above, in the case of the light-emitting element of the present invention, a plurality of light-emitting portions having different light-emitting wavelengths can be formed on the same light-emitting element, and two or more colors of blue to green and yellow to red can be displayed. And it is possible to prevent the light of a plurality of wavelengths from interfering with each other, and to radiate it to the external light-emitting element while maintaining high luminance. Therefore, in the case of the light-emitting element of the present invention, it is particularly suitable for a light-emitting element array having a narrow pitch. Further, in the method for producing a light-emitting device of the present invention, since the light-emitting portions of the two kinds of light-emitting wavelengths are individually formed and then joined, it is possible to grow the respective light-emitting portions under the most suitable crystal growth conditions, thereby obtaining a pair. Each of the light-emitting wavelengths has a highly efficient light-emitting layer (light-emitting element region). In this way, a plurality of light-emitting portions having different light-emitting wavelengths can be easily manufactured, and light of a plurality of wavelengths can be prevented from interfering with each other, and can be radiated to the outside while maintaining high luminance, and is suitable for narrow pitches. A light-emitting element of an array of light-emitting elements.

As described above, there has been a demand for a light-emitting element in which a plurality of light-emitting portions having different light-emitting wavelengths are formed on the same light-emitting element, and a light-emitting element which is suitable for use in a narrow-pitch light-emitting element array.

The inventors of the present invention have been actively researching and found that the method of forming the light-emitting portions of the two kinds of light-emitting wavelengths separately and then joining them can increase the light-emitting portions under the most suitable crystal growth conditions. The present invention has been completed by easily producing a light-emitting element in which a plurality of light-emitting portions having different light-emitting wavelengths are formed in the same light-emitting element.

That is, the present invention is a light-emitting element comprising a window layer and a supporting substrate, and a plurality of light-emitting portions disposed on the window layer and supporting substrate and having different emission wavelengths, wherein the plurality of light-emitting portions have the second a structure in which the second semiconductor layer of the conductive type, the active layer, and the first semiconductor layer of the first conductivity type are sequentially formed, and has the removal portion of the first semiconductor layer or the second semiconductor layer and the active layer removed And a non-removed portion other than the removed portion, further comprising a first ohmic electrode provided in the non-removed portion and a second ohmic electrode provided in the removed portion.

Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

(First embodiment) A first embodiment of the light-emitting device of the present invention will be described with reference to (h) of Fig. 1 . As shown in (h) of FIG. 1, the light-emitting element 12 in the first embodiment of the present invention is a sapphire substrate 155 including a window layer and a supporting substrate, and is provided on the sapphire substrate 155 and is made of a blue-green color. A light-emitting element of a light-emitting portion composed of an InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material.

A light-emitting portion made of a blue-green InGaN-based material has an N-type cladding layer (second semiconductor layer) 151 composed of Al _s Ga _1-s N (0≦s≦1), and is composed of In _s Ga _{The order} of the active layer 152 composed of _1-s N(0≦s≦1) and the P-type cladding layer (first semiconductor layer) 153 composed of Al _s Ga _1-s N(0≦s≦1) The formed structure has the removal portion 170 in which the P-type cladding layer 153 and the active layer 152 are removed, and the non-removed portion 160 other than the removal portion 170, and is provided in the non-removed portion 160 and the P-type cladding layer 153. A third electrode (first ohmic electrode) 161 that is in contact with each other, and a fourth electrode (second ohmic electrode) 171 that is provided in the removal portion 170 and is in contact with the N-type cladding layer 151.

A light-emitting portion composed of a red-yellow AlGaInP-based material has a P-type cladding composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) a layer (first semiconductor layer) 103, an active layer 102 composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _{1 -x} ) a structure formed by the order of the N-type cladding layer (second semiconductor layer) 101 composed of _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and having an N-type cladding layer 101 and the removal portion 120 from which the active layer 102 is removed, and the non-removed portion 110 other than the removal portion 120, and a first electrode (first ohmic electrode) provided in the non-removed portion 110 and in contact with the N-type cladding layer 101 And a second electrode (second ohmic electrode) 121 provided in the removal portion 120 and in contact with the P-type cladding layer 103. Further, a light-emitting portion made of a red-yellow AlGaInP-based material is bonded to an epitaxial layer made of a blue-green InGaN-based material.

Furthermore, the two light-emitting portions are covered by the insulating layer 115, and the bumps 140 are formed on the first electrode 111, the second electrode 121, the third electrode 161, and the fourth electrode 171.

Next, a method of manufacturing a light-emitting element according to a first embodiment of the present invention will be described with reference to (a) to (h) of Fig. 1 . First, as shown in (a) of FIG. 1, the sapphire substrate 155 is sequentially laminated by Al _s Ga _1-s N (0≦s≦1) by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 151, an active layer 152 composed of In _s Ga _1-s N (0≦s≦1), and Al _s Ga _1-s N (0≦s) ≦ 1) A P-type cladding layer (first semiconductor layer) 153 is formed to form an InGaN-based epitaxial wafer 150 of blue or green light-emitting material. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Further, as shown in (b) of FIG. 1, the GaAs substrate 105 is sequentially laminated by (Al _x Ga _1-x ) _y In _1- by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 101 composed of _y P(0≦x≦1, 0.4≦y≦0.6), from (Al _x Ga _1-x ) _y In _1-y P(0≦x≦ 1,0.4 ≦ y ≦ 0.6) composed of an active layer 102 and a P-type coating layer composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) (First semiconductor layer) 103, an AlGaInP-based epitaxial wafer 100 of red and yellow luminescent material is produced. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Next, as shown in FIG. 1(c), the InGaN-based epitaxial wafer 150 and the AlGaInP-based epitaxial wafer 100 are bonded. At this time, both the AlGaInP-based epitaxial wafer 100 and the InGaN-based epitaxial wafer 150 are immersed in an alkaline solution (aqueous KOH solution or NaOH aqueous solution, etc.) to alkali treat the surface, and then AlGaInP-based epitaxial crystals are formed in a vacuum. The circle 100 is in contact with both of the epitaxial faces of the InGaN-based epitaxial wafer 150 (the P-type cladding layer 103 and the P-type cladding layer 153), and is pressed at a pressure of 500 N or more, and is maintained at 500 ° C or higher. At the same temperature, the bonded wafer 10 to which the two wafers are bonded can be formed.

Further, the thickness of the GaAs substrate of the AlGaInP-based epitaxial wafer 100 may be thinned to a thickness of about 50 to 100 μm by etching or wheel grinding before bonding. By the film processing, the AlGaInP-based epitaxial wafer 100 is easily deformed during bonding, and has an effect of improving the yield after bonding.

Next, as shown in FIG. 1(d), the wafer 11 from which the GaAs substrate 105 of the AlGaInP-based epitaxial wafer 100 is removed is formed by chemical etching. The chemical etching solution preferably has an etch selectivity to the AlGaInP-based material, and is generally removed by an ammonia-containing etchant. At this time, the substrate processed or removed by the film may be a sapphire substrate 155.

Next, as shown in FIG. 1(e), a part of the N-type cladding layer 101 and the active layer 102 is removed from the epitaxial layer made of an AlGaInP-based material to form the removed portion 120 and the non-removed portion 110. . The removal at this time can be performed, for example, by etching through the mask non-removing portion 110. Then, a first electrode (first ohmic electrode) 111 is formed on the N-type cladding layer 101 (non-removed portion 110) of the AlGaInP-based epitaxial wafer 100, and the N-type cladding layer 101 and the active layer are locally etched away. A second electrode (second ohmic electrode) 121 is formed at a portion of the region (the removal portion 120) of 102.

