Optical components

Abstract

This invention provides an optical element comprising a back reflective layer, a cladding layer on the back reflective layer, a grating structure on the cladding layer, and a receiving reflective layer on the grating structure, wherein the receiving reflective layer includes an opening.

Description

Technical Field

[0001] The embodiments of this utility model relate to an optical element. Background Technology

[0002] Electrical transmission and processing is a technology for signal transmission and processing. In recent years, optical transmission and processing has been used in an increasing number of applications, especially for signal transmission in fiber-optic applications. A grating coupler is a component that couples optical signals from an optical fiber to an optical waveguide for use in optical transmission and processing systems. However, existing grating couplers often result in energy loss, which in turn affects the overall system performance. Utility Model Content

[0003] In an embodiment of this invention, the optical element includes: a back reflective layer; a cladding layer on the back reflective layer; a grating structure on the cladding layer; and a receiving reflective layer on the grating structure, wherein the receiving reflective layer includes an opening.

[0004] In an embodiment of this invention, the optical element includes: a back reflective layer; a cladding layer on the back reflective layer; a multilayer grating structure on the cladding layer; and a receiving reflective layer on the multilayer grating structure, wherein the receiving reflective layer includes an opening. Attached Figure Description

[0005] The various aspects of this disclosure can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with industry standard practice, the various features are not drawn to scale. In fact, for clarity of discussion, the dimensions of the various features may be arbitrarily increased or decreased.

[0006] Figure 1 This is a side sectional view showing the intermediaries used in a method for forming a photonic platform according to some embodiments;

[0007] Figure 2 This is a side sectional view illustrating the processing of an intermediary to provide a first optical element according to some embodiments;

[0008] Figure 2A It is a side sectional view showing the formation of a mask to isolate the grating coupler portion of the intermediary according to some embodiments and the removal of the first insulating layer of the intermediary in the grating coupler portion;

[0009] Figure 2B This is a side sectional view showing, according to some embodiments, the formation of a back reflective layer, a first cladding layer, and a single material layer for a single-layer grating structure in the grating coupler portion of the intermediate;

[0010] Figure 2C This is a side sectional view showing a set of gratings formed on the upper surface of a single material layer for a single-layer grating structure according to some embodiments;

[0011] Figure 2D This is a side sectional view showing the formation of a second cladding layer on a single-layer grating structure according to some embodiments;

[0012] Figure 2E This is a side sectional view showing, according to some embodiments, a receiving and reflecting layer is formed on a second cladding layer, wherein the receiving and reflecting layer includes openings for receiving optical signals into at least a single grating layer structure;

[0013] Figure 2F This is a top view of a grating coupler, showing an opening through the receiving reflective layer to a single grating layer structure according to some embodiments;

[0014] Figure 2G It is a side cross-sectional view showing, according to some embodiments, etched trenches in a first cladding layer and deposited a single material layer of a monolayer grating structure, wherein the material filling the trenches provides a second set of gratings extending along a second direction;

[0015] Figure 2H It is a side sectional view showing, according to some embodiments, trenches are etched in a single material layer of a single-layer grating structure to form a first set of trenches extending along a first direction, and a second cladding layer is formed on the single-layer grating structure;

[0016] Figure 2I This is a side sectional view showing, according to some embodiments, a receiving and reflecting layer is formed on a second covering layer, wherein the receiving and reflecting layer includes an opening for receiving optical signals to at least a single-layer grating structure;

[0017] Figure 2J It is a side sectional view showing a first grating layer in which trenches are formed in a first cladding layer and a multilayer grating structure is formed on the first cladding layer, according to some embodiments, wherein material from the first grating layer fills the trenches in the first cladding layer to provide a third multilayer grating;

[0018] Figure 2K It is a side sectional view showing, according to some embodiments, trenches are formed in a first material layer of a multilayer grating structure and a second material layer of the multilayer grating structure is formed on the first material layer, wherein material from the second material layer fills the trenches in the first grating layer to provide a second multilayer grating;

[0019] Figure 2L It is a side sectional view showing trenches formed in the second grating layer of a multilayer grating structure according to some embodiments to form a first multilayer group grating;

[0020] Figure 2M This is a side sectional view showing, according to some embodiments, a receiving and reflecting layer is formed on a second covering layer, wherein the receiving and reflecting layer includes openings for receiving optical signals into at least a multilayer grating structure;

[0021] Figures 3 to 9 This is a side sectional view illustrating the integration of, according to some embodiments, such as Figures 2A to 2M The formation of the photonic platform of the grating coupler described in the paper. Detailed Implementation

[0022] The following disclosure provides numerous different embodiments or examples for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to simplify this disclosure. Of course, these are merely examples and are not intended to be limiting. For example, in the following description, forming a first feature above or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features such that the first and second features are not in direct contact. Additionally, reference numerals and / or letters may be repeated in the various examples of this disclosure. Such repetition is for simplicity and clarity and does not in itself define a relationship between the various embodiments and / or configurations discussed.

[0023] Furthermore, for ease of description, this document uses spatial relative terms such as “below,” “under,” “lower,” “above,” and “above” to describe the relationship between one element or feature and another element or feature as shown in the figures. In addition to the orientation depicted in the figures, the spatial relative terms are intended to cover different orientations of the device or operation in use. The device may be oriented in other ways (rotated 90 degrees or otherwise) and the spatial relative descriptors used herein can be interpreted accordingly.

[0024] In some embodiments, the structures and methods described herein provide an optical structure including a double-layered metallic reflective layer. In some embodiments, the optical structure includes a receiving reflective layer having an opening therethrough for receiving optical signals transmitted from an optical fiber to a grating structure of the optical device. In some embodiments, the double-layered metallic reflective layer of the optical element further includes a back reflective layer located on opposite sides of the grating structure, the grating structure having a receiving reflective layer including an aperture structure.

[0025] The embodiments presented herein are intended to be illustrative and are not intended to limit the embodiments to the precise descriptions discussed. Rather, the embodiments discussed may be incorporated into a wide variety of implementations, and all such implementations are fully intended to be included within the scope of the embodiments.

[0026] Now for reference Figure 1 This shows the initial structure of the optical medium 100. Figure 1In the specific embodiment shown, the optical intermediary 100 is a photonic integrated circuit (PIC) and at this stage includes a first substrate 101, a first insulating layer 103, and a layer of material 105 (not shown separately) for the first active layer 201 of the first optical component 203. Figure 1 In China but Figure 2 (Shown and described). In an embodiment, at the start of the manufacturing process of the optical medium 100, the first substrate 101, the first insulating layer 103, and a layer of material 105 for the first active layer 201 for the first optical component 203 may collectively be part of silicon-on-insulator (SOI). Referring first to the first substrate 101, the first substrate 101 may be a semiconductor material (e.g., silicon or germanium), a dielectric material (e.g., glass), or any other suitable material that allows for structural support of the overlying components.

[0027] The first insulating layer 103 may be a dielectric layer separating the first substrate 101 from the overlying first active layer 201, and in some embodiments, may additionally serve as part of a cladding material surrounding a subsequently fabricated first optical component 203 (discussed further below). In embodiments, the first insulating layer 103 may be silicon oxide, silicon nitride, germanium oxide, germanium nitride, combinations thereof, etc., formed using methods such as implantation (e.g., to form a buried oxide (BOX) layer), or it may be deposited onto the first substrate 101 using deposition methods such as chemical vapor deposition, atomic layer deposition, physical vapor deposition, combinations thereof, etc. However, any suitable materials and fabrication methods may be used.

[0028] The material 105 of the first active layer 201 is initially (before patterning) a conformal layer of material that will be used to begin fabricating the first active layer 201 of the first optical component 203. In embodiments, the material 105 of the first active layer 201 may be a translucent material that can be used as the core material of the desired first optical component 203, such as a semiconductor material, such as silicon, germanium, silicon-germanium, combinations thereof, etc. In other embodiments, the material 105 of the first active layer 201 may be a dielectric material, such as silicon nitride, etc., although in other embodiments, the material 105 of the first active layer 201 may be a III-V material, lithium niobate material, or a polymer. In embodiments where the material 105 of the first active layer 201 is deposited, methods such as epitaxial growth, chemical vapor deposition, atomic layer deposition, physical vapor deposition, combinations thereof, etc., can be used to deposit the material 105 of the first active layer 201. In other embodiments where the first insulating layer 103 is formed using an implantation method, the material 105 of the first active layer 201 may initially be part of the first substrate 101 before the implantation process to form the first insulating layer 103. However, the material 105 of the first active layer 201 may be formed using any suitable material and manufacturing method.

