Bulk acoustic wave reading device of semiconductor thin film mechanical oscillator and preparation method thereof

Abstract

The present application provides a bulk acoustic wave reading device for a semiconductor thin film mechanical oscillator and a preparation method thereof, and relates to the technical field of semiconductor devices and their preparation. The bulk acoustic wave reading device includes a bulk acoustic wave piezoelectric structure layer and a semiconductor thin film structure layer; the bulk acoustic wave piezoelectric structure layer includes a first substrate layer, a metal growth layer and a piezoelectric thin film layer; the semiconductor thin film structure layer includes: a second substrate layer, a first semiconductor thin film layer, a second semiconductor thin film layer and a superconducting resonant circuit layer; the middle of the second substrate layer is a hollow structure, and the middle of the first semiconductor thin film layer includes a part of a suspended semiconductor thin film layer; the superconducting resonant circuit layer forms a supermode by resonant coupling with the piezoelectric thin film layer based on the piezoelectric effect, and the superconducting resonant circuit layer is used to excite the supermode and output the vibration information of the semiconductor thin film mechanical oscillator. The bulk acoustic wave reading device provided by the present application has the characteristics of simple structure, simple preparation, high integration and easy integration with other devices.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor devices and their preparation, and in particular to a bulk acoustic wave reading device of a semiconductor thin film mechanical oscillator and a preparation method thereof. Background Art

[0002] Semiconductor thin film mechanical oscillator is a thin film structure based on semiconductor materials. It has a high quality factor and has important application value in the fields of quantum physics information, quantum precision measurement and sensor detection.

[0003] The reading of semiconductor thin film mechanical oscillators mainly depends on the extraction and analysis of their vibration information to perform quantum control of semiconductor thin film mechanical oscillators. At present, quantum control of semiconductor thin film mechanical oscillators is generally performed through superconducting resonators (based on superconducting resonant cavities) in the microwave frequency band. For example, a superconducting resonant cavity (or microwave resonant cavity) can be prepared based on superconducting thin films using traditional micromachining technology. Based on the suspended mechanical capacitor coupling structure of the superconducting resonant cavity and the low-frequency semiconductor thin film mechanical oscillator, a reading device for semiconductor thin film mechanical oscillators can be constructed, through which the information of the processing results of the quantum computing chip can be coherently transmitted and stored.

[0004] However, the inventors of the present application have discovered that with the increase in the number of bits in superconducting quantum computing chips, the increase in the demand for microwave resonant cavity modes, and the requirement for miniaturization of reading devices, higher technical requirements are placed on superconducting resonator interface circuits, causing traditional superconducting resonators to face technical problems such as the need for multi-mode expansion and the existence of crosstalk.

[0005] For example, the inventor believes that the current reading device still has the following problems:

[0006] 1. The general frequency band of traditional superconducting resonator interface circuits is between 4GHz and 8GHz, the circuit size is generally in the millimeter level, and can only provide a single mode of microwave resonance;

[0007] 2. The structure of the current multi-mode microwave resonant circuit is relatively complex, which makes the overall circuit area larger and easily causes crosstalk with the microwave circuit signal in the superconducting quantum chip;

[0008] 3. In a multi-mode microwave resonant circuit, there is an uneven coupling strength between each mode and the semiconductor film. Summary of the invention

[0009] The present application provides a bulk acoustic wave reading device of a semiconductor thin film mechanical oscillator and a preparation method thereof, which are used to solve the technical problems faced by traditional superconducting resonators, such as the need for multi-mode expansion and the existence of crosstalk.

[0010] On the one hand, the present application provides a bulk acoustic wave reading device of a semiconductor thin film mechanical oscillator, including a bulk acoustic wave piezoelectric structure layer and a semiconductor thin film structure layer; the bulk acoustic wave piezoelectric structure layer includes: a first substrate layer; a metal growth layer, arranged on the first substrate layer in a first preset pattern; a piezoelectric film layer, arranged on the metal growth layer in a first preset pattern; the semiconductor thin film structure layer includes: a second substrate layer, including a first surface and a second surface; a first semiconductor film layer, arranged on the first surface; a second semiconductor film layer, arranged on the second surface; wherein the middle part of the second substrate layer is a hollow structure, and the middle part of the first semiconductor film layer includes a partially suspended semiconductor film layer; a superconducting resonant circuit layer, arranged on the first semiconductor film layer, the superconducting resonant circuit layer forms a supermode based on the piezoelectric effect, and the superconducting resonant circuit layer is used to excite the supermode and output the vibration information of the semiconductor thin film mechanical oscillator; wherein the bulk acoustic wave piezoelectric structure layer and the semiconductor thin film structure layer are flip-chip connected through a connecting component, and the center of the piezoelectric film layer corresponds to the center of the superconducting resonant circuit layer.

