JPH11112014A - Reflector, optical semiconductor device using the same, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a reflection face from becoming coarse owing to the heat treatment of a Si substrate, by providing a base and the reflection face of a specified face, which has a specified angle against the base and is formed, by etching. SOLUTION: A reflector 3 is provided with a base, based on the Si mono- crystal substrate having the off angle of 9.7 deg. in the direction of <110> of mono-crystal against a (100) face and the reflection face 4 of the 111} face, which has the angle of 45 deg. against the base and which is etched. In a semiconductor device, a light emitting element 2 and the reflector 3 constituted of Si mono- crystal are respectively fixed on the Si substrate 1 where a light receiving element 5 is formed. Light 6 radiated on the surface of the Si substrate 1 in parallel is reflected on the surface of the Si substrate 1 in a vertical direction by the reflection face 4 of the reflector 3, and an optical disk and the like are irradiated with the light. Reflected light from the optical disk and the like is made incident on the light receiving element 5 and it is treated as a light signal.

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 using a reflector, and more particularly to an optical semiconductor device used for optical information processing such as writing and reading on an optical disk.

[0002]

2. Description of the Related Art FIGS. 8A and 8B show IEEE Translation.
s on Components, Packing And Manufacturing Technol
1 is a cross-sectional view and a top view of an optical semiconductor device having a conventional structure shown in ogy Part B. Vol 18.No, 2, May 1995, pp. 245-249. In the figure, 2 denotes a light emitting element (LD), 4 denotes a reflection surface, 5 denotes a light receiving element (PD), 61 denotes a Si substrate, and 66 denotes a groove.
In such an optical semiconductor device, light emitted parallel to the surface of the Si substrate 61 from the light emitting element 2 mounted on the Si substrate 61 is reflected in the vertical direction to the Si substrate 61 by using the reflection surface 4, and the reflected light is reflected. After irradiating an optical disk or the like (not shown), the reflected light is divided by a hologram and detected as an optical signal by the light receiving element 5 formed on the Si substrate 61. Therefore, since the light reflected by the reflection surface 4 needs to be irradiated to the Si substrate 61 accurately and vertically.
Conventionally, S having an off angle of 9.7 ° from the (100) plane
Using the i-substrate, the Si substrate 61 is wet-etched with KOH or the like to form a groove 66, and an angle between one side surface of the groove 66 and the surface of the Si substrate 61 becomes 45 ° (11).
The (111) plane was used as the reflection plane 4 by forming from the 1) plane. Thus, light emitted from the light emitting element 2 mounted on the etching bottom surface formed in parallel with the Si substrate surface is reflected by the reflecting surface 4 in a direction perpendicular to the Si substrate surface.

[0003]

Since the light receiving element 5 is formed on the Si substrate 61 before the groove 66 is formed by etching, in the step of etching the groove 66,
It is necessary to protect the light receiving element 5. However, Si
When a SiO ₂ film having high durability against KOH or the like which is an etching solution of the substrate is used as a protective film, the Si substrate 6
It became impossible to distinguish from the passivation SiO ₂ film on the light receiving element formed in advance on one surface, and it was difficult to selectively remove only the protective film after etching the groove 66. The heat treatment step for forming the light receiving element 5 is usually performed at a high temperature of about 1000 ° C., but by keeping the Si substrate 61 at such a high temperature, crystal defects are segregated, and then the reflection surface 4 formed by etching is formed. However, there is a problem that the crystal defects occur due to the segregated crystal defects. Furthermore, in the photolithography process performed after the formation of the groove 66, there is a problem that the resist applied to the surface of the Si substrate 61 is not flat because the step is formed in the groove 66, and the precision of forming the resist pattern is reduced. . On the other hand, in Japanese Patent Application Laid-Open No. 9-64478, a through hole is provided in an Si substrate, and a laser chip having a large amount of heat is mounted on a submount provided in the through hole and fixed to a heat sink. In addition to improving the heat radiation, the light emitted from the laser chip is not directed to the reflector formed by etching the Si substrate but to a mirror provided separately on the Si substrate in a direction perpendicular to the surface of the Si substrate. The structure of a reflecting optical semiconductor device is described. However, such a structure requires a process of providing a through hole in the Si substrate and providing a submount therein, which complicates the manufacturing process and requires that the laser chip be fixed on the submount with high precision. However, it was not suitable for mass production. Also, in order to provide a through hole in the Si substrate,
A photolithographic process performed by applying a resist on the surface of the Si substrate could not be used.

