Substrate holder for use in photolithography equipment and method for manufacturing substrate holder

Abstract

This document describes a method for producing a substrate holder for use in a photolithography apparatus, the substrate holder comprising a plurality of protrusions projecting from the substrate holder, each protrusion having a distal surface configured to engage a substrate. The method includes applying a coating of a wear-resistant material to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. The application of the coating includes adjusting the radio frequency (RF) power of an RF electrode in the range of 100 W to 1000 W to generate plasma; and exposing the one or more protrusions in a chamber to a precursor gas, wherein the precursor gas is hexane, at a gas flow rate between 20 sccm and 300 sccm.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 036,028, filed June 8, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a substrate holder for use in a photolithography apparatus and a method for manufacturing the substrate holder. Background Technology

[0004] A lithography apparatus is a machine configured to coat a substrate with a desired pattern. Lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithography apparatus can project a pattern (also often referred to as a “design layout” or “design”) from a patterning apparatus (e.g., a mask) onto a radiation-sensitive material (resist) layer disposed on a substrate (e.g., a wafer).

[0005] As semiconductor manufacturing processes have advanced, the size of circuit elements has shrunk over the decades, while the number of functional elements, such as transistors, per device has steadily increased, following a trend commonly known as "Mohr's Law." To meet Mohr's Law, the semiconductor industry is seeking technologies capable of producing increasingly smaller features. Photolithography equipment uses electromagnetic radiation to project patterns onto a substrate. The wavelength of this radiation determines the minimum size of the features patterned on the substrate. Typical wavelengths currently used are 365 nm (i-line), 248 nm (KrF), 193 nm (ArF), and 13.5 nm (EUV).

[0006] In photolithography equipment, the substrate to be exposed (which may be referred to as the production substrate) is held on a substrate holder (sometimes called a wafer stage). The substrate holder is movable relative to the projection system. The substrate holder typically comprises a solid body made of a rigid material and having dimensions in a plane similar to the production substrate to be supported. The substrate-facing surface of the solid body is provided with multiple protrusions (called nodules). The distal surfaces of the nodules conform to the flat plane and support the substrate. The nodules offer several advantages: contaminant particles on the substrate holder or the substrate are likely to fall between the nodules and therefore do not cause substrate deformation; machining the nodules to conform their ends to the plane is easier than flattening the surface of the solid body; and the properties of the nodules can be adjusted, for example, to control the clamping of the substrate.

[0007] However, the protrusions of the substrate holder wear down during use, for example, due to repeated loading and unloading of the substrate. Uneven wear of the protrusions can lead to unevenness of the substrate during exposure, which may result in a reduction in the process window and, in extreme cases, imaging and / or overlap errors. The substrate holder is expensive to manufacture due to its very precise manufacturing specifications, making it desirable to extend its service life. Summary of the Invention

[0008] In one embodiment, a method for manufacturing a substrate holder for use in a photolithography apparatus is provided. The substrate holder includes a plurality of protrusions projecting from the substrate holder, each protrusion having a distal surface configured to engage a substrate. The method includes applying a coating of a wear-resistant material to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. The application of the coating includes adjusting the radio frequency (RF) power of an RF electrode in the range of 100 W to 1000 W to generate plasma; and exposing the one or more protrusions in a chamber to a precursor gas at a gas flow rate between 20 sccm and 300 sccm, the precursor gas being hexane.

[0009] Furthermore, in one embodiment, a method for manufacturing a substrate holder for use in a photolithography apparatus is provided. The substrate holder includes a plurality of protrusions projecting from the substrate holder, and each protrusion has a distal surface configured to engage with a substrate. The method includes applying a coating of a wear-resistant material to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. The application of the coating includes adjusting the radio frequency (RF) power of an RF electrode in the range of 50 W to 750 W to generate plasma; and exposing the one or more protrusions in a chamber to a precursor gas at a gas flow rate between 10 sccm and 100 sccm, the precursor gas being acetylene.

[0010] Furthermore, in one embodiment, a substrate holder for use in a photolithography apparatus and configured to support a substrate is provided. The substrate holder includes a body having a main surface and a plurality of protrusions projecting from the main surface. Each protrusion has a distal surface configured to engage the substrate. The distal surface of the protrusion is substantially conformal to a support plane and configured to support the substrate; and one or more of the protrusions have their distal surfaces coated with a wear-resistant material having a hardness in the range of 20 GPa to 27 GPa or 25 GPa to 35 GPa and a corrosion rate in the range of 0.1 nm / hr to 2 nm / hr. The corrosion rate is measured in a dilute NaCl solution in a three-electrode electrochemical cell by chronoamperometry, the three-electrode electrochemical cell having a potential difference of approximately +2.5 V between the working electrode and the counter electrode and applying the potential difference relative to a reference electrode. Attached Figure Description

[0011] The embodiments will now be described by way of example only with reference to the accompanying drawings, in which:

[0012] Figure 1 This is a block diagram of the various subsystems of the lithography system according to an embodiment.

[0013] Figure 2A The illustration shows a substrate or wafer loaded onto a substrate holder (also known as a wafer stage (WT)) via an electrostatic clamp (ESC) according to an embodiment, the substrate being supported on an e-pin, i.e., a push rod, in the unloaded position;

[0014] Figure 2B The illustration shows a substrate in a loading position on a substrate holder according to an embodiment;

[0015] Figures 2C to 2F The diagram illustrates the sequence of loading the substrate onto the substrate holder according to an embodiment;

[0016] Figure 3A The illustration shows a substrate mounted on a substrate holder according to an embodiment, the surface of which includes protrusions with a certain roughness on which the substrate is placed;

[0017] Figure 3B According to the embodiments Figure 3A Example protrusions of substrate retainers;

[0018] Figure 4 This is a flowchart of a method for manufacturing a substrate holder according to an embodiment;

[0019] Figure 5 The illustration shows an example plasma-enhanced chemical vapor deposition setup according to an embodiment;

[0020] Embodiments will now be described in detail with reference to the accompanying drawings, which are provided as illustrative examples to enable those skilled in the art to practice these embodiments. It should be noted that the following figures and examples are not intended to limit the scope to a single embodiment, but rather to make other embodiments possible by means of interchange of some or all of the elements described or illustrated. Where possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. Where certain elements of these embodiments can be implemented partially or completely using known components, only those portions of these known components necessary for understanding the embodiments will be described, and detailed descriptions of other portions of these known components will be omitted so as not to obscure the description of the embodiments. In this specification, embodiments showing a singular number of components should not be considered limiting; rather, unless expressly stated otherwise herein, the scope is intended to cover other embodiments comprising a plurality of the same components, and vice versa. Furthermore, unless so expressly stated, the applicant does not intend for any terminology in this specification or claims to be relegated to an uncommon or particular meaning. Additionally, the scope covers current and future known equivalents of components mentioned herein by means of illustrations. Detailed Implementation

[0021] While features are described herein with reference to illustrative embodiments of specific applications, it should be understood that the invention is not limited thereto. Those skilled in the art, upon receiving the teachings presented herein, will recognize additional modifications, applications, and embodiments within their scope, as well as additional areas where the invention will have significant utility.

