JP6478685B2 - Semiconductor light emitting device - Google Patents

Description

  The present invention provides an nitridation having an active layer in which a light emitting layer made of a nitride semiconductor and a barrier layer made of a nitride semiconductor are alternately stacked between an n-type nitride semiconductor layer and a p-type nitride semiconductor layer. The present invention relates to a semiconductor light emitting device.

  Today, nitride semiconductors are being used and developed for applications of light emitting elements such as LEDs (light emitting diodes) and LDs (laser diodes) (see, for example, Patent Documents 1 and 2).

Japanese Patent No. 3498697 JP 11-298090 A

  The present inventor manufactured a plurality of semiconductor light emitting elements using the same material and injected a current into each element. As a result, an element that actually emits light and an element that emits little light or hardly emits light are mixed. Eyes on. Then, these devices were evaluated for crystals, but there was no significant difference in crystallinity between them.

  As a result of further earnest research on the phenomenon that the device emits light or does not emit light, the present inventor found that between the light emitting device and the device that did not emit light, It was found that there was a difference in the C concentration at a specific location.

  In view of the above consideration, an object of the present invention is to realize a nitride semiconductor light emitting device exhibiting high light emission intensity.

The present invention provides an nitridation having an active layer in which a light emitting layer made of a nitride semiconductor and a barrier layer made of a nitride semiconductor are alternately stacked between an n-type nitride semiconductor layer and a p-type nitride semiconductor layer. A semiconductor light emitting device,
A C concentration of a final barrier layer formed at a position closest to the p-type nitride semiconductor layer among the barrier layers is 1 × 10 ¹⁸ / cm ³ or less.

As a result of diligent research by the present inventors, it was confirmed that a light-emitting element with high emission intensity can be realized by configuring a nitride semiconductor light-emitting element with the C concentration of the final barrier layer being 1 × 10 ¹⁸ / cm ³ or less. . In particular, by setting the C concentration of the final barrier layer to 5 × 10 ¹⁷ / cm ³ or less, a light emitting element with higher emission intensity is realized. This result will be described later with reference to the examples in the section “DETAILED DESCRIPTION”.

As a result of intensive studies by the present inventors, it has been confirmed that when the C concentration of the final barrier layer is higher than 1 × 10 ¹⁸ / cm ^{3, the} emission intensity decreases as the C concentration increases. The reason for this is not clear at the present time, but the present inventor presumes this reason as follows. That is, the high C concentration in the final barrier layer prevents the movement of holes from the p-type nitride semiconductor layer toward the light emitting layer. Since holes have a lower mobility than electrons, among the plurality of light-emitting layers constituting the active layer, electrons and holes easily recombine in the light-emitting layer formed near the p-type nitride semiconductor layer. The light emitting layer contributes most to light emission. However, since the C concentration in the final barrier layer is high, holes cannot be sufficiently transferred into the light emitting layer that contributes most to light emission. As a result, the recombination probability of electrons and holes in the light emitting layer is lowered, and the emission intensity is lowered accordingly.

From this point of view, in the light emitting device having another layer between the p-type nitride semiconductor layer and the final barrier layer, the C concentration of the other layer is also set to 1 × 10 ¹⁸ / cm ³ or less. Thus, holes can be injected with high efficiency into the light emitting layer that contributes most to light emission. Note that in this case, it is more preferable that the light-emitting element is formed with the C concentration of the other layer being 5 × 10 ¹⁷ / cm ³ or less.

  Each semiconductor layer constituting the nitride semiconductor light emitting element is generally formed by MOCVD (Metal Organic Chemical Vapor Deposition). The C component present in the final barrier layer is considered to be derived from the C element contained in the organometallic compound such as trimethylgallium (TMG) used as the source gas. Therefore, the C concentration of the final barrier layer can be appropriately adjusted by appropriately changing the flow rates of the source gas and the carrier gas and the profile of the growth temperature.

  According to the present invention, a nitride semiconductor light emitting device exhibiting high light emission intensity is realized.

It is sectional drawing which shows typically the structure of a nitride semiconductor light-emitting device. It is sectional drawing which shows typically a part of structure of the nitride semiconductor light-emitting device. It is a graph which shows the relationship between the emitted light quantity of each element of Examples 1-3 and the comparative example 1, and supply current. It is sectional drawing which shows typically another structure of the nitride semiconductor light-emitting device. It is sectional drawing which shows typically a part of another structure of the nitride semiconductor light-emitting device.

