KR20230007508A - Substrate holder for use in lithographic apparatus, and method of manufacturing the substrate holder - Google Patents

Abstract

Described herein is a method of manufacturing a substrate holder for use in a lithographic apparatus, the substrate holder including a plurality of burls protruding from the substrate holder, each burl having a distal end surface configured to engage a substrate. The method includes applying a coating of a wear resistant material to a distal end surface of one or more burls of a plurality of burls via plasma enhanced chemical vapor deposition. Applying the coating may include adjusting the RF power of the RF electrode in the range of 100 to 1000 W to generate plasma; and in the chamber, exposing the one or more plurality of burls to a precursor gas at a gas flow rate of 20 to 300 sccm, wherein the precursor gas is hexane.

Description

Substrate holder for use in lithographic apparatus, and method of manufacturing the substrate holder

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims priority from US Provisional Patent Application Serial No. 63/036,028, filed on June 8, 2020, the contents of which are incorporated herein in their entirety by reference.

The present invention relates to a substrate holder for use in a lithographic apparatus, and a method of manufacturing a substrate holder.

A lithographic apparatus is a machine configured to apply a desired pattern onto a substrate. A lithographic apparatus may be used, for example, in the manufacture of integrated circuits (ICs).

A lithographic apparatus is, for example, a radiation-sensitive method of providing a pattern (also often referred to as a "design layout" or "design") of a patterning device (eg, mask) onto a substrate (eg, wafer). It can be projected onto a layer of material (resist).

As semiconductor manufacturing processes continue to evolve, the dimensions of circuit elements continue to decrease, in a trend commonly referred to as "Moore's Law", while the amount of functional elements such as transistors per device has been steadily decreasing for decades. It is increasing. To follow Moore's Law, the semiconductor industry is seeking technologies that make it possible to create increasingly smaller features. A lithographic apparatus may use electromagnetic radiation to project a pattern onto a substrate. The wavelength of this radiation determines the minimum size of features patterned on the substrate. Typical wavelengths currently in use are 365 nm (i-line), 248 nm (KrF), 193 nm (ArF) and 13.5 nm (EUV).

In a lithographic apparatus, a substrate to be exposed (which may be referred to as a production substrate) is held on a substrate holder (sometimes referred to as a wafer table). The substrate holder may be movable relative to the projection system. Substrate holders generally include a solid body made of a rigid material and having dimensions similar in plan to the production substrate to be supported. The substrate-facing surface of the solid body has a plurality of projections (referred to as burls). The distal surface of the burls conforms to a flat plane and supports the substrate. Burls offer several advantages: contaminant particles on the substrate holder or on the substrate are likely to fall between the burls and thus do not cause deformation of the substrate; It is easier to machine burls to conform to a flat end than to flatten the surface of a solid body; And the properties of the burls can be adjusted to control, for example, the clamping of the substrate.

However, due to repeated loading and unloading of substrates, for example, the burls of the substrate holder wear out during use. Non-uniform wear of the burls leads to non-flatness of the substrate during exposure, which can lead to reduced process windows and in extreme cases to imaging and/or overlay errors. Due to the very precise manufacturing specifications, substrate holders are expensive to manufacture and therefore it is desirable to increase the working life of the substrate holder.

In an embodiment, a method of manufacturing a substrate holder for use in a lithographic apparatus is provided. The substrate holder includes a plurality of burls projecting from the substrate holder, each burl having a distal end surface configured to engage a substrate. The method includes applying a coating of a wear resistant material to a distal end surface of one or more burls of a plurality of burls via plasma enhanced chemical vapor deposition. Application of the coating may be performed by adjusting the radio frequency (RF) power of the RF electrode in the range of 100 to 1000 W to generate a plasma; and in the chamber, exposing the one or more plurality of burls to a precursor gas, wherein the precursor gas is hexane, at a gas flow rate of 20 to 300 sccm.

Also in an embodiment, a method of manufacturing a substrate holder for use in a lithographic apparatus is provided. The substrate holder includes a plurality of burls projecting from the substrate holder, each burl having a distal end surface configured to engage a substrate. The method includes applying a coating of a wear resistant material to a distal end surface of one or more burls of a plurality of burls via plasma enhanced chemical vapor deposition. Application of the coating comprises adjusting the radio frequency (RF) power of the RF electrode in the range of 50 to 750 W to generate a plasma; and in the chamber, exposing one or more of the plurality of burls to a precursor gas, wherein the precursor gas is acetylene, at a gas flow rate of 10 to 100 sccm.

Also in an embodiment, a substrate holder for use in a lithographic apparatus and configured to support a substrate is provided. The substrate holder includes a body having a body surface; and a plurality of burls protruding from the body surface. Each burl has a distal end surface configured to engage a substrate. a distal end surface of the burls conforms to a support plane and is configured to support a substrate; Also, the distal end surface of at least one of the plurality of burls is coated with a wear resistant material having a hardness in the range of 20 to 27 GPa or 25 to 35 GPa and a corrosion rate in the range of 0.1 to 2 nm/hr. The corrosion rate is measured by chronoamperometry in a three-electrode electrochemical cell with a potential difference of about +2.5 V between the working and counter electrodes and is applied against a reference electrode in dilute NaCl solution.

Embodiments will be described by way of example only with reference to the accompanying schematic drawings, in which:
1 is a block diagram of various subsystems of a lithography system according to an embodiment.
2A shows a substrate or wafer being loaded onto a substrate holder (also referred to as a wafer table (WT)) via an electrostatic clamp (ESC), with the substrate in an unloaded position on an e-pin, according to an embodiment. supported
2B shows a substrate in a loading position on a substrate holder, according to an embodiment.
2C to 2F show a sequence of loading a substrate onto a substrate holder according to an embodiment.
3A shows a substrate loaded onto a substrate holder, the surface of which includes burls with slight roughness upon which the substrate rests, according to an embodiment.
3B is an exemplary burl of the substrate holder of FIG. 3A according to an embodiment.
4 is a flow diagram of a method for manufacturing a substrate holder, according to an embodiment.
5 depicts an exemplary plasma enhanced chemical vapor deposition apparatus, according to an embodiment.
Embodiments will now be described in detail with reference to the drawings, which are provided as illustrative examples to enable those skilled in the art to practice the embodiments. In particular, the figures and examples below are not meant to limit the scope to a single embodiment, and other embodiments are possible through the interchange of some or all of the described or illustrated elements. Whenever convenient, the same reference numbers will be used throughout the drawings to refer to the same or like parts. If certain elements of this embodiment can be partially or completely implemented using known elements, only those parts necessary for understanding the embodiment of these known elements will be described, and the description of the embodiments will not be obscured. For the sake of clarity, detailed descriptions of other parts of these well-known components will be omitted. In this specification, examples showing single components should not be considered limiting; Rather, unless expressly stated otherwise herein, the scope is intended to include other embodiments that include a plurality of the same elements and vice versa. Furthermore, Applicants do not intend that any term in the specification or claims be to be construed to have a non-generic or special meaning unless expressly indicated. In addition, the scope includes, by way of example, present and future known equivalents to the elements mentioned herein.

