JP2003031895A - Semiconductor light emitting device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light emitting device which has a sufficient lifetime and high reliability and which can reduce the defect ratio and to provide a method for manufacturing the same. SOLUTION: The semiconductor light emitting device comprises a mounting member 10, and semiconductor light emitting element chips 1 to 4 installed on the member 10 and including nitride compound semiconductors in such a manner that main surfaces of the chips 1 to 4 each has a curved surface. Thus, shapes of the chips 1 to 4 installed on the member 10 are adapted that the main surfaces of the chips 1 to 4 each consciously has a curved surface (in a warped state) and hence the lifetime of the emitting device can be prolonged. Thus, the shapes of the chips 1 to 4 after mounting are managed, and thereby the defective ratio of the emitting device can be reduced, and reliability of the device can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device and a method for manufacturing the same, and more particularly to a semiconductor light emitting device and a method for manufacturing the same capable of extending the life. In this specification, a semiconductor light emitting device is a semiconductor light emitting device chip such as a semiconductor laser chip or an LED chip that is mounted on a mount member and integrated.

[0002]

2. Description of the Related Art GaN-based semiconductors are semiconductor light emitting device chips (semiconductor laser chips) in the ultraviolet or green region.
Has attracted attention as a material that realizes. Especially, this Ga
It is desired to put into practical use a semiconductor laser device that oscillates in a shorter wavelength region than before by using an N-based semiconductor.

When a semiconductor laser chip is manufactured using the above-mentioned GaN-based semiconductor, sapphire which is an insulator is used as the substrate of the semiconductor laser chip. However, recently, a semiconductor laser chip in which an n-type semiconductor layer, an active layer, a p-type semiconductor layer, an electrode and the like are sequentially formed on a GaN substrate has been studied. Such a semiconductor laser chip is used as a semiconductor laser device (semiconductor light emitting device) while being fixed to a holder made of iron (Fe) or copper (Cu) called a stem.

When the semiconductor laser device as described above is put to practical use, it is required to improve its reliability. As one example of the technology for improving the reliability of the semiconductor laser device, between the semiconductor laser chip and the stem,
A technique of interposing a submount made of a material having a large thermal conductivity is known. In such a technique, there is known a so-called junction down structure in which die bonding is performed with the semiconductor layer side of the semiconductor laser chip, which has a large amount of heat generation, facing the submount (on the other hand, the substrate side of the semiconductor laser chip). The structure that performs die bonding with the submount facing is called a junction up). In such a junction down structure, when the semiconductor laser device is operated, the heat generated in the semiconductor laser chip is efficiently dissipated to the holder such as the stem (improves the heat dissipation characteristic).
As a result, it is possible to suppress the temperature rise of the light emitting portion of the semiconductor laser chip and the deterioration of the characteristics of the semiconductor laser chip due to the temperature rise. An example of a semiconductor laser device having such a junction down structure is disclosed in Japanese Patent Laid-Open No. 2000-58965.

20 and 21 are schematic sectional views showing a conventional semiconductor laser device. The conventional semiconductor laser device shown in FIGS. 20 and 21 is one in which a semiconductor laser chip having a single-sided electrode structure is die-bonded to a submount by junction down. Referring to FIG. 20,
In the conventional semiconductor laser device, the semiconductor laser chip 11
7 is mounted on a holder (submount) 140. On the surface of the holder 140, the semiconductor laser chip 11
Metal film patterns 141 and 142 are formed so as to correspond to the positive and negative electrodes of No. 7, respectively. Metal film pattern 1
The semiconductor laser chip 117 is fixed on the electrodes 41 and 142 by a conductive bonding material 143 such as solder. The semiconductor laser chip 117 includes a substrate 131 and the substrate 13
Semiconductor layers 132, 133, 13 formed on the surface of
4 and. Semiconductor laser chip 117 and holder 14
The filling material 144 is arranged so as to fill the space between 0 and 0. In the semiconductor laser device shown in FIG. 20, junction down die bonding is realized.

The die bonding is generally the following process. That is, usually, solder is provided in advance on the surface of the holder. Then, after placing the semiconductor laser chip at a predetermined position on the solder, the holder is heated to a temperature higher than the melting point of the solder. In this state, the semiconductor laser chip is pressed against the holding pair by the collet as the pressing member. As a result, the solder becomes compatible with the semiconductor laser chip and the surface of the holder. Then, the solder is cooled and solidified. In this way, the semiconductor laser chip and the holder are bonded together with good thermal conductivity.

Further, referring to FIG. 21, another example of a conventional semiconductor laser chip is a conductive substrate 151 made of GaN or the like, and a semiconductor layer formed by laminating on one surface of the substrate 151. 152 to 154, an insulating film 157 formed on the semiconductor layer 154, and an electrode 1 formed on the insulating film
58, and an electrode 156 formed on the back surface side of the substrate 151. The conventional semiconductor laser chip shown in FIG.
This is a semiconductor laser chip having a double-sided electrode structure using a conductive substrate 151. The above-mentioned Japanese Patent Laid-Open No. 2000-58965 discloses a semiconductor laser chip shown in FIG.
As with the semiconductor laser device shown in FIG. 0, it is suggested that junction down die bonding can be performed.

[0008]

However, the above-mentioned conventional semiconductor laser device has the following problems. That is, after preparing semiconductor laser chips that have similar semiconductor layer materials formed on the substrate and electrical characteristics before mounting on the holder, mount these semiconductor laser chips on submounts, stems, etc., respectively. When a semiconductor laser device is created in this way, many semiconductor laser devices with extremely short lives are created.

The defective rate of the semiconductor laser device is
For example, it is defined as follows. First, set the ambient temperature to 20
When the aging test is performed under the conditions of the temperature of 5 ° C. and the output of 5 mW, the integrated time at the time when the value of the driving current of the semiconductor laser device at the output of 5 mW becomes 150 mA or more,
It is defined as the life of the semiconductor laser device. Then, the life of the plurality of samples of the semiconductor laser device is 50
The percentage of products that are less than 00 hours is defined as the defective product rate.
Considering the defective product rate defined in this way, in the conventional semiconductor laser device, the defective product ratio is as high as 20% or more even if the electrical characteristics of the semiconductor laser chip as a component are made uniform to some extent as described above. It may have been a large value. When the defective product ratio is increased as described above, the manufacturing cost of the semiconductor laser device (semiconductor light emitting device) is increased.

The present invention has been made to solve the above problems, and an object of the present invention is to have a sufficient life and to reduce the defective product rate and reliability. It is an object of the present invention to provide a high-performance semiconductor light emitting device and a manufacturing method thereof.

[0011]

The inventor has completed the present invention as a result of conducting the following tests and studies on a semiconductor light emitting device. That is, the inventor has found that even if the semiconductor laser chip constituting the semiconductor light emitting device is mounted on a stem or a submount, the semiconductor film configuration and the electrical characteristics before mounting are similar, various semiconductor laser chips may be used. It was noticed that there are various shapes such as those having a warped shape (the main surface having a curved surface) and those having almost no warpage. It is considered that this is due to the influence of the conditions when the back surface side of the substrate forming the semiconductor laser chip is polished, the patterning conditions of the semiconductor film formed on the substrate, and the like in the process of forming the semiconductor laser chip.

In the conventional semiconductor light emitting device, these semiconductor laser chips are mounted on the flat surface of the submount or the stem. The shape of the semiconductor laser chip after being mounted on the submount or the stem has not been considered in the past.

Therefore, the inventor has found that the shape of the semiconductor laser chip after being mounted on the submount or the stem is
(1) A sample of the semiconductor laser device in which the semiconductor laser chip is warped so that the substrate side is convex (the main surface has a curved surface), (2) A sample of the semiconductor laser device in a substantially flat state, (3) ) Three types of samples, that is, a sample in a state in which the semiconductor film side of the semiconductor laser chip is curved so as to be convex (the sample is curved in the opposite direction to the sample in (1) above), were prepared, and the life of each sample was evaluated. . As a result, there was a tendency that the sample (1) had the longest life, and conversely, the sample (3) had the shortest life.

From this fact, the shape of the semiconductor laser chip after being mounted on the submount or the stem is intentionally warped, and in particular, the semiconductor laser chip is intentionally warped so that the substrate side is convex. By making it possible (the semiconductor laser chip is mounted on a submount etc. so that the main surface of the semiconductor laser chip has a curved surface that is convex toward the substrate side), it is possible to prevent shortening of the life of the semiconductor light emitting device. At the same time, we thought that the defective product rate could be reduced. Further, as a result of examination by the inventor, if the substrate side of the semiconductor laser chip can be curved so as to be convex,
It was found that mounting the semiconductor laser chip on a submount, a stem, or the like with either a junction-down structure or a junction-up structure can prevent shortening the life of the semiconductor light emitting device.

Based on the above findings of the inventor, the semiconductor light emitting device according to one aspect of the present invention includes a mount member, and a semiconductor light emitting element chip installed on the mount member and containing a nitride-based compound semiconductor. And the main surface of the semiconductor light emitting element chip has a curved surface.

As described above, regarding the shape of the semiconductor light emitting element chip installed on the mount member, the semiconductor light emitting element chip is intentionally made to have a curved surface on the main surface thereof (in a warped state). It is possible to extend the life of the device.

Further, by controlling the shape of the semiconductor light emitting element chip after mounting in this manner, the defective product rate of the semiconductor light emitting device can be reduced and the reliability of the semiconductor light emitting device can be improved.

In the semiconductor light emitting element chip, when a ridge portion or the like is formed on the surface of the functional layer, the curved surface may be arranged in any way with respect to the ridge portion. When the semiconductor light emitting element chip itself is warped to form the curved surface, the direction of the warpage may be a direction substantially perpendicular to the extending direction of the ridge portion. The direction that is inclined to the existing direction,
Any other direction may be used.

However, when the semiconductor light emitting element chip is bent in the same direction as the extending direction of the ridge portion, bending of the waveguide may cause an increase in optical loss. Therefore, the warp of the semiconductor light emitting element chip is reduced in the same direction as the extending direction of the ridge portion, while the warp of the semiconductor light emitting element chip is increased in the direction substantially perpendicular to the extending direction of the ridge portion. (Warp is given in a direction perpendicular to the ridge portion).

Further, in this case, when the warp is given in the direction perpendicular to the ridge portion, the light emitting direction becomes substantially linear in the semiconductor light emitting element chip. Therefore, the existing mount member can be used as a member constituting the semiconductor light emitting device according to the present invention. Therefore, the cost required for designing the semiconductor light emitting device can be reduced. Further, since the semiconductor light emitting device according to the present invention can be realized without preparing a mount member having a new structure, it is possible to suppress an increase in manufacturing cost of the semiconductor light emitting device.

In the present specification, the mount member means a component for directly mounting the semiconductor light emitting element chips. For example, a submount for a semiconductor light emitting device chip is included in the mount member. When the semiconductor light emitting element chip is directly mounted on a holder (stem, frame, package, etc.) without using the submount, the holder is included in the mount member.

As a material forming the mount member, a generally known heat dissipation material can be used. For example, silver (A
g), copper (Cu), CuW, BeO, iron (Fe), alumina (Al ₂ O ₃ ), silicon (Si), aluminum nitride (AlN), silicon carbide (SiC), boron nitride (cB)
N), CuMo, diamond, etc. can be used.

When arranging the semiconductor light emitting element chip on the mount member, solder can be used for joining the mount member and the semiconductor light emitting element chip. As the material of the solder, indium (In), InPb, In
In-containing alloys such as Sn, InAg and InAgPb,
Alternatively, tin (Sn), SnPb, SnSb, SnA
Examples thereof include Sn-containing alloys such as g, SnAgPb, SnAgCu, and SnPbSb, and epoxy resins and polyimide resins mixed with powders of Ag, gold (Au), Cu, and the like. The melting points of these materials are approximately 100 ° C.
It is about 235 ° C. Examples of the solder material having a higher melting point include AuSi, AuSn, AuGa and A.
uGe, AuSb, AuNi, AuIn, AuAgSn
Examples include alloys containing Au. The melting point of these materials is about 280 ° C. or higher.

In the semiconductor light emitting device according to the above aspect, the semiconductor light emitting element chip may include a substrate and a functional layer formed on the substrate and having a nitride compound semiconductor. The main surface of the semiconductor light emitting element chip preferably has a curved surface such that the substrate side is convex when viewed from the functional layer.

