JP2005109004A - Semiconductor light-emitting device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device which can be enhanced in output without increasing a series resistance, and to provide its manufacturing method. <P>SOLUTION: On an n-type GaAs substrate 1, an n-type AlGaInP clad layer 2, active layer 3, p-type AlGaInP clad layer 4, GaInP etching stopper layer 5, p-type AlGaInP clad layer 6, p-type GaInP layer 7, and p-type GaAs cap layer 8 are formed, in this order. The p-type AlGaInP clad layer 6 consists of two layers, having different Al composition ratio, that is, the p-type AlGaInP clad layer 6 consists of a p-type AlGaInP clad layer 6a and a p-type AlGaInP clad layer 6b which are formed, in this order on top of the GaInP etching stopper layer 5. Since the Al composition ratio of the p-type AlGaInP clad layer 6a is larger by 0.1-0.2 than that of the p-type AlGaInP clad layer 6b, the p-type AlGaInP clad layer 6a has a higher etching rate, with respect to a hydrochloric acid-based etchant than the p-type AlGaInP clad layer 6b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor light emitting device having a compound semiconductor layer and a method for manufacturing the same.

  Conventionally, light-emitting elements using AlGaInP semiconductors have been put to practical use as semiconductor light-emitting elements such as light-emitting diodes and semiconductor laser elements that generate red light (see, for example, Patent Document 1).

  The structure and manufacturing method of a conventional AlGaInP semiconductor laser element will be described with reference to FIGS.

  4 and 5 are schematic cross-sectional views showing the structure and manufacturing method of a conventional AlGaInP-based semiconductor laser device.

  As shown in FIG. 4A, on an n-type GaAs substrate 51, an n-type AlGaInP cladding layer 52, a GaInP active layer 53, a p-type AlGaInP cladding layer 54, a GaInP etching stopper layer 55, a p-type AlGaInP cladding layer 56, p A type GaInP layer 57 and a p-type GaAs cap layer 58 are sequentially formed.

  Next, as shown in FIG. 4B, a partial region of the p-type AlGaInP cladding layer 56, the p-type GaInP layer 57, and the p-type GaAs cap layer 58 is selectively etched using a mask. The ridge portion R is formed.

  Thereafter, as shown in FIG. 5C, an n-type GaAs current blocking layer 59 is formed on the etching stopper layer 55 and both side surfaces of the ridge portion R that are selectively exposed by the etching.

  Subsequently, as shown in FIG. 5D, a p-type GaAs contact layer 60 is formed on the p-type GaAs cap layer 58 and the n-type GaAs current blocking layer 59, and the p-type is formed on the p-type GaAs contact layer 60. An electrode 61 is formed, and an n-type electrode 62 is formed on the lower surface of the n-type GaAs substrate 51.

  Thereby, an AlGaInP-based semiconductor laser element that generates red laser light is obtained.

In the AlGaInP semiconductor laser element described above, by applying a voltage between the p-type electrode 61 and the n-type electrode 62, holes are injected from the p-type AlGaInP cladding layer 54 into the GaInP active layer 53, and the n-type. Electrons are injected from the AlGaInP cladding layer 52 into the GaInP active layer 53. As a result, laser oscillation occurs in the central portion (position where the ridge portion R is formed) of the GaInP active layer 53, and red laser light is generated.
JP-A-6-005968

  In recent years, there has been a demand for higher output of the semiconductor laser element as described above. In order to realize high output of the semiconductor laser device, it has been proposed to reduce the stripe width of the ridge portion R shown in FIG.

  As described above, the ridge portion R is formed by, for example, wet (chemical) etching of the p-type AlGaInP cladding layer 56, the p-type GaInP layer 57, and the p-type GaAs cap layer 58.

  Here, since the wet etching proceeds along the crystal orientation of each layer, if the stripe width W5 below the ridge portion R is reduced, the stripe width W4 above the ridge portion R is further reduced.

