Surface acoustic wave resonance device

Abstract

A surface acoustic wave resonance device comprises an interdigital electrode structure which is located on the surface of a piezoelectric layer, has a first thickness and comprises a plurality of first electrode strips and a plurality of second electrode strips; the first dielectric layer is positioned on the piezoelectric layer; the first load part and the second load part are located on the first dielectric layer, the first load part and the second load part are located at the two opposite ends of the overlapping area in the first direction respectively, a first distance is formed between the first load part and the interdigital electrode structure, and a second distance is formed between the second load part and the interdigital electrode structure; the ratio of the first distance to the first thickness is greater than 0.5, and the ratio of the second distance to the first thickness is greater than 0.5, so that the surface acoustic wave resonance device is excited to form a piston mode, a high-order transverse parasitic mode is effectively inhibited, and electrostatic breakdown caused by too small first distance or too small second distance is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to a technical field of semiconductor, especially relate to a surface acoustic wave resonator. BACKGROUND

[0002] The radio frequency (RF) front-end chip of the wireless communication device includes power amplifier, antenna switch, radio frequency filter, multiplexer and low noise amplifier, etc. Among them, the radio frequency filter includes piezoelectric surface acoustic wave (SAW) filter, piezoelectric bulk acoustic wave (BAW) filter, micro-electro-mechanical system (MEMS) filter, integrated passive device (IPD) filter, etc.

[0003] The quality factor value (Q value) of the surface acoustic wave resonator is higher, and the surface acoustic wave resonator is used to manufacture the radio frequency filter with low insertion loss and high out-of-band rejection, that is, the surface acoustic wave resonator is the mainstream radio frequency filter used in the wireless communication device such as mobile phone and base station.

[0004] However, the performance of the existing surface acoustic wave resonator needs to be improved. UTILITY MODEL CONTENT

[0005] The technical problem solved by the utility model is to provide a surface acoustic wave resonator to improve the performance of the surface acoustic wave resonator.

[0006] To solve the above technical problems, the utility model discloses a surface acoustic wave resonant device, comprising: piezoelectric layer;The interdigital electrode structure of piezoelectric layer surface is located, the interdigital electrode structure has first thickness, the interdigital electrode structure includes the first busbar and the second busbar who arranges in parallel along the first direction, with a plurality of first electrode strips of first busbar connection, and a plurality of second electrode strips are connected with second busbar, a plurality of first electrode strips and a plurality of second electrode strips are parallel to the first direction and along the second direction arrangement, the first direction and the second direction are perpendicular to each other, a plurality of first electrode strips and a plurality of second electrode strips staggered interval arrangement, first busbar and second busbar between there is first gap area, overlapping area and second gap area along the first direction sequentially arranged, the first electrode strip and the second electrode strip in the overlapping area along the second direction each other overlap,;First dielectric layer on the piezoelectric layer is located, the first dielectric layer covers the interdigital electrode structure;First load part and second load part on the first dielectric layer, first load part and second load part are located on the opposite two ends of the overlapping area in the first direction respectively, along the direction perpendicular to the piezoelectric layer surface, first load part and the interdigital electrode structure between there is first distance, second load part and the interdigital electrode structure between there is second distance, the ratio of first distance and first thickness is greater than 0.5, the ratio of second distance and first thickness is greater than 0.5;Second dielectric layer on the first dielectric layer, the second dielectric layer covers the first load part and the second load part.

[0007] Optionally, the first electrode strip includes a first coincident portion and a first extension portion, the first coincident portion is located in the overlapping area, the first extension portion is located in the first gap area, the first coincident portion includes a first terminal portion and a second terminal portion opposite in the first direction, and a first intermediate portion located between the first terminal portion and the second terminal portion, the first terminal portion is connected with the first extension portion, the first extension portion is connected with the first busbar, the second electrode strip includes a second coincident portion and a second extension portion, the second coincident portion is located in the overlapping area, the second extension portion is located in the second gap area, the second coincident portion includes a third terminal portion and a fourth terminal portion opposite in the first direction, and a second intermediate portion located between the third terminal portion and the fourth terminal portion, the fourth terminal portion is connected with the second extension portion, the second extension portion is connected with the second busbar, the third terminal portion and the first busbar have a first gap, the second terminal portion and the second busbar have a second gap, the first load part is located on a plurality of first terminal portions and a plurality of third terminal portions, and the second load part is located on a plurality of second terminal portions and a plurality of fourth terminal portions.

