CN100505446C - semiconductor laser device - Google Patents

Abstract

The present invention provides a semiconductor laser device with a ridge waveguide that is excellent in polarization characteristics and easiness of mounting. In its outermost part on which the solder layer (61) is deposited, the incomplete adherent layer (31) is formed at least in the ridge structure (35). In bonding the semiconductor laser device (1) to the mount (62) via the solder layer (61), the incomplete adherent layer (31) is not adhered or adhered incompletely to the solder layer (61). On either side of the incomplete adherent layer (31) is formed the complete adherent layer (33).

Description

semiconductor laser device

technical field

The present invention relates to a semiconductor laser device used in, for example, an optical pickup in an optical disc system or the like.

Background technique

In the semiconductor laser device disclosed in Japanese Unexamined Patent Publication No. 9-64479, a rib-shaped waveguide is provided in the semiconductor substrate, so that the lower electrode of the laser is formed by the following three layers: the ohmic contact layer that is in ohmic contact with the protective layer, formed on the The non-alloyed metal layer on the surface of the ohmic contact layer is composed of a high-melting-point metal that does not alloy with the solder layer, and the surface of the non-alloyed metal layer is separated from the center line of the long-side direction of the light-emitting region 5 along the left-right direction. The alloyed electrode layer alloyed with the solder layer 8 formed in the region of the given distance above. The non-alloy layer and the solder layer in contact with it will not be alloyed, but the alloyed electrode and the solder layer will be alloyed, thereby bonding the semiconductor laser device to the heat sink.

In the semiconductor laser device disclosed in Japanese Unexamined Patent Publication No. 2004-14659, an active layer (active layer) and grooves located on both sides of the ridge structure are provided, and the electrode film is formed to include the ridge structure and the groove. surface and extend to its sides. A solder layer for bonding the semiconductor laser device to the mounting substrate is formed on both sides of the groove portion, thereby forming a space facing the ridge structure portion and the groove portion.

In the semiconductor laser device disclosed in JP-A-11-87849, the semiconductor laser device is bonded to the Si substrate via a solder layer, but an unsoldered cavity space is formed under the active layer.

In Japanese Patent Application Laid-Open No. 9-64479, in a semiconductor laser device having a rib-shaped waveguide, although the internal stress acting on the light-emitting region caused by the difference in thermal expansion rate between the heat sink and the semiconductor laser device can be reduced, thereby improving the semiconductor laser However, if it is applied to a semiconductor laser device with a ridge waveguide, the light emitting characteristics cannot be improved.

In Japanese Patent Laid-Open No. 2004-14659, it is necessary to form a solder layer to form a space facing the ridge structure and the groove, and the solder layer cannot be laminated over the entire surface of the semiconductor laser device. This has a problem that it is difficult to mount the semiconductor laser device on a sub mount.

In addition, in Japanese Patent Laid-Open No. 11-87849, it is also necessary to provide a cavity region in the solder layer formed when the semiconductor laser device is connected to the substrate, and the solder layer cannot spread over the entire surface of the semiconductor laser device. As a result of lamination, there is a problem that the semiconductor laser device is difficult to mount on the submount. .

Also, JP-A-9-64479 and JP-A-11-87849 do not disclose any structure for improving polarization characteristics in semiconductor laser devices having ridge waveguides that are more susceptible to stress than rib waveguides.

Contents of the invention

Accordingly, an object of the present invention is to provide a semiconductor laser device having a ridge waveguide with improved light emission characteristics, especially polarization characteristics, and easy mounting.

The present invention is a semiconductor laser device, which has a ridge-shaped structure part of a stripe-shaped ridge-shaped waveguide arranged on a semiconductor substrate. It is characterized in that the semiconductor laser device is bonded to the mounting part through a solder layer, and has:

An incomplete adhesive layer, which has electrical conductivity, is located on the outermost portion of the semiconductor laser device outside the above-mentioned ridge waveguide, the above-mentioned solder layer is laminated on the incomplete adhesive layer, and the incomplete adhesive layer is at least above the above-mentioned formed on the ridge structure and not fully adhered to the above-mentioned solder layer; and

The complete adhesive layer has electrical conductivity and is located on the outermost part of the semiconductor laser device than the above-mentioned ridge waveguide. The above-mentioned solder layer is laminated on the complete adhesive layer. The thickness direction and the direction perpendicular to the extending direction of the ridge waveguide are respectively formed on both sides of the incomplete adhesion layer and bonded to the solder layer.

According to the present invention, since the incomplete adhesive layer is formed, the incomplete adhesive layer is formed on the outermost portion of the semiconductor laser device on which the above-mentioned solder layer is laminated than the ridge waveguide, at least in the above-mentioned ridge structure portion. formed on the surface, has electrical conductivity and is incompletely bonded to the solder layer, and thus when the semiconductor laser device is mounted in the mounting part via the solder layer, the incompletely bonded layer does not bond to the solder layer or Complete condition bonded. Thus, the stress can be uniformly applied to the ridge structure part by the thermal expansion and thermal contraction of the solder layer, so that the difference caused by the thermal expansion and thermal contraction between the semiconductor laser device and the mounting part when the semiconductor laser device emits light can be reduced. The stress of the ridge-shaped structure portion can be reduced, and thus, the deformation generated in the ridge-shaped structure portion due to the application of stress can be alleviated. Reducing the deformation generated in the ridge structure can also reduce the stress applied to the active layer and suppress the deformation in the active layer, thereby improving the polarization characteristics of laser light. Improving the polarization characteristics of the laser refers to increasing the polarization ratio and reducing the polarization angle.

In addition, since the perfect bonding layer has electrical conductivity and is located on the outermost part of the semiconductor laser device than the ridge waveguide, the above-mentioned solder layer is laminated on the perfect bonding layer, and the perfect bonding layer has a thickness equal to that of the semiconductor substrate. direction and the direction perpendicular to the extending direction of the ridge waveguide are respectively formed on both sides of the incomplete adhesive layer, whereby the semiconductor laser device and the mounting part can be firmly mechanically connected.

In the outermost part on which the solder layer is laminated, the above-mentioned incomplete adhesion layer and the above-mentioned perfect adhesion layer are provided, and the solder layer is laminated thereon and the semiconductor laser device is mounted in the mounting part, whereby it is possible to spread over the outermost part. The solder layer is laminated on the entire surface of the laminated surface. Since the solder layer does not need to be processed, the semiconductor laser device can be easily mounted in the mounting part.

The present invention is characterized in that the above-mentioned incomplete adhesive layer comprises:

The first incomplete adhesive layer is formed in the center of the semiconductor laser device in a direction perpendicular to the thickness direction of the above-mentioned semiconductor substrate and the extending direction of the above-mentioned ridge waveguide; and

The second incomplete adhesion layer is formed on both sides of the first incomplete adhesion layer in a direction perpendicular to the thickness direction of the above-mentioned semiconductor substrate and the extending direction of the ridge waveguide, and is connected with the formation of the above-mentioned solder. The wettability between the solder materials of the layers is located between the wettability between the above-mentioned first incomplete adhesion layer and the solder material forming the above-mentioned solder layer and the wettability between the above-mentioned complete adhesion layer and the solder material forming the above-mentioned solder layer. in wetness.

According to the present invention, the first incomplete adhesion layer having poor wettability with the solder material forming the solder layer is formed on the portion of the incomplete adhesion layer close to the ridge structure. In the direction perpendicular to the thickness direction of the semiconductor substrate and the extending direction of the above-mentioned ridge waveguide, it is formed between the first incomplete adhesion layer and the complete adhesion layer: the wettability with the solder material forming the solder layer has the above-mentioned first A second incompletely bonded layer having properties between the incompletely bonded layer and the aforementioned fully bonded layer. As a result, the adhesive force between the uppermost surface portion of the laminated solder layer and the solder layer gradually increases as the distance from the ridge structure portion increases. By gradually changing the adhesive force, it is possible to suppress tension in the portion adjacent to the fully bonded layer and the incompletely bonded layer caused by the stress generated in the fully bonded layer and the stress generated in the incompletely bonded layer. The sharp stress change relaxes the stress applied to the ridge structure, thereby reducing the deformation generated in the ridge structure.

In addition, the present invention is characterized in that the first partial adhesion layer is formed of molybdenum (Mo), the second partial adhesion layer is formed of platinum (Pt), and the perfect adhesion layer is formed of gold (Au).

According to the present invention, the first partial adhesion layer is formed of molybdenum (Mo), the second partial adhesion layer is formed of platinum (Pt), and the perfect adhesion layer is formed of gold (Au), whereby the above effects can be achieved. In addition, film-forming techniques for forming Mo, Pt, and Au have been used in the past, so that forming a perfect adhesion layer and an incomplete adhesion layer does not require a new film-forming technique and can be easily formed.

In addition, the present invention is characterized in that, in a direction perpendicular to the thickness direction of the semiconductor substrate and the extending direction of the ridge waveguide, on both sides of the ridge waveguide, the ridge waveguide is separated from the ridge waveguide by a predetermined distance. A stepped portion is formed, and a concave portion is formed between the stepped portion and the ridge waveguide.

According to the present invention, when the semiconductor laser device is bonded to the sub-mount through the solder layer, it is necessary to press the semiconductor laser device to the sub-mount with a given load, but by providing a step portion, the step portion is perpendicular to the above-mentioned semiconductor substrate. In the direction of the thickness direction of the above-mentioned ridge-shaped waveguide and the direction of the extending direction of the above-mentioned ridge-shaped waveguide, it is formed on both sides of the above-mentioned ridge-shaped waveguide with a predetermined distance from the above-mentioned ridge-shaped waveguide. By distributing the above-mentioned load applied to the above-mentioned ridge structure to the step portion, the additional stress generated by pressing the ridge structure can be reduced, and therefore, the deformation of the ridge structure when it is installed in the mounting portion can be reduced. .

