JP2003008143A - Multi-beam semiconductor laser device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-beam semiconductor laser device which outputs beams uniform in optical output and is suitably constituted so as to output large high optical power. SOLUTION: This multi-beam semiconductor laser device is a GaN semiconductor laser device having an SCH structure, where laser stripes 44 are provided on a common sapphire board 42, and laser beams are projected from the stripe projection end faces 44a of the laser stripes provided to a cleavage plane vertical to the laser stripes 44. The laser stripes 44 are each of an air ridge type which is current-constricted by an SiO2 film, a P-side electrode 46 is provided on each ridge, and the laser stripes 44 are formed on a common mesa 45 provided on the sapphire board 42. An N-side electrode 48 is exposed behind the common mesa 45 as a common counter electrode to the P-side electrodes 46, and provided on a contact layer 50 which extends from the rear end face of the laser stripes 44 in the direction of the laser stripes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam semiconductor laser device, and more particularly to a multi-beam semiconductor laser device having a structure suitable for high output and having a uniform light output of the beams emitted from each laser stripe. The present invention relates to a semiconductor laser device.

[0002]

2. Description of the Related Art In recent years, in devices such as optical disk devices, laser beam printers, and copying machines that use a semiconductor laser as a light source, there has been a demand for faster operation and larger information processing capacity. Therefore, it has been proposed to use a so-called multi-beam semiconductor laser that emits a plurality of laser beams (hereinafter, referred to as multi-beams) as a light source according to the increase in speed and capacity of the device. For example, in an optical disk device, a multi-beam semiconductor laser is used, and the reading speed can be increased by simultaneously reading a plurality of tracks with a plurality of laser beams. Further, the optical output required as a light source of an optical disk device is about several tens mW at most, but by increasing the optical output of a semiconductor laser device to W class, it can be applied to the laser processing field and the medical field. . Therefore, research is being conducted to increase the optical output of the entire laser beam by using a multi-beam semiconductor laser.

The structure of a conventional multi-beam semiconductor laser device will be described with reference to FIGS. 8 and 9. Figure 8
9 and 9 are developed views for explaining the configuration of a conventional multi-beam semiconductor laser device, respectively. As shown in FIG. 8, a multi-beam semiconductor laser device 10 of the first conventional example is a semiconductor laser device that emits two laser beams, and two laser oscillation units 14 that share a substrate 12 are used.
And each of the laser oscillators 14 is provided with an electrode 16. The counter electrode 17 facing the electrode 16 is provided on the back surface of the substrate 12 as a common electrode.

Further, the multi-beam semiconductor laser device 10
Are two contact electrodes 18A and 18B respectively connected to the two electrodes 16A and B, and a contact electrode 18
A wiring board 20A and B for connecting A and B to an external terminal is provided, and the electrodes 16A and B and the contact electrodes 18A and B are electrically and mechanically connected to each other to form an integrated structure. It is configured as a multi-beam semiconductor laser device.

The multi-beam semiconductor laser device 24 of the second conventional example is, as shown in FIG. 9, a semiconductor laser device which emits four laser beams, and four laser oscillating units having a substrate 26 in common. 28A to D, and electrodes 30A to 30D are provided on the laser oscillators 28A to 28D, respectively. The counter electrode 31 facing the electrode 30 is provided on the back surface of the substrate 26 as a common electrode. Further, the multi-beam semiconductor laser device 24 includes four contact electrodes 32A to 32D respectively connected to the four electrodes 30A to 30D.
The wiring board 34A to D for connecting the contact electrodes 32A to 32D to the external terminals is provided, and the electrode 30A is provided.
-D and contact electrodes 34A-D are electrically and mechanically connected to form an integrated multi-beam semiconductor laser device.

[0006]

However, the above-mentioned conventional multi-beam semiconductor laser device has the following problems. That is, Ga formed on the sapphire substrate
There is a problem that it is difficult to apply the configuration of the conventional multi-beam semiconductor laser device to a semiconductor laser device in which the p-side electrode and the n-side electrode are on the same side with respect to the substrate like the N-based semiconductor laser device. Further, in a GaN-based semiconductor laser device in which the p-side electrode and the n-side electrode are on the same side with respect to the substrate, it is difficult to manufacture a multi-beam semiconductor laser device in which the light output of each laser beam is uniform. Therefore, it was actually difficult to increase the optical output by applying the configuration of the conventional multi-beam semiconductor laser device to the GaN-based multi-beam semiconductor laser device to increase the number of laser beams. .

