Optical system and method for manufacturing an optical connection device

Abstract

The embodiment of the invention discloses an optical system with different optical connecting device configurations and a manufacturing method thereof. The optical system includes: a substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; and an optical connection device disposed between the optical fiber and the waveguide. The optical connection device is configured to optically connect the optical fiber to the waveguide. An optical connection device includes a dielectric layer disposed on a substrate, a semiconductor tapered structure disposed in a first horizontal plane within the dielectric layer, and a multi-tip dielectric structure disposed in a second horizontal plane within the dielectric layer. The first and second horizontal planes are different from each other. The embodiment of the invention provides an optical system and a method for manufacturing an optical connecting device.

Description

[0001] Divisional application

[0002] This application is a divisional application of the patent application entitled “Optical system and method for manufacturing optical connection device” filed on January 27, 2021 and with patent application number 202110107703.4. Technical Field

[0003] Embodiments of the present application relate to an optical system and a method for manufacturing an optical connection device. Background Art

[0004] One of the methods of connecting a single-mode optical fiber to a waveguide on a silicon (Si) photonic integrated circuit (PIC) is to optically connect the sides of the optical fiber and the Si-PIC with an optical connection device such as an edge connector. The edge connector reduces the optical mode size mismatch between the optical fiber and the waveguide and is used to transmit light between the optical fiber and the Si-PIC. The edge connection operates over a wider wavelength range, can achieve polarization-insensitive connections (e.g., connecting both TE / TM modes), and is compatible with semiconductor technology. However, in order to meet the growing demand for faster processing systems, scaling down the size of Si-PICs has increased the complexity of manufacturing edge connectors with high optical connection efficiency. Summary of the invention

[0005] In some embodiments, an optical system includes: a substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; and an optical connection device disposed between the optical fiber and the waveguide and configured to optically connect the optical fiber to the waveguide, wherein the optical connection device includes a dielectric layer disposed on the substrate, a semiconductor tapered structure disposed in a first horizontal plane within the dielectric layer, and a multi-tip dielectric structure disposed in a second horizontal plane within the dielectric layer, and wherein the first horizontal plane and the second horizontal plane are different from each other.

[0006] In some embodiments, an optical system includes: a substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; and an optical connection device disposed between the optical fiber and the waveguide and configured to optically connect the optical fiber to the waveguide, wherein the optical connection device includes a dielectric layer disposed on the substrate, a multi-tip semiconductor structure having an array of semiconductor layers disposed within the dielectric layer, and a semiconductor tapered structure disposed on the multi-tip semiconductor structure and in physical contact with the multi-tip semiconductor structure.

[0007] In some embodiments, a method for manufacturing an optical connection device includes: forming a semiconductor tapered structure located on a silicon-on-insulator (SOI) substrate; depositing a first dielectric layer located on the semiconductor tapered structure; forming a multi-tip dielectric structure having an array of dielectric structures located on the first dielectric layer; and depositing a second dielectric layer located on the multi-tip dielectric structure.

[0008] Embodiments of the present application provide a multi-tip optical connection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] When read in conjunction with the accompanying drawings, various aspects of the present invention can be best understood from the following detailed description. It should be noted that, in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, for clarity of discussion, the size of the various components may be arbitrarily increased or reduced.

[0010] Figure 1A , Figure 1B-Figure 1E ,and Figure 1F shows a top view, a cross-sectional view, and device characteristics of an optical system according to some embodiments;

[0011] Figure 2A-2C shows a cross-sectional view of an optical system according to some embodiments;

[0012] Figure 3A-3C shows a cross-sectional view of an optical system according to some embodiments;

[0013] Figure 4A-4C shows a cross-sectional view of an optical system according to some embodiments;

[0014] Figure 5A-5D shows a top view and a cross-sectional view of an optical system according to some embodiments;

[0015] Figure 6A-6E shows a top view and a cross-sectional view of an optical system according to some embodiments;

[0016] Figure 7 is a flow chart of a method for manufacturing an optical connection device according to some embodiments;

[0017] Figure 8A-8F Cross-sectional views of an optical connection device at various stages of its manufacturing process are shown according to some embodiments.

[0018] Illustrative embodiments will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements. DETAILED DESCRIPTION

[0019] The following disclosure provides many different embodiments or examples for realizing different features of the present invention. Specific examples of components and arrangements are described below to simplify the present invention. Of course, these are merely examples and are not intended to limit the present invention. For example, in the following description, forming a first component above or on a second component may include an embodiment in which the first component and the second component are directly contacted, and may also include an embodiment in which an additional component may be formed between the first component and the second component so that the first component and the second component may not be in direct contact. Forming a first component on a second component as used herein means that the first component is formed to be in direct contact with the second component. In addition, the present invention may repeat reference numbers and / or letters in various examples. This repetition itself does not indicate the relationship between the various embodiments and / or structures discussed.

[0020] For ease of description, spatially relative terms such as "under," "beneath," "lower," "over," "upper," etc. may be used herein to easily describe the relationship of one element or component to another (or additional) elements or components as shown in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

[0021] It is worth noting that references to "one embodiment," "an embodiment," "an exemplary embodiment," "exemplary," etc. in the specification indicate that the described embodiments may include specific components, structures, or characteristics, but each embodiment does not necessarily include specific components, structures, or characteristics. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a specific component, structure, or characteristic is described in conjunction with an embodiment, whether or not explicitly described, it is within the knowledge of those skilled in the art to implement such component, structure, or characteristic in conjunction with other embodiments.

[0022] It should be understood that the phraseology or terminology herein is for the purpose of description rather than limitation, and thus the phraseology or terminology of this specification will be interpreted by those skilled in the relevant (some) fields based on the teachings herein.