On the other hand, the present inventors have conducted intensive studies,
It has been found that if the light emitting element has a low output of 10 mW or less and the light emitting element has a characteristic temperature To of 90 K or more even when the light emitting element is directly mounted on the Si substrate, desired light emitting element characteristics can be obtained. By mounting a light emitting element and a reflector formed separately from the Si substrate on the Si substrate,
The light emitted from the light emitting element is emitted to the S substrate without performing the etching process on the Si substrate having the light receiving element as in the conventional structure.
It has been found that an optical semiconductor device that reflects light in the vertical direction can be formed on the i-substrate. Therefore, the present invention solves the above-mentioned problem caused by using a reflector formed in a groove portion obtained by etching a Si substrate, and provides an optical semiconductor device excellent in mass productivity using a reflector formed by etching a Si single crystal. The purpose is to provide.

[0005]

The inventors of the present invention have made intensive studies and have found that a light emitting element and light emitted from the light emitting element are reflected on a Si substrate on which a light receiving element is formed in a direction perpendicular to the Si substrate. It has been found that the above object can be achieved by fabricating an optical semiconductor device by mounting reflectors, respectively, and completed the present invention.

That is, according to the present invention, a {111} formed by etching a bottom surface at an angle of 45 ° with respect to the bottom surface.
This is a reflector made of a Si single crystal having a surface reflecting surface. As described above, by using a reflector formed independently of the Si substrate and having a reflecting surface at 45 ° to the bottom surface, it is not necessary to form the reflecting surface by etching the Si substrate as in the conventional structure. In addition, it is not necessary to protect the light receiving element formed in advance on the Si substrate. Further, since the groove is not formed, the surface of the Si substrate is flat, and the photolithography process can be performed with high accuracy. Further, since both the light emitting element and the reflector are fixed on the flat Si substrate surface, the alignment can be performed relatively easily. Further, by etching the Si single crystal substrate by selecting appropriate etching conditions, the mirror surface state of
The 1 ° plane can be formed as an etched surface having an angle of 45 ° with respect to the bottom surface, and a reflector can be accurately and easily manufactured.

[0007] The reflector may be a reflector having a step surface adjacent to the reflection surface and parallel to the bottom surface. By providing the reflector with the stepped surface, it is possible to fix the light emitting element by performing alignment with the reflector on the stepped surface in advance, and then fix the reflector on the Si substrate. Positioning can be easily performed.

The reflector has a U-shaped upper surface parallel to the bottom surface, the reflection surface formed by etching on an inner side of the upper surface, and two etched side surfaces adjacent to both sides of the reflection surface. The reflector may be provided with: In this manner, by adopting a structure in which the reflection surface has two etching side surfaces adjacent to both sides of the reflection surface, in the reflection surface etching step, a step formed on the reflection surface according to the etching conditions is formed. By generating on the etching side surface adjacent to the reflection surface, there is no such step,
This is because a reflective surface having excellent flatness can be formed.

[0009] The reflector may be a reflector having the reflection surface as one side surface and another etching side surface having an angle of 63 ° with respect to the bottom surface.

The bottom surface of the reflector is preferably a bottom surface having an off angle of 9.7 ° in the <110> direction of the single crystal with respect to the {100} plane. As described above, the reflector is formed by etching using a Si single crystal substrate whose bottom has an off angle of 9.7 ° in the <110> direction of the single crystal with respect to the {100} plane, Since the {111} plane formed preferentially by etching is formed at 45 ° with respect to the bottom surface, the reflector can be easily and accurately formed.

