JP7220156B2 - Submount and semiconductor laser device - Google Patents

Description

The present disclosure relates to a submount and a semiconductor laser device including the submount.

A submount is known for supporting a semiconductor laser element (laser diode or the like) that forms the main part of a semiconductor laser device.

A submount is provided according to a first aspect of the present disclosure. The submount includes a substrate, an insulating layer, and a conductive layer. The substrate has a main surface facing the thickness direction and is made of a single crystal semiconductor material. The insulating layer has electrical insulating properties and covers at least a portion of the main surface. The conductive layer is disposed over the insulating layer. The semiconductor material is silicon carbide of the first conductivity type.

According to a second aspect of the present disclosure, a submount according to the first aspect of the present disclosure further comprising the metal layer and a submount for emitting laser light and electrically bonded to the conductive layer of the submount. A semiconductor laser element, a metal stem that supports the submount so that the thickness direction of the base material of the submount is perpendicular to the direction of emission of the laser light, and the emission direction from the stem. a first lead and a second lead which have sections protruding on opposite sides of the submount and are supported on the stem while being spaced apart from each other, the first lead being attached to the conductive layer of the submount. A semiconductor laser device is provided, wherein the second lead is electrically connected to the semiconductor laser element.

According to a third aspect of the present disclosure, a submount according to the first aspect of the present disclosure further comprising the metal layer, the first pad and the second pad; a semiconductor laser element electrically bonded to the conductive layer; and a metallic support for supporting the submount such that the thickness direction of the base material of the submount is orthogonal to the laser light emission direction. a stem; and a first lead and a second lead which both have sections protruding from the stem in a direction opposite to the emitting direction and are supported by the stem while being spaced apart from each other, wherein the first lead is conductive to both the conductive layer of the submount and the second pad, and the second lead is conductive to both the semiconductor laser element and the first pad; A semiconductor laser device is provided.

Other features and advantages of the present disclosure will become more apparent from the detailed description provided below with reference to the accompanying drawings.

1 is a perspective view of a first embodiment of a submount according to the first aspect of the disclosure; FIG. FIG. 2 is a plan view of the submount shown in FIG. 1; 2 is a bottom view of the submount shown in FIG. 1; FIG. 3 is a cross-sectional view taken along line IV-IV of FIG. 2; FIG. FIG. 3 is a cross-sectional view taken along line VV of FIG. 2; FIG. 4 is a perspective view of a second embodiment of a submount according to the first aspect of the disclosure; FIG. 7 is a plan view of the submount shown in FIG. 6; FIG. 8 is a cross-sectional view along line VIII-VIII of FIG. 7; FIG. 8 is a cross-sectional view along line IX-IX of FIG. 7; 1 is a perspective view (transmitted through a transparent plate of a cap) according to a first embodiment of a semiconductor laser device according to a second aspect of the present disclosure; FIG. FIG. 11 is a plan view (through the cap) of the semiconductor laser device shown in FIG. 10; 12 is a cross-sectional view along line XII-XII of FIG. 11; FIG. FIG. 12 is a cross-sectional view along line XIII-XIII of FIG. 11; FIG. 14 is a partially enlarged view of FIG. 13; FIG. 4 is a cross-sectional view of a second embodiment of a semiconductor laser device according to a second aspect of the present disclosure; FIG. 16 is a partially enlarged view of FIG. 15;

A mode for carrying out the present disclosure (hereinafter referred to as "embodiment") will be described with reference to the accompanying drawings.

<Submount>
As submounts according to the first aspect of the present disclosure, a submount A10 as the first embodiment and a submount A20 as the second embodiment will be described.

[First embodiment]
The submount A10 will be described with reference to FIGS. 1 to 5. FIG. Submount A 10 comprises substrate 11 , insulating layer 12 , conductive layer 13 , metal layer 14 and conductive adhesive layer 19 . The submount A10 shown in these figures supports a semiconductor laser element 20 such as a laser diode (details will be described later). 1 to 5 (except for FIG. 3), the semiconductor laser element 20 is indicated by an imaginary line (chain double-dashed line) for convenience of understanding.

In the description of the submount A10, the thickness direction of the substrate 11 is called the "z direction" for convenience. The submount A10 has a rectangular shape when viewed in the z direction of the base material 11 . A direction perpendicular to the z-direction and along the short side of the submount A10 when viewed in the z-direction is called an "x-direction." A direction orthogonal to both the z-direction and the x-direction and along the long side of the submount A10 when viewed in the z-direction is called a "y-direction". The terms “z direction”, “x direction” and “y direction” also apply to the description of the submount A20 that will be described later.

