Acoustic chip and method of manufacturing the same

Abstract

The present disclosure provides an acoustic chip and a method of manufacturing an acoustic chip. The acoustic chip includes: a substrate; an acoustic device disposed on a substrate includes an acoustic core layer and an acoustic cladding at least partially surrounding an outer periphery of the acoustic core layer, where the acoustic cladding and the acoustic core layer have different acoustic velocities so as to at least partially localize acoustic waves within the acoustic core layer in the acoustic device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of integrated acoustic chip, and in particular, to an acoustic chip and a method for manufacturing an acoustic chip. BACKGROUND

[0002] With the development of piezoelectric thin film material preparation process, high-quality acoustic thin film material has been able to be made by using related technologies. Based on this, in the integrated acoustic waveguide, the acoustic wave can be transmitted along the acoustic waveguide of a specific line. However, the quality of the acoustic wave transmitted in the integrated acoustic waveguide is poor. SUMMARY

[0003] In view of the above problems, the present disclosure provides an acoustic chip and a method for manufacturing an acoustic chip.

[0004] According to a first aspect of the present disclosure, an acoustic chip is provided, the acoustic chip comprising: a substrate; an acoustic device disposed on the substrate, comprising an acoustic core layer and an acoustic cladding layer at least partially surrounding an outer periphery of the acoustic core layer, wherein the acoustic cladding layer has a different acoustic velocity from the acoustic core layer, so as to at least partially localize an acoustic wave in the acoustic core layer in the acoustic device.

[0005] According to a second aspect of the present disclosure, a method for manufacturing an acoustic chip is provided, the method comprising: forming an acoustic waveguide layer on a substrate; patterning the acoustic waveguide layer to obtain an acoustic core layer, the acoustic core layer being configured to modulate an acoustic propagation parameter of an acoustic wave propagating therein based on a structure of the acoustic core layer; forming an acoustic cladding layer, the acoustic cladding layer at least partially surrounding an outer periphery of the acoustic core layer, the acoustic cladding layer having a different acoustic velocity from the acoustic core layer, so as to at least partially localize the acoustic wave in the acoustic core layer.

[0006] According to an embodiment of the present disclosure, by disposing the acoustic cladding layer at the outer periphery of the acoustic core layer, since the acoustic cladding layer has a different acoustic velocity from the acoustic core layer, the acoustic cladding layer can confine the acoustic wave to be transmitted in the acoustic core layer, thereby improving the transmission quality of the acoustic wave and reducing the transmission loss of the acoustic wave. At the same time, the acoustic cladding layer can at least partially reduce the influence of external physical fields (such as at least one of the physical fields such as acoustic field, force field or thermal field) on the acoustic wave, thereby further improving the transmission quality of the acoustic wave. BRIEF DESCRIPTION OF DRAWINGS

[0007] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which:

[0008] Figure 1A A structural diagram of an acoustic chip according to an embodiment of the present disclosure is schematically shown.

[0009] Figure 1AA schematic diagram of the structure of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0010] Figure 1B A schematic diagram of the structure of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0011] Figure 1B A schematic diagram of the structure of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0012] Figure 1C A schematic diagram of the structure of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0013] Figure 1C A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0014] Figure 2A A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0015] Figure 2B A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0016] Figure 3 The schematic diagram illustrates a waveguide gate structure in an acoustic chip according to yet another embodiment of the present disclosure.

[0017] Figure 4 The schematic diagram illustrates a waveguide gate structure in an acoustic chip according to yet another embodiment of the present disclosure.

[0018] Figure 5 A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0019] Figure 6 A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0020] Figure 7 A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0021] Figure 8 A flowchart illustrating a method for manufacturing an acoustic chip according to an embodiment of the present disclosure is shown schematically. Detailed Implementation

[0022] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0024] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0025] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0026] Due to the low propagation speed and low frequency characteristics of sound waves, they possess unique advantages over electromagnetic waves in information processing. Integrated acoustic devices are widely used in signal processing due to their low cost, small size, and low power consumption. For example, surface acoustic wave (SAW) devices and bulk acoustic wave (SAW) filters are widely used in mobile communication devices. Compared to the localization of bulk acoustic waves, SAWs can propagate on the surface of a chip, offering greater controllability. SAW devices also have advantages such as simple structure and ease of fabrication. However, because sound waves lack good lateral confinement during propagation, SAW devices have weak control over sound waves, making it difficult to construct complex acoustic devices.

[0027] Integrated acoustic chips can utilize physical fields such as electric, magnetic, or thermal fields to control acoustic circuits. For large-scale integrated acoustic circuits, a large number of control devices need to be fabricated on the chip, requiring complex conductive wiring. However, if the conductive wiring is in direct contact with the acoustic waveguide, it will affect the quality of acoustic transmission.

