Semiconductor device

Abstract

A semiconductor device includes a support structure, a substrate on the support structure, the substrate including an outer substrate layer and an inner substrate layer attached to the outer substrate layer, and the inner substrate layer including a recess having a recess bottom and a recess sidewall abutting the recess bottom. The recess may be located at an interface between the outer substrate layer and the inner substrate layer, and the interface may be substantially perpendicular to the support structure. The optical fiber array unit further comprises a mirror surface, and the mirror surface comprises reflecting layers located at the bottom of the groove and on the side wall of the groove.

Description

Technical Field

[0001] This utility model relates to semiconductor technology, and more particularly to semiconductor devices. Background Technology

[0002] A fiber optic array unit (FAU) is an optical element used in optical systems and devices. An FAU can manipulate and / or direct optical signals carried by one or more optical fibers.

[0003] A fiber optic array unit (FAU) may include one or more fiber optic ports, which can be used as input and / or output interfaces for optical signals. The fiber optic ports can be configured as a linear or two-dimensional array. The FAU may also include a fiber optic holder (fiber optic receptacle) for each fiber optic port. The fiber optic holder (fiber optic receptacle) securely holds the fiber in place to maintain precise alignment and minimize signal loss. Utility Model Content

[0004] The purpose of this invention is to provide a semiconductor device to solve at least one of the above-mentioned problems.

[0005] This invention provides a semiconductor device, comprising: a support structure; a substrate located on the support structure, the substrate comprising: an outer substrate layer; and an inner substrate layer attached to the outer substrate layer and including a recess, the recess including a recess bottom and a recess sidewall adjoining the recess bottom, wherein the recess is located at the interface between the outer substrate layer and the inner substrate layer, and the interface is substantially perpendicular to the support structure; and a mirror comprising a reflective layer located at the recess bottom and on the recess sidewall.

[0006] According to one embodiment of the present invention, the groove sidewall includes a tapered groove sidewall.

[0007] According to one embodiment of the present invention, the conical groove sidewall includes a cone angle of 40° to 50°.

[0008] According to one embodiment of the present invention, the mirror surface includes a mirror bottom portion located at the bottom of the groove and a mirror sidewall portion located on the sidewall of the groove.

[0009] According to one embodiment of the present invention, the inner substrate layer includes a first side surface and a second side surface, the first side surface includes the groove, and the second side surface is relative to and parallel to the first side surface of the inner substrate layer.

[0010] According to one embodiment of the present invention, the support structure includes an upper surface, the upper surface including a groove, the groove being configured to support a first optical fiber such that one end face of the first optical fiber faces the second side surface of the inner substrate layer.

[0011] According to one embodiment of the present invention, the first side surface of the inner substrate layer further includes an alignment groove, the alignment groove includes an alignment groove bottom and an alignment groove sidewall adjacent to the alignment groove bottom, and the alignment groove is located at the interface between the outer substrate layer and the inner substrate layer.

[0012] According to one embodiment of the present invention, it further includes: an alignment mirror, comprising a reflective layer located at the bottom of the alignment groove and on the sidewall of the alignment groove, wherein the alignment mirror includes a bottom portion of the alignment mirror on the bottom of the alignment groove and a sidewall portion of the alignment mirror on the sidewall of the alignment groove.

[0013] According to one embodiment of the present invention, the support structure includes an upper surface, the upper surface including an alignment groove, the alignment groove being configured to support a second optical fiber such that one end face of the second optical fiber faces the second side surface of the inner substrate layer, and a core of the second optical fiber is aligned with the bottom of the alignment mirror.

[0014] This invention provides a semiconductor device, comprising: a support structure including a plurality of trenches configured to support a plurality of first optical fibers; a substrate located on the support structure, the substrate including: an outer substrate layer; and an inner substrate layer attached to the outer substrate layer and including a plurality of grooves, each groove including a groove bottom and a groove sidewall adjacent to the groove bottom, wherein the grooves are located at the interface between the outer substrate layer and the inner substrate layer, and the interface is substantially perpendicular to the support structure; a plurality of functional mirrors including reflective layers located at the groove bottoms and groove sidewalls of the grooves, wherein the functional mirrors are configured to reflect light beams from the first optical fibers in a direction substantially parallel to the interface between the outer substrate layer and the inner substrate layer; and a photodiode array including a plurality of photodiodes configured to receive light beams reflected from the functional mirrors. Attached Figure Description

[0015] The embodiments of the present invention can be best understood from the following detailed description in conjunction with the accompanying drawings. It should be noted that, in accordance with industry standard practice, the various components are not drawn to scale. In fact, the dimensions of various elements can be arbitrarily enlarged or reduced to clearly illustrate the components of the embodiments of the present invention.

[0016] Figure 1A It is a vertical cross-sectional view of a mirrored FAU according to one or more embodiments.

[0017] Figure 1B It is a vertical cross-sectional view of a FAU including an aligned mirror surface according to one or more embodiments.

[0018] Figure 1C It is a perspective view of the FAU according to one or more embodiments.

[0019] Figure 2A This is a detailed vertical cross-sectional view of a mirrored FAU according to one or more embodiments.

[0020] Figure 2B This is a detailed vertical cross-sectional view of a FAU including an aligned mirror surface according to one or more embodiments.

[0021] Figure 3A It is a vertical cross-sectional view of a groove formed in an inner substrate layer according to one or more embodiments.

[0022] Figure 3B It is a vertical cross-sectional view of an inner substrate layer including a mirror, according to one or more embodiments.

[0023] Figure 3C It is a vertical cross-sectional view of an inner base layer including anti-reflective grooves according to one or more embodiments.

[0024] Figure 3D It is a vertical cross-sectional view of an inner base layer including a trench filling layer in an anti-reflective trench according to one or more embodiments.

[0025] Figure 3E It is a vertical cross-sectional view of the inner substrate layer attached to the outer substrate layer according to one or more embodiments.

[0026] Figure 3F It is a vertical cross-sectional view of the substrate after a cutting process has been performed, according to one or more embodiments.

[0027] Figure 3G It is a vertical cross-sectional view of the base on the support structure according to one or more embodiments.

[0028] Figure 4 This is a flowchart illustrating a method for forming a FAU according to one or more embodiments.

[0029] Figure 5A This is a plan view (top view) of a first alternative design of the FAU according to one or more embodiments.

[0030] Figure 5B It is a vertical cross-sectional view of a first alternative design of FAU according to one or more embodiments.

[0031] Figure 6 This is a vertical cross-sectional view of a second alternative design of the FAU according to one or more embodiments.

[0032] Figure 7 This is a vertical cross-sectional view of a third alternative design of the FAU according to one or more embodiments.

[0033] The attached figures are labeled as follows:

[0034] 10: First optical fiber

[0035] 10s: End face

[0036] 12: Core

[0037] 14: Covering layer

[0038] 16: Coating

[0039] 20: Second optical fiber

[0040] 20s: End face

[0041] 21: Beam

[0042] 22: Reflected beam

[0043] 31: Beam

[0044] 32: Reflected beam

[0045] 100: Fiber Array Unit (FAU)

