Pattern Forming Apparatus Adjustment System and Method

Abstract

A mask adjustment system includes: a support structure for supporting a mask; a gas supply module for providing an air flow adjacent to the mask; and a bias module for controlling the electric potential of the mask. The bias module includes a first electrode, a second electrode, and a power supply. Each of the first electrode and the second electrode is spaced apart from the mask and faces the mask to at least partially overlap with the mask. The power supply is arranged to hold the first electrode at a positive voltage and the second electrode at a negative voltage, and these voltages make the voltage of the mask negative. The second electrode is arranged such that in use, the second electrode does not overlap with the image-forming portion of the mask.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to EP application 19203978.2, filed on October 18, 2019, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a patterning device adjustment system and related methods. Specifically, the present invention relates to a system for supporting a patterning device (within a lithographic apparatus), the system being arranged to reduce the chance that particles will impinge on the patterning device when the patterning device is so supported. The present invention also relates to related methods. Background Art

[0004] A lithographic apparatus is a machine configured to apply a desired pattern onto a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus can project, for example, a pattern present on a patterning device (e.g., a mask or reticle) onto a layer of radiation-sensitive material (resist) provided on a substrate.

[0005] To project a pattern onto a substrate, a lithographic apparatus can use electromagnetic radiation. The wavelength of this radiation determines the minimum size of the features that can be formed on the substrate. Compared to a lithographic apparatus that can use, for example, radiation having a wavelength of 193 nm, a lithographic apparatus using extreme ultraviolet (EUV) radiation having a wavelength in the range of 4 - 20 nm (e.g., 6.7 nm or 13.5 nm) can be used to form smaller features on a substrate.

[0006] Electromagnetic radiation is used to form an image of the patterning device on the substrate. Since any particles can affect the image formed on the substrate, it is important to keep the patterning device as free of contaminating particles as possible. It is desirable to provide a system for supporting a patterning device within a lithographic apparatus, the system being arranged to reduce the chance that particles will enter the patterning device when the patterning device is supported (e.g., relative to existing systems).

[0007] It is desirable to at least partially solve one or more problems associated with prior art systems, whether in the manner discussed herein or otherwise. Summary of the Invention

[0008] According to a first aspect of the present invention, there is provided a patterning device adjustment system for a lithographic apparatus, the patterning device adjustment system comprising: a support structure for supporting a patterning device, the support structure including a first portion for supporting an image forming portion of the patterning device and a second portion for supporting a non-image forming portion of the patterning device; a gas supply module operable to provide an air flow adjacent to the support structure; and a biasing module for controlling the electric potential of the patterning device when the patterning device is supported by the support structure, the biasing module including a first electrode, a second electrode and a power supply; wherein each of the first electrode and the second electrode is spaced apart from and faces the support structure so as to at least partially overlap with the support structure; wherein the power supply is arranged to hold the first electrode at a first positive voltage and the second electrode at a second negative voltage; wherein the second electrode is arranged such that the second electrode at least partially overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

[0009] In use, the patterning device may be supported by the support structure and irradiated with radiation (e.g., EUV radiation) to form an image of the patterning device on a substrate (e.g., a silicon wafer covered with a resist). Since particles may cause imaging errors, it may be necessary to prevent the particles from contacting the patterning device.

[0010] The patterning device adjustment system according to the first aspect of the present invention is advantageous and will now be discussed.

[0011] First, since particles can be entrained in the air flow and transported away from the patterning device, the air flow can be used to reduce the chance of such particles contacting the patterning device. However, in use, when the patterning device is exposed to radiation, the radiation can cause the gas to form a plasma. As these particles move through the plasma, these particles tend to become negatively charged (because electrons in the plasma have a higher mobility than ions in the plasma). In addition, in use, when the patterning device is exposed to radiation, the patterning device can become slightly positively charged due to the photoelectric effect. Therefore, a biasing force acting on these particles towards the patterning device may be generated, which is undesirable.

[0012] A patterning device supported by a support structure generally may include a central image forming portion surrounded by a non-image forming portion. The image forming portion may include reflective and non-reflective portions arranged in a pattern. In use, radiation is reflected by the image forming portion, and the reflected radiation can be used to form a patterned radiation beam. A projection system may be used to form an (resolution-limited) image of the image forming portion of the patterning device on a substrate. The electric potential of the patterning device may be floating (e.g., the patterning device may be electrically isolated from the support structure).

[0013] In a simple manner, a simple arrangement may be considered where a single bias electrode facing the patterning device MA is set to have, for example, a positive bias, so as to attract negatively charged particles towards the single bias electrode and away from the patterning device MA. However, due to the presence of the plasma, in this arrangement, the plasma will provide a conductive connection between the single bias electrode and the patterning device MA. As a result, the floating patterning device MA will be pulled to the same electric potential as the single bias electrode, and there will be no bias field acting on the negatively charged particles.

[0014] In contrast, the bias module of the patterning device conditioning system according to the first aspect of the present invention uses two bias electrodes. Both the first electrode and the second electrode are capacitively coupled to the patterning device supported by the support structure. The first electrode effectively pushes the voltage of the patterning device towards a first positive voltage, and the second electrode effectively pushes the voltage of the patterning device towards a second negative voltage. This arrangement causes the patterning device to tend to have an intermediate voltage between the first positive voltage and the second negative voltage. The intermediate voltage can be considered as a weighted average of the first voltage and the second voltage, and the weights can be determined by the capacitive coupling of the two electrodes to the patterning device. It should be understood that the capacitive coupling of each of the electrodes to the patterning device depends on the area of overlap of the electrode with the patterning device and the spacing between the electrode and the patterning device (as well as the dielectric constant of the medium provided between the electrode and the patterning device). It should be understood that by appropriately selecting these parameters as well as the first voltage and the second voltage, it can be ensured that the voltage of the patterning device (also referred to as the intermediate voltage) is negative.

[0015] The first positive voltage and the second negative voltage may be such that the voltage of the patterning device is negative.

[0016] It should be understood that the surface of the first electrode (maintained at the first positive voltage) will have a positive surface charge density, and the portion of the patterning device overlapping with the first electrode will have a substantially equal and opposite negative surface charge density. Thus, any negative charges present between the first electrode and the patterning device (e.g., negatively charged particles entrained in an air flow) will tend to be biased towards the first electrode and away from the patterning device. Since this keeps these particles away from the patterning device, it is advantageous.

