CN110601672A - High-temperature-stability surface acoustic wave filter and preparation method and application thereof - Google Patents
High-temperature-stability surface acoustic wave filter and preparation method and application thereof Download PDFInfo
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Classifications
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02543—Characteristics of substrate, e.g. cutting angles
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- H—ELECTRICITY
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- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02614—Treatment of substrates, e.g. curved, spherical, cylindrical substrates ensuring closed round-about circuits for the acoustical waves
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02637—Details concerning reflective or coupling arrays
- H03H9/02653—Grooves or arrays buried in the substrate
- H03H9/02661—Grooves or arrays buried in the substrate being located inside the interdigital transducers
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- H—ELECTRICITY
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- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02818—Means for compensation or elimination of undesirable effects
- H03H9/02834—Means for compensation or elimination of undesirable effects of temperature influence
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/64—Filters using surface acoustic waves
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
- H03H2003/023—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks the resonators or networks being of the membrane type
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- H—ELECTRICITY
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- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
- H03H2003/026—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks the resonators or networks being of the tuning fork type
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
The invention discloses a high-temperature stable surface acoustic wave filter and a preparation method and application thereof. The surface acoustic wave filter comprises a piezoelectric substrate and at least one flat surface; an interdigital transducer electrode fixedly disposed on the plane of the piezoelectric substrate; an insulating protective layer having two opposite surfaces, one of which is bonded on the plane of the piezoelectric substrate in a laminated manner and covers the interdigital transducer electrodes; the other surface is provided with a plurality of bulges distributed at intervals. The surface acoustic wave filter has the advantages of low frequency temperature coefficient, low Rayleigh wave spurious response, stable working performance, long service life and the like. In addition, the preparation method has controllable process conditions, and can effectively ensure stable performance, high yield and low cost of the prepared acoustic surface wave filter with high temperature stability.
Description
Technical Field
The invention belongs to the technical field of microelectronics, and particularly relates to a high-temperature stable surface acoustic wave filter and a preparation method and application thereof.
Background
Surface acoustic wave refers to the propagation of an acoustic wave on the surface of an elastomer, and this wave is called an elastic surface acoustic wave. The propagation velocity of surface acoustic waves is about 10 ten thousand times smaller than the velocity of electromagnetic waves. The surface acoustic wave filter is a special filter device which is made of piezoelectric materials such as quartz crystal, piezoelectric ceramics and the like by utilizing the piezoelectric effect and the physical characteristics of surface acoustic wave propagation. The piezoelectric effect is a phenomenon that when a crystal is subjected to a mechanical action, an electric field proportional to a pressure is generated. When the crystal with piezoelectric effect is acted by electric signal, it will also produce elastic deformation to send out mechanical wave (sound wave), i.e. the electric signal can be converted into sound signal. Since such an acoustic wave propagates only on the crystal surface, it is called a surface acoustic wave.
The surface acoustic wave filter is abbreviated as SAWF in English, and has the advantages of small volume, light weight, reliable performance and no need of complex adjustment. The key device for realizing adjacent frequency transmission in the cable television system. The surface acoustic wave filter has the advantages of flat frequency response, good rectangular coefficient, capability of compensating level loss by using an amplifier and the like. Therefore, the surface acoustic wave filter has been widely applied to the fields of communication and video.
The gulf war at the end of the 20 th century is the starting point of the modern novel war, wherein high-speed information transmission and antagonism play a key role, and the control on the high-speed information transmission is a new control point for competition of enemy and my parties in the modern novel war. Based on the advantages of the SAWF, the SAWF becomes an important frequency component in military information transmission and countermeasure equipment, including civil information transmission equipment. However, due to the influence of the frequency temperature coefficient of the conventional SAWF filter, in consideration of practical application, the pass band width needs to be greatly increased during design, so that a large amount of precious spectrum resources are inevitably occupied. And because the temperature coefficient of the frequency of the conventional SAWF filter is large, in military and civil application environments with large temperature change, the change of the electrical performance of the conventional SAWF filter can deteriorate the performance indexes of military and civil equipment. For example, the SAWF filter is an important component in the T/R channel of the phased array radar, and each T/R channel of the phased array radar has large temperature change due to heating or the influence of the external environment, so that the conventional SAWF has frequency drift and other electrical performance parameter changes due to large frequency temperature coefficient, and the phase change of each channel unit of the phased array radar is caused, and the overall electrical performance of the phased array radar is influenced. In addition, the existing SAWF filter also has a Rayleigh wave parasitic response phenomenon.
Although it is disclosed that a protection layer is also covered on the interdigital in the conventional SAWF filter, the protection layer is only for protection, and thus the rayleigh wave spurious response phenomenon of the SAWF filter cannot be effectively solved, and the problem of large frequency temperature coefficient of the SAWF filter cannot be reduced.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides an acoustic surface wave filter with high temperature stability and a preparation method thereof, so as to solve the defect that the temperature coefficient of the existing SAWF is large, so that the electrical performance parameters such as frequency drift and the like are changed.
