JP2005340231A - Semiconductor light emitting element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light emitting element which realizes a light emission of desired tone having strong light emission intensity without arising an increase in an operating voltage or particularly a light emission including a red color or a light emission of white color by a simple method. <P>SOLUTION: This semiconductor light emitting element 10 includes a sapphire substrate 11, a ground layer 12 made of a GaN, an n-type contact layer 13 made of the GaN, an n-type clad layer 14 made of n-type Al<SB>0.15</SB>Ga<SB>0.85</SB>N, a light emitting layer 15 made of a quantum well structure where In<SB>0.15</SB>Ga<SB>0.85</SB>N well layer and a GaN barrier layer are alternately laminated in 3 periods, a p-type clad layer 16 made of a p-type Al<SB>0.15</SB>Ga<SB>0.85</SB>N, a p-type contact layer 17 made of a p-type GaN, and a rare earth element-doped layer 18 made of GaN doped with Eu of rare earth element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor light emitting device and a method for manufacturing the same, and more particularly to a semiconductor light emitting device that can be suitably used as a white light emitting diode and the like and a method for manufacturing the same.

In general, a white light illuminating device includes, for example, a phosphor and a light emitting element that excites the phosphor as disclosed in Patent Document 1. Specifically, a light-emitting element made of a nitride semiconductor represented by the general formula Al _x Ga _1-x N (where x is 0 ≦ x ≦ 1) cut to 1 mm square or less, and the light-emitting element A phosphor that emits light having a wavelength having an emission peak near 570 nm when excited by blue light emitted from the light source, a metal stem that holds the light emitting element, and a resin mold that surrounds the light emitting element and is filled with the phosphor. I have. Since the light from the illumination device is a mixture of blue light emitted from the light emitting element and yellow light emitted from the phosphor, the observer perceives it as white light.

Furthermore, as a method different from the above, there is a method described in Patent Document 2. In this method, as shown in FIG. 4, a p-type cladding layer 45 adjacent to the light emitting layer 44 of the semiconductor light emitting device 40 is doped with a rare earth element, and the rare earth element is excited by light emitted from the light emitting layer 44 to emit fluorescence. As a result, white light can be realized by the mixed color of the light emission from the light emitting layer 44 and the fluorescence from the rare earth element. The constituent elements of the semiconductor light emitting device 40 other than the light emitting layer 44 and the p-type cladding layer 45 are the sapphire substrate 41, the n-type contact layer 42, the n-type cladding layer 43, the p-type contact layer 46, the n-side electrode 47, This is a p-side electrode 48.
JP-A-5-152606 JP 2002-231995 A

  However, in the case of the conventional structure in which the above resin mold is filled with a phosphor, the red light component is weak and the color rendering property is poor. In other words, when white light hits a red substance, it looks a little orange, so in order to use such white light in a backlight, the color filter must be devised.

  Furthermore, there is a problem that the color of white light changes very sensitively depending on the thickness of the phosphor. For example, when the thickness of the phosphor is too thin, blue light emitted from a light emitting diode (hereinafter referred to as LED) passes through the phosphor in an amount greater than a desired amount. As a result, the blue light of the LED is more dominant than the yellow light of the phosphor, so that the combined light output of the LED and the phosphor appears bluish. On the other hand, when the phosphor is too thick, the amount of blue light emitted from the LED is transmitted through the phosphor layer is less than the desired amount. As a result, since the yellow light of the phosphor is dominant over the blue light of the LED, the combined light output of the LED and the phosphor appears yellowish. Thus, the thickness of the phosphor is an important variable that affects the combined light output of the LED and the phosphor, and the variation in the phosphor thickness is white light that is not suitable for white light illumination applications (bluish) Color or yellowish color). However, since it is difficult to precisely control the thickness of the phosphor when producing a white light illumination device on a large scale, the manufacturing yield may be unacceptably low.

  On the other hand, in the case of a conventional structure in which a cladding layer adjacent to a light emitting layer of a semiconductor light emitting element is doped with a rare earth element, it is necessary to pass a current through the cladding layer in order to generate fluorescence from the rare earth element by light emission from the light emitting layer. . In this case, if the cladding layer is doped with a rare earth element, there is a problem in that the operating voltage is increased as the crystallinity decreases.