The reflector has an upper surface parallel to the bottom surface, and a ridge line connecting the reflection surface and the upper surface or the bottom surface has a declination of 5 ° from a <110> direction perpendicular to the off direction. Preferably, it is formed within. When the reflector is formed by etching,
Etching is performed by forming a mask along the <110> direction, and the side line of the mask is set to <110 perpendicular to the off direction.
Direction from the <110> direction perpendicular to the off-direction.
By forming it within an angle of ± °, the occurrence of steps formed on the reflection surface in the etching step is suppressed, and a flat reflection surface can be formed.

According to the present invention, there is provided a Si substrate having a semiconductor light receiving element formed on a surface thereof, the reflector according to any one of claims 1 to 3, wherein a bottom surface is fixed on the Si substrate, and a reflection surface of the reflector. A semiconductor light emitting element that irradiates light to the surface of the Si substrate, wherein light emitted from the semiconductor light emitting element in parallel to the surface of the Si substrate is reflected by the reflection surface in a direction perpendicular to the surface of the Si substrate. Optical semiconductor device. In this manner, by fixing the light emitting element and the reflector according to claims 1 to 3 on the Si substrate, the light irradiated in the direction perpendicular to the surface of the Si substrate without etching the Si substrate. A semiconductor device can be manufactured. Further, in the conventional structure, the reflection surface is formed on the Si substrate by etching.
From the 0) plane, it was necessary to use a Si substrate having an off angle of 9.7 ° in the <110> direction of the single crystal, but in the present invention, since a reflector is separately formed, the Si substrate is inexpensive. (100) The substrate can be used, and the cost can be reduced.

Further, according to the present invention, a method for manufacturing a reflector is provided.
Preparing a Si substrate having a bottom surface having an off angle of 9.7 ° in the <110> direction of the single crystal with respect to the {100} plane, and a direction perpendicular to the off direction on the Si substrate. A mask forming step of forming an etching mask along the line, and an etching step of etching the substrate using the etching mask so that the {111} plane is exposed. A method of manufacturing a reflector, characterized in that at least one of the｝ faces is a reflecting face having an angle of 45 ° with respect to the bottom surface of the Si substrate.

In the above manufacturing method, the mask forming step is a step of forming strip-shaped etching masks at predetermined intervals along a direction perpendicular to the off-direction.
The etching step may be a step of etching the Si substrate so as to penetrate the Si substrate. By using such a method, it is possible to accurately form a reflection surface at an angle of 45 ° with respect to the bottom surface only by an etching process, and it is possible to easily mass-produce the reflector.

In the above manufacturing method, the mask forming step is a step of forming strip-shaped etching masks at predetermined intervals along a direction perpendicular to the off-direction.
The etching step is a step of etching the Si substrate halfway so that a step surface for mounting the semiconductor light emitting element remains on the etching bottom surface, and further includes a step of vertically cutting the step surface. May be. By using such a method, it is possible to easily manufacture a reflector having a step surface on which a light emitting element is mounted.

In the above manufacturing method, the mask forming step is a step of forming a lattice-like etching mask along a direction perpendicular to the off-direction, and the etching step includes forming a concave part having a rectangular upper surface. Forming a side surface of the concave portion as a reflective surface, further comprising cutting the Si substrate having the etched concave portion, wherein the reflective surface and the two etched portions adjacent to both sides of the reflective surface, respectively. It may be one that forms a side surface. By using such a method, a step portion formed on the reflection surface is generated on the etching side surface adjacent to the reflection surface, and it is possible to form a reflector having no step and a reflection surface excellent in flatness.

