WO2022135252A1 - Bulk acoustic resonator having temperature compensation layer, and filter and electronic device - Google Patents
Bulk acoustic resonator having temperature compensation layer, and filter and electronic device Download PDFInfo
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- WO2022135252A1 WO2022135252A1 PCT/CN2021/138642 CN2021138642W WO2022135252A1 WO 2022135252 A1 WO2022135252 A1 WO 2022135252A1 CN 2021138642 W CN2021138642 W CN 2021138642W WO 2022135252 A1 WO2022135252 A1 WO 2022135252A1
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- electrode
- temperature compensation
- layer
- protective layer
- resonator
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Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/05—Holders; Supports
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/25—Constructional features of resonators using surface acoustic waves
Definitions
- Embodiments of the present invention relate to the field of semiconductors, and in particular, to a bulk acoustic wave resonator, a filter having the resonator, and an electronic device.
- FBAR thin film bulk acoustic resonator
- the structural main body of the thin film bulk acoustic wave resonator is a "sandwich" structure composed of an electrode-piezoelectric film-electrode, that is, a piezoelectric material is sandwiched between two metal electrode layers.
- the FBAR uses the inverse piezoelectric effect to convert the input electrical signal into mechanical resonance, and then uses the piezoelectric effect to convert the mechanical resonance into an electrical signal output.
- the film bulk acoustic wave resonator mainly uses the longitudinal piezoelectric coefficient of the piezoelectric film to generate the piezoelectric effect, so its main working mode is the longitudinal wave mode in the thickness direction, that is, the sound wave of the bulk acoustic wave resonator is mainly in the film body of the resonator, and the main operating mode is the longitudinal wave mode in the thickness direction.
- the vibration direction is in the vertical direction.
- the lateral Lamb wave will leak out from the lateral direction of the piezoelectric film layer, resulting in acoustic loss, thus making the Q value of the resonator. decrease.
- the BAW resonator generally has a negative frequency temperature drift coefficient, and its frequency temperature drift coefficient is about -30ppm/°C.
- the piezoelectric material and electrode material of the BAW resonator have a negative frequency temperature drift coefficient, which means that these The stiffness of the material will decrease with the increase of temperature, and the decrease of stiffness will decrease the speed of sound.
- FIG. 1 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art.
- the resonator includes a substrate 1 , an acoustic mirror cavity 2 , a seed layer 3 , a bottom electrode 4 , a seed layer 5 , a temperature compensation layer 11 , a piezoelectric layer 8 , a top electrode 9 and a passivation layer 10 .
- the thickness L1 of the bottom electrode, the thickness L2 of the piezoelectric layer, and the thickness L3 of the top electrode are shown in FIG. 1 .
- the material SiO 2 of the temperature compensation layer 11 will be released under the action of HF, as shown in FIG. 2 .
- 2 is the SEM picture of the released thermal compensation layer in the existing design. The material release of the temperature compensation layer 11 causes fluctuations in the electromechanical coupling coefficient of the resonator and changes in the area of the 50 ⁇ resonator.
- FIG. 3 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art, wherein a bottom electrode interlayer 12 covers the temperature compensation layer 11 to prevent SiO from being released, but the resonator has a small electromechanical coupling coefficient of the resonator. , it will cause the electrode thickness L1 and L3, and the piezoelectric layer thickness L2 to be out of proportion, that is, (L1+L3)/L2 is much larger than 1, as shown in Figure 3, which will cause the performance of the resonator to degrade (see later of Figure 5).
- the present invention is proposed to alleviate or solve at least one aspect of the above-mentioned problems in the prior art.
- a bulk acoustic wave resonator comprising:
- a piezoelectric layer arranged between the bottom electrode and the top electrode
- the temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer, and the temperature compensation layer structure includes a temperature compensation layer,
- the resonator also includes a protective layer
- the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by exposed through an opening defined by the inner edge of the layer, the opening being at least partially within the active area of the resonator;
- the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or is located inside the non-electrode connection end of the top electrode.
- Embodiments of the present invention also relate to a method for manufacturing a bulk acoustic wave resonator, the resonator comprising a substrate, an acoustic mirror, a bottom electrode, a top electrode, a piezoelectric layer disposed between the bottom electrode and the top electrode, including a temperature compensation
- the temperature compensation layer structure of the layer, the temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer
- the method includes the steps:
- a temperature compensation layer structure is formed on the bottom electrode
- the protective layer is arranged such that:
- the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by And at the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or at the non-electrode connection end of the top electrode. inside.
- Embodiments of the present invention also relate to a filter comprising the above-mentioned bulk acoustic wave resonator.
- Embodiments of the present invention also relate to an electronic device comprising the above-mentioned filter or the above-mentioned resonator.
- FIG. 1 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art
- Fig. 2 is the SEM picture of the temperature compensation layer being released in the existing design
- FIG. 3 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art, wherein a CM layer is provided above the temperature compensation layer;
- FIG. 4 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention
- FIG. 5 exemplarily shows a performance comparison diagram of the resonator of the structure shown in FIG. 3 and the structure shown in FIG. 4;
- FIG. 6 exemplarily shows a schematic diagram of the relationship between the width of the protective layer on the upper surface of the temperature compensation layer and the performance of the resonator
- FIG. 9-11 illustrate schematic top views of bulk acoustic wave resonators according to different embodiments of the present invention.
- FIG. 12A-12F illustrate a series of schematic cross-sectional views of a method of fabricating the structure shown in FIG. 4 in accordance with an exemplary embodiment of the present invention.
- Substrate, optional materials are single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.
- Acoustic mirror which can be a cavity, or a Bragg reflector and other equivalent forms.
- a cavity provided on the upper surface of the substrate is used.
- the cavity may also be located inside the substrate.
- the first seed layer can be selected from materials such as aluminum nitride, zinc oxide, and PZT, and includes a rare earth element doped material with a certain atomic ratio of the above materials.
- Bottom electrode, material optional: gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), Titanium (Ti), Osmium (Os), Magnesium (Mg), Gold (Au), Tungsten (W), Molybdenum (Mo), Platinum (Pt), Ruthenium (Ru), Iridium (Ir), Germanium (Ge), Copper (Cu), aluminum (Al), chromium (Cr), arsenic doped gold and the like.
- the second seed layer can be selected from materials such as aluminum nitride, zinc oxide, and PZT, and contains a rare earth element doped material with a certain atomic ratio of the above materials.
- the third seed layer can be selected from materials such as aluminum nitride, zinc oxide, and PZT, and includes a rare earth element doped material with a certain atomic ratio of the above materials.
- Protective layer which can be a non-metallic material to prevent the temperature compensation layer from being etched or released, or a metal material.
- the metal material of the protective layer can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium , osmium, chromium or the composite of the above metals or their alloys, etc., the material of the metal protective layer can be the same as the electrode material.
- Piezoelectric layer which can be a single crystal piezoelectric material, optional, such as: single crystal aluminum nitride, single crystal gallium nitride, single crystal lithium niobate, single crystal lead zirconate titanate (PZT), single crystal Potassium niobate, single crystal quartz film, or single crystal lithium tantalate and other materials can also be polycrystalline piezoelectric materials (corresponding to single crystal, non-single crystal materials), optional, such as polycrystalline aluminum nitride, Zinc oxide, PZT, etc., can also be a rare earth element doped material containing a certain atomic ratio of the above materials, for example, can be doped aluminum nitride, and doped aluminum nitride contains at least one rare earth element, such as scandium (Sc), yttrium (Y), magnesium (Mg), titanium (Ti), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (
- Top electrode the material of which can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or their alloys.
- the top and bottom electrode materials are generally the same, but can also be different.
- Process layer which is arranged on the top electrode of the resonator.
- the role of the process layer can be a mass adjustment load or a passivation layer, and its material can be a dielectric material, such as silicon dioxide, aluminum nitride, silicon nitride, and the like.
- the material of the temperature compensation layer 11 is a material with a frequency temperature coefficient opposite to that of the piezoelectric layer, which can be polysilicon, borophosphate glass (BSG), silicon dioxide (SiO 2 ), doped silicon dioxide (such as fluorine doping), chromium (Cr) or tellurium oxide (TeO(x)) and other positive temperature coefficient materials.
- BSG borophosphate glass
- SiO 2 silicon dioxide
- doped silicon dioxide Such as fluorine doping
- Cr chromium
- TeO(x) tellurium oxide
- the stiffness of materials with a positive frequency temperature drift coefficient such as SiO 2 will increase as the temperature increases, so it is possible to compensate or reduce ordinary resonance by adding a layer of SiO 2 and other materials with a positive frequency temperature drift coefficient (ie, temperature compensation layer).
- the speed of sound decreases due to the decrease in stiffness of the temperature compensation layer (excluding the temperature compensation layer) as the temperature rises, so as to reduce the negative drift of the frequency with the increase of temperature, and then zero temperature drift or frequency temperature drift coefficient can be achieved by setting the appropriate thickness of the temperature compensation layer. within ⁇ 5ppm/°C.
- Interlayer electrode the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or their alloys.
- a protective layer structure is used to prevent the temperature compensation layer from being etched or released, and at the same time, on the premise of ensuring the performance of the resonator, zero temperature drift performance can be achieved.
- the protection structure for forming the temperature compensation layer is a protection ring structure (CP ring). As described later with reference to FIGS. 12A-12F, it can be formed by deposition and etching of the film layer, and the process flow has high feasibility .
- the deposition thickness of the film layer is controllable and the ⁇ angle of the etched CP ring is controllable, which will not cause fracture of the piezoelectric layer.
- the ⁇ angle is required to be less than 90°, and the range of the ⁇ angle is the same as the end of the bottom electrode.
- the degree of ⁇ is 90%-110% of the included angle of the end of the non-electrode connection end of the bottom electrode.
- the inner edge of the CP ring or the protective layer 7 is an inclined plane, and the angle between the inclined plane and the upper surface of the temperature compensation layer 11 is an acute angle ⁇ .
- the thickness of the protective layer 7 gradually increases in the direction from the inner side to the outer side.
- the protective layer 7 is in the form of a CP ring, in other words, at the non-electrode connection end of the top electrode, the protective layer 7 covers at least a portion of the temperature compensation layer structure along the circumferential direction of the temperature compensation layer structure.
- the upper surface, a portion of the upper surface of the thermo-compensating layer structure, is exposed through an opening defined by the inner edge of the protective layer 7, the opening being at least partially within the effective area of the resonator.
- the "opening" here corresponds to the "ring" in the CP ring.
- the CP ring or opening may or may not be closed. As can be understood and shown in FIGS.
- the temperature compensation layer structure includes the temperature compensation layer 11 and the seed layer 6 , and the temperature compensation layer 11 is provided with the seed layer 6 .
- the temperature compensation layer structure includes the temperature compensation layer 11 .
- the inner edge of the protective layer 7 is on the inner side of the non-electrode connection end of the top electrode 9 in the horizontal direction. As can be understood, the inner edge of the protective layer 7 may also be flush with the non-electrode connection end of the top electrode 9 in the horizontal direction.
- the upper side of the temperature compensation layer 11 is also covered with the third seed layer 6 .
- the protective layer 7 is actually the third seed layer 6 covering the temperature compensation layer.
- the protective layer 7 covers the upper surface of the third seed layer 6 along at least a part of the circumferential direction of the temperature compensation layer 11 , and a part of the upper surface of the third seed layer 6 passes through the protective layer 7 The opening defined by the inner edge is exposed.
