Surface acoustic wave filter based on periodic ferroelectric domain and implementation method thereof

Abstract

The invention discloses a surface acoustic wave filter based on a periodic ferroelectric domain and an implementation method thereof. A ferroelectric domain polarizer is adopted to enable a ferroelectric semiconductor film to be subjected to polarization overturning, a plurality of concentric annular narrow ferroelectric domains which are alternately arranged in ferroelectric polarization directions are formed on the ferroelectric semiconductor film below the position between every two adjacent polarized electrodes, and a periodic ferroelectric domain film is obtained; a sheet-shaped filter input electrode is formed on the periodic ferroelectric domain film, and when the same-phase voltage is received, ferroelectric domains with opposite ferroelectric polarization directions automatically generate oscillation with opposite directions to form surface acoustic wave standing waves; the working frequency of the filter is determined by the width of the narrow ferroelectric domain, the width of the narrow ferroelectric domain is modulated by the voltage and frequency of the applied amplitude modulation alternating current, and the narrow ferroelectric domain with small width is easy to prepare, so that the working frequency of the filter is not limited, and the filter can work at a higher frequency; the method is applied to the fields of radio frequency communication, 6G network transmission, high-precision radar, remote sensing monitoring and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor device preparation, in particular to a surface acoustic wave filter based on periodic ferroelectric domains and an implementation method thereof. BACKGROUND

[0002] The surface acoustic wave filter is an important device in wireless communication technology. With the development of 5G communication technology and 6G communication technology, there is an urgent need for a high-frequency surface acoustic wave filter that is easy to prepare and stable in performance. The traditional surface acoustic wave filter inputs a radio frequency signal to a piezoelectric semiconductor film through an interdigital electrode, and then forms a surface acoustic wave on the surface of the piezoelectric semiconductor film. The working frequency of the traditional surface acoustic wave filter is inversely proportional to the minimum line width of the interdigital electrode, so the working frequency of this type of device is limited by the processing precision of the interdigital electrode and it is difficult to exceed 3GHz. In addition, reducing the line width of the interdigital electrode in order to pursue higher working frequency will result in reduced device stability and power tolerance.

[0003] Ferroelectric material is a kind of piezoelectric material with spontaneous polarization characteristics. The ferroelectric semiconductor film not only has piezoelectric effect, but also spontaneously polarizes without external electric field. The direction of this spontaneous polarization can be reversed and reoriented under the action of an external electric field. In the ferroelectric semiconductor film, the regions where the spontaneous ferroelectric polarization directions are consistent are called ferroelectric domains. By applying a designed external electric field on the surface of the ferroelectric semiconductor film, a special ferroelectric domain structure can be formed on the surface and inside the film. If the piezoelectric semiconductor film in the traditional surface acoustic wave filter can be replaced by a ferroelectric semiconductor film with a special ferroelectric domain structure, and the electrode structure of the surface acoustic wave filter is redesigned, it will have the opportunity to completely abandon the traditional interdigital electrode structure and break the limitation of the interdigital electrode line width on the working frequency of the device. SUMMARY

[0004] In view of the problems existing in the prior art, the present application provides an implementation method of a surface acoustic wave filter based on periodic ferroelectric domains.

[0005] An object of the present application is to provide an implementation method of a surface acoustic wave filter based on periodic ferroelectric domains.

