JP4729893B2 - Manufacturing method of semiconductor optical device - Google Patents

Description

The present invention relates to a method of manufacturing a semiconductor optical device.

  2. Description of the Related Art Conventionally, as a semiconductor optical device, for example, a semiconductor laser and a microlens formed integrally with a semiconductor substrate are provided, and the semiconductor laser is disposed in a semiconductor laser guide groove formed on the semiconductor substrate. There are some (see, for example, Patent Document 1).

This is manufactured as follows. First, the etched portions of the semiconductor substrate, after forming a SiO ₂ film by a sputtering method to form the microlens by etching the SiO ₂ film. Furthermore, a semiconductor laser guide groove is formed by etching the semiconductor substrate. Finally, a semiconductor laser is placed in the semiconductor laser guide groove.

By disposing the semiconductor laser in the semiconductor laser guide groove in this way, the distance between the microlens and the semiconductor laser can be easily controlled. Therefore, according to this manufacturing method, the positioning of the microlens and the semiconductor laser can be facilitated, and their optical coupling efficiency can be increased.
JP-A-5-241047

  However, in the semiconductor optical device manufacturing method described above, the microlens and the semiconductor laser guide groove are formed in separate etching processes. Variation in positioning occurs. Such a problem occurs not only in the positioning of the microlens and the semiconductor lens but also in the positioning of other optical components.

  In view of the above points, an object of the present invention is to improve the positioning accuracy between optical components as compared with the prior art.

In order to achieve the above object, according to the first aspect of the present invention, the first optical component formation region ( 30 ) in the semiconductor substrate (1) is formed in the first optical component by etching the semiconductor substrate (1). A first step of forming a positioning structure (1c) on the semiconductor substrate (1) for determining the position of the second optical component ( 2 ) simultaneously with processing into the contour shape of the component ( 1a ); A second step of forming the first optical component ( 1a ) in the planned formation region ( 30 ) of the optical component, and the second optical component ( 2 ) in contact with the positioning structure (1 c) A third step of mounting the second optical component ( 2 ) on the substrate (1),
In the first step, a plurality of trenches (33) are formed in the formation planned region ( 30 ) of the first optical component in the semiconductor substrate (1),
In the second step, the inside of the trench (33) is filled with the oxide (37) of the material constituting the semiconductor substrate (1), and the trench sidewall (36) located between the trenches (33) is oxidized. The first optical component ( 1a ) is formed by replacing the object (37).

  In the present invention, in the first step, the formation region of the first optical component of the semiconductor substrate is processed by one etching, and the positioning structure portion is formed on the same semiconductor substrate, and the second step. Thus, the first optical component is formed in the region where the first optical component is to be formed.

  Therefore, the relative position between the first optical component and the positioning structure is determined by the etching accuracy. Thereby, as compared with the case where the first optical component and the positioning structure are separately formed as in the conventional technique described above, the positioning of the first optical component and the positioning structure is highly accurate. It can be carried out.

  In the present invention, since the second optical component is brought into contact with the positioning structure and mounted on the semiconductor substrate in the third step, the positioning of the first optical component and the second optical component is performed. The accuracy can be improved as compared with the conventional technique, and the optical coupling efficiency between the optical components can be improved as compared with the conventional technique.

Specifically, as shown in claim 4, in the first step, in the positioning structure (1c), the contact surface (2a) with the second optical component ( 2 ) is the first optical component. The positioning structure portion (1c) is formed so as to be positioned on the second optical component side with respect to the surface (21) facing the second optical component in the component. Then, in the third step, by contacting the second optical component positioning structure (1c) (2), the distance between the first optical component (1a) and a second optical component (2) It can be set to a predetermined size.

  Thereby, the necessary distance between the first optical component and the second optical component can be ensured. That is, the distance between the first optical component and the second optical component can be controlled with higher accuracy than in the prior art.

In the first step, when the second optical component ( 2 ) is mounted on the semiconductor substrate (1) in the third step, the first step in the second optical component ( 2 ) is performed. The positioning structure portion (1c) can be arranged so that a part (2a) of the surface facing one optical component is in contact with the positioning structure portion (1c).

  If the entire region of the surface of the second optical component that faces the first optical component is brought into contact with the positioning structure, if a foreign object enters somewhere in these contacting regions, There arises a problem that the distance between the first optical component and the second optical component changes.

Therefore, in the invention described in claim 5 , the second optical component is not the entire region of the surface facing the first optical component, but a part of the surface is brought into contact with the positioning structure portion, thereby the second optical component. Compared with the case where the entire region of the surface facing the first optical component in this optical component is brought into contact with the positioning structure portion, the contact area is reduced.

  Thereby, compared with the case where the whole area | region of the surface facing the 1st optical component in a 2nd optical component is made to contact with the structure part for positioning, the probability that a foreign material will enter into a contact area can be reduced.

As the first optical component, for example, as shown in claim 6, it is possible to form the microlens.

According to a second aspect of the present invention, in the first step, the formation planned region (40) of the third optical component (3) in the semiconductor substrate is further processed into the contour shape of the third optical component (3). At the same time, a plurality of trenches (33) are formed also in the formation planned region (40) of the third optical component, and in the second step, the inside of the trench (33) is an oxide of a material constituting the semiconductor substrate. The third optical component (3) can also be formed by replacing the trench sidewall (36) located between the trenches (33) with an oxide.

  Thereby, the relative positions of the first optical component and the third optical component are also determined only by the etching accuracy. Therefore, as compared with the case where the first optical component and the third optical component are formed on different semiconductor substrates, the positioning of the first optical component and the third optical component can be performed with high accuracy. As a result, the optical axis of the entire semiconductor optical device can be aligned with high accuracy.

As the first optical component and the third optical component, for example, as shown in claim 7 , a microlens (1a) and an optical waveguide (3) can be formed, respectively .

Further, as shown in claim 8, as a second optical component, for example, it is possible to form a laser diode (2) or light-emitting diodes.

In the invention according to claim 3, in the first step, the first optical component is used in order to make the optical axis of the first optical component ( 1a ) coincide with the optical axis of the second optical component (2). A plurality of trenches (33) having a predetermined depth are formed in the formation planned region ( 30 ).

When the first optical component is formed by the method according to claim 1 , the position of the optical axis of the first optical component on the semiconductor substrate is determined by the depth of the trench formed in the formation region of the first optical component. Determined by Therefore, the optical axis of the first optical component and the optical axis of the second optical component can be matched by adjusting the depth of the trench in the region where the first optical component is to be formed. .

In the invention described in claim 9, in the third step, a predetermined thickness is used in order to make the optical axis of the first optical component ( 1a ) coincide with the optical axis of the second optical component ( 2 ). The second optical component (2) formed on the substrate is prepared, and the second optical component (2) is mounted on the semiconductor substrate (1).