  The nitride semiconductor light emitting device of the present invention will be described with reference to the drawings. In the following drawings, the actual dimensional ratio does not necessarily match the dimensional ratio on the drawing.

[Construction]
FIG. 1 is a cross-sectional view schematically showing the structure of a nitride semiconductor light emitting device. A nitride semiconductor light emitting device 1 shown in FIG. 1 (hereinafter abbreviated as “light emitting device 1” as appropriate) is provided on a substrate 2 with an undoped layer 3, an n-type nitride semiconductor layer 4, an active layer 5, and p. A type nitride semiconductor layer 6 is provided.

(Substrate 2)
The substrate 2 is composed of a sapphire substrate. In addition to sapphire, Si, SiC, AlN, AlGaN, GaN, YAG, or the like may be used.

(Undoped layer 3)
The undoped layer 3 is formed of GaN. More specifically, it is formed of a low-temperature buffer layer made of GaN and an underlying layer made of GaN on the upper layer.

(N-type nitride semiconductor layer 4)
The n-type nitride semiconductor layer 4 is composed of Al _X1 In _Y1 Ga _Z1 N (0 ≦ X1 ≦ 1, 0 ≦ Y1 ≦ 1, 0 ≦ Z1 ≦ 1, X1 + Y1 + Z1 = 1). As an example, the n-type nitride semiconductor layer 4 is composed of n-Al _0.06 Ga _0.94 N. Si is preferably used as the n-type impurity as the dopant, but Ge, S, Se, Sn, Te, or the like can also be used.

  The n-type nitride semiconductor layer 4 may include a layer (protective layer) made of n-GaN in a region in contact with the undoped layer 3.

(Active layer 5)
The active layer 5 includes a light emitting layer made of Al _X3 In _Y3 Ga _Z3 N (0 ≦ X3 ≦ 1, 0 ≦ Y3 ≦ 1, 0 ≦ Z3 ≦ 1, X3 + Y3 + Z3 = 1), Al _X4 In _Y4 Ga _Z4 N (0 ≦ X4 ≦ 1, 0 ≦ Y4 ≦ 1, 0 ≦ Z4 ≦ 1, X4 + Y4 + Z4 = 1) and a plurality of barrier layers are repeated. The light emitting layer constituting the active layer 5 only needs to have a lower band gap energy than the barrier layer constituting the active layer 5. The active layer 5 is configured by repeating a plurality of layers, for example, a light emitting layer made of InGaN and a barrier layer made of AlGaN. These layers may be undoped or p-type or n-type doped. In addition, the notation “InGaN” here merely describes that it is a nitride semiconductor layer containing In and Ga, and does not mean that the composition ratio of In and Ga is 1: 1. Absent. The same applies to the notation “AlGaN”.

  The configuration of the active layer 5 will be described in detail with reference to FIG. FIG. 2 is an enlarged cross-sectional view schematically showing the active layer 5 and the vicinity thereof in the nitride semiconductor light emitting device 1.

  The active layer 5 includes a barrier layer (5a, 5c, 5e, 5g, 5i, 5k) formed of a nitride semiconductor, and a light emitting layer (5b, 5d, 5f, 5h, 5j) formed of a nitride semiconductor. Are stacked alternately. In the present embodiment, the active layer 5 includes six barrier layers and five light-emitting layers, but the number of barrier layers and light-emitting layers is merely an example and can be set as appropriate.

The active layer 5 will be described with reference to FIG. 2. Of the active layer 5, the barrier layers (5a, 5c, 5e, 5g, 5i, 5k) are made of AlGaN, and the light emitting layers (5b, 5d, 5f). , 5h, 5j) are made of InGaN. As an example, the active layer included in the nitride semiconductor light emitting device 1 in the present embodiment includes a barrier layer (5a, 5c, 5e, 5g, 5i, 5k) made of Al _0.08 Ga _0.92 N, In _{0. 03} Ga _0.97 emitting layer composed of N (5b, 5d, 5f, 5h, 5j) is constructed out with.

The light emitting element 1 includes the barrier layer 5k formed at the position closest to the p-type nitride semiconductor layer 6 among the barrier layers (5a, 5c, 5e, 5g, 5i, 5k), that is, the final barrier layer 5k. The C concentration is 1 × 10 ¹⁸ / cm ³ or less.

