Reduced localized forces in electrostatic chucking

Abstract

To provide a semiconductor substrate support assembly and a method for semiconductor processing.SOLUTION: A substrate support 300 includes an electrostatic chuck body 305 having a substrate support surface 307. The electrostatic chuck body defines a plurality of protrusions 310 extending from the substrate support surface. The substrate support includes an electrode 315 embedded within the electrostatic chuck body. The electrode defines apertures 330 therethrough in line with the plurality of protrusions extending from the substrate support surface.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Non-Provisional Application No. 17 / 205,867, filed March 18, 2021, and entitled "REDUCED LOCALIZED FORCE IN ELECTROSTATIC CHUCKING," the contents of which are incorporated herein by reference in their entirety for all purposes.

[0002] The present technology relates to semiconductor systems, processes, and manufacturing equipment. More particularly, the present technology relates to processes and systems for securing substrates on support assemblies. [Background technology]

[0003] Many substrate processing systems use a substrate support, such as an electrostatic chuck, in combination with a base to hold a wafer during semiconductor substrate processing. An embedded electrode may electrostatically chuck the wafer or substrate to the substrate support. A voltage may be applied to the electrode, which provides a clamping force. However, this clamping force may cause backside damage to the substrate and may generate backside particles that may cause problems in subsequent processing.

[0004] Thus, there is a need for improved systems and methods that can be used to improve the life and performance of processing chambers and components. These and other needs are addressed by the present technology. Summary of the Invention

[0005] The semiconductor substrate support assembly may include an electrostatic chuck body having a substrate support surface. The electrostatic chuck body may define a plurality of protrusions extending from the substrate support surface. The assembly may include an electrode embedded within the electrostatic chuck body. The electrode may define apertures therethrough that align with the plurality of protrusions extending from the substrate support surface.

[0006] In some embodiments, the electrode may include a continuous electrode through the electrostatic chuck body and around the plurality of protrusions. The electrode may define an aperture aligned with each of the plurality of protrusions. Each aperture may be characterized by a diameter larger than the diameter of the corresponding protrusion with which it is aligned. Each aperture may extend along the substrate support surface with a diameter that is approximately 5% or more larger than the diameter of the corresponding protrusion. The assembly may include a seal band defined around the exterior of the electrostatic chuck body. The assembly may include a gas delivery channel formed through the electrostatic chuck body. The gas delivery channel may be configured to deliver backside gas to a space defined between the plurality of protrusions and the seal band. The gas delivery channel may be fluidly coupled to a fluid source. The fluid source may be or include helium gas. The assembly may include a power supply coupled to the electrode embedded within the electrostatic chuck body. The power supply may be configured to provide a chucking voltage to the electrode.

[0007] Some embodiments of the present technology may include a substrate support assembly. The assembly may include an electrostatic chuck body. The electrostatic chuck body may define a plurality of protrusions along a substrate support surface of the electrostatic chuck body. The assembly may include an electrode embedded within the electrostatic chuck body. The electrode may define a plurality of apertures therethrough. Each aperture of the plurality of apertures may be formed along the substrate support surface to be vertically aligned with one of the plurality of protrusions.

[0008] In some embodiments, the electrode may include a continuous electrode through the electrostatic chuck body and around the plurality of protrusions. Each protrusion may be characterized by a diameter of about 1 mm or more. Each aperture may be characterized by a diameter larger than the diameter of the corresponding protrusion with which it is aligned. Each aperture may extend along the substrate support surface at a diameter greater than the diameter of the corresponding protrusion by about 3% or more. The assembly may include a seal band defined around the exterior of the electrostatic chuck body. The assembly may include a gas delivery channel formed through the electrostatic chuck body. The gas delivery channel may be configured to deliver backside gas to a space defined between the plurality of protrusions and the seal band. The gas delivery channel may be fluidly coupled to a fluid source. The fluid source may be or include helium gas. The assembly may include a power supply coupled to the electrode embedded within the electrostatic chuck body. The power supply may be configured to provide a chucking voltage to the electrode.

[0009] Some embodiments of the present technology may include a method of semiconductor processing. The method may include providing a voltage to an electrode embedded in an electrostatic chuck body. The electrostatic chuck body may define a plurality of protrusions along a substrate support surface of the electrostatic chuck body. The electrode may define a plurality of apertures therethrough. Each aperture of the plurality of apertures may be formed along the substrate support surface to be vertically aligned with one of the plurality of protrusions. The method may include clamping a substrate to the electrostatic chuck body. In some embodiments, the voltage may be about 1000 V or greater. A chucking force at each of the plurality of protrusions may be about 98% or less of a chucking force between each of the plurality of protrusions.

[0010] Such technology may provide numerous benefits over conventional systems and techniques. For example, the process may reduce localized chucking force at locations across the substrate support, while still producing a sufficient global chucking force. Additionally, the process may reduce or limit backside particles, which may aid in downstream processing. These and other embodiments, along with many of the advantages and features of those embodiments, are described in more detail below in connection with the description and accompanying figures.