- the third seed layer 6 may not be provided on the temperature compensation layer 11 .
- the protective layer 7 covers the upper surface of the temperature compensation layer 11 itself along at least a part of the circumferential direction of the temperature compensation layer 11 , and a part of the upper surface of the temperature compensation layer is exposed through the opening defined by the inner edge of the protection layer 7 .
- the difference from the manufacturing process of the structure shown in FIG. 4 is that after the temperature compensation layer 11 is formed, the third seed layer 6 is not deposited, and the protective layer material is deposited directly through the A liftoff process forms the protective layer 7 or the CP ring structure to protect the temperature compensation layer 11 from being released in subsequent steps.
- the upper surface of the exposed portion of the temperature compensation layer 11 shown in FIG. 7 is flat top surface.
- the difference from the manufacturing process of the structure shown in FIG. 7 is that after the temperature compensation layer 11 is formed, the third seed layer 6 is not deposited, and the protective layer material is deposited by etching The process forms the protective layer 7 or the CP ring structure to protect the temperature compensation layer 11 from being released in subsequent steps.
- the temperature compensation layer 11 is also over-etched, so that the exposed part of the upper surface of the temperature compensation layer 11 is in a concave shape, that is, the upper surface of the temperature compensation layer has an opening through the opening. The exposed portion is recessed with respect to other portions of the upper surface of the warm compensation layer.
- the protective layer 7 covers at least a portion of the electrode connection end and at least a portion of the non-electrode connection end of the bottom electrode 4 .
- the protective layer 7 may cover at least a portion of the electrode connection end of the bottom electrode 4 or at least a portion of the non-electrode connection end.
- the protective layer 7 covers the bottom electrode 4 and the outer edge of the protective layer 7 is on the surface of the bottom electrode. Non-electrode connection end faces are flush.
- FIGS. 9-11 illustrate schematic top views of bulk acoustic wave resonators according to various embodiments of the present invention.
- the protective layer 7 or the CP ring structure is only provided along the circumference of the non-electrode connection end of the top electrode, but not provided at the electrode connection end of the top electrode. As can be understood, the protective layer 7 or the CP ring structure may also be provided only along a part of the circumference of the non-electrode connection end of the top electrode.
- the protective layer 7 or the CP ring structure is not only provided at the non-electrode connection end of the top electrode along the circumferential direction, but also provided at the electrode connection end of the top electrode.
- the protective layer 7 or the CP ring structure is not only provided at the non-electrode connection end of the top electrode along the circumferential direction, but also at the electrode connection end of the top electrode.
- FIG. 6 exemplarily shows a schematic diagram of the relationship between the width of the protective layer on the upper surface of the temperature compensation layer and the performance of the resonator. It can be seen that the width W1 of the protective layer 7 on the upper surface of the temperature compensation layer (see FIG. 4 ) has a great influence on the performance of the resonator. As shown in Fig. 6, when W1 is 0 or 2 ⁇ m, the value of the parallel resonance impedance Rp of the resonator is larger, which is 550 ohms, while when W1 is 7 ⁇ m, the value of the parallel resonance impedance Rp of the resonator is smaller, which is 450 ohms.
- the inner edge of the protective layer 7 is located inside the non-electrode connection end of the top electrode 9 in the horizontal direction and the distance between the two is W1 is less than 7 ⁇ m, and in a further embodiment, the distance W1 between the two is not less than 0 and less than 3 ⁇ m.
- the size of the CP ring or the protective layer at the electrode connection end of the resonator is not required.
- the size limit of the CP ring or the protective layer at the electrode connecting end of the resonator may be the same as that of the non-electrode connecting end, which are all within the protection scope of the present invention, and will not be repeated here.
- FIGS. 12A-12F illustrate a series of schematic cross-sectional views of a method of fabricating the structure shown in FIG. 4 in accordance with an exemplary embodiment of the present invention.
- Step 1 As shown in FIG. 12A, a substrate 1 is provided, a cavity is formed on the substrate 1 by an etching method, a sacrificial material is deposited on the substrate 1, the sacrificial material fills the cavity, and then, a CMP process is used to make the cavity. The surface of the sacrificial material layer in the cavity is flush with the upper surface of the substrate 1 . As mentioned later, the sacrificial material layer is released to form the acoustic mirror cavity 2 .
- Step 2 Deposit a first seed film layer and a conductive film layer in sequence on the structure shown in FIG. 12A, and pattern the two film layers by an etching process to form a first seed layer 3 and a bottom electrode 4, as shown in FIG. 12B. Show.
- Step 3 Deposit a second seed material layer, which may be aluminum nitride, on the structure of FIG. 12B.
- a layer of temperature compensation material such as silicon dioxide, is deposited on the second seed material layer.
- the temperature compensation material layer is patterned to form the temperature compensation layer 11 .
- the second seed layer 5 serves as an etch stop layer for protecting the bottom electrode 4 .
- the second seed material layer is etched to form the second seed layer 5 .
- a third seed material layer which may be aluminum nitride, is deposited, etched and patterned to form the third seed layer 6 .
- the third seed layer 6 is used to protect the temperature compensation layer 11 as a barrier layer when the protective layer or the CP ring is etched in a subsequent step.
- seed layers are arranged on both the upper and lower sides of the silicon dioxide temperature compensation layer, it is beneficial to increase the adhesion between the film layers, and the film layer structure is more stable.
- Step 4 As shown in FIG. 12D , deposit a protective material layer on the structure shown in FIG. 12C , and then etch the protective material layer to form a protective layer 7 .
- the inner side of the protective layer 7 defines an opening.
- the protective layer 7 covers the upper surface of the temperature compensation layer structure along at least a part of the circumferential direction of the temperature compensation layer structure, and the upper surface of the temperature compensation layer structure A portion is exposed through an opening defined by the inner edge of the protective layer.
- the position of the inner edge of the protective layer 7 needs to be set so as to connect with the non-electrode of the top electrode prepared in the subsequent step in the horizontal direction.
- the end is flush or inside the non-electrode connection end of the top electrode.
- Step 5 As shown in FIG. 12E, a piezoelectric layer 8 is deposited on the structure of FIG. 12D.
- Step 6 As shown in FIG. 12F , the top electrode 9 and the process layer 10 are prepared on the structure of FIG. 12E , thereby forming the structure of FIG. 4 .
- the CP ring or protective layer 7 is mainly to prevent the temperature compensation layer 11 from being released or etched by an etchant such as HF solution.
- the outside of the CP ring or protective layer 7 is horizontally outside the boundary of the cavity of the acoustic mirror.
- the outer side of the CP ring or the protective layer 7 may also be in the inner side of the boundary of the acoustic mirror cavity in the horizontal direction.
- the outer side of the CP ring or the protective layer 7 may also be horizontally level with the non-electrode connection end of the top electrode.
- the structure proposed by the invention can also be suitable for narrow-band product requirements, and can meet the performance requirements on the premise of ensuring the electromechanical coupling coefficient.
- the electromechanical coupling coefficient changes with the increase of the release time, but the electromechanical coupling coefficient of the resonator with the protective layer structure according to the present invention is stable and does not change with the increase of the release time. varies with release time.
- the performance of the resonator (parallel resonance impedance Rp of the resonator) based on the structure of the present invention is significantly improved, as shown in FIG. 5 . .
- the parallel resonance impedance Rp of the resonator is 170 ohms;
- the parallel resonance impedance Rp of the resonator is 550 ohms.
- the electromechanical coupling coefficient of the bulk acoustic wave resonator using the protective layer structure of the present invention is not greater than 3%.
- each numerical range except that it is clearly indicated that it does not include the endpoint value, can be the endpoint value, and can also be the median value of each numerical range, and these are all within the protection scope of the present invention. .
- upper and lower are relative to the bottom surface of the base of the resonator.
- the side close to the bottom surface is the lower side, and the side away from the bottom surface is the upper side.
- the inner and outer are relative to the center of the effective area of the resonator in the lateral direction or the radial direction
- the side or one end of a component close to the center is the inner or inner end
- the component The side or end away from the center is the outer or outer end.
- BAW resonators may be used to form filters or other semiconductor devices.
- a bulk acoustic wave resonator comprising:
- a piezoelectric layer arranged between the bottom electrode and the top electrode
- the temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer, and the temperature compensation layer structure includes a temperature compensation layer,
- the resonator also includes a protective layer
- the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by exposed through an opening defined by the inner edge of the layer, the opening being at least partially within the active area of the resonator;
- the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or is located inside the non-electrode connection end of the top electrode.
- the protective layer covers an upper surface of the warm compensation layer along at least a part of the circumferential direction of the warm compensation layer, and a part of the upper surface of the warm compensation layer is exposed through an opening defined by an inner edge of the protective layer.
- the upper surface of the temperature compensation layer is a flat upper surface.
- the portion of the upper surface of the temperature compensation layer exposed through the opening is recessed relative to other portions of the upper surface of the temperature compensation layer.
- the temperature compensation layer structure includes a temperature compensation layer and a seed layer covering the temperature compensation layer on the upper side of the temperature compensation layer;
- the protective layer covers an upper surface of the seed layer along at least a portion of the temperature compensation layer structure in the circumferential direction, and a portion of the upper surface of the seed layer is exposed through an opening defined by an inner edge of the protective layer.
- the protective layer covers at least a part of the electrode connection end and/or at least a part of the non-electrode connection end of the bottom electrode.
- the protective layer covers the bottom electrode and the surface where the outer edge of the protective layer is located is flush with the non-electrode connecting end surface of the bottom electrode.
- the inner edge of the protective layer is an inclined plane, and the angle between the inclined plane and the upper surface of the temperature compensation layer structure covered by the protective layer is an acute angle. Based on the inclined plane, at the inner edge of the protective layer, the protective layer The thickness gradually increases from the inside to the outside.
- the included angle is 90%-110% of the included angle of the end of the non-electrode connecting end of the bottom electrode.
- the inner edge of the protective layer is located inside the non-electrode connection end of the top electrode in the horizontal direction, and the distance therebetween is less than 7 ⁇ m.
- the inner edge of the protective layer is located inside the non-electrode connection end of the top electrode in the horizontal direction, and the distance therebetween is less than 3 ⁇ m.
- the protective layer is a metal protective layer.
- the protective layer is a metal protective layer
- the protective layer is electrically connected to the bottom electrode.
- the protective layer is disposed along at least the entire non-electrode connection end of the top electrode.
- the protective layer is only provided along the non-electrode connection end of the top electrode.
- the protective layer is disposed along the entire non-electrode connection end of the top electrode and part of the electrode connection end of the top electrode.
- the protective layer is a ring-shaped protective layer arranged along the entire non-electrode connection end of the top electrode and the entire electrode connection end of the top electrode.
- the electromechanical coupling coefficient of the resonator is not more than 3%.
- a method for manufacturing a bulk acoustic wave resonator comprising a substrate, an acoustic mirror, a bottom electrode, a top electrode, a piezoelectric layer arranged between the bottom electrode and the top electrode, a temperature compensation layer comprising a temperature compensation layer structure, the temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer,
- the method includes the steps:
- a temperature compensation layer structure is formed on the bottom electrode
- the protective layer is arranged such that:
- the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by And at the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or at the non-electrode connection end of the top electrode. inside.
