JP2001217500A - Semiconductor device and light pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the intervals of light emission points between semiconductor element small and prevent the influence of heat generated by the heat generating semiconductor laser elements on the other semiconductor layer elements in a semiconductor device which comprises a plurality of such semiconductor laser elements. SOLUTION: A recessed part is formed in a silicon substrate and then a quadrangular mesa-like projection whose slant face consists of a (111) surface, (1-11) surface, (-1-11) surface, and (-111) surface is formed by silicon process. Out of these surfaces, the outer and inner faces of the (111) surface are used as reflection mirrors. The semiconductor laser element are fixed on small projections formed in the recessed part of the silicon substrate and photodetectors are mounted on top faces of the projections to receive return light beams L1', L2' from an optical disc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device and an optical pickup device used for optical information processing, optical measurement, optical communication and the like.

[0002]

2. Description of the Related Art Conventionally, as a semiconductor device in which two light sources are integrated, a hybrid integration in which a red semiconductor laser element and an infrared semiconductor laser element are independently arranged in an optical pickup, a red semiconductor laser structure and a red semiconductor laser structure on the same substrate. Monolithic integration for integrating infrared semiconductor laser structures is known.

[0003] Hereinafter, these two integration examples will be described.

First, an outline of a conventional semiconductor device in which two light sources are monolithically integrated will be described with reference to FIG.

As shown in FIG. 14, in this semiconductor device 1, for example, a DV
A semiconductor laser element 3 for emitting a laser beam L11 having a wavelength of about 650 nm for D, and a wavelength of about 780 nm for CD, for example.
Semiconductor laser element 4 that emits the laser light L12 of the above, and a photodetector 5 having a plurality of sensor elements 5a to 5d
And a micro prism 6 functioning as a reflection mirror are provided in an integrated manner.
A hologram for splitting the 0th-order light, the + 1st-order light, and the -1st-order light of the return light beam from an optical recording medium (not shown) such as an optical disk, for example, to be incident on the sensor elements 5a to 5d A plate 7 is provided (Japanese Unexamined Patent Application Publication No.
149652). It is known that the semiconductor laser elements 3 and 4 are formed on the same LOP 8 (Nikkei Electronics, June 28, 1999, pages 29 to 30).

Next, an outline of a conventional semiconductor device in which two light sources are integrated in a hybrid manner will be described with reference to FIG.

As shown in FIG. 15, in this semiconductor device 9, for example, a wavelength of about 6
A semiconductor laser element 11 that emits a laser beam L13 of 50 nm, and a laser beam L of a wavelength of about 780 nm for CD, for example.
A semiconductor laser element 12 that emits light, a plurality of photodetectors 13 and 14, and a microprism 15 that functions as a reflection mirror are provided in an integrated manner. Return light beam L from a recording medium (not shown)
There is provided an optical element (not shown) for allowing the light beams 13 'and L14' to enter the photodetectors 13 and 14 (Japanese Patent Application Laid-Open Nos. 9-120568 and 10-641).
07, JP-A-11-39693, JP-A-1
1-161993). The semiconductor laser elements 11 and 12 are mounted on the substrate 10 via mounts 17 and 18, respectively.

[0008]

However, the above-mentioned conventional configuration has the following problems.

First, in a conventional semiconductor device in which two light sources are monolithically integrated, a semiconductor laser element 3 is provided.
And the semiconductor laser element 4 are provided in parallel so that the emission end faces of the lasers are arranged in the same direction, so that the light emitting point interval between the semiconductor laser element 3 and the semiconductor laser element 4 is 100
It is difficult to reduce the thickness to less than μm. Therefore, the effects of the red laser and the infrared laser emitted from the two semiconductor laser elements 3 and 4 from the optical element are different from each other, and there is a problem that the operating characteristics of one semiconductor laser element are deteriorated. In particular, when one of the semiconductor laser elements 3 and 4 performs a high-output operation of 30 mW or more in a state where the semiconductor laser elements 3 and 4 are arranged close to each other, this occurs in one of the semiconductor laser elements. There is a problem that the heat is applied to the other semiconductor laser element to cause deterioration of the characteristics of the semiconductor laser element.

In a conventional semiconductor device in which two light sources are integrated in a hybrid, a micro prism 1
5 is arranged between the semiconductor laser element 11 and the semiconductor laser element 12, so that when the microprism 15 is displaced from a predetermined position, The optical paths of the emitted laser beams L13 and L14 are shifted. The semiconductor laser device 11 and the semiconductor laser device 12
The apparent light emitting point interval between the light emitting points (hereinafter referred to as the “light emitting point interval” includes the “apparent light emitting point interval”) varies, making it difficult to reduce the light emitting point interval. there were.

Further, in the above-described conventional semiconductor device, since the semiconductor laser element is mounted via a mount such as LOP8, the light emitting point interval is changed by the thickness variation of the mount. It will vary
There is a problem that it is difficult to reduce the light emitting point interval.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and can reduce a light emitting point interval between a plurality of semiconductor laser devices, and
An object of the present invention is to provide a semiconductor device and an optical pickup device that can prevent heat generated when a semiconductor laser element performs a high-power operation from reaching other semiconductor laser elements.

