JP4039367B2 - Manufacturing method of optical element mounting substrate - Google Patents

Description

  The present invention relates to an optical element mounting substrate manufacturing method and an optical element mounting substrate.

  Conventionally, there is an optical element mounting substrate as an optical element mounting substrate on which a ball lens, a cylindrical aspheric lens, and an optical fiber are mounted with high accuracy.

  For example, in Japanese Patent Laid-Open No. 10-149559, an L-shaped submount fused to the surface of a silicon substrate 2 and an adhesive to the silicon substrate and in close contact with two surfaces 31 and 32 of the submount. The form which arrange | positions and positions the polarizing beam splitter 6 arrange | positioned in this way is disclosed.

JP-A-10-149559

  However, there is a concern that the optical element mounting substrate disclosed in the above-mentioned conventional example may prevent stable fixing such as one side being generated due to a manufacturing error of the angle of the two surfaces joined to the prism corner and the submount. Is done.

  The polarizing beam splitter is in close contact with the silicon substrate surface and the two submount side surfaces, and stress is generated from these linear expansion coefficients during operation of the optical element device on which a laser element, an optical component, etc. are mounted. In addition, there is a concern that misalignment or peeling of optical components such as prisms may occur.

  Alternatively, it is preferable to suppress the efficiency of the optical element device when a positional deviation of the beam with respect to the optical component occurs.

  Then, this invention is providing the optical element mounting board | substrate which can contribute to the solution of either of the said subjects.

In order to achieve the above object, the solving means in the present invention is as follows.
The optical element mounting substrate is configured with a multilayer structure. A laminated structure is formed using a large-area substrate, and individual optical element mounting substrates are separated by dicing. As a summary, a through hole is provided in one substrate, and the other substrate surface is used as a mounting surface for optical components. Further, a reference marker is provided on a wafer provided with an optical component mounting positioning marker in advance, and high-precision positioning bonding at the wafer level is performed based on the reference marker. Then, individual mounting boards are cut out and separated. This will be described in detail below.
(1) A method for manufacturing an optical element mounting substrate, comprising: a semiconductor laser element mounting portion; and an optical component mounting portion that optically communicates with the semiconductor laser element and emits laser light to the outside.
Forming a first reference marker and a through hole in the first substrate;
Forming a second reference marker and an optical component mounting marker corresponding to the optical component mounting portion on a second substrate;
The first substrate and the second substrate are joined so that the first reference marker and the second reference marker correspond to each other so that the optical component mounting marker is positioned in the through-hole portion. And a process of
And a step of dicing the bonded substrates to separate the optical device mounting substrate.

More specifically, in the above (1), after the first substrate and the second substrate are bonded, the second substrate is formed on the first substrate based on the first reference marker. Forming a semiconductor laser element mounting marker at a position corresponding to the mounting portion of the semiconductor laser element corresponding to the optical component mounting marker on the substrate.

Alternatively, in (1), a first reference marker and a through hole are formed on the first substrate, and a semiconductor laser element mounting marker is formed at a position corresponding to the mounting portion of the semiconductor laser element based on the first reference marker. The process of carrying out.

  By forming in this way, it is possible to form a marker capable of supporting high-precision positioning of the optical component mounting marker and the semiconductor laser device mounting marker formed on different substrates, so that an optical device mounting substrate having a laminated structure can be easily formed. Lasers and optical components can be incorporated with high accuracy.

  The through hole is preferably formed using anisotropic etching in order to form an accurate end surface of the first substrate.

  In addition, the method includes a step of forming a conductive film on the semiconductor laser element mounting portion of the first substrate.

In (1), the first substrate and the second substrate are silicon substrates, and the first substrate and the second substrate are laminated via a glass film.
(2) joining the first substrate and the second substrate on which the optical component mounting marker formed corresponding to the position where the reference marker and the optical component are mounted;
Based on the reference marker, forming a through hole in a region of the first substrate corresponding to a region where the optical component mounting marker of the second substrate is formed;
Forming a semiconductor laser element mounting marker corresponding to a position where the semiconductor laser element is mounted on the first substrate based on the reference marker;
And a step of dicing the first substrate and the second substrate to separate the optical device mounting substrate .

  It is preferable from the viewpoint of stability between the substrates that the groove penetrating the optical element mounting substrate is formed along the bonding surface between the first substrate and the second substrate.

  With these forms, the optical component to be mounted can be matched with the optical axis of the optical component and the semiconductor laser element by passive alignment mounting without being affected by surface roughness, warpage, and waviness of the mounting surface. Passive alignment can also reduce the mounting cost of optical components.

  In addition, cost can be reduced by wafer level bonding.

  The present invention can provide an optical element mounting substrate manufacturing method and an optical element mounting substrate that can contribute to solving at least one of the above problems.

  A stable and reliable form can be easily manufactured even during operation of an optical element device such as a laser beam emitting device.

  FIG. 1 is a perspective view of an optical element mounting substrate 1 according to a first embodiment of the present invention.

  The optical element mounting substrate 1 of the first embodiment is composed of a silicon substrate 2 having a plane orientation {100} and a glass substrate 3.

  An optical element mounting substrate for mounting a mounting portion of a semiconductor laser element and an optical component that transmits or reflects laser light emitted from the semiconductor laser element.

  A thin film electrode 8 and a thin film solder 10 electrically connected to the semiconductor laser through an oxide film are provided on the first surface. Further, a reference marker 9 for mounting a semiconductor laser is formed. A reference marker 7 for mounting the optical component is formed on the first surface of the glass substrate 3 as the second substrate. The second surface of the first substrate and the first surface of the second substrate are joined to each other, and the second substrate has a larger area as viewed in the stacking direction than the first substrate.

  A through-etching hole 11 is formed in the silicon substrate 2. In this case, anisotropic etching of silicon is applied. In addition, when forming methods other than anisotropic etching, for example, dry etching, are used for forming the through-etching holes 11, the same effect can be achieved regardless of the orientation of the surface of the silicon substrate 2. Further, the through-etching hole 11 may be formed by etching from one side or by etching from both sides.