  In addition, when the ridge portion R is formed by dry etching, it is necessary to perform wet etching on the etched surface by dry etching in order to remove crystal defects on the etched surface generated by dry etching. As a result, when the stripe width W5 below the ridge portion R is reduced as described above, the stripe width W4 above the ridge portion R is further reduced.

  When the stripe width W4 above the ridge portion R is reduced, the series resistance of the semiconductor laser device is increased. As a result, the semiconductor laser element generates heat and its life is shortened.

  An object of the present invention is to provide a semiconductor light emitting device capable of realizing high output without increasing a series resistance and a method for manufacturing the same.

  A semiconductor light emitting device according to a first aspect of the present invention includes an active layer, a first cladding layer, and a second cladding layer composed of a stripe-shaped ridge formed on the first cladding layer in order. The second cladding layer includes a first semiconductor layer containing aluminum and gallium and a second semiconductor layer containing aluminum and gallium in this order from the first cladding layer side, and the aluminum composition ratio of the first semiconductor layer is It is larger than the aluminum composition ratio of the second semiconductor layer.

  Thereby, since the aluminum composition ratio of the first semiconductor layer is larger than the aluminum composition ratio of the second semiconductor layer, the etching of the first semiconductor layer is performed when the ridge portion is formed by etching in the second cladding layer. The rate is higher than the etch rate of the second semiconductor layer.

  As a result, the stripe width at the lower end of the ridge can be reduced while maintaining the stripe width at the upper end of the ridge. Therefore, an increase in series resistance due to a reduction in the stripe width of the ridge portion is prevented, and high output is realized. Further, since the series resistance is prevented, heat generation is suppressed, and a long life is realized.

  The first semiconductor layer may further include indium and phosphorus, and the second semiconductor layer may further include indium and phosphorus. In this case, an AlGaInP-based semiconductor light emitting device with high output and long life is realized.

  An etching control layer provided between the first cladding layer and the second cladding layer and having an aluminum composition ratio smaller than that of the first semiconductor layer may be further provided. In this case, since the progress of the etching is controlled by the etching control layer, the etching can be stopped at the etching control layer without etching the first cladding layer.

  The etching control layer may be made of a semiconductor containing gallium, indium and phosphorus. In this case, since the etching rate of the etching control layer is lower than the etching rate of the second cladding layer, the etching can be accurately stopped at the etching control layer without etching the first cladding layer.

  The aluminum composition ratio of the first semiconductor layer may be larger in the range of 0.1 to 0.2 than the aluminum composition ratio of the second semiconductor layer.

  In this case, since the difference between the aluminum composition ratio of the first semiconductor layer and the aluminum composition ratio of the second semiconductor layer is 0.1 or more, when the ridge portion is formed by etching, the first semiconductor layer The etching rate can be made sufficiently higher than the etching rate of the second semiconductor layer.

  Moreover, since the difference between the aluminum composition ratio of the first semiconductor layer and the aluminum composition ratio of the second semiconductor layer is 0.2 or less, a decrease in the dopant doping amount due to excess aluminum is prevented. Thereby, the increase in resistance of the first semiconductor layer is suppressed. Furthermore, an increase in light absorption by the first semiconductor layer is suppressed.

  The aluminum composition ratio of the first semiconductor layer may be not less than 0.7 and not more than 0.8.

  In this case, when the aluminum composition ratio of the first semiconductor layer is 0.7 or more, the light confinement effect in the active layer by the first and second semiconductor layers is sufficiently increased.

  In addition, since the aluminum composition ratio of the first semiconductor layer is 0.8, light generated by the active layer is difficult to be absorbed by the ridge portion. This prevents the laser light spot from becoming an ellipse. Further, since the decrease of the dopant doping amount due to excess aluminum is prevented, the resistance of the first semiconductor layer is prevented from being increased. In addition, since the etching rate is prevented from becoming excessively high, the shape of the ridge portion can be easily controlled.

