JP2022078403A - Semiconductor laser device and manufacturing method for semiconductor laser device - Google Patents

Abstract

To provide a semiconductor laser device with high performance, in which high heat dissipation is secured.SOLUTION: A semiconductor laser device includes a laser unit 10 and a modulator 30 for modulating laser light. The laser unit includes a first electrode layer C10 in contact with a surface of a submount 1 on a first direction Y1 side, a first conductivity type semiconductor layer C9, an active layer C8, second conductivity type semiconductor layers C4-1, C4-2, and C3, and a second electrode layer C1 that are stacked in a thickness direction Y. The length of the first conductivity type semiconductor layer C9 in the thickness direction Y is formed to be a length L1 at which the stress applied in the active layer C8 from the first electrode layer C10 side becomes a first value that is set or less, and the length of the second conductivity type semiconductor layers C4-1, C4-2, and C3 in the thickness direction Y is formed to be a length L2 smaller than the length L1. On the second electrode layer C1, a protrusion part 11 protruding to the first direction Y1 side is formed. The protrusion part 11 is provided apart from a first connection line 3 that supplies current to the active layer C8.SELECTED DRAWING: Figure 1

Description

The present application relates to a semiconductor laser device and a method for manufacturing a semiconductor laser device.

Conventionally, in order to efficiently dissipate the heat generated in the semiconductor laser device and secure its characteristics, the following semiconductor laser in which the electrode on the side close to the active layer, which is the heat source of the semiconductor laser device, is bonded to the submount. The device is disclosed.
That is, in the conventional semiconductor laser device, the substrate, the n-type clad layer, the active layer, the p-type clad layer, the p-type contact layer, the p-side electrode, and the other of the substrates, which are sequentially laminated on one surface side of the substrate, are used. It has a semiconductor laser device having an n-type electrode formed on the surface of the surface. The distance from the active layer to the p-type electrode is shorter than the distance from the active layer to the n-type electrode, and the p-type electrode is bonded to the submount. The submount is joined to the first radiator on the surface opposite to the semiconductor laser device. By fixing the active layer as a heat source to the submount so as to be close to the submount in this way, the heat generated in the active layer is transferred to the submount and the first radiator (see, for example, Patent Document 1). ).

Japanese Unexamined Patent Publication No. 2019-62033 (paragraphs [0038] to [089], FIGS. 1 to 7).

In such a semiconductor laser device, heat from the active layer is efficiently transferred to the submount and the first radiator to dissipate heat by joining the electrode on the side close to the active layer to the submount. However, in order to join the electrode on the side close to the active layer to the submount in this way, for example, when mounting a semiconductor laser element, the coefficient of thermal expansion of the adhesive material such as solder for joining to the submount and the semiconductor racer element Stress such as thermal stress due to the difference between the coefficient of thermal expansion of the material and the coefficient of thermal expansion is likely to be applied to the active layer. As a result, there is a problem that the active layer is distorted and the wavelength of the laser beam is skipped, resulting in deterioration of performance.
The present application discloses a technique for solving the above-mentioned problems, and an object thereof is to provide a high-performance semiconductor laser device and a method for manufacturing a semiconductor laser device while ensuring high heat dissipation. ..

The semiconductor laser device disclosed in the present application is
It is a semiconductor laser device including a laser unit that emits laser light and a modulator unit that modulates the laser light emitted from the laser unit, and the laser unit and the modulator unit are integrated in a submount. hand,
The laser portion includes a first electrode layer that abuts on a surface of the submount on the first direction side in the thickness direction and is connected to the submount.
A first conductive semiconductor layer provided on the first direction side of the first electrode layer,
The active layer provided on the first direction side of the first conductive semiconductor layer and
A second conductive semiconductor layer provided on the first direction side of the active layer, and
A second electrode layer provided on the first direction side of the second conductive semiconductor layer is provided.
The length of the first conductive semiconductor layer in the thickness direction is formed to have a length L1 in which the stress in the active layer applied from the first electrode side is equal to or less than the set first value. The length of the second conductive semiconductor layer in the thickness direction is formed to have a length L2 shorter than the length L1 of the first conductive semiconductor layer.
On the second electrode layer, a protrusion is provided that protrudes from the second electrode layer toward the first direction, and the protrusion supplies a current to the active layer via the second electrode layer. 1 Provided away from the connection line,
It is a thing.
Further, the method for manufacturing a semiconductor laser device disclosed in the present application is as follows.
In the method for manufacturing a semiconductor laser device configured as described above,
The wire material is melted by a wire bonding device, and the first connection line is wired.
The wire is melted by the wire bonding device to form the protrusion.
It is a thing.

According to the method for manufacturing a semiconductor laser device and a semiconductor laser device disclosed in the present application, a method for manufacturing a semiconductor laser device and a high-performance semiconductor laser device while ensuring high heat dissipation can be obtained.

It is a top view which shows the schematic structure of the semiconductor laser apparatus by Embodiment 1. FIG. It is sectional drawing of the semiconductor laser apparatus by Embodiment 1. FIG. It is a side view of the semiconductor laser apparatus according to Embodiment 1. FIG. It is a top view of the semiconductor laser element according to Embodiment 1. FIG. It is sectional drawing of the DFB laser part of the semiconductor laser element by Embodiment 1. FIG. It is sectional drawing of the waveguide part of the semiconductor laser element according to Embodiment 1. FIG. It is sectional drawing of the modulator part of the semiconductor laser element according to Embodiment 1. FIG. It is sectional drawing of the semiconductor laser apparatus by Embodiment 1. FIG. It is sectional drawing of the semiconductor laser apparatus by Embodiment 1. FIG. It is a top view which shows the schematic structure of the semiconductor laser apparatus by Embodiment 2. FIG. It is sectional drawing of the semiconductor laser apparatus by Embodiment 2. FIG. It is a side view of the semiconductor laser apparatus according to Embodiment 2. FIG. It is a top view which shows an example of the structure of the semiconductor laser element by Embodiment 2. FIG. It is a top view which shows an example of the structure of the semiconductor laser element by Embodiment 2. FIG. It is a top view which shows an example of the structure of the semiconductor laser element by Embodiment 2. FIG. It is a top view which shows an example of the structure of the semiconductor laser element by Embodiment 2. FIG. It is a top view which shows the schematic structure of the semiconductor laser apparatus by Embodiment 3. FIG. It is sectional drawing of the semiconductor laser apparatus by Embodiment 3. FIG. It is a side view of the semiconductor laser apparatus according to Embodiment 3. FIG.

Embodiment 1.
FIG. 1 is a top view showing a schematic configuration of the semiconductor laser device 100 according to the first embodiment.
FIG. 2 is a cross-sectional view taken along the line AA'of the semiconductor laser device 100 shown in FIG.
FIG. 3 is a side view of the semiconductor laser device 100 shown in FIG. 1 as viewed from the direction of arrow B.
The semiconductor laser device 100 includes a semiconductor laser element C and a submount 1 which is a flat plate-shaped substrate on which the semiconductor laser element C is mounted. The semiconductor laser device C is connected to the submount 1 by using the wire 3 as the first connecting line.

In the following description, the thickness direction of the submount 1 shown in FIG. 2 is the thickness direction Y, one direction of the thickness direction Y is the upward direction Y1, and the direction opposite to the upward direction Y1 is defined as the first direction. It is shown as the downward direction Y2 as the second direction. Further, of the directions perpendicular to the thickness direction Y, the horizontal direction in the top view of the semiconductor laser apparatus 100 of FIG. 1 is shown as the horizontal direction X, and the vertical direction is shown as the vertical direction Z as the third direction. Other components constituting the semiconductor laser device 100 will also be described with reference to these directions.

