JP2019207966A - Semiconductor light-emitting element - Google Patents

Abstract

To provide a semiconductor light-emitting element capable of appropriately securing a heat radiation path of heat emitted from an emitter and improving inrush current-light output characteristics (heat characteristics).SOLUTION: A semiconductor light-emitting element comprises: a semiconductor substrate 11 having first and second surfaces; a semiconductor layer 12 formed on the first surface of the semiconductor substrate 11; a plurality of light emission parts 15a and 15b which are arranged in a first direction separated individually in the semiconductor layer 12, and electrically connected to each other; a first electrode 13 formed on the semiconductor layer 12; and a second electrode 14 formed on the second surface of the semiconductor substrate 11. The first electrode 13 includes: a first part 13a positioned at an outer side from an outer terminal part of each light emission part arranged at the outermost side in the first direction; and a second part 13b between an inner terminal part of each light emission part arranged at the outermost side and the outer end part of the adjacent light emission parts. In the first direction, a width of the first part 13a has a length of a half or more of a width of the second part 13b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a semiconductor light emitting device including a plurality of light emitting units.

  Conventionally, in a semiconductor chip having a plurality of light emitting portions (emitters), focusing on thermal crosstalk (thermal interference) between emitters, improvement of injection current-light output characteristics (IL characteristics) and improvement of heat dissipation Is planned. For example, Patent Documents 1 and 2 disclose a technique for reducing thermal interference between a plurality of adjacent active regions by providing a heat dissipation portion between a plurality of emitters.

JP 2013-179209 A JP 2013-179210 A

Conventionally, in order to improve the IL characteristics of a semiconductor chip and to improve heat dissipation, measures have been taken such as providing a heat dissipation member between the emitters and increasing the distance between the emitters as described above.
However, it has been found as a new finding that the heat dissipation path outside the emitter is important for improving the IL characteristics and heat dissipation of the semiconductor chip. If the heat radiation path from the outside of the emitter is restricted, there is a problem that the heat radiation characteristic of the semiconductor chip is deteriorated and the light output is lowered.
Therefore, an object of the present invention is to provide a semiconductor light emitting device that can appropriately secure a heat radiation path for heat generated from the emitter and improve the IL characteristics (heat radiation characteristics).

  In order to solve the above problems, an embodiment of a semiconductor light emitting device according to the present invention includes a semiconductor substrate having a first surface and a second surface, a semiconductor layer formed on the first surface of the semiconductor substrate, Within the semiconductor layer, a plurality of light emitting portions that are spaced apart from each other in the first direction and are electrically connected to each other, a first electrode formed on the semiconductor layer, and the second of the semiconductor substrate A second electrode formed on a surface, wherein the first electrode is a first portion outside the outer end portion of the light emitting unit disposed on the outermost side in the first direction, and the outermost side. A second portion between an inner end portion of the light emitting portion and an outer end portion of the adjacent light emitting portion, and in the first direction, the width of the first portion is The second portion has a length that is at least half the width of the second portion.

  In this way, by setting the width of the first portion of the first electrode to a length that is half or more of the width of the second portion, the light emitting portion adjacent to the outer side of the light emitting portion (emitter) disposed on the outermost side ( It is possible to secure a heat radiation path equivalent to or greater than the heat radiation path inside the emitter corresponding to half of the electrode width between the emitters). Therefore, the heat from the emitter can be radiated efficiently. In a semiconductor light emitting device in which a plurality of emitters are electrically connected and driven independently, thermal crosstalk between the plurality of emitters can be a serious problem. By setting it as the above structures, heat dissipation can be improved appropriately and the IL characteristic can be improved.

