Lithographic apparatus and airlock funnel

Abstract

A lithographic apparatus includes: a substrate table; a projection system; an airlock funnel; and a membrane. The substrate table is configured to hold a substrate. The projection system includes optics configured to project radiation onto a target portion of the substrate. A membrane is supported by the airlock funnel and disposed between the projection system and the substrate table. The airlock funnel may define a nozzle arranged to provide gas near the membrane such that the gas is preferentially directed toward a peripheral portion of the airlock funnel on a projection system side of the membrane. The last optical element of the projection system may have a central aperture, and the nozzle may be arranged to preferentially direct gas away from the central aperture in the last optical element.

Description

Cross-references to related applications

[0001] This application claims priority to EP application 23197801.6, filed September 15, 2023, and US application 63 / 655,324, filed June 3, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a photolithography apparatus comprising a gas lock funnel forming part of a dynamic gas lock. The photolithography apparatus may be an extreme ultraviolet (EUV) photolithography apparatus. The invention also relates to a gas lock funnel for use in a photolithography apparatus. Background Technology

[0003] A photolithography apparatus is a machine configured to apply a desired pattern onto a substrate. Photolithography apparatus can be used, for example, to manufacture integrated circuits (ICs). A photolithography apparatus can, for example, project a pattern at a patterning device (e.g., a mask) onto a radiation-sensitive material (resist) layer disposed on a substrate.

[0004] To project patterns onto a substrate, photolithography equipment can use electromagnetic radiation. The wavelength of this radiation determines the minimum size of the feature that can be formed on the substrate. Compared to photolithography equipment that uses radiation with a wavelength of, for example, 193 nm, photolithography equipment that uses extreme ultraviolet (EUV) radiation in the range of 4–20 nm (e.g., 6.7 nm or 13.5 nm) can be used to form smaller features on the substrate.

[0005] Photolithography equipment includes projection optics configured to project radiation onto a target portion of a substrate (e.g., a silicon wafer coated with resist) supported by a substrate stage (also called a wafer stage). Specifically, the projection optics are arranged to form an image of a patterned device (mask or template) on the target portion of the substrate. The photolithography equipment may also include a gas-lock funnel, which, for example, defines an exitaperture or exit window of the photolithography equipment housing at the projection optics to allow radiation to exit the housing of the projection optics and be projected onto the target portion of the substrate. The gas-lock funnel may form part of a dynamic gas lock. A film may be supported by the gas-lock funnel and may be disposed between the projection system and the substrate stage. This film is capable of suppressing out-of-band radiation (i.e., radiation not used for photolithographic exposure) from reaching the substrate and protecting the projection system optics from resist outgassing.

[0006] It is anticipated that an alternative gas-lock funnel and / or lithography apparatus may be provided that at least partially addresses one or more problems of existing apparatuses, whether or not such problems are explicitly identified herein. Summary of the Invention

[0007] According to a first aspect of this disclosure, a photolithography system is provided, comprising: an optical system including optical elements configured to project radiation onto a target portion of a substrate or onto a patterning apparatus; a second system; and a gas lock funnel disposed between the optical system and the second system; wherein the gas lock funnel defines a nozzle arranged to supply gas into the interior of the gas lock funnel such that, on the optical system side of the gas lock funnel, the gas is preferentially directed away from a plurality of optical elements of the optical system.

[0008] A lithography system may include a radiation source and lithography equipment.

[0009] It should be understood that the gas preferentially directed away from the optical elements of the optical system is intended to mean that at least a majority of the gas is directed toward an object not used for guiding radiation (towards the substrate or patterning device). In other words, preferably at least 50% of the gas can be directed so as not to impact the optical elements of the optical system, more preferably at least 75%, and even more preferably at least 85% of the gas can be directed so as not to impact the optical elements of the optical system. The optical elements of the optical system may include, for example, mirrors, sensors, etc.

[0010] The lithography system can be an EUV lithography system, and the optical elements of the optical system can be arranged to reflect EUV radiation. In some embodiments, the nozzles can be arranged such that gas is preferentially directed toward non-EUV reflective surfaces. The lithography system according to the first aspect is advantageous because it reduces the amount of debris carried by the gas flow toward the optical elements of the optical system.

[0011] In some embodiments, the second system may include a substrate stage configured to hold the substrate, and the optical system may include a projection system comprising optics configured to project radiation onto a target portion of the substrate.

[0012] In some embodiments, the second system may include a radiation source, and the optical system may include an irradiator system configured to project radiation onto a patterning device.

[0013] Radiation sources may include, for example, laser-generated plasma (LPP) radiation sources.

[0014] According to a second aspect of this disclosure, a photolithography apparatus is provided, comprising: a substrate stage configured to hold a substrate; a projection system including optics configured to project radiation onto a target portion of the substrate; and a gas lock funnel disposed between the projection system and the substrate stage; wherein the gas lock funnel defines a nozzle arranged to supply gas into the interior of the gas lock funnel such that, on the projection system side of the gas lock funnel, the gas is preferentially directed away from the optical elements of the projection system.

[0015] The projection system may also be referred to as the optical system below.

[0016] It should be understood that the gas preferentially directed away from the optical elements of the projection system means that at least a majority of the gas is directed toward an object not intended for guiding radiation toward the substrate. In other words, preferably at least 50% of the gas can be directed to avoid impacting the optical elements of the projection system, more preferably at least 75%, and even more preferably at least 85% of the gas can be directed to avoid impacting the optical elements of the projection system. The optical elements of the projection system may include, for example, mirrors, sensors, etc.

[0017] The lithography equipment can be an EUV lithography equipment, and the optical elements of the projection system can be arranged to reflect EUV radiation. In some embodiments, the nozzles can be arranged such that the gas is preferentially directed toward a non-EUV reflective surface.

[0018] In some embodiments, the nozzle can be arranged such that gas is preferentially directed toward the peripheral portion of the gaslock funnel. The gaslock funnel can be shaped such that its tapered shape matches the converging beam of the EUV radiation when it is focused onto the substrate. Thus, by preferentially directing gas toward the peripheral portion of the gaslock funnel, the gas will be directed away from the peripheral portion of the final optics of the projection system, or at worst, directed toward the peripheral portion of the final optics of the projection system.

[0019] Additionally or alternatively, in some embodiments, the nozzle may be arranged such that the gas is preferentially directed toward the wall of the projection system. Here, the wall of the projection system may include the wall of the housing of the projection optics. Similarly, when the (EUV) radiation beam is focused on the substrate, it does not incident on the wall of the projection system. Therefore, by preferentially directing the gas toward the wall of the projection system, the gas will be directed away from the optical elements of the projection system.

[0020] In use, the gas lock funnel forms part of a dynamic gas lock. The gas lock funnel can be considered as defining the exit aperture or exit window of the projection optics housing to allow radiation to exit the housing and be projected onto the target portion of the substrate. The film suppresses out-of-band radiation (i.e., radiation not used for photolithography exposure) from reaching the substrate and protects the projection system optics from resist outgassing.

[0021] The lithography apparatus may also include a radiation beam source. The radiation beam may include desired radiation having a first wavelength / wavelength range and undesired radiation having a second wavelength / wavelength range. The first wavelength / wavelength range may include EUV radiation. The second wavelength / wavelength range may include deep ultraviolet (DUV) radiation and / or infrared (IR) radiation.

[0022] In some embodiments, the photolithography apparatus may include a film supported by a gas-lock funnel and disposed between the projection system and the substrate stage. This arrangement may be referred to as a closed configuration. The film is positioned in the optical path of incident radiation. The film can be used to filter infrared (IR) and deep ultraviolet (DUV) radiation while transmitting EUV radiation. The nozzle defined by the gas-lock funnel may include two parts: a first part arranged to deliver gas to the projection system side of the film, and a second part arranged to deliver gas to the substrate stage side of the film. The gas flow from the first part of the nozzle serves as a particle stop flow to protect the film from particles within the projection optics housing impacting it.

[0023] During use, the membrane may rupture, potentially generating debris from it. This debris can be transmitted to the optical elements in the projection system via a gas flow from the nozzle. This results in a loss of optical performance, which is undesirable.

[0024] Conventionally, the gas flow from the gas lock funnel is symmetrically directed inward toward the optical axis of the lithography apparatus, such that the net gas flow is typically directed along the optical axis of the lithography apparatus (into the projection system and away from the projection system toward the substrate stage). In other words, conventionally, the nozzles are arranged to preferentially guide the gas toward the central portion of the gas lock funnel.

[0025] In the lithography apparatus according to the second aspect, the nozzle of the gas-lock funnel is arranged to preferentially guide the gas away from the optical elements of the projection system. For example, the nozzle of the gas-lock funnel can be arranged to preferentially guide the gas toward the peripheral portion of the gas-lock funnel, or more generally, to preferentially guide the gas flow toward the peripheral portion of the housing of the lithography apparatus. Advantageously, this ensures that in the event of film rupture, the amount of debris transferred to the optical elements of the projection system is reduced. This avoids loss of optical performance, which is advantageous. Although in the nozzle configuration according to the second aspect of the invention, a small portion of the gas flow can still be guided relatively centrally, preferentially guiding the gas toward the peripheral portion of the gas-lock funnel means that at least a considerable portion of the gas flow is deflected toward the housing of the lithography apparatus and the peripheral portion of the gas-lock funnel, and thus deflected away from the EUV mirrors in the projection system that may receive debris.

[0026] Another result of the lithography apparatus according to the second aspect is that the nozzles of the gas-lock funnel are arranged to preferentially guide the gas toward the peripheral portion of the gas-lock funnel or toward the wall of the projection system (opposite to the known arrangement). This will potentially change the thermal load of the gas from the nozzles on the optical elements of the projection system. This, in turn, affects the deformation of these optical elements caused by the gas, and thus affects one or more optical aberrations of the projection system. Any such aberration is best corrected through appropriate control of the projection optics. It should be understood that the corrections applied to the lithography apparatus according to the second aspect (where the nozzles of the gas-lock funnel are arranged to preferentially guide the gas toward the peripheral portion of the gas-lock funnel or toward the wall of the projection system) and the known arrangement (where the nozzles of the gas-lock funnel are arranged to preferentially guide the gas toward the central portion of the gas-lock funnel) will be different.

[0027] In some embodiments of the lithography apparatus, a film supported by a gas-lock funnel and positioned in the optical path of radiation may not be present. This arrangement may be referred to as an open configuration. It may be desirable to have the option of using the lithography apparatus in either an open or closed configuration. The lithography apparatus according to the second aspect has several advantages, wherein the nozzles of the gas-lock funnel are arranged to preferentially direct the gas away from the optical elements of the projection system, such that the thermal load from the gas (and therefore the processing of optical aberrations) is similar regardless of the presence or absence of a film.

[0028] In summary, the lithography apparatus according to the second aspect is advantageous because it allows for the selection of a film supported by an airlock funnel (i.e., allows the lithography apparatus to operate in a closed configuration), resulting in little or no loss of optical performance in the event of film rupture. Similarly, the lithography apparatus according to the second aspect also allows for operation in an open configuration without requiring excessively complex optical aberration handling.

[0029] It should be understood that the gas preferentially directed toward the outer portion of the gas lock funnel can mean that the gas is not directed along the optical axis of the lithography apparatus, but is directed toward (or along) one or more walls of the gas lock funnel or toward the housing of the lithography apparatus.

