JP5765178B2 - Optical integrated device, manufacturing method thereof, and optical module - Google Patents

Description

  The present invention relates to an optical integrated device, a manufacturing method thereof, and an optical module.

  In an information device having a plurality of nodes inside such as a server or a router, it is said that in the near future, the transmission capacity between nodes will be 10 to 100 Gbps or more, and the transmission band will be 1 to 10 Tbps class. In this case, interconnection by optical wiring is required instead of the electrical wiring currently used.

  In a system having a transmission capacity between nodes of 100 Gbps or more and a transmission band of 10 Tbps class, it is indispensable to save power and to integrate devices. Such a power-saving and highly integrated system is expected to be realized by so-called silicon photonics technology in which photoelectric conversion elements, optical modulators, and multiplexers / demultiplexers are integrated into a small number of chips.

  An opto-electric integrated chip used for silicon photonics technology is manufactured by a semiconductor process. A clad layer and a silicon fine wire optical waveguide are formed on a silicon substrate, and a grating coupler for optical coupling with an optical fiber is formed at the end of the silicon fine wire optical waveguide.

  By the way, when transmitting an optical signal between nodes, it is desirable to use a single mode fiber that is less affected by waveform deterioration even when transmitted over a long distance. However, when a single mode fiber is used, it is necessary to mount the grating coupler formed in the photoelectric integrated chip with high positional accuracy and angular accuracy.

  Luxtera has commercialized an optical transceiver using silicon photonics technology, and an 8-channel single-mode fiber array is mounted by active alignment on a CMOS Transceiver Die with an 8-channel grating coupler (for example, Patent Document 1). However, special equipment is required for active alignment mounting, and passive alignment mounting technology that can reduce manufacturing cost during mass production is desired.

  As a passive alignment mounting technology, a thick guide structure having an inclination (taper) is formed on an opto-electric integrated chip using a dry film resist, and the optical fiber tip is aligned with the guide structure. A method for aligning an element and an optical fiber has been proposed (see, for example, Non-Patent Document 2). In order to form a thick guide structure, dry film resists are laminated in multiple layers.

  However, when a multilayer guide structure is formed by a dry film resist laminating process, misalignment occurs between the opening side walls of different layers in the photolithography process, and a linear taper cannot be formed.

  For example, in FIG. 1A, an optical waveguide 102 and a grating coupler 103 are formed on a silicon substrate 10, and openings 130 are formed in dry film resists 105 to 109 laminated via a protective layer 104. If the intermediate layer 108 is misaligned, the position and angle of the optical fiber 120 will deviate from the target position and angle even if the distal end of the optical fiber 120 is positioned along the tapered opening 130. . The fiber position P planned in FIG. 1 (A) is inclined at an angle θ from the perpendicular, but when the optical fiber 120 is mounted, as shown in FIG. 1 (B), light is emitted at an angle smaller than the designed inclination angle θ. The fiber 120 is tilted and held in the opening 130.

  In contrast, in FIG. 2, the intermediate layer 107 is displaced, and the optical fiber 120 is held in the opening 130 while being inclined at an angle larger than the designed inclination angle θ. When the inclination angle of the optical fiber 120 is shifted from the original position as shown in FIG. 1B or FIG. 2B, the optical coupling efficiency between the optical waveguide 102 and the optical fiber 120 via the grating coupler 103 increases. It will decline.

  Therefore, when positioning the optical fiber on the opto-electric integrated chip by passive alignment, even if the fiber guide structure is thickly formed by the multi-layer process of dry film resist, it is possible to reduce the positional deviation and inclination angle deviation of the optical fiber. Is desired.

Narashima et al., “An Ultra Low Power CMOS Photonics Technology Platform for H / S Optoelectronic Transceivers at less than $ 1 per Gbps”, Proc. OFC 2010 (2010) Christoph Kopp etal., “Dry-film Technology as a Standard Process for Passive Optical Alignment of Silicon Photonics Devices” Proc. ECTC 2009 (2009)

  Provided are a configuration and a method capable of reducing a positional deviation and an angular deviation of an optical fiber when positioning the optical fiber in an optical integrated device.

