Bulk acoustic wave device and manufacturing method thereof
By setting an etch stop layer on the substrate of the bulk acoustic wave device and removing the material layer of the receiving device area, transmitting devices and receiving devices of different frequencies are prepared on the same substrate, solving the problems of complex process and high cost in the prior art, and achieving precise control of film layer thickness and frequency stability.
Patent Information
- Application Number
- CN202111676881.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-31
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2041-12-31
Smart Images
Figure CN114465588B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of bulk acoustic wave technology, and in particular to a bulk acoustic wave device and a manufacturing method thereof. Background Art
[0002] In BAW devices, the transmitting and receiving components operate at different frequencies. Furthermore, the frequency is related to the thickness of the device's film layers; different frequencies require different film thicknesses. Therefore, existing BAW devices typically manufacture the transmitting and receiving components on separate wafers, then package them together.
[0003] However, the process of this preparation method is relatively complicated and the cost is relatively high. Summary of the Invention
[0004] Based on this, embodiments of the present application provide a bulk acoustic wave device and a manufacturing method thereof that can reduce costs.
[0005] A method for manufacturing a bulk acoustic wave device, comprising:
[0006] Providing a substrate, wherein the substrate has a transmitting device area and a receiving device area;
[0007] forming a first functional layer on the substrate, wherein the first functional layer at least covers the emitting device region and the receiving device region;
[0008] forming an etch stop layer on the first functional layer;
[0009] forming a second functional material layer on the etch stop layer;
[0010] Based on the etching stop layer, the second functional material layer on the receiving device area is removed, and the remaining second functional material layer constitutes a second functional layer. The second functional layer and the first functional layer together form a functional structure layer. The piezoelectric layer or bottom electrode layer or top electrode layer of the bulk acoustic wave device includes this functional structure layer.
[0011] In one embodiment, the etch stop layer is a temperature compensation layer.
[0012] In one embodiment, the material of the temperature compensation layer is silicon dioxide or fluorine-doped silicon dioxide.
[0013] In one embodiment, the piezoelectric layer includes the functional structure layer,
[0014] Before forming the first functional layer on the substrate, the method further includes:
[0015] forming a patterned bottom electrode layer on the substrate;
[0016] The forming of the first functional layer on the substrate comprises:
[0017] forming a first functional layer on the bottom electrode layer and the substrate;
[0018] After removing the second functional material layer on the receiving device area based on the etch stop layer, the method further includes:
[0019] A patterned top electrode layer is formed on the etch stop layer and the second functional layer.
[0020] In one embodiment, the bottom electrode layer includes the functional structure layer,
[0021] After removing the second functional material layer on the receiving device area based on the etch stop layer, the method further includes:
[0022] forming a piezoelectric layer on the second functional layer, the etch stop layer, and the substrate;
[0023] A patterned top electrode layer is formed on the piezoelectric layer.
[0024] In one embodiment, the top electrode layer includes the functional structure layer,
[0025] Before forming the first functional layer on the substrate, the method further includes:
[0026] forming a patterned bottom electrode layer on the substrate;
[0027] forming a piezoelectric layer on the bottom electrode layer and the substrate;
[0028] The forming of the first functional layer on the substrate comprises:
[0029] A first functional layer is formed on the piezoelectric layer.
[0030] In one embodiment, the etch stop layer partially covers the first functional layer corresponding to the emission device region, and the first functional layer and the second functional layer corresponding to the emission device region are in contact with each other.
[0031] A bulk acoustic wave device comprising:
[0032] A substrate having a transmitting device area and a receiving device area;
[0033] A first functional layer is formed on the substrate and covers at least the emitting device area and the receiving device area;
[0034] an etch stop layer formed on the first functional layer;
[0035] A second functional layer is formed outside the receiving device area and is located on the etch stop layer. The second functional layer and the first functional layer together form a functional structure layer. The piezoelectric layer, bottom electrode layer or top electrode layer of the bulk acoustic wave device includes the functional structure layer.
[0036] In one embodiment, the etch stop layer is a temperature compensation layer.
