CN102005700B - Semiconductor laser device - Google Patents

Abstract

The invention provides a semiconductor laser device, capable of reducing the angle deviation along the polarization direction, comprising a laser array composed of a first lamination body with a ridge type wave guide and sending the light of first wavelength, a second lamination body separated from a clamping groove and sending the light of second wavelength longer than the first wavelength, first, second electrodes containing gold films on the first, second lamination bodies; a bottom seat composed of an insulation body, a base metal film and first, second conductive layers of the gold film in the thickness of 0.05-03 Mum which are arranged on the insulation body in turn; a first alloy solder layer for joining the first electrode and the first conductive layer and having the thickness thicker than the gold film of the first conductive layer, wherein the inclination angle of the side surface of the ridge type wave guide near to the groove is smoother than the inclination angle of the side surface far away from the groove.

Description

semiconductor laser device

technical field

The present invention relates to semiconductor laser devices.

Background technique

Using a monolithic laser array in which semiconductor lasers with different wavelengths are integrated on one chip can simplify the structure of a DVD/CD compatible optical disc drive and facilitate miniaturization.

The optical system of the optical disk drive device has optical elements such as a dichroic prism, a beam splitter, a collimator lens, a wave plate, an objective lens, and an erecting mirror. At this time, if the laser beams are brought close to each other at an interval of 100 to 150 μm, it is easy to satisfy the characteristics of the optical element at different wavelengths.

However, in order to achieve further miniaturization, further simplification of the optical system is required. For this reason, it is important to further reduce fluctuations in the characteristic distribution of semiconductor lasers.

When the main surface of the crystal growth substrate of the monolithic laser array is inclined from the (100) crystal plane by several to tens of degrees, high device characteristics such as reduced operating current can be obtained. However, in the vicinity of the light-emitting layer of a laser array having an MQW (Multiple Quantum Well) structure provided on such an inclined substrate, stress tends to occur, resulting in angular deviation of the polarization direction. Moreover, if alloy solder is used to bond the chip of the laser array to the submount, the cooling process will stress the light-emitting layer. This stress sometimes further increases the deviation of the polarization direction. If the angular deviation increases, it will increase the noise defect of the returned light.

A technical example related to a semiconductor laser element capable of suppressing a decrease in polarization characteristics has already been disclosed (Patent Document 1). In this example, by arranging the respective waveguides in the first and second laser elements within an appropriate range of positions in plan view, degradation in polarization characteristics is suppressed.

However, even with this example, the angular deviation of the polarization direction cannot be sufficiently reduced.

<Patent Document 1> Japanese Unexamined Patent Publication No. 2008-258341

Contents of the invention

The present invention provides a semiconductor laser device capable of reducing the angular deviation of the polarization direction.

According to one aspect of the present invention, there is provided a semiconductor laser device characterized by comprising: a laser array having: a semiconductor substrate; a first laminated body, a second laminated body that emits light of a second wavelength longer than the first wavelength and is separated from the first laminated body with a groove interposed therebetween, and placed on the semiconductor substrate; A first electrode comprising a gold film disposed on the above-mentioned second laminated body, and a second electrode comprising a gold film disposed on the above-mentioned second laminated body; a base, the base has: an insulator, a first base metal film disposed on the above-mentioned insulator, and The first conductive layer of the first gold film with a thickness in the range of 0.05 to 0.3 μm provided on the first base metal film, the second base metal film provided on the above-mentioned insulator, and the second base metal film on the above-mentioned second base metal film The second conductive layer of the second gold film with a thickness in the range of 0.05-0.3 μm; the first electrode and the first conductive layer are joined and thicker than the first gold film of the first conductive layer The first alloy solder layer; and the second alloy solder layer that joins the second electrode and the second conductive layer and is thicker than the second gold film of the second conductive layer; one side of the ridge waveguide close to the groove The inclination angle of the side surface on the side is gentler than the inclination angle of the side surface on the side farther from the groove.

Provided is a semiconductor laser device capable of reducing angular deviation of polarization directions.