[0011] A further understanding of the nature and advantages of the disclosed technology may be realized by reference to the remaining portions of the specification and drawings. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 shows a schematic top view of an exemplary processing system in accordance with some embodiments of the present technology. [Figure 2] FIG. 1 shows a schematic cross-sectional view of an exemplary processing system in accordance with some embodiments of the present technology. [Figure 3A] 1A and 1B show schematic partial cross-sectional views of an exemplary substrate support in accordance with some embodiments of the present technology. [Figure 3B] 1 shows a schematic top view of an exemplary substrate support in accordance with some embodiments of the present technology. [Figure 4] 1A-1D illustrate selected operations in a method of semiconductor processing in accordance with some embodiments of the present technology. DETAILED DESCRIPTION OF THE INVENTION

[0013] Some of the figures are included as schematics. It should be understood that the figures are for illustrative purposes and should not be considered to be to scale unless expressly stated to be to scale. Additionally, as schematics, the figures are provided to aid in comprehension and may not include all aspects or information compared to realistic representations and may include exaggerated subject matter for illustrative purposes.

[0014] In the accompanying figures, similar components and / or features may have the same reference label. Furthermore, various components of the same type may be distinguished by following the reference label with a letter that distinguishes among the similar components. If only a first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label, regardless of the letter.

[0015] Plasma etching processes may impart energy to one or more constituent precursors to aid in material removal from a substrate. Process conditions may cause the substrate to be expelled or displaced if not properly clamped. In addition, films formed on the substrate may induce stress on the substrate. For example, as processing may involve more films to create complex structures, thicker layers of material may develop on the substrate. These formed films may be characterized by inward stress acting on the substrate. This inward stress may cause the substrate to bow during processing, which, if uncontrolled, can lead to poor removal uniformity as well as device damage or malfunction.

[0016] Electrostatic chucks are sometimes used to create a clamping action on a substrate to overcome bowing stress and hold the substrate during the etching process. However, as the thickness and complexity of these device structures increase, the stress exerted on the substrate increases, which may require a proportional increase in chucking voltage. In addition, many etching processes may be performed at relatively high temperatures, which further impacts chamber components. For example, some etching activities may occur at temperatures of several hundred degrees or more, which may cause the substrate to thermally expand radially outward. This expansion in combination with increased chucking voltage may not only cause particles to be expelled from the underlying chuck body, but may also cause scratches to form on the backside of the semiconductor substrate in contact with the substrate support.

[0017] These scratches and particles can cause several challenges. For example, when a substrate is removed from processing and replaced with another processed substrate in a front-opening unified pod, particles generated from the contacts can fall onto the underlying substrate, which can act as defects in the film produced on the underlying substrate. In addition, some subsequent processing can be affected by the damage. For example, the subsequent operation can include lithography. Backside damage can cause displacement of projected beams throughout the substrate, which can affect the lithography process, or particles can impact sensitive lithography bases. These issues have limited previous technologies, causing wafer loss due to damage to lithography components as well as impacts on subsequent processing. The present technology overcomes these challenges by incorporating electrodes into the substrate support, which can reduce electrostatic forces at the location of contact with the substrate. This can limit substrate backside damage, especially at elevated temperatures.

[0018] While the remainder of this disclosure will routinely highlight specific etching and cleaning processes utilizing the disclosed technology, it will be readily understood that the systems and methods are equally applicable to a variety of other processes, such as those that may occur in the described chambers. Thus, the technology should not be considered limited for use solely with the described etching or cleaning processes. This disclosure will discuss one possible system and chamber that may be used with the technology before describing the systems and methods or operation of an exemplary process sequence according to some embodiments of the technology. It should be understood that the technology is not limited to the described manufacturing apparatus, and the discussed processes may be performed in any number of processing chambers and systems.

[0019] 1 shows a top diagrammatic view of one embodiment of a deposition, etch, bake, and / or cure chamber processing system 10, according to embodiments. The tool or processing system 10 depicted in FIG. 1 may contain multiple process chambers 24a-d, a transfer chamber 20, a service chamber 26, an integrated metrology chamber 28, and a pair of load lock chambers 16a-b. The process chambers may include any number or combination of processing chambers, as well as any number of structures or components.

[0020] To transport substrates between chambers, the transfer chamber 20 may contain a robotic transport mechanism 22. The transport mechanism 22 may have a pair of substrate transport blades 22a attached to the distal end of each of extendable arms 22b. The blades 22a may be used to transport individual substrates to and from the process chambers. In operation, one of the substrate transport blades, such as blade 22a of the transport mechanism 22, may remove a substrate W from one of the load lock chambers, such as chambers 16a-b, and transport the substrate W to chambers 24a-d for processing, e.g., the first stage of a treatment process, as described below. The chambers may be included to perform individual or combined operations of the described technology. For example, one or more chambers may be configured to perform deposition or etching operations, while one or more other chambers may be configured to perform pre-treatment operations and / or one or more post-treatment operations, as described. Any number of configurations, which may further perform any number of additional fabrication operations typically performed in semiconductor processing, are encompassed by the present technology.

