JP5304605B2 - Semiconductor light emitting device manufacturing method, lamp, electronic device, and mechanical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor element hardly causing a failure of a light-emitting layer and a p-type semiconductor layer due to a regrowth layer surface and providing a high output. <P>SOLUTION: The method of manufacturing the semiconductor light-emitting element 1 includes: a first step of laminating a first n-type semiconductor layer 12c on a substrate 11, using a first organometallic chemical vapor deposition device; and a second step of sequentially laminating a regrowth layer 12d of the first n-type semiconductor layer 12c, a second n-type semiconductor layer 12b, a light-emitting layer 13, and a p-type semiconductor layer 14 on the first n-type semiconductor layer 12c, using a second organometallic chemical vapor deposition device, wherein, at the second step, Mg is doped when the regrowth layer 12d is formed. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor light-emitting element, a lamp, an electronic device, and a mechanical device. In particular, the semiconductor is suitably used when a large current is applied, and a semiconductor capable of obtaining a high light emission output when the large current is applied. The present invention relates to a method for manufacturing a light-emitting element, and a lamp, an electronic apparatus, and a mechanical device including a semiconductor light-emitting element manufactured using the manufacturing method.

  2. Description of the Related Art Conventionally, as a semiconductor light emitting element used for a light emitting diode or the like, there is one in which an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer are sequentially stacked on a substrate. As a method for manufacturing such a semiconductor light emitting device, an n-type semiconductor layer, a light emitting layer, and a p layer are formed on a substrate made of a sapphire single crystal by a metal organic chemical vapor deposition (MOCVD) method. There is a method of successively and successively stacking a type semiconductor layer.

  However, when an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer are sequentially and sequentially stacked on a substrate, these layers are formed in the same growth chamber. In some cases, the dopant used in the step hinders the formation of the p-type semiconductor layer, and a p-type semiconductor layer having a sufficiently low resistivity cannot be obtained.

  As a technique for solving such a problem, for example, Patent Document 1 discloses a compound semiconductor device in which at least a first conductivity type semiconductor layer and a second conductivity type semiconductor layer are sequentially formed on a predetermined substrate. In manufacturing a compound semiconductor device, a semiconductor layer of each conductivity type is formed in a plurality of different independent growth chambers corresponding to the conductivity type.

  Recently, in order to improve the light emission output of the semiconductor light emitting device, a large current is often applied to the semiconductor light emitting device.

Japanese Unexamined Patent Publication No. 7-45538

However, if the growth chamber for forming the n-type semiconductor layer and the growth chamber for forming the p-type semiconductor layer are separately provided, the output of the obtained semiconductor element may be insufficient.
For example, n is formed in a second growth chamber on a GaN underlayer and an n-type GaN contact layer (first n-type semiconductor layer, generically a template wafer film) via a buffer layer on a substrate made of sapphire single crystal or the like. When the type GaN contact layer (the regrowth layer of the first n-type semiconductor layer or simply the regrowth layer) is formed, the flatness of the regrowth layer surface often deteriorates.

At this time, if the film formation temperature is set to a high temperature of 1000 ° C. or higher when forming the regrowth layer, pits do not appear, so that a regrowth layer with high crystallinity can be obtained. However, such a high temperature makes it easier for the regrowth layer to sublimate, and the flatness of the regrowth layer surface deteriorates.
In addition, when the flatness of the regrowth layer surface deteriorates in such a manner, in a subsequent process, a light emitting layer (MQW layer) or a P-type semiconductor layer is grown on the regrowth layer surface in the second growth chamber. When the chip is formed, there is a problem that the yield rate of the LED chip within the standard is deteriorated.

  The present invention has been made in view of the above problems, and it is difficult for the light emitting layer and the p-type semiconductor layer to be defective due to the surface of the regrowth layer (the regrowth layer of the first n-type semiconductor layer), and high output. It is an object of the present invention to provide a method for manufacturing a semiconductor device obtained.

In order to achieve the above object, the present invention provides the following means.
[1] In a first organometallic chemical vapor deposition apparatus, a first step of laminating a first n-type semiconductor layer on a substrate; and in a second organometallic chemical vapor deposition apparatus, on the first n-type semiconductor layer A second step of sequentially laminating a regrowth layer of the first n-type semiconductor layer, a second n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer, and in the second step, the regrowth layer A method of manufacturing a semiconductor light emitting device, wherein Mg is doped when forming the semiconductor.
[2] The method for manufacturing a semiconductor light-emitting element according to [1], wherein the regrowth layer is formed by supplying a dopant gas containing Mg together with the source gas of the regrowth layer.
[3] The method for manufacturing a semiconductor light-emitting element according to [2], wherein supply of the dopant gas is started simultaneously with the start of formation of the regrowth layer, and supply is stopped during the formation of the regrowth layer.
[4] The method for manufacturing a semiconductor light-emitting element according to [ 3 ] , wherein the time for supplying the dopant gas is 1/10 to 2/3 of the entire time for forming the regrowth layer.
[5] The method for manufacturing a semiconductor light-emitting element according to [1], wherein the substrate temperature when forming the regrowth layer is 1000 ° C. to 1100 ° C.
[6] The semiconductor light-emitting element according to [1], wherein the Mg is contained in a portion near the substrate in the regrown layer at a concentration of 1 × 10 ¹⁷ to 1 × 10 ¹⁹ / cm ³ . Production method.
[7] The method for manufacturing a semiconductor light-emitting element according to [1], wherein a thickness of the regrowth layer is 0.1 μm to 1 μm.
[8] A semiconductor light emitting device in which a first n-type semiconductor layer, a regrowth layer of the first n-type semiconductor layer, a second n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer are stacked on a substrate. the Mg is included in at least the substrate side of the portion of the regrown layer, the thickness of the portion containing the Mg and the said 1 / 10-2 / 3 der Rukoto thickness of the regrown layer A semiconductor light emitting device.
[9] A lamp comprising a semiconductor light-emitting device manufactured using the method for manufacturing a semiconductor light-emitting device according to any one of [1] to [7].
[10] An electronic device in which the lamp according to [ 9 ] is incorporated.
[11] A mechanical apparatus in which the electronic device according to [10 ] is incorporated.

  According to the method for manufacturing a semiconductor device of the present invention, in the step of forming the regrowth layer in the second growth chamber (second organometallic chemical vapor deposition apparatus), Mg is contained together with the source gas of the regrowth layer. By supplying the dopant gas, Mg can be doped into at least a portion of the regrowth layer close to the substrate. Thereby, the flatness of the regrowth layer surface can be improved. Therefore, a light-emitting layer (MQW layer) or a P-type semiconductor layer with good crystallinity can be grown in subsequent steps. As a result, it is possible to improve the yield rate of the LED chip within the standard, and it is possible to significantly improve productivity in terms of yield.

FIG. 1 is a schematic cross-sectional view showing an example of a semiconductor light emitting device manufactured using the method for manufacturing a semiconductor light emitting device of the present invention. FIG. 2 is a schematic cross-sectional view for explaining a process for manufacturing the semiconductor light emitting element shown in FIG. FIG. 3 is a schematic cross-sectional view showing an example of a lamp including the semiconductor light emitting element shown in FIG.

