JP2009266891A - Semiconductor laser and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser which reduces a leak current, and a method of manufacturing the same. <P>SOLUTION: The semiconductor laser 100 has a current leak layer 108 formed between a first-conductivity-type current block layer 107 and a semiconductor mesa 105 and between the first-conductivity-type current block layer 107 and a second-conductivity-type current block layer 106. The thin current leak layer 108 of not larger than 0.2 μm in thickness serves as a leak path for a hole current from a second-conductivity-type clad layer 104 to the second-conductivity-type current block layer 106. Thus, the hole current is caused to flow to the leak path of not larger than 0.2 μm in thickness to increase electric resistance. Consequently, the leak current of a buried section comprising the first-conductivity-type current block layer 107 and second-conductivity-type block layer 106 is reducible. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor laser and a method for manufacturing the same.

Conventionally, as shown in Patent Document 1 or 2, for example, an active layer and its peripheral layer are etched in a narrow mesa stripe shape with a width of about 1 μm, and both side surfaces are embedded with a current blocking layer made of a semiconductor layer, so-called buried hetero 2. Description of the Related Art A semiconductor laser having a structure (Buried Heterostructure structure) (hereinafter referred to as “BH laser”) is known.
Japanese Patent Publication No. 4-82074 Japanese Patent Publication No. 10-346842

  FIG. 8 shows a conventional pn buried type BH laser 300. As shown in FIG. 8, the BH laser 300 includes an n-InP substrate 301, an n-InP cladding layer 302, an active layer (MQW) 303, a p-InP current blocking layer 304, an n-InP current blocking layer 305, a p- InP clad layer 306, InGaAs contact layer 307, SiO2 insulating layer 308, p-electrode 309, and n-electrode 310 are provided. In this BH laser 300, in order to efficiently inject current into the active layer 303, a thyristor structure including a p-InP current blocking layer 304 and an n-InP current blocking layer 305 is provided beside the active layer 303 to It is carried out. Thereby, a current confinement structure in the active layer 303 is achieved.

  However, in this structure, as shown in FIG. 8, there is a hole current leak path a from the p-InP cladding layer 306 to the p-InP current blocking layer 304 due to the structure, It is not. The leak path a corresponds to the base current in the thyristor structure, and the thyristor is turned on when the base current flows more than a certain value. In the ON state, current flows into the current blocking layer itself, the current in the leak path b increases, and there are problems such as various characteristics of the BH laser 300, particularly characteristics such as light output at high temperature and slope efficiency. .

  Accordingly, the present invention has been made in view of the above, and an object thereof is to provide a semiconductor laser capable of reducing leakage current and a method for manufacturing the same.

  In order to solve the above-described problems, a semiconductor laser according to the present invention includes a semiconductor mesa provided on a substrate and including an active layer, and a second conductivity type current blocking layer provided on the substrate and embedded in the semiconductor mesa. A first conductivity type current blocking layer embedded on the semiconductor mesa, and provided on the active layer and the first conductivity type current blocking layer. A semiconductor laser including a second conductivity type cladding layer and a contact layer provided on the second conductivity type cladding layer, wherein the semiconductor laser is between the first conductivity type current blocking layer and the semiconductor mesa; and A current leakage layer made of a second conductivity type semiconductor layer having a thickness of 0.2 μm or less is included between the first conductivity type current block layer and the second conductivity type current block layer.