Next, as shown in (f) and (g) of FIG. 1, the P-type cladding layer 153 is formed at a region 130 where the first electrode 111 and the second electrode 121 of the epitaxial layer made of an InGaN-based material are not formed. A part of the active layer 152 is removed to form a removal portion 170 and a non-removed portion 160. The removal at this time can be performed, for example, by a luminescent etching method including a non-removing portion 160 and an AlGaInP-based material, and then performing an ICP etching method using an atmosphere containing a Cl-based gas (Cl ₂ , BCl ₃ , or SiCl ₄ ).

Then, as shown in (g) of FIG. 1 , a third electrode (first ohmic electrode) 161 is formed on a portion (non-removed portion 160) of the P-type cladding layer 153 of the exposed InGaN-based epitaxial wafer 150, and A fourth electrode (second ohmic electrode) 171 is formed at a portion of the region (removed portion 170) where the P-type cladding layer 153 and the active layer 152 are locally etched away.

Next, as shown in (h) of FIG. 1, bumps 140 are formed on the first electrode 111, the second electrode 121, the third electrode 161, and the fourth electrode 171 to fabricate a light-emitting wafer (light-emitting element 12). In addition, the bumps may be formed through the studs or may be formed by plating.

(Second embodiment) A second embodiment of the light-emitting device of the present invention will be described with reference to (h) of Fig. 2 . As shown in (h) of FIG. 2, the light-emitting element 22 in the second embodiment of the present invention is a sapphire substrate 255 including a window layer and a supporting substrate, and a blue-green color system provided on the sapphire substrate 255. A light-emitting element of a light-emitting portion composed of an InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material.

A light-emitting portion made of a blue-green InGaN-based material has an N-type cladding layer (second semiconductor layer) 251 composed of Al _s Ga _1-s N (0≦s≦1), and is composed of In _s Ga _{The order} of the active layer 252 composed of _1-s N(0≦s≦1) and the P-type cladding layer (first semiconductor layer) 253 composed of Al _s Ga _1-s N(0≦s≦1) The formed structure has the removal portion 270 in which the P-type cladding layer 253 and the active layer 252 are removed, and the non-removed portion 260 other than the removal portion 270, and is provided in the non-removed portion 260 and the P-type cladding layer 253. A third electrode (first ohmic electrode) 261 that is in contact with each other, and a fourth electrode (second ohmic electrode) 271 that is provided in the removal portion 270 and is in contact with the second semiconductor layer 251.

A light-emitting portion composed of a red-yellow AlGaInP-based material has a P-type cladding composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) a layer (first semiconductor layer) 203, an active layer 202 composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _{1 -x} ) a structure formed by the order of the N-type cladding layer (second semiconductor layer) 201 composed of _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and having an N-type cladding layer 201 and the removal portion 220 from which the active layer 202 is removed, and the non-removed portion 210 other than the removal portion 220, further includes a first electrode (first ohmic electrode) provided in the non-removed portion 210 and in contact with the N-type cladding layer 201 And a second electrode (second ohmic electrode) 221 provided in the removal portion 220 and in contact with the P-type cladding layer 203. Further, a light-emitting portion composed of a red-yellow AlGaInP-based material is bonded to an epitaxial layer made of a blue-green InGaN-based material through a BCB film (benzocyclobutene film) 204.

Furthermore, the two light-emitting portions are covered by the insulating layer 215, and the bumps 240 are formed on the first electrode 211, the second electrode 221, the third electrode 261, and the fourth electrode 271.

Next, a method of manufacturing a light-emitting element according to a second embodiment of the present invention will be described with reference to FIGS. 2(a) to 2(h). First, as shown in (a) of FIG. 2, the sapphire substrate 255 is sequentially laminated by Al _s Ga _1-s N (0≦s≦1) by, for example, organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 251, an active layer 252 composed of In _s Ga _1-s N (0≦s≦1), and Al _s Ga _1-s N (0≦s) ≦ 1) A P-type cladding layer (first semiconductor layer) 253 is formed to form an InGaN-based epitaxial wafer 250 of blue or green light-emitting material. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Further, as shown in (b) of FIG. 2, the GaAs substrate 205 is sequentially laminated by (Al _x Ga _1-x ) _y In ₁ by, for example, an organometallic vapor phase epitaxy (MOVPE). N-type cladding layer (second semiconductor layer) 201 composed of _-y P (0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _1-x ) _y In _1-y P(0≦x The active layer 202 composed of ≦1, 0.4≦y≦0.6) and the P-type cladding composed of (Al _x Ga _1-x ) _y In _1-y P(0≦x≦1, 0.4≦y≦0.6) A layer (first semiconductor layer) 203 is used to form an AlGaInP-based epitaxial wafer 200 of red and yellow luminescent materials. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Next, benzocyclobutene (BCB) is applied onto the epitaxial surface (P-type cladding layer 203) of the AlGaInP-based epitaxial wafer 200 at a number of revolutions of 3,000 rpm or more to form a BCB film 204 having a film thickness of about 1 μm. Then, as shown in FIG. 2(c), the BCB coated surface of the AlGaInP-based epitaxial wafer 200 is brought into contact with the epitaxial surface (P-type cladding layer 253) of the InGaN-based epitaxial wafer 250, and is brought into contact with The pressure of 500 N or more is pressed together, and by holding the temperature at 150 ° C or higher, the bonded wafer 20 joining the two wafers can be formed. In addition, the BCB film may be formed only on either the first epitaxial substrate or the second epitaxial substrate, or both.

Further, before the bonding, the thickness of the GaAs substrate of the AlGaInP-based epitaxial wafer 200 may be thinned to about 50 to 100 μm by etching or wheel milling. By the film processing, the AlGaInP-based epitaxial wafer 200 is easily deformed during bonding, and has an effect of improving the yield after bonding.

Next, as shown in (d) of FIG. 2, the wafer 21 of the GaAs substrate 205 from which the AlGaInP-based epitaxial wafer 200 is removed is formed by chemical etching. The chemical etching solution preferably has an etch selectivity to the AlGaInP-based material, and is generally removed by an ammonia-containing etchant. At this time, the substrate processed or removed by the film may be a sapphire substrate 255.

Next, as shown in FIG. 2(e), a portion of the N-type cladding layer 201 and the active layer 202 is removed from the epitaxial layer made of an AlGaInP-based material to form a removed portion 220 and a non-removed portion 210. The removal at this time can be performed, for example, by etching through the mask non-removing portion 210. Then, a first electrode (first ohmic electrode) 211 is formed on the N-type cladding layer 201 (non-removed portion 210) of the AlGaInP-based epitaxial wafer 200, and the N-type cladding layer 201 and the active layer are locally etched away. A second electrode (second ohmic electrode) 221 is formed at a portion of the region (the removal portion 220) of 202.

Next, as shown in (f) and (g) of FIG. 2, in the region 230 where the first electrode 211 and the second electrode 221 of the epitaxial layer made of an InGaN-based material are not formed, the fluorine-containing gas (CF) is contained. _4. ICP etching of the atmosphere of CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , NF ₃ , SF ₄ , SF ₆ ) removes the BCB film 204 to expose the surface of the InGaN-based epitaxial wafer (P-type cladding layer) 253). Then, a part of the P-type cladding layer 253 and the active layer 252 is removed to form a removal portion 270 and a non-removed portion 260. The removal at this time can be performed, for example, by a luminescent etching method including a non-removing portion 260 and an AlGaInP-based material, and then performing an ICP etching method using an atmosphere containing a Cl-based gas (Cl ₂ , BCl ₃ , or SiCl ₄ ).

Next, as shown in (g) of FIG. 2, a third electrode (first ohmic electrode) 261 is formed in a portion (non-removed portion 260) of the P-type cladding layer 253 of the exposed InGaN-based epitaxial wafer 250. And a fourth electrode (second ohmic electrode) 271 is formed at a portion of the region (removed portion 270) where the P-type cladding layer 253 and the active layer 252 are locally etched away.