[0011] According to some embodiments of the present application, the superconducting resonant circuit layer includes: a superconducting resonant circuit, which is arranged in the central area of ​​the suspended semiconductor thin film layer; a signal input circuit, which is arranged on one side of the superconducting resonant circuit and provides an input signal for the superconducting resonant circuit; and a signal output circuit, which is arranged on the other side of the superconducting resonant circuit corresponding to the signal input circuit and outputs an output signal passing through the superconducting resonant circuit.

[0012] According to some embodiments of the present application, the superconducting resonant circuit is a concentric circle structure, and the center of the concentric circle structure is set at the center of the suspended semiconductor thin film layer.

[0013] According to another aspect of the present application, the present application also provides a method for preparing a bulk acoustic wave reading device of a semiconductor thin film mechanical oscillator, comprising preparing a bulk acoustic wave piezoelectric structure layer; preparing a semiconductor thin film structure layer; flip-chip connecting the bulk acoustic wave piezoelectric structure layer to the semiconductor thin film structure layer through a connecting component to obtain a bulk acoustic wave reading device; preparing the bulk acoustic wave piezoelectric structure layer comprises: setting an initial metal growth layer on a first substrate layer; setting an initial piezoelectric film layer on the initial metal growth layer; etching the initial piezoelectric film layer and the initial metal growth layer to obtain a piezoelectric film layer and a metal growth layer having a first preset pattern; preparing the semiconductor thin film structure layer comprises: setting a first semiconductor thin film layer and a second semiconductor thin film layer on two surfaces of a second substrate layer respectively; etching a portion of the semiconductor thin film layer in the central area of ​​the second semiconductor thin film layer based on the second preset pattern to obtain a partially exposed second substrate layer; etching the partially exposed second substrate layer so that the middle portion of the second substrate layer is a hollow structure, and the middle portion of the first semiconductor thin film layer includes a portion of a suspended semiconductor thin film layer; setting a superconducting resonant circuit layer on the first semiconductor thin film layer to obtain a semiconductor thin film structure layer.

[0014] According to some embodiments of the present application, a bulk acoustic wave piezoelectric structure layer is flip-chip connected to a semiconductor thin film structure layer through a connecting component to obtain a bulk acoustic wave reading device, comprising: after aligning the center of the piezoelectric thin film layer with the center of the superconducting resonant circuit layer, the bulk acoustic wave piezoelectric structure layer is flip-chip connected to the semiconductor thin film structure layer through a connecting component.

[0015] According to some embodiments of the present application, setting a superconducting resonant circuit layer on the first semiconductor thin film layer includes: setting a superconducting resonant circuit in the central area of ​​the suspended semiconductor thin film layer; setting a signal input circuit on one side of the superconducting resonant circuit; and setting a signal output circuit on the other side of the superconducting resonant circuit corresponding to the signal input circuit to obtain a superconducting resonant circuit layer.

[0016] According to some embodiments of the present application, the superconducting resonant circuit is a concentric circle structure, and the center of the concentric circle structure is set at the center of the suspended semiconductor thin film layer.

[0017] The bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator provided by the present application includes a bulk acoustic wave piezoelectric structure layer and a semiconductor thin film structure layer, and the bulk acoustic wave reading device is formed by flip-chip connecting the bulk acoustic wave piezoelectric structure layer and the semiconductor thin film structure layer. The bulk acoustic wave piezoelectric structure layer includes a piezoelectric thin film layer, and the semiconductor thin film structure layer includes a superconducting resonant circuit layer. Under excitation, the superconducting resonant circuit layer forms a resonant coupling with the piezoelectric thin film layer based on the piezoelectric effect to form a supermode, and the superconducting resonant circuit layer excites the supermode and outputs the vibration information of the semiconductor thin film mechanical oscillator, thereby completing the bulk acoustic wave reading of the semiconductor thin film mechanical oscillator.

[0018] This application uses piezoelectric transducer technology and piezoelectric effect to construct dispersion coupling (dispersion method) and energy conversion between the vibration of a high-quality factor semiconductor thin film mechanical oscillator and a high-frequency bulk acoustic wave oscillator, thereby realizing the reading of vibration information of the semiconductor thin film mechanical oscillator.

[0019] The present application replaces the existing multi-mode microwave resonant cavity interface circuit with a bulk acoustic wave vibrator. The piezoelectric film structure layer provided by the present application has a strong mode volume, and can realize multiple (up to hundreds) microwave resonance modes on a piezoelectric film layer of a hundred micrometers in size. Multiple microwave resonance modes can be coupled with the same semiconductor mechanical vibrator, and multiple radio frequency modes can be coupled with the semiconductor mechanical vibrator and coherent information exchange can be realized under the premise of retaining a microwave transducer circuit. The acoustic mode integration of the bulk acoustic wave piezoelectric structure layer is high, which can make the coupling strength of each mode with the semiconductor film evenly distributed, and can also avoid the problem of electromagnetic crosstalk in the multi-mode microwave circuit structure.

[0020] The bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator provided in the present application also has the ability to precisely control mode splitting, can construct Brillouin-type acoustic-mechanical interaction, can increase the single-photon coupling intensity by four orders of magnitude, etc.

