JP4471508B2 - Manufacturing method of optical component mounting substrate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, a fiber stub including an optical fiber, an optical waveguide such as an optical fiber and an optical waveguide, and an optical semiconductor element such as a light-emitting element and a light-receiving element are arranged on a substrate, and these optical components are optically and accurately arranged. The present invention relates to an optical component mounting substrate that can be combined, a manufacturing method thereof, and an optical module.
[0002]
[Prior art]
In recent years, there has been a demand for large capacity and multi-functionality of optical communication systems, and accordingly, miniaturization, high integration, and low cost of optical communication modules such as optical transmitters and optical receivers have been demanded. ing.
[0003]
In particular, for the purpose of reducing the assembly cost of an optical communication module, a technology for mounting optical components such as optical fibers and semiconductor optical elements on a substrate for mounting optical components using a silicon substrate (also called a silicon platform), so-called Optical modules using optical hybrid mounting technology have been actively developed.
[0004]
According to the above technology, this optical component mounting substrate is formed with V-grooves for arranging optical fibers and solder bumps for arranging / fixing optical semiconductor elements. Loss when the optical axis of the optical semiconductor element and the optical axis of the optical fiber are not aligned in a straight line with an accuracy of ± 1.0 μm or less in the horizontal and vertical directions. Therefore, the relative position of the V groove and the solder bump needs to be highly accurate.
[0005]
Hereinafter, a conventional example of the optical component mounting board will be described.
First, as shown in FIG. 7A, a first insulating film 52 is formed on the surface of the silicon substrate 51, and then a conductor layer 53 having a predetermined shape is formed on the first insulating film 52. Next, as shown in FIG. 7B, the second insulating film 54 is formed on the first insulating film 52 and the conductor layer 53, and the periphery of the conductor layer 53 is not overlapped with a predetermined portion. The first opening 58 from which the insulating film 54 is removed to expose the conductor layer 53 is not overlapped with the first opening 58, and the first and second insulating films 52 and 54 are removed to expose the silicon substrate 51. The second opening 59 is formed. Next, as shown in FIG. 7C, a V-groove is formed in the second opening 59 where the silicon substrate 51 is exposed, using the first and second insulating films 52 and 54 as an etching mask. Finally, as shown in FIG. 7D, solder bumps 57 are formed on the first openings 58 where the conductor layers 53 are exposed.
[0006]
Here, the second opening 59 is formed by the second insulating film 54, and acts as a solder flow prevention function (hereinafter, solder dam) due to the difference in solder wettability between the conductor layer and the insulating film. Therefore, by simultaneously forming the first opening 58 for forming the V-groove and the second opening 59 for positioning the solder, the optical semiconductor element and the optical axis of the optical fiber can be aligned with high accuracy. (See JP-A-8-220385).
[0007]
[Problems to be solved by the invention]
However, the conventional manufacturing method requires a very complicated process of repeatedly performing the thin film formation process, the photolithography process, and the etching process as described above, and performs anisotropic etching after forming the conductor layer. The etchant enters the interface between the substrate surface and the conductor layer, the interface between the first insulating film and the second insulating film, or the interface between the second insulating film and the conductor layer when the V-groove is formed. There is a problem that the shape of the solder dam collapses due to the occurrence of etch pits in the lower part of the film. This also causes the solder to protrude outside the conductor layer, resulting in a short circuit due to contact with other parts, or the optical semiconductor element placement position being shifted, resulting in an optical coupling efficiency between the optical semiconductor element and the optical fiber. There was a problem that decreased. Further, after the V-groove formation, there is a problem that the etching-resistant film remaining as an eaves breaks in the course of the process and becomes dust and reattaches to the substrate surface.
[0008]
Positioning with solder bumps can be easily performed in the optical axis direction and in the lateral direction perpendicular thereto, but the height direction depends on the bump height, and the desired height can be increased by melting and pressing the solder bumps. There was a problem that the optical axis could not be reliably aligned.
[0009]
In addition to the above method, or when using an alignment marker or the like without positioning with solder bumps, it is not only necessary to produce the V groove and alignment marker with high positional accuracy, but also the marker and V groove. Position error, marker and V-groove fabrication error, marker recognition error, alignment error, etc., complicatedly entangled with each other, resulting in inadequate optical coupling or alignment when mounting an optical semiconductor element. There was a problem that it took time.