[0029] Figure 2 This illustrates that once the material 105 of the first active layer 201 is ready, the material 105 of the first active layer 201 is used to fabricate the first optical component 203 of the first active layer 201. In embodiments, the first optical component 203 of the first active layer 201 may include components such as optical waveguides (e.g., ridge waveguides, rib waveguides, buried channel waveguides, diffused waveguides, etc.), directional couplers, optical modulators (e.g., Mach-Zehnder silicon photonic switches, microelectromechanical switches, microring resonators, etc.), amplifiers, multiplexers, demultiplexers, photoelectric converters (e.g., PN junctions), electro-optic converters, lasers, combinations thereof, etc. However, any suitable first optical component 203 may be used.

[0030] To begin forming the first active layer 201 of the first optical component 203 from initial material, the material 105 of the first active layer 201 can be patterned to the desired shape of the first active layer 201 of the first optical component 203. In embodiments, the material 105 of the first active layer 201 can be patterned using, for example, one or more photolithographic masks and etching processes. However, any suitable method for patterning the material 105 of the first active layer 201 can be used. For some first optical components 203, the patterning process can be used for all or at least most of the fabrication of forming these first optical components 203.

[0031] In some embodiments, a portion of the intermediary 100 may be processed to provide a grating coupler 204 (such as...). Figure 3(See image). The portion of the intermediate 100 processed to provide the grating coupler 204 is hereinafter referred to as the grating coupler portion 205 of the intermediate 100. In some embodiments, to protect the first optical component 203 during the processing for forming the grating coupler 204, the portion of the intermediate 100 containing the first optical component 203 is covered by a mask structure. In some embodiments, the mask structure is patterned such that the grating coupler portion 205 of the intermediate 100 is exposed. The mask structure protecting the first optical component 203 from the processes used to form the grating coupler 204 can be a hard mask, a photoresist mask, or a combination of a photoresist mask and a hard mask. The mask structure used to isolate the grating coupler portion 205 of the intermediate can be removed after the grating coupler 204 is completed.

[0032] Figure 2A An embodiment is shown in which a first mask 206 is formed to protect the first optical component 203 and expose the grating coupler portion 205 of the intermediary 100. After the first mask 206 is formed, an etching process can be used to remove any portions of the first active layer 105 and the first insulating layer 103 that may be present in the grating coupler portion 205 of the intermediary 100. The etching process used at this stage of the process flow can be anisotropic etching, such as reactive ion etching (RIE). In some embodiments, the etching process for removing the first insulating layer 103 may include etching chemicals that are selective to the first substrate 101. After the first insulating layer 103 is removed, the upper surface of the first substrate 101 may be exposed.

[0033] Figures 2B to 2F This illustration shows an embodiment of a grating coupler portion 205 of a processing medium 100 to form a grating coupler 204 on top of a first substrate 101 including a single-layer grating structure 211. In some embodiments, by Figures 2B to 2F The grating coupler formed by the process flow shown is an optical element, which includes a back reflective layer 260, a first cladding layer 103A on the back reflective layer 260, a single-layer grating structure 211 on the back reflective layer 260, and a receiving reflective layer 265 on the single-layer grating structure 211 (see...). Figure 2E In some embodiments, the receiving reflective layer 265 includes an opening 270 for receiving optical signals to at least a single-layer grating structure 211 (see [link]). Figure 2E ).exist Figures 2B to 2F During the processing of the grating coupler portion 205 depicted, the remainder of the intermediary 100, including the first optical component 203, may be protected by one or more block masks and / or hard masks.

[0034] Figure 2BAn embodiment is shown in which a back reflective layer 260 is formed on the upper surface of a first substrate 101 present in the grating coupler portion 205. The back reflective layer 260 is an element of a double-layer metal reflective layer, which increases the number of reflections of the optical signal received by the optical element. In some embodiments, the back reflective layer 260 allows bottom-reflected optical signals reflected from the back reflective layer to be coupled back into the grating structure via a reflection mechanism. The back reflective layer 260 may also be referred to as a mirror layer, such as a back mirror layer. In some embodiments, the back reflective layer 260 may also be a distributed Bragg reflector.

[0035] In some embodiments, the back reflective layer 260 may be made of a material containing a metallic composition. For example, the back reflective layer 260 may be made of metals such as gold (Au), silver (Ag), copper (Cu), tin (Sn), aluminum (Al), tungsten (W), tantalum (Ta), platinum (Pt), and their alloys. In some embodiments, the formation of the back reflective layer 260 may begin with the deposition of a seed layer. For example, the seed layer may include a copper layer. Depending on the desired material, the seed layer may be deposited using processes such as sputtering, vapor deposition, or plasma-enhanced chemical vapor deposition. The back reflective layer 260 may then be electroplated onto the seed layer. The electroplated metal of the back reflective layer 260 may be deposited over the seed layer using an electroplating process such as electroplating or electroless plating. It should be noted that the methods and compositions of the back reflective layer 260 are provided for illustrative purposes only and are not intended to limit this disclosure to only the materials and methods described above. Other compositions and methods of the back reflective layer 260 are also within the scope of this disclosure, provided that the formed back reflective layer 260 is a light signal reflecting structure. For example, the back reflective layer 260 can be formed using a back-side process at a later point in the process flow (e.g., after the grating structure has been formed).

[0036] Figure 2B A first cladding layer 103A is also shown formed on the back reflective layer 260. The first cladding layer 103A may be composed of an oxide-containing material, such as silicon oxide (SiO2). The first cladding layer 103A may be deposited using a chemical vapor deposition (CVD) process. It should be noted that chemical vapor deposition (CVD) is only one example of a suitable deposition process for forming the first cladding layer 103A. In other examples, the first cladding layer 103A may be formed using deposition processes such as atomic layer deposition (ALD) or physical vapor deposition (PVD). Furthermore, the composition of the first cladding layer 103A is not limited to silicon oxide. For example, in addition to silicon oxide, the first cladding layer 103A may also be composed of silicon nitride, germanium oxide, germanium nitride, and combinations thereof.

[0037] Figure 2BA single material layer 209 forming a single-layer grating structure 211 is also shown. The single material layer 209 can be formed to directly contact the upper surface of the first cladding layer 103A using a single deposition step. In some embodiments, the single material layer 209 of the single-layer grating structure 211 may be made of a semiconductor-containing material, such as a silicon-containing material, for example, silicon (Si). In some embodiments, the single material layer 209 may be made of a dielectric material, such as a nitride-containing material, for example, silicon nitride (Si3N4). In some embodiments, the single material layer 209 may be deposited using a chemical vapor deposition (CVD) process. In one example, the chemical vapor deposition (CVD) process may be plasma-enhanced chemical vapor deposition (PECVD). In other examples, high-density plasma-enhanced chemical vapor deposition (HDPCVD), atomic layer deposition (ALD), or physical vapor deposition (PVD) may be used to deposit the single material layer 209.

[0038] Figure 2C An embodiment is shown in which a set of gratings 212 is formed on the upper surface of a monolithic material layer 209 of a monolayer grating structure 211. In some embodiments, the set of gratings 212 can be formed by forming trenches 210 on the upper surface of the monolithic material layer 209. Forming trenches 210 on the upper surface of the monolithic material layer 209 may include an etching process. For example, the etching process for forming trenches 210 may include forming an etching mask that is patterned to expose portions of the monolithic material layer 209 to be etched to form trenches 210. The portions of the monolithic material layer 209 protected by the etching mask and the portions between each pair of trenches 210 provide a set of gratings 212 after the etching step for forming trenches 210. In some embodiments, the etching process for forming trenches 210 may be anisotropic etching, i.e., directional etching, such as reactive ion etching (RIE). Figure 2C The depicted set of gratings 212 has a height extending in direction D1 toward the subsequently formed receiving and reflecting layer 265 (e.g. Figure 2E (What I saw).

[0039] In some embodiments, the height of a set of gratings 212 can be adjusted to provide coupling with light of different wavelengths. In some examples, the height of a set of gratings 212 can be changed by varying the etching depth of the trench 210. To change the etching depth of the trench 210, one or more etching masks and etching processes can be applied, wherein the etching time is varied to change different etching depths. In another embodiment, the etching process can be accompanied by an ion implantation process, which can vary the etching rate of the material being etched. In other examples, the height of the gratings can be changed by recessing the upper surface of the gratings themselves, which can also be achieved using multiple masks and multiple etching steps.

