Optical fiber array unit

Abstract

An optical fiber array unit is provided. The optical fiber array unit comprises a substrate, a plurality of optical fiber grooves and a plurality of light guide elements. The substrate has a first region and a second region which are continuous and connected. An optical fiber groove is formed in the first region. The light guide element is formed in the second area. The plurality of optical fiber grooves are respectively aligned with the plurality of light guide elements.

Description

Technical Field

[0001] The embodiment of the utility model relates to a semiconductor photonic system, and in particular to an optical fiber array unit for the semiconductor photonic system. Background Art

[0002] One technology for signal transmission and processing is electrical signaling and processing. In addition, in recent years, optical signaling and processing has been used in an increasing number of applications, particularly due to the use of optical fiber-related applications for signal transmission.

[0003] Optical signal transmission and processing are often combined with electrical signal transmission and processing to provide sophisticated applications. For example, optical fibers can be used for long-distance signal transmission, while electrical signals can be used for short-distance signal transmission, processing, and control. Consequently, devices integrating optical and electrical components have emerged for converting optical and electrical signals and processing them. Accordingly, a package (also referred to as a photonic package) may include a photonic die containing an optical device and an electronic die containing an electronic device (also referred to as a photonic package).

[0004] A fiber array unit (FAU) may include a plurality of grooves, each of which has an optical fiber secured therein and may be used to optically couple light from a light source to the optical fiber, and optically couple light from the optical fiber to an optical coupler within a photonic die of a photonic package. Optical adhesive is typically used to attach the FAU to the photonic package. After the optical adhesive is dispensed between the FAU and the photonic package, the optical adhesive may be cured, for example, by ultraviolet (UV) curing. Summary of the Invention

[0005] Some embodiments of the present invention provide a fiber array unit. The fiber array unit includes a substrate, a plurality of fiber grooves, and a plurality of light guiding elements. The substrate has a first region and a second region that are continuous and connected. The fiber grooves are formed in the first region. The light guiding elements are formed in the second region, wherein the fiber grooves are aligned with the light guiding elements.

[0006] In one embodiment, the optical fiber grooves are formed on an upper surface of the substrate and recessed from the upper surface.

[0007] In one embodiment, the optical fiber grooves are a plurality of silicon through-holes (TSVs) formed in a silicon substrate, and the silicon substrate is placed on the substrate comprising glass material.

[0008] In one embodiment, the light guide elements include:

[0009] a plurality of waveguides extending from an end of the second region adjacent to the optical fiber grooves to an opposite end of the second region away from the optical fiber grooves; and

[0010] At least one reflector is disposed near an end of each of the waveguides opposite to the optical fiber grooves.

[0011] In one embodiment, the waveguides are formed in one or more dielectric layers above an upper surface of the substrate, and the at least one reflector is formed at an end of the one or more dielectric layers opposite to the optical fiber grooves.

[0012] In one embodiment, the waveguides are formed in the substrate below an upper surface of the substrate.

[0013] In one embodiment, the at least one reflector is formed on the upper surface of the substrate near the end of each waveguide opposite to the optical fiber grooves.

[0014] In one embodiment, the at least one reflector is formed in the substrate near the end of each waveguide opposite to the optical fiber grooves.

[0015] Some embodiments of the present invention provide a fiber array unit. The fiber array unit includes a substrate, a plurality of fiber grooves, a plurality of waveguides, and at least one reflector. The substrate has a first region and a second region that are continuous and connected. The fiber grooves are formed in the first region. The waveguides are formed in the second region and aligned with the fiber grooves, wherein no adhesive is formed between one of the waveguides and the corresponding one of the fiber grooves. The at least one reflector is formed at an end of the second region opposite the fiber groove.

[0016] In one embodiment, each of the optical fiber grooves extends along a first direction, the first region and the second region are arranged along the first direction; and each of the waveguides extends along the first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following detailed description, taken in conjunction with the accompanying drawings, will provide a better understanding of the concepts of the embodiments of the present invention. It should be noted that, in accordance with standard industry practice, the various features in the drawings are not necessarily drawn to scale. In fact, the dimensions of various features may be arbitrarily enlarged or reduced for clarity of illustration.

[0018] Figure 1A 、 Figure 1B and Figure 1C Various views of a fiber array unit are shown according to some embodiments.

[0019] Figure 2A 、 Figure 2B and Figure 2C Various views of a fiber array unit are shown according to some embodiments.

[0020] Figure 2B-1 and Figure 2B-2 show Figure 2B Some variations of the fiber array unit in FIG.

[0021] Figure 3A 、 Figure 3B and Figure 3C Various views of a fiber array unit are shown according to some embodiments.

[0022] Figure 4 A flow chart showing a method of forming a fiber array unit according to some embodiments.

[0023] Figure 5A 、 Figure 5B and Figure 5C Various views of a fiber array unit are shown according to some embodiments.

[0024] Figure 6A 、 Figure 6B and Figure 6C Various views of a fiber array unit are shown according to some embodiments.

[0025] Figure 7A 、 Figure 7B and Figure 7C Various views of a fiber array unit are shown according to some embodiments.

[0026] Figure 8 A flow chart showing a method of forming a fiber array unit according to some embodiments.

[0027] Figures 9 to 12 Cross-sectional views showing intermediate steps in forming a photonic package according to some embodiments.

[0028] Figures 13 and 14 Cross-sectional views illustrating intermediate steps in forming a semiconductor package according to some embodiments.

[0029] Figures 15 to 17 Cross-sectional views showing intermediate steps in forming a photonic system according to some embodiments.

[0030] Description of reference numerals:

[0031] 10: Wafer

[0032] 11: Line

[0033] 20: Wafer

[0034] 21: Line

[0035] 100: Photonic Packaging

[0036] 110: Electronic grains

[0037] 111: Substrate

[0038] 112: Interconnection Structure

[0039] 113: Dielectric layer

[0040] 115: Conductive thread

[0041] 117: Conductive vias

[0042] 118: Die Connector

[0043] 119: Dielectric Materials

[0044] 120: Photonic Grains

[0045] 122: Interconnection Structure

[0046] 123: Dielectric layer

[0047] 125: Conductive thread

[0048] 127: Conductive vias

[0049] 128: Die Connector

[0050] 131: Dielectric layer

[0051] 132: Contact

[0052] 133: Conductive thread

[0053] 135: Conductive vias

[0054] 136: Waveguide

[0055] 137: Photon Components

[0056] 138: Grating Coupler

[0057] 139: Nitride waveguide

[0058] 145: Conductive bump

[0059] 150: Semiconductor packaging

[0060] 151: Carrier

[0061] 152: Electronic grains

[0062] 153: Substrate

[0063] 155: Die Connector

[0064] 157: Molding material

[0065] 160: Redistribution Structure / Interconnection Structure

[0066] 161: Dielectric layer

[0067] 163: Conductive thread

[0068] 165: Conductive vias

[0069] 167: Conductive bump

[0070] 169: Line

[0071] 200: Photonic Systems

[0072] 201: Substrate

[0073] 203: Conductive pad

[0074] 205: Conductive structure

[0075] 207: Bottom filling material

[0076] 209: External connector

[0077] 211: Lid

[0078] 212: Opening

[0079] 213: Adhesive materials

[0080] 215: Thermal interface materials

[0081] 217: Optical adhesive

[0082] 300: Fiber Array Unit / FAU

[0083] 301: Fiber Optic

[0084] 302: Lid

[0085] 303: Substrate / Glass Substrate / Base Plate

[0086] 303A: First end

[0087] 303B: Second end

[0088] 303C: upper surface

[0089] 303': Glass substrate / glass support

[0090] 303”: Glass substrate

[0091] 304: Optical adhesive

[0092] 305: Fiber optic groove

[0093] 306: Waveguide structure

[0094] 307: Waveguide

[0095] 308: Dielectric layer

[0096] 309: Reflector

[0097] 400: Fiber Array Unit / FAU

[0098] 409: Reflector

[0099] 410: Waveguide

[0100] 411: Waveguide

[0101] 500: Fiber Array Unit / FAU

[0102] 600: Fiber Array Unit / FAU

[0103] 603: Silicon substrate

[0104] 605:Through Silicon Via

[0105] 606: Line

[0106] 607: Dashed Line

[0107] 700: Fiber Array Unit / FAU

[0108] 800: Fiber Array Unit / FAU

[0109] 1000: Method

[0110] 1010,1020: Operation

[0111] 2000: Methods

[0112] 2010, 2020, 2030: Operation

[0113] S: Arrow

[0114] P, P': pitch

[0115] R1: First Area

[0116] R2: Second Area

[0117] T, T': thickness

[0118] W, W': maximum width

[0119] X, Y, Z: axis

[0120] A-A': line

[0121] B-B': line DETAILED DESCRIPTION

[0122] The following disclosure provides many different embodiments or examples for implementing different features of the embodiments of the present invention. The following describes specific examples of components and configurations to simplify the description of the embodiments of the present invention. Of course, these specific examples are only exemplary and are not intended to limit the embodiments of the present invention. For example, in the following description, it is mentioned that the first feature is formed on or above the second feature, which means that it may include an embodiment in which the first feature and the second feature are in direct contact, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature, so that the first feature and the second feature may not be in direct contact. In addition, the present invention may repeat reference symbols and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself limit the relationship between the various embodiments and / or configurations described.

[0123] Furthermore, spatially relative terms, such as "below," "beneath," "lower," "above," "upper," and the like, may be used herein to describe the relationship of one element or feature to another element or feature illustrated in the drawings. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. The system may be oriented differently (rotated 90 degrees or at other orientations), and the spatially relative terms used herein should be interpreted accordingly.

[0124] According to some embodiments of the present invention, a photonic system including a fiber array unit (FAU) and a method for forming the same are provided, wherein the FAU can optically couple an optical fiber to a photonic die within a semiconductor package. In some embodiments of the present invention, the supporting substrate of the FAU is an ultraviolet (UV)-transparent substrate that allows UV light to pass through during a curing process to cure the optical glue used to secure the FAU to the semiconductor package. In some embodiments, the FAU integrates optical fiber grooves and optical waveguide elements (e.g., waveguides and / or reflectors) on a single supporting substrate, which eliminates the need for additional assembly alignment between the optical fiber grooves and the optical waveguide elements, thereby reducing the number of steps in manufacturing the FAU. In addition, since the bonding interface (e.g., optical glue) between the optical fiber grooves and the optical waveguide elements is omitted, the optical performance of the FAU can be improved.

[0125] The embodiments discussed herein provide examples of the subject matter of the present invention that can be implemented or used, and those skilled in the art will readily appreciate that modifications can be made while remaining within the intended scope of the various embodiments. In the various views and illustrative embodiments, like reference symbols are used to indicate like elements.

[0126] refer to Figure 1A 、 Figure 1B and Figure 1C , which shows various views of a fiber array unit (FAU) 300 according to some embodiments. Figure 1A Showing a top view of FAU 300, Figure 1B Display edge Figure 1A A cross-sectional view of the FAU 300 taken along line AA' in FIG. Figure 1C Display edge Figure 1A 300 is a cross-sectional view of the FAU 300 taken along line BB' in FIG. It should be noted that for simplicity, not all details of the FAU 300 are shown in all figures. For example, the cover 302 and optical glue 304 included in the FAU 300 are omitted in these figures (but are shown in FIG. Figure 17 ), and only in Figure 1C An optical fiber 301 is shown in FIG.

[0127] like Figure 1A 、 1B As shown in FIG and 1C , the FAU 300 includes a (support) substrate 303 configured to support and hold the optical fiber 301. The substrate 303 may have a rectangular shape in plan view (see FIG Figure 1A ) and the rectangular shape in the cross-section (see Figure 1B and 1C ), although other shapes may also be used. The substrate 303 has opposite first and second ends (303A and 303B) in its longitudinal direction (e.g., the X-axis direction shown in the figure), wherein the second end 303B is adjacent to the semiconductor package 150 to which the FAU 300 is to be attached (e.g., see Figure 17 ). Furthermore, the substrate 303 has a first region R1 for arranging the optical fiber groove 305 and a second region R2 for arranging the optical waveguide elements (e.g., the waveguide 307 and the reflector 309), wherein the first region R1 and the second region R2 are arranged along the longitudinal axis of the substrate 303 (e.g., the X-axis direction shown in the figure) and are connected to each other. The first region R1 is proximal to the first end 303A, and the second region R2 is proximal to the second end 303B. In some cases, the thickness T of the substrate 303 can be in a range between 100 μm and 2000 μm, although smaller or larger thicknesses can also be used.

[0128] The substrate 300 may include a grating coupler 138 for the photonic die 120 that fits within the semiconductor package 150 (see, for example, Figure 12 ) and the optical fiber 301. As described above, in some embodiments, the substrate 300 includes a UV-transparent material (e.g., glass) to allow UV light to pass through to cure the optical adhesive 217 during the curing process (e.g., see Figure 17 ). Other suitable materials may also be used in other embodiments, such as sol-gel glass that allows light (e.g., UV light) to pass through or UV-transparent polymers (e.g., PDMS, SU8, PMMA, etc.).

[0129] A plurality of fiber grooves 305 (e.g., recesses) are formed in the substrate 303 (e.g., formed on the upper surface 303C of the substrate 303). The fiber grooves 305 are provided in the first region R1 of the substrate 303 (e.g., extending from one end of the first region R1 to the opposite end, as shown in FIG. Figure 1A and 1B ), and are parallel to each other. For example, in the plan view (see Figure 1A ), each optical fiber groove 305 may extend along the longitudinal axis of the substrate 303 (e.g., the X-axis direction shown in the figure), and these optical fiber grooves 305 are arranged in parallel in a direction perpendicular to the longitudinal axis (e.g., the Y-axis direction shown in the figure). The optical fiber grooves 305 may be designed to have a size (e.g., maximum width W) and a spacing (e.g., pitch P) corresponding to the size (e.g., diameter) and spacing (e.g., pitch) of the optical fibers. In some embodiments, each optical fiber groove 305 has a size (e.g., maximum width W) and a spacing (e.g., pitch P) corresponding to the size (e.g., diameter) and spacing (e.g., pitch) of the optical fibers. Figure 1C A V-shaped cross-section is shown in FIG, although other suitable cross-sectional shapes (eg, U-shaped) may be used.