Therefore, an object of the present invention is to provide a multi-beam semiconductor laser device having a structure in which the laser light emitted from each laser stripe has a uniform light output and is suitable for high light output.

[0008]

In order to achieve the above object, a multi-beam semiconductor laser device according to the present invention has a plurality of laser stripes on a common substrate and is provided on a cleavage plane orthogonal to the laser stripes. Is a multi-beam semiconductor laser device that emits laser light from a stripe emission end face of each laser stripe, and each laser stripe has one of a p-side electrode and an n-side electrode on each ridge stripe. Then, the other of the p-side electrode and the n-side electrode is formed on the common mesa formed on the substrate, and the other of the p-side electrode and the n-side electrode is exposed behind the common mesa, and the laser stripe Is provided on a contact layer extending in the laser stripe direction from the rear end face side of the.

In the present invention, each laser stripe has the same positional relationship between the p-side electrode and the n-side electrode. Therefore, the electric resistance between the electrodes also becomes uniform, and the current flows uniformly in the active region of each laser stripe, so that the light intensity of the laser light emitted from each laser stripe becomes uniform.

Either one of the electrodes described above may be provided independently in each laser stripe, or one of the electrodes described above may be provided as a common electrode of each laser stripe. . In the present invention, by using the p-side electrode and the n-side electrode as a common electrode, the electrode alignment becomes easy when the multi-beam semiconductor laser device is mounted on the submount.

In a preferred embodiment of the present invention, the laser structure is formed as a laminated structure of GaN-based compound semiconductor layers,
Below the contact layer, a plurality of electrode wire / growth masks having a nitride conductive layer as the uppermost layer are spaced apart from each other in the direction parallel to the laser stripe, and under the other of the p-side electrode and the n-side electrode. The electrode line / growth mask functions as an electrode line that reduces the electrical resistance between the p-side electrode and the n-side electrode, and also as a growth mask during selective growth of the contact layer. Function. Further, in the contact layer, for example, the contact layer may be composed of a plurality of layers, and the electrode line / growth mask may be provided on the lowermost layer or a layer below the uppermost layer. The electrode line / growth mask is made of, for example, Ti.
It is formed of a multilayer film having the N layer as the uppermost layer. By providing an electrode wire / growth mask, the electrical resistance between the electrodes is reduced, the flow of current is smoothed, and a GaN-based compound semiconductor layer with good crystallinity in which the vertical crystal axes are aligned is grown. Can be made. Therefore, it is possible to realize a GaN-based semiconductor laser having good laser characteristics, a long life, and high reliability.

The multi-beam semiconductor laser device according to the present invention can be applied regardless of the composition of the substrate and the composition of the compound semiconductor layer constituting the laser structure, and can be preferably applied to, for example, a GaN-based semiconductor laser device. The GaN-based semiconductor laser device is formed on a sapphire substrate or a GaN substrate,
Al _a B _b Ga _c In _d N (a + b + c + d = 1, 0 ≦
This is a semiconductor laser device having layers a, b, c, d ≦ 1) as constituent layers.