[0006] The implementation method of the surface acoustic wave filter based on periodic ferroelectric domains of the present application comprises the following steps: 1) Preparation of ferroelectric domain polarizer: The ferroelectric domain polarizer comprises a plurality of concentric ring-shaped polarization electrodes; adjacent polarization electrodes are separated by an insulating layer; 2) Preparation of periodic ferroelectric domain film: Evaporating a bottom electrode on the back of the ferroelectric semiconductor film; The ferroelectric semiconductor thin film is inverted on the ferroelectric domain polarizer, that is, the front surface of the ferroelectric semiconductor thin film faces down and directly faces the concentric ring-shaped polarization electrode; the bottom electrode of the ferroelectric semiconductor thin film is connected to the ground; and each polarization electrode is connected in parallel to an external power supply through a polarization electrode lead. The external power supply applies an amplitude-modulated alternating current to the surface of the ferroelectric semiconductor thin film through the polarization electrode, and under the action of the amplitude-modulated alternating current, the front surface of the ferroelectric semiconductor thin film is polarized and flipped to a set depth, and the ferroelectric semiconductor thin film below the adjacent two polarization electrodes forms a plurality of narrow ferroelectric domains arranged in concentric rings and having alternating ferroelectric polarization directions, thereby obtaining a periodic ferroelectric domain thin film; the width of the narrow ferroelectric domain is in the order of microns. 3) Preparing a groove: A circular groove is prepared on the front surface of the periodic ferroelectric domain thin film, and the depth of the circular groove is less than the depth of the formed ferroelectric domain. In the circular groove, a cylindrical groove is formed at the center of the circular groove, and an annular groove is formed at the edge of the circular groove, and the cylindrical groove and the annular groove jointly constitute a reflection groove. The remaining part forms an annular periodic ferroelectric domain thin film. 4) Preparing an electrode: A filter output electrode and a filter input electrode are respectively formed on the annular periodic ferroelectric domain thin film; the filter output electrode is an annular interdigital electrode and is located on the inner side; a plurality of center-symmetric sheet-shaped filter input electrodes are formed between the filter output electrode and the annular groove of the reflection groove, and the width of the filter input electrode is in the order of centimeters. 5) Sealing and packaging: The surface of the above structure is packaged by using a packaging shell. 6) Generating a surface acoustic wave standing wave for filtering: A radio frequency signal is input from the filter input electrode, a surface acoustic wave standing wave is generated on the surface of the periodic ferroelectric domain thin film, the radio frequency signal is filtered, and the filter output electrode is connected to an external circuit to send the filtered radio frequency signal.

[0007] In step 1), the material of the polarization electrode is metal, and the material of the insulating layer is insulating material; the width of each polarization electrode is the same and is an integer multiple of the wavelength of the surface acoustic wave corresponding to the working frequency of the filter, so as to generate resonance amplification enhancement of the surface acoustic wave, improve the energy conversion efficiency during the working of the filter, reduce the energy consumption, and thus improve the quality factor of the device; the width of the insulating layer, that is, the spacing between adjacent polarization electrodes, is the same and is 10-30 microns, and is an integer multiple of the width of the polarization electrode. The thickness of the polarization electrode is 20-500 nm. The planar size of the ferroelectric domain polarizer is a circle with a diameter of 2-5 centimeters, which is consistent with the size of a standard wafer.

[0008] In step 2), the thickness of the bottom electrode is 150-500 nm, and the material is metal.

[0009] The frequency of the amplitude-modulated alternating current is constant, but the peak voltage of the alternating current varies; the maximum value of the peak voltage ranges from 31 to 35 V, and the minimum value ranges from 0 to 10 V, and the frequency ranges from 10 kHz to 20 kHz.