[0013]

In order to achieve the above object, a semiconductor device according to the present invention comprises a substrate, a projection formed on the substrate by processing the substrate, and having a plurality of side surfaces. And a plurality of semiconductor laser elements provided on the substrate, wherein the plurality of semiconductor laser elements are arranged with their respective end faces facing different side faces of the protrusion. According to the configuration of the semiconductor device, since the protrusion having the plurality of side surfaces is formed on the substrate, the micro prism is not required. Further, since the plurality of semiconductor laser elements can be arranged on a straight line, the interval between the light emitting points between the plurality of semiconductor laser elements can be reduced. Also, a plurality of semiconductor laser elements
Since the respective end faces are arranged so as to face different side surfaces of the protrusion, it is possible to prevent heat generated when the semiconductor laser element performs a high-power operation from reaching other semiconductor laser elements. Can be. As a result, characteristic deterioration of the semiconductor laser device can be prevented.

In the configuration of the semiconductor device of the present invention, it is preferable that the protrusion is formed in a truncated pyramid shape, and a light receiving element is provided on a top surface thereof. According to this preferred example, since the light receiving element can be arranged at one place, the size of the semiconductor device can be reduced.

Further, in the configuration of the semiconductor device of the present invention, the semiconductor device further includes a plurality of small protrusions formed on the substrate by processing the substrate, and a semiconductor laser element is mounted on each of the small protrusions. Preferably, it is located. According to this preferred example, it is possible to prevent a part of the laser beam emitted from the end face of the semiconductor laser element from being blocked by the surface of the substrate, particularly when the semiconductor laser element is p-side down mounted.

In the configuration of the semiconductor device of the present invention, it is preferable that a groove is formed on the substrate between the semiconductor laser element and the side surface of the protrusion. According to this preferred example, it is possible to prevent a part of the laser beam emitted from the end face of the semiconductor laser element from being blocked by the surface of the substrate.

In the configuration of the semiconductor device according to the present invention, the protrusion has four side surfaces forming an angle of 40 ° or more and 50 ° or less with respect to a main surface of the substrate, and the semiconductor laser has It is preferable that the element is arranged so that the emission end face of the main beam faces the side face of the protrusion. According to this preferred example, the main beam emitted from the semiconductor laser device can be reflected by the side surface of the protrusion and guided in a direction perpendicular to the substrate.

In the structure of the semiconductor device according to the present invention, the substrate is a silicon substrate, and a main surface of the substrate is inclined in a <1-10> direction in a range of 5 ° to 15 ° (100 degrees). It is preferable that, of the side surfaces of the protrusion, the surface facing the emission end surface of the main beam of the semiconductor laser element is the (111) surface. Here, <1-1
The 0> direction means a direction represented by the following (Equation 1).

[0019]

(Equation 1)

According to this preferred example, the angle of incidence of the main beam of the semiconductor laser device on the side surface of the protrusion can be made close to 45 °.

In the structure of the semiconductor device of the present invention, the substrate is a silicon substrate, and a main surface of the substrate is inclined in a <1-10> direction in a range of 1 ° to 11 ° (511). It is preferable that, of the side surfaces of the protrusion, the surface facing the emission end surface of the main beam of the semiconductor laser element is the (111) surface. According to this preferred example, the angle of incidence of the main beam of the semiconductor laser device on the side surface of the protrusion can be made close to 45 °.

In the configuration of the semiconductor device according to the present invention, the semiconductor device further includes a recess formed on the substrate by processing the substrate, the recess having a plurality of side surfaces, and the protrusion and the plurality of semiconductor laser elements are provided. It is preferably provided in the recess. Further, in this case, it is preferable that the plurality of semiconductor laser elements are arranged so that respective end faces opposite to the end face facing the side face of the protrusion face different side faces of the recess. In this case, further, a main beam is emitted from one end face of the semiconductor laser element, and a monitor light beam is emitted from the other end face, and the projection of the projection facing the emission end face of the monitor light beam is further emitted. It is preferable that a monitoring light receiving element for receiving the monitor light beam is provided on a side surface or the side surface of the concave portion. According to this preferred example, the output of the main beam emitted from the semiconductor laser device can be controlled. In this case, it is preferable that a light receiving element is provided on the outer periphery of the concave portion. According to this preferred example, since a plurality of light receiving elements can be arranged, the light receiving sensitivity of the semiconductor device can be improved. In this case, it is preferable that the light receiving element further includes a plurality of divided light receiving regions. According to this preferred example, highly accurate tracking error detection can be performed by calculating signals in a plurality of divided light receiving regions. Further, in this case, it is preferable that the divided direction of the light receiving element is a direction parallel to an end face of the semiconductor laser element. According to this preferred example, even when the semiconductor laser element is arranged at a position shifted from a predetermined position, the amount of the return light beam incident on the light receiving element can be hardly changed. In this case, it is preferable that a groove is formed on the substrate between the semiconductor laser device and the side surface of the concave portion. In this case, the substrate is a silicon substrate, the bottom surface of the recess is a (100) plane inclined in a range of 5 ° to 15 ° in a <1-10> direction, and a side surface of the recess is formed. It is preferable that the surface facing the emission end face of the main beam of the semiconductor laser element is the (111) plane. In this case, the substrate is a silicon substrate, the bottom surface of the concave portion is a (511) surface inclined in the <1-10> direction in a range of 1 ° or more and 11 ° or less, and the side surface of the concave portion is It is preferable that the surface facing the emission end face of the main beam of the semiconductor laser element is the (111) plane.

In a first configuration of the optical pickup device according to the present invention, a plurality of semiconductor laser elements, a plurality of light receiving elements, and a plurality of reflection surfaces are provided on a same substrate, and the plurality of semiconductor laser elements are provided. The device comprises: a semiconductor device in which each end face is arranged to face the different reflection surface; and a hologram element which is arranged on an optical axis of a light beam emitted from the semiconductor laser element and directed to an optical recording medium. It is characterized by having. According to the first configuration of the optical pickup device, the size of the semiconductor device itself can be reduced, so that the size of the optical pickup device can be reduced.