Description of drawings

FIG. 1 is a schematic cross-sectional view of Embodiment 1. FIG.

FIG. 2 is a schematic diagram of a laser array and mounting components in Embodiment 1. FIG.

FIG. 3 is a graph showing the distribution of deviation angles of polarization directions.

FIG. 4 is a graph showing the dependence of the standard deviation of the off angle on the thickness of the gold film.

Fig. 5 is a schematic sectional view of the vicinity of an alloy solder layer.

Fig. 6 is a binary phase equilibrium diagram of AuSn.

FIG. 7 is a diagram showing stress distribution in a cross section.

Fig. 8 is a schematic cross-sectional view of an inclined substrate of a comparative example

FIG. 9 is a graph showing a profile of deviation angles in a comparative example.

Fig. 10 is a schematic diagram of an optical disk drive device.

(Description of Reference Signs)

5: laser array; 10: semiconductor substrate; 12: laminate; 12c: groove; 14: p-side electrode; 16: alloy solder layer; 20: base; 126: ridge waveguide; 200: insulator; 201: base metal film; 202: gold film; 203: conductive layer; α: side inclination on the groove side; β: side inclination on the opposite side to the groove

Detailed ways

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

FIG. 1 is a schematic cross-sectional view of a semiconductor laser device according to an embodiment of the present invention.

The semiconductor laser device includes: a laser array 5 , a base 20 , alloy solder layers 16 , 207 and leads 30 .

The laser array 5 has, on a semiconductor substrate 10 made of n-type GaAs or the like: a first stack 12a including a light-emitting layer, a second stack 12b including a light-emitting layer, and a first p-layer provided on the first stack 12a. The side electrode 14a, and the second p-side electrode 14b provided on the second laminated body 12b.

The base 20 has first and second conductive layers 203a, 203b on one face of the insulating material 200 . In addition, the base 20 has a backside conductive layer on the other side of the insulating material 200 . The first conductive layer 203a is connected to the first p-side electrode 14a of the laser array 5 by the alloy solder layer 16a, and the second conductive layer 203b is connected to the second p-side electrode 14b of the laser array 5 by the alloy solder layer 16b.

In addition, the first conductive layer 203 a is connected to a first lead terminal (not shown) by a bonding wire 40 , and the second conductive layer 203 b is connected to a second lead terminal (not shown) by a bonding wire 42 .

The material of the insulating material 200 may be AlN, SiC, Si, TiN, glass epoxy resin and the like. Among them, AlN is preferable because it has a high thermal conductivity of 150 W/mK and a linear expansion coefficient of 4×10 ^-6 /K which is close to that of GaAs, which is 5.9×10 ^-6 /K.

The conductive layer on the back of the base 20 has a base metal film 205 and a gold film 206 made of Ti or the like, and is bonded to the lead 30 by an alloy solder layer. Thereby, the light having the first wavelength emitted from the light-emitting layer of the first laminated body 12a and the light having the second wavelength longer than the first wavelength emitted from the light-emitting layer of the second laminated body 12b respectively travel toward the paper surface. emitted in the vertical direction.

If the first wavelength is set around 650nm and the second wavelength is set around 780nm, it can be used as a light source for a DVD/CD compatible optical disc drive. In such a monolithic laser array, if the light-emitting point interval is in the range of 110±10 μm, the optical system can be shared, and the optical disk drive device can be easily miniaturized.

Figure 2(a) is a schematic sectional view of the laser array, Figure 2(b) is an enlarged schematic sectional view near area B, Figure 2(c) is an enlarged schematic sectional view near area C, and Figure 2(d) is a base schematic cross-section.

