Transverse excitation bulk acoustic wave resonator for improving power tolerance and application thereof

Abstract

The invention provides a transverse excitation bulk acoustic wave resonator for improving power tolerance and application thereof, the transverse excitation bulk acoustic wave resonator comprises supporting areas, resonance areas and anchors, the supporting areas are located at the two ends of the transverse excitation bulk acoustic wave resonator, the resonance areas are located between the supporting areas at the two ends, and the anchors are located at the two ends of the transverse excitation bulk acoustic wave resonator. The resonance area is connected with the supporting areas at the two ends through anchors; a cavity is further formed between the supporting areas at the two ends, and the cavity is located below the resonance area and the anchor; the resonance area comprises a composite film and at least two interdigital metal electrodes on the surface of the composite film, the composite film comprises a first heat conduction material layer and a first piezoelectric material layer which are stacked, and the interdigital metal electrodes are arranged on the surface of the first piezoelectric material layer. The transverse excitation bulk acoustic wave resonator has the characteristic of high power resistance, and still has the excellent acoustic performance of the resonator.

Description

Technical Field

[0001] The invention belongs to the technical field of piezoelectric acoustic wave devices and relates to a transversely excited bulk acoustic wave resonator with improved power tolerance and application thereof. Background Art

[0002] With the popularization and continuous development of 5G, the market demand for high-power equipment has gradually increased, and with the continuous reduction of chip size, the power density of front-end modules has reached a higher level. This also puts higher requirements on the power resistance characteristics of microwave acoustic filters, which are an important component of the RF front end. In order to ensure the best performance of acoustic filters under high-power conditions, it is necessary to improve the power resistance of acoustic filters. The resonator is the basic unit of the acoustic filter. As a high-frequency application resonator, the suspended Lamb wave resonator (XBAR) is inevitably accompanied by the problem of poor power resistance.

[0003] When XBAR is working, it will generate energy loss due to the properties of the material itself, and most of this loss is converted into heat energy. With the miniaturization of devices, continuous operation can easily cause heat accumulation and lead to excessive device temperature, resulting in reduced device insertion loss and worse roll-off coefficient, and also causing the device to deviate from the normal operating frequency band. In addition, since the interdigital electrodes cannot work for a long time at high temperatures, high temperatures will cause a sharp increase in thermal stress, increase the force load on the edges of the interdigital fingers, and in severe cases damage the interdigital fingers, causing device failure. Therefore, during the device design process, it is necessary to focus on improving the device's power resistance performance. Summary of the invention

[0004] The purpose of the present invention is to provide a transversely excited bulk acoustic wave resonator with improved power tolerance and its application. The transversely excited bulk acoustic wave resonator has the characteristic of high power tolerance. The method of the present invention to improve the power tolerance of the device is to increase the heat dissipation efficiency of the resonator. By adding an efficient heat conduction path, the heat generated during its operation is more efficiently conducted out of the resonance area, avoiding device failure caused by excessive temperature, and this method can still ensure the excellent acoustic performance of the resonator.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a transversely excited bulk acoustic wave resonator with improved power tolerance, the transversely excited bulk acoustic wave resonator comprising a support region, a resonance region and an anchor, the support region being located at two ends of the transversely excited bulk acoustic wave resonator, the resonance region being located between the support regions at the two ends, and the resonance region being connected to the support regions at the two ends through the anchor;

[0007] A cavity is also provided between the support regions at both ends, and the cavity is located below the resonance region and the anchor;

[0008] The resonance region includes a composite film and at least two interdigitated metal electrodes on the surface of the composite film, wherein the composite film includes a first thermal conductive material layer and a first piezoelectric material layer stacked in layers, wherein the interdigitated metal electrodes are arranged on the surface of the first piezoelectric material layer.