In a second configuration of the optical pickup device according to the present invention, there is provided a semiconductor device having a plurality of semiconductor laser elements, and a semiconductor device having a plurality of semiconductor laser elements arranged on an optical axis of a light beam emitted from the semiconductor laser elements and traveling toward an optical recording medium. An optical pickup device provided with a hologram element disposed therein, wherein the semiconductor device of the present invention is used as the semiconductor device.

In the first or second configuration of the optical pickup device according to the present invention, it is preferable that the hologram element has a plurality of diffraction gratings. According to this preferred example, return light from the optical recording medium originating from each of the plurality of semiconductor laser elements can be incident on each of the plurality of light receiving elements.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to embodiments.

It should be noted that the drawings referred to are merely schematic drawings and do not represent actual scales.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a perspective view showing a semiconductor device according to an embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view cut along a plane that is perpendicular to the main surface of the silicon substrate 104 and includes the same.

As shown in FIGS. 1 and 2, in the semiconductor device 101 of the present embodiment, a (100) plane having an off angle of 9.7 ° (hereinafter referred to as “(100)”) is used as a substrate.
9.7 ° off plane ”) as the main surface
04 is used.

On the main surface of the silicon substrate 104, a concave portion 105 having a depth of 200 μm is formed by using a silicon process. The recess 105 has a square bottom surface with a side length of 1.5 mm, and four slopes provided to surround the bottom surface. The bottom surface forming the concave portion 105 is a (100) 9.7 ° off surface, and the four sides forming the bottom surface are parallel to the <110> direction or the <1-10> direction. 4 forming the recess 105;
Slopes (these slopes are referred to as “outer faces”)
From the (111) plane, the (1-11) plane, the (-1-11) plane, and the (-111) plane (hereinafter, these planes are referred to as “(111) outer plane”, “(1-11) outer plane”, etc.) Become. Here, the (1-11) plane means a plane represented by the following (Equation 2). In addition, (-1-11) plane,
The same applies to the (-111) plane and the like.

[0031]

(Equation 2)

In the vicinity of the center of the concave portion 105, a truncated quadrangular pyramid having a height of 200 μm is formed using a silicon process.
Are formed. The protrusion 106 has a square bottom surface,
It is composed of four slopes and a top surface. Protrusion 10
The four sides forming the bottom surface constituting 6 are parallel to the <110> direction or the <1-10> direction. Further, four slopes constituting the protrusion 106 (hereinafter, these slopes are referred to as “inner faces”) are (111) face, (1-11) face,
It is composed of a (-1-11) plane and a (-111) plane (hereinafter, these planes are referred to as “(111) inner plane”, “(1-11) inner plane”, etc.). The top surface of the protrusion 106 is (10
0) It consists of a 9.7 ° off plane, and the length of one side forming the top surface is 50 μm.

Of the outer surface and the inner surface, the (111) outer surface and the (111) inner surface are the reflecting mirror surfaces 107 and 108.
It has become. Here, since the concave portion 105 and the convex portion 106 are formed using a silicon process, the reflecting mirror surfaces 107 and 108 can be manufactured with an accuracy of 1 μm or less. This is the same in the following second and third embodiments. Semiconductor laser elements 102 and 103 are fixed on small protrusions 112 and 113 formed on the recess 105 by using a silicon process, respectively. The semiconductor laser elements 102 and 103 are arranged such that their front end faces are parallel to the <110> direction and face the reflection mirror surfaces 107 and 108, respectively. A light receiving element 109 for receiving the return light beams L1 'and L2' from the optical disk is provided on the top surface of the protrusion 106, and the (-1-11) inner surface and the (--11) inner surface are provided.
1-11) The monitor light receiving element 11 is provided on the outer surface.
0 and 111 are provided. Monitor light receiving element 11
0 and 111 are the semiconductor laser elements 102 and 10 respectively.
Monitor light beams L1 ″, L1 emitted from the rear end face
By monitoring the output of 2 ″, the semiconductor laser elements 102, 1
This is for adjusting the output of the main beam emitted from the front end face of the laser beam 03. The small protrusions 112 and 113 have a shape similar to the protrusion 106, and have a height of 5
0 μm.

As shown in FIG. 2, the semiconductor laser device 10
Reference numerals 2 and 103 are fixed by a solder material (not shown) so that the crystal growth surface side (light emitting portion side) is on the lower side.
Note that the two semiconductor laser elements 102 and 103 are arranged such that their beam emission points are aligned on a straight line.

In the above structure of the semiconductor device, (11
1) The outer surface and the (111) inner surface are inclined at an angle of 45 ° with respect to the bottom surface of the concave portion 105. The concave portions 105, the convex portions 106, and the small convex portions 112 and 113 form an oxide film etching mask on the silicon substrate 101, and are etched using a solution that realizes anisotropic etching such as an aqueous solution of potassium hydroxide or ethylenediamine. By doing so, it can be easily formed.

On the surfaces of the reflecting mirror surfaces 107 and 108,
A gold film (not shown) having a thickness of 300 to 500 nm is formed, and the reflectance of the reflection mirror surfaces 107 and 108 is 90.
% Or more. With this configuration, the main beams L1 and L2 emitted in the horizontal direction from the front end surfaces of the semiconductor laser elements 102 and 103 are respectively reflected by the reflection mirror surface 107 and the reflection mirror surface 107.
The light is reflected at 108 and travels in the direction of an optical disk (not shown) perpendicular to or substantially perpendicular to the main surface of the silicon substrate 104, and is reflected by the optical disk.