  Hereinafter, the semiconductor light emitting device 1 of the present invention will be described in detail with reference to FIG. The drawings referred to in the following description are for explaining the present invention, and the size, thickness, dimensions, etc. of each part shown in the drawings are different from the dimensional relationships of actual semiconductor light emitting elements, lamps, etc. Yes.

FIG. 1 is a schematic cross-sectional view showing an example of a semiconductor light emitting device 1 of the present invention.
A semiconductor light emitting device 1 according to this embodiment shown in FIG. 1 includes a substrate 11, a laminated semiconductor layer 20 laminated on the substrate 11, a translucent electrode 15 laminated on the upper surface of the laminated semiconductor layer 20, The p-type bonding pad electrode 16 laminated on the conductive electrode 15 and the n-type electrode 17 laminated on the exposed surface 20a of the laminated semiconductor layer 20 are schematically configured.

The stacked semiconductor layer 20 is configured by stacking an n-type semiconductor layer 12, a light emitting layer 13, and a p-type semiconductor layer 14 in this order from the substrate 11 side. As shown in FIG. 1, the n-type semiconductor layer 12, the light emitting layer 13, and the p-type semiconductor layer 14 are partially removed by means such as etching, and one part of the n-type semiconductor layer 12 is removed from the removed portions. The part is exposed. An n-type electrode 17 is stacked on the exposed surface 20 a of the n-type semiconductor layer 12.
A translucent electrode 15 and a p-type bonding pad electrode 16 are stacked on the upper surface of the p-type semiconductor layer 14. The translucent electrode 15 and the p-type bonding pad electrode 16 constitute a p-type electrode 18.

As a semiconductor constituting the n-type semiconductor layer 12, the light emitting layer 13, and the p-type semiconductor layer 14, a group III nitride semiconductor is preferably used, and a gallium nitride compound semiconductor is more preferably used. As the gallium nitride-based compound semiconductor constituting the n-type semiconductor layer 12, the light emitting layer 13, and the p-type semiconductor layer 14 in the present invention, a general formula Al _x In _y Ga _1-xy N (0 ≦ x <1,0) Semiconductors having various compositions represented by ≦ y <1, 0 ≦ x + y <1) can be used without any limitation.

The semiconductor light emitting device 1 of the present embodiment can emit light from the light emitting layer 13 constituting the laminated semiconductor layer 20 by passing a current between the p-type electrode 18 and the n-type electrode 17. This is a face-up mount type light emitting element that extracts light from the light emitting layer 13 from the side where the p type bonding pad electrode 16 is formed. The semiconductor light emitting device of the present invention may be a flip chip type light emitting device.
Hereinafter, each configuration will be described in detail.

<Substrate 11>
Examples of the substrate 11 include sapphire, SiC, silicon, zinc oxide, magnesium oxide, manganese oxide, zirconium oxide, manganese zinc iron, magnesium aluminum oxide, zirconium boride, gallium oxide, indium oxide, lithium gallium oxide, and lithium oxide. A substrate formed of aluminum, neodymium gallium oxide, lanthanum strontium aluminum tantalum, strontium titanium oxide, titanium oxide, hafnium, tungsten, molybdenum, or the like can be used. Among the above substrates, it is particularly preferable to use a sapphire substrate having a c-plane as a main surface.

  Of the above substrates, an oxide substrate or a metal substrate that is known to cause chemical modification by contact with ammonia at a high temperature is used, and a buffer layer 21 described later is formed without using ammonia. In addition, when the underlayer 22 described later is formed by a method using ammonia, the buffer layer 21 acts as a coat layer, which is effective in preventing chemical alteration of the substrate 11.

(Buffer layer 21)
The buffer layer 21 may not be provided, but the difference in lattice constant between the substrate 11 and the base layer 22 is alleviated to form a C-axis oriented single crystal layer on the (0001) C plane of the substrate 11. It is preferable that it is provided in order to facilitate the process. When the single crystal underlayer 22 is laminated on the buffer layer 21, the underlayer 22 with better crystallinity can be laminated.

The buffer layer 21 is preferably made of polycrystalline Al _x Ga _1-x N (0 ≦ x ≦ 1), and more preferably made of single crystal Al _x Ga _1-x N (0 ≦ x ≦ 1). preferable.
The buffer layer 21 can be, for example, made of polycrystalline Al _x Ga _1-x N (0 ≦ x ≦ 1) and having a thickness of 0.01 to 0.5 μm. If the thickness of the buffer layer 21 is less than 0.01 μm, the buffer layer 21 may not sufficiently obtain an effect of relaxing the difference in lattice constant between the substrate 11 and the base layer 22. Further, when the thickness of the buffer layer 21 exceeds 0.5 μm, the film forming process time of the buffer layer 21 becomes long and the productivity is lowered although the function as the buffer layer 21 is not changed. There is.

  The buffer layer 21 may have a polycrystalline structure or a single crystal structure. When the buffer layer 21 having such a polycrystalline structure or a single crystal structure is formed on the substrate 11 by the MOCVD method or the sputtering method, the buffer function of the buffer layer 21 works effectively. The group III nitride semiconductor thus formed becomes a crystal film having good orientation and crystallinity.

(Underlayer 22)
_{Examples of the} underlayer 22 include Al _x Ga _y In _z N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, x + y + z = 1), and Al _x Ga _1-x N (0 ≦ x <1) is preferable because the base layer 22 having good crystallinity can be formed.
The film thickness of the underlayer 22 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and most preferably 1 μm or more. An Al _x Ga _1-x N layer with good crystallinity is more easily obtained when the thickness is increased. Further, the film thickness of the underlayer 22 is preferably 10 μm or less.
In order to improve the crystallinity of the underlayer 22, it is desirable that the underlayer 22 is not doped with impurities. However, when p-type or n-type conductivity is required, acceptor impurities or donor impurities can be added to the base layer 22.

<Laminated semiconductor layer 20>
(N-type semiconductor layer 12)
The n-type semiconductor layer 12 further includes an n-contact layer 12a (first n-type semiconductor layer 12c and regrowth layer 12d) and an n-cladding layer 12b (second n-type semiconductor layer).

(N contact layer 12a)
The n-contact layer 12a is a layer for providing the n-type electrode 17, and includes a first n-type semiconductor layer 12c (also referred to as a first process growth layer) formed in a first process described later and a second process described later. And a regrowth layer 12d formed in step (b). The first process growth layer 12c and the regrowth layer 12d are preferably made of the same material, and the thickness of the first process growth layer 12c is larger than the thickness of the regrowth layer 12d.
Further, in the present embodiment, as shown in FIG. 1, an exposed surface 20a for forming the n-type electrode 17 is formed on the first process growth layer 12c. The exposed surface 20a for providing the n-type electrode 17 may be formed in the regrowth layer 12d.

