JPH1027944A - Photo-semiconductor element and module and their manufacturing methods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the alignment precision between active region and an optical fiber and a photo-semiconductor element by a method wherein a current block layer is formed so as to bury a ridge structure for the formation of alignment marks such as ridge part, etc., in a specific planar shape on the contact layer on the ridge structure and the current block layer. SOLUTION: A ridge structure 17 comprising a lower clad layer 12, an active layer 13, an upper clad layer 14 is formed on a substrate 11. Next, a current block layer 16 is formed so as to bury the ridge structure 17 further forming a contact layer 15. Next, alignment markers 3 made of ridge parts in a specific planar shape or dents are formed. Next a surface electrode 18 and back electrode 19 are formed further forming a semiconductor laser 1. In such a constitution, an optical fiber 4 is fixed in a V trench on a submount 3 for providing a semiconductor laser 1 so as to position the alignment markers 30 on the specific parts of the submount 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device, a method for manufacturing the same, and an optical semiconductor module and a method for manufacturing the same. More particularly, the present invention relates to an optical semiconductor device used for an optical semiconductor module, a method for manufacturing the same, and an optical semiconductor with an optical fiber. The present invention relates to a module and a method for manufacturing the module.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing the structure of a conventional laser module having a semiconductor laser and an optical fiber. In FIG. 5, reference numeral 1 denotes a semiconductor laser, 2 denotes a monitor photodiode, and 3 denotes Si. The submount 4 is an optical fiber, 5 is a bonding wire, 6 is a metal frame, 7 is a ferrule, 9 is a connector locking portion, 8 is a V-groove provided on the submount, and 10 is a package.
In this semiconductor laser, an optical fiber 4 and a semiconductor laser 1 as an optical semiconductor element are positioned and mounted on a submount 3, which is then mounted on a frame 6, wire-bonded, etc., and placed in a package 10. It is intended to be sealed. The semiconductor laser 1 is mounted so that its active region, that is, the light emitting region, is located on the extension of the optical axis of the optical fiber 4.

It is necessary to reduce the cost of optical semiconductor modules used in optical communication transceivers and the like used in ordinary homes. Semiconductor laser 1 as shown in FIG.
In a low-cost laser module in which the semiconductor laser 1 and the optical fiber 4 are modularized, the alignment between the semiconductor laser 1 and the optical fiber 4 is first performed by inserting the optical fiber 4 into the V groove 8 provided on the submount 3 made of Si. Is fixed, and the end of the surface electrode (not shown) or the like provided as a predetermined pattern on the surface of the semiconductor laser 1 is used as an alignment marker. The position on which the semiconductor laser 1 is mounted on the submount 3 is adjusted and positioned so that is located at a predetermined position on the submount 3. The relative positional relationship between a portion of the electrode used as an alignment marker and a portion serving as a light emitting region of the semiconductor laser 1 is determined in advance because the surface electrode is formed using a transfer technique using a mask pattern or the like. I know. Therefore, the position where the alignment marker is arranged in a state where the light emitting region of the semiconductor laser 1 is arranged on the optical axis of the optical fiber 4 is determined in advance, and the semiconductor is arranged so that the alignment marker is located at such a position. By adjusting the position at which the laser is mounted, the semiconductor laser 1 can be positioned and mounted so that its light emitting region is located on the extension of the optical axis of the optical fiber 4.

FIG. 6 is a sectional process view showing a conventional method for manufacturing a semiconductor laser. In the figure, 11 is a substrate, 12 is a lower cladding layer, 13 is an active layer, 14 is an upper cladding layer,
5 is a contact layer, 16 is a current blocking layer, 17 is a ridge structure, 18 is a front electrode, 19 is a back electrode, and 20 is an insulating film.

FIG. 8 is a flow chart showing a conventional method of manufacturing a semiconductor laser, and S1 to S9 show steps in the manufacturing method.