As shown in FIG. 2(a), the main surface 10a of the semiconductor substrate 10 composed of n-type GaAs having a zinc blende crystal structure is 3 to 20 from the low-order crystal plane such as the (100) crystal plane. degree, preferably a surface inclined in the range of 10 to 15 degrees. On such a surface, if the first and second stacked bodies 12a, 12b are crystal-grown by, for example, MOCVD (metal organic chemical vapor deposition) or MBE (molecular beam epitaxy), it is easy to suppress natural ultrasonography that hinders wavelength shortening. The generation of lattice, and it is easy to improve the efficiency of impurity doping. Therefore, it is possible to realize a semiconductor laser that emits light at a wavelength near 650 nm, which is within the DVD standard range, and has a low operating current. In addition, the light-emitting point interval is represented by D.

As shown in Fig. 2(b) and Fig. 2(c), the laminated body 12 is, for example, a first cladding layer 121 made of InGaAlP, a light-emitting layer 122, and a first cladding layer 122 made of InGaAlP formed on the semiconductor substrate 10 by different processes. Second cladding 123 . For example, the second wavelength 780 nm side is first grown, and then the region to be the first wavelength 650 nm side is removed by etching or the like, and then the laminated body on the first wavelength 650 nm side is formed. The first stacked body 12 a and the second stacked body 12 b are made to have substantially the same height, except for the stacked body on the first wavelength side formed on the second wavelength side. In this way, it is easy to make the heights of the light emitting points substantially the same. At this time, if the first stacked body 12a is a buried heterostructure (SBR: selectively buried ridge band) that becomes a ridge waveguide along the optical axis of the optical resonator, the transverse mode of the laser beam can be controlled, and it is easy to satisfy, for example, Specifications for DVD. Furthermore, if the second laminated body 12b is also the ridge waveguide 126b, the manufacturing process can be further simplified.

The light-emitting layer 122a on the side of the first wavelength of 650 nm is made of an InGaAlP-based semiconductor. In addition, the light-emitting layer 122b on the side of the second wavelength of 780 nm is made of a GaAlAs-based semiconductor. If the 650nm laser device has an MQW structure, it is easy to control optical characteristics and electrical characteristics including wavelength and FFP (far-field image) with high precision, and satisfies DVD specifications. In the light-emitting layer having an MQW structure, although the composition of the InGaP well layer is adjusted to apply a compressive strain of usually 1% or less to stabilize the polarization direction, other strains are generated due to thermal stress generated in the cooling process after the pedestal bonding .

On the other hand, a 780-nm semiconductor laser device can satisfy the standards for CD as, for example, a bulk-structured light-emitting layer. The effect of strain is suppressed in the bulk structure. Next, a description will be given of a 650 nm semiconductor laser in which the influence of strain in the light emitting layer tends to relatively increase.

In the manufacturing process of the first and second laminated bodies 12a, 12b into the ridge-shaped laser array 5, the second cladding layer 123 is processed, for example, into the ridge-shaped waveguides 126a, 126b by etching. The width Wa of the ridge waveguide 126 a and the width Wb of the ridge waveguide 126 b are several μm or less, and the depth thereof is approximately 0.2 μm or less. In addition, flat portions having thicknesses Ta, Tb within a range of 0.01 to 0.3 μm are formed on both sides of the ridge waveguides 126a, 126b, respectively. The n-type GaAs current blocking layer 124 is formed on both side surfaces and flat portions of the ridge waveguides 126a and 126b by the same process.

Furthermore, the contact layer 125 is formed so as to be in ohmic connection with the ridge waveguides 126a and 126b by the same process. Then, the intermediate portion is removed until the semiconductor substrate 10 is exposed, and the first stacked body 12a and the second stacked body 12b are separated by the groove 12c. Thus, a light beam of 650 nm is emitted from the light emitting region G, and a light beam of 780 nm is emitted from the light emitting region H.

By forming the current blocking layers 124 on both side surfaces of the ridge waveguide 126 having a cross section protruding toward the p-side electrode 14 and on both outer flat portions of the ridge waveguide, the transverse mode can be easily stabilized. Therefore, it can be used as a DVD/CD compatible optical disc drive.