Next, as shown in (h) of FIG. 2, bumps 240 are formed on the first electrode 211, the second electrode 221, the third electrode 261, and the fourth electrode 271 to form a light-emitting wafer (light-emitting element 22). In addition, the bumps may be formed through the studs or may be formed by plating.

(Third embodiment) A third embodiment of the light-emitting device of the present invention will be described with reference to (h) of Fig. 3. As shown in (h) of FIG. 3, the light-emitting element 32 in the third embodiment of the present invention is a sapphire substrate 355 including a window layer and a supporting substrate, and a blue-green color system provided on the sapphire substrate 355. A light-emitting element of a light-emitting portion composed of an InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material.

The light-emitting portion made of a blue-green InGaN-based material has an N-type cladding layer (second semiconductor layer) 351 composed of Al _s Ga _1-s N (0≦s≦1), and is composed of In _s Ga _{The order} of the active layer 352 composed of _1-s N(0≦s≦1) and the P-type cladding layer (first semiconductor layer) 353 composed of Al _s Ga _1-s N(0≦s≦1) The formed structure, the removal portion 370 having the P-type cladding layer 353 and the active layer 352 removed, and the non-removed portion 360 other than the removal portion 370 are further provided on the non-removed portion 360 and the P-type cladding layer 353 A third electrode (first ohmic electrode) 361 that is in contact with each other, and a fourth electrode (second ohmic electrode) 371 that is provided in the removal portion 370 and is in contact with the N-type cladding layer 351.

A light-emitting portion composed of a red-yellow AlGaInP-based material has a P-type cladding composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) a layer (first semiconductor layer) 303, an active layer 302 composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _{1 -x} ) a structure formed by the order of the N-type cladding layer (second semiconductor layer) 301 composed of _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and having an N-type cladding layer The removal portion 320 in which the active layer 302 is removed and the non-removed portion 310 other than the removal portion 320 further include a first electrode (first ohmic electrode) provided on the non-removed portion 310 and in contact with the N-type cladding layer 301 And a second electrode (second ohmic electrode) 321 provided in the removal portion 320 and in contact with the P-type cladding layer 303. Further, the light-emitting portion made of a red-yellow AlGaInP-based material is bonded to the epitaxial layer made of a blue-green InGaN-based material by transmitting the two SiO ₂ films 306 and 356.

Furthermore, the two light-emitting portions are covered by the insulating layer 315, and the bumps 340 are formed on the first electrode 311, the second electrode 321, the third electrode 361, and the fourth electrode 371.

Next, a method of manufacturing a light-emitting element according to a third embodiment of the present invention will be described with reference to FIGS. 3(a) to 3(h). First, as shown in (a) of FIG. 3, the sapphire substrate 355 is sequentially laminated by Al _s Ga _1-s N (0≦s≦1) by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 351, an active layer 352 composed of In _s Ga _1-s N (0≦s≦1), and Al _s Ga _1-s N (0≦s) ≦ 1) A P-type cladding layer (first semiconductor layer) 353 is formed to form an InGaN-based epitaxial wafer 350 of blue or green light-emitting material. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method. Then, an SiO ₂ film 356 is formed on the P-type cladding layer 353.

Further, as shown in (b) of FIG. 3, the GaAs substrate 305 is sequentially laminated by (Al _x Ga _1-x ) _y In _1- by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 301 composed of _y P(0≦x≦1, 0.4≦y≦0.6), from (Al _x Ga _1-x ) _y In _1-y P(0≦x≦ 1,0.4≦y≦0.6) of the active layer 302 and a P-type coating layer composed of (Al _x Ga _1-x ) _y In _1-y P(0≦x≦1, 0.4≦y≦0.6) (First semiconductor layer) 303, an AlGaInP-based epitaxial wafer 300 of red and yellow luminescent material is produced. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method. Then, an SiO ₂ film 306 is formed on the P-type cladding layer 303. Further, the SiO ₂ film may be formed only in either the first epitaxial substrate or the second epitaxial substrate, or both.

Next, as shown in (c) of FIG. 3, an InGaN-based epitaxial wafer 350 and an AlGaInP-based epitaxial wafer 300 are bonded. At this time, both the AlGaInP-based epitaxial wafer 300 and the InGaN-based epitaxial wafer 350 are immersed in an alkaline solution (aqueous KOH solution or NaOH aqueous solution, etc.) to alkali treat the surface, and then the AlGaInP-based epitaxial wafer 300 is Both of the SiO ₂ films of the InGaN-based epitaxial wafer 350 are contacted in a vacuum, and are pressed at a pressure of 500 N or more, and by holding the temperature at 700 ° C or higher, the bonded wafer 30 for bonding the two wafers can be formed. .

Next, as shown in (d) of FIG. 3, the wafer 31 of the GaAs substrate 305 from which the AlGaInP-based epitaxial wafer 300 is removed by chemical etching is formed. The chemical etching solution preferably has an etch selectivity to the AlGaInP-based material, and is generally removed by an ammonia-containing etchant. At this time, the substrate processed or removed by the film may be a sapphire substrate 355.

Next, as shown in FIG. 3(e), a portion of the N-type cladding layer 301 and the active layer 302 is removed from the epitaxial layer made of an AlGaInP-based material to form a removal portion 320 and a non-removing portion 310. . The removal at this time can be performed, for example, by etching through the mask non-removing portion 310. Then, a first electrode (first ohmic electrode) 311 is formed on the N-type cladding layer 301 (non-removed portion 310) of the AlGaInP-based epitaxial wafer 300, and the N-type cladding layer 301 and the active layer are locally etched away. A second electrode (second ohmic electrode) 321 is formed at a portion of the region (the removal portion 320) of 302.

Next, as shown in (f) and (g) of FIG. 3, in the region 330 where the first electrode 311 and the second electrode 321 of the epitaxial layer made of an InGaN-based material are not formed, the F-containing gas (CF) is contained. _4. ICP etching of the atmosphere of CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , NF ₃ , SF ₄ , SF ₆ ) removes the SiO ₂ films 306 and 356 to expose the surface of the InGaN-based epitaxial wafer (P type) Cover layer 353). Then, a part of the P-type cladding layer 353 and the active layer 352 is removed to form a removal portion 370 and a non-removed portion 360. The removal at this time can be performed, for example, by a luminescent etching method including a non-removing portion 360 and an AlGaInP-based material, and then performing an ICP etching method using an atmosphere containing a Cl-based gas (Cl ₂ , BCl ₃ , or SiCl ₄ ).

Next, as shown in (g) of FIG. 3, a third electrode (first ohmic electrode) is formed on a portion (non-removed portion 360) of the P-type cladding layer 353 of the exposed InGaN-based epitaxial wafer 350. 361, and a fourth electrode (second ohmic electrode) 371 is formed at a portion of the region (removed portion 370) where the P-type cladding layer 353 and the active layer 352 are locally etched away.

Next, as shown in (h) of FIG. 3, bumps 340 are formed on the first electrode 311, the second electrode 321, the third electrode 361, and the fourth electrode 371 to form a light-emitting wafer (light-emitting element 32). In addition, the bumps may be formed through the studs or may be formed by plating.

(Fourth embodiment) A fourth embodiment of the light-emitting device of the present invention will be described with reference to (h) of Fig. 4. As shown in (h) of FIG. 4, the light-emitting element 42 in the fourth embodiment of the present invention is a sapphire substrate 455 including a window layer and a supporting substrate, and a blue-green color system provided on the sapphire substrate 455. A light-emitting element of a light-emitting portion composed of an InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material.