In the semiconductor light emitting device, the plurality of light emitting units include a first light emitting unit and a second light emitting unit arranged on the outermost side in the first direction. The outer end portion of the first light emitting unit and the outer end portion of the second light emitting unit may be arranged on the outer side.
In this way, half of the width of the second portion on the outer side of each outer end portion of the two light emitting portions (first light emitting portion, second light emitting portion) arranged closest to the outer peripheral portion of the semiconductor layer. The 1st part which has the above length may be arranged. In this case, since heat radiation paths can be secured at both ends of the semiconductor layer, heat from the emitter can be efficiently radiated.
In the semiconductor light emitting device, the first portion may have a width that is equal to or less than a width of the second portion in the first direction.
Thus, by providing an upper limit on the width of the first portion of the first electrode, it is possible to suppress the chip width (area) from being excessively widened, and to reduce the number of chips acquired per one wafer (chip acquisition rate). Can be suppressed. Moreover, it can suppress that the stress concerning a chip | tip becomes large too much, and can suppress that the curvature of a chip | tip and the position shift of several light emission part arise.

Further, in the semiconductor light emitting device, in the first direction, a half width of the second portion may be longer than a width of the light emitting portion.
In this case, a heat dissipation path equal to or greater than the emitter width can be secured inside the emitter. The wider the emitter width, the higher the output and the greater the heat generated from the emitter. Therefore, by appropriately securing the heat radiation path according to the emitter width as described above, the IL characteristic can be appropriately improved.

Further, in the semiconductor light emitting element, in the first direction, the total width of the plurality of light emitting portions may have a length of 10% or more of the width of the first surface of the semiconductor layer. .
In this case, in a multimode semiconductor light emitting device having a wide emitter width (broad area), it is possible to appropriately improve heat dissipation and improve IL characteristics.

  According to the semiconductor light emitting device of the present invention, by securing the electrode width outside the emitter, it is possible to appropriately secure a heat radiation path for heat generated from the emitter and improve the characteristics (heat radiation characteristics).

It is sectional drawing which shows the structural example (W2 = (W1) / 2) of the semiconductor chip in this embodiment. It is sectional drawing which shows the structural example (W2 = W1) of the semiconductor chip in this embodiment. It is a figure explaining the heat dissipation path | route of the semiconductor light-emitting device in this embodiment. It is sectional drawing which shows the structural example (W2 = (W1) / 6) of the conventional semiconductor chip. It is a figure explaining the heat dissipation path | route of the conventional semiconductor light-emitting device. It is a figure which shows IL characteristic (injection electric current-light output characteristic). It is sectional drawing which shows the structural example of the semiconductor chip of 3 emitters. It is sectional drawing which shows the structural example of the semiconductor chip which has a ridge structure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration example of a semiconductor chip (LD chip) 10 constituting the semiconductor light emitting element in the present embodiment.
The LD chip 10 includes a semiconductor substrate 11 having a first surface and a second surface, and a multilayer semiconductor layer 12 formed by epitaxial growth on the first surface of the semiconductor substrate 11. In the present embodiment, the first surface of the LD chip 10 is the upper surface in FIG. The second surface of the LD chip 10 is a surface opposite to the first surface, that is, the lower surface in FIG.
The semiconductor substrate 11 can be a GaAs substrate, for example. For example, the semiconductor substrate 11 may be an n-GaAs inclined substrate whose main surface is a surface inclined by a predetermined inclination angle θ (for example, 10 °) in the <011> direction from the (100) plane. The LD chip 10 oscillates a 600 nm band (for example, red) laser beam when it is assembled in a semiconductor laser device and supplied with a predetermined injection current.

The semiconductor layer 12 includes an active layer (not shown) (for example, GaInP). Specifically, the semiconductor layer has a configuration in which at least a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer are stacked in this order on the semiconductor substrate 11. The first conductivity type semiconductor layer is an n-type cladding layer (for example, n-AlGaInP), and the second conductivity type semiconductor layer is a p-type cladding layer (for example, p-AlGaInP).
Further, the LD chip 10 includes a p-side electrode (first electrode) 13 formed on the semiconductor layer 12 via an insulating film 16 described later, and a second surface of the semiconductor substrate 11 (the semiconductor layer 12 in the semiconductor substrate 11). And an n-side electrode (second electrode) 14 formed on the opposite surface. The first electrode 13 and the second electrode 14 are made of, for example, gold (Au). The first electrode 13 and the second electrode 14 may be multilayer electrode layers. For example, the first electrode 13 and the second electrode 14 may be multilayer electrode layers made of Ti / Pt / Au.