First and second p-side electrodes 14a, 14b made of AuZn/Mo/Au or Ti/Pt/Au, etc. are formed, respectively. At this time, if the thickness of the Au film is 0.1 to 0.3 μm, the joint strength with the alloy solder layer 16 can be maintained well. Furthermore, if the solder alloy layers 16a, 16b are formed in a stripe pattern with a thickness of 0.5 to 10 μm, preferably 1 to 5 μm, bulk graining of the solder alloy layer can be suppressed, and mass productivity and reliability can be easily improved.

The material of the alloy solder layer 16 includes an alloy or a eutectic alloy which is a mixture. Among them, the eutectic alloy may contain a solid solution composed of two or more elements, such as AuSn, AuGe, and AuSi.

In the first and second conductive layers 203a, 203b shown in FIG. 2( d), the base metal films 201a, 201b provided between the insulating material 200 and the gold films 202a, 202b are alloys with gold whose melting point is higher than The melting point of the alloy solder material. In addition, it is a material such as Ti that has high adhesion to the insulating material 200 and the gold film 202 . In this way, part of the alloy of base metal film 201 and gold can be suppressed from melting into alloy solder layer 16 to increase its melting point. In addition, if Ni is used as the base metal film, it will form an alloy with Au at a lower temperature, and as a result, the composition of the alloy solder layer will be changed, which is not preferable.

In addition, the conductive layer on the back of the base 20 can be bonded with the lead wire 30 by the solder alloy layer 207 .

Fig. 3 (a) is a graph showing the distribution of the angle deviation of the polarization direction when the Au film thickness is 0.2 μm, and Fig. 3 (b) is a graph showing the distribution of the deviation angle of the polarization direction when the Au film thickness is 0.5 μm In the graph, the horizontal axis is the deviation angle (degree) of the polarization direction, and the vertical axis is the degree. They all have the cross-sectional structure shown in FIG. 1 .

The deviation angle takes the surface of the lead wire 30 as a reference to see the light exit surface, and the counterclockwise direction is positive, and the clockwise direction is negative. In addition, the wavelength of the semiconductor laser is 650 nm. In addition, the base metal film 201 is Ti.

When the thickness of the Au film 202 is 0.2 μm, when the sample number N is 105, the average value (Ave) of the deviation angle of the polarization direction is −0.73 degrees, and the standard deviation (σ) is 2.16 degrees. On the other hand, when the thickness of the Au film 202 is 0.5 μm, when the number of samples N is 105, the average value is −0.79 degrees, and the standard deviation is 4.04 degrees. Comparing the range of Ave ± 3σ, it is -7.2 to 5.76 degrees when the Au film thickness is 0.2 μm, and -12.91 to 11.33 degrees when the Au film thickness is 0.5 μm, and the variation range is more than double.

FIG. 4 is a graph showing the dependence of the standard deviation of the off angle on the thickness of the gold film. The vertical axis is the standard deviation of the deviation angle, and the horizontal axis is the gold film thickness Tc (μm).

If the thickness Tc of the gold film 202 is varied in the range of 0.05 to 0.5 μm, distribution diagrams as shown in FIG. 3 are respectively obtained. As a result, it was found that if the gold film thickness Tc is larger than 0.3 μm, the standard deviation of the off angle increases sharply. On the other hand, if the gold film thickness Tc is less than 0.05 μm, surface oxidation or the like is likely to occur, wire bonding to the conductive layer is difficult, and bonding strength with the alloy solder layer decreases. That is, it was found that the thickness Tc of the gold film is preferably not less than 0.05 μm and not more than 0.3 μm, more preferably not less than 0.1 μm and not more than 0.2 μm.

Fig. 5 is an enlarged schematic cross-sectional view near the alloy solder layer.

For example, the p-side electrode 14 has a width of about 60 μm and a thickness of 0.2 μm. In addition, the alloy solder layer 16 made of AuSn has a width of about 40 μm and a thickness of 2 μm.

In addition, FIG. 6 is a binary phase equilibrium diagram of AuSn. The horizontal axis is the molar ratio of Sn (Sn/[Au+Sn]), and the vertical axis is the absolute temperature T (K).

