WO2021139117A1 - 用于制作声波谐振器复合基板及表声波谐振器及制造方法 - Google Patents

用于制作声波谐振器复合基板及表声波谐振器及制造方法 Download PDF

Info

Publication number
WO2021139117A1
WO2021139117A1 PCT/CN2020/099638 CN2020099638W WO2021139117A1 WO 2021139117 A1 WO2021139117 A1 WO 2021139117A1 CN 2020099638 W CN2020099638 W CN 2020099638W WO 2021139117 A1 WO2021139117 A1 WO 2021139117A1
Authority
WO
WIPO (PCT)
Prior art keywords
piezoelectric sheet
acoustic wave
layer
groove
composite substrate
Prior art date
Application number
PCT/CN2020/099638
Other languages
English (en)
French (fr)
Inventor
黄河
罗海龙
李伟
齐飞
Original Assignee
中芯集成电路（宁波）有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 中芯集成电路（宁波）有限公司 filed Critical 中芯集成电路（宁波）有限公司
Priority to JP2021527083A priority Critical patent/JP7291219B2/ja
Priority to US17/618,690 priority patent/US20220247375A1/en
Publication of WO2021139117A1 publication Critical patent/WO2021139117A1/zh

Links

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
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
    • 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
    • H03H9/02535—Details of surface acoustic wave devices
    • H03H9/02543—Characteristics of substrate, e.g. cutting angles
    • H03H9/02574—Characteristics of substrate, e.g. cutting angles of combined substrates, multilayered substrates, piezoelectrical layers on not-piezoelectrical substrate
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/08—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of resonators or networks using surface acoustic waves
    • 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
    • H03H9/02535—Details of surface acoustic wave devices
    • H03H9/02543—Characteristics of substrate, e.g. cutting angles
    • H03H9/02559—Characteristics of substrate, e.g. cutting angles of lithium niobate or lithium-tantalate substrates
    • 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