  In the semiconductor laser manufacturing method of the present invention, a first III-V compound semiconductor layer for an active layer is grown on a substrate by metal organic vapor phase epitaxy, and the first III-V compound semiconductor layer is formed on the first III-V compound semiconductor layer. A first step of forming a semiconductor mesa by dry etching using the formed stripe-shaped mask; and a second conductivity type current blocking layer for embedding the semiconductor mesa on the substrate and beside the semiconductor mesa A second step of growing the second III-V compound semiconductor layer by metal organic vapor phase epitaxy, and a second step of removing the second III-V compound semiconductor layer grown beside the semiconductor mesa in the second step by etching. And a third III-V compound semiconductor for a second conductivity type current leakage layer having a thickness of 0.2 μm or less on the second III-V compound semiconductor layer and on the side of the semiconductor mesa exposed by the third step. And a fourth step of growing the fourth III-V compound semiconductor layer for the first conductivity type current blocking layer in contact with the third III-V compound semiconductor layer. And a fifth III-V compound semiconductor layer for a second conductivity type cladding layer on the active layer and on the fourth III-V compound semiconductor layer after removing the mask. A sixth step of growing by metal organic vapor phase epitaxy, and a sixth III-V compound semiconductor layer for a second conductivity type contact layer on the fifth III-V compound semiconductor layer by metal organic vapor phase epitaxy. And a seventh step of growing.

  According to the semiconductor laser and the manufacturing method thereof of the present invention, between the first conductivity type current block layer and the semiconductor mesa and between the first conductivity type current block layer and the second conductivity type current block layer. Then, a current leakage layer composed of a thin second conductive semiconductor layer having a thickness of 0.2 μm or less is formed. This thin current leak layer having a thickness of 0.2 μm or less serves as a leak path for hole current from the second conductivity type cladding layer to the second conductivity type current block layer. In this way, by passing a hole current through a narrow leak path having a thickness of 0.2 μm or less, the electrical resistance can be increased. As a result, the buried portion composed of the first conductivity type current block layer and the second conductivity type current block layer Leakage current can be reduced. Therefore, it is possible to prevent the thyristor structure from being turned on, and as a result, it is possible to prevent deterioration of various characteristics of the semiconductor laser, particularly characteristics such as light output at a high temperature and slope efficiency.

In the semiconductor laser of the present invention, the impurity concentration in the current leak layer is preferably 1 × 10 ¹⁷ cm ⁻³ or less.

In the fourth step of the method of manufacturing a semiconductor laser according to the present invention, the third III-V compound semiconductor is adjusted so that the impurity concentration of the third III-V compound semiconductor layer is 1 × 10 ¹⁷ cm ⁻³ or less. It is preferred to grow the layer.

In order to reduce the leakage current by making the hole current path high resistance, it is preferable that the impurity concentration of the current leakage layer serving as the hole current leakage path is 1 × 10 ¹⁷ cm ⁻³ or less. If the impurity concentration of the current leak layer is set in this manner, diffusion of dopant from the buried portion to the active layer can be suppressed, and non-radiative recombination can be reduced.

  Furthermore, by setting the impurity concentration of the current leak layer to zero, the buried portion can have a pin structure. In this case, the capacity of the semiconductor laser can be reduced, and a laser structure excellent in high-speed response can be obtained. Note that, for example, the conventional pn buried semiconductor laser described in Patent Document 2 has a large capacity and is not suitable for high-speed driving compared to a semi-insulating buried (Fe-InP, etc.) semiconductor laser. There is. This is because, for example, a reverse bias is applied to the interface of the pn block and a depletion layer is formed, so that the portion becomes a capacitance, and the capacitance increases as a whole. The semiconductor laser and the manufacturing method thereof according to the present invention solve the problems of the conventional pn buried type semiconductor laser by the above structure.

  In the semiconductor mesa of the semiconductor laser of the present invention, a first conductivity type cladding layer is further formed under the active layer, and a height of the upper surface of the second conductivity type current block layer from the substrate is further increased. However, it is preferable that the height of the upper surface of the first conductivity type cladding layer is not less than the height from the substrate.

  Further, in the first step of the semiconductor laser manufacturing method of the present invention, before the first III-V compound semiconductor layer is grown, the seventh III-V compound semiconductor layer for the first conductivity type cladding layer is organically formed. In the second step, the height of the upper surface of the second III-V compound semiconductor layer from the substrate is higher than the height of the upper surface of the seventh III-V compound semiconductor layer from the substrate. It is preferable to grow the second III-V compound semiconductor layer so as to be more than that.