To achieve the above object, according to one aspect of the present invention, there is provided an acoustic surface wave filter having high temperature stability. The high temperature stability surface acoustic wave filter includes:
the piezoelectric substrate at least has a plane;
an interdigital transducer electrode fixedly disposed on the plane of the piezoelectric substrate;
an insulating protective layer having two opposite surfaces, one of which is bonded on the plane of the piezoelectric substrate in a laminated manner and covers the interdigital transducer electrodes; the other surface is provided with a plurality of bulges distributed at intervals.
In another aspect of the present invention, a method for preparing the inventive acoustic surface wave filter with high temperature stability is provided. The preparation method of the acoustic surface wave filter with high temperature stability comprises the following steps:
preparing interdigital transducer electrodes on one plane of a piezoelectric substrate;
depositing an insulating protective film layer on the plane of the piezoelectric substrate, and enabling the insulating protective film layer to cover the interdigital transducer electrode;
and etching the outer surface of the insulating protection film layer to form a plurality of bulges distributed at intervals on the surface.
In another aspect of the invention, the invention also provides the application of the acoustic surface wave filter with high temperature stability. The acoustic surface wave filter with high temperature stability is applied to radars, mobile communication, channelized receivers and remote sensing and telemetry systems.
Compared with the prior art, the acoustic surface wave filter with high temperature stability has the advantages that the insulating protection layer covering the interdigital transducer electrodes is arranged, and the protrusions are distributed on the outer surface of the insulating protection layer to control, so that on one hand, the frequency temperature coefficient of the acoustic surface wave filter with high temperature stability is reduced, and even the frequency temperature coefficient is better than-4 ppm/DEG C and even close to 0; on the other hand, the insulating protective layer can cooperate with the piezoelectric substrate, the interdigital transducer electrode and other components, so that the Rayleigh wave parasitic response of the acoustic surface wave filter with high temperature stability is effectively reduced, and even disappears. Secondly, the insulating protection layer is arranged on the surface of the interdigital transducer electrode, so that the insulating protection layer can effectively play a role in protection, the corrosion resistance performance of the interdigital transducer is improved, and the stability of the working performance of the high-temperature-stability surface acoustic wave filter is improved and the service life of the high-temperature-stability surface acoustic wave filter is prolonged.
The preparation method of the acoustic surface wave filter with high temperature stability adopts the steps of firstly depositing the insulating protective film layer, and then carrying out directional etching treatment on the outer surface of the insulating protective film layer to form the surface with the protrusions distributed at intervals, so that the prepared acoustic surface wave filter with high temperature stability has low frequency temperature coefficient and low Rayleigh wave parasitic response phenomenon, and can play a role in protection, so that the prepared acoustic surface wave filter with high temperature stability has the advantages of stable working performance, long service life and the like. In addition, the preparation method has controllable process conditions, and can effectively ensure stable performance, high yield and low cost of the prepared acoustic surface wave filter with high temperature stability.
The acoustic surface wave filter with high temperature stability has low frequency temperature coefficient, low Rayleigh wave parasitic response, stable working performance and long service life. Therefore, the acoustic surface wave filter with high temperature stability can be effectively applied to the field of communication and video related devices, so that the working performance and the working stability of the corresponding devices are improved.
Drawings
FIG. 1 is a schematic diagram of a high temperature stable SAW filter according to an embodiment of the present invention;
FIG. 2 is a graph of the relationship between the electromechanical coupling coefficient and the Euler angle of the piezoelectric substrate of the acoustic surface wave filter with high temperature stability according to the embodiment of the present invention;
FIG. 3 is a graph of the electromechanical coupling coefficient of an SAW filter with high temperature stability versus the thickness of the interdigital transducer electrodes, hmet/λ, in accordance with embodiments of the present invention;
FIG. 4 is a graph of the relationship between the admittance of the SAW filter and the topography of the outer surface of the insulating protective layer for high temperature stability in accordance with embodiments of the present invention; wherein, fig. 4a is a topography map when the ratio SR of the protrusion top width a of the outer surface of the insulating protection layer to the root width B is 0.78; FIG. 4B is a graph of the profile of the outer surface of the insulating protective layer with a ratio SR of the protrusion top width A to the root width B of 0.38; FIG. 4c is an admittance diagram of the topography with a protrusion SR of 0.78 on the outer surface of the insulating protection layer; FIG. 4d is an admittance diagram of the topography with a protrusion SR of 0.38 on the outer surface of the insulating protection layer;
FIG. 5 is a graph of the relationship between the temperature coefficient of the frequency of the SAW filter and the total thickness of the insulating protective layer for high temperature stability according to the embodiment of the present invention;
FIG. 6 is a flow chart of a method for manufacturing a surface acoustic wave filter with high temperature stability according to an embodiment of the present invention;
FIG. 7 is a FT-IR spectrum of the acoustic surface wave filter at 400-2000 cm-1 after the insulating protective film layer is formed by deposition.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In one aspect, embodiments of the present invention provide an acoustic surface wave filter (hereinafter, collectively referred to as an acoustic surface wave filter) with high temperature stability. The structure of the acoustic surface wave filter with high temperature stability is shown in figure 1, and comprises a piezoelectric substrate 1, interdigital transducer electrodes 2 and an insulating protective layer 3.
