Acoustic wave device and method of manufacturing the same

Abstract

An acoustic wave device includes a piezoelectric substrate and a transducer. The piezoelectric substrate has a surface. The transducer is disposed on the surface of the piezoelectric substrate. The transducer includes a first electrode, a second electrode, and at least one protrusion. The first electrode extends along a first direction and has a first end. The second electrode extends along the first direction and has a second end. The second electrode is spaced apart from the first electrode along a second direction. The at least one protrusion is disposed at the first end of the first electrode. The at least one protrusion extends along the first direction and does not completely cover the first end.

Description

Technical Field

[0001] This invention relates to radio frequency communication, and in particular to an acoustic device for use in radio frequency communication and a method for manufacturing the same. Background Technology

[0002] Acoustic wave devices, such as surface acoustic wave (SAW) devices, can be used for the conversion and transmission of electrical and acoustic signals. Acoustic wave devices have numerous applications. For example, they can be used as filters to remove noise and retain wireless signals in specific frequency bands. They are characterized by low transmission loss, good resistance to electromagnetic interference, and small size, and are therefore widely used in various communication products. However, due to manufacturing errors, existing SAW devices experience energy leakage, resulting in a decrease in quality factor. Furthermore, acoustic wave devices can also be used as resonators. Summary of the Invention

[0003] This invention provides an acoustic wave device comprising a piezoelectric substrate and a transducer. The piezoelectric substrate has a surface. The transducer is disposed on the surface of the piezoelectric substrate. The transducer includes a first electrode, a second electrode, and at least one first protrusion. The first electrode extends along a first direction and has a first end. The second electrode extends along the first direction and has a second end, and the second electrode and the first electrode are spaced apart along a second direction. At least one first protrusion is disposed at the first end of the first electrode, and the at least one first protrusion extends along the first direction and does not completely cover the first end.

[0004] This invention provides another method for manufacturing an acoustic wave device, comprising providing a piezoelectric substrate having a surface, forming a conductive layer on the surface, and patterning the conductive layer using a mask to form a patterned conductive layer. The step of forming the patterned conductive layer includes forming a first electrode along a first direction, the first electrode having a first end, forming at least one first protrusion at the first end of the first electrode, the at least one first protrusion extending along the first direction and not completely covering the first end, and forming a second electrode along the first direction, the second electrode having a second end, wherein the second electrode and the first electrode are spaced apart along a second direction. Attached Figure Description

[0005] Figure 1 This is a top view of the acoustic device in an embodiment of the present invention. Figure 2 for Figure 1 A schematic diagram of a transducer section of a sound wave device. Figure 3 To form Figure 2 A schematic diagram of the shielding for the transducer section of the acoustic wave device. Figure 4 for Figure 1A schematic diagram of another transducer section of the acoustic device. Figure 5 for Figure 1 A schematic diagram of another transducer section of the acoustic device. Figure 6 for Figure 1 A schematic diagram of another transducer section of the acoustic device. Figure 7 and Figure 8 for Figure 1 A schematic diagram of the manufacturing method of the acoustic device. Figure 9 for Figure 1 A flowchart of the manufacturing method of the acoustic device in the diagram. Symbol Explanation 1 Surface acoustic wave device 10 Piezoelectric substrate 11 Transducers Busbars 121 to 122 Electrodes 131 to 133, 141 to 143 1311 to 1331, 1411 to 1431, 4311 and 4312, Protrusion 5311,6311 131e and 141e end 151 to 153, 161 to 163 Pseudo-electrodes 1511 to 1531, 1611 to 1631, 4511 to 4513, pseudo-protrusion 5511, 6511 151e and 161e pseudoterminal Directions D1 and D2 351,331 Pattern mask 3511, 3512, 3311 and 3312 Shielding Attachments 70, 72, 74 solder pads 80 Bridging Layer 82 Connection Layer 84 Passivation layer 900 Manufacturing Method S902 to S912 Steps Distance from d1 to d3 Detailed Implementation

[0006] Figure 1This is a top view of an acoustic wave device, such as a surface acoustic wave (SAW) device 1, according to an embodiment of the present invention. In some embodiments, the SAW device 1 can be used in a radio frequency (RF) front-end circuit to receive RF signals, filter the RF signals to generate a filtered signal. For example, the SAW device 1 can receive RF signals from an antenna, filter the RF signals to generate a filtered signal, and output the filtered signal to a receiver. The use of the SAW device 1 is only illustrative here, but the present invention is not limited thereto; in other embodiments, the SAW device 1 can also be used for other purposes.

