PZT target material and preparation process thereof
By independently setting the annealing and sputtering temperatures, and combining them with specific etching solutions and etching processes, the problem of PZT film composition deviating from stoichiometry was solved, improving the piezoelectric properties and preparation quality of PZT targets, while simplifying the operation of reactive ion etching equipment.
Patent Information
- Application Number
- CN202511409644.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2026-01-30
AI Technical Summary
In the prior art, the annealing temperature of PZT thin films is the same as the sputtering temperature, which causes the film composition to easily deviate from the stoichiometry, affecting the piezoelectric properties.
By independently setting the annealing temperature and sputtering temperature, maintaining the annealing temperature at 465℃ for 5 minutes, and combining this with a specific etching solution and etching process, the stability of the film composition is ensured.
This improved the piezoelectric properties of PZT targets, ensured the quality of PZT target preparation, and simplified the operation process of the reactive ion etching device.
Smart Images
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Abstract
Description
Technical Field
[0001] This application relates to the field of PZT target technology, and in particular to a PZT target and its preparation process. Background Technology
[0002] PZT-MEMS (lead zirconate titanate thin film piezoelectric microelectromechanical systems) is a high-end sensor and actuator technology that combines piezoelectric materials with micro-nano fabrication techniques. Its core lies in utilizing the excellent piezoelectric properties of PZT thin films to achieve the interconversion of mechanical energy and electrical energy. In existing technologies, PZT thin films are commonly prepared using methods such as sol-gel deposition, pulsed laser deposition (PLD), chemical vapor deposition (CVD), and radio frequency magnetron sputtering. The sol-gel method involves spin-coating a precursor solution into a film, followed by low-temperature annealing to form PZT; pulsed laser deposition allows for precise control of composition; chemical vapor deposition offers a relatively fast deposition rate; and radio frequency magnetron sputtering can deposit thin films and control crystallinity by bombarding the target with high-energy particles. However, these traditional processes all have certain limitations in practical applications.
[0003] Regarding the aforementioned technologies, since the sputtering step in the traditional process generally makes the film annealing temperature the same as the sputtering temperature, keeping the film annealing temperature within the range of the sputtering temperature (generally 500-600℃), it is difficult to stabilize the film annealing temperature. As a result, after annealing, the film composition is prone to deviate from the stoichiometry, leading to a decrease in the piezoelectric properties of the PZT target material, which needs to be improved. Summary of the Invention
[0004] To ensure the piezoelectric properties of the prepared PZT target, this application provides a PZT target and its preparation process.
[0005] Firstly, this application provides a PZT target preparation process, which adopts the following technical solution: A PZT target preparation process, characterized by comprising the following steps: 1. A PZT target preparation process, characterized by comprising the following steps: Preparing SOI silicon wafers: Select a silicon wafer or silicon-on-insulator wafer as the substrate; Silicon doping: Doping silicon onto the surface of a silicon wafer; Deposited insulating layer: On the silicon-doped surface of a silicon wafer, a thermally oxidized layer or a SiN layer deposited by chemical vapor deposition is grown. x The layer serves as an insulating layer; Deposition of the lower electrode layer: Titanium is sputtered onto the insulating layer as an adhesion layer, and during the sputtering of titanium, rapid thermal annealing (RIA) is used to form TiO2 on the surface of the titanium. x A layer is formed by sputtering platinum onto the adhesion layer as a conductive electrode to form the lower electrode layer. Depositing PZT piezoelectric layer: at sputtering temperature (500-600℃), radio frequency magnetron sputtering is performed on the lower electrode layer, and the deposition rate is 35-48 nm / min, so as to form a PZT piezoelectric layer; after sputtering, an annealing temperature of 465℃ is maintained in the chamber and annealing is performed for 5 minutes; Etching PZT piezoelectric layer: after 3μm photoresist is spin-coated on the PZT piezoelectric layer, soft baking at 110℃, exposure and development, and hard baking at 120℃, the bottom of the photoresist is etched; then 15 seconds of etching is performed on the PZT piezoelectric layer using an etching solution, followed by 5 seconds of etching using 30% HCI aqueous solution; Etching lower electrode layer: using Cl2 / HF mixed gas, the lower electrode layer and the insulating layer are subjected to reactive ion etching (RIE) through a reaction ion etching device; Depositing top layer: platinum (Pt) or iridium (Ir) is deposited by sputtering or evaporation to fill the part of the vacancy after etching on the lower electrode layer and the insulating layer; Etching insulating layer: dry etching is performed first, then positive photoresist is spin-coated on the photoresist pattern, so that a pattern is formed after exposure and development; then the insulating layer is dry etched; Depositing top electrode: platinum (Pt) or iridium (Ir) is deposited by sputtering or evaporation at the etched part to form an upper and lower electrode structure; Etching top silicon: the top electrode is subjected to reactive ion etching (RIE) through a reaction ion etching device, so as to define the pattern by photolithography; Etching bottom silicon and silicon dioxide: the silicon substrate is etched by deep reactive ion etching (DRIE), and the buried oxygen layer is used as the etching stop layer, and then the silicon dioxide layer is removed.
