Apparatus for clamping a substrate onto a unipolar electrostatic chuck for photoresist film deposition.

Abstract

Apparatus for clamping a substrate onto a unipolar electrostatic chuck for photoresist film deposition is disclosed. In one example, the lift pin assembly includes a first metal spring, a first metal connected to the first metal spring above the first metal spring, a second metal spring connected to the first metal above the first metal, a second metal connected to the second metal spring above the second metal spring, and a ceramic connected to the second metal above the second metal.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 470,088, filed on May 31, 2023, and claims priority to U.S. Patent Application No. 18 / 628,136, filed on April 5, 2024, the entire content of which is incorporated herein by reference.

[0002] Embodiments of the present disclosure relate to the field of semiconductor processing, and more particularly, to an apparatus for clamping a substrate onto a monopole electrostatic chuck for photoresist film deposition.

Background Art

[0003] Description of Related Art Lithography has been used for decades in the semiconductor industry to create 2D and 3D patterns on microelectronic devices. The lithography process involves spin - on deposition of a film (photoresist), irradiating (exposing) the film with a selected pattern by an energy source, and removing (etching) either the exposed areas (positive tone) or non - exposed areas (negative tone) of the film by dissolving in a solvent. A bake is then performed to remove the remaining solvent.

[0004] The photoresist should be a radiation - sensitive material, and when irradiated, a chemical change occurs in the exposed portion of the film, enabling a change in solubility between the exposed and non - exposed regions. This change in solubility is used to remove either the exposed or non - exposed regions of the photoresist (etching). Then, the photoresist is developed and the pattern can be transferred to the underlying thin film or substrate by etching. After the pattern is transferred, the remaining photoresist is removed, and by repeating this process multiple times, 2D and 3D structures used in microelectronic devices can be obtained.

[0005] Several properties are important in the lithography process. These important properties include sensitivity, resolution, low line-edge roughness (LER), etching resistance, and the ability to form thinner layers. Higher sensitivity means less energy is required to change the solubility of the deposited film, which allows for increased efficiency in the lithography process. Resolution and LER determine how narrow features can be achieved in the lithography process. Pattern transfer to form deep structures requires materials with higher etching resistance. Materials with higher etching resistance also allow for thinner films, which increase the efficiency of the lithography process. [Overview of the project]

[0006] Embodiments disclosed herein include an apparatus for clamping a substrate onto a unipolar electrostatic chuck for photoresist film deposition.

[0007] In one embodiment, the lift pin assembly includes a first metal spring, a first metal connected to the first metal spring above the first metal spring, a second metal spring connected to the first metal above the first metal, a second metal connected to the second metal spring above the second metal spring, and a ceramic connected to the second metal above the second metal.

[0008] In one embodiment, a unipolar electrostatic chuck includes a chuck body, a plurality of lift pin holes in the chuck body, a plurality of lift pins, and individual lift pins among the plurality of lift pins in corresponding lift pin holes among the plurality of lift pin holes. Each of the plurality of lift pins includes a first metal spring, a first metal connected to the first metal spring above the first metal spring, a second metal spring connected to the first metal above the first metal, a second metal connected to the second metal spring above the second metal spring, and a ceramic connected to the second metal above the second metal.

[0009] In one embodiment, the system includes a chamber, a plasma source in or connected to the chamber, and a unipolar electrostatic chuck in the chamber. The unipolar electrostatic chuck includes a chuck body, a plurality of lift pin holes in the chuck body, a plurality of lift pins, and individual lift pins among the plurality of lift pins in corresponding lift pin holes among the plurality of lift pin holes. Each of the plurality of lift pins includes a first metal spring, a first metal connected to the first metal spring above the first metal spring, a second metal spring connected to the first metal above the first metal, a second metal connected to the second metal spring above the second metal spring, and a ceramic connected to the second metal above the second metal. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view illustrating various operations in a patterning process using a positive photoresist material formed by the process described herein, according to one embodiment of the present disclosure. [Figure 2A] This is a lift pin assembly according to one embodiment of the present disclosure. [Figure 2B] This is a flowchart of the operation in a method for chucking a wafer according to one embodiment of the present disclosure. [Figure 2C] This is a flowchart of the operation in a method for dechucking a wafer according to one embodiment of the present disclosure. [Figure 3] This is a cross-sectional view of a processing tool that may be used to carry out the dry deposition and oxidation process described herein, according to one embodiment of the present disclosure. [Figure 4] This is a cross-sectional view of a processing tool for depositing a photoresist layer on a substrate using a dry deposition and oxidation process, according to one embodiment of the present disclosure. [Figure 5] This is a magnified view of the edge of a movable column of a processing tool for depositing a photoresist layer on a substrate using a dry deposition and oxidation process, according to one embodiment of the present disclosure. [Figure 6A]This is a magnified view of the edge of a movable column in a processing tool, according to one embodiment of the present disclosure, when the shadow ring is not engaged with the edge ring. [Figure 6B] This is a magnified view of the edge of a movable column in a processing tool, in a case where the shadow ring is engaged with the edge ring, according to one embodiment of the present disclosure. [Figure 7A] This is a cross-sectional view of a processing tool for depositing a photoresist layer on a substrate using a dry deposition and oxidation process, according to one embodiment of the present disclosure. [Figure 7B] This is a cross-sectional view of a processing tool according to one embodiment of the present disclosure, in which the pedestal has been removed in order to expose a channel in a base plate. [Figure 8] This is a block diagram of an exemplary computer system according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0011] Apparatus for clamping a substrate onto a unipolar electrostatic chuck for photoresist film deposition is described herein. The following description includes numerous specific details, such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes, and material regimes for depositing photoresist, in order to provide a comprehensive understanding of the embodiments of the disclosure. Those skilled in the art will see that the embodiments of the disclosure can be implemented without these specific details. In other cases, well-known embodiments, such as the manufacture of integrated circuits, are not described in detail in order to avoid unnecessarily obscuring the embodiments of the disclosure. Furthermore, it should be understood that the various embodiments shown in the figures are illustrative and not necessarily drawn to scale.

[0012] To provide background, a unipolar electrostatic chuck (ESC) uses plasma on a wafer to chuck a wafer for de-chucking. According to the embodiments described herein, wafer chucking and de-chucking are performed by touching the wafer with a lift pin mechanism. This completes an electrical circuit comprising a high-voltage ESC power supply, ESC, wafer, and lift pin mechanism, enabling direct charge transfer in an optimal time.