Thus, by setting the height of the second conductivity type current blocking layer to be equal to or higher than the height of the first conductivity type cladding layer, the first conductivity type current blocking layer and the first conductivity type cladding layer are only current leakage layers. It is possible to prevent facing each other. With the above structure, the first conductivity type current block layer and the first conductivity type clad layer face each other via the second conductivity type current block layer or the active layer in addition to the current leak layer. As described above, the distance between the first conductivity type current blocking layer and the first conductivity type cladding layer is increased so that the impurity concentration in the current leak layer is 1 even if the thickness of the current leak layer is 0.2 μm or less. Even when it is less than × 10 ¹⁷ cm ⁻³ and low and zero, it is possible to suppress current leakage from the first conductivity type current blocking layer to the first conductivity type cladding layer.

  In the third step of the semiconductor laser manufacturing method of the present invention, it is preferable to perform the etching using a chlorine-based gas.

  By using an anisotropic etching gas in this way, only the ones beside the semiconductor mesa among the second III-V compound semiconductor layers grown in the second step can be removed.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor laser which can reduce a leakage current, and its manufacturing method can be provided.

  Preferred embodiments of a semiconductor laser and a manufacturing method thereof according to the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(Structure of semiconductor laser 100)
FIG. 1 is a perspective view showing a part of a semiconductor laser 100 according to the present embodiment, and FIG. 2 is a sectional view taken along line II-II in FIG. The semiconductor laser 100 is a semiconductor laser (BH laser) having a so-called buried heterostructure structure (BuriedHeterostructure structure). In the semiconductor laser 100, a first conductivity type cladding layer 102 is provided on the main surface 101 a of the first conductivity type substrate 101. The first conductivity type substrate 101 is, for example, an n-type InP substrate. The first conductivity type cladding layer 102 is, for example, an n-type InP cladding layer.

  A light emitting region 103 is provided on the first conductivity type cladding layer 102. The light emitting region 103 has, for example, a multiple quantum well (MQW) structure and includes an active layer.

  A first region 104 a of the second conductivity type cladding layer 104 is provided on the light emitting region 103. The second conductivity type cladding layer 104 is, for example, a p-type InP cladding layer. The first conductivity type cladding layer 102, the light emitting region 103, and the first region 104 a of the second conductivity type cladding layer 104 form a semiconductor mesa 105. The semiconductor mesa 105 has, for example, an elongated stripe shape.

  A second conductivity type current blocking layer 106 and a first conductivity type current blocking layer 107 are sequentially provided on the substrate 101 so as to embed the semiconductor mesa 105. The second conductivity type current blocking layer 106 is, for example, a p-type InP current blocking layer. The first conductivity type current blocking layer 107 is, for example, an n-type InP current blocking layer.

A current leakage layer 108 is formed between the first conductivity type current block layer 107 and the semiconductor mesa 105 and between the first conductivity type current block layer 107 and the second conductivity type current block layer 106. The current leak layer 108 is made of a second conductive semiconductor layer having a thickness of 0.2 μm or less, and is a p-type InP current leak layer, for example. The impurity concentration in the current leak layer 108 is preferably 1 × 10 ¹⁷ cm ⁻³ or less.

  The second conductivity type cladding layer 104 further includes a second region 104 b, and the second region 104 b is provided over the first region 104 a and the first conductivity type current blocking layer 107. A contact layer 109 is provided on the second region 104 b of the second conductivity type cladding layer 104.

On the contact layer 109, for example, an insulating film 110 for enhancing current confinement in the semiconductor mesa 105 is provided. The insulating film 110 is a dielectric such as SiN or SiO ₂ .

  A first metal electrode (for example, an anode electrode) 111 is provided on the contact layer 109 and the insulating film 110. A second metal electrode (for example, cathode electrode) 112 is provided on the back surface 101 b of the substrate 101.