[0006] Compared with the sputtering step in the traditional process in the prior art, the thin film annealing temperature is the same as the sputtering temperature, which is maintained within the range of the sputtering temperature (generally at 500-600℃), so that the thin film annealing temperature is difficult to stabilize, and then the composition of the thin film after annealing is easy to deviate from the stoichiometric ratio; by independently setting the annealing temperature and the sputtering temperature, the annealing temperature in the chamber is maintained at 465℃ during annealing, and annealing is maintained for 5 minutes, which effectively stabilizes the annealing temperature, thereby reducing the probability of the composition of the thin film after annealing deviating from the stoichiometric ratio, and further improving the piezoelectric performance of the PZT target material and ensuring the preparation quality of the PZT target material.
[0007] Preferably, the etching solution is composed of BHF (5.8%), HNO3 (3.8%) and DI water (90.4%).
[0008] As a preferred, the total etching rate is 60 nm / s, the side wall inclination angle is 30°, and the undercut amount is controlled in 0-0.62 μm when etching for 5 seconds by using 30% HCl aqueous solution.
[0009] As a preferred, the etching pressure is 10-200 mTorr, the radio frequency power is 100-300 W, and the bias voltage is -50 to -200 V when dry etching the insulating layer.
[0010] As a preferred, the reaction ion etching device comprises a device body, an opening is formed in the top of the device body, a switch door and a switch mechanism are further arranged on the device body, the switch door is used for closing the opening in the top of the device body, the switch mechanism comprises a switch frame and a switch assembly, the bottom of the switch frame is rotationally connected with the device body, the switch door is arranged on the switch frame, and the switch assembly is used for driving the switch frame to rotate.
[0011] By adopting the above technical scheme, when it is necessary to replace or clean the device in the reaction ion etching device, the relevant personnel can drive the switch frame to rotate through the switch mechanism, so that the switch frame drives the switch door to rotate together, the switch door is gradually opened, the closure of the top of the device body is removed, compared with the mode that the device body is fixedly connected with the external shell through bolts in the prior art, the bolts on the external shell do not need to be removed, and the operation of the relevant personnel is effectively facilitated.
[0012] As a preferred, an opening is further formed in the side wall of the device body, a maintenance door is further arranged on the device body, the maintenance door is used for closing the opening in the side wall of the device body, and a driving mechanism is further arranged on the device body, the driving mechanism is used for driving the maintenance door to displace, so as to cancel the closure of the opening in the side wall of the device body.
[0013] By adopting the above technical scheme, when it is necessary to replace or clean the device in the reaction ion etching device, the relevant personnel can drive the switch frame to rotate through the switch mechanism, so that the switch frame drives the switch door to rotate together, the switch door is gradually opened, the closure of the top of the device body is removed, compared with the mode that the device body is fixedly connected with the external shell through bolts in the prior art, the bolts on the external shell do not need to be removed, and the operation of the relevant personnel is effectively facilitated.
[0014] As a preferred, the driving mechanism comprises a driving frame, a rotating frame and a linkage assembly, the driving frame is slidingly connected with the device body and rotationally connected with the end of the maintenance door, the rotating frame is slidingly connected with the maintenance door and rotationally connected with the device body, and the linkage assembly is used for driving the driving frame to slide.