[0007] SAW device 1 may include a piezoelectric substrate 10 and a transducer 11. The piezoelectric substrate 10 may include a substrate and a piezoelectric material layer disposed on the substrate. For example, the substrate of the piezoelectric substrate may include a silicon substrate. The piezoelectric material layer may include piezoelectric single crystals, piezoelectric polycrystalline materials (piezoelectric ceramics), piezoelectric polymers, and piezoelectric composite materials. The piezoelectric material layer may, for example, include zinc oxide (ZnO), aluminum nitride (AlN), lithium tantalate (LiTaO3), and combinations thereof. The transducer 11 may include a metallic material, which may include any combination of molybdenum (Mo), copper (Cu), aluminum (Al), gold (Au), platinum (Pt), and tungsten (W).

[0008] In some embodiments, the transducer 11 may be disposed on the surface of the piezoelectric substrate 10 and include at least one pair of interdigital structures, which are not directly connected and have gaps between them. For example, the pair of interdigital structures may include a first set of interdigital structures and a second set of interdigital structures, such as... Figure 1 As shown, the first set of interdigitated structures may include a busbar 121, electrodes 131 to 133, and dummy electrodes 161 to 163, and the second set of interdigitated structures may include a busbar 122, electrodes 141 to 143, and dummy electrodes 151 to 153.

[0009] In the illustrated embodiment, electrodes 131 to 133 and 141 to 143 extend along direction D1, and busbars 121 and 122 extend along direction D2. In some embodiments, electrodes 131 to 133 may serve as the interdigitated fingers of a first set of interdigitated structures, and electrodes 141 to 143 may serve as the interdigitated fingers of a second set of interdigitated structures. The first set of interdigitated structures and the second set of interdigitated structures are interdigitated along direction D1. Along direction D2, adjacent interdigitated fingers (i.e., electrodes) are spaced apart, that is, there is a gap between adjacent interdigitated fingers. For example, electrodes 131, 141, 132, 142, 133, and 143 may be sequentially spaced apart along direction D2. Further, electrodes 131 to 133 may extend along direction D1 starting from busbar 121, and electrodes 141 to 143 may extend along direction D1 starting from busbar 122. In this embodiment, for example, electrodes 131 and 141 have ends 131e and 141e, respectively, and other electrodes 132, 142, 133, and 143 also have ends (not shown in the figure). In the above embodiment, direction D2 may be perpendicular to direction D1, but the invention is not limited thereto. In other embodiments, direction D2 and direction D1 may form an angle other than 90 degrees. In the above embodiment, both direction D1 and direction D2 are parallel to the surface of the piezoelectric substrate 10.

[0010] In a further embodiment, dummy electrodes 151 to 153 may extend from the busbar 122 along direction D1 and are respectively aligned with electrodes 131 to 133. Dummy electrodes 161 to 163 may extend from the busbar 121 along direction D1 and are respectively aligned with electrodes 141 to 143. In this embodiment, for example, dummy electrodes 151 and 161 have dummy ends 151e and 161e, respectively, and other dummy electrodes 152, 162, 153, and 163 also have dummy ends (not shown in the figure). In detail, electrode 131 may be aligned with dummy electrode 151, and there is a gap between them. In other words, the end 131e of electrode 131 may be aligned with the dummy end 151e of dummy electrode 151, and there is a gap between them. Electrode 141 and dummy electrode 161, electrode 132 and dummy electrode 152, electrode 142 and dummy electrode 162, electrode 133 and dummy electrode 153, and / or electrode 143 and dummy electrode 163 each have gaps and can be set up similarly to electrode 131 and dummy electrode 151, which will not be elaborated here.