[0010] The peak voltage of the amplitude-modulated alternating current gradually decreases, and a periodic electric field is formed inside the ferroelectric semiconductor thin film; the polarization reversal voltage of the ferroelectric semiconductor is a rated value, and the peak voltage of the amplitude-modulated alternating current is gradually reduced, so that the polarization of the ferroelectric semiconductor thin film from the front surface to a set depth is reversed, and a ferroelectric domain is formed; a wide ferroelectric domain in the form of a ring with the same width as the polarization electrode is formed in the ferroelectric semiconductor thin film directly below the polarization electrode, the polarization directions of the wide ferroelectric domains in each concentric ring are consistent, and the ferroelectric semiconductor thin film directly below the adjacent two polarization electrodes forms periodically alternating narrow ferroelectric domains in the form of rings with opposite ferroelectric polarization directions, the narrow ferroelectric domains are in the form of multiple concentric rings, and the ferroelectric polarization directions of the adjacent two rings of narrow ferroelectric domains are opposite; the width of the narrow ferroelectric domain is half of the wavelength of the surface acoustic wave corresponding to the working frequency of the filter, and the thickness and width of the ring-shaped narrow ferroelectric domain with the same ferroelectric polarization direction are modulated by the voltage and frequency of the applied amplitude-modulated alternating current; the width of the narrow ferroelectric domain wherein is a threshold voltage constant of the ferroelectric semiconductor thin film material, is the frequency of the amplitude-modulated alternating current, is the rate of change of the peak voltage of the amplitude-modulated alternating current; the depth of the narrow ferroelectric domain wherein and is a threshold voltage constant and a frequency response constant of the ferroelectric semiconductor thin film material, is the maximum value of the peak voltage of the amplitude-modulated alternating current, is a kinetic index of 1.7, is the voltage application time of the amplitude-modulated alternating current, which is related to the frequency and voltage ; the thickness of the ferroelectric domain formed by the ferroelectric semiconductor thin film is 100-300 nm, the greater the voltage, the deeper the thickness of the ferroelectric domain formed, the polarization reversal depth is directly related to the voltage of the amplitude-modulated alternating current, and the width of the polarization reversal is directly related to the frequency of the amplitude-modulated alternating current; by setting the voltage and frequency of the amplitude-modulated alternating current, a periodic ferroelectric domain thin film with a set period and width is prepared on the ferroelectric semiconductor thin film. The width of such ferroelectric domains is not limited by the width of the polarization electrode, but is controlled by the voltage and frequency of the amplitude-modulated alternating current, so that periodic ferroelectric domains with a line width of nm level can be formed.

[0011] In step 3), the depth of the circular groove is less than the depth of the ferroelectric domain, the depth of the circular groove is 30-80 nm, and the thickness of the remaining ferroelectric domain is 20-270 nm; the depth of the reflection groove is 300-500 nm, which is greater than the depth of the circular groove.

[0012] In step 4), the filter output electrode and the filter input electrode are made of metal. Each filter input electrode is in the shape of a sector or a partial sector, and each filter input electrode is centrally symmetric and covers as much of the surface of the periodic ferroelectric domain film as possible. A plurality of centrally symmetric filter input electrodes are used instead of a whole ring-shaped electrode to prevent the underlying ferroelectric domain from being damaged due to excessive stress, which causes the periodic ferroelectric domain film to break. A gap is left between adjacent filter input electrodes, and the distance is 500-2000 μm to reduce the stress on the semiconductor film when the filter is working.

[0013] In step 5), the packaging shell is filled with inert gas; the packaging shell is made of aluminum oxide ceramic, epoxy resin, or iron-nickel-cobalt alloy; the packaging shell is perforated at the corresponding positions of the filter output electrode and the filter input electrode to lead out the filter output electrode and the plurality of parallel filter input electrodes.

