Apparatus and method for preparing and cleaning a component

Abstract

The present invention provides an apparatus for cleaning a component supplied in a lithography device, the apparatus comprising at least one cleaning module or a plurality of cleaning modules, wherein the at least one cleaning module or the plurality of cleaning modules comprises a plurality of cleaning mechanisms, and wherein the plurality of cleaning mechanisms comprises: at least one preparation mechanism for reducing particle adhesion to the component and at least one removal mechanism for removing particles from the component, or a plurality of removal mechanisms for removing particles from the component.

Description

Technical Field

[0001] This invention relates to an apparatus and method for preparing and / or cleaning components for lithography equipment. More specifically, the component is a film. Prior Technology

[0002] A lithography apparatus is a machine configured to apply a desired pattern onto a substrate. Lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithography apparatus can project a pattern at a patterning device (e.g., a mask) onto a radiation-sensitive material (resist) layer disposed on a substrate.

[0003] To project a pattern onto a substrate, lithography equipment can use electromagnetic radiation. The wavelength of this radiation determines the minimum size of the feature that can be formed on the substrate. Compared to lithography equipment using radiation with a wavelength of, for example, 193 nm, lithography equipment using extreme ultraviolet (EUV) radiation with wavelengths in the range of 4 to 20 nm (e.g., 6.7 nm or 13.5 nm) can be used to form smaller features on the substrate.

[0004] The use of surface coatings in lithography is well-known and accepted. In use, the surface coating is placed in front of the patterning apparatus (reducing mask). This protects the reducing mask from contamination from the lithography equipment, but increases the potential for contamination from the surface coating itself. Because the surface coating is very close to the reducing mask (approximately 2 mm), any contamination on it poses a significant risk to the reducing mask's defect rate. Therefore, a clean surface of the surface coating is extremely important for the viability of any surface coating. []

[0005] In DUV or EUV lithography equipment, the typical surface film is a thin film positioned far from the patterning apparatus and outside the focal plane of the lithography equipment during use. Because the surface film is outside the focal plane of the lithography equipment, contaminant particles falling on the surface film are out of focus in the lithography equipment. Therefore, the image of the contaminant particles is not projected onto the substrate. If the surface film were not present, contaminant particles falling on the patterning apparatus would be projected onto the substrate and would introduce defects into the projected pattern. []

[0006] A surface coating may be required in EUV lithography equipment. EUV lithography differs from DUV lithography in that it is typically performed in a vacuum and the patterning apparatus is usually reflective rather than transmissive. The surface coating can be referred to as a thin film.

[0007] The surface film is produced under extremely clean conditions. However, it may still contain contaminating particles. Each of these particles poses a risk and can become a defect problem if released from the surface film and transported from the back side of the surface film to the front side of the patterning device (reducing mask) in the lithography equipment. These contaminating particles can cause printing defects, resulting in a loss of productivity.

[0008] There is a need for an apparatus and method for cleaning a lithography film (i.e., removing particles before the film enters the lithography apparatus), which overcomes or mitigates one or more problems associated with the prior art. Examples of the invention described herein may be used in EUV lithography apparatuses. Examples of the invention may also be used in DUV lithography apparatuses and / or other forms of lithography tools. Summary of the Invention

[0009] According to a first aspect of the present invention, an apparatus for cleaning a component supplied in a lithography device is provided. The apparatus includes at least one cleaning module or a plurality of cleaning modules, wherein the at least one cleaning module or the plurality of cleaning modules includes a plurality of cleaning mechanisms, and wherein the plurality of cleaning mechanisms includes: at least one preparation mechanism for reducing particle adhesion to the component; and at least one removal mechanism for removing particles from the component; or a plurality of removal mechanisms for removing particles from the component.

[0010] This has the advantage of removing a considerable amount, most, or all of the particles that may be released in the lithography device LA. The device can clean the component more effectively than other prior methods (i.e., remove more particles and / or do so in a faster time). The advantage of using one of multiple cleaning mechanisms is that more or different particles can be cleaned than could be cleaned using a single cleaning mechanism (or pressure source).

[0011] Cleaning a component may include both preparing to remove particles (e.g., reducing particle adhesion to the component) and removing particles (from the component).

[0012] The preparation mechanism can be used before the removal mechanism, that is, they can be used sequentially. The preparation mechanism and the removal mechanism can be used simultaneously, which can simultaneously reduce the adhesion of the particles to the component and remove the particles from the component.

[0013] The at least one cleaning module may contain a plurality of cleaning mechanisms. The plurality of cleaning modules may together contain a plurality of cleaning mechanisms, that is, one cleaning module may contain one cleaning mechanism and another cleaning module may contain another cleaning mechanism. One or more of these cleaning modules may each contain a plurality of cleaning mechanisms.

[0014] The device may include the plurality of cleaning modules, and the device may be configured such that the component can be sequentially passed through the plurality of cleaning modules for cleaning.

[0015] The cleaning module or such cleaning modules may include at least one separation module for removing particles from the component.

[0016] The device may include a robotic module for moving the component between modules.

[0017] The device may include a component (e.g., a membrane) library module, which contains a plurality of components.

[0018] The device may include a vacuum chamber module for separating the vacuum inside the device from the outside of the device.

[0019] This separation module can be used to reduce particle adhesion to the component during or before removal of particles from the component. This means that the efficiency of particle removal can be increased.

[0020] The cleaning modules may include: a plurality of separation modules, and / or at least one separation module and at least one preparation module, which are used to reduce particle adhesion to the component.

[0021] The cleaning module or such cleaning modules can be maintained in a vacuum or controlled gas environment.

[0022] The vacuum or controlled gas environment can be maintained between cleaning modules (e.g., from the preparation module to the separation module) to maintain reduced adhesion and prevent more particles from transferring to the component. The controlled gas environment may have a predetermined gas / pressure / temperature. The component can be transferred between cleaning modules under this vacuum or controlled gas environment.

[0023] The removal mechanism and / or the preparation mechanism may include a vacuum generating mechanism.

[0024] The vacuum generated by the vacuum generating mechanism can at least help reduce the adhesion of particles to the component or remove the particles from the component.

[0025] The preparation mechanism may include a heat generation mechanism configured to generate heat to dry the components and / or the particles in a vacuum environment.

[0026] The pressure of water vapor or other oxygen-containing gas in the vacuum environment may have at least one of the following: less than 1E-4 Pa, less than 1E-5 Pa, less than 1E-6 Pa, or less than 1E-7 Pa.

[0027] The heat-generating mechanism may include a radiant heater.

[0028] The heat generation mechanism can be configured such that the radiant heat toward one of the boundaries of the component is less than 1 W / cm2 and / or the boundary can be in contact with a heat sink such that the boundary temperature is kept below 400°C.

[0029] The radiant heater can be a laser or an IR lamp. The laser can have a wavelength in the range of 0.5 to 5 µm. The assembly can be heated all at once or in sections.

[0030] The radiant heat power density at the component can be less than 10 W / cm², preferably in the range of 1 to 5 W / cm² or 2 to 5 W / cm². The radiant heater can be configured to have a power density in the range of 1 to 5 W / cm² at the component applied within the range of 0.1 to 1000 seconds or 10 to 1000 seconds.

[0031] The preparation mechanism may include a plasma generation mechanism for generating a plasma in proximity to or around the component. This can facilitate water degassing, including water trapped in and around the particles. This can alter the composition and / or roughness of the particles.

[0032] The plasma generating mechanism can be configured to generate a plasma having at least one of the following: a reducing agent, hydrogen, an inert gas, a reducing agent and an oxidizing agent and / or hydrogen and water.

[0033] The ratio of reducing agent to oxidizing agent can be greater than 100, preferably greater than 1000. The concentration of the reducing agent can be much higher than the concentration of the oxidizing agent. This ensures the maintenance of the mechanical properties (strength and tensile strength) and optical properties (transmission and reflection) of the component (e.g., a membrane). The concentration of the reducing agent can be 1000 times higher than the concentration of the oxidizing agent.

[0034] The plasma generation mechanism can be configured to generate plasma having a power dissipation in the range of 1 mW / cm2 to 1 W / cm2 for the component.

[0035] The preparation mechanism may include an electron beam generating mechanism for generating an electron beam to be incident on the side of the component containing the particles to be removed.

[0036] The electron beam generating mechanism can be configured to generate the electron beam in an environment including at least one of the following: a reducing agent, hydrogen, a reducing agent and an oxidizing agent and / or hydrogen and water.

[0037] The ratio between the reducing agent and the oxidizing agent can be greater than 100, and preferably greater than 1000.

[0038] The pressure used for plasma generation can be in the range of 0.01 Pa to 100 Pa, preferably in the range of 0.1 Pa to 10 Pa.

[0039] The environment can have a pressure ranging from 0.01 Pa to 10 Pa.

[0040] The electron beam generating mechanism can be configured to have an energy range of 30 to 3000 eV, a current density at the component that can be in the range of 10 uA / cm2 to 10 mA / cm2, and / or a power dissipation at the component that can be less than 1 W / cm2.

[0041] The preparation mechanism may include a VUV or EUV photon generation mechanism for generating VUV or EUV photons to be incident on the component.

[0042] The VUV or EUV photon generating mechanism can be configured to generate the VUV or EUV photons in an environment including at least one of the following: a reducing agent, hydrogen, a reducing agent and an oxidizing agent and / or hydrogen and water.

[0043] The VUV or EUV photon generation mechanism can be configured to generate VUV or EUV photons with a power dissipation of less than 1 W / cm2 for the component.

[0044] The preparation mechanism may include a radical generation mechanism for generating hydrogen radicals in proximity to or around the component.

[0045] The free radical generating mechanism may include at least one of a plasma generating mechanism and / or a hot filament.

[0046] The removal mechanism may include a vibration generating mechanism for generating mechanical oscillations of the component.

[0047] The vibration generating mechanism may include at least one excitation electrode; and a mechanism for applying a time-varying voltage across the at least one excitation electrode and the component.

[0048] The removal mechanism may include a VUV photon generation mechanism for generating VUV photons to be incident on the component.

[0049] The VUV light can have a wavelength in the range of 20 to 200 nm (62 eV to 6.2 eV).

[0050] The VUV photons can charge these particles and the component.

[0051] The VUV photons can be incident on the surface of the component to be cleaned (e.g., the side facing a condenser mask of a film) or on the opposite surface of the component (e.g., the VUV light can pass through the film). The light incident on the opposite surface of the component to be cleaned can cause an increase in ionization between the particles and the component, thus maximizing the repulsion and cleaning effect.

[0052] The VUV photon generating mechanism can be configured to generate a VUV photon beam for substantially irradiating the entire surface or a portion of the surface of the component in a single operation, wherein the VUV photon beam can be scannable to irradiate the entire surface of the component.

[0053] The removal mechanism may include a plasma generating mechanism for generating a plasma in proximity to or around the component.

[0054] The plasma can charge these particles. The plasma / airflow can provide an impact to these particles.

[0055] The removal mechanism may include a heat-generating mechanism for inducing particle transport away from the component.

[0056] The heat-generating mechanism can be a laser.

[0057] The removal mechanism may include an electric field generating mechanism for transporting particles away from the component.

[0058] The electric field generating mechanism may include a collector electrode; and a mechanism for applying a voltage to the component and the collector electrode.

[0059] Two collector electrodes may exist.

[0060] The component can be removed, wherein the particles adhere to the collector electrode. This prevents the particles from returning to the component when the power to the collector electrode is disconnected.

[0061] The collector electrode may comprise a plate or a grid covering substantially all of the components or electrodes.

[0062] The device may include one or more shielding elements configured to prevent particles from returning to the component when the power supply to the collector electrodes is disconnected.

[0063] These shielding components can be retractable.

[0064] The removal mechanism may include an electron beam generating mechanism for generating an electron beam to be incident on the side of the component containing the particles to be removed.

[0065] The electron beam generating mechanism can be configured to generate an electron beam with an energy greater than 80 eV.

[0066] The electron beam generating mechanism can be configured to produce a pulsed electron beam.

[0067] The electron beam is combined with plasma. The electron beam (pulsed or continuous) can be incident on the component while the plasma source (plasma generating mechanism) provides plasma (which can be pulsed or continuous). Plasma and electrons from the electron beam can exist simultaneously or alternately at the component.

[0068] The electron beam generating mechanism may include a scanning electron microscope for imaging the particles and / or the components.

[0069] The device may include: at least one displacement sensor for measuring the displacement of the component relative to one of the components when stationary; and a controller operable to determine whether the measured displacement of the component is outside a predetermined range, and if the measured displacement of the component is outside the predetermined range, to control the mechanism for applying a time-varying electric field to change at least one characteristic of the time-varying electric field.

[0070] This displacement can be dynamic and corresponds to the low intrinsic mode of the membrane under tension within the component.

[0071] The device can be configured to allow one or more additional cleaning modules to be added to it.

[0072] The component may be at least one of a surface film, an EUV transparent film, a dynamic airlock film, or an EUV spectral purity filter.

[0073] Thin films (e.g., surface films) can be damaged during film cleaning. Specifically, a runaway failure can occur when mechanical oscillations of the film are induced using a time-varying electric field generator (e.g., at least one electrode), where the stiffness of the film cannot resist an electrostatic force generated by the electrode. In this case, the film deforms until it touches the electrode and is damaged.

[0074] Even when approximately equal pressures are applied to the two electrodes on opposite sides of the thin film, runaway failure remains a risk. According to the following equation, the thin film is subjected to a force with a stiffness coefficient (k) [N / mm] to resist instantaneous deformation (h) [mm]. [N]: .

[0075] The stiffness coefficient (k) can be in the range of 110 to 100 N / mm, typically 10 N / mm. If the deformation (h) becomes equivalent to a gap between the film and one of the electrodes, the electrostatic force generated by the two electrodes becomes unstable. If the electrostatic force generated by the two electrodes becomes unbalanced (e.g., unstable), a runaway failure will occur.

[0076] The smaller the gap between the film and the electrodes, the greater the risk of the electrostatic forces generated by the two electrodes becoming unbalanced. Furthermore, the larger the electrodes, the greater the risk of the electrostatic forces generated by the two electrodes becoming unbalanced. This greater sensitivity to the unbalanced electrostatic forces generated by the two electrodes is proportional to the pressure scaling and the square of the electric field, and therefore inversely proportional to the square of the gap between the film and the electrodes. This relationship is described in the following equation: ,

[0077] in: The force [N] applied to the thin film by one of the electrodes; The pressure on the thin film when it is equidistant from the first electrode and the second electrode (and the thin film is flat) [N / mm²]; This is the cross-section of one of these electrodes [mm²]. The position of the thin film when it is at rest [mm]; and h is the deviation of the position of the thin film from that position of the thin film when it is at rest [mm] (at the protrusion of the electrodes).

[0078] like If the film stiffness is insufficient to resist the attraction of the approaching electrodes, the film deforms until it touches one of the electrodes, thereby causing the film to fail.

[0079] Therefore, the present invention aims to provide a method and apparatus for removing particles from a thin film, which at least reduces the risk of runaway failure of the thin film.

[0080] According to a second aspect of the present invention, a thin-film cleaning apparatus for removing particles from a thin film is provided, the apparatus comprising: a thin-film support for supporting the thin film; a time-varying electric field generator for inducing mechanical oscillations of the thin film when supported by the thin-film support to remove particles from the thin film; at least one displacement sensor for measuring a displacement of the thin film relative to the thin film when supported by the thin-film support; and a controller operable to determine whether the measured displacement of the thin film is outside a predetermined range, and if the measured displacement of the thin film is outside the predetermined range, controlling the time-varying electric field generator to change at least one characteristic of the time-varying electric field.

[0081] Advantageously, the thin-film cleaning device for removing particles from a thin film reduces the risk of runaway failure of the thin film. Advantageously, the thin-film cleaning device for removing particles from a thin film allows the field strength of the time-varying electric field generated by at least one electrode to be increased (e.g., to improve particle removal) without the risk of runaway failure of the thin film. Advantageously, the thin-film cleaning device for removing particles from a thin film allows the at least one electrode to be positioned closer to the thin film (e.g., to improve particle removal) without the risk of runaway failure of the thin film.

[0082] The film may include a surface film.

[0083] The at least one displacement sensor can measure the displacement of the thin film substantially as frequently as at a frequency of at least one of the following low mechanical oscillation eigenmodes of the thin film: mode 1 (e.g., lowest mode, monopole), mode 2 (e.g., dipole, long side), mode 3 (e.g., dipole, short side), mode 4 (e.g., quadrupole) and other low-frequency eigenmodes.

[0084] Advantageously, measuring the displacement of the thin film substantially as frequently as at least one of the low-frequency eigenmodes makes it possible to use fewer displacement sensors (e.g., proximity sensors).