(Operation and Effect of Semiconductor Laser 100)
Next, functions and effects of the semiconductor laser 100 according to this embodiment will be described. According to the semiconductor laser 100, the current leakage layer 108 is provided between the first conductivity type current blocking layer 107 and the semiconductor mesa 105 and between the first conductivity type current blocking layer 107 and the second conductivity type current blocking layer 106. Is formed. This thin current leak layer 108 having a thickness of 0.2 μm or less serves as a leak path A for hole current from the second conductivity type cladding layer 104 to the second conductivity type current block layer 106. FIG. 4 shows a leak path A in the semiconductor laser 100. In this way, by passing the hole current through the narrow leak path A having a thickness of 0.2 μm or less, the electric resistance can be increased. As a result, the first conductivity type current block layer 107 and the second conductivity type current block layer 106 The leakage current in the buried portion can be reduced. Therefore, it is possible to prevent the thyristor structure from being turned on, and as a result, it is possible to prevent deterioration of various characteristics of the semiconductor laser 100, particularly characteristics such as light output at a high temperature and slope efficiency.

Here, in order to reduce the leak current by making the leak path A of the hole current high resistance, the impurity concentration of the current leak layer 108 serving as the leak path A of the hole current is set to 1 × 10 ¹⁷ cm ⁻³ or less. Is preferred. If the impurity concentration of the current leak layer 108 is set in this way, the diffusion of the dopant from the buried portion formed of the first conductivity type current block layer 107 and the second conductivity type current block layer 106 to the light emitting region 103 including the active layer is suppressed. , Non-radiative recombination can be reduced.

  Further, by setting the impurity concentration of the current leak layer 108 to zero, the buried portion can have a pin structure. In this case, the capacity of the semiconductor laser 100 can be reduced, and a laser structure excellent in high-speed response can be obtained. Note that, for example, the conventional pn buried semiconductor laser described in Patent Document 2 has a large capacity and is not suitable for high-speed driving compared to a semi-insulating buried (Fe-InP, etc.) semiconductor laser. There is. This is because, for example, a reverse bias is applied to the interface of the pn block and a depletion layer is formed, so that the portion becomes a capacitance, and the capacitance increases as a whole. The semiconductor laser 100 of the present embodiment solves the problems of the conventional pn buried type semiconductor laser with the above structure.

(Semiconductor laser 200)
As described above, the structure of the semiconductor laser 100 of the present embodiment has been described with reference to FIGS. 1 and 2, but the structure of the semiconductor laser of the present invention is not limited to this. Referring back to FIG. 3, the leak path C is shown. The leak path C is a leak path from the first conductivity type current block layer 107 to the first conductivity type clad layer 102. In the above-described semiconductor laser 100, the lower the impurity concentration in the current leak layer 108 is, or the thinner the current leak layer 108 is, the higher the resistance of the current leak layer 108 becomes. It is thought that it contributes to the reduction of. However, on the other hand, the impurity concentration of the current leak layer 108 is reduced or the thickness of the current leak layer 108 is reduced. In other words, the first conductivity type current block layer 107 and the first conductivity type clad. It can be said that the concentration of the second conductivity type impurity between the layers 102 is reduced, or the first conductivity type current blocking layer 107 and the first conductivity type cladding layer 102 are close to each other. As a result, a trade-off is considered that the current in the leak path C shown in FIG. 3 is greatly increased by reducing the impurity concentration of the current leak layer 108 and reducing the thickness of the current leak layer 108. Therefore, hereinafter, the structure of the semiconductor laser 200 improved as described above will be described with reference to FIGS.

