Horizontal pre-cleaning two-stage down pressure mechanism with flexible portion

Abstract

An example chemical mechanical cleaning system may include a carrier head. In some embodiments, the system may include a motor coupled with the vehicle head. The motor is operable to rotate the carrier head about a central axis of the carrier head. The system may include a two-stage downforce actuator operable to translate the carrier head and the motor vertically between a lift position and a cleaning position. The down pressure actuator may include a first stage including a linear actuator operable to vertically translate the carrier head between the raised position and at least one upper 50% of a vertical travel distance between the raised position and the cleaning position. The lower pressure actuator may include a second stage including an expandable flexible portion operable to vertically translate the carrier head between the cleaning position and no more than lower 50% of the vertical distance.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Patent Application No. 18 / 483,971, filed October 10, 2023, entitled “HORIZONTAL PRE-CLEAN 2-STAGEDOWNFORCE MECHANISM WITH FLEXURE,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This technology relates to semiconductor systems, processes, and equipment. More specifically, this technology relates to cleaning films deposited on substrates. Background Technology

[0004] Integrated circuits are typically formed by sequentially depositing conductive layers, semiconducting layers, and / or insulating layers on a silicon wafer. Various manufacturing processes planarize layers on the substrate between processing steps. For example, in some applications, metal layers are polished to form vias, plugs, and / or lines in trenches of patterned layers, and overlays are planarized until the top surface of the patterned layer is exposed. In other applications, such as in photolithography, dielectric layers are planarized, and overlays are polished until the desired thickness remains above the underlying layer.

[0005] In some embodiments, pre-cleaning is required to remove contaminant particles by applying low-amplitude downforce against a cleaning or polishing pad. This cleaning method typically requires the substrate to be mounted on a carrier or polishing head. The exposed surface of the substrate is typically placed against a rotating pad. The carrier head applies a controllable load to the substrate to push it against the pad.

[0006] One challenge in this type of cleaning operation is achieving uniform cleaning of the entire substrate surface. Sometimes, due to the design of the pressure actuator in the cleaning system, it can be difficult to consistently control the magnitude of the downward pressure applied to the back of the substrate. This can make it difficult to clean substrates within a batch consistently. For example, when the substrate is pressed down against the cleaning pad with varying amounts of downward pressure, the cleaning rate may vary (e.g., higher downward pressure may result in a higher cleaning rate). This can adversely affect the system's ability to clean the substrate uniformly and may impact the final semiconductor product.

[0007] Therefore, there is a need for improved systems and methods for cleaning substrates to uniformly clean the entire surface area of ​​a batch of substrates. This and other needs are addressed by this technology. Summary of the Invention

[0008] An exemplary substrate cleaning system may include a carrier head. The system may include a motor coupled to the carrier head. The motor may be operable to rotate the carrier head about a central axis. The system may include a two-stage downforce actuator operable to vertically translate the carrier head and motor between a lift position and a cleaning position. The two-stage downforce actuator may include a first stage comprising a linear actuator operable to vertically translate the carrier head and motor between the lift position and at least 50% of the vertical travel distance between the lift position and the cleaning position. The two-stage downforce actuator may include a second stage comprising an expandable flexible portion operable to vertically translate the carrier head and motor between the cleaning position and at least 50% of the vertical distance between the lift position and the cleaning position.

[0009] In some embodiments, the linear actuator may include a pneumatic actuator. An expandable flexible portion may expand to vertically downward transport the carrier head and motor. An expandable flexible portion may contract to vertically upward transport the carrier head and motor. The top end of the expandable flexible portion may define a fluid inlet port. The fluid inlet port may be fluidly coupled to a fluid source. The top end of the expandable flexible portion may be coupled to the shaft of the motor, and the bottom end of the expandable flexible portion may be coupled to the shaft of the carrier head. A portion of the carrier head shaft extending above the expandable flexible portion may include a shoulder that forms a rigid stop when the top surface of the expandable flexible portion presses against the shoulder. The expandable flexible portion may include a dual flexible portion comprising an expandable top surface and an expandable bottom surface. The expandable flexible portion may include a peripheral edge. The expandable flexible portion may include an upper mounting hub coupled to the motor. The expandable flexible portion may include an upper flexible wall extending between and coupled to the peripheral edge and the upper mounting hub. The expandable flexible portion may include a lower mounting hub coupled to a carrier head. The expandable flexible portion may include a lower flexible wall extending between and coupled to a peripheral edge and the lower mounting hub. A first stage may include a rigid stop that limits the downward travel position of the linear actuator. The system may include a cleaning liner positioned below the carrier head. The expandable flexible portion may include polyetheretherketone (PEEK).

[0010] Some embodiments of this technology may encompass a two-stage downforce actuator. The actuator may include a first stage comprising a linear actuator operable to vertically translate the carrier head and motor between a lifting position and a vertical travel distance between the lifting and cleaning positions, at least 50% of the total vertical distance. The actuator may include a second stage comprising an expandable flexible portion operable to vertically translate the carrier head and motor between a cleaning position and a lifting and cleaning position, not exceeding 50% of the total vertical distance between the cleaning and cleaning positions.