In the application of the present invention, there is no restriction on the structure of the optical waveguide, and either the refractive index waveguide type or the gain waveguide type can be applied, and the structure of the laser stripe is not limited.
Either an air ridge type or a buried ridge type may be used. Furthermore, there is no restriction on the current constriction structure, and an insulating film, a high resistance layer,
Alternatively, a current constriction structure by pn junction separation may be used. In addition, the multi-beam semiconductor laser device according to the present invention is suitable as a device that is connected to the submount by a junction down method, and in that case, a first bonding electrode that is electrically bonded to one of the electrodes described above. And a junction-down connection on a submount including a second bonding electrode that is electrically bonded to the common counter electrode.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described specifically and in detail with reference to the accompanying drawings by way of example embodiments. The film forming method, the composition and film thickness of the compound semiconductor layer, the ridge width, the process conditions and the like shown in the following embodiments are merely examples for facilitating the understanding of the present invention. It is not limited to this example. Embodiment 1 This embodiment is an example of an embodiment of a multi-beam semiconductor laser device according to the present invention, and FIG. 1 is a schematic cross-sectional view showing the overall configuration of the multi-beam semiconductor laser device of this embodiment. 2 is a cross-sectional view showing the structure of each laser stripe along line I-I in FIG. 1, and FIG. 3 is a cross-sectional view along line II-II in FIG. The multi-beam semiconductor laser device 40 of the present embodiment example is a GaN-based semiconductor laser device having an SCH structure, and has a plurality of laser stripes 44 on a common sapphire substrate 42.
It is a semiconductor laser device that emits a laser beam from a stripe emission end face 44a of each laser stripe provided on a cleavage plane orthogonal to.

The laser stripes 44 each have a p-side electrode 46 on each ridge and are formed on a common mesa 45 formed on the sapphire substrate 42. Also, n
The side electrode 48 is exposed behind the common mesa 45 as a common counter electrode for the p-side electrode 46, and the laser stripe 4 is exposed.
4 is provided on the contact layer 50 extending in the laser stripe direction from the rear end face side of 4.

As shown in FIG. 2, each laser stripe 44 is an air ridge type laser stripe in which a current is narrowed by a SiO ₂ film 64. Sapphire substrate 42c
N-type GaN contact layer 50 laterally grown from a GaN seed crystal part (not shown) on the surface or on the c-plane of the sapphire substrate 42 via the low-temperature grown GaN buffer layer.
Is deposited. On the n-type GaN contact layer 50, an n-type AlGaN cladding layer 52, an n-type GaN light guide layer 54, an active layer 56, a p-type GaN light guide layer 58, p.
The AlGaN clad layer 60 and the p-type GaN contact layer 62 are sequentially laminated to form a laminated structure. Upper layer of p-type AlGaN cladding layer 60 and p-type G
The aN contact layer 62 is formed as a laser stripe 44 extending in one direction in a ridge stripe shape.

Further, as shown in FIG. 3, the n-type GaN contact layer 50 and the n-type AlGaN cladding layer 5 are provided on the upper layer.
2, n-type GaN light guide layer 54, active layer 56, p-type Ga
The N optical guide layer 58, the lower layer portion of the p-type AlGaN cladding layer 60, and the laser stripe 44 are formed as mesas 45 by etching the rear end surface side of the laser stripe until the n-type GaN contact layer 50 is exposed. That is, the n-type GaN contact layer 50 and the n-type AlG
aN cladding layer 52, n-type GaN light guide layer 54, active layer 56, p-type GaN light guide layer 58, and p-type AlGa
The N-clad layer 60 has a common laminated structure for each laser stripe 44.

The laser stripe 44 is covered with an insulating film 64 made of a SiO ₂ film except for some openings. On the p-type GaN contact layer 62 of each laser stripe 44, Pd / P is formed through the opening of the SiO ₂ film 64.
A p-side electrode 46 of a multi-layer metal film such as a t / Au electrode is provided as an ohmic contact electrode. Also, mesa 45
On the n-type GaN contact layer 50 behind the
n-side electrode 48 of a multilayer metal film such as an l / Pt / Au electrode
Is provided as a common ohmic contact electrode for each laser stripe 44.

In this embodiment, each laser stripe 4
4, the positional relationship between the p-side electrode 46 and the n-side electrode 48 is the same. Therefore, the electric resistance between the electrodes also becomes uniform, and the current flows uniformly in the active region of each laser stripe 44, so that the light intensity of the laser light emitted from each laser stripe 44 becomes uniform.

Embodiment 2 This embodiment is another example of the embodiment of the multi-beam semiconductor laser device according to the present invention, and FIG. 4 shows the structure of the multi-beam semiconductor laser device of this embodiment. It is a perspective view. 4, those parts that are the same as those corresponding parts in FIGS. 1 to 3 are designated by the same reference numerals, and a description thereof will be omitted. The multi-beam semiconductor laser device 70 of the present embodiment is a GaN-based semiconductor laser device having an SCH structure, and comprises an undoped GaN layer and an n-type GaN layer on a sapphire substrate 42, as shown in FIG. n-type GaN / undoped GaN
Layer 72, electrode line / growth mask 74, n-type GaN layer 76 selectively grown using the electrode line / growth mask 74, and n
A type GaN layer 78 is provided.