[0130] In some embodiments, the optical fiber groove 305 is formed using an imprinting process. For example, when the substrate 303 is made of glass, the temperature of the imprinting process should be higher than the glass transition temperature (Tg) of the glass used to form the optical fiber groove 305. In other embodiments, other processes suitable for forming the optical fiber groove 305 in the substrate 300 (e.g., a glass substrate) may also be used, such as molding, mechanical cutting, laser cutting, chemical etching, etc.

[0131] The waveguide structure 306 is formed on the substrate 303. The waveguide structure 306 includes a plurality of waveguides 307 formed (e.g., embedded) in one or more dielectric layers 308 on the upper surface 303C of the substrate 303. The waveguide structure 306 is disposed in the second region R2 of the substrate 303 (e.g., extending from one end of the second region R2 to the opposite end, such as Figure 1A and 1B In the plan view (see Figure 1A ), the waveguides 307 (of the waveguide structure 306) are parallel to each other and aligned in a one-to-one manner with the fiber grooves 305. In addition, although not shown, the waveguides 307 are positioned so that the core of each optical fiber 301 (held by the fiber groove 305) is aligned with the corresponding waveguide 307 in a cross-sectional view (i.e., they are at the same vertical height) to allow optical coupling between the optical fibers 301 and the corresponding waveguides 307.

[0132] In some embodiments, the refractive index of the material of waveguide 307 is higher than the refractive index of the material of dielectric layer 308. For example, waveguide 307 may comprise silicon nitride, and dielectric layer 308 may comprise silicon oxide. However, other suitable materials for waveguide 307 and dielectric layer 308 may also be used.

[0133] The one or more dielectric layers 308 can be formed by any acceptable deposition process, such as spin coating, chemical vapor deposition (CVD), lamination, or the like, or a combination thereof. In some embodiments, the waveguide 307 is a nitride (e.g., silicon nitride) waveguide formed by patterning a silicon nitride layer using acceptable photolithography and etching processes. It should be noted that silicon nitride has a higher dielectric constant than silicon, and thus a nitride waveguide can have greater internal confinement of light than a silicon waveguide. This can also make the performance or leakage of the nitride waveguide less sensitive to process variations, less sensitive to dimensional uniformity, and less sensitive to surface roughness (e.g., edge roughness or line width roughness).

[0134] One or more (light) reflectors 309 are formed on an end portion of the waveguide structure 306 proximate to the second end 303B of the substrate 303. The one or more reflectors 309 are used to guide (e.g., redirect) light from the waveguide 307 to a corresponding grating coupler 138 within the semiconductor package 150, or vice versa. Figures 1A to 1C One reflector 309 is shown, but in other embodiments (e.g., see Figures 3A to 3C), the FAU 300 may include more individual reflectors 309 corresponding to the number of waveguides 307. In some embodiments, the reflector 309 has a planar structure that is tilted relative to the upper surface 303C (for example, forming an inclination angle of about 30 degrees to 60 degrees, such as 45 degrees, with respect to the upper surface 303C). Figure 1B In other embodiments, the reflector 309 may alternatively have a curved cross-section (e.g., see Figures 2A to 2C 、 Figure 2B-1 、 Figures 3A to 3C 、 Figures 6A to 6C 、 7A to 7C ). In the various embodiments discussed herein, inclined profiles and curved profiles may be used interchangeably.

[0135] The one or more reflectors 309 can be formed by forming one or more reflective surfaces (not separately labeled) at the end of the waveguide structure 306 opposite the optical fiber 301, and then forming one or more reflective coatings on the one or more reflective surfaces. In some embodiments, the one or more reflective surfaces can be formed using any acceptable process, such as stamping, molding, mechanical cutting, laser cutting, chemical etching, etc. In some embodiments, the one or more reflective coatings can be a single layer of metal, and the metal materials used include gold (Au), silver (Ag), copper (Cu), aluminum (Al), titanium (Ti), tantalum (Ta), etc., their alloys, or combinations thereof. Alternatively, the one or more reflective coatings can be a multilayer structure including multiple sublayers, each sublayer formed from the above-mentioned metal materials or other suitable dielectric materials (e.g., silicon oxide (SiO2), hafnium oxide (HfO2), tantalum oxide (Ta2O5), titanium oxide (TiO2), silicon nitride (SiN), amorphous silicon, etc.). The one or more reflective coatings may be formed using any acceptable process, such as CVD, physical vapor deposition (PVD), atomic layer deposition (ALD), or other suitable deposition processes.

[0136] Through the above configuration, the FAU 300 integrates the fiber groove 305, the waveguide 307, and the reflector 309 on a single / monolithic substrate 303. In this way, no additional assembly alignment is required between the fiber groove 305 and the light-guiding elements (e.g., 307 and 309), thereby reducing the number of steps in manufacturing the FAU 300. Since the bonding interface (e.g., optical glue) between the fiber groove and the light-guiding elements is omitted, the optical performance of the FAU 300 can also be improved. In addition, in some cases, the substrate 303 can be a UV-transparent substrate, such as a glass substrate (and the waveguide structure 306 is made of a UV-transparent material) to allow UV light to pass through during the curing process to cure the optical glue 217 (see Figure 17 ).

[0137] Figures 2A to 2C 、 Figure 2B-1 、 Figure 2B-2 、 Figures 3A to 3C 、 Figures 5A to 5C 、 Figures 6A to 6C and 7A to 7C Various views of a FAU according to some alternative embodiments are shown. It should be noted that the figures with the letter A in these figure numbers show a top view of the FAU, the figures with the letter B in the same figure numbers show a cross-sectional view of the FAU taken along line AA' in the figure with the letter A in the same figure numbers, and the figures with the letter C in the same figure numbers show a cross-sectional view of the FAU taken along line BB' in the figure with the letter A in the same figure numbers.

[0138] Now refer to Figures 2A to 2C , which shows details of a fiber array unit (FAU) 400 according to some embodiments. It should be noted that the FAU 400 is similar to the above-described FAU 300, except that the waveguide structure 306 is replaced by a plurality of waveguides 410. Specifically, in the FAU 400, the waveguide structure 306 is omitted, and the plurality of waveguides 410 are formed within the substrate 303 in the second region R2 (e.g., at a specific depth below the upper surface 303C). Similar to the above-described waveguide 307, in a plan view (see Figure 2A ), the waveguides 410 are parallel to each other and aligned in a one-to-one manner with the fiber grooves 305. In addition, although not shown, the waveguides 410 are positioned so that the core of each optical fiber 301 (held by the fiber groove 305) is aligned with the corresponding waveguide 410 in a cross-sectional view (i.e., they are at the same vertical height) to allow optical coupling between the optical fibers 301 and the corresponding waveguides 410.

[0139] In some embodiments, waveguide 410 is formed within glass substrate 303 through an ion exchange process. For example, the ion exchange process can replace existing ions (e.g., Na+, K+, etc.) at a local location of glass substrate 303 (i.e., the location where waveguide 410 is to be formed) with other types of ions (e.g., Ag+, etc.), thereby locally changing the refractive index of the material at that local location. In some cases, the refractive index of the material at that local location may change (e.g., increase) by approximately 0.001 to 0.2 due to the ion exchange process. In this way, waveguide 410 can be directly formed (e.g., embedded) within glass substrate 303. Waveguide 410 has the same function as waveguide 307, and therefore will not be repeated here.