[0015] By adopting the technical scheme, when the maintenance door needs to be opened, the linkage assembly can drive the main frame to slide, so that the main frame drives the end of the maintenance door to displace, and the maintenance door rotates relative to the main frame, in the process, the rotating frame slides relative to the maintenance door and rotates relative to the device body, so as to adapt to the displacement of the maintenance door, so as to drive the displacement of the maintenance door, and the maintenance door can be retracted into the device body, effectively reducing the space occupied by the device body after the maintenance door is opened, and facilitating the operation of the relevant personnel.
[0016] Preferably, the linkage assembly comprises a linkage frame, an adaptive frame and a pushing frame, one end of the linkage frame is in sliding connection with the switch door, the other end is in rotary connection with the adaptive frame, the adaptive frame is sleeved on the pushing frame and is in rotary connection with the pushing frame, the pushing frame is in sliding connection with the device body, and the sliding direction of the pushing frame is the same as that of the main frame, and the main frame is located on the sliding path of the pushing frame.
[0017] By adopting the technical scheme, in the process that the switch door slides relative to the switch frame, the switch door can drive the linkage frame to displace, so that the end of the linkage frame away from the switch door drives the pushing frame to slide through the adaptive frame, so that the pushing frame drives the main frame to slide after abutting against the main frame, thereby driving the sliding of the main frame, effectively realizing the linkage between the switch door and the maintenance door, and facilitating the operation of the relevant personnel.
[0018] Preferably, the switch door is in sliding connection with the switch frame, and the sliding direction of the switch door is the length direction of the switch frame, the switch assembly comprises a driving frame and a driving piece, one end of the driving frame is in rotary connection with the switch door, the other end is in rotary connection with the device body, and the driving piece is used to drive the switch frame to rotate.
[0019] By adopting the technical scheme, when the driving piece drives the switch frame to rotate, the switch frame can drive the switch door to rotate, and in the process that the switch door rotates, the driving frame can slide relative to the device body, so that the driving frame drives the switch door to slide relative to the switch frame, so that the switch door gradually approaches the side wall of the device body in the process of rotating, thereby effectively reducing the size of the space occupied by the switch door after rotating.
[0020] On the other hand, the application also provides a PZT target material prepared by the above PZT target material preparation process.
[0021] In summary, the application has at least one of the following beneficial technical effects: 1. The annealing temperature and sputtering temperature are set independently, so that the annealing temperature in the chamber is maintained at 465℃ and annealed for 5 minutes. This effectively stabilizes the annealing temperature, thereby reducing the probability of the film composition deviating from the stoichiometry after annealing, thus improving the piezoelectric properties of the PZT target and ensuring the preparation quality of the PZT target. 2. The design of the switch door and switch mechanism allows personnel to rotate the switch frame via the switch mechanism when the equipment inside the reactive ion etching device needs to be replaced or cleaned. This causes the switch frame to rotate the switch door, gradually opening the door and releasing the seal on the top of the device body. Compared to the existing technology that uses bolts to fix the outer shell of the device body, this application eliminates the need to remove the bolts on the outer shell, effectively facilitating the operation of relevant personnel. 3. The design of the maintenance door and drive mechanism allows personnel to move the maintenance door via the drive mechanism when it is necessary to replace or clean the devices inside the reactive ion etching apparatus. This allows the maintenance door to open the side wall opening of the apparatus body, thus removing the closure of the side wall opening. Compared to the existing technology that uses bolts to fix the outer shell of the apparatus body, this application eliminates the need to remove the bolts on the outer shell, effectively facilitating the operation of relevant personnel. Attached Figure Description
[0022] Figure 1 This is a schematic diagram illustrating the overall reactive ion etching apparatus in Embodiment 2 of this application.
[0023] Figure 2 This is a schematic diagram illustrating the switching mechanism in Embodiment 2 of this application.
[0024] Figure 3 This is a structural schematic diagram of the linkage component used in Embodiment 2 of this application.
[0025] Explanation of reference numerals in the attached drawings: 1. Device body; 2. Switch door; 3. Switch mechanism; 31. Switch frame; 32. Switch assembly; 321. Drive frame; 322. Drive component; 4. Maintenance door; 5. Drive mechanism; 51. Active frame; 52. Rotating frame; 53. Linkage assembly; 531. Linkage frame; 532. Adaptive frame; 533. Push frame; 6. Return spring. Detailed Implementation
[0026] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.