On the n-type GaN layer 78, n-type AlGaN is formed.
Cladding layer 52, n-type GaN light guide layer 54, active layer 5
6, the p-type GaN optical guide layer 58, the p-type AlGaN cladding layer 60, and the p-type GaN contact layer 62, in that order.
The stacked structure is formed as the mesa 80.
That is, the laminated structure on the n-type GaN layer 78 and the laser stripe 44 are the same as the laminated structure and the laser stripe structure on the n-type GaN contact layer 50 of the first embodiment.

The electrode line / growth mask 74 is a mask in which stripe patterns extending in the <11-20> direction of the c-plane sapphire substrate 42 are arranged in parallel at a predetermined pitch, and as shown in FIG. 6 (a). , Ti film (lower layer) 74a and TiN film (upper layer) 74b are formed as a laminated metal film.

Instead of the laminated metal film composed of the Ti layer and the TiN layer, a first film composed of an oxide or a metal, a second film composed of a nitride and an oxide or a metal, and a conductive nitride. An electrode line / growth mask may be configured with the third film. Specifically, the first film is, for example, SiO.
_{The second} film, such as a ₂ film, a Ti film, or a Pt film, may be S, for example.
iN _1-x O _x (where 0 <x <1) film, Ti film and Pt
As the third film such as a film, for example, a TiN film or a SiN film is used. Since the laminated metal film functions as an electrode line / growth mask, at least one of the first film and the third film needs to be conductive. For example,
When a metal film such as a Ti film or a Pt film is used as the first film, the third film is, for example, a TiN film or SiN film.
Any of the films may be used, but SiO ₂ is used as the first film.
When an oxide film such as a film is used, it is necessary to use a conductive TiN film as the third film.

Further, as described above, the laminated structure on the n-type GaN layer 78 is formed as the mesa 80 by etching the rear end face side of the laser stripe until the n-type GaN layer 78 is exposed, as shown in FIG. Has been done. Exposed n
An n-side electrode 48 is formed on the type GaN layer 78.

In the multi-beam semiconductor laser device of this embodiment, the electrode wire / growth mask 74 is a laminated metal film of a Ti layer and a TiN layer.
When a current is passed between the side electrode 48 and this side electrode, this current is
Flow through the low resistance electrode wire / growth mask 74 as shown in FIG. As a result, the operating voltage can be reduced without affecting the operating voltage such as the thickness and carrier concentration of the n-type GaN / undoped GaN layer 72 and the n-type GaN layers 76 and 78.

The current flows through the n-type GaN contact layer 50, which has a higher specific resistance than that of metal or TiN, and the thickness and carrier concentration of the n-type GaN contact layer 50 affect the operating voltage of the first embodiment. Compared with the beam semiconductor laser device 40, the multi-beam semiconductor laser device 70 of the second embodiment has a more uniform light intensity of the laser light emitted from each laser stripe, and operates more easily with a high light output.

As a modification of the second embodiment, when forming a mesa, an n-type GaN layer 78 and an n-type GaN layer 76 are further added.
Is etched to grow the electrode line / growth mask 74 and the n-type G
The aN / undoped GaN layer 72 is exposed, and the electrode line / growth mask 74 and the n-type GaN / undoped GaN layer 72 are also exposed.
The n-side electrode 48 may be formed on top.

A method of manufacturing the multi-beam semiconductor laser device according to the second embodiment will be described with reference to FIGS. FIGS. 6A to 6C are cross-sectional views for each step when manufacturing the multi-beam semiconductor laser device of the second embodiment. As shown in FIG. 6A, undoped Ga is formed on the c-plane sapphire substrate 42 by MOCVD or the like.
An n-type GaN / undoped GaN layer 72 including an N layer and an n-type GaN layer is grown. Next, a laminated metal film is deposited from the Ti layer 74a and the TiN layer 74b on the n-type GaN / undoped GaN layer 72 by a sputtering method or the like.

