JP3645664B2 - Semiconductor laser manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor laser, and more particularly to a method for manufacturing a semiconductor laser with little light absorption at an end portion of an element.
[0002]
[Prior art]
Currently, semiconductor lasers are incorporated into various devices such as laser printers, laser gyroscopes, and laser Doppler velocimeters. It is also widely used for laser isotope separation in which uranium is concentrated using laser light and laser-induced chemical reaction in which molecules are excited by laser light to cause a chemical reaction.
[0003]
In order to increase the reliability and output of these devices, it is necessary to increase the output and reliability of the semiconductor laser that is the light source.
[0004]
In general, a semiconductor laser emits a laser beam by passing a current through a p-type cladding layer, an active layer formed on the p-type cladding layer, and an n-type cladding layer formed on the active layer. Is generated. In such a semiconductor laser, it is generally known that the forbidden band width (band gap) is small at the end face of the active layer, that is, the face from which light is emitted. First of all, this is because surface recombination is likely to occur because lattice defects and the like are likely to occur on the end face. Secondly, impurities adhere to the end face, and oxygen molecules in the air enter the end face to form gallium oxide or the like that reduces the forbidden band width.
[0005]
Here, when the forbidden band width of the end face is reduced, laser light generated inside the active layer is easily absorbed by the end face. Therefore, there exists a problem that the output of a semiconductor laser becomes small. Further, when the light generated inside the active layer is absorbed by the end face, the temperature of the end face rises, and in the worst case, the end face is melted, thereby reducing the reliability of the semiconductor laser.
[0006]
Therefore, in order to increase the output and reliability of the semiconductor laser, it is necessary to prevent such light absorption at the end face.
[0007]
Here, a semiconductor laser described in Japanese Patent Application Laid-Open No. 64-81387 is known as a semiconductor laser with little light absorption at the end face.
[0008]
FIG. 9 is a schematic perspective view showing a conventional semiconductor laser as described in the above publication. Referring to FIG. 9, a semiconductor laser 101 includes electrodes 102 and 109, an n-type substrate 103, an n-type cladding layer 104, an active layer 105, a p-type cladding layer 106, an n-type block layer 107, A p-type contact layer 108 and passivation films 110 and 111 are provided.
[0009]
An electrode 102 is formed in contact with the n-type substrate 103. An n-type cladding layer 104 is formed on and in contact with the n-type substrate 103. An active layer 105 is formed on the n-type cladding layer 104 so as to be in contact therewith. A p-type cladding layer 106 is formed on and in contact with the active layer 105. An n-type block layer 107 is formed on and in contact with the p-type cladding layer 106. The p-type contact layer 108 is formed in contact with the n-type block layer 107. The p-type contact layer 108 is formed in contact with the p-type cladding layer 106 at the center thereof. The electrode 109 is formed in contact with the p-type contact layer 108.
[0010]
A stripe-like light emitting region 114 for generating light is formed at the center of the n-type cladding layer 104, the active layer 105, and the p-type cladding layer 106. The stripe-shaped light emitting region 114 is located below the surface where the p-type contact layer 108 and the p-type cladding layer 106 are in contact, and extends in the upper right direction in the drawing.
[0011]
Light is emitted from a portion (a portion surrounded by a dotted line in the drawing) which is an end face of the stripe-shaped light emitting region 114 in the emission surface 112. A passivation film 110 is formed so as to cover the emission surface 112. Further, a passivation film 111 is formed so as to cover the rear cross section 113. In the active layer 105, the forbidden band width increases as it approaches the emission surface 112.
[0012]
Next, a method for manufacturing the conventional semiconductor laser shown in FIG. 9 will be described. FIG. 10 is a schematic perspective view showing a manufacturing method of the semiconductor laser shown in FIG. Referring to FIG. 10, an n-type cladding layer 104 is formed on an n-type substrate 103 by a molecular beam epitaxial method or the like. Next, an active layer 105 is grown on the n-type cladding layer 104, and a p-type cladding layer 106 is grown on the active layer 105 in succession by a molecular beam epitaxial method or the like.
[0013]
Next, an n-type material is formed on the p-type cladding layer 106, and an n-type block layer 107 is formed by etching the central portion of the n-type material in a stripe shape. At this time, the p-type cladding layer 106 is exposed in a stripe shape. Next, the p-type contact layer 108 is formed in contact with the p-type cladding layer 106 and the n-type block layer 107 by a molecular beam epitaxial method or the like.