[0022] In this disclosure, the terms "mask" or "patterning apparatus" as used herein can be broadly interpreted as a general patterning apparatus that can be used to impart a patterned cross-section to an incident beam, the patterned cross-section corresponding to a pattern to be generated in a target portion of a substrate; the term "optical valve" can also be used in this context. Examples of other such patterning apparatuses besides classical masks (transmission or reflection; binary, phase-shifting, hybrid, etc.) include:

[0023] - Programmable mirror arrays. An example of such a device is a matrix-addressable surface having a viscoelastic control layer and a reflective surface. The underlying principle of such a device is (for example): addressable regions of the reflective surface reflect incident radiation as diffracted radiation, while unaddressed regions reflect incident radiation as non-diffracted radiation. With the use of a suitable filter, the non-diffracted radiation can be filtered out from the reflected beam, leaving only the diffracted radiation; in this way, the beam becomes patterned according to the addressing pattern of the matrix-addressable surface. Suitable electronics can be used to perform the desired matrix addressing. More information about such mirror arrays can be found, for example, from U.S. Patent Nos. 5,296,891 and 5,523,193, which are incorporated herein by reference.

[0024] - Programmable LCD array. An example of such a construction is given in U.S. Patent No. 5,229,872, which is incorporated herein by reference.

[0025] As a brief introduction, Figure 1 The illustration shows an exemplary photolithography projection apparatus 10A. The main components are: a radiation source 12A, which may be a deep ultraviolet excimer laser source or other types of sources including extreme ultraviolet (EUV) sources (as discussed above, the photolithography projection apparatus itself does not need to have a radiation source); irradiation optics, which define partial coherence (expressed as standard deviation) and may include optics 14A, 16Aa, and 16Ab that shape the radiation from source 12A; a pattern forming apparatus 18A; and a transmission optics 16Ac that projects an image of a pattern from the pattern forming apparatus onto a substrate plane 22A. An adjustable filter or aperture or aperture stop 20A at the pupil plane of the projection optics can define the range of beam angles irradiating onto the substrate plane 22A, wherein the largest possible angle defines the numerical aperture NA of the projection optics as sin(Θ). max ).

[0026] In a photolithography projection apparatus, a source provides illumination (i.e., light); projection optics guide and shape the illumination via a patterning apparatus and project the illumination onto a substrate. Here, the term "projection optics" is broadly defined as any optical component that can vary the wavefront of the radiation beam. For example, a projection optics may include at least some of components 14A, 16Aa, 16Ab, and 16Ac. The spatial image (AI) is the distribution of radiation intensity at the substrate level. A resist layer on the substrate is exposed, and the spatial image is transferred to the resist layer as a potential "resist image" (RI). The resist image (RI) can be defined as the spatial distribution of the solubility of the resist in the resist layer. A resist model can be used to calculate the resist image from the spatial image, an example of which can be found in commonly assigned U.S. Patent Application No. 12 / 315,849, the disclosure of which is hereby incorporated by reference in its entirety. The resist model relates only to the properties of the resist layer (e.g., the effects of chemical processes occurring during exposure, PEB, and development). The optical properties of a photolithographic projection apparatus (e.g., the properties of the source, pattern forming apparatus, and projection optics) define the spatial image. Since the pattern forming apparatus used in a photolithographic projection apparatus can be modified, it is desirable to separate the optical properties of the pattern forming apparatus from the optical properties of the rest of the photolithographic projection apparatus, which includes at least the source and projection optics.

[0027] In this document, the terms “radiation” and “beam” are used to cover all types of electromagnetic radiation, including ultraviolet radiation (e.g., with wavelengths of 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm) and EUV (extreme ultraviolet radiation, e.g., with wavelengths in the range of 5 nm to 20 nm).

[0028] Furthermore, photolithography projection apparatuses can belong to the type having one or more substrate holders, such as two substrate holders (and / or one or more patterning stages, such as two patterning stages). In these "multi-platform" apparatuses, additional stages can be used in parallel, or preparation steps can be performed on one or more stages while one or more other stages are used for exposure. Dual-platform photolithography projection apparatuses are described, for example, in US 5,969,441, which is incorporated herein by reference.

[0029] In photolithography equipment (e.g., Figure 1 In this process, the substrate to be exposed (which may be referred to as the production substrate) is held on a substrate holder (sometimes called a wafer stage or substrate holder). The substrate holder (WT) is designed to accurately position the substrate during exposure. A substrate stage (e.g., Figure 2A and Figure 3AThe WT in the figure can be movable relative to the projection device. The substrate holder typically comprises a solid body made of a rigid material and having dimensions in the XY plane similar to the production substrate to be supported. The substrate-facing surface of the solid body is provided with multiple protrusions or projections (called nodules). Nodules (see...) Figure 3B The distal surface of the tab conforms to a flat plane and supports the substrate. Tabs offer several advantages: contaminant particles on the substrate holder or the substrate are likely to fall between the tabs and therefore do not cause deformation of the substrate; machining the tabs to conform to a flat plane at their ends is easier than flattening the surface of a solid; and the properties of the tabs can be adjusted, for example, to control the clamping of the substrate. In embodiments, the tabs reduce the contact area, thereby reducing friction and adhesion between the substrate holder WT and the substrate W.

[0030] However, the protrusions of the substrate holder wear down during use, for example, due to repeated loading and unloading of the substrate. Uneven wear of the protrusions results in unevenness of the substrate during exposure (e.g., surface profiles exceeding specifications in the z-direction), which can lead to a reduction in the process window and, in extreme cases, imaging and / or overlap errors. Due to the very precise manufacturing specifications, the substrate holder is expensive to manufacture, thus increasing its service life is desirable.

[0031] Some substrate holders may have a diamond-like carbon (DLC) coating on the body, typically SiC or SiSiC. However, wear, oxidation, and unstable friction of the DLC-coated protrusions are considered important / significant problems causing substrate holder degradation.

[0032] Therefore, it is desirable to coat the substrate holder, or at least the protrusions of the substrate holder, with a coating such as diamond or other ultra-hard materials. However, available CVD manufacturing techniques, such as those used for diamond growth, require high deposition temperatures (400°C to 1200°C), which can generate high thermal stress and thus cause the substrate holder to bend. This, in turn, necessitates additional time-consuming manufacturing steps to ensure the substrate holder meets flatness specifications.

[0033] Figure 2A and Figure 2BThe illustration shows the loading and unloading of a substrate W onto a substrate holder WT using a wafer transport device WH. The substrate holder WT typically has multiple protrusions for supporting the substrate W. For example, more than 10,000 protrusions are disposed on the top of the substrate holder WT, contacting the substrate W. When the substrate W is initially loaded onto the substrate holder WT in preparation for exposure, the substrate W is supported by three or more ejector pins (e-pins, i.e., ejector rods) that hold the substrate W. The wafer transport device WH re-tracks when the substrate is positioned on the e-pins. To hold and support the substrate W on the substrate holder WT during step-through and scanning, the substrate W is clamped onto the protrusions (e.g., see [link to relevant documentation]). Figure 2A and Figure 3A The clamping mechanism may include, for example, vacuum force in DUV or electrostatic force in EUV.

