Piezoelectric actuator structure, MEMS component, and liquid ejection head

Abstract

The invention provides a piezoelectric actuator structure, an MEMS component and a liquid ejection head, the areas of a vibrating membrane layer, a lower electrode layer, a piezoelectric material layer and an upper electrode layer of the piezoelectric actuator structure are sequentially reduced, and the piezoelectric material layer is made of a single crystal material; a dielectric material layer of the piezoelectric actuator structure partially covers an exposed region of the vibrating membrane, an exposed region of the lower electrode layer, an exposed region of the piezoelectric material layer, and the upper electrode layer. The piezoelectric material layer is made of the single crystal material, and the single crystal material has excellent deformation efficiency and insulativity, so that the performance of the device can be improved, and the material processing difficulty can be reduced. The upper electrode layer and the lower electrode layer are effectively isolated by using the dielectric material layer, so that the safety of the piezoelectric actuator structure is ensured, the interconnection width between the upper electrode layer and the lead is effectively improved, and the production yield of the actuator structure is ensured; meanwhile, by exposing part of the vibrating membrane layer, the vibrating membrane layer has enough deformation performance.

Description

Technical Field

[0001] This disclosure relates to the field of MEMS (Micro Electro Mechanical Systems) technology, and more particularly to a piezoelectric actuator structure, MEMS component, and liquid ejector head. Background Technology

[0002] Piezoelectric inkjet is an inkjet technology widely used in both industrial and home printing markets. Compared to thermal inkjet technology, piezoelectric inkjet technology has advantages such as longer printhead lifespan, a wider range of ink types, and precise droplet size control.

[0003] Piezoelectric liquid ejectors can be manufactured using two technological approaches: precision machining and microelectromechanical systems (MEMS). The MEMS approach, derived from semiconductor processes, offers higher machining precision, resulting in ejectors with typically higher resolution. Furthermore, it combines the high integration and mass production capabilities of semiconductor processes, leading to lower manufacturing costs.

[0004] Traditional piezoelectric liquid ejectors use the sol-gel method to prepare lead zirconate titanate (PZT) thin films. Due to limitations in materials and processes, films prepared using this method are generally difficult to exceed 200 nm in thickness. Therefore, to prepare sufficiently thick PZT films, repeated coating-sintering steps are required. This significantly extends the processing time and thus substantially increases costs.

[0005] Compared to the traditional Sol-gel method, sputtering is more efficient and therefore less expensive for preparing PZT thin films. Furthermore, depending on the technical approach, sputtering can prepare single-crystal PZT thin films, which can achieve self-polarization during fabrication, avoiding the polarization process required after Sol-gel film preparation, further reducing costs. On the other hand, single-crystal PZT thin film materials possess excellent performance parameters and reliability; the piezoelectric devices fabricated from them operate with the same performance as Sol-gel PZT films while requiring significantly less energy.

[0006] However, since sputtering single-crystal PZT requires epitaxial growth to inherit the substrate's crystal orientation, the nozzle's structural design is limited by the process sequence, resulting in relatively low freedom. This makes traditional nozzle designs used in the Sol-gel method unusable when sputtering PZT thin films. Furthermore, sputtered single-crystal PZT exhibits initial self-polarization, leading to a different driving method compared to PZT prepared using the traditional Sol-gel process.

[0007] In particular, in the actuator design of piezoelectric inkjet heads for microelectromechanical systems (MEMS), the piezoelectric material requires an electric field difference between the upper and lower electrodes to deform. To interconnect the upper and lower electrodes with external leads, proper wiring is necessary to prevent short circuits. When fabricating actuators using the Sol-gel method, since the piezoelectric material can be fabricated after the lower electrode is completed, the piezoelectric material is typically used as a dielectric layer to isolate the upper and lower electrodes, thus completely embedding the lower electrode within the piezoelectric material.