[0037] In one embodiment,
[0038] The piezoelectric layer includes the functional structure layer, and the bulk acoustic wave device further includes:
[0039] A patterned bottom electrode layer is formed on the substrate, and the first functional layer is formed on the bottom electrode layer and the substrate;
[0040] a patterned top electrode layer formed on the etch stop layer and the second functional layer;
[0041] Alternatively, the bottom electrode layer includes the functional structure layer, and the bulk acoustic wave device further includes:
[0042] a piezoelectric layer formed on the second functional layer, the etch stop layer and the substrate;
[0043] a patterned top electrode layer formed on the piezoelectric layer;
[0044] Alternatively, the top electrode layer includes the functional structure layer, and the bulk acoustic wave device further includes:
[0045] a patterned bottom electrode layer formed on the substrate;
[0046] A piezoelectric layer is formed on the bottom electrode layer, and the first functional layer is formed on the piezoelectric layer.
[0047] In the above-mentioned bulk acoustic wave device and its manufacturing method, since the second functional material layer on the receiving device area is removed, the functional structure layer corresponding to the receiving device area lacks the second functional layer relative to the functional structure layer corresponding to the transmitting device area, thereby effectively achieving different thicknesses of the piezoelectric layer, or the bottom electrode layer or the top electrode layer in the receiving device area and the transmitting device area.
[0048] At the same time, the provision of the etch-stop layer also prevents the first functional layer from being damaged during the etching process of the second functional material layer, thereby enabling precise control of the thickness of the functional structure layer, and thus the thickness of each film layer of the receiving device and the transmitting device. Therefore, this embodiment can effectively realize the simultaneous formation of the receiving device and the transmitting device on the same substrate.
[0049] In the application, the various membrane layers (piezoelectric layer, bottom electrode layer, top electrode layer) of the transmitting device and the receiving device can be formed using the same process steps, thereby effectively reducing the process complexity and effectively reducing the process cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0051] Figure 1 is a flow chart of a method for manufacturing a bulk acoustic wave device provided in one embodiment;
[0052] Figure 2a-2f A schematic structural diagram of a bulk acoustic wave device during the manufacturing process provided in one embodiment;
[0053] Figure 3a-3f A schematic structural diagram of a bulk acoustic wave device during the manufacturing process provided in another embodiment;
[0054] Figure 4a-4f A schematic structural diagram of a bulk acoustic wave device during the manufacturing process provided in yet another embodiment; DETAILED DESCRIPTION
[0055] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.
[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.
[0057] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to, or coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to, or directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types, and / or portions, these elements, components, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, doping type, or portion from another element, component, region, layer, doping type, or portion. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion.
[0058] Spatially relative terms such as "below," "beneath," "beneath," "above," "above," and the like may be used herein to describe the relationship of one element or feature to other elements or features as depicted in the figures. It should be understood that the spatially relative terms encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element or feature described as "below," "beneath," or "beneath" another element would then be oriented "above" the other element or feature.
[0059] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.
[0060] In one embodiment, see Figure 1 , provides a method for manufacturing a bulk acoustic wave device, comprising the following steps:
[0061] Step S10, see Figure 2a or Figure 3a or Figure 4a , providing a substrate 100, the substrate 100 having a transmitting device area and a receiving device area;
[0062] Step S20, see Figure 2bor Figure 3b or Figure 4c , forming a first functional layer 101 on the substrate 100, wherein the first functional layer 101 at least covers the emitting device area and the receiving device area;
[0063] Step S30, see Figure 2b or Figure 3b or Figure 4c , forming an etch stop layer 200 on the first functional layer 101;
[0064] Step S40, see Figure 2b or Figure 3c or Figure 4d , forming a second functional material layer 1021 on the etch stop layer 200;
[0065] Step S50, see Figure 2c or Figure 3d or Figure 4e Based on the etch stop layer 200 , the second functional material layer 1021 on the receiving device area is removed, and the remaining second functional material layer 1021 constitutes the second functional layer 102 , and the second functional layer 102 and the first functional layer 102 together form a functional structure layer.
[0066] In step S10, refer to Figure 2a or Figure 3a or Figure 4a The substrate 100 may include a wafer 110 and a sacrificial layer 120 .