Although features of the present invention are described within this specification with reference to exemplary embodiments for specific applications, it should be understood that the present invention is not limited thereto. Those skilled in the art who have access to the teachings provided herein will recognize additional modifications, applications and embodiments within the scope of this invention and additional fields in which this invention will find considerable utility.

In the present invention, the term “mask” or “patterning device” as used herein refers to a generic patterning device that can be used to impart an incident radiation beam with a patterned cross-section corresponding to a pattern to be created in a target portion of a substrate. can be interpreted broadly as referring to a device; The term "light valve" may also be used in this context. Examples of such patterning devices other than classic masks (transmissive or reflective; binary, phase-shifting, hybrid, etc.) include:

- Programmable Mirror Array. An example of such a device is a matrix-addressable surface having a viscoelastic control layer and a reflective surface. The basic principle behind such devices is that (eg) addressed areas of the reflective surface reflect incident radiation as diffracted radiation, while unaddressed areas reflect incident radiation as undiffracted radiation. Using an appropriate filter, the undiffracted radiation can be filtered out of the reflected beam leaving only the diffracted radiation; In this way the beam is patterned according to the addressing pattern of the matrix-addressable surface. The required matrix addressing can be performed using suitable electronic means. More information on such mirror arrays may be obtained, for example, from US Pat. Nos. 5,296,891 and 5,523,193, incorporated herein by reference.

- Programmable LCD array. An example of such a construction is provided in U.S. Patent No. 5,229,872, the contents of which are incorporated herein by reference.

As a brief introduction, Figure 1 depicts an exemplary lithographic projection apparatus 10A. A key component is a radiation source 12A, which may be a deep ultraviolet excimer laser source, or another type of source including an extreme ultraviolet (EUV) source (as discussed above, the lithographic projection apparatus itself does not need to have a radiation source). none); illumination optics, which may include optics 14A, 16Aa and 16Ab to define partial coherence (denoted as sigma) and to shape the radiation from source 12A; patterning device 18A; and a transmission optical system 16Ac that projects the image of the patterning device pattern onto the substrate plane 22A. An adjustable filter or aperture 20A in the pupil plane of the projection optics can limit the range of beam angles impinging on the substrate plane 22A, where the largest possible angle is the numerical aperture of the projection optics (NA=sin (Θ _max )).

In a lithographic projection apparatus, a source provides illumination (ie, light); Projection optics direct and shape the illumination through the patterning device and onto the substrate. The term "projection optics" is broadly defined herein to include any optical component capable of altering the wavefront of a radiation beam. For example, the projection optical system may include at least some of the components 14A, 16Aa, 16Ab, and 16Ac. An aerial image (AI) is the radiation intensity distribution at the substrate level. A resist layer on the substrate is exposed, and an aerial image is transferred to the resist layer as a latent "resist image" (RI) therein. The resist image RI may be defined as the spatial distribution of the solubility of a resist in a resist layer. A resist model can be used to compute a resist image from an aerial image, examples of which can be found in commonly assigned US patent application Ser. No. 12/315,849, the contents of which are hereby incorporated by reference in their entirety. . The resist model relates only to the properties of the resist layer (eg, effects of chemical processes occurring during exposure, PEB and development). Optical properties of a lithographic projection apparatus (eg, properties of the source, patterning device, and projection optics) govern the aerial image. Because the patterning device used in a lithographic projection apparatus can vary, it is desirable to separate the optical characteristics of the patterning device from the optical characteristics of the rest of the lithographic projection apparatus, including at least the source and projection optics.

As used herein, the terms “radiation” and “beam” refer to ultraviolet radiation (e.g., having a wavelength of 365, 248, 193, 157 or 126 nm) and EUV (e.g., having wavelengths in the range of 5 to 20 nm). It is used to include all types of electromagnetic radiation, including extreme ultraviolet radiation).

Also, the lithographic projection apparatus may be of a type having one or more substrate holders, eg two substrate holders (and/or one or more patterning device tables, eg two patterning device tables). In such "multiple stage" devices, the additional tables may be used simultaneously, or preparatory steps may be performed on one or more tables while one or more other tables are being used for exposure. A twin stage lithographic projection apparatus is described, for example, in US Pat. No. 5,969,441, incorporated herein by reference.

In a lithographic apparatus (eg, FIG. 1 ), a substrate to be exposed (which may be referred to as a production substrate) is held on a substrate holder (sometimes referred to as a wafer table or substrate holder). The substrate holder WT is designed for precise positioning of the substrate during exposure. The substrate holder (eg, the WT of FIGS. 2A and 3A ) may be movable relative to the projection device. Substrate holders generally include a solid body made of a rigid material and having in-plane XY dimensions similar to the production substrate to be supported. The substrate-facing surface of the solid body has a plurality of projections (referred to as burls). The distal surface of the burls (see Fig. 3b) conforms to a flat plane and supports the substrate. Burls offer several advantages: contaminant particles on the substrate holder or on the substrate are likely to fall between the burls and thus do not cause deformation of the substrate; It is easier to machine burls to conform to a flat end than to flatten the surface of a solid body; And the properties of the burls can be adjusted to control, for example, the clamping of the substrate. In an embodiment, the burls reduce the contact area which reduces friction and sticking between the substrate holder WT and the substrate W.

However, due to repeated loading and unloading of substrates, for example, the burls of the substrate holder wear out during use. Non-uniform wear of the burls leads to non-flatness of the substrate during exposure (e.g., surface profile out of specification in the z-direction), which can lead to a reduction in the process window and in extreme cases to imaging and/or overlay errors. can lead Due to the very precise manufacturing specifications, substrate holders are expensive to manufacture and therefore it is desirable to increase the working life of the substrate holder.

Some substrate holders may have a diamond-like carbon coating (DLC) on a body that is generally SiC or SiSiC. However, wear, oxidation and unstable friction of DLC-coated burls are believed to cause significant problems for substrate holder degradation.

