阅读说明：本技术 基于γ-石墨二炔的可调频纳机电谐振器 (Adjustable frequency nano electromechanical resonator based on gamma-graphite diyne ) 是由 田文超 李文华 冯学贵 陈勇 于 2020-06-22 设计创作，主要内容包括：本发明公开了一种基于γ-石墨二炔的可调频纳机电谐振器,其包括：两个温控电极(1)、复合薄膜(2)、源极电极(3)、SiO<Sub>2</Sub>衬底(4)、栅极电极(5)、Si基底(6)、高介电陶瓷基底(7)和漏极电极(8)。两个温控电极对称分布于复合薄膜上表面两侧,复合薄膜由形状记忆聚合物温控层、聚二甲基硅氧烷介质层与γ-石墨二炔导电层组成,复合薄膜位于源极和漏极和SiO<Sub>2</Sub>衬底上表面,源、漏极分别位于SiO<Sub>2</Sub>衬底内侧,栅极位于高介电陶瓷上表面正中位置。通过温控电极激发温控层内部大分子链活性,改变其弹性模量；控制复合薄膜抗弯刚度变化,实现谐振器大范围调频功能。本发明谐振损耗低、可靠性高,可用于射频微波通信设备。(The invention discloses a frequency-adjustable nano electromechanical resonator based on gamma-graphite diyne, which comprises: two temperature control electrodes (1), a composite film (2), a source electrode (3), SiO 2 The transistor comprises a substrate (4), a gate electrode (5), a Si substrate (6), a high dielectric ceramic substrate (7) and a drain electrode (8). Two temperature control electrodes are symmetrically distributed on two sides of the upper surface of the composite film, the composite film consists of a shape memory polymer temperature control layer, a polydimethylsiloxane medium layer and a gamma-graphite diyne conducting layer, and the composite filmThe film is located on the source and drain and SiO 2 The source and drain electrodes are respectively arranged on the upper surface of the substrate and are respectively positioned on the SiO 2 The grid is positioned at the center of the upper surface of the high dielectric ceramic on the inner side of the substrate. The activity of macromolecular chains in the temperature control layer is excited by the temperature control electrode, so that the elastic modulus of the temperature control layer is changed; the bending rigidity change of the composite film is controlled, and the function of large-range frequency modulation of the resonator is realized. The invention has low resonance loss and high reliability, and can be used for radio frequency microwave communication equipment.)

1. An adjustable-frequency nano electromechanical resonator based on gamma-graphite diyne comprises SiO₂Substrate (4), Si base (6), grid electrode (5), source electrode (3), drain electrode (8) and compound film (2), its characterized in that: the device also comprises two temperature control electrodes (1) and a high-dielectric ceramic substrate (7);

the 2 temperature control electrodes (1) are symmetrically distributed on two sides of the upper surface of the composite film (2), and the elastic modulus and rigidity of the composite film are changed through the temperature control electrodes to change the resonant frequency;

the Si substrate (6) is symmetrically distributed on two sides of the upper surface of the high-dielectric ceramic substrate (7) to form a double-layer substrate structure;

the grid transmission line (5) is positioned in the middle of the upper surface of the high-dielectric ceramic substrate (7);

the composite film (2) is positioned on the source electrode (3), the drain electrode (8) and SiO₂The upper surface of the substrate (4) adopts a three-layer structure consisting of a temperature control layer (21), a dielectric layer (22) and a conductive layer (23) from top to bottom.

2. A resonator according to claim 1, characterized in that the composite film (2) in the form of a three-layer structure has an upper temperature control layer (21) of a shape memory polymer, a middle dielectric layer (22) of polydimethylsiloxane and a lower conductive layer (23) of gamma-graphite diyne.

3. The resonator of claim 1, wherein the 2 temperature control electrodes (1) are made of Au material with high conductivity to reduce energy loss and electrostatic disturbance.

4. The resonator according to claim 1, characterized in that the source electrode (3), the drain electrode (8) and the gate electrode (5) are made of Au or Pt, Ti alloy material.

5. A resonator according to claim 2, characterized in that the temperature control layer (21) is made of a shape memory polymer, the elastic modulus of which is variable, and the microstructure changes such as relaxation, cross-linking and phase change of the macromolecular chain activity are triggered by the temperature, and when the temperature reaches the glass transition temperature, the elastic modulus of the shape memory polymer is sharply reduced; the elastic modulus of the shape memory polymer increases dramatically when its temperature is below the glass transition temperature.