[0013] To explain the background, the photoresist systems used in extreme ultraviolet (EUV) lithography have a problem of inefficiency. Specifically, existing photoresist material systems for EUV lithography require high doses to provide the solubility switch necessary to enable the development of the photoresist material. Traditionally, carbon-based films called organic chemically amplified photoresists (CARs) have been used as photoresists. However, very recently, organic-inorganic hybrid materials (metal-oxo) have been used as photoresists for extreme ultraviolet (EUV) radiation. Such materials typically contain metals (e.g., Sn, Hf, Zr), oxygen, and carbon. The shift from deep ultraviolet (DUV) to EUV in the lithography industry has facilitated the creation of narrow features with high aspect ratios. Metal-oxo-based organic-inorganic hybrid materials have been shown to exhibit lower line-edge roughness (LER) and higher resolution, which are necessary for forming narrow features. Furthermore, such films have higher sensitivity and etching resistance and can be manufactured for relatively thin films.

[0014] Currently, metal-oxophotoresists are deposited by spin-on methods involving wet chemical reactions. A post-bake process is required to remove residual solvent from the film and stabilize it. Furthermore, wet methods can generate large amounts of wet waste, which the industry wants to move away from. Photoresist films deposited by spin-on methods often suffer from heterogeneity problems. According to embodiments of this disclosure, apparatus and processes for vacuum deposition of metal-oxophotoresists that address one or more of the above problems are described herein.

[0015] According to one or more embodiments of the present disclosure, an apparatus for clamping a substrate on a unipolar electrostatic chuck is described herein. In one embodiment, a dry deposition and oxidation treatment approach for forming a photoresist film on a unipolar electrostatic chuck is described herein. In some embodiments, thermochemical vapor deposition (CVD) on a unipolar electrostatic chuck is used for dry deposition of the photoresist film. In other embodiments, plasma-enhanced chemical vapor deposition (PECVD) on a unipolar electrostatic chuck is used for dry deposition of the photoresist film. In one embodiment, the dry deposition process is not a condensation process. In another embodiment, the dry deposition process is a condensation process. In one embodiment of such a condensation process, the wafer / substrate is maintained at a temperature at which a metal precursor can be condensed. Condensation of the precursor can be achieved by maintaining the wafer temperature on the unipolar electrostatic chuck at a temperature lower than the ampoule temperature of the precursor.

[0016] Figure 1 shows a cross-sectional view illustrating various operations in a patterning process using a positive photoresist material formed by the process described herein, according to one embodiment of the present disclosure.

[0017] Referring to part (a) of FIG. 1, the starting structure 100 includes a positive photoresist layer 104 on a substrate or lower layer 102. In one embodiment, the positive photoresist layer 104 is deposited using dry deposition. Referring to part (b) of FIG. 1, a selected location of the starting structure 100 is irradiated 106 to form an irradiated photoresist layer 104A having an irradiated region 105B and a non-irradiated region 105A. Referring to part (c) of FIG. 1, a removal or etching process 108 is used to provide a developed photoresist layer in the non-irradiated region 105A. Referring to part (d) of FIG. 1, an etching process 110 using the non-irradiated region 105A as a mask is used to pattern the substrate or lower layer 102 to form a patterned substrate or patterned lower layer 102A including etched features 112.

[0018] Referring again to FIG. 1, the positive photoresist 104 is a radiation-sensitive material, and when irradiated, a chemical change occurs in the exposed portion of the film, and the solubility can change between the exposed region and the non-exposed region. Using the change in solubility, the exposed region of the positive photoresist is removed (etched). Next, the positive photoresist is developed and the pattern can be transferred to the underlying thin film or substrate by etching. After the pattern is transferred, the remaining positive photoresist is removed. By repeating this process multiple times, 2D and 3D structures for use in, for example, microelectronic devices can be fabricated. It should be understood that in other embodiments, the formation of a negative resist may be included.

[0019] According to one or more embodiments of the present disclosure, an apparatus for clamping a substrate on a monopole electrostatic chuck is described. Embodiments include substrate clamping on a monopole chuck. In one embodiment, there is an approach of grounding the wafer via a wafer lift pin so that the wafer can be chucked on the monopole chuck when there is no plasma or other external grounding device.

[0020] To explain the background, an electrostatic chuck relies on creating a potential difference between two surfaces (functioning as electrodes) to generate a clamping force on the substrate. The potential difference is typically generated by applying opposite polarities to the electrodes within the electrostatic chuck (bipolar chuck), or by applying only one polarity to the electrostatic chuck (unipolar chuck) and grounding the wafer through another device (edge ring, plasma, etc.).

[0021] According to one or more embodiments of the present disclosure, the approach described herein eliminates the need for an additional device to ground the substrate by adding electrical conduction and corrosion resistance functions to the substrate lift pins. In one embodiment, this approach involves controlling the contact between the wafer and the lift pins and connecting / disconnecting the contacts required for various applications. Embodiments may be directed to electrostatic chucks, substrate clamps, unipolar chucks, and / or wafer lift pins.

[0022] According to one embodiment of the present disclosure, an additional spring between each wafer lift pin and the lift gripper mechanism is included to ensure a consistent grounding path while providing compliance to the linear movement of the pins. In one embodiment, the device provides a grounding path to the wafer through the wafer lift assembly. Embodiments may be implemented to be resistant to corrosion and particle generation due to exposure to plasma and wafer contact.

[0023] According to one embodiment of the present disclosure, the need for an additional device to ground the substrate is eliminated by adding electrical conduction and corrosion resistance functions to the substrate lift pins. In one embodiment, these pin assemblies incorporate compliance to provide a desired contact pressure to ensure a constant contact with the back side of the substrate and achieve electrical conduction. In one embodiment, the above device, in combination with a unipolar electrostatic chuck, provides the force required to clamp the substrate.

[0024] One or more embodiments relate to a multi-material corrosion-resistant assembly having a conductive interface. One or more embodiments relate to a compliant assembly that ensures constant contact with a substrate and guided linear motion that enables accurate and repeatable substrate processing. One or more embodiments relate to a compliant device that provides contact pressure to achieve electrical conduction between a wafer and a lift assembly.

[0025] As an exemplary device, Figure 2A shows a lift pin assembly according to an embodiment of the present disclosure.

[0026] Referring to Figure 2A, the lift pin assembly 200 includes a metal spring 202. The metal spring 202 may be included for electrical conductivity. The metal spring 202 may provide a consistent grounding path. The metal spring 202 may provide responsiveness. The metal spring 202 may be conductive. The metal spring 202 may provide guided linear motion.

[0027] Referring again to Figure 2A, the lift pin assembly 200 includes metal 204. Metal 204 may be included for electrical conductivity, for interlocking with spring 202, for interlocking with metal pins, and / or for interlocking with grippers in the lift assembly. Metal 204 may be conductive. Metal 204 may provide guided linear motion.