  • the present invention relates to the field of semiconductor manufacturing, in particular to a composite substrate and surface acoustic wave resonator used for manufacturing an acoustic wave resonator and a manufacturing method.
  • a surface acoustic wave is an elastic wave that is generated and propagated on the surface of a piezoelectric sheet, and its amplitude decreases rapidly as the depth of the piezoelectric sheet increases.
  • the basic structure of the surface acoustic wave filter is to fabricate two acousto-electric transducers-interdigital transducers on the polished surface of the substrate material with piezoelectric characteristics.
  • Transducer, IDT respectively used as a transmitting transducer and a receiving transducer.
  • the transmitting transducer converts the RF signal into a surface acoustic wave and propagates on the surface of the substrate.
  • the receiving transducer converts the acoustic signal into an electrical signal for output.
  • the filtering process is from electrical to acoustic and acoustic to electrical
  • the piezoelectric conversion is realized.
  • the piezoelectric sheet of the acoustic wave device is formed on the substrate, and the bonding strength between the piezoelectric sheet and the substrate is not enough, and it is easy to fall off; in addition, the piezoelectric sheet is cracked due to lateral deformation.
  • the purpose of the present invention is to provide a method for manufacturing an acoustic wave resonator composite substrate and a surface acoustic wave resonator, which solves the problem that when the piezoelectric sheet is combined with the substrate, the bonding strength is not high, which causes the piezoelectric sheet to fall off, and the transverse direction of the piezoelectric sheet Piezoelectric chip fracture caused by deformation.
  • the present invention provides a method for manufacturing a composite substrate, including:
  • the substrate including a first surface and a second surface opposed to each other;
  • a piezoelectric sheet is provided, the piezoelectric sheet matches the shape of the first groove, and the bottom surface of the first groove is combined with the piezoelectric sheet by bonding.
  • the present invention also provides a method for manufacturing a surface acoustic wave resonator, using the above-mentioned composite substrate, and the manufacturing method includes:
  • a first interdigital transducer and a second interdigital transducer are formed on the top surface of the piezoelectric sheet.
  • the present invention also provides a composite substrate, including:
  • a substrate comprising a first surface and a second surface opposed to each other;
  • the first surface is provided with a first groove recessed toward the second surface
  • the piezoelectric sheet is embedded in the first groove, and the top surface of the piezoelectric sheet is higher than or flush with the first surface.
  • the present invention also provides a surface acoustic wave resonator, including the above-mentioned composite substrate.
  • the beneficial effect of the present invention is that the piezoelectric sheet is embedded in the first groove, and the side wall of the first groove can block the movement of the piezoelectric sheet, prevent the piezoelectric sheet from falling off, and improve the bonding strength; the first groove can also Limit the lateral deformation of the piezoelectric sheet and reduce the risk of fragmentation caused by the deformation of the piezoelectric sheet.
  • the current common method of manufacturing surface acoustic wave resonators is to bond the piezoelectric sheet on a silicon wafer of the same size. Silicon wafers usually have 12-inch, 8-inch, and 6-inch specifications. If the silicon wafer production line is an 8-inch production line, then an 8-inch piezoelectric sheet is used.
  • a 6-inch piezoelectric sheet it is suitable for a 6-inch production line, which means that an 8-inch production line cannot use a 6-inch piezoelectric sheet.
  • the invention can be adapted to production lines of different specifications under the condition that the specifications of the piezoelectric sheet are fixed.
  • the silicon dioxide layer, silicon, and silicon nitride are used as the bonding layer, which can be formed directly on the bottom of the piezoelectric sheet or the first groove by a deposition method, which is suitable for semiconductor processes.
  • the silicon dioxide layer can also As the temperature compensation layer of the piezoelectric sheet;
  • a stress buffer layer and a stress compensation layer are formed at the bottom of the first groove.
  • the stress compensation layer is used to offset the stress of the bonding layer.
  • the stress buffer layer solves the problem of the large difference in stress between the stress compensation layer and the substrate.
  • the stress compensation layer also has a sound reflection function, which can reflect sound waves back into the piezoelectric sheet and reduce the energy loss of sound waves;
  • a plurality of protrusions are provided at the bottom of the first groove, and a second groove that matches the protrusions is provided on the bottom surface of the piezoelectric sheet, on the one hand, the bonding strength of the piezoelectric sheet and the substrate can be increased;
  • the protrusion when the height of the protrusion is slightly higher than that of the first surface, the protrusion can be used as a polishing stop layer, which is beneficial to the control of the thickness of the piezoelectric sheet;
  • the piezoelectric material is relatively fragile and easy to break during cutting.
  • the material is a dielectric layer or silicon protrusions are distributed on the cutting track, the piezoelectric material is avoided when cutting, but the dielectric material such as silicon nitride or silicon is cut. Material, this can solve the problem of cracking of the piezoelectric substrate when cutting.
  • FIG. 1 is a flowchart of the steps of a method for manufacturing a composite substrate according to a first embodiment of the present invention.
  • 2 to 8 are schematic diagrams of the structure corresponding to each step of the manufacturing method of the composite substrate according to the first embodiment of the present invention.
  • FIG. 9A to FIG. 14 are schematic diagrams of the structure corresponding to different steps in the manufacturing method of the composite substrate of the second embodiment of the present invention.
  • first element, component, region, layer or section discussed below may be represented as a second element, component, region, layer or section.
  • Spatial relationship terms such as “under”, “below”, “below”, “below”, “above”, “above”, etc., in It can be used here for the convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatial relationship terms are intended to include different orientations of devices in use and operation. For example, if the device in the figure is turned over, then elements or features described as “under” or “below” or “under” other elements will be oriented “on” the other elements or features. Therefore, the exemplary terms “below” and “below” can include both an orientation of above and below. The device can be otherwise oriented (rotated by 90 degrees or other orientation) and the spatial descriptors used here are interpreted accordingly.
  • the method herein includes a series of steps, and the order of these steps presented herein is not necessarily the only order in which these steps can be performed, and some steps may be omitted and/or some other steps not described herein may be added to this method. If the components in a certain drawing are the same as those in other drawings, although these components can be easily identified in all the drawings, in order to make the description of the drawings more clear, this specification will not describe all the same components. The reference numbers are shown in each figure.
  • FIG. 1 is a flowchart of a method for manufacturing a composite substrate of the present invention. Please refer to FIG. The second surface; a first groove recessed to the second surface is formed on the first surface. S02: The piezoelectric sheet is provided to be embedded in the first groove, and the shape of the piezoelectric sheet matches the shape of the first groove, and the bottom surface of the first groove is combined with the piezoelectric sheet by bonding.
  • the side wall of the first groove can block the movement of the piezoelectric sheet, prevent the piezoelectric sheet from falling off, and improve the bonding strength; the first groove can also limit the lateral deformation of the piezoelectric sheet , To reduce the risk of chipping caused by the deformation of the piezoelectric sheet; in addition, the current common method of manufacturing surface acoustic wave resonators is to bond the piezoelectric sheet to a silicon wafer of the same size. Silicon wafers usually have 12-inch, 8-inch, and 6-inch specifications. If the silicon wafer production line is an 8-inch production line, then an 8-inch piezoelectric sheet is used.
  • a 6-inch piezoelectric sheet it is suitable for a 6-inch production line, which means that an 8-inch production line cannot use a 6-inch piezoelectric sheet.
  • the invention can be adapted to production lines of different specifications under the condition that the specifications of the piezoelectric sheet are fixed.
  • FIGS. 2 to 8 are schematic diagrams of the structure corresponding to each step in the first embodiment of the manufacturing method of the composite substrate of the present invention.
  • step S01 is performed to provide a substrate 10, the substrate 10 includes a first surface and a second surface opposite to each other, and a first groove 101 recessed toward the second surface is formed on the first surface.
  • the substrate 10 serves as the carrier of the piezoelectric sheet, has a relatively low thermal expansion coefficient, and can be adapted to semiconductor processing technology.
  • the substrate is an 8-inch silicon wafer with a thickness of about 600-800 microns.
  • the substrate 10 may also be any one of the following materials: sapphire, crystal, germanium (Ge), silicon germanium (SiGe), carbon silicon (SiC), carbon germanium silicon (SiGeC), indium arsenide (InAs), gallium arsenide (GaAs), indium phosphide (InP) or other III/V compound semiconductors.
  • the size can also be 12 inches, 6 inches, 4 inches, etc.
  • the first groove 101 is used for accommodating the piezoelectric sheet embedded in the later process.
  • the size of the formed first groove 101 matches the size of the piezoelectric sheet, so that the piezoelectric sheet fits into the first groove 101 exactly.
  • the first groove 101 formed in this embodiment is circular with a diameter slightly larger than 6 inches.
  • the depth of the first groove 101 is 0.5-10 microns.
  • the depth of the first groove 101 is determined by the set thickness of the piezoelectric sheet ultimately required.
  • the thickness of the piezoelectric sheet after grinding is set to 0.3-10 microns.
  • a first groove 101 of a predetermined size is formed on the first surface of the substrate 10 through an etching process.
  • the specific etching steps are: using a photolithography process to open the photoresist at the position of the groove that needs to be etched, and then using a special chemical wet etching to etch the substrate 10 into a groove 101 of a set size.
  • the etching is performed layer by layer along the crystal lattice, and the finally formed etching bottom surface is very flat, which is conducive to the subsequent bonding process.
  • the etching depth can be precisely controlled by controlling the process time.
  • the etched side surface can also get a very flat surface, the side inclination angle is between 45 degrees and 90 degrees (refers to the angle between the side wall and the bottom surface of the groove, the opening of the groove is large and small, and it is expected to be close to 90 degrees. degree).
  • the size of the bottom surface of the groove is substantially equal to that of the piezoelectric sheet.
  • step S02 is performed to provide the piezoelectric sheet 20 to be embedded in the first groove.
  • the piezoelectric sheet 20 matches the shape of the first groove 101, and the bottom surface of the first groove 101 is bonded to The piezoelectric sheet 20 is combined.
  • the shape coincidence here does not mean that the shape is exactly the same, it needs to be ensured that the piezoelectric sheet can be embedded in the first groove, and the shapes of the two are approximately the same. For example, if the side inclination angle of the first groove is 90 degrees, the shapes of the two are basically the same. If the side inclination angle is not 90 degrees, the shapes of the two will not be the same, but the overall shape is roughly the same to ensure that the piezoelectric sheet can It is embedded in the first groove, and there will not be too many gaps.