[0017] Similarly, it should be understood that on the surface of the second electrode (maintained at the second negative voltage), a negative surface charge density will be induced, and on the portion of the patterning device that overlaps with the second electrode, a positive surface charge density that is substantially equal and opposite will be induced. Therefore, any negative charges (such as negative charges entrained in the gas flow) disposed between the second electrode and the patterning device will tend to be deflected towards the patterning device and away from the second electrode. However, the second electrode is arranged such that the second electrode overlaps with the second portion of the support structure (i.e., the portion of the support structure that supports the non-image forming part of the patterning device during use). Therefore, although these particles are pushed towards the patterning device, these particles are pushed towards the non-image forming part of the patterning device and thus do not affect the image formed on the substrate.

[0018] Since the patterning device is maintained at a negative intermediate voltage, any negative charges (such as negative charges entrained in the gas flow) that are not disposed between the first electrode and the patterning device or between the second electrode and the patterning device and are adjacent to the patterning device will also tend to be deflected away from the patterning device (assuming that the distance of these negative charges from the region of the patterning device that overlaps with the second electrode having a negative charge density is far enough).

[0019] Therefore, since the gas supply module can provide a gas flow that can be used to transport particles away from the patterning device, the patterning device adjustment system according to the first aspect of the present invention is advantageous. At the same time, the bias module is arranged to generally deflect negatively charged particles entrained in the gas flow away from all parts of the patterning device except the non-image forming part of the patterning device.

[0020] The gas flow provided by the gas supply module adjacent to the support structure is substantially parallel to the surface of the patterning device and can be referred to as a cross-flow.

[0021] The patterning device adjustment system may further include a scanning module that is operable to move the support structure in a scanning direction between at least a first end position and a second end position.

[0022] Such a scanning module can be used to perform dynamic scanning exposure. For example, the scanning module can be operable to move the support structure in the scanning direction relative to a support frame (wherein the support structure can be considered to be movably mounted to the support frame). The gas supply module and the bias module can also be mounted on the support frame. The gas supply module and the bias module can be fixed relative to the support frame, or at least independent of the support structure and movable relative to the support frame such that the gas supply module and the bias module can remain fixed when the support structure moves.

[0023] It should be understood that for such an embodiment including a scanning module, the second electrode can be arranged such that within at least a portion of the position range between the first end position and the second end position, the second electrode overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

[0024] The movement of the support structure between the first position and the second position can define an extended first portion region of the support structure (defined by all regions where the first portion of the support structure can be arranged) and an extended second portion region of the support structure.

[0025] The second electrode can be arranged such that when the support structure is arranged at the first end position, the second end position, or any position between the first end position and the second end position, the second electrode at least partially overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

[0026] With this arrangement, the second electrode can be considered to overlap with a fixed non-critical defect region. For example, the second electrode can include one or more extended electrodes extending along a non-scanning direction (perpendicular to the scanning direction).

[0027] The first electrode can be arranged such that the first electrode at least partially overlaps with the first portion of the support structure.

[0028] It should be understood that for an embodiment including a scanning module operable to move the support structure, the first electrode can be arranged such that within at least a portion of the position range between the first position and the second position, the first electrode at least partially overlaps with the first portion of the support structure.

[0029] The first electrode can include a plurality of first electrode elements.

[0030] The first electrode elements are arranged such that for any position within the position range between the first end position and the second end position, at least one of the first electrode elements at least partially overlaps with the support structure.

[0031] At least one of the first electrode elements at least partially overlaps with the first portion of the support structure.

[0032] The power supply is arranged to control the voltage of each of the first electrode elements according to the position of the support structure.

[0033] The second electrode can include a plurality of second electrode elements, and each of the second electrode elements can be arranged such that it at least partially overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

[0034] The second electrode may include two second electrode elements, each of the second electrode elements extending in a non-scanning direction perpendicular to the scanning direction. For example, the two second electrode elements may extend along an extension second part region of the support structure adjacent to an extension first part region of the support structure.

[0035] The power supply may be arranged to control the voltage of each of the second electrode elements according to the position of the support structure.

[0036] The first positive voltage and the second negative voltage may be such that the voltage amplitude of the patterning device is less than 50V.

[0037] It should be understood that if the voltage of the patterning device is negative, then when the voltage amplitude of the patterning device is less than 50V, the voltage of the patterning device is between -50V and 0V. For example, the applied voltage may be such that the voltage amplitude of the patterning device is less than 20V, for example on the order of 10V.

[0038] Maintaining the voltage of the patterning device at a relatively small and negative voltage can beneficially deflect the negatively charged particles away from the image forming part of the patterning device while reducing the current level through the (relatively thin) conductive film on the patterning device. Advantageously, this can reduce the heat of the patterning device and / or damage to the patterning device. In addition, once the voltage is removed from the first electrode and the second electrode, the patterning device can retain the bias voltage that it already has. By keeping this voltage at a lower level (e.g., below 50V), the chance of this voltage generating an arc or short circuiting with other metal components can be reduced.

[0039] One or more of the first electrode and the second electrode may be provided on the patterning device masking blade, and the edge of the patterning device masking blade defines a part of the outer periphery of the field region on the patterning device.

[0040] One or more of the first electrode and the second electrode may be provided on a part of the gas supply module.

[0041] Optionally, one or more of the first electrode and the second electrode may be provided on any other component within the lithographic apparatus.

[0042] According to a second aspect of the present invention, there is provided an assembly comprising: a patterning device adjustment system according to the first aspect of the present invention; and a patterning device supported by a support structure.

[0043] The patterning device may include a mask.

[0044] The patterning device may be provided with a surface film.

[0045] According to a third aspect of the present invention, there is provided a lithographic apparatus, comprising: an illumination system operable to output a radiation beam; a patterning device conditioning system according to the first aspect of the present invention, wherein the radiation beam output by the illumination system is directed to a support structure such that a patterning device supported by the support structure can impart a pattern in a cross-section of the radiation beam, thereby forming a patterned radiation beam; a substrate table for supporting a substrate; and a projection system for projecting the patterned radiation beam onto a target area of the substrate to form an image on the substrate.

[0046] According to a fourth aspect of the present invention, there is provided a method for conditioning a patterning device within a lithographic apparatus, the method comprising: supporting the patterning device; providing an air flow adjacent to the patterning device; providing a first electrode and a second electrode, each of the first electrode and the second electrode being spaced apart from and facing the patterning device to at least partially overlap the patterning device, wherein the second electrode is arranged such that the second electrode at least partially overlaps a non-image forming portion of the patterning device and does not overlap an image forming portion of the patterning device; and maintaining the first electrode at a first positive voltage and the second electrode at a second negative voltage such that the voltage of the patterning device is negative.

[0047] Since particles can be entrained in the air flow and transported away from the patterning device, the air flow can be used to reduce the chance of such particles coming into contact with the patterning device.