(P-type nitride semiconductor layer 6)
The p-type nitride semiconductor layer 6 is composed of Al _X2 In _Y2 Ga _Z2 N (0 ≦ X2 ≦ 1, 0 ≦ Y2 ≦ 1, 0 ≦ Z2 ≦ 1, X2 + Y2 + Z2 = 1). As an example, the p-type nitride semiconductor layer 6 can have a stacked structure of p-Al _0.3 Ga _0.7 N and p-Al _0.09 Ga _0.91 N. Mg is preferably used as the p-type impurity as the dopant, but Be, Zn, and the like can also be used.

Further, the p-type nitride semiconductor layer 6 may have a high-concentration p-GaN layer for contact above the Al _X2 In _Y2 Ga _Z2 N layer.

[Manufacturing process]
Next, a manufacturing process of the light emitting device 1 shown in FIGS. 1 and 2 will be described. This manufacturing process is merely an example, and the gas flow rate, the furnace temperature, the furnace pressure, and the like may be appropriately adjusted.

(Step S1)
First, the undoped layer 3 is formed on the upper layer of the substrate 2. This is realized, for example, by the following method.

  A sapphire substrate is prepared as the substrate 2 and the c-plane sapphire substrate is cleaned. More specifically, for this cleaning, for example, a c-plane sapphire substrate is placed in a processing furnace of a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus, and hydrogen gas at a predetermined flow rate is supplied into the processing furnace. This is performed by raising the temperature in the furnace to a predetermined temperature while flowing.

  Next, a low-temperature buffer layer made of GaN is formed on the surface of the c-plane sapphire substrate, and an underlayer made of GaN is further formed thereon. These low-temperature buffer layer and underlayer correspond to the undoped layer 3. Specifically, in a state where the temperature and pressure in the furnace in the МОCVD apparatus are set to predetermined values, while a nitrogen gas and a hydrogen gas are allowed to flow in the furnace at a predetermined flow rate as a carrier gas, It is executed by supplying trimethylgallium (TMG) and ammonia at a flow rate for a predetermined time. Thereby, a low-temperature buffer layer made of GaN having a predetermined thickness (for example, 20 nm) is formed on the surface of the c-plane sapphire substrate.

  Next, in a state where the furnace temperature of the MOCVD apparatus is raised, the flow rate and supply time of the carrier gas and the source gas are appropriately adjusted, so that a predetermined thickness (eg, 1.7 μm) is formed on the surface of the low temperature buffer layer. ) Of GaN is formed.

(Step S2)
Next, an n-type nitride semiconductor layer 4 having a composition of Al _X1 In _Y1 Ga _Z1 N is formed on the undoped layer 3. Specifically, in a state where the temperature and pressure in the furnace in the МОCVD apparatus are set to predetermined values, while a nitrogen gas and a hydrogen gas are allowed to flow in the furnace at a predetermined flow rate as a carrier gas, This is performed by supplying TMG, trimethylaluminum (TMA), ammonia, and tetraethylsilane for doping n-type impurities at a flow rate for a predetermined time. Thereby, for example, an n-type nitride semiconductor layer 4 having a composition of Al _0.06 Ga _0.94 N and a thickness of 1.7 μm is formed in the upper layer of the undoped layer 3.

In this step, when the n-type nitride semiconductor layer 4 is realized by Al _X1 In _Y1 Ga _Z1 N, trimethylindium (TMI) at a predetermined flow rate may be added as a source gas.

(Step S3)
Next, the active layer 5 is formed on the n-type nitride semiconductor layer 4. At this time, the step of forming the light emitting layer (5b, 5d, 5f, 5h, 5j) and the step of forming the barrier layer (5a, 5c, 5e, 5g, 5i, 5k) are performed alternately.

  Specifically, in a state where the temperature and pressure in the furnace in the МОCVD apparatus are set to predetermined values, while a nitrogen gas and a hydrogen gas are allowed to flow in the furnace at a predetermined flow rate as a carrier gas, Barrier layers (5a, 5c, 5e, 5g, 5i, 5k) are formed by supplying TMG, TMA, ammonia, and tetraethylsilane at a flow rate for a predetermined time. Also, with the temperature and pressure in the furnace in the МОCVD apparatus set to predetermined values, TMG at a predetermined flow rate as a source gas while flowing nitrogen gas and hydrogen gas as a carrier gas at a predetermined flow rate in the furnace. , TMI, and ammonia are supplied for a predetermined time to form the light emitting layers (5b, 5d, 5f, 5h, 5j). The thickness of each layer can be adjusted by the supply time of the source gas, and the number of periods of the light emitting layer and the barrier layer can be adjusted by the number of repetitions.