The substrate 11 is the body of the submount A10 on which the insulating layer 12, the conductive layer 13, the metal layer 14 and the conductive adhesive layer 19 are arranged, as shown in FIGS. 1-5. The base material 11 is made of a single crystal semiconductor material. The semiconductor material includes silicon carbide (SiC) of a first conductivity type (n-type). N-type silicon carbide is obtained by adding a small amount of n-type dopant to silicon carbide, which is a single crystal and an intrinsic semiconductor (i-type), by ion implantation. An n-type dopant is, for example, nitrogen (N) or phosphorus (P). As shown in FIGS. 4 and 5, base material 11 has main surface 111 and back surface 112 . The main surface 111 faces the side where the semiconductor laser element 20 is located with respect to the substrate 11 in the z direction. The back surface 112 faces the side opposite to the main surface 111 in the z direction.

The insulating layer 12 covers at least part of the main surface 111 of the base material 11, as shown in FIGS. The insulating layer 12 covers the entire main surface 111 of the submount A10. The insulating layer 12 has electrical insulation. The thermal conductivity of the insulating layer 12 is preferably 10 to 200 W/(m·K). The thickness of the insulating layer 12 is preferably 0.05-5 μm. A more preferable thickness of the insulating layer 12 is 0.05 to 1 μm. Insulator materials such as silicon nitride (Si ₃ N ₄ ) can be cited as constituent materials of the insulating layer 12 that satisfy such thermal conductivity and thickness. The insulating layer 12 whose constituent material is silicon nitride is formed by plasma CVD (Chemical Vapor Deposition).

The constituent material of the insulating layer 12 may be a semiconductor material other than the insulating material described above. The semiconductor material is, for example, silicon carbide of the second conductivity type (p-type) or an intrinsic semiconductor. Silicon carbide of the second conductivity type is obtained by adding a small amount of p-type dopant to silicon carbide, which is a single crystal and an intrinsic semiconductor, by ion implantation. A p-type dopant is, for example, boron (B) or aluminum (Al). The method for forming the insulating layer 12 whose constituent material is silicon carbide of the second conductivity type is to form silicon carbide, which is an intrinsic semiconductor, on the main surface 111 of the base material 11 by epitaxial growth, and then apply a p-type dopant to the carbonization. Add to silicon. The amount of the p-type dopant to be added must be limited to the extent that the electrical insulation of the insulating layer 12 is ensured due to the relationship with the base material 11 . The method for forming the insulating layer 12 whose constituent material is silicon carbide, which is an intrinsic semiconductor, is to form the silicon carbide on the main surface 111 by epitaxial growth. The thickness of the insulating layer 12 when the constituent material is silicon carbide of the second conductivity type or silicon carbide which is an intrinsic semiconductor is preferably 0.2 to 10 μm. A more preferable thickness of the insulating layer 12 is 0.2 to 4 μm.

Conductive layer 13 is disposed over insulating layer 12, as shown in FIGS. 1-5 (except FIG. 3). A semiconductor laser element 20 is electrically connected to the conductive layer 13 . Conductive layer 13 is formed by stacking, for example, a titanium (Ti) layer in contact with insulating layer 12, a platinum (Pt) layer, and a gold (Au) layer in this order. The conductive layer 13 is formed by vacuum deposition.

The metal layer 14 covers the rear surface 112 of the substrate 11, as shown in FIGS. 3-5. On submount A10, metal layer 14 covers the entire back surface 112. FIG. The metal layer 14 is electrically insulated from the conductive layer 13 by the insulating layer 12 . Metal layer 14 is formed by laminating the same metal as conductive layer 13 on rear surface 112 , for example. The metal layer 14 is formed by vacuum deposition.

A conductive adhesive layer 19 is disposed over the conductive layer 13 as shown in FIGS. 1-5 (except FIG. 3). The conductive adhesive layer 19 is used to electrically bond the semiconductor laser element 20 to the conductive layer 13 . The conductive adhesive layer 19 has a barrier layer 191 and an adhesive layer 192 . The barrier layer 191 is in contact with the conductive layer 13 . The constituent material of the barrier layer 191 is titanium. The adhesion layer 192 is laminated on the barrier layer 191 . Adhesion layer 192 is a eutectic metal layer such as AuSn. The conductive adhesive layer 19 is formed by vacuum deposition. After the semiconductor laser element 20 is placed on the conductive adhesive layer 19 , the conductive adhesive layer 19 is melted by reflow and solidified, thereby electrically bonding the semiconductor laser element 20 to the conductive layer 13 . be.

The submount A10 comprises a substrate 11 made of a monocrystalline semiconductor material. The semiconductor material is silicon carbide of the first conductivity type (n-type). The thermal conductivity of silicon carbide of the first conductivity type is about 490 W/(m K), which is extremely high compared to the thermal conductivity of aluminum nitride (AlN) (about 200 W/(m K)), for example. . Thereby, the submount A10 can efficiently radiate the heat generated from the semiconductor laser element 20 . Therefore, according to the submount A10, it is possible to improve heat dissipation.

Silicon carbide of the first conductivity type is a material with relatively high marketability because it is a main material for switching elements used in power devices. Therefore, the manufacturing cost of the submount A10 can be reduced.

