JP3855259B2 - Optical waveguide device manufacturing method and substrate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an optical waveguide device and a substrate used therefor, and in particular, an optical waveguide including an inspection process for accurately measuring a horizontal misalignment between an optical fiber V-groove formed on the substrate and the optical waveguide. The present invention relates to a device manufacturing method and a substrate used therefor.
[0002]
[Prior art]
With the recent spread of personal computers and the Internet, information transmission demand is rapidly increasing. For this reason, it is desired to spread optical transmission having a high transmission speed to an end information processing apparatus such as a personal computer. In order to realize this, it is necessary to manufacture a high-performance optical waveguide for optical interconnection at low cost and in large quantities.
[0003]
As materials for optical waveguides, inorganic materials such as glass and semiconductor materials, and resins are known. When manufacturing an optical waveguide from an inorganic material, a method is used in which an inorganic material film is formed by a film forming apparatus such as a vacuum deposition apparatus or a sputtering apparatus, and this is etched into a desired waveguide shape. . However, the vacuum vapor deposition apparatus and the sputtering apparatus require a vacuum exhaust equipment, so that the apparatus is large and expensive. Moreover, since a vacuum exhaust process is required, the process becomes complicated. On the other hand, when an optical waveguide is manufactured from a resin, the film forming process can be performed in an atmospheric pressure by coating and heating, so that there is an advantage that the apparatus and process are simple.
Various resins are known as the optical waveguide and the clad layer, and a polyimide having a high glass transition temperature (Tg) and excellent heat resistance is particularly expected. When the optical waveguide and the clad layer are formed of polyimide, long-term reliability can be expected, and it can withstand soldering.
[0004]
A resinous optical waveguide device is generally configured by providing a V-groove for mounting an optical fiber on a substrate, and further laminating a resinous lower cladding layer, an optical waveguide layer, and an upper cladding layer. . At this time, whether or not the positional deviation (lateral deviation) between the optical fiber mounting V-groove and the optical waveguide in the main plane direction of the substrate is within a predetermined range is determined between the fiber and optical waveguide mounted in the V-groove. This is important for accurate alignment. In addition, when the electrode and the optical waveguide on which the light emitting element and the light receiving element are mounted are mounted on the same substrate, the lateral deviation amount between the optical waveguide and the electrode in the main plane direction of the substrate is within a predetermined range. Whether it is included is equally important.
[0005]
In order to measure the lateral shift amount between the V-groove and the optical waveguide, a method of measuring by the number of pixels of an enlarged image by a microscope or a method of measuring by an eyepiece micrometer is usually used. However, when measuring by the number of pixels, the width of the field of view and the image resolution (pixel density) determine the measurement accuracy. Considering the size of a normal V-groove, if the diameter of the field of view is 400 μm and measurement is performed with a standard image resolution of 500 pixels, the measurement accuracy is 0.8 μm and the measurement accuracy is 0.8 μm. In addition, since the eyepiece micrometer measures by moving the index line on the enlarged image, the driving error (pack crush) of the drive unit that moves the index line becomes a large error, and the objective lens magnification is 40 to 2 to 3 μm. Measurement accuracy. However, since the width of the optical waveguide is several μm, these measurement accuracy is insufficient.
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical waveguide device manufacturing method including an inspection process for accurately measuring a horizontal displacement between an optical fiber-mounted V-groove formed on a substrate and an optical waveguide, and the optical waveguide device used for the method. It is to provide a substrate.
[0007]
[Means for Solving the Problems]
This invention provides the manufacturing method of an optical waveguide device which has the following processes.