Accordingly, it is desirable to coat the substrate holder or at least the burls of the substrate holder with a coating such as diamond or other superhard material. However, available fabrication CVD techniques, for example for diamond growth, require higher deposition temperatures (400 to 1,200 °C), which can result in higher thermal stresses and consequently warping of the substrate holder. This will eventually require additional time consuming manufacturing steps to bring the substrate holder to flatness specifications.

2A and 2B show the loading and unloading of the substrate W onto the substrate holder WT by the wafer handler WH. The substrate holder WT typically has a plurality of burls for supporting the substrate W. For example, more than 10,000 burls are provided on top of the substrate holder WT, and these burls contact the substrate W. When the substrate W is first loaded onto the substrate holder WT in preparation for exposure, the substrate W is provided with three or more ejection pins (e-pins) (for example, two pins labeled PI1 and PI2). ), and the ejection pin holds the substrate (W). When the substrate is placed on the e-pin, the wafer handler (WH) retraces. To hold and support the substrate W on the substrate holder WT during steps and scans, the substrate W is clamped on a burl (see, eg, FIGS. 2A and 3A ). The clamping mechanism may include, for example, vacuum force in DUV or electrostatic force in EUV.

While the substrate W is held by the e-pins, the weight of the substrate itself and the stress of the treated layer and backside coating will cause the substrate W to distort, eg convexly concave. To load the substrate W onto the substrate holder WT, the e-pin is retracted so that the substrate W is supported by the burls of the substrate holder WT. As the substrate W is lowered onto the burls of the substrate holder WT, the substrate W will contact some places, eg closer to the edges, before other places, eg closer to the center. Any friction between the burls (see FIGS. 2C-2F ) and the lower surface of the substrate W may prevent the substrate W from completely relaxing to a flat, unstressed state. This can lead to focus and overlay errors during exposure of the substrate W.

Growing a thicker layer on a wafer results in a curved wafer, for example the wafer is bent up to 400 μm. This deviation leads to overlay defects on the wafer due to misalignment and distorted patterns. When a bent wafer is loaded and clamped on the substrate holder WT, in-plane stresses are introduced. 2c-2f illustrate an exemplary loading sequence of the substrate W and the friction between the burls and the substrate W. Sequence of wafer loading from e-pin to substrate holder (WT) or electrostatic clamp (ESC). For example, the wafer W on the e-pin moves down to the substrate holder WT (see Fig. 2c), the bent wafer W' touches the substrate holder WT at the edge (see Fig. 2d), The wafer W is clamped to the substrate holder WT (see Fig. 2e), and the stress is locked to the wafer (Fig. 2e). In this case, the combination of wafer shape, coefficient of friction and normal force causes WLG problems, eg positioning errors relative to the reference grid.

The substrate holder WT is typically made of a ceramic material such as silicon carbide (SiC) or SiSiC, which is a material having SiC grains in a silicon matrix. These ceramic materials can be readily processed into desired shapes using conventional manufacturing methods. When the substrate W is loaded and unloaded from the substrate holder WT, the ceramic material may wear out quickly. The relatively high coefficient of friction of the ceramic material may also prevent the substrate W from relaxing to a flat unstressed state when loaded onto the substrate holder WT.

3A and 3B, in an embodiment, one or more burls 310 of the substrate holder WT are coated with a coating 311 of a wear-resistant material (eg, diamond-like carbon (DLC)). Body 312 is included. The coating portion 311 is resistant to abrasion and reduces friction between the substrate holder and the substrate W. In an example, the DLC may be deposited directly onto the burls of the substrate holder WT. In an example, the DLC may be deposited directly onto the entire substrate holder (WT). Deposition of DLC is possible at temperatures below 300°C. Temperatures in excess of 300° C. risk damage to the substrate holder.

In an embodiment, the coating 311 may include a first coating and a second coating of a wear resistant material (eg, DLC). The first coating unit and the second coating unit may include features similar to those of the coating unit 311 . The first coating may be deposited directly onto the substrate holder such that the substrate holder is coated by the first coating. A 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.

Using existing coating techniques, the inventors have found that the performance of such DLC-coated substrate holders can be measured in substrate performance specifications (e.g., flatness, focus and overlay) (wear and corrosion of the substrate holder are focus and overlay problems in the substrate). It was recognized that it did not satisfy the root cause of The DLC (the area arranged to be in contact with the substrate) deposited on the substrate holder (WT) wears out about 10 times faster than desired, requiring regrinding and readjustment of the substrate holder much sooner than the desired operating period. In an embodiment, the performance of the substrate holder (WT) is measured in parameters such as wafer load grid (WLG) and flatness.

Degradation of the substrate holder (WT) leads to a limited lifetime, and therefore premature substrate holder (WT) replacement or resurfacing may be required. The substrate holder may wear out in the flatness and smoothness of the top of the burls, for example in a flower pattern. The cause of this degradation may be chemical wear, mechanical wear or a combination thereof. Current substrate holder (WT) designs with DLC coatings show significant WLG drift and flatness degradation. For example, the WLG drift rate is 20 nm per million substrate passes, with a flatness degradation of 10 nm per million substrate passes due to wear. In an embodiment, wear refers to a combination of all wears.

In an embodiment, the coating 311 is configured to improve substrate holder performance by reducing mechanical and chemical wear achieved through high coating hardness and corrosion inertness. As described herein, the improved DLC coating process or improved DLC coating reduces WLG drift, eg, from a current value of 20 nm per million substrate passes to less than 15 nm per million substrate passes. let it The DLC coatings described herein can also improve flatness degradation resulting from, for example, mechanical wear. For example, flatness degradation can also be reduced from 10 nm per million substrate passes to less than 7 nm per million substrate passes.

According to the embodiment, flatness deterioration occurs due to non-uniform wear of the DLC coating portion by chucking and de-chucking of multiple substrates. The mechanics of the process impose a higher lateral displacement at the periphery of the substrate holder WT and therefore higher edge wear. This non-uniform wear of the coating causes deterioration and flatness of the substrate holder, reducing process yield and also causing the need for premature substrate holder replacement and machine downtime. As such, the coating process must be tailored to produce a coating composition with high hardness and wear resistance properties to minimize edge wear and maximize substrate holder (WT) life.

According to an embodiment, a low coefficient of friction is desirable to minimize WLG. Most commercially available coatings (eg DLC coatings) can meet specifications at their initial use stage in WT burls. However, increasing the number of substrate passes removes the top surface roughness of the burls, thus allowing the substrate to adhere to the substrate table WT via, for example, Van der Waals forces and capillary forces. This chemical adhesion of the substrate to the top surface of the burls causes an increase in the coefficient of friction and WLG. The increase in WLG directly translates into overlay issues that reduce process yield and force premature substrate holder (WT) changes in the field.