[0067] Specifically, a wafer 110 may be provided first. The wafer 110 may include, but is not limited to, a silicon wafer. The wafer 110 may be divided into a transmitting device area and a receiving device area.
[0068] Then, two cavities spaced apart from each other are formed in the wafer 110 through processes such as photolithography and etching. Then, a sacrificial layer 120 is filled in the cavities to form the substrate 100.
[0069] The two cavities are used to form a transmitting device and a receiving device respectively.
[0070] Therefore, the area where the two cavities are located can be defined as the emitting device area and the receiving device area, or part of the area within the area where the two cavities are located can be defined as the emitting device area and the receiving device area.
[0071] In step S20, refer to Figure 2b or Figure 3b or Figure 4c The first functional layer 101 may be directly formed on the substrate 100 or may have an intermediate layer between it and the substrate 100 . There is no limitation to this.
[0072] The first functional layer 101 covers both the emitting device region and the receiving device region, and thus can serve as both a film layer of the emitting device and a film layer of the receiving device.
[0073] In step S30, refer to Figure 2b or Figure 3b or Figure 4c The etch stop layer 200 is specifically an etch stop layer for etching the subsequently formed second functional material layer 1021. The etch stop layer 200 may completely cover the first functional layer 101 or may only cover a portion of the first functional layer 101, and the specific configuration may be based on actual conditions.
[0074] In step S40, refer to Figure 2b or Figure 3c or Figure 4d The second functional material layer 1021 can be made of the same material as the first functional layer 101. Alternatively, the two can be made of different materials that both have piezoelectric properties or conductive properties.
[0075] In step S50, refer to Figure 2c or Figure 3d or Figure 4e Specifically, a patterned mask layer can first be formed on the second functional material layer 1021 through a photolithography process. The patterned mask layer has an opening, which exposes the second functional material layer 1021 located on the receiving device area. Then, the second functional material layer 1021 located on the receiving device area is etched away based on the patterned mask layer. At this time, since the etch stop layer 200 is formed under the second functional material layer 1021, the etching will stop at the etch stop layer 200, and will not cause damage to the first functional layer 101 during the etching process. Therefore, this embodiment can accurately control the thickness of the functional structure layer.
[0076] After removing the second functional material layer 1021 on the receiving device area, the remaining second functional material layer 1021 (ie, the second functional layer 102 ) may be located outside the receiving device area, and may be arranged according to actual conditions.
[0077] As an example, a piezoelectric layer 300 , a bottom electrode layer 400 , or a top electrode layer 500 of a bulk acoustic wave device may include the functional structure layer.
[0078] Parts of the piezoelectric layer 300 , the bottom electrode layer 400 , and the top electrode layer 500 corresponding to the emitting device region are used to form an emitting device, and parts corresponding to the receiving device region are used to form a receiving device.
[0079] In this embodiment, since the second functional material layer 1021 on the receiving device area is removed, the functional structure layer corresponding to the receiving device area lacks the second functional layer 102 relative to the functional structure layer corresponding to the transmitting device area, thereby effectively achieving different thicknesses of the piezoelectric layer 300, or the bottom electrode layer 400 or the top electrode layer 500 in the receiving device area and the transmitting device area.
[0080] At the same time, the provision of the etch-stop layer 200 also prevents the first functional layer 101 from being damaged during the etching process of the second functional material layer 1021, thereby enabling precise control of the thickness of the functional structure layer, and thus the thickness of each film layer of the receiving device and the transmitting device. Therefore, this embodiment can effectively realize the simultaneous formation of the receiving device and the transmitting device on the same substrate.
[0081] In this embodiment, the various membrane layers (piezoelectric layer, bottom electrode layer, top electrode layer) of the transmitting device and the receiving device can be formed using the same process steps, thereby effectively reducing process complexity and effectively reducing process costs.
[0082] In one embodiment, the etch stop layer 200 is a temperature compensation layer, and as an example, the material of the temperature compensation layer is silicon dioxide or fluorine-doped silicon dioxide.