  The height of the optical axis of the second optical component is determined by the thickness of the substrate on which the second optical component is formed. Therefore, by adjusting the thickness of the substrate on which the second optical component is formed, the optical axis of the first optical component and the optical axis of the second optical component can be matched.

Further, as shown in claim 10 , by mounting the second optical component (2) on the semiconductor substrate (1) via the submount material (7) and adjusting the thickness of the submount material. The optical axis of the first optical component and the optical axis of the second optical component can be matched.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
FIG. 1 is a perspective view of a semiconductor optical device according to the first embodiment of the present invention. 2 is a cross-sectional view taken along the line AA ′ of the semiconductor optical device in FIG. 1, and FIG. 3 is a perspective view of a region B indicated by a broken line in FIGS. In FIG. 1, the heat sink is omitted.

  The semiconductor optical device of this embodiment includes a first microlens 1a as a first optical component, a second microlens substrate 4 mounted independently of the microlens 1a, and a laser as a second optical component. A diode substrate 2, an optical waveguide 3 as a third optical component, and a heat sink 6 are provided.

  The first microlens 1a is a plano-convex cylindrical lens, and has a flat entrance surface 21 and an exit surface 22 composed of a convex surface, as shown in FIG. The first microlens 1 a is disposed on a microlens pedestal portion 1 b that is integrally formed with the first microlens substrate 1. Here, the term “integral” as used in this specification means that separate members are not joined or the like, but the same material is continuous. Further, the microlens pedestal portion 1b has the same shape as the outline of the microlens 1a.

  The second microlens substrate 4 mounted independently is a substrate on which a plano-convex cylindrical lens is formed, although not shown in FIG. The second microlens substrate 4 is disposed between the first microlens 1a and the laser diode substrate 2, and collimates the light spread in the fast axis direction from the laser diode to produce the first microlens. It has a function to enter 1a. The light from the laser diode is further collimated by the first microlens 1a with the spread light in the slow axis direction and emitted from the first microlens 1a. Although not shown, the collimated light is incident on a polygon mirror or the like, and can be applied as an apparatus for measuring the distance to an object by scanning a laser beam.

  In the present embodiment, the first microlens substrate 1 is made of, for example, silicon, and the first microlens 1a is made of, for example, a silicon oxide film. Further, as shown in FIG. 3, the first microlens 1a has a vertical thickness (height) 24 of 10 μm or more, specifically about 100 μm. The horizontal width 25 of the first microlens 1a is about 500 μm.

  In addition to the first microlens 1a, a positioning structure 1c is formed on the first microlens substrate 1. The positioning structure portion 1c is formed on the surface of the first microlens substrate 1 on the side where the first microlens 1a is formed. The positioning structure 1 c is also integrated with the first microlens substrate 1. Further, the positioning structure portion 1c is disposed in a region of the first microlens substrate 1 outside the first microlens 1a.

  In the present embodiment, as shown in FIG. 3, positioning structure portions 1c are arranged at both ends of the first microlens 1a. The positioning structure portion 1c has reference surfaces 23a and 23b for aligning the first microlens 1a with the laser diode substrate 2 and the second microlens 4 with the laser diode substrate 2. The reference surfaces 23a and 23b are parallel to the incident surface 21 of the microlens 1a. The second microlens is in contact with the reference surface 23b.

  In the laser diode substrate 2, the light emitting surface 2a of the laser diode substrate 2 and the incident surface 21 of the first microlens 1a face each other through the positioning structure 1c, and the laser diode of the laser diode substrate 2 is the first micro diode. It is combined with the lens 1a.

  Specifically, the laser diode substrate 2 is mounted on the surface of the first microlens substrate 1 on the side where the first microlenses 1a are formed via the submount material 7. Of the side surfaces of the laser diode substrate 2, a part of the side surface that is the light emitting surface 2a is in contact with the side surface of the positioning structure portion 1c that is the reference surface 23a.

  In the present embodiment, as shown in FIG. 3, the vertical thickness (height) 26 of the alignment structure portion 1 c on the surface of the first microlens substrate 1 is the first microlens. This is the same as the sum of the height of 1a and the height of the microlens base 1b. The horizontal width 27 of the positioning structure portion 1c is about 500 μm as long as the laser diode substrate 2 can be held in contact with the reference plane.

  The distance 28a in the optical axis direction between the reference surface 23a of the positioning structure portion 1c and the incident surface 21 of the first microlens 1a collimates the laser light from the light emitting surface 2a of the laser diode substrate 2. It is set so that the first microlens 1a is placed at a position where it can be Further, the thickness of the laser diode substrate 2 and the thickness of the submount material 7 are set so that the heights of the optical axes of the first microlens 1a and the light emitting surface 2a of the laser 2 coincide.

  Further, an interval 28b between the reference surface 23b that is in contact with the second microlens substrate 4 and the reference surface 23a that is in contact with the laser diode substrate 2 is such that the second microlens substrate 4 and the laser diode substrate 2 And the distance between the second microlens substrate 4 and the first microlens 1a are set to have a predetermined size.

  The submount material 7 is made of the same material as that of the laser diode substrate 2 in order to reduce the residual stress of the laser diode substrate. A submount material 7 made of a material different from that of the laser diode substrate 2 can also be used. Then, as shown in FIG. 3, the submount material 7 and the first microlens substrate 1 are bonded by a first bonding material 8. Further, the submount material 7 and the laser diode substrate 2 are joined by a second joining material 9.

  Thus, in the semiconductor optical device of this embodiment, the light emitted from the laser diode of the laser diode substrate 2 is collimated by the first microlens 1a.

  In the present embodiment, the submount material 7 is disposed between the laser diode substrate 2 and the first microlens substrate 1b. However, when the laser diode substrate 2 is manufactured, the thickness of the laser diode substrate 2 is increased. Even if the submount material 7 is not provided, the optical axis can be matched with the thickness of the laser diode substrate 2 and the submount material 7 can be omitted.

  The heat sink 6 is bonded to the laser diode substrate 2 by a third bonding material 10. The heat sink 6 is made of a material having a high thermal conductivity such as Cu, CuW, CuMo, Mo, WC or the like, for example, in order to release heat generated when the laser diode substrate 2 emits light. Further, as shown in FIG. 3, the heat sink material 7 is formed with a potential extraction pad 11 for driving the laser diode. The potential extraction pad 11 and the surface of the laser substrate 2 are electrically connected by a wiring wire 12.

  The optical waveguide 3 is formed on the microlens substrate 1 and is disposed so as to correspond to the first microlens 1a on a one-to-one basis, and the first microlens 1a and the optical waveguide 3 are coupled to each other. As shown in FIG. 2, the optical waveguide 3 is formed on an optical waveguide pedestal 1d integrally formed with the first microlens substrate 1, and in order from the lower side, the first silicon oxide film 13, A second silicon oxide film 14 and a third silicon oxide film 15 containing a concentration of impurities are formed. The optical waveguide 3 is bonded to the heat sink 6 by a fourth bonding material 17.