  For example, the glass substrate 3 has a thermal expansion coefficient of approximately 33 × 10 −7 / ° C. and is close to the thermal expansion coefficient (23.3 × 10 −7 / ° C.) of the silicon substrate 2, and contains about 4% Na 2 O inside. It is a glass that can be anodically bonded to the silicon substrate 2 by using glass (for example, borosilicate glass). Further, the glass substrate 3 has a groove 5 formed by dicing on the surface thereof, that is, the first surface. The silicon substrate 2 provided with the through-etching holes 11 and the glass substrate 3 provided with the grooves 5 are bonded together by, for example, anodic bonding to form an integral laminated structure. As a result, an optical component mounting surface on which an optical component capable of surface mounting, such as a square aspherical lens and a prism, which is a part of the first surface of the glass substrate 3 can be mounted through the through-etching hole 11 of the silicon substrate 2. 4 is exposed. Since this optical component mounting surface 4 is the first surface 3 of the glass substrate, it is mirror-polished and has a very high flatness compared to the surface formed by etching.

  For example, in the case of an etching groove by anisotropic etching of silicon, surface roughness or undulation may occur on the bottom surface of the groove. Since the size of the square (rectangular) aspherical lens is about 1 mm even if it is small, the etching groove is required even if the depth is 500 μm. When such a deep etching groove and a large-area etching groove are formed, etching unevenness occurs on the bottom surface of the etching groove, which may not be a flat surface.

  For example, FIG. 12 shows the result of measuring the bottom surface of an etching groove formed by anisotropic etching of silicon and having a width of 7.0 mm, a length of 7.0 mm, and a depth of 0.75 mm. From this result, the bottom of the etching groove was not flat, and in this case, there was a depth variation of about 0.03 mm. Thus, there is a risk of flatness and surface roughness of the etching groove bottom. Even if the etching is performed by dry etching, it is not easy to suppress the roughness of the bottom surface of the etching groove and ensure flatness.

  Therefore, when optical components that can be surface-mounted, such as rectangular aspherical lenses and prisms, are mounted on the bottom surface of the etching groove, they are mounted inclined. As a result, in order to achieve optical coupling between the semiconductor laser element and the optical component, it must be fixed so as to correct the tilt of the component due to the waviness of the etching bottom surface. Mounting is not easy and may reduce productivity.

  In addition, since the optical component is positioned and mounted on the bottom surface of the etching groove, it is difficult to form a marker that is positioned with high accuracy and high accuracy by exposure or the like. This is because the bottom surface of the etching groove is dented from the substrate surface, so that the focus of the exposure light is shifted and the resolution of the resist is lowered and the pattern transfer accuracy is lowered. Furthermore, since the resist film thickness applied to the bottom surface of the etching groove changes depending on the position of the groove, the optimum exposure light quantity with respect to the resist film thickness changes. As a result, the pattern transfer accuracy is lowered and the shape of the positioning marker is destroyed. . It is not easy to form a pattern having a marker function on the bottom surface of the etching groove.

  For this reason, in order to make the optical axes of the optical component and the semiconductor laser element coincide with each other, active alignment, that is, a method in which the semiconductor laser element is actually emitted and optically coupled with the optical component is adopted. Cost is high and productivity is difficult to improve sufficiently.

  By forming as in this embodiment, surface mountable optical components such as a square aspherical lens and prism can be surface mounted on the bottom surface of the groove with the tilt, rotation and undulation of the components suppressed, and in advance Optical components are mounted by passive alignment (a mounting technique that allows optical coupling by simply placing components without emitting a semiconductor laser element) based on a high-precision marker that is positioned and formed on the bottom of the groove. it can.

  On the other hand, on the first surface, which is the surface of the silicon substrate 2, there is an installation portion for mounting the semiconductor laser element, and the thin film electrode 8 and the thin film solder 10 electrically connected to the semiconductor laser element form the oxide film 6. Is formed through. In addition, a marker 9 is formed on a part of the thin film electrode 8 in the installation portion where the semiconductor laser element is mounted in order to mount the semiconductor laser element with high accuracy. A semiconductor laser element is mounted on the basis of the marker 9. Thereby, high-precision positioning of the semiconductor laser element and high-precision positioning with the through-etching hole 11 are performed. In this way, a highly accurate positioning marker can be easily formed even between regions whose heights are large. Furthermore, an optical component mounting marker 7 representing the mounting position of the optical component is formed on the optical component mounting surface 4. A surface mounting type optical component is mounted on the basis of the optical component mounting marker 7. As will be described in detail in the contents of the manufacturing method, since the wafers are aligned and bonded with reference to the alignment marker formed on the outer periphery of the silicon wafer constituting the silicon substrate 2 and the glass wafer constituting the glass substrate 3, The relative positional relationship between the marker 9 formed on the basis of each alignment marker and the optical component mounting marker 7 can be defined with high accuracy. If these markers are formed in advance at a position where the semiconductor laser and the optical component can be optically coupled, the optical coupling between the semiconductor laser and the optical component can be easily achieved by passive alignment. According to the present embodiment, it is possible to easily achieve high accuracy of the relative positional relationship between the semiconductor laser mounting position and the optical component mounting position, that is, relative positioning between the mounted semiconductor laser and the optical component. This is because the manufacturing method of the optical element mounting substrate 1 is manufactured at the wafer level as described later. As a result, highly accurate positioning can be defined.

  Next, in order to easily achieve anodic bonding between the silicon substrate 2 and the glass substrate 3, the oxide film 6 is not formed on the second surface which is the back surface of the silicon substrate 2. An oxide film 6 is formed on the other surface, that is, the first surface and the side surface (slope) of the through-etching hole 11. Alternatively, when a silicon oxide film is formed on the first surface and a silicon oxide film is formed on the second surface for some reason, the thickness of the second surface oxide film is greater than that of the first surface oxide film. It is getting thinner.

In this case, the oxide film 6 is formed on the side surface, but there is no problem because the effect of the present embodiment can be obtained in the same manner even without the oxide film 6.
Although the silicon substrate 2 is drawn thicker than the glass substrate 3 in FIG. 1, the silicon substrate 2 and the glass substrate 3 may be approximately the same thickness, or the glass substrate 3 may be thicker.
Next, the shape of the groove 5 will be described with reference to FIG. FIG. 2 is a perspective view in which the silicon substrate 1 and the glass substrate 3 are separated. As shown in this figure, a groove 5 is formed in the glass substrate 3. The groove 5 is formed by dicing, that is, machining. The cross-sectional shape of the groove 5 is rectangular, but other cross-sectional shapes are not a problem. The groove 5 is an air vent groove provided to easily perform anodic bonding between the silicon substrate 2 and the glass substrate 3 in the atmosphere, and does not necessarily have to be on the first surface of the glass substrate 3. 2 may be on the second side. Furthermore, the groove 5 is not necessarily required if air can be degassed during anodic bonding. In other words, if the anodic bonding is performed in a vacuum, the problem of air defoaming is solved and is not necessary.