[0010]
Therefore, in the present invention, a good optical coupling efficiency between an optical fiber and an optical semiconductor element can be obtained, and a self-aligning type optical component mounting substrate having a V-groove and a solder dam that can be easily manufactured, and its An object is to provide a manufacturing method and an optical module.
[0012]
[Means for Solving the Problems]
Method of producing an optical component mounting substrate of the present invention, one main surface on the entire surface and forming a first etching resistant film, the mounting groove forming openings and recesses formed in the first etching resistant film on the substrate made of silicon Forming a photoresist pattern having an opening for use, and removing the first etching-resistant film at the portion corresponding to the opening for forming the mounting groove and the opening for forming the recess by dry etching to expose the substrate surface At the same time, a step of forming a recess on the substrate, a step of covering the entire main surface of the substrate including the recess with a second etching resistant film, and the second etching resistance of the portion corresponding to the mounting groove forming opening removing the film, and forming a mounting groove the substrate surface exposed in the mounting groove forming openings by wet etching, the first etching resistant film and the second resistance And wherein the step of removing the etching film, and forming a conductor layer for an optical semiconductor element in the recess, forming a solder layer on the concave inner covered with conductor layers, to include To do.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below in detail with reference to the drawings schematically shown.
[0020]
As shown in FIG. 1, an optical component mounting substrate S1 according to the present invention has an optical fiber 7 (see FIG. 2) as an optical waveguide on a substrate 1 made of a material capable of anisotropic etching such as single crystal silicon. ) In the position where the optical waveguide mounting groove 2 having a V-shaped cross section and the light emitting element 8 (see FIG. 2) and the light receiving element 9 (see FIG. 2), which are optical semiconductor elements, are disposed. It has the conductor layer 4 in which the predetermined part became concave shape. A solder layer 5 for fixing the optical semiconductor element is formed in the recess 3 of the conductor layer 4. A stopper groove 6 is formed by dicing to position the optical fiber 7 by bringing the tip of the optical fiber 7 into contact therewith.
[0021]
Here, in order to obtain insulation between the substrate 1 and the conductor layer 4, the surface of the substrate 1 is covered with a highly insulating oxide film 13, and the conductor layer 4 is formed on the oxide film 13. . Since the oxide film 13 is formed after the recess 3 in the conductor layer and the optical waveguide mounting groove 2 are formed, the entire substrate including the inside of the recess 3 can be covered with the insulating film 13.
[0022]
Also, the patterning of the optical semiconductor element positioning opening 3a (not shown) and the optical waveguide mounting opening 2a (not shown) formed in a part of the conductor layer 4 is performed by a photolithography technique using the same mask. It has a very high relative positional accuracy of 0.5 μm or less.
[0023]
The positioning and fixing of the optical semiconductor element is performed by a recess 3 formed in a part of the conductor layer 4 and a solder layer 5 formed therein. The recess 3 has a very high accuracy with respect to the optical waveguide mounting groove 2, and at the same time, by melting the solder layer 5 in the recess 3, the recess 3 serves to prevent the solder from flowing out (solder dam). Self-alignment mounting using the optical waveguide mounting groove 2 and the recess (solder dam) 3 is possible. In addition, by pressing and fixing the optical semiconductor element from directly above, the height of the optical semiconductor element is determined by the upper surface (substrate surface) of the recess 3, so that the optical semiconductor element can be reliably positioned and fixed. This is shown in FIG.
[0024]
The depth of the recess 3 can be made to an arbitrary depth, but is preferably about 0.1 to 5.0 μm as a depth suitable for positioning and fixing of the optical semiconductor element. The reason is that if the depth of the recess 3 is too shallow, the melted solder may flow out without fulfilling the role of the dam, and the solder layer 5 is usually formed at a maximum of about 5 μm. The depth is about 5 μm maximum accordingly.
[0025]
Further, the shape of the recess 3 does not have to be only one square as shown in FIG. 1, but a plurality of squares can be arranged, a cross shape or the like corresponding to the electrode shape of the optical semiconductor element. It can also be wedge-shaped or circular (see FIG. 4). For example, when a part of the bottom surface of the optical semiconductor element is chipped, the positioning accuracy of the optical semiconductor element is detected by the chipping by positioning with a plurality of concave portions as shown in FIGS. 4B and 4C. In addition, variations in height accuracy can be prevented. Further, by forming the shape as shown in FIGS. 4D, 4E, and 4F so as to coincide with the electrode on the optical semiconductor element side, not only the front-rear and left-right directions can be positioned reliably, but also the optical semiconductor element It is possible to secure a sufficiently large recess area to maintain the connection strength.