- the protective layer is arranged only along the non-electrode connection end of the top electrode; or, along the entire non-electrode connection end of the top electrode and part of the electrode connection end of the top electrode; or, along the entire non-electrode connection end of the top electrode.
- the electrode connection end and the entire electrode connection end of the top electrode are provided.
- the step of disposing the protective layer includes: disposing a protective material layer covering the entire upper surface of the temperature compensation layer structure; removing a part of the protective material layer on the upper surface of the temperature compensation layer structure to form the protective layer, The portion of the upper surface of the temperature compensation layer structure is at least partially within the effective area of the resonator.
- a part of the upper surface of the thermal compensation layer structure of the protective material layer is removed by a lift-off process.
- the inner edge of the finally formed protective layer is horizontally positioned at the non-electrode connection end of the top electrode inside and the distance between them is less than 7 ⁇ m.
- the protective layer is a metal protective layer
- the protective layer is electrically connected to the bottom electrode.
- a filter comprising the bulk acoustic wave resonator of any of 1-18.
- An electronic device comprising the filter according to 25, or the bulk acoustic wave resonator according to any one of 1-18.
- the electronic equipment here includes but is not limited to intermediate products such as RF front-end, filter and amplifier modules, and terminal products such as mobile phones, WIFI, and drones.
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Abstract
The present invention relates to a bulk acoustic resonator and a manufacturing method therefor. The resonator comprises: a substrate, an acoustic mirror, a bottom electrode, a top electrode, a piezoelectric layer, which is arranged between the bottom electrode and the top electrode, and a temperature compensation layer structure, which is arranged between the bottom electrode and the piezoelectric layer, wherein the temperature compensation layer structure comprises a temperature compensation layer. The resonator further comprises a protection layer, wherein at a non-electrode-connection end of the top electrode, the protection layer covers an upper surface of the temperature compensation layer structure along at least a part of the temperature compensation layer structure in a circumferential direction, a part of the upper surface of the temperature compensation layer structure is exposed from an opening defined by an inner edge of the protection layer, and the opening is at least partially located in an effective area of the resonator; and at the non-electrode-connection end of the top electrode, the inner edge of the protection layer is flush with the non-electrode-connection end of the top electrode in a horizontal direction, or is located on an inner side of the non-electrode-connection end of the top electrode. The present invention further relates to a filter and an electronic device.
Description
本发明的实施例涉及半导体领域,尤其涉及一种体声波谐振器,一种具有该谐振器的滤波器,以及一种电子设备。Embodiments of the present invention relate to the field of semiconductors, and in particular, to a bulk acoustic wave resonator, a filter having the resonator, and an electronic device.
随着5G通信技术的日益发展,对通信频段的要求越来越高。传统的射频滤波器受结构和性能的限制,不能满足高频通信的要求。薄膜体声波谐振器(FBAR)作为一种新型的MEMS器件,具有体积小、质量轻、插入损耗低、频带宽以及品质因子高等优点,很好地适应了无线通信系统的更新换代,使FBAR技术成为通信领域的研究热点之一。With the increasing development of 5G communication technology, the requirements for communication frequency bands are getting higher and higher. Traditional RF filters are limited by structure and performance and cannot meet the requirements of high-frequency communication. As a new type of MEMS device, thin film bulk acoustic resonator (FBAR) has the advantages of small size, light weight, low insertion loss, high frequency bandwidth and high quality factor. It has become one of the research hotspots in the field of communication.
薄膜体声波谐振器的结构主体为由电极-压电薄膜-电极组成的“三明治”结构,即两层金属电极层之间夹一层压电材料。通过在两电极间输入正弦信号,FBAR利用逆压电效应将输入电信号转换为机械谐振,并且再利用压电效应将机械谐振转换为电信号输出。薄膜体声波谐振器主要利用压电薄膜的纵向压电系数产生压电效应,所以其主要工作模式为厚度方向上的纵波模式,即体声波谐振器的声波主要在谐振器的薄膜体内,而且主要的震动方向在纵向。但是由于存在边界,在边界处会存在不垂直于压电膜层的兰姆波,这时横向的兰姆波会从压电膜层的横向漏出,导致声学损失,从而使得谐振器的Q值减小。The structural main body of the thin film bulk acoustic wave resonator is a "sandwich" structure composed of an electrode-piezoelectric film-electrode, that is, a piezoelectric material is sandwiched between two metal electrode layers. By inputting a sinusoidal signal between two electrodes, the FBAR uses the inverse piezoelectric effect to convert the input electrical signal into mechanical resonance, and then uses the piezoelectric effect to convert the mechanical resonance into an electrical signal output. The film bulk acoustic wave resonator mainly uses the longitudinal piezoelectric coefficient of the piezoelectric film to generate the piezoelectric effect, so its main working mode is the longitudinal wave mode in the thickness direction, that is, the sound wave of the bulk acoustic wave resonator is mainly in the film body of the resonator, and the main operating mode is the longitudinal wave mode in the thickness direction. The vibration direction is in the vertical direction. However, due to the existence of a boundary, there will be Lamb waves that are not perpendicular to the piezoelectric film layer at the boundary. At this time, the lateral Lamb wave will leak out from the lateral direction of the piezoelectric film layer, resulting in acoustic loss, thus making the Q value of the resonator. decrease.
此外,体声波谐振器一般具有负频率温漂系数,其频率温漂系数大概是-30ppm/℃,其原因在于体声波谐振器的压电材料和电极材料是负频率温漂系数,这表示这些材料的刚度会随着温度的升高而减小,刚度降低会使声速下降。基于公式V=F*λ=F*2d(其中V为声速,F为频率,λ为波长,d为对应叠层厚度),随着声速下降,频率会降低,因此,体声波谐振器存在着随着温度升高而频率漂移的现象。但当温度升高,SiO
2以及正温度系数材料的刚度会提高,所以通过增加SiO
2以及正温度系数材料层,来实现抵消其他材料刚度下降导致声速下降,从而防止频率漂移。
In addition, the BAW resonator generally has a negative frequency temperature drift coefficient, and its frequency temperature drift coefficient is about -30ppm/℃. The reason is that the piezoelectric material and electrode material of the BAW resonator have a negative frequency temperature drift coefficient, which means that these The stiffness of the material will decrease with the increase of temperature, and the decrease of stiffness will decrease the speed of sound. Based on the formula V=F*λ=F*2d (where V is the speed of sound, F is the frequency, λ is the wavelength, and d is the thickness of the corresponding stack), as the speed of sound decreases, the frequency will decrease. Therefore, BAW resonators exist The phenomenon of frequency drift with increasing temperature. However, when the temperature increases, the stiffness of SiO 2 and PTC materials will increase, so by adding layers of SiO 2 and PTC materials, it can offset the decrease in the stiffness of other materials and cause the decrease in sound speed, thereby preventing frequency drift.
图1为现有技术中体声波谐振器的截面示意图。如图1所示,谐振器包括基底1,声学镜空腔2,种子层3,底电极4,种子层5,温补层11,压电 层8,顶电极9以及钝化层10。图1中示出了底电极的厚度L1,压电层的厚度L2,顶电极的厚度L3。FIG. 1 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art. As shown in FIG. 1 , the resonator includes a substrate 1 , an acoustic mirror cavity 2 , a seed layer 3 , a bottom electrode 4 , a seed layer 5 , a temperature compensation layer 11 , a piezoelectric layer 8 , a top electrode 9 and a passivation layer 10 . The thickness L1 of the bottom electrode, the thickness L2 of the piezoelectric layer, and the thickness L3 of the top electrode are shown in FIG. 1 .
在如图1所示的设置温补层11的通常的体声波谐振器中,由于没有保护层,温补层11的材料SiO
2在HF的作用下会被释放,如图2所示,图2为现有设计中温补层被释放的SEM图片。温补层11的材料释放会造成谐振器的机电耦合系数的波动以及50Ω谐振器的面积改变。
In the conventional bulk acoustic wave resonator provided with the temperature compensation layer 11 as shown in FIG. 1 , since there is no protective layer, the material SiO 2 of the temperature compensation layer 11 will be released under the action of HF, as shown in FIG. 2 . 2 is the SEM picture of the released thermal compensation layer in the existing design. The material release of the temperature compensation layer 11 causes fluctuations in the electromechanical coupling coefficient of the resonator and changes in the area of the 50Ω resonator.
为了防止或减少温补层被释放,提出了一种如图3所示的结构。图3为现有技术中体声波谐振器的截面示意图,其中,一层底电极夹层12覆盖温补层11来防止SiO
2被释放,但是在谐振器有小的谐振器的机电耦合系数的需求时,会造成电极厚度L1和L3,和压电层厚度L2比例失调,即(L1+L3)/L2远大于1,如图3所示,这会导致谐振器的性能下降(参见后面提及的图5)。
In order to prevent or reduce the release of the temperature compensation layer, a structure as shown in FIG. 3 is proposed. 3 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art, wherein a bottom electrode interlayer 12 covers the temperature compensation layer 11 to prevent SiO from being released, but the resonator has a small electromechanical coupling coefficient of the resonator. , it will cause the electrode thickness L1 and L3, and the piezoelectric layer thickness L2 to be out of proportion, that is, (L1+L3)/L2 is much larger than 1, as shown in Figure 3, which will cause the performance of the resonator to degrade (see later of Figure 5).
发明内容SUMMARY OF THE INVENTION
为缓解或解决现有技术中的上述问题的至少一个方面,提出本发明。The present invention is proposed to alleviate or solve at least one aspect of the above-mentioned problems in the prior art.
根据本发明的实施例的一个方面,提出了一种体声波谐振器,包括:According to an aspect of the embodiments of the present invention, a bulk acoustic wave resonator is proposed, comprising:
基底;base;
声学镜;acoustic mirror;
底电极;bottom electrode;
顶电极;top electrode;
压电层,设置在底电极与顶电极之间;a piezoelectric layer, arranged between the bottom electrode and the top electrode;
温补层结构,设置在底电极与压电层之间,温补层结构包括温补层,The temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer, and the temperature compensation layer structure includes a temperature compensation layer,
其中:in:
所述谐振器还包括保护层;The resonator also includes a protective layer;
在顶电极的非电极连接端,所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述温补层结构的上表面,所述温补层结构的上表面的一部分经由保护层的内缘限定的开口而露出,所述开口至少部分处于谐振器的有效区域内;且At the non-electrode connection end of the top electrode, the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by exposed through an opening defined by the inner edge of the layer, the opening being at least partially within the active area of the resonator; and
在顶电极的非电极连接端,所述保护层的内缘在水平方向上与顶电极的非电极连接端齐平或者处于顶电极的非电极连接端的内侧。At the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or is located inside the non-electrode connection end of the top electrode.
本发明的实施例也涉及一种体声波谐振器的制造方法,所述谐振器包括 基底、声学镜、底电极、顶电极、设置在底电极与顶电极之间的压电层、包括温补层的温补层结构,所述温补层结构设置在底电极与压电层之间,Embodiments of the present invention also relate to a method for manufacturing a bulk acoustic wave resonator, the resonator comprising a substrate, an acoustic mirror, a bottom electrode, a top electrode, a piezoelectric layer disposed between the bottom electrode and the top electrode, including a temperature compensation The temperature compensation layer structure of the layer, the temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer,
所述方法包括步骤:The method includes the steps:
在底电极上形成温补层结构;A temperature compensation layer structure is formed on the bottom electrode;
在形成温补层结构之后,设置保护层,使得:After the temperature compensation layer structure is formed, the protective layer is arranged such that:
在顶电极的非电极连接端,所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述温补层结构的上表面,所述温补层结构的上表面的一部分经由保护层的内缘限定的开口而露出;以及在顶电极的非电极连接端,所述保护层的内缘在水平方向上与顶电极的非电极连接端齐平或者处于顶电极的非电极连接端的内侧。At the non-electrode connection end of the top electrode, the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by And at the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or at the non-electrode connection end of the top electrode. inside.
