Deep etching method combining dynamic dry-wet method of film lead zirconate titanate

Abstract

The invention provides a film lead zirconate titanate dynamic dry and wet combined deep etching method, relates to the technical field of photoelectric integration, and is used for solving the problem that high side wall steepness and smooth side wall of film lead zirconate titanate cannot be realized in the existing etching technology. Comprising the following steps: depositing a chromium metal film layer on a film lead zirconate titanate substrate; coating a first photoresist on one side of the chromium metal film layer to obtain a first photoresist layer; performing pattern exposure and development operation on the first photoresist layer to obtain a second photoresist layer; etching the chromium metal film layer along the second photoresist layer to obtain a chromium mask layer; etching the film lead zirconate titanate substrate along the chromium mask layer by alternately adopting a dry etching gas and a wet cleaning solution to obtain a film lead zirconate titanate micro-nano structure; and carrying out etching post-processing to obtain the film lead zirconate titanate device. According to the method, high-quality and high-efficiency etching of the film lead zirconate titanate is realized through a dynamic dry and wet combined etching method in which dry etching and wet cleaning are alternated.

Description

Technical Field

[0001] The invention relates to the technical field of optoelectronic integration technology, and in particular to a deep etching method combining dynamic dry and wet methods for thin-film lead zirconate titanate. Background Art

[0002] In the field of optoelectronic integration technology, lead zirconate titanate (Pb(Zr,Ti)O3, PZT), as a perovskite-type multifunctional oxide, has become a key candidate material in the new generation of functional material systems because of its piezoelectricity, ferroelectricity, electro-optical effect, acousto-optical effect and nonlinear optical properties. The most significant technical advantage of this material is its excellent electro-optical response characteristics. Experimental determination shows that its effective Pockels coefficient can exceed 100 pm / V, which means that a more significant refractive index modulation effect can be produced under the same driving voltage, thereby achieving more energy-efficient optical signal control. Based on the outstanding electro-optical coefficient and wide spectral response characteristics, the PZT material system is regarded as an ideal material for building a new generation of integrated optoelectronic devices in integrated optoelectronic components such as optical phase modulators and waveguide couplers, especially in the application scenarios of optical interconnection and on-chip optical communication systems. Through the continuous innovation of thin film preparation technology and device architecture, the industrial application of PZT-based optoelectronic devices in high-speed, large-bandwidth optical transmission systems has shown clear technical feasibility. It is worth emphasizing that thin film PZT not only completely retains the intrinsic properties of bulk materials, but also shows a high degree of compatibility with standard CMOS processes. This makes the graphical etching technology of PZT thin films a key process link in realizing the industrialization of high-performance thin film devices.

[0003] At present, the main etching schemes for lead zirconate titanate include fluorine-based gas etching, physical etching with argon ions, and wet etching. However, due to the hard material properties and stable physical and chemical properties of lead zirconate titanate itself, coupled with the demand for miniaturization, high resolution, high-quality and efficient processing in recent years, the current etching methods are always difficult to meet. On the one hand, fluorine-based gas etching is easy to produce etching byproducts with the film to form an etching barrier layer, which limits deep etching, reduces efficiency, increases sidewall roughness and affects etching selectivity; on the other hand, although the physical etching scheme using argon ions can effectively improve the sidewall tilt angle and roughness, it is difficult to provide good etching selectivity and etching efficiency. Long-term etching may damage the film, so it is difficult to achieve deep etching. With wet etching, the etching anisotropy is poor, and the etching process cannot be well controlled, making it difficult to meet the requirements of size and precision. In addition, deep etching often uses thicker photoresists, which are prone to photoresist drift and glue collapse during etching. This is because the adhesion between the thin film lead zirconate titanate and the photoresist is not strong, and the aspect ratio of the pattern is large.

[0004] Therefore, in order to realize high-quality thin-film lead zirconate titanate waveguides, microrings, gratings and other optical structures, how to effectively improve the side wall roughness, improve the etching efficiency, obtain a smooth etched surface, and achieve deep etching with high side wall steepness has become an urgent problem to be solved. Summary of the invention

[0005] In view of the above problems, an embodiment of the present invention provides a deep etching method for a lead zirconate titanate thin film by combining a dynamic dry-wet process.

