A method and system for alternating pulse etching and sidewall protection for TSV and deep trench structures
Patent Information
- Application Number
- CN202610823503.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-09
- Publication Date
- 2026-10-20
Smart Images
Figure FT_1 
Figure FT_2
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor manufacturing technology, specifically to a method and system for alternating pulse etching and sidewall protection of TSV and deep trench structures. Background Technology
[0002] With the rapid development of 3D integrated circuit (3D IC) and microelectromechanical system (MEMS) technologies, through-silicon vias (TSVs) and deep trench structures, as key means to realize vertical interconnection of chips and integration of high-performance devices, are facing increasingly stringent challenges in their manufacturing processes. In particular, during the etching process of high aspect ratio (≥10:1) structures, how to simultaneously achieve high-precision anisotropic etching, perfect sidewall morphology control, and avoid etching damage has become a recognized technical bottleneck in the industry.
[0003] Existing deep silicon etching technologies, such as the Bosch process, typically employ alternating etching and passivation methods. However, traditional processes have the following significant drawbacks:
[0004] 1. Traditional processes often rely on a single fluorocarbon polymer as a sidewall protective layer. In structures with high aspect ratios, it is difficult for the polymer to uniformly cover the bottom of deep holes. At the same time, the ability to actively control the sidewall tilt angle is weak.
[0005] 2. The determination of traditional process parameters often relies on trial and error, which is time-consuming and labor-intensive. It is difficult to quickly select the optimal pulse bias waveform and discharge parameters for a specific structure, thus limiting the efficiency and accuracy of process development.
[0006] 3. Existing process systems generally lack in-situ real-time monitoring of key process parameters (such as the concentration of active species in plasma and the energy distribution of ions reaching the wafer), and even more so, they lack closed-loop adaptive control mechanisms based on monitoring data; when the chamber state or wafer structure undergoes slight changes, process stability is difficult to guarantee, leading to a decrease in etching uniformity and repeatability. Summary of the Invention
[0007] The purpose of this invention is to provide a method and system for alternating pulse etching and sidewall protection for TSV and deep trench structures, so as to solve the problems mentioned in the background art.
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] An alternating pulse etching and sidewall protection method for TSV and deep trench structures includes the following steps:
[0010] S1. Initial process parameter determination: Construct a multi-scale model to simulate the ion etching discharge process and predefine the initial process parameter set for pulse etching and sidewall protection;
[0011] S2. Pulse Etching: An optimized pulse bias waveform, simulated by a multi-scale model, is used to modify the opening shape of silicon vias or deep trench structures through reactive ion etching, and a double protective layer formed by fluorocarbon polymer and oxygen ion irradiation is used to suppress sidewall etching.
[0012] S3. Sidewall protection: Octafluorocyclobutane is used as the sidewall passivation gas. The positive and negative tilt angles of the sidewall morphology are controlled by changing the ratio of etching to passivation cycles, the power of the flat plate electrode, and the flow rate of octafluorocyclobutane.
[0013] S4. Correlation Analysis of Through-Silicon Vias or Deep Trench Structures: Collect key parameters of through-silicon vias or deep trench structures, establish an analytical electric field model, and combine it with computer-aided design simulation verification to monitor and dynamically adjust process parameters during pulse etching and sidewall protection in real time.
[0014] As a further aspect of the present invention: In step S1, the multi-scale model is composed of a reactor chamber model and a sheath hybrid dynamics model, which is used to simulate the ion etching discharge process, analyze and determine the ion energy distribution, ion angle distribution and ion density reaching the lower electrode plate under different pulse bias waveforms and discharge parameter modulations.
[0015] As a further aspect of the present invention: in step S2, a double protective layer is formed in the trace oxygen environment introduced during the etching cycle, and is composed of a fluorocarbon polymer deposition layer and an oxygen ion irradiation layer, which is used to enhance the protection strength of the hole trench sidewall and the selectivity of anisotropic etching.
[0016] As a further aspect of the present invention: in step S4, the electric field analytical model is established based on the two-dimensional charge balance theory, which is used to reveal the intrinsic relationship between the key parameters of the through-silicon via and the key parameters of the deep trench structure and the etching process parameters.
[0017] As a further aspect of the present invention: in step S4, computer-aided design simulation is used to verify the accuracy of the electric field analytical model, and the influence of key parameters on the minimum specific on-resistance under the same etching process conditions is analyzed based on the model and simulation results.