  1 to 3, the number of the first microlenses 1 a is one, but a plurality of the first microlenses 1 a may be used. In this case, the number of laser diodes can be the same as that of the first microlens 1a, and a plurality of first microlenses 1a can be provided to improve laser output for distance measurement.

  Next, a method for manufacturing the semiconductor optical device in the present embodiment will be described. Below, the case where the number of the 1st micro lens 1a is two is demonstrated. 4 to 8 show a manufacturing process of the semiconductor optical device. 4 to 6, the number of the first microlenses 1 a is one for convenience.

  First, in the step shown in FIG. 4, the first microlens 1 a, the optical waveguide 3, and the positioning structure portion 1 c are formed on the first microlens substrate 1. Specifically, for example, the steps shown in FIGS. 9 to 11 are performed. 9 and 10, FIG. 9A shows a top view of the substrate, and FIG. 9B shows a cross-sectional view along the line CC ′ of the semiconductor substrate in FIG. c) shows a cross-sectional view taken along the line DD ′ of the semiconductor substrate in FIG. FIG. 11 shows a top view of the substrate.

  In the step shown in FIG. 9, although not shown, a silicon wafer to be the first microlens substrate 1 is prepared, and an oxide film is formed on the first microlens substrate 1. Thereafter, this oxide film is patterned. Then, using the patterned oxide film as a mask, as shown in FIGS. 9A and 9B, the formation planned region 30 of the first microlens 1a and the formation planned region 31 of the positioning structure portion 1c are left. Then, the first microlens substrate 1 is etched to form a first trench 32.

  As a result, in the first microlens substrate 1, the formation planned region 30 of the first microlens 1 a is processed into the same shape as the outline of the first microlens 1 a, and at the same time, The positioning structure 1c is formed. This step corresponds to the first step of the present invention.

  At this time, as shown in FIGS. 9A and 9B, a large number of second trenches 33 each having a constant width are arranged in parallel at a predetermined interval in the formation planned region 30 of the first microlens 1a. . As shown in FIG. 9A, the opening shape of the plurality of second trenches 33 is a shape extending in the same direction and in a state parallel to the optical axis.

  Specifically, the ratio of the trench width (hereinafter referred to as the extraction width) 34 and the silicon width (hereinafter referred to as the remaining width) 35 located between the trenches and serving as the sidewall is 0.55: 0. The width of the opening of the mask and the interval between the openings are adjusted so as to be 45. For example, if the extraction width 34 is 1.1 μm, the remaining width 35 is 0.9 μm, and if the extraction width is 2.2 μm, the remaining width is 1.8 μm. Note that the portion left unetched below the second trench 33 becomes the microlens pedestal portion 1b.

  As described above, when the first trench 32 and the second trench 33 are formed in the first microlens substrate 1, the microlens pedestal portion 1b having the contour shape of the first microlens 1a is formed. At the same time, the positioning structure 1c is formed.

  Note that the height of the optical axis of the first microlens 1a on the first microlens substrate 1 is determined by the height of the microlens base 1b. In addition, since the height of the microlens pedestal portion 1b is determined by the depth of the second trench 33, the height of the optical axis of the first microlens 1a is determined by the depth of the second trench 33. For this reason, when forming the second trench 33, the depth of the second trench 33 is set so that the optical axis of the first microlens 1a coincides with the optical axis of the laser diode substrate 2.

  Further, when forming the positioning structure portion 1c, the reference surfaces 23a and 23b of the positioning structure portion 1c are parallel to the light emitting surface 2a of the laser diode substrate 2 mounted on the first microlens substrate 1 in a later step. Thus, the positioning structure 1c is formed. In the present embodiment, the positioning structure portion 1c is formed so that the reference surface 23a is parallel to the incident surface of the first microlens 1a. In this later step, the light emitting surface 2a of the laser diode substrate 2 and the incident surface 21 of the first microlens 1a face each other in parallel, and the laser diode substrate 2 and the first microlens 1a are coupled. Because.

  Further, when forming the positioning structure 1c, as shown in FIG. 3, the reference surface 23a of the positioning structure 1c and the incident surface 21 of the first microlens 1a are not located on the same plane, The position of the reference surface 23a is set so that the positions of these surfaces are shifted. That is, the position of the reference surface 23a is set so that the reference surface 23a is positioned closer to the laser diode substrate 2 than the incident surface 21 of the first microlens 1a.

  Specifically, the position of the reference surface 23a of the positioning structure 1c with respect to the first microlens 1a is a position that takes into account the focal length of the first microlens 1a so that the light from the laser diode can be collimated. Set as follows. For example, assuming that the semiconductor laser is used for collimation, when the laser divergence angle is 90 °, the distance 28 between the light emitting end of the semiconductor laser and the first microlens 1a is, for example, about 1000 μm. That is, when the incident surface 21 of the first microlens 1a is brought close to about 1000 μm to the light emitting end of the semiconductor laser, the side surface 2a of the laser diode substrate 2 and the reference surface 23a of the positioning structure portion 1c come into contact with each other. Thus, the positioning structure 1c is formed.

  The reference surface 23b for contacting the second microlens substrate 4 is positioned between the reference surface 23a for contacting the laser diode substrate 2 and the first microlens 1a. The position of 23b is set.

  Further, as shown in FIGS. 9A and 9C, in the process shown in FIG. 9, the first microlens 1a is formed by forming the first trench 32 in the first microlens substrate 1. The planned region 30 is processed into the contour shape of the first microlens 1a, and the positioning structure 1c is formed. At the same time, the planned region 40 of the optical waveguide 3 in the first microlens substrate 1 is formed into the optical waveguide. 3 contour shape. Note that the second trench 33 is also formed in the planned formation region 40 of the optical waveguide 3 in the same manner as the planned formation region 30 of the first microlens 1a. Thereby, the optical waveguide pedestal portion 1 d having the same contour shape as that of the optical waveguide 3 is formed in the planned formation region 40 of the optical waveguide 3.

  The flatness of the side wall surface of the first trench 32 after etching, particularly the side wall surface that defines the outermost peripheral portion of the region 30 where the first microlens 1a is to be formed, is a surface 21 on which this surface is incident or output of light. 22 is important. For this reason, after etching the first microlens substrate 1, although not shown, the entire substrate 1 is annealed in a hydrogen atmosphere to reduce the surface roughness on the trench sidewalls. Thereafter, a lens surface having a smooth surface can be obtained by performing so-called sacrificial oxidation. This technique is disclosed in Japanese Patent Application Laid-Open No. 2002-231945. Further, the oxide film mask used in the etching is removed by immersion in a hydrofluoric acid solution.

  Subsequently, in the step shown in FIG. 10, the first microlens 1 a is formed in the formation planned region 30 of the first microlens 1 a, and the optical waveguide 3 is formed in the formation planned region 40 of the optical waveguide 3. To do. More specifically, the inside of the second trench 33 is filled with the silicon oxide 37 by thermal oxidation, and the trench side wall portion 36 which is a silicon layer between the second trenches 33 is replaced with the silicon oxide 37. In this way, the first microlens 1a integrated with the first microlens substrate 1 is formed. This step corresponds to the second step of the present invention.