[0008] However, the fabrication characteristics of single-crystal materials dictate that they must undergo epitaxial growth. Epitaxial growth cannot achieve the embedding of the piezoelectric material into the lower electrode, and if forced to do so, the crystal orientation of the piezoelectric material will become disordered, affecting both material performance and device reliability.

[0009] On the other hand, the actuator voltage of piezoelectric inkjet heads is relatively high, with peak-to-peak voltages typically reaching tens of volts. This severely tests the voltage withstand characteristics of the insulating material. To achieve safe insulation, sufficient insulation material thickness must be designed, but this can lead to stepped cross-sections during insulation material preparation, which is not conducive to lead material deposition and can cause wire breakage.

[0010] Therefore, for piezoelectric inkjet heads using single-crystal materials, a new structure is needed that can achieve both isolation between the upper and lower electrodes and effectively avoid wire breakage problems caused by the thickness of the insulation layer. Summary of the Invention

[0011] The purpose of this disclosure is to provide a piezoelectric actuator structure, a MEMS component, and a liquid ejector head, among other embodiments.

[0012] The present disclosure provides some embodiments that solve the above-mentioned technical problems through the following technical solutions:

[0013] In a first aspect, a piezoelectric actuator structure is provided, the piezoelectric actuator structure comprising a vibrating diaphragm layer, a lower electrode layer, a piezoelectric material layer and an upper electrode layer stacked sequentially from bottom to top;

[0014] The piezoelectric material layer is made of a single-crystal material;

[0015] The areas of the vibrating diaphragm layer, the lower electrode layer, the piezoelectric material layer, and the upper electrode layer decrease sequentially.

[0016] The piezoelectric actuator structure also includes a dielectric material layer, which partially covers the exposed area of ​​the vibrating diaphragm, the exposed area of ​​the lower electrode layer, and the exposed area of ​​the piezoelectric material layer.

[0017] The dielectric material layer partially covers the upper electrode layer, thus exposing part of the upper electrode layer.

[0018] Optionally, the dielectric material layer covers the end region of the upper electrode layer in the direction of extension;

[0019] The piezoelectric actuator structure also includes metal leads;

[0020] One end of the metal lead partially covers the end region of the upper electrode layer in the direction of extension, so as to form a contact area between the metal lead and the upper electrode layer, and the other end of the metal lead is electrically connected to the inner lead area.

[0021] The metal lead partially covers the dielectric material layer, but the dielectric material layer does not cover the contact area. The metal lead is electrically connected to the external lead through the internal lead area.

[0022] Optionally, the contact area between the metal lead and the upper electrode layer is composed of a semi-circular area and a rectangular area;

[0023] The width of the rectangular region is equal to the diameter of the semicircle of the semicircle region, and the width of the rectangular region is less than the width of the upper electrode layer.

[0024] Optionally, the width of the metal lead covering the dielectric material layer is greater than the width of the contact area.

[0025] Optionally, the dielectric material layer includes at least one of silicon oxide, zirconium oxide, titanium oxide, chromium oxide, and aluminum oxide;

[0026] And / or, the thickness of the dielectric material layer is 200nm-2000nm.

[0027] Optionally, the vibrating diaphragm layer comprises at least one of silicon dioxide, silicon, and zirconium dioxide;

[0028] And / or, the lower electrode layer comprises platinum and strontium ruthenium oxide;

[0029] And / or, the upper electrode layer includes at least one of platinum and strontium ruthenium ruthenium.

[0030] Optionally, the vibrating diaphragm layer comprises, from bottom to top, the silicon dioxide, the silicon, and the zirconium dioxide;

[0031] And / or, the lower electrode layer comprises, from bottom to top, the platinum and the strontium ruthenium oxide;

[0032] And / or, the upper electrode layer comprises, from bottom to top, the strontium ruthenium oxide and the platinum;

[0033] And / or, the piezoelectric material layer includes lead zirconate titanate.