A light-emitting portion made of a blue-green InGaN-based material has an N-type cladding layer (second semiconductor layer) 451 composed of Al _s Ga _1-s N (0≦s≦1), and is composed of In _s Ga _{The order} of the active layer 452 composed of _1-s N(0≦s≦1) and the P-type cladding layer (first semiconductor layer) 453 composed of Al _s Ga _1-s N(0≦s≦1) The formed structure has a removal portion 470 in which the P-type cladding layer 453 and the active layer 452 are removed, and a non-removed portion 460 other than the removal portion 470, and is provided on the non-removed portion 460 and the P-type cladding layer 453. A third electrode (first ohmic electrode) 461 that is in contact with each other, and a fourth electrode (second ohmic electrode) 471 that is provided in the removal portion 470 and is in contact with the N-type cladding layer 451.

A light-emitting portion composed of a red-yellow AlGaInP-based material has a P-type cladding composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) a layer (first semiconductor layer) 403, an active layer 402 composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _{1 -x} ) a structure formed by the order of the N-type cladding layer (second semiconductor layer) 401 composed of _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and having an N-type cladding layer The removal portion 420 from which the active layer 402 is removed and the non-removed portion 410 other than the removal portion 420 further include a first electrode (first ohmic electrode) provided in the non-removed portion 410 and in contact with the N-type cladding layer 401 And a second electrode (second ohmic electrode) 421 provided in the removal portion 420 and in contact with the P-type cladding layer 403. In addition, the light-emitting portion composed of a red-yellow AlGaInP-based material is bonded to an epitaxial layer (N-type cladding layer 451, active layer 452, and P-type) which is formed of a light-emitting portion made of a blue-green-colored InGaN-based material. Above the cover layer 453).

Furthermore, the two light-emitting portions are covered by the insulating layer 415, and the bumps 440 are formed on the first electrode 411, the second electrode 421, the third electrode 461, and the fourth electrode 471.

Next, a method of manufacturing a light-emitting element according to a fourth embodiment of the present invention will be described with reference to FIGS. 4(a) to 4(h). First, as shown in (a) of FIG. 4, the sapphire substrate 455 is sequentially laminated by Al _s Ga _1-s N (0≦s≦1) by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 451, an active layer 452 composed of In _s Ga _1-s N (0≦s≦1), and Al _s Ga _1-s N (0≦s) ≦ 1) A P-type cladding layer (first semiconductor layer) 453 is formed to form an InGaN-based epitaxial wafer 450 of blue or green light-emitting material. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Further, as shown in (b) of FIG. 4, the GaAs substrate 405 is sequentially laminated by (Al _x Ga _1-x ) _y In _1- by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 401 composed of _y P(0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _1-x ) _y In _1-y P(0≦x≦ 1,0.4≦y≦0.6) of the active layer 402 and a P-type coating layer composed of (Al _x Ga _1-x ) _y In _1-y P(0≦x≦1, 0.4≦y≦0.6) (First semiconductor layer) 403, an AlGaInP-based epitaxial wafer 400 of red and yellow luminescent material is produced. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Next, as shown in FIG. 4(c), the InGaN-based epitaxial wafer 450 and the AlGaInP-based epitaxial wafer 400 are bonded. At this time, both the AlGaInP-based epitaxial wafer 400 and the InGaN-based epitaxial wafer 450 are immersed in an alkaline solution (aqueous KOH solution or NaOH aqueous solution, etc.) to alkali treat the surface, and then AlGaInP-based epitaxial crystals are formed in a vacuum. The circle 400 is in contact with both of the epitaxial faces of the InGaN-based epitaxial wafer 450 (the P-type cladding layer 403 and the P-type cladding layer 453), and is pressed at a pressure of 500 N or more, and is maintained at 500 ° C or higher. At a temperature, a bonded wafer 40 joining the two wafers can be formed.

Further, before the bonding, the thickness of the GaAs substrate of the AlGaInP-based epitaxial wafer 400 may be thinned to about 50 to 100 μm by etching or wheel milling. By the film processing, the AlGaInP-based epitaxial wafer 400 is easily deformed during bonding, and has an effect of improving the yield after bonding.

Next, as shown in (d) of FIG. 4, the wafer 41 of the GaAs substrate 405 from which the AlGaInP-based epitaxial wafer 400 is removed by chemical etching is formed. The chemical etching solution preferably has an etch selectivity to the AlGaInP-based material, and is generally removed by an ammonia-containing etchant. At this time, the substrate processed or removed by the film may be a sapphire substrate 455.

Next, as shown in (e) of FIG. 4, a first electrode (first ohmic electrode) 411 is formed on the N-type cladding layer 401 (non-removed portion 410) of the AlGaInP-based epitaxial wafer 400, and is removed. The portion 420 is formed in a shape of a hole or a groove having a depth of the P-type cladding layer 403 (that is, a removal portion excluding the N-type cladding layer 401 and the active layer 402), and is formed at the bottom of the removal portion 420. A second electrode (second ohmic electrode) 421 that is in contact with the type cladding layer 403.

Next, as shown in (f) of FIG. 4, a portion of the region 430 where the first electrode 411 and the second electrode 421 are not formed is removed at the epitaxial layer made of an AlGaInP-based material. The removal of the region 430 exposes the surface (P-type cladding layer 453) of the InGaN-based epitaxial wafer by an ICP etching method using an atmosphere containing a Cl-based gas (Cl ₂ , BCl ₃ , or SiCl ₄ ).

Next, as shown in (g) of FIG. 4, a third electrode (first ohmic electrode) 461 is formed on a portion (non-removed portion 460) of the P-type cladding layer 453 of the exposed InGaN-based epitaxial wafer 450, and The removal portion 470 is formed in a shape of a hole or a groove having a depth of the N-type cladding layer 451 (that is, a removal portion from which the P-type cladding layer 453 and the active layer 452 are removed), and is formed at the bottom of the removal portion 470. A fourth electrode (second ohmic electrode) 471 that is in contact with the N-type cladding layer 451.

Next, as shown in (h) of FIG. 4, bumps 440 are formed on the first electrode 411, the second electrode 421, the third electrode 461, and the fourth electrode 471 to fabricate a light-emitting wafer (light-emitting element 42). In addition, the bumps may be formed through the studs or may be formed by plating.

(Fifth Embodiment) A fifth embodiment of the light-emitting device of the present invention will be described with reference to (h) of Fig. 5. As shown in (h) of FIG. 5, the light-emitting element 52 in the fifth embodiment of the present invention is a sapphire substrate 555 including a window layer and a supporting substrate, and a blue-green color system provided on the sapphire substrate 555. A light-emitting element of a light-emitting portion composed of an InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material.

A light-emitting portion made of a blue-green InGaN-based material has an N-type cladding layer (second semiconductor layer) 551 composed of Al _s Ga _1-s N (0≦s≦1), and is composed of In _s Ga _{The order} of the active layer 552 composed of _1-s N(0≦s≦1) and the P-type cladding layer (first semiconductor layer) 553 composed of Al _s Ga _1-s N(0≦s≦1) The formed structure has a removal portion 570 in which the P-type cladding layer 553 and the active layer 552 are removed, and a non-removed portion 560 other than the removal portion 570, and is provided on the non-removed portion 560 and the P-type cladding layer 553. A third electrode (first ohmic electrode) 561 that is in contact with each other, and a fourth electrode (second ohmic electrode) 571 that is provided in the removal portion 570 and is in contact with the N-type cladding layer 551.

A light-emitting portion composed of a red-yellow AlGaInP-based material has a P-type cladding composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) a layer (first semiconductor layer) 503, an active layer 502 composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _{1 -x} ) a structure formed by the order of the N-type cladding layer (second semiconductor layer) 501 composed of _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and having an N-type cladding layer 501 and the removal portion 520 from which the active layer 502 is removed, and the non-removed portion 510 other than the removal portion 520, and a first electrode (first ohmic electrode) provided in the non-removed portion 510 and in contact with the N-type cladding layer 501 And a second electrode (second ohmic electrode) 521 provided in the removal portion 520 and in contact with the P-type cladding layer 503. Further, the light-emitting portion composed of a red-yellow AlGaInP-based material is bonded to an epitaxial layer (N-type) constituting a light-emitting portion composed of a blue-green-type InGaN-based material through a BCB film (benzocyclobutene film) 504. Above the cladding layer 551, the active layer 552 and the P-type cladding layer 553).