[0011] In the above embodiments, dummy electrodes 151 to 153 and / or 161 to 163 are provided to reduce sound wave leakage along direction D1. However, the present invention is not limited thereto. In other embodiments, dummy electrodes 151 to 153 and / or 161 to 163 may be omitted. In such embodiments, the ends of electrodes 131 to 133 have gaps between them and the busbar 122, and the ends of electrodes 141 to 143 have gaps between them and the busbar 121.

[0012] In some embodiments, transducer 11 can be used as an input transducer or an output transducer. Taking the input transducer as an example, an electrical signal can be input from bus 121 / 122, converted into an acoustic signal via the piezoelectric substrate 10 and its electrodes 131, 141, 132, 142, 133, and 143, and the acoustic signal can propagate along direction D2. In other embodiments, transducer 11 can also be used as an output transducer that converts the acoustic signal into an electrical signal. The ends 131e to 133e aligned along direction D2 and the ends 141e to 143e aligned along direction D2 can be used to define the effective propagation range of the acoustic signal. Specifically, with Figure 1 Taking the direction shown as an example, the virtual straight line connecting the ends 131e, 132e, and 133e can be the upper boundary of the effective sound signal transmission range, and the virtual straight line connecting the ends 141e, 142e, and 143e can be the lower boundary of the effective sound signal transmission range.

[0013] In some embodiments, the SAW device 1 can operate in piston mode, minimizing or eliminating energy leakage through the gaps between electrodes 131-133 and dummy electrodes 151-153, and between electrodes 141-143 and dummy electrodes 161-163, respectively. Experiments have shown that when, for example, the gaps between electrode 131 and dummy electrode 151, and / or between electrode 141 and dummy electrode 161, are smaller, the energy leakage of the sound wave along direction D1 is also smaller. Therefore, the SAW device 1 can have a better quality factor (Q factor). To obtain smaller gaps, optical proximity correction (OPC) can be used to correct the ends of each electrode and / or the dummy ends of the dummy electrodes. For example, using OPC, the shape of the ends of electrodes 131-133 can be corrected to be close to rectangular (e.g., right-angled), and / or the shape of the dummy ends of dummy electrodes 151-153 can be corrected to be close to rectangular. Similarly, the shape of the ends or pseudo-ends of electrodes 141 to 143 and / or dummy electrodes 161 to 163 can be modified to approximate a rectangle, thereby optimizing or reducing the distance between the electrode and the corresponding dummy electrode, or optimizing or reducing the distance between the electrode and the corresponding busbar in the absence of dummy electrodes. For example, in the presence of dummy electrodes, the distance between electrode 131 and dummy electrode 151, and / or the distance between electrode 141 and dummy electrode 161 can be shortened. In the OPC method, errors caused by light diffraction or other process effects can be compensated by adding mask attachments at the corners, ends, and / or edges of the pattern mask. The shape of these mask attachments can be, for example, polygonal, as will be described in later paragraphs.

[0014] In some embodiments, via OPC, for example, a protrusion 1311 may be formed at the end 131e of electrode 131, and / or a pseudo-protrusion 1511 may be formed at the pseudo end 151e of pseudo electrode 151. Further, a protrusion 1411 may be formed at the end 141e of electrode 141, and / or a pseudo-protrusion 1611 may be formed at the pseudo end 161e of pseudo electrode 161. Similarly, protrusions 1321-1331 and 1421-1431 may also be formed at the ends of electrodes 132-133 and 142-143, and / or pseudo-protrusions 1521-1531 and 1621-1631 may also be formed at the ends of pseudo electrodes 152-153 and 162-163, respectively.