[0085] The at least one displacement sensor can measure the displacement of the thin film at a frequency higher than at least one of the following: 100 Hz, 1000 Hz, 10,000 Hz.

[0086] The at least one displacement sensor can measure the displacement of the thin film at a frequency lower than at least one of the following: 1000 Hz, 10,000 Hz, 100,000 Hz.

[0087] The at least one displacement sensor can measure the displacement of the thin film at a frequency higher than a frequency of at least one of the following low mechanical oscillation eigenmodes of the thin film: mode 1 (e.g., lowest mode, monopole), mode 2 (e.g., dipole, long side), mode 3 (e.g., dipole, short side), mode 4 (e.g., quadrupole).

[0088] Advantageously, measuring the displacement of the thin film more frequently than the low-frequency eigenmode makes it possible to better determine at least one of the amplitude, frequency, and phase of the mechanical oscillation of the thin film.

[0089] The predetermined displacement range may include the displacement of at least a portion of the film relative to the film when it is at rest, having a value smaller than at least one of the following: 10 µm, 100 µm, 1000 µm.

[0090] The at least one displacement sensor can be configured to measure the displacement of at least a local portion of the thin film relative to one of the local portions of the thin film when it is at rest.

[0091] A first displacement sensor can be configured to measure the displacement of a portion of the thin film relative to the portion of the thin film when at rest, relative to the displacement of ...

[0092] In use, the electrodes can be positioned equidistantly from the thin film. This equidistant positioning of the electrodes and the thin film allows for the balancing of one excitation of the thin film. For example, during operation, the electrodes apply forces to the thin film in opposing directions, and the time-averaged force on the thin film from the combined electrodes is less than 10% (e.g., preferably less than 1%) of the time-averaged force from any one of the electrodes.

[0093] The controller is operable to determine whether the measured displacement of one of the films is outside a predetermined range based on the maximum measured displacement of the film.

[0094] The controller may be operable to control the time-varying electric field generator to reduce a maximum displacement of the thin film by changing at least one of the following characteristics of the time-varying electric field: an amplitude; a frequency; a phase.

[0095] The controller may be operable to control the time-varying electric field generator to reduce one of the maximum displacements of the thin film by at least one of the following: reducing the amplitude of the time-varying electric field; changing the frequency of the time-varying electric field to reduce or remove the overlap between the frequency of the time-varying electric field and one of the mechanical oscillation frequencies of the thin film; changing the phase of the time-varying electric field to be out of phase with one of the mechanical oscillation phases of the thin film; at least for the low mode.

[0096] Advantageously, changing the phase of the time-varying electric field to be out of phase with the phase of one of the mechanical oscillations of the thin film can suppress the mechanical oscillations of the thin film more quickly than other methods.

[0097] The controller is operable to record the measured displacement and the measurement time of each displacement as time-varying displacement data.

[0098] The controller is operable to transform the time-varying displacement data to a frequency domain and extract at least one mechanical oscillation frequency of the thin film. Transforming the time-varying displacement data to the frequency domain includes using a Fast Fourier Transform.

[0099] The controller may be operable to control the time-varying electric field generator to change at least one of the characteristics of the time-varying electric field to reduce the maximum displacement of the thin film by controlling the at least one characteristic of the time-varying electric field for a holding time, during which the maximum displacement of the thin film returns to the predetermined displacement range, and then the at least one characteristic of the time-varying electric field is restored to its value before the holding time.

[0100] The controller may be operable to control the time-varying electric field generator to change at least one of the characteristics of the time-varying electric field to reduce the maximum displacement of the thin film by controlling the at least one characteristic of the time-varying electric field, so as to reduce the maximum displacement of the thin film until the device for removing particles from the thin film has completed the removal of particles from the thin film.

[0101] The time-varying electric field generator may include: at least one excitation electrode positioned close to one surface of the thin film when supported by the thin film support; and a mechanism for applying a time-varying voltage across the at least one excitation electrode to generate the time-varying electric field to induce mechanical oscillations of the thin film when supported by the thin film support.

[0102] The at least one time-varying electric field generator may include: a first excitation electrode and a second excitation electrode, each electrode being positioned close to different of two opposing surfaces of the thin film when supported by the thin film support; and a mechanism for applying a time-varying voltage across the first excitation electrode and the second excitation electrode to generate the time-varying electric field to induce mechanical oscillations of the thin film when supported by the thin film support.

[0103] The time-varying electric field generator can be configured such that there is a non-zero phase difference between the time-varying voltage applied to the first electrode and the time-varying voltage applied to the second electrode.

[0104] According to a third aspect of the present invention, a method for cleaning a component for use in a lithography device is provided, the method comprising: using at least one removal mechanism for removing particles from the component; and at least one preparation mechanism for reducing the adhesion of the particles to the component, or a plurality of removal mechanisms for removing particles from the component.

[0105] The device may include the plurality of cleaning modules. The method may further include sequentially passing the component through the cleaning modules for cleaning.

[0106] The method may further include passing the component through a plurality of separation modules for removing particles from the component, and / or passing the component through at least one preparation module for reducing particle adhesion to the component and subsequently passing the component through at least one separation module. Passing the component through the preparation module first means that when removing particles from the component is performed in the separation module, more particles can be removed than would be possible (i.e., the efficiency of the separation module for particle removal is significantly increased after processing the component in the preparation module).

[0107] The removal mechanism may include a vibration generating mechanism for generating mechanical oscillations of the component using a time-varying electric field. The method may further include: measuring a displacement of the component relative to the component when it is at rest; determining whether the measured displacement of the component is outside a predetermined range; and if the measured displacement of the component is outside the predetermined range, controlling at least one characteristic of the time-varying electric field.

[0108] According to a fourth aspect of the present invention, a method for removing particles from a thin film is provided for use in a lithography apparatus. The method includes: inducing mechanical oscillations of the thin film using a time-varying electric field to remove particles from the thin film; measuring a displacement of the thin film relative to the thin film when it is at rest; determining whether the measured displacement of the thin film is outside a predetermined range; and if the measured displacement of the thin film is outside the predetermined range, controlling at least one characteristic of the time-varying electric field.

[0109] Advantageously, the method of removing particles from the thin film reduces the risk of runaway failure of the thin film. Advantageously, the method of removing particles from the thin film allows the field strength of the time-varying electric field generated by at least one electrode to be increased (e.g., to improve particle removal) without the risk of runaway failure of the thin film. Advantageously, the method of removing particles from the thin film allows the at least one electrode to be positioned closer to the thin film (e.g., to improve particle removal) without the risk of runaway failure of the thin film.

[0110] The film may include a surface film.

[0111] The method may include measuring the displacement of the thin film substantially as frequently as at least one of the following low mechanical oscillation eigenmodes of the thin film: mode 1 (e.g., lowest mode, monopole), mode 2 (e.g., dipole, long side), mode 3 (e.g., dipole, short side), and mode 4 (e.g., quadrupole).

[0112] Advantageously, measuring the displacement of the thin film substantially as frequently as at least one of the low-frequency eigenmodes makes it possible to use fewer displacement sensors (e.g., proximity sensors).

[0113] The method may include measuring the displacement of the thin film at a frequency higher than at least one of the following: 1 Hz, 10 Hz, 100 Hz, 1000 Hz, 10,000 Hz.

[0114] The method may include measuring the displacement of the thin film at a frequency lower than at least one of the following: 10 Hz, 100 Hz, 1000 Hz, 10,000 Hz.

[0115] The method may include measuring the displacement of the thin film at a frequency higher than at least one of the following low mechanical oscillation eigenmodes of the thin film: mode 1 (e.g., lowest mode, monopole), mode 2 (e.g., dipole, long side), mode 3 (e.g., dipole, short side), mode 4 (e.g., quadrupole).

[0116] Advantageously, measuring the displacement of the thin film more frequently than the low-frequency eigenmode makes it possible to better determine at least one of the amplitude, frequency, and phase of the mechanical oscillation of the thin film.

[0117] Measuring the displacement of the film relative to the film when it is at rest may include measuring the displacement of at least a portion of the film relative to one of that portion of the film when it is at rest.

[0118] The predetermined displacement range may include the displacement of at least a portion of the film relative to the film when it is at rest, having a value smaller than at least one of the following: 10 µm, 100 µm, 1000 µm.

[0119] Whether the measured displacement of the film is outside the predetermined range can be determined based on the maximum measured displacement of one of the films.

[0120] The characteristic of the time-varying electric field may include at least one of the following: an amplitude; a frequency; a phase.

[0121] Controlling at least one characteristic of the time-varying electric field to reduce one of the maximum displacements of the thin film may include at least one of the following: reducing the amplitude of the time-varying electric field; changing the frequency of the time-varying electric field to reduce or remove the overlap between the frequency of the time-varying electric field and the mechanical oscillation frequency of the thin film; changing the phase of the time-varying electric field to be out of phase with the mechanical oscillation phase of the thin film.

[0122] Advantageously, changing the phase of the time-varying electric field to be out of phase with the phase of one of the mechanical oscillations of the thin film can suppress the mechanical oscillations of the thin film more quickly than other methods.

[0123] The method may include recording the measured displacement and the measurement time of each displacement as time-varying displacement data.

[0124] The method may include transforming the time-varying displacement data to a frequency domain and extracting at least one mechanical oscillation frequency of the thin film. Transforming the time-varying displacement data to the frequency domain includes using a Fast Fourier Transform.

[0125] Controlling at least one characteristic of the time-varying electric field to reduce the maximum displacement of the thin film may include controlling at least one characteristic of the time-varying electric field for a holding time, during which the maximum displacement of the thin film returns to the predetermined displacement range, and then restoring at least one characteristic of the time-varying electric field to its value before the holding time.

[0126] Controlling at least one characteristic of the time-varying electric field to reduce the maximum displacement of the thin film may include controlling at least one characteristic of the time-varying electric field until the method of removing particles from the thin film has been completed.

[0127] Inducing mechanical oscillations in the thin film may involve applying a time-varying voltage across at least one excitation electrode positioned close to one of the surfaces of the thin film.

[0128] The time-varying voltage can apply a pressure pulse with a pressure of 10 to 1000 Pa (e.g., 100 Pa). The time-varying voltage can apply the pressure pulse for a duration of 10 to 1000 ns (e.g., 100 ns). The time-varying voltage can have an average repetition rate of 10 to 1000 kHz, for example, 100 kHz. Advantageously, the time-varying voltage can have a variable peak pulse repetition rate of 1 to 10 MHz to resonate and overlap the first / second / third harmonic frequencies with one of the associated particles for optimal excitation.

[0129] The pressure pulses applied by the time-varying voltage can induce resonant oscillations of particles (i.e., mass blocks) on the thin film (e.g., acting as a spring), with a characteristic frequency of approximately 1 to 10 MHz. When the amplitude of this mechanical oscillation is... to At that time, this characteristic frequency range corresponds to to One of the maximum instantaneous accelerations, and to One of the maximum instantaneous velocities.

[0130] The pressure pulse and the time-varying voltage can have the same duration. The time-varying voltage (e.g., a voltage pulse) is applied to a pressure pulse with... to ,For example to One of the electrodes is a cross-section of the film. These electrodes can be positioned away from the film. to Advantageously, in order to provide a required electrostatic pressure The electrode can be positioned within 0.5 mm to 2.5 mm of the thin film.

[0131] Inducing mechanical oscillations in the thin film may involve applying a time-varying voltage to each of a first excitation electrode and a second excitation electrode positioned close to the opposing surface of the thin film.

[0132] The mechanical oscillation induced by the thin film may include a non-zero phase difference between the time-varying voltage applied to the first excitation electrode and the time-varying voltage applied to the second excitation electrode.

[0133] According to a fifth aspect of the present invention, a non-transitory computer-readable storage medium is provided, which includes instructions that, when executed by a processing circuit, cause the processing circuit to perform the thin-film cleaning method.

[0134] In any other variant or embodiment, the features mentioned above in any variant of the invention or below with respect to any particular embodiment of the invention may be used alone or in combination with any other defined features, or to form another variant or embodiment of the invention. Simple Explanation of the Diagram

[0135] Embodiments of the invention will now be described by way of example only, with reference to the accompanying illustrative drawings, in which: Figure 1 depicts a lithography system comprising a lithography device and a radiation source, the lithography device including a surface film assembly; Figure 2 depicts an apparatus for cleaning a contaminated film according to an embodiment of the present invention; Figure 3 depicts an apparatus for cleaning a film according to an embodiment of the present invention; - Figures 4a) to 4d) depict the surface film according to an embodiment of the present invention and the VUV photon generation mechanism during the step of cleaning the surface film; - Figure 5a) depicts the surface film and VUV photon generation mechanism according to an embodiment of the present invention; - Figure 5b) depicts the surface film and VUV photon generation mechanism according to an embodiment of the present invention; - Figure 6 depicts the film, plasma generation mechanism, heat generation mechanism, and electric field generation mechanism according to an embodiment of the present invention; Figure 7 depicts the coating and electron beam generating mechanism according to an embodiment of the present invention; - Figure 8 depicts a film and particles to be removed from the film according to an embodiment of the present invention; Figure 9 illustrates an embodiment of the film cleaning apparatus and film according to the present invention; Figure 10 is a schematic diagram of a portion of the film shown in Figure 9, illustrating a mechanism for removing particles from the film using the film cleaning device (with a cleaning component) shown in Figure 9; - Figure 11a shows an example voltage applied across the thin film and electrodes as a function of time using the thin film cleaning device (with a cleaning component) shown in Figure 9; - Figure 11b is a first schematic illustration of the excitation spectrum of the applied voltage corresponding to the form shown in Figure 11a. It shows the excitation force applied to the thin film as the frequency of the excitation force varies, and schematically indicates the frequency composition of the pulsed voltage and how this frequency composition can be changed by modulating the pulse repetition frequency. - Figure 11c is a second schematic illustration of the excitation spectrum, which schematically shows the frequency composition of the pulsed voltage shown in Figure 11a and how this frequency composition can be changed by modulating the pulse repetition frequency and the pulse shape; - Figure 12 shows an embodiment of the membrane cleaning device of Figure 9 in use; Figure 13 shows a flowchart illustrating a method for removing particles from a thin film according to another embodiment of the present invention; Figure 14 shows a flowchart illustrating a method for removing particles from a thin film according to another embodiment of the present invention; Figure 15 shows a flowchart illustrating a method for removing particles from a thin film according to another embodiment of the present invention; Figure 16 shows a flowchart illustrating a method for removing particles from a thin film according to another embodiment of the present invention; Figure 17 illustrates a film cleaning apparatus and an alternative embodiment of the film according to an embodiment of the present invention. Implementation

[0136] Figure 1 illustrates a lithography system including a radiation source SO and a lithography device LA. The radiation source SO is configured to generate an EUV radiation beam B and supply the EUV radiation beam B to the lithography device LA. The lithography device LA includes an illumination system IL, a support structure MT configured to support a patterning device MA (e.g., a mask), a projection system PS, and a substrate stage WT configured to support a substrate W.

[0137] The irradiation system IL is configured to adjust the EUV radiation beam B before it is incident on the patterning device MA. Additionally, the irradiation system IL may include a faceted field mirror device 10 and a faceted pupil mirror device 11. Together, the faceted field mirror device 10 and the faceted pupil mirror device 11 provide the desired cross-sectional shape and intensity distribution to the EUV radiation beam B. In addition to or replacing the faceted field mirror device 10 and the faceted pupil mirror device 11, the irradiation system IL may include other mirrors or devices. The radiation beam B is transmitted from the irradiation system IL and incident on the patterning device MA, which is held in place by the support structure MT. The patterning device MA is protected by a coating 19, which is held in place by a coating frame 17. The coating 19 and the coating frame 17 together form a coating assembly 15.

[0138] After such adjustment, the EUV radiation beam B interacts with the patterning device MA. This interaction produces a patterned EUV radiation beam B'. The projection system PS is configured to project the patterned EUV radiation beam B' onto the substrate W. For this purpose, the projection system PS may include a plurality of mirrors 13, 14 configured to project the patterned EUV radiation beam B' onto the substrate W held by the substrate stage WT. The projection system PS may apply a reduction factor to the patterned EUV radiation beam B', thus forming an image with features smaller than the corresponding features on the patterning device MA. For example, a reduction factor of 4 or 8 may be applied. Although the projection system PS is illustrated in FIG. 1 as having only two mirrors 13, 14, the projection system PS may include a different number of mirrors (e.g., six or eight mirrors).

[0139] The substrate W may include a previously formed pattern. In this case, the lithography apparatus LA aligns the image formed by the patterned EUV radiation beam B' with the pattern previously formed on the substrate W.