By including the insulating layer 12 in the submount A10, mutual electrical insulation between the conductive layer 13 and the metal layer 14 is ensured. This allows the submount A10 to be floatingly connected to the conductive member.

The coefficient of thermal expansion of silicon carbide of the first conductivity type is close to the coefficient of thermal expansion of gallium arsenide (GaAs) or gallium nitride (GaN), which are general main materials of the semiconductor laser device 20 . As a result, when the submount A10 thermally expands due to the heat emitted from the semiconductor laser element 20, the difference in thermal strain between the semiconductor laser element 20 and the submount A10 becomes as small as possible. can be suppressed.

When the insulating layer 12 is made of an insulating material such as silicon nitride, the thermal conductivity of the insulating layer 12 is preferably 10 to 200 W/(m·K). If the thermal conductivity of the insulating layer 12 is less than 10 W/(m·K), the heat dissipation of the submount A10 may deteriorate.

On the other hand, when the insulating layer 12 is made of silicon carbide of the second conductivity type (p-type) or silicon carbide which is an intrinsic semiconductor (i-type), the thermal conductivity of the insulating layer 12 is set to 10 W/(m K ) or more can be secured. The insulating layer 12 whose constituent material is silicon carbide can be easily formed by an existing semiconductor manufacturing apparatus.

Submount A10 comprises a conductive adhesive layer 19 disposed over conductive layer 13 . The conductive adhesive layer 19 has a barrier layer 191 and an adhesive layer 192 . As a result, when the adhesive layer 192 is melted by reflow, the adhesive layer 192 stays within the forming region of the barrier layer 191, so that the thickness of the adhesive layer 192 is ensured. Therefore, the bonding strength of the semiconductor laser element 20 to the conductive layer 13 can be prevented from lowering.

[Second embodiment]
The submount A20 will be described with reference to FIGS. 6 to 9. FIG. In these figures, elements that are the same as or similar to those of the submount A10 described above are denoted by the same reference numerals, and overlapping descriptions are omitted. 6 to 9 show the semiconductor laser element 20 with imaginary lines for convenience of understanding.

The submount A20 differs from the above-described submount A10 in the configuration of the insulating layer 12 and the provision of the second conductivity type semiconductor layer 15, the first pad 161 and the second pad 162. FIG.

As shown in FIGS. 6 to 9, the insulating layer 12 is formed with an opening 121 that exposes the main surface 111 of the base material 11 . In the submount A20, the opening 121 has a rectangular shape when viewed in the z direction. The opening 121 is formed by reactive ion etching (RIE). In the submount A20, it is assumed that the insulating layer 12 is made of silicon carbide, which is of the second conductivity type.

The second conductivity type semiconductor layer 15 is provided in contact with the main surface 111 of the base material 11 exposed from the opening 121 of the insulating layer 12, as shown in FIGS. The second conductivity type semiconductor layer 15 is arranged apart from the insulating layer 12 when viewed in the z direction. The main material of the second conductivity type semiconductor layer 15 is silicon carbide, which is a single crystal and an intrinsic semiconductor. Second conductivity type semiconductor layer 15 is formed by forming silicon carbide, which is an intrinsic semiconductor, on main surface 111 exposed from opening 121 by epitaxial growth, and then adding a p-type dopant to the silicon carbide. The amount of the p-type dopant added to the second conductivity type semiconductor layer 15 is different from the amount of the p-type dopant added to the insulating layer 12 whose constituent material is silicon carbide of the second conductivity type.

The first pad 161 is connected to the second conductivity type semiconductor layer 15, as shown in FIGS. 6 to 8, the second pad 162 is connected to the main surface 111 of the base material 11 exposed through the opening 121 of the insulating layer 12. As shown in FIGS. In the submount A20, the first pads 161 and the second pads 162 are arranged apart from each other in the x direction. A constituent material of the first pad 161 and the second pad 162 is, for example, gold. The first pad 161 and the second pad 162 are formed by vacuum deposition.

The submount A10 comprises a substrate 11 made of a monocrystalline semiconductor material. The semiconductor material is n-type silicon carbide. Therefore, the submount A20 can also improve heat dissipation.

In the submount A20, a pn junction is formed between the partial region of the base material 11 exposed from the opening 121 of the insulating layer 12 and the second conductivity type semiconductor layer 15. As shown in FIG. Thereby, a constant voltage diode (Zener diode) can be provided in the submount A20. In this case, the first pad 161 becomes the anode of the constant voltage diode, and the second pad 162 becomes the cathode of the constant voltage diode.

<Semiconductor laser device>
As semiconductor laser devices according to the second aspect of the present disclosure, a semiconductor laser device B10 as a first embodiment and a semiconductor laser device B20 as a second embodiment will be described.