[0021] If a chamber is occupied, the robot may wait until processing is complete and then remove the processed substrate from the chamber with one blade 22a and insert a new substrate with a second blade. Once the substrate has been processed, it may then be moved to a second stage of processing. For each movement, the transport mechanism 22 may generally have one blade carrying the substrate and one blade free to perform a substrate swap. The transport mechanism 22 may wait in each chamber until the swap can be accomplished.

[0022] Once processing is completed in the process chamber, the transport mechanism 22 may move the substrate W from the last process chamber and transport the substrate W to a cassette in the load lock chambers 16a-b. From the load lock chambers 16a-b, the substrate may move into the factory interface 12. The factory interface 12 may generally operate to transfer substrates between the pod loaders 14a-d and the load lock chambers 16a-b in an atmospheric pressure clean environment. The clean environment within the factory interface 12 may generally be provided by an air filtration process, such as HEPA filtration. The factory interface 12 may also include a substrate orienter / aligner that may be used to properly align the substrates prior to processing. At least one substrate robot, such as robots 18a-b, may be positioned within the factory interface 12 to transport substrates between various locations within the factory interface 12 and to other locations in communication with the factory interface 12. The robots 18a-b may be configured to travel along a track system within the factory interface 12 from a first end to a second end of the factory interface 12.

[0023] The processing system 10 may further include an integrated metrology chamber 28 for providing control signals that may provide adaptive control over any of the processes being performed in the processing chambers. The integrated metrology chamber 28 may include any of a variety of metrology devices for measuring various film characteristics such as thickness, roughness, composition, etc., and may further be capable of characterizing lattice parameters such as critical dimensions, sidewall angles, and feature heights under vacuum in an automated manner.

[0024] Each of the processing chambers 24a-d may be configured to perform one or more process steps in the fabrication of semiconductor structures, and any number and combination of processing chambers may be used on the multichamber processing system 10. For example, any of the processing chambers may be configured to perform a number of substrate processing operations, including any number of deposition processes, including cyclical layer deposition, atomic layer deposition, chemical vapor deposition, and physical vapor deposition, as well as other operations, including etching, pre-cleaning, pre-treatment, post-treatment, annealing, plasma treatment, degassing, orientation, and other substrate processes. Some specific processes that may be performed in any of the chambers, or in any combination of chambers, may be metal deposition, surface cleaning and preparation, thermal annealing, such as rapid thermal processing, and plasma treatment. Any other processes, including any of the processes described below, may likewise be performed in the specific chambers incorporated into the multichamber processing system 10, as will be readily apparent to a skilled artisan.

[0025] 2 illustrates a schematic cross-sectional view of an exemplary processing chamber 100 suitable for patterning a material layer disposed on a substrate 302 within the processing chamber 100. While the exemplary processing chamber 100 is suitable for performing a patterning process, it should be understood that aspects of the present technology may be performed in any number of chambers, and that a substrate support according to the present technology may be included in an etch chamber, a deposition chamber, a treatment chamber, or any other processing chamber. The plasma processing chamber 100 may include a chamber body 105 defining a chamber space 101 in which a substrate may be processed. The chamber body 105 may have sidewalls 112 and a bottom 118 coupled to ground 126. The sidewalls 112 may have a liner 115 to protect the sidewalls 112 and extend the time between maintenance cycles of the plasma processing chamber 100. The dimensions of the chamber body 105 and associated components of the plasma processing chamber 100 are not limited and may generally be proportionally larger than the size of the substrate 302 to be processed in the plasma processing chamber 100. Example substrate sizes, such as display substrates or even solar cell substrates, include 200 mm diameter, 250 mm diameter, 300 mm diameter, and 450 mm diameter, among others.

[0026] The chamber body 105 may support a chamber lid assembly 110 for enclosing the chamber volume 101. The chamber body 105 may be fabricated from aluminum or other suitable materials. A substrate access port 113 may be formed through a sidewall 112 of the chamber body 105 to facilitate transfer of a substrate 302 into and out of the plasma processing chamber 100. The access port 113 may be coupled to a transfer chamber and / or other chambers of a substrate processing system as previously described. A pumping port 145 may be formed through the sidewall 112 of the chamber body 105 and connected to the chamber volume 101. A pumping device may be coupled to the chamber volume 101 through the pumping port 145 to evacuate the processing space and control the pressure therein. The pumping device may include one or more pumps and a throttle valve.

[0027] A gas panel 160 may be coupled to the chamber body 105 by gas lines 167 to supply process gases into the chamber volume 101. The gas panel 160 may include one or more process gas sources 161, 162, 163, 164, and may additionally include inert, non-reactive, and reactive gases that may be utilized for any number of processes. Examples of process gases that may be provided by the gas panel 160 include, but are not limited to, hydrocarbon-containing gases including methane, sulfur hexafluoride, silicon chloride, carbon tetrafluoride, hydrogen bromide, hydrocarbon-containing gases, argon gas, chlorine, nitrogen, helium, or oxygen gas, as well as any number of additional materials. Additionally, the process gas may include nitrogen-, chlorine-, fluorine-, oxygen-, and hydrogen-containing gases such as BCl, C2F4, C4F8, C4F6, CHF3, CH2F2, CH3F, NF3, NH3, CO2, SO2, CO, N2, NO2, N2O, and H2, among any number of additional precursors.

