Plasma fluorination of diamonds to improve the performance of spotless flat packs

Abstract

A tool for removing material from the surface of a wafer table and a method for forming a tool for removing material from the surface of a wafer table are disclosed. The tool includes a pack and a grinding layer provided on at least one surface of the pack. The surface of the grinding layer includes covalently bonded atoms on the surface of the grinding layer, so that the grinding layer resists clogging by the material being removed. The method includes providing a grinding layer on the surface of a pack. The surface of the grinding layer is treated to form covalently bonded atoms on the surface of the grinding layer, so that the grinding layer resists clogging by the material being removed.

Description

Technical Field

[0001] Cross - reference to related applications

[0001] This application claims the priority of U.S. Application No. 63 / 491,503, filed on March 21, 2023, which is hereby incorporated by reference in its entirety.

Background Art

[0002]

[0002] The present disclosure relates to a tool for removing material from the surface of a wafer table, for example, a tool for removing material produced by processing on the wafer table, and a method for manufacturing such a tool.

[0003]

[0003] A lithography apparatus is a machine for applying a desired pattern onto a substrate (usually a target portion of the substrate). The lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that case, a patterning device (which can be a mask or a reticle) can be used to generate the circuit patterns to be formed on the individual layers of the IC. This pattern can be transferred onto a target portion (for example, consisting of part of one or more dies) of a substrate (such as a silicon wafer). Usually, the transfer of the pattern is carried out through a layer of radiation - sensitive material (photoresist or simply "resist") provided on the substrate. Generally, a single substrate includes a network of adjacent target portions that are exposed continuously. Well - known lithography apparatuses include so - called steppers, in which each target portion is irradiated by exposing the entire pattern on the target portion in one exposure, and so - called scanners, in which the pattern is scanned in a given direction ("scanning direction") by a radiation beam while simultaneously scanning the target portion parallel or antiparallel to this scanning direction so that each target portion is irradiated. It is also possible to transfer the pattern from the patterning device to the substrate by printing the pattern onto the substrate.

[0004]

[0004] During lithography, different processing steps may require the sequential formation of different layers on the substrate. Therefore, it may be necessary to position the substrate with high precision relative to a previous pattern formed on the substrate. Generally, alignment marks are placed on the substrate so that they are aligned and positioned relative to a second object. The lithography apparatus may use an alignment device to detect the position of the alignment marks and to align the substrate using the alignment marks to ensure accurate exposure from the mask. Misalignment between alignment marks in two different layers is measured as an overlay error.

[0005]

[0005] During lithography operation, the wafer table holds and supports the wafer being processed. To ensure the accuracy of the product wafer, the wafer table should be as flat as possible. However, during use in the lithography process, the wafer table may wear unevenly, resulting in a less flat surface. To slow down the progression of wear, hard coatings such as diamond-like carbon (DLC) may be applied to the wafer surface, but are not limited to this example.

[0006]

[0006] One method for removing material from a wafer table is to scrape the material off the wafer table using a tool having an abrasive surface. In some embodiments, the tool may include a puck in which a layer of abrasive material is provided. However, during use of the puck, the material being removed from the wafer table may clog the holes in the abrasive material, resulting in a reduced effectiveness of grinding and cleaning the wafer table. In some cases, such clogging may lead to effectively "polishing" the wafer table instead of scraping the material off it as intended.

[0007]

[0007] Conventional methods for removing such material from a pack include burning the pack in a furnace or plasma to remove the material. However, such methods require a long unloading and cleaning process, reducing the throughput of wafer table cleaning. Alternatively, the pack may be simply replaced, but this method is costly due to the expense of producing a reasonably flat pack and providing a grinding layer to the pack. [Overview of the project]

[0008]

[0008] Therefore, there is a need for improved tools and methods for removing material from the surface of a wafer table.

[0009]

[0009] In some embodiments, the tool for removing material from the surface of the wafer table may include a pack. An abrasive layer may be provided on at least one surface of the pack. The surface of the abrasive layer includes atoms covalently bonded to the surface of the abrasive layer, so that the abrasive layer may resist clogging by the material being removed.

[0010]

[0010] In some embodiments, the covalent atoms may include fluorine. In some embodiments, the abrasive layer may include diamond having a hardness of 35 GPa or more. In some embodiments, the covalent atoms may include fluorine and be bonded to diamond. In some embodiments, the material to be removed includes diamond-like carbon (DLC).

[0011]

[0011] In some embodiments, a method for forming a tool for removing material from the surface of a wafer table may include providing a grinding layer on the surface of the pack. In some embodiments, the method may include treating the surface of the grinding layer to form covalent atoms on the surface of the grinding layer so that the grinding layer resists clogging by the material being removed.

