JP2008288256A - Method of manufacturing semiconductor laser element and semiconductor laser device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor laser element that can give distortion by a simplified step and relax thermal stress without degrading the efficiency of exhaust heat. <P>SOLUTION: A distortion-addition member 11 of which coefficient of linear expansion is smaller than that of a semiconductor laser bar 10 is bonded to the n side of the semiconductor laser bar 10 with a bonding layer 10a in between. A heat sink 12 is bonded to the p side of the semiconductor laser bar 10 with a bonding layer 10b in between. For example, an eutectic solder containing tin is used to a bonding part 10a and a solder containing indium is used to a bonding part 10b. The distortion-addition member 11 is bonded to the n side with the bonding layer 10a in between, so that distortion due to expansion stress is given to the semiconductor laser bar 10. Thus, thermal conduction to the heat sink 12 is hardly blocked on the p side. The indium-containing solder is used to the bonding layer 10b, so that stress is difficult to be transmitted to the semiconductor laser bar 10 from the heat sink 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing method for bonding a semiconductor laser element on a heat radiating member such as a heat sink and a semiconductor laser device manufactured thereby.

  2. Description of the Related Art Conventionally, in application equipment in which a semiconductor laser is used, a technique of mounting the semiconductor laser on a heat radiating member such as a heat sink is used to discharge heat generated in the semiconductor laser. However, since the difference in coefficient of linear expansion is generally large between a semiconductor laser and a heat sink, a large thermal stress (compressive stress) is applied from the heat sink to the semiconductor laser due to a temperature change. For this reason, characteristics such as light emission efficiency and lifetime are deteriorated particularly during high temperature operation, and the laser itself may not oscillate.

Therefore, a technique for interposing a member (such as a submount) for relaxing the thermal stress from the heat sink to the semiconductor laser between the semiconductor laser and the heat sink (for example, Patent Documents 1 to 3), or bending the semiconductor laser. For example, a technique (for example, Patent Document 4) has been proposed in which a compressive stress from the heat sink during mounting or high-temperature operation is canceled by applying tensile stress to the joint surface with the heat sink in advance. .
JP 2003-198027 A JP 2002-57401 A Japanese Patent No. 3788343 Japanese Patent Laid-Open No. 10-247763

  However, since the submount provided for stress relaxation as described above is generally made of a material having lower thermal conductivity than the heat sink, there is a problem in that the efficiency of exhaust heat from the semiconductor laser to the heat sink decreases. It was. Therefore, it has been desired to realize a semiconductor laser that can alleviate the thermal stress from the heat sink without reducing the exhaust heat efficiency of the semiconductor laser.

  On the other hand, in order to improve the laser characteristics such as the light emission efficiency, the semiconductor layer is grown on the substrate so as to be lattice-mismatched with the substrate in the manufacturing process of the semiconductor laser. A technique for applying a predetermined strain (lattice strain) is used.

  However, as described above, when strain is applied at the crystal growth stage of the semiconductor layer, it is necessary to form a film while adjusting the material ratio of the semiconductor layer, the film formation time, etc., depending on the desired amount of strain, There was a problem that the process was complicated.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a semiconductor laser capable of adding distortion by a simple process and relaxing thermal stress without reducing exhaust heat efficiency. An object of the present invention is to provide a device manufacturing method and a semiconductor laser device.

  According to a method of manufacturing a semiconductor laser device of the present invention, a strain-adding member having a linear expansion coefficient different from that of a semiconductor laser element is formed on one surface of a semiconductor laser element having a pair of opposed surfaces via a first bonding layer. A step of bonding, and a step of bonding the heat radiating member to the other surface of the semiconductor laser element via a second bonding layer made of a material having a hardness lower than that of the first bonding layer.