  At this time, the thickness of the oxide film 37 is set equal to or more than the sum of the blank width 34 and the remaining width 35. Usually, the thermal oxide film proceeds at a ratio of 0.45: 0.55 on the inside and outside of the silicon surface. In this embodiment, the extraction width 34 and the remaining width 35 are set in accordance with this ratio, that is, the second trench 33 is filled with silicon oxide in the thermal oxidation, and at the same time, the silicon layer 36 between the trenches. Is a dimension that becomes silicon oxide.

Therefore, when the entire interior of the second trench 33 is filled with the thermal oxide film, the silicon layer 36 between the trenches is all oxidized. That is, as shown in FIG. 10A, at this point, the entire formation region 30 of the first microlens 1a becomes a lump of silicon oxide (SiO ₂ ) 37, and the first microlens 1a is formed. At this time, an oxide film 38 is formed from the side wall surface constituting the first trench 32 to the surface of the positioning structure portion 1c. That is, the positioning structure 1c is formed simultaneously with the formation of the first microlens 1a.

  In addition, after this thermal oxidation process, in order to improve the light transmittance of the first microlens 1a, an antireflection film can be coated on the entire substrate as necessary.

  Further, in the planned formation region 40 of the optical waveguide 3, as in the planned formation region 30 of the first microlens 1 a, the silicon oxide 37 is formed in the second trench 33 by thermal oxidation in the step shown in FIG. 10. In addition, the silicon layer 36 between the second trenches 33 is replaced with a silicon oxide 37. Thus, in the present embodiment, a silicon oxide layer is formed on the optical waveguide pedestal portion 1d simultaneously with the formation of the first microlens 1a.

  Further, by implanting impurities into this silicon oxide layer, as shown in FIGS. 10B and 10C, the first silicon oxide film 13, the second silicon oxide film 14, and the third silicon oxide film are formed. The first microlens 1 a and the optical waveguide 3 constituted by the film 15 are formed.

  In the present embodiment, the case where the first microlens 1a and the optical waveguide 3 are formed on the same semiconductor substrate 1 has been described. However, the optical waveguide 3 and the first microlens 1a are formed on different semiconductor substrates. They can be formed and joined together.

  Next, in the process shown in FIG. 11, an Au / Ti film 42 is applied only to the mounting region 41 of the laser diode substrate 2 on the surface of the wafer 1 on which the first microlens 1a is formed using a metal mask. Form a film. In FIG. 11, the optical waveguide 3 is omitted.

  Here, Ti in the Au / Ti film 42 is for improving the adhesion between the oxide film 38 on the surface of the first microlens substrate 1 and Au, and the Au in the Au / Ti film 42 is sublimated in advance. This is for eutectic bonding with AuSn eutectic solder formed on the back surface of the mounting material 7 and for connection with Au wiring in a later step.

  Thereafter, the wafer 1 on which the first microlenses 1a are formed is diced. Dicing cut is performed on a region not shown. Thereby, the wafer 1 is set to a desired size. At the time of dicing cutting, since Si chips adhere to the surface of the first microlens, a protective film such as a resist is applied to the surface of the wafer and cut. Alternatively, half-cut from the wafer back surface and cleave. As a result, the microlens can be formed into a chip shape without fouling.

  In this way, as shown in FIG. 4, the microlens 1 a and the positioning structure portion 1 c are formed on the first microlens substrate 1. 4A is a cross-sectional view taken along the line E-E ′ in FIG. 11, and FIG. 4B is a cross-sectional view taken along the line F-F ′ in FIG. 11. FIG. 4C is a perspective view of a portion where the first microlens 1a and the positioning structure 1c are formed.

  Next, in the step shown in FIG. 5, as shown in FIGS. 5A, 5B, and 5C, the second microlens substrate 4 is brought into contact with the reference surface 23b, so that the first microlens. Mounted on the substrate 1. Then, the submount material 7 is mounted on the microlens substrate 1 in contact with the reference surface 23a of the positioning structure 1c. The submount material 7 is for making the optical axis of the laser diode coincide with the optical axis of the first microlens 1a. Note that bonding materials 43 and 44 such as a eutectic alloy layer made of Au and Sn are formed on the front and back surfaces of the submount material 7 in advance. The bonding material 43 on the back surface side of the submount material 7 and the Au / Ti film 42 in these bonding materials 43 and 44 are the first bonding material 8.

  Subsequently, in the step shown in FIG. 6, as shown in FIGS. 6A, 6B, and 6C, the side surface 2a of the laser diode substrate 2 is brought into contact with the reference surface 23a of the positioning structure portion 1c. Mount on the submount 7. Thereby, a necessary distance between the light emitting surface 2a of the laser diode and the first microlens 1a is secured. In this way, the light emitting surface 2a of the laser diode substrate 2 and the incident surface 21 of the first microlens 1a face each other, and the laser diode substrate 2 and the first microlens 1a are coupled.

  This step corresponds to the third step of the present invention. Further, Au films 45 and 46 are formed in advance on the front and back surfaces of the laser diode substrate 2. The Au film 45 on the back side of the laser diode substrate 2 in these Au films 45 and 46 and the bonding material 44 on the front surface side of the submount material 7 are the second bonding material 9.

  The position of the optical axis of the laser diode substrate 2 can be adjusted by the thickness of the laser diode substrate 2. Therefore, in order to make the optical axis of the first microlens 1a coincide with the optical axis of the laser diode substrate 2, a laser diode substrate 2 having a predetermined thickness is prepared.

  Thereafter, the laser diode substrate 2, the submount material 7, and the first microlens substrate 1 are bonded by heating and pressing. At this time, heating is performed at a temperature equal to or higher than the eutectic point of the Au—Sn eutectic alloy, for example, about 300 ° C. Here, the Au—Sn eutectic alloy is used as the bonding material. However, the present invention is not limited to this. For example, an Au—Si eutectic alloy, an alloy layer made of Au and Ge, or SnPb solder can also be used.

  Next, in the step shown in FIG. 7, the substrate 1 shown in FIG. 6 is turned upside down, and the heat sink material 6 for radiating the heat at the time of laser diode emission is passed through In serving as the third bonding material 10. And thermocompression. FIG. 7 shows the same cross section as FIG. In is formed in advance by mask vapor deposition or the like only in the bonding region of the heat sink material 6. Further, an insulating film 11a such as polyimide and an Au film 11b are sequentially formed on the surface of the heat sink material 6 in advance as a potential extraction pad 11 before bonding.

  In addition to In, for example, an Au—Si eutectic alloy, an eutectic alloy composed of Au and Sn, an alloy layer composed of Au and Ge, or SnPb solder can be used as the third bonding material 10.