In one aspect, the optical integrated device is
An opening that penetrates the multilayer guide layer laminated on the substrate;
An optical fiber that is guided by the opening and optically connected to the light input / output unit formed in the substrate, and the opening has an opening width in a lowermost guide layer and an uppermost guide layer, Narrower than the opening width of the intermediate layer located between the lowermost layer and the uppermost layer,
The optical fiber is in contact with the side wall of the opening of the lowermost guide layer at a first end along the opening width direction, and at the second end opposite to the first end. It contacts the side wall of the opening of the upper guide layer.

  An optical integrated device having an optical fiber guide structure with low connection cost and high connection reliability is realized.

It is a figure which shows the problem of a well-known optical fiber alignment structure. It is a figure which shows the problem of a well-known optical fiber alignment structure. It is the schematic of the electronic device carrying the optical module using the photoelectric integrated chip of embodiment. It is explanatory drawing of the optical fiber positioning structure in the photoelectric integrated chip of embodiment. It is explanatory drawing of the optical fiber positioning structure in the photoelectric integrated chip of embodiment. It is explanatory drawing of the optical fiber positioning structure in the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a manufacturing-process figure of the photoelectric integrated chip of embodiment. It is a figure which shows the structural example which attached the housing for hold | maintaining and protecting an optical fiber. It is a figure of a comparative example.

  Hereinafter, embodiments of the invention will be described with reference to the drawings. FIG. 3 is a schematic diagram of the electronic apparatus 1 on which a plurality of optical modules 10 are mounted. In each optical module 10, an opto-electric integrated chip 20 as an example of an optical integrated device is mounted. The electronic device 1 is a multilayer circuit board used in next-generation information devices provided with an optical interconnection between nodes, and each of the optical modules 10 constitutes a node. The optical module 10 is mounted on the circuit board 2 by solder bumps 15, and the nodes are optically connected using an optical fiber 4. On the edge of the circuit board 2, an optical connector 3 for connection outside the board is disposed, and each node (optical module 10) and the optical connector 3 are optically connected by an optical fiber 4.

  In the optical module 10, electronic components such as an interconnect control chip 12, a logic chip 13, and a memory chip 14 and an optoelectronic integrated chip 20 are mounted on an interposer substrate 11. In the opto-electric integrated chip 20, for example, a clad layer and an optical waveguide are formed on a silicon substrate, and a grating coupler that performs optical coupling with an optical fiber is formed at the end of the optical waveguide. The optical fibers 4 are arranged in, for example, an array, accommodated in the housing 5 and connected to the opto-electric integrated chip 20.

  FIG. 4 is a cross-sectional view showing an optical fiber positioning structure of the opto-electric integrated chip 20 of the embodiment. The opto-electric integrated chip 20 has at least an optical waveguide 22 and a grating coupler 23 formed on a silicon substrate 21. The grating coupler 23 functions as an input / output interface for optical signals from the outside or to the outside. In FIG. 4, although not shown, it is assumed that photoelectric conversion elements, light modulation elements that change the light intensity, and the like are monolithically integrated on the silicon substrate 21.

  A multilayer guide layer 31 including a lowermost layer 25, an intermediate layer 26, a bonding film 27, and an uppermost layer 29 is formed on the substrate 21 on which the grating coupler 23 is formed. The optical fiber 4 is disposed in the opening 30 penetrating the multilayer guide layer 31. The front end surface of the optical fiber 4 faces the grating coupler 23 on the substrate 21 with the protective layer 24 interposed therebetween.

  The opening 30 includes an opening 32 formed in the lowermost layer 25 of the multilayer guide layer 31, an opening 33 formed in the intermediate layer 26, and an opening 34 formed in the uppermost layer 29. The opening width of the opening 33 of the intermediate layer 26 is wider than the opening width of the opening 32 of the lowermost layer 25 and the opening width of the opening 34 of the uppermost layer 29.

  Here, the “aperture width” refers to the aperture size in the direction in which the optical fiber 4 is inclined. In the example of FIG. 4, the optical fiber 4 is inclined rightward on the paper surface, and thus the opening width indicates the opening size in the left-right direction (horizontal direction) of the paper surface. When a plurality of optical fibers 4 are arranged in an array, the optical fibers 4 are arranged in a direction orthogonal to the opening width. Therefore, the fiber arrangement direction is a direction perpendicular to the paper surface of FIG.