Next, as shown in FIG. 6B, a stripe-shaped resist pattern 75 extending in a direction parallel to the stripe direction of the laser stripe 44 is formed on the TiN film 74b at a predetermined cycle. This resist pattern 75
Is the same as the stripe direction of the laser stripe 44, for example, <11- of the c-plane sapphire substrate 42.
It is a direction parallel to the 20> direction.

Next, using the resist pattern 75 as a mask, a dry etching method such as a reactive ion etching (RIE) method or a wet etching method using a hydrofluoric acid-based etching solution is used to form the TiN layer 74b. Then, the Ti layer 74a is sequentially etched to form an electrode line / growth mask 74 composed of the Ti layer 74a and the TiN layer 74b as shown in FIG. 6C. The width of the electrode / growth mask 74 can be selected as required, and for example, 4.
8 μm or less. After removing the resist pattern 75, as shown in FIG. 6C, the n-type GaN layer 76 is selectively grown by MOCVD.

At the time of growth, in order to favorably perform selective growth, it is preferable to adjust the supply amount of the raw material so that the growth rate is 6 μm or less. Further, the substrate temperature is, eg, 500 ° C. or higher and 1200 ° C. or lower. This is 500 ℃
At a low temperature of less than 1, it is not possible to give sufficient migration energy to the raw material supplied to the surface of the substrate on which the electrode wire / growth mask 74 is formed.
This is because the aN layer cannot be grown, and at a temperature higher than 1200 ° C., the sticking coefficient of the raw material is too low to secure a sufficient growth rate.

In this way, the electrode line / growth mask 74 is formed.
Selective growth occurs on the n-type GaN / undoped GaN layer 72 in which the n-type GaN is formed, and an n-type GaN layer 76 having good crystallinity, in which the distribution of the crystal axis in the vertical direction is extremely small, is obtained as a continuous film. To be

Next, as shown in FIG. 5, the n-type GaN layer 7 is formed.
6 on the n-type GaN layer 78, the n-type AlGaN cladding layer 52, the n-type GaN light guide layer 54, the active layer 56, and the p-type GaN light guide layer 58 by MOCVD.
The p-type AlGaN cladding layer 160 and the p-type GaN contact layer 62 are sequentially grown. At this time, since the n-type GaN layer 76 which is the base of these layers is a high-quality single crystal with a low crystal defect density, these layers are also a high-quality single crystal with a low crystal defect density.

Next, the p-type GaN contact layer 62 and p
The upper layer of the AlGaN clad layer 60 is etched to form a plurality of laser stripes 44. Furthermore,
Laser stripe 44, p-type AlGaN cladding layer 60
Lower layer portion, p-type GaN light guide layer 58, active layer 56, n
The rear end face side of the laser stripes of the n-type GaN light guide layer 54 and the n-type AlGaN cladding layer 52 is, for example, RIE.
Method is performed until the n-type GaN layer 78 is exposed to form the mesa 80, and the n-type GaN layer 78 is exposed on the rear end face side of the laser stripe.

Next, the p-type Ga of each laser stripe 44 is
A p-side electrode 46 is formed on the N contact layer 60, and an n-side electrode 48 is formed on the n-type GaN layer 78 behind the mesa. As shown in FIG. 5, a current flows from the n-side electrode 48 through the n-type GaN layer 78 and the n-type GaN layer 76 to the stacked structure of the mesas 80 via the electrode wire / growth mask 74, and the stacked mesas 80 are stacked. It flows uniformly to the p-side electrode 46 through the structure.

As described above, according to the second embodiment, the n-type GaN having good crystallinity in which the vertical crystal axes are aligned by the selective growth using the electrode line / growth mask 74.
Ga growing a layer 76 and forming a laser structure thereon
By growing the N-based semiconductor layer, it is possible to realize a GaN-based semiconductor laser having excellent characteristics, a long life, and high reliability.