  • the piezoelectric sheet 20 is a 6-inch piezoelectric wafer with a thickness of about 300-600 microns.
  • the material of the piezoelectric sheet 20 includes: piezoelectric crystals or piezoelectric ceramics, such as: lithium phosphate , Lithium carbonate, lead zirconate titanate (PZT), lithium niobate (LiNbO3), quartz (Quartz), potassium niobate (KNbO3), lithium tantalate (LiTaO3), lithium gallate, lithium germanate, titanium germanate or Piezoelectric materials with wurtzite crystal structure such as lead zinc sphene and their combinations.
  • piezoelectric crystals or piezoelectric ceramics such as: lithium phosphate , Lithium carbonate, lead zirconate titanate (PZT), lithium niobate (LiNbO3), quartz (Quartz), potassium niobate (KNbO3), lithium tantalate (L
  • the piezoelectric sheet 20 is made of lithium niobate
  • the axial direction is 41° and the reference side direction is 64°.
  • the transmission loss of the film is small.
  • the material of the piezoelectric sheet 20 is lithium tantalate
  • the axial direction is 42° and the reference side direction is 112°
  • the transmission loss of the piezoelectric sheet is small.
  • the piezoelectric sheet 20 is a single crystal crystal.
  • the bonding method adopts fusion bonding.
  • the specific bonding method is as follows: referring to FIG. 5, a first bonding layer 13 is formed on the bottom surface and sidewall of the first groove; The bottom surface (the surface opposite to the first groove) forms the second bonding layer 21; referring to FIG. 7, the piezoelectric sheet 20 and the substrate 10 are bonded together through the first bonding layer 13 and the second bonding layer 21 . Bonding layers are formed on the bottom surface of the first groove 101 and the bottom surface of the piezoelectric sheet 20 respectively, and the piezoelectric sheet 20 is embedded in the first groove 101 through the double-sided bonding layer.
  • the material of the first bonding layer 13 and the second bonding layer 21 only needs to be able to realize the bonding function.
  • the bonding material includes silicon dioxide, polysilicon, silicon nitride, or metal. These bonding materials can be formed directly on the bottom of the piezoelectric sheet 20 or the first groove 101 by a deposition method, which is suitable for semiconductor processes.
  • the silicon dioxide layer can also be used as a temperature compensation layer of the piezoelectric sheet.
  • the first bonding layer 13 is a silicon oxide material and the substrate 10 is a silicon substrate, the first bonding layer 13 may also be formed by thermal oxidation.
  • the thicknesses of the first bonding layer 13 and the second bonding layer 21 are generally greater than 0.3 microns. Considering the process time and cost, the first bonding layer 13 and the second bonding layer 21 are not suitable for being too thick. The thickness of the first bonding layer 13 and the second bonding layer 21 is generally between 0.3 and 1 micrometer.
  • the first bonding layer 13 when the first bonding layer 13 is formed, the first bonding layer is also formed on the upper surface of the substrate 10 outside the first groove. This part of the first bonding layer can be removed or retained , Can be determined according to actual process requirements.
  • the bonding layer is formed on both the base and the piezoelectric sheet, but it is also possible to form only the second bonding layer on the piezoelectric sheet, and the base is made of a material that is easy to bond with the second bonding layer, such as silicon. It is also possible to form a first bonding layer on the substrate, and the material of the first bonding layer is selected from a material that is easy to bond with the piezoelectric sheet.
  • the fusion bonding in the present invention includes: forming a first bonding layer on the first groove and/or forming a second bonding layer on the bottom surface of the piezoelectric sheet, and bonding the substrate and the piezoelectric sheet through the bonding layer, and is not limited to The double-layer bonding shown in the example in the figure.
  • the method of bonding the substrate and the piezoelectric sheet is not limited to the above fusion bonding, and may also be covalent bonding or adhesive bonding.
  • the bottom surface of the piezoelectric sheet and the bottom surface of the first groove need to be flattened to make the surface reach the required smoothness, so that the bottom surface of the piezoelectric sheet and the bottom surface of the first groove can rely on The molecular force between the two is combined.
  • an adhesive such as epoxy resin
  • it before forming the first bonding layer 13 on the bottom surface of the first groove 101, it further includes forming a stress buffer layer 11 and a stress compensation layer 12.
  • a stress buffer layer and a stress compensation layer are formed at the bottom of the first groove, the stress compensation layer is used to offset the stress of the bonding layer, and the stress buffer layer solves the problem of the large difference in stress between the stress compensation layer and the substrate. If the stress between the substrate 10 and the piezoelectric sheet 20 is not buffered and offset, the stress difference between the two is likely to be large, and the substrate 10 will be warped.
  • at least one of the stress buffer layer 11 and the stress compensation layer 12 is also an acoustic wave reflection layer, which has an acoustic wave reflection function.
  • the material of the substrate 10 is silicon
  • the material of the stress buffer layer 11 includes silicon dioxide
  • the material of the stress compensation layer 12 includes silicon nitride, silicon carbide or boron nitride, or a metal material such as molybdenum, aluminum, tungsten or thallium.
  • the stress compensation layer 12 made of silicon nitride, silicon carbide, or boron nitride, or molybdenum, aluminum, tungsten, thallium or potassium also has an acoustic wave reflection function and can serve as an acoustic wave reflection layer.
  • the thickness of the stress buffer layer and the stress compensation layer may be between 0.08 ⁇ m and 1 ⁇ m, and the specific thickness value may be adjusted according to the target of stress compensation and the requirements of acoustic reflection.
  • the stress buffer layer and the stress compensation layer may not be formed, and the acoustic wave reflection layer may be formed on the bottom surface of the first groove and/or the bottom surface of the piezoelectric sheet.
  • the acoustic wave reflection layer is a single-layer film or a multi-layer film.
  • the material of the acoustic wave reflection layer includes at least one of silicon carbide, silicon nitride, molybdenum, and aluminum.
  • a stress buffer layer Before bonding, form an acoustic wave reflection layer on the bottom surface of the first groove, and then form a stress buffer layer and a stress compensation layer; or, first form a stress buffer layer and a stress compensation layer on the bottom surface of the first groove, and then form an acoustic wave reflection layer Floor.
  • the above bonding layer, stress buffer layer, and stress compensation layer after forming the above bonding layer, stress buffer layer, and stress compensation layer, it further includes: performing ion beam trimming process on each film separately to make the surface of each film smooth and flat, which can increase the subsequent bonding process
  • the bond strength between the substrate and the piezoelectric sheet in order to improve the bonding strength, it also includes at least the step of surface activation of the first bonding layer 13 or the second bonding layer 21.
  • the surface activation measures include the use of ozone water treatment, UV ozone treatment, plasma treatment, and ion beam treatment. Any of them.
  • vertical optical alignment can be performed by an alignment device, so that the piezoelectric sheet 20 is embedded in the first groove 101, and then the first bonding layer 13 and the second bonding layer 21 are bonded.
  • the piezoelectric sheet 20 is embedded in the first groove 101, and the side wall of the first groove 101 has a restrictive effect on the movement of the piezoelectric sheet 20, and plays a role in strengthening the bonding strength. .
  • the piezoelectric sheet 20 is thinned in a later process, the piezoelectric sheet 20 will not peel off from the substrate 10.
  • the piezoelectric sheet is difficult to be peeled from the substrate 10 due to the double guarantee of the grooved clamping and the side bonding.
  • the side wall of the first groove 101 limits the lateral deformation of the piezoelectric sheet 20, and improves the split problem caused by the transverse deformation of the piezoelectric sheet 20 (such as temperature-affected ).
  • the sidewall of the first groove 101 is also formed with a first bonding layer 13, a stress buffer layer 11, and a stress compensation layer 12.
  • a protective layer and an acoustic reflection layer are formed on the sidewall of the piezoelectric sheet 20 to prevent the piezoelectric sheet from being broken. Cracks and sound waves leak.
  • a thinning process is performed on the top surface of the piezoelectric sheet 20 to make the piezoelectric sheet 20 reach a predetermined thickness.
  • the thinning process includes the following steps:
  • the upper surface of the piezoelectric sheet 20 is mechanically polished to reduce the thickness of the piezoelectric sheet 20 to 25-35 microns.
  • Physical mechanical grinding equipment is used to rough-grind the upper surface of the piezoelectric sheet 20. The grinding accuracy is not high. Conventional grinding equipment can be used, and equipment with a faster grinding speed can be selected to reduce the grinding time.
  • CMP chemical mechanical polishing
  • the upper surface of the piezoelectric sheet 20 is continuously polished by chemical mechanical polishing (CMP).
  • CMP chemical mechanical polishing
  • it also includes: trimming the upper surface of the piezoelectric sheet 20 through an ion beam trimming process, and the surface roughness index of the piezoelectric sheet 20 after trimming (the thickest part and the thinnest part)
  • the height difference of the part) is less than 10 nanometers.
  • the trimming of the ion beam can reach the nanometer level. Not only can the entire surface of the piezoelectric sheet 20 be trimmed, but also the local height can be adjusted.
  • the ion beam trimming process adopts the following parameters: the ion beam current is 25 mA to 200 mA, and the scanning time of the entire wafer is 30 seconds to 10 minutes.
  • annealing the piezoelectric sheet 20 by using a furnace tube or a laser to repair the lattice damage of the piezoelectric sheet 20 includes: putting the substrate 10 into a high-temperature furnace, such as a horizontal furnace, a vertical furnace, and rapid thermal processing (RTP). In Heat at a temperature of 1100 to 1200 degrees for 2 to 5 minutes.
  • a high-temperature furnace such as a horizontal furnace, a vertical furnace, and rapid thermal processing (RTP). In Heat at a temperature of 1100 to 1200 degrees for 2 to 5 minutes.
  • Laser annealing includes: applying a pulsed laser of 0.8-015 joules per square centimeter to the piezoelectric sheet for 30 seconds to 600 seconds, heating the local temperature of the piezoelectric sheet 20 to 1100 degrees to 1300 degrees, reaching a molten state, and recrystallizing for repair damage.
  • the annealed piezoelectric sheet 20 has better piezoelectric characteristics. The difference between the two annealing treatments is that the first method is to heat the substrate 10 and the piezoelectric sheet 20 as a whole, and the second method can heat only the surface of the piezoelectric sheet.
  • a filling layer may be deposited after the substrate and the piezoelectric sheet are bonded.
  • the filling layer fills the gap between the piezoelectric sheet and the first groove.
  • the filling layer may only be filled in the gap, or the filling layer may simultaneously cover the top surface of the piezoelectric sheet (the surface opposite to the substrate) and the surface part of the substrate before the first groove.
  • the filling layer on the top surface of the piezoelectric sheet is first required. After thinning, the piezoelectric sheet is thinned to the set thickness. Whether the portion of the filling layer on the substrate outside the first groove is thinned can be determined according to actual requirements. Alternatively, it is also possible to first thin the piezoelectric sheet to a certain thickness, and then perform the above-described process of forming the filling layer.