[0046] 110: Supporting structure

[0047] 110us: Upper surface of the support structure

[0048] 120: Base

[0049] 120i: Interface

[0050] 120ls: Substrate underside surface

[0051] 122: Outer basal layer

[0052] 124: Inner basal layer

[0053] 124s1: First side surface

[0054] 124s2: Second side surface

[0055] 125: Anti-reflective layer

[0056] 126: Groove

[0057] 126s: Groove sidewall

[0058] 126b: Bottom of the groove

[0059] 127: Mirror

[0060] 127s: Mirror sidewall section

[0061] 127b: Bottom part of the mirror

[0062] 128: Groove filling layer

[0063] 130: Upper support layer

[0064] 131: First optical adhesive layer

[0065] 132: Second optical adhesive layer

[0066] 145: Anti-reflective coating

[0067] 146: Anti-reflective groove

[0068] 148: Trench filling layer

[0069] 226: Align the groove

[0070] 226s: Groove sidewall

[0071] 226b: Bottom of the groove

[0072] 227: Align with the mirror

[0073] 228: Groove filling layer

[0074] 410: Steps

[0075] 420: Steps

[0076] 430: Steps

[0077] 440: Steps

[0078] 511: Trench

[0079] 531: Third optical adhesive layer

[0080] 535: Protrusion

[0081] 540: Photodiode Array

[0082] 541: Photodiode

[0083] A-A': section line

[0084] B-B': Section line

[0085] C-C': Section line

[0086] X:X direction

[0087] Y:Y direction

[0088] Z:Z direction

[0089] Do: Offset Distance

[0090] D1: Width

[0091] D2: Distance

[0092] D3: Thickness

[0093] D3': Thickness

[0094] D4: Thickness

[0095] D5: Thickness

[0096] D6: Thickness

[0097] D7: Width

[0098] D8: Depth

[0099] D9: Distance

[0100] D10: Distance

[0101] D12: Diameter

[0102] Dt: Depth

[0103] T14: Thickness

[0104] T16: Thickness

[0105] R10: Radius

[0106] R20: Radius

[0107] θ: cone angle Detailed Implementation

[0108] Numerous embodiments or examples are disclosed below for implementing the various elements provided. Specific examples of each element and its configuration are described below to simplify the illustration of embodiments of the present invention. Of course, the above are merely examples and are not intended to limit the embodiments of the present invention. For example, the dimensions of the elements are not limited to the disclosed range or values, but may depend on the process conditions of the apparatus and / or desired characteristics. Furthermore, if the description refers to a first element forming above a second element, it may include embodiments where the first and second elements are in direct contact, or embodiments where an additional element is formed between the first and second elements such that they are not in direct contact. For the sake of brevity and clarity, various components may be drawn at any scale.

[0109] Furthermore, spatially relative terms, such as "below," "under," "lower," "above," and "higher," may be used to facilitate the description of the relationship between one or more components or components in the accompanying drawings. Spatially relative terms are used to include different orientations of the device in use or operation, as well as the orientations described in the accompanying drawings. When the device is turned to different orientations (rotated 90 degrees or other orientations), the spatially relative adjectives used will also be interpreted according to the orientation after the turn.

[0110] A fiber array unit (FAU) may also include one or more front-side mirrors for guiding (reguiding) and / or manipulating optical signals from the fiber. The front-side mirrors may include high-quality reflective surfaces that can be positioned at a specific angle within the unit. The front-side mirrors can be used to perform optical processes such as beam steering, signal routing, or splitting.

[0111] The FAU may also include one or more actuators to control the position of the front mirror. The actuators enable precise adjustment of the mirror's angle, thereby achieving dynamic control of the optical signal path.

[0112] The front-facing mirror (FAU) can be housed in a enclosure that provides mechanical protection and ensures proper alignment and secure fixation of its components. The FAU may include a microcontroller or microprocessor to control its operation. Specifically, the microcontroller or microprocessor can control actuators to remotely and / or automatically control the position of the front-facing mirror. This is particularly useful in dynamic optics systems.

[0113] A front-facing mirror-based FAU can be used in, for example, optical switching systems to redirect optical signals to different paths. FAUs can also be used in optical test and measurement systems to adjust beam direction for testing and alignment. FAUs can also be used in laser systems to control the beam path for various applications such as laser cutting and medical procedures. FAUs can also be used in optical communication systems to manage signal direction in optical networks or for beamforming in optical antennas.

[0114] Some embodiments may include a simplified front side mirror (SFSM) in the FAU. The SFSM guides light from the optical fiber through a silicon structure embedded in a gap-filling layer and onto the lens. This design of the FAU can present several challenges. First, such a design may involve a short SFSM-to-optical fiber distance, which may be limited by tapered glass singulation. Second, the SFSM may need to be approximately 15 µm deep, which may require the FAU manufacturer to use grayscale masks and etching to re-characterize the thicker photoresist. Third, the gap-filling material (e.g., 1,12-diamine dodecane (DDO) or polyimide (PI)) and warpage may require careful consideration.

[0115] At least one embodiment of this invention may include a front-mounted array (FAU) with a simplified front mirror (SFSM). The FAU may have a waveguide-free structure. For example, the FAU can be used in a co-packaged optical device that integrates one or more optical devices, such as lasers and photodetectors, with one or more electronic devices (e.g., semiconductor devices), such as microprocessors and switches, within the same package. This integration can provide direct connectivity between optical and electronic components, enabling high-speed data transmission and communication within data centers, high-performance computing systems, and the like.

[0116] In at least one embodiment, the FAU may include a support structure (e.g., a slab) and a substrate (e.g., a partial glass substrate) on the support structure. The support structure can provide mechanical support for the FAU. The substrate may include an outer substrate layer and an inner substrate layer attached to the outer substrate layer. The inner substrate layer can be attached to the outer substrate layer using common adhesives (e.g., epoxy, silicone adhesive, etc.). The substrate can be attached to the support structure using optical adhesive.

[0117] The inner substrate layer may include one or more recesses, each recess having a recess bottom and recess sidewalls adjacent to the recess bottom. The recesses may be located at the interface between the outer and inner substrate layers. The interface may be substantially perpendicular to the support structure. The FAU may also include one or more mirrors (e.g., SFSMs) located in the one or more recesses. The mirrors may include reflective layers located on the recess bottom and recess sidewalls. The reflective layers may be formed by coating the recess bottom and recess sidewalls with a reflective material. In some embodiments, the reflective layer may be formed by coating a surface with a reflective layer material. Therefore, the reflective layer may also be referred to as an anti-reflective coating.

[0118] The reflective mirror may include an alignment mirror (e.g., a bottom reflective mirror) that provides optical reflection for automatic active alignment. The reflective mirror may also include a functional mirror (e.g., a 45° mirror) for optical path reguiding.

[0119] The FAU of this invention offers several advantages over current FAUs. Specifically, the FAU of this invention allows for deeper front-side mirror (FSM) etching within the inner substrate layer. This allows for a wider range of mode field diameter (MFD) acceptance (e.g., 45° angle and 40 μm depth). The FAU of this invention also provides excellent complementary optical interconnect (COI) face-lets for the fiber core, eliminating any 0.1° issues. The FAU of this invention also provides a simplified COI top (e.g., COIT), eliminating the need for lenses. The FAU also offers a small COIT size (e.g., approximately 750 μm glass plus 85 μm silicon bonded with a universal adhesive). The FAU also provides automatic active alignment.

[0120] Figures 1A-1C These are various views of FAU 100 according to one or more embodiments. Figure 1A It is a vertical cross-sectional view of FAU 100 including mirror 127 according to one or more embodiments. Figure 1B It is a vertical cross-sectional view of FAU 100 including aligned mirror 227 according to one or more embodiments. Figure 1C This is a perspective view of FAU 100 according to one or more embodiments. Figure 1A The vertical cross-section in the diagram is along Figure 1C The view of line A-A' in the middle. Figure 1B The vertical cross-section in the diagram is along Figure 1C The view of line B-B' in the middle.

[0121] like Figure 1A As shown, FAU 100 may include a support structure 110 (e.g., a slab) and a substrate 120 (e.g., a partially glass substrate) on the support structure 110. The support structure 110 may provide mechanical support to the substrate 120. The support structure 110 may be formed of, for example, a light-transmitting material. In at least one embodiment, the support structure 110 may be formed of alumina (sapphire), silica (e.g., silica glass), doped silica glass, etc. Other materials for the support structure 110 are also within the scope of this invention. The support structure 110 may have a substantially rectangular or square plate shape. Other shapes of the support structure 110 are also within the scope of this invention.

[0122] The substrate 120 may include an outer substrate layer 122 and an inner substrate layer 124 attached to the outer substrate layer 122. The outer substrate layer 122 may include an optically transmissive material, particularly a material that transmits ultraviolet (UV) light. The outer substrate layer 122 may include, for example, glass, such as quartz glass. Other suitable materials for the outer substrate layer 122 are within the scope of this invention. The inner substrate layer 124 may include a optically transmissive semiconductor material (e.g., silicon, germanium, silicon-germanium, etc.). In at least one embodiment, the inner substrate layer 124 may include a monocrystalline silicon layer. The inner substrate layer 124 may optionally include a polycrystalline silicon layer. Other suitable materials may be used for the inner substrate layer 124.

[0123] The inner substrate layer 124 may include a first side surface 124s1 and a second side surface 124s2 relative to the first side surface 124s1. The second side surface 124s2 may be substantially parallel to the first side surface 124s1 of the inner substrate layer 124s1. The first side surface 124s1 of the inner substrate layer 124 may be attached to the outer substrate layer 122 by a common adhesive (not shown), such as epoxy resin adhesive, silicone adhesive, etc. An interface 120i may be formed between the outer substrate layer 122 and the first side surface 124s1 of the inner substrate layer 124. The interface 120i may be substantially perpendicular to the upper surface 110us of the support structure 110. The interface 120i may extend along the entire first side surface 124s1 of the inner substrate layer 124.