A first step of forming a V-groove for mounting an optical fiber and a first alignment mark on a substrate;
A second step of forming a lower cladding layer on the substrate;
A third step of forming an optical waveguide layer on the lower cladding layer;
A resist layer is provided on the optical waveguide layer, and the resist layer is exposed and developed through a photomask having a pattern of a desired optical waveguide and a second alignment mark, and the desired optical waveguide and the second alignment are formed. A fourth step of forming a resist pattern having marks;
Etching the optical waveguide layer using the resist pattern as an etching mask to form a desired optical waveguide and a second alignment mark, and the first alignment mark and the second alignment mark A sixth step of obtaining a positional deviation amount and determining that the positional deviation amount is defective when the positional deviation amount is larger than a predetermined amount.
The present invention also provides a substrate used for manufacturing an optical waveguide device in which a V groove for mounting an optical fiber and a first alignment mark are formed on the substrate.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The structure of the optical waveguide device 100 which is one embodiment of the optical waveguide device of the present invention will be described with reference to FIGS. The optical waveguide device 100 includes a region where an optical waveguide laminate 10 is mounted, a region 20 where a V-groove 21 is disposed, and an electrode 7 for mounting a light emitting element or a light receiving element on a silicon single crystal substrate 1. And a region 30 in which is disposed. The optical waveguide laminate 10 includes the optical waveguide 4, and in this embodiment, the optical waveguide 4 is made of polyimide resin.
[0009]
The structure of the optical waveguide laminate 10 will be further described. A silicon dioxide layer 2 for protecting the substrate 1 and adjusting the refractive index is provided on the upper surface of the substrate 1, and the optical waveguide laminate 10 is formed on the silicon dioxide layer 2. As shown in more detail in FIG. 3, the optical waveguide laminate 10 includes an organic zirconium compound layer 22, a fluorine-free resin layer 23, a lower clad layer 3, which are sequentially laminated on the silicon dioxide layer 2. An optical waveguide 4, an upper cladding layer 5 that embeds the optical waveguide 4, and a protective layer 9 are included. The lower cladding layer 3, the optical waveguide 4 and the upper cladding layer 5 are all made of a polyimide resin containing fluorine. The organic zirconium compound layer 22 and the fluorine-free resin layer 23 are disposed in order to improve the adhesion between the substrate 1 and the lower cladding layer 3.
[0010]
The lower cladding layer 3 and the upper cladding layer 5 are both made of a first polyimide resin film. The film thickness of the lower clad layer 3 is about 6 μm, the film thickness of the upper clad layer 5 is about 10 μm immediately above the optical waveguide 4, and about 15 μm in other portions. The optical waveguide 4 is made of a second polyimide resin film, and the film thickness is about 6.5 μm. The protective layer 9 is a third polyimide resin film, and the film thickness is about 5 μm at the end away from the optical waveguide 4.
[0011]
As the compound constituting the organic zirconium compound layer 22, various compounds can be used, but here, tributoxyacetylacetonate zirconium is used. The organic zirconium compound layer 22 is uniformly formed so that the film thickness falls within the range of 50 angstroms or more and 200 angstroms or less, particularly preferably within the range of 50 angstroms or more and 150 angstroms or less. This is because if the film thickness is thinner than 50 angstroms, the effect of improving the adhesion cannot be exhibited and the lower clad layer 3 may be peeled off from the substrate 1. Further, when the film thickness exceeds 200 angstroms, the film becomes brittle. The range from 50 angstroms to 200 angstroms is substantially equivalent to 5 molecular layers or more and 20 molecular layers or less in terms of the molecular layer (overlapping of molecules) of the organic zirconium compound. The resin layer 23 not containing fluorine is a third polyimide resin layer. The film thickness is about 0.23 μm.
[0012]
The V-groove 21 disposed in the region 20 on the substrate 1 is for mounting an optical fiber. The V groove 21 is designed to have a depth and a width so as to be aligned with the optical waveguide 4 when an optical fiber having a predetermined diameter is mounted. Therefore, for example, when a light emitting element is mounted on the electrode 7, the light emitted from the light emitting element enters the optical waveguide 4, propagates therethrough, is emitted from the optical waveguide 4, and enters the V groove 21. It enters the mounted optical fiber with high efficiency. Further, when the light receiving element is mounted on the electrode 7, when the light propagating through the optical fiber is emitted from the optical fiber, it enters the optical waveguide 4 with high efficiency and propagates therethrough. , Is emitted toward the light receiving element, and is received by the light receiving element.
