Cleaning apparatus, photolithography equipment, methods for removing water or other contaminants, and device manufacturing methods

Abstract

A cleaning device (10) for a lithography apparatus, the cleaning device comprising: a radiation source (2) configured to supply purifying radiation (8) capable of removing water or other contaminants from the surface of optical components (IL; PS) or other components of the lithography system; wherein the cleaning device is configured to be held by a clamp (7) that holds a pattern forming apparatus during an exposure process performed by the lithography apparatus.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to European application 19200715.1, filed on 1 October 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to cleaning devices, photolithography equipment, methods for removing water or other contaminants, and methods for manufacturing such devices. Background Technology

[0004] A photolithography apparatus is a machine that applies a desired pattern onto a substrate (typically a target portion of the substrate). Photolithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In this instance, a patterning apparatus (alternatively referred to as a mask or photomask) can be used to generate a circuit pattern to be formed on a single layer of the IC. This pattern can then be transferred to a target portion (e.g., comprising a portion of a die, one or more dies) on a substrate (e.g., a silicon wafer). Typically, the transfer of the pattern is performed by imaging onto a radiation-sensitive material (resist) layer disposed on the substrate. Typically, a single substrate will contain a network of adjacent target portions patterned sequentially.

[0005] Photolithography is widely recognized as one of the key steps in manufacturing integrated circuits and other devices and / or structures. However, as the size of features created using photolithography becomes smaller, it is becoming an even more critical factor in the manufacture of micro-ICs or other devices and / or structures.

[0006] The theoretical estimate of the pattern printing limit can be given by the Rayleigh resolution criterion, as shown in equation (1):

[0007]

[0008] Where λ is the wavelength of the radiation used, NA is the numerical aperture of the projection system used to print the pattern, k1 is a process-dependent adjustment factor (also known as the Rayleigh constant), and CD is the feature size (or critical size) of the printed feature. From equation (1), it can be seen that the minimum printable size of the feature can be reduced in three ways: by shortening the exposure wavelength λ; by increasing the numerical aperture NA; or by decreasing the value of k1.

[0009] To shorten the exposure wavelength and thus reduce the minimum printable size, the use of extreme ultraviolet (EUV) radiation sources has been proposed. EUV radiation is electromagnetic radiation with wavelengths in the range of 10 nm to 20 nm, for example, in the range of 13 nm to 14 nm. It has been further proposed to use EUV radiation with wavelengths less than 10 nm, for example, in the range of 5 nm to 10 nm (such as 6.7 nm or 6.8 nm). This radiation is referred to as extreme ultraviolet radiation or soft X-ray radiation. Possible sources include, for example, laser-generated plasma sources, discharge plasma sources, or sources based on synchrotron radiation provided by electron storage rings.

[0010] Plasma can be used to generate EUV radiation. A radiation system for generating EUV radiation may include a laser for exciting fuel to provide the plasma, and a source collector module for containing the plasma. The plasma can be generated, for example, by directing a laser beam to fuel, such as particles of a suitable material (e.g., tin), or a stream of a suitable gas or vapor (e.g., Xe gas or Li vapor). The resulting plasma emits output radiation, such as EUV radiation, collected using a radiation collector. The radiation collector may be a mirror-normal-incident radiation collector that receives the radiation and focuses it into a beam. The source collector module may include an enclosure structure or chamber arranged to provide a vacuum environment to support the plasma. Such a radiation system is typically referred to as a laser-generated plasma (LPP) source.

[0011] The photolithography apparatus includes, for example, optical elements for generating the radiation beam and projecting the radiation beam onto the substrate. Following maintenance intervention, water and hydrocarbon contaminants may deposit on the optical elements. Furthermore, the transmission and reflection properties of the optical elements may deteriorate over time due to water and possible contaminant particles on them. The optical elements can be cleaned using a scanner.

[0012] It is desirable to provide a cleaning device that can clean the optical elements more effectively and / or at a lower cost. Summary of the Invention

[0013] According to one aspect of the present invention, a cleaning apparatus for a photolithography apparatus is provided, the cleaning apparatus comprising: a radiation source configured to supply purifying radiation or decontamination radiation capable of removing water or other contaminants from the surface of optical components or other components of the photolithography apparatus; wherein the cleaning apparatus is configured to be held by a clamp holding a pattern forming apparatus during an exposure process performed by the photolithography apparatus.