The present invention describes improved coating compositions and methods of coating substrate holders. For example, coating can be performed using a parallel plate plasma enhanced chemical vapor deposition (PE-CVD) reactor. A conventional setup for PE-CVD is an RF power of the RF electrode of about 1500 W and a hexane gas flow of 300 sccm or more. However, using this process, the conventional a-c:H DLC coating has a hardness of about 21 GPa or less and a corrosion rate of 2.7 nm/hr or more. According to this embodiment, an improved coating hardness of 23 GPa or more and a corrosion rate of 1.1 nm/hr or less are obtained.

In an embodiment, with reference to FIG. 4 , a manufacturing process for coating a substrate is further described in detail below. Through a series of experiments, it was found that reducing the RF power increases the corrosion resistance of the film for a given gas flow rate when using hexane as the source gas. Furthermore, when this reduction in RF power is combined with a reduction in gas flow rate, the resulting film will have good corrosion resistance with high hardness values. As discussed herein, the substrate holder WT includes a plurality of burls (see, eg, FIG. 3B ) protruding from the substrate holder, each burl having a distal end surface configured to engage a substrate.

In an embodiment, operation P401 includes applying a coating of a wear resistant material to a distal end surface of one or more burls of the plurality of burls via plasma enhanced chemical vapor deposition. In an embodiment, action P401 includes several sub-actions, eg P403 and P405.

In an embodiment, operation P403 includes adjusting the radio frequency (RF) power of the RF electrode in the range of 100 to 1,000 W to generate the plasma. In an embodiment, operation P403 includes exposing the one or more plurality of burls to a precursor gas at a gas flow rate of 20 to 300 seem (eg, 20 to 200 seem) in the chamber, wherein the precursor gas is hexane. In an embodiment, the chamber has a geometry described for the distance between different components within the chamber. For example, the distance or diameter inside the chamber (eg, see D1 in FIG. 5 ), the distance between the top of the chamber and the turntable TT (eg, see D2 in FIG. 5 ), the substrate holder and gas distribution. distance between lines (eg, see D3 in Fig. 5) or other suitable geometric measure. In an example, in FIG. 5 , distance D1 may be about 23 inches, distance D2 may be about 6 inches, and distance D3 may be about 5.25 inches. It is to be understood that the geometry of the chamber is presented as an example and that other geometries of the chamber may be used.

In an embodiment, the operation P401 of applying the coating is performed at a vacuum level of the chamber in which the substrate holder is disposed, ranging from 1×10 ^-3 to 5×10 ^-2 mbar; or of a turn-table speed of the table on which the substrate holder is placed, ranging from 5 to 100 rpm; Further comprising adjusting one or more process parameters including at least one.

In an embodiment, the coating with the wear resistant material comprises a distal end surface of one or more of the plurality of burls; a coefficient of friction of the resulting coating in the range of 0.05 to 0.5; a surface of the resulting coating having a high spot of less than 10 nm and a thickness uniformity across a plurality of burls of the substrate holder within a range of 10% for a coating thickness across a diameter of 300 nm or less; or a wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to the reference; have at least one more characteristic among them.

In an embodiment, the wear resistant material is one of diamond-like carbon (DLC). In an embodiment, DLC is: (i) B-, N-, Si-, O-, F-, S-doped DLC, and/or (ii) Ti, Ta, Cr, W, Fe, Cu, Nb , metal-doped DLC doped with Zr, Mo, Co, Ni, Ru, Al, Au or Ag. In an embodiment, a combination of DLC materials may be used to form the wear resistant material.

In an embodiment, the coating of wear-resistant material causes the distal surface of one or more burls to have a hardness characteristic in the range of 20 GPa to 27 GPa and a corrosion rate characteristic in the range of 0.1 nm/hr to 1.5 nm/hr, wherein the corrosion rate is relative to the working electrode. It was characterized by chronoamperometry measured in a three-electrode electrochemical cell with a potential difference of about +2.5 V between counter electrodes and applied against a reference electrode in dilute NaCl solution. Coating with hexane may include 50 to 65% sp ³ and 25 to 35% hydrogen.

In an embodiment, the hardness is measured by a nano indentation method, where the measurement is performed using a diamond Berkovich tip using a nano-DMA transducer, and the indentation depth is determined by the coating It is kept to less than 10% of the thickness. In an embodiment, the thickness of the coating is 200 nm to 3 microns.

In an embodiment, the method 400 further includes an operation P410 comprising cleaning the plurality of burls with argon (Ar) gas prior to applying the coating. In an embodiment, the cleaning step includes generating a plasma at about 1000 W RF power using Ar gas; and adjusting the Ar gas flow rate between 75 sccm for 100 seconds. In an embodiment, the method 400 may include gradually decreasing the Ar flow rate and simultaneously increasing the hexane flow rate; and gradually tuning the RF power from 100 to 1000 W to apply the coating.

In an embodiment, the method 400 may be performed for different precursor gases (eg, acetylene gas) and process settings, as discussed below. For example, the method 400 may be modified as follows. Operation P401 includes applying, via plasma enhanced chemical vapor deposition, a coating of a wear resistant material to the distal end surface of one or more burls of the plurality of burls. Applying the coating may include adjusting the radio frequency (RF) power of the RF electrode in the range of 50 to 750 W to generate a plasma (eg, a variation on operation P403); and in the chamber, exposing the one or more plurality of burls to a precursor gas at a gas flow rate of 10 to 100 sccm (eg, variant in operation P405), wherein the precursor gas is acetylene. In an embodiment, a coating using acetylene results in a coating having a relatively higher hardness (than hexane), for example a hardness of greater than 25 to 35 GPa, and a corrosion resistance of 0.1 to 2 nm/hr can be achieved. can The coating using acetylene may include 60 to 80% sp ³ and 20 to 30% hydrogen.

In an embodiment, the application of the coating is carried out with a vacuum level of the chamber in which the substrate holder is placed, ranging from 1×10 ^-3 to 5×10 ^-2 mbar; or of a turn-table speed of the table on which the substrate holder is placed, ranging from 5 to 100 rpm; It may further include adjusting one or more process parameters including at least one. In an embodiment, the coating with the wear resistant material comprises a distal end surface of one or more of the plurality of burls; a coefficient of friction of the resulting coating in the range of 0.05 to 0.5; a surface of the resulting coating having a high spot of less than 10 nm and having a thickness uniformity across a plurality of burls of the substrate holder within a range of 10% for a coating thickness across a diameter of 300 nm or less; or a wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to the reference; have at least one more characteristic among them.

