A surface acoustic wave resonator and a manufacturing method thereof

Abstract

The present invention provides a surface acoustic wave resonator and a manufacturing method thereof. The surface acoustic wave resonator includes: a piezoelectric layer; a first metal film layer located on one side of the piezoelectric layer, wherein the first metal film layer includes an interdigital transducer and a signal transmitter, and the signal transmitter is connected to the interdigital transducer; a first temperature compensation film layer located on the side of the interdigital transducer away from the piezoelectric layer, the first temperature compensation film layer covering the interdigital transducer and not covering the signal transmitter; a barrier layer located on the side of the first temperature compensation film layer away from the piezoelectric layer, the barrier layer covering the first temperature compensation film layer and not covering the signal transmitter. The surface acoustic wave resonator and the manufacturing method thereof provided by the embodiments of the present invention can achieve a zero temperature coefficient of the surface acoustic wave filter, so that the surface acoustic wave filter can operate stably in the full temperature range.

Description

Technical Field

[0001] The present invention relates to the field of communications, and particularly to a surface acoustic wave resonator and a manufacturing method thereof. Background Art

[0002] With the rapid development of mobile communication technologies, it has evolved from the initial 2G to 3G, and then to the current 4G and 5G. Handheld terminal devices have more and more functions and more and more frequency bands. For example, different functional combinations such as Global System for Mobile Communications (GSM), Time Division - Synchronous Code Division Multiple Access (TD - SCDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE) and Global Positioning System (GPS), Bluetooth, WiFi, etc. are integrated into one product. This poses challenges to product design and mass production. The frequency resources are becoming more and more crowded, and the protection intervals between the frequency bands of different communication systems are getting smaller and smaller, which puts more stringent requirements on the spectrum and power of the transmitting end of each system, ensuring that the transmitted signal has high linearity and cannot arbitrarily increase the transmitting power to increase the communication distance or reliability. At the same time, the environment at the receiving end is more severe. Especially for smaller and smaller mobile products, the interference increases, and the receiving sensitivity and anti - interference ability must be enhanced.

[0003] As a main device for radio frequency signal filtering, the surface acoustic wave filter must propose high - precision spectrum control technologies to meet the new requirements of system development, such as temperature stability. Designing a surface acoustic wave filter that can work properly in a wide temperature range has become the key to the current development of surface acoustic wave filter technology. Summary of the Invention

[0004] The surface acoustic wave resonator and the manufacturing method thereof provided by the embodiments of the present invention can achieve a zero temperature coefficient of the surface acoustic wave filter, so that the surface acoustic wave filter can work stably in the full - temperature range.

[0005] In a first aspect, an embodiment of the present invention provides a surface acoustic wave resonator, which includes:

[0006] A piezoelectric layer;

[0007] A first metal film layer, which is located on one side of the piezoelectric layer. Among them, the first metal film layer includes an interdigital transducer and a signal transmitter, and the signal transmitter is connected to the interdigital transducer;

[0008] A first temperature compensation film layer, which is located on the side of the interdigital transducer away from the piezoelectric layer. The first temperature compensation film layer covers the interdigital transducer, and the first temperature compensation film layer does not cover the signal transmitter;

[0009] A barrier layer, which is located on the side of the first temperature compensation film layer away from the piezoelectric layer. The barrier layer covers the first temperature compensation film layer, and the barrier layer does not cover the signal transmitter;

[0010] A second temperature compensation film layer, which is located on the side of the barrier layer away from the piezoelectric layer, covers the barrier layer, and does not cover the signal transmitter;

[0011] A second metal film layer, which is located on the side of the signal transmitter away from the piezoelectric layer and covers the signal transmitter.

[0012] Optionally, the surface acoustic wave resonator provided by the embodiment of the present invention further includes:

[0013] A first dielectric layer, which is located on the side of the interdigital transducer away from the piezoelectric layer, covers the interdigital transducer, and does not cover the signal transmitter;

[0014] A second dielectric layer, which is located between the first dielectric layer and the first temperature compensation film layer, covers the first dielectric layer, and does not cover the signal transmitter;

[0015] A third dielectric layer, which is located on the side of the second temperature compensation film layer away from the piezoelectric layer, covers the second temperature compensation film layer, and does not cover the second metal film layer.

[0016] Optionally, the material of the first temperature compensation film layer includes silicon oxyfluoride;

[0017] The maximum thickness of the first temperature compensation film layer is 0.5 - 1 μm.

[0018] Optionally, the material of the first dielectric layer includes silicon dioxide, and the thickness of the first dielectric layer is 10 - 50 nm;

[0019] The material of the second dielectric layer includes silicon dioxide, germanium dioxide or aluminum oxide, and the thickness of the second dielectric layer is 10 - 50 nm.