  The thickness of the first semiconductor layer may be not less than 0.1 μm and not more than 0.3 μm. In this case, since the first semiconductor layer has a higher resistance than the second semiconductor layer, an increase in series resistance is suppressed when the thickness of the first semiconductor layer is 0.3 μm or less. Moreover, it becomes easy to control the shape of the ridge portion. Furthermore, when the thickness of the first semiconductor layer is 0.1 μm or more, the stripe width at the lower end of the ridge portion can be easily reduced.

  According to a second aspect of the present invention, there is provided a method for manufacturing a semiconductor light emitting device, comprising: forming an active layer; forming a first cladding layer on the active layer; and forming a second cladding layer on the first cladding layer. Forming a stripe-shaped ridge portion by etching the second clad layer except for the stripe-shaped region, and forming the second clad layer includes aluminum and A step of forming a first semiconductor layer made of a semiconductor containing gallium, and a step of forming a second semiconductor layer made of a semiconductor containing aluminum and gallium, wherein the aluminum composition ratio of the first semiconductor layer is second. This is larger than the aluminum composition ratio of the semiconductor layer.

  In the method for manufacturing a semiconductor light emitting device according to the second invention, an active layer is formed, a first cladding layer is formed on the active layer, a second cladding layer is formed on the first cladding layer, The second clad layer is etched except for the stripe region, whereby a stripe ridge portion is formed.

  In the second cladding layer, a first semiconductor layer having a predetermined aluminum composition ratio is formed, and a second semiconductor layer having an aluminum composition ratio smaller than that of the first semiconductor layer is formed.

  Thereby, since the aluminum composition ratio of the first semiconductor layer is larger than the aluminum composition ratio of the second semiconductor layer, the etching of the first semiconductor layer is performed when the ridge portion is formed by etching in the second cladding layer. The rate is higher than the etch rate of the second semiconductor layer.

  As a result, the stripe width at the lower end of the ridge can be reduced while maintaining the stripe width at the upper end of the ridge. Therefore, an increase in series resistance due to a reduction in the stripe width of the ridge portion is prevented, and high output is realized. Further, since the series resistance is prevented, heat generation is suppressed, and a long life is realized.

  In the semiconductor light emitting device according to the present invention, since the aluminum composition ratio of the first semiconductor layer is larger than the aluminum composition ratio of the second semiconductor layer, when forming the ridge portion by etching in the second cladding layer, The etching rate of the first semiconductor layer is higher than the etching rate of the second semiconductor layer.

  As a result, the stripe width at the lower end of the ridge can be reduced while maintaining the stripe width at the upper end of the ridge. Therefore, an increase in series resistance due to a reduction in the stripe width of the ridge portion is prevented, and high output is realized. Further, since the series resistance is prevented, heat generation is suppressed, and a long life is realized.

  Hereinafter, a semiconductor light emitting device and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to FIGS. In the following description, an AlGaInP semiconductor laser element will be described as the semiconductor light emitting element.

  1 and 2 are schematic cross-sectional views showing the structure and manufacturing method of an AlGaInP-based semiconductor laser device according to an embodiment of the present invention.

  As shown in FIG. 1A, an n-type AlGaInP cladding layer 2 having a thickness of 1.5 μm, a GaInP active layer 3, a p-type AlGaInP cladding layer 4 having a thickness of 0.2 μm, and a GaInP on an n-type GaAs substrate 1. The etching stopper layer 5, the p-type AlGaInP cladding layer 6 having a thickness of 1.3 μm, the p-type GaInP layer 7 and the p-type GaAs cap layer 8 having a thickness of 0.3 μm are sequentially formed by MOCVD (metal organic chemical vapor deposition). Form.

  Here, as the n-type GaAs substrate 1, an off-substrate having a crystal growth surface inclined in a predetermined direction from the (0001) plane is used.

  The p-type AlGaInP clad layer 6 includes a p-type AlGaInP clad layer 6a and a p-type AlGaInP clad layer 6b in this order from the GaInP etching stopper layer 5 side. The p-type AlGaInP clad layer 6a has a thickness of 0.3 μm, and the p-type AlGaInP clad layer 6b has a thickness of 1.0 μm.