  In the method of manufacturing a semiconductor laser device of the present invention, a strain applying member having a linear expansion coefficient different from that of the semiconductor laser element is bonded to one surface of the semiconductor laser element through the first bonding layer. Therefore, a compressive or tensile stress is applied to the semiconductor laser element due to a difference in linear expansion coefficient. At this time, since the hardness of the first bonding layer is relatively high, stress is easily transmitted from the strain applying member to the semiconductor laser element. On the other hand, by joining the heat radiating member to the other surface of the semiconductor laser element via the second bonding layer, the heat generated in the semiconductor laser reaches the heat radiating member without going through the strain applying member. At this time, since the hardness of the second bonding layer is relatively low, thermal stress is hardly transmitted from the heat dissipation member to the semiconductor laser element.

  The semiconductor laser device of the present invention is bonded to one surface of a semiconductor laser element having a pair of opposing surfaces via a first bonding layer, and has a linear expansion coefficient. And a heat-dissipating member bonded to the other surface of the semiconductor laser element via a second bonding layer made of a material having a hardness lower than that of the first bonding layer. is there.

  According to the method for manufacturing a semiconductor laser device of the present invention, a strain applying member having a linear expansion coefficient different from that of the semiconductor laser element is provided on one surface of the semiconductor laser element having a pair of opposed surfaces via the first bonding layer. And the heat radiation member is bonded to the other surface of the semiconductor laser element via the second bonding layer made of a material having a lower hardness than the first bonding layer. On the other hand, stress is transmitted from the side of the strain applying member, and strain is thereby added. On the other hand, the heat generated in the semiconductor laser reaches the heat radiating member without passing through the strain applying member. However, since the hardness of the second bonding layer is relatively low, the thermal stress from the heat radiating member is hardly transmitted. Therefore, distortion can be applied to the semiconductor laser element with a simple process, and thermal stress can be relaxed without reducing the exhaust heat efficiency. As a result, a semiconductor laser device that exhibits good laser characteristics even during high-temperature operation can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of a semiconductor laser device 1 according to an embodiment of the present invention. The semiconductor laser device 1 includes a strain applying member 11 and a heat sink 12 above and below the semiconductor laser bar 10. A bonding layer 10 a (first bonding layer) is provided between the semiconductor laser bar 10 and the strain applying member 11, and a bonding layer 10 b (second bonding layer) is provided between the semiconductor laser bar 10 and the heat sink 12. Yes.

  The semiconductor laser bar 10 is a semiconductor laser element in which a plurality of light emitting regions are arranged in an array, and the width in the major axis direction is, for example, 10 mm, the resonator length is, for example, 200 μm to 1.5 mm, and the thickness is, for example, 100 μm. ing. In the semiconductor laser bar 10, for example, the substrate side is the n side of the pn junction, and the strain applying member 11 is joined to the n side, and the heat sink 12 is joined to the p side.

  The semiconductor laser bar 10 is obtained by forming a semiconductor layer including an active layer (light emitting region) on a substrate made of, for example, gallium arsenide (GaAs). The semiconductor layer is formed by laminating, for example, a lower clad layer, an active layer, an upper clad layer, a current injection layer (all not shown), and is made of, for example, an AlGaInP compound semiconductor. The AlGaInP-based compound semiconductor here is a quaternary semiconductor including at least one of aluminum (Al) and gallium (Ga) and at least one of indium (In) and phosphorus (P). Examples thereof include AlGaInP mixed crystals, GaInP mixed crystals, and AlInP mixed crystals. These contain an n-type impurity such as silicon (Si) or selenium (Se), or a p-type impurity such as magnesium (Mg), zinc (Zn), or carbon (C) as necessary. With such a configuration, red light having an oscillation wavelength of, for example, 630 μm to 690 μm is emitted. An n-type electrode is formed on the back surface of the substrate, and a p-type electrode is formed on the semiconductor layer on the front surface side (not shown).