[0028] Referring again to Figure 2A, the lift pin assembly 200 includes a metal spring 206. The metal spring 206 may be included to conduct electricity. The metal spring 206 may be included to provide conformability. The metal spring 206 may be included to provide back pressure. The metal spring 206 may be conductive. The metal spring 206 may provide contact pressure.

[0029] Referring again to Figure 2A, the lift pin assembly 200 includes metal 208. Metal 208 may be included for electrical conductivity, for guiding / supporting the spring, and / or for interlocking with metal pins for linear guidance. Metal 208 may be conductive. Metal 208 may provide guided linear motion.

[0030] Referring again to Figure 2A, the lift pin assembly 200 includes a ceramic 210 (e.g., SiC). The ceramic 210 may be included for supporting the wafer and / or for conducting electricity. The ceramic 210 may be corrosion-resistant. The ceramic 210 may be conductive. In another embodiment, a metal may be used instead of ceramic.

[0031] One or more embodiments described herein may be implemented to provide a chucking function to a unipolar electrostatic chuck (ESC) by providing a grounding path to the wafer via a wafer lift pin. The contact between the wafer and the lift pin can be controlled, and the connection / disconnection of the contact can be performed according to various applications. In one embodiment, an additional spring is included between the wafer lift pin and the lift gripper mechanism to ensure a consistent grounding path while providing responsiveness to the linear motion of the pin. Embodiments may be implemented to provide a grounding path for the wafer through the wafer lift assembly. Materials and surfaces exposed to the process environment may be resistant to corrosion from exposure to plasma and contact with the wafer, and resistant to particle generation.

[0032] Figure 2B is a flowchart 220 of the operation in a method for chucking a wafer according to an embodiment of the present disclosure. Referring to step 222, the substrate is placed in a raised position on a lift pin, such as a type 200 lift pin in Figure 2A. Referring to step 224, the lift pin is lowered to transfer the substrate to the electrostatic chuck. Referring to step 226, a clamping voltage is applied to the electrostatic chuck. Referring to step 228, the substrate is clamped.

[0033] Figure 2C is a flowchart 240 of the operation in a method for dechucking a wafer according to an embodiment of the present disclosure. Referring to step 242, the clamp voltage to the electrostatic chuck is turned off. Referring to step 244, the substrate is removed. Referring to step 246, the lift pins are raised to lift the substrate from the electrostatic chuck.

[0034] Advantages of carrying out the embodiments described herein may include eliminating the need for additional equipment to clamp wafers onto the unipolar electrostatic chuck. The corrosion-resistant features of the embodiments described herein enable their use in all semiconductor wafer manufacturing equipment that uses electrostatic chucking.

[0035] In another embodiment, the Sn precursor is used in the vacuum deposition process of the Sn oxo-PR material. SnOC films can be attractive photoresist films because of their high sensitivity to exposure. Generally, tin-oxo photoresist films contain Sn-O and Sn-C bonds within the SnOC network, and exposure (UV / EUV, etc.) breaks the Sn-C bonds, reducing the proportion of carbon in the film. This can lead to selective etching during the development process. Sn-C can be incorporated into the film by using a metal precursor having one or more Sn-C bonds. In one embodiment, the precursor described herein has a ligand (L) that has Sn-C (R contains C bonded to Sn) for exposure sensitivity and reacts with an oxidizing agent (e.g., water) to form a photoresist film. In one embodiment, the reactivity between the precursor and the oxidizing agent can be adjusted by changing R and / or L of the Sn precursor. Sensitivity can also be adjusted by changing the R group of the precursor. In one embodiment, an indium-oxo film or a tin-indium-oxo film may also be used as a photoresist film. The approach described herein can be extended to many other metal-containing films.

[0036] According to one embodiment of this disclosure, a photoresist is manufactured using a metal precursor or a specific type of R group by plasma-assisted deposition. As an example, a Sn precursor containing a phenyl group (R) (PhSn(NMe2)3) may be used. After exposing the resist to UV in the ambient environment, the exposed region by FTIR showed an acidic portion. The resist was then developed by immersion in an aqueous sodium hydroxide (NaOH) solution. The acidic portion (exposed region) of the resist reacted with basic NaOH, dissolving in an aqueous medium to yield a positive-type resist. Alternatively, using Sn(nBu)4 in PECVD yielded a positive-type resist. Thus, an approach for manufacturing a positive-type photoresist is described herein. However, in other embodiments, a negative-type photoresist can be manufactured.

[0037] In one embodiment, an R group with low radical stability is used. For example, the radicals of R groups such as phenyl, alkenyl, and methyl have low stability (Sn-C → Sn· + C·). In one embodiment, regarding the exposure environment, if the photoresist is exposed by an energy source (such as EUV), the exposure chamber (environment) may contain oxygen or be inert. In one embodiment, exposure is performed under vacuum using an oxygen source such as O2, H2O, CO2, CO, NO2, or NO. In one embodiment, the number of repetitions of EUV exposure and subsequent oxygen exposure may be between 1 and 100.

[0038] In one embodiment, post-annealing is performed in an oxygen-containing environment. In one embodiment, the oxygen source is O3, NO2, NO, or O2, which can be used to form a plasma and / or can be used together with N2, Ar, or He. In one embodiment, post-annealing is performed at a temperature in the range of 25 to 200 degrees Celsius. In one embodiment, post-annealing is performed at a pressure of less than 200 torr. In a particular embodiment, post-annealing is performed using ozone (O3) as the oxygen source gas, at a temperature in the range of 25 to 250 degrees Celsius, and at a pressure of less than 200 torr.

[0039] In one embodiment, the usable basic developer includes an inorganic base that can be prepared in water and whose concentration and development time can be adjusted. In one embodiment, this may be a group 1 or 2 hydroxide (e.g., NaOH, KOH), NH4OH, NaHCO3, NaCO3, N(CH3)4OH, or other amines.

[0040] In one embodiment, the oxidizing agent coreactant is selected from the group consisting of water, O2, N2O, NO, CO2, CO, ethylene glycol, alcohols (e.g., methanol, ethanol), peroxides (e.g., H2O2), and acids (e.g., formic acid, acetic acid).

