JP2012151182A - Semiconductor laser device and optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser device which inhibits the increase of the operation voltage of a semiconductor laser element due to heat applied to a current passage part during fusion bonding even when a junction down system is adopted.SOLUTION: A semiconductor laser device 100 includes a heat radiation base part 1 and a blue-violet semiconductor laser element 2 joined to the heat radiation base part 1 through a solder layer 12 and including an active layer 22 and a ridge part 23a. The solder layer 12 is disposed in a region B that does not correspond to the ridge part 23a, and a lower surface 26a of a p-side pad electrode 26 of the blue-violet semiconductor laser element 2 is joined to the heat radiation base part 1 through solder layers 12a and 12b disposed in the region B that does not correspond to the ridge part 23a.

Description

  The present invention relates to a semiconductor laser device and an optical device, and more particularly to a semiconductor laser device and an optical device in which a semiconductor laser element is bonded to a heat dissipation base through a fusion layer.

  2. Description of the Related Art Conventionally, there is known a semiconductor laser device in which a semiconductor laser element is bonded to a heat dissipation base through a fusion layer (for example, see Patent Document 1).

  In the above-mentioned Patent Document 1, a heat sink (heat radiation base) for releasing heat, and a sapphire substrate, an n-type layer, an active layer having a light emitting region, and a p-type layer are laminated in this order. A laser device including a laser element (semiconductor laser element) is disclosed. In the laser device of this laser device, a ridge portion (current path portion) is formed on the p-type layer, and a p-electrode (p-side ohmic electrode) is formed on the upper surface of the ridge portion. Further, in the laser device, the sapphire substrate side of the laser element and the heat sink are bonded via a conductive adhesive (fusion layer). That is, in the laser device described in Patent Document 1, the laser element is bonded to the upper surface of the heat sink by a so-called junction up method. That is, the p-electrode formed on the upper surface of the ridge portion is disposed at a position separated from the conductive adhesive.

  However, when a laser element is bonded to the upper surface of the heat sink by the junction-up method, heat generated at the time of emission of the laser element is caused by the presence of a thick sapphire substrate between the active layer of the laser element and the heat sink. There is an inconvenience that it is difficult to dissipate heat. For this reason, there is an inconvenience that the active layer of the laser element is deteriorated by the accumulated heat and the life of the laser element is shortened.

  Therefore, in order to easily dissipate the heat generated at the time of emission of the semiconductor laser element (laser element), the junction down method of joining the active layer side (ridge side) of the semiconductor laser element to the heat dissipation base part (heat sink), It is considered that a semiconductor laser element is bonded to the upper surface of the heat dissipation base. In general, in the junction down method, the semiconductor laser element is bonded to the heat radiation base part via the pad electrode disposed on the active layer side (ridge side) of the semiconductor laser element via the fusion layer. The

Japanese Patent No. 4288947

  However, in the junction down method, the ridge portion of the semiconductor laser element is disposed closer to the fusion layer than in the junction up method, so that the active layer side (ridge portion side) of the semiconductor laser element and the heat dissipation base portion At the time of bonding with a fusion layer (at the time of fusion), heat for melting the fusion layer is easily applied to the ridge portion of the semiconductor laser element. In this case, there arises a disadvantage that damage due to heat is applied to the ohmic electrode formed in the ridge portion. In addition, there arises a disadvantage that the stress caused by the strain of the fusion layer, which is generated due to the thermal history during fusion, is applied to the ohmic electrode of the ridge portion of the semiconductor laser element after fusion. As a result, there is a problem that the ohmic property of the ohmic electrode formed on the surface of the ridge portion (current passage portion) is deteriorated and the operating voltage of the semiconductor laser device is increased. This problem is significant in a blue-violet semiconductor laser device having a current path portion and an ohmic electrode that are easily affected by heat.

  The present invention has been made to solve the above-described problems, and one object of the present invention is due to the heat applied to the current passage portion at the time of fusion even when the junction down method is adopted. An object of the present invention is to provide a semiconductor laser device and an optical device capable of suppressing an increase in operating voltage of a semiconductor laser element.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, a semiconductor laser device according to a first aspect of the present invention includes a heat dissipation base, and a semiconductor that is joined to the heat dissipation base via a fusion layer and includes an active layer and a current passage. And the fusion layer is disposed in a region excluding the region corresponding to the current passage portion, and the surface on the active layer side of the semiconductor laser element is in a region excluding the region corresponding to the current passage portion. It is joined to the heat dissipating base part via the arranged fusion layer.

  In the semiconductor laser device according to the first aspect of the present invention, as described above, the surface on the active layer side of the semiconductor laser element is interposed via the fusion layer disposed in the region excluding the region corresponding to the current path portion. Since the fusion layer is not disposed in the region corresponding to the current passage portion by joining to the heat dissipation base portion, in the region corresponding to the current passage portion, the heat damage and the fusion caused by the heat are caused during fusion. Almost no stress due to distortion of the layer is generated. Thereby, even when the junction down method is adopted, it is possible to suppress the ohmic property of the ohmic electrode formed in the current passage portion from being deteriorated due to the heat applied to the current passage portion. As a result, an increase in operating voltage of the semiconductor laser element can be suppressed. The present invention is particularly effective when assembling a blue-violet semiconductor laser device having a current path portion and an ohmic electrode that are easily affected by heat by a junction-down method.

  In the semiconductor laser device according to the first aspect, preferably, in a region corresponding to the current passage portion, between the surface on the active layer side of the semiconductor laser element and the surface of the heat dissipation base portion facing the semiconductor laser element. A space is formed, and the surface of the semiconductor laser element and the surface of the heat dissipation base are joined in a region excluding the region corresponding to the current path portion. According to this structure, nothing is arranged on the surface on the active layer side of the semiconductor laser element in the region corresponding to the current path portion, so that the current path portion of the semiconductor laser element is caused by heat damage and heat. It can suppress more that the stress by the distortion | strain of a melt | fusion layer is applied.

  In this case, preferably, the heat radiating base portion includes a heat radiating base and an electrode formed on a surface of the heat radiating base facing the semiconductor laser element and supplying power to the semiconductor laser element. By being formed in a region excluding the region corresponding to the current path portion, a gap is formed between the surface of the semiconductor laser element and the surface of the heat dissipation base in the region corresponding to the current path portion. If comprised in this way, the length of the space | gap of the height direction of a semiconductor laser element between the surface of a semiconductor laser element and the surface of a thermal radiation base part can be enlarged by the thickness of an electrode at least. Thereby, a space | gap can be ensured between the surface of a semiconductor laser element and the surface of a thermal radiation base part reliably.

  In the semiconductor laser device in which the electrode is formed in a region other than the region corresponding to the current passage portion, preferably, the heat dissipation base has a recess provided on the surface facing the semiconductor laser element of the heat dissipation base, The electrode is formed in a region excluding the region corresponding to the current path portion, and the recess is formed in the region corresponding to the current path portion, so that the space between the surface of the semiconductor laser element and the bottom surface of the recess of the heat dissipation base is formed. Gaps are formed in the. With this configuration, not only the thickness of the electrode but also the distance in the depth direction of the recess, a gap in the height direction of the semiconductor laser element between the surface of the semiconductor laser element and the bottom surface of the recess of the heat dissipation base portion. Can be increased in length. Thereby, a space | gap can be ensured more reliably between the surface of a semiconductor laser element and the surface of a thermal radiation base part.