According to the present embodiment, the two semiconductor laser elements 102 and 103 can be arranged on a straight line.
03 can be reduced. In addition, the two semiconductor laser elements 102 and 103
6, the heat generated when one semiconductor laser element is operated at a high output of 30 W or more is less likely to reach the other semiconductor laser element. As a result, characteristic deterioration of the semiconductor laser device is prevented.

In particular, the incident angles of the main beams L1 and L2 of the semiconductor laser device 102 with respect to the side surface of the concave portion 105 and the semiconductor laser device 103 with respect to the side surface of the protrusion 106 can be made close to 45 degrees.

In particular, the semiconductor laser elements 102, 1
03 are fixed on the small protrusions 112 and 113, respectively. By doing so, particularly when the semiconductor laser elements 102 and 103 are p-side down mounted, that is, the p of the semiconductor laser elements 102 and 103 is When the semiconductor laser elements 102 and 103 are mounted such that the side electrodes face, for example, the small protrusions 112 and 113, a part of the main beam emitted from the front end face of the semiconductor laser elements 102 and 103 It can be prevented from being blocked by the bottom surface.

Semiconductor laser 1 used in this embodiment
02 and 103 are AlGa having a wavelength of 780 nm.
An As-based laser, an AlGaInP-based laser having a wavelength of 650 nm, or a GaN-based laser having a wavelength of 420 nm can be given. Then, by using any two of these, a two-wavelength semiconductor laser device can be obtained. Further, for example, AlGaInP having a wavelength of 650 nm is used.
Two semiconductor lasers having the same wavelength, such as a high-power laser and an AlGaInP self-pulsation laser, may be used.

By arranging the two semiconductor laser elements 102 and 103 on a straight line, the semiconductor laser element 10
With reference to FIG. 3, a description will be given of the fact that the light emitting point interval between the semiconductor laser device 103 and the semiconductor laser element 103, that is, the apparent light emitting point interval can be reduced. In FIG. 3, the semiconductor device 101 is the same as that shown in FIG. 1, and is mounted in the housing 115 and sealed with a cover glass 116. Further, the hologram element 114 is placed on the cover glass 116.

As shown in FIG. 3, the semiconductor laser device 10
The main beams L1 and L2 emitted in the horizontal direction from the mirrors 2 and 103 are reflected by the reflecting mirror surfaces 107 and 108, respectively, and travel in the vertical direction or a direction close to the vertical direction. At this time, the reflection mirror surfaces 107 and 1 of the laser beams emitted from the semiconductor laser elements 102 and 103, respectively.
If the angles of incidence on each of the two main beams L are respectively selected in the hologram element 114, for example,
1 and L2 can intersect at one point, that is, the luminous point interval between the semiconductor laser element 102 and the semiconductor laser element 103 in the hologram element 114 can be made zero.

Next, an optical pickup device using the semiconductor device 101 as a semiconductor laser device will be described with reference to FIG.

As shown in FIG. 4, in this optical pickup device, a hologram element 114 and a collimator lens 117 are sequentially arranged on main beams L1 and L2 emitted from a semiconductor device 101. Hologram element 1
14 and the collimator lens 117 are
The main beams L1 and L2 are arranged on the top so as to be focused. Then, the return light beam from the optical disk 118 passes through the collimator lens 117 and the hologram element 114 in order, and is incident on the semiconductor device 101 again.
09 (see FIGS. 1 and 2) as information of the optical disk 118.

In the configuration of the optical pickup device, since the semiconductor device 101 capable of reducing the light emitting point interval between the plurality of semiconductor laser elements is used, the optical system such as a lens can be further simplified. . As a result, an inexpensive optical pickup device can be realized.

In this embodiment, the protrusion 106
The light receiving element 109 for receiving the return light beam from the optical disk is provided on the top surface of the optical disk, but is not necessarily limited to this configuration. For example, as shown in FIG.
May be provided on the outer periphery.

In the present embodiment, the semiconductor laser elements 102 and 103 are connected to the crystal growth surface side (light emitting portion side).
Is fixed on the lower side, but the crystal growth surface side (light emitting portion side) may be fixed on the upper side. But,
When the semiconductor laser elements 102 and 103 are fixed so that the crystal growth surface side (light emitting portion side) is on the upper side, the thickness variation of the semiconductor laser elements 102 and 103 themselves becomes as large as 20 μm, and the variation of the light emitting point position varies. Therefore, it is desirable to fix the semiconductor laser elements 102 and 103 such that the crystal growth surface side is on the lower side. If the semiconductor laser elements 102 and 103 are fixed such that the crystal growth surface side is on the lower side, the variation in the light emitting point position, that is, the variation in the crystal growth film of the semiconductor laser elements 102 and 103 (about 2 μm) can be achieved. It is suppressed and more effective. In this case, the small protrusions 112, 113
If a groove is formed between the front end faces of the semiconductor laser elements 102 and 103 and the reflecting mirror surfaces 107 and 108 instead of the above, a part of the main beam emitted from the front end faces of the semiconductor laser elements 102 and 103 will Can be prevented from being interrupted by the bottom surface. This is the same in the following second and third embodiments.