[0014] According to one aspect of the present invention, a photolithography apparatus is provided, comprising: a radiation system configured to provide a projection beam of radiation; a support structure configured to support a pattern forming apparatus for patterning the projection beam according to a desired pattern; a substrate stage configured to hold a substrate; a projection system configured to project the patterned beam onto a target portion of the substrate; and a cleaning apparatus as described above, wherein the support structure is configured to support the cleaning apparatus.

[0015] According to one aspect of the present invention, a method for removing water or other contaminants from the surface of an optical component or other component of a photolithography apparatus is provided, the method comprising the steps of: clamping a cleaning device onto a support structure configured to support a pattern forming apparatus for patterning a projection beam according to a desired pattern; and supplying purifying radiation from the cleaning device to remove water or other contaminants from the surface of the optical component or other component of the photolithography apparatus.

[0016] According to one aspect of the present invention, a method for manufacturing a device is provided, comprising the steps of: removing water or other contaminants by irradiation from a cleaning device using radiation capable of removing water or other contaminants from the surface of optical components or other components of a photolithography device; replacing the cleaning device with a patterning device; providing a substrate at least partially covered by a radiation-sensitive material layer; providing a radiation projection beam using a radiation system; patterning the projection beam in a cross-section of the projection beam using the patterning device; and projecting the patterned radiation beam onto a target portion of the radiation-sensitive material layer. Attached Figure Description

[0017] Embodiments of the invention will now be described by way of example only, with reference to the accompanying schematic drawings, in which corresponding reference numerals indicate corresponding parts or components, and in the drawings:

[0018] Figure 1 A photolithography apparatus according to an embodiment of the present invention is described;

[0019] Figure 2 This is a more detailed view of the lithography equipment;

[0020] Figure 3 yes Figure 1 and Figure 2 A more detailed view of the device's source collector module SO; and

[0021] Figure 4 This is a schematic diagram of a cleaning device in an EUV lithography apparatus according to an embodiment of the present invention.

[0022] The features and advantages of the invention will become apparent from the specific embodiments described below, when taken in conjunction with the accompanying drawings, in which similar reference numerals identify corresponding elements throughout the drawings. In the drawings, similar reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. Detailed Implementation

[0023] Figure 1 A lithography apparatus 100 including a source collector module SO is schematically illustrated according to an embodiment of the present invention. The apparatus includes:

[0024] - Irradiation system (irradiator) IL, the irradiation system (irradiator) IL being configured to modulate the radiation beam B (e.g., EUV radiation);

[0025] - A support structure (e.g., a mask stage) MT, which is configured to support a pattern forming apparatus (e.g., a mask or a mask plate) MA and is connected to a first locator PM, which is configured to accurately position the pattern forming apparatus.

[0026] - A substrate stage (e.g., a wafer stage) WT, the substrate stage being configured to hold a substrate (e.g., a wafer coated with resist) W and being connected to a second positioner PW, the second positioner PW being configured to accurately position the substrate; and

[0027] - A projection system (e.g., a reflective projection system) PS, which is configured to project a pattern given by a patterning device MA to the radiation beam PB onto a target portion C (e.g., comprising one or more dies) of the substrate W.

[0028] The irradiation system may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof, to guide, shape, or control radiation.

[0029] The support structure MT holds the patterning apparatus in a manner dependent on the orientation of the patterning apparatus, the design of the lithography equipment, and other conditions (such as whether the patterning apparatus is held in a vacuum environment). The support structure can use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning apparatus. The support structure can be a frame or a platform, and for example, it can be fixed or movable as needed. The support structure ensures that the patterning apparatus (e.g., relative to the projection system) is positioned as desired.

[0030] The term "patterning apparatus" should be interpreted broadly to refer to any apparatus that can be used to impart a pattern to a radiation beam in a cross-section to generate a pattern in a target portion of the substrate. The pattern imparted to the radiation beam may correspond to a specific functional layer in a device (such as an integrated circuit) generated in the target portion.

[0031] The pattern forming apparatus can be transmissive or reflective. Examples of pattern forming apparatus include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in photolithography and include mask types such as binary masks, alternating phase-shift masks, attenuating phase-shift masks, and various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted to reflect incident radiation beams in different directions. The tilted mirrors impart a pattern to the radiation beam reflected by the mirror matrix.

