System for cleaning parts of a lithographic apparatus

Abstract

The described system comprises a cleaning tool. The cleaning tool is configured to be inserted in a lithographic apparatus in a first configuration, to be engaged by a tool handler of the lithographic apparatus, and to be used for cleaning a portion of the lithographic apparatus. The cleaning tool is configured to move from the first configuration to an extended second configuration after being engaged by the tool handler, such that the cleaning tool is in the second configuration when used for cleaning the portion of the lithographic apparatus. The system comprises a container configured to house the cleaning tool in the first configuration and to fit into the lithographic apparatus. The cleaning tool is configured to be inserted into the lithographic apparatus in the container, to be removed from the container by the tool handler for the cleaning, and to be returned to the container after the cleaning by means of the tool handler.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 931,864, filed November 7, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The descriptions in this article generally relate to systems and methods for cleaning parts of photolithography equipment. Background Technology

[0004] Photolithography (e.g., projection) equipment can be used, for example, to manufacture integrated circuits (ICs). In this case, a patterning apparatus (e.g., a mask) can contain or provide a pattern corresponding to a single layer of the IC (“design layout”), and this pattern can be transferred onto a target portion (e.g., comprising one or more dies) of a substrate (e.g., a silicon wafer) that has been coated with a layer of radiation-sensitive material (“resist”) via the pattern on the patterning apparatus. Typically, a single substrate contains multiple adjacent target portions, and the pattern is continuously transferred by the photolithography projection apparatus to the multiple adjacent target portions one target portion at a time. In one type of photolithography projection apparatus, the pattern on the entire patterning apparatus is transferred onto a target portion in one operation. Such an apparatus is commonly referred to as a stepper. In an alternative apparatus, commonly referred to as a step-scan apparatus, a projection beam scans the entire patterning apparatus in a given reference direction (“scanning” direction) while the substrate is moved synchronously parallel or antiparallel to this reference direction. Different portions of the pattern on the patterning apparatus are gradually transferred to a target portion. Typically, since the photolithography projection apparatus will have a reduction ratio M (e.g., 4), the speed F at which the substrate is moved will be 1 / M times the speed of the projection beam scanning pattern forming apparatus. Further information regarding the photolithography apparatus described herein can be obtained, for example, from US 6,046,792, which is incorporated herein by reference.

[0005] Before the pattern is transferred from the patterning apparatus to the substrate, the substrate may undergo various processes, such as primer coating, resist coating, and soft baking. After exposure, the substrate may undergo other processes (“post-exposure processes”), such as post-exposure baking (PEB), development, hard baking, and measurement / inspection of the transferred pattern. This series of processes serves as the basis for fabricating individual layers of devices (e.g., ICs). The substrate may then undergo various processes, such as etching, ion implantation (doping), metallization, oxidation, chemical mechanical polishing, etc., all intended to complete individual layers of the device. If several layers are required in the device, the entire process or its variations are repeated for each layer. Ultimately, a device will be present in each target portion of the substrate. These devices are then separated from each other by techniques such as dicing or sawing, whereby individual devices can be mounted on carriers, connected to pins, etc.

[0006] Fabricating devices such as semiconductor devices typically involves processing a substrate (e.g., a semiconductor wafer) using several fabrication processes to form various features and multiple layers of said device. Such layers and features are typically fabricated and processed using processes such as deposition, photolithography, etching, chemical mechanical polishing, ion implantation, and / or other processes. Multiple devices can be fabricated on multiple dies on a substrate and then separated into individual devices. This device fabrication process can be considered a patterning process. A patterning process involves a patterning step using a patterning apparatus in a photolithography apparatus, such as optical and / or nanoimprint lithography, to transfer a pattern from the patterning apparatus to the substrate, and the patterning process typically, but optionally, involves one or more associated patterning processing steps, such as resist development by a developing apparatus, baking the substrate using a baking tool, etching the pattern using an etching apparatus, etc. One or more measurement processes are typically involved in the patterning process.

[0007] Photolithography is a central step in the fabrication of devices such as integrated circuits (ICs), in which patterns formed on a substrate define the functional components of the device, such as microprocessors and memory chips. Similar photolithography techniques are also used to form flat panel displays, microelectromechanical systems (MEMS), and other devices.

[0008] As semiconductor manufacturing processes continue to advance, the size of functional components has been shrinking for decades, while the number of functional components, such as transistors, per device has been steadily increasing, following a trend commonly known as "Moore's Law." With current advanced technology, photolithography projection equipment is used to fabricate the layers of devices. This equipment projects a design layout onto a substrate using irradiation from a deep ultraviolet light source, resulting in individual functional components with dimensions sufficiently below 100 nm, i.e., less than half the wavelength of the radiation from the irradiation source (e.g., a 193 nm irradiation source).

[0009] The process of printing features with dimensions smaller than the classical resolution limit of a photolithographic projection apparatus is often referred to as low-k1 lithography according to the resolution formula CD = k1 × λ / NA, where λ is the wavelength of the radiation used (currently 248 nm or 193 nm in most cases), NA is the numerical aperture of the projection optics in the photolithographic projection apparatus, CD is the "critical size" (typically the smallest feature size to be printed), and k1 is an empirical resolution factor. Generally, the smaller k1 is, the more difficult it becomes to reproduce patterns on the substrate that resemble the shape and size planned by the designer to achieve specific electrical functionalities and performance. To overcome these difficulties, complex fine-tuning steps are applied to the photolithographic projection apparatus, design layout, or patterning apparatus. These steps include (e.g., but not limited to) optimization of NA and optical coherence settings, custom illumination schemes, the use of phase-shifting patterning apparatus, optical proximity correction (OPC, sometimes also called "optical and process correction") in the design layout, or other methods generally defined as "resolution enhancement techniques" (RET). As used herein, the term "projection optics" should be interpreted broadly to encompass various types of optical systems, including, for example, refractive optics, reflective optics, and aperture and reflective-refractive optics. The term "projection optics" may also include components that operate according to any of these design types for collectively or individually guiding, shaping, or controlling a projected radiation beam. The term "projection optics" can include any optical component in a lithographic projection apparatus, regardless of where the optical component is located in the optical path of the lithographic projection apparatus. Projection optics can include optical components for shaping, adjusting, and / or projecting radiation from a source before it passes through a patterning apparatus, and / or for shaping, adjusting, and / or projecting radiation after it has passed through the patterning apparatus. Projection optics typically exclude the source and the patterning apparatus. Summary of the Invention

[0010] According to an embodiment, a system for cleaning portions of a photolithography apparatus is provided. The system includes a cleaning tool and / or other components. The cleaning tool is configured to be inserted into the photolithography apparatus in a first configuration, engaged by a tool handler of the photolithography apparatus, and used to clean the portions of the photolithography apparatus. The cleaning tool is configured to move from the first configuration to an extended second configuration after engagement by the tool handler, such that the cleaning tool is in the second configuration when used to clean the portions of the photolithography apparatus.

[0011] In one embodiment, the system further includes a container configured to hold the cleaning tool in the first configuration and fitted into the lithography apparatus. The cleaning tool is configured to be inserted into the lithography apparatus, removed from the container by the tool handler for cleaning, and returned to the container by means of the tool handler after cleaning.

[0012] In one embodiment, the cleaning tool is configured to move from the first configuration to the second configuration when the cleaning tool is removed from the container by the tool handler for cleaning.

[0013] In one embodiment, the cleaning tool is configured to move from the second configuration to the first configuration when the cleaning tool is returned to the container by means of the tool disposal after cleaning.

[0014] In one embodiment, the container includes one or more retractable members configured to facilitate the retraction of the cleaning tool from a second configuration to a first configuration when the cleaning tool returns to the container after cleaning. In another embodiment, the one or more retractable members include a ridge in the container configured to push the cleaning tool when it returns to the container after cleaning.

[0015] In one embodiment, the portion of the lithography apparatus includes a mask fixture for a mask stage.

[0016] In one embodiment, the cleaning tool includes a cleaning mask.

[0017] In one embodiment, the tool handler includes a turntable clamp for a mask handler.

[0018] In one embodiment, the lithography apparatus is configured for deep ultraviolet (DUV) radiation.

[0019] In an embodiment, the first configuration includes a shrink configuration relative to the second configuration.

[0020] In one embodiment, the cleaning tool includes one or more links connected by hinged joints, the hinged links being configured to facilitate expansion or contraction between the first configuration and the second configuration. In another embodiment, the cleaning tool includes one or more flexible portions configured to facilitate expansion or contraction between the first configuration and the second configuration. In yet another embodiment, the cleaning tool includes one or more rotating portions configured to facilitate expansion or contraction between the first configuration and the second configuration.

[0021] In one embodiment, the cleaning tool includes one or more tool handler engagement surfaces configured to remain in a position and orientation corresponding to the tool handler regardless of whether the cleaning tool is in the first configuration or the second configuration.

[0022] In one embodiment, the cleaning tool includes one or more cleaning surfaces configured to move relative to one or more tool handler engagement surfaces as the cleaning tool moves between the first configuration and the second configuration. In another embodiment, the one or more cleaning surfaces are configured to contact one or more target surfaces of the portion of the lithography apparatus for cleaning when the cleaning tool is in the second configuration. In another embodiment, the one or more cleaning surfaces are configured to be parallel to the one or more target surfaces when the cleaning tool is in the second configuration. In yet another embodiment, the one or more target surfaces include one or more diaphragm surfaces of the lithography apparatus.

[0023] In one embodiment, the cleaning tool includes: a cleaning surface at least partially covered by a cleaning material; an identification surface located on the opposite side of the cleaning tool relative to the cleaning surface; and one or more identification features located between the cleaning surface and the identification surface, the one or more identification features being visible through the identification surface.

[0024] In one embodiment, the cleaning surface is opaque, while the identification surface is transparent.

[0025] In one embodiment, the cleaning tool includes one or more inner surfaces located between the cleaning surface and the identification surface. The one or more identification features are located on the one or more inner surfaces.

[0026] In an embodiment, the one or more identification features include one or both of a barcode and an alignment mark.

[0027] In one embodiment, the cleaning tool includes an illumination source located inside the cleaning tool between the cleaning surface and the identification surface. The illumination source is configured to provide illumination such that the one or more identification features are visible through the identification surface.

[0028] In one embodiment, the illumination source includes a light-emitting diode (LED). In another embodiment, the illumination source includes an illumination guide configured to direct illumination from the LED toward and through the one or more identification features.

[0029] In one embodiment, the illumination source includes one or more reflectors configured to direct ambient light from below the cleaning tool through the interior of the cleaning tool toward the one or more identification features and through the identification surface.

[0030] According to another embodiment, a method is provided for cleaning a portion of a lithography apparatus using a cleaning tool. The method includes: inserting the cleaning tool into the lithography apparatus in a first configuration; engaging the cleaning tool with a tool handler of the lithography apparatus; moving the cleaning tool from the first configuration to an extended second configuration; and using the cleaning tool to clean the portion of the lithography apparatus. The cleaning tool is in the second configuration when used to clean the portion of the lithography apparatus.

[0031] In one embodiment, the method includes: containing the cleaning tool in the first configuration in a container and inserting the cleaning tool in the container into the lithography apparatus, removing the cleaning tool from the container using the tool handler for the cleaning, and returning the cleaning tool to the container using the tool handler after the cleaning.

[0032] In one embodiment, the cleaning tool is configured to move from the first configuration to the second configuration when the cleaning tool is removed from the container by the tool handler for cleaning.

[0033] In one embodiment, the cleaning tool is configured to move from the second configuration to the first configuration when the cleaning tool is returned to the container by means of the tool disposal after cleaning.

[0034] In one embodiment, the container includes one or more retractable components. The method includes: when the cleaning tool is returned to the container after cleaning, utilizing the retractable components to facilitate the retraction of the cleaning tool from the second configuration to the first configuration.

[0035] In one embodiment, the portion of the lithography apparatus includes a mask fixture for a mask stage.

[0036] In one embodiment, the cleaning tool includes a cleaning mask.

[0037] In one embodiment, the tool handler includes a turntable clamp for a mask handler.