In the present embodiment, the (100) plane having an off-angle of 9.7 ° with respect to the <1-10> direction is used as the main surface of the silicon substrate 104. With an off-angle of ~ 15 ° (10
In the case of the (0) plane, the inclination of the reflecting mirror surfaces 107 and 108 with respect to the surface of the silicon substrate 104 can be suppressed within the range of 40 ° ≦ θ ≦ 50 °, and the reflecting mirror surfaces 107 and 108 having the inclination of approximately 45 ° are formed. As a result, a similar effect can be obtained. Further, as a silicon substrate equivalent to the silicon substrate 104, a substrate having a (511) plane as a main surface having an off angle of 1 to 11 ° about a <1-10> direction as an axis,
The same effect can be obtained by using an equivalent substrate having an appropriate off-angle set from other crystal planes. This is the same in the following second and third embodiments.

[Second Embodiment] FIG. 6 shows a second embodiment of the present invention.
FIG. 14 is a perspective view showing a semiconductor device in the embodiment.

As shown in FIG. 6, in the semiconductor device 201 of the present embodiment, the semiconductor device 201 according to the first embodiment is placed on the (100) 9.7 ° off plane which is the main surface of the silicon substrate 206. A recess 207 and a protrusion 208 having similar dimensions are formed.

The (111) inner surface constituting the protrusion 208 and three surfaces forming an angle of 45 ° with the (100) 9.7 ° off surface (hereinafter, these surfaces are viewed from above the protrusion Clockwise, “α inner surface”, “β inner surface”, and “γ inner surface” are the reflecting mirror surfaces 209, 210, 211, and 21.
It is 2. Small protrusion 2 formed on recess 207
Semiconductor laser elements 202, 203, 204, and 205 are fixed on 18, 219, 220, and 221 respectively. Semiconductor laser elements 202, 203, 204,
205 is arranged so that its front end surface is parallel to each of the four sides forming the bottom surface of the projection 208 and faces the reflection mirror surfaces 209, 210, 211, 212, respectively. On the top surface of the protrusion 208, return light beams L3 ', L4', L5 ', L6' from the optical disk are provided.
The light receiving element 213 for receiving the
(111) outer surface constituting (7) and (100) 9.7 °
Three surfaces forming an angle of 45 ° with the off surface (hereinafter referred to as “α outer surface”, “β outer surface”, and “γ outer surface” in a counterclockwise direction when viewed from above the concave portion 207) are respectively provided. Monitoring light receiving elements 214, 215, 216, and 217 are provided. Monitor light receiving elements 214, 215, 21
6, 217 are semiconductor laser elements 202, 20 respectively.
The outputs of the monitor light beams L3 ″, L4 ″, L5 ″, L6 ″ emitted from the rear end surfaces of the semiconductor laser elements 202, 203, 204, 20 are monitored.
5 is for adjusting the output of the main beam emitted from the front end face of the main beam 5.

The projections 208 and the small projections 218, 219,
For example, as shown in FIG. 7, the masks 220 and 221 can be formed by forming a mask 222 on a silicon substrate 206 and performing reactive ion etching (RIE). In addition, small projections 21
8, 219, 220, and 221 have a shape similar to the protrusion 208, and each has a height of 50 μm.

Semiconductor laser elements 202, 203, 20
Reference numerals 4 and 205 are fixed by a solder material (not shown) so that the crystal growth surface side (light emitting unit side) is on the lower side.

Reflecting mirror surfaces 209, 210, 211, 2
Similarly to the first embodiment, a gold film (not shown) having a thickness of 300 to 500 nm is formed on the surface of the mirror 12, and the reflection mirror surfaces 209, 210, 211, and 212 are formed.
Is 90% or more. With this configuration,
The main beams L3, L4, which are horizontally emitted from the front end faces of the semiconductor laser elements 202, 203, 204, 205,
L5 and L6 are reflecting mirror surfaces 209 and 210, respectively.
The light is reflected by 211 and 212 and travels in the direction of an optical disk (not shown) perpendicular or nearly perpendicular to the main surface of the silicon substrate 206, and is reflected by the optical disk.
Then, return light beams L3 ′, L
4 ′, L5 ′ and L6 ′ enter the light receiving element 213 and are extracted as signals.

According to the present embodiment, the semiconductor laser element 202 and the semiconductor laser element 204 can be arranged on a straight line, and the semiconductor laser element 203 and the semiconductor laser element 205 can be arranged on a straight line. Therefore, the interval between the light emitting points between the plurality of semiconductor laser elements can be reduced.

In particular, the incident angles of the main beams L3, L4, L5, and L6 of the semiconductor laser elements 202, 203, 204, and 205 with respect to the side surface of the projection 208 can be made close to 45 degrees.

Further, since the light receiving element 213 is provided on the top surface of the projection 208, the semiconductor laser element 20 is provided.
Since the area of the silicon substrate 204 on which the light receiving elements 213, 204, 205, and 205 are disposed can be made smaller, the size of the optical pickup device can be reduced.

As examples of the semiconductor laser elements 202, 203, 204, and 205 used in this embodiment, an AlGaAs laser having a wavelength of 780 nm, an AlGaInP laser having a wavelength of 650 nm, or a GaN laser having a wavelength of 420 nm can be given. . By using these in combination, a multi-wavelength semiconductor laser device can be obtained. Further, for example, at a wavelength of 650 nm,
Semiconductor lasers having the same wavelength, such as an AlGaInP-based high-power laser and an AlGaInP-based self-pulsation laser, may be used.

The following (Table 1) shows the semiconductor laser device 20
Specific combinations of 2, 203, 204, 205;
This shows the relationship with a readable or writable optical disk.

[0060]

[Table 1]

Semiconductor device 20 as semiconductor laser device
The optical pickup device constituted by using the first
This is the same as the embodiment. That is, in the configuration of the optical pickup device, since the semiconductor device 201 as a semiconductor laser device capable of reducing the light emitting point interval between a plurality of semiconductor laser elements is used, the optical system such as a lens is simplified. can do. as a result,
An inexpensive optical pickup device can be realized.