Furthermore, the two light-emitting portions are covered by the insulating layer 515, and the bumps 540 are formed on the first electrode 511, the second electrode 521, the third electrode 561, and the fourth electrode 571.

Next, a method of manufacturing a light-emitting element according to a fifth embodiment of the present invention will be described with reference to (a) to (h) of Fig. 5. First, as shown in (a) of FIG. 5, the sapphire substrate 555 is sequentially laminated by Al _s Ga _1-s N (0≦s≦1) by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 551, an active layer 552 composed of In _s Ga _1-s N (0≦s≦1), and Al _s Ga _1-s N (0≦s) ≦ 1) A P-type cladding layer (first semiconductor layer) 553 is formed to form an InGaN-based epitaxial wafer 550 of blue or green light-emitting material. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Further, as shown in (b) of FIG. 5, the GaAs substrate 505 is sequentially laminated by (Al _x Ga _1-x ) _y In _1- by, for example, an organometallic vapor phase epitaxy (MOVPE). N-type cladding layer (second semiconductor layer) 501 composed of _y P(0≦x≦1, 0.4≦y≦0.6), from (Al _x Ga _1-x ) _y In _1-y P(0≦x≦ 1,0.4≦y≦0.6), an active layer 502, and a P-type coating layer composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) (First semiconductor layer) 503, an AlGaInP-based epitaxial wafer 500 of red and yellow luminescent material is produced. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method.

Next, benzocyclobutene (BCB) was applied onto the epitaxial surface (P-type cladding layer 503) of the AlGaInP-based epitaxial wafer 500 at a number of revolutions of 3,000 rpm or more to form a BCB film 504 having a film thickness of about 1 μm. Then, as shown in (c) of FIG. 5, the BCB coated surface of the AlGaInP-based epitaxial wafer 500 is brought into contact with the epitaxial surface (P-type cladding layer 553) of the InGaN-based epitaxial wafer 550, and is brought into contact with The pressure of 500 N or more is pressed together, and by holding the temperature at 150 ° C or higher, the bonded wafer 50 for bonding the two wafers can be formed. In addition, the BCB film may be formed only on either of the first epitaxial substrate and the second epitaxial substrate, or both.

Further, the thickness of the GaAs substrate of the AlGaInP-based epitaxial wafer 500 may be film-processed to a thickness of about 50 to 100 μm by etching or wheel grinding before bonding. By the film processing, the AlGaInP-based epitaxial wafer 500 is easily deformed during bonding, and has an effect of improving the yield after bonding.

Next, as shown in (d) of FIG. 5, the wafer 51 of the GaAs substrate 505 from which the AlGaInP-based epitaxial wafer 500 is removed by chemical etching is formed. The chemical etching solution preferably has an etch selectivity to the AlGaInP-based material, and is generally removed by an ammonia-containing etchant. At this time, the substrate processed or removed by the film may be a sapphire substrate 555.

Next, as shown in (e) of FIG. 5, a first electrode (first ohmic electrode) 511 is formed on the N-type cladding layer 501 (non-removed portion 510) of the AlGaInP-based epitaxial wafer 500, and is removed. The portion 520 is formed in a shape of a hole or a groove having a depth of the P-type cladding layer 503 (that is, a removal portion excluding the N-type cladding layer 501 and the active layer 502), and is formed at the bottom of the removal portion 520. A second electrode (second ohmic electrode) 521 that is in contact with the type cladding layer 503.

Next, as shown in (f) of FIG. 5, a part of the region 530 where the first electrode 511 and the second electrode 521 are not formed is removed at the epitaxial layer made of an AlGaInP-based material. The removal of the region 530 exposes the BCB film 504 on the surface of the InGaN-based epitaxial wafer by an ICP etching method using an atmosphere containing a Cl-based gas (Cl ₂ , BCl ₃ , or SiCl ₄ ). Then, the BCB film 504 is removed by an ICP etching method containing an atmosphere of a class F gas (CF ₄ , CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , NF ₃ , SF ₄ , SF ₆ ) to expose an InGaN-based epitaxial crystal. Round surface (P-type cladding layer 553).

Next, as shown in (g) of FIG. 5, a third electrode (first ohmic electrode) 561 is formed on the P-type cladding layer 553 (non-removed portion 560) of the exposed InGaN-based epitaxial wafer 550, and The removal portion 570 is formed in a shape of a hole or a groove having a depth of the N-type cladding layer 551 (that is, a removal portion excluding the P-type cladding layer 553 and the active layer 552), and is formed at the bottom of the removal portion 570. A fourth electrode (second ohmic electrode) 571 that is in contact with the N-type cladding layer 551.

Next, as shown in (h) of FIG. 5, bumps 540 are formed on the first electrode 511, the second electrode 521, the third electrode 561, and the fourth electrode 571 to form a light-emitting wafer (light-emitting element 52). In addition, the bumps may be formed through the studs or may be formed by plating.

(Sixth embodiment) A sixth embodiment of the light-emitting device of the present invention will be described with reference to (h) of Fig. 6. As shown in (h) of FIG. 6, the light-emitting element 62 in the sixth embodiment of the present invention is a sapphire substrate 655 including a window layer and a supporting substrate, and a blue-green color system provided on the sapphire substrate 655. A light-emitting element of a light-emitting portion composed of an InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material.

A light-emitting portion made of a blue-green InGaN-based material has an N-type cladding layer (second semiconductor layer) 651 composed of Al _s Ga _1-s N (0≦s≦1), and is composed of In _s Ga _{The order} of the active layer 652 composed of _1-s N(0≦s≦1) and the P-type cladding layer (first semiconductor layer) 653 composed of Al _s Ga _1-s N(0≦s≦1) The formed structure has a removal portion 670 in which the P-type cladding layer 653 and the active layer 652 are removed, and a non-removed portion 660 other than the removal portion 670, and is provided on the non-removed portion 660 and the P-type cladding layer 653. A third electrode (first ohmic electrode) 661 that is in contact with each other, and a fourth electrode (second ohmic electrode) 671 that is disposed in the removal portion 670 and is in contact with the N-type cladding layer 651.

A light-emitting portion composed of a red-yellow AlGaInP-based material has a P-type cladding composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) a layer (first semiconductor layer) 603, an active layer 602 composed of (Al _x Ga _1-x ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and (Al _x Ga _{1 -x} ) a structure formed by the order of the N-type cladding layer (second semiconductor layer) 601 composed of _y In _1-y P (0≦x≦1, 0.4≦y≦0.6), and having an N-type cladding layer The removal portion 620 from which the active layer 602 is removed and the non-removed portion 610 other than the removal portion 620 further include a first electrode (first ohmic electrode) provided in the non-removed portion 610 and in contact with the N-type cladding layer 601 611 and a second electrode (second ohmic electrode) 621 provided on the removal portion 620 and in contact with the P-type cladding layer 603. In addition, the light-emitting portion composed of a red-yellow AlGaInP-based material is bonded to an epitaxial layer (N-type cladding layer) constituting a light-emitting portion composed of a blue-green InGaN-based material through two SiO ₂ films 606 and 656. Above the 651, the active layer 652 and the P-type cladding layer 653).

Furthermore, the two light-emitting portions are covered by the insulating layer 615, and the bumps 640 are formed on the first electrode 611, the second electrode 621, the third electrode 661, and the fourth electrode 671.