[0041] In a first approach according to one embodiment of the present disclosure, a chemical vapor deposition (CVD) method for forming a photoresist involves (A) vaporizing one or more metal precursors and one or more of the oxidizing agents listed above in a vacuum chamber in which a substrate wafer is maintained at a predetermined substrate temperature. The substrate temperature can vary from 0°C to 500°C. When the precursors / oxidizing agents vaporize in the chamber, they may be diluted with an inert gas such as Ar, N2, or He. Due to the reactivity of the precursors and oxidizing agents, a metal oxo film is deposited on the wafer. Vaporization into the chamber can be performed by doing all the precursors simultaneously or by pulsed alternatingly the metal precursor(s) and oxidizing agents(s). This process can be described as thermal CVD. (B) Plasma can also be turned on during this process, and this process can then be described as plasma-enhanced (PE)-CVD. Examples of plasma sources include CCP, ICP, remote plasma, and microwave plasma. (C) The deposition of the photoresist film can be performed by plasma treatment after thermal deposition. In this case, the film is thermally deposited, followed by a plasma treatment operation. The plasma treatment may include plasma from inert gases such as Ar, N2, and He, or these gases may be mixed with O2, CO2, CO, NO, NO2, and H2O. The process can be carried out periodically, with plasma treatment following thermal deposition and this cycle repeated, or with one plasma treatment after the deposition is complete (post-treatment). PECVD followed by plasma treatment is also possible. In any case, in one embodiment, post-annealing is performed in an oxygen-containing environment. In one embodiment, post-annealing is performed using ozone (O3) as the oxygen source gas, at a temperature in the range of 25 to 250 degrees Celsius and a pressure of less than 200 torr.

[0042] In a second approach according to one embodiment of the present disclosure, the atomic layer deposition (ALD) method for forming a photoresist is as follows: (A) A metal precursor is vaporized into a vacuum chamber in which a substrate wafer is maintained at a predetermined substrate temperature. The substrate temperature can vary from 0°C to 500°C. A gas-to-gas purge is then provided to remove by-products and excess metal precursor. One or more oxidants are then vaporized into the chamber. The oxidants(s) react with the metal precursor absorbed on the surface. An inert gas purge is then applied to remove by-products and unreacted oxidants. This cycle can be repeated until a desired thickness is obtained. When the precursor or oxidant vaporizes into the chamber, it may be diluted with an inert gas such as Ar, N2, or He. This process can be described as thermal ALD. Using this method, multiple metals can be incorporated into the film by incorporating additional metal precursor pulses into the ALD cycle. Another oxidant can also be pulsed after the first oxidant. (B) A plasma can be turned on during the oxidant pulse, and the process can then be described as PE-ALD. (C) Alternatively, deposition can be carried out by thermal ALD followed by plasma treatment. In this case, the film is thermally deposited, and then the plasma treatment operation is performed. The plasma treatment may include plasma from inert gases such as Ar, N2, He, or these gases may be mixed with O2, CO2, CO, NO, NO2, H2O. This process can be carried out periodically. X thermal ALD cycles (X=1 to 5000) are followed by plasma treatment, and the entire cycle is repeated for the desired number of times, or the plasma treatment is performed once after the deposition portion is completed. PE-ALD followed by plasma treatment is also possible. In any case, in one embodiment, post-annealing is carried out in an oxygen-containing environment. In one embodiment, post-annealing is carried out using ozone (O3) as the oxygen source gas, at a temperature in the range of 25 to 250 degrees Celsius and a pressure of less than 200 torr.

[0043] In a third approach, according to one embodiment of the present disclosure, the atomic layer deposition (ALD) or chemical vapor deposition (CVD) method for forming a photoresist includes providing a compositional gradient across the entire film. For example, the first few nanometers of the film have a different composition from the rest of the film. While the main portion of the film can be optimized dose-dependently, a different composition near the interface layer can be targeted to modify adhesion, sensitivity to EUV photons, and sensitivity to developing chemicals in order to improve post-lithography profile control (particularly staining) and defect rate and resist decay / lift-off. The gradient may be optimized depending on the pattern type. For example, pillars may require increased adhesion for increased dose, while line / space patterns may require decreased adhesion.

[0044] In one embodiment, the photoresist film deposition method described herein is a vacuum deposition method that does not involve wet chemical action. Advantages of implementing one or more of the approaches described herein include the fact that the photoresist film deposition approach is a dry deposition approach and does not involve wet chemical action. Wet chemical processes can generate a large amount of wet byproducts, which are sometimes desirable to avoid. Also, spin-on (wet) processes often cause heterogeneity problems, which can be successfully addressed by the vacuum deposition methods described herein. Furthermore, vacuum deposition allows for the control of the metal-to-carbon (C) ratio in the film. In spin-on processes, the metal ratio and C are often fixed in a given deposition system. The precursors used to deposit photoresist films under vacuum must be volatile, and the precursors described herein are volatile based on their L and R structures. Dry deposition methods may require lower temperatures than other vacuum deposition methods such as ALD or CVD. Performing deposition at low temperatures can result in a relatively large amount of carbon being retained in the film, which can be beneficial for patterning.

[0045] In one embodiment, the vacuum deposition process relies on a chemical reaction between a metal precursor and an oxidizer. The metal precursor and oxidizer are vaporized into a vacuum chamber. In some embodiments, the metal precursor and oxidizer are supplied to the vacuum chamber together. In other embodiments, the metal precursor and oxidizer are supplied to the vacuum chamber in alternating pulses. After a metal oxophotoresist film of the desired thickness is formed, the process can be stopped. In one embodiment, after a metal oxophotoresist film of the desired thickness is formed, any plasma treatment operation may be performed.

[0046] In one embodiment, a metal oxophotoresist film having a desired thickness can be provided by repeating a cycle including pulses of metal precursor vapor and pulses of oxidizer vapor multiple times. In one embodiment, the order of the cycles can be changed. For example, the oxidizer vapor can be pulsed first, followed by the metal precursor vapor. In one embodiment, the pulse duration of the metal precursor vapor may be substantially the same as that of the oxidizer vapor. In other embodiments, the pulse duration of the metal precursor vapor may differ from that of the oxidizer vapor. In one embodiment, the pulse duration may be between 0 seconds and 1 minute. In a particular embodiment, the pulse duration may be between 1 second and 5 seconds. In one embodiment, each iteration of the cycle uses the same process gas. In other embodiments, the process gas can be changed between cycles. For example, the first cycle may utilize a first metal precursor vapor, and the second cycle may utilize a second metal precursor vapor. Subsequent cycles may continue alternately between the first and second metal precursor vapors. In one embodiment, multiple oxidizer vapors can be alternated between cycles in a similar manner. In one embodiment, any plasma treatment of the operation may be performed after all cycles. That is, each cycle may include a pulse of metal precursor vapor, a pulse of oxidizer vapor, and plasma treatment. In an alternative embodiment, any plasma treatment of the operation may be performed after multiple cycles. In yet another embodiment, any plasma treatment operation may be performed after the completion of all cycles (i.e., as post-treatment).