[0020] Optionally, the thickness of the piezoelectric layer is 0.1 - 0.15 mm.

[0021] Optionally, the material of the barrier layer includes aluminum oxide;

[0022] The thickness of the barrier layer is 10 - 50 nm.

[0023] In a second aspect, the embodiment of the present invention further provides a method for manufacturing a surface acoustic wave resonator, and the manufacturing method includes:

[0024] Provide a piezoelectric layer;

[0025] Form a first metal film layer on one side of the piezoelectric layer. Among them, the first metal film layer includes an interdigital transducer and a signal transmitter, and the signal transmitter is connected to the interdigital transducer;

[0026] Form a first temperature compensation film layer, a barrier layer, and a second temperature compensation film layer in sequence on the side of the first metal film layer away from the piezoelectric layer; among them, the first temperature compensation film layer covers the interdigital transducer, the barrier layer covers the temperature compensation layer, the second temperature compensation film layer covers the barrier layer, and the first temperature compensation film layer, the barrier layer, and the second temperature compensation film layer do not cover the signal transmitter;

[0027] Form a second metal film layer on the side of the signal transmitter away from the piezoelectric layer, and the second metal film layer covers the signal transmitter.

[0028] Optionally, forming a first temperature compensation film layer, a barrier layer, and a second temperature compensation film layer in sequence on the side of the first metal film layer away from the piezoelectric layer includes:

[0029] Form a first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer;

[0030] Form a barrier transition layer on the side of the first temperature compensation transition film layer away from the piezoelectric layer;

[0031] Form a second temperature compensation transition film layer on the side of the barrier transition layer away from the piezoelectric layer;

[0032] Etch the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed. Among them, the etched second temperature compensation transition film layer is the second temperature compensation film layer, the etched barrier transition layer is the barrier layer, and the etched first temperature compensation transition film layer is the first temperature compensation film layer.

[0033] Optionally, forming a first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer specifically includes:

[0034] Input a mixed gas into the vacuum chamber to form a temperature compensation material film layer. Among them, the mixed gas includes Ar, SiH 4 , Sif 4 and N 2 O;

[0035] Mechanochemically polish the temperature compensation material film layer so that the surface of the temperature compensation material film layer away from the piezoelectric layer after mechanochemical polishing is flush, forming a first temperature compensation transition film layer.

[0036] Optionally, before forming the first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer, it further includes:

[0037] Form a first dielectric transition layer on the side of the first metal film layer away from the piezoelectric layer;

[0038] Form a second dielectric transition layer on the side of the first dielectric transition layer away from the piezoelectric layer;

[0039] Forming the first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer includes:

[0040] Form a first temperature compensation transition film layer on the side of the second dielectric transition layer away from the piezoelectric layer;

[0041] Etching the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed specifically includes:

[0042] Etch the first dielectric transition layer, the second dielectric transition layer, the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed. Among them, the etched first dielectric transition layer is the first dielectric layer, and the etched second dielectric transition layer is the second dielectric layer;

[0043] After forming the second metal film layer on the side of the signal transmitter away from the piezoelectric layer, it further includes:

[0044] Form a third dielectric transition layer on the side of the second temperature compensation film layer away from the piezoelectric layer; etch the third dielectric transition layer until the surface of the second metal film layer away from the signal transmitter is completely exposed. Among them, the etched third dielectric transition layer is the third dielectric layer.

[0045] An embodiment of the present invention provides a surface acoustic wave resonator. By providing a first temperature compensation film layer on the side of the first metal film layer away from the piezoelectric layer, the temperature tolerance of the surface acoustic wave resonator can be improved, enabling the surface acoustic wave resonator to operate at a wider range of temperatures. By covering a barrier layer on the side of the first temperature compensation film layer away from the piezoelectric layer, the barrier layer can prevent the migration of some elements in the first temperature compensation film layer, thereby improving the stability of the first temperature compensation film layer. By providing a second temperature compensation film layer on the side of the barrier layer away from the first temperature compensation film layer, the temperature coefficient of the surface acoustic wave resonator can be further reduced, ultimately achieving a zero temperature coefficient. A signal transmitter is connected to the interdigital transducer, and a second metal film layer is provided to cover the signal transmitter so that after the signal transmitter receives the information detected by the interdigital transducer, it is transmitted to other devices through the second metal film layer. Since the filter is composed of resonators, the surface acoustic wave resonator provided by the embodiment of the present invention can achieve a zero temperature coefficient of the surface acoustic wave filter, thereby enabling the surface acoustic wave filter to operate stably in the full temperature range. Description of the Drawings

[0046] Figure 1 It is a schematic structural diagram of a surface acoustic wave resonator provided by an embodiment of the present invention;