  The Al composition ratio of the p-type AlGaInP cladding layer 6a is larger than the Al composition ratio of the p-type AlGaInP cladding layer 6b. The Al composition ratio of the p-type AlGaInP clad layer 6a is preferably 0.1 to 0.2 larger than the Al composition ratio of the p-type AlGaInP clad layer 6b, and is preferably in the range of 0.7 to 0.8.

Here, for example, the composition ratio of the n-type AlGaInP cladding layer 2 and the p-type AlGaInP cladding layers 4 and 6b is Al _0.6 Ga _0.3 In _0.5 P _0.5 , and the composition ratio of the p-type AlGaInP cladding layer 6a is Al _0.7 Ga _0.3 In _0.5 P _0.5 .

  The thickness of the p-type AlGaInP cladding layer 6a is not limited to 0.3 μm, but is preferably 100 nm (= 0.1 μm) or more and 300 nm (= 0.3 μm) or less.

  Details of the Al composition ratio and thickness of the p-type AlGaInP cladding layer 6a will be described later.

Next, as shown in FIG. 1B, a striped SiO ₂ film 9 having a thickness of 0.2 μm is formed on the p-type GaAs cap layer 8 as a mask, and the p-type is interposed via the SiO ₂ film 9. Partial regions of the GaAs cap layer 8, the p-type GaInP layer 7 and the p-type AlGaInP clad layer 6 are selectively wet (chemical) etched to form a stripe-shaped ridge portion R. In this wet etching, an etching solution corresponding to each layer is used.

  For example, the p-type GaAs cap layer 8 is selectively etched with a phosphoric acid based etchant containing phosphoric acid, hydrogen peroxide and methanol at 10: 3: 10. Further, the p-type GaInP layer 7 is selectively etched with a hydrobromic acid-based etchant containing hydrogen bromide and water at a ratio of 30: 1. Further, the p-type AlGaInP clad layer 6 (p-type AlGaInP clad layers 6a and 6b) is selectively etched with a hydrochloric acid-based etchant containing hydrochloric acid and water at a ratio of 3: 1.

  Here, the wet etching proceeds along the crystal orientation of the p-type GaAs cap layer 8, the p-type GaInP layer 7 and the p-type AlGaInP cladding layer 6.

  Since the n-type GaAs substrate 1 is the above-described off-substrate, both side surfaces of the ridge portion R are inclined asymmetrically by etching as shown in FIG.

  Thereafter, as shown in FIG. 2C, a block layer made of, for example, an AlInP layer 11 and a GaAs layer 12 is formed on the GaInP etching stopper layer 5 and both side surfaces of the ridge portion R that are selectively exposed by the etching. B is formed by MOCVD.

Subsequently, as shown in FIG. 2D, the SiO ₂ film 9 is removed by etching using a hydrofluoric acid-based etching solution or the like, and a p-type GaAs contact is formed on the GaAs layer 12 and the p-type GaAs cap layer 8. Layer 13 is formed by MOCVD.

  Finally, a p-type electrode 14 is formed on the p-type GaAs contact layer 13 by sputtering or vacuum deposition, and an n-type electrode 15 is formed on the lower surface of the n-type GaAs substrate 1.

  Thereby, an AlGaInP-based semiconductor laser element that generates red laser light is obtained. In the AlGaInP-based semiconductor laser device obtained as described above, holes are injected from the p-type AlGaInP cladding layer 4 to the GaInP active layer 3 by applying a voltage to the p-type electrode 14 and the n-type electrode 15, and n Electrons are injected from the type AlGaInP cladding layer 2 into the GaInP active layer 3. As a result, red laser light is generated from the GaInP active layer 3.

  FIG. 3 is a schematic diagram showing a state of wet etching when forming the ridge portion R of FIG.