[Third Embodiment] FIG. 8 shows a third embodiment of the present invention.
FIG. 14 is a perspective view showing a semiconductor device in the embodiment.

As shown in FIG. 8, in the semiconductor device 301 of the present embodiment, a recess 307 having a depth of 200 μm is formed on the (100) 9.7 ° off plane which is the main surface of the silicon substrate 306. Have been. The concave portion 307 includes a cross-shaped bottom surface having a side length of 0.5 mm and twelve inclined surfaces provided so as to surround the bottom surface. The bottom surface forming the concave portion 307 is a (100) 9.7 ° off surface, and the 12 sides forming the bottom surface are <110>
Direction or <1-10> direction. Also,
12 slopes (hereinafter these slopes are referred to as "outer faces")
Consists of three types of planes that form an angle of 45 ° with the (111) plane and the (100) 9.7 ° off plane.

In the vicinity of the center of the recess 307, a height of 200 μm
An m-shaped truncated pyramid-shaped protrusion 308 is formed. Bump 3
08 includes a square bottom surface, four slopes, and a top surface. The four sides forming the bottom are <11
It is parallel to the <0> direction or the <1-10> direction. The four slopes forming the protrusion 308 include a (111) inner surface, an α inner surface, a β inner surface, and a γ inner surface. The top surface forming the protrusion 308 is a (100) 9.7 ° off surface, and the length of one side forming the top surface is 50 μm.

The (111) inner surface, the α inner surface, the β inner surface, and the γ inner surface constituting the protrusion 308 are reflecting mirror surfaces 309 and 31.
0, 311 and 312. On the small protrusions 318, 319, 320, 321 formed on the recess 307, the semiconductor laser elements 302, 303, 30
4 and 305 are fixed. Semiconductor laser device 30
2, 303, 304, and 305 have their front end faces protruding 3
08 are arranged so as to be parallel to each of the four sides and to face the reflection mirror surfaces 309, 310, 311 and 312, respectively. Further, on the outer periphery of the concave portion 307, return light beams L7 ′, L8 ′, L
Light receiving elements 313a to 313a for receiving 9 'and L10'
13d is provided. Each light receiving element 313a to 313
“d” has a light receiving area that is elongated and divided into three parts in the direction from the protrusion 308 to each of the light receiving elements 313a to 313d. In this way, the light receiving elements 313a to 313d can
The division enables tracking error detection by the three-beam method, so that highly accurate tracking detection is possible. Semiconductor laser elements 302, 303, 30
Monitor light-receiving elements 314, 315, 316, and 317 are provided on four outer surfaces facing each of the light-receiving elements 4 and 305, respectively. Monitor light receiving elements 314, 315, 3
16 and 317 are semiconductor laser elements 302 and 3 respectively.
Monitor the outputs of the monitor light beams L7 ", L8", L9 ", L10" emitted from the rear end surfaces of the semiconductor laser elements 302, 303, 304,
This is for adjusting the output of the main beam emitted from the front end face of the 305.

The protrusions 308 and the small protrusions 318, 319,
320 and 321 form a mask on the silicon substrate 306 and perform reactive ion etching (RIE).
on Etching). In addition, the small protrusions 318, 319, 320, 321 are:
It has a shape similar to the protrusion 308, and each has a height of 50 μm.

Semiconductor laser elements 302, 303, 30
Reference numerals 4 and 305 are fixed by a solder material (not shown) such that the crystal growth surface side (light emitting portion side) is on the lower side.

Reflecting mirror surfaces 309, 310, 311 and 3
As in the first embodiment, a gold film (not shown) having a thickness of 300 to 500 nm is formed on the surface of the mirror 12, and the reflectance of the reflecting mirror surfaces 309, 310, 311 and 312 is changed. Is 90% or more. With this configuration, the main beams L7, L8, L emitted in the horizontal direction from the front end faces of the semiconductor laser elements 302, 303, 304, 305
9, L10 are reflecting mirror surfaces 309, 310, respectively.
The light is reflected by 311 and 312, travels in the direction of an optical disk (not shown) perpendicular to or substantially perpendicular to the main surface of the silicon substrate 306, and is reflected by the optical disk.
Then, return light beams L7 ′, L
8 ′, L9 ′, and L10 ′ are light receiving elements 313a to 313a, respectively.
313d, and is extracted as a signal.

According to the present embodiment, the semiconductor laser element 302 and the semiconductor laser element 304 can be arranged on a straight line, and the semiconductor laser element 303 and the semiconductor laser element 305 can be arranged on a straight line. Therefore, the interval between the light emitting points between the plurality of semiconductor laser elements can be reduced.

In particular, the incident angles of the main beams L7, L8, L9, L10 of the semiconductor laser elements 302, 303, 304, 305 with respect to the side surfaces of the protrusion 308 are set to 45.
Can approach the degree.

Examples of the semiconductor laser elements 302, 303, 304, and 305 used in the present embodiment include an AlGaAs laser having a wavelength of 780 nm, an AlGaInP laser having a wavelength of 650 nm, and a GaN laser having a wavelength of 420 nm. . By using these in combination, a multi-wavelength semiconductor laser device can be obtained. Further, for example, at a wavelength of 650 nm,
AlGaInP-based high-power lasers and AlGaInP-based self-pulsating lasers, such as 780 nm wavelength AlGaAs-based high-power lasers and AlGaAs-based self-pulsating lasers,
Two types of two wavelengths may be used.