In an embodiment, the method 400 may include a first coating using hexane as a precursor gas as described above and a second coating using acetylene as a precursor gas as described above distal to one or more of the plurality of burls. It can be modified to be applied to the termination surface. For example, referring to FIG. 3B , the first coating unit may include a coating unit using hexane, and the second coating unit may include a coating unit using acetylene. A first coating using hexane as a precursor gas may be applied to a distal end surface of one or more of the plurality of burls, 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 a wear resistant material to a distal end surface of one or more burls of a plurality of burls via plasma enhanced chemical vapor deposition. Applying the first coating comprises adjusting the radio frequency (RF) power of the RF electrode in the range of 100 to 1000 W to generate a plasma, and the precursor gas at a gas flow rate of 20 to 300 sccm in one or more plurality of burls in the chamber. and the precursor gas is hexane. The first layer may include features similar to those of the coating portion using hexane described above. The method 400 may further include applying a second coating of a wear resistant material (e.g., to the first coating) to the distal end surface of one or more of the plurality of burls via plasma enhanced chemical vapor deposition. can Applying the second coating comprises adjusting the radio frequency (RF) power of the RF electrode in the range of 50 to 750 W to generate a plasma, and in the chamber, one or more plurality of burls to the precursor at a gas flow rate of 10 to 100 sccm. gas, wherein the precursor gas is acetylene. The second coating unit may include features similar to those of the coating unit using acetylene described above.

In an embodiment, the method 400 may be modified to provide a precursor gas selected from cyclohexane, n-hexane, or a mixture of a carbon-rich gas and a hydrogen-rich gas. For example, the mixture of carbon-rich gas and hydrogen-rich gas includes at least one of 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 so that burls with a coating having a hardness greater than 21 GPa and a corrosion resistance of 0.1 to 2 nm/hr can be achieved.

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

5 depicts an exemplary reactor 500 used to perform a plasma enhanced chemical vapor deposition process to apply a coating on a substrate holder. The PE-CVD process requires tight control of many parameters to obtain the desired coating properties. For example, control parameters include, but are not limited to, pressure (p), gas flow, discharge excitation frequency (f), and power (P). During deposition, bulk plasma parameters generally control the rate at which chemically active molecular fragments - free radicals and energetic species such as electrons and ions - are generated and accelerated under potential towards the substrate surface exposed to the plasma. Even for relatively simple gas mixtures, several plasma reactions occur and several new species of coatings are created. However, in most cases reaction kinetics are not readily available, making theoretical simulations of the process inefficient and inaccurate. For this reason, an empirical approach to process optimization is used to determine process recipes that result in desired material properties.

In Figure 5, 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 the 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 created by controlling the radio frequency (RF) power to the RF electrode. For example, the RF power may be 100 to 1,000 W or 50 to 750 W.

The chamber CBR includes a gas distribution line GD, and the precursor gas is supplied to the chamber CBR through this line. In an embodiment, the gas is hexane, acetylene, or other gas discussed herein. In the example, the gas flow rate of hexane is controlled between 20 and 300 sccm, while the RF power is controlled between 100 and 1,000 W. In another example, the gas flow rate of acetylene is controlled at 10 to 100 sccm and the RF power may be 50 to 750 W.

In an embodiment, reactor 500 may be connected to vacuum system VS to control the vacuum level of chamber CBR. In an embodiment, the reactor 500 is connected to a gas inlet and gases such as argon (Ar) and oxygen (O) may be supplied to the chamber CBR through the gas inlet. In an embodiment, a gas may be supplied to clean the substrate holder WT prior to applying a coating thereon.

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

In an embodiment, the chamber has the geometry described for the different components within the chamber. For example, the geometry may include the distance D1 or diameter D1 inside the chamber, the distance D2 between the top of the chamber and the turntable TT, and the distance D3 between the substrate or turntable and the gas distribution line ( FIG. 5 D3 of ) or other appropriate geometric measurements. In an example, in FIG. 5 , distance D1 may be about 23 inches, distance D2 may be about 6 inches, and distance D3 may be about 5.25 inches. It is to be understood that the geometry of the chamber is presented as an example and that other geometries of the chamber may be used.

Supporting examples 1, 2 and 3 of the process parameters used in the PE-CVD process and the resulting coatings are discussed below.

In Example 1, Si and SiSiC substrates (eg, burls) are coated with an approximately 650 nm DEC film 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 coating was uniform and dense. The hardness of this coating was measured between 23±1.5 GPa using a hysitron nano-indenter equipped with a diamond Berkovich tip at a maximum contact depth of <50 nm. In addition, the corrosion properties of this coating were characterized using chronoamperometry measured in a three-electrode electrochemical cell with a potential difference of +2.5 V between the working and counter electrodes and applied against a reference electrode in dilute NaCl solution. It became. The calculated corrosion rate was determined to be 1.1 nm/hr. These values represent approximately 15% and 250% increases in hardness and corrosion resistance, respectively, when compared to standard DEC coatings deposited using factory set power and gas flow parameters of approximately 1500 W and 300 sccm, respectively.

In Example 2, Si and SiSiC substrates (eg, burls) are coated with an approximately 650 nm DEC film using acetylene as the source gas. This coating run was performed using an acetylene flow rate of 50 sccm and an RF power of 300 W. The resulting coating was uniform and dense. The hardness of this coating was measured between 28 ± 1.5 GPa using a high-citron nano-indenter equipped with a diamond Berkovich tip at a maximum contact depth of <50 nm. In addition, the corrosion properties of this coating were characterized using chronoamperometry measured in a three-electrode electrochemical cell with a potential difference of +2.5 V between the working and counter electrodes and applied against a reference electrode in dilute NaCl solution. It became. The calculated corrosion rate was determined to be 1.6 nm/hr. These values represent approximately 40% and 250% increases in hardness and corrosion resistance, respectively, when compared to standard DEC films deposited using factory set power and gas flow parameters of approximately 1500 W and 300 sccm, respectively.