[0015] In some embodiments, the electrode 131 extends from the busbar 121 along direction D1 to the end point 131e, and a protrusion 1311 may be disposed at the end point 131e of the electrode 131, and may extend from the end point 131e along direction D1. For example... Figure 1As shown, the protrusion 1311 does not completely cover the end 131e. As also shown, a dummy protrusion 1511 can be provided at the dummy end 151e of the dummy electrode 151, and can extend from the dummy end 151e along direction D1. Figure 1 As shown, the dummy protrusion 1511 does not completely cover the dummy end 151e. The gap formed between the end 131e and the dummy end 151e can be defined as a first gap, and the protrusion 1311 and the dummy protrusion 1511 can be disposed in the first gap. In some embodiments, the protrusion 1311 and the dummy protrusion 1511 can be spaced apart along direction D2, for example, alternately disposed sequentially along direction D2. Similarly, the electrode 141 extends from the busbar 122 along direction D1 to the end 141e, and the protrusion 1411 can be disposed at the end 141e of the electrode 141 and can extend from the end 141e along direction D1. The protrusion 1411 does not completely cover the end 141e. The dummy protrusion 1611 can be disposed at the dummy end 161e of the dummy electrode 161 and can extend from the dummy end 161e along direction D1. The dummy protrusion 1611 does not completely cover the dummy end 161e. The gap formed between the end 141e and the pseudo-end 161e can be defined as a second gap, and the protrusion 1411 and the pseudo-protrusion 1611 can be disposed in the second gap. In some embodiments, the protrusion 1411 and the pseudo-protrusion 1611 can be disposed at intervals along direction D2, for example, alternately disposed sequentially along direction D2.

[0016] exist Figure 1 In the illustrated embodiment, along direction D2, the protrusion 1311 is positioned to the right relative to the end 131e of the electrode 131, but the invention is not limited thereto. In other embodiments, the protrusion 1311 may be positioned to the left or center relative to the end 131e of the electrode 131. Similarly, the pseudo-protrusion 1511 may be positioned to the right or center relative to the pseudo-end 151e of the pseudo-electrode 151. For example, when the protrusion 1311 is to the left relative to the end 131e, the pseudo-protrusion 1511 may be to the right relative to the pseudo-end 151e. Similarly, the protrusion 1411 may be positioned to the left, center, or right relative to the end 141e of the electrode 141, and / or the pseudo-protrusion 1611 may be positioned to the left, center, or right relative to the pseudo-end 161e of the pseudo-electrode 161.

[0017] In some embodiments, electrode 131 may be integrally formed with protrusion 1311, electrode 141 may be integrally formed with protrusion 1411, dummy electrode 151 may be integrally formed with dummy protrusion 1511, and / or electrode 161 may be integrally formed with dummy protrusion 1611.

[0018] In some embodiments, for example, the end 131e of electrode 131 may have a smooth surface, such as an arcuate surface, or a flat surface parallel to direction D2. For example, the size of the protrusion 1311 located at the end 131e along direction D2 may be 5% to 50% of the size of electrode 131 at the end 131e along direction D2, thereby achieving that the protrusion 1311 does not completely cover the end 131e. The size of the pseudo-protrusion 1511 along direction D2 may be 5% to 50% of the size of pseudo electrode 151 at pseudo end 151e along direction D2, thereby achieving that the pseudo-protrusion 1511 does not completely cover the pseudo end 151e. In the above embodiments, the sizes of the protrusion 1311 and the pseudo-protrusion 1511 along direction D2 may be equal or unequal. Similarly, the size of the protrusion 1411 along direction D2 can be 5% to 50% of the size of the electrode 141 at the end 141e along direction D2, and / or the size of the pseudo protrusion 1611 along direction D2 can be 5% to 50% of the size of the pseudo electrode 161 at the pseudo end 161e along direction D2.

[0019] By providing protrusions and / or dummy protrusions in the gaps, energy leakage from the electrode to the dummy electrode or from the electrode to the busbar can be reduced or eliminated, thereby improving the quality factor of the SAW device 1.

[0020] Although Figure 1 The first set of interdigitated structures in the SAW device 1 includes three electrodes (electrodes 131, 132, 133) and three dummy electrodes (dummy electrodes 161, 161, 163), and the second set of interdigitated structures includes three electrodes (electrodes 141, 142, 143) and three dummy electrodes (dummy electrodes 151, 152, 153). However, those skilled in the art can also modify the number of interdigitated structures in the SAW device 1 according to the principles of this invention to meet the needs of practical applications.