[0038] In one embodiment, the lithography apparatus is configured for deep ultraviolet (DUV) radiation.

[0039] In one embodiment, the movement is facilitated by one or more links in the cleaning tool connected by hinged joints, the links being configured to facilitate expansion or contraction between the first and second configurations. In another embodiment, the movement is facilitated by one or more flexible portions of the cleaning tool, the flexible portions being configured to facilitate expansion or contraction between the first and second configurations. In yet another embodiment, the movement is facilitated by one or more rotating portions of the cleaning tool, the rotating portions being configured to facilitate expansion or contraction between the first and second configurations.

[0040] In one embodiment, the method includes: providing a cleaning surface on the cleaning tool, at least partially covered by a cleaning material; providing an identification surface on the cleaning tool, the identification surface being located on the opposite side of the cleaning tool relative to the cleaning surface; providing one or more identification features on the cleaning tool, the one or more identification features being located on one or more inner surfaces of the cleaning tool between the cleaning surface and the identification surface, the one or more identification features being visible through the identification surface; and providing an illumination source inside the cleaning tool, located between the cleaning surface and the identification surface, the illumination source being configured to provide illumination such that the one or more identification features are visible through the identification surface.

[0041] According to another embodiment, a computer program product is provided, the computer program product including a non-transitory computer-readable medium recording instructions that, when executed by a computer, perform any of the methods described above. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments, and explain these embodiments together with this specification. Embodiments of the invention will now be described with reference to the accompanying schematic drawings, which are merely examples, in which corresponding reference numerals indicate corresponding parts, and in the drawings:

[0043] Figure 1 A lithography apparatus according to an embodiment is schematically depicted.

[0044] Figure 2 An embodiment of a photolithography unit or cluster according to an embodiment is schematically depicted.

[0045] Figure 3A The description of the lithography apparatus according to the embodiments includes cleaning tools, cleaning tool containers, a turntable clamp for a mask disposal unit, a mask fixture for a mask stage, and / or other components.

[0046] Figure 3B According to the embodiments Figure 3A An enlarged view of a portion of the photolithography equipment shown in the image.

[0047] Figure 4 Description according to the embodiments Figure 3A The photolithography equipment includes the mask handler, the robot clamping part, the cleaning tool container, the cleaning tool (e.g., the mask), and / or other components.

[0048] Figure 5 This describes the clamping portion of the mask disposal robot clamp according to an embodiment in the absence of a cleaning tool container or cleaning tool.

[0049] Figure 6 This describes a turntable clamping device for clamping a mask holder of a cleaning tool in a contracted configuration within a cleaning tool container, according to an embodiment.

[0050] Figure 7 This describes a turntable clamp for a mask disposal unit that removes cleaning tools from a cleaning tool container according to an embodiment.

[0051] Figure 8 This illustration shows a side view of the support leg of the turntable clamp of a mask disposal unit for clamping a cleaning tool in a shrink configuration within a container, according to an embodiment.

[0052] Figure 9 The embodiment describes a turntable clamp of a mask disposal unit that moves the cleaning surface of a cleaning tool (in an extended configuration) into contact with a target surface, which includes one or more clamps, an associated diaphragm surface of a lithography apparatus, and / or other target surfaces for cleaning.

[0053] Figure 10 A top view illustrating the mask stage, mask fixture, and / or associated diaphragm according to an embodiment.

[0054] Figure 11 Examples illustrating cleaning tools (e.g., mask plates) according to embodiments.

[0055] Figure 12 This shows a view of the turntable clamp and its legs as seen through a cleaning tool (upwards) according to an embodiment.

[0056] Figure 13 This describes an exemplary embodiment of a layered version of a cleaning tool according to an embodiment, wherein the cleaning tool has an irradiation source located inside the cleaning tool between the cleaning surface and the identification surface of the cleaning tool.

[0057] Figure 14 This describes a method for cleaning a portion of a photolithography apparatus according to an embodiment.

[0058] Figure 15 This is a block diagram of an exemplary computer system according to an embodiment.

[0059] Figure 16 For embodiments similar to Figure 1 A schematic diagram of a photolithography projection device. Detailed Implementation

[0060] Typically, a mask or photomask can be a block of transparent material covered with a pattern defined by different opaque materials. Various masks are fed into a lithography apparatus and used to form layers of a semiconductor device. The pattern defined on a given mask or photomask corresponds to features generated in one or more layers of a semiconductor device. Multiple masks or photomasks are often automatically fed into a lithography apparatus during manufacturing and used to form corresponding layers of a semiconductor device. Fixtures in the lithography apparatus (e.g., mask holders on a mask stage) are used to hold the masks or photomasks during processing. These fixtures require periodic cleaning. Cleaning typically requires stopping the lithography apparatus and the manufacturing process. Cleaning is performed manually by a technician and can take several hours to complete.

[0061] Advantageously, this system and method provide a cleaning tool configured for in-situ cleaning of the fixtures and / or associated diaphragms of a lithography apparatus while the apparatus continues to operate. The fixture includes several components configured to support a chuck body and provide a connection to the chuck body. The diaphragm is the portion of the fixture that contacts the photomask. The cleaning tool is configured to be automatically inserted into and disposed of by the lithography apparatus, just as any other photomask or photomask is automatically inserted into and disposed of by the lithography apparatus. Cleaning the lithography apparatus using this cleaning tool saves hours of downtime associated with previous cleaning methods. Additionally, in some embodiments, the system is configured to prevent contamination of other parts of the lithography apparatus (e.g., photomask handler robot clamps) by material removed from the cleaning (photomask stage) fixture and / or its associated diaphragm, as described below.

[0062] In some embodiments, the cleaning tool includes a cleaning mask configured to have an internal illumination source. The illumination source is configured to illuminate an identification feature of the internal cleaning mask. The identification feature is used by a camera of the lithography apparatus to identify and track the position of the cleaning mask. Advantageously, the illumination source and the internal identification feature allow cleaning material to completely cover the cleaning surface of the cleaning mask without obscuring the identification feature relative to the camera. Additionally, the outer surface of the cleaning mask opposite the cleaning surface can remain smooth for clamping by the lithography apparatus.

[0063] While reference may be specifically made herein to the manufacture of integrated circuits (ICs), it should be understood that the descriptions herein have many other possible applications. For example, the descriptions herein can be used to manufacture integrated optical systems, guide and detect patterns for magnetic domain memories, liquid crystal display panels, thin-film magnetic heads, etc. Those skilled in the art will understand that, in the context of such alternative applications, any use of the terms “mask,” “wafer,” or “die” herein should be considered interchangeable with the more general terms “mask,” “substrate,” and “target portion,” respectively. Furthermore, any use of the terms “mask” or “die” herein may be considered synonymous with the more general term “patterning apparatus.”

[0064] As an introduction, Figure 1 An embodiment of a lithography apparatus LA that may be included in and / or associated with this system and / or method is schematically depicted. The apparatus includes: an irradiation system (irradiator) IL configured to modulate a radiation beam B (e.g., UV radiation, DUV radiation, or EUV radiation); a support structure (e.g., a mask stage) MT configured to support a patterning apparatus (e.g., a mask) MA and connected to a first positioner PM configured to accurately position the patterning apparatus according to certain parameters; a substrate stage (e.g., a wafer stage) WT (e.g., WTa, WTb, or both) configured to hold a substrate (e.g., a resist-coated wafer) W and coupled to a second positioner PW configured to accurately position the substrate according to certain parameters; and a projection system (e.g., a refractive projection lens system) PS configured to project a pattern imparted by the radiation beam B by the patterning apparatus MA onto a target portion C (e.g., comprising one or more dies and often referred to as a field) of the substrate W. The projection system is supported on a reference frame (RF).

[0065] As depicted, the device is of the transmissive type (e.g., using a transmissive mask). Alternatively, the device may be of the reflective type (e.g., using a programmable mirror array of the type mentioned above, or using a reflective mask).

[0066] The irradiator IL receives the radiation beam from the radiation source SO. For example, when the source is an excimer laser, the source and the lithography apparatus can be separate entities. In such cases, the source is not considered a component of the lithography apparatus, and the radiation beam is delivered from the source SO to the irradiator IL by means of a beam delivery system BD that includes, for example, suitable guide mirrors and / or beam expanders. In other cases, for example, when the source is a mercury lamp, the source can be an integral part of the apparatus. The source SO and the irradiator IL, together with the beam delivery system BD, can be referred to as the radiation system when necessary.

[0067] The illuminator IL can modify the intensity distribution of the beam. The illuminator can be configured to limit the radial range of the radiation beam such that the intensity distribution within an annular region in the pupil plane of the illuminator IL is non-zero. Alternatively, the illuminator IL can be operated to limit the beam distribution in the pupil plane such that the intensity distribution in multiple equally spaced segments within the pupil plane is non-zero. The intensity distribution of the radiation beam in the pupil plane of the illuminator IL can be referred to as the illumination mode.

[0068] An illuminator IL may include an adjuster AD configured to adjust the (angular / spatial) intensity distribution of a beam. Typically, at least the outer radial range and / or inner radial range (often referred to as σ_outer and σ_inner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. The illuminator IL is operable to change the angular distribution of the beam. For example, the illuminator is operable to change the number and angular range of segments in the pupil plane where the intensity distribution is non-zero. Different illumination modes can be achieved by adjusting the intensity distribution of the beam in the pupil plane of the illuminator. For example, by limiting the radial and angular ranges of the intensity distribution in the pupil plane of the illuminator IL, the intensity distribution can have a multi-pole distribution, such as (e.g.) a dipole, tetrapole, or hexapole distribution. The desired illumination mode can be obtained, for example, by inserting optics providing the illumination mode into the illuminator IL or by using a spatial light modulator.

[0069] The illuminator IL is operable to change the polarization of the beam and is operable to adjust the polarization using an adjuster AD. The polarization state of the radiation beam passing through the pupil plane of the illuminator IL can be referred to as the polarization mode. Using different polarization modes can allow for greater contrast in an image formed on the substrate W. The radiation beam can be unpolarized. Alternatively, the illuminator can be configured to linearly polarize the radiation beam. The polarization direction of the radiation beam can vary across the entire pupil plane of the illuminator IL. The polarization direction of the radiation can be different in different regions of the pupil plane of the illuminator IL. The polarization state of the radiation can be selected depending on the illumination mode. For a multi-pole illumination mode, the polarization of each pole of the radiation beam can be substantially perpendicular to the position vector of the pole in the pupil plane of the illuminator IL. For example, for a dipole illumination mode, the radiation can be linearly polarized in a direction substantially perpendicular to the line bisecting the two opposing segments of the dipole. The radiation beam can be polarized in one of two different orthogonal directions, which can be referred to as the X-polarization state and the Y-polarization state. For a quadrupole illumination mode, the radiation in each pole segment can be linearly polarized in a direction substantially perpendicular to the line that bisects the segment. This polarization mode can be called XY polarization. Similarly, for a hexapole illumination mode, the radiation in each pole segment can be linearly polarized in a direction substantially perpendicular to the line that bisects the segment. This polarization mode can be called TE polarization.

[0070] In addition, the irradiator IL typically includes various other components, such as a beam concentrator IN and a condenser CO. The irradiation system may include various types of optical components for guiding, shaping, or controlling radiation, including refractive, reflective, magnetic, electromagnetic, electrostatic, or other types of optical components or any combination thereof. Therefore, the irradiator provides a modulated radiation beam B with a desired uniformity and intensity distribution in its cross-section.

[0071] The support structure MT supports the patterning apparatus in a manner dependent on the orientation of the patterning apparatus, the design of the lithography equipment, and other conditions, such as whether the patterning apparatus is held in a vacuum environment. The support structure can use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning apparatus. The support structure can be, for example, a frame or stage, which can be fixed or movable as needed. The support structure ensures that the patterning apparatus is, for example, in the desired position relative to a projection system.