  • the filling layer may be a dielectric layer, such as silicon dioxide, in which case the silicon dioxide may be used as a temperature compensation layer.
  • the filling layer can also be a dielectric layer with a stress buffer function to relieve the stress between the piezoelectric sheet and the substrate.
  • a protrusion is formed on the bottom surface of the first groove, and a second groove is formed on the bottom surface of the piezoelectric sheet; or, a second groove is formed on the bottom surface of the first groove, and the piezoelectric A protrusion is formed on the bottom surface of the sheet; the protrusion matches the shape of the second groove and is located in the non-device area of the composite substrate.
  • the first bonding layer 13 before forming the first bonding layer 13, it further includes: forming a plurality of protrusions 30 on the bottom surface of the first groove 101; the height of the protrusions 30 may be lower than the first surface, Or higher than the first surface. Referring to FIG. 9A, the height of the protrusion 30 is lower than the first surface, and referring to FIG. 9B, the height of the protrusion 30 is level with the first surface.
  • the method further includes: forming a plurality of second grooves matching the protrusions 30 on the surface of the piezoelectric sheet 20 opposite to the first groove 101 31.
  • the second groove 31 and the protrusion 30 are locked together.
  • the other steps are the same as in the first embodiment.
  • the shape of the second groove 31 matches the shape of the protrusion 30, and the size is slightly larger than that of the protrusion 30, as long as it can accommodate the protrusion.
  • the second groove 31 may be formed on the bottom surface of the piezoelectric sheet 20 by a dry etching process.
  • the second groove 31 may be formed before the second bonding layer 21 is formed, or may be formed after the second bonding layer 21 is formed. Referring to FIG. 11, when the second groove 31 is formed after the second bonding layer 21 is formed, there is no second bonding layer at the bottom of the second groove 31. Referring to FIG. 12, when the second groove 31 is formed before the second bonding layer 21 is formed, the bottom and side surfaces (not shown) of the second groove 31 also form the second bonding layer 21.
  • the thickness of the different film layer and the thickness of the piezoelectric sheet can be formed. The thickness forms the height of the protrusion and the required depth of the second groove.
  • the method for forming the protrusion 30 includes: after the first groove is formed by etching, the bottom of the first groove is patterned by a photolithography process to form the protrusion 30, or the first recess is formed by etching. After the grooves, a dielectric layer is deposited on the bottom surface of the first groove, and the dielectric layer is etched to form protrusions 30. Then, a stress buffer layer, a stress compensation layer and a first bonding layer are formed. The function of the protrusion 30 increases the bonding area between the piezoelectric sheet and the substrate 10, thereby enhancing the bonding strength between the two. Referring to FIG.
  • the method for forming the protrusion 30 may further include: patterning the substrate 10 to form the first groove 101 with the protrusion 30. At this time, the protrusion 30 can not only increase the bonding strength of the piezoelectric sheet and the substrate. When the height of the protrusion 30 is higher than or flush with the first surface of the substrate 10, the protrusion 30 may serve as a polishing stop layer. Referring to Figure 9B and Figure 13, the top surface of the piezoelectric sheet is higher than the base. After the piezoelectric sheet is bonded to the base, it also includes a grinding and thinning process for the piezoelectric sheet 20 (refer to FIG.
  • the protrusions 30 are formed on the first On the bottom surface of the groove, the protrusion 30 serves as a polishing stop layer for the polishing and thinning process, or the top surface of the protrusion 30 is formed with a polishing stop layer.
  • the bump 30 is used as a polishing stop layer in two cases. In the first case, the bump material is different from the substrate material. After a dielectric layer such as silicon nitride is formed by a deposition process, a photolithography process is performed on the dielectric layer to form bumps. At this time, the protrusion itself can be used as a polishing stop layer.
  • the stress buffer layer and the stress compensation layer are formed after the protrusions are formed, the stress buffer layer or the stress compensation layer on the top surface of the protrusions can be used as the polishing stop layer.
  • the stress compensation layer can be silicon nitride, and the stress compensation layer can also be used as a polishing stop layer.
  • the second case is adopted, and silicon nitride is selected as the stress compensation layer, which can be used as a stop layer for grinding and thinning the piezoelectric sheet.
  • Figure 10 for a diagram of one arrangement of protrusions.
  • the protrusions 30 are arranged in a grid form.
  • the protrusions 30 are formed on the bottom surface of the first groove.
  • the material of the protrusions 30 is a dielectric layer or silicon.
  • the road has a strip structure.
  • the material of the piezoelectric sheet itself is relatively fragile and easy to break during cutting.
  • the material distributed on the cutting path is a dielectric layer or bumps of silicon material.
  • the piezoelectric material is avoided during cutting, but the dielectric material such as nitrogen is cut. Silicon, which can solve the problem of cracking of the piezoelectric substrate when cutting.
  • the convex top surface is higher than or flush with the first surface, and the convex top surface is not covered by the piezoelectric sheet. This can completely avoid cutting the piezoelectric material when cutting the composite substrate.
  • the distribution form of the protrusions is not limited to the form shown in FIG. 10, and it may also be distributed in dots to enhance the bonding strength.
  • the difference between the second embodiment and the first embodiment is mainly whether the protrusion and the second groove are formed.
  • the other steps are the same as those of the first embodiment, and will not be repeated here.
  • FIG. 8 is a schematic structural diagram of a composite substrate according to an embodiment of the present invention. Please refer to FIG. The first surface and the second surface; the first surface is provided with a first groove recessed to the second surface; the piezoelectric sheet 20, the piezoelectric sheet 20 is embedded in the first groove and bonded with the substrate 10, the piezoelectric sheet 20
  • the top surface is higher than the first surface or is flat with the surface of the composite substrate.
  • the surface of the composite substrate is flat.
  • the bonding method includes one of covalent bonding, adhesive bonding, and fusion bonding. For the description of the specific bonding method, please refer to the related content of the method section.
  • a first bonding layer is formed on the bottom and side walls of the first groove, and a second bonding layer is provided on the surface of the piezoelectric sheet opposite to the first groove.
  • a stress buffer layer and a stress compensation layer are further included, wherein the stress compensation layer is located between the stress buffer layer and the first bonding layer.
  • the method of fusion bonding is not limited to the description in the previous paragraph, as long as the following requirements are met: the first bonding layer is arranged on the bottom and side walls of the first groove; and/or the second bonding layer is arranged on the The surface of the piezoelectric sheet opposite to the first groove.
  • there is an acoustic wave reflection layer between the piezoelectric sheet and the substrate and the acoustic wave reflection layer may be located between the stress buffer layer, the upper surface or the lower surface of the stress compensation layer, or both, or between the substrate
  • the stress buffer layer and the stress compensation layer are sequentially located in the first groove, and at least one of the stress buffer layer and the stress compensation layer is an acoustic wave reflection layer.
  • the first groove 101 further includes a plurality of protrusions 30; referring to FIGS. 11 and 12, the bottom surface of the piezoelectric sheet 20 includes a plurality of protrusions 30 opposite to each other.
  • the protrusion serves as a grinding stop layer, which is beneficial and beneficial. Control of the thickness of the piezoelectric sheet.
  • the arrangement of the protrusions and the second groove is not limited to the arrangement of Figures 9A, 9B, and Figures 11, 12. It can also be that the bottom surface of the piezoelectric sheet is provided with protrusions, and the bottom surface of the first recess is provided with the first groove. Two grooves. That is to say, in the present invention, one of the bottom surface of the first groove and the bottom surface of the piezoelectric sheet has a plurality of protrusions, and the other has a second groove that matches the protrusions, and the protrusions are engaged with the second recesses. In the groove, the protrusion and the second groove are located in the non-device area of the composite substrate.
  • the material of the protrusions is a dielectric layer or polysilicon, and the protrusions are distributed on the cutting lane and have a strip structure.
  • the convex top surface is higher than or flush with the first surface, and the convex top surface is not covered by the piezoelectric sheet.
  • the problem of chipping when cutting the piezoelectric substrate can be solved.
  • the method part about the material, distribution, advantages and other related content of the bumps can be cited here.
  • the substrate further includes an acoustic reflection structure, and the acoustic reflection structure includes a cavity or a Bragg reflection layer. The sound reflection structure is used to reflect the longitudinal sound wave of the piezoelectric sheet body into the substrate or into the piezoelectric sheet to reduce the energy loss of the sound wave.
  • the fourth embodiment of the present invention also provides a method for manufacturing a surface acoustic wave resonator, including
  • a composite substrate is provided; a first interdigital transducer and a second interdigital transducer are formed on the top surface of the piezoelectric sheet.
  • the composite substrate is formed with an acoustic reflection structure, and the first interdigital transducer and the second interdigital transducer are formed above the area enclosed by the acoustic reflection structure.
  • the acoustic reflection structure is a first cavity, and forming the first cavity includes: forming a first cavity on the second surface of the substrate through an etching process, and the bottom of the first cavity exposes the piezoelectric sheet The second surface or the second bonding layer or the first bonding layer; providing a second substrate, bonding to the second surface of the substrate, and sealing the first cavity.
  • the method further includes: thinning the second surface of the base so that the thickness of the base is 0.5-5 microns; and the thickness of the second substrate is 300-500 microns.
  • the acoustic reflection structure is a Bragg reflection layer
  • forming the Bragg reflection layer includes: forming a second cavity on the second surface of the substrate through an etching process, and the bottom of the second cavity exposes the bottom surface of the piezoelectric sheet Or the first bonding layer or the first bonding layer; at least two sets of staggered first acoustic impedance layer and second acoustic impedance layer are formed at the bottom of the second cavity, and the hardness of the first acoustic impedance layer is higher than that of the second acoustic impedance layer.
  • the hardness of the acoustic impedance layer wherein the material of the first acoustic impedance layer is composed of metal including tungsten or a medium including silicon carbide and diamond, and the second acoustic impedance layer includes silicon oxide or silicon nitride.
  • the embodiment of the present invention also provides a surface acoustic wave resonator, including the above composite substrate.