  The object of the present invention is to solve the above-mentioned conventional problems, and in a simple method, semiconductor light emission that realizes light emission of an arbitrary color with a strong light emission intensity without causing an increase in operating voltage, particularly light emission of white light. The object is to provide an element and a method of manufacturing the same.

  The semiconductor light emitting device of the present invention includes a light emitting layer, a cladding layer adjacent to the light emitting layer, and a semiconductor layer provided above the cladding layer and including a rare earth element at least partially.

  In such a semiconductor light emitting device, when a rare earth element contained in the semiconductor layer is excited by light from the light emitting layer, fluorescence having a wavelength unique to the element is emitted. That is, light emission having a desired color can be realized by appropriately selecting a rare earth element and introducing it into the semiconductor layer. The conventional white light emitting device has a disadvantage that the red light component is weak, but in the present invention, the red component can be supplemented by selecting a rare earth element that emits red light. In addition, the conventional white light emitting device has a problem that the hue of white light is likely to change depending on the thickness of the phosphor. However, in the present invention, since the phosphor does not have to be used, stable white light can be obtained. Can be obtained. In addition, the conventional white light emitting device has a defect that causes an increase in operating voltage because the cladding layer contains a rare earth element. In addition, the operating voltage is not increased.

  Note that although it has been described above that the semiconductor layer is provided above the light-emitting layer, this structure has a structure in which, when the semiconductor light-emitting element has a substrate, the top of the light-emitting layer provided on the substrate. In addition to the structure in which the semiconductor layer is provided, the structure in which the semiconductor layer is provided between the substrate and the light emitting layer is also included.

  In the semiconductor element of the present invention, it is preferable that the semiconductor layer further includes a plurality of layers, and the compositions of the layers in contact with each other among the layers in the plurality of layers are different. According to this preferred configuration, there is an advantage that carriers are easily confined spatially as compared with the case where the semiconductor layer is a single layer, so that the emission intensity can be further increased.

  In the semiconductor element of the present invention, it is preferable that the band gap energy in the light emitting layer is larger than the band gap energy of the semiconductor layer. According to this preferable configuration, the light from the light emitting layer is more easily absorbed by the semiconductor layer than the case where the semiconductor layer has a larger band gap energy than the light emitting layer. Therefore, the excitation efficiency of rare earth elements can be increased.

  In the semiconductor device of the present invention, it is preferable that the rare earth element is specifically at least one of Ce, Pr, Nd, Sm, Eu, Tb, Er, Tm and Yb. According to this preferred configuration, in the semiconductor light emitting device of the present invention, an element corresponding to a desired oscillation wavelength of light is selected from these rare earth elements and used. For example, Eu, Sm, Nd or Yb is used to obtain red light emission, Tb, Er, Nd or Yb is used to obtain green light emission, and Ce, Pr, Tm or Yb is used to obtain blue light emission. be able to. By doping a plurality of these rare earth elements and superimposing light emission, it is possible to easily realize light of a desired color, particularly white light.

In the semiconductor element of the present invention, the concentration of the rare earth element is preferably 1 × 10 ¹⁸ cm ⁻³ or more and 5 × 10 ²² cm ⁻³ or less. According to this preferred configuration, the emission intensity can be increased as compared with the case where no rare earth element is contained.

The semiconductor device of the present invention has a further said semiconductor layer is made of _{B x Ga 1-xyz Al y} In z N (0 ≦ x ≦ 1,0 ≦ y ≦ 1,0 ≦ z ≦ 1) layer It is preferable.

In the semiconductor element of the present invention, it is preferable that the semiconductor layer further includes a layer made of Al _x Ga _{1 -xy} In _y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1).

In the semiconductor element of the present invention, it is preferable that the semiconductor layer further includes a layer made of Al _x Ga _1-x As (0 ≦ x ≦ 1).

In the semiconductor device of the present invention, it is preferable that the semiconductor layer further includes a layer made of Zn _x Cd _{1 -x} S _y Se _{1 -y} (0 ≦ x ≦ 1, 0 ≦ y ≦ 1).

  The method for manufacturing a semiconductor light emitting device of the present invention preferably further includes a cap layer on the semiconductor layer containing the rare earth element.

  The method for producing a semiconductor light emitting device of the present invention is a method for producing a semiconductor light emitting device comprising a light emitting layer, a clad layer adjacent to the light emitting layer, and a semiconductor layer provided above the clad layer, A step of forming the semiconductor layer above the cladding layer and a step of selectively adding a rare earth element to at least a part of the semiconductor layer are provided.