[0047] Figure 2 It is a measured result diagram of the surface acoustic wave resonator provided by an embodiment of the present invention;

[0048] Figure 3 It is a relationship diagram of the relative bandwidth between the surface acoustic wave resonator provided by an embodiment of the present invention and the measured resonator at different duty cycles;

[0049] Figure 4 It is a measured value diagram of the temperature coefficient of the surface acoustic wave resonator provided by an embodiment of the present invention at different duty cycles;

[0050] Figure 5 It is a schematic flowchart of a manufacturing method of a surface acoustic wave resonator provided by an embodiment of the present invention;

[0051] Figure 6 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0052] Figure 7 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0053] Figure 8 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0054] Figure 9 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0055] Figure 10 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0056] Figure 11 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0057] Figure 12 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0058] Figure 13 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0059] Figure 14 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0060] Figure 15 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0061] Figure 16 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0062] Figure 17 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0063] Figure 18 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0064] Figure 19 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention;

[0065] Figure 20 It is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Detailed implementation manners

[0066] The following further describes in detail the embodiments of the present invention in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention, rather than limiting the embodiments of the present invention. Additionally, it should be noted that for the sake of description, only parts related to the embodiments of the present invention are shown in the accompanying drawings rather than all structures.

[0067] Figure 1 It is a schematic structural diagram of a surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 1, the surface acoustic wave resonator includes a piezoelectric layer 110; a first metal film layer 120, the first metal film layer 120 is located on one side of the piezoelectric layer 110, wherein the first metal film layer 120 includes an interdigital transducer 121 and a signal transmitter 122, and the signal transmitter 122 is connected to the interdigital transducer 121; a first temperature compensation film layer 130, the first temperature compensation film layer 130 is located on the side of the interdigital transducer 121 away from the piezoelectric layer 110, the first temperature compensation film layer 130 covers the interdigital transducer 121, and the first temperature compensation film layer 130 does not cover the signal transmitter 122; a barrier layer 140, the barrier layer 140 is located on the side of the first temperature compensation film layer 130 away from the piezoelectric layer 110, the barrier layer 140 covers the first temperature compensation film layer 130, and the barrier layer 140 does not cover the signal transmitter 122; a second temperature compensation film layer 150, the second temperature compensation film layer 150 is located on the side of the barrier layer 140 away from the piezoelectric layer 110, the second temperature compensation film layer 150 covers the barrier layer 140, and the second temperature compensation film layer 150 does not cover the signal transmitter 122; a second metal film layer 160, the second metal film layer 160 is located on the side of the signal transmitter 122 away from the piezoelectric layer 110, and the second metal film layer 160 covers the signal transmitter 122.

[0068] Specifically, the material of the piezoelectric layer 110 can be lithium tantalate, lithium niobate or quartz, etc. The material of the first metal film layer 120 includes titanium, chromium, copper, silver, aluminum, platinum or a combination thereof. The material of the second metal film layer 160 also includes titanium, chromium, copper, silver, aluminum, platinum or a combination thereof. The first temperature compensation film layer 130 includes a material with a positive temperature coefficient. The material of the first temperature compensation film layer 130 can be silicon oxynitride. The barrier layer 140 is used to prevent the migration of some elements in the first temperature compensation film layer 130. Exemplarily, when the material of the first temperature compensation film layer 130 is silicon oxynitride, the barrier layer 140 can block the migration of fluorine elements, so as to ensure that the first temperature compensation film layer 130 can work properly. The material of the second temperature compensation film layer 150 includes silicon dioxide or germanium dioxide. The second temperature compensation film layer 150 can not only play a role in temperature compensation, but also be used to adjust the bandwidth of the surface acoustic wave resonator. Since the surface acoustic wave filter includes a surface acoustic wave resonator, the purpose of improving the consistency of the surface acoustic wave filter and reducing the temperature coefficient is also achieved. Figure 2 is the measured result graph of the surface acoustic wave resonator provided by the embodiment of the present invention. Refer to Figure 2 , Figure 2 in which the ordinate represents the admittance amplitude, Figure 2 in which the abscissa represents the frequency. It can be obtained from Figure 2 that the relative bandwidth of the surface acoustic wave resonator provided by this embodiment reaches 4.2%, and it can be seen from Figure 2 that the curve in the passband of the surface acoustic wave resonator provided by this embodiment is smooth and there are no any clutter modes.Figure 3 It is a relationship diagram of the relative bandwidth between the surface acoustic wave resonator provided by the embodiment of the present invention and the measured resonator at different duty cycles. Refer to Figure 3 , when the duty cycle is above 0.5, the relative bandwidth of the surface acoustic wave resonator provided by this embodiment is greater than 4%, which is larger than the bandwidth of the conventional surface acoustic wave resonator, achieving a larger bandwidth. The signal transmitter 122 is respectively connected to the interdigital transducer 121 and the second metal film layer 160, and is used to transmit the information detected by the interdigital transducer 121 to the second metal film layer 160, and the second metal film layer 160 then transmits the information to other devices. Figure 4 It is a measured value diagram of the temperature coefficient of the surface acoustic wave resonator provided by the embodiment of the present invention at different duty cycles. Refer to Figure 4 , when the duty cycle of the surface acoustic wave resonator is in the range of 0.4 to 0.55, the temperature coefficient of the surface acoustic wave resonator provided by this embodiment is in the range of -6 to +8 ppm / K. Compared with the temperature coefficient of the traditional temperature-compensated surface acoustic wave filter in the range of -15 ppm / K to -25 ppm / K, the temperature coefficient of the surface acoustic wave resonator provided by this embodiment can reach 0, thereby ensuring that the temperature coefficient of the surface acoustic wave filter including the surface acoustic wave resonator provided by the embodiment of the present invention reaches 0. The surface acoustic wave resonator provided by this embodiment can work normally in a larger temperature range, thereby reducing the dependence of the surface acoustic wave filter on temperature.