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

一种用于制作声波谐振器复合基板及表声波谐振器及制造方法，其中复合基板的制造方法包括：提供基底（10），所述基底（10）包括相对的第一表面和第二表面；在所述第一表面形成向所述第二表面凹陷的第一凹槽（101）；提供压电片（20），所述压电片（20）与所述第一凹槽（101）的形状吻合，通过键合的方式将所述第一凹槽（101）的底面与所述压电片（20）结合；复合基板包括：基底，所述第一基底（10）包括相对的第一表面和第二表面；所述第一表面设有向所述第二表面凹陷的第一凹槽（101）；压电片（20），所述压电片（20）嵌入于所述第一凹槽（101）中，所述压电片（20）的顶面高于所述第一表面或者与所述第一表面齐平。

Description

用于制作声波谐振器复合基板及表声波谐振器及制造方法 技术领域
本发明涉及半导体制造领域，尤其涉及用于制作声波谐振器复合基板及表声波谐振器及制造方法。
 背景技术
随着移动通信技术的发展，移动数据传输量也迅速上升。因此，在频率资源有限以及应当使用尽可能少的移动通信设备的前提下，提高无线基站、微基站或直放站等无线功率发射设备的发射功率成了必须考虑的问题，同时也意味着对移动通信设备前端电路中滤波器功率的要求也越来越高。钽酸锂或铌酸锂被广泛用作表面声波(SAW)器件的压电材料。
表面声波是在压电片表面产生并传播且振幅随着深入压电片的深度增加而迅速减少的一种弹性波。表面声波滤波器的基本结构是在具有压电特性的基片材料抛光面上制作两个声电换能器－叉指换能器（Interdigital Transducer, IDT），分别用作发射换能器和接收换能器。发射换能器将RF信号转换为声表面波，在基片表面上传播，经过一定的延迟后，接收换能器将声信号转换为电信号输出，滤波过程是在电到声和声到电的压电转换中实现。
 技术问题
现有方案中，声波器件的压电片形成在基板上，压电片与基板结合强度不够，容易发生脱落；另外压电片由于横向形变，出现碎裂也是目前面临的问题。
因此，如何加强压电片与基板的结合强度，防止压电片横向形变导致的碎裂问题，是目前研究的课题。
 技术解决方案
本发明的目的在于提供一种用于制作声波谐振器复合基板及表声波谐振器及制造方法，解决压电片与基板结合时，结合强度不高导致压电片脱落，和压电片的横向变形导致的压电片碎裂问题。
为实现上述目的，本发明提供了一种复合基板的制造方法，包括：
提供基底，所述基底包括相对的第一表面和第二表面；
在所述第一表面形成向所述第二表面凹陷的第一凹槽；
提供压电片，所述压电片与所述第一凹槽的形状吻合，通过键合的方式将所述第一凹槽的底面与所述压电片结合。
本发明还提供了一种表声波谐振器的制造方法，利用上述的复合基板，所述制造方法包括：
提供所述复合基板；
在所述压电片的顶面形成第一叉指换能器和第二叉指换能器。
本发明还提供了一种复合基板，包括：
基底，所述基底包括相对的第一表面和第二表面；
所述第一表面设有向所述第二表面凹陷的第一凹槽；
压电片，所述压电片嵌入于所述第一凹槽中，所述压电片的顶面高于所述第一表面或者与所述第一表面齐平。
本发明还提供了一种表声波谐振器，包括上述的复合基板。
有益效果                                         
本发明的有益效果在于：将压电片嵌入第一凹槽中，第一凹槽的侧壁可以阻挡压电片的移动，防止压电片脱落，提高了结合强度；第一凹槽还可以限制压电片的横向形变，减少压电片变形引起的碎裂风险；另外，目前制造表面声波谐振器的通常做法是，将压电片键合在同等尺寸的硅晶圆上。硅晶圆的规格通常有12寸、8寸、6寸。如果硅晶圆的生产线为8寸的生产线，则采用8寸的压电片，对于6寸的压电片适用于6寸的生产线，也就是说8寸生产线无法使用6寸的压电片。本发明在压电片规格一定的情况下，可以适应不同规格生产线。
进一步的，利用二氧化硅层、硅、氮化硅作为键合层，可以直接在压电片或第一凹槽的底部通过沉积的方法形成，适用于半导体工艺，另外二氧化硅层还可以作为压电片的温度补偿层；
进一步的，在第一凹槽的底部形成应力缓冲层、应力补偿层，应力补偿层用于抵消键合层的应力，应力缓冲层解决应力补偿层与基底应力差异大的问题，应力缓冲层和应力补偿层还具有声反射功能，能够将声波反射回压电片内，减少声波能量损失；
进一步的，在第一凹槽的底部设置多个凸起，在压电片的底面设置与凸起相吻合的第二凹槽，一方面可以增加压电片与基底的结合强度；
另一方面凸起的高度略高于第一表面时，凸起可以作为研磨停止层，有利与对压电片体厚度的控制；
进一步的，压电材质比较脆，在切割时容易破裂，材料为介质层或硅的凸起分布在切割道上时，切割时避开了压电材料，而是切割介质材料比如氮化硅或硅材料，这样可以解决切割压电基板破裂的问题。
 附图说明
图1为本发明第一实施例的一种复合基板的制造方法的步骤流程图。
图2至图8是本发明第一实施例复合基板的制作方法各步骤对应的结构示意图。
图9A至图14是本发明第二实施例复合基板的制作方法不同步骤对应的结构示意图。
附图标记说明：
10-基底；101-第一凹槽；11-应力缓冲层；12-应力补偿层；13-第一键合层；20-压电片；21-第二键合层；30-凸起；31-第二凹槽。
 本发明的实施方式
以下结合附图和具体实施例对本发明作进一步详细说明。根据下面的说明和附图，本发明的优点和特征将更清楚，然而，需说明的是，本发明技术方案的构思可按照多种不同的形式实施，并不局限于在此阐述的特定实施例。附图均采用非常简化的形式且均使用非精准的比例，仅用以方便、明晰地辅助说明本发明实施例的目的。
应当明白，当元件或层被称为“在...上”、“与...相邻”、“连接到”或“耦合到”其它元件或层时，其可以直接地在其它元件或层上、与之相邻、连接或耦合到其它元件或层，或者可以存在居间的元件或层。相反，当元件被称为“直接在...上”、“与...直接相邻”、“直接连接到”或“直接耦合到”其它元件或层时，则不存在居间的元件或层。应当明白，尽管可使用术语第一、第二、第三等描述各种元件、部件、区、层和/或部分，这些元件、部件、区、层和/或部分不应当被这些术语限制。这些术语仅仅用来区分一个元件、部件、区、层或部分与另一个元件、部件、区、层或部分。因此，在不脱离本发明教导之下，下面讨论的第一元件、部件、区、层或部分可表示为第二元件、部件、区、层或部分。
空间关系术语例如“在...下”、“在...下面”、“下面的”、“在...之下”、“在...之上”、“上面的”等，在这里可为了方便描述而被使用从而描述图中所示的一个元件或特征与其它元件或特征的关系。应当明白，除了图中所示的取向以外，空间关系术语意图还包括使用和操作中的器件的不同取向。例如，如果附图中的器件翻转，然后，描述为“在其它元件下面”或“在其之下”或“在其下”元件或特征将取向为在其它元件或特征“上”。因此，示例性术语“在...下面”和“在...下”可包括上和下两个取向。器件可以另外地取向(旋转90度或其它取向)并且在此使用的空间描述语相应地被解释。
在此使用的术语的目的仅在于描述具体实施例并且不作为本发明的限制。在此使用时，单数形式的“一”、“一个”和“所述/该” 也意图包括复数形式，除非上下文清楚指出另外的方式。还应明白术语“组成”和/或“包括”，当在该说明书中使用时，确定所述特征、整数、步骤、操作、元件和/或部件的存在，但不排除一个或更多其它的特征、整数、步骤、操作、元件、部件和/或组的存在或添加。在此使用时，术语“和/或”包括相关所列项目的任何及所有组合。
如果本文的方法包括一系列步骤，且本文所呈现的这些步骤的顺序并非必须是可执行这些步骤的唯一顺序，且一些的步骤可被省略和/或一些本文未描述的其他步骤可被添加到该方法。若某附图中的构件与其他附图中的构件相同，虽然在所有附图中都可轻易辨认出这些构件，但为了使附图的说明更为清楚，本说明书不会将所有相同构件的标号标于每一图中。
本发明提供了一种复合基板的制造方法，图1为本发明的一种复合基板的制作方法的流程图，请参考图1，方法包括：S01：提供基底，基底包括相对的第一表面和第二表面；在第一表面形成向第二表面凹陷的第一凹槽。S02：提供压电片嵌入第一凹槽，压电片与第一凹槽的形状吻合，通过键合的方式将第一凹槽的底面与压电片结合。将压电片嵌入第一凹槽中，第一凹槽的侧壁可以阻挡压电片的移动，防止压电片脱落，提高了结合强度；第一凹槽还可以限制压电片的横向形变，减少压电片变形引起的碎裂风险；另外，目前制造表面声波谐振器的通常做法是，将压电片键合在同等尺寸的硅晶圆上。硅晶圆的规格通常有12寸、8寸、6寸。如果硅晶圆的生产线为8寸的生产线，则采用8寸的压电片，对于6寸的压电片适用于6寸的生产线，也就是说8寸生产线无法使用6寸的压电片。本发明在压电片规格一定的情况下，可以适应不同规格生产线。
第一实施例
下面请参考图2至图8对复合基板的制造方法进行阐述。图2至图8是本发明复合基板的制作方法第一实施例中各步骤对应的结构示意图。
参考图2和图3，执行步骤S01，提供基底10，基底10包括相对的第一表面和第二表面，在第一表面形成向第二表面凹陷的第一凹槽101。
基底10作为压电片的承载体，具有较低的热膨胀系数，并能适应于半导体加工工艺。本实施例中，基底为8寸的硅晶圆，厚度约600-800微米。在其他实施例中，基底10还可以是以下材料中的任意一种：蓝宝石、水晶、锗(Ge)、锗硅 (SiGe)、碳硅(SiC)、碳锗硅(SiGeC)、砷化铟(InAs)、砷化镓(GaAs)、磷化铟(InP)或者其它III/V化合物半导体。尺寸还可以是12寸、6寸、4寸等。
第一凹槽101用于容纳后期工艺中嵌入其中的压电片。形成的第一凹槽101的大小与压电片的尺寸相匹配，使压电片恰好放入第一凹槽101中。本实施例中形成的第一凹槽101为圆形，直径略大于为6寸，本实施例中，第一凹槽101的深度为0.5-10微米。第一凹槽101的深度由最终需要的压电片的设定厚度决定。本实施例中研磨后压电片的厚度设定为0.3-10微米。
本实施例中，通过刻蚀工艺在基底10的第一表面形成设定尺寸的第一凹槽101。具体的刻蚀步骤为：采用光刻工艺将需要刻蚀的凹槽位置光阻打开，再采用特殊的化学品湿法刻蚀，将基底10刻蚀出设定尺寸的凹槽101，由于是沿着晶格逐层刻蚀，最后形成的刻蚀底面非常平整，有利于后续的键合工艺，通过控制工艺时间可以精确控制刻蚀深度。刻蚀的侧面也能获得非常平整的表面，侧面倾角在45度到90度之间（指凹槽的侧壁与底面之间的夹角，凹槽的开口上大下小，期望可以接近90度）。为了保证压电片可以嵌入第一凹槽101中，凹槽底面的尺寸与压电片基本相等。
参考图4至图8，执行步骤S02，提供压电片20嵌入第一凹槽，压电片20与第一凹槽101的形状吻合，通过键合的方式将第一凹槽101的底面与压电片20结合。需要说明的是，此处的形状吻合并不意味着形状一模一样，需要保证压电片可以嵌入第一凹槽中，二者的形状大致相同即可。比如，如果第一凹槽的侧面倾角是90度，则二者的形状基本一样，如果侧面倾角非90度，则二者的形状不会相同，只是总体上形状大致吻合，保证压电片可以嵌入第一凹槽中，而且，不会有太多空隙出现。
参考图4，本实施例中，压电片20为6寸的压电晶圆，厚度为300-600微米左右，压电片20的材料包括：压电晶体或压电陶瓷，如：磷酸锂、碳酸锂、锆钛酸铅(PZT)、铌酸锂(LiNbO3)、石英 (Quartz)、铌酸钾(KNbO3)、钽酸锂(LiTaO3)、镓酸锂、锗酸锂、锗酸钛或铅锌榍石等具有纤锌矿型结晶结构的压电材料及它们的组合，当压电片20的材质为铌酸锂时，轴向为41°，基准边方向为64°时，压电片的传输损失较小。当压电片20的材质为钽酸锂时，轴向为42°，基准边方向为112°时，压电片的传输损失较小。本实施例中压电片20为单晶晶体。
在本实施例中，键合方式采用熔融键合，具体键合方法为：参考图5，在第一凹槽的底面和侧壁形成第一键合层13；参考图6，在压电片的底面（与第一凹槽相对的面）形成第二键合层21；参考图7，通过第一键合层13和第二键合层21将压电片20与基底10键合在一起。在第一凹槽101的底面和压电片20的底面分别形成键合层，通过双面键合层将压电片20嵌入在第一凹槽101中。
第一键合层13和第二键合层21的材质只要能实现键合功能即可，例如键合材料包括二氧化硅、多晶硅、氮化硅或金属。这些键合材料可以直接在压电片20或第一凹槽101的底部通过沉积的方法形成，适用于半导体工艺，另外二氧化硅层还可以作为压电片的温度补偿层。当第一键合层13为氧化硅材料，基底10为硅基底时，也可以采用热氧化方式形成第一键合层13。为满足键合要求第一键合层13、第二键合层21的厚度一般大于0.3微米，从工艺时间和成本考虑，第一键合层13、第二键合层21也不适合太厚，第一键合层13、第二键合层21的厚度一般介于0.3至1微米之间。
本实施例中，在形成第一键合层13时，第一键合层同时也形成在了第一凹槽外的基底10的上表面，此部分的第一键合层可以去除也可以保留，可以根据实际工艺需求而定。本实施例中，在基底以及压电片上均形成了键合层，但也可以是只在压电片上形成第二键合层，基底采用与该第二键合层容易键合的材质，比如硅。也可以是基底上形成第一键合层，该第一键合层的材质选用容易与压电片进行键合的材质。因此，本发明中熔融键合包括：在第一凹槽形成第一键合层和/或压电片的底面形成第二键合层，通过键合层键合基底与压电片，不限于图中实施例显示的双层键合。本发明中，基底与压电片键合的方式不限于以上的熔融键合，还可以为共价键键合或粘结键合。采用共价键键合方式时，需要对压电片的底面、第一凹槽的底面进行平整度处理使其表面达到要求的光滑程度，使压电片的底面、第一凹槽底面能够依靠二者之间的分子力而结合在一起。采用粘结键合时，通过在压电片20和/或第一凹槽101底面形成粘合剂，如环氧树脂胶，将压电片20粘贴在第一凹槽101的底部。另外本实施例中，在第一凹槽101的底面形成第一键合层13之前还包括形成应力缓冲层11和应力补偿层12。在第一凹槽的底部形成应力缓冲层、应力补偿层，应力补偿层用于抵消键合层的应力，应力缓冲层解决应力补偿层与基底应力差异大的问题。如果基底10与压电片20之间的应力不进行缓冲、抵消容易产生二者之间应力差异大，会产生基底10翘曲的现象。本实施例中，应力缓冲层11、应力补偿层12至少其中之一还为声波反射层，具有声波反射功能，当压电片中的声波传输至应力缓冲层11或应力补偿层12时，声波被反射回压电片内，减少了声波的能量损失。