[0014]
Next, the electrodes 102 and 109 are formed by vapor deposition. Next, the device is cut out from the wafer by element by a cleavage method, and the cleavage surface is defined as an emission surface 112 and a rear end surface 113. Of the portions of the p-type cladding layer 106, the active layer 105, and the n-type cladding layer 104, the portion located below the surface where the p-type contact layer 108 and the p-type cladding layer 106 are in contact with each other is striped. A light emitting region 114 is formed.
[0015]
Next, the active layer 105, the n-type cladding layer 104, and the p-type cladding layer 106 are mixed by irradiating a laser beam to the stripe-shaped light emitting region 114 and its peripheral portion in the emission surface 112. By such laser light irradiation, aluminum in the n-type cladding layer 104 and the p-type cladding layer 106 enters the active layer 105. Therefore, the forbidden band width is increased in the vicinity of the end face of the active layer 105, that is, in the vicinity of the end face of the stripe-shaped light emitting region 114.
[0016]
Referring to FIG. 9, passivation films 111 and 110 are formed on rear end face 113 and emission face 112 irradiated with laser light. In this way, the semiconductor laser 101 is completed.
[0017]
In the semiconductor laser manufactured as described above, the aluminum atoms in the n-type cladding layer 104 and the p-type cladding layer 106 are mixed into the active layer 105 as shown in FIG. It is possible to increase the forbidden bandwidth and prevent light absorption at the end face. Therefore, the output of the semiconductor laser can be improved, and further the reliability can be improved.
[0018]
[Problems to be solved by the invention]
However, the conventional semiconductor laser shown in FIG. 9 has the following problems.
[0019]
First of all, there is another countermeasure for reducing the forbidden band width due to another cause of reducing the forbidden band width of the active layer, that is, oxygen atoms entering the end face or impurities adhering to the end face. Have not taken. Therefore, the semiconductor laser shown in FIG. 10 has a problem that the forbidden band width at the end face cannot be sufficiently widened.
[0020]
Furthermore, in the conventional semiconductor laser, as is apparent from FIG. 10, the aluminum atoms mixed into the active layer 105 are included in the n-type cladding layer 104 and the p-type cladding layer 106. Here, since the aluminum contained in the n-type cladding layer 104 and the p-type cladding layer 106 is in a very small amount, the aluminum cannot be sufficiently supplied to the active layer 105, so that the forbidden band width of the active layer 105 is sufficiently large. There is a problem that it cannot be spread.
[0021]
Accordingly, the present invention has been made to solve the above-described problems, and removes oxygen and impurities from the end face of the semiconductor laser and supplies sufficient aluminum to the active layer to forbid the active layer. An object of the present invention is to provide a method of manufacturing a semiconductor laser capable of widening the width.
[0040]
[Means for Solving the Problems]
A method of manufacturing a semiconductor laser in accordance with the inventions is provided with a more or less of Engineering.
[0041]
(1) A group III-V compound semiconductor containing a first element selected from group III of the periodic table and a second element selected from group V of the periodic table, the first surface and its first surface Preparing a first conductivity type substrate having a second surface opposite to the first surface.
[0042]
(2) A step of forming a first electrode layer on the second surface of the substrate.
(3) A clad layer of the first conductivity type including a first element, a second element, and a third element selected from group III and different from the first element is formed on the first surface of the substrate. Forming step.
[0043]
(4) A step of forming an active layer containing a first element, a second element, and a third element on the cladding layer of the first conductivity type.
[0044]
(5) A step of forming a second conductivity type cladding layer containing a first element, a second element, and a third element on the active layer.
[0045]
(6) A step of forming a second conductivity type contact layer made of a III-V group compound semiconductor containing the first element and the second element on the second conductivity type cladding layer.
[0046]
(7) A step of forming a second electrode layer on the contact layer.
(8) A step of forming a film made of the third element on the emission surface made of the end face of the active layer.
[0047]
(9) A step of increasing the forbidden band width of the active layer by melting the film made of the third element and mixing the third element into the active layer.
[0048]
Here, in the step of increasing the forbidden band width of the active layer, it is preferable to melt the film made of the third element by irradiating the film made of the third element with a laser beam.
[0049]
In the step of increasing the forbidden band width of the active layer, a current is passed through the active layer to generate a laser beam from the active layer, and the third layer is irradiated with the laser beam to the film made of the third element. It is preferable to include melting a film made of the above element.