[0028] A valve 166 may control the flow of process gas from sources 161, 162, 163, and 164 from the gas panel 160 and may be managed by a controller 165. The flow of gas supplied from the gas panel 160 to the chamber body 105 may include a combination of gas types, one or more sources. The lid assembly 110 may include a nozzle 114. The nozzle 114 may be one or more ports for introducing process gas from the sources 161, 162, 164, and 163 of the gas panel 160 into the chamber volume 101. After the process gas is introduced into the plasma processing chamber 100, the gas may be energized to form a plasma. An antenna 148, such as one or more inductor coils, may be provided near the plasma processing chamber 100. An antenna power supply 142 may power the antenna 148 through a match circuit 141 to inductively couple energy, such as RF energy, to the process gas to maintain a plasma formed from the process gas within the chamber volume 101 of the plasma processing chamber 100. Alternatively, or in addition to the antenna power supply 142, a process electrode below and / or above the substrate 302 may be used to capacitively couple RF power to the process gas to maintain a plasma within the chamber volume 101. The operation of the power supply 142 may be controlled by a controller, such as controller 165, which in turn controls the operation of other components in the plasma processing chamber 100.

[0029] A substrate support pedestal 135 may be disposed within the chamber volume 101 to support the substrate 302 during processing. The substrate support pedestal 135 may include an electrostatic chuck 122 for securing the substrate 302 during processing. The electrostatic chuck (“ESC”) 122 may use electrostatic attraction to secure the substrate 302 to the substrate support pedestal 135. The ESC 122 may be powered by an RF power supply 125 integrated with a match circuit 124. The ESC 122 may include an electrode 121 embedded within a dielectric body. The electrode 121 may be coupled to the RF power supply 125 and may provide a bias to the ESC 122 and the substrate 302 mounted on the pedestal that attracts plasma ions formed by the process gas within the chamber volume 101. The RF power supply 125 may be cycled on and off, or pulsed, during processing of the substrate 302. The ESC 122 may have an isolator 128 for the purpose of making the sidewalls of the ESC 122 less attractive to the plasma in order to extend the maintenance lifecycle of the ESC 122. Additionally, the substrate support pedestal 135 may have a cathode liner 136 to protect the sidewalls of the substrate support pedestal 135 from plasma gases and to extend the time between maintenance of the plasma processing chamber 100.

[0030] The electrode 121 may be coupled to a power supply 150. The power supply 150 may provide a chucking voltage of about 200 volts to about 2000 volts to the electrode 121. The power supply 150 may further include a system controller for controlling the operation of the electrode 121 by directing DC current to the electrode 121 to chuck and dechuck the substrate 302. The ESC 122 may include a heater disposed in the pedestal and connected to a power supply to heat the substrate, while the cooling base 129 supporting the ESC 122 may include conduits for circulating a heat transfer fluid to maintain the temperature of the ESC 122 and the substrate 302 disposed thereon. The ESC 122 may be configured to operate within a temperature range required by the thermal budget of the device being fabricated on the substrate 302. For example, the ESC 122 may be configured to maintain the substrate 302 at a temperature of about −150° C. or lower to about 500° C. or higher, depending on the process being performed.

[0031] A cooling base 129 may be provided to help control the temperature of the substrate 302. To reduce process drift and time, the temperature of the substrate 302 may be kept substantially constant by the cooling base 129 throughout the time the substrate 302 is in the cleaning chamber. In some embodiments, the temperature of the substrate 302 may be maintained at a temperature between about −150° C. and about 500° C. throughout the subsequent cleaning process, although any temperature may be utilized. A cover ring 130 may be disposed over the ESC 122 and along the periphery of the substrate support pedestal 135. The cover ring 130 may be configured to confine the etching gas to a desired portion of the exposed top surface of the substrate 302, while protecting the top surface of the substrate support pedestal 135 from the plasma environment inside the plasma processing chamber 100. The lift pins may be selectively translated through the substrate support pedestal 135 to lift the substrate 302 above the substrate support pedestal 135 to facilitate access to the substrate 302 by a transfer robot or other suitable transfer mechanism, as previously described.

[0032] The controller 165 may be utilized to modulate gas flow from the gas panel 160 into the plasma processing chamber 100 and other process parameters to control the process sequence. The software routines, when executed by the CPU, transform the CPU into a special-purpose computer, such as a controller, that may control the plasma processing chamber 100 so that processes are performed according to the present disclosure. The software routines may also be stored and / or executed by a second controller that may be associated with the plasma processing chamber 100.