[First embodiment]
The semiconductor laser device B10 will be described with reference to FIGS. 9 to 13. FIG. The semiconductor laser device B10 includes a submount A10, a semiconductor laser element 20, a stem 30, a bonding layer 39, a first lead 41, a second lead 42, a third lead 43, an insulating material 49, a first wire 51 and a second wire 52. and cap 60 . The semiconductor laser device B10 emits laser light 80 . For convenience of understanding, FIG. 10 shows the transparent plate 64 of the cap 60 (details will be described later). FIG. 11 shows the cap 60 through for convenience of understanding. The transparent cap 60 is shown in phantom lines in FIG. FIG. 12 is a cross-sectional view along XII-XII in FIG. 11 indicated by a dashed line.

In the description of the semiconductor laser device B10, the thickness direction of the base material 11 of the submount A10 is called the "z direction" for convenience. A direction orthogonal to the z-direction and along an inner surface 31A (details of which will be described later) of the stem 30 is called an "x-direction." A direction perpendicular to both the z-direction and the x-direction and perpendicular to the inner surface 31A of the stem 30 is called a "y-direction." Of these, one side in the "y direction" (the side facing upward in the y direction shown in FIG. 10) matches the emission direction L of the laser light 80 emitted from the semiconductor laser device B10. The terms "z direction", "x direction" and "y direction" are also applied to the description of the semiconductor laser device B20, which will be described later.

The semiconductor laser element 20 is supported by a submount A10, as shown in FIGS. 10-13. In the semiconductor laser device B10, the semiconductor laser element 20 is a laser diode. The semiconductor laser element 20 has a rectangular shape when viewed in the z direction. The semiconductor laser element 20 is supported by the submount A10 so that its long side extends along the emission direction L. As shown in FIG. A laser beam 80 is emitted in the emission direction L from the semiconductor laser element 20 . As shown in FIG. 14, the semiconductor laser device 20 includes an n-type semiconductor layer 21, an n-type cladding layer 22, an active layer 23, a p-type cladding layer 24, an insulating film 25, a p-type contact layer 26, a first electrode 27 and a It has a second electrode 28 .

The n-type semiconductor layer 21 is made of an n-type semiconductor. The n-type semiconductor layer 21 is a conductive support in the semiconductor laser element 20 . The main material of the n-type semiconductor layer 21 is gallium arsenide or gallium nitride. Gallium nitride is used as the main material of the n-type semiconductor layer 21 to improve the output of the laser light 80 emitted from the semiconductor laser element 20 . In the semiconductor laser device B10, the case where gallium nitride is used as the main material of the n-type semiconductor layer 21 will be described.

The n-type cladding layer 22 is stacked on the n-type semiconductor layer 21 on the side of the n-type semiconductor layer 21 where the submount A10 is located in the z-direction. The n-type cladding layer 22 is made of an n-type semiconductor. A main material of the n-type cladding layer 22 is, for example, InGaN.

The active layer 23 is stacked on the n-type cladding layer 22 on the side of the n-type semiconductor layer 21 where the submount A10 is located in the z-direction. The active layer 23 emits light by stimulated emission. The main material of the active layer 23 is gallium nitride.

The p-type cladding layer 24 is stacked on the active layer 23 on the side of the n-type semiconductor layer 21 where the submount A10 is located in the z-direction. The p-type cladding layer 24 is made of a p-type semiconductor. A main material of the p-type cladding layer 24 is, for example, InGaN.

The insulating film 25 covers the surface of the p-type clad layer 24 . The insulating film 25 has electrical insulation. A constituent material of the insulating film 25 is, for example, silicon dioxide (SiO ₂ ). A slit-shaped opening 251 extending in the emission direction L is formed in the insulating film 25 .

The p-type contact layer 26 fills the opening 251 of the insulating film 25 . The p-type contact layer 26 has conductivity. P-type contact layer 26 is a metal layer containing gold, for example.

The first electrode 27 covers the surface of the insulating film 25 and is in contact with the p-type contact layer 26 . The first electrode 27 is electrically connected to the p-type cladding layer 24 via the p-type contact layer 26 . Therefore, the first electrode 27 is the anode of the semiconductor laser element 20 . The first electrode 27 faces the conductive layer 13 of the submount A10. The first electrode 27 is a metal layer containing gold, for example, and is formed by vacuum deposition. The first electrode 27 is electrically joined to the conductive layer 13 by the conductive adhesive layer 19 .

The second electrode 28 is located on the opposite side of the n-type semiconductor layer 21 from the n-type cladding layer 22 in the z-direction, and covers the surface of the n-type semiconductor layer 21 . The second electrode 28 is electrically connected to the n-type cladding layer 22 . Therefore, the second electrode 28 is the cathode of the semiconductor laser element 20 . The second electrode 28 is a metal layer containing gold, for example, and is formed by vacuum deposition.