  FIG. 4 is a cross-sectional view showing the structure of the semiconductor laser 200 of this embodiment. In the semiconductor laser 200 shown in FIG. 4, as in the semiconductor laser 100 shown in FIG. 1, in the semiconductor mesa 205, the first conductivity type cladding layer 202 is formed under the light emitting region 203 including the active layer. However, the height D1 of the upper surface 206a of the second conductivity type current blocking layer 206 is higher than the height D2 of the upper surface 202a of the first conductivity type cladding layer 202, which is different from the semiconductor laser 100 shown in FIG. Alternatively, as shown in FIG. 5, in the semiconductor laser 200, the height D1 of the second conductivity type current blocking layer 206 and the height D2 of the first conductivity type cladding layer 202 may be set to substantially the same height. Note that the height D1 and the height D2 in the present embodiment are set to a height based on the back surface 201b of the substrate 201 for convenience of explanation.

As shown in FIG. 4, the height D1 of the second conductivity type current blocking layer 206 is set to be higher than the height D2 of the first conductivity type cladding layer 202, whereby the first conductivity type current blocking layer 207 and the first conductivity type are blocked. It is possible to prevent the clad layer 202 from facing the current leak layer 208 only. With the above structure, the first conductivity type current block layer 207 and the first conductivity type cladding layer 202 face each other via the second conductivity type current block layer 206 or the light emitting region 203 in addition to the current leak layer 208. . Thus, by distant between the first conductivity type current blocking layer 207 and the first conductivity type cladding layer 202, even if the thickness of the current leakage layer 208 is 0.2 μm or less, Even when the impurity concentration is 1 × 10 ¹⁷ cm ⁻³ or less and low and even zero, current leakage from the first conductivity type current blocking layer 207 to the first conductivity type cladding layer 202 can be suppressed. Of course, the same applies to the structure shown in FIG.

  Here, when the impurity concentration in the current leak layer 208 is zero, the current leak layer 208 is not a p-InP layer but an i-InP layer. Generally, when forming a p-InP layer beside an active layer, Zn is often used as a dopant for p. However, since Zn easily diffuses into the active layer, there are known problems such as non-radiative recombination increases with the diffusion of Zn into the active layer, and as a result, the threshold value deteriorates. On the other hand, in the structure of the semiconductor laser 200 shown in FIG. 4 and FIG. 5, the layer beside the light emitting region 203 including the active layer can be an i-InP layer instead of a p-InP layer. Therefore, a low threshold current can be expected.

  When the impurity concentration in the current leak layer 208 is zero, an i-InP layer is inserted between the first conductivity type current block layer 207 and the second conductivity type current block layer 206. The structure of the semiconductor laser 200 is a pin structure. As a result, the capacity of the semiconductor laser 200 can be reduced, and the structure can be made superior to the conventional structure in terms of high-speed driving.

(Method for manufacturing semiconductor lasers 100 and 200)
The structure and operational effects of the semiconductor lasers 100 and 200 of this embodiment have been described above. Next, a method for manufacturing the semiconductor lasers 100 and 200 according to the present embodiment will be described with reference to FIGS. 6 and 7 are process sectional views in the manufacturing process of the semiconductor lasers 100 and 200. FIG.

First, as shown in FIG. 6 (A), the Si-doped n-type InP substrate 101 of an impurity concentration 1 × 10 ¹⁸ cm ^-3, the impurity concentration 1 × 10 ¹⁸ cm ^-3, Si doped n-type thickness 1500nm An InP cladding layer 102 (seventh III-V compound semiconductor layer) is grown. Thereafter, an InGaAsP-SCH layer 103a having a thickness of 50 nm and a composition λ = 1.20 μm, an InGaAsP-MQW active layer 103b (first III-V compound semiconductor layer) having a barrier composition λ = 1.10 μm, an n having a thickness of 50 nm and a composition λ = 1.20 μm After the growth of the type InGaAsP-SCH layer 103c, the first region 104a of the Zi-doped p-type InP cladding layer 104 having an impurity concentration of 1 × 10 ¹⁸ cm ⁻³ and a thickness of 400 nm is grown. The InGaAsP-SCH layer 103a, the InGaAsP-MQW active layer 103b, and the InGaAsP-SCH layer 103c form a light emitting region 103.