[0069] The embodiment of the present invention provides a surface acoustic wave resonator. By setting a first temperature compensation film layer on the side of the first metal film layer away from the piezoelectric layer, the temperature tolerance of the surface acoustic wave resonator can be improved, so that the surface acoustic wave resonator can work at a wider range of temperatures. By covering a barrier layer on the side of the first temperature compensation film layer away from the piezoelectric layer, the barrier layer can block the migration of some elements in the first temperature compensation film layer, thereby improving the stability of the first temperature compensation film layer. By setting a second temperature compensation film layer on the side of the barrier layer away from the first temperature compensation film layer, the temperature coefficient of the surface acoustic wave resonator can be further reduced, and finally a zero temperature coefficient is achieved. A signal transmitter is connected to the interdigital transducer, and a second metal film layer is provided to cover the signal transmitter so that after the signal transmitter receives the information detected by the interdigital transducer, it is transmitted to other devices through the second metal film layer. Since the filter is composed of resonators, the surface acoustic wave resonator provided by the embodiment of the present invention can achieve a zero temperature coefficient of the surface acoustic wave filter, so that the surface acoustic wave filter can work stably in the full temperature range.

[0070] Optionally, continue to refer to Figure 1, the surface acoustic wave resonator further includes a first dielectric layer 170, the first dielectric layer 170 is located on the side of the interdigital transducer 121 away from the piezoelectric layer 110, the first dielectric layer 170 covers the interdigital transducer 121, and the first dielectric layer 170 does not cover the signal transmitter 122; a second dielectric layer 180, the second dielectric layer 180 is located between the first dielectric layer 170 and the first temperature compensation film layer 130, the second dielectric layer 180 covers the first dielectric layer 170, and the second dielectric layer 180 does not cover the signal transmitter 122; a third dielectric layer 190, the third dielectric layer 190 is located on the side of the second temperature compensation film layer 150 away from the piezoelectric layer 110, the third dielectric layer 190 covers the second temperature compensation film layer 150, and the third dielectric layer 190 does not cover the second metal film layer 160.

[0071] Specifically, the setting of the first dielectric layer 170 and the second dielectric layer 180 improves the power tolerance of the surface acoustic wave resonator provided in this embodiment, and also improves the power tolerance of the filter including the surface acoustic wave resonator provided in the embodiment of the present invention, preventing the surface acoustic wave filter from being burned out due to high power, thereby further extending the service life of the surface acoustic wave filter. In addition, the first dielectric layer 170 and the second dielectric layer 180 are also used to prevent the migration of some elements in the first temperature compensation film layer 130. Exemplarily, when the material of the first temperature compensation film layer 130 is silicon oxyfluoride, the first dielectric layer 170 and the second dielectric layer 180 can block the migration of fluorine elements, so as to ensure that the first temperature compensation film layer 130 can work properly. The material of the third dielectric layer 190 can be silicon nitride, and the third dielectric layer 190 is used to protect the second temperature compensation film layer 150 from being affected by moisture in the air. The third dielectric layer 190 is also used to adjust the operating frequency of the surface acoustic wave resonator, thereby improving the yield of the product.

[0072] Optionally, continue to refer to Figure 1 , the material of the first temperature compensation film layer 130 includes silicon oxyfluoride; the maximum thickness h of the first temperature compensation film layer 130 includes 0.5 - 1 μm.