[0140] In addition, due to the Figures 2A to 2C In the example of FIG, the waveguide structure 306 is omitted, and the one or more reflectors 309 are formed directly on the upper surface 303C near the second end 303B of the substrate 303. In such an embodiment, the one or more reflective surfaces (of the one or more reflectors 309) can be formed using a technique similar to that used to form the optical fiber groove 305, such as embossing, molding, mechanical cutting, laser cutting, chemical etching, etc. In some embodiments, the one or more reflective surfaces and the optical fiber groove 305 are formed in a single step using the same process (e.g., an embossing process).

[0141] In an alternative embodiment, if Figure 2B-1 As shown in FIG, waveguide 410 can be replaced by a waveguide 411 formed using laser writing technology. For example, the laser writing process can focus a laser spot on a local location of the glass substrate 303 (i.e., the location where waveguide 411 is to be formed), thereby using thermal energy to locally change the refractive index of the material at that local location. In some cases, the refractive index of the material at the local location may change (e.g., increase) by approximately 0.001 to 0.2 due to the laser writing process. In this way, waveguide 411 can be directly formed (e.g., embedded) within the glass substrate 303. The details of waveguide 411 are similar to those of waveguide 410.

[0142] In another alternative embodiment, Figure 2B-2 As shown in , the one or more reflectors 309 may also be replaced by one or more reflectors 409 formed using laser writing technology. By forming one or more reflectors 409 directly in the glass substrate 303 using laser writing technology, the process for forming the reflective surface and the reflective coating can be omitted.

[0143] Now refer to Figures 3A to 3C, which shows details of a fiber array unit (FAU) 500 according to some embodiments. It should be noted that the FAU 500 is similar to the FAU 400 described above, except that the waveguide 410 in the second region R2 is omitted and the plurality of reflectors 309 are positioned near the fiber groove 305. In the plan view (see Figure 3A ), the reflectors 309 are aligned with the fiber grooves 305 in a one-to-one manner. In addition, although not shown, the reflectors 309 are positioned so that the core of each optical fiber 301 (held by the fiber groove 305) is aligned with the corresponding reflector 309 in a cross-sectional view (i.e., they are at the same vertical height) to allow optical coupling between the optical fibers 301 and the corresponding reflectors 309 (i.e., light from the optical fibers 301 can be guided by the reflectors 309). In some alternative embodiments, a single reflector 309 is used instead of a plurality of reflectors 309.

[0144] Figure 4 A flow chart is shown of a method 1000 for forming a FAU (e.g., FAU 300, 400, or 500) according to some embodiments. Method 1000 includes operation 1010, in which a fiber trench (e.g., 305) is formed in a first region (e.g., R1) of a UV-transparent substrate (e.g., 303). Method 1000 also includes operation 1020, in which a waveguide (e.g., 307, 410, 411) and / or a reflector (e.g., 309, 409) is formed in a second region (e.g., R2) of the UV-transparent substrate.

[0145] Figures 5A to 5C Various views of a fiber array unit (FAU) 600 are shown according to some embodiments. The FAU 600 is similar to the FAU 300 described above, except that the fiber grooves 305 are replaced by through-silicon grooves (TSVs) 605 formed in an additional silicon substrate 603. Specifically, in the FAU 600, the fiber grooves 305 are omitted (i.e., there are no fiber grooves in the substrate 303), and the TSVs 605 for holding the optical fibers 301 are formed to extend through the top and bottom surfaces of the silicon substrate 603 (the arrangement of the TSVs 605 can be similar to the arrangement of the fiber grooves 305 described above). The silicon substrate 603 is then attached (e.g., bonded) to the substrate 303 (e.g., a glass substrate) by thermal bonding techniques, such as a low-temperature direct bonding process (e.g., at a temperature below about 250°C). The interface between the glass substrate 303 and the silicon substrate 603 is formed by Figure 5C Indicated by line 606 in FIG.

[0146] In such an embodiment, during the curing process, light (eg, UV light) may pass through the TSV 605 and the glass substrate 303 to cure the underlying optical adhesive 217 (see FIG. Figure 17 In addition, since acceptable semiconductor manufacturing processes (e.g., photolithography and etching processes) can be used to form TSVs 605 in silicon substrate 603, the size (e.g., maximum width W') and spacing (e.g., pitch P') of TSVs 605 can be smaller. This facilitates accommodating more and smaller optical fibers 301.

[0147] In some embodiments, during the formation of the FAU 600, the silicon substrate 603 having the TSV 605 is first placed (eg, mounted) on a pre-formed L-shaped glass substrate 303 (see FIG. Figure 5B ), then the waveguide structure 306 and the reflector 309 are formed on the protruding portion of the L-shaped glass substrate 303 (similar to Figures 1A to 1C embodiment).

[0148] In some alternative embodiments, during the formation of the FAU 600, the silicon substrate 603 having the TSV 605 is placed (e.g., mounted) on a first region R1 of a planar (e.g., flat) glass substrate 303′ (also referred to as a glass support 303′, e.g., the lower portion of the aforementioned glass substrate 303), and the glass substrate 303″ (e.g., the upper portion of the aforementioned glass substrate 303) is attached (e.g., bonded) to a second region R2 of the planar glass substrate 303′ (the interface between the planar glass substrate 303′ and the glass substrate 303″ is formed by Figure 5B ). The waveguide structure 306 and the reflector 309 can be formed on the glass substrate 303" before or after bonding the glass substrate 303" to the glass support 303'. In some cases, the thickness T' of the glass support 303' can range between 200 μm and 700 μm, although lesser or greater thicknesses can also be used.

[0149] The functions and advantages of FAU 600 are similar to those of FAU 300 described above, so they will not be repeated here.

[0150] Figures 6A to 6C Various views of a fiber array unit (FAU) 700 are shown according to some embodiments. The FAU 700 is similar to the FAU 400 described above, except that the fiber grooves 305 are replaced by through silicon vias (TSVs) 605 formed in an additional silicon substrate 603, and the silicon substrate 603 having the TSVs 605 is mounted on the first region R1 of the glass substrate 303. The formation method, configuration, and function of the TSVs 605 have been described in detail in the accompanying drawings. Figures 5A to 5C In various embodiments, the waveguide 410 can be formed in the glass substrate 303 by an ion exchange or laser writing process (as described above).

[0151] Figures 7A to 7C Various views of a fiber array unit (FAU) 800 according to some embodiments are shown. The FAU 800 is similar to the FAU 500 described above, except that the fiber grooves 305 are replaced by through silicon vias (TSVs) 605 formed in an additional silicon substrate 603, and the silicon substrate 603 having the TSVs 605 is mounted on the first region R1 of the glass substrate 303. The formation method, configuration, and function of the TSVs 605 have been described in detail in the accompanying drawings. Figures 5A to 5C In some embodiments, one or more reflectors 309 of the FAU 800 may be formed using the above-described Figures 2A to 2C The reflector 309 in the example is formed on the upper surface 303C near the second end 303B of the substrate 303 by the technology of FIG. Figure 2B-2 , one or more reflectors 409 may be formed directly in the glass substrate 303 using laser writing techniques.

[0152] It should be understood that the structures, configurations, and manufacturing methods described herein are merely exemplary and are not intended to, and should not be construed to, limit the present invention. Numerous alternatives and modifications will be readily apparent to those skilled in the art upon learning the contents of the present invention. For example, the various features of the various embodiments described above may be combined in any manner.