[0018] An alternating pulse etching and sidewall protection system for TSV and deep trench structures includes:
[0019] The plasma reaction chamber has an upper electrode and a lower electrode inside, wherein the lower electrode is connected to the plate electrode power control unit;
[0020] A multi-scale simulation module is used to pre-optimize the pulse bias waveform and discharge parameters;
[0021] The electric field analysis module is used to establish an analytical relationship between etching process parameters and structural parameters based on the two-dimensional charge balance theory and the key parameters of the collected through-silicon via or deep trench structure.
[0022] A multi-channel gas supply system is used to quickly switch between etching gas, sidewall passivation gas and purge gas to support the alternating execution of pulse etching and sidewall protection processes;
[0023] The radio frequency power supply system includes a high-frequency source and an intermediate-frequency pulse source, which are used for plasma generation and bias modulation, respectively.
[0024] In-situ monitoring unit, including optical emission spectrometer and ion energy analyzer;
[0025] The adaptive control unit is used to adjust the process parameters in real time during pulse etching and sidewall protection based on the calculation results of the electric field analytical model and the feedback data from the in-situ monitoring unit.
[0026] As a further embodiment of the present invention: the electric field analysis module includes a key parameter acquisition unit and a two-dimensional charge balance analysis unit, wherein the key parameter acquisition unit is used to acquire key parameters of through-silicon vias or deep trench structures, and the two-dimensional charge balance analysis unit is used to establish the analytical relationship between etching process parameters and structural parameters and output it to the adaptive control unit.
[0027] As a further aspect of the present invention: in the in-situ monitoring unit, an optical emission spectrometer is used to monitor in real time the intensity of fluorine characteristic spectral lines, silicon fluoride characteristic spectral lines and carbon difluoride characteristic spectral lines in the plasma; an ion energy analyzer is used to monitor the ion energy distribution reaching the lower electrode plate.
[0028] As a further aspect of the present invention: the adaptive control unit embeds a closed-loop control algorithm, wherein the implementation steps of the closed-loop control algorithm are as follows:
[0029] When the intensity ratio of the fluorine characteristic spectral line to the carbon difluoride characteristic spectral line monitored by the optical emission spectrometer exceeds a set threshold, the adaptive control unit automatically extends the execution time of the sidewall protection.
[0030] When the ion energy distribution monitored by the ion energy analyzer deviates from the set range, the adaptive control unit automatically adjusts the pulse bias amplitude and pulse duty cycle of the lower electrode.
[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0032] This invention achieves the most concentrated ion energy distribution by using a multi-scale model to simulate and optimize the square wave pulse bias, which significantly improves the directionality of etching. At the same time, by introducing trace amounts of oxygen, a double protective layer composed of a fluorocarbon polymer deposition layer and an oxygen ion irradiation layer is formed during the etching cycle. This effectively improves the density and etching resistance of the sidewall protective layer, greatly suppresses sidewall etching, and ensures the morphological integrity of the high aspect ratio structure.
[0033] By utilizing a multi-scale model that couples the reactor chamber model with the sheath hybrid dynamics model, the ion energy distribution, angle distribution, and ion density under different pulse bias waveforms can be simulated with high precision before the process is executed. This allows for the rapid and scientific determination of the optimal set of initial process parameters, significantly reducing experimental trial and error costs and shortening the process development cycle.
[0034] Based on the two-dimensional charge balance theory, an analytical model of the electric field was established, and combined with computer-aided design simulation verification, a complete analytical link was established from process parameters to structural parameters, and then to the key electrical performance of the device. This guides designers to optimize performance in the early stages of process development, ensuring that the final device not only has a perfect structure, but also excellent electrical performance. Attached Figure Description
[0035] Figure 1 This is a schematic diagram of a process for alternating pulse etching and sidewall protection for TSV and deep trench structures;
[0036] Figure 2 This is a schematic diagram of an alternating pulse etching and sidewall protection system for TSV and deep trench structures. Detailed Implementation
[0037] Please see Figure 1 In this embodiment of the invention, an alternating pulse etching and sidewall protection method and system for TSV and deep trench structures is provided. The alternating pulse etching and sidewall protection method for TSV and deep trench structures includes the following steps:
[0038] S1. Initial process parameter determination: Construct a multi-scale model to simulate the ion etching discharge process and predefine the initial process parameter set for pulse etching and sidewall protection;
[0039] Assuming that when etching a batch of silicon via structures with an aspect ratio of 10:1, the initial set of process parameters includes: square wave pulse bias waveform, 200kHz pulse frequency, 70% pulse duty cycle, 300sccm SF6 flow rate, 30sccm O2 flow rate, and 200sccm C4F8 flow rate.