[0012]

[0012] In some embodiments, the covalent atoms may include fluorine atoms. In some embodiments, the surface of the grinding layer may be fluorinated using plasma fluorination. In some embodiments, the surface of the grinding layer may be fluorinated using a perfluoroalkyl monolayer. In some embodiments, preparing the perfluoroalkyl monolayer may involve reacting a functionalized trialkoxysilane with the diamond surface. In some embodiments, treating the surface of the grinding layer may involve replacing hydrogen, oxygen and / or hydroxides in the grinding layer with fluorine atoms before treating the surface of the grinding layer. In some embodiments, the grinding layer may be provided by forming diamond having a hardness of 35 GPa or more. In some embodiments, treating the grinding layer may involve covalently bonding fluorine atoms to the diamond. In some embodiments, removing the material from the wafer table may involve removing diamond-like carbon (DLC).

[0013]

[0013] In some embodiments, a method for removing material from the surface of a wafer table may include grinding the wafer table using a tool for removing material from the wafer table. The tool may be formed according to the methods disclosed herein.

[0014]

[0014] Further features of various aspects of this disclosure are described below with reference to the accompanying drawings. Note that this disclosure is not limited to the specific aspects described herein. Such aspects are presented herein for illustrative purposes only. Additional aspects will become apparent to those skilled in the art based on the teachings contained herein. [Brief explanation of the drawing]

[0015]

[0015] The accompanying drawings incorporated herein and forming part of herein further illustrate the herein and, together with the following description, illustrate the principles of the herein and help enable persons skilled in the art to make and use the embodiments described herein. [Figure 1A]

[0016] Shows a reflective lithography apparatus according to some embodiments. [Figure 1B]

[0017] Shows a transmissive lithography apparatus according to some embodiments. [Figure 2]

[0018] Shows further details of a reflective lithography apparatus according to some embodiments. [Figure 3]

[0019] Shows a lithographic cell according to some embodiments. [Figure 4A]

[0020] Shows a pack according to some embodiments. [Figure 4B]

[0020] Shows a pack according to some embodiments. [Figure 5A]

[0021] Shows the grinding layer of a tool used to remove material from the surface of a wafer table according to some embodiments. [Figure 5B]

[0021] Shows the grinding layer of a tool used to remove material from the surface of a wafer table according to some embodiments. [Figure 6]

[0022] Shows a method of fabricating a tool according to some embodiments. [Figure 7]

[0023] Shows a tool fabricated according to some embodiments.

[0016]

[0024] The features of the present disclosure will become more apparent from the detailed description set forth below when considered in conjunction with the drawings in which like reference numerals identify corresponding elements throughout. In the drawings, like reference numbers generally identify identical elements, functionally similar elements, and / or structurally similar elements. Also, generally, the leftmost digit of a reference number identifies the figure in which that reference number first appears. The drawings provided throughout the present disclosure should not be construed as being drawn to scale unless otherwise indicated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]

[0025] The aspects described in this specification, and references to "one aspect", "an aspect", "an exemplary aspect", "an illustrative aspect", etc. in this specification, indicate that the described aspects may include a particular feature, structure, or property, but not all aspects necessarily include such a particular feature, structure, or property. Also, such language does not necessarily refer to the same aspect. Furthermore, when a particular feature, structure, or property is described in relation to an aspect, it is understood that, whether explicitly stated or not, it is within the knowledge of those skilled in the art to associate such a feature, structure, or property with other aspects.

[0018]

[0026] In this specification, spatially relative terms such as "below", "beneath", "lower", "above", "on", "higher", etc. are used for the purpose of facilitating description and can describe the relationship of one element or feature to another (or others) as shown in the drawings. The spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation shown in the drawings. The device can be otherwise oriented (rotated 90 degrees or other orientations), and the spatially relative descriptors used herein can be interpreted accordingly.

[0019]

[0027] The terms "about", "approximately", etc. used in this specification indicate a value of a given quantity that can vary based on a particular technique. Based on a particular technique, the terms "about", "approximately", etc. can indicate, for example, a value of a given quantity that varies within 10 - 30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0020]

[0028] Aspects of this disclosure can be implemented in hardware, firmware, software, or any combination thereof. Aspects of this disclosure can also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. A machine-readable medium can include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium can include read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, propagating signals in electrical, optical, acoustic or other forms (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Furthermore, firmware, software, routines and / or instructions may be described herein as performing specific operations. However, such descriptions are merely for convenience, and it should be understood that such operations result from a computing device, processor, controller, or other device that executes the firmware, software, routines, instructions, etc. The term “machine-readable medium” may be interchangeable with similar terms such as “computer program product,” “computer-readable medium,” or “non-temporary computer-readable medium.” The term “non-transient” may be used herein to characterize one or more forms of computer-readable media other than transient propagating signals.

[0021]

[0029] However, before describing such embodiments in more detail, it is useful to present exemplary environments in which embodiments of this disclosure can be implemented.