  By this method, a semiconductor light emitting device can be produced on a large scale. In the semiconductor light emitting device manufactured by this method, when a rare earth element contained in the semiconductor layer is excited by light from the light emitting layer, fluorescence having a wavelength unique to the element is emitted. That is, by appropriately selecting a rare earth element, it is possible to realize light emission of a desired color with high light emission intensity without causing an increase in operating voltage.

  In the method for manufacturing a semiconductor light emitting device of the present invention, it is preferable that the rare earth element is added by an ion implantation method in the step of selectively adding the rare earth element to at least a part of the semiconductor layer. According to this preferable configuration, since a desired amount of rare earth element can be introduced at a desired position in a plurality of films, the yield can be improved.

In the method of manufacturing a semiconductor light emitting device according to the present invention, the rare earth element is further added at an implantation amount of 1 × 10 ¹³ cm ⁻² or more and 1 × 10 ¹⁷ cm ⁻² or less in order to add the rare earth element by the ion implantation method. It is preferable to inject. According to this preferred configuration, it is possible to obtain a semiconductor light emitting device having a higher emission intensity than that in the case where no rare earth element is implanted.

  In the method for producing a semiconductor light emitting device of the present invention, it is preferable to use any one of Ce, Pr, Nd, Sm, Eu, Tb, Er, Tm and Yb as the rare earth element.

  The method for producing a semiconductor light emitting device of the present invention is a method for producing a semiconductor light emitting device comprising a light emitting layer, a clad layer adjacent to the light emitting layer, and a semiconductor layer provided above the clad layer, A light emitting layer, a step of forming the clad layer, and a step of forming the semiconductor layer while supplying a rare earth element above the clad layer.

  By this method, a semiconductor light emitting device can be produced on a large scale. Even in a semiconductor light emitting device manufactured by this method, when a rare earth element contained in the semiconductor layer is excited by light from the light emitting layer, fluorescence having a wavelength unique to the element is emitted. That is, by appropriately selecting a rare earth element, it is possible to realize light emission of a desired color with high light emission intensity without causing an increase in operating voltage.

  The semiconductor light-emitting device of the present invention can emit various colors, particularly white light, with high emission intensity while maintaining the advantages of the conventional semiconductor light-emitting devices such as small size, light weight, low power consumption, and long life.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing the structure of a semiconductor light emitting device according to the first embodiment of the present invention.
As shown in FIG. 1, a semiconductor light emitting device 10 of this embodiment includes a (0001) plane sapphire substrate 11, a GaN base layer 12 made of GaN provided on the sapphire substrate 11, and a GaN A 300 nm thick n-type contact layer 13 made of n-type GaN provided on the underlayer and a 500 nm thick made of n-type Al _0.15 Ga _0.85 N provided on the n-type contact layer 13. An n-type cladding layer 14 is provided on the n-type cladding layer 14 and has a quantum well structure in which an In _0.15 Ga _0.85 N well layer having a thickness of 2 nm and a GaN barrier layer having a thickness of 6 nm are alternately stacked for three periods. A light-emitting layer 15, a p-type cladding layer 16 made of p-type Al _0.15 Ga _0.85 N having a thickness of 500 nm provided on the light-emitting layer 15, and a p-type GaN provided on the p-type cladding layer 16. A 300-nm-thick p-type contact layer 17 and a p-type contact Eu consisting of GaN layer having a thickness of 150nm which is provided on the layer 17 and a rare-earth-doped layer 18 doped. The upper layer portions of the rare earth doped layer 18, the p-type contact layer 17, the p-type cladding layer 16, the light emitting layer 15, the n-type cladding layer 14 and the n-type contact layer 13 are removed by etching to form an etched portion. An n-side electrode 19 is provided on the exposed portion of the n-type contact layer 13. A p-side electrode 20 is provided on the p-type contact layer 17. The concentration of Eu implanted into the rare earth doped layer 18 is in the range of 1 × 10 ¹⁸ cm ⁻³ or more and 5 × 10 ²² cm ⁻³ .

  Next, the manufacturing process of the semiconductor light emitting device of this embodiment will be described with reference to FIGS. 2A to 2E are cross-sectional views schematically showing the manufacturing process of the semiconductor light emitting device in the first embodiment of the present invention.