[0006] The invention provides an etching method for a thin-film lead zirconate titanate device, comprising: providing a thin-film lead zirconate titanate substrate to be etched; depositing a chromium metal thin film layer on the thin-film lead zirconate titanate substrate; coating a first photoresist on a side of the chromium metal thin film layer away from the thin-film lead zirconate titanate substrate to form a first photoresist layer; performing pattern exposure and development operations on the first photoresist layer to obtain a second photoresist layer; etching the chromium metal thin film layer along the second photoresist layer to obtain a chromium mask layer; alternately using dry etching gas and wet cleaning solution to etch the thin-film lead zirconate titanate substrate along the chromium mask layer to obtain an expected thin-film lead zirconate titanate micro-nano structure; performing post-etching treatment on the expected thin-film lead zirconate titanate micro-nano structure to obtain a thin-film lead zirconate titanate device.

[0007] According to an embodiment of the present invention, a thin film lead zirconate titanate substrate is etched along a chromium mask layer by alternating dry etching gas and a wet cleaning solution to obtain an expected thin film lead zirconate titanate micro-nano structure, including: performing inductively coupled plasma etching on the thin film lead zirconate titanate substrate along the chromium mask layer using a dry etching gas to generate a solid deposit, and the solid deposit is accumulated on the surface of the thin film lead zirconate titanate substrate to form an etching barrier layer; performing wet cleaning on the thin film lead zirconate titanate substrate along the etching barrier layer using a wet cleaning solution to remove the etching barrier layer; and repeatedly etching the thin film lead zirconate titanate substrate using a dry etching gas and a wet cleaning solution in turn to obtain the expected thin film lead zirconate titanate micro-nano structure.

[0008] According to an embodiment of the present invention, a thin film lead zirconate titanate substrate includes: a thin film lead zirconate titanate layer, a silicon dioxide lower cladding layer and a silicon substrate.

[0009] According to an embodiment of the present invention, performing a pattern exposure and development operation on the first photoresist layer to obtain a second photoresist layer includes: pre-baking the first photoresist layer; transferring the target pattern to the first photoresist layer by an exposure operation; and performing a development and hardening operation on the first photoresist layer along the target pattern to obtain a second photoresist layer.

[0010] According to an embodiment of the present invention, the first photoresist includes electron beam resist, and transferring the target pattern to the first photoresist layer by using an exposure operation includes: transferring the target pattern to the electron beam resist layer by using an electron beam exposure operation.

[0011] According to an embodiment of the present invention, the dry etching gas includes argon and trifluoromethane.

[0012] According to an embodiment of the present invention, the wet cleaning solution is obtained by mixing hydrogen peroxide, ammonia water and deionized water in equal volume ratios.

[0013] According to an embodiment of the present invention, the expected thin film lead zirconate titanate micro-nano structure is subjected to post-etching processing to obtain a thin film lead zirconate titanate device, including: immersing the expected thin film lead zirconate titanate micro-nano structure in a chromium removal agent, cleaning off the chromium mask remaining on the surface, and obtaining a thin film lead zirconate titanate device.

[0014] According to an embodiment of the present invention, the etching depth of the thin film lead zirconate titanate device is greater than 300 nm, and the side wall inclination angle of the thin film lead zirconate titanate device is greater than 75°.

[0015] According to an embodiment of the present invention, a plurality of grooves are provided on one side of the thin film lead zirconate titanate device along a preset tilt angle, and the depth of the grooves is less than the thickness of the thin film lead zirconate titanate layer.