[0014] In step 6), the conventional filter input electrode is an interdigital electrode formed on a piezoelectric material, an alternating radio frequency voltage signal is input to the piezoelectric material, the periodic vibration of the piezoelectric material generates a surface acoustic wave, and the working frequency is limited; the filter input electrode of the present application is a sheet-shaped filter input electrode formed on a periodic ferroelectric domain film, the characteristic width of the filter input electrode is 1-2 cm, the characteristic width of the ferroelectric domain is 2 μm, the difference is 1000 times, the planar size of the sheet-shaped filter input electrode is much larger than the width of the ring-shaped narrow ferroelectric domain, and the periodically arranged narrow ferroelectric domains with opposite polarization directions automatically generate oscillations in opposite directions when receiving the same phase voltage, forming a surface acoustic wave standing wave, and the wavelength of the surface acoustic wave is twice the width of the ferroelectric domain L ; the working frequency of the filter is consistent with the surface acoustic wave, which is determined by the width of the periodic narrow ferroelectric domain, the signal with the same frequency as the working frequency of the filter is amplified and other signals are suppressed, thereby outputting the filtered radio frequency signal with the same frequency as the working frequency of the filter; the working frequency of the filter of the present application is consistent with the surface acoustic wave, which is determined by the width of the periodic narrow ferroelectric domain, and the preparation process of the periodic narrow ferroelectric domain is much simpler than that of the interdigital electrode, and the higher the working frequency, the narrower the width of the narrow ferroelectric domain, the width of the narrow ferroelectric domain is modulated by the voltage and frequency of the applied amplitude-modulated alternating current, and the narrow ferroelectric domain with small width is easy to prepare, while the corresponding width of the conventional interdigital electrode is extremely difficult to prepare, therefore the working frequency of the filter of the present application is not limited, and the filter can work at a higher frequency.

[0015] Another object of the present application is to provide a surface acoustic wave filter based on periodic ferroelectric domains.

[0016] The surface acoustic wave filter based on periodic ferroelectric domains of the present application comprises a bottom electrode, a periodic ferroelectric domain film, a reflection groove, a filter output electrode, a filter input electrode and a packaging shell; wherein the bottom electrode is evaporated on the back of the ferroelectric semiconductor film; a plurality of narrow ferroelectric domains in concentric ring shape and arranged alternately in the direction of ferroelectric polarization are formed on the front of the ferroelectric semiconductor film by a ferroelectric domain polarizer to obtain the periodic ferroelectric domain film; a circular groove is prepared on the front of the periodic ferroelectric domain film, the depth of the circular groove is less than the depth of the ferroelectric domains; a cylindrical groove is formed in the center of the circular groove and an annular groove is formed at the edge of the circular groove to jointly constitute the reflection groove, and the remaining part forms an annular periodic ferroelectric domain film; the filter output electrode and the filter input electrode are respectively formed on the annular periodic ferroelectric domain film, the filter output electrode is an annular interdigital electrode located on the inner side, and a plurality of sheet-shaped filter input electrodes are formed between the filter output electrode and the annular groove of the reflection groove in central symmetry; the surface of the above structure is packaged by the packaging shell; a radio frequency signal is input from the filter input electrode, a surface acoustic wave standing wave is generated on the surface of the periodic ferroelectric domain film to filter the radio frequency signal, and the filter output electrode is connected to an external circuit to send the filtered radio frequency signal.

[0017] Advantages of the present application: The ferroelectric domain polarizer is used in the present application to make the ferroelectric semiconductor film polarize and flip to form a plurality of narrow ferroelectric domains in concentric ring shape and arranged alternately in the direction of ferroelectric polarization to obtain the periodic ferroelectric domain film; the sheet-shaped filter input electrode is formed on the periodic ferroelectric domain film to receive in-phase voltage, the ferroelectric domains with opposite polarization directions automatically generate oscillation in the opposite direction to form a surface acoustic wave standing wave; the working frequency of the filter is not limited and can work at a higher frequency; the present application is applied to the fields of radio frequency communication and 6G network transmission, high-precision radar and remote sensing monitoring, etc. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A top view of the ferroelectric domain polarizer of one embodiment of the surface acoustic wave filter based on periodic ferroelectric domains of the present application; Figure 2 A sectional view of preparing the periodic ferroelectric domain film of one embodiment of the surface acoustic wave filter based on periodic ferroelectric domains of the present application; Figure 3 A top view of the periodic ferroelectric domain film of one embodiment of the surface acoustic wave filter based on periodic ferroelectric domains of the present application; Figure 4A flow chart for preparing an embodiment of the periodic ferroelectric domain based surface acoustic wave filter of the present application, wherein (a)-(e) are cross-sectional views of respective steps; Figure 5 A top view of the filter input and output electrodes of an embodiment of the periodic ferroelectric domain based surface acoustic wave filter of the present application; Figure 6 A cross-sectional view of an embodiment of the periodic ferroelectric domain based surface acoustic wave filter of the present application; Figure 7 A top view of an embodiment of the periodic ferroelectric domain based surface acoustic wave filter of the present application. DETAILED DESCRIPTION

[0019] The present application is further described below in connection with the accompanying drawings and a specific embodiment.