The strain applying member 11 is made of a material having a linear expansion coefficient different from that of the semiconductor laser bar 10. Specifically, when the semiconductor laser bar 10 is made of a GaAs-based material as described above, a material having a linear expansion coefficient smaller than that of GaAs (5.9 × 10 ⁻⁶ / ° C.), For example, silicon carbide (linear expansion coefficient: 3.5 × 10 ⁻⁶ / ° C.), aluminum nitride (linear expansion coefficient: 4.5 × 10 ⁻⁶ / ° C.), or a material containing diamond (linear expansion coefficient: 1. A ceramic material such as 0 to 3.0 × 10 ⁻⁶ / ° C., for example, CVD diamond: 2.0 × 10 ⁻⁶ / ° C. is used. By selecting such a material, it is possible to apply a stretching stress to the semiconductor laser bar 10 at the time of mounting, thereby adding − (minus) strain.

  The thickness of the strain applying member 11 is preferably determined in relation to the thickness of the semiconductor laser bar 10 and the resonator length. Specifically, when the thickness of the semiconductor laser bar 10 is about 100 μm, the thickness of the strain applying member 11 is preferably 10 μm or more and 2 mm or less. As a result, the semiconductor laser 10 or the strain applying member 11 is less likely to be damaged due to warpage that occurs during bonding with the semiconductor laser 10.

  The heat sink 12 enhances the exhaust heat effect of the semiconductor laser bar 10, and is a material having thermal conductivity, for example, a single material such as copper (Cu), aluminum (Al), tungsten (W), molybdenum (Mo) or the like. For example, a copper tungsten alloy (Cu—W), a copper molybdenum alloy (Cu—Mo), aluminum nitride (AlN), silicon carbide (SiC), or the like. However, it is preferable that it is comprised with the copper simple substance with high heat conductivity, and the alloy containing copper. The thickness of the heat sink 12 is, for example, 1 mm to 20 mm. Note that the surface of the heat sink 12 (the surface on which the semiconductor laser bar 10 is provided) is covered with a thin film (not shown) made of, for example, gold (Au) or the like in order to increase the electrical conductivity with respect to the semiconductor laser bar 10. .

  The bonding layer 10a is made of, for example, a bonding metal such as solder, and is made of a material that is harder (has higher hardness) than the bonding layer 10b described later. Moreover, it is preferable to be comprised with the material whose melting | fusing point is higher than the below-mentioned joining layer 10b, for example, material whose melting | fusing point is 185 degreeC-300 degreeC. Specifically, it is preferably made of an alloy containing tin, for example, eutectic solder such as Au—Sn, Sn—Ag, Sn—Zn, and Sn—Pb.

  The joining layer 10b is made of, for example, a joining metal such as solder, and is made of a softer material (having a lower hardness) than the joining layer 10a. Moreover, it is preferable to be comprised with the material whose melting | fusing point is lower than the above-mentioned joining layer 10a, for example, material whose melting | fusing point is 115 to 160 degreeC. Specifically, it is preferably composed of an alloy containing indium, and the content is more preferably 50% or more. Or you may be comprised by the material containing 3 or more types of metals, ie, the ternary system, the quaternary system or more metal material.

  The semiconductor laser device 1 having the above configuration can be manufactured, for example, as follows. 2A to 2C illustrate the mounting method of the semiconductor laser bar 10 in the order of steps, and correspond to the mounting method of the semiconductor laser element of the present invention.

First, the semiconductor laser bar 10 is formed. For example, a compound semiconductor layer is formed on a substrate made of GaAs, for example, by MOCVD (Metal Organic Chemical Vapor Deposition) or MBE (Molecular Beam Epitaxy). At this time, for example, trimethylaluminum (TMA), trimethylgallium (TMG), trimethylindium (TMIn), and phosphine (PH ₃ ) are used as raw materials for the AlGaInP-based compound semiconductor as described above. For example, hydrogen selenide (H ₂ Se) is used, and dimethyl zinc (DMZ) is used as the acceptor impurity raw material, for example. Subsequently, electrodes are respectively formed on the surface of the formed compound semiconductor layer and the back surface of the GaAs substrate by vapor deposition, sputtering, or the like. After that, the semiconductor laser bar 10 is formed by providing a mirror film (not shown) on the pair of end faces in the axial direction.