[0009] The present invention increases the heat dissipation performance of the resonance region by arranging a composite film including a first heat-conducting material layer and a first piezoelectric material layer in the resonance region. The addition of the heat-conducting material layer provides an efficient path for the heat diffusion of the resonator, so that the heat of the resonator is effectively diffused, thereby making the excited body acoustic wave resonator have excellent heat dissipation performance, and the resonator can still maintain a high sound velocity and a large electromechanical coupling coefficient at a high operating frequency, while also maintaining the relatively excellent acoustic characteristics of the resonator such as high sound velocity and large electromechanical coupling coefficient; therefore, the present invention improves from the acoustic resonator level, so that the transversely excited body acoustic wave resonator with excellent heat dissipation performance can improve the power resistance performance of the acoustic filter and enhance the working stability and durability of the device.

[0010] In the present invention, a cavity is further provided between the supporting regions at both ends, and the cavity is located below the resonance region and the anchor, so that the side surface of the transversely excited bulk acoustic wave resonator is in a "Π" shape.

[0011] Preferably, the first thermally conductive material layer includes any one of diamond, SiC or Si, or a combination of at least two of them.

[0012] The first thermally conductive material layer of the present invention is made of a material with high thermal conductivity, wherein the thermal conductivities of diamond, SiC and Si are 2000 W / (m×k), 490 W / (m×k) and 130 W / (m×k) respectively.

[0013] Preferably, the first piezoelectric material layer includes LiNbO3.

[0014] Preferably, the thickness of the composite film is H, where H is less than 0.5 μm, for example, 0.5 μm, 0.45 μm, 0.4 μm, 0.35 μm or 0.3 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably H≤0.4 μm.

[0015] Preferably, the thickness ratio of the first thermal conductive material layer and the first piezoelectric material layer is rh, and rh is 0-0.3, but does not include 0. For example, it can be 0.3, 0.25, 0.2, 0.15, 0.1 or 0.05, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable. Preferably, rh is 0.05-0.25.

[0016] After adding the high thermal conductivity material, the working frequency of the resonator is increased. As the thickness ratio (rh) increases, the stray mode is also enhanced. The preferred thickness ratio is ≤0.03.

[0017] In addition, there is a certain relationship between the thickness H and the thickness ratio rh of the composite film of the present invention. When H is less than 0.5 μm, rh is less than 0.3. More preferably, when H is less than 0.4 μm, rh is less than 0.25.

[0018] Preferably, the material of the interdigital metal electrodes includes Al.

[0019] Preferably, the thickness of the interdigital metal electrode does not exceed 0.1λ, for example, it may be 0.1λ, 0.05λ or 0.025λ, wherein λ is the wavelength of the transversely excited bulk acoustic wave resonator.

[0020] Preferably, the metallization rate of the interdigital metal electrode is 0.325-0.35, for example, it can be 0.325, 0.335, 0.345 or 0.35, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] Preferably, the width of the anchor is ≤ the width of the resonance region, and preferably is half the width of the resonance region.

[0022] The width of the anchor of the present invention is ≤ the width of the resonance region, and preferably smaller than the width of the resonance region, which can reduce the leakage of acoustic wave energy and improve the quality factor of the device.

[0023] Preferably, the anchor comprises a second thermal conductive material layer, a second piezoelectric material layer and a first metal layer which are stacked in sequence.

[0024] Preferably, the second heat conductive material layer corresponds to the first heat conductive material layer, and the second heat conductive material layer and the first heat conductive material layer have the same thickness.

[0025] Preferably, the second piezoelectric material layer corresponds to the first piezoelectric material layer, and the second piezoelectric material layer and the first piezoelectric material layer have the same thickness.

[0026] Preferably, the first metal layer corresponds to the interdigital metal electrode, and the first metal layer and the interdigital metal electrode have the same thickness.

[0027] The second thermally conductive material layer of the present invention corresponds to the first thermally conductive material layer, is on the same horizontal plane, and has the same thickness. The second thermally conductive material layer exemplarily includes any one of diamond, SiC or Si, or a combination of at least two of them.