Next, a conventional method for manufacturing a semiconductor laser will be described with reference to FIG. First, as shown in FIG. 6 (a), after a lower cladding layer 12, an active layer 13, and an upper cladding layer 14 are sequentially grown on a wafer-shaped (not shown) substrate 11 (step S1). A stripe-shaped insulating film 20 is formed on the upper cladding layer 14, and is selectively etched to a depth reaching the substrate 11 by using this as a mask to form a ridge structure 17 as shown in FIG. Step S2). Active layer 13 in this ridge structure 17
Becomes an active region (light emitting region) of the laser. Next, the insulating film 2
0 is used as a selective growth mask to form a current block layer 16 so as to bury the ridge structure 17 (step S).
3) After the insulating film 20 is further removed (step S
4), a contact layer 15 is formed on the ridge structure 17 and the current blocking layer 16 as shown in FIG. 6D (step S5), and as shown in FIG.
5, a front surface electrode 18 is formed (Step S7), and a back surface electrode 19 is formed on the back surface side of the substrate 1 (Step S7).
8). Actually, as a surface process performed on the contact layer 15, in addition to the step of forming the surface electrode 18, an insulating film for forming a contact surface between the surface electrode 18 and the contact layer 15 into a predetermined shape is formed. The process includes a process and a process for forming a process mesa. The back surface process performed on the back surface of the substrate 11 further includes a process of polishing the back surface of the substrate 11, but is omitted here. Finally, the device is separated from the wafer (step S9) to obtain a semiconductor laser.

Here, in the conventional method for manufacturing a semiconductor laser, in the ridge forming step shown in step S2, a stripe-shaped insulating film 20 is formed also on a region on the wafer where the semiconductor laser is not to be formed. An insulating film having a predetermined shape is formed by using a step of forming the ridge structure 17 so that the lower portion of the insulating film is not etched during the etching for forming the ridge structure 17 so that the region on the wafer where the elements are not formed is formed. An epi marker (not shown) having a size, shape, and plane orientation recognizable even after subsequent crystal growth.
Is formed. Then, the current blocking layer 16 is formed, the striped insulating film 20 and the insulating film used for forming the epi marker are removed, and the contact layer 18 is formed on the entire surface of the wafer. A surface process alignment marker used as a reference for alignment of a surface process such as a process of forming a subsequent surface electrode by etching on the contact layer 18 on a region where a semiconductor laser is not formed on the wafer in accordance with the epi marker (FIG. (Not shown). The alignment marker for the surface process is formed by forming a contact layer 18 also on the epi marker, making it difficult to recognize the epi marker and making it difficult to use in a subsequent process. Is provided in order to facilitate alignment in the surface process.

[0008]

As described above, in a conventional optical semiconductor device such as a semiconductor laser, an epi marker is formed in a region where no device is formed on a wafer, and the epi marker is aligned. In addition, a surface process alignment marker to be used as a reference for positioning in a subsequent surface process is formed on a contact layer on a region of the wafer where no element is to be formed. However, since the epi marker is formed in the step of forming the ridge structure 17, that is, the step of forming the active region (light emitting region) of the active layer 13, the relative positional relationship between the epi marker and the active region is as designed. And the alignment accuracy of the surface process alignment marker with respect to this epi marker is 2 to 5 μm.
m. Furthermore, the alignment accuracy when forming a surface electrode using this surface process alignment marker is about 2 μm.
m. Therefore, the position of the surface electrode is shifted from the designed position by 4 to 7 μm. As a result, the relative positional relationship between the position of the surface electrode and the active region of the optical semiconductor device is 4 to 7 μm.
μm.

For this reason, in a conventional laser module as shown in FIG. 5, in which positioning is performed using a part of the surface electrode of a conventional semiconductor laser as an alignment marker during mounting, the optical fiber 4 Semiconductor laser 1
And a position shift of 4 to 7 μm occurred between the light emitting regions. Such a displacement between the optical fiber and the light emitting region of the semiconductor laser has caused a variation in coupling efficiency. Therefore, in order to obtain a high-performance laser module with good yield, it is necessary to improve the alignment accuracy between the optical fiber and the light emitting region of the semiconductor laser and reduce the variation in coupling efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an optical semiconductor device provided with an alignment marker having a small relative displacement with respect to an active region, and a method of manufacturing the same. The purpose is to provide.

Another object of the present invention is to solve the above-mentioned problems, and to provide an optical semiconductor module excellent in the accuracy of alignment between an optical fiber and an active region of an optical semiconductor element, and a method of manufacturing the same. The purpose is to provide.

[0012]

An optical semiconductor device according to the present invention comprises a lower cladding layer, an active layer, and an upper cladding layer disposed on a semiconductor substrate, and has at least an upper portion formed in a ridge shape. A semiconductor laminated structure having a structure, a current block layer disposed so as to bury the ridge structure, and a predetermined position relative to the ridge structure on the ridge structure and on the current block layer disposed on the current block layer. A contact layer provided with an alignment marker comprising a raised portion or a concave portion having a predetermined planar shape at a position spaced apart, a surface electrode disposed on the contact layer above the ridge structure, and a back surface of the substrate And a back electrode arranged on the side.