Preferably, the mask forming step according to the manufacturing method of the present invention is a mask forming step of forming a side line of the mask within a declination of 5 ° from a <110> direction perpendicular to the off direction. By using such a mask forming step, the occurrence of a step formed on the reflecting surface in the etching step is suppressed, and a flat reflecting surface can be formed.

Further, according to the present invention, a light-receiving portion is formed by providing a second-conductivity-type region on a first-conductivity-type Si substrate, and an electrode is buried by opening an SiO ₂ film provided on the light-receiving portion. And a step of fixing a semiconductor light emitting element that irradiates light parallel to the surface of the Si substrate on the Si substrate, and before and after the step, the light is applied in a direction perpendicular to the surface of the Si substrate. And fixing the bottom surface of the reflector according to claim 1 or 2 having a reflecting surface to the surface of the Si substrate.

Further, the present invention provides a step of forming a light-receiving portion by providing a second-conductivity-type region on a first-conductivity-type Si substrate, opening an SiO ₂ film provided on the light-receiving portion, and forming an electrode portion. And mounting the semiconductor light emitting element on the stepped surface of the reflector according to claim 2, and further fixing the reflector on the surface of the Si substrate, so that the semiconductor light emitting element is parallel to the stepped surface. The method of manufacturing an optical semiconductor device, wherein the irradiated light is reflected in a direction perpendicular to the surface of the Si substrate by a reflection surface of the reflector.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 shows an optical semiconductor device according to one embodiment of the present invention. FIG. 1A is a cross-sectional view taken along the line II ′, and FIG. 1B is a top view. In the drawing, the same reference numerals as those in FIG. 8 indicate the same or corresponding parts. In such an optical semiconductor device, a light emitting element 2 and a reflector 3 made of a Si single crystal are fixed on a Si substrate 1 on which a light receiving element 5 is formed, and the light emitting element 2 irradiates the Si substrate surface in parallel. The light 6 is reflected by the reflecting surface 4 of the reflector 3 in a direction perpendicular to the surface of the Si substrate, and is applied to an optical disk or the like (not shown). The light reflected from the optical disk or the like is
And is processed as an optical signal. T on the reflecting surface 4
It is preferable to cover with a highly reflective metal such as i / Au.

FIG. 2 shows a reflector 3 according to the first embodiment.
FIG. In the manufacturing process of the reflector according to the first embodiment, first, as shown in FIG. 2A, an Si single crystal substrate 10 is prepared. An off-substrate having an off angle of 9.7 ° with respect to the (100) plane in the <110> direction of the single crystal is used as the Si single crystal substrate 10. Subsequently, as shown in FIG. 2B, an SiO ₂ film 7 is formed on the surface of the substrate by using a thermal oxidation method. Subsequently, FIG.
As shown in FIG. 1, the SiO ₂ film 7 on the substrate surface is etched using a photolithographic process, and the Si single crystal substrate 1 is etched.
A mask for etching 0 is formed. Such a mask is formed on the Si single crystal substrate 10 along the <110> direction perpendicular to the off direction of the substrate, and in particular, the declination within 5 ° from the <110> direction perpendicular to the off direction of the substrate. It is preferable to form it. By forming the deflected angle within 5 °, it is possible to suppress the formation of steps on the etched surface in the step of etching the Si single crystal substrate 10 and to form the etched reflective surface 4 having excellent flatness. is there. Subsequently, as shown in FIG. 2D, after the back surface of the Si single crystal substrate 10 is coated with wax 11 or the like, the Si single crystal substrate 10 penetrates using a KOH solution at about 100 ° C. as an etching solution. The etching of the Si single crystal substrate 10 is performed up to this point. In such an etching step, the {111} plane having a low etching rate is preferentially formed as an etching surface. Therefore, as described above, the Si single crystal substrate 10
By using an off-substrate having an off angle of 9.7 ° in the <110> direction of the single crystal with respect to the (100) plane, the reflection surface to be etched can be exactly 45 ° off the bottom surface of the substrate. It is formed to have an angle. The other side to be etched is 63
It is formed at an angle of °. In FIG. 1, the side surface of the reflector 3 facing the reflection surface is cut in a direction perpendicular to the bottom surface. However, the {111} etched surface as shown in FIG. 2D may be used. . Finally, as shown in FIG. 2 (e), after removing the SiO ₂ film 7, Au and Ti8 are sequentially laminated by vapor deposition to complete the reflector 3. The reflector can be used by appropriately cutting it in a direction parallel to the cross section. As described above, by forming the reflector 3 by etching the Si single crystal substrate 10 having a predetermined off-angle, the reflector 3 having the reflection surface at an angle of 45 ° with respect to the bottom surface can be formed only by the etching process. , And can be formed with high precision. That is, only by selecting the off-angle of the substrate, the accuracy of the etching angle as in the case of forming the reflection surface by mechanical grinding becomes unnecessary, the manufacturing process can be simplified, and the process is suitable for mass production.