First, the detailed configuration of the semiconductor laser device C will be described with reference to FIGS. 4 to 7.
FIG. 4 is a top view of the semiconductor laser device C before being mounted on the submount 1.
The semiconductor laser element C includes a distributed feedback type DFB (Distributed fedback laser diode) laser unit 10 as a laser unit that emits a laser beam of a single wavelength, and an electric field that modulates the laser light emitted from the DFB laser unit 10. It is an electric field absorption type modulator integrated semiconductor laser (EML-LD: Electro-absorption moderator Laser Diode) which is provided by integrating the absorption type modulator unit 30.

A waveguide 20A is formed between the DFB laser unit 10 and the modulator unit 30 to guide the laser light radiated from the DFB laser unit 10 to the modulator unit 30. Further, a waveguide section 20B for waveguideing the laser beam emitted from the modulator section 30 is formed between the modulator section 30 and the laser beam emitting port Cout that emits the laser beam.

Hereinafter, the configuration of the DFB laser unit 10 will be described first.
FIG. 5 is a cross-sectional view taken along the DD'line of the DFB laser unit 10 of the semiconductor laser device C shown in FIG.

As shown in FIG. 5, the DFB laser unit 10 abuts on the upper surface (upper surface) of the sub mount 1 on the upward Y1 side and serves as a first electrode layer electrically connected to the upper surface of the sub mount 1. The electrode C10 is provided. Then, an n-type semiconductor substrate C9 (hereinafter referred to as a substrate C9) as the first conductive semiconductor layer provided on the upward Y1 side of the electrode C10 and an active layer C8 provided on the upward Y1 side of the substrate C9. The diffraction grid C7 provided on the upward Y1 side of the active layer C8 and the p-type clad layers C4-1 and C4-2 as the second conductive semiconductor layer provided on the upward Y1 side of the diffraction grid C7. The p-type contact layer C3 and the p-type clad layers C4-1 and C4-2 and the electrode C1 as a second electrode layer formed on the upward Y1 side of the p-type contact layer C3 are provided, and each of these layers is provided. They are laminated in the thickness direction Y.

Further, in the substrate C9, the cross section of the thickness direction Y including the active layer C8, the diffraction grating C7, and the p-type clad layer C4-1 has a mesa-shaped shape, and the mesa as the first mesa stripe portion having a width W1. The striped portion Cme is formed so as to extend in the vertical direction Z perpendicular to the thickness direction Y. Then, an embedded layer Cbo, which is a semiconductor layer, is formed so as to embed both side surfaces of the active layer C8, the diffraction grating C7, and the p-type clad layer C4-1 of the mesa stripe portion Cme. The embedded layer Cbo of the present embodiment is configured by covering the n-type block layer C6, which is an n-type semiconductor layer, with the p-type block layer C5, which is a p-type semiconductor layer.

On the surface (upper surface) on the upper Y1 side of the electrode C1, the first distance H1 set so that the two groove portions M recessed from the upper surface to the lower Y2 side sandwich the mesa stripe portion Cme is provided. It is formed by being separated and stretched in the vertical direction Z.
Further, an insulating layer C2 is formed between the electrode C1 and the p-type contact layer C3. The insulating layer C2 has an opening Cop as a first opening having a width W1 formed by stretching in the vertical direction Z on the upward Y1 side of the active layer C8. As a result, the electrode C1 is bonded to the p-type contact layer C3 only at the connection portion P2 above the active layer C8, and is insulated from the p-type contact layer C3 by the insulating layer C2 at other portions.

Here, the length L1 of the n-type semiconductor substrate (substrate C9) on the Y2 side in the downward direction from the active layer C8 is formed so as to secure a length of 80 μm or more. Further, the length L2 in the thickness direction of the p-type semiconductor layer (p-type clad layers C4-1, C4-2 and p-type contact layer C3) on the Y1 side in the upward direction from the active layer C8 is the length L1 of the substrate C9. Formed shorter than. That is, the active layer C8 serving as a heat source is arranged in the semiconductor laser element C at a position closer to the electrode C1 on the upward Y1 side than the electrode C10 side on the downward Y2 side of the semiconductor laser element C.

In the method for manufacturing a semiconductor laser device C having the above configuration, for example, an active layer C8 made of a material such as InGaAsP, AlGaInAs, or GaInAsP is formed on an n-InP substrate C9 having a thickness of 100 μm. Then, a diffraction grating C7 is formed on the active layer C8. Then, on the diffraction grating C7, the p-InP clad layer C4-1 in which the diffraction grating C7 is embedded is formed to form a semiconductor intermediate laminate.

Then, in this semiconductor intermediate laminate, etching is performed by a dry etching method to the depth of D1 while leaving only the region of the width of W1. Then, the p-InP / n-InP / p-InP block layers C5 and C6 are formed so as to embed both side surfaces of the active layer C8, the diffraction grating C7, and the p-InP clad layer C4-1. Next, the p-InP clad layer C4-2 is formed on the p-InP clad layer C4-1 and the p-InP block layer C5, and the p-InGaAs contact layer C3 is placed on the p-InP clad layer C4-2. Form.

After the p-InGaAs contact layer C3 is formed, the groove M is formed by a dry etching method or a wet etching method so as to cut up to the n-InP block layer C6 in the thickness direction Y. Then, a SiN insulating layer C2 having an opening Cop that opens only above the active layer C8 is formed on the p-InGaAs contact layer C3 and in the groove M. Then, the electrodes C1 and C10 are formed on the surface side of the SiN insulating layer C2 on the upward Y1 side and the surface side of the substrate C9 on the downward Y2 side by a thin-film deposition method, a sputtering method, a plating method, or the like.

The above manufacturing method and configuration are examples. For example, as the configuration of another semiconductor laser device C, a structure having an active layer such as GaInNAs on a GaAs substrate, and p-InP / Fe-InP / n-InP as a block layer. A structure having a / p-InP block layer or a block layer made of a high resistance semiconductor is also assumed.

Next, the configurations of the waveguide portions 20A and 20B of the semiconductor laser element C will be described.
FIG. 6 is a cross-sectional view of the waveguide portions 20A and 20B of the semiconductor laser device C shown in FIG. 4 in the EE line and the GG'line. Assuming that the configurations of the waveguide portions 20A and 20B are the same, only FIG. 6 will be described.

The configurations of the waveguide portions 20A and 20B shown in FIG. 6 are almost the same as the configurations of the DFB laser unit 10 shown in FIG. 5, but they are connected to the active layer C8 instead of the active layer C8 of the DFB laser unit 10. The difference is that the waveguide layer C8GU that guides the laser light radiated from the DFB laser unit 10 to the modulator unit 30 is provided, the diffraction grating C7 is not provided, and the electrodes C1 and C10 are not provided. .. Further, since the waveguide portions 20A and 20B do not have electrodes as described above, an opening is not formed in the insulating layer C2.

Next, the configuration of the modulator unit 30 of the semiconductor laser device C will be described.
FIG. 7 is a cross-sectional view taken along the line FF'of the modulator unit 30 of the semiconductor laser device C shown in FIG.
The configuration of the modulator unit 30 is almost the same as the configuration of the DFB laser unit 10, but instead of the active layer C8 of the DFB laser unit 10, it is connected to the waveguide layer C8GU of the waveguide unit 20A (20B). The point that the light absorption layer C8EA for absorbing the laser light emitted from the DFB laser unit 10 is provided is different from the point that the diffraction grating C7 is not provided. Therefore, the mesa stripe portion CmeEA as the second mesa stripe portion in the modulator unit 30 includes the light absorption layer C8EA.
Further, instead of the electrodes C1 and C10 of the DFB laser unit 10, the electrodes C10EA and the fourth electrode layer as the third electrode layer formed electrically independently of the electrodes C1 and C10 of the DFB laser unit 10 are used. The difference is that the electrode C1EA is provided.