  The ends of the optical fiber 4 inserted into the opening 30 are two of the opening end A which is one end side of the opening portion 32 of the lowermost layer 25 and the opening end B which is the other end side of the opening portion 34 of the uppermost layer 29. Positioned with a gentle curvature in contact with the location. In this state, the optical fiber 4 is fixed with an optical adhesive 35 filled in the opening 30.

  FIG. 5 is an explanatory diagram of the opening of the opening 30 of the multilayer guide layer 31. As in FIG. 4, the left-right direction (horizontal direction) of the paper surface is the width direction of the opening 30. The opening 32 of the lowermost layer 25 has an opening width W1 that exposes the grating coupler 23. The opening 33 of the intermediate layer 26 has an opening width W2 wider than W1. The opening 34 of the uppermost layer 29 has an opening width W3 that is narrower than W2.

  In order to incline the optical fiber 4 inserted into the opening 30 as shown in FIG. 4, in FIG. 5, the opening 33 of the intermediate layer 26 has a lowermost layer 25 with respect to the side wall 32 </ b> S of the opening 32 of the lowermost layer 25. Are widened offset to the opening end A side, which is the optical fiber contact side. Further, the opening 33 of the intermediate layer 26 is widened by being offset from the side wall 34S of the opening 34 of the uppermost layer 29 to the opening end B side on the optical fiber contact side of the uppermost layer 29. In other words, the opening 32 of the lowermost layer 25 is offset in the direction in which the optical fiber 4 is inclined with respect to the center of the opening 33 of the intermediate layer 26 (on the right side of the paper in the examples of FIGS. 4 and 5). The opening 34 of 29 is offset in the direction opposite to the direction in which the optical fiber is inclined with respect to the center of the opening 33 of the intermediate layer 26 (the left side of the drawing in the examples of FIGS.

  The relative offset amount between the opening 33 and the openings 32 and 34 is set to be larger than the positional deviation amount of each layer in the step of forming the opening 30. With the opening 30 having such a cross-sectional shape, the inclination of the optical fiber 4 is defined only at two locations, that is, the opening end A of the lowermost layer 25 and the opening end B of the uppermost layer 29 as shown in FIG. The angle deviation from the designed tilt angle can be minimized.

  FIG. 6 is a view for explaining the positioning of the optical fiber 4 using the tool 50. The optical fiber 4 is sucked and fixed to a tool 50 capable of adjusting six axes (x, y, z, θx, θy, θz), and inserted into the opening 30 filled with the optical adhesive 35. When a load is applied to the tool 50 in a direction in which the optical fiber 4 is inclined as indicated by an arrow at a height at which the tip of the optical fiber 4 is in contact with the protective layer 24, the optical fiber 4 is formed on the uppermost layer 29 of the multilayer guide layer 31. It is abutted at two locations of the opening end B and the opening end A of the lowermost layer 25, and is positioned with a gentle curvature.

  For example, when the optical fiber 4 having an outer diameter of 80 μm is used, the B-side side wall 33SB of the opening 33 of the intermediate layer 26 is 5 to 50 μm, more preferably 15 to 25 μm, more than the B-side side wall 34S of the uppermost layer 29. It is arranged offset to the outside. Further, the A-side side wall 33SA of the opening 33 of the intermediate layer 26 is arranged to be offset from the A-side side wall 32s of the lowermost layer 25 by 5 to 50 μm, more preferably 15 to 25 μm.

  In the step of forming the opening 33 in the intermediate layer 26, even if a positional shift of about several μm occurs in each layer in the horizontal direction, the opening side wall 33S of the intermediate layer 26 does not contact the optical fiber 4. Therefore, it is possible to reduce the deviation of the tilt angle of the optical fiber 4 during positioning. Further, since the optical fiber 4 is positioned in contact with the opening end A of the lowermost layer 25 and the opening end B on the opposite side of the uppermost layer 29, it is assumed that a positional deviation occurs in the opening 34 of the uppermost layer 29. However, the shift amount of the holding angle of the optical fiber 4 is smaller than the conventional one.