[0048] The method according to the fourth aspect of the present invention uses two biasing electrodes. Both the first electrode and the second electrode are capacitively coupled to the patterning device and can be used to generally deflect negatively charged particles entrained in the air flow away from all parts of the patterning device except the non-image forming portion of the patterning device.

[0049] According to a fifth aspect of the present invention, there is provided a method for conditioning a patterning device having a pellicle assembly within a lithographic apparatus, the method comprising: supporting the patterning device; providing an air flow adjacent to the patterning device; providing a first electrode and a second electrode, each of the first electrode and the second electrode being spaced apart from the patterning device and facing the patterning device to at least partially overlap the patterning device, wherein the second electrode is arranged such that the second electrode at least partially overlaps a portion of the patterning device and does not overlap the pellicle assembly, and wherein the first electrode is arranged such that the first electrode at least partially overlaps the pellicle assembly; and maintaining the first electrode at a first positive voltage and the second electrode at a second negative voltage such that the voltage of the patterning device is negative and the voltage of the pellicle is positive.

[0050] The methods according to the fourth and fifth aspects of the invention further include moving the support structure in a scan direction between at least a first end position and a second end position. The power supply may control the first positive voltage and / or the second negative voltage according to the position of the patterning device.

[0051] At least a part of the methods according to the fourth and fifth aspects of the invention may be performed by using a patterning device conditioning system according to the first aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

[0053] Figure 1 A lithographic system including a lithographic apparatus and a radiation source is depicted.

[0054] Figure 2 is a schematic plan view of a support structure forming part of the lithographic apparatus shown and a patterning device supported by the support structure; Figure 1

[0055] Figure 3A is Figure 2 a schematic plan view of the support structure and the patterning device shown in a first end position;

[0056] Figure 3B is Figure 2 a schematic plan view of the support structure and the patterning device shown in a second end position;

[0057] Figure 4A is Figure 1 a schematic cross - sectional view of a first cross - section of the patterning device on the support structure of the lithographic apparatus and a mask - blanking blade;

[0058] Figure 4B is Figure 1 a schematic cross - sectional view of a second cross - section of the patterning device on the support structure of the lithographic apparatus and a mask - blanking blade;

[0059] Figure 5 is a plan view showing Figure 1 a y - blanking blade and an x - blanking blade (shown in dashed lines) in a first configuration in the lithographic apparatus;

[0060] Figure 6A is a schematic plan view of an apparatus including a support structure (shown as for supporting a patterning device) and a biasing module and for controlling the electrical potential of the patterning device when supported by the support structure; and

[0061] Figure 6B shows Figure 6A ​Cross-sectional view of the device and the supported patterning device shown therein. Detailed Description

[0062] Figure 1 A lithography system is shown that includes a radiation source SO and a lithography apparatus LA. The radiation source SO is configured to generate an EUV radiation beam B and provide the EUV radiation beam B to the lithography apparatus LA. The lithography apparatus 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 table WT configured to support a substrate W.

[0063] The illumination system IL is configured to condition the EUV radiation beam B before the EUV radiation beam B is incident on the patterning device MA. Thus, the illumination system IL can include a faceted field mirror device 10 and a faceted pupil mirror device 11. The faceted field mirror device 10 and the faceted pupil mirror device 11 together provide the EUV radiation beam B with a desired cross-sectional shape and a desired intensity distribution. The illumination system IL can include other mirrors or devices in addition to or instead of the faceted field mirror device 10 and the faceted pupil mirror device 11.

[0064] After this conditioning, the EUV radiation beam B interacts with the patterning device MA. Due to this interaction, a patterned EUV radiation beam B’ is generated. 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 can include a plurality of mirrors 13, 14, the plurality of mirrors 13, 14 being configured to project the patterned EUV radiation beam B’ onto the substrate W held by the substrate table WT. The projection system PS can apply a reduction factor to the patterned EUV radiation beam B’, thereby forming an image having features smaller than the corresponding features on the patterning device MA. For example, a reduction factor of 4 or 8 can be applied. Although in Figure 1 it is shown that the projection system PS has only two mirrors 13, 14, the projection system PS can include a different number of mirrors (e.g., six or eight mirrors).

[0065] The substrate W can 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.

[0066] A relative vacuum can be provided in the radiation source SO, the illumination system IL, and / or the projection system PS, i.e., a small amount of gas (e.g., hydrogen) under conditions of a pressure far below atmospheric pressure.

[0067] For example, Figure 1The radiation source SO shown is of a type that can be referred to as a laser-produced plasma (LPP) source. A laser system 1, which can include, for example, a CO2 laser, is arranged to deposit energy into a fuel (such as tin (Sn) provided by, for example, a fuel emitter 3) via a laser beam 2. Although described below with tin, any suitable fuel can be used. The fuel can be, for example, in liquid form and can be, for example, a metal or an alloy. The fuel emitter 3 can include a nozzle configured to direct the tin, for example, in the form of droplets, along a trajectory towards a plasma formation region 4. The laser beam 2 is incident on the tin in the plasma formation region 4. Depositing the laser energy into the tin causes a tin plasma 7 to be generated in the plasma formation region 4. During the de-excitation and recombination of electrons with the ions of the plasma, radiation including EUV radiation is emitted from the plasma 7.

[0068] The EUV radiation from the plasma is collected and focused by a collector 5. For example, the collector 5 includes a near-normal incidence radiation collector 5 (sometimes more generally referred to as a normal incidence radiation collector). The collector 5 can have a multilayer mirror structure arranged to reflect EUV radiation (such as EUV radiation having a desired wavelength such as 13.5 nm). The collector 5 can be an elliptical configuration having two foci. As described below, the first focus can be at the plasma formation region 4, and the second focus can be at an intermediate focus 6.

[0069] The laser system 1 can be spatially separate from the radiation source SO. In this case, the laser beam 2 can be transmitted from the laser system 1 to the radiation source SO by means of a beam delivery system (not shown) including, for example, suitable steering mirrors and / or beam expanders and / or other optical devices. The laser system 1, the radiation source SO, and the beam delivery system can be considered together as a radiation system.

[0070] The radiation reflected by the collector 5 forms an EUV radiation beam B. The EUV radiation beam B is focused at the intermediate focus 6 to form an image at the intermediate focus 6 of the plasma present in the plasma formation region 4. The image at the intermediate focus 6 serves as a virtual radiation source for an illumination system IL. The radiation source SO is arranged such that the intermediate focus 6 is located at or near an opening 8 in an enclosure 9 of the radiation source SO.

[0071] Although Figure 1 the radiation source SO is depicted as a laser-produced plasma (LPP) source, any suitable source (such as a discharge-produced plasma (DPP) source or a free electron laser (FEL)) can be used to generate EUV radiation.