The n-contact layer 12a is preferably composed of an Al _x Ga _1-x N layer (0 ≦ x <1, preferably 0 ≦ x ≦ 0.5, more preferably 0 ≦ x ≦ 0.1), An n-type impurity (dopant) is doped. When n-type impurity is contained in n contact layer 12a at a concentration of 1 × 10 ¹⁷ to 1 × 10 ²⁰ / cm ³ , preferably 1 × 10 ¹⁸ to 1 × 10 ¹⁹ / cm ³ , From the viewpoint of maintaining good ohmic contact. The n-type impurity used for the n-contact layer 12a is not particularly limited, and examples thereof include Si, Ge, Sn, etc., Si and Ge are preferable, and Si is most preferable.

  The film thickness of the first step growth layer 12c constituting the n contact layer 12a is preferably 0.5 to 5 μm, and more preferably 2 to 4 μm. When the film thickness of the first process growth layer 12c is within the above range, the crystallinity of the semiconductor is favorably maintained.

  Mg is contained in the regrowth layer 12d of this embodiment. Mg may be contained in the entire regrowth layer 12d, but it is desirable that Mg is contained only in the portion near the substrate 11 in the regrowth layer 12d. By including Mg in the portion of the regrowth layer 12d close to the substrate 11, the flatness of the growth surface is improved, and the surface of the regrowth layer 12d on the light emitting layer 13 side is compared with the conventional manufacturing method. And formed flat.

  The thickness of the Mg-containing portion is preferably 1/10 to 2/3 of the thickness of the regrown layer 12d. If the thickness of the Mg-containing portion is less than 1/10 of the thickness of the regrowth layer 12d, the effect of the Mg-containing portion cannot be sufficiently obtained, and the surface of the regrowth layer 12d is not sufficiently flattened. On the other hand, when the thickness of the Mg-containing portion exceeds 2/3 of the thickness of the regrowth layer 12d, the drive voltage Vf when a current is passed is increased, so that the light emission output of the semiconductor element 1 is decreased.

The concentration of Mg contained in the Mg-containing portion of the regrowth layer 12d is desirably 1 × 10 ¹⁷ to 1 × 10 ¹⁹ / cm ³ . If the Mg concentration is less than 1 × 10 ¹⁷ , the effect of the Mg-containing portion cannot be sufficiently obtained, and the surface of the regrowth layer 12d is not sufficiently flattened. On the other hand, when the Mg concentration exceeds 1 × 10 ¹⁹ , the drive voltage Vf when a current is passed increases, and the regrowth layer 12d becomes p-type, so that the light emission output of the semiconductor element 1 decreases.

The film thickness of the regrowth layer 12d is preferably 0.2 μm to 1 μm. If the film thickness of the regrowth layer 12d is less than 0.2 μm, the planarization effect due to the Mg-containing portion cannot be sufficiently obtained, and thus the surface of the regrowth layer 12d on the light emitting layer 13 side is not sufficiently planarized.
On the other hand, when the film thickness of the regrowth layer 12d is 0.2 μm or more, the planarization effect due to the Mg-containing portion is sufficiently exhibited, so that the surface of the regrowth layer 12d on the light emitting layer 13 side is planarized.
If the thickness of the regrown layer 12d exceeds 1 μm, after the n-type semiconductor layer 12 is formed in the growth chamber of the second metal organic chemical vapor deposition apparatus used when forming the p-type semiconductor layer 14. The amount of remaining dopant and deposit increases, and the p-type semiconductor layer 14 is likely to be defective due to the dopant and deposit used when the n-type semiconductor layer 12 is formed. Furthermore, there is a problem that the film formation processing time of the regrowth layer 12d becomes long and the productivity is lowered.

  The n clad layer 12 b is provided between the n contact layer 12 a and the light emitting layer 13. The n-cladding layer 12b is a layer for injecting carriers into the light emitting layer 13 and confining carriers, and also serves as a buffer layer for the light emitting layer 13 that alleviates the mismatch of the crystal lattice between the regrown layer 12d and the light emitting layer 13. It functions. The n-clad layer 12b can be formed of AlGaN, GaN, GaInN, or the like. In the specification, the composition ratio of each element may be omitted and described as AlGaN, GaN, or GaInN. Needless to say, when the n-cladding layer 12b is formed of GaInN, it is desirable to make it larger than the band gap of GaInN of the light emitting layer 13.

When the n clad layer 12b is a single layer, the film thickness of the n clad layer 12b is preferably 5 to 500 nm, more preferably 5 to 100 nm. Moreover, it is preferable that the n-type dope density | concentration of the n clad layer 12b is 1 * 10 < ¹⁷ > -1 * 10 < ²⁰ > / cm < ³ >, More preferably, it is 1 * 10 < ¹⁸ > -1 * 10 < ¹⁹ > / cm < ³ >. When the doping concentration is within this range, it is preferable in terms of maintaining good crystallinity and reducing the operating voltage of the light emitting element.

  In this embodiment, the n-clad layer 12b may be a single layer, but consists of 10 pairs (20 layers) to 40 pairs (80 layers) by repeatedly growing two thin film layers having different compositions. A superlattice structure is preferred. When the n-cladding layer 12b has a superlattice structure, if the number of thin film layers is 20 or more, the crystal lattice mismatch between the regrown layer 12d and the light-emitting layer 13 is more effectively mitigated. Therefore, the effect of improving the output of the semiconductor light emitting device 1 becomes more remarkable. However, if the number of thin film layers exceeds 80, the superlattice structure may be easily disturbed, and the light emitting layer 13 may be adversely affected. Furthermore, there is a problem that the film forming process time of the n-clad layer 12b becomes long and productivity is lowered.

  The superlattice structure constituting the n-clad layer 12b includes an n-side first layer made of a group III nitride semiconductor and an n-side second layer made of a group III nitride semiconductor having a composition different from that of the n-side first layer. Are preferably laminated, and more preferably include a structure in which n-side first layers and n-side second layers are alternately and repeatedly laminated.

  The n-side first layer and the n-side second layer constituting the superlattice structure of the n-clad layer 12b are composed of GaInN / GaN alternating structure, AlGaN / GaN alternating structure, GaInN / AlGaN alternating structure, GaInN / An alternate structure of GaInN (in the present invention, the description of “different composition” indicates that each elemental composition ratio is different), an alternate structure of AlGaN / AlGaN having a different composition, and an alternate structure of GaInN / GaN. Alternatively, an alternate structure of GaInN / GaInN having different compositions is preferable.

  The thicknesses of the n-side first layer and the n-side second layer are each preferably 100 angstroms or less, more preferably 60 angstroms or less, even more preferably 40 angstroms or less, and each 10 angstroms to 40 angstroms. Most preferably, it is in the angstrom range. If the film thickness of the n-side first layer and / or the n-side second layer forming the superlattice layer is more than 100 angstroms, crystal defects are likely to occur, which is not preferable.