[0013]
The V groove 21 is a groove having a depth of about 100 μm formed by anisotropic etching of the silicon single crystal substrate 1 and has a V-shaped cross section. At the boundary between the region 20 where the V-groove 21 is disposed and the optical waveguide stack 10, a cut 25 formed when the end surface of the optical waveguide stack 10 is cut as shown in FIGS. 1, 2, and 4. Is present. Similarly, a cut 26 is present at the boundary between the region 30 of the electrode 7 and the optical waveguide laminate 10. Before the notch 25 is formed, the first alignment marks 33 and 34 are arranged, and the alignment marks 31 and 32 are arranged on both sides of the electrode 7 in the region 30. These first alignment marks 31, 32, 33 and 34 are concave portions formed by anisotropic etching at the same time when the V-groove 21 is formed, and the planar shape thereof has two sides parallel to the V-groove. It is preferable to have a square. In this case, the recess formed by anisotropic etching has an inverted pyramid shape.
[0014]
Next, the manufacturing method of the optical waveguide device of the 1st Embodiment of this invention is demonstrated using FIG.
First step of forming V-groove for mounting optical fiber and first alignment mark on substrate A silicon wafer having a diameter of about 12.7 cm is prepared as the substrate 1. A large number of the structures shown in FIG. Thereby, many optical waveguide devices 100 of FIG. 1 can be mass-produced. Therefore, film formation, patterning, and the like are performed on the entire wafer-like substrate 1 at a time.
First, after a silicon dioxide layer 2 is formed on the entire upper surface of the wafer-like substrate 1 by a thermal oxidation method, a vapor deposition method, or the like, a V-groove is formed by photolithography and wet etching utilizing the anisotropy of silicon single crystal. 21 are formed as shown in FIG. At this time, concave portions used as the alignment marks 31, 32, 33, and 34 shown in FIG.
[0015]
A metal film is formed on the wafer-like substrate 1 and patterned to form the electrode 7 of FIG. As a result, as shown in FIG. 5, a large number of V grooves 21 and electrodes 7 are arranged on the wafer-like substrate 1.
Next, the organic zirconium compound layer 22 is formed on the entire wafer-like substrate 1 of FIG. First, an organic zirconium compound solution is applied to the entire substrate 1 by spin coating, and the obtained coating film is dried by heating at 160 ° C. for about 5 minutes to form the organic zirconium compound layer 22. As the organic zirconium compound solution, for example, a solution prepared by dissolving tributoxyacetylacetonate zirconium in butanol to prepare a 1 wt% solution is used.
[0016]
Next, a resin layer forming composition containing no fluorine is applied onto the organic zirconium compound layer 22 by spin coating, the resulting coating film is heated to evaporate the solvent, and further heated to be cured. Thus, the resin layer 23 containing no fluorine is formed. The spin coating conditions are controlled so that the thickness of the resin layer 23 not containing fluorine is 0.23 μm.
Next, on the upper surface of the wafer-like substrate 1, the resin layer 23 that does not contain fluorine, and the organic zirconium for the portions 20 and 30 where the optical waveguide laminate 10 is not disposed in the completed optical waveguide device. The compound layer 22 is removed. Since the optical waveguide devices are arranged vertically and horizontally on the wafer-like substrate 1, the region 20 and the region 30 on the upper surface of the wafer-like substrate 1 are formed of the optical waveguide laminate 10 as shown in FIG. 6. It is a band-shaped part on both sides. By removing the resin layer 23 not containing fluorine and the organic zirconium compound layer 22 from the band-shaped portion, the lower cladding layer 3 is easily peeled off from the substrate 1 in the band-shaped portion. The optical waveguide laminate 10 can be peeled off in a strip shape from the regions 20 and 30 of one region.