  In the semiconductor laser device according to the first aspect, it is preferable that the surface of the semiconductor laser element and the heat dissipation be between the surface on the active layer side of the semiconductor laser element and the surface of the heat dissipation base facing the semiconductor laser element. A wall portion is arranged to prevent the melted fusion layer from flowing into a region corresponding to the current passage portion when joining to the surface of the base portion. If comprised in this way, it can suppress reliably that a fusion | melting layer reaches | attains the surface of a semiconductor laser element by a fusion | melting layer flowing into the area | region corresponding to an electric current path part at the time of a fusion | melting by a wall part. . Thereby, it is possible to effectively suppress the stress caused by the heat damage and the distortion of the fusion layer caused by the heat to the current path portion of the semiconductor laser element.

  An optical device according to a second aspect of the present invention includes a heat dissipation base portion, a semiconductor laser element joined to the heat dissipation base portion via a fusion layer and having an active layer and a current passage portion, and includes a fusion layer. Is disposed in a region excluding the region corresponding to the current path portion, and the surface on the active layer side of the semiconductor laser element is interposed via a fusion layer disposed in the region excluding the region corresponding to the current path portion. A semiconductor laser device joined to the heat radiation base and an optical system for controlling the emitted light of the semiconductor laser device.

  In the optical device according to the second aspect of the present invention, as described above, the surface on the active layer side of the semiconductor laser element is radiated through the fusion layer disposed in the region excluding the region corresponding to the current path portion. Since the fusion layer is not disposed in the region corresponding to the current passage portion by bonding to the base portion, in the region corresponding to the current passage portion, the heat damage at the time of fusion and the fusion caused by the heat are caused. Almost no stress due to layer distortion is generated. Thereby, even when the junction down method is adopted in the semiconductor laser device, it is possible to suppress the ohmic property of the ohmic electrode formed in the current path portion from being deteriorated due to the heat applied to the current path portion. . As a result, it is possible to obtain an optical device including a semiconductor laser device including a semiconductor laser element in which an increase in operating voltage is suppressed.

1 is a top view showing a structure of a semiconductor laser device according to a first embodiment of the present invention. It is the front view seen from the emitting direction of the laser beam in the semiconductor laser device by a 1st embodiment of the present invention. 1 is an enlarged sectional view showing a detailed structure of a semiconductor laser device according to a first embodiment of the present invention. It is a front view for demonstrating the manufacturing process of the semiconductor laser apparatus by 1st Embodiment of this invention. It is the front view seen from the radiation | emission direction of the laser beam in the semiconductor laser apparatus by 2nd Embodiment of this invention. It is the expanded sectional view which showed the detailed structure of the semiconductor laser apparatus by 2nd Embodiment of this invention. It is the front view seen from the emitting direction of the laser beam in the semiconductor laser device by a 3rd embodiment of the present invention. It is the expanded sectional view which showed the detailed structure of the semiconductor laser apparatus by 3rd Embodiment of this invention. It is a front view for demonstrating the manufacturing process of the semiconductor laser apparatus by 3rd Embodiment of this invention. It is the top view which showed the structure of the semiconductor laser apparatus by 4th Embodiment of this invention. It is the front view seen from the emitting direction of the laser beam in the semiconductor laser device by a 4th embodiment of the present invention. It is the expanded sectional view which showed the detailed structure of the semiconductor laser apparatus by 4th Embodiment of this invention. It is the front view seen from the radiation | emission direction of the laser beam in the 3 wavelength semiconductor laser apparatus by 5th Embodiment of this invention. It is the schematic which showed the structure of the optical pick-up apparatus by 6th Embodiment of this invention. It is the front view seen from the emitting direction of the laser beam in the semiconductor laser device by the modification of 1st Embodiment of this invention.

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

(First embodiment)
First, the structure of the semiconductor laser device 100 according to the first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the semiconductor laser device 100 according to the first embodiment of the present invention is disposed on the heat radiating base portion 1 and the upper surface (the Z1 side surface, see FIG. 2) side of the heat radiating base portion 1. A blue-violet semiconductor laser device 2 having an oscillation wavelength of about 405 nm and a base portion 3 that supports the heat radiation base portion 1 from below (Z2 side, see FIG. 2) are provided. The base portion 3 is joined to the lower surface (the surface on the Z2 side) of the heat dissipation base 10 of the heat dissipation base portion 1 via the fusion layer 3a, and is connected to a negative electrode terminal (not shown). The blue-violet semiconductor laser element 2 is an example of the “semiconductor laser element” in the present invention.

  The blue-violet semiconductor laser element 2 has a width W1 of about 100 μm in a direction (X direction) orthogonal to the direction in which the resonator extends, and emits laser light from an end portion (resonator surface) on the Y1 side. It is configured as follows. Further, in the blue-violet semiconductor laser element 2, as shown in FIG. 2, an n-type cladding layer 21 made of n-type AlGaN is formed on the lower surface (Z2 side) of the n-type GaN substrate 20. On the lower surface of the n-type cladding layer 21, there is an active having a multiple quantum well (MQW) structure in which quantum well layers (not shown) made of InGaN and barrier layers (not shown) made of GaN are alternately stacked. Layer 22 is formed. A p-type cladding layer 23 made of p-type AlGaN is formed on the lower surface of the active layer 22.

  A ridge portion 23a extending along the direction in which the resonator extends (Y direction, see FIG. 1) is formed at the approximate center in the X direction of the p-type cladding layer 23. The ridge portion 23a is formed in a convex shape protruding downward (Z2 side). Further, as shown in FIG. 3, the active layer 22 located in the region A corresponding to the ridge portion 23a is configured to be a light emitting region 22a from which laser light is emitted. The region A corresponding to the ridge portion 23a is a region including the ridge portion 23a and the periphery of the ridge portion 23a in the X1 direction and the X2 direction and extending in the Z direction. The ridge portion 23a is an example of the “current path portion” in the present invention.

As shown in FIG. 2, a p-side ohmic electrode 24 is formed on the lower surface of the ridge portion 23 a of the p-type cladding layer 23. The p-side ohmic electrode 24 has a structure (not shown) in which a Pt layer, a Ti layer, and the like are stacked. Further, on the lower surface of the p-type cladding layer 23 other than the ridge portion 23a, on both side surfaces of the ridge portion 23a, and on both side surfaces of the p-side ohmic electrode 24, a current blocking layer 25 made of SiO ₂ , SiN, or the like. Is formed. A p-side pad electrode 26 made of Au or the like is formed on the lower surfaces of the p-side ohmic electrode 24 and the current blocking layer 25. The p-side pad electrode 26 is formed to have a width W2 of about 60 μm in the X direction. Further, the p-side pad electrode 26 is formed on the inner side than both ends of the blue-violet semiconductor laser element 2 in the X direction in the X direction.

  Further, as shown in FIG. 3, a projecting portion 26b that projects downward (Z2 side) by a length L1 of about 1 μm is formed on the lower surface 26a of the p-side pad electrode 26 at a substantially center in the X direction. . The protrusion 26b has a width W3 of about 2 μm in the X direction. Further, the protruding portion 26b is formed in the region A.

  As shown in FIG. 2, an n-side electrode 27 made of Au or the like is formed on substantially the entire upper surface of the n-type GaN substrate 20.

  The heat radiating base portion 1 includes a heat radiating base 10 made of insulating AlN and an electrode 11 formed on the upper surface 10 a of the heat radiating base 10. As shown in FIG. 3, the electrode 11 has a thickness t <b> 1 of about 1 μm in the height direction (Z direction) of the blue-violet semiconductor laser element 2.