[0124] An antireflective layer 125 may be formed on the second side surface 124s2 of the inner substrate layer 124. The antireflective layer 125 can reduce reflection at the second side surface 124s2 and increase light transmission. The antireflective layer 125 may include, for example, magnesium fluoride, silicon dioxide, titanium dioxide, zirconium dioxide, hafnium dioxide, yttrium fluoride, etc. Other suitable materials may be used for the antireflective layer 125. In at least one embodiment, the thickness of the antireflective layer 125 may be in the range of 50 nm to 500 nm. In some embodiments, the antireflective layer 125 may be formed by coating a surface with the antireflective layer 125 material. Therefore, the antireflective layer 125 may also be referred to as an antireflective coating 125.

[0125] The first side surface 124s1 of the inner base layer 124 may further include one or more grooves 126. The grooves 126 may be located at the interface 120i between the outer base layer 122 and the first side surface 124s1 of the inner base layer 124. The groove 126 may include a groove bottom 126b and one or more groove sidewalls 126s adjacent to the groove bottom 126b. The groove 126 may have a tapered shape. In at least one embodiment, the tapered angle between the groove sidewalls 126s and the groove bottom 126b may be in the range of 40° to 50° (e.g., 45°). The tapered angle between the groove bottom 126b and the groove sidewalls 126 may be the same or different.

[0126] In at least one embodiment, the groove 126 may have a truncated pyramid shape, wherein the base of the truncated pyramid is located at the first side surface 124s of the inner base layer 124. In at least one embodiment, the truncated pyramid shape may include a truncated four-sided pyramid shape. Other suitable truncated pyramid shapes may be used for the groove 126.

[0127] The bottom 126b of the groove may be substantially parallel to the second side surface 124s2 of the inner base layer 124. At least one groove sidewall 126s may face the upper surface 110us of the support structure 110. At least one groove sidewall 126s may face away from the upper surface 110us of the support structure 110. At least one groove sidewall 126s may face a direction substantially parallel to the upper surface 110us of the support structure 110.

[0128] FAU 100 may also include one or more mirrors 127 (e.g., SFSM) located in one or more recesses 126. Mirrors 127 may also include functional mirrors for optical path redirection (e.g., 45° mirrors). Mirrors 127 may include one or more reflective coatings located on the recess bottom 126b and recess sidewalls 126s. Mirrors 127 may include a mirror bottom portion 127b located on the recess bottom 126b and one or more mirror sidewall portions 127s located on the recess sidewalls 126s. That is, the reflective layer on the recess bottom 126b may constitute the mirror bottom portion 127b, and the reflective layer on the recess sidewalls 126s may constitute the mirror sidewall portions 127s.

[0129] In at least one embodiment, the reflective layer may cover the entire surface of the groove 126. The reflective layer may have a thickness in the range of 50 nm to 500 nm. The reflective layer may include, for example, one or more layers, including aluminum, silver, gold, etc. Other suitable materials may be used for the reflective layer.

[0130] At least one mirrored sidewall portion 127s may face the upper surface 110us of the support structure 110. At least one mirrored sidewall portion 127s may face a direction away from the upper surface 110us of the support structure 110. At least one sidewall mirror portion 126s may face a direction substantially parallel to the upper surface 110us of the support structure 110.

[0131] FAU 100 may also include a recess-filling layer 128 disposed in a recess 126 on the mirror 127. The recess-filling layer 128 may be bonded to the mirror 127 in the recess 126. The shape of the recess-filling layer 128 may be substantially the same as the shape of the recess 126 (e.g., a truncated pyramid). The outer surface of the recess-filling layer 128 may be substantially coplanar with the first side surface 124s1 of the inner substrate layer 124. In at least one embodiment, the outer surface of the recess-filling layer 128 may be bonded to the outer substrate layer 122 by an adhesive used to bond the inner substrate layer 124 to the outer substrate layer 122. The recess-filling layer 128 may include, for example, an oxide such as silicon oxide. Other suitable materials may be used for the recess-filling layer 128.

[0132] The substrate 120 may include a substantially uniform lower surface 120ls, which includes the lower surface of the outer substrate layer 122 and the lower surface of the inner substrate layer 124. The lower surface 120ls of the substrate 120 may be attached to the upper surface 110us of the support structure 110 via a first optical adhesive layer 131. The first optical adhesive layer 131 may be light-transmitting when cured and may prevent optical distortions or interference with the optical properties in the FAU 100.

[0133] The first optical adhesive layer 131 may include, for example, epoxy resin with low light absorption, UV-curable adhesive, silicone-based adhesive, optical cement, cyanoacrylate adhesive, etc. Other materials used for the first optical adhesive layer 131 are also within the scope of this invention.

[0134] like Figure 1A As shown, one or more first optical fibers 10 can also be attached to the FAU 100. Specifically, the first optical fiber 10 (optical fiber) can be attached to the upper surface 110us of the support structure 110 using optical adhesive 131. The upper surface 110us of the support structure 110 may include one or more grooves (not shown) for supporting one or more optical fibers 10 respectively. In some embodiments, the grooves may be V-grooves.

[0135] The first optical fiber 10 may include a single-mode optical fiber or a multi-mode optical fiber. In at least one embodiment, the first optical fiber 10 may not be considered an essential part of the FAU 100. That is, the first optical fiber 10 may be considered interconnected with the FAU 100, and the FAU 100 may redirect or manipulate the optical signals transmitted by the first optical fiber 10.

[0136] like Figure 1A As further shown, the first optical fiber 10 may include a core 12, a cladding layer 14 surrounding the core 12, and a coating 16 surrounding the cladding layer 14. In at least one embodiment, the first optical fiber 10 may also include a reinforcing optical fiber (not shown) on the coating 16 and a cable sheath (not shown) on the reinforcing optical fiber.

[0137] Core 12 can transmit optical signals via first optical fiber 10. Core 12 can be made of glass (e.g., quartz glass) or a hard polymer material. Other suitable materials can be used for core 12. In at least one embodiment, the glass used in core 12 may include extremely pure silicon dioxide (SiO2). Dopants such as germanium oxide, phosphorus pentoxide, or aluminum oxide can also be added to the glass in core 12 to increase the refractive index under controlled conditions.

[0138] The core 12 may be surrounded by a cladding layer 14. The cladding layer 14 may have a lower refractive index than the core 12. The cladding layer 14 may also be made of glass (e.g., quartz glass) or a hard polymer material. Other suitable materials may be used for the cladding layer 14.

[0139] In embodiments where the cladding layer 14 uses glass, the cladding layer 14 and the core 12 can be fabricated together from the same silicon dioxide-based material in a permanently fused state. Different amounts of dopants can be added to the core 12 and the cladding layer 14 to maintain the refractive index difference between them. In at least one embodiment, the core 12 may have a refractive index of approximately 1.49 at a wavelength of 1300 nm, while the cladding layer 14 may have a refractive index of approximately 1.47 at a wavelength of 1300 nm.

[0140] The cladding layer 14 may be surrounded by the coating 16. The coating 16 can serve as a protective layer, absorbing impacts, scratches, abrasions, and even moisture that could damage the cladding layer 14. The coating 16 may be color-coded to aid in the identification of the first optical fiber 10. The coating 16 may comprise, for example, one or more layers. The coating 16 may comprise acrylate-based polymer materials, silicone materials, carbon, polyimide, polypropylene, polyethylene, polyvinyl chloride, etc. Other suitable materials may be used for the coating 16.

[0141] FAU 100 may also include an upper support layer 130 located on the first optical fiber 10. In at least one embodiment, the upper support layer 130 may include a self-aligned inner base layer. The bottom surface of the upper support layer 130 may contact the coating 16 on the first optical fiber 10. The upper surface of the upper support layer 130 may be substantially coplanar with the upper surfaces of the outer base layer 122 and the inner base layer 124. The upper support layer 130 may help to fix the position of the first optical fiber 10 on the upper surface 110µs of the support structure 110. The upper support layer 130 may include, for example, silicon, glass, polymer materials, etc. Other suitable materials may be used for the upper support layer 130.