[0017]
A method for removing the fluorine-free resin layer 23 and the organic zirconium compound layer 22 from the regions 20 and 30 on the substrate 1 will be specifically described.
First, a resist solution is spin-coated on the entire surface of the wafer-like substrate 1 and dried at 100 ° C. to form a resist film. Thereafter, the image of the photomask is exposed with a mercury lamp. The photomask is formed so that the resist film remains only in the portion where the optical waveguide laminate 10 is to be formed. Thereafter, the resist film is developed. Thereby, not only the resist film but also the resin layer 23 not containing fluorine is wet-etched, and both of them can be almost removed. At this time, since the V-groove 21 and the first alignment marks 31, 32, 33, and 34 have a concave shape, a resist film and a resin layer 23 that does not contain fluorine partially remain at the bottom. Therefore, in this state, exposure is performed again using the photomask described above, and development is performed. As a result, the resist film remaining in the V-groove 21 and the first alignment marks 31, 32, 33, and 34 and the resin layer 23 not containing fluorine can be completely removed.
[0018]
This method has an advantage that the resin layer 23 not containing fluorine can be completely removed from the V-groove 21 and the first alignment marks 31, 32, 33, and 34 by a simple process of repeating exposure and development of the resist film. There is. Thereafter, the organic zirconium compound layer 22 is removed by wet etching using hydrofluoric acid or reactive ion etching. Since the organic zirconium compound layer 22 is very thin, the layers inside the V groove 21 and the first alignment marks 31, 32, 33, 34 can also be removed by wet etching or reactive ion etching. . Finally, the resist film is removed.
[0019]
Second step of forming the lower clad layer on the substrate Next, the first polyimide resin film forming composition (that is, for forming the lower clad layer 3) is formed on the entire upper surface of the wafer-like substrate 1. The composition solution is spin-coated to form a material solution film. Thereafter, the solvent is evaporated by heating at 100 ° C. for 30 minutes and then at 200 ° C. for 30 minutes to evaporate the solvent, followed by heating at 370 ° C. for 60 minutes to cure the lower cladding layer 3 having a thickness of 6 μm. Form.
[0020]
Third step of forming optical waveguide layer on lower clad layer The second polyimide resin film forming composition for optical waveguide layer is spin-coated on the lower clad layer 3. A material solution film is formed. Thereafter, the solvent is evaporated by heating at 100 ° C. for 30 minutes in a dryer, then at 200 ° C. for 30 minutes, and subsequently cured by heating at 350 ° C. for 60 minutes to obtain a thickness 6 that becomes the optical waveguide 4. A second polyimide resin film having a thickness of 5 μm is formed.
[0021]
Fourth step of providing a resist layer on the optical waveguide layer, and exposing and developing to form a resist pattern Next, a silicon-containing resist is formed on the second polyimide resin film (i.e., the optical waveguide layer). A layer (usually about 1 μm in thickness) is provided, and the resist layer is exposed and developed through a photomask having a desired optical waveguide and second alignment mark pattern to form a resist pattern. The exposure is usually performed for 30 seconds to 120 seconds using ultraviolet rays. The development is sufficiently performed in about 90 seconds at room temperature (about 23 ° C.) by spraying an alkaline developer. At this time, the cross-sectional shape of the resist layer on the desired optical waveguide remaining on the unexposed portion without being etched and the second alignment mark forms a trapezoid with an inclination angle of about 80 ° as shown in FIG. Yes. In this step, second alignment marks 41b, 42b, 43b, and 44b are formed on the resist layer.
[0022]
Fifth step of forming optical waveguide and second alignment mark pattern Using the resist pattern as an etching mask, the optical waveguide layer is etched to form a desired optical waveguide 4 and second alignment mark. Marks 41a, 42a, 43a, 44a (see FIG. 10) are formed. Etching is performed by reactive ion etching (O ₂ -RIE) using oxygen ions using the resist pattern as an etching mask. Thereby, as shown in FIG. 6, a large number of optical waveguide devices can be arranged on the substrate 1 and formed at a time.