[0023] As used herein, the term "high-k" refers to a high dielectric constant. In the field of semiconductor device structure and manufacturing process, high-k refers to a dielectric constant greater than the dielectric constant of SiO2 (eg, greater than 3.9).

[0024] As used herein, the term "low-k" refers to a low dielectric constant. In the field of semiconductor device structure and manufacturing process, low-k refers to a dielectric constant that is less than the dielectric constant of SiO2 (eg, less than 3.9).

[0025] As used herein, the term "low refractive index" refers to a refractive index that is less than the refractive index of Si (eg, less than 3.5).

[0026] As used herein, the term "nanostructured" is defined as structures, layers, and / or regions having horizontal dimensions (eg, along the X and / or Y axes) and / or vertical dimensions (eg, along the Z axis) less than, for example, 100 nm.

[0027] In some embodiments, the terms "about" and "substantially" may indicate a value of a given quantity that varies within 5% of the value (e.g., ±1%, ±2%, ±3%, ±4%, ±5% of the value). These values ​​are examples only and are not intended to be limiting. It should be understood that the terms "approximately" and "substantially" may refer to a percentage of a value of a given quantity as interpreted by a person skilled in the relevant (some) art(s) in accordance with the teachings herein.

[0028] Compared to the silicon waveguide on the silicon photonic integrated circuit, the single-mode optical fiber can have a relatively large core, thereby producing an optical mode field larger than the mode associated with the silicon waveguide on the silicon photonic integrated circuit. A direct optical connection between the optical fiber and the silicon waveguide on the silicon photonic integrated circuit will result in high optical connection loss and high optical signal loss due to the optical mode size mismatch and the refractive index mismatch between the optical fiber and the waveguide on the silicon photonic integrated circuit. In order to reduce this optical mode size mismatch and refractive index mismatch, an optical connection device (also called an "edge connector") can be used to optically connect the optical fiber to the silicon waveguide on the silicon photonic integrated circuit. Each optical connection device generally has a semiconductor tapered structure and a single-tip dielectric structure surrounding the semiconductor tapered structure. The semiconductor tapered structure may include silicon, and the single-tip dielectric structure may include silicon nitride (SiN). The refractive index mismatch between SiN (e.g., a refractive index of about 2.0) and the optical fiber (e.g., a refractive index of about 1.45) is lower than the refractive index mismatch between the optical fiber and the silicon waveguide on the silicon photonic integrated circuit (e.g., a refractive index of about 3.5).

[0029] The single-tip dielectric structure is used as a single-mode waveguide, which is configured to collect light from an optical fiber and transmit the collected light to a semiconductor tapered structure. The end of the single-tip dielectric structure is optically connected to the side of the optical fiber, and when the light propagates along the single-tip dielectric structure, it is temporarily connected to the semiconductor tapered structure. The single-tip dielectric structure configuration has a smaller optical mode size mismatch with the optical fiber than the optical mode size mismatch between the optical fiber and the silicon waveguide on the silicon photonic integrated circuit.

[0030] Similarly, the semiconductor tapered structure is used as a single-mode waveguide, which is configured to collect light from the single-tip dielectric structure and transmit the collected light to the silicon waveguide on the silicon photonic integrated circuit. The end of the semiconductor tapered structure is optically connected to the single-tip dielectric structure, and the other end of the semiconductor tapered structure is optically connected to the side of the silicon waveguide on the silicon photonic integrated circuit. Compared with the optical mode size mismatch between the optical fiber and the silicon waveguide on the silicon photonic integrated circuit, the semiconductor tapered structure is configured to have a smaller optical mode size mismatch with the silicon waveguide on the silicon photonic integrated circuit. Therefore, the optical connection device is used as an optical mode size converter to improve the optical connection efficiency between the optical fiber and the silicon waveguide on the silicon photonic integrated circuit.

[0031] The dielectric material used for the single-tip dielectric structure limits the optical mode size that can be obtained for the single-tip dielectric structure, thereby limiting the minimum optical mode size mismatch and the maximum optical connection efficiency that can be achieved between the optical connection device and the optical fiber. This limitation is due to the complex process for manufacturing a single-tip dielectric structure with a thick SiN layer (e.g., a thickness of about 200nm or greater, or a thickness of about 250nm) based on silicon nitride (SiN) to achieve a preferred optical connection efficiency. The complex manufacturing process for the SiN structure is required to protect the underlying layer and / or structure so that during the processing (e.g., patterning, etching, and / or polishing) of the SiN material (which is a high stress material), it can be protected from possible damage. For example, in order to obtain a SiN layer having a thickness greater than 200nm (e.g., about 200nm to about 800nm), multiple coatings, patterning, etching, and / or polishing processes can be used in the manufacturing process to protect the underlying layer from damage caused by stress, such as cracks in the substrate of the optical connection device. Forming SiN-based single-tip dielectric structures thinner (eg, less than 200 nm) may exhibit low connection efficiency and / or strongly polarization-affected connection losses.

[0032] The present invention provides exemplary optical connection devices having a multi-tip dielectric structure having a thickness of less than about 200 nm. Such exemplary optical connection devices can provide improved optical connection efficiency between the optical connection device and the optical fiber, thereby improving the optical connection efficiency between the optical fiber and the silicon waveguide on the silicon photonic integrated circuit. The present invention also provides methods for manufacturing these exemplary optical connection devices, which have fewer and fewer complex processing steps compared to methods for manufacturing optical connection devices with single-tip dielectric structures without sacrificing device performance of the exemplary optical connection devices.