[0040] Among them, the multi-scale model is composed of a reactor chamber model and a sheath hybrid dynamics model, which is used to simulate the ion etching discharge process, analyze and determine the ion energy distribution, ion angle distribution and ion density reaching the lower electrode plate under different pulse bias waveforms and discharge parameter modulation.
[0041] Assuming that a multi-scale model consisting of a reactor chamber model and a sheath hybrid dynamics model is used to determine the pulse bias waveform, and setting the chamber pressure to 30 mTorr and the RF power to 1500 W, the simulation examines the ion energy distribution reaching the lower electrode plate under different pulse bias waveforms (including square wave, triangular wave, and sine wave). The simulation results are shown below:
[0042] Under square wave pulse bias, the ion energy distribution is most concentrated, with a peak energy of 250 eV, a full width at half maximum (FWHM) of 30 eV, and the ion angle distribution is concentrated in the range of -5° to 5°, with an ion density of 1.2 × 10⁻⁶. 11 cm -3 Based on these simulation results, a square wave pulse bias voltage was selected as the optimized waveform for subsequent etching processes.
[0043] S2. Pulse Etching: An optimized pulse bias waveform, simulated by a multi-scale model, is used to modify the opening shape of silicon vias or deep trench structures through reactive ion etching, and a double protective layer formed by fluorocarbon polymer and oxygen ion irradiation is used to suppress sidewall etching.
[0044] Following the example in step S1, the pulse frequency is 200kHz, the pulse duty cycle is 70%, and the etching gas is a mixture of SF6 and O2, with an SF6 flow rate of 300 scc / min and an O2 flow rate of 30 scc / min; during the pulse off period, Ar is purged at a flow rate of 100 scc / min.
[0045] The lower electrode uses a multi-step pulse bias voltage, wherein the first step pulse bias voltage amplitude is -200V and lasts for 50μs; the second step pulse bias voltage amplitude is -80V and lasts for 30μs.
[0046] During the etching cycle, the introduction of trace amounts of O2 forms a double protective layer consisting of a fluorocarbon polymer deposition layer and an oxygen ion irradiation layer, which effectively protects the sidewalls of the hole groove.
[0047] The double protective layer is formed in the trace oxygen environment introduced during the etching cycle. It is composed of a fluorocarbon polymer deposition layer and an oxygen ion irradiation layer, which is used to enhance the protection strength of the hole trench sidewall and the selectivity of anisotropic etching.
[0048] Assume that during the pulse etching process, a mixed gas of SF6 and O2 is introduced, with an O2 flow rate of 30 sccm; under the action of plasma, the fluorine radicals generated by the decomposition of SF6 perform silicon etching, while the fluorocarbon polymer generated by the decomposition of C4F8 is deposited on the sidewall, and the oxygen ions generated by the decomposition of the introduced O2 irradiate and modify the polymer layer, forming a double protective layer composed of the fluorocarbon polymer deposit layer and the oxygen ion irradiation layer.
[0049] The total thickness of the double protective layer is 50 nm. The oxygen ion irradiation layer increases the polymer density by 30%, which significantly enhances the protection effect on the sidewalls and makes the anisotropic etching selectivity ratio reach 150:1.
[0050] S3. Sidewall protection: Octafluorocyclobutane is used as the sidewall passivation gas. The positive and negative tilt angles of the sidewall morphology are controlled by changing the ratio of etching to passivation cycles, the power of the flat plate electrode, and the flow rate of octafluorocyclobutane.
[0051] Following the example in step S1, the C4F8 flow rate is 200 scc / min, the low-frequency pulse bias voltage of the lower electrode is 10 kHz, the pulse duty cycle is 30%, and the pulse bias voltage amplitude is -100V; the positive and negative tilt angles of the sidewall morphology are controlled by adjusting the time ratio of the etching cycle to the protection cycle.
[0052] S4. Correlation Analysis of Through-Silicon Vias or Deep Trench Structures: Key parameters of through-silicon vias or deep trench structures are collected, an analytical electric field model is established, and computer-aided design simulation is used for verification. Process parameters during pulse etching and sidewall protection are monitored and dynamically adjusted in real time.