[0028] The second piezoelectric material layer of the present invention also corresponds to the first piezoelectric material layer, and is on the same horizontal plane. The second piezoelectric material layer includes LiNbO3; the first metal layer of the present invention is an aluminum metal layer, and also corresponds to the interdigitated metal electrode, and is on the same horizontal plane and has the same thickness.

[0029] Preferably, the supporting region comprises a matching layer, a base layer, a third thermal conductive material layer, a third piezoelectric material layer and a second metal layer which are stacked in sequence.

[0030] Preferably, the third heat conductive material layer corresponds to the first heat conductive material layer, and the third heat conductive material layer and the first heat conductive material layer have the same thickness.

[0031] Preferably, the third piezoelectric material layer corresponds to the first piezoelectric material layer, and the third piezoelectric material layer and the first piezoelectric material layer have the same thickness.

[0032] Preferably, the second metal layer corresponds to the interdigital metal electrode, and the second metal layer and the interdigital metal electrode have the same thickness.

[0033] The third thermally conductive material layer of the present invention corresponds to the first thermally conductive material layer, is on the same horizontal plane, and has the same thickness. The third thermally conductive material layer exemplarily includes any one of diamond, SiC or Si, or a combination of at least two of them.

[0034] The third piezoelectric material layer of the present invention also corresponds to the first piezoelectric material layer, and is on the same horizontal plane. The third piezoelectric material layer includes LiNbO3; the second metal layer of the present invention is an aluminum metal layer, and also corresponds to the interdigitated metal electrode, and is on the same horizontal plane and has the same thickness.

[0035] Preferably, the matching layer comprises a PML, wherein the PML is a perfect matching layer required for simulation.

[0036] Preferably, the base layer comprises Si.

[0037] In a second aspect, the present invention provides an application of the transversely excited bulk acoustic wave resonator according to the first aspect, wherein the application includes use in an acoustic filter.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention increases the heat dissipation performance of the resonance region by arranging a composite film including a first heat-conducting material layer and a first piezoelectric material layer in the resonance region, provides an efficient path for the heat diffusion of the resonator, and effectively diffuses the heat of the resonator. Therefore, the present invention adds an efficient heat-conducting path to more efficiently conduct the heat generated during operation out of the resonance region, avoids device failure caused by excessive temperature, and makes the transversely excited bulk acoustic wave resonator have high power resistance characteristics and excellent acoustic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1a is a top view of the transversely excited bulk acoustic wave resonator described in Example 1 of the present invention;

[0041] Figure 1b is a side view of the transversely excited bulk acoustic wave resonator described in Example 1 of the present invention;

[0042] Figure 1c is a side view of the support area of ​​the transversely excited bulk acoustic wave resonator according to Example 1 of the present invention;

[0043] Figure 1d is a side view of the resonance region of the transversely excited bulk acoustic wave resonator according to Example 1 of the present invention;

[0044] Figure 1e is a side view of the anchor of the transversely excited bulk acoustic wave resonator according to Example 1 of the present invention;

[0045] Figure 2 It is the admittance response diagram of the transversely excited bulk acoustic wave resonator described in Example 1 of the present invention when the material of the first thermal conductive material layer is Si and the comparative example 1 at different thickness ratios (rh);

[0046] Figure 3 The first heat-conducting material layer is made of SiC at different thickness ratios (rh) in Example 1 of the present invention and the admittance response diagram of the transversely excited bulk acoustic wave resonator in Comparative Example 1;

[0047] Figure 4 The first heat-conducting material layer is made of diamond at different thickness ratios (rh) in Example 1 of the present invention and the admittance response diagram of the transversely excited bulk acoustic wave resonator in Comparative Example 1;

[0048] Figure 5 In Example 1 of the present invention, when the material of the first thermal conductive material layer is Si, the effect of different composite film thicknesses (H) and different thickness ratios (rh) on the electromechanical coupling coefficient (K 2 )Impact contour map;

[0049] Figure 6is a contour diagram of the effects of different composite film thicknesses (H) and different thickness ratios (rh) on the sound velocity (Vp) when the material of the first thermal conductive material layer is Si in Example 1 of the present invention;

