A surface acoustic wave resonator and its formation method, and a surface acoustic wave filter.

Abstract

A surface acoustic wave (SAW) resonator and its formation method, as well as a SAW filtering device, are disclosed. The method includes: providing a substrate; forming an interdigitated electrode structure on the substrate; and forming a temperature compensation structure on the substrate. The top surface of the temperature compensation structure is a flat surface. Forming the temperature compensation structure includes forming a temperature compensation layer and a dielectric layer. The dielectric layer is formed using spin-coating glass technology. The temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. Alternatively, the dielectric layer is located on the substrate and covers the interdigitated electrode structure, and the temperature compensation layer is located on the dielectric layer. The resulting SAW resonator has an optimized process and improved performance.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a surface acoustic wave (SAW) resonator and its formation method, as well as a SAW filter. Background Technology

[0002] Radio frequency (RF) front-end chips in wireless communication devices include power amplifiers, antenna switches, RF filters, multiplexers, and low-noise amplifiers. Among these, RF filters include surface acoustic wave (SAW) filters, bulk acoustic wave (BAW) filters, micro-electro-mechanical system (MEMS) filters, and integrated passive device (IPD) filters.

[0003] Because the operating frequency of conventional piezoelectric surface acoustic wave (SAW) filters is very sensitive to temperature and has the characteristic of frequency drift with operating temperature, and because the frequency bands of RF terminals in the 5G era are becoming increasingly crowded, ordinary SAW filters are difficult to meet the requirements.

[0004] Therefore, improving the temperature stability of surface acoustic wave devices, reducing the impact of temperature on operating frequency, and developing temperature-stable filters have become necessary development goals. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a surface acoustic wave (SAW) resonator and its formation method, as well as a SAW filter, to improve the temperature stability of SAW devices and reduce the influence of temperature on the operating frequency.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for forming a surface acoustic wave resonator, comprising: providing a substrate; forming an interdigitated electrode structure on the substrate; forming a temperature compensation structure on the substrate, wherein the top surface of the temperature compensation structure is a flat surface, and forming the temperature compensation structure includes forming a temperature compensation layer and a dielectric layer, wherein the dielectric layer is formed by spin-coating glass technology, the temperature compensation layer is located on the substrate and covers the interdigitated electrode structure, and the dielectric layer is located on the temperature compensation layer; or, the dielectric layer is located on the substrate and covers the interdigitated electrode structure, and the temperature compensation layer is located on the dielectric layer.

[0007] Optionally, when the temperature compensation layer is located on the substrate and covers the interdigitated electrode structure, and the dielectric layer is located on the temperature compensation layer, the method for forming the temperature compensation layer and the dielectric layer includes: forming the temperature compensation layer on the substrate, the temperature compensation layer being located on the surface of the substrate and the sidewall surface and top surface of the interdigitated electrode structure, the top surface of the temperature compensation layer having a protrusion corresponding to the interdigitated electrode structure; forming a dielectric material layer on the temperature compensation layer, the dielectric material layer uniformly covering the surface of the temperature compensation layer, the dielectric material layer being located on the surface of the temperature compensation layer and on the sidewall surface and top surface of the protrusion; and performing heat treatment on the dielectric material layer to solidify the dielectric material layer to form the dielectric layer, the top surface of the dielectric layer being a flat surface.

[0008] Optionally, when the dielectric layer is located on the substrate and covers the interdigitated electrode structure, and the temperature compensation layer is located on the dielectric layer, the method for forming the temperature compensation layer and the dielectric layer includes: forming a dielectric material layer on the substrate, the dielectric material layer uniformly covering the surface of the substrate and the sidewall surface and top surface of the interdigitated electrode structure; performing heat treatment on the dielectric material layer to solidify the dielectric material layer and form the dielectric layer, the top surface of the dielectric layer being a flat surface; and forming the temperature compensation layer on the dielectric layer.

[0009] Optionally, the dielectric material layer may be made of a liquid organic material containing a dielectric material, including silicates, methylsilanes, methyl-silsesquioxides, or hydrogen-silsesquioxides.