[0034] Although the substrate W is held by the e-pin, the substrate's own weight and the stress from the treated layers and back-side coating will cause the substrate W to deform, for example, become convex or concave. To load the substrate W onto the substrate holder WT, the e-pin retracts, such that the substrate W is supported by the protrusion of the substrate holder WT. As the substrate W is lowered onto the protrusion of the substrate holder WT, the substrate W will contact at some locations (e.g., near the edge) before contacting at other locations (e.g., near the center). (See protrusion). Figures 2C to 2F Any friction between the substrate W and its lower surface can prevent the substrate from fully relaxing into a flat, stress-free state. This could lead to focusing and overlap errors during exposure of the substrate W.

[0035] The increasingly thick layers on the wafer create an arched, or bowed, wafer shape; for example, the wafer may bend to 400 μm. These deviations result in overlapping defects on the wafer due to misalignment and deformed patterns. When the arched wafer is loaded and clamped on the substrate holder WT, in-plane stress is introduced. Figures 2C to 2F The illustration shows an example loading sequence of the substrate W and the friction between the protrusion and the substrate W. The sequence of loading the wafer from the e-pin to the substrate holder WT or electrostatic clamp (ESC) is also shown. For example, the wafer W on the e-pin travels downwards to the substrate stage WT (see [link to documentation]). Figure 2C The arc-shaped wafer W' contacts the substrate holder WT at its edge (see...). Figure 2D The wafer W is clamped onto the substrate holder WT (see...). Figure 2E And the stress is locked into the wafer. Figure 2FIn such cases, the combination of wafer shape, coefficient of friction, and normal force causes WLG problems, such as positioning errors relative to a reference grid.

[0036] The substrate holder WT is typically made of a ceramic material, such as silicon carbide (SiC) or SiSiC (a material containing SiC particles within a silicon matrix). This ceramic material can be easily machined into the desired shape using conventional manufacturing methods. The ceramic material may wear down rapidly when the substrate is loaded and unloaded from the substrate holder WT. The relatively high coefficient of friction of the ceramic material also prevents the substrate W from relaxing into a flat, stress-free state when loaded onto the substrate holder WT.

[0037] refer to Figure 3A and Figure 3B In one embodiment, one or more protrusions 310 of the substrate holder WT include a protrusion body 312 coated with a wear-resistant material (e.g., diamond-like carbon (DLC)). This coating 311 is wear-resistant and reduces friction between the substrate holder and the substrate W. In one example, DLC may be deposited directly onto the protrusions of the substrate holder WT. In another example, DLC may be deposited directly onto the entire substrate holder WT. DLC deposition is possible at temperatures below 300°C. Temperatures above 300°C may damage the substrate holder.

[0038] In an embodiment, coating 311 may include a first coating and a second coating of a wear-resistant material (e.g., DLC). The first and second coatings may include features similar to those of coating 311. The first coating may be deposited directly onto the substrate holder such that the substrate holder is coated with the first coating. The second coating may be deposited onto the first coating. The second coating may include a different composition and / or different properties than the first coating as described herein.

[0039] The inventors have recognized that, using existing coating techniques, the performance of such DLC-coated substrate holders does not meet substrate performance specifications (e.g., flatness, focal length, and overlap) (wear and corrosion of the substrate holder are the root causes of focal length and overlap problems at the substrate). The DLC deposited on the substrate holder WT (those areas arranged to contact the substrate) wears approximately 10 times faster than expected, thus requiring re-grinding / repolishing and readjustment of the substrate holder much earlier than the desired operating time. In embodiments, the performance of the substrate holder WT is measured using parameters such as wafer load grid (WLG) and flatness.

[0040] Deterioration of the substrate holder (WT) results in a limited lifespan, thus potentially requiring early replacement or surface repair. The substrate holder can wear down in terms of the flatness and smoothness of the protrusion top, for example, creating a floral pattern. This degradation can originate from chemical wear, mechanical wear, or a combination thereof. Current substrate holder WT designs with DLC coatings exhibit significant WLG drift and flatness degradation. For example, due to wear, the WLG drift rate is 20 nm per million substrate passes, and the flatness degradation is 10 nm per million substrate passes. In this embodiment, wear refers to the combination of all types of wear.

[0041] In an embodiment, the coating 311 is configured to improve substrate holder performance by reducing mechanical and chemical wear caused by high coating hardness and corrosion inertness. The improved DLC coating process or improved DLC coating as described in this disclosure reduces WLG drift from, for example, the current value of 20 nm per million substrate passes to below 15 nm per million substrate passes. The DLC coating depicted herein can also improve, for example, flatness degradation originating from mechanical wear. For example, flatness degradation can also be reduced from 10 nm per million substrate passes to below 7 nm per million substrate passes.

[0042] According to an embodiment, flatness degradation occurs due to non-uniform wear of the DLC coating caused by a large number of substrate clamping and unclamping operations. The mechanics of the process exerts higher lateral displacement on the periphery of the substrate holder WT, resulting in higher edge wear. This non-uniform wear of the coating is the cause of substrate holder degradation and flatness, reducing process yield and leading to the need for earlier substrate holder replacement and machine downtime. Therefore, the coating process should be tailored to produce a coating composition with high hardness and wear resistance to minimize edge wear and maximize substrate holder WT life.

[0043] According to the embodiments, a low coefficient of friction is required to minimize wLG. Most commercially available coatings (e.g., DLC coatings) can meet specifications during the early stages of their application on the WT protrusion. However, increasing the number of substrate passes removes the roughness of the top surface of the protrusion, thus causing the substrate to adhere to the substrate WT via, for example, van der Waals forces and capillary forces. This chemical adhesion of the substrate to the top surface of the protrusion causes an increase in the coefficient of friction and wLG. The increase in wLG directly translates into an overlap problem, thereby reducing process yield and forcing earlier field replacement of the substrate holder WT.

[0044] This disclosure describes an improved coating composition and a method for coating a substrate holder. For example, coating can be performed using a parallel-plate plasma-enhanced chemical vapor deposition (PE-CVD) reactor. Existing PE-CVD setups typically involve an RF electrode with an RF power of approximately 1500 W and a hexane gas flow rate of 300 sccm or greater. However, using such a process, existing ac:H DLC coatings exhibit a hardness of approximately 21 GPa or less, and a corrosion rate of 2.7 nm / h or higher. According to this embodiment, an improved coating hardness of 23 GPa or greater and a corrosion rate of 1.1 nm / h or less are obtained.

[0045] In the embodiment, reference Figure 4 The fabrication process for coating the substrate is described in further detail below. Through a series of experiments, it has been found that reducing the RF power increases the film's corrosion resistance to a given gas flow rate when using hexane as the source gas. Moreover, when this reduction in RF power is coupled with a reduction in gas flow rate, the resulting film exhibits excellent corrosion resistance and high hardness values. As discussed herein, the substrate holder WT includes a plurality of protrusions projecting from the substrate holder (e.g., see...). Figure 3B Each protrusion has a distal surface configured to engage with the substrate.