[0072] Embodiments of the present invention relate to a patterning device adjustment system for supporting a patterning device MA within a lithographic apparatus LA. The patterning device adjustment system is arranged to reduce the chance of particles impinging on the patterning device MA when the patterning device is supported. This is now discussed.

[0073] As Figure 2 Schematically shown, a patterning device MA supported by a support structure MT generally may include a central image forming portion 20 surrounded by a non-image forming portion 22. The image forming portion 20 may include reflective and non-reflective portions arranged in a pattern. In use, a radiation beam B is reflected by the image forming portion 20, and the reflected radiation beam B may be used to form a patterned radiation beam B'. The entire patterning device MA may be provided with a (relatively thin) conductive coating, which generally covers the central image forming portion 20 and the non-image forming portion 22. The electrical potential of the patterning device MA (specifically, the conductive coating) may be floating (e.g., the patterning device MA may be electrically isolated from the support structure MT).

[0074] It should be understood that since the support structure MT supports the patterning device MA, the support structure MT may be considered to include a first part and a second part, the first part being for supporting the image forming portion 20 of the patterning device MA (corresponding to Figure 2 the image forming portion 20 therein), and the second part being for supporting the non-image forming portion 22 of the patterning device MA (corresponding to Figure 2 the image forming portion 20 therein).

[0075] The support structure MT may be moved in the scanning direction so as to expose a larger area of the patterning device MA during a single dynamic scanning exposure. Now refer to Figure 3A and 3B for discussion. Figure 3A and 3B show schematic plan views of the support structure MT and the patterning device MA at two different positions.

[0076] The support structure MT is movably mounted within the region 24. Specifically, the support structure MT may move in the scanning direction indicated by the arrow 26 between a first end position (as Figure 3A shown) and a second end position (as Figure 3B shown).

[0077] Unless otherwise specified, in this specification, the following Cartesian coordinate set will be used. The scanning direction will be labeled as the y-direction. The direction that is also in the plane of the support structure MT and perpendicular to the scanning direction will be referred to as the non-scanning direction and labeled as the x-direction. The direction perpendicular to the plane of the support structure MT will be labeled as the z-direction.

[0078] The lithographic apparatus LA can be considered to include a scanning module that is operable to move the support structure MT along a scanning direction between at least a first end position and a second end position. For example, the scanning module is operable to move the support structure MT along the scanning direction relative to a support frame (schematically represented by the area 24) to which the support structure MT is considered to be movably mounted.

[0079] The movement of the support structure MT between the first and second positions defines an extended first part region 28 of the support structure MT, which is entirely locally defined by the first part of the support structure MT (or equivalently, the image forming part 20 of the patterning device MA) that can be provided. That is, the extended first part region 28 of the support structure MT is obtained by moving the first part of the support structure MT (or equivalently, the image forming part 20 of the patterning device MA) from a first end position (as Figure 3A shown) to a second end position (as Figure 3B shown).

[0080] The movement of the support structure MT between the first and second positions also defines an extended second part region of the support structure. The extended second part region can be entirely locally defined by the areas where the first part of the support structure MT (or equivalently, the image forming part 20 of the patterning device MA) cannot be provided. The extended second part region of the support structure MT includes two extended non-critical regions 30a, 30b.

[0081] The lithographic apparatus LA is provided with four mask occlusion blades that define the extent of the irradiated field on the patterning device MA. Reference is now made to Figure 4A and 4B and 5 for description. The illumination system IL is operable to illuminate an area of the patterning device MA disposed on the support structure MT. This area can be referred to as the slit of the illumination system IL and is at least partially defined by the four mask occlusion blades, which also define a substantially rectangular area on the patterning device that can receive radiation. The extent of the substantially rectangular area in a first direction (which can be referred to as the x direction) is defined by a pair of x occlusion blades 32, 34. The extent of the substantially rectangular area in a second direction (which can be referred to as the y direction) is defined by a pair of y occlusion blades 36, 38.

[0082] Each of the occlusion blades 32, 34, 36, 38 is arranged close to, but slightly offset from, the plane of the patterning device on the support structure MT. The x occlusion blades 32, 34 are arranged in a first plane 40, and the y occlusion blades 36, 38 are arranged in a second plane 42.

[0083] Each of the masking blades 32, 34, 36, 38 defines an edge of a rectangular field region 44 in the plane of the patterning device MA that can receive radiation. In practice, the illumination system IL may only illuminate a part of the rectangular field region 44. As Figure 5 shown, the illumination system IL may be arranged to illuminate a curved slit region 46, which may be part of the rectangular field region 44 (depending on the position of the y masking blades 36, 38). Each blade can be moved independently between a retracted position, in which the blade is not set in the path of the radiation beam, and an inserted position, in which the blade at least partially blocks the radiation beam projected by the illumination system IL onto the patterning device MA. By moving the masking blades 32, 34, 36, 38 into the path of the radiation beam, the radiation beam B can be truncated (in the x and / or y directions), and thus the extent of the field region 44 receiving the radiation beam B is limited.

[0084] The x direction corresponds to the non-scanning direction of the lithographic apparatus LA, and the y direction corresponds to the scanning direction of the lithographic apparatus LA. The patterning device MA can be moved through the field region 44 in the y direction (again as indicated by the arrow 26) in order to expose a larger area of the patterning device MA in a single dynamic scan exposure.

[0085] During the dynamic exposure of the target region of the substrate W, the target region is moved through the exposure region in the plane of the substrate W, which is the part of the substrate W onto which the exposure region 44 of the patterning device MA is imaged by the projection system PS. When the target region of the substrate W is moved into the exposure region, the first masking blades 36, 38 are moved so that only the target region receives radiation (i.e., no part of the substrate outside the target region is exposed). At the start of the scan exposure, one of the y masking blades 36, 38 is set in the path of the radiation beam B to act as a shutter so that no part of the substrate W receives radiation. At the end of the scan exposure, the other of the y masking blades 36, 38 is set in the path of the radiation beam B to act as a shutter so that no part of the substrate W receives radiation.

[0086] The rays of the radiation beam B are shown adjacent to each of the masking blades 32, 34, 36, 38. It should be understood that the radiation is irradiated at each point in the slit region 46 over a certain angular range. For example, each point in the slit region 46 can receive conical radiation. The rays of the radiation beam B being shown adjacent to each of the masking blades 32, 34, 36, 38 indicates that the radiation received by the patterning device MA has a uniform direction. From Figure 4A and 4BIt can be seen that, in this embodiment, when projected onto the x-z plane, the radiation is typically incident on the patterning device MA at normal incidence, while when projected onto the y-z plane, the radiation is typically incident on the patterning device MA at an angle of 48°.