[0008] Optionally, the first load portion has the first distance with the first terminal portion, and has the first distance with the third terminal portion; the second load portion has the second distance with the second terminal portion, and has the second distance with the fourth terminal portion.

[0009] Optionally, the first load portion comprises a plurality of first load sub-portions, one of the first load sub-portions being located on one of the first electrode strips or one of the second electrode strips; the second load portion comprises a plurality of second load sub-portions, one of the second load sub-portions being located on one of the first electrode strips or one of the second electrode strips.

[0010] Optionally, the first load portion extends along the second direction, and the first load portion spans a plurality of the first electrode strips and a plurality of the second electrode strips; the second load portion extends along the second direction, and the second load portion spans a plurality of the first electrode strips and a plurality of the second electrode strips.

[0011] Optionally, the interdigital electrode structure further comprises: a plurality of first dummy electrode strips connected with the first bus, the first dummy electrode strips and the second electrode strips having third gaps therebetween, the plurality of first dummy electrode strips being parallel to the first direction, and the first dummy electrode strips being staggered and spaced apart from the first electrode strips; a plurality of second dummy electrode strips connected with the second bus, the second dummy electrode strips and the first electrode strips having fourth gaps therebetween, the plurality of second dummy electrode strips being parallel to the first direction, and the second dummy electrode strips being staggered and spaced apart from the second electrode strips.

[0012] Optionally, the first load portion further extends onto the first dummy electrode strips; and the second load portion further extends onto the second dummy electrode strips.

[0013] Optionally, the first load portion further extends onto the first gap regions; and the second load portion further extends onto the second gap regions.

[0014] Optionally, the first load portion has a first width in the first direction, and a ratio of the first width to a wavelength of a sound wave excited by the interdigital electrode structure ranges from 1:10 to 2:1; the second load portion has a second width in the first direction, and a ratio of the second width to the wavelength of the sound wave excited by the interdigital electrode structure ranges from 1:10 to 2:1.

[0015] Optionally, a thickness of the first load portion ranges from 0.2% to 10% of the wavelength of the sound wave excited by the interdigital electrode structure; and a thickness of the second load portion ranges from 0.2% to 10% of the wavelength of the sound wave excited by the interdigital electrode structure.

[0016] Optionally, the first distance is equal to the second distance.

[0017] Optionally, the second medium layer comprises a first sub-medium layer and a second sub-medium layer located on the surface of the first sub-medium layer, the first load part is located on the surface of the first medium layer, and the second load part is located on the surface of the first sub-medium layer.

[0018] Compared with the prior art, the technical scheme of the embodiment of the utility model has the following beneficial effects:

[0019] In the surface acoustic wave resonant device provided by the technical scheme of the utility model, the first load part and the second load part are respectively arranged on the two opposite ends of the overlapping area along the first direction, so that the sound wave speed of the end area of the interdigital electrode structure is less than the sound wave speed of the middle area, thereby forming a piston mode, the high-order transverse parasitic mode can be effectively inhibited, and the quality factor (Q) of the surface acoustic wave resonant device is improved; in addition, the first load part and the interdigital electrode structure have a first distance, the second load part and the interdigital electrode structure have a second distance, the first distance and the second distance are limited, and electrostatic breakdown caused by too small first distance or too small second distance is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 And Figure 2 It is a structural schematic diagram of a surface acoustic wave resonant device;

[0021] Figures 3 to 6 It is a structural schematic diagram of a surface acoustic wave resonant device of the embodiment one of the utility model;

[0022] Figure 7 It is a structural schematic diagram of a surface acoustic wave resonant device of the embodiment two of the utility model;

[0023] Figure 8 It is a structural schematic diagram of a surface acoustic wave resonant device of the embodiment three of the utility model;

[0024] Figures 9 to 12 It is a structural schematic diagram of a surface acoustic wave resonant device of the embodiment four of the utility model;

[0025] Figures 13 to 14 It is a structural schematic diagram of a surface acoustic wave resonant device of the embodiment five of the utility model. DETAILED DESCRIPTION

[0026] It should be noted that in the utility model, "surface", "upper", are used to describe the relative position relationship in space, and are not limited to whether direct contact.