[0023]
More specifically, in this embodiment, a second alignment mark on the lower cladding layer 3 corresponding to each of the first alignment marks 31, 32, 33, 34 provided on the substrate 1. 41a, 42a, 43a, 44a are formed simultaneously with the optical waveguide 4. Thus, as the second alignment marks 41, 42, 43, 44, the marks 41b, 42b, 43b, 44b shown in FIG. 9 formed in the resist layer in the fourth step may be used. However, the marks 41a, 42a, 43a, and 44a shown in FIG. 10 formed in the optical waveguide layer in the fifth step may be used.
The shape, size, and number of each alignment mark are not particularly limited, but one side is 10 μm to 50 μm, preferably 20 to 20 from the viewpoint of easy formation and easy measurement of misalignment by microscopic observation. A square of about 40 μm, most preferably about 30 μm is desirable.
[0024]
In addition, the first alignment mark and the second alignment mark corresponding to the first alignment mark are not affected by the concave portion of the first alignment mark. From the viewpoint that it is easy to measure the positional deviation between the two, the lateral distance in the plane of the substrate 1 (indicated by α in FIG. 8A) is 10 to 40 μm, preferably 10 to 30 μm. It is desirable to arrange it so that the thickness is about 20 to 25 μm. On the other hand, the first alignment mark and the second alignment mark corresponding to the first alignment mark are preferably arranged with their centers aligned with the longitudinal direction of the substrate. In the case where the centers are arranged to coincide with each other, the lateral deviation amount c can be obtained by the formula described later. However, in the case where the centers are arranged without coincidence, the mismatch amount is calculated with respect to the lateral deviation amount c obtained by the formula described later. Need to be calibrated.
[0025]
A sixth step of judging the quality of the product from the amount of displacement between the first alignment mark and the second alignment mark. Next, the positions of the first alignment mark and the second alignment mark. A deviation amount is obtained, and if the positional deviation amount is larger than a predetermined amount, it is determined as a defective product. As described above, the marks 41b, 42b, 43b, and 44b shown in FIG. 9 formed in the resist layer in the fourth step are used as the second alignment marks 41, 42, 43, and 44, respectively. Alternatively, the marks 41a, 42a, 43a, and 44a shown in FIG. 10 formed in the optical waveguide layer in the fifth step may be used.
However, since the second alignment marks 41b, 42b, 43b, and 44b are formed in the fourth step of forming the resist pattern, the step of obtaining the sixth positional deviation amount is performed after the fourth step. It is desirable to carry out before the fifth step. The reason is as follows.
As shown in FIG. 9a, the second alignment mark 41b (the same applies to 42b, 43b, 44b) formed in the resist layer has a side surface inclined by about 80 ° with respect to the substrate plane. As indicated by the arrows, even if light from above enters the tapered portion 41c, it escapes in the lateral direction and does not return to the inspection machine. For this reason, as shown in FIG. 9b, the tapered portion 41c is observed as a black line, the edge of the alignment mark 41b becomes clearer, and the inspection accuracy is improved to about ± 0.1 μm.
On the other hand, after the resist layer is removed, as shown in FIG. 10a, the second alignment mark 41b is removed and the alignment mark 41a remains, but the side surface of the alignment mark 41a remains on the substrate plane. It is perpendicular to it and has no taper. Further, since the alignment mark 41a has the same color as the lower clad layer 3, the edge of the alignment mark 41a is blurred compared to the edge of the alignment mark 41b. Therefore, the inspection accuracy is about ± 1.0 μm.