  7A to 7K are manufacturing process diagrams of the opto-electric integrated chip (optical integrated device) 20 according to the embodiment. 7A to 7K, (A) is a top view and (B) is a sectional view. Hereinafter, an example in which the optical fiber 4 having an outer diameter of 80 μm is used will be described, but the outer diameter of the optical fiber 4 is not limited to 80 μm. The thickness may be larger or smaller than 80 μm, and the thickness of the multilayer guide layer 31 and the size of the opening 30 can be appropriately determined according to the outer diameter of the optical fiber 4. Further, the optical fiber 4 may be either alone or arranged in an array. In the following example, a fiber array in which four optical fibers 4 are arranged in a row will be described as an example.

  First, as shown in FIG. 7A, a silicon fine wire optical waveguide 22 and a grating coupler 23 that functions as an optical interface are formed on the silicon substrate 21 by being connected thereto. An alignment mark 75 for positioning is disposed on the silicon substrate 21. The silicon substrate is formed by arranging a plurality of chip regions on a silicon substrate having an outer diameter of 100 mm and a thickness of 0.3 mm, for example. In FIG. 7A, for convenience of illustration, only a region for one chip is shown.

Next, as shown in FIG. 7B, a protective layer 24 having a thickness of 10 μm is formed so as to cover the entire silicon substrate 21. The protective layer 24 is, for example, spin-coated with “CYTOP ^™ ” (registered trademark) manufactured by Asahi Glass, product number CTX-807MP, dried at 80 ° C. for 60 minutes in the air atmosphere, and then at 180 ° C. for 60 minutes in the air atmosphere. It is formed by curing. Thereafter, unnecessary portions of the protective film 24 are removed by patterning using the RIE method.

Next, as shown in FIG. 7C, a dry film resist having a thickness of 65 μm is laminated on the protective film 24 as a lowermost guide layer 25 and patterned by a photolithography method so that the opening 32 of the lowermost layer 25 is formed. Form. The dry film resist is, for example, “TMMF ^™ S2000” manufactured by Tokyo Ohka Kogyo. This dry film resist is laminated using a roll laminator under conditions of a laminating roll temperature of 110 ° C., a laminating roll speed of 1 m / min, and a laminating roll pressure of 0.3 MPa. Using a contact exposure apparatus (model name: UX3, manufactured by USHIO), the film was exposed at an exposure amount of 400 mJ / cm ² and heated in an oven at 90 ° C. for 5 minutes in a nitrogen atmosphere, and then developed with a developer (product name: PM Thinner). , Developed by Tokyo Ohka Kogyo). Finally, post-baking is performed at 200 ° C. and 60 ° C. in a nitrogen atmosphere using an oven to form the opening 32.

  The opening 32 includes a V-shaped corner 32V as a part of the shape as viewed from above so that the optical fiber can be easily positioned in the horizontal direction. In this example, the opening 32 has a sawtooth planar shape in which V-shaped corners 32V are continuous along the fiber arrangement direction. As described above, the width W1 of the opening 32 is an opening size along the direction in which the optical fiber 4 is inclined. The V-shaped corner 32V of the opening 32 corresponds to the opening end A that receives the end of the optical fiber 4 (see FIGS. 4 and 5).

Next, as shown in FIG. 7D, an opening 33 is formed in the intermediate layer 26 having a thickness of 195 μm in which three dry films having a thickness of 65 μm are stacked. Lamination and patterning are repeated three times using the same dry film as in FIG. 7C. Here, it is also conceivable to form the openings 33 by a single process by sequentially curing and laminating a plurality of dry film resists and then collectively performing an RIE process. However, when O ₂ is used as the reaction gas and the RIE process is performed at a gas pressure of 0.2 Pa, the etching rate is about 0.3 μm per minute. If an opening 33 is to be formed in a dry film resist having a thickness of 200 μm, processing for 11 hours or more is required. That is, the process cost caused by the machine time becomes very high. When using an inductively coupled plasma dry process equipment (ICP-RIE), the etching time is reduced to a fraction of that. However, the resist heat generation due to oxygen ion bombardment is large, and etching and cooling are required to prevent resist deterioration. Must be repeated. When the substrate cooling process is included, the machine time cannot be shortened sufficiently.