[0050]
Furthermore, it is preferable that the first element is gallium, the second element is arsenic, and the third element is aluminum.
[0051]
In the method of manufacturing a semiconductor laser including such a process, in the process indicated by (9), the film made of the third element is melted, and the third element is mixed into the active layer to end the end face of the active layer. Increase the forbidden bandwidth. For this reason, since the third element is contained in the film made of the third element in a larger amount than in the clad layer, the third element is larger than in the case where the third element in the clad layer is mixed into the active layer. Can be mixed in the active layer. Therefore, the forbidden band width of the end face of the active layer can be sufficiently increased. Therefore, light is not absorbed at the end face of the active layer. As a result, the output of the semiconductor laser can be increased, heat generation at the end face can be prevented, and reliability can be improved.
[0052]
In addition, if the film made of the third element is melted by irradiating the film made of the third element with a laser beam and the third element is mixed into the active layer, the third element is reliably activated. It can be mixed in the layer.
[0053]
In addition, when a current is passed through the active layer to generate a laser beam from the active layer and the film made of the third element is irradiated with the laser beam to melt the film made of the third element, the third element is It can be reliably mixed into the active layer.
[0054]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
1 is a schematic perspective view showing a semiconductor laser according to Embodiment 1 of the present invention. Referring to FIG. 1, a semiconductor laser 1 includes an n-type substrate 3, an n-type cladding layer 4, an active layer 5, a p-type cladding layer 6, an n-type block layer 7, and a p-type contact layer 8. Electrodes 2 and 9 and passivation films 10 and 11 are provided.
[0055]
An n-type cladding layer 4 is formed on the upper surface 18 of the n-type substrate 3. The electrode 2 is in contact with the lower surface 19 of the substrate 3. The material of the n-type substrate 3 is a GaAs compound semiconductor. The material of the electrode 2 is AuGe / Ni. The material of the n-type cladding layer 4 is an AlGaAs compound. An active layer 5 is formed on the n-type cladding layer 4 so as to be in contact therewith. The material of the active layer 5 is an AlGaAs compound. A p-type cladding layer 6 is formed on the active layer 5 so as to be in contact therewith. The material of the p-type cladding layer 6 is an AlGaAs compound. An n-type block layer 7 is formed on the p-type cladding layer 6 so as to be in contact therewith. The material of the n-type block layer 7 is a GaAs compound. A groove is formed in the central portion of the n-type block layer 7. A p-type contact layer 8 is formed in contact with both the n-type block layer 7 and the p-type cladding layer 6. The material of the p-type contact layer 8 is a GaAs compound semiconductor.
[0056]
An electrode 9 is formed on the p-type contact layer 8 so as to be in contact therewith. The material of the electrode 9 is Au / AuZn. The proportion of Al in the active layer 5 is smaller than the proportion of Al in the n-type cladding layer 4 and the p-type cladding layer 6. Further, laser light is generated from the striped light emitting region 14 surrounded by a dotted line in the drawing. The stripe-shaped light emitting region 14 is constituted by the n-type cladding layer 4, the active layer 5, and the p-type cladding layer 6, and is formed below the surface where the p-type cladding layer 6 and the p-type contact layer 8 are in contact.
[0057]
A passivation film 10 is formed on the emission surface 12. The passivation film 10 is a multilayer film composed of a Si film and a SiO ₂ film. The passivation film 10 is almost transparent. The passivation film 11 is in contact with the rear end face 13. The passivation film 11 also has a multilayer structure of SiO ₂ film and Si film, but is thicker than the passivation film 10.
[0058]
Next, a method for manufacturing the semiconductor laser shown in FIG. 1 will be described.
FIG. 2 is a schematic perspective view showing a first step of the method of manufacturing the semiconductor laser shown in FIG. Referring to FIG. 2, an n-type cladding layer 4 made of an AlGaAs compound and having a thickness of about 0.7 μm is grown on an upper surface 18 of an n-type substrate 3 made of a GaAs compound semiconductor by a MOCVD (Metal Organic Chemical Vapor Deposition) method.
[0059]
Next, an active layer 5 made of an AlGaAs compound and having a thickness of about 0.7 μm is formed on the n-type cladding layer 4 by MOCVD. A p-type cladding layer 6 made of an AlGaAs compound and having a thickness of about 0.7 μm is formed on the active layer 5 by MOCVD. Here, the proportion of Al in the active layer 5 is smaller than the proportion of Al in the n-type cladding layer 4 and the p-type cladding layer 6.