The piezoelectric substrate 1 of the surface acoustic wave filter at least has a plane 11, and the plane 11 is used for arranging the interdigital transducer electrode 2. In one embodiment, the piezoelectric substrate 1 is LiTaO3At least one of (1). In addition, it is found that the euler angle of the material of the piezoelectric substrate 1 has an influence on the electromechanical coupling system, and in a further embodiment, the euler angle (0, θ, 0) θ of the material of the piezoelectric substrate 1 is any one of 38 °, 41 °, and 42 °. Specifically, as shown in FIG. 2, when the material of the insulating protection layer 3 and the thickness thereof are not changed to SiO2When the thickness of the interdigital transducer is 0.3 lambda (lambda is the acoustic wave length), the material of the interdigital transducer electrode 2 is copper, and the electrode thickness is 0.05 lambda, controlling the LiTaO material of the piezoelectric substrate 13The Euler angle of (a) affects the electromechanical coupling coefficient of the surface acoustic wave filter, specifically LiTaO3The euler angle of (a) and the electromechanical coupling system of the surface acoustic wave filter are shown in fig. 2. As can be seen from fig. 2, the material of the piezoelectric substrate 1 is LiTaO3And LiTaO3Cut to about 128 deg. i.e. LiTaO3The euler angle (0, theta, 0) theta of (a) is 38 deg.. In addition, the thickness of the piezoelectric substrate 1 may be a conventional thickness. Therefore, by controlling the kind of material and the characteristics of the piezoelectric substrate 1 such as Euler angle, the piezoelectric substrate 1 is made to function together with other devices such as the interdigital transducer electrode 2 and the insulating protective layerThe synergistic interaction is realized, so that the frequency temperature coefficient and the Rayleigh wave spurious response phenomenon of the surface acoustic wave filter are reduced, and the reduction of the coupling coefficient of the surface acoustic wave filter is improved.
The interdigital transducer electrode 2 contained in the acoustic surface wave filter is fixedly arranged on the plane 11 of the piezoelectric substrate 1; the interdigital transducer electrode 2 can be designed according to the requirement, and is arranged on the plane 11 according to the requirement of a surface acoustic wave filter. In one embodiment, the material of the interdigital transducer electrode 2 can be any one of Al, Cu, Ti, or an alloy of Al and Cu. The selection of the material of the interdigital transducer electrode 2 and the devices such as the piezoelectric substrate 1 cooperate to improve the frequency temperature coefficient and the Rayleigh wave parasitic response phenomenon of the surface acoustic wave filter, so as to improve the reduction of the coupling coefficient of the surface acoustic wave filter. In addition, based on the structure of the saw filter, it is found that adjusting the thickness (denoted as hmet) of the interdigital transducer electrode 2 also affects the electromechanical coupling coefficient of the saw filter, and the relationship between the hmet and the electromechanical coupling coefficient is shown in fig. 3. As can be seen from fig. 3, the electromechanical coupling coefficient decreases as the value of hmet increases under the premise that the thickness of the insulating protection layer 3 is constant. Therefore, the thickness hmet of the interdigital transducer electrode 2 is preferably 0.045-0.055 λ, preferably 0.05 λ.
The insulation protective layer 3 contained in the surface acoustic wave filter has two opposite surfaces, one of which is laminated and combined on the plane 11 of the piezoelectric substrate 1 and covers the interdigital transducer electrode 2; the other surface is formed with a plurality of protrusions 31 distributed at intervals. In this way, the insulating protective layer 3 covers the interdigital transducer electrode 2, and on one hand, the insulating protective layer can effectively play a role of a protective layer, so that the interdigital transducer electrode 2 is separated from adverse factors such as water vapor in the outside, and the stability of the working performance of the interdigital transducer electrode 2 is ensured, such as the performances of corrosion resistance and the like are improved; on the other hand, in the embodiment of the present invention, by changing the characteristics of the outer surface of the insulating protective layer 3, specifically, by forming the plurality of protrusions 31 on the outer surface of the insulating protective layer 3 at intervals, the temperature coefficient of the frequency of the surface acoustic wave filter can be reduced, for example, by adjusting and controlling the performance and the material of the interdigital transducer electrode 2 and the piezoelectric substrate 1 at the same time, the three components can perform a synergistic interaction effect, even the temperature coefficient of the frequency of the surface acoustic wave filter can be significantly reduced, and the rayleigh wave spurious response of the surface acoustic wave filter can be effectively reduced.
In addition, further research shows that the temperature coefficient of the frequency of the surface acoustic wave filter can be remarkably reduced, such as better than-4 ppm/DEG C and even close to 0, by controlling the shape and the size of the protrusions 31 on the outer surface of the insulating protection layer 3. And the Rayleigh wave spurious response of the acoustic surface wave filter can be reduced. Thus, in one embodiment, the shape of a single said protrusion 31 is controlled to: the width (A) of the top is smaller than the width (B) of the root, and the side of the single protrusion 31 is a slope. In a further embodiment, the ratio SR of the top width (a) to the root width (B) of a single projection 31 is 0.3-0.4, preferably the ratio SR is 0.38. In another embodiment, the height of the protrusions 31 is 1.0-1.1 μm, which is the vertical distance from the top to the root of a single protrusion 31. In a specific embodiment, the SR value is related to the acoustic surface wave filter admittance as shown in fig. 4. In fig. 4, when the material of the piezoelectric substrate 1 is LiTaO3The interdigital transducer electrode 2 is made of copper, and the insulating protective layer 3 is made of SiO2When the SR is controlled to be 0.78, as shown in fig. 4a, the rayleigh response phenomenon appears as seen from the acoustic surface wave filter admittance shown in fig. 4 c; when SR is 0.38, as shown in fig. 4b, the rayleigh response phenomenon does not appear and the rayleigh response substantially disappears as seen from the acoustic surface wave filter admittance shown in fig. 4 d.