Further, the optical semiconductor device according to the present invention comprises a lower cladding layer, an active layer, and an upper cladding layer disposed on a semiconductor substrate, and at least an upper portion thereof has a ridge structure formed in a ridge shape. A semiconductor laminated structure comprising: an alignment marker formed into a columnar shape having a predetermined planar shape at a predetermined interval with respect to the ridge structure portion;
A current blocking layer arranged so as to embed the ridge structure and the alignment marker;
And a contact layer disposed only on the current block layer, a surface electrode disposed on the contact layer above the ridge structure, and a back electrode disposed on the back side of the substrate. It is.

Further, according to the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: growing a lower cladding layer, an active layer, and an upper cladding layer on a wafer-shaped semiconductor substrate; A stripe-shaped insulating film is formed on the upper cladding layer, and the insulating film is used as a mask to selectively etch from the surface of the upper cladding layer to a predetermined depth. Forming a structure, using the insulating film as a mask, selectively growing a current blocking layer so as to bury the ridge structure, removing the insulating film, and forming a contact on the ridge structure and the current blocking layer. A step of growing a layer, and at a position spaced from the ridge structure on the surface of the contact layer in a region where an element is formed on the semiconductor substrate. A surface formed of a raised portion or a concave portion having a predetermined planar shape is formed on a surface of the contact layer in a region where an element is not formed on the semiconductor substrate while forming an alignment marker including a raised portion or a concave portion having a predetermined planar shape. Forming a process alignment marker; performing positioning using the front surface process alignment marker; and forming a front surface electrode on the contact layer above the ridge structure; and forming a back surface on the back surface side of the semiconductor substrate. The method includes a step of forming an electrode and a step of separating a region of the semiconductor substrate where an element is to be formed from a semiconductor substrate having a wafer shape.

Further, according to a method of manufacturing an optical semiconductor device according to the present invention, there is provided a step of crystal-growing a lower cladding layer, an active layer, and an upper cladding layer on a semiconductor substrate;
Forming a first insulating film having a stripe shape and a second insulating film having a predetermined planar shape disposed at a predetermined distance from the first insulating film; , Second
Is selectively etched from the surface of the upper cladding layer to a predetermined depth using the insulating film as a mask to form a ridge structure below the first insulating film,
Forming an alignment marker below the insulating film, selectively growing a current block layer using the first and second insulating films as masks so as to embed the ridge structure and the alignment marker, Removing only the first insulating film, growing a contact layer on a region except on the second insulating film, and forming a surface electrode on the contact layer above the ridge structure; Forming a back electrode on the back side of the substrate.

Further, the optical semiconductor module according to the present invention comprises a mounting table, an optical fiber positioned and mounted on the mounting table, and the optical fiber positioned and mounted on the mounting table. A semiconductor element, wherein the optical semiconductor element comprises:
The alignment marker is used as a position reference so that a region located in the ridge structure of the active layer or below the ridge structure is disposed on an extension of the optical axis of the optical fiber, and is positioned and mounted. It is to become.

Further, a method of manufacturing an optical semiconductor module according to the present invention includes a step of preparing a mounting table and an optical fiber, positioning and mounting the optical fiber on the mounting table,
The optical semiconductor element is prepared, and the alignment marker is used as a reference for the position, so that the region located in the ridge structure of the active layer or below the ridge structure is arranged on the extension of the optical axis of the optical fiber. Positioning the optical semiconductor element on the mounting table and mounting the optical semiconductor element on the mounting table.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a perspective view (FIG. 1A) showing a structure of a semiconductor laser according to a first embodiment of the present invention, a cross-sectional view taken along line 1b-1b in FIG. FIG. 1C is a diagram showing the structure of a laser module in which a laser and an optical fiber are mounted on a submount (FIG. 1C), where 1 is a semiconductor laser, 3 is a submount made of Si, and 4 is an optical The fiber 8 is a V-groove for positioning the optical fiber 4, and the semiconductor laser 1 is positioned on the submount 3 so that its active region (light emitting region) is arranged on the extension of the optical axis of the optical fiber 4. Are located in
11 is a substrate, 12 is a lower cladding layer, 13 is an active layer, 14
Is an upper cladding layer, 15 is a contact layer, 16 is a current blocking layer, 17 is a ridge structure, 18 is a front electrode, 19 is a back electrode, and 30 is an alignment marker. In the first embodiment, two alignment markers 30 having a circular planar shape are provided at positions symmetrical with respect to the ridge structure 17 near the laser resonator end face, but the number of alignment markers is arbitrary. Also, this alignment marker may have any planar shape as long as it is easily recognizable. Further, the position of this alignment marker is provided at any position as long as it does not affect the laser characteristics. May be.