In addition, the present invention is characterized in that the partial adhesive layer is formed where the concave portion deviates from the ridge waveguide, and the perfect adhesive layer is formed where the concave portion deviates from the step portion.

According to the present invention, since the incomplete adhesive layer is formed where the concave portion deviates from the ridge waveguide, the stress applied to the ridge structure portion from around the ridge structure portion can be reduced. In the interface between the ridge structure and the solder layer, it is difficult to release the heat generated in the ridge structure by laser emission, but by forming a complete adhesive layer at the concave portion biased to the step portion 8, the generated heat can be made Heat is efficiently released from the fully bonded layer to the semiconducting layer.

In addition, the present invention is characterized in that the portion of the incomplete adhesive layer formed in the recess is formed so as to extend from the ridge waveguide over a predetermined range between the ridge waveguide and the step portion, and the predetermined range is the ridge waveguide. The distance between the shaped waveguide and the stepped portion is more than 30% and less than 50%.

According to the present invention, if the portion of the incompletely bonded layer formed in the concave portion, according to 30% or more of the distance between the ridge waveguide and the step portion from the ridge waveguide to the distance between the ridge waveguide and the step portion Formed within the range, the stress can be reduced more reliably. In addition, if the portion of the incomplete adhesive layer formed in the concave portion is within the range of 50% or more of the distance between the ridge waveguide and the step portion from the ridge waveguide to the distance between the ridge waveguide and the step portion If formed, the heat from the ridge structure is difficult to be released into the alloy layer, thereby deteriorating the current value characteristics of the semiconductor laser device, that is, reducing the luminous efficiency. Therefore, the portion of the incomplete adhesive layer formed in the concave portion is formed so as to extend from the ridge waveguide to a predetermined range between the ridge waveguide and the step portion between the ridge waveguide and the step portion. In the range of 30% or more and less than 50% of the distance, not only the stress added to the ridge waveguide can be reliably reduced, but also the deterioration of the current value characteristics of the semiconductor laser device can be suppressed.

In addition, the present invention is characterized in that the part of the above-mentioned complete bonding layer formed in the above-mentioned concave part is divided into 50% of the distance between the ridge waveguide and the step part from the step part to the distance between the ridge waveguide and the step part. % formed within the following range.

According to the present invention, the part formed in the recess in the fully bonded layer is formed in such a way that the step exceeds 50% of the distance between the ridge waveguide and the step between the ridge waveguide and the step. In this case, although the deterioration of the current value characteristics of the semiconductor laser device can be suppressed by the heat release effect from the complete adhesion layer to the solder layer, the stress generated in the complete adhesion layer is easily transmitted to the ridge structure. . Therefore, the portion formed in the concave portion in the complete bonding layer is formed so as to be within a range of 50% or less of the distance between the ridge waveguide and the step portion from the step portion to the distance between the ridge waveguide and the step portion. , it is possible to suppress the deterioration of the current value characteristics of the semiconductor laser device, and make it difficult for the stress generated in the perfect adhesion layer to be transmitted to the ridge structure portion, thereby suppressing the deformation generated in the ridge structure portion.

In addition, the present invention is characterized in that it has a base metal layer formed of gold (Au) and in which the above-mentioned perfect adhesion layer and the above-mentioned incomplete adhesion layer are laminated.

According to the present invention, the heat generated in the ridge structure part is transferred to the complete adhesion layer side through the base metal layer formed of gold (Au) with high thermal conductivity, thereby being released to the mounting part through the solder layer middle. Therefore, it is possible to eliminate the lack of heat release between the incomplete adhesion layer and the solder layer, further suppress deterioration of current characteristics, and thereby achieve a longer life of the semiconductor laser device.

In addition, the present invention is characterized in that it has a base metal layer in which the above-mentioned perfect adhesion layer and the above-mentioned incomplete adhesion layer are laminated;

The base metal layer is characterized in that a plating electrode layer made of gold (Au) and formed by electroplating, a first electrode layer made of a predetermined metal, and a second electrode made of gold (Au) are laminated in this order. formed in layers.

Since the plating electrode layer made of gold is formed by electroplating, a thicker layer can be formed in a shorter time than a layer made of gold formed by a sputtering method. However, since the plating electrode layer made of gold has poor surface flatness and wettability varies with plating conditions, there is a possibility of discrete variations in adhesion characteristics. According to the present invention, the base metal layer includes a plating electrode layer made of gold, but the plating electrode layer is sequentially laminated with a first electrode layer having a surface flatter than the plating electrode layer and formed of a predetermined metal, and The second electrode layer is made of gold. Thereby, the surface flatness of the second electrode layer made of gold can be improved. Therefore, it is possible to improve the adhesion properties between the perfect adhesion layer and the incomplete adhesion layer laminated on the second electrode layer, thereby suppressing the adhesion between the base metal layer and the complete adhesion layer and the incomplete adhesion layer. peel off. Therefore, the heat generated in the ridge structure part can be conducted to the side of the complete bonding layer through the base metal layer formed of gold (Au) with high thermal conductivity, and can be reliably released to the mounting part through the solder layer. middle. In this way, insufficient heat dissipation between the incomplete adhesion layer and the solder layer can be solved, and the deterioration of current characteristics can be further suppressed to achieve a longer life of the semiconductor laser device.

In addition, the present invention is characterized in that the predetermined metal forming the first electrode layer is selected from the group consisting of molybdenum (Mo), platinum (Pt), molybdenum platinum (MoPt), and titanium (Ti).

According to the present invention, the predetermined metal forming the first electrode layer is selected from the group consisting of molybdenum (Mo), platinum (Pt), molybdenum platinum (MoPt), and titanium (Ti). Molybdenum (Mo), platinum (Pt), molybdenum platinum (MoPt), and titanium (Ti) have excellent surface flatness when forming an electrode layer, and thus can achieve the above-mentioned effects.

In addition, the present invention is characterized in that the first and second electrode layers are formed continuously by sputtering.

According to the present invention, since the first and second electrode layers are continuously formed by sputtering, the adhesion to the plating electrode layer made of gold can be improved, and even if there are irregularities on the surface of the plating electrode layer, Since the first and second electrode layers are formed to fill up the unevenness, the thickness of the base electrode layer can be made as uniform as possible. By making the thickness of the base electrode layer more uniform, more stable bonding and improved adhesion can be obtained. As a result, insufficient heat dissipation can be eliminated, thereby further suppressing deterioration of current characteristics and prolonging the life of the semiconductor laser device.

In addition, the present invention is characterized in that the thickness of the base metal layer is selected to be 0.5 μm or more and less than 5.0 μm.

According to the present invention, if the thickness of the base metal layer is less than 0.5 μm, the heat transfer effect cannot be sufficiently achieved, and if it exceeds 5.0 μm, the stress generated by forming the base metal layer is transmitted to the ridge waveguide, thereby deforming the ridge waveguide. By setting the thickness of the base metal layer to 0.5 μm or more and less than 5.0 μm, not only sufficient heat transfer effect from the ridge waveguide to the incomplete bonding layer can be obtained, but also stress applied to the ridge waveguide can be reduced.

In addition, the present invention is characterized by having a back metal layer formed of gold on the surface portion of the semiconductor substrate opposite to the ridge structure portion so as to sandwich the semiconductor substrate.

According to the present invention, since there is a back metal layer formed of gold on the surface portion of the semiconductor substrate on the opposite side to the ridge structure portion so as to sandwich the semiconductor substrate, it is possible to relax the damage formed on the ridge structure portion side. The stress induced by the base metal layer.

Description of drawings

The purpose, features, and advantages of the present invention will become clearer from the following detailed description and accompanying drawings.

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

Fig. 2 is a plan view of a semiconductor laser device.

3A to 3C are cross-sectional views showing manufacturing steps of the semiconductor laser device.

4A to 4D are cross-sectional views showing manufacturing steps of the semiconductor laser device.

5A to 5C are cross-sectional views showing manufacturing steps of the semiconductor laser device.

6 is a cross-sectional view showing a semiconductor laser device in which a semiconductor laser device is mounted on a mounting portion via a solder layer.

7 is a cross-sectional view of a semiconductor laser device according to another embodiment of the present invention.

Fig. 8 is a plan view of the semiconductor laser device.

9 is a cross-sectional view showing a semiconductor laser device in which a semiconductor laser device is mounted on a mounting portion via a solder layer.

Fig. 10 is a cross-sectional view of a semiconductor laser device according to another embodiment of the present invention.

Fig. 11 is a cross-sectional view of a semiconductor laser device according to another embodiment of the present invention.

Detailed ways

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

FIG. 1 is a cross-sectional view of a semiconductor laser device 1 according to an embodiment of the present invention, and FIG. 2 is a plan view of the semiconductor laser device 1 . Fig. 1 is a sectional view viewed from the section line II-I in Fig. 2 . In addition, FIG. 2 shows a view viewed from the side where the ridge structure portion 35 is provided in the thickness direction Z of the semiconductor substrate 2 , in which the incomplete adhesion layer 31 is shown with oblique lines for ease of illustration. The semiconductor laser device 1 is a semiconductor laser chip. The thickness direction Z of the semiconductor substrate 2 is parallel to the lamination direction of each semiconductor layer and each metal layer forming the semiconductor laser device. The semiconductor laser device 1 has: a semiconductor substrate 2, a first plating layer 3, an active layer 4, a second plating layer 5, an etching stop layer 6, a ridge portion 7, a step portion 8, the first and second dielectric layers 17, 18, Base electrode layer 23 for plating, plating electrode layer 27 , metal layer 32 including imperfect adhesion layer 31 , and perfect adhesion layer 33 .

The semiconductor substrate 2 may be laminated with compound semiconductor layers, and is formed of n-type gallium arsenide (GaAs) in this embodiment. The surface of the semiconductor substrate 2 in the thickness direction Z is formed in a rectangular shape. The thickness of the semiconductor substrate 2 is selected to be, for example, 50 μm to 130 μm.