Further, the insulating layer C2 of the modulator unit 30 is formed with an opening CopEA as a second opening that opens above the light absorption layer C8EA. As a result, the electrode C1EA is bonded to the p-type contact layer C3 only above the light absorption layer C8EA, and is insulated from the p-type contact layer C3 by the insulating layer C2 at other portions.

As described above, the substrate C9, the p-type clad layer C4-1, C4-2, the p-type contact layer C3, the insulating layer C2, the embedded layer Cbo, and the groove portion M in the DFB laser unit 10 extend from the DFB laser unit 10. Then, it is also formed in the waveguide sections 20A and 20B and the modulator section 30, respectively.

The configuration of the semiconductor laser device 100 including the semiconductor laser element C configured as described above will be described by returning to FIGS. 1 to 3.
As described above, the semiconductor laser device 100 is formed by mounting the semiconductor laser element C on the submount 1. Specifically, the semiconductor laser element C is die-bonded onto the submount 1 with an adhesive such as solder, and the electrode C10 on the downward Y2 side thereof is connected to an electrode (not shown) on the submount 1.

Further, two submount wirings 2 and 2EA that are electrically independent from each other are formed on the submount 1. The electrode C1 on the upward Y1 side of the DFB laser unit 10 of the semiconductor laser element C is connected to the submount wiring 2 by the wire 3, and the electrode C1EA of the modulator unit 30 is connected to the submount wiring 2EA by the wire 3. Ru.
In this way, the electrode C1 of the DFB laser unit 10 of the semiconductor laser element C is supplied with a current from the submount wiring 2 via the wire 3, and the electrode C1EA of the modulator unit 30 is supplied from the submount wiring 2EA via the wire 3. A voltage is applied.

When a current is supplied to the electrode C1 of the DFB laser unit 10 of the semiconductor laser element C, the current is connected to the electrode C1 and the p-type contact layer C3 from the connection portion P1 between the electrode C1 and the wire 3 shown in FIG. It flows through the layer of the electrode C1 toward the portion P2. Then, a current is supplied from the connection portion P2 to the active layer C8 to generate light, and the diffraction grating C7 intensifies the light having a specific wavelength and emits a laser beam having a single wavelength. The emitted laser light is guided to the light absorption layer C8EA of the modulator unit 30 via the waveguide layer C8GU of the waveguide unit 20A.

Further, when a voltage is applied to the electrode C1EA of the modulator unit 30 of the semiconductor laser element C, the amount of light absorption in the light absorption layer C8EA of the modulator unit 30 changes according to the application of this voltage. In this way, the laser light emitted by the DFB laser unit 10 is modulated by the modulator unit 30 and emitted from the laser light emission port Cout via the waveguide layer C8GU of the waveguide unit 20B.

Here, in order to improve the heat dissipation in the semiconductor laser element C, a stud bump as a protruding portion, which is a ball formed by melting, for example, a metallic wire material, is placed on the electrode C1 of the DFB laser unit 10. A plurality of 11s (10 in this embodiment) are provided.

In the present embodiment, a ball formed by melting the tip of the wire material of the wire 3 connecting the electrode C1 and the submount wiring 2 by a wire bonding device is joined onto the electrode C1 to form a stud bump 11. There is. As the wire bonding apparatus, for example, an ultrasonic generator that melts a metal wire by ultrasonic vibration and joins it on the electrode C1, a heater that melts the wire by heating and thermocompression-bonds it on the electrode C1, and the like are used. be able to.

The positions where these stud bumps 11 are formed on the electrode C1 of the DFB laser unit 10 are located on both outer sides of the groove portion M, that is, at positions opposite to the side on which the active layer C8 is located across the groove portion M. be. Further, the position is separated from the wire 3 so as not to come into contact with the wire 3 that contributes to the electric circuit.
Further, the stud bump 11 is formed after the semiconductor laser element C is die-bonded onto the submount 1 and before the wire 3 is wired. If an attempt is made to form the stud bump 11 after wiring the wire 3 that contributes to the electric circuit, a part of the wire bonding device may come into contact with the wire 3 during the formation of the stud bump 11 and cause a problem. .. Therefore, the stud bump 11 is formed before the wire 3 is wired.

The submount 1, submount wiring 2, and 2EA are, for example, thin film resistors, Sn / Ag, Sn / Ag / Cu, Sn / Ag / Bi / on an aluminum nitride (AlN) substrate or an alumina (Al2O3) substrate. A bonding pattern composed of lead-free solder such as In, Sn / Ag / Cu / Ni / Ge, Sn / Bi, Sn / Bi / Ag, Sn / Bi / Cu, and materials such as Au, Cu, and Pt. It is assumed that the wiring pattern, etc., is applied.

As the wire material forming the wire 3 and the stud bump 11, for example, Au, Au alloy, Cu, Al, Ag and the like are assumed. Further, as described above, the wire connecting the semiconductor laser element C and the submount 1 and the wire material used for forming the stud bump 11 are the same wire for the purpose of standardizing the manufacturing process and reducing the process. The material is used. However, the present invention is not limited to this, or different wire materials may be used in consideration of material cost and compatibility with the material of the semiconductor laser device C.

Hereinafter, the effect of improving the heat dissipation of the semiconductor laser element C by the stud bump 11 and the effect of reducing the stress on the active layer C8 by the semiconductor laser element C having the above configuration will be described.
As described above, the active layer C8, which is a heat source, is formed in the semiconductor laser element C at a position closer to the electrode C1 on the upward Y1 side than the electrode C10 side on the downward Y2 side of the semiconductor laser element C. .. As a result, the heat generated in the active layer C8 is more transferred to the electrode C1 side close to the active layer C8.

Here, since the stud bump 11 is formed on the electrode C1, the heat capacity and the surface area of the electrode C1 are increased by the stud bump 11. Therefore, the heat generated in the active layer C8 of the semiconductor laser element is more efficiently conducted not only to the electrode C10 side but also to the electrode C1 side by the heat capacity increased by the stud bump 11, and is also increased by the stud bump 11. Heat is efficiently radiated by the surface surface of the electrode C1. As a result, heat dissipation from the electrode C1 from the upward Y1 side of the semiconductor laser element C is promoted, and as a result, the heat dissipation property of the semiconductor laser element C is improved.

Further, the active layer C8 is included in the mesa stripe portion Cme having a mesa shape, and the upper surface and both side surfaces of the active layer C8 are not configured to abut on an insulating film having low thermal conductivity, but have thermal conductivity. The structure is such that the p-type clad layer C4-1, which is a high semiconductor layer, and the embedded layer Cbo are in contact with each other. As a result, the heat generated in the active layer C8 can be efficiently transferred to the electrode C1 side, and the heat dissipation effect can be improved.

Further, the substrate C9 formed on the downward Y2 side of the active layer C8 is formed so as to secure a length L1 in the thickness direction Y of 80 μm or more. The length L1 of 80 μm or more is caused by the difference between the coefficient of thermal expansion of the adhesive material such as solder and the coefficient of thermal expansion of the material of the semiconductor laser element C when the semiconductor laser element C is bonded to the submount 1. The thickness is such that the stress applied to the active layer C8 from the electrode C1 side, such as thermal stress, is reduced to the first value or less, which is the stress within the allowable range in the active layer C8.

As described above, while ensuring the length L1 of the substrate C9 capable of reducing the stress applied to the active layer C8 from the electrode C10 side, the active layer C8, which is a heat source, is provided by the stud bump 11 in the semiconductor laser element C. By forming it at a position close to the electrode C1 having an increased heat capacity and surface area, it is possible to achieve both the effect of reducing stress applied to the active layer C8 and the effect of improving heat dissipation from the active layer C8.