[0033] 3A shows a schematic partial cross-sectional view of an exemplary substrate support 300 according to some embodiments of the present technology. For example, the substrate support 300 may illustrate a portion of the support pedestal 135 described above and may include any aspect of that support assembly, including electrodes, heaters, or any other components that may be incorporated within the substrate support. The substrate support 300 may also illustrate additional details of the support assembly described above. The substrate support 300 may illustrate a generalized cross-section of a support structure according to embodiments of the present technology, which may extend at any length or diameter across a substrate encompassed by the present technology. It should be understood that the substrate support 300 is not illustrated to any particular scale and is included solely to illustrate aspects of the present technology.

[0034] The substrate support 300 may include any number of components bonded, welded, joined, or otherwise coupled to one another. While any number of additional components may be included as illustrated, the substrate support 300 may include an electrostatic chuck body 305 or upper puck, which may be coupled to a power source to provide electrostatic chucking or clamping of a substrate on the surface of the puck. Components incorporated into the upper puck may, in some embodiments, not be exposed to process materials and may be retained entirely within the chuck body. The electrostatic chuck body 305 may define a substrate support surface 307 and may be characterized by a thickness and length or diameter, depending on the particular geometry of the chuck body. In some embodiments, the chuck body may be elliptical and characterized by one or more radial dimensions from a central axis through the chuck body. It should be understood that the upper puck can be of any shape and size, and when radial dimensions are discussed, those dimensions can define any length from the center location of the chuck body. While any surface topography can be encompassed by the present technology, in some embodiments, the electrostatic chuck body 305 can define a number of mesas or protrusions 310 upon which a substrate 312 can be mounted. Between the protruding portions of the puck, there can be recessed regions, as illustrated.

[0035] The electrostatic chuck body 305 may include an electrode 315, which may be a DC electrode, embedded within the chuck body proximate the substrate support surface. The electrode 315 may be electrically coupled to a power supply 320. The power supply 320 may be configured to provide energy or voltage to the electrically conductive chuck electrode 315. The chuck electrode 315 may be operated to form a plasma of a precursor in a processing region of a semiconductor processing chamber in which the substrate support assembly is disposed, although other plasma operations may be maintained as well. For example, the electrode 315 may also be a chuck electrode that also serves as an electrical ground for a capacitive plasma system that includes an RF source electrically coupled to a showerhead or other chamber component. For example, the electrode 315 may serve as a ground path for RF power from an RF source coupled elsewhere in the chamber, while also serving as an electrical bias for the substrate to effect electrostatic clamping of the substrate to the substrate support surface. The power supply 320 may include a filter, a power supply, and any number of other electrical components configured to provide the chucking voltage.

[0036] In operation, the substrate 312 may be in at least partial contact with the substrate support surface of the electrostatic chuck body, which may create a contact gap, essentially creating a capacitive effect between the surface of the pedestal and the substrate. A voltage may be applied to the contact gap, which may generate an electrostatic force for chucking. The power supply 320 may provide electric charges that migrate from the electrode to the substrate support surface, where they may accumulate, creating a charge layer with Coulomb attraction with opposite charges on the substrate, which may electrostatically clamp the substrate against the substrate support surface of the chuck body. This charge transfer may occur due to current flowing through the dielectric material of the chuck body, based on the finite resistance in the dielectric for Johnsen-Rahbek-type chucking, which may be used in some embodiments of the present technology.

[0037] In some embodiments, the electrostatic chuck body 305 may be an insulating or dielectric material. For example, oxides, nitrides, carbides, and other materials may be used to form the components. Exemplary materials may include ceramics, including aluminum oxide, aluminum nitride, silicon carbide, tungsten carbide, and any other metallic or transition metal oxide, nitride, carbide, boride, or titanate, as well as combinations of these and other insulating or dielectric materials. Different grades of ceramic material may be used to provide composites configured to operate in distinct temperature ranges, and thus, different ceramic grades of the same material may be used for the upper puck and stem in some embodiments. Dopants may be incorporated in some embodiments to adjust electrical properties, as will be further described below. Exemplary dopant materials may include yttrium, magnesium, silicon, iron, calcium, chromium, sodium, nickel, copper, zinc, or any number of other elements known to be incorporated into ceramic or dielectric materials.

[0038] During semiconductor processing, one or more backside gases may be flowed into the substrate support 300, such as through one or more gas delivery channels 330 extending through the stem of the substrate support. For example, a gas delivery system 335, which may include any number of valves, controllers, and / or piping, may provide one or more gases that may be flowed in and around gaps in the substrate support. Improved heat transfer within the substrate support may be maintained by providing a positive pressure of a fluid, such as an inert or non-reactive gas, within the substrate support. Any number of materials may be used as the heat transfer backside gas; in some embodiments, helium, nitrogen, argon, other noble gases, or other process gases may be utilized. Helium may be characterized by improved heat transfer relative to other precursors due to the fluid's relatively low molecular weight. For example, thermal conductivity may increase as molecular weight decreases, and thus helium, when flowed within the gaps of an apparatus, may aid in improved temperature uniformity throughout the structure. In some embodiments, helium may be supplemented with one or more other precursors, which may adjust the thermal conductivity of the backside gas. By providing nitrogen, argon, or other materials, the heat transfer properties of the fluid may be tailored for individual processes.