[0021] The bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator provided in the present application has the characteristics of simple structure, simple preparation, high integration (area miniaturization processing) and easy integration processing with other devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic diagram showing a bulk acoustic wave piezoelectric structure layer according to an embodiment of the present application;

[0024] Figure 2 A schematic diagram showing a semiconductor thin film structure layer according to an embodiment of the present application;

[0025] Figure 3 A schematic diagram showing a bulk acoustic wave reading device according to an embodiment of the present application;

[0026] Figure 4 An equivalent schematic diagram showing a parallel plate capacitor structure according to an embodiment of the present application;

[0027] Figure 5 A schematic diagram showing an acoustic mode of an embodiment of the present application;

[0028] Figure 6 A schematic diagram showing a superconducting resonant circuit according to an embodiment of the present application;

[0029] Figure 7 A schematic diagram showing a process of a method for preparing a bulk acoustic wave reading device according to an embodiment of the present application;

[0030] Figure 8 Another schematic flow chart showing a method for preparing a bulk acoustic wave reading device according to an embodiment of the present application;

[0031] Fig. 9 A schematic diagram showing a preparation process of a bulk acoustic wave piezoelectric structure layer 1 according to an embodiment of the present application is shown;

[0032] Fig.10 Another schematic flow chart showing a method for preparing a bulk acoustic wave reading device according to an embodiment of the present application;

[0033] Fig.11A schematic diagram showing a process for preparing a semiconductor thin film structure layer 1 according to an embodiment of the present application is shown;

[0034] Fig.12 A schematic diagram showing a process of a method for preparing a superconducting resonance circuit layer according to an embodiment of the present application.

[0035] Description of reference numerals:

[0036] Bulk acoustic wave piezoelectric structure layer 10; semiconductor thin film structure layer 20;

[0037] First substrate layer 11; metal growth layer 12; piezoelectric film layer 13; initial metal growth layer 12A; initial piezoelectric film layer 13A;

[0038] A second substrate layer 21; a first semiconductor thin film layer 22; a second semiconductor thin film layer 23; a superconducting resonant circuit layer 24;

[0039] A first surface S1 and a second surface S2;

[0040] Hollow structure 211; suspended semiconductor thin film layer 221;

[0041] Connecting assembly 30;

[0042] Superconducting resonance circuit 241; signal input circuit 242; signal output circuit 243. DETAILED DESCRIPTION

[0043] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0044] The described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices, etc. may be adopted. In these cases, known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0045] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0046] The terms "first", "second" and the like in the specification and claims of this application and the above drawings are used to distinguish different objects rather than to describe a specific order.

[0047] The following is a clear and complete description of the technical solution of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0048] According to one aspect of the present application, the present application provides a bulk acoustic wave reading device of a semiconductor thin film mechanical oscillator.

[0049] According to an example embodiment, Figure 1 and Figure 2 As shown, the bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator includes a bulk acoustic wave piezoelectric structure layer 10 and a semiconductor thin film structure layer 20 .

[0050] According to an example embodiment, Figure 1 As shown, the bulk acoustic wave piezoelectric structure layer 10 includes a first substrate layer 11 , a metal growth layer 12 and a piezoelectric film layer 13 .

[0051] like Figure 1 As shown, the first substrate layer 11 is disposed at the bottom of the bulk acoustic wave piezoelectric structure layer 10. The first substrate layer 11 may be made of sapphire.

[0052] Exemplarily, the first substrate layer 11 may be a double-sided polished sapphire substrate with a thickness of 250 μm.

[0053] The metal growth layer 12 is arranged on the first substrate layer 11 in a first preset pattern. Figure 1 As shown, the metal growth layer 12 is disposed on the upper surface of the first substrate layer 11, and can be used as a seed layer for growing the piezoelectric film layer 13. The metal growth layer 12 can be made of metal molybdenum.

[0054] Exemplarily, the metal growth layer 12 may be a metal molybdenum thin film layer with a thickness of 100 nm.

[0055] The piezoelectric film layer 13 is disposed on the metal growth layer 12 in a first preset pattern. Figure 1 As shown, the piezoelectric film layer 13 is epitaxially grown on the metal growth layer 12 based on PVD (Physical Vapor Deposition). The piezoelectric film layer 13 can be made of a material having a piezoelectric effect such as aluminum nitride or gallium nitride.

[0056] It can be understood here that the material having the piezoelectric effect contains a bulk acoustic wave vibrator, that is, the piezoelectric film layer 13 also contains a bulk acoustic wave vibrator.

[0057] Exemplarily, the piezoelectric film layer 13 may be an aluminum nitride film layer with a thickness of 1 μm.

[0058] The first preset pattern may be a preset pattern that meets user needs and is obtained by etching and cleaning the initial piezoelectric film layer based on an etching technology.

[0059] For example, Figure 1 As shown, the first preset pattern may be a rectangle, such as a rectangle of 2 mm×3 mm.