其中，基底10的材质选用硅，应力缓冲层11的材质包括二氧化硅，应力补偿层12的材质包括氮化硅、碳化硅或氮化硼，或者金属材料，如钼、铝、钨或铊。其中，氮化硅、碳化硅或或氮化硼，或者钼、铝、钨、铊或钾材料的应力补偿层12同时还具有声波反射功能，可以充当声波反射层。应力缓冲层和应力补偿层的厚度可以介于0.08微米至1微米之间，具体的厚度值可以根据应力补偿的目标和声反射的要求来调整。本发明中，还可以不形成应力缓冲层、应力补偿层，在第一凹槽的底面和/或压电片的底面形成声波反射层。声波反射层为单层膜层或者多层膜层。声波反射层的材料至少包括碳化硅、氮化硅、钼、铝其中之一。也可以为既形成应力缓冲层、应力补偿层，也形成声波反射层。在进行键合之前，先在第一凹槽底面形成声波反射层，之后形成应力缓冲层、应力补偿层；或者，先在第一凹槽底面形成应力缓冲层、应力补偿层，之后形成声波反射层。
本实施例中，在形成以上键合层、应力缓冲层、应力补偿层之后还包括：分别对每层薄膜进行离子束修整工艺，使每层薄膜的表面光滑平坦，可以增加后续键合工艺中基底和压电片之间的键合强度。另外，为了提高结合强度还包括至少对第一键合层13或第二键合层21进行表面活化的步骤，表面活化的措施包括采用臭氧水处理、UV臭氧处理、等离子体处理、离子束处理中的任意一种。
参考图7，可以通过对准设备进行垂直光学对准，使压电片20嵌入第一凹槽101中，之后，将第一键合层13和第二键合层21进行键合。需要说明的是，本发明实施例中，压电片20嵌入在第一凹槽101中，第一凹槽101的侧壁对压电片20的移动具有限制作用，起到了加强结合强度的作用。在后期工艺中对压电片20进行减薄处理时，压电片20不会从基底10上剥离。并且，在复合基板上形成SAW谐振器等器件的过程中，压电片由于有凹槽的卡设以及侧面键合的双重保障，很难受各个工艺的影响比如高温工艺而从基底10上剥离。同时由于压电片20位于第一凹槽101内，第一凹槽101的侧壁限制了压电片20的横向形变，改善了压电片20横向产生形变引起的裂片问题（如受温度影响）。另外第一凹槽101的侧壁也形成有第一键合层13、应力缓冲层11、应力补偿层12，对压电片20的侧壁形成保护层和声波反射层，防止压电片碎裂和声波泄露。
参考图8，对压电片20的顶面进行减薄工艺，使压电片20达到设定厚度。本实施例中，减薄工艺包括以下步骤：
1、对压电片20的上表面进行机械研磨，将压电片20减薄至25-35微米。选用物理机械研磨设备，对压电片20的上表面进行粗磨，研磨精度要求不高，利用常规的研磨设备即可，可选具有较快研磨速度的设备，以减少研磨时间。2、采用化学机械粗磨，将压电片20减薄至4-6微米。采用化学机械抛光（CMP）对压电片20的上表面进行较为精细的研磨。3、采用化学机械抛光，将压电片20减薄至0.6-0.7微米。继续采用化学机械抛光（CMP）对压电片20的上表面进行更为精细的研磨。本实施例中，执行完上述3步研磨之后还包括：通过离子束修整工艺对压电片20的上表面进行修整，修整后的压电片20的表面粗糙指数（最厚的部分与最薄的部分高度差）低于10纳米。离子束的修整可以达到纳米级，不但可以实现对压电片20整体表面进行修整，也可以实现对局部高度进行调整。本实施例中，离子束修整工艺采用如下参数：离子束电流为25毫安到200毫安，整片晶圆的扫描时间为30秒到10分钟。
本实施例中，对压电片20的上表面进行修整后还包括：采用炉管或激光对压电片20进行退火处理，以修复压电片20的晶格损伤。炉管退火包括：将基底10放入高温炉内，如卧式炉、立式炉、快速热处理（RTP）。在 1100~1200度的温度下加热 2到5分钟。 激光退火包括：以0.8-015焦耳每平方厘米的脉冲激光作用于压电片30秒到600秒，使压电片20的局部温度加热至1100度到1300度，达到熔融态，重新结晶以修复损伤。退火处理后的压电片20具有更好的压电特性。两种退火处理的区别在于，第一种为对基底10和压电片20整体加热，第二种方式可以只对压电片表面进行加热。
本实施例中，当第一凹槽存在倾角，压电片与第一凹槽的侧面之间存在较大间隙时，可以在将基底与压电片键合之后，先沉积一层填充层，该填充层填充压电片与第一凹槽之间的间隙。该填充层可以只填充在该间隙内，也可以是填充层同时覆盖压电片顶面（与基底相背的面）以及第一凹槽之前的基底表面部分。在填充层同时覆盖压电片顶面（与基底相背的面）以及第一凹槽之前的基底表面部分时，对压电片进行减薄时，首先需要对压电片顶面的填充层进行减薄，之后减薄压电片至设定的厚度。第一凹槽之外基底上的填充层部分是否减薄，可以根据实际需求进行确定。或者，也可以是，先对压电片减薄至一定厚度后，再进行以上描述的形成填充层的工艺。其中，填充层可以采用介质层，比如二氧化硅，此时该二氧化硅可以作为温度补偿层。填充层也可以采用具有应力缓冲作用的介质层，缓解压电片与基底之间的应力。
第二实施例
本实施例与上一实施例的区别在于：在第一凹槽底面形成凸起，在压电片底面形成第二凹槽；或者，在第一凹槽底面形成第二凹槽，在压电片底面形成凸起；凸起与第二凹槽形状吻合，位于复合基板非器件区域，在压电片嵌入第一凹槽中时，第二凹槽和凸起卡合在一起。
具体的，参考图9A至图12，在形成第一键合层13之前，还包括：在第一凹槽101的底面形成多个凸起30；凸起30的高度可以低于第一表面，或者高于第一表面。参考图9A，凸起30的高度低于第一表面，参考图9B，凸起30的高度与第一表面相平。
参考的图11和图12，在形成第二键合层21之前或之后还包括：在压电片20与第一凹槽101相对的面形成与凸起30相吻合的多个第二凹槽31。在压电片20嵌入第一凹槽101中时，第二凹槽31和凸起30卡合在一起。其他步骤与第一实施例相同。参考图11，第二凹槽31的形状与凸起30的形状相匹配，尺寸略大于凸起30，以恰好可以容纳凸起为准。可以通过干法刻蚀工艺在压电片20的底面形成第二凹槽31。当需要在压电片20的底面形成第二键合层21时，第二凹槽31可以在形成第二键合层21之前形成，也可以在形成第二键合层21之后形成。参考图11，当在形成完第二键合层21之后形成第二凹槽31时，第二凹槽31的底部没有第二键合层。参考图12，当在形成第二键合层21之前形成第二凹槽31时，第二凹槽31的底部以及侧面（未示出）也形成了第二键合层21。当凸起的顶部形成有第一键合、应力缓冲层、应力补偿层或者第二凹槽的底面形成有第一键合层时，可以根据不同膜层的厚度及需要形成的压电片的厚度形成高度的凸起和所需深度的第二凹槽。
参考图9A、图9B，凸起30的形成方法包括:在刻蚀形成第一凹槽后，利用光刻工艺图形化第一凹槽底部形成凸起30，或者，在刻蚀形成第一凹槽后，在第一凹槽底面沉积介质层，刻蚀介质层形成凸起30。之后形成应力缓冲层、应力补偿层以及第一键合层。凸起30的作用增加了压电片与基底10的结合面积，从而可以增强二者之间的结合强度。参考图9B，当凸起30的高度与第一表面相平，凸起30的形成方法还可以包括:对基底10进行图形化，形成带有凸起30的第一凹槽101。此时凸起30不仅可以增加压电片与基底的结合强度。当凸起30的高度高于或与基底10的第一表面齐平时，凸起30可以作为研磨停止层。参考图9B以及图13，压电片顶面高于基底，压电片与基底键合后，还包括，对压电片20进行研磨减薄工艺（参考图14）；凸起30形成在第一凹槽底面，凸起30作为研磨减薄工艺的研磨停止层，或者，凸起30顶面形成有研磨停止层。凸起30作为研磨停止层分两种情况，第一种情况，凸起的材质与基底的材质并不同，通过沉积工艺形成介质层比如氮化硅后，对介质层进行光刻工艺形成凸起，此时凸起本身可以作为研磨停止层。第二种情况，由于在形成凸起之后，还形成应力缓冲层以及应力补偿层，位于凸起顶面的应力缓冲层或者应力补偿层可以作为研磨停止层。比如，应力补偿层可以选择氮化硅，该应力补偿层也可以作为研磨停止层。
参考图14，本实施例中，采用第二种情况，应力补偿层选择氮化硅，可以作为对压电片进行研磨减薄的停止层。参考图10为凸起的其中一种排列方式图，凸起30排列成网格形式，凸起30形成在第一凹槽底面，凸起30的材质为介质层或者硅，凸起分布在切割道上，为条状结构。压电片本身材质比较脆，在切割时容易破裂，该实施例中，在切割道上分布材料为介质层或硅材料的凸起，切割时避开了压电材料，而是切割介质材料比如氮化硅，这样可以解决切割压电基板破裂的问题。本实施例中，凸起顶面高于或与第一表面齐平，且凸起顶面未被压电片遮盖。这样可以完全避免切割复合基板时，切割压电材料。当然，本发明中，凸起的分布形式不限于图10所示的形式，也可以是点状分散分布，起加强结合强度的作用。本发明中，也可以是在第一凹槽底面形成凸起之前，在第一凹槽中形成应力缓冲层、应力补偿层，和/或声波反射层。
第二实施例与第一实施例的差异主要在于是否形成凸起以及第二凹槽，其他步骤与第一实施例同，在此不进行赘述。
第三实施例
本发明第三实施例还提供了一种复合基板，图8为本发明一实施例的一种复合基板的结构示意图，请参考图8，复合基板包括：基底10，基底10包括相对的第一表面和第二表面；第一表面设有向第二表面凹陷的第一凹槽；压电片20，压电片20嵌入第一凹槽中与基底10键合在一起，压电片20的顶面高于第一表面或者与复合基板表面为平面。本实施中，复合基板表面为平面。键合方式包括共价键键合、粘结键合、熔融键合其中之一。具体键合方式的描述可以参见方法部分相关内容。
继续参考8，本实施例中，第一凹槽的底部、侧壁形成有第一键合层， 压电片体与第一凹槽相对的表面设有第二键合层。本实施例中，在第一键合层和第一凹槽的底部之间还包括：应力缓冲层和应力补偿层，其中应力补偿层位于应力缓冲层与第一键合层之间。第一实施例方法部分关于键合层、应力缓冲层、应力补偿层的材料、厚度以及分布位置、所起的作用可以援引于此。在此不做赘述。本发明中，熔融键合的方式不限于上段描述，只要满足以下要求即可：第一键合层，设置于第一凹槽的底部、侧壁；和/或第二键合层，设置于压电片体与第一凹槽相对的表面。本发明其他实施例中，压电片与基底之间具有声波反射层，声波反射层可以位于与应力缓冲层、应力补偿层上表面或下表面或者二者之间，或者，述基底之间具有依次位于第一凹槽的应力缓冲层和应力补偿层，应力缓冲层、应力补偿层至少其中之一为声波反射层。方法部分相关内容描述，可以援引于此。
参考的图9A、图9B，在另一个实施例中，第一凹槽101内还包括多个凸起30；参考图11、图12，压电片20的底面包括多个与凸起30相吻合的第二凹槽31；参考图13、图14，凸起30卡合在第二凹槽中。设置凸起与第二凹槽，一方面可以增加压电片与基底的结合强度，另一方面当对压电片的上顶面进行减薄工艺时，凸起作为研磨停止层，有利与对压电片体厚度的控制。本实施例中，凸起与第二凹槽的设置方式不限于图9A、图9B以及图11、图12设置的方式，还可以是压电片底面设置凸起，第一凹槽底面设置第二凹槽。也就是说，本发明中第一凹槽底面、压电片底面中，其中之一具有多个凸起，另一具有与凸起相吻合的第二凹槽，凸起卡合在第二凹槽中，凸起与第二凹槽位于复合基板非器件区域。其中，当凸起形成在第一凹槽底面，凸起的材质为介质层或者多晶硅，凸起分布在切割道上，为条状结构。凸起顶面高于或与第一表面齐平，且凸起顶面未被压电片遮盖，此种情况可以解决切割压电基板时碎裂的问题。方法部分关于凸起的材质、分布、优点等相关内容可以援引于此。在另一个实施例中，基底还包括声反射结构， 声反射结构包括空腔或布拉格反射层。声反射结构用于将压电片体传入基底的纵向声波反射或压电片内，减少声波的能量损失。
第四实施例
本发明第四实施例还提供了一种表声波谐振器的制造方法，包括
提供复合基板；在压电片的顶面形成第一叉指换能器和第二叉指换能器。在一个实施例中，复合基板形成有声反射结构，第一叉指换能器和第二叉指换能器形成于声反射结构围成的区域上方。在一个实施例中，声反射结构为第一空腔，形成第一空腔包括：在基底的第二表面通过刻蚀工艺形成第一空腔，第一空腔的底部暴露出压电片的第二表面或第二键合层或第一键合层；提供第二基板，键合于基底的第二表面，密封第一空腔。形成第一空腔之前还包括：对基底的第二表面进行减薄，使基底的厚度为0.5-5微米；第二基板的厚度为300-500微米。在另一个实施例中，声反射结构为布拉格反射层，形成布拉格反射层包括：在基底的第二表面通过刻蚀工艺形成第二空腔，第二空腔的底部暴露出压电片的底面或第一键合层或第一键合层；在第二空腔的底部形成至少两组交错的第一声阻抗层和第二声阻抗层，第一声波阻抗层的硬度高于第二声波阻抗层的硬度，其中第一声波阻抗层的材料由包括钨在内的金属或包括碳化硅、金刚石在内的介质构成，第二声阻抗层包括氧化硅或氮化硅。
本发明实施例还提供一种表声波谐振器，包括以上的复合基板。
需要说明的是，本说明书中的各个实施例均采用相关的方式描述，各个实施例之间相同相似的部分互相参见即可，每个实施例重点说明的都是与其他实施例的不同之处。尤其，对于结构实施例而言，由于其基本相似于方法实施例，所以描述的比较简单，相关之处参见方法实施例的部分说明即可。
上述描述仅是对本发明较佳实施例的描述，并非对本发明范围的任何限定，本发明领域的普通技术人员根据上述揭示内容做的任何变更、修饰，均属于权利要求书的保护范围。                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