[0142] FAU 100 may further include a second optical adhesive layer 132 between the second side surface 124s2 of the inner substrate layer 124 and the upper support layer 130. The second optical adhesive layer 132 may be formed of the same material as the first optical adhesive layer 131. The second optical adhesive layer 132 may also be located between the second side surface 124s2 of the inner substrate layer 124 and the end face 10s of the first optical fiber 10. The second optical adhesive layer 132 may be adjacent to the first optical adhesive layer 131 to form an inverted T-shape. The second optical adhesive layer 132 may bond the upper support layer 130 and the end face 10s of the first optical fiber 10 to the second side surface 124s2 of the inner substrate layer 124. Specifically, the second optical adhesive layer 132 may bond the upper support layer 130 and the end face 10s of the first optical fiber 10 to an anti-reflective coating 125 located on the second side surface 124s2 of the inner substrate layer 124.

[0143] like Figure 1A As shown, the first optical fiber 10 can be disposed on the upper surface 110us of the support structure 110, such that light transmitted by the core 12 of the first optical fiber 10 is transmitted as a beam 21 from the end face 10s of the first optical fiber 10 to the mirror 127 in the inner substrate layer 124. Specifically, the beam 21 can be transmitted in an x-direction substantially parallel to the upper surface 110us of the support structure 110. Specifically, the beam 21 can pass through the second optical adhesive layer 132, through the anti-reflective coating 125, through the inner substrate layer 124 and reach the mirror 127.

[0144] The groove 126 and the mirror 127 formed in the groove 126 can be located in the inner substrate layer 124 such that the core 12 of the first optical fiber 10 is substantially aligned in the x-direction with the groove sidewall 126s, and thus with the mirror sidewall portion 127s of the mirror 127. Specifically, the core 12 can be aligned with the mirror sidewall portion 127s facing the support structure 110. The beam 21 can be reflected from the mirror sidewall portion 127s into a reflected beam 22. The reflected beam 22 can be formed at a 90° angle to the beam 21. In at least one embodiment, the reflected beam 22 can be reflected in the z-direction substantially parallel to the first side surface 124s1 of the inner substrate layer 124 and substantially perpendicular to the upper surface 110us of the support structure 110.

[0145] FAU 100 may also include an anti-reflection groove 146 located on the bottom surface of the inner substrate layer 124. The reflected beam 22 may be reflected onto the anti-reflection groove 146. The anti-reflection groove 146 helps ensure that the reflected beam 22 can be transmitted out of the inner substrate layer 124 with low optical loss and into the first optical adhesive layer 131 (e.g., into the support structure 110).

[0146] The antireflective trench 146 may include an inner wall coated with an antireflective coating 145. The antireflective coating 145 may be formed of the same material as the antireflective coating 125 on the second side surface 124s2 of the antireflective trench 146. A trench fill layer 148 may be formed on the trench 146 in the antireflective coating 145. The trench fill layer 148 may be formed of the same material as the trench fill layer 128. Specifically, the trench fill layer 148 may include an oxide (e.g., silicon oxide). In at least one embodiment, the trench fill layer 148 may include DDO. The lower surface of the trench fill layer 148 may be substantially coplanar with the bottom surface of the inner substrate layer 124.

[0147] FAU 100 may also include one or more photodiodes (not shown) that can receive reflected light beams 22 through trench fill layer 148. The photodiodes may be located, for example, on the upper surface 110µs of support structure 110. Alternatively or additionally, the photodiodes may be located within support structure 110 or on the lower surface of support structure 110. The photodiodes may be included as part of a photodiode array, which may be incorporated into FAU 100.

[0148] Figure 1B The illustrated embodiments and Figure 1A The illustrated embodiments are similar. For the sake of brevity, similar components will not be discussed further. Figure 1B As shown, the inner base layer 124 may further include an alignment recess 226. Although in Figure 1BNot shown, but FAU 100 may optionally include an anti-reflective groove (similar to anti-reflective groove 146) located below the alignment recess 226. The alignment recess 226 may be formed in the first side surface 124s1 of the inner substrate layer 124 and at the interface 120i between the outer substrate layer 122 and the inner substrate layer 124. The alignment recess 226 may be adjacent to the recess 126, but offset in the z-direction compared to the recess 126. Specifically, the distance between the alignment recess 226 and the upper surface 110us of the support structure 110 may be less than the distance between the recess 126 and the upper surface 110us of the support structure 110.

[0149] Alignment recess 226 may have a size and shape substantially similar to that of recess 126 in inner base layer 124. Alignment recess 226 may have an alignment recess bottom 226b substantially similar to the recess bottom 126b and one or more alignment recess sidewalls 226s substantially similar to the recess sidewalls 126s.

[0150] FAU 100 may also include an alignment mirror 227 formed in an alignment recess 226. The alignment mirror 227 can provide an automatic active alignment process in FAU 100. The alignment mirror 227 may be formed from a reflective layer on the bottom 226b of the alignment recess and on the sidewalls 226s of the alignment recess. The reflective layer may be substantially similar to the reflective layer forming the mirror 127. The alignment mirror 227 may include a bottom alignment mirror portion 227b formed on the bottom 226b of the alignment recess and one or more alignment mirror sidewall portions 227s formed on one or more alignment recess sidewalls 226s. The alignment mirror sidewall portions 227s may be adjacent to the bottom alignment mirror portion 227b.

[0151] Alignment recess filler layer 228 may be formed in alignment recess 226 on alignment mirror 227. Alignment recess filler layer 228 may be bonded to alignment mirror 227 in alignment recess 226. The shape of alignment recess filler layer 228 may be substantially the same as the shape of alignment recess 226 (e.g., truncated pyramid shape). The outer surface of alignment recess filler layer 228 may be substantially coplanar with the first side surface 124s1 of inner substrate layer 124. In at least one embodiment, the outer surface of alignment recess filler layer 228 may be bonded to outer substrate layer 122 by an adhesive that bonds inner substrate layer 124 to outer substrate layer 122. Alignment recess filler layer 228 may comprise, for example, an oxide such as silicon oxide. Other suitable materials may be used for recess filler layer 228.

[0152] The second optical fiber 20 (alignment fiber) may be attached to the upper surface 110us of the support structure 110. The second optical fiber 20 may have a structure substantially similar to that of the first optical fiber 10 and may be located on the upper surface 110us of the support structure 110 adjacent to the first optical fiber 10. The end face 20s of the second optical fiber 20 may be bonded to the second side surface 124s2 of the inner substrate layer 124 (e.g., bonded to the anti-reflective coating 125 on the second side surface 124s2 of the inner substrate layer 124). The upper support layer 130 may also be located on the second optical fiber 20.

[0153] like Figure 1B As shown, the second optical fiber 20 can be disposed on the upper surface 110us of the support structure 110, such that light transmitted by the core 12 of the second optical fiber 20 is transmitted as a beam 31 from the end face 20s of the second optical fiber 20 to the alignment mirror 227 in the inner substrate layer 124. Specifically, the beam 31 can be transmitted in the x direction substantially parallel to the upper surface 110us of the support structure 110. Specifically, the beam 31 can be transmitted through the second optical adhesive layer 132, through the anti-reflective coating 125, through the inner substrate layer 124 and reach the alignment mirror 227.

[0154] Alignment groove 226 and alignment mirror 227 formed in alignment groove 226 can be located in inner substrate layer 124 such that core 12 of second fiber 20 is substantially aligned in the x-direction with bottom 226b of alignment groove, and thus with bottom portion 227b of alignment mirror 227. Beam 31 can be reflected by bottom portion 227b of alignment mirror as reflected beam 32. Reflected beam 32 can be reflected directly back (e.g., 180°) the path of beam 31. In at least one embodiment, reflected beam 32 can be reflected back into core 12 of second fiber 20 in the x-direction. In a final embodiment, the center reflected beam 32 can substantially coincide with the center of beam 31 and core 12 of second fiber 20. Reflected beam 32 can be guided into core 12 at end face 20s of second fiber 20 and propagate out of FAU 100 within core 12. Reflected beam 32 can be used, for example, to perform automatic active alignment.

[0155] refer to Figure 1C For ease of understanding, Figure 1C The anti-reflective coating 125, the second optical adhesive layer 132, and the upper support layer 130 are omitted. For example... Figure 1CAs shown, the second optical fiber 20 can be substantially parallel to the first optical fiber 10 on the upper surface 110µs of the support structure 110. The alignment groove 226 and the alignment mirror 227 can be offset in the z-direction from the groove 126 and mirror 127 by an offset distance Do. The offset distance Do can be substantially the same as the height in the z-direction of the bottom portion 227b of the alignment mirror. In at least one embodiment, the offset distance Do can be greater than the height of the bottom portion 227b of the alignment mirror. In at least one embodiment, the offset distance Do can be in the range of 5µm to 100µm.