The first plated layer 3 is laminated on the one surface 2 a in the thickness direction Z of the semiconductor substrate 2 so as to cover the entire surface of the one surface 2 a. The first coating layer 3 is formed of n-type (Al _X Ga _1-X ) _Y In _1-Y P, where 0<X<1, 0<Y<1. In this embodiment, X=0.7 and Y=0.5 are selected, that is, the first plating layer 3 is formed of n-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P. The thickness of the first plating layer 3 is selected to be, for example, 2.0 μm.

。势垒层由(Al_0.7Ga_0.3)_0.5In_0.5P形成，其厚度例如选择为

。导向层由(Al_0.7Ga_0.3)_0.5In_0.5P形成，其厚度例如选择为

The active layer 4 is laminated on the one surface 3a in the thickness direction Z of the first plating layer so as to cover the entire surface of the one surface 3a. The active layer 4 has a quantum well structure, and includes: a first guide layer (guide layer) laminated on a surface 3a in the thickness direction Z of the first coating layer 3, a surface laminated in the thickness direction Z of the first guide layer The first well layer (well layer), the barrier layer formed on one surface in the thickness direction Z of the first well layer, the second well layer formed on one surface in the thickness direction Z of the barrier layer, and the second well layer formed in the 2. The second guide layer on one surface in the thickness direction Z of the well layer. The first and second well layers are formed of In _0.5 Ga _0.5 P, and their thickness is selected as

. The barrier layer is formed of (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P, and its thickness is selected as, for example,

. The guide layer is formed of (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P, and its thickness is selected as

The second plating layer 5 is laminated on the one surface 4 a in the thickness direction Z of the active layer 4 so as to cover the entire surface of the one surface 4 a. . The second plating layer 5 is formed of p-type (Al _X Ga _1-X ) _Y In _1-Y P, where 0<X<1, 0<Y<1. In this embodiment, X=0.7 and Y=0.5 are selected, that is, the second plating layer 5 is formed of p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P. The thickness of the second plating layer 5 is selected to be, for example, 0.2 to 0.3 μm.

。蚀刻停止层6防止第2镀层5被蚀刻。The etching stopper layer 6 is laminated on the one surface 5 a in the thickness direction Z of the second plating layer 5 so as to cover the entire surface of the one surface 5 a. Etching stop layer 6 is formed of p-type In _0.5 Ga _0.5 P. The thickness of etch stop layer 6 is selected as

. The etch stop layer 6 prevents the second plating layer 5 from being etched.

The ridge portion 7 includes a third plating layer 11 and a protective layer 12 . The ridge portion 7 is laminated on one surface 6 a in the thickness direction Z of the etching stop layer 6 . The ridge portion 7 protrudes from the one surface 6 a of the etching stop layer 6 toward one side in the thickness direction Z at the center portion in the width direction Y of the semiconductor laser device 1 . The semiconductor laser device 1 is formed substantially plane-symmetrically with respect to an imaginary plane passing through the center in the width direction Y and extending in parallel in the thickness direction Z. The ridge portion 7 extends in a direction perpendicular to the thickness direction Z and the width direction Y, that is, the emission direction of the laser light, and is formed in a stripe shape. The ridge 7 is formed so as to extend between both ends of the semiconductor laser device 1 in the direction X in which the ridge 7 extends, which is the direction in which the laser light is emitted.

The third plated layer 11 is laminated on one surface 6 a of the etching stopper layer 6 in the thickness direction Z. The third plating layer 11 is formed of p-type (Al _X Ga _1-X ) _Y In _1-Y P, where 0<X<1, 0<Y<1. In this embodiment, X=0.7 and Y=0.5 are selected, that is, the third plating layer 11 is formed of p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P. The thickness of the third plating layer 11 is selected to be, for example, 300 nm to 5000 nm. The third plating layer 11 forms a ridge waveguide for guiding laser light.

The protective layer 12 is laminated on one surface 11 a of the third plating layer 11 in the thickness direction Z. The protective layer 12 is formed of gallium arsenide (GaAs). The protective layer 12 is used to form an ohmic contact with the electrode layer 21 on the ridge described later.

The ridge portion 7 is formed to have a predetermined dimension L1 in the width direction Y, and the predetermined dimension is selected to be 1.5 μm to 3.0 μm. One end of the ridge 7 in the thickness direction Z, that is, the dimension of the width direction Y of the end of the side away from the semiconductor substrate 2 is selected to be 0.1 μm to 0.3 μm, and the other end of the thickness direction Z is the same as the etching stop layer 6. The dimension of the contact end portion in the width direction Y is selected to be 1.5 μm to 3.0 μm, so that a cross section perpendicular to the extending direction X of the ridge portion 7 is formed into a trapezoid with the semiconductor substrate 2 side as the bottom.

The stepped portion 8 includes a first stepped structure layer 13 and a second stepped structure layer 14 . The step portion 8 is formed on both sides of the ridge portion 7, that is, on both sides of the ridge waveguide in the width direction Y, so as to be separated from the ridge portion 7 by a predetermined distance L2. A concave portion 15 extending in the extending direction X of the ridge portion 7 is formed therebetween. The aforementioned predetermined distance L2 is selected to be approximately 10 μm to 20 μm. The step portion 8 extends parallel to the extending direction X of the ridge portion 7 and is formed in a stripe shape. The stepped portion 8 is formed so as to extend from a position separated by a predetermined distance L2 from the ridge portion 7 in the width direction Y to the end portion of the semiconductor laser device 1 .

The first stepped structure layer 13 is laminated on one surface 6a of the etching stopper layer 6 in the thickness direction Z, and is made of the same material as the third plating layer 11 and has the same thickness. The second stepped structure layer 14 is laminated over the entire surface of one surface 13 a in the thickness direction Z of the first stepped structure layer 13 , is made of the same material as the protective layer 12 , and has the same thickness. That is, the thickness of the ridge portion 7 and the thickness of the step portion 8 are formed to be equal. By providing the step portion 8, the mechanical damage to the ridge portion 7 can be alleviated when the semiconductor laser device 1 precursor is formed in the manufacturing process of the semiconductor laser device 1, and when the semiconductor laser device 1 is mounted. .

The side surface 7 b of the ridge portion 7 facing the step portion 8 is covered with a first dielectric layer 17 . The first dielectric layer 17 extends from the side surface 7b of the ridge portion 7 along the width direction Y toward the step portion 8 for a predetermined distance L3, covers the contact portion between the third plating layer 11 and the etching stop layer 6, and is also laminated on the etching stop layer 6. on one surface 6a in the thickness direction Z.

One surface 8 a of the step portion 8 in the thickness direction Z and a side surface 8 b facing the ridge portion 7 are covered with the second dielectric layer 18 . The second dielectric layer 18 extends from the side surface 8b of the stepped portion 8 along the width direction Y toward the ridge portion 7 for a predetermined distance L4, covers the contact portion between the third plating layer 11 and the etching stop layer 6, and is also laminated on the etching stop layer 6. on one surface 6a in the thickness direction Z.

～3000

。The 1st and the 2nd dielectric layer 17,18 are formed by SiO ₂ , and its thickness is selected as 1000

~3000

.

On one surface of the ridge portion 7 in the thickness direction Z, that is, one surface 12a of the protective layer 12 in the thickness direction Z, the ridge upper electrode layer 21 is laminated over the entire surface. The upper ridge electrode layer 21 is made of AuZn, and is formed by alloying in a nitrogen atmosphere. The ridge upper electrode layer 21 is formed in a trapezoidal shape with the semiconductor substrate 2 side as the lower base in a cross section perpendicular to the extending direction X of the ridge portion 7 .

。第2电镀用基底层25由金(Au)形成，层积在第1电镀用基底层24的厚度方向Z的一表面24a上。电镀用基底电极层23设置得为了在制造工艺中通过电镀形成后述的电镀电极层27。第2电镀用基底层25的厚度，例如选择为 On the first and second dielectric layers 17, 18, the ridge upper electrode layer 21, and the portion exposed from between the first and second dielectric layers 17, 18 on one surface 6a of the thickness direction Z of the etching stop layer 6, A base electrode layer 23 for plating is laminated. The plating base electrode layer 23 is composed of a first plating base layer 24 and a second plating base layer 25 . The first base layer 24 for electroplating is formed of titanium (Ti) to be laminated on the first and second dielectric layers 17, 18, the ridge upper electrode layer 21, and the one surface 6a in the thickness direction Z of the etching stop layer 6. The exposed portion between the first and second dielectric layers 17 and 18 is formed. The thickness of the base layer 24 for the first electroplating is, for example, selected as

. The second base layer 25 for electroplating is formed of gold (Au), and is laminated on one surface 24 a in the thickness direction Z of the first base layer 24 for electroplating. The plating base electrode layer 23 is provided in order to form a plating electrode layer 27 described later by plating in the manufacturing process. The thickness of the 2nd electroplating base layer 25 is, for example, selected as

The part where the first electroplating base layer 24 is in contact with the etching stop layer 6 becomes a light absorber, thus in the vicinity of the ridge portion 7, the first electroplating base layer 24 and the etching stop layer 6 are provided between the first electroplating base layer 24 and the etching stop layer 6. 1 dielectric layer 17, it is possible to prevent light from being absorbed. The aforementioned predetermined distance L3 is selected to be 3 μm to 7 μm, and L4 is also selected to be 3 μm to 7 μm. Regarding L3, if it is less than 3μm, the luminous efficiency will drop, and if it exceeds 7μm, the far-field pattern (Far Filed Pattern: FFP) improvement effect will be lost. Regarding the predetermined distance L4, if the distance L4 is less than 3 μm, the dielectric film layer is not provided on the side of the step portion, so the FFP improvement effect is lost, and if it exceeds 7 μm, the FFP improvement effect is also lost. By disposing a light absorber between the ridge portion 7 and the step portion 8, the far field pattern (FFP) and ripple can be improved, that is, the disorder of the FFP can be suppressed and the ripple of the laser can be reduced.