[0033] In some embodiments, exemplary optical connection devices may include semiconductor tapered structures and multi-tip dielectric structures. Semiconductor tapered structures and multi-tip dielectric structures may be arranged in dielectric layers at different levels from each other. In some embodiments, multi-tip dielectric structures may include arrays of SiN layers or other suitable dielectric layers (e.g., silicon high oxide (SiXO), aluminum oxide (Al2O3), aluminum nitride (AlN), lithium niobate (LiNbO3), hafnium oxide (HfO2), titanium oxide (TiO2), zinc oxide (ZnO), and germanium oxide (GeO2)). The side of the SiN layer facing the optical fiber forms the tip of the multi-tip dielectric structure. Each tip has a vertical dimension (e.g., thickness or height) along the Z axis less than about 200nm (e.g., about 90nm), and a horizontal dimension (e.g., width) along the Y axis greater than about 100nm (e.g., about 200nm to about 500nm). Other suitable sizes of multi-tip dielectric structures are within the scope of the present invention.

[0034] Since the multi-tip dielectric structure has a thinner SiN layer than the single-tip dielectric structure based on SiN, the complexity and number of process steps involved in the manufacture of the exemplary optical connection device are reduced. In some embodiments, the multi-tip dielectric structure can be manufactured by one etching step. Unlike the manufacturing process of the single-tip dielectric structure based on SiN, the manufacturing process of the multi-tip dielectric structure may not require high-resolution mask alignment, complex processes, or nano-scale etching process control.

[0035] The multi-tip dielectric structure allows for greater flexibility in configuring the exemplary optical connector to achieve different optical mode sizes to match optical fibers with different core sizes. By adjusting the size of the SiN structure and the spacing between the SiN structures, different optical mode sizes can be optimized to achieve maximum connection efficiency with the optical fiber. In some embodiments, the multi-tip dielectric structure may include a two-dimensional array of SiN structures or other suitable dielectric structures to further improve the optical connection efficiency between the exemplary optical connector and the optical fiber. In some embodiments, the exemplary optical connector has a higher tolerance for misalignment between the optical fiber and the multi-tip dielectric structure for two polarization pairs compared to a single-tip dielectric structured optical connector. For a misalignment of 0.5 μm between the optical fiber and the multi-tip dielectric structure, the optical loss is less than 1 dB. The exemplary optical connector can also achieve low polarization-related optical connection losses.

[0036] According to some embodiments, reference Figure 1A-1F An optical system 100 having an optical connection device 102 (also referred to as an “edge connector 102 ”), a silicon-based waveguide 104 , and an optical fiber 106 is depicted. Figure 1AA top view of an optical system 100 is shown, according to some embodiments. Figure 1B-Figure 1E According to some embodiments, Figure 1A-1B Cross-sectional views along lines AA, BB, CC, and DD. Figure 1F Device characteristics of the optical system 100 according to some embodiments are shown.

[0037] The optical connection device 102 can be configured to optically connect the silicon-based waveguide 104 to the optical fiber 106. In some embodiments, the optical connection device 102 may include a substrate 102A, a dielectric layer 102B disposed on the substrate 102A, a semiconductor tapered structure 102C disposed in a horizontal plane 108 within the dielectric layer 102B, and a multi-tip dielectric structure 102D disposed in a horizontal plane 110 within the dielectric layer 102B. The multi-tip dielectric structure 102D can be configured to collect light from the optical fiber 106. The semiconductor tapered structure 102C can be configured to collect light from the multi-tip dielectric structure 102D and transmit the collected light to the waveguide 104. The substrate 102A can include semiconductor materials such as silicon (Si), germanium (Ge), and silicon germanium (SiGe). In some embodiments, the waveguide 104 can be disposed in the dielectric layer 102B and can be in physical contact with the semiconductor tapered structure 102C. In some embodiments, the waveguide 104 and the semiconductor tapered structure 102C may be a single semiconductor structure having the same semiconductor material, such as silicon (Si). In some embodiments, the dielectric layer 102B may include an oxide material, such as silicon oxide (SiO2).

[0038] In some embodiments, Figure 1A As shown, the multi-tip dielectric structure 102D may include a one-dimensional ("1-D") array of dielectric layers extending between the waveguide 104 and the optical fiber 106. The 1-D array of dielectric layers may include a high-k dielectric material having a low refractive index, such as SiN, SixO, Al2O3, AlN, LiNbO3, HfO2, TiO2, ZnO, GeO2, and combinations thereof, or other suitable high-k dielectric materials. The refractive index of the dielectric material of the 1-D array of dielectric structures may be greater than the refractive index of the optical fiber 106 and less than the refractive index of the waveguide 104. The refractive index of the dielectric material of the 1-D array of dielectric structures may be less than the refractive index of the semiconductor tapered structure 102C. Each of the sides 102Dt of the dielectric structure facing the optical fiber 106 forms a tip 102Dt of the multi-tip dielectric structure 102D, such as Figure 1A-1B and Figure 1E As shown. The tip 102Dt can be used as Figure 1A-1BThe tip 102Dt is shown in physical contact with the optical fiber 106 and can be configured to collect light from the optical fiber 106 during operation. In some embodiments, there can be a gap (not shown) between the tip 102Dt and the optical fiber 106, wherein the tip 102Dt can be optically connected to the optical fiber 106. Although the tip 102Dt is shown as having a rectangular cross-section, the tip 102Dt can have a cross-section of any geometric shape (e.g., circular, semicircular, triangular, or polygonal).