FIG. 3 is a perspective view showing a laser beam emitting device when the semiconductor laser element 13 and the square aspherical lens 12 are mounted on the optical element mounting substrate 1 shown in FIGS. 1 and 2.
The semiconductor laser element 13 is installed on the optical element semiconductor substrate using solder, and then an optical component such as a angulated spherical lens is installed using a resin adhesive. Thereby, the square aspherical lens 12 can be easily fixed with a resin adhesive or the like.
A semiconductor laser element 13 is mounted on the optical element mounting substrate 1 with reference to the marker 9 shown in FIG. The semiconductor laser element 13 is electrically connected to the thin film electrode 8 via the wire bonding 14 and the thin film solder 10. With this configuration, the semiconductor laser element 13 emits light and a laser beam is emitted by an electrical signal applied from the outside of the optical element mounting substrate 1.
The semiconductor laser element 13 has a ridge line portion between the side surface of the through-etching hole 11 and the first surface of the silicon substrate 2 so that the emitted laser beam does not interfere with or reflect on the first surface of the silicon substrate 2. In addition, it is preferable that the mounting is performed so that the end face provided with the laser emission port is located. FIG. 4 shows the aa ′ cross-section of FIG. 3 so that this state can be understood. The semiconductor laser element 13 is mounted on the first surface of the silicon substrate 2 so that the end face of the semiconductor laser element 13 having the laser emission port 15 is positioned in the vicinity of the through-etching hole 11. A square aspheric lens 12 is mounted on the optical component mounting surface 4 which is the first surface of the glass substrate 3. As shown in FIG. 4, the rectangular aspherical lens 12 is not in contact with any part other than the optical component mounting surface 4 which is a polished surface of the glass substrate 3, and is in contact with the bottom surface of the rectangular aspherical lens 12, and an adhesive is used. It is fixed by bonding. It is arranged at an interval from the end of the silicon substrate 2 which is a substrate on which the laser element is mounted.

  Naturally, the rectangular aspherical lens 12 is mounted on the basis of the optical component mounting marker 7 formed on the optical component mounting surface 4 with high accuracy. As a result, since the lens 12 is disposed at a distance from the submount end, the tilt of the rectangular aspherical lens 12 around the X axis and the Y axis in FIG. 3 does not occur. Regarding the optical axis misalignment around the Z axis, since the positions of the marker 9 and the optical component mounting marker 7 are defined with high accuracy, the semiconductor laser element 13 and the square aspherical lens 12 are used as a reference. The optical axis coincidence can be achieved simply by mounting in the case, so that the occurrence of optical axis deviation can be suppressed. Passive alignment mounting can contribute to coincidence of the optical axes of the semiconductor laser element 13 and the square aspherical lens 12. A marker manufacturing method for achieving the positioning of each marker with high accuracy will be described in detail in the manufacturing method described later. Briefly, bonding and all pattern formation are performed based on a pre-made reference marker in a photomask. In the case of the present embodiment, since the through-etching hole 11 is formed from the first surface by anisotropic etching of silicon, the angle formed between the side surface and the first surface of the glass substrate 3 is constant. The angle is 54.7 °.

Next, the manufacturing method of a 1st Example is demonstrated using FIG. In this manufacturing method, through holes are first formed by anisotropic etching of silicon, and then the silicon substrate and the glass substrate are positioned with reference to the silicon wafer and the fiducial markers formed on the glass wafer. A two-layer substrate structure is manufactured by bonding.
Specifically, for example, the reference marker 23 for wafer alignment and the through-etching hole 11 are formed on the silicon substrate 2 as the first substrate by etching. Then, an oxide film 6 is formed on the first substrate in which the through-etching holes 11 are formed. Next, the oxide film on the second surface located on the opposite side of the surface on which the marker of the first substrate is formed is removed. Then, the reference marker 22 for wafer alignment is formed on the first surface of the second glass substrate to be bonded to the first substrate, and the reference marker 22 for mounting the optical component is formed. Then, the second surface of the first substrate and the first surface of the second substrate are adjusted and overlaid on the basis of the reference markers for wafer alignment, and are stacked and fixed. A thin film electrode 8, a thin film solder 10, and a reference marker 9 for mounting a semiconductor laser element are formed on the first substrate. A reference marker for wafer alignment is formed on the first surface of the first substrate via an oxide film. . Then, individual optical element mounting groups are cut out from the multilayer structure substrate. The first substrate and the second substrate of the cut out optical element mounting substrate have a common cut surface.

Here, FIG. 8 is a cross-sectional view for easy understanding of a method of manufacturing an optical element mounting substrate having a characteristic structure. Therefore, it does not coincide with the cross section of the optical element mounting substrate shown in FIG. The manufacturing method will be described in accordance with steps a) to g) in FIG.
a) First, Si3N4 / SiO2 thin films 19 are formed on both sides of a silicon substrate 2 having a thickness of 750 μm and a plane orientation (100). The SiO2 film (for example, film thickness 120 nm) is a thermal oxide film formed by thermal oxidation, and the Si3N4 film (for example, film thickness 160 nm) is a film formed by a low pressure CVD (Chemical Vapor Deposition) method. Next, a through etching opening pattern 20 for forming a through etching hole 11 is provided in the Si3N4 / SiO2 thin film 19 formed on the first surface of the silicon substrate 2. At the same time, a mask pattern for forming a silicon reference marker 23 used to perform wafer bonding with high accuracy is formed on the Si3N4 / SiO2 thin film 19 on the outer periphery of the silicon wafer constituting the silicon substrate 2. The mask pattern in this case is formed on the first surface side of the silicon substrate 2. In this method, photolithography (resist coating, exposure, development, resist pattern formation and transfer of the pattern to the Si3N4 / SiO2 thin film 19 using the resist as a mask material) used in conventional semiconductor technology is applied, and Si3N4 / SiO2 is applied. RIE (Reactive Ion Etching) is applied to the etching of the thin film 19.
b) Next, using the Si3N4 / SiO2 thin film 19 as a mask material, anisotropic etching of silicon is performed with a 40 wt% potassium hydroxide aqueous solution (KOH) (temperature 70 ° C.). At this time, etching is performed until the silicon substrate 2 penetrates, that is, until the through-etching hole 11 is formed. At the same time, a silicon reference marker 23 is formed on the first surface side of the silicon substrate 2 at the outer peripheral portion of the silicon wafer. Note that the side surface 21 formed by through etching is composed of a {111} plane of silicon. In addition, tetramethylammonium water (TMAH) or ethylenediamine pyrocatechol water can also be used as the etching solution.