[0032] The projection system (such as the illumination system) may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof, as appropriate for the exposure radiation used or other factors (such as the use of a vacuum). It may be desirable to use a vacuum for EUV radiation because other gases may absorb excessive radiation. Therefore, a vacuum environment can be provided throughout the beam path by means of vacuum walls and a vacuum pump.

[0033] As described herein, the device is reflective (i.e., utilizing a reflective mask).

[0034] The lithography apparatus may be of the type having two (dual-platform) or more substrate stages (and / or two or more mask stages). In such a “multi-platform” machine, additional stages can be used in parallel, or one or more other stages can be used for exposure while preparatory steps are performed on one or more stages.

[0035] refer to Figure 1 The irradiator IL receives an extreme ultraviolet (EUV) radiation beam from the source collector module SO. Methods for generating EUV light include, but are not limited to, converting a material into a plasma state having at least one element (e.g., xenon, lithium, or tin) possessing one or more emission lines in the EUV range. In such a method, often referred to as laser-generated plasma (“LPP”), the desired plasma can be generated by irradiating a fuel, such as a droplet, stream, or cluster of material having the desired line-emitting element, with a laser beam. The source collector module SO may be an EUV radiation system including a laser for providing a laser beam to excite the fuel. Figure 1(Not shown in the image) Parts or components. The resulting plasma emission uses output radiation, such as EUV radiation, collected by a radiation collector disposed in the source. The laser and the source collector module can be separate entities, for example, when a CO2 laser is used to provide a laser beam for fuel excitation.

[0036] In this case, the laser is not considered to constitute part or component of the lithography apparatus, and the radiation beam is delivered from the laser to the source collector module by means of a beam delivery system including, for example, suitable directional mirrors and / or beam expanders. In other words, for example, when the source is a discharge-generated plasma EUV generator (often referred to as a DPP source), the source can be an integral part of the source collector module.

[0037] The irradiator IL may include adjusters for adjusting the angular intensity distribution of the radiation beam. Typically, at least the outer radial range and / or inner radial range (often referred to as outer and inner, respectively) of the intensity distribution in the pupil plane of the irradiator can be adjusted. Furthermore, the irradiator IL may include various other components, such as faceted field mirror assemblies and faceted pupil mirror assemblies. The irradiator can be used to adjust the radiation beam to have a desired uniformity and intensity distribution in its cross-section.

[0038] The radiation beam B is incident on the patterning apparatus (e.g., mask) MA, which is held on the support structure (e.g., mask stage) MT, and is patterned by the patterning apparatus. After being reflected from the patterning apparatus (e.g., mask) MA, the radiation beam B is passed through the projection system PS, which focuses the beam onto the target portion C of the substrate W. The substrate stage WT can be accurately moved, for example, to position different target portions C in the path of the radiation beam B, by means of the second locator PW and the substrate sensor PS2 (e.g., interferometer device, linear encoder, or capacitive sensor). Similarly, the first locator PM and another position sensor PS1 can be used to accurately position the patterning apparatus (e.g., mask) MA relative to the path of the radiation beam B. The patterning apparatus (e.g., mask) MA and the substrate W can be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2.

[0039] The described device can be used in at least one of the following modes:

[0040] 1. In step mode, the support structure (e.g., mask stage) MT and the substrate stage WT are held substantially stationary while the entire pattern to be applied to the radiation beam is projected onto the target portion C in one pass (i.e., single static exposure). The substrate stage WT is then shifted along the X and / or Y directions to allow exposure of different target portions C.

[0041] 2. In scanning mode, the support structure (e.g., mask stage) MT and the substrate stage WT are scanned synchronously, while the pattern to be applied to the radiation beam is projected onto the target portion C (i.e., single dynamic exposure). The velocity and direction of the substrate stage WT relative to the support structure (e.g., mask stage) MT can be determined by the (reduced) magnification and image inversion characteristics of the projection system PS.

[0042] 3. In another mode, the support structure (e.g., a mask stage) MT is held substantially stationary to hold the programmable patterning apparatus, and the substrate stage WT is moved or scanned while a pattern applied to the radiation beam is projected onto the target portion C. In this mode, a pulsed radiation source is typically used, and the programmable patterning apparatus is updated as needed after each movement of the substrate stage WT or between successive radiation pulses during scanning. This mode of operation can be readily applied to maskless lithography utilizing programmable patterning apparatuses (such as programmable mirror arrays of the type mentioned above).

[0043] Alternatively, the usage patterns described above or combinations and / or variations of completely different usage patterns can be adopted.