  Each of the n-side first layer and the n-side second layer may have a doped structure, or a combination of a doped structure / undoped structure. As the impurity to be doped, conventionally known impurities can be applied to the material composition without any limitation. For example, in the case where a superlattice structure having an alternate structure of GaInN / GaN or an alternate structure of GaInN / GaInN having a different composition is used as the n-clad layer 12b, Si is suitable as an impurity. Further, the n-side first layer and the n-side second layer constituting the superlattice structure have the same composition represented by GaInN, AlGaN, and GaN, and are a combination of a doped structure and an undoped structure. Also good.

<Light emitting layer 13>
The light emitting layer 13 has a multiple quantum well structure in which a plurality of barrier layers 13a and well layers 13b are alternately stacked. The number of stacked layers in the multiple quantum well structure is preferably 3 to 10 layers, more preferably 4 to 7 layers.

(Well layer 13b)
The thickness of the well layer 13b is preferably in the range of 15 angstroms or more and 50 angstroms or less. When the thickness of the well layer 13b is within the above range, higher light output can be obtained.
The well layer 13b is preferably a gallium nitride compound semiconductor containing In. A gallium nitride compound semiconductor containing In is preferable because it emits strong light in the blue wavelength region. The well layer 13b can be doped with impurities. As the dopant, it is preferable to use Si or Ge which enhances the emission intensity. The dope amount is preferably about 1 × 10 ¹⁷ cm ⁻³ to 1 × 10 ¹⁸ cm ⁻³ . When the doping amount is in the above range, the emission intensity is stronger.

(Barrier layer 13a)
The thickness of the barrier layer 13a is preferably in the range of 20 angstroms or more and less than 100 angstroms. If the thickness of the barrier layer 13a is too thin, flattening of the upper surface of the barrier layer 13a is hindered, resulting in a decrease in light emission efficiency and a decrease in aging characteristics. Moreover, when the film thickness of the barrier layer 13a is too thick, a drive voltage rises and light emission falls. Therefore, the thickness of the barrier layer 13a is more preferably 70 angstroms or less.
In addition to GaN and AlGaN, the barrier layer 13a can be formed of InGaN having a smaller In ratio than InGaN constituting the well layer. Among these, GaN is preferable.

<P-type semiconductor layer 14>
The p-type semiconductor layer 14 is generally composed of a p-cladding layer 14a and a p-contact layer 14b. Further, the p contact layer 14b can also serve as the p clad layer 14a.

(P-clad layer 14a)
The p-cladding layer 14a is a layer for confining carriers in the light emitting layer 13 and injecting carriers. The p-cladding layer 14a is not particularly limited as long as it has a composition larger than the band gap energy of the light-emitting layer 13 and can confine carriers in the light-emitting layer 13, but Al _x Ga _1-x N (0 < x ≦ 0.4) is preferable. When the p-cladding layer 14a is made of such AlGaN, it is preferable in terms of confining carriers in the light-emitting layer 13.

The thickness of the p-cladding layer 14a is not particularly limited, but is preferably 1 to 400 nm, and more preferably 5 to 100 nm. The p-type doping concentration of the p-cladding layer 14a is preferably 1 × 10 ¹⁸ to 1 × 10 ²¹ / cm ³ , more preferably 1 × 10 ¹⁹ to 1 × 10 ²⁰ / cm ³ . When the p-type dope concentration is in the above range, a good p-type crystal can be obtained without reducing the crystallinity. The p-cladding layer 14a may have a superlattice structure in which thin films are stacked a plurality of times.

  When the p-cladding layer 14a includes a superlattice structure, a p-side first layer made of a group III nitride semiconductor and a p-side second made of a group III nitride semiconductor having a composition different from that of the p-side first layer. The layers may be stacked. When the p-cladding layer 14a includes a superlattice structure, the p-cladding layer 14a may include a structure in which p-side first layers and p-side second layers are alternately and repeatedly stacked.

  The p-side first layer and the p-side second layer constituting the superlattice structure of the p-cladding layer 14a may have different compositions, for example, any composition of AlGaN, GaInN, or GaN. GaInN / GaN Alternatively, an alternate structure of AlGaN / GaN, or an alternate structure of GaInN / AlGaN may be used. In the present invention, the p-side first layer and the p-side second layer preferably have an AlGaN / AlGaN or AlGaN / GaN alternating structure.

  The thicknesses of the p-side first layer and the p-side second layer are each preferably 100 angstroms or less, more preferably 60 angstroms or less, even more preferably 40 angstroms or less, and each 10 angstroms to 40 angstroms. Most preferably, it is in the angstrom range. If the thickness of the p-side first layer and the p-side second layer forming the superlattice layer is more than 100 angstroms, crystal defects are likely to occur, which is not preferable.

  Each of the p-side first layer and the p-side second layer may have a doped structure, or a combination of a doped structure and an undoped structure. As the impurity to be doped, conventionally known impurities can be applied to the material composition without any limitation. For example, when a superlattice structure having an AlGaN / GaN alternating structure or an AlGaN / AlGaN alternating structure having a different composition is used as the p-cladding layer, Mg is suitable as the impurity. Further, the p-side first layer and the p-side second constituting the superlattice structure have the same composition represented by GaInN, AlGaN, and GaN, and may be a combination of a doped structure / undoped structure. Good.

(P contact layer 14b)
The p contact layer 14b is a layer for providing a positive electrode. The p contact layer 14b is preferably made of Al _x Ga _1-x N (0 ≦ x ≦ 0.4) in terms of maintaining good crystallinity and good ohmic contact with the p ohmic electrode. . When the p-contact layer 14b contains p-type impurities (dopants) at a concentration of 1 × 10 ¹⁸ to 1 × 10 ²¹ / cm ³ and 5 × 10 ^{19 to} 5 × 10 ²⁰ / cm ^3. From the viewpoint of maintaining good ohmic contact, preventing the occurrence of cracks, and maintaining good crystallinity. Although it does not specifically limit as a p-type impurity, For example, it is preferable to use Mg. The thickness of the p contact layer 14b is not particularly limited, but is preferably 10 to 500 nm, and more preferably 50 to 200 nm. When the film thickness of the p contact layer 14b is within this range, it is preferable in terms of light emission output.

<N-type electrode 17>
The n-type electrode 17 also serves as a bonding pad, and is formed in contact with the n-type semiconductor layer 12 of the laminated semiconductor layer 20. Therefore, when forming the n-type electrode 17, at least a part of the p-semiconductor layer 14 and the light-emitting layer 13 is removed to expose the n-type semiconductor layer 12, and on the exposed surface 20 a of the n-type semiconductor layer 12. An n-type electrode 17 also serving as a bonding pad is formed. As the n-type electrode 17, various compositions and structures are known, and these known compositions and structures can be used without any limitation, and can be provided by conventional means well known in this technical field.

(Translucent electrode 15)
The translucent electrode 15 is laminated on the p-type semiconductor layer 14 and preferably has a small contact resistance with the p-type semiconductor layer 14. Further, the translucent electrode 15 is preferably excellent in light transmissivity in order to efficiently extract light from the light emitting layer 13 to the outside of the semiconductor light emitting element 1. In addition, the translucent electrode 15 preferably has excellent conductivity in order to diffuse current uniformly over the entire surface of the p-type semiconductor layer 14.