  c) Next, the Si3N4 / SiO2 thin film 19 is sequentially peeled off using hot phosphoric acid and BHF (HF + NH4F mixed aqueous solution). Thereafter, a silicon oxide film 6 having a thickness of about 1 μm is formed on the surface of the silicon substrate 2 by thermal oxidation.

  d) Further, the second surface of the silicon substrate 2 is mechanically polished to remove the silicon oxide film 6.

  e) A Cr thin film is formed on the first surface of the glass substrate 3 having a thickness of 300 μm by sputtering, patterning is performed, and the optical component mounting marker 7 is formed. At the same time, the glass reference marker 22 is formed on the outer periphery of the glass wafer constituting the glass substrate 3. In this case, it is preferable to form the glass by etching. Similarly to the first surface, a Cr thin film may be formed, and the pattern of the glass reference marker 22 may be formed by etching. These marker patterns must be arranged on the photomask so that the positions (pattern centers) of the silicon reference marker 23 and the glass reference marker 22 previously formed coincide with each other. For etching the Cr thin film, wet etching or dry etching may be applied. In addition, you may use a vacuum evaporation method for the film-forming of Cr thin film. Next, a groove 5 having a depth of 100 μm is formed on the first surface of the glass substrate 3 by dicing. At this time, the adhesive material escape groove 18 described in the third embodiment, for example, a groove having a depth of 50 μm, can be formed on the optical component mounting surface 4. In the first embodiment shown in FIG. 1, the adhesive escape groove 18 is not described, but is described in FIG. The Cr thin film here may be a film having another composition as long as the pattern shape to be formed is visible. Next, the glass substrate 3 and the silicon substrate 2 are anodic bonded in the atmosphere. For example, bonding can be performed at a substrate heating temperature of 400 ° C. and an applied voltage of 300V. Since the air vent groove 5 is formed in the glass substrate 3, it is possible to join the air without accumulating on the joint surface. Here, the joining method will be additionally described with reference to FIG. The silicon substrate 2 is made of a silicon wafer 25, and the glass substrate 3 is made of a glass substrate 26. As described above, the silicon reference marker 23 is formed on the outer peripheral portion of the silicon wafer 25, and the glass reference marker 22 is formed on the outer peripheral portion of the glass wafer 26.

  Since these markers are formed in advance on the photomask together with the transfer pattern, their placement locations are defined with high accuracy, for example, with a positional accuracy of ± 0.5 μm. In this case, the glass reference marker 22 is formed on the second surface of the glass substrate 3 (glass wafer 26). These markers are observed with a microscope, and the silicon reference marker 23 is moved and overlapped so that the position of the silicon reference marker 23 coincides with that of the glass reference marker 22 (the center of the marker matches). After that, voltage is applied according to the bonding conditions shown above, and anodic bonding is performed. In this way, high-accuracy positioning anodic bonding at the wafer level is achieved. Each marker preferably has a point-symmetric shape in order to facilitate superposition.

  f) A thin film electrode 8 with a marker 9 for applying a current voltage to the semiconductor laser element and a thin film solder 10 for fixing the semiconductor laser element to the silicon substrate 2 are formed on the silicon substrate 2. At this time, the thin film electrode 8 and the thin film solder 10 are formed by using the glass reference marker 22 or the silicon reference marker 23 as a reference. As a result, the positional relationship between the optical component mounting marker 7 and the marker 9 is defined with high accuracy. The composition of the thin film electrode is desirably an Au (for example, a film thickness of 500 nm) / Pt (for example, a film thickness of 300 nm) / Ti (for example, a film thickness of 100 nm) thin film. Either the sputtering method or the vacuum evaporation method is applied as the film forming method. In this case, any metal film may be used as long as it is a metal film. In addition, an Au / Ti thin film, an Al thin film, an Au / Cr thin film, and an Au / Ni / Cr thin film can be considered. As a thin film patterning method, it is preferable to use photolithography to form a resist pattern and use the ion milling method as a mask. It is also possible to perform patterning using a lift-off method. In particular, when the thin film solder 12 is formed, it can be said that it is appropriate to use the lift-off method. Here, as a resist coating method, a spin coating method or a spray coating method can be used.

g) Finally, the silicon substrate 2 and the glass substrate 3 are cut into desired shapes (for example, a width of 3 mm, a length of 4 mm, and a thickness of about 1 mm) by dicing.
Note that the through etching in step b) may be performed from both sides instead of from one side. Further, in the present manufacturing method, the example in which the marker 9 for mounting the semiconductor laser element is manufactured simultaneously with the formation of the thin film electrode 8 has been described. An inverted pyramid-shaped groove formed by isotropic etching may be formed and used as the marker 9.

  The optical element mounting substrate 1 according to the first embodiment of the present invention can be obtained by sequentially performing the steps as described above.

  Next, the second manufacturing method of the first embodiment will be described with reference to FIG. In this manufacturing method, first, a silicon substrate and a glass substrate are anodically bonded to produce a two-layered substrate, and then through holes are formed by anisotropic etching of silicon. For example, an etching mask thin film is formed on the first surface of a first silicon substrate. Then, a reference marker for wafer alignment is formed on the second surface of the second substrate made of glass, and a reference marker for mounting optical components is formed on the first surface. The second surface of the first substrate and the first surface of the second substrate are joined to form a multilayer structure substrate. Next, a through hole is formed by etching with reference to a reference marker for wafer alignment of the second substrate. Then, a thin film electrode, a thin film solder, and a reference marker for mounting an optical component are formed on the first surface of the first substrate with reference to the reference marker for wafer alignment. Then, the multilayer structure substrate is cut to cut out individual optical element mounting substrates.