[0073] Specifically, the maximum thickness of the first temperature compensation film layer 130 represents the maximum distance h from the surface of the first temperature compensation film layer 130 away from the piezoelectric layer 110 to the surface adjacent to the piezoelectric layer 110. Setting the material of the first temperature compensation film layer 130 as silicon oxyfluoride and setting the maximum thickness h of the first temperature compensation film layer 130 in the range of 0.5 - 1 μm can improve the temperature tolerance of the surface acoustic wave resonator and further improve the temperature tolerance of the surface acoustic wave filter.

[0074] Optionally, the material of the first dielectric layer includes silicon dioxide, and the thickness of the first dielectric layer is 10 - 50 nm; the material of the second dielectric layer includes silicon dioxide, germanium dioxide or aluminum oxide, and the thickness of the second dielectric layer is 10 - 50 nm.

[0075] Specifically, controlling the thickness of the first dielectric layer within 10 - 50 nm, controlling the thickness of the second dielectric layer within 10 - 50 nm, setting the material of the first dielectric layer to include silicon dioxide, and setting the material of the second dielectric layer to include silicon dioxide, germanium dioxide or aluminum oxide can improve the power tolerance of the surface acoustic wave resonator provided in this embodiment, and also improve the power tolerance of the filter including the surface acoustic wave resonator provided in the embodiment of the present invention, preventing the surface acoustic wave filter from being burned out due to a large power, thereby further extending the service life of the surface acoustic wave filter, and also enabling the first dielectric layer and the second dielectric layer to prevent the migration of some elements in the first temperature compensation film layer. Exemplarily, when the material of the first temperature compensation film layer is silicon oxynitride, the first dielectric layer and the second dielectric layer can block the migration of fluorine elements, thereby ensuring that the first temperature compensation film layer can work properly.

[0076] Optionally, the thickness of the piezoelectric layer is 0.1 - 0.15 mm.

[0077] Specifically, setting the thickness of the piezoelectric layer within the range of 0.1 - 0.15 mm can reduce the volume of the surface acoustic wave resonator, enabling the surface acoustic wave resonator to develop towards miniaturization.

[0078] Optionally, the material of the barrier layer includes aluminum oxide; the thickness of the barrier layer is 10 - 50 nm.

[0079] Specifically, aluminum oxide is a stable oxide with good airtightness, which can prevent the migration of some elements in the first temperature compensation film layer. In addition, aluminum oxide has a low cost and the material is easy to obtain, which can reduce the manufacturing cost of the surface acoustic wave resonator, and further reduce the manufacturing cost of the surface acoustic wave filter.

[0080] Figure 5 It is a schematic flow chart of a method for manufacturing a surface acoustic wave resonator provided in an embodiment of the present invention. Refer to Figure 5 , the method for manufacturing the surface acoustic wave resonator provided in this embodiment includes:

[0081] S210. Provide a piezoelectric layer.

[0082] S220. Form a first metal film layer on one side of the piezoelectric layer, wherein the first metal film layer includes an interdigital transducer and a signal transmitter, and the signal transmitter is connected to the interdigital transducer.

[0083] S230. Form a first temperature compensation film layer, a barrier layer, and a second temperature compensation film layer in sequence on the side of the first metal film layer away from the piezoelectric layer; wherein, the first temperature compensation film layer covers the interdigital transducer, the barrier layer covers the temperature compensation layer, the second temperature compensation film layer covers the barrier layer, and neither the first temperature compensation film layer, the barrier layer, nor the second temperature compensation film layer covers the signal transmitter.

[0084] S240. Form a second metal film layer on the side of the signal transmitter away from the piezoelectric layer, and the second metal film layer covers the signal transmitter.

[0085] Optionally, forming a first temperature compensation film layer, a barrier layer, and a second temperature compensation film layer in sequence on the side of the first metal film layer away from the piezoelectric layer includes: forming a first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer; forming a barrier transition layer on the side of the first temperature compensation transition film layer away from the piezoelectric layer; forming a second temperature compensation transition film layer on the side of the barrier transition layer away from the piezoelectric layer; etching the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed, wherein the etched second temperature compensation transition film layer is the second temperature compensation film layer, the etched barrier transition layer is the barrier layer, and the etched first temperature compensation transition film layer is the first temperature compensation film layer.

[0086] Optionally, forming the first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer specifically includes: inputting a mixed gas into the vacuum chamber to form a temperature compensation material film layer, wherein the mixed gas includes Ar, SiH 4 , Sif 4 , and N 2 O; performing mechanical chemical polishing on the temperature compensation material film layer to make the surface of the mechanically chemically polished temperature compensation material film layer away from the piezoelectric layer flat, thereby forming the first temperature compensation transition film layer.