Further, if the upper limit of the length L1 in the thickness direction Y of the substrate C9 is set to 130 μm or less and the length L1 of the substrate C9 is formed within the range of 80 μm or more and 130 μm or less, the substrate C9 may be cracked or chipped during manufacturing. It is possible to suppress burrs, etc., and improve the yield. More preferably, the length L1 of the substrate C9 is 110 μm or more and 130 μm or less.
In this way, it is possible to improve the yield at the time of manufacturing and improve the productivity while reducing the stress applied to the active layer C8.

Further, as shown in FIG. 2, the opening Cop of the insulating layer C2 narrows the inlet for supplying the current to the active layer C8 only to the connection portion P2 above the active layer C8. On top of that, the active layer C8 is configured to have a short width X in the lateral direction so as to be included in the mesa stripe portion Cme having a width W1 on the downward Y2 side of the connection portion P2.
As described above, the active layer C8 is not configured to have the same width of the lateral direction X as the electrode C1 located on the Y1 side in the upward direction. Therefore, the distance X in the lateral direction between the stud bump 11 formed on the electrode C1 and the active layer C8 can be secured at least the set second distance H2. As a result, the active layer C8 can be protected from damage caused by ultrasonic vibration, heat, etc. applied to the semiconductor laser element C when the stud bump 11 is bonded to the electrode C1.

Further, the stud bump 11 is formed at a position opposite to the side where the active layer C8 is located so as to sandwich the groove M. In this way, by interposing a groove between the active layer C8 and the stud bump 11 to secure a long creepage distance between the active layer C8 and the stud bump 11, ultrasonic waves at the time of joining the stud bump 11 are secured. The active layer C8 can be protected from damage caused by vibration, heat, and the like.
Further, if the connection point P1 between the wire 3 contributing to the electric circuit and the electrode C1 is formed at a position opposite to the side where the active layer C8 is located with the groove portion M interposed therebetween, the wire 3 is similarly joined. The active layer C8 can be protected from damage caused by ultrasonic vibration, heat, etc. at the time.

Further, in the configuration in which the active layer C8 is included in the mesa stripe portion Cme and the path through which the current flows is narrowed to a narrow range of the width W1, unintended changes in output characteristics such as kink in the laser characteristics of the semiconductor laser apparatus occur. It can be prevented from occurring. Further, by embedding both side surfaces of the active layer C8 with the embedded layer Cbo in this way, it is possible to suppress the leakage current leaking from the active layer C8 to both lateral X sides of the semiconductor laser element C. Further, since the groove portion M is provided so as to sandwich the active layer C8, the leakage current leaking from the active layer C8 in both lateral directions X can be further suppressed by this configuration as well.

As described above, the mesa stripe portion Cme including the active layer C8, the embedded layer Cbo, and the groove portion M in the present embodiment have the effect of improving the output characteristics in the semiconductor laser device and the active layer at the time of joining the stud bump 11 and the wire 3. It has both the effect of reducing damage to C8 and the effect of both.
The leakage current suppression effect by providing the embedded layer Cbo and the groove portion M as described above can be similarly obtained in the waveguide portions 20A and 20B and the modulator portion 30.

Here, in the semiconductor laser element C, the stud bump 11 is provided only in the DFB laser unit 10 and is not provided in the modulator unit 30. This is because in the electric field absorption type modulator integrated semiconductor laser (EML-LD) formed by integrating the DFB laser unit 10 and the modulator unit 30, the electrode area in the DFB laser unit has the frequency characteristic of the laser beam. This is because it does not affect it. Therefore, the stud bump 11 that increases the electrode area is provided only in the DFB laser unit 10. On the other hand, when the electrode area in the modulator unit 30 is increased by the stud bump, the capacitance increases in proportion to the surface area thereof, and the frequency characteristic deteriorates. In this way, by configuring the stud bump 11 not to be provided in the modulator unit 30, the element capacitance such as the parasitic capacitance in the modulator unit 30 can be reduced, and the speed and capacity in optical communication using the semiconductor laser device 100 can be increased. It is possible to cope with the change.

Hereinafter, other configuration examples of the semiconductor laser device C will be described with reference to FIGS. 8 and 9.
FIG. 8 is a cross-sectional view showing the configuration of the semiconductor laser device Cex1 having a configuration different from that of the semiconductor laser device C shown in FIG.
As shown in FIG. 8, the active layer C8 is not included in the mesa-shaped mesa-stripe portion, is located on the downward Y2 side of the mesa-stripe portion, and has the same lateral X width as the electrode C1. good.

Also in this case, the active layer C8, which is a heat source, is formed in the semiconductor laser element C at a position closer to the electrode C1 on the upward Y1 side than the electrode C10 side on the downward Y2 side of the semiconductor laser element C. , High heat dissipation can be obtained. Further, also in this configuration, if the length of the p-type clad layer C4-2 in the thickness direction Y is appropriately adjusted, damage at the time of joining the stud bump 11 formed on the electrode C1 on the upward Y1 side of the active layer C8 is damaged. The active layer C8 can be protected from.
Further, the opening Cop of the insulating layer C2 narrows the inlet for supplying the current to the active layer C8 only to the connection portion P2 above the active layer C8, and the groove M is provided so that the outside of the groove M is provided. It is possible to suppress the leakage current that leaks to.

FIG. 9 is a cross-sectional view showing the configuration of the semiconductor laser device C1ex2 having a configuration different from that of the semiconductor laser device C shown in FIG.
As shown in FIG. 9, both side surfaces of the mesa stripe portion Cme including the active layer C8 are in contact with the insulating layer C2. In this way, both sides of the active layer C8 may not be embedded by the embedded layer Cbo.
Even in this case, the active layer C8, which is a heat source, is formed in the semiconductor laser element C at a position closer to the electrode C1 on the upward Y1 side than the electrode C10 side on the downward Y2 side of the semiconductor laser element C. , High heat dissipation can be obtained.
Further, since both sides of the mesa stripe portion Cme are in contact with the insulating layer C2 and the groove portion M is provided, the leakage current leaking from the active layer C8 in both lateral directions X of the semiconductor laser element C can be suppressed.

Further, in addition to the semiconductor laser elements Cex1 and Cex2, similar structures such as a structure in which the diffraction grating C7 is formed on the downward Y2 side of the active layer C8 and a structure in which the groove M does not exist are also assumed.

In the present embodiment, the stud bump 11 has been described as an example as a protrusion for increasing the heat capacity and the surface area of the electrode C1, but the present invention is not limited thereto. A protrusion having any configuration can be used as long as the heat capacity and surface area of the electrode C1 can be increased. For example, it is assumed that a bump, a pillar bump, a solder bump, or a solder ball formed by plating is used as the protrusion. ing.

Further, the number of stud bumps 11 and the number of rows on the electrode C1 are not particularly limited, and may be adjusted according to the device length in the vertical direction Z and the device width in the horizontal direction X of the semiconductor laser element C. Further, as a matter of course, when the stud bump 11 is formed on the electrode C1, the more the number of wire bonding by the ultrasonic wave is repeated, the more the semiconductor laser element C may be damaged by the ultrasonic wave, and a defect may occur. .. Therefore, it is advisable to form only the minimum number of stud bumps that can secure the desired heat dissipation.

Further, in the above description, the case where the first conductive type is n type and the second conductive type is p type has been exemplified, but the first conductive type may be p type and the second conductive type may be n type. .. That is, the semiconductor substrate formed on the submount side of the active layer may be a p-type semiconductor substrate, and the semiconductor layer formed above the active layer may be an n-type semiconductor substrate.

If a problem occurs during the formation of the stud bump 11 and the stud bump 11 is not completely bonded on the electrode C1, the stud bump 11 is reduced in the bonding area between the semiconductor laser element C and the electrode C1. Peeling may occur. In this case, when the separated stud bumps 11 come into contact with each other when the distances between the stud bumps 11 are close to each other, an unexpected circuit (current path) may be formed due to this contact. Therefore, it is preferable to provide a set separation distance between the stud bumps 11 so that the stud bumps 11 do not come into contact with each other and are independent of each other. Further, by making each stud bump 11 independent, the surface area of the stud bump 11 can be maximized, and further, it is possible to secure an interval between the independent stud bumps 11 so that, for example, a cooling fluid can pass smoothly. Therefore, efficient heat exchange and heat dissipation are possible.