Furthermore, the LD chip 10 includes two light emitting portions (emitters) 15a and 15b disposed in the semiconductor layer 12 so as to be separated from each other in the first direction (left and right direction in FIG. 1). These two light emitting portions 15a and 15b correspond to specific regions of the active layer. The specific region corresponds to the opening of the insulating film 16 and is a region where current is concentrated and injected to emit laser light.
The first electrode 13 is connected across the two light emitting portions 15a and 15b, and the light emitting portions 15a and 15b are electrically connected to each other. That is, the first electrode 13 is not divided between the emitters, and the plurality of emitters are driven independently (the same drive).

  The first electrode 13 includes a first portion 13a located outside the outer ends of the light emitting portions 15a and 15b in the first direction, and a second portion 13b located between the two adjacent light emitting portions 15a and 15b. Have. In the first direction, the width of the first portion 13a is at least half the width of the second portion 13b. Here, the width of the electrode may be the width of the first electrode 13 on the side facing the semiconductor layer 12 (light emitting part side), or the opposite side of the first electrode 13 to the semiconductor layer 12 (sub-layer described later). It may be the width of the side to be joined to the mount. The width of the electrode may be aligned with the width of the LD chip, or may be inside the width of the LD chip. When it is inside the width of the LD chip, when the LD chip is bonded to the submount, it is possible to prevent a problem that a bonding material such as solder crawls up to the side surface of the chip and is electrically short-circuited.

That is, the width in the first direction of the second portion 13b located between the light emitting portions 15a and 15b is W1, the width in the first direction of the first portion 13a located outside the light emitting portion 15a is W2, and the width of the light emitting portion 15b. When the width of the first portion 13a located outside in the first direction is W2 ′, the following relational expression is established.
(W1) / 2 ≦ W2,
(W1) / 2 ≦ W2 ′ (1)
FIG. 1 shows the LD chip 10 when the widths W2 and W2 ′ of the first portion 13a are set to (W1) / 2, which is the lower limit value.

In the first direction, the width of the first portion 13a can be set to a length equal to or smaller than the width of the second portion 13b. That is, the following relational expression holds.
(W1) / 2 ≦ W2 ≦ W1,
(W1) / 2 ≦ W2 ′ ≦ W1 (2)
FIG. 2 is a cross-sectional view showing the LD chip 10A when the widths W2 and W2 ′ of the first portion 13a are set to the upper limit value W1. In FIG. 2, the widths We and We ′ of the light emitting portions 15a and 15b and the width W1 of the second portion 13b are the same as those of the LD chip 10 shown in FIG.

Furthermore, in the first direction, the half width of the second portion 13b can be longer than the width of the light emitting portions 15a and 15b. That is, when the widths of the light emitting portions 15a and 15b are We and We ′, the following relational expression is established.
We ≦ (W1) / 2
We ′ ≦ (W1) / 2 (3)

In the first direction, the total width of the plurality of light emitting portions 15 a and 15 b can be 10% or more of the width of the first surface of the semiconductor layer 12. That is, when the total width (We + We ′) of the plurality of light emitting portions 15a and 15b is We−sum and the width of the first surface of the semiconductor layer 12 is Wc, the following relational expression is established.
We-sum ≧ Wc × 0.1 (4)
In the first direction, the width of one light emitting portion can be 5 μm or more.
For example, the widths We and We ′ of the light emitting portions 15a and 15b can be 75 μm, and the width W1 of the second portion 13b can be 150 μm. In this case, in FIG. 1, the widths W2 and W2 ′ of the first portion 13a are 75 μm, and in FIG. 2, the widths W2 and W2 ′ of the first portion 13a are 150 μm. Moreover, the thickness of the 1st electrode 13 can be 3 micrometers, for example. The thicker the electrode, the wider the heat dissipation path and the effect of heat dissipation can be obtained. However, the stress of the electrode increases and the chip may be warped. In this case, the plurality of light emitting units may be distorted without being aligned in a line in the first direction, resulting in a defect as a product. Therefore, in terms of securing a heat dissipation path, it is preferable that the thickness of the electrode is as large as possible, and a thickness of 0.5 μm or more is necessary, but from the viewpoint of suppressing variation in the light emitting portion, the thickness of the electrode is 10 μm or less. It is preferable that
Further, from the viewpoint of securing a heat dissipation path, it is preferable that the plurality of light emitting units are connected by electrodes, and more preferably the electrodes are flat. When a plurality of light emitting units are connected by electrodes, parallel driving is performed.

