OPA antenna, manufacturing method thereof and OPA chip

Abstract

The invention discloses an OPA antenna and a manufacturing method thereof, and an OPA chip. The OPA antenna comprises a substrate; the dielectric layer is arranged on the substrate; the antenna structure is arranged on a dielectric layer and extends in the first direction, the antenna structure comprises a first antenna layer and a second antenna layer which are arranged in a spaced and stacked mode, and the orthographic projection of the center line, extending in the first direction, of the first antenna layer on the second antenna layer coincides with the center line, extending in the first direction, of the second antenna layer. At least one of the first antenna layer and the second antenna layer is provided with a fishbone-shaped structure, and the fishbone-shaped structure comprises antenna units which are periodically arranged in the first direction.

Description

Technical Field

[0001] The present disclosure relates to the field of laser radar technology, and in particular, to an OPA antenna and a manufacturing method thereof, and an OPA chip. Background Art

[0002] Optical Phased Arrays (OPA) technology uses modulation to generate a specific phase difference between array waveguides and realizes the deflection of the beam angle through beam synthesis. It is a flexible, fast and precise non-mechanical beam directional scanning technology with the characteristics of high resolution, strong anti-interference and high confidentiality. Since the optical phased array uses lasers working in the optical band as information carriers, it is not affected by traditional radio waves. In addition, the laser beam is narrow and not easy to be detected, and has good confidentiality. In addition, compared with the large-volume electrical phased array, the optical phased array can be integrated on a chip, which is small in size, light in weight, flexible and low in power consumption. These advantages make optical phased arrays very attractive in the fields of free space optical communications, light detection and ranging (LIDAR), image projection, laser radar and optical storage. Summary of the invention

[0003] Some embodiments of the present disclosure provide an OPA antenna, including:

[0004] substrate;

[0005] A dielectric layer, disposed on the substrate;

[0006] An antenna structure is arranged on a dielectric layer and extends along a first direction. The antenna structure includes: a first antenna layer and a second antenna layer that are stacked at intervals. The orthographic projection of a midline of the first antenna layer extending along the first direction on the second antenna layer coincides with the midline of the second antenna layer extending along the first direction. At least one of the first antenna layer and the second antenna layer has a fishbone structure, and the fishbone structure includes antenna units periodically arranged along the first direction.

[0007] In some embodiments, the first antenna layer and the second antenna layer are made of the same material and have basically the same fishbone structure. The first antenna layer has multiple first antenna units, and the second antenna layer has multiple second antenna units. The multiple first antenna units correspond one-to-one to the multiple second antenna units. The first antenna units and the second antenna units have the same pattern and the same period. The orthographic projection of the second antenna unit on the first antenna layer is offset by a predetermined distance in the first direction relative to its corresponding first antenna unit.

[0008] In some embodiments, the first antenna layer and the second antenna layer are made of silicon nitride, and the spacer layer between the first antenna layer and the second antenna layer is made of silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna:

[0009] L0, Lf, Lp, p, W, H1, H2, Gap

[0010] Among them, L0 represents the offset of the first antenna unit and its corresponding second antenna unit in the first direction; Lf represents the length of the unetched part in one period of the first antenna unit and the second antenna unit; Lp represents the length of the etched part in one period of the first antenna unit and the second antenna unit; W represents the width of the first antenna unit and the second antenna unit; p represents the etched width of the first antenna unit and the second antenna unit; H1 represents the thickness of the first antenna unit; H2 represents the thickness of the second antenna unit; Gap represents the spacing between the first antenna unit and the second antenna unit.

[0011] In some embodiments, the first antenna layer has a first fishbone structure, including a plurality of first antenna units periodically arranged along a first direction, and the second antenna layer has a strip structure arranged at intervals, including a plurality of second antenna units periodically arranged along the first direction, the plurality of first antenna units correspond one-to-one to the plurality of second antenna units, the first antenna unit and the second antenna unit have the same period, and the orthographic projection of the second antenna unit on the first antenna layer is offset by a predetermined distance in the first direction relative to its corresponding first antenna unit.

[0012] In some embodiments, the material of the first antenna layer is silicon, the material of the second antenna layer is polysilicon, and the material of the spacer layer between the first antenna layer and the second antenna layer is silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna:

[0013] L0, Lf, Lp, p, Tsi, Wsi, Tpoly, Wpoly, gap

[0014] Among them, L0 represents the offset of the first antenna unit and its corresponding second antenna unit in the first direction; Lf represents the length of the unetched part in one period of the first antenna unit and the length of the strip structure in one period of the second antenna unit; Lp represents the length of the etched part in one period of the first antenna unit and the length of the spacing area in one period of the second antenna unit; p represents the etching width of the first antenna unit; Tsi represents the thickness of the first antenna unit; Wsi represents the width of the first antenna unit; Tpoly represents the thickness of the second antenna unit; Wpoly represents the width of the second antenna unit; Gap represents the spacing between the first antenna unit and the second antenna unit.

[0015] In some embodiments, the first antenna layer has a continuous long strip structure extending along the first direction, and the second antenna layer has a second herringbone structure including a plurality of antenna units periodically arranged along the first direction.