[0016] The present invention realizes high-quality and high-efficiency etching of thin-film lead zirconate titanate through a dynamic etching process that alternately combines dry etching gas and wet cleaning solution dry and wet etching, thereby solving the problem that the prior art cannot perform deep etching of thin-film lead zirconate titanate with high side wall steepness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0018] Figure 1 A flowchart of a deep etching method for a thin film lead zirconate titanate using a dynamic dry-wet method combined with a wet-dry method is schematically shown according to an embodiment of the present invention;

[0019] Figure 2 Schematically showing the structural diagram of each stage of the deep etching method of thin film lead zirconate titanate by dynamic dry and wet method combination according to an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a waveguide cross-section of a thin-film lead zirconate titanate device manufactured according to a method of an embodiment of the present invention is shown;

[0021] Figure 4 The waveguide sidewall morphology of the thin film lead zirconate titanate device prepared according to the method of the embodiment of the present invention is schematically shown;

[0022] Figure 5 A schematic diagram of a thin film lead zirconate titanate device manufactured according to a method of an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0024] It should be noted that in the drawings or descriptions, similar or identical parts use the same figure numbers. The technical features in the various embodiments exemplified in the specification can be freely combined to form new solutions without conflict, and in the drawings, the shape or thickness of the embodiments can be expanded and simplified or conveniently indicated. Furthermore, the elements or implementations not shown or described in the drawings are in a form known to ordinary technicians in the relevant technical field. In addition, although demonstrations of parameters containing specific values ​​may be provided herein, it should be understood that the parameters do not need to be exactly equal to the corresponding values, but can be approximated to the corresponding values ​​within an acceptable error tolerance or design constraint.

[0025] Unless there are technical obstacles or contradictions, the above-mentioned various embodiments of the present invention can be freely combined to form other embodiments, and these other embodiments are all within the protection scope of the present invention.

[0026] Although the present invention is described in conjunction with the accompanying drawings, the embodiments disclosed in the drawings are intended to exemplify the preferred embodiments of the present invention and should not be construed as limiting the present invention. The size ratios in the drawings are merely illustrative and should not be construed as limiting the present invention.

[0027] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general disclosed concept.

[0028] Figure 1 The flowchart of the deep etching method of the thin film lead zirconate titanate using a dynamic dry-wet combination method according to an embodiment of the present invention is schematically shown.

[0029] like Figure 1 As shown, an embodiment of the present invention provides a deep etching method for a lead zirconate titanate thin film by combining a dynamic dry-wet process, including operations S110 to S170.

[0030] In operation S110, a thin film lead zirconate titanate substrate to be etched is provided.

[0031] For example, a thin film lead zirconate titanate substrate (hereinafter referred to as the substrate) to be etched with a size of 2cm*2cm can be obtained, and the substrate structure from bottom to top can be a silicon bottom of 720um, a silicon dioxide lower cladding of 2um, and a thin film lead zirconate titanate layer of 330nm. The substrate is then cleaned, for example, by ultrasonic cleaning the substrate with acetone and ethanol for five minutes in sequence, and then drying it with a nitrogen gun.

[0032] In operation S120, a chromium metal thin film layer is deposited on the thin film lead zirconate titanate substrate.

[0033] The embodiment of the present invention uses chromium as a hard mask. Masks commonly used in etching include electron beam photoresist masks, dielectric hard masks (such as silicon dioxide) and metal hard masks.

[0034] Conventional electron beam photoresist etching has a low selectivity and a fast consumption rate. During the etching process of deeper thickness, it is easy to cause floating and collapse due to the large aspect ratio, which is not conducive to deep etching. The selectivity of dielectric masks such as silicon dioxide is not good enough, and it is easy to react with fluorine gases, so it is consumed quickly, and it is difficult to achieve the corresponding deep etching requirements; using chromium as a metal hard mask is not easy to react with fluorine gases, the selectivity of the etching process is greatly improved, and there will be no collapse during the etching process. Therefore, it is a very effective way to achieve deep etching with high steepness.

[0035] For example, a 250 nm chromium metal layer may be deposited on the cleaned substrate by metal evaporation equipment, wherein the chromium is deposited by metal evaporation as a hard mask layer with a thickness of 150-300 nm, preferably 220-270 nm.

[0036] In operation S130, a first photoresist is coated on a side of the chromium metal thin film layer away from the lead zirconate titanate thin film substrate to form a first photoresist layer.

[0037] For example, a first photoresist layer may be spin-coated on the chromium metal layer using a spin coater.

[0038] In operation S140, the first photoresist layer is subjected to pattern exposure and development operations to obtain a second photoresist layer.

[0039] The pattern to be etched is transferred to the first photoresist layer through a pattern development operation to obtain a second photoresist layer.