[0039] The number of dielectric structures in the 1-D array of dielectric structures and the size of the dielectric structures depend on the material properties and the optical mode shape and size of the optical fiber 106. The number and size of the dielectric structures can be adjusted during manufacturing to substantially match the optical mode shape and size of the multi-tip dielectric structure 102D with the optical mode shape and size of the optical fiber 106. In some embodiments, the optical mode size of the multi-tip dielectric structure 102D along the Z axis can be adjusted to match the optical mode of the optical fiber 106 by adjusting the vertical dimension 102Dh of the dielectric layer of the multi-tip dielectric structure 102D along the Z axis. In some embodiments, the optical mode shape of the multi-tip dielectric structure 102D along the Y axis can be adjusted to match the optical mode of the optical fiber 106 by adjusting the horizontal dimension 102Dw of the dielectric layer of the multi-tip dielectric structure 102D along the Y axis. The vertical dimension 102Dh and the horizontal dimension 102Dw of the dielectric structure are the vertical dimension and the horizontal dimension of the tip 102Dt. Thus, adjustment of the vertical dimension 102Dh and the horizontal dimension 102Dw of the dielectric structure may tune the optical mode of the tip 102Dt optically connected to the optical fiber 106 .

[0040] In some embodiments, the multi-tip dielectric structure 102D can be fabricated to have a vertical dimension 102Dh and horizontal dimensions 102Dw and 102Dl, so that the multi-tip dielectric structure 102D can be used as a waveguide that supports only the fundamental optical mode. In some embodiments, for the multi-tip dielectric structure 102D used as a waveguide that supports only the fundamental optical mode, the vertical dimension 102Dh can be equal to or less than about 200nm (e.g., about 90nm), and the horizontal dimension 102Dw can be equal to or greater than 100nm (e.g., about 200nm to about 500nm). The vertical spacing 102Ds between the multi-tip dielectric structure 102D and the substrate 102A can be equal to or greater than about 2μm (e.g., about 2.1μm to about 10μm), or can be other suitable dimensions. The horizontal spacing along the Y-axis between adjacent dielectric structures of the multi-tip dielectric structure 102D can be equal to or greater than 200nm (e.g., about 200nm to about 500nm), or can be other suitable dimensions. The number of dielectric structures may be between 2 and 20. If the number of dielectric structures is less than 2, the multi-tip dielectric structure 102D may not adequately function as a waveguide supporting only the fundamental optical mode. On the other hand, if the number of dielectric structures is greater than 20, the processing time increases, and thus the device manufacturing cost increases. Figure 1F In some embodiments, the multi-tip dielectric structure 102D can have an optical connection efficiency greater than 90% (e.g., about 91% to about 94%), or can be other suitable values, and the optical connection loss is less than 1 dB for a misalignment of about 0.5 μm between the multi-tip dielectric structure 102D and the optical axis of the optical fiber 106 along the Y-axis (not shown).

[0041] Can be replaced by Figure 1C-1E The dielectric structure of the multi-tip dielectric structure 102D having the same horizontal dimensions 102Dw and 102Dl is shown as Figure 2A-2C The horizontal dimension along the Y-axis of one or more of the dielectric structures shown may be different from that of other dielectric structures. Figure 2A-2C As shown, the horizontal dimensions of adjacent dielectric structures along the Y-axis may be different from each other. Figure 2A-2C As shown, the horizontal spacing along the Y-axis between adjacent dielectric structures may be different from each other and may be equal to or greater than 100 nm (eg, about 105 nm to about 500 nm), or may be other suitable dimensions. Figure 2A-2C 1 shows different configurations for the multi-tip dielectric structure 102D according to some embodiments. Figure 1A Unless otherwise stated, Figure 1A-1E and Figure 2A-2C Discussions of elements with the same annotation apply to each other.

[0042] Instead of or in addition to adjusting the number and size of dielectric structures of the multi-tip dielectric structure 102D, the layout configuration of the dielectric structures may be adjusted so that Figure 3A-Figure 4C The optical mode shape and size of the multi-tip dielectric structure 102D are shown to match the optical mode shape and size of the optical fiber 106. Figure 3A-Figure 4C 1 shows different configurations for the multi-tip dielectric structure 102D according to some embodiments. Figure 1A Unless otherwise stated, Figure 1A-1E and Figure 3A-Figure 4C Discussions of elements with the same annotation apply to each other.

[0043] refer to Figure 3A-Figure 4C Instead of a 1-D array of dielectric structures, the multi-tip dielectric structure 102D may include a two-dimensional ("2-D") array of dielectric structures extending between the waveguide 104 and the optical fiber 106. The 2-D array of dielectric structures may include a high-k dielectric material having a low refractive index, such as SiN, SixO, Al2O3, AlN, LiNbO3, HfO2, TiO2, ZnO, GeO2, and combinations thereof, or other suitable high-k dielectric materials. The dielectric structures in each row of the 2-D array of dielectric structures may have the same dielectric material, or may have different dielectric materials. Each row of the 2-D array of dielectric structures may have a dielectric structure having a plurality of dielectric structures. Figure 3A-3C The same arrangement of dielectric structures as shown, or each row may have Figure 4A-4C Different arrangements of dielectric structures are shown. The vertical spacing along the Z-axis between dielectric structures in the 2-D array of dielectric structures can be greater than 50 nm (e.g., from about 50 nm to about 500 nm), or can be other suitable dimensions. The layout and dimensions of the dielectric structures in the 2-D array of dielectric structures can be configured so that the multi-tip dielectric structure 102D can be used as a waveguide that supports only a fundamental optical mode. The 2D array of dielectric structures 102D provides greater flexibility in the manufacture of multi-tip dielectric structures with a wide range of optical mode sizes for matching a wide range of optical mode sizes of the optical fiber 106.