[0028] To address the aforementioned issues, this invention provides an acoustic cladding layer around the acoustic core layer. This confines the propagating sound waves within the acoustic core layer, isolating it from the external environment and preventing the application of external physical fields from affecting the sound waves propagating within the acoustic core layer. This improves the transmission efficiency of the sound waves and reduces their transmission loss.

[0029] Figure 9 A schematic diagram of the structure of an acoustic chip according to an embodiment of the present disclosure is shown.

[0030] like Figure 10 As shown, the acoustic chip can be a non-suspended design. For example, the acoustic chip may include a substrate 110 and acoustic devices disposed on the substrate 110.

[0031] The substrate 110 can support the acoustic device to achieve a non-suspended design of the acoustic chip. Furthermore, the sound velocity of the substrate 110 can be different from the sound velocity of the acoustic device, thus at least partially localizing the transmitted sound waves within the acoustic chip. However, this disclosure is not limited to this; in other embodiments, the sound velocity of the substrate 110 can be the same as the sound velocity of the acoustic device, and this disclosure is not limited thereto. For example, the material of the substrate 110 can be, but is not limited to, at least one of silicon, gallium arsenide, sapphire, or silicon carbide.

[0032] The acoustic device may include an acoustic core layer 120 and an acoustic cladding layer 130. The acoustic core layer 120 can be used to transmit sound waves. However, the embodiments disclosed herein are not limited to this. In specific embodiments, the sound waves transmitted within the acoustic core layer 120 can be modulated. For example, the acoustic core layer 120 can modulate the acoustic propagation parameters of the sound waves propagating therein based on its own structure. However, it is not limited to this; in other embodiments, the sound waves transmitted within the acoustic core layer 120 can also be modulated by a physical field. For example, the acoustic core layer 120 can be designed with different structures according to requirements, and based on its own structure, it can guide and control the sound waves propagating therein, causing the sound waves to propagate and evolve along specific lines and structures, while simultaneously modulating at least one of the propagation parameters of the sound waves, such as phase, amplitude, or frequency. For example, the acoustic core layer 120 may be, but is not limited to, at least one of materials such as lithium niobate, zinc oxide, or diamond.

[0033] In an acoustic device, an acoustic cladding 130 may at least partially surround the outer periphery of an acoustic core layer 120. Specifically, the acoustic cladding 130 may be in contact with the sidewalls of the acoustic core layer 120, or the top surface of the acoustic core layer 120, or both the top surface and sidewalls of the acoustic core layer 120; this disclosure does not limit this. Based on this, the acoustic cladding 130 has a different sound velocity than the acoustic core layer 120, thereby at least partially localizing the sound wave within the acoustic core layer 120, thus improving the transmission quality of the sound wave. For example, the sound velocity of the acoustic cladding 130 may be greater than the sound velocity of the acoustic core layer 120, or the sound velocity of the acoustic cladding 130 may be less than the sound velocity of the acoustic core layer 120. In some embodiments, the greater the difference between the sound velocity of the acoustic cladding 130 and the sound velocity of the acoustic core layer 120, the better the confinement effect of the acoustic cladding 130 on sound waves may be. For example, the acoustic cladding 130 may include at least one of a solid cladding and a gaseous cladding. The solid cladding may include at least one of materials such as silicon nitride or aluminum nitride. The gaseous cladding is preferably a gas whose wave velocity is not easily matched with that of the acoustic core layer, such as an inert gas. For example, the gaseous cladding may include at least one of gases such as helium, neon, or argon. It should be noted that the materials of the solid cladding and the gaseous cladding described above are only examples. In other embodiments, other materials may be used as the acoustic cladding 130, which will not be elaborated here.

[0034] Based on this, by providing an acoustic cladding 130 around the acoustic core layer 120, the acoustic cladding 130 can confine sound waves within the acoustic core layer 120 due to the different sound speeds of the two layers, thus improving the transmission quality and reducing transmission loss. Simultaneously, the acoustic cladding 130 can at least partially reduce the influence of external physical fields (such as at least one of sound, force, or thermal fields) on the sound waves, thereby further improving the transmission quality.

[0035] also, Figure 11 A schematic diagram of the structure of an acoustic chip according to yet another embodiment of this disclosure is shown. Figure 1A As shown, in this embodiment of the acoustic chip, the substrate 110 and the cladding 130 can be made of the same material, so that the substrate 110 and the cladding 130 can form an integral structure to surround the acoustic core layer 120, thereby achieving confinement of the sound waves transmitted in the acoustic core layer 120. Furthermore, this disclosure is not limited to this embodiment. Figure 1A A schematic diagram of the structure of an acoustic chip according to yet another embodiment of this disclosure is shown. Figure 1BAs shown, in other embodiments of this disclosure, the acoustic core layer 120 may be recessed within the substrate, the substrate 110 is in contact with the sidewalls and bottom surface of the acoustic core layer 120, and the acoustic cladding layer 130 is in contact with the top surface of the acoustic core layer 120, so that the acoustic cladding layer 130 constrains the sound waves transmitted in the acoustic core layer 120.