In this case, it is possible to effectively extend the life of the semiconductor light emitting device and reduce the defective product rate.

In the semiconductor light emitting device according to the above aspect 1, the radius of curvature of the curved surface is 0.
It is preferably 2 times or more and 10 times or less. Further, the radius of curvature of the curved surface is more preferably 0.2 times or more and 5 times or less the width of the semiconductor light emitting element chip.

In this case, the life of the semiconductor light emitting device can be reliably extended. Here, when the curvature of the curved surface on the main surface of the semiconductor light emitting device chip is smaller than 0.2 times the width of the semiconductor light emitting device chip, the semiconductor light emitting device chip may be broken or the semiconductor film may be peeled off from the substrate. The probability of occurrence increases, and the defective product rate of the semiconductor light emitting device increases.

Further, when the curvature of the curved surface on the main surface of the semiconductor light emitting element chip is 10 times or less the width of the semiconductor light emitting element chip, or when the semiconductor light emitting element chip is not warped (a curved surface is formed on the main surface thereof). If not), the defective product rate can be reduced. Further, when the curvature of the curved surface is 5 times or less the width of the semiconductor light emitting element chip, the defective product rate can be set to a low value of 10% or less.

A semiconductor light emitting device according to another aspect of the present invention comprises a mount member including a convex portion having a convex surface, and a semiconductor light emitting element chip provided on the convex portion of the mount member.

In this case, by disposing the semiconductor light emitting element chip on the convex portion of the mount member along the convex shape, a state in which a curved surface is formed on the main surface of the semiconductor light emitting element chip (semiconductor light emitting element) (The chip is warped)
Can be easily realized.

In the semiconductor light emitting device according to another aspect, the main surface of the semiconductor light emitting element chip may have a curved surface that follows the surface shape of the convex portion of the mount member.

In this case, by changing the outer shape of the convex portion of the mount member, the shape of the curved surface of the semiconductor light emitting element chip can be changed according to the outer shape of the convex portion.
Therefore, the radius of curvature of the curved surface of the semiconductor light emitting element chip can be arbitrarily changed.

A semiconductor light emitting device according to another aspect of the present invention includes a mount member including a concave portion having a concave surface, and a semiconductor light emitting element chip installed on the concave portion of the mount member.

In this case, by disposing the semiconductor light emitting element chip on the concave portion of the mount member along the concave shape, a curved surface is formed on the main surface of the semiconductor light emitting element chip (semiconductor light emitting element). (The chip is warped)
Can be easily realized.

In the semiconductor light emitting device according to the other aspect described above, the main surface of the semiconductor light emitting element chip may have a curved surface along the surface shape of the concave portion of the mount member.

In this case, by changing the outer shape of the concave portion of the mount member, the shape of the curved surface of the semiconductor light emitting element chip can be changed according to the outer shape of the concave portion.
Therefore, the radius of curvature of the curved surface of the semiconductor light emitting element chip can be arbitrarily changed.

According to another aspect of the present invention, there is provided a semiconductor light emitting device comprising a mount member including a chip mounting portion having a plurality of protrusions formed on a surface thereof, and a semiconductor light emitting element chip mounted on the chip mounting portion of the mount member. With.

In this case, by disposing the semiconductor light emitting element chip on the chip mounting portion of the mount member so as to be supported by the plurality of protrusions of the chip mounting portion, a curved surface is formed on the main surface of the semiconductor light emitting element chip. The semiconductor light emitting element chip can be mounted on the mount member while maintaining the open state (the state where the semiconductor light emitting element chip is warped).

In the semiconductor light emitting device according to the other aspect, the main surface of the semiconductor light emitting element chip may have a curved surface which is convex toward the mount member side on the chip mounting portion of the mount member.

In this case, if the curved surface portion (convex portion) located closest to the mount member in the semiconductor light emitting element chip is located between the plurality of protrusions formed on the mount member, the semiconductor light emitting element A region surrounding the convex portion of the chip can be supported by a plurality of protrusions of the mount member. Therefore, the state where the main surface of the semiconductor light emitting element chip has a curved surface (warped state) can be reliably maintained.

A method of manufacturing a semiconductor light emitting device according to still another aspect of the present invention includes a step of preparing a mount member and an installation step of installing a semiconductor light emitting element chip on the mount member. The main surface has a curved surface.

In this way, the semiconductor light emitting device according to the one aspect of the present invention can be easily manufactured.

In the method for manufacturing a semiconductor light emitting device according to still another aspect, the semiconductor light emitting element chip may include a substrate and a semiconductor functional layer formed on the substrate and having a light emitting function. The step of preparing the mount member may include the step of preparing a mount member including a convex portion having a convex surface. In the installation step, the semiconductor light-emitting element chip is such that the semiconductor functional layer of the semiconductor light-emitting element chip faces the convex portion and the main surface of the semiconductor light-emitting element chip has a curved surface along the surface of the convex portion of the mount member. May be included.

In this case, the semiconductor light emitting element chip is mounted in a so-called junction down state on the convex portion of the mount member. In addition, by mounting the semiconductor light emitting element chip on the convex portion with the junction down in this way, the semiconductor light emitting element chip can be curved so that the substrate side becomes convex (a curved surface such that the substrate side becomes convex). Can be formed). As a result, it is possible to easily obtain a semiconductor light emitting device that can have a long life.

In the method for manufacturing a semiconductor light emitting device according to the still another aspect, in the installing step, the semiconductor light emitting element chip is pressed against the convex portion of the mount member by using the pressing member having the pressing portion having a concave surface. It may include a pressing step.

In this case, the shape of the curved surface of the semiconductor light emitting element chip can be surely made to conform to the outer shape of the convex portion of the mount member. Therefore, by changing the outer shape of the convex portion of the mount member, the shape of the curved surface of the semiconductor light emitting element chip can be arbitrarily changed.

In the method of manufacturing a semiconductor light emitting device according to still another aspect, the surface of the concave pressing portion of the pressing member may have a curved surface, and the radius of curvature of the curved surface of the pressing member is on the mount member. It may be substantially equal to the radius of curvature of the curved surface of the main surface of the semiconductor light emitting device chip to be installed.

In this case, the curved surface of the semiconductor light emitting element chip can be easily molded into a desired shape by pressing the semiconductor light emitting element chip with the pressing member.

In the method for manufacturing a semiconductor light emitting device according to still another aspect, the width of the pressing portion of the pressing member may be smaller than the width of the semiconductor light emitting element chip, and the pressing step is performed by the pressing portion of the pressing member. It may include pressing the semiconductor light emitting element chip arranged on the convex shaped portion of the above plural times.

In this case, in the pressing step, the pressing member can be pressed against the semiconductor light emitting element chip so as to avoid a region where stress is not desired to be applied, such as a ridge portion of the semiconductor light emitting element chip. Therefore, it is possible to prevent the characteristics of the semiconductor light emitting element chip from deteriorating in the pressing step.

In the method for manufacturing a semiconductor light emitting device according to the still another aspect, the semiconductor light emitting element chip includes a substrate,
A semiconductor functional layer having a light emitting function and formed on the substrate may be included, and the step of preparing the mount member includes the step of preparing a mount member including a concave portion whose surface is concave. The step of installing the semiconductor light emitting element chip substrate may face the concave portion,
It may include installing the semiconductor light emitting element chip in a state where the main surface of the semiconductor light emitting element chip has a curved surface along the surface of the concave portion of the mount member.

In this case, the semiconductor light emitting element chip is mounted in a so-called junction-up manner in the concave portion of the mount member. Further, by mounting the semiconductor light emitting element chip on the concave portion by increasing the junction, the semiconductor light emitting element chip can be curved so that the substrate side becomes convex (a curved surface such that the substrate side becomes convex). Can be formed). As a result, it is possible to easily obtain a semiconductor light emitting device that can have a long life.

In the method for manufacturing a semiconductor light emitting device according to the still another aspect, in the installing step, the semiconductor light emitting element chip is pressed against the concave portion of the mount member by using the pressing member having the pressing portion having a convex surface. It may include a pressing step.

In this case, the shape of the curved surface of the semiconductor light emitting element chip can be made to conform to the outer shape of the concave portion of the mount member. Therefore, the shape of the curved surface of the semiconductor light emitting element chip can be arbitrarily changed by changing the outer shape of the concave portion of the mount member.

In the method for manufacturing a semiconductor light emitting device according to still another aspect, the surface of the convex pressing portion of the pressing member may have a curved surface, and the radius of curvature of the curved surface of the pressing member is on the mount member. It may be substantially equal to the radius of curvature of the curved surface of the main surface of the semiconductor light emitting device chip to be installed.

In this case, the curved surface of the semiconductor light emitting element chip can be easily molded into a desired shape by pressing the semiconductor light emitting element chip with the pressing member.

In the method for manufacturing a semiconductor light emitting device according to still another aspect, a groove may be formed in the pressing portion of the pressing member.

At this time, when a ridge portion is formed in the semiconductor functional layer of the semiconductor light emitting device chip, a pressing member is arranged so that the groove overlaps the position of the ridge portion, and the pressing step is performed. It is possible to prevent unnecessary stress from being applied to the ridge portion by the pressing member. Therefore, it is possible to prevent the characteristics of the semiconductor light emitting element chip from deteriorating due to the unnecessary stress.

In the method of manufacturing a semiconductor light emitting device according to the still another aspect, the width of the pressing portion of the pressing member may be smaller than the width of the semiconductor light emitting element chip, and the pressing step is performed by the pressing portion of the pressing member. It may include pressing the semiconductor light emitting element chip arranged on the concave portion of the above plural times.

In this case, in the pressing step, the pressing member may be pressed against the semiconductor light emitting element chip arranged on the concave portion so as to avoid a region where stress is not desired to be applied, such as a ridge portion of the semiconductor light emitting element chip. it can. Therefore, it is possible to prevent the characteristics of the semiconductor light emitting element chip from deteriorating in the pressing step.

[0061]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts will be denoted by the same reference numerals and the description thereof will not be repeated.

(Embodiment 1) FIG. 1 is a schematic sectional view showing Embodiment 1 of a semiconductor laser device according to the present invention. A first embodiment of a semiconductor laser device according to the present invention will be described with reference to FIG.

Referring to FIG. 1, a semiconductor laser device as a semiconductor light emitting device includes a GaN substrate 1 and a nitride-based semiconductor laminate 2 (hereinafter also referred to as a laminate) formed on the GaN substrate 1. And an n electrode 4 formed on the surface of the GaN substrate 1 opposite to the surface on which the laminate 2 as a functional layer or a semiconductor functional layer is formed, and formed on the nitride semiconductor laminate 2. And the p-electrode 3 is formed. As described above, the GaN substrate 1, the nitride-based semiconductor laminate 2, the p-electrode 3 and the n-electrode 4 are the basic elements that constitute the semiconductor laser chip used in the semiconductor laser device according to the present invention. A more detailed structure of the semiconductor laser chip as the semiconductor light emitting device chip will be described later.

The semiconductor laser chip is fixed and stacked with the p-electrode 3 on the surface of the submount 10 having the metal multi-layer film 15 formed on the surface thereof by using the solder 12. In the submount 10, a metal multilayer film 15 is formed on the surface on which the semiconductor laser chip is mounted and on the surface opposite to the surface on which the semiconductor laser chip is mounted. The metal multilayer film 15 is formed for metallization. The submount 10 is fixed / loaded on the surface of the stem 20 via the solder 13.

In the submount 10, a metal multilayer film 15 formed on the surface side on which the semiconductor laser chip is mounted.
Are electrically connected to the surface of the stem 20 by a wire 14a made of a conductor. As a result, the p electrode 3 and the surface of the stem 20 are electrically connected via the solder 12, the metal multilayer film 15, and the wire 14a.

On the surface of the stem 20, the pin 11
Are formed. The pin 11 is insulated from other structures on the surface of the stem 20. The pin 11 and the n-electrode 4 are made of a wire 14b made of a conductor.
Are electrically connected by. Pin 11 and stem 20
Are electrically connected to different external connection terminals, respectively, so that the n-electrode 4 of the semiconductor laser chip is
A current can be externally supplied to each of the p-electrode 3 and the p-electrode 3.