In the semiconductor laser apparatus of the present embodiment configured as described above,
It is a semiconductor laser device including a laser unit that emits laser light and a modulator unit that modulates the laser light emitted from the laser unit, and the laser unit and the modulator unit are integrated in a submount. hand,
The laser portion includes a first electrode layer that abuts on a surface of the submount on the first direction side in the thickness direction and is connected to the submount.
A first conductive semiconductor layer provided on the first direction side of the first electrode layer,
The active layer provided on the first direction side of the first conductive semiconductor layer and
A second conductive semiconductor layer provided on the first direction side of the active layer, and
A second electrode layer provided on the first direction side of the second conductive semiconductor layer is provided.
The length of the first conductive semiconductor layer in the thickness direction is formed to have a length L1 in which the stress in the active layer applied from the first electrode layer side is equal to or less than the set first value. The length of the second conductive semiconductor layer in the thickness direction is formed to be a length L2 shorter than the length L1 of the first conductive semiconductor layer.
On the second electrode layer, a protrusion is provided that protrudes from the second electrode layer toward the first direction, and the protrusion supplies a current to the active layer via the second electrode layer. 1 Provided away from the connection line,
It is a thing.

As described above, the length of the second conductive semiconductor layer (p-type clad layers C4-1, C4-2, p-type contact layer C3) provided on the first direction (upward) side of the active layer in the thickness direction Y. L2 is formed to have a length shorter than the length L1 of the first conductive semiconductor layer (substrate C9). That is, the active layer serving as a heat source is the first in the semiconductor laser element on the first direction (upward) side of the semiconductor laser element on the first electrode layer (electrode C10) side on the second direction (downward) side. 2 Arranged at a position close to the electrode layer (electrode C1). As a result, the heat generated in the active layer is more transferred to the electrode C1 on the upward side near the active layer.

Then, on the second electrode layer (electrode C1) close to the active layer, a protruding portion protruding in the first direction (upward direction) so as to increase the heat capacity and surface area of the second electrode layer (electrode C1). (Stud bump) is provided. As described above, the heat capacity increased by the stud bumps transfers heat more efficiently to the electrode C1 side, and the surface area of the electrode C1 also increased by the stud bumps radiates heat efficiently. In this way, heat dissipation from the electrode C1 of the semiconductor element is promoted, and high heat dissipation can be ensured.

Further, since the first electrode layer (electrode C10) far from the active layer is connected to the submount, the submount is not soldered to the second electrode layer (electrode C1) close to the active layer. As a result, the stress caused by soldering the submount is not applied to the active layer from the electrode C1 side close to the active layer.

Further, the length L1 in the thickness direction of the first conductive semiconductor layer (substrate C9) on the second direction (downward) side of the active layer is from the first electrode layer (electrode C10) side bonded to this submount. It is formed so as to secure a length in which the stress in the applied active layer is equal to or less than the set first value.
By configuring the stress in the active layer to be equal to or less than the first allowable range value in this way, it is possible to prevent the active layer from being distorted and causing wavelength skipping of the laser beam, resulting in high performance. A semiconductor laser device can be obtained.

Further, the protrusion (stud bump) is provided apart from the first connecting wire (wire) that supplies an electric current to the active layer. As a result, the current supplied to the active layer via the wire can be prevented from flowing through an unintended path through the stud bump, so that the performance of the semiconductor laser device can be ensured.

As described above, the semiconductor laser device of the present embodiment has both high performance by reducing stress applied to the active layer and an effect of improving heat dissipation.

Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
Two grooves recessed in the second direction side opposite to the first direction from the surface on the first direction side of the second electrode layer are perpendicular to the thickness direction with a set first distance. Formed by stretching in the third direction,
An insulating layer is formed between the second electrode layer and the second conductive semiconductor layer, and the insulating layer has a first opening formed by stretching in the third direction between the grooves. ,
The protrusion is formed at a position on the outside of the groove, which is a position opposite to the side on which the first opening is located with the groove interposed therebetween.
It is a thing.

In this way, two groove portions extending in the third direction (longitudinal direction) are formed on the second electrode layer (electrode C1). Then, a first opening is formed in the insulating layer between the two grooves. In this way, the inlet for supplying the current to the active layer is narrowed to the region between the two grooves. On top of that, a protrusion (stud bump) is formed on the outside of the groove on the side opposite to the side on which the first opening is located with the groove in between.
As a result, the portion of the active layer where light emission is generated can be separated from the stud bump. As described above, by further interposing a groove between the stud bump and the portion where the light emission of the active layer is generated, the creepage distance between the stud bumps can be further secured. In this way, it is possible to protect the portion where the active layer emits light from damage caused by ultrasonic vibration, heat, etc. at the time of joining the stud bump.

Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
The cross section in the thickness direction has a mesa-shaped shape, and the first mesa stripe portion including the first conductive semiconductor layer and the active layer and extending in the third direction is provided.
The first mesa stripe portion is formed between the grooves and is formed.
The protrusion is formed at a position outside the groove at a distance of a second distance or more set from the active layer.
It is a thing.

As described above, the active layer is configured to be contained in the first mesa stripe portion formed between the two grooves. Then, the protruding portion (stud bump) is formed at a position outside the groove portion so as to be separated from the active layer by a set second distance or more. In this way, by securing a second distance between the active layer and the stud bump and further interposing a groove portion between them, it is caused by ultrasonic vibration, heat, etc. at the time of joining the stud bump. The active layer can be reliably protected from damage.

Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
Embedded layers, which are semiconductor layers, are formed on both side surfaces of the first mesa stripe portion.
It is a thing.

In this way, semiconductor layers are formed on both side surfaces of the first mesa stripe portion. That is, both side surfaces of the active layer included in the first mesa stripe portion are embedded by the semiconductor layer having high thermal conductivity. As a result, the heat generated in the active layer can be efficiently transferred to the stud bumps via the semiconductor layer, and the heat dissipation effect can be improved.
Further, in this way, even when a groove is provided between the active layer and the stud bump for the purpose of protecting the active layer from damage at the time of joining the stud bump, the active layer is thus a semiconductor layer having high thermal conductivity. By embedding the heat in the active layer, the heat generated in the active layer can be efficiently applied to the stud bump regardless of the presence or absence of the groove.

Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
The protrusion is made of the same material as the material constituting the first connecting line.
It is a thing.
Further, the method for manufacturing the semiconductor laser device of the present embodiment configured as described above is described.
The wire material is melted by a wire bonding device, and the first connection line is wired.
The wire material is melted by the wire bonding device to form the protrusion.
It is a thing.

As described above, the protrusion (stud bump) is made of the same material as the material constituting the first connecting wire (wire). That is, the wire material used for the first connecting wire (wire) that contributes to the electric circuit for supplying the current to the active layer is also used in the formation of the protrusion (stud bump). As described above, since the stud bump in which the wire is melted is used instead of the configuration in which the component such as the heat sink is separately used as the protruding portion, the cost of the additional component such as the heat sink becomes unnecessary.

In the mass production of semiconductor devices, where prices are falling sharply and continuous cost reduction is required, it is clear that the additional cost of parts for one heat sink for one element will be a major obstacle. Therefore, by using the wire material essential for the manufacture of the semiconductor laser device also in the formation of the stud bumps, it is possible to significantly reduce the cost.