[0022]

[0030] Exemplary lithography system

[0031] Figures 1A and 1B show lithography apparatus 100 and lithography apparatus 100', respectively, which can carry out embodiments of the present disclosure. Lithography apparatus 100 and lithography apparatus 100' each include, namely, an illumination system (illuminator) IL configured to adjust a radiation beam B (e.g., deep ultraviolet or extreme ultraviolet); a support structure (e.g., a mask table) MT configured to support a patterning device (e.g., a mask, reticle, or dynamic patterning device) MA and connected to a first positioner PM configured to precisely position the patterning device MA; and a substrate table (e.g., a wafer table) WT configured to hold a substrate (e.g., a resist-coated wafer) W and connected to a second positioner PW configured to precisely position the substrate W. Lithography apparatuses 100 and 100' also have a projection system PS configured to project the pattern applied to the radiation beam B by the patterning device MA onto a target portion C of the substrate W (e.g., including one or more dies). In lithography apparatus 100, the patterning device MA and projection system PS are reflective. In lithography apparatus 100', the patterning device MA and projection system PS are transmissive.

[0023]

[0032] The illumination system IL may include various types of optical components, such as refractive, reflective, reflector-refracting, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof, for guiding, shaping, or controlling the radiant beam B.

[0024]

[0033] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA relative to the reference frame, the design of at least one of the lithography apparatus 100 and 100', and other conditions such as whether the patterning device MA is held in a vacuum environment. The support structure MT can hold the patterning device MA using mechanical, vacuum, electrostatic, or other clamping techniques. The support structure MT may be a frame or table that can be fixed or movable, for example. By using sensors, the support structure MT can reliably position the patterning device MA in a desired position relative to the projection system PS, for example.

[0025]

[0034] The term “patterning device” (MA) should be broadly interpreted to refer to any device that can be used to impart a pattern to the cross-section of a radiation beam B in order to create a pattern within a target portion C of a substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer within the device that is created within the target portion C to form an integrated circuit.

[0026]

[0035] The patterning device MA may be transmissive (as in lithography apparatus 100' in Figure 1B) or reflective (as in lithography apparatus 100 in Figure 1A). Examples of patterning devices MA include reticles, masks, programmable mirror arrays, or programmable LCD panels. Masks are well known in lithography and include various mask types such as binary, Levenson (alternating) phase shift, or halftone (attenuated) phase shift, as well as various hybrid mask types. In an example of a programmable mirror array, a matrix arrangement of small mirrors is used, each small mirror being individually tilted to reflect the incident radiation beam in various directions. The tilted mirrors impart a pattern to the radiation beam B reflected by the matrix of small mirrors.

[0027]

[0036] The term "projection system" PS can encompass any type of projection system, including refractive, reflective, reflector-refracting, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof, that is appropriate for the exposure radiation being used, or for other factors such as the use of immersion liquid or vacuum on the substrate W. A vacuum environment may be used for EUV or electron beam radiation because other gases may absorb too much radiation or electrons. Thus, a vacuum environment may be provided throughout the beam path with the help of vacuum walls and vacuum pumps.

[0028]

[0037] The lithography apparatus 100 and / or lithography apparatus 100' may be of a type having two or more substrate tables WT (and / or two or more mask tables). In such a “multistage” machine, additional substrate tables WT can be used in parallel, or one or more other tables WT can be used for exposure while preliminary steps are performed on one or more tables. In some situations, the additional tables may not be substrate tables WT.

[0029]

[0038] Furthermore, the lithography apparatus may be of a type that can cover at least a portion of the substrate with a liquid having a relatively high refractive index (e.g., water) to fill the space between the projection system and the substrate. Additionally, an immersion liquid may be added to other spaces within the lithography apparatus (e.g., between the mask and the projection system). Immersion techniques are well known in the art for increasing the numerical aperture of the projection system. As used herein, the term "immersion" does not mean that a structure such as a substrate must be submerged in a liquid. For example, there may be a liquid between the projection system and the substrate during exposure.

[0030]

[0039] Referring to Figures 1A and 1B, the illuminator IL receives the radiation beam from the radiation source SO. For example, if the radiation source SO is an excimer laser, the radiation source SO and the lithography apparatus 100, 100' may be separate physical entities. In such a case, the radiation source SO is not considered to form part of the lithography apparatus 100 or 100', and the radiation beam B is delivered from the radiation source SO to the illuminator IL using a beam delivery system BD (in Figure 1B) which includes, for example, appropriate guide mirrors and / or beam expanders. In other cases, for example, if the radiation source SO is a mercury lamp, the radiation source SO may be an integral part of the lithography apparatus 100, 100'. The radiation system may include the radiation source SO, the illuminator IL and / or the beam delivery system BD.

[0031]

[0040] The illuminator IL may include an adjuster AD (in Figure 1B) to adjust the angular intensity distribution of the radiated beam. Generally, it is possible to adjust at least the outer and / or inner radial range of the intensity distribution within the pupil plane of the illuminator (usually referred to as "σ-outer" and "σ-inner," respectively). Furthermore, the illuminator IL may include various other components (in Figure 1B), such as an integrator IN and a capacitor CO. The illuminator IL can be used to adjust the radiated beam B to give its cross-section the desired uniformity and intensity distribution.