On one surface 23 a of the base electrode layer 23 for plating in the thickness direction Z, a plating electrode layer 27 is stacked over the entire surface. The plating electrode layer 27 is a base metal layer and is formed of gold (Au). The thickness of the plating electrode layer 27 is selected to be not less than 0.5 μm and less than 5.0 μm.

On one surface 27 a of the plating electrode layer 27 in the thickness direction Z, a metal layer 32 including an incomplete adhesion layer 31 is laminated. Metal layer 32 is formed of, for example, molybdenum (Mo). The incomplete adhesion layer 31 therefore has electrical conductivity. The thickness of the metal layer 32 is selected to be 0.05 μm˜0.30 μm.

The incomplete adhesion layer 31 is formed to include at least a portion of the metal layer 32 formed on the ridge structure portion 35 . The incomplete adhesive layer 31 is formed on at least the ridge structure portion 35 on the outermost portion of the ridge waveguide layer on the outermost portion of the ridge waveguide. on the mounting part 62 of the

The ridge structure part 35 includes: the above-mentioned ridge part 7 in the semiconductor laser 1; the first ridge-shaped laminated part 41 laminated on the ridge part 7 in the first dielectric layer 17; the electrode layer 21 on the ridge; Use the second ridge-shaped laminated part 42 laminated on the ridge portion 7 through the first dielectric layer 17 or the ridge upper electrode layer 21 in the base electrode layer 23; the third ridge-shaped laminated portion 43 on the ridge-shaped laminated portion 42 ; and the fourth ridge-shaped laminated portion 44 laminated on the third ridge-shaped laminated portion 43 in the metal layer 32 . That is, the ridge structure portion 35 is a portion stacked on one surface 6a of the etching stop layer 6 in the thickness direction Z in the width direction Y of the semiconductor laser device 1, and the portion of the ridge portion 7 on the etching stop layer 6 side The range between both ends is the range indicated by the arrow L1 in FIG. 1 .

The incomplete adhesive layer 31 is also formed where the above-mentioned concave portion 15 deviates toward the ridge waveguide. The portion of the incomplete adhesive layer 31 formed in the recess 15 is formed so as to extend a predetermined distance L5 from the ridge 7 between the ridge waveguide, that is, the ridge 7 and the step 8 . The predetermined distance L5 is selected to be more than 30% and less than 50% of the distance L2 between the ridge portion 7 and the step portion 8 .

The incomplete adhesive layer 31 is formed in the extending direction X of the ridge portion 7 so as to spread over the two ends of the semiconductor laser device 1, thereby leaving a predetermined distance from the two ends of the semiconductor laser device 1, that is, the outgoing surface. The way L6 is formed. The aforementioned predetermined distance L6 is selected so that a coating film for preventing damage to the exit end face can be formed in the exit surface of the semiconductor laser device 1 . By selecting the aforementioned predetermined distance L6 as above, damage to the aforementioned coating film formed in the semiconductor laser device 1 can be prevented.

On one surface 32 a in the thickness direction Z of the metal layer 32 , a perfect adhesion layer 33 is laminated except for the part constituting the above-mentioned incomplete adhesion layer 31 . The complete adhesion layer 33 is formed of gold (Au). The thickness of the fully bonded layer 33 is selected to be 0.1 μm to 0.4 μm, preferably approximately 0.12 μm. The perfect bonding layer 33 is closer to the outside than the ridge waveguide, and is formed on both sides of the incomplete bonding layer 31 in the width direction Y of the outermost portion on which the above-mentioned solder layer 61 is laminated, and extends to the edge of the semiconductor laser device 1. end in the width direction Y.

A complete adhesive layer 33 is formed on the concave portion 15 offset to the step portion 8 . The portion of the complete adhesive layer 33 formed in the concave portion 15 is formed so as to extend over a predetermined distance L7 from the step portion 8 between the ridge portion 7 and the step portion 8 . The predetermined distance L7 is selected to be 50% or less of the predetermined distance L2 between the ridge portion 7 and the step portion 8 .

的厚度。On the other surface in the thickness direction Z of the semiconductor substrate 2, a back metal layer 36 as a back metal layer is formed. The back metal layer 36 is laminated over the entire surface of the other surface 2 b in the thickness direction Z of the semiconductor substrate 2 . The back metal layer 36 is formed of gold (Au). The thickness of the back metal layer 36 is different from that of the electroplating electrode layer 27, and is selected as

thickness of.

的蚀刻停止层6、用于形成第3镀层11及第1台阶结构层13的由p型(Al_0.7Ga_0.3)_0.5In_0.5P构成的第1先驱体层51、用于形成保护层12及第2台阶结构层14的第2先驱体层52。在有源层4中，将第1及第2阱层的厚度分别设为

，将势垒层的厚度设为

第1及第2导向层的厚度分别设为

3A to 3C , FIGS. 4A to 4D , and FIGS. 5A to 5C are cross-sectional views showing manufacturing steps of the semiconductor laser device 1 . First, as shown in FIG. 3A , on a surface 50a of a precursor 50 of a semiconductor substrate 2 with a thickness of 300 μm to 350 μm, epitaxy using a molecular beam epitaxy (abbreviated as MBE) device or an organic metal chemical vapor deposition (abbreviated as MOCVD) device The growth method is sequentially stacked in the following order: the first coating layer 3 with a thickness of 2.0 μm, the active layer 4, the second coating layer 5 with a thickness of 0.2 μm to 0.3 μm, the thickness

The etch stop layer 6, the first precursor layer 51 composed of p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P for forming the third plating layer 11 and the first step structure layer 13, and the first precursor layer 51 for forming the protective layer 12 and The second precursor layer 52 of the second stepped structure layer 14 . In the active layer 4, the thicknesses of the first and second well layers are set to

, set the thickness of the barrier layer to

The thicknesses of the first and second guide layers are set as

Next, parts of the first precursor layer 51 and the second precursor layer 52 are removed using photolithography and etching techniques, and as shown in FIG. 3B , the aforementioned ridge portion 7 and step portion 8 are formed.

Next, cover the ridge portion 7 and the step portion 8 and a surface 6a in the thickness direction Z of the etching stop layer 6, after laminating the dielectric layer, use photolithography technology and etching technology to remove the layered layer on the ridge in the dielectric layer. The part on the part 7 and part of the part on the etching stop layer 6 are laminated, thereby forming the first and second dielectric layers 17 and 18.

Then, the first and second dielectric layers 17, 18, the portions exposed from the first and second dielectric layers 17, 18, and the ridge portion 7 of one surface 6a in the thickness direction Z of the etching stop layer 6 are covered. One surface 7a in the thickness direction Z, after coating the resist, use photolithography and etching to remove the part of the resist layered on the one surface 7a in the thickness direction Z of the ridge portion 7, as shown in the figure 3C, a resist layer 53 is thus formed.

～3000

的由AuZn构成的第3先驱体层，然后通过剥离(1ift—off)法将第3先驱体层中除层积在脊形部7上的部位外的部分与抗蚀图层53一起去除。由此，如图4A所示，脊上电极层21就形成在保护层12的厚度方向Z的一表面12a上。Next, a film thickness of 400 is deposited so as to cover one surface 7a of the ridge portion 7 in the thickness direction Z and the resist layer 53.

~3000

The third precursor layer made of AuZn, and then the part of the third precursor layer except the part laminated on the ridge part 7 is removed together with the resist layer 53 by a lift-off method. Thus, as shown in FIG. 4A , the ridge upper electrode layer 21 is formed on one surface 12 a in the thickness direction Z of the protective layer 12 .

Next, as shown in FIG. 4B , the thickness of the semiconductor substrate is ground to the thickness of the semiconductor substrate 2 . That is, the other surface of the precursor 50 in the thickness direction Z of the semiconductor substrate 2 is ground to form a semiconductor substrate 2 with a thickness of 50 μm to 130 μm.

Next, as shown in FIG. 4C , on the other surface 2 b in the thickness direction Z of the semiconductor substrate 2 , a back electrode layer 36 is formed, whereby the ridge upper electrode layer 21 and the back electrode layer 36 are alloyed in a nitrogen atmosphere.

的方式蒸镀并层积，从而形成第1电镀用基底层24，此后，进一步将Au以层厚

的方式蒸镀，从而形成第2电镀用基底层25。由此，形成电镀用基底电极层23。Next, from the one surface 2a side of the semiconductor substrate 2, as shown in FIG.

The method is evaporated and laminated to form the first base layer 24 for electroplating. After that, Au is further added with a layer thickness

By evaporation, the second base layer 25 for electroplating is formed. Thus, base electrode layer 23 for plating is formed.

Next, by supplying electric power to the plating base electrode layer 23 and performing electrolytic Au plating for a predetermined time, as shown in FIG. 4D , the plating electrode layer 23 having a layer thickness of 0.5 to less than 5.0 μm is formed.

Next, on one surface 23a in the thickness direction Z of the plating electrode layer 23, a metal layer 32 is formed as shown in FIG. Au is evaporated to form the fourth precursor layer 57 .

Next, after coating a resist on one surface 57a in the thickness direction Z of the fourth precursor layer 57, the resist laminated on the metal layer 32 in the fourth precursor layer 57 is removed using photolithography and etching techniques. A part of the etchant is removed to expose a part of the metal layer 32 that should be the part of the incompletely bonded layer 31, thereby forming a resist layer 58 as shown in FIG. 5B. The mask width created by the resist layer 58 , that is, the dimension in the width direction Y of the metal layer 32 exposed from the resist layer 58 is about 20 μm. That is, the metal layer 32 is exposed to one side and the other side of the width direction Y by about 10 μm from a virtual plane passing through the center of the ridge portion 7 and perpendicular to the width direction Y. In addition, both end portions of the metal layer 32 in the extending direction X of the ridge portion 7 are covered with a resist layer 58 .