[0026]
Below, an example of the manufacturing method of the optical component mounting board | substrate in this invention is demonstrated based on FIG.5 and FIG.6. 5 (1) to (7) are top views (plan views) for explaining a manufacturing process of the optical component mounting substrate, and FIGS. 6A and B (1) to (7) are respectively FIGS. (A) to (7) AA 'line sectional view, BB' line sectional view.
[0027]
In the present invention, as described later, forming a first etching resistant layer on one entire main surface of the substrate made of silicon, the first opening for mounting groove formed on the etching resistant film and the recess formation opening A step of forming a photoresist pattern having the opening, and the first etching-resistant film at portions corresponding to the opening for forming the mounting groove and the opening for forming the recess are removed by dry etching to simultaneously expose the substrate surface. Forming a recess thereon , covering the entire main surface of the substrate including the recess with a second etching resistant film, and removing the second etching resistant film in a portion corresponding to the mounting groove forming opening. step and a step of forming the substrate surface wet etching to mounting groove exposed on the mounting groove forming openings, the first etching resistant film and the second etching resistant It is characterized removing and forming a conductor layer for an optical semiconductor element in the recess, in that it comprises a step of forming a solder layer on the concave inner covered with the conductor layer.
[0028]
For example, as shown in FIGS. 5 (1), 6A, and B (1), first, a substrate 1 made of single crystal silicon having a Miller index of a principal surface capable of anisotropic etching and a (100) plane is prepared. The first etching resistant film (for example, SiNx film) 11 is formed on the entire main surface of the substrate 1 by a thin film forming method such as thermal oxidation, sputtering, plasma CVD, LP-CVD, or a combination thereof. It is formed at 0.1 to 1 μm.
[0029]
Thereafter, an optical waveguide is guided to the first etching-resistant film 2 by using one photomask including an optical waveguide mounting opening 2a pattern for mounting the optical waveguide 7 and an optical semiconductor element positioning opening 3a pattern. Photoresist 14 patterns of the optical waveguide mounting opening 2a for mounting the body 7 and the optical semiconductor element positioning opening 3a are formed.
[0030]
Next, as shown in FIGS. 5 (2), 6A, and B (2), the optical waveguide mounting opening 2a and the optical semiconductor element are formed by RIE (reactive ion etching), CDE (chemical dry etching), or the like. a first etching resistant film 11 corresponding to the portion of the positioning opening 3a is opened, etching is performed over the thickness of the first etching resistant layer 11, attaching a step on the substrate 1. As shown in FIG. 6A (2), the difference between the depth of the step at this time and the thickness of the first etching-resistant film 11 finally becomes the step of the recess 3 for positioning the optical semiconductor element.
[0031]
Next, as shown in FIGS. 5 (3), 6A, and B (3), a second etching resistant film (for example, a silicon nitride (SiNx such as Si3N4) film) 12 is thickened by LP-CVD, plasma CVD, or the like. The thickness is 0.1 to 2 μm.
[0032]
Thereafter, a predetermined region including the optical semiconductor element positioning recess 3 formed above is covered with a second etching resistant film 12 by photolithography and etching, and the second etching resistant film 12 on the optical waveguide mounting opening 2a is covered. Remove.
[0033]
Next, as shown in FIG. 5 (4) and FIGS. 6A and B (4), using a KOH aqueous solution with a solution temperature of 40 to 80 ° C. and 30 to 45% by weight, the difference in etching rate of the crystal plane of the substrate 1 is utilized. Thus, the V-shaped mounting groove 2 in which the {111} plane equivalent to the (111) plane having a low etching rate appears on the side surface of the groove (an inclined surface of about 55 ° with respect to the surface of the substrate 1) is formed. Note that the region of the recess 3 is not etched because the second etching resistant film 12 exists on the upper portion.
[0034]
Thereafter, as shown in FIG. 5 (5) and FIGS. 6A and B (5), after removing the first etching resistant film 11 and the second etching resistant film 12 by etching, the optical waveguide mounting groove 2 and the recess 3 are formed. An insulating film 13 represented by a thermal oxide film is formed on the entire surface of the substrate 1 including the inside by 0.5 to 2 μm.