  For these reasons, when an opening is formed in the laminated dry resist film, an opening is formed for each layer. If an opening is formed for each layer, positional displacement between layers occurs. However, as described above, the opening width W2 of the intermediate layer 26 has an opening in the lowermost layer 25 so that the optical fiber 4 is not affected by positional displacement. The width W1 is set wider than the opening width W3 of the uppermost layer 29 (see FIG. 5). In the example of FIG. 7D, rectangular openings 33 each having a side increased by 15 μm are formed both in the direction of the width W1 of the openings 32 of the lowermost layer 25 and in the arrangement direction orthogonal thereto. The grating coupler 23 is exposed in the opening 33 through the opening 32 of the lowermost layer 25 and the protective film 24.

  Next, as shown in FIG. 7E, another substrate 51 is prepared. The substrate 51 is a silicon substrate 51 having an outer diameter of 100 mm and a thickness of 0.3 mm. A dry film resist having the same thickness of 65 μm as used in FIGS. 7C and 7D is laminated on the substrate 51 to form the uppermost layer 29. The dry film resist 29 is patterned by a photolithography method to form the opening 34. Similarly to the opening 32 in FIG. 7C, the opening 34 has a sawtooth-like planar shape in which V-shaped corners 34V are continuous along the fiber arrangement direction. However, the direction in which the V-shaped corner 34V is formed is opposite to the direction of the opening 32 in FIG. 7C. The V-shaped corner 34V of the opening 34 of the uppermost layer 29 corresponds to the opening end B (see FIG. 4) with which the optical fiber 4 is brought into contact with the uppermost layer 29.

  Next, as shown in FIG. 7F, a thermal bonding film 27 having a thickness of 20 μm is processed into a predetermined shape using a punching press, and then pasted on the dry film 29 on the substrate 51 using a tape mounter. Thereafter, using a dicing saw, the photoelectric integrated chip 20 is cut into 20 × 20 mm dimensions and separated into individual pieces.

  Next, as shown in FIG. 7G, the individual substrate 51 is flip-chipd with the thermal bonding film 27 facing down on the silicon substrate 21 on which the lowermost layer 25, the intermediate layer 26, and the openings 32 and 33 are first formed. Join. The bonding conditions are, for example, using a flip chip bonder, with a load of 98 N, a head heating temperature of 180 ° C., a pulse heat heating of 180 ° C., and 10 seconds. After the flip chip bonding, the thermal bonding film 27 is thermally cured by heating at 150 ° C. for 2 hours in a nitrogen atmosphere using an oven.

  Next, as shown in FIG. 7H, by using an ICP etching apparatus (model name: E620, manufactured by Panasonic Factory Solution), an etching process is performed at an etching rate of 20 μm / min for 15 minutes to remove only another substrate 51. To do. As a result, an opening 30 that penetrates the multilayer guide layer 31 and exposes the grating coupler 23 via the protective layer 24 is formed.

  Next, as shown in FIG. 7I, an optical adhesive (for example, product number: GA-700H, manufactured by NTT-AT) 35 is filled into the opening 30 with a dispenser.

  Next, as shown in FIG. 7J, the four optical fibers 4 are sucked and fixed to the tool 50 and are collectively inserted into the optical adhesive 30 in the opening 30. The optical fiber 4 is inserted at an angle of 1 to 10 °, for example, 5 °, in the direction opposite to the direction in which the optical fiber is finally tilted and held. In this state, the optical fiber 4 is not in contact with the opening end A of the lowermost layer 25 or the opening end B of the uppermost layer 29.

Next, as shown in FIG. 7K, when the tip of the optical fiber 4 comes into contact with the protective layer 24, a load is applied to the tool 50 in a direction in which the optical fiber 4 is inclined. As a result, the optical fiber 4 is positioned with a gentle curvature by contacting the two ends of the opening end A of the opening 32 of the lowermost layer 25 of the multilayer resist and the opening end B of the opening 34 of the uppermost layer 29. At this position, UV irradiation is performed with a UV spot illumination device at an irradiation intensity of 30 mW / cm ² for 10 minutes to cure the optical adhesive 35. Thereby, the tip of the optical fiber 4 is positioned with high accuracy with respect to the grating coupler 23.

  FIG. 8 shows an example in which a housing 61 for holding and protecting the optical fiber 4 is arranged above the opening 30 of the fiber guide structure. 8A is a top view and FIG. 8B is a cross-sectional view. The housing 61 has an inclined surface 61a on its inner wall for guiding the inclined optical fiber 4 to the outside of the housing. The inside of the housing 61 is filled with an adhesive 62 to fix the optical fiber 4.