[0044] In some embodiments, the vertical spacing 102Cs along the Z-axis between the multi-tip dielectric structure 102D and the semiconductor tapered structure 102C can be greater than 20 nm (e.g., about 20 nm to about 500 nm), or can be other suitable dimensions. The horizontal dimension 102Ctw along the Y-axis of the tip 102Ct of the semiconductor tapered structure 102C can be in the range of about 50 nm to about 400 nm, or can be other suitable dimensions. In some embodiments, as Figure 1AAs shown, the base 102Cb of the semiconductor tapered structure 102C can be substantially aligned with the base 102Db of the multi-tip dielectric structure 102D along the Y axis. The ratio of the horizontal dimension of the base 102Cb along the Y axis to the horizontal dimension of the tip 102Ct along the Y axis can be in the range of about 2 to about 20. The horizontal dimension of the semiconductor tapered structure 102C along the X axis can be in the range of 10 μm to about 500 μm. The distance between the tip 102Ct and the tip 102Dt along the Y axis can be about 1 μm to about 5 μm. Figure 1A The horizontal pitch of the X-axis shown in may be in the range of about 1 μm to about 100 μm.

[0045] refer to Figure 5A-5D , the optical connection device 102 may include a single-tip dielectric structure 102D* instead of a multi-tip dielectric structure 102D. Figure 5A A top view of an optical connection device 102 is shown, according to some embodiments. Figure 5B-5D According to some embodiments, Figure 5A Unless otherwise stated, Figures 1A-1E The discussion of elements having the same annotations in 5A-5D applies to each other.

[0046] The single-tip dielectric structure 102D* may include a high-k dielectric material having a low refractive index, such as SiN, SixO, Al2O3, AlN, LiNbO3, HfO2, TiO2, ZnO, GeO2, and combinations thereof, or other suitable high-k dielectric materials. The refractive index of the dielectric material may be greater than the refractive index of the optical fiber 106 and less than the refractive index of the waveguide 104. The refractive index of the dielectric material may be less than the refractive index of the semiconductor tapered structure 102C. The side 102Dt* of the single-tip dielectric structure 102D* facing the optical fiber 106 forms a tip 102Dt* of the single-tip dielectric structure 102D*. The tip 102Dt* may be as shown in FIG. Figure 5A It is shown in physical contact with the optical fiber 106 and can be configured to collect light from the optical fiber 106 during operation. Although the tip 102Dt* is shown as having a rectangular cross-section, the tip 102Dt* can have a cross-section of any geometric shape (e.g., circular, semicircular, triangular, or polygonal).

[0047] Similar to the multi-tip dielectric structure 102D, there may be a vertical spacing 102Cs between the semiconductor tapered structure 102C and the single-tip dielectric structure 102D*, such as Figure 5B-Figure 5C As shown, the back reflection of light is reduced and the transient connection strength between the semiconductor tapered structure 102C and the single-tip dielectric structure 102D* is tuned. In some embodiments, a dielectric structure 102Ct and a dielectric structure 102Dt* are connected along the tip 102Ct and the single-tip dielectric structure 102Dt*. Figure 5AThere is a horizontal spacing between the X-axis shown. The horizontal spacing between the tip 102Ct and the tip 102Dt* can be in the range of about 1 μm to about 100 μm. In some embodiments, as Figure 5A As shown, the base 102Cb of the semiconductor tapered structure 102C can be aligned with the base 102Db* of the single-tip dielectric structure 102D* along the Y axis. In some embodiments, the vertical dimension of the single-tip dielectric structure 102D* along the Z axis can be in the range of about 200 nm to about 1000 nm, and the horizontal dimension of the single-tip dielectric structure 102D* along the Y axis can be in the range of about 200 nm to about 1000 nm. Other suitable dimensions of the single-tip dielectric structure 102D* are within the scope of the present invention.

[0048] According to some embodiments, reference Figure 6A-6E An optical system 600 having an optical connection device 602 (also referred to as an “edge connector 602 ”), a Si-based ridge waveguide 604 , and an optical fiber 106 is depicted. Fig. 6A A top view of an optical system 600 is shown, according to some embodiments. Figure 6B-Figure 6E According to some embodiments, Figure 6A-6B Unless otherwise specified, Figure 1A-1E and Figure 6A-6E The discussion of elements with the same annotations in FIG. 6 is applicable to each other. The optical connection device 602 can be configured to optically connect the Si-based waveguide 604 to the optical fiber 106.

[0049] In some embodiments, the optical connection device 602 may include a substrate 102A, a dielectric layer 102B disposed on the substrate 102A, and a semiconductor tapered structure 602C disposed within the dielectric layer 102B and disposed on a multi-tip semiconductor structure 602D. The multi-tip semiconductor structure 602D may include a 1-D array of semiconductor structures. The semiconductor tapered structure 602C may be, for example, Figure 6B-6DThe semiconductor structure of the 1-D array of semiconductor structures shown in FIG. 602C and the semiconductor structure of the 1-D array of semiconductor structures below the semiconductor tapered structure 602C form a single semiconductor structure 601, which includes a semiconductor material such as silicon (Si). The semiconductor structure of the 1-D array of semiconductor structures that does not overlap with the semiconductor tapered structure 602C may include the same semiconductor material as the semiconductor tapered structure 602C. The multi-tip semiconductor structure 602D may be configured to collect light from the optical fiber 106. The semiconductor tapered structure 602C may be configured to collect light from the multi-tip semiconductor structure 602D, and transmit the collected light to the waveguide 604. The substrate 102A may include semiconductor materials such as silicon (Si), germanium (Ge), and silicon germanium (SiGe). In some embodiments, the waveguide 604 and the optical connection device 602 may be a single semiconductor structure having the same semiconductor material (e.g., silicon (Si)). In some embodiments, the dielectric layer 102B may include an oxide material such as silicon oxide (SiO2).