[0035]
Further, as shown in FIGS. 5 (6), 6A, and 6 (B), the conductor layer 4 is formed by a lift-off method. At this time, the conductor layer 4 is made of an electrode material such as Ti / Pt / Au, Ti / TiN / Pt / Au, Ti / Au, Cr / Ni / Au, Cr / Au, or the like using an electron beam evaporation method or a sputtering method. The thin film is formed to a thickness of about 0.2 to 1 μm. In addition, the said electrode material is described in order of the lower layer / upper layer. Subsequently, a solder layer 5 is formed inside the recess 3 covered with the conductor layer 4.
[0036]
Finally, as shown in FIG. 5 (7) and FIGS. 6A and B (7), the optical waveguide stopper groove 6 is formed by cutting a groove by dicing between the conductor layer 4 and the optical waveguide mounting groove 2. Similarly, the chip is divided by dicing, and the optical component mounting substrate S1 is manufactured.
[0037]
Thus, for example, an optical fiber 7 is mounted as an optical waveguide in the optical waveguide mounting groove 2 formed on the optical component mounting substrate S1, and the light emitting element 8 or the like is formed on the solder layer 5 formed inside the recess 3. The light receiving element 9 is mounted by passive alignment, and the optical coupling between the optical fiber 7 and the optical semiconductor elements 8 and 9 can be performed with very high accuracy. Thereby, the optical module M1 (FIG. 2) in which highly accurate passive alignment is realized can be completed. The accuracy in this case can realize an accurate alignment with almost no error compared to the conventional error (± 0.2 to ± 1.5 μm).
[0038]
Note that the photoresist 14 is spin-coated, for example, before the optical waveguide mounting groove 2 is formed, and after the mounting groove 2 is formed, the photoresist 14 can be uniformly formed by using, for example, a spray coating method. it can. Moreover, about the shape of the recessed part 3, it is not limited to the said example. Further, an optical waveguide such as an optical waveguide having a waveguide formed on the surface layer of the substrate 1 may be provided in place of the optical fiber 7, and the optical semiconductor element may be only the light emitting element 8 or only the light receiving element 9. Good. In addition to the silicon single crystal, the optical component mounting substrate S1 can be made of GaAs single crystal, crystal, resin, ceramics, etc., but the optical waveguide mounting groove 2 can be easily formed with high positional accuracy by anisotropic etching. In this respect, a silicon single crystal is preferable.
[0039]
Thus, according to the optical component mounting substrate of the present invention, the opening of the optical waveguide mounting groove and the opening of the recess for the optical semiconductor element can be formed without misalignment in the same manufacturing process, and the width thereof. It is possible to form high precision with submicron order, and it is possible to provide a substrate for mounting optical components quickly and with high precision. At the same time, since the same process is performed, the complicated process is not required and the process is simplified. Can be
[0040]
Specifically, since it is not necessary to newly perform a thin film forming process, photolithography, and etching process for the solder dam after the optical waveguide groove and the conductor layer are manufactured, the solder dam can be manufactured by a simple manufacturing method. In addition, it is not necessary to form a thin film on the top of the conductor layer, and the conductor layer is formed after the groove for the optical waveguide is formed. No peeling or etch pits occur.
[0041]
In addition, since the recess is manufactured by dry etching, it can handle various shapes such as a circle that cannot be manufactured by wet etching, and at the same time, a shape that accurately reflects the mask pattern can be obtained, and the shape can be collapsed during the manufacturing process. Since there is no deformation, the positional accuracy required for self-alignment mounting does not deteriorate during the process, and the function as a solder dam is not lost.
[0042]
Since the optical semiconductor element is positioned by the above-described recess, the height direction is determined by the substrate surface to press and contact the optical semiconductor element from above, so that the height of the optical semiconductor element due to the solder height deviation is determined. There are no gaps.
[0043]
In addition, since the conductor layer can be formed on the thermal oxide film including the inside of the recess, the insulating property is good. Since the first and second etching resistant films, which are mask films at the time of etching the optical waveguide mounting groove, are all removed before the formation of the insulating film typified by the thermal oxide film, the eaves-like film generated by the etching is contaminated. Thus, a clean substrate surface can be maintained without adhering to the substrate surface.
[0044]
Furthermore, since the optical waveguide and the optical semiconductor element are optically coupled with high accuracy, it is possible to provide an optical module with excellent performance.
[0045]
In addition, this invention is not limited to the above-mentioned embodiment, It can change suitably in the range which does not deviate from the summary of this invention.
[0046]
【Example】
Examples in which the present invention is further embodied will be described below.