[0027] As described in the background, the performance of the surface acoustic wave resonator device needs to be improved. Now, a surface acoustic wave resonator device is described and analyzed.

[0028] Figure 1 And Figure 2 It is a structural schematic diagram of a surface acoustic wave resonator device.

[0029] Please refer to Figure 1 And Figure 2 , Figure 1 It is a top view structural schematic diagram omitting the protective layer, Figure 2 It is Figure 1 In the cross-sectional structural schematic diagram along the EE1 direction in the figure, the surface acoustic wave resonator device comprises: a piezoelectric substrate 100; an interdigital electrode structure 101 on the piezoelectric substrate 100; a protective layer 102 on the interdigital electrode structure 101.

[0030] In the above-mentioned surface acoustic wave resonator device, the acoustic wave can excite a high-order transverse mode, and generate spurious waves between the resonant frequency and the anti-resonant frequency of the resonator, which significantly deteriorates the performance in the passband of the filter.

[0031] In order to solve the above-mentioned problems, the technical scheme of the utility model provides a surface acoustic wave resonator device, by setting a first load part and a second load part on the opposite ends of the overlapping area along the first direction respectively, so that the acoustic wave velocity of the interdigital electrode structure end area is smaller than that of the middle area, thereby forming a piston mode, which can effectively suppress the high-order transverse parasitic mode and improve the quality factor (Q) of the surface acoustic wave resonator device. In addition, the first load part and the interdigital electrode structure have a first distance, and the second load part and the interdigital electrode structure have a second distance, which limits the first distance and the second distance, avoiding the electrostatic breakdown caused by the too small first distance or the too small second distance.

[0032] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific embodiments of the utility model will be described in detail below with reference to the drawings.

[0033] Figures 3 to 6 It is a structural schematic diagram of a surface acoustic wave resonator device according to the first embodiment of the utility model.

[0034] Please refer to Figures 3 to 6 , Figure 3 It is a top view structural schematic diagram showing the interdigital electrode structure, Figure 4 It is a top view structural schematic diagram omitting the first dielectric layer and the second dielectric layer, Figure 5 It is Figure 4 In the cross-sectional structural schematic diagram along the MM1 direction in the figure,Figure 6 For Figure 4 Fig. 9 is a schematic view of a cross-sectional structure along the direction of NN1 of a surface acoustic wave resonator device, which includes a piezoelectric layer 200, an interdigital electrode structure on a surface of the piezoelectric layer 200, the interdigital electrode structure having a first thickness d1, the interdigital electrode structure including a first bus 211 and a second bus 212 arranged in parallel along a first direction X, a plurality of first electrode strips 221 connected to the first bus 211, and a plurality of second electrode strips 222 connected to the second bus 212, the plurality of first electrode strips 221 and the plurality of second electrode strips 222 being parallel to the first direction X and arranged along a second direction Y, the first direction X and the second direction Y being perpendicular to each other, the plurality of first electrode strips 221 and the plurality of second electrode strips 222 being arranged in an interlaced manner, the first bus 211 and the second bus 212 having a first gap region g1, an overlap region c, and a second gap region g2 arranged in sequence along the first direction X, the first electrode strips 221 and the second electrode strips 222 overlapping each other along the second direction Y in the overlap region c.

[0035] The first electrode strips 221 include a first overlap portion and a first extension portion 2210, the first overlap portion being located in the overlap region c, the first extension portion 2210 being located in the first gap region g1, the first overlap portion including a first terminal portion 2211 and a second terminal portion 2212 opposite to each other in the first direction X, and a first intermediate portion 221c located between the first terminal portion 2211 and the second terminal portion 2212, the first terminal portion 2211 being connected to the first extension portion 2210, the first extension portion 2210 being connected to the first bus 211, the second electrode strips 222 include a second overlap portion and a second extension portion 2220, the second overlap portion being located in the overlap region c, the second extension portion 2220 being located in the second gap region g2, the second overlap portion including a third terminal portion 2223 and a fourth terminal portion 2224 opposite to each other in the first direction X, and a second intermediate portion 222c located between the third terminal portion 2223 and the fourth terminal portion 2224, the fourth terminal portion 2224 being connected to the second extension portion 2220, the second extension portion 2220 being connected to the second bus 212, the third terminal portion 2223 and the first bus 211 having the first gap (not shown in the figure) therebetween, the second terminal portion 2212 and the second bus 212 having the second gap (not shown in the figure) therebetween.