[0060] According to an example embodiment, Figure 2 As shown, the semiconductor thin film structure layer 20 includes a second substrate layer 21 , a first semiconductor thin film layer 22 , a second semiconductor thin film layer 23 and a superconducting resonant circuit layer 24 .

[0061] like Figure 2 As shown, the second substrate layer 21 includes a first surface S1 and a second surface S2. The second substrate layer 21 can be made of silicon.

[0062] For example, the second substrate layer 21 may be a double-sided polished single-crystal silicon substrate with a thickness of 500 μm (the single-crystal silicon is <100> crystal phase).

[0063] The first semiconductor thin film layer 22 is disposed on the first surface S1 ; the second semiconductor thin film layer 23 is disposed on the second surface S2 .

[0064] like Figure 2 As shown, the first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 are grown on the two surfaces (the first surface S1 and the second surface S2) of the second substrate layer 21 based on LPCVD (Low Pressure Chemical Vapor Deposition). The first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 are deposited on the two surfaces of the second substrate layer 21 to form a semiconductor thin film structure layer 20 covered with double-sided semiconductor thin films.

[0065] The first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 are made of semiconductor materials such as silicon nitride or silicon carbide, which is not limited in the present application.

[0066] Exemplarily, the first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 may both be silicon nitride thin film layers with a thickness of 50 nm.

[0067] The middle portion of the second substrate layer 21 is a hollow structure 211 , and the middle portion of the first semiconductor thin film layer 22 includes a partially suspended semiconductor thin film layer 221 .

[0068] like Figure 2 As shown, the second substrate layer 21 includes a hollow structure 211 . Since the first semiconductor thin film layer 22 is disposed on the first surface S1 of the second substrate layer 21 , a suspended semiconductor thin film layer 221 is formed above the hollow structure 211 .

[0069] That is, the provision of the hollow structure 211 forms a superconducting resonant cavity between the suspended semiconductor film layer 221 and the second substrate layer 21 .

[0070] Exemplarily, the suspended semiconductor thin film layer 221 may be a square structure of 500 μm×500 μm.

[0071] According to an example embodiment, Figure 2 As shown, the superconducting resonant circuit layer 24 is disposed on the first semiconductor thin film layer 22 .

[0072] According to the exemplary embodiment, the bulk acoustic wave piezoelectric structure layer 10 and the semiconductor thin film structure layer 20 are flip-chip connected by the connection member 30 , and the center of the piezoelectric thin film layer 13 corresponds to the center of the superconducting resonance circuit layer 24 .

[0073] like Figure 3 As shown, the bulk acoustic wave piezoelectric structure layer 10 is inverted and fixedly connected to the semiconductor thin film structure layer 20 .

[0074] For example, the bulk acoustic wave piezoelectric structure layer 10 can be inverted and fixedly connected to the semiconductor thin film structure layer 20 by welding. Exemplarily, the connection component 30 can be an indium column or the like.

[0075] For another example, the bulk acoustic wave piezoelectric structure layer 10 may be inverted and fixedly connected to the semiconductor thin film structure layer 20 by bonding. For example, the connection component 30 may be epoxy resin or the like.

[0076] According to the exemplary embodiment, the superconducting resonance circuit layer 24 forms a supermode by resonant coupling with the piezoelectric thin film layer 13 based on the piezoelectric effect. The superconducting resonance circuit layer 24 is used to excite the supermode and output vibration information of the semiconductor thin film mechanical oscillator.

[0077] For example, Figure 4As shown, a superconducting resonant circuit layer 24 is arranged on the suspended semiconductor film layer 221, and the superconducting resonant circuit layer 24 can be used as a lower plate of the capacitor, and the metal growth layer 12 can be used as an upper plate of the capacitor, that is, a parallel plate capacitor structure is formed between the superconducting resonant circuit layer 24 and the metal growth layer 12, and a piezoelectric film layer 13 is interlayered in the parallel plate capacitor structure.

[0078] like Figure 4 As shown, the bulk acoustic wave oscillators in the piezoelectric film layer 13 have a mode distribution with equal spacing, and the spacing between modes depends on the thickness d of the first substrate layer 11 and the propagation speed v of the sound wave in the first substrate layer 11. The spacing between modes is called the free spectrum spacing, which can be expressed as:

[0079] ;

[0080] in, is the free spectrum spacing.

[0081] Since a parallel plate capacitor structure is formed between the superconducting resonance circuit layer 24 and the metal growth layer 12, the electric field of the superconducting resonance cavity is mainly distributed between the superconducting resonance circuit layer 24 and the metal growth layer 12. When the electric field lines of the superconducting resonance circuit layer 24 pass through the piezoelectric film layer 13, the piezoelectric film layer 13 converts the electromagnetic field into high-frequency sound waves based on the piezoelectric effect, which stimulates the first substrate layer 11 to generate Figure 5 The acoustic mode shown. The vibration of the high-frequency acoustic mode will change the effective dielectric constant between the parallel plate capacitor structure, thereby changing the frequency of the superconducting resonant cavity. Therefore, based on the piezoelectric effect and the above-mentioned superconducting resonant circuit layer 24 and parallel plate capacitor structure, the resonant coupling of the body acoustic wave and the superconducting resonant mode can be achieved.