As shown in FIG. 3, the LD chip 10 is bonded to a submount 20 constituting a semiconductor laser device.
The main body of the submount 20 can be made of, for example, aluminum nitride (AlN). The main body of the submount 20 can be appropriately selected in consideration of heat dissipation, insulation, a difference in linear expansion coefficient from the LD chip 10 and cost. For example, silicon carbide (SiC), diamond, etc. for insulating materials with good heat dissipation, Cu, CuW, CuMo, etc. for conductive materials, and Si, aluminum oxide (Al ₂ O ₃ ), etc. for relatively inexpensive materials There is. Further, the main body portion of the submount 20 may have a multilayer structure in which an insulating material such as SiC and a conductive material such as Cu are combined.

  An electrode wiring (not shown) is formed on the surface of the submount 20 by using gold (Au), and the LD chip 10 is formed on the electrode wiring by a junction down method via, for example, gold tin (AuSn) solder. Be joined. That is, the surface of the first electrode 13, which is the surface of the LD chip 10 on the light emitting portions 15 a and 15 b side (semiconductor layer 12 side), serves as a bonding surface and is bonded to the submount 20. Thereby, the first electrode 13 and the electrode wiring of the submount 20 are electrically connected. The bonding material on the surface of the submount 20 is a solder material such as tin-silver-copper (SnAgCu), tin-silver (SnAg), tin-gold (SnAu), as well as low indium (In), silver (Ag) paste, A melting point metal material may be used.

When an injection current is supplied to the LD chip 10 and the LD chip 10 is driven, laser light is emitted from the light emitting units 15a and 15b. At this time, the light emitting units 15 a and 15 b generate heat, and the generated heat is transmitted to the submount 20 via the first electrode 13 and radiated. Specifically, as indicated by arrows in FIG. 3, heat from the light emitting units 15 a and 15 b passes through the first electrode 13 and the normal direction of the first surface of the semiconductor substrate 11 (A1 direction in FIG. 3), It is transmitted in the A2 direction toward the inside of the chip and the A3 direction toward the outside of the chip, and is transmitted to the submount 20. Thus, the 1st electrode 13 becomes a heat dissipation path (heat conduction path).
3 shows the case where the LD chip 10 shown in FIG. 1 is bonded to the submount 20, the same applies to the case where the LD chip 10A shown in FIG.

Conventionally, measures such as increasing the distance between emitters have been taken in consideration of thermal crosstalk between a plurality of emitters. However, in order to improve the chip acquisition rate, which is the number of chips acquired per wafer, it has been common to design the width of the electrode outside the emitter as narrow as possible.
On the other hand, in the present embodiment, due to a new finding that it is important to secure a heat radiation path to the outside of the emitter, in the LD chip 10, 10A, the first portion that is the portion outside the emitter of the first electrode 13 is used. The electrode width of 13a was ensured. Specifically, considering that the heat from each emitter escapes evenly on the left and right, a heat dissipation path is secured on the outer side of the emitter, equivalent to or more than the heat dissipation path on the inner side of the emitter corresponding to half the electrode width between adjacent emitters. (Formula (1) above). As a result, the LD chips 10 and 10A of the present embodiment can improve the heat dissipation and the IL characteristics as compared with the LD chip having the conventional configuration in which the heat dissipation path outside the emitter is limited.