In the semiconductor laser device 20 , light is emitted from the active layer 23 when current flows from the first electrode 27 to the second electrode 28 . The light is repeatedly reflected in the z-direction by both the n-type cladding layer 22 and the p-type cladding layer 24 and resonated to become laser light 80 . A laser beam 80 is emitted in the emission direction L from the active layer 23 .

The stem 30, as shown in FIGS. 10-13, is a metallic conductive member that supports the submount A10. Thus, in the semiconductor laser device B10, the semiconductor laser element 20 is supported by the stem 30 via the submount A10. The constituent material of stem 30 is, for example, iron (Fe) or an iron alloy. In the stem 30, the surface of these metals may be plated with nickel (Ni) or the like. Stem 30 has a base 31 and a heat sink 32 . In the semiconductor laser device B10, the base 31 and the heat sink 32 are integrally formed.

As shown in FIGS. 10 to 13, the base 31 has a plate-like shape with the emission direction L as the thickness direction. In the semiconductor laser device B10, the base 31 has a substantially circular shape when viewed in the y direction. Base 31 has an inner surface 31A and an outer surface 31B. 31 A of inner surfaces face the output direction L. As shown in FIG. The outer surface 31B faces the side opposite to the emitting direction L. Also, the base 31 is provided with a first through hole 311 and a second through hole 312 . The first through hole 311 and the second through hole 312 penetrate in the emission direction L. As shown in FIG. The first through holes 311 and the second through holes 312 are separated from each other in the x direction.

As shown in FIGS. 10 to 13, the heat sink 32 protrudes in the emission direction L from the inner surface 31A of the base 31. As shown in FIGS. In the semiconductor laser device B10, the heat sink 32 has a rectangular parallelepiped shape. The heat sink 32 is separated from both the first through hole 311 and the second through hole 312 provided in the base 31 when viewed in the y direction. The heat sink 32 has a support surface 321 along both the x-direction and the exit direction L and facing the submount A10.

The bonding layer 39 is interposed between the support surface 321 of the heat sink 32 of the stem 30 and the metal layer 14 of the submount A10, as shown in FIG. Metal layer 14 is bonded to support surface 321 by bonding layer 39 . Thereby, the submount A10 is supported by the heat sink 32 via the bonding layer 39 . Also, the thickness direction (z direction) of the base material 11 of the submount A10 is orthogonal to the emission direction L. As shown in FIG. The submount A10 is supported by the heat sink 32 so that its long side extends along the emission direction L. As shown in FIG. The bonding layer 39 is, for example, an alloy (solder) containing tin (Sn). The submount A10 is floating-connected to the heat sink 32 based on the configuration described above. Therefore, the semiconductor laser element 20 is electrically insulated from the stem 30 .

The first lead 41 is, as shown in FIGS. 11 and 12, a rod-shaped conductive member inserted through a first through hole 311 provided in the base 31 of the stem 30 . A constituent material of the first lead 41 is, for example, an iron-nickel alloy. The surface of the first lead 41 may be plated with gold. The first lead 41 protrudes from the outer surface 31B of the base 31 in the direction opposite to the emission direction L. As shown in FIG. The first lead 41 also protrudes in the emission direction L from the inner surface 31A of the base 31 . In the first lead 41, the length of the section projecting in the emission direction L from the inner surface 31A is shorter than the length of the section projecting in the opposite side of the emission direction L from the outer surface 31B.

The second lead 42 is, as shown in FIGS. 11 and 12, a rod-shaped conductive member inserted through a second through hole 312 provided in the base 31 of the stem 30 . Thereby, the first lead 41 and the second lead 42 are separated from each other in the x direction. The constituent material of the second lead 42 is the same as the constituent material of the first lead 41 . The second lead 42 protrudes from the outer surface 31B of the base 31 in the direction opposite to the emission direction L. As shown in FIG. The second lead 42 also protrudes in the emission direction L from the inner surface 31A of the base 31 . In the second lead 42, the length of the section projecting in the emission direction L from the inner surface 31A is shorter than the length of the section projecting in the opposite side of the emission direction L from the outer surface 31B.

The third lead 43 is a rod-shaped conductive member joined to the outer surface 31B of the base 31 of the stem 30, as shown in FIGS. As shown in FIG. 11, the third lead 43 overlaps the heat sink 32 of the stem 30 when viewed in the y direction. Therefore, the third lead 43 is separated from both the first lead 41 and the second lead 42 . The constituent material of the third lead 43 is the same as the constituent material of the first lead 41 . The third lead 43 protrudes in the direction opposite to the emission direction L from the outer surface 31B.

The insulating material 49 is interposed between the first lead 41 and the first through hole 311 provided in the base 31 of the stem 30, as shown in FIGS. Also, the insulating material 49 is interposed between the second lead 42 and the second through hole 312 provided in the base 31 . The insulating material 49 has electrical insulation. A constituent material of the insulating material 49 is, for example, glass. The first lead 41 and the second lead 42 are electrically insulated from the stem 30 by the insulating material 49 and supported by the base 31 via the insulating material 49 .