[0027] Example 1: Example 1 of this application discloses a PZT target preparation process, which includes the following steps: S1. Prepare SOI silicon wafer: Select a silicon wafer or silicon-on-insulator (SOI) wafer as the substrate, preferably a SOI wafer, so that the buried insulating layer (BOX) in the SOI wafer can serve as an etching stop layer, which facilitates the release of the subsequent structure. The SiO2 thickness in the silicon wafer is 1μm. S2, Silicon doping: Doping silicon onto the surface of a silicon wafer; S3. Depositing an insulating layer: On the silicon-doped surface of the silicon wafer, a thermal oxide layer (preferably SiO2 with a thickness of approximately 100 nm) or SiN by chemical vapor deposition (CVD) is grown. x The layer serves as an insulating layer, thereby acting as a diffusion barrier between the bottom electrode and the silicon substrate to prevent metal atom diffusion from causing device failure. S4. Deposition of the lower electrode layer: Titanium is sputtered onto the insulating layer as an adhesion layer, with a thickness of 20 nm. During titanium sputtering, rapid thermal annealing (RIA) is used to form TiO2 on the surface of the titanium. x A layer is formed to enhance adhesion to platinum; then platinum is sputtered onto the adhesion layer as a conductive electrode to form a lower electrode layer with a thickness of 100 nm. S5. Deposition of PZT piezoelectric layer: At the sputtering temperature (500-600℃), the lower electrode layer is sputtered by radio frequency magnetron sputtering at a deposition rate of 35-48 nm / min to form a PZT piezoelectric layer; after sputtering, the annealing temperature is maintained at 465℃ in the chamber and annealed for 5 minutes to avoid phase transformation (such as the formation of unintended perovskite phase) and to improve the ferroelectricity of the film; S6. Etching the PZT piezoelectric layer: Spin-coat a 3μm photoresist onto the PZT piezoelectric layer. After soft baking at 110℃, exposure and development, and hard baking at 120℃, etch the bottom of the photoresist (e.g., with O2 plasma) to ensure the etched area is completely open. Then, use an etching solution (composed of BHF (5.8%), HNO3 (3.8%), and DI water (90.4%)) to etch the PZT piezoelectric layer for 15 seconds to selectively remove the PZT piezoelectric layer and expose part of the bottom electrode. Dissolve the PbCIF residue with NHO3. Next, etch with a 30% HCl aqueous solution for 5 seconds to completely expose the bottom electrode, achieving a total etching rate of 60nm / s, a sidewall tilt angle of 30°, and a bottom cut depth controlled between 0-0.62μm. S7. Etching the lower electrode layer: Using a reactive ion etching device, a Cl2 / HF mixed gas is used to perform reactive ion etching (RIE) on the lower electrode layer and the insulating layer below the lower electrode layer to ensure that the thickness of the insulating layer is the same in subsequent etching. S8. Deposit top layer: Using reactive ion etching (RIE) or wet etching, platinum (Pt) or iridium (Ir) is deposited by sputtering or evaporation to deposit the etched lower electrode layer and insulating layer, thereby filling the etched voids. S9. Etching the insulating layer: First, dry etching (RIE / DRIE) is performed. Then, positive photoresist is spin-coated onto the photoresist pattern (the photoresist pattern is designed according to the motor layout and covers the insulating areas to be retained, exposing the windows to be etched), so that micron-level patterns are formed after exposure and development. Then, the insulating layer is dry-etched. During the dry etching of the insulating layer, the etching pressure is 10-200 mTorr, the RF power is 100-300 W, and the bias voltage is -50 to -200 V to ensure etching rate and selectivity. S10. Deposit top electrode: Sputter or evaporate platinum (Pt) or iridium (Ir) to deposit at the etched area to form the top and bottom electrode structures; S11. Etch top silicon: Perform reactive ion etching (RIE) on the top electrode using a reactive ion etching device to define the pattern through photolithography. S12, Etching the underlying silicon and silicon dioxide: The silicon substrate is etched by deep reactive ion etching (DRIE), and the buried insulating layer (BOX) is used as an etch stop layer to prevent over-etching; then the SiO2 layer in the silicon wafer is removed by XeF2 or HF vapor.
[0028] Embodiment 1 of this application also provides a PZT target material, which is prepared by the above-described PZT target material preparation process.