In yet another embodiment, the distance between adjacent bumps 31 is controlled to be 0.3-0.8 μm (referring to the distance between the roots of adjacent bumps 31), for example, a single bump 31 can be formed at a position corresponding to a single electrode of the interdigital transducer electrode 2, that is, a single bump 31 is disposed directly above a single electrode of the interdigital transducer electrode 2. Thus, the distance between two adjacent bumps 21 is the same as the distance between adjacent metal interdigital strips contained in the interdigital transducer electrode 2. In addition, study was madeThe total thickness of the insulating and protective layer 3 (denoted hsio) was found2) Also has an effect on the temperature coefficient of the frequency of the surface acoustic wave filter. The thickness hsio of the insulating protective layer 32The relationship with the temperature coefficient of frequency of the surface acoustic wave filter is shown in fig. 5. As can be seen from FIG. 5, when the thickness hmet of the interdigital transducer electrode 2 is constant, the temperature coefficient of the acoustic surface wave filter with respect to frequency is determined by hsio2The value increases and decreases. Therefore, in one embodiment, the total thickness hsio of the insulating protection layer 32That is, the vertical thickness from the top A of the protrusion 31 to the surface of the insulating protective layer 3 bonded to the plane of the piezoelectric substrate 1 is 29 to 31% λ, preferably 30% λ.
Therefore, in the above embodiments, the surface acoustic wave filter effectively reduces the frequency temperature coefficient and the rayleigh wave spurious response of the surface acoustic wave filter by arranging the insulating protective layer 3 and arranging the plurality of protrusions distributed at intervals on the outer surface and by cooperating with the insulating protective layer 3, the interdigital transducer electrode 2, the piezoelectric substrate 1, and other components. By controlling and optimizing the size, shape and distribution spacing and position of the bumps 31, the frequency temperature coefficient of the surface acoustic wave filter can be significantly reduced, and the rayleigh wave spurious response of the surface acoustic wave filter can be effectively reduced.
Correspondingly, the embodiment of the invention also provides a preparation method of the acoustic surface wave filter with high temperature stability. The preparation method of the surface acoustic wave filter is combined with the figure 1, the process flow of the preparation method of the surface acoustic wave filter is shown in figure 6, and the preparation method comprises the following steps:
s01: preparing an interdigital transducer electrode 2 on a plane 11 of a piezoelectric substrate 1;
s02: depositing an insulating protective film layer on the plane 11 of the piezoelectric substrate 1 such that the insulating protective film layer covers the interdigital transducer electrodes 2;
s03: and etching the outer surface of the insulating protection film layer to form a plurality of bulges 31 distributed at intervals on the surface.
Specifically, the above stepsIn S01, the method for producing the interdigital transducer electrode 2 on the piezoelectric substrate 1 can be carried out according to the existing method for producing an interdigital transducer electrode. In the embodiment of the invention, the thickness of the interdigital transducer electrode 2 is preferably controlled to be 0.045-0.055 lambda, and preferably 0.05 lambda by controlling the process conditions of the method for preparing the interdigital transducer electrode 2. Wherein, the material for preparing the interdigital transducer electrode 2 can be any one of Al, Cu and Ti or Al and Cu alloy as described in the above. The material and thickness of the piezoelectric substrate 1 may be, as described above, the material LiTaO3In the step S02, the method for depositing the insulating protection film layer may be, but is not limited to, magnetron sputtering. When the insulating protective film layer is formed by magnetron sputtering deposition, the inventor finds that the change of the magnetron sputtering condition can cause the change of the elastic constant of the insulating protective film layer, thereby influencing the frequency temperature coefficient of the prepared surface acoustic wave filter.
In a specific embodiment, the material of the insulating protection film layer is SiO2I.e. deposition of SiO on the piezoelectric substrate 12After the film is formed, the film is aligned to 400-2000 cm-1The wave number of (A) was measured by FT-IR, deposited SiO2The FT-IR spectrum of the film shows three major peaks as shown in fig. 7. The relationship between the peak value and the molecular vibration mode was determined, including the rocking mode (ω 1: 450 cm)-1) Bending mode (ω 3: 800cm-1) And a stretching mode (ω 4: 1070cm-1)。
When different magnetron sputtering technological parameters are used for depositing SiO with the film thickness of 0.3 lambda2The films obtained omega 3 and omega 4 with different peak frequencies, the corresponding peak frequencies are summarized in Table 1, and the peak frequencies omega 3 and omega 4 are respectively 810.9-815.5cm-1And 1065.6-1079.2cm-1The range was varied and the elastic constant was varied by 7%. Through the above studies, when the sputtering process parameters are changed, the temperature coefficient of the elastic constant is changed, thereby causing the change of the TCF.