[0140] A relative vacuum, i.e., a small amount of gas (e.g., hydrogen) at a pressure sufficiently below atmospheric pressure, can be provided in the radiation source SO, the irradiation system IL, and / or the projection system PS.

[0141] The radiation source SO shown in Figure 1 is of the type that may be called a laser-generated plasma (LPP) source, for example. A laser system 1, which may include, for example, a CO2 laser, is configured to deposit energy via a laser beam 2 onto a fuel (such as tin (Sn)) supplied by, for example, a fuel emitter 3. Although tin is mentioned in the following description, any suitable material may be used. The fuel may be, for example, in liquid form and may be, for example, a metal or alloy. The fuel emitter 3 may include a nozzle configured to guide tin, for example, in droplet form, along a trajectory toward the plasma formation region 4. The laser beam 2 is incident on the tin at the plasma formation region 4. The deposition of laser energy into the tin generates tin plasma 7 at the plasma formation region 4. Radiation, including EUV radiation, is emitted from the plasma 7 during the de-excitation and recombination of electrons and plasma ions.

[0142] EUV radiation from the plasma is collected and focused by collector 5. Collector 5 includes, for example, a near-normal incidence radiation collector 5 (sometimes referred to as a more general normal incidence radiation collector). Collector 5 may have a multi-layered mirror structure configured to reflect EUV radiation (e.g., EUV radiation with a desired wavelength such as 13.5 nm). Collector 5 may have an ellipsoidal configuration with two foci. As described below, the first of these foci may be located in the plasma formation region 4, and the second of these foci may be located in the intermediate focal point 6.

[0143] Laser system 1 can be spatially separated from radiation source SO. In this case, laser beam 2 can be delivered from laser system 1 to radiation source SO via a beam delivery system (not shown), which includes, for example, suitable guide mirrors and / or beam expanders, and / or other optical components. Laser system 1, radiation source SO, and beam delivery system can be considered together as a radiation system.

[0144] The radiation reflected by collector 5 forms an EUV radiation beam B. EUV radiation beam B is focused at intermediate focal point 6 to form an image at intermediate focal point 6 of the plasma present in plasma formation region 4. The image at intermediate focal point 6 serves as a virtual radiation source for irradiating system IL. Radiation source SO is configured such that intermediate focal point 6 is located at or near opening 8 in the enclosure structure 9 of radiation source SO.

[0145] Although Figure 1 depicts the radiation source SO as a laser-generated plasma (LPP) source, any suitable source, such as a discharge-generated plasma (DPP) source or a free electron laser (FEL), can be used to generate EUV radiation.

[0146] As briefly described above, the liner assembly 15 includes a liner 19 provided adjacent to the patterning device MA. The liner 19 is positioned in the path of the radiation beam B such that the radiation beam B passes through the liner 19 in both cases: when its self-illumination system IL approaches the patterning device MA and when it is reflected from the patterning device MA toward the projection system PS. This location of the liner 19 within the lithography apparatus LA is the EUV radiation exposure location. The liner 19 comprises a thin film or membrane that is substantially transparent to EUV radiation (although it will absorb a small amount of EUV radiation). In this document, an EUV-transparent liner or a substantially transparent membrane for EUV radiation means that the liner 19 transmits at least 65%, preferably at least 80%, and more preferably at least 90% of the EUV radiation. The thin film 19 serves to protect the patterning device MA from particle contamination. The liner 19 may be referred to herein as an EUV-transparent liner. The liner 19 may be made of any material that is sufficiently transparent to EUV radiation, such as molybdenum siliconide (MoSi). MoSi is stronger than silicon at high temperatures because it cools more rapidly than silicon. In other instances, the surface film can be made of other materials such as silicon, silicon nitride, graphene or graphene derivatives, carbon nanotubes, or multilayer films formed by alternating EUV transparent materials.

[0147] Despite efforts to maintain a clean environment within the lithography apparatus LA, particles can still be present. In the absence of the surface film 19, particles can deposit onto the patterning apparatus MA. Particles on the patterning apparatus MA can adversely affect the pattern imparted to the radiation beam B and thus affect the pattern transferred to the substrate W. The surface film 19 provides a barrier between the patterning apparatus MA and the environment within the lithography apparatus to prevent particle deposition on the patterning apparatus MA.

[0148] In use, the surface film 19 is positioned at a sufficient distance from the patterning device MA such that any particles incident on the surface of the surface film 19 are not within the focal plane of the radiation beam B. This distance between the surface film 19 and the patterning device MA reduces the extent to which any particles on the surface of the surface film 19 impart a pattern to the radiation beam B. It should be understood that if a particle is present in the radiation beam B but is not located within the focal plane of the radiation beam B (i.e., not on the surface of the patterning device MA), then any image of that particle will not be focused on the surface of the substrate W. In some examples, the distance between the surface film 19 and the patterning device MA may be, for example, between 2 mm and 3 mm (e.g., about 2.5 mm). In some examples, the distance between the surface film 19 and the patterning device may be adjustable.

[0149] Figure 2 is a schematic cross-sectional view of the film assembly 15 and shows the device 20 for cleaning the film 19. The device 20 is schematically shown as a dashed line, and its features will be described. A contaminant particle 26A is schematically shown. The contaminant particle 26A is shown on the front side of the film 19 (i.e., the side facing away from the patterning device MA during use). During use, the film 19 holds the contaminant particle 26A sufficiently away from the patterned surface of the patterning device MA, so that it is not imaged onto the substrate by the lithography device LA.

[0150] Additionally, contaminant particles 26B are schematically shown on the back side of the film 19 (i.e., the side facing the patterning device MA during use). Contaminant particles 26B (and any other contaminant particles on the back side of the film) are a primary concern because they can cause defects and consequently, productivity losses. Specifically, if contaminant particles 26B are released from the film 19 and transported from the back side of the film 19 to the front side of the patterning device (reducing mask) MA in the lithography apparatus LA. However, the device 20 can also be used to clean contaminant particles 26A from the front side of the film 19.

[0151] Although the surface membrane will be described as being cleaned by the equipment, it should be understood that in other embodiments, other components may be cleaned by the equipment. For example, other components may include EUV transparent membranes, dynamic airlock membranes, or EUV spectral purity filters.

[0152] Device 20 is shown in more detail (schematically) in Figure 3. Device 20 comprises a plurality of modules. These modules include a cleaning module and other modules for different purposes. The device may be referred to as a membrane cleaning cluster (i.e., a cluster of modules). The cleaning module comprises a preparation module 30 and a separation module 32. The separation module 32 is used to remove particles 26A, 26B from the membrane 19. Removing particles 26A, 26B from the membrane 19 can be considered a removal mechanism. The preparation module 30 is used to reduce the adhesion of particles 26A, 26B to the membrane 19 (e.g., before the membrane 19 moves to the separation module 32). The preparation module 30 can be considered as pre-treating the membrane 19 to reduce the adhesion of particles thereon before the subsequent removal of particles 26A, 26B (i.e., in the separation module 32). Reducing the adhesion of particles 26A, 26B to the membrane 19 can be considered a preparation mechanism. The removal mechanism and the preparation mechanism can be regarded as cleaning mechanisms. The cleaning of the membrane 19 can be regarded as including both preparing to remove particles 26A and 26B (that is, reducing the adhesion of particles to the membrane 19) and removing particles 26A and 26B (from the membrane 19).

[0153] A spare module 34 is also present, which can be used for one or more additional cleaning modules to be added to device 20. It can also be used for other modules as needed. In other embodiments, one or more spare modules may be present. Device 20 is configured to allow one or more additional cleaning modules (or other modules) to be added to device 20. Modules are schematically shown as hexagons, but this is only to illustrate an example of modules that can be connected to each other. It should be understood that modules may be of other shapes and sizes as needed. Additionally, six modules are shown, but it should be understood that more or fewer modules may be present in device 20 as needed. It should be understood that the membrane can be transferred between modules in a controlled environment, for example, under vacuum or a user-defined gas / pressure / temperature atmosphere.

[0154] Other modules in device 20 may include: a robot module 36 for moving the diaphragm 19 (e.g., between cleaning modules); a diaphragm library module 38 (more generally, a component library) containing a plurality of diaphragms selectable for cleaning and use in the lithography device LA; and a vacuum chamber module 40 for loading the magnifying mask MA and the diaphragm 19 into the lithography device LA. Arrows adjacent to the vacuum chamber 40 indicate directions of movement into and out of device 20. It may be directed to the outside world (e.g., a cleaning chamber), i.e., not directly to the lithography device LA. The vacuum chamber module 40 is used to separate the vacuum inside the device (i.e., within modules 30, 32, 34, 36, 38) from the outside world. The robot module 36 may be referred to as an IVR (Indoor Robotic Vacuum Robot). The magnifying mask library module may be referred to as a vacuum library (IVL). The vacuum chamber module 40 may be referred to as a (vacuum) load lock (LDLK). The modules of device 20 can be maintained under vacuum or under a clean gas downflow, preventing (additional) particles 26A and 26B from transferring onto the membrane 19. It should be understood that other modules (i.e., module robot module 36, membrane library module 38, vacuum chamber module 40) are subordinate / optional and can help manipulate the membrane (or condenser mask), and they can also be separated from device 20.

[0155] In use, the membrane 19 is inserted into the device 20 and initially located in the preparation module 30, where the adhesion of particles 26A and 26B can be reduced. This can be achieved by different methods as will be explained below. After the adhesion of particles 26A and 26B to the membrane 19 is reduced, the membrane 19 can be moved from the preparation module 30 to the separation module 32 by the robot module 36.

[0156] The vacuum can be maintained from the preparation module 30 to the separation module 32, thereby reducing adhesion and preventing more particles 26A, 26B from transferring to the surface membrane 19. In an embodiment, the entire device is maintained under vacuum (e.g., using a vacuum chamber module 40). In an embodiment, the preparation module 30 and / or the separation module 32 may include a vacuum generating mechanism for generating a specific vacuum level. The vacuum generated by the vacuum generating mechanism can at least help reduce particle adhesion to the components or remove particles from the components.

[0157] In this embodiment, there is a single preparation module 30 and a single separation module 32. However, in other embodiments, there may be a plurality of separation modules and / or a plurality of preparation modules. In some embodiments, there may be no preparation module, that is, only one or more separation modules may exist. Furthermore, in some embodiments, the preparation module and the separation module may be combined into a single module. This can still be considered a separation module when removing particles from the surface film, but the particles may also undergo an adhesion reduction method during or before particle removal. That is, the separation module 32 can be used to reduce particle adhesion to the component during or before particle removal from the component. In this case, the separation module 32 includes a preparation mechanism and a removal mechanism.

[0158] In embodiments, at least one of the cleaning modules (e.g., separation module 32) may include a plurality of cleaning mechanisms. In embodiments, the cleaning module (i.e., separation module 32) may include a preparation mechanism and a removal mechanism. In embodiments, the preparation mechanism and the removal mechanism may be the same mechanism, i.e., a single mechanism can perform two functions. In embodiments, the cleaning module (i.e., separation module 32) may include a plurality of removal mechanisms. If there is more than one cleaning module, all such cleaning modules together may include a plurality of cleaning mechanisms; that is, one cleaning module may include one cleaning mechanism and another cleaning module may include another cleaning mechanism. One or more of the cleaning modules may each include a plurality of cleaning mechanisms.

[0159] A method for reducing particle adhesion to the surface membrane 19 (i.e., the preparation mechanism) will now be described. The preparation module 30 may include a heat-generating mechanism configured to generate heat in a vacuum environment to dry the surface membrane 19 and / or particles 26A, 26B. The water vapor pressure in the preparation module 30 and the separation module 32 may be lower than 1E-6 mbar (1E-4 Pa), preferably lower than 1E-7 mbar (1E-5 Pa), more preferably lower than 1E-8 or 1E-9 mbar (1E-6 Pa or (1E-7 Pa), and even more preferably lower than 1E-10 mbar (1E-8 Pa).

[0160] The heat-generating mechanism can be a radiant heater, such as a laser or IR lamp. The radiant heater can be configured to have an average power density in the range of 1 to 5 W / cm² at the applied film 19 within a range of 0.1 to 1000 seconds or 10 to 1000 seconds. Preferably, the radiant heat toward the film boundary is limited to less than 1 W / cm² and / or the boundary is in contact with the heat sink so that the film boundary temperature is kept below 400°C, preferably below 200°C. This prevents the film from cracking due to the difference in the coefficient of thermal expansion (CTE) between the film and the film boundary.

[0161] Vacuum and heat cause the removal of capillary water layers (or even nanodroplets) present in the contact area between particles 26A, 26B and the membrane 19. The membrane 19 may have a hydrophilic surface (e.g., SiO₂); the particles 26A, 26B remaining on the membrane 19 during production may be hydrophilic or superhydrophilic, which imposes a temperature specification of 200 to 500°C, necessary for removing water collected on the particles and at the particle / membrane contact point. Baking the membrane is important to suppress the adhesive effect of capillary forces. The membrane 19 can be heated to 500°C, which is the design temperature for membranes used in EUV lithography equipment LA during operation. Therefore, radiation baking is acceptable for the membrane 19. The partial pressure can also be maintained at extremely low levels (e.g., << 1E-9 mbar) to ensure that a new water film does not immediately form after 'drying'.

[0162] As an alternative to heating with a radiant heater, plasma can be used. That is, the preparation module 30 may include a plasma generation mechanism for generating plasma adjacent to or surrounding the coating 19. In this case, the ions, radicals, and excited substances of the plasma can promote water degassing, including the retention and surrounding of water around particles 26A, 26B. The plasma preferably contains an inert gas and / or hydrogen (H₂) to prevent loss of the optical or mechanical properties of the coating 19 during processing (e.g., as anticipated by oxidation).

[0163] Therefore, the preparation module 30 may include mechanisms (e.g., heat generation mechanisms and / or plasma generation mechanisms) for removing water from between the particles 26A, 26B and the membrane 19. This removal of water reduces the adhesion of the particles 26A, 26B to the membrane 19. This means that when removing particles 26A, 26B from the membrane 19 (e.g., in the separation module 32), more particles 26A, 26B can be removed (i.e., after processing the membrane in the preparation module 30, the efficiency of the separation module 32 for particle removal is significantly increased).

[0164] Alternatively, the plasma generating mechanism may reduce the adhesion of particles 26A, 26B to the film 19 via another component. In some embodiments, the effect of the plasma generating mechanism on the composition or roughness of particles 26A, 26B and / or the film itself may be achieved by increasing the effective separation between particles 26A, 26B and the film 19 or by changing the Hamaker constant, resulting in a significant reduction in adhesion.

[0165] In lithography (LA) equipment, EUV photons, EUV plasma, and / or photoelectrons promote and / or reduce (which may be material-specific), break chemical bonds, and cause etching, for example, by forming volatile hydrides or oxides, on the surface. These processes can alter the chemical interactions between particles and the surface film, but can also locally alter the shape (roughness) of the particles, resulting in reduced contact area and thus reduced adhesion. Similar effects can be expected when plasma or electron beams are combined with reactive gases acting on the surface film or particles.

[0166] In addition, EUV photons cause the release of electrons from the surface film, which has an effect similar to that of photons themselves.

[0167] Reactive hydrogen substances present in the plasma surrounding the film can etch organic and other materials, induce other chemical reactions, and lead to the formation of crystalline hydrides. This morphological change can be attributed to reduced adhesion by decreasing the contact area through surface roughening. It is believed that applying similar stress to the film and particles before separation tooling treatment can improve cleaning efficiency.

[0168] As mentioned, one way to reduce the adhesion effect of the simulated particles 26A and 26B on the membrane 19 in device 20 is by using a plasma generation mechanism. The plasma generation mechanism can be configured to generate a plasma containing hydrogen or either hydrogen or water. In the presence of water, the water content can be at least 1000 times less than the hydrogen content to maintain the properties of the membrane 19 (i.e., without damaging the membrane 19). The power dissipation of the membrane 19 is preferably in the range of 1 mW / cm² to 1 W / cm².

[0169] Another way to reduce the adhesion effect in simulation device 20 is by using an electron beam generating mechanism. That is, in an embodiment, preparation module 30 includes an electron beam generating mechanism for generating an electron beam to be incident on the surface film 19. The electron beam generating mechanism can be configured to generate an electron beam in an environment containing hydrogen or hydrogen and water, and / or an inert gas, having a pressure in the range of 0.001 Pa to 100 Pa, preferably 0.1 Pa to 10 Pa. Preferably, the processing by electron beam is performed after surface film baking and / or plasma treatment, after the water layer surrounding the particles has been removed (and electron shielded).