[0153] Figure 8 A flow chart is shown of a method 2000 for forming a FAU (e.g., FAU 600, 700, or 800) according to some embodiments. Method 2000 includes operation 2010, in which a through-silicon via (e.g., 605) is formed in a silicon substrate (e.g., 603). Method 2000 also includes operation 2020, in which the silicon substrate having the through-silicon via is mounted on (e.g., bonded to) a first region (e.g., R1) of a UV-transparent substrate (e.g., 303). Method 2000 also includes operation 2030, in which a waveguide (e.g., 307, 410) and / or a reflector (e.g., 309, 409) is formed in a second region (e.g., R2) of the UV-transparent substrate.

[0154] Next, combine the following Figures 9 to 17 The photonic system (eg, FAU 300) described in some embodiments of the present invention includes the above-described FAU. Figure 17 Although the method embodiments are discussed as being performed in a particular order, other method embodiments may be performed in any logical order.

[0155] first, Figures 9 to 12A cross-sectional view showing an intermediate step in forming a photonic package 100 according to some embodiments. In some cases, the photonic package 100 can be a semiconductor package 150 (e.g., see Figure 14 ) or a part of another structure. The photonic package 100 may provide an input / output (I / O) interface between optical signals and electrical signals in the semiconductor package 150 .

[0156] refer to Figure 9 , the first side of the wafer 10 (eg, Figure 9 The wafer 10 includes a plurality of photonic dies 120 separated by dicing regions. The dicing regions of the wafer 10 are located at Figure 9 The wafer 20 includes a plurality of electronic dies 110 separated by a dicing region. The dicing region of the wafer 20 is located at Figure 9 Indicated by line 21. Figure 12 Details of the photonic die 120 and the electronic die 110 are shown and discussed.

[0157] Wafer 10 is bonded to wafer 20 by a suitable bonding process, such as dielectric-to-dielectric bonding and / or metal-to-metal bonding (e.g., direct bonding, fusion bonding, oxide-to-oxide bonding, hybrid bonding, etc.). In this case, covalent bonds may be formed between oxide layers, such as between the topmost dielectric layer at the first side of wafer 10 and the topmost dielectric layer at the front side of wafer 20. During the bonding process, metal bonding may also occur between the die connector 118 of the electronic die 110 and the die connector 128 of the photonic die 120. Figure 9 In the example of FIG. 1 , after the wafer bonding process, the dicing regions of the wafer 10 are aligned with the corresponding dicing regions of the wafer 20 .

[0158] Next, in Figure 10 , the conductive bumps 145 are formed on the second side of the wafer 10 (eg, Figure 10 ) to electrically couple to the conductive features (e.g., conductive pads and / or conductive vias) of the photonic die 120. In a subsequent sawing process (see Figure 11) to form an individual photonic package 100, the conductive bumps 145 serve as external connectors of the photonic package 100. The conductive bumps 145 may be any suitable type of external connector, such as ball grid arrays (BGAs) connectors, solder balls, metal pillars, controlled collapse chip connection (C4) bumps, microbumps, bumps formed using electroless nickel-electroless palladium-immersion gold (ENEPIG) technology, etc., and may include conductive materials such as solder, copper, aluminum, gold, nickel, silver, palladium, tin, etc., or combinations thereof.

[0159] Next, in Figure 11 In the embodiment of the present invention, a dicing process is performed along dicing regions of wafers 10 and 20 to produce a plurality of individual (e.g., separate) photonic packages 100, wherein each photonic package 100 includes a photonic die 120 attached (e.g., bonded) to an electronic die 110. As an example, the dicing process can be performed using a blade or a laser dicing tool.

[0160] Now refer to Figure 12 , which shows details of the photonic package 100. It should be noted that Figure 12 The photonic package 100 corresponds to Figure 11 The photonic package 100 in FIG. 1 is shown, but upside down. Figure 12 In the example of , the photonic package 100 includes an electronic die 110 attached (eg, bonded) to a photonic package 120 .

[0161] Electronic die 110 can be, for example, a semiconductor device, die, or chip that communicates with photonic die 120 using electrical signals. In the described embodiment, electronic die 110 does not receive, transmit, or process optical signals. In this discussion, the term "electronic die" is used to distinguish it from a "photonic die" (e.g., 120), which refers to a die that can receive, transmit, or process optical signals, such as converting an optical signal into an electrical signal or vice versa. In addition to optical signals, photonic die 120 can also transmit, receive, or process electrical signals. Figure 12 One electronic die 110 is shown in FIG, but in other embodiments, the photonic package 100 may include two or more electronic dies 110. In some cases, multiple electronic dies 110 may be integrated into a single photonic package 100 to reduce processing costs.

[0162] In some embodiments, electronic die 110 includes a substrate 111 (e.g., a semiconductor substrate such as a silicon substrate). Electronic components (not shown for simplicity) such as transistors, diodes, capacitors, and resistors can be formed in and / or on substrate 111 and can be interconnected via an interconnect structure 112 to form an integrated circuit. Interconnect structure 112 can be formed by metallization patterns (e.g., conductive lines 115 and conductive vias 117) in one or more dielectric layers 113 above substrate 111. Electronic die 110 also includes conductive pads (not shown for simplicity), such as aluminum pads, for external connections. The conductive pads are located on what can be considered the active side (or front side) of electronic die 110. One or more passivation layers (not shown for simplicity) are formed on the front side of electronic die 110 and on portions of the conductive pads. Die connectors 118, such as conductive pillars (e.g., comprising a metal such as copper), are formed to extend through the passivation layers and mechanically and electrically couple to corresponding conductive pads. The die connector 118 is electrically coupled to the integrated circuit of the electronic die 110 .

[0163] It should be noted that in Figure 12 In the example of FIG. 1 , portions of the dielectric layer 113 of the electronic die 110 that do not have functional circuitry are replaced by a dielectric material 119. In some embodiments, the dielectric material 119 may be a gap-filling material that may include silicon oxide, silicon nitride, a polymer, or the like, or a combination thereof. In some embodiments, the dielectric material 119 may be a gap-filling material that is suitable for optical components (e.g., grating coupler 138) in the photonic die 120 and a plurality of optical fibers (e.g., optical fibers) attached to the photonic package 100. Figure 17 A material (e.g., silica) that is substantially transparent to light of a wavelength at which optical signals or optical power are transmitted between optical fibers 301 shown in FIG.

[0164] The electronic die 110 may include an integrated circuit for interfacing with the photonic components 137 (e.g., photodetectors and / or modulators) of the photonic die 120. The electronic die 110 may include circuitry for controlling the operation of the photonic components 137. For example, the electronic die 110 may include a controller, a driver, transimpedance amplifiers, or the like, or a combination thereof. In some embodiments, the electronic die 110 may also include a central processing unit (CPU). In some embodiments, the electronic die 110 includes circuitry for processing electrical signals received from the photonic components 137, including the photodetectors. In some embodiments, the electronic die 110 may control the high-frequency signal transmission of the photonic components 137 based on an electrical signal (digital or analog) received from another device or die. In some embodiments, the electronic die 110 may be an electronic integrated circuit (EIC) that provides serializer / deserializer (SerDes) functionality. In this manner, the electronics die 110 may function as part of an I / O interface between optical and electrical signals within the photonic package 100 .