Embodiment 3 This embodiment is another example of the embodiment of the multi-beam semiconductor laser device according to the present invention, and FIG. 7 shows the structure of the multi-beam semiconductor laser device 90 of this embodiment. FIG. As shown in FIG. 7, a multi-beam semiconductor laser device 90 of the present embodiment is a semiconductor in which the multi-beam semiconductor laser device 40 or 70 of the first embodiment or the second embodiment is mounted on a submount 92 by a junction down method. It is a laser device. Submount 9
Reference numeral 2 denotes a member made of AlN, which has a first joint surface 94 and a second joint surface 96 having a step corresponding to the height of the mesa 45 or 80 of the multi-beam semiconductor laser device 40 or 70, and the first joint surface 94. And the vertical wall 9 between the second joint surface 96 and
Have eight.

On the first joint surface 94, first joint electrodes 100 are provided which are electrically and mechanically connected to the p-side electrodes 46 of the laser stripes 44, respectively. Further, on the second joint surface 96, the second joint electrode 102 that is electrically and mechanically connected to the n-side electrode 48 is provided. Further, on the vertical wall 98, in order to control the light intensity of the emitted laser light of each laser stripe 44, a photodiode 104 that receives the laser light emitted from the rear end face of the laser stripe and detects the light intensity is provided. ,Each,
It is provided at a position facing the rear end surface of the laser stripe 44. When the p-side electrode 46 is provided as a common electrode of the laser stripes 44, one photodiode 104 may be provided as a common light intensity detector.

In the present embodiment, since the light intensity detector of the laser light can be provided on the vertical wall 98 of the submount 92, the entire multi-beam semiconductor laser device 90 including the submount can be downsized. .

[0040]

According to the present invention, the common counter electrode facing the electrode on the laser stripe is exposed on the back side of the common mesa and on the contact layer extending in the laser stripe direction from the rear end face side of the laser stripe. Since they are provided, the positional relationship between the electrodes on each laser stripe and the common counter electrode is the same. As a result, the electric resistance between the electrodes becomes uniform, and it is possible to emit laser beams having the same light intensity from each laser stripe. In addition, a plurality of electrode wire / growth masks having a nitride conductive layer as an uppermost layer are separated from each other in a direction parallel to the laser stripe to extend from below the other of the p-side electrode and the n-side electrode to below the laser stripe. By extending it, the electrical resistance between the electrodes can be reduced, and the multi-beam semiconductor laser device can be operated at a low operating voltage. Further, by using the electrode line / growth mask as a growth mask in the selective growth of the contact layer, a contact layer having good crystallinity in which crystallographic orientations in the vertical direction are aligned is grown, and a good laser characteristic is obtained. A multi-beam semiconductor laser device can be realized.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an overall configuration of a multi-beam semiconductor laser device according to a first embodiment.

FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1, showing a structure of each laser stripe of the multi-beam semiconductor laser device of the first embodiment.

3 is a cross-sectional view taken along the line II-II in FIG. 1, showing a structure of a mesa of the multi-beam semiconductor laser device of the first embodiment.

FIG. 4 is a schematic perspective view showing an overall configuration of a multi-beam semiconductor laser device according to a second embodiment.

5 is a sectional view taken along line III-III in FIG.

6 (a) to 6 (c) are cross-sectional views for each step in manufacturing the multi-beam semiconductor laser device of the second embodiment.

FIG. 7 is a schematic perspective view showing an overall configuration of a multi-beam semiconductor laser device according to a third embodiment.

FIG. 8 is a development view showing a configuration of a multi-beam semiconductor laser device of a first conventional example.

FIG. 9 is a development view showing a configuration of a multi-beam semiconductor laser device of a second conventional example.

[Explanation of symbols]