FIG. 2 is a process chart showing a method for manufacturing a semiconductor laser according to the first embodiment of the present invention.
2 is a sectional view of a portion corresponding to a section taken along line 1b-1b of FIG. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts, and reference numeral 20 denotes an insulating film.

FIG. 7 is a flowchart showing a method for manufacturing a semiconductor laser according to the first embodiment of the present invention.
In the figure, S1 to S9 indicate each step in this manufacturing method.

Next, the manufacturing method will be described with reference to FIGS. First, as shown in FIG. 2 (a), a lower cladding layer 12, an active layer 13, and an upper cladding layer 14 are sequentially grown on a wafer-shaped (not shown) substrate 11 (step S1). Subsequently, a stripe-shaped insulating film 20 is provided on the upper cladding layer 14. At this time, an insulating film (not shown) having a predetermined planar shape is also formed on a region of the wafer other than the region where the semiconductor laser element is to be formed.
Further, as shown in FIG. 2B, using the insulating film 20 and the insulating film having a predetermined planar shape as a mask, wet etching is performed to a depth reaching the lower cladding layer 12 to form a ridge structure 17 below the insulating film 20. At the same time, an epi marker (not shown) is formed below the insulating film having the predetermined planar shape (step S2). As a result, a semiconductor multilayer structure having the ridge structure 17 thereon is obtained. In general, the above-mentioned epimarker is provided at several locations around the wafer.

Next, as shown in FIG. 2C, using the insulating film 20 and the insulating film having a predetermined planar shape as a mask, a current blocking layer 16 is formed so as to bury the ridge structure 17 and the epimarker ( Step S3) After removing all of the insulating film (Step S4), a contact layer 15 is further grown on the wafer (Step S5).

Thereafter, a surface process alignment marker (not shown) having a predetermined planar shape, which is used as a reference for alignment of a surface process such as formation of a surface electrode, is placed on a region other than the region where the semiconductor laser is formed on the wafer. An upper surface, for example, on the periphery of the wafer, is formed by positioning the epi marker and etching the surface of the contact layer 15 to a predetermined depth (step S6). At the same time, by etching the surface of the contact layer 15 at a position where the relative positional relationship with the active layer 13 is known in advance on the region where the element of the semiconductor laser is formed,
An alignment marker 30 having a concave portion having a predetermined planar shape such as a circle is formed (FIG. 2D). Note that an alignment marker including a raised portion may be provided by etching and removing a peripheral portion of a region where the alignment marker 30 is formed. Then, the contact layer 1
A front surface electrode 18 is formed on at least the upper region of the ridge structure 17 on the substrate 5 (step S7), a back surface electrode 19 is formed on the back surface side of the substrate 11 (step S8), and each element of the semiconductor laser is separated from the wafer (step S8). Step S9), FIG.
A semiconductor laser as shown in FIG.

Next, a method of manufacturing a semiconductor laser module using this semiconductor laser will be described. First, Si
An optical fiber 4 is fixed in a V-groove 8 provided on a submount 3 made of a semiconductor laser.
The position on which the semiconductor laser 1 is mounted on the submount 3 is adjusted and positioned so that is located at a predetermined position on the submount 3. The relative positional relationship between the alignment marker 30 and a portion serving as a light emitting region of the semiconductor laser 1, that is, the active layer 13 in the ridge structure 17, is determined in advance because the alignment marker is formed using a transfer technique. I know. Therefore, the position of the alignment marker 30 in a state where the light emitting region of the semiconductor laser 1 is arranged on the optical axis of the optical fiber 4 is determined in advance, and the mounting of the semiconductor laser 1 is performed so that the alignment marker 30 is located at such a position. By adjusting the placement position,
The semiconductor laser 1 can be positioned and mounted so that its light emitting region is located on the extension of the optical axis of the optical fiber 4. For example, this positioning is performed by using the alignment marker 3
The distance in the horizontal direction between the zero and the end of the submount 3 is determined in advance, and the position at which the semiconductor laser 1 is mounted is determined so that the alignment marker 30 is arranged at such a position. In this way, it is possible to obtain a semiconductor laser module in which the semiconductor laser 1 is positioned and mounted so that the light emitting region is arranged on the extension of the optical axis of the optical fiber 4.