[0030] The gaslock funnel can define a conical volume through which the (converging radiation beam) propagates to the substrate. The size of the conical volume can be smaller at the end near the substrate stage and larger at the end near the projection optics. The conical volume can have a generalized, right-frusto-conical shape, i.e., it has been truncated (i.e., the apex has been removed) and the base can be a non-circular or circular right cone (i.e., the apex is above the center of the base). For example, the base of the volume can have a shape similar to the target portion of the substrate, but with rounded edges. The base of the volume can typically be kidney-shaped or banana-shaped. Alternatively, the base of the volume can typically be circular. It should be understood that the gas preferentially directed toward the peripheral portion of the gaslock funnel can mean that the gas is not directed along the axis of the gaslock funnel (which may be approximately aligned with the optical axis of the lithography apparatus) but toward one or more walls of the gaslock funnel (and consequently toward one or more walls of the housing of the projection system in the lithography apparatus).

[0031] As used in this article, the axis of the airlock funnel can be defined as follows.

[0032] In an embodiment where the airlock funnel defines a conical volume in a generalized, truncated conical shape, the axis of the airlock funnel can be the axis of the generalized, truncated conical volume.

[0033] Additionally or alternatively, the axis of the airlock funnel can be defined in such an orientation that the internal shape of the airlock funnel is generally the same in cross-sections in any plane perpendicular to the axis. For example, the cross-sectional shapes of the airlock funnel in two sections perpendicular to the axis but at different axial locations will be similar, i.e., one will be a proportional replica of the other. As mentioned above, these shapes can be either kidney-shaped or banana-shaped.

[0034] Alternatively or concurrently, the axis of the gas lock funnel can be defined as the optical axis of the lithography equipment within the gas lock funnel.

[0035] According to a third aspect of this disclosure, a photolithography apparatus is provided, comprising: a substrate stage configured to hold a substrate; a projection system including optics configured to project radiation onto a target portion of the substrate; and a gas lock funnel disposed between the projection system and the substrate stage; wherein the last optical element of the projection system has a central aperture; and wherein the gas lock funnel defines a nozzle arranged to supply gas into the interior of the gas lock funnel such that, on the projection system side of the gas lock funnel, the gas is preferentially directed away from the central aperture in the last optical element.

[0036] A projection system can also be called an optical system. In the following text, optical system and projection system can be used interchangeably.

[0037] In some embodiments, a lithography apparatus or system may include a film supported by a gas-lock funnel and disposed between a projection system or optical system and a substrate stage. This arrangement may be referred to as a closed configuration. The film is positioned in the optical path of radiation. The film can be used to filter infrared (IR) and deep ultraviolet (DUV) radiation while transmitting EUV radiation. The nozzle may include two parts: a first part configured to deliver gas to the projection system or optical system side of the film, and a second part configured to deliver gas to the substrate stage side of the film. The gas flow from the first part of the nozzle serves as a particle stop flow to protect the film from particles within the projection optics housing impacting it.

[0038] In use, the gas-lock funnel forms part of a dynamic gas lock. The gas-lock funnel can be considered as defining the exit aperture or exit window of the housing of a projection optics or optical system to allow radiation to be directed away from the housing and projected onto a target portion of the substrate. The film is used to suppress out-of-band radiation (i.e., radiation not used for photolithography exposure) from reaching the substrate and to protect the optics of the projection system or optical system from resist outgassing.

[0039] During use, the membrane may rupture, potentially generating debris from it. This debris can be transmitted through the gas flow from the nozzle to the optical elements in the projection or optical system. This results in a loss of optical performance, which is undesirable.

[0040] For newer EUV lithography systems, an increased numerical aperture (NA) is required to image smaller features. In some such high-NA systems, the final optical element in the projection or optics system is a large concave mirror with a central aperture. Radiation is guided through the aperture by optical elements near the field plane of the lithography apparatus. The radiation propagates radially through the aperture to a penultimate optical element near the gas lock funnel, which then directs the radiation to the final optical element, which focuses the radiation through the gas lock funnel onto the target portion of the substrate.

[0041] Conventionally, the gas flow from the gas lock funnel is symmetrically directed inward toward the optical axis of the lithography apparatus or system, such that the net gas flow is typically directed along the optical axis of the lithography apparatus or system (into the projection system / optical system and away from the projection system / optical system toward the substrate stage). However, in high-NA systems, this arrangement directs the gas flow toward the central aperture of the last optical element, i.e., toward the optical element in or near the field plane of the lithography apparatus or system. Any contamination on this optical element is particularly detrimental because it adversely affects slit uniformity (i.e., the uniformity of radiation dose delivered to different portions of the target portion of the substrate), which in turn adversely affects critical dimension uniformity (CDU).

[0042] According to the third aspect, the nozzles of the lithography apparatus are arranged to supply gas, which is preferentially directed away from or near any optical elements in the field plane of the lithography apparatus. This is advantageous because it avoids loss of slit uniformity and critical dimension uniformity in the event of film rupture.

[0043] The final optical element of a projection system (or optical system) may be an optical element of the projection system (or optical system) that is incident on the target portion of the substrate before being projected onto it.

[0044] Another consequence of the lithography apparatus according to the third aspect is that the nozzles of the gas-lock funnel are arranged to preferentially direct the gas away from the central aperture in the last optical element (opposite to the known arrangement). This will potentially alter the thermal load of the gas from the nozzles on the optical elements of the projection system (or optical system). This, in turn, affects the gas-induced deformation of these optical elements, and thus affects one or more optical aberrations of the projection system (or optical system). Any such aberration is best corrected through appropriate control of the projection optics. It should be understood that the corrections applied to the lithography apparatus according to the third aspect (where the nozzles of the gas-lock funnel are arranged to preferentially direct the gas away from the central aperture in the last optical element) and the known arrangement (where the nozzles of the gas-lock funnel are arranged to preferentially direct the gas toward the central portion of the gas-lock funnel) will be different.

[0045] In some embodiments of a lithography apparatus or system, a film supported by a gas-lock funnel and positioned in the radiation optical path may not be present. This arrangement may be referred to as an open configuration. It may be desirable to have the option to use the lithography apparatus or system in either an open or closed configuration. The lithography apparatus according to the third aspect has several advantages, wherein the nozzles of the gas-lock funnel are arranged to preferentially direct the gas away from the central aperture in the last optical element, such that the thermal load from the gas (and therefore the processing of optical aberrations) is similar regardless of the presence or absence of a film.

[0046] In summary, the lithography apparatus according to the third aspect is advantageous because it allows for the selection of a film supported by an airlock funnel (i.e., allows the lithography apparatus to operate in a closed configuration), resulting in little or no loss of optical performance in the event of film rupture. Similarly, the lithography apparatus according to the third aspect also allows for operation in an open configuration without requiring significantly different optical aberration handling.

[0047] According to the third aspect, the nozzle of the lithography apparatus can be arranged to supply gas into the interior of the gaslock funnel, such that on the projection system side of the gaslock funnel, the gas is preferentially directed away from the optical elements of the projection system.

[0048] The projection system of the lithography apparatus according to the third aspect may include a second optical element, which is arranged such that a line extending from the gas lock funnel to the central aperture of the last optical element intersects the second optical element.

[0049] Advantageously, because the nozzle is arranged to preferentially guide the gas away from the central aperture in the last optical element, the gas is directed away from the second optical element, which ensures that in the event of membrane rupture, the membrane residue is directed away from the second optical element.

[0050] According to the third aspect, the projection system of the lithography apparatus may include a secondary optical element. A second optical element can direct radiation to the secondary optical element, and the secondary optical element can direct radiation to the final optical element.

[0051] The second optical element can be, for example, placed in or near the field plane of the photolithography apparatus.

[0052] In use, a photolithography apparatus is operated to illuminate a photomask (patterning device) with a radiation beam and to project an image of the photomask onto a substrate (e.g., a silicon wafer coated with resist) supported by a substrate stage using a projection system. In other words, the plane in which the photomask lies is optically conjugate to the plane in which the substrate lies. The planes of the photomask and the substrate can be referred to as field planes. As used herein, the field plane is intended to represent any plane that is optically conjugate to the planes of the photomask and the substrate.

[0053] The second optical element can intersect with the field plane of the photolithography equipment.

[0054] In such an embodiment, it is particularly important that a portion of the second optical element intersecting the field plane remains uncontaminated. This portion may be referred to as the caustic region of the optical element.

[0055] The photolithography system or apparatus of the first, second, or third aspect may further include a film supported by a gas-lock funnel and disposed between a projection system or optical system and a substrate stage or second system. The nozzle of the gas-lock funnel may be arranged to provide gas near the film.

[0056] The nozzle can be arranged to supply gas such that, on the projection system or optical system side of the gas-lock funnel, the gas is directed away from or near any optical element in the field plane of the lithography apparatus. In other words, the nozzle can be configured to supply gas such that no gas or only a negligible amount of gas impacts any optical element in or near the field plane of the lithography apparatus.

[0057] Any contamination on such optical elements in or near the field plane is particularly detrimental because it can adversely affect slit uniformity (i.e., the uniformity of radiation dose delivered to different portions of the target portion of the substrate), which in turn can adversely affect critical dimension uniformity (CDU). It is advantageous for the nozzles to be arranged to provide gas preferentially directed away from any optical elements in or near the field plane of the lithography apparatus, as this avoids such losses or losses of slit uniformity and critical dimension uniformity.

[0058] The nozzle can be configured to supply gas into the interior of the gaslock funnel, such that on the projection system or optical system side of the gaslock funnel, the gas is asymmetrically directed inward toward the optical axis of the lithography equipment or lithography system, such that the net gas flow is directed at a non-zero angle relative to the optical axis.

[0059] The nozzle can be arranged such that the net gas flow is deflected away from the optical axis in any direction (at a non-zero angle relative to the optical axis). In other words, the nozzle can be arranged such that the asymmetrical flow toward the optical axis can occur in any direction. It should be understood that, generally, a particular direction may be advantageous or preferred depending on the design of the optics of the projection system or optical system.

[0060] As described above, the internal volume of the airlock funnel can be a generalized, truncated conical volume with a bottom that has a shape similar to the target portion of the substrate. The target portion of the substrate can be elongated (and may be curved), with both a longer and a shorter dimension. The asymmetric flow inward toward the optical axis can be in the direction of the shorter dimension.

[0061] The target portion of the substrate can be elongated, having a longer dimension and a shorter dimension, and the nozzle can be arranged such that the asymmetrical flow toward the optical axis is in the direction of the shorter dimension.

[0062] The lithography equipment or system can be a scanning lithography equipment or system, and the nozzles can be arranged such that an asymmetrical flow directed inward toward the optical axis is in the scanning direction of the lithography equipment.

[0063] The nozzle can be arranged such that flow is provided in only one direction in a first linear direction in a plane perpendicular to the optical axis of the lithography device or lithography system.

[0064] The first linear dimension can be referred to as the y-direction. That is, the nozzle is arranged to provide flow in only one direction (e.g., only in the positive y-direction or the negative y-direction). The first linear dimension can be aligned with the shorter dimension of the target portion of the substrate. The first linear dimension can be aligned with the scanning direction of the photolithography apparatus.

[0065] Alternatively, in some embodiments, the nozzle may be arranged such that flow is provided in two opposite directions in a first linear direction in a plane perpendicular to the optical axis of the lithography apparatus or lithography system, wherein the flow velocities in the two opposite directions are not equal.

[0066] The nozzle can be arranged such that it provides flow in two opposite directions in a second linear direction in a plane perpendicular to the optical axis of the lithography device or lithography system.