[0040] Figure 2DA second cladding layer 225 is shown formed on the surface of a single material layer 209 comprising a single-layer grating structure 211 with a set of gratings 212. The second cladding layer 225 may be composed of an oxide-containing material composition, such as silicon oxide (SiO2). The second cladding layer 225 may also be composed of silicon nitride, germanium oxide, germanium nitride, and combinations thereof. The second cladding layer 225 may be deposited using a chemical vapor deposition (CVD) process. It should be noted that chemical vapor deposition (CVD) is only one example of a suitable deposition process for forming the second cladding layer 225. In other examples, the second cladding layer 225 may be formed using deposition processes such as atomic layer deposition (ALD) or physical vapor deposition (PVD).

[0041] Figure 2E A receiving and reflecting layer 265 is shown formed on the second cladding layer 225. In some embodiments, the receiving and reflecting layer 265 includes an opening 270 for receiving an optical signal to at least a single-layer grating structure 211. The receiving and reflecting layer 265 is an element of a double-layer metallic reflective layer, which can increase the number of reflections of the optical signal received by the optical element. An optical element including a double-layer metallic reflective layer and a grating structure provides a grating coupler capable of effectively confining and focusing the optical signal. For example, the opening 270 (also referred to as an aperture structure) through the receiving and reflecting layer 265 can effectively focus the optical signal at the entrance of the grating structure portion of the grating coupler, thereby improving the coupling and collection efficiency of the optical signal. Additionally, in some embodiments, by using a mechanism of multiple reflections, the bottom-reflected optical signal reflected by the back-side reflective layer 260 can be guided back and coupled into the grating coupler, further enhancing the coupling efficiency. The receiving and reflecting layer 265 can also be referred to as a mirror layer, such as a receiving mirror layer. The receiving and reflecting layer 265 can be a distributed Bragg reflector.

[0042] In some embodiments, the receiving and reflecting layer 265 may be made of a material containing a metallic composition. For example, the receiving and reflecting layer 265 may be made of metals such as gold (Au), silver (Ag), copper (Cu), tin (Sn), aluminum (Al), tungsten (W), tantalum (Ta), platinum (Pt), and their alloys. In some embodiments, the formation of the receiving and reflecting layer 265 may begin with the deposition of a seed layer. For example, the seed layer may include a copper layer. Depending on the desired material, the seed layer may be deposited using processes such as sputtering, vapor deposition, or plasma-enhanced chemical vapor deposition. The receiving and reflecting layer 265 may then be plated onto the seed layer. The electroplated metal of the receiving and reflecting layer 265 may be deposited over the seed layer using a plating process such as electroplating or electroless plating. It should be noted that the method compositions and components of the receiving and reflecting layer 265 are provided for illustrative purposes only and are not intended to limit this disclosure to the materials and methods described above. Other compositions and methods of the receiving and reflecting layer 265 are also within the scope of this disclosure, provided that the formed receiving and reflecting layer 265 is a light signal reflecting structure.

[0043] After forming the material layer of the receiving and reflecting layer 265, an opening 270 may be formed through the receiving and reflecting layer 265 to receive optical signals, such as optical signals transmitted from an optical fiber to the single-layer grating structure 211. In some embodiments, forming the opening 270 may include photolithography and etching processes.

[0044] In some embodiments, to protect portions of the metal layer receiving the reflective layer 265 during the etching process for forming the opening 270, a photoresist layer may be deposited and patterned to provide a mask structure that exposes the portions of the metal layer in which the opening 270 is formed. In some embodiments, the photoresist mask may be used in conjunction with a hard mask, which may be composed of a dielectric material (e.g., oxides and / or nitrides).

[0045] After forming the etch mask, an etching process can be used to remove exposed portions of the metal layer to provide an opening 270 through the receiving reflective layer 265. The etching process used at this stage of the process flow can be anisotropic etching, such as reactive ion etching (RIE). In some embodiments, the etching process for forming the opening 270 through the receiving reflective layer 265 may include etch chemicals selectively applied to the second overlay layer 225. After forming the opening 270, the etch mask can be removed. For example, a chemical stripping method can be used to remove the etch mask.

[0046] In some embodiments, an opening 270 through the receiving reflective layer 265 is positioned on a first side of the grating coupler 204 for receiving light from the optical fiber 905 (see [link]). Figure 9 The optical signal. In some embodiments, the first side of the grating structure 204 where the opening 270 is located is relative to the second side of the grating structure 204, which may include a waveguide interface portion.

[0047] Figure 2F This is a top view further showing the opening 270 through the receiving reflective layer 265. In one example, the opening 270 may have a width W1 ranging from 1 micrometer to 50 micrometers, and a length L1 ranging from 1 micrometer to 50 micrometers. Figure 2F The single-layer grating structure 211 also includes a grating having a tapered width that decreases toward the waveguide joining portion 215 of the grating coupler 204. Figure 2F It is also shown that in some embodiments, the geometry of the gratings of a set of gratings 212 in a single-layer grating structure 211 may include curvature.

[0048] Now back Figure 2EFurthermore, by using bidirectional reflectors, such as a back reflector 260 and a receiving reflector 265, the received optical signal 271 received from the optical fiber can be effectively coupled to the single-layer grating structure 211 of the grating 204 to enhance the coupling and collection efficiency of the optical signal. First, the received optical signal 271 emitted from the optical fiber enters the single-layer grating structure 211 of the grating coupler 204 through an opening 270 in the receiving reflector 265. A portion of the optical signal 271 is initially coupled by the single-layer grating structure 211. However, a portion of the optical signal 271 is not coupled to the single-layer grating structure 211 and passes through the single-layer grating structure 211 towards the back reflector 260. The back reflector 260 can reflect the uncoupled portion of the optical signal for the first time, reflecting the uncoupled portion of the optical signal as a first reflected optical signal 272 towards the receiving reflector 265. The first reflected optical signal 272 passes through the single-layer grating structure 211, where another portion of the optical signal is coupled to the single-layer grating structure 211. Another uncoupled portion of the optical signal can pass through the single-layer grating structure 211 towards the receiving reflective layer 265. The receiving reflective layer 265 can increase the number of optical signal reflections in the grating coupler 204 by reflecting the optical signal back to the back reflective layer 260. For example, the uncoupled signal from the first reflected optical signal 272 can be reflected from the lower surface of the receiving reflective layer 265 as a second reflected optical signal 273 having a direction toward the back reflective layer 260. In some embodiments, the dual-layer metallic reflection characteristics provided by the combination of the receiving reflective layer 265 and the back reflective layer 260 can effectively confine and concentrate the optical signal as a coupled optical signal 274 traveling toward the waveguide interface portion 15 of the grating coupler 204, further enhancing the coupling and collection efficiency of the optical element.

[0049] Figures 2G to 2I An embodiment of a grating coupler 204 is shown. The grating coupler 204 includes a single-layer grating structure 211 having bidirectional gratings, for example, a first set of gratings 212 having a first direction D1 and a second set of gratings 214 having a second direction D2, wherein the first direction D1 and the second direction D2 are opposite (see...). Figure 2I The first set of gratings 212 is formed on the upper surface of the monolithic material layer 209 of the monolithic grating structure 211. In some embodiments, the second set of gratings 214 exists on the opposite lower surface of the monolithic material layer 209 of the monolithic grating structure 211. The first set of gratings 212 on the upper surface of the monolithic material layer 209 of the monolithic grating structure 211 can be similar to... Figures 2C to 2E The depicted set of gratings 212. In Figures 2G to 2I During the processing of the grating coupler portion 205 depicted, the remaining portion of the intermediary 100, including the first optical component 203, may be protected by one or more block masks and / or hard masks.

[0050] Figure 2GAn initial structure that can be used in a process flow is shown, the process flow providing a bidirectional reflector (e.g., a receiving reflective layer 265 and a back reflective layer 260) and a single-layer grating structure 211 including a bidirectional grating. Figure 2G The depicted initial structure includes a first substrate 101, a back reflective layer 260, and a first cladding layer 103A. (See above for reference.) Figures 2 to 2F Each of these components is described. The above description of these components applies to... Figure 2G Elements that have the same reference numerals in the figures.

[0051] Figure 2G Also shown is the etching of trench 216 in the first cladding layer 103A and the deposition of a monomaterial layer 209 of a monolayer grating structure 211. In this embodiment, the material filling the trench 216 provides a second set of gratings 214 extending along a second direction D2. In some embodiments, forming the trench 216 in the first cladding layer 103A includes forming an etching mask (not shown). The etching mask protects a portion of the first cladding layer 103A while forming the trench 216. In some embodiments, the etching process used to form the trench 216 may be directional etching, such as reactive ion etching (RIE). The trench 216 formed in the first cladding layer 103A is then filled with material from the subsequently formed monomaterial layer 209 of the monolayer grating structure 211. In some embodiments, filling the trench 216 with the material of the monomaterial layer 209 provides a second set of gratings 214. In some embodiments, the trench 216 can be patterned with a geometry having curvature and a tapered width, such that when the material filling the monolithic layer 209 is used, a second set of gratings 214 with a geometry having curvature and a tapered width toward the waveguide junction 215 can be provided, which, together with... Figure 2F The geometry of the depicted grating 212 is similar.