[0046] In an embodiment, operation P401 includes coating a wear-resistant material onto the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. In an embodiment, operation P401 includes several sub-operations, such as P403 and P405.

[0047] In an embodiment, operation P403 includes adjusting the radio frequency (RF) power of the RF electrode within a range of 100W to 1000W for plasma generation. In an embodiment, operation P403 includes exposing one or more protuberances within a chamber to a precursor gas, said precursor gas being hexane, at a gas flow rate between 20 sccm and 300 sccm (e.g., 20 to 200 sccm). In an embodiment, the chamber has a geometry described by the distances between different components within the chamber. For example, the distances or diameters within the chamber (e.g., see...) Figure 5 D1), the distance between the top of the chamber and the turntable TT (e.g., see D1), and the distance between the top of the chamber and the turntable TT (e.g., see D1). Figure 5 (D2 in the figure), the distance between the substrate holder and the gas distribution line (see D2 in the figure), and the distance between the substrate holder and the gas distribution line (see D2 in the figure). Figure 5 (D3 in the example), or other suitable geometric measurements. In the example, in Figure 5In this example, distance D1 can be approximately 23 inches, distance D2 can be approximately 6 inches, and distance D3 can be approximately 5.25 inches. It is understood that the geometry of the chamber is presented as an example and other chamber geometries may be used.

[0048] In an embodiment, the coating operation P401 further includes adjusting one or more process parameters, said one or more process parameters including at least one of the following: wherein the chamber in which the substrate holder is placed is located, in a 1×10 -3 Up to 5×10 -2 A vacuum level in the range of mbar; or a turntable speed in the range of 5 rpm to 100 rpm for a stage on which the substrate holder is placed.

[0049] In an embodiment, the coating having a wear-resistant material causes the distal surfaces of one or more protrusions to also have at least one of the following properties: a coefficient of friction of the resulting coating in the range of 0.05 to 0.5; a surface of the resulting coating having high spots of less than 10 nm and thickness uniformity across the multiple protrusions of the substrate holder in the range of 10% above and below the coating thickness of 300 mm or less in diameter; or a wafer loading grid in the range of 0.1 nm to 1.5 nm, the wafer loading grid being the relative positioning error of the substrate relative to a reference.

[0050] In this embodiment, the wear-resistant material is a type of diamond-like carbon (DLC). In this embodiment, DLC includes: (i) DLC doped with B, N, Si, O, F, or S; and / or (ii) DLC doped with metals such as Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au, or Ag. In this embodiment, combinations of DLC materials can be used to form the wear-resistant material.

[0051] In an embodiment, the wear-resistant coating imparts a hardness property of the distal surface of the one or more protrusions in the range of 20 GPa to 27 GPa and a corrosion rate property in the range of 0.1 nm / hr to 1.5 nm / hr, the corrosion rate being characterized by chronoamperometry in a three-electrode electrochemical cell having a potential difference of approximately +2.5 V between the working and counter electrodes, and the potential difference being applied relative to a reference electrode in a dilute NaCl solution. The coating using hexane may comprise 50 to 65% sp. 3 And 25 to 35% hydrogen.

[0052] In one embodiment, the hardness is measured by a nanoindentation method, wherein the measurement is performed using a Berkovich diamond indenter with a nano-DMA transducer and the indentation depth is maintained below 10% of the coating thickness. In another embodiment, the coating thickness is between 200 nm and 3 μm.

[0053] In an embodiment, method 400 further includes operation P410, which includes cleaning the plurality of protrusions with argon (Ar) gas prior to applying the coating. In an embodiment, the cleaning step includes generating plasma using Ar gas at an RF power of approximately 1000 W; adjusting the Ar flow rate at 75 sccm for 100 seconds. In an embodiment, method 400 further includes gradually decreasing the Ar flow rate while simultaneously increasing the hexane flow rate; and gradually tuning the RF power between 100 W and 1000 W for applying the coating.

[0054] In embodiments, method 400 can be performed for different precursor gases (e.g., acetylene) and process settings, as discussed below. For example, method 400 can be modified as follows. Operation P401 includes applying a coating of wear-resistant material to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. The application of the coating includes (e.g., a modification at operation P403) adjusting the radio frequency (RF) power of the RF electrode in the range of 50 W to 750 W for generating plasma; and exposing one or more of the plurality of protrusions in a chamber to a precursor gas, which is acetylene, at a gas flow rate between 10 sccm and 100 sccm (e.g., a modification at operation P405). In embodiments, the coating using acetylene produces a coating with relatively high hardness (compared to hexane), for example, a hardness greater than 25 GPa to 35 GPa, and can achieve corrosion resistance between 0.1 nm / hr and 2 nm / hr. The coating using acetylene may include 60% to 80% sp. 3 And 20% to 30% hydrogen.

[0055] In an embodiment, the application of the coating may further include adjusting one or more process parameters, said one or more process parameters including at least one of the following: the vacuum level of the chamber in which the substrate holder is placed, said vacuum level being at 1 × 10⁻⁶. -3 mbar to 5×10 -2Within the range of mbar; or the turntable speed of the stage on which the substrate holder is placed, the turntable speed being in the range of 5 rpm to 100 rpm. In an embodiment, the coating having the wear-resistant material causes the distal surface of one or more of the plurality of protrusions to also have at least one of the following properties: the coefficient of friction of the resulting coating, the coefficient of friction being in the range of 0.05 to 0.5; the surface of the resulting coating, the surface having high spots less than 10 nm and thickness uniformity across the plurality of protrusions of the substrate holder within 10% of the coating thickness in diameter of 300 mm or less; or a wafer loading grid, the wafer loading grid being in the range of 0.1 nm to 1.5 nm, the wafer loading grid being the relative positioning error of the substrate relative to a reference.

[0056] In an embodiment, method 400 can be modified such that a first coating using hexane as the precursor gas, as previously described, and a second coating using acetylene as the precursor gas, as previously described, are applied to the distal surface of one or more of the plurality of protrusions. For example, refer to Figure 3B The first coating may include a coating using hexane, and the second coating may include a coating using acetylene. A coating using hexane as a precursor gas may be applied to the distal surface of one or more of the plurality of protrusions, and a second coating using hexane as a precursor gas may be applied over the first coating. In one example, method 400 may include applying a first coating of wear-resistant material to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. Applying the first coating may include adjusting the radio frequency (RF) power of the RF electrode in the range of 100 W to 1000 W for generating plasma; and exposing one or more of the plurality of protrusions in a chamber to a precursor gas at a gas flow rate between 20 sccm and 300 sccm, the precursor gas being hexane. The first layer may include features similar to those of the previously described coatings using hexane. The method 400 may further include applying a second coating of the wear-resistant material to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition (e.g., coating onto the first coating). Applying the second coating may include adjusting the radio frequency (RF) power of the RF electrode in the range of 50 W to 750 W for generating plasma; and exposing one or more of the plurality of protrusions in a chamber to a precursor gas, wherein the precursor gas is acetylene, at a gas flow rate between 10 sccm and 100 sccm. The second coating may include features similar to those previously described for coatings using acetylene.