[0156] Figures 2A-2B This is a detailed vertical cross-sectional view of FAU 100 according to one or more embodiments. Figure 2A This is a detailed vertical cross-sectional view of FAU 100 including mirror 127 according to one or more embodiments. Figure 2B This is a detailed vertical cross-sectional view of the FAU 100 including the aligned mirror 227 according to one or more embodiments.

[0157] like Figure 2A As shown, in at least one embodiment, the inner substrate layer 124 (e.g., a silicon layer, a silicon wafer, etc.) may have a width D1 of 50 μm to 125 μm (e.g., about 85 μm) in the x-direction. The outer substrate layer 122 may have a width of 500 μm to 1000 μm (e.g., about 750 μm) in the x-direction.

[0158] The distance D2 between the second side surface 124s2 of the inner substrate layer 124 and the mirror sidewall portion 127s at the center of the beam 21 can be from 30 μm to 100 μm (e.g., about 65 μm). The thickness D3 of the anti-reflection trench 146 (e.g., the thickness of the trench filling layer 148) can be from 1 μm to 10 μm (e.g., about 5 μm). The thickness D4 of the support structure 110 can be from 100 μm to 400 μm (e.g., about 250 μm). The thickness D5 of the first optical adhesive layer 131 can be from 5 μm to 40 μm (e.g., about 20 μm). The thickness D6 of the second optical adhesive layer 132 (e.g., the distance between the anti-reflection coating 125 and the end face 10s of the first optical fiber 10) can also be from 5 μm to 40 μm (e.g., about 20 μm).

[0159] The cross-sectional radius R10 of the first optical fiber 10 can be from 20 μm to 200 μm (e.g., about 62.5 μm). The core 12 can have a diameter D12 from 9 μm to 62.5 μm. The cladding layer 14 can have a thickness T14 from 30 μm to 100 μm. The coating 16 can have a thickness T16 from 10 μm to 60 μm.

[0160] In at least one embodiment, the area of ​​the mirror sidewall portion 127s can depend on the diameter D12 of the core 12 and the combination distance D2+D6 (i.e., the distance D2 between the second side surface 124s2 of the inner substrate layer 124 and the mirror sidewall portion 127s plus the distance D6 between the antireflective coating 125 and the end face 10s of the first optical fiber 10). The area of ​​the mirror sidewall portion 127s should be sufficient to accommodate the beam 21. If the area of ​​the mirror sidewall portion 127s is too small, only a portion of the beam 21 can illuminate the mirror sidewall portion 127s and be reflected as a reflected beam 22. Furthermore, considering that the diameter of the beam 21 illuminating the mirror sidewall portion 127s increases with the increase of the combination distance D2+D6, the ratio of the area of ​​the mirror sidewall portion 127s to the diameter D12 of the core 12 should increase with the increase of the combination distance D2+D6. In at least one embodiment, for a combined distance D2+D6 between 35 μm and 140 μm (e.g., about 85 μm), the area of ​​the mirror sidewall portion 127s can be at least twice the cross-sectional area of ​​the core 12.

[0161] like Figure 2B As shown, the width D7 of the alignment mirror bottom portion 227b can be substantially the same as the width of the alignment groove bottom portion 226b. In at least one embodiment, the width D7 of the alignment mirror bottom portion 227b can be from 5 μm to 50 μm (e.g., about 20 μm). The depth D8 of the alignment groove 226 (e.g., the thickness of the alignment groove filling layer 228) can be from 10 μm to 70 μm (e.g., about 40 μm). It should be noted that the groove 126 and the mirror 127 (see...) Figure 2A The dimensions of the alignment groove 226 and the alignment mirror 227 can be substantially the same as the dimensions of the alignment groove 226 and the alignment mirror 227, respectively. Therefore, for example, the width of the bottom portion 127b of the mirror can be substantially the same as the width D7 of the bottom portion 227b of the alignment mirror, and the depth of the groove 126 can be substantially the same as the depth D8 of the alignment groove 226.

[0162] The distance D9 between the second side surface 124s2 of the inner substrate layer 124 and the bottom portion 227b of the alignment mirror can be from 20 μm to 70 μm (e.g., about 45 μm). The distance between the anti-reflective coating 125 and the end face 20s of the second optical fiber 20 (e.g., the thickness of the second optical adhesive layer 132) can be from 5 μm to 40 μm (e.g., about 20 μm).

[0163] The size and shape of the second optical fiber 20 can be substantially similar to those of the first optical fiber 10. Specifically, the cross-sectional radius R20 of the second optical fiber 20 can be in the range of 20 μm to 100 μm (e.g., about 62.5 μm). Furthermore, the area of ​​the bottom portion 227b of the alignment mirror can depend on the diameter D12 of the core 12 and the combined distance D9+D10 (i.e., the distance D9 between the second side surface 124s2 of the inner substrate 124 and the bottom portion 227b of the alignment mirror plus the distance D10 between the anti-reflective coating 125 and the end face 20s of the second optical fiber 20). The area of ​​the bottom portion 227b of the alignment mirror should be sufficient to accommodate the beam 31. If the area of ​​the bottom portion 227b of the alignment mirror is too small, only a portion of the beam 31 can illuminate the bottom portion 227b of the alignment mirror and be reflected as a reflected beam 32. Furthermore, considering that the diameter of the beam 31 illuminating the bottom portion 227b of the alignment mirror increases with the increase of the combination distance D9+D10, the ratio of the area of ​​the bottom portion 227b of the alignment mirror to the diameter D12 of the core 12 should increase with the increase of the combination distance D9+D10. In at least one embodiment, for a combination distance D9+D10 of 25 μm to 120 μm (e.g., about 65 μm), the area of ​​the bottom portion 227b of the alignment mirror can be at least twice the cross-sectional area of ​​the core 12.

[0164] Figures 3A-3G Various intermediate structures that can be formed in a method of manufacturing FAU 100 according to one or more embodiments are shown. Figure 3A It is a vertical cross-sectional view of the grooves 126, 226 formed in the inner base layer 124 according to one or more embodiments.

[0165] The inner substrate layer 124 may include, for example, a silicon wafer. In at least one embodiment, a plurality of recesses 126, 226 may be simultaneously formed in the silicon wafer during a wafer-level process.

[0166] The grooves 126 and 226 can be formed in the inner substrate layer 124, for example, by a photolithography process in which a photoresist layer (not shown) is deposited on the inner substrate layer 124 and patterned to form openings in the photoresist layer corresponding to the grooves 126 and 226. The inner substrate layer 124 can then be etched (e.g., by wet etching, dry etching, etc.) through the openings in the photoresist layer. In at least one embodiment, wet etching can be used to form the grooves 126 and 226.

[0167] Etching can form grooves 126, 226 with a depth D8 of 10 μm to 70 μm (e.g., about 40 μm) and a taper angle θ of 40° to 50° (e.g., 45°). Etching can also form groove bottoms 126b, 226b and groove sidewalls 126s, 226s. Groove bottoms 126b, 226b can be formed with a width D7 of 5 μm to 50 μm (e.g., about 20 μm). Groove sidewalls 126s can be formed with a length of 50 μm to 60 μm (e.g., about 56.6 μm for a depth D8 of 40 μm and a taper angle of 45°). The photoresist layer can then be removed from the surface of the inner substrate layer 124 (e.g., by ashing or other suitable processes). It should be noted that the same process used to form groove 126 can also be used to form alignment groove 226. Other suitable methods can be used to form the groove 126 in the inner base layer 124.

[0168] Figure 3B This is a vertical cross-sectional view of the inner base layer 124 including mirror surfaces 127, 227 according to one or more embodiments. In at least one embodiment, mirror surfaces 127, 227 can be formed on the recess bottoms 126b, 226b and recess sidewalls 126s, 226s of the recesses 126, 226 by depositing reflective layers on the recess bottoms 126b, 226b and recess sidewalls 126s, 226s. Figure 3B As shown, the reflective layer or coating can be conformally formed on the bottom 126b, 226b of the recess and the sidewalls 126s, 226s of the recess. For example, the reflective layer can be deposited using deposition processes such as Chemical Vapor Deposition (CVD), Plasma-Enhanced CVD (PECVD), Physical Vapor Deposition (PVD), spin coating, lamination, or other suitable deposition techniques. The reflective layer can be deposited with a thickness ranging from 50 nm to 500 nm. Other suitable methods for forming the mirror 127 can be used.