[0016] In some embodiments, the first antenna layer is made of silicon, the second antenna layer is made of silicon nitride, and the spacer layer between the first antenna layer and the second antenna layer is made of silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna:

[0017] Lf, Lp, p, Tsi, Wsi, Tsn, Wsn, gap

[0018] Among them, Lf represents the length of the unetched part in one period of the second antenna unit; Lp represents the length of the etched part in one period of the second antenna unit; p represents the etching width of the second antenna unit; Tsi represents the thickness of the first antenna unit; Wsi represents the width of the first antenna unit; Tsn represents the thickness of the second antenna unit; Wsn represents the width of the second antenna unit; Gap represents the spacing between the first antenna unit and the second antenna unit.

[0019] Some embodiments of the present disclosure provide a method for manufacturing an OPA antenna, the manufacturing method comprising the following steps:

[0020] Providing a substrate, the substrate comprising a substrate, a dielectric layer and a transmission layer stacked in sequence;

[0021] forming a first antenna layer using the transmission layer;

[0022] forming a spacer layer on the first antenna layer;

[0023] A second antenna layer is formed on the spacer layer.

[0024] In some embodiments, forming a first antenna layer using the transmission layer comprises the following steps:

[0025] Thinning at least a portion of the transmission layer using photolithography and etching processes;

[0026] The thinned transmission layer is photoetched by photolithography and etching process to form a first antenna layer.

[0027] In some embodiments, forming a spacer layer on the first antenna layer comprises the following steps:

[0028] A spacer layer is grown on the first antenna layer and a planarization operation is performed on a top surface of the spacer layer.

[0029] In some embodiments, forming a second antenna layer on the spacer layer comprises the following steps:

[0030] growing a second antenna material layer on the spacer layer and performing a planarization operation on the top surface of the second antenna material layer;

[0031] The second antenna material layer is etched by photolithography and etching process to form a second antenna layer.

[0032] In some embodiments, after forming the second antenna layer on the spacer layer, the manufacturing method includes the following steps:

[0033] A dielectric layer is grown on the second antenna layer and a planarization operation is performed on the top surface of the dielectric layer.

[0034] The present disclosure provides an OPA chip, including:

[0035] Laser transmission components;

[0036] The OPA antenna described in the preceding embodiment or the OPA antenna manufactured using the manufacturing method described in the preceding embodiment, wherein the laser transmission component is disposed in the same layer as the first antenna layer, both of which are made of silicon, and the thickness of the laser transmission component is greater than the thickness of the first antenna layer; and

[0037] A gradient connection component is arranged between the laser transmission component and the first antenna layer, and is used to transmit laser light between the laser transmission component and the first antenna layer. The gradient connection component includes a first component and a second component arranged in sequence along a first direction. The boundary between the first component and the second component is inclined to the first direction. The thickness of the first component is equal to the thickness of the laser transmission component, and the thickness of the second component is equal to the thickness of the first antenna layer.

[0038] Compared with the related art, the above solution of the embodiment of the present disclosure has at least the following beneficial effects:

[0039] The present disclosure adopts a double-layered antenna structure, which can still improve the antenna transmission efficiency without separately providing a reflective metal layer, so that the antenna has higher directivity, that is, higher upward transmission efficiency.

[0040] Two antenna layers with basically the same structure are stacked in an offset manner, and the antenna transmission efficiency is improved by simulating the structural parameters;

[0041] The polysilicon strip structures that are staggered and stacked at intervals on the fishbone-shaped first antenna layer made of silicon can improve the dispersion of the antenna, making the antenna have a larger field of view. At the same time, the broadband direction of the antenna has strong constraints, and the distance between adjacent antennas in the antenna array can be reduced, thereby improving the overall transmission efficiency of the antenna array.

[0042] A second antenna layer in a fishbone shape made of silicon nitride is stacked on a strip structure made of silicon. The process is simple and the precision requirement is low. It can improve the dispersion of the antenna, so that the antenna has a larger field of view. At the same time, the broadband direction of the antenna has strong constraints. The distance between adjacent antennas in the antenna array can be reduced, thereby improving the overall transmission efficiency of the antenna array. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0044] Figure 1 A schematic diagram of the structure of an OPA chip provided in some embodiments of the present disclosure;

[0045] Figure 2 A schematic diagram of the structure of an OPA antenna provided in some embodiments of the present disclosure;

[0046] Figure 3 for Figure 2 A top view of the first antenna layer or the second antenna layer in the OPA antenna;

[0047] Figure 4 A schematic diagram of the structure of an OPA antenna provided in some embodiments of the present disclosure;

[0048] Figure 5 for Figure 4 A top view of the first antenna layer or the second antenna layer in the OPA antenna;

[0049] Figure 6 A schematic diagram of the structure of an OPA antenna provided in some embodiments of the present disclosure;

[0050] Figure 7 for Figure 6 A top view of the first antenna layer or the second antenna layer in the OPA antenna;

[0051] Figure 8 A schematic diagram of the structure of a substrate provided for some embodiments of the present disclosure; and

[0052] Fig. 9 A schematic diagram of the structure of a gradient connection component provided in some embodiments of the present disclosure. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0054] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments, and are not intended to limit the present disclosure. The singular forms "a", "said" and "the" used in the embodiments of the present disclosure and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0055] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0056] It should be understood that although the terms first, second, third, etc. may be used to describe in the present disclosure, these should not be limited to these terms. These terms are only used to distinguish. For example, without departing from the scope of the present disclosure, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0057] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such product or device. In the absence of more restrictions, the elements defined by the sentence "comprises a" do not exclude the presence of other identical elements in the product or device including the elements.