本发明的实施例还涉及一种滤波器,包括上述的体声波谐振器。Embodiments of the present invention also relate to a filter comprising the above-mentioned bulk acoustic wave resonator.
本发明的实施例也涉及一种电子设备,包括上述的滤波器或者上述的谐振器。Embodiments of the present invention also relate to an electronic device comprising the above-mentioned filter or the above-mentioned resonator.
以下描述与附图可以更好地帮助理解本发明所公布的各种实施例中的这些和其他特点、优点,图中相同的附图标记始终表示相同的部件,其中:These and other features and advantages of the various disclosed embodiments of the present invention may be better understood by the following description and accompanying drawings, in which like reference numerals refer to like parts throughout, wherein:
图1为现有技术中体声波谐振器的截面示意图;1 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art;
图2为现有设计中温补层被释放的SEM图片;Fig. 2 is the SEM picture of the temperature compensation layer being released in the existing design;
图3为现有技术中体声波谐振器的截面示意图,其中温补层上方设置有CM层;3 is a schematic cross-sectional view of a bulk acoustic wave resonator in the prior art, wherein a CM layer is provided above the temperature compensation layer;
图4为根据本发明的一个示例性实施例的体声波谐振器的截面示意图;4 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention;
图5示例性示出了图3所示结构与图4所示结构的谐振器的性能比较图;FIG. 5 exemplarily shows a performance comparison diagram of the resonator of the structure shown in FIG. 3 and the structure shown in FIG. 4;
图6示例性示出了保护层在温补层的上表面上的宽度与谐振器的性能之间的关系示意图;FIG. 6 exemplarily shows a schematic diagram of the relationship between the width of the protective layer on the upper surface of the temperature compensation layer and the performance of the resonator;
图7-8示例性示出了根据本发明的不同实施例的体声波谐振器的截面示意图;7-8 illustrate schematic cross-sectional views of bulk acoustic wave resonators according to various embodiments of the present invention;
图9-11示例性示出了根据本发明的不同实施例的体声波谐振器的俯视示意图;9-11 illustrate schematic top views of bulk acoustic wave resonators according to different embodiments of the present invention;
图12A-12F示例性示出了根据本发明的一个示例性实施例的制造图4所示的结构的方法的一系列截面示意图。12A-12F illustrate a series of schematic cross-sectional views of a method of fabricating the structure shown in FIG. 4 in accordance with an exemplary embodiment of the present invention.
下面通过实施例,并结合附图,对本发明的技术方案作进一步具体的说明。在说明书中,相同或相似的附图标号指示相同或相似的部件。下述参照附图对本发明实施方式的说明旨在对本发明的总体发明构思进行解释,而不应当理解为对本发明的一种限制。发明的一部分实施例,而并不是全部的实施例。基于本发明中的实施例,本领域普通技术人员所获得的所有其他实施例,都属于本发明保护的范围。The technical solutions of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals refer to the same or similar parts. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention, and should not be construed as a limitation of the present invention. Some, but not all, embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the protection scope of the present invention.
首先,本发明的附图中的附图标记说明如下:First of all, the reference numerals in the accompanying drawings of the present invention are explained as follows:
1:基底,可选材料为单晶硅、氮化镓、砷化镓、蓝宝石、石英、碳化硅、金刚石等。1: Substrate, optional materials are single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.
2:声学镜,可为空腔,也可采用布拉格反射层及其他等效形式。本发明所示的实施例中采用的是设置于基底的上表面的空腔,在可选的实施例中,空腔也可以位于基底的内部。2: Acoustic mirror, which can be a cavity, or a Bragg reflector and other equivalent forms. In the embodiment shown in the present invention, a cavity provided on the upper surface of the substrate is used. In an optional embodiment, the cavity may also be located inside the substrate.
3:第一种子层,可选氮化铝,氧化锌,PZT等材料并包含上述材料的一定原子比的稀土元素掺杂材料。3: The first seed layer can be selected from materials such as aluminum nitride, zinc oxide, and PZT, and includes a rare earth element doped material with a certain atomic ratio of the above materials.
4:底电极,材料可选:金(Au)、钨(W)、钼(Mo)、铂(Pt),钌(Ru)、铱(Ir)、钛钨(TiW)、铝(Al)、钛(Ti)、锇(Os)、镁(Mg)、金(Au)、钨(W)、钼(Mo)、铂(Pt)、钌(Ru)、铱(Ir)、锗(Ge)、铜(Cu)、铝(Al)、铬(Cr)、砷掺杂金等类似金属。4: Bottom electrode, material optional: gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), Titanium (Ti), Osmium (Os), Magnesium (Mg), Gold (Au), Tungsten (W), Molybdenum (Mo), Platinum (Pt), Ruthenium (Ru), Iridium (Ir), Germanium (Ge), Copper (Cu), aluminum (Al), chromium (Cr), arsenic doped gold and the like.
5:第二种子层,可选氮化铝,氧化锌,PZT等材料并包含上述材料的一定原子比的稀土元素掺杂材料。5: The second seed layer can be selected from materials such as aluminum nitride, zinc oxide, and PZT, and contains a rare earth element doped material with a certain atomic ratio of the above materials.
6:第三种子层,可选氮化铝,氧化锌,PZT等材料并包含上述材料的一定原子比的稀土元素掺杂材料。6: The third seed layer can be selected from materials such as aluminum nitride, zinc oxide, and PZT, and includes a rare earth element doped material with a certain atomic ratio of the above materials.
7:保护层,可以是防止温补层被刻蚀或释放的非金属材料,也可以金属材料,保护层的金属材料可选钼、钌、金、铝、镁、钨、铜,钛、铱、锇、铬或以上金属的复合或其合金等,金属保护层的材料可以与电极材料相同。7: Protective layer, which can be a non-metallic material to prevent the temperature compensation layer from being etched or released, or a metal material. The metal material of the protective layer can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium , osmium, chromium or the composite of the above metals or their alloys, etc., the material of the metal protective layer can be the same as the electrode material.
8:压电层,可以为单晶压电材料,可选的,如:单晶氮化铝、单晶氮化镓、单晶铌酸锂、单晶锆钛酸铅(PZT)、单晶铌酸钾、单晶石英薄膜、或者单晶钽酸锂等材料,也可以为多晶压电材料(与单晶相对应,非单晶材料),可选的,如多晶氮化铝、氧化锌、PZT等,还可是包含上述材料的一定原子 比的稀土元素掺杂材料,例如可以是掺杂氮化铝,掺杂氮化铝至少含一种稀土元素,如钪(Sc)、钇(Y)、镁(Mg)、钛(Ti)、镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钷(Pm)、钐(Sm)、铕(Eu)、钆(Gd)、铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)等。8: Piezoelectric layer, which can be a single crystal piezoelectric material, optional, such as: single crystal aluminum nitride, single crystal gallium nitride, single crystal lithium niobate, single crystal lead zirconate titanate (PZT), single crystal Potassium niobate, single crystal quartz film, or single crystal lithium tantalate and other materials can also be polycrystalline piezoelectric materials (corresponding to single crystal, non-single crystal materials), optional, such as polycrystalline aluminum nitride, Zinc oxide, PZT, etc., can also be a rare earth element doped material containing a certain atomic ratio of the above materials, for example, can be doped aluminum nitride, and doped aluminum nitride contains at least one rare earth element, such as scandium (Sc), yttrium (Y), magnesium (Mg), titanium (Ti), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and the like.
9:顶电极,其材料可选钼、钌、金、铝、镁、钨、铜,钛、铱、锇、铬或以上金属的复合或其合金等。顶电极和底电极材料一般相同,但也可以不同。9: Top electrode, the material of which can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or their alloys. The top and bottom electrode materials are generally the same, but can also be different.
10:工艺层,设置在谐振器的顶电极上,工艺层的作用可以是质量调节负载或钝化层,其材料可以为介质材料,如二氧化硅、氮化铝、氮化硅等。10: Process layer, which is arranged on the top electrode of the resonator. The role of the process layer can be a mass adjustment load or a passivation layer, and its material can be a dielectric material, such as silicon dioxide, aluminum nitride, silicon nitride, and the like.
11:温补层,温补层11的材料是与压电层频率温度系数相反的材料,可以为多晶硅、硼磷酸盐玻璃(BSG)、二氧化硅(SiO
2)、掺杂二氧化硅(如氟掺杂)、铬(Cr)或碲氧化物(TeO(x))等正温度系数材料。例如,SiO
2等具有正频率温漂系数材料的刚度会随温度升高而提高,所以可以通过增加SiO
2等具有正频率温漂系数材料层(即温补层),来补偿或减少普通谐振器(不含温补层)随温度上升刚度下降导致的声速下降,从而减少频率随温度升高而产生的负漂移,进而可以通过设置合适的温补层厚度实现零温漂或频率温漂系数在±5ppm/℃范围内。
11: Temperature compensation layer, the material of the temperature compensation layer 11 is a material with a frequency temperature coefficient opposite to that of the piezoelectric layer, which can be polysilicon, borophosphate glass (BSG), silicon dioxide (SiO 2 ), doped silicon dioxide ( Such as fluorine doping), chromium (Cr) or tellurium oxide (TeO(x)) and other positive temperature coefficient materials. For example, the stiffness of materials with a positive frequency temperature drift coefficient such as SiO 2 will increase as the temperature increases, so it is possible to compensate or reduce ordinary resonance by adding a layer of SiO 2 and other materials with a positive frequency temperature drift coefficient (ie, temperature compensation layer). The speed of sound decreases due to the decrease in stiffness of the temperature compensation layer (excluding the temperature compensation layer) as the temperature rises, so as to reduce the negative drift of the frequency with the increase of temperature, and then zero temperature drift or frequency temperature drift coefficient can be achieved by setting the appropriate thickness of the temperature compensation layer. within ±5ppm/°C.
12:夹层电极,材料可选钼、钌、金、铝、镁、钨、铜,钛、铱、锇、铬或以上金属的复合或其合金等。12: Interlayer electrode, the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or their alloys.
在本发明中,使用了保护层结构来防止温补层被刻蚀或释放,同时,在保证谐振器性能的前提下,可实现零温漂性能。下面参照具体实施例示例性说明。In the present invention, a protective layer structure is used to prevent the temperature compensation layer from being etched or released, and at the same time, on the premise of ensuring the performance of the resonator, zero temperature drift performance can be achieved. The following descriptions are exemplified with reference to specific embodiments.