The following Table 2 shows that the semiconductor laser element 30
Specific combinations of 2, 303, 304, and 305;
This shows the relationship with a readable or writable optical disk.

[0073]

[Table 2]

Next, an optical pickup device using the semiconductor device 301 as a semiconductor laser device will be described with reference to FIG. The basic configuration of this optical pickup device is the same as that of the first embodiment.

As shown in FIGS. 8 and 9, in this optical pickup device, a hologram element 324 and a collimator lens 325 are sequentially arranged on a main beam L7, L8, L9, L10 emitted from a semiconductor device 301. Have been. Hologram element 324 and collimator lens 325
Means that the main beams L7, L8, L
9, L10 are arranged so as to be focused. The semiconductor device 301 is placed in the housing 322 and sealed with a cover glass 323. Hologram element 324
Are placed on the cover glass 323. Then, the return light beam from the optical disk 326 sequentially passes through the collimator lens 325 and the hologram element 324,
The light enters the semiconductor device 301 again, and the light receiving elements 313a to 313a
13d, it is detected as information of the optical disk 326.

As shown in FIG. 10A, the hologram element 3
24 has a main beam L on the side facing the semiconductor device 301.
A diffraction grating 327 is provided for separating each of 7, L8, L9, and L10 into 0th, + 1st, and -1st order diffracted light. Further, as shown in FIG. 10B, the hologram element 324 returns to the side facing the optical disk 326 to guide each of the light beams L7 ′, L8 ′, L9 ′, and L10 ′ to each of the light receiving elements 313a to 313d. A diffraction grating 328 is provided.

In the configuration of this optical pickup device, since the semiconductor device 301 capable of reducing the light emitting point interval between the plurality of semiconductor laser elements is used, the optical system such as a lens can be further simplified. . As a result, an inexpensive optical pickup device can be realized.

In this embodiment, each of the light receiving elements 313a to 313d is moved from the projection 308 to each of the light receiving elements 31a to 313d.
It is configured to have the light receiving area divided into three elongated in the direction toward 3a to 313d, but is not necessarily limited to this configuration. For example, as shown in FIG. 11, each of the light receiving elements 313a to 313d is divided into semiconductor laser elements 302, 303, 3
04, 305 may be arranged along or parallel to the respective end faces. With this configuration, the semiconductor laser elements 302, 303, 304,
Even if the position where the 305 is placed is shifted, the return light beams L7 ', L8', L9 ', L
10 'only needs to be shifted in the direction in which the light receiving elements 313a to 313d are divided, so that the light receiving elements 313a to 313d
Return light beams L7 ', L8', L
The amounts of 9 'and L10' hardly change. That is, as shown in FIG.
By arranging d, it is possible to alleviate the requirement for the assembly accuracy of the optical pickup device, so that the assembly yield of the optical pickup device can be improved.

In the first to third embodiments, a silicon substrate having a (100) 9.7 ° off-plane as a main surface is used as a silicon substrate, but is not necessarily limited to this configuration. Not something. In particular, when providing a concave portion, a protrusion and a small protrusion by performing reactive ion etching, (1)
00) Similar effects can be obtained by using a silicon substrate having a just surface as a main surface instead. In performing this reactive ion etching, if the thickness of the resist formed as a mask on the silicon substrate is changed in the plane as shown in FIGS.
As shown in FIG. 3B, the angle of the reflecting mirror surface can be changed. This makes it possible to adjust the angle of the reflecting mirror surface as designed.

In the first to third embodiments, the truncated quadrangular pyramid is used as the protrusion, but the shape of the protrusion is not necessarily limited to this. For example, a protrusion having a shape of a truncated pyramid or a truncated hexagon may be used, and the semiconductor laser device may be arranged so as to face each side surface forming the protrusion. In particular, in the third embodiment, a pointed protrusion such as a triangular pyramid, a quadrangular pyramid, or a hexagonal pyramid may be used.

Further, in the first to third embodiments, the case where the shape of the bottom surface forming the concave portion is a square or a cross is described as an example, but the present invention is not necessarily limited to this structure. is not. The shape of the bottom surface forming the concave portion may be, for example, a rectangle, a hexagon, an octagon, or the like.

[0082]

As described above, according to the present invention,
The distance between the light emitting points between the plurality of semiconductor laser elements can be reduced, and the heat generated when the semiconductor laser element performs a high-power operation can be prevented from reaching other semiconductor laser elements. Further, an optical system such as a lens can be further simplified, and an inexpensive optical pickup device can be realized.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is a sectional view showing a state of a main beam emitted from the semiconductor device according to the first embodiment of the present invention;

FIG. 4 is a sectional view showing an optical pickup device according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing another example of the semiconductor device according to the first embodiment of the present invention;

FIG. 6 is a perspective view showing a semiconductor device according to a second embodiment of the present invention.

FIG. 7 is a sectional view showing a state of reactive ion etching used in a second embodiment of the present invention.

FIG. 8 is a perspective view showing a semiconductor device according to a third embodiment of the present invention.

FIG. 9 is a sectional view showing an optical pickup device according to a third embodiment of the present invention.

FIG. 10A is a view of a hologram element used in an optical pickup device according to a third embodiment of the present invention as viewed from a side facing a semiconductor device, and FIG. 10B is a view of the hologram element as viewed from a side facing an optical disk.

FIG. 11 is a perspective view showing another example of the semiconductor device according to the third embodiment of the present invention;

FIG. 12 is a sectional view showing a step of forming a reflection mirror surface on a silicon substrate in the embodiment of the present invention.

FIG. 13 is a sectional view showing another example of the step of forming the reflection mirror surface on the silicon substrate in the embodiment of the present invention.