In Example 3, Si and SiSiC substrates (eg, burls) are coated with an approximately 650 nm DLC film using acetylene as the source gas. This coating run was performed using an acetylene flow rate of 30 sccm and an RF power of 150 W. The resulting coating was uniform and dense. The hardness of this coating was measured between 31 ± 1.5 GPa using a high-citron nano-indenter equipped with a diamond Berkovich tip at a maximum contact depth <50 nm. In addition, the corrosion properties of this coating were characterized using chronoamperometry measured in a three-electrode electrochemical cell with a potential difference of +2.5 V between the working and counter electrodes and applied against a reference electrode in dilute NaCl solution. It became. The calculated corrosion rate was determined to be 1.6 nm/hr. These values represent approximately 40% and 250% increases in hardness and corrosion resistance, respectively, when compared to standard DEC films deposited using factory set power and gas flow parameters of approximately 1500 W and 300 sccm, respectively.

In an embodiment, a substrate holder manufactured according to the method of FIG. 4 (see, eg, FIGS. 3A and 3B ) is provided. A substrate holder for use in a lithographic apparatus and configured to support a substrate includes a body (eg, SiSiC) having a body surface and a plurality of burls protruding from the body surface. In an embodiment, each burl has a distal end surface configured to engage a substrate; a distal end surface of the burl substantially conforms to a support plane and is configured to support a substrate; and a distal end surface of at least one of the plurality of burls is coated with a wear-resistant material having a hardness in the range of 20 to 27 GPa or 25 to 35 GPa and a corrosion rate in the range of 0.1 to 2 nm/hr, the corrosion rate being that of the working electrode. It was measured by chronoamperometry measured in a three-electrode electrochemical cell with a potential difference of +2.5 V between counter electrodes and applied against a reference electrode in dilute NaCl solution. In an embodiment, the distal end surface has a hardness in the range of 20 to 27 GPa and a corrosion rate in the range of 0.1 to 2 nm/hr.

As previously discussed, the distal end surface has a hardness in the range of 25 to 35 GPa and a corrosion rate in the range of 0.1 to 1.5 nm/hr. As previously discussed, hardness is measured, for example, by nanoindentation. Measurements are performed using a diamond Berkovich tip using a nano-DMA transducer and an indentation depth that remains less than 10% of the coating thickness. In an embodiment, the thickness of the coating is 200 nm to 3 microns. In an embodiment, the wear resistant material is one of diamond-like carbon (DLC). In an embodiment, DLC is: (i) B-, N-, Si-, O-, F-, S-doped DLC, and/or (ii) Ti, Ta, Cr, W, Fe, Cu, Nb , metal-doped DLC doped with Zr, Mo, Co, Ni, Ru, Al, Au or Ag.

In an embodiment, the distal end surface has a coefficient of friction of the resulting coating in the range of 0.05 to 0.5; a surface of the resulting coating having a thickness uniformity across the plurality of burls of the substrate holder within a range of 10% for nano bumps of less than 10 nm and coating thickness across a diameter of 300 nm or less; or a wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to the reference; It has at least one more characteristic of

Although the concepts disclosed herein can be used for imaging on substrates such as silicon wafers, the concepts disclosed can be used with any type of lithographic imaging system, for example, those used for imaging on substrates other than silicon wafers. point should be understood.

Embodiments may be further described using the following terms:

1. Provided is a method of manufacturing a substrate holder for use in a lithographic apparatus, the substrate holder comprising a plurality of bruls protruding from the substrate holder, each burl having a distal end surface configured to engage a substrate. and this method,

applying a coating of a wear resistant material to a distal end surface of one or more of the plurality of burls via plasma enhanced chemical vapor deposition;

The application of the coating is:

adjusting the radio frequency (RF) power of the RF electrode in the range of 100 to 1000 W to generate a plasma; and

exposing the one or more plurality of burls in the chamber to a precursor gas, wherein the precursor gas is hexane, at a gas flow rate of 20 to 300 sccm.

2. In the method of clause 1, the application of the coating is,

a vacuum level in the chamber in which the substrate holder is placed, ranging from 1×10 ⁻³ to 5×10 ⁻² mbar; or

of the turn-table speed of the table on which the substrate holder is placed, ranging from 5 to 100 rpm; Further comprising adjusting one or more process parameters including at least one.

3. The method of any one of clauses 1 and 2, wherein the coating with the wear resistant material comprises a distal end surface of at least one of the plurality of burls;

a coefficient of friction of the resulting coating in the range of 0.05 to 0.5;

a surface of the resulting coating having a high spot of less than 10 nm and a thickness uniformity across a plurality of burls of the substrate holder within a range of 10% for a coating thickness across a diameter of 300 nm or less; or

Wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to the reference; have at least one more characteristic among them.

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

5. The method of clause 4 wherein the DLC is: (i) B-, N-, Si-, O-, F-, S-doped DLC, and/or (ii) Ti, Ta, Cr, W, Fe , metal-doped DLC doped with Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au or Ag.

6. The method of any one of clauses 1 to 5, wherein the coating of wear resistant material has a distal surface of at least one burl having a hardness characteristic in the range of 20 GPa to 27 GPa and a corrosion rate characteristic in the range of 0.1 nm/hr to 2 nm/hr. , and the corrosion rate is measured by potentiostat chronoamperometry at about +2.5V in dilute NaCl solution.

7. The method of any one of clauses 1 to 6, wherein the hardness is measured by nano indentation and the measurement is performed using a diamond Berkovich tip using a nano-DMA transducer and the indentation depth is kept less than 10% of the coating thickness.

8. The method of any one of clauses 1 to 7, wherein the coating has a thickness of 200 nm to 3 microns.

9. The method of any one of clauses 1-8 further comprises cleaning the plurality of burls with argon (Ar) gas prior to applying the coating.

10. In the method of clause 9, cleaning is

generating a plasma at about 1000 W RF power using Ar gas; and

Further comprising adjusting the Ar gas flow rate between 75 sccm for 100 seconds.

11. The method of clause 10:

gradually decreasing the Ar flow rate and simultaneously increasing the hexane flow rate; and

Further comprising gradually tuning the RF power from 100 W to 1000 W to apply the coating.

12. The method of any one of clauses 1 to 11, wherein the chamber

diameter of the inside of the chamber;

the distance between the top of the chamber and the turntable; and/or

It has a geometry characterized by the distance between the substrate or turntable and the gas distribution line.

13. A method of manufacturing a substrate holder for use in a lithographic apparatus, wherein the substrate holder includes a plurality of burls projecting from the substrate holder, each burl having a distal end surface configured to engage a substrate, the present disclosure Way,

applying a coating of a wear resistant material to a distal end surface of one or more of the plurality of burls via plasma enhanced chemical vapor deposition;

The application of the coating is:

adjusting the radio frequency (RF) power of the RF electrode in the range of 50 to 750 W to generate a plasma; and

exposing the one or more plurality of burls in the chamber to a precursor gas, wherein the precursor gas is acetylene, at a gas flow rate of 10 to 100 sccm.