图4为根据本发明的一个示例性实施例的体声波谐振器的截面示意图。图4中,形成温补层的保护结构为保护环结构(CP环),如后面参照图12A-12F所述,其可通过膜层的沉积和刻蚀形成,工艺流程具有很高的可行性。膜层沉积厚度可控并且刻蚀后的CP环的θ角度可控,不会造成压电层的断裂,在本实施例中,θ角度要求小于90°,θ角度的范围与底电极的端部的角度接近,例如,θ的度数为底电极的非电极连接端的端部的夹角度数的90%-110%。更具体的,CP环或保护层7的内缘为斜面,所述斜面与温补层11的上表面之间的夹角为锐角θ,基于所述斜面,如图4所示,在保护层7的内缘,保护层7的厚度在从内侧到外侧的方向上逐渐变大。以上对于角度的 说明也可以适用于本发明的其他实施例。4 is a schematic cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention. In FIG. 4, the protection structure for forming the temperature compensation layer is a protection ring structure (CP ring). As described later with reference to FIGS. 12A-12F, it can be formed by deposition and etching of the film layer, and the process flow has high feasibility . The deposition thickness of the film layer is controllable and the θ angle of the etched CP ring is controllable, which will not cause fracture of the piezoelectric layer. In this embodiment, the θ angle is required to be less than 90°, and the range of the θ angle is the same as the end of the bottom electrode. For example, the degree of θ is 90%-110% of the included angle of the end of the non-electrode connection end of the bottom electrode. More specifically, the inner edge of the CP ring or the protective layer 7 is an inclined plane, and the angle between the inclined plane and the upper surface of the temperature compensation layer 11 is an acute angle θ. Based on the inclined plane, as shown in FIG. 4 , in the protective layer 7, the thickness of the protective layer 7 gradually increases in the direction from the inner side to the outer side. The above description of angles may also apply to other embodiments of the present invention.
在图4所示的实施例中,保护层7为CP环的形式,换言之,在顶电极的非电极连接端,保护层7沿温补层结构的周向上的至少一部分覆盖温补层结构的上表面,温补层结构的上表面的一部分经由保护层7的内缘限定的开口而露出,所述开口至少部分处于谐振器的有效区域内。这里的“开口”与CP环中的“环”对应。如后面提及的,CP环或开口可以封闭的,也可以非封闭的。如能够理解的以及后面如图7-8所示的,在温补层11还设置有种子层6的情况下,温补层结构包括温补层11以及种子层6,而在温补层11上侧并未设置种子层6的情况下,温补层结构包括温补层11。In the embodiment shown in FIG. 4 , the protective layer 7 is in the form of a CP ring, in other words, at the non-electrode connection end of the top electrode, the protective layer 7 covers at least a portion of the temperature compensation layer structure along the circumferential direction of the temperature compensation layer structure. The upper surface, a portion of the upper surface of the thermo-compensating layer structure, is exposed through an opening defined by the inner edge of the protective layer 7, the opening being at least partially within the effective area of the resonator. The "opening" here corresponds to the "ring" in the CP ring. As mentioned later, the CP ring or opening may or may not be closed. As can be understood and shown in FIGS. 7-8 later, in the case where the temperature compensation layer 11 is further provided with the seed layer 6 , the temperature compensation layer structure includes the temperature compensation layer 11 and the seed layer 6 , and the temperature compensation layer 11 is provided with the seed layer 6 . When the seed layer 6 is not provided on the upper side, the temperature compensation layer structure includes the temperature compensation layer 11 .
如图4所示,在顶电极的非电极连接端,保护层7的内缘在水平方向上顶电极9的非电极连接端的内侧。如能够理解的,保护层7的内缘在水平方向上也可以与顶电极9的非电极连接端齐平。As shown in FIG. 4 , at the non-electrode connection end of the top electrode, the inner edge of the protective layer 7 is on the inner side of the non-electrode connection end of the top electrode 9 in the horizontal direction. As can be understood, the inner edge of the protective layer 7 may also be flush with the non-electrode connection end of the top electrode 9 in the horizontal direction.
在图4中,温补层11的上侧还覆盖有第三种子层6。在图4所示的实施例中,在谐振器的有效区域内,保护层7实际上是覆盖在温补层上的第三种子层6。在图4所示的实施例中,保护层7沿所述温补层11的周向上的至少一部分覆盖第三种子层6的上表面,第三种子层6的上表面的一部分经由保护层7的内缘限定的开口而露出。In FIG. 4 , the upper side of the temperature compensation layer 11 is also covered with the third seed layer 6 . In the embodiment shown in FIG. 4 , in the effective area of the resonator, the protective layer 7 is actually the third seed layer 6 covering the temperature compensation layer. In the embodiment shown in FIG. 4 , the protective layer 7 covers the upper surface of the third seed layer 6 along at least a part of the circumferential direction of the temperature compensation layer 11 , and a part of the upper surface of the third seed layer 6 passes through the protective layer 7 The opening defined by the inner edge is exposed.
图7-8示例性示出了根据本发明的不同实施例的体声波谐振器的截面示意图,如图7和图8所示,温补层11上也可不设置第三种子层6。此时,保护层7沿温补层11的周向上的至少一部分覆盖温补层11自身的上表面,温补层的上表面的一部分经由保护层7的内缘限定的开口而露出。7-8 exemplarily show schematic cross-sectional views of bulk acoustic wave resonators according to different embodiments of the present invention. As shown in FIGS. 7 and 8 , the third seed layer 6 may not be provided on the temperature compensation layer 11 . At this time, the protective layer 7 covers the upper surface of the temperature compensation layer 11 itself along at least a part of the circumferential direction of the temperature compensation layer 11 , and a part of the upper surface of the temperature compensation layer is exposed through the opening defined by the inner edge of the protection layer 7 .
在图7所示的结构中,在制造时,与图4所示结构制造流程不同的是,在形成了温补层11之后,不沉积第三种子层6,沉积保护层材料后,直接通过剥离工艺(liftoff工艺)形成保护层7或CP环结构,以保护温补层11不在后续的步骤中被释放。在图7所示的结构中,因为不存在对保护材料层刻蚀从而也不存在对温补层11的露出部分的过刻,所以图7所示的温补层11露出部分的上表面为平坦的上表面。In the structure shown in FIG. 7 , the difference from the manufacturing process of the structure shown in FIG. 4 is that after the temperature compensation layer 11 is formed, the third seed layer 6 is not deposited, and the protective layer material is deposited directly through the A liftoff process forms the protective layer 7 or the CP ring structure to protect the temperature compensation layer 11 from being released in subsequent steps. In the structure shown in FIG. 7 , since there is no etching of the protective material layer and thus no overetching of the exposed portion of the temperature compensation layer 11 , the upper surface of the exposed portion of the temperature compensation layer 11 shown in FIG. 7 is flat top surface.
而在图8所示的结构中,在制造时,与图7所示结构制造流程不同的是,在形成了温补层11之后,不沉积第三种子层6,沉积保护层材料通过刻蚀工艺形成保护层7或CP环结构,以保护温补层11不在后续的步骤中被释放。但是,在刻蚀保护层材料的过程中,也会对温补层11形成过刻,从而温补 层11的上表面的露出部分为下凹的形状,即温补层的上表面的经由开口露出的部分相对于温补层的上表面的其他部分凹陷。In the structure shown in FIG. 8, the difference from the manufacturing process of the structure shown in FIG. 7 is that after the temperature compensation layer 11 is formed, the third seed layer 6 is not deposited, and the protective layer material is deposited by etching The process forms the protective layer 7 or the CP ring structure to protect the temperature compensation layer 11 from being released in subsequent steps. However, in the process of etching the protective layer material, the temperature compensation layer 11 is also over-etched, so that the exposed part of the upper surface of the temperature compensation layer 11 is in a concave shape, that is, the upper surface of the temperature compensation layer has an opening through the opening. The exposed portion is recessed with respect to other portions of the upper surface of the warm compensation layer.
如图4和7-8所示,保护层7覆盖底电极4的电极连接端的至少一部分和非电极连接端的至少一部分。如能够理解的,保护层7可以覆盖底电极4的电极连接端的至少一部分或非电极连接端的至少一部分。As shown in FIGS. 4 and 7-8 , the protective layer 7 covers at least a portion of the electrode connection end and at least a portion of the non-electrode connection end of the bottom electrode 4 . As can be appreciated, the protective layer 7 may cover at least a portion of the electrode connection end of the bottom electrode 4 or at least a portion of the non-electrode connection end.
在一个实施例中,参见图4和7-8中的右侧部分,在底电极的非电极连接端,保护层7覆盖底电极4且保护层7的外缘所在面与所述底电极的非电极连接端面齐平。In one embodiment, referring to the right part in FIGS. 4 and 7-8 , at the non-electrode connection end of the bottom electrode, the protective layer 7 covers the bottom electrode 4 and the outer edge of the protective layer 7 is on the surface of the bottom electrode. Non-electrode connection end faces are flush.
如上已经提及的,保护层或CP环结构形成的开口可以是封闭的,也可以不是封闭的。下面参照图9-11具体说明。图9-11示例性示出了根据本发明的不同实施例的体声波谐振器的俯视示意图。As already mentioned above, the opening formed by the protective layer or the CP ring structure may or may not be closed. The following is a detailed description with reference to FIGS. 9-11 . 9-11 illustrate schematic top views of bulk acoustic wave resonators according to various embodiments of the present invention.
在图9中,保护层7或CP环结构仅沿顶电极的非电极连接端的周向全部设置,而在顶电极的电极连接端并未设置。如能够理解的,保护层7或CP环结构也可以仅沿顶电极的非电极连接端的周向的一部分设置。In FIG. 9 , the protective layer 7 or the CP ring structure is only provided along the circumference of the non-electrode connection end of the top electrode, but not provided at the electrode connection end of the top electrode. As can be understood, the protective layer 7 or the CP ring structure may also be provided only along a part of the circumference of the non-electrode connection end of the top electrode.
在图10中,保护层7或CP环结构除了在顶电极的非电极连接端沿周向全部设置之外,还在顶电极的电极连接端部分设置。In FIG. 10 , the protective layer 7 or the CP ring structure is not only provided at the non-electrode connection end of the top electrode along the circumferential direction, but also provided at the electrode connection end of the top electrode.
在图11中,保护层7或CP环结构除了在顶电极的非电极连接端沿周向全部设置之外,在顶电极的电极连接端也全部设置。In FIG. 11 , the protective layer 7 or the CP ring structure is not only provided at the non-electrode connection end of the top electrode along the circumferential direction, but also at the electrode connection end of the top electrode.
图6示例性示出了保护层在温补层的上表面上的宽度与谐振器的性能之间的关系示意图。可以看到,保护层7在温补层的上表面上的宽度W1(参见图4)对于谐振器的性能有较大影响。如图6所示,在W1为0或2μm时,谐振器的并联谐振阻抗Rp的值较大,为550欧姆,而在W1为7μm时,谐振器的并联谐振阻抗Rp的值较小,为450欧姆。FIG. 6 exemplarily shows a schematic diagram of the relationship between the width of the protective layer on the upper surface of the temperature compensation layer and the performance of the resonator. It can be seen that the width W1 of the protective layer 7 on the upper surface of the temperature compensation layer (see FIG. 4 ) has a great influence on the performance of the resonator. As shown in Fig. 6, when W1 is 0 or 2 μm, the value of the parallel resonance impedance Rp of the resonator is larger, which is 550 ohms, while when W1 is 7 μm, the value of the parallel resonance impedance Rp of the resonator is smaller, which is 450 ohms.
相应的,在本发明的示例性实施例中,在顶电极9的非电极连接端,保护层7的内缘在水平方向上处于顶电极9的非电极连接端的内侧且两者之间的距离W1小于7μm,在进一步的实施例中,两者之间的距离W1不小于0且小于3μm。Correspondingly, in the exemplary embodiment of the present invention, at the non-electrode connection end of the top electrode 9, the inner edge of the protective layer 7 is located inside the non-electrode connection end of the top electrode 9 in the horizontal direction and the distance between the two is W1 is less than 7 μm, and in a further embodiment, the distance W1 between the two is not less than 0 and less than 3 μm.