[0057] In embodiments, method 400 can be modified to provide a precursor gas selected from cyclohexane, n-hexane, or a mixture of carbon-rich and hydrogen-rich gases. For example, the mixture of carbon-rich and hydrogen-rich gases includes at least one of the following: acetylene and methane, acetylene and hexane, acetylene and cyclohexane, or acetylene and hydrogen. Depending on the precursor gas, the process parameters of PE-CVD can be adjusted to achieve a nozzle with a coating having a hardness greater than 21 GPa and corrosion resistance between 0.1 nm / hr and 2 nm / hr.

[0058] In the embodiments, the wear-resistant material coating includes (but is not limited to) diamond, WC, CrN, and TiN. These coatings can be deposited on various types of ceramic or glass substrates, including (but not limited to) Si, CVD-Si, SiC, SiSiC, CVD-SiC, zerodur, ULE, fused silica, BK-7, and Corning XG glass substrates, by depositing thin adhesion layers such as Cr and CrN, and other coatings known to have good adhesion to DLC coatings.

[0059] Figure 5 The illustration shows an example reactor 500 for performing a plasma-enhanced chemical vapor deposition process to apply a coating to a substrate holder. PE-CVD processes require tight control of a large number of parameters to achieve the desired coating properties. These control parameters include, but are not limited to, pressure p, gas flow, exhaust excitation frequency f, and power p. During deposition, the overall plasma parameters typically control the rate at which chemically active molecular fragments—radicals—and energetic substances such as electrons and ions are generated and accelerated towards the substrate surface exposed to the plasma at a given potential. Even for relatively simple gas mixtures, several plasma reactions occur, producing several new coating materials. However, most of the reaction rates are not readily available, making theoretical simulations of the process inefficient and inaccurate. Therefore, experimental methods are employed for process optimization to determine process options that produce the desired material properties.

[0060] exist Figure 5 In this embodiment, the PE-CVD reactor 500 includes a chamber CBR in which PE-CVD is performed on a substrate holder WT. The substrate holder WT is placed on a turntable TT. The speed of the turntable TT is controlled during the coating process of the substrate holder WT. The chamber CBR also contains plasma generated therein. In an embodiment, the plasma is generated by controlling the radio frequency (RF) power of the RF electrodes. For example, the RF power can be between 100W and 1000W, or between 50W and 750W.

[0061] The chamber CBR includes a gas distribution line GD, through which a precursor gas is supplied within the chamber CBR. In embodiments, the gas is hexane, acetylene, or other gases discussed herein. In one example, the hexane gas flow rate is controlled between 20 sccm and 300 sccm, while the RF power is controlled between 100 W and 1000 W. In another example, the acetylene gas flow rate is controlled between 10 sccm and 100 sccm, and the RF power can be between 50 W and 750 W.

[0062] In one embodiment, the reactor 500 may be connected to a vacuum system VS to control the vacuum level of the chamber CBR. In another embodiment, the reactor 500 is connected to a gas inlet through which gases such as argon (Ar) and oxygen (O) may be supplied to the chamber CBR. In yet another embodiment, gas may be supplied for cleaning the substrate holder WT before the coating is applied to it.

[0063] In one embodiment, the PE-CVD reactor 500 includes optical modulation spectroscopy (OMS) that can be used to study the CVD growth on the substrate holder WT. In another embodiment, the reactor 500 is water-cooled to control the temperature of the turntable TT.

[0064] In an embodiment, the chamber has a geometry described relative to different components inside the chamber. For example, the geometry may be characterized as a distance D1 or diameter D1 inside the chamber, a distance D2 between the top of the chamber and the turntable TT, and a distance D3 between the substrate or turntable and the gas distribution line (see [link to relevant documentation]). Figure 5 (D3 in the example), or other suitable geometric measurements. In the example, in Figure 5 In this example, distance D1 can be approximately 23 inches, distance D2 can be approximately 6 inches, and distance D3 can be approximately 5.25 inches. It is understood that the geometry of the chamber is presented as an example and other chamber geometries may be used.

[0065] The following sections discuss supporting examples 1, 2, and 3 for process parameters used in the PE-CVD process and the resulting coatings.

[0066] In Example 1, Si and SiSiC substrates (e.g., nodules) were coated with a DLC film of approximately 650 nm using hexane as the source gas. This coating run was performed using a hexane flow rate of 150 sccm and an RF power of 750 W. The resulting coatings were uniform and dense. The hardness of these coatings was measured using a hysitron nanoindenter equipped with a glass-diamond indenter at a maximum contact depth of <50 nm and was between 23 ± 1.5 GPa. Furthermore, the corrosion characteristics of these coatings were characterized using chronoamperometry measured in a three-electrode electrochemical cell with a +2.5 V potential difference between the working and counter electrodes, applied relative to a reference electrode in a dilute NaCl solution. The calculated corrosion rate was determined to be 1.1 nm / hr. These values ​​indicate that, compared to a standard DLC coating deposited using factory-set power and airflow parameters of approximately 1500W and 300sccm, hardness and corrosion resistance are increased by approximately 15% and 250%, respectively.

[0067] In Example 2, Si and SiSiC substrates (e.g., nodules) were coated with a DLC film of approximately 650 nm using acetylene as the source gas. This coating round was performed using an acetylene flow rate of 50 sccm and an RF power of 300 W. The resulting coatings were uniform and dense. The hardness of these coatings was measured using a hysitron nanoindenter equipped with a glass-diamond indenter at a maximum contact depth of <50 nm between 28 ± 1.5 GPa. Furthermore, the corrosion characteristics of these coatings were characterized using chronoamperometry measured in a three-electrode electrochemical cell with a +2.5 V potential difference between the working and counter electrodes, applied relative to a reference electrode in a dilute NaCl solution. The calculated corrosion rate was determined to be 1.6 nm / hr. These values ​​indicate that the hardness and corrosion resistance were increased by approximately 40% and 250%, respectively, compared to standard DLC films deposited using plant power and gas flow parameters of approximately 1500 W and 300 sccm, respectively.

[0068] In Example 3, Si and SiSiC substrates (e.g., nodules) were coated with a DLC film of approximately 650 nm using acetylene as the source gas. This coating round was performed using an acetylene flow rate of 30 sccm and an RF power of 150 W. The resulting coatings were uniform and dense. The hardness of these coatings was measured using a hysitron nanoindenter equipped with a glass-diamond indenter at a maximum contact depth of <50 nm between 31 ± 1.5 GPa. Furthermore, the corrosion characteristics of these coatings were characterized using chronoamperometry measured in a three-electrode electrochemical cell with a +2.5 V potential difference between the working and counter electrodes, applied relative to a reference electrode in a dilute NaCl solution. The calculated corrosion rate was determined to be 1.6 nm / hr. These values ​​indicate that the hardness and corrosion resistance were increased by approximately 40% and 250%, respectively, compared to standard DLC films deposited using plant power and gas flow parameters of approximately 1500 W and 300 sccm, respectively.