[0050] Figure 7 In Example 1 of the present invention, when the material of the first thermal conductive material layer is SiC, the effect of different composite film thicknesses (H) and different thickness ratios (rh) on the electromechanical coupling coefficient (K 2 )Impact contour map;

[0051] Figure 8 is a contour diagram of the influence of different composite film thicknesses (H) and different thickness ratios (rh) on the sound velocity (Vp) when the material of the first thermal conductive material layer is SiC in Example 1 of the present invention;

[0052] Fig. 9 In Example 1 of the present invention, when the material of the first thermal conductive material layer is Diamond, the effect of different composite film thicknesses (H) and different thickness ratios (rh) on the electromechanical coupling coefficient (K 2 )Impact contour map;

[0053] Fig.10 is a contour diagram of the effects of different composite film thicknesses (H) and different thickness ratios (rh) on the sound velocity (Vp) when the material of the first thermal conductive material layer is Diamond in Example 1 of the present invention;

[0054] Fig.11 It is a peak temperature diagram of the transversely excited bulk acoustic wave resonator obtained by simulation when the material of the first heat conductive material layer in Example 1 of the present invention is Si and the transversely excited bulk acoustic wave resonator in Comparative Example 1 when working;

[0055] Fig.12 It is a peak temperature diagram of the transversely excited bulk acoustic wave resonator obtained by simulation when the material of the first thermally conductive material layer in Example 1 of the present invention is SiC and the transversely excited bulk acoustic wave resonator in Comparative Example 1 when they are working;

[0056] Fig.13 is a peak temperature diagram of the transversely excited bulk acoustic wave resonator obtained by simulation when the material of the first thermally conductive material layer in Example 1 of the present invention is Diamond and the transversely excited bulk acoustic wave resonator in Comparative Example 1 when they are working;

[0057] Fig.14 is a normalized distribution diagram of the transversely excited bulk acoustic wave resonator described in Example 1 of the present invention and Comparative Example 1 in the Y direction at the highest temperature frequency point;

[0058] Fig.15It is a peak temperature diagram of the lateral excitation bulk acoustic wave resonator obtained by simulation at different input powers when the material of the first thermal conductive material layer in Example 1 of the present invention is Si and the lateral excitation bulk acoustic wave resonator in Comparative Example 1;

[0059] Fig.16 It is a peak temperature diagram of the lateral excitation bulk acoustic wave resonator obtained by simulation at different input powers when the material of the first thermal conductive material layer in Example 1 of the present invention is SiC and the lateral excitation bulk acoustic wave resonator in Comparative Example 1;

[0060] Fig.17 is a peak temperature diagram of the transversely excited bulk acoustic wave resonator obtained by simulation at different input powers when the material of the first thermally conductive material layer in Example 1 of the present invention is Diamond and the transversely excited bulk acoustic wave resonator in Comparative Example 1;

[0061] Fig.18 is a comparison diagram of the temperature reduction effect of the transversely excited bulk acoustic wave resonator described in the embodiment of the present invention compared with the comparative example 1 when working at different input powers;

[0062] Fig.19 is an admittance diagram of the transversely excited bulk acoustic wave resonator described in Comparative Example 1 of the present invention when operating at different input powers;

[0063] Fig. 20 is an admittance diagram of Example 1 of the present invention when the material of the first thermal conductive material layer is diamond and the operating conditions are different from those of the embodiment 1 of the present invention;

[0064] Among them, 1-support area, 11-PML layer, 12-Si substrate layer, 13-third thermal conductive material layer, 14-third piezoelectric material layer, 15-second metal layer, 2-resonance area, 21-first thermal conductive material layer, 22-first piezoelectric material layer, 23-interdigitated metal electrodes, 3-anchor, 31-second thermal conductive material layer, 32-second piezoelectric material layer, 33-first metal layer. DETAILED DESCRIPTION