[0170] The environment can have a pressure ranging from 1E-4 mBar (0.01 Pa) to 1E-1 mBar (10 Pa). The electron beam generating mechanism can be configured to have an energy ranging from 30 to 3000 eV and / or a current density at the membrane 19 ranging from 10 uA / cm² to 10 mA / cm², while power dissipation (beam energy multiplied by beam current density) remains below 1 W / cm². Thus, the membrane will not be damaged. The electron beam should radiate at least the back side of the membrane 19 (with particles 26B) and, if necessary, the front side (while using an additional source) or, sequentially, a single source with varying mutual orientation of the source and the membrane. The membrane should be grounded at least for the duration of the electron beam treatment to allow the current deposited on the membrane by the beam to drain.

[0171] Another way to reduce the adhesion effect in simulation device 20 is by using a VUV photon generation mechanism (i.e., exposure to VUV photons). Specifically, in an embodiment, preparation module 30 includes a VUV photon generation mechanism (i.e., a VUV photon source) for providing VUV photons to be incident on the surface membrane 19 (preferably at least on the back side containing the key particle 26B). The VUV photon generation mechanism can provide radiation to the surface membrane in a reactive environment (e.g., hydrogen or hydrogen and water vapor). The power dissipation of the surface membrane from VUV photon absorption is preferably less than 1 W / cm².

[0172] Alternatively, EUV photons can be used to simulate the reduced adhesion effect in device 20. That is, in an embodiment, preparation module 30 includes an EUV photon generation mechanism (i.e., an EUV photon source) for providing VUV photons to be incident on the surface 19 (preferably at least on the back side containing the key particle 26B). The VUV photon generation mechanism can provide radiation to the surface in a reactive environment (e.g., hydrogen or hydrogen and water vapor). The power dissipation of the surface 19 from VUV photon absorption is preferably less than 1 W / cm². However, using VUV photons may be cheaper than EUV photons.

[0173] Although hydrogen or hydrogen and water vapor are mentioned as plasma or environment for electron beams, VUV or EUV photons, it should be understood that in other embodiments, other reducing agents / oxidizing agents besides H₂ or H₂O may be used. However, the ratio between the reducing agent and the oxidizing agent should be controlled to ensure that the mechanical properties (strength, tension) and optical properties (transmission / reflection) of the film are maintained during the adhesion removal step. That is, the concentration of the reducing agent can be relatively much higher than the concentration of the oxidizing agent. This is to ensure that the mechanical properties (strength and tension) and optical properties (transmission and reflection) of the film 19 are maintained. As an example, the concentration of the reducing agent can be 1000 times or more than 1000 times higher than the concentration of the oxidizing agent.

[0174] In an embodiment, the preparation module 30 may include a radical generation mechanism for generating H* (atomic hydrogen) adjacent to or surrounding the surface membrane 19. The radical generation mechanism may include a plasma generation mechanism and / or a hot filament suspended in a hydrogen gas stream.

[0175] It should be understood that various methods for reducing the adhesion of particles 26A, 26B to the surface film 19 may be performed in a separation preparation module 30, which may be included in a plurality of cleaning modules of the device 20. For example, one preparation module may include a heat generation mechanism, and another separation preparation module may include an electron beam generation mechanism. It should also be understood that in some embodiments, more than one of various methods for reducing the adhesion of particles in the same preparation module may be present.

[0176] Methods for removing particles 26A, 26B (i.e., removal mechanisms) from the surface film 19 will now be described. Methods and apparatuses described in either of the published patent applications WO2021073799 and WO2020109152 (which are incorporated herein by reference in their entirety) may be used in or as an option of the separation module 30. The separation module 30 may include a VUV photon generation mechanism for generating VUV photons to be incident on the component.

[0177] Figure 4a) shows particles 26B on the back side of the coating 19 (i.e., the photomask side of the coating 19), wherein the coating 19 is supported by the coating frame 17. Figure 4b) shows the VUV photon generation mechanism 42 that generates VUV light (VUV photon beam 44) onto the coating 19. The VUV light irradiates the area where the particles 26B of the coating 19 are located. The VUV light may have a wavelength in the range of 20 to 200 nm (62 eV to 6.2 eV). Vacuum ultraviolet (VUV) light sources are more readily available than EUV sources from multiple suppliers, and they may be cheaper. Generally, it is not easy to obtain a sufficient dose of EUV light for coating cleaning.

[0178] As shown in Figure 4c), VUV photons charge particle 26B and membrane 19 using the photoelectric effect. Both membrane 19 and particle 26B are positively charged due to the ejected electrons (e-). Since membrane 19 and particle 26B have the same charge, there is an electrostatic repulsion between particle 26B and membrane 19.

[0179] As shown in Figure 4d), the electrostatic repulsion between particle 26B and the surface film 19 (e.g., a dielectric surface) ejects particle 26B from the surface film 19. This assumes that the electrostatic repulsion between particle 26B and the surface film 19 is greater than the adhesive force that holds particle 26B to the surface film 19. The adhesion of particle 26B to the surface film 19 may have been reduced in advance during the preparation module 30.

[0180] In this embodiment, the VUV photon beam 44 (i.e., VUV photons) is incident on the opposite surface of the coating 19 to be cleaned (i.e., in this embodiment, it is the front side of the coating 19 on which the light is incident). That is, the VUV light irradiates through the coating 19. The VUV light incident on the surface of the coating 19 opposite to the surface to be cleaned can lead to increased ionization between particles 26B and the coating 19, thus maximizing the repulsion and cleaning effect. In other embodiments, the VUV light can be incident on the surface of the coating 19 to be cleaned (e.g., the back side of the coating 19). The side on which the VUV light is incident can depend on the selected light source wavelength and the material of the coating 19. The back side of the magnifying glass is typically the side of the coating 19 to be cleaned (or at least more importantly, the side to be cleaned), but it can also clean the front side of the magnifying glass.

[0181] This method can then be applied to the entire surface of the film 19, regardless of the location of particle 26B. Therefore, this technique does not require precise measurement to guide and can remove particles 26B of extremely small size, because it is not limited by the detection limits of measurement tools.

[0182] Previous systems used for cleaning the film could have low yields because they only cleaned the light spot (i.e., they cleaned the film very locally). They required information about the location of the particles to be removed and then removed these individual particles. This made such techniques quite slow and dependent on accurate measurements to determine the location of all particles at risk of potential photomask contamination.

[0183] Figure 5a) illustrates an embodiment of a VUV photon generation mechanism 42 that generates a VUV photon beam 44 to simultaneously irradiate (substantially) the entire surface area of ​​the coating 19. Therefore, all particles 26B on the coating 19 will be charged simultaneously by VUV photons and thus can be removed from the coating 19 in a relatively fast timescale (i.e., much faster than first using a metric to locate the particles and then removing the discovered particles).

[0184] Figure 5b) illustrates an embodiment of a VUV photon generation mechanism 42 that generates a VUV photon beam 44 to irradiate the surface of the coating 19 and then scans the VUV photon beam 44 across the surface of the coating 19 so that the entire surface of the coating 19 is irradiated (albeit not simultaneously). The VUV photon generation mechanism 42 can be configured to scan the VUV photon beam 44 (i.e., the VUV photon beam 44 is scannable). Therefore, all particles 26B on the coating 19 will be charged by VUV photons in a relatively short time scale (the time taken to scan the beam across the entire surface) and thus can be removed from the coating 19 in a relatively fast time scale (i.e., this is still much faster than first using a metric to locate the particles and then removing the found particles).

[0185] In some embodiments, the separation module 32 may include a plasma generation mechanism.

[0186] Figure 6 illustrates a plasma generation mechanism (plasma source) 50 for generating plasma 52 adjacent to or surrounding the membrane 19. In this embodiment, two plasma sources 50 are present, but in other embodiments, only one plasma source may be present. The plasma 52 charges particles 26A, 26B (not shown). An airflow (and plasma) can provide an "impact" to particles 26A, 26B. This impact itself can eject some particles 26A, 26B.

[0187] Additionally, the separation module 30 includes an electric field generating mechanism for transporting particles 26A and 26B away from the surface membrane 19. The electric field generating mechanism includes two collector electrodes 54, one located on each side of the surface membrane 19. An AC / DC voltage supply 56 is provided to supply voltage to the two collector electrodes 54. This establishes an electric field across the surface membrane 19. Therefore, the charged electrodes 54 attract charged particles 26A and 26B. Particles 26A and 26B may both be positively charged. More generally, a mechanism for applying voltage across the surface membrane 19 and the collector electrodes 54 may be provided.

[0188] Therefore, particles 26A and 26B are charged by plasma 52 and subsequently attracted to collector electrode 54. In this way, particles 26A and 26B are removed from the surface membrane 19.

[0189] Collector electrode 54 may be in the form of a plate substantially covering the entire surface film 19. This makes it a zone cleaning method (i.e., the entire surface area of ​​the surface film 19 can be cleaned simultaneously using this method). The plate may be a metal plate. The plate may be flat. In another embodiment, collector electrode 54 may comprise a grid of electrodes.

[0190] When the power supply 56 is turned on, particles 26A and 26B can remain attached to the collector electrode 54. Therefore, the membrane 19 can be removed while particles 26A and 26B are attached to the collector electrode 54. This prevents particles 26A and 26B from returning to the membrane 19 when the power to the collector electrode 54 is turned off.

[0191] Two retractable shields 58 may also be provided, configured to prevent particles 26A, 26B from returning to the membrane 19 when the power supply to the collector electrode 54 is disconnected. When the voltage supply 56 needs to be disconnected, the shields 58 can be moved to a suitable position between the electrode 54 and the membrane 19. Once the power is disconnected, the particles 19 can move freely away from the electrode 54, but cannot return to the membrane 19 again due to the obstruction of the shields 58. If it is necessary to restore power to restart the cleaning process, the shields 58 can be retracted to allow particles 26A, 26B to reach the collector electrode 54. In addition, the retractable shields 58 allow particles to be removed, for example, by detaching from the shields 58 at regular intervals. In some embodiments, only one shield 58 may be present (e.g., in the case of only a single collector electrode 54).

[0192] In some embodiments, if necessary, a heat-generating mechanism (heat source) 60 can also be used to induce particle transport from the membrane 19 to the collector electrode 54. The heat-generating mechanism 60 can heat the membrane 19 and induce particle transport. The heat-generating mechanism 60 can be a laser.

[0193] In one embodiment, frequency scanning can be used to couple to the particles. In other embodiments, a pulsed / white noise electrical signal can be used to couple to the particles.

[0194] This method has the advantage of simultaneously cleaning the entire surface of the membrane 19. It can clean the membrane 19 more effectively (i.e., remove more particles and / or do so in a faster time). Compared to other methods that may only use local cleaning or require prior location information of defects, it can clean the entire membrane 19 more quickly. Other previous systems form pores in the membrane during cleaning, which leads to loss of membrane strength and breakage.

[0195] The separation module 32 may include a vibration generating mechanism for generating mechanical oscillations of the membrane 19. Further details can be found in WO2020109152 (which is incorporated herein by reference in its entirety).

[0196] The vibration generating mechanism may include an excitation electrode and a mechanism for applying a time-varying voltage across the excitation electrode and the membrane 19. In other embodiments, a plurality of (e.g., two) excitation electrodes may be present. The vibration generating mechanism for inducing mechanical oscillations of the membrane 19 may also induce mechanical oscillations of particles 26A, 26B located on the membrane 19. Such oscillations of these particles 26A, 26B located on the membrane 19 may be sufficiently large to remove the particles from the membrane 19.

[0197] The separation module 32 may include an electric field generating mechanism for transporting particles away from the surface membrane 19. The electric field generating mechanism may include a collector electrode and a mechanism for applying a voltage across the surface membrane 19 and the collector electrode. In an embodiment, the excitation electrode and the collector electrode may be the same part.

[0198] Any particles 26A, 26B removed by the vibration generating mechanism to induce mechanical oscillations are mainly transported away from the membrane 19 by inertia, because the particles initiated by the vibrating membrane maintain their momentum (corresponding to a velocity of 0.1 to 10 m / s).

[0199] Previous systems for removing particles from a membrane before it is placed into a lithography apparatus have shown to be less efficient than lithography apparatuses (LA) in releasing particles from the membrane. Lithography apparatuses (LA) have multiple pressure sources (i.e., cleaning mechanisms) that act on particle release. Vibration is particularly important. Furthermore, they possess many states that can affect particle release through a reduction in adhesion (such as photons, electrons, plasma, free radicals, and heat). Many different physical effects can affect the reduction of adhesion in lithography apparatuses (LA). This includes, but is not limited to, EUV photons, electrons, vacuum, plasma, free radicals, and heat.

[0200] Previous systems used to remove particles may remove them via vibration (albeit in a manner different from that used in lithography equipment LA). However, these previous systems do not include most other adhesion-reducing agents. This results in reduced release and insufficient cleaning efficiency.

[0201] The device 20, comprising multiple modules, can be used to mimic and exceed the release of particles in an EUV lithography apparatus LA. The device 20 can remove most or all of the particles that will be released in the lithography apparatus LA. This offers the advantages of reduced costs and increased productivity because the separation device 20 can be used to clean the film to the required standards.

[0202] Device 20 has advantages over other single-stage cleaner concepts because it encompasses multiple pressure sources present in the lithography device LA (e.g., one pressure source in each cleaning module). Therefore, it is capable of cleaning (i.e., removing) any particles that may cause problems in the lithography device LA. The pressure sources can be considered as corresponding to cleaning mechanisms or adhesion reduction mechanisms.

[0203] A single actuator cleaner only mimics one of the largest effects in the lithography apparatus (LA). This may be effective for some particles, but not for all. It is impossible to know the composition of the particles on the film from the outset. The film may contain particles of different materials. These particles may also change in the future due to desired and undesirable changes in the processing flow or plant conditions. Therefore, the film cleaner needs to be effective not only against current particles but also against any future particles. To achieve this, device 20 can mimic some or all of the processes occurring in the lithography apparatus (LA).

[0204] Device 20 provides the same pressure source as lithography device LA, but at a much lower cost because it does not include all the imaging features of lithography device LA. Furthermore, the pressure source in device 20, compared to lithography device LA, includes a boost factor (e.g., the vibrations in the separation module 32 used to remove particles can be approximately 100 to 1000 times stronger than in lithography device LA). Other pressure sources in device 20 may also exhibit boost compared to lithography device LA, such as in the presence of heat, reactive ions or free radical doses, or high-energy electron doses.

[0205] Some previous cleaning tools were based on inertial forces (e.g., via vibration), which are effective for relatively heavy, larger particles but less effective for relatively light, smaller particles. Some coatings shed particles due to the same inertial forces present in the lithography apparatus (LA). However, inertial force-based cleaning tools may be less effective for other coatings because particles can be released from them by, for example, electricity within the LA. Therefore, inertial force-based cleaning tools can clean coatings of particles that are different from those that can cause defects in the LA.

[0206] Figure 7 illustrates an electron beam generating mechanism 70 for generating an electron beam 72 to be incident on the back side of the coating 19 (i.e., in this embodiment, the side with the particles 26B to be removed). It should be understood that in other embodiments, the electron beam 72 may be incident on the front side of the coating 19 to clean the particles 26A on the front side of the coating 19. In this embodiment, the electron beam generating mechanism 70 is a removal mechanism (i.e., for removing particles from the coating) rather than a preparation mechanism (i.e., for reducing particle adhesion to the coating) as previously described. It should be understood that in some embodiments, the electron beam generating mechanism may be both a preparation mechanism and a removal mechanism.

[0207] An electron beam 72 irradiates the area on the membrane 19 where particles 26B are located. The electron beam 72 charges the membrane 19 and the particles 26B thereon with a negative charge. The fact that both the membrane 19 and particles 26B are negatively charged (i.e., have the same charge) means that there is electrostatic repulsion between particles 26B and the membrane 19. This repulsion between particles 26B and the membrane 19 can cause particles 26B to be removed from the membrane 19, thus cleaning the membrane 19.

[0208] Figure 8 illustrates the distribution of negative charge on particle 26B and the surface film 19 in more detail. The direction of the electric charge is shown by arrows (i.e., perpendicular away from the surface film 19). The surface film 19 may have a dielectric top layer on its back side (i.e., particle 26B can contact this dielectric layer). In this case, the electric charge is particularly efficient because the dielectric layer can accumulate a high charge, resulting in a large electrodischarge force. The surface film 19 may also have a dielectric top layer on its front side, that is, it may have dielectric surfaces on both the back and front sides of the surface film 19.

[0209] For maximum cleaning efficiency, the electron beam 72 should have high energy: preferably above 80 eV. Higher energy results in better cleaning. The electron beam 72 can be pulsed. Pulsed exposure is advantageous because it leads to high transient forces. The electron beam can be applied simultaneously with plasma. This is advantageous, at least for floating film systems, as it prevents the accumulation of drift potential and the final repulsive force from electrons in the electron beam. The plasma can be generated by a plasma generation mechanism.