Here, FIG. 10 is a cross-sectional view for easy understanding of a method of manufacturing an optical element mounting substrate having a characteristic structure. The manufacturing method will be described in accordance with steps a) to e) in FIG.
a) First, Si3N4 / SiO2 thin films 19 are formed on both sides of a silicon substrate 2 having a thickness of 750 μm and a plane orientation (100). The SiO2 film (for example, a film thickness of 1 μm) is a thermal oxide film formed by thermal oxidation, and the Si3N4 film (for example, film thickness of 160 nm) is a film formed by a low pressure CVD (Chemical Vapor Deposition) method. Next, the second surface which is the back surface of the silicon substrate 2 is polished, and the Si3N4 / SiO2 thin film 19 is removed. Next, the glass reference marker 22 is formed on the second surface of the outer peripheral portion of the glass wafer 26 constituting the glass substrate 3. Using this reference marker 22 as a reference, the optical substrate mounting marker 7 is formed by etching the glass substrate on the first surface of the glass substrate 3 (glass wafer 26) by RIE or wet etching using a double-side exposure apparatus. Note that photolithography used in conventional semiconductor technology is applied to these forming methods. Further, a groove 5 having a depth of 100 μm is formed on the first surface by dicing. Next, the silicon substrate 2 and the glass substrate 3 are fixed by anodic bonding in the atmosphere. The groove 5 serves as a groove for venting air and suppresses air from staying on the joint surface. The thickness of the glass substrate 3 at this time is 300 μm. Examples of bonding conditions include a substrate heating temperature of 400 ° C. and an applied voltage of 300V.

b) Next, a through etching opening pattern 20 for forming the through etching hole 11 in the Si3N4 / SiO2 thin film 19 is provided on the first surface of the silicon substrate 2. The through-etching opening pattern 20 is formed using a double-sided exposure apparatus with reference to the glass reference marker 22 already formed on the second surface of the glass substrate 3. At the same time, a silicon reference marker 23 is formed on the first surface on the outer periphery of the silicon wafer 25 constituting the silicon substrate 2. In these methods, photolithography used in the conventional semiconductor technology is applied, and RIE (Reactive Ion Etching) is applied to the etching of the Si3N4 / SiO2 thin film 19.
c) Next, using the Si3N4 / SiO2 thin film 19 as a mask material, anisotropic etching of silicon is performed with a 40 wt% potassium hydroxide aqueous solution (temperature 70 ° C.). At this time, etching is performed until the silicon substrate 2 penetrates and the optical component mounting surface 4 is exposed, that is, until the through-etching hole 11 is formed. The side surface 21 formed by through etching is composed of a {111} plane of silicon. Other etching solutions include tetramethylammonium water (TMAH) and ethylenediamine pyrocatechol water. Next, the Si3N4 thin film of the Si3N4 / SiO2 thin film 19 is peeled off using hot phosphoric acid. As a result, the oxide film 6 is formed on the first surface of the silicon substrate 2.

  d) A thin film electrode 8 with a marker 9 for applying a current voltage to the semiconductor laser element and a thin film solder 11 for fixing the semiconductor laser element to the silicon substrate 2 are formed on the silicon substrate 2. These are formed based on the silicon reference marker 23 formed on the first surface on the outer periphery of the silicon wafer 25. As a result, the positional relationship between the marker 9 and the optical component mounting marker 7 is defined with high accuracy. Here, the composition of the thin film electrode 8 is desirably an Au (for example, a film thickness of 500 nm) / Pt (for example, a film thickness of 300 nm) / Ti (for example, a film thickness of 100 nm) thin film. Either the sputtering method or the vacuum evaporation method is applied as the film forming method. In this case, any metal film may be used as long as it is a metal film. In addition, an Au / Ti thin film, an Al thin film, an Au / Cr thin film, and an Au / Ni / Cr thin film can be considered. As a thin film patterning method, it is preferable to use photolithography to form a resist pattern and use the ion milling method as a mask. It is also possible to perform patterning using a lift-off method. In particular, when forming the thin film solder 10, it can be said that it is appropriate to use the lift-off method. Here, as a resist coating method, a spin coating method or a spray coating method can be used.

e) Finally, the silicon substrate 2 and the glass substrate 3 are cut into desired shapes (for example, a width of 3 mm, a length of 4 mm, and a thickness of about 1 mm) by dicing.
In steps a) and b), the through etching opening pattern 20 may be formed first, and then anodic bonding between the silicon substrate 2 and the glass substrate 3 may be performed. At that time, the silicon reference marker 23 formed on the first surface of the silicon wafer 25 constituting the silicon substrate 2 and the glass reference marker 22 formed on the second surface of the glass wafer 26 constituting the glass substrate 3. With reference to each of the markers, the two wafers are positioned and overlapped and anodic bonded. Further, in this manufacturing method, the example in which the marker 9 for mounting the semiconductor laser element is manufactured simultaneously with the formation of the thin film electrode 8 has been described. An inverted pyramid-shaped groove formed by isotropic etching may be formed and used as the marker 9.

  The optical element mounting substrate 1 according to the first embodiment of the present invention can also be obtained by sequentially performing the steps as described above. In this manufacturing method, unlike the first embodiment shown in FIG. 1, the oxide film 6 is not formed on the side surface 21, but there is no problem in achieving the intended effect.

The optical element mounting substrate according to the embodiment of the present invention has a two-layer structure, and a groove is formed by performing through etching on the upper substrate, and the polished surface of the lower substrate is used as the bottom of the groove. The bottom surface of the groove can be made flat without being affected by roughening, warping or undulation. That is, a flat surface can be secured without being affected by the processing accuracy.
Since this bottom surface is a mounting surface for optical components that can be surface-mounted, such as rectangular aspherical lenses and prisms, it is possible to eliminate the mounting tilt of optical components and to correct the tilt of optical components. Absent.
The optical element mounting substrate manufacturing method of the present invention employs a method of forming a marker at the wafer level, positioning and bonding based on the marker, and mounting the optical component on the bottom surface of the groove where the optical component is placed. Can be formed with high accuracy and in a state of being positioned with high accuracy.
Furthermore, the optical element mounting substrate of the present invention can define the positional relationship between the marker indicating the optical component mounting position and the marker indicating the semiconductor laser element mounting position formed on the first surface of the upper substrate with high accuracy. Therefore, the optical axes of the optical component and the semiconductor laser element can be matched by passive alignment mounting, which can contribute to a reduction in mounting cost.
Finally, since the optical element mounting substrate of the present invention can be manufactured at the wafer level in a large number of optical element mounting substrates, the manufacturing cost can be reduced.

  FIG. 5 is a perspective view of the optical element mounting substrate 1 according to the second embodiment of the present invention. The configuration is basically the same as that shown in the first embodiment, but has the following features.