[0058] In the related technology, most of the current OPA chips use a single-layer 220nm silicon weak perturbation fishbone antenna, but the single-layer silicon fishbone has low transmission efficiency. Since the upper and lower sides of silicon are made of silicon dioxide, the light in the waveguide will radiate upward and downward symmetrically when it propagates to the grating perturbation. The light radiated downward is a loss, so the transmission efficiency of the antenna is less than 50%. In order to improve the transmission efficiency of the antenna, the related technology manufactures a metal reflective layer under the antenna to reflect the downward radiated light to improve the antenna transmission efficiency, but this solution requires an additional and more complex process flow.

[0059] The present disclosure provides an OPA antenna, comprising: a substrate; a dielectric layer, arranged on the substrate; an antenna structure, arranged on the dielectric layer and extending along a first direction, the antenna structure comprising: a first antenna layer and a second antenna layer, which are stacked at intervals, the orthographic projection of a midline of the first antenna layer extending along the first direction on the second antenna layer coincides with the midline of the second antenna layer extending along the first direction, at least one of the first antenna layer and the second antenna layer has a fishbone structure, and the fishbone structure comprises antenna units periodically arranged along the first direction.

[0060] The present disclosure adopts a double-layered antenna structure, which can still improve the antenna transmission efficiency without separately providing a reflective metal layer, so that the antenna has higher directivity, that is, higher upward transmission efficiency.

[0061] The optional embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0062] Figure 1 This is a schematic diagram of the structure of the OPA chip provided in some embodiments of the present disclosure. Figure 1 As shown, the OPA chip 1000 includes a substrate 100 and a transmitting component 200 and a receiving component 300 disposed on the substrate 100 .

[0063] The transmitting component 200 is disposed on the substrate 100 and configured to transmit a detection beam, and the detection beam is reflected after encountering an obstacle to generate a reflected beam. The receiving component 300 is disposed on the substrate 100 and configured to receive the reflected beam.

[0064] The transmitting component 200 and the receiving component 300 are arranged side by side, and the structures of the two are basically the same, both of which include an OPA antenna 10, referred to as the antenna 10, a phase modulator 20 and other components.

[0065] Multiple antennas 10 are arranged parallel to each other in the antenna area A10, and are used to transmit detection beams or receive reflected beams. Specifically, the multiple antennas 10 of the transmitting component 200 are also called transmitting antennas 210, which are used to transmit detection beams, and the multiple antennas 10 of the receiving component 300 have become receiving antennas 310, which are used to receive reflected beams reflected by obstacles.

[0066] The multiple phase modulators 20 are arranged side by side in the phase adjustment area A20, and are connected to the multiple antennas 10 through multiple transmission waveguides 30. Specifically, the multiple phase modulators of the transmitting component 200 are also called transmitting phase modulators 220, which are used to phase the multiple light beams transmitted to the multiple transmitting antennas 210. The multiple phase modulators of the receiving component 300 are also called receiving phase modulators 320, which are used to phase the multiple light beams output from the multiple transmitting antennas 210.

[0067] like Figure 1As shown, the transmitting component 200 includes a beam splitting component 240 , a plurality of transmitting phase modulators 220 , a plurality of transmitting antennas 210 , and a plurality of transmitting transmission waveguides 230 .

[0068] The beam splitting assembly 240, for example, a beam splitting network, may include one or more beam splitters configured to split the initial detection beam into multiple sub-detection beams. Multiple transmit phase modulators 220 receive the multiple sub-detection beams respectively and phase-modulate the multiple sub-detection beams respectively. Multiple transmit transmission waveguides 230 are respectively connected to the multiple transmit phase modulators 220 and the multiple transmit antennas 210, and transmit the multiple sub-detection beams after phase modulation respectively. The multiple transmit antennas 210 respectively transmit the multiple sub-detection beams after phase modulation, and the multiple sub-detection beams interfere to form the detection beam emitted along a preset direction, and the preset direction is determined based on the multiple transmit phase modulators and is adjustable.

[0069] like Figure 1 As shown, the receiving component 300 includes a plurality of receiving antennas 310 , a plurality of receiving transmission waveguides 330 , a plurality of receiving phase modulators 320 and a beam combining component 340 .