[0087] Optionally, before forming the first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer, the following steps are also included: forming a first dielectric transition layer on the side of the first metal film layer away from the piezoelectric layer; forming a second dielectric transition layer on the side of the first dielectric transition layer away from the piezoelectric layer; forming the first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer includes: forming the first temperature compensation transition film layer on the side of the second dielectric transition layer away from the piezoelectric layer; etching the second temperature compensation transition film layer, the barrier transition layer and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed, specifically including: etching the first dielectric transition layer, the second dielectric transition layer, the second temperature compensation transition film layer, the barrier transition layer and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed, wherein the etched first dielectric transition layer is the first dielectric layer, and the etched second dielectric transition layer is the second dielectric layer; after forming the second metal film layer on the side of the signal transmitter away from the piezoelectric layer, the following steps are also included: forming a third dielectric transition layer on the side of the second temperature compensation film layer away from the piezoelectric layer; etching the third dielectric transition layer until the surface of the second metal film layer away from the signal transmitter is completely exposed, wherein the etched third dielectric transition layer is the third dielectric layer.

[0088] It should be noted that the manufacturing method of the surface acoustic wave resonator provided in the above embodiment is to form the surface acoustic wave resonator provided in the embodiment of the present invention by fabricating a first metal film layer, a first dielectric layer, a second dielectric layer, a first temperature compensation film layer, a barrier layer, a second temperature compensation film layer, a second metal film layer and a third dielectric layer on one side of the piezoelectric layer. In order to fabricate a surface acoustic wave resonator with better performance, the surface acoustic wave resonator can be fabricated by using a piezoelectric transition layer instead of the piezoelectric layer. In the following embodiments, taking the piezoelectric transition layer instead of the piezoelectric layer as an example will be described in detail.

[0089] Provide a piezoelectric transition layer. Figure 6 This is a schematic structural diagram of another surface acoustic wave resonator provided by the embodiment of the present invention. Refer to Figure 6 , before forming the first metal film layer on one side of the piezoelectric transition layer 111, it is necessary to coat a first photoresist layer 210 on one side of the piezoelectric transition layer 111, and the first photoresist layer 210 is used to prevent other pollutants from contaminating the surface of the piezoelectric transition layer 111. Figure 7 This is a schematic structural diagram of another surface acoustic wave resonator provided by the embodiment of the present invention. Refer to Figure 7 , fabricate a metal reflection layer 220 on the side of the piezoelectric transition layer 111 away from the first photoresist layer, and then remove the first photoresist layer. Figure 8 This is a schematic structural diagram of another surface acoustic wave resonator provided by the embodiment of the present invention. Refer to Figure 8, a second photoresist layer is coated on the side of the piezoelectric transition layer 111 away from the metal reflective layer 220, and the second photoresist layer is exposed, baked, developed and hardened to form a first photoresist pattern layer 230. The first photoresist pattern layer 230 includes a plurality of first photoresist patterns 231, and the angle θ between the side surface of each first photoresist pattern 231 and the surface of the first photoresist pattern 231 close to the piezoelectric transition layer 111 is greater than 90°. Figure 9 is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 9 , a metal material is deposited on the piezoelectric transition layer 111 and the first photoresist pattern layer, and the metal material on the surface of the first photoresist pattern layer and the first photoresist pattern layer is removed to form a first metal film layer 120. The metal reflective layer 220 has the characteristic of being light-impermeable. When the metal reflective layer 220 is disposed on one side of the piezoelectric transition layer 111 and the first photoresist pattern layer is formed on the side of the piezoelectric transition layer 111 away from the metal reflective layer 220, the lithography accuracy can be improved, and the etching effect can be prevented from being affected due to the light transmission of the piezoelectric transition layer 111. Figure 10 is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 10 , a first dielectric transition layer 171 is formed on the side of the first metal film layer 120 away from the piezoelectric transition layer 111 by plasma enhanced chemical vapor deposition. Figure 11 is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 11 , a second dielectric transition layer 181 is formed on the side of the first dielectric transition layer 171 away from the piezoelectric transition layer 111 by plasma enhanced chemical vapor deposition. Figure 12 is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 12 , a temperature compensation material film layer 131 is formed on the side of the second dielectric transition layer 181 away from the piezoelectric transition layer 111. The formation of the temperature compensation material film layer 131 specifically includes: controlling the temperature in the chamber to be 250 °C, controlling the power of the coating machine to be in the range of 130 - 280 W, controlling the pressure in the chamber to be 1.4 Torr, the Ar flow rate input into the chamber is in the range of 375 - 1000 sccm, the flow rate of SiH 4 input into the chamber is 10 sccm, the flow rate of SiF 4 input into the chamber is 40 sccm, the flow rate of N 2 O is in the range of 300 - 1000 sccm. By controlling the coating temperature, power, pressure, and Ar, SiH 4 , Sif 4 , N 2The flow rate ratio of gases such as O is adjusted to control the stress of the temperature compensation material film layer 131, preventing excessive stress in the temperature compensation material film layer 131 from deforming the piezoelectric transition layer 111. The fluorine content in the silicon oxyfluoride can also be controlled, and the fluorine content ratio should not be too high, preferably in the range of 2% to 4%. Figure 13 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 13 , and a mechanical chemical polishing method is used to planarize and thin the temperature compensation material film layer to form a first temperature compensation transition film layer 132. Figure 14 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 14 , and a barrier transition layer 141 is formed on the side of the first temperature compensation transition film layer 132 away from the piezoelectric transition layer 111. Figure 15 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 15 , and a second temperature compensation transition film layer 151 is formed on the side of the barrier transition layer 141 away from the piezoelectric transition layer 111. Figure 16 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 16 , and a third photoresist layer is formed on the side of the second temperature compensation transition film layer away from the piezoelectric transition layer 111. The third photoresist layer is masked, exposed, and developed to form a second photoresist pattern layer. The first dielectric transition layer, the second dielectric transition layer, the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer are etched until the surface of the signal transmitter away from the piezoelectric transition layer is completely exposed. Figure 16 This is a schematic structural diagram of a surface acoustic wave resonator showing the formation of the first dielectric layer 170, the second dielectric layer 180, the second temperature compensation film layer 150, the barrier layer 140, and the first temperature compensation film layer 130. Figure 17 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 17 , and a second metal film layer 160 is formed on the side of the signal transmitter 122 away from the piezoelectric transition layer 111. The second metal film layer 160 covers the signal transmitter 122, and the surface of the second metal film layer 160 away from the piezoelectric transition layer 111 can be flush with the surface of the second temperature compensation film layer 150 away from the piezoelectric transition layer 111. Figure 18 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 18 , and a third dielectric transition layer 191 is formed on the side of the second temperature compensation film layer 150 away from the piezoelectric transition layer 111. Figure 19 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 19, etch the third dielectric transition layer until the surface of the second metal film layer 160 away from the signal transmitter 122 is completely exposed, and the etched third dielectric transition layer is the third dielectric layer 190. Figure 20 This is a schematic structural diagram of another surface acoustic wave resonator provided by an embodiment of the present invention. Refer to Figure 20 , and remove the metal reflection layer. Continue to refer to Figure 1 , thin the piezoelectric transition layer to form the piezoelectric layer 110. Figure 1 It can represent the schematic structural diagram of the surface acoustic wave resonator after thinning the piezoelectric transition layer.