14. In the method of clause 13, the application of the coating is

a vacuum level in the chamber in which the substrate holder is placed, ranging from 1×10 ⁻³ to 5×10 ⁻² mbar; or

of the turn-table speed of the table on which the substrate holder is placed, ranging from 5 to 100 rpm; Further comprising adjusting one or more process parameters including at least one.

15. The method of any one of clauses 13 and 14, wherein the coating with the wear resistant material comprises a distal end surface of one or more of the plurality of burls;

a coefficient of friction of the resulting coating in the range of 0.05 to 0.5;

a surface of the resulting coating having nano-bumps of less than 10 nm and having a thickness uniformity across a plurality of burls of the substrate holder within a range of 10% for a coating thickness across a diameter of 300 nm or less; or

Wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to the reference; have at least one more characteristic among them.

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

17. The method of clause 16, wherein the DLC is: (i) B-, N-, Si-, O-, F-, S-doped DLC, and/or (ii) Ti, Ta, Cr, W, Fe , metal-doped DLC doped with Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au or Ag.

18. The method of any of clauses 13 to 17, wherein the coating of wear resistant material has a distal surface of at least one burl having hardness characteristics in the range of 25 GPa to 35 GPa and corrosion rate characteristics in the range of 0.1 nm/hr to 2 nm/hr. , and the corrosion rate was measured by chronoamperometry in a three-electrode electrochemical cell with a potential difference of about +2.5 V between the working and counter electrodes and applied to the reference electrode in dilute NaCl solution.

19. The method of any one of clauses 13 to 18, wherein the hardness is measured by nano-indentation, the measurement is performed using a diamond Berkovich tip using a nano-DMA transducer, and the indentation depth is determined by the coating It is kept to less than 10% of the thickness.

20. The method of any one of clauses 13 to 19 wherein the thickness of the coating is between 200 nm and 3 microns.

20. The method of any of clauses 13-19 further comprises purging the plurality of burls with argon (Ar) gas prior to applying the coating.

22. In the method of clause 21, cleaning

generating a plasma at about 1000 W RF power using Ar gas; and

Further comprising adjusting the Ar gas flow rate between 75 sccm for 100 seconds.

23. The method of clause 22:

gradually decreasing the Ar flow rate and simultaneously increasing the hexane flow rate; and

Further comprising gradually tuning the RF power from 100 W to 1000 W to apply the coating.

24. The method of any one of clauses 13 to 23, wherein the chamber

diameter of the inside of the chamber;

the distance between the top of the chamber and the turntable; and/or

It has a geometry characterized by the distance between the substrate or turntable and the gas distribution line.

25. A substrate holder is provided for use in a lithographic apparatus and configured to support a substrate, the substrate holder comprising:

a body having a body surface; and

Includes a plurality of burls protruding from the surface of the body,

each burl has a distal end surface configured to engage a substrate;

a distal end surface of the burl substantially conforms to a support plane and is configured to support a substrate; And

a distal end surface of at least one of the plurality of burls is coated with a wear-resistant material having a hardness in the range of 20 to 27 GPa or 25 to 35 GPa and a corrosion rate in the range of 0.1 to 2 nm/hr;

Corrosion rates were measured by chronoamperometry in a three-electrode electrochemical cell with a potential difference of about +2.5 V between the working and counter electrodes and applied against a reference electrode in dilute NaCl solution.

26. The substrate holder of clause 25, wherein the distal end 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.

27. The substrate holder of clause 26, wherein the distal end 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.

28. The substrate holder of any of clauses 25 to 27, wherein the distal end surface

a coefficient of friction of the resulting coating in the range of 0.05 to 0.5;

a surface of the resulting coating having nano-bumps of less than 10 nm and having a thickness uniformity across a plurality of burls of the substrate holder within a range of 10% for a coating thickness across a diameter of 300 nm or less; or

Wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to the reference; It has at least one more characteristic of

29. The substrate holder of any of clauses 25 to 28, wherein the hardness is measured by nano-indentation, the measurement is performed using a diamond Berkovich tip using a nano-DMA transducer, and the indentation depth is determined by coating It is maintained at less than 10% of the section thickness.

30. The substrate holder of any of clauses 25 to 29, wherein the coating has a thickness of 200 nm to 3 microns.

31. The substrate holder of any of clauses 25 to 30, wherein the wear resistant material is diamond-like carbon (DLC).

32. In the substrate holder of clause 31, the DLC is: (i) B-, N-, Si-, O-, F-, S-doped DLC, and/or (ii) Ti, Ta, Cr, W, metal-doped DLC doped with Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au or Ag.

33. A method of manufacturing a substrate holder for use in a lithographic apparatus, wherein the substrate holder includes a plurality of bruls protruding from the substrate holder, each burl having a distal end surface configured to engage a substrate, the method comprising: This method,

applying, via plasma enhanced chemical vapor deposition, a first coating of a wear resistant material to a distal end surface of one or more burls of the plurality of burls;

- the application of the first coating is:

adjusting the radio frequency (RF) power of the RF electrode in the range of 100 to 1000 W to generate a plasma; and

exposing, in the chamber, one or more plurality of burls to a precursor gas, wherein the precursor gas is hexane, at a gas flow rate of 20 to 300 sccm;

applying a second coating of a wear resistant material to a distal end surface of one or more of the plurality of burls via plasma enhanced chemical vapor deposition;

- the application of the second coating is:

adjusting the radio frequency (RF) power of the RF electrode in the range of 50 to 750 W to generate a plasma; and

In the chamber, at least one plurality of burls is exposed to a precursor gas, the precursor gas comprising acetylene, at a gas flow rate of 10 to 100 sccm.

The above description is intended to be illustrative rather than limiting. Accordingly, it will be apparent to those skilled in the art that modifications may be made as described without departing from the scope of the claims set forth below.