As a constituent material of the translucent electrode 15, any one of conductive oxide containing any one of In, Zn, Al, Ga, Ti, Bi, Mg, W, and Ce, zinc sulfide, or chromium sulfide is used. A translucent conductive material selected from the group consisting of: As the conductive oxide, ITO (indium tin oxide (In ₂ O ₃ —SnO ₂ )), IZO (indium zinc oxide (In ₂ O ₃ —ZnO)), AZO (aluminum zinc oxide (ZnO—Al ₂ O)) ₃ )), GZO (gallium zinc oxide (ZnO—Ga ₂ O ₃ )), fluorine-doped tin oxide, titanium oxide and the like.

  Moreover, the structure of the translucent electrode 15 may be any structure including a conventionally known structure. The translucent electrode 15 may be formed so as to cover almost the entire surface of the p-type semiconductor layer 14, or may be formed in a lattice shape or a tree shape with a gap.

(P-type bonding pad electrode 16)
The p-type bonding pad electrode 16 also serves as a bonding pad, and is laminated on the translucent electrode 15. As the p-type bonding pad electrode 16, various compositions and structures are known, and these known compositions and structures can be used without any limitation, and can be provided by conventional means well known in this technical field.
The p-type bonding pad electrode 16 can be formed anywhere as long as it is on the translucent electrode 15. For example, it may be formed at a position farthest from the n-type electrode 17 or may be formed at the center of the semiconductor light emitting device 1. However, if it is formed at a position too close to the n-type electrode 17, it is not preferable because a short circuit between wires and balls occurs when bonding.

  Also, the electrode area of the p-type bonding pad electrode 16 is as large as possible to facilitate the bonding operation, but it prevents the emission of light emission. For example, when a large area exceeding half of the area of the chip surface is covered, the extraction of light emission is hindered, and the output is significantly reduced. Conversely, if the electrode area of the p-type bonding pad electrode 16 is too small, the bonding operation becomes difficult and the product yield is reduced. Specifically, it is preferably slightly larger than the diameter of the bonding ball, and generally has a circular shape with a diameter of 100 μm.

(Protective film layer)
The protective film layer (not shown) includes the upper surface and side surfaces of the translucent electrode 15, the exposed surface 20a of the n-type semiconductor layer 12, the side surfaces of the light-emitting layer 13 and the p-type semiconductor layer 14, the n-type electrodes 17 and p as required. It is formed so as to cover the side surface and the peripheral portion of the mold bonding pad electrode 16. By forming the protective film layer, it is possible to prevent moisture and the like from entering the semiconductor light emitting element 1 and to suppress the deterioration of the semiconductor light emitting element 1.
As the protective film layer, it is preferable to use an insulating material having a transmittance of 80% or more at a wavelength in the range of 300 to 550 nm. For example, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), tantalum oxide (Ta ₂ O ₅ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), or the like can be used. Among these, SiO ₂ and Al ₂ O ₃ are more preferable because a dense film can be easily formed by CVD film formation.

Hereinafter, a method for manufacturing the semiconductor light emitting device 1 will be described in detail with reference to the drawings as appropriate.
The drawings referred to in the following description are for explaining the present invention, and the size, thickness, dimensions, and the like of each part shown in the drawings are different from the actual dimensional relationship of the semiconductor light emitting device 1.

  In the manufacturing method of the semiconductor light emitting device 1 shown in FIG. 1 of the present invention, first, the laminated semiconductor layer 20 shown in FIG. 2 is manufactured. The method for manufacturing the stacked semiconductor layer 20 includes a first step of stacking the first n-type semiconductor layer 12c on the substrate 11, a regrowth layer 12d of the first n-type semiconductor layer 12c on the first n-type semiconductor layer 12c, The n-cladding layer 12b (second n-type semiconductor layer), the light-emitting layer 13, and the p-type semiconductor layer 14 are sequentially stacked, and the second step is then schematically configured. Hereafter, each process is demonstrated in detail using FIG.

<First step>
First, a substrate 11 made of sapphire or the like is prepared.
Next, the substrate 11 is placed in a growth chamber of a first MOCVD apparatus (first metal organic chemical vapor deposition apparatus), and a buffer layer 21 and a base layer 22 are sequentially stacked on the substrate 11 by MOCVD.

(First process growth layer 12c (first n-type semiconductor layer) stacking process)
Next, a first process growth layer 12 c (first n-type semiconductor layer) that constitutes a part of the n contact layer 12 a is laminated on the base layer 22. At this time, the film thickness of the first step growth layer 12c is preferably 0.5 to 5 μm, and particularly preferably 2 to 4 μm. This is because the crystallinity of the semiconductor can be favorably maintained by forming it within the above range.

Moreover, when growing the 1st process growth layer 12c, it is preferable to make the temperature of the board | substrate 11 into the range of 1000 to 1100 degreeC by hydrogen atmosphere.
In addition, as a raw material for growing the first process growth layer 12c, a group III metal organic metal raw material such as trimethylgallium (TMG) and a nitrogen raw material such as ammonia (NH ₃ ) are used, and thermally decomposed on the buffer layer. A group III nitride semiconductor layer is deposited. The pressure in the growth chamber of the MOCVD apparatus is preferably 15 to 80 kPa, and more preferably 15 to 60 kPa. The carrier gas may be only hydrogen gas or a mixed gas of hydrogen gas and nitrogen gas.

  Thereafter, the substrate 11 on which each layer from the growth chamber of the first metal organic chemical vapor deposition apparatus (first MOCVD apparatus) to the first process growth layer 12c of the n contact layer 12a is formed is taken out.

<Second step>
The second step further includes a step of forming a regrown layer 12d of the first n-type semiconductor layer 12c on the first n-type semiconductor layer 12c, and a step of forming an n-clad layer 12b (second n-type semiconductor layer). , And the step of forming the light emitting layer 13 and the step of forming the p-type semiconductor layer 14. Details will be described below.

(Step of forming regrowth layer 12d)
First, the substrate 11 on which the layers up to the first process growth layer 12c are formed is placed in a growth chamber of a second metal organic chemical vapor deposition apparatus (second MOCVD apparatus). Next, a regrowth layer 12d of the n contact layer 12a is formed on the first process growth layer 12c by MOCVD.

  In this embodiment, before forming the regrowth layer 12d, the substrate 11 on which the layers up to the first step growth layer 12c are formed is subjected to a heat treatment temperature of 500 ° C. to 1000 ° C. in an atmosphere containing nitrogen and ammonia, preferably It is preferable to perform heat treatment (thermal cleaning) at 900 ° C. to 950 ° C. The atmosphere of the heat treatment may be, for example, an atmosphere containing only nitrogen instead of the atmosphere containing nitrogen and ammonia. Note that, in an atmosphere containing only hydrogen, the first process growth layer 12c is sublimated, and crystallinity is deteriorated. Further, the pressure in the growth chamber of the MOCVD apparatus at this time is preferably 15 to 100 kPa, and more preferably 60 to 95 kPa.