[0067] This arrangement provides control knobs that can be used to optimize dynamic airlocks. For example, this can help achieve a more optimized spatial distribution of the transmembrane pressure differential (when present) and / or, preferably, less gas expansion and therefore lower thermal effects. Typically, a combination of different segmented inlets above and below the membrane can be used as control knobs to optimize the spatial distribution of the transmembrane pressure differential (when present).

[0068] The second linear dimension can be approximately perpendicular to the first linear dimension. This second linear dimension can be referred to as the x-direction. The second linear dimension can be aligned with the longer dimension of the target portion of the substrate. The second linear dimension can be aligned with the non-scanning direction of the photolithography apparatus.

[0069] Alternatively, in some embodiments, the nozzle may be arranged such that it provides substantially no flow in a second linear direction in a plane perpendicular to the optical axis of the lithography apparatus.

[0070] The nozzle can be arranged to supply gas into the interior of the gaslock funnel, such that the gas is directed to swirl around the optical axis of the lithography equipment or system on the projection or optical system side of the gaslock funnel.

[0071] The nozzle may include one or more orifices, the shape of which allows rotation of the gas to be applied on the projection system or optical system side of the membrane.

[0072] The aperture can, for example, be used to apply rotation to the gas based on the Coanda effect.

[0073] The nozzle may include one or more guide vanes shaped such that rotation is applied to the gas on the projection system or optical system side of the membrane.

[0074] These guide vanes can, for example, extend across an exit opening or slit. These guide vanes can also function as airfoils.

[0075] The nozzle may include an opening in the wall of the airlock funnel, wherein the opening extends only around a portion of the periphery of the airlock funnel.

[0076] An opening may be a slit extending around a portion of the axis of the airlock funnel. Typically, a nozzle may include multiple openings on the wall of the airlock funnel. These multiple openings may extend only around a portion of the periphery of the airlock funnel. The size, location, and spacing of these multiple openings allow for a desired net gas flow to be obtained on the projection system side of the airlock funnel.

[0077] An airlock funnel may include a sealing shroud having an inlet and / or nozzle configured to supply gas to an opening.

[0078] The lithography apparatus or system may also include a debris catcher arranged to capture debris. For example, in the event of film rupture, such debris may include film fragments. Additionally or alternatively, the debris may include fuel debris, such as tin debris, from a radiation source.

[0079] The lithography equipment or system may also include a gas source operable to deliver gas to the nozzle.

[0080] The gas may include, for example, hydrogen. Alternatively or alternatively, the gas may include nitrogen and / or clean air (e.g., extremely clean dry air or XCDA).

[0081] The projection system or optical system may include a housing in which optical components are disposed. The housing may define an aperture through which radiation propagates during use. The nozzle may be arranged to supply gas into the interior of the airlock funnel such that, on the projection system or optical system side of the airlock funnel, the net direction of the gas does not point towards the aperture.

[0082] It should be understood that, as used herein, the net direction of the gas not pointing towards the aperture is intended to indicate that if a line or arrow pointing towards the net direction of the gas extends toward the projection system or optical system, it will not intersect or pass through the aperture. Instead, it will intersect the wall of the housing.

[0083] To facilitate such embodiments, the shape of the airlock funnel can be modified relative to known devices. For example, the airlock funnel can define a volume, typically in the form of a truncated cone, which defines the axis of the airlock funnel. To ensure that the net direction of the gas flow on the optical system side does not point towards the aperture, the divergence or conicity of the airlock funnel can be increased.

[0084] The nozzle may include a plurality of apertures defined in the wall of the airlock funnel, the plurality of apertures being spaced apart circumferentially around the airlock funnel.

[0085] For example, there may be approximately 12 or 13 orifices distributed circumferentially around the airlock funnel.

[0086] In some embodiments, the nozzle may include more than one row (e.g., two or three rows) of orifices defined in the wall of the airlock funnel and spaced circumferentially around the airlock funnel.

[0087] Multiple apertures confined in the wall of the airlock funnel can be arranged asymmetrically around the axis of the airlock funnel.

[0088] For example, by providing more orifices on the first circumferential portion than on the second circumferential portion, the net direction of the gas flow can be tilted away from the axis of the airlock funnel and toward the second circumferential portion. To adapt this arrangement to an existing airlock funnel, one or more existing orifices on the second circumferential portion can be blocked.

[0089] The plurality of orifices confined in the wall of the airlock funnel may include at least two sets of orifices, each set comprising at least one of the plurality of orifices. Each set of orifices may be located on different circumferential portions of the airlock funnel. Orifices in any given set may share a common inlet or manifold, and each set may have a different manifold or inlet.

[0090] This can provide a more controllable and versatile arrangement for controlling the net direction of gas flow. For example, the net direction of gas flow can be controlled by independently controlling the flow rate supplied to manifolds of different orifice sizes.

[0091] According to a fourth aspect of this disclosure, a component is provided for use in a lithography apparatus or system according to the first, second, or third aspect of this disclosure, the component comprising an airlock funnel. Optionally, the component may further comprise a film supported by the airlock funnel.

[0092] According to a fifth aspect of this disclosure, an assembly for a lithography apparatus or lithography system is provided, the assembly including a gas lock funnel; wherein the gas lock funnel defines a nozzle arranged to supply gas into the interior of the gas lock funnel, such that on a first side of the gas lock funnel, the gas is preferentially directed toward a peripheral portion of the gas lock funnel.

[0093] The first side of the airlock funnel can be the side facing the larger portion of the conical airlock funnel.

[0094] The component may also include a membrane supported by an airlock funnel.

[0095] The nozzle can be arranged so that the gas is not guided along the axis of the airlock funnel.

[0096] An airlock funnel can define a volume, and the shape of the volume is usually in the form of a generalized, truncated conical volume that defines the axis of the airlock funnel.

[0097] The nozzle can be configured to supply gas into the interior of the airlock funnel, such that on the first side of the airlock funnel, the gas is asymmetrically directed inward toward the axis of the airlock funnel, such that the net gas flow is directed at a non-zero angle relative to the axis.

[0098] The nozzle can be arranged such that the net gas flow is deflected away from the axis in any direction (at a non-zero angle relative to the axis). In other words, the nozzle can be arranged such that the asymmetrical flow toward the axis can be in any direction. It should be understood that, generally, a particular direction may be advantageous or preferred, depending on the design of the optics of the projection system or the optical system or components of the lithography equipment used in the lithography system.

[0099] The cross-sectional shape of the airlock funnel in a plane perpendicular to its axis can be elongated, having a longer dimension and a shorter dimension, and the nozzle can be arranged such that the asymmetrical flow toward the axis is in the direction of the shorter dimension.

[0100] The nozzle can be arranged such that flow is provided in only one direction in a first linear direction in a plane perpendicular to the axis of the airlock funnel.

[0101] The first linear dimension can be referred to as the y-direction. That is, the nozzle is arranged to provide flow only in one direction (e.g., only in the positive y-direction or the negative y-direction). The first linear dimension can be aligned with the shorter dimension of the cross-sectional shape of the gas-lock funnel in a plane perpendicular to its axis. In use, the first linear dimension can be aligned with the scanning direction of the lithography apparatus.

[0102] Alternatively, in some embodiments, the nozzle may be arranged such that it provides flow in two opposite directions in a first linear direction in a plane perpendicular to the axis of the airlock funnel, wherein the flow velocities in the two opposite directions are not equal.

[0103] The nozzle can be arranged such that it provides gas flow in two opposite directions in a second linear direction in a plane perpendicular to the axis of the airlock funnel.

[0104] This arrangement provides control knobs that can be used to optimize dynamic airlocks. For example, this can help achieve a more optimized spatial distribution of the transmembrane pressure differential (when present) and / or, preferably, less gas expansion and therefore lower thermal effects. Typically, a combination of different segmented inlets above and below the membrane can be used as control knobs to optimize the spatial distribution of the transmembrane pressure differential (when present).

[0105] The second linear dimension can be approximately perpendicular to the first linear dimension. This second linear dimension can be referred to as the x-direction. The second linear dimension can be aligned with the longer dimension of the cross-sectional shape of the gas-lock funnel in a plane perpendicular to its axis. In use, the second linear dimension can be aligned with the non-scanning direction of the lithography apparatus.

[0106] Alternatively, in some embodiments, the nozzle may be arranged such that it provides substantially no flow in a second linear direction in a plane perpendicular to the axis of the airlock funnel.

[0107] The nozzle can be arranged to supply gas into the interior of the airlock funnel, such that the gas is directed on a first side of the airlock funnel to rotate about the axis of the airlock funnel.

[0108] The nozzle may include one or more orifices shaped such that rotation is applied to the gas on a first side of the membrane.

[0109] The aperture can, for example, be used to apply rotation to the gas based on the Coanda effect.

[0110] The nozzle may include one or more guide vanes shaped such that rotation is applied to the gas on a first side of the membrane.

[0111] These guide vanes can, for example, extend across an exit opening or slit. These guide vanes can also function as airfoils.

[0112] The nozzle may include an opening in the wall of the airlock funnel, wherein the opening extends only around a portion of the periphery of the airlock funnel.

[0113] The opening can be a slit extending around a portion of the axis of the airlock funnel.

[0114] The nozzle may include multiple orifices defined in the wall of the airlock funnel. The multiple orifices may be spaced apart circumferentially around the airlock funnel.

[0115] For example, there may be approximately 12 or 13 orifices distributed circumferentially around the airlock funnel.

[0116] In some embodiments, the nozzle may include more than one row (e.g., two or three rows) of orifices defined in the wall of the airlock funnel and spaced circumferentially around the airlock funnel.

[0117] Multiple apertures confined in the wall of the airlock funnel can be arranged asymmetrically around the axis of the airlock funnel.

[0118] For example, by providing more orifices on the first circumferential portion than on the second circumferential portion, the net direction of the gas flow can be tilted away from the axis of the airlock funnel and toward the second circumferential portion. To adapt this arrangement to an existing airlock funnel, one or more existing orifices on the second circumferential portion can be blocked.

[0119] The multiple orifices defined in the wall of the airlock funnel may include at least two sets of orifices. Each set of orifices may include at least one of the multiple orifices. Each set of orifices may be located on different circumferential portions of the airlock funnel. Orifices in any given set may share a common inlet or manifold, and each set may have a different manifold or inlet.

[0120] This can provide a more controllable and versatile arrangement for controlling the net direction of gas flow. For example, the net direction of gas flow can be controlled by independently controlling the flow rate supplied to manifolds of different orifice sizes.

[0121] According to a sixth aspect of this disclosure, a photolithography apparatus is provided, comprising: a substrate stage configured to hold a substrate; a projection system including optics configured to project radiation onto a target portion of the substrate; and a gas lock funnel disposed between the projection system and the substrate stage; wherein the gas lock funnel defines a nozzle arranged to supply gas into the interior of the gas lock funnel such that, on the projection system side of the gas lock funnel, the gas is preferentially directed toward the peripheral portion of the gas lock funnel.