[0032]

[0041] Referring to Figure 1A, the radiant beam B is incident on a patterning device (e.g., a mask) MA held on a support structure (e.g., a mask table) MT, and a pattern is formed by the patterning device MA. In the lithography apparatus 100, the radiant beam B is reflected from the patterning device (e.g., a mask) MA. After being reflected from the patterning device (e.g., a mask) MA, the radiant beam B passes through a projection system PS, which focuses the radiant beam B onto a target portion C of the substrate W. A second positioner PW and a position sensor IF2 (e.g., an interferometer device, a linear encoder, or a capacitance sensor) can be used to precisely move the substrate table WT (e.g., to position different target portions C within the path of the radiant beam B). Similarly, a first positioner PM and another position sensor IF1 can be used to precisely position the patterning device (e.g., a mask) MA relative to the path of the radiant beam B. The patterning device (e.g., mask) MA and the substrate W may be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2.

[0033]

[0042] Referring to Figure 1B, the radiation beam B is incident on a patterning device (e.g., mask MA) held on a support structure (e.g., mask table MT), and a pattern is formed by the patterning device. After passing through the mask MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of the substrate W. The projection system has a pupil PPU conjugate to the illumination system pupil IPU. The radiation portions arise from the intensity distribution in the illumination system pupil IPU, cross the mask pattern without being affected by diffraction, and create an image of the intensity distribution in the illumination system pupil IPU.

[0034]

[0043] The projection system PS projects an image of a mask pattern MP, which is formed on a photoresist layer coated on a substrate W by a diffracted beam generated from the mask pattern MP by radiation from the intensity distribution. For example, the mask pattern MP may include an array of lines and spaces. Radiative diffraction in the array, but not zero-order diffraction, generates stimulated diffracted beams whose direction is changed perpendicular to the lines. Non-diffracted beams (i.e., so-called zero-order diffracted beams) traverse the pattern without changing their propagation direction. The zero-order diffracted beams traverse the upper lens or upper lens group of the projection system PS upstream of the conjugate pupil PPU of the projection system PS to reach the conjugate pupil PPU. The portion of the intensity distribution in the plane of the conjugate pupil PPU associated with the zero-order diffracted beam is an image of the intensity distribution of the illumination system pupil IPU of the illumination system IL. The aperture device PD is, for example, located in the plane containing the conjugate pupil PPU of the projection system PS, or substantially located in that plane.

[0035]

[0044] The projection system PS is positioned to capture a zero-order diffraction beam, a primary-order diffraction beam, and / or higher-order diffraction beams (not shown) (e.g., using a lens or lens group L). In some embodiments, the resolution-enhancing effect of dipole illumination can be utilized by using dipole illumination to image a line pattern extending perpendicular to the line. For example, the primary-order diffraction beam interferes with the corresponding zero-order diffraction beam at the wafer W level to produce an image of the line pattern MP with the highest possible resolution and processing window (i.e., a combination of usable depth of focus and allowable exposure dose variation). In some embodiments, astigmatism can be reduced by providing an radiating pole (not shown) in the opposing quadrant of the illumination system pupil IPU. Furthermore, in some embodiments, astigmatism can be reduced by blocking the zero-order beam with a conjugate pupil PPU of the projection system associated with the radiating pole in the opposing quadrant. This is described in detail in U.S. Patent No. 7,511,799, issued March 31, 2009, which is incorporated herein by reference in its entirety.

[0036]

[0045] A second positioner PW and a position sensor IFD (e.g., an interferometer device, linear encoder, or capacitive sensor) can be used to precisely move the substrate table WT (for example, to position different target portions C within the path of the radiation beam B). Similarly, a first positioner PM and another position sensor (not shown in Figure 1B) can be used to precisely position the mask MA relative to the path of the radiation beam B (for example, after mechanically removing it from the mask library or during scanning).

[0037]

[0046] Typically, the movement of the mask table MT can be achieved using long-stroke modules (coarse positioning) and short-stroke modules (fine positioning) that form part of the first positioner PM. Similarly, the movement of the substrate table WT can also be achieved using long-stroke modules and short-stroke modules that form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the mask table MT may be connected to or fixed to a short-stroke actuator. The mask MA and substrate W may be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2. The (exemplary) substrate alignment marks occupy dedicated target areas, but the substrate alignment marks may also be placed in the space between target areas (known as scribe line alignment marks). Similarly, in situations where one or more dies are provided on the mask MA, the mask alignment marks may be placed between dies.

[0038]

[0047] The mask table MT and patterning device MA may be located inside the vacuum chamber V, and an in-vacuum robot IVR can be used to move the patterning device, such as a mask, inside and outside the vacuum chamber. Alternatively, if the mask table MT and patterning device MA are outside the vacuum chamber, an out-of-vacuum robot can be used for various transport operations, similar to the in-vacuum robot IVR. Both in-vacuum and out-of-vacuum robots can be calibrated for the smooth transfer of any payload (e.g., a mask) to a fixed kinematic mount at a relay station.

[0039]

[0048] Lithography devices 100 and 100' can be used in at least one of the following modes:

[0040]

[0049] 1. In step mode, the entire pattern applied to the radiation beam B is projected onto the target portion C at once (i.e., single static exposure) while the support structure (e.g., mask table) MT and substrate table WT are kept essentially stationary. Subsequently, the substrate table WT is shifted in the X and / or Y directions, thereby allowing exposure of another target portion C.