[0047] Providing a metal oxophotoresist film using the dry deposition and oxidation process described in the embodiments above offers significant advantages compared to wet chemical methods. One such advantage is the elimination of wet by-products. The dry deposition process eliminates liquid waste and simplifies the removal of by-products. Furthermore, the dry deposition process can provide a more uniform photoresist layer. Uniformity in this sense may refer to uniformity of thickness across the wafer and / or uniformity of the distribution of the metal component in the metal oxo film.

[0048] Furthermore, the use of a dry deposition process allows for fine-tuning of the proportion and composition of metals in the photoresist. The proportion of metals can be modified by increasing or decreasing the flow rate of the metal precursor into the vacuum chamber and / or by modifying the pulse length of the metal precursor / oxidant. The use of a dry deposition process also allows for the inclusion of multiple different metals in the metal oxo film. For example, a single pulse flowing through two different metal precursors can be used, or alternating pulses of two different metal precursors can be used.

[0049] Furthermore, metal oxophotoresists formed using a dry deposition process have been shown to be more resistant to thickness reduction after exposure. Without being tied to a specific mechanism, this resistance to thickness reduction is thought to be at least partially due to reduced carbon loss during exposure.

[0050] In one embodiment, the vacuum chamber used in the dry deposition process is any suitable chamber capable of providing a pressure lower than that of the atmosphere. In one embodiment, the vacuum chamber may include temperature control functions for controlling the temperature of the chamber walls and / or the temperature of the substrate. In one embodiment, the vacuum chamber may also include functions for providing plasma within the chamber. A more detailed description of a suitable vacuum chamber is provided below with reference to Figure 3. Figure 3 is a schematic diagram of a vacuum chamber configured to perform dry deposition of a metal oxophotoresist according to one embodiment of the present disclosure. It should be understood that the lift pins (one or more) described above in relation to Figure 2A may be implemented in embodiments described later in relation to Figure 3.

[0051] The vacuum chamber 300 includes a grounded chamber 305. The substrate 310 is loaded through the opening 315 and clamped to a temperature-controlled chuck 320. Although not shown, the chuck 320 may include a chuck body having a plurality of lift pin holes and corresponding lift pins among a plurality of lift pins. In one embodiment, the substrate 310 may be temperature-controlled during the dry deposition process. For example, the temperature of the substrate 310 may be between approximately -40°C and 200°C. In a particular embodiment, the substrate 310 may be held at a temperature between room temperature and 150°C.

[0052] Process gases are supplied from a gas source 344 to the interior of the chamber 305 through their respective mass flow controllers 349. In certain embodiments, a gas distribution plate 335 is provided for the distribution of process gases 344, such as metal precursors, oxidizers, and inert gases. The chamber 305 is exhausted via an exhaust pump 355. In one embodiment, one or more of the process gases are contained in / stored in one or more ampoules. In one embodiment, the dry deposition process is a chemical vapor condensation process, and one or more ampoules are maintained at a temperature higher than the substrate temperature, for example, 25°C or higher.

[0053] When RF power is applied during processing of the substrate 310, plasma is formed in the chamber processing area on the substrate 310. A bias power RF generator 325 is connected to a temperature-controlled chuck 320. The bias power RF generator 325 provides bias power to energize the plasma if desired. The bias power RF generator 325 may have a low frequency, for example, between about 2 MHz and 60 MHz, and in a particular embodiment, it is in the 13.56 MHz band. In a particular embodiment, the vacuum chamber 300 includes a third bias power RF generator 326 with a frequency in the about 2 MHz band. The bias power RF generator 326 is connected to the same RF matcher 327 as the bias power RF generator 325. A source power RF generator 330 is connected to a plasma generating element (e.g., a gas distribution plate 335) via a matcher (not shown) to supply source power and energize the plasma. The source RF generator 330 may have a frequency between 100 and 180 MHz, for example, and in a particular embodiment, a frequency in the 162 MHz band. Since the diameter of the substrate changes over time, such as 150 mm, 200 mm, 300 mm, etc., it is common practice in the art to standardize the source and bias power of the plasma etching system to match the substrate area.

[0054] The vacuum chamber 300 is controlled by a controller 370. The controller 370 may include a CPU 372, memory 373, and an I / O interface 374. The CPU 372 can execute processing operations within the vacuum chamber 300 according to instructions stored in memory 373. For example, one or more processes, such as processes 120 and 440 described above, can be executed within the vacuum chamber by the controller 370.

[0055] In another embodiment, embodiments disclosed herein include a processing tool having an architecture particularly suited for optimizing dry deposition. For example, the processing tool may include a pedestal for supporting a temperature-controlled wafer. In some embodiments, the temperature of the pedestal may be maintained between about -40°C and about 200°C. Furthermore, edge purge flow and shadowing may be provided around the column supporting the substrate. Edge purge flow and shadowing prevent photoresist from depositing along the edges or back of the wafer. In embodiments, the pedestal may also provide any desired chucking architecture, such as (but not limited to) vacuum chucking, unipolar chucking, or bipolar chucking, depending on the operating regime of the processing tool.

[0056] In some embodiments, the processing tool may be suitable for deposition processes that do not use plasma. Alternatively, the processing tool may include a plasma source that enables plasma-enhanced operation. Furthermore, while the embodiments disclosed herein are particularly suitable for the deposition of metal oxophotoresists for EUV patterning, it should be understood that embodiments are not limited to such configurations. For example, the processing tools described herein may be suitable for depositing any photoresist material for any form of lithography using a dry deposition process.

[0057] Referring here to Figure 4, a cross-sectional view of a processing tool 400 according to one embodiment is shown. It should be understood that the lift pins (one or more) described above in relation to Figure 2A may be implemented in embodiments described later in relation to Figure 4. In one embodiment, the processing tool 400 may include a chamber 405. The chamber 405 may be any suitable chamber capable of supporting a pressure lower than atmospheric pressure (e.g., vacuum pressure). In one embodiment, an exhaust system (not shown) including a vacuum pump may be connected to the chamber 405 to provide a pressure lower than atmospheric pressure. In one embodiment, a lid may seal the chamber 405. For example, the lid may include a showerhead assembly 440. The showerhead assembly 440 may include a fluid path that allows a processing gas and / or an inert gas to flow into the chamber 405. In some embodiments where the processing tool 400 is suitable for plasma enhancement operation, the showerhead assembly 440 may be electrically connected to an RF source and matching circuit 450. In yet another embodiment, the tool 400 may consist of an RF bottom supply architecture. In other words, the pedestal 430 is connected to an RF source, and the showerhead assembly 440 is grounded. In such an embodiment, the filtering circuit may still be connected to the pedestal. In one embodiment, the precursor gas is stored in an ampoule 499.