  Here, in 1st Embodiment, as shown in FIG. 1, the electrode 11 is comprised from the electrode parts 11a, 11b, and 11c. The electrode portion 11a is formed on one side (Y1 side) in the direction in which the resonator extends (Y direction) and on one side (X1 side) in the direction (X direction) orthogonal to the direction in which the resonator extends. . The electrode portion 11b is formed on the Y1 side and on the other side in the X direction (X2 side). The electrode portion 11c connects the electrode portion 11a and the electrode portion 11b on the other side (Y2 side) in the Y direction where the blue-violet semiconductor laser element 2 is not disposed.

  The electrode portions 11a and 11b are formed so as to extend along the Y direction, and are separated from each other by a distance D1 of about 10 μm in the X direction. Thus, as shown in FIG. 3, the electrode portions 11a and 11b are formed in the region B not corresponding to the ridge portion 23a, but not formed in the region A corresponding to the ridge portion 23a. The region B not corresponding to the ridge portion 23a is a region excluding the region A.

  A solder layer 12 made of an Au—Sn alloy is formed on the upper surface of the electrode 11. Specifically, solder layers 12a and 12b are formed on the upper surface of the electrode portion 11a and the upper surface of the electrode portion 11b, respectively. That is, the solder layers 12a and 12b are formed in the region B, but are not formed in the region A. The solder layer 12 has a thickness t2 of about 4 μm in the Z direction. The solder layers 12a and 12b are examples of the “fusion layer” in the present invention.

  In addition, the electrode portion 11a of the heat radiation base portion 1 and the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser element 2 are joined via the solder layer 12a in the region B on the X1 side. In addition, the electrode portion 11b of the heat radiation base portion 1 and the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 are joined via the solder layer 12b in the region B on the X2 side. That is, the blue-violet semiconductor laser device 2 is bonded to the heat dissipation base portion 1 in a state where the active layer 22 is positioned closer to the heat dissipation base portion 1 side (Z2 side) than the n-type GaN substrate 20 (junction down method). ing. Thereby, the heat generated in the light emitting region 22 a of the active layer 22 is configured to be dissipated through the heat dissipation base 10.

  Further, the solder layers 12 a and 12 b are formed outside the both end portions in the X direction of the p-side pad electrode 26 in the region B. As a result, in the region B, the solder layers 12 a and 12 b are disposed on substantially the entire surface of the p-side pad electrode 26. Thus, the heat generated in the light emitting region 22a of the active layer 22 when the laser light is emitted passes through the solder layers 12a and 12b disposed on the substantially entire surface of the p-side pad electrode 26 in the region B, and the heat dissipation base 10 It is configured to be communicated to.

  In the first embodiment, as shown in FIG. 3, in the region A corresponding to the ridge portion 23 a, the lower surface 26 a around the protruding portion 26 b of the p-side pad electrode 26, the upper surface 10 a of the heat dissipation base 10, and the solder A gap (space portion) 5 in which the solder layer 12 is not disposed is formed by the side surfaces of the layers 12a and 12b and the side surfaces of the electrode portions 11a and 11b. Due to the gap 5, the protrusion 26b on the lower surface 26a of the p-side pad electrode 26 and the upper surface 10a of the heat dissipation base 10 are about 5 μm (t1 (about 1 μm) in the Z direction (the height direction of the blue-violet semiconductor laser device 2). ) + T2 (about 5 μm) −L1 (about 1 μm)).

  As shown in FIGS. 1 and 2, the n-side electrode 27 of the blue-violet semiconductor laser device 2 is connected to the base portion 3 through a wire 4a. Moreover, the electrode 11 of the heat radiating base 1 is connected to a positive electrode terminal (not shown) via a wire 4b.

  A manufacturing process for the semiconductor laser device 100 according to the first embodiment is now described with reference to FIGS.

  First, a heat radiation base 10 made of AlN is prepared. Then, a mask (not shown) is formed at a predetermined position on the upper surface 10 a of the heat dissipation base 10. At this time, a mask is formed at least on the upper surface 10a (see FIG. 3) of the heat dissipation base 10 corresponding to the region A corresponding to the ridge portion 23a. And the electrode 11 is formed in the part which is not masked using the vacuum evaporation method. As a result, as shown in FIG. 1, the electrode portion 11a formed on the Y1 side and the X1 side and the Y1 side and the X2 side are formed on the upper surface 10a of the heat radiation base 10. An electrode portion 11b and an electrode portion 11c formed on the Y2 side are formed. Thereby, the thermal radiation base part 1 is formed.

  Then, a mask is formed at predetermined positions on the upper surface 10 a of the heat dissipation base 10 and the upper surface of the electrode 11. Then, solder layers 12a and 12b made of an Au—Sn alloy are formed on the portion where the mask is not formed using a coating method. Thereby, as shown in FIG. 4, solder layers 12a and 12b are formed on the upper surfaces of the electrode portions 11a and 11b, respectively.

  Further, an n-type cladding layer 21, an active layer 22 and a p-type cladding layer 23 are sequentially grown on the upper surface of the n-type GaN substrate 20. Next, after forming a resist pattern by a photolithography technique, etching is performed using the resist pattern as a mask, thereby removing regions other than the region near the center in the X direction of the p-type cladding layer 23. Thus, a ridge portion 23a extending in the direction in which the resonator extends (Y direction) is formed. Thereafter, the current blocking layer 25 is formed on the upper surface of the p-type cladding layer 23 other than the ridge portion 23a and on both side surfaces of the ridge portion 23a by plasma CVD and photolithography.

  Then, the p-side ohmic electrode 24 is formed on the upper surface of the ridge portion 23a by using a vacuum deposition method or a sputtering method. Thereafter, the p-side pad electrode 26 is formed on the upper surfaces of the p-side ohmic electrode 24 and a part of the current blocking layer 25 using a vacuum deposition method. Next, the n-side electrode 27 is formed on the lower surface of the n-type GaN substrate 20. Thereby, the blue-violet semiconductor laser element 2 is formed.

  Then, as shown in FIG. 4, the n-side electrode 27 of the blue-violet semiconductor laser device 2 is used by using the collet 6 so that the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 and the heat radiation base portion 1 face each other. Grip the side from above (Z1 side). At this time, the protrusion 26b of the p-side pad electrode 26 is located between the solder layer 12a and the solder layer 12b in the X direction, and the end (on the Y1 side of the blue-violet semiconductor laser device 2 in the Y direction ( 1) and the end portion on the Y1 side of the heat radiating base 1 (resonator surface, see FIG. 1) are aligned to some extent. Then, the p-side pad electrode 26 and the electrode portion 11a of the blue-violet semiconductor laser element 2 are joined (fused) via the solder layer 12a melted by applying heat at about 300 ° C., and the p-side pad electrode 26 and the electrode portion 11b are joined together via the melted solder layer 12b. Thereby, the blue-violet semiconductor laser device 2 is joined to the heat radiation base 1 by the junction down method.

  As a result, as shown in FIG. 3, in the region A corresponding to the ridge portion 23a, the lower surface 26a around the protruding portion 26b of the p-side pad electrode 26, the upper surface 10a of the heat dissipation base 10, and the solder layers 12a and 12b A gap 5 is formed by the side surfaces and the side surfaces of the electrode portions 11a and 11b. Therefore, compared to the case where the gap 5 is not formed in the region A, it is possible to suppress the application of heat to the periphery of the ridge portion 23a.