Technical Field

The invention belongs to the technical field of electronic components, in particular to a tunable-frequency-nano electromechanical resonator which can be used for radio-frequency microwave communication equipment.

Technical Field

The nanoelectromechanical resonator is an indispensable basic component in most communication equipment at present, and is a core device based on the development of the manufacturing technology of the nanoelectromechanical system, and the resonant frequency is generated through the interconversion of mechanical energy and electric energy. The microwave radio frequency resonance antenna has the advantages of small volume, light weight, high resonance frequency, large specific surface area and high sensitivity, is widely applied to the field of radio frequency microwave communication such as resonance type sensors, signal generators, encoders, accelerometers, radio frequency resonance antennas, filters, navigation and clock systems and the like, and is very suitable for the requirements of the development of modern wireless communication technology.

At present, the frequency modulation mode of the tunable micro-nano electromechanical resonator mainly focuses on a multi-center frequency resonator combination method and a method for changing the structural rigidity from the outside of a system. The radio frequency front end still adopts a plurality of different center frequency resonators to combine into a resonator group, and a single resonator unit or a plurality of resonator units are selected to work simultaneously through a selection switch so as to achieve the purpose of selecting signals in different frequency bands. However, the multi-center frequency resonator group has the disadvantages of overlarge volume, low reliability, difficult integration and the like, and cannot meet the requirements of high integration and miniaturization of a high-performance resonator. The external stiffness method is divided into a bending stiffness method based on applying axial load to change a system and an external stiffness method based on introducing an external excitation source mode. No matter the structure external loading method or the external excitation method, the structure rigidity is changed from the outside of the system, and the elastic modulus of the material is not changed essentially, so that the adjustable frequency is narrow, the reliability is low, and the process difficulty is higher.

"a microelectromechanical resonator integrated with a photonic crystal matrix and a processing method thereof" are disclosed in CN110311642A by bosch et al of the university of electronic technology in 2019, as shown in fig. 1, external input electrodes 2 and output electrodes 3 are symmetrically disposed on both sides of the top end of a supporting platform 1 of the microelectromechanical resonator, external ground electrodes 4 are symmetrically disposed on both sides of both electrodes, a resonator 6 is fixedly suspended in the center of the top end of the supporting platform 1 through two supporting beams 5, photonic crystal matrices 7 are symmetrically prevented at both ends, interdigital electrodes on the resonator 6 are respectively connected with the external electrodes 2 and 3 through corresponding metal wires, and each photonic crystal matrix 7 has 3 × 12 unit cells. Although the structure of the micro-electromechanical resonator can effectively prevent energy dissipation, reduce insertion loss and return loss and improve quality factor, the following problems exist:

1) the resonator contains the crystal matrix, and the size is great, and it is difficult to integrate:

2) the resonance frequency is lower, at MHz level, and does not meet the requirement of high frequency;

3) the requirement on etching is high, and the process is complex;

4) the tuning range of the working frequency is narrow.

WO2019067488A1 to Michael Cullinan et al, university of Texas, 2019 discloses Graphene microelectromechanical systems (media) resonator, which is adjustable based on strain frequency and forms a layer of SiO on the surface of Si substrate 1, as shown in FIG. 2₂The resonator has the advantages that the dielectric layer 2 and the dielectric layer 2 sandwich the back grid layer 3, the upper surface of the dielectric layer 2 is the patterned copper substrate 4, the graphene sheet layer 5 with the thickness of 1-3 atoms is suspended on the copper substrate 4 and is fixed on the surface of the copper substrate 4 through the top gold electrode 6, the resonator is excited by heat, the resonant frequency is tuned by controlling the surface tension on the graphene sheet, the structure can enable the resonant frequency to be tuned uniformly, sense the tiny change and have high sensitivity, but the following problems exist:

1) the graphene sheet layer with the thickness of 1-3 atoms is not easy to separate and transfer, has numerous defects and low reliability;

2) the thermal drive is adopted, the heating distance is limited, and the power consumption is large;

3) the surface tension of the graphene is difficult to control, the process is complex, and the reliability is low;

4) the method for changing the surface tension of the graphene resonant beam belongs to a structure external loading method, and the adjustable frequency range is narrow.

Disclosure of Invention

The invention aims to provide a frequency-adjustable nano electromechanical resonator based on gamma-graphite diyne to change the bending rigidity of a composite film, complete the large-range frequency modulation function of an NEMS resonator and realize the multi-band, high-reliability and low-loss performance of the NEMS resonator aiming at the defects of the prior art.