[0052] Figure 2G An embodiment is also shown in which a single material layer 209 is formed on the first covering layer 103A after the trench 216 is formed. Figures 2G to 2I In the illustrated embodiment, the monolithic material layer 209 of the monolayer grating structure 211 is provided by a material layer deposited using a single deposition step. In some embodiments, the monolithic material layer 209 may be composed of a semiconductor-containing material, such as a silicon-containing material, for example, silicon (Si). In some embodiments, the monolithic material layer 209 may be composed of a dielectric material, such as a nitride-containing material, for example, silicon nitride (Si3N4).

[0053] In some embodiments, a chemical vapor deposition (CVD) process can be used to deposit a monomaterial layer 209, wherein deposition parameters are selected to fill the trench 216 with at least the material of the monomaterial layer 209. In one example, the chemical vapor deposition (CVD) process can be plasma-enhanced chemical vapor deposition (PECVD). In other examples, high-density plasma-enhanced chemical vapor deposition (HDPCVD), atomic layer deposition (ALD), or physical vapor deposition (PVD) can be used to deposit the monomaterial layer 209.

[0054] Figure 2H An embodiment is shown in which trenches 210 are etched in a single material layer 209 of a single-layer grating structure 211 to form a first set of gratings 212 extending along a first direction D1. Figure 2H The ditch 210 formed as shown in the figure and Figure 2C The ditch 210 shown is similar. Therefore, the above references Figure 2C The provided description of the formation of ditch 210 is suitable for describing within a defined scope. Figure 2H Trench 210 is formed in a single material layer 209 of the first set of gratings 212 shown. In summary, in some embodiments, forming trench 210 may include photolithography and etching methods.

[0055] In some embodiments, the depth of trench 210 can be adjusted to provide different grating heights within the first set of gratings for coupling with light of different wavelengths. In some examples, the height of the first set of gratings 212 can be changed by varying the etching depth of trench 210. To change the etching depth of trench 210, one or more etching masks and etching processes can be applied, wherein the etching time is varied to change different etching depths. In another embodiment, the etching process can be accompanied by ion implantation, which can change the etching rate of the material being etched. In other examples, the height of the grating can be changed by recessing the upper surface of the grating itself, which can also be achieved using multiple masks and etching steps.

[0056] Figure 2H A second cladding layer 225 is also shown formed on top of the single-layer grating structure 211. The second cladding layer 225 can be composed of an oxide-containing material, such as silicon oxide (SiO2). The second cladding layer 225 can also be composed of silicon nitride, germanium oxide, germanium nitride, and combinations thereof. The second cladding layer 225 can be deposited using a chemical vapor deposition (CVD) process. It should be noted that chemical vapor deposition (CVD) is only one example of a suitable deposition process for forming the second cladding layer 225. In other examples, the second cladding layer 225 can be formed using deposition processes such as atomic layer deposition (ALD) or physical vapor deposition (PVD).

[0057] Figure 2IAn embodiment is shown in which a receiving and reflecting layer 265 is formed on a second cladding layer 225. In some embodiments, the receiving and reflecting layer 265 includes an opening 270 for receiving an optical signal into at least a single-layer grating structure 211, the single-layer grating structure 211 including bidirectional gratings, for example, a first set of gratings 212 extending along a first direction D1 and a second set of gratings 214 extending along a second direction D2. The receiving and reflecting layer 265 may also be referred to as a mirror layer, such as a receiving mirror layer. The receiving and reflecting layer 265 may also be referred to as a distributed Bragg reflector.

[0058] Figure 2I The receiving and reflecting layer 265 depicted in the image is similar to... Figure 2E and Figure 2I The receiving and reflecting layer 265 is depicted in the diagram. Therefore, Figure 2E and Figure 2I The above description of the receiving and reflecting layer 265 depicted herein is suitable for describing Figure 2M At least one embodiment of the receiving reflective layer 265 depicted herein.

[0059] In some embodiments, the receiving and reflecting layer 265 may be made of a material containing a metallic composition. For example, the receiving and reflecting layer 265 may be made of metals such as gold (Au), silver (Ag), copper (Cu), tin (Sn), aluminum (Al), tungsten (W), tantalum (Ta), platinum (Pt), and their alloys.

[0060] In some embodiments, an opening 270 may be formed through the receiving reflective layer 265 to receive optical signals, such as optical signals transmitted from an optical fiber to the single-layer grating structure 211. In some embodiments, forming the opening 270 may include photolithography and etching processes.

[0061] In some embodiments, an opening 270 through the receiving reflective layer 265 is positioned on a first side of the grating coupler 204 for receiving signals from the optical fiber 905 (see [link]). Figure 9 The optical signal. In some embodiments, the first side of the grating structure 204 where the opening 270 is located is relative to the second side of the grating structure 204, wherein the second side of the grating structure 204 may include the waveguide interface portion of the grating coupler.

[0062] refer to Figure 2IIn addition to the advantages provided by bidirectional reflectors (e.g., back reflective layer 260 and receiving reflective layer 265), the bidirectional grating allows for multiple reflections of the optical signal as it passes through the grating coupler 204 toward the waveguide junction 215, enabling the coupling of light of different wavelengths. For example, for coupling of different wavelengths, the heights of the gratings in the first set of gratings 212 and the second set of gratings 214 can be adjusted to provide a low-loss design. In one example, each of the first set of gratings 212 and the second set of gratings 214 may have gratings of different sizes to provide that the first set of gratings 212 and the second set of gratings 214 are optimized for coupling with different wavelengths of light in a low-loss design.

[0063] In other examples, the distance between adjacent gratings can be increased or decreased for coupling light of different wavelengths. For example, the distance between adjacent gratings in the second set of gratings 214 can be greater than the distance between adjacent gratings in the first set of gratings 212. In some examples, this allows the second set of gratings 214 to be suitable for coupling light with a wider bandwidth of wavelength than the light for which the first set of gratings 212 is configured for coupling.

[0064] Figures 2J to 2M An embodiment of a grating coupler 204 is shown, which includes a bidirectional reflector (e.g., a receiving reflective layer 265 and a back reflective layer 260) and a grating layer that may be a multilayer structure. In some embodiments, the multilayer structure provides a bidirectional grating, for example, a first multilayer group grating 212 having a first direction D1 and a second multilayer group grating 214 having a second direction D2, wherein the first direction D1 and the second direction D2 are opposite to each other. In yet another embodiment, the multilayer structure of the grating layer can provide at least three separate grating groups, such as a first multilayer group grating 240, a second multilayer group grating 235, and a third multilayer group grating 230. Figures 2J to 2M During the processing of the grating coupler portion 205 shown, the remaining portion of the intermediary 100, including the first optical component 203, may be protected by one or more block masks and / or hard masks.

[0065] Figure 2J The diagram illustrates an initial structure that can be used in a process flow, providing a bidirectional reflector (e.g., a receiving reflective layer 265 and a back reflective layer 260) and a multilayer grating structure 280 including a bidirectional grating (e.g., ...). Figure 2K (As shown). Figure 2J The depicted initial structure includes a first substrate 101, a back reflective layer 260, and a first cladding layer 103A. Each of these components has been referenced above. Figures 2 to 2F The above description of these components applies to... Figure 2J Elements that have the same reference numerals in the figures.

[0066] Figure 2J It also shows that the upper surface of the first cladding layer 103A has been etched to provide multiple trenches 216. Figure 2J The ditch 216 depicted is similar Figure 2G The grooves 216 present in the upper surface of the first covering layer 103A as depicted. Therefore, the above... Figure 2G The description of ditch 216 shown is suitable for describing the formation Figure 2J At least one embodiment of the groove 216 in the upper surface of the first covering layer 103A shown.

[0067] Figure 2J Also shown is a first grating layer 221 forming a multilayer grating structure 280 on the first cladding layer 103A. In some embodiments, the first grating layer 221 may be made of a semiconductor material, such as silicon (Si). In some embodiments, the first grating layer 221 may be made of a nitride material, such as silicon nitride (Si3N4). Additionally, the material of the first grating layer 221 fills the trenches 216 in the upper surface of the first cladding layer 103A. The material of the first grating layer 221 can be deposited using a chemical vapor deposition (CVD) process, wherein deposition parameters are selected to at least fill the trenches 216. In one example, the chemical vapor deposition (CVD) process may be plasma-enhanced chemical vapor deposition (PECVD). The material of the first grating layer 221 filling the trenches 216 provides a third multilayer grating 230.