[0072] The term "patterning apparatus" as used herein should be broadly interpreted to refer to any apparatus that can be used to impart a pattern to a target portion of a substrate. In embodiments, a patterning apparatus is any apparatus that can be used to impart a pattern to a radiation beam in the cross-section of the radiation beam to produce a pattern in the target portion of the substrate. It should be noted that, for example, if the pattern imparted to the radiation beam includes phase-shifting features or so-called auxiliary features, the pattern may not precisely correspond to the desired pattern in the target portion of the substrate. Typically, the pattern imparted to the radiation beam will correspond to a specific functional layer in the device (such as an integrated circuit) produced in the target portion of the device.

[0073] Pattern forming apparatuses can be transmissive or reflective. Examples of pattern forming apparatuses include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in photolithography and include mask types such as binary, alternating phase-shift, and attenuation phase-shift masks, as well as various hybrid mask types. Examples of programmable mirror arrays use a matrix configuration of small mirrors, each of which can be individually tilted to reflect an incident radiation beam in different directions. The tilted mirrors impart a pattern to the radiation beam reflected by the mirror matrix.

[0074] The term “projection system” as used herein should be interpreted broadly to encompass any type of projection system suitable for the exposure radiation used or for other factors such as immersion in liquids or vacuum, including refractive, reflective, reflective-refractive, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof. Any use of the term “projection lens” herein may be considered synonymous with the more general term “projection system.”

[0075] The projection system PS has optical transfer capabilities that may be non-uniform and affect the pattern imaged on the substrate W. For unpolarized radiation, these effects can be described fairly well by two scalar maps that describe the transmission (apodization) and relative phase (aberration) of the radiation, varying depending on its position in the pupil plane of the radiation exiting the projection system PS. These scalar maps, which may be called transmission maps and relative phase maps, can be expressed as a linear combination of the complete set of basis functions. A suitable set is a set of Zernike polynomials that form a set of orthogonal polynomials defined on the unit circle. Determining each scalar map may involve determining the coefficients in this expansion. Since the Zernike polynomials are orthogonal on the unit circle, the Zernike coefficients can be determined by successively calculating the inner product of the measured scalar map with each Zernike polynomial and dividing this inner product by the square of the norm of the Zernike polynomial.

[0076] The transmission map and the relative phase map are field- and system-dependent. That is, typically, each projection system PS will have a different Zernike expansion for each field point (i.e., for each spatial location in the image plane of the projection system PS). The relative phase of the projection system PS in its pupil plane can be determined by projecting radiation from a point-like source in, for example, the object plane of the projection system PS (i.e., the plane of the pattern forming device MA) through the projection system PS and measuring the wavefront (i.e., the trajectory of points with the same phase) using a shearing interferometer. The shearing interferometer is a common-path interferometer, and therefore, advantageously, no secondary reference beam is required to measure the wavefront. The shearing interferometer may include: a diffraction grating, such as a two-dimensional grating in the image plane of the projection system (i.e., the substrate stage WTa or WTB); and a detector configured to detect an interference pattern in a plane conjugate to the pupil plane of the projection system PS. The interference pattern is related to the derivative of the phase of the radiation with respect to its coordinates in the pupil plane in the shear direction. The detector may include an array of sensing elements, such as, for example, a charge-connected device (CCD).

[0077] The projection system (PS) of a photolithography apparatus may not produce visible fringes, and therefore, phase-stepping techniques (such as, for example, moving a diffraction grating) can be used to enhance the accuracy of wavefront determination. Stepping can be performed in the plane of the diffraction grating and in a direction perpendicular to the scanning direction of the measurement. The stepping range can be one grating period, and at least three (uniformly distributed) phase steps can be used. Thus, for example, three scan measurements can be performed in the y-direction, and each scan measurement can be performed in the x-direction for different positions. This stepping of the diffraction grating effectively transforms phase changes into intensity changes, thereby allowing phase information to be determined. The grating can be stepped in a direction perpendicular to the diffraction grating (z-direction) to calibrate the detector.

[0078] The diffraction grating can be scanned sequentially in two perpendicular directions, which can coincide with the axes (x and y) of the coordinate system of the projection system PS, or can be at an angle to these axes, such as 45 degrees. Scanning can be performed over an integer number of grating periods (e.g., one grating period). The scan averages the phase change in one direction, thus allowing reconstruction of the phase change in the other direction. This allows wavefront determination based on both directions.

[0079] The transmission (apodization) of the projection system PS in the pupil plane of the projection system can be determined by projecting radiation from a point-like source in the object plane (i.e., the plane of the pattern forming apparatus MA) through the projection system PS and using a detector to measure the radiation intensity in a plane conjugate to the pupil plane of the projection system PS. The same detector used to measure the wavefront to determine aberrations can be employed.

[0080] A projection system PS may include multiple optical (e.g., lens) components and may also include an adjustment mechanism configured to adjust one or more of the optical components to correct for aberrations (phase changes across the entire pupil plane of the field). To achieve this adjustment, the adjustment mechanism can operate to manipulate one or more optical (e.g., lens) components within the projection system PS in one or more different ways. The projection system may have a coordinate system in which the optical axis of the projection system extends in the z-direction. The adjustment mechanism can operate to perform any combination of: displacing one or more optical components; tilting one or more optical components; and / or deforming one or more optical components. Displacement of the optical components can be performed in any direction (x, y, z, or a combination thereof). Tilt of the optical components is typically performed outside a plane perpendicular to the optical axis by rotation about an axis in the x and / or y directions, but for non-rotationally symmetric aspherical optical components, rotation about the z-axis may be used. Deformation of the optical components may include low-frequency shapes (e.g., astigmatism) and / or high-frequency shapes (e.g., free-form aspherical shapes). Deformation of an optical element can be performed, for example, by using one or more actuators to apply force to one or more sides of the optical element and / or by using one or more heating elements to heat one or more selected areas of the optical element. Typically, it is not possible to adjust the projection system PS to correct apodization (transmission variation across the entire pupil plane). The transmission map of the projection system PS can be used when designing a patterning apparatus (e.g., a mask) MA for a lithography device LA. Using computational lithography, the patterning apparatus MA can be designed to at least partially correct apodization.

[0081] Photolithography equipment can belong to the type having two (dual-platform) or more stages (e.g., two or more substrate stages WTa, WTb, two or more patterning apparatus stages, substrate stages WTa and WTb below the projection system in the absence of a substrate dedicated to (e.g.) facilitating measurement and / or cleaning, etc.). In these “multi-platform” machines, additional stages can be used in parallel, or preparatory steps can be performed on one or more stages while one or more other stages are used for exposure. For example, alignment measurements using an alignment sensor AS and / or level (height, tilt, etc.) measurements using a level sensor LS can be performed.

[0082] Photolithography apparatuses can also fall into the category where at least a portion of the substrate can be covered by a liquid (e.g., water) with a relatively high refractive index to fill the space between the projection system and the substrate. Immersion liquids can also be applied to other spaces within the photolithography apparatus, such as the space between the patterning apparatus and the projection system. Immersion techniques are well-known in the art for increasing the numerical aperture of projection systems. The term "immersion" as used herein does not mean that a structure such as the substrate must be submerged in a liquid, but only that the liquid is located between the projection system and the substrate during exposure.

[0083] In the operation of a photolithography apparatus, a radiation beam is modulated and provided by an irradiation system IL. The radiation beam B is incident on a patterning apparatus (e.g., a mask) MA held on a support structure (e.g., a mask stage) MT, and a pattern is formed by this apparatus. Having traversed the patterning apparatus MA, the radiation beam B is passed through a projection system PS, which focuses the beam onto a target portion C of the substrate W. The substrate stage WT can be accurately moved, for example, to position different target portions C within the path of the radiation beam B, by means of a second positioner PW and a position sensor IF (e.g., an interferometer, a linear encoder, a 2D encoder, or a capacitive sensor). Similarly, a first positioner PM and another position sensor (the other position sensor is not in...) Figure 1(As explicitly described in the text) can be used to accurately position the patterning apparatus MA relative to the path of the radiation beam B, for example, after mechanical acquisition from the mask library or during scanning. Typically, the movement of the support structure MT can be achieved by means of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning) forming part of the first positioner PM. Similarly, the movement of the substrate stage WT can be achieved using a long-stroke module and a short-stroke module forming part of the second positioner PW. In the case of a stepper (relative to the scanner), the support structure MT may be connected only to the short-stroke actuator, or it may be fixed. The patterning apparatus MA and the substrate W can be aligned using patterning apparatus alignment marks M1, M2 and substrate alignment marks P1, P2. Although the substrate alignment marks, as illustrated, occupy dedicated target portions, they can be located in the space between the target portions (these marks are referred to as scribing alignment marks). Similarly, in cases where more than one die is provided on the patterning apparatus MA, the patterning apparatus alignment marks can be located between the dies.

[0084] The described apparatus can be used in at least one of the following modes: 1. In a stepping mode, the support structure MT and substrate stage WT are kept substantially stationary while a pattern to be applied to the target portion C is projected onto it once (i.e., single static exposure). The substrate stage WT is then shifted in the X and / or Y directions, allowing different target portions C to be exposed. In the stepping mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure. 2. In a scanning mode, the support structure MT and substrate stage WT are scanned synchronously while a pattern to be applied to the target portion C is projected onto it (i.e., single dynamic exposure). The speed and direction of the substrate stage WT relative to the support structure MT can be determined by the magnification (reduction) and image flipping characteristics of the projection system PS. In the scanning mode, the maximum size of the exposure field limits the width of the target portion in a single dynamic exposure (in the non-scanning direction), while the length of the scanning motion determines the height of the target portion (in the scanning direction). 3. In another mode, the support structure MT is kept substantially stationary while the pattern to be irradiated is projected onto the target portion C, thereby holding the programmable patterning apparatus in place, and the substrate stage WT is moved or scanned. In this mode, a pulsed radiation source is typically used, and the programmable patterning apparatus is updated as needed after each movement of the substrate stage WT or between successive radiation pulses during scanning. This mode of operation can be readily applied to maskless lithography utilizing programmable patterning apparatuses such as programmable mirror arrays of the type mentioned above.

[0085] You may also use combinations and / or variations or completely different use patterns of the use patterns described above.

[0086] The substrates mentioned herein can be processed before or after exposure in, for example, in a track or coating development system (typically a tool that applies a resist layer to the substrate and develops the exposed resist) or in a measurement or inspection tool. Where applicable, the disclosure herein can be applied to such and other substrate processing tools. Additionally, the substrate can be processed more than once, for example to produce a multilayer IC, such that the term "substrate" as used herein may also refer to a substrate that already includes multiple processed layers.

[0087] The terms “radiation” and “beam” as used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) or deep ultraviolet (DUV) radiation (e.g., with wavelengths of 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm) and extreme ultraviolet (EUV) radiation (e.g., with wavelengths in the range of 5 nm to 20 nm), as well as particle beams, such as ion beams or electron beams.

[0088] Various patterns on or provided by a pattern forming apparatus may have different process windows, i.e., the space of processing variables upon which a pattern conforming to specifications is based. Examples of pattern specifications for potential systematic defects include checking for necking, line pullback, line thinning, CD, edge placement, overlap, resist top loss, resist undercut, and / or bridging. The process windows of a pattern or its region can be obtained by merging the process windows of each individual pattern on or in a region of the pattern forming apparatus (e.g., by overlapping the process windows). The boundaries of the process windows of a group of patterns include the boundaries of the process windows of some of the individual patterns. In other words, these individual patterns limit the process windows of the group of patterns. These patterns may be referred to as “hot spots” or “process window limited patterns (PWLP)”, which are used interchangeably herein. When controlling a portion of the pattern forming process, it is possible and economical to focus on hot spots. When a hot spot is defect-free, it is most likely that the other patterns are also defect-free.

[0089] like Figure 2As shown, the lithography apparatus LA can form part of a lithography unit LC (sometimes also called a lithocell or cluster), which also includes equipment for performing pre-exposure and post-exposure processes on the substrate. Typically, these devices include one or more spin coaters SC for depositing one or more resist layers, one or more developers for developing the exposed resist, one or more chillers CH, and / or one or more baking plates BK. A substrate handler or robot RO picks up one or more substrates from input / output ports I / O1, I / O2, moves the substrates between different process units, and transfers them to the lithography apparatus's loading stage LB. These devices, often collectively referred to as tracks, are controlled by a track control unit TCU, which in turn is controlled by a management control system SCS, which in turn controls the lithography apparatus via the lithography control unit LACU. Therefore, different devices can be operated to maximize throughput and processing efficiency.