First, in the step shown in FIG. 2A, a base layer 12 made of GaN and having a thickness of 200 nm is deposited on the (0001) plane of the sapphire substrate 11 by metal organic chemical vapor deposition. On top of that, an n-type contact layer 13 is formed by growing GaN having a thickness of 300 nm while doping Si as an n-type impurity (donor). On top of this, Al having a thickness of 500 nm while doping Si is also formed. _The n-type cladding layer 14 is formed by growing _0.15 Ga _0.85 N. Thereafter, a well layer made of In _0.15 Ga _0.85 N having a thickness of 2 nm and a barrier layer made of GaN having a thickness of 6 nm are alternately grown three times on the n-type cladding layer 14 to obtain a total thickness of 24 nm. A light emitting layer 15 is formed, and a p-type cladding layer 16 is formed thereon by growing Al _0.15 Ga _0.85 N having a thickness of 500 nm while doping Mg as a p-type impurity (acceptor). The p-type contact layer 17 is formed by growing GaN having a thickness of 300 nm while doping the GaN. Thereafter, a rare earth doped layer 18 made of GaN having a thickness of 150 nm is formed on the p-type contact layer 17. Assuming that the rare earth element is uniformly doped with the rare earth element in the thin film, the emission intensity increases as the film thickness increases. However, when the film thickness exceeds a certain amount, the crystallinity decreases. Therefore, the thickness is preferably in the range of 100 nm to 500 nm.

In the present embodiment, the case where the light emitting layer 15 has a quantum well structure is described. However, in the present invention, a bulk may be used as the light emitting layer 15. Further, the conductivity types of the light emitting layer 15 and the rare earth doped layer 18 are not particularly specified, but may be any of p-type, n-type and undoped. The rare earth doped layer 18 is a GaN single layer film, but may be a multilayer film having a plurality of layers. For example, when using a multilayer film in which an In _0.20 Ga _0.80 N layer and a GaN layer are laminated for 20 periods each with a thickness of 3 nm, the emission intensity can be increased compared to the case of using a GaN single layer film. it can.

Next, in the step shown in FIG. 2B, Eu 21 is implanted into the rare earth doped layer 18 by ion implantation. Until the amount of Eu injected reaches a certain amount, the emission intensity increases as the amount increases, but when the amount of Eu injected exceeds the certain amount, the emission intensity decreases. The injection amount is in the range of 1 × 10 ¹³ to 1 × 10 ¹⁷ cm ⁻² .

  Next, in the step shown in FIG. 2C, an etching mask (not shown) having an opening is formed on the rare earth doped layer 18 and wet etching or dry etching is performed to remove the rare earth doped layer 18. To do. Thereafter, the etching mask is removed.

  Next, in the step shown in FIG. 2D, an etching mask (not shown) having an opening is formed on the rare earth doped layer 18 and wet etching or dry etching is performed, whereby the p-type contact layer 17, The p-type cladding layer 16, the light-emitting layer 15, the n-type cladding layer 14, and the upper layer portion of the n-type contact layer 13 are removed. Thereafter, the etching mask is removed.

  2E, an n-side electrode 19 made of Ti / Al or the like is formed on the n-type contact layer 13, and Ni / Au or Ni / Pt is formed on the p-type contact layer 17. By forming the p-side electrode 20 made of / Au or the like, the nitride semiconductor light emitting device 10 having a double hetero structure is completed.

  When a voltage of 3.5 V is applied between the p-side electrode 20 and the n-side electrode 19 of the nitride semiconductor light emitting device 10 of this embodiment and a current of 20 mA is passed, high-efficiency red light emission is confirmed. I was able to.

  In the present embodiment, blue light is generated from the light emitting layer 15, and Eu contained in the rare earth doped layer 18 is excited by a part of the blue light to emit red light. In the conventional white light emitting device, the cladding layer adjacent to the light emitting layer is doped with rare earth elements, which causes an increase in operating voltage. However, by providing a rare earth doped layer in a place where current does not need to flow. Does not cause an increase in operating voltage.

  In addition, in the conventional white light emitting element, the malfunction that the red light component was weak has arisen, but the light containing red light can be obtained by using the means of this embodiment. In addition, although the light color of the conventional white light emitting element was easily changed, white light with a stable color can be obtained by using a rare earth element that generates green or blue light in addition to Eu used in the present embodiment. be able to. For example, Tb or Er can be used to obtain green light emission, and Ce, Pr, or Tm can be used to obtain blue light emission.