[0047]
As the optical component mounting substrate S1, a single crystal silicon substrate having a main surface of (100) and a thickness of 1 mm was used. In this case, the optical waveguide mounting groove 2 can be formed in a V shape by anisotropic etching, and its inclined surface is composed of a {111} plane equivalent to (111).
[0048]
First, a SiNx film serving as the first etching resistant film 11 was formed on the substrate 1 to a thickness of 0.1 μm by the LP-CVD method. Next, a photoresist is applied on the entire surface of the substrate 1 on which the first etching resistant film 11 is formed by spin coating, and a photomask having an optical waveguide mounting opening 2a and an optical semiconductor element positioning opening 3a is formed. Using this, a photoresist 14 pattern was formed.
[0049]
Next, simultaneously with the photoresist 14 pattern, the first etching-resistant film 11 in the optical waveguide mounting opening 2a and the optical semiconductor element positioning opening 3a is etched and removed by an RIE (reactive ion etching) apparatus. The substrate 1 was etched by a depth corresponding to the desired depth of the recess.
[0050]
In this case, the depth of the concave portion 3 is 2 μm when the thickness of the solder layer 5 provided for the placement and fixing of the optical semiconductor element is 2 μm. . By etching the substrate simultaneously with the removal of the first etching-resistant film 11 to form the recesses 3, the recesses 3 that directly reflect the shape of the photomask can be formed without going through complicated steps. Further, since the etching is performed by a dry etching method such as RIE, the etching rate can be easily controlled, and the concave portion 3 having an accurate depth can be obtained.
[0051]
Next, the photoresist 14 pattern was removed, and a SiNx film to be the second etching resistant film 12 was similarly formed to a thickness of 0.1 μm by the LP-CVD method. Since this film is highly resistant to an aqueous solution of potassium hydroxide, which is an etchant when forming the optical waveguide mounting groove 2, and has excellent coverage, the step of the recess 3 can be completely protected from the etchant. After the second etching resistant film 12 was formed, photolithography was performed again to remove the second etching resistant film 12 in the vicinity of the optical waveguide mounting groove opening 2a, and only the recess 3 was covered with the second etching resistant film 12.
[0052]
Next, after removing the photoresist pattern, the substrate 1 was immersed in an aqueous potassium hydroxide solution (43 wt%, 60 ° C.), and the V-groove 2 was formed in the optical waveguide mounting opening 2a by anisotropic etching. Since the light emitting point of the light emitting element 8 is at a height of about 7 μm from the bottom surface of the element, the V groove width is 143 μm so that the optical axis of the optical fiber 7 having an outer diameter of 125 μm is at a height of 7 μm from the substrate.
[0053]
Next, the first and second etching resistant films were removed, and an oxide film 13 serving as an insulating film was formed on the entire substrate 1 by thermal oxidation to a thickness of 0.5 μm.
Thereafter, a photoresist pattern to be a conductor layer pattern is formed on the substrate 1 by spray coating, and a metal film of Ti / Pt / Au (however, in the order of lower layer / upper layer) to be a conductor layer is formed by 0.8 μm by vapor deposition. A conductor layer 4 was formed by a lift-off method.
[0054]
Similarly, 2 μm of Au—Sn alloy solder layer 5 was formed in the recess 3.
[0055]
According to the present embodiment, since the recess 3 is formed simultaneously with the groove patterning on the substrate 1 itself, and then the V-groove 2 is formed by anisotropic etching, the pattern of the recess 3 is accurate and the depth direction is also highly accurate. At the same time that the concave portion was obtained, the shape of the concave portion 3 was not broken and the function as a solder dam was achieved. Further, since the insulating film 13 is then formed on the entire surface of the substrate 1, the insulating property inside the recess 3 can be reliably obtained.
[0056]
Further, as shown in FIG. 2, the self-mounting of the solder 5 in which the light emitting element 8 is formed on the inner conductor layer 4 and the light receiving element 9 is formed on the outer conductor layer 4 of the optical component mounting substrate 1 in the present invention . distribution in alignment mounting after casting, respectively connect a bonding wire, and the optical module M1 by the optical fiber 7 is disposed and fixed with adhesive to the optical waveguide mounting groove 2, to check the validity of the present invention I was able to.