  Next, as shown in FIG. 6B, dry etching is performed up to the substrate 101 to form a semiconductor mesa 105. Next, although not shown in the drawing, a damaged layer by dry etching up to the substrate 101 is removed by about 0.1 μm by wet etching. Next, as shown in FIG. 6C, a semiconductor mesa 105 is embedded with a p-type InP current blocking layer 106 (second III-V compound semiconductor layer). Next, as shown in FIG. 6D, etching is performed using a chlorine-based gas, and only the side surfaces of the semiconductor mesa 105 are etched. By using an anisotropic etching gas such as a chlorine-based gas, only the p-type InP current blocking layer beside the semiconductor mesa 105 is removed from the p-type InP current blocking layer shown in FIG. 6C. be able to.

Next, as shown in FIG. 7A, a p-type InP current leakage layer 108 (third III-V compound semiconductor layer) having a thickness of 0.2 μm or less is grown. Next, as shown in FIG. 7B, a semiconductor mesa 105 is embedded on the p-type InP current leakage layer 108 with an n-type InP current blocking layer 107 (fourth III-V compound semiconductor layer), and further on it. A second region 104b of the p-type InP cladding layer 104 (fifth III-V compound semiconductor layer) having an impurity concentration of 1 × 10 ¹⁸ cm ⁻³ and a thickness of 500 nm is grown. Next, a Zi-doped n-type InGaAs contact layer 109 (sixth III-V compound semiconductor layer) having an impurity concentration of 1 × 10 ¹⁹ cm ⁻³ and a thickness of 200 nm is formed on the second region 104b of the p-type InP cladding layer 104. grow up. Finally, as shown in FIG. 7C, after forming the SiO 2 insulating film 110, a window is opened only in the upper part of the active layer 103b, and a p-type upper electrode 111 and an n-type back electrode 112 are formed. Thus, the semiconductor laser 100 is completed.

  In FIG. 6C, the growth of the p-type InP current blocking layer 106 is controlled so as to stop at the portion between the active layer 103b and the n-type InP cladding layer 102, as shown in FIG. The semiconductor laser 200 can be manufactured. In the semiconductor laser 200 of FIG. 4, the p-type InP current blocking layer 206 is reliably positioned between the n-type InP current blocking layer 207 and the n-type InP cladding layer 202. Thus, even if the p-type InP current leakage layer 208 is thin or has a low impurity concentration, current leakage from the n-type InP current blocking layer 207 to the n-type InP cladding layer 202 (current leakage by the leakage path C in FIG. 3). ) Can be prevented. As a result, the concentration of the p-type InP current leakage layer 208 can be reduced, the current leakage can be reduced, the breakdown voltage of the pnpn thyristor can be increased, and the diffusion of the p-type dopant such as Zn into the active layer can be prevented. Etc. can be prevented. Further, since the current block portion can have a pin structure, the capacity can be further reduced, and a semiconductor laser suitable for high-speed driving can be obtained.

1 is a perspective view showing a semiconductor laser 100 according to the present embodiment. It is sectional drawing which shows the semiconductor laser 100 which concerns on this embodiment. FIG. 3 is a diagram illustrating a leakage current path in the semiconductor laser 100 of FIG. 2. It is sectional drawing which shows the semiconductor laser 200 which concerns on this embodiment. It is sectional drawing which shows the semiconductor laser 200 which concerns on this embodiment. It is process sectional drawing in the manufacture process of the semiconductor laser 100 of this embodiment. It is process sectional drawing in the manufacture process of the semiconductor laser 100 of this embodiment. It is sectional drawing which shows the conventional BH laser.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Semiconductor laser, 101 ... Board | substrate, 102 ... 1st conductivity type clad layer, 103 ... Light emission area | region, 103b ... Active layer, 104 ... 2nd conductivity type clad layer, 105 ... Semiconductor mesa, 106 ... 2nd conductivity type current block Layer 107 107 first conductivity type current blocking layer 108 current leak layer 109 contact layer 110 insulating film 111 112 electrode 200 semiconductor laser 201 substrate 202 202 first clad Layer 203, light-emitting region, 205 ... semiconductor mesa, 206 ... second conductivity type current blocking layer, 207 ... first conductivity type current blocking layer, 208 ... current leakage layer.