[0060]
A GaAs compound is formed with a thickness of about 0.6 μm on the p-type cladding layer 6, and the GaAs compound is selectively etched to selectively expose the surface of the p-type cladding layer 6. Thereby, the n-type block layer 7 is formed. The depth of the groove is about 0.7 μm. A p-type contact layer 8 made of a GaAs compound semiconductor is formed by MOCVD so as to be in contact with the p-type cladding layer 6 and the n-type block layer 7. The lower surface 19 of the substrate 3 is polished.
[0061]
Next, the electrode 2 made of AuGe / Ni is formed on the lower surface 19 of the substrate 3 by vapor deposition. An electrode 9 made of Au / AuZn is formed on the p-type contact layer 8 by vapor deposition.
[0062]
Next, the emission surface 12 and the rear end surface 13 are formed by cleavage. The distance between the emission surface 12 and the rear end surface 13 is about 300 μm.
[0063]
Referring to FIG. 3, Ar laser indicated by arrow 15 is applied to emission surface 12 and rear end surface 13 in a vacuum or in a hydrogen atmosphere, and the temperature of emission surface 12 and rear end surface 13 is set to 200 to 300 ° C. Thereby, impurities and oxides adhering to the emission surface 12 and the rear end surface 13 are volatilized.
[0064]
Referring to FIG. 1, a passivation film 10 is formed by laminating a Si film and a SiO ₂ film on the emission surface 12 irradiated with the laser beam by a CVD method. Next, a Si film and a SiO ₂ film are stacked on the rear end face 13 to form a passivation film 11. The thickness of the passivation film 10 is about 0.4 μm, and the reflectance is 3%. The thickness of the passivation film 11 is 0.8 μm, and the reflectance is 90%.
[0065]
In the semiconductor laser manufacturing method of the present invention configured as described above, in the step shown in FIG. 3, the emission surface 12 and the rear end surface 13 are irradiated with the Ar laser indicated by the arrow 15 on the emission surface 12 and the rear end surface 13. Impurities and oxides deposited on the substrate volatilize. For this reason, there is no decrease in the forbidden band width due to impurities or oxides, which was not taken into account in the prior art, and the forbidden band width is not reduced at the end face of the semiconductor laser. Therefore, light is not absorbed at the end face of the active layer. As a result, the output of the semiconductor laser can be increased, heat generation at the end face can be prevented, and reliability can be improved.
[0066]
(Embodiment 2)
FIG. 4 is a schematic perspective view showing a semiconductor laser according to the second embodiment of the present invention. Referring to FIG. 4, a semiconductor laser 21 includes electrodes 22, 29, an n-type substrate 23, an n-type cladding layer 24, an active layer 25, a p-type cladding layer 26, an n-type block layer 27, A p-type contact layer 28, passivation films 30 and 31, and an aluminum film 36 are provided.
[0067]
The semiconductor laser 21 shown in FIG. 4 has substantially the same structure as the semiconductor laser 1 shown in FIG. Therefore, the electrode 22, the n-type substrate 23, the n-type clad layer 24, the active layer 25, the p-type clad layer 26, the n-type block layer 27, the p-type contact layer 28, the electrode 29, and the passivation films 30, 31 in FIG. The emission surface 32, the rear end surface 33, the stripe-shaped light emitting region 34, the upper surface 38, and the lower surface 39 are the same as those having the same names in FIG.
[0068]
The only difference between the semiconductor laser 21 shown in FIG. 4 and the semiconductor laser 1 shown in FIG. 1 is that, in the semiconductor laser 21 shown in FIG. 4, between the emission surface 32 and the passivation film 30 and the rear end face 33 and the passivation film 31. The aluminum film 36 is formed between the two.
[0069]
Next, a method for manufacturing the semiconductor laser shown in FIG. 4 will be described. FIG. 5 is a schematic perspective view showing a manufacturing method of the semiconductor laser shown in FIG. Referring to FIG. 5, as in FIG. 2 in the first embodiment, n-type substrate 23, n-type cladding layer 24, active layer 25, p-type cladding layer 26, n-type block layer 27, and p-type contact layer 28, electrodes 9 and 2 are formed. Next, an aluminum film 36 is formed with a thickness of about 7 nm on the emission surface 32 and the rear end surface 33 by sputtering. By this aluminum film 36, oxygen atoms forming gallium oxide or the like on the emission surface 32 and the rear end face 33 are taken into the aluminum film 36 and become alumina.