[0058] In one embodiment, a movable column for supporting a wafer 401 is provided within the chamber 405. In one embodiment, the wafer 401 may be any substrate on which a photoresist material is deposited. For example, the wafer 401 may be a 300 mm wafer or a 450 mm wafer, but other wafer diameters may also be used. Furthermore, in some embodiments, the wafer 401 may be replaced with a substrate having a non-circular shape. The movable column may include pillars 414 extending outside the chamber 405. The pillars 414 may have ports for providing electrical and fluid pathways to various components of the column from outside the chamber 405.

[0059] In one embodiment, the column may include a base plate 410. The base plate 410 may be grounded. As will be described in more detail below, the base plate 410 may include fluid channels that allow for the flow of an inert gas to provide edge-purge flow.

[0060] In one embodiment, an insulating layer 415 is placed on a base plate 410. The insulating layer 415 may be any suitable dielectric material. For example, the insulating layer 415 may be a ceramic plate. In one embodiment, a pedestal 430 is placed on the insulating layer 415. The pedestal 430 may consist of a single material, or the pedestal 430 may be formed from different materials. In one embodiment, the pedestal 430 may utilize any suitable chucking system to secure the wafer 401. For example, the pedestal 430 may be a vacuum chuck or a unipolar chuck. Although not shown, the pedestal may include a chuck body having a plurality of lift pin holes and corresponding lift pins among a plurality of lift pins.

[0061] The pedestal 430 may include a plurality of cooling channels 431. The cooling channels 431 may be connected to fluid inputs and fluid outputs (not shown) passing through pillars 414. In one embodiment, the cooling channels 431 allow the temperature of the wafer 401 to be controlled during the operation of the processing tool 400. For example, the cooling channels 431 may allow the temperature of the wafer 401 to be controlled between approximately -40°C and approximately 200°C. In one embodiment, the pedestal 430 is connected to the ground via a filtering circuit 445, which allows for DC and / or RF biasing of the pedestal to the ground.

[0062] In one embodiment, an edge ring 420 surrounds the insulating layer 415 and the pedestal 430. The edge ring 420 may be made of a dielectric material such as ceramic. In one embodiment, the edge ring 420 is supported by a base plate 410. The edge ring 420 may support a shadow ring 435. The shadow ring 435 has an inner diameter smaller than the diameter of the wafer 401. Thus, the shadow ring 435 prevents photoresist from being deposited on a portion of the outer edge of the wafer 401. A gap is provided between the shadow ring 435 and the wafer 401. This gap prevents the shadow ring 435 from contacting the wafer 401 and provides an exit for the edge purge flow, which will be described in more detail below. In one embodiment, a dual-channel showerhead may be used in the photoresist manufacturing process.

[0063] The shadow ring 435 provides some protection to the top surface and edges of the wafer 401, but the processing gas may flow / diffuse downward along the path between the edge ring 420 and the wafer 401. Therefore, embodiments disclosed herein may include a fluid path between the edge ring 420 and the pedestal 430 to enable edge purging flow. Providing an inert gas within the fluid path increases the local pressure within the fluid path, preventing the processing gas from reaching the edges of the wafer 401. Thus, deposition of photoresist along the edges of the wafer 401 is prevented.

[0064] Referring now to Figure 5, an enlarged cross-sectional view of a portion of column 560 in the processing tool according to one embodiment is shown. It should be understood that the lift pin(s) described above in relation to Figure 2A can be implemented in the embodiment described later in relation to Figure 5. In Figure 5, only the left edge of column 560 is shown. However, it should be understood that the right edge of column 560 can substantially reflect the left edge.

[0065] In one embodiment, the column 560 may include a base plate 510. An insulating layer 515 may be placed on the base plate 510. In one embodiment, the pedestal 530 may include a first portion 530A and a second portion 530B. A cooling channel 531 may be located within the second portion 530B. The first portion 530A may include a function for chucking the wafer 501. Although not shown, the first portion 530A may include a chuck body having a plurality of lift pin holes and corresponding lift pin holes among the plurality of lift pin holes.

[0066] In one embodiment, the edge ring 520 surrounds the base plate 510, the insulating layer 515, the pedestal 530, and the wafer 501. In one embodiment, the edge ring 520 is separated from other components of the column 550 to provide a fluid path 512 from the base plate 510 to the upper side of the column 560. For example, the fluid path 512 may exit the column between the wafer 501 and the shadow ring 535. In certain embodiments, the inner surface of the fluid path 512 includes the edge of the insulating layer 515, the edge of the pedestal 530 (i.e., the first portion 530A and the second portion 530B), and the edge of the wafer 501. In one embodiment, the outer surface of the fluid path 512 includes the inner edge of the edge ring 520. In one embodiment, the fluid path 512 may also continue over the upper surface of a portion of the pedestal 530 as it proceeds towards the edge of the wafer 501. Therefore, when an inert gas (e.g., helium, argon, etc.) flows through the fluid path 512, the processing gas is prevented from flowing / diffusing below the side surface of the wafer 501.

[0067] In one embodiment, the width W of the fluid path 512 is minimized to prevent plasma collisions along the fluid path 512. For example, the width W of the fluid path 512 may be about 1 mm or less. In one embodiment, a seal 517 prevents the fluid path 512 from exiting the bottom of the column 560. The seal 517 may be positioned between the edge ring 520 and the base plate 510. The seal 517 may be made of a flexible material such as gasket material. In certain embodiments, the seal 517 includes silicone.

[0068] In one embodiment, the channel 511 is located within the base plate 510. The channel 511 delivers an inert gas from the center of the column 560 to the inner edge of the edge ring 520. It should be noted that only a portion of the channel 511 is shown in Figure 5. A more comprehensive diagram of the channel 511 is provided below with respect to Figure 7B.

[0069] In one embodiment, the edge ring 520 and the shadow ring 535 may have features suitable for aligning the shadow ring 535 with respect to the wafer 501. For example, a notch 521 on the upper surface of the edge ring 520 may bond with a projection 536 on the lower surface of the shadow ring 535. The notch 521 and projection 536 may have tapered surfaces that allow for rough alignment of the two components, sufficient to provide more precise alignment when the edge ring 520 contacts the shadow ring 535. In a further embodiment, an alignment mechanism (not shown) may be provided between the pedestal 530 and the edge ring 520. The alignment mechanism between the pedestal 530 and the edge ring 520 may include a tapered notch and projection architecture similar to that of the alignment mechanism between the edge ring 520 and the shadow ring 535.