  Thereafter, as shown in FIGS. 1 and 2, the heat radiating base portion 1 is joined to the base portion 3 by the fusion layer 3 a. Then, the n-side electrode 27 of the blue-violet semiconductor laser device 2 and the base portion 3 are connected by the wire 4a. Further, the electrode 11 of the heat radiating base portion 1 and a lead terminal (positive electrode side) (not shown) are connected by the wire 4b. In this way, the semiconductor laser device 100 is manufactured.

  In the first embodiment, as described above, the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 is dissipated through the solder layers 12a and 12b formed in the region B not corresponding to the ridge portion 23a. Since the solder layer 12 is not disposed in the region A corresponding to the ridge portion 23a by bonding to the electrode portions 11a and 11b of the base 1, the region A is caused by heat damage and heat at the time of fusion. The stress due to the distortion of the solder layer 12 is not substantially generated. In addition, since the solder layer 12 is not disposed in the region A, the components (Au and Sn) of the solder layer 12 that occur when the semiconductor laser device 100 in the region A is used for a long period of time are included in the p-side ohmic electrode 24. Occurrence of a phenomenon (migration) that spreads between the p-side pad electrode 26 and the p-side pad electrode 26 can be suppressed. Furthermore, it is possible to suppress the elements (Ti, Pt, etc.) forming the p-side ohmic electrode 24 and the Sn of the Au—Sn alloy of the solder layer 12 from reacting with heat and being alloyed during fusion. . As a result, even when the blue-violet semiconductor laser device 2 is joined to the heat dissipation base 1 by the junction down method, it is possible to suppress deterioration of the ohmic property of the p-side ohmic electrode 24 formed in the ridge 23a. As a result, an increase in the operating voltage of the blue-violet semiconductor laser device 2 can be suppressed.

  Further, in the first embodiment, the protruding portion 26b of the lower surface 26a of the p-side pad electrode 26 and the upper surface 10a of the heat dissipation base 10 are separated by about 5 μm in the Z direction by the gap 5 formed in the region A. In addition, the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 is connected to the electrode portion of the heat radiation base portion 1 via the solder layers 12a and 12b formed in the region B not corresponding to the ridge portion 23a. If it is configured to be joined to 11a and 11b, nothing is arranged on the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 in the region A. Therefore, in the region A, the blue-violet semiconductor laser device 2 Further, it is possible to further suppress the stress due to the heat damage and the distortion of the solder layer 12 caused by the heat. In addition, the gap 5 can suppress the direct contact between the protruding portion 26b of the lower surface 26a of the p-side pad electrode 26 and the upper surface 10a of the heat dissipation base 10 in the region A.

  In the first embodiment, if the gap 5 is formed in the region A, the end (resonator surface) on the Y1 side of the blue-violet semiconductor laser device 2 is the end on the Y1 side of the heat dissipation base 1 at the time of fusion. Even in the case of joining in a state slightly shifted to the Y2 side from the portion (see FIG. 1), the emission of the laser light from the end portion (resonator surface) on the Y1 side of the blue-violet semiconductor laser element 2 is radiated. It is possible to suppress obstruction by the base unit 1.

  In the first embodiment, the electrode portions 11a and 11b are formed in the region B, but not formed in the region A, so that in the region A, the protrusion 26b on the lower surface 26a of the p-side pad electrode 26 and the heat dissipation base 10 is configured to be separated from the upper surface 10a of the electrode 10 by about 5 μm in the Z direction by the gap 5, at least the thickness t1 (about 1 μm) of the electrode 11 and the protruding portion 26b of the lower surface 26a of the p-side pad electrode 26 The distance D2 of the gap 5 in the Z direction between the upper surface 10a of the heat dissipation base 10 can be increased. Thereby, the space | gap 5 can be ensured between the protrusion part 26b of the lower surface 26a of the p side pad electrode 26, and the upper surface 10a of the thermal radiation base 10 reliably.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. 5 and 6. In the semiconductor laser device 200 according to the second embodiment, in addition to the first embodiment, the blue-violet semiconductor laser element 202 is provided with walls 207a and 207b. In the figure, the same reference numerals are given to the same components as those in the first embodiment.

  First, the structure of the semiconductor laser device 200 according to the second embodiment of the present invention will be described with reference to FIGS.

  In the blue-violet semiconductor laser device 202 of the semiconductor laser device 200 according to the second embodiment, as shown in FIG. 5, on the lower surface of the p-type cladding layer 23 other than the ridge portion 23a, on both side surfaces of the ridge portion 23a, and p Current blocking layers 225 are formed on both side surfaces of the side ohmic electrode 24. The blue-violet semiconductor laser element 202 is an example of the “semiconductor laser element” in the present invention.

  Here, in the second embodiment, as shown in FIG. 6, the current blocking layer 225 has a pair of protrusions formed so as to sandwich the ridge portion 23a in the direction (X direction) orthogonal to the direction in which the resonator extends. It has parts 225a and 225b. The convex portion 225a is formed on the X1 side of the ridge portion 23a so as to protrude downward (Z2 side) from the ridge portion 23a, and the convex portion 225b is formed on the X2 side of the ridge portion 23a. It is formed so as to protrude downward (Z2 side) from 23a. The convex portions 225a and 225b are both formed to extend in the direction in which the resonator extends (Y direction).

  A p-side pad electrode 226 is formed on the lower surfaces of the p-side ohmic electrode 24 and the current blocking layer 225 so as to uniformly cover the protrusions 225a and 225b. As a result, the blue-violet semiconductor laser element 202 has a wall portion 207a made of a convex portion 225a covered with the p-side pad electrode 226 and a wall portion 207b made of a convex portion 225b covered with the p-side pad electrode 226. Is formed. These wall portions 207a and 207b are arranged between the lower surface 26a of the p-side pad electrode 226 excluding the portion where the wall portions 207a and 207b are formed and the upper surface 10a of the heat dissipation base 10 in the Z direction. .

  The wall portions 207a and 207b are formed at the end portions on the X1 side and the X2 side of the region A corresponding to the ridge portion 23a, respectively. Thereby, the side surface on the X1 side of the wall portion 207a is located at the end portion on the X1 side of the region A, and the side surface on the X2 side of the wall portion 207b is located at the end portion on the X2 side of the region A. Has been. The wall portions 207a and 207b are both formed so as to protrude downward (Z2 side) from the protruding portion 26b of the p-side pad electrode 26.

  The solder layer 12a is formed in the region B not corresponding to the ridge portion 23a so as to be in contact with the side surface on the X1 side of the wall portion 207a, and the solder layer 12b is in contact with the side surface on the X2 side of the wall portion 207b. Formed in region B. The wall portions 207a and 207b have a function of suppressing the solder layers 12a and 12b from flowing into the region A.

  Moreover, in 2nd Embodiment, as shown in FIG. 6, in the area | region A, the lower surface 26a around the protrusion part 26b of the p side pad electrode 226, the upper surface 10a of the thermal radiation base 10, and X2 side of the wall part 207a The solder layer 12 is arranged by the side surface and the bottom surface on the Z2 side, the side surface on the X1 side of the wall portion 207b and the bottom surface on the Z2 side, part of the side surfaces of the solder layers 12a and 12b, and the side surfaces of the electrode portions 11a and 11b. A void (space) 205 that is not formed is formed. The remaining configuration of the semiconductor laser apparatus 200 according to the second embodiment is similar to that of the aforementioned first embodiment.

  Next, with reference to FIG. 5, the manufacturing process of the semiconductor laser device 200 according to the second embodiment will be described.