[0010] Optionally, the method of forming the dielectric material layer includes spin coating; the method of heat-treating the dielectric material layer includes baking and curing; wherein the baking temperature range is 100 degrees Celsius to 300 degrees Celsius, and the curing temperature range is 300 degrees Celsius to 500 degrees Celsius.

[0011] Optionally, the dielectric layer is made of a material with a positive frequency temperature coefficient.

[0012] Optionally, the thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure; the thickness of the temperature compensation layer is 1.5 to 3 times the thickness of the interdigitated electrode structure.

[0013] Optionally, the substrate material includes a piezoelectric material, which includes lithium carbonate or lithium niobate.

[0014] Accordingly, the present invention also provides a surface acoustic wave resonator, comprising: a substrate; an interdigitated electrode structure located on the substrate; and a temperature compensation structure located on the substrate, wherein the top surface of the temperature compensation structure is a flat surface, the temperature compensation structure includes a temperature compensation layer and a dielectric layer, the dielectric layer being formed by spin-coating glass technology, the temperature compensation layer being located on the substrate and covering the interdigitated electrode structure, and the dielectric layer being located on the temperature compensation layer; or, the dielectric layer being located on the substrate and covering the interdigitated electrode structure, and the temperature compensation layer being located on the dielectric layer.

[0015] Optionally, the temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. When the dielectric layer is located on the temperature compensation layer, the temperature compensation layer is located on the surface of the substrate and the sidewall surface and top surface of the interdigitated electrode structure. The top surface of the temperature compensation layer has a protrusion corresponding to the interdigitated electrode structure. The dielectric layer is located on the surface of the temperature compensation layer, on the sidewall surface and top surface of the protrusion, and the top surface of the dielectric layer is a flat surface.

[0016] Optionally, the dielectric layer is located on the substrate and covers the interdigitated electrode structure. When the temperature compensation layer is located on the dielectric layer, the dielectric layer uniformly covers the surface of the substrate, the sidewall surface of the interdigitated electrode structure, and the top surface of the dielectric layer. The top surface of the dielectric layer is a flat surface. The top surface of the temperature compensation layer is a flat surface.

[0017] Optionally, the dielectric layer may be made of a material with a positive frequency temperature coefficient.

[0018] Optionally, the substrate material includes a piezoelectric material, which includes lithium carbonate or lithium niobate.

[0019] Optionally, the thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure; the thickness of the temperature compensation layer is 1.5 to 3 times the thickness of the interdigitated electrode structure.

[0020] Accordingly, the present invention also provides a surface acoustic wave filter device composed of a surface acoustic wave resonator.

[0021] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0022] The technical solution of this invention involves forming a temperature compensation structure on a substrate. This structure includes a temperature compensation layer and a dielectric layer. The dielectric layer is formed using spin-on glass coating (SOG). The temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. Alternatively, the dielectric layer is located on the substrate and covers the interdigitated electrode structure, with the temperature compensation layer situated on top of the dielectric layer. Based on the SOG process, when the dielectric layer is located on the substrate and covers the interdigitated electrode structure, a flat surface can be obtained, resulting in a temperature compensation layer with a flat top surface. Alternatively, when the dielectric layer is located on the temperature compensation layer, it can fill in any protrusions on the top surface of the temperature compensation layer, thus achieving a flat surface for the temperature compensation structure. This avoids the increased insertion loss of the surface acoustic wave (SAW) resonator due to uneven surface conditions, improving the performance of the SAW resonator. Furthermore, it avoids depositing an excessively thick temperature compensation layer, solving the stress concentration problem and preventing breakage of the temperature compensation layer. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a surface acoustic wave resonator in one embodiment;

[0024] Figures 2 to 4 This is a schematic diagram of the formation process of a surface acoustic wave resonator in one embodiment of the present invention;

[0025] Figure 5 and Figure 6 This is a schematic diagram of the formation process of the surface acoustic wave resonator in another embodiment of the present invention. Detailed Implementation

[0026] It should be noted that the terms "surface" and "on" in this specification are used to describe the relative spatial position and are not limited to whether there is direct contact.

[0027] As described in the background section, improving the temperature stability of surface acoustic wave (SAW) devices and reducing the impact of temperature on operating frequency, and developing temperature-stable filters have become essential for future development. This will be analyzed and explained in conjunction with specific embodiments.