Next, the fourth precursor layer 57 exposed from the resist layer 58 is removed by an etching technique to expose a part of the metal layer 32 . This exposed portion of the metal layer 32 forms the incompletely bonded layer 31 . In addition, by removing part of the fourth precursor layer 57 and further removing the resist layer 58 , perfect adhesion layers 33 are formed on both sides of the incomplete adhesion layer 31 in the width direction Y as shown in FIG. 5C .

6 is a cross-sectional view showing the semiconductor laser device 60 after the semiconductor laser device 1 is mounted on the mounting portion 62 via the solder layer 61 . The semiconductor laser device 1 is mounted in the mounting portion 62 by die-bonding by laminating the solder layer 61 on the above-mentioned incomplete adhesion layer 31 and perfect adhesion layer 33 . The solder material constituting the solder layer 61 is made of AuSn, and in this embodiment, Au contains 70% and Sn contains 30%. The mounting portion 62 is a so-called sub-mount, and is formed of a material having high electrical conductivity and thermal conductivity such as aluminum nitride (AlN), for example.

The semiconductor laser device 1 is die-bonded to the mounting portion 62 under given die-bonding conditions. The die bonding conditions include conditions of load applied when the semiconductor laser device 1 is mounted in the mounting portion 62 , and heating conditions applied when the semiconductor laser device 1 is mounted in the mounting portion 62 .

A physical load is necessary for crimping the semiconductor laser device 1 on the solder layer 61 on the mounting portion 62, but if a heavier load such as 1.0N (Newton) is applied, the internal structure of the semiconductor laser device 1 is ridge-shaped. The structure portion 35 and the first and second dielectric layers 17 and 18 are excessively stressed, thereby deforming the ridge structure portion 35 due to stress, and in the worst case, destroying the semiconductor laser device 1 . Conversely, if a light load such as 0.05N is applied, the semiconductor laser device 1 cannot be bonded to the solder layer 61 on the mounting portion 62 due to insufficient pressure, thereby causing peeling. Therefore, the above-mentioned load condition is selected to be greater than 0.05N and less than 1.0N. Preferably, a lighter load range is used instead of a heavy load range, for example, 0.1N-0.3N.

In addition, in order to melt the solder layer 61 on the mounting portion 62, thereby forming a complete bonding layer 33 made of Au in an alloyed manner on the outermost surface of the die bonding surface of the semiconductor laser device 1, it is necessary to place the mounting portion 62 on the surface. Heating in a heater, if the amount of heating is large, for example, after heating at 360°C (degrees) for 30s (seconds), and then using a blower to forcibly cool to about 200°C in 1 second, the semiconductor laser device 1 Delamination, separation, changes in physical properties, and alloy formation of each layer due to differences in thermal expansion coefficients in the internal laminated structure generate stress and cause deformation. Conversely, if the amount of heating is small, for example, after heating at 280° C. for 0.3 seconds and then forcibly cooling to about 200° C. in 1 second using a blower, no alloy will be formed, and the semiconductor laser device 1 cannot be bonded to In the solder layer 61 on the mounting portion 62, this causes peeling. Therefore, for the above heating conditions, the heating temperature is selected to be greater than 200°C and less than 360°C, and the heating time is selected to be longer than 0.3 seconds and less than 30 seconds. In addition, because the conditions in the area with less heating amount are favorable, the heating condition is set to 300°C. ℃ for about 2s.

The above-mentioned temperature conditions are largely influenced by the thickness of the uppermost complete bonding layer 33 located on the side of the die bonding surface of the semiconductor laser device 1. Therefore, in a region with a small amount of heating (about 2s at 300° C.) Advantageously, the thickness of the incomplete adhesion layer 31 is reduced, for example, to 0.12 μm, and the alloy is formed in a short time.

The alloy reaction of AuSn, which is the solder material constituting the solder layer 61, and Au of the perfect adhesion layer 33, that is, the alloying of AuSn and Au of the perfect adhesion layer 33, starts by heating under the state of being pressed by a load. The flow of AuSn reacting with Au and alloying is: AuSn is melted by heating, and the melted AuSn is attached to the surface of the perfect adhesion layer 33, whereby AuSn is diffused to the surface of the perfect adhesion layer 33 by direct heating. internal. Diffusion direction is to carry out toward the thickness direction of complete adhesive layer 33, but begins to diffuse from several points on the surface of complete adhesive layer 33, if continue to heat, then the diffusion point that is positioned at several places not only increases and this point just from point-like Expand into a circle. The depth and speed of diffusion of AuSn to the thickness direction Z of the complete adhesion layer 33 are determined by the ratio of the absolute amount of the solder material AuSn to the Au forming the complete adhesion layer 33, that is, the mass ratio and the amount of heating. Time is the same. Therefore, when the amount of solder material is large, the amount of Au in the perfect bonding layer 33 is small, and the amount of heating is large, the perfect bonding layer 33 is alloyed only by instantaneous contact with AuSn, thereby By forming the outermost complete bonding layer 33 on the die bonding surface side of the semiconductor laser device 1 as before, a large amount of solder material is provided, and the heating is stopped when AuSn starts to diffuse, thereby stopping the diffusion.

On the outermost surface of one side of the thickness direction Z of the semiconductor substrate 2 of the semiconductor laser device 1, on the ridge structure portion 35, an incomplete adhesion layer 31 made of Mo is formed, and since Au itself disappears, although AuSn The constituted solder material is in close contact with the incomplete adhesion layer 31, but no alloy is formed. Alloy formation with the solder material AuSn laminated on the mounting portion 62 occurs only on the entire surface of the complete adhesion layer 33 . The adhesion of the incomplete adhesive layer 31 and the solder layer 61 is not complete, thus, the incomplete adhesive layer 31 is more resistant to soldering when the semiconductor laser device 1 is mounted on the mounting portion 62 than the complete adhesive layer 33 . Layer 61 receives less stress.

In the semiconductor laser device 60, when the semiconductor laser device 1 is mounted on the mounting portion 62, the solder material is deposited over the entire surface of one surface in the thickness direction of the semiconductor laser device 1, thereby being different from the case where the solder material is partially deposited. than, the installation is easier.

A semiconductor laser device 60 using the semiconductor laser device 1 of the present invention (hereinafter also referred to as the semiconductor laser device of Embodiment 1) was produced, and a semiconductor laser device using the semiconductor laser device of the comparative example (hereinafter also referred to as the semiconductor laser device of the comparative example) was produced. semiconductor laser device) to measure polarization properties. The structure of the semiconductor laser device of the comparative example is such that an alloy formation layer made of Au is formed on the entire surface of one surface 32 a of the metal layer 32 in the thickness direction Z of the semiconductor laser device 1 . This alloy forming layer is formed to have the same thickness as the complete adhesion layer 33 .

When actually fabricating these semiconductor laser devices 1 and the semiconductor laser device of the comparative example, one wafer made of p-type GaAs was prepared, and after forming the fourth precursor layer as shown in FIG. 5A , the wafer was divided into two. One of the divided wafers was used to form a plurality of semiconductor laser devices 1 having incomplete electrode layers 31 through the above-mentioned steps, and the other was used to form a plurality of semiconductor laser devices of comparative examples.

The formed semiconductor laser device 1 and the semiconductor laser device of the comparative example were all soldered to the mounting portion 62 with a solder material under the above-mentioned die bonding conditions. Each semiconductor laser device mounted on the mounting portion 62 is mounted on a 5.6φ stem, that is, a stem with a diameter of 5.6mm, using Ag paste, and is manufactured through processes such as wire bonding and cap sealing. An aging test was carried out on the manufactured semiconductor laser device under the same conditions, and the measured polarization characteristics of the laser are shown in Table 1. The polarization ratio and polarization angle were measured as polarization characteristics.

【Table 1】

Polarization characteristics Example 1 comparative example Polarization ratio (Ave) 343 174 Polarization ratio (σ) 79 112 Polarization angle (Ave) 1.6 —2.1 Polarization angle (σ) 1.1 3.5

Regarding the polarization ratio, the average value (Ave) and the standard deviation (σ) of 30 semiconductor laser devices were measured. Regarding the polarization angle, the average value (Ave) and the standard deviation (σ) of 30 semiconductor laser devices were measured. Polarization angle means that when a polarization filter in a certain direction is arranged in parallel with respect to the emission of laser light and the polarization filter is shifted by an angle of 90°, the light power received by the light receiving part through the polarization filter becomes the maximum Angle.

As shown in Table 1, compared with the semiconductor laser device of Comparative Example, the semiconductor laser device of Example 1 has a larger polarization ratio and a smaller polarization angle, and the dispersion deviation of both the polarization ratio and the polarization angle is also smaller. In the semiconductor laser device of the comparative example, when the semiconductor laser device is mounted on the submount under the above-mentioned die bonding conditions, the alloy formation layer made of Au located on the outermost surface on the die bonding surface side is formed in contact with the submount on the submount. AuSn performs alloy formation. In the semiconductor laser device of the comparative example, the alloying is also reliably carried out at the outermost portion of the ridge structure portion 35, so the Iop (rated current) at high temperature does not rise and is relatively stable, but the laser light at normal temperature In characteristic measurement, in a plurality of semiconductor laser devices having the same structure, Ave (average value) of the polarization ratio is low, and the dispersion width of σ (standard deviation) of the polarization ratio increases. In addition, Ave of the polarization angle is shifted to the negative side, and the dispersion deviation width of σ of the polarization angle is increased. The reason is that when the solder material diffused from the outside to the ridge structure portion 35 forms an alloy with the alloy formation layer positioned at the outermost portion of the semiconductor laser device, the ridge structure portion 35 is alloyed while the ridge portion 7 is covered by AuSn. , since the stress is added after the alloy is formed, deformation occurs. The stress that becomes the source of this deformation is presumed to be a mixed force of pressure and tension on the ridge structure portion 35 when the alloy formation layer made of Au and the solder material made of AuSn are alloyed.