[0169] Then, a groove filling layer 128 can be formed in the grooves 126, 226 on the reflective surfaces 127, 227. The groove filling layers 128, 228 can be formed, for example, by depositing a groove filling material (e.g., an oxide such as silicon oxide) in the grooves 126, 226. The groove filling material can be deposited, for example, using a deposition process such as CVD, PECVD, PVD, spin coating, lamination, or other suitable deposition techniques. The groove filling material can be deposited to fill the grooves 126, 226. Other suitable methods can be used to form the groove filling layers 128, 228.

[0170] After the groove-filling material is deposited and cured, a planarization process (e.g., chemical mechanical polishing, CMP) can be performed. The planarization process can remove any reflective coating and any groove-filling material formed outside the grooves 126, 226 on the surface of the inner substrate layer 124. The planarization process can also make the upper surfaces of the groove-filling material and the reflective coating (e.g., mirrors 127, 227) substantially coplanar with the surface of the inner substrate layer 124. The planarization process may include, for example, chemical mechanical polishing (CMP). Other suitable methods may be used in the planarization process.

[0171] Figure 3C This is a vertical cross-sectional view of an inner substrate layer 124 including an anti-reflection trench 146 according to one or more embodiments. The anti-reflection trench 146 can be deposited on the inner substrate layer 124, for example, by photolithography, and patterned to form openings in the photoresist layer corresponding to the anti-reflection trench 146. The inner substrate layer 124 can then be etched (e.g., by wet etching, dry etching, etc.) through the openings in the photoresist layer.

[0172] Etching can form the anti-reflective trench 146 to have a depth Dt greater than the depth D8 of the recess 126. In at least one embodiment, the depth Dt can be from 71 μm to 120 μm (e.g., about 90 μm). Etching can also form the anti-reflective trench 146 to have a thickness D3' greater than the final thickness D3 (e.g., greater than about 10 μm). The sidewalls of the anti-reflective trench 146 can be substantially perpendicular to the surface of the inner substrate layer 124. The photoresist layer can then be removed from the surface of the inner substrate layer 124 (e.g., by ashing or other suitable processes). It should be noted that the same process used to form the anti-reflective trench 146 can also be used to form the alignment recess 226. Other suitable methods for forming the anti-reflective trench 146 in the inner substrate layer 124 can be used.

[0173] Subsequently, an antireflective coating 145 can be formed in the antireflective trench 146. For example, the antireflective coating 145 can be formed by depositing the antireflective coating 145 on the bottom and sidewalls of the antireflective trench 146. The antireflective coating 145 can be deposited, for example, using deposition processes such as CVD, PECVD, PVD, spin coating, lamination, or other suitable deposition techniques. The antireflective coating 145 can be deposited to have a thickness of 50 nm to 500 nm. Other suitable methods for forming the antireflective coating 145 can be used.

[0174] Subsequently, a planarization process can be performed. The planarization process can remove any antireflective coating formed outside the antireflective trench 146 on the surface of the inner substrate layer 124. The planarization process can also make the upper surface of the antireflective coating substantially coplanar with the surface of the inner substrate layer 124. The planarization process can include, for example, chemical mechanical polishing (CMP). Other suitable methods can be used in the planarization process.

[0175] Figure 3D This is a vertical cross-sectional view of an inner substrate layer 124 including a trench fill layer 148 in an antireflective trench 146 according to one or more embodiments. The trench fill layer 148 may be formed (e.g., conformally formed) in the antireflective trench 146, located on the bottom and sidewalls of the antireflective trench 146. The trench fill layer 148 may be formed, for example, by depositing a trench filler material in the trench 126. The trench filler material may include, for example, oxides (e.g., silicon oxide) or DDO. For example, the trench filler material may be deposited using deposition processes such as CVD, PECVD, PVD, spin coating, lamination, or other suitable deposition techniques. Trench filler material may be deposited to fill the antireflective trench 146. Other suitable methods may be used to form the trench fill layer 148.

[0176] Subsequently, a planarization process can be performed. The planarization process can remove any trench filler material formed outside the anti-reflective trenches 146 on the surface of the inner substrate layer 124. The planarization process can form a first side surface 124s1 of the inner substrate layer 124. The planarization process can also make the upper surface of the trench filler layer 148 substantially coplanar with the first side surface 124s1 of the inner substrate layer 124. The planarization process can include, for example, chemical mechanical polishing (CMP). Other suitable methods can be used in the planarization process.

[0177] Figure 3E This is a vertical cross-sectional view of an inner base layer 124 attached to an outer base layer 122 according to one or more embodiments. The substrate 120 can then be formed by attaching the inner base layer 124 to the outer base layer 122.

[0178] An adhesive layer (not shown) such as a silicone adhesive or epoxy adhesive can be applied to the surface of the outer substrate layer 122. The adhesive layer can be applied, for example, by spraying, spin coating, lamination, etc. Then, the inner substrate layer 124 can be flipped so that its first side surface 124s1 faces the surface of the outer substrate layer 122. The inner substrate layer 124 can then be lowered onto the outer substrate layer 122. The inner substrate layer 124 and the outer substrate layer 122 can then be clamped together and the adhesive cured (e.g., in a curing oven).

[0179] After the adhesive has cured, the surface of the inner substrate layer 124 opposite to the outer substrate layer 122 can be ground and polished to form a second side surface 124s2 of the inner substrate layer 124. An antireflective coating 125 can then be formed on the second side surface 124s2 of the inner substrate layer 124. For example, the antireflective coating 125 can be formed by depositing the antireflective coating 125 on the second side surface 124s2. For example, the antireflective coating 125 can be deposited using a deposition process such as CVD, PECVD, PVD, spin coating, lamination, or other suitable deposition techniques. The antireflective coating 125 can be deposited to have a thickness between 50 nm and 500 nm. Other suitable methods can be used to form the antireflective coating 125.

[0180] Figure 3F This is a vertical cross-sectional view of the substrate 120 after a dicing process has been performed, according to one or more embodiments. For example, a die saw may be used to perform the dicing process. [The image shows a view along...] Figure 3F The dashed lines in the code perform the cutting. For example... Figure 3F As shown, cutting can remove a portion of the anti-reflective groove 146. Specifically, cutting can result in the anti-reflective groove 146 having a thickness D3 of 1 μm to 10 μm (e.g., about 5 μm).

[0181] Figure 3G This is a vertical cross-sectional view of the base 120 on the support structure 110 according to one or more embodiments. Figure 3G As shown, a first optical adhesive layer 131 (e.g., a UV-curable optical adhesive) can be formed on the upper surface 110us of the support structure 110 (e.g., a sapphire plate). The substrate 120 can then be rotated 90° and positioned above the support structure 110 such that the lower surface 120ls of the substrate 120 faces the upper surface 110us of the support substrate 110. For example, an electromechanical pick-and-place (PNP) machine can be used to position the substrate 120. The substrate 120 can then be lowered onto the first optical adhesive layer 131 such that the lower surface 120ls of the substrate 120 (e.g., including anti-reflective grooves 146) contacts the first optical adhesive layer 131, and the interface 120i is substantially perpendicular to the support structure 110.

[0182] Then, a second optical adhesive layer 132 can be applied to the antireflective coating 125 on the second side surface 124s2 of the inner substrate layer 124. The second optical adhesive layer 132 can be applied in a similar manner to the first optical adhesive layer. Then, the first optical fiber 10 can be placed on the first optical adhesive layer 131 such that the end face 10s of the first optical fiber 10 contacts the second optical adhesive layer 132. Then, an adhesive layer (not shown) can be applied to the top of the first optical fiber 10, and then the upper support layer 130 can be connected to the first optical fiber 10 and to the inner substrate layer 124 via the second optical adhesive layer 132. The structures can then be clamped together (e.g., between the substrate 120 / upper support layer 130 and support structure 110). The first optical adhesive layer 131 and the second optical adhesive layer 132 can then be cured (e.g., using UV light).