[0021] Figure 2 yes Figure 1 A schematic diagram of a transducer section of the SAW device 1. Figure 2 In this transducer, an electrode 131, a protrusion 1311, a dummy electrode 151, and a dummy protrusion 1511 are included. In some embodiments, the distance d1 between the protrusion 1311 and the dummy end 151e in direction D1 is at least 0.3 micrometers, the distance d2 between the protrusion 1311 and the dummy protrusion 1511 in direction D2 is at least 0.3 micrometers, and / or the distance d3 between the dummy protrusion 1511 and the end 131e in direction D1 is at least 0.3 micrometers. In the above embodiments, the distances d1, d2, and d3 may be equal or unequal. Similarly, the arrangement of the electrode 141, the protrusion 1411, the dummy electrode 161, and the dummy protrusion 1611 may be similar to... Figure 2 This will not be elaborated upon here.

[0022] exist Figure 2 In one embodiment, along direction D2, the protrusion 1311 and the pseudo-protrusion 1511 are spaced apart, for example, by a distance d2. Along direction D1, the protrusion 1311 and the pseudo-protrusion 1511 may partially overlap or not overlap; in other words, the orthographic projections of the protrusion 1311 and the pseudo-protrusion 1511 on a plane parallel to direction D1 may partially overlap or not overlap.

[0023] Figure 3 It is formed Figure 2 A schematic diagram of the shielding for the transducer section. Figure 3 The mask is an OPC mask, comprising pattern masks 351 and 331 and mask attachments 3511, 3512, 3311, and 3312. Mask attachments 3511 and 3512 can be located at two corners at the ends of pattern mask 351, and mask attachments 3311 and 3312 can be located at two corners at the ends of pattern mask 331. Pattern masks 351 and 331 can be used to form dummy electrodes 151 and electrodes 131, respectively. The formed dummy electrodes 151 and electrodes 131 can have right-angled, elliptical, arc-shaped, or other irregularly shaped ends. Mask attachment 3511 can be used to form a dummy protrusion 1511 at one corner of the end 151e of the dummy electrode 151. The smaller mask attachment 3512, relative to mask attachment 3511, can be used to compensate for the shape of the other corner of the end 151e of the dummy electrode 151, for example, to form a right angle. Therefore, the masking attachment 3512 can prevent over-etching at the other corner of the dummy electrode 151 end 151e. Similarly, the masking attachment 3312 can be used to form a protrusion 1311 at a corner of the electrode 131 end 131e. The smaller masking attachment 3311, relative to the masking attachment 3312, can be used to compensate for the shape of the other corner of the electrode 131 end 131e to form a right angle. Therefore, the masking attachment 3311 can prevent over-etching at the other corner of the electrode 131 end 131e. Figure 3 In the illustrated embodiment, the masking attachments 3511, 3512, 3311, and 3312 may be rectangular, with masking attachments 3511 and 3312 having substantially the same area, and masking attachments 3512 and 3311 having substantially the same area. However, the invention is not limited thereto. In other embodiments, the shapes of the masking attachments 3511, 3512, 3311, and 3312 may be different, the areas of masking attachments 3511 and 3312 may be different, and / or the areas of masking attachments 3512 and 3311 may be different. In some embodiments, Figure 3The mask can also be used to form electrodes 132-133, protrusions 1321-1331, dummy electrodes 152-153, dummy protrusions 1521-1531, electrodes 141-143, protrusions 1411-1431, dummy electrodes 161-163, and dummy protrusions 1611-1631, which will not be elaborated here.

[0024] In some embodiments, the mask attachments 3512 and 3311 can be from Figure 3 The mask is removed. In other embodiments, the mask may include mask attachments of other shapes or numbers to create protrusions and dummy protrusions of other shapes, thereby reducing the distance between electrode 131 and dummy electrode 151. For example, at least one of the protrusions and dummy protrusions of electrode 131 and dummy electrode 151 may have a plurality of square profiles, triangular profiles, or arcuate profiles, such as... Figures 4 to 6 As shown in the illustrated embodiment, the protrusion and the corresponding pseudo-protrusion have substantially the same shape, but the invention is not limited thereto.