In addition, the surface portion of the ridge structure portion 35 has an alloy formation layer made of Au, and as its base layer, a metal layer 32 made of Mo, a plating electrode layer 27 made of Au, and a base electrode layer 23 for plating are formed. However, the stress received by the alloy forming layer and the solder material after alloying is presumed to affect the base layer as well, and it is presumed that the stress and the tension act together. It is presumed that the pressure among the above stresses is generated when the solder material is heated and expanded, and the tension is presumed to be generated when the solder material is cooled after heating. Therefore, when the solder material expands to a certain extent, contacts the ridge structure portion 35 to a certain extent, and shrinks to a certain extent, a uniform stress acts on the ridge structure portion 35, whereby the occurrence of deformation can be reduced. In the form close to the bare chip state, the semiconductor laser device can be bonded on the submount. However, in actuality, when the solder material expands and contracts, it does not expand and contract to a certain degree, but expands and contracts partially and indefinitely. Therefore, a relatively high pressure portion and a relatively small pressure portion are locally generated in the ridge structure portion 35 during heating, and alloy formation also proceeds locally, whereby stress is locally generated. In the case where alloy formation is performed locally and heating is stopped and cooling is started, the solder material starts to shrink at this time, thereby locally adding large and small tensions and large and small pressures to the ridge structure portion 35 . part. At this time, the contraction tension and pressure are presumed to be forces that apply stress to the ridge structure portion 35 . In addition, during cooling, the alloy-forming layer formed on the outermost portion of the ridge structure portion 35 reacts with the solder material, and the AuSn layer formed by the alloy shrinks. AuSn is a kind of solder material, but in the temperature range of 300°C to 400°C where AuSn is heated to join, it is difficult to form an alloy with the base layer, that is, the metal layer 32 made of Mo, and instead changes to the peeling direction, and because Since the alloyed layer and the metal layer 32 are laminated by sputtering, in the semiconductor laser device of the comparative example, it is presumed that the alloyed alloyed layer stretches the metal layer 32 to increase the stress on the metal layer 32 . In this way, in the semiconductor laser device of the comparative example, stress is applied to the metal layer 32 to cause deformation. From this, it can be estimated that the stress also spreads to the base layer, and finally the stress acts on the ridge portion 7 of the most important ridge structure portion 35. So far, the ridge portion 7 is deformed. Therefore, it is very important to uniformly apply stress to the ridge structure 35 to reduce deformation because the laser characteristics will be deteriorated if the stress is not uniformly applied to the ridge structure portion 35 . The cause of the uneven stress applied to the ridge structure portion 35 is presumed to be that the outermost portion of the ridge structure portion 35 is formed of an AuSn alloy. That is, it is presumed that if alloy formation is not performed on the outermost portion of the ridge structure portion 35, the stress becomes uniform to reduce deformation, and thus the laser characteristics should not be deteriorated.

By measuring the polarization characteristics of the semiconductor laser devices of Example 1 and Comparative Example, the deformation of the ridge structure portion 35 can be reduced according to the way the stress acts on the ridge structure portion 35, thereby improving the polarization characteristics.

In addition, in the semiconductor laser device 60 of Example 1, when observing its actual cross section, it can also be confirmed that the solder material composed of AuSn on the mounting portion 62 reacts with the complete adhesion layer 33 to form an alloy. The complete bonding layer 31 does not undergo alloying reaction, that is, AuSn does not become an alloy if it does not react with the incomplete bonding layer 31 .

As described above, in the semiconductor laser device 60 using the semiconductor laser device 1, it is possible to improve the polarization ratio of the measurement items of the laser polarization characteristics in the assembled state and to suppress the dispersion of the polarization ratio, and to reduce the polarization angle. In addition, the dispersion of the polarization angle is improved. By increasing the polarization ratio, the stability of the light output of the semiconductor laser device 60 can be achieved. In addition, by reducing the polarization angle and improving the dispersion of the polarization angle, it is possible to improve the power variation of the FFP radiation characteristic, and to reduce the radiation noise of the emitted laser light.

In addition, perfect adhesion layers 33 are respectively formed on both sides of the incomplete adhesion layer 31 in the width direction Y of the semiconductor laser device 60 , so that the semiconductor laser device 1 and the mounting portion 62 can be firmly mechanically connected.

In addition, in the semiconductor laser device 60 , the recess 15 is offset from the ridge structure 35 and the incomplete adhesion layer 31 is formed, so that the stress applied to the ridge structure 35 from the periphery of the ridge structure 35 can be further reduced. In the interface between the ridge structure part 35 and the solder layer 61, it is difficult to release the heat generated in the ridge structure part 35 due to the emission of laser light, so by forming the complete adhesion layer 33 at the place where the concave part 15 deviates to the step part 8, it is possible to The generated heat can be efficiently released from the perfect adhesion layer 33 to the mounting portion 62 via the solder layer 61 .

In addition, in the semiconductor laser device 60, the stress can be more reliably reduced by selecting the above-mentioned predetermined distance L5 to be 30% or more of the predetermined distance L2 between the ridge portion 7 and the step portion 8, so that the above-mentioned predetermined distance L5 is set to If it is less than 50% of the predetermined distance L2, the heat from the ridge waveguide is difficult to be released into the solder layer, so that the deterioration of the current value characteristic of the semiconductor laser device can be suppressed.

In addition, in the semiconductor laser device 60, selecting the above-mentioned predetermined distance L7 to be 50% or less of the predetermined distance makes it difficult for the stress generated in the complete adhesion layer 33 to be transmitted to the ridge structure portion 35, thereby further reducing the ridge structure. The deformation produced in the shape structure part 35.

In addition, between the ridge portion 7 and the step portion 8 in the semiconductor laser device 1, the first plating base layer 24 made of Ti is in contact with the etching stop layer 6 formed by epitaxial growth. Current does not flow in the part where the plating base layer 24 is in contact with the etching stopper layer 6 , and the ridge upper electrode layer 21 as an ohmic electrode is formed so as to be laminated only on the ridge portion 7 . The first electroplating base layer 24 and the etching stop layer 6 do not form a low-resistance ohmic contact, so that the current can be concentrated only in the ridge portion 7 formed with the ohmic contact by the ridge upper electrode layer 21 and the protective layer 12. way flow.

In addition, in the semiconductor laser device 60, the portion immediately below the luminous point, that is, the portion from the luminous point toward the mounting portion 62 in the thickness direction Z and its vicinity is not alloyed with the solder layer 61, and heat in this portion is released (heat release) is lowered. In the semiconductor laser device 60, a small cavity is formed between the side surface of the ridge structure 35 and the solder layer 61, and the top of the ridge structure 35 is in close contact with the solder layer 61, so no cavity is formed in this portion. . Here, the top of the ridge structure portion 35 refers to a portion of the ridge structure portion 35 that is stacked on one surface 7 a in the thickness direction Z of the ridge portion 7 . In addition, the side surface of the ridge structure part 35 is the remaining part of the ridge structure part 35 except the end part of the above-mentioned ridge structure part 35 . Even if the top of the ridge structure part 35 (right below the ridge waveguide) is not alloyed with the solder material, due to the presence of the solder layer 61, there will be a gap from the incomplete adhesion layer 31 to the mounting part 62 via the solder layer 61. Heat Conduction. However, it is not enough to utilize only the heat radiation from the top of the ridge structure portion 35, so by increasing the thickness of the plating electrode layer 27 made of Au, it is possible to reduce the heat generation of the ridge structure portion 35 from the high thermal conductivity. The plated electrode layer 27 formed of gold (Au) transfers to the stepped portion 8 , thereby bypassing the thermal conduction path, and releasing it to the mounting portion 62 through the solder layer 61 . This eliminates insufficient heat release between the incomplete adhesion layer 61 and the solder layer 61 , thereby further improving current characteristics.

In addition, when the thickness of the plating electrode layer 27 is less than 0.5 μm, the heat transfer effect cannot be fully realized, and if it exceeds 5.0 μm, the wafer will warp when the metal layer is formed on the wafer, thereby deteriorating the yield. , and forming the plating electrode layer 27 causes stress in the ridge structure portion, whereby the ridge waveguide deforms. Therefore, by setting the thickness of the plating electrode layer 27 to 0.5 μm or more and 5.0 μm or less, not only can a sufficient heat conduction effect be obtained from the ridge structure portion 35 to the complete adhesion layer 33, but also the stress applied to the ridge structure portion 35 can be reduced. , thereby increasing the yield.

In the case where the plating electrode layer 27 is reacted with a solder material such as AuSn for alloying, or when the semiconductor laser device 1 is mounted in the mounting portion 62 by soldering in a portion close to the ridge structure portion 35, heating is performed. , the laser characteristics may be deteriorated, but as mentioned above, by setting the incomplete adhesion layer 31 and the complete adhesion layer 33, the incomplete adhesion layer 31 does not react with the solder material, that is, it is possible to prevent the electrode from being plated. The alloying of the layer 27 protects the plating electrode layer 27 and removes the heat applied from the ridge portion 7 through the solder, thereby maintaining good laser characteristics.

In the embodiment of the present invention, Mo is used as the material for forming the incomplete adhesion layer 31, but as the material for forming the incomplete adhesion layer 31, it is used as long as it does not form an alloy with the metal forming the solder material under the above-mentioned die bonding conditions. materials.

Furthermore, in another embodiment of the present invention, in the above-mentioned embodiment, the incomplete adhesion layer 31 may be formed of a metal that has an Wetting is low. Such a metal material includes, for example, platinum (Pt).

Table 2 shows the polarization characteristics of the semiconductor laser device in which the incomplete adhesive layer 31 is formed of platinum (Pt) (hereinafter sometimes referred to as the semiconductor laser device of Example 2). The manufacturing conditions were the same as those of the semiconductor laser device of Embodiment 1 above, except that the material forming the incomplete adhesion layer 31 was replaced.