The optical element mounting substrate 1 of the second embodiment is composed of a silicon substrate 2 having a plane orientation {100} and a second silicon substrate 24. The plane orientation of the second silicon substrate 24 may be any. A through-etching hole 11 is formed in the silicon substrate 2. In this case, anisotropic etching of silicon is applied. Further, an air vent groove 16 formed by dicing is formed on the back surface of the silicon substrate 2, that is, the second surface. In addition, although anisotropic etching is effective for formation of the through-etching hole 11, in other cases, for example, when dry etching is used, any orientation may be used as the surface orientation of the silicon substrate 2.
A glass thin film 17 is formed on the surface of the second silicon substrate 24, that is, the first surface. For example, this glass thin film 17 has a thermal expansion coefficient of approximately 33 × 10 −7 / ° C., which is close to the thermal expansion coefficient (23.3 × 10 −7 / ° C.) of the silicon substrate 2, and contains about 4% Na 2 O inside. It is a glass containing a large amount (for example, borosilicate glass). Using this glass thin film 17, the silicon substrate 2 provided with the through-etching hole 11 and the second silicon substrate 24 are joined by anodic bonding and integrated. As a result, the glass thin film 17 covering the optical component mounting surface 4 which is a part of the first surface of the second silicon substrate 24 is exposed through the through-etching hole 11 of the silicon substrate 2. Since the optical component mounting surface 4 is the first surface of the second silicon substrate 24 that has been subjected to mirror polishing, although the glass thin film 17 is formed, the optical component mounting surface 4 is flatter than the surface formed by etching. Is very expensive.

  On the other hand, on the first surface, which is the surface of the silicon substrate 2, there is an installation portion for mounting the semiconductor laser element, and the thin film electrode 8 and the thin film solder 10 electrically connected to the semiconductor laser element form the oxide film 6. Is formed through. In addition, a marker 9 is formed on a part of the thin film electrode 8 in the installation portion where the semiconductor laser element is mounted in order to mount the semiconductor laser element with high accuracy. A semiconductor laser element is mounted on the basis of the marker 9. Thereby, high-precision positioning of the semiconductor laser element is performed. Furthermore, an optical component mounting marker 7 representing the mounting position of the optical component is formed on the optical component mounting surface 4. Surface mount type optical components are mounted on the basis of the marker 7. Similarly to the first embodiment, each wafer is applied with reference to alignment markers formed on the outer periphery of the silicon wafer constituting the silicon substrate 2 and the glass wafer constituting the glass substrate 3 by applying a semiconductor transfer technique. Since they are joined, the relative positional relationship between the marker 9 formed on the basis of each alignment marker and the optical component mounting marker 7 can be defined with high accuracy. In order to achieve passive alignment in the second embodiment, it is necessary to previously form these markers at positions where optical coupling can be achieved. Note that an oxide film 6 is required on the first surface of the silicon substrate 2 in order to ensure electrical insulation.

Although the silicon substrate 2 is drawn thicker than the second silicon substrate 24 in FIG. 5, the thicknesses of the silicon substrate 2 and the second silicon substrate 24 may be approximately the same, or the second silicon substrate 24 may be thicker. .
FIG. 6 is a perspective view showing a laser beam emitting apparatus when the semiconductor laser element 13 and the square aspherical lens 12 are mounted on the optical element mounting substrate 1 shown in FIG. The semiconductor laser element 13 is mounted on the optical element mounting substrate 1 with reference to the marker 9 shown in FIG. The semiconductor laser element 13 is electrically connected to the thin film electrode 8 via the wire bonding 14 and the thin film solder 10. As a result, the semiconductor laser element 13 oscillates and emits a laser beam by an electrical signal given from the outside of the optical element mounting substrate 1. As in the mounting example of the first embodiment, the semiconductor laser element 13 is mounted so that the emitted laser beam does not reflect or interfere with the first surface of the silicon substrate 2.

  A rectangular aspheric lens 12 is mounted on the optical component mounting surface 4 of the glass thin film 17 that covers the first surface of the second silicon substrate 24. At this time, the rectangular aspherical lens 12 is in contact with the optical component mounting surface 4 which is the polishing surface of the second silicon substrate 24. And it arrange | positions via the space | interval from the end surface of the silicon substrate 2. Or it contacts only with the bottom face of the square aspherical lens 12, and is fixed by adhesion using an adhesive. As a result, the rectangular aspherical lens 12 around the X axis and the Y axis in FIG. 6 is mounted without falling. Further, the rectangular aspherical lens 12 is mounted using an adhesive on the basis of the optical component mounting marker 7 that preliminarily defines the position where the optical coupling between the rectangular aspherical lens 12 and the semiconductor laser element 13 can be taken. There is no misalignment of the surroundings. In the case of the second embodiment, since the through-etching hole 11 is formed by anisotropic etching of silicon, the angle formed between the side surface and the first surface of the second silicon substrate 24 is constant. The angle is 54.7 °.

  Next, the manufacturing method of the second embodiment will be described with reference to FIG. In this manufacturing method, first, a through hole is formed by anisotropic etching of silicon, and then a reference marker used for bonding described in the previous embodiment is formed. The silicon substrate and the silicon substrate on which the glass thin film is formed on the first surface are positioned on the basis of the reference marker formed on the silicon wafer and the second silicon wafer on which the silicon substrate is formed, and bonded by anodic bonding to form a two-layer substrate structure Is produced.

  For example, a reference marker for wafer alignment and a through hole are formed on a first surface of a first substrate made of silicon by etching, and an oxide film is formed on the first substrate in which the through hole is formed. And the oxide film of the 2nd surface on the opposite side to the surface which described the said marker of a 1st board | substrate is removed. Next, a reference marker for wafer alignment is formed on the second surface of the second substrate made of silicon, and a reference marker for mounting optical components is formed on the first surface which is the opposite surface. A glass thin film is formed on the first surface of the second substrate. Next, the second surface of the first substrate and the first surface of the second substrate are adjusted and overlapped with reference to each wafer alignment reference marker to form a multilayer structure substrate. Then, the thin film electrode, the thin film solder, and the reference marker for mounting the semiconductor laser element are formed on the first substrate, and the first surface of the first substrate is formed through the oxide film with reference to the reference marker for wafer alignment. . Then, individual optical element mounting substrates are cut out from the multilayer structure substrate.