[0070] The multiple receiving antennas 310 receive the reflected light beams, which are planar light beams including multiple sub-reflected light beams, which are received by the multiple receiving antennas 310 respectively. The multiple receiving transmission waveguides 330 are respectively connected to the multiple receiving phase modulators 320 and the multiple receiving antennas 310, and transmit the multiple sub-reflected light beams respectively. The multiple receiving phase modulators 320 receive the multiple sub-reflected light beams respectively, and phase-modulate the multiple sub-reflected light beams so that the multiple sub-reflected light beams can be combined. The beam combining component 340, for example, is a beam combining network, which may include one or more beam combiners. The beam combining component 340 combines the multiple sub-reflected light beams after phase modulation into a test beam.

[0071] In some embodiments, Figure 1 As shown, the OPA chip 1000 also includes a receiver 510 and a spectrometer 520. The receiver 510 is, for example, an edge-coupled receiver configured to receive laser light. The spectrometer 520 is connected to the receiver 510, for example, by a waveguide. The spectrometer 520 splits the laser into an initial detection beam and a local oscillator beam Lo, and the modulation waveforms of the initial detection beam and the local oscillator beam Lo are exactly the same. The spectrometer 520 transmits the initial detection beam to the spectrometer component 240 of the transmitting component 200, for example, by a waveguide.

[0072] In some embodiments, the chip 1000 further includes a mixer 530 and a detector 540. The mixer 530 is connected to the beam splitter 520, for example, through a waveguide, and receives the local oscillator beam Lo output by the beam splitter 520. The mixer 530 is connected to the light combining component 340 of the receiving component 300, for example, through a waveguide, and receives the test beam formed by the reflected beam. The mixer 530 mixes the test beam formed by the reflected beam with the local oscillator beam Lo to generate a mixed beam.

[0073] Figure 2 A schematic diagram of the structure of an OPA antenna provided in some embodiments of the present disclosure, Figure 3 for Figure 2 A top view of the first antenna layer or the second antenna layer in the OPA antenna, such as Figure 2 and Figure 3 As shown, some embodiments of the present disclosure provide an OPA antenna 10, which includes a substrate 11, a dielectric layer 12 and an antenna structure 13.

[0074] The substrate 11 may be a part of the substrate 100 of the OPA chip 1000. The substrate 11 is, for example, a silicon substrate.

[0075] The dielectric layer 12 is disposed on the substrate 11 , and the material of the dielectric layer 12 is, for example, silicon dioxide.

[0076] The antenna structure 13 is arranged on the dielectric layer 12 and extends along the first direction X. The antenna structure 13 includes: a first antenna layer 131 and a second antenna layer 132 that are stacked at intervals. The orthographic projection of the midline of the first antenna layer 131 extending along the first direction X on the second antenna layer 132 coincides with the midline of the second antenna layer 132 extending along the first direction X. At least one of the first antenna layer 131 and the second antenna layer 132 has a fishbone structure, and the fishbone structure includes antenna units U periodically arranged along the first direction. In this embodiment, both the first antenna layer 131 and the second antenna layer 132 have a fishbone structure.

[0077] The double-layered antenna structure can improve the antenna transmission efficiency without separately setting a reflective metal layer, so that the antenna has a higher directivity, that is, a higher upward transmission efficiency. There is no need to set a reflective metal layer under the antenna layer, which reduces the process complexity.

[0078] In some embodiments, Figure 2 and Figure 3As described above, the first antenna layer 131 and the second antenna layer 132 are made of the same material, for example, both are made of silicon nitride, and have substantially the same fishbone structure. The first antenna layer 131 has a plurality of first antenna units U1, and the second antenna layer 132 has a plurality of second antenna units U2. The plurality of first antenna units U1 and the plurality of second antenna units U2 correspond one by one. The patterns of the first antenna unit U1 and the second antenna unit U2 are the same, and the periods are the same. The orthographic projection of the second antenna unit U2 on the first antenna layer U1 is offset by a predetermined distance in the first direction X relative to its corresponding first antenna unit U1.

[0079] In some embodiments, as Figure 2 and Figure 3 shown, the materials of the first antenna layer 131 and the second antenna layer 132 are silicon nitride, and the material of the spacer layer 14 between the first antenna layer 131 and the second antenna layer 132 is silicon dioxide. The following parameters are designed through simulation to improve the emission efficiency of the OPA antenna 11:

[0080] L0, Lf, Lp, p, W, H1, H2, Gap

[0081] Among them, L0 represents the offset of the first antenna unit U1 and its corresponding second antenna unit U2 in the first direction X; Lf represents the length of the unetched part in one period of the first antenna unit U1 and the second antenna unit U2; Lp represents the length of the etched part in one period of the first antenna unit U1 and the second antenna unit U2; W represents the width of the first antenna unit and the second antenna unit; p represents the etching width of the first antenna unit and the second antenna unit; H1 represents the thickness of the first antenna unit; H2 represents the thickness of the second antenna unit; Gap represents the distance between the first antenna unit and the second antenna unit.

[0082] In this embodiment, by designing L0, Lf, Lp, p, W, H1, H2, Gap through simulation to maximize the upward radiation of the OPA antenna 10 to improve the antenna emission efficiency, the antenna emission efficiency > 90% can be achieved. Compared with the related art, for the OPA antenna 10 with a double-layer fishbone grating structure, the grating teeth have an offset in the first direction X, that is, a slight offset of L0 (0 < L0 < antenna unit period) further breaks the symmetry in the vertical direction Z, and the light energy of the upward radiation can be maximized at a specific L0 value. There is no need to separately set a reflective metal layer under the antenna layer, and the process is simple.