[0065] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0066] Example 1

[0067] This embodiment provides a transversely excited bulk acoustic wave resonator, the top view of which is as shown in FIG. Figure 1a As shown, it includes a support region 1, a resonance region 2 and an anchor 3; the side view of the transversely excited bulk acoustic wave resonator is shown in Figure 1bAs shown, it is in a "Π" shape, the support area 1 is located at both ends of the transverse excitation bulk acoustic wave resonator, the resonance area 2 and the anchor 3 are both located between the support areas 1 at both ends, the resonance area 2 is connected to the support areas 1 at both ends through the anchor 3, and a cavity is further provided below the resonance area 2 and the anchor 3, which is located between the support areas 1 at both ends;

[0068] The side view of the support area 1 is as follows Figure 1c As shown, it includes a PML layer 11, a Si substrate 12, a third thermal conductive material layer 13, a third piezoelectric material layer 14 and a second metal layer 15 which are stacked in sequence;

[0069] The side view of the resonance region 2 is as follows Figure 1d As shown, it includes a composite film and 10 pairs of interdigital metal electrodes 23 (also including busbars) on the surface of the composite film, the composite film includes a first thermal conductive material layer 21 and a first piezoelectric material layer 22 stacked, wherein the interdigital metal electrodes 23 are arranged on the surface of the first piezoelectric material layer 22, the thickness of the composite film is H, the thickness ratio of the first thermal conductive material layer 21 to the first piezoelectric material layer 22 is rh, the material of the interdigital metal electrodes 23 is Al, the thickness of the interdigital metal electrodes 23 does not exceed 0.1λ, λ is the wavelength of the resonator, and the metallization rate is 0.35;

[0070] The side view of the anchor 3 is as follows Figure 1e As shown, the anchor 3 includes a second thermal conductive material layer 31, a second piezoelectric material layer 32 and a first metal layer 33 which are stacked in sequence, and the width of the anchor 3 is half of the width of the resonance region 2;

[0071] The first thermal conductive material layer 21, the second thermal conductive material layer 31 and the third thermal conductive material layer 13 are made of the same material, which is Si, SiC or Diamond. The first thermal conductive material layer 21, the second thermal conductive material layer 31 and the third thermal conductive material layer 13 correspond to each other, are on the same horizontal plane, and have the same thickness; the first piezoelectric material layer 22, the second piezoelectric material layer 32 and the third piezoelectric material layer 14 are made of LiNbO3, correspond to each other, are on the same horizontal plane, and have the same thickness; the first metal layer 33 and the second metal layer 15 are both metal aluminum layers, corresponding to the interdigitated metal electrodes 23, are on the same horizontal plane, and have the same thickness.

[0072] When the material of the first thermal conductive material layer 21 in the composite film of this embodiment is Si, the thickness of the composite film is H is 0.4 μm, and rh=0.1, 0.2, 0.3, 0.4 or 0.5, the admittance diagram of the transversely excited bulk acoustic wave resonator is as follows: Figure 2As shown; when the material of the first thermal conductive material layer 21 in the composite film of this embodiment is SiC, the thickness of the composite film is H is 0.4 μm, and rh = 0.1, 0.2, 0.3, 0.4 or 0.5, the admittance schematic diagram of the transversely excited bulk acoustic wave resonator is as shown Figure 3 As shown; when the material of the first thermal conductive material layer 21 in the composite film of this embodiment is Diamond, the thickness of the composite film is H is 0.4 μm, and rh = 0.1, 0.2, 0.3, 0.4 or 0.5, the admittance diagram of the transversely excited bulk acoustic wave resonator is as shown Figure 4 As shown by Figure 2-Figure 4 It can be seen that adding high thermal conductivity materials (Si, SiC or Diamond) increases the operating frequency of the resonator, but as the thickness ratio (rh) increases, the spurious mode also increases. Figure 2 , Figure 3 The resonance point splitting in the middle curve is caused by the spurious mode being too close to the main mode, which can be eliminated by optimizing the structure.