[0036] A first dielectric layer 201 is located on the piezoelectric layer 200, and covers the interdigital electrode structure; a first load portion 202 and a second load portion 203 are located on the first dielectric layer 201, and are respectively located on opposite ends of the overlapping region c in the first direction X, and have a first distance h1 between the first load portion 202 and the interdigital electrode structure, and a second distance h2 between the second load portion 203 and the interdigital electrode structure, wherein the ratio of the first distance h1 to the first thickness d1 is greater than 0.5, and the ratio of the second distance h2 to the first thickness d1 is greater than 0.5; a second dielectric layer 204 is located on the first dielectric layer 201, and covers the first load portion 202 and the second load portion 203.

[0037] Here, by respectively arranging the first load portion 202 and the second load portion 203 on opposite ends of the overlapping region c in the first direction X, the acoustic wave speed of the end region of the interdigital electrode structure is made to be less than the acoustic wave speed of the middle region, thereby forming a piston mode, which can effectively suppress high-order transverse parasitic modes and improve the quality factor (Q) of the surface acoustic wave resonator. In addition, the first distance h1 between the first load portion 202 and the interdigital electrode structure, and the second distance h2 between the second load portion 203 and the interdigital electrode structure are limited, which avoids electrostatic breakdown caused by the first distance h1 being too small or the second distance h2 being too small.

[0038] In this embodiment, the first load portion 202 is located on a plurality of first terminal portions 2211 and a plurality of third terminal portions 2223, and the second load portion 203 is located on a plurality of second terminal portions 2212 and a plurality of fourth terminal portions 2224, wherein the first distance h1 is between the first load portion 202 and the first terminal portion 2211, and the first distance h1 is between the first load portion 202 and the third terminal portion 2223; the second distance h2 is between the second load portion 203 and the second terminal portion 2212, and the second distance h2 is between the second load portion 203 and the fourth terminal portion 2224.

[0039] The density of the first load portion 202 and the second load portion 203 is greater than the density of the first dielectric layer 201, and the density of the first load portion 202 and the second load portion 203 is greater than the density of the second dielectric layer 204, so as to reduce the acoustic speed of the corresponding end region and suppress high-order transverse modes.

[0040] The material of the first load part 202 and the second load part 203 includes metal, which can be aluminum, copper, copper-aluminum alloy, platinum, molybdenum, etc., or insulating medium material or semiconductor material.

[0041] In the embodiment, the material of the first medium layer 201 and the second medium layer 204 can be silicon dioxide, silicon nitride, silicon oxynitride, or doped silicon oxide, the dopant including one or both of carbon and fluorine, to play a role of temperature compensation.

[0042] The material of the first medium layer 201 and the second medium layer 204 can be the same or different. In the embodiment, the first medium layer 201 and the second medium layer 204 adopt the same material.

[0043] In other embodiments, the material of the first medium layer and the second medium layer is different, and the first medium layer and the second medium layer can play a role of protecting the interdigital electrode structure.

[0044] In the embodiment, the first load part 202 includes a plurality of first load sub-parts (not shown in the figure), and one first load sub-part is located on one first electrode strip 221 or one second electrode strip 222; the second load part includes a plurality of second load sub-parts (not shown in the figure), and one second load sub-part is located on one first electrode strip 221 or one second electrode strip 222.

[0045] In another embodiment, the first load part extends along the second direction, and the first load part spans a plurality of first electrode strips and a plurality of second electrode strips; the second load part extends along the second direction, and the second load part spans a plurality of first electrode strips and a plurality of second electrode strips.

[0046] In yet another embodiment, the first load part also extends to the first gap region; and the second load part also extends to the second gap region.