As described above, the formation can be completed by the components constituting the semiconductor laser device without the need for additional parts such as a heat sink as the protrusions and without depending on the components other than the semiconductor laser device. Therefore, it is also effective in the sales business of finished chip products that sell only semiconductor laser devices.
Further, since the parts such as the heat sink are not bonded to the second electrode layer (electrode C1) on the Y1 side in the first direction (upward direction) of the semiconductor element, the heat sink and the second electrode layer (electrode C1) of the semiconductor laser element are used. It is possible to prevent a defect caused by the inability to obtain the height adjustment accuracy of the semiconductor laser element or a poor contact between the heat sink and the second electrode layer (electrode C1) of the semiconductor laser element.

Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
The length L1 of the first conductive semiconductor layer is formed to be 80 μm or more and 130 μm or less.
It is a thing.

As described above, the stress applied to the active layer by setting the length in the thickness direction of the first conductive semiconductor layer (substrate C9) provided on the submount side from the active layer to 80 μm or more and 130 μm or less. It is possible to suppress cracking, chipping, burrs, etc. of the semiconductor element during manufacturing while reducing the stress. As a result, the yield of the semiconductor element can be improved and the productivity can be improved.

Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
The modulator unit is arranged side by side with the laser unit in the same submount.
The first conductive semiconductor layer and the second conductive semiconductor layer in the laser section are stretched from the laser section and formed in the modulator section.
The modulator section is
A third electrode layer that abuts on the surface of the submount on the first direction side and is connected to the submount and is formed on the second direction side of the first conductive semiconductor layer that contradicts the first direction. When,
A fourth electrode layer provided on the first direction side of the second conductive semiconductor layer, and a fourth electrode layer.
It is provided between the first conductive type semiconductor layer and the second conductive type semiconductor layer, is connected to the active layer in the laser portion, and is applied between the third electrode layer and the fourth electrode layer. A light absorption layer that absorbs light emitted from the laser unit according to a voltage is provided.
It is a thing.

In this way, the first conductive semiconductor layer (substrate C9) and the second conductive semiconductor layer (p-type clad layers C4-1, C4-2, p-type contact layer C3) in the laser unit (DFB laser unit) are formed. , It is also formed in the modulator section by extending from the laser section (DFB laser section).
In this way, the heat generated by the photocurrent or the like in the light absorption layer of the modulator section is also transferred to the p-type clad layers C4-1, C4-2, and p-type contact layer C3 on the upper side of the light absorption layer, and is transferred to the DFB. Heat can be dissipated from the stud bump of the laser part. Further, the stress applied to the light absorption layer from the third electrode (electrode C10EA) side bonded to the submount can be reduced, and the effect of improving the yield at the time of manufacturing can be obtained.

Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
The groove portion and the insulating layer in the laser portion are extended from the laser portion to be formed in the modulator portion.
The groove portion in the modulator portion is recessed in the second direction side from the surface on the first direction side of the fourth electrode layer, and is extended in the third direction with a distance of the first distance set from each other. Formed,
The insulating layer is formed between the fourth electrode layer and the second conductive semiconductor layer, and the insulating layer has a second opening formed by stretching in the third direction between the grooves. ,
It is a thing.
Further, in the semiconductor laser apparatus of the present embodiment configured as described above,
The modulator section is
The cross section in the thickness direction has a mesa-shaped shape, and the second mesa stripe portion including the first conductive semiconductor layer and the light absorption layer and extending in the third direction is provided.
The second mesa stripe portion is formed between the grooves.
It is a thing.

Further, in this way, also in the modulator section, by providing the groove portion, the opening of the insulating layer formed between the groove portions, and the mesa stripe portion, the current that suppresses the leakage current similar to the DFB laser portion. It is possible to obtain a confinement effect, an effect of improving heat dissipation, and an effect of improving productivity.

It should be noted that when the groove portion is formed in the DFB laser portion, the modulator portion is not limited to the semiconductor laser element having the same configuration in which the groove portion is formed. For example, the semiconductor element may have a configuration in which a groove portion is formed in the DFB laser portion, but may have a configuration in which the groove portion is not formed in the modulator portion. Alternatively, the DFB laser unit may be configured not to form an embedded layer, while the modulator unit may be configured to form an embedded layer.
The combination of the groove, the mesa stripe portion, and the configuration in which the active layer is embedded by the embedded layer or the insulating film can be arbitrarily combined in each of the DFB laser portion and the modulator portion.

Embodiment 2.
Hereinafter, the second embodiment of the present application will be described with reference to the parts different from the first embodiment. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
FIG. 10 is a top view showing a schematic configuration of the semiconductor laser diode device 200 according to the second embodiment.
FIG. 11 is a cross-sectional view of the semiconductor laser device 200 shown in FIG. 1 taken along the line AA'.
FIG. 12 is a side view of the semiconductor laser device 200 shown in FIG. 1 as viewed from the direction of arrow B.

In the second embodiment, instead of the stud bump 11 of the first embodiment, a wire configured on the electrode C1 on the active layer side of the semiconductor laser device C as a protruding portion contributing only to heat dissipation by a second connecting wire. A bridge 211 is provided. In this wire bridge 211, the first end and the second end of the second connection line are connected to the electrode C1 with a set third distance H3-1, H3-2, or more. It is wired and configured. As shown in FIG. 12, the intermediate portion between the first end and the second end of the second connecting line forming the wire bridge 211 has a gap G between the surface of the electrode C1 on the upward Y1 side. is doing. In this way, the wire bridge 211 is formed in the shape of a bridge protruding toward the upward Y1 side of the electrode C1.

The wire bridge 211 is wired in the electrode C1 of the DFB laser unit 10 after the semiconductor laser element C is die-bonded to the submount 1 and then the wire 3 is wired. At this time, the wire bridge 211 that contributes only to the heat dissipation is wired so as not to interfere with the wiring of the wire 3 contributing to the electric circuit and not to come into contact with the wire bridge 211. Further, the position of the wire 3 in the electrode C1 is arbitrarily and preferentially determined, and the wiring of the wire bridge 211 that contributes only to heat dissipation is changed or adjusted depending on the position of the wire 3 that contributes to this electric circuit.

Hereinafter, other wiring examples of the wire bridge 211 in the DFB laser unit 10 will be described with reference to FIGS. 13 and 14.
FIG. 13 is a schematic top view of the electrode C1ex1 showing an example of the wiring of the wire bridge 211 in the DFB laser unit 10 of the present embodiment.
FIG. 14 is a schematic top view of the electrode C1ex2 showing an example of the wiring of the wire bridge 211 in the DFB laser unit 10 of the present embodiment.
FIG. 15 is a schematic top view of the electrode C1ex3 showing an example of wiring of the wire bridge 211 in the DFB laser unit 10 of the present embodiment.
FIG. 16 is a schematic top view of the electrode C1ex4 showing an example of the wiring of the wire bridge 211 in the DFB laser unit 10 of the present embodiment.

As will be described below, the length, number, combination, and wiring position of the wire bridges 211 to be wired shall vary depending on the size of the semiconductor laser element C.
For example, in the configuration shown in FIG. 13, it is assumed that the wire bridge 211 is wired in the vertical direction Z parallel to the groove portion M on both outer sides of the horizontal direction X of the groove portion M so as not to straddle the groove portion M. ing.

As shown in FIG. 13, when the length ZL from the front end surface to the rear end surface of the semiconductor laser element C in the vertical direction Z is longer than the width XL of the semiconductor laser element C in the lateral direction X, the wire bridge is thus formed. By arranging the 211, it is possible to form a long wire bridge 211 as compared with a configuration in which the wire bridge 211 in the lateral direction X is formed across the groove M. As a result, the number of times of wire bonding connecting the first end and the second end of the wire can be reduced. With this small amount of wire bonding, more heat capacity can be obtained and high heat dissipation can be ensured, and damage to the semiconductor laser element C at the time of wire bonding can be reduced.