[0029] Example 2: Embodiment 2 of this application discloses a reactive ion etching apparatus, which is the same reactive ion etching apparatus as in Embodiment 1. (Refer to...) Figure 1 and Figure 2 The reactive ion etching apparatus includes an apparatus body 1, with an opening at the top. The apparatus body 1 also includes a switch door 2 and a switch mechanism 3. The switch door 2 is used to close the opening at the top of the apparatus body 1. The switch mechanism 3 includes a switch frame 31 and switch components 32. In this embodiment, two switch components 32 are provided, with each component positioned on one side of the switch door 2 along its width.
[0030] Reference Figure 1 and Figure 2Each switch assembly 32 includes a drive frame 321 and a drive member 322. In this embodiment, the drive member 322 is an electric telescopic rod. The bottom of the electric telescopic rod is rotatably connected to the inner bottom wall of the device body 1 via a support and a pin. The piston rod is inclined upward and rotatably connected to the top of the switch frame 31 via a pin. The bottom of the switch frame 31 is rotatably connected to the device body 1 via bolts, and the top of the switch frame 31 extends vertically upward.
[0031] Reference Figure 1 and Figure 2 One end of each drive frame 321 is rotatably connected to the device body 1 via a pin, the bottom of each drive frame 321 is rotatably connected to the device body 1 via a pin, and the top of each drive frame 321 is inclined and rotatably connected to the lower side of the switch door 2 via a pin. The switch door 2 is fitted onto the top of the switch frame 31 and is slidably connected to the switch frame 31, with the sliding direction being the length direction of the switch frame 31.
[0032] Reference Figure 1 and Figure 2 In this embodiment of the application, the top of the side wall of the device body 1 near the switch frame 31 is also provided with an opening to allow for the displacement of the switch door 2. Correspondingly, the switch door 2 is also provided with a part that blocks the opening so that when the switch door 2 is in the closed state, the opening is blocked and closed.
[0033] Reference Figure 1 and Figure 2 Initially, the switch frame 31 is closed, sealing the opening on the top of the device body 1. When the drive unit 322 rotates the switch frame 31, the switch frame 31 rotates the switch door 2 together, causing the switch door 2 to gradually open. During this process, one end of the drive frame 321 rotates relative to the device body 1, causing the other end of the drive frame 321 to pull the switch door 2 to slide relative to the switch frame 31, making the switch door 2 gradually closer to the device body 1, thereby reducing the space occupied by the switch door 2 and the device body 1.
[0034] Reference Figure 1 , Figure 2 and Figure 3 An opening is provided on one side wall of the device body 1 along its width direction. A maintenance door 4 and a drive mechanism 5 are also provided on the device body 1. The maintenance door 4 is used to close the opening on the side wall of the device body 1. The drive mechanism 5 includes an active frame 51, a rotating frame 52, and a linkage assembly 53. The active frame 51 is located inside the device body 1 at one end near the switch frame 31.
[0035] Reference Figure 1 , Figure 2 and Figure 3The active frame 51 is slidably connected to the bottom of the device body 1 via a slide rail, and the sliding direction is the width direction of the device body 1. The active frame 51 is rotatably connected to the end of the maintenance door 4 via a pin. A return spring 6 is also provided on the side of the active frame 51 away from the maintenance door 4. The return spring 6 is fixedly sleeved on the device body 1, with one end abutting against the side wall of the active frame 51 and the other end abutting against the inner wall of the device body 1, so as to reset the active frame 51 by its own elastic force.
[0036] Reference Figure 1 , Figure 2 and Figure 3 The rotating frame 52 is slidably connected to the side of the maintenance door 4 facing the interior of the device body 1 via a slide rail, and the sliding direction is the length direction of the maintenance door 4. The bottom of the rotating frame 52 is rotatably connected to the device body 1 via a pin. In this embodiment, a locking device is also provided inside the device body 1, which is used to lock the active frame 51 when the maintenance door 4 is closed.
[0037] Reference Figure 3 In this embodiment, the locking device is configured as a combination of an electric telescopic rod and a locking rod, so that the electric telescopic rod can drive the locking rod to slide in a direction perpendicular to the sliding direction of the active frame 51, thereby inserting it into the active frame 51 and locking the active frame 51.