[0165] Still refer to Figure 12 The photonic die 120 includes one or more dielectric layers 131, conductive features (e.g., conductive lines 133 and conductive vias 135) formed in the dielectric layers 131, and various photonic devices formed in the dielectric layers 131, such as waveguides 136, photonic components 137, and grating couplers 138 (for simplicity, Figure 12 Only one photonic component 137 and one grating coupler 138 are shown in FIG. ), a nitride waveguide 139 , etc. In addition, the photonic die 120 includes an interconnect structure 122 located above the dielectric layer 131 and a conductive bump 145 located below the dielectric layer 131 .

[0166] In some embodiments, waveguide 136 is a silicon waveguide formed by patterning a silicon layer. A single waveguide 136 or multiple waveguides 136 can be patterned from a silicon layer. If multiple waveguides 136 are formed, the multiple waveguides 136 can be separate, discrete waveguides 136 or connected as a single, continuous structure. In some embodiments, one or more waveguides 136 form a continuous loop. Due to the difference in refractive index between the materials of waveguide 136 and dielectric layer 131, waveguide 136 has high internal reflection, which substantially confines light within waveguide 136, depending on the wavelength of the light and the refractive index of the individual materials. In some embodiments, the refractive index of the material of waveguide 136 is higher than the refractive index of the material of dielectric layer 131. For example, waveguide 136 can comprise silicon, while dielectric layer 131 can comprise silicon oxide and / or silicon nitride. Therefore, waveguide 136 may also be referred to herein as a "silicon waveguide."

[0167] The photonic component 137 may be integrated with the waveguide 136 and may be formed together with the waveguide 136. The photonic component 137 may be optically coupled to the waveguide 136 to interact with the optical signal within the waveguide 136. The photonic component 137 may include, for example, a photonic device, such as a photodetector and / or a modulator. For example, the photodetector may be optically coupled to the waveguide 136 to detect the optical signal within the waveguide 136 and generate an electrical signal corresponding to the optical signal, and the modulator may be optically coupled to the waveguide 136 to receive the electrical signal and generate a corresponding optical signal within the waveguide 136 by modulating the optical power within the waveguide 136. In this way, the photonic component 137 may facilitate the input / output (I / O) of the optical signal to the waveguide 136. In other embodiments, the photonic component 137 may include other active or passive components, such as a laser diode, an optical signal splitter (splitter), or other types of photonic structures or devices. The optical power may be supplied to the waveguide 136 by, for example, an optical fiber 301 attached to the photonic package 100 (see Figure 17 ) are provided to the waveguide 136. Contacts 132 (eg, copper vias) are formed to electrically couple the photonic component 137 to the interconnect structure 122 of the photonic die 120.

[0168] The grating coupler 138 may be integrated with the waveguide 136 and may be formed together with the waveguide 136. The grating coupler 138 is a device that allows optical signals and / or optical power to be transmitted between the waveguide 136 and another photonic component (e.g., an external optical fiber 301 (see FIG. 1 )). Figure 17 ) or a waveguide of another photonic system).

[0169] Figure 12Also shown are multiple nitride (e.g., silicon nitride) waveguides 139 formed in different layers of the dielectric layer 131. The nitride waveguides 139 can provide additional optical signal routing and can be optically coupled to the waveguide 136. The nitride waveguides 139 can be formed by patterning the silicon nitride layer. One nitride waveguide 139 or multiple nitride waveguides 139 can be formed by patterning the silicon nitride layer. If multiple nitride waveguides 139 are formed, the multiple nitride waveguides 139 can be individual, separate nitride waveguides 139 or connected as a single continuous structure. In some embodiments, one or more nitride waveguides 139 form a continuous loop. Although not shown, the nitride waveguides 139 can include photonic structures such as grating couplers, edge couplers, or other types of couplers (e.g., mode converters) that allow optical signals to be transmitted between two nitride waveguides 139 and / or between one nitride waveguide 139 and one waveguide 136. In other embodiments, the nitride waveguide 139 may be omitted.

[0170] Figure 12 Also shown is an interconnect structure 122 of the photonic die 120. The interconnect structure 122 includes one or more dielectric layers 123 and conductive features (e.g., conductive lines 125 and conductive vias 127) formed in the dielectric layers 123. A die connector 128 (e.g., a copper pillar, a copper pad, etc.) of the photonic die 120 is formed on the upper surface of the photonic die 120 and is electrically coupled to the conductive features of the interconnect structure 122. The circuitry of the electronic die 110 and the photonic components 137 of the photonic die 120 are electrically coupled via the interconnect structures 112, 122 and the die connectors 118, 128. Conductive features in the dielectric layers 123 and 131 electrically couple the die connector 128 to the conductive bumps 145. In some embodiments, the dielectric layers 123 and 131 are formed of a dielectric material (e.g., silicon oxide) that is substantially transparent to light of a wavelength suitable for transmitting optical signals.

[0171] It should be noted that Figure 12 The types of components, numbers of components, and arrangements / configurations of components shown are merely non-limiting examples, and other types / numbers of components and other arrangements / configurations of components are possible and are fully intended to be within the scope of the present invention.

[0172] Figure 13 and 14 A cross-sectional view shows an intermediate step in forming a semiconductor package 150 according to some embodiments. In some embodiments, the semiconductor package 150 includes at least one photonic package 100 and at least one electronic die 152 interconnected by a redistribution structure 160 (also referred to as an interconnect structure 160).

[0173] refer to Figure 13, attaching the photonic package 100 and the electronic die 152 to the carrier 151. The carrier 151 may be, for example, a glass carrier, a ceramic carrier, etc. The photonic package 100 and the electronic die 152 may be attached to the carrier 151 using, for example, an adhesive or a release layer (not shown). The electronic die 152 may be, for example, a CPU die, an application-specific integrated circuit (ASIC) die, a high-bandwidth memory (HBM) die, etc. The electronic die 152 may include a substrate 153, electronic components formed in and / or on the substrate 153 (not shown for simplicity), and an interconnect structure (not shown for simplicity) that connects the electronic components to form the functional circuit of the die. The die connector 155 of the electronic die 152 provides electrical connection to the electronic die 152. The details of the electronic die 152 are similar to those of the above-mentioned electronic die 110, so they will not be repeated here. Figure 13 One photonic package 100 and one electronic die 152 are shown in FIG. 1 , but in other embodiments, the semiconductor package 150 may include other numbers of photonic packages 100 and / or electronic dies 152 .

[0174] Next, a molding material 157 is formed on the carrier 151 and surrounds the photonic package 100 and the electronic die 152. For example, the molding material 157 can seal the photonic package 100 and the electronic die 152. The molding material 157 is also formed in the gap between the photonic package 100 and the electronic die 152. The molding material 157 can be a molding compound, an epoxy resin, etc., and can be applied by compression molding, transfer molding, etc. The molding material 157 can be applied in a liquid or semi-liquid form and then cured. In some embodiments, after forming the molding material 157, a planarization process (e.g., a chemical mechanical polishing (CMP) process, a grinding process, etc.) is performed on the molding material 157. After the planarization process is performed, the top surfaces of the molding material 157, the photonic package 100, and the electronic die 152 can be substantially horizontal or coplanar.