[0053] Key parameters for through-silicon vias (TSVs) include: depth, aspect ratio, sidewall roughness, barrier layer thickness and coverage, seed layer thickness and coverage, filler material uniformity, thermal stress and thermal expansion coefficient mismatch, and forbidden zone size. For example, when etching a batch of TSV structures, the key parameters collected include: depth 110 μm, aspect ratio 11:1, target sidewall roughness less than 20 nm, barrier layer thickness 50 nm, barrier layer coverage 98%, seed layer thickness 100 nm, seed layer coverage 97%, filler material uniformity ±5%, thermal stress 120 MPa, thermal expansion coefficient mismatch 2.5 ppm / K, and forbidden zone size 5 μm.
[0054] Key parameters for deep trench structures include: trench depth, trench width, aspect ratio, sidewall perpendicularity, sidewall tilt angle, spacing, doping concentration matching, surface roughness, sidewall roughness, and etching uniformity. For example, when etching a deep trench structure, the key parameters collected include: trench depth 80 μm, trench width 5 μm, aspect ratio 16:1, target sidewall perpendicularity 89.5°, target sidewall tilt angle ±0.5°, spacing 10 μm, doping concentration matching ±5%, target surface roughness 15 nm, target sidewall roughness 20 nm, and target etching uniformity ±3%.
[0055] The electric field analytical model is based on the two-dimensional charge balance theory and is used to reveal the intrinsic relationship between the key parameters of through-silicon vias and deep trench structures and the etching process parameters. The pulse etching process parameters include: radio frequency power, inductively coupled plasma ion source power, cavity pressure, chlorine flow rate, oxygen flow rate, and boron trichloride flow rate.
[0056] Assuming an analytical electric field model is established based on the two-dimensional charge balance theory, the key parameters of the through-silicon via (TSV) collected (such as aspect ratio 11:1, sidewall roughness 20nm) and etching process parameters (such as RF power 1500W, inductively coupled plasma ion source power 2000W, cavity pressure 35mTorr, chlorine flow rate 50sccm, oxygen flow rate 30sccm, boron trichloride flow rate 20sccm) are substituted into the model; the calculation results are shown below:
[0057] Under these process parameters, the charge accumulation density on the sidewalls of the through-silicon via (TSV) is 2.5 × 10⁻⁶. 11 cm -2 The electric field distribution is uniform, and the predicted sidewall verticality is 89.3°, which is within an acceptable range from the target value.
[0058] Among them, computer-aided design simulation is used to verify the accuracy of the electric field analytical model, and based on the model and simulation results, the influence of key parameters on the minimum specific on-resistance under the same etching process conditions is analyzed.
[0059] Assuming that computer-aided design simulation software is used to establish a model with the same process and structural parameters as the analytical electric field model; simulation results show that, under this set of process parameters, the specific on-resistance of the through-silicon via (TSV) structure is 0.85 mΩ·cm. 2 The verticality of the sidewall is 89.2°;
[0060] The simulation results were compared with the calculation results from the analytical electric field model (specific on-resistance 0.86 mΩ·cm). 2 A comparison was made between the two (sidewall verticality 89.3°) and the deviation was less than 2%, verifying the accuracy of the electric field analytical model;
[0061] Further analysis shows that when the aspect ratio increases from 10:1 to 15:1, the minimum specific on-resistance increases by about 18%.
[0062] Please see Figure 2 In this embodiment of the invention, an alternating pulse etching and sidewall protection system for TSV and deep trench structures includes:
[0063] The plasma reaction chamber contains an upper electrode and a lower electrode. The lower electrode is connected to a flat plate electrode power control unit, which can apply a bias voltage of -200V to +50V.
[0064] A multi-scale simulation module is used to pre-optimize the pulse bias waveform and discharge parameters;
[0065] The electric field analysis module is used to establish an analytical relationship between etching process parameters and structural parameters based on two-dimensional charge balance theory and the key parameters of the acquired through-silicon via (TSV) or deep trench structure. Specifically, it includes a key parameter acquisition unit and a two-dimensional charge balance analysis unit. The key parameter acquisition unit acquires key parameters of the TSV or deep trench structure, for example, acquiring the key parameters of the TSV on the current etched wafer: depth 120μm, aspect ratio 12:1, and sidewall roughness 18nm. The two-dimensional charge balance analysis unit establishes the analytical relationship between etching process parameters and structural parameters and outputs it to the adaptive control unit. For example, by substituting the acquired parameters and the current etching process parameters (RF power 1500W, inductively coupled plasma ion source power 1800W, cavity pressure 30mTorr) into the electric field analysis model, the expected sidewall perpendicularity is calculated to be 89.5° and the minimum specific on-resistance is 0.82mΩ·cm. 2 The analytical relationship is then output to the adaptive control unit as the basis for process adjustment.