[0083] Figure 4 It is a schematic structural diagram of an OPA antenna provided by some embodiments of the present disclosure. Figure 5 is Figure 5 the top view of the first antenna layer or the second antenna layer in the OPA antenna in Figure 4and Figure 5 As shown, in the OPA antenna 10' in this embodiment, the first antenna layer 131' has a first fishbone structure, including a plurality of first antenna units U1' periodically arranged along a first direction, and the second antenna layer 132' has a strip structure arranged at intervals, including a plurality of second antenna units U2' periodically arranged along the first direction, the plurality of first antenna units 131' corresponds to the plurality of second antenna units U2' one by one, the first antenna unit U1' and the second antenna unit U2' have the same period, and the orthographic projection of the second antenna unit U2' on the first antenna layer 131' is offset by a predetermined distance in the first direction relative to its corresponding first antenna unit U1'.

[0084] In some embodiments, the material of the first antenna layer 131' is silicon, the material of the second antenna layer 132' is polysilicon, and the material of the spacer layer 14 between the first antenna layer 131' and the second antenna layer 132' is silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna:

[0085] L0, Lf, Lp, p, Tsi, Wsi, Tpoly, Wpoly, gap

[0086] Among them, L0 represents the offset of the first antenna unit U1' and its corresponding second antenna unit U2' in the first direction; Lf represents the length of the unetched part in one period of the first antenna unit U1' and the length of the strip structure in one period of the second antenna unit U2'; Lp represents the length of the etched part in one period of the first antenna unit U1' and the length of the spacing area in one period of the second antenna unit U2'; p represents the etching width of the first antenna unit U1'; Tsi represents the thickness of the first antenna unit U1'; Wsi represents the width of the first antenna unit U1'; Tpoly represents the thickness of the second antenna unit U2'; Wpoly represents the width of the second antenna unit U2'; Gap represents the spacing between the first antenna unit U1' and the second antenna unit U2'.

[0087] In this embodiment, L0, Lf, Lp, p, Tsi, Wsi, Tpoly, Wpoly, gap are selected through simulation design to maximize the upward radiation to improve the antenna transmission efficiency. Through simulation, the antenna transmission efficiency can be achieved to be >80%.

[0088] In this embodiment, the first antenna layer made of silicon in a fishbone shape is stacked with the second antenna layer made of polysilicon in a discontinuous strip shape, so that the overall refractive index of the antenna is higher and has stronger dispersion. Since the wavelength adjustment range of the tunable laser is limited, stronger dispersion means that the antenna has a larger field of view. In addition, the double-layer structure in this embodiment also breaks the symmetry in the vertical direction Z by periodically shifting the first antenna unit and the second antenna unit in the first direction, and can maximize the light energy radiated upward at a specific L0 value.

[0089] In addition, in this embodiment, since the first antenna layer is made of silicon and the second antenna layer is made of polycrystalline silicon, the antenna has stronger constraints in the second direction Y, that is, the spacing between adjacent antennas in the antenna array can be set smaller, so that the number of side lobes of the antenna array is reduced, the main lobe energy is increased, and the overall efficiency of the antenna array is improved.

[0090] Figure 6 A schematic diagram of the structure of an OPA antenna provided in some embodiments of the present disclosure, Figure 7 for Figure 6 A top view of the first antenna layer or the second antenna layer in the OPA antenna, such as Figure 6 and Figure 7 As shown, in the OPA antenna 10" in this embodiment, the first antenna layer 131" has a continuous long strip structure extending along the first direction X, and the second antenna layer 132" has a second herringbone structure, including a plurality of antenna units U" periodically arranged along the first direction X.

[0091] In some further embodiments, the material of the first antenna layer 131 ″ is silicon, the material of the second antenna layer 132 ″ is silicon nitride, and the material of the spacer layer 14 between the first antenna layer 131 ″ and the second antenna layer 132 ″ is silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna:

[0092] Lf, Lp, p, Tsi, Wsi, Tsn, Wsn, gap

[0093] Among them, Lf represents the length of the unetched part in one period of the second antenna unit; Lp represents the length of the etched part in one period of the second antenna unit; p represents the etching width of the second antenna unit; Tsi represents the thickness of the first antenna unit; Wsi represents the width of the first antenna unit; Tsn represents the thickness of the second antenna unit; Wsn represents the width of the second antenna unit; Gap represents the spacing between the first antenna unit and the second antenna unit.

[0094] In this embodiment, Lf, Lp, p, Tsi, Wsi, Tsn, Wsn, gap are selected through simulation design to maximize the upward radiation to improve the antenna transmission efficiency. Through simulation, the antenna transmission efficiency can be achieved> 70%

[0095] In the present embodiment, since a first antenna layer made of continuous long strips of silicon is stacked on a second antenna layer antenna made of fishbone-shaped polycrystalline silicon, the overall refractive index of the antenna is higher and has stronger dispersion, that is, the antenna has a larger field of view angle; at the same time, since the high refractive index light energy of the silicon waveguide is mainly confined within the silicon waveguide, the antenna has a stronger constraint in the second direction Y, and the spacing between adjacent antennas in the antenna array is smaller, so that the number of side lobes of the antenna array is reduced, the main lobe energy is increased, and the overall efficiency of the antenna array is improved.