[0038] Reference Figure 2 and Figure 3 The linkage component 53 includes a linkage frame 531, an adapting frame 532, and a pushing frame 533. In this embodiment, two linkage frames 531 are provided, located on opposite sides of the adapting frame 532. One end of each linkage frame 531 is rotatably connected to the opening / closing door 2 via a pin, and the other end is inclined downwards and rotatably connected to the adapting frame 532 via a pin. The adapting frame 532 is sleeved on the pushing frame 533 and rotatably connected to the pushing frame 533 via a bearing.
[0039] Reference Figure 1 , Figure 2 and Figure 3 The push frame 533 is located on the side of the active frame 51 near the maintenance door 4, and is slidably connected to the device body 1 via a slide rail. The sliding direction is the same as the sliding direction of the active frame 51, and the active frame 51 is located on the sliding path of the push frame 533.
[0040] Reference Figure 1 , Figure 2 and Figure 3Initially, both the switch door 2 and the maintenance door 4 are closed. At this time, the active frame 51 and the push frame 533 are located at the end of their sliding path closest to the maintenance door 4, and the sliding frame is not in contact with the active frame 51. When the drive unit 322 drives the switch frame 31 to rotate, causing the switch door 2 to slide relative to the switch frame 31, the switch frame 31 drives the linkage frame 531 to shift, which in turn causes the linkage frame 531 to drive the push frame 533 to slide away from the maintenance door 4 through the adaptation frame 532.
[0041] Reference Figure 1 , Figure 2 and Figure 3 During this process, the adapting frame 532 rotates relative to the pushing frame 533, thereby adapting to the rotation of the opening and closing door 2. When the pushing frame 533 abuts against the active frame 51, thereby pushing the active frame 51 to slide, the active frame 51 slides away from the maintenance door 4, thereby causing the end of the maintenance door 4 to displace. During this process, the rotating frame 52 rotates relative to the device body 1 and slides relative to the maintenance door 4, thereby causing the maintenance door 4 to displace and retract into the device body 1.
[0042] The implementation principle of the reactive ion etching apparatus in Embodiment 2 of this application is as follows: When the driving component 322 drives the switch frame 31 to rotate, the switch frame 31 drives the switch door 2 to rotate together, thereby gradually opening the switch door 2. During this process, one end of the driving frame 321 rotates relative to the device body 1, thereby causing the other end of the driving frame 321 to pull the switch door 2 to slide relative to the switch frame 31, so that the switch door 2 gradually moves closer to the device body 1, thereby reducing the space occupied by the switch door 2 and the device body 1.
[0043] During this process, the switch frame 31 causes the linkage frame 531 to shift, which in turn causes the linkage frame 531 to slide away from the maintenance door 4 via the adapting frame 532. At this time, the adapting frame 532 rotates relative to the pushing frame 533, thereby adapting to the rotation of the switch door 2. When the pushing frame 533 abuts against the active frame 51, thereby pushing the active frame 51 to slide, the active frame 51 slides away from the maintenance door 4, thereby causing the end of the maintenance door 4 to shift. During this process, the rotating frame 52 rotates relative to the device body 1 and slides relative to the maintenance door 4, thereby causing the maintenance door 4 to shift and retract into the device body 1.
[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A process for the preparation of PZT target material, characterized by: The method comprises the following steps: Preparation of SOI silicon wafer: selecting a silicon wafer or a silicon-on-insulator wafer as a substrate; Silicon wafer doping: doping silicon on the surface of the silicon wafer; Deposited insulating layer: On the silicon-doped surface of a silicon wafer, a thermally oxidized layer or a SiN layer deposited by chemical vapor deposition is grown. x The layer serves as an insulating layer; Depositing a lower electrode layer: sputtering titanium as an adhesion layer on the insulating layer, and while sputtering the titanium, forming a TiO x layer on the surface of the titanium by rapid thermal annealing (RTA), and then sputtering platinum as a conductive electrode on the adhesion layer to form a lower electrode layer; Deposition of PZT piezoelectric layer: radio frequency magnetron sputtering is performed on the lower electrode layer at a sputtering temperature (500-600℃) to form a PZT piezoelectric layer at a deposition rate of 35-48 nm / min; after sputtering, an annealing temperature of 465℃ is maintained in the chamber for 5 minutes; Etching of PZT piezoelectric layer: 3μm photoresist is spin-coated on the PZT piezoelectric layer, and after soft baking at 110℃, exposure and development, and hard baking at 120℃, the bottom of the photoresist is etched; then, 15 seconds of etching is performed on the PZT piezoelectric layer using an etching solution, followed by 5 seconds of etching using a 30% HCI aqueous solution; Etching of lower electrode layer: a Cl2 / HF mixed gas is used to perform reactive ion etching (RIE) on the lower electrode layer and the insulating layer by a reaction ion etching device; Deposition of top layer: platinum (Pt) or iridium (Ir) is deposited by sputtering or evaporation to fill the part of the lower electrode layer and the insulating layer after etching; Etching of insulating layer: dry etching is first performed, and then positive photoresist is spin-coated on the photoresist pattern to form a pattern after exposure and development; Then, dry etching of the insulating layer is performed; Deposition of top electrode: platinum (Pt) or iridium (Ir) is deposited by sputtering or evaporation at the etched part to form a top and bottom electrode structure; Etching of top silicon layer: reactive ion etching (RIE) is performed on the top electrode by a reaction ion etching device to define the pattern by photolithography; Etching of bottom silicon and silicon dioxide: the silicon substrate is etched by deep reactive ion etching (DRIE), and the buried oxygen layer is used as an etching stop layer, and then the silicon dioxide layer is removed.