FIG. 4 is a cross-sectional view showing a configuration example of a conventional semiconductor chip (LD chip) 110 as a comparative example.
The LD chip 110 shown in FIG. 4 has the same emitter width (We, We ′) and emitter interval (W1) as the LD chip 10 shown in FIG. 1, and the electrode width (W2, W2 ′) outside the emitter. Has a short configuration. FIG. 4 shows an example in which the width of the first portion 13a of the LD chip 110 is 1/6 of the width of the second portion 13b. That is, W2, W2 ′ = (W1) / 6.

  As shown in FIG. 5, when the LD chip 110 shown in FIG. 4 is joined and driven to the submount 20 that constitutes the semiconductor laser device, the heat from the light emitting units 15 a and 15 b passes through the first electrode 13. Is transmitted to the submount 20 to dissipate heat. However, in the LD chip 110, since the heat radiation path outside the emitter is limited, heat escape to the outside of the chip becomes insufficient. For this reason, the LD chip 110 has a problem that the heat radiation characteristic is deteriorated and the light output is lowered.

FIG. 6 is a diagram showing IL characteristics (measurement temperature of 45 ° C.) showing the relationship between the injection current and the optical output in the LD chips 10 and 10A in the present embodiment and the LD chip 110 as a comparative example. . In FIG. 6, the horizontal axis represents the injection current If, and the vertical axis represents the optical output Po. Further, in FIG. 6, a curve A is an IL characteristic line of the LD chip 10A shown in FIG. 2, a curve B is an IL characteristic line of the LD chip 10 shown in FIG. 1, and a curve C is shown in FIG. It is an IL characteristic line of the LD chip 110.
As apparent from FIG. 6, the LD chip 10, 10 </ b> A has a significantly improved saturation point of light output as compared with the LD chip 110. Further, as is clear from a comparison between the LD chip 10 and the LD chip 10A, it is understood that the saturation point of the light output is greatly improved as the electrode width (W2, W2 ′) outside the emitter is increased. In this way, it was confirmed that by increasing the electrode width (W2, W2 ′) outside the emitter and securing the heat radiation path outside the emitter, the heat radiation characteristics of the LD chip can be improved and improved, and the light output can be increased. .

Incidentally, as described above, the heat radiation characteristics of the LD chip can be improved as the heat radiation path (electrode width) outside the emitter is increased. However, if the heat radiation path (electrode width) outside the emitter is made too wide, there is a problem that the chip width (area) increases and the number of chips (chip acquisition rate) that can be acquired from one wafer decreases. A decline in the chip acquisition rate leads to a rise in chip costs.
Further, if the electrode width outside the emitter is too wide, the stress of the electrode increases and the chip may be warped. In this case, the plurality of light emitting units may be distorted without being aligned in a line in the first direction, resulting in a defect as a product.
Therefore, in terms of securing a heat radiation path, the electrode width (W2, W2 ′) outside the emitter is preferably as wide as possible, and is at least half the width (W1) between the emitters, that is, ((W1) / 2. ) The above length is necessary, but from the viewpoint of improving the chip acquisition rate (reducing the chip cost) and suppressing variation in the light emitting part, the electrode width outside the emitter should be less than the width (W1) between the emitters. Is preferable (the above formula (2)).

As described above, the LD chips 10 and 10A in this embodiment include the semiconductor substrate 11 having the first surface and the second surface, the semiconductor layer 12 formed on the first surface of the semiconductor substrate 11, and the semiconductor layer. 12, a plurality of light emitting portions 15a and 15b that are spaced apart from each other in the first direction and are electrically connected to each other, the first electrode 13 formed on the semiconductor layer 12, and the first of the semiconductor substrate 11, respectively. And a second electrode 14 formed on two surfaces. The first electrode 13 includes a first portion 13a located outside the outer end portions of the light emitting portions 15a and 15b and a second portion 13b located between the light emitting portions 15a and 15b.
In the first direction, the widths W2 and W2 ′ of the first portion 13a are more than half the width W1 of the second portion 13b. In the first direction, the widths W2 and W2 ′ of the first portion 13a can be set to be equal to or shorter than the width W1 of the second portion 13b.