[0041]

[0050] 2. In scan mode, the support structure (e.g., mask table) MT and substrate table WT are scanned synchronously while the pattern applied to the radiation beam B is projected onto the target portion C (i.e., single dynamic exposure). The speed and direction of the substrate table WT relative to the support structure (e.g., mask table) MT can be determined by the (reduction) magnification and image inversion characteristics of the projection system PS.

[0042]

[0051] 3. In another mode, the support structure (e.g., mask table) MT is kept substantially stationary while the programmable patterning device is held, and the substrate table WT is moved or scanned, while the pattern applied to the radiation beam B is projected onto the target portion C. A pulsed radiation source SO can be used, and the programmable patterning device is updated as needed after each movement of the substrate table WT, or between consecutive radiation pulses during scanning. This operating mode can be easily applied to maskless lithography using programmable patterning devices such as programmable mirror arrays.

[0043]

[0052] Combinations and / or variations of the above-mentioned usage modes, or completely different usage modes, are also available.

[0044]

[0053] In some embodiments, the lithography apparatus 100 includes an extreme ultraviolet (EUV) source configured to generate a beam of EUV radiation for EUV lithography. Generally, the EUV source is configured within a radiation system, and a corresponding illumination system is configured to adjust the EUV radiation beam of the EUV source.

[0045]

[0054] In some embodiments, the lithography apparatus 100' includes a deep ultraviolet (DUV) source configured to generate a beam of DUV radiation for DUV lithography. Generally, the DUV source is configured within a radiation system, and a corresponding illumination system is configured to adjust the DUV radiation beam of the DUV source.

[0046]

[0055] Figure 2 shows a lithography apparatus 100 in more detail, including a source collector apparatus SO, an illumination system IL, and a projection system PS. The source collector apparatus SO is constructed and positioned to maintain a vacuum environment within the enclosed structure 220 of the source collector apparatus SO. An EUV radiant emission plasma 210 can be formed by a discharge-generating plasma source. In some embodiments, an excited tin (Sn) plasma is supplied (e.g., via a laser) to generate EUV radiation.

[0047]

[0056] The radiation emitted by the EUV radiation plasma 210 is transferred from the radiation source chamber 211 into the collector chamber 212 via an optional gas barrier or contaminant trap 230 (sometimes also called a contaminant barrier or foil trap) positioned within or behind the opening of the radiation source chamber 211. The contaminant trap 230 may include a channel structure. The contaminant trap 230 may include a gas barrier or a combination of a gas barrier and a channel structure. The contaminant trap or contaminant barrier 230 further described herein includes at least a channel structure.

[0048]

[0057] The collector chamber 212 may include a radiation collector CO, which may be a so-called grazing-incident collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation crossing collector CO can be reflected by the grating spectral filter 240 and focused to a virtual source point INTF. The virtual source point INTF is generally called an intermediate focus, and the source collector apparatus is arranged such that the intermediate focus INTF is located at or near the aperture 219 of the closed structure 220. The virtual source point INTF is an image of the EUV radiation-emitting plasma 210. The grating spectral filter 240 is used in particular to suppress infrared (IR) radiation.

[0049]

[0058] Next, the radiation crosses the illumination system IL, which may include a faceted field mirror device 222 and a faceted pupil mirror device 224, arranged to give the patterning device MA a desired angular distribution of the radiation beam 221 and a desired uniformity of radiation intensity in the patterning device MA. When the radiation beam 221 is reflected by the patterning device MA held by the support structure MT, a patterned beam 226 is formed, and the patterned beam 226 is imaged by the projection system PS via reflective elements 228, 229 onto a substrate W held by a wafer stage or substrate table WT.

[0050]

[0059] In general, the illumination optical unit IL and projection system PS may contain more elements than those shown in the figure. The grating spectral filter 240 may be optionally present depending on the type of lithography apparatus. Furthermore, there may be more mirrors than those shown in Figure 2; for example, the projection system PS may have 1 to 6 additional reflective elements compared to those shown in Figure 2.

[0051]

[0060] The collector-type CO system shown in Figure 2 is presented as a nested collector with grazing-type reflectors 253, 254, and 255, as just one example of a collector (or collector mirror). The grazing-type reflectors 253, 254, and 255 are axially symmetrically arranged around the optical axis O, and this type of collector-type CO system is preferably used in combination with a discharge-generating plasma source, often referred to as a DPP source.

[0052]

[0061] Exemplary lithographic cell

[0062] Figure 3 shows a lithographic cell 300, sometimes called a lithocell or cluster, relating to one embodiment. A lithography apparatus 100 or 100' may form part of the lithographic cell 300. The lithographic cell 300 may also include one or more devices for performing pre-exposure and post-exposure processes on a substrate. Conventionally, these include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a bake plate BK. A substrate handler or robot RO picks up the substrate from input / output ports I / O1 and I / O2, moves them between different processing units, and delivers them to the loading bay LB of the lithography apparatus 100 or 100'. These devices, often collectively called a track, are under the control of a track control unit TCU, which itself is controlled by a monitoring and control system SCS, which in turn controls the lithography apparatus via a lithography control unit LACU. In this way, different devices can be operated to maximize throughput and processing efficiency.