[0068] Figure 2K The diagram illustrates the formation of a trench 234 in a first grating layer 221 of a multilayer grating structure 280 and a second grating layer 223 of the multilayer grating structure 280 formed on the first grating layer 231. In some embodiments, material in the second grating layer 223 fills the trench 234 in the first grating layer 221 to provide a second multilayer grating 235. Therefore, in some embodiments, because the geometry of the trench 234 determines the geometry of the grating, the trench 234 can be etched to have curvature and a tapered width, the tapered width having a maximum width to a minimum width, the maximum width being at the optical signal entry point of the plurality of gratings and the minimum width being at the waveguide interface portion of the plurality of gratings. The trench 234 can be formed using photolithography (e.g., photoresist etch mask formation) and etching processes (e.g., reactive ion etching (RIE)).

[0069] Figure 2KAn embodiment is also shown in which a second grating layer 223 is deposited on the first grating layer 221 to form a second multilayer grating 235. In some embodiments, the second grating layer 223 may be made of a semiconductor-containing material, such as a silicon-containing material, for example, silicon. In some embodiments, the second grating layer 223 may be made of a dielectric material, such as a nitride-containing material, for example, silicon nitride. The second grating layer 223 may be deposited using a chemical vapor deposition (CVD) process, wherein deposition parameters are selected to at least fill the trench 234. In one example, the chemical vapor deposition (CVD) process may be plasma-enhanced chemical vapor deposition (PECVD).

[0070] The material of the second grating layer 223 fills the trench 234, thereby providing a second multilayer grating 235. The second multilayer grating 235 exists at the interface between the first grating layer 221 and the second grating layer 223. The second multilayer grating 235 has a height that extends along a second direction D2 into the trench 234 formed in the first grating layer 221.

[0071] Figure 2L The diagram illustrates trenches 239 formed in a second grating layer 223 of a multilayer grating structure 280 to form a first multilayer group grating 240. In some embodiments, forming the first multilayer group grating 240 in the upper surface of the second grating layer 223 may include forming an etching mask (not shown) patterned to expose portions of the second grating layer 233 to be etched to form the trenches 239. The etching mask may be a photoresist mask formed using photolithography. The trenches 239 may be formed using anisotropic etching processes, such as reactive ion etching (RIE). The portions of the second grating layer 223 present between each group of trenches 239 provide the grating 240 of the first multilayer group grating. After the etching process, the etching mask may be removed using a chemical stripping process.

[0072] The first multi-layer grating 240 can have the same... Figure 2F The grating geometry depicted in the top view is similar to a geometry with curvature and tapered width. The first multilayer grating 240 exists in the upper surface of the second grating layer 223 and has a height extending along the first direction D1.

[0073] A first direction D1 of the first multilayer grating 240 is relative to a second direction D2 of the second multilayer grating 235 and the third multilayer grating 230. In some embodiments, the first direction D1 of the first multilayer grating 240 relative to the second direction D2 of the second multilayer grating 235 and the third multilayer grating 230 provides a bidirectional multilayer grating coupler structure 280. The first multilayer grating 240, present in the upper surface of the second grating layer 223, is vertically offset from the second multilayer grating 235 present at the interface between the first grating layer 221 and the second grating layer 223. The third multilayer grating 230 and the second multilayer grating 235 are also vertically offset from the first multilayer grating 240 present in the lower surface of the first grating layer 221. In some embodiments, the vertical offset of the third multilayer grating 230 from the second multilayer grating 235 and the first multilayer grating 240 can improve the coupling efficiency of the grating coupler 204. For example, by offsetting the direction and center position of the gratings, the coupling efficiency can be improved while reducing insertion loss and reflection loss.

[0074] In some other embodiments, for coupling light of different wavelengths, the distance between adjacent gratings in the first multilayer grating 240, the second multilayer grating 235, and the third multilayer grating 230 can be selected (e.g., increased and / or decreased). For example, the distance between adjacent gratings in the third multilayer grating 230 can be greater than the distance between adjacent gratings in the first multilayer grating 240 and the second multilayer grating 235 to provide that the third multilayer grating 230 is configured for coupling broadband light. For example, the broadband design of the third multilayer grating 230 can couple light with a wider wavelength than the light coupled to the first multilayer grating 240 and the second multilayer grating 235.

[0075] Figure 2M The diagram shows a second cladding layer 225 formed on top of a multilayer grating structure 280. The second cladding layer 225 can be composed of an oxide-containing material, such as silicon oxide (SiO2). The second cladding layer 225 can also be composed of silicon nitride, germanium oxide, germanium nitride, and combinations thereof. The second cladding layer 225 can be deposited using a chemical vapor deposition (CVD) process. It should be noted that chemical vapor deposition (CVD) is only one example of a suitable deposition process for forming the second cladding layer 225. In other examples, the second cladding layer 225 can be formed using deposition processes such as atomic layer deposition (ALD) or physical vapor deposition (PVD).

[0076] Figure 2M It is also shown that a receiving and reflecting layer 265 is formed on the second covering layer 225, wherein the receiving and reflecting layer 265 includes an opening 270 for receiving optical signals to at least a multilayer grating structure 280. Figure 2M The receiving and reflecting layer 265 depicted in the image is similar to... Figure 2E and Figure 2I The receiving and reflecting layer 265 is depicted in the diagram. Therefore, Figure 2E and Figure 2I The above description of the receiving and reflecting layer 265 depicted herein is suitable for describing Figure 2M At least one embodiment of the receiving and reflecting layer 265 depicted herein. In some embodiments, the receiving and reflecting layer 265 includes an opening 270 for receiving optical signals to at least a multilayer grating structure 280. Furthermore, in some embodiments, the receiving and reflecting layer 265 may be a distributed Bragg reflector.

[0077] In some embodiments, the receiving and reflecting layer 265 may be made of a material containing a metallic composition. For example, the receiving and reflecting layer 265 may be made of metals such as gold (Au), silver (Ag), copper (Cu), tin (Sn), aluminum (Al), tungsten (W), tantalum (Ta), platinum (Pt), and their alloys.

[0078] In some embodiments, the opening 270 may be formed through the receiving and reflecting layer 265 to receive optical signals, such as optical signals transmitted from an optical fiber, into the multilayer grating structure 280. In some embodiments, forming the opening 270 may include photolithography and etching processes.

[0079] In some embodiments, an opening 270 through the receiving reflective layer 265 is positioned on a first side of the grating coupler 204 for receiving signals from the optical fiber 905 (see [link]). Figure 9 The optical signal. In some embodiments, the first side where the opening 270 is located in the grating structure 204 is relative to the second side of the grating structure 204, wherein the second side of the grating coupler 204 may include the waveguide interface portion of the grating coupler 204.

[0080] Figure 2MAn embodiment of a bidirectional reflector (e.g., a back reflector layer 260 and a receiving reflector layer 265) coupled to a bidirectional multilayer grating structure 280 is shown, which can effectively enhance the coupling efficiency of the grating coupler 204. In some embodiments, a received optical signal 271 received from an optical fiber can be effectively coupled to the multilayer grating structure 280 of the grating coupler 204 to enhance the coupling and collection efficiency of the optical signal. First, the received optical signal beam 271 emitted from the optical fiber enters the multilayer grating structure 280 of the grating coupler 204 through an opening 270 in the receiving reflector layer 265. A portion of the optical signal beam 271 is coupled to the multilayer grating structure 280, and another portion of the optical signal beam 271 passes through the multilayer grating structure 280. The back reflector layer 260 can reflect the optical signal for the first time and reflect the optical signal as a first reflected optical signal 272 towards the receiving reflector layer 265. The first reflected optical signal 272 passes through the multilayer grating structure 280, wherein a portion of the first reflected optical signal 272 is coupled to the multilayer grating structure 280. A portion of the first reflected optical signal 272 is not coupled to the multilayer grating structure 280 and extends toward the receiving reflective layer 265. The receiving reflective layer 265 can increase the number of optical signal reflections in the grating coupler 204 by reflecting the optical signal back to the back reflective layer 260. For example, the optical signal in the first reflected optical signal 272 that is not coupled to the multilayer grating structure 280 can be reflected from the lower surface of the receiving reflective layer 265 as a second reflected optical signal 273 having a direction toward the back reflective layer 260. In some embodiments, the double-layer metallic reflection characteristics provided by the combination of the receiving reflective layer 265 and the back reflective layer 260 can effectively confine and concentrate the optical signal as a coupled optical signal 274 traveling toward the waveguide interface portion of the grating coupler 204, further enhancing the coupling and collection efficiency of the optical element. The layers of the grating (e.g., the third multilayer grating 230, the second multilayer grating 235, and the first multilayer grating 240) can also effectively couple reflected optical signals from multiple reflections into the waveguide, significantly improving coupling efficiency. Furthermore, designing broadband and high-coupling-efficiency gratings and combining them with mirrors can increase bandwidth and coupling efficiency. A dual design can significantly enhance both broadband and high-coupling-efficiency effects.