[0040] In operation S150, the chromium metal film layer is etched along the second photoresist layer to obtain a chromium mask layer.

[0041] For etching of the chromium metal film layer, the selected etching machine has a set of mature high-selectivity etching solutions. Then, the residual photoresist is removed by soaking in a debonding agent for, for example, 10 minutes to obtain a metal chromium mask layer.

[0042] In operation S160, the thin film lead zirconate titanate substrate is etched along the chromium mask layer by alternately using dry etching gas and wet cleaning solution to obtain the desired thin film lead zirconate titanate micro-nano structure.

[0043] For example, before etching, the ICP (Inductively Coupled Plasma) equipment can be pre-treated and cleaned to prevent chamber contamination from having a destructive effect on the etching process. The power range of the ICP equipment is 200W-1100W, preferably 250-350W, the RF power (Radio Frequency Power) ranges from 30W-500W, preferably 100W-200W, the working chamber pressure is 0.5-10Pa, preferably 0.5-1Pa, and the working chamber is 0℃-80℃, preferably 5-25℃.

[0044] After that, the thin film lead zirconate titanate substrate is sent to the ICP equipment to etch the thin film lead zirconate titanate. For example, argon and trifluoromethane are selected as dry etching gases, where argon is 26sccm, trifluoromethane is 12sccm, ICP power is selected to be 350W, RF power is set to 130W, the working chamber is set to 20°C, the chamber pressure is 0.6pa, etching is 130s, and the sample is immersed in a wet cleaning solution of equal volume ratio of hydrogen peroxide, ammonia water and deionized water to maintain 80°C for wet cleaning to produce etching byproducts, the dry etching rate is 40nm / min, and the final etching depth is 300nm.

[0045] In operation S170, the desired thin film lead zirconate titanate micro-nano structure is subjected to post-etching treatment to obtain a thin film lead zirconate titanate device.

[0046] The specific operation steps of the embodiment of the present invention will be further described below.

[0047] Figure 2 (a) ~ Figure 2 (h) schematically shows the structure of various stages of the deep etching method of the thin film lead zirconate titanate using a dynamic dry-wet combination method according to an embodiment of the present invention.

[0048] like Figure 2 As shown in (a), the thin film lead zirconate titanate substrate used is composed of a silicon substrate, a silicon oxide lower cladding layer and a thin film lead zirconate titanate layer. It is cleaned before etching to remove surface impurities.

[0049] like Figure 2 As shown in (b), after the substrate is processed, a chromium metal thin film layer can be deposited on one side of the lead zirconate titanate thin film layer using, for example, a metal evaporation device.

[0050] like Figure 2 As shown in (c), a first photoresist layer is spin-coated on the chromium metal layer.

[0051] like Figure 2 (d) and Figure 2As shown in (e), for example, an electron beam can be used to expose the first photoresist layer along the pattern to be etched, and then it is developed and hardened to obtain a second photoresist layer, thus completing a transfer of the pattern.

[0052] like Figure 2 As shown in (f), the chromium metal layer is etched along the second photoresist layer, and the remaining second photoresist layer is removed with a debonding agent, thereby obtaining a chromium mask after the second transfer of the pattern.

[0053] like Figure 2 As shown in (g), the substrate is placed in an ICP etching device, and etching gas is first introduced for chemical and physical etching. The substrate is then immersed in a wet cleaning solution of equal volume ratios of hydrogen peroxide, ammonia water and deionized water and maintained at 80°C for wet cleaning to remove the etching by-products.

[0054] like Figure 2 As shown in (h), the substrate is immersed in a chromium remover to clean off the chromium mask remaining on the surface to obtain a thin film lead zirconate titanate device.

[0055] The embodiments of the present invention achieve high-quality and high-efficiency etching of thin-film lead zirconate titanate through a dynamic dry-wet etching process that alternately combines dry etching gas and wet cleaning solution, thereby solving the problem that the prior art cannot perform deep etching of thin-film lead zirconate titanate with high sidewall steepness.