【Table 1】

Polarization characteristics Example 2

Polarization ratio (Ave) 235 Polarization ratio (σ) 86 Polarization angle (Ave) —1.4 Polarization angle (σ) 1.4

Although the semiconductor laser device of Example 2 is not as effective as the semiconductor laser device of Example 1 in which the incomplete adhesive layer 31 is formed of Mo, it is found that a remarkable effect is obtained compared with the semiconductor laser device of Comparative Example. Therefore, Pt is considered to be an effective metal as a material for forming the incomplete adhesion layer 31 .

A metal that undergoes a rapid alloying reaction in a short time, that is, a metal that reacts to form an alloy in a short time, may have a bad influence on the polarization characteristics of a semiconductor laser device, but it is presumed that a metal that undergoes a slow alloying reaction is difficult to alloy in a short time Metals, or metals that do not undergo an alloy reaction, that is, metals that do not react to form an alloy, do not or hardly exert a bad influence on the polarization characteristics of laser light. Therefore, the incomplete adhesion layer 31 is formed of a metal that slowly undergoes an alloy reaction or a metal that does not undergo an alloy reaction, and such metals include Ti and the like in addition to the aforementioned Mo and Pt. These Mo, Pt, and Ti have higher melting points than Au, and have lower wettability with solder material AuSn than Au.

7 is a cross-sectional view of a semiconductor laser device 100 according to another embodiment of the present invention, and FIG. 8 is a plan view of the semiconductor laser device 100 . Fig. 7 is a cross-sectional view taken along line VII-VII of Fig. 8 . In addition, FIG. 8 shows a view from the side where the ridge structure portion 35 is provided in the thickness direction Z of the semiconductor substrate 2. In the figure, in order to facilitate the illustration of the first and second incomplete adhesion layers 31a, 31b, oblique labels are marked. line to represent.

In the semiconductor laser device 100, in the semiconductor laser device 1 of the above-mentioned embodiment shown in FIG. It is the same as the semiconductor laser device 1, and thus the same reference numerals are given to the same parts, and repeated explanations are omitted.

In the semiconductor laser device 100, the intermediate metal layer 102 including the second incomplete adhesion layer 31b is formed between the metal layer 32 and the perfect adhesion layer 33 in the semiconductor laser device 1 described above. The intermediate metal layer 102 is stacked on one surface 32 a of the metal layer 32 in the thickness direction Z. The intermediate metal layer 102 is stacked on the metal layer 32 so as to extend from a position separated by a predetermined distance L8 from the ridge structure portion 35 in the width direction Y to an end in the width direction Y. The predetermined distance L8 is selected to be greater than or equal to 30% and less than 50% of the predetermined distance L2.

On one surface 102 a of the intermediate metal layer 102 in the thickness direction Z, a complete adhesion layer 33 is laminated. The complete adhesion layer 33 is laminated on the intermediate metal layer 102 so as to extend from a position separated by a predetermined distance L5 from the ridge structure portion 35 to the end in the width direction Y.

The portion of the metal layer 32 exposed from the intermediate metal layer 102 constitutes the first incomplete adhesion layer 31a, and the portion of the intermediate metal layer 102 exposed from the complete adhesion layer 33 constitutes the second incomplete adhesion layer 31b. In the outermost portion facing the solder layer 61 when the semiconductor laser device 1 is mounted in the mounting portion 62, a first incomplete adhesion layer 31a is formed in the center in the width direction Y, and both sides of the first incomplete adhesion layer 31a are respectively The second incomplete adhesion layer 31b is formed.

The intermediate metal layer 102 is formed of a metal whose wettability with the solder material forming the solder layer 61 has properties between the above-mentioned metal layer 32 and the complete adhesion layer 33, that is, better than the metal forming the metal layer 32. It is easy to wet with solder material, and is poorer than the metal forming the fully bonded layer 33, that is, difficult to wet with solder material. In the present embodiment, the metal layer 32 is formed of Mo, and the complete bonding layer 33 is formed of Au, whereby the intermediate metal layer 102 is formed of, for example, platinum (Pt). The metal forming the intermediate metal layer 102 has a melting point lower than that of the metal forming the metal layer 32 and higher than that of the metal forming the complete adhesion layer 33 .

～3000

。The intermediate metal layer 102 is formed by vapor deposition, and its thickness is selected as 100

~3000

.

The first and second incomplete adhesive layers 31a, 31b are formed so as to extend between both ends of the semiconductor laser device 100 in the extending direction X of the ridge portion 7, whereby Both end faces, that is, the emitting faces are formed so as to be separated by a predetermined distance L6. The aforementioned predetermined distance L6 is selected so that a coating film for preventing damage to the exit end face can be formed on the exit surface of the semiconductor laser device 100 . .

9 is a cross-sectional view showing a semiconductor laser device 160 in which a semiconductor laser device 100 is mounted on a mounting portion 62 via a solder layer 61 . The semiconductor laser device 100 is bonded to the mounting portion 62 via the solder layer 61 made of AuSn under the above-mentioned die bonding conditions. The complete adhesive layer 33 is alloyed with the solder material, and part of the second incomplete adhesive layer 31b is also alloyed with the solder material, but the second incomplete adhesive layer 31b is formed between the solder material forming the solder layer 61. Wettability has the property between the first incomplete adhesion layer 31a and the complete adhesion layer 33, so the adhesion force between the second incomplete adhesion layer 31b and the solder layer 61 is greater than that of the first incomplete adhesion layer 31b. The adhesive force between the adhesive layer 31 a and the solder layer 61 is smaller than the adhesive force between the complete adhesive layer 33 and the solder layer 61 .

Accordingly, the adhesive force between the uppermost surface portion on which the solder layer 61 is laminated and the solder layer 61 increases as the distance from the ridge structure portion 35 in the width direction Y increases. By gradually changing the adhesive force as the distance from the ridge structure portion 35 in the width direction Y, the stress generated in the fully bonded layer 33 and the stress generated in the incompletely bonded layers 31a, 31b can be suppressed. The induced sudden stress change in the portion of the complete adhesive layer 33 adjacent to the incomplete adhesive layers 31a, 31b thereby relaxes the stress applied to the ridge structure portion 35 and further reduces the deformation generated in the ridge structure portion 35 .

In addition, since the film-forming technology of forming Mo, Pt, and Au has been used until now, the first incomplete adhesion layer 31a is formed of molybdenum (Mo), and the second incomplete adhesion layer 31b is formed of platinum (Pt). The complete adhesion layer 33 is formed of gold (Au) to form the first and second partial adhesion layers 31a, 31b and the complete adhesion layer 33, so that a new film forming technique is not required, and thus it can be easily formed. .

FIG. 10 is a cross-sectional view of a semiconductor laser device 110 according to another embodiment of the present invention. The semiconductor laser device 110 of this embodiment has the same structure as the semiconductor laser device 1 of the embodiment shown in FIG. Repeat instructions.

The semiconductor laser device 110 has: a semiconductor substrate 2, a first plating layer 3, an active layer 4, a second plating layer 5, an etching stop layer 6, a ridge portion 7, a step portion 8, the first and second dielectric layers 17, 18, Base electrode layer 23 for plating, base metal layer 112 , metal layer 32 including imperfect adhesion layer 31 , and perfect adhesion layer 33 .

The base metal layer 112 has a plating electrode layer 113 , a first electrode layer 114 , and a second electrode layer 115 . The base metal layer 112 is formed by sequentially stacking the plating electrode layer 113 , the first electrode layer 114 , and the second electrode layer 115 . The thickness of the base metal layer 112 is selected to be greater than or equal to 0.5 μm and less than 5.0 μm.

The plating electrode layer 113 has the same structure as the above-mentioned plating electrode layer 27 and is formed by the same method. The plating electrode layer 113 is laminated on the one surface 23 a in the thickness direction Z of the plating base electrode layer 23 so as to cover the entire surface. The thickness of the plating electrode layer 113 is selected to be greater than or equal to 0.5 μm and less than 5.0 μm, for example, 1 μm.

The first electrode layer 114 is formed over the entire surface on one surface 113 a of the plating electrode layer 113 in the thickness direction Z. The first electrode layer 114 has an excellent surface flatness compared with the plating electrode layer 113 and is formed of a predetermined metal. The predetermined metal is selected from the group consisting of molybdenum (Mo), platinum (Pt), molybdenum platinum (MoPt), and titanium (Ti). By forming the first electrode layer 114 with these metals, the first electrode layer 114 having excellent surface flatness can be formed. When the first electrode layer 114 is formed of, for example, molybdenum (Mo), its thickness is selected to be not less than 0.05 μm and less than 0.30 μm, for example, 0.05 μm. The first electrode layer 114 is formed by sputtering.

On one surface 114a of the first electrode layer 114 in the thickness direction Z, the second electrode layer 115 is formed over the entire surface. The second electrode layer 115 is formed of gold. The thickness of the second electrode layer 115 is selected to be 0.05 μm or more and less than 1.0 μm, for example, 0.12 μm. On one surface 115 a in the thickness direction Z of the second electrode layer 115 , the metal layer 32 including the incomplete adhesion layer 31 is laminated over the entire surface. By forming the second electrode layer 115 from gold, the adhesion property between the base metal layer 112 and the incomplete adhesion layer 31 can be improved, thereby making it difficult to peel off. In addition, after the second electrode layer 115 is formed by the sputtering method similarly to the first electrode layer 114, it is formed into a film continuously. The second electrode layer 115 and the first electrode layer 114 are formed by successively forming a Mo film and an Au film in a state where the wafer is placed in one sputtering apparatus. Conventionally, after forming the Mo film, it was necessary to remove the wafer from the device and place the wafer again in another device to form the Au film. However, in this embodiment, when the wafer is not removed from the device, Next, two samples (Mo and Au) were placed in the apparatus, and a Mo film (first electrode layer 114) and an Au film (second electrode layer 115) were formed in this order. Accordingly, the second electrode layer 115 and the first electrode layer 114 can be continuously formed into films without breaking the vacuum, that is, without temporarily exposing the wafer to the atmosphere. Thereby, the surface of the first electrode layer 114 made of Mo is not oxidized, and there is no possibility of impairing the adhesion with the second electrode layer 115 made of laminated Au.