  Next, as shown in FIG. 2A, a strain applying member 11 made of the above-described material is prepared, and a joining layer made of the above-described material is formed on the strain adding member 11 by, for example, a vacuum deposition method or a plating method. 10a is formed. After that, the semiconductor laser bar 10 is mounted on the bonding layer 10a, and the semiconductor laser bar 10 is bonded to the strain applying member 11 by performing heating and cooling treatment (heat treatment).

  On the other hand, as shown in FIG. 2B, the heat sink 12 made of the above-described material is prepared, and the bonding layer 10b made of the above-described material is formed on the heat sink 12 by, for example, vacuum deposition or plating. .

  Subsequently, as shown in FIG. 2C, the strain applying member 11 is arranged so that the semiconductor laser bar 10 joined to the strain applying member 11 and the joining layer 10b formed on the heat sink 12 face each other. By superposing the heat sink 12 and performing a heating and cooling process, the bonding layer 10b is melted and solidified to be bonded. Thereby, the semiconductor laser device 1 shown in FIG. 1 is completed.

  Alternatively, in addition to the joining method of FIGS. 2A to 2C, for example, a method as shown in FIGS. 3A to 3C can be used. First, as shown in FIG. 3A, the bonding layer 10a is formed on the strain applying member 11 by, for example, a vacuum deposition method or a plating method. On the other hand, as shown in FIG. In addition, the bonding layer 10b is formed by, for example, a vacuum deposition method or a plating method. After that, as shown in FIG. 3C, the heat sink 12 and the strain applying member 11 are superposed and subjected to a heating and cooling process to join them. At this time, when the melting point of the material forming the bonding layer 10a is relatively high and the melting point of the material forming the bonding layer 10b is relatively low, the bonding layer 10a first hardens first, and then the bonding layer 10b hardens. It will be. That is, the strain applying member 11 is bonded to the semiconductor laser 10 first, and then the heat sink 12 is bonded.

  Next, the mounting method of the semiconductor laser bar 10 of this embodiment and the operation and effect of the semiconductor laser device 1 will be described.

  In the mounting method of the semiconductor laser bar 10, the strain applying member 11 having a linear expansion coefficient different from that of the semiconductor laser bar 10 is bonded to the upper surface (n side) of the semiconductor laser bar 10 via the bonding layer 10 a, so Thermal stress due to the difference in linear expansion coefficient is applied to the laser bar 10. At this time, since the strain applying member 11 is made of a material having a smaller linear expansion coefficient than that of the semiconductor laser bar 10, stretching stress is applied to the semiconductor laser bar 10 from the strain adding member 11 side by cooling after heating at the time of bonding. It takes. In particular, by using a material having a relatively high (hard) hardness as the bonding layer 10a, the stress applied to the semiconductor laser bar 10 from the strain applying member 11 is easily transmitted.

  On the other hand, by joining the heat sink 12 to the lower surface (p side) of the semiconductor laser bar 10 via the joining layer 10b, the strain application member 11 does not prevent the heat conduction from the semiconductor laser bar 10 to the heat sink 12. Further, by using a material having a relatively low (soft) hardness as the bonding layer 10b, it becomes difficult for thermal stress (compressive stress) due to the difference in linear expansion coefficient from the heat sink 12 to the semiconductor laser bar 10 to be transmitted.

  For example, as shown in FIG. 4A, when the linear expansion coefficient of the strain applying member 11 is small and the linear expansion coefficient of the heat sink 12 is large with respect to the semiconductor laser bar 10, the semiconductor is cooled by heating and then cooled. The laser bar 10 is subjected to a stretching stress P1 from the strain applying member 11 side and a compressive stress P2 from the heat sink 12 side. At this time, since the hardness of the bonding layer 10a is relatively high, the stretching stress P1 from the strain applying member 11 is sufficiently transmitted to the semiconductor laser bar 10, while the hardness of the bonding layer 10b is relatively low, Is absorbed by the bonding layer 10 b and is not easily transmitted to the semiconductor laser bar 10.