Here, FIG. 11 is a cross-sectional view shown for easy understanding of the manufacturing method of the optical element mounting substrate 1 having a characteristic structure. Therefore, it does not coincide with the cross section of the optical element mounting substrate 1 shown in FIG. The manufacturing method will be described in accordance with steps a) to g) in FIG.
a) First, Si3N4 / SiO2 thin films 19 are formed on both sides of a silicon substrate 2 having a thickness of 750 μm and a plane orientation (100). The SiO2 film (for example, film thickness 120 nm) is a thermal oxide film formed by thermal oxidation, and the Si3N4 film (for example, film thickness 160 nm) is a film formed by a low pressure CVD (Chemical Vapor Deposition) method. Next, a through etching opening pattern 20 for forming a through etching hole 11 is provided in the Si3N4 / SiO2 thin film 19 formed on the first surface of the silicon substrate 2. At the same time, a mask pattern for forming a silicon reference marker 23 used to perform wafer bonding with high accuracy is formed on the Si3N4 / SiO2 thin film 19 on the outer periphery of the silicon wafer constituting the silicon substrate 2. The mask pattern in this case is formed on the first surface side of the silicon substrate 2. In this method, photolithography used in the conventional semiconductor technology is applied, and RIE (Reactive Ion Etching) is applied to the etching of the Si3N4 / SiO2 thin film 19.
b) Next, using the Si3N4 / SiO2 thin film 19 as a mask material, anisotropic etching of silicon is performed with a 40 wt% potassium hydroxide aqueous solution (temperature 70 ° C.). At this time, etching is performed until the silicon substrate 2 penetrates, that is, until the through-etching hole 11 is formed. At the same time, a silicon reference marker 23 is formed on the outer surface of the silicon wafer on the first surface side of the silicon substrate 2. Note that the side surface 21 formed by through etching is composed of a {111} plane of silicon. In addition, examples of etchants that can perform anisotropic etching include tetramethylammonium water (TMAH) and ethylenediamine pyrocatechol water.

  c) Next, the Si3N4 / SiO2 thin film 19 is sequentially peeled off using hot phosphoric acid and BHF (HF + NH4F mixed aqueous solution). Thereafter, a silicon oxide film 6 having a thickness of about 1 μm is formed on the surface of the silicon substrate 2 by thermal oxidation.

  d) Further, the second surface of the silicon substrate 2 is mechanically polished to remove the silicon oxide film 6. Then, the air vent groove 16 is formed on the second surface of the silicon substrate 2 by dicing.

  e) For example, a second silicon substrate 24 having a surface orientation (100) of 300 μm thickness is prepared, and an etching groove having a depth of about 10 μm is formed on the first surface by the anisotropic etching of silicon described above. The optical component mounting marker 7 is formed. At this time, the second silicon reference marker is formed on the second surface of the outer peripheral portion of the second silicon wafer constituting the second silicon substrate 24 by etching. In this production, dry etching can be used in addition to applying the method shown in steps a) to b). At this time, the adhesive material escape groove 18 described in the third embodiment, for example, a groove having a depth of 50 μm, can be formed on the optical component mounting surface 4. In the second embodiment shown in FIG. 5, the adhesive escape groove 18 is not described, but is described in FIG. Thereafter, the second silicon substrate 24 is not formed on the surface except for a natural oxide film. A glass thin film 17 is formed on the first surface by sputtering. For example, the film thickness is 1 μm. The glass thin film 17 at this time is made of borosilicate glass that contains a large amount of Na2O of about 4% and has a linear expansion coefficient close to that of the silicon substrate 2 or the second silicon substrate 24. The silicon reference marker 23 and the second silicon reference marker 23 formed in advance are overlapped by alignment and fixed in position, and the silicon substrate 2 and the second silicon substrate 24 are bonded by anodic bonding using the glass thin film 17 as an insert material. And are joined in the atmosphere. For example, bonding can be performed at a substrate heating temperature of 400 ° C. and an applied voltage of 50V. Since the air vent groove 16 is formed in the silicon substrate 2, it is possible to join the air without accumulating on the joint surface. The alignment at the time of joining can be performed by a method similar to the method shown in FIG. 9 described in the manufacturing method of the first embodiment.

  f) A thin film electrode 8 with a marker 9 for applying a current voltage to the semiconductor laser element and a thin film solder 10 for fixing the semiconductor laser element to the silicon substrate 2 are formed on the bonded silicon substrate 2. At this time, the thin film electrode 8 and the thin film solder 10 are formed by using the silicon reference marker 23 as a reference. As a result, the positional relationship between the optical component mounting marker 7 and the marker 9 is defined with high accuracy. The composition of the thin film electrode is desirably an Au (for example, a film thickness of 500 nm) / Pt (for example, a film thickness of 300 nm) / Ti (for example, a film thickness of 100 nm) thin film. Either the sputtering method or the vacuum evaporation method is applied as the film forming method. In this case, any metal film may be used as long as it is a metal film. In addition, an Au / Ti thin film, an Al thin film, an Au / Cr thin film, and an Au / Ni / Cr thin film can be considered. As a thin film patterning method, it is preferable to use photolithography to form a resist pattern and use the ion milling method as a mask. It is also possible to perform patterning using a lift-off method. In particular, when the thin film solder 12 is formed, it can be said that it is appropriate to use the lift-off method. Here, as a resist coating method, a spin coating method or a spray coating method can be used.

g) Finally, the silicon substrate 2 and the second silicon substrate 24 are cut into desired shapes (for example, a width of 3 mm, a length of 4 mm, and a thickness of about 1 mm) by dicing.
Note that the through etching in step b) may be performed from both sides instead of from one side. Further, in the present manufacturing method, the example in which the marker 9 for mounting the semiconductor laser element is manufactured simultaneously with the formation of the thin film electrode 8 has been described. An inverted pyramid-shaped groove formed by isotropic etching may be formed and used as the marker 9.
The optical element mounting substrate 1 according to the second embodiment of the present invention can be obtained by sequentially performing the steps as described above.

  FIG. 7 is a perspective view of an optical element mounting substrate 1 according to a third embodiment of the present invention. In this embodiment, a silicon substrate 2 and a glass substrate 3 are provided. The silicon substrate 2 has a through-etching hole 11 formed by silicon dry etching (DRIE), and further includes a glass substrate 3. Is provided with an adhesive relief groove 18 for releasing excess adhesive when the optical component is adhered. In this case, the adhesive clearance groove 18 is a groove formed by machining by dicing, is formed at a position that does not cross the optical component mounting marker 7, and is formed so as to cross the surface (area) on which the optical component is mounted. ing. By forming in this way, it is possible to efficiently release the adhesive material in addition to the mounting surface.