[0083] The temperature compensation layer has a temperature coefficient opposite to that of the piezoelectric layer 300, the bottom electrode layer 400, or the top electrode layer 500. The temperature compensation layer has a negative temperature coefficient, while the piezoelectric layer 300, the bottom electrode layer 400, or the top electrode layer 500 has a positive temperature coefficient. The temperature compensation layer also has a relatively small heat dissipation coefficient, effectively reducing the frequency drift of the device.
[0084] At this time, the etch stop layer 200 not only stops etching, but also effectively shifts the frequency of the device.
[0085] In one embodiment, see Figures 2a to 2f The piezoelectric layer 300 includes a functional structure layer, that is, the functional structure layer is a component of the piezoelectric layer 300 .
[0086] At this time, both the first functional layer 101 and the second functional layer 102 are film layers with piezoelectric properties.
[0087] Furthermore, before step S20, the following steps are also included:
[0088] In step S100 , a patterned bottom electrode layer 400 is formed on the substrate 100 .
[0089] Step S20 includes:
[0090] A first functional layer 101 is formed on the bottom electrode layer 400 and the substrate 100 .
[0091] After step S50, the method further includes:
[0092] In step S300 a , a patterned top electrode layer 500 is formed on the etch stop layer 200 and the second functional layer 102 .
[0093] In step S100, the bottom electrode layer 400 may include an emitting bottom electrode 410 corresponding to the emitting device region and a receiving bottom electrode 420 corresponding to the receiving device region. The emitting bottom electrode 410 and the receiving bottom electrode 420 may be spaced apart.
[0094] In step S20 , as an example, the first functional layer 101 may be directly formed on the substrate 100 and the bottom electrode layer 400 . Of course, an intermediate layer may also be present between the first functional layer 101 and the substrate 100 and the bottom electrode layer 400 .
[0095] Corresponding to step S20, specifically, in step S30, an etch stop layer 200 may be deposited on the first functional layer 10. In step S40, a second functional material layer 1021 may be deposited on the etch stop layer 200. In step S50, after removing the second functional material layer 1021 on the receiving device region, the second functional layer 102 surrounds the receiving device region.
[0096] In step S300a, the top electrode layer 500 may include an emitting top electrode 510 corresponding to the emitting device region and a receiving top electrode 520 corresponding to the receiving device region. The emitting top electrode 510 and the receiving top electrode 520 may be spaced apart.
[0097] In this embodiment, the thickness of the piezoelectric layer 300 of the transmitting device and the receiving device can be effectively different on the same substrate, and the various membrane layers (piezoelectric layer, bottom electrode layer, top electrode layer) of the transmitting device and the receiving device can be formed using the same process steps, thereby effectively reducing the process complexity and effectively reducing the process cost.
[0098] In one embodiment, the bottom electrode layer 400 may further include an interconnecting bottom electrode 430 between the emitting device region and the receiving device region. The interconnecting bottom electrode 430 is spaced apart from the receiving bottom electrode 420 and the emitting bottom electrode 410, thereby being used to interconnect the emitting top electrode 510 and the receiving top electrode 520, so that both can be connected to a common signal terminal.
[0099] In one embodiment, see Figures 3a to 3f , the bottom electrode layer 400 includes a functional structure layer.
[0100] At this time, the first functional layer 101 and the second functional layer 102 are both films with good conductive properties. The first functional layer 101 and the second functional layer 102 corresponding to the emitting device area constitute the emitting bottom electrode 410, and the first functional layer 101 corresponding to the receiving device area constitutes the receiving bottom electrode 420.
[0101] Specifically, as an example, the first functional layer 101 formed in step S20 may be a patterned film layer, and its patterned structure may cover the emitting device region and the receiving device region.
[0102] In step S30 , the etch stop layer 200 can completely cover the first functional layer 101 corresponding to the receiving device area, thereby effectively preventing the first functional layer 101 on the receiving device area from being damaged when the second functional material layer 1021 on the receiving device area is removed.
[0103] At the same time, as an example, the etch stop layer 200 may partially cover the first functional layer 101 corresponding to the emission device region, so that the first functional layer 101 and the second functional layer 102 on the emission device region may contact each other, thereby forming a good electrical connection.