[0090] The manufacturing method of the surface acoustic wave resonator provided in this embodiment and the surface acoustic wave resonator provided in any embodiment of the present invention belong to the same inventive concept and have corresponding beneficial effects. The technical details not elaborated in this embodiment are elaborated in the surface acoustic wave resonator provided in any embodiment of the present invention.

[0091] Note that the above is only the preferred embodiment of the embodiment of the present invention and the applied technical principle. Those skilled in the art will understand that the embodiments of the present invention are not limited to the specific embodiments described here, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the embodiments of the present invention. Therefore, although the embodiments of the present invention have been described in more detail through the above embodiments, the embodiments of the present invention are not limited to the above embodiments. Without departing from the inventive concept of the embodiments of the present invention, more other equivalent embodiments can be included, and the scope of the embodiments of the present invention is determined by the scope of the appended claims.

Claims

1. A surface acoustic wave resonator, characterized in that, it comprises: a piezoelectric layer; a first metal film layer, the first metal film layer being located on one side of the piezoelectric layer, wherein the first metal film layer comprises an interdigital transducer and a signal transmitter, and the signal transmitter is connected to the interdigital transducer; a first temperature compensation film layer, the first temperature compensation film layer being located on the side of the interdigital transducer away from the piezoelectric layer, the first temperature compensation film layer covering the interdigital transducer and not covering the signal transmitter; a barrier layer, the barrier layer being located on the side of the first temperature compensation film layer away from the piezoelectric layer, the barrier layer covering the first temperature compensation film layer and not covering the signal transmitter; the barrier layer is used to prevent the migration of some elements in the first temperature compensation film layer; a second temperature compensation film layer, the second temperature compensation film layer being located on the side of the barrier layer away from the piezoelectric layer, the second temperature compensation film layer covering the barrier layer and not covering the signal transmitter; a second metal film layer, the second metal film layer being located on the side of the signal transmitter away from the piezoelectric layer, the second metal film layer covering the signal transmitter.