[0039] During substrate processing, the flow rate and / or pressure of the delivered backside gas may be kept relatively low and may be delivered at a rate to maintain a predetermined amount of pressure to improve thermal conductivity and maintain a minimal amount of leakage through the substrate support into the processing region. As a result, in some embodiments, the flow rate may be kept at about 20 sccm or less, about 15 sccm or less, about 12 sccm or less, about 10 sccm or less, about 9 sccm or less, about 8 sccm or less, about 7 sccm or less, about 6 sccm or less, about 5 sccm or less, about 4 sccm or less, about 3 sccm or less, about 2 sccm or less, about 1 sccm or less, or even lower, although the flow rate may be kept such that the controller of the gas delivery system 335 may be operated above a threshold.

[0040] As previously discussed, the substrate 312 may be positioned on the substrate support surface 307 and may contact each of the protrusions 310. Additionally, the substrate 312 may extend, at least in part, over a sealing band 325 that may extend around an outer region of the chuck body, which may enable a predetermined degree of sealing between the protrusions 310 and the substrate and the space defined around the protrusions 310 and the substrate. The sealing band 325 may extend perpendicularly from the surface of the chuck body and may extend in a generally circumferential or peripheral pattern around the chuck body. In some embodiments, the protrusions 310 may be characterized by a diameter or width of about 1 mm, about 2 mm, about 3 mm, or larger, and in some embodiments, may include a combination of protrusions characterized by a diameter of about 1 mm or greater and protrusions characterized by a diameter of about 2 mm or greater. The protrusions may be characterized by any number of geometries and profiles in embodiments of the present technology. For an exemplary substrate support assembly, the substrate support surface within the seal band or within the interior region may define about 250 or more protrusions, and may define about 500 or more, about 750 or more, about 1,000 or more, about 1,250 or more, about 1,500 or more, about 1,750 or more, about 2,000 or more protrusions. The protrusions may be defined in any number of formations or patterns, including uniform patterns as well as a general distribution across the surface.

[0041] By creating protrusions according to some embodiments of the present technology, the percentage of contact along the surface of the substrate can be increased to greater than or about 1.0%, and can be about 1.5% or more, about 2.0% or more, about 2.5% or more, about 3.0% or more, about 3.5% or more, about 4.0% or more, about 4.5% or more, about 5.0% or more, or more. The percentage of contact can be kept to about 10% or less to limit leakage current below the ranges stated above, and contact can be limited to about 8% or less, about 6% or less, about 5% or less, or less. Additionally, the protrusions themselves can be adjusted to affect the force generated on the substrate.

[0042] The power supply 320 may provide a voltage for clamping the substrate 312 and may be configured to provide a voltage of about 200 V or more, about 400 V or more, about 600 V or more, about 800 V or more, about 1000 V or more, about 1200 V or more, about 1400 V or more, about 1600 V or more, about 1800 V or more, about 2000 V or more, or higher. As discussed above, these high voltages may increase wear between the substrate and the protrusions on which the substrate rests. However, by reducing the voltage, the clamping force may be insufficient to overcome bowing of the substrate and may even allow a certain amount of backside gas leakage through the seal band. In some embodiments, the protrusions 310 may be characterized by rounded corners to limit backside damage to the substrate, but increased particle generation may still occur. Therefore, the present technology may utilize electrodes configured to reduce the local chucking voltage at the contact point between the chuck body and the substrate.

[0043] The electrode 315 may be characterized by a continuous conductive body extending through the chuck body. However, in some embodiments, the electrode 315 may define one or more apertures, including a plurality of apertures through the electrode, which may be created to align with a plurality of protrusions 310 extending from the substrate support surface. Thus, the electrode 315 may still extend continuously through the electrostatic chuck body, but may extend around some or all of the plurality of protrusions, including, as illustrated, embodiments in which apertures are defined through the electrode to align vertically with each protrusion of the plurality of protrusions. Additionally, in some embodiments, and unlike mesh electrodes, the apertures through the electrode may be limited to locations that align with the protrusions.

[0044] FIG. 3B shows a schematic top view of an exemplary substrate support 300 in accordance with some embodiments of the present technology, and may illustrate additional details of the apertures defined by the electrodes. While the electrodes 315 may be visible in the figure, it should be understood that this is for illustrative purposes only, and that in included embodiments, the electrodes may be fully embedded within the chuck body and may not be visible within the component. As illustrated, the electrostatic chuck body 305 may include a seal band 325 extending around the substrate support surface, upon which the substrate may be mounted as discussed above. The seal band 325 may define an interior region within which a plurality of protrusions 310 may be defined. It should be understood that FIG. 3B is shown merely to illustrate aspects of the present technology that may include hundreds or thousands of protrusions across the surface of the substrate support.