Claims (40)

  1. 一种用于制作声波谐振器复合基板的制造方法，其特征在于，包括：
    提供基底，所述基底包括相对的第一表面和第二表面；
    在所述第一表面形成向述第二表面凹陷的第一凹槽；
    提供压电片嵌入所述第一凹槽，所述压电片与所述第一凹槽的形状吻合，通过键合的方式将所述第一凹槽的底面与所述压电片结合。
  2. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述键合方式包括共价键键合、粘结键合、熔融键合其中之一。
  3. 根据权利要求2所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述粘结键合包括：在所述第一凹槽和/或所述压电片的底面形成粘合剂，利用所述粘合剂键合所述基底与所述压电片；
    所述熔融键合包括：在所述第一凹槽形成第一键合层和/或所述压电片的底面形成第二键合层，通过所述键合层键合所述基底与所述压电片。
  4. 根据权利要求3所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述第一键合层和/或第二键合层的材料包括：氧化硅、氮化硅、多晶硅或金属。
  5. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，在进行所述键合之前，还包括：在所述第一凹槽的底面和/或所述压电片的底面形成声波反射层。
  6. 根据权利要求5所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述声波反射层为单层膜层或者多层膜层。
  7. 根据权利要求5所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述声波反射层的材料至少包括碳化硅、氮化硅、氮化硼、钼、铝、钨、铊、钾其中之一。
  8. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，在所述键合之前，还包括：在所述第一凹槽底面形成应力缓冲层。
  9. 根据权利要求8所述的用于制作声波谐振器复合基板的制造方法，其特征在于，还包括：在所述应力缓冲层上形成应力补偿层。
  10. 根据权利要求9所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述基底为硅基底，所述应力缓冲层为氧化硅，所述应力补偿层为氮化硅。
  11. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，在进行所述键合之前，先在所述第一凹槽底面形成声波反射层，之后形成应力缓冲层、应力补偿层；
    或者，先在所述第一凹槽底面形成应力缓冲层、应力补偿层，之后形成声波反射层；
    或者，在所述第一凹槽形成应力缓冲层、应力补偿层，所述应力缓冲层、应力补偿层至少其中一层作为声波反射层。
  12. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，还包括：在所述第一凹槽底面形成凸起，在所述压电片底面形成第二凹槽；或者，在所述第一凹槽底面形成第二凹槽，在所述压电片底面形成凸起；
    所述凸起与所述第二凹槽形状吻合，位于复合基板非器件区域，在所述压电片嵌入所述第一凹槽中时，所述第二凹槽和所述凸起卡合在一起。
  13. 根据权利要求12所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述凸起的形成方法包括：图形化所述第一凹槽底面或所述压电片底面形成所述凸起；
    或者，在所述第一凹槽底面或者所述压电片底面形成介质层或多晶硅层，刻蚀所述介质层或多晶硅层形成所述凸起。
  14. 根据权利要求12所述的用于制作声波谐振器复合基板的制造方法，其特征在于，
    所述凸起形成在所述第一凹槽底面，在形成所述凸起之前或之后，在所述第一凹槽中形成应力缓冲层、应力补偿层，和/或声波反射层。
  15. 根据权利要求12所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述压电片顶面高于所述基底，所述压电片与所述基底键合后，还包括，对所述压电片进行研磨减薄工艺；
    所述凸起形成在所述第一凹槽底面，所述凸起作为所述研磨减薄工艺的研磨停止层，或者，所述凸起顶面形成有研磨停止层。
  16. 根据权利要求12所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述凸起形成在所述第一凹槽底面，所述凸起的材质为介质层或者多晶硅，所述凸起分布在切割道上，为条状结构。
  17. 根据权利要求16所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述凸起顶面高于或与所述第一表面齐平，且所述凸起顶面未被所述压电片遮盖。
  18. 根据权利要求9所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述应力缓冲层、应力补偿层的厚度依次为：0.08-1微米、0.08-1微米。
  19. 根据权利要求4所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述第一键合层或所述第二键合层的厚度为0.3-1微米。
  20. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，将所述压电片与所述第一凹槽结合后，所述压电片的顶面与所述第一表面齐平或高于所述第一表面。
  21. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述压电片的顶面高于所述第一表面，还包括对所述压电片的上表面进行减薄至与所述复合基板的上表面为平面，所述减薄工艺包括以下步骤：
    对所述压电片的顶面进行机械研磨，将所述压电片减薄至25-35微米；
    采用化学机械粗磨，将所述压电片减薄至4-6微米；
    采用化学机械抛光，将所述压电片减薄至0.6-0.7微米；
    通过离子束修整工艺对所述压电片的上表面进行修整，修整后的所述压电片的表面厚度均匀性小于2%。
  22. 根据权利要求21所述的用于制作声波谐振器复合基板的制造方法，其特征在于，对所述压电片的顶面进行离子束修整后还包括：
    采用炉管或激光对所述压电片进行退火处理，以修复所述压电片的晶格损伤。
  23. 根据权利要求1所述的用于制作声波谐振器复合基板的制造方法，其特征在于，所述压电片的材料包括钽酸锂或铌酸锂，所述压电片为单晶。
  24. 一种表声波谐振器的制造方法，利用权利要求1-23任一项所述的复合基板，其特征在于，所述制造方法包括：
    提供所述复合基板；
    在所述压电片的顶面形成第一叉指换能器和第二叉指换能器。
  25. 25、一种用于制作声波谐振器复合基板，其特征在于，包括：
    基底，所述基底包括相对的第一表面和第二表面；
    所述第一表面设有向所述第二表面凹陷的第一凹槽；
    压电片，所述压电片嵌入于所述第一凹槽中与所述基底键合在一起，所述压电片的顶面高于所述第一表面或者与所述复合基板表面为平面。
  26. 根据权利要求25所述的用于制作声波谐振器复合基板，其特征在于，所述键合方式包括共价键键合、粘结键合、熔融键合其中之一。
  27. 根据权利要求25所述的用于制作声波谐振器复合基板，其特征在于，所述键合方式为熔融键合，所述复合基板还包括：第一键合层，设置于所述第一凹槽的底部、侧壁；
    和/或第二键合层，设置于所述压电片体与所述第一凹槽相对的表面。
  28. 根据权利要求27所述的用于制作声波谐振器复合基板，其特征在于，所述第一键合层和/或第二键合层的材料包括：氧化硅、氮化硅、多晶硅或金属。
  29. 根据权利要求25所述的用于制作声波谐振器复合基板，其特征在于，所述压电片与所述基底之间具有依次位于所述第一凹槽的应力缓冲层和应力补偿层；和/或，所述压电片与所述基底之间具有声波反射层。
  30. 根据权利要求25所述的用于制作声波谐振器复合基板，其特征在于，所述压电片与所述基底之间具有依次位于所述第一凹槽的应力缓冲层和应力补偿层，所述应力缓冲层、应力补偿层至少其中之一为声波反射层。
  31. 根据权利要求29或30所述的用于制作声波谐振器复合基板，其特征在于，所述声波反射层的材料至少包括碳化硅、氮化硅、氮化硼、钼、铝、钨、铊、钾其中之一；
    所述基底为硅基底，所述应力缓冲层为氧化硅，所述应力补偿层为氮化硅或碳化硅。
  32. 根据权利要求25所述的用于制作声波谐振器复合基板，其特征在于，所述第一凹槽底面、所述压电片底面中，其中之一具有多个凸起，另一具有与所述凸起相吻合的第二凹槽，所述凸起卡合在所述第二凹槽中，所述凸起与所述第二凹槽位于复合基板非器件区域。
  33. 根据权利要求32所述的用于制作声波谐振器复合基板，其特征在于，所述凸起形成在所述第一凹槽底面，所述凸起的材质为介质层或者多晶硅，所述凸起分布在切割道上，为条状结构。
  34. 根据权利要求33所述的用于制作声波谐振器复合基板，其特征在于，所述凸起顶面高于或与所述第一表面齐平，且所述凸起顶面未被所述压电片遮盖。
  35. 根据权利要求27所述的用于制作声波谐振器复合基板，其特征在于，所述第一键合层或所述第二键合层的厚度大于0.3微米。
  36. 根据权利要求30或31所述的用于制作声波谐振器复合基板，其特征在于，所述应力补偿层的厚度为0.08-1微米；所述应力缓冲层的厚度为0.08-1微米。
  37. 根据权利要求25所述的用于制作声波谐振器复合基板，其特征在于，所述压电片的材料包括钽酸锂或铌酸锂，所述压电片为单晶。
  38. 根据权利要求25所述的用于制作声波谐振器复合基板，其特征在于，所述基底包括声反射结构。
  39. 根据权利要求38所述的用于制作声波谐振器复合基板，其特征在于，所述声反射结构包括空腔或布拉格反射层。
  40. 一种表声波谐振器，其特征在于，包括权利要求25-39任一项所述的用于制作声波谐振器复合基板。
PCT/CN2020/099638 2020-01-08 2020-07-01 用于制作声波谐振器复合基板及表声波谐振器及制造方法 WO2021139117A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2021527083A JP7291219B2 (ja) 2020-01-08 2020-07-01 音響波共振器を作製するための複合基板、および表面音響波共振器および作製方法
US17/618,690 US20220247375A1 (en) 2020-01-08 2020-07-01 Composite substrate for manufacturing acoustic wave resonator and surface acoustic wave resonator, and manufacturing method thereof