FIG. 14 is a perspective view showing a semiconductor device according to a conventional technique.

FIG. 15 is a cross-sectional view illustrating another example of a semiconductor device in the related art.

[Explanation of symbols]

101, 201, 301 Semiconductor devices 102, 103, 202, 203, 204, 205, 3
02, 303, 304, 305 Semiconductor laser elements 104, 206, 306 Silicon substrate 105, 207, 307 Concave parts 106, 208, 308 Convex parts 107, 108, 209, 210, 211, 212, 3
09, 310, 311, 312 Reflecting mirror surface 109, 213, 313a, 313b, 313c, 31
3d light receiving element 110, 111, 214, 215, 216, 217, 3
14, 315, 316, 317 light receiving element for monitoring 112, 113, 218, 219, 220, 221, 3
18, 319, 320, 321 Small protrusion 114, 324 Hologram element 115, 322 Housing 116, 323 Cover glass 117, 325 Collimator lens 118, 326 Optical disk 222 Mask 327, 328 Diffraction grating

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01S 5/40 H01S 5/40

Claims (19)

[Claims] 1. A semiconductor device comprising: a substrate; a projection formed on the substrate by processing the substrate, the projection having a plurality of side surfaces; and a plurality of semiconductor laser elements provided on the substrate. A semiconductor device in which a laser element is arranged such that each end face is opposed to a different side face of the protrusion. 2. The semiconductor device according to claim 1, wherein the protrusion is formed in a truncated pyramid shape, and a light receiving element is provided on a top surface thereof. 3. The semiconductor device according to claim 1, further comprising a plurality of small protrusions formed on said substrate by processing said substrate, wherein a semiconductor laser element is mounted on each of said small protrusions. . 4. The semiconductor device according to claim 1, wherein a groove is formed on said substrate between said semiconductor laser element and said side surface of said protrusion. 5. The semiconductor device according to claim 1, wherein the protrusion is 40 degrees with respect to a main surface of the substrate.
2. The semiconductor device according to claim 1, wherein the semiconductor laser device has four side surfaces forming an angle of not less than 50 ° and not more than 50 °, and the semiconductor laser element is arranged so that an emission end surface of the main beam faces the side surface of the protrusion. . 6. The substrate is a silicon substrate, a main surface of the substrate is a (100) plane inclined in a range of 5 ° to 15 ° in a <1-10> direction, and a side surface of the protrusion is provided. 2. The semiconductor device according to claim 1, wherein a surface of the semiconductor laser element facing an emission end surface of the main beam is a (111) plane. 3. 7. The substrate is a silicon substrate, a main surface of the substrate is a (511) plane inclined in a range of 1 ° to 11 ° in a <1-10> direction, and a side surface of the protrusion is provided. 2. The semiconductor device according to claim 1, wherein a surface of the semiconductor laser element facing an emission end surface of the main beam is a (111) plane. 3. 8. The semiconductor device according to claim 1, further comprising a recess formed on the substrate by processing the substrate, the recess having a plurality of side surfaces, and the protrusion and the plurality of semiconductor laser devices being provided in the recess. Semiconductor device. 9. The semiconductor device according to claim 8, wherein the plurality of semiconductor laser devices are arranged such that respective end surfaces opposite to an end surface facing the side surface of the protrusion face different side surfaces of the concave portion. apparatus. 10. A main beam is emitted from one end surface of the semiconductor laser device, and a monitor light beam is emitted from the other end surface, and the side surface of the projection facing the emission end surface of the monitor light beam. 10. The semiconductor device according to claim 9, wherein a monitoring light receiving element for receiving the monitor light beam is provided on a side surface of the concave portion. 11. The semiconductor device according to claim 8, wherein a light receiving element is provided on an outer periphery of said concave portion. 12. The semiconductor device according to claim 11, wherein said light receiving element has a plurality of divided light receiving regions. 13. The semiconductor laser device according to claim 1, wherein the divided direction of the light receiving element is a direction parallel to an end face of the semiconductor laser element.
3. The semiconductor device according to 2. 14. The semiconductor device according to claim 8, wherein a groove is formed on said substrate between said semiconductor laser device and a side surface of said concave portion. 15. The substrate is a silicon substrate, the bottom surface of the recess is a (100) plane inclined in a range of 5 ° to 15 ° in a <1-10> direction, and the side surface of the recess is 9. The semiconductor device according to claim 8, wherein the surface of the semiconductor laser element facing the emission end face of the main beam is a (111) plane. 16. The substrate is a silicon substrate, the bottom surface of the recess is a (511) plane inclined in a <1-10> direction in a range of 1 ° or more and 11 ° or less, and the side surface of the recess is 9. The semiconductor device according to claim 8, wherein the surface of the semiconductor laser element facing the emission end face of the main beam is a (111) plane. 17. A plurality of semiconductor laser elements, a plurality of light receiving elements, and a plurality of reflection surfaces are provided on the same substrate, and
The plurality of semiconductor laser elements are arranged on the optical axis of a light beam emitted from the semiconductor laser element and directed toward an optical recording medium, wherein the semiconductor device is arranged so that each end face is opposed to the different reflecting surface. An optical pickup device including a hologram element. 18. An optical pickup device comprising: a semiconductor device having a plurality of semiconductor laser elements; and a hologram element disposed on the optical axis of a light beam emitted from the semiconductor laser elements and traveling toward an optical recording medium. 17. An optical pickup device, wherein the semiconductor device according to claim 1 is used as the semiconductor device. 19. The optical pickup device according to claim 17, wherein the hologram element has a plurality of diffraction gratings.