FIG. 3 is a sectional view showing a manufacturing process of the optical semiconductor device according to the first embodiment of the present invention. First, FIG.
As shown in FIG. 5, an SiO ₂ film 7 is formed on a p-type Si substrate 1 by using a thermal oxidation method, and an opening is provided at a predetermined position by using a photolithographic process. Next, using a thermal diffusion method, for example, phosphorus is diffused to form an n-type region, and the light receiving element 5 is formed. Subsequently, as shown in FIG. 3B, the entire surface of the Si substrate 1 is again subjected to thermal oxidation to form a SiO ₂ film 7.
Cover with. Subsequently, as shown in FIG. 3C, an opening is provided at a predetermined position of the SiO ₂ film 7 by using a photolithography process, and the electrode 9 of the light receiving element 5 is buried.
Subsequently, as shown in FIG. 3 (d), the pre-made bottom surface of the reflector 3 by the manufacturing process shown in FIG. 2, at a predetermined position on the Si substrate 1, through the SiO ₂ film 7, heat Fix with curable resin. As a result, the reflection surface 4 of the reflector 3 has an angle of 45 ° with respect to the surface of the Si substrate 1. Subsequently, as shown in FIG. 3 (e), the light-emitting element 2, a predetermined position on the Si substrate 1, through the SiO ₂ film 7, Au-
It is fixed using Sn-based solder. In such a structure, the light 6 emitted from the light emitting element 2 is reflected by the reflector 3 in parallel to the surface of the Si substrate 1.
And is reflected by the reflective surface 4 in a direction perpendicular to the surface of the Si substrate 1. In the light emitting element 2,
A light-emitting element having a relatively small amount of heat radiation, that is, a light-emitting element with a low output of 10 mW or less and a light-emitting element with a characteristic temperature To of 90 K or more can be used even if the light-emitting element is directly mounted on a Si substrate. Further, as the light emitting element 2, a light emitting element made of AlGaInAs having an emission wavelength of 630 to 690 nm, a light emitting element made of AlGaAs having an emission wavelength of 750 to 830, or the like can be used. In the above process,
Although the reflector 3 is first fixed on the Si substrate 1 and then the light emitting element 2 is fixed, the above steps can be performed in reverse. Further, the completed optical semiconductor device can be mounted on a package as needed.

As described above, in the optical semiconductor device according to the first embodiment, unlike the conventional structure, the reflection surface 4 is not formed in the groove formed by etching the Si substrate 1, but is separately manufactured. Since the reflector 3 is manufactured by being fixed on the Si substrate 1, it is not necessary to protect the light receiving element 5 at the time of etching the Si substrate 1, which is conventionally required. Also, the Si substrate 1
Since the surface is flat, Si
The surface of the photoresist formed on the surface of the substrate 1 becomes flat, and a highly accurate pattern can be formed. Further, since the reflector 3 is manufactured separately from the Si substrate 1, it is possible to prevent the reflection surface 4 from being roughened due to segregation of crystal defects in a heat treatment process at 1000 ° C. for forming the light receiving element 5. Is also possible.