TABLE 1 SiO2FT-IR spectroscopy of deposited films
Thus, in one embodiment, magnetron sputtering is used to deposit the insulating protective film layer, in particular SiO2In the case of a thin film, the conditions of magnetron sputtering deposition are as follows: the radio frequency magnetic control discharge is controlled at 10-1～10-2Pa, the magnetic field intensity B of the magnetic control target surface is controlled to be between 30 and 50mT, and the electric field orthogonal to the magnetic field in the vacuum cavity is controlled to be between 500 and 700V. Therefore, the structure of the insulating protective film layer can be controlled and deposited by controlling the input process parameters of magnetron sputtering, and the TCF minimization of the surface acoustic wave filter is realized. For example, the temperature frequency coefficient is controlled to be changed between-20 ppm/DEG C and 0 ppm/DEG C.
In addition, after the insulating protective film layer is formed by deposition, the method also comprises the step of flattening the outer surface of the insulating protective film layer.
In the step S03, the insulating protection film layer formed by deposition is subjected to etching treatment to obtain the insulating protection layer 3 as described above and shown in fig. 1. The surface of the insulating and protecting layer 3 thus exhibits a plurality of projections 31 formed at intervals as shown in fig. 1. The size and distribution position of the protrusions 31 are as described above, and are not described herein for brevity.
In one embodiment, the etching process performed on the outer surface of the insulating protection film layer 3 includes the following steps:
(1) dividing the outer surface of the insulating protective film layer into an etching area and a non-etching area according to the design requirement of the distance between the adjacent protrusions 31, and covering an anti-etching protective film layer on the surface of the non-etching area; then, the product is processed
(2) And carrying out directional etching treatment on the etching area in the outer surface of the insulating protection film layer by adopting an inductive coupling plasma etching process.
In step (1), the protrusion 31 is formed in the non-etching region, that is, the region after the etching process. The protective film is covered to avoid etching the non-etching area during the etching process, so that the etching gas only etches the etching area to form the protrusions 31 with a plurality of profiles.
The process conditions for the directional etching treatment by the Inductively Coupled Plasma (ICP) etching process in step (2) are preferably as follows: the etchant used is SF6The passivating polymer-generating agent is C4F8Said SF6And C4F8Are alternately introduced into the etching chamber. ICP etching using SF6As an etchant, C4F8As a passivating polymer generator. SF6Under the action of inductive glow discharge, a mixture of multiple components such as ionized electrons, charged ions, atoms or atomic groups and the like can be mixed with the material SiO of the insulating protective film layer2If a chemical reaction occurs, introducing C into the reaction chamber during the passivation process4F8Gas, under the action of plasma, performs a plasma polymerization process which is highly isotropic and therefore occurs in SiO2The surface and the structure deep groove of the substrate are uniformly covered with a polymer protective film. During the subsequent etching process, the active gas in the reaction chamber is converted into SF6And is decomposed into SF+And SF-The electric field accelerates the positive ions, which increases the energy of the ions in the vertical direction, so that polymer regions parallel to the substrate surface are preferentially removed. With this high directionality, the silicon surface at the bottom of the deep trench is preferentially exposed and F-Reaction to form SiF4And thus etched.
In the aspect of etching depth control, the etching power and the longitudinal bias voltage in the process are increased to realize the control. In the ICP etching process, anisotropy is achieved by a combination of the etching action of reactive ions at the bottom surface of the trench and the inhibition of polymer at the sidewalls. The reactive ions can deflect under the action of a transverse electric field, and the reactive ions in the plasma are difficult to reach the etching surface along with the increase of the etching depth of the groove or the hole under the same power. Therefore, with the increase of the etching depth, the etching power and the longitudinal bias voltage in the process are increased in proportion, and the deflection effect of the transverse electric field is compensated to realize the deep groove etching.
In the aspect of etching angle control, the etching angle control is realized by adjusting the proportion of etching and protective gas. Experiments find that the main factor influencing the etching angle is the flow of the process gas, and SF is alternately introduced by adjusting6、C4F8The flow ratio of the two gases can achieve the purpose of controlling the etching angle. Reduction of SF6Flow and increase C4F8The flow can realize a positive V-shaped groove, and the ratio A/B of the top width A and the root width B of the protrusion 31 can be accurately controlled, so that the requirement on the optimized control of the surface appearance protrusion 31 of the insulating protection layer 3 can be met. Therefore, in an embodiment, the process conditions of the directional etching treatment are as follows:
the SF6The flow rate of the introduced air flow is 30-60 SCCM;
said C is4F8The flow rate of the introduced air flow is 30-60 SCCM;
the etching power is 300-;
the longitudinal bias is 30-35 VDC.
By controlling the directional etching treatment, the directional etching is realized, so that the size and the appearance of the bump 31 formed by etching are accurately controlled.
Therefore, the method for preparing the surface acoustic wave filter performs directional etching treatment on the outer surface of the insulating protective film layer to form the surface with the protrusions 31 distributed at intervals, so that the prepared surface acoustic wave filter has low frequency temperature coefficient and low rayleigh wave parasitic response, and can play a role in protection, so that the prepared surface acoustic wave filter has the advantages of stable working performance, long service life and the like. In addition, the preparation method has controllable process conditions, and can effectively ensure stable performance, high yield and low cost of the prepared acoustic surface wave filter with high temperature stability.