[0082] like Figure 5 As shown, the acoustic mode (bulk acoustic wave) resonantly couples with the superconducting resonant mode to form a new mode, namely the supermode, also known as the hybrid mode or polarization mode.

[0083] like Figure 5 As shown, the mode after resonant coupling shows degenerate splitting (e.g. Figure 5The mode splitting distance represents the coupling strength 2g between the superconducting resonant cavity mode and the body acoustic wave mode. The coupling strength 2g depends on the gap between the upper and lower plates of the parallel plate capacitor structure. Since the upper plate of the capacitor is arranged above the suspended semiconductor film layer 221, when the suspended semiconductor film layer 221 is excited to vibrate, the distance between the upper plate of the capacitor and the lower plate of the capacitor will also change periodically with the vibration. This will produce periodic modulation on the coupling strength 2g and the frequency gap of the superconducting mode splitting. That is, the mode splitting frequency gap depends on the vibration displacement x of the semiconductor film mechanical oscillator of the first semiconductor film layer 22. Therefore, the superconducting resonant circuit layer 24 can read the vibration signal (such as the resonance frequency and electromagnetic loss line width and other information) of the semiconductor film mechanical oscillator of the first semiconductor film layer 22 by measuring the frequency change 2g (x).

[0084] Through the above exemplary embodiments, the bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator provided by the present application includes a bulk acoustic wave piezoelectric structure layer and a semiconductor thin film structure layer, and the bulk acoustic wave piezoelectric structure layer and the semiconductor thin film structure layer are flip-chip connected to form a bulk acoustic wave reading device. The bulk acoustic wave piezoelectric structure layer includes a piezoelectric thin film layer, and the semiconductor thin film structure layer includes a superconducting resonant circuit layer. Under excitation, the superconducting resonant circuit layer forms a resonant coupling with the piezoelectric thin film layer based on the piezoelectric effect to form a supermode, and the supermode is excited by the superconducting resonant circuit layer and the vibration information of the semiconductor thin film mechanical oscillator is output, so that the bulk acoustic wave reading of the semiconductor thin film mechanical oscillator can be completed.

[0085] This application uses piezoelectric transducer technology and piezoelectric effect to construct dispersion coupling (dispersion method) and energy conversion between the vibration of a high-quality factor semiconductor thin film mechanical oscillator and a high-frequency bulk acoustic wave oscillator, thereby realizing the reading of vibration information of the semiconductor thin film mechanical oscillator.

[0086] The present application replaces the existing multi-mode microwave superconducting resonant cavity interface circuit with a bulk acoustic wave vibrator. The piezoelectric film structure layer provided by the present application has a strong mode volume, and can realize multiple (up to hundreds) microwave resonance modes on a piezoelectric film layer of a hundred micrometers in size. Multiple microwave resonance modes can be coupled with the same semiconductor mechanical vibrator, and multiple radio frequency modes can be coupled with the semiconductor mechanical vibrator and coherent information exchange can be realized under the premise of retaining a microwave transducer circuit. The acoustic mode integration of the bulk acoustic wave piezoelectric structure layer is high, which can make the coupling strength of each mode with the semiconductor film evenly distributed, and can also avoid the problem of electromagnetic crosstalk in the multi-mode microwave circuit structure.

[0087] The bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator provided in the present application also has the ability to precisely control mode splitting, can construct Brillouin-type acoustic-mechanical interaction, can increase the single-photon coupling intensity by four orders of magnitude, etc.

[0088] The bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator provided in the present application has the characteristics of simple structure, simple preparation, high integration (area miniaturization processing) and easy integration processing with other devices.

[0089] Alternatively, if Figure 6 As shown, the superconducting resonance circuit layer 24 includes a superconducting resonance circuit 241 , a signal input circuit 242 , and a signal output circuit 243 .

[0090] like Figure 6 As shown, the superconducting resonant circuit 241 is disposed in the central region of the suspended semiconductor film layer 221. The superconducting resonant circuit 241 can be used as an antenna electrode that forms a resonance coupling with the piezoelectric film layer 13.

[0091] Exemplarily, the superconducting resonant circuit 241 may be made of a metal aluminum film.

[0092] The signal input circuit 242 is arranged on one side of the superconducting resonance circuit 241 to provide an input signal for the superconducting resonance circuit 241 ; the signal output circuit 243 is arranged on the other side of the superconducting resonance circuit 241 corresponding to the signal input circuit 242 to output an output signal passing through the superconducting resonance circuit 241 .