Embodiment 2 FIG. FIG. 4 shows an optical semiconductor device according to another embodiment of the present invention. FIG.
FIG. 4B is a cross-sectional view taken along line -II ′, and FIG. 4B is a top view. In FIG. In the optical semiconductor device according to the second embodiment, the reflector 3
It has a step, on which the light emitting element 2 is mounted. The surface of the step is parallel to the bottom surface of the reflector 3.

The reflector 3 according to the second embodiment is manufactured by the manufacturing steps (FIG. 2) (a) to (b) according to the first embodiment.
After performing (c), the etching in the step (d) is stopped by stopping the etching bottom surface, and the etching bottom surface is cut in a direction perpendicular to the Si substrate 10. The length of the step is determined by S
It can be adjusted by the interval between the iO ₂ masks 7.

Further, in the manufacture of the optical semiconductor device according to the second embodiment, after performing the manufacturing steps (FIG. 3) (a) to (c) of the optical semiconductor device according to the first embodiment, the reflection A light emitting element 5 is formed on the step of the body 3 by using Au-Sn solder or the like.
Is fixed at a predetermined position on the Si substrate 1,
The fixing is performed with a thermosetting resin via the SiO ₂ film 7.
Therefore, since the position of the reflection surface 4 of the reflector 3 and the position of the light emitting element 5 can be adjusted in advance, the alignment can be easily performed, and the manufacturing process can be simplified.

Embodiment 3 FIG. 5 shows an optical semiconductor device according to another embodiment of the present invention. FIG.
FIG. 5B is a cross-sectional view taken along the line I-III ′, and FIG.
In the figure, the same reference numerals as those in FIG. 8 indicate the same or corresponding parts.
In the optical semiconductor device according to the third embodiment, the reflector 3
Has a U-shaped upper surface 32 parallel to the bottom surface, a reflecting surface 4 joined to the inner side of the upper surface and formed by etching, and two etched side surfaces 31 adjacent to both sides of the reflecting surface. ing.

In the manufacturing process of the reflector 3 according to the third embodiment, first, the manufacturing process according to the first embodiment (FIG. 2)
After performing the steps (a) and (b), as shown in FIG. 6A, a SiO ₂ film 7 mask is formed along one side thereof in the <110> direction perpendicular to the off direction of the substrate. Using the SiO ₂ film 7 as a mask, the Si single crystal substrate 10 is etched into a concave shape having an etched bottom surface. FIG. 6B is a cross-sectional view taken along line XX ′. Subsequently, A and A ′ in FIG.
Then, the reflector 3 is formed by cutting the Si single crystal substrate 10 in a direction perpendicular to the bottom surface of the substrate. FIG. 6 (c) (d)
FIG. 3 is a cross-sectional view taken along the line YY ′ of the reflector 3 and a top view. Like the first embodiment, the mask has a declination of 5 degrees from the <110> direction perpendicular to the off direction of the substrate.
To form the etching reflection surface 4 having excellent flatness is preferable. Since the reflector 3 has two etching side surfaces 31 adjacent to both sides of the reflection surface 4, in the etching process of the reflection surface 4, a step formed on the reflection surface 4 is changed to two adjacent sides on both sides of the reflection surface. By forming the reflective surface 4 on one of the etched side surfaces 31, it is possible to manufacture the reflective surface 4 having no steps and excellent flatness.

The optical semiconductor device according to the third embodiment is manufactured by replacing the reflector 3 with the reflector according to the present embodiment in the manufacturing method according to the first embodiment shown in FIG. be able to.