2. The surface acoustic wave resonator according to claim 1, characterized in that, it further comprises: a first dielectric layer, the first dielectric layer being located on the side of the interdigital transducer away from the piezoelectric layer, the first dielectric layer covering the interdigital transducer and not covering the signal transmitter; a second dielectric layer, the second dielectric layer being located between the first dielectric layer and the first temperature compensation film layer, the second dielectric layer covering the first dielectric layer and not covering the signal transmitter; a third dielectric layer, the third dielectric layer being located on the side of the second temperature compensation film layer away from the piezoelectric layer, the third dielectric layer covering the second temperature compensation film layer and not covering the second metal film layer.

3. The surface acoustic wave resonator according to claim 1, characterized in that, the material of the first temperature compensation film layer comprises silicon oxyfluoride; the maximum thickness of the first temperature compensation film layer comprises 0.5 - 1 μm.

4. The surface acoustic wave resonator according to claim 2, characterized in that, the material of the first dielectric layer comprises silicon dioxide, and the thickness of the first dielectric layer comprises 10 - 50 nm; the material of the second dielectric layer comprises silicon dioxide, germanium dioxide or aluminum oxide, and the thickness of the second dielectric layer comprises 10 - 50 nm.

5. The surface acoustic wave resonator according to claim 1, characterized in that, the thickness of the piezoelectric layer comprises 0.1 - 0.15 mm.

6. The surface acoustic wave resonator according to claim 1, characterized in that, the material of the barrier layer comprises aluminum oxide; the thickness of the barrier layer comprises 10 - 50 nm.

7. A manufacturing method of a surface acoustic wave resonator, characterized in that, it comprises: providing a piezoelectric layer; A first metal film layer is formed on one side of the piezoelectric layer. The first metal film layer includes an interdigital transducer and a signal transmitter, and the signal transmitter is connected to the interdigital transducer; A first temperature compensation film layer, a barrier layer, and a second temperature compensation film layer are sequentially formed on the side of the first metal film layer away from the piezoelectric layer. The first temperature compensation film layer covers the interdigital transducer, the barrier layer covers the first temperature compensation film layer, the second temperature compensation film layer covers the barrier layer, and the first temperature compensation film layer, the barrier layer, and the second temperature compensation film layer do not cover the signal transmitter. The barrier layer is used to prevent the migration of some elements in the first temperature compensation film layer; A second metal film layer is formed on the side of the signal transmitter away from the piezoelectric layer, and the second metal film layer covers the signal transmitter.

8. The manufacturing method according to claim 7, characterized in that, forming a first temperature compensation film layer, a barrier layer, and a second temperature compensation film layer on the side of the first metal film layer away from the piezoelectric layer includes: forming a first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer; forming a barrier transition layer on the side of the first temperature compensation transition film layer away from the piezoelectric layer; forming a second temperature compensation transition film layer on the side of the barrier transition layer away from the piezoelectric layer; etching the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed. After etching, the second temperature compensation transition film layer is the second temperature compensation film layer, the etched barrier transition layer is the barrier layer, and the etched first temperature compensation transition film layer is the first temperature compensation film layer.

9. The manufacturing method according to claim 8, characterized in that, forming a first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer specifically includes: Input a mixed gas into the vacuum chamber to form a temperature compensation material film layer, wherein the mixed gas includes Ar, SiH 4 , Sif 4 and N 2 O; performing mechanochemical polishing on the temperature compensation material film layer so that the surface of the mechanochemically polished temperature compensation material film layer away from the piezoelectric layer is flat to form a first temperature compensation transition film layer.

10. The manufacturing method according to claim 8, characterized in that: before forming a first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer, it further includes: forming a first dielectric transition layer on the side of the first metal film layer away from the piezoelectric layer; forming a second dielectric transition layer on the side of the first dielectric transition layer away from the piezoelectric layer; forming a first temperature compensation transition film layer on the side of the first metal film layer away from the piezoelectric layer includes: forming a first temperature compensation transition film layer on the side of the second dielectric transition layer away from the piezoelectric layer; etching the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed specifically includes: Etch the first dielectric transition layer, the second dielectric transition layer, the second temperature compensation transition film layer, the barrier transition layer, and the first temperature compensation transition film layer until the surface of the signal transmitter away from the piezoelectric layer is completely exposed. Among them, the etched first dielectric transition layer is the first dielectric layer, and the etched second dielectric transition layer is the second dielectric layer; After forming a second metal film layer on the side of the signal transmitter away from the piezoelectric layer, it further includes: Form a third dielectric transition layer on the side of the second temperature compensation film layer away from the piezoelectric layer; Etch the third dielectric transition layer until the surface of the second metal film layer away from the signal transmitter is completely exposed. Among them, the etched third dielectric transition layer is the third dielectric layer.

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