[0056] According to an embodiment of the present invention, a thin film lead zirconate titanate substrate is etched along a chromium mask layer by alternating dry etching gas and a wet cleaning solution to obtain an expected thin film lead zirconate titanate micro-nano structure, including: performing inductively coupled plasma etching on the thin film lead zirconate titanate substrate along the chromium mask layer using a dry etching gas to generate a solid deposit, and the solid deposit accumulates on the surface of the thin film lead zirconate titanate substrate to form an etching barrier layer; performing wet cleaning on the thin film lead zirconate titanate substrate along the etching barrier layer using a wet cleaning solution to remove the etching barrier layer; and repeatedly etching the thin film lead zirconate titanate substrate using a dry etching gas and a wet cleaning solution in turn to obtain the expected thin film lead zirconate titanate micro-nano structure.

[0057] The main purpose of using dry etching gas for chemical and physical etching is to improve the etching efficiency and etching selectivity. This process easily produces solid deposits attached to the etching surface. Analysis and speculation show that the deposits are lead difluoride, titanium trifluoride and zirconium tetrafluoride, which have boiling points of 1293°C, 1400°C and 905°C, respectively. They are not easy to volatilize, and are more likely to accumulate and block etching in the case of narrow line width etching. Therefore, the wet process of the embodiment of the present invention is used for cleaning. When the barrier layer is initially formed, a wet cleaning solution with equal volume ratios of hydrogen peroxide, ammonia water and deionized water is used to maintain the solution temperature at 80°C to clean the etched substrate, which can remove the attached solid deposits in time and greatly improve the inclination angle and smoothness of the overall side wall.

[0058] In some embodiments, argon and trifluoromethane can be used for etching first, and some gas products are generated and discharged, while some solid deposits are generated to form an etching barrier layer on the etching surface, and the etching time is 100-200s, preferably 120-150s. Hydrogen peroxide, ammonia water and deionized water are mixed in a volume ratio of 1:1:1 to obtain a wet cleaning solution. The temperature is maintained at 80°C for wet cleaning for 5-15min, preferably 6-9min, and this is repeated 3 times to complete the etching of the substrate.

[0059] The embodiment of the present invention adopts a dynamic dry-wet etching process that alternates dry etching and wet cleaning. By repeatedly alternating the dry etching gas and the wet cleaning solution, the good anisotropy is utilized to obtain a steep etching sidewall. The combination of the two achieves high-quality and high-efficiency etching of thin-film lead zirconate titanate.

[0060] According to an embodiment of the present invention, a thin film lead zirconate titanate substrate includes: a thin film lead zirconate titanate layer, a silicon dioxide lower cladding layer and a silicon substrate.

[0061] In some embodiments, the thin film lead zirconate titanate substrate may be, for example, a thin film lead zirconate titanate wafer including a 330 nm thick thin film lead zirconate titanate layer, a 2 um thick silicon dioxide lower cladding layer, and a 720 um thick silicon substrate.

[0062] According to an embodiment of the present invention, the thickness of the thin film lead zirconate titanate layer is 330 nm.

[0063] In the field of integrated optoelectronic devices, lead zirconate titanate (Pb(ZrxTi1-x)O 3 As a multifunctional perovskite oxide, PZT (Pyrolytic Zinc Titanium) combines piezoelectricity, ferroelectricity, electro-optical effect, acousto-optic effect and nonlinear optical properties, and is regarded as one of the core candidates for a new generation of functional materials.

[0064] Thin film lead zirconate titanate not only inherits the excellent properties of bulk lead zirconate titanate, but is also compatible with the metal oxide semiconductor manufacturing process. Therefore, etching of thin film lead zirconate titanate is very important.

[0065] The embodiment of the present invention can achieve deep etching of the lead zirconate titanate thin film through a dynamic dry-wet etching process that alternately combines dry etching and wet cleaning.

[0066] According to an embodiment of the present invention, performing an exposure and development operation on a first photoresist layer to obtain a second photoresist layer includes: pre-baking the first photoresist layer. Transferring a target pattern to the first photoresist layer by an exposure operation. Performing a development and hardening operation on the first photoresist layer along the target pattern to obtain a second photoresist layer to which the target pattern is transferred.