[0028] Figure 1 This is a schematic diagram of the structure of a surface acoustic wave resonator in one embodiment.

[0029] Please refer to Figure 1 The surface acoustic wave resonator includes: a substrate 100; an interdigitated electrode structure 101 located on the substrate 100; and a temperature compensation layer 102 located on the substrate 100, covering the interdigitated electrode structure 101.

[0030] The temperature compensation layer 102 is made of a material with a positive temperature coefficient of frequency (TCF) to suppress frequency drift caused by temperature changes, thereby improving the sound velocity of the device. The temperature compensation layer 102 is typically made of silicon oxide, and the process for forming it is usually a deposition process. However, due to the characteristics of the deposition process, when depositing a temperature compensation layer 102 of the same thickness on the substrate 100 and the interdigital electrode structure 101, the temperature compensation layer 102 located on the interdigital electrode structure 101 will typically protrude from its top surface (as shown in region A), forming a protrusion. This protrusion will introduce SH waves into the passband region, increasing insertion loss. The protrusion will also cause changes in the original resonator's temperature coefficient of frequency (TCF) and electromechanical coupling coefficient, deviating from ideal values.

[0031] To address the issue of the protruding portion, on one hand, a sufficiently thick temperature compensation layer is deposited on the substrate 100 to cover the interdigitated electrode structure 101, making the protrusion smoother. However, an excessively thick temperature compensation layer can easily cause strong stress concentration at the interface between the substrate and the temperature compensation layer, leading to breakage of the temperature compensation layer. On the other hand, planarization processes such as chemical mechanical polishing are used to remove the protrusion. This requires depositing a thicker temperature compensation material layer for the chemical mechanical polishing process, resulting in wasted production capacity for forming the temperature compensation layer.

[0032] To address the aforementioned problems, the present invention provides a surface acoustic wave (SAW) resonator and its formation method, as well as a SAW filter. This is achieved by forming a temperature compensation structure on a substrate. The temperature compensation structure includes a temperature compensation layer and a dielectric layer. The dielectric layer is formed using spin-coating glass technology. The temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. Alternatively, the dielectric layer is located on the substrate and covers the interdigitated electrode structure, with the temperature compensation layer located on the dielectric layer. Based on the spin-on glass coating (SOG) process, when the dielectric layer is located on the substrate and covers the interdigitated electrode structure, a flat surface can be obtained, thereby forming a temperature compensation layer with a flat top surface. Alternatively, when the dielectric layer is located on the temperature compensation layer, it can fill the protrusions on the top surface of the temperature compensation layer, so that the temperature compensation structure has a flat surface. This avoids the situation where the insertion loss of the surface acoustic wave resonator increases due to the uneven surface of the temperature compensation structure, thus improving the performance of the surface acoustic wave resonator. In addition, it can avoid depositing an excessively thick temperature compensation layer, solve the stress concentration problem, and prevent the temperature compensation layer from breaking.

[0033] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] Figures 2 to 4 This is a schematic diagram of the formation process of a surface acoustic wave resonator in one embodiment of the present invention.

[0035] Please refer to Figure 2 Substrate 200 is provided.

[0036] The substrate 200 is made of a piezoelectric material, which includes lithium tantalate (LT) or lithium niobate (LN).

[0037] Please continue to refer to this. Figure 2 An interdigitated electrode structure 201 is formed on the substrate 200.

[0038] The material of the interdigitated electrode structure 201 includes metals, including one or more combinations of copper, aluminum, tungsten, cobalt, nickel, molybdenum, titanium, and tantalum.

[0039] Next, a temperature compensation structure is formed on the substrate 200. The top surface of the temperature compensation structure is a flat surface. The temperature compensation structure includes a temperature compensation layer and a dielectric layer. The dielectric layer is formed using spin-on glass coating (SOG) technology. In this embodiment, the temperature compensation layer is located on the substrate 200 and covers the interdigitated electrode structure 201, and the dielectric layer is located on the temperature compensation layer. The formation process of the temperature compensation structure is described in [reference needed]. Figure 3 and Figure 4 .