  At this time, the second microlens substrate 4 is fixed by being sandwiched between the heat sink 6 and the microlens substrate 1.

  Subsequently, in the step shown in FIG. 8, wire bonding is performed, and the potential extraction pad 11 formed on the laser diode substrate 2 and the heat sink 6 is electrically connected by the wiring wire 12. As the wiring wire 12, as shown in FIG. 8B, for example, a wide Au ribbon can be used. The purpose of using a wide Au ribbon is to dissipate heat when the laser diode emits light. Note that the bonding position of the Au ribbon and the number of Au ribbons can be changed according to the characteristics of the disk.

  The semiconductor optical device shown in FIGS. 1, 2, and 3 can be manufactured as described above.

  In the present embodiment, in the process shown in FIG. 9, the first microlens substrate 1 is to be formed once by performing etching once on the first microlens substrate 1. Is processed into the shape of the first microlens 1a, and at the same time, the positioning structure 1c is formed. And the 1st micro lens 1a is formed in the formation plan area 30 of the 1st micro lens 1a.

  For this reason, the relative positions of the first microlens 1a and the positioning structure portion 1c are determined only by the accuracy of etching. Thereby, compared with the case where the 1st micro lens and the positioning structure part are formed separately, the positioning of the 1st micro lens 1a and the positioning structure part 1c can be performed with high accuracy.

  Further, the position of the reference surface 23a of the positioning structure portion 1c is set so as to ensure a necessary distance between the incident surface 21 of the first microlens 1a and the light emitting surface 2a of the laser diode substrate 2. . Then, in the step shown in FIG. 6, a part of the side surface of the laser diode substrate 2 that becomes the light emitting surface 2a is brought into contact with the reference surface 23a of the positioning structure portion 1c, so that the first microlens substrate 1 is formed. The laser diode substrate 2 is mounted on the.

  Accordingly, the distance between the light emitting surface 2a of the laser diode substrate 2 and the incident surface 21 of the first microlens 1a can be set to a predetermined size. That is, the positioning accuracy between the first microlens 1a and the laser diode substrate 2 can be improved as compared with the prior art, and the optical coupling efficiency between the first microlens 1a and the laser diode substrate 2 can be improved as compared with the prior art. be able to.

  In addition, the second microlens substrate 4 is mounted on the first microlens substrate 1 in contact with the reference surface 23b of the positioning structure 1c. Thus, the distance between the light emitting surface 2a of the laser diode substrate 2 and the second microlens substrate 4 and the distance between the second microlens substrate 4 and the first microlens 1a are easily set to a desired size. be able to.

  Furthermore, in this embodiment, in the step shown in FIG. 9, the formation planned region 40 of the optical waveguide 3 is processed into the shape of the optical waveguide 3 simultaneously with the processing of the formation planned region 30 of the first microlens 1 a. Then, the optical waveguide 3 is formed in a region 40 where the optical waveguide 3 is to be formed.

  Therefore, the relative position between the first microlens 1a and the optical waveguide 3 is also determined only by the etching accuracy. Thereby, compared with the case where the 1st micro lens 1a and the optical waveguide 3 are formed in a different semiconductor substrate, the positioning of the 1st micro lens 1a and the optical waveguide 3 can be performed with high precision.

  In addition, as described in the background section above, when a lens is manufactured by depositing an oxide film on a semiconductor substrate by a sputtering method, it is difficult to set the height of the lens to 5 μm or more by the sputtering method. . Further, even if an oxide film having a thickness of, for example, about 10 μm can be formed by the technique described in the above background art section, this technique forms an oxide film on the entire surface of the substrate. It is expected that the substrate warps due to the difference in thermal expansion coefficient between the silicon and the oxide film. For this reason, there is a possibility that a problem that the wafer breaks during wafer chucking in the etching process frequently occurs.

  On the other hand, in the present embodiment, in the step shown in FIG. 9, in the first microlens substrate 1, the formation planned region 30 of the first microlens 1 a is set as the contour shape of the first microlens 1 a. At the same time, a plurality of second trenches 33 are formed in the formation planned region 30 of the first microlens 1a. Then, in the step shown in FIG. 10, the microlens pedestal portion is formed by filling the second trench 33 with the oxide film 37 by thermal oxidation and replacing the silicon layer 36 between the second trenches 33 with the oxide film 37. A first microlens 1a is formed on 1b.

  Since the first microlens 1a is formed by such a method, in this embodiment, it is easy to form the first microlens 1a having a height 24 of 5 μm or more. In addition, since a thick oxide film is formed only in the formation region 30 of the first microlens 1a, the first microlens 1a having a height 24 of 5 μm or more is formed even if the first microlens 1a is formed. It is possible to suppress warping of the lens substrate 1.

  In the prior art described in the background section above, the relative position between the laser diode substrate and the microlens is fixed by hooking and fixing the laser diode substrate to the step between the microlens installation surface and the guide groove. It was decided. On the other hand, in the above-described prior art, after forming a microlens on a substrate, a guide groove is formed on the same substrate by photolithography and etching techniques. Therefore, the unevenness of the substrate has poor photoresist coverage, and exposure becomes difficult if the photoresist is thickened to avoid it.

  For this reason, in the prior art described in the background section above, it is difficult to form a deep guide groove of about 100 μm, for example, and the step between the microlens installation surface and the guide groove is small. For this reason, there is a possibility that the laser diode substrate cannot be sufficiently fixed by being caught on the step.

  On the other hand, in the present embodiment, in the step shown in FIG. 9, photolithography and etching are performed before the uneven portion exists in the first microlens substrate 1, and the first microlens substrate 1 is subjected to the first process. By forming the trench 32, the positioning structure portion 1c is formed.

  For this reason, the 1st trench 32 deeper than the guide groove in the said prior art can be formed. Thereby, the height 26 (refer FIG. 3) on the 1st micro lens board | substrate 1 of the structure part 1c for positioning can be made larger than the level | step difference of the said prior art. As a result, when the laser diode substrate 2 is mounted on the microlens substrate 1 by bringing the laser diode substrate 2 into contact with the reference surface 23a of the positioning structure portion 1c, the laser diode substrate 2 is sufficiently hooked on the positioning structure portion 1c. Can be fixed to.

  In the above-described prior art, all of the side surfaces of the laser diode substrate that serve as the light emitting surface are brought into contact with the step between the microlens installation surface and the guide groove. In this case, there is a problem that the relative position between the laser diode and the microlens is shifted if a foreign substance enters somewhere between the side surface that becomes the light emitting surface of the laser diode substrate and the step.

  On the other hand, in this embodiment, as shown in FIGS. 3 and 6, the portion corresponding to the positioning structure portion 1c among the side surfaces to be the light emitting surface 2a of the laser diode substrate 2 is defined as the positioning structure portion 1c. In contact with the reference surface 23a. As described above, in the present embodiment, only the minimum necessary region of the side surface to be the light emitting surface 2a of the laser diode substrate 2 is brought into contact with the reference surface 23 of the positioning structure portion 1c.