[0026]
Here, in the present embodiment, as shown in FIG. 8, a lateral displacement amount c indicating how much the center of the V groove 21 and the center of the optical waveguide 4 are laterally displaced in the plane of the substrate 1 is set. Measure and inspect whether the lateral displacement amount c is within a predetermined range. In the present embodiment, the lateral displacement amount c is measured using, for example, the first alignment mark 31 and the second alignment mark 41 corresponding thereto. Since the V groove and the first alignment mark 31 are concave portions formed by anisotropic etching at the same time, the positional relationship is guaranteed with the accuracy of photolithography. Further, since the second alignment mark 41 and the optical waveguide 4 are exposed and developed with the same mask, the positional relationship is guaranteed with the accuracy of photolithography.
[0027]
Therefore, by measuring the displacement between the first alignment mark 31 and the second alignment mark 41, the lateral displacement amount c between the V groove 21 and the optical waveguide 4 can be measured. Since the second alignment mark 41 is formed above the first alignment mark 31 with a space α in the longitudinal direction, a microscope (for example, a magnification 100 of the objective lens is used until both of them enter the same field of view. The image magnified in step) is taken with a CCD camera. At this time, as shown in FIG. 8A, the second alignment is performed as shown in FIG. 8B by shifting only the focal point at the same position as the image picked up by focusing on the first alignment mark 31. An image taken with the mark 41 in focus is acquired. The distances a and b are obtained from the number of pixels from the image in FIG. 8A, and the distances x and y are obtained from the number of pixels from the image in FIG. And
Lateral displacement c = (a + b) / 2− (x + y) / 2
The lateral shift amount c can be obtained by substituting into the equation.
[0028]
In this embodiment, the interval α between the first alignment mark 31 and the second alignment mark 41 is about 25 μm, and the longitudinal centers thereof are matched, so that FIGS. ) Can be obtained by enlarging the visual field to about 70 μm. Therefore, even when a general CCD camera having an image resolution of 500 pixels is used, the lateral shift amount c can be measured theoretically with an accuracy of 0.14 μm / pixel.
On the other hand, as a comparative example, when the second alignment marks 41, 42, 43, and 44 are not provided, it is necessary to obtain the lateral shift amount c from the field of view image as shown in FIG. When 400 μm is used, when a CCD camera having a general image resolution of 500 pixels is used, the measurement accuracy is theoretically about 0.8 μm / pixel.
[0029]
Thus, in the present invention, the first alignment marks 31, 32, 33, 34 are provided on the substrate 1 when the V-groove 21 is formed, and the second alignment marks 41, 42, 42 are formed when the optical waveguide 4 is formed. By providing 43 and 44 above the first alignment marks 31, 32, 33 and 34, the lateral shift amount c can be measured with high accuracy without using an expensive CCD camera having a large number of pixels. Can do. If the lateral displacement amount c is not within the predetermined range, the product is determined to be defective. Even when the optical waveguide is branched, the lateral displacement amount c can be measured in the same manner for the branched waveguide and the electrode provided corresponding thereto, and a defective product can be determined.
[0030]
Next, the first polyimide resin film-forming composition is spin-coated so as to cover the optical waveguide 4 and the lower cladding layer 3. The obtained material solution film is heated in a dryer at 100 ° C. for 30 minutes, then at 200 ° C. for 30 minutes to evaporate the solvent in the material solution film, and heated at 350 ° C. for 60 minutes to form a first polyimide. An upper cladding layer 5 of the resin film is formed. Furthermore, a polyimide resin film-forming composition containing no fluorine is spin-coated on the upper surface of the upper clad layer 5, and the solvent is evaporated by heating at 100 ° C. for 30 minutes and 200 ° C. for 30 minutes in a dryer, Heating is performed at 350 ° C. for 60 minutes to obtain a protective layer 9 made of a polyimide resin film that does not contain fluorine and has a substantially flat upper surface and a thickness of an end portion away from the optical waveguide 4 of about 5 μm.