The first wire 51 is a conductive member that connects the first lead 41 and the conductive layer 13 of the submount A10, as shown in FIG. Through the first wire 51 , the first lead 41 is electrically connected to the conductive layer 13 and further to the first electrode 27 of the semiconductor laser element 20 . Therefore, the first lead 41 is the anode of the semiconductor laser device B10. A constituent material of the first wire 51 is, for example, gold.

The second wire 52 is a conductive member that connects the second lead 42 and the second electrode 28 of the semiconductor laser element 20, as shown in FIG. The second lead 42 is electrically connected to the second electrode 28 through the second wire 52 . Therefore, the second lead 42 is the cathode of the semiconductor laser device B10. The constituent material of the second wire 52 is the same as the constituent material of the first wire 51 .

The cap 60 is fixed to the inner surface 31A of the base 31 of the stem 30, as shown in FIGS. The cap 60 includes the submount A 10 and the semiconductor laser element 20, a portion of the first lead 41 and the second lead 42 both protruding from the inner surface 31A in the emission direction L, and the first wire 51 and the second wire 52. covering the The constituent material of the cap 60 is the same as the constituent material of the stem 30 . The cap 60 has a top portion 61 , side portions 62 , a flange portion 63 and a translucent plate 64 .

As shown in FIGS. 10, 12 and 13, the apex 61 is spaced from the stem 30 in the direction of emission L and has a surface orthogonal to the direction of emission L. As shown in FIGS. In the semiconductor laser device B10, the outer peripheral edge of the surface of the top portion 61 orthogonal to the emission direction L is circular. A window portion 611 penetrating the top portion 61 in the emission direction L is provided at the center of the top portion 61 as viewed in the y direction. In the semiconductor laser device B10, the peripheral edge of the window 611 as viewed in the y direction is circular. The window portion 611 allows the laser light 80 emitted from the semiconductor laser element 20 to pass therethrough.

As shown in FIGS. 10, 12 and 13, the side portion 62 surrounds the submount A10 and the semiconductor laser element 20 when viewed in the y direction. In the semiconductor laser device B10, the side portion 62 is cylindrical. One end of the side portion 62 in the emission direction L is connected to the outer edge of the top portion 61 .

As shown in FIGS. 10, 12 and 13, the flange portion 63 is located on the opposite side of the side portion 62 from the top portion 61 in the emission direction L, and at the other end of the side portion 62 in the emission direction L. linked. The flange portion 63 protrudes outward from the peripheral edge of the side portion 62 when viewed in the y direction. In the semiconductor laser device B10, the flange portion 63 as viewed in the y-direction has an annular shape. The flange portion 63 is joined to the inner surface 31A of the base 31 of the stem 30. As shown in FIG.

10, 12 and 13, the transparent plate 64 closes the window 611 provided in the top portion 61 from the inside of the cap 60. In FIGS. The translucent plate 64 has translucency. The constituent material of the light-transmitting plate 64 is, for example, glass. A laser beam 80 emitted from the semiconductor laser element 20 is transmitted through the transparent plate 64 .

The semiconductor laser device B10 includes a submount A10, a semiconductor laser element 20 electrically connected to the conductive layer 13 of the submount A10, and a metal stem 30 supporting the submount A10. Since the heat radiation property of the submount A10 is improved by the structure described above, the heat generated from the semiconductor laser element 20 is efficiently transferred to the stem 30 via the submount A10. Therefore, according to the semiconductor laser device B10, it is possible to improve heat dissipation.

The semiconductor laser device B10 can improve heat dissipation by providing the submount A10. Therefore, according to the semiconductor laser device B10, the output of the semiconductor laser element 20 can be increased.

The semiconductor laser device B10 includes a first lead 41 and a second lead 42 supported by the stem 30. As shown in FIG. The first lead 41 is electrically connected to the conductive layer 13 of the submount A10. The second lead 42 is electrically connected to the second electrode 28 of the semiconductor laser element 20 . The submount A10 is floating-connected to the heat sink 32 of the stem 30 by the structure described above. Thus, in the semiconductor laser device B10, no current flows through the stem 30, and the electrical insulation of the semiconductor laser device B10 from the outside can be improved. This is suitable for increasing the output power of the semiconductor laser device 20 .

[Second embodiment]
The semiconductor laser device B20 will be described with reference to FIGS. 15 and 16. FIG. In these figures, elements that are the same as or similar to those of the semiconductor laser device B10 described above are denoted by the same reference numerals, and overlapping descriptions are omitted. The cross-sectional position of FIG. 15 is the same as the cross-sectional position of FIG.

The semiconductor laser device B20 differs from the previously described semiconductor laser device B10 in that a submount A20 is provided instead of the submount A10 and that a third wire 53 and a fourth wire 54 are further provided.