[0175] Next, a redistribution structure 160 is formed over the molding material 157 and electrically coupled to the photonic package 100 and the electronic die 152. In some embodiments, the redistribution structure 160 includes one or more dielectric layers 161 and one or more conductive features (e.g., conductive lines 163 and conductive vias 165) formed in the dielectric layers 161. In some embodiments, the one or more dielectric layers 161 are formed from a polymeric layer, such as polybenzoxazole (PBO), polyimide, benzocyclobutene (BCB), or the like. In other embodiments, the dielectric layer 161 is formed from a nitride, such as silicon nitride; an oxide, such as silicon oxide, phosphosilicate glass (PSG), borosilicate glass (BSG), boron-doped phosphosilicate glass (BPSG), or the like. The one or more dielectric layers 161 can be formed by any acceptable deposition process, such as spin coating, chemical vapor deposition (CVD), lamination, or a combination thereof. The conductive lines 163 and the conductive vias 165 can be formed of suitable conductive materials, such as copper, titanium, tungsten, aluminum, etc. Further details of the redistribution structure 160 will not be described here.

[0176] Next, conductive bumps 167 are formed over the redistribution structure 160 and electrically coupled to the redistribution structure 160. Similar to conductive bumps 145, conductive bumps 167 can be any suitable type of external connector, such as a BGA connector, a solder ball, a metal pillar, a C4 bump, a micro bump, an ENEPIG-formed bump, etc.

[0177] As those skilled in the art will readily appreciate, multiple (e.g., identical) semiconductor packages 150 may be formed simultaneously (e.g., in the same processing step) on the carrier 151. These semiconductor packages 150 will be separated in a subsequent sawing process to form individual, separate semiconductor packages 150.

[0178] Next, in Figure 14 In the process, the carrier 151 is removed by a carrier be-bonding process. Figure 13 The resulting structure is flipped over and the conductive bumps 167 are attached to a dicing tape (not shown). Next, a dicing process is performed along line 169 to produce a plurality of conductive bumps 167 as shown in FIG. Figure 14 The individual (eg, separated) semiconductor packages 150 are shown in FIG. As an example, the cutting process can be performed using a blade or a laser cutting tool.

[0179] Figures 15 to 17A cross-sectional view shows an intermediate step in forming a photonic system 200 according to some embodiments. Photonic system 200 includes at least one semiconductor package 150 optically coupled to a fiber array unit (FAU) 300 comprising a plurality of optical fibers 301. In this manner, optical signals and / or optical power can be transmitted to and from semiconductor package 150. For example, an optical signal can be transmitted from an optical fiber to semiconductor package 150. The optical signal can be processed or analyzed by semiconductor package 150, which can then generate other optical signals and transmit them to optical fibers 301. The above is merely an example, and other applications are possible.

[0180] exist Figure 15 In the embodiment of the present invention, the semiconductor package 150 is attached (e.g., bonded) to the substrate 201. The substrate 201 can be an interposer, a semiconductor substrate, a redistribution structure, a core substrate, etc. The substrate 201 can include conductive pads 203 formed on its upper and lower surfaces and conductive features (e.g., conductive lines and / or vias, not shown for simplicity) connecting the conductive pads 203 on both sides of the substrate 201. In some embodiments, the substrate 201 includes active devices and / or passive devices. In other embodiments, the substrate 201 does not have active devices and / or passive devices. In some embodiments, the semiconductor package 150 is bonded to the substrate 201 by placing the conductive bumps 167 of the semiconductor package 150 over the upper conductive pads 203 of the substrate 201 and then performing a reflow process. In this way, the semiconductor package 150 can be physically and electrically coupled to the substrate 201 (e.g., via the conductive structure 205, such as solder material disposed between the conductive bumps 167 and the upper conductive pads 203).

[0181] Next, an underfill material 207 is formed on the substrate 201 and around the semiconductor package 150. The underfill material 207 can flow under the semiconductor package 150 and into the gaps between the conductive structures 205 to enhance the connection between the semiconductor package 150 and the substrate 201. The underfill material 207 can include an epoxy, a resin, a filler material, a stress release agent (SRA), an adhesion promoter, another suitable material, or a combination thereof. In some embodiments, the underfill material 207 can be applied in liquid form and then cured.

[0182] Next, on the 16th Figure 16, a cover 211 is attached to the substrate 201. The cover 211 can be attached to the substrate 201, for example, by an adhesive material 213. The provision of the cover 211 helps to reduce warping of the substrate 201. The central portion of the cover 211 can contact the electronic die 152 and the photonic package 100 directly or through a thermal interface material (TIM) 215 to facilitate heat dissipation. In this case, the material of the cover 211 can include metals such as copper, stainless steel, stainless steel / nickel, etc., but is not limited thereto. In some embodiments, the cover 211 has at least one opening 212 at its top to allow, for example, the FAU 300 (see Figure 17 ) is attached to the semiconductor package 150. In other embodiments, the lid 211 may be replaced by a stiffening ring, and the FAU 300 may be attached to the semiconductor package 150 through the hollow center portion of the stiffening ring.

[0183] External connectors 209 (eg, solder balls) are then formed on the lower surface of substrate 201 and connected to lower conductive pads 203 so that photonic system 200 can be coupled to another electronic device or system.

[0184] Next, in Figure 17 In FIG. 1 , the FAU 300 is attached to the top of the semiconductor package 150 (e.g., to the substrate 111 of the electronic die 110) through the opening 212 of the cover 211, for example, by optical glue 217. After the optical glue 217 is dispensed between the FAU 300 and the semiconductor package 150, in some cases, the optical glue 217 can be cured, for example, by ultraviolet (UV) curing. Each optical fiber 301 of the FAU 300 is connected to the photonic die 120 within the semiconductor package 150 (see FIG. 1 ). Figure 12 ) are optically coupled to corresponding grating couplers 138 within the semiconductor package 150, so that optical signals and / or optical power can be transmitted between the semiconductor package 150 and the optical fibers 301. In some cases, the end of each optical fiber 301 opposite the semiconductor package 150 can be coupled to an optical interconnect (e.g., an MT ferrule, etc., not shown), and the optical interconnect is coupled to a light source (not shown).

[0185] In some embodiments, the FAU 300 includes an integrated optical fiber groove (eg, a recess) and a light guide element (eg, Figures 1A to 1C The substrate 303 (also referred to as the bottom plate 303) is provided with a waveguide 307 and a reflector 309 as shown in FIG, so that the optical fiber 301 can be fixed in the optical fiber groove and the optical signal from the optical fiber 301 can be guided (e.g., redirected) by the optical waveguide element (e.g., Figure 17 ) to the corresponding grating coupler 138 in the semiconductor package 150 (or vice versa). When assembling the FAU 300, as shown in FIG. Figure 17 As shown in FIG, substrate 303 is attached (e.g., fixed) to semiconductor package 150 by optical glue 217. In addition, a cover 302 is present over substrate 303 to cover and protect optical fiber 301 and light guide element, and optical glue 304 can be dispensed in gaps between substrate 303, cover 302, optical fiber 301, and light guide element to connect these components.

[0186] It should be noted that in Figure 17 In the example of FIG, FAU 300 is placed on top of semiconductor package 150, rather than near the sidewall of semiconductor package 150. This avoids the problem that the space (e.g., height) between the optical coupler (e.g., edge coupler) in photonic die 120 and substrate 201 may be insufficient to accommodate FAU 300 for optical coupling. In other embodiments, FAU 300 may be replaced by FAU 400, 500, 600, 700, or 800 of the above embodiments.