FIG. 2 is a schematic sectional view for explaining the structure of a semiconductor laser chip used in the semiconductor laser device shown in FIG. Referring to FIG. 2, the nitride-based semiconductor laminate 2 formed on the GaN substrate 1 is made of GaN.
GaN buffer layer 21, n-GaN contact layer 22, n-AlGaN cladding layer 23, n-
GaN guide layer 24, GaInN multiple quantum well active layer 2
5, p-AlGaN evaporation prevention layer 26, p-GaN guide layer 27, p-AlGaN cladding layer 28, and p-G
It is configured by stacking the aN contact layers 29.

The P-AlGaN cladding layer 28 is provided with a striped ridge portion extending in the cavity direction. That is, the semiconductor laser chip shown in FIG.
It has a so-called ridge stripe structure. A p-GaN contact layer 29 is arranged on this ridge portion. The insulating film 5 is formed on the p-AlGaN cladding layer 28 so as to cover a region other than the region where the p-GaN contact layer 29 is arranged in the ridge portion. And p
The p-electrode 3 is arranged on the -GaN contact layer 29. Further, in the GaN substrate 1, the GaN buffer layer 2
An n electrode 4 is arranged on the surface opposite to the surface on which 1 is arranged.

In the semiconductor laser device shown in FIG. 1, regarding the shape of the semiconductor laser chip installed on the submount 10 as a mount member, the main surface of the semiconductor light emitting laser chip is intentionally made to have a curved surface (warped). Formed). Specifically, the main surface of the semiconductor laser chip is GaN when viewed from the nitride-based semiconductor laminate 2.
It has a curved surface such that the substrate 1 side is convex. The curved surface on the main surface of the semiconductor laser chip is the submount 10
It has a shape that follows the surface shape of the convex-shaped portion 46. The radius of curvature of this curved surface is preferably 0.2 times or more and 10 times or less the width of the semiconductor laser chip. Also,
The radius of curvature of the curved surface is 0.2 of the width of the semiconductor laser chip.
It is more preferable that the ratio is not less than 5 times and not more than 5 times. As a result,
It is possible to extend the life of the semiconductor laser device.

By making the main surface of the semiconductor laser chip after mounting have a curved surface, the defective product rate of the semiconductor laser device can be reduced and the reliability of the semiconductor laser device can be improved.

In the semiconductor laser chip, the curved surface may be arranged in any way with respect to the ridge portion. Further, when the semiconductor laser chip itself is warped as shown in FIG. 1 to form the curved surface, the warping direction may be substantially perpendicular to the extending direction of the ridge portion. The direction may be inclined with respect to the extending direction of the ridge portion or any other direction.
However, as shown in FIG. 1, the warp of the semiconductor laser chip is reduced in the same direction as the extending direction of the ridge portion, while the semiconductor in the direction substantially perpendicular to the extending direction of the ridge portion is formed. It is more preferable to increase the warp of the laser chip (give the warp in the direction perpendicular to the ridge).

In the semiconductor laser device shown in FIG. 1, not only the semiconductor laser chip shown in FIG. 2 but also semiconductor laser chips having other material structures may be used. For example, a nitride-based compound semiconductor may be used in the laminated body 2 of nitride-based semiconductors. For example,
Instead of the p-AlGaN cladding layer 28, p-AlGa
A layer containing InN may be used, and instead of the GaInN multiple quantum well active layer 25, GaInNAs, GaInNP.
You may use the layer containing materials, such as. In addition, p-AlG
A multiple quantum well active layer may be formed in the region where the aN clad layer 28 is formed, and an InGaN crack prevention layer may be inserted and arranged between the n-GaN contact layer 22 and the n-AlGaN clad layer 23. Good.

Further, in the semiconductor laser device shown in FIGS. 1 and 2, the GaN substrate 1 is used as the substrate, but a material other than GaN may be used as the material of this substrate. For example, a conductive substrate made of a material such as AlGaInN, SiC, or Si can be used.
By using such a substrate, a semiconductor laser chip having a double-sided electrode structure as shown in FIG. 2 can be formed. Also in this case, the same effect as that of the semiconductor laser device shown in FIGS. 1 and 2 can be obtained.

Next, a method of manufacturing the semiconductor laser device shown in FIGS. 1 and 2 will be described. First, a large number of semiconductor laser structures as shown in FIG. 2 were formed on the surface of the GaN substrate 1 by appropriately applying the process used in a normal semiconductor element manufacturing method (a large number of semiconductor films are stacked. Obtain a semiconductor laser wafer. The process of manufacturing such a semiconductor laser wafer is a well-known technique that can be carried out by appropriately applying the process used for manufacturing a normal semiconductor device, and therefore a detailed description thereof will not be given here. The p-electrode 3 is made of p-Ga.
It has a laminated structure of three layers of palladium (Pd) / molybdenum (Mo) / gold (Au) from the N contact layer 29 side. Here, the thickness of palladium can be 10 nm, the thickness of molybdenum can be 15 nm, and the thickness of gold can be 150 nm. Further, the thickness of the GaN substrate 1 when forming the laminated body 2 of the nitride-based semiconductor can be 350 μm.

After forming the nitride semiconductor laminated body 2 as described above, polishing or etching the back surface of the semiconductor laser wafer (the surface opposite to the surface on which the nitride semiconductor laminated body is formed). The surface layer of the GaN substrate 1 is removed by. In this way, the thickness of the semiconductor laser wafer is reduced to about 40 to 120 μm. And Ga
An n electrode 4 is formed on the back surface of the N substrate 1. As the n-electrode 4, a conductor having a laminated structure of titanium (Ti) / aluminum (Al) / molybdenum (Mo) / gold (Au) from the GaN substrate 1 side can be used. Further, here, the thickness of titanium is 30 nm and the thickness of aluminum is 1 nm.
The thickness of 50 nm, the thickness of molybdenum can be 30 nm, and the thickness of gold can be 150 nm.

Then, the semiconductor laser wafer was cleaved to form a laser end face with a cavity length of 500 μm. Then, the semiconductor laser wafer was divided into semiconductor laser chips by cleavage. The resonator length is 500μ
The length is not limited to m and may be set to different lengths.
A method other than cleavage may be used as a method for forming the laser end surface, and the laser end surface may be formed by etching, for example. As a method for dividing the semiconductor laser wafer into semiconductor laser chips, dicing, laser ablation method, or the like may be used.

Next, the semiconductor laser chip obtained through the above steps was mounted on the submount 10 as a holder by junction down. Specifically, first, as shown in FIG. 3, a submount 10 having a convex portion 46 (see FIG. 1) having a convex curved surface on the surface thereof is prepared. The submount 10 is made of copper (Cu). Figure 3
FIG. 3 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIGS. 1 and 2. Then, the metal multilayer film 15 is formed on the surface of the submount 10 on the side where the convex portion 46 is present and the back surface located on the side opposite to this surface. As the metal multilayer film 15, a two-layer film of nickel (Ni) and gold (Au) can be used.

Then, in the submount 10, the solder 12 was deposited on the metal multilayer film 15 on the surface side where the convex portion 46 was formed. AuSn solder can be used as the solder 12. The thickness of the solder 12 is 1μ
m.

Next, the semiconductor laser chip shown in FIG. 2 is arranged on the solder 12 in the region on the convex portion 46 of the submount 10. At this time, p of the semiconductor laser chip
The electrode 3 is arranged so as to face the submount 10 (the semiconductor laser chip is arranged on the submount 10 with the p-electrode 3 facing downward). Then, the submount 10 is heated to a temperature slightly higher than the melting point of the solder 12. As a result, the solder 12 melts.

With the solder 12 melted, a pressing step of pressing the collet 6 having a concave tip as shown in FIG. 1 against the semiconductor laser chip is performed as shown by the arrow in FIG. As a result, the semiconductor laser chip and the metal multilayer film 15 of the submount 10 are well fitted to the solder 12 while applying a load to the semiconductor laser chip by using the collet 6 as appropriate. At this time, the shape (degree of warpage) of the semiconductor laser chip is determined so as to follow the surface shape of the convex portion 46 of the submount 10. Therefore, the shape of the semiconductor laser chip can be changed by appropriately changing the surface shape of the convex portion 46. Then, the solder 12 is solidified by cooling the submount 10. As a result, the submount 10 and the semiconductor laser chip can be stacked and fixed.

Next, the stem 20 as shown in FIG. 1 is prepared. The sheet-shaped solder 13 is placed on the stem 20. As the solder 13, SnAgCu solder can be used. Then, the stem 20 is heated to a temperature slightly higher than the melting point of the solder 13. As a result, the solder 13 melts. In this state, the bonded body of the semiconductor laser chip and the submount 10 is attached to the submount 10
Are placed on the stem 20 so that they face the stem 20 (with the submount 10 facing downward). Then, by appropriately applying a load to the submount 10, the submount 10 and the stem 20 are well fitted to the solder 13. Then, by cooling the stem 20, the solder 13 is solidified.

After that, the pins 11 are set on the surface of the stem 20, and then the wires 14a and 14b are arranged as shown in FIG.
A semiconductor laser device as shown in can be obtained.

In the step of joining the semiconductor laser chip and the submount 10 described above, the submount 1
Although the solder 12 is arranged in advance on the 0 side, the solder 12 may be arranged in advance on the semiconductor laser chip side. Further, in the step of joining the joined body of the semiconductor laser chip and the submount 10 and the stem 20, the sheet-like solder was mounted on the stem 20, but the solder 13 is arranged in advance on the submount 10 side. You may stay.

Further, in the above-mentioned semiconductor laser device, the semiconductor laser chip is die-bonded to the submount 10 by junction down. Therefore, if the thickness of the solder 12 is unnecessarily large, a short circuit occurs between the pn of the semiconductor laser chip. Easier to do. On the other hand, if the thickness of the solder 12 is too thin, the semiconductor laser chip and the submount 10 cannot be bonded with sufficient strength. for that reason,
The thickness of the solder 12 is preferably in the range of 0.5 μm to 5 μm. Further, more preferably, in order to more reliably prevent a short circuit between pns in the semiconductor laser chip, the thickness of the solder 12 is preferably made smaller than the thickness of the nitride-based semiconductor laminate 2 in the semiconductor laser chip. In this case, the thickness of the solder 12 is 0.5 to 2 μ.
It is preferable that the numerical value range is m.

As for the shape of the concave portion of the tip portion which is the pressing portion of the collet 6, this concave shape is used.
It is more preferable to use a concave curved surface corresponding to the curvature of the curved surface of the convex shaped portion 46 of 0. In this case, the curved semiconductor laser chip can be more stably fixed to the curved surface of the submount 10 than in the case where the pressing surface of the collet 6 is flat as shown in FIG.

The size of the tip of the collet 6 may be substantially the same as the size of the semiconductor laser chip. In this case, by pressing the semiconductor laser chip once with the collet 6, a load can be applied to the entire surface of the semiconductor laser chip. Further, in this case, it becomes possible to apply a uniform force to the entire semiconductor laser chip. Therefore, it is possible to improve the work efficiency when the semiconductor laser chip is bonded to the submount 10, and to improve the reliability when the semiconductor laser chip is fixed to the submount 10.

When the size of the tip of the collet 6 is smaller than the size of the semiconductor laser chip, the semiconductor laser chip is pressed by the collet 6 a plurality of times.
The semiconductor laser chip is mounted on the convex portion 46 of the submount 10.
Can be fixed on the surface of. In this case, the surface where the collet 6 contacts is opposite to the surface where the ridge portion is formed in the semiconductor laser chip, but it is located on this ridge portion in order to avoid applying extra stress to this ridge portion. It becomes possible to press the collet 6 against the semiconductor laser chip while avoiding the region. Further, in this case, if a groove is provided in a portion corresponding to the ridge portion on the pressing surface of the collet 6, the collet 6 is mounted on the semiconductor laser chip so that the groove is arranged in the region located on the ridge portion. You can press. As a result, it is possible to prevent excessive stress from being applied to the ridge portion.

Although copper (Cu) is used as the material of the submount 10 described above, a material other than copper may be used as the material of the submount 10. For example, as the material of the submount 10, aluminum (Al), iron (Fe), silver (Ag), alumina, GaAs, Kovar, silicon (Si), molybdenum (Mo), tungsten (W), CuW alloy, GaN, AlN, BeO, S
You may use iC, boron nitride (BN), CuMo alloy, diamond, etc.