[0036] Based on this, the acoustic cladding 130 can at least partially isolate the external physical field from the acoustic core layer 120, and can further confine the sound waves to propagate within the acoustic core layer 120, avoiding interference from the external physical field to the acoustic chip. It should be noted that the external physical field described herein can be provided by a physical field source independent of the acoustic chip, or it can be provided by a physical field source integrated on the acoustic chip; this disclosure does not impose any limitations on this.

[0037] For example, in this disclosure, the acoustic chip may also include a physical field source. This physical field source is physically spaced apart from the acoustic core layer 120. For example, the physical field source may include conductive wiring. The conductive wiring may provide a modulation field to the acoustic core layer to modulate sound waves. For example, the conductive wiring may extend within the acoustic cladding 130 and / or extend on the surface of the acoustic cladding 130. Specifically, the following... Figure 1B and Figure 1C To explain, Figure 1C A schematic diagram of the structure of an acoustic chip according to yet another embodiment of the present disclosure is shown. Figure 2A A schematic diagram of the structure of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0038] like Figure 2B As shown, the acoustic cladding 130 is a solid cladding. The acoustic cladding 130 may surround the top surface and sidewalls of the acoustic core layer 120. Thus, the conductive wiring 140 may provide a physical field to the conductive wiring 140 at intervals of the acoustic cladding 130 to modulate sound waves. Figure 2A In the example shown, the conductive wiring 140 can extend both inside and on the surface of the acoustic cladding 130. For example, a window can be created in the acoustic cladding 130 of the acoustic chip using a deep etching process, and then metal material can be deposited into the window to form the conductive wiring 140, thereby allowing the conductive wiring 140 to extend inside the acoustic cladding 130. Subsequently, the conductive wiring 140 extending on the surface of the acoustic cladding 130 can be formed on the top surface of the acoustic cladding 130 to enable interconnection between electrical devices on the surface and inside the acoustic cladding 130.

[0039] Furthermore, the embodiments disclosed herein are not limited thereto, such as... Figure 2BAs shown, in another embodiment of this disclosure, the conductive wiring 140 extends only on the surface of the acoustic cladding 130. This conductive wiring 140 can also provide a modulation field to the acoustic core layer 120 to modulate sound waves. For example, the conductive wiring 140 can be formed directly on the top surface of the acoustic cladding 130 using processes such as atomic layer deposition. It should also be noted that in other embodiments of this disclosure, the conductive wiring 140 may also be formed only inside the acoustic cladding 130, which will not be elaborated here.

[0040] Thus, the physical field source can be controlled using external physical field sources such as electric, magnetic, or thermal fields. Specifically, an external physical field can be applied by conductive wiring 140 extending inside and / or on the surface of the acoustic cladding 130, thereby enabling the control of the acoustic chip using an external physical field source. The acoustic cladding 130 isolates the acoustic core layer 120 and the conductive wiring 140, preventing unnecessary influence of external physical field sources on the acoustic chip. It should be noted that this is merely an example in this disclosure; in addition to conductive wiring, the physical field source in this application may also include thermal field sources, magnetic field sources, and other physical field sources.

[0041] Figure 2A A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0042] like Figure 2A As shown, the acoustic device in this embodiment can be an acoustic multimode interferometer. In this acoustic device, the acoustic core layer 120 includes at least one first port structure 1201, a multimode interference structure 1202, and at least one second port structure 1203 connected in sequence. The at least one first port structure 1201 can be used to input sound waves, so that the sound waves can be transmitted to the multimode interference structure 1202. The multimode interference structure 1202 can cause interference of multiple eigenmodes contained in the sound waves, thereby generating sound waves with multiple transmission modes during the transmission of the sound waves within the multimode interference structure. Subsequently, the output sound waves are transmitted to the at least one second port structure 1203. The at least one second port structure 1203 can output sound waves with an acoustic mode field distribution obtained due to interference.

[0043] Based on this, the input sound wave is input through the first port structure 1201. At the interface between the first port structure 1201 and the multimode interference structure 1202, the mode field of the input sound wave is decomposed into a combination of different sound wave modes. Since different sound wave modes propagate at different speeds in the multimode interference structure 1202, different sound wave modes will form different interference patterns in the multimode interference structure 1202. By designing a suitable multimode interference structure 1202, a specific sound wave mode distribution can be output through the second port structure 1203.