  The etching rate (reaction rate) of the p-type AlGaInP clad layer 6 by the hydrochloric acid-based etchant increases when the Al composition ratio is large, and decreases when the Al composition ratio is small.

  In the AlGaInP-based semiconductor laser device according to the present embodiment, the p-type AlGaInP cladding layer 6 of the ridge portion R includes p-type AlGaInP cladding layers 6a and 6b having different Al composition ratios in order.

  The Al composition ratio of the p-type AlGaInP cladding layer 6a below the ridge portion R is larger than that of the upper p-type AlGaInP cladding layer 6b. Thereby, the etching rate of the p-type AlGaInP cladding layer 6a is higher than the etching rate of the p-type AlGaInP cladding layer 6b. That is, the etching rate immediately before the end of etching of the lower portion of the ridge portion R is increased. Accordingly, as shown in FIG. 3A, the stripe width W2 at the lower end of the ridge portion R can be reduced while maintaining the stripe width W1 at the upper end of the ridge portion R large.

  Therefore, high output can be achieved without increasing the series resistance of the AlGaInP semiconductor laser element. Further, since the series resistance does not increase, heat generation is suppressed and a long life is realized.

  Here, the Al composition ratio of the above-described p-type AlGaInP cladding layer 6a is preferably 0.1 to 0.2 larger than the Al composition ratio of the p-type AlGaInP cladding layer 6b, and is preferably 0.7 to 0.8. The reason will be explained.

  When the difference in Al composition ratio between the p-type AlGaInP cladding layer 6a and the p-type AlGaInP cladding layer 6b is smaller than 0.1, the etching rate of the p-type AlGaInP cladding layer 6a and the etching rate of the p-type AlGaInP cladding layer 6B Is too small, and the stripe width at the lower end of the p-type AlGaInP cladding layer 6a is larger than the stripe width at the lower end of the p-type AlGaInP cladding layer 6b. Accordingly, the stripe width W2 at the lower end of the ridge portion R cannot be reduced while the stripe width W1 at the upper end of the ridge portion R is maintained large. Therefore, the difference between the Al composition ratio of the p-type AlGaInP cladding layer 6a and the Al composition ratio of the p-type AlGaInP cladding layer 6b is preferably 0.1 or more.

  On the other hand, if the Al composition ratio of the p-type AlGaInP clad layer 6b is smaller than 0.6, the difference between the refractive index of the GaInP active layer 3 and the refractive index of the p-type AlGaInP clad layer 6b becomes small. The light confinement effect is reduced. Therefore, the Al composition ratio of the p-type AlGaInP cladding layer 6b is preferably 0.6 or more.

  As described above, the difference between the Al composition ratio of the p-type AlGaInP cladding layer 6a and the Al composition ratio of the p-type AlGaInP cladding layer 6b is preferably 0.1 or more, and the Al composition of the p-type AlGaInP cladding layer 6b Since the ratio is preferably 0.6 or more, the Al composition ratio of the p-type AlGaInP cladding layer 6a is preferably 0.7 or more.

  If the Al composition ratio of the p-type AlGaInP cladding layer 6a is greater than 0.8, light generated by the GaInP active layer 3 is easily absorbed by the p-type AlGaInP cladding layer 6a. Therefore, the spot shape of the laser light becomes an ellipse.

  Furthermore, when the Al composition ratio of the p-type AlGaInP cladding layer 6a is greater than 0.8, the amount of dopant added to the p-type AlGaInP cladding layer 6a is limited, and the resistance increases. As a result, the p-type AlGaInP cladding layer 6a is likely to generate heat.

  Further, as the etching rate is significantly increased, the side surface of the p-type AlGaInP cladding layer 6a is side-etched inward from the lower end of the p-type AlGaInP cladding layer 6b as shown by a broken line TO in FIG. It is formed. As a result, the resistance of the p-type AlGaInP cladding layer 6a is increased.