需要指出的是,在本发明的一个实施例中,在谐振器的电极连接端处的CP环或保护层的尺寸无要求。在本发明的另外的实施例中,在谐振器的电极连接端处的CP环或保护层的尺寸限制可以与非电极连接端一致,均在本发明的保护范围内,这里不再赘述。It should be noted that, in one embodiment of the present invention, the size of the CP ring or the protective layer at the electrode connection end of the resonator is not required. In another embodiment of the present invention, the size limit of the CP ring or the protective layer at the electrode connecting end of the resonator may be the same as that of the non-electrode connecting end, which are all within the protection scope of the present invention, and will not be repeated here.
下面参照图12A-12F示例性说明图4所示的谐振器的制作过程。图12A-12F示例性示出了根据本发明的一个示例性实施例的制造图4所示的结构的方法的一系列截面示意图。The fabrication process of the resonator shown in FIG. 4 is exemplarily described below with reference to FIGS. 12A-12F. 12A-12F illustrate a series of schematic cross-sectional views of a method of fabricating the structure shown in FIG. 4 in accordance with an exemplary embodiment of the present invention.
步骤1:如图12A所示,提供基底1,利用刻蚀的方法在基底1上形成空腔,在基底1上沉积牺牲材料,该牺牲材料填充该空腔,接着,利用例如CMP工艺使得空腔内的牺牲材料层的表面与基底1的上表面齐平。如后面提及的,牺牲材料层被释放后形成声学镜空腔2。Step 1: As shown in FIG. 12A, a substrate 1 is provided, a cavity is formed on the substrate 1 by an etching method, a sacrificial material is deposited on the substrate 1, the sacrificial material fills the cavity, and then, a CMP process is used to make the cavity. The surface of the sacrificial material layer in the cavity is flush with the upper surface of the substrate 1 . As mentioned later, the sacrificial material layer is released to form the acoustic mirror cavity 2 .
步骤2:在图12A所示结构上依次沉积第一种子膜层和导电膜层,利用刻蚀工艺使得该两个膜层图形化而形成第一种子层3和底电极4,如图12B所示。Step 2: Deposit a first seed film layer and a conductive film layer in sequence on the structure shown in FIG. 12A, and pattern the two film layers by an etching process to form a first seed layer 3 and a bottom electrode 4, as shown in FIG. 12B. Show.
步骤3:在图12B的结构上沉积第二种子材料层,其可以为氮化铝。接着,在第二种子材料层上沉积温补材料层,其例如为二氧化硅。然后,对温补材料层图形化以形成温补层11,此时第二种子层5作为对底电极4进行保护的刻蚀阻挡层。此后,刻蚀第二种子材料层以形成第二种子层5。此后,沉积第三种子材料层,其可以是氮化铝,并对其刻蚀而图形化以形成第三种子层6。第三种子层6用于在后续步骤中对保护层或CP环进行刻蚀时作为阻挡层而保护温补层11。在二氧化硅温补层的上下两侧均设置种子层的情况下,有利于增加膜层间的粘附性,膜层结构更稳定。Step 3: Deposit a second seed material layer, which may be aluminum nitride, on the structure of FIG. 12B. Next, a layer of temperature compensation material, such as silicon dioxide, is deposited on the second seed material layer. Then, the temperature compensation material layer is patterned to form the temperature compensation layer 11 . At this time, the second seed layer 5 serves as an etch stop layer for protecting the bottom electrode 4 . Thereafter, the second seed material layer is etched to form the second seed layer 5 . Thereafter, a third seed material layer, which may be aluminum nitride, is deposited, etched and patterned to form the third seed layer 6 . The third seed layer 6 is used to protect the temperature compensation layer 11 as a barrier layer when the protective layer or the CP ring is etched in a subsequent step. In the case where seed layers are arranged on both the upper and lower sides of the silicon dioxide temperature compensation layer, it is beneficial to increase the adhesion between the film layers, and the film layer structure is more stable.
步骤4:如图12D所示,在图12C所示的结构上沉积保护材料层,然后,对保护材料层刻蚀以形成保护层7。在图12D中,可以看到保护层7的内侧限定了开口。在这一步骤中,在预定区域(例如顶电极的非电极连接端),保护层7沿温补层结构的周向上的至少一部分覆盖温补层结构的上表面,温补层结构的上表面的一部分经由保护层的内缘限定的开口而露出。此外,在这一步骤中,在预定区域(例如顶电极的非电极连接端),保护层7的内缘的位置需要设定为:在水平方向上与后续步骤制备的顶电极的非电极连接端齐平或者处于该顶电极的非电极连接端的内侧。Step 4: As shown in FIG. 12D , deposit a protective material layer on the structure shown in FIG. 12C , and then etch the protective material layer to form a protective layer 7 . In Figure 12D, it can be seen that the inner side of the protective layer 7 defines an opening. In this step, in a predetermined area (for example, the non-electrode connection end of the top electrode), the protective layer 7 covers the upper surface of the temperature compensation layer structure along at least a part of the circumferential direction of the temperature compensation layer structure, and the upper surface of the temperature compensation layer structure A portion is exposed through an opening defined by the inner edge of the protective layer. In addition, in this step, in a predetermined area (for example, the non-electrode connection end of the top electrode), the position of the inner edge of the protective layer 7 needs to be set so as to connect with the non-electrode of the top electrode prepared in the subsequent step in the horizontal direction. The end is flush or inside the non-electrode connection end of the top electrode.
步骤5:如图12E所示,在图12D的结构上沉积压电层8。Step 5: As shown in FIG. 12E, a piezoelectric layer 8 is deposited on the structure of FIG. 12D.
步骤6:如图12F所示,在图12E的结构上制备顶电极9和工艺层10,从而形成图4的结构。Step 6: As shown in FIG. 12F , the top electrode 9 and the process layer 10 are prepared on the structure of FIG. 12E , thereby forming the structure of FIG. 4 .
在本发明中,CP环或保护层7主要是为了防止温补层11被例如HF溶液的刻蚀剂释放或刻蚀。In the present invention, the CP ring or protective layer 7 is mainly to prevent the temperature compensation layer 11 from being released or etched by an etchant such as HF solution.
在本发明的一个实施例中,CP环或保护层7的外侧在水平方向上处于声学镜空腔的边界的外侧。在本发明的另外的实施例中,CP环或保护层7的外侧也可以在水平方向上处于声学镜空腔的边界的内侧。可选的,CP环或保护层7的外侧也可以在水平方向上也可以与顶电极的非电极连接端在水平方向上持平。这些均在本发明的保护范围之内。In one embodiment of the present invention, the outside of the CP ring or protective layer 7 is horizontally outside the boundary of the cavity of the acoustic mirror. In another embodiment of the present invention, the outer side of the CP ring or the protective layer 7 may also be in the inner side of the boundary of the acoustic mirror cavity in the horizontal direction. Optionally, the outer side of the CP ring or the protective layer 7 may also be horizontally level with the non-electrode connection end of the top electrode. These are all within the protection scope of the present invention.
本发明提出的结构还可适用于窄带产品需求,在保证机电耦合系数的前提下又可以满足性能需求。The structure proposed by the invention can also be suitable for narrow-band product requirements, and can meet the performance requirements on the premise of ensuring the electromechanical coupling coefficient.
对于没有温补保护层的谐振器(例如图1所示),机电耦合系数会随释放时间的加长而变化,但是具有根据本发明的保护层结构的谐振器的机电耦合系数稳定,不会随释放时间而变化。For a resonator without a temperature compensation protective layer (such as shown in FIG. 1 ), the electromechanical coupling coefficient changes with the increase of the release time, but the electromechanical coupling coefficient of the resonator with the protective layer structure according to the present invention is stable and does not change with the increase of the release time. varies with release time.
对于具有夹层电极12作为温补保护层的谐振器(例如图3所示),基于本发明的结构的谐振器的性能(谐振器的并联谐振阻抗Rp)有明显的提升,如图5所示。从图5可以看出,在其他条件相同的情况下,对于设置CM保护层(即设置夹层电极12)的图3所示的结构,谐振器的并联谐振阻抗Rp为170欧姆;而对于基于本发明的设置保护层7的例如如图4所示的结构,谐振器的并联谐振阻抗Rp为550欧姆。For the resonator with the interlayer electrode 12 as the temperature compensation protection layer (for example, as shown in FIG. 3 ), the performance of the resonator (parallel resonance impedance Rp of the resonator) based on the structure of the present invention is significantly improved, as shown in FIG. 5 . . It can be seen from FIG. 5 that under the same other conditions, for the structure shown in FIG. 3 with the CM protective layer (ie, the interlayer electrode 12) provided, the parallel resonance impedance Rp of the resonator is 170 ohms; In the inventive structure in which the protective layer 7 is provided, for example, as shown in FIG. 4 , the parallel resonance impedance Rp of the resonator is 550 ohms.
在本发明的一个实施例中,使用了本发明的保护层结构的体声波谐振器的机电耦合系数不大于3%。In one embodiment of the present invention, the electromechanical coupling coefficient of the bulk acoustic wave resonator using the protective layer structure of the present invention is not greater than 3%.
需要指出的是,在本发明中,各个数值范围,除了明确指出不包含端点值之外,除了可以为端点值,还可以为各个数值范围的中值,这些均在本发明的保护范围之内。It should be pointed out that, in the present invention, each numerical range, except that it is clearly indicated that it does not include the endpoint value, can be the endpoint value, and can also be the median value of each numerical range, and these are all within the protection scope of the present invention. .
在本发明中,上和下是相对于谐振器的基底的底面而言的,对于一个部件,其靠近该底面的一侧为下侧,远离该底面的一侧为上侧。In the present invention, upper and lower are relative to the bottom surface of the base of the resonator. For a component, the side close to the bottom surface is the lower side, and the side away from the bottom surface is the upper side.
在本发明中,内和外是相对于谐振器的有效区域的中心在横向方向或者径向方向上而言的,一个部件的靠近该中心的一侧或一端为内侧或内端,而该部件的远离该中心的一侧或一端为外侧或外端。对于一个参照位置而言,位于该位置的内侧表示在横向方向或径向方向上处于该位置与该中心之间,位于该位置的外侧表示在横向方向或径向方向上比该位置更远离该中心。In the present invention, the inner and outer are relative to the center of the effective area of the resonator in the lateral direction or the radial direction, the side or one end of a component close to the center is the inner or inner end, and the component The side or end away from the center is the outer or outer end. For a reference location, being located inside the location means being between the location and the center in the lateral or radial direction, and being located outside of the location means being farther from the location in the lateral or radial direction than the location is center.
如本领域技术人员能够理解的,根据本发明的体声波谐振器可以用于形成滤波器或其他半导体器件。As can be appreciated by those skilled in the art, BAW resonators according to the present invention may be used to form filters or other semiconductor devices.