  As a result, the relative position shift between the laser diode substrate 2 and the microlens 1a due to the foreign matter occurs as compared with the case where all of the light emitting surface 2a of the laser diode substrate 2 is in contact with the positioning structure portion 1c. Can be suppressed.

Further, in the above-described prior art, a microlens made of a SiO ₂ film is formed directly on a semiconductor substrate without providing a pedestal portion. In this case, a corner formed by the side surface of the microlens and the semiconductor substrate exists at the interface between the semiconductor substrate and the microlens. For this reason, stress is concentrated at the corner due to the difference in thermal expansion coefficient between the semiconductor substrate and the microlens. This was a cause of reducing the reliability with respect to the strength of the microlens.

  In contrast, in the present embodiment, the shape of the microlens pedestal portion 1b is the same as that of the first microlens 1a. That is, the side surface of the microlens pedestal portion 1b and the side surface of the first microlens 1a are matched.

  Thereby, a corner | angular part can be made not to exist in the interface of the micro lens base part 1b and the 1st micro lens 1a. Further, in the present embodiment, a corner portion formed by the side surface of the microlens pedestal portion 1 b and the upper surface of the first microlens substrate 1 exists at the interface between the microlens pedestal portion 1 b and the first microlens substrate 1. .

  As described above, in the present embodiment, the structure of the semiconductor optical device is a structure in which corners are present at the interface between the microlens pedestal 1b and the first microlens substrate 1 that are separated from the first microlens 1a. Therefore, the reliability with respect to the strength of the first microlens 1a can be improved.

  In the present embodiment, when a temperature change occurs in the semiconductor optical device, a stress is generated at the interface between the microlens pedestal portion 1b and the first microlens 1a due to the difference in thermal expansion coefficient, but the microlens pedestal portion 1b. This stress is relieved by deforming. From this, it can be said that the reliability of the strength of the first microlens 1a is improved.

  When the shape of the microlens pedestal portion 1b is larger than that of the first microlens 1a, the upper surface of the microlens pedestal portion 1b and the first microlens pedestal 1b are formed at the interface between the first microlens 1a and the microlens pedestal portion 1b. There is a corner formed by the side surface of the lens 1a. For this reason, the presence of the microlens pedestal portion 1b is not sufficient for improving the reliability of the first microlens 1a.

  In addition, as in the present embodiment, the distance between the first microlens 1a and the light emitting surface 2a of the laser diode substrate 2 is obtained by making the shape of the microlens pedestal portion 1b the same as that of the first microlens 1a. Can be set arbitrarily. That is, according to the present embodiment, when the performance of the first microlens 1 a and the laser diode substrate 2, for example, the focal length of the first microlens 1 a is short, the first microlens 1 a and the laser diode substrate 2 It becomes easy to set the distance from the light emitting surface 2a small.

(Second Embodiment)
FIG. 12 shows a part of the semiconductor optical device according to this embodiment. FIG. 12 is a cross-sectional view corresponding to FIG. 2, and the optical waveguide 3 is omitted in FIG. Of the structural parts of the semiconductor optical device shown in FIG. 12, the same structural parts as those of the semiconductor optical device shown in FIG.

  In the semiconductor optical device according to the first embodiment, as shown in FIG. 2, the second microlens substrate 4 is inserted between the first microlens 1 a and the laser diode substrate 2. The semiconductor optical device according to the present embodiment is a structural example in which the second microlens 1a is disposed on the opposite side of the laser diode substrate 2 with respect to the optical axis direction. A lens base substrate 52 having a partition 51 is bonded to the heat sink 6, and the lens 4 is bonded to the partition 51.

  The semiconductor optical device of this embodiment can be manufactured by the same manufacturing process as that of the first embodiment, except for a part. 7 differs from the manufacturing process of the first embodiment in the process shown in FIG. 7 in that, for example, a heat sink 6 in which a lens base substrate 52 is bonded by eutectic solder is prepared, and the lens 4 is attached to a partition 51 with an epoxy resin. It is the point which joins with the UV curable adhesive etc. which have as a main component.

  The distance between the lens 4 and the laser diode light emitting surface 2a is adjusted by the thickness 51a of the partition 51 of the lens base substrate 52 that holds the lens. When the positional accuracy is required, the partitioning side surface is positioned in contact with the surface 53 on the opposite side of the reference surface 23a among the side surfaces of the alignment structure portion 1c. Further, the fixing of the lens base substrate 52 and the heat sink material 6 is not limited to the method using eutectic solder, but can be joined by other methods. For example, when the bonding temperature affects other materials or a problem arises in the bonding strength, the lens base substrate and the heat sink can be integrated by silver brazing.

  Even if the semiconductor optical device is manufactured as in the present embodiment, the same effect as in the first embodiment is obtained.

(Third embodiment)
In the first and second embodiments, the case where the first microlens 1a is used as the first optical component has been described as an example. However, in the present embodiment, the optical waveguide 3 is used as the first optical component. Will be explained. Note that the insertion position of the second microlens substrate for collimating the spread of light in the fast axis direction is the same as in the first embodiment.

  FIG. 13 is a sectional view of the semiconductor optical device according to this embodiment. The semiconductor optical device shown in FIG. 13 is different from the semiconductor optical device shown in FIG. 2 in that it does not have the first microlens 1a, and the other structural parts are the same as those in FIG. A part of the description is omitted by giving the same reference numerals.

  This semiconductor optical device includes an optical waveguide 3, a laser diode substrate 2 as a second optical component, and a heat sink 6.

  As in the first embodiment, the optical waveguide 3 is formed integrally with the semiconductor substrate 1, and the positioning structure portion 1 c is also formed integrally with the semiconductor substrate 1 on the semiconductor substrate 1. The laser diode substrate 2 is mounted on the semiconductor substrate 1 with the side surface 2a serving as the light emitting surface of the laser diode substrate 2 in contact with the reference surface 23a of the positioning structure portion 1c.

  Next, a method for manufacturing the semiconductor optical device of this embodiment will be described. Here, the process of forming the optical waveguide 3 and the positioning structure 1c will be mainly described. 14, 15 (a) and 14 (b) show a part of the manufacturing process of the semiconductor optical device. 14 is a top view of the semiconductor substrate, and FIGS. 15A and 15B are a G-G ′ sectional view and a H-H ′ sectional view in FIG. 14, respectively. Note that, in these drawings, the same reference numerals as those in FIGS. 9 and 10 are given to the same structural portions as those in FIGS. 9 and 10.

  In the step shown in FIG. 14, the semiconductor substrate 1 is prepared, and the semiconductor substrate 1 is etched in the same manner as in the step shown in FIG. Note that this step is different from FIG. 9 in that the planned formation region 30 of the microlens 1 a in FIG. 9 is replaced with the planned formation region 40 of the optical waveguide 3.