  Thereby, for example, the active layer 5 having the barrier layer (5a, 5c, 5e, 5g, 5i, 5k) made of n-type AlGaN having a thickness of 20 nm and the light emitting layer (5b, 5d, 5f, 5f, made of InGaN having a thickness of 2 nm). 5h, 5j) are formed on the upper surface of the n-type nitride semiconductor layer 4.

  Here, a process in the case where the light emitting layers (5b, 5d, 5f, 5h, 5j) are undoped and the barrier layers (5a, 5c, 5e, 5g, 5i, 5k) are doped with n-type impurities is shown. However, these layers may be undoped or may be doped p-type or n-type.

  Further, the light emitting layers (5b, 5d, 5f, 5h, 5j) may be made of AlInGaN. In this case, it can be realized by including TMA at a predetermined flow rate in the source gas. Similarly, the barrier layers (5a, 5c, 5e, 5g, 5i, 5k) may be made of AlInGaN. In this case, it can be realized by including a predetermined flow rate of TMI in the source gas.

(Step S4)
Next, a p-type nitride semiconductor layer 6 made of Al _X2 In _Y2 Ga _Z2 N is formed on the active layer 5. Specifically, in a state where the temperature and pressure in the furnace in the МОCVD apparatus are set to predetermined values, while a nitrogen gas and a hydrogen gas are allowed to flow in the furnace at a predetermined flow rate as a carrier gas, This is carried out by supplying biscyclopentadinier magnesium (Cp ₂ Mg) for doping TMG, TMA, ammonia and p-type impurities at a flow rate for a predetermined time. As a result, for example, the p-type nitride semiconductor layer 6 having a stacked structure of Al _0.3 Ga _0.7 N having a thickness of 20 nm and Al _0.09 Ga _0.91 N having a thickness of 150 nm is activated. Formed on top of layer 5. In this step, when the p-type nitride semiconductor layer 6 is realized by Al _X2 In _Y2 Ga _Z2 N, a TMI having a predetermined flow rate may be further added as a source gas.

After that, the high-concentration p-type GaN layer may be formed by stopping the supply of TMA and changing the flow rate of Cp ₂ Mg as appropriate to supply the source gas for a predetermined time. In this case, the p-type nitride semiconductor layer 6 has a stacked structure of Al _X2 In _Y2 Ga _Z2 N and a high-concentration p-type GaN layer.

(Later process)
When realizing the so-called “lateral structure” light-emitting element 1 in which the n-side electrode and the p-type electrode are arranged on the same surface side of the substrate 2, a part of the upper surface of the n-type nitride semiconductor layer 4 is exposed by ICP etching. Then, an n-side electrode is formed on the exposed n-type nitride semiconductor layer 4 and a p-side electrode is formed on the p-type nitride semiconductor layer 6. And each element is isolate | separated with a laser dicing apparatus, for example, and wire bonding is performed with respect to an electrode.

  On the other hand, when manufacturing the so-called “vertical structure” light-emitting element 1 in which the n-side electrode is disposed on one surface of the substrate and the p-side electrode is disposed on the other surface, the following procedure is followed. First, a metal electrode (reflective electrode), a solder diffusion prevention layer, and a solder layer, which are p-side electrodes, are formed on the p-type nitride semiconductor layer 6. And after bonding together the support substrate (for example, CuW board | substrate) comprised with the conductor or the semiconductor via the solder layer, the board | substrate 2 is peeled by methods, such as laser irradiation, upside down. Thereafter, an n-side electrode is formed on the n-type nitride semiconductor layer 4. Thereafter, element isolation and wire bonding are performed as in the horizontal structure.

[Evaluation]
Regarding the light-emitting element 1 shown in FIGS. 1 and 2, the characteristics of the element were evaluated by changing the C concentration of the final barrier layer 5k. Specifically, the C concentration of the final barrier layer 5k was changed by changing the growth conditions in step S3 and the growth conditions of the p-type nitride semiconductor layer 6 in step S4. The composition and thickness of each layer in each example and comparative example are common.