基于以上,本发明提出了如下技术方案:Based on the above, the present invention proposes the following technical solutions:
1、一种体声波谐振器,包括:1. A bulk acoustic wave resonator, comprising:
基底;base;
声学镜;acoustic mirror;
底电极;bottom electrode;
顶电极;top electrode;
压电层,设置在底电极与顶电极之间;a piezoelectric layer, arranged between the bottom electrode and the top electrode;
温补层结构,设置在底电极与压电层之间,温补层结构包括温补层,The temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer, and the temperature compensation layer structure includes a temperature compensation layer,
其中:in:
所述谐振器还包括保护层;The resonator also includes a protective layer;
在顶电极的非电极连接端,所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述温补层结构的上表面,所述温补层结构的上表面的一部分经由保护层的内缘限定的开口而露出,所述开口至少部分处于谐振器的有效区域内;且At the non-electrode connection end of the top electrode, the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by exposed through an opening defined by the inner edge of the layer, the opening being at least partially within the active area of the resonator; and
在顶电极的非电极连接端,所述保护层的内缘在水平方向上与顶电极的非电极连接端齐平或者处于顶电极的非电极连接端的内侧。At the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or is located inside the non-electrode connection end of the top electrode.
2、根据1所述的谐振器,其中:2. The resonator according to 1, wherein:
所述保护层沿所述温补层的周向上的至少一部分覆盖所述温补层的上表面,所述温补层的上表面的一部分经由保护层的内缘限定的开口而露出。The protective layer covers an upper surface of the warm compensation layer along at least a part of the circumferential direction of the warm compensation layer, and a part of the upper surface of the warm compensation layer is exposed through an opening defined by an inner edge of the protective layer.
3、根据2所述的谐振器,其中:3. The resonator according to 2, wherein:
所述温补层的上表面为平坦上表面。The upper surface of the temperature compensation layer is a flat upper surface.
4、根据2所述的谐振器,其中:4. The resonator according to 2, wherein:
所述温补层的上表面的经由所述开口露出的部分相对于温补层的上表面的其他部分凹陷。The portion of the upper surface of the temperature compensation layer exposed through the opening is recessed relative to other portions of the upper surface of the temperature compensation layer.
5、根据1所述的谐振器,其中:5. The resonator according to 1, wherein:
所述温补层结构包括温补层以及在温补层的上侧包覆温补层的种子层;The temperature compensation layer structure includes a temperature compensation layer and a seed layer covering the temperature compensation layer on the upper side of the temperature compensation layer;
所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述种子层的上表面,所述种子层的上表面的一部分经由保护层的内缘限定的开口而露出。The protective layer covers an upper surface of the seed layer along at least a portion of the temperature compensation layer structure in the circumferential direction, and a portion of the upper surface of the seed layer is exposed through an opening defined by an inner edge of the protective layer.
6、根据1所述的谐振器,其中:6. The resonator according to 1, wherein:
所述保护层覆盖底电极的电极连接端的至少一部分和/或非电极连接端的至少一部分。The protective layer covers at least a part of the electrode connection end and/or at least a part of the non-electrode connection end of the bottom electrode.
7、根据6所述的谐振器,其中:7. The resonator according to 6, wherein:
在底电极的非电极连接端,所述保护层覆盖底电极且所述保护层的外缘所在面与所述底电极的非电极连接端面齐平。At the non-electrode connecting end of the bottom electrode, the protective layer covers the bottom electrode and the surface where the outer edge of the protective layer is located is flush with the non-electrode connecting end surface of the bottom electrode.
8、根据1所述的谐振器,其中:8. The resonator according to 1, wherein:
所述保护层的内缘为斜面,所述斜面与保护层所覆盖的温补层结构的上表面之间的夹角为锐角,基于所述斜面,在所述保护层的内缘,保护层的厚度在从内侧到外侧的方向上逐渐变大。The inner edge of the protective layer is an inclined plane, and the angle between the inclined plane and the upper surface of the temperature compensation layer structure covered by the protective layer is an acute angle. Based on the inclined plane, at the inner edge of the protective layer, the protective layer The thickness gradually increases from the inside to the outside.
9、根据8所述的谐振器,其中:9. The resonator of 8, wherein:
所述夹角的度数为所述底电极的非电极连接端的端部的夹角度数的90%-110%。The included angle is 90%-110% of the included angle of the end of the non-electrode connecting end of the bottom electrode.
10、根据1所述的谐振器,其中:10. The resonator of 1, wherein:
在顶电极的非电极连接端,所述保护层的内缘在水平方向上处于顶电极的非电极连接端的内侧且两者之间的距离小于7μm。At the non-electrode connection end of the top electrode, the inner edge of the protective layer is located inside the non-electrode connection end of the top electrode in the horizontal direction, and the distance therebetween is less than 7 μm.
11、根据10所述的谐振器,其中:11. The resonator of 10, wherein:
在顶电极的非电极连接端,所述保护层的内缘在水平方向上处于顶电极的非电极连接端的内侧且两者之间的距离小于3μm。At the non-electrode connection end of the top electrode, the inner edge of the protective layer is located inside the non-electrode connection end of the top electrode in the horizontal direction, and the distance therebetween is less than 3 μm.
12、根据1所述的谐振器,其中:12. The resonator of 1, wherein:
所述保护层为金属保护层。The protective layer is a metal protective layer.
13、根据6所述的谐振器,其中:13. The resonator according to 6, wherein:
所述保护层为金属保护层;且the protective layer is a metal protective layer; and
保护层与底电极电连接。The protective layer is electrically connected to the bottom electrode.
14、根据1-12中任一项所述的谐振器,其中:14. The resonator of any of 1-12, wherein:
所述保护层至少沿顶电极的整个非电极连接端设置。The protective layer is disposed along at least the entire non-electrode connection end of the top electrode.
15、根据14所述的谐振器,其中:15. The resonator of 14, wherein:
所述保护层仅沿顶电极的非电极连接端设置。The protective layer is only provided along the non-electrode connection end of the top electrode.
16、根据14所述的谐振器,其中:16. The resonator of 14, wherein:
所述保护层沿顶电极的整个非电极连接端以及顶电极的部分电极连接端设置。The protective layer is disposed along the entire non-electrode connection end of the top electrode and part of the electrode connection end of the top electrode.
17、根据14所述的谐振器,其中:17. The resonator of 14, wherein:
所述保护层为沿顶电极的整个非电极连接端以及顶电极的整个电极连接端设置的环状保护层。The protective layer is a ring-shaped protective layer arranged along the entire non-electrode connection end of the top electrode and the entire electrode connection end of the top electrode.
18、根据1所述的谐振器,其中:18. The resonator according to 1, wherein:
所述谐振器的机电耦合系数不大于3%。The electromechanical coupling coefficient of the resonator is not more than 3%.
19、一种体声波谐振器的制造方法,所述谐振器包括基底、声学镜、底电极、顶电极、设置在底电极与顶电极之间的压电层、包括温补层的温补层结构,所述温补层结构设置在底电极与压电层之间,19. A method for manufacturing a bulk acoustic wave resonator, the resonator comprising a substrate, an acoustic mirror, a bottom electrode, a top electrode, a piezoelectric layer arranged between the bottom electrode and the top electrode, a temperature compensation layer comprising a temperature compensation layer structure, the temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer,
所述方法包括步骤:The method includes the steps:
在底电极上形成温补层结构;A temperature compensation layer structure is formed on the bottom electrode;
在形成温补层结构之后,设置保护层,使得:After the temperature compensation layer structure is formed, the protective layer is arranged such that:
在顶电极的非电极连接端,所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述温补层结构的上表面,所述温补层结构的上表面的一部分经由保护层的内缘限定的开口而露出;以及在顶电极的非电极连接端,所述保护层的内缘在水平方向上与顶电极的非电极连接端齐平或者处于顶电极的非电极连接端的内侧。At the non-electrode connection end of the top electrode, the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by And at the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or at the non-electrode connection end of the top electrode. inside.
20、根据19所述的方法,其中:20. The method of 19, wherein:
设置保护层的步骤中,使得保护层仅沿顶电极的非电极连接端设置;或者,沿顶电极的整个非电极连接端以及顶电极的部分电极连接端设置;或者,沿顶电极的整个非电极连接端以及顶电极的整个电极连接端设置。In the step of arranging the protective layer, the protective layer is arranged only along the non-electrode connection end of the top electrode; or, along the entire non-electrode connection end of the top electrode and part of the electrode connection end of the top electrode; or, along the entire non-electrode connection end of the top electrode. The electrode connection end and the entire electrode connection end of the top electrode are provided.
21、根据19所述的方法,其中:21. The method of 19, wherein:
设置保护层的步骤包括:设置覆盖整个温补层结构的上表面的保护材料层;移除所述保护材料层的处于所述温补层结构的上表面的一部分以形成所述保护层,所述温补层结构的上表面的所述一部分至少部分处于谐振器的有效区域内。The step of disposing the protective layer includes: disposing a protective material layer covering the entire upper surface of the temperature compensation layer structure; removing a part of the protective material layer on the upper surface of the temperature compensation layer structure to form the protective layer, The portion of the upper surface of the temperature compensation layer structure is at least partially within the effective area of the resonator.
22、根据21所述的方法,其中:22. The method of 21, wherein:
利用刻蚀工艺移除所述保护材料层的处于所述温补层结构的上表面的一部分;或者Use an etching process to remove a portion of the upper surface of the protective material layer on the temperature compensation layer structure; or
利用剥离工艺移除所述保护材料层的处于所述温补层结构的上表面的一部分。A part of the upper surface of the thermal compensation layer structure of the protective material layer is removed by a lift-off process.
23、根据21所述的方法,其中:23. The method of 21, wherein:
在“移除所述保护材料层的处于所述温补层结构的上表面的一部分”的步骤中,使得最终形成的所述保护层的内缘在水平方向上处于顶电极的非电极连接端的内侧且两者之间的距离小于7μm。In the step of "removing a part of the protective material layer on the upper surface of the temperature compensation layer structure", the inner edge of the finally formed protective layer is horizontally positioned at the non-electrode connection end of the top electrode inside and the distance between them is less than 7 μm.
24、根据19-23中任一项所述的方法,其中:24. The method according to any one of 19-23, wherein:
所述保护层为金属保护层;且the protective layer is a metal protective layer; and
保护层与底电极电连接。The protective layer is electrically connected to the bottom electrode.
25、一种滤波器,包括根据1-18中任一项所述的体声波谐振器。25. A filter comprising the bulk acoustic wave resonator of any of 1-18.
26、一种电子设备,包括根据25所述的滤波器,或者根据1-18中任一项所述的体声波谐振器。26. An electronic device comprising the filter according to 25, or the bulk acoustic wave resonator according to any one of 1-18.
这里的电子设备,包括但不限于射频前端、滤波放大模块等中间产品,以及手机、WIFI、无人机等终端产品。The electronic equipment here includes but is not limited to intermediate products such as RF front-end, filter and amplifier modules, and terminal products such as mobile phones, WIFI, and drones.
尽管已经示出和描述了本发明的实施例,对于本领域的普通技术人员而言,可以理解在不脱离本发明的原理和精神的情况下可以对这些实施例进行变化,本发明的范围由所附权利要求及其等同物限定。Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is determined by It is defined by the appended claims and their equivalents.