  The deviation amount from the design value of the positioning angle of the optical fiber 4 was measured for 10 lots of the opto-electric integrated chip 20 manufactured by the method of FIGS. 7A to 7K. The results are shown in Table 1.

表１の結果から、最適角度に対する角度ずれの標準偏差は０．４度であることが分かる。

From the results in Table 1, it can be seen that the standard deviation of the angle deviation with respect to the optimum angle is 0.4 degrees.

Comparative example

As a comparative example, as shown in FIG. 9, an opto-electric integrated chip in which an opening 130 was formed so that a taper angle of 10 degrees with respect to the vertical direction from the lowermost layer 105 to the uppermost layer 109 was produced. Specifically, a silicon fine wire optical waveguide 102, a grating coupler 103, an alignment mark (not shown), and the like are formed on a silicon substrate 101 having an outer diameter of 100 mm and a thickness of 0.3 mm. Cytop ^™ (registered trademark) (product number: CTX-807P, manufactured by Asahi Glass Co., Ltd.) is spin coated on the entire surface, dried in an air atmosphere at 80 ° C. for 60 minutes, and then heat-cured in an air atmosphere at 180 ° C. for 60 minutes. A protective layer 104 having a thickness of about 10 μm was formed. Next, a dry film resist (model name: TMMF ^TM S2000, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is laminated. The laminating conditions are a laminator, a laminating roll temperature of 110 ° C., a laminating roll speed of 1 m / min, and a laminating roll pressure of 0.3 MPa. Using a contact exposure device (model name: UX3, manufactured by USHIO ELECTRIC CO., LTD.), Exposure at an exposure amount of 400 mj / cm ² , heat treatment at 90 ° C. for 5 minutes, and developer (product name: PM Thinner, manufactured by Tokyo Ohka Kogyo Co., Ltd.) Use and develop in a stainless steel bat for 8 minutes. Then, the lowermost layer 105 and the opening were formed by post-baking in an N ₂ atmosphere at 200 ° C. for 60 minutes using an oven. Here, the wall surface of the opening of the lowermost layer 105 was formed to have a taper angle of 10 degrees with respect to the vertical direction in order to tilt and fix the optical fiber 120. Next, using the same dry film resist as the lowermost layer 105, the intermediate layers 106 to 108 and the uppermost layer 109 were sequentially formed by the same process, and an opening was formed in each. At that time, the wall surfaces of the openings of the intermediate layers 106 to 108 and the opening of the uppermost layer 109 have a taper angle of 10 degrees with respect to the vertical direction, like the openings of the lowermost layer 105, and the lower layer to the upper layer. Toward this, the opening width was gradually increased. That is, the opening width of each layer was adjusted so that the cross-sectional shape of the opening 130 of the multilayer guide layer 110 was a taper shape having a V-shaped cross section as a whole.

  However, due to restrictions on alignment accuracy during exposure, a phenomenon occurs in which the side wall of the opening portion of one layer 107 of the intermediate layer protrudes to the inside of the 5 μm opening 130 from the side wall of the lower layer.

  In this state, when the optical fiber 120 is positioned and fixed so as to follow the cross-sectional shape of the opening 130 using a tool, the optical fiber 120 is aligned with the wall surface of the opening of the lowermost layer 105 and the intermediate layer 107 that is displaced. It was fixed in contact with the wall surface of the opening. For this reason, the inclination angle of the optical fiber was 12.4 degrees. A deviation of 1.4 degrees occurred with respect to the inclination angle of 10 degrees of the optical fiber 120 necessary for the optical fiber 120 to optically couple with the grating coupler 103 with high efficiency. Further, the horizontal position of the tip of the optical fiber 120 is the horizontal position that should be originally positioned because the optical fiber 120 is in contact with the wall surface of the opening of the intermediate layer 107 that has been displaced and the inclination angle is shifted by 1.4 degrees. On the other hand, it was fixed at a position shifted by 8.2 μm on the side opposite to the tilt direction (left side in FIG. 9). For this reason, the optical coupling efficiency between the silicon thin-wire optical waveguide 102 and the optical fiber 120 by the grating coupler 103 is 15%, and only 1/4 optical coupling efficiency is obtained as compared with the optical integrated chip 20 of the embodiment. I understood.