[0044] Figure 2 The device 100 is shown in more detail, comprising a source collector module SO, an irradiation system IL, and a projection system PS. The source collector module SO is constructed and arranged such that a vacuum environment can be maintained within the enclosure 220 of the source collector module SO. A plasma 210 emitting EUV radiation can be formed by generating a plasma source through a discharge. The EUV radiation can be generated by a gas or vapor, such as Xe gas, Li vapor, or Sn vapor, which produces a very hot plasma 210 to emit radiation in the EUV range of the electromagnetic spectrum. The very hot plasma 210 is generated, for example, by a discharge that causes at least partially ionized plasma. To efficiently generate radiation, Xe, Li, Sn vapor, or any other suitable gas or vapor, for example, at a partial pressure of 10 Pa, may be required. In an embodiment, excited tin (Sn) plasma is provided to generate EUV radiation.

[0045] Radiation emitted by thermal plasma 210 is transmitted from source chamber 211 to collector chamber 212 via an optional gas barrier or contaminant trap 230 (also referred to in some cases as a contaminant barrier or fin trap), which is positioned in or behind an opening in source chamber 211. Contaminant trap 230 may include a channel structure. Contaminant trap 230 may also include a gas barrier, or a combination of a gas barrier and a channel structure. Contaminant traps or contaminant barriers 230 further indicated herein include at least a channel structure, as known in the art.

[0046] Collector chamber 212 may include a radiation collector CO, which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation passing through the collector CO may be reflected off the grating spectral filter 240 to be focused onto a virtual source point IF. This virtual source point IF is often referred to as the intermediate focus, and the source collector module is arranged such that the intermediate focus IF is located at or near an opening 221 in the enclosure structure 220. The virtual source point IF is an image of the radiative emission plasma 210.

[0047] Subsequently, the radiation traverses the illumination system IL, which may include a faceted field mirror assembly 22 and a faceted pupil mirror assembly 24. The faceted field mirror assembly 22 and the faceted pupil mirror assembly 24 are arranged to provide a desired angular distribution of the radiation beam 21 at the patterning apparatus MA and to provide desired radiation intensity uniformity at the patterning apparatus MA. When the radiation beam 21 is reflected at the patterning apparatus MA, which is held by the support structure MT, a patterned beam 26 is formed, and the patterned beam 26 is imaged by the projection system PS via reflective elements 28 and 30 onto a substrate W held by a wafer platform or substrate stage WT.

[0048] The illumination optical unit IL and projection system PS can typically contain more components than shown. Depending on the type of photolithography equipment, a grating spectral filter 240 may optionally be present. Furthermore, more than... Figure 2 More mirrors are shown, for example, with Figure 2 Compared to the example shown, one to six additional reflective elements can exist in the projection system PS.

[0049] As an example only for collectors (or collector mirrors), such as Figure 2The illustrated collector optics CO is depicted as a nested collector with grazing incidence reflectors 253, 254, and 255. The grazing incidence reflectors 253, 254, and 255 are arranged symmetrically about the optical axis O, and this type of collector optics CO is preferably used in conjunction with a discharge-generated plasma source (commonly referred to as a DPP source).

[0050] Alternatively, the source collector module SO can be part of an LPP radiation system, such as Figure 3 As shown, the laser LA is arranged to deposit laser energy into a fuel such as xenon (Xe), tin (Sn), or lithium (Li), thereby generating a highly ionized plasma 210 with an electron temperature of tens of electron volts. High-energy radiation generated during the deexcitation and recombination of these ions is emitted from the plasma, collected by a near-normal (i.e., near-normal) collector optics CO, and focused onto an opening 221 in the enclosure structure 220.

[0051] The photolithography apparatus 100 includes optical elements such as lenses and mirrors. For example, the projection system PS may include a combination of lenses and mirrors. In an embodiment, the surface of the optical elements is coated. Over time, the transmission and / or reflection properties of the optical elements may deteriorate. In particular, transmission loss and / or reflection loss may increase. This deterioration is at least partially caused by oxidation of the surface of the coating.

[0052] The inventors have discovered that the oxidation is at least partially caused by water present on the optical surface. Water molecules can be deposited during the use of the photolithography apparatus 100. In a vacuum environment, these water molecules can remain on surfaces, for example, on the surfaces of optical components (such as mirrors or films), or on the surfaces of other components of the photolithography apparatus (such as the inner surface of the container or housing of the photolithography apparatus). EUV radiation incident on a surface containing water causes the water molecules to transform into hydrogen and oxygen free radicals. The oxygen free radicals cause oxidation of the optical coating.