[0093] For example, the signal input circuit 242 and the signal output circuit 243 are coplanar waveguide structures (CPW). The signal input circuit 242 inputs the superconducting resonator electromagnetic wave signal (i.e., the input pulse of the superconducting resonant circuit 241). After the input pulse enters the superconducting resonant circuit 241, an output pulse is obtained, and the signal output circuit 243 outputs the output pulse. The external analysis device receives the output pulse, and obtains information such as the resonant frequency and electromagnetic loss line width of the superconducting resonant circuit 241 through analysis.

[0094] Alternatively, if Figure 6 As shown, the superconducting resonant circuit 241 is a concentric circle structure, and the center of the concentric circle structure is set at the center of the suspended semiconductor film layer 221.

[0095] For example, by setting the superconducting resonant circuit 241 as a concentric circle structure, the electric field lines of the transducing superconducting resonant circuit 241 can all pass through the piezoelectric layer, thereby achieving extremely high electric field energy conversion efficiency and improving the coupling strength and information conversion efficiency between the RF segment body acoustic wave mode and the semiconductor mechanical oscillator.

[0096] Optionally, the superconducting resonant circuit 241 may also be configured as a double rectangular structure, which is not limited in the present application.

[0097] According to another aspect of the present application, the present application also provides a method for preparing a bulk acoustic wave reading device of a semiconductor thin film mechanical oscillator. Figure 7 As shown, the preparation method includes steps S100-S300.

[0098] According to an example embodiment, in step S100 , a bulk acoustic wave piezoelectric structure layer 10 is prepared.

[0099] like Figure 8 As shown, step S100 may include steps S110 - S130 .

[0100] In step S110 , an initial metal growth layer 12A is disposed on the first substrate layer 11 .

[0101] For example, Fig. 9 As shown, the first substrate layer 11 may be made of sapphire. For example, the first substrate layer 11 may be a double-sided polished sapphire substrate with a thickness of 250 μm.

[0102] The initial metal growth layer 12A is disposed on the first substrate layer 11 based on the magnetron sputtering technology. Fig. 9 As shown, the initial metal growth layer 12A is disposed on the upper surface of the first substrate layer 11 and can be used as a seed layer for growing the initial piezoelectric film layer 13A. The initial metal growth layer 12A can be made of metal molybdenum.

[0103] Exemplarily, the initial metal growth layer 12A may be a metal molybdenum thin film layer with a thickness of 100 nm.

[0104] In step S120 , an initial piezoelectric thin film layer 13A is disposed on the initial metal growth layer 12A.

[0105] like Fig. 9 As shown, an initial piezoelectric film layer 13A is epitaxially grown on the initial metal growth layer 12A based on PVD (Physical Vapor Deposition). The initial piezoelectric film layer 13A can be made of a material having a piezoelectric effect, such as aluminum nitride or gallium nitride.

[0106] It can be understood here that the material having the piezoelectric effect contains a bulk acoustic wave vibrator, that is, the initial piezoelectric film layer 13A also contains a bulk acoustic wave vibrator.

[0107] Exemplarily, the initial piezoelectric film layer 13A may be an aluminum nitride film layer with a thickness of 1 μm.

[0108] In step S130, the initial piezoelectric film layer 13A and the initial metal growth layer 12A are etched to obtain the piezoelectric film layer 13 and the metal growth layer 12 having a first preset pattern.

[0109] like Fig. 9 As shown, based on the laser direct writing patterning technology, a photoresist is spin-coated on the initial piezoelectric film layer 13A to produce a rectangular pattern with a first preset pattern (such as a rectangle of 2 mm×3 mm). After development and fixing, the initial metal growth layer 12A and the initial piezoelectric film layer 13A are etched based on the photoresist pattern as a mask, and cleaned with a photoresist cleaning agent, so as to obtain a Fig. 9 The piezoelectric film layer 13 and the metal growth layer 12 are shown. Thus, a bulk acoustic wave piezoelectric structure layer 10 including the first substrate layer 11, the metal growth layer 12 and the piezoelectric film layer 13 can be obtained.

[0110] like Figure 7 As shown, in step S200, a semiconductor thin film structure layer 20 is prepared.

[0111] like Fig.10 As shown, step S200 may include steps S210-S240.

[0112] In step S210 , a first semiconductor thin film layer 22 and a second semiconductor thin film layer 23 are respectively disposed on two surfaces of the second substrate layer 21 .

[0113] like Fig.11 As shown, the second substrate layer 21 includes a first surface S1 and a second surface S2. The second substrate layer 21 can be made of silicon.

[0114] For example, the second substrate layer 21 may be a double-sided polished single-crystal silicon substrate with a thickness of 500 μm (the single-crystal silicon is <100> crystal phase).

[0115] Based on LPCVD (Low Pressure Chemical Vapor Deposition), the first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 are grown on the two surfaces (the first surface S1 and the second surface S2) of the second substrate layer 21 respectively. The first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 are deposited on the two surfaces of the second substrate layer 21 to form a semiconductor thin film structure layer 20 covered with double-sided semiconductor thin films.

[0116] The first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 are made of semiconductor materials such as silicon nitride or silicon carbide, which is not limited in the present application.