[0122] The lithography apparatus according to the sixth aspect of this disclosure can incorporate any feature of the first, second, and third aspects of this disclosure. Attached Figure Description

[0123] Embodiments will now be described by way of example only with reference to the accompanying schematic diagrams, in which: - Figure 1 A lithography system including lithography equipment and a radiation source is shown; - Figure 2A It shows that it can form Figure 1 The first example gas flow structure of the dynamic gas lock in a part of the lithography apparatus shown can be referred to as an open configuration; - Figure 2B It shows that it can form Figure 1 The second example gas flow structure of the dynamic gas lock in a part of the lithography apparatus shown can be referred to as a closed configuration. - Figure 3 It is a schematic diagram of an open configuration, which includes a flow distribution chamber defined in the wall of the gas lock funnel and surrounding the optical axis of the lithography apparatus; - Figure 4A It is a schematic cross-sectional view of a closed arrangement (shown in the first plane), which includes a flow distribution chamber defined in the wall of the gas lock funnel and surrounding the optical axis of the lithography apparatus; - Figure 4B yes Figure 4AThe schematic cross-sectional view of the closed arrangement shown (in a second plane parallel to the first plane) includes a flow distribution chamber defined in the wall of the gas lock funnel and surrounding the optical axis of the lithography apparatus. - Figure 4C yes Figure 4A and 4B The schematic cross-sectional view of the closed arrangement shown (in a third plane orthogonal to the first and second planes) includes a flow distribution chamber defined in the wall of the gas lock funnel and surrounding the optical axis of the lithography apparatus. - Figure 5 schematically shown Figure 1 The arrangement of the last three optical elements of the projection system in the lithography equipment of the type shown; - Figure 6A Is it like this? Figures 4A to 4C The enclosed arrangement shown (in relation to) Figure 4A A first modified version of the schematic cross-sectional illustration (shown in the same plane) includes a flow distribution chamber defined in the wall of the gas-lock funnel and surrounding the optical axis of the lithography apparatus; - Figure 6B yes Figures 4A to 4C The enclosed arrangement shown (in relation to) Figure 4A A second modified version of the schematic cross-sectional illustration (shown in the same plane) includes a flow distribution chamber defined in the wall of the gas-lock funnel and surrounding the optical axis of the lithography apparatus; - Figure 7 Is it like this? Figures 4A to 4C The schematic diagram of the closed arrangement shown shows that the nozzles are arranged to provide gas near the film, such that the gas is directed toward the projection system (e.g., on the PS side of the projection system of the film when the film is present) so as to rotate around the optical axis of the lithography apparatus. - Figure 8A schematically shown Figure 1 Known type of dynamic airlock near the opening in the enclosed structure of the radiation source shown; - Figure 8B It shows Figure 8A The enlarged portion of the known arrangement shown; - Figure 9A The present disclosure shows the method for use Figure 1 An enlarged portion of the first embodiment of the new arrangement of the dynamic airlock near the opening in the enclosed structure of the radiation source shown; and - Figure 9B The present disclosure shows the method for use Figure 1 An enlarged portion of the second embodiment of a new arrangement of dynamic airlocks near the opening in the enclosed structure of the radiation source shown. Detailed Implementation

[0124] Figure 1A lithography system including a radiation source SO and a lithography apparatus LA is shown. The radiation source SO is configured to generate an EUV radiation beam B and supply the EUV radiation beam B to the lithography apparatus LA. The lithography apparatus LA includes an irradiation system IL, a support structure MT configured to support a patterning device MA (e.g., a mask), a projection system PS, and a substrate stage WT configured to support a substrate W.

[0125] The irradiation system IL is configured to adjust the EUV radiation beam B before it is incident on the patterning device MA. Furthermore, the irradiation system IL may include a faceted field mirror assembly 10 and a faceted pupil mirror assembly 11. Together, the faceted field mirror assembly 10 and the faceted pupil mirror assembly 11 provide the EUV radiation beam B with the desired cross-sectional shape and desired intensity distribution. The irradiation system IL may include other mirrors or devices besides or replacing the faceted field mirror assembly 10 and the faceted pupil mirror assembly 11.

[0126] After such adjustment, the EUV radiation beam B interacts with the patterning device MA. As a result of this interaction, a patterned EUV radiation beam B' is generated. A projection system PS is configured to project the patterned EUV radiation beam B' onto a substrate W. For this purpose, the projection system PS may include a plurality of mirrors 13, 14, configured to project the patterned EUV radiation beam B' onto the substrate W held by the substrate stage WT. The projection system PS can apply a reduction factor to the patterned EUV radiation beam B', thereby forming an image with 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 The projection system PS is shown as having only two mirrors 13 and 14, but the projection system PS may include a different number of mirrors (e.g., six or eight mirrors).

[0127] The substrate W may include a previously formed pattern. In this case, the photolithography apparatus LA aligns the image formed by the patterned EUV radiation beam B' with the pattern previously formed on the substrate W.

[0128] A relative vacuum, i.e., a small amount of gas (e.g., hydrogen) at a pressure much lower than atmospheric pressure, can be provided in the radiation source SO, the irradiation system IL, and / or the projection system PS.

[0129] For example, Figure 1The radiation source SO shown is of the type that can be called a laser-generated plasma (LPP) source. A laser system 1, which may include, for example, a CO2 laser, is arranged to deposit energy into a fuel, such as tin (Sn) supplied, for example, from a fuel emitter 3, via a laser beam 2. Although tin is mentioned in the description below, any suitable fuel can be used. The fuel can be, for example, in liquid form and can be, for example, a metal or alloy. The fuel emitter 3 may include a nozzle configured to guide tin, for example, in droplet form, along a trajectory toward the plasma formation region 4. The laser beam 2 is incident on the tin at the plasma formation region 4. The deposition of laser energy into the tin generates tin plasma 7 at the plasma formation region 4. During the de-excitation and recombination of electrons and ions in the plasma, radiation, including EUV radiation, is emitted from the plasma 7.

[0130] EUV radiation from the plasma is collected and focused by collector 5. Collector 5 includes, for example, a near-vertical incident radiation collector 5 (sometimes more generally referred to as a vertical incident radiation collector). Collector 5 may have a multi-layered mirror structure arranged to reflect EUV radiation (e.g., EUV radiation with a desired wavelength such as 13.5 nm). Collector 5 may have an elliptical structure with two focal points. The first focal point may be located at plasma formation region 4, and the second focal point may be located at intermediate focal point 6, as described below.

[0131] Laser system 1 can be spatially separated from radiation source SO. In this case, laser beam 2 can be delivered from laser system 1 to radiation source SO by means of a beam delivery system (not shown) including, for example, suitable guide mirrors and / or beam expanders and / or other optical devices. Laser system 1, radiation source SO and beam delivery system can be considered together as radiation system.

[0132] The radiation reflected by collector 5 forms an EUV radiation beam B. The EUV radiation beam B is focused at intermediate focus 6 to form an image of the plasma present in plasma formation region 4 at intermediate focus 6. The image at intermediate focus 6 acts as a virtual radiation source for the irradiation system IL. The radiation source SO is arranged such that intermediate focus 6 is located at or near the opening 8 in the enclosed structure 9 of the radiation source SO.

[0133] although Figure 1 The radiation source SO is described as a laser-generated plasma (LPP) source, but any suitable source, such as a discharge-generated plasma (DPP) source or a free-electron laser (FEL), can be used to generate EUV radiation.

[0134] Embodiments of the present invention relate to Figure 1 A novel arrangement of dynamic gas locks in a lithography system of the type shown. These dynamic gas locks can be incorporated into various parts of the lithography system.

[0135] For example, Figure 1 The lithography system shown may include a dynamic gas lock near the opening 8 in the enclosed structure 9 of the radiation source SO, wherein the radiation beam B leaves the radiation source and enters the irradiation system IL. Refer to Figures 8 to... Figure 9B Embodiments of this disclosure involving such dynamic airlocks are described.

[0136] Additional or alternative land, Figure 1 The lithography apparatus LA shown may include a dynamic gas lock near the exit aperture or exit window of the projection system PS, where a patterned radiation beam B' moves away from the projection system PS and propagates to the substrate W. Now refer to... Figures 2A to 7 Embodiments of this disclosure involving such dynamic airlocks are described.

[0137] Figure 2A and Figure 2B It shows that it can form Figure 1 The diagram shows two example gas flow structures of a dynamic gas lock 100, a portion of a photolithography apparatus LS. Each dynamic gas lock 100 includes a gas lock funnel 102.

[0138] The airlock funnel 102 can be considered as limiting the exit aperture of the housing of the projection system PS (see...). Figure 2A ) or exit window (see Figure 2B This allows radiation B' to exit from the housing of the projection system PS and be projected onto the target portion of the substrate W.

[0139] Figure 2A An arrangement is shown with a gas flow directed inward toward an optical axis 104 of the photolithography apparatus LA. The gas flows inward toward the optical axis 104 from all directions around this axis and forms: (i) an upward flow 106a flowing into the projection optics housing; and (ii) a downward flow 106b flowing down to the substrate W. This arrangement may be referred to as an open configuration. During exposure, the downward flow 106b serves to suppress contaminants, particularly preventing outgassing, from migrating into the housing of the projection system PS (where such contaminants can damage optical elements and degrade the optical performance of the projection optics).

[0140] Figure 2B An arrangement is shown in which a membrane 108 is positioned in the optical path to filter infrared (IR) and deep ultraviolet (DUV) radiation while transmitting EUV radiation. This arrangement may be referred to as a closed configuration. Figure 2B The arrangement shown has two gas flows toward the optical axis 104 of the lithography apparatus: an upward flow 106a and a downward flow 106b. For Figure 2BIn the arrangement shown, the upward flow 106a serves as a particle stop flow to protect the membrane 108 from particles within the housing of the projection system PS impacting the membrane 108, and can also be used to minimize the pressure difference across the membrane 108.

[0141] An arrangement (in) Figure 3 (Schematably shown in an open configuration) includes a flow distribution chamber 110, which is defined within the wall of a gas lock funnel 102 and surrounds the optical axis 104 of the lithography apparatus LA. Thus, the flow distribution chamber 110 provides a generally annular volume surrounding the optical axis 104 of the lithography apparatus. The flow distribution chamber is fluidly connected to the interior of the housing of the projection system PS from all sides surrounding the optical axis 104. A gas flow is provided into the gas flow distribution chamber through a gas inlet 112. To provide a uniform flow into the interior of the gas lock funnel 102 (rather than, for example, a larger flow from a portion of the flow distribution chamber closer to the gas inlet 112), a restrictive outlet nozzle 114 is provided between the flow distribution chamber 112 and the interior of the gas lock funnel 102, which is substantially surrounding the optical axis 104.

[0142] Figure 4A , Figure 4B and Figure 4C The closed layout is illustrated schematically. Figure 4A and 4B It is a cross-section in two parallel first and second planes. Figure 4C It is a cross-section in a third plane orthogonal to the first and second planes. The enclosed device includes a flow distribution chamber 110, which is defined within the wall of the gas lock funnel 102 and surrounds the optical axis 104 of the lithography apparatus LA. Therefore, the flow distribution chamber 110 provides a generally annular volume surrounding the optical axis 104 of the lithography apparatus. The flow distribution chamber 110 is fluidly connected to the interior of the projection system PS housing via a sealing cover 116. Gas flows through a gas inlet 112 (see...). Figure 4B It is supplied to the gas flow distribution chamber 110.

[0143] like Figure 4A As shown, the flow distribution chamber 110 is fluidly connected to the first pre-expansion chamber 118, and the first pre-expansion chamber 118 is fluidly connected to the first nozzle 114a. From Figure 4A , Figure 4B and Figure 4C It is understood that the first pre-expansion chamber 118 does not extend around the entire periphery of the axis 104. The first nozzle 114a is located on the projection system PS side of the membrane 108.

[0144] like Figure 4B As shown, the flow distribution chamber 110 is fluidly connected to the second pre-expansion chamber 120, and the second pre-expansion chamber 120 is fluidly connected to the second nozzle 114b. From Figure 4A , Figure 4B and Figure 4CIt is understood that the second pre-expansion chamber 120 does not extend around the entire periphery of the shaft 104. The second nozzle 114b is located on the substrate W side of the membrane 108.