[0053] Oxidation of the mirror is an irreversible and highly destructive process, resulting in a significant loss of reflectivity. Since replacing the mirror is extremely costly, this ultimately leads to the lithography equipment operating at a lower level of reflection, thus reducing productivity. The reduced lifespan of the mirror also results in another significant economic disadvantage.

[0054] In an embodiment, the photolithography apparatus 100 includes one or more transmission films. For example, a film referred to as a surface film can be used to prevent particles from reaching the pattern forming apparatus MA.

[0055] In one embodiment, the lithography apparatus 100 includes a dynamic gas lock. The dynamic gas lock is configured to prevent gas from flowing between different portions or segments of the lithography apparatus 100. The dynamic gas lock may include a hollow portion covered by a surface film (i.e., a transmission film) located in an intermediate space.

[0056] Water molecules may be present on the surface of the membrane (e.g., on the surface of a patterning apparatus or in a dynamic airlock). Water molecules may cause a decrease in the membrane's transmittance to EUV radiation. Water molecules may cause the membrane to sag or loosen. Water molecules may increase the likelihood of the membrane rupturing.

[0057] Figure 4 This is a schematic diagram of a cleaning device 10 for an EUV lithography apparatus 100. The cleaning device 10 is configured to clean surfaces within the lithography apparatus 100. For example, in one embodiment, the cleaning device 10 is configured to clean the surfaces of optical elements (or their coatings). In another embodiment, the cleaning device 10 is configured to clean the surfaces of one or more films used in the lithography apparatus 100.

[0058] like Figure 4 As shown, in one embodiment, the cleaning device 10 includes a radiation source 2. The radiation source 2 is configured to provide decontamination radiation, i.e., purification radiation 8. The type of the radiation source 2 is not particularly limited. In one embodiment, the radiation source 2 is a VCSEL. In an alternative embodiment, the radiation source 2 is an edge-emitting infrared diode.

[0059] The decontamination radiation 8 removes water or other contaminants adhering to the surfaces of optical components or other parts of the lithography apparatus. Water contaminates the optical components. In embodiments, the decontamination radiation 8 removes contaminants such as hydroxyl groups. Water molecules and hydroxyl groups can help other contaminants (including contaminant particles) adhere to the optical components (e.g., by capillary forces). These contaminant particles can be introduced into the system from an external source or can be generated within the lithography apparatus 100. For example, the contaminant particles may include debris and byproducts loosely sputtered from the substrate W due to the EUV radiation beam B. By removing water and / or hydroxyl groups from the optical components, contaminant particles are more easily removed, for example, by a rinsing process. By using the cleaning device 100, water accumulated on the optical elements can be removed before exposing the optics to EUV radiation. Embodiments of the invention are intended to reduce the likelihood of oxidation mechanisms (so that fewer water molecules can be broken down). Embodiments of the invention are intended to shorten EUV scanner stabilization time during and after scanner recovery.

[0060] In one embodiment, the purifying radiation 8 has a wavelength range of approximately 3 μm. However, other wavelengths (e.g., other infrared wavelengths) can be used. A suitable wavelength or wavelength range for the purifying radiation 8 is in the range of 2 μm to 300 mm. In one embodiment, the purifying radiation 8 has a wavelength in the range of approximately 100 μm to approximately 300 mm (microwave radiation). In another embodiment, the purifying radiation 8 has a wavelength in the range of approximately 2 μm to approximately 30 μm (infrared radiation). The wavelength of the purifying radiation 8 is not particularly limited.

[0061] In one embodiment, the cleaning device 10 is configured to be held by an electrostatic clamp that holds the pattern forming apparatus MA during the exposure process performed by the EUV lithography equipment 100.

[0062] In one embodiment, a chuck 7 is provided for holding the patterning apparatus MA onto the support structure MT of the photolithography equipment 100 via electrostatic force. This chuck can be referred to as an electrostatic clamp. Similar electrostatic clamps can be used to hold the substrate W. In one embodiment, the chuck includes a dielectric component.

[0063] During the exposure process, the electrostatic clamp holds the patterning apparatus MA to the support structure MT. For example, when it is desired to clean the optical element, the electrostatic clamp is used to hold the cleaning apparatus 10 to the support structure MT. Therefore, the cleaning apparatus 10 has the same position as the patterning apparatus MA during the exposure process.