[0087] The lithographic apparatus LA further includes a gas nozzle 50 which is arranged to direct an air flow 52 adjacent to the support structure MT. Specifically, the air flow 52 provided adjacent to the support structure MT by the gas nozzle 50 is substantially parallel to the surface of the patterning device MA and can be referred to as a cross-flow. The gas nozzle 50 is typically arranged in the same plane (the first plane 40) as the x-occlusion blades 32, 34. The gas nozzle is directed in the scan direction such that the air flow 52 is substantially parallel to the scan direction and flows between the x-occlusion blades 32, 34. The gas nozzle 50 can be considered to form part of a gas supply module operable to provide an air flow adjacent to the support structure MT.

[0088] Figure 5 A plan view is shown of the y-occlusion blades 36, 38 in the second plane 42 when viewed in the positive z direction (i.e., Figure 4B the upward direction in Figure 5 ). The positions of the x-occlusion blades 32, 34 and the gas nozzle (which are arranged in the first plane 40) are shown in dashed lines. In Figure 5 four occlusion blades 32, 34, 36, 38 are arranged so as to define a substantially rectangular field region 44, and a slit region 46 is arranged within the substantially rectangular field region 44. This can be the normal configuration of the four occlusion blades 32, 34, 36, 38 during the exposure of the central portion of the target region (e.g., a die on a substrate W). As described above, each of the x-occlusion blades 32, 34 is operable to move in the x direction, and each of the y-occlusion blades 36, 38 is operable to move in the y direction, thereby controlling the size of the field region 44. The y-occlusion blades 36, 38 are configured such that the y-occlusion blades 36, 38 can be actuated from the same side of the field region 44. To achieve this, the y-occlusion blades 36, 38 are shaped such that (although they are substantially arranged in the same plane 42) each of the y-occlusion blades 36, 38 is provided with one or more support portions extending in the same direction ( Figure 5 the negative y direction in

[0089] The occlusion blades 32, 34, 36, 38 and the gas nozzle 50 can be mounted on a common occlusion blade assembly support (not shown). It should be understood that the occlusion blades 32, 34, 36, 38 can be movably mounted on such a support such that they can move relative to the support. The gas nozzle can be statically mounted on such a support.

[0090] It may therefore be desirable to prevent the particles from contacting the patterning device MA, as this may lead to imaging errors in the image formed on the substrate W.

[0091] Embodiments of the present invention relate to an apparatus comprising a bias module for controlling the electric potential of a patterning device MA when supported by a support structure MT. Reference is now made to Figure 6A and 6B for discussion. The bias module includes a first electrode 54, a second electrode 56, and a power supply 58.

[0092] As can be best shown from Figure 6B each of the first electrode 54 and the second electrode 56 is spaced apart from and faces the support structure MT so as to at least partially overlap the support structure MT and the patterning device MA supported by the support structure MT. In Figure 6A a plan view of the support structure MT and the patterning device MA is shown, with the positions of the electrodes represented by dashed lines.

[0093] The power supply 58 is electrically connected to each of the first electrode 54 and the second electrode 56, as represented by lines 60, 62 respectively. The power supply 58 is operable to control the voltage of each of the first electrode 54 and the second electrode 56. Specifically, the power supply 56 is arranged to hold the first electrode 54 at a first positive voltage and the second electrode 56 at a second negative voltage.

[0094] The first positive voltage and the second negative voltage are set such that the voltage of the patterning device is negative.

[0095] The second electrode 56 (which is held at a negative voltage by the power supply) is arranged such that it at least partially overlaps the non-image forming portion 22 of the patterning device MA and does not overlap the image forming portion 20 of the patterning device MA.

[0096] It is particularly advantageous to combine such a bias module with a gas supply module (which may include, for example, the gas nozzle 50 described above), which will now be discussed. The bias module, the gas supply module (which may include, for example, the gas nozzle 50 described above), and the support structure can be considered to form a patterning device conditioning system (for example, for a lithographic apparatus LA).

[0097] Advantageously, the gas flow 52 from the gas nozzle 50 can be used to reduce the chance of such particles coming into contact with the patterning device MA, since these particles can be entrained in the gas flow 52 and transported away from the patterning device MA. However, in use, when the patterning device MA is exposed to the radiation beam B, the radiation can cause the gas 52 to form a plasma. As these particles move through the plasma, the particles tend to become negatively charged (since electrons in the plasma have a higher mobility than ions in the plasma). Additionally, in use, when the patterning device MA is exposed to radiation, the patterning device MA can become slightly positively charged due to the photoelectric effect. Thus, there may be a biasing force acting on these particles towards the patterning device MA, which is undesirable.

[0098] In a simple manner, a simple arrangement can be considered where a single biasing electrode is provided facing the patterning device MA and having, for example, a positive bias voltage, so as to attract the negatively charged particles towards the single biasing electrode and away from the patterning device MA. However, due to the presence of the plasma, in such an arrangement, the plasma will provide a conductive connection between the single biasing electrode and the patterning device MA. Thus, the floating patterning device MA will be pulled to the same electric potential as the single biasing electrode, and there will be no biasing field acting on the negatively charged particles.

[0099] Instead, the biasing module described above with reference to Figure 6A and 6B uses two biasing electrodes 54, 56. The first electrode 54 and the second electrode 56 are both capacitively coupled to the patterning device MA supported by the support structure MT. The first electrode 54 effectively pushes the voltage of the patterning device MA towards a first positive voltage, and the second electrode 56 effectively pushes the voltage of the patterning device MA towards a second negative voltage. This arrangement causes the patterning device MA to tend to have an intermediate voltage between the first positive voltage and the second negative voltage. The intermediate voltage can be considered as a weighted average of the first voltage and the second voltage, and the weighting can be determined by the capacitive coupling of the two electrodes 54, 56 to the patterning device MA. It should be understood that the capacitive coupling of each of the electrodes 54, 56 to the patterning device MA depends on the area of overlap of the electrodes 54, 56 with the patterning device MA and the spacing between the electrodes 54, 56 and the patterning device MA (as well as the dielectric constant of the medium provided between the electrodes 54, 56 and the patterning device MA). It should be understood that by appropriately selecting these parameters as well as the first voltage and the second voltage, it can be ensured that the voltage of the patterning device MA (also referred to as the intermediate voltage) is negative.

[0100] It should be understood that a positive surface charge density will be induced on the surface of the first electrode 54 (maintained at a first positive voltage), and a substantially equal and opposite negative surface charge density will be induced on the portion of the patterning device MA that overlaps with the first electrode 54. Therefore, any negative charges (such as negative charges entrained in the air flow) disposed between the first electrode 54 and the patterning device MA will tend to be biased towards the first electrode 54 and away from the patterning device MA. Since this keeps these particles away from the patterning device MA, it is advantageous.