As shown in FIGS. 15 and 16, the support form of the submount A20 with respect to the heat sink 32 of the stem 30 is the same as the support form of the submount A10 in the semiconductor laser device B10.

The third wire 53 is a conductive member that connects the first lead 41 and the second pad 162 of the submount A10, as shown in FIGS. The first lead 41 is electrically connected to both the conductive layer 13 of the submount A20 and the second pad 162 through the first wire 51 and the third wire 53 . The constituent material of the third wire 53 is the same as the constituent material of the first wire 51 .

The fourth wire 54 is a conductive member that connects the second lead 42 and the first pad 161 of the submount A10, as shown in FIGS. The second lead 42 is electrically connected to both the second electrode 28 of the semiconductor laser element 20 and the first pad 161 through the second wire 52 and the fourth wire 54 . The constituent material of the fourth wire 54 is the same as the constituent material of the first wire 51 .

The semiconductor laser device B20 includes a submount A20, a semiconductor laser element 20 electrically connected to the conductive layer 13 of the submount A20, and a metal stem 30 supporting the submount A20. Since the heat radiation property of the submount A20 is improved by the structure described above, the heat generated from the semiconductor laser element 20 is efficiently transferred to the stem 30 via the submount A20. Therefore, according to the semiconductor laser device B20, it is possible to improve heat dissipation.

The semiconductor laser device B20 can improve heat dissipation by providing the submount A20. Therefore, according to the semiconductor laser device B20, the output of the semiconductor laser element 20 can be increased.

In the semiconductor laser device B20, the first lead 41 is electrically connected to both the conductive layer 13 of the submount A20 and the second pad 162. As shown in FIG. The second lead 42 is electrically connected to both the second electrode 28 of the semiconductor laser element 20 and the first pad 161 . The submount A20 is provided with a zener diode with the configuration described above. The first pad 161 is the anode of the constant voltage diode, and the second pad 162 is the cathode of the constant voltage diode. As a result, the semiconductor laser element 20 can be protected from reverse voltage, and the electrostatic breakdown voltage of the semiconductor laser device B20 can be improved.

The present disclosure is not limited to the embodiments described above. The specific configuration of each part of the present disclosure can be modified in various ways.

This disclosure includes the following appendices.
[Appendix 1]
a substrate having a main surface facing the thickness direction, the substrate being made of a single crystal semiconductor material;
an insulating layer having electrical insulation and covering at least a portion of the main surface;
a conductive layer disposed on the insulating layer;
The submount, wherein the semiconductor material is silicon carbide of the first conductivity type.
[Appendix 2]
10. The submount of Claim 1, wherein the insulating layer has a thermal conductivity of 10 to 200 W/(m·K).
[Appendix 3]
3. The submount of claim 2, wherein the insulating layer has a thickness of 0.05-5 μm.
[Appendix 4]
4. The submount according to appendix 2 or 3, wherein the insulating layer comprises silicon nitride.
[Appendix 5]
10. The submount of Claim 1, wherein the insulating layer has a thickness of 0.2-10 μm.
[Appendix 6]
6. The submount according to appendix 5, wherein the insulating layer is made of silicon carbide of the second conductivity type or silicon carbide which is an intrinsic semiconductor.
[Appendix 7]
7. The submount of any of Clauses 1-6, further comprising a conductive adhesive layer disposed over the conductive layer.
[Appendix 8]
8. The submount of Claim 7, wherein the conductive adhesive layer comprises a barrier layer in contact with the conductive layer and an adhesive layer laminated on the barrier layer.
[Appendix 9]
The base material has a back surface facing away from the main surface,
9. The submount of any one of Clauses 1-8, further comprising a metal layer covering the back surface.
[Appendix 10]
an opening exposing the main surface is formed in the insulating layer,
10. The submount according to appendix 9, wherein a second conductivity type semiconductor layer is provided in a partial region of the main surface exposed from the opening.
[Appendix 11]
11. The submount according to appendix 10, further comprising a first pad connected to the second conductivity type semiconductor layer and a second pad connected to the main surface exposed from the opening.
[Appendix 12]
a submount according to Appendix 9;
a semiconductor laser element that emits laser light and is electrically connected to the conductive layer of the submount;
a metal stem that supports the submount so that the thickness direction of the base material of the submount is orthogonal to the emission direction of the laser light;
a first lead and a second lead which both have sections protruding from the stem in a direction opposite to the emission direction and are supported by the stem while being spaced apart from each other;
the first lead is electrically connected to the conductive layer of the submount;
The semiconductor laser device, wherein the second lead is electrically connected to the semiconductor laser element.
[Appendix 13]
a submount according to Appendix 11;
a semiconductor laser element that emits laser light and is electrically connected to the conductive layer of the submount;
a metal stem that supports the submount so that the thickness direction of the base material of the submount is orthogonal to the emission direction of the laser light;
a first lead and a second lead which both have sections protruding from the stem in a direction opposite to the emission direction and are supported by the stem while being spaced apart from each other;
the first lead is electrically connected to both the conductive layer of the submount and the second pad;
The semiconductor laser device, wherein the second lead is electrically connected to both the semiconductor laser element and the first pad.
[Appendix 14]
The stem has a plate-like shape with a thickness direction along the radiation direction, and has a base for supporting the first lead and the second lead, and a heat sink projecting from the base in the radiation direction. ,
14. The semiconductor laser device according to appendix 12 or 13, wherein the metal layer of the submount is bonded to the heat sink.
[Appendix 15]
The semiconductor laser element has a first electrode facing the conductive layer of the submount and a second electrode spaced apart from the first electrode in the thickness direction of the base material of the submount,
the first electrode is electrically bonded to the conductive layer;
15. The semiconductor laser device according to appendix 14, wherein the second electrode is electrically connected to the second lead.
[Appendix 16]
The base has a first through hole through which the first lead is inserted, and a second through hole through which the second lead is inserted. provided,
further comprising an insulating material interposed between the first through-hole and the first lead, and interposed between the second through-hole and the second lead;
16. The semiconductor laser device according to appendix 15, wherein the first lead and the second lead are supported by the base via the insulating material.
[Appendix 17]
further comprising a cap covering the submount and the semiconductor laser element and fixed to the base;
16. The semiconductor laser device according to appendix 15, wherein the cap is provided with a window through which the laser light emitted from the semiconductor laser element passes.