[0070] Referring now to Figures 6A and 6B, a pair of cross-sectional views are shown illustrating a part of a processing tool having a pedestal at different locations (in the Z direction) according to one embodiment. In Figure 6A, the pedestal is at a low position within the chamber. The position of the pedestal in Figure 6A is where the wafer is inserted into or removed from the chamber via the slit valve. In Figure 6B, the pedestal is at a raised position within the chamber. The position of the pedestal in Figure 6B is where the wafer is processed. It should be understood that the lift pin(s) described above in relation to Figure 2A may be implemented in embodiments described later in relation to Figures 6A and 6B.

[0071] Referring now to Figure 6A, a cross-sectional view of a movable column 660 in a first position according to one embodiment is shown. As shown in Figure 6A, the column includes a base plate 610, an insulating layer 615, a pedestal 630 (i.e., a first portion 630A and a second portion 630B), and an edge ring 620. Such components may be substantially the same as the components of similar names described above. For example, a cooling channel 631 may be provided in the second portion 630B of the pedestal 630, the channel 611 may be located within the base plate 610, and a seal 617 may be provided between the edge ring 620 and the base plate 610.

[0072] As shown in Figure 6A, the wafer 601 is placed on the upper surface of the pedestal 630. The wafer 601 can be inserted into the chamber via a slit valve (not shown). Furthermore, the shadow ring 635 is shown in a raised position above the edge ring 620. Since the inner diameter of the shadow ring 635 is smaller than the diameter of the wafer 601, the wafer 601 must be placed on the pedestal before the shadow ring 635 comes into contact with the edge ring 620.

[0073] In one embodiment, the shadow ring 635 is supported by a chamber liner 670, which can surround the outer circumference of the column 660. In one embodiment, a holder 671 is positioned on the upper surface of the chamber liner 670. The holder 671 is configured to hold the shadow ring 635 in a high position above the edge ring 620 when the column 660 is in a first position. In one embodiment, the shadow ring 635 includes a projection 636 for alignment with a notch 621 of the edge ring 620.

[0074] Referring here to Figure 6B, a cross-sectional view of the column 660 after the shadow ring 635 has been engaged is shown according to one embodiment. As shown, the column 660 is displaced vertically (i.e., in the Z direction) until the shadow ring 635 engages with the edge ring 620. Further vertical displacement of the column 660 lifts the shadow ring 635 from the holder 671 on the chamber liner 670. In one embodiment, the shadow ring 635 is properly aligned as a result of an alignment mechanism between the shadow ring 635 and the edge ring 620 (i.e., a notch 621 and a projection 636). In a further embodiment, an alignment mechanism (not shown) may be provided between the pedestal 630 and the edge ring 620. The alignment mechanism between the pedestal 630 and the edge ring 620 may include a tapered notch and projection architecture similar to the alignment mechanism between the edge ring 620 and the shadow ring 635.

[0075] While in the second position, the wafer 601 may be processed. In particular, the processing may include the deposition of photoresist material onto the upper surface of the wafer 601. For example, the process may be a dry deposition and oxidation process with or without plasma assistance. In certain embodiments, the photoresist is a metal oxo photoresist suitable for EUV patterning. However, it should be understood that the photoresist is any type of photoresist and the patterning may include any lithography regime. During the deposition of photoresist onto the wafer 601, an inert gas may be flowed along the fluid channels between the inner surface of the edge ring 620 and the insulating layer 615, the pedestal 630, and the outer surface of the wafer 601. Thus, deposition of photoresist along the edges or back of the wafer 601 is substantially eliminated. In one embodiment, the wafer temperature 601 may be maintained between about -40°C and about 200°C by the cooling channels 631 of the second portion of the pedestal 630B.

[0076] Referring here to Figure 7A, a cross-sectional view of the processing tool 700 according to a further embodiment is shown. It should be understood that the lift pin(s) described above in relation to Figure 2A may be implemented in the embodiments described later in relation to Figure 7A. As shown in Figure 7A, the column includes a base plate 710. The base plate 710 may be supported by pillars 714 extending outside the chamber. That is, in some embodiments, the base plate 710 and pillars 714 may be separate components rather than a single monolithic part as shown in Figure 4. The pillars 714 may have an electrical connection and a central channel for supplying fluids (e.g., cooling fluid and inert gas for purge flow).

[0077] In one embodiment, an insulating layer 715 is placed on a base plate 710, and a pedestal 730 (i.e., a first portion 730A and a second portion 730B) is placed on the insulating layer 715. In one embodiment, a coolant channel 731 is provided in the second portion 730B of the pedestal 730. A wafer 701 is placed on the pedestal 730.

[0078] In one embodiment, an edge ring 720 is provided around the base plate 710, insulating layer 715, pedestal 730, and wafer 701. The edge ring 720 can be connected to the base plate 713 by a fastening mechanism 713 such as bolts, pins, or screws. In one embodiment, a seal 717 prevents purge gas from escaping the column from the bottom of the gap between the base plate 710 and the edge ring 720.

[0079] In the illustrated embodiment, the pedestal 730 is in a first position. Thus, the shadow ring 735 is supported by the holder 771 and the chamber liner 770. When the pedestal 730 is displaced vertically, the edge ring 720 engages with the shadow ring 735, lifting and releasing the shadow ring 735 from the holder 771.

[0080] Referring now to Figure 7B, a cross-sectional view of the chamber 700 according to a further embodiment is shown. It should be understood that the lift pin(s) described above in relation to Figure 2A may be implemented in the embodiments described later in relation to Figure 7B. In the diagram of Figure 7B, the insulating layer 715 and pedestal 730 are omitted so that the structure of the base plate 710 is more clearly visible. As shown, the base plate 710 may include a plurality of channels 711 that provide a fluid path from the center of the base plate 710 to the edge of the base plate 710. In the illustrated embodiment, a plurality of first channels connect the center of the base plate 710 to a first ring channel, and a plurality of second channels connect the first ring channel to the outer edge of the base plate 710. In one embodiment, the first and second channels are offset from each other. Although a specific configuration of the channels 711 is shown in Figure 7B, it should be understood that any channel configuration may be used to deliver an inert gas from the center of the base plate 710 to the edge of the base plate 710.

[0081] Figure 8 shows a graphical representation of an exemplary form of a computer system 800 in which a set of instructions for a machine to perform any one or more of the methods described herein can be executed. In alternative embodiments, the machine may be connected to other machines (e.g., network-connected) in a local area network (LAN), intranet, extranet, or internet. The machine may operate in a client-server network environment by the capabilities of a server or client machine, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), tablet PC, set-top box (STB), portable information terminal (PDA), mobile phone, web device, server, network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or different) that specify the operation to be performed by the machine. Furthermore, although only a single machine is shown, the term “machine” shall also be interpreted to include any collection of machines (e.g., computers) that individually or collectively execute a set of instructions (or sets of instructions) for performing any one or more of the methods described herein.