When such a heat treatment is performed, the substrate 11 on which each layer up to the first process growth layer 12c of the n contact layer 12a is formed is taken out from the growth chamber of the first metal organic chemical vapor deposition apparatus after the first process is completed. Thus, even if the surface of the first process growth layer 12c is contaminated, the contaminant can be removed before the regrowth layer 12d is formed. As a result, the crystallinity of the regrowth layer 12d is improved, and the crystallinity of the n-clad layer 12b and the light emitting layer 13 formed on the regrowth layer 12d is further improved.
If the surface of the first process growth layer 12c remains contaminated, the reverse current (IR) may not be sufficiently low, or the electrostatic discharge (ESD) withstand voltage may be insufficient. The reliability of 1 is reduced.

  In the present embodiment, the regrowth layer 12d is formed by supplying a dopant gas containing Mg together with the source gas of the regrowth layer 12d into the second metal organic chemical vapor deposition apparatus. The supply of the dopant gas does not need to be continued until the formation of the regrowth layer 12d is completed. It is desirable that the supply is started simultaneously with the start of the formation of the regrowth layer 12d and the supply is stopped during the formation of the regrowth layer 12d.

  In addition, when the deposition rate of the regrowth layer 12d is constant, the time for supplying the dopant gas containing Mg is equivalent to 1/10 to 2/3 of the entire deposition time of the regrowth layer 12d. It is more desirable to do. That is, from the first stage of film formation of the regrowth layer 12d, the dopant gas is supplied for 1/10 to 2/3 of the entire film formation time, and after stopping the dopant gas, the source gas of the regrowth layer 12d Only supply.

  At this time, if the supply time of the dopant gas is less than 1/10 of the entire film formation time of the regrowth layer 12d, the effect of the Mg-containing portion cannot be sufficiently obtained, so that the surface of the regrowth layer 12d is sufficiently Not flattened. Further, if the supply time of the dopant gas exceeds 2/3 of the entire film formation time of the regrowth layer 12d, the driving voltage Vf when a current is passed through the regrowth layer 12d increases, and therefore the semiconductor element 1 The light output is lowered.

  Thereby, Mg is contained in at least a portion near the substrate 11 of the regrowth layer 12d, and the surface on the light emitting layer 13 side of the regrowth layer 12d is formed flat compared to the conventional manufacturing method.

Further, the concentration of Mg contained in the portion near the substrate 11 of the regrowth layer 12d is desirably 1 × 10 ¹⁷ to 1 × 10 ¹⁹ / cm ³ . If the Mg concentration is less than 1 × 10 ¹⁷ , the effect of the Mg-containing portion cannot be sufficiently obtained, and the surface of the regrowth layer 12d is not sufficiently flattened. On the other hand, when the Mg concentration exceeds 1 × 10 ¹⁹ , the drive voltage Vf when a current is passed increases, and the regrowth layer 12d becomes p-type, so that the light emission output of the semiconductor element 1 decreases. .

Moreover, in this embodiment, it is preferable to form the regrowth layer 12d with a film thickness of 0.1 μm to 1 μm. If the film thickness of the regrowth layer 12d is less than 0.1 μm, the planarization effect due to the Mg-containing portion cannot be sufficiently obtained, and thus the surface of the regrowth layer 12d on the light emitting layer 13 side is not sufficiently planarized.
On the other hand, when the film thickness of the regrowth layer 12d is 0.1 μm or more, the planarization effect due to the Mg-containing portion appears sufficiently, so that the surface of the regrowth layer 12d on the light emitting layer 13 side is planarized.

  Moreover, when the film thickness of the regrowth layer 12d exceeds 1 μm, the amount of dopants and deposits left after forming the n-type semiconductor layer 12 in the growth chamber of the second organometallic chemical vapor deposition apparatus increases. Defects in the p-type semiconductor layer 14 due to dopants and deposits are likely to occur. For this reason, the film formation processing time for the regrowth layer 12d becomes long, and the productivity of the semiconductor light emitting device 1 decreases.

  Further, when the regrowth layer 12d is grown, the temperature of the substrate 11 is preferably set in the range of 1000 ° C. to 1100 ° C. By setting the temperature of the substrate 11 when the regrowth layer 12d is grown within the above range, the substrate 11 on which the layers up to the first process growth layer 12c are formed becomes the growth chamber of the first metal organic chemical vapor deposition apparatus. Thus, even if the surface of the first process growth layer 12c of the n-contact layer 12a is contaminated, the contaminant can be removed when forming the regrowth layer 12d.

  As a result, the crystallinity of the n-clad layer 12b and the light emitting layer 13 formed on the regrown layer 12d in the process described later can be made even better. On the other hand, if the temperature of the substrate 11 when the regrowth layer 12d is grown is less than 1000 ° C., the reverse current (IR) does not become sufficiently low or the electrostatic discharge (ESD) breakdown voltage is insufficient. There is a fear. Further, if the temperature of the substrate 11 when the regrowth layer 12d is grown exceeds 1100 ° C., the output of the semiconductor light emitting element 1 may be insufficient.

(Process for forming n-clad layer 12b (second n-type semiconductor layer))
Next, an n-clad layer 12b having a superlattice structure is formed on the regrowth layer 12d.
First, an n-side first layer (not shown) made of a group III nitride semiconductor having a thickness of 100 angstroms or less, and an n-side made of a group III nitride semiconductor having a thickness of 100 angstroms or less having a different composition from the n-side first layer. The second layer and the second layer are alternately stacked repeatedly in the number of 10 pairs (20 layers) to 40 pairs (80 layers).

(Light emitting layer 13 formation process)
Next, the light emitting layer 13 having a multiple quantum well structure is formed. First, the well layers 13b and the barrier layers 13a are alternately and repeatedly stacked. At this time, it is preferable to laminate so that the barrier layer 13a is arranged on the n-type semiconductor layer 12 side and the p-type semiconductor layer 14 side.
The composition and film thickness of the well layer 13b and the barrier layer 13a can be appropriately set so as to have a predetermined emission wavelength. Moreover, the growth temperature of the light emitting layer 13 can be 600-900 degreeC, and nitrogen gas can be used as carrier gas.

(P-type semiconductor layer 14 forming step)
The p-type semiconductor layer 14 may be formed by sequentially stacking a p-cladding layer 14a and a p-contact layer 14b. When the p-cladding layer 14a is a layer including a superlattice structure, a p-side first layer made of a group III nitride semiconductor having a thickness of 100 angstroms or less and a film having a composition different from that of the p-side first layer are used. What is necessary is just to laminate | stack repeatedly the p side 2nd layer which consists of a group III nitride semiconductor below thickness 100angstrom alternately.
As described above, the laminated semiconductor layer 20 shown in FIG. 2 is manufactured.