[0090] To ensure correct and consistent exposure of a substrate exposed by a lithography apparatus and / or to monitor a patterning process (e.g., a device fabrication process) that includes at least one pattern transfer step (e.g., an optical lithography step), it is necessary to detect the substrate or other objects to measure or determine one or more characteristics, such as alignment, overlap (alignment, overlap can be, for example, between structures in an overlay or between structures in the same layer that have been separately provided to that layer, for example, through a dual patterning process), line thickness, critical dimension (CD), focus offset, material properties, etc. For example, contaminants on a mask fixture (e.g., as described herein) can adversely affect overlap because holding the mask on such contaminants will distort the mask. Therefore, fabrication facilities with lithography units LC typically also include a measurement system that measures the substrate W (which has been processed in the lithography unit) Figure 1 The measurement system can be some or all of the objects in the lithography unit (LC), or other objects in the lithography apparatus (LA). For example, the measurement system can be part of the lithography unit (LA) (such as the alignment sensor AS). Figure 1 )).

[0091] For example, one or more measured parameters may include: alignment or overlap between successive layers formed in or on a patterned substrate; (e.g.,) the critical dimension (CD) (e.g., critical linewidth) of a feature formed in or on a patterned substrate; focusing or focusing error of an optical lithography step; dose or dose error of an optical lithography step; optical aberration of an optical lithography step; etc. This measurement can be performed on a target of the product substrate itself and / or on a dedicated measurement target provided on the substrate. Measurements can be performed after resist development but before etching, after etching, after deposition, and / or at other times.

[0092] Various techniques exist for measuring structures formed during patterning, including the use of scanning electron microscopes, image-based measurement tools, and / or various specialized tools. As discussed above, a rapid and non-invasive form of specialized measurement tool is one where a radiation beam is directed onto a target on the surface of a substrate and the characteristics of the scattered (diffracted / reflected) beam are measured. By evaluating one or more characteristics of the radiation scattered by the substrate, one or more properties of the substrate can be determined. This can be referred to as diffraction-based measurement. One such application of diffraction-based measurement is in the measurement of characteristic asymmetries within a target. While this measurement of characteristic asymmetries can be used, for example, as a measure of overlap, other applications are also known. For example, asymmetry can be measured by comparing opposite portions of the diffraction spectrum (e.g., comparing the -1st order with the +1st order in the diffraction spectrum of a periodic grating). This measurement can be performed as described above and as described, for example, in U.S. Patent Application Publication US2006-066855, which is incorporated herein by reference in its entirety. Another application of diffraction-based measurements is in the measurement of the feature width (CD) within a target.

[0093] Therefore, during device fabrication processes (e.g., patterning processes, photolithography processes, etc.), substrates or other objects can be subjected to various types of measurements during or after the process. Measurements can determine whether a particular substrate has defects, establish adjustments to the process and the equipment used in the process (e.g., aligning two layers on a substrate or aligning a patterning apparatus to a substrate), measure the performance of the process and equipment, or be used for other purposes. Examples of measurements include optical imaging (e.g., optical microscopy), non-imaging optical metrology (e.g., diffraction-based measurements, such as the ASML YieldStar metrology tool and the ASML SMASH metrology system), mechanical measurements (e.g., profilometry using a stylus, atomic force microscopy (AFM)), and / or non-optical imaging (e.g., scanning electron microscopy (SEM)). The SMASH (Smart Hybrid Alignment Sensor) system described in U.S. Patent No. 6,961,116, which is incorporated herein by reference in its entirety, uses a self-reference interferometer that generates two overlapping and relatively rotated images of an alignment marker, detects the intensity in a pupil plane that interferes with the Fourier transforms of the images, and extracts position information from the phase difference between the diffraction orders of the two images, which is represented by an intensity variation in the interference order.

[0094] Measurement results can be provided directly or indirectly to the management and control system (SCS). If an error is detected, adjustments can be made to the exposure of subsequent substrates (especially where detection can be completed quickly enough that one or more other substrates in the batch are still awaiting exposure) and / or to the subsequent exposure of already exposed substrates. Furthermore, already exposed substrates can be stripped and reworked to improve yield, or discarded, thereby avoiding further processing of known defective substrates. In cases where only some target portions of the substrate are defective, further exposure can be performed only on those target portions that meet specifications.

[0095] Within a metrology system (MET), metrology equipment is used to determine one or more properties of a substrate, and in particular, how one or more properties vary between different substrates or between different layers of the same substrate. As mentioned above, metrology equipment can be integrated into a lithography apparatus (LA) or a lithography unit (LC), or it can be a separate device.

[0096] To enable measurement, one or more targets can be provided on the substrate. In embodiments, the targets are specifically designed and may include periodic structures. In embodiments, the targets are part of a device pattern, such as a periodic structure of the device pattern. In embodiments, the device pattern is a periodic structure of a memory device (e.g., a bipolar transistor (BPT), bit line junction (BLC), or similar structure).

[0097] In one embodiment, the target on the substrate may include one or more one-dimensional periodic structures (e.g., gratings) printed such that, after development, periodic structural features are formed by solid resist lines. In another embodiment, the target may include one or more two-dimensional periodic structures (e.g., gratings) printed such that, after development, the one or more periodic structures are formed by solid resist pillars or vias in the resist. Alternatively, the gratings, pillars, or vias may be etched into the substrate (e.g., etched into one or more layers on the substrate).

[0098] In an embodiment, one of the parameters of interest in the patterning process is overlap. Overlap can be measured using dark-field scattering, where zero-order diffraction (corresponding to specular reflection) is blocked, and only higher orders are processed. Examples of dark-field measurements can be found in PCT patent applications WO2009 / 078708 and WO2009 / 106279, the full text of which is incorporated herein by reference. Further developments of this technique have been described in U.S. patent applications US2011-0027704, US2011-0043791, and US2012-0242970, the full text of which is incorporated herein by reference. Diffraction-based overlap detection using dark-field diffraction order enables overlap measurement of small targets. These targets can be smaller than the illumination spot and can be surrounded by a device product structure on a substrate. In an embodiment, multiple targets can be measured in a single radiation capture.

[0099] As lithography nodes continue to shrink, increasingly complex wafer designs can be implemented. Designers can use a variety of tools and / or techniques to ensure that complex designs are accurately transferred to the physical wafer. These tools and techniques can include mask optimization, source mask optimization (SMO), OPC, design and / or other tools and / or techniques for control. For example, the source mask optimization process is described in U.S. Patent No. 9,588,438, entitled “Optimization Flows of Source, Mask and Projection Optics,” which is incorporated herein by reference in its entirety.

[0100] This system and / or method can be used as a standalone tool and / or technique, and / or in combination with other semiconductor manufacturing processes to enhance the accurate transfer of complex designs to physical wafers.

[0101] As described above, this system includes a cleaning tool configured to clean a portion of the lithography apparatus in situ while the lithography apparatus continues to operate. For example, the cleaning tool may replace only a typical mask inserted into the lithography apparatus. The lithography apparatus can move the cleaning tool by the typical movement and / or position of the replaced mask, so that the lithography apparatus does not require special adjustments to the cleaning tool during operation. In some embodiments, the portion of the lithography apparatus to be cleaned includes the mask holder of the mask stage, the associated diaphragm, and / or other parts of the lithography apparatus. The cleaning tool is configured to be automatically inserted into and disposed of by the lithography apparatus (e.g., moved, rotated, etc.), just as any other mask or mask is automatically inserted into and disposed of by the lithography apparatus. Cleaning the lithography apparatus using this cleaning tool saves hours of downtime associated with previous cleaning methods. Additionally, this system is configured to prevent contamination of other parts of the lithography apparatus (e.g., the mask handler robot clamp) by material removed from the cleaning (mask stage mask) holder, as described below. A cleaning tool is configured to be inserted into the lithography apparatus in a first, contracted configuration within a container, engaged by the tool handler of the lithography apparatus, and used to clean said portion of the lithography apparatus. The cleaning tool is configured to move from the contracted configuration to an expanded second configuration outside the container after engagement by the tool handler, such that the cleaning tool is in the second configuration when used to clean said portion of the lithography apparatus.

[0102] In some embodiments, the system includes cleaning tools, a container configured to hold the cleaning tools, and / or other components. As a non-limiting example, Figure 3A and Figure 3B Describe the photolithography equipment 300 (e.g., similar to or the same as) Figure 1 (Part of the lithography equipment shown in the image). Figure 3A The description includes the system 301 comprising cleaning tool 302 and cleaning tool container 304 and / or other components; and the lithography apparatus 300 comprising tool handlers 306, 307, 308, mask stage 310, and mask fixture 312 (only one side of which is in the photolithography apparatus 300). Figure 3AVarious components (visible in the image), and / or other components. In some embodiments, the lithography apparatus 300 is configured for deep ultraviolet (DUV) lithography. In some embodiments, the cleaning tool 302 includes cleaning a mask and / or other components. In some embodiments, tool handlers 306, 307, 308 include a turntable clamp 306 for a mask handler, a robot clamp 307 for a mask handler (with associated fixtures 308 for clamping the mask), and / or other components. The robot clamp 307 for a mask handler can, for example, remove the mask from the compartment 320 (e.g., after a user has placed the mask in the compartment 320). For example, the turntable clamp 306 for a mask handler can move the mask from the robot clamp 307 to the mask fixture 312. The lithography equipment 300 may include various other mechanical components 322 (translation mechanism, lifting mechanism, rotation mechanism, motor, power generator and transmission components, structural components, etc.) configured to facilitate the movement and control of the cleaning tool 302 and / or cleaning tool container 304 through the lithography equipment 300.

[0103] The cleaning tool 302 is configured to clean the clamp 312 and / or associated diaphragm (e.g., the diaphragm of the clamp that contacts the bottom surface of the photomask) of the photolithography apparatus 300 in situ while the photolithography apparatus 300 continues to operate. The container 304 is configured to hold the cleaning tool 302. The cleaning tool 302 and container 304 are configured to be automatically inserted into and disposed of by the photolithography apparatus 300, just as any other mask or photomask 316 is automatically inserted into and disposed of by the photolithography apparatus 300. For example, the cleaning tool 302 and / or the cleaning tool container 304 are sized and shaped to be inserted into the photolithography apparatus 300 at a typical insertion point 318 using a typical insertion method, just as any other photomask 316 would be inserted into the apparatus 300.

[0104] Figure 3B An enlarged view of a portion of device 300. Figure 3B The following components are shown: cleaning tool 302, cleaning tool container 304, turntable clamp 306 for mask holder, mask table 310, and mask fixture 312 for the mask table (only one side is shown). Figure 3B (See in the image), mechanical component 322, mask processor robot clamp 307 and / or other components. For example... Figure 3BAs shown, the turntable clamp 306 of the mask processor is configured to move the cleaning tool 302 and / or container 304 from the mask processor robot clamp 307 to the mask fixture 312 on the mask table 310, thus allowing the cleaning tool 302 to be used to clean the fixture 312 in situ. Moving the cleaning tool 302 may include moving the cleaning tool toward or away from the fixture 312 in horizontal, vertical, and / or other directions. The turntable clamp 306 and / or the mask processor robot clamp 307 may include various motors, translators, rotating components, clamps, grippers, power supplies, power transmission components, vacuum mechanisms, and / or other components that facilitate the movement of the cleaning tool 302 and / or container 304.

[0105] Due to volume constraints within the mask handler robot clamp 307 and the dimensions of the cleaning surface required for the mask fixture 312 on the mask stage 310, the cleaning tool 302 is configured with an extended cleaning configuration that is larger than the internal volume and / or external periphery of the container 304. For example, a typical mask is mounted between fixtures 312 and also within the clamping portion of the mask handler robot clamp 307 and the turntable clamp 306. However, the cleaning tool 302, which needs to be mounted within the clamping portions of fixtures 306 and 307 for processing by the lithography apparatus 300, also needs to cover at least a portion of the fixtures 312 (rather than being mounted between them) for cleaning.