  Therefore, the Al composition ratio of the p-type AlGaInP cladding layer 6a is preferably 0.8 or less. As described above, since the Al composition ratio of the p-type AlGaInP cladding layer 6b is preferably 0.6 or more, the Al composition ratio of the p-type AlGaInP cladding layer 6a and the Al composition ratio of the p-type AlGaInP cladding layer 6b. And the difference is preferably 0.2 or less.

  As a result, the Al composition ratio of the p-type AlGaInP cladding layer 6a is 0.1 to 0.2 larger than the Al composition ratio of the p-type AlGaInP cladding layer 6b, and is in the range of 0.7 to 0.8. Is preferred.

  In FIG. 3, the reason why the thickness H1 of the p-type AlGaInP cladding layer 6a is preferably not less than 100 nm and not more than 300 nm will be described.

  Since the resistance of the p-type AlGaInP cladding layer 6a is larger than that of the p-type AlGaInP cladding layer 6b, the series resistance increases when the thickness H1 of the p-type AlGaInP cladding layer 6a is greater than 300 nm. Further, since the etching rate of the p-type AlGaInP cladding layer 6a is higher than the etching rate of the p-type AlGaInP cladding layer 6b, if the thickness H1 is larger than 300 nm, it becomes difficult to control the shape during etching.

  If the thickness H1 of the p-type AlGaInP cladding layer 6a is smaller than 100 nm, the stripe width W2 at the lower end of the ridge portion R cannot be reduced while maintaining the stripe width W1 at the upper end of the ridge portion R large.

  For these reasons, the thickness H1 of the p-type AlGaInP cladding layer 6a is preferably 100 nm or more and 300 nm or less.

  In the present embodiment, the etching at the time of forming the ridge portion R is performed by wet etching. However, the present invention is not limited to this, and dry etching and wet etching may be performed in combination. Even in this case, the same effect as described above can be obtained.

  In the present embodiment, the thickness of each layer forming the AlGaInP-based semiconductor laser element is shown, but the thickness of each layer is not particularly limited except for the thickness of the p-type AlGaInP cladding layer 6a.

  Further, the n-type AlGaInP cladding layer 2, the GaInP active layer 3, the p-type AlGaInP cladding layer 4, the GaInP etching stopper layer 5, the p-type AlGaInP cladding layer 6, the p-type GaInP layer 7, the p-type GaAs cap layer 8, and the AlInP layer 11 In order to form the GaAs layer 12 and the p-type GaAs contact layer 13, other epitaxial growth methods such as the MBE method (molecular beam epitaxy method) may be used instead of the MOCVD method.

  As described above, in one embodiment of the present invention, the GaInP active layer 3 corresponds to the active layer, the n-type AlGaInP cladding layer 2 and the p-type AlGaInP cladding layer 4 correspond to the first cladding layer, and the p-type AlGaInP cladding. The layer 6 corresponds to a second cladding layer, the p-type AlGaInP cladding layer 6a corresponds to a first semiconductor layer, and the p-type AlGaInP cladding layer 6b corresponds to a second semiconductor layer. The ridge portion R corresponds to a ridge portion, and the GaInP etching stopper layer 5 corresponds to an etching control layer.

[Example]
In this example, an AlGaInP-based semiconductor laser device having the same structure as that of the above embodiment is manufactured by the same manufacturing method as above, and the stripe width W1 at the upper end of the ridge portion R and the stripe width at the lower end of the ridge portion R in FIG. W2 was measured.

  As a result, the stripe width W1 at the upper end of the ridge portion R was 1.5, and the stripe width W2 at the lower end of the ridge portion R was 2.5. The ratio of the stripe width W2 at the lower end of the ridge portion R to the stripe width W1 at the upper end of the ridge portion R (hereinafter referred to as the ridge portion vertical ratio) was 0.6.

[Comparative example]
In the comparative example, an AlGaInP-based semiconductor laser device having the same structure as that of the example except for the following points is manufactured by the same manufacturing method as described above, and the stripe width W1 at the upper end of the ridge portion R and the lower end of the ridge portion R in FIG. The stripe width W3 was measured.