  On the upper surface of the n-type GaN substrate 20, a p-type cladding layer 23 provided with an n-type cladding layer 21, an active layer 22, and a ridge portion 23a is sequentially formed. Thereafter, a current blocking layer 225 is formed on the upper surface of the p-type cladding layer 23 other than the ridge portion 23a and on both side surfaces of the ridge portion 23a. At this time, by etching the regions other than the predetermined positions on the X1 side and X2 side of the ridge portion 23a, protrusions protruding above the upper surface of the ridge portion 23a are respectively formed on the X1 side and X2 side of the ridge portion 23a. Portions 225a and 225b are formed.

  Then, after the p-side ohmic electrode 24 is formed, the p-side pad is formed on the upper surfaces of the p-side ohmic electrode 24 and the current blocking layer 225 so as to uniformly cover the protrusions 225a and 225b using a vacuum deposition method. An electrode 226 is formed. As a result, as shown in FIG. 5, walls 207 a and 207 b are formed in the blue-violet semiconductor laser element 202. The other manufacturing processes of the semiconductor laser device 200 according to the second embodiment are the same as those in the first embodiment.

  In the second embodiment, as described above, the lower surface 26a of the p-side pad electrode 226 of the blue-violet semiconductor laser device 202 is dissipated through the solder layers 12a and 12b formed in the region B not corresponding to the ridge portion 23a. By joining to the electrode portions 11a and 11b of the base portion 1, it is possible to suppress degradation of the ohmic property of the p-side ohmic electrode 24 formed on the ridge portion 23a. An increase in operating voltage can be suppressed.

  In the second embodiment, the walls 207a and 207b having a function of suppressing the solder layers 12a and 12b from flowing into the region A are excluded from the portion where the walls 207a and 207b are formed in the Z direction. If it is arranged between the lower surface 26a of the side pad electrode 226 and the upper surface 10a of the heat dissipation base 10, the solder layer 12 flows into the region A at the time of fusion by the walls 207a and 207b, so that the p-side pad electrode 226 Reaching the lower surface 26a can be reliably suppressed. Thereby, it is possible to effectively prevent the ridge portion 23a of the blue-violet semiconductor laser element 202 from being subjected to heat damage and stress due to distortion of the solder layer 12 caused by heat. The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. In the semiconductor laser device 300 according to the third embodiment, in addition to the first embodiment, the heat radiating base 310 of the heat radiating base 301 is provided with walls 307a and 307b and a recess 310b. In the figure, the same reference numerals are given to the same components as those in the first embodiment.

  First, the structure of the semiconductor laser device 300 according to the third embodiment of the invention will be described with reference to FIGS.

  As shown in FIG. 7, walls 307a and 307b and a recess 310b are formed on the upper surface 310a of the heat dissipation base 310 of the heat dissipation base 301 in the semiconductor laser device 300 according to the third embodiment.

  The wall portions 307a and 307b are formed to protrude upward (Z1 side) on the X1 side and X2 side of the ridge portion 23a, respectively, and to extend in the direction in which the resonator extends (Y direction). The wall portions 307a and 307b are formed at the end portions on the X1 side and the X2 side of the region A corresponding to the ridge portion 23a, respectively. Accordingly, the side surface on the X1 side of the wall portion 307a is positioned at the end portion on the X1 side of the region A, and the side surface on the X2 side of the wall portion 307b is positioned at the end portion on the X2 side of the region A. Has been.

  The electrode portion 11a and the solder layer 12a are both formed in the region B not corresponding to the ridge portion 23a so as to be in contact with the side surface on the X1 side of the wall portion 307a. The electrode portion 11b and the solder layer 12b are both formed in the region B so as to be in contact with the side surface on the X2 side of the wall portion 307b. The wall portions 307a and 307b have a function of suppressing the solder layers 12a and 12b arranged in the region B from flowing into the region A.

  A recess 310b is formed in the region A and in a region sandwiched between the wall portion 307a and the wall portion 307b. The bottom surface of the recess 310b is configured to be positioned lower than the upper surface 310a of the heat dissipation base 310 in the region B by a length L2 (Z2 side). Further, the electrode 11 and the solder layer 12 are not disposed in the recess 310b.

  Moreover, in 3rd Embodiment, as shown in FIG. 7, in the area | region A, the lower surface 26a periphery of the protrusion part 26b of the p side pad electrode 26, the bottom face of the recessed part 310b in the thermal radiation base 310, and wall part 307a and 307b. A gap (space part) 305 in which the solder layer 12 is not disposed is formed by the side surfaces of the solder layer 12 and a part of the side surfaces of the solder layers 12a and 12b. Due to the gap 305, the protrusion 26b of the lower surface 26a of the p-side pad electrode 26 and the bottom surface of the recess 310b of the heat dissipation base 310 are separated by a distance D3 of (t1 + t2 + L2-L1) in the Z direction. . The remaining configuration of the semiconductor laser apparatus 300 according to the third embodiment is similar to that of the aforementioned first embodiment.

  Next, with reference to FIG. 9, a manufacturing process of the semiconductor laser device 300 according to the third embodiment will be described.

  First, a mask (not shown) is formed at a predetermined position on the upper surface 310a of the heat radiation base 310 by using a photolithography technique. At this time, a mask is formed at least in a region corresponding to the wall portions 307a and 307b. Thereafter, by etching the portion where the mask is not formed, as shown in FIG. 9, wall portions 307a and 307b projecting upward (Z1 side) are formed in the portion where the mask is formed. And the recessed part 310b is formed between wall part 307a and 307b by further etching the area | region pinched | interposed into wall part 307a and 307b.

  Then, a mask is formed on at least the upper surfaces of the wall portions 307 a and 307 b and the recess 310 b of the heat dissipation base 310. Then, the electrode portions 11a and 11b and the solder layers 12a and 12b are formed using a vacuum deposition method and a coating method. The other manufacturing processes of the semiconductor laser device 300 according to the third embodiment are the same as those in the first embodiment.

  In the third embodiment, as described above, the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 is dissipated through the solder layers 12a and 12b formed in the region B not corresponding to the ridge portion 23a. By joining to the electrode parts 11a and 11b of the base part 1, it is possible to suppress the degradation of the ohmic property of the p-side ohmic electrode 24 formed on the ridge part 23a, so that the blue-violet semiconductor laser device 2 An increase in operating voltage can be suppressed.

  Further, in the third embodiment, the wall portions 307a and 307b having a function of suppressing the solder layers 12a and 12b from flowing into the region A are connected to the lower surface 26a of the p-side pad electrode 26 and the heat radiation base 310 in the Z direction. If it arrange | positions between the upper surface 310a of this, by wall part 307a and 307b, it can suppress reliably that the solder layer 12 flows into the area | region A at the time of fusion | fusion, and reaches | attains the lower surface 26a of the p side pad electrode 26. it can. Thereby, it is possible to effectively suppress the ridge portion 23a of the blue-violet semiconductor laser element 2 from being subjected to heat damage and stress due to distortion of the solder layer 12 caused by heat.

  In the third embodiment, the electrode portions 11a and 11b and the solder layers 12a and 12b are both formed in the region B, and in the region A and the region sandwiched between the wall portion 307a and the wall portion 307b. If the recess 310b is formed, not only the thickness t1 of the electrode 11 but also the distance L2 in the Z direction of the recess 310b, the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 and the recess 310b of the heat dissipation base 301 are formed. The length (distance D3) of the gap 305 in the Z direction with respect to the bottom surface can be increased. As a result, the gap 305 can be secured more reliably between the lower surface 26 a of the p-side pad electrode 26 and the bottom surface of the recess 310 b of the heat dissipation base 301. The remaining effects of the third embodiment are similar to those of the aforementioned first embodiment.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIGS. In the semiconductor laser device 400 according to the fourth embodiment, unlike the first embodiment, the electrode 411 formed on the upper surface 10a of the heat dissipation base 10 of the heat dissipation base 401 is not only on the Y2 side but also on the Y1 side. Are also connected in the X direction. In the figure, the same reference numerals are given to the same components as those in the first embodiment.