[0025] Figures 4 to 6 This is a schematic diagram of the other transducer sections of the SAW device 1. Figure 4 The transducer of the SAW device 1 has a plurality of square-shaped protrusions at the ends of its electrodes and dummy electrodes. Further, the figure shows electrode 131, protrusions 4311 and 4312, dummy electrode 151, and dummy protrusions 4511 to 4513. Protrusions 4311 and 4312 and dummy protrusions 4511 to 4513 may be alternately arranged sequentially along direction D2. Protrusions 4311 and 4312 and dummy protrusions 4511 to 4513 may partially overlap or not overlap along direction D1. In some embodiments, the electrode portion of the transducer of the SAW device 1 may only include range 4a.

[0026] Figure 5 The transducer of the SAW device 1 has triangular protrusions at the ends of its electrodes and dummy electrodes. Further details are shown in the figure: electrode 131, protrusion 5311, dummy electrode 151, and dummy protrusion 5511. The protrusion 5311 and dummy protrusion 5511 can be alternately arranged sequentially along direction D2. The protrusion 5311 and dummy protrusion 5511 may partially overlap or not overlap along direction D1.

[0027] Figure 6 The transducer of the SAW device 1 has arc-shaped protrusions at the ends of its electrodes and dummy electrodes. Further details are shown in the figure: electrode 131, protrusion 6311, dummy electrode 151, and dummy protrusion 6511. Protrusion 6311 and dummy protrusion 6511 may be alternately arranged sequentially along direction D2. Protrusion 6311 and dummy protrusion 6511 may partially overlap or not overlap along direction D1.

[0028] In many embodiments, the materials of the busbars 121 and 122, electrodes 131 to 133 and electrodes 141 to 143, and / or dummy electrodes 151 to 153 and dummy electrodes 161 to 163 of the transducer 11 may include metals, wherein the metals may include any combination of molybdenum (Mo), copper (Cu), aluminum (Al), gold (Au), platinum (Pt) and tungsten (W).

[0029] Figure 7 and 8 This is a schematic diagram of the manufacturing method of SAW device 1. Figure 7 The piezoelectric substrate 10, pads 70, 72, 74, and electrodes 131 to 133, 141 to 143 of the transducer are displayed. The pads 70, 72, 74, and electrodes 131 to 133, 141 to 143 of the transducer can form a patterned conductive layer. For example, the transducer can be... Figure 1 The transducer 11 is located in the middle. Pads 70, 72, and 74 can be coupled to external electrical connections. Figure 8 Also shown are bridging layer 80, connecting layer 82 and passivation layer 84. Figure 9 This is a flowchart of a manufacturing method 900 for SAW device 1. Manufacturing method 900 includes steps S902 to S912 for manufacturing SAW device 1. Any reasonable changes, orders, or adjustments to the steps fall within the scope of this disclosure. Steps S902 to S912 are illustrated below: Step S902: Provide a piezoelectric substrate; Step S904: Form a conductive layer on the surface of the piezoelectric substrate; Step S906: Pattern the conductive layer using a mask to form a patterned conductive layer, the patterned conductive layer including a first electrode and a second electrode. Step S908: Form a first solder pad, a second solder pad, and a bridging layer, wherein the bridging layer is located between the first solder pad and the second solder pad; Step S910: Form a bonding layer that connects the first solder pad and the second solder pad; Step S912: Form a passivation layer, which is located on the interconnect layer, the first pad, the second pad, the first electrode, and the second electrode.

[0030] The following combinations Figure 7 and 8The step S906 of the manufacturing method 900 is explained illustratively. In step S906, the step of forming a patterned conductive layer includes forming an electrode 131 along direction D1, with the electrode 131 having an end 131e, and forming an electrode 141 along direction D1, with the electrode 141 having an end 141e, wherein the electrodes 131 and 141 are spaced apart along direction D2. The step of forming the patterned conductive layer further includes forming a protrusion 1311 at the end 131e of the electrode 131, the protrusion 1311 extending along direction D1 and not completely covering the end 131e. Furthermore, in step S906, a dummy electrode 151 is formed along direction D1. The dummy electrode 151 is aligned with the electrode 131 and has a dummy end 151e, wherein a first gap is formed between the end 131e and the dummy end 151e. At least one dummy protrusion 1511 is formed at the dummy end 151e of the dummy electrode 151. The at least one dummy protrusion 1511 extends along direction D1 and does not completely cover the dummy end 151e. The at least one protrusion 1311 and the at least one dummy protrusion 1511 are spaced apart along direction D2.