[0081] Figures 3 to 9 The integration is shown in the reference above. Figures 2A to 2M The optical package of the described grating coupler 204 is formed. Figures 2A to 2M Each embodiment depicted can be integrated into the reference. Figures 3 to 9 In the described optical package. For simplicity, Figures 2A to 2M Different embodiments of the grating coupler described herein can be derived from Figures 3 to 9The structure marked with reference numeral "204" is depicted together. In some embodiments, any mask structure, such as a hard mask and / or photoresist mask, used to isolate the intermediate 100 may be removed during the formation of the grating coupler 204 prior to the process of integrating the grating coupler 204 into the optical package.

[0082] Figure 3 As shown, for components utilizing further manufacturing processes, such as Mach-Zehnder silicon photonic switches employing resistance heating elements, additional processing can be performed before or after patterning the material of the first active layer 201 to form the first optical component and / or before or after forming the grating coupler 204. For example, injection processes, additional deposition and patterning processes for different materials (e.g., resistance heating elements, III-V materials for converters), combinations of all these processes, etc., can be used to facilitate the further fabrication of various desired first optical components 203. In specific embodiments, and as... Figure 3 As specifically illustrated, in some embodiments, epitaxial deposition of a semiconductor material 301, such as germanium (e.g., for electro / optical signal modulation and conversion), can be performed on patterned portions of the material 105 of the first active layer 201. In such embodiments, the semiconductor material 301 can be epitaxially grown to aid in the fabrication of, for example, a photodiode for a photoelectric converter. All such fabrication processes and all suitable first optical components 203 can be fabricated, and all such combinations are fully intended to be included within the scope of the embodiments.

[0083] Figure 4 As shown, once the grating coupler 204 and the first optical component 203 are formed, a second insulating layer 401 can be deposited to cover the grating coupler 204 and the first optical component 203. The second insulating layer 401 can provide additional cladding material. In an embodiment, the second insulating layer 401 can be a dielectric layer that separates the various components of the first active layer 201 from each other and from the structure above, and can also serve as an additional portion of the cladding material surrounding the first optical component 203 and the grating coupler 204. In an embodiment, the second insulating layer 401 can be silicon oxide, silicon nitride, germanium oxide, germanium nitride, or combinations thereof, formed using deposition methods such as chemical vapor deposition, atomic layer deposition, physical vapor deposition, or combinations thereof. Once the material of the second insulating layer 401 has been deposited, a process such as chemical mechanical polishing can be used to planarize the material so that the top surface of the second insulating layer 401 (in embodiments where the second insulating layer 401 is intended to completely cover the first optical component 203 and the grating coupler 204) is planarized, or the top surfaces of both the first optical component 203 and the grating coupler 204 are planarized with the second insulating layer 401. However, any suitable material and manufacturing method can be used.

[0084] Figure 5 This illustrates that once the first optical component 203 and the grating coupler 204 are fabricated and the second insulating layer 401 is formed, a first metallization layer 501 is formed to electrically connect the grating coupler 204 and the first active layer 201 of the first optical component 203 to the control circuit, to each other, and to subsequently attached elements. Figure 5 Not shown in the image, but referenced below. Figure 6 (Further shown and described). In an embodiment, the first metallization layer 501 is formed of alternating layers of dielectric and conductive materials and can be formed by any suitable process (e.g., deposition, damascene, dual damascene, etc.). In a specific embodiment, multiple metallization layers may be present for interconnecting the various first optical components 203 and the grating coupler 204, but the exact number of first metallization layers 501 depends on the design of the optical medium 100.

[0085] Additionally, during the fabrication of the first metallization layer 501, one or more second optical components 503 may be formed as part of the first metallization layer 501. In some embodiments, the second optical components 503 of the first metallization layer 501 may include components such as couplers (e.g., edge couplers, grating couplers, etc.) for connection to external signals, optical waveguides (e.g., ridge waveguides, rib waveguides, buried channel waveguides, diffused waveguides, etc.), optical modulators (e.g., Mach-Zehnder silicon photonic switches, microelectromechanical switches, microring resonators, etc.), amplifiers, multiplexers, demultiplexers, photoelectric converters (e.g., PN junctions), electro-optic converters, lasers, combinations thereof, etc. However, any suitable optical element may be used for one or more second optical components 503. In embodiments, one or more second optical components 503 may be formed by initially depositing material for one or more second optical components 503. In an embodiment, the material of one or more second optical components 503 may be a dielectric material, such as silicon nitride, silicon oxide, or combinations thereof, or a semiconductor material, such as silicon, deposited using deposition methods such as chemical vapor deposition, atomic layer deposition, physical vapor deposition, or combinations thereof. However, any suitable material and any suitable deposition method may be used.

[0086] Once material for one or more second optical elements 503 is deposited or formed, the material can be patterned into the desired shape of the one or more second optical elements 503. In embodiments, the material of one or more second optical elements 503 can be patterned using, for example, one or more photolithographic masks and etching processes. However, any suitable method for patterning the material of one or more second optical elements 503 can be used.

[0087] For some of the one or more second optical elements 503, such as waveguides or edge couplers, the patterning process can be used to fabricate all or at least most of these components. Additionally, for those components utilizing further fabrication processes, such as Mach-Zehnder silicon photonic switches utilizing resistance heating elements, additional processing can be performed before or after patterning the material of the one or more second optical elements 503. For example, injection processes, additional deposition and patterning processes for different materials, combinations of all these processes, etc., can be used to facilitate the further fabrication of various desired one or more second optical elements 503. All such fabrication processes and all suitable one or more second optical elements 503 can be fabricated, and all such combinations are fully intended to be included within the scope of the embodiments.

[0088] Once one or more second optical components 503 of the first metallization layer 501 have been fabricated, a first bonding layer 505 is formed over the first metallization layer 501. In embodiments, the first bonding layer 505 can be used for dielectric-to-dielectric and metal-to-metal bonding. According to some embodiments, the first bonding layer 505 is formed of a first dielectric material 509 such as silicon oxide, silicon nitride, etc. The first dielectric material 509 can be deposited using any suitable method, such as CVD, high-density plasma chemical vapor deposition (HDPCVD), PVD, atomic layer deposition (ALD), etc. However, any suitable material and deposition process can be utilized.

[0089] Once the first dielectric material 509 is formed, a first opening is formed in the first dielectric material 509 to expose the conductive portion of the underlying layer, preparing for the formation of a first bonding pad 507 within the first bonding layer 505. Once the first opening is formed within the first dielectric material 509, it can be filled with a seed layer and electroplated metal to form the first bonding pad 507 within the first dielectric material 509. The seed layer can cover the top surface of the first dielectric material 509, the exposed conductive portion of the underlying layer, and the sidewalls of the opening and the second opening. The seed layer may include a copper layer. Depending on the desired material, the seed layer can be deposited using processes such as sputtering, evaporation, or plasma-enhanced chemical vapor deposition (PECVD). Electroplated metal can be deposited on the seed layer using a plating process such as electroplating or electroless plating. The electroplated metal may include copper, copper alloys, etc. The electroplated metal may be a filler material. A barrier layer (not shown separately) can cover the top surface of the first dielectric material 509 and the sidewalls of the opening and the second opening prior to the seed layer. The barrier layer may include titanium, titanium nitride, tantalum, tantalum nitride, etc.

[0090] After filling the first opening, a planarization process such as CMP is performed to remove excess portions of the seed layer and electroplated metal, thereby forming a first bonding pad 507 within the first bonding layer 505. In some embodiments, bonding pad vias (not shown separately) may also be used to connect the first bonding pad 507 to an underlying conductive portion, and to connect the first bonding pad 507 to the first metallization layer 501 via the underlying conductive portion.

[0091] Additionally, the first bonding layer 505 may also include one or more third optical components 511 incorporated within the first bonding layer 505. In such embodiments, prior to the deposition of the first dielectric material 509, one or more third optical components 511 may be fabricated using methods and materials similar to those used for one or more second optical components 503 (as described above), for example, by waveguides and other structures formed at least partially by deposition and patterning processes. However, any suitable structure, material, and manufacturing method may be utilized.