The boundary at which alloy solder changes from a liquid state to a solid state by cooling depends on its molar ratio. For example, when the molar ratio of Sn is around 0.3, the eutectic melting point is extremely low at about 551K (278°C). Using such a molar ratio of alloy solder makes it easy to join objects whose surfaces are covered with Au. However, if Au is excessively melted out from the object to be bonded to become Au-rich, the melting point shifts to the left as indicated by the arrow. In this case, the joint strength can be increased, but the liquid phase at a higher temperature will rapidly change to a solid solution. If the difference between the melting point and the room temperature increases, non-uniform bonding, increase in thermal stress, and fluctuation thereof tend to occur. Therefore, the strain in the vicinity of the light-emitting layer inside the laminate is increased, and the angle deviation of the polarization direction due to birefringence is increased or generated.

In this embodiment, the thickness Tc of the gold film 202 of the pedestal 20 is set to a relatively thin 0.05 to 0.3 μm. The alloy solder layer 16 is melted by heat conduction from the heated base 20 placed on the heater. Therefore, since the temperature of the gold film 202 on the surface of the base 20 tends to be higher than the temperature of the p-side electrode 14 in general, more gold melts into the eutectic. In the present embodiment, by setting the gold film 202 of the chassis 20 thin, the rise of the melting point can be suppressed.

On the other hand, since the temperature of the p-side electrode 14 is lower than that of the base 20 side, fusion of gold is suppressed. Actually, even if the p-side electrode 14 has a thickness of 5 μm, the melting point of the alloy solder layer 16 hardly rises, and the increase in standard deviation is suppressed. That is, like FIG. 5, the alloy solder layer 16a melts into a part of the gold film 202a of the p-side electrode 14a and the conductive layer 203a respectively, but the melting temperature range can be limited to the melting point of the alloy solder layer 16a before melting (or not The melting point is a slightly higher temperature range than the Au molar ratio).

Furthermore, it is preferable to set the thickness of the hardened alloy solder layers 16a, 16b to be larger than the thickness of the gold films 202a, 202b of the chassis 20 to increase the bonding strength. At this time, the gold film 202a of the pedestal 20 is much melted in the vicinity of the pedestal 20 where the temperature is high. That is, the melting point of the alloy solder layer 16 a tends to rise near the base 20 . In this embodiment, setting the thickness Tc of the gold film 202 to be relatively thin, ie, 0.05-0.3 μm, can effectively suppress the rise of the melting point and reduce the strain generated in the light-emitting layer. In addition, the melting spread range of the alloy solder layer 16a on the surface of the gold film 202a is limited. Therefore, in the gold film 202a on the base 20, a region not melted into the solder alloy layer remains in the outer peripheral portion of the molten region of the solder alloy layer 16a.

In addition, when the eutectic solder is AuGe, its minimum melting point is about 630K (357° C.), and its Sn molar ratio is about 0.28. Furthermore, when the eutectic solder is AuSi, its melting point is about 640K (367° C.), and the Sn molar ratio at its minimum point is about 0.2.

FIG. 7( a ) is a diagram showing the cross-sectional distribution of shear stress obtained by simulation, and FIG. 7( b ) is a diagram showing the cross-sectional distribution of equivalent stress obtained by simulation.

Stresses applied to the first laminate 12a by bonding using the alloy solder layer 16a include a corresponding stress T parallel to the bonding surface and a shear stress S parallel to the inner wall surface of the groove 12c.

When a laminate including a light-emitting layer is formed on an inclined substrate, the side surfaces of the ridge waveguide are (111A) crystal plane and (111B) crystal plane, which are left-right asymmetrical. When stress is applied to the left-right asymmetrical waveguide, strain is generated in the waveguide and birefringence is exhibited. Due to this birefringence, MQW strain, and the like, angular deviation occurs in the polarization direction also in the chip state. For example, the average value of the off angle in a junction-up structure in which the influence of thermal stress due to bonding is small is about -3.8 degrees. It can be considered that this value is close to the deviation angle of the chip state. On the other hand, in the present embodiment of FIG. 3, the average value is about -0.73 degrees. This means that the stress caused by die bonding reduces the average value of the angular deviation.