[0053]

[0063] Exemplary Tools

[0064] Figures 4A and 4B schematically show a tool 400 used to remove material from a wafer table according to some embodiments. In some embodiments, the tool 400 may include a pack 402 on which a grinding layer 404 is provided. Figure 4A shows a bottom view, and Figure 4B shows a cross-sectional view of the tool 400 according to some embodiments.

[0054]

[0065] In some embodiments, pack 402 can be formed from any suitable material. In some embodiments, pack 402 can be formed from a metal or insulating material. In some embodiments, pack 402 can be formed from a material having high hardness, such as silicon carbide or another high-hardness material.

[0055]

[0066] In some embodiments, the grinding layer 404 may be provided over the entire surface of the pack 402, or it may be provided only on a portion of the surface of the pack 402, as shown in Figure 4A. In some embodiments, the grinding layer 404 may include a disk-shaped region on the surface of the pack 402. In some embodiments, the grinding layer 404 may be patterned to cover multiple portions of the surface of the pack 402 while leaving other portions exposed. In some embodiments, the grinding layer 404 may be patterned to include lines that may be parallel to each other or intersect each other. In some embodiments, the grinding layer 404 may be patterned to include dots or other repeating structures that may be periodic or aperiodic or randomly arranged.

[0056]

[0067] In some embodiments, the grinding layer 404 may be formed from any material capable of removing material from the wafer table. In some embodiments, the grinding layer 404 may be formed from a material having a higher hardness than the material being removed. For example, if the material being removed is diamond-like carbon (DLC), the grinding layer 404 may be formed from diamond. In some embodiments, the diamond grinding layer may be formed from synthetic diamond provided, for example, on a pack 402. The synthetic diamond may be provided by chemical vapor deposition or any suitable process. The synthetic diamond may be single-crystal diamond or polycrystalline diamond such as microcrystalline diamond or nanocrystalline diamond. However, the present invention is not limited to the use of diamond for the grinding layer 404, but envisions the use of any material having sufficient hardness to remove material from the wafer table. In some embodiments, a suitable material may be selected based on the hardness of the material. For example, the grinding layer may be formed from a material having a hardness of 35 GPa or more. Therefore, alternative materials for the polishing layer 404 may include silicon carbide, boron nitride, carbon nitride, etc.

[0057]

[0068] Figure 4B shows a cross-sectional view of the tool 400 of Figure 4A used to remove material from a wafer table WT in some embodiments. In some embodiments, the pack 402 may be positioned on the wafer table WT so that the grinding layer 404 is in contact with the surface of the wafer table WT. In some embodiments, the grinding layer 404 can remove material from the surface of the wafer table WT by grinding the surface of the wafer table WT with the tool. The movement of the grinding tool may be controlled by the user's hand, a robotic arm, a processor coupled to a machine configured to move the tool, etc. The tool may be moved in a back-and-forth motion, a circular or orbital motion, a random orbital motion, or any similar motion. In some embodiments, the flatness of the wafer table or the amount or level of material removed may be monitored at predetermined time intervals or random periods throughout the grinding process. On the other hand, in some embodiments, the flatness of the wafer table or the amount of material removed may not be monitored, and instead, the grinding may follow predetermined parameters designed to make the wafer table substantially flat. In some embodiments, by grinding the wafer table WT with the tool 400, surface defects that accumulate on the wafer table WT during lithography operations and substantially affect the flatness of the wafer placed on the wafer table WT can be eliminated.

[0058]

[0069] As shown in Figures 5A and 5B, the grinding process described in some embodiments may result in the formation of material on the grinding surface of the tool. In particular, as shown in Figure 5A, the tool 500 includes a grinding surface 504. As described above, while the tool 500 is being used to remove material from a wafer table WT, material 510 may form on the grinding surface 504. Figure 5B is an enlarged portion of Figure 5A and shows the formation of material 510 on the surface of the grinding layer 504. In some embodiments, the material 510 may be a gum-like residue such as DLC, which degrades the performance of the tool over time. For this reason, the inventors have devised a method to reduce the accumulation of material 510 on the surface of the grinding layer 504.

[0059]

[0070] Figure 6 illustrates a method 600 for fabricating a tool according to some embodiments. In step 602, a pack is provided. In step 604, a grinding layer is formed on at least one surface of the pack. In step 606, the surface of the grinding layer is treated. In some embodiments, the treatment of the grinding layer can form covalent atoms on the surface of the grinding layer. In some embodiments, the covalent atoms on the surface of the grinding layer may be configured to resist clogging of the grinding layer by material removed from the wafer table.

[0060]

[0071] Figure 7 illustrates a tool 700 formed according to the method 600 shown in Figure 6. At the top of Figure 7, a pack 702 is provided, and a grinding layer 704 is formed on the surface of the pack 702. At this time, as shown at the top of Figure 7, the grinding layer 704 may contain various hydrogen, oxygen and / or hydroxides 706 bonded to the surface of the grinding layer 704. After surface treatment, as shown at the bottom of Figure 7, the hydrogen, oxygen and / or hydroxides 706 are replaced by atoms 708 covalently bonded to the surface of the grinding layer 704.