[0210] Cleaning (i.e., removal of particles 26B) can be performed by targeting and detecting particles 26B. Alternatively, cleaning can be performed on the entire membrane 19. The latter option has the advantage of not being dependent on units of measurement. Cleaning the entire membrane 19 can be done using a relatively large electron beam spot that substantially covers the entire membrane 19, or by scanning a smaller electron beam spot across the membrane 19. This scanning can be performed using deflection coils, as in, for example, a scanning electron microscope (SEM) or a cathode ray tube (CRT) monitor.

[0211] In an embodiment, the electron beam generating mechanism may include a scanning electron microscope (SEM). This provides the advantage of in-situ imaging and evaluation cleaning of particles 26B and / or the coating 19. This can result in more time-saving cleaning. However, it should be understood that imaging is not necessary and only an electron beam is required for removing particles 26B from the coating 19. This can be done by using an electron gun.

[0212] Particles 26B repelled from the membrane 19 typically do not return to the membrane 19; for example, they may settle on the walls of the vacuum chamber surrounding the membrane 19 or be flushed by flow. However, in an embodiment, the removed particles 26B may be collected by an electrode 74 (e.g., any metal object), selected as appropriate. The electrode 74 can be considered a collector electrode. The electrode 74 attracts the released particles 26B because the particles 26B are negatively charged. If a positive voltage is present on the electrode 74, the attraction is effective, and if the electrode 74 is grounded, the attraction is also effective. In the latter case, there is a mirror force attracting the (negatively) charged particles 26B. The electrode 74 may be covered with a (thin) dielectric to prevent the particles 26B from losing their charge. Collecting the particles 26B has the advantage that they will not be redeposited on the membrane 19. In addition, the electrode 74 can enhance the electro-cleaning force—see above regarding the electric field generating mechanism for transporting particles 26B away from the membrane 19.

[0213] Embodiments of the present invention relate to apparatus and related methods for removing particles from thin films using an electric field. Specifically, some embodiments of the present invention are particularly suitable for and adapted to cleaning relatively thin, easily damaged films (such as, for example, surface films).

[0214] Some embodiments of the present invention utilize the fact that relatively thin films (such as, for example, surface films) are relatively flexible by inducing mechanical oscillations in the film. This, in turn, induces mechanical oscillations in particles located on the film. These oscillations of such particles located on the film can be large enough to remove the particles from the film. Any such particles removed by the mechanism for inducing the mechanical oscillations can then be transported away from the film using their own momentum. Examples of these embodiments are now described with reference to Figures 9 through 16. It should be understood that, in these embodiments, these mechanical oscillations can be used to clean components other than the (surface) film. []

[0215] A membrane cleaning apparatus 100 according to a first embodiment of the present invention will now be described with reference to Figures 9 to 12.

[0216] Figure 9 shows a cross-section through a membrane cleaning device 100, which includes a movable stage 106, a first cleaning component 110, a second cleaning component 210, a vacuum chamber 130, and a controller 190.

[0217] Figure 9 also shows the thin film assembly 104. The thin film assembly 104 includes a thin film 211 and a thin film support in the form of a conductive frame 108. The conductive frame 108 is a generally rectangular frame. One or more surfaces of the conductive frame 108 and the thin film 211 are coated with a conductive (e.g., metallic) coating 209 (see Figure 10) such that the conductive coating 209 is in electrical contact with the conductive frame 108. Alternatively, the film itself may contain a conductive material and extend to the film frame.

[0218] The first cleaning component 110 includes: a first voltage source 111, a first actuator 112, a first connector 114, a first isolator 115, a displacement sensor in the form of a first proximity sensor 116, and a time-varying electric field generator in the form of a first electrode 118.

[0219] The second cleaning component 210 includes: a second voltage source 211, a second actuator 212, a second connector 214, a second isolator 215, a displacement sensor in the form of a second proximity sensor 216, and a time-varying electric field generator in the form of a second electrode 218.

[0220] The movable stage 106, the thin film assembly 104, the first cleaning component 110 and the second cleaning component 210 are placed in the vacuum chamber 130.

[0221] The conductive frame 108 includes a central rectangular aperture. The lower surface of the outer portion of the thin film 211 is fixed to the upper surface of the conductive frame 108. Within the central rectangular aperture of the conductive frame 108, the inner portion of the thin film 211 is suspended above the movable stage 106. The conductive frame 108 of the thin film assembly 104 has a lower surface supported by the upper surface of the movable stage 106. The first electrode 118 is in the form of a combined excitation / collector electrode. The second electrode 218 is in the form of a combined excitation / collector electrode.

[0222] The membrane assembly 104 is positioned between the first cleaning component 110 and the second cleaning component 210. The first cleaning component 110 is positioned above the membrane 211, and the second cleaning component 210 is positioned below the membrane 211. The first cleaning component 110 is configured to be opposite the second cleaning component 210.

[0223] The lower surface of the first actuator 112 is connected to the upper surface of the first connector 114. The lower surface of the first connector 114 is connected to the upper surface of the first proximity sensor 116. The lower surface of the first connector 114 is connected to the upper surface of the first electrode 118. A first isolator 115 is positioned between the first proximity sensor 116 and the first electrode 118. A first voltage source 111 is electrically connected to the first electrode 118 at one end and electrically connected to ground (e.g., electrically connected to the vacuum chamber 130) at the other end (not shown for clarity). The lower surfaces of the first proximity sensor 116 and the first electrode 118 face the upper surface of the thin film 211.

[0224] The upper surface of the second actuator 212 is connected to the lower surface of the second connector 214. The upper surface of the second connector 214 is connected to the lower surface of the second proximity sensor 216. The upper surface of the second connector 214 is connected to the lower surface of the second electrode 218. A second isolator 215 is positioned between the second proximity sensor 216 and the second electrode 218. A second voltage source 211 is electrically connected to the second electrode 218 at one end and electrically connected to ground (e.g., electrically connected to the vacuum chamber 130) at the other end (not shown for clarity). The upper surfaces of the second proximity sensor 216 and the second electrode 218 face the lower surface of the thin film 211.

[0225] The conductive film 211 is effectively grounded to one of the following via capacitive coupling: the vacuum chamber 130 or the support stage 106.

[0226] The film 211 is pre-compressed (e.g., to a tension of 100 to 1000 MPa, such as 300 to 500 MPa). The film 211 has a thickness of 5 to 50 nm, typically 10 to 30 nm. The internal portion of the film 211 is freely oscillating mechanically above the movable stage 106.

[0227] In use, the movable stage 106 is configured to move in two dimensions within the plane of the conductive frame 108. The movement of the movable stage 106 is also configured to move the conductive frame 108 and the thin film 211, so that the thin film 211 can move within the cleaning device 100.

[0228] In use, the first linear actuator 112 and the second linear actuator 212 are operable to move independently of each other in one dimension perpendicular to the plane of the conductive frame 108.

[0229] In use, the first linear actuator 112 is operable to move the first connector 114. The first connector 114 is configured to provide a mechanical reference to the first electrode 118 and the first proximity sensor 116. Therefore, the first linear actuator 112 is operable to move the first electrode 118 and the first proximity sensor 116 relative to the thin film 211. The first connector 114 includes an insulator configured to electrically insulate the first electrode 118 and the first proximity sensor 116 from the first linear actuator 112.

[0230] In use, the second linear actuator 212 is operable to move the second connector 214. The second connector 214 is configured to provide a mechanical reference to the second electrode 218 and the second proximity sensor 216. Therefore, the second linear actuator 212 is operable to move the second electrode 218 and the second proximity sensor 216 relative to the thin film 211. The second connector 214 includes an insulator configured to electrically insulate the second electrode 218 and the second proximity sensor 216 from the second linear actuator 212.

[0231] In use, the first linear actuator 112 and the second linear actuator 212 are configured to move the first proximity sensor 116 and the second proximity sensor 216 to be equidistant from the thin film 211. In use, the first linear actuator 112 and the second linear actuator 212 are configured to move the first electrode 118 and the second electrode 218 to be equidistant from the thin film 211.

[0232] The first electrode 118 and the second electrode 218 are equidistant from the thin film 211 so that the excitation of the thin film 211 can be balanced. For example, when in action, the electrodes 118 and 218 apply forces to the thin film 211 in opposite directions, and the combined time-averaged force on the thin film 211 from the electrodes 118 and 218 is less than 10% (e.g., preferably less than 1%) of the time-averaged force from either of the electrodes 118 and 218.

[0233] In use, the movable stage, the first linear actuator 112 and the second linear actuator 212 are operable to position the first cleaning component 110 and the second cleaning component 210 in three dimensions relative to the film 211.

[0234] In use, a first voltage source 111 is configured to apply a first voltage to a first electrode 118, and a second voltage source 211 is configured to apply a second voltage to a second electrode 218. The first and second voltages are relative to ground (not shown). The first electrode 118 and the second electrode 218 are configured to approach the thin film 211 to generate a time-varying electric field.

[0235] The first isolator 115 includes an insulator configured to electrically insulate the first electrode 118 from the first proximity sensor 116. The second isolator 215 includes an insulator configured to electrically insulate the second electrode 218 from the second proximity sensor 216.

[0236] In use, the first proximity sensor 116 is configured to measure the distance between the first proximity sensor 116 and the surface of the thin film 211 closest to the first proximity sensor 116. The first proximity sensor 116 is configured to illuminate the thin film 211 with a first measurement beam 117 and measure at least one property of a portion of the first measurement beam 117 reflected by the thin film 211 to measure the distance between the first proximity sensor 116 and the surface of the thin film 211 closest to the first proximity sensor 116. The first proximity sensor 116 is configured to provide the controller 190 with data corresponding to the distance between the first proximity sensor 116 and the surface of the thin film 211 closest to the first proximity sensor 116.

[0237] In use, the second proximity sensor 216 is configured to measure the distance between the second proximity sensor 216 and the surface of the thin film 211 closest to the second proximity sensor 216. The second proximity sensor 216 is configured to illuminate the thin film 211 with a second measurement beam 217, and to measure at least one property of a portion of the second measurement beam 217 reflected by the thin film 211, in order to measure the distance between the second proximity sensor 216 and the surface of the thin film 211 closest to the second proximity sensor 216. The second proximity sensor 216 is configured to provide the controller 190 with data corresponding to the distance between the second proximity sensor 216 and the surface of the thin film 211 closest to the second proximity sensor 216.

[0238] Proximity sensors 116, 216 are used (e.g., in conjunction with controller 190) to position electrodes 118, 218 relative to thin film 211 with an accuracy of 10 µm. This is the highest accuracy required with the minimum reasonable clearance (i.e., between thin film 211 and electrodes 118, 218), and includes a safety margin for inaccuracies associated with local portions of thin film 211 that deviate from the entire plane of the thin film, the tilt of movable stage 106, and the blocks of conductive frame 108.

[0239] In use, proximity sensors 116 and 216 are operable to sense the displacement of the thin film more frequently than the frequency of the low eigenmodes of mechanical oscillations in the thin film 211. The low eigenmodes of the thin film 211 refer to at least one of the following mechanical oscillation eigenmodes of the thin film: mode 1 (e.g., fundamental / unipolar mode), mode 2 (e.g., dipole, long edge of the film), mode 3 (e.g., dipole, short edge of the film), mode 4 (e.g., quadrupole), etc. As an example, these low eigenmodes are in the range of 1 to 3 kHz.

[0240] Enabling proximity sensors 116 and 216 to sense the displacement of thin film 211 more frequently than in low-eigenmode enables a feedback loop controlled by controller 190, wherein the mechanical oscillations of thin film 211 are monitored, and if the measured displacement of thin film 211 is outside a predetermined range, the controller controls at least one characteristic of the time-varying electric field (i.e., generated by electrodes 118 and 218) (see FIG. 12). These feedback loops are described with respect to FIGS. 14 to 16.

[0241] In use, proximity sensors 116, 216 are operable to measure the displacement of thin film 211 at a frequency higher than at least one of the following: 0.1 kHz, 1 kHz, 10 kHz.

[0242] In use, proximity sensors 116, 216 are operable to measure the displacement of thin film 211 at a frequency lower than at least one of the following: 1 kHz, 10 kHz, 100 kHz, 1000 kHz.

[0243] The first electrode 118 (e.g., in the form of a combined excitation / collector electrode) and the thin film 211 are not part of a closed circuit. Therefore, in use, when a voltage is applied by the first voltage source 111, charge can accumulate on the first electrode 118 and the thin film 211. The second electrode 218 (e.g., in the form of a combined excitation / collector electrode) and the thin film 211 are not part of a closed circuit. Therefore, in use, when a voltage is applied by the second voltage source 211, charge can accumulate on the second electrode 218 and the thin film 211. This effect is similar to the charging of plates in a capacitor.

[0244] In use, the first voltage source 111 and the second voltage source 211 are configured to alternately apply voltages to the first electrode 118 and the second electrode 218 (e.g., such that a net electrostatic force is applied to the thin film 211 at any instant). Alternatively, the first voltage source 111 and the second voltage source 211 are configured to apply opposite voltages to the first electrode 118 and the second electrode 218 (e.g., to apply a net electrostatic force to the thin film 211).

[0245] The charge accumulated on the first electrode 118 and the thin film 211 generates an electrostatic attraction between the first electrode 118 and the thin film 211. The charge accumulated on the second electrode 218 and the thin film 211 generates an electrostatic attraction between the second electrode 218 and the thin film 211. Since the thin film 211 is relatively thin and therefore flexible, the thin film 211 will deform due to this attraction.

[0246] In some embodiments of the invention, electrostatic forces are generated near the thin film assembly 104 by utilizing the accumulation of charge. Specifically, mechanical oscillations are induced in the thin film 211 by configuring the time characteristics of these electrostatic forces. This is achieved according to the present embodiment of the invention by applying a time-varying voltage across the first electrode 118, the second electrode 218, and the thin film 211. The time-varying voltage used for this purpose comprises pulses of a plurality of time intervals. This mechanism is described in detail below with respect to Figures 11a and 11b.

[0247] A time-varying voltage is applied to produce a pressure pulse with an electrostatic pressure of 10 to 1000 Pa, for example, 100 Pa. The time-varying voltage is applied for a duration of 10 to 1000 ns (e.g., 100 ns). The time-varying voltage has an average repetition rate of 10 to 1000 kHz, for example, 100 kHz. The time-varying voltage has a peak pulse repetition rate varying in the range of 0.1 to 10 MHz to cause the first / second / third harmonic frequencies to resonate with the particle's resonance, which can be treated for simplicity as mass on a massless spring for optimal resonant excitation.

[0248] The pressure pulse and the time-varying voltage have the same duration. A time-varying voltage (e.g., a voltage pulse) is applied to a device with a cross-section S. 1 to 5000 mm^2, for example S Electrodes ranging from 10 to 1000 mm². This is to provide the required electrostatic pressure (P = 1 / 2 ε₀E²). 100 Pa), electrode positioning (h) within 0.5 mm to 2.5 mm from the thin film.

[0249] One or more vacuum pumps (not shown) may be provided to control the pressure within the vacuum chamber 130. Specifically, the vacuum pump device (not shown) may be used to reduce the pressure in the vacuum chamber 130 to near-vacuum conditions. For example, one or more vacuum pumps may be operated to reduce the pressure within the vacuum chamber 130 to <10⁻³ mBar, preferably to <10⁻⁶ mBar. The pressure in the vacuum chamber 130 is configured to be equal on opposite sides of the plane of the thin film 211 (e.g., parallel to the plane of the conductive frame 108).

[0250] The controller 190 is electrically connected to a first proximity sensor 116, a second proximity sensor 216, a first voltage source 111, and a second voltage source 211. In use, the controller 190 is operable to control the first electrode 118 and the second electrode 218 based at least on the measured displacement of the thin film 211 measured by the first proximity sensor 116 and the second proximity sensor 216, to change at least one characteristic (e.g., amplitude, frequency, phase) of the time-varying electric field generated by the first electrode 118 and the second electrode 218 near the thin film 211.

[0251] The low intrinsic modes to be suppressed are large (i.e., amplitude), meaning that it is not important that each proximity sensor 116, 216 is removed from its respective electrode 118, 218, because the distance between each proximity sensor 116, 216 and its respective electrode 118, 218 is much smaller than the wavelength of the mechanical oscillation mode to be suppressed.

[0252] Thin film cleaning apparatus 100 can be used to clean thin film 211, as described herein. In use, thin film cleaning apparatus 100 is configured to clean a first local portion of thin film 211, and then a movable stage 106 is used to position a second local portion for cleaning. After cleaning the second local portion of thin film 211, the movable stage 106 is used to position a third local portion for cleaning, and this cycle is repeated until the entire thin film 211 has been cleaned. Local portions are typically larger than electrodes 118, 218. Typically, each local portion of thin film 211 overlaps with at least one adjacent local portion of the film.