[0069] In an embodiment, a method is provided based on Figure 4 Substrate holders manufactured using methods such as (e.g., see...) Figure 3A and Figure 3B A substrate holder for use in a photolithography apparatus and configured to support a substrate includes a body (e.g., SiSiC) having a main surface and a plurality of protrusions projecting from the main surface. In an embodiment, each protrusion has a distal surface configured to engage with the substrate; the distal surface of the protrusion is substantially conformal to a support plane and configured to support the substrate; and the distal surface of one or more of the plurality of protrusions, coated with a wear-resistant material, has a hardness in the range of 20 GPa to 27 GPa or 25 GPa to 35 GPa and a corrosion rate in the range of 0.1 nm / hr to 2 nm / hr, the corrosion rate being measured by chronoamperometry in a three-electrode electrochemical cell having a +2.5 V potential difference between the working electrode and the counter electrode and said potential difference being applied relative to a reference electrode in a dilute NaCl solution. In an embodiment, the distal surface has a hardness in the range of 20 GPa to 27 GPa and a corrosion rate in the range of 0.1 nm / hr to 2 nm / hr.

[0070] As previously discussed, the distal surface has a hardness in the range of 25 GPa to 35 GPa and a corrosion rate in the range of 0.1 nm / hr to 1.5 nm / hr. As previously discussed, the hardness is measured, for example, by nanoindentation. Measurements are performed using a glass-type diamond indenter with a nano-DMA transducer, and the indentation depth is maintained below 10% of the coating thickness. In the embodiments, the coating thickness is between 200 nm and 3 micrometers. In the embodiments, the wear-resistant material is one of diamond-like carbon (DLC). In the embodiments, DLC includes: (i) DLC doped with B, N, Si, O, F, S; and / or (ii) DLC doped with metals such as Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au, or Ag.

[0071] In an embodiment, the distal surface also has at least one of the following properties: the coefficient of friction of the resulting coating, said coefficient of friction being in the range of 0.05 to 0.5; the surface of the resulting coating having nanobumps less than 10 nm and thickness uniformity across a plurality of protrusions spanning the substrate holder in the range of 10% above and below the coating thickness of 300 nm or less; or a wafer loading grid, said wafer loading grid being in the range of 0.1 nm to 1.5 nm, said wafer loading grid being the relative positioning error of the substrate relative to a reference.

[0072] While the concepts disclosed herein can be used for imaging on substrates such as silicon wafers, it should be understood that the disclosed concepts can be used with any type of lithography imaging system, such as those used for imaging on substrates other than silicon wafers.

[0073] The embodiments can be further described in the following aspects.

[0074] 1. A method for producing a substrate holder for use in a photolithography apparatus, the substrate holder comprising a plurality of protrusions projecting from the substrate holder, each protrusion having a distal surface configured to engage a substrate, the method comprising:

[0075] A coating of wear-resistant material is applied to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition.

[0076] The application of the coating includes:

[0077] Adjusting the radio frequency (RF) power of the RF electrodes within the range of 100W to 1000W to generate plasma; and

[0078] The one or more protrusions are exposed in a chamber to a precursor gas, which is hexane, at a gas flow rate between 20 sccm and 300 sccm.

[0079] 2. The method according to aspect 1, wherein applying the coating further comprises:

[0080] Adjust one or more process parameters, said one or more process parameters including at least one of the following:

[0081] The vacuum level of the chamber in which the substrate holder is placed is 1 × 10⁻⁶. -3 Up to 5×10 -2 Within the range of mbar; or

[0082] The stage on which the substrate holder is placed has a turntable speed in the range of 5 rpm to 100 rpm.

[0083] 3. The method according to any one of aspects 1 to 2, wherein the coating having a wear-resistant material causes the distal surfaces of one or more protrusions to further possess at least one of the following properties:

[0084] The resulting coating has a coefficient of friction in the range of 0.05 to 0.5.

[0085] The resulting coating surface has high speckles of less than 10 nm and thickness uniformity spanning the plurality of protrusions of the substrate holder within a diameter of 300 nm or less, within 10% above and below the coating thickness; or

[0086] A wafer loading grid, the wafer loading grid being in the range of 0.1 nm to 1.5 nm, the wafer loading grid being the relative positioning error of the substrate relative to a reference.

[0087] 4. The method according to any one of aspects 1 to 3, wherein the wear-resistant material is diamond-like carbon (DLC).

[0088] 5. The method according to aspect 4, wherein the DLC comprises: (i) DLC doped with B, N, Si, O, F, S; and / or (ii) DLC doped with metals, wherein the metals are Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au or Ag.

[0089] 6. The method according to any one of aspects 1 to 5, wherein the coating of the wear-resistant material causes the distal surface of the one or more protrusions to have hardness properties in the range of 20 GPa to 27 GPa and corrosion rate properties in the range of 0.1 nm / hr to 2 nm / hr, said corrosion rate being measured by potentiostat chronoamperometry in a dilute NaCl solution at approximately +2.5 V.

[0090] 7. The method according to any one of aspects 1 to 6, wherein the hardness is measured by nanoindentation, wherein the measurement is performed using a nano-DMA transducer with a glass diamond indenter and the indentation depth is maintained below 10% of the coating thickness.

[0091] 8. The method according to any one of aspects 1 to 7, wherein the thickness of the coating is between 200 nm and 3 micrometers.

[0092] 9. The method according to any one of aspects 1 to 8, further comprising:

[0093] The plurality of protuberances were cleaned with argon (Ar) gas before the coating was applied.

[0094] 10. The method according to aspect 9, wherein the cleaning further comprises:

[0095] Plasma was generated using Ar gas at an RF power of approximately 1000W;

[0096] Adjust the Ar flow rate to 75 sccm for 100 seconds.

[0097] 11. The method according to aspect 10, further comprising:

[0098] Gradually decrease the Ar flow rate while simultaneously increasing the hexane flow rate; and

[0099] The RF power is gradually tuned between 100W and 1000W for applying the coating.

[0100] 12. The method according to any one of aspects 1 to 11, wherein the chamber has a geometric shape, characterized in that:

[0101] The diameter of the interior of the chamber;

[0102] The distance between the top of the chamber and the turntable; and / or

[0103] The distance between the substrate or turntable and the gas distribution line.

[0104] 13. A method of producing a substrate holder for use in a photolithography apparatus, the substrate holder comprising a plurality of protrusions projecting from the substrate holder, each protrusion having a distal surface configured to engage a substrate, the method comprising:

[0105] A coating of wear-resistant material is applied to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition.

[0106] The application of the coating includes:

[0107] The radio frequency (RF) power of the RF electrodes is adjusted within the range of 50W to 750W to generate plasma; and

[0108] The one or more protrusions are exposed in a chamber to a precursor gas, which is acetylene, at a gas flow rate between 10 sccm and 100 sccm.