[0040] Please refer to Figure 3 A temperature compensation layer 202 is formed on the substrate 200. The temperature compensation layer 202 is located on the surface of the substrate 200 and the sidewall surface and top surface of the interdigital electrode structure 201. The top surface of the temperature compensation layer 202 has a protrusion corresponding to the interdigital electrode structure 201.

[0041] The temperature compensation layer 202 is made of a positive temperature coefficient of frequency (TCF) material, which is a material with a temperature coefficient greater than 0, and is a piezoelectric substrate capable of compensating for negative temperature coefficients.

[0042] The temperature compensation layer 202 is made of silicon oxide, silicon fluoride, or silicon carbide.

[0043] In this embodiment, the temperature compensation layer 202 is made of silicon oxide.

[0044] In this embodiment, the process for forming the temperature compensation layer 202 includes chemical vapor deposition or physical vapor deposition.

[0045] The thickness of the temperature compensation layer 202 is greater than the thickness of the interdigitated electrode structure 201. This ensures that the temperature compensation layer 202 provides sufficient temperature compensation for the piezoelectric substrate.

[0046] In this embodiment, the thickness of the temperature compensation layer 202 is 1.5 to 3 times the thickness of the interdigitated electrode structure 201.

[0047] Please refer to Figure 4 A dielectric material layer (not shown) is spin-coated onto the temperature compensation layer 202. The dielectric material layer uniformly covers the surface of the temperature compensation layer 202, including the top surface of the temperature compensation layer 202, as well as the sidewall and top surfaces of the protrusion. The dielectric material layer is then heat-treated to solidify and form a dielectric layer 203. The top surface of the dielectric layer 203 is a flat surface.

[0048] The dielectric material layer comprises: liquid organic materials containing dielectric materials, including: silicates, methylsilanes, methyl-silsesquioxides, or hydrogen-silsesquioxides.

[0049] The dielectric material layer is liquid, allowing it to flow uniformly across the temperature compensation layer 202. This fills in any protrusions on the top surface of the temperature compensation layer 202, resulting in a smooth surface for the temperature compensation structure. This prevents uneven surfaces from increasing the insertion loss of the surface acoustic wave (SAW) resonator, thus improving its performance. Furthermore, the temperature compensation layer 202 does not require a large thickness, avoiding excessive deposition and resolving stress concentration issues, thus preventing breakage.

[0050] In this embodiment, the method for forming the dielectric material layer includes spin coating; the method for heat-treating the dielectric material layer includes baking and curing; wherein the baking temperature range is 100 degrees Celsius to 300 degrees Celsius, and the curing temperature range is 300 degrees Celsius to 500 degrees Celsius.

[0051] In this embodiment, the dielectric layer 203 is made of a material with a positive temperature coefficient of frequency, and the dielectric layer 203 can also compensate for the piezoelectric substrate with a negative temperature coefficient.

[0052] In this embodiment, the thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure 201.

[0053] Accordingly, embodiments of the present invention also provide a surface acoustic wave resonator device; please refer to [further details]. Figure 4 ,include:

[0054] Substrate 200;

[0055] Interdigitated electrode structure 201 located on the substrate 200;

[0056] A temperature compensation structure is located on the substrate 200. The top surface of the temperature compensation structure is a flat surface. The temperature compensation structure includes a temperature compensation layer 202 and a dielectric layer 203. The dielectric layer 203 is formed by spin coating glass technology. The temperature compensation layer 202 is located on the substrate 200 and covers the interdigitated electrode structure 201. The dielectric layer 203 is located on the temperature compensation layer 202.

[0057] In this embodiment, the dielectric layer 203 is made of a material with a positive frequency temperature coefficient.

[0058] In this embodiment, the thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure 201; the thickness of the temperature compensation layer 202 is 1.5 to 3 times the thickness of the interdigitated electrode structure 201.

[0059] In this embodiment, the substrate 200 is made of a piezoelectric material, which includes lithium tantalate or lithium niobate.

[0060] Accordingly, embodiments of the present invention also provide a method for... Figure 4 The surface acoustic wave (SAW) filter device is composed of the aforementioned SAW resonator.

[0061] Figure 5 and Figure 6 This is a schematic diagram of the formation process of the surface acoustic wave resonator in another embodiment of the present invention.