[0050] Each of the side surfaces 602Dt of the multi-tip semiconductor structure 602D facing the optical fiber 106 forms a tip 602Dt of the multi-tip semiconductor structure 602D. Figure 6A-6B and Fig. 6E As shown. The tip 602Dt can be used with Figure 6A-6B The optical fiber 106 is shown in physical contact and can be configured to collect light from the optical fiber 106 during operation. Although the tip 602Dt is shown as having a rectangular cross-section, the tip 602Dt can have a cross-section of any geometric shape (eg, circular, semicircular, triangular, or polygonal).

[0051] The number of tips 602Dt and the size of the semiconductor structures in the 1-D array depends on the optical mode shape and size of the optical fiber 106. The number and size of the semiconductor structures can be adjusted during manufacturing to substantially match the optical mode shape and size of the multi-tip semiconductor structure 602D with the optical mode shape and size of the optical fiber 106. In some embodiments, the optical mode size of the multi-tip semiconductor structure 602D can be adjusted to match the optical mode size of the optical fiber 106 by adjusting the vertical dimensions T1 and T2 of the multi-tip semiconductor structure 602D along the Z axis. In some embodiments, the optical mode shape of the multi-tip semiconductor structure 602D can be adjusted to match the optical mode shape of the optical fiber 106 by adjusting the horizontal dimensions (e.g., W1, W2, S1, S2) of the multi-tip semiconductor structure 602D along the Y axis.

[0052] In some embodiments, the multi-tip semiconductor structure 602D can be manufactured to have a vertical dimension T1-T2, and horizontal dimensions W1-W2, S1-S2, so that the multi-tip semiconductor structure 602D can be used as a waveguide with only a fundamental optical mode. In some embodiments, the vertical dimension T1 can be in the range of about 50nm to about 200nm, and the vertical dimension T2 can be in the range of about 100nm to about 500nm. The horizontal dimension W1-W2 can be equal to or less than 400nm (for example, about 50nm to about 200nm). In some embodiments, the horizontal dimensions W1-W2 can be the same or different from each other. The vertical spacing 602Ds between the multi-tip semiconductor structure 602D and the substrate 102A can be equal to or greater than about 2μm (for example, about 2.1μm to about 10μm). The horizontal spacing S1-S2 along the Y axis between adjacent semiconductor structures of the 1-D array of multi-tip semiconductor structures 602D can be equal to or greater than 100nm (for example, about 100nm to about 1000nm). In some embodiments, the horizontal spacings S1-S2 may be equal to or different from each other. The number of semiconductor structures in the 1-D array may be about 2 to about 20. In some embodiments, as Fig. 6A As shown, the horizontal dimension of the semiconductor tapered structure 602C along the Y-axis is smaller than the horizontal dimension of the semiconductor layer of the 1-D array located below the semiconductor tapered structure 602C.

[0053] The cross-sectional shapes of the optical connectors 102 and 602 and their components are illustrative and are not intended to be limiting.

[0054] Figure 7 FIG. 7 is a flow chart of an exemplary method 700 for manufacturing an optical connector 102 according to some embodiments. For purposes of illustration, reference will be made to forming a Figure 8A-8F The exemplary manufacturing process of the optical connection device 102 is described as follows. Figure 7 The operation shown. Figure 8A-8F 700 is a cross-sectional view along line BB of the optical connector 102 at various stages of manufacture according to some embodiments. The operations may be performed in a different order, or may not be performed depending on the particular application. The method 700 may not produce a complete optical connector 102. Accordingly, other processes may be provided before, during, and after the method 700, and only some of the other processes are briefly described herein. Figures 1A-1E The components in the same annotation Figures 8A-8F Middle component.

[0055] In operation 705, a silicon-on-insulator (SOI) substrate is provided. Fig. 8AAs shown, an SOI substrate 800 may be provided. The SOI substrate 800 may include a substrate 102A, a dielectric layer 102B1 disposed on the substrate 102A, and a silicon layer 102C* disposed on the dielectric layer 102B1. During subsequent processing, the silicon layer 102C* may be processed to form a semiconductor tapered structure 102C. In some embodiments, the dielectric layer 102B1 may include an oxide material, such as silicon oxide (SiO2).

[0056] refer to Figure 7 In operation 710, a semiconductor tapered structure is formed on an SOI substrate. Figure 8B As shown, the semiconductor tapered structure 102C may be formed on the SOI substrate 800. The formation of the semiconductor tapered structure 102C may include sequential operations of: (i) thinning the silicon layer 102C* to a thickness of about 50 nm to about 200 nm; and (ii) patterning and etching the thinned silicon layer 102C* to form Figure 8B structure.

[0057] refer to Figure 7 In operation 715, a first dielectric layer is deposited on the semiconductor tapered structure. Figure 8C As shown, the first dielectric layer 102B2 may be deposited on Figure 8B In terms of structure, Figure 8C The deposition of the first dielectric layer 102B2 may include using a PECVD process. Figure 8B A dielectric material having a thickness of about 50 nm to about 800 nm is deposited on the structure of FIG. The deposited dielectric material may be the same as the dielectric material included in the dielectric layer 102B1 .

[0058] refer to Figure 7 In operation 720, a multi-tip dielectric structure may be formed on the first dielectric layer. Fig. 8E As shown, the multi-tip dielectric structure 102D can be formed on the first dielectric layer 102B2. The formation of the multi-tip dielectric structure 102D may include the following sequential operations: (i) using ALD or CVD process on the first dielectric layer 102B2; Figure 8C The structure is covered with high-k and low-refractive-index dielectric materials having a thickness of about 50 nm to about 200 nm to form a Fig.8D The dielectric layer 102D* shown; and (ii) patterning and etching the dielectric layer 102D* to form Fig. 8E The dielectric layer 102D* may include high-k and low-refractive index dielectric materials, such as SiN, SixO, Al2O3, AlN, LiNbO3, HfO2, TiO2, ZnO, GeO2, or a combination thereof, or other suitable high-k dielectric materials.