Thereafter, the translucent electrode 15 is laminated on the p-type semiconductor layer 14 of the laminated semiconductor layer 20, and the translucent electrode 15 other than the predetermined region is removed by, for example, a generally known photolithography technique.
Subsequently, patterning is performed by, for example, a photolithography technique, and a part of the laminated semiconductor layer 20 in a predetermined region is etched to expose a part of the first process growth layer 12c of the n contact layer 12a, and the n contact layer 12a. An n-type electrode 17 is formed on the exposed surface 20a.
Thereafter, a p-type bonding pad electrode 16 is formed on the translucent electrode 15.
As described above, the semiconductor light emitting device 1 shown in FIG. 1 is manufactured.

According to the method for manufacturing the semiconductor light emitting device 1 of this embodiment, when forming the regrowth layer 12d in the second step, at least the substrate of the regrowth layer 12d is supplied by supplying a dopant gas containing Mg together with the source gas. Mg is doped in the close part. Thereby, even if the regrowth layer 12d is formed at a high temperature of 1000 ° C. to 1100 ° C., the flatness of the surface can be prevented from deteriorating. Therefore, the regrown layer 12d having high crystallinity can be obtained, and the surface of the regrown layer 12d on the light emitting layer 13 side can be formed flat.
Further, in this embodiment, by stopping the supply of the dopant gas in the middle of the formation of the regrowth layer 12d, Mg can be included only in the portion of the regrowth layer 12d that is closer to the substrate. For this reason, the same effect can be obtained while suppressing an increase in the driving voltage Vf when a current is passed through the semiconductor element 1.

As a result, the n-cladding layer 12b with good crystallinity can be formed on the regrown layer 12d, and the light-emitting layer 13 with good crystallinity can be formed on the n-cladding layer 12b.
Accordingly, the semiconductor light emitting device 1 having a sufficiently low reverse current (IR) and a high light emission output (Po) can be obtained. Moreover, it becomes possible to prevent the defect of the semiconductor light emitting element 1 and improve the LED chip yield within the standard.

<Lamp 3>
The lamp 3 of this embodiment includes the semiconductor light emitting device 1 of the present invention, and is a combination of the semiconductor light emitting device 1 and a phosphor. The lamp 3 of the present embodiment can have a configuration well known to those skilled in the art by means well known to those skilled in the art. For example, in the lamp 3 of this embodiment, a technique for changing the emission color by combining the semiconductor light emitting element 1 and the phosphor can be adopted without any limitation.

  FIG. 3 is a schematic cross-sectional view showing an example of a lamp including the semiconductor light emitting element 1 shown in FIG. The lamp 3 shown in FIG. 3 is a shell type, and the semiconductor light emitting element 1 shown in FIG. 1 is used. As shown in FIG. 3, the p-type bonding pad electrode 16 of the semiconductor light emitting device 1 is connected to one of the two frames 31 and 32 (the frame 31 in FIG. 3) by a wire 33. The semiconductor light emitting element 1 is mounted by connecting the mold electrode 17 (bonding pad) to the other frame 32 with a wire 34. Further, the periphery of the semiconductor light emitting element 1 is sealed with a mold 35 made of a transparent resin.

  Since the lamp 3 of the present embodiment uses the semiconductor light emitting element 1 described above, a high light emission output can be obtained.

  In addition, electronic devices such as backlights, mobile phones, displays, various panels, computers, game machines, and lighting incorporating the lamp 3 of the present embodiment, and mechanical devices such as automobiles incorporating such electronic devices are expensive. The semiconductor light emitting device 1 capable of obtaining a light emission output is provided. In particular, an electronic device driven by a battery such as a backlight, a mobile phone, a display, a game machine, and an illumination is preferable because an excellent product including the semiconductor light emitting element 1 that can obtain a high light emission output can be provided.

Hereinafter, the method for producing a semiconductor light emitting device of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
Example 1
The semiconductor light emitting device 1 shown in FIG. 1 was manufactured by the following method.
In the semiconductor light emitting device 1 of Example 1, a buffer layer 21 made of AlN, a base layer 22 made of undoped GaN having a thickness of 5 μm, and a first layer made of Si-doped n-type GaN having a thickness of 3 μm are formed on a substrate 11 made of sapphire. A process growth layer 12c, and a regrowth layer 12d made of n-type GaN having a thickness of 0.6 μm doped with Mg at a concentration of 1 × 10 ¹⁸ / cm ³ over a thickness of 0.2 μm as shown in Table 1. Table 1 shows a thin film layer consisting of a 3.6 μm thick n-contact layer 12a, a 2 nm thick n-side first layer made of GaInN, and a 2 nm thick n-side second layer made of GaN. An n-cladding layer 12b having a superlattice structure having a thickness of 80 nm, a Si-doped GaN barrier layer having a thickness of 5 nm, and an In0.15Ga0.85N well having a thickness of 3.5 nm. The stacked six times, finally emitting layer 13 of multiple quantum well structure in which a barrier layer, p-cladding layer 14a made of thick 10 nm Mg-doped monolayers Al _0.07 Ga _0.93 N, a thickness of 150 nm Mg-doped p-type A p-contact layer 14b made of GaN was sequentially stacked.

  In the semiconductor light emitting device 1 of Example 1, the buffer layer 21, the base layer 22, and the first process growth layer 12c are stacked using a first metal organic chemical vapor deposition apparatus (first MOCVD apparatus) (first MOCVD apparatus). Process), and the regrowth layer 12d, the n-clad layer 12b, the light-emitting layer 13, the p-clad layer 14a, and the p-contact layer 14b are stacked using a second metal organic chemical vapor deposition apparatus (second MOCVD apparatus). Two steps). The regrown layer 12d was formed under the growth conditions shown below.

“Growth conditions for regrowth layer 12d”
The regrowth layer 12d is deposited on the first-step growth layer 12c using a group III metal organometallic material of trimethylgallium (TMGa) and a nitrogen material such as ammonia (NH ₃ ). Monosilane (SiH ₄ ) was used for n-type doping, and biscyclopentadienylmagnesium (Cp ₂ Mg) was used as the Mg raw material. The Mg flow rate was adjusted to a predetermined concentration.
When the regrowth layer 12d was grown, the pressure in the MOCVD growth furnace was 40 kPa, the temperature of the substrate 11 was 1080 ° C., and the carrier gas was all hydrogen.

Thereafter, a translucent electrode 15 made of ITO having a thickness of 200 nm was formed on the p-contact layer 14b by a generally known photolithography technique.
Next, etching was performed using a photolithography technique to form an exposed surface 20a of the n contact layer 12a in a desired region, and an n-type electrode 17 having a Ti / Au double layer structure was formed thereon.
Further, on the translucent electrode 15, a p-type bonding pad structure 16 having a three-layer structure composed of a metal reflective layer made of 200 nm Al, a barrier layer made of 80 nm Ti, and a bonding layer made of 1100 nm Au, It formed using the technique of photolithography.
As described above, the semiconductor light emitting device 1 of Example 1 shown in FIG. 1 was obtained.