[0183] Figure 4 This is a flowchart illustrating a method for forming FAU 100 according to one or more embodiments. Step 410 of the method may include forming grooves 126, 226 in an inner substrate layer 124, wherein the grooves 126, 226 include groove bottoms 126b, 226b and groove sidewalls 126s, 226s adjacent to the groove bottoms 126b, 226b. Step 420 may include forming mirror surfaces 127, 227 including a reflective coating on the groove bottoms 126b, 226b and the groove sidewalls 126s, 226s. Step 430 may include attaching the inner substrate layer 124 to an outer substrate layer 122 to form a substrate 120 including the inner substrate layer 124 and the outer substrate layer 122, wherein the grooves 126, 226 are located at the interface between the outer substrate layer 122 and the inner substrate layer 124. Step 440 may include attaching the substrate 120 to a support structure 110 such that the interface 120i is substantially perpendicular to the support structure 110.

[0184] Figures 5A-5B A first alternative design of the FAU 100 according to one or more embodiments is shown. Figure 5A This is a plan view (top view) of a first alternative design of FAU 100 according to one or more embodiments. Figure 5B This is a vertical cross-sectional view of a first alternative design of FAU 100 according to one or more embodiments. Figure 5B The vertical cross-section in the diagram is along Figure 5A The view of line C-C' in the middle.

[0185] exist Figure 5A For ease of understanding, the upper support layer 130 and the first optical adhesive layer 131 are omitted. Figure 5AAs shown, in the first alternative design, the area of ​​the support structure 110 in the plan view can be larger than the area of ​​the substrate 120. The upper surface 110us of the support structure 110 may include a plurality of grooves 511 extending along the y-direction. The plurality of grooves 511 can respectively accommodate a plurality of first optical fibers 10 and second optical fibers 20 (alignment fibers). The number of first optical fibers 10 and second optical fibers 20 need not be limited to any specific number. The plurality of first optical fibers 10 and second optical fibers 20 can be fixed in place by a first optical adhesive layer (not shown) and a second optical adhesive layer 132.

[0186] The inner substrate layer 124 may include a plurality of mirrors 127 and an alignment mirror 227. Mirrors 127 may be configured to receive a beam 21 from a first optical fiber 10. Alignment mirror 227 may be configured to receive a beam 31 from a second optical fiber 20.

[0187] exist Figure 5B In the diagram, for ease of understanding, the position of the upper support layer 130 is indicated by dashed lines. For ease of understanding, the positions of the multiple reflecting mirrors 127 and the alignment mirror 227 are also indicated by dashed lines.

[0188] like Figure 5B As shown, a plurality of first optical fibers 10 and second optical fibers 20 can be located on the lateral sidewalls of a plurality of trenches 511. This helps to ensure that the first optical fibers 10 are properly axially aligned with the plurality of reflectors 127, and that the second optical fibers 20 are properly axially aligned with the alignment mirror surface 227. The plurality of first optical fibers 10 and second optical fibers 20 can be secured in the plurality of trenches 511 by a first optical adhesive layer 132.

[0189] like Figure 5B As further shown, the upper support layer 130 in the first alternative design may have an inverted U-shape. The upper support layer 130 may also include a plurality of projections 535 projecting downward between the plurality of first optical fibers 10 and second optical fibers 20. In at least one embodiment, the projections 535 may include V-shaped projections. With this configuration, the upper support layer 130 can restrict the lateral movement of the plurality of first optical fibers 10 and second optical fibers 20 in the z-direction and the y-direction.

[0190] A first alternative design for FAU 100 may also include a photodiode array 540. The photodiode array 540 may be attached to the lower surface of the support structure 110. The photodiode array 540 may include a plurality of photodiodes 541 that respectively receive reflected light beams 22 from a plurality of mirrors 127. The photodiode array 540 may also include electronic circuitry and means for processing the reflected light beams 22 into electrical signals and utilizing these electrical signals.

[0191] Figure 6 This is a vertical cross-sectional view of a second alternative design of the FAU 100 according to one or more embodiments. (See attached image.) Figure 6 As shown, the second alternative design can be combined with Figures 1A-1C The original design is substantially the same. However, in the second alternative design, FAU100 may include a photodiode array 540 mounted on a substrate 120 relative to the support structure 110. The photodiode array 540 may be attached to the substrate 120 via a third optical adhesive layer 531. The third optical adhesive layer 531 may be substantially the same as the first optical adhesive layer 131 and the second optical adhesive layer 132.

[0192] like Figure 6 As further shown, the groove 126 and the mirror 127 can be configured in the inner substrate layer 124 such that the light beam 21 from the first optical fiber 10 can illuminate the mirror sidewall portion 127s of the mirror 127. Specifically, the light beam 21 can illuminate the back support structure 110 and be directed toward the mirror sidewall portion 127s of the photodiode array 540. The light beam 21 can be reflected by the mirror sidewall portion 127s to form a reflected light beam 22 substantially perpendicular to the interface 120i. The reflected light beam 22 can exit the inner substrate layer 124 through the anti-reflection trench 146. The reflected light beam 22 can then enter the photodiode array 540 to be received by the photodiode 541.

[0193] Figure 7 This is a vertical cross-sectional view of a third alternative design of the FAU 100 according to one or more embodiments. (See attached image.) Figure 7 As shown, the third alternative design for FAU 100 can essentially be similar to... Figures 1A-1C The embodiment shown. Similar to the previous embodiment, in the third alternative design, FAU 100 may include a support structure 110, a substrate 120, and an upper support layer 130. However, in the third alternative design, the upper support layer 130 may have an L-shaped cross-section. A portion of the upper support layer 130 may be attached to the upper surface of the substrate 120, and a portion of the upper support layer 130 may be attached to a second side surface 124s2 of the inner substrate layer 124 (e.g., to the anti-reflective coating 125). The upper support layer 130 may be attached to the substrate 120 via an adhesive layer (not shown) (e.g., epoxy adhesive, silicone adhesive, etc.).

[0194] like Figure 7As further shown, a trench 511 may be formed on the upper surface 110us of the support structure 110. In some embodiments, the trench 511 may be a V-shaped trench. The trench 511, the second side surface 124s2 of the inner base layer 124, and the upper support layer 130 may together form an attachment port (fiber receptacle) of the FAU 100 for receiving the first optical fiber 10 (and also for receiving the second optical fiber (not shown)).

[0195] A first optical adhesive layer (not shown) may be formed in the trench 511. A second optical adhesive layer (not shown) may be formed on the anti-reflective coating 125. The first optical fiber 10 may then be inserted into the attachment port and attached to the FAU 100 via the first and second optical adhesive layers.

[0196] Now for reference Figures 1A to 7 The fiber array unit 100 may include a support structure 110 and a substrate 120 on the support structure 110. The substrate 120 includes an outer substrate layer 122 and an inner substrate layer 124. The inner substrate layer 124 is attached to the outer substrate layer 122 and includes grooves 126 and 226. Each groove 126 and 226 includes a groove bottom 126b and 226b and a groove sidewall 126s and 226s adjacent to the groove bottoms 126b and 226b. The grooves 126 and 226 may be located at the interface 120i between the outer substrate layer 122 and the inner substrate layer 124, and the interface 120i may be substantially perpendicular to the support structure 110. The fiber array unit 100 also includes mirrors 127 and 227, which include reflective layers located on the groove bottoms 126b and 226b and the groove sidewalls 126s and 226s.