  First, the structure of the semiconductor laser apparatus 400 according to the fourth embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 10 to 12, an electrode 411 is formed on the upper surface 10 a of the heat dissipation base 10 of the heat dissipation base 401 in the semiconductor laser device 400 according to the fourth embodiment. As shown in FIG. 10, the electrode 411 is connected in the X direction not only on the Y2 side but also on the Y1 side. That is, as shown in FIG. 12, the electrode 411 is formed not only in the region B not corresponding to the ridge portion 23a but also in the region A corresponding to the ridge portion 23a. On the other hand, the solder layers 12a and 12b are formed in the region B, but not formed in the region A.

  Further, in the fourth embodiment, in the region A, the gap in which the solder layer 12 is not disposed by the lower surface 26a around the protruding portion 26b of the p-side pad electrode 26, the upper surface of the electrode 411, and the side surfaces of the solder layers 12a and 12b. (Space part) 405 is formed. By this gap 405, the protruding portion 26b of the lower surface 26a of the p-side pad electrode 26 and the electrode 411 of the heat dissipation base 10 are configured to be separated from each other by a distance D4 of (t2-L1) in the Z direction. The remaining configuration of the semiconductor laser apparatus 400 according to the fourth embodiment is similar to that of the aforementioned first embodiment.

  A manufacturing process for the semiconductor laser device 400 according to the fourth embodiment is now described with reference to FIGS.

  First, a mask is formed at a predetermined position on the upper surface 10 a of the heat dissipation base 10. And as shown in FIG. 10, the electrode 411 is formed using a vacuum evaporation method. At this time, the electrode 411 is uniformly formed not only in the region B (see FIG. 12) not corresponding to the ridge portion 23a but also in the region A (see FIG. 12) corresponding to the ridge portion 23a. Thereby, the heat radiation base 401 is formed.

  Then, a mask is formed on the upper surface 10 a of the heat radiating base 10 and a predetermined position of the electrode 411. At this time, a mask is formed on the electrode 411 corresponding to at least the region A. Then, using an application method, as shown in FIG. 11, solder layers 12a and 12b are formed in portions where the mask is not formed. The other manufacturing processes of the semiconductor laser device 400 according to the fourth embodiment are the same as those in the first embodiment.

  In the fourth embodiment, as described above, the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 is dissipated through the solder layers 12a and 12b formed in the region B not corresponding to the ridge portion 23a. Since the ohmic property of the p-side ohmic electrode 24 formed in the ridge portion 23a can be suppressed by bonding to the electrode 411 of the base portion 401, the operating voltage of the blue-violet semiconductor laser device 2 is reduced. The rise can be suppressed. The remaining effects of the fourth embodiment are similar to those of the aforementioned first embodiment.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIG. In the three-wavelength semiconductor laser device 500 according to the fifth embodiment, a red semiconductor laser element 530 and an infrared semiconductor laser element 540 are provided in addition to the blue-violet semiconductor laser element 2 of the first embodiment. In the figure, the same reference numerals are given to the same components as those in the first embodiment. The three-wavelength semiconductor laser device 500 is an example of the “semiconductor laser device” in the present invention.

  First, the structure of a three-wavelength semiconductor laser device 500 according to the fifth embodiment of the invention will be described with reference to FIG.

  As shown in FIG. 13, a blue-violet semiconductor laser element 2 is bonded to the X1 side of the heat dissipation base 10 of the three-wavelength semiconductor laser device 500 according to the fifth embodiment. Further, a two-wavelength semiconductor laser element 508 is bonded to the X2 side of the heat radiation base 10, and this two-wavelength semiconductor laser element 508 is a red semiconductor laser element having an oscillation wavelength of about 650 nm formed on the X1 side. 530 and an infrared semiconductor laser element 540 having an oscillation wavelength of about 780 nm formed on the X2 side. The red semiconductor laser element 530 and the infrared semiconductor laser element 540 are formed on the same n-type GaAs substrate 508a.

  In the red semiconductor laser element 530, an n-type cladding layer 531 made of AlGaInP is formed on the lower surface on the X1 side of the n-type GaAs substrate 508a. On the lower surface of the n-type cladding layer 531, an active layer 532 having an MQW structure in which quantum well layers (not shown) made of GaInP and barrier layers (not shown) made of AlGaInP are alternately stacked is formed. ing. A p-type cladding layer 533 made of AlGaInP is formed on the lower surface of the active layer 532. A ridge portion (convex portion) 533a is formed in the p-type cladding layer 533 at the approximate center in the X direction of the red semiconductor laser element 530. A current blocking layer 534 is formed on the lower surface of the p-type cladding layer 533 other than the ridge portion 533a and on both side surfaces of the ridge portion 533a. A p-side pad electrode 535 is formed on the lower surface of the ridge portion 533a and the lower surface of the current blocking layer 534.

  In the infrared semiconductor laser device 540, an n-type cladding layer 541 made of AlGaAs is formed on the lower surface of the n-type GaAs substrate 508a on the X2 side. An MQW structure in which a quantum well layer (not shown) made of AlGaAs with a low Al composition and a barrier layer (not shown) made of AlGaAs with a high Al composition are alternately stacked on the lower surface of the n-type cladding layer 541. An active layer 542 is formed. A p-type cladding layer 543 made of AlGaAs is formed on the lower surface of the active layer 542. A ridge (projection) 543a is formed in the p-type cladding layer 543 at the approximate center in the X direction of the infrared semiconductor laser device 540. A current blocking layer 544 is formed on the lower surface of the p-type cladding layer 543 other than the ridge portion 543a and on both side surfaces of the ridge portion 543a. A p-side pad electrode 545 is formed on the lower surface of the ridge portion 543a and on the lower surface of the current blocking layer 544.

  The current blocking layers 534 and 544 are connected to each other. An n-side electrode 508b is formed in substantially the entire region on the upper surface of the n-type GaAs substrate 508a.

  Further, electrodes 11, 513 and 514 are formed on the upper surface 10 a of the heat dissipation base 10 of the heat dissipation base portion 501. The electrode 11 is formed on the upper surface 10 a on the X1 side of the heat dissipation base 10. The electrode 513 is formed on the X2 side of the electrode 11 and on the upper surface 10a of the electrode 514 on the X1 side, and the electrode 514 is formed on the upper surface 10a of the heat dissipation base 10 on the X2 side. Yes. Solder layers 515 and 516 are formed on the upper surfaces of the electrodes 513 and 514, respectively. The electrode 513 and the p-side pad electrode 535 of the red semiconductor laser element 530 are joined via the solder layer 515, and the electrode 514 and the p-side pad of the infrared semiconductor laser element 540 are joined via the solder layer 516. The electrode 545 is joined. That is, the red semiconductor laser element 530 and the infrared semiconductor laser element 540 are joined to the heat dissipation base 501 by the junction down method.

  The electrode 11 is composed of electrode portions 11a, 11b and 11c. The electrodes 513 and 514 and the solder layers 515 and 516 are formed at portions corresponding to at least the p-side pad electrodes 535 and 545, respectively. That is, the electrodes 513 and 514 and the solder layers 515 and 516 are formed in both the region corresponding to the ridge portion 533a of the red semiconductor laser element 530 and the region corresponding to the ridge portion 543a of the infrared semiconductor laser device 540, respectively. Has been.