[0117] Exemplarily, the first semiconductor thin film layer 22 and the second semiconductor thin film layer 23 may both be silicon nitride thin film layers with a thickness of 50 nm.

[0118] In step S220 , based on the second preset pattern, a portion of the semiconductor thin film layer in the central area of ​​the second semiconductor thin film layer 23 is etched to obtain a partially exposed second substrate layer 21 .

[0119] For example, Fig.11 As shown, the second surface S2 is released based on the RIE (Reactive Ion Etching) etching process to obtain a pattern with a second preset pattern (for example, a square of 1077 μm×1077 μm), and then the following can be obtained: Fig.11 The second substrate layer 21 is shown as being partially exposed.

[0120] In step S230 , the partially exposed second substrate layer 21 is etched so that the middle of the second substrate layer 21 is a hollow structure, and the middle of the first semiconductor thin film layer 22 includes a partially suspended semiconductor thin film layer 221 .

[0121] like Fig.11 As shown, the partially exposed second substrate layer 21 is placed in an etching solution (such as a KOH potassium hydroxide solution) so that the partially exposed second substrate layer 21 can react with the etching solution until the entire exposed second substrate layer 21 is completely etched. <100> Crystalline phase can be obtained as Fig.11 The hollow structure 211 shown has a cut-off surface with an angle of 54.74° with the horizontal direction.

[0122] Since the first semiconductor thin film layer 22 does not react with the etching solution, a structure such as Fig.11 The suspended semiconductor thin film layer 221 is shown.

[0123] Exemplarily, the suspended semiconductor thin film layer 221 may be a square structure of 500 μm×500 μm.

[0124] In step S240 , a superconducting resonant circuit layer 24 is disposed on the first semiconductor thin film layer 22 to obtain a semiconductor thin film structure layer 20 .

[0125] For example, Fig.11 As shown, based on the laser direct writing technology and the electron beam coating process, a superconducting resonant circuit layer 24 is set on the first semiconductor thin film layer 22, so that a semiconductor thin film structure layer 20 including a second substrate layer 21, a first semiconductor thin film layer 22, a second semiconductor thin film layer 23 and a superconducting resonant circuit layer 24 can be obtained.

[0126] Exemplarily, the superconducting resonant circuit layer 24 may be an aluminum film layer with a thickness of 120 nm.

[0127] In step S300, the bulk acoustic wave piezoelectric structure layer 10 is flip-chip connected to the semiconductor thin film structure layer 20 via a connecting component 30 to obtain a bulk acoustic wave reading device.

[0128] Optionally, in step S300 , after the center of the piezoelectric film layer 13 is aligned with the center of the superconducting resonant circuit layer 24 , the bulk acoustic wave piezoelectric structure layer 10 is flip-chip connected to the semiconductor film structure layer 20 through the connecting component 30 .

[0129] like Figure 3 As shown, the bulk acoustic wave piezoelectric structure layer 10 is inverted and then fixedly connected to the semiconductor thin film structure layer 20 .

[0130] For example, the bulk acoustic wave piezoelectric structure layer 10 can be inverted and fixedly connected to the semiconductor thin film structure layer 20 by welding. Exemplarily, the connection component 30 can be an indium column or the like.

[0131] For another example, the bulk acoustic wave piezoelectric structure layer 10 may be inverted and fixedly connected to the semiconductor thin film structure layer 20 by bonding. For example, the connection component 30 may be epoxy resin or the like.

[0132] Alternatively, if Fig.12 As shown, step S240 may also include steps S241-S243.

[0133] In step S241 , a superconducting resonant circuit 241 is disposed in the central region of the suspended semiconductor thin film layer 221 .

[0134] In step S242 , the signal input circuit 242 is provided on one side of the superconducting resonance circuit 241 .

[0135] In step S243 , a signal output circuit 243 is provided on the other side of the superconducting resonance circuit 241 corresponding to the signal input circuit 242 to obtain a superconducting resonance circuit layer 24 .

[0136] like Figure 6 As shown, the superconducting resonant circuit 241 is arranged in the central area of ​​the suspended semiconductor film layer 221. The superconducting resonant circuit 241 can be used as an antenna electrode that forms a resonant coupling with the piezoelectric film layer 13. The signal input circuit 242 is arranged on one side of the superconducting resonant circuit to provide an input signal to the superconducting resonant circuit 241; the signal output circuit 243 is arranged on the other side of the superconducting resonant circuit 241 corresponding to the signal input circuit 242, and outputs an output signal passing through the superconducting resonant circuit 241.

[0137] Alternatively, if Figure 6As shown, the superconducting resonant circuit 241 is a concentric circle structure, and the center of the concentric circle structure is set at the center of the suspended semiconductor film layer 221.

[0138] For example, by setting the superconducting resonant circuit 241 as a concentric circle structure, the electric field lines of the transducing superconducting resonant circuit 241 can all pass through the piezoelectric layer, thereby achieving extremely high electric field energy conversion efficiency and improving the coupling strength and information conversion efficiency between the RF segment body acoustic wave mode and the semiconductor mechanical oscillator.