  Further, by joining the strain applying member 11 to the n side of the semiconductor laser bar 10, a load is not directly applied to the p side serving as a light emitting point due to the stress from the strain adding member 11. Therefore, a desired strain is added to the semiconductor laser bar 10 without causing a decrease in light emission efficiency or oscillation inhibition.

  Further, as shown in FIG. 4B, the strain applying member 11 and the heat sink 12 are provided above and below the semiconductor laser bar 10, so that the heat T generated from the semiconductor laser bar 10 is generated from the heat sink 12 side. In addition, heat can be exhausted not only from the strain adding member 11 side. That is, the exhaust heat effect can be obtained not only from the p side but also from the n side.

  In addition, by using a eutectic solder material containing tin as the bonding layer 10a and using a material containing indium as the bonding layer 10b, the stress from the strain applying member 11 to the semiconductor laser bar 10 can be more easily transmitted. The stress from 12 to the semiconductor laser bar 10 is less likely to be transmitted.

  Further, by bonding the strain applying member 11 to the n side of the semiconductor laser bar 10, it is not necessary to perform wire bonding for each laser, so that the strain applying member 11 can be applied collectively. For this reason, in order to improve adhesiveness with a wire, for example, load conditions, such as weight and hitting time, can be strengthened. Furthermore, since a thin plate or the like can be used instead of the wire, the processing is easy.

  Further, by joining the strain applying member 11 to the n side of the semiconductor laser bar 10, the positional accuracy at the time of mounting is not required as compared with the conventional case where a submount is provided between the semiconductor laser bar and the heat sink. Therefore, the mounting process is simplified and the cost is reduced.

  As described above, the strain applying member 11 is bonded to the semiconductor laser bar 10 from the strain adding member 11 by joining the semiconductor laser bar 10 to the n side of the semiconductor laser bar 10 via the bonding layer 10a. Stretching stress is applied, and − (minus) strain can be added without changing the crystal growth conditions. On the other hand, by bonding the heat sink 12 to the p side of the semiconductor laser bar 10 via the bonding layer 10 b, the heat conduction to the heat sink 12 is not hindered by the strain applying member 11. In particular, since the hardness of the bonding layer 10a is relatively high, stress is easily transmitted from the strain applying member 11 to the semiconductor laser bar 10, and since the hardness of the bonding layer 10b is relatively low, the heat sink 12 is transferred from the semiconductor laser bar 10 to the semiconductor laser bar 10. It becomes difficult to transmit thermal stress. Therefore, distortion can be added to the semiconductor laser bar by a simple process, and thermal stress can be relaxed without reducing the exhaust heat efficiency. As a result, the semiconductor laser device 1 that exhibits good laser characteristics even during high-temperature operation can be realized.

  Next, specific examples will be described.

(Examples 1A and 1B)
As Example 1A, the width in the major axis direction of the semiconductor laser bar 10 when the n side (substrate side) of the semiconductor laser bar 10 was bonded to the strain applying member 11 was measured. Further, as Example 1B, the width in the major axis direction of the semiconductor laser bar 10 when the p-side of the semiconductor laser bar 10 was bonded onto the heat sink 12 via the bonding layer 10b was measured. At this time, the width in the major axis direction was measured at three points on the n side, the light emitting region, and the p side of the semiconductor laser bar 10. Further, as the semiconductor laser bar 10, the above-mentioned GaAs-based material was used, the width in the major axis direction before bonding was 10 mm, the resonator length was 700 μm, and the thickness was 100 μm. As the strain applying member 11, silicon carbide having a thickness of 200 μm was used, and as the bonding layer 10 a, Sn—Ag solder having a thickness of 5 μm was used. As the heat sink 12, copper having a thickness of 4.5 mm was used, and as the bonding layer 10b, indium solder having a thickness of 10 μm was used. The measurement results are shown in FIG.