[0106] The cleaning tool 302 is configured to have a (first) retractable configuration, allowing it to be stored in container 304 (and moved through device 300 like any other mask). The cleaning tool 302 is configured to be removed from container 304 for cleaning by turntable clamp 306 of the mask handler. Once removed from container 304 by turntable clamp 306 of the mask handler, the cleaning tool 302 is configured to move to a (second) extended configuration having dimensions suitable for the cleaning process. In other words, the cleaning tool 302 is configured to move from the first configuration to the second configuration as it is removed from container 304 for cleaning by clamp 306 (part of the tool handler). The cleaning tool 302 is configured to return to the retractable configuration within container 304 for storage in and / or removal from lithography device 300 by mask handler robot clamp 307. Container 304 is held in the mask disposal robot clamp 307 during cleaning. Cleaning tool 302 is configured to be returned to container 304 by turntable clamp 306 of the mask disposal after cleaning. In other words, cleaning tool 302 is configured to move from a second configuration to a first configuration when cleaning tool 302 is returned to container 304 by clamp 306 (another part of the tool disposal) after cleaning.

[0107] Figure 4 This describes the clamping portion 400 of the mask disposal robot clamp 307, the cleaning tool container 304, the cleaning tool (e.g., a mask) 302, and / or other components. As described above, the mask disposal robot clamp 307 is configured to allow the user to place the container 304 containing the cleaning tool 302 (or another mask) into the compartment 320. Figure 3A Afterwards, the container 304 containing the cleaning tool 302 is moved from the compartment 320 to the turntable clamp 306 of the mask plate handler. Figure 3A , Figure 3B The clamping portion 400 includes a clamp 308 for clamping the container 304. The container 304 is configured to receive the cleaning tool 302 when it is in a (first) retracted configuration and is fitted to the photolithography apparatus 300. Figure 3A , Figure 3B (in the compartment). In Figure 4 In the image, the cleaning tool 302 is shown in a retracted configuration within the container 304. With the cleaning tool 302 in this retracted configuration within the container 304, the cleaning tool 302 can be moved through the photolithography apparatus 300 like any other photomask. Figure 3A , Figure 3B The cleaning tool 302 is configured to be inserted into the lithography apparatus 300 in the container 304, removed from the container 304 by the tool handler (rotary table clamp) 306 for cleaning, and returned to the container 304 by the tool handler (rotary table clamp) 306 after cleaning.

[0108] Figure 5 Instructions for use in containers without cleaning tools (e.g., Figure 4 304 shown in the image) or cleaning tools (e.g., Figure 4 The mask holder robot clamp in case 302 shown in the figure (e.g., Figure 3A and Figure 3B Two views 500 and 502 of the clamping portion 400 of the mask holder 307 are shown. View 502 is a rotated 505 view of an arm 506 of the clamping portion 400 (for providing an enhanced view of the inner edge of the arm 506). Views 500 and 502 illustrate the banking surface 510 of the clamping portion 400. The banking surface 510 may be a surface configured to contact the clamping portion 400 of the container 304 and / or other mask. The cleaning tool container 304 is configured to protect the banking surface 510 of the clamping portion 400 of the mask disposal robot clamp 307 from contact with the cleaning surface of the cleaning tool (e.g., mask) 302. System 301 ( Figure 3A , Figure 3B and Figure 4The mask disposal robot gripper 307 is configured such that the limiting surface 510 of the gripping portion 400 contacts the outer surface of the container 304. When the cleaning tool 302 returns to the container 304 after cleaning, any contaminants picked up by the cleaning tool 302 are retained within the container 304 and do not spread to the device 300. Figure 3A and Figure 3B This includes other parts of the limiting surface 510. This reduces and / or substantially eliminates other (e.g., customer) mask contamination and / or recontamination of the mask stage 310 in the device 300. Figure 3A ), Fixture 312 ( Figure 3B The possibility of ) and / or other components.

[0109] Return to Figure 4 In some embodiments, the cleaning tool 302 includes one or more tool handler engagement surfaces 402 and / or other components. The engagement surfaces 402 are configured to remain in a position and orientation corresponding to a tool handler (e.g., clamp 306) regardless of whether the cleaning tool 302 is in a retracted (e.g., first) configuration or an extended (e.g., second) configuration. In some embodiments, the cleaning tool 302 includes one or more cleaning portions 404 having cleaning surfaces (below or on the bottom side of the portion 404) Figure 4 (Not visible in the image). The cleaning portion 404 and / or the cleaning surface are configured to move relative to the tool handler engagement surface 402 as the cleaning tool 302 moves between a contracted (e.g., first) configuration and an extended (e.g., second) configuration. In some embodiments, this movement may be relative rotation and / or other movements. In some embodiments, the cleaning surface is configured to contact one or more target surfaces of the portion of the lithography apparatus (e.g., ...) when the cleaning tool 302 is in the extended configuration. Figure 3A and Figure 3B The fixture 312 and / or associated diaphragm shown are used for cleaning. In some embodiments, the cleaning surface is configured to be parallel to one or more target surfaces when the cleaning tool 302 is in an extended configuration. In some embodiments, one or more target surfaces include one or more fixtures 312, the associated diaphragm surface of the lithography apparatus, and / or other target surfaces.

[0110] Figure 6 and Figure 7 Further explanation is provided. Figure 6 The rotary table clamp 306 of the mask holder for clamping the cleaning tool 302 (in a retracted configuration) in the clamping container 304. Figure 7The rotary table clamp 306 of the mask disposal unit is described as removing cleaning tool 302 from container 304. In response to removal from container 304, cleaning tool 302 has expanded to an expanded configuration. Engaging surface 402 is configured to operate regardless of whether cleaning tool 302 is in a retracted position (e.g., as...). Figure 6 (as shown) configuration or extension (e.g., as shown) Figure 7 The configuration (shown) is maintained in position and orientation corresponding to the clamping legs 600 of the clamp 306. In this example, the surfaces 402 are maintained at a fixed distance from each other corresponding to the distance between the legs 600. The surfaces 402 are also maintained perpendicular to the legs 600 to facilitate clamping by the legs 600. The cleaning portion 404 has a cleaning surface 700 (on the underside or bottom side of the portion 404—as shown). Figure 7 (As shown in the diagram). The cleaning portion 404 and / or the cleaning surface 700 are configured such that when the cleaning tool 302 retracts (e.g., Figure 6 Configuration and extensions (e.g., Figure 7 When moving between configurations, it moves relative to the tool handler engagement surface 402 (see From) Figures 6 to 7 (transformation). In some embodiments, the cleaning surface 700 may be attached to a larger mask structure (e.g., by coating, bonding, and / or other operations). In some embodiments, the cleaning surface 700 may be a removable and / or replaceable separate component. In some embodiments, the cleaning surface 700 is configured when the cleaning tool 302 is in an extended configuration ( Figure 7 ) parallel to the photolithography equipment 300 ( Figure 3A and Figure 3B One or more target surfaces.

[0111] In some embodiments, such as Figure 7 As shown, the cleaning tool 302 may include an elastomer 731 and / or other materials at or near the corners of the cleaning tool 302. The elastomer 731 may be an elastic / damping material coupled to the cleaning tool 302. The elastomer 731 may restrict the movement of the cleaning tool 302 during cleaning, cushion the impact of the cleaning tool 302 using a mask buffer, a portion of the turntable clamp 306 of the mask handler, a portion of the container 304, and / or serve other purposes.

[0112] Figure 8 This is a side view of the support leg 600 of the turntable clamp 306 of the mask holder for clamping the cleaning tool 302 (in a retracted configuration) in the container 304. When the cleaning tool 302 is removed from the container 304, the cleaning tool 302 expands such that the size 820 of the cleaning tool 302 expands 822 beyond the perimeter 824 of the container 304. Figure 9The description refers to the turntable clamp 306 of a mask handler that moves the cleaning surface 700 of a cleaning tool 302 (in an extended configuration) into contact with a target surface, which includes one or more clamps 312, an associated diaphragm surface of a lithography apparatus, and / or other target surfaces for cleaning. Figure 9 As shown, the cleaning tool 302 can be generally parallel to the clamp 312 when it is in contact with the clamp 312 for cleaning. When in contact with the clamp 312 for cleaning, the mass and / or other forces of the clamp 306 can help keep the cleaning tool 302 in contact with the clamp 312.

[0113] In some embodiments, such as Figure 8 and Figure 9 As shown, the cleaning tool 302 includes one or more links 800 connected by a hinge joint 802, which are configured to facilitate expansion or contraction between a first (contracted) configuration and a second (expanded) configuration. In some embodiments, the cleaning tool 302 includes one or more flexible portions configured to facilitate expansion or contraction between the first and second configurations. In some embodiments, the cleaning tool 302 includes one or more rotating portions configured to facilitate expansion or contraction between the first and second configurations. Other embodiments are contemplated. These embodiments can achieve any type of expansion, contraction, deformation, flexure, shape change, and / or other movement, as described herein, allowing the cleaning tool 302 to move from its dimensions assembled into the container 304 to dimensions suitable for the cleaning mask stage 310, mask fixture 312, and / or associated diaphragm. When the cleaning tool 302 is removed from the container 304 ( Figure 8 When moving, for example, gravity, springs, magnets and / or other mechanisms that cause movement included in or acting on the cleaning tool 302 may move the cleaning tool 302 from a retracted configuration to an extended configuration.

[0114] Figure 10Top views 1050, 1060, and 1070 illustrate the mask stage 310, mask fixture 312, and / or associated diaphragm 1052. In some embodiments, for example, fixture 312 and / or associated diaphragm 1052 may be target surfaces cleaned by cleaning tool 302. Typically, diaphragm 1052 contacts the bottom of the mask in the area where barcodes (and / or other identification data) are printed. Printing is applied using chromium, MoSi, or other materials. When the mask is clamped via vacuum and then scanned (e.g., for identification purposes), the higher contact pressure can initiate molecular-level bonding between the mask material and the fixture 312 material. Upon separation, a smaller portion of the mask material is pulled out and remains on the surface of diaphragm 1052. Therefore, cleaning is required. In practice, the turntable clamp 306 of the mask handler ( Figure 10 (Not shown in the image) This will lower (e.g., to the page) the cleaning tool (mask) 302 in its extended form onto the clamp 312 and / or the associated diaphragm 1052.

[0115] View 1060 is an enlarged view of a portion of View 1050. Views 1050 and 1060 show the size 1054 of a typical mask held by clamp 312. View 1070 shows the size 1072 of a cleaning tool (e.g., a cleaning mask) 302 (also shown in previous figures) in its extended configuration. Size 1072 is large enough to contact clamp 312 and / or diaphragm 1052 for cleaning. Cleaning tool 302 is configured to expand and retract between size 1054 and size 1072 and / or other sizes. In some embodiments, such as Figure 10 As shown, cleaning tool 302 is configured to operate in a separate dimension (e.g., according to...). Figure 10 The orientation is extended in the "x" or horizontal dimension. However, in some embodiments, the cleaning tool 302 may be configured to extend in more than one dimension (e.g., in the "x" and "y" dimensions) to properly engage the target cleaning surface. It should be noted that in the contracted dimension 1054, the cleaning tool 302 is configured to be fitted in a container 304 (as shown in the previous figure), so that the cleaning tool 302 can be loaded into the lithography apparatus 300 and moved through the lithography apparatus 300, as with typical photomasks (e.g., via the turntable clamp 306 of the photomask handler, the robot clamp 307 of the photomask handler, the fixture 308, etc.), and / or other components.

[0116] Return to Figure 7 In some embodiments, container 304 includes a tray, a flat plate, and / or other structures. In some embodiments, container 304 is generally rectangular or square in shape, such as... Figure 7As shown in the figure. In some embodiments, the container has been configured such that container 304 is fitted to a lithography apparatus 300 as described above. Figure 3A and Figure 3B The length 722 and / or width 724 in the container. In some embodiments, the container 304 has a base surface 720, sidewalls 726, and / or other components. In some embodiments, the base surface 720 may be substantially planar. In some embodiments, such as Figure 7 As shown, the substrate surface 720 can be configured with one or more different depths 730. Depths 730 can accommodate one or more embodiments of the cleaning tool 302, for example, such that the container 304 accommodates the cleaning tool 302. Depths 730 can be configured such that the container 304 is fitted into the photolithography apparatus 300. In some embodiments, the container 304 is formed of metal, polymer, ceramic, and / or other materials.