In order to achieve the purpose, the frequency-adjustable nano-electromechanical resonator based on gamma-graphite diyne comprises SiO₂Substrate, Si base, grid electrode, source electrode, drain electrode and composite film, its characterized in that: the device also comprises two temperature control electrodes and a high dielectric ceramic substrate;

the two temperature control electrodes are symmetrically distributed on two sides of the upper surface of the composite film, and the elastic modulus and the rigidity of the composite film are changed through the temperature control electrodes, so that the change of the resonant frequency is realized;

the Si substrate is symmetrically distributed on two sides of the upper surface of the high-dielectric ceramic substrate to form a double-layer substrate structure;

the grid transmission line is positioned in the middle of the upper surface of the high-dielectric ceramic substrate;

the composite film is of a three-layer structure consisting of a temperature control layer, a dielectric layer and a conductive layer from top to bottom, wherein each layer is made of different materials and is positioned on the upper surfaces of a source electrode, a drain electrode and a SiO2 substrate.

Preferably, the composite film in the form of a three-layer structure has the upper temperature control layer made of a shape memory polymer, the middle dielectric layer made of polydimethylsiloxane and the lower conductive layer made of gamma-graphite diyne.

Preferably, the two temperature control electrodes are made of Au materials with high conductivity so as to reduce energy loss and electrostatic disturbance.

Preferably, the source electrode, the drain electrode and the gate electrode are made of Au or Ti alloy material.

Compared with the prior art, the invention has the following advantages:

1) the composite film adopted by the invention is formed by compounding the temperature control layer, the dielectric layer and the conducting layer which are laminated from top to bottom, the elastic modulus of the composite film is variable, the wide-range change of the resonant frequency can be realized, the response time is shortened, and the broadband and multiband tuning target is met.

2) According to the invention, two temperature control electrode units are symmetrically fixed on the surface of the composite film, and the internal deformation of the composite film can be realized by applying voltage, so that the bending rigidity of the system is changed, and the resonance frequency is improved, therefore, the device has the characteristics of high frequency and high quality factor.

3) The invention adopts the Si-high dielectric ceramic double-layer substrate structure, and the dielectric coefficient is high, thereby effectively ensuring to reduce the energy loss and the parasitic resistance and simultaneously reducing the electrostatic disturbance force.

Drawings

FIG. 1 is a diagram of a prior art MEMS resonator integrated with a photonic crystal matrix;

fig. 2 is a structural diagram of a conventional graphene microelectromechanical resonator;

FIG. 3 is a three-dimensional block diagram of a nanoelectromechanical resonator of the present invention;

fig. 4 is a front view of the composite film in the resonator of the present invention.

Detailed Description

Referring to fig. 3, the invention relates to a gamma-graphite diyne-based broadband tunable frequency nano electromechanical resonator structure, which comprises two temperature control electrodes 1, a composite film 2, a source electrode 3, two SiO electrodes₂A substrate 4, a gate electrode 5, two Si substrates 6, a high dielectric ceramic base 7, and a drain electrode 8. Wherein: two temperature control electrodes 1 are positioned at two ends of the upper surface of the composite film 2, and two SiO electrodes₂The substrate 4 is arranged at two ends of the lower surface of the composite film 2, and the source electrode 3 and the drain electrode 8 are symmetrically distributed on the two SiO layers₂The substrate 4 is arranged at the inner side of the composite film 2 and between the Si substrates 6, the two Si substrates 6 are arranged at two ends of the upper surface of the high dielectric ceramic base 7, and the grid electrode 5 is arranged in the middle of the upper surface of the high dielectric ceramic base.

The 2 temperature control electrodes 1 are symmetrically distributed on two sides of the surface of the composite film 2, Au is selected as the material, electrochemical deposition is adopted on the upper surface of the composite film, and due to the fact that Au has a high conductive characteristic, the deformation of the composite film 2 is regulated and controlled by adjusting loading voltage, the bending rigidity of a system can be changed, resonance frequency change is achieved, and energy loss and electrostatic disturbance are reduced.

The Si substrate 6 is symmetrically distributed on two sides of the upper surface of the high-dielectric ceramic substrate 7 to form a double-layer substrate structure, the grid transmission line 5 is fixed in the middle of the upper surface of the high-dielectric ceramic substrate 7 through a deposition process to realize signal transmission control, and the high-dielectric ceramic substrate 7 avoids crosstalk between the transmission lines.