[0073] When the material of the first thermal conductive material layer 21 in the composite film of this embodiment is Si, the total thickness H of the composite film and the different thickness ratios rh have an effect on the electromechanical coupling coefficient (K 2 ) The contour map of the impact is shown in Figure 5 As shown in the figure, the contour diagram of the effect of different composite film thickness H and different thickness ratio rh on the sound velocity (Vp) is shown in the figure Figure 6 As shown by Figure 5 and Figure 6 It can be seen that when H is less than 0.5 μm and rh is less than 0.3, the resonator coupling coefficient is relatively high (greater than 25.6%). More preferably, when H is less than 0.4 μm and rh is less than 0.25, the resonator coupling coefficient remains above 28.47%.

[0074] When the material of the first thermal conductive material layer 21 in the composite film of this embodiment is SiC, the effect of different composite film total thickness H and different thickness ratio rh on the electromechanical coupling coefficient (K 2 ) The contour map of the impact is shown in Figure 7 As shown in the figure, the contour diagram of the effect of different composite film thickness H and different thickness ratio rh on the sound velocity (Vp) is shown in the figure Figure 8 As shown by Figure 7 and Figure 8 It can be seen that when H is less than 0.5 μm and rh is less than 0.3, the resonator coupling coefficient is relatively high (greater than 24.72%). More preferably, when H is less than 0.4 μm and rh is less than 0.25, the resonator coupling coefficient remains above 27.8%.

[0075] When the material of the first thermal conductive material layer 21 in the composite film of this embodiment is diamond, the total thickness H of the composite film and the different thickness ratios rh have an effect on the electromechanical coupling coefficient (K 2 ) The contour map of the impact is shown in Fig. 9 As shown in the figure, the contour diagram of the effect of different composite film thickness H and different thickness ratio rh on the sound velocity (Vp) is shown in the figure Fig.10 As shown by Fig. 9 and Fig.10 It can be seen that when H is less than 0.5 μm and rh is less than 0.3, the resonator coupling coefficient is relatively high (greater than 26.3%). More preferably, when H is less than 0.4 μm and rh is less than 0.25, the resonator coupling coefficient remains above 28.42%.

[0076] When the material of the first heat-conducting material layer 21 in the composite film of this embodiment is Si, the thickness of the composite film is H is 0.4 μm, and rh is 0.1, 0.2, 0.3, 0.4 or 0.5, the peak temperature of the transversely excited bulk acoustic wave resonator obtained by simulation during operation is as follows: Fig.11 As shown; when the material of the first thermal conductive material layer 21 in the composite film of this embodiment is SiC, the thickness of the composite film is H is 0.4 μm, and rh = 0.1, 0.2, 0.3, 0.4 or 0.5, the peak temperature of the lateral excitation bulk acoustic wave resonator obtained by simulation during operation is as follows Fig.12 As shown; when the material of the first thermal conductive material layer 21 in the composite film of this embodiment is Diamond, the thickness of the composite film is H is 0.4 μm, and rh = 0.1, 0.2, 0.3, 0.4 or 0.5, the peak temperature of the lateral excitation bulk acoustic wave resonator obtained by simulation during operation is as follows Fig.13 As shown by Figure 11-13 It can be seen that the maximum temperature of the resonator during operation is significantly reduced, because the addition of high thermal conductivity materials provides an efficient path for resonator heat diffusion.

[0077] When the material of the first thermal conductive material layer 21 in the composite film of this embodiment is SiC, Si and Diamond, when H is 0.4 μm, and rh=0.1, 0.2, 0.3, 0.4 or 0.5, the normalized distribution diagram in the Y direction at the highest temperature frequency point is shown in 14, Fig.14 It can be seen that when the substrate is LiNbO3 (rh=0), the heat generated by the resonator accumulates in the center, that is, concentrated in the resonance area 2. When the composite film is used, the heat is effectively diffused and the heat distribution is more uniform.