[0096] Since the light energy in this embodiment is mainly confined in the silicon waveguide, the silicon nitride grating is easier to achieve weak perturbation, that is, the required minimum process dimension (CD) is larger and easier to manufacture.

[0097] Some embodiments of the present disclosure provide a method for manufacturing an OPA antenna, the manufacturing method comprising the following steps:

[0098] S10 provides a substrate, wherein the substrate includes a substrate, a dielectric layer, and a transmission layer stacked in sequence.

[0099] In this field, the OPA antenna and the OPA chip in which it is located are usually manufactured together using semiconductor processes. In order to improve manufacturing efficiency, silicon substrates purchased from other manufacturers are usually directly used as raw materials for processing. The silicon substrate is the substrate. Figure 8 Schematic diagram of the structure of the substrate provided in some embodiments of the present disclosure. Figure 8 As shown, the substrate 1 includes a substrate 1-1, a dielectric layer 1-2 and a transmission layer 1-3. In some embodiments, the substrate 1-1 is generally a silicon substrate, the dielectric layer 1-2 is such as a silicon dioxide layer, and the thickness is, for example, 2μm to 3μm, and the transmission layer 1-3 is such as a silicon layer, and the thickness is, for example, 220nm to 500nm. At least a portion of the substrate 1-1 in the substrate 1 can be used as the substrate 11 of the OPA antenna 10, and at least a portion of the dielectric layer 1-2 in the substrate 1 can be used as the dielectric layer 12 of the OPA antenna 10. At least a portion of the transmission layer 1-3, such as a silicon layer, is used to form a material layer of the first antenna layer. In other embodiments, at least a portion of the transmission layer 1-3 can be removed and replaced with other materials to form the first antenna layer. For example, in Figure 2In the corresponding embodiment, the first antenna layer 131 uses silicon nitride instead of silicon, and photolithography and etching processes can be used to remove at least a portion of the transmission layer 1-3 to expose the dielectric layer 1-2, so as to facilitate the subsequent growth of a first antenna layer 131 material layer on the exposed dielectric layer 1-2, and then use semiconductor processes to form the first antenna layer 131.

[0100] S20: Forming a first antenna layer using the transmission layer.

[0101] When the material of the first antenna layer of the OPA antenna is silicon, for example Figure 4 , Figure 6 In the corresponding embodiment, the transmission layers 1 to 3 may be directly used as the material layers for forming the first antenna layer, and the first antenna layer 131 ′, 131 ″ may be formed by using semiconductor technology.

[0102] S30: forming a spacer layer on the first antenna layer.

[0103] A spacer layer 14 is formed on the first antenna layer. The spacer layer 14 is made of, for example, silicon dioxide. Specifically, the spacer layer 14 is formed on the first antenna layer by growth or deposition, and planarization is performed on the spacer layer, for example, by using a CMP (chemical mechanical polishing) process.

[0104] S40: forming a second antenna layer on the spacer layer.

[0105] Specifically, the second antenna layers 132 , 132 ′, and 132 ″ are formed on the spacer layer 14 by using a semiconductor process.

[0106] In some embodiments, for example Figure 4 In a corresponding embodiment, forming the first antenna layer by using the transmission layer comprises the following steps:

[0107] S21: thinning at least a portion of the transmission layer using photolithography and etching processes.

[0108] Figure 4 In the corresponding embodiment, the thickness of the first antenna layer 132' is selected to be 140nm to 160nm through simulation. It is necessary to perform a thinning operation on the transmission layer 1-3 with a thickness of 220nm to 300nm, for example, the thinning process of the transmission layer 1-3 can be performed by photolithography and etching processes. In other embodiments, the thinning process can also be performed by CMP (chemical mechanical polishing) process.

[0109] S22: Photolithography and etching are performed on the thinned transmission layer using a photolithography and etching process to form a first antenna layer.

[0110] Specifically, refer to Figures 4 to 5As shown, the thinned transmission layer 1-3 may be patterned by using photolithography and etching processes to form a herringbone-shaped first antenna layer 131'.

[0111] In other embodiments, for example Figure 6 In the corresponding embodiment, the thickness of the first antenna layer 132' is selected to be 220nm-300nm through simulation, and the transmission layers 1-3 can be directly patterned through photolithography and etching processes to form a continuous strip-shaped first antenna layer 131".

[0112] In some embodiments, forming a spacer layer on the first antenna layer comprises the following steps:

[0113] A spacer layer is grown on the first antenna layer and a planarization operation is performed on a top surface of the spacer layer.

[0114] Specifically, refer to Figure 2 , Figure 4 In the corresponding embodiment of 6, a silicon dioxide material is grown on the first antenna layer 131, 131', 131" to form the spacer layer 14. The spacer layer 14 can also be formed by depositing silicon dioxide, and a planarization operation is performed on the spacer layer, for example, by using a CMP (chemical mechanical polishing) process.