(Example 1C)
As Example 1C, in the semiconductor laser device 1 manufactured under the same conditions as in Examples 1A and 1B, the temperature rise (Δt ° C.) relative to the environmental temperature (25 ° C.) during the operation of the semiconductor laser bar 10 was measured. The result is shown in FIG.

(Comparative Example 1)
Further, as Comparative Example 1 of Examples 1A and 1B, as shown in FIG. 7, the long axis direction of the semiconductor laser bar 100 in the semiconductor laser device 20 in which the semiconductor laser bar 100 is joined to the heat sink 102 via the submount 101 is used. The width of was measured. At this time, the semiconductor laser bar 100 was bonded to the submount 101 via the bonding layer 100a in a p-side down manner, and the submount 101 was bonded to the heat sink 102 via the bonding layer 101a. At this time, Sn—Ag solder having a thickness of 5 μm was used as the bonding layer 100a, and indium solder having a thickness of 10 μm was used as the bonding layer 101b. In addition, as the semiconductor laser bar 100, the submount 101, and the heat sink 102, the same ones as in Examples 1A and 1B were used. The result of Comparative Example 1 is shown in FIG. 5A together with the results of Examples 1A and 1B.

(Comparative Example 2)
Further, as Comparative Example 2 of Example 1C, as shown in FIG. 8, the environmental temperature during operation of the semiconductor laser bar 110 in the semiconductor laser device 30 in which the semiconductor laser bar 110 is bonded to the heat sink 112 via the bonding layer 110a. The temperature increase (Δt ° C.) relative to (25 ° C.) was measured. The result is shown in FIG. 5 (B) together with the result of Example 1C. FIG. 5B also shows the temperature rise (Δt ° C.) of the semiconductor laser bar 100 in the semiconductor laser device 20 according to Comparative Example 1 shown in FIG.

  As shown in FIG. 5A, in Example 1A in which the strain applying member 11 is joined to the n side of the semiconductor laser bar 10 via Sn—Ag solder, a sufficient stretching effect is obtained in the semiconductor laser bar 10. . Therefore, it is shown that the stretching stress from the strain applying member 11 is sufficiently transmitted to the semiconductor laser bar 10, and it can be seen that the strain is reliably added. Further, in Example 1A, in the three regions of the n side, the light emitting region, and the p side, the stretching effect is almost the same as that of Comparative Example 1 in which the submount 101 is bonded to the p side of the semiconductor laser bar 100. That is, under the conditions as described above, the same behavior (stretching) is observed in any of the above three regions of the semiconductor laser bar even when a stretching stress is applied from either the p side or the n side. It can be seen that the degree is almost the same.

  In Example 1B in which the semiconductor laser bar 10 and the heat sink 12 are joined via indium solder, there is almost no shrinkage in the major axis direction. Therefore, it can be seen that the stress from the heat sink 12 to the semiconductor laser bar 10 is relieved by the indium solder.

  As shown in FIG. 5B, in the configuration of the comparative example 1 in which the submount 101 is provided between the semiconductor laser bar 100 and the heat sink 102, the temperature rise was the largest. On the other hand, in Example 1C in which the semiconductor laser bar 10 was joined to the heat sink 12 without the strain applying member 11, the temperature rise was almost the same as in Comparative Example 1 in which the semiconductor laser bar 110 was joined to the heat sink 112. The temperature was about 10 ° C. lower than that of Comparative Example 1 in which bonding was performed via the mount 101. Therefore, in Example 1C, it turns out that the exhaust heat efficiency from the semiconductor laser bar 10 to a heat sink does not fall.

  From the above results, the strain applying member 11 is joined to the n side of the semiconductor laser bar 10 using, for example, Sn-Ag solder, while the heat sink 12 is joined to the p side of the semiconductor laser bar 10 using, for example, indium solder. It can be seen that stress is applied to the semiconductor laser bar 10 from the n side and strain is added, while the stress is relaxed on the p side without reducing the exhaust heat efficiency.