In the semiconductor light emitting device 1 of Example 1 obtained in this way, the regrowth layer 12d is formed with a thickness of 0.6 μm, the Mg-containing portion is 0.2 μm in thickness, and its concentration is 1 × 10 ¹⁸ cm ^3. The characteristics of the semiconductor light emitting device 1 were the forward voltage Vf = 3.1 V, the light emission output Po = 24 mW, and the reverse current IR (@ 20 V) = 0.5 μA.

(Example 2)
A semiconductor light emitting device was prepared by performing the same operation as in Example 1, except that the thickness of the Mg-containing portion of the regrowth layer 12d in Example 1 was changed to 0.4 μm and the Mg-containing concentration was changed to 1 × 10 ¹⁷ / cm ^3. The characteristics as 1 were the forward voltage Vf = 3.1 V, the light emission output Po = 23 mW, and the reverse current IR (@ 20 V) = 0.9 μA.

(Example 3)
Except for changing the thickness of the regrowth layer 12d of Example 1 to 1 μm and changing the Mg content concentration to 1 × 10 ¹⁷ / cm ³ , the same operation as in Example 1 was performed, and the characteristics as the semiconductor light emitting device 1 were as follows. The forward voltage Vf was 3.0 V, the light emission output Po was 25 mW, and the reverse current IR (@ 20 V) was 0.4 μA.

Example 4
Except for changing the thickness of the regrowth layer 12d in Example 1 to 1 μm and the thickness of the Mg-containing portion to 0.1 μm, the same operation as in Example 1 was performed, and the characteristics as the semiconductor light emitting element 1 were as follows: The forward voltage Vf was 3.0 V, the light emission output Po was 25 mW, and the reverse current IR (@ 20 V) was 0.3 μA.

(Example 5)
The same as Example 1 except that the thickness of the regrowth layer 12d in Example 1 was changed to 0.2 μm, the thickness of the Mg-containing portion was changed to 0.1 μm, and the Mg-containing concentration was changed to 1 × 10 ¹⁷ / cm ^3. The characteristics of the semiconductor light emitting device 1 were as follows: forward voltage Vf = 3.2 V, light emission output Po = 23 mW, reverse current IR (@ 20 V) = 0.2 μA.

(Comparative Example 1)
The thickness of the regrowth layer 12d of Example 1 is changed to 0.6 μm, the thickness of the Mg-containing portion is changed to 0 μm (not containing Mg), and the Mg-containing concentration is changed to less than the detection lower limit (1 × 10 ¹⁷ / cm ^3). Except for the above, the same operation as in Example 1 was performed, and the characteristics as the semiconductor light emitting element 1 were the forward voltage Vf = 3.2 V, the light emission output Po = 21 mW, and the reverse current IR (@ 20 V) = 10 μA. It was.

  The forward voltage Vf for the semiconductor light emitting devices 1 of the example and the comparative example is a voltage measured at a current application value of 20 mA by energization with a probe needle. Similarly, the light emission output (Po) for the semiconductor light emitting devices 1 of the example and the comparative example is mounted on a TO-18 can package, and is a light emission output at an applied current of 20 mA by a tester.

The reverse current (IR) is a value obtained by measuring a leakage current when 20 V is applied to the light emitting element in the reverse direction. The electrostatic discharge (ESD) breakdown voltage was measured according to the EIAJED-470 (HMM) test method 304 human body model electrostatic breakdown test method.
Table 1 shows the results of forward voltage, light emission output (Po), and reverse current (IR) of the semiconductor light emitting devices of Examples 1 to 5 and Comparative Example 1.

As shown in Table 1, each of the semiconductor light emitting devices 1 of Examples 1 to 5 has a sufficiently low reverse current (IR), a relatively low forward voltage, and a light emission output (Po) of 20 mW or more. Thus, the brightness was high and the power consumption was low.
On the other hand, Comparative Example 1 in which the thickness of the regrowth layer 12d is 0.6 μm, does not have the thickness of the Mg-containing portion (0 μm), and the Mg-containing concentration is the detection lower limit (1 × 10 ¹⁷ / cm ³ or less). Then, as compared with Examples 1 to 5, the light emission output (Po) was low, the forward voltage was relatively high, and the leakage current (reverse current (IR) was large.

  As described above, the semiconductor light-emitting elements 1 of Examples 1 to 5 can effectively improve the light-emission output, and the light-emission output has a smaller leakage current and a higher light output than the semiconductor light-emitting element 1 of Comparative Example 1. It was confirmed that it was obtained.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor light-emitting device, 3 ... Lamp, 12 ... n-type semiconductor layer, 12a ... n contact layer, 12b ... n clad layer (2nd n-type semiconductor layer), 12c ... 1st process growth layer (1st n-type semiconductor) Layer), 12d ... regrowth layer, 13 ... light emitting layer, 14 ... p-type semiconductor layer

Claims (11)

In the first organometallic chemical vapor deposition apparatus, a first step of laminating a first n-type semiconductor layer on a substrate;
In the second organometallic chemical vapor deposition apparatus, a regrowth layer of the first n-type semiconductor layer, a second n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer are sequentially stacked on the first n-type semiconductor layer. And a second step to
In the second step, Mg is doped when the regrowth layer is formed. A method for manufacturing a semiconductor light emitting device.   2. The method of manufacturing a semiconductor light emitting device according to claim 1, wherein the regrowth layer is formed by supplying a dopant gas containing Mg together with a source gas of the regrowth layer.   3. The method of manufacturing a semiconductor light emitting device according to claim 2, wherein the supply of the dopant gas is started simultaneously with the start of the formation of the regrowth layer, and the supply is stopped during the formation of the regrowth layer.    4. The method of manufacturing a semiconductor light emitting device according to claim 3, wherein the time for supplying the dopant gas is 1/10 to 2/3 of the entire time for forming the regrowth layer. 5.   2. The method of manufacturing a semiconductor light emitting element according to claim 1, wherein the substrate temperature when forming the regrowth layer is 1000 ° C. to 1100 ° C. 3. 2. The method of manufacturing a semiconductor light emitting element according to claim 1, wherein the Mg is contained at a concentration of 1 × 10 ¹⁷ to 1 × 10 ¹⁹ / cm ³ in a portion near the substrate in the regrown layer.   The method of manufacturing a semiconductor light emitting element according to claim 1, wherein the regrowth layer has a thickness of 0.1 μm to 1 μm. A semiconductor light emitting device in which a first n type semiconductor layer, a regrowth layer of the first n type semiconductor layer, a second n type semiconductor layer, a light emitting layer, and a p type semiconductor layer are stacked on a substrate,
Wherein Mg is contained at least in the substrate side of the portion of the regrown layer, the thickness of the portion containing the Mg is characterized by one / 10-2 / 3 der Rukoto thickness of the regrown layer Semiconductor light emitting device.   A lamp comprising a semiconductor light emitting device manufactured using the method for manufacturing a semiconductor light emitting device according to claim 1. An electronic device comprising the lamp according to claim 9 incorporated therein. Mechanical apparatus characterized by the electronic device is incorporated according to claim 1 0.

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