[0082] An exemplary computer system 800 includes a processor 802, main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or rhombus DRAM (RDRAM), etc.), static memory 806 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and secondary memory 818 (e.g., data storage device), all communicating with each other via a bus 830.

[0083] Processor 802 represents one or more general-purpose processing devices, such as a microprocessor or a central processing unit. More specifically, processor 802 may be a composite instruction set arithmetic (CISC) microprocessor, a reduced instruction set arithmetic (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing another instruction set, or a processor implementing a combination of instruction sets. Processor 802 may also be one or more dedicated processing devices, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), or a network processor. Processor 802 is configured to execute processing logic 826 for performing the operations described herein.

[0084] The computer system 800 may further include a network interface device 808. The computer system 800 may also include a video display device 810 (e.g., a liquid crystal display (LCD), a light-emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generating device 816 (e.g., a speaker).

[0085] The secondary memory 818 may include a machine-accessible storage medium (or more specifically, a computer-readable storage medium) 832 storing one or more instruction sets (e.g., software 822) that embody any one or more of the methods or functions described herein. This software 822 may also reside, all or at least partially, in the main memory 804 and / or processor 802 while being executed by the computer system 800. The main memory 804 and processor 802 also constitute a machine-readable storage medium. The software 822 may further be transmitted or received over the network 820 via the network interface device 808.

[0086] In exemplary embodiments, the machine-accessible storage medium 832 is shown as a single medium, but the term “machine-readable storage medium” should be interpreted to include a single or multiple mediums that store one or more sets of instructions (e.g., a centralized or distributed database, and / or associated caches and servers). The term “machine-readable storage medium” should also be interpreted to include any medium that can store or encode a set of instructions executed by a machine, causing the machine to execute any one or more of the methodologies of this disclosure. Accordingly, the term “machine-readable storage medium” should be interpreted to include, but not limited to, solid memory, optical media, and magnetic media.

[0087] According to one embodiment of the present disclosure, a machine-accessible storage medium stores instructions causing a data processing system to perform a method of chucking a wafer using a lift pin assembly comprising a first metal spring, a first metal connected to the first metal spring above the first metal spring, a second metal connected to the first metal above the first metal, a second metal connected to the second metal spring above the second metal spring, and a ceramic connected to the second metal above the second metal.

[0088] Therefore, an apparatus for clamping a substrate onto a unipolar electrostatic chuck for photoresist film deposition is disclosed.

Claims

1. A lift pin assembly, The first metal spring, A first metal connected to the first metal spring above the first metal spring, A ceramic connected to the first metal above the first metal and A lift pin assembly, including the lift pin assembly.

2. The lift pin assembly according to claim 1, wherein the first metal spring provides a consistent grounding path to the lift pin assembly.

3. The lift pin assembly according to claim 1, wherein the first metal spring provides conformability to the lift pin assembly.

4. The lift pin assembly according to claim 1, wherein the first metal spring provides guided linear motion to the lift pin assembly.

5. The lift pin assembly according to claim 1, further comprising a second metal spring connected to the first metal above the first metal, and a second metal connected to the second metal spring above the second metal spring, wherein the ceramic is connected to the second metal above the second metal.

6. The lift pin assembly according to claim 5, wherein the second metal spring provides contact pressure to the lift pin assembly.

7. The lift pin assembly according to claim 1, wherein the ceramic is for supporting a wafer, and the ceramic includes SiC.

8. It is a unipolar electrostatic chuck, The zipper body and Multiple lift pin holes in the chuck body, A plurality of lift pins, wherein each of the plurality of lift pins is located in a corresponding lift pin hole among the plurality of lift pin holes. The plurality of lift pins are provided, First metal spring, A first metal connected to the first metal spring above the first metal spring, A second metal spring connected to the first metal above the first metal, A second metal connected to the second metal spring above the second metal spring, and A ceramic connected to the second metal above the second metal. A unipolar electrostatic chuck, including one.

9. The unipolar electrostatic chuck according to claim 8, wherein each of the first metal springs of the plurality of lift pins provides a consistent grounding path to the lift pin assembly.

10. The unipolar electrostatic chuck according to claim 8, wherein each of the plurality of lift pins has a first metal spring that provides conformability to the lift pin assembly.

11. The unipolar electrostatic chuck according to claim 8, wherein each of the first metal springs of the plurality of lift pins provides guided linear motion to the lift pin assembly.

12. The unipolar electrostatic chuck according to claim 8, wherein each of the second metal springs of the plurality of lift pins provides back pressure to the lift pin assembly.

13. The unipolar electrostatic chuck according to claim 8, wherein each of the second metal springs of the plurality of lift pins provides contact pressure to the lift pin assembly.

14. The monopolar electrostatic chuck according to claim 8, wherein each of the plurality of lift pins has a ceramic element for supporting a wafer, and the ceramic element includes SiC.

15. It is a system, Chamber and, A plasma source located within or connected to the chamber, The monopolar electrostatic chuck in the chamber and The unipolar electrostatic chuck is equipped with, Zipper body, Multiple lift pin holes in the chuck body, Multiple lift pins, wherein each of the multiple lift pins is located in a corresponding lift pin hole among the multiple lift pin holes. The plurality of lift pins are provided, First metal spring, A first metal connected to the first metal spring above the first metal spring, A second metal spring connected to the first metal above the first metal, A second metal connected to the second metal spring above the second metal spring, and A ceramic connected to the second metal above the second metal. A system that includes this.

16. The system according to claim 15, wherein each of the first metal springs of the plurality of lift pins of the unipolar electrostatic chuck provides a consistent grounding path to the lift pin assembly.

17. The system according to claim 15, wherein each of the first metal springs of the plurality of lift pins of the unipolar electrostatic chuck provides conformability to the lift pin assembly.

18. The system according to claim 15, wherein each of the first metal springs of the plurality of lift pins of the unipolar electrostatic chuck provides guided linear motion to the lift pin assembly.

19. The system according to claim 15, wherein each of the second metal springs of the plurality of lift pins of the unipolar electrostatic chuck provides back pressure to the lift pin assembly, and each of the second metal springs of the plurality of lift pins of the unipolar electrostatic chuck provides contact pressure to the lift pin assembly.

20. The system according to claim 15, wherein each of the plurality of lift pins of the monopolar electrostatic chuck is for supporting a wafer, and the ceramic includes SiC.

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