[0059] refer to Figure 7 In operation 725, a second dielectric layer is deposited on the multi-tip dielectric structure. Fig.8F As shown, the second dielectric layer 102B3 may be deposited on Fig. 8E In terms of structure, Fig.8F The deposition of the second dielectric layer 102B3 may include using a PECVD process on Fig. 8E A dielectric material having a thickness of about 100 nm to about 1000 nm is deposited on the structure. The deposited dielectric material may be the same as the dielectric material included in the dielectric layers 102B1-102B2. The dielectric layers 102B1-102B3 may form the dielectric layer 102B of the optical connection device 102.

[0060] The present invention provides exemplary optical connection devices (e.g., optical connection device 102) having a multi-tip dielectric structure (e.g., multi-tip dielectric structure 102D) having a thickness of less than about 200 nm. Such exemplary optical connection devices can provide improved optical connection efficiency between the optical connection device and an optical fiber (e.g., optical fiber 106), thereby improving the optical connection efficiency between the optical fiber and a silicon waveguide (e.g., silicon waveguide 104) on a silicon photonic integrated circuit. The present invention also provides methods for manufacturing these exemplary optical connection devices, which have fewer and fewer complex processing steps compared to methods for manufacturing optical connection devices with single-tip dielectric structures without sacrificing device performance of the exemplary optical connection devices.

[0061] In some embodiments, an exemplary optical connection device may include a semiconductor tapered structure (e.g., semiconductor tapered structure 102C) and a multi-tip dielectric structure (e.g., multi-tip dielectric structure 102D). The semiconductor tapered structure and the multi-tip dielectric structure may be arranged in different horizontal planes from each other in the dielectric layer stack. In some embodiments, the multi-tip dielectric structure may include an array of SiN structures or other suitable dielectric layers. In some embodiments, each tip has a vertical dimension along the Z axis of less than about 200nm (e.g., about 90nm), and a horizontal dimension along the Y axis of greater than about 200nm (e.g., about 300nm to about 500nm). Other suitable sizes of the tips of the multi-tip dielectric structure are within the scope of the present invention.

[0062] Since the multi-tip dielectric structure has a thinner SiN layer than the SiN-based single-tip dielectric structure, the complexity and number of process steps involved in the manufacture of the exemplary optical connection device are reduced. In some embodiments, the multi-tip dielectric structure can be manufactured by one etching step. Unlike the manufacturing process of the SiN-based single-tip dielectric structure, the manufacturing process of the multi-tip dielectric structure may not require high-resolution mask alignment, complex processes, and nano-scale etching process control.

[0063] The multi-tip dielectric structure allows for greater flexibility in configuring the exemplary optical connection device to achieve different optical mode sizes to match optical fibers with different core sizes. By adjusting the size of the SiN structure and the spacing between the SiN structures, the different optical mode sizes can be optimized to achieve maximum connection efficiency with the optical fiber. In some embodiments, the exemplary optical connection device has a higher tolerance for misalignment between the optical fiber and the multi-tip dielectric structure for two polarization pairs compared to a single-tip dielectric structured optical connection device. For a misalignment of 0.5 μm between the optical fiber and the multi-tip dielectric structure, the optical loss is less than 1 dB.

[0064] In some embodiments, an optical system includes: a substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; and an optical connection device disposed between the optical fiber and the waveguide. The optical connection device is configured to optically connect the optical fiber to the waveguide. The optical connection device includes a dielectric layer disposed on the substrate, a semiconductor tapered structure disposed in a first horizontal plane within the dielectric layer, and a multi-tip dielectric structure disposed in a second horizontal plane within the dielectric layer. The first horizontal plane and the second horizontal plane are different from each other.

[0065] In some embodiments, an optical system includes: a substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; and an optical connection device disposed between the optical fiber and the waveguide. The optical connection device is configured to optically connect the optical fiber to the waveguide. The optical connection device includes a dielectric layer disposed on the substrate, a multi-tip semiconductor structure having an array of semiconductor layers disposed within the dielectric layer, and a semiconductor tapered structure disposed on and in physical contact with the multi-tip semiconductor structure.