[0047] In the embodiment, a plurality of first electrode strips 221 and a plurality of second electrode strips 222 are uniformly arranged along the second direction Y with an arrangement period L, and the arrangement period L is the center distance between adjacent first electrode strips 221 or the center distance between adjacent second electrode strips 222. Here, the arrangement period L is equal to the wavelength of the acoustic wave excited by the interdigital electrode structure.

[0048] In the embodiment, the first load part 202 has a first width w1 in the first direction X, and the ratio of the first width w1 to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 1:10 to 2:1.

[0049] In the embodiment, the second load part 203 has a second width w2 in the first direction X, and the ratio of the second width w2 to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 1:10 to 2:1.

[0050] In the embodiment, the first width w1 and the second width w2 are equal.

[0051] In other embodiments, the first width w1 and the second width w2 can not be equal.

[0052] In the embodiment, the thickness m1 of the first load part 202 ranges from 0.2% to 10% of the wavelength of the acoustic wave excited by the interdigital electrode structure.

[0053] In the embodiment, the thickness m2 of the second load part 203 ranges from 0.2% to 10% of the wavelength of the acoustic wave excited by the interdigital electrode structure.

[0054] In the embodiment, the first load part 202 and the second load part 203 are located in the same layer, and the first distance h1 is equal to the second distance h2.

[0055] In another embodiment, the first load part and the second load part are located in different layers, the second medium layer includes a first sub-medium layer and a second sub-medium layer located on the surface of the first sub-medium layer, the first load part is located on the surface of the first medium layer, and the second load part is located on the surface of the first sub-medium layer.

[0056] Figure 7 FIG. 2 is a structural schematic diagram of a surface acoustic wave resonant device according to the second embodiment of the present application.

[0057] The main difference between the embodiment and the first embodiment is the structure of the first load part and the second load part.

[0058] It should be noted that, in addition to the first load part and the second load part, the structure of the surface acoustic wave resonant device can continue to refer to the drawings and the related description of the first embodiment, and will not be repeated here.

[0059] Please continue to refer to Figure 3 on the basis of Figure 7 , the first load part 302 extends along the second direction Y, and the first load part 302 spans a plurality of the first electrode strips 221 and a plurality of the second electrode strips 222; the second load part 303 extends along the second direction Y, and the second load part 303 spans a plurality of the first electrode strips 221 and a plurality of the second electrode strips 222.

[0060] Compared with the previous embodiment, this embodiment is equivalent to connecting adjacent first load sub-parts and adjacent second load sub-parts. The manufacturing process of the first load part 302 and the second load part 303 is easier, and the reduction of sound velocity in the end region is more obvious.

[0061] Figure 8 This is a schematic diagram of the surface acoustic wave resonator device according to Embodiment 3 of this utility model.

[0062] The main difference between this embodiment and Embodiment 1 lies in the structure of the first load part and the second load part.

[0063] It should be noted that, apart from the first load part and the second load part, the structure of the surface acoustic wave resonator device is further described in the accompanying drawings and related descriptions of Embodiment 1, and will not be repeated here.

[0064] Please Figure 3 Based on this, continue to refer to Figure 8 The first load portion 402 extends to the first gap region g1; the second load portion 403 extends to the second gap region g2.

[0065] In this embodiment, the first load portion 402 extends along the second direction Y, spans a plurality of first electrode strips 221 and a plurality of second electrode strips 222, and extends to a portion of the first gap region g1. The second load portion 403 extends along the second direction Y, spans a plurality of first electrode strips 221 and a plurality of second electrode strips 222, and extends to a portion of the second gap region g2.

[0066] Compared with the previous embodiment, the first load portion 3051 and the second load portion 3052 in this embodiment reduce the sound velocity in the end region more significantly.

[0067] In another embodiment, the first load portion may include a plurality of first load sub-portions, one of which is located on a first electrode strip or a second electrode strip and extends to the first gap; the second load portion may include a plurality of second load sub-portions, one of which is located on a first electrode strip or a second electrode strip and extends to the second gap.

[0068] Figures 9 to 12 This is a schematic diagram of the surface acoustic wave resonator device according to Embodiment 4 of this utility model.

[0069] The main difference between this embodiment and Embodiment 1 is:

[0070] In the embodiment, the interdigital electrode structure further comprises a plurality of first dummy electrode strips and a plurality of second dummy electrode strips.