[0117] In some embodiments, container 304 includes one or more retractable members 702 configured to return the cleaning tool 302 to container 304 after cleaning (e.g., as shown in the image). Figure 6 As shown in the diagram, the cleaning tool 302 is assisted to retract from an extended configuration to a retracted configuration. In some embodiments, the one or more retracting members 702 include ridges in the container 304 configured to push the cleaning tool 302 as it returns to the container 304 after cleaning. In some embodiments, other extending members include, but are not limited to, spring-loaded members and / or other members actuated by vacuum, pneumatic, electromechanical means. Magnets may be included, coupled to the container 304, the cleaning mask (tool) 302, and / or the turntable clamp 306, and said magnets provide motive force via a magnetic field to extend and / or retract the cleaning mask 302. It should be noted that this description of the container 304 is not intended to be limiting. The container 304 may have any shape, any size and / or features, and may be made of any material that allows it to function as described herein.

[0118] Figure 11 An example of a cleaning tool (e.g., a mask) 302 is described below. As described above, in some embodiments, the cleaning tool 302 includes one or more tool handler engagement surfaces and / or cleaning portions having cleaning surfaces that move relative to each other, one or more links connected by hinged joints, one or more flexible portions, one or more rotating portions, and / or other components configured to facilitate expansion or contraction between a retracted (first) configuration and an expanded (second) configuration. For simplicity and to facilitate the discussion below, Figure 11The cleaning tool is described as a single block of material shaped like a rectangular prism. This is not intended to be limiting. The principles and / or features described below can be applied. Figure 3A , Figure 3B , Figure 4 and Figures 6 to 10 The embodiments of cleaning tool 302 shown herein, and / or may be included in separate embodiments of cleaning tool 302.

[0119] In some embodiments, one or more portions of the cleaning tool 302 (e.g., the mating surface, the cleaning portion, etc.) may be formed of a transparent or nearly transparent material, such as ultra-low thermal expansion quartz (SFS) and / or other materials. However, this requirement is for photolithography. The cleaning mask (tool) 302 can be fabricated using any number of materials, subject to the limitation that the external dimensions and quality comply with SEMI standard P1 for Hard Surface Photomask Substrates. In some embodiments, the cleaning tool 302 (e.g., Figure 11 The cleaning tool 302 (as shown) includes a cleaning surface 1100 (similar to and / or identical to the cleaning surface 700 described above), an identification surface 1102, one or more side surfaces 1104, and / or other components. The identification surface is on the side of the cleaning tool 302 opposite to the cleaning surface 1100, and is as follows: Figure 11 Below the inspection (identification) surface 1102 shown. In some embodiments, the cleaning tool 302 further includes one or more identification features 1106, 1108. Identification features 1106 and 1108 may include a pre-alignment mark 1106, a barcode 1108, and / or other identification features. The cleaning tool 302 is configured such that identification features 1106 and 1108 are visible through the identification surface 1102.

[0120] In some embodiments, identification features 1106 and 1108 may be located on the clean surface 1100, such as Figure 11As shown in the diagram. In such embodiments, the cleaning surface 1100 is partially covered by a cleaning material. In some embodiments, the cleaning material includes one or more different materials. The material used for cleaning the diaphragm may vary depending on the contaminants to be removed. The cleaning material can be permanently applied to the tool mask by sputtering / vapor deposition, bonding, and / or other operations. Commercially available cleaning materials for optical / electronic / medical devices can also be bonded or otherwise attached in a manner configured to allow for removal and replacement. Examples of materials include, but are not limited to, woven polyester, woven synthetic fibers, open-cell or closed-cell polyethylene foam, and / or some combination thereof. To remove “loose” particles, double-sided tape, polyimide tape, Achilles tape, etc., can be used to utilize “adhesive” surfaces. The cleaning material is configured to contact and clean the mask stage 310 ( Figure 3A and Figure 3B Mask fixture 312 Figure 3A and Figure 3B ) and / or the associated diaphragm as described above. In such embodiments, the cleaning surface 1100 may be configured to have gaps in the cleaning material corresponding to, for example, the locations of identification features 1106 and 1108. These gaps can be created by cutting and / or otherwise removing the cleaning material in the regions corresponding to the locations of identification features 1106 and 1108. Gaps may remain in the cleaning material because the cleaning material is typically opaque or nearly opaque, and identification features 1106 and 1108 are configured to be formed by the photolithography apparatus 300 ( Figure 3A and Figure 3B The camera in the image uses illumination to read the image, which is transmitted from the cleaning surface 1100 side of the cleaning tool 302 into the cleaning tool 302 and exits the cleaning tool 302 through the identification surface 1102. In this embodiment, the cleaning material covering all cleaning surfaces 1100 will block the transmission of illumination into the cleaning tool 302. (It should be noted that it may be possible to use through holes instead of pre-alignment marks 1106, and reduce the need for gaps in the cleaning material rather than barcodes 1108.)

[0121] In some embodiments, substantially the entire cleaning surface 1100 may be covered with cleaning material. Advantageously, this maximizes the area cleaned by the cleaning surface 1100. In such embodiments, the cleaning tool 302 may be configured with an internal illumination source and identification features 1106 and 1108 located between the cleaning surface 1100 and the identification surface 1102, such that the identification features 1106 and 1108 are visible through the identification surface using light from the internal illumination source. For example, in some embodiments, the cleaning tool 302 includes one or more inner surfaces between the cleaning surface 1100 and the identification surface 1102. The identification features 1106 and 1108 may be located on one or more of these inner surfaces.

[0122] As a non-limiting example, the glass layer can form the identification surface 1102. This glass layer can be a mask sheet, wherein identification features 1106 and / or 1108 are printed on and / or otherwise formed on the inner (facing the clean surface 100) side of the glass layer. This can be for a turntable clamp 306 ( Figure 3A and Figure 3B The cleaning tool 302 provides a smooth and continuous opposite (or outer) surface 1100 for the glass layer. The remaining volume of the cleaning tool 302 can be filled by assembling the layered structure via joining, optical contact, mechanical assembly, and / or other operations to provide additional layers and / or areas configured to hold the irradiation source for irradiating identification features 1106 and / or 1108. Cleaning material can then be mounted onto any portion of the cleaning surface 1100 to the cleaning tool (e.g., a mask) 302, as the cleaning material does not obstruct the irradiation required to read identification features 1106 and / or 1108.

[0123] Advantageously, positioning the identification features 1106, 1108 and / or other features on the inner surface will keep the identification surface 1102 smooth and / or continuous for use by the turntable clamp 306. Figure 3A and Figure 3B Clamping. For example, the turntable clamp 306 may require a 600-foot support. Figures 7 to 9 A specific coefficient of friction between the support leg 600 and the cleaning tool 302 ensures that the support leg 600 is properly positioned when lowered to the cleaning tool (e.g., mask) 302. A continuous surface for sealing may also be required when vacuuming to lift and / or otherwise move the cleaning tool (e.g., mask) 302. A smooth identification surface 1102 can solve these and other problems.

[0124] As an explanation, Figure 12 View 1200 shows the turntable clamp 306 and the support leg 600 as seen through the cleaning tool 302 (upward). Figure 12Also shown are enlarged views 1202 and 1204 of the foot 600 positioned relative to the identification feature 1106 (as an example). As described above, the foot 600 of the turntable clamp 306 may require a continuous surface for sealing when vacuuming to lift and / or otherwise move the cleaning tool (e.g., mask plate) 302.

[0125] Figure 13 An exemplary embodiment of a layered version of a cleaning tool 302 is described, the cleaning tool having an illumination source 1300 located within the interior 1302 of the cleaning tool 302 between a cleaning surface 1100 and a recognition surface 1102. The illumination source 1300 is configured to provide illumination such that one or more recognition features 1106 and / or 1108 are visible through the recognition surface 1102. In some embodiments, the illumination source 1300 includes a light-emitting diode (LED). In some embodiments, the illumination source 1300 includes an illumination guide 1304 configured to direct illumination from the LED toward one or more recognition features 1106 and / or 1108 and through the recognition surface 1102. For example, as... Figure 13 As shown, the illumination guide 1304 may include one or more cavities 1305 positioned near the identification features 1106 and / or 1108. The illumination guide 1304 may also include various channels, reflective surfaces, etc., configured to guide light through the identification features 1106 and / or 1108 and through the identification surface 1102.

[0126] In some embodiments, instead of LEDs and / or other LEDs, the illumination source 1300 may include ambient light configured to direct from the ambient atmosphere (e.g., below the cleaning tool 302) through the interior 1302 of the cleaning tool 302 toward one or more identification features 1106 and / or 1108 and through one or more mirrors and / or other reflective surfaces of the identification surface 1102. In some embodiments, the interior 1302 may include power storage devices, such as a battery 1320 and / or other power sources for the illumination source 1300, wiring 1322 connecting the battery 1320 to the illumination source 1300, a removable access cover configured to provide user access to the interior 1302, and / or other components configured to allow the cleaning tool 302 to function as described herein. In some embodiments, the illumination source 1300 may be and / or include a passive illumination device configured to capture illumination from the center of a mask (the center of the mask is not covered) and direct the illumination upward through the identification mark via mirrors, lenses, prisms, and / or other optical elements. In some embodiments, illumination may also be provided by "glowing in the dark" paint or other similar products (such as a small bottle of tritium and / or other materials).

[0127] Figure 14 A method 1400 for cleaning a portion of a photolithography apparatus is described. For example, method 1400 may be performed using a cleaning system. In some embodiments, the cleaning system includes cleaning tools, containers, and / or other components. The operational intent of method 1400 presented below is illustrative. In some embodiments, method 1400 may be implemented with one or more additional operations not described and / or without one or more of the operations discussed. Additionally, in Figure 14 The order of operations described in the text and in the following text is not intended to be restrictive.

[0128] In some embodiments, one or more portions of method 1400 may be implemented in and / or controlled by one or more processing devices (e.g., digital processors, analog processors, digital circuits designed to process information, analog circuits designed to process information, state machines, and / or other mechanisms for electronically processing information). One or more processing devices may include one or more means that perform some or all of the operations of method 1400 in response to instructions electronically stored on an electronic storage medium. One or more processing devices may include one or more means configured via hardware, firmware, and / or software that are specifically designed to perform one or more operations of method 1400 (e.g., see the following section on...). Figure 15 (as discussed herein). For example, one or more processing devices may execute software configured to perform cleaning procedures (e.g., ASML Twinscan) that cause one or more of the operations described herein to be performed.

[0129] At operation 1402, a cleaning tool is inserted into a lithography apparatus. In some embodiments, the lithography apparatus is configured for DUV irradiation. In some embodiments, the cleaning tool includes a cleaning mask. The cleaning tool is in a retracted first configuration when inserted into the lithography apparatus. The cleaning tool is in a container when inserted into the lithography apparatus. In some embodiments, operation 1402 is performed by a tool handler of the lithography apparatus (e.g., Figure 3A and Figure 3B The mask plate handler robot clamp 307 shown in the diagram and described herein, and / or other components, are used to perform this function.

[0130] At operation 1404, a cleaning tool is engaged and moved via a second portion of the tool handler of the lithography apparatus. In some embodiments, the second portion of the tool handler may be a turntable clamp and / or other components of a mask handler. In some embodiments, operation 1404 is performed by a turntable clamp 306 that is identical to or similar to the turntable clamp (e.g., Figure 3A and Figure 3B The turntable clamp of the mask processor (shown in the figure and described in this article) is used to perform the operation.