[0101] Similarly, it should be understood that a negative surface charge density will be induced on the surface of the second electrode 56 (maintained at a second negative voltage), and a substantially equal and opposite positive surface charge density will be induced on the portion of the patterning device MA that overlaps with the second electrode 56. Therefore, any negative charges (such as negative charges entrained in the air flow) disposed between the second electrode 56 and the patterning device MA will tend to be biased towards the patterning device MA and away from the second electrode 56. However, the second electrode 56 is arranged such that it overlaps with the non-image forming portion 22 of the patterning device MA. Therefore, although these particles are pushed towards the patterning device MA, these particles are pushed towards the non-image forming portion 22 of the patterning device MA and thus do not affect the image formed on the substrate W.

[0102] Since the patterning device MA is maintained at a negative intermediate voltage, any negative charges (such as negative charges entrained in the air flow) adjacent to the patterning device MA that are not between the first electrode 54 and the patterning device MA or between the second electrode 56 and the patterning device MA will also tend to be biased away from the patterning device MA (assuming that the distance of these negative charges from the region of the patterning device MA that overlaps with the second electrode 56 having a negative charge density is far enough).

[0103] Therefore, since the gas supply module can provide an air flow 52 that can act to transport particles away from the patterning device MA, the above-described patterning device adjustment system is advantageous. At the same time, the bias module is arranged to generally bias negatively charged particles entrained in the air flow 52 away from all portions of the patterning device MA except for the non-image forming portion 22 of the patterning device MA.

[0104] The power supply 58 can be configured such that the first voltage (positive voltage) and the second voltage (negative voltage) result in a voltage amplitude of the patterning device MA being less than 50V. For example, the applied voltage can be such that the voltage of the patterning device MA is less than 20V, for example, on the order of 10V.

[0105] Maintaining the voltage of the pattern forming device MA at a relatively small and negative voltage can beneficially deflect the negatively charged particles away from the image forming portion 20 of the pattern forming device MA, while reducing the current level through the (relatively thin) conductive film on the pattern forming device MA. Advantageously, this can reduce the heating of the pattern forming device MA and / or damage to the pattern forming device MA. Additionally, once the voltage is removed from the first and second electrodes, the bias voltage that has been induced on the pattern forming device MA can be retained. By maintaining this voltage at a lower level (e.g., below 50 V), the likelihood of this voltage generating an arc or short - circuiting with other metal components is reduced.

[0106] It should be understood that the first electrode 54 and the second electrode 56 (shown rather schematically in Figure 6A and 6B can be disposed at any convenient location, provided that the second electrode 56 (which has a negative charge density) does not overlap with the image forming portion 20 of the pattern forming device. Either the first electrode or the second electrode can be provided by a plurality of electrodes. The first electrode and the second electrode can be disposed in substantially the same plane or in different planes at different distances from the pattern forming device MA (as shown in Figure 6A and 6B ).

[0107] It should be understood that for embodiments that include a scanning module and in which the support structure MT and the pattern forming device MA move in a scanning direction during use, the second electrode 56 can be arranged such that it always overlaps with the non - image forming portion 22 of the pattern forming device MA throughout its entire position range between the first end position and the second end position, without overlapping with the image forming portion 20 of the pattern forming device MA. That is, the second electrode can be arranged such that when the support structure MT is disposed at the first end position, the second end position, or any position between the first end position and the second end position, the second electrode at least partially overlaps with the non - image forming portion 22 of the pattern forming device MA and does not overlap with the image forming portion 20 of the pattern forming device MA. In practice, this can be achieved using a plurality of second electrodes. For example, the voltages of these multiple second electrodes can be controlled according to the position of the pattern forming device MA.

[0108] In some embodiments, the second electrode is disposed on one or both of the two x - shading blades 32, 34. Advantageously, the x - shading blades 32, 34 overlap with the pattern forming device MA throughout their entire position range between the first end position and the second end position, specifically with the non - image forming portion 22 of the pattern forming device MA.

[0109] Optionally, the first electrode 54 may be arranged such that the first electrode 54 at least partially overlaps with the image forming part 20 of the patterning device MA. For example, such an arrangement may be used for embodiments including a scanning module operable to move the support structure MT. As described above, for such a scanning arrangement, at least a part of the image forming part 20 of the patterning device MA is always unable to receive the radiation beam B. The first electrode 54 may be arranged such that at least a part of the position range between the first end position and the second end position, the first electrode 54 at least partially overlaps with the image forming part 20 of the patterning device MA. The first electrode 54 may be arranged such that within the entire position range between the first end position and the second end position, the first electrode 54 at least partially overlaps with the image forming part 20 of the patterning device MA. In practice, this may be achieved using a plurality of first electrodes. For example, the voltages of these plurality of first electrodes may be controlled according to the position of the patterning device MA.

[0110] In some embodiments, the first electrode may include one or more electrodes, and the one or more electrodes are arranged on any component that overlaps with the image forming part 20 of the patterning device MA for at least a part of the range of the scanning positions between the first end position and the second end position. For example, the first electrode may be arranged on the y-blocking blades 38, 38 and / or the gas nozzle 50.

[0111] Generally, for embodiments including a scanning module operable to move the support structure MT, as described above, the first electrode 54 may include one or more electrodes arranged to overlap within the extended first part region 28 of the support structure MT (see Figure 3A and 3B ), and the second electrode 56 may include one or more electrodes arranged to overlap within the extended non-critical regions 30a, 30b of the support structure MT (see Figure 3A and 3B ).

[0112] In some embodiments, the patterning device MA may be provided with a pellicle assembly. Such a pellicle assembly may include a relatively thin diaphragm tensioned over a support frame. The pellicle assembly is disposed above the patterning device MA to cover the image forming portion 20. For example, the frame may overlap the non-image forming portion 22 of the patterning device MA, and the diaphragm may overlap the image forming portion 20 of the patterning device MA. For such embodiments, the patterning device adjustment system may be modified to provide the following scheme: the image forming portion 20 of the patterning device MA has a negative bias voltage relative to the pellicle, thereby generating an electric driving force acting on the particles from the patterning device MA towards the pellicle. It should be understood that for embodiments using a pellicle, only the particles present between the pellicle and the patterning device have imaging problems (particles outside this region cannot enter the patterning device MA due to the pellicle).