On the other hand, the oxide film 6 is not formed on the side surface of the through-etching hole 11 by dry etching, and the angle α formed between the side surface and the first surface of the glass substrate 3 is the same as in the first and second embodiments. It is not 54.7 °. In the case of the third embodiment, since the through-etching hole 11 is formed by silicon DRIE, the angle α formed between the side surface and the first surface of the glass substrate 3 is not constant and varies depending on the etching conditions. To do. Usually, α is said to be 90 °, but not limited thereto. For example, α that becomes a reverse tapered shape is larger than 90 °, or α that becomes a tapered shape is less than 90 °. In the third embodiment shown in FIG. 7, a reverse taper shape, that is, a case where α is larger than 90 ° is shown. Thus, even if the value of α changes, the third embodiment can sufficiently achieve the effect intended by the present invention.
In the third embodiment, the side surface shape of the through-etching hole 11 formed by DRIE and the adhesive material escape groove 18 on a part of the optical component mounting surface 4 of the glass substrate 3 for mounting a square aspherical lens or prism are mounted. This is different from the first embodiment in that and are formed. Except for these structures, the second embodiment is the same as the first embodiment. Conversely, as described above, the adhesive material escape groove 18 may be formed in the first embodiment or the second embodiment. Also in the third embodiment, since the marker 9 and the optical component mounting marker 7 are positioned with high precision, the light between the semiconductor laser element and the surface mounting type optical component such as a rectangular aspherical lens or prism can be used. The axes can be easily matched by passive alignment.

Next, a description will be given of the case where the semiconductor laser element 13 and the square aspherical lens 12 are mounted in the case where the third embodiment is used, but basically the same method as in the first and second embodiments. Implement with. That is, the semiconductor laser element 13 is mounted with reference to the marker 9. The rectangular aspherical lens 12 is brought into contact only with the optical component mounting surface, and is fixed using an adhesive on the basis of the optical component mounting marker 7. The optical axes of the semiconductor laser element 13 and the square aspherical lens 12 are achieved by passive alignment with each marker reference arrangement.
This optical mounting board can be applied as an optical bench for mounting surface-mounting type optical components such as a square aspheric lens in a laser diode module or a photodiode module for optical communication. Further, it can be used as an optical bench for mounting optical components such as a prism and a lens in a device that reads or writes an optical signal using a medium such as a DVD, CD-R, or CD-ROM.

It is a perspective view of the optical element mounting substrate which is the 1st Example of this invention. It is a disassembled perspective view of the optical element mounting substrate shown in FIG. FIG. 2 is a perspective view showing a laser beam emitting apparatus in which a semiconductor laser element and a square aspheric lens are mounted on the optical element mounting substrate shown in FIG. 1. It is sectional drawing which shows the aa 'cross section shown in FIG. It is a perspective view of the optical element mounting substrate which is the 2nd Example of this invention. FIG. 6 is a perspective view showing a laser beam emitting apparatus in which a semiconductor laser element and a square aspheric lens are mounted on the optical element mounting substrate shown in FIG. 5. It is a perspective view of the optical element mounting substrate which is the 3rd Example of this invention. It is a process flowchart which shows the manufacturing method of the 1st Example of this invention. It is a schematic diagram which shows the high precision positioning joining method of a wafer level. It is a process flow figure showing the 2nd manufacturing method of the 1st example of the present invention. It is a process flowchart which shows the manufacturing method of the 2nd Example of this invention. It is a shape evaluation result figure which measured the state of the etching bottom face when etching 0.75 mm by anisotropic etching of silicon.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical element mounting substrate, 2 ... Silicon substrate, 3 ... Glass substrate, 4 ... Optical component mounting surface, 5 ... Groove, 6 ... Oxide film, 7 ... Optical component mounting marker, 8 ... Thin film electrode, 9 ... Marker, DESCRIPTION OF SYMBOLS 10 ... Thin-film solder, 11 ... Through-etching hole, 12 ... Square aspherical lens, 13 ... Semiconductor laser element, 14 ... Wire bonding, 15 ... Laser emission port, 16 ... Air vent groove, 17 ... Glass thin film, 18 ... Adhesive Escape groove, 19 ... Si3N4 / SiO2 thin film, 20 ... opening pattern for through etching, 21 ... side surface, 22 ... glass reference marker, 23 ... silicon reference marker, 24 ... second silicon substrate, 25 ... silicon wafer, 26 ... glass wafer DESCRIPTION OF SYMBOLS 101 ... Silicon substrate 102 ... Etch groove bottom surface 103 ... Semiconductor laser element 104 ... Rectangular aspherical lens 105 ... Oxide film 106 ... First surface

Claims (7)

A method of manufacturing an optical element mounting substrate comprising: a semiconductor laser element mounting portion; and an optical component mounting portion that optically communicates with the semiconductor laser element and emits laser light to the outside.
Forming a first reference marker and a through hole in the first substrate;
Forming a second reference marker and an optical component mounting marker corresponding to the optical component mounting portion on a second substrate;
The optical component mounting marker is positioned in a region where the through hole is formed by associating the first substrate and the second substrate with the first reference marker and the second reference marker. A step of joining so as to
And a step of dicing the bonded substrates to separate the optical device mounting substrate. 2. The optical component mounting of the second substrate according to claim 1, after the first substrate and the second substrate are joined, on the first substrate, based on the first reference marker. A method of manufacturing an optical element mounting substrate, comprising the step of forming a semiconductor laser element mounting marker at a position corresponding to the mounting portion of the semiconductor laser element corresponding to the marker for use. 2. The semiconductor laser element mounting marker according to claim 1, wherein a first reference marker and a through hole are formed on the first substrate, and the semiconductor laser element mounting marker is located at a position corresponding to the mounting portion of the semiconductor laser element based on the first reference marker. The manufacturing method of the optical element mounting board | substrate characterized by including the process of forming.   2. The optical element mounting substrate according to claim 1, further comprising a step of forming an oxide film on the first substrate and removing the oxide film on the bonding surface before bonding to the second substrate. Production method.   2. The optical device mounting according to claim 1, further comprising a step of forming a conductive film on the semiconductor laser device mounting portion of the first substrate after the first substrate and the second substrate are bonded. A method for manufacturing a substrate. In a method of manufacturing an optical element mounting substrate, comprising: a semiconductor laser element mounting portion; and an optical component mounting portion that optically communicates with the semiconductor laser element and emits laser light to the outside.
Bonding the first substrate and the second substrate provided with the optical component mounting marker corresponding to the position where the reference marker and the optical component are mounted;
Based on the reference marker, forming a through hole in a region of the first substrate corresponding to a region where the optical component mounting marker of the second substrate is formed;
Forming a semiconductor laser element mounting marker corresponding to a position where the semiconductor laser element is mounted on the first substrate based on the reference marker;
And a step of dicing the first substrate and the second substrate to separate the optical device mounting substrate.   2. The optical element mounting according to claim 1, wherein the first substrate and the second substrate are silicon substrates, and the first substrate and the second substrate are laminated via a glass film. A method for manufacturing a substrate.

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