[0187] The FAU embodiments discussed herein may have advantages. The fiber grooves and light-guiding elements (e.g., waveguides and / or reflectors) are integrated into a single supporting substrate, thereby eliminating the need for additional assembly alignment between the fiber grooves and the light-guiding elements, thereby reducing the number of steps in manufacturing the FAU. In addition, since the bonding interface (e.g., optical glue) between the fiber grooves and the light-guiding elements is omitted, the optical performance of the FAU may be improved. In addition, the supporting substrate may be made of a UV-transparent material to allow UV light to pass through to cure the optical glue during the curing process, thereby enabling the FAU to be well attached to the semiconductor package in the photonic system.

[0188] According to some embodiments, a fiber array unit (FAU) is provided. The FAU includes a substrate, a plurality of fiber grooves, and a plurality of light guide elements. The substrate has a first region and a second region that are continuous and connected. The fiber grooves are formed in the first region. The light guide elements are formed in the second region, wherein the fiber grooves are aligned with the light guide elements, respectively.

[0189] In some embodiments, the substrate comprises a material that allows ultraviolet light to pass through, including glass, sol-gel glass, or a polymer transparent to ultraviolet light. In some embodiments, the optical fiber groove is formed on the upper surface of the substrate and is recessed from the upper surface of the substrate. In some embodiments, the optical fiber groove is a plurality of through-silicon vias (TSVs) formed in a silicon substrate, and the silicon substrate is placed on the substrate comprising the glass material. In some embodiments, the optical waveguide element comprises a plurality of waveguides and at least one reflector, wherein the waveguides extend from an end of the second region of the substrate adjacent to the optical fiber groove to an end of the second region opposite the optical fiber groove, and the at least one reflector is disposed near the end of each of the waveguides opposite the optical fiber groove. In some embodiments, the waveguides are formed in one or more dielectric layers above the upper surface of the substrate, and the at least one reflector is formed at the end of the one or more dielectric layers opposite the optical fiber groove. In some embodiments, the waveguides are formed within the substrate below the upper surface of the substrate. In some embodiments, the at least one reflector is formed on the upper surface of the substrate near the end of each waveguide opposite the optical fiber groove. In some embodiments, the at least one reflector is formed within the substrate near the end of each waveguide opposite the optical fiber groove. In some embodiments, the light guide element includes a plurality of reflectors disposed near an end of each of the waveguides opposite the optical fiber groove.

[0190] According to some embodiments, a method for forming an optical fiber array unit is provided. The method includes providing a substrate comprising a material that allows ultraviolet (UV) light to pass therethrough. The method includes forming a plurality of optical fiber grooves in a first region of the substrate. The method also includes forming a plurality of light guide elements in a second region of the substrate, wherein the first region and the second region are continuous and connected.

[0191] In some embodiments, the material of the substrate includes glass, sol-gel glass, or a polymer transparent to ultraviolet light. In some embodiments, forming the optical fiber groove includes forming the optical fiber groove on the upper surface of the substrate. In some embodiments, forming the optical fiber groove includes forming a plurality of through-silicon vias (TSVs) in a silicon substrate and bonding the silicon substrate having the TSVs to a substrate. In some embodiments, forming the optical waveguide element includes forming a plurality of waveguides in one or more dielectric layers above the upper surface of the substrate, and forming at least one reflector at an end of the one or more dielectric layers opposite the optical fiber groove. In some embodiments, forming the optical waveguide element includes forming a plurality of waveguides within the substrate below the upper surface of the substrate using an ion exchange process or a laser writing process. In some embodiments, forming the optical waveguide element also includes forming at least one reflector on the upper surface of the substrate near an end of each of the waveguides opposite the optical fiber groove, wherein the at least one reflector includes a reflective coating. In some embodiments, forming the optical waveguide element also includes forming at least one reflector within the substrate near an end of each of the waveguides opposite the optical fiber groove using a laser writing technique.

[0192] According to some embodiments, a fiber array unit is provided. The fiber array unit includes a substrate, a plurality of fiber grooves, a plurality of waveguides, and at least one reflector. The substrate has a first region and a second region that are continuous and connected. The fiber grooves are formed in the first region. The waveguides are formed in the second region and aligned with the fiber grooves, wherein no adhesive is formed between one of the waveguides and the corresponding one of the fiber grooves. The at least one reflector is formed at an end of the second region opposite the fiber groove.

[0193] In some embodiments, each of the fiber grooves extends along a first direction, wherein the first region and the second region of the substrate are arranged along the first direction, and each of the waveguides extends along the first direction.

[0194] The above summarizes the features of many embodiments so that those skilled in the art to which the present invention belongs can better understand the various embodiments of the present invention. Those skilled in the art to which the present invention belongs should understand that other processes and structures can be easily designed or modified based on the embodiments of the present invention to achieve the same purposes and / or obtain the same advantages as the embodiments described herein. Those skilled in the art to which the present invention belongs should also understand that these equivalent structures do not depart from the concept and scope of the present invention. Various changes, substitutions and modifications can be made to the embodiments of the present invention without departing from the concept and scope of the appended claims.

Claims

1. An optical fiber array unit, characterized in that: include: A substrate having a first region and a second region that are continuous and connected; a plurality of optical fiber grooves formed in the first region; as well as A plurality of light guide elements are formed in the second area, wherein the optical fiber grooves are respectively aligned with the light guide elements.

2. The optical fiber array unit according to claim 1, wherein: The optical fiber grooves are formed on an upper surface of the substrate and recessed from the upper surface.

3. The optical fiber array unit according to claim 1, wherein: The optical fiber grooves are a plurality of silicon through-holes formed in a silicon substrate, and the silicon substrate is placed on the substrate comprising glass material.

4. The optical fiber array unit according to claim 1, wherein: The light guide components include: a plurality of waveguides extending from an end of the second region adjacent to the optical fiber grooves to an opposite end of the second region away from the optical fiber grooves; and At least one reflector is disposed near an end of each of the waveguides opposite to the optical fiber grooves.

5. The optical fiber array unit according to claim 4, wherein: The waveguides are formed in one or more dielectric layers above an upper surface of the substrate, and the at least one reflector is formed at an end of the one or more dielectric layers opposite to the optical fiber grooves.

6. The optical fiber array unit according to claim 4, wherein: The waveguides are formed in the substrate below an upper surface of the substrate.

7. The optical fiber array unit according to claim 6, wherein: The at least one reflector is formed on the upper surface of the substrate near the end of each waveguide opposite to the optical fiber grooves.

8. The optical fiber array unit according to claim 6, wherein: The at least one reflector is formed in the substrate near the end of each waveguide opposite to the optical fiber grooves.

9. An optical fiber array unit, characterized in that: include: A glass substrate having a first region and a second region that are continuous and connected; a plurality of optical fiber grooves formed in the first region; a plurality of waveguides formed in the second region and aligned with the optical fiber grooves, wherein no adhesive is formed between one of the waveguides and a corresponding one of the optical fiber grooves; and At least one reflector is formed at an end of the second region opposite to the optical fiber grooves.

10. The optical fiber array unit according to claim 9, wherein: Each of the optical fiber grooves extends along a first direction, and the first region and the second region are arranged along the first direction; and Each of the waveguides extends along the first direction.

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