  Thus, by securing the electrode width outside the light emitting portions (emitters) 15a and 15b, heat can be appropriately released from the electrodes arranged in the outer peripheral portion of the chip, and the heat dissipation characteristics of the LD chip can be improved. Can be improved. As a result, the IL characteristic of the LD chip can be improved. Furthermore, by providing an upper limit (W1) to the electrode width outside the light emitting portions (emitters) 15a and 15b, it is possible to suppress the chip width (area) from becoming too large and to suppress a decrease in the chip acquisition rate. . In addition, the stress applied to the chip can be suppressed, and variations in the light emitting portion can be suppressed.

In the present embodiment, the first electrode 13 is connected across a plurality of emitters, and the plurality of emitters are driven independently (the same drive). On the other hand, in a multi-beam product in which a plurality of emitters are independently driven, the electrode is divided, so that thermal crosstalk does not occur on the electrode side (heat radiation path side). For products that are driven in the same way, it is important to suppress the above-mentioned thermal crosstalk and improve the heat dissipation from the emitter. As a product that does not require independent driving of a plurality of emitters, for example, there is an LD for a projector. On the other hand, as a product premised on independent driving of a plurality of emitters, for example, there is an LD used as a light source for a printer.
Since the LD chips 10 and 10A of the present embodiment have a configuration in which the heat radiation path outside the emitter is secured as described above, the heat from the emitter can be quickly dissipated, and a plurality of emitters that are driven in the same manner. The thermal crosstalk in can be appropriately suppressed.

  Further, in the present embodiment, in the LD chips 10 and 10A, the heat radiation path inside the emitter corresponding to half of the electrode width between the emitters can be equal to or longer than the emitter width (formula (3) above). . That is, the electrode width (W1) between the emitters can be made twice or more the emitter width (We, We ′). Thereby, the distance between emitters can be ensured and the heat radiation path inside an emitter can be ensured appropriately. Therefore, thermal crosstalk between a plurality of emitters that are driven in the same manner can be more appropriately suppressed, and the IL characteristic can be improved.

In this embodiment, the LD chips 10 and 10A have a wide emitter width in which the total width of the light emitting portions 15a and 15b is 10% or more of the width of the first surface of the semiconductor layer 12. It can be a multimode product (area (4) above).
For example, in an LD for projector use, independent driving of a plurality of emitters is not required, and higher output is required. And the higher the output, the wider the emitter width is set to reduce the light density at the end face. Also, the higher the output, the higher the input power, and the greater the heat generated from the emitter. Therefore, in such a multi-mode high-power product, it is important to appropriately secure a heat dissipation path.

On the other hand, a multi-beam LD used for a light source for a printer, for example, is a product that requires a small spot diameter, and thus is a single-mode product with a narrow emitter width of several μm. In a single mode product, the total emitter width is about 5% at most with respect to the width of the semiconductor layer. In the case of such a single mode product, since the output is low, the heat generation is small, and the size of the heat radiation path at the electrode does not have a great influence on the characteristics.
In the present embodiment, in a multi-mode product having a wide emitter width (broad area), it is possible to appropriately secure a heat dissipation path and obtain a more desirable IL characteristic improvement effect.

(Modification)
In the embodiment described above, the LD chip is described as including two light emitting units, but the number of light emitting units may be three or more. However, the three or more light emitting units are configured to be electrically connected to each other.
FIG. 7 is a cross-sectional view showing a configuration example of a three-emitter LD chip 10B.
The LD chip 10B includes three light emitting units 15a to 15c. In this case, the outer portions of the light emitting portions 15a and 15c arranged on the outermost side in the first direction are the first portions 13a described above. Further, the light emission adjacent to the inner end of the light emitting part 15a arranged on the outermost side and the outer end of the adjacent light emitting part 15b and to the inner end of the light emitting part 15c arranged on the outermost side. The space between the outer end portion of the portion 15b is the second portion 13b described above. Also in this case, the same effect as in the case of the two emitters shown in FIGS. 1 and 2 can be obtained.