[0066] A multi-channel gas supply system is used to quickly switch between etching gas, sidewall passivation gas, and purge gas to support the alternating execution of pulse etching and sidewall protection processes, such as completing the switching within 30ms; wherein, the etching gas includes a mixture of SF6 and O2, the sidewall passivation gas is C4F8, and the purge gas is Ar;
[0067] The radio frequency power supply system includes a high-frequency source and an intermediate-frequency pulse source, which are used for plasma generation and bias modulation, respectively, such as a 13.56MHz high-frequency source and a 400kHz intermediate-frequency pulse source;
[0068] The in-situ monitoring unit includes an optical emission spectrometer and an ion energy analyzer; the optical emission spectrometer is used to monitor the intensity of fluorine characteristic spectral lines, silicon fluoride characteristic spectral lines and carbon difluoride characteristic spectral lines in the plasma in real time; the ion energy analyzer is used to monitor the ion energy distribution reaching the lower electrode plate.
[0069] Assuming that during the etching process, an optical emission spectrometer monitors the plasma spectrum in real time and detects the characteristic spectral line wavelengths of fluorine (703.7 nm), silicon fluoride (440.2 nm), and carbon difluoride (321.3 nm), and that when the ratio of the intensity of the fluorine characteristic spectral line to that of the carbon difluoride characteristic spectral line is 1.5, it indicates that the etching intensity is moderate; when this ratio rises to 2.2, it indicates that the etching is too strong, triggering a prolonged sidewall protection process.
[0070] The ion energy analyzer monitors the ion energy distribution reaching the lower electrode plate, showing that high-energy ions (>200eV) account for 35% and the peak ion energy is 210eV. The data is transmitted to the adaptive control unit in real time.
[0071] The adaptive control unit is used to adjust the process parameters in real time during pulse etching and sidewall protection based on the calculation results of the electric field analytical model and the feedback data from the in-situ monitoring unit. It incorporates a closed-loop control algorithm, the implementation steps of which are as follows:
[0072] When the intensity ratio of the fluorine characteristic spectral line to the carbon difluoride characteristic spectral line monitored by the optical emission spectrometer exceeds a set threshold, the adaptive control unit automatically extends the execution time of the sidewall protection. For example, when the optical emission spectrometer detects that the intensity ratio of the fluorine characteristic spectral line to the carbon difluoride characteristic spectral line increases from the set threshold of 1.8 to 2.2, the adaptive control unit automatically extends the execution time of the current sidewall protection process from 2 seconds to 2.4 seconds, so that the intensity ratio is restored to 1.9.
[0073] When the ion energy distribution monitored by the ion energy analyzer deviates from the set range, the adaptive control unit automatically adjusts the pulse bias amplitude and pulse duty cycle of the lower electrode. For example, when the ion energy analyzer detects that the proportion of high-energy ions (>200eV) in the ion energy distribution increases from the set range of 35%±5% to 48%, the adaptive control unit automatically adjusts the pulse bias amplitude of the lower electrode from -200V to -180V, and at the same time adjusts the pulse duty cycle from 70% to 65%, so that the proportion of high-energy ions is restored to 36%.
[0074] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A method for alternating pulse etching and sidewall protection for TSV and deep trench structures, characterized in that, Includes the following steps: S1. Initial process parameter determination: Construct a multi-scale model to simulate the ion etching discharge process and predefine the initial process parameter set for pulse etching and sidewall protection; S2. Pulse Etching: An optimized pulse bias waveform, simulated by a multi-scale model, is used to modify the opening shape of silicon vias or deep trench structures through reactive ion etching, and a double protective layer formed by fluorocarbon polymer and oxygen ion irradiation is used to suppress sidewall etching. S3. Sidewall protection: Octafluorocyclobutane is used as the sidewall passivation gas. The positive and negative tilt angles of the sidewall morphology are controlled by changing the ratio of etching to passivation cycles, the power of the flat plate electrode, and the flow rate of octafluorocyclobutane. S4. Correlation Analysis of Through-Silicon Vias or Deep Trench Structures: Collect key parameters of through-silicon vias or deep trench structures, establish an analytical electric field model, and combine it with computer-aided design simulation verification to monitor and dynamically adjust process parameters during pulse etching and sidewall protection in real time.