[0113] This can be achieved by placing a negative bias voltage counter electrode facing the conductive surface of the patterning device MA outside the pellicle region (for example, in a region extending in the non-scanning direction), and by placing a positive bias voltage counter electrode facing the pellicle inside the pellicle region (for example, in a region extending along the scanning direction). That is, there is no significant change in the positioning or biasing of the electrodes of the patterning device adjustment system to be adapted for use with a pellicle. The pellicle effectively provides an effective first electrode that is held at a positive bias voltage by the actual first electrode. Advantageously, the effective first electrode formed by the pellicle can cover the entire image forming portion 20 of the patterning device MA over the entire range of the scanning positions (since the pellicle moves together with the patterning device MA). However, it should be understood that the overlap between the actual electrode (which applies a voltage to the pellicle by capacitive coupling) and the pellicle may vary within the scanning position range of the patterning device MA.

[0114] Although specific reference may be made herein to the use of a lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications. Other possible applications include the manufacture of integrated optical systems, guiding and detecting patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), pellicle magnetic heads, and the like.

[0115] Although embodiments of the present invention may be specifically referred to herein in the context of a lithographic apparatus, embodiments of the present invention may be used in other apparatuses. Embodiments of the present invention may form part of a mask inspection apparatus, a metrology apparatus, or any apparatus for measuring or processing an object such as a wafer (or other substrate) or a mask (or other patterning device). These apparatuses may generally be referred to as lithographic tools. Such lithographic tools may use vacuum conditions or ambient (non-vacuum) conditions.

[0116] Although the above may have specifically referred to the use of embodiments of the present invention in the context of optical lithography, it should be understood that the present invention is not limited to optical lithography and, where the context permits, the present invention may be used in other applications such as, for example, imprint lithography.

[0117] Where the context permits, embodiments of the present invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the present invention may also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read-only memory (ROM); random access memory (RAM); magnetic disk 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 the like. In addition, firmware, software, programs, and / or instructions may be described herein as performing particular actions. However, it should be understood that these descriptions are for convenience only and that these actions are actually generated by a computing device, processor, controller, or other device executing the firmware, software, programs, instructions, etc., and may cause actuators or other devices to interact with the actual environment when performing these actions.

[0118] Although specific embodiments of the present invention have been described above, it should be understood that the present invention may be practiced in a manner different from that described. The above description is intended to be illustrative, not restrictive. Thus, it will be apparent to those skilled in the art that the described present invention may be modified without departing from the scope of the claims set forth below.

[0119] Item

[0120] Article 1. A pattern forming device adjustment system for a lithographic apparatus, the pattern forming device adjustment system comprising: a support structure for supporting a pattern forming device, the support structure including a first portion for supporting an image forming portion of the pattern forming device and a second portion for supporting a non-image forming portion of the pattern forming device; a gas supply module capable of operating to provide an air flow adjacent to the support structure; and a bias module for controlling the electric potential of the pattern forming device when the pattern forming device is supported by the support structure, the bias module including a first electrode, a second electrode, and a power supply; wherein each of the first electrode and the second electrode is spaced apart from the support structure and faces the support structure to at least partially overlap with the support structure; wherein the power supply is arranged to hold the first electrode at a first positive voltage and the second electrode at a second negative voltage; wherein the second electrode is arranged such that the second electrode at least partially overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

[0121] Article 2. The pattern forming device adjustment system according to Article 1, wherein the first positive voltage and the second negative voltage are such that the voltage of the pattern forming device is negative.

[0122] Article 3. The pattern forming device adjustment system according to Article 1 or Article 2, further comprising a scanning module capable of operating to move the support structure in a scanning direction between at least a first end position and a second end position.

[0123] Article 4. The pattern forming device adjustment system according to any one of the preceding articles, wherein the second electrode is arranged such that when the support structure is disposed at the first end position, the second end position, or any position between the first end position and the second end position, the second electrode at least partially overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

[0124] Article 5. The pattern forming device adjustment system according to any one of the preceding articles, wherein the first electrode is arranged such that the first electrode at least partially overlaps with the first portion of the support structure.

[0125] Article 6. The pattern forming device adjustment system according to any one of the preceding articles, wherein the first electrode includes a plurality of first electrode elements.

[0126] Clause 7. The pattern forming apparatus adjustment system according to Clause 6 which is directly or indirectly subordinate to Clause 3, wherein the first electrode element is arranged such that, for any position within the range of positions between the first end position and the second end position, at least one of the first electrode elements overlaps at least partially with the support structure.

[0127] Clause 8. The pattern forming apparatus adjustment system according to Clause 7, wherein at least one of the first electrode elements overlaps at least partially with a first portion of the support structure.

[0128] Clause 9. The pattern forming apparatus adjustment system according to Clause 6 which is directly or indirectly subordinate to Clause 3, wherein the power supply is arranged to control the voltage of each of the first electrode elements according to the position of the support structure.

[0129] Clause 10. The pattern forming apparatus adjustment system according to any one of the preceding clauses, wherein the second electrode includes a plurality of second electrode elements, and each of the second electrode elements is arranged such that it overlaps at least partially with a second portion of the support structure and does not overlap with the first portion of the support structure.

[0130] Clause 11. The pattern forming apparatus adjustment system according to Clause 10 which is directly or indirectly subordinate to Clause 2, wherein the second electrode includes two second electrode elements, and each of the second electrode elements extends in a non-scanning direction perpendicular to the scanning direction.

[0131] Clause 12. The pattern forming apparatus adjustment system according to Clause 10 or Clause 11 which is directly or indirectly subordinate to Clause 3, wherein the power supply is arranged to control the voltage of each of the second electrode elements depending on the position of the support structure.

[0132] Clause 13. The pattern forming apparatus adjustment system according to any one of the preceding clauses, wherein the first positive voltage and the second negative voltage are such that the voltage amplitude of the pattern forming apparatus is less than 50V.

[0133] Clause 14. The pattern forming apparatus adjustment system according to any one of the preceding clauses, wherein one or more of the first electrode and the second electrode are provided on a pattern forming apparatus masking blade, and an edge of the pattern forming apparatus masking blade defines a part of the outer periphery of the field region on the pattern forming apparatus.

[0134] Clause 15. The pattern forming apparatus adjustment system according to any one of the preceding clauses, wherein one or more of the first electrode and the second electrode are provided on a part of the gas supply module.

[0135] Clause 16. A component, comprising: a patterning device adjustment system according to any one of the foregoing clauses; and a patterning device supported by a support structure.

[0136] Clause 17. The component according to clause 16, wherein the patterning device is provided with a pellicle.

[0137] Clause 18. A lithographic apparatus, comprising: an illumination system operable to output a radiation beam; a patterning device adjustment system according to any one of clauses 1-15, wherein the radiation beam output by the illumination system is directed to a support structure such that a patterning device supported by the support structure can impart a pattern in a cross-section of the radiation beam, thereby forming a patterned radiation beam; a substrate table for supporting a substrate; and a projection system for projecting the patterned radiation beam onto a target area of the substrate to form an image on the substrate.