[0145] Film 108 is used to suppress out-of-band radiation (i.e. radiation not used for photolithography exposure) from being transmitted to substrate W and to protect the PS optics of the projection system from resist outgassing.

[0146] The membrane is positioned in the optical path of radiation B'. This membrane can be used to filter infrared (IR) and deep ultraviolet (DUV) radiation while transmitting EUV radiation.

[0147] The nozzle may include two parts: a first part 114a is arranged to deliver gas to the projection system PS side of the membrane 108, and a second part 114b is arranged to deliver gas to the substrate stage WT side of the membrane 108. The gas flow from the first part of the nozzle 114a serves as a particle stop flow to protect the membrane 108 from particles within the projection optics PS housing impacting the membrane 108.

[0148] This invention relates to Figure 4A , Figure 4B and Figure 4C The type of closed arrangement shown and Figure 3 The open arrangement shown is of this type. However, the invention is particularly applicable to... Figure 4A , Figure 4B and Figure 4C The type of closed arrangement shown. Specifically, some embodiments of this disclosure relate to an arrangement in which the airlock funnel defines nozzles 114a, 114b, which are arranged to provide gas directed toward the projection system PS, such that gas 106a is preferentially directed toward the peripheral portion of the airlock funnel.

[0149] During use, the membrane 108 may rupture, generating debris from it. This debris can be delivered to the optical elements in the projection system PS via a gas stream 106a from the nozzle. This results in a loss of optical performance, which is undesirable.

[0150] Typically, the gas flow 106a from the gas lock funnel is symmetrically guided inward toward the optical axis 104 of the lithography apparatus LA, such that the net gas flow is typically guided along the optical axis 104 of the lithography apparatus LA (into the projection system PS and away from the projection system PS toward the substrate stage WT). This is in Figures 2A to 4C The arrow 122 is used to indicate this schematically. In other words, in the known arrangement, the nozzle is conventionally positioned to guide the gas preferentially toward the central portion of the airlock funnel.

[0151] In a photolithography apparatus LA according to some embodiments of the present disclosure, the nozzles 114a, 114b of the gas-lock funnel 102 are arranged preferentially toward the peripheral portion of the gas-lock funnel 102 or toward the wall-guided gas of the projection system PS. Advantageously, this ensures a reduction in the amount of debris transferred to the optical elements of the projection system PS in the event of film rupture. This avoids loss of optical performance, which is advantageous. The arrangement of the nozzles 114a, 114b of the gas-lock funnel 102 preferentially toward the peripheral portion of the gas-lock funnel 102 or toward the wall-guided gas of the projection system PS is... Figures 6A to 7 It is shown in the figure and discussed below.

[0152] It should be understood that the gas 106a being preferentially directed toward the outer portion of the gas lock funnel 102 can mean that the gas 106a is not directed along the optical axis 104 of the lithography apparatus LA but toward one or more walls of the gas lock funnel 102 or toward one or more walls of the projection system PS.

[0153] The gas lock funnel 102 can define a conical volume through which the (converging radiation beam) propagates to the substrate W. The size of the conical volume can be smaller at the end near the substrate stage WT and larger at the end near the projection optics PS. The conical volume can have a generalized, truncated conical shape, i.e., a right circular cone that has been truncated (i.e., the apex has been removed) and has a non-circular base (i.e., the apex is above the center of the base). The base of the volume can have a shape similar to the target portion of the substrate W, but with rounded edges. The base of the volume can be approximately kidney-shaped. It should be understood that the gas 106a is preferentially guided toward the peripheral portion of the gas lock funnel 102, which means that the gas 106a is not guided along the axis of the gas lock funnel (which can typically be aligned with the optical axis 104 of the lithography apparatus LA) but rather toward one or more walls of the gas lock funnel 102.

[0154] Some embodiments of this disclosure relate to a lithography apparatus LA, wherein the last optical element of the projection system PS has a central aperture; and wherein nozzles 114a, 114b are arranged to supply gas into the interior of the gas lock funnel (e.g., near the film 108), such that on the projection system PS side of the film 108, the gas 106a is preferentially directed away from the central aperture in the last optical element.

[0155] Figure 5 The arrangement 200 of the last three optical elements of the projection system PS is schematically shown.

[0156] For newer EUV lithography systems, there is a shift with an increased numerical aperture in order to image smaller features. In some such high-NA systems, the final optics 202 in the projection system is a large concave mirror with a central aperture 204. Radiation is directed through this aperture 204 by optics near the field plane of the lithography apparatus LA (e.g., optics in region 206). The radiation propagates through the aperture 204 toward the secondary optics 208 near the gaslock funnel 102, which directs the radiation to the final optics 202, which focuses the radiation through the gaslock funnel 102 onto the target portion of the substrate W.

[0157] Figure 5 The diagram also shows walls 210, 212, 214 that define a portion of the interior of the projection system PS, and a dynamic airlock 100 is schematically represented by a dashed box. Figure 5 A portion of wall 216 is also shown, which defines an environment in which the substrate W is disposed (radiation propagates through an aperture in wall 216, which defines an environment in which the substrate W is disposed).

[0158] The final optical element 202, the next final optical element 208, and the walls 212, 214 defining a portion of the interior of the projection system PS define a portion of the gas above the membrane, which is directed into the environment 218. It is understood that the gas can be removed from the environment by one or more vacuum pumps (not shown).

[0159] Conventionally, the gas flow from the gas lock funnel is symmetrically directed inward toward the optical axis of the lithography apparatus LA, such that the net gas flow is typically directed along the optical axis of the lithography apparatus (into the projection system PS and away from the projection system PS toward the substrate stage). For this typical arrangement, the flow direction within the environment 218 above the film is indicated by arrow 220. However, in high-NA systems, this arrangement directs the gas flow 106a toward the central aperture 204 in the last optical element 202, i.e., toward the optical element (in region 206) in or near the field plane of the lithography apparatus LA. Any contamination on such optical elements is particularly detrimental because it adversely affects slit uniformity (i.e., the uniformity of the radiation dose delivered to different portions of the target portion of the substrate W), which in turn adversely affects critical dimension uniformity (CDU).

[0160] In some embodiments, nozzles 114a, 114b are arranged to provide gas that is preferentially directed away from the central aperture 204 in the last optical element 202. This gas flow is schematically represented by arrow 222. It can be understood, for example, that this can be achieved if nozzles 114a, 114b are arranged to provide gas near membrane 108 such that, on the projection system PS side of membrane 108 (i.e., in environment 218), the gas is preferentially directed toward the peripheral portion of the airlock funnel or toward the wall 210 of the projection system PS.

[0161] In some embodiments, nozzles 114a, 114b are arranged to provide gas directed to or near any optical element in the field plane of the lithography apparatus LA. For example, nozzles 114a, 114b may be arranged to provide gas such that no gas or a negligible amount of gas impacts any optical element in or near the field plane of the lithography apparatus. This is advantageous because it avoids losses in slit uniformity and critical dimension uniformity.

[0162] The final optical element 202 of the projection system PS can be an optical element of the projection system PS that is incident on the target portion of the substrate W before being projected onto it.

[0163] In some embodiments, nozzles 114a, 114b are arranged to provide gas near membrane 108 such that, on the projection system PS side of membrane 108, the gas is preferentially directed toward the peripheral portion of the airlock funnel or toward the wall 210 of the projection system PS.

[0164] In some embodiments, the projection system PS includes a second optical element (in region 206) that is arranged such that a line extending from the airlock funnel 102 to the central aperture 204 of the last optical element 202 intersects the second optical element.

[0165] Advantageously, because the nozzles 114a, 114b are arranged to preferentially guide gas 106a away from the central aperture 204 in the last optical element 202, gas 106a is directed away from the second optical element. This ensures that in the event of a rupture of the membrane 108, any residue of the membrane 108 is directed away from the second optical element.

[0166] The projection system PS may include a secondary optical element 208. A second optical element may direct radiation to the secondary optical element 208, and the secondary optical element 208 may direct radiation to the final optical element 202.

[0167] The second optical element can be, for example, placed in or near the field plane of the lithography apparatus LA.

[0168] In use, the photolithography apparatus LA is operable to illuminate a photomask MA (patterning device) with a radiation beam B, and uses a projection system PS to form an image of the photomask MA on a substrate W (e.g., a silicon wafer coated with resist) supported by a substrate stage WT. In other words, the plane containing the photomask MA is optically conjugate to the plane containing the substrate W. The planes of the photomask MA and the substrate W can be referred to as field planes. As used herein, the field plane is intended to represent any plane that is optically conjugate to the planes of the photomask MA and the substrate W.

[0169] In some embodiments, the second optical element (in region 206) intersects the field plane of the lithography apparatus LA.

[0170] In such an embodiment, it is particularly important that a portion of the second optical element intersecting the field plane remains uncontaminated. This portion may be referred to as the caustic region of the optical element.

[0171] In some embodiments, nozzles 114a, 114b are arranged to provide gas near the film 108, such that on the projection system PS side of the film 108, gas 106a is directed away from or near any optical element in the field plane of the lithography apparatus LA.

[0172] Any contamination on or near such optical elements in the field plane is particularly detrimental because it can adversely affect slit uniformity (i.e., the uniformity of radiation dose delivered to different portions of the target portion of the substrate), which in turn can adversely affect critical dimension uniformity (CDU). It is advantageous that the nozzles 114a and 114b are arranged to provide gas preferentially directed away from any optical elements in or near the field plane of the lithography apparatus, as this avoids such losses or losses of slit uniformity and critical dimension uniformity.

[0173] In some embodiments, nozzles 114a, 114b are arranged to supply gas into the interior of the gaslock funnel 102 (e.g., near the membrane 108), such that on the projection system PS side of the gaslock funnel 102, gas 106a is asymmetrically directed inward toward the optical axis 104 of the lithography apparatus LA, such that the net gas flow is directed at a non-zero angle relative to the optical axis 104, as now referenced. Figure 6A and Figure 6B The subject of discussion. Figure 6A and Figure 6B All Figure 4A The schematic illustration shows a modified version of the closed arrangement, and in relation to Figure 4A The schematic diagram shows a closed arrangement in the same plane. The net gas flow entering the projection system PS is... Figure 6A and Figure 6B The arrow 124 is indicated schematically in the middle, and the arrow 124 forms a non-zero angle with the optical axis 104.

[0174] Nozzles 114a and 114b can be arranged such that the net gas flow is deflected away from the optical axis 104 in any direction (at a non-zero angle relative to it). In other words, nozzles 114a and 114b can be arranged such that the asymmetrical flow inward toward the optical axis 104 can be in any direction. It should be understood that, generally, a particular direction may be advantageous or preferred depending on the design of the projection optics of the projection system PS.

[0175] It should be understood that, typically, nozzles 114a, 114b may include multiple orifices, slits, or openings in the wall of the airlock funnel 102. For example, Figure 4A and Figure 4C (or Figure 6A and Figure 4C or Figure 6B and Figure 4C The portion of nozzle 114a shown is typically defined by a split aperture in the wall of the airlock funnel 102. Similarly, in Figure 4A , Figure 4B , Figure 4C , Figure 6A and Figure 6B The portion of nozzle 114a shown on the opposite side of optical axis 104 in any of them is generally defined by a separate aperture in the wall of airlock funnel 102.