  Further, the n-side electrode 508b of the two-wavelength semiconductor laser element 508 is connected to the base portion 3 through a wire 4c. In addition, the electrodes 513 and 514 of the heat dissipation base 501 are connected to a positive terminal (not shown) via wires 4d and 4e, respectively. The remaining structure of the three-wavelength semiconductor laser device 500 according to the fifth embodiment is similar to that of the aforementioned first embodiment.

  A manufacturing process for the three-wavelength semiconductor laser device 500 according to the fifth embodiment is now described with reference to FIG.

  First, a mask is formed at a predetermined position on the upper surface 10 a of the heat dissipation base 10. At this time, at least a mask is formed on the upper surface 10a of the heat radiation base 10 corresponding to the region A corresponding to the ridge portion 23a of the blue-violet semiconductor laser device 2. And the electrode 11 containing the electrode parts 11a and 11b and the electrodes 513 and 514 are formed using a vacuum evaporation method. Thereby, the heat radiation base part 501 is formed.

  Then, solder layers 12a and 12b are formed on the upper surfaces of the electrode portions 11a and 11b, respectively, and solder layers 515 and 516 are formed on the upper surfaces of the electrodes 513 and 514, respectively.

  The blue-violet semiconductor laser element 2 and the two-wavelength semiconductor laser element 508 are formed by a predetermined manufacturing process. Then, the p-side pad electrode 26 of the blue-violet semiconductor laser element 2 and the electrode portion 11a of the heat dissipation base portion 501 are joined via the solder layer 12a, and the p-side pad electrode 26 and the electrode of the heat dissipation base portion 501 are joined. The part 11b is joined via the solder layer 12b. Further, the p-side pad electrode 535 of the red semiconductor laser element 530 and the electrode 513 of the heat dissipation base 501 are joined via the solder layer 515, and the p-side pad electrode 545 of the infrared semiconductor laser element 540 and the heat dissipation base are connected. The electrode 514 of the base part 501 is joined via the solder layer 516.

  Thereafter, the n-side electrode 27 of the blue-violet semiconductor laser device 2 and the base portion 3 are connected by the wire 4a. The wire 4b connects the electrode 11 of the heat radiation base 501 and a lead terminal (positive electrode side) (not shown). Further, the n-side electrode 508b of the two-wavelength semiconductor laser element 508 and the base portion 3 are connected by the wire 4c. In addition, the wires 4d and 4e connect the electrodes 513 and 514 of the heat radiation base 501 to a lead terminal (positive electrode side) (not shown), respectively. In this way, the three-wavelength semiconductor laser device 500 shown in FIG. 13 is manufactured. The other manufacturing processes of the three-wavelength semiconductor laser device 500 according to the fifth embodiment are the same as those in the first embodiment.

  In the fifth embodiment, as described above, the lower surface 26a of the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 is dissipated through the solder layers 12a and 12b formed in the region B not corresponding to the ridge portion 23a. By joining to the electrode portions 11a and 11b of the base portion 501, it is possible to suppress the ohmic property of the p-side ohmic electrode 24 formed in the ridge portion 23a from being deteriorated, so that an increase in operating voltage is suppressed. A three-wavelength semiconductor laser device 500 provided with the blue-violet semiconductor laser element 2 can be obtained.

  Further, in the fifth embodiment, the red semiconductor laser element 530 and the infrared semiconductor laser element 540 are disposed via the solder layers 515 and 516 formed in both the region corresponding to the ridge portions 533a and 543a and the region not corresponding to the ridge portions 533a and 543a. If it is configured so as to be bonded to the heat radiating base portion 501, the red semiconductor laser element 530 and the infrared semiconductor laser element 540 have relatively high heat resistance and resistance to ohmic deterioration due to heat and stress during fusion. On the other hand, the heat generated when the laser light is emitted is radiated to the heat radiating base 501 by bonding to the heat radiating base 501 via the solder layers 515 and 516 formed in a wider range than the solder layers 12a and 12b. Can tell. The remaining effects of the fifth embodiment are similar to those of the aforementioned first embodiment.

(Sixth embodiment)
Next, an optical pickup device 600 according to a sixth embodiment of the present invention will be described with reference to FIGS. The optical pickup device 600 is an example of the “optical device” in the present invention.

  As shown in FIG. 14, the optical pickup device 600 according to the sixth embodiment of the present invention is emitted from the three-wavelength semiconductor laser device 500 (see FIG. 13) and the three-wavelength semiconductor laser device 500 according to the fifth embodiment. An optical system 650 that adjusts the laser light and a light detection unit 660 that receives the laser light are provided.

  The optical system 650 includes a polarization beam splitter (PBS) 651, a collimator lens 652, a beam expander 653, a λ / 4 plate 654, an objective lens 655, a cylindrical lens 656, and an optical axis correction element 657.

  The PBS 651 totally transmits the laser light emitted from the three-wavelength semiconductor laser device 500 and totally reflects the laser light returning from the optical disk 670. The collimator lens 652 converts the laser light from the three-wavelength semiconductor laser device 500 that has passed through the PBS 651 into parallel light. The beam expander 653 includes a concave lens, a convex lens, and an actuator (not shown). The actuator has a function of correcting the wavefront state of the laser light emitted from the three-wavelength semiconductor laser device 500 by changing the distance between the concave lens and the convex lens.

  The λ / 4 plate 654 converts the linearly polarized laser light converted into substantially parallel light by the collimator lens 652 into circularly polarized light. The λ / 4 plate 654 converts the circularly polarized laser beam returned from the optical disk 670 into linearly polarized light. In this case, the polarization direction of the linearly polarized light is orthogonal to the direction of the linearly polarized light of the laser light emitted from the three-wavelength semiconductor laser device 500. Thereby, the laser beam returning from the optical disk 670 is substantially totally reflected by the PBS 651. The objective lens 655 converges the laser light transmitted through the λ / 4 plate 654 onto the surface (recording layer) of the optical disc 670. The objective lens 655 is movable by an objective lens actuator (not shown).

  Further, a cylindrical lens 656, an optical axis correction element 657, and a light detection unit 660 are arranged along the optical axis of the laser light totally reflected by the PBS 651. The cylindrical lens 656 imparts astigmatism to the incident laser light. The optical axis correction element 657 is configured by a diffraction grating, and a spot of zero-order diffracted light of each of blue-violet, red, and infrared laser beams that has passed through the cylindrical lens 656 is on a detection region of the light detection unit 660 described later. They are arranged to match.

  Further, the light detection unit 660 outputs a reproduction signal based on the intensity distribution of the received laser light. Thus, an optical pickup device 600 including the three-wavelength semiconductor laser device 500 is configured.

  In the optical pickup device 600, the three-wavelength semiconductor laser device 500 includes blue-violet, red, and infrared light from the blue-violet semiconductor laser element 2, the red semiconductor laser element 530, and the infrared semiconductor laser element 540 (see FIG. 13), respectively. The laser beam can be emitted independently. As described above, the laser light emitted from the three-wavelength semiconductor laser device 500 is the PBS 651, the collimator lens 652, the beam expander 653, the λ / 4 plate 654, the objective lens 655, the cylindrical lens 656, and the optical axis correction element. After being adjusted by 657, the light detection unit 660 is irradiated on the detection region.