Embodiment 4 FIG. 7 shows an optical semiconductor device according to another embodiment of the present invention. FIG.
7 (b) is a top view, in which the same reference numerals as those in FIG. 8 denote the same or corresponding parts, and 41 denotes an IC part formed on the surface of the Si substrate 1. Represent.
As described above, in the optical semiconductor device according to the present invention, since the reflective surface 4 is not formed by etching the Si substrate 1 as in the conventional structure, an amplifier circuit, a signal processing circuit, and the like other than the light receiving element 5 are integrated. The formed IC part 41 can be formed on the surface of the Si substrate 1. As a result, high integration and miniaturization of the semiconductor element can be achieved. Note that the present invention is not limited to a light-emitting element having a low output of 10 mW or less and a light-emitting element having a characteristic temperature To of 90 K or more, as long as the light-emitting element emits less heat and has desired light-emitting element characteristics. It is possible to apply.

[0031]

As is clear from the above description, the optical semiconductor device according to the present invention is not formed with a reflection surface in a groove formed by etching a Si substrate as in the conventional structure, but is separately manufactured. The reflector has a structure in which the reflector is fixed on a Si substrate. Therefore, in the manufacturing process of such an optical semiconductor device, it is not necessary to protect the light receiving element at the time of etching the Si substrate, so that the manufacturing process can be reduced and an optical semiconductor device excellent in mass productivity can be provided. Further, since the reflector is manufactured separately from the Si substrate, it is possible to prevent the reflection surface from being roughened due to the heat treatment of the Si substrate.

Also, in the optical semiconductor device according to the present invention,
Since the light emitting element can be fixed on the step portion of the reflector in advance and the reflector can be fixed on the Si substrate, the accuracy of alignment between the reflector and the light emitting element can be improved, and mass productivity can be improved. Can also be improved.

In the optical semiconductor device according to the present invention,
Since the reflection surface is adjacent to the etching side surface, generation of a step on the reflection surface in the reflection surface etching step can be suppressed, and an optical semiconductor device including a reflector having excellent flatness can be manufactured.

[Brief description of the drawings]

FIG. 1A is a sectional view of an optical semiconductor device according to a first embodiment of the present invention; FIG. 2B is a top view of the optical semiconductor device according to the first exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a manufacturing process of the reflector according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a manufacturing process of the optical semiconductor device according to the first embodiment of the present invention;

FIG. 4A is a sectional view of an optical semiconductor device according to a second embodiment of the present invention; FIG. 4B is a top view of the optical semiconductor device according to the second exemplary embodiment of the present invention.

FIG. 5A is a sectional view of an optical semiconductor device according to a third embodiment of the present invention. (B) It is a top view of the optical semiconductor device concerning Embodiment 3 of this invention.

FIG. 6 is a manufacturing process diagram of the reflector according to the third embodiment of the present invention.

FIG. 7A is a sectional view of an optical semiconductor device according to a fourth embodiment of the present invention. (B) It is a top view of the optical semiconductor device concerning Embodiment 4 of this invention.

FIG. 8A is a cross-sectional view of a conventional optical semiconductor device. (B) It is a top view of the conventional optical semiconductor device.

[Explanation of symbols]

Reference Signs List 1 Si substrate, 2 light emitting element, 3 reflector, 4 reflecting surface, 5 light receiving element, 6 light, 7 SiO ₂ film, 8 Ti /
Au, 9 electrode part, 31 etching side surface, 32 upper surface, 41 IC part, 61 Si substrate, 66 groove part.

Claims (14)