Claims (7)

A semiconductor mesa provided on the substrate and including an active layer;
A second conductivity type current blocking layer provided on the substrate and embedding the semiconductor mesa;
A first conductivity type current blocking layer which is provided on the second conductivity type current blocking layer and embeds the semiconductor mesa;
A second conductivity type cladding layer provided on the active layer and on the first conductivity type current blocking layer;
A contact layer provided on the second conductivity type cladding layer;
A semiconductor laser comprising:
A second conductive type semiconductor layer having a thickness of 0.2 μm or less between the first conductive type current blocking layer and the semiconductor mesa and between the first conductive type current blocking layer and the second conductive type current blocking layer. A semiconductor laser comprising a current leakage layer comprising: 2. The semiconductor laser according to claim 1, wherein an impurity concentration in the current leak layer is 1 × 10 ¹⁷ cm ⁻³ or less. In the semiconductor mesa, a first conductivity type cladding layer is further formed under the active layer,
The height of the upper surface of the second conductivity type current blocking layer from the substrate is equal to or higher than the height of the upper surface of the first conductivity type cladding layer from the substrate. The semiconductor laser described. A first III-V compound semiconductor layer for an active layer is grown on the substrate by metal organic vapor phase epitaxy, and dry etching is performed using a striped mask formed on the first III-V compound semiconductor layer. Performing a first step of forming a semiconductor mesa;
A second step of growing a second III-V compound semiconductor layer for a second conductivity type current blocking layer embedding the semiconductor mesa on the substrate and on the side of the semiconductor mesa by metal organic chemical vapor deposition;
A third step of etching away the second III-V compound semiconductor layer grown beside the semiconductor mesa in the second step;
A third III-V compound semiconductor layer for a second conductivity type current leakage layer having a thickness of 0.2 μm or less is formed on the second III-V compound semiconductor layer and on the side of the semiconductor mesa exposed by the third step. A fourth step of growing by vapor phase growth;
A fifth step of growing a fourth III-V compound semiconductor layer for the first conductivity type current blocking layer by metal organic vapor phase epitaxy in contact with the third III-V compound semiconductor layer;
After removing the mask, a fifth III-V compound semiconductor layer for a second conductivity type cladding layer is grown on the active layer and the fourth III-V compound semiconductor layer by metal organic vapor phase epitaxy. And a sixth step to
A seventh step of growing a sixth III-V compound semiconductor layer for a second conductivity type contact layer on the fifth III-V compound semiconductor layer by metal organic chemical vapor deposition;
A method of manufacturing a semiconductor laser, comprising: The third III-V compound semiconductor layer is grown in the fourth step so that an impurity concentration of the third III-V compound semiconductor layer is 1 × 10 ¹⁷ cm ⁻³ or less. 5. A method for producing a semiconductor laser according to 4. In the first step, before the first III-V compound semiconductor layer is grown, a seventh III-V compound semiconductor layer for the first conductivity type cladding layer is grown by metal organic vapor phase epitaxy,
In the second step, the height of the upper surface of the second III-V compound semiconductor layer from the substrate is equal to or higher than the height of the upper surface of the seventh III-V compound semiconductor layer from the substrate. 6. The method of manufacturing a semiconductor laser according to claim 4, wherein a 2III-V compound semiconductor layer is grown. The semiconductor laser manufacturing method according to claim 4, wherein the etching is performed using a chlorine-based gas in the third step.

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