Moreover, although the case where all the width | variety of several emitter was the same was demonstrated in the said embodiment, the width | variety of each emitter may differ. That is, in FIG. 1 and FIG. 2, the width We of the light emitting portion 15a may be different from the width We ′ of the light emitting portion 15b. Furthermore, in FIG. 7, the width We of the light emitting portion 15a, the width We ′ of the light emitting portion 15b, and the width We ″ of the light emitting portion 15c may be different from each other.
Further, since the heat generated from the emitter increases as the width of the emitter increases, the electrode width (W2, W2 ′) outside the emitter may be set according to the width of the emitter. That is, the electrode width outside the emitter may be set wider as the emitter width is wider.

Further, in the above-described embodiment, the LD chip may include a current confinement portion having a ridge structure in the semiconductor layer 12 in order to concentrate and inject current into the light emitting portion.
FIG. 8 is a cross-sectional view illustrating a configuration example of an LD chip 10C including a current confinement portion having a ridge structure. The LD chip 10C shown in FIG. 8 has the same configuration as that of the LD chip 10 shown in FIG. Even in the case of having the ridge structure, since the electrode serves as a heat dissipation path, the same effect as in the case of not having the ridge structure shown in FIG. 1 can be obtained.

In the above embodiment, the semiconductor substrate 11 is a GaAs substrate. However, the present invention is not limited to this. For example, the semiconductor substrate 11 may be an InP substrate, a GaN substrate, or a Si substrate. The material of the semiconductor substrate 11 can be appropriately selected according to the emission wavelength.
In the present embodiment, the case where the first surface and the second surface of the LD chip 10 are arranged in parallel has been described. However, the first surface and the second surface may not be arranged in parallel. Good. For example, the second surface may be a surface perpendicular to the first surface.

  DESCRIPTION OF SYMBOLS 10 ... LD chip | tip, 11 ... Semiconductor substrate, 12 ... Semiconductor layer, 13 ... P side electrode (1st electrode), 13a ... 1st part, 13b ... 2nd part, 14 ... N side electrode (2nd electrode), 15a , 15b ... light emitting part, 16 ... insulating film, 17 ... ridge structure, 20 ... submount

Claims (5)

A semiconductor substrate having a first surface and a second surface;
A semiconductor layer formed on the first surface of the semiconductor substrate;
A plurality of light emitting units disposed in the semiconductor layer and spaced apart from each other in the first direction, and electrically connected to each other;
A first electrode formed on the semiconductor layer;
A second electrode formed on the second surface of the semiconductor substrate,
The first electrode is
A first portion on the outer side of the outer end portion of the light emitting unit disposed on the outermost side in the first direction;
A second portion between an inner end portion of the light emitting portion disposed on the outermost side and an outer end portion of the adjacent light emitting portion;
In the first direction, the width of the first portion is not less than half the width of the second portion. The plurality of light emitting units include a first light emitting unit and a second light emitting unit, which are disposed on the outermost side in the first direction,
2. The semiconductor light emitting device according to claim 1, wherein the first portion is disposed outside an outer end portion of the first light emitting portion and an outer end portion of the second light emitting portion.   3. The semiconductor light emitting element according to claim 1, wherein, in the first direction, a width of the first portion is equal to or less than a width of the second portion.   4. The semiconductor light emitting element according to claim 1, wherein, in the first direction, a half width of the second portion has a length equal to or greater than a width of the light emitting portion. 5. 5. The device according to claim 1, wherein, in the first direction, a total width of the plurality of light emitting units has a length of 10% or more of a width of the first surface of the semiconductor layer. The semiconductor light emitting device according to item.

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