[0071] Compared with the previous embodiment, the first dummy electrode strips and the second dummy electrode strips are added to reduce the leakage of acoustic energy.

[0072] It should be noted that the structure of the surface acoustic wave resonator device other than the interdigital electrode structure can refer to the drawings and related descriptions of Embodiment 1, which will not be repeated here.

[0073] Please refer to Figures 9 to 12 , Figure 9 is a top view structural schematic diagram of the interdigital electrode structure, Figure 10 is a top view structural schematic diagram in which the first dielectric layer and the second dielectric layer are omitted, Figure 11 is Figure 10 is a cross-sectional structural schematic diagram along the OO1 direction, Figure 12 is Figure 10A schematic view of a cross-sectional structure along a direction of PP1, the surface acoustic wave resonator device comprising: a piezoelectric layer 600; an interdigital electrode structure on a surface of the piezoelectric layer 600, the interdigital electrode structure having a first thickness d1, the interdigital electrode structure comprising a first bus 611 and a second bus 612 arranged in parallel along a first direction X, a plurality of first electrode strips 621 connected to the first bus 611, and a plurality of second electrode strips 622 connected to the second bus 612, the plurality of first electrode strips 621 and the plurality of second electrode strips 622 being parallel to the first direction X and arranged along a second direction Y, the first direction X and the second direction Y being perpendicular to each other, the plurality of first electrode strips 621 and the plurality of second electrode strips 622 being arranged in an interleaved manner, the first bus 611 and the second bus 612 having a first gap region G1, an overlap region C, and a second gap region G2 arranged in sequence along the first direction X, the first electrode strips 621 and the second electrode strips 622 overlapping each other along the second direction Y in the overlap region C, the first electrode strips 621 comprising a first coincident portion and a first extension 6210, the first coincident portion being located in the overlap region C, the first extension 6210 being located in the first gap region G1, the first coincident portion comprising a first terminal portion 6211 and a second terminal portion 6212 opposite to each other along the first direction X, and a first intermediate portion 621c located between the first terminal portion 6211 and the second terminal portion 6212, the first terminal portion 6211 being connected to the first extension 6210, the first extension 6210 being connected to the first bus 611, the second electrode strips 622 comprising a second coincident portion and a second extension 6220, the second coincident portion being located in the overlap region C, the second extension 6220 being located in the second gap region G2, the second coincident portion comprising a third terminal portion 6223 and a fourth terminal portion 6224 opposite to each other along the first direction X, and a second intermediate portion 622c located between the third terminal portion 6223 and the fourth terminal portion 6224, the fourth terminal portion 6224 being connected to the second extension 6220, the second extension 6220 being connected to the second bus 612; a first dielectric layer 601 on the piezoelectric layer 600, the first dielectric layer 601 covering the interdigital electrode structure;A first load part 602 and a second load part 603 are located on the first dielectric layer 601, the first load part 602 is located on the first terminal part 6211 and the third terminal part 6223, the second load part 603 is located on the second terminal part 6212 and the fourth terminal part 6224, the first distance h1 between the first load part 602 and the interdigital electrode structure is greater than 0.5 times the first thickness d1, the second distance h2 between the second load part 603 and the interdigital electrode structure is greater than 0.5 times the first thickness d1; a second dielectric layer 604 is located on the first dielectric layer 601, the second dielectric layer 604 covers the first load part 602 and the second load part 603.

[0074] In the embodiment, the interdigital electrode structure further comprises: a plurality of first dummy electrode strips 631 connected with the first bus 611, the first dummy electrode strip 623 and the second electrode strip 622 have a third gap, a plurality of the first dummy electrode strips 631 are parallel to the first direction X, and the first dummy electrode strips 631 and the first electrode strips 621 are staggered and spaced apart; a plurality of second dummy electrode strips 632 connected with the second bus 612, the second dummy electrode strip 632 and the first electrode strip 621 have a fourth gap, a plurality of the second dummy electrode strips 632 are parallel to the first direction X, and the second dummy electrode strips 632 and the second electrode strips 622 are staggered and spaced apart.

[0075] In the embodiment, the first load part 602 further extends to the first dummy electrode strip 631; the second load part 603 further extends to the second dummy electrode strip 632.