[0109] 14. The method according to aspect 13, wherein applying the coating further comprises:

[0110] Adjust one or more process parameters, said one or more process parameters including at least one of the following:

[0111] The vacuum level of the chamber in which the substrate holder is placed is 1 × 10⁻⁶. -3 Up to 5×10 -2 Within the range of mbar; or

[0112] The stage on which the substrate holder is placed has a turntable speed in the range of 5 rpm to 100 rpm.

[0113] 15. The method according to any one of aspects 13 to 14, wherein the coating having a wear-resistant material causes the distal surfaces of one or more protrusions to further possess at least one of the following properties:

[0114] The resulting coating has a coefficient of friction in the range of 0.05 to 0.5.

[0115] The resulting coating surface has nanobumps smaller than 10 nm and thickness uniformity within 10% of the coating thickness in a diameter range of 300 nm or less, spanning the plurality of protrusions of the substrate holder; or

[0116] A wafer loading grid, the wafer loading grid being in the range of 0.1 nm to 1.5 nm, the wafer loading grid being the relative positioning error of the substrate relative to a reference.

[0117] 16. The method according to any one of aspects 13 to 15, wherein the wear-resistant material is diamond-like carbon (DLC).

[0118] 17. The method according to aspect 16, wherein the DLC comprises: (i) DLC doped with B, N, Si, O, F, S; and / or (ii) DLC doped with metals, wherein the metals are Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au or Ag.

[0119] 18. The method according to any one of aspects 13 to 17, wherein the coating of the wear-resistant material causes the distal surface of the one or more protrusions to have hardness properties in the range of 25 GPa to 35 GPa and corrosion rate properties in the range of 0.1 nm / hr to 2 nm / hr, said corrosion rate being measured by chronoamperometry in a three-electrode electrochemical cell having a potential difference of approximately +2.5 V between the working electrode and the counter electrode and said potential difference being applied relative to a reference electrode in a dilute NaCl solution.

[0120] 19. The method according to any one of aspects 13 to 18, wherein the hardness is measured by nanoindentation, wherein the measurement is performed using a nano-DMA transducer with a glass diamond indenter and the indentation depth is maintained below 10% of the coating thickness.

[0121] 20. The method according to any one of aspects 13 to 19, wherein the thickness of the coating is between 200 nm and 3 micrometers.

[0122] 21. The method according to any one of aspects 13 to 20, further comprising:

[0123] The plurality of protuberances were cleaned with argon (Ar) gas before the coating was applied.

[0124] 22. The method according to aspect 21, wherein the cleaning further comprises:

[0125] Plasma was generated using Ar gas at an RF power of approximately 1000W;

[0126] Adjust the Ar flow rate to 75 sccm for 100 seconds.

[0127] 23. The method according to aspect 22 further includes:

[0128] Gradually decrease the Ar flow rate while simultaneously increasing the hexane flow rate; and

[0129] The RF power is gradually tuned between 100W and 1000W for applying the coating.

[0130] 24. The method according to any one of aspects 13 to 23, wherein the chamber has a geometric shape, characterized in that:

[0131] The diameter of the interior of the chamber;

[0132] The distance between the top of the chamber and the turntable; and / or

[0133] The distance between the substrate or turntable and the gas distribution line.

[0134] 25. A substrate holder for use in a photolithography apparatus and configured to support a substrate, the substrate holder comprising:

[0135] The main body has a main body surface;

[0136] Multiple protrusions protruding from the surface of the body, wherein:

[0137] Each protrusion has a distal surface configured to engage with the substrate;

[0138] The distal surface of the protrusion is substantially conformal to the support plane and configured to support the substrate; and

[0139] One or more of the protrusions have a wear-resistant material-coated distal surface with a hardness in the range of 20 GPa to 27 GPa or 25 GPa to 35 GPa and a corrosion rate in the range of 0.1 nm / hr to 2 nm / hr, said corrosion rate being measured by chronoamperometry in a three-electrode electrochemical cell having a potential difference of approximately +2.5 V between the working electrode and the counter electrode and said potential difference being applied relative to a reference electrode in a dilute NaCl solution.

[0140] 26. The substrate holder according to any one of aspects 25, wherein the distal surface has a hardness in the range of 20 GPa to 27 GPa and an etching rate in the range of 0.1 nm / hr to 2 nm / hr.

[0141] 27. The substrate holder according to any one of aspects 26, wherein the distal surface has a hardness in the range of 25 GPa to 35 GPa and an etching rate in the range of 0.1 nm to 1.5 nm / hr.

[0142] 28. The substrate holder according to any one of aspects 25 to 27, wherein the distal surface further has at least one of the following properties:

[0143] The resulting coating has a coefficient of friction in the range of 0.05 to 0.5.

[0144] The resulting coating surface has nanobumps smaller than 10 nm and thickness uniformity within 10% of the coating thickness in a diameter range of 300 nm or less, spanning the plurality of protrusions of the substrate holder; or

[0145] A wafer loading grid, the wafer loading grid being in the range of 0.1 nm to 1.5 nm, the wafer loading grid being the relative positioning error of the substrate relative to a reference.

[0146] 29. The substrate holder according to any one of aspects 25 to 28, wherein the hardness is measured by nanoindentation, wherein the measurement is performed using a nano-DMA transducer with a glass diamond indenter and the indentation depth is maintained below 10% of the coating thickness.

[0147] 30. The method according to any one of aspects 25 to 29, wherein the thickness of the coating is between 200 nm and 3 micrometers.

[0148] 31. The substrate holder according to any one of aspects 25 to 30, wherein the wear-resistant material is a type of diamond-like carbon (DLC).

[0149] 32. The substrate holder according to aspect 31, wherein the DLC comprises: (i) a DLC doped with B, N, Si, O, F, or S; and / or (ii) a DLC doped with a metal, wherein the metal is doped with Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au, or Ag.

[0150] 33. A method for producing a substrate holder for use in a photolithography apparatus, the substrate holder comprising a plurality of protrusions projecting from the substrate holder, each protrusion having a distal surface configured to engage a substrate, the method comprising:

[0151] A first coating of wear-resistant material is applied to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition.

[0152] The application of the first coating includes:

[0153] The radio frequency (RF) power of the RF electrodes can be adjusted within the range of 100W to 1000W to generate plasma; and

[0154] In the chamber, one or more of the plurality of protuberances are exposed to a precursor gas at a gas flow rate between 20 sccm and 300 sccm, said precursor gas being hexane;

[0155] A second coating of wear-resistant material is applied to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition.

[0156] The application of the second coating includes:

[0157] The radio frequency (RF) power of the RF electrodes can be adjusted within the range of 50W to 750W to generate plasma; and

[0158] In a chamber, one or more of the plurality of protuberances are exposed to a precursor gas, which is acetylene, at a gas flow rate between 10 sccm and 100 sccm.

[0159] The above description is intended to be illustrative and not restrictive. Therefore, those skilled in the art will understand that modifications can be made as described without departing from the scope of the claims set forth below.