Here, in the first embodiment, the semiconductor laser 1 is mounted on the submount 3 by using the alignment markers 30 formed simultaneously in the step of forming the alignment markers for forming electrodes on the wafer shown in step S6. The alignment accuracy of the alignment marker 30 relative to the light emitting region of the semiconductor laser 1 is the same as the alignment accuracy of the surface process alignment marker, that is, 2 to 5 μm. The alignment accuracy for one optical fiber 4 is 2 to 5 μm. On the other hand, in the above-described conventional technology, the position of the semiconductor laser is aligned on the submount by using, as a marker, a surface electrode formed with an alignment accuracy further shifted by 2 μm with respect to the surface process alignment marker. Therefore, the relative displacement between the light emitting region and the surface electrode used as the alignment marker is 4 to 7 μm, and as a result, the alignment accuracy of the semiconductor laser 1 with respect to the optical fiber 4 is 4 to 7 μm. Therefore, in the first embodiment, by performing the alignment using the alignment marker 30, the alignment accuracy between the semiconductor laser and the optical fiber, which was conventionally 4 to 7 μm, can be increased to 2 to 5 μm. As a result, the coupling efficiency between the semiconductor laser and the optical fiber can be improved.

Further, since the alignment marker 30 is formed simultaneously with the step of forming the electrode-forming alignment marker on the wafer in the step of forming the semiconductor laser 1, there is no need to add a new process in the conventional process. As a result, the alignment accuracy between the alignment marker 30 and the light emitting region of the semiconductor laser 1 can be easily improved.

As described above, according to the first embodiment, the alignment marker 30 having a predetermined planar shape is provided at a position on the contact layer 15 at a predetermined distance from the ridge structure 17. In the step of forming a surface process alignment mark on a region where the semiconductor laser 1 is not formed on the wafer, by simultaneously forming the alignment marker 30, the alignment marker 30 can be formed with high positional accuracy. There is an effect that it is possible to provide a semiconductor laser provided with an alignment marker having excellent alignment accuracy with the light emitting region.

Further, since the semiconductor laser 1 is positioned and mounted on the submount 3 on which the optical fiber 4 is positioned and mounted with reference to the position of the alignment marker 30, the semiconductor laser 1 is mounted. It is possible to improve the alignment accuracy between the laser and the optical fiber,
There is an effect that a laser module having excellent coupling efficiency can be obtained with good yield.

Embodiment 2 FIG. 3 is a perspective view (FIG. 3A) showing a structure of a semiconductor laser according to a second embodiment of the present invention.
3B is a sectional view taken along line 3b-3b of the perspective view (FIG. 3B). In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, 50 denotes a semiconductor laser, and 31 denotes an alignment marker. It is.

FIG. 4 is a process chart showing a method for manufacturing a semiconductor laser according to the first embodiment of the present invention.
3B is a sectional view of a portion corresponding to a section taken along line 3b-3b. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts, and reference numeral 21 denotes a marker forming insulating film.

FIG. 9 is a flowchart showing a method of manufacturing a semiconductor laser according to the second embodiment of the present invention.
In the figure, S1 to S9 indicate each step in this manufacturing method.

Next, the manufacturing method will be described with reference to FIGS. First, as shown in FIG. 4A, a lower cladding layer 12, an active layer 13, and an upper cladding layer 14 are sequentially grown on a wafer-like substrate 11 (step S1). Subsequently, a stripe-shaped insulating film 20 is formed on the upper cladding layer 14.
At the same time, marker-forming insulating films 21 having a circular planar shape are provided on both sides of the insulating film 20 and at positions spaced apart from the insulating film 20 by a predetermined distance. further,
As shown in FIG. 4B, the insulating films 20 and 21
Is used as a mask, wet etching is performed to a depth reaching the lower cladding layer 12, and the ridge structure 1 is formed below the insulating film 20.
7, and an alignment marker 31 is formed below the insulating film 21 (step S2). Thereby, the ridge structure 17 and the alignment marker 3
1 is obtained. At this time,
Although not shown, an epi marker is formed on the wafer as in the first embodiment.

Next, as shown in FIG. 4C, the ridge structure 17 is formed using the insulating films 20 and 21 as a mask.
Then, a block layer 16 is formed so as to embed the alignment marker 31 (step S3). Thereafter, a transfer is performed to form a resist (not shown) so as to cover only the insulating film 21, and the resist is used as a mask. Then, only the insulating film 22 is selectively removed (Step S4), and after removing the resist, the contact layer 16 is grown (Step S5). At this time, the growth of the contact layer 16 does not occur on the insulating film 21, and as a result, the alignment marker 31 can be recognized from above the semiconductor laser.