[0131] At operation 1406, the cleaning tool moves from a first configuration to an extended second configuration. In some embodiments, operation 1406 occurs in response to the cleaning tool being lifted outside the container by a second portion of the tool handler (e.g., a turntable clamp). In some embodiments, this movement is facilitated by one or more links in the cleaning tool connected by articulated joints, the links being configured to facilitate expansion or contraction between the first and second configurations. In some embodiments, this movement is facilitated by one or more flexible portions of the cleaning tool, the flexible portions being configured to facilitate expansion or contraction between the first and second configurations. In some embodiments, this movement is facilitated by one or more rotating portions of the cleaning tool, the rotating portions being configured to facilitate expansion or contraction between the first and second configurations. In some embodiments, operation 1406 is performed by a cleaning tool as described above (e.g., such as...). Figure 3A and Figure 3B The cleaning tool 302 shown in the figure and described herein is used to perform the cleaning.

[0132] At operation 1408, a cleaning tool is used to clean a portion of the photolithography apparatus. The cleaning tool is in an extended second configuration when used to clean said portion of the photolithography apparatus. In some embodiments, said portion of the photolithography apparatus includes a mask holder for a mask stage. In some embodiments, operation 1408 is performed by a cleaning tool as described above (e.g., such as...). Figure 3A and Figure 3B The cleaning tool 302 shown in the figure and described herein is used to perform the cleaning.

[0133] At operation 1410, the cleaning tool is returned to the container. The cleaning tool is returned to the container via a second portion of the tool handler. The cleaning tool is configured to move from a second (expanded) configuration to a first (contracted) configuration when it is returned to the container by the second portion of the tool handler after cleaning. In some embodiments, the container includes one or more contraction components. Operation 1410 includes facilitating the contraction of the cleaning tool from the second configuration to the first configuration using the contraction components when the cleaning tool is returned to the container after cleaning. The return of the cleaning tool to the container is performed by the second portion of the tool handler (e.g., a turntable clamp). In some embodiments, the second portion of the tool handler may be connected to (… Figure 3A and Figure 3B The turntable clamp 306 shown in the figure and described herein is the same as or similar to that shown in the figure.

[0134] In some embodiments, method 1400 includes (e.g., as described above regarding) Figures 11 to 13As described in the description: providing a cleaning surface on a cleaning tool that is at least partially covered by a cleaning material; providing an identification surface on the cleaning tool on the opposite side of the cleaning tool relative to the cleaning surface; providing one or more identification features on the cleaning tool located on one or more inner surfaces of the cleaning tool between the cleaning surface and the identification surface, the one or more identification features being visible through the identification surface; providing an illumination source inside the cleaning tool located between the cleaning surface and the identification surface, the illumination source being configured to provide illumination such that the one or more identification features are visible through the identification surface; and / or other operations.

[0135] Figure 15 This is a block diagram illustrating a computer system 100 that may aid in implementing the methods, processes, or one or more systems disclosed herein. The computer system 100 includes a bus 102 or other communication mechanism for conveying information, and a processor 104 (or a plurality of processors 104 and 105) coupled to the bus 102 for processing information. The computer system 100 also includes a main memory 106, such as random access memory (RAM) or other dynamic storage device, coupled to the bus 102 for storing information and instructions to be executed by the processor 104. The main memory 106 may also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processor 104. The computer system 100 also includes a read-only memory (ROM) 108 or other static storage device coupled to the bus 102 for storing static information and instructions for the processor 104. A storage device 110, such as a magnetic disk or optical disk, is provided and coupled to the bus 102 for storing information and instructions.

[0136] Computer system 100 can be connected via bus 102 to a display 112 for displaying information to a computer user, such as a cathode ray tube (CRT), flat panel display, or touch panel display. Input device 114, including letter keys and other buttons, is connected to bus 102 to transmit information and command selections to processor 104. Another type of user input device is a cursor controller 116, such as a mouse, trackball, or cursor direction keys, for transmitting directional information and command selections to processor 104 and for controlling cursor movement on display 112. This input device typically has two degrees of freedom in two axes (a first axis (e.g., x) and a second axis (e.g., y)), allowing the device to specify its position in a plane. Touch panel (screen) displays can also be used as input devices.

[0137] According to one embodiment, a portion of one or more methods described herein can be performed by computer system 100 in response to processor 104 executing one or more sequences of one or more instructions contained in main memory 106. Such instructions may be read into main memory 106 from another computer-readable medium, such as storage device 110. Execution of the instruction sequences contained in main memory 106 causes processor 104 to execute the program steps described herein. One or more processors in a multiprocessor configuration may also be used to execute the instruction sequences contained in main memory 106. In alternative embodiments, hardwired circuitry may be used instead of or in combination with software instructions. Therefore, the description herein is not limited to any particular combination of hardware circuitry and software.

[0138] As used herein, the term "computer-readable medium" refers to any medium that participates in providing instructions to processor 104 for execution. This medium can take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical discs or magnetic disks, such as storage device 110. Volatile media include dynamic memory, such as main memory 106. Transmission media include coaxial cables, copper wires, and optical fibers, including wiring including bus 102. Transmission media can also take the form of sound waves or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media include, for example, floppy disks, flexible disks, hard disks, magnetic tapes, any other magnetic media, CD-ROMs, DVDs, any other optical media, punched cards, paper tapes, any other physical media with a perforated pattern, RAM, PROMs and EPROMs, FLASH-EPROMs, any other memory chips or cartridges, carrier waves as described below, or any other medium that can be read by a computer.

[0139] The execution of one or more instructions, or a sequence thereof, can involve various forms of computer-readable media. For example, the instructions may initially be carried on the disk of a remote computer. The remote computer may load the instructions into its dynamic memory and transmit them via a telephone line using a modem. A modem local to computer system 100 may receive data over the telephone line and use an infrared transmitter to convert the data into an infrared signal. An infrared detector coupled to bus 102 may receive the data carried in the infrared signal and place the data on bus 102. Bus 102 carries the data to main memory 106, from which processor 104 fetches and executes instructions. Instructions received by main memory 106 may optionally be stored on storage device 110 before or after execution by processor 104.

[0140] Computer system 100 may also include a communication interface 118 coupled to bus 102. Communication interface 118 provides a bidirectional data communication connection to network link 120, which is connected to local area network 122. For example, communication interface 118 may be an Integrated Services Digital Network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface 118 may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. A wireless link may also be implemented. In any such implementation, communication interface 118 transmits and receives electrical, electromagnetic, or optical signals carrying digital data streams representing various types of information.

[0141] Network link 120 typically provides data communication to other data devices via one or more networks. For example, network link 120 may provide a connection to host computer 124 via local area network 122 or to data devices operated by Internet service provider (ISP) 126. ISP 126, in turn, provides data communication services via a global packet data communication network (now commonly referred to as the "Internet") 128. Both local area network 122 and Internet 128 use electrical, electromagnetic, or optical signals carrying digital data streams. Signals via various networks and signals on network link 120 and via communication interface 118 (which carry digital data to and from computer system 100) are exemplary forms of carriers for transmitting information.

[0142] Computer system 100 can send messages and receive data, including program code, via one or more networks, network links 120, and communication interfaces 118. In the example of the Internet, server 130 may transmit requested program code for an application via the Internet 128, ISP 126, local area network 122, and communication interface 118. Such a downloaded application can provide all or part of the methods described herein, for example. The received program code can be executed by processor 104 upon receipt and / or stored in storage device 110 or other non-volatile memory for later execution. In this way, computer system 100 can obtain application code in carrier form.

[0143] Figure 16 The illustration depicts techniques that can be used in conjunction with those described herein. Figure 1 , Figure 3A and / or Figure 3B The exemplary photolithography projection device 1000 shown is similar to and / or identical to the device described herein. Device 1000 can generally represent, for example, a DUV device with a dual-scan configuration (this example is not intended to be limiting). The device includes:

[0144] - Irradiation system IL, which is used to modulate the radiation beam B. In this specific case, the irradiation system also includes a radiation source SO;

[0145] - A first platform (e.g., a pattern forming apparatus stage) MT, the first platform having a pattern forming apparatus holder for holding a pattern forming apparatus MA (e.g., a mask), and connected to a first locator for accurately positioning the pattern forming apparatus relative to an article PS;

[0146] - Second platform (substrate stage) WT, which has a substrate holder for holding substrate W (e.g., a silicon wafer coated with resist) and is connected to a second positioner for accurately positioning the substrate relative to article PS;

[0147] - A projection system (“lens”) PS (e.g., a refractive, reflective, or reflective-refractive optical system) for imaging an illuminated portion of the pattern forming apparatus MA onto a target portion C (e.g., comprising one or more dies) of the substrate W.

[0148] As described herein, the device is of the transmissive type (i.e., having a transmissive pattern forming apparatus). However, the device can also typically be of the reflective type, for example (having a reflective pattern forming apparatus). The device may use a different kind of pattern forming apparatus than a classic mask; examples include programmable mirror arrays or LCD matrices.

[0149] A source SO (e.g., a mercury lamp or excimer laser, laser-generated plasma (LPP) EUV source) generates a radiation beam. This beam is fed, for example, directly or after passing through an adjustment member such as a beam expander Ex into an irradiation system (irradiator) IL. The irradiator IL may include adjustment members for setting the outer radial range and / or inner radial range (typically referred to as σ_outer and σ_inner, respectively) of the intensity distribution in the beam. Additionally, the irradiator IL will typically include various other components, such as a beam concentrator and a condenser. Thus, the beam B irradiated onto the pattern forming apparatus MA has the desired uniformity and intensity distribution in its cross-section.

[0150] about Figure 16 It should be noted that the source SO can be inside the housing of the photolithography projection device (e.g., this is often the case when the source SO is a mercury lamp), but the source SO can also be located away from the photolithography projection device, and the radiation beam generated by the source SO is guided into the device (e.g., by means of a suitable guiding mirror); the latter scenario is often the case when the source SO is an excimer laser (e.g., based on KrF, ArF or F2 laser action).

[0151] The beam then intercepts the pattern forming apparatus MA held on the pattern forming apparatus stage MT. Having traversed the pattern forming apparatus MA, the beam B passes through the lens PL, which focuses the beam B onto the target portion C of the substrate W. The substrate stage WT can be accurately moved, for example, to position the different target portions C within the path of the beam, by means of a second positioning member (and an interferometric member). Similarly, the first positioning member can be used, for example, to accurately position the pattern forming apparatus MA relative to the path of the beam B after it has been mechanically retrieved from the pattern forming apparatus library or during scanning. Typically, the movement of the object platform MT, WT is achieved by means of long-stroke modules (coarse positioning) and short-stroke modules (fine positioning), which are not explicitly depicted. However, in the case of a stepper (relative to a stepping scanning tool), the pattern forming apparatus stage MT may be connected only to the short-stroke actuator, or it may be fixed.

[0152] The depicted tools can be used in two different modes:

[0153] - In step mode, the patterning apparatus stage MT is kept substantially stationary, and the entire patterning apparatus image is projected onto the target portion C in one operation (i.e., a single "flash"). Then, the substrate stage WT is shifted in the x and / or y directions so that different target portions C can be irradiated by the beam;

[0154] In scanning mode, essentially the same scenario applies, except that the given target portion C is not exposed in a single "flash". Instead, the pattern forming apparatus stage MT can move at a speed v in a given direction (the so-called "scanning direction", e.g., the y-direction), causing the projection beam B to scan the entire pattern forming apparatus image; simultaneously, the substrate stage WT moves simultaneously in the same or opposite direction at a speed V = Mv, where M is the magnification of the lens PL (typically M = 1 / 4 or 1 / 5). In this way, a relatively large target portion C can be exposed without compromising resolution.

[0155] The embodiments can be further described in the following aspects:

[0156] 1. A system for cleaning a portion of a photolithography apparatus, the system comprising:

[0157] A cleaning tool configured to be inserted into the lithography apparatus in a first configuration, engaged by the tool handler of the lithography apparatus, and used to clean the portion of the lithography apparatus;

[0158] The cleaning tool is configured to move from the first configuration to an extended second configuration after being engaged by the tool handler, such that the cleaning tool is in the second configuration when used to clean the portion of the lithography apparatus.