[0020] In this embodiment, the surface acoustic wave wavelength corresponding to the operating frequency of the filter is 2 μm, the operating frequency is 5 GHz, and the acoustic velocity of the ferroelectric semiconductor thin film is 10000 m / s.

[0021] The implementation method of the periodic ferroelectric domain based surface acoustic wave filter of this embodiment includes the following steps: 1) Preparing a ferroelectric domain polarizer: A concentric ring-shaped polarization electrode pattern is drawn on the ceramic insulating layer by photolithography, and then a gold polarization electrode is made by evaporation; adjacent polarization electrodes are separated by an insulating layer of the same width of 60 μm, as shown in Figure 1 The plane where the polarization electrodes are located is the XY plane, the width of each polarization electrode is the same, 20 μm, the thickness is 200 nm, the material is Ti / Al / Ni / Au multilayer alloy, and the diameter is 4 inches; 2) Preparing a periodic ferroelectric domain thin film: A 200 nm thick gold or titanium bottom electrode is evaporated on the back of a 4 inch diameter sapphire-based aluminum nitride ferroelectric semiconductor thin film, as shown in Figure 4 (a); The ferroelectric semiconductor thin film is inverted on the ferroelectric domain polarizer, i.e. the front of the ferroelectric semiconductor thin film is downwardly facing the ring-shaped and concentric polarization electrodes; the bottom electrode of the ferroelectric semiconductor thin film is connected to the ground; each polarization electrode is connected in parallel to an external power supply through a polarization electrode lead, as shown in Figure 2 The XZ plane is perpendicular to the plane where the polarization electrodes are located; The external power supply applies an amplitude-modulated alternating current to the surface of the ferroelectric semiconductor thin film through the polarization electrodes, with a maximum voltage of 30 V and a frequency of 10 kHz; under the action of the amplitude-modulated alternating current, the front of the ferroelectric semiconductor thin film is polarized and flipped to a depth of 200 nm, obtaining a periodic ferroelectric domain thin film, as shown inFigure 4 (b) shown; the ferroelectric semiconductor thin film under the polarization electrode forms a concentric ring-shaped wide ferroelectric domain with the same width as the polarization electrode, the polarization direction of each concentric ring-shaped wide ferroelectric domain under the polarization electrode is consistent, and the ferroelectric semiconductor thin film under the adjacent two polarization electrodes forms periodically arranged concentric ring-shaped positive narrow ferroelectric domains and negative narrow ferroelectric domains, the narrow ferroelectric domains with the same ferroelectric polarization direction are multiple concentric rings, and the ferroelectric polarization directions of the adjacent two ring-shaped narrow ferroelectric domains are opposite, as shown in Figure 3 The plane where the periodic ferroelectric domain thin film is located is the XY plane; the width of the narrow ferroelectric domain is 1 μm, which is half of the wavelength of the surface acoustic wave corresponding to the working frequency of the filter; 3) Preparation of grooves: A 50 nm deep circular groove is prepared on the front surface of the periodic ferroelectric domain thin film; In the circular groove, a cylindrical groove is formed at the center of the circular groove, and an annular groove is formed at the edge of the circular groove, and the cylindrical groove and the annular groove together constitute a reflection groove with a depth of 300 nm, as shown in Figure 4 (c) shown; The remaining part of the circular groove forms an annular periodic ferroelectric domain thin film with a thickness of 150 nm; 4) Preparation of electrodes: A filter output electrode and a filter input electrode are formed on the annular periodic ferroelectric domain thin film; the filter output electrode is a ring-shaped interdigital electrode located on the inner side with a width of 0.5 μm, a thickness of 200 nm, and a spacing of 0.5 μm; a plurality of central-symmetric sheet-shaped filter input electrodes are formed between the filter output electrode and the annular groove of the reflection groove, which are partially annular in shape, each filter input electrode is central-symmetric and covers as much of the surface of the periodic ferroelectric domain thin film as possible, with a width of 3 cm and a thickness of 200 nm, as shown in Figure 4 (d) shown; the top view of the filter output electrode and the filter input electrode is shown in Figure 5 ; 5) Sealing and packaging: The surface of the above structure is packaged with a packaging shell, which has a diameter of 4 inches, a thickness of 500 μm, and is made of alumina ceramic, as shown in Figure 4 (e) shown; the high packaging shell is filled with inert gas; the packaging shell is opened at the corresponding positions of the filter output electrode and the filter input electrode with a diameter of 20 μm and a depth of 500 μm, and the filter output electrode and the filter input electrode are connected and led out; the cross-sectional view of the surface acoustic wave filter after packaging is shown in Figure 6 ; Figure 7 ; 6) Generation of surface acoustic wave standing wave for filtering: Radio frequency signal is input from the filter input electrode, the planar size of the sheet filter input electrode is much larger than the width of the ring-shaped narrow ferroelectric domain, the periodically and alternately arranged narrow ferroelectric domains with opposite ferroelectric polarization directions automatically generate oscillation with opposite directions when receiving the same phase voltage, forming a surface acoustic wave standing wave, the wavelength of the surface acoustic wave is twice the width of the narrow ferroelectric domain L ; the working frequency of the filter is consistent with the surface acoustic wave, the signal consistent with the working frequency of the filter in the input radio frequency signal is amplified and other signals are suppressed, thereby filtering the radio frequency signal, outputting the filtered radio frequency signal consistent with the working frequency of the filter, the filter output electrode is connected to an external circuit, and the filtered radio frequency signal is sent; the working frequency of the filter is not limited, and the filter can work at a higher frequency.