[0034] Optionally, the thickness t1 of the vibrating diaphragm layer satisfies 1µm ≤ t1 ≤ 2µm;

[0035] The thickness t2 of the silicon dioxide satisfies 0 < t2 ≤ 2 μm, the thickness t3 of the silicon satisfies 0.1 ≤ t3 ≤ 2 μm, and the thickness t4 of the zirconium dioxide satisfies 0 < t4 ≤ 1.5 μm.

[0036] And / or, the thickness t5 of the lower electrode layer satisfies 80nm≤t5≤200nm;

[0037] The thickness t6 of the platinum in the lower electrode layer satisfies 50nm≤t6≤150nm, and the thickness t7 of the strontium ruthenium in the lower electrode layer satisfies 5nm≤t7≤100nm.

[0038] And / or, the thickness t8 of the upper electrode layer satisfies 15nm≤t8≤100nm;

[0039] The thickness t9 of the strontium ruthenate in the upper electrode layer satisfies 0 < t9 ≤ 100 nm, and the thickness t10 of the platinum in the upper electrode layer satisfies 0 ≤ t10 ≤ 100 nm.

[0040] And / or, the thickness t11 of the lead zirconate titanate satisfies 0.5um ≤ t11 ≤ 2um.

[0041] In a second aspect, a MEMS component is provided, the MEMS component including the piezoelectric actuator structure described above.

[0042] Thirdly, a liquid ejector head is provided, the liquid ejector head including the MEMS component described above.

[0043] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this disclosure.

[0044] The positive and progressive effects of this disclosure are as follows:

[0045] The piezoelectric actuator structure, MEMS component, and liquid ejector head disclosed herein utilize a single-crystal material for the piezoelectric layer. Single-crystal materials possess excellent electrical and mechanical parameters, offering superior deformation capability and efficiency under equivalent design conditions. They also exhibit excellent voltage withstand and insulation properties, effectively ensuring safe operation of the device under high-voltage conditions. This not only improves device performance but also reduces material processing difficulty. Furthermore, single-crystal materials possess a Curie temperature significantly higher than traditional materials, greatly expanding the range of selectable processing methods. Additionally, by exposing a portion of the vibrating mode layer, the vibrating diaphragm layer acquires sufficient deformation performance, resulting in a wider adjustable droplet size range and faster flight speed during inkjet printing, meeting diverse application requirements. Attached Figure Description

[0046] Figure 1 This is a top view of the piezoelectric actuator structure provided in Embodiment 1 of this disclosure;

[0047] Figure 2 for Figure 1 A magnified view of part B in the image;

[0048] Figure 3 for Figure 2 A cross-sectional schematic diagram of the AA' section. Detailed Implementation

[0049] The present disclosure is further illustrated below by way of embodiments, but the present disclosure is not limited to the scope of the embodiments described herein.

[0050] The prefixes such as "first" and "second" used in this disclosure are merely for distinguishing different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes used to distinguish descriptive objects in this disclosure does not constitute a limitation on the described objects. The description of the described objects is given in the claims or the context of the embodiments, and should not be construed as an unnecessary limitation. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0051] Example 1

[0052] This embodiment provides a piezoelectric actuator structure, such as Figure 1 , Figure 2 and Figure 3 As shown, the piezoelectric actuator structure includes a vibrating diaphragm layer 1, a lower electrode layer 2, a piezoelectric material layer 3, and an upper electrode layer 4 stacked sequentially from bottom to top;

[0053] The piezoelectric material layer is made of a single-crystal material;

[0054] The areas of the vibrating diaphragm layer 1, the lower electrode layer 2, the piezoelectric material layer 3, and the upper electrode layer 4 decrease sequentially.

[0055] The piezoelectric actuator structure also includes a dielectric material layer 5, which partially covers the exposed area of ​​the vibrating diaphragm, the exposed area of ​​the lower electrode layer, and the exposed area of ​​the piezoelectric material layer.