[0044] For example, the number of at least one second port structure 1203 can be greater than or equal to the number of at least one first port structure 1201. Based on this, Figure 2B A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0045] like Figure 3 As shown, the acoustic chip in this embodiment can be designed as a first port structure 1201 and two second port structures 1202. After the sound wave is input into the acoustic chip, it is transmitted to the multimode interference structure 1202 through the first port structure 1201. During the transmission process within the multimode interference structure 1202, the sound wave is decomposed into sound waves with multiple propagation modes, and finally converges into two acoustic mode spots at the end of the multimode interference structure 1202. Then, the two second port structures 1203 export the two acoustic mode spots formed by the interference of the sound waves with multiple propagation modes from the end of the multimode interference structure 1202.

[0046] Figure 3 A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0047] like Figure 4 As shown, the acoustic device in the acoustic chip of this embodiment can be a waveguide acoustic grating. In the waveguide acoustic grating, at least one of the acoustic core layer, acoustic cladding, or substrate can cause a periodic change in the propagation constant of the acoustic waveguide mode of the acoustic chip. For example, this periodic change can be caused by factors such as changes in shape (e.g., structural parameters such as thickness or width). However, this disclosure is not limited to this. In other embodiments, this periodic change can also be caused by the influence of a periodically changing external physical field (e.g., an electric field). For example, the acoustic core layer 120 includes an input structure 1204, a waveguide grating structure 1205, and an output structure 1206 connected in sequence. The input structure 1204 is used to input sound waves, thereby allowing the sound waves to be transmitted to the waveguide grating structure 1205. The waveguide grating structure 1205 can have alternating waveguide grating strips and recesses that are recessed relative to the waveguide grating strips, thereby allowing the sound waves to be modulated during propagation within the waveguide grating structure 1205. Then, the modulated sound waves can be transmitted to the output structure 1206 for output.

[0048] In other embodiments of this disclosure, two acoustic chips with waveguide grating structures 1205 can be cascaded to form two cascaded acoustic mirrors, thus creating a Fabry-Perot resonant cavity. By controlling the acoustic reflectivity of the waveguide grating structure and the spacing between the waveguide grating strips, the linewidth of the Fabry-Perot resonant cavity can be adjusted, thereby adjusting the wavelength difference or frequency difference between two adjacent transmission peaks or reflection peaks in the sound wave to achieve sound wave modulation.

[0049] Based on this, the waveguide grating structure 1205 features a periodically alternating waveguide grating strip structure. This periodically alternating design allows for periodic modulation of the input acoustic wave propagation constant. When the modulation period satisfies βΛ=π (β is the acoustic propagation constant, Λ is the grating period), coupling of the forward and backward propagation acoustic modes can be achieved, enabling acoustic wave reflection within a certain bandwidth. Changing the modulation period to a gradually varying grating structure allows for chirped grating strips, achieving acoustic reflection with a wider bandwidth.

[0050] Figure 4 A schematic diagram of a waveguide gate structure in an acoustic chip according to yet another embodiment of this disclosure is shown. Figure 5 As shown, in this embodiment, the recessed portion of the waveguide grating structure 1205 that is recessed relative to the grating strip can be configured as follows: Figure 5 The recessed portion shown in (a) in the figure, which is recessed in the horizontal direction, can also be configured as follows: Figure 6 The recess shown in (b) is a vertically recessed portion.

[0051] Figure 6 A schematic diagram of a waveguide gate structure in an acoustic chip according to yet another embodiment of this disclosure is shown. Figure 6 As shown, a passive, periodic metal layer 150 can be designed on the waveguide grating structure. For example, refer to... Figure 6 As can be seen, a metal layer 150 is formed on some parts of the waveguide grating structure, while no metal layer 150 is formed on others. This allows the acoustic propagation constant to be periodically modulated. It should be noted that, for this design, the sound velocity of the metal layer 150 material needs to match the sound velocity of the acoustic core layer. For example, the material of the metal layer 150 can include silver or copper.

[0052] Figure 7 A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0053] like Figure 7As shown in (a) of this embodiment, the acoustic device in the acoustic chip can be an acoustic microdisk resonant cavity. For example, the acoustic core layer 120 of the acoustic microdisk resonant cavity may include a first waveguide structure, a microdisk resonant structure 1208, and a second waveguide structure. It should be noted that the first waveguide structure can both input and output sound waves, and the second waveguide structure can also both input and output sound waves. Thus, one of the first and second waveguide structures can be used to input sound waves, and the other to output sound waves. Alternatively, both can couple sound waves to and from the microdisk resonant structure 1208. Based on this, the first waveguide structure will be referred to as the input / output structure 1207, and the second waveguide structure as the input / output structure 1209.