The surface wave filter based on the acoustic surface wave filter and the preparation method thereof has the advantages of low frequency temperature coefficient, low Rayleigh wave spurious response phenomenon, stable working performance, long service life and the like. Therefore, the acoustic surface filter plays a good role in the aspects of suppressing higher harmonics, image information, emission leakage signals, various parasitic clutter interferences and the like of the electronic information equipment, and can realize filtering of amplitude-frequency and phase-frequency characteristics with any required precision. For example, the upper limit frequency of the acoustic surface filter can be increased to 2.5 GHz-3 GHz. Thereby promoting wider application of the acoustic surface filter in the field of EMI resistance. As the Temperature Coefficient of Frequency (TCF) of conventional filters is typically about-45 ppm/deg.C, the acoustic surface filter drops above-4 ppm/deg.C, or even close to 0. And the Rayleigh wave spurious response is low and even disappears. Therefore, the surface acoustic wave filter can be widely applied to radar, mobile communication, channelized receivers and remote sensing and telemetry systems, so that the working performance and the working stability of corresponding devices are improved.
The present invention will now be described in further detail with reference to specific examples. In the following examples, "/" indicates lamination bonding.
1 structural embodiment of surface acoustic wave filter
Example 11
The embodiment provides an acoustic surface wave filter and a preparation method thereof. The structure of the surface acoustic wave filter is shown in fig. 1, and the structure of the surface acoustic wave filter is as follows: piezoelectric substrate 1/interdigital transducer electrode 2/insulating protective layer 3. Wherein the piezoelectric substrate 1 is LiTaO3The euler angle (0, theta, 0) theta is 38 degrees; the interdigital transducer electrode 2 is made of copper, and the thickness of the interdigital transducer electrode is 0.05 lambda; the insulating protective layer 3 is made of SiO2The total thickness of the interdigital transducer electrode is 0.3 lambda, a plurality of protrusions 31 distributed at intervals are formed on the outer surface of the insulating protection layer 3, the positions where the protrusions 31 are formed correspond to the single electrode of the interdigital transducer electrode 2, the distance between every two adjacent protrusions 31 is 0.6 mu m, the width A of the top of each protrusion 31 is smaller than the width B of the root of each protrusion, and the ratio SR of A to B is 0.38.
Example 12
The embodiment provides an acoustic surface wave filter and a preparation method thereof. The structure of the surface acoustic wave filter is shown in figure 1The structure of the acoustic surface wave filter is as follows: piezoelectric substrate 1/interdigital transducer electrode 2/insulating protective layer 3. Wherein the piezoelectric substrate 1 is LiTaO3The Euler angle (0, theta, 0) theta is 42 degrees; the interdigital transducer electrode 2 is made of Al and Cu alloy, and the thickness of the interdigital transducer electrode is 0.045 lambda; the insulating protective layer 3 is made of SiO2The total thickness of the interdigital transducer electrode is 0.31 lambda, a plurality of protrusions 31 distributed at intervals are formed on the outer surface of the insulating protection layer 3, the positions where the protrusions 31 are formed correspond to the single electrode of the interdigital transducer electrode 2, the distance between every two adjacent protrusions 31 is 0.8 mu m, the width A of the top of each protrusion 31 is smaller than the width B of the root of each protrusion, and the ratio SR of A to B is 0.3.
Example 13
The embodiment provides an acoustic surface wave filter and a preparation method thereof. The structure of the surface acoustic wave filter is shown in fig. 1, and the structure of the surface acoustic wave filter is as follows: piezoelectric substrate 1/interdigital transducer electrode 2/insulating protective layer 3. Wherein the piezoelectric substrate 1 is LiTaO3Euler angles (0, theta, 0) theta of 41 DEG; the interdigital transducer electrode 2 is made of Al, and the thickness of the interdigital transducer electrode is 0.055 lambda; the insulating protective layer 3 is made of SiO2The total thickness of the electrode is 0.29 lambda, a plurality of protrusions 31 are formed on the outer surface of the insulating protection layer 3 at intervals, the positions where the protrusions 31 are formed correspond to the single electrodes of the interdigital transducer electrodes 2, the distance between adjacent protrusions 31 is the same as the distance between adjacent electrodes (the electrodes substantially form interdigital electrode metal strips), the width a of the top of each protrusion 31 is smaller than the width B of the root, and the ratio SR of the width a to the width B is 0.4.