  Specifically, by forming the first trench 32 in the semiconductor substrate 1, the formation planned region 40 of the optical waveguide 3 in the semiconductor substrate 1 is processed into the outline shape of the optical waveguide 3, and at the same time, The positioning structure 1c is formed. At this time, the second trench 33 is formed in the region 40 in which the optical waveguide 3 is to be formed, as in the step shown in FIG.

  Thus, by forming the first trench 32 and the second trench 33 in the semiconductor substrate 1, the optical waveguide pedestal portion 1d having the same shape as the contour of the optical waveguide 3 is formed, and at the same time, for positioning The structure part 1c is formed.

  Next, in the step shown in FIG. 15, as in the step shown in FIG. 10, the second trench 33 is filled with silicon oxide in the region 40 where the optical waveguide 3 is to be formed by thermal oxidation. The silicon layer 36 between the trenches 33 is replaced with silicon oxide. As a result, a silicon oxide layer is formed on the optical waveguide pedestal 1d. Further, by injecting impurities into this silicon oxide layer, the optical waveguide 3 composed of the first silicon oxide film 13, the second silicon oxide film 14, and the third silicon oxide film 15 is formed.

  Thereafter, although not shown, the second microlens substrate 4 is mounted on the semiconductor substrate while being in contact with the positioning structure portion 1c, as in the first embodiment. Further, the submount material 7 and the laser diode substrate 2 are mounted on the semiconductor substrate 1, and the laser diode substrate 2 and the optical waveguide 3 are coupled. Then, the laser diode substrate 2 and the optical waveguide 3 and the heat sink 6 are joined while the second microlens substrate 4 is sandwiched between the semiconductor substrate 1 and the heat sink 6. In this way, the semiconductor optical device shown in FIG. 13 can be manufactured.

  Also in this embodiment, by performing etching once on the semiconductor substrate 1, the formation planned region 40 of the optical waveguide 3 of the semiconductor substrate 1 is processed into the shape of the optical waveguide 3, and at the same time, the positioning structure portion 1 c is formed. Forming. And the optical waveguide 3 is formed on the optical waveguide base part 1d.

  For this reason, the relative position between the optical waveguide 3 and the positioning structure portion 1c is determined only by the accuracy of etching. Thereby, compared with the case where an optical waveguide and a positioning structure part are formed separately, the optical waveguide 3 and the positioning structure part 1c can be positioned with high accuracy.

  Also in this embodiment, as in the first embodiment, the laser diode substrate 2 is mounted on the semiconductor substrate 1 so that the laser diode substrate 2 is brought into contact with the reference surface 23a of the positioning structure portion 1c. Therefore, the positioning accuracy between the optical waveguide 3 and the laser diode substrate 2 can be improved as compared with the conventional technique, and the optical coupling efficiency between the optical waveguide 3 and the laser diode substrate 2 can be improved as compared with the conventional technique.

  Further, according to the present embodiment, compared with the first embodiment, since the number of parts can be reduced by the amount of the first microlens 1a being omitted, a semiconductor optical device can be manufactured at a low cost.

  Also in this embodiment, the optical waveguide pedestal portion 1 d has the same shape as the contour of the optical waveguide 3, similarly to the microlens pedestal portion 1 b in the first embodiment. Thereby, the reliability with respect to the intensity | strength of the optical waveguide 3 can be improved.

(Other embodiments)
(1) In the first to third embodiments, a region where the optical waveguide 3 is to be formed is processed into the shape of the optical waveguide 3 in the substrate 1, an oxide film is formed in the region, and then an impurity is injected into the region Thus, the optical waveguide 3 is formed, but the optical waveguide 3 can be formed by other methods.

  For example, the optical waveguide 3 can be formed as follows. FIG. 16 shows a manufacturing process of the optical waveguide 3. As shown in FIG. 16A, a silicon substrate 61 is prepared. Subsequently, as shown in FIG. 16B, a silicon layer 62 containing a high concentration impurity is formed on the surface of the silicon substrate 61 by an epitaxial growth method. Further, as shown in FIG. 16C, a non-doped silicon layer 63 containing no impurities is formed on the silicon layer 62 by an epitaxial growth method. In this way, the substrate 1 having the silicon layer 62 containing high concentration impurities is formed.

Subsequently, as shown in FIG. 16D, in the step shown in FIG. 9 of the first and second embodiments and the step shown in FIG. 14 of the third embodiment, the first trench 32 and the second trench 33 are formed. Form.
Then, the optical waveguide 3 can be formed by performing thermal oxidation similarly to the process shown in FIG. 10 and the process shown in FIG.

  (2) In each of the embodiments described above, the case where the first microlens 1a is formed by the steps shown in FIGS. 9 and 10 has been described. However, the first microlens 1a may be formed by other methods. it can. For example, in the process shown in FIG. 9, the second trench 33 is not formed in the formation region 30 of the first microlens 1a, and the formation region 30 of the first microlens 1a is changed to the first microlens. Process into the shape of 1a. Then, the 1st micro lens 1a can also be formed by apply | coating a glass film on the formation plan area | region 30 of the 1st micro lens 1a by SOG (Spin-On Glass).

  (3) In each of the above-described embodiments, as shown in FIG. 3, the laser diode substrate 2 and the heat sink 6 are connected by the third bonding material 10, but the laser diode substrate 2 emits light at a low output. If the deterioration of the characteristics does not occur even if a silicon substrate is inserted between the heat sink 6 and the heat sink 6, the structure shown in FIG.

  FIG. 17 shows a part of a semiconductor optical device according to another embodiment. In FIG. 17, the same reference numerals are assigned to the same structural portions as those in FIG. 3 among the structural portions of the semiconductor optical device. In the semiconductor optical device shown in FIG. 17, after the laser diode substrate 2 is mounted on the first microlens substrate 1 on which the first microlens 1 a is formed, the first microlens substrate is formed by the third bonding material 10. 1 is joined to the heat sink 6.

  (4) The semiconductor optical device may have a structure shown in FIG. In the semiconductor optical device shown in FIG. 18, a part where the microlens substrate 1 and the laser diode substrate 2 shown in FIG. 3 are combined is used as one optical component unit 71, and two optical component units 71 are used. It has a structure.

  Thus, by using two laser diode substrates 2, it is possible to increase the output as compared with the above-described embodiments. As a method for increasing the laser output, it is conceivable to increase the number of light emitting layers in one laser diode substrate 2, but as the laser diode substrate 2 becomes longer, the laser diode substrate 2 warps. It becomes easy and a manufacturing yield will fall. On the other hand, in the semiconductor optical device shown in FIG. 18, since a plurality of laser diode substrates 2 are used, the laser diode substrate 2 need not be lengthened. Thereby, the manufacturing yield due to the warp of the laser diode 2 can be improved.

  (5) In each of the embodiments described above, the case where the laser diode substrate 2 is used has been described as an example. However, a light emitting diode can be used instead of the laser diode.