[0067] The embodiment of the present invention performs two pattern transfers to obtain a chrome mask. First, a first photoresist layer is spin-coated on the chrome metal layer and pre-baked, and then electron beam exposure, development and hardening are performed to obtain a pattern after a single transfer. At the same time, there is a mature solution for etching metal chrome on this platform, so etching chrome can achieve a secondary transfer of the pattern, thereby obtaining a chrome mask.

[0068] The second photoresist layer is obtained by performing pattern exposure and development operations on the first photoresist layer, and the chromium metal film layer is etched along the second photoresist layer to achieve pattern transfer to obtain a chromium mask, which is conducive to deep etching of a thin film lead zirconate titanate substrate.

[0069] According to an embodiment of the present invention, the first photoresist layer includes an electron beam colloid layer, and transferring the target pattern to the first photoresist layer by using an exposure operation includes: transferring the target pattern to the electron beam colloid layer by using an electron beam exposure operation.

[0070] In some embodiments, for example, electron beam glue may be used as the first photoresist, and an electron beam exposure operation may be used to transfer the target pattern to the electron beam glue layer.

[0071] Electron beam lithography is a high-resolution graphic technology that uses a focused electron beam to directly draw nanoscale patterns on electron beam glue. It has the advantages of ultra-high resolution and high flexibility. It can achieve precise drawing of the pattern to be etched.

[0072] According to an embodiment of the present invention, the dry etching gas includes argon and trifluoromethane.

[0073] According to an embodiment of the present invention, the wet cleaning solution is obtained by mixing hydrogen peroxide, ammonia water and deionized water in equal volume ratios.

[0074] In some embodiments, argon in the dry etching gas is the main etching gas, and the anisotropy of etching is improved by bombardment of argon ions, and trifluoromethane helps to improve the selectivity of etching and form a protective layer on the sidewall to achieve high anisotropy etching. For example, the concentrations of argon and trifluoromethane in the dry etching gas are balanced to maintain a reasonable etching rate and avoid a decrease in the selectivity.

[0075] According to an embodiment of the present invention, the expected thin film lead zirconate titanate micro-nano structure is subjected to post-etching processing to obtain a thin film lead zirconate titanate device, including: immersing the expected thin film lead zirconate titanate micro-nano structure in a chromium remover, cleaning off the chromium mask remaining on the surface, and obtaining the thin film lead zirconate titanate device.

[0076] In some embodiments, for example, the desired thin film lead zirconate titanate micro-nano structure can be immersed in a chromium remover to remove the residual chromium mask on the surface.

[0077] By cleaning the etched thin film lead zirconate titanate substrate, etching byproducts can be effectively removed and the performance of thin film lead zirconate titanate devices can be improved.

[0078] Figure 3 The waveguide cross-section of a thin-film lead zirconate titanate device manufactured according to the method of an embodiment of the present invention is schematically shown. Figure 4 The waveguide sidewall morphology of a thin film lead zirconate titanate device manufactured according to the method of an embodiment of the present invention is schematically shown. Figure 5 A schematic diagram of a thin film lead zirconate titanate device manufactured according to a method of an embodiment of the present invention is shown.

[0079] According to an embodiment of the present invention, the etching depth of the thin film lead zirconate titanate device is greater than or equal to 300 nm, and the side wall inclination angle of the thin film lead zirconate titanate device is greater than or equal to 75°.

[0080] like Figure 3 , Figure 4 and Figure 5 As shown in the figure, a thin film lead zirconate titanate device is prepared by using the thin film lead zirconate titanate etching method provided by the embodiment of the present invention. The etching depth achieved is 300nm, the etching slope is 75°, and the overall side wall after etching is smooth, ultimately achieving the purpose of high-efficiency and high-quality deep etching.

[0081] Preferably, the etching depth of the thin film lead zirconate titanate device is 250nm-320nm, and the side wall inclination angle is 70-80°.

[0082] According to an embodiment of the present invention, a plurality of grooves are provided on one side of the thin film lead zirconate titanate device along a preset tilt angle, and the depth of the grooves is less than the thickness of the thin film lead zirconate titanate layer.

[0083] In some embodiments, the groove depth is the etching depth of the thin film lead zirconate titanate device, and the etching depth should be less than the thickness of the thin film lead zirconate titanate layer.