  With respect to 10 lots of the opto-electric integrated chip having the optical fiber guide structure of FIG. As shown in Table 2, the standard deviation of the angle deviation was 0.9 degrees, which was found to be twice or more that of the example.

  As described above, by using the configuration of the embodiment, the positional deviation and the angular deviation can be reduced in the positioning by the passive alignment of the optical fiber 4 with respect to the photoelectric integrated chip 20. As a result, the mounting process cost can be reduced, and the cost reduction of the optical module 10 and the electronic device 1 can be expected due to the mounting process cost reduction.

  The present invention is not limited to the embodiment described above. The V-shaped corner that receives the optical fiber in the opening is not limited to a planar V-shape, and may take any shape such as a U-shape or an arch shape. Further, the offset amounts of the sidewalls of the intermediate layer, the uppermost layer, and the lowermost layer can be appropriately set in consideration of the fiber diameter and the positional deviation amount generated in the photolithography process. Only one of the lowermost layer and the uppermost layer may be offset with respect to the center of the opening of the intermediate layer. In addition, when the optical fiber is positioned with a gentle curvature between the uppermost opening side wall and the lowermost opening side wall, when the intermediate layer has an opening width that does not contact the opening side wall of the intermediate layer, the lowermost layer is not necessarily provided. It is not necessary to offset the opening and the opening of the uppermost layer.

The following notes are presented for the above explanation.
(Appendix 1)
An opening that penetrates the multilayer guide layer laminated on the substrate;
An optical fiber guided by the opening and optically connected to the light input / output unit formed on the substrate;
The opening width in the lowermost guide layer and the uppermost guide layer is narrower than the opening width of the intermediate layer located between the lowermost layer and the uppermost layer,
The optical fiber is in contact with the side wall of the opening of the lowermost guide layer at a first end along the opening width direction, and at the second end opposite to the first end. An optical integrated device that abuts against a side wall of an opening of an upper guide layer.
(Appendix 2)
The optical integrated device according to appendix 1, wherein the lowermost layer opening and the uppermost layer opening are offset in opposite directions with respect to the center of the intermediate layer opening.
(Appendix 3)
The lowermost opening is offset toward the second end with respect to the center of the intermediate layer, and the uppermost opening is closer to the first end with respect to the center of the intermediate layer. The optical integrated device according to appendix 2, which is offset to
(Appendix 4)
The opening of the lowermost guide layer has a first fiber receiving portion for receiving the optical fiber at the first end, and the opening of the uppermost guide layer is formed by the second end. The optical integrated device according to any one of appendices 1 to 3, further comprising a second fiber receiving portion that receives the optical fiber at an end portion.
(Appendix 5)
The optical integrated device according to appendix 4, wherein the opening of the lowermost guide layer and the opening of the uppermost guide layer include polygons facing in opposite directions in a planar shape. .
(Appendix 6)
The optical integrated device according to any one of appendices 1 to 5, wherein the optical fiber is held without being in contact with a side wall of an opening formed in the intermediate layer.
(Appendix 7)
The optical integration according to any one of appendices 1 to 6, wherein the opening width in the intermediate layer is 10 to 100 μm wider than the opening width in the lowermost guide layer and the uppermost guide layer. device.
(Appendix 8)
The light according to any one of appendices 1 to 7, wherein a tip surface of the optical fiber is opposed to the light input portion through a protective film that is light-transmissive with respect to a used wavelength in the opening. Integrated device.
(Appendix 9)
The optical integrated device according to any one of appendices 1 to 8, further comprising a housing that is disposed above the opening and holds the optical fiber.
(Appendix 10)
An optical module in which the optical integrated device according to any one of appendices 1 to 9 and an electronic component are mounted on a relay substrate.
(Appendix 11)
A substrate on which a plurality of optical modules according to appendix 10 are arranged;
An optical connector disposed on an edge of the substrate;
An electronic device in which the optical fiber is connected between the plurality of optical modules or between the optical module and the optical connector.
(Appendix 12)
In the plurality of guide layers stacked on the substrate, the opening width of the lowermost guide layer and the opening width of the uppermost guide layer are set to be narrower than the opening width of the intermediate layer between the lowermost layer and the uppermost layer. And exposing the optical coupling element formed on the substrate in the opening,
Guiding an optical fiber into the opening,
The optical fiber is fixed in contact with a first side wall of the opening in the lowermost layer and a second side wall opposite to the first side wall of the opening in the uppermost layer. Device manufacturing method.
(Appendix 13)
The formation of the opening is
Forming an opening having a first opening width in the lowermost guide layer;
The intermediate layer is disposed on the lowermost guide layer, communicates with the first opening in the intermediate layer, and has an opening having a second opening width wider than the opening width of the first opening Form the
13. The uppermost guide layer having a third opening width that is in communication with the second opening and that is narrower than the second opening width is disposed on the intermediate layer. Manufacturing method of optical integrated device.
(Appendix 14)
13. The optical integrated device according to appendix 12, wherein the lowermost layer opening and the uppermost layer opening are offset from each other in the opposite directions with respect to the center of the intermediate layer opening. Production method.