[0104] Furthermore, the first functional layer 101 and the second functional layer 102 on the emission device region may wrap the etch stop layer 200 , thereby improving the electrical connection between the first functional layer 101 and the second functional layer 102 .
[0105] Of course, the etch stop layer 200 may also completely cover the first functional layer 101 corresponding to the emission device region (in this case, the first functional layer 101 and the second functional layer 102 may be electrically connected by subsequently forming a connecting hole), and there is no limitation to this.
[0106] In step S40, a second functional material layer 1021 may be deposited to cover the substrate 100, the etch stop layer 200, and the first functional layer 101. Thereafter, in step S50, the second functional material layer 1021 outside the emission device region is removed.
[0107] In this embodiment, after step S50, the following steps are further included:
[0108] Step S200b, forming a piezoelectric layer 300 on the second functional layer 102, the etch stop layer 200 and the substrate 100;
[0109] Step S300 b , forming a patterned top electrode layer 500 on the piezoelectric layer 300 .
[0110] In step S200 b , the piezoelectric layer 300 may cover the second functional layer 102 , the etch stop layer 200 and the substrate 100 .
[0111] In step S300b, the top electrode layer 500 may include an emitting top electrode 510 corresponding to the emitting device region and a receiving top electrode 520 corresponding to the receiving device region. The emitting top electrode 510 and the receiving top electrode 520 may be spaced apart.
[0112] In this embodiment, the thickness of the bottom electrode layer 400 of the transmitting device and the receiving device can be effectively different on the same substrate, and the various membrane layers (piezoelectric layer, bottom electrode layer, top electrode layer) of the transmitting device and the receiving device can be formed using the same process steps, thereby effectively reducing the process complexity and effectively reducing the process cost.
[0113] In one embodiment, see Figures 4a to 4f The top electrode layer 500 includes functional structural layers. The first functional layer 101 and the second functional layer 102 corresponding to the emitting device region constitute an emitting top electrode 510 , and the first functional layer 101 corresponding to the receiving device region constitutes a receiving top electrode 520 .
[0114] At this time, both the first functional layer 101 and the second functional layer 102 are film layers with good conductive properties.
[0115] Furthermore, before step S50, the method further includes:
[0116] Step S100, forming a patterned bottom electrode layer 400 on the substrate 100;
[0117] In step S200 a , a piezoelectric layer 300 is formed on the bottom electrode layer 400 and the substrate 100 .
[0118] In step S100, the bottom electrode layer 400 may include an emitting bottom electrode 410 corresponding to the emitting device region and a receiving bottom electrode 420 corresponding to the receiving device region. The emitting bottom electrode 410 and the receiving bottom electrode 420 may be spaced apart.
[0119] In step S200 a , the piezoelectric layer 300 may cover the bottom electrode layer 400 and the substrate 100 .
[0120] Meanwhile, in this embodiment, specifically, in step S20 , the first functional layer 101 may be a patterned film layer, and its patterned structure may cover the piezoelectric layer 300 in the emitting device region and the receiving device region.
[0121] In step S30 , the etch stop layer 200 can completely cover the first functional layer 101 corresponding to the receiving device area, thereby effectively preventing the first functional layer 101 on the receiving device area from being damaged when the second functional material layer 1021 corresponding to the receiving device area is removed.
[0122] At the same time, as an example, the etch stop layer 200 may partially cover the first functional layer 101 corresponding to the emission device area, so that the first functional layer 101 and the second functional layer 102 corresponding to the emission device area can contact each other, thereby forming a good electrical connection.
[0123] Furthermore, the first functional layer 101 and the second functional layer 102 on the emission device region may wrap the etch stop layer 200 , thereby improving the electrical connection between the first functional layer 101 and the second functional layer 102 .
[0124] Of course, the etch stop layer 200 may also completely cover the first functional layer 101 corresponding to the emission device region (in this case, the first functional layer 101 and the second functional layer 102 may be electrically connected by subsequently forming a connecting hole), and there is no limitation to this.
[0125] In step S40, a second functional material layer 1021 may be deposited to cover the piezoelectric layer 300, the etch stop layer 200, and the first functional layer 101. Thereafter, in step S50, the second functional material layer 1021 outside the emission device region is removed.