2. The process for preparing a PZT target according to claim 1, characterized in that: The etching solution is composed of BHF (5.8%), HNO3 (3.8%), and DI water (90.4%).
3. The process for preparing PZT target material according to claim 1, characterized in that: When etching for 5 seconds using a 30% HCI aqueous solution, the total etching rate is 60 nm / s, the side wall inclination angle is 30°, and the undercut amount is controlled within 0-0.62μm.
4. The PZT target preparation process according to claim 1, wherein: When dry etching the insulating layer, the etching pressure is 10-200 mTorr, the radio frequency power is 100-300 W, and the bias voltage is -50 to -200 V.
5. The process for preparing PZT target material according to claim 1, wherein: The reaction ion etching device comprises a device body (1), an opening is formed at the top of the device body (1), a switch door (2) and a switch mechanism (3) are further arranged on the device body (1), the switch door (2) is used to close the opening at the top of the device body (1), the switch mechanism (3) comprises a switch frame (31) and a switch assembly (32), the bottom of the switch frame (31) is rotatably connected with the device body (1), the switch door (2) is arranged on the switch frame (31), and the switch assembly (32) is used to drive the switch frame (31) to rotate.
6. The process for preparing a PZT target according to claim 5, wherein: The device body (1) is further provided with an opening on the side wall, and a maintenance door (4) is arranged on the device body (1), the maintenance door (4) is used for closing the opening on the side wall of the device body (1), and a driving mechanism (5) is further arranged on the device body (1), the driving mechanism (5) is used for driving the maintenance door (4) to displace, so as to cancel the closure of the opening on the side wall of the device body (1).
7. The process for preparing a PZT target according to claim 6, characterized in that: The driving mechanism (5) comprises a driving frame (51), a rotating frame (52) and a linkage assembly (53), the driving frame (51) is in sliding connection with the device body (1) and is in rotary connection with the end of the maintenance door (4), the rotating frame (52) is in sliding connection with the maintenance door (4) and is in rotary connection with the device body (1), and the linkage assembly (53) is used for driving the driving frame (51) to slide.
8. The PZT target preparation process according to claim 7, wherein: The linkage assembly (53) comprises a linkage frame (531), an adaptive frame (532) and a pushing frame (533), one end of the linkage frame (531) is in sliding connection with the switch door (2), the other end is in rotary connection with the adaptive frame (532), the adaptive frame (532) is sleeved on the pushing frame (533) and is in rotary connection with the pushing frame (533), the pushing frame (533) is in sliding connection with the device body (1), the sliding direction of the pushing frame (533) is the same as the sliding direction of the driving frame (51), and the driving frame (51) is located on the sliding path of the pushing frame (533).
9. The PZT target preparation process of claim 5, wherein: The switch door (2) is in sliding connection with the switch frame (31), and the sliding direction of the switch door (2) is the length direction of the switch frame (31), the switch assembly (32) comprises a driving frame (321) and a driving piece (322), one end of the driving frame (321) is in rotary connection with the switch door (2), the other end is in rotary connection with the device body (1), and the driving piece (322) is used for driving the switch frame (31) to rotate.
10. A PZT target prepared by the process of any one of claims 1-9.