The curvature of the surface (pressing surface) of the pressing portion of the collet described above is determined by the convex shape portion 46 of the submount 10.
It is preferable to adapt it to the curvature of the surface or the curvature of the target semiconductor laser chip in the final form.

The shape of the surface of the submount 10 on which the semiconductor laser chips are laminated is as shown in FIGS.
The shape is not limited to the shape shown in (1), and any shape may be used as long as the semiconductor laser chip is curved in a convex direction toward the substrate. More preferably, it is bent in a direction perpendicular to the resonator.

Further, as the stem 20, a metal having copper or iron as a main body can be used as a base, and a metal film can be plated on the surface of the base. As the metal film formed by plating, a laminated film of a nickel (Ni) film and a gold (Au) film can be used.

SnAgC is used as the material of the solder 13.
Although u solder is used, solder made of another material may be used as the solder 13. For example, In system, Sn
It is possible to use solders of the types such as system, Au system, and Pb system. Further, the solder 13 preferably has a lower melting point than the solder 12. In this way, the stem 20
It is possible to prevent the solder 12 from being adversely affected when the submount 10 is mounted thereon. Further, as a method of forming the solder 13, a vapor deposition method, a coating method, a sputtering method,
A printing method or a plating method may be used.

Although AuSn solder is used as the material of the solder 12, another material may be used as the material of the solder 12. For example, as the solder 12, In-based, S
An n-based, Au-based, or Pb-based solder can be used. Further, as a method of forming the solder 12, a vapor deposition method can be used, but a method other than the vapor deposition method, for example, a coating method, a sputtering method, a printing method, a plating method or the like may be used, or the sheet-shaped solder 12 is used. You may use the method of arrange | positioning on the submount 10.

Further, as the metal multi-layer film 15 formed on the surface of the submount 10, a metal multi-layer film other than the above-mentioned laminated film of nickel and gold may be used. For example, as the metal multilayer film 15, titanium (Ti) / nickel (Ni) /
Three-layer film made of gold (Au), titanium (Ti) / platinum (P
t) / gold (Au) three-layer film, molybdenum (Mo)
/ Two-layer film made of gold (Au), three-layer film made of molybdenum (Mo) / nickel (Ni) / gold (Au), three-layer film made of molybdenum (Mo) / platinum (Pt) / gold (Au) You may use a multilayer film, such as. The material forming the metal multilayer film 15 may be changed to another common-sense material that has good adhesiveness between the material forming the submount 10 and the solders 12 and 13. In addition, the film thickness and the film configuration may be different on the front and back surfaces of the submount.

Also, a multilayer film of palladium (Pd) / molybdenum (Mo) / gold (Au) was used as the above-mentioned p electrode 3, but instead of this palladium (in addition to palladium), cobalt (Co), copper (Cu), silver (Ag), iridium (Ir), scandium (Sc), gold (A
u), chromium (Cr), molybdenum (Mo), lanthanum (La), tungsten (W), aluminum (A
l), thallium (Tl), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (P
r), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), titanium (T
i), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta),
Platinum (Pt), nickel (Ni), and compounds thereof may be used. Further, in the above-mentioned palladium / molybdenum / gold multilayer film, cobalt (Co), copper (Cu), silver (Ag), or iridium is used instead of molybdenum (in addition to molybdenum) or between molybdenum and gold. (Ir), scandium (Sc), gold (Au),
Chromium (Cr), lanthanum (La), tungsten (W), aluminum (Al), thallium (Tl), yttrium (Y), lanthanum (La), cerium (C)
e), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb). N
b), tantalum (Ta), platinum (Pt), nickel (N
i), or these compounds may be used. Also,
Instead of gold (in addition to gold) in the above-mentioned three-layer film, nickel (Ni), silver (Ag), gallium (Ga), indium (In), tin (Sn), lead (Pb), antimony (S).
b), zinc (Zn), silicon (Si), germanium (Ge), aluminum (Al), or a compound thereof may be used. In addition, with respect to the thickness of the constituent material layer of the p-electrode 3, a value other than the above value may be used.

The n-electrode 4 is made of Ti / Al / Mo / A
A multilayer film made of u is used. Instead of titanium (Ti) in this multilayer film (in addition to Ti), cobalt (C
o), copper (Cu), silver (Ag), iridium (Ir),
Scandium (Sc), gold (Au), chromium (Cr),
Molybdenum (Mo), lanthanum (La), tungsten (W), aluminum (Al), thallium (Tl), yttrium (Y), lanthanum (La), cerium (C)
e), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), zirconium (Zr), hafnium (H
f), vanadium (V), niobium (Nb), tantalum (Ta), platinum (Pt), nickel (Ni), palladium (Pd), and these compounds may be used. Further, in place of Al in the above-mentioned multilayer film, gold (Au), nickel (Ni), silver (Ag), gallium (Ga), indium (In), tin (Sn), lead (Pb), antimony (Sb). , Zinc (Zn), silicon (Si), germanium (Ge), or compounds thereof may be used. Further, in the above-mentioned multilayer film, instead of molybdenum (Mo) or between molybdenum and gold (Au), cobalt (Co), copper (Cu), silver (Ag), iridium (Ir), scandium (Sc). ), Gold (Au), chromium (Cr), lanthanum (La), tungsten (W), aluminum (Al), thallium (Tl), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr). ), Neodymium (Nd), Samarium (S
m), europium (Eu), terbium (Tb), titanium (Ti), zirconium (Zr), hafnium (H
f), vanadium (V), niobium (Nb), tantalum (Ta), platinum (Pt), nickel (Ni), or these compounds may be used. Further, in place of gold in the multilayer film, nickel (Ni), silver (Ag), gallium (Ga), indium (In), tin (Sn), lead (Pb), antimony (Sb), zinc (Zn). , Silicon (Si), germanium (Ge), aluminum (A
1), or these compounds may be used. Also,
The film thickness of each of the multilayer films forming the n-electrode 4 can be any film thickness other than the above-mentioned film thickness.

Further, as already described, the shape of the submount 10 is not limited to the shape like the submount in the semiconductor laser device shown in FIG. Any shape may be used as long as it can maintain a curved state (warped state). Therefore, the shape of the submount 10 can be arbitrarily changed as described below.

FIG. 4 is a schematic sectional view showing a first modification of the first embodiment of the semiconductor laser device according to the present invention.
FIG. 5 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIG. 4 and 5, the semiconductor laser device basically has the same structure as the semiconductor laser device shown in FIGS. 1 to 3, but the shape of submount 10 is different. That is, the projection is formed on the surface of the submount 10 on which the semiconductor laser chips are stacked. The cross-sectional shape of this protrusion is quadrangular. Even in this case, the semiconductor laser chip can be easily held in a state of being bent in a direction perpendicular to the resonator (direction substantially perpendicular to the direction in which the ridge portion of the semiconductor laser chip extends). As a result,
It is possible to obtain the same effect as that of the semiconductor laser device shown in FIG.

FIG. 6 is a schematic sectional view showing a second modification of the first embodiment of the semiconductor laser device according to the present invention.
FIG. 6 corresponds to FIG. 7 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIG. A second modification of the first embodiment of the semiconductor laser device according to the present invention will be described with reference to FIGS. 6 and 7.

Referring to FIGS. 6 and 7, the semiconductor laser device basically has the same structure as the semiconductor laser device shown in FIGS. 1 to 3, but the shape of submount 10 is different. In the submount 10, a projection having a triangular cross section is formed on the surface on which the semiconductor laser chip is mounted. Even in this case, the same effect as that of the semiconductor laser device shown in FIGS. 1 to 3 can be obtained.

(Second Embodiment) FIG. 8 is a schematic sectional view showing a second embodiment of the semiconductor laser device according to the present invention. FIG. 9 is a schematic sectional view of a semiconductor laser chip used in the semiconductor laser device shown in FIG. Figure 8
A second embodiment of the semiconductor laser device according to the present invention will be described with reference to FIGS.

Referring to FIG. 8, the semiconductor laser device includes a sapphire substrate 31, a nitride-based semiconductor laminate 2 formed on the sapphire substrate 31, and a nitride-based semiconductor laminate 2. The p-electrode 3 and the n-electrode 4 are provided on the surface opposite to the surface facing the sapphire substrate 31. The sapphire substrate 31, the nitride-based semiconductor laminate 2, the p-electrode 3 and the n-electrode 4 form a semiconductor laser chip. The semiconductor laser chip is
Similar to the semiconductor laser chip of the semiconductor laser device according to the first embodiment of the present invention, it is in a warped state along the surface of the convex portion 46 of the submount 10. Details of this semiconductor laser chip will be described later.

As can be seen from FIG. 8, the semiconductor laser device includes a submount 10 having the same shape as the submount used in the semiconductor laser device according to the first embodiment of the present invention. On the surface of this submount 10, metal multilayer films 15a and 15b are formed as in the first embodiment of the semiconductor laser device according to the present invention. However, in the region of the submount 10 located on the convex portion 46 having a curved surface, the metal multilayer films 15a and 15b are formed.
Is not present, and a region where the surface of the convex portion 46 of the submount 10 is exposed is formed. This submount 1
With the region where 0 is exposed as a boundary, the metal multilayer films 15a, 15
b is separated.

Solders 12a and 12b are arranged on the surfaces of the metal multilayer films 15a and 15b, respectively. A semiconductor laser chip is arranged on the solders 12a and 12b with the p-electrode 3 and the n-electrode 4 facing downward (the p-electrode 3 and the n-electrode 4 are arranged in a region facing the submount 10). Then, the p-electrode 3 and the n-electrode 4 and the solders 12a and 12b are fixed to each other, whereby the semiconductor laser chip is fixed and laminated on the submount 10. Further, in the submount 10, the metal multilayer film 15 is formed on the surface opposite to the surface on which the semiconductor laser chips are mounted, as described above. The metal multilayer film 15 and the solder 1
The stem 20 is fixed via 3.

The metal multilayer film 15a is electrically connected to the surface of the stem 20 by a wire 14a made of a conductor. As a result, the p electrode 3 and the surface of the stem 20 are electrically connected via the solder 12a, the metal multilayer film 15a, and the wire 14a.

The pin 11 is arranged on the surface of the stem 20. The pin 11 and the metal multilayer film 15b are electrically connected by a wire 14b made of a conductor. As a result, the n-electrode 4 and the pin 11 are connected to the solder 12
b, the metal multilayer film 15b and the wire 14b are electrically connected. With such a semiconductor laser device, the same effect as that of the semiconductor laser device according to the first embodiment of the present invention can be obtained.

Although the pin 11 is installed on the surface of the stem 20, it is insulated from the surroundings. Therefore, by electrically connecting the stem 20 and the pin 11 to different external connection terminals, the p-electrode 3
It is also possible to externally supply a current as a separate system to the n-electrode 4.

Referring to FIG. 9, the semiconductor laser chip is
It includes a sapphire substrate 31, a nitride-based semiconductor laminate 2 disposed on the sapphire substrate 31, a p-electrode 3 and an n-electrode 4. On one surface of the sapphire substrate 31, a GaN buffer layer 32, an n-GaN contact layer 33, an n-AlGaN multiple quantum well cladding layer 34, an n-GaN guide layer 35, in order from the sapphire substrate 31 side.
GaInN multiple quantum well active layer 36, p-AlGaN evaporation prevention layer 37, p-GaN guide layer 38, p-AlGa
The N multiple quantum well cladding layer 39 and the p-GaN contact layer 40 are stacked.

P-AlGaN multiple quantum well cladding layer 3
9 is provided with a stripe-shaped ridge portion extending in the resonator direction. A p-GaN contact layer 40 is arranged on this ridge portion. The insulating film 5 is arranged on the p-AlGaN multiple quantum well cladding layer 39 so as to cover the region other than the ridge portion. An opening is formed in this insulating film, and the p-GaN contact layer 40 is exposed from this opening. Then, the p electrode 3 is formed on the insulating film 5 and the p-GaN contact layer 40.

In the semiconductor laser chip, p-Al is used.
A groove 41 reaching the n-GaN contact layer 33 from the GaN multiple quantum well cladding layer 39 is formed.
At the bottom of the groove 41, the n electrode 4 is formed so as to contact the n-GaN contact layer 33 and extend onto the insulating film 5 outside the groove 41.