[0022] Finally, it should be noted that the purpose of the disclosed embodiments is to help further understand the present application, but those skilled in the art can understand that various replacements and modifications are possible without departing from the spirit and scope of the present application and the appended claims. Therefore, the present application should not be limited to the disclosed content, and the scope of protection claimed by the present application is defined by the scope defined by the claims.

Claims

1. A method of implementing a surface acoustic wave filter based on periodic ferroelectric domains, characterized in that, The implementation method comprises the following steps: 1) preparing a ferroelectric domain polarizer: The ferroelectric domain polarizer comprises a plurality of concentric ring-shaped polarization electrodes; adjacent polarization electrodes are spaced by an insulating layer; 2) preparing a periodic ferroelectric domain film: A bottom electrode is evaporated on the back of the ferroelectric semiconductor film; The ferroelectric semiconductor film is inverted on the ferroelectric domain polarizer; the bottom electrode of the ferroelectric semiconductor film is connected to ground, and each polarization electrode is connected in parallel to an external power supply; An amplitude-modulated alternating current is applied to the surface of the ferroelectric semiconductor film by the polarization electrode, the front of the ferroelectric semiconductor film is polarized and flipped, and the ferroelectric semiconductor film below adjacent polarization electrodes forms a plurality of concentric ring-shaped narrow ferroelectric domains with alternating ferroelectric polarization directions, thereby obtaining a periodic ferroelectric domain film; 3) preparing a groove: A circular groove is prepared on the front of the periodic ferroelectric domain film; a cylindrical groove is formed in the center of the circular groove, and an annular groove is formed at the edge, together forming a reflection groove; The remaining part forms an annular periodic ferroelectric domain film; 4) preparing an electrode: A filter output electrode and a filter input electrode are formed on the annular periodic ferroelectric domain film, respectively; the filter output electrode is located on the inner side; a plurality of center-symmetric sheet-shaped filter input electrodes are formed between the filter output electrode and the annular groove of the reflection groove; 5) sealing and packaging: The surface of the above structure is packaged with a packaging shell; 6) generating a surface acoustic wave standing wave for filtering: A radio frequency signal is input from the filter input electrode, a surface acoustic wave standing wave is generated on the surface of the periodic ferroelectric domain film, the radio frequency signal is filtered, the filter output electrode is connected to an external circuit, and the filtered radio frequency signal is transmitted.