[0031] In a further embodiment, in step S906, the mask used may include a patterned mask for forming electrodes and / or dummy electrodes and at least one mask attachment. In the step of forming the patterned conductive layer, for example, the position of the at least one mask attachment may correspond to the end of the electrode 131 and / or dummy electrode 151, for forming protrusions and / or dummy protrusions at the end. Furthermore, the at least one mask attachment may also be used to modify the shape of the end of the electrode 131 and / or dummy electrode 151.

[0032] In some embodiments, electrodes 131 to 133, protrusions 1311 to 1331, electrodes 141 to 143, and protrusions 1411 to 1431 can be formed simultaneously using a mask. Furthermore, dummy electrodes 151 to 153, dummy protrusions 1511 to 1533, dummy electrodes 161 to 163, and / or dummy protrusions 1611 to 1631 can also be formed simultaneously. (Reference) Figure 8 After the patterned conductive layer is formed, a bridging layer 80 (S908), a connecting layer 82 (S910), and a passivation layer 84 (S912) are formed in sequence.

[0033] Manufacturing method 900 provides protrusions and / or pseudo-protrusions in the gap, which can reduce or eliminate gap energy leakage from the electrode to the pseudo-electrode or from the electrode to the busbar, thereby improving the quality factor of SAW device 1.

[0034] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included within the scope of the present invention.

Claims

1. An acoustic device, characterized in that, Include: A piezoelectric substrate having a surface; and A transducer is disposed on the surface of the piezoelectric substrate, the transducer comprising: A first electrode extends along a first direction and has a first end; A second electrode extends along the first direction and has a second end, the second electrode being spaced apart from the first electrode along a second direction; At least one first protrusion is disposed at the first end of the first electrode, the at least one first protrusion extends along the first direction and does not completely cover the first end; A first dummy electrode, aligned with the first electrode along the first direction, and having a first dummy end, wherein a first gap is formed between the first dummy end and the first dummy end; and At least one first dummy protrusion is disposed at the first dummy end of the first dummy electrode, extends along the first direction and does not completely cover the first dummy end, wherein the at least one first protrusion and the at least one first dummy protrusion are spaced apart along the second direction.

2. The acoustic device as described in claim 1, characterized in that, in, The at least one first protrusion and the at least one first pseudo-protrusion are sequentially and alternately arranged along the second direction.

3. The acoustic device as described in claim 1, characterized in that, The transducer further includes: At least one second protrusion is disposed at the second end of the second electrode, the at least one second protrusion extending along the first direction and not completely covering the second end.

4. The acoustic device as described in claim 3, characterized in that, The transducer further includes: A second dummy electrode, aligned with the second electrode along the first direction, and having a second dummy end, wherein a second gap is formed between the second dummy end and the second dummy end; and At least one second pseudo-protrusion is disposed at the second pseudo-end of the second pseudo electrode, extends along the first direction and does not completely cover the second pseudo-end; The at least one second protrusion and the at least one second pseudo-protrusion are spaced apart along the second direction.

5. The acoustic device as described in claim 4, characterized in that, in The at least one first protrusion and the at least one first pseudo-protrusion are sequentially and alternately arranged along the second direction; and The at least one second protrusion and the at least one second pseudo-protrusion are sequentially and alternately arranged along the second direction.

6. The acoustic device as described in claim 4, characterized in that, in: The distance between the at least one first protrusion and the first pseudo-end in the first direction is at least 0.3 micrometers; and the distance between the at least one first protrusion and the at least one first pseudo-protrusion in the second direction is at least 0.3 micrometers.

7. The acoustic device as described in claim 4, characterized in that, in: The distance between the at least one second protrusion and the second pseudo-end in the first direction is at least 0.3 micrometers; and the distance between the at least one second protrusion and the at least one second pseudo-protrusion in the second direction is at least 0.3 micrometers.