[0045] The electrode 315 may be a continuous conductive body that extends across the substrate support and may extend around the protrusions 310. The electrode 315 may extend up to or beyond the inner radial edge of the seal band 325, although in some illustrated embodiments, the outer diameter of the electrode 315 may be less than the inner diameter of the seal band 325. Similarly, the apertures 340, each of which may be formed to align with a corresponding protrusion 310, may be characterized by a diameter greater than the diameter of the corresponding protrusion 310 around which the aperture extends. By limiting the electrode overlap wherever contact with the substrate may occur, localized chucking forces may be reduced at the contact points, while maintaining a global chucking force across the substrate. Thus, increased chucking voltages may be applied in some embodiments, while scratching and particle generation may be reduced or limited.

[0046] The difference between the diameter of the protrusion and the corresponding aperture through the electrode can be about 0.10 mm or more, about 0.15 mm or more, about 0.20 mm or more, about 0.25 mm or more, about 0.30 mm or more, about 0.35 mm or more, about 0.40 mm or more, about 0.45 mm or more, about 0.50 mm or more, about 0.55 mm or more, about 0.60 mm or more, about 0.65 mm or more, about 0.70 mm or more, about 0.75 mm or more, about 0.80 mm or more, about 0.85 mm or more, about 0.90 mm or more, about 0.95 mm or more, about 1.00 mm or more, or more, although as the aperture size continues to increase, the clamping force may be reduced at the contact location. As a result, in some embodiments, the difference between the diameter of the protrusion and the corresponding aperture through the electrode can be about 1.0 mm or less, or less. Similarly, depending on the protrusion size, the corresponding aperture may extend along the substrate support surface at a diameter greater than or equal to about 1% larger than the diameter of the corresponding protrusion, and may extend at a diameter greater than or equal to about 1%, greater than or equal to about 2%, greater than or equal to about 3%, greater than or equal to about 4%, greater than or equal to about 5%, greater than or equal to about 6%, greater than or equal to about 7%, greater than or equal to about 8%, greater than or equal to about 9%, greater than or equal to about 10%, greater than or equal to about 15%, greater than or equal to about 20%, greater than or equal to about 25%, greater than or equal to about 30%, greater than or equal to about 35%, greater than or equal to about 40%, greater than or equal to about 45%, greater than or equal to about 50% or greater.

[0047] Additionally, the gap between any two protrusions can be characterized by a first length, and the length of the electrode in the gap can be characterized by a second length that is less than the first. In some embodiments, the second length can be about 99% or less of the first length, such as about 95% or less, about 90% or less, about 85% or less, about 80% or less, about 75% or less, about 70% or less, about 65% or less, about 60% or less, about 55% or less, about 50% or less, or less. This can help reduce clamping forces on the edges of the protrusions during operation. To maintain separation between the electrode and the protrusions in the vertically separated plane, the electrode may be deposited by physical vapor deposition, screen printing, chemical vapor deposition, or any other process that may allow a pattern to be formed, which pattern correlates with the pattern of the protrusions on the substrate support.

[0048] The substrate supports described above may be used in methods according to embodiments of the present technology. FIG. 4 illustrates a method 400 for processing a semiconductor substrate, the operations of which may be performed in one or more chambers 100 incorporated on a multi-chamber processing system 10, for example, as described above. Any other chamber that may perform one or more operations of any described method or process may also be utilized. In addition, the method may be performed by a chamber or system including a substrate support that may be or include any aspect of the substrate support 300 described above. The method 400 may include one or more operations prior to the initiation of the stated method operations, including front-end processing, deposition, etching, polishing, cleaning, or any other operation that may be performed prior to the described operations. The method may include any number of optional operations, as indicated in the figure, that may or may not be specifically associated with a method according to the present technology. For example, many of the operations are described to provide a broader scope of semiconductor processing, but are not essential to the technology or may be performed by alternative methodologies as will be discussed further below.

[0049] During processing operations of method 400, a substrate may be positioned on a substrate support, such as the substrate support 300 described above, in optional operation 405. A voltage may be applied to the electrode as previously discussed, which may electrostatically clamp the substrate to the electrostatic chuck body in operation 410, clamping the substrate along the protrusions and / or seal bands as previously described. Depending on the voltage applied, the clamping force at any particular location along the substrate may be about 50 N or more, about 100 N or more, about 150 N or more, about 200 N or more, about 250 N or more, about 300 N or more, about 350 N or more, about 400 N or more, about 450 N or more, about 500 N or more, about 550 N or more, about 600 N or more, about 650 N or more, about 700 N or more, or more. As previously described, by creating apertures in the electrode around each substrate support contact location, the localized chucking force at each protrusion can be about 99% or less of the global chucking force exerted by the electrode, about 98% or less of the chucking force, about 97% or less of the chucking force, about 96% or less of the chucking force, about 95% or less of the chucking force, about 94% or less of the chucking force, about 93% or less of the chucking force, about 92% or less of the chucking force, about 91% or less of the chucking force, about 90% or less of the chucking force, about 85% or less of the chucking force, about 80% or less of the chucking force, or less. By utilizing electrodes with specifically located apertures as described, the present technology can limit scratches and particle transport on the backside of the substrate.

[0050] In the preceding description, for purposes of explanation, numerous details are set forth in order to provide an understanding of various embodiments of the present technology. However, it will be apparent to one skilled in the art that certain embodiments may be practiced without some of these details or with additional details.