Next, a method of manufacturing a light-emitting element according to a sixth embodiment of the present invention will be described with reference to FIGS. 6(a) to (h). First, as shown in (a) of FIG. 6, the sapphire substrate 655 is sequentially laminated by Al _s Ga _1-s N (0≦s≦1) by, for example, an organometallic vapor phase epitaxy (MOVPE). An N-type cladding layer (second semiconductor layer) 651, an active layer 652 composed of In _s Ga _1-s N (0≦s≦1), and Al _s Ga _1-s N (0≦s) ≦ 1) A P-type cladding layer (first semiconductor layer) 653 is formed to form an InGaN-based epitaxial wafer 650 of blue or green light-emitting material. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method. A SiO ₂ film 656 is then formed on the P-type cladding layer 653.

Further, as shown in (b) of FIG. 6, the GaAs substrate 605 is sequentially laminated by (Al _x Ga _1-x ) _y In _1- by, for example, an organometallic vapor phase epitaxy (MOVPE). N-type cladding layer (second semiconductor layer) 601 composed of _y P(0≦x≦1, 0.4≦y≦0.6), from (Al _x Ga _1-x ) _y In _1-y P(0≦x≦ 1,0.4≦y≦0.6), an active layer 602, and a P-type coating layer composed of (Al _x Ga _1-x ) _y In _1-y P(0≦x≦1, 0.4≦y≦0.6) (First semiconductor layer) 603, an AlGaInP-based epitaxial wafer 600 of red and yellow luminescent material is produced. Further, the production method is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method. Then, an SiO ₂ film 606 is formed on the P-type cladding layer 603. Further, the SiO ₂ film may be formed only in either the first epitaxial substrate or the second epitaxial substrate, or both.

Next, as shown in (c) of FIG. 6, the InGaN-based epitaxial wafer 650 and the AlGaInP-based epitaxial wafer 600 are bonded. At this time, both the AlGaInP-based epitaxial wafer 600 and the InGaN-based epitaxial wafer 650 are immersed in an alkaline solution (aqueous KOH solution or NaOH aqueous solution, etc.) to alkali treat the surface, and then the AlGaInP-based epitaxial wafer 600 is The SiO ₂ film of the InGaN-based epitaxial wafer 650 is contacted in a vacuum, and is pressed at a pressure of 500 N or more, and by holding the temperature at 700 ° C or higher, the bonded wafer 60 for bonding the two wafers can be formed. .

Next, as shown in (d) of FIG. 6, the wafer 61 of the GaAs substrate 605 from which the AlGaInP-based epitaxial wafer 600 is removed is formed by chemical etching. The chemical etching solution preferably has an etch selectivity to the AlGaInP-based material, and is generally removed by an ammonia-containing etchant. At this time, the substrate processed or removed by the film may be a sapphire substrate 655.

Next, as shown in (e) of FIG. 6, a first electrode (first ohmic electrode) 611 is formed on the N-type cladding layer 601 (non-removed portion 610) of the AlGaInP-based epitaxial wafer 600, and is removed. The portion 620 is formed in a shape of a hole or a groove having a depth of the P-type cladding layer 603 (that is, a removal portion excluding the N-type cladding layer 601 and the active layer 602), and is formed at the bottom of the removal portion 620 and P. The second electrode (second ohmic electrode) 621 to which the type cladding layer 603 is connected.

Next, as shown in (f) of FIG. 6, a portion of the region 630 where the first electrode 611 and the second electrode 621 are not formed is removed at the epitaxial layer made of an AlGaInP-based material. The removal of the region 630 exposes the SiO ₂ film 606 formed on the InGaN-based epitaxial wafer by an ICP etching method using an atmosphere containing a Cl-based gas (Cl ₂ , BCl ₃ , or SiCl ₄ ). Then, the SiO ₂ films 606 and 656 are removed by an ICP etching method containing an atmosphere of a F-type gas (CF ₄ , CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , NF ₃ , SF ₄ , SF ₆ ) to expose the InGaN-based film. The surface of the epitaxial wafer (P-type cladding layer 653).

Next, as shown in (g) of FIG. 6, a third electrode (first ohmic electrode) 661 is formed on a portion (removed portion 660) of the P-type cladding layer 653 of the exposed InGaN-based epitaxial wafer 650, and The removing portion 670 is formed in a shape of a hole or a groove having a depth of the P-type cladding layer 651 (that is, a removal portion excluding the P-type cladding layer 653 and the active layer 652), and is formed at the bottom of the removing portion 670. A fourth electrode (second ohmic electrode) 671 that is in contact with the N-type cladding layer 651.

Next, as shown in (h) of FIG. 6, bumps 640 are formed on the first electrode 611, the second electrode 621, the third electrode 661, and the fourth electrode 671 to form a light-emitting wafer (light-emitting element 62). In addition, the bumps may be formed through the studs or may be formed by plating.

Further, in the light-emitting element manufactured in the first to sixth embodiments described above, the light-emitting portion composed of the cyan-based InGaN-based material is coated with N-type from the side of the sapphire substrate (window layer and supporting substrate). The layer (second semiconductor layer), the active layer, and the P-type cladding layer (first semiconductor layer) are sequentially formed; and the light-emitting portions composed of red-yellow AlGaInP-based materials are all from the sapphire substrate (window layer and support) The substrate side is formed in the order of the P-type cladding layer (first semiconductor layer), the active layer, and the N-type cladding layer (second semiconductor layer), but the present invention is not limited thereto. In order to change the order of the second semiconductor layer and the first semiconductor layer in each of the light-emitting portions, the order of formation of the second semiconductor and the first semiconductor may be changed when the first epitaxial substrate or the second epitaxial substrate is formed.

Further, as shown in the first to sixth embodiments, even when a light-emitting portion made of a red-yellow AlGaInP-based material is bonded to an epitaxial layer made of a blue-green-type InGaN-based material, Since the junction surface of the light-emitting portion made of a red-yellow AlGaInP-based material and the epitaxial layer made of a blue-green-type InGaN-based material has high resistance, the light-emitting portion made of a red-yellow AlGaInP-based material is energized. At this time, it is not energized to the epitaxial layer composed of a cyan-based InGaN-based material located at the lower portion thereof.

(Manufacturing Method of Light-Emitting Element Array Substrate) Next, a method of manufacturing a light-emitting element array substrate by mounting a light-emitting element manufactured according to the first to sixth embodiments described above to a wiring substrate, with reference to FIGS. 7 to 9 An example of this is explained.

As shown in FIG. 7, the FET control unit 701 for blue and green light-emitting elements and the FET control unit 751 for yellow and red light-emitting elements are provided on the Si wafer 700. The FET control units 701 and 751 are provided with source (711, 761), drain (712, 762), gate oxide film (713, 763), gate (714, 764), and reverse region (715, 765). ). The drain electrodes (712, 762) are connected to the source lines (741, 791) through the wiring portions (740, 790). The pad electrode portions (731, 732, 781, and 782) are partially provided on the wiring portions (721, 722, 771, and 772) to form the driver circuit wafer 800.

Alternatively, the driver circuit wafer 800' shown in Fig. 8 may be used instead of the driver circuit wafer 800 shown in Fig. 7. Driving circuit wafer 800', as shown in Fig. 8, in the Si wafer 700', the FET control units (701', 751') are not connected to the wiring portions (721', 722', 771', 772') and The pad electrode portions (731', 732', 781', 782') are formed on the same surface but on the opposite surfaces via via holes (745', 795'). In addition, the source (711', 761'), the drain (712', 762'), the gate oxide film (713', 763'), the gate (714', 764'), the inversion region (715' 765'), wiring (740', 790'), and source lines (741', 791') are formed in the same manner as the above-described driving circuit wafer 800.

Next, the light-emitting wafers (light-emitting elements 12, 22, 32, 42, 52, 62) and the driver circuit wafer 800 are overlapped and joined, and the first embodiment will be described as an example. As shown in FIG. 9, the bump 140 on the light-emitting element (light-emitting wafer) 12 is bonded to the pad electrode portions (731, 732, 781, 782) on the driver circuit wafer 800, and then bonded. The bump 140 and the pad electrode portions (731, 732, 781, 782) are bonded by applying a pressure of 10 N or more and ultrasonic waves, thereby obtaining the light-emitting element array substrate 900.