[0061]

[0072] In some embodiments, as shown at the bottom of Figure 7, atom 708 may be fluorine. However, the present invention is not limited to the use of fluorine and envisions the use of any suitable atom that reduces adhesion between the grinding layer 704 and the material removed from the wafer table. For example, in some embodiments, atom 708 may include one or more of chlorine, bromine, or iodine.

[0062]

[0073] In some embodiments, when fluorine is used for atom 708, the surface of the grinding layer 704 may be treated, for example, by a plasma fluorination process, according to techniques well known to those skilled in the art. Alternatively, in some embodiments, the grinding layer 704 may be treated with a perfluoroalkyl monolayer, which may be prepared by reacting a functionalized trialkoxysilane with the surface of the grinding layer 704. These surface treatments are merely illustrative and do not limit the invention to the use of any surface treatment that appropriately replaces hydrogen, oxygen, and / or hydroxide 706 on the grinding surface 704 with the covalent atom 708 according to the invention. Furthermore, in some embodiments, the grinding layer 704 may be prepared using other surface treatments. In some embodiments, the grinding layer 704 may be hydroxylated before being treated as described above.

[0063]

[0074] In some embodiments, adhesion between the grinding layer and the material to be removed can be reduced by minimizing the bonding between the grinding layer and the material to be removed. For example, a grinding layer lacking the surface treatment according to the present invention would contain hydrogen, oxygen, and / or hydroxides on its surface. Such hydrogen, oxygen, and / or hydroxides enable bonding between the grinding layer and the material to be removed not only through relatively weak van der Waals forces but also through hydrogen bonding, and this bonding can result in capillary forces that draw the material to be removed into the gaps of the grinding layer. In contrast, a grinding layer treated according to embodiments of the present invention minimizes hydrogen bonding (and capillary forces), resulting in only weak van der Waals forces existing between the treated grinding layer and the material to be removed. Thus, embodiments of the present invention provide a grinding layer that resists clogging by material to be removed from the wafer table by reducing intermolecular bonding between the treated grinding layer and the material to be removed.

[0064]

[0075] The method steps in Figure 6 can be performed in any possible order, and not all steps need to be performed. For example, the grinding layer may be processed before being placed on the pack. Alternatively, the processed grinding layer may be used to remove the material from the wafer table WT without being initially placed on the pack, for example, using paper or another suitable substrate. Furthermore, the method steps in Figure 6 described above are merely an example of the steps and are not limiting. That is, further method steps and functions are conceivable based on the embodiments described with reference to Figures 1-7.

[0065]

[0076] Various embodiments of the tool and method are disclosed in the following numbered clause list. Further functions, features, and exemplary technical solutions of the disclosure are described below with respect to clauses that may be requested in any combination at the discretion of the party. 1. A tool for removing material from the surface of a wafer table, Pack and, The pack includes an abrasive layer provided on at least one surface of the pack, The surface of the grinding layer contains covalently bonded atoms, and as a result, the grinding layer resists clogging by the material being removed from the tool. 2. Covalent atoms include fluorine, as described in Clause 1. 3. The abrasive layer of the tool, as described in Clause 1, contains diamond having a hardness of 35 GPa or more. 4. The covalent atom contains fluorine and is bonded to diamond, as described in Clause 3. 5. The materials to be removed include diamond-like carbon (DLC), as specified in Clause 1. 6. A method for forming a tool for removing material from a wafer table, A grinding layer is provided on the surface of the pack, The surface of the grinding layer is treated to form covalent atoms on the surface of the grinding layer, and as a result, the grinding layer resists clogging by the material being removed. Methods that include... 7. The method according to Clause 6, wherein the treatment for forming a covalent atom includes the treatment for forming a covalent atom containing a fluorine atom. 8. The method according to Clause 7, wherein the surface treatment of the grinding layer includes fluorinating the surface of the grinding layer using plasma fluorination. 9. The method according to Clause 7, wherein the surface treatment of the grinding layer includes fluorinating the surface of the grinding layer using a perfluoroalkyl monolayer. 10. The method according to Clause 9, wherein the preparation of a perfluoroalkyl monolayer comprises reacting a functionalized trialkoxysilane with a diamond surface. 11. The method according to Clause 7, wherein the surface treatment of the grinding layer includes replacing hydrogen, oxygen and / or hydroxides in the grinding layer with fluorine before treating the surface of the grinding layer. 12. The method according to Clause 6, further comprising treating the surface of the abrasive layer by hydroxylating the surface of the abrasive layer before reacting it with the functionalized trialkoxysilane. 13. The method according to Clause 6, wherein providing an abrasive layer includes forming a diamond having a hardness of 35 GPa or more. 14. The method according to Clause 13, wherein the surface treatment of the abrasive layer includes covalently bonding fluorine atoms to the diamond. 15. Removing material from a wafer table, including removing diamond-like carbon (DLC), as described in Clause 6. 16. A method for removing material from a wafer table, comprising grinding the wafer table using the tools described in Clause 1 to remove the material from the wafer table. 17. A method for removing material from a wafer table, comprising grinding the wafer table using a tool formed in accordance with the method described in Clause 6, thereby removing the material from the wafer table.