[0056] The dielectric material layer 5 partially covers the upper electrode layer 4, thus exposing part of the upper electrode layer 4.

[0057] like Figure 1 , Figure 2 and Figure 3 As shown, the vibration cavity structure of the actuator includes a vibration cavity (pressure cavity) 6 and a vibration cavity sidewall. The deformation is generated by the inverse piezoelectric effect of the piezoelectric material layer 3, which causes the vibration membrane layer 1 to vibrate, thereby realizing the pressure change in the vibration cavity 6. The ink in the vibration cavity 6 will be ejected through the inkjet nozzle.

[0058] like Figure 3 As shown, the vibrating diaphragm 1 covers the vibrating cavity 6, that is, the lower surface of the vibrating diaphragm 1 is in contact with the top of the vibrating cavity 6 and the side wall of the vibrating cavity, the upper surface of the vibrating diaphragm 1 is in contact with the lower surface of the lower electrode layer 2, the lower surface of the piezoelectric material layer 3 is in contact with the upper surface of the lower electrode layer 2, and the upper surface of the piezoelectric material layer 3 is in contact with the lower surface of the upper electrode layer 4. Because the lower electrode layer 2 covers the vibrating membrane layer 1; the areas of the vibrating membrane layer 1, the lower electrode layer 2, the piezoelectric material layer 3, and the upper electrode layer 4 gradually decrease, forming a stepped shape, so that the vibrating membrane layer 1 has an exposed area relative to the lower electrode layer 2, the piezoelectric material layer 3, and the upper electrode layer 4, the lower electrode layer 2 has an exposed area relative to the piezoelectric material layer 3 and the upper electrode layer 4, and the piezoelectric material layer 3 has an exposed area relative to the upper electrode layer 4; the dielectric material layer 5 partially covers the exposed areas of the vibrating membrane layer 1, the lower electrode layer 2, the piezoelectric material layer 3, and the upper electrode layer 4, thereby ensuring the deformation of the vibrating membrane layer; because the upper electrode layer is partially exposed, it is convenient to realize the electrical connection between the upper electrode layer and the external leads.

[0059] In this embodiment, the piezoelectric actuator structure uses a single-crystal material for the piezoelectric layer. Compared to traditional polycrystalline piezoelectric actuators fabricated using the sol-gel method, single-crystal materials possess superior electrical and mechanical parameters, offering better deformation capability and efficiency under the same design. Single-crystal materials also exhibit excellent voltage withstand and insulation properties, effectively ensuring safe operation of the device under high-voltage conditions. Furthermore, single-crystal materials have a significantly higher Curie temperature than traditional materials, greatly expanding the range of selectable processing methods. The use of a dielectric material layer effectively isolates the upper and lower electrode layers electrically, ensuring the safety of the piezoelectric actuator structure. Simultaneously, by exposing part of the vibrating mode layer, the vibrating diaphragm layer possesses sufficient deformation performance, resulting in a wider adjustable droplet size range and faster flight speed during inkjet printing.

[0060] In an alternative implementation, such as Figure 1 and Figure 3 As shown, the dielectric material layer 5 covers the end region of the upper electrode layer 4 in the extending direction;

[0061] The piezoelectric actuator structure also includes metal leads 7;

[0062] One end of the metal lead 7 covers the end region of the upper electrode layer 4 in the direction of extension to form a contact area between the metal lead 7 and the upper electrode layer 4, and the other end of the metal lead 7 is electrically connected to the inner lead area.

[0063] The metal lead portion is covered by a dielectric material layer, the dielectric material layer 5 does not cover the contact area, and the metal lead 7 is electrically connected to the external lead through the internal lead area.