Further, in the first embodiment, the refractive index of GaN to the red to yellow emission wavelength is 2.4, and the refractive index of AlGaInP is 3.4. At this time, the total reflection angle can obtain a light distribution angle of up to 40 degrees.

Further, in the second and third embodiments, in order to pass through the BCB film and the SiO ₂ film, the refractive index of the SiO ₂ film was 1.5, and the refractive index of AlGaInP was 3.4. At this time, the total reflection angle is 24 degrees and is narrower than that of the first embodiment, but a joint stronger than the first embodiment can be obtained at the mechanical level.

Further, in the fourth to sixth embodiments, since the light-emitting layer is not notched, but a via hole is formed to make an ohmic contact with the lower layer, a wide light-emitting layer area can be obtained, and each of the light-emitting layers can be realized. An array of light-emitting elements with increased brightness of the elements.

Further, in the first to third embodiments, the light-emitting elements having different emission wavelengths are arranged in the planar direction in order to form one pixel, but in the fourth to sixth embodiments, the light extraction direction is possible. By arranging and arranging light-emitting elements of a plurality of wavelengths, it is possible to achieve a minimum area required for contact per area of one pixel. In this way, the components per one pixel can be designed to be larger, and the component area can be enlarged, whereby the characteristic variation of each component can be reduced.

Further, in the first to sixth embodiments described above, a light-emitting portion composed of a blue-green-based InGaN-based material and a light-emitting portion composed of a red-yellow AlGaInP-based material are used as an emission wavelength phase. The light-emitting portion of the present invention is not limited thereto, and various conventional light-emitting wavelengths (materials) can be used. For example, in addition to the above materials, ZnSe-based or ZnO-based materials can be used. , GaO and other materials. Then, in the manufacture of the light-emitting element, an epitaxial substrate having a desired emission wavelength is prepared as the first epitaxial substrate and the second epitaxial substrate, and by combining them, it is easy to manufacture a plurality of desired illuminations. A light-emitting element of a light-emitting portion of a wavelength.

As described above, in the case of the light-emitting element of the present invention, a plurality of light-emitting portions having different light-emitting wavelengths can be formed in the same light-emitting element, and for example, two colors of blue to green and yellow to red can be obtained. It is displayed, and it is possible to prevent the light of a plurality of wavelengths from interfering with each other, and to radiate it to the external light-emitting element while maintaining high luminance. Therefore, in the case of the light-emitting element of the present invention, it is particularly suitable for a light-emitting element array having a narrow pitch. Further, in the method for producing a light-emitting device of the present invention, since the light-emitting portions of the two kinds of light-emitting wavelengths are individually formed and then joined, it is possible to grow the respective light-emitting portions under the most suitable crystal growth conditions, thereby obtaining a pair. Each of the light-emitting wavelengths has a highly efficient light-emitting layer (light-emitting element region). In this way, a plurality of light-emitting portions having different light-emitting wavelengths can be easily manufactured, and light of a plurality of wavelengths can be prevented from interfering with each other, and can be radiated to the outside while maintaining high luminance, and is suitable for narrow pitches. A light-emitting element of an array of light-emitting elements.

Further, the present invention is not limited to the above embodiments. The above-described embodiments are exemplified, and those having substantially the same technical concept as those described in the claims of the present invention have the same effects, and are included in the technical scope of the present invention.

10‧‧‧ Bonded wafer
100‧‧‧AlGaInP epitaxial wafer
101‧‧‧N type coating
102‧‧‧Active layer
103‧‧‧P type coating
105‧‧‧GaAs substrate
11‧‧‧ wafer
110‧‧‧ Non-removal department
111‧‧‧First electrode
115‧‧‧Insulation
12‧‧‧Lighting elements
120‧‧‧Removal
121‧‧‧second electrode
130‧‧‧Area
140‧‧‧Bumps
150‧‧‧InGaN epitaxial wafer
151‧‧‧N type coating
152‧‧‧Active layer
153‧‧‧P type coating
155‧‧‧Sapphire substrate
160‧‧‧Non-removal department
161‧‧‧ third electrode
170‧‧‧Removal
171‧‧‧fourth electrode
20‧‧‧ Bonded wafer
200‧‧‧AlGaInP epitaxial wafer
201‧‧‧N type coating
202‧‧‧Active layer
203‧‧‧P type coating
204‧‧‧BCB film
205‧‧‧GaAs substrate
21‧‧‧ wafer
210‧‧‧ Non-removal department
211‧‧‧First electrode
215‧‧‧Insulation
22‧‧‧Lighting elements
220‧‧‧Removal
221‧‧‧second electrode
230‧‧‧ Area
240‧‧‧Bumps
250‧‧‧InGaN epitaxial wafer
251‧‧‧N type cladding layer (second semiconductor layer)
252‧‧‧active layer
253‧‧‧P type coating
255‧‧‧Sapphire substrate
260‧‧‧ Non-removal department
261‧‧‧ third electrode
270‧‧‧Removal
271‧‧‧fourth electrode
30‧‧‧ Bonded wafer
300‧‧‧AlGaInP epitaxial wafer
301‧‧‧N type coating
302‧‧‧Active layer
303‧‧‧P type coating
305‧‧‧GaAs substrate
306‧‧‧SiO2 film
31‧‧‧ Wafer
310‧‧‧Non-removal department
311‧‧‧First electrode
315‧‧‧Insulation
32‧‧‧Lighting elements
320‧‧‧Removal
321‧‧‧second electrode
330‧‧‧Area
340‧‧‧Bumps
350‧‧‧InGaN epitaxial wafer
351‧‧‧N type coating
352‧‧‧Active layer
353‧‧‧P type coating
355‧‧‧Sapphire substrate
356‧‧‧SiO2 film
360‧‧‧ Non-removal department
361‧‧‧ third electrode
370‧‧‧Removal
371‧‧‧fourth electrode
40‧‧‧ Bonded wafer
400‧‧‧AlGaInP epitaxial wafer
401‧‧‧N type coating
402‧‧‧Active layer
403‧‧‧P type coating
405‧‧‧GaAs substrate
41‧‧‧ wafer
410‧‧‧ Non-removal department
411‧‧‧First electrode
415‧‧‧Insulation
42‧‧‧Lighting elements
420‧‧‧Removal
421‧‧‧second electrode
430‧‧‧Area
440‧‧‧Bumps
450‧‧‧InGaN epitaxial wafer
451‧‧‧N type coating
452‧‧‧active layer
453‧‧‧P type coating
455‧‧‧Sapphire substrate
460‧‧‧ Non-removal department
461‧‧‧ third electrode
470‧‧‧Removal
471‧‧‧fourth electrode
50‧‧‧ Bonded wafer
500‧‧‧AlGaInP epitaxial wafer
501‧‧‧N type coating
502‧‧‧Active layer
503‧‧‧P type coating
504‧‧‧BCB film
505‧‧‧GaAs substrate
51‧‧‧ wafer
510‧‧‧ Non-removal department
511‧‧‧First electrode
515‧‧‧Insulation
52‧‧‧Lighting elements
520‧‧‧Removal
521‧‧‧second electrode
530‧‧‧Area
540‧‧‧Bumps
550‧‧‧InGaN epitaxial wafer
551‧‧‧N type coating
552‧‧‧Active layer
553‧‧‧P type coating
555‧‧‧Sapphire substrate
560‧‧‧ Non-removal department
561‧‧‧ third electrode
570‧‧‧Removal
571‧‧‧fourth electrode
60‧‧‧ Bonded wafer
600‧‧‧AlGaInP epitaxial wafer
601‧‧‧N type coating
602‧‧‧active layer
603‧‧‧P type coating
605‧‧‧ on GaAs substrate
606‧‧‧SiO2 film
61‧‧‧ wafer
610‧‧‧ Non-removal department
611‧‧‧first electrode
615‧‧‧Insulation
62‧‧‧Lighting elements
620‧‧‧Removal
621‧‧‧second electrode
630‧‧‧Area
640‧‧ ‧bumps
650‧‧‧InGaN epitaxial wafer
651‧‧‧N type coating
652‧‧‧active layer
653‧‧‧P type coating
655‧‧‧Sapphire substrate
656‧‧‧SiO2 film
660‧‧‧ Non-removal department
661‧‧‧ third electrode
670‧‧‧Removal
671‧‧‧fourth electrode
700‧‧‧Si Wafer
700'‧‧‧Si Wafer
701‧‧‧FET Control Department
701'‧‧‧FET Control Department
711‧‧‧ source
711'‧‧‧ source
712‧‧‧汲polar
712'‧‧‧汲polar
713‧‧‧Gate oxide film
713'‧‧‧ gate oxide film
714‧‧‧ gate
714'‧‧‧ gate
715‧‧‧Reversal zone
715'‧‧‧Reversal zone
721‧‧‧Wiring Department
721'‧‧‧Wiring Department
722‧‧‧Wiring Department
722'‧‧‧Wiring Department
731‧‧‧pad electrode
731'‧‧‧ solder pad electrode
732‧‧‧pad electrode
732'‧‧‧ solder pad electrode
740‧‧‧Wiring Department
740'‧‧‧ wiring
741‧‧‧ source line
741'‧‧‧ source line
745'‧‧‧through hole
751‧‧‧FET Control Department
751'‧‧‧FET Control Department
761‧‧‧ source
761'‧‧‧ source
762‧‧‧汲
762'‧‧‧汲
763‧‧‧Gate oxide film
763'‧‧‧ gate oxide film
764‧‧‧ gate
764'‧‧‧ gate
765‧‧‧Reversal zone
765'‧‧‧Reversal zone
771'‧‧‧Wiring Department
772'‧‧‧Wiring Department
781‧‧‧Wiring Department
781'‧‧‧ solder pad electrode
782‧‧‧Wiring Department
782'‧‧‧ solder pad electrode
790‧‧‧Wiring Department
790'‧‧‧ wiring
791‧‧‧ source line
791'‧‧‧ source line
795'‧‧‧through hole
800‧‧‧Drive Circuit Wafer
800'‧‧‧Drive Circuit Wafer'
900‧‧‧Light-emitting element array substrate