Further, in the configuration shown in FIG. 14, it is assumed that the width XL of the semiconductor laser element C is longer than the length ZL from the front end surface to the rear end surface of the semiconductor laser element C. In this case, for example, as shown in FIG. 14, it is better to form the wire bridge 211 wired in the lateral direction X so as to straddle the groove portion M, so that more heat capacity can be obtained by less wire bonding, and the wire can be obtained. Damage to the semiconductor laser element C at the time of bonding can be reduced.

Further, as shown in FIG. 15, even when the length ZL from the front end surface to the rear end surface of the semiconductor laser element C in the vertical direction Z is longer than the width XL of the semiconductor laser element C in the lateral direction X, the electrode C1 When the wire bridge 211 is formed diagonally in the above, the most heat capacity can be obtained and it is effective in the configuration using one wire bridge 211.

However, when the wire bridge 211 is formed diagonally, a problem may occur due to contact with the wire 3 that contributes to the initially formed electric circuit, or the wire bridge 211 may be wired above the wire 3. The height of the wire may be unexpectedly high. Therefore, when wiring two or more wire bridges 211 and wiring the wire 3 contributing to the electric circuit and the wire bridge 211 in the vicinity, the wire bridge 211 crosses with another wire bridge 211 or wire 3. It is preferable not to do so.

Further, as shown in FIG. 16, a configuration can be assumed in which bumps such as the stud bump 11 described in the first embodiment are used in combination.

In order to increase the heat capacity of the wire bridge 211, it is effective to maximize the volume of the wire bridge 211. Therefore, the wire material forming the wire bridge 211 is preferably as thick as possible. However, if the wire material is too thick, high energy is required at the time of wire bonding, which causes a problem in the semiconductor laser device C. Generally, the dimensions of the semiconductor laser element C are assumed to be lateral X: 100 μm to 200 μm × vertical Z: several 100 μm. Therefore, in the present embodiment, the length of the wire seen from the upper surface is 1000 μm or less. Limited to.
Further, the wire diameter of the wire material used is also limited to 10 μm to 80 μm, which is assumed with respect to the dimensions of the semiconductor laser device C.
Further, the height of the wire bridge 211 that contributes only to heat dissipation and the height of the wire 3 that contributes to the electric circuit in the thickness direction Y is not limited, but it may cause the wire to come off in the subsequent assembly process and cause an unexpected short circuit. Therefore, it is basically desirable to keep the height as low as possible when wiring.

In the semiconductor laser apparatus of the present embodiment configured as described above,
The first end and the second end are formed by a second connecting line connected to the second electrode layer, respectively, and an intermediate portion between the first end and the second end of the second connecting line. Is wired in a bridge shape so as to have a gap between the second electrode layer and the second electrode layer.
It is a thing.

As a result, the same effect as that of the first embodiment can be obtained, high heat dissipation can be ensured, and a high-performance semiconductor laser device and a method for manufacturing the semiconductor laser device can be obtained.
Further, as described above, the protruding portion (wire bridge) is formed by a second connecting line in which the first end and the second end are connected to each other on the second electrode layer (electrode C1). Then, the intermediate portion between the first end and the second end of the second connection line is wired so as to have a gap between the second electrode layer (electrode C1) and the connection start point (first end). ) And the connection end point (second end) are both connected on the second electrode layer to form a bridge-shaped wire bridge.
As a result, the heat capacity, surface area, number of wire bonding, and the like of the protruding portion can be adjusted according to the length from the front end surface to the rear end surface of the semiconductor laser element and the width in the lateral direction. In this way, in the semiconductor laser device, higher heat dissipation can be ensured and damage to the semiconductor element can be reduced.

Embodiment 3.
Hereinafter, the third embodiment of the present application will be described with reference to the parts different from the first embodiment. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
FIG. 17 is a top view showing a schematic configuration of the semiconductor laser diode device 300 according to the third embodiment.
FIG. 18 is a cross-sectional view taken along the line AA'of the semiconductor laser device 300 shown in FIG.
FIG. 19 is a side view of the semiconductor laser device 300 shown in FIG. 17 as viewed from the direction of arrow B.

In the third embodiment, in the semiconductor laser apparatus 200 shown in the second embodiment, the position of the uppermost portion 211max in the thickness direction Y of the wire bridge 211 that contributes only to heat dissipation is set to the uppermost portion of the wire 3 that contributes to the electric circuit. Wire so that it is higher than the 3max position. Further, a pillar portion 312 is provided on the sub mount 1 so as to stand on the Y1 side in the upward direction.

The height Yh of the pillar portion 312 in the thickness direction Y is higher than the uppermost portion 3max of the wire 3 contributing to the electric circuit and lower than the uppermost portion 211max of the wire bridge 211 contributing only to heat dissipation. Then, the heat radiating plate 313 as the heat radiating body is arranged so as to be supported by the end portion on the upward Y1 side of the pillar portion 312 on the upward Y1 side of the wire bridge 211 that contributes only to heat radiating. As a result, the heat sink 313 pushes the wire bridge 211 downward to the Y2 side, so that the uppermost portion 211max of the wire bridge 211 and the heat sink 313 are in contact with each other and are not in contact with the uppermost portion 3max of the wire 3. .. The heat radiating plate 313 is thus joined to and fixed to the sub mount 1 via a pillar portion 312 provided between the heat radiating plate 313 and the sub mount 1.

Although the configuration in which only one pillar portion 312 is arranged is shown in the figure, a plurality of pillar portions 312 may be provided depending on the shape, heat capacity, etc. of the heat radiating plate 313.
Further, since the wire bridge 211 that contributes only to heat dissipation is basically cylindrical, it is expected that the contact area with the heat dissipation plate is small. In order to solve this problem, thermal paste 314 is applied to the surface of the heat sink 313 on the downward Y2 side before the wire bridge 211 is brought into contact with the pillar portion 312. The thermal paste 314 is assumed to be printed on the heat sink by screen printing. The heat sink 313 is supposed to be printed after the thermal paste 314 is printed, but by using a technique that can print within a small area of 1 mm x 1 mm, the heat sink is cut and then the thermal paste 314 is printed. It is also possible to do this.

Further, the heat radiating plate 313 and the pillar portion 312 are assumed to be materials having excellent thermal conductivity. For example, all metal materials such as Al (aluminium) material and Ag (argentum) material, and materials similar to submount 1 are used. Therefore, for example, an aluminum nitride (AlN) substrate, an alumina (Al2O3), or the like is assumed.

The semiconductor laser device of the present embodiment configured as described above is
The first connecting line is wired so as not to exceed the highest portion of the second connecting line having the highest height from the second electrode layer.
The sub-mount is provided with a pillar portion that stands on the first direction side from the surface on the first direction side.
The radiator is supported and arranged by the pillar portion on the first direction side of the second connecting line.
The length of the pillar portion in the thickness direction is such that the radiator pushes down the highest portion of the second connecting wire toward the second direction side so that the second connecting wire and the radiator come into contact with each other. It is formed to a length that does not come into contact with the first connecting line.
It is a thing.

As a result, the same effect as that of the first embodiment can be obtained, high heat dissipation can be ensured, and a high-performance semiconductor laser device and a method for manufacturing the semiconductor laser device can be obtained.
In this way, the first connecting line (wire) that contributes to the electric circuit is wired so as not to exceed the highest portion, which is the highest point of the second connecting line (wire bridge) that does not contribute to the electric circuit. On top of that, the radiator (radiator plate) supported by the pillars erected on the submount pushes down the highest part of the second connection line (wire bridge) that does not contribute to the electric circuit, and also the electric circuit. It is arranged so as not to come into contact with the first connecting wire (wire) that contributes to.