[0138] Clause 19. A method for adjusting a patterning device in a lithographic apparatus, the method comprising: supporting the patterning device; providing an air flow adjacent to the patterning device; providing a first electrode and a second electrode, each of the first electrode and the second electrode being spaced apart from the patterning device and facing the patterning device to at least partially overlap with the patterning device, wherein the second electrode is arranged such that the second electrode at least partially overlaps with a non-image-forming part of the patterning device and does not overlap with an image-forming part of the patterning device; and maintaining the first electrode at a first positive voltage and the second electrode at a second negative voltage such that the voltage of the patterning device is negative.

[0139] Clause 20. A method for adjusting a patterning device having a pellicle assembly in a lithographic apparatus, the method comprising: supporting the patterning device; providing an air flow adjacent to the patterning device; providing a first electrode and a second electrode, each of the first electrode and the second electrode being spaced apart from the patterning device and facing the patterning device to at least partially overlap with the patterning device, wherein the second electrode is arranged such that the second electrode at least partially overlaps with a part of the patterning device and does not overlap with the pellicle assembly, and wherein the first electrode is arranged such that the first electrode at least partially overlaps with the pellicle assembly; and maintaining the first electrode at a first positive voltage and the second electrode at a second negative voltage such that the voltage of the patterning device is negative and the voltage of the pellicle is positive.

[0140] Item 21. The method according to Item 19 or Item 20 further includes moving the support structure in a scanning direction between at least a first end position and a second end position.

[0141] Item 22. The method according to Item 21, wherein the power supply controls the first positive voltage and / or the second negative voltage based on the position of the pattern forming device.

[0142] Item 23. The method according to any one of Items 19 to 22, wherein at least a part of the method is performed by using a pattern forming device adjustment system according to any one of Items 1 to 15.

Claims

1. A pattern forming apparatus adjustment system for a lithographic apparatus, the pattern forming apparatus adjustment system comprising: A support structure for supporting a pattern forming apparatus, the support structure comprising: a first portion for supporting an image forming portion of the pattern forming apparatus, and a second portion for supporting a non-image forming portion of the pattern forming apparatus; A gas supply module operable to provide an air flow adjacent to the support structure; and A bias module for controlling the electric potential of the pattern forming apparatus when the pattern forming apparatus is supported by the support structure, the bias module comprising a first electrode, a second electrode and a power supply; Wherein each of the first electrode and the second electrode is spaced apart from the support structure and faces the support structure to at least partially overlap with the support structure; Wherein the power supply is arranged to hold the first electrode at a first positive voltage and the second electrode at a second negative voltage; Wherein the second electrode is arranged such that the second electrode at least partially overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

2. The pattern forming apparatus adjusting system according to claim 1, wherein, The first positive voltage and the second negative voltage cause the voltage of the pattern forming apparatus to be negative.

3. The pattern forming apparatus adjustment system according to claim 1 or 2, further comprising a scanning module operable to move the support structure in a scanning direction between at least a first end position and a second end position.

4. The pattern forming apparatus adjustment system according to claim 3, wherein, The second electrode is arranged such that when the support structure is disposed at the first end position, the second end position, or any position between the first end position and the second end position, the second electrode at least partially overlaps with the second portion of the support structure and does not overlap with the first portion of the support structure.

5. The pattern forming apparatus adjustment system according to claim 1 or 2, wherein, The first electrode is arranged such that the first electrode at least partially overlaps with the first portion of the support structure.

6. The pattern forming apparatus adjustment system according to claim 1 or 2, wherein, The first electrode comprises a plurality of first electrode elements.

7. The pattern forming apparatus adjustment system according to claim 6, further comprising a scanning module operable to move the support structure in a scanning direction between at least a first end position and a second end position; Among them, The first electrode elements are arranged such that for any position within the position range between the first end position and the second end position, at least one of the first electrode elements at least partially overlaps with the support structure.

8. The pattern forming apparatus adjustment system according to claim 7, wherein at least one of the first electrode elements at least partially overlaps with the first portion of the support structure.

9. The pattern forming apparatus adjustment system according to claim 6, further comprising a scanning module operable to move the support structure in a scanning direction between at least a first end position and a second end position; Wherein the power supply is arranged to control the voltage of each of the first electrode elements according to the position of the support structure.

10. The pattern forming apparatus adjusting system according to claim 2, wherein the second electrode includes a plurality of second electrode elements, and each of the second electrode elements is arranged such that it at least partially overlaps with the second part of the support structure and does not overlap with the first part of the support structure.

11. The pattern forming apparatus adjusting system according to claim 10, further comprising a scanning module operable to move the support structure in a scanning direction between at least a first end position and a second end position; wherein the second electrode includes two second electrode elements, and each of the second electrode elements extends in a non-scanning direction perpendicular to the scanning direction.

12. The pattern forming apparatus adjusting system according to claim 10, further comprising a scanning module operable to move the support structure in a scanning direction between at least a first end position and a second end position; Among them, The power supply is arranged to control the voltage of each of the second electrode elements according to the position of the support structure.

13. The pattern forming apparatus adjustment system according to claim 1 or 2, wherein, The first positive voltage and the second negative voltage make the voltage amplitude of the pattern forming apparatus less than 50V.

14. A method for adjusting a pattern forming apparatus in a lithographic apparatus, the method comprising: Supporting the pattern forming apparatus; Providing an air flow adjacent to the pattern forming apparatus; Providing a first electrode and a second electrode, each of the first electrode and the second electrode being spaced apart from and facing the pattern forming apparatus to at least partially overlap with the pattern forming apparatus, wherein the second electrode is arranged such that the second electrode at least partially overlaps with a non-image forming part of the pattern forming apparatus and does not overlap with an image forming part of the pattern forming apparatus; And, Maintaining the first electrode at a first positive voltage and the second electrode at a second negative voltage such that the voltage of the pattern forming apparatus is negative.

15. A method for adjusting a pattern forming apparatus having a pellicle assembly in a lithographic apparatus, the method comprising: Supporting the pattern forming apparatus; Providing an air flow adjacent to the pattern forming apparatus; Providing a first electrode and a second electrode, each of the first electrode and the second electrode being spaced apart from and facing the pattern forming apparatus to at least partially overlap with the pattern forming apparatus, wherein the second electrode is arranged such that the second electrode at least partially overlaps with a part of the pattern forming apparatus and does not overlap with the pellicle assembly, and wherein the first electrode is arranged such that the first electrode at least partially overlaps with the pellicle assembly; And, Maintaining the first electrode at a first positive voltage and the second electrode at a second negative voltage such that the voltage of the pattern forming apparatus is negative and the voltage of the pellicle is positive.

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