[Claims] 1. A reflector made of a Si single crystal having a bottom surface and a {111} reflecting surface etched at an angle of 45 ° with respect to the bottom surface. 2. The method according to claim 1, wherein the reflector is adjacent to the reflection surface,
The reflector according to claim 1, further comprising a step surface parallel to the bottom surface. 3. The reflector has a U-shaped upper surface parallel to the bottom surface, the reflection surface formed by being joined to an inner side of the upper surface, and two reflection surfaces adjacent to both sides of the reflection surface. The reflector according to claim 1, comprising an etched side surface. 4. The reflector according to claim 1, wherein the reflecting surface has one side surface and another etching side surface having an angle of 63 ° with respect to the bottom surface.
3. The reflector according to any one of 3. 5. The reflector according to claim 1, wherein the bottom surface of the reflector has an off angle of 9.7 ° in the <110> direction of the single crystal with respect to the {100} plane. 3. The reflector according to any one of 3. 6. The reflector has an upper surface parallel to the bottom surface, and a ridge line joining the reflection surface and the upper surface or the bottom surface is deviated from a <110> direction perpendicular to the off direction. The reflector according to claim 5, wherein the reflector is formed within 5 degrees. 7. A Si substrate having a semiconductor light receiving element formed on a surface thereof, a reflector according to claim 1, wherein a bottom surface is fixed on the Si substrate, and light is reflected on a reflection surface of the reflector. An optical semiconductor comprising: a semiconductor light emitting element for irradiating light; light emitted from the semiconductor light emitting element in parallel to the surface of the Si substrate; and the light reflected from the reflection surface in a direction perpendicular to the surface of the Si substrate. apparatus. 8. A method of manufacturing a reflector, comprising: preparing a Si substrate having a bottom surface having an off angle of 9.7 ° in a <110> direction of the single crystal with respect to a {100} plane; A mask forming step of forming an etching mask on the Si substrate along a direction perpendicular to the off direction; and an etching step of etching the substrate using the etching mask so that the {111} plane is exposed;
A method of manufacturing a reflector, wherein at least one of the {111} surfaces formed in the etching step is a reflection surface having an angle of 45 ° with respect to the bottom surface of the Si substrate. 9. The mask forming step is a step of forming strip-shaped etching masks at predetermined intervals along a direction perpendicular to the off-direction, wherein the etching step penetrates the Si substrate. 9. The method of manufacturing a reflector according to claim 8, further comprising a step of etching the Si substrate. 10. The mask forming step is a step of forming strip-shaped etching masks at predetermined intervals along a direction perpendicular to the off-direction, wherein the etching step is for mounting a semiconductor light emitting element. 9. The method of manufacturing a reflector according to claim 8, further comprising the step of etching the Si substrate halfway so that the step surface remains on the etching bottom surface, and further comprising a step of vertically cutting the step surface. Method. 11. The mask forming step is a step of forming a lattice-like etching mask along a direction perpendicular to the off-direction. The etching step forms a concave portion having a rectangular upper surface. Forming a side surface of the concave portion as a reflective surface, further comprising a step of cutting the Si substrate having the etched concave portion, forming the reflective surface and two etched side surfaces respectively adjacent to both sides of the reflective surface. The method for manufacturing a reflector according to claim 8, wherein: 12. The mask forming step according to claim 8, wherein the mask forming step forms a side line of the mask within a declination of 5 ° from a <110> direction perpendicular to the off direction. 12. The method for manufacturing a reflector according to any one of items 11 to 12. 13. A light-receiving portion formed by providing a second-conductivity-type region on a first-conductivity-type Si substrate, and forming a SiO2 layer provided on the light-receiving portion.
₍₂₎ a step of opening a film and embedding an electrode portion, and a step of fixing a semiconductor light emitting element for irradiating light parallel to the surface of the Si substrate on the Si substrate; 4. An optical semiconductor, comprising: a step of fixing a bottom surface of the reflector on the Si substrate according to claim 1 or 3, further comprising a reflecting surface that reflects the light in a direction perpendicular to a substrate surface. Device manufacturing method. 14. A light-receiving portion formed by providing a second-conductivity-type region on a first-conductivity-type Si substrate, and forming a SiO2 light-receiving portion on the light-receiving portion.
Forming an opening to the electrode portion ₂ film, by mounting a semiconductor light-emitting element on step surface of the reflector according to claim 2, further securing the reflector on the Si substrate, the A method of manufacturing an optical semiconductor device, wherein light emitted from a semiconductor light emitting element in parallel to the step surface is reflected by a reflecting surface of the reflector in a direction perpendicular to the surface of the Si substrate.