[0054] Based on this, input / output structures 1207 and 1209 can receive sound waves and couple them to the microdisk resonant structure, or couple sound waves from the microdisk cavity to the input / output structures 1207 and 1209 for output. The microdisk resonant structure 1208 can modulate the sound waves. The coupling can include at least one of direct coupling or evanescent field coupling.

[0055] For example, the acoustic core layer 120 may include an input / output structure 1207, a microdisk resonant structure 1208, and an input / output structure 1209 arranged sequentially along a first horizontal direction. The input / output structure 1207 may extend along a second horizontal direction intersecting (e.g., perpendicular to) the first horizontal direction and be spaced apart from the microdisk resonant structure 1208. The input / output structure 1207 can receive sound waves and couple them to the microdisk resonant structure 1208. After the sound waves are coupled to the input / output structure 1209 via the microdisk resonant structure 1208, the sound waves output by the input / output structure 1209 are modulated sound waves. The input / output structure 1209 may extend along the second horizontal direction or a third horizontal direction intersecting both the first and second horizontal directions, and be connected to the microdisk resonant structure 1208, or even be formed as a single unit. However, this embodiment is not limited to this; in other embodiments, the input / output structure 1209 may also be spaced apart from the microdisk resonant structure 1208. Figure 7 As shown in (b), the input / output structure 1207 and the microdisk resonant structure 1208 are spaced apart. The input / output structure 1209 is also spaced apart from the microdisk resonant structure 1208. The input sound wave transmits its energy to the microdisk resonant structure 1208 through evanescent field coupling between the input / output structure 1207 and the microdisk resonant structure 1208. The sound wave is modulated in the microdisk resonant structure 1208, and the modulated sound wave is transmitted to the input / output structure 1209 for output through evanescent field coupling.

[0056] In this embodiment of the disclosure, the microdisk resonant structure 1208 can be as follows: Figure 8 The standard disk structure shown in (b) can also be other shapes, or even something like... Figure 8 The irregularly shaped structure is shown in (a). Input / output structures 1207 and 1209 can be strip-shaped, but are not limited to this. By controlling the contour shape of the microdisk resonant structure 1208, a whispering aisle structure or a chaotic acoustic structure can be constructed that allows sound waves to propagate along the edge of the microdisk. The microdisk resonant structure 1208 can achieve sound wave energy input and output through evanescent field coupling with the input / output structures 1207 and 1209, or it can directly inject sound wave energy into the microdisk resonant structure 1208 by directly connecting it to the input / output structures 1207 and 1209. By controlling the coupling strength between the microdisk resonant structure 1208 and the input / output structures 1207 and 1209, overcoupling, critical coupling, and undercoupling can be adjusted to regulate the modulation capability of the acoustic core layer 120 on sound waves.

[0057] Figure 8 A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0058] like Figure 8 As shown, the acoustic device in the acoustic chip of this embodiment can be an acoustic arrayed waveguide grating. The acoustic core layer of the acoustic arrayed waveguide grating may include an input waveguide structure 910, a first free-evolution structure 920, an arrayed waveguide structure 930, a second free-evolution structure 940, and an output waveguide structure 950 connected in sequence. The input waveguide structure 910 can be used to input acoustic waves. The first free-evolution structure 920 can transmit the acoustic waves from the input waveguide structure 910 to multiple waveguide gratings included in the arrayed waveguide structure 930. The multiple waveguide gratings can be arranged at intervals and have different lengths relative to each other to split the acoustic signals of different frequencies in the acoustic waves from the first free-evolution structure 920 and apply different phases. The second free-evolution structure 940 can transmit the split acoustic signals to the output waveguide structure 950 as modulated acoustic waves for output.

[0059] Thus, sound waves accumulate different phases after passing through waveguides of varying lengths in an arrayed waveguide structure. By designing a suitable arrayed waveguide structure, an input sound wave of a specific frequency can be dispersed into multiple waveguide gratings of different lengths and then converged into a second free-evolving structure. Due to the dispersive effect of the waveguide structure, sound waves propagating in the waveguide at frequencies different from the specific frequency will be focused at different spatial locations within the free-evolving structure. Therefore, an arrayed waveguide structure can converge simultaneously incident sound waves of different frequencies to different output waveguide ports, achieving spatial separation of sound wave signals of different frequencies.

[0060] Figure 8 A schematic diagram of an acoustic chip according to yet another embodiment of the present disclosure is shown.

[0061] like Figure 9 As shown in (a) of this embodiment, the acoustic device in the acoustic chip can be a coupled acoustic waveguide array. In this embodiment, the acoustic core layer 120 of the coupled acoustic waveguide array also includes a plurality of waveguide strips 1210 spaced apart from each other.