[0253] Thin film 211 may be surface film 16 and may be formed of a material with high or medium conductivity, such as doped polycrystalline silicon, or metal silicide, or doped metal silicide, or doped metal carbide, or doped metal nitride, or any combination of the above materials.

[0254] Specifically, the device 100 is adapted to prevent damage to the thin film 211 caused by mechanical oscillation amplitude exceeding a predetermined range. Damage to the thin film 211 includes tearing or rupture. Runaway malfunctions can also cause damage to the thin film 211. For example, if the deformation of the thin film 211 relative to its stationary state exceeds a predetermined range, the stiffness of the thin film 211 cannot resist the electrostatic force from the closer of the first electrode 118 or the second electrode 218. In this case, the thin film 211 deforms further until it touches one of the electrodes 118 or 218 and is mechanically or by spark failure.

[0255] Device 100 is operable to prevent this runaway failure and to prevent damage to the membrane 211.

[0256] Figure 10 shows a cross-section through the film 211 cleaned by the film cleaning apparatus 100 when a voltage supplied by the voltage source 211 is applied across the combined excitation / collector electrode 218 and the conductive frame 108. For clarity, Figures 10 and 11a-11c are described with respect to the use of a single cleaning component 210 instead of two cleaning components 110, 210. Particles 240 disposed on the film 211 are also shown. Since the film 211 is generally flexible and the combined excitation / collector electrode 218 is generally rigid, the electrostatic attraction between the combined excitation / collector electrode 218 and the film 211 produces a mechanical deformation 301 of the film 211.

[0257] In embodiments of the invention, the voltage applied across the combined excitation / collector electrode 218 and the conductive frame 108 may follow the waveform 400 shown in FIG. 11a, which illustrates a curve of voltage V changing with time t. The voltage is time-varying. Specifically, the voltage waveform 400 is periodic, such that the voltage can be described as a pulse voltage 401. The pulse voltage 401 includes alternating on portions 402 and off portions 403. It should be understood that the voltage waveform 400 shown in FIG. 11a is merely an example of a pulse voltage 401 that can be generated by the voltage source 211. In other embodiments, alternative pulse shapes and pulse repetition frequencies and / or pulse patterns, such as bursts and series, may be used.

[0258] The pulsed voltage 401 shown in Figure 11a includes a DC component (where the break portion 403 corresponds to a non-zero potential difference between the combined excitation / collector electrode 218 and the conductive frame 108). In an alternative embodiment, a similar waveform 400 can be used but without a DC component (where the break portion 403 corresponds to a zero potential difference between the combined excitation / collector electrode 218 and the conductive frame 108). Using a pulsed voltage 401 with a DC component generates a stronger time-averaged electric field between the combined excitation / collector electrode 218 and the thin film assembly 208, which can improve the delivery of particles 240 toward the combined excitation / collector electrode 218, as described below.

[0259] A pulsed voltage 401 generates a pulsed electrostatic attraction between the combined excitation / collector electrode 218 and the thin film 211. During the on-state 402 of the pulsed voltage 401, the electrostatic attraction between the combined excitation / collector electrode 218 and the thin film 211 results in mechanical deformation 301 of the thin film 211 as described above. The pulsed pressure that generates this electrical charge is typically between 0.01 Pa and 100 Pa. After the pressure is applied, all or at least some portions of the thin film accelerate toward the electrode 218.

[0260] Compared to the period during the on-state 402, a reduced electrostatic attraction exists between the combined excitation / collector electrode 218 and the thin film 211 during the off-state 403 of the pulse voltage 401, which has a DC component. For embodiments of the pulse voltage 401 without a DC component, no electrostatic attraction exists between the combined excitation / collector electrode 218 and the thin film 211 during the off-state 403 of the pulse voltage 401. Therefore, during the off-state 403 of the pulse voltage 401 (whether or not it contains a DC component), the tension in the thin film 211 can cause acceleration of the thin film 211 in the opposite direction to the mechanical deformation 301 induced during the on-state 402 of the pulse voltage 401. When the on-state 402 and off-state 403 of the pulse voltage 401 are repeated, mechanical oscillations are induced in the thin film 211.

[0261] In embodiments of the invention, the voltage applied across the combined excitation / collector electrode 218 and the conductive frame 108 has a duty cycle of less than 10%. Advantageously, this limits the amount of heating of the thin film 211 by the current used to charge and discharge the capacitor formed by the thin film 211 and the combined excitation / collector electrode 218.

[0262] Particles 210 may exist on the surface of the thin film 211 facing the combined excitation / collector electrode 218.

[0263] The average over time is attributed to the net electric field between the combined excitation / collector electrode 218 and the thin film assembly 208 due to the pulse voltage 400.

[0264] Particles 240 with non-zero surface conductivity, disposed on the surface of the thin film 211 facing the combined excitation / collector electrode 218, possess charge acquired from the thin film 211, attributable to the pulse voltage 401. This charge causes an electrostatic force to attract the particles 240 toward the combined excitation / collector electrode 218.

[0265] Alternatively, particle 240 may have a charge acquired through surface triboelectric interaction with the thin film 211 facing the combined excitation / collector electrode 218. The charge of particle 240 may be positive or negative. In use, the polarity of voltage pulse 400 can be selected to provide attraction between the triboelectrically charged particles and electrode 218; to cover different materials (different characteristics of triboelectricity), the polarity of the voltage pulse (DC component and / or pulse component) can be varied. []

[0266] Each particle 240 existing on the surface of the thin film 211 will usually move along with the surface of the thin film 211 as the thin film oscillates, due to the van der Waals force attraction between the particle 240 and the surface of the thin film 211 where the particle 240 is located.

[0267] Each particle 240 on the pre-stressed film 211 can be considered an independent oscillator. The resonant frequency of this oscillator can vary depending on the properties of the particles 240 and the film 211.

[0268] For example, the resonant frequency of these particles 210 can vary with the mass M of the particles 240. The resonant frequency can vary with d: the ratio of the radius of the induced vibration 303 in the film 211 (defined by the amplitude of the oscillation and excitation frequency) to the size of the contact light spot 304 of the particles 240 on the film 211 (defined by typical short-range van der Waals force interactions). Typically, for the film 211 being cleaned using the film cleaning device 100, d can be between 100 and 1,000,000. The resonant frequency of these particles can also vary with the thickness 305, h, of the film 211. Typically, for the film 211 being cleaned using the film cleaning device 100, h can be between 10 nm and 100 nm. The resonant frequency can also vary with the pretension σ of the film 211. Typically, for the film 211 being cleaned using the film cleaning device 100, σ can be between 50 MPa and 500 MPa.

[0269] The fundamental frequency of an oscillator It can be described by the following equation: . For typical particle densities and particle radii between 0.5 µm and 5 µm, It can be between approximately 10 MHz and 0.3 MHz. If the excitation frequency applied to the thin film 211 is close to the resonant frequency of the particle 240, the amplitude 301 of the oscillation of the particle 240 can be increased. As the amplitude of the oscillation of the particle 240 increases, the thin film-particle distance 302 can also increase, because the inertia attributable to the particle acceleration can exceed the van der Waals force.

[0270] The magnitude of the Van der Waals force is inversely proportional to the square of the distance 302 between the atoms or molecules involved in the force. At some critical film-particle distances 302, the Van der Waals attraction between particle 240 and the surface of film 211 weakens to the point that the electrostatic force attracting particle 240 toward the combined excitation / collector electrode 218 (i.e., away from film 211) overcomes the Van der Waals force between particle 240 and film 211. Above this critical film-particle distance 302, particle 240 can therefore be removed from film 211. The particle 240 thereon will be positioned in the space between film 211 and combined excitation / collector electrode 218 and will be accelerated toward combined excitation / collector electrode 218.

[0271] Due to mass dependence, the resonant frequency of particle 240 varies with the size of particle 240. To remove particles 210 of varying sizes, pulse voltage 401 can be configured to induce oscillations in the thin film 211 within a specific frequency range. This induced oscillation frequency range of the thin film 211 can be termed the "excitation spectrum." The excitation spectrum is given by the Fourier transform of the waveform 400 of the pulse voltage 401 applied by voltage source 211. The components of the excitation spectrum are generated by the temporal characteristics of the pulse voltage 401. Relatively long repetitions produce components excited at relatively low frequencies, and vice versa.

[0272] Figures 11b and 11c show schematic diagrams of the excitation spectrum 404 corresponding to the pulse voltage 401 shown in Figure 11a. The excitation spectrum 404 schematically illustrates the relative electrostatic attraction applied to the thin film. It depends on the oscillation frequency used to apply this force. The excitation spectrum 404 includes a first part 405 and a second part 406.

[0273] The first portion 405 of the excitation spectrum 404 is generated by the temporal characteristics of the pulse voltage 401 having the longest duration: the pulse time period 407 of the pulse voltage 401. The center frequency 408 of the first portion 405 is defined by the reciprocal of the time period 407 (this center frequency 408 may be referred to as the pulse frequency or repetition rate). In some embodiments, the repetition rate of the pulse voltage 401 may be in the range of 30 kHz to 30 MHz. The shaded area 409 in Figure 11c corresponds to the shift of the center frequency 408 of the first portion 405 by modulating the time period 407. An increase in the time period 407 results in a decrease in the center frequency 408 of the first portion 405 (and vice versa).

[0274] The second portion 406 of the excitation spectrum 404 is generated by the temporal characteristics of a pulse voltage 401 with a duration shorter than that of time interval 407. The second portion 406 is defined by: the full width at half maximum (FWHM) 410 of the on-state portion 402 of the pulse voltage 401; and the rise time 411 and fall time 412 of the pulse voltage 401. The lower frequency 413 of the second portion 406 is defined by the reciprocal of FWHM 410. The higher frequency 414 of the second portion 406 is defined by the reciprocal of any shortest duration other than rise time 411 and fall time 412. The shaded area 415 in Figure 11c corresponds to the shifting of the lower frequency 413 and higher frequency 414 of the second portion 406 by modulating FWHM 410 and the rise time 411 and fall time 412. An increase in FWHM 410 results in a decrease in the lower frequency 413 of the second portion 406 (and vice versa). An increase in any of the shortest durations other than rise time 411 and fall time 412 results in a decrease in the higher frequency 414 of the second part 406 (and vice versa). []

[0275] The pulse voltage 401 shown in Figure 11a is relatively simple. It can therefore be easily implemented by someone skilled in the art. Advantageously, although the waveform 400 of the pulse voltage 401 is simple, it provides several configurable parameters (including time period 407, FWHM 410, rise time 411, and fall time 412), which can be selected (and changed) to achieve the desired excitation spectrum.

[0276] Alternatively, to use the pulse voltage 401 in the form shown in Figure 11a, an arbitrary function generator connected to the voltage amplifier can be used to generate any desired pulse shape that can be configured to induce the desired excitation spectrum.

[0277] In this embodiment, the voltage waveform 400 shown in FIG11a can be considered to have a general shape and have one or more parameters (e.g., any one of time period 407, FWHM 410, rise time 411, and fall time 412), which can be selected (and changed) to achieve the desired excitation spectrum. It should be understood that in other embodiments, different voltage waveforms may be used, but they can also be considered to have a general shape and have one or more parameters that can be selected (and changed) to achieve the desired excitation spectrum.

[0278] In the current embodiment, the combined excitation / collector electrode 218 and the thin film assembly 208 are positioned such that the spacing between the combined excitation / collector electrode 218 and the thin film 211 is between 0.5 mm and 2.5 mm.

[0279] In the current embodiment, the pulse voltage 401 applied across the combined excitation / collector electrode 218 and the conductive frame 108 has a maximum potential difference between 100 V and 10000 V.

[0280] In the current embodiment, the net (time-averaged) electric field (attributed to the pulse voltage 401) between the combined excitation / collector electrode 218 and the thin film assembly 208 has a field strength greater than 10 V m⁻¹ or less than -10 V m⁻¹.

[0281] In the current embodiment, the pulse voltage 401 is configured to excite the thin film 211 (and thereby the particles 210 disposed on the thin film 211) to oscillate in a frequency range between 30 kHz and 30 MHz. For example, the pulse voltage 401 may be configured to excite the thin film 211 to oscillate in a frequency range between 100 kHz and 10 MHz.

[0282] In the current embodiment, the pulse voltage 401 is not a sinusoidal voltage. By ensuring that the appropriate disconnection segment 403 is incorporated into the pulse shape, the power dissipation entering the conductive coating 209 on the thin film assembly 208 can be kept low. This can be used to allow radiative cooling to maintain the temperature of the thin film 211 within safe limits.

[0283] Using the configuration described above, the thin film cleaning device 100 can remove particles 210 with a size between 0.5 and 5 μm from the thin film 211.

[0284] The pulse voltage 401 can be applied as a single pulse train. One pulse train can immediately follow another. A single pulse train can be applied with the polarity of the pulse voltage reversed within a continuous pulse train. This can be used to release both negatively charged and positively charged triboelectric particles and attract them to the collector electrode. The duration of each pulse train can be configured so that the particles 210 have sufficient time to be transported to the combined excitation / collector electrode 218 before the application of the next pulse train (with reverse voltage polarity). It should be understood that charged particles can typically discharge upon contact with the excitation / collector electrode 218. Therefore, when the voltage polarity is reversed, these particles are not transported back to the thin film 211.

[0285] Figure 12 shows the same cross-section as that in Figure 9 through the membrane cleaning device 100, except that the membrane 211 in Figure 12 is mechanically oscillating rather than fixed. Therefore, the membrane 211 in Figure 12 deviates from the stationary plane of the membrane 211.

[0286] Figure 12 also shows a predetermined range in the form of an acceptable oscillation region of the thin film 211, defined between an upper critical deviation plane 660 and a lower critical deviation plane 662. The upper critical deviation plane 660 and the lower critical deviation plane 662 are arranged parallel to the plane of the conductive frame 108. The upper critical deviation plane 660 is positioned closer to the first cleaning member 110, and the lower critical deviation plane 662 is positioned closer to the second cleaning member 210. The upper critical deviation plane 660 and the lower critical deviation plane 662 correspond to displacements of the thin film 211 that are large enough to pose a risk of damage to the thin film 211 due to runaway failure.

[0287] The predetermined displacement range includes the displacement of at least a partial portion of the film 211 relative to the film 211 when it is at rest, and the displacement has a value smaller than at least one of the following: 10 µm, 100 µm, 1000 µm.

[0288] In use, the first displacement sensor 116 measures the displacement of the portion of the thin film 211 closest to the first displacement sensor 116. If the maximum amplitude of the mechanically oscillating thin film 211 becomes large enough that the displacement of the portion of the thin film 211 measured by the first displacement sensor 116 relative to the thin film 211 at rest is closer to the first displacement sensor 116 than the upper critical deviation plane 660, then the controller 190 controls at least one characteristic of the time-varying electric field generated by the first electrode 118 and the second electrode 218.

[0289] In use, the second displacement sensor 216 measures the displacement of the portion of the thin film 211 closest to the second displacement sensor 216. If the maximum amplitude of the mechanically oscillating thin film 211 becomes large enough that the displacement of the portion of the thin film 211 measured by the second displacement sensor 216 relative to the thin film 211 at rest is closer to the second displacement sensor 216 than the lower critical deviation plane 662, then the controller 190 controls at least one characteristic of the time-varying electric field generated by the first electrode 118 and the second electrode 218.

[0290] The controller 190 controls at least one characteristic of the time-varying electric field generated by the first electrode 118 and the second electrode 218 by controlling the first voltage source 111 and the second voltage source 211. The characteristic of the time-varying electric field generated by the first electrode 118 and the second electrode 218 is at least one of amplitude, frequency, and phase.

[0291] At least one characteristic of the time-varying electric field generated by the first electrode 118 and the second electrode 218 is controlled according to at least one of the embodiments described with respect to Figures 13 to 16.

[0292] Figure 13 shows a flowchart illustrating a method 700 for removing particles from film 211 according to another embodiment. Method 700 is adapted to prevent this runaway failure as described with respect to Figure 9, in order to prevent damage to film 211.

[0293] Method 700 includes steps 710, 712, 714, and 716, which are: inducing mechanical oscillation of the thin film using a time-varying electric field to remove particles from the thin film 710; measuring the displacement of the thin film relative to the thin film when it is at rest 712; determining whether the measured displacement of the thin film is outside a predetermined range 714; and if the measured displacement of the thin film is outside the predetermined range, controlling at least one characteristic of the time-varying electric field 716.

[0294] Steps 710, 712, 714, and 716 are executed sequentially. Step 710 is executed after step 716, so that method 700 forms a loop of steps 710, 712, 714, and 716.