Subsequently, as in the first embodiment, a surface process alignment marker (not shown) used as a reference for alignment of a surface process such as formation of a surface electrode is provided at the peripheral portion of the wafer or the like, and is used as the epi marker. It is formed by positioning and etching the surface of the contact layer 16 to a predetermined depth (step S6). Thereafter, after the insulating film 21 is removed, a surface electrode 18 is formed on a region including the region on the contact layer 15 where the ridge structure 17 is formed (Step S7), and a back surface electrode 19 is formed on the back surface side of the substrate 11. Is formed (step S8), element isolation is performed (step S9), and the semiconductor laser 50 as shown in FIG.
Get. Note that the insulating film 21 may be left without being removed.

In the second embodiment, the alignment marker 31 is formed simultaneously by the same step (step S2) as the step of forming the ridge structure 17, and the alignment of the mask is performed to form the alignment marker 31. And the like need not be performed in separate steps, and the relative positional relationship between the light emitting region of the semiconductor laser 50 and the alignment marker 31 is substantially the same as the designed positional relationship.
In the subsequent process, these relative positional relationships do not change and do not shift.
The relative displacement between the light emitting region 1 and the light emitting region of the semiconductor laser 50 is very small. As a result, there is an effect that a semiconductor laser provided with an alignment marker having a smaller relative displacement with respect to the light emitting region than the semiconductor laser described in the first embodiment can be obtained.

Further, this semiconductor laser 50 is formed as shown in FIG.
When the present invention is applied to a laser module modularized with a semiconductor laser such as the laser module according to the first embodiment described above and the optical fiber 4, the semiconductor laser 50 is positioned on the submount 3 using the alignment marker 31. By mounting the semiconductor laser, the position where the light emitting region is arranged is adjusted with higher precision than when the semiconductor laser described in the first embodiment is used, and positioning between the optical fiber 4 and the light emitting region is easier. And with high accuracy,
There is an effect that a laser module having excellent coupling efficiency can be obtained with good yield.

In the first and second embodiments,
Although the semiconductor laser has been described, the present invention can be applied to other optical semiconductor elements such as a photodiode, and in such a case, the same effects as those of the above embodiment can be obtained.

In the first and second embodiments,
Although the optical semiconductor module in which the optical fiber and the semiconductor laser are modularized has been described, the present invention relates to a laser module in which the semiconductor laser and other members are modularized, and an optical semiconductor element and other elements and members. The present invention can also be applied to an optical semiconductor module formed as a module. In such a case, the same effects as those of the first and second embodiments can be obtained.

[0039]

As described above, according to the optical semiconductor device of the present invention, the optical semiconductor device comprises a lower cladding layer, an active layer, and an upper cladding layer disposed on a semiconductor substrate, and is formed at least in an upper portion into a ridge shape. A semiconductor laminated structure having a ridge structure comprising: a current blocking layer disposed so as to bury the ridge structure; and a ridge structure disposed on the ridge structure and on the current blocking layer. A contact layer provided with an alignment marker composed of a raised portion or a concave portion having a predetermined planar shape at a position separated by a predetermined distance, a surface electrode disposed on the contact layer above the ridge structure, And a back electrode arranged on the back side of the substrate, so that an alignment member for a surface process used in a surface process such as a step of forming a front electrode is provided. In the step of forming the marker in a region other than the region where the optical semiconductor element is formed on the wafer, an alignment marker can be formed on the contact layer of the optical semiconductor element at the same time, and an alignment marker with a small relative displacement from the active region can be formed. This has the effect of providing an optical semiconductor device having the same.

According to the optical semiconductor device of the present invention, the lower cladding layer, the active layer,
A ridge structure formed of an upper cladding layer and formed at least on the top thereof in a ridge shape, and an alignment marker formed in a columnar shape of a predetermined planar shape at a predetermined distance from the ridge structure portion. A stacked semiconductor structure, a current blocking layer disposed so as to embed the ridge structure and the alignment marker, a contact layer disposed only on the ridge structure and the current blocking layer; Since the front electrode disposed on the top of the ridge structure and the back electrode disposed on the back side of the substrate, the alignment marker can be formed simultaneously in the step of forming the ridge structure, There is an effect that it is possible to provide an optical semiconductor device provided with an alignment marker having a small relative displacement with respect to the active region.