Fig. 1 is a schematic view showing a first embodiment of a method of manufacturing a light-emitting element of the present invention. Fig. 2 is a schematic view showing a second embodiment of the method for producing a light-emitting element of the present invention. Fig. 3 is a schematic view showing a third embodiment of a method of manufacturing a light-emitting element of the present invention. Fig. 4 is a schematic view showing a fourth embodiment of the method for producing a light-emitting element of the present invention. Fig. 5 is a schematic view showing a fifth embodiment of the method for producing a light-emitting element of the present invention. Fig. 6 is a schematic view showing a sixth embodiment of a method of manufacturing a light-emitting element of the present invention. Fig. 7 is a schematic view showing an example of a wiring substrate on which the light-emitting element of the present invention is mounted. Fig. 8 is a schematic view showing another example of a wiring substrate on which the light-emitting element of the present invention is mounted. Fig. 9 is a view showing an example of a light-emitting element of the present invention mounted on a wiring substrate.

Claims (12)

A light-emitting element comprising a window layer and a supporting substrate, and a plurality of light-emitting portions disposed on the window layer and supporting substrate and having different emission wavelengths, wherein the plurality of light-emitting portions each have a second semiconductor of a second conductivity type a structure formed by the order of the layer, the active layer, and the first semiconductor layer of the first conductivity type, and having the removal portion of the first semiconductor layer or the second semiconductor layer and the active layer removed, and the removal portion The non-removed portion further includes a first ohmic electrode provided on the non-removed portion and a second ohmic electrode provided on the removed portion. The light-emitting element according to claim 1, wherein one of the plurality of light-emitting portions is formed by an epitaxial layer directly formed on the window layer and the support substrate, and the other light-emitting portions are bonded to the epitaxial layer. Above the layer. The light-emitting element according to claim 2, wherein the epitaxial layer directly formed on the window layer supporting substrate and the light emitting portion bonded over the epitaxial layer have a benzocyclobutene film or SiO ₂ membrane. The light-emitting element according to any one of claims 1 to 3, wherein the plurality of light-emitting portions include a light-emitting portion composed of a cyan-based InGaN-based material, and a light-emitting portion composed of a red-yellow AlGaInP-based material unit. A method for manufacturing a light-emitting device, comprising the steps of: preparing a first epitaxial substrate and a second epitaxial substrate, wherein the first epitaxial substrate has an epitaxial layer on the first substrate that emits light of a first wavelength, a second epitaxial substrate is grown on the second substrate with an epitaxial layer emitting light of a second wavelength; an epitaxial layer of the first epitaxial substrate and an epitaxial layer of the second epitaxial substrate; and The bonded epitaxial substrate removes the first substrate or the second substrate. The method for producing a light-emitting device according to claim 5, wherein the epitaxial layer is used as an emitting light of a first wavelength, and the AlGaInP-based material is used as the epitaxial layer emitting light of a second wavelength. . The method of manufacturing a light-emitting device according to claim 5, wherein the epitaxial structure having the structure formed by the second semiconductor layer of the second conductivity type, the active layer, and the first semiconductor layer of the first conductivity type is formed. The layer serves as the epitaxial layer that emits light of a first wavelength and the epitaxial layer that emits light of a second wavelength. The method of manufacturing a light-emitting device according to claim 6, wherein the epitaxial structure having the structure formed by the second semiconductor layer of the second conductivity type, the active layer, and the first semiconductor layer of the first conductivity type is formed. The layer serves as the epitaxial layer that emits light of a first wavelength and the epitaxial layer that emits light of a second wavelength. The method for fabricating a light-emitting device according to claim 7, further comprising the step of: after the step of removing the first substrate or the second substrate, emitting the epitaxial layer of light of a first wavelength and emitting a second wavelength In the epitaxial layer of the light, a removal portion that removes the first semiconductor layer or the second semiconductor layer and the active layer, and a non-removed portion other than the removed portion are formed, and the first portion is provided in the non-removed portion. An ohmic electrode and a second ohmic electrode are disposed on the removed portion. The method for manufacturing a light-emitting device according to claim 8, further comprising the step of: after the step of removing the first substrate or the second substrate, emitting the epitaxial layer of light of a first wavelength and emitting a second wavelength In the epitaxial layer of the light, a removal portion that removes the first semiconductor layer or the second semiconductor layer and the active layer, and a non-removed portion other than the removed portion are formed, and the first portion is provided in the non-removed portion. An ohmic electrode and a second ohmic electrode are disposed on the removed portion. The method of manufacturing a light-emitting device according to any one of claims 5 to 10, wherein before the step of bonding the epitaxial layer of the first epitaxial substrate and the epitaxial layer of the second epitaxial substrate, Forming a benzocyclobutene film on at least one of an epitaxial layer of the first epitaxial substrate and an epitaxial layer of the second epitaxial substrate, and then bonding the first ray through the benzocyclobutene film An epitaxial layer of the crystal substrate and an epitaxial layer of the second epitaxial substrate. The method of manufacturing a light-emitting device according to any one of claims 5 to 10, wherein before the step of bonding the epitaxial layer of the first epitaxial substrate and the epitaxial layer of the second epitaxial substrate, Forming an SiO ₂ film on at least one of an epitaxial layer of the first epitaxial substrate and an epitaxial layer of the second epitaxial substrate, and then bonding the epitaxial layer of the first epitaxial substrate through the SiO ₂ film And an epitaxial layer of the second epitaxial substrate.