(Second Embodiment)
FIG. 3 is a cross-sectional view showing the structure of the semiconductor light emitting device in the second embodiment of the present invention. As shown in FIG. 3, the semiconductor light emitting device 30 of the present embodiment includes a (0001) plane sapphire substrate 31, an AlN base layer 32 made of AlN provided on the sapphire substrate 31, and a lower layer. From a stack 33 made of Al _0.25 Ga _0.75 N layer having a thickness of 500 nm provided on the base layer 32 and doped with Tm, Er, Eu, and n-type Al _0.25 Ga _0.75 N provided on the stack 33 An n-type cladding layer 34 and an Al _0.30 Ga _0.70 N well layer having a thickness of 2 nm and an Al _0.40 Ga _0.60 N barrier layer having a thickness of 6 nm are alternately stacked in three periods. A light emitting layer 35 having a quantum well structure, a p-type cladding layer 36 having a thickness of 300 nm made of a p-type Al _0.25 Ga _0.75 N layer, and a p-type cladding layer 36. A p-type contact layer 37 made of p-type GaN and having a thickness of 100 nm. To have. The total concentration of Tm, Er and Eu doped in the stack 33 is in the range of 1 × 10 ^{18 to} 5 × 10 ²² cm ⁻³ . The upper layer portions of the p-type contact layer 37, the p-type cladding layer 36, the light emitting layer 35 and the n-type cladding layer 34 are removed by etching to form an etched portion. A p-side electrode 39 is provided on the p-type contact layer 37, and an n-side electrode 38 is provided on the n-type cladding layer 34.

  In the semiconductor light emitting device 30 of this embodiment, the stacked layer 33 may be grown while doping Tm, Er, and Eu, or Tm, Er, and Eu may be ion-implanted after the crystal is grown.

In the present embodiment, the band gap energy (Ega) of the light emitting layer 35 is larger than the band gap energy (Egm) of the stack 33 containing Tm, Er, and Eu. In this case, compared to the case where the stacked layer 33 has a larger band gap energy than the light emitting layer 35, the proportion of the light emitted from the light emitting layer 35 (light emitting energy) that is absorbed by the stacked layer 33 is higher. Therefore, the excitation efficiency of rare earth elements can be increased. Here, the light emitted from the light emitting layer 35 is ultraviolet light, and when this ultraviolet light is absorbed by the laminate 33, Tm emits blue light, Er emits green light, and Eu emits red light. . As a result of mixing these three colors, white light emission becomes possible. In fact, about three times as much white light emission was confirmed as compared with the case where the laminated layer 33 was an Al _0.44 Ga _0.56 N layer (corresponding to the relationship of Egm> Ega).

(Third embodiment)
FIG. 5 is a cross-sectional view showing the structure of a semiconductor light emitting device in the third embodiment of the present invention.

  As shown in FIG. 5, the semiconductor light emitting device 50 of the present embodiment is obtained by providing a cap layer 51 on the rare earth doped layer 18 of the semiconductor light emitting device shown in FIG. 1. Here, the cap layer 51 is made of undoped GaN and has a thickness of 64 nm.

  Here, the reason why the cap layer 51 is provided is that the rare earth element concentration in the rare earth doped layer 18 is maximized when the rare earth element is doped by the ion implantation method.

  Regarding the manufacturing process of the semiconductor light emitting device of this embodiment, the cap layer 51 is subsequently formed after the rare earth doped layer 18 is formed in the process of FIG. Other steps are the same as those in the first embodiment.

  The film thickness of the cap layer 51 is desirably in the range of 20 nm to 80 nm in order to maximize the rare earth element concentration in the rare earth doped layer 18 portion.

  In relation to the semiconductor light emitting device shown in the above embodiment, examination is made as to how the emission intensity of the rare earth doped layer 18 differs between the case where an AlGaN / InGaN quantum well is used as the rare earth doped layer 18 and the case where GaN is used. did.

  The result of comparing the intensity of light emitted from the AlGaN / InGaN quantum well structure rare earth doped layer (hereinafter referred to as sample A) and bulk GaN rare earth doped layer (hereinafter referred to as sample B) is shown below. Show. Here, the structural parameters relating to the samples A and B are shown in Table 1. Here, Eu was used as the rare earth.