As described above, the semiconductor laser chip shown in FIG. 9 has a so-called ridge stripe type structure. Further, by forming the groove 41, the n-electrode 4 becomes
It is formed on the same side as the p-electrode 3 and is electrically connected to the n-GaN contact layer 33.

Materials other than the above-mentioned materials may be used as the material forming the semiconductor laser chip shown in FIG. For example, a nitride compound semiconductor may be used as a constituent material. Specifically, for example, p-AlGa
Instead of the N multiple quantum well cladding layer 39, p-AlGa
A layer containing InN may be formed, and GaInNAs or G may be used instead of the GaInN multiple quantum well active layer 36.
A layer containing aInNP or the like may be used. Also, p-A
A single clad layer may be used as the lGaN multi-quantum well clad layer 39, and I may be provided between the n-GaN contact layer 33 and the n-AlGaN multi-quantum well clad layer 34.
An nGaN crack prevention layer may be inserted and arranged.

Further, in the semiconductor laser device shown in FIGS. 8 and 9, the sapphire substrate 31 is used.
A material other than sapphire may be used as the material of the substrate. For example, the substrate material is AlGaInN, Si
C, Si, ZnO or the like can be used. As a material used for this substrate, regardless of whether it is a conductor or an insulator, any substrate that allows epitaxial growth of a nitride-based compound semiconductor layer may be used.

Next, a method of manufacturing the semiconductor laser device shown in FIGS. 8 and 9 will be described. First, the sapphire substrate 31
To prepare. By appropriately applying the process used in the manufacturing process of the conventional semiconductor device on the surface of the sapphire substrate 31, a large number of semiconductor laser structures as shown in FIG. 9 are formed (nitride-based semiconductor laminate 2). A semiconductor laser wafer (on which the layers to be formed are formed) is obtained.
Since the process of obtaining this semiconductor laser wafer is a well-known technique, its detailed description will not be given.

Next, after forming the groove 41 on the layer to be the nitride-based semiconductor laminate 2, the p-electrode 3 is formed. p
As a material forming the electrode 3, a two-layer film made of nickel (Ni) / gold (Au) from the side closer to the p-GaN contact layer 40 is used. The Ni layer had a thickness of 10 nm, and the Au layer had a thickness of 200 nm.

On the same surface as the surface on which the p electrode 3 is formed, the n electrode 4 is formed so as to extend from the inside of the groove 41 to the outside of the groove 41. As the n-electrode, n-G
From the side close to the aN contact layer 33, Hf / Al / Mo /
A metal multi-layered film composed of four layers of Au is used. Here, the Hf layer has a thickness of 30 nm, and the Al layer has a thickness of 150 n.
m, the Mo layer has a thickness of 30 nm, and the Au layer has a thickness of 150 n.
m.

When crystal growth is carried out to form the semiconductor layers forming the above-mentioned nitride-based semiconductor laminate 2, the sapphire substrate 31 has a thickness of 350 μm. Then, after the nitride-based semiconductor laminate 2 and the p-electrode 3 and the n-electrode 4 are formed, a surface of the sapphire substrate 31 opposite to the surface on which the nitride-based semiconductor laminate 2 is formed. The (back surface) is partially removed by polishing or etching. As a result, the thickness of the semiconductor laser wafer is reduced to about 40 to 120 μm. After that, the resonator length is set to 300 by cleaving the semiconductor laser wafer.
A laser end face having a thickness of μm is formed. Then, the semiconductor laser wafer was cleaved to be divided into semiconductor laser chips.

The resonator length is not limited to 300 μm,
Other lengths may be used. Further, etching may be used as a method for forming the laser end face. Further, as a method for forming the semiconductor laser chip, a method other than cleavage such as dicing or laser ablation may be used.

In this way, a semiconductor laser chip as shown in FIG. 9 can be obtained. Next, the semiconductor laser chip was mounted on the submount 10, which is a holding body, using a die bonding method. Specifically, the following steps were carried out.

First, a submount 10 having the same shape as that of the first embodiment of the semiconductor laser device according to the present invention is prepared. The sub-mount 10 has a convex portion 46 having a curved surface. This submount 1
The metal multilayer films 15a, 15b, 15 are formed on the surface of 0 (the surface) where the convex portion 46 is formed and the surface (the back surface) opposite to the side where the convex portion 46 is located. Then, solders 12a and 12b made of AuSn solder are deposited on the metal multilayer films 15a and 15b, respectively.

The thicknesses of the solders 12a and 12b are the same as those of the semiconductor laser device according to the first embodiment of the present invention.
The thickness may be approximately the same as the thickness. Also, the solder 12a, 1
As a material forming 2b, a material other than AuSn solder, which is the same as that shown in the first embodiment of the semiconductor laser device according to the present invention, may be used.

In the semiconductor laser device shown in FIG. 8, SiC is used as the material for the submount 10.
To use. The material of the submount 10 is S
Materials other than iC may be used. For example, as the material of the submount 10, alumina, GaAs, Kovar,
Materials such as GaN, AlN, BeO, BN and diamond can be used. Further, another insulator may be used as the material of the submount 10. Further, as the shape of submount 10, as shown in the first embodiment of the semiconductor laser device according to the present invention, for example, a submount having a shape as shown in FIGS. 5 and 7 may be used.

Further, as the material constituting the submount 10, Cu, Al, Fe, Ag, Mo, W, AlSiC
Conductive material such as uW alloy, GaAs, Si, Ga
A semiconductor material such as N or InP may be used. In this case, a structure may be adopted such that an insulator is arranged between the p electrode 3 and the n electrode 4 so that the p electrode 3 and the n electrode 4 are not short-circuited. As a result, the same effect as that of the submount 10 made of an insulator as described above can be obtained.

Next, the above-mentioned semiconductor laser chip is placed on the submount 10 with the p electrode 3 and the n electrode 4 facing downward (the p electrode 3 and the n electrode 4 are placed on the submount 10).
The semiconductor laser chip is arranged on the submount 10 while being arranged so as to face with the semiconductor laser chip. At this time, the semiconductor laser chip is arranged so that the p electrode 3 and the solder 12a are in contact with each other, while the n electrode 4 and the solder 12b are in contact with each other. Next, the submount 10 is soldered to the solder 12a, 12
Heat to a temperature slightly above the melting point of b.

Then, the collet 7 in which the pressing surface 8 has a concave shape having a curved surface is pressed against the semiconductor laser chip as shown by the arrow. In this way, the semiconductor laser chip and the submount 10 were well fitted to the solders 12a and 12b while applying an appropriate load to the semiconductor laser chip. The cross-sectional shape of the pressing surface 8 of the collet 7 is preferably formed so as to have a curvature similar to the curvature of the final shape of the intended semiconductor laser chip. Further, in the semiconductor laser device shown in FIG. 8, the warped state of the final shape of the semiconductor laser chip is similar to the surface shape of the convex portion 46 of the submount 10 (the curved surface of the main surface of the semiconductor laser chip). Is about the same as the radius of curvature of the surface of the convex portion 46 of the submount 10). Then, the submount 10 was cooled to solidify the solders 12a and 12b. As a result, the submount 10 and the semiconductor laser chip can be fixed and laminated.

At this time, the pressing surface 8 of the collet 7 may have a shape other than the curved shape shown in FIG. For example, like the collet 6 shown in FIG. 1, the pressing surface of the collet 7 may have a linear cross-sectional shape (the pressing surface may be a flat surface). The width of the tip of the collet 7 may be smaller than the width of the semiconductor laser chip. In this case, the semiconductor laser chip can be reliably fixed to the submount 10 by pressing the semiconductor laser chip with the collet 7 a plurality of times. Further, at this time, although stress is applied to the ridge portion even from the back surface side where the ridge portion is not formed, it causes deterioration of the characteristics of the semiconductor laser chip.
By using a collet with a small pressing surface, it is possible to apply stress to the semiconductor laser chip by the collet 7 while avoiding the ridge so that excess stress is not applied to this ridge.

Further, in the collet 7, a groove may be formed on the pressing surface 8 so as to avoid the ridge portion. Even in this case, it is possible to prevent the stress from the collet 7 from being applied to the ridge portion.

Next, a sheet-like PbSn is formed on the stem 20.
Place the solder 13. Then, the bonded body of the above-described submount 10 and the semiconductor laser chip is arranged on the solder 13. At this time, the bonded body of the submount 10 and the semiconductor laser chip is arranged so that the submount 10 faces the stem 20. As a result, the metal multilayer film 15 formed on the bottom surface of the submount 10 and the solder 13 are in contact with each other. After that, the stem 20 is heated to a temperature slightly higher than the melting point of the solder 13. As a result, the solder 13 melts. In this state, by appropriately applying stress, the submount 10 and the stem 20 are soldered to each other.
Familiarize yourself with. Then, by cooling the stem 20, the solder 13 is solidified. After arranging the pin 11 on the surface of the stem 20, the wire 14a for electrically connecting the metal multilayer film 15a and the surface of the stem 20 and the wire 1 for electrically connecting the metal multilayer film 15b and the pin 11 are provided.
4b and 4b, respectively. In this way, the semiconductor laser device shown in FIG. 8 can be obtained.

In the step of joining the semiconductor laser chip and the submount 10 described above, the solders 12a and 12b are arranged on the side of the submount 10, but the solders 12a and 12b are arranged on the side of the semiconductor laser chip. You may perform a joining process. Also in the step of joining the stem 20 and the submount 10, the joining step may be performed by disposing the solder 13 on the metal multilayer film 15 of the submount 10 instead of on the stem 20.

The stem 20 is basically the same as the stem 20 used in the first embodiment of the semiconductor laser device according to the present invention. As the solder 13, as described in the first embodiment of the semiconductor laser device according to the present invention, solder made of a material other than PbSn solder may be used. At this time, as the material forming the solder 13, it is preferable to use a material having a melting point lower than the melting points of the solders 12a and 12b. With this configuration, it is possible to prevent the solders 12a and 12b from being adversely affected when the submount 10 is mounted on the stem 20.

Further, the p-electrode 3 shown in FIGS. 8 and 9 is not limited to the above-mentioned materials, but the materials that can be used for the p-electrode 3 shown in the first embodiment of the semiconductor laser device according to the present invention. Can be used.

As for the n-electrode 4, as described above,
Although a multilayer film of four layers of f / Al / Mo / Au was used, the material shown in the first embodiment of the semiconductor laser device according to the present invention can be used instead of the Hf layer and the Al layer. . Also for the Mo / Au layer, the material shown in the first embodiment of the semiconductor laser device according to the present invention can be used. In addition to the above-mentioned materials, the material shown in the first embodiment of the present invention can be used for p-electrode 3. When the Pd / Mo / Au three-layer film as shown in the first embodiment of the present invention is used as the p electrode 3, the same material as that shown in the first embodiment is used for the Mo / Au layer portion. Can be used.

(Third Embodiment) FIG. 10 is a schematic sectional view showing a third embodiment of the semiconductor laser device according to the present invention. 11 is a schematic perspective view showing a submount used in the semiconductor laser device shown in FIG. Figure 10
A third embodiment of the semiconductor laser device according to the present invention will be described with reference to FIGS. In the third embodiment described below and the fourth to sixth embodiments described later, the semiconductor laser chip is mounted on the submount with the substrate side of the semiconductor laser chip and the surface of the submount facing each other. Therefore, any type of semiconductor laser chip described in the first and second embodiments of the present invention can be similarly mounted on submount 10. That is, the third to sixth embodiments described below can be applied to any type of the semiconductor laser chip described in the first and second embodiments of the present invention. Further, the solders 12, 13 and the stem 20 used in the following third to sixth embodiments are basically the same as the solders 12, 13 and the stem 20 shown in the first and second embodiments of the present invention.

Referring to FIGS. 10 and 11, the semiconductor laser device includes a substrate, a nitride semiconductor laminated body, a semiconductor laser chip 17 including a p-electrode and an n-electrode, a submount 16 and a stem 20. Semiconductor laser chip 1
7 is connected to the groove 43 of the submount 16 by the solder 12. In addition, the submount 16 and the stem 20
Are connected to each other by solder (not shown) as in the first and second embodiments of the present invention.

Submount 16 as mounting member
11 has a cubic shape as shown in FIG. 11, and a groove 43 as a concave portion is formed on the surface thereof. The cross-sectional shape of the groove 43 is a semicircle having a smooth curved surface, as can be seen from FIG. The submount 16 shown in FIGS. 10 and 11 is made of copper.