  More specifically, in the above-described process, only the C concentration of the final barrier layer 5k was changed by varying the temperature increase rate of the furnace temperature and the supply start timing of the source gas.

  Note that the light-emitting element 1 according to the present embodiment employs a configuration in which the final barrier layer 5k is in contact with the p-type nitride semiconductor layer 6. For this reason, not only the raw material gas for growing the final barrier layer 5k but also the raw material gas for growing the p-type nitride semiconductor layer 6 may affect the C concentration contained in the final barrier layer 5k. . For this reason, as described above, the C concentration of the final barrier layer 5k is changed by changing the growth conditions in both step S3 and step S4.

In the light-emitting element of Example 1, the C concentration of the final barrier layer 5k is 5 × 10 ¹⁶ / cm ³ . This value substantially corresponds to the detection limit.
In the light-emitting element of Example 2, the C concentration of the final barrier layer 5k is 5 × 10 ¹⁷ / cm ³ .
In the light-emitting element of Example 3, the C concentration of the final barrier layer 5k is 1 × 10 ¹⁸ / cm ³ .
In the light emitting device of Comparative Example 1, the C concentration of the final barrier layer 5k is 2 × 10 ¹⁸ / cm ³ .

  In each of the above Examples 1-3 and Comparative Example 1, the value of C concentration in the final barrier layer 5k is derived using SIMS (Secondary Ion Mass Spectrometry). .

FIG. 3 is a graph showing the relationship between the emission intensity and the supply current of each element of Examples 1-3 and Comparative Example 1. According to FIG. 3, the device of Example 1 in which the C concentration of the final barrier layer 5k is 5 × 10 ¹⁶ / cm ³ and Example 2 in which the C concentration of the final barrier layer 5k is 5 × 10 ¹⁷ / cm ^3. This element shows a high light emission intensity of approximately the same level.

On the other hand, the device of Comparative Example 1 in which the C concentration of the final barrier layer 5k showed the highest value of 2 × 10 ¹⁸ / cm ³ showed almost no light emission. In addition, although the device of Example 3 in which the C concentration of the final barrier layer 5k is 1 × 10 ¹⁸ / cm ³ between Example 2 and Comparative Example 1 has lower emission intensity than the device of Example 2, Compared with the device of Comparative Example 1, light emission with sufficient intensity was confirmed.

  In view of the result of FIG. 3, it can be seen that the emission intensity of the device tends to decrease as the C concentration of the final barrier layer 5k increases. The reason for this is not clear, but as a result of the high C concentration in the final barrier layer 5k, injection of holes from the p-type nitride semiconductor layer 6 to the light emitting layer (5j, etc.) is hindered, and the light emitting layer (5j, etc.) It is presumed that the emission intensity was lowered due to the decrease in the recombination probability of electrons and holes in.

  Since holes have a lower mobility than electrons, light emission located near the p-type nitride semiconductor layer 6 among the light emitting layers (5b, 5d, 5f, 5h, 5j) constituting the active layer 5 In the layer (for example, the light emitting layer 5j), electrons and holes are recombined most efficiently. That is, the light emitting layer located near the p-type nitride semiconductor layer 6 is the layer most contributing to light emission. However, when the C concentration of the final barrier layer 5k located between the light emitting layer 5j and the p-type nitride semiconductor layer 6 is high as in Comparative Example 1, the amount of holes injected into the light emitting layer 5j that contributes most to light emission. It is considered that the emission intensity was reduced as compared with Example 1 and Example 2 due to the decrease in

In view of this inference, it can be seen that a light emitting element exhibiting high light emission intensity can be realized by forming the light emitting element 1 so that the C concentration of the final barrier layer 5k is as low as possible. In particular, in FIG. 3, when the case where a current of 0.1 A is applied to the device is compared, the device of Example 3 in which the C concentration of the final barrier layer 5k is 1 × 10 ¹⁸ / cm ³ is the final barrier layer. The emission intensity is reduced to about 60% as compared with the element of Example 1 in which the C concentration of 5k is 5 × 10 ¹⁶ / cm ³ . The device of Comparative Example 1 in which the C concentration of the final barrier layer 5k is 2 × 10 ¹⁸ / cm ³ is 5% or less of the light emission intensity of the device of Example 1, and hardly emits light. That is, by setting the C concentration of at least the final barrier layer 5k to 1 × 10 ¹⁸ / cm ³ or less, a light emitting device exhibiting a light emission intensity that can withstand practical use is realized, and the C concentration of the final barrier layer 5k is further set to 5 × 10 5. ^By setting it to ¹⁷ / cm ³ or less, a light-emitting element exhibiting extremely high light emission intensity is realized.