2. The implementation method of claim 1, wherein, In step 1), the width of each polarization electrode is the same, and is an integer multiple of the wavelength of the surface acoustic wave corresponding to the working frequency of the filter; the width of each insulating layer is the same, and is an integer multiple of the width of the polarization electrode.

3. The implementation method of claim 1, wherein, In step 2), the thickness of the bottom electrode is 150-500 nm, and the material is metal.

4. The implementation method of claim 1, wherein, In step 2), the frequency of the amplitude-modulated alternating current is 10-20 kHz.

5. The implementation method of claim 1, wherein, In step 2), the ferroelectric semiconductor film directly below the polarization electrode forms a ring-shaped wide ferroelectric domain with the same width as the polarization electrode, and the polarization direction of each concentric ring-shaped wide ferroelectric domain is consistent; the adjacent wide ferroelectric domains are periodically arranged with opposite polarization directions; the width of the narrow ferroelectric domain is half of the wavelength of the surface acoustic wave corresponding to the working frequency of the filter, and the thickness and width of the ring-shaped narrow ferroelectric domain with the same polarization direction are modulated by the voltage and frequency of the applied amplitude-modulated alternating current.

6. The implementation method of claim 1, wherein, In step 3), the depth of the circular groove is 30-80 nm; the depth of the reflection groove is 300-500 nm.

7. A surface acoustic wave filter based on periodic ferroelectric domains, characterized in that, The surface acoustic wave filter comprises a bottom electrode, a periodic ferroelectric domain film, a reflecting groove, a filter output electrode, a filter input electrode and a packaging shell; wherein the bottom electrode is evaporated on the back of the ferroelectric semiconductor film; a plurality of narrow ferroelectric domains in concentric ring shape and with the ferroelectric polarization direction arranged alternately are formed on the front of the ferroelectric semiconductor film by a ferroelectric domain polarizer, so as to obtain the periodic ferroelectric domain film; a circular groove is prepared on the front of the periodic ferroelectric domain film; a cylindrical groove is formed in the center of the circular groove, and an annular groove is formed on the edge of the circular groove, which together constitute the reflecting groove, and the remaining part forms the annular periodic ferroelectric domain film; the filter output electrode and the filter input electrode are formed on the annular periodic ferroelectric domain film respectively, the filter output electrode is located on the inner side, and a plurality of sheet-shaped filter input electrodes in central symmetry are formed between the filter output electrode and the annular groove of the reflecting groove; the surface of the above structure is packaged by the packaging shell; the radio frequency signal is input from the filter input electrode, the surface acoustic wave standing wave is generated on the surface of the periodic ferroelectric domain film, the radio frequency signal is filtered, the filter output electrode is connected to the external circuit, and the filtered radio frequency signal is sent.

8. The surface acoustic wave filter of claim 7, wherein, The width of each polarization electrode is the same, and is an integer multiple of the wavelength of the surface acoustic wave corresponding to the working frequency of the filter; the width of each insulating layer is the same, and is an integer multiple of the width of the polarization electrode.

9. The surface acoustic wave filter of claim 7, wherein, The thickness of the ferroelectric semiconductor film for forming the ferroelectric domain is 100-300 nm.

10. The surface acoustic wave filter of claim 7, wherein, The depth of the circular groove is 30-80 nm; and the depth of the reflecting groove is 300-500 nm.

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