[0064] The internal lead area provides an electrical connection channel between the metal leads and the external leads. The upper electrode is led out through the metal leads and connected to the external leads. The use of a dielectric material layer effectively isolates the upper electrode layer and the metal leads from the lower electrode layer, ensuring the safety of the piezoelectric actuator structure. Through the structural design of the dielectric material layer, the interconnection width between the metal leads and the upper electrode is significantly extended, the interconnection area is increased and the relative stability of the interconnection area is ensured, effectively reducing the risk of interconnection breakage while ensuring the stability of the contact resistance between the metal leads and the upper electrode.

[0065] In an alternative implementation, such as Figure 1 and Figure 2 As shown, the contact area between the metal lead 7 and the upper electrode layer 4 consists of a semi-circular area and a rectangular area.

[0066] The width of the rectangular region is equal to the diameter of the semicircle of the semicircle region, and the width of the rectangular region is less than the width of the upper electrode layer.

[0067] like Figure 1 and Figure 2 As shown, the contact area (the groove structure formed by a rectangle and a semicircle) is Figure 2 The area outlined by the line shown in the diagram (the length of the two sides of the rectangle plus the entire arc length of the semicircle) has one end of the metal lead covering the end area of ​​the upper electrode layer extending in the direction of the upper electrode layer, forming a contact interconnect between the metal lead and the upper electrode layer. This can effectively increase the length of the sidewalls in the interconnect area, increase the contact area, and thus effectively avoid wire breakage when the metal lead is interconnected with the upper electrode layer, and reduce the resistance increase caused by the lead arrangement.

[0068] The sidewalls of the contact area (i.e., the sidewalls of the dielectric material layer surrounding the contact area) Figure 1 The two sides of the rectangle correspond to the sidewalls of the semicircle along its entire arc length. Figure 3 The slope, i.e., the sidewalls of the contact area, should be sloped to facilitate stable coverage of the metal leads on the upper electrode layer. On one hand, the combination of semi-circular and rectangular structures provides a larger contact area between the metal leads and the upper electrode layer; simultaneously, the length of the metal leads covered on the sidewalls of the dielectric material layer is also greater, reducing the risk of wire breakage due to process variations. On the other hand, this planar design allows for wider metal leads (equal to or even larger than the piezoelectric material layer pattern), ensuring that the contact area does not change with process alignment deviations, thus guaranteeing stable contact resistance. Furthermore, since the dielectric material layer partially covers the lower electrode layer, the widening of the metal leads will not cause short circuits between the metal leads and the lower electrode layer.

[0069] In traditional structures, the interconnect width is relatively small (similar to the width of the rectangle in this disclosure) because the metal leads need to avoid contact with the lower electrode layer. This prevents the interconnect width from being designed to be large, as excessively large metal leads are highly susceptible to short-circuiting with the lower electrode layer, significantly increasing the risk of a short circuit. However, with the piezoelectric actuator structure of this disclosure, the presence of an insulating dielectric layer provides a safe covering space for the metal leads, allowing for a sufficiently large interconnect width without considering short-circuit risks. Therefore, the interconnect width can be maximized to obtain a larger contact area, which offers the advantage of lower contact resistance.

[0070] In an alternative implementation, such as Figure 1 As shown, the width of the metal lead 7 covering the dielectric material layer 5 is greater than the width of the contact area.

[0071] like Figure 2 As shown, the width of the contact area is the same as the width of the rectangular area (i.e., the diameter of the semicircle of the semicircular area). The width of the metal lead covering the dielectric material layer is greater than the width of the contact area, which not only ensures a low and stable contact resistance, but also protects the vibrating cavity of the piezoelectric actuator structure.

[0072] In an alternative embodiment, the dielectric material layer includes at least one of silicon (Si) oxide, zirconium (Zr) oxide, titanium (Ti) oxide, chromium (Cr) oxide, and aluminum (Cr) oxide.