[0115] In some embodiments, forming a second antenna layer on the spacer layer comprises the following steps:

[0116] S41: growing a second antenna material layer on the spacer layer and performing a planarization operation on a top surface of the second antenna material layer.

[0117] Specifically, refer to Figure 2 , Figure 4 And in the embodiment corresponding to step 6, a second antenna material layer is grown on the spacer layer 14, and then a top surface of the second antenna material layer is planarized by, for example, a CMP (chemical mechanical polishing) process.

[0118] S42: etching the second antenna material layer using photolithography and etching processes to form a second antenna layer.

[0119] Specifically, refer to Figure 2 , Figure 4 In the corresponding embodiment of 6, the second antenna material is patterned by photolithography and etching processes to form a second antenna layer 132, 132', 132" with a specific shape.

[0120] In some embodiments, after forming a second antenna layer on the spacer layer, the manufacturing method includes the following steps:

[0121] S50: growing a dielectric layer on the second antenna layer and performing a planarization operation on a top surface of the dielectric layer.

[0122] Specifically, refer to Figure 2 , Figure 4 And in the embodiment corresponding to step 6, a dielectric layer 15 is grown on the second antenna layer, the material of the dielectric layer 15 is, for example, silicon dioxide, and a planarization operation is performed on the top surface of the dielectric layer 15. The dielectric layer 15 is used to protect the internal structure of the OPA antenna.

[0123] Some embodiments of the present disclosure also provide an OPA chip 1000, including: a laser transmission component, an OPA antenna and a gradient connection component.

[0124] In this field, the OPA antenna and the OPA chip in which it is located are usually manufactured together using semiconductor processes. In order to improve manufacturing efficiency, silicon substrates purchased from other manufacturers, i.e. substrates, are usually used as raw materials for processing. The thicknesses of the substrate 1-1, dielectric layer 1-2, and transmission layer 1-3 of the purchased substrate are determined. For example, the dielectric layer 1-2, such as a silicon dioxide layer, has a thickness of 2μm to 3μm, and the transmission layer 1-3, such as a silicon layer, has a thickness of 220nm to 500nm. The thickness of the transmission layer 1-3 can usually meet the signal transmission requirements of most components on the OPA chip, and can be directly used to form most components using semiconductor processes as laser transmission components. However, in Figure 4 In the corresponding embodiment, the first antenna layer 131' formed by using the transmission layers 1-3 needs to be thinned to manufacture the first antenna layer 131' of 140-160nm. On the overall OPA chip, the laser signal cannot be directly transmitted from the thicker laser transmission component to the thinner first antenna layer 131', so the gradient connection component 40 is designed in this embodiment. Fig. 9 A schematic diagram of the structure of a gradient connection component provided in some embodiments of the present disclosure.

[0125] Laser transmission components such as Figure 1 The components such as the phase modulator 20 on the OPA chip shown in the figure have a thickness of, for example, 220 nm.

[0126] OPA antenna uses Figure 4 In the corresponding OPA antenna 10' of the embodiment, the laser transmission component is arranged on the same layer as the first antenna layer 131' of the OPA antenna 10', and the material thereof is silicon. The thickness of the laser transmission component is greater than the thickness of the first antenna layer. The thickness of the first antenna layer 131' is, for example, 150 nm.

[0127] The gradient connection component 40 is disposed between the laser transmission component and the first antenna layer 131', and is used to transmit laser light between the laser transmission component and the first antenna layer. The gradient connection component 40 includes a first component 41 and a second component 42 sequentially disposed along a first direction X. The boundary between the first component 41 and the second component 42 is inclined to the first direction X. The thickness of the first component 41 is equal to the thickness of the laser transmission component, for example, 220 nm. The thickness of the second component is equal to the thickness of the first antenna layer 131', for example, 150 nm. The gradient connection component 40 can transmit laser light between the laser transmission component and the first antenna layer of different thicknesses substantially without loss.

[0128] The various parts in this manual are described in a combination of parallel and progressive ways. Each part focuses on the differences from other parts, and the same or similar parts between the various parts can be referenced to each other.

[0129] With respect to the above description of the disclosed embodiments, the features described in the embodiments in this specification may be replaced or combined with each other, so that professionals in the field can implement or use the present application. Various modifications to these embodiments will be apparent to professionals in the field, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0130] Finally, it should be noted that: each embodiment in this specification is described by way of example, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0131] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. An OPA antenna, characterized in that: include: substrate; A dielectric layer, disposed on the substrate; An antenna structure is arranged on a dielectric layer and extends along a first direction. The antenna structure includes: a first antenna layer and a second antenna layer that are stacked at intervals. The orthographic projection of a midline of the first antenna layer extending along the first direction on the second antenna layer coincides with the midline of the second antenna layer extending along the first direction. At least one of the first antenna layer and the second antenna layer has a fishbone structure, and the fishbone structure includes antenna units periodically arranged along the first direction.