  (6) In the first and second embodiments, the case where the micro lens 1a is used as the first optical component has been described as an example. However, as the first optical component, an optical element having a function as a prism or a mirror, A polarizing element such as a grating can also be used.

1 is a perspective view of a semiconductor optical device according to a first embodiment. FIG. 2 is a cross-sectional view of the semiconductor optical device taken along the line A-A ′ in FIG. 1. FIG. 3 is a perspective view of a region B in FIG. 2. It is a figure which shows the manufacturing process of the semiconductor optical device in 1st Embodiment. FIG. 5 is a diagram showing manufacturing steps of the semiconductor optical device following FIG. 4. FIG. 6 is a diagram showing manufacturing steps of the semiconductor optical device following FIG. 5. FIG. 7 is a diagram showing manufacturing steps of the semiconductor optical device following FIG. 6. FIG. 8 is a diagram illustrating manufacturing steps of the semiconductor optical device following FIG. 7. 5A and 5B are diagrams for explaining the process shown in FIG. 4 in more detail, wherein FIG. 5A is a top view of the semiconductor substrate, FIG. 5B is a cross-sectional view taken along the line CC ′ of the substrate in FIG. ) Is a cross-sectional view along the line DD ′. FIG. 10 is a diagram illustrating a manufacturing process subsequent to FIG. 9, in which (a) is a top view of the semiconductor substrate, (b) is a cross-sectional view taken along the line CC ′ of the substrate in (a), and (c) is DD. FIG. FIG. 11 shows a manufacturing process following FIG. 10 and is a top view of the semiconductor substrate. It is sectional drawing of the semiconductor optical apparatus in 2nd Embodiment. It is sectional drawing of the semiconductor optical device in 3rd Embodiment. It is a figure which shows the manufacturing process of the semiconductor optical device in 3rd Embodiment. FIG. 15 is a diagram illustrating manufacturing steps subsequent to FIG. 14, in which (a) is a cross-sectional view taken along line G-G ′ of the substrate in FIG. 14, and (b) is a cross-sectional view taken along line H-H ′. It is sectional drawing which shows a part of manufacturing process of the semiconductor optical device in other embodiment. It is sectional drawing of the semiconductor optical device in the 1st example of other embodiment. It is sectional drawing of the semiconductor optical apparatus in the 2nd example of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Micro lens board | substrate (semiconductor substrate), 1a ... 1st micro lens,
1b: Microlens base part, 1c: Positioning structure part, 1d: Optical waveguide base part,
2 ... laser diode substrate, 3 ... optical waveguide, 4 ... second microlens,
6 ... heat sink, 7 ... submount material, 8 ... first bonding material, 9 ... second bonding material,
DESCRIPTION OF SYMBOLS 10 ... 3rd joining material, 11 ... Potential extraction pad, 12 ... Wiring wire, 21 ... Incident surface,
22 ... Outgoing surface, 23 ... Reference surface of positioning structure.

Claims (10)

In the method of manufacturing a semiconductor optical device in which the first optical component ( 1a ) formed on the semiconductor substrate (1) and the second optical component ( 2 ) are coupled,
By etching the semiconductor substrate (1), the formation planned region ( 30 ) of the first optical component in the semiconductor substrate (1) is processed into the contour shape of the first optical component ( 1a ), and at the same time, A first step of forming on the semiconductor substrate (1) a positioning structure (1c) for determining the position of the second optical component ( 2 );
A second step of forming the first optical component ( 1a ) in the formation planned region ( 30 ) of the first optical component;
A third step of mounting the second optical component ( 2 ) on the semiconductor substrate (1) by bringing the second optical component ( 2 ) into contact with the positioning structure (1c). ,
In the first step, a plurality of trenches (33) are formed in a region ( 30 ) where the first optical component is to be formed in the semiconductor substrate (1),
In the second step, the inside of the trench (33) is filled with an oxide (37) of a material constituting the semiconductor substrate (1), and a trench side wall portion (between the trenches (33)) ( 36) replacing the oxide (37) to form the first optical component ( 1a ), a method for manufacturing a semiconductor optical device. In the first step, simultaneously with the processing of the formation planned region (30) of the first optical component (1a), the formation planned region (40) of the third optical component (3) in the semiconductor substrate is formed in the first step. while machining the contour shape of the third optical component (3), also forming a plurality of trenches (33) Oite to the third optical component formation region (40),
In the second step, the inside of the trench (33) is filled with an oxide of a material constituting the semiconductor substrate, and the trench sidewall (36) located between the trenches (33) is oxidized. The method of manufacturing a semiconductor optical device according to claim 1, wherein the third optical component (3) is formed by replacing with an object. In the first step, the first to match the optical axis of the optical component the optical axis of (1a) a second optical component (2), forming region before Symbol first optical component 3. The method of manufacturing a semiconductor optical device according to claim 1, wherein the plurality of trenches (33) having a predetermined depth are formed in ( 30 ). In the first step, a contact surface (23a) with the second optical component ( 2 ) of the positioning structure portion (1c) serves as the second optical component in the first optical component. The positioning structure (1c) is formed so as to be positioned closer to the second optical component ( 2 ) than the opposing surface (21),
Wherein in the third step, the positioning structure by contacting said second optical component (2) to (1c), said first optical component (1a) and said second optical component (2) 4. The method of manufacturing a semiconductor optical device according to claim 1, wherein the distance between the first and second electrodes is set to a predetermined size. 5. In the first step, when the second optical component ( 2 ) is mounted on the semiconductor substrate (1) in the third step, the first optical component in the second optical component ( 2 ). 5. The semiconductor optical according to claim 4, wherein the positioning structure portion (1 c) is arranged so that a part of the surface (2 a) facing the contact portion contacts the positioning structure portion (1 c). Device manufacturing method. The method of manufacturing a semiconductor optical device according to the first optical component is any one of claims 1 to 5, characterized in that a microlens (1a).   3. The method of manufacturing a semiconductor optical device according to claim 2, wherein the first optical component is a microlens (1a) and the third optical component is an optical waveguide (3). The method of manufacturing a semiconductor optical device according to the second optical component according to any one of claim 1 to 7, characterized in that a laser diode (2) or light-emitting diodes. In the third step, the optical axis of the first optical component ( 1a ) and the optical axis of the second optical component ( 2 ) are formed on a substrate having a predetermined thickness to match the optical axis of the second optical component ( 2 ). 9. The semiconductor according to claim 1, wherein a second optical component (2) is prepared, and the second optical component (2) is mounted on the semiconductor substrate (1). Manufacturing method of optical device. In the third step, in order to make the optical axis of the first optical component ( 1a ) coincide with the optical axis of the second optical component (2), a submount material (7) having a predetermined thickness is used. The method for manufacturing a semiconductor optical device according to claim 1, wherein the second optical component (2) is mounted on the semiconductor substrate (1).

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