[0176] It should also be understood that the desired net gas flow 106a direction into the projection system PS can be achieved by selecting or designing an appropriate structure that defines the orifice diameter of the nozzle. For example, typically, the size, position, and spacing of the orifice diameter can be selected to achieve the desired net gas flow 106a direction into the projection system PS.

[0177] As described above, the internal volume of the airlock funnel 102 can be a generalized truncated conical volume with a bottom having a shape similar to that of the target portion of the substrate W. The target portion of the substrate W can be elongated (and may be curved), having a longer dimension and a shorter dimension. The asymmetric flow inward toward the optical axis 104 can be in the direction of the shorter dimension (e.g., as shown in the image). Figure 6A and Figure 6B y direction in ).

[0178] The target portion of the substrate W can be elongated, having a longer dimension and a shorter dimension, and the nozzles 114a, 114b can be arranged such that the asymmetric flow inward toward the optical axis 104 is in the direction of the shorter dimension (e.g., the y-direction, as shown in the image). Figure 6A and Figure 6B (As shown).

[0179] The lithography equipment LA can be a scanning lithography equipment, and the nozzles 114a, 114b can be arranged such that the asymmetrical flow 106a directed inward toward the optical axis 104 is in the scanning direction of the lithography equipment.

[0180] In some embodiments, such as Figure 6A As shown, nozzles 114a and 114b can be arranged such that flow is provided in only one direction in a first linear direction in a plane perpendicular to the optical axis 104 of the lithography apparatus LA.

[0181] The first linear dimension can be referred to as the y-direction. That is, the nozzles 114a and 114b are arranged to provide flow only in one direction (e.g., only along the positive y-direction or the negative y-direction). The first linear dimension can be aligned with the shorter dimension of the target portion of the substrate W. The first linear dimension can be aligned with the scanning direction of the lithography apparatus LA.

[0182] Alternatively, in some embodiments, such as Figure 6B As schematically shown, nozzles 114a and 114b can be arranged such that flow is provided in two opposite directions in a first linear direction in a plane perpendicular to the optical axis 104 of the lithography apparatus LA, wherein the flow velocities in the two opposite directions are not equal. This is in Figure 6B The arrow 106a indicates the gas flow from both sides of the optical axis 104, which has different lengths.

[0183] In some embodiments, nozzles 114a, 114b can be arranged such that flow is provided in two opposite directions in a second linear direction in a plane perpendicular to the optical axis 104 of the lithography apparatus LA. That is, Figure 6A and Figure 6B Any of the embodiments shown can be used with Figure 4C The arrangement shown (which illustrates the gas flow inward from two directions in the x-direction) is a combination.

[0184] This arrangement provides control knobs that can be used to optimize the dynamic airlock 100. For example, this helps to achieve a more optimized spatial distribution of the pressure difference across the membrane 108 and / or, preferably, less gas expansion and therefore lower thermal effects. Typically, a combination of different segmented inlets above and below the membrane 108 can be used as control knobs to optimize the spatial distribution of the pressure difference across the membrane 108.

[0185] The second linear dimension can be approximately perpendicular to the first linear dimension. This second linear dimension can be referred to as the x-direction. The second linear dimension can be aligned with the longer dimension of the target portion of the substrate W. The second linear dimension can be aligned with the non-scanning direction of the lithography apparatus LA.

[0186] Alternatively, in some embodiments, the nozzle may be arranged such that it provides substantially no flow in a second linear direction in a plane perpendicular to the optical axis 104 of the lithography apparatus LA.

[0187] In some embodiments, nozzles 114a, 114b may be arranged such that the gas flow 106b below the film 108 (i.e., on the same side as the substrate W) substantially... Figure 4B As shown (which illustrates gas flows inward in two directions from the y-direction). Alternatively, in some embodiments, nozzles 114a, 114b may be arranged such that the gas flow 106b below the membrane 108 (i.e., on the same side as the substrate W) is skewed in a manner similar to the skew of the gas flow 106a above the membrane 108.

[0188] In some embodiments, nozzles 114a, 114b may be arranged to provide gas near the film 108, such that gas 106a is directed toward a projection system (e.g., on the projection system PS side of the film 108 when present) to rotate about the optical axis 104 of the lithography apparatus LA, as... Figure 7 As illustrated in the diagram.

[0189] Nozzles 114a, 114b may include one or more orifices shaped such that rotation is applied to the gas on the projection system PS side of membrane 108. The orifices may apply rotation to the gas, for example, based on the Coanda effect.

[0190] In some embodiments, nozzles 114a, 114b may include one or more guide vanes shaped to apply rotation to the gas on the projection system PS side of membrane 108. These guide vanes may, for example, extend across an exit opening or slit. The guide vanes may serve as airfoils to guide the flow 106a to rotate about optical axis 104.

[0191] In some embodiments, nozzles 114a, 114b may include openings in the wall of the airlock funnel 102, said openings extending only around a portion of the periphery of the airlock funnel 102. The openings may be slits extending around a portion of the axis 104 of the airlock funnel 102.

[0192] The airlock funnel 102 may include a sealing cover 116 having an inlet and / or nozzle configured to supply gas to the opening.

[0193] In some embodiments, the lithography apparatus LA further includes a debris catcher arranged to catch fragments of the film 108 in the event of a breakage of the film 108. The debris catcher may be located near the film 108 on its projection system PS side. Additionally or alternatively, the debris catcher may be located in or near the central aperture 204 of the last optical element 202 in the projection system PS.

[0194] The debris catcher may include an electrostatic device configured to attract debris toward it. In such an embodiment, the debris catcher may be located in or near the central aperture 204 of the last optical element 202 in the projection system PS.

[0195] Alternatively or concurrently, the debris trap may comprise a mesh structure, which may include, for example, a carbon nanotube membrane. In such an embodiment, the debris trap may be positioned near the membrane 108 to facilitate debris removal.

[0196] In some embodiments, the lithography apparatus LA may further include a gas source operable to deliver gas to nozzles 114a, 114b. The gas may be, for example, hydrogen.

[0197] Some embodiments of this disclosure relate to a component for use in a photolithography apparatus LA, the component including a gas-lock funnel 102. Optionally, the component may also include a film 108 supported by the gas-lock funnel 102, as described above.

[0198] Nozzles 114a and 114b can be arranged such that the net gas flow 106a is skewed away from the axis of the airlock funnel 102 (at a non-zero angle relative to that axis) (see above). Figure 6A and Figure 6B (As discussed). Nozzles 114a, 114b can be arranged such that the inward, asymmetrical flow toward the axis can be in any direction. It should be understood that, generally, a particular direction may be advantageous or preferred, depending on the design of the projection optics of the projection system PS of the lithography apparatus LA using this component.

[0199] The cross-sectional shape of the airlock funnel 102 in a plane perpendicular to its axis 104 can be elongated, having a longer dimension and a shorter dimension. The nozzles 114a, 114b can be arranged such that the asymmetrical flow 106a directed inward toward the axis 104 is in the direction of the shorter dimension.

[0200] The nozzle can be arranged such that flow is provided in only one direction in a first linear direction in a plane perpendicular to the axis 104 of the airlock funnel 102.

[0201] The first linear dimension can be referred to as the y-direction. That is, the nozzles 114a and 114b are arranged to provide flow only in one direction (e.g., only in the positive y-direction or the negative y-direction). The first linear dimension can be aligned with the shorter dimension of the cross-sectional shape of the gaslock funnel 102 in a plane perpendicular to its axis 104. In use, the first linear dimension can be aligned with the scanning direction of the lithography apparatus LA.

[0202] Alternatively, in some embodiments, nozzles 114a, 114b may be arranged such that flow is provided in two opposite directions in a first linear direction in a plane perpendicular to the axis 104 of the airlock funnel 102, wherein the flow velocities in the two opposite directions are not equal.

[0203] Nozzles 114a and 114b can be arranged such that they provide flow in two opposite directions in a second linear direction in a plane perpendicular to the axis 104 of the airlock funnel 102.

[0204] This arrangement provides control knobs that can be used to optimize the dynamic airlock 100. For example, this helps to achieve a more optimized spatial distribution of the pressure difference across membrane 108 and / or, preferably, less gas expansion and therefore lower thermal effects. Typically, a combination of different segmented flow inlets above and below membrane 108 can be used as control knobs to optimize the spatial distribution of the pressure difference across membrane 108.

[0205] The second linear dimension can be approximately perpendicular to the first linear dimension. This second linear dimension can be referred to as the x-direction. The second linear dimension can be aligned with the longer dimension of the cross-sectional shape of the gas-lock funnel 102 in a plane perpendicular to its axis 104. In use, the second linear dimension can be aligned with the non-scanning direction of the lithography apparatus LA.

[0206] Alternatively, in some embodiments, nozzles 114a, 114b may be arranged such that they provide substantially no flow in a second linear direction in a plane perpendicular to the axis 104 of the airlock funnel 102.

[0207] In some embodiments, nozzles 114a, 114b may be arranged to provide gas near the membrane, such that the gas is directed on a first side of the membrane 108 to rotate about the axis 104 of the airlock funnel 102.

[0208] In some embodiments, nozzles 114a, 114b may include one or more orifices shaped to apply rotation to the gas on a first side of membrane 108 (as seen above). Figure 7 (As discussed). The aperture can, for example, impose rotation on the gas according to the Coanda effect.

[0209] In some embodiments, nozzles 114a, 114b may include one or more guide vanes shaped to impart rotation to the gas on a first side of membrane 108. These guide vanes may, for example, extend across an exit opening or slit. These guide vanes may act as airfoils arranged to guide flow 106a.

[0210] In some embodiments, nozzles 114a, 114b may include openings in the wall of the airlock funnel 102, said openings extending only around a portion of the periphery of the airlock funnel 102. The openings may be slits extending around a portion of the axis 104 of the airlock funnel 102.

[0211] It should be understood that, in use, one or more inner walls of the airlock funnel 102 may form extensions of one or more walls 210, 212, 214 that define a portion of the interior of the projection system PS. Therefore, any reference herein to a gas flow preferentially directed toward the peripheral portion (or wall) of the airlock funnel 102 may include an arrangement in which gas is preferentially directed toward the walls 210, 212, 214 of the projection system PS.

[0212] Now refer to Figures 8A to 9B An embodiment of this disclosure describes such a dynamic airlock near an opening 8 in a closed structure 9 involving a radiation source SO, wherein a radiation beam B is moved away from the radiation source and enters an irradiation system IL. Figure 8A A known type of dynamic airlock 300 is schematically shown near an opening 8 in a closed structure 9 of a radiation source SO. Figure 8B It shows Figure 8A The known arrangement of the enlarged portion. Figure 9A An enlarged portion of a first embodiment of a novel arrangement of a dynamic airlock 400 near an opening 8 in a closed structure 9 of a radiation source SO, according to the present disclosure, is shown. Figure 9B An enlarged portion of a second embodiment of a novel arrangement of a dynamic airlock 400 near an opening 8 in a closed structure 9 of a radiation source SO, according to the present disclosure, is shown.

[0213] This known dynamic airlock 300 in Figure 8A and Figure 8B The diagram schematically illustrates the process of limiting tin debris moving away from the radiation source SO and into the lithography apparatus LA. It is a flow injected at the differential pump interface between the radiation source SO and the lithography apparatus (near the opening 8 in the housing 9 of the radiation source SO). The dynamic gas lock 300 includes one or more nozzles arranged to provide both: (i) a gas flow 310 into the radiation source SO; and (ii) a gas flow 320 into the lithography apparatus LA. These gas flows 310, 320 may include jets that are essentially supersonic or near-supersonic.