2. The method for alternating pulse etching and sidewall protection for TSV and deep trench structures according to claim 1, characterized in that, In step S1, the multi-scale model is composed of a reactor chamber model and a sheath hybrid dynamics model, which is used to simulate the ion etching discharge process, analyze and determine the ion energy distribution, ion angle distribution and ion density reaching the lower electrode plate under different pulse bias waveforms and discharge parameter modulations.
3. The method for alternating pulse etching and sidewall protection for TSV and deep trench structures according to claim 1, characterized in that, In step S2, a double protective layer is formed in the trace oxygen environment introduced during the etching cycle. It is composed of a fluorocarbon polymer deposition layer and an oxygen ion irradiation layer, and is used to enhance the protection strength of the hole trench sidewalls and the selectivity of anisotropic etching.
4. The method for alternating pulse etching and sidewall protection for TSV and deep trench structures according to claim 1, characterized in that, In step S4, the electric field analytical model is established based on the two-dimensional charge balance theory to reveal the intrinsic relationship between key parameters of through-silicon vias and deep trench structures and etching process parameters.
5. The method for alternating pulse etching and sidewall protection for TSV and deep trench structures according to claim 1, characterized in that, In step S4, computer-aided design simulation is used to verify the accuracy of the electric field analytical model, and the influence of key parameters on the minimum specific on-resistance under the same etching process conditions is analyzed based on the model and simulation results.
6. An alternating pulse etching and sidewall protection system for the method of any one of claims 1-5, characterized in that, include: The plasma reaction chamber has an upper electrode and a lower electrode inside, wherein the lower electrode is connected to the plate electrode power control unit; A multi-scale simulation module is used to pre-optimize the pulse bias waveform and discharge parameters; The electric field analysis module is used to establish an analytical relationship between etching process parameters and structural parameters based on the two-dimensional charge balance theory and the key parameters of the collected through-silicon via or deep trench structure. A multi-channel gas supply system is used to quickly switch between etching gas, sidewall passivation gas and purge gas to support the alternating execution of pulse etching and sidewall protection processes; The radio frequency power supply system includes a high-frequency source and an intermediate-frequency pulse source, which are used for plasma generation and bias modulation, respectively. In-situ monitoring unit, including optical emission spectrometer and ion energy analyzer; The adaptive control unit is used to adjust the process parameters in real time during pulse etching and sidewall protection based on the calculation results of the electric field analytical model and the feedback data from the in-situ monitoring unit.
7. The alternating pulse etching and sidewall protection system for TSV and deep trench structures according to claim 6, characterized in that, The electric field analysis module includes a key parameter acquisition unit and a two-dimensional charge balance analysis unit. The key parameter acquisition unit is used to acquire key parameters of through-silicon vias or deep trench structures, and the two-dimensional charge balance analysis unit is used to establish the analytical relationship between etching process parameters and structural parameters and output it to the adaptive control unit.
8. The alternating pulse etching and sidewall protection system for TSV and deep trench structures according to claim 6, characterized in that, In the in-situ monitoring unit, an optical emission spectrometer is used to monitor the intensity of fluorine characteristic spectral lines, silicon fluoride characteristic spectral lines, and carbon difluoride characteristic spectral lines in the plasma in real time; an ion energy analyzer is used to monitor the ion energy distribution reaching the lower electrode plate.
9. The alternating pulse etching and sidewall protection system for TSV and deep trench structures according to claim 6, characterized in that, The adaptive control unit incorporates a closed-loop control algorithm, the implementation steps of which are as follows: When the intensity ratio of the fluorine characteristic spectral line to the carbon difluoride characteristic spectral line monitored by the optical emission spectrometer exceeds a set threshold, the adaptive control unit automatically extends the execution time of the sidewall protection. When the ion energy distribution monitored by the ion energy analyzer deviates from the set range, the adaptive control unit automatically adjusts the pulse bias amplitude and pulse duty cycle of the lower electrode.