According to the method of manufacturing a semiconductor device according to the present invention, the step of crystal-growing the lower cladding layer, the active layer and the upper cladding layer on the wafer-shaped semiconductor substrate and the formation of the semiconductor substrate are performed. A stripe-shaped insulating film is formed on the upper cladding layer in the region, and the insulating film is used as a mask to selectively etch from the surface of the upper cladding layer to a predetermined depth, thereby forming a lower portion of the stripe-shaped insulating film. Forming a ridge structure on the ridge structure, using the insulating film as a mask, selectively growing a current block layer so as to bury the ridge structure, removing the insulating film, and forming the ridge structure on the ridge structure and on the current block layer. Growing a contact layer at a predetermined distance from the ridge structure on the surface of the contact layer in a region where an element is formed on the semiconductor substrate. An alignment marker formed of a raised portion or a concave portion having a predetermined planar shape, and a raised portion or a concave portion having a predetermined planar shape on the surface of the contact layer in a region where the element formation of the semiconductor substrate is not performed. Forming a surface process alignment marker comprising: a positioning process using the surface process alignment marker; and forming a surface electrode on the contact layer above the ridge structure; and a back surface of the semiconductor substrate. Forming a back electrode on the side and a step of separating a region of the semiconductor substrate where an element is to be formed from a wafer-shaped semiconductor substrate, so that a surface used in a surface process such as a step of forming a front electrode is provided. A process alignment marker is formed in a region other than a region where an optical semiconductor element is formed on a wafer. In step, simultaneously on the contact layer of the optical semiconductor element can be formed an alignment marker, there is an effect that can provide an optical semiconductor device having a relative positional deviation is small alignment marker of the active region.

According to the method for manufacturing an optical semiconductor device of the present invention, the lower cladding layer, the active layer,
A step of growing a crystal of the upper cladding layer, a first insulating film having a stripe shape on the upper cladding layer, and a predetermined plane disposed at a predetermined distance from the first insulating film. Forming a second insulating film having a shape, and selectively etching the first and second insulating films from the surface of the upper cladding layer to a predetermined depth using the first and second insulating films as a mask. While forming a ridge structure at the bottom of the film,
Forming an alignment marker below the second insulating film; and selectively growing a current block layer using the first and second insulating films as a mask so as to bury the ridge structure and the alignment marker. Removing the first insulating film only, growing a contact layer on a region except on the second insulating film, and forming a surface electrode on the contact layer above the ridge structure. And a step of forming a back electrode on the back side of the substrate. Thus, in the step of forming the ridge structure, an alignment marker can be formed at the same time, and a relative displacement with respect to the active region can be achieved. Thus, there is an effect that an optical semiconductor element having an alignment marker with a small number can be provided.

Further, according to the optical semiconductor module of the present invention, the mounting table, the optical fiber positioned and mounted on the mounting table, and the optical fiber positioned and mounted on the mounting table described above. The optical semiconductor element, the optical semiconductor element, the alignment marker, so that a region located in the ridge structure of the active layer or below the ridge structure is disposed on the extension of the optical axis of the optical fiber, Because it was used as a reference for the position, it was positioned and placed,
The optical semiconductor element can be positioned using an alignment marker having a small relative displacement with respect to the active region as a reference, and an optical semiconductor module having excellent alignment accuracy between the optical fiber and the active region of the optical semiconductor element can be provided. There are effects that can be provided.

According to the method of manufacturing an optical semiconductor module of the present invention, a mounting table and an optical fiber are prepared.
Positioning the optical fiber on the mounting table and mounting the optical fiber, preparing the optical semiconductor element, using the alignment marker as a position reference, in the ridge structure of the active layer or below the ridge structure. The step of positioning the optical semiconductor element on the mounting table and mounting the optical semiconductor element on the mounting table, so that the located region is disposed on the extension of the optical axis of the optical fiber. The optical semiconductor element can be positioned using an alignment marker with little misalignment as a reference, and an optical semiconductor module having excellent alignment accuracy between the optical fiber and the active region of the optical semiconductor element can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a semiconductor laser and a laser module according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the method for manufacturing the semiconductor laser according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a structure of a semiconductor laser according to a second embodiment of the present invention.

FIG. 4 is a sectional view illustrating a method for manufacturing a semiconductor laser according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing the structure of a conventional laser module.

FIG. 6 is a cross-sectional view showing a conventional method for manufacturing a semiconductor laser.

FIG. 7 is a flowchart showing a method for manufacturing the semiconductor laser according to the first embodiment of the present invention.

FIG. 8 is a flowchart showing a conventional method for manufacturing a semiconductor laser.

FIG. 9 is a flowchart showing a method for manufacturing a semiconductor laser according to a second embodiment of the present invention.