Claims (26)
- 一种体声波谐振器,包括:A bulk acoustic wave resonator, comprising:基底;base;声学镜;acoustic mirror;底电极;bottom electrode;顶电极;top electrode;压电层,设置在底电极与顶电极之间;a piezoelectric layer, arranged between the bottom electrode and the top electrode;温补层结构,设置在底电极与压电层之间,温补层结构包括温补层,The temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer, and the temperature compensation layer structure includes a temperature compensation layer,其中:in:所述谐振器还包括保护层;The resonator also includes a protective layer;在顶电极的非电极连接端,所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述温补层结构的上表面,所述温补层结构的上表面的一部分经由保护层的内缘限定的开口而露出,所述开口至少部分处于谐振器的有效区域内;且At the non-electrode connection end of the top electrode, the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by exposed through an opening defined by the inner edge of the layer, the opening being at least partially within the active area of the resonator; and在顶电极的非电极连接端,所述保护层的内缘在水平方向上与顶电极的非电极连接端齐平或者处于顶电极的非电极连接端的内侧。At the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or is located inside the non-electrode connection end of the top electrode.
- 根据权利要求1所述的谐振器,其中:The resonator of claim 1, wherein:所述保护层沿所述温补层的周向上的至少一部分覆盖所述温补层的上表面,所述温补层的上表面的一部分经由保护层的内缘限定的开口而露出。The protective layer covers an upper surface of the temperature compensation layer along at least a part in the circumferential direction of the temperature compensation layer, and a part of the upper surface of the temperature compensation layer is exposed through an opening defined by an inner edge of the protection layer.
- 根据权利要求2所述的谐振器,其中:The resonator of claim 2, wherein:所述温补层的上表面为平坦上表面。The upper surface of the temperature compensation layer is a flat upper surface.
- 根据权利要求2所述的谐振器,其中:The resonator of claim 2, wherein:所述温补层的上表面的经由所述开口露出的部分相对于温补层的上表面的其他部分凹陷。The portion of the upper surface of the temperature compensation layer exposed through the opening is recessed relative to other portions of the upper surface of the temperature compensation layer.
- 根据权利要求1所述的谐振器,其中:The resonator of claim 1, wherein:所述温补层结构包括温补层以及在温补层的上侧包覆温补层的种子层;The temperature compensation layer structure includes a temperature compensation layer and a seed layer covering the temperature compensation layer on the upper side of the temperature compensation layer;所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述种子层的上表面,所述种子层的上表面的一部分经由保护层的内缘限定的开口而露出。The protective layer covers an upper surface of the seed layer along at least a portion of the temperature compensation layer structure in the circumferential direction, and a portion of the upper surface of the seed layer is exposed through an opening defined by an inner edge of the protective layer.
- 根据权利要求1所述的谐振器,其中:The resonator of claim 1, wherein:所述保护层覆盖底电极的电极连接端的至少一部分和/或非电极连接端的至少一部分。The protective layer covers at least a part of the electrode connection end and/or at least a part of the non-electrode connection end of the bottom electrode.
- 根据权利要求6所述的谐振器,其中:The resonator of claim 6, wherein:在底电极的非电极连接端,所述保护层覆盖底电极且所述保护层的外缘所在面与所述底电极的非电极连接端面齐平。At the non-electrode connecting end of the bottom electrode, the protective layer covers the bottom electrode and the surface where the outer edge of the protective layer is located is flush with the non-electrode connecting end surface of the bottom electrode.
- 根据权利要求1所述的谐振器,其中:The resonator of claim 1, wherein:所述保护层的内缘为斜面,所述斜面与保护层所覆盖的温补层结构的上表面之间的夹角为锐角,基于所述斜面,在所述保护层的内缘,保护层的厚度在从内侧到外侧的方向上逐渐变大。The inner edge of the protective layer is an inclined plane, and the angle between the inclined plane and the upper surface of the temperature compensation layer structure covered by the protective layer is an acute angle. Based on the inclined plane, at the inner edge of the protective layer, the protective layer The thickness gradually increases from the inside to the outside.
- 根据权利要求8所述的谐振器,其中:The resonator of claim 8, wherein:所述夹角的度数为所述底电极的非电极连接端的端部的夹角度数的90%-110%。The included angle is 90%-110% of the included angle of the end of the non-electrode connecting end of the bottom electrode.
- 根据权利要求1所述的谐振器,其中:The resonator of claim 1, wherein:在顶电极的非电极连接端,所述保护层的内缘在水平方向上处于顶电极的非电极连接端的内侧且两者之间的距离小于7μm。At the non-electrode connection end of the top electrode, the inner edge of the protective layer is located inside the non-electrode connection end of the top electrode in the horizontal direction, and the distance therebetween is less than 7 μm.
- 根据权利要求10所述的谐振器,其中:The resonator of claim 10, wherein:在顶电极的非电极连接端,所述保护层的内缘在水平方向上处于顶电极的非电极连接端的内侧且两者之间的距离小于3μm。At the non-electrode connection end of the top electrode, the inner edge of the protective layer is located inside the non-electrode connection end of the top electrode in the horizontal direction, and the distance therebetween is less than 3 μm.
- 根据权利要求1所述的谐振器,其中:The resonator of claim 1, wherein:所述保护层为金属保护层。The protective layer is a metal protective layer.
- 根据权利要求6所述的谐振器,其中:The resonator of claim 6, wherein:所述保护层为金属保护层;且the protective layer is a metal protective layer; and保护层与底电极电连接。The protective layer is electrically connected to the bottom electrode.
- 根据权利要求1-12中任一项所述的谐振器,其中:The resonator of any of claims 1-12, wherein:所述保护层至少沿顶电极的整个非电极连接端设置。The protective layer is disposed along at least the entire non-electrode connection end of the top electrode.
- 根据权利要求14所述的谐振器,其中:The resonator of claim 14, wherein:所述保护层仅沿顶电极的非电极连接端设置。The protective layer is only provided along the non-electrode connection end of the top electrode.
- 根据权利要求14所述的谐振器,其中:The resonator of claim 14, wherein:所述保护层沿顶电极的整个非电极连接端以及顶电极的部分电极连接端设置。The protective layer is disposed along the entire non-electrode connection end of the top electrode and part of the electrode connection end of the top electrode.
- 根据权利要求14所述的谐振器,其中:The resonator of claim 14, wherein:所述保护层为沿顶电极的整个非电极连接端以及顶电极的整个电极连接端设置的环状保护层。The protective layer is a ring-shaped protective layer arranged along the entire non-electrode connection end of the top electrode and the entire electrode connection end of the top electrode.
- 根据权利要求1所述的谐振器,其中:The resonator of claim 1, wherein:所述谐振器的机电耦合系数不大于3%。The electromechanical coupling coefficient of the resonator is not more than 3%.
- 一种体声波谐振器的制造方法,所述谐振器包括基底、声学镜、底电极、顶电极、设置在底电极与顶电极之间的压电层、包括温补层的温补层结构,所述温补层结构设置在底电极与压电层之间,A method for manufacturing a bulk acoustic wave resonator, the resonator comprising a substrate, an acoustic mirror, a bottom electrode, a top electrode, a piezoelectric layer disposed between the bottom electrode and the top electrode, and a temperature compensation layer structure including a temperature compensation layer, The temperature compensation layer structure is arranged between the bottom electrode and the piezoelectric layer,所述方法包括步骤:The method includes the steps:在底电极上形成温补层结构;A temperature compensation layer structure is formed on the bottom electrode;在形成温补层结构之后,设置保护层,使得:After the temperature compensation layer structure is formed, the protective layer is arranged such that:在顶电极的非电极连接端,所述保护层沿所述温补层结构的周向上的至少一部分覆盖所述温补层结构的上表面,所述温补层结构的上表面的一部分经由保护层的内缘限定的开口而露出;以及在顶电极的非电极连接端,所述保护层的内缘在水平方向上与顶电极的非电极连接端齐平或者处于顶电极的非电极连接端的内侧。At the non-electrode connection end of the top electrode, the protective layer covers at least a part of the temperature compensation layer structure along the circumferential direction of the upper surface of the temperature compensation layer structure, and a part of the upper surface of the temperature compensation layer structure is protected by And at the non-electrode connection end of the top electrode, the inner edge of the protective layer is flush with the non-electrode connection end of the top electrode in the horizontal direction or at the non-electrode connection end of the top electrode. inside.
- 根据权利要求19所述的方法,其中:The method of claim 19, wherein:设置保护层的步骤中,使得保护层仅沿顶电极的非电极连接端设置;或者,沿顶电极的整个非电极连接端以及顶电极的部分电极连接端设置;或者,沿顶电极的整个非电极连接端以及顶电极的整个电极连接端设置。In the step of arranging the protective layer, the protective layer is arranged only along the non-electrode connection end of the top electrode; or, along the entire non-electrode connection end of the top electrode and part of the electrode connection end of the top electrode; or, along the entire non-electrode connection end of the top electrode. The electrode connection end and the entire electrode connection end of the top electrode are provided.
- 根据权利要求19所述的方法,其中:The method of claim 19, wherein:设置保护层的步骤包括:设置覆盖整个温补层结构的上表面的保护材料层;移除所述保护材料层的处于所述温补层结构的上表面的一部分以形成所述保护层,所述温补层结构的上表面的所述一部分至少部分处于谐振器的有效区域内。The step of disposing the protective layer includes: disposing a protective material layer covering the entire upper surface of the temperature compensation layer structure; removing a part of the protective material layer on the upper surface of the temperature compensation layer structure to form the protective layer, The portion of the upper surface of the temperature compensation layer structure is at least partially within the effective area of the resonator.
- 根据权利要求21所述的方法,其中:The method of claim 21, wherein:利用刻蚀工艺移除所述保护材料层的处于所述温补层结构的上表面的一部分;或者Use an etching process to remove a portion of the upper surface of the protective material layer on the temperature compensation layer structure; or利用剥离工艺移除所述保护材料层的处于所述温补层结构的上表面的一部分。A part of the upper surface of the thermal compensation layer structure of the protective material layer is removed by a lift-off process.
- 根据权利要求21所述的方法,其中:The method of claim 21, wherein:在“移除所述保护材料层的处于所述温补层结构的上表面的一部分”的 步骤中,使得最终形成的所述保护层的内缘在水平方向上处于顶电极的非电极连接端的内侧且两者之间的距离小于7μm。In the step of "removing a part of the protective material layer on the upper surface of the temperature compensation layer structure", the inner edge of the finally formed protective layer is horizontally positioned at the non-electrode connection end of the top electrode inside and the distance between them is less than 7 μm.
- 根据权利要求19-23中任一项所述的方法,其中:The method of any one of claims 19-23, wherein:所述保护层为金属保护层;且the protective layer is a metal protective layer; and保护层与底电极电连接。The protective layer is electrically connected to the bottom electrode.
- 一种滤波器,包括根据权利要求1-18中任一项所述的体声波谐振器。A filter comprising a bulk acoustic wave resonator according to any one of claims 1-18.
- 一种电子设备,包括根据权利要求25所述的滤波器,或者根据权利要求1-18中任一项所述的体声波谐振器。An electronic device comprising the filter according to claim 25, or the bulk acoustic wave resonator according to any one of claims 1-18.
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US20140292150A1 (en) * | 2013-03-28 | 2014-10-02 | Avago Technologies General Ip (Singapore) Pte. Ltd. | Temperature compensated acoustic resonator device having an interlayer |
CN209710061U (en) * | 2019-04-04 | 2019-11-29 | 嘉兴宏蓝电子技术有限公司 | A kind of temperature compensating type thin film bulk acoustic wave resonator and communication device |
CN111327295A (en) * | 2020-02-12 | 2020-06-23 | 诺思(天津)微系统有限责任公司 | Piezoelectric filter, mass load realization method thereof and device comprising piezoelectric filter |
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