2 method for manufacturing surface acoustic wave filter
Example 21
This example provides a method of making the surface acoustic wave filter of example 11. The preparation method comprises the following steps:
s1: in LiTaO3Preparing an interdigital transducer copper electrode 2 on a plane 11 of a piezoelectric substrate 1; controlling the thickness of the interdigital transducer copper electrode 2 to be 0.05% lambda more preferably;
s2: in the plane 1 of the piezoelectric substrate 11 deposition of SiO by magnetron sputtering2An insulating protective film layer, and enabling the insulating protective film layer to cover the interdigital transducer electrode 2; wherein the total thickness is controlled to be 0.3 lambda, and the process condition of the magnetron sputtering process is that the radio frequency magnetron discharge is controlled to be 10-1～10-2Pa, controlling the magnetic field intensity B of the magnetic control target surface to be 40mT, and controlling the electric field orthogonal to the magnetic field in the vacuum cavity to be 600V;
s03: performing ICP etching treatment on the outer surface of the insulating protection film layer to form a plurality of protrusions 31 distributed at intervals on the surface; wherein the etching agent used for the ICP etching treatment is SF6The passivating polymer-generating agent is C4F8Said SF6And C4F8Alternately introducing into an etching chamber; and the process conditions of the directional etching treatment are as follows:
the SF6The flow rate of the introduced gas flow is 45 SCCM;
said C is4F8The flow rate of the introduced gas flow is 45 SCCM;
the etching power is 350W;
the longitudinal bias is 30 VDC.
Example 22
This example provides a method of making the surface acoustic wave filter of example 12. The preparation method comprises the following steps:
s1: in LiTaO3Preparing an interdigital transducer Al and Cu alloy electrode 2 on a plane 11 of a piezoelectric substrate 1;
s2: depositing SiO on the plane 11 of the piezoelectric substrate 1 by adopting a magnetron sputtering process2An insulating protective film layer, and enabling the insulating protective film layer to cover the interdigital transducer electrode 2; wherein, the technological condition of the magnetron sputtering technology is that the radio frequency magnetron discharge is controlled at 10-1～10-2Pa, controlling the magnetic field intensity B of the magnetic control target surface to be 30mT, and controlling the electric field orthogonal to the magnetic field in the vacuum cavity to be 500V;
s03: performing ICP etching treatment on the outer surface of the insulating protection film layer to form a plurality of protrusions 31 distributed at intervals on the surface; wherein the ICP is engravedThe etchant used for etching is SF6The passivating polymer-generating agent is C4F8Said SF6And C4F8Alternately introducing into an etching chamber; and the process conditions of the directional etching treatment are as follows:
the SF6The flow rate of the introduced gas flow is 60 SCCM;
said C is4F8The flow rate of the introduced gas flow is 30 SCCM;
the etching power is 400W;
the longitudinal bias is 30 VDC.
Example 23
This example provides a method of making the surface acoustic wave filter of example 13. The preparation method comprises the following steps:
s1: in LiTaO3Preparing an interdigital transducer Al electrode 2 on a plane 11 of the piezoelectric substrate 1;
s2: depositing SiO on the plane 11 of the piezoelectric substrate 1 by adopting a magnetron sputtering process2An insulating protective film layer, and enabling the insulating protective film layer to cover the interdigital transducer electrode 2; wherein, the technological condition of the magnetron sputtering technology is that the radio frequency magnetron discharge is controlled at 10-1～10-2Pa, controlling the magnetic field intensity B of the magnetic control target surface at 50mT, and controlling the electric field orthogonal to the magnetic field in the vacuum cavity at 700V;
s03: performing ICP etching treatment on the outer surface of the insulating protection film layer to form a plurality of protrusions 31 distributed at intervals on the surface; wherein the etching agent used for the ICP etching treatment is SF6The passivating polymer-generating agent is C4F8Said SF6And C4F8Alternately introducing into an etching chamber; and the process conditions of the directional etching treatment are as follows:
the SF6The flow rate of the introduced gas flow is 30 SCCM;
said C is4F8The flow rate of the introduced gas flow is 60 SCCM;
the etching power is 300W;
the longitudinal bias is 35 VDC.
Comparative example
Conventional surface acoustic wave filters are commercially available.
3. Acoustic surface wave filter related performance test
The surface acoustic wave filters provided in examples 11 to 13 and the commercially available conventional surface acoustic wave filter provided in the comparative example were subjected to the following correlation performance tests, respectively, and the results were as shown in the following table 1:
TABLE 1
In addition, examples 12 and 13 provide surface acoustic wave filters that are similar to the performance test results in table 1. Therefore, as can be seen from the results of the correlation performance tests in table 1, the surface acoustic wave filter of the present embodiment has a low temperature coefficient of frequency and a low rayleigh wave spurious response, and has stable operation performance and a long service life.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. A high temperature stable surface acoustic wave filter, comprising: comprises that
The piezoelectric substrate at least has a plane;
an interdigital transducer electrode fixedly disposed on the plane of the piezoelectric substrate;
an insulating protective layer having two opposite surfaces, one of which is bonded on the plane of the piezoelectric substrate in a laminated manner and covers the interdigital transducer electrodes; the other surface is provided with a plurality of bulges distributed at intervals.
2. The surface acoustic wave filter of claim 1, wherein: the width of the top of the single protrusion is smaller than that of the root of the single protrusion, and the side face of the single protrusion is an inclined plane.
3. The surface acoustic wave filter of claim 2, wherein: the ratio of the width of the tip to the width of the root of a single protrusion is 0.3-0.4.
4. The acoustic surface wave filter according to any one of claims 1 to 3, wherein: the distance between every two adjacent protrusions is 0.3-0.8 mu m, and the distance between every two adjacent protrusions is consistent with the distance between every two adjacent metal interdigital strips; and/or
The height of the protrusions is 1.0-1.1 μm; and/or
The position where a single bump is formed corresponds positively to a single electrode of the interdigital transducer electrode.