[0073] Specifically, silicon oxides can be silicon dioxide (SiO2), zirconium oxides can be zirconium dioxide (ZrO2), titanium oxides can be titanium dioxide (TiO2), titanium monoxide (TiO), or titanium trioxide (Ti2O3), etc.; chromium oxides can be chromium trioxide (Cr2O3), chromium trioxide (CrO3), or chromium dioxide (CrO2), etc.; aluminum oxides can be aluminum trioxide (Al2O3), etc., and the specific selection is based on actual needs.

[0074] In one alternative embodiment, the thickness of the dielectric material layer is 200nm-2000nm.

[0075] In an optional embodiment, the vibrating diaphragm 1 comprises at least one of silicon dioxide (SiO2), silicon (Si), and zirconium dioxide (ZrO2).

[0076] In an alternative implementation, such as Figure 3 As shown, the vibrating membrane layer 1 consists of silicon dioxide, silicon, and zirconium dioxide from bottom to top.

[0077] In an optional embodiment, the thickness t1 of the vibrating diaphragm layer satisfies 1µm≤t1≤2µm; the thickness t2 of silicon dioxide satisfies 0<t2≤2µm; the thickness t3 of silicon satisfies 0.1≤t3≤2µm; and the thickness t4 of zirconium dioxide satisfies 0<t4≤1.5µm.

[0078] In an alternative embodiment, the thickness t2 of silicon dioxide is greater than the thickness t3 of silicon, and the thickness t2 of silicon dioxide is greater than the thickness t4 of zirconium dioxide.

[0079] Because the diaphragm layer employs a composite thin-film structure, with silicon dioxide comprising a significant portion of the thickness, silicon dioxide provides excellent chemical resistance and insulation, thus improving device reliability. Furthermore, compared to using harder silicon materials, silicon dioxide exhibits better flexibility, allowing for an increase in the thickness of the diaphragm layer while maintaining consistent performance, thereby reducing the difficulty of manufacturing the diaphragm layer.

[0080] In an alternative embodiment, the lower electrode layer comprises platinum (Pt) and strontium ruthenium oxide (SRO).

[0081] In an alternative implementation, such as Figure 3 As shown, the lower electrode layer 2 consists of platinum and strontium ruthenium from bottom to top.

[0082] In an optional embodiment, the thickness t5 of the lower electrode layer satisfies 80nm≤t5≤200nm; the thickness t6 of platinum in the lower electrode layer satisfies 50nm≤t6≤150nm; and the thickness t7 of strontium ruthenium in the lower electrode layer satisfies 5nm≤t7≤100nm.

[0083] In an alternative embodiment, the upper electrode layer comprises at least one of platinum and strontium ruthenium ruthenium.

[0084] In an alternative implementation, such as Figure 3 As shown, the upper electrode layer 4 consists of strontium ruthenate and platinum from bottom to top.

[0085] In an optional embodiment, the thickness t8 of the upper electrode layer satisfies 15nm≤t8≤100nm; the thickness t9 of strontium ruthenate in the upper electrode layer satisfies 0<t9≤100nm; and the thickness t10 of platinum in the upper electrode layer satisfies 0≤t10≤100nm.

[0086] In an alternative embodiment, the piezoelectric material layer comprises lead zirconate titanate (PZT).

[0087] In an alternative embodiment, the thickness t11 of lead zirconate titanate satisfies 0.5 μm ≤ t11 ≤ 2 μm.

[0088] Example 2

[0089] This embodiment provides a MEMS component, which includes the piezoelectric actuator structure in Embodiment 1.

[0090] When the piezoelectric actuator structures are arranged laterally, they can be periodically repeated to form a piezoelectric actuator array, and the arrangement density is not less than 250 actuators / inch. Preferably, the arrangement density is 280 to 320 actuators / inch, forming a high-density piezoelectric actuator array, and the MEMS component includes the aforementioned piezoelectric actuator array.

[0091] MEMS components may also include other structures, such as drive circuitry for driving piezoelectric actuator structures.