  Here, when reproducing the information recorded on the optical disk 670, the laser power emitted from the blue-violet semiconductor laser element 2, the red semiconductor laser element 530, and the infrared semiconductor laser element 540 is made constant. In this way, it is possible to irradiate the recording layer of the optical disc 670 with laser light and to obtain a reproduction signal output from the light detection unit 660. When information is recorded on the optical disk 670, the laser power emitted from the blue-violet semiconductor laser element 2 and the red semiconductor laser element 530 (infrared semiconductor laser element 540) is controlled based on the information to be recorded. However, the optical disk 670 is irradiated with laser light. Thereby, information can be recorded on the recording layer of the optical disc 670. In this manner, recording and reproduction on the optical disc 670 can be performed using the optical pickup device 600 including the three-wavelength semiconductor laser device 500.

  In the sixth embodiment, as described above, the optical pickup device 600 includes the three-wavelength semiconductor laser device 500 in the fifth embodiment, thereby including the blue-violet semiconductor laser element 2 in which the increase in operating voltage is suppressed. An optical pickup device 600 including the wavelength semiconductor laser device 500 can be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first embodiment, the ridge portion 23a is formed in the blue-violet semiconductor laser device 2 so that the protruding portion 26b protruding downward is formed on the lower surface 26a of the p-side pad electrode 26. The present invention is not limited to this. In the present invention, a flat p-type cladding layer 723 is formed on the blue-violet semiconductor laser element 702 as in the semiconductor laser device 700 which is a modification of the first embodiment shown in FIG. A current blocking layer 725 having an opening 725 c extending in the (Y direction) may be formed. In addition, the p-side ohmic electrode 724 is disposed in the opening 725c, and the regions of the n-type cladding layer 21, the active layer 22, and the p-type cladding layer 723 corresponding to the opening 725c become the current path portion 702a. It is configured. The blue-violet semiconductor laser element 702 is a “semiconductor laser element” in the present invention.

  In the first to fourth embodiments, the gap 5 (205, 305,...) Is provided between the p-side pad electrode 26 of the blue-violet semiconductor laser device 2 (202) and the heat radiation base 1 (301, 401). 405) is shown, and in the fifth embodiment, the gap 5 is provided between the p-side pad electrode 26 of the blue-violet semiconductor laser element 2 and the heat radiation base 501 while the red semiconductor laser element is provided. Although an example in which no gap is provided between the p-side pad electrode 535 of 530 and the p-side pad electrode 545 of the infrared semiconductor laser element 540 and the heat dissipation base portion 501 has been shown, the present invention is not limited to this. The present invention is not limited to the case where the blue-violet semiconductor laser element and the heat dissipation base are bonded as long as it is a junction down system in which the p-side pad electrode side of the semiconductor laser element and the heat dissipation base are bonded. For example, when a red semiconductor laser element, an infrared semiconductor laser element, a green semiconductor laser element, or the like is joined to the heat dissipation base portion by a junction down method, a gap is formed between each p-side pad electrode and the heat dissipation base portion. It may be provided.

  Moreover, in the said 3rd Embodiment, although the wall parts 307a and 307b and the recessed part 310b were provided in the thermal radiation base 310 of the thermal radiation base part 301, this invention is not limited to this. In this invention, you may provide only a recessed part, without providing a wall part in a thermal radiation base. At this time, after providing an electrode and a solder layer on the upper surface of the heat dissipation base, etching is performed in a state where a mask is formed in the area corresponding to the recess, so that the solder layer, the electrode and the heat dissipation base in the area corresponding to the recess are formed. May be removed in the same step. Thereby, it is possible to provide a recess on the upper surface of the heat dissipation base more easily.

  In the first to fifth embodiments, the solder layers 12a and 12b are formed in the region B not corresponding to the ridge portion 23a, but not formed in the region A corresponding to the ridge portion 23a. The invention is not limited to this. In the present invention, the solder layer need not be disposed on the lower surface of the p-side pad electrode of the blue-violet semiconductor laser element in at least the region A corresponding to the ridge portion. That is, even in the case where the solder layer is arranged so as to cover the upper surface of the heat dissipation base portion in the region A (when the solder layer flows into the region A), the blue-violet semiconductor laser in the region A It is sufficient that the p-side pad electrode of the element and the solder layer are not in contact.

  In the fifth embodiment, the three-wavelength semiconductor laser device 500 includes the blue-violet semiconductor laser element 2 and the two-wavelength semiconductor laser element 508 including the red semiconductor laser element 530 and the infrared semiconductor laser element 540. Although an example is shown, the present invention is not limited to this. For example, the three-wavelength semiconductor laser device may be configured to include a red semiconductor laser element, a green semiconductor laser element, and a blue semiconductor laser element. Thereby, it is possible to form a three-wavelength semiconductor laser device having the three primary colors of RGB.

1, 301, 401, 501 Radiation base 2, 202, 702 Blue-violet semiconductor laser element (semiconductor laser element)
5, 205, 305, 405 Air gap 10, 310 Heat radiation base 11 Electrode 12a, 12b Solder layer (fusion layer)
22 Active layer 23a Ridge part (current path part)
100, 200, 300, 400, 700 Semiconductor laser device 207a, 207b, 307a, 307b Wall portion 310b Recessed portion 500 Three-wavelength semiconductor laser device (semiconductor laser device)
600 Optical pickup device (optical device)
702a Current passage part

Claims (6)

A heat dissipating base,
A semiconductor laser element that is joined to the heat dissipation base portion via a fusion layer and includes an active layer and a current path portion;
The fusion layer is disposed in a region excluding the region corresponding to the current path portion, and the surface on the active layer side of the semiconductor laser element is disposed in a region excluding the region corresponding to the current path portion. A semiconductor laser device bonded to the heat dissipation base through the fused layer.   In the region corresponding to the current path portion, a gap is formed between the surface of the semiconductor laser element on the active layer side and the surface of the heat dissipation base portion facing the semiconductor laser element, and 2. The semiconductor laser device according to claim 1, wherein a surface of the semiconductor laser element and a surface of the heat dissipation base are joined in a region excluding a region corresponding to a current path portion. The heat radiating base part includes a heat radiating base and an electrode formed on a surface of the heat radiating base facing the semiconductor laser element, and for supplying power to the semiconductor laser element,
The electrode is formed in a region excluding the region corresponding to the current passage portion, so that the gap is provided between the surface of the semiconductor laser element and the surface of the heat dissipation base in the region corresponding to the current passage portion. The semiconductor laser device according to claim 2, wherein: The heat dissipating base has a recess provided on the surface of the heat dissipating base facing the semiconductor laser element;
The electrode is formed in a region excluding the region corresponding to the current passage portion, and the recess is formed in a region corresponding to the current passage portion, whereby the surface of the semiconductor laser element and the heat dissipation base The semiconductor laser device according to claim 3, wherein the gap is formed between the bottom surface of the recess.   Between the surface of the semiconductor laser element on the active layer side and the surface of the heat dissipation base portion facing the semiconductor laser element, the surface of the semiconductor laser element and the surface of the heat dissipation base portion are joined. 5. The semiconductor laser device according to claim 1, wherein a wall portion is arranged to prevent the melted fusion layer from flowing into a region corresponding to the current passage portion. A heat dissipation base portion and a semiconductor laser element having an active layer and a current path portion joined to the heat dissipation base portion via a fusion layer, wherein the fusion layer is a region corresponding to the current path portion And the surface on the active layer side of the semiconductor laser element is disposed on the heat dissipation base via the fusion layer disposed on the region excluding the region corresponding to the current path portion. A semiconductor laser device bonded to the portion;
An optical device comprising: an optical system that controls emitted light of the semiconductor laser device.

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