[0078] When the composite film of this embodiment is made of Si, H is 0.4 μm, and rh=0.1, the peak temperature diagram of the transversely excited bulk acoustic wave resonator at different input powers obtained by simulation is as follows: Fig.15As shown, when the material of the composite film of this embodiment is SiC, H is 0.4 μm, and rh=0.1, the peak temperature diagram of the lateral excitation bulk acoustic wave resonator under different input powers obtained by simulation is as follows Fig.16 As shown, when the material of the composite film of this embodiment is Diamond, H is 0.4 μm, and rh=0.1, the peak temperature diagram of the lateral excitation BAW resonator under different input powers obtained by simulation is as follows Fig.17 As shown by Figure 15-17 It can be seen that the cooling effect is most obvious when adding Diamond, and the effect of adding Si is the worst. This is related to the thermal conductivity of the material. When the input power is 34dBm, adding Diamond can reduce the resonator temperature to 73.5℃, which is acceptable. For adding SiC and Si, the acceptable powers are around 32dBm and 30dBm respectively. Therefore, when using Diamond, the resonator can withstand a power of 34dBm, and it can withstand a power range of ≤34dBm.

[0079] When the material of the first thermal conductive material layer 21 in the composite film of this embodiment is SiC, Si and Diamond, when H is 0.4 μm, and when rh=0.1, compared with Comparative Example 1 (when the composite film is only LiNbO3), the temperature reduction effect comparison diagram when working at different input powers is as follows: Fig.18 As shown by Fig.18 It can be seen that compared with adding Si and SiC, the effect of adding Diamond to the composite membrane is the most obvious. When the input power is 36dBm, its maximum cooling efficiency reaches 75.18%. The cooling efficiency of the SiC composite membrane reaches a maximum of 64.48%. The effect of Si is relatively poor, with a maximum efficiency of 54.5%. Therefore, even if the present invention adds less thermal conductive material and even if the rh is smaller, the improvement in power resistance effect is still significant, while maintaining good acoustic properties.

[0080] When the material of the first thermal conductive material layer 21 in the composite film of this embodiment is diamond, when H is 0.4 μm, and when rh=0.1, the admittance diagrams at different input powers are as follows: Fig. 20 As shown by Fig. 20 It can be seen that due to the negative temperature coefficient characteristic of LiNbO3, when the input power increases, its admittance curve will shift to the left, causing it to deviate from the normal operating frequency band. Therefore, the present invention can reduce the impact of the increase in input power on the resonator performance; Fig.19 and Fig. 20It can be seen from the comparison that when the input power increases, the influence of the input power on the admittance of the resonator of this embodiment is significantly reduced. Similarly, adding Si and SiC can also achieve the effect of reducing the influence of the input power on the admittance of the resonator of this embodiment, but compared with Diamond, its effect is relatively reduced ( Fig.18 can be proved in ).

[0081] Comparative Example 1

[0082] This comparative example provides a transversely excited bulk acoustic wave resonator, which is the same as Example 1 except that it does not include the first heat conductive material layer, the second heat conductive material layer and the third heat conductive material layer;

[0083] The schematic diagram of the admittance of the transversely excited bulk acoustic wave resonator described in this comparative example is as follows Figure 2-Figure 4 As shown, Figure 2-Figure 4 In the case of rh = 0; the peak temperature of the transversely excited bulk acoustic wave resonator described in this comparative example is as follows Figure 11-13 As shown, Figure 11-13 In the case of rh = 0; the normalized distribution diagram of the lateral excitation bulk acoustic wave resonator in the Y direction at the highest temperature frequency point of this comparative example is as follows Fig.14 As shown, Fig.14 The case where rh=0.

[0084] The peak temperature diagram of the transversely excited BAW resonator at different input powers obtained by this comparative simulation is shown in the figure below: Figure 15-17 As shown, Figure 15-17 The example in the figure shows the case of LN; the admittance diagram of the transversely excited bulk acoustic wave resonator described in this comparative example when working at different input powers is as follows Fig.19 shown.