[0092] The MEMS component of this embodiment includes the piezoelectric actuator structure from Embodiment 1. The piezoelectric actuator structure comprises, from bottom to top, a vibrating diaphragm layer, a lower electrode layer, a piezoelectric material layer, and an upper electrode layer, stacked sequentially. The areas of the vibrating diaphragm layer, lower electrode layer, piezoelectric material layer, and upper electrode layer decrease sequentially. The piezoelectric actuator structure also includes a dielectric material layer, which partially covers the exposed areas of the vibrating diaphragm, the lower electrode layer, and the piezoelectric material layer. The dielectric material layer partially covers the upper electrode layer, leaving the upper electrode layer partially exposed. Since the piezoelectric material layer is made of single-crystal material, which possesses excellent electrical and mechanical parameters, it can provide better deformation capability and deformation efficiency under the same design. Single-crystal materials also exhibit excellent voltage withstand and insulation properties, effectively meeting the safe use of devices under high-voltage conditions. This not only improves device performance but also reduces the difficulty of material processing. Furthermore, single-crystal materials have a Curie temperature much higher than traditional materials, which greatly expands the range of selectable processing methods for single-crystal materials. The upper and lower electrode layers are effectively isolated by a dielectric material layer, ensuring the safety of the piezoelectric actuator structure. At the same time, by exposing part of the vibration mode layer, the vibration diaphragm layer has sufficient deformation performance, which allows for a wider range of adjustable droplet size and faster flight speed during inkjet printing, meeting different usage requirements and expanding the application scenarios of MEMS components.

[0093] Example 3

[0094] This embodiment provides a liquid ejector head, which includes the MEMS component from Embodiment 1.

[0095] The liquid ejector head is used in conjunction with piezoelectric inkjet printing technology for inkjet printing. The liquid ejector head may also include other components, such as nozzles and flow channels.

[0096] The liquid ejector head of this embodiment includes the MEMS component from Embodiment 2. The MEMS component includes the piezoelectric actuator structure from Embodiment 1. The piezoelectric actuator structure includes a vibrating diaphragm layer, a lower electrode layer, a piezoelectric material layer, and an upper electrode layer stacked sequentially from bottom to top; the areas of the vibrating diaphragm layer, lower electrode layer, piezoelectric material layer, and upper electrode layer decrease sequentially. The piezoelectric actuator structure also includes a dielectric material layer, which partially covers the exposed areas of the vibrating diaphragm, the lower electrode layer, and the piezoelectric material layer; the dielectric material layer partially covers the upper electrode layer, leaving the upper electrode layer partially exposed. Since the piezoelectric material layer is made of single-crystal material, which possesses excellent electrical and mechanical parameters, it can provide better deformation capability and deformation efficiency under the same design. Single-crystal material also has excellent voltage withstand capability and insulation, effectively meeting the safe use of devices under high-voltage conditions, not only improving device performance but also reducing the difficulty of material processing. Simultaneously, single-crystal material has a Curie temperature much higher than traditional materials, which can greatly expand the range of selectable processes for single-crystal material. The upper and lower electrode layers are effectively isolated by a dielectric material layer, ensuring the safety of the piezoelectric actuator structure. At the same time, by exposing part of the vibration mode layer, the vibration diaphragm layer has sufficient deformation performance, which allows for a wider range of adjustable droplet size and faster flight speed during inkjet printing, meeting different application requirements, expanding the application scenarios of MEMS components, and improving the performance of the liquid ejector head.

[0097] While specific embodiments of this disclosure have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this disclosure is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this disclosure, but all such changes and modifications fall within the scope of protection of this disclosure.