[0070]
Referring to FIG. 4, passivation films 30 and 31 are formed on emission surface 32 and rear end surface 33 on which aluminum film 36 is formed. The semiconductor laser 21 is completed as described above.
[0071]
In the semiconductor laser manufacturing method configured as described above, in the step shown in FIG. 5, gallium oxide or the like is formed on the emission surface 32 and the rear end surface 33 in order to form the aluminum film 36 on the emission surface 32 and the rear end surface 33. The formed oxygen atoms can be taken into the aluminum film 36 as alumina. Since alumina is a stable substance, oxygen atoms in alumina do not bond with gallium or the like. Therefore, it is possible to suppress a decrease in the forbidden bandwidth due to oxides that have not been considered in the past. Therefore, the forbidden band width is not reduced at the end face of the active layer, and light absorption at the end face can be prevented. Accordingly, it is possible to increase the laser output, further prevent heat generation at the end face, and improve the reliability of the semiconductor laser.
[0072]
(Embodiment 3)
FIG. 6 is a schematic perspective view showing a semiconductor laser according to the third embodiment of the present invention. Referring to FIG. 6, a semiconductor laser 41 includes electrodes 42 and 49, an n-type substrate 43, an n-type clad layer 44, an active layer 45, a p-type clad layer 46, an n-type block layer 47, A p-type contact layer 48 and passivation films 50 and 51 are provided.
[0073]
The semiconductor laser 41 shown in FIG. 6 has substantially the same configuration as the semiconductor laser 21 shown in FIG. Therefore, the electrode 42, the n-type substrate 43, the n-type cladding layer 44, the active layer 45, the p-type cladding layer 46, the n-type block layer 47, the p-type contact layer 48, the electrode 49, and the passivation films 50 and 51 in FIG. The emission surface 52, the rear end surface 53, the stripe-like light emitting region 54, the aluminum film 56, the upper surface 58, and the lower surface 59 are the same as those having the same names in FIG.
[0074]
The only difference between the semiconductor laser 41 shown in FIG. 6 and the semiconductor laser 21 shown in FIG. 4 is that the semiconductor laser 41 shown in FIG. 6 has a forbidden band width at the emission surface 52 and the rear end face 53 of the active layer 45. 4 is larger than the forbidden band width of the active layer 25 shown in FIG.
[0075]
Next, a method for manufacturing the semiconductor laser shown in FIG. 6 will be described. 7 and 8 are schematic perspective views showing a method of manufacturing the semiconductor laser shown in FIG. Referring to FIGS. 7 and 8, as shown in FIG. 2 of the first embodiment, n-type substrate 43, n-type cladding layer 44, active layer 45, p-type cladding layer 46, n-type block layer 47, p A mold contact layer 48, electrodes 42 and 49, an emission surface 52, and a rear end surface 53 are formed. Next, an aluminum film 56 having a thickness of about 7 nm is formed on the emission surface 52 and the rear end surface 53 by a sputtering method. Next, by irradiating the emission surface 52 and the rear end surface 53 with Ar laser light indicated by an arrow 55, the aluminum film 56, the emission surface 52, and the rear end surface 53 are set to 1000 ° C. or higher, and the aluminum in the aluminum film is made into the active layer 45. (FIG. 7). Further, a voltage more than 10 times that during normal laser oscillation is applied between the electrodes 42 and 49 to generate a high-power laser beam 75, and the aluminum film 56 is irradiated with the laser beam 75. The emission surface 52 and the rear end surface 53 may be at a high temperature of 1000 ° C. or higher (FIG. 8). Thereby, aluminum in the aluminum film 56 is mixed into the active layer 45. Therefore, the forbidden band width of the active layer 45 increases near the emission surface 52 and the rear end surface 53.
[0076]
Referring to FIG. 6, passivation films 50 and 51 similar to passivation film 10 in the first embodiment are formed by a CVD method. In this way, the semiconductor laser 41 is completed.
[0077]
In the semiconductor laser manufacturing method configured as described above, the aluminum film 56 is melted and aluminum in the aluminum film 56 is mixed into the active layer 45 in the steps shown in FIGS. Therefore, compared with the case where the aluminum in the n-type cladding layer 44 and the p-type cladding layer 46 is mixed into the active layer 45, a larger amount of aluminum can be mixed into the active layer, and at the emission surface 52 and the rear end surface 53, The forbidden bandwidth can be further increased.