[0085] In summary, the present invention provides a transversely excited bulk acoustic wave resonator with improved power tolerance and its application. The transversely excited bulk acoustic wave resonator has the characteristic of high power tolerance. The present invention improves the power tolerance of the device by increasing the heat dissipation efficiency of the resonator. By adding an efficient heat conduction path, the heat generated during operation is more efficiently conducted out of the resonance area, thereby avoiding device failure caused by excessive temperature. Moreover, this method can still ensure the excellent acoustic performance of the resonator.

[0086] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A transversely excited bulk acoustic wave resonator with improved power tolerance, characterized in that: The transversely excited BAW resonator comprises a supporting region, a resonant region and an anchor, wherein the supporting region is located at two ends of the transversely excited BAW resonator, the resonant region is located between the supporting regions at the two ends, and the resonant region is connected to the supporting regions at the two ends through the anchor; A cavity is also provided between the support regions at both ends, and the cavity is located below the resonance region and the anchor; The resonance region includes a composite film and at least two interdigitated metal electrodes on the surface of the composite film, wherein the composite film includes a first thermal conductive material layer and a first piezoelectric material layer stacked in layers, wherein the interdigitated metal electrodes are arranged on the surface of the first piezoelectric material layer.

2. The transversely excited bulk acoustic wave resonator according to claim 1, characterized in that: The first thermally conductive material layer comprises any one of diamond, SiC or Si or a combination of at least two thereof; Preferably, the first piezoelectric material layer includes LiNbO3.

3. The transversely excited bulk acoustic wave resonator according to claim 1 or 2, characterized in that: The thickness of the composite film is H, wherein H is less than 0.5 μm, preferably H is less than 0.4 μm; Preferably, a thickness ratio of the first thermal conductive material layer to the first piezoelectric material layer is rh, and rh is 0-0.3, but does not include 0; Preferably, the rh is 0.05-0.

25.

4. The transversely excited bulk acoustic wave resonator according to any one of claims 1 to 3, characterized in that: The material of the interdigital metal electrode includes Al; Preferably, the thickness of the interdigitated metal electrode does not exceed 0.1λ, wherein λ is the wavelength of the transversely excited bulk acoustic wave resonator; Preferably, the metallization rate of the interdigitated metal electrode is 0.325-0.

35.

5. The transversely excited bulk acoustic wave resonator according to any one of claims 1 to 4, characterized in that: The width of the anchor is ≤ the width of the resonance region, preferably half the width of the resonance region; Preferably, the anchor comprises a second thermal conductive material layer, a second piezoelectric material layer and a first metal layer which are stacked in sequence.

6. The transversely excited bulk acoustic wave resonator according to claim 5, characterized in that: The second heat-conducting material layer corresponds to the first heat-conducting material layer, and the second heat-conducting material layer has the same thickness as the first heat-conducting material layer; Preferably, the second piezoelectric material layer corresponds to the first piezoelectric material layer, and the second piezoelectric material layer has the same thickness as the first piezoelectric material layer; Preferably, the first metal layer corresponds to the interdigital metal electrode, and the first metal layer and the interdigital metal electrode have the same thickness.

7. The transversely excited bulk acoustic wave resonator according to any one of claims 1 to 6, characterized in that: The support region includes a matching layer, a base layer, a third heat conductive material layer, a third piezoelectric material layer and a second metal layer which are stacked in sequence.

8. The transversely excited bulk acoustic wave resonator according to claim 7, characterized in that: The third heat-conducting material layer corresponds to the first heat-conducting material layer, and the third heat-conducting material layer has the same thickness as the first heat-conducting material layer; Preferably, the third piezoelectric material layer corresponds to the first piezoelectric material layer, and the thickness of the third piezoelectric material layer is the same as that of the first piezoelectric material layer; Preferably, the second metal layer corresponds to the interdigital metal electrode, and the second metal layer and the interdigital metal electrode have the same thickness.

9. The transversely excited bulk acoustic wave resonator according to claim 7 or 8, characterized in that: The matching layer includes a PML; Preferably, the base layer comprises Si.

10. Use of the transversely excited bulk acoustic wave resonator according to any one of claims 1 to 9, characterized in that: The applications include use in acoustic filters.

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