In this way, a heat radiating body (heat radiating plate) having excellent thermal conductivity is provided, which is joined to the sub mount via the pillar portion. Then, a second connecting wire (wire bridge) as a protruding portion that contributes only to heat dissipation is brought into contact with the radiator (heat sink). As a result, the heat dissipation of the wire bridge can be improved, and the heat dissipation from the electrode C1 on the upward Y1 side of the active layer can be further improved. Further, since the pillar portion is joined to the sub mount, a heat dissipation effect can be obtained by transferring heat to the sub mount side via the pillar portion.

Further, instead of directly joining the semiconductor element to the heat sink or the like with solder, a second bridge-shaped bridge having a cushioning property, which is wired in a bridge shape so as to have a gap between the semiconductor element and the second electrode layer (electrode C1). The highest part of the connection line (wire bridge) is in contact with the radiator (heat sink).
As a result, even if a heat sink is used, the stress caused by the adhesive or the like for joining the heat sink can be absorbed by the wire bridge and not added to the active layer of the semiconductor laser device. As a result, it is possible to prevent problems such as wavelength skipping and improve the performance of the semiconductor laser device.

Furthermore, since the wire bridge that is in contact with the heat sink and contributes only to heat dissipation has a cushioning shape like this, the height control when installing the heat sink is as direct as the number of wires that make up the wire bridge. Only requires the accuracy of. Therefore, it is possible to prevent poor contact between the heat radiating plate and the semiconductor laser element, prevent the semiconductor laser element from malfunctioning due to contact with the heat radiating plate, and further simplify the manufacturing process.

Further, the length of the column portion in the thickness direction is formed so that the radiator does not come into contact with the wire contributing to the electric circuit, so that the current supplied to the active layer via the wire is increased. It is possible to prevent the current from flowing through an unintended path through the radiator, and the performance of the semiconductor laser device can be ensured.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the art disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 submount, 3 wires (1st connection line), 11 stud bumps (protruding part),
10 laser unit, 30 modulator unit, 100, 200, 300 semiconductor laser device,
211 Wire bridge (protruding part), 312 pillar part, 313 heat sink (heat sink),
C1 electrode (first electrode layer), C1EA electrode (third electrode layer), C2 insulating layer,
C3 p-type contact layer (second conductive semiconductor layer),
C4-1 p-type clad layer (second conductive semiconductor layer),
C4-2 p-type clad layer (second conductive semiconductor layer),
C5 p-type block layer (embedded layer), C6 n-type block layer (embedded layer),
C8 active layer, C9 substrate (first conductive semiconductor layer), C10 electrode (second electrode layer),
C10EA electrode (4th electrode layer), Cme 1st mesa stripe,
CmeEA 2nd mesa stripe, Cbo embedded layer,
Cop opening (first opening).

Claims (13)

It is a semiconductor laser device including a laser unit that emits laser light and a modulator unit that modulates the laser light emitted from the laser unit, and the laser unit and the modulator unit are integrated in a submount. hand,
The laser portion includes a first electrode layer that abuts on a surface of the submount on the first direction side in the thickness direction and is connected to the submount.
A first conductive semiconductor layer provided on the first direction side of the first electrode layer,
The active layer provided on the first direction side of the first conductive semiconductor layer and
A second conductive semiconductor layer provided on the first direction side of the active layer, and
A second electrode layer provided on the first direction side of the second conductive semiconductor layer is provided.
The length of the first conductive semiconductor layer in the thickness direction is formed to have a length L1 in which the stress in the active layer applied from the first electrode layer side is equal to or less than the set first value. The length of the second conductive semiconductor layer in the thickness direction is formed to be a length L2 shorter than the length L1 of the first conductive semiconductor layer.
On the second electrode layer, a protrusion is provided that protrudes from the second electrode layer toward the first direction, and the protrusion supplies a current to the active layer via the second electrode layer. 1 Provided away from the connection line,
Semiconductor laser device. Two grooves recessed in the second direction side opposite to the first direction from the surface on the first direction side of the second electrode layer are perpendicular to the thickness direction with a set first distance. Formed by stretching in the third direction,
An insulating layer is formed between the second electrode layer and the second conductive semiconductor layer, and the insulating layer has a first opening formed by stretching in the third direction between the grooves. ,
The protrusion is formed at a position on the outside of the groove, which is a position opposite to the side on which the first opening is located with the groove interposed therebetween.
The semiconductor laser device according to claim 1. The cross section in the thickness direction has a mesa-shaped shape, and the first mesa stripe portion including the first conductive semiconductor layer and the active layer and extending in the third direction is provided.
The first mesa stripe portion is formed between the grooves and is formed.
The protrusion is formed at a position outside the groove at a distance of a second distance or more set from the active layer.
The semiconductor laser device according to claim 2. Embedded layers, which are semiconductor layers, are formed on both side surfaces of the first mesa stripe portion.
The semiconductor laser device according to claim 3. The protrusion is made of the same material as the material constituting the first connecting line.
The semiconductor laser device according to any one of claims 2 to 4. The length L1 of the first conductive semiconductor layer is formed to be 80 μm or more and 130 μm or less.
The semiconductor laser device according to any one of claims 2 to 5. The protrusion is
The first end and the second end are formed by a second connecting line connected to the second electrode layer, respectively, and an intermediate portion between the first end and the second end of the second connecting line. Is wired in a bridge shape so as to have a gap between the second electrode layer and the second electrode layer.
The semiconductor laser device according to any one of claims 2 to 6. The radiator is provided with a radiator that is disposed without contacting the first connecting line and in contact with the second connecting line.
The semiconductor laser device according to claim 7. The first connecting line is wired so as not to exceed the highest portion of the second connecting line having the highest height from the second electrode layer.
The sub-mount is provided with a pillar portion that stands on the first direction side from the surface on the first direction side.
The radiator is supported and arranged by the pillar portion on the first direction side of the second connecting line.
The length of the pillar portion in the thickness direction is such that the radiator pushes down the highest portion of the second connecting wire toward the second direction side so that the second connecting wire and the radiator come into contact with each other. It is formed to a length that does not come into contact with the first connecting line.
The semiconductor laser device according to claim 8. The modulator unit is arranged side by side with the laser unit in the same submount.
The first conductive semiconductor layer and the second conductive semiconductor layer in the laser section are stretched from the laser section and formed in the modulator section.
The modulator section is
A third electrode layer that abuts on the surface of the submount on the first direction side and is connected to the submount and is formed on the second direction side of the first conductive semiconductor layer that contradicts the first direction. When,
A fourth electrode layer provided on the first direction side of the second conductive semiconductor layer, and a fourth electrode layer.
It is provided between the first conductive type semiconductor layer and the second conductive type semiconductor layer, is connected to the active layer in the laser portion, and is applied between the third electrode layer and the fourth electrode layer. A light absorption layer that absorbs light emitted from the laser unit according to a voltage is provided.
The semiconductor laser device according to any one of claims 2 to 9. The groove portion and the insulating layer in the laser portion are extended from the laser portion to be formed in the modulator portion.
The groove portion in the modulator portion is recessed in the second direction side from the surface on the first direction side of the fourth electrode layer, and is extended in the third direction with a distance of the first distance set from each other. Formed,
The insulating layer is formed between the fourth electrode layer and the second conductive semiconductor layer, and the insulating layer has a second opening formed by stretching in the third direction between the grooves. ,
The semiconductor laser device according to claim 10. The modulator section is
The cross section in the thickness direction has a mesa-shaped shape, and the second mesa stripe portion including the first conductive semiconductor layer and the light absorption layer and extending in the third direction is provided.
The second mesa stripe portion is formed between the grooves.
The semiconductor laser device according to claim 11. The method for manufacturing a semiconductor laser device according to any one of claims 1 to 12.
The wire material is melted by a wire bonding device, and the first connection line is wired.
The wire material is melted by the wire bonding device to form the protrusion.
A method for manufacturing a semiconductor laser device.

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