[0057]
【The invention's effect】
As described above in detail, according to the optical component mounting substrate manufactured by the manufacturing method of the present invention, since the optical semiconductor element is accurately positioned by the recess, self-alignment is possible. Further, the height direction of the optical semiconductor element is determined by the substrate surface in order to press and contact the optical semiconductor element from above, so that the optical semiconductor element does not deviate in height due to the solder height deviation.
[0058]
Further, the electrode pattern on the bottom surface of the optical semiconductor element is fitted into the concave portion of the substrate, and self-alignment can be performed more accurately.
[0059]
In addition, by having a solder layer inside the recess, the recess can be used as a solder dam and not only for positioning during self-alignment, but also there is no risk of solder flowing out and contacting other parts.
[0060]
In addition, according to the manufacturing method of the present invention, since the optical waveguide groove and the concave portion are patterned simultaneously with a single mask, the mutual positional accuracy is good and self-alignment using the groove and the concave portion is possible. Since there is no need to perform a new thin film deposition process, photolithography, or etching process for the solder dam after the fabrication of the optical waveguide groove and conductor layer, the solder dam can be fabricated by a simple fabrication method (patterning of grooves and recesses). Sometimes additional etching is used to form a recess, so that it is not necessary to newly perform film formation or photolithography for the recess).
[0061]
In addition, it is not necessary to form a thin film on the top of the conductor layer, and the conductor layer is formed after the groove for the optical waveguide is formed. No peeling or etch pits occur.
[0062]
Since the recess is made by dry etching, it can cope with various shapes such as a circle that cannot be made by wet etching, and at the same time, a shape that accurately reflects the mask pattern is obtained, and the shape is broken or deformed during the production process. Therefore, the positional accuracy required for self-alignment mounting does not deteriorate during the process, and the function as a solder dam is not lost.
[0063]
Since the conductor layer can be formed on the thermal oxide film including the inside of the recess, it has good insulation.
[0064]
Since the first and second etching resistant films, which are mask films at the time of etching the optical waveguide mounting groove, are all removed before the formation of the insulating film typified by the thermal oxide film, the eaves-like film generated by the etching is contaminated. Thus, a clean substrate surface can be maintained without adhering to the substrate surface.
[0065]
Furthermore, according to the optical module using the optical component mounting substrate manufactured by the manufacturing method of the present invention, the optical waveguide and the optical semiconductor element are optically coupled with high accuracy, so that the optical module with excellent performance is obtained. Can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically illustrating an embodiment of an optical component mounting board according to the present invention.
FIG. 2 is a perspective view schematically illustrating an embodiment of an optical module according to the present invention.
FIG. 3 is an enlarged cross-sectional view schematically illustrating an embodiment of an optical component mounting substrate according to the present invention.
FIG. 4 is a top view showing an example of a concave shape according to the present invention.
5 (1) to (7) are top views schematically illustrating a method for manufacturing an optical component mounting board according to the present invention. FIG.
FIGS. 6A and 6B are cross-sectional views schematically illustrating a method for manufacturing an optical component mounting substrate according to the present invention. FIGS.
7A to 7D are cross-sectional views illustrating a conventional method for manufacturing an optical component mounting substrate.
[Explanation of symbols]
1: Substrate 2: V groove (optical waveguide mounting groove)
2a: optical waveguide mounting groove opening 3: recess 3a: recess opening 4: conductor layer 5: solder layer 6: stopper groove 7: optical fiber (optical waveguide)
8: Light emitting element (optical semiconductor element)
9: Light receiving element (optical semiconductor element)
10: Opto-semiconductor element side electrode 11: First etching resistant film 12: Second etching resistant film 13: Insulating film (thermal oxide film)
14: Photoresist

Claims (1)

Forming a first etching-resistant film on the entire main surface of the substrate made of silicon ;
Forming a photoresist pattern having the first for mounting groove formed on the etching resistant film opening and recess formation opening,
Removing the first etching-resistant film at the portion corresponding to the mounting groove forming opening and the recess forming opening by dry etching to expose the substrate surface and simultaneously forming a recess on the substrate;
Covering the entire main surface of the substrate including the concave portion with a second etching resistant film;
Removing the second etching-resistant film in a portion corresponding to the mounting groove forming opening;
Forming a mounting groove the substrate surface exposed in the mounting groove forming openings by wet etching,
Removing the first etching resistant film and the second etching resistant film;
Forming a conductor layer for an optical semiconductor element in the recess,
Forming a solder layer inside the recess covered with the conductor layer;
Method of producing an optical component mounting substrate you comprising a.

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