[0066] In some embodiments, a method for manufacturing an optical connection device includes: forming a semiconductor tapered structure located on a silicon-on-insulator (SOI) substrate; depositing a first dielectric layer located on the semiconductor tapered structure; forming a multi-tip dielectric structure having an array of dielectric structures located on the first dielectric layer; and depositing a second dielectric layer located on the multi-tip dielectric structure. In some embodiments, an optical system includes: a substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; and an optical connection device disposed between the optical fiber and the waveguide and configured to optically connect the optical fiber to the waveguide, wherein the optical connection device includes a dielectric layer disposed on the substrate, a semiconductor tapered structure disposed in a first horizontal plane within the dielectric layer, and a multi-tip dielectric structure disposed in a second horizontal plane within the dielectric layer, and wherein the first horizontal plane and the second horizontal plane are different from each other. In some embodiments, the semiconductor tapered structure and the multi-tip dielectric structure are vertically displaced from each other by a portion of the dielectric layer. In some embodiments, the multi-tip dielectric structure overlaps the semiconductor tapered structure. In some embodiments, the multi-tip dielectric structure comprises a one-dimensional or two-dimensional array of dielectric structures disposed in the second horizontal plane within the dielectric layer. In some embodiments, the multi-tip dielectric structure comprises an array of tips in physical contact with the optical fiber. In some embodiments, the multi-tip dielectric structure comprises an array of dielectric structures having a silicon nitride material. In some embodiments, the multi-tip dielectric structure comprises an array of silicon nitride structures disposed in the second horizontal plane within the dielectric layer, and wherein each silicon nitride structure in the array of silicon nitride structures has a vertical dimension in the range of about 50 nm to about 200 nm. In some embodiments, the multi-tip dielectric structure comprises a dielectric material having a refractive index greater than the refractive index of the optical fiber and less than the refractive index of the semiconductor material comprising the tapered structure. In some embodiments, the multi-tip dielectric structure comprises a one-dimensional array of tips, and wherein adjacent tips in the one-dimensional array of tips have different horizontal dimensions from one another. In some embodiments, the multi-tip dielectric structure comprises a two-dimensional array of tips, and wherein the tips in each column of the two-dimensional array have dimensions equal to one another. In some embodiments, the multi-tip dielectric structure comprises a two-dimensional array of dielectric structures, and wherein a first row of the two-dimensional array has a first number of dielectric structures, a second row of the two-dimensional array has a second number of dielectric structures, the first number and the second number being different from each other. In some embodiments, a base of the semiconductor tapered structure is substantially aligned with a base of the multi-tip dielectric structure.

[0067] In some embodiments, an optical system includes: a substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; and an optical connection device disposed between the optical fiber and the waveguide and configured to optically connect the optical fiber to the waveguide, wherein the optical connection device includes a dielectric layer disposed on the substrate, a multi-tip semiconductor structure having an array of semiconductor layers disposed within the dielectric layer, and a semiconductor tapered structure disposed on the multi-tip semiconductor structure and in physical contact with the multi-tip semiconductor structure. In some embodiments, one of the semiconductor structures in the array of semiconductor structures and the semiconductor tapered structure are portions of a single semiconductor structure disposed within the dielectric layer. In some embodiments, the array of semiconductor structures and the semiconductor tapered structure include the same semiconductor material. In some embodiments, each side of the semiconductor structure of the array of semiconductor structures is in physical contact with the optical fiber.

[0068] In some embodiments, a method for manufacturing an optical connection device includes: forming a semiconductor tapered structure located on a silicon-on-insulator (SOI) substrate; depositing a first dielectric layer located on the semiconductor tapered structure; forming a multi-tip dielectric structure having an array of dielectric structures located on the first dielectric layer; and depositing a second dielectric layer located on the multi-tip dielectric structure. In some embodiments, forming the semiconductor tapered structure includes etching a silicon layer of the SOI substrate. In some embodiments, forming the multi-tip dielectric structure includes depositing a second dielectric layer located on the first dielectric layer, and wherein the first dielectric layer and the second dielectric layer are different from each other. In some embodiments, forming the multi-tip dielectric structure includes patterning and etching the second dielectric layer.

[0069] The features of several embodiments are summarized above so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art should understand that they can easily use the present disclosure as a basis for designing or modifying other processes and structures for performing the same or similar purposes and / or achieving the same or similar advantages as the present disclosure. Those skilled in the art should also be aware that such equivalent structures do not depart from the spirit and scope of the present disclosure, and various changes, substitutions and modifications can be made without departing from the spirit and scope of the present disclosure.

Claims

1. An optical system, comprising: substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; as well as an optical connector extending between said optical fiber and said waveguide, The optical connection device comprises a dielectric layer disposed on the substrate, a tapered structure disposed in the dielectric layer, and a multi-tip nitride structure disposed above the tapered structure in the dielectric layer. Wherein, the multi-tip nitride structure includes a two-dimensional array of nitride structures disposed in the dielectric layer.

2. The optical system according to claim 1, wherein: The tapered structure is isolated from the optical fiber by portions of the dielectric layer.

3. The optical system according to claim 1, wherein: The number of the nitride structures in a first row of the two-dimensional array is less than the number of the nitride structures in a second row of the two-dimensional array.

4. The optical system according to claim 1, wherein: The size of the nitride structures in the first column of the two-dimensional array is greater than the size of the nitride structures in the second column of the two-dimensional array.

5. An optical system comprising: substrate; a waveguide disposed on the substrate; an optical fiber optically connected to the waveguide; as well as an optical connection device, disposed between the optical fiber and the waveguide, The optical connection device comprises a dielectric layer disposed on the substrate, a multi-tip semiconductor structure having a semiconductor layer array disposed in the dielectric layer, and a semiconductor tapered structure disposed on and in contact with the multi-tip semiconductor structure. Wherein, the semiconductor layer array of the multi-tip semiconductor structure is a two-dimensional array.

6. The optical system according to claim 5, wherein: The semiconductor tapered structure is isolated from the optical fiber by portions of the dielectric layer.

7. A method for manufacturing an optical connection device, comprising: forming a semiconductor tapered structure on a silicon-on-insulator (SOI) substrate; depositing a first dielectric layer on the semiconductor tapered structure; forming a multi-tip dielectric structure having an array of dielectric structures on the first dielectric layer; as well as depositing a second dielectric layer on the multi-tip dielectric structure, Wherein, the array of the dielectric structures of the multi-tip dielectric structure is a two-dimensional array.

8. The method according to claim 7, wherein: Forming the semiconductor tapered structure includes etching a silicon layer of the silicon-on-insulator substrate.

9. The method according to claim 7, wherein: Forming the multi-tip dielectric structure includes depositing a second dielectric layer on the first dielectric layer, and wherein the first dielectric layer and the second dielectric layer are different from each other.

10. The method according to claim 9, wherein: Forming the multi-tip dielectric structure includes patterning and etching the second dielectric layer.

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