[0051] Although several embodiments have been disclosed, it will be recognized by those skilled in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. Additionally, a number of well-known processes and elements have not been described to avoid unnecessarily obscuring the technology. Therefore, the above description should not be construed as limiting the scope of the technology.

[0052] When a range of values ​​is provided, it is understood that each intervening value between the upper and lower limits of that range, to the smallest fraction of the unit of the lower limit, unless the context clearly dictates otherwise, is also specifically disclosed. Any narrower range between any stated or unstated intervening value in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of those smaller ranges may independently be included or excluded in the range, and each range where either limit is included, neither limit is included, or both limits are included in the smaller range is also encompassed within the technology, subject to any specifically excluded limit in the stated range. When a stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.

[0053] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a layer" includes a plurality of such layers, reference to "the protrusion" includes reference to one or more protrusions and equivalents of those protrusions known to those skilled in the art, and so forth.

[0054] Furthermore, the words "comprise (present tense)," "comprise (present participle)," "include / contain (present tense)," "include / contain (present participle)," "include (present tense)," and "comprise (present participle)," when used in this specification and in the claims that follow, are intended to specify the presence of stated features, integers, components, or operations, but these words do not exclude the presence or addition of one or more other features, integers, components, operations, acts, or groups.

Claims

1. an electrostatic chuck body having a substrate support surface, the electrostatic chuck body defining a plurality of protrusions extending from the substrate support surface; an electrode embedded within the electrostatic chuck body, the electrode defining apertures therethrough that align with the plurality of protrusions extending from the substrate support surface; A substrate support assembly comprising:

2. The substrate support assembly of claim 1 , wherein the electrode comprises a continuous electrode through the electrostatic chuck body and around the plurality of protrusions.

3. The substrate support assembly of claim 1 , wherein the electrode defines an aperture aligned with each protrusion of the plurality of protrusions.

4. The substrate support assembly of claim 3 , wherein each aperture is characterized by a diameter that is greater than a diameter of a corresponding protrusion that aligns with said aperture.

5. The substrate support assembly of claim 4 , wherein each aperture extends along the substrate support surface with a diameter that is at least about 5% larger than the diameter of the corresponding protrusion.

6. a seal band defined around the exterior of the electrostatic chuck body; The substrate support assembly of claim 1 , further comprising:

7. a gas delivery channel formed through the electrostatic chuck body configured to deliver a backside gas to a space defined between the plurality of protrusions and the seal band; The substrate support assembly of claim 6 , further comprising:

8. The substrate support assembly of claim 7 , wherein the gas delivery channel is fluidly coupled to a fluid source, the fluid source comprising helium gas.

9. a power supply coupled to the electrode embedded within the electrostatic chuck body and configured to provide a chucking voltage to the electrode; The substrate support assembly of claim 1 , further comprising:

10. an electrostatic chuck body defining a plurality of protrusions along a substrate support surface of the electrostatic chuck body; an electrode embedded within the electrostatic chuck body, the electrode defining a plurality of apertures therethrough, each aperture of the plurality of apertures formed to be vertically aligned with one of the plurality of protrusions along the substrate support surface; A substrate support assembly comprising:

11. The substrate support assembly of claim 10 , wherein the electrode comprises a continuous electrode through the electrostatic chuck body and around the plurality of protrusions.

12. The substrate support assembly of claim 10 , wherein each protrusion is characterized by a diameter of about 1 mm or greater.

13. The substrate support assembly of claim 12 , wherein each aperture is characterized by a diameter that is greater than a diameter of a corresponding protrusion that aligns with the aperture.

14. The substrate support assembly of claim 13 , wherein each aperture extends along the substrate support surface with a diameter that is at least about 3% larger than the diameter of the corresponding protrusion.

15. a seal band defined around the exterior of the electrostatic chuck body; The substrate support assembly of claim 10 further comprising:

16. a gas delivery channel formed through the electrostatic chuck body, the gas delivery channel configured to deliver a backside gas to a space defined between the plurality of protrusions and the seal band, the gas delivery channel fluidly coupled to a fluid source, the fluid source comprising helium gas. The substrate support assembly of claim 15 further comprising:

17. a power supply coupled to the electrode embedded within the electrostatic chuck body and configured to provide a chucking voltage to the electrode; The substrate support assembly of claim 10 further comprising:

18. providing a voltage to an electrode embedded within an electrostatic chuck body, the electrostatic chuck body defining a plurality of protrusions along a substrate support surface of the electrostatic chuck body, the electrode defining a plurality of apertures therethrough, each aperture of the plurality of apertures formed along the substrate support surface in vertical alignment with one of the plurality of protrusions; clamping a substrate to the electrostatic chuck body; A method of semiconductor processing comprising:

19. 20. The method of semiconductor processing of claim 18, wherein the voltage is about 1000V or greater.

20. 20. The method of semiconductor processing of claim 18, wherein the chucking force at each protrusion of the plurality of protrusions is less than or equal to about 98% of the chucking force between each protrusion of the plurality of protrusions.

Images