  FIG. 6 shows the oscillation wavelength (nm) with respect to the indium content (%) in the indium solder used as the bonding layer 10b. Thus, for example, as the content of indium in the bonding layer 10b of the semiconductor laser device configured to have a wavelength of 804 nm is shifted to the short wavelength side. This is because the hardness increases as the indium content of the bonding layer 10 b decreases, and the stress from the heat sink 12 is easily received. For this reason, it is preferable that the bonding layer 10b has an indium content of about 50% or more, whereby stress from the heat sink 12 is sufficiently relaxed, and good light emission efficiency and life characteristics can be realized.

  In the configuration as in Comparative Example 1, in order to add a desired strain to the semiconductor laser bar 100, for example, it is assumed that a constant stress is applied from the p side due to a difference in linear expansion coefficient with the submount 101. By setting the strain to be added at the crystal growth stage above, a design technique that can obtain a desired strain as a whole may be used. For example, if the desired strain for improving the light emission efficiency is − (minus) strain 0.7%, it is assumed that −0.1 strain is added by joining with the submount 101 in advance. The strain applied at the crystal growth stage of the layer is designed to be −0.6% strain. In such a case, the submount 101 provided between the semiconductor laser bar 100 and the heat sink 102 not only functions as a stress relaxation material from the heat sink 102 to the semiconductor laser bar 100 but also adds strain to the semiconductor laser bar 100. It is also used as an auxiliary means.

  In this way, the mounting method of the present invention can be effectively used for a semiconductor laser bar in which crystal growth conditions are set in advance, assuming a strain due to stress received from the submount. As described above, the p-side and n-side of the semiconductor laser bar 10 have substantially the same behavior and degree with respect to stress. Therefore, the sub-heat considering the heat removal efficiency without changing the crystal growth conditions of the semiconductor laser bar 10. This is because even if the mount is bonded to the n side, the same amount of strain can be applied as when the mount is bonded to the p side.

  Although the present invention has been described with reference to the embodiment and the modification, the present invention is not limited to the above-described embodiment and the like, and various modifications can be made.

  For example, in the above embodiment and the like, the strain is applied only by the difference in linear expansion coefficient between the strain applying member 11 and the semiconductor laser bar 10, but the present invention is not limited to this. For example, the crystal growth of the active layer It is also possible to add a strain at the stage and configure the total amount of the auxiliary strain and the strain added by the stress from the strain adding member 11 to be a desired strain amount.

  In the above-described embodiment, the example in which the semiconductor laser bar 10 is bonded onto the heat sink 12 has been described. However, the present invention is not limited to this, and other heat radiating members and cooling elements such as a heat radiating fan and Peltier element are provided. Also good.

  Moreover, in the said embodiment etc., although the board | substrate side of the semiconductor laser bar 10 demonstrated the example which is the n side of a pn junction, it is not limited to this, It is the structure by which the p side and the n side are reversed. There may be. Moreover, although the example which joins the semiconductor laser bar 10 to the heat sink 12 by p side down was given and demonstrated, it is not limited to this, You may make it join the n side with respect to the heat sink 12.

  Further, in the above-described embodiment and the like, a case has been described in which stretching stress is applied using a material having a linear expansion coefficient smaller than that of the semiconductor laser bar 10 as the strain applying member 11 to add − (minus) strain. It is not limited. For example, + (plus) strain may be added depending on the material, film thickness, oscillation wavelength, and the like of the semiconductor layer constituting the semiconductor laser bar 10. In this case, a compressive stress is applied to the semiconductor laser bar 10 by using a material having a larger linear expansion coefficient than the semiconductor laser bar 10 as the strain applying member 11.