5. The acoustic surface wave filter according to any one of claims 1 to 3, wherein: the insulating protective layer is made of at least one of silicon dioxide and silicon nitride;
the interdigital transducer electrode is made of any one of Al, Cu and Ti or Al and Cu alloy;
the piezoelectric substrate is made of LiTaO3。
6. The surface acoustic wave filter of claim 5, wherein: the total thickness of the insulation protective layer is 0.29-0.31 lambda, and lambda is the acoustic wave wavelength;
the thickness of the interdigital transducer electrode is 0.045-0.055 lambda;
the Euler angle (0, theta, 0) theta of the material of the piezoelectric substrate is 380、410、420Any value of (1).
7. The method for manufacturing the acoustic surface wave filter according to any one of claims 1 to 6, comprising the steps of:
preparing interdigital transducer electrodes on one plane of a piezoelectric substrate;
depositing an insulating protective film layer on the plane of the piezoelectric substrate, and enabling the insulating protective film layer to cover the interdigital transducer electrode;
and etching the outer surface of the insulating protection film layer to form a plurality of bulges distributed at intervals on the surface.
8. The method of claim 7, wherein: the etching treatment of the outer surface of the insulating protection film layer comprises the following steps:
dividing the outer surface of the insulating protective film layer into an etching area and a non-etching area according to the design requirement of the distance between the adjacent bulges, and covering an anti-etching protective film layer on the surface of the non-etching area; then, the product is processed
And carrying out directional etching treatment on the etching area in the outer surface of the insulating protection film layer by adopting an inductive coupling plasma etching process.
9. The method of claim 8, wherein: the etchant used for the directional etching treatment is SF6The passivating polymer-generating agent is C4F8Said SF6And C4F8Alternately introducing into an etching chamber; and the process conditions of the directional etching treatment are as follows:
the SF6The flow rate of the introduced air flow is 30-60 SCCM;
said C is4F8The flow rate of the introduced air flow is 30-60 SCCM;
the etching power is 300-;
the longitudinal bias is 30-35 VDC.
10. Use of the surface acoustic wave filter according to any of claims 1-6 in radar, mobile communication, channelized receivers, telemetry systems.
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|---|---|---|---|---|
| CN112134539A (en) * | 2020-08-19 | 2020-12-25 | 合肥先微企业管理咨询合伙企业(有限合伙) | Radio frequency piezoelectric resonator with adjustable reflection cavity and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07226541A (en) * | 1994-02-09 | 1995-08-22 | Brother Ind Ltd | Multilayered piezoelectric element |
| US5923231A (en) * | 1994-08-05 | 1999-07-13 | Kinseki Limited | Surface acoustic wave device with an electrode insulating film and method for fabricating the same |
| JP2004254291A (en) * | 2003-01-27 | 2004-09-09 | Murata Mfg Co Ltd | Acoustic surface wave device |
| JP2005348139A (en) * | 2004-06-03 | 2005-12-15 | Murata Mfg Co Ltd | Elastic wave device and method for manufacturing the same |
| CN101379700A (en) * | 2006-02-16 | 2009-03-04 | 松下电器产业株式会社 | Surface acoustic wave device, surface acoustic wave filter employing same and antenna duplexer, and electronic apparatus employing same |
| JP2015073308A (en) * | 2014-11-26 | 2015-04-16 | スカイワークス・パナソニック フィルターソリューションズ ジャパン株式会社 | Elastic wave device |
| CN210986061U (en) * | 2019-08-05 | 2020-07-10 | 北京中讯四方科技股份有限公司 | Acoustic surface wave filter with high temperature stability |
-
2019
- 2019-08-05 CN CN201910716397.7A patent/CN110601672A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07226541A (en) * | 1994-02-09 | 1995-08-22 | Brother Ind Ltd | Multilayered piezoelectric element |
| US5923231A (en) * | 1994-08-05 | 1999-07-13 | Kinseki Limited | Surface acoustic wave device with an electrode insulating film and method for fabricating the same |
| JP2004254291A (en) * | 2003-01-27 | 2004-09-09 | Murata Mfg Co Ltd | Acoustic surface wave device |
| JP2005348139A (en) * | 2004-06-03 | 2005-12-15 | Murata Mfg Co Ltd | Elastic wave device and method for manufacturing the same |
| CN101379700A (en) * | 2006-02-16 | 2009-03-04 | 松下电器产业株式会社 | Surface acoustic wave device, surface acoustic wave filter employing same and antenna duplexer, and electronic apparatus employing same |
| JP2015073308A (en) * | 2014-11-26 | 2015-04-16 | スカイワークス・パナソニック フィルターソリューションズ ジャパン株式会社 | Elastic wave device |
| CN210986061U (en) * | 2019-08-05 | 2020-07-10 | 北京中讯四方科技股份有限公司 | Acoustic surface wave filter with high temperature stability |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112134539A (en) * | 2020-08-19 | 2020-12-25 | 合肥先微企业管理咨询合伙企业(有限合伙) | Radio frequency piezoelectric resonator with adjustable reflection cavity and preparation method thereof |
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