The source electrode 3, the drain electrode 8 and the gate electrode 5 are made of the same material and can be made of Au or Pt or Ti alloy, and the Au or Pt or Ti alloy has high conductivity, so that the interface energy loss and the insertion loss can be effectively reduced, and the high power and the high reliability of the resonator are ensured. The material of the three electrodes adopted in the present example is, but not limited to, an Au material.

Referring to fig. 4, the composite film 2 has a three-layer structure composed of a temperature control layer 21, a dielectric layer 22 and a conductive layer 23 from top to bottom, and is disposed on the source electrode 3, the drain electrode 8 and SiO₂The upper surface of the substrate 4. The three layers are made of different materials, wherein the upper temperature control layer 21 is made of shape memory polymer, the middle medium layer 22 is made of polydimethylsiloxane, and the lower conducting layer 23 is made of gamma-graphite diyne.

The elastic modulus of the shape memory polymer temperature control layer 21 can change along with the change of temperature, when the temperature reaches the glass transition temperature, the elastic modulus of the shape memory polymer can be sharply reduced, and when the temperature is lower than the glass transition temperature, the elastic modulus of the shape memory polymer can be sharply increased; the temperature change of the shape memory polymer of the temperature control layer is controlled by the two temperature control electrodes 1, the activation of a macromolecular chain is excited, the microstructure changes such as relaxation, crosslinking and phase change are generated, the elastic modulus of the shape memory polymer is changed from the inside of the material, the bending rigidity of the composite film is adjusted, the large-range frequency modulation function of the NEMS resonator is realized, and meanwhile, the shape memory polymer has the characteristic of environmental protection because of the degradability.

The gamma-graphite diyne conducting layer 23 is a single-layer carbon atom, has high carrier mobility, superplasticity and super-stability, can ensure high reliability and low loss of a resonator, is transferred to the surface of a dielectric layer 22 adopting polydimethylsiloxane by a Langmuir-Blpdgett film making technology, is made into a composite film 2 by an excimer laser nano-imprinting technology and a shape memory polymer temperature control layer 21, and is imprinted on the surfaces of an Au drain electrode 8 and an Au source electrode 3 by a hot imprinting technology.

The working principle and the process of the invention are as follows:

1) and (3) excitation process:

a direct current bias voltage is applied to the grid electrode, a capacitor is formed between the composite film and the grid, and the gamma-graphite diyne conducting layer in the composite film is subjected to downward attraction, so that the whole composite film is subjected to initial deformation under the action of electrostatic force; and then adding a tiny radio frequency alternating input signal to excite the grid electrode on the basis of introducing bias voltage, enabling the capacitor to be continuously charged and discharged along with the change of the alternating signal, causing the electrostatic force borne by the composite film to be continuously changed, generating synchronous oscillation, and enabling the composite film to have the maximum deflection when the frequency of the excitation signal is close to or reaches the intrinsic frequency of the resonator, so that the resonator generates resonance.

2) And (3) frequency modulation process:

applying temperature control voltage on the temperature control electrode, generating indirect thermal response on the shape memory polymer of the temperature control layer due to resistance heat generation, activating the internal macromolecular chain structure, generating micro changes such as crosslinking, relaxation and phase change, and changing the network structure of the shape memory polymer, wherein when the shape memory polymer is lower than the glass transition temperature ht, the elastic modulus of the shape memory polymer is E₁(ii) a When the glass transition temperature is higher than ht, the shape memory polymer undergoes phase change, and the elastic modulus thereof is changed to E₂(ii) a When the temperature of the shape memory polymer is reduced to be lower than the glass transition temperature ht again, the elastic modulus of the shape memory polymer is rapidly recovered to be E₁That is, the change of the elastic modulus of the shape memory polymer can be realized by controlling the change of the temperature control voltage, so that the equivalent bending rigidity of the whole composite film is changed along with the change of the elastic modulus of the shape memory polymerThe corresponding modal frequency of the resonator changes accordingly. When the frequency of the exciting signal is close to the new natural frequency of the system, the resonator resonates again, and the frequency modulation function is realized. Under the regulation of temperature control voltage, the temperature control layer shape memory polymer corresponds to different elastic moduli in a wide temperature range, so that the composite film has correspondingly different equivalent bending stiffness, and the function of large-range frequency modulation of the resonator can be realized.

The foregoing description is only an example of the present invention and should not be construed as limiting the invention, as it will be apparent to those skilled in the art that various modifications and variations in form and detail can be made without departing from the principle and structure of the invention after understanding the present disclosure and the principles, but such modifications and variations are considered to be within the scope of the appended claims.