As described above, since the semiconductor laser chip 17 is arranged in the groove 43 in a warped state, it is possible to obtain the same effect as that of the first and second embodiments of the semiconductor laser device according to the present invention. . Further, the shape (curved shape) of the curved surface of the main surface of the semiconductor laser chip 17 is in a state along the shape of the groove 43. Therefore, by changing the shape of the groove 43, the curved surface shape (degree of warpage) of the semiconductor laser chip 17 can be arbitrarily changed.

Next, a method of manufacturing the semiconductor laser device shown in FIG. 10 will be described. First, the semiconductor laser chip 17 is prepared by using the same method as the method shown in the first or second embodiment of the semiconductor laser device according to the present invention. Next, the submount 16 is prepared. A groove 43 is formed on the surface of the submount 16. The solder 12 is placed inside the groove 43 on the surface of the submount 16.

Then, the semiconductor laser chip 17 is placed in the groove 4 of the submount 16 so that the substrate side of the semiconductor laser chip 17 is arranged at a position facing the submount 16.
Place inside 3. After that, the submount 16 is heated to a temperature slightly higher than the melting point of the solder 12. For example, the heating temperature is about 350 ° C. As a result, the solder 12 melts. In this state, the collet 9 having the pressing surface including the curved surface is pressed against the semiconductor laser chip 17 as indicated by the arrow, whereby the semiconductor laser chip 17 is pressed.
Make the substrate and the solder 12 fit together well. At this time, when the semiconductor laser chip 17 has the structure as shown in FIG. 2, specifically, the n electrode 4 formed on the back surface side of the substrate 1 and the solder 12 are connected. In the case where the semiconductor laser chip 17 has the structure shown in FIG. 9, the back surface of the sapphire substrate 31 (see FIG. 9) (the surface located on the side opposite to the surface on which the GaN buffer layer 32 is formed).
A metal film layer (not shown) is formed in advance, and the metal film layer and the solder 12 are joined.

Here, as the metal film layer formed on the surface of the substrate of the semiconductor laser chip 17 and joined to the solder 12, for example, a metal multi-layer film consisting of four layers of Ti / Al / Mo / Au from the substrate side is used. Using. Here, the thickness of the Ti layer was 30 nm, the thickness of the Al layer was 150 nm, the thickness of the Mo layer was 8 nm, and the thickness of the Au layer was 150 nm. AuSn solder was used as the solder 12. In this case, the Au layer, which is the outermost surface layer (outermost layer) of the metal film layer, is dissolved in the solder 12, and the solder material and A of the metal film layer are dissolved.
An alloy with the u layer will be formed. Then, by cooling the submount 16, the solder 12 is solidified. In this way, the submount 16 and the semiconductor laser chip 17 could be joined by the solder 12. Although the solder 12 is installed in advance on the submount 16 side here, the solder 12 may be installed in advance on the semiconductor laser chip 17 side.

Here, the pressing surface 8 of the collet 9 has a groove 43
The surface is a convex curved surface having a curvature substantially equal to the curvature of the surface. Since the semiconductor laser chip 17 is pressed by using the collet 9 as described above, the semiconductor laser chip 17 is pressed.
Is curved and mounted along the surface of the groove 43 of the submount 16.

Further, it is preferable that the pressing surface 8 of the collet 9 has a shape having a curvature similar to that of the warp of the intended semiconductor laser chip 17. In the semiconductor laser device shown in FIG. 10, the warp of the semiconductor laser chip has a curvature similar to the curvature of the inner peripheral surface of the groove 43 of the submount 16. By using such a collet 9, a semiconductor laser device as shown in FIG. 10 can be manufactured reliably and efficiently. When the width of the pressing surface of the collet 9 is smaller than the width of the semiconductor laser chip 17, the same effect can be obtained by pressing the semiconductor laser chip 17 with the collet 9 multiple times.

Here, the surface of the semiconductor laser chip 17 on which the ridge portion is formed is the surface that comes into contact with the collet. Therefore, if the surface on which the ridge portion is formed is strongly pressed by the collet 9, the ridge portion of the semiconductor laser chip may be damaged. Therefore, as described above, the tip of the collet 9 is attached to the semiconductor laser chip 1.
If the collet 9 is made smaller than 7, and the collet 9 is pressed against the semiconductor laser chip 17 a plurality of times, the collet 9 is pressed against the semiconductor laser chip while avoiding the ridge, thereby preventing damage to the ridge. be able to. Also,
The tip of the collet 9 may be made of a relatively soft resin or the like. Also in this case, damage to the ridge portion can be prevented.

(Fourth Embodiment) FIG. 12 is a schematic sectional view showing a fourth embodiment of the semiconductor laser device according to the present invention. FIG. 13 is a schematic perspective view showing a submount used in the semiconductor laser device shown in FIG. A fourth embodiment of a semiconductor laser device according to the present invention will be described with reference to FIGS.

Referring to FIGS. 12 and 13, the semiconductor laser device basically has the same structure as that of the semiconductor laser device according to the third embodiment of the present invention, but the submount 18 is used.
And the material of the solder 12 are different. Specifically, in the semiconductor laser device shown in FIGS. 12 and 13, SiC is used as the material forming the submount 18. In addition, as can be seen from FIG. 13, the shape of the submount 18 is such that projections 19 are formed on the upper surface of a cubic substrate at intervals so as to extend substantially in parallel. In addition, In is used as the material of the solder 12. Further, the submount 18 and the stem 20 are bonded by soldering as in the third embodiment of the semiconductor laser device according to the present invention.

In the semiconductor laser device shown in FIGS. 12 and 13, since the projection 19 is formed on the surface of the submount 18, the semiconductor laser chip 17 is curved in the state shown in FIG. It can be mounted so that it is convex on the submount side. Therefore, the third embodiment of the semiconductor laser device according to the present invention
It is possible to obtain the same effect as that obtained by.

The method of manufacturing the semiconductor laser device shown in FIG. 12 is basically the same as the method of manufacturing the semiconductor laser device according to the third embodiment of the present invention. However, in FIG.
Since the size (width) of the tip of the collet 9 is sufficiently smaller than the size (width) of the semiconductor laser chip 17, as shown in FIG. Presses the collet 9 against the semiconductor laser chip 17 a plurality of times as indicated by the arrow. At this time, the semiconductor laser chip 17 can be pressed by the collet 9 so as to avoid the ridge portion of the semiconductor laser chip 17. The collet 9 shown in FIG.
Can be applied to the method for manufacturing a semiconductor laser device according to the first to third embodiments of the present invention and the fifth and sixth embodiments of the present invention described later.

(Fifth Embodiment) FIG. 14 is a schematic sectional view showing a fifth embodiment of the semiconductor laser device according to the present invention. FIG. 15 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIG. 14
A fifth embodiment of the semiconductor laser device according to the present invention will be described with reference to FIGS.

Referring to FIGS. 14 and 15, the semiconductor laser device basically has the same structure as the semiconductor laser device shown in FIGS. However, in the semiconductor laser device shown in FIGS. 14 and 15, the material forming the submount 18 is aluminum (Al).
Further, the shape of the groove 44 formed on the surface of the submount 18 is different.

The submount 18 is joined to the stem 20 by solder (not shown) as in the semiconductor laser device shown in FIGS. Then, in the submount 18, a groove 44 is formed on the surface opposite to the surface facing the stem 20. The groove 44 has a tapered portion on its upper portion. The cross-sectional shape of the groove 44 is substantially rectangular. Then, the semiconductor laser chip 17 is bent in the groove 44 by using the solder 12, and is mounted by junction up. As a result, the same effect as in the third embodiment of the semiconductor laser device according to the present invention can be obtained.

In the collet 9 used in the manufacturing process of this semiconductor laser device, the semiconductor laser chip 17 is used.
The size of the pressing surface 8 for pressing the semiconductor laser chip 17
Is smaller than. A recess 42 is formed on the pressing surface 8. The recess 42 has a width that is at least larger than the width of the ridge portion of the semiconductor laser chip 17. In this way, the semiconductor laser chip 17
The collet 9 can be pressed against the semiconductor laser chip 17 in such a manner that the recess 42 is arranged on the ridge portion. Therefore, it is possible to prevent unnecessary stress from being applied to the ridge portion of the semiconductor laser chip 17.

As the shape of the collet 9, it is possible to apply the shape of the collet shown in the first to fourth embodiments of the present invention.

As described above, since the semiconductor laser chip 17 can be mounted on the submount 18 in a curved state (a state in which the substrate side is curved so as to be convex), the life of the semiconductor laser device can be significantly improved as compared with the conventional case. You can
For example, as the defective rate of the life of the semiconductor laser device,
It can be 10% or less excluding the initial failure of the semiconductor laser chip.

The shape of the submount 18 is as follows.
The shape is not limited to that shown in FIG. 15, and another shape may be used. For example, as shown in FIG. 16, the cross-sectional shape of the groove 44 may be trapezoidal. Here, FIG. 16 is a schematic perspective view showing a submount used in a modification of the fifth embodiment of the semiconductor laser device according to the present invention shown in FIGS. 14 and 15.

(Sixth Embodiment) FIG. 17 is a schematic partial perspective view of a sixth embodiment of the semiconductor laser device according to the present invention. In FIG. 17, the semiconductor laser chip 17 is mounted on the submount 18 in a curved state. FIG. 18 is a schematic perspective view of the submount 18 used in the semiconductor laser device shown in FIG. FIG. 17
A sixth embodiment of the semiconductor laser device according to the present invention will be described with reference to FIGS.

17 and 18, the semiconductor laser device basically has the same structure as that of the third embodiment of the semiconductor laser device according to the present invention. That is, the surface of the submount 18 opposite to the surface on which the semiconductor laser chip 17 is mounted is joined to the stem (not shown) by solder (not shown). However, the semiconductor laser device shown in FIGS.
The shape of 8 is different. That is, in the semiconductor laser device shown in FIGS. 17 and 18, the upper surface of the submount 18 is planar, and the plurality of protrusions 45 are arranged on the upper surface. As can be seen from FIGS. 17 and 18, the number of protrusions 45 is four here.

However, if it is possible to mount the semiconductor laser chip 17 in a curved state as shown in FIG.
It is not limited to the forms shown in and. That is, the number of the protruding portions 45 may be 5 or more or 3 or less, and the arrangement of the protruding portions 45 is not the position corresponding to the square corner portion as shown in FIG. 18, but the rectangular corner portion. It may be arranged at a corresponding position, a position corresponding to a parallelogram or a trapezoidal corner part, or a position corresponding to another polygonal corner part.

The method of manufacturing the semiconductor laser device shown in FIGS. 17 and 18 is basically the same as the method of manufacturing the semiconductor laser device according to the third embodiment of the present invention.

In this way, in the semiconductor laser device shown in FIGS. 17 and 18, it is possible to reduce the defective fraction of the life of the semiconductor laser device as compared with the conventional one, and the semiconductor laser device according to the first to fifth embodiments of the present invention. The same effect can be obtained.

The combination of the material of the submount and the shape of the submount is not limited to the combinations shown in the first to sixth embodiments of the semiconductor laser device according to the present invention described above. That is, a material generally known as a heat dissipation material can be applied to the material of the submount.
For example, as the material of the submount, Ag, Cu, Cu
W, BeO, Fe, Al ₂ O ₃ , Si, AlN, SiC,
Materials such as cBN, CuMo, and diamond can be used. Even if such a material is applied, the effect of the present invention can be obtained.

Further, the above-described first to sixth embodiments of the present invention.
In the above, the case where a GaN substrate or a sapphire substrate is used as the substrate for forming the semiconductor laser chip is shown, but the same effect can be obtained by using other substrate materials. For example, SiC or the like may be used as the material of the substrate forming the semiconductor laser chip.

Further, the solder for bonding the semiconductor laser chip and the submount, or the solder for bonding the submount and the stem is the same as in the first embodiment.
It is not limited to the materials shown in FIGS. Examples of these solders having a relatively low melting point include In and I
In such as nPb, InSn, InAg, InAgPb
Alloys containing In (In-based solder), Sn, Sn
Pb, SnSb, SnAg, SnSb, SnAgPb,
Sn-containing alloys such as SnAgCu and SnPbSb (S
It is possible to use an n-based solder) or an epoxy resin or a polyimide resin mixed with a powder of Ag, gold (Au), Cu or the like. Examples of the solder having a high melting point include AuSi, AuSn, AuGa, and A.
uGe, AuSb, AuNi, AuIn, AuAgSn
An alloy containing Au (such as Au-based solder) can be used.