[0062] Please refer to Figure 5 , Figure 5 In order to be in Figure 2 The schematic diagram is based on the structure. A dielectric material layer (not shown) is formed on the substrate 200. The dielectric material layer uniformly covers the surface of the substrate 200 and the sidewall and top surfaces of the interdigitated electrode structure 201. The dielectric material layer is heat-treated to solidify the dielectric material layer and form the dielectric layer 301. The top surface of the dielectric layer 301 is a flat surface.

[0063] The thickness of the dielectric layer 301 is greater than the thickness of the interdigitated electrode structure 201, and the top surface of the dielectric layer 301 is a flat surface.

[0064] The dielectric material layer is liquid, which allows it to flow uniformly on the substrate 200 and the interdigitated electrode structure 201, resulting in a dielectric layer 301 with a flat top surface for subsequent temperature compensation layer formation. This ensures a flat surface for the temperature compensation structure, preventing uneven surfaces that could increase insertion loss in the surface acoustic wave resonator and improving its performance.

[0065] In this embodiment, the method for forming the dielectric material layer includes spin coating; the method for heat-treating the dielectric material layer includes baking and curing; wherein the baking temperature range is 100 degrees Celsius to 300 degrees Celsius, and the curing temperature range is 300 degrees Celsius to 500 degrees Celsius.

[0066] In this embodiment, the dielectric layer 301 is made of a material with a positive temperature coefficient of frequency, and the dielectric layer 301 can also compensate for the piezoelectric substrate with a negative temperature coefficient.

[0067] In this embodiment, the thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure 201.

[0068] Please refer to Figure 6 A temperature compensation layer 302 is formed on the dielectric layer 301.

[0069] Please refer to the formation process of the temperature compensation layer 302. Figure 3 This will not be elaborated upon here.

[0070] Since the dielectric layer 301 is formed first, the temperature compensation layer 302 does not need to be thick, which can avoid depositing an excessively thick temperature compensation layer, solve the stress concentration problem, and prevent the temperature compensation layer from cracking.

[0071] In this embodiment, the dielectric layer 301 is made of a material with a positive frequency temperature coefficient.

[0072] In this embodiment, the thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure 201; the thickness of the temperature compensation layer 302 is 1.5 to 3 times the thickness of the interdigitated electrode structure 201.

[0073] Accordingly, embodiments of the present invention also provide a surface acoustic wave resonator device; please refer to [further details]. Figure 6 , Figure 6 medium structure and Figure 4 The difference in the structure is that the temperature compensation structure includes a temperature compensation layer 302 and a dielectric layer 301. In this embodiment, the dielectric layer 301 is located on the substrate 200 and covers the interdigitated electrode structure, and the temperature compensation layer 302 is located on the dielectric layer 301.

[0074] Accordingly, embodiments of the present invention also provide a method for... Figure 6 The surface acoustic wave (SAW) filter device is composed of the aforementioned SAW resonator.

[0075] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for forming a surface acoustic wave resonator, characterized in that, include: Provide substrate; An interdigitated electrode structure is formed on the substrate; A temperature compensation structure is formed on the substrate. The top surface of the temperature compensation structure is flat. Forming the temperature compensation structure includes forming a temperature compensation layer and a dielectric layer. The dielectric layer is formed using spin-coating glass technology. The temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. The top of the temperature compensation layer has a protrusion corresponding to the interdigitated electrode structure. The dielectric layer is located on the temperature compensation layer and fills the protrusion. The top surface of the dielectric layer is a flat surface. Alternatively, the dielectric layer is located on the substrate and covers the interdigitated electrode structure, and the top surface of the dielectric layer is a flat surface; the temperature compensation layer is located on the dielectric layer.

2. The method for forming a surface acoustic wave resonator as described in claim 1, characterized in that, The temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. When the dielectric layer is located on the temperature compensation layer, the method for forming the temperature compensation layer and the dielectric layer includes: forming the temperature compensation layer on the substrate, the temperature compensation layer being located on the surface of the substrate and the sidewall surface and top surface of the interdigitated electrode structure; forming a dielectric material layer on the temperature compensation layer, the dielectric material layer covering the top surface of the temperature compensation layer and covering the sidewall surface and top surface of the protrusion; and performing heat treatment on the dielectric material layer to solidify the dielectric material layer and form the dielectric layer.