[0064] The cleaning device 10 can be transported / handled in the same manner as the patterning apparatus MA. For example, the same robot can be used to move the cleaning device 10 in the lithography equipment 100. In an embodiment, the cleaning device 10 has the same shape, volume, and clamping function as a standard EUV patterning apparatus MA.

[0065] The cleaning device 10 is a separate component from the rest of the lithography apparatus 100. The cleaning device 10 can be used with existing lithography apparatus 100 to improve its cleaning capabilities. Existing lithography apparatus 100 can be retrofitted using the cleaning device 10.

[0066] By configuring the cleaning device 10 to be clamped to the support structure MT, the cleaning device 10 can clean the surface from the normal position of the pattern forming apparatus MA. From this position, the cleaning device 10 can reach both the irradiation system IL and the projection system PS using the purifying radiation 8. A single cleaning device 10 can clean the optical elements in both the irradiation system IL and the projection system PS without movement.

[0067] In this embodiment, the cleaning device 10 has the standard dimensions of a pattern forming apparatus MA for EUV lithography. The pattern forming apparatus has a standard size and shape.

[0068] The first nominal size of the pattern forming apparatus MA is 6.0” × 6.0” × 0.25”. In one embodiment, the cleaning device 10 has a side length of approximately 152 mm. In another embodiment, the cleaning device 10 has a side length of at least 151.6 mm. In yet another embodiment, the cleaning device 10 has a side length of at most 152.4 mm. In one embodiment, the cleaning device 10 has a thickness of approximately 6.35 mm. In another embodiment, the cleaning device 10 has a thickness of at least 6.25 mm. In yet another embodiment, the cleaning device 10 has a thickness of at most 6.45 mm.

[0069] The second nominal size of the pattern forming apparatus MA is 6.0” × 6.0” × 0.15”. In one embodiment, the cleaning device 10 has a thickness of approximately 3.80 mm. In another embodiment, the cleaning device 10 has a thickness of at least 3.70 mm. In yet another embodiment, the cleaning device 10 has a thickness of up to 3.90 mm.

[0070] The third nominal size of the pattern forming apparatus MA is 7.0” × 7.0” × 0.25”. In one embodiment, the cleaning device 10 has a side length of approximately 177.4 mm. In another embodiment, the cleaning device 10 has a side length of at least 177.0 mm. In yet another embodiment, the cleaning device 10 has a side length of at most 177.8 mm.

[0071] The fourth nominal size of the pattern forming apparatus MA is 230mm × 230mm × 9mm. In one embodiment, the cleaning device 10 has a side length of approximately 230mm. In another embodiment, the cleaning device 10 has a side length of at least 229.6mm. In yet another embodiment, the cleaning device 10 has a side length of at most 230.0mm. In one embodiment, the cleaning device 10 has a thickness of approximately 9mm. In another embodiment, the cleaning device 10 has a thickness of at least 8.90mm. In yet another embodiment, the cleaning device 10 has a thickness of at most 9.10mm.

[0072] In one embodiment, the cleaning device 10 has the same weight as a standard patterning device MA used for EUV lithography. In another embodiment, the cleaning device 10 weighs at least about 200g and at most about 1000g, for example, about 300g or about 500g. In yet another embodiment, the cleaning device 10 has a mass of at least about 100g and at most about 200g. In yet another embodiment, the cleaning device 10 has a mass of at least 1000g and at most 2000g, for example, about 1050g.

[0073] In this embodiment, the cleaning device 10 is square in plan view. However, the sides of the cleaning device 10 may not have exactly the same length, meaning the cleaning device 10 is not a perfect square shape.

[0074] like Figure 4 As depicted, in one embodiment, the cleaning device 10 includes an energy source 4. The energy source 4 is configured to provide energy to the radiation source 2 to supply the purification radiation 8. The energy source 4 is configured to power the cleaning device 10. In one embodiment, the cleaning device 10 can be powered independently of the rest of the lithography apparatus 100.

[0075] In this embodiment, the energy source 4 is a battery. For example, the energy source may be a lithium-ion battery. In this embodiment, the energy source 4 is rechargeable. For example, the energy source 4 can be charged between uses via contacts or touch points. Alternatively, the energy source 4 can be recharged between uses via contactless charging.