In particular, solder having a low melting point such as In or PbSn can reduce thermal damage to elements such as semiconductor laser chips. On the other hand, AuSn, Sn
By using a solder having a high melting point such as AgCu, the semiconductor laser chip and the submount, or the submount and the stem can be firmly bonded. Further, when SnAgCu is used as the material of the solder, the wettability of the solder is good, and even when a sheet-shaped solder such as a solder foil is used for bonding the semiconductor laser chip, a defect such as a short circuit occurs in the semiconductor laser chip. Can be prevented.

Further, in the above-described first to sixth embodiments, the example in which the semiconductor laser chip is mounted on the submount has been described, but the semiconductor laser chip is directly held by the holder (stem,
The same idea can be applied to mounting on a frame, a package, etc.). That is, when the semiconductor laser chips are directly mounted on these holders, if the semiconductor laser chips are fixed to the holders in a warped state, the same effects as those of the first to sixth embodiments of the present invention described above are obtained. Obtainable. In this case, In, AuSn, PbSn, SnAg are used for adhesion to the semiconductor laser chip holder.
All the solder materials shown in the first to sixth embodiments such as Cu can be used. Further, a metal multi-layer film for improving the adhesiveness may be arranged between the holder and the solder. As the metal multilayer film, a Ni / Au two-layer film,
Ti / Ni / Au trilayer film, Ti / Pt / Au trilayer film, Mo / Au bilayer film, Mo / Ni / Au trilayer film,
A metal multilayer film having a structure such as a Mo / Pt / Au three-layer film can be used.

The collet used in the manufacturing process of the semiconductor laser device shown in the first to sixth embodiments is
It is applicable to the manufacturing process of the semiconductor laser device in each of the other embodiments.

[0165]

Example 1 In order to confirm the effect of the semiconductor laser device according to the first embodiment of the present invention, the following experiment was conducted. That is, as a sample of Example 1 of the present invention, the semiconductor laser device as shown in FIGS. 1 and 2 was prepared. The radius of curvature of the surface of the semiconductor laser chip shown in FIG. 1 was 0.4 mm. Further, in the following examples, the radius of curvature of the surface of the semiconductor laser chip in the semiconductor laser device, which is a sample as an example of the present invention, is the same as that of the semiconductor laser chip of the example of the present invention in Example 1. And

As a sample of Comparative Example 1, a submount 10 having a basically similar structure to that of the semiconductor laser device shown in FIG. 1 but a flat upper surface was used.
A semiconductor laser device in which a semiconductor laser chip was mounted by junction down on the flat upper surface of this submount was manufactured by a method similar to the method described in the first embodiment of the present invention. Further, a submount having a concave portion with a curved surface formed on the upper surface is used, and a semiconductor laser chip is mounted in the concave portion of this submount by a junction down method by the same method as the method shown in the first embodiment of the present invention. A semiconductor laser device which is a sample as Comparative Example 2 was manufactured. In the semiconductor laser device which is the sample of Comparative Example 2, the semiconductor laser chip is in a warped state such that the substrate side is concave.

Example 1, Comparative Example 1, and Comparative Example 2
The semiconductor laser chip used for is a chip manufactured from the same wafer. The threshold current of each semiconductor laser chip before mounting was 40 mA.

Next, the threshold current at room temperature was measured for each of the samples of Example 1 and Comparative Examples 1 and 2. As a result, the semiconductor laser device which is the sample of Example 1 has a threshold current value of 30 mA, and the semiconductor laser device which is the sample of Comparative Example 1 has a threshold current value of 38 mA.
The threshold current value of the semiconductor laser device as the sample of Comparative Example 2 was 35 mA.

Then, the above-mentioned Example 1 and Comparative Example 1,
The aging test was performed on the three samples No. 2 under the conditions of the ambient temperature of 20 ° C. and the output of 5 mW. The determination condition in this aging test is that the value of the drive current is 150 mA when the output of the semiconductor laser device is 5 mW.
The integrated time at the above time point was determined as the life of the semiconductor laser device.

The results of the aging test are shown in FIG. FIG. 19 is a diagram showing a graph showing the relationship between the drive current value and the time of aging test (aging time) for the samples of Example 1 and Comparative Examples 1 and 2.
The horizontal axis of FIG. 19 uses a logarithmic memory.

As can be seen from FIG. 19, the semiconductor laser device of Comparative Example 2 has a life of about 400 hours.
The semiconductor laser device of No. 2 had a life of 2100 hours, while the semiconductor laser device of Example 1 of the present invention outputs 5 outputs even after the aging time of 10,000 hours.
The drive current when it was set to mW was 70 mA or less. That is, it is understood that the semiconductor laser device according to the first embodiment of the present invention has a life of 10,000 hours or more.

The defective rate of the life of the semiconductor laser device after mounting the submount 10 on the stem 20 is the same as that of the semiconductor laser device according to the first embodiment of the present invention except for the initial defective portion of the semiconductor laser chip. 10%
Hereinafter, in the semiconductor laser device of Comparative Example 1, 20%,
In the semiconductor laser device of Comparative Example 2, it was 40%. The defective rate of the life of the semiconductor laser device is defined in the same manner as the defective rate described above. Specifically, when the aging test is performed under the condition that the ambient temperature is 20 ° C. and the output is 5 mW. In the semiconductor laser device, the cumulative time when the drive current becomes 150 mA or more when the output is set to 5 mW is defined as the life of the semiconductor laser device, and this life is the ratio of the chips less than 500 hours. As a result, the semiconductor laser device according to the present invention is
It was found that the product had a sufficiently long life and the defective rate of the life was lower than that of the conventional one, and had high reliability.

Example 2 In order to confirm the effect of the second embodiment of the semiconductor laser device according to the present invention shown in FIGS. 8 and 9, the following experiment was conducted. First, a semiconductor laser device which is a sample as an embodiment of the present invention shown in FIGS. 8 and 9 is prepared.

Then, the sample of Comparative Example 3 is prepared as follows. First, a SiC submount having a flat upper surface is prepared. After depositing AuSn solder on the flat upper surface of the submount, the AuSn solder is deposited.
Embodiment 2 of the present invention in which a semiconductor laser chip is mounted on a solder.
Mounting was carried out by a method similar to the method shown in. As a result, the curved semiconductor laser chip becomes substantially flat along the flat upper surface of the submount. Then, thereafter, the submount was mounted on the stem 20 using the solder 13 in the same manner as in the method shown in the second embodiment of the present invention. In this way, a semiconductor laser device as a sample of Comparative Example 3 was manufactured.

Then, Comparative Example 4 which is another comparative example
The sample is prepared as follows. First, similarly to the submount used in Comparative Example 2 of Example 1, a SiC submount in which a concave portion having a curved surface is formed on the upper surface is prepared. Then, the semiconductor laser chip was mounted in the recess of this submount using AuSn solder. At this time, since the semiconductor laser chip is pressed along the surface of the recess of the submount using the collet, the semiconductor laser chip has a shape warped in the direction opposite to the original warped state. Then, similarly to the sample of Comparative Example 3 described above, the submount was mounted on the stem 20 using the solder 13. In this way, a semiconductor laser device as a sample of Example 4 for comparison with the present invention was manufactured.

The semiconductor laser chips used in the above-mentioned Examples and Comparative Examples 3 and 4 are chips manufactured from the same wafer. The threshold current of the semiconductor laser chip before being mounted on the submount was the same as 50 mA in the semiconductor laser chips used in all the semiconductor laser devices described above.

Next, the threshold current at room temperature was measured for each of the semiconductor laser device samples manufactured as described above. As a result, the value of the threshold current in the semiconductor laser device as the sample of the example was 38 mA. The threshold current value of the semiconductor laser device as the sample of Comparative Example 3 was 55 mA, and the threshold current value of the semiconductor laser device as the sample of Comparative Example 4 was 80 mA.

For each of the above samples, Example 1
Similarly to the above, an aging test was performed under the conditions of an ambient temperature of 20 ° C. and an output of 5 mW. As a result, the semiconductor laser device which is the sample of Comparative Example 4 has a life of 20 hours, and the semiconductor laser device which is the sample of Comparative Example 3 has a life of 7 hours.
It was 00 hours. On the other hand, in the semiconductor laser device which is the sample of the embodiment of the present invention, the drive current was 80 mA or less when the output was 5 mW even after 10,000 hours had passed. That is, it is understood that the life of the semiconductor laser device of the example of the present invention is 10,000 hours or more.

As in the case of Example 1, the defect rate of the life of the semiconductor laser device was calculated for each sample.
As a result, when the calculation was performed excluding the initial defective portion of the semiconductor laser chip, the defective rate of life was 10% or less in the semiconductor laser device which was the sample of the example of the present invention. On the other hand, the failure rate of the semiconductor laser device of Comparative Example 3 was about 20%, and the failure rate of the semiconductor laser device of Comparative Example 4 was about 40%.

Example 3 In order to confirm the effect of the third embodiment of the semiconductor laser chip according to the present invention shown in FIGS. 10 and 11, the following experiment was conducted. First,
As Example 3 of the present invention, a semiconductor laser device as shown in FIG. 10 was prepared. And the sample of the comparative example 5 was prepared as follows. First, a submount made of copper (Cu) having a flat upper surface was prepared. After AuSn solder was vapor-deposited on the flat upper surface of the copper submount, a semiconductor laser chip was junction-up on the flat surface of the AuSn solder as in the method of manufacturing the semiconductor laser device described in the third embodiment of the present invention. Mounted. At this time, since the semiconductor laser chip is pressed by the collet along the surface of the submount, the semiconductor laser chip has a substantially flat shape. Then, this submount was mounted on the stem using solder. In this way, a semiconductor laser device as a sample of Comparative Example 5 was manufactured.

Then, another sample of Comparative Example 6 was prepared as follows. First, a copper submount having a projection (projection) having a curved surface on the upper surface was prepared. Then, AuSn solder was vapor-deposited on the surface of the copper submount on which the protrusions were formed, and then a semiconductor laser chip was mounted by a junction up method. At this time, the semiconductor laser chip is pressed by the collet, so that the semiconductor laser chip is warped in a direction opposite to the direction of the sample of the embodiment, such as along the convex portion on the surface of the submount. Then, the submount is fixed on the stem with solder. In this way, a semiconductor laser device as a sample of Comparative Example 6 was prepared.

The above-mentioned Example 3 and Comparative Examples 5 and 6 were used.
The semiconductor laser chip used for is a chip manufactured from the same wafer. The value of the threshold current of each semiconductor laser chip before mounting on the submount was 40 mA, which was the same.

After the semiconductor laser device sample was prepared as described above, the threshold current was measured at room temperature. As a result, the threshold current value of the semiconductor laser device as the sample of Example 3 was 30 mA. On the other hand, the threshold current value of the semiconductor laser device as the sample of Comparative Example 5 was 38 mA, and the threshold current value of the semiconductor laser device as the sample of Comparative Example 6 was 53 mA.

Then, the above-mentioned Example 3 and Comparative Example 5,
An aging test was performed on each of the samples 6 in the same manner as in Example 1. The conditions for the aging test are:
The ambient temperature is 20 ° C, the output of the semiconductor laser device is 5 mW
And The aging determination conditions are the same as the aging test determination conditions of Examples 1 and 2.

As a result, the life of the semiconductor laser device as the sample of Comparative Example 6 was about 40 hours, and the life of the semiconductor laser device as the sample of Comparative Example 5 was 2100 hours. on the other hand,
The semiconductor laser device which is the sample of the third embodiment of the present invention is 10
Even after 000 hours, the drive current when the output was 5 mW was 70 mA or less. That is, it is understood that the semiconductor laser device of Example 3 of the present invention has a life of 10,000 hours or more.

Further, the defect rate of the life of the semiconductor laser device of Example 3 was 10% or less in the semiconductor laser device of Example 3 except for the initial defect of the semiconductor laser chip. On the other hand, the failure rate of the semiconductor laser device of Comparative Example 5 was 20%, and the failure rate of the semiconductor laser device of Comparative Example 6 was 40%.