  It can be used for any optical transmission system such as industrial and public use. As an example, it can be applied to a high-speed transmission path of a server or a high-end computer system.

DESCRIPTION OF SYMBOLS 1 Electronic device 4 Optical fiber 10 Optical module 20 Opto-electric integrated chip (optical integrated device)
21 Silicon substrate (substrate)
22 Optical waveguide 23 Grating coupler (optical input / output unit)
24 Protective layer 25 Lowermost layer of multilayer guide layer 26 Intermediate layer of multilayer guide layer 29 Uppermost layer 30 of multilayer guide layer Opening 32 Lowermost layer opening 33 Middle layer opening 34 Uppermost layer openings 32S, 33SA, 33SB, 34S side wall 32V, 34V V-shaped corner (fiber receiving part)
W1, W2, W3 Opening width

Claims (8)

An opening that penetrates the multilayer guide layer laminated on the substrate;
An optical fiber guided by the opening and optically connected to the light input / output unit formed on the substrate;
The opening width in the lowermost guide layer and the uppermost guide layer is narrower than the opening width of the intermediate layer located between the lowermost layer and the uppermost layer,
The optical fiber, characterized in that the abutment before SL and the side wall of the opening of the lowermost guide layer, a pre-Symbol said first side wall of the opening of the uppermost guide layer and a second side wall opposite Integrated optical device. The opening of the lowermost guide layer and the opening of the uppermost guide layer are offset in opposite directions with respect to the center in the direction along the opening width of the opening of the intermediate layer. The optical integrated device according to claim 1. Wherein the opening of the lowermost guiding layer, the opening in the offset relative to the center of the opening of the intermediate layer on the side of the second side wall, the uppermost guiding layer, the intermediate layer The optical integrated device according to claim 2, wherein the optical integrated device is offset toward the first side wall with respect to the center of the opening . The opening of the lowermost guide layer has a first fiber receiving portion for positioning the optical fiber in a direction parallel to the substrate surface on the first side wall, and the opening of the uppermost guide layer 4. The light according to claim 1, wherein the portion has a second fiber receiving portion that positions the optical fiber in a direction parallel to the substrate surface on the second side wall. Integrated device. The opening of the lowermost guide layer and the opening of the uppermost guide layer include polygons facing in opposite directions in a direction along the opening width in a planar shape. optical integrated device according to any one of claims 1 to 4.   An optical module in which the optical integrated device according to any one of claims 1 to 5 and an electronic component are mounted on a relay substrate. A substrate on which a plurality of the optical modules according to claim 6 are arranged;
An optical connector disposed on an edge of the substrate;
An electronic apparatus comprising: the plurality of optical modules, or the optical module and the optical connector connected by the optical fiber. In the plurality of guide layers stacked on the substrate, the opening width of the lowermost guide layer and the opening width of the uppermost guide layer are set to be narrower than the opening width of the intermediate layer between the lowermost layer and the uppermost layer. And exposing the optical coupling element formed on the substrate in the opening,
Guiding an optical fiber into the opening,
The optical fiber, the a first side wall of the opening of the lowermost guide layer, wherein is brought into contact with a second side wall opposite the first side wall of the opening of the uppermost guide layer is fixed,
The method for manufacturing an optical integrated device, wherein the optical fiber and the optical coupling element are optically connected .

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