8. The acoustic device as described in claim 4, characterized in that, in: The first electrode is integrally formed with the at least one first protrusion; The second electrode is integrally formed with the at least one second protrusion; The at least one first dummy protrusion is integrally formed with the first dummy electrode; or The at least one second pseudo-protrusion is integral with the second pseudo-electrode.

9. The acoustic device as described in claim 4, characterized in that, in: The dimension of the at least one first protrusion along the second direction is 5% to 50% of the dimension of the first electrode along the second direction; The dimension of the at least one second protrusion along the second direction is 5% to 50% of the dimension of the second electrode along the second direction; The dimension of the at least one first dummy protrusion along the second direction is 5% to 50% of the dimension of the first dummy electrode along the second direction; or The dimension of the at least one second dummy protrusion along the second direction is 5% to 50% of the dimension of the second dummy electrode along the second direction.

10. The acoustic device as claimed in claim 4, characterized in that, The at least one first protrusion, the at least one second protrusion, the at least one first pseudo-protrusion, and the at least one second pseudo-protrusion have at least one square profile, an arc profile, or a triangular profile.

11. The acoustic device as claimed in claim 1, characterized in that, The transducer further includes: A first busbar, extending along the second direction; and A second busbar extends along the second direction; The first electrode extends from the first busbar along the first direction to the first end; and The second electrode extends from the second busbar along the first direction to the second end.

12. The acoustic device as claimed in claim 1, characterized in that, The transducer further includes: At least one other first electrode; and At least one other second electrode; The first electrode and the at least one other first electrode are interdigitated with the second electrode and the at least one other second electrode along the second direction.

13. The acoustic device as claimed in claim 1, characterized in that, The second direction is perpendicular to the first direction.

14. The acoustic device as claimed in claim 1, characterized in that, The materials of the first electrode and the second electrode include metals, wherein the metals include any combination of molybdenum, copper, aluminum, gold, platinum and tungsten.

15. The acoustic device as claimed in claim 1, characterized in that, in: The dimension of the at least one first protrusion along the second direction is 5% to 50% of the dimension of the first electrode along the second direction.

16. The acoustic device as claimed in claim 3, characterized in that, in: The dimension of the at least one first protrusion along the second direction is 5% to 50% of the dimension of the first electrode along the second direction; and The dimension of the at least one second protrusion along the second direction is 5% to 50% of the dimension of the second electrode along the second direction.

17. A method for manufacturing an acoustic device, characterized in that, Include: A piezoelectric substrate is provided, the piezoelectric substrate having a surface; A conductive layer is formed on the surface; and The conductive layer is patterned using a mask to form a patterned conductive layer, wherein the step of forming the patterned conductive layer includes: A first electrode is formed along a first direction, the first electrode having a first end; At least one first protrusion is formed at the first end of the first electrode, the at least one first protrusion extending along the first direction and not completely covering the first end; A second electrode is formed along the first direction, the second electrode having a second end, wherein the second electrode and the first electrode are spaced apart along a second direction; A first dummy electrode is formed along the first direction, the first dummy electrode is aligned with the first electrode and has a first dummy end, wherein a first gap is formed between the first dummy end and the first dummy end. and At least one first pseudo protrusion is formed at the first pseudo end of the first pseudo electrode. The at least one first pseudo protrusion extends along the first direction and does not completely cover the first pseudo end. The at least one first protrusion and the at least one first pseudo protrusion are spaced apart along the second direction.

18. The method for manufacturing the acoustic device as described in claim 17, characterized in that, in: The mask includes: At least one masking attachment, in the step of forming the patterned conductive layer, the position of the at least one masking attachment of the mask corresponds to the position of the at least one first protrusion of the first electrode; The method also includes: Form a first solder pad; Form a second solder pad; A bridging layer is formed between the first solder pad and the second solder pad; A connection layer is formed on the first solder pad, the second solder pad, and the bridging layer; and A passivation layer is formed on the connection layer, the first solder pad, the second solder pad, the first electrode, the second electrode, and the at least one first protrusion.

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