[0076] In one embodiment, the lithography apparatus 100 includes a library. The library is used to store the cleaning device 10. In another embodiment, the library is configured to store one or more pattern forming devices MA in addition to the cleaning device 10. The library can store multiple cleaning devices 10. This allows one cleaning device 10 to be used while another cleaning device is being recharged. For example, this would be helpful if the power source 4 of the cleaning device 10 is depleted before the optical elements are fully cleaned.

[0077] In one embodiment, the library includes a charging station configured to charge the energy source 4 of the cleaning device 10. For example, the library may include contacts or points for charging the energy source 4. Alternatively, the library may include a contactless charging station for charging the energy source 4.

[0078] Different cleaning devices 10 can be provided to supply different types of clean radiation. For example, the cleaning device 10 can provide clean radiation 8 of different wavelengths or wavelength ranges. Alternatively or additionally, different cleaning devices 10 can be configured to supply different doses of contamination radiation 8. Different cleaning devices 10 can be configured to supply clean radiation 8 with different characteristics suitable for cleaning different components. For example, one cleaning device 10 can be optimized or fully utilized for cleaning the optical elements of the irradiation system IL, while another cleaning device 10 can be optimized or fully utilized for cleaning the optical elements of the projection system PS.

[0079] The energy source 4 is not necessarily a battery. For example, in one embodiment, the cleaning device 10 includes an induction coil. The induction coil is configured to receive electrical energy from an electromagnetic field. The induction coil is electrically connected to the radiation source 2 to supply energy to the radiation source 2 to supply the purifying radiation 8. Inductive charging can be used for the energy source 4.

[0080] In one embodiment, the electrostatic clamp has an induction coil configured to supply electrical energy to the cleaning device 10. The induction coil of the cleaning device 10 can be connected to the induction coil in the electrostatic clamp. This allows the cleaning device 10 to be energized while simultaneously supplying decontamination radiation 8 for cleaning the optical elements.

[0081] like Figure 4 As depicted, in one embodiment, the cleaning device 10 includes a focusing element 3. The focusing element 3 is configured to focus and guide the purifying radiation 8 supplied by the radiation source 2. The purifying radiation 8 is directed toward one or both of the irradiation system IL and the projection system PS.

[0082] like Figure 4 As shown, in one embodiment, the cleaning device 10 includes a controller 5. The controller 5 is configured to control the supply of the purifying radiation 8 from the radiation source 2. Light emission can be automatically triggered by the built-in controller 5. Alternatively, light emission can be manually triggered.

[0083] like Figure 4 As shown, in one embodiment, the cleaning device 10 includes a gas release module 6. The gas release module 6 is configured to supply gas 9 from the cleaning device 10. The cleaning device 10 is equipped with the gas release module 6 for controlled injection of gas 9. The gas 9 can be an active gas or a passive gas. In one embodiment, the gas release module 6 is configured to release one or more of hydrogen, nitrogen, and argon. The gas release module 6 can help create a specific environment around the cleaning device 10. The gas 9 can be used to help clean, purify, or purge the lithography equipment 100. The gas can help remove, i.e., pump away, desorbed or released water molecules.

[0084] However, the cleaning device 10 does not necessarily need to include the gas release module 6. For example, the cleaning or purging gas can be supplied by another part of the lithography equipment 100.

[0085] While the use of lithography equipment may be specifically mentioned herein in relation to IC manufacturing, it should be understood that the lithography equipment described herein may have other applications, such as manufacturing integrated optical systems, guiding and inspecting patterns for magnetic domain memory, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, etc. Those skilled in the art will understand that in the context of such alternative applications, any use of the terms “wafer” or “die” herein is considered synonymous with the more general terms “substrate” or “target portion,” respectively. The substrate mentioned herein may be processed before or after exposure, for example in track or coating development systems (i.e., tools that typically apply a resist layer to the substrate and develop the exposed resist), metrology tools, and / or inspection tools. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Furthermore, for example, a substrate may be processed more than once for the manufacture of multilayer ICs, such that the term “substrate” as used herein may also refer to a substrate that has contained multiple processed layers.

[0086] Where context permits, the term "lens" can refer to any one or a combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic, and electrostatic optical components.

[0087] Although reference may be specifically made to EUV lithography equipment herein, it should be understood that the invention can also be used in other lithography equipment, such as lithography equipment using deep ultraviolet (DUV) radiation or in electron beam lithography equipment.