[0214] The gas flow 310 entering the radiation source SO (which includes a high-speed jet) reduces the number of tin particles that travel from the radiation source SO through the opening 8 to the lithography apparatus LA. Tin contamination in the lithography apparatus LA can lead to two significant problems: (a) transmission loss of optics in the lithography apparatus LA, directly reducing lithography yield; and (b) defects on the patterning device MA (mask), which can lead to wafer die yield loss. It is believed that known dynamic gas locks are suitable for blocking or hindering tin particles originating from the radiation source SO from reaching a certain size. Such particles can, for example, evaporate when interacting with the radiation beam emitted from the radiation source SO through the opening 8. Such particles can thus be prevented from reaching the irradiation system IL. However, relatively large particles may be difficult to block or hinder by dynamic gas locks. When interacting with the radiation beam and reaching downstream of the opening 8, such particles can, for example, undergo (partial) evaporation. These particles, now reduced in size, can then propagate, for example, toward the irradiation system or the optical components of the patterning device, causing the aforementioned problems.

[0215] In existing dynamic airlocks (see...) Figure 8A and Figure 8B The two dynamic gas lock gas flows 310 and 320 are symmetrical and are typically aligned with the optical axis 340 of the system. As a result, the gas flow 320 entering the lithography equipment LA is directly directed towards the inlet aperture 350 of the irradiation system IL.

[0216] However, a significant pressure difference exists between the source container 9 and the irradiation system IL. The inventors have recognized that, as a result of this pressure difference, any particles that travel from the radiation source SO through the aperture 8 to the irradiation system IL undergo significant acceleration as they enter the irradiation system IL via the inlet gas flow 320. Furthermore, once accelerated, such particles enter a relatively low pressure environment (and therefore experience relatively low drag) and travel along a path similar to that of the radiation beam B.

[0217] exist Figure 8B In the schematic diagram shown, the known arrangement includes two rows of apertures at different axial positions (in Figure 8B The cross-section shows two apertures from each row. The first row of apertures is in fluid communication with the first manifold or inlet 360 and typically supplies gas flow 310 to the radiation source SO. The second row of apertures is in fluid communication with the second manifold or inlet 362 and typically supplies gas flow 320 to the lithography apparatus LA.

[0218] like Figure 9A and Figure 9B As shown, a novel arrangement of the dynamic airlock 400 near the opening 8 in the enclosed structure 9 for the radiation source SO according to an embodiment of the present disclosure is arranged to supply gas to the interior of the airlock funnel, such that on the irradiation system IL side of the airlock funnel, the gas 320 is preferentially directed away from the optical elements of the irradiation system IL.

[0219] In particular, according to an embodiment of the present disclosure, a new arrangement of the dynamic gas lock 400 near the opening 8 in the closed structure 9 for the radiation source SO is arranged to supply gas to the interior of the gas lock funnel, such that on the irradiation system IL side of the gas lock funnel, the gas is asymmetrically directed inward toward the optical axis of the lithography apparatus, such that the net gas flow 320 is directed at a non-zero angle relative to the optical axis 340.

[0220] It should be understood that the optical element preferentially directed away from the irradiation system IL to guide the gas 320 is intended to indicate that at least a majority of the gas 320 is directed toward an object not used to guide radiation B (towards the substrate W or the patterning device MA). In other words, preferably at least 50% of the gas 320 can be directed so as not to impact the optical element of the irradiation system IL, more preferably at least 75%, and even more preferably at least 85% of the gas 320 can be directed so as not to impact the optical element of the irradiation system IL. The optical element of the irradiation system IL may include, for example, a mirror, a sensor, etc.

[0221] The illumination system IL can be considered as an optical system, while the radiation source SO can be considered as a secondary system.

[0222] The irradiation system IL includes a housing in which optical components 10 and 11 are housed. The housing defines an aperture 350 through which radiation B propagates during use. The nozzle of the dynamic airlock 400 is configured to supply gas into the interior of the airlock funnel such that, on the irradiation system IL side of the airlock funnel, the net direction of the gas 320 does not point towards the aperture 350.

[0223] It should be understood that, as used herein, the net direction of the gas 320 not pointing to the aperture 350 is intended to indicate that if a line or arrow 322 in the direction pointing to the net direction of the gas 320 extends toward the irradiation system IL, it will not intersect or pass through the aperture 350. Instead, it will intersect the wall of the housing.

[0224] To facilitate such an embodiment, the shape of the airlock funnel can be modified relative to known devices. For example, the airlock funnel can define a volume, typically in the form of a truncated conical volume, which defines the axis of the airlock funnel. To ensure that the net direction of the gas flow 320 on the irradiation system IL side does not point towards the aperture 350, the divergence or conicity of the airlock funnel can be increased. When comparing... Figure 9A or Figure 9B and Figure 8B At this time, one can see the airlock funnel diverging or the cone shape increasing.

[0225] In some embodiments, the nozzle includes a plurality of orifices defined in the wall of the airlock funnel, the plurality of orifices being spaced apart circumferentially around the airlock funnel. For example, approximately 12 or 13 orifices may be present circumferentially distributed around the airlock funnel. Figure 9A Only one such aperture can be seen in the cross-section. Figure 9B Only two such apertures can be seen in the cross-section.

[0226] In some embodiments, the nozzle may include more than one row (e.g., two or three rows) of orifices defined in the wall of the airlock funnel and spaced circumferentially around the airlock funnel.

[0227] like Figure 9A As schematically shown, a plurality of apertures defined in the wall of the airlock funnel can be arranged asymmetrically about the axis 340 of the airlock funnel. For example, through the first circumferential portion ( Figure 9A The right side provides a portion that is larger than the second circumference portion. Figure 9A (On the left side) More aperture, the net direction of gas flow 320 can be away from the axis 340 of the airlock funnel and towards the second circumferential portion ( Figure 9A (On the left side) tilted. To adapt this arrangement to an existing airlock funnel, one or more existing apertures on the second circumferential portion can be blocked.

[0228] like Figure 9B As schematically illustrated, the plurality of orifices defined in the wall of the airlock funnel may include at least two sets of orifices, each set of which may have a different manifold or inlet. Figure 9B The illustrative example shown depicts a set of separate manifolds 462, 464 (each serving a different set of orifices). Each set of orifices includes at least one of a plurality of orifices. Each set of orifices is positioned on different circumferential portions of the airlock funnel. Orifices in any given set may share a common inlet or manifold.

[0229] This arrangement (such as) Figure 9B (As shown) can provide a more controllable and versatile arrangement for controlling the net direction of gas flow 320. For example, the net direction of gas flow 320 can be controlled by independently controlling the flow rates of manifolds 462, 464 supplied to different sets of orifices. This arrangement (as shown) can provide a more controllable and versatile arrangement for controlling the net direction of gas flow 320. Figure 9B (As shown) It also allows the net direction of the gas flow 320 to be off-axis (as described above) or coaxial (i.e., similar to...) Figure 8A and Figure 8B (The known arrangement is shown). Furthermore, the new dynamic airlock 400 can switch between this off-axis and coaxial configuration by independently controlling the flow rate of the manifolds 462, 464 supplied to different sets of orifices.

[0230] Typically, the number, size, and distribution of nozzle orifices can be selected to control the net direction of the gas flow 320 entering the lithography equipment LA.

[0231] The new dynamic gas lock 400 prevents the gas flow 320 from entering the housing of the irradiation system IL by guiding the gas flow 320 away from the optical axis 340 and around the housing of the irradiation system IL to the exhaust port. This arrangement does not impose any changes on the gas budget in the radiation source SO or the lithography equipment LA.

[0232] In some embodiments, a type of tin trapping structure may be added to manage tin particles diverted away from the inlet of the irradiation system IL. Optionally, this can be used to manage such tin particles if nearby venting is available.

[0233] While this article provides specific references to the use of lithography equipment in IC manufacturing, it should be understood that the lithography equipment described herein can have other applications. Possible other applications include the fabrication of integrated optical systems, the guiding and detection of patterns in magnetic domain memory, flat panel displays, liquid crystal displays (LCDs), and film magnetic heads.

[0234] While embodiments of lithography equipment may be specifically referred to herein in the context of such equipment, these embodiments can be used in other equipment. The embodiments may form part of mask inspection equipment, metrology equipment, or any equipment that measures or processes objects such as wafers (or other substrates) or masks (or other patterning devices). These devices are commonly referred to as lithography tools. Such lithography tools may use vacuum conditions or ambient (non-vacuum) conditions.

[0235] Although specific references have been made above to the use of embodiments in the context of optical lithography, it should be understood that, where the context permits, the invention is not limited to optical lithography and can be used in other applications, such as imprint lithography.

[0236] Where the context permits, the embodiments may be implemented using hardware, firmware, software, or any combination thereof. Embodiments 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 machine-readable form (e.g., a computing device). For example, a machine-readable medium may include read-only memory (ROM); random access memory (RAM); magnetic storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagation signals (e.g., carrier waves, infrared signals, digital signals, etc.). Furthermore, firmware, software, routines, and instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are merely for convenience, and such actions are actually generated by a computing device, processor, controller, or other device executing the firmware, software, routines, instructions, etc., and in doing so, enable actuators or other devices to interact with the physical world.

[0237] This invention can also be formulated as terms:

[0238] 1. A photolithography system, comprising:

[0239] An optical system, including optical devices configured to project radiation onto a target portion of a substrate or onto a patterning device;

[0240] The second system; and

[0241] An airlock funnel is arranged between the optical system and the second system;

[0242] The airlock funnel defines a nozzle arranged to supply gas into the interior of the airlock funnel, such that, on the optical system side of the airlock funnel, the gas is preferentially directed away from a plurality of optical elements of the optical system.

[0243] 2. The lithography system according to Clause 1, wherein the second system includes a substrate stage configured to hold a substrate, and wherein the optical system includes a projection system including optics configured to project radiation onto the target portion of the substrate.

[0244] 3. The lithography system according to Clause 1, wherein the second system includes a radiation source, and wherein the optical system includes an irradiator system configured to project radiation onto a patterning apparatus.

[0245] 4. A photolithography apparatus, comprising:

[0246] A substrate stage, configured to hold the substrate;

[0247] A projection system, including optics configured to project radiation onto a target portion of the substrate; and

[0248] An airlock funnel is disposed between the projection system and the substrate stage;

[0249] The final optical element of the projection system has a central aperture; and

[0250] The airlock funnel defines a nozzle that is arranged to supply gas into the interior of the airlock funnel such that, on the projection system side of the airlock funnel, the gas is preferentially directed away from the central aperture in the last optical element.

[0251] 5. The lithography apparatus according to Clause 4, wherein the nozzle is arranged to supply the gas into the interior of the gaslock funnel such that, on the projection system side of the gaslock funnel, the gas is preferentially directed away from the optical elements of the projection system.

[0252] 6. The lithography apparatus according to Clause 4 or Clause 5, wherein the projection system includes a second optical element arranged such that a line extending from the gas lock funnel to the central aperture of the last optical element intersects the second optical element.

[0253] 7. The lithography apparatus according to Clause 6, wherein the second optical element intersects the field plane of the lithography apparatus.

[0254] 8. The lithography apparatus or lithography system according to any one of the preceding clauses further includes a film supported by the gas lock funnel and disposed between the projection system or the optical system and the substrate stage or the second system, wherein the nozzle of the gas lock funnel is arranged to provide the gas near the film.