  In this comparative example, the p-type AlGaInP clad layer 6 in the ridge portion R is formed of only the p-type AlGaInP clad layer 6b. Therefore, the etching rate of the p-type AlGaInP cladding layer 6 does not change when the ridge portion R is formed (during etching). As a result, the shape of the lower side surface of the ridge portion R is formed as shown by a broken line NO in FIG.

  As a result, the stripe width W1 at the upper end of the ridge portion R was 0.7, and the stripe width W3 at the lower end of the ridge portion R was 2.5. The top / bottom ratio of the ridge portion was 0.28.

[Evaluation]
As described above, when the ridge portion R includes the p-type AlGaInP cladding layers 6a and 6b having different etching rates in order, the ridge portion top-to-bottom ratio as compared with the case where the ridge portion R is composed only of the p-type AlGaInP cladding layer 6b. Was found to be larger.

  INDUSTRIAL APPLICABILITY The present invention is useful as a high-power AlGaInP-based semiconductor light-emitting element that generates red laser light and a method for manufacturing the same.

It is typical sectional drawing which shows the structure and manufacturing method of the AlGaInP type | system | group semiconductor laser element which concerns on one embodiment of this invention. It is typical sectional drawing which shows the structure and manufacturing method of the AlGaInP type | system | group semiconductor laser element which concerns on one embodiment of this invention. It is a schematic diagram which shows the mode of the wet etching at the time of ridge part formation of FIG.1 (b). It is typical sectional drawing which shows the structure and manufacturing method of the conventional AlGaInP type | system | group semiconductor laser element. It is typical sectional drawing which shows the structure and manufacturing method of the conventional AlGaInP type | system | group semiconductor laser element.

Explanation of symbols

1 n-type GaAs substrate 1
2 n-type AlGaInP cladding layer 3 GaInP active layer 4 p-type AlGaInP cladding layer 5 GaInP etching stopper layer 6 p-type AlGaInP cladding layer 7 p-type GaInP layer 8 p-type GaAs cap layer 8
9 SiO ₂ film 11 AlInP layer 12 GaAs layer B Block layer R Ridge portion W1, W2, W3 Stripe width

Claims (6)

An active layer,
A first cladding layer;
A second clad layer composed of a stripe-shaped ridge formed on the first clad layer in order;
The second clad layer includes a first semiconductor layer containing aluminum and gallium, and a second semiconductor layer containing aluminum and gallium in order from the first clad layer side,
The semiconductor light emitting element, wherein the aluminum composition ratio of the first semiconductor layer is larger than the aluminum composition ratio of the second semiconductor layer. The first semiconductor layer further comprises indium and phosphorus;
The semiconductor light emitting element according to claim 1, wherein the second semiconductor layer further contains indium and phosphorus. 2. The etching control layer according to claim 1, further comprising an etching control layer provided between the first cladding layer and the second cladding layer and having an aluminum composition ratio smaller than that of the first semiconductor layer. Semiconductor light emitting device. 4. The semiconductor light emitting device according to claim 3, wherein the etching control layer is made of a semiconductor containing gallium, indium and phosphorus. 5. The aluminum composition ratio of the first semiconductor layer is larger than the aluminum composition ratio of the second semiconductor layer within a range of 0.1 to 0.2. 5. The semiconductor light emitting element as described. Forming an active layer;
Forming a first cladding layer on the active layer;
Forming a second cladding layer on the first cladding layer,
Forming a stripe-shaped ridge portion by etching the second cladding layer except for a stripe-shaped region,
The step of forming the second cladding layer includes:
Forming a first semiconductor layer made of a semiconductor containing aluminum and gallium;
Forming a second semiconductor layer made of a semiconductor containing aluminum and gallium,
A method for manufacturing a semiconductor light emitting element, wherein an aluminum composition ratio of the first semiconductor layer is larger than an aluminum composition ratio of the second semiconductor layer.

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