[0088] Although electrostatic clamping may be specifically referred to herein, it should be understood that the invention is not limited thereto and may also be used in conjunction with other clamping methods, such as vacuum clamping or capillary clamping.

[0089] Although specific embodiments of the invention have been described above, it should be understood that the invention can be practiced in ways other than those described. For example, the cleaning device 10 may have a non-square shape, such as a circle or rectangle. Specifically, the shape of the cleaning device 10 may be selected depending on the shape of the pattern forming device MA.

Claims

1. A cleaning device for a lithographic apparatus, the cleaning device comprising: a radiation source configured to supply a decontaminating radiation capable of removing water or other contaminants from a surface of an optical component or other component of the lithographic apparatus; wherein the cleaning device is configured to be clamped by a clamp clamping a patterning device during an exposure process performed by the lithographic apparatus so that a position of the cleaning device is the same as a position of the patterning device during the exposure process; wherein the cleaning device has a standard size for a patterning device for EUV lithography.

2. The cleaning device of claim 1, wherein the lithographic apparatus is an EUV lithographic apparatus, wherein the clamp is an electrostatic clamp.

3. The cleaning device of claim 1, wherein the cleaning device has a square shape.

4. The cleaning device of claim 3, wherein the square shape has a side length of 152 mm.

5. The cleaning device of claim 3 or 4, wherein the cleaning device has a thickness of 6.35 mm.

6. The cleaning device of any preceding claim, comprising: an energy source configured to supply energy to the radiation source to supply the decontaminating radiation.

7. The cleaning device of claim 6, wherein the energy source is a battery.

8. The cleaning device of any of claims 1 to 5, comprising: an induction coil configured to receive electrical energy from an electromagnetic field, wherein the induction coil is electrically connected to the radiation source so as to supply energy to the radiation source to supply the decontaminating radiation.

9. The cleaning device of any preceding claim, comprising: a controller configured to control the supply of decontaminating radiation by the radiation source.

10. The cleaning device of any preceding claim, comprising: a gas release module configured to supply gas outwardly from the cleaning device.

11. The cleaning device of any preceding claim, comprising: an optical element configured to focus and direct the decontaminating radiation supplied by the radiation source.

12. A lithographic apparatus comprising: a radiation system configured to provide a projection beam of radiation; a support structure configured to support a patterning device to pattern the projection beam according to a desired pattern; a substrate table configured to hold a substrate; a projection system configured to project a patterned beam onto a target portion of the substrate; and the cleaning device of any preceding claim, wherein the support structure is configured to support the cleaning device.

13. The lithographic apparatus of claim 12, comprising: a library for storing the patterning device and the cleaning device.

14. The lithographic apparatus of claim 13, wherein the library comprises a charging station configured to charge a battery of the cleaning device. ​ 15. The lithographic apparatus according to claim 13 or 14, wherein the library stores a plurality of cleaning devices according to any of the claims.

16. The lithographic apparatus according to claim 15, wherein the cleaning devices are configured to supply decontaminating radiation having different properties from each other.

17. A method of removing water or other contaminants from a surface of an optical component or other component of a lithographic apparatus, the method comprising the steps of: clamping a cleaning device on a support structure so that the position of the cleaning device is the same as the position of a patterning device during an exposure process, wherein the support structure is configured to support a patterning device for patterning a projection beam according to a desired pattern; and supplying decontaminating radiation from the cleaning device so as to remove water or other contaminants from the surface of the optical component or other component of the lithographic apparatus, wherein the cleaning device has standard dimensions for a patterning device for EUV lithography.

18. A device manufacturing method, comprising the steps of: removing water or other contaminants from a surface of an optical component or other component of a lithographic apparatus by irradiation from a cleaning device, the cleaning device utilizing radiation capable of removing the water or other contaminants, wherein the cleaning device is configured to be clamped by a clamp clamping a patterning device during an exposure process performed by the lithographic apparatus so that the position of the cleaning device is the same as the position of the patterning device during an exposure process; replacing the cleaning device with a patterning device; providing a substrate at least partially covered by a layer of radiation-sensitive material; providing a projection beam of radiation using a radiation system; imparting the projection beam with a pattern in its cross-section using the patterning device; and projecting the patterned beam of radiation onto a target portion of the radiation- sensitive material layer; wherein the cleaning device has standard dimensions for a patterning device for EUV lithography.

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