[0031]
Next, since the layers from the lower cladding layer 3 to the protective layer 9 are also disposed in the regions 20 and 30 where they are not necessary, they are removed by peeling. That is, as shown in FIG. 6, cuts 25 and 26 are made by dicing at the boundary between the region 20 and the optical waveguide laminate 10 and at the boundary between the optical waveguide laminate 10 and the region 30, respectively. Cut up to 9 layers. At this time, the depth of the cut by dicing is set such that the optical waveguide laminate 10 is cut but the substrate 1 is not cut. In the previous step, the organic zirconium compound layer 22 and the fluorine-free resin layer 23 are removed from the upper surface of the substrate 1 in the regions 20 and 30, so that the lower cladding layer 3 and the substrate are removed in the regions 20 and 30. The adhesion with 1 is small. Therefore, each layer between the lower clad layer 3 and the protective layer 9 mounted on the region 20 and the region 30 can be easily peeled off from the wafer-like substrate 1 by forming the cuts 25 and 26. Can do. Thereby, in the wafer-like substrate 1 of FIG. 6, the upper surface (silicon dioxide layer) of the substrate is exposed in the regions 20 and 30.
[0032]
Next, the wafer-like substrate 1 is cut by dicing as shown in FIGS. 7A and 7B to be cut into strips, and the strip-like substrate is further cut as shown in FIGS. 7C and 7D. 1 is cut into individual optical waveguide devices 100 by dicing, and the optical waveguide device 100 is completed. The procedure of the dicing process for cutting the substrate 1 is not limited to this procedure, and the optical waveguide device 100 is diced into a mesh shape vertically and horizontally in the process of FIG. 7A, as shown in FIG. It is also possible to form
In the optical waveguide device of the present embodiment, the optical waveguide 4 has a linear shape, but the shape of the optical waveguide 4 of the optical waveguide laminate 10 is not limited to the linear shape in accordance with the function required as the optical waveguide device. A desired shape such as y-branch or x-type can be obtained. Moreover, it is also possible to make it the structure provided with the V groove 21 and the electrode 7 according to the shape of an optical waveguide.
[0033]
In addition, the optical waveguide device 100 manufactured in the present embodiment has a high Tg and excellent heat resistance because all layers from the lower cladding layer 3 to the upper cladding layer 5 are formed of polyimide resin. Therefore, the optical waveguide device of the present embodiment can maintain the propagation characteristics even when the temperature becomes high. In addition, since the polyimide resin can withstand a high temperature process such as soldering, it is possible to solder another optical waveguide device, an electric circuit element, or a light emitting element on the optical waveguide device.
[0034]
In the manufacturing method of the optical waveguide device 100 of the present invention, the positional deviation between the V-groove 21 and the optical waveguide 4 is measured with high accuracy in the inspection process, and only those having a positional deviation amount within a predetermined range are regarded as non-defective products. . Therefore, by manufacturing the optical communication device using the optical waveguide device 100 manufactured by the manufacturing method of the present invention, the optical fiber and the optical waveguide 4 can be easily aligned, and the high-performance optical communication device with high coupling efficiency. Can be manufactured at low cost.
In the present invention, an optical waveguide device means a substrate, an inorganic material such as glass or quartz, a semiconductor such as silicon, gallium arsenide, aluminum, or titanium, a metal material, a polymer material such as polyimide or polyamide, or these materials. Using a composite material, these substrates are provided with an optical waveguide, and further, an optical multiplexer, optical waveguide, optical attenuator, optical diffractor, optical amplifier, optical interferometer, optical It refers to a filter, an optical switch, a wavelength converter, a light emitting element, a light receiving element or a combination of these. A semiconductor device such as a light emitting diode or a photodiode or a metal film may be formed on the substrate, and a silicon dioxide film is applied on the substrate as described above for the purpose of protecting the substrate or adjusting the refractive index. Alternatively, a film of silicon nitride, aluminum oxide, aluminum nitride, tantalum oxide, or the like may be formed.