[0126] In one embodiment, after forming the top electrode layer 500, the method further includes:
[0127] Step S400, please refer to Figure 2d , forming a passivation layer 600 on the top electrode layer 500;
[0128] Step S500, please refer to Figure 2e , forming a connecting hole penetrating to the bottom electrode layer 400.
[0129] Step S600, please refer to Figure 2f , forming an interconnection structure 700 covering the inner wall of the communication hole.
[0130] In step S400 , the passivation layer 600 can effectively protect the top electrode layer 500 .
[0131] In step S500, specifically, the bottom electrode layer 400 may include an emitting bottom electrode 410 corresponding to the emitting device region and a receiving bottom electrode 420 corresponding to the receiving device region. Different vias may penetrate the emitting bottom electrode 410 and the receiving bottom electrode 420, respectively, thereby exposing the emitting bottom electrode 410 and the receiving bottom electrode 420.
[0132] When the bottom electrode layer 400 further includes an interconnection bottom electrode 430 , the bottom electrode layer 400 may further include a communication hole penetrating to the interconnection bottom electrode 430 .
[0133] In step S600 , the interconnection structure 700 covers the inner wall of the communication hole, thereby connecting the transmitting bottom electrode 410 and the receiving bottom electrode 420 to the external signal terminal.
[0134] At the same time, when the bottom electrode layer 400 also includes an interconnected bottom electrode 430, the interconnection structure 700 located in the connecting hole that penetrates the interconnected bottom electrode 430 can also simultaneously cover the transmitting top electrode 510 and the receiving top electrode 520, thereby connecting the transmitting top electrode 510 and the receiving top electrode 520 to a common signal terminal.
[0135] Meanwhile, as an example, in step S500 , while forming the communicating hole, a release hole penetrating the sacrificial layer may also be formed, so that the sacrificial layer in the cavity of the substrate 100 can be released through the release hole.
[0136] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 1 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The order of execution of these steps or stages is not necessarily one by one, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.
[0137] In one embodiment, see Figure 2f or Figure 3f or Figure 4f , also provides a bulk acoustic wave device, including: a substrate 100, a first functional layer 101, an etch stop layer 200, and a second functional layer 102.
[0138] The substrate 100 has a transmitting device region and a receiving device region.
[0139] A first functional layer 101 is formed on a substrate 100 and covers at least the emitter and receiver regions. An etch-stop layer 200 is formed on the first functional layer 101. A second functional layer 102 is formed outside the receiver region and on the etch-stop layer 200. Together, the second functional layer 102 and the first functional layer 101 form a functional structure layer.
[0140] In one embodiment, the etch stop layer is a temperature compensation layer.
[0141] In one embodiment, the piezoelectric layer 300 includes a functional structural layer. The BAW device further includes: a patterned bottom electrode layer 400 and a patterned top electrode layer 500 .
[0142] The bottom electrode layer 400 is formed on the substrate 100 , and the first functional layer 101 is formed on the bottom electrode layer 400 and the substrate 100 . The top electrode layer 500 is formed on the etch stop layer 200 and the second functional layer 102 .
[0143] In one embodiment, the bottom electrode layer 400 includes a functional structural layer. The BAW device further includes: a piezoelectric layer 300 and a patterned top electrode layer 500 .
[0144] The piezoelectric layer 300 is formed on the second functional layer 102, the etch stop layer 200, and the substrate 100. The top electrode layer 500 is formed on the piezoelectric layer 300.
[0145] In one embodiment, the top electrode layer 500 includes a functional structure layer 0. The BAW device further includes: a piezoelectric layer 300 and a patterned bottom electrode layer 400.
[0146] The bottom electrode layer 400 is formed on the substrate 100 , the piezoelectric layer 300 is formed on the bottom electrode layer 400 , and the first functional layer 100 is formed on the piezoelectric layer 300 .
[0147] For specific limitations on bulk acoustic wave devices, please refer to the limitations on the manufacturing method of bulk acoustic wave devices above, which will not be repeated here.