Example 4 In order to confirm the effect of the fourth embodiment of the semiconductor laser device according to the present invention shown in FIGS. 12 and 13, the following experiment was conducted. First, Fig. 1
A semiconductor laser device as a sample of Example 4 as shown in 2 was prepared. Then, a semiconductor laser device as a sample of Comparative Example 7 was prepared as follows. First, a SiC submount having a flat upper surface is prepared, and a semiconductor laser chip is joined up on the flat surface of the submount by a method similar to the method for manufacturing the semiconductor laser device according to the fourth embodiment of the present invention. I mounted it at. At this time, the semiconductor laser chip is pressed by the collet to have a substantially flat shape along the surface of the submount. Then, the submount on which this semiconductor laser chip was mounted was mounted on the stem using solder using the same method as the method for manufacturing the semiconductor laser chip of the fourth embodiment of the present invention. Thus, a semiconductor laser device as a sample of Comparative Example 7 was obtained.

A semiconductor laser device as a sample of Comparative Example 8 was prepared as follows. First, a submount made of SiC, in which a convex portion having a curved surface is formed on the upper surface, is prepared. Then, a semiconductor laser chip was mounted in a junction-up manner on the surface of the submount on which the convex portion was formed by using the same method as the method for manufacturing the semiconductor laser device according to the fourth embodiment of the present invention. Note that solder is vapor-deposited on the surface of the submount on which the convex portion is formed. As a result, like the comparative example 6 described in the example 3, the semiconductor laser chip has a shape in which the sample of the example 4 is warped to the side opposite to the semiconductor laser chip. Thereafter, this submount was mounted on the stem using solder by the same method as the method for manufacturing the semiconductor laser device according to the fourth embodiment of the present invention. In this way, a semiconductor laser device as a sample of Comparative Example 8 was manufactured.

The semiconductor laser chips used in the semiconductor laser devices of Example 4 and Comparative Examples 7 and 8 described above are manufactured from the same wafer. The threshold current of each semiconductor laser chip before being mounted on the submount was 50 mA, which was the same value.

Next, the above-described Example 4 and Comparative Examples 7 and 8
The threshold current at room temperature was measured for each of the semiconductor laser devices. The semiconductor laser device of Example 4 has a threshold current value of 38 mA, the semiconductor laser device of Comparative Example 7 has a threshold current value of 55 mA, and the semiconductor laser device of Comparative Example 8 has a threshold current value of 80 mA. Met.

Next, the above-mentioned Example 4 and Comparative Examples 7 and 8
An aging test was performed on each of the semiconductor laser devices in the same manner as in Example 1. As conditions for the aging test, the ambient temperature was 20 ° C. and the output was 5 mW.
Then, the test results were evaluated using the same judgment conditions as in Example 1. As a result, the semiconductor laser device of Comparative Example 8 had a life of about 20 hours and the semiconductor laser device of Comparative Example 7 had a life of 700 hours, while the semiconductor laser device of Example 4 of the present invention had a life of 10,000 hours. Output is 5 even after passing
The drive current value at mW was 80 mA or less. Therefore, the life of the semiconductor laser device according to the fourth embodiment of the present invention is 10
It turns out that it is more than 000 hours.

In addition, the above-described Example 4 and Comparative Examples 7 and 8
The defect rate of the lifetime of the semiconductor laser device is 10% or less for the semiconductor laser device of Example 4 of the present invention, except for the initial defect of the semiconductor laser chip, while the comparative example 7
The semiconductor laser device had a life defect rate of 20%, and the semiconductor laser device of Comparative Example 8 had a life defect rate of 40%.

An aging test was similarly performed on the semiconductor laser devices of the fifth and sixth embodiments of the present invention. As a result, the defect rate of the life of each semiconductor laser device is 1 except the initial defect of the semiconductor laser chip.
It was 0% or less.

The embodiments and examples disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiments and examples but by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.

[0195]

As described above, according to the present invention, since the semiconductor laser device is constructed in the state where the main surface of the semiconductor laser chip has a curved surface, the semiconductor laser device can have a long life and its reliability is improved. Can be made.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a semiconductor laser device according to the present invention.

FIG. 2 is a schematic cross-sectional view for explaining the structure of a semiconductor laser chip used in the semiconductor laser device shown in FIG.

3 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIGS. 1 and 2. FIG.

FIG. 4 is a schematic sectional view showing a first modification of the first embodiment of the semiconductor laser device according to the present invention.

5 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIG.

FIG. 6 is a schematic cross-sectional view showing a second modification of the first embodiment of the semiconductor laser device according to the present invention.

7 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIG.

FIG. 8 is a schematic sectional view showing a second embodiment of the semiconductor laser device according to the present invention.

9 is a schematic sectional view of a semiconductor laser chip used in the semiconductor laser device shown in FIG.

FIG. 10 is a schematic sectional view showing a third embodiment of the semiconductor laser device according to the present invention.

11 is a schematic perspective view showing a submount used in the semiconductor laser device shown in FIG.

FIG. 12 is a schematic sectional view showing a fourth embodiment of the semiconductor laser device according to the present invention.

13 is a schematic perspective view showing a submount used in the semiconductor laser device shown in FIG.

FIG. 14 is a schematic sectional view showing a fifth embodiment of the semiconductor laser device according to the present invention.

15 is a schematic perspective view of a submount used in the semiconductor laser device shown in FIG.

FIG. 16 is a schematic perspective view showing a submount used in a modification of the fifth embodiment of the semiconductor laser device according to the present invention shown in FIGS. 14 and 15.

FIG. 17 is a schematic partial perspective view of a semiconductor laser device according to a sixth embodiment of the present invention.

18 is a schematic perspective view of a submount 18 used in the semiconductor laser device shown in FIG.

FIG. 19 is a diagram showing a graph showing the relationship between the drive current value and the time of aging test (aging time) for the samples of Example 1 and Comparative Examples 1 and 2.

FIG. 20 is a schematic sectional view showing a conventional semiconductor laser device.

FIG. 21 is a schematic sectional view showing a conventional semiconductor laser device.

[Explanation of symbols]

1 GaN substrate, 2 laminated body, 3 p electrode, 4 n electrode, 5 insulating film, 6, 7, 9 collet, 8 pressing surface,
10, 16, 18 Submount, 11 pins, 12,
13 solder, 14a, 14b wire, 15, 15
a, 15b metal multilayer film, 17 semiconductor laser chip,
19,45 Protrusions, 20 Stems, 21,32 Ga
N buffer layer, 22, 33 n-GaN contact layer,
23 n-AlGaN cladding layer, 24,35 n-G
aN guide layer, 25,36 GaInN multiple quantum well active layer, 26,37 p-AlGaN evaporation preventing layer, 27,
38 p-GaN guide layer, 28 p-AlGaN cladding layer, 29,40 p-GaN contact layer, 31 sapphire substrate, 34 n-AlGaN multiple quantum well cladding layer, 39 p-AlGaN multiple quantum well cladding layer, 42 recess, 41 , 43, 44 grooves, 46 convex portions.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsuyoshi Kamikawa             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company F-term (reference) 5F041 AA43 CA05 CA14 CA40 CA82                       CA92 DA03 DA29                 5F073 AA13 AA45 AA51 AA77 CA07                       CB02 CB22 EA28 EA29 FA14                       FA22 FA27

Claims (19)

[Claims] 1. A semiconductor light emitting device, comprising: a mount member; and a semiconductor light emitting device chip that is provided on the mount member and contains a nitride-based compound semiconductor, wherein a main surface of the semiconductor light emitting device chip has a curved surface. 2. The semiconductor light emitting device chip includes a substrate, and a functional layer formed on the substrate and having the nitride-based compound semiconductor, wherein a main surface of the semiconductor light emitting device chip is formed from the functional layer. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device has a curved surface that is convex on the substrate side when viewed. 3. The semiconductor light emitting device according to claim 1, wherein the radius of curvature of the curved surface is 0.2 times or more and 5 times or less the width of the semiconductor light emitting element chip. 4. A semiconductor light emitting device comprising: a mount member including a convex portion having a convex surface; and a semiconductor light emitting element chip installed on the convex portion of the mount member. 5. The main surface of the semiconductor light emitting device chip is
The semiconductor light emitting device according to claim 4, wherein the semiconductor light emitting device has a curved surface that follows the surface shape of the convex portion of the mount member. 6. A semiconductor light emitting device comprising: a mount member including a concave portion whose surface is concave; and a semiconductor light emitting element chip installed on the concave portion of the mount member. 7. The main surface of the semiconductor light emitting device chip is
The semiconductor light emitting device according to claim 6, which has a curved surface that follows the surface shape of the concave portion of the mount member. 8. A semiconductor light emitting device comprising: a mount member including a chip mounting portion having a plurality of protrusions formed on a surface thereof; and a semiconductor light emitting element chip installed on the chip mounting portion of the mount member. 9. The main surface of the semiconductor light emitting device chip is
9. The semiconductor light emitting device according to claim 8, wherein the semiconductor light emitting device has a curved surface that is convex toward the mount member side on the chip mounting portion of the mount member. 10. A method for manufacturing a semiconductor light emitting device, comprising: a step of preparing a mount member; and an installation step of installing a semiconductor light emitting element chip on the mount member, wherein a main surface of the semiconductor light emitting element chip has a curved surface. Method. 11. The semiconductor light emitting device chip includes a substrate and a semiconductor functional layer formed on the substrate and having a light emitting function. In the step of preparing the mount member, the surface has a convex shape. Including the step of preparing a mount member including a shaped portion, the installation step, the semiconductor functional layer of the semiconductor light emitting element chip is opposed to the convex portion, the main surface of the semiconductor light emitting element chip is the mount member 11. The method for manufacturing a semiconductor light emitting device according to claim 10, further comprising: disposing the semiconductor light emitting element chip in a state having a curved surface along the surface of the convex shaped portion. 12. The mounting step includes a pressing step of pressing the semiconductor light emitting element chip onto a convex portion of the mount member using a pressing member having a pressing portion whose surface is concave. A method for manufacturing a semiconductor light emitting device as described above. 13. The surface of the concave pressing portion of the pressing member has a curved surface, and the radius of curvature of the curved surface of the pressing member is equal to that of the main surface of the semiconductor light emitting element chip to be installed on the mount member. The method of manufacturing a semiconductor light emitting device according to claim 12, wherein the radius of curvature of the curved surface is substantially equal. 14. The width of the pressing portion of the pressing member is smaller than the width of the semiconductor light emitting element chip, and the pressing step is arranged on the convex portion of the mount member by the pressing portion of the pressing member. The method for manufacturing a semiconductor light emitting device according to claim 12, further comprising pressing the semiconductor light emitting element chip a plurality of times. 15. The semiconductor light emitting device chip includes a substrate and a semiconductor functional layer formed on the substrate and having a light emitting function. In the step of preparing the mount member, the surface has a concave shape. Including a step of preparing a mount member including a shaped portion, the installation step, the substrate of the semiconductor light emitting element chip is opposed to the concave portion, the main surface of the semiconductor light emitting element chip is a concave shape of the mount member The method for manufacturing a semiconductor light emitting device according to claim 10, further comprising installing the semiconductor light emitting element chip in a state of having a curved surface along a surface of a portion. 16. The method according to claim 15, wherein the installing step includes a pressing step of pressing the semiconductor light emitting element chip into a concave portion of the mount member using a pressing member having a pressing portion whose surface is convex. A method for manufacturing a semiconductor light emitting device as described above. 17. The surface of the convex pressing portion of the pressing member has a curved surface, and the radius of curvature of the curved surface of the pressing member is the same as that of the main surface of the semiconductor light emitting element chip to be installed on the mount member. 17. The method for manufacturing a semiconductor light emitting device according to claim 16, wherein the radius of curvature of the curved surface is substantially equal. 18. The method for manufacturing a semiconductor light emitting device according to claim 12, wherein a groove is formed in the pressing portion of the pressing member. 19. The width of the pressing portion of the pressing member is smaller than the width of the semiconductor light emitting element chip, and the pressing step is arranged on the concave portion of the mount member by the pressing portion of the pressing member. The method for manufacturing a semiconductor light emitting device according to claim 16, further comprising pressing the semiconductor light emitting element chip a plurality of times.