[0084] It is understood that the specific order or hierarchy of steps in the processes disclosed is an example of exemplary approaches. Based on design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged without departing from the scope of the present invention.

[0085] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted when they may cause confusion in the understanding of the present invention. In addition, the shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual sizes, proportions, and actual positional relationships.

[0086] In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. With respect to the term "comprising" used in the specification, the word is covered in a manner similar to the term "including", as explained by "including," used as a transitional word. Any term "or" used in the specification is intended to mean "non-exclusive or".

[0087] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A deep etching method for thin film lead zirconate titanate by dynamic dry and wet method, characterized in that: include: Providing a thin film lead zirconate titanate substrate to be etched; Depositing a chromium metal thin film layer on the thin film lead zirconate titanate substrate; Coating a first photoresist on a side of the chromium metal thin film layer away from the thin film lead zirconate titanate substrate to form a first photoresist layer; Performing pattern exposure and development operations on the first photoresist layer to obtain a second photoresist layer; Etching the chromium metal film layer along the second photoresist layer to obtain a chromium mask layer; Alternatingly using dry etching gas and wet cleaning solution to etch the thin film lead zirconate titanate substrate along the chromium mask layer to obtain the expected thin film lead zirconate titanate micro-nano structure; The expected thin film lead zirconate titanate micro-nano structure is subjected to post-etching treatment to obtain a thin film lead zirconate titanate device.

2. The method according to claim 1, characterized in that Alternately using dry etching gas and wet cleaning solution, the thin film lead zirconate titanate substrate is etched along the chromium mask layer to obtain the expected thin film lead zirconate titanate micro-nano structure including: Using the dry etching gas to perform inductively coupled plasma etching on the thin film lead zirconate titanate substrate along the chromium mask layer to generate solid deposits, wherein the solid deposits are accumulated on the surface of the thin film lead zirconate titanate substrate to form an etching barrier layer; Using the wet cleaning solution to wet clean the thin film lead zirconate titanate substrate along the etch barrier layer to remove the etch barrier layer; The thin film lead zirconate titanate substrate is repeatedly etched using the dry etching gas and the wet cleaning solution in sequence to obtain the expected thin film lead zirconate titanate micro-nano structure.

3. The method according to claim 1, characterized in that The thin film lead zirconate titanate substrate comprises: a thin film lead zirconate titanate layer, a silicon dioxide lower cladding layer and a silicon substrate.

4. The method according to claim 1, characterized in that: The step of performing pattern exposure and development operations on the first photoresist layer to obtain a second photoresist layer comprises: Pre-baking the first photoresist layer; Transferring the target pattern to the first photoresist layer by an exposure operation; The first photoresist layer is subjected to a development and hardening operation to obtain a second photoresist layer to which the target pattern is transferred.

5. The method according to claim 4, characterized in that The first photoresist layer includes electron beam glue, and the step of transferring the target pattern to the first photoresist layer by using an exposure operation includes: The target pattern is transferred to the electron beam adhesive layer by electron beam exposure operation.

6. The method according to claim 1, characterized in that The dry etching gas includes argon and trifluoromethane.

7. The method according to claim 1, characterized in that The wet cleaning solution is obtained by mixing hydrogen peroxide, ammonia water and deionized water in equal volume ratios.

8. The method according to claim 1, characterized in that The etching and post-processing of the expected thin film lead zirconate titanate micro-nano structure to obtain a thin film lead zirconate titanate device comprises: The expected thin-film lead zirconate titanate micro-nano structure is immersed in a chromium removal agent to clean off the chromium mask remaining on the surface, thereby obtaining the thin-film lead zirconate titanate device.

9. The method according to claim 1, characterized in that: The etching depth of the thin film lead zirconate titanate device is greater than or equal to 250nm, and the side wall inclination angle of the thin film lead zirconate titanate device is greater than or equal to 70°.

10. The method according to claim 3, characterized in that A plurality of grooves are provided on one side of the thin film lead zirconate titanate device along a preset tilt angle, and the depth of the grooves is less than the thickness of the thin film lead zirconate titanate layer.

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