[0076] In another embodiment, the first load part can not extend to the first dummy electrode strip; the second load part can not extend to the second dummy electrode strip.

[0077] In the embodiment, the first load part 602 comprises a plurality of first load sub-parts, one first load sub-part is located on one first electrode strip 621 or one second electrode strip 622; the second load part comprises a plurality of second load sub-parts, one second load sub-part is located on one first electrode strip 621 or one second electrode strip 622.

[0078] In another embodiment, the first load portion extends along the second direction and spans a number of the first electrode strips and a number of the second electrode strips, and the second load portion extends along the second direction and spans a number of the first electrode strips and a number of the second electrode strips.

[0079] Figures 13 to 14 Figure 1 is a structural schematic diagram of a surface acoustic wave resonator according to an embodiment of the present application.

[0080] The main difference between the present embodiment and the first embodiment is that:

[0081] In the above embodiment, the first load portion and the second load portion are located in the same layer.

[0082] In the present embodiment, the first load portion and the second load portion can be located in different layers.

[0083] Here, in comparison with the above embodiment, the parameters (e.g., material, thickness, width, etc.) of the first load portion and the second load portion are set differently, so that the resonant frequencies of the first load layer and the second load layer are differentiated, so that the parasitic resonances introduced by the first load layer and the second load layer can be offset or partially offset from each other, thereby weakening the splitting parasitics caused by the introduction of the first load layer and the second load layer.

[0084] In the present embodiment, the piezoelectric layer and the interdigital electrode structure please continue to refer to Figure 3 , and on the basis of Figure 3 , continue to refer to Figure 13 and Figure 14 , Figure 13 is a top view structural schematic diagram, Figure 14 is Figure 13The surface acoustic wave resonant device further comprises: a first dielectric layer 701 on the piezoelectric layer 200, the first dielectric layer 701 covering the interdigital electrode structure; a first load part 702 and a second load part 703 on the first dielectric layer 701, the first load part 702 being on the first terminal part 2211 and the third terminal part 2223, the second load part 703 being on the second terminal part 2212 and the fourth terminal part 2224, the first load part 702 and the interdigital electrode structure having a first distance h1 in a direction perpendicular to the surface of the piezoelectric layer 200, the second load part 703 and the interdigital electrode structure having a second distance h2 in the direction perpendicular to the surface of the piezoelectric layer 200, the ratio of the first distance h1 to the first thickness d1 being greater than 0.5, the ratio of the second distance h2 to the first thickness d1 being greater than 0.5; a second dielectric layer 704 on the first dielectric layer 701, the second dielectric layer 704 covering the first load part 702 and the second load part 703.

[0085] In the embodiment, the first distance h1 and the second distance h2 are different, the second dielectric layer 704 comprises a first sub-dielectric layer 7041 and a second sub-dielectric layer 7042 on the surface of the first sub-dielectric layer 7041, the first load part 702 is on the surface of the first dielectric layer 701, and the second load part 703 is on the surface of the first sub-dielectric layer 7041.

[0086] Although the utility model discloses as above, the utility model is not limited to this. Any person skilled in the art, without departing from the spirit and scope of the utility model, can make various changes and modifications, therefore the protection scope of the utility model should be the range limited by claim.