  FIG. 6 shows the relationship between the amount of doped Eu and the emission intensity for samples A and B, and FIG. 7 shows the relationship between the annealing temperature and the emission intensity.

  As can be seen from both FIG. 6 and FIG. 7, the emission intensity of sample A was improved than that of sample B. This is because the thickness of each layer of the rare earth doped layer of Sample A is 10 nm or less, so that the stress acting on each layer is small and the crystallinity is not lowered, and the quantum effect occurs and carriers are easily confined spatially. This is probably because of this.

Further, FIG. 6 shows that the doping amount of Eu for improving the emission intensity is 1 × 10 ¹⁴ cm ⁻² or more, and FIG. 7 shows that the annealing temperature for improving the emission intensity is 900 ° C. or more. .

Note that the upper limit of the Eu doping amount is 1 × 10 ¹⁷ cm ⁻² . This is because the emission intensity increases as the amount of Eu doped increases until a certain amount is reached, but the emission intensity decreases when the amount of Eu doped exceeds the certain amount. It is. The upper limit of the annealing temperature is 1500 ° C. This is because the semiconductor material constituting the rare earth doped layer is decomposed.

  From the above, it was found that light containing high-intensity red light can be obtained by using the means of this embodiment.

  If a rare earth element that generates green or blue light is used in addition to Eu used in the present embodiment, white light with stable hue can be obtained. For example, Tb or Er can be used to obtain green light emission, and Ce, Pr, or Tm can be used to obtain blue light emission.

(Modification)
A cross-sectional view of a modification of the third embodiment is shown in FIG.

  As shown in FIG. 8, in the semiconductor light emitting device 80 of the present embodiment, a cap layer 81 is provided on the rare earth doped layer 18 and an intermediate layer 82 is provided below the rare earth doped layer 18 of the semiconductor light emitting device shown in FIG. It is a thing. Here, both the cap layer 81 and the intermediate layer 82 are made of undoped GaN. The cap layer 81 has a thickness of 64 nm, and the intermediate layer 82 has a thickness of 68 nm.

  In the manufacturing process of the semiconductor light emitting device of this modification, the intermediate layer 82 is formed before the rare earth doped layer 18 is formed in the process of FIG. 2A, and then the rare earth doped layer 18 and the cap layer 81 are formed. . Further, in the step of FIG. 2C, the etching including the intermediate layer 82 is selectively performed. Other steps are the same as those in the first embodiment.

  The film thickness of the cap layer 81 is preferably in the range of 20 nm or more and 80 nm or less so that the rare earth element concentration in the rare earth doped layer 18 is maximized.

  In this modified example as well, light containing high-intensity red light can be obtained as described above.

  Although the first to third embodiments have been specifically described above, the present invention is not limited to these embodiments, and various modifications based on the technical idea of the present invention are possible. For example, the numerical values, element structures, substrates, processes, growth methods and the like given in the above-described embodiments are merely examples, and different numerical values, element structures, processes, growth methods, and the like may be used as necessary. . Specifically, in the above-described embodiment, metal organic vapor phase epitaxy is used, but other epitaxial growth methods such as molecular beam epitaxy may be used. Further, in the above-described embodiment, only the case where the invention is applied to a white light emitting element or a red light emitting element has been described, but the present invention can also be applied to a multicolor light emitting element that mixes two or more colors.

  The semiconductor light emitting device and the method for manufacturing the same according to the present invention are capable of realizing various colors, particularly white light emission with strong light emission intensity while maintaining the conventional advantages such as small size, light weight, low power consumption, and long life. Industrial applicability is high.