[0148] Throughout this specification, reference to "one embodiment" or the like indicates that a particular feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. The schematic descriptions of the above terms throughout this specification do not necessarily refer to the same embodiment or example.
[0149] The various technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features of the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0150] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.
Claims
1. A method for manufacturing a bulk acoustic wave device, characterized in that: include: Providing a substrate, wherein the substrate has a transmitting device area and a receiving device area; forming a first functional layer on the substrate, wherein the first functional layer at least covers the emitting device region and the receiving device region; forming an etch stop layer on the first functional layer; forming a second functional material layer on the etch stop layer; Based on the etch stop layer, removing the second functional material layer on the receiving device area, the remaining second functional material layer constitutes a second functional layer, and the second functional layer and the first functional layer together form a functional structure layer; Wherein, the piezoelectric layer, the bottom electrode layer or the top electrode layer of the bulk acoustic wave device includes the functional structure layer.
2. The method for manufacturing a bulk acoustic wave device according to claim 1, wherein: The etch stop layer is a temperature compensation layer.
3. The method for manufacturing a bulk acoustic wave device according to claim 2, wherein: The material of the temperature compensation layer is silicon dioxide or fluorine-doped silicon dioxide.
4. The method for manufacturing a bulk acoustic wave device according to claim 1, wherein: The piezoelectric layer includes the functional structure layer, Before forming the first functional layer on the substrate, the method further includes: forming a patterned bottom electrode layer on the substrate; The forming of the first functional layer on the substrate comprises: forming a first functional layer on the bottom electrode layer and the substrate; After removing the second functional material layer on the receiving device area based on the etch stop layer, the method further includes: A patterned top electrode layer is formed on the etch stop layer and the second functional layer.
5. The method for manufacturing a bulk acoustic wave device according to claim 1, wherein: The bottom electrode layer includes the functional structure layer, After removing the second functional material layer on the receiving device area based on the etch stop layer, the method further includes: forming a piezoelectric layer on the second functional layer, the etch stop layer, and the substrate; A patterned top electrode layer is formed on the piezoelectric layer.
6. The method for manufacturing a bulk acoustic wave device according to claim 1, wherein: The top electrode layer includes the functional structure layer, Before forming the first functional layer on the substrate, the method further includes: forming a patterned bottom electrode layer on the substrate; forming a piezoelectric layer on the bottom electrode layer and the substrate; The forming of the first functional layer on the substrate comprises: A first functional layer is formed on the piezoelectric layer.
7. The method for manufacturing a bulk acoustic wave device according to claim 5 or 6, characterized in that: The etch stop layer partially covers the first functional layer corresponding to the emission device region, and the first functional layer corresponding to the emission device region is in contact with the second functional layer.
8. A bulk acoustic wave device, characterized in that: include: A substrate having a transmitting device area and a receiving device area; A first functional layer is formed on the substrate and covers at least the emitting device area and the receiving device area; an etch stop layer formed on the first functional layer; A second functional layer is formed outside the receiving device area and is located on the etch stop layer. The second functional layer and the first functional layer together form a functional structure layer, wherein the piezoelectric layer, bottom electrode layer or top electrode layer of the bulk acoustic wave device includes the functional structure layer.
9. The bulk acoustic wave device according to claim 8, wherein The etch stop layer is a temperature compensation layer.
10. The bulk acoustic wave device according to claim 8, wherein The piezoelectric layer includes the functional structure layer, and the bulk acoustic wave device further includes: A patterned bottom electrode layer is formed on the substrate, and the first functional layer is formed on the bottom electrode layer and the substrate; a patterned top electrode layer formed on the etch stop layer and the second functional layer; Alternatively, the bottom electrode layer includes the functional structure layer, and the bulk acoustic wave device further includes: a piezoelectric layer formed on the second functional layer, the etch stop layer and the substrate; a patterned top electrode layer formed on the piezoelectric layer; Alternatively, the top electrode layer includes the functional structure layer, and the bulk acoustic wave device further includes: a patterned bottom electrode layer formed on the substrate; A piezoelectric layer is formed on the bottom electrode layer, and the first functional layer is formed on the piezoelectric layer.
Citation Information
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