Claims

1. A surface acoustic wave resonator device, characterized by, The piezoelectric layer comprises: an interdigital electrode structure on a surface of the piezoelectric layer, the interdigital electrode structure having a first thickness, the interdigital electrode structure comprising a first bus and a second bus arranged in parallel along a first direction, a plurality of first electrode strips connected to the first bus, and a plurality of second electrode strips connected to the second bus, the plurality of first electrode strips and the plurality of second electrode strips being parallel to the first direction and arranged along a second direction, the first direction and the second direction being perpendicular to each other, the plurality of first electrode strips and the plurality of second electrode strips being arranged in an interleaved manner, the first bus and the second bus having a first gap region, an overlapping region, and a second gap region arranged in sequence along the first direction, the first electrode strips and the second electrode strips overlapping each other along the second direction in the overlapping region; a first dielectric layer on the piezoelectric layer, the first dielectric layer covering the interdigital electrode structure, a first load portion and a second load portion on the first dielectric layer, the first load portion and the second load portion being located on opposite ends of the overlapping region along the first direction, the first load portion and the interdigital electrode structure having a first distance in a direction perpendicular to the surface of the piezoelectric layer, the second load portion and the interdigital electrode structure having a second distance in the direction perpendicular to the surface of the piezoelectric layer, a ratio of the first distance to the first thickness being greater than 0.5, and a ratio of the second distance to the first thickness being greater than 0.5; a second dielectric layer on the first dielectric layer, the second dielectric layer covering the first load portion and the second load portion. The first electrode strips comprise a first coincident portion and a first extension portion, the first coincident portion being located in the overlapping region, the first extension portion being located in the first gap region, the first coincident portion comprising a first terminal portion and a second terminal portion opposite to each other along the first direction, and a first intermediate portion between the first terminal portion and the second terminal portion, the first terminal portion being connected to the first extension portion, and the first extension portion being connected to the first bus, the second electrode strips comprising a second coincident portion and a second extension portion, the second coincident portion being located in the overlapping region, the second extension portion being located in the second gap region, the second coincident portion comprising a third terminal portion and a fourth terminal portion opposite to each other along the first direction, and a second intermediate portion between the third terminal portion and the fourth terminal portion, the fourth terminal portion being connected to the second extension portion, and the second extension portion being connected to the second bus, the third terminal portion and the first bus having a first gap therebetween, and the second terminal portion and the second bus having a second gap therebetween, the first load portion being located on the plurality of first terminal portions and the plurality of third terminal portions, and the second load portion being located on the plurality of second terminal portions and the plurality of fourth terminal portions.

2. The SAW resonator device of claim 1, wherein, ​ 3. The SAW resonator device of claim 2, wherein, The first load part has the first distance with the first terminal part and the third terminal part; the second load part has the second distance with the second terminal part and the fourth terminal part.

4. The SAW resonator device of claim 1, wherein, The first load part comprises a plurality of first load sub-parts, one of which is located on one of the first electrode strips or one of the second electrode strips; the second load part comprises a plurality of second load sub-parts, one of which is located on one of the first electrode strips or one of the second electrode strips.

5. The SAW resonator device of claim 1, wherein, The first load part extends along the second direction and spans the first electrode strips and the second electrode strips; the second load part extends along the second direction and spans the first electrode strips and the second electrode strips.

6. The SAW resonator device of claim 1, wherein, The interdigital electrode structure further comprises: a plurality of first dummy electrode strips connected to the first bus, the first dummy electrode strips and the second electrode strips having third gaps therebetween, the first dummy electrode strips being parallel to the first direction and being staggered and spaced apart from the first electrode strips; and a plurality of second dummy electrode strips connected to the second bus, the second dummy electrode strips and the first electrode strips having fourth gaps therebetween, the second dummy electrode strips being parallel to the first direction and being staggered and spaced apart from the second electrode strips.

7. The SAW resonator device of claim 6, wherein, The first load part further extends onto the first dummy electrode strips; and the second load part further extends onto the second dummy electrode strips.

8. The SAW resonator device as claimed in claim 1, wherein, The first load part further extends onto the first gap regions; and the second load part further extends onto the second gap regions.

9. The SAW resonator device as claimed in claim 1, wherein, The first load part has a first width in the first direction, the ratio of the first width to the wavelength of the acoustic wave excited by the interdigital electrode structure being in the range of 1:10 to 2:1; and the second load part has a second width in the first direction, the ratio of the second width to the wavelength of the acoustic wave excited by the interdigital electrode structure being in the range of 1:10 to 2:

1.

10. The SAW resonator device as claimed in claim 1, wherein, The thickness of the first load part is in the range of 0.2% to 10% of the wavelength of the acoustic wave excited by the interdigital electrode structure; and the thickness of the second load part is in the range of 0.2% to 10% of the wavelength of the acoustic wave excited by the interdigital electrode structure.

11. The SAW resonator device as claimed in claim 1, wherein, The first distance is equal to the second distance.

12. The SAW resonator device as claimed in claim 1, wherein, The second dielectric layer comprises a first sub-dielectric layer and a second sub-dielectric layer located on the surface of the first sub-dielectric layer, the first load part is located on the surface of the first dielectric layer, and the second load part is located on the surface of the first sub-dielectric layer.

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