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010018484.8 2020-01-08
CN202010018484.8A CN113098431B (zh) 2020-01-08 2020-01-08 用于制作声波谐振器复合基板及表声波谐振器及制造方法

Publications (1)

Publication Number Publication Date
WO2021139117A1 true WO2021139117A1 (zh) 2021-07-15

Family

ID=76663303

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/099638 WO2021139117A1 (zh) 2020-01-08 2020-07-01 用于制作声波谐振器复合基板及表声波谐振器及制造方法

Country Status (4)

Country Link
US (1) US20220247375A1 (zh)
JP (1) JP7291219B2 (zh)
CN (1) CN113098431B (zh)
WO (1) WO2021139117A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113972900B (zh) * 2021-12-22 2022-05-13 深圳新声半导体有限公司 一种声表面滤波器的键合方法及其键合结构

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102034799A (zh) * 2009-10-07 2011-04-27 精材科技股份有限公司 芯片封装体及其制造方法
CN202737825U (zh) * 2012-07-11 2013-02-13 台州欧文电子科技有限公司 一种sr580t75型低损耗声表面波谐振器
US20140141546A1 (en) * 2012-11-21 2014-05-22 Samsung Electronics Co., Ltd. Method of fabricating optoelectronic integrated circuit substrate
CN103840075A (zh) * 2012-11-27 2014-06-04 中国科学院微电子研究所 微型压电振动能量收集器及其制造方法
CN105958956A (zh) * 2016-04-26 2016-09-21 电子科技大学 一种新型薄膜体声波谐振器及其制备方法
CN108494380A (zh) * 2018-03-16 2018-09-04 无锡市好达电子有限公司 声表面波材料及其制作方法
CN109273586A (zh) * 2018-08-17 2019-01-25 福建晶安光电有限公司 一种压电晶片及其制作方法
CN110011631A (zh) * 2019-03-13 2019-07-12 电子科技大学 具有应力缓冲层的空腔型体声波谐振器及其制备方法

Family Cites Families (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5263327U (zh) * 1975-11-05 1977-05-10
JPH07168662A (ja) * 1993-12-14 1995-07-04 Fujitsu Ltd 超音波座標入力装置
US6201457B1 (en) * 1998-11-18 2001-03-13 Cts Corporation Notch filter incorporating saw devices and a delay line
JP4446730B2 (ja) * 2003-12-24 2010-04-07 京セラ株式会社 圧電共振子及びフィルタ並びに複合基板
JP2006340007A (ja) * 2005-06-01 2006-12-14 Kyocera Corp 薄膜バルク音響波共振子およびフィルタならびに通信装置
WO2007129496A1 (ja) * 2006-04-07 2007-11-15 Murata Manufacturing Co., Ltd. 電子部品およびその製造方法
DE102007037502B4 (de) * 2007-08-08 2014-04-03 Epcos Ag Bauelement mit reduziertem Temperaturgang
JP2009246583A (ja) * 2008-03-31 2009-10-22 Daishinku Corp 圧電振動デバイス
JP2010050736A (ja) * 2008-08-21 2010-03-04 Panasonic Electric Works Co Ltd 共振装置およびその製造方法
WO2013031748A1 (ja) * 2011-09-01 2013-03-07 株式会社村田製作所 圧電バルク波装置及びその製造方法
JP2013214954A (ja) * 2012-03-07 2013-10-17 Taiyo Yuden Co Ltd 共振子、周波数フィルタ、デュプレクサ、電子機器及び共振子の製造方法
JP3187231U (ja) * 2013-09-05 2013-11-14 日本碍子株式会社 複合基板
US9455681B2 (en) * 2014-02-27 2016-09-27 Avago Technologies General Ip (Singapore) Pte. Ltd. Bulk acoustic wave resonator having doped piezoelectric layer
US10389332B2 (en) * 2014-12-17 2019-08-20 Qorvo Us, Inc. Plate wave devices with wave confinement structures and fabrication methods
WO2016147986A1 (ja) * 2015-03-16 2016-09-22 株式会社村田製作所 弾性波装置及びその製造方法
WO2017068828A1 (ja) * 2015-10-23 2017-04-27 株式会社村田製作所 弾性波装置
PL3377886T3 (pl) * 2015-11-20 2021-01-25 Qorvo Us, Inc. Rezonator akustyczny ze zmniejszonym mechanicznym zaciskaniem obszaru aktywnego dla poprawionej odpowiedzi w postaci modu ścinającego
DE102016100925B4 (de) * 2016-01-20 2018-05-30 Snaptrack, Inc. Filterschaltung
JP2017224890A (ja) * 2016-06-13 2017-12-21 株式会社村田製作所 弾性波装置
JP6683255B2 (ja) * 2016-07-01 2020-04-15 株式会社村田製作所 弾性波装置及び電子部品
JP2019165425A (ja) * 2017-08-24 2019-09-26 住友金属鉱山株式会社 表面弾性波素子用複合基板とその製造方法
JP7037336B2 (ja) * 2017-11-16 2022-03-16 太陽誘電株式会社 弾性波デバイスおよびその製造方法、フィルタ並びにマルチプレクサ
US10938372B2 (en) * 2018-05-17 2021-03-02 Taiyo Yuden Co., Ltd. Acoustic wave resonator, acoustic wave device, and filter
CN110085736A (zh) * 2019-04-28 2019-08-02 厦门市三安集成电路有限公司 一种薄膜单晶压电材料复合基板的制造方法和应用

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102034799A (zh) * 2009-10-07 2011-04-27 精材科技股份有限公司 芯片封装体及其制造方法
CN202737825U (zh) * 2012-07-11 2013-02-13 台州欧文电子科技有限公司 一种sr580t75型低损耗声表面波谐振器
US20140141546A1 (en) * 2012-11-21 2014-05-22 Samsung Electronics Co., Ltd. Method of fabricating optoelectronic integrated circuit substrate
CN103840075A (zh) * 2012-11-27 2014-06-04 中国科学院微电子研究所 微型压电振动能量收集器及其制造方法
CN105958956A (zh) * 2016-04-26 2016-09-21 电子科技大学 一种新型薄膜体声波谐振器及其制备方法
CN108494380A (zh) * 2018-03-16 2018-09-04 无锡市好达电子有限公司 声表面波材料及其制作方法
CN109273586A (zh) * 2018-08-17 2019-01-25 福建晶安光电有限公司 一种压电晶片及其制作方法
CN110011631A (zh) * 2019-03-13 2019-07-12 电子科技大学 具有应力缓冲层的空腔型体声波谐振器及其制备方法

Also Published As

Publication number Publication date
JP7291219B2 (ja) 2023-06-14
CN113098431A (zh) 2021-07-09
CN113098431B (zh) 2023-09-08
US20220247375A1 (en) 2022-08-04
JP2022519148A (ja) 2022-03-22

Similar Documents

Publication Publication Date Title
US20230253383A1 (en) Techniques for joining dissimilar materials in microelectronics
US20230253949A1 (en) Surface acoustic wave device and associated production method
JP7255910B2 (ja) 共振器及びその形成方法
JP4368930B2 (ja) 弾性表面波素子
US7208859B2 (en) Bonded substrate, surface acoustic wave chip, and surface acoustic wave device
US20200331750A1 (en) Methods of fabricating semiconductor structures including cavities filled with a sacrificial material
WO2021012923A1 (zh) 薄膜体声波谐振器及其制作方法
KR102301378B1 (ko) 헤테로 구조체 및 제조 방법
US20030199105A1 (en) Method for making piezoelectric resonator and surface acoustic wave device using hydrogen implant layer splitting
JP7130841B2 (ja) 薄膜バルク音響波共振器及びその製造方法
US20240040930A1 (en) Hybrid structure for a surface acoustic wave device
JP7081041B2 (ja) 薄膜バルク音響波共振器とその製造方法、フィルタ、および無線周波数通信システム
US11870411B2 (en) Method for manufacturing a substrate for a radiofrequency device
JP4368499B2 (ja) 弾性表面波素子の製造方法およびそれを用いた弾性表面波デバイスの製造方法
WO2021139117A1 (zh) 用于制作声波谐振器复合基板及表声波谐振器及制造方法
JP2023143949A (ja) 高周波フィルタ用の基板を製造するためのプロセス
CN111510093B (zh) 一种用于制作体声波器件的压电薄膜体及其制备方法
US20240213944A1 (en) Method for manufacturing a substrate for a radiofrequency filter
CN111755594B (zh) 一种超薄压电单晶箔的制作方法及其应用
WO2021189964A1 (zh) 一种薄膜体声波谐振器及其制造方法
JPH04243132A (ja) 半導体基板およびその製造方法

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2021527083

Country of ref document: JP

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20911469

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20911469

Country of ref document: EP

Kind code of ref document: A1