As seen in FIG. 7( a ), a shear stress S in the range of 0.90×10 ^-5 to 0.40×10 ^-4 N/μm ² is applied to the vicinity of the light emitting region G . This shearing stress is generated from the vicinity of the groove 12c. In addition, it can be seen from FIG. 7( b ) that the equivalent stress T in the range of 0.46×10 ^-4 to 0.92×10 ^-4 N/μm ² is applied to the vicinity of the light emitting region G . It is considered that the equivalent stress T is generated by the temperature-lowering process after bonding the insulator 200 having a different coefficient of linear expansion to the first laminate 12 a , or the like. From the above simulations, it was found that the shear stress S can be generated at a non-negligible level with respect to the corresponding stress T, and strain can be generated in the light emitting layer.

In this embodiment, as shown in FIG. 2( b ), the side surface of the ridge waveguide 126 a of the laser element having an emission wavelength of about 650 nm is set so that the inclination angle α of the side closer to the groove 12 c is larger than that of the side farther from the groove 12 c. The inclination β of (opposite side) is gentle. In this way, the absolute value of the angular misalignment tends to decrease and approach zero.

8( a ) is a schematic cross-sectional view of a semiconductor laser device according to a comparative example, and FIG. 8( b ) is an enlarged schematic cross-sectional view near E region.

In this comparative example, a laminated body 512 a is formed on an inclined semiconductor substrate 510 . At this time, the inclination angle of the semiconductor substrate 510 is substantially the same as that in the embodiment shown in FIG. 2 . On the side surface of the ridge waveguide 526a, the inclination angle on the side of the groove 512c is steeper than the inclination angle on the side opposite to the groove 512c. That is, the asymmetry of the ridge waveguide 526a is opposite to that of FIG. 2(b).

FIG. 9 is a graph showing a profile of deviation angles in a comparative example.

Since the thickness of the gold film is 0.2 μm, its standard deviation (σ) can be reduced to 2.0 degrees. On the other hand, the magnitude of the mean value (Ave) of the distribution is -5.6 degrees. That is, the direction in which the stress acts on the light emitting region G is opposite to that of the present embodiment, and it is difficult to reduce the angular deviation.

In addition, as a laser array having a left-right reverse cross-sectional structure with respect to Embodiment 1 shown in FIG. 1 , the average value of angular deviation can be made close to 0 and the standard deviation can be reduced. However, when the light emitting surface is viewed with the base 20 facing down, the light emitting regions of the laser elements of 650 nm and 780 nm are opposite to those in FIG. 1 . In addition, as long as the semiconductor laser device can be mounted upside down in the optical disk drive device, even if such a semiconductor laser device is used, the angular misalignment can be reduced.

10 is a schematic perspective view of an optical system of a DVD/CD compatible optical disc drive using the semiconductor laser device of this embodiment.

The optical system includes: a semiconductor laser device with a laser array 5 , a beam splitter 50 , a collimator lens 52 , a phase difference mirror 54 , and an objective lens 56 . The laser array 5 is bonded to the submount in a junction-down manner. The 650nm and 780nm light beams become linearly polarized light in the direction of the arrows respectively, and the distance between the light emitting points is close, that is, about 110 μm.

The beam splitter 50 reflects the two beams traveling along the optical axis B1 from the laser array 5 to travel along the optical axis B2. In addition, this beam splitter 50 passes the light reflected by the optical disc 58 and guides it to the light receiving element 60 as indicated by a dotted line. The beam splitter 50 is made of, for example, a dielectric multilayer film or a metal thin film, and can reflect light with a predetermined reflectance and transmit light with a predetermined transmittance.