The same experiment was performed with the number of stacked light emitting layers and barrier layers constituting the active layer 5 being different from the above example, but the same tendency as in FIG. 3 was obtained. Further, the same experiment was conducted by changing the composition of the barrier layer, the composition of the p-type nitride semiconductor layer 6, or the thickness of the barrier layer from the above example, but the same tendency as in FIG. 3 was obtained. It was. Also from this fact, by setting the C concentration of at least the final barrier layer 5k to 1 × 10 ¹⁸ / cm ³ or less, a light emitting device exhibiting a light emission intensity that can withstand practical use is realized, and further, the C concentration of the final barrier layer 5k is reduced. It is concluded that a light emitting element exhibiting an extremely high light emission intensity is realized by setting it to 5 × 10 ¹⁷ / cm ³ or less.

In the above embodiment, the case where the active layer 5 is formed by repeating the light emitting layer and the barrier layer a plurality of periods has been described. However, the active layer 5 may have a single light emitting layer. Absent. In this case, the active layer 5 has a light emitting layer and two barrier layers sandwiching the light emitting layer, and is realized by alternately stacking the barrier layers and the light emitting layers. Of the two barrier layers, the barrier layer closest to the p-type nitride semiconductor layer 6 corresponds to the final barrier layer, and the C concentration of the final barrier layer is 1 × 10 ¹⁸ / cm ³ or less.

In view of the fact that C contained in the final barrier layer 5k prevents the movement of holes from the p-type nitride semiconductor layer 6, the light-emitting element 1 includes the final barrier layer 5k, the p-type nitride semiconductor layer 6, and the like. In the case of having another layer between them, the C concentration is preferably 1 × 10 ¹⁸ / cm ³ or less for the other layer. 4 is a cross-sectional view schematically showing another structure of the light-emitting element 1, and FIG. 5 is an enlarged schematic view of the active layer 5 and the vicinity thereof in the light-emitting element 1 shown in FIG. FIG. The light-emitting element 1 shown in FIGS. 4 and 5 is configured to include an undoped AlGaN layer 7 between the final barrier layer 5k and the p-type nitride semiconductor layer 6. In such a case, the C concentration contained in the final barrier layer 5k and the undoped AlGaN layer 7 is configured to be 1 × 10 ¹⁸ / cm ³ or less. As a result, the injection of holes into the light emitting layer (such as the light emitting layer 5j) close to the p-type nitride semiconductor layer 6 is increased, and the light emission intensity is improved.

  In the example described with reference to FIGS. 4 and 5, the layer formed between the final barrier layer 5k and the p-type nitride semiconductor layer 6 is the undoped AlGaN layer 7, but this is only an example, Another layer may be formed.

In the configuration shown in FIGS. 4 and 5, a plurality of layers may be interposed between the final barrier layer 5 k and the p-type nitride semiconductor layer 6. In this case, it is preferable that the C concentration contained in the plurality of layers is 1 × 10 ¹⁸ / cm ³ or less.

1: Nitride semiconductor light emitting device 2: Substrate 3: Undoped layer 4: N-type nitride semiconductor layer 5: Active layer 6: P-type nitride semiconductor layer 7: Undoped AlGaN layers 5a, 5c, 5e, 5g, 5i, 5k : Barrier layer 5b, 5d, 5f, 5h, 5j: Light emitting layer

Claims (1)

Nitride semiconductor light emitting device having active layer in which light emitting layer made of nitride semiconductor and barrier layer made of nitride semiconductor are alternately laminated between n type nitride semiconductor layer and p type nitride semiconductor layer Because
Of the barrier layers, a final barrier layer formed in contact with the p-type nitride semiconductor layer is made of a nitride semiconductor containing Al, and a C concentration contained in the final barrier layer is 5 × 10 ¹⁶ / cm ^3. A nitride semiconductor light emitting device characterized by:

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