[0062] Each waveguide strip includes a first portion 1211 and a second portion 1212. The first portion 1211 and the second portion 1212 of each waveguide strip have different widths and / or different spacing distances from adjacent waveguide strips, such that the first portion and the second portion have different coupling strengths with adjacent waveguide strips. For example, the first portion 1211 and the second portion 1212 of each waveguide strip have different spacing distances from adjacent waveguide strips, such that the first portion has a first coupling strength, and the second portion has a second coupling strength different from the first coupling strength, to modulate the acoustic wave propagating within each waveguide strip to obtain a modulated acoustic wave. The first coupling strength characterizes the coupling strength of the acoustic wave propagating in the first portion to the adjacent waveguide strip, and the second coupling strength characterizes the coupling strength of the acoustic wave propagating in the second portion to the adjacent waveguide strip.

[0063] Based on this, by controlling the spacing between the first part 1211 and the second part 1212 of multiple waveguide strips 1210 and their adjacent waveguide strips and / or by making the first part 1211 and the second part 1212 have different widths, a coupled waveguide array with complex interactions can be constructed. By utilizing the geometric dimensions of multiple waveguide strips 1210 at different positions and the spacing between different waveguide strips, different positions between different waveguide strips can be made to have different coupling strengths, thereby achieving control over the transmission of acoustic waves in the waveguide.

[0064] Building upon this foundation, different topological models can be simulated using acoustic chips with coupled waveguide array structures, enabling the study of topological phonons. Furthermore, by introducing external physical fields such as electric, magnetic, or thermal fields to regulate the acoustic chip, real-time evolution control of topological phonon circuits can be achieved.

[0065] like Figure 9 As shown in (b), by controlling the spacing between multiple waveguide strips 1210, different parts of the multiple waveguide strips 1210 have different coupling strengths, and the propagation of the input sound wave in the acoustic chip is controlled by the spacing between the multiple waveguide strips 1210.

[0066] According to embodiments of this disclosure, the acoustic core layer 120 has lateral confinement capability for the transmitted sound waves. The sound waves transmitted in the acoustic core layer 120 can propagate and evolve along the route and structure of the acoustic core layer 120. At the same time, the sound waves propagating in the acoustic core layer 120 are localized in the lateral width of the wavelength scale, which can greatly enhance the energy density of the sound waves and enhance the interaction between sound and matter.

[0067] According to embodiments of this disclosure, the acoustic chip utilizes structural acoustic propagation parameters such as the width, thickness, or material anisotropy of the acoustic core layer 120, which can be freely adjusted, to better control the dispersion, coupling, or interference of the sound waves transmitted in the acoustic core layer 120.

[0068] Figure 10 A flowchart illustrating a method for manufacturing an acoustic chip according to an embodiment of the present disclosure is shown schematically.

[0069] like Figure 10 Figure 10 Figure 11 Figure 11 As shown, the method for manufacturing an acoustic chip in this embodiment includes operations S1110 to S1130.

[0070] In operation S1110, an acoustic waveguide layer is formed on the substrate.

[0071] In operation S1120, the acoustic waveguide layer is patterned to obtain the acoustic core layer.

[0072] In operation S1130, an acoustic cladding is formed, which at least partially surrounds the outer periphery of the acoustic core.

[0073] According to embodiments of this disclosure, a suitable acoustic core layer is formed by patterning the acoustic waveguide layer of an acoustic chip using photolithography, based on actual needs. A solid acoustic cladding can then be formed around the acoustic core layer using processes such as atomic layer deposition. However, it should be understood that the embodiments of this disclosure are not limited to this; other processes can be used to form a solid acoustic cladding, or a gaseous cladding can be formed using other processes. This disclosure does not limit this to any particular process, as long as it satisfies the inventive concept of this disclosure. The acoustic wave propagating within the acoustic waveguide is modulated using its own structural characteristics. Thus, the sound wave evolves as it propagates along a specific path within the acoustic core layer, and the transmission of the sound wave can be controlled using the structural characteristics of the acoustic core layer itself.

[0074] According to embodiments of this disclosure, due to the different sound velocities of the acoustic cladding and the acoustic core layer, most of the sound waves are confined to the acoustic core layer during transmission within the acoustic chip. Simultaneously, because the acoustic cladding surrounds the acoustic core layer, preventing direct contact with the outside environment, the sound wave loss within the acoustic core layer is also reduced.

[0075] In this embodiment, the acoustic cladding can also be etched (e.g., using dry etching) to form etched holes. These etched holes extend within the acoustic cladding and are spaced apart from the acoustic core layer. Metallic material is deposited within the etched holes to obtain a physical field source.

[0076] According to embodiments of this disclosure, a physical field source is introduced into the acoustic chip through a metallic material, thereby regulating the acoustic chip.