[Explanation of symbols]

1,50 semiconductor laser, 2 monitor photodiode, 3 submount, 4 optical fiber, 5 bonding wire, 6 frame, 7 ferrule, 8 V
Groove, 9 Connector lock, 10 Package, 11 Substrate, 12 Lower cladding layer, 13 Active layer, 14 Upper cladding layer, 15 Contact layer, 16 Current block layer,
17 ridge structure, 18 front electrode, 19 back electrode,
Reference Signs List 20 insulating film, 21 marker forming insulating film, 30, 31
Alignment marker.

Claims (6)

[Claims] 1. A semiconductor laminated structure comprising a lower cladding layer, an active layer, and an upper cladding layer disposed on a semiconductor substrate and having a ridge structure formed in a ridge shape at least at an upper portion thereof. A current block layer disposed so as to be buried, and a ridge having a predetermined planar shape at a predetermined distance from the ridge structure on the ridge structure and on the surface of the ridge structure disposed on the current block layer A contact layer provided with an alignment marker consisting of a concave portion or a concave portion; a front electrode disposed on the contact layer above the ridge structure; and a rear electrode disposed on the rear surface of the substrate. Characteristic optical semiconductor element. 2. A ridge structure formed of a lower cladding layer, an active layer, and an upper cladding layer disposed on a semiconductor substrate, and formed at least in an upper portion thereof with a ridge shape. A semiconductor laminated structure including an alignment marker formed in a columnar shape having a predetermined planar shape at an interval; the ridge structure; a current block layer arranged to embed the alignment marker; And a contact layer disposed only on the current block layer, a front electrode disposed on the contact layer above the ridge structure, and a back electrode disposed on the back side of the substrate. Characteristic optical semiconductor element. 3. A step of crystal-growing a lower cladding layer, an active layer, and an upper cladding layer on a wafer-shaped semiconductor substrate, and forming a stripe-shaped insulating layer on the upper cladding layer in a region where an element is formed on the semiconductor substrate. Forming a film, selectively etching from the surface of the upper cladding layer to a predetermined depth using the insulating film as a mask, and forming a ridge structure below the stripe-shaped insulating film; Selectively growing a current blocking layer so as to bury the ridge structure as a mask; removing the insulating film to grow a contact layer on the ridge structure and the current blocking layer; A ridge or recess having a predetermined planar shape is provided at a predetermined distance from the ridge structure on the surface of the contact layer on a region where an element is to be formed. In addition to forming an alignment marker composed of a concave portion, a surface process alignment marker composed of a raised portion or a concave portion having a predetermined planar shape is formed on the surface of the contact layer on a region of the semiconductor substrate where the element is not formed. A step of performing positioning using the alignment marker for surface processing, forming a surface electrode on the contact layer above the ridge structure, and forming a back electrode on the back side of the semiconductor substrate; Separating the element formation region of the semiconductor substrate from the wafer-shaped semiconductor substrate. 4. A lower cladding layer, an active layer,
A step of growing a crystal of the upper cladding layer; a first insulating film having a stripe shape on the upper cladding layer; and a predetermined plane arranged at a predetermined distance from the first insulating film. Forming a second insulating film having a shape; and selectively etching the first and second insulating films from the surface of the upper cladding layer to a predetermined depth using the first and second insulating films as a mask. Forming a ridge structure below the insulating film and forming an alignment marker below the second insulating film; and using the first and second insulating films as a mask, forming the ridge structure and the alignment marker. A step of selectively growing a current block layer so as to be buried; a step of removing only the first insulating film; a step of growing a contact layer on a region except on the second insulating film; Method for manufacturing an optical semiconductor device characterized by comprising a step of forming a surface electrode on the top of the ridge structure, and forming a back electrode on the back side of the substrate. 5. The optical semiconductor device according to claim 1, wherein the mounting table, an optical fiber positioned and mounted on the mounting table, and the optical semiconductor element positioned and mounted on the mounting table. The optical semiconductor device, based on the alignment marker, such that a region located in the ridge structure of the active layer or below the ridge structure is disposed on an extension of the optical axis of the optical fiber. An optical semiconductor module characterized by being used and positioned and mounted. 6. A step of preparing a mounting table and an optical fiber, positioning and mounting the optical fiber on the mounting table, and preparing the optical semiconductor device according to claim 1 or 2, and performing the alignment. Using the marker as a reference for the position, the optical semiconductor element is placed on the mounting table so that a region located in or under the ridge structure of the active layer is disposed on an extension of the optical axis of the optical fiber. And mounting the optical semiconductor module on the optical semiconductor module.