Claims

1. A method for producing a substrate holder for use in a photolithography apparatus, the substrate holder comprising a plurality of protrusions projecting from the substrate holder, each protrusion having a distal surface configured to engage a substrate, the method comprising: A coating of wear-resistant material is applied to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. The application of the coating includes: The radio frequency (RF) power of the RF electrodes is adjusted within the range of 100 W to 1000 W to generate plasma; and The one or more protuberances are exposed in a chamber to a precursor gas, which is hexane, at a gas flow rate between 20 sccm and 300 sccm. The wear-resistant material is diamond-like carbon (DLC).

2. The method according to claim 1, wherein, The application of the coating also includes: Adjust one or more process parameters, said one or more process parameters including at least one of the following: a vacuum level of the chamber in which the substrate holder is placed, the vacuum level being in the range of 1 x 10 -3 to 5 x 10 -2 mbar; or The stage on which the substrate holder is placed has a turntable speed in the range of 5 rpm to 100 rpm.

3. The method according to any one of claims 1 to 2, wherein, The coating with a wear-resistant material causes the distal surface of one or more protrusions to also possess at least one of the following properties: The coefficient of friction of the resulting coating is in the range of 0.05 to 0.5; The resulting coating surface has high speckles of less than 10 nm, and thickness uniformity spanning the plurality of protrusions of the substrate holder within a diameter of 300 nm or less, within 10% above and below the coating thickness; or The wafer loading grid, in the range of 0.1 nm to 1.5 nm, is the relative positioning error of the substrate relative to a reference.

4. The method according to any one of claims 1 to 3, wherein, The DLC includes: (i) DLCs doped with B, N, Si, O, F, or S; and / or (ii) DLCs doped with metals such as Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au, or Ag.

5. The method according to any one of claims 1 to 4, wherein, The coating of the wear-resistant material imparts to the distal surfaces of the one or more protrusions a hardness in the range of 20 GPa to 27 GPa and a corrosion rate in the range of 0.1 nm / hr to 2 nm / hr, the corrosion rate being measured in dilute NaCl solution by potentiostat chronoamperometry at approximately +2.5 V; and / or The hardness is measured by nanoindentation, wherein the measurement is performed using a glass diamond indenter with a nano-DMA transducer and the indentation depth is kept below 10% of the coating thickness.

6. The method according to any one of claims 1 to 5, further comprising: The plurality of protrusions were cleaned with argon (Ar) gas prior to the application of the coating, wherein the cleaning involved generating plasma using the Ar gas at an RF power of approximately 1000 W and adjusting the Ar gas flow rate at 75 sccm for 100 seconds. Gradually decrease the Ar flow rate while simultaneously increasing the hexane flow rate; and The RF power is gradually tuned between 100 W and 1000 W to apply the coating.

7. The method according to any one of claims 1 to 6, wherein, The chamber has a geometry characterized by the following: The diameter of the interior of the chamber; The distance between the top of the chamber and the turntable; and / or The distance between the substrate or turntable and the gas distribution line.

8. A method for producing a substrate holder for use in a photolithography apparatus, the substrate holder comprising a plurality of protrusions projecting from the substrate holder, each protrusion having a distal surface configured to engage a substrate, the method comprising: A coating of wear-resistant material is applied to the distal surface of one or more of the plurality of protrusions via plasma-enhanced chemical vapor deposition. The application of the coating includes: The radio frequency (RF) power of the RF electrodes is adjusted within the range of 50 W to 750 W to generate plasma; and The one or more protuberances are exposed in a chamber to a precursor gas, which is acetylene, at a gas flow rate between 10 sccm and 100 sccm. The wear-resistant material is diamond-like carbon (DLC).

9. The method according to claim 8, wherein, The application of the coating also includes: Adjust one or more process parameters, said one or more process parameters including at least one of the following: a vacuum level of the chamber in which the substrate holder is placed, the vacuum level being in the range of 1 x 10 -3 to 5 x 10 -2 mbar; or The stage on which the substrate holder is placed has a turntable speed in the range of 5 rpm to 100 rpm.

10. The method according to any one of claims 8 to 9, wherein, The coating with a wear-resistant material causes the distal surface of one or more protrusions to also possess at least one of the following properties: The resulting coating has a coefficient of friction in the range of 0.05 to 0.

5. The resulting coating surface has nanobumps smaller than 10 nm and thickness uniformity within 10% of the coating thickness in a diameter range of 300 nm or smaller, spanning the plurality of protrusions of the substrate holder; or A wafer loading grid, the wafer loading grid being in the range of 0.1 nm to 1.5 nm, the wafer loading grid being the relative positioning error of the substrate relative to a reference.

11. The method according to any one of claims 8 to 10, wherein, The DLC includes: (i) DLCs doped with B, N, Si, O, F, or S; and / or (ii) DLCs doped with metals such as Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au, or Ag.

12. The method according to any one of claims 8 to 11, wherein, The coating of the wear-resistant material imparts a hardness property of the distal surface of the one or more protrusions in the range of 25 GPa to 35 GP and a corrosion rate property in the range of 0.1 nm / hr to 2 nm / hr, the corrosion rate being measured by chronoamperometry in a three-electrode electrochemical cell with a potential difference of approximately +2.5 V between the working electrode and the counter electrode, said potential difference being applied relative to a reference electrode in a dilute NaCl solution; and / or The hardness is measured by nanoindentation, wherein the measurement is performed using a glass diamond indenter with a nano-DMA transducer and the indentation depth is kept below 10% of the coating thickness.

13. The method according to any one of claims 8 to 12, further comprising: The plurality of protrusions were cleaned with argon (Ar) gas prior to the application of the coating, wherein the cleaning also included generating plasma with the Ar gas at an RF power of approximately 1000 W and adjusting the Ar gas flow rate at 75 sccm for 100 seconds; Gradually decrease the Ar flow rate while simultaneously increasing the hexane flow rate; and The RF power is gradually tuned between 100 W and 1000 W to apply the coating.

14. The method according to any one of claims 8 to 13, wherein, The chamber has a geometry characterized by the following: The diameter of the interior of the chamber; The distance between the top of the chamber and the turntable; and / or The distance between the substrate or turntable and the gas distribution line.

15. A substrate holder for use in a photolithography apparatus and configured to support a substrate, the substrate holder comprising: The main body has a main body surface; Multiple protrusions protruding from the surface of the body, wherein: Each protrusion has a distal surface configured to engage with the substrate; The distal surface of the protrusion is substantially conformal to the support plane and configured to support the substrate; and One or more of the protrusions, with their distal surfaces coated with a wear-resistant material, have a hardness in the range of 20 GPa to 27 GPa or 25 GPa to 35 GPa and a corrosion rate in the range of 0.1 nm / hr to 2 nm / hr, said corrosion rate being measured by chronoamperometry in a three-electrode electrochemical cell having a potential difference of approximately +2.5 V between the working electrode and the counter electrode, said potential difference being applied relative to a reference electrode in a dilute NaCl solution. The wear-resistant material is diamond-like carbon (DLC).

Images