[0066]

[0077] While some aspects of this disclosure are described in the context of lithography equipment in the manufacture of ICs, it should be understood that the lithography equipment described herein may also be used in other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memory, flat panel displays, LCDs, thin-film magnetic heads, etc. In the context of these alternative applications, it will be recognized by those skilled in the art that where the terms “wafer” or “die” are used herein, they may be considered specific examples of the more general terms “substrate” or “target portion,” respectively. The substrate may be processed before or after exposure, for example, with a track unit (typically a tool for coating a layer of resist onto the substrate and developing the exposed resist) and / or a metrologic unit. The aspects disclosed herein can be appropriately applied to the above-mentioned and other substrate processing tools. Furthermore, the substrate may be processed multiple times, for example, to produce a multilayer IC, and therefore, the term "substrate" as used herein may also refer to a substrate that already contains multiple processed layers.

[0067]

[0078] The language and terminology used herein are for illustrative purposes only and not limiting; therefore, it should be understood that the language and terminology used herein should be interpreted by those skilled in the art in the context of the teachings provided herein.

[0068]

[0079] The present disclosure has been described above using functional building blocks that illustrate implementations of specific functions and their relationships. In this specification, the boundaries of these functional building blocks are arbitrarily defined for the sake of explanation. Alternative boundaries may be defined as long as the specific functions and their relationships are adequately implemented. The above descriptions of specific embodiments fully disclose the general nature of this disclosure and, therefore, by applying the knowledge contained in the capabilities of the art, such specific embodiments can be readily modified and / or adapted to various uses without excessive experimentation and without deviating from the general concepts of this disclosure. Accordingly, such adaptations and modifications are intended to be within the meaning and equivalents of the disclosed embodiments, based on the teachings and advice presented herein.

[0069]

[0080] It should be understood that the "Modes for Carrying Out the Invention" section, rather than the "Summary of the Invention" and "Abstract" sections, is intended to be used when interpreting the claims. The "Summary of the Invention" and "Abstract" sections may describe one or more embodiments of the disclosure as envisioned by the inventor, but may not necessarily describe all embodiments, and are therefore not intended to limit the scope of the disclosure and the attached claims in any way. The breadth and scope of the subject matter to be protected should not be limited by any of the embodiments described above, but should be defined according to the following claims and their equivalents.

Claims

1. A tool for removing material from the surface of a wafer table, Pack and, The pack includes an abrasive layer provided on at least one surface of the pack, The surface of the grinding layer contains atoms covalently bonded to the surface of the grinding layer, and as a result, the grinding layer resists clogging by the material being removed, in the tool.

2. The tool according to claim 1, wherein the covalent atom includes fluorine.

3. The abrasive layer contains diamond having a hardness of 35 GPa or more. The tool according to claim 1, wherein the covalent atom contains fluorine and is bonded to the diamond.

4. The tool according to claim 1, wherein the material to be removed includes diamond-like carbon (DLC).

5. A method for forming a tool for removing material from a wafer table, A grinding layer is provided on the surface of the pack, The surface of the grinding layer is treated to form covalent atoms on the surface of the grinding layer, and as a result, the grinding layer resists clogging by the material being removed. Methods that include...

6. The method according to claim 5, wherein the treatment for forming a covalent atom includes the treatment for forming a covalent atom containing a fluorine atom.

7. The method according to claim 6, wherein the treatment of the surface of the grinding layer includes fluorinating the surface of the grinding layer using plasma fluorination.

8. The treatment of the surface of the grinding layer includes fluorinating the surface of the grinding layer using a perfluoroalkyl monolayer, The method according to claim 6, wherein the preparation of the perfluoroalkyl monolayer includes reacting a functionalized trialkoxysilane with the diamond surface.

9. The method according to claim 6, wherein treating the surface of the grinding layer includes replacing hydrogen, oxygen and / or hydroxides in the grinding layer with fluorine before treating the surface of the grinding layer.

10. The method according to claim 5, wherein the treatment of the surface of the grinding layer further comprises hydroxylating the surface of the grinding layer before reacting it with a functionalized trialkoxysilane.

11. The method according to claim 5, wherein providing the abrasive layer includes forming a diamond having a hardness of 35 GPa or more.

12. The method according to claim 11, wherein the treatment of the surface of the grinding layer includes covalently bonding fluorine atoms to the diamond.

13. The method according to claim 5, wherein removing the material from the wafer table includes removing diamond-like carbon (DLC).

14. A method for removing material from a wafer table, comprising grinding the wafer table using the tool described in claim 1 to remove the material from the wafer table.

15. A method for removing material from a wafer table, comprising grinding the wafer table using a tool formed according to the method of claim 5, thereby removing the material from the wafer table.

Images