[0295] Figure 14 shows a flowchart illustrating a method 800 for removing particles from film 211 according to another embodiment. Method 800 is adapted to prevent this runaway failure as described with respect to Figure 9, in order to prevent damage to film 211.

[0296] Method 800 includes steps 810, 812, 814, 816, 818, 820, and 822, which are: inducing mechanical oscillation of the thin film using a time-varying electric field to remove particles from the thin film 810; measuring the displacement of the thin film relative to the thin film when it is at rest 812; determining whether the measured displacement of the thin film is outside a predetermined range 814; reducing the amplitude of the time-varying electric field 816; waiting for a holding time 818; measuring the displacement of the thin film relative to the thin film when it is at rest 820; and determining whether the measured displacement of the thin film is outside a predetermined range 822.

[0297] First, step 810 is executed, followed by step 812 and then step 814. If it is determined in step 814 that the measured displacement of the film 211 is not outside the predetermined range, then method 800 returns to step 810. If it is determined in step 814 that the measured displacement of the film 211 is outside the predetermined range, then step 816 is executed. Step 816 is followed by step 818, then step 820, and then step 822. If it is determined in step 822 that the measured displacement of the film 211 is not outside the predetermined range, then method 800 returns to step 810. If it is determined in step 822 that the measured displacement of the film 211 is outside the predetermined range, then method 800 returns to step 818.

[0298] Step 816 (i.e., reducing the amplitude of the time-varying electric field) is performed by the controller 190 by at least one of the following: reducing the voltage applied to the first electrode 118 and the second electrode 218 by the first voltage source 111 and the second voltage source 211 respectively; or stopping the voltage applied to the first electrode 118 and the second electrode 218 by the first voltage source 111 and the second voltage source 211 respectively.

[0299] Step 818 (i.e., the holding time) is performed to reduce the amplitude of the mechanical oscillation of the thin film 211. The holding time is at least one of the following: a predetermined amount of time; or determined based on a measurement of the displacement of the thin film 211 relative to the thin film 211 when it is at rest. For example, the holding time is 10 to 100 s.

[0300] Figure 15 shows a flowchart illustrating a method 900 for removing particles from film 211 according to another embodiment. Method 900 is adapted to prevent this runaway failure as described with respect to Figure 9, in order to prevent damage to film 211.

[0301] Method 900 includes steps 910, 912, 914, 916, 918, 920, and 922, which are: inducing mechanical oscillation of the thin film using a time-varying electric field to remove particles from the thin film 910; measuring and recording time-varying displacement data of the thin film relative to the thin film when it is at rest 912; determining whether the measured displacement of the thin film is outside a predetermined range 914; changing the frequency of the time-varying electric field to reduce or remove the overlap between the frequency of the time-varying electric field and the frequency of the mechanical oscillation of the thin film 916; waiting for a holding time 918; measuring and recording time-varying displacement data of the thin film relative to the thin film when it is at rest 920; and determining whether the measured displacement of the thin film is outside a predetermined range 922.

[0302] Steps 910, 914, 918 and 922 are the same as steps 810, 814, 818 and 822, respectively.

[0303] Steps 912 and 920 include recording time-varying displacement data of the thin film 211 relative to the thin film 211 when it is at rest. Recording this time-varying displacement data involves measuring and storing the displacement data of the thin film 211 and corresponding timestamps, wherein each timestamp corresponds to the time when each displacement baseline data of the thin film 211 was measured. Recording this time-varying displacement data involves storing the time-varying displacement data so that the time-varying displacement data is retrievable in step 916.

[0304] Step 916 (i.e., changing the frequency of the time-varying electric field to reduce or remove the overlap between the frequency of the time-varying electric field and the mechanical oscillation frequency of the thin film 211) is performed by: acquiring the recorded time-varying displacement data; transforming the time-varying displacement data to the frequency domain using Fourier transform and extracting at least one mechanical oscillation frequency of the thin film; determining or acquiring a predetermined value of the low mechanical oscillation eigenmode of the thin film 211; and changing the frequency of the time-varying electric field to reduce or remove the overlap between the frequency of the time-varying electric field and the low eigenmode of the thin film 211.

[0305] Reducing or removing the overlap between the frequency of the time-varying electric field and the low intrinsic modes of the thin film 211 involves using the controller 190 to change the frequency of the voltages applied to the first electrode 118 and the second electrode 218 by the first voltage source 111 and the second voltage source 211, respectively.

[0306] Figure 16 shows a flowchart illustrating a method 1000 for removing particles from film 211 according to another embodiment. Method 1000 is adapted to prevent this runaway failure as described with respect to Figure 9, in order to prevent damage to film 211.

[0307] Method 1000 includes steps 1010, 1012, 1014, 1016, 1018, 1020, and 1022, which are: inducing mechanical oscillation of the thin film using a time-varying electric field to remove particles from the thin film 1010; measuring and recording time-varying displacement data of the thin film relative to the thin film when it is at rest 1012; determining whether the measured displacement of the thin film is outside a predetermined range 1014; changing the phase of the time-varying electric field to be out of phase with the mechanical oscillation of the thin film 1016; waiting for a holding time 1018; measuring and recording time-varying displacement data of the thin film relative to the thin film when it is at rest 1020; and determining whether the measured displacement of the thin film is outside a predetermined range 1022.

[0308] Steps 1010, 1014, 1018, and 1022 are the same as steps 810, 814, 818, and 822, respectively. Steps 1012 and 1020 are the same as steps 912 and 920, respectively.

[0309] Step 1016 (i.e., changing the phase of the time-varying electric field to be out of phase with the mechanical oscillation phase of the thin film 211) is performed by: acquiring the recorded time-varying displacement data; determining the mechanical oscillation phase of the thin film 211 from the recorded time-varying displacement data; and using the controller 190 to change the phase of the voltages applied to the first electrode 118 and the second electrode 218 by the first voltage source 111 and the second voltage source 211 respectively, so that the phase of the obtained time-varying electric field is out of phase with the mechanical oscillation phase of the thin film 211.

[0310] Method 1000 reduces the holding time compared to methods 800 and 900 (e.g., the recovery time of the measured displacement of the film 211 within a predetermined range after the mechanical oscillations of the film 211 subside). This increases the output of the film cleaning equipment 100.

[0311] The inherent damping of the membrane 211 is low, resulting in a holding time of, for example, 10 to 100 s. Method 1000 enables the pressure induced on the membrane 211 to instantly counteract the measured displacement of the membrane 211, thereby reducing the holding time by a factor of 10 to 100 relative to the inherent damping of the membrane 211. Therefore, method 1000 can suppress mechanical oscillations faster than the time required to induce them.

[0312] Method 1000 achieves increased efficiency of the thin film cleaning device 100 by reducing the gap between the thin film 211 and the electrodes 118, 218. For example, the cleaning pressure sequence can be executed in an inherently unstable configuration, subject to the constraint that the time-varying electric field can provide sufficiently rapid phase reversal with the mechanical oscillation of the thin film 211 to prevent instability and suppress the mechanical oscillation of the thin film 211 before the amplitude of the mechanical oscillation becomes critical (i.e., before the measured displacement of the thin film 211 exceeds a predetermined range).

[0313] Figure 17 illustrates an alternative embodiment of the film cleaning apparatus 1100 and film 211 according to the present invention. The apparatus 1100 in Figure 17 is the same as apparatus 100 or Figure 9, except that apparatus 1100 does not have a first cleaning component 110.

[0314] It should be understood that the various devices and methods described above are illustrative only, and the scope of the patent application is not limited to the devices and methods described above. Those skilled in the art will understand that various modifications can be made to the above devices and methods without departing from the scope of the appended patent application.

[0315] For example, with respect to FIG9, alternatively, the thin film 211 is grounded to the ground directly via a gap (e.g., 1 to 10 cm) from the conductive coating 209 to the ground by capacitive coupling. The thin film 211 can be grounded to the ground via the conductive frame 108 and / or the movable stage 106 by capacitive coupling.

[0316] Regarding Figure 9, alternatively, the thin film 211 is grounded directly to the ground via a gap (e.g., 1 to 10 cm) from the conductive coating 209 by capacitive coupling. The thin film 211 can be grounded via a wire that connects the outer portion of the conductive coating 209 to the ground.

[0317] Regarding Figure 9, instead of grounding the thin film 211, the thin film 211 can be DC biased relative to the ground.

[0318] Regarding Figure 9, instead of proximity sensors 116, 216, which can be operated to sense the displacement of thin film 211 at a frequency higher than the frequency of the low mechanical oscillation eigenmode of thin film 211, a relatively slow proximity sensor can be used. The relatively slow proximity sensor can be operated to sense the displacement of thin film 211 at substantially the same frequency as the low eigenmode of the mechanical oscillation in thin film 211.

[0319] Since linear actuators 112, 212 are not used during the cleaning of film 211 and the movable stage 106 moves slowly (e.g., below 100 µm / s) relative to the mechanical oscillation frequency of film 211, the changes measured by proximity sensors 116, 216 can be attributed to the mechanical oscillation of film 211.

[0320] The proximity sensors 116 and 216 are operable to measure the displacement of the thin film 211 at a frequency higher than at least one of the following: 100 Hz, 1000 Hz, 10,000 Hz.

[0321] The proximity sensors 116 and 216 are operable to measure the displacement of the thin film 211 at a frequency lower than at least one of the following: 1000 Hz, 10,000 Hz, and 100,000 Hz.

[0322] Regarding Figure 9, in addition to proximity sensors 116 and 216 for sensing mechanical oscillations of the thin film 211 and for setting the gap between electrodes 118 and 218 and the thin film 211, additional proximity sensors can be provided to proximity sensors 116 and 216.

[0323] Additional proximity sensors can be used to sense the mechanical oscillations of the thin film 211, and proximity sensors 116 and 216 are used to set the gap between electrodes 118 and 218 and the thin film 211. Measurements of the mechanical oscillations of the thin film 211 and the gap between electrodes 118 and 218 and the thin film 211 can be performed alternately. This allows for more frequent displacement measurements at the expense of the absolute accuracy of individual displacement measurements, which is preferable when the amplitude of the mechanical oscillations is large (e.g., >200 µm).

[0324] Regarding method 800, if it is determined that the measured displacement of the film 211 is outside the predetermined range, then method 800 reverses from step 822 to step 818, and method 800 can cycle back to step 816.

[0325] Regarding method 900, if it is determined that the measured displacement of the film 211 is outside the predetermined range, then method 900 reverses from step 922 to step 918, and method 900 can cycle back to step 916.

[0326] Regarding method 1000, if it is determined that the measured displacement of the film 211 is outside the predetermined range, then method 1000 reverses from step 1022 to step 1018, and method 1000 can cycle back to step 1016.

[0327] Regarding method 1000, in addition to step 1060 including changing the phase of the time-varying electric field to be out of phase with the mechanical oscillation phase of the thin film 211, the amplitude of the time-varying electric field can be increased, so that a greater electrostatic force is applied to suppress the mechanical oscillation of the thin film 211 more quickly compared to not increasing the amplitude of the time-varying electric field.

[0328] Regarding methods 800, 900, and 1000, instead of controlling at least one characteristic of the time-varying electric field in steps 816, 916, and 1060, waiting for a holding time 818 (during which the maximum displacement of the thin film 211 returns to a predetermined displacement range), and subsequently restoring at least one characteristic of the time-varying electric field to its value before the holding time in steps 810, 910, and 1010, at least one characteristic of the time-varying electric field can be controlled until the method of removing particles from the thin film is completed. Alternatively, at least one characteristic of the time-varying electric field can be controlled until a given local portion of the thin film 211 has been cleaned or the entire thin film 211 has been cleaned.

[0329] Each feature disclosed or described herein may be incorporated, individually or in any suitable combination with any other feature disclosed or described herein, into any of the different devices and methods described above. One or more features of any of the devices or methods described above with reference to the figures may have an effect or provide an advantage when used separately from one or more other features of the same device or method. Different combinations of features are also possible, in addition to the specific combinations of features of the devices and methods described above.

[0330] Those skilled in the art will understand that, in the foregoing description and the accompanying claims, positional terms such as 'above,' 'along,' and 'side' are used with reference to conceptual illustrations (such as those shown in the accompanying drawings). These terms are used for ease of reference but are not intended to be restrictive. Therefore, these terms should be understood as referring to an object in the orientation shown in the accompanying drawings.

[0331] While references may be specifically made herein to the use of lithography equipment in IC manufacturing, it should be understood that the lithography equipment described herein may have other applications. Possible other applications include the manufacture of integrated optical systems, guidance and detection for magnetic domain memory, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, etc.

[0332] Although embodiments of the invention may be specifically referenced herein in the context of lithography equipment, these embodiments can be used in other equipment. Embodiments of the invention may form part of mask inspection equipment, metrology equipment, or any equipment for measuring or processing objects such as wafers (or other substrates) or masks (or other patterning devices). Such equipment may generally be referred to as lithography tools. Such lithography tools may be used under vacuum conditions or ambient (non-vacuum) conditions.

[0333] Although the foregoing may have specifically referenced the use of embodiments of the invention in the context of optical lithography, it should be understood that, where the context permits, the invention is not limited to optical lithography and can be used in other applications (e.g., embossing).

[0334] Where the context permits, embodiments of the invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the invention may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. Machine-readable media may include any means for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, machine-readable media may include read-only memory (ROM); random access memory (RAM); magnetic storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.); and others. Furthermore, firmware, software, conventions, and instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are for convenience only, and such actions are actually caused by a computing device, processor, controller, or other means of executing firmware, software, conventions, instructions, etc., and in performing such actions, enable actuators or other means to interact with the physical world.