  In the above-described embodiment and the like, an example in which the semiconductor laser bar 10 is configured by a GaAs substrate has been described. However, the present invention is not limited to this, and another substrate such as an InP system or Si system may be used. Good. Further, although an example in which an AlGaInP-based compound semiconductor is formed on a substrate has been described, the present invention is not limited thereto, and other compound semiconductors such as AlInP-based, GaInAsP-based, GaInN-based, AlGaInN-based, AlGaAs-based, InGaAs-based, InP The present invention is also applicable to systems such as GaInAsNP.

  In the above-described embodiment and the like, the semiconductor laser element of the present invention has been described by taking as an example the semiconductor laser bar 10 having a plurality of light emitting regions in an array, but the present invention is not limited to this, and a single light emitting region is used. The present invention is also applicable to a semiconductor laser having the same.

1 is a cross-sectional view illustrating a schematic configuration of a semiconductor laser device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a manufacturing method of the semiconductor laser device illustrated in FIG. 1 in order of steps. It is a figure showing other manufacturing methods of the semiconductor laser device shown in Drawing 1 in order of a process. It is a figure for demonstrating the effect | action of the semiconductor laser apparatus shown in FIG. It is a characteristic view showing the (A) major axis direction width | variety and (B) temperature rise of the semiconductor laser bar concerning an Example and a comparative example. It is a characteristic view showing the oscillation wavelength with respect to an indium content rate. It is sectional drawing showing schematic structure of the conventional semiconductor laser apparatus. It is sectional drawing showing schematic structure of the conventional semiconductor laser apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser apparatus, 10 ... Semiconductor laser bar, 11 ... Submount, 12 ... Heat sink, 10a, 10b ... Joining layer.

Claims (13)

Bonding a strain applying member having a linear expansion coefficient different from that of the semiconductor laser element to one surface of the semiconductor laser element having a pair of opposed surfaces via a first bonding layer;
Bonding a heat radiating member to the other surface of the semiconductor laser element through a second bonding layer made of a material having a hardness lower than that of the first bonding layer. Device manufacturing method. The method of manufacturing a semiconductor laser device according to claim 1, wherein the strain applying member is made of a material having a smaller linear expansion coefficient than the semiconductor laser element. The method of manufacturing a semiconductor laser device according to claim 1, wherein the first bonding layer is made of a material containing tin (Sn). The first bonding layer is made of a material further including at least one of gold (Au), silver (Ag), zinc (Zn), lead (Pb), and copper (Cu). A method of manufacturing a semiconductor laser device according to claim 3. The method of manufacturing a semiconductor laser device according to claim 1, wherein the first bonding layer is made of eutectic solder. The method for manufacturing a semiconductor laser device according to claim 1, wherein the second bonding layer is made of a material having a melting point lower than that of the first bonding layer. The method of manufacturing a semiconductor laser device according to claim 1, wherein the second bonding layer is made of a material containing indium (In). The method of manufacturing a semiconductor laser device according to claim 1, wherein the second bonding layer is made of a material containing at least three kinds of metals. The semiconductor laser element has a semiconductor layer including the light emitting region on a substrate,
The strain applying member is bonded to the substrate side via the first bonding layer, and the heat dissipation member is bonded to the semiconductor layer side via the second bonding layer. 2. A method of manufacturing a semiconductor laser device according to 1. The method of manufacturing a semiconductor laser device according to claim 1, wherein the semiconductor laser element is made of a material containing gallium arsenide (GaAs). The method of manufacturing a semiconductor laser device according to claim 9, wherein the strain applying member is made of a material containing silicon carbide (SiC), aluminum nitride (AlN), or diamond (C). The method of manufacturing a semiconductor laser device according to claim 1, wherein the heat radiating member is made of a material containing copper (Cu). A semiconductor laser element having a pair of opposing surfaces;
A strain applying member provided on one surface of the semiconductor laser element via a first bonding layer, and having a linear expansion coefficient different from that of the semiconductor laser element;
A semiconductor laser comprising: a heat radiating member joined to the other surface of the semiconductor laser element via a second joining layer made of a material having a hardness lower than that of the first joining layer. apparatus.

Images