[0197] In one embodiment, the groove sidewalls 126s, 226s may include tapered groove sidewalls 126s, 226s. In one embodiment, the tapered groove sidewalls 126s, 226s may include a cone angle θ of 40° to 50°. In one embodiment, the mirror surfaces 127, 227 may include mirror bottom portions 127b, 227b located on the groove bottoms 126b, 226b and mirror sidewall portions 127s, 227s located on the groove sidewalls 126s, 226s. In one embodiment, the inner base layer 124 may include a first side surface 124s1 and a second side surface 124s2, the first side surface 124s1 including grooves 126, 226, and the second side surface 124s2 relative to and substantially parallel to the first side surface 124s1 of the inner base layer 124. In one embodiment, the fiber array unit 100 may further include groove filling layers 128, 228 located in grooves 126, 226 on mirrors 127, 227, wherein the outer surfaces of the groove filling layers 128, 228 may be substantially coplanar with the first side surface 124s1 of the inner substrate layer 124. In one embodiment, the fiber array unit 100 may further include an anti-reflective coating 125 on the second side surface 124s2 of the inner substrate layer 124. The support structure 110 may include an upper surface including a groove 511 configured to support the first optical fiber 10 such that the end face 10s of the first optical fiber 10 faces the second side surface 124s2 of the inner substrate layer 124. In one embodiment, mirrors 127, 227 may include functional mirrors 127, 227, and the groove 511 may be configured to support the first optical fiber 10 such that the core 12 of the first optical fiber 10 may be substantially aligned with the groove sidewall 126s. In one embodiment, the fiber array unit 100 may further include a first optical adhesive layer 131 located between the substrate and the support structure 110 and between the first optical fiber 10 and the support structure 110, and a second optical adhesive layer 132 located between the second side surface 124s2 of the inner substrate layer 124 and the end face 10s of the first optical fiber 10. In one embodiment, the fiber array unit 100 may further include an upper support layer located on the first optical fiber 10, wherein the second optical adhesive layer 132 may be located between the second side surface 124s2 of the inner substrate layer 124 and the upper support layer. In one embodiment, the first side surface 124s1 of the inner substrate layer 124 may further include an alignment groove, the alignment groove including an alignment groove bottom and an alignment groove sidewall adjacent to the alignment groove bottom, and the alignment groove may be adjacent to the groove 126 at the interface 120i between the outer substrate layer 122 and the inner substrate layer 124.In one embodiment, the fiber array unit 100 may further include an alignment mirror 227, which includes a reflective coating located at the bottom of the alignment groove and on the sidewalls of the alignment groove. The alignment mirror may include a bottom portion 227b of the alignment mirror located at the bottom of the alignment groove and a sidewall portion 227s of the alignment mirror located on the sidewalls of the alignment groove. In one embodiment, the support structure 110 may include an upper surface including a groove 511 configured to support the second fiber 20, such that the end face 20s of the second fiber 20 faces the second side surface 124s2 of the inner substrate layer 124, and that the core 12 of the second fiber 20 can be substantially aligned with the bottom portion 227b of the alignment mirror.

[0198] Refer again Figures 1A to 7 The method of forming the fiber array unit 100 may include forming grooves 126, 226 in an inner substrate layer 124, wherein the grooves 126, 226 may include groove bottoms 126b, 226b and groove sidewalls 126s, 226s adjacent to the groove bottoms 126b, 226b, forming mirror surfaces 127, 227 including a reflective coating on the groove bottoms 126b, 226b and the groove sidewalls 126s, 226s, attaching the inner substrate layer 124 to an outer substrate layer 122 to form a substrate including the inner substrate layer 124 and the outer substrate layer 122, wherein the grooves 126, 226 may be located at an interface 120i between the outer substrate layer 122 and the inner substrate layer 124, and attaching the substrate to a support structure 110 such that the interface 120i may be substantially perpendicular to the support structure 110.

[0199] In one embodiment, the step of forming grooves 126, 226 may include forming groove sidewalls 126s, 226s to include tapered groove sidewalls 126s, 226s, the tapered groove sidewalls 126s, 226s including a cone angle θ of 40° to 50°. In one embodiment, the step of forming grooves 126, 226 may include forming grooves 126, 226 in a first side surface 124s1 of an inner base layer 124, wherein the inner base layer 124 may include a second side surface 124s2 relative to and substantially parallel to the first side surface 124s1 of the inner base layer 124. In one embodiment, the method may further include forming groove filling layers 128 and 228 in grooves 126 and 226 on the reflective mirror surfaces 127 and 227, wherein the outer surfaces of the groove filling layers 128 and 228 may be substantially coplanar with the first side surface 124s1 of the inner base layer 124, and an anti-reflective coating 125 is formed on the second side surface 124s2 of the inner base layer 124. In one embodiment, the step of attaching the substrate to the support structure 110 may include attaching the substrate to the support structure 110 such that a groove 511 in the upper surface of the support structure 110 supports a first optical fiber 10, the first optical fiber 10 including an end face 10s facing the second side surface 124s2 of the inner base layer 124, and the core 12 of the first optical fiber 10 may be substantially aligned with the mirror sidewall portion 127s.

[0200] Refer again Figures 1A to 7 The fiber array unit 100 may include a support structure 110, which includes a plurality of trenches 511 configured to support a plurality of first optical fibers 10 respectively. The substrate on the support structure 110 includes an outer substrate layer 122. The fiber array unit 100 also includes an inner substrate layer 124 attached to the outer substrate layer 122, and the inner substrate layer 124 includes a plurality of grooves 126. Each groove 126 includes a groove bottom 126b and a groove sidewall 126s adjacent to the groove bottom 126b. The plurality of grooves 126 may be located at an interface 120i between the outer substrate layer 122 and the inner substrate layer 124, and the interface 120i may... The fiber array unit 100, substantially perpendicular to the support structure 110, also includes a plurality of functional mirrors 127, each including a reflective coating on the bottom 126b and sidewalls 126s of the recess. The plurality of functional mirrors 127 can be configured to reflect the light beam 21 from the first fiber 10s in a direction substantially parallel to the interface 120i between the outer substrate layer 122 and the inner substrate layer 124. The fiber array unit 100 also includes a photodiode array 540, which includes a plurality of photodiodes 541 configured to receive the reflected light beams 22 from the plurality of functional mirrors 127, respectively.

[0201] The components of several embodiments are summarized above to facilitate a better understanding of the views expressed in the embodiments of this utility model by those skilled in the art. Those skilled in the art should understand that they can design or modify other processes and structures based on the embodiments of this utility model to achieve the same purpose and / or advantages as the embodiments described herein. Those skilled in the art should also understand that such equivalent processes and structures do not depart from the spirit and scope of this utility model, and that they can make various changes, substitutions, and replacements without departing from the spirit and scope of this utility model.

Claims

1. A semiconductor device, characterized in that, include: One supporting structure; A base, located on the supporting structure, the base comprising: An outer basal layer; and An inner substrate layer, attached to the outer substrate layer and including a groove, the groove including a groove bottom and a groove sidewall adjacent to the groove bottom, wherein the groove is located at an interface between the outer substrate layer and the inner substrate layer, and the interface is perpendicular to the support structure; and A mirror surface, including a reflective layer located at the bottom of the groove and on the sidewall of the groove.

2. The semiconductor device as claimed in claim 1, characterized in that, The groove sidewall includes a tapered groove sidewall.

3. The semiconductor device as claimed in claim 2, characterized in that, The sidewall of the conical groove includes a cone angle of 40° to 50°.

4. The semiconductor device as claimed in claim 1 or 2, characterized in that, The mirror includes a bottom portion of the mirror located at the bottom of the groove and a sidewall portion of the mirror located on the sidewall of the groove.

5. The semiconductor device as claimed in claim 1, characterized in that, The inner substrate layer includes a first side surface and a second side surface, the first side surface including the groove, and the second side surface being relative to and parallel to the first side surface of the inner substrate layer.

6. The semiconductor device as claimed in claim 5, characterized in that, The support structure includes an upper surface with a groove configured to support a first optical fiber such that one end of the first optical fiber faces the second side surface of the inner substrate.

7. The semiconductor device as claimed in claim 5, characterized in that, The first side surface of the inner substrate layer also includes an alignment groove, the alignment groove including an alignment groove bottom and an alignment groove sidewall adjacent to the alignment groove bottom, and the alignment groove is located at the interface between the outer substrate layer and the inner substrate layer.

8. The semiconductor device as claimed in claim 7, characterized in that, Also includes: An alignment mirror includes a reflective layer located at the bottom of the alignment groove and on the sidewall of the alignment groove, wherein the alignment mirror includes a bottom portion of the alignment mirror on the bottom of the alignment groove and a sidewall portion of the alignment mirror on the sidewall of the alignment groove.

9. The semiconductor device as claimed in claim 8, characterized in that, The support structure includes an upper surface with an alignment groove configured to support a second optical fiber such that one end face of the second optical fiber faces the second side surface of the inner substrate and that a core of the second optical fiber is aligned with the bottom of the alignment mirror.

10. A semiconductor device, characterized in that, include: A support structure includes multiple trenches, the multiple trenches being configured to support multiple first optical fibers respectively; A base, located on the supporting structure, the base comprising: One outer basal layer; as well as An inner base layer is attached to the outer base layer and includes a plurality of grooves, each of the plurality of grooves including a groove bottom and a groove sidewall adjacent to the groove bottom, wherein the plurality of grooves are located at an interface between the outer base layer and the inner base layer, and the interface is perpendicular to the support structure. Multiple functional mirrors, including a reflective layer, are located at the bottom of the multiple grooves and on the sidewalls of the grooves, wherein the multiple functional mirrors are configured to reflect a light beam from the multiple first optical fibers in a direction parallel to the interface between the outer substrate and the inner substrate; and A photodiode array comprising a plurality of photodiodes configured to receive the light beam reflected from a plurality of functional mirrors.

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