[0335] While specific embodiments of the invention have been described above, it should be understood that the invention may be practiced in ways other than those described, and the above description is intended to be illustrative rather than restrictive. Therefore, it will be apparent to those skilled in the art that modifications can be made to the described invention without departing from the scope and terms of the claims set forth below. 1. An apparatus for cleaning components supplied for use in a lithography device, the apparatus comprising at least one cleaning module or a plurality of cleaning modules. At least one or more cleaning modules contain a plurality of cleaning mechanisms, and The plurality of cleaning agencies includes: At least one preparation mechanism for reducing particle adhesion to the component and at least one removal mechanism for removing particles from the component, or a plurality of removal mechanisms for removing particles from the component. 2. The device as described in clause 1, wherein the device comprises a plurality of cleaning modules, and the device is configured such that components can be sequentially passed through the plurality of cleaning modules for cleaning. 3. The device as described in any of clauses 1 or 2, wherein the cleaning module or such cleaning module includes at least one separation module for removing particles from the components. 4. The device as described in clause 3, wherein the separation module is used to reduce particle adhesion to the component during or before particle removal from the component. 5. The equipment as described in any of clauses 3 or 4, wherein the cleaning module comprises: Multiple separate modules, and / or At least one separation module and at least one preparation module are provided for reducing particle adhesion to the component. 6. The equipment described in any of the preceding clauses, wherein the cleaning module or such cleaning modules are maintained in a vacuum or controlled gas environment. 7. The device as described in any of the preceding clauses, wherein the removal mechanism and / or preparation mechanism includes a vacuum generating mechanism. 8. The apparatus of any of the preceding clauses, wherein the preparation mechanism includes a heat generation mechanism configured to generate heat for drying components and / or particles in a vacuum environment. 9. The equipment of clause 8, wherein the pressure of water vapor or other oxygen-containing gas in the vacuum environment has at least one of the following: less than (1E-4 Pa), less than (1E-5 Pa), less than (1E-6 Pa), or less than (1E-7 Pa). 10. The equipment as described in any of clauses 8 or 9, wherein the heat generating mechanism includes a radiant heater, preferably a laser or IR lamp. 11. The device of any one of clauses 8 to 10, wherein the heat generation mechanism is configured such that at least one of the following is true: the radiant heat toward the boundary of the component is less than 1 W / cm²; the boundary of the component is in contact with the heat sink such that the boundary temperature is kept below 400°C; and / or the radiant heat power density at the component is less than 10 W / cm², preferably in the range of 1-5 W / cm² or 2-5 W / cm². 12. The apparatus of any of the preceding clauses, wherein the preparation mechanism includes a plasma generation mechanism for generating plasma in proximity to or around the component. 13. The equipment of clause 12, wherein the plasma generating mechanism is configured to generate a plasma having at least one of the following: a reducing agent, hydrogen, an inert gas, a reducing agent and an oxidizing agent and / or hydrogen and water. 14. The equipment of clause 13, wherein the ratio between the reducing agent and the oxidizing agent is greater than 100, preferably greater than 1000. 15. The equipment of any one of clauses 12 to 14, wherein the pressure used for plasma generation is in the range of 0.01 Pa to 100 Pa, preferably 0.1 Pa to 10 Pa. 16. The apparatus of any of the preceding clauses, wherein the preparation mechanism includes an electron beam generating mechanism for generating an electron beam to be incident on the side of the component having the particles to be removed. 17. The apparatus of clause 16, wherein the electron beam generating mechanism is configured to generate an electron beam in an environment comprising at least one of the following: a reducing agent, hydrogen, a reducing agent and an oxidizing agent and / or hydrogen and water. 18. The equipment of clause 17, wherein the ratio between the reducing agent and the oxidizing agent is greater than 100, preferably greater than 1000. 19. The equipment as described in any of clauses 17 or 18, wherein the environment has a pressure in the range of 0.01 Pa to 10 Pa. 20. The apparatus of any of the preceding clauses, wherein the preparation mechanism includes a VUV or EUV photon generation mechanism for generating VUV or EUV photons to be incident on the component. 21. The apparatus of clause 20, wherein the VUV or EUV photon generating mechanism is configured to generate VUV or EUV photons in an environment comprising at least one of the following: a reducing agent, hydrogen, a reducing agent and an oxidizing agent and / or hydrogen and water. 22. The apparatus of any of the preceding clauses, wherein the preparation mechanism includes a radical generation mechanism for generating hydrogen radicals in proximity to or around the component. 23. The apparatus of clause 22, wherein the free radical generating mechanism comprises at least one of a plasma generating mechanism and / or a hot filament. 24. The device of any of the preceding clauses, wherein the removal mechanism includes a vibration generating mechanism for generating mechanical oscillations of the component. 25. The apparatus of clause 24, wherein the vibration generating mechanism comprises at least one excitation electrode; and a mechanism for applying a time-varying voltage across at least one excitation electrode and the assembly. 26. The apparatus of any of the preceding clauses, wherein the removal mechanism includes a VUV photon generation mechanism for generating VUV photons to be incident on the component. 27. The apparatus of clause 26, wherein the VUV photon generating mechanism is configured to generate a VUV photon beam for substantially one-time irradiation of the entire surface or a portion thereof of the component, and wherein the VUV photon beam is scannable to irradiate the entire surface of the component. 28. The device of any of the preceding clauses, wherein the removal mechanism includes a plasma generating mechanism for generating plasma in proximity to or around the component. 29. The device of any of the preceding clauses, wherein the removal mechanism includes a heat-generating mechanism for inducing particle transfer from the component. 30. The device of any of the preceding clauses, wherein the removal mechanism includes an electric field generating mechanism for conveying particles away from the component. 31. The apparatus of clause 30, wherein the electric field generating mechanism includes a collector electrode; and a mechanism for applying a voltage across the component and the collector electrode. 32. The apparatus of clause 31, wherein the collector electrode comprises a grid of plates or electrodes that substantially cover all components. 33. The device as described in any of clauses 31 or 32, wherein the device includes one or more shielding elements configured to prevent particles from returning to the component when the power supply to the collector electrodes is disconnected. 34. The apparatus of any of the preceding clauses, wherein the removal mechanism includes an electron beam generating mechanism for generating an electron beam to be incident on the side of the component having the particles to be removed. 35. The device of clause 34, wherein the electron beam generating mechanism is configured to generate an electron beam having an energy in the range of 30 to 3000 eV, the current density at the component is in the range of 10 uA / cm2 to 10 mA / cm2, and / or the power dissipation at the component is less than 1 W / cm2. 36. The apparatus of any one of clauses 34 or 35, wherein the electron beam generating mechanism is configured such that the electron beam is pulsed. 37. The apparatus of any one of clauses 34 to 36, wherein an electron beam is combined with plasma. 38. The apparatus of any one of clauses 34 to 37, wherein the electron beam generating mechanism is configured to generate an electron beam having an energy greater than 80 eV. 39. The device of clause 25, wherein the device comprises: at least one displacement sensor for measuring the displacement of the component relative to the component when it is stationary; and a controller operable to determine whether the measured displacement of the component is outside a predetermined range, and if the measured displacement of the component is outside the predetermined range, to control a mechanism for applying a time-varying electric field to change at least one characteristic of the time-varying electric field. 40. The device as described in any of the preceding clauses, wherein the device is configured to allow one or more additional cleaning modules to be added to the device. 41. The device of any of the preceding clauses, wherein the component is at least one of the following: a surface film, an EUV transparent film, a dynamic airlock film, or an EUV spectral purity filter. 42. A film cleaning apparatus for removing particles from a thin film, the apparatus comprising: Thin film support, used to support the thin film; A time-varying electric field generator is used to induce mechanical oscillations in a thin film when supported by a thin film support to remove particles from the film; At least one displacement sensor for measuring the displacement of the film relative to the film when it is at rest while supported by a film support; and A controller operable to determine whether the measured displacement of the thin film is outside a predetermined range, and if the measured displacement of the thin film is outside the predetermined range, to control a time-varying electric field generator to change at least one characteristic of the time-varying electric field. 43. The apparatus of clause 42, wherein at least one displacement sensor is configured to measure the displacement of at least a local portion of the thin film relative to a local portion of the thin film when at rest. 44. The apparatus of clause 42, wherein a first displacement sensor is configured to measure the displacement of a portion of the thin film relative to the displacement of a portion of the thin film approaching a first excitation electrode when the film is at rest; and a second displacement sensor is configured to measure the displacement of a portion of the thin film relative to the displacement of a portion of the thin film approaching a second excitation electrode when the film is at rest. 45. The device of clauses 42 to 44, wherein the controller is operable to determine whether the measured displacement of the membrane is outside a predetermined range based on the measured maximum displacement of the membrane. 46. ​​The apparatus of clauses 42 to 45, wherein the controller is operable to control the time-varying electric field generator to reduce the maximum displacement of the thin film by changing at least one of the following characteristics of the time-varying electric field: amplitude; frequency; Phase. 47. The apparatus of clause 46, wherein the controller is operable to control the time-varying electric field generator to reduce the maximum displacement of the thin film by at least one of the following: Reduce the amplitude of the time-varying electric field; The frequency of the time-varying electric field can be changed to reduce or eliminate the overlap between the frequency of the time-varying electric field and the mechanical oscillation frequency of the thin film; The phase of the time-varying electric field is changed to be out of phase with the mechanical oscillation phase of the thin film. 48. The equipment as described in clauses 42 to 47, wherein the time-varying electric field generator comprises: At least one excitation electrode, which is positioned close to the surface of the thin film when supported by a thin film support; and A mechanism for applying a time-varying voltage across at least one excitation electrode to generate a time-varying electric field, thereby inducing mechanical oscillations of a thin film when supported by a thin film support. 49. The apparatus of items 42 to 48, wherein at least one time-varying electric field generator comprises: The first excitation electrode and the second excitation electrode, when supported by the thin film support, can be positioned close to different locations on two opposing surfaces of the thin film; and A mechanism for applying a time-varying voltage across a first excitation electrode and a second excitation electrode to generate a time-varying electric field for inducing mechanical oscillations of a thin film when supported by a thin film support. 50. The device of clause 49, wherein the time-varying electric field generator is configured such that there is a non-zero phase difference between the time-varying voltage applied to the first electrode and the time-varying voltage applied to the second electrode. 51. A method for cleaning components supplied for use in a lithography device, comprising: Use the following to clean the cleaning modules or components within multiple cleaning modules of the equipment: At least one removal mechanism for removing particles from the component; and at least one preparation mechanism for reducing particle adhesion to the component, or Multiple removal mechanisms for removing particles from components. 52. The method of clause 51, wherein the device comprises a plurality of cleaning modules, the method may further comprise causing components to be sequentially passed through the cleaning modules for cleaning. 53. The method of any of clauses 51 or 52 further includes: The component passes through multiple separate modules for removing particles from the component, and / or The component is passed through at least one preparation module to reduce particle adhesion to the component and then passed through at least one separation module. 54. The method of any one of clauses 51 to 53, wherein the removal mechanism includes a vibration generating mechanism for generating mechanical oscillations of the component using a time-varying electric field, the method further comprising: The component measures the displacement of the component relative to the component when it is stationary; determines whether the measured displacement of the component is outside a predetermined range, and if the measured displacement of the component is outside the predetermined range, controls at least one characteristic of the time-varying electric field. 55. A method for removing particles from a thin film for use in a lithography apparatus, comprising: Mechanical oscillations of the thin film induced by a time-varying electric field are used to remove particles from the thin film; Measure the displacement of the thin film relative to the thin film when it is at rest; Determine whether the measured displacement of the thin film is outside the predetermined range; and If the measured displacement of the thin film is outside the predetermined range, then at least one characteristic of the time-varying electric field is controlled. 56. The method of clause 55 further includes the ability to measure the displacement of the thin film at a frequency higher than at least one of the following: 1 Hz, 10 Hz, 100 Hz, 1000 Hz, 10,000 Hz. 57. The method of any one of clauses 55 to 56, wherein measuring the displacement of the thin film relative to the thin film at rest includes measuring the displacement of at least a portion of the thin film relative to a portion of the thin film at rest. 58. The method of any one of clauses 55 to 57, wherein the predetermined range includes the displacement of at least a partial portion of the film relative to the film when at rest, having a value smaller than at least one of the following: 10 µm, 100 µm, 1000 µm. 59. The method of any one of clauses 55 to 58, comprising determining whether the measured displacement of the thin film is outside a predetermined range based on the measured maximum displacement of the thin film. 60. The method of any one of clauses 55 to 59, wherein the characteristics of the time-varying electric field include at least one of the following: amplitude; frequency; Phase. 61. The method of clause 60, comprising controlling at least one characteristic of the time-varying electric field to reduce the maximum displacement of the thin film by at least one of the following: Reduce the amplitude of the time-varying electric field; The frequency of the time-varying electric field can be changed to reduce or eliminate the overlap between the frequency of the time-varying electric field and the mechanical oscillation frequency of the thin film; The phase of the time-varying electric field is changed to be out of phase with the mechanical oscillation phase of the thin film. 62. The method of any one of clauses 55 to 61, wherein inducing mechanical oscillation of the thin film comprises applying a time-varying voltage across at least one excitation electrode positioned close to the surface of the thin film. 63. The method of any one of clauses 55 to 62, wherein inducing mechanical oscillation of the thin film comprises applying a time-varying voltage to each of a first excitation electrode and a second excitation electrode positioned close to opposite surfaces of the thin film. 64. The method of clause 63, wherein there is a non-zero phase difference between the time-varying voltage applied to the first excitation electrode and the time-varying voltage applied to the second excitation electrode. 65. The method of any one of clauses 55 to 64 further comprises the ability to measure the displacement of the thin film at a frequency higher than at least one of the following: 1 Hz, 10 Hz, 100 Hz, 1000 Hz, 10,000 Hz. 66. A non-transitory computer-readable storage medium comprising instructions which, when executed by processing circuitry, cause the processing circuitry to perform a method as described in any one of clauses 51 to 65.

[0336] 1: Laser System 2: Laser Beam 3: Fuel Launcher 4: Plasma formation zone 5: Collectors 6: Central focus 7: Tin Plasma 8: Opening 9: Enclosure Structure 10: Faceted Field Mirror Device 11: Faceted pupil mirror device 13: Mirror 14: Mirror 15: Surface film assembly 17: Surface Frame 19: Surface film 20: Equipment 26A: Pollution particles 26B: Pollution particles 30: Prepare the module 32: Separation Module 34: Backup Module 36: Robot Module 38: Surface film library module 40: Vacuum Chamber Module 42: VUV photon generation mechanism 44: VUV photon beam 50: Plasma source 52: Plasma 54: Collector electrode / charged electrode 56: Voltage Supply 58: Retractable shielding component 60: Heat generation mechanism 70: Electron beam generating mechanism 72: Electron Beam 74: Electrode 100: Thin film cleaning equipment 104: Thin Film Assembly 106: Movable platform 108: Conductive framework 110: First cleaning component 111: First voltage source 112: First Actuator 114: First connector 115: First Isolator 116: First proximity sensor 117: First Measurement Beam 118: First electrode 130: Vacuum chamber 190: Controller 209: Conductive coating 210: Particles / Second Cleaning Component 211: Thin film / second voltage source 212: Second Actuator 214: Second connector 215: Second Isolator 216: Second Proximity Sensor 217: Second Measurement Beam 218: Second electrode / collector electrode 240: Particles 301: Amplitude / Mechanical Deformation 302: Spacing 303: Vibration 304: Contact light spot 305: Thickness 400: Waveform 401: Pulse Voltage 402: Connection Section 403: Disconnected part 404: Excitation Spectrum 405: Part One 406: Part Two 407: Time Period 408: Center Frequency 409: Shaded Area 410: Half Height Full Width 411: Rising Time 412: Descent Time 413: Lower frequency 414: Higher frequency 415: Shaded Area 660: Upper critical deviation plane 662: Lower critical deviation plane 700: Method 710: Steps 712: Steps 714: Steps 716: Steps 800: Method 810: Steps 812: Steps 814: Steps 816: Steps 818: Steps 820: Steps 822: Steps 900: Method 910: Steps 912: Steps 914: Steps 916: Steps 918: Steps 920: Steps 922: Steps 1000: Method 1010: Steps 1012: Steps 1014: Steps 1016: Steps 1018: Steps 1020: Steps 1022: Steps 1100: Membrane Cleaning Equipment B: EUV radiation beam B': Patterned EUV radiation beam IL: Irradiation system LA: Microfilm Equipment MA: Patterning device MT: Support structure PS: Projection system SO: Radiation source W: substrate WT: substrate table

Claims

1. An apparatus for cleaning a component supplied in a lithography device, the apparatus comprising at least one cleaning module or a plurality of cleaning modules, wherein the at least one cleaning module or the plurality of cleaning modules comprises a plurality of cleaning mechanisms, and wherein the plurality of cleaning mechanisms comprises: at least one preparing mechanism for reducing particle adhesion to the component and at least one removing mechanism for removing particles from the component, or a plurality of removing mechanisms for removing particles from the component, wherein the preparing mechanism comprises a plasma generating mechanism for generating a plasma in proximity to or around the component.

2. The device of claim 1, wherein the device includes the plurality of cleaning modules, and the device is configured such that the component can be sequentially passed through the plurality of cleaning modules for cleaning.

3. The device of claim 1 or 2, wherein the cleaning module or the cleaning modules include at least one separation module for removing particles from the component.

4. The device of claim 3, wherein the separation module is used to reduce the adhesion of particles to the component during or before the removal of the particles from the component.

5. The device of claim 4, wherein the cleaning modules comprise: a plurality of separation modules, and / or at least one separation module and at least one preparation module for reducing particle adhesion to the component.

6. The device as requested in item 1 or 2, wherein the cleaning module or such cleaning modules are maintained in a vacuum or controlled gas environment.

7. The device as claimed in claim 1 or 2, wherein the removal mechanism and / or the preparation mechanism includes a vacuum generating mechanism.

8. The apparatus of claim 1 or 2, wherein the preparation mechanism includes a heat-generating mechanism configured to generate heat to dry the components and / or the particles in a vacuum environment.

9. The apparatus of claim 8, wherein the pressure of water vapor or other oxygen-containing gas in the vacuum environment has at least one of the following: less than (1E-4 Pa), less than (1E-5 Pa), less than (1E-6 Pa), or less than (1E-7 Pa).

10. The apparatus of claim 8, wherein the heat generating mechanism comprises a radiant heater.

11. The device of claim 8, wherein the heat generating mechanism is configured such that at least one of the following is true: the radiant heat toward one boundary of the component is less than 1 W / cm²; one boundary of the component is in contact with a heat sink such that the boundary temperature is kept below 400°C; and / or the radiant heat power density at the component is less than 10 W / cm².

12. The apparatus of claim 1, wherein the plasma generating mechanism is configured to generate a plasma having at least one of the following: a reducing agent, hydrogen, an inert gas, a reducing agent and an oxidizing agent and / or hydrogen and water.

13. The equipment as requested in item 12, wherein the ratio between the reducing agent and the oxidizing agent is greater than 100.

14. The equipment as claimed in claim 1, wherein the pressure used for plasma generation is between 0.01 Pa and 100 Pa.

15. The device of claim 1 or 2, wherein the component is at least one of a surface film, an EUV transparent film, a dynamic airlock film, or an EUV spectral purity filter.

16. A method of cleaning a component for use in a lithography apparatus, comprising: cleaning the component in a cleaning module or a plurality of cleaning modules of the apparatus using: at least one removal mechanism for removing particles from the component, and at least one preparation mechanism for reducing the adhesion of the particles to the component, or a plurality of removal mechanisms for removing particles from the component, wherein the preparation mechanism includes a plasma generating mechanism for generating a plasma adjacent to or around the component.

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