[0035]
【The invention's effect】
According to the present invention, there is provided a method of manufacturing an optical waveguide device in which a V-groove for mounting an optical fiber and an optical waveguide are mounted on a substrate, and an optical process including an inspection process capable of accurately measuring the alignment between the V-groove and the optical waveguide. A method for manufacturing a waveguide device can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic optical waveguide device 100 according to an embodiment of the present invention.
2 is a cross-sectional view taken along the line AA ′ of the optical waveguide device of FIG. 1. FIG.
3 is a cross-sectional view of the optical waveguide device of FIG. 1 taken along the line BB ′.
4 is a plan view of the optical waveguide device of FIG. 1. FIG.
FIG. 5 is a plan view of a wafer-like substrate 1 for explaining a method of manufacturing an optical waveguide device according to an embodiment of the present invention.
FIG. 6 is a plan view of a wafer-like substrate 1 for explaining a method of manufacturing an optical waveguide device according to an embodiment of the present invention.
7A to 7D are explanatory views showing a process of cutting out a wafer-like substrate 1 in the method of manufacturing an optical waveguide device according to one embodiment of the present invention.
FIGS. 8A and 8B are partially enlarged views of FIG. 4, where FIG. 8A is a state where the first alignment mark 31 is focused on the objective lens, and FIG. 8B is a second view. It is explanatory drawing which shows the state which adjusted the focus of the objective lens to this alignment mark 41.
9A is a drawing showing a cross-sectional shape of a second alignment mark 41b provided on the optical waveguide layer 4. FIG.
(B) is a plan view of the second alignment mark 41b.
10A is a drawing showing a cross-sectional shape of a second alignment mark 41a provided on the lower cladding layer 3. FIG.
(B) is a plan view of the second alignment mark 41a.
[Explanation of symbols]
1: silicon substrate, 2: silicon dioxide layer, 3: lower clad layer, 4: optical waveguide, 5: upper clad layer, 7: electrode, 9: protective layer, 10: optical waveguide laminate, 20: optical fiber mounting region , 21: V groove, 22: Organic zirconium compound layer, 23: Resin layer not containing fluorine, 30: Electrode mounting region, 31, 32, 33, 34: First alignment mark, 41a, 42a, 43a, 44a : Second alignment mark provided on the optical waveguide layer, 41b, 42b, 43b, 44b: second alignment mark provided on the resist layer, 41c: taper portion of the second alignment mark 41b

Claims (5)

A first step of forming a V-groove for mounting an optical fiber and a first alignment mark on a substrate;
A second step of forming a lower cladding layer on the substrate;
A third step of forming an optical waveguide layer on the lower cladding layer;
A resist layer is provided on the optical waveguide layer, and the resist layer is exposed and developed through a photomask having a pattern of a desired optical waveguide and a second alignment mark, and the desired optical waveguide and the second alignment are formed. A fourth step of forming a resist pattern having marks;
Etching the optical waveguide layer using the resist pattern as an etching mask to form a desired optical waveguide and a second alignment mark; and a step of forming the first alignment mark and the second alignment mark. positional displacement amount determined, if the positional displacement amount is larger than the amount determined in advance have a a sixth step of determining as defective,
The method of manufacturing an optical waveguide device, wherein the first alignment mark and the second alignment mark are formed corresponding to each of a plurality of optical waveguide devices arranged on a substrate .   The method for manufacturing an optical waveguide device according to claim 1, wherein the sixth step is performed after the fourth step and before the fifth step.   The method for manufacturing an optical waveguide device according to claim 1, wherein the sixth step is performed after the fifth step and after the resist pattern is removed.   The method for manufacturing an optical waveguide device according to any one of claims 1 to 3, wherein a distance in a horizontal direction in the substrate surface between the first alignment mark and the second alignment mark corresponding to the first alignment mark is 10 to 40 µm. .   The method for manufacturing an optical waveguide device according to any one of claims 1 to 4, wherein the planar shape of the first alignment mark and the second alignment mark is a square having two sides parallel to the V-groove.

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