[0159] 2. The system as described in aspect 1 further includes a container configured to contain the cleaning tool in the first configuration and fitted into the lithography apparatus, wherein the cleaning tool is configured to be inserted into the lithography apparatus in the container, removed from the container by the tool handler for the cleaning, and returned to the container by means of the tool handler after the cleaning.

[0160] 3. The system of aspect 2, wherein the cleaning tool is configured to move from the first configuration to the second configuration when the cleaning tool is removed from the container by the tool handler for cleaning.

[0161] 4. The system of any one of aspects 2 to 3, wherein the cleaning tool is configured to move from the second configuration to the first configuration when the cleaning tool is returned to the container by means of the tool handler after cleaning.

[0162] 5. The system of any one of aspects 2 to 4, wherein the container includes one or more retractable components configured to facilitate the retraction of the cleaning tool from the second configuration to the first configuration when the cleaning tool returns to the container after the cleaning.

[0163] 6. The system of aspect 5, wherein the one or more retractable members include a ridge in the container, the ridge being configured to push the cleaning tool when the cleaning tool returns to the container after the cleaning.

[0164] 7. The system of any one of aspects 1 to 6, wherein the portion of the lithography apparatus includes a mask fixture for a mask stage.

[0165] 8. The system of any one of aspects 1 to 7, wherein the cleaning tool comprises a cleaning mask.

[0166] 9. The system of any one of aspects 1 to 8, wherein the tool handler includes a turntable clamp for the mask handler.

[0167] 10. The system of any one of aspects 1 to 9, wherein the lithography apparatus is configured for deep ultraviolet (DUV) radiation.

[0168] 11. The system of any one of aspects 1 to 10, wherein the first configuration includes a shrink configuration relative to the second configuration.

[0169] 12. The system of any one of aspects 1 to 11, wherein the cleaning tool includes one or more links connected by a hinge joint, the one or more links connected by the hinge joint being configured to facilitate expansion or contraction between the first configuration and the second configuration.

[0170] 13. The system of any one of aspects 1 to 12, wherein the cleaning tool includes one or more flexible portions configured to facilitate expansion or contraction between the first configuration and the second configuration.

[0171] 14. The system of any one of aspects 1 to 13, wherein the cleaning tool includes one or more rotating portions configured to facilitate expansion or contraction between the first configuration and the second configuration.

[0172] 15. The system of any one of aspects 1 to 14, wherein the cleaning tool further comprises one or more tool handler engagement surfaces, the one or more tool handler engagement surfaces being configured to remain in a position and orientation corresponding to the tool handler regardless of whether the cleaning tool is in the first configuration or the second configuration.

[0173] 16. The system of aspect 15, wherein the cleaning tool further comprises one or more cleaning surfaces configured to move relative to the one or more tool handler engagement surfaces as the cleaning tool moves between the first configuration and the second configuration.

[0174] 17. The system of aspect 16, wherein the one or more cleaning surfaces are configured to contact one or more target surfaces of the portion of the lithography apparatus for cleaning when the cleaning tool is in the second configuration.

[0175] 18. The system of aspect 17, wherein the one or more cleaning surfaces are configured to be parallel to the one or more target surfaces when the cleaning tool is in the second configuration.

[0176] 19. The system of aspect 18, wherein the one or more target surfaces include one or more diaphragm surfaces of the lithography apparatus.

[0177] 20. The system of any one of aspects 1 to 19, wherein the cleaning tool comprises:

[0178] A clean surface that is at least partially covered by cleaning material;

[0179] A recognition surface, the recognition surface being located on the opposite side of the cleaning tool relative to the cleaning surface; and

[0180] One or more identification features are located between the clean surface and the identification surface, and the one or more identification features are visible through the identification surface.

[0181] 21. The system of aspect 20, wherein the cleaning surface is opaque and the identification surface is transparent.

[0182] 22. The system of any one of aspects 20 to 21, wherein the cleaning tool further comprises one or more inner surfaces between the cleaning surface and the identification surface, and wherein the one or more identification features are located on the one or more inner surfaces.

[0183] 23. The system of any one of aspects 20 to 22, wherein the one or more identification features include one or both of a barcode and an alignment mark.

[0184] 24. The system of any one of aspects 20 to 23, wherein the cleaning tool further includes an illumination source located inside the cleaning tool between the cleaning surface and the identification surface, the illumination source being configured to provide illumination such that the one or more identification features are visible through the identification surface.

[0185] 25. The system of aspect 24, wherein the irradiation source comprises a light-emitting diode (LED).

[0186] 26. The system of aspect 25, wherein the irradiation source further includes an irradiation guide configured to direct irradiation from the LED toward and through the one or more identification features and across the identification surface.

[0187] 27. The system of aspect 24, wherein the illumination source comprises one or more mirrors configured to direct ambient light from below the cleaning tool through the interior of the cleaning tool toward the one or more identification features and through the identification surface.

[0188] 28. A method for cleaning a portion of a photolithography apparatus using a cleaning tool, the method comprising:

[0189] The cleaning tool is inserted into the photolithography apparatus in the first configuration;

[0190] The cleaning tool is engaged with the tool handler of the lithography equipment;

[0191] Move the cleaning tool from the first configuration to the extended second configuration; and

[0192] The cleaning tool is used to clean the portion of the lithography equipment when it is in the extended second configuration.

[0193] 29. The method of aspect 28, further comprising: containing the cleaning tool in the first configuration in a container and inserting the cleaning tool in the container into the lithography apparatus, removing the cleaning tool from the container for the cleaning using the tool handler, and returning the cleaning tool to the container using the tool handler after the cleaning.

[0194] 30. The method of aspect 29, further comprising: moving the cleaning tool from the first configuration to the second configuration when the cleaning tool is removed from the container by the tool handler for cleaning.

[0195] 31. The method of any one of aspects 28 to 30, further comprising: moving the cleaning tool from the second configuration to the first configuration when the cleaning tool is returned to the container by means of the tool handler after cleaning.

[0196] 32. The method of any one of aspects 28 to 31, further comprising: in response to the cleaning tool being returned to the container after the cleaning, retracting the cleaning tool from the extended second configuration using a retraction member.

[0197] 33. The method of any one of aspects 28 to 32, wherein the portion of the photolithography apparatus includes a mask fixture for a mask stage.

[0198] 34. The method of any one of aspects 28 to 34, wherein the cleaning tool comprises a cleaning mask.

[0199] 35. The method of any one of aspects 28 to 34, wherein the tool handler comprises a turntable clamp for a mask handler.

[0200] 36. The method of any one of aspects 28 to 35, wherein the lithography apparatus is configured for deep ultraviolet (DUV) radiation.

[0201] 37. The method of any one of aspects 28 to 36, wherein the movement is facilitated by one or more links in the cleaning tool connected by a hinged joint, the one or more links being configured to facilitate expansion or contraction between the first configuration and the second configuration.

[0202] 38. The method of any one of aspects 28 to 37, wherein the movement is facilitated by one or more flexible portions of the cleaning tool, the one or more flexible portions being configured to facilitate expansion or contraction between the first configuration and the second configuration.

[0203] 39. The method of any one of aspects 28 to 38, wherein the movement is facilitated by one or more rotating portions of the cleaning tool, the one or more rotating portions being configured to facilitate expansion or contraction between the first configuration and the second configuration.

[0204] 40. The method as described in any one of aspects 28 to 39, further comprising:

[0205] The cleaning tool provides a cleaning surface that is at least partially covered by the cleaning material;

[0206] A recognition surface is provided on the cleaning tool, the recognition surface being located on the opposite side of the cleaning tool relative to the cleaning surface;

[0207] One or more identification features are provided on the cleaning tool, the one or more identification features being located on one or more inner surfaces of the cleaning tool between the cleaning surface and the identification surface, the one or more identification features being visible through the identification surface; and

[0208] An illumination source is provided inside the cleaning tool, located between the cleaning surface and the identification surface, the illumination source being configured to provide illumination such that the one or more identification features are visible through the identification surface.

[0209] 41. A computer program product comprising a non-transitory computer-readable medium having instructions recorded thereon, which, when executed by a computer, perform the method as described in any one of aspects 28 to 40.

[0210] While the concepts disclosed herein can be used in wafer fabrication on substrates such as silicon wafers, it should be understood that the disclosed concepts can be used in any type of manufacturing system, for example, a manufacturing system for fabrication on substrates other than silicon wafers. Furthermore, combinations and sub-combinations of the disclosed elements can include individual embodiments. For example, an expanding and contracting cleaning tool ( Figures 3A to 10) and internal irradiation cleaning (e.g., Figures 11 to 13 It may also include separate embodiments, and / or these features may be used together in the same embodiment.

[0211] The above description is intended to be illustrative and not restrictive. Therefore, it will be apparent to those skilled in the art that modifications can be made as described without departing from the scope of the claims set forth below.

Claims

1. A system for cleaning a portion of a lithographic apparatus, the system comprising: a cleaning tool configured to be inserted into the lithographic apparatus in a first configuration, engaged by a tool handler of the lithographic apparatus, and used to clean the portion of the lithographic apparatus; wherein the cleaning tool is configured to move from the first configuration to an expanded second configuration after being engaged by the tool handler and before the cleaning tool makes any contact with the portion of the lithographic apparatus, such that the cleaning tool is in the second configuration when used to clean the portion of the lithographic apparatus.

2. The system of claim 1, further comprising a container configured to house the cleaning tool in the first configuration and to fit into the lithography apparatus, wherein, the cleaning tool is configured to be inserted into the lithographic apparatus in the container, removed from the container by the tool handler for the cleaning, and returned to the container after the cleaning with the aid of the tool handler.

3. The system of claim 2, wherein, the cleaning tool is configured to move from the first configuration to the second configuration when the cleaning tool is removed from the container by the tool handler for cleaning.

4. The system of claim 2, wherein, the cleaning tool is configured to move from the second configuration to the first configuration when the cleaning tool is returned to the container after cleaning with the aid of the tool handler.

5. The system of claim 2, wherein, the container comprises one or more retraction features configured to facilitate retraction of the cleaning tool from the second configuration to the first configuration when the cleaning tool is returned to the container after the cleaning.

6. The system of claim 5, wherein, the one or more retraction features comprise a ridge in the container configured to push against the cleaning tool when the cleaning tool is returned to the container after the cleaning.

7. The system of claim 1, wherein: the portion of the lithographic apparatus comprises a reticle clamp of a reticle stage; the cleaning tool comprises a cleaning reticle; the tool handler comprises a turntable gripper of a reticle handler; the lithographic apparatus is configured for deep ultraviolet (DUV) radiation.

8. The system of claim 1, wherein: the first configuration comprises a retracted configuration relative to the second configuration; and the cleaning tool comprises one or more links coupled by a hinged joint, the one or more links coupled by a hinged joint configured to facilitate expansion or retraction between the first configuration and the second configuration.

9. The system of claim 1, wherein, the cleaning tool comprises one or more flexible portions configured to facilitate expansion or retraction between the first configuration and the second configuration; and the cleaning tool comprises one or more rotational portions configured to facilitate expansion or retraction between the first configuration and the second configuration.

10. The system of claim 1, wherein, the cleaning tool further comprises one or more tool handler engagement surfaces configured to remain in a position and orientation corresponding to the tool handler regardless of whether the cleaning tool is in the first configuration or the second configuration.

11. The system of claim 10, wherein, The cleaning tool also includes one or more cleaning surfaces configured to move relative to the one or more tool handler engagement surfaces as the cleaning tool moves between the first configuration and the second configuration.

12. The system of claim 11, wherein, The one or more cleaning surfaces are configured to contact one or more target surfaces of the portion of the lithography apparatus for cleaning when the cleaning tool is in the second configuration.

13. The system of claim 12, wherein, The one or more cleaning surfaces are configured to be parallel to the one or more target surfaces when the cleaning tool is in the second configuration.

14. The system of claim 13, wherein, The one or more target surfaces include one or more septum surfaces of the lithography apparatus.

15. The system of claim 1, wherein, The cleaning tool includes: a cleaning surface at least partially covered by a cleaning material; an identification surface on an opposite side of the cleaning tool relative to the cleaning surface; and one or more identification features between the cleaning surface and the identification surface, the one or more identification features being visible through the identification surface.

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