The direction of the linearly polarized light beam emitted from the laser array 5 is a direction that enters the beam splitter 50 at 45 degrees, which is an intermediate value between p-polarized light and s-polarized light. The light beam adjusted to be substantially parallel by the collimator lens 52 travels along the optical axis B3 of the collimator lens 52 and enters the phase difference mirror 54 . The phase difference mirror 54 also functions as an upright mirror arranged at a position perpendicular to the optical axis B3 and the optical axis B4 of the objective lens 56 . In addition, the phase difference mirror 54 imparts a phase difference of 1/4 wavelength to the linearly polarized light incident at 45 degrees through the beam splitter 50 and converts it into circularly polarized light. That is, a parallel beam of circularly polarized light is incident on the objective lens 56 along the optical axis B4.

The objective lens 56 has a high NA (numerical aperture), converges the parallel light, and irradiates it on the optical disc 58 along the optical axis B5 into a tiny light spot. The reflected light from the optical disc 58 travels in opposite directions along the optical axes B5 and B4. When reflected by the phase difference mirror 54, the circularly polarized light returns to linearly polarized light, enters the light receiving element 60 through the beam splitter 50, and is taken out as a detection signal.

In the optical disk drive device of FIG. 10, instead of the 1/4 wave plate used to convert linearly polarized light into circularly polarized light and the prism that bends the optical path by 90 degrees toward the surface of the optical disk, a phase difference mirror arranged obliquely is used. 54. At this time, if the average value or standard deviation of the deviation angles of the polarization directions is large, the ratio of elliptically polarized light generated by the retardation mirror 54 increases. Therefore, the yield of the optical disc drive device decreases because the rate of increase in return light noise due to light returning to the laser array 5 increases. On the other hand, if the semiconductor laser device of this embodiment is used, as shown in FIG. 10 , a simple structure with reduced number of parts can be obtained, return light noise in the laser array can be suppressed, and an optical disk drive device can be manufactured with a high yield.

The embodiments have been described above with reference to the drawings. However, the present invention is not limited to these embodiments. Regarding the material, shape, size, arrangement, etc. of the laser array, laminated body, electrodes, semiconductor substrate, base, conductive layer, and alloy solder constituting the present invention, various design changes may be made by those skilled in the art, as long as they do not depart from the present invention. The main idea is also included in the scope of the present invention.

Claims (5)

1. A semiconductor laser device, characterized in that it comprises: A laser array comprising: a semiconductor substrate, a first laminate having a ridge-shaped waveguide and emitting light of a first wavelength provided on the semiconductor substrate, and being separated from the first laminate with a groove interposed therebetween. A second laminate on the semiconductor substrate that emits light of a second wavelength longer than the first wavelength, a first electrode including a gold film provided on the first laminate, and a second laminate provided on the second laminate A second electrode comprising a gold film on the A base, the base has: an insulator, a first base metal film disposed on the insulator, and a first conductive layer having a first gold film with a thickness in the range of 0.05-0.3 μm disposed on the first base metal film , and a second conductive layer having a second base metal film disposed on the above-mentioned insulator and a second gold film having a thickness in the range of 0.05-0.3 μm disposed on the second base metal film; a first alloy solder layer that joins the first electrode to the first conductive layer and is thicker than the first gold film of the first conductive layer; and a second alloy solder layer that joins the second electrode to the second conductive layer and is thicker than the second gold film of the second conductive layer; The inclination angle of the side surface on the side closer to the groove of the ridge waveguide is gentler than the inclination angle of the side surface on the side farther from the groove. 2. The semiconductor laser device according to claim 1, characterized in that: The melting point of the first alloy solder layer is lower than the melting point of the alloy of the first base metal film and gold; The melting point of the second alloy solder layer is lower than the melting point of the alloy of the second base metal film and gold. 3. semiconductor laser device as claimed in claim 1, is characterized in that: The thickness of the first laminate is substantially the same as the thickness of the second laminate. 4. semiconductor laser device as claimed in claim 1, is characterized in that: The above-mentioned second laminate has a ridge waveguide. 5. The semiconductor laser device according to any one of claims 1 to 4, characterized in that: The above-mentioned semiconductor substrate is composed of a zinc blende type crystal material, and has a main surface inclined with respect to the (100) crystal plane.

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