2. The OPA antenna according to claim 1, characterized in that: The first antenna layer and the second antenna layer are made of the same material and have basically the same fishbone structure. The first antenna layer has multiple first antenna units, and the second antenna layer has multiple second antenna units. The multiple first antenna units correspond one-to-one to the multiple second antenna units. The first antenna unit and the second antenna unit have the same pattern and the same period. The orthographic projection of the second antenna unit on the first antenna layer is offset by a predetermined distance in the first direction relative to its corresponding first antenna unit.

3. The OPA antenna according to claim 2, characterized in that: The materials of the first antenna layer and the second antenna layer are silicon nitride, and the material of the spacer layer between the first antenna layer and the second antenna layer is silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna: L0, Lf, Lp, p, W, H1, H2, Gap Among them, L0 represents the offset of the first antenna unit and its corresponding second antenna unit in the first direction; Lf represents the length of the unetched part in one period of the first antenna unit and the second antenna unit; Lp represents the length of the etched part in one period of the first antenna unit and the second antenna unit; W represents the width of the first antenna unit and the second antenna unit; p represents the etched width of the first antenna unit and the second antenna unit; H1 represents the thickness of the first antenna unit; H2 represents the thickness of the second antenna unit; Gap represents the spacing between the first antenna unit and the second antenna unit.

4. The OPA antenna according to claim 1, characterized in that: The first antenna layer has a first fishbone structure, including a plurality of first antenna units periodically arranged along a first direction, and the second antenna layer has a strip structure arranged at intervals, including a plurality of second antenna units periodically arranged along the first direction, the plurality of first antenna units correspond one to one with the plurality of second antenna units, the first antenna unit and the second antenna unit have the same period, and the orthographic projection of the second antenna unit on the first antenna layer is offset by a predetermined distance in the first direction relative to its corresponding first antenna unit.

5. The OPA antenna according to claim 4, characterized in that: The material of the first antenna layer is silicon, the material of the second antenna layer is polysilicon, and the material of the spacer layer between the first antenna layer and the second antenna layer is silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna: L0, Lf, Lp, p, Tsi, Wsi, Tpoly, Wpoly, gap Among them, L0 represents the offset of the first antenna unit and its corresponding second antenna unit in the first direction; Lf represents the length of the unetched part in one period of the first antenna unit and the length of the strip structure in one period of the second antenna unit; Lp represents the length of the etched part in one period of the first antenna unit and the length of the spacing area in one period of the second antenna unit; p represents the etching width of the first antenna unit; Tsi represents the thickness of the first antenna unit; Wsi represents the width of the first antenna unit; Tpoly represents the thickness of the second antenna unit; Wpoly represents the width of the second antenna unit; Gap represents the spacing between the first antenna unit and the second antenna unit.

6. The OPA antenna according to claim 1, characterized in that: The first antenna layer has a continuous long strip structure extending along the first direction, and the second antenna layer has a second herringbone structure including a plurality of antenna units periodically arranged along the first direction.

7. The OPA antenna according to claim 6, characterized in that: The material of the first antenna layer is silicon, the material of the second antenna layer is silicon nitride, and the material of the spacer layer between the first antenna layer and the second antenna layer is silicon dioxide. The following parameters are simulated and designed to improve the transmission efficiency of the OPA antenna: Lf, Lp, p, Tsi, Wsi, Tsn, Wsn, gap Among them, Lf represents the length of the unetched part in one period of the second antenna unit; Lp represents the length of the etched part in one period of the second antenna unit; p represents the etching width of the second antenna unit; Tsi represents the thickness of the first antenna unit; Wsi represents the width of the first antenna unit; Tsn represents the thickness of the second antenna unit; Wsn represents the width of the second antenna unit; Gap represents the spacing between the first antenna unit and the second antenna unit.

8. A method for manufacturing an OPA antenna, characterized in that: The manufacturing method comprises the following steps: Providing a substrate, the substrate comprising a substrate, a dielectric layer and a transmission layer stacked in sequence; forming a first antenna layer using the transmission layer; forming a spacer layer on the first antenna layer; A second antenna layer is formed on the spacer layer.

9. The method for manufacturing an OPA antenna according to claim 8, characterized in that: The forming of the first antenna layer by using the transmission layer comprises the following steps: Thinning at least a portion of the transmission layer using photolithography and etching processes; The thinned transmission layer is photoetched by photolithography and etching process to form a first antenna layer.

10. An OPA chip, characterized in that: include: Laser transmission components; The OPA antenna of any one of claims 1 to 7 or the OPA antenna manufactured by the manufacturing method of any one of claims 8 to 12, wherein the laser transmission component is arranged in the same layer as the first antenna layer, and the material thereof is silicon, and the thickness of the laser transmission component is greater than the thickness of the first antenna layer; as well as A gradient connection component is arranged between the laser transmission component and the first antenna layer, and is used to transmit laser light between the laser transmission component and the first antenna layer. The gradient connection component includes a first component and a second component arranged in sequence along a first direction. The boundary between the first component and the second component is inclined to the first direction. The thickness of the first component is equal to the thickness of the laser transmission component, and the thickness of the second component is equal to the thickness of the first antenna layer.

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