[0078]
Further, since the aluminum film 56 is formed on the emission surface 52 and the rear end surface 53, oxygen atoms forming gallium oxide or the like on the emission surface 52 and the rear end surface 53 can be taken into the aluminum film 56 as alumina. The forbidden band width at the surface 52 and the rear end surface 53 can be further increased.
[0079]
Therefore, light is not absorbed at the end face of the active layer. As a result, the output of the semiconductor laser can be increased, heat generation at the end face can be prevented, and reliability can be improved.
[0080]
Although the present invention has been described above, various modifications can be made to the embodiment shown here. That is, any laser such as an Ar laser, a He—Ne laser, or a carbon dioxide laser may be used for irradiating the emission surface and the rear end surface of the semiconductor laser. Further, the method of growing the p-type cladding layer or the like is not limited to the MOCVD method, but may be a molecular beam epitaxial method, a liquid phase epitaxial method, or the like. Further, although a GaAs compound semiconductor is shown as the n-type substrate, it can be replaced with a known material such as InGaAsP.
[0081]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0082]
【The invention's effect】
According to this invention, it is possible to remove oxides and impurities adhering to the emission surface of the semiconductor laser, and to improve the output reliability of the semiconductor laser.
[0083]
Furthermore, according to the present invention, the forbidden band width at the end face of the active layer of the semiconductor laser can be increased, and the output and reliability of the semiconductor laser can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a semiconductor laser according to a first embodiment of the present invention.
FIG. 2 is a schematic perspective view showing a first step of the method of manufacturing the semiconductor laser shown in FIG.
FIG. 3 is a schematic perspective view showing a second step of the method of manufacturing the semiconductor laser shown in FIG.
FIG. 4 is a schematic perspective view showing a semiconductor laser according to a second embodiment of the present invention.
5 is a schematic perspective view showing a method for manufacturing the semiconductor laser shown in FIG. 4. FIG.
FIG. 6 is a schematic perspective view showing a semiconductor laser according to a third embodiment of the present invention.
7 is a schematic perspective view showing a method for manufacturing the semiconductor laser shown in FIG. 6. FIG.
8 is a schematic perspective view showing another method for manufacturing the semiconductor laser shown in FIG. 6. FIG.
FIG. 9 is a schematic perspective view showing a conventional semiconductor laser.
10 is a schematic perspective view showing a method for manufacturing the semiconductor laser shown in FIG. 9. FIG.
[Explanation of symbols]
1, 21, 41 Semiconductor laser, 2, 9, 22, 29, 42, 49 electrode, 3, 23, 43 n-type substrate, 4, 24, 44 n-type cladding layer, 5, 25, 45 active layer, 6, 26, 46 p-type cladding layer, 8, 28, 48 p-type contact layer, 10, 30, 50 passivation film, 12, 32, 52 emitting surface, 15, 55, 75 laser light, 18, 38, 58 upper surface, 19 , 39, 59 Lower surface, 36, 56 Aluminum film.

Claims (4)

It consists of a III-V group compound semiconductor containing the 1st element chosen from periodic table group III and the 2nd element chosen from periodic table group V, and the 1st side and the 1st side Preparing a first conductivity type substrate having a second surface facing each other;
Forming a first electrode layer on a second surface of the substrate;
A first conductivity type cladding layer including the first element, the second element, and a third element selected from the group III and different from the first element is formed on the substrate. Forming on the surface;
Forming an active layer containing the first element, the second element, and the third element on the cladding layer of the first conductivity type;
Forming a second conductivity type clad layer containing the first element, the second element and the third element on the active layer;
Forming a second conductivity type contact layer made of a III-V compound semiconductor containing the first element and the second element on the second conductivity type cladding layer;
Forming a second electrode layer on the contact layer;
Forming a film made of the third element on an emission surface made of an end face of the active layer;
A method of manufacturing a semiconductor laser, comprising: melting a film made of the third element to mix the third element into the active layer to increase a forbidden band width of the active layer. The step of increasing the bandgap of the active layer, by irradiating a laser beam to the film made of the third element involves melting the film made of the third element, according to claim 1 Semiconductor laser manufacturing method. The step of enlarging the forbidden band width of the active layer includes generating a laser beam from the active layer by passing a current through the active layer, and irradiating the film made of the third element with the laser beam. The method for manufacturing a semiconductor laser according to claim 1 , comprising melting the film made of the third element. The first element is gallium, the second element is arsenic, the third element is aluminum, a manufacturing method of a semiconductor laser according to any one of claims 1 to 3.

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