[0139] Optionally, the superconducting resonant circuit 241 may also be configured as a double rectangular structure, which is not limited in the present application.

[0140] The bulk acoustic wave reading device of the semiconductor thin film mechanical oscillator provided in the present application has the characteristics of simple structure, simple preparation, high integration (area miniaturization processing) and easy integration processing with other devices.

[0141] Finally, it should be noted that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions of the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A bulk acoustic wave reading device for a semiconductor thin film mechanical oscillator, characterized in that: It includes a bulk acoustic wave piezoelectric structure layer and a semiconductor thin film structure layer; The bulk acoustic wave piezoelectric structure layer comprises: a first substrate layer; A metal growth layer is arranged on the first substrate layer in a first preset pattern; A piezoelectric film layer is disposed on the metal growth layer in the first preset pattern; The semiconductor thin film structure layer comprises: A second substrate layer including a first surface and a second surface; A first semiconductor thin film layer is disposed on the first surface; A second semiconductor thin film layer is disposed on the second surface; Wherein, the middle part of the second substrate layer is a hollow structure, and the middle part of the first semiconductor thin film layer includes a part of the suspended semiconductor thin film layer; A superconducting resonance circuit layer is provided on the first semiconductor film layer, the superconducting resonance circuit layer forms a supermode by resonant coupling with the piezoelectric film layer based on the piezoelectric effect, and the superconducting resonance circuit layer is used to excite the supermode and output vibration information of the semiconductor film mechanical oscillator; The bulk acoustic wave piezoelectric structure layer and the semiconductor film structure layer are flip-chip connected via a connecting component, and the center of the piezoelectric film layer corresponds to the center of the superconducting resonance circuit layer.

2. The bulk acoustic wave reading device according to claim 1, characterized in that: The superconducting resonant circuit layer comprises: A superconducting resonant circuit is arranged in the central area of ​​the suspended semiconductor thin film layer; A signal input circuit is arranged at one side of the superconducting resonance circuit to provide an input signal to the superconducting resonance circuit; The signal output circuit is arranged at the other side of the superconducting resonance circuit corresponding to the signal input circuit, and outputs the output signal passing through the superconducting resonance circuit.

3. The bulk acoustic wave reading device according to claim 2, characterized in that: The superconducting resonance circuit is a concentric circle structure, and the center of the concentric circle structure is set at the center of the suspended semiconductor film layer.

4. A method for preparing a bulk acoustic wave reading device of a semiconductor thin film mechanical oscillator, characterized in that: The preparation method is used to prepare the bulk acoustic wave reading device according to any one of claims 1 to 3, and the preparation method comprises: preparing a bulk acoustic wave piezoelectric structural layer; preparing a semiconductor thin film structure layer; The bulk acoustic wave piezoelectric structure layer is flip-chip connected to the semiconductor thin film structure layer through a connecting component to obtain the bulk acoustic wave reading device; The preparation of the bulk acoustic wave piezoelectric structure layer comprises: Disposing an initial metal growth layer on the first substrate layer; Disposing an initial piezoelectric film layer on the initial metal growth layer; Etching the initial piezoelectric film layer and the initial metal growth layer to obtain a piezoelectric film layer and a metal growth layer having a first preset pattern; The preparation of the semiconductor thin film structure layer comprises: Disposing a first semiconductor thin film layer and a second semiconductor thin film layer on two surfaces of the second substrate layer respectively; Based on the second preset pattern, etching a portion of the semiconductor thin film layer in the central area of ​​the second semiconductor thin film layer to obtain a partially exposed second substrate layer; Etching the partially exposed second substrate layer so that the middle of the second substrate layer is a hollow structure, and the middle of the first semiconductor thin film layer includes a partially suspended semiconductor thin film layer; A superconducting resonance circuit layer is provided on the first semiconductor thin film layer to obtain the semiconductor thin film structure layer.

5. The preparation method according to claim 4, characterized in that: The method of flip-chip connecting the bulk acoustic wave piezoelectric structure layer to the semiconductor thin film structure layer through a connecting component to obtain the bulk acoustic wave reading device comprises: After the center of the piezoelectric film layer is aligned with the center of the superconducting resonance circuit layer, the bulk acoustic wave piezoelectric structure layer is flip-chip connected to the semiconductor film structure layer through a connecting component.

6. The preparation method according to claim 4, characterized in that: The step of providing a superconducting resonance circuit layer on the first semiconductor thin film layer comprises: A superconducting resonant circuit is arranged in the central area of ​​the suspended semiconductor thin film layer; A signal input circuit is provided on one side of the superconducting resonant circuit; On the other side of the superconducting resonance circuit, a signal output circuit is arranged corresponding to the signal input circuit to obtain the superconducting resonance circuit layer.

7. The preparation method according to claim 6, characterized in that: The superconducting resonance circuit is a concentric circle structure, and the center of the concentric circle structure is set at the center of the suspended semiconductor film layer.

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