3. The method for forming a surface acoustic wave resonator as described in claim 1, characterized in that, When the dielectric layer is located on the substrate and covers the interdigitated electrode structure, and the temperature compensation layer is located on the dielectric layer, the method for forming the temperature compensation layer and the dielectric layer includes: forming a dielectric material layer on the substrate, the dielectric material layer covering the top surface of the substrate, and covering the sidewall surface and top surface of the interdigitated electrode structure; performing heat treatment on the dielectric material layer to solidify the dielectric material layer and form the dielectric layer; and forming the temperature compensation layer on the dielectric layer.

4. The method for forming a surface acoustic wave resonator as described in claim 2 or 3, characterized in that, The dielectric material layer comprises: liquid organic materials containing dielectric materials, including: silicates, methylsilanes, methyl-silsesquioxides, or hydrogen-silsesquioxides.

5. The method for forming a surface acoustic wave resonator as described in claim 2 or 3, characterized in that, The method for forming the dielectric material layer includes spin coating; the method for heat-treating the dielectric material layer includes baking and curing; wherein the baking temperature range is 100 degrees Celsius to 300 degrees Celsius, and the curing temperature range is 300 degrees Celsius to 500 degrees Celsius.

6. The method for forming a surface acoustic wave resonator as described in claim 1, characterized in that, The dielectric layer is made of a material with a positive frequency temperature coefficient.

7. The method for forming the surface acoustic wave resonator according to claim 1, characterized in that, The thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure; the thickness of the temperature compensation layer is 1.5 to 3 times the thickness of the interdigitated electrode structure.

8. The method for forming a surface acoustic wave resonator as described in claim 1, characterized in that, The substrate is made of a piezoelectric material, which includes lithium tantalate or lithium niobate.

9. A surface acoustic wave resonator, characterized in that, include: Substrate; Interdigitated electrode structure located on the substrate; A temperature compensation structure located on the substrate, the top surface of the temperature compensation structure being a flat surface, the temperature compensation structure comprising a temperature compensation layer and a dielectric layer, the dielectric layer being formed using spin-coating glass technology; wherein... The temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. The top of the temperature compensation layer has a protrusion corresponding to the interdigitated electrode structure. The dielectric layer is located on the temperature compensation layer and fills the protrusion. The top surface of the dielectric layer is a flat surface. Alternatively, the dielectric layer is located on the substrate and covers the interdigitated electrode structure, and the top surface of the dielectric layer is a flat surface; the temperature compensation layer is located on the dielectric layer.

10. The surface acoustic wave resonator as described in claim 9, characterized in that, The temperature compensation layer is located on the substrate and covers the interdigitated electrode structure. When the dielectric layer is located on the temperature compensation layer, the temperature compensation layer is located on the surface of the substrate and the sidewall surface and top surface of the interdigitated electrode structure. The dielectric layer is located on the surface of the temperature compensation layer and on the sidewall surface and top surface of the protrusion.

11. The surface acoustic wave resonator as described in claim 9, characterized in that, The dielectric layer is located on the substrate and covers the interdigitated electrode structure. When the temperature compensation layer is located on the dielectric layer, the dielectric layer covers the surface of the substrate, the sidewall surface of the interdigitated electrode structure, and the top surface. The top surface of the temperature compensation layer is a flat surface.

12. The surface acoustic wave resonator as described in claim 9, characterized in that, The dielectric layer is made of a material with a positive frequency temperature coefficient.

13. The surface acoustic wave resonator as described in claim 9, characterized in that, The substrate is made of a piezoelectric material, which includes lithium tantalate or lithium niobate.

14. The surface acoustic wave resonator as described in claim 9, characterized in that, The thickness of the temperature compensation structure is 2 to 4 times the thickness of the interdigitated electrode structure; the thickness of the temperature compensation layer is 1.5 to 3 times the thickness of the interdigitated electrode structure.

15. A surface acoustic wave (SAW) filtering device, characterized in that, include: The surface acoustic wave resonator as described in any one of claims 1 to 14.

Images