Sectional drawing which shows the structure of the semiconductor light-emitting device in the 1st Embodiment of this invention. (A)-(e) is sectional drawing which shows typically the manufacturing process of the semiconductor light-emitting device in the 1st Embodiment of this invention. Sectional drawing which shows the structure of the semiconductor light-emitting device in the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the conventional white light illuminating device typically Sectional drawing which shows the structure of the semiconductor light-emitting device in the 3rd Embodiment of this invention. The graph which shows the relationship between the doping amount of Eu of the quantum well structure (sample A) and bulk GaN (sample B) of AlGaN / InGaN and light emission intensity in the 3rd Embodiment of this invention. The graph which shows the relationship between the annealing temperature and light emission intensity of the AlGaN / InGaN quantum well structure (sample A) and bulk GaN (sample B) in the 3rd Embodiment of this invention Sectional drawing which shows the structure of the semiconductor light-emitting device in the modification of the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor light-emitting device 11 Sapphire substrate 12 Underlayer 13 n-type contact layer 14 n-type clad layer 15 Light-emitting layer 16 p-type clad layer 17 p-type contact layer 18 Rare earth doped layer 19 n-side electrode 20 p-side electrode 21 Eu
DESCRIPTION OF SYMBOLS 30 Semiconductor light-emitting device 31 Sapphire substrate 32 Underlayer 33 Stacking 34 N-type clad layer 35 Light-emitting layer 36 P-type clad layer 37 P-type contact layer 38 N-side electrode 39 P-side electrode 40 Semiconductor light-emitting device 41 Sapphire substrate 42 N-type contact layer 43 n-type cladding layer 44 light-emitting layer 45 p-type cladding layer 46 p-type contact layer 47 n-side electrode 48 p-side electrode 51 cap layer 81 cap layer 82 intermediate layer

Claims (15)

A semiconductor light emitting device comprising: a light emitting layer; a cladding layer adjacent to the light emitting layer; and a semiconductor layer provided above the cladding layer and including a rare earth element at least partially. The semiconductor light emitting element according to claim 1, wherein the semiconductor layer has a plurality of layers, and the compositions of the layers in contact with each other among the layers in the plurality of layers are different. The semiconductor light emitting element according to claim 1, wherein a band gap energy in the light emitting layer is larger than a band gap energy of the semiconductor layer. 4. The semiconductor light emitting element according to claim 1, wherein the rare earth element is at least one of Ce, Pr, Nd, Sm, Eu, Tb, Er, Tm, and Yb. 5. The semiconductor light emitting element according to claim 1, wherein the concentration of the rare earth element is 1 × 10 ¹⁸ cm ⁻³ or more and 5 × 10 ²² cm ⁻³ or less. The semiconductor _{layer, B x Ga 1-xyz Al} y In z N (0 ≦ x ≦ 1,0 ≦ y ≦ 1,0 ≦ z ≦ 1) any one of the preceding claims having a layer of a The semiconductor light emitting device according to item. The semiconductor _{layer, Al x Ga 1-xy In} y P (0 ≦ x ≦ 1,0 ≦ y ≦ 1) semiconductor light-emitting device according to any one of claims 1 to 3 having a layer. The semiconductor layer, Al _x Ga _1-x As semiconductor light-emitting device according to any one of claims 1 to 3 with a (0 ≦ x ≦ 1) consists of a layer. The semiconductor layer is a semiconductor light emitting device having a layer made of Zn _x Cd _{1 -x} S _y Se _{1 -y} (0 ≦ x ≦ 1, 0 ≦ y ≦ 1). The semiconductor light emitting element according to claim 1, further comprising a cap layer on the semiconductor layer containing the rare earth element. A method for manufacturing a semiconductor light emitting device, comprising: a light emitting layer; a cladding layer adjacent to the light emitting layer; and a semiconductor layer provided above the cladding layer, wherein the semiconductor layer is formed above the cladding layer. And a method of selectively adding a rare earth element to at least a part of the semiconductor layer. The method for manufacturing a semiconductor light emitting element according to claim 11, wherein in the step of selectively adding a rare earth element to at least a part of the semiconductor layer, the rare earth element is added by an ion implantation method. 13. The semiconductor light emitting device according to claim 12, wherein the rare earth element is added at an implantation amount of 1 × 10 ¹³ cm ⁻² or more and 1 × 10 ¹⁷ cm ⁻² or less when the rare earth element is added by the ion implantation method. Production method. The method for manufacturing a semiconductor light emitting element according to claim 11, wherein any one of Ce, Pr, Nd, Sm, Eu, Tb, Er, Tm, and Yb is used as the rare earth element. A method for manufacturing a semiconductor light emitting device, comprising: a light emitting layer; a clad layer adjacent to the light emitting layer; and a semiconductor layer provided above the clad layer, wherein the light emitting layer and the clad layer are formed. And a step of forming the semiconductor layer while supplying a rare earth element above the cladding layer.

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