[0092] Figure 6 The diagram illustrates a first bonding layer 505 bonding a first semiconductor element 601 to an optical medium 100. In some embodiments, the first semiconductor element 601 is an electronic integrated circuit (EIC, e.g., an element without optical components) and may have a semiconductor substrate 603, an active element 605, an overlying interconnect structure 607, a second bonding layer 609, and an associated third bonding pad 611. In embodiments, the semiconductor substrate 603 may be similar to the first substrate 101 (e.g., a semiconductor material, such as silicon or silicon-germanium), the active element 605 may be a transistor, capacitor, resistor, etc., formed over the semiconductor substrate 603, the interconnect structure 607 may be similar to the first metallization layer 501 (without optical components), the second bonding layer 609 may be similar to the first bonding layer 505, and the third bonding pad 611 may be similar to the first bonding pad 507. However, any suitable element may be used.

[0093] In some embodiments, the first semiconductor element 601 may be configured to work in conjunction with the optical medium 100 to achieve a desired function. In some embodiments, the first semiconductor element 601 may be a high-bandwidth memory (HBM) module, xPU, logic die, 3DIC die, CPU, GPU, SoC die, MEMS die, or a combination thereof. Any suitable element with any appropriate function may be used, and all such elements are fully intended to be included within the scope of the embodiments.

[0094] In embodiments, the first semiconductor element 601 and the first bonding layer 505 can be bonded using dielectric-to-dielectric and metal-to-metal bonding processes. In specific embodiments using dielectric-to-dielectric and metal-to-metal bonding processes, the process can be initiated by activating the surfaces of the second bonding layer 609 and the first bonding layer 505. Activating the top surfaces of the first bonding layer 505 and the second bonding layer 609 can include, for example, dry processing, wet processing, plasma processing, exposure to inert gas plasma, exposure to H2, exposure to N2, exposure to O2, or combinations thereof. In embodiments using wet processing, for example, RCA cleaning can be used. In another embodiment, the activation process can include other types of processing. The activation process facilitates the bonding of the first bonding layer 505 and the second bonding layer 609.

[0095] Following the activation process, the optical medium 100 and the first semiconductor element 601 can be cleaned using, for example, chemical rinsing. The first semiconductor element 601 is then aligned and positioned to make physical contact with the optical medium 100. The optical medium 100 and the first semiconductor element 601 are subjected to heat treatment and contact pressure to bond them. For example, the optical medium 100 and the first semiconductor element 601 can be subjected to pressures of approximately 200 kPa or less and temperatures between approximately 25°C and approximately 250°C to fuse them together. The optical medium 100 and the first semiconductor element 601 can then be subjected to temperatures at or above the eutectic point of the materials of the first bonding pad 507 and the third bonding pad 611, for example, between approximately 150°C and approximately 650°C, to melt the metal. In this way, the optical medium 100 and the first semiconductor element 601 form a dielectric-to-dielectric and metal-to-metal bonding device. In some embodiments, the bonded grains are subsequently baked, annealed, pressed, or otherwise treated to strengthen or finalize the bond.

[0096] Furthermore, while specific processes for initiating and enhancing the bond have been described, these descriptions are illustrative and not intended to limit the embodiments. Instead, any suitable combination or combination of processes, such as baking, annealing, and pressing, can be utilized. All such processes are fully included within the scope of the embodiments.

[0097] Figure 6 It is also shown that once the first semiconductor element 601 is bonded, a second gap-filling material 613 is deposited to fill the space around the first semiconductor element 601 and provide additional support. In embodiments, the second gap-filling material 613 may be a material such as silicon oxide, silicon nitride, silicon oxynitride, or combinations thereof, which is deposited to fill and overfill the space around the first semiconductor element 601. However, any suitable material and deposition method may be used.

[0098] Once the second gap filler material 613 has been deposited, it can be planarized to expose the first semiconductor element 601. In embodiments, the planarization process can be a chemical mechanical planarization process, a polishing process, etc. However, any suitable planarization process can be used.

[0099] Figure 7 The diagram illustrates attaching a support substrate 701 to a first semiconductor element 601 and a second gap-filling material 613. In embodiments, the support substrate 701 may be a support material transparent to the wavelength of the light to be used, such as silicon, and may use, for example, adhesives ( Figure 7 (Not shown separately) for attachment. However, in other embodiments, the support substrate 701 may be attached to the first semiconductor element 601 and the second gap filler 613 using, for example, a bonding process. Any suitable method for attaching the support substrate 701 may be used.

[0100] Figure 7 It is also shown that the support substrate 701 includes a coupling lens 703, which is positioned to facilitate the flow of light from the optical fiber 905 ( Figure 7 Not shown in the text, but below regarding Figure 9 (Further shown and described) Movement to the grating coupler 204, the second optical component 503, or the third optical component 511 of the first metallization layer 501. In an embodiment, the coupling lens 703 can be formed by shaping the material of the support substrate (e.g., silicon) using a mask and etching process. However, any suitable process can be utilized.

[0101] Figure 8 The removal of the first substrate 101 and optionally the first insulating layer 103 is shown, thereby exposing the first active layer 201 of the first optical component 203 and the grating coupler 204. In embodiments, the first substrate 101 and the first insulating layer 103 can be removed using planarization processes such as chemical mechanical polishing, grinding processes, one or more etching processes, or combinations thereof. However, any suitable method can be used to remove the first substrate 101 and / or the first insulating layer 103.

[0102] Once the first substrate 101 and the first insulating layer 103 are removed, the second active layer 801 of the fourth optical component 803 can be formed on the back side of the first active layer 201. In an embodiment, the second active layer 801 of the fourth optical component 803 can be formed using similar materials and similar processes to those used for the second optical component 503 of the first metallization layer 501 (see above). Figure 5(Description). For example, the second active layer 801 of the fourth optical component 803 may be formed by alternating layers of a cladding material such as silicon oxide and a core material such as silicon nitride, formed using deposition and patterning processes, in order to form an optical component such as a waveguide.

[0103] Figure 9 The diagram illustrates the formation of a first through-device via (TDV) 901, the formation of a third bonding layer 903, and the placement of an optical fiber 905 to form a first optical package 900. In an embodiment, the first TDV 901 extends through the second active layer 801 and the first active layer 201 to provide a fast path for power, data, and ground through the optical medium 100. In an embodiment, the first TDV 901 can be formed by first forming a TDV opening into the optical medium 100. The TDV opening can be formed by applying and developing a suitable photoresist (not shown) and removing the exposed portions of the second active layer 801 and the optical medium 100.

[0104] Once the via opening is formed within the optical medium 100, a pad can be used to line the via opening. The pad can be, for example, an oxide formed of tetraethyl orthosilicate (TEOS) or silicon nitride, but any suitable dielectric material can be used alternatively. The pad can be formed using a plasma-enhanced chemical vapor deposition (PECVD) process, but other suitable processes such as physical vapor deposition or thermal processes can also be used.

[0105] Once a liner is formed along the sidewalls and bottom of the via opening, a barrier layer (not shown separately) can be formed, and the remainder of the via opening can be filled with a first conductive material. The first conductive material may include copper, but other suitable materials such as aluminum, alloys, doped polysilicon, combinations thereof, etc., may also be used. The first conductive material can be formed by electroplating copper onto a seed layer (not shown), filling and overfilling the via opening. Once the via opening has been filled, excess liner, barrier layer, seed layer, and first conductive material outside the via opening can be removed by a planarization process such as chemical mechanical polishing (CMP), but any suitable removal process can be used.

[0106] Optionally, in some embodiments, once the first element via 901 is formed, a second metallization layer electrically connected to the first element via 901 can be formed. Figure 9(Not shown separately). In embodiments, the second metallization layer can be formed as described above relative to the first metallization layer 501, for example, by using a damascene process, a dual damascene process, or the like to form alternating layers of dielectric and conductive materials. In other embodiments, an electroplating process can be used to form the second metallization layer to form and shape the conductive material, and then the conductive material can be covered with a dielectric material. However, any suitable structure and manufacturing method can be utilized.

[0107] The third bonding layer 903 is formed to provide an electrical connection between the optical medium 100 and the subsequently attached elements. In embodiments, the third bonding layer 903 may be similar to the first bonding layer 505, for example having a third bonding pad 909 (similar to the first bonding pad 507) or even a fifth optical element 911 (similar to the third optical element 511). However, any suitable element may be used.

[0108] Optionally, at this point in the process, fiber optic cable 905 can be attached. In an embodiment, fiber optic cable 905 is used as an optical input / output port of optical medium 100. In an embodiment, fiber optic cable 905 is positioned to connect fiber optic cable 905 and, for example, a grating coupler (…). Figure 9 Optical coupling is performed on the optical input (not shown separately), and the grating coupler is part of the first optical element 203, the second optical element 503, or the third optical element 511. By positioning the optical fiber 905 in this way, the optical signal leaving the optical fiber 905 is guided, for example, to the first active layer 201 of the first optical element 203 and the grating coupler 204. Similarly, the optical fiber 905 is positioned such that the optical signal leaving the first active layer 201 of the first optical element 203 is guided into the optical fiber 905 for transmission. However, any suitable location can be used.