[0077] According to embodiments of this disclosure, by etching the acoustic cladding and depositing metal material in the etched holes as conductive wiring, direct contact between the metal material and the acoustic core layer is avoided, thus preventing the influence of external physical fields on the transmission of sound waves in the acoustic core layer when the acoustic chip is controlled.

[0078] The parameter selection in this disclosure depends on the specific design requirements. Some specific implementations can be described here using lithium niobate thin film on sapphire as the material for phonon chips, but the implementations of various devices in this disclosure are not limited thereto.

[0079] In this embodiment, fabricating an acoustic chip with conductive wiring, using a silicon cladding and lithium niobate as the acoustic core layer, can include the following steps: First, a lithium niobate acoustic core layer is formed on a substrate. Then, conductive wiring is formed on the substrate using metal deposition processes such as overlay and electron beam evaporation. Next, a silicon layer is deposited as the acoustic cladding. Then, a deep silicon etching process is used to etch through the silicon above the conductive wiring, forming contact holes. Based on this, a metal material can be deposited within the contact holes. It is worth noting that, if necessary, an insulating layer can also be deposited on the inner wall of the contact holes to prevent leakage between the acoustic cladding and the metal material due to electrical contact when the acoustic cladding material is conductive. Finally, conductive wiring can be formed on the top surface of the silicon cladding to obtain the acoustic chip.

[0080] In other embodiments of this disclosure, an acoustic chip with an integrated acoustic multimode interferometer structure can also be used as an example. The fabrication process includes steps 11 to 14.

[0081] Step 11: Determine the width of the first port structure, the width of the second port structure, and the morphology of the multimode interference structure through numerical calculation, and calculate the etching depth of the acoustic core layer.

[0082] Step 12: Transfer the calculated integrated acoustic multimode interferometer structure pattern onto photoresist using electron beam exposure.

[0083] Step 13: After development, the image on the photoresist is transferred to the lithium niobate acoustic core layer by plasma etching, and the etching depth is determined by controlling the etching time.

[0084] Step 14: After removing the residual adhesive, the desired acoustic chip with an integrated acoustic multimode interferometer structure is obtained.

[0085] In another embodiment of this disclosure, an acoustic chip with an integrated waveguide acoustic grating structure can also be fabricated as an example, and the fabrication process includes steps 21 to 25.

[0086] Step 21: Determine parameters such as the width of the waveguide grating structure, the etching depth of the waveguide grating strip, the duty cycle and number of periods of the periodic structure of the waveguide grating strip, and the cavity length of the Fabry-Perot resonator through numerical calculation.

[0087] Step 22: Transfer the calculated waveguide pattern onto the photoresist using electron beam exposure.

[0088] Step 23: After development, the image on the photoresist is transferred to the lithium niobate acoustic core layer by plasma etching, and the etching depth is determined by controlling the etching time.

[0089] Step 24: Repeat steps 2 and 3 to etch a waveguide grating structure with periodicity or repeat steps 2 and 3 to deposit periodic metal material on the waveguide.

[0090] Step 25: After removing the residual adhesive, the designed acoustic chip with an integrated waveguide acoustic grating structure is obtained.

[0091] In another embodiment of this disclosure, an acoustic chip with an integrated acoustic microdisk resonator structure can also be fabricated as an example, and the fabrication process includes steps 31 to 34.

[0092] Step 31: Determine the morphology of the microdisk resonant structure, the widths of the input and output structures, the coupling distances between the input and output structures and the microdisk resonant cavity, and the waveguide etching depth through numerical calculation.

[0093] Step 32: Transfer the calculated microdisk resonant cavity structure pattern onto photoresist using electron beam exposure.

[0094] Step 33: After development, the image on the photoresist is transferred to the lithium niobate acoustic core layer by plasma etching, and the etching depth is determined by controlling the etching time.

[0095] Step 34: After removing the residual adhesive, an acoustic chip with an integrated acoustic microdisk resonator structure is obtained.

[0096] In another embodiment of this disclosure, an acoustic chip with an integrated acoustic array waveguide grating structure can also be fabricated as an example, and the fabrication process includes steps 41 to 44.

[0097] Step 41: Determine the parameters of the input waveguide structure, the first free evolution structure, the second free evolution structure, the array waveguide structure, and the output waveguide structure through numerical calculation, and determine the crystal orientation and etching depth of the waveguide.

[0098] Step 42: The calculated integrated acoustic array waveguide grating structure pattern is transferred onto photoresist by electron beam exposure.

[0099] Step 43: After development, the image of the integrated acoustic array waveguide gate structure on the photoresist is transferred to the lithium niobate acoustic core layer by plasma etching, and the etching depth is determined by controlling the etching time.

[0100] Step 44: After removing the residual adhesive, an acoustic chip with an integrated acoustic array waveguide grating structure is obtained.