Claims

1. A piezoelectric actuator structure, characterized in that, The piezoelectric actuator structure includes a vibrating diaphragm layer, a lower electrode layer, a piezoelectric material layer and an upper electrode layer stacked sequentially from bottom to top; The piezoelectric material layer is made of a single-crystal material; The areas of the vibrating diaphragm layer, the lower electrode layer, the piezoelectric material layer, and the upper electrode layer decrease sequentially. The piezoelectric actuator structure also includes a dielectric material layer, which partially covers the exposed area of ​​the vibrating diaphragm, the exposed area of ​​the lower electrode layer, and the exposed area of ​​the piezoelectric material layer. The dielectric material layer partially covers the upper electrode layer, thus exposing part of the upper electrode layer.

2. The piezoelectric actuator structure according to claim 1, characterized in that, The dielectric material layer covers the end region of the upper electrode layer in the direction of extension; The piezoelectric actuator structure also includes metal leads; One end of the metal lead partially covers the end region of the upper electrode layer in the direction of extension, so as to form a contact area between the metal lead and the upper electrode layer, and the other end of the metal lead is electrically connected to the inner lead area. The metal lead partially covers the dielectric material layer, but the dielectric material layer does not cover the contact area. The metal lead is electrically connected to the external lead through the internal lead area.

3. The piezoelectric actuator structure according to claim 2, characterized in that, The contact area between the metal lead and the upper electrode layer consists of a semi-circular area and a rectangular area; The width of the rectangular region is equal to the diameter of the semicircle of the semicircle region, and the width of the rectangular region is less than the width of the upper electrode layer.

4. The piezoelectric actuator structure according to claim 3, characterized in that, The width of the metal lead covering the dielectric material layer is greater than the width of the contact area.

5. The piezoelectric actuator structure according to claim 1, characterized in that, The dielectric material layer includes at least one of silicon oxide, zirconium oxide, titanium oxide, chromium oxide, and aluminum oxide; And / or, the thickness of the dielectric material layer is 200nm-2000nm.

6. The piezoelectric actuator structure according to claim 1, characterized in that, The vibrating diaphragm layer includes at least one of silicon dioxide, silicon, and zirconium dioxide; And / or, the lower electrode layer comprises platinum and strontium ruthenium oxide; And / or, the upper electrode layer includes at least one of platinum and strontium ruthenium ruthenium.

7. The piezoelectric actuator structure according to claim 6, characterized in that, The vibrating diaphragm layer comprises, from bottom to top, the silicon dioxide, the silicon, and the zirconium dioxide; And / or, the lower electrode layer comprises, from bottom to top, the platinum and the strontium ruthenium oxide; And / or, the upper electrode layer comprises, from bottom to top, the strontium ruthenium oxide and the platinum; And / or, the piezoelectric material layer includes lead zirconate titanate.

8. The piezoelectric actuator structure according to claim 7, characterized in that, The thickness t1 of the vibrating diaphragm layer satisfies 1um≤t1≤2um; The thickness t2 of the silicon dioxide satisfies 0 < t2 ≤ 2 μm, the thickness t3 of the silicon satisfies 0.1 ≤ t3 ≤ 2 μm, and the thickness t4 of the zirconium dioxide satisfies 0 < t4 ≤ 1.5 μm. And / or, the thickness t5 of the lower electrode layer satisfies 80nm≤t5≤200nm; The thickness t6 of the platinum in the lower electrode layer satisfies 50nm≤t6≤150nm, and the thickness t7 of the strontium ruthenium in the lower electrode layer satisfies 5nm≤t7≤100nm. And / or, the thickness t8 of the upper electrode layer satisfies 15nm≤t8≤100nm; The thickness t9 of the strontium ruthenate in the upper electrode layer satisfies 0 < t9 ≤ 100 nm, and the thickness t10 of the platinum in the upper electrode layer satisfies 0 ≤ t10 ≤ 100 nm. And / or, the thickness t11 of the lead zirconate titanate satisfies 0.5um ≤ t11 ≤ 2um.

9. A MEMS component, characterized in that, The MEMS component includes a piezoelectric actuator structure as described in any one of claims 1-8.

10. A liquid ejector head, characterized in that, The liquid ejector head includes the MEMS component as described in claim 9.

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