[0109] The optical fiber 905 can be fixed in place using, for example, optical adhesive (not shown). In some embodiments, the optical adhesive comprises a polymeric material, such as an epoxy acrylate oligomer, and may have a refractive index between about 1 and about 3. However, any suitable material may be used.

[0110] Furthermore, although fiber 905 is shown attached at this point in the manufacturing process, this is intended to be illustrative and not limiting. Rather, fiber 905 can be attached at any suitable point in the process. Any suitable attachment point can be utilized, and all such attachments at any point in the process are fully intended to be included within the scope of this embodiment.

[0111] By utilizing the structure and method proposed in this paper, bidirectional reflectors can be applied to grating couplers that can be integrated into silicon photonics platforms, where grating couplers can achieve higher coupling efficiency. Furthermore, bidirectional reflectors, such as the back reflective layer 260 and the receiving reflective layer 265, can provide effective confinement and concentration of light energy. For example, by utilizing the characteristics of a double-layered metallic reflector (e.g., the back reflective layer 260 and the receiving reflective layer 265), the light beam can be effectively confined and concentrated, making the beam more focused and powerful. Bidirectional reflectors, such as the back reflective layer 260 and the receiving reflective layer 265, can provide multiple reflections that can improve the coupling and collection efficiency of the grating coupler 204. Through the multiple reflection mechanism of the back reflective layer 260, the light signal reflected from the bottom can be reused to improve the coupling and collection efficiency of the light signal, thereby achieving higher light signal collection and coupling efficiency. Moreover, bidirectional reflectors, such as the back reflective layer 260 and the receiving reflective layer 265, can provide improved efficiency in optical communication systems. In some embodiments, the optical communication system described herein may use a double-layer metal reflector, such as a back reflective layer 260 and a receiving reflective layer 265, to effectively focus the optical signal beam onto the entrance of the grating coupler, thereby improving the coupling and collection efficiency of the optical signal, and consequently increasing the efficiency of the optical receiver and transmitter. This can result in higher transmission rates and is suitable for longer transmission distances. The use of double-layer metal reflectors is not limited to grating couplers and can be widely applied to other optical components.

[0112] In some embodiments, a method of forming an optical element includes: forming a first reflective layer; forming a cladding layer on the first reflective layer; forming a grating layer on the cladding layer; and forming a second reflective layer on the cladding layer, wherein the second reflective layer includes an opening for receiving an optical signal to at least the grating layer. In an embodiment, forming the second reflective layer includes: depositing a metal layer over the grating layer; forming an etching mask on the metal layer, the etching mask being patterned to expose an opening portion of the metal layer; and etching the opening portion of the metal layer to form an opening for receiving an optical signal to at least the grating layer. In an embodiment, the opening of the second reflective layer is present on a first side of a grating coupler of the optical element for receiving an optical signal from an optical fiber, the first side of the grating coupler being opposite a second side of the grating coupler, wherein the second side of the grating coupler includes a waveguide interface portion and has a narrower width than the first side of the grating coupler. In an embodiment, the grating layer is a single material layer. In an embodiment, the single material layer providing the grating layer includes a bidirectional grating. In an embodiment, the grating layer is a multilayer structure. In an embodiment, the multilayer structure includes a first grating layer on the cladding layer and a second grating layer on the first grating layer. The first grating layer includes a broadband group grating with a height extending into a trench formed in the cladding layer. The second grating layer has a first group of gratings extending along a first direction and a second group of gratings extending along a second direction different from the first direction.

[0113] In another embodiment, the optical element includes: a back reflective layer; a cladding layer on the back reflective layer; a grating structure on the cladding layer; and a receiving reflective layer on the grating structure, wherein the receiving reflective layer includes an opening for receiving an optical signal to at least the grating structure. In an embodiment, the opening in the receiving reflective layer is present on a first side of a grating coupler of the optical element for receiving an optical signal from an optical fiber, the first side of the grating coupler being opposite a second side of the grating coupler, the second side of the grating coupler including a waveguide interface portion. In some embodiments, the width of the second side of the grating coupler is narrower than that of the first side of the grating coupler. In an embodiment, the cladding layer on the back reflective layer is a first cladding structure, wherein a second cladding structure is present between the receiving reflective layer and the grating structure. In an embodiment, the grating structure is a single layer including a single set of gratings having a height extending toward the receiving reflective layer. In an embodiment, the grating structure is a single layer including a first set of gratings extending along a first direction and a second set of gratings extending along a second direction in a second portion of the grating structure. In one embodiment, the grating structure is a single layer comprising a grating having a tapered width that decreases toward the waveguide junction. In another embodiment, the grating structure comprises two layers.

[0114] In another embodiment, the optical element includes: a back reflective layer; a cladding layer on the back reflective layer; a multilayer grating structure on the cladding layer; and a receiving reflective layer on the multilayer grating structure, wherein the receiving reflective layer includes an opening for receiving an optical signal into at least one single-layer grating layer. In some embodiments, the opening in the receiving reflective layer is present on a first side of a grating coupler of the optical element for receiving an optical signal from an optical fiber, the first side of the grating coupler being opposite a second side of the grating coupler, the second side of the grating coupler including a waveguide interface portion. In some embodiments, the width of the second side of the grating coupler is narrower than that of the first side of the grating coupler. In an embodiment, the cladding layer on the back reflective layer is a first cladding structure, wherein a second cladding structure exists between the receiving reflective layer and the single-layer grating structure. In one embodiment, the multilayer grating structure includes: a first grating layer present on a cladding layer, the first grating layer having a plurality of trenches; and a second grating layer present on the first grating layer, the second grating layer having a first set of gratings on an upper surface of the second grating layer and a second set of gratings on a lower surface of the second grating layer intersecting with the first grating layer, wherein the first set of gratings has a height extending along a first direction, and the second set of gratings extends along a second direction into the plurality of trenches in the first grating layer. In another embodiment, the optical element further includes a third set of gratings at the junction of the first grating layer and the cladding layer. In yet another embodiment, the multilayer grating structure has a tapered width that decreases toward the waveguide junction.

[0115] The foregoing has outlined features of several embodiments to enable those skilled in the art to better understand aspects of the invention. Those skilled in the art will understand that they can readily use this disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or advantages as the embodiments described herein. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made without departing from the spirit and scope of this disclosure.

Claims

1. An optical element, characterized in that, include: Back reflective layer; A coating layer is applied to the back reflective layer. A grating structure is present on the covering layer; as well as A receiving reflective layer is provided on the grating structure, wherein the receiving reflective layer includes an opening.

2. The optical element according to claim 1, characterized in that, The covering layer on the back reflective layer is a first covering structure, wherein a second covering structure exists between the receiving reflective layer and the grating structure.

3. The optical element according to claim 1, characterized in that, The grating structure is a single layer comprising a single set of gratings, the single set of gratings having a height extending toward the receiving and reflecting layer.

4. The optical element according to claim 1, characterized in that, The grating structure is a single layer, and the single layer includes a first set of gratings extending along a first direction and a second set of gratings extending along a second direction in a second part of the grating structure.

5. The optical element according to claim 1, characterized in that, The grating structure is a single layer, the single layer comprising a grating having a tapered width that decreases toward the waveguide junction.

6. The optical element according to claim 1, characterized in that, The grating structure comprises two layers.

7. An optical element, characterized in that, include: Back reflective layer; A coating layer is applied to the back reflective layer. A multilayer grating structure is provided on the covering layer; as well as A receiving reflective layer is provided on the multilayer grating structure, wherein the receiving reflective layer includes an opening.

8. The optical element according to claim 7, characterized in that, The covering layer on the back reflective layer is a first covering structure, wherein a second covering structure exists between the receiving reflective layer and the multilayer grating structure.

9. The optical element according to claim 7, characterized in that, The multilayer grating structure includes: A first grating layer exists on the cladding layer, and the first grating layer has multiple trenches; and A second grating layer exists on the first grating layer, the second grating layer having a first set of gratings on the upper surface of the second grating layer and a second set of gratings on the lower surface of the second grating layer at the junction with the first grating layer, wherein the first set of gratings has a height extending along a first direction, and the second set of gratings extends along a second direction into the plurality of trenches in the first grating layer.

10. The optical element according to claim 9, characterized in that, Also includes: The third set of gratings is located at the junction of the first grating layer and the covering layer.

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