[0101] In another embodiment of this disclosure, an acoustic chip with a coupled acoustic waveguide array can also be fabricated as an example, and the fabrication process includes steps 51 to 54.

[0102] Step 51: Determine the width of waveguide strips at different positions and the spacing between different waveguide strips through numerical calculation, and determine the crystal orientation and etching depth of the waveguide strips.

[0103] Step 52: Transfer the calculated pattern of the coupled acoustic waveguide array structure onto the photoresist using electron beam exposure.

[0104] Step 53: After development, the image of the photoresist-coupled acoustic waveguide array is transferred to the lithium niobate acoustic core layer by plasma etching, and the etching depth is determined by controlling the etching time.

[0105] Step 54: After removing the residual adhesive, an acoustic chip with a coupled acoustic waveguide array structure is obtained.

[0106] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0107] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. An acoustic chip, characterized by The acoustic chip comprises: a substrate; an acoustic device disposed on the substrate, comprising an acoustic core layer and an acoustic cladding layer at least partially surrounding an outer periphery of the acoustic core layer, wherein the acoustic cladding layer and the acoustic core layer have different acoustic speeds so as to at least partially localize acoustic waves in the acoustic core layer in the acoustic device.

2. The acoustic chip of claim 1, wherein, The acoustic cladding layer comprises at least one of a solid cladding layer and a gaseous cladding layer.

3. The acoustic chip of claim 1, wherein, The acoustic cladding layer is a solid cladding layer. The acoustic chip further comprises a physical field source physically spaced apart from the acoustic core layer; the physical field source comprises conductive wiring extending inside the acoustic cladding layer and / or extending on a surface of the acoustic cladding layer; The physical field source is used to provide a modulating field to the acoustic core layer to modulate the acoustic waves.

4. The acoustic chip of claim 1, wherein, The acoustic device is an acoustic multi-mode interferometer; wherein the acoustic core layer comprises at least one first port structure, a multi-mode interference structure and at least one second port structure connected in sequence; wherein, The at least one first port structure is used to input acoustic waves; The multi-mode interference structure is used to cause interference of multiple intrinsic modes contained in the acoustic waves; The at least one second port structure is used to output acoustic waves having an acoustic mode field distribution due to the interference.

5. The acoustic chip of claim 1, wherein, The acoustic device is a waveguide acoustic grating, wherein at least one of the acoustic core layer, the acoustic cladding layer and the substrate has a periodic variation.

6. The acoustic chip of claim 1, wherein, The acoustic device is an acoustic micro-disk resonant cavity, wherein the acoustic core layer comprises a first waveguide structure, a micro-disk resonant structure and a second waveguide structure; wherein the first waveguide structure and the second waveguide structure can both couple acoustic waves to the micro-disk resonant structure and couple acoustic waves out of the micro-disk resonant structure. The coupling comprises direct coupling and / or evanescent field coupling.

7. The acoustic chip of claim 1, wherein, The acoustic device is an acoustic array waveguide grating, wherein the acoustic core layer comprises an input waveguide structure, a first free evolution structure, an array waveguide structure, a second free evolution structure and an output waveguide structure connected in sequence; wherein, The input waveguide structure is used to input acoustic waves; The first free evolution structure is used to transmit the acoustic waves to multiple waveguide grating bars included in the array waveguide structure, respectively, the multiple waveguide grating bars having different lengths relative to each other; The array waveguide structure is used to split acoustic signals from different frequencies in the acoustic waves; The second free evolution structure is used to transmit the split acoustic signals to the output waveguide structure.

8. The acoustic chip of claim 1, wherein, The acoustic device is a coupled acoustic waveguide array, wherein the acoustic core layer comprises multiple waveguide bars spaced apart from each other; Each waveguide bar comprises a first portion and a second portion, the first portion and the second portion of each waveguide bar having different widths from each other and / or having different spacing distances from adjacent waveguide bars, so that the first portion and the second portion have different coupling strengths with adjacent waveguide bars.

9. A method of manufacturing an acoustic chip, characterized by, The method comprises: forming an acoustic waveguide layer on a substrate; patterning the acoustic waveguide layer to obtain an acoustic core layer; the acoustic core layer is used to modulate acoustic propagation parameters of acoustic waves propagating therein based on a structure thereof; forming an acoustic cladding; the acoustic cladding at least partially surrounds an outer periphery of the acoustic core; the acoustic cladding has a different acoustic velocity than the acoustic core so as to at least partially localize the acoustic wave within the acoustic core.

10. The method of claim 9, wherein, The method further comprises: etching the acoustic cladding to form an etch hole; the etch hole extends within the acoustic cladding and is spaced apart from the acoustic core; depositing a metallic material within the etch hole to form a physical field source.

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