Claims (15)

A method of manufacturing a substrate holder for use in a lithographic apparatus, the substrate holder comprising a plurality of bruls protruding from the substrate holder, each burl having a distal end surface configured to engage a substrate. ,
applying a coating of a wear resistant material to the distal end surface of one or more of the plurality of burls via plasma enhanced chemical vapor deposition;
Application of the coating is:
adjusting the radio frequency (RF) power of the RF electrode in the range of 100 to 1000 W to generate a plasma; and
A method of manufacturing a substrate holder comprising exposing one or more plurality of burls in a chamber to a precursor gas, wherein the precursor gas is hexane, at a gas flow rate of 20 to 300 sccm. The method of claim 1, wherein the application of the coating is
a vacuum level of the chamber in which the substrate holder is placed in the range of 1×10 ^-3 to 5×10 ^-2 mbar; or
of the turn-table speed of the table on which the substrate holder is placed, in the range of 5 to 100 rpm; A method of manufacturing a substrate holder further comprising adjusting one or more process parameters including at least one. 3. The coating of any one of claims 1 and 2, wherein the coating with a wear resistant material is formed on the distal end surface of the one or more plurality of burls;
a coefficient of friction of the resulting coating in the range of 0.05 to 0.5;
a surface of the resulting coating having a high spot of less than 10 nm and having a thickness uniformity across the plurality of burls of the substrate holder within a range of 10% for a coating thickness across a diameter of 300 nm or less; or
a wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to a reference; A method for manufacturing a substrate holder that further has at least one characteristic of 4. The method according to any one of claims 1 to 3, wherein the wear resistant material is diamond-like carbon (DLC) and/or the DLC is: (i) B-, N-, Si-, O-, F- , S-doped DLC, and/or (ii) metal-doped DLC doped with Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au or Ag. A method for manufacturing a substrate holder comprising: According to any one of claims 1 to 4,
The coating of the wear resistant material causes the distal surface of the one or more burls to have a hardness characteristic in the range of 20 GPa to 27 GPa and a corrosion rate characteristic in the range of 0.1 nm/hr to 2 nm/hr, the corrosion rate being dilute NaCl measured by potentiostat chronoamperometry at about +2.5 V in solution; and/or
The hardness is measured by nano indentation,
The measurement is performed using a diamond Berkovich tip using a nano-DMA transducer, and the indentation depth is maintained at less than 10% of the coating thickness. According to any one of claims 1 to 5,
Cleaning the plurality of burls with argon (Ar) gas before applying the coating - The cleaning is performed using Ar gas to generate plasma at about 1000 W RF power, and Ar gas flow rate to 75 sccm for 100 seconds. Including coordinating between-;.
gradually decreasing the Ar flow rate and simultaneously increasing the hexane flow rate; and
and gradually tuning the RF power from 100 W to 1000 W to apply the coating. 7. The method of any one of claims 1 to 6, wherein the chamber
diameter of the inside of the chamber;
the distance between the top of the chamber and the turntable; and/or
Distance between the substrate or the turntable and the gas distribution line
Method for manufacturing a substrate holder having a geometry characterized by A method of manufacturing a substrate holder for use in a lithographic apparatus, the substrate holder comprising a plurality of burls protruding from the substrate holder, each burl having a distal end surface configured to engage a substrate, comprising:
applying a coating of a wear resistant material to the distal end surface of one or more of the plurality of burls via plasma enhanced chemical vapor deposition;
Application of the coating is:
adjusting the radio frequency (RF) power of the RF electrode in the range of 50 to 750 W to generate a plasma; and
A method of manufacturing a substrate holder comprising exposing, in a chamber, at least one plurality of burls to a precursor gas, wherein the precursor gas is acetylene, at a gas flow rate of 10 to 100 sccm. The method of claim 8, wherein the application of the coating part,
a vacuum level of the chamber in which the substrate holder is placed in the range of 1×10 ^-3 to 5×10 ^-2 mbar; or
of the turn-table speed of the table on which the substrate holder is placed, in the range of 5 to 100 rpm; A method of manufacturing a substrate holder further comprising adjusting one or more process parameters including at least one. 10. The method of any one of claims 8 and 9, wherein the coating with a wear-resistant material is formed on the distal end surface of the one or more plurality of burls;
a coefficient of friction of the resulting coating in the range of 0.05 to 0.5;
The resulting coating portion having a nano-bump of less than 10 nm and having a thickness uniformity across the plurality of burls of the substrate holder within 10% for a coating thickness across a diameter of 300 nm or less. surface; or
a wafer load grid in the range of 0.1 to 1.5 nm, wherein the wafer load grid is the positioning error of the substrate relative to a reference; A method for manufacturing a substrate holder that further has at least one characteristic of 11. The method of any one of claims 8 to 10, wherein the wear resistant material is diamond-like carbon (DLC) and/or the DLC is: (i) B-, N-, Si-, O-, F- , S-doped DLC, and/or (ii) metal-doped DLC doped with Ti, Ta, Cr, W, Fe, Cu, Nb, Zr, Mo, Co, Ni, Ru, Al, Au or Ag. A method for manufacturing a substrate holder comprising: According to any one of claims 8 to 11,
The coating of the wear resistant material causes the distal surface of the one or more burls to have a hardness characteristic in the range of 25 GPa to 35 GPa and a corrosion rate characteristic in the range of 0.1 nm/hr to 2 nm/hr, the corrosion rate being the working electrode Measured by chronoamperometry in a three-electrode electrochemical cell with a potential difference of about +2.5 V between V and the counter electrode and applied against a reference electrode in dilute NaCl solution; and/or
The hardness is measured by nanoindentation,
The measurement is performed using a diamond Berkovich tip using a nano-DMA transducer, and the indentation depth is maintained at less than 10% of the coating thickness. According to any one of claims 8 to 12,
Cleaning the plurality of burls with argon (Ar) gas before applying the coating - The cleaning is performed using Ar gas to generate plasma at about 1000 W RF power, and Ar gas flow rate to 75 sccm for 100 seconds. Including coordinating between-;.
gradually decreasing the Ar flow rate and simultaneously increasing the hexane flow rate; and
and gradually tuning the RF power from 100 W to 1000 W to apply the coating. 14. The method of any one of claims 8 to 13, wherein the chamber
diameter of the inside of the chamber;
the distance between the top of the chamber and the turntable; and/or
Distance between substrate or turntable and gas distribution line
Method for manufacturing a substrate holder having a geometry characterized by A substrate holder for use in a lithographic apparatus and configured to support a substrate, comprising:
a body having a body surface; and
Includes a plurality of burls protruding from the surface of the body,
each burl has a distal end surface configured to engage the substrate;
the distal end surface of the burl substantially conforms to a support plane and is configured to support a substrate; And
the distal end surface of at least one of the plurality of burls is coated with a wear-resistant material having a hardness in the range of 20 to 27 GPa or 25 to 35 GPa and a corrosion rate in the range of 0.1 to 2 nm/hr;
The corrosion rate was measured by chronoamperometry in a three-electrode electrochemical cell with a potential difference of about +2.5 V between the working electrode and the counter electrode and applied against a reference electrode in a dilute NaCl solution.

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