[0255] 9. The lithography apparatus or lithography system according to any one of the preceding clauses, wherein the nozzle is arranged to provide the gas such that, on the projection system or optical system side of the gas lock funnel, the gas is directed away from or near any optical element in the field plane of the lithography apparatus.

[0256] 10. The lithography apparatus or lithography system according to any one of the preceding clauses, wherein the nozzle is arranged to supply the gas into the interior of the gaslock funnel such that, on the projection system or optical system side of the gaslock funnel, the gas is asymmetrically directed inward toward the optical axis of the lithography apparatus, such that the net gas flow is directed at a non-zero angle relative to the optical axis.

[0257] 11. The lithography apparatus or lithography system according to Clause 10, when directly or indirectly subordinate to Clause 2 or Clause 4, wherein the target portion of the substrate is elongated, having a longer dimension and a shorter dimension, and wherein the nozzle is arranged such that an asymmetrical flow toward the optical axis is in the direction of the shorter dimension.

[0258] 12. A lithography apparatus or lithography system according to Clause 10 or Clause 11, wherein the lithography apparatus is a scanning lithography apparatus, and wherein the nozzle is arranged such that an asymmetrical flow toward the optical axis is directed inward in the scanning direction of the lithography apparatus.

[0259] 13. A lithography apparatus or lithography system according to any one of clauses 10 to 12, wherein the nozzle is arranged such that flow is provided in only one direction in a first linear direction in a plane perpendicular to the optical axis of the lithography apparatus.

[0260] 14. The lithography apparatus or lithography system according to Clause 13, wherein the nozzle is arranged such that flow is provided in two opposite directions in a second linear direction in a plane perpendicular to the optical axis of the lithography apparatus.

[0261] 15. The lithography apparatus or lithography system according to any one of the preceding clauses, wherein the nozzle is arranged to supply the gas into the interior of the gaslock funnel such that, on the projection system or optical system side of the gaslock funnel, the gas is directed to rotate about the optical axis of the lithography apparatus.

[0262] 16. The lithography apparatus or lithography system according to Clause 15, wherein the nozzle includes one or more apertures, the one or more apertures being shaped to apply rotation to the gas on the projection system or optical system side of the gas lock funnel.

[0263] 17. A lithography apparatus or lithography system according to Clause 15 or Clause 16, wherein the nozzle includes one or more guide vanes shaped to apply rotation to the gas on the side of the projection system or optical system of the gas lock funnel.

[0264] 18. The lithography apparatus or lithography system according to any one of the preceding clauses, wherein the nozzle includes an opening in the wall of the gaslock funnel, wherein the opening extends only around a portion of the periphery of the gaslock funnel.

[0265] 19. The lithography apparatus or lithography system according to Clause 18, wherein the gas lock funnel includes a sealing cover having an inlet and / or nozzle arranged to supply gas to the opening.

[0266] 20. The lithography apparatus or lithography system according to any of the preceding claims further includes a debris catcher arranged to capture debris.

[0267] 21. The lithography apparatus or lithography system according to any of the preceding claims further includes a gas source operable to deliver gas to the nozzle.

[0268] 22. The lithography apparatus or lithography system according to any one of the preceding clauses, wherein the projection system or optical system includes a housing in which the optical device is disposed, wherein the housing defines an aperture through which the radiation propagates in use, and wherein the nozzle is arranged to supply the gas into the interior of the gaslock funnel such that the net direction of the gas does not point toward the aperture on the projection system or optical system side of the gaslock funnel.

[0269] 23. The lithography apparatus or lithography system according to any of the preceding claims, wherein the nozzle includes a plurality of apertures defined in the wall of the gas lock funnel, the plurality of apertures being circumferentially spaced around the gas lock funnel.

[0270] 24. The lithography apparatus or lithography system according to Clause 23, wherein a plurality of apertures defined in the wall of the gas lock funnel are arranged asymmetrically about the axis of the gas lock funnel.

[0271] 25. A lithography apparatus or lithography system according to Clause 23 or Clause 24, wherein a plurality of apertures defined in the wall of the gaslock funnel comprises at least two sets of apertures, each set of apertures comprising at least one aperture of the plurality of apertures, each set of apertures being disposed on different circumferential portions of the gaslock funnel, wherein the apertures of any given set share a common inlet or manifold, and wherein each set has a different manifold or inlet.

[0272] 26. A component used in a lithography apparatus or lithography system as described in any of the preceding clauses, the component comprising an airlock funnel; and a film supported by the airlock funnel.

[0273] 27. A component for use in a lithography apparatus or lithography system, the component comprising:

[0274] Airlock funnel;

[0275] The airlock funnel defines a nozzle arranged to supply gas into the interior of the airlock funnel, such that on a first side of the airlock funnel, the gas is preferentially directed toward the peripheral portion of the airlock funnel.

[0276] 28. The component according to Clause 27 further includes a membrane supported by the airlock funnel.

[0277] 29. The component according to Clause 27 or Clause 28, wherein the nozzle is arranged such that the gas is not guided along the axis of the airlock funnel.

[0278] 30. The component according to Clause 29, wherein the airlock funnel defines a volume, the shape of which is generally in the form of a generalized, truncated conical volume, the volume defining the axis of the airlock funnel.

[0279] 31. The component according to any one of clauses 27 to 30, wherein the nozzle is arranged to supply the gas to the interior of the airlock funnel such that, on a first side of the airlock funnel, the gas is asymmetrically directed inward toward the axis of the airlock funnel, such that the net gas flow is directed at a non-zero angle relative to the axis.

[0280] 32. The assembly according to Clause 31, wherein the airlock funnel has an elongated cross-sectional shape in a plane perpendicular to its axis, having a longer dimension and a shorter dimension, and wherein the nozzle is arranged such that an asymmetrical flow toward the axis is directed in the direction of the shorter dimension.

[0281] 33. The component according to any one of clauses 27 to 32, wherein the nozzle is arranged such that the flow is provided in only one direction in a first linear direction in a plane perpendicular to the axis of the airlock funnel.

[0282] 34. The assembly according to Clause 33, wherein the nozzle is arranged such that gas flow is provided in two opposite directions in a second linear direction in a plane perpendicular to the axis of the airlock funnel.

[0283] 35. The component according to any one of clauses 27 to 34, wherein the nozzle is arranged to supply the gas into the interior of the airlock funnel such that the gas is guided on a first side of the airlock funnel to rotate about the axis of the airlock funnel.

[0284] 36. The component according to Clause 35, wherein the nozzle includes one or more orifices shaped to apply rotation to the gas on the first side of the membrane.

[0285] 37. The assembly according to Clause 35 or Clause 36, wherein the nozzle includes one or more guide vanes, the shape of which is configured to impart rotation to the gas on a first side of the membrane.

[0286] 38. The component according to any one of clauses 27 to 37, wherein the nozzle includes an opening in the wall of the airlock funnel, wherein the opening extends only around a portion of the periphery of the airlock funnel.

[0287] 39. The component according to any one of Clauses 27 to 38, wherein the nozzle includes a plurality of apertures defined in the wall of the airlock funnel, the plurality of apertures being circumferentially spaced around the airlock funnel.

[0288] 40. The component according to Clause 39, wherein the plurality of apertures defined in the wall of the airlock funnel are arranged asymmetrically about the axis of the airlock funnel.

[0289] 41. The component according to Clause 39 or Clause 40, wherein the plurality of apertures defined in the wall of the airlock funnel comprises at least two sets of apertures, each set of apertures comprising at least one of the plurality of apertures, each set of apertures being provided on different circumferential portions of the airlock funnel, wherein these apertures of any given set share a common inlet or manifold and wherein each set has a different manifold or inlet.

[0290] While specific embodiments have been described above, it should be understood that the invention can be practiced in ways other than those described. The above description is intended to illustrate and not limit. Therefore, it will be apparent to those skilled in the art that modifications can be made to the described invention without departing from the scope of the following claims.

Claims

1. A photolithography system, comprising: An optical system, including optical devices configured to project radiation onto a target portion of a substrate or onto a patterning device; Second system; as well as An airlock funnel is arranged between the optical system and the second system; The airlock funnel defines a nozzle arranged to supply gas into the interior of the airlock funnel, such that, on the optical system side of the airlock funnel, the gas is preferentially directed away from a plurality of optical elements of the optical system.

2. The lithography system of claim 1, wherein the second system includes a substrate stage configured to hold a substrate, and the optical system includes a projection system comprising optics configured to project radiation onto the target portion of the substrate.

3. The lithography system of claim 1, wherein the second system includes a radiation source, and wherein the optical system includes an irradiator system configured to project radiation onto a patterning apparatus.

4. A photolithography apparatus, comprising: A substrate stage, configured to hold the substrate; A projection system, including optics configured to project radiation onto a target portion of the substrate; as well as An airlock funnel is disposed between the projection system and the substrate stage; The final optical element of the projection system has a central aperture; and The airlock funnel defines a nozzle arranged to supply gas into the interior of the airlock funnel, such that, on the projection system side of the airlock funnel, the gas is preferentially directed away from the central aperture in the last optical element.

5. The lithography apparatus of claim 4, wherein the nozzle is configured to supply the gas into the interior of the gaslock funnel such that, on the projection system side of the gaslock funnel, the gas is preferentially directed away from the optical elements of the projection system.

6. The lithography apparatus according to claim 4 or 5, wherein the projection system includes a second optical element arranged such that a line extending from the gas lock funnel to the central aperture of the last optical element intersects the second optical element.

7. The lithography apparatus according to claim 6, wherein the second optical element intersects with the field plane of the lithography apparatus.

8. The lithography apparatus or lithography system according to any one of the preceding claims further includes a film supported by the gas lock funnel and disposed between the projection system or the optical system and the substrate stage or the second system, wherein the nozzle of the gas lock funnel is arranged to provide the gas near the film.

9. The lithography apparatus or lithography system according to any one of the preceding claims, wherein the nozzle is arranged to provide the gas such that, on the projection system or optical system side of the gas lock funnel, the gas is directed away from or near any optical element in the field plane of the lithography apparatus.

10. The lithography apparatus or lithography system according to any one of the preceding claims, wherein the nozzle is arranged to supply the gas into the interior of the gaslock funnel such that, on the projection system or optical system side of the gaslock funnel, the gas is asymmetrically directed inward toward the optical axis of the lithography apparatus, such that the net gas flow is directed at a non-zero angle relative to the optical axis.

11. The lithography apparatus or lithography system of claim 10, when directly or indirectly dependent on claim 2 or claim 4, wherein the target portion of the substrate is elongated, having a longer dimension and a shorter dimension, and wherein the nozzle is arranged such that an asymmetrical flow toward the optical axis is directed in the direction of the shorter dimension.

12. The lithography apparatus or lithography system according to any one of the preceding claims, wherein the nozzle is arranged to supply the gas into the interior of the gaslock funnel such that, on the projection system or optical system side of the gaslock funnel, the gas is directed to rotate about the optical axis of the lithography apparatus.

13. The lithography apparatus or lithography system of claim 12, wherein the nozzle comprises one or more apertures, the shape of which causes rotation to be applied to the gas on the projection system or optical system side of the gas lock funnel.

14. The lithography apparatus or lithography system according to claim 12 or 13, wherein the nozzle includes one or more guide vanes, the shape of which causes rotation to be applied to the gas on the projection system or optical system side of the gas lock funnel.

15. The lithography apparatus or lithography system according to any one of the preceding claims, wherein the nozzle includes an opening in the wall of the gas lock funnel, wherein the opening extends only around a portion of the periphery of the gas lock funnel.

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