The thicknesses of the electroplating electrode layer 113, the first electrode layer 114, and the second electrode layer 115 are preferably 1 μm for the electroplating electrode layer 113 (Au), 0.05 μm for the first electrode layer 114 (Mo), and 0.05 μm for the second electrode layer. 115 (Au) is 0.12 μm.

Since the plating electrode layer 113 made of gold is formed by electroplating, it is possible to form a thicker layer in a shorter time than forming a layer made of gold by a sputtering method. However, the surface flatness of the plating electrode layer 113 is poor, and the wettability varies with plating conditions, so there is a possibility of discrete variations in adhesion characteristics. According to the present invention, the first electrode layer 114 and the second electrode layer 115 are sequentially laminated on the plating electrode layer 113 . The first electrode layer 114 has an excellent surface flatness compared with the above-mentioned plating electrode layer 113 and is formed of a predetermined metal. Thereby, the surface flatness of the second electrode layer 115 can be improved. Therefore, the adhesion property with the incomplete adhesion layer 31 laminated on the second electrode layer 115 can be improved, thereby suppressing the peeling between the base metal layer 112 and the incomplete adhesion layer 31 .

The semiconductor laser device 110 is mounted in the mounting portion 62 via the solder layer 61 in the same manner as the semiconductor laser device 100 described above, whereby a semiconductor laser device is fabricated. In the semiconductor laser device 110 of the present embodiment, peeling of the base metal layer 112 and the incomplete adhesion layer 31 can be suppressed, so the heat generated in the ridge structure portion 35 can be mediated by gold (Au) containing high thermal conductivity. The base metal layer 112 formed in such a manner conducts to the side of the complete adhesion layer 33 so that it can be reliably released into the mounting portion 62 via the solder layer 61 . Thereby, the lack of heat dissipation between the incomplete adhesion layer 31 and the solder layer 61 can be solved, and the deterioration of the current characteristics can be further suppressed to achieve a longer life of the semiconductor laser device 110 .

In addition, the first and second electrode layers 114, 115 are formed in a continuous film-forming manner by sputtering, thereby improving the adhesion to the plating electrode layer 113, and even if there are irregularities in the surface 113a of the plating electrode layer 113, Since the first and second electrode layers 114 and 115 are formed to fill up the unevenness, the thickness of the base metal layer 112 can be made as uniform as possible. By making the thickness of the base electrode layer 112 more uniform, more stable bonding and improved adhesion can be obtained. As a result, insufficient heat dissipation can be eliminated, thereby further suppressing deterioration of current characteristics and prolonging the life of the semiconductor laser device.

FIG. 11 is a cross-sectional view of a semiconductor laser device 120 according to another embodiment of the present invention. The semiconductor laser device 120 of this embodiment has the same structure as the semiconductor laser device 100 of the embodiment shown in FIG. base electrode layer 112. By employing such a configuration, in addition to the effects of the semiconductor laser device 100 described above, the same effects as those of the semiconductor laser device 120 can be obtained.

In the semiconductor laser device of another embodiment of the present invention, in the semiconductor laser device of each of the above-mentioned embodiments, the second plating layer 5, the ridge portion 7, and the step portion may be formed without the etching stop layer 6. 12 is integrally formed by the same semiconductor material, that is, the semiconductor material for forming the aforementioned second and third plating layers 5, 11, and forms a plating layer stacked on one surface 4a of the active layer 4 in the thickness direction Z. With such a configuration, stress from the outside is easily applied to the ridge waveguide, but even with such a configuration, since the stress is relieved by the above-mentioned incomplete adhesive layer 31, the same effect as that of the above-mentioned embodiment can be achieved. Since the number of epitaxial growth steps is reduced, the manufacturing time can be shortened, thereby improving productivity.

The present invention can also be carried out in other various forms without departing from its main spirit or main characteristics. Therefore, the above-mentioned embodiment is merely an illustration in all points, and the scope of the present invention is shown by the scope of the claim, and is not limited at all by this specification. Furthermore, modifications and changes belonging to the scope of the claims are included in the scope of the present invention.

Claims (12)

1. a semiconductor laser device (1,100,110,120) has the ridge structure portion (35) of the ridge waveguide that is arranged on the striated on the semiconductor substrate (2), it is characterized in that:

This semiconductor laser device is situated between bonding by soldering-tin layer (61) and installation portion (62),

Comprise:

Incomplete adhesive layer (31), it has electrical conductance, be positioned at surface portion than the semiconductor laser device in the more close outside of above-mentioned ridge waveguide, not exclusively adhesive layer (31) is gone up lamination above-mentioned soldering-tin layer (61), not exclusively adhesive layer (31) is gone up in above-mentioned ridge structure portion (35) at least and is formed, and not exclusively bonding with above-mentioned soldering-tin layer (61); And

Complete adhesive layer (33), it has electrical conductance, and be positioned at surface portion than the semiconductor laser device in the more close outside of above-mentioned ridge waveguide, adhesive layer (33) is gone up lamination fully above-mentioned soldering-tin layer (61), fully adhesive layer (33) is on the direction vertical with the bearing of trend of the thickness direction of above-mentioned semiconductor substrate (2) and above-mentioned ridge waveguide, form in the both sides of above-mentioned incomplete adhesive layer (31) respectively, and bonding with above-mentioned soldering-tin layer (61)

Above-mentioned incomplete adhesive layer (31) comprising:

The 1st incomplete adhesive layer (31a), it forms in the central authorities of semiconductor laser device on the direction vertical with the bearing of trend of the thickness direction of above-mentioned semiconductor substrate (2) and above-mentioned ridge waveguide; And

The 2nd incomplete adhesive layer (31b), it is on the direction vertical with the bearing of trend of the thickness direction of above-mentioned semiconductor substrate (2) and above-mentioned ridge waveguide, form in the both sides of the above-mentioned the 1st incomplete adhesive layer (31a) respectively, and and form wettability between the soldering tin material of above-mentioned soldering-tin layer (61) and be positioned among the wettability and the wettability between the soldering tin material above-mentioned complete adhesive layer (33) and the above-mentioned soldering-tin layer of formation (61) between the soldering tin material the above-mentioned the 1st incomplete adhesive layer (31a) and that form above-mentioned soldering-tin layer (61).

2. semiconductor laser device as claimed in claim 1 (100) is characterized in that:

The above-mentioned the 1st incomplete adhesive layer (31a) is formed by molybdenum;

The above-mentioned the 2nd incomplete adhesive layer (31b) is formed by platinum;

Above-mentioned complete adhesive layer (33) is formed by gold.

3. semiconductor laser device as claimed in claim 1 (1,100,110,120) is characterized in that:

On the direction vertical with the bearing of trend of the thickness direction of above-mentioned semiconductor substrate (2) and above-mentioned ridge waveguide, both sides at above-mentioned ridge waveguide, forming stage portion (8), and between this stage portion (8) and ridge waveguide, form recess (15) from above-mentioned ridge waveguide mode spaced apart by a predetermined distance.

4. semiconductor laser device as claimed in claim 3 (1,100,110,120) is characterized in that:

Above-mentioned recess (15) deflection ridge waveguide place is formed with above-mentioned incomplete adhesive layer (31);

Above-mentioned recess (15) deflection stage portion place is formed with above-mentioned complete adhesive layer (33).

5. semiconductor laser device as claimed in claim 4 (1,100,110,120) is characterized in that:

Be formed on part in the above-mentioned recess (15) in the above-mentioned incomplete adhesive layer (31), form according to the mode that between ridge waveguide and stage portion (8), spreads all over prescribed limit from ridge waveguide, this prescribed limit be between ridge waveguide and the stage portion (8) distance more than 30% and discontented 50% scope.

6. semiconductor laser device as claimed in claim 4 (1,100,110,120) is characterized in that:

Be formed on part in the above-mentioned recess (15) in the above-mentioned complete adhesive layer (33), according to forming in the scope below 50% of the distance ridge waveguide and the stage portion (8) by stage portion (8) between ridge waveguide and the stage portion (8).

7. semiconductor laser device as claimed in claim 1 (1,100) is characterized in that:

Have substrate metal layer, it is formed by gold and lamination has above-mentioned complete adhesive layer (33) and above-mentioned incomplete adhesive layer (31).

8. semiconductor laser device as claimed in claim 1 (110,120) is characterized in that:

Having lamination has the substrate metal layer of above-mentioned complete adhesive layer (33) and above-mentioned incomplete adhesive layer (31);

Above-mentioned substrate metal layer is made of gold and the mode of the 2nd electrode layer (115) that forms by the 1st electrode layer (114) electroplating the electroplated electrode layer (113) that forms, formed by the metal of being scheduled to and by gold forms according to lamination in turn.

9. semiconductor laser device as claimed in claim 8 (110,120) is characterized in that:

Form the predetermined metal of above-mentioned the 1st electrode layer (114), from the group that constitutes by molybdenum, platinum, molybdenum platinum and titanium, select.

10. semiconductor laser device as claimed in claim 9 (110,120) is characterized in that:

The the above-mentioned the 1st and the 2nd electrode layer (114,115) forms in the continuous film forming mode by sputtering method.

11., it is characterized in that as claim 7 or 8 described semiconductor laser devices (1,100,110,120):

The thickness of above-mentioned substrate metal layer is chosen as the above and discontented 5.0 μ m of 0.5 μ m.

12., it is characterized in that having as claim 7 or 8 described semiconductor laser devices (1,100,110,120):

Metal layer on back, its with the mode of the above-mentioned semiconductor substrate of clamping (2) with the surface element of the above-mentioned semiconductor substrate (2) of above-mentioned ridge structure portion opposition side on form by gold.

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