Claims (15)

a substrate having a main surface facing the thickness direction and made of a single-crystal semiconductor material;
an insulating layer having electrical insulation and covering at least a portion of the main surface;
a conductive layer disposed on the insulating layer;
the semiconductor material is silicon carbide of a first conductivity type;
an opening exposing the main surface is formed in the insulating layer,
the insulating layer has an inner peripheral surface that faces in a direction orthogonal to the thickness direction and defines the opening;
further comprising a second conductivity type semiconductor layer protruding from the main surface exposed from the opening and separated from the insulating layer;
The submount, wherein the second conductivity type semiconductor layer overlaps the inner peripheral surface when viewed in a direction orthogonal to the thickness direction . The submount of claim 1, wherein the insulating layer has a thermal conductivity of 10-200 W/(m·K). 3. The submount of claim 2, wherein the insulating layer has a thickness of 0.05-5 μm. 4. The submount according to claim 2, wherein a constituent material of said insulating layer includes silicon nitride. 2. The submount of claim 1, wherein the insulating layer has a thickness of 0.2-10 μm. 6. The submount according to claim 5, wherein a constituent material of the insulating layer is silicon carbide of the second conductivity type or silicon carbide which is an intrinsic semiconductor. 7. The submount of any of claims 1-6, further comprising a conductive adhesive layer disposed over the conductive layer. 8. The submount of claim 7, wherein the conductive adhesive layer comprises a barrier layer in contact with the conductive layer and an adhesive layer laminated over the barrier layer. The base material has a back surface facing away from the main surface,
9. The submount of any one of claims 1-8, further comprising a metal layer covering the back surface. 10. The submount according to claim 9, further comprising a first pad connected to said second conductivity type semiconductor layer and a second pad connected to said main surface exposed from said opening. a submount according to claim 10;
a semiconductor laser element that emits laser light and is electrically connected to the conductive layer of the submount;
a metal stem that supports the submount so that the thickness direction is perpendicular to the direction of emission of the laser light;
a first lead and a second lead which both have sections protruding from the stem in a direction opposite to the emission direction and which are supported by the stem while being spaced apart from each other;
the first lead is electrically connected to both the conductive layer of the submount and the second pad;
The semiconductor laser device, wherein the second lead is electrically connected to both the semiconductor laser element and the first pad. The stem has a plate-like shape with a thickness direction along the radiation direction, and has a base for supporting the first lead and the second lead, and a heat sink projecting from the base in the radiation direction. ,
12. The semiconductor laser device according to claim 11, wherein said metal layer of said submount is bonded to said heat sink . The semiconductor laser element has a first electrode facing the conductive layer of the submount and a second electrode spaced apart from the first electrode in the thickness direction,
the first electrode is electrically connected to the conductive layer;
13. The semiconductor laser device according to claim 12, wherein said second electrode is electrically connected to said second lead . The base has a first through hole through which the first lead is inserted, and a second through hole through which the second lead is inserted. is provided,
further comprising an insulating material interposed between the first through-hole and the first lead, and interposed between the second through-hole and the second lead;
14. The semiconductor laser device according to claim 13 , wherein said first lead and said second lead are supported by said base via said insulating material . further comprising a cap covering the submount and the semiconductor laser element and fixed to the base;
15. The semiconductor laser device according to claim 14 , wherein said cap is provided with a window through which said laser light emitted from said semiconductor laser element passes.

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