10 ... Multi-beam semiconductor laser device of the first conventional example,
12 ... Substrate, 14 ... Laser oscillator, 16 ... Electrode,
17 ... Counter electrode, 18 ... Contact electrode, 20 ...
... Wiring, 22 ... Arranged substrate, 24 ... Multi-beam semiconductor laser device of the second conventional example, 26 ... Substrate, 28 ... Laser oscillator, 30 ... Electrode, 31 ... Counter electrode, 32 ...
Contact electrode, 34 wiring, 36 arrangement substrate, 40 multi-beam semiconductor laser device of the first embodiment, 42 substrate, sapphire substrate, 44 laser stripe, 45 mesa, 46 ... p-side electrode, 48 ...
... n-side electrode, 50 ... n-type GaN contact layer, 52 ...
... n-type AlGaN clad layer, 54 ... n-type GaN light guide layer, 56 ... active layer, 58 ... p-type GaN light guide layer, 60 ... p-type AlGaN clad layer, 62 ... p-type GaN contact layer , 64 ... SiO ₂ film, 70 ... Multi-beam semiconductor laser device of the second embodiment, 72 ...
n-type GaN / undoped GaN layer, 74 ... Electrode wire / growth mask, 76 ... n-type GaN layer, 78 ... n-type GaN
Layer, 80 ... Mesa, 90 ... Multi-beam semiconductor laser device of the third embodiment, 92 ... Submount, 94 ...
First joint surface, 96 ... Second joint surface, 98 ... Vertical wall, 10
0 ... first bonding electrode, 102 ... second bonding electrode, 104
……Photodiode.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshifumi Yabuki             3-53-2, Shiratori, Shiroishi, Miyagi Prefecture Sony             Shiraishi Semiconductor Co., Ltd. (72) Inventor Shinichi Anzai             3-53-2, Shiratori, Shiroishi, Miyagi Prefecture Sony             Shiraishi Semiconductor Co., Ltd. (72) Inventor Tsuyoshi Tojo             3-53-2, Shiratori, Shiroishi, Miyagi Prefecture Sony             Shiraishi Semiconductor Co., Ltd. (72) Inventor Shiro Uchida             3-53-2, Shiratori, Shiroishi, Miyagi Prefecture Sony             Shiraishi Semiconductor Co., Ltd. (72) Inventor Masao Ikeda             3-53-2, Shiratori, Shiroishi, Miyagi Prefecture Sony             Shiraishi Semiconductor Co., Ltd. F-term (reference) 5F073 AA20 AA46 AB04 BA06 BA07                       CA07 CB05 CB22 DA07 DA32                       EA29

Claims (5)

[Claims] 1. A multi-beam semiconductor laser device having a plurality of laser stripes on a common substrate, wherein a laser beam is emitted from a stripe emission end face of each laser stripe provided on a cleavage plane orthogonal to the laser stripe. The laser stripes each have a p-side electrode or an n-side electrode on each ridge stripe, are formed on a common mesa formed on the substrate, and face each one of the electrodes. As the common counter electrode, the other of the p-side electrode and the n-side electrode is provided behind the common mesa and provided on the contact layer extending in the laser stripe direction from the rear end face side of the laser stripe. And a multi-beam semiconductor laser device. 2. A laser structure is formed as a laminated structure of GaN-based compound semiconductor layers, and a plurality of electrode line / growth masks having a nitride conductive layer as an uppermost layer are arranged below the contact layer in parallel with the laser stripe. In a direction from each other, extending from below the other of the p-side electrode and the n-side electrode to below the laser stripe. The electrode wire / growth mask serves to reduce the electrical resistance between the p-side electrode and the n-side electrode. The multi-beam semiconductor laser device according to claim 1, wherein the multi-beam semiconductor laser device functions as an electrode line for mitigating and a growth mask during selective growth of a contact layer. 3. A laser structure is formed as a laminated structure of GaN-based compound semiconductor layers, and a plurality of electrode wire / growth masks having a nitride conductive layer as an uppermost layer in a contact layer are formed in a direction parallel to a laser stripe. And extends from below the other of the p-side electrode and the n-side electrode to below the laser stripe. The electrode wire / growth mask reduces the electrical resistance between the p-side electrode and the n-side electrode. 2. The multi-beam semiconductor laser device according to claim 1, wherein the multi-beam semiconductor laser device functions as an electrode line for forming a contact layer and a growth mask during selective growth of the contact layer. 4. The multi-beam semiconductor laser device according to claim 2, wherein the electrode line / growth mask is formed of a multilayer film having a TiN layer as an uppermost layer. 5. A junction-down connection is provided on a submount that includes a first bonding electrode that is electrically bonded to one of the electrodes and a second bonding electrode that is electrically bonded to the common counter electrode. The multi-beam semiconductor laser device according to any one of claims 1 to 4, wherein