[0011] In some embodiments, the expandable flexible portion can expand to vertically downward transport the carrier head and motor. The expandable flexible portion can contract to vertically upward transport the carrier head and motor. The expandable flexible portion can define an internal fluid chamber between its top and bottom walls. In the contracted state, the inner surface of the top wall can contact the inner surface of the bottom wall. In the contracted state, the inner surfaces of the top wall and bottom wall can be vertically spaced apart. The peripheral edge extending around the internal fluid chamber of the expandable flexible portion can include a thickened wall relative to the flexible portion of the top and bottom walls, the thickened wall defining the boundary of the internal fluid chamber. The top wall of the expandable flexible portion can include an upper mounting hub. The bottom wall of the expandable flexible portion can include a lower mounting hub.

[0012] Some embodiments of this technology may cover methods for cleaning substrates. Methods may include positioning the substrate within a carrier head of a cleaning system. Methods may include lowering the carrier head and substrate toward the upper surface of a pad without contacting the upper surface of the pad. Methods may include inflating an expandable flexible portion of the cleaning system to move the carrier head downward against the upper surface of the pad and press the substrate. Methods may include cleaning the substrate against the upper surface of the pad. In some embodiments, inflating the expandable flexible portion may include drawing fluid into an internal fluid chamber of the expandable flexible portion such that the bottom surface of the expandable flexible portion presses against the upper surface of the carrier head to press the carrier head and substrate downward against the pad.

[0013] These technologies can offer numerous advantages over conventional systems and techniques. For example, the cleaning system described herein can apply more repeatable and finely tunable downward pressure between substrates. This action can improve the cleaning uniformity across the entire surface of each substrate in a batch, thereby leading to improved chip yield. These and other embodiments are described in more detail below in conjunction with the accompanying drawings and any advantages and features of the described embodiments. Attached Figure Description

[0014] A further understanding of the nature and advantages of the disclosed technology can be achieved by referring to the remainder of the specification and the diagrams.

[0015] Figure 1 A schematic cross-sectional view of an exemplary cleaning system according to some embodiments of the present technology is illustrated.

[0016] Figure 2A The illustration shows a schematic partial cross-sectional view of an exemplary two-stage downforce actuator in a raised position according to some embodiments of the present technology.

[0017] Figure 2B The illustration shows the partial lowering position. Figure 2A A schematic cross-sectional view of a second-stage downforce actuator.

[0018] Figure 2C The illustration shows the cleaning location. Figure 2A A schematic cross-sectional view of a second-stage downforce actuator.

[0019] Figure 3A The illustration shows a schematic cross-sectional view of an exemplary expandable flexible portion in a contracted state according to some embodiments of the present technology.

[0020] Figure 3B The diagram illustrates the state of expansion. Figure 3A A schematic cross-sectional view of the expandable flexible section.

[0021] Figure 3C The illustration shows a schematic cross-sectional view of an exemplary expandable flexible portion in a contracted state according to some embodiments of the present technology.

[0022] Figure 3D The diagram illustrates the state of expansion. Figure 3C A schematic cross-sectional view of the expandable flexible section.

[0023] Figure 3E The illustration shows a schematic cross-sectional view of an exemplary expandable flexible portion in a contracted state according to some embodiments of the present technology.

[0024] Figure 3F The diagram illustrates the state of expansion. Figure 3E A schematic cross-sectional view of the expandable flexible section.

[0025] Figure 4 This is a flowchart of an exemplary method for cleaning a substrate according to some embodiments of the present technology.

[0026] Several accompanying figures are included as illustrations. It should be understood that the figures are for illustrative purposes and should not be considered as drawn to scale unless explicitly stated otherwise. Furthermore, the figures are provided as illustrations to aid understanding and may not include all aspects or information relative to the actual representation, and may include exaggerated material for illustrative purposes.

[0027] In the accompanying drawings, similar parts and / or features may have the same component symbol. Furthermore, various parts of the same type can be distinguished by the letters in the following component symbols that differentiate similar parts. If only the first component symbol is used in the specification, the description applies to any of the similar parts having the same first component symbol, regardless of the letters. Detailed Implementation

[0028] In conventional cleaning operations, it is often difficult to uniformly clean substrate surfaces to remove contaminant particles. Conventional substrate cleaning involves a carrier holding the substrate against a rotating cleaning or polishing pad, positioning the substrate downwards towards the cleaning pad. To facilitate the cleaning operation, downward pressure can be applied to the back side of the substrate to press against the pad and press the substrate surface. In conventional cleaning systems, downward pressure actuators are used to apply downward pressure by moving a carrier head holding the substrate and a motor of the carrier head downwards toward the pad. Such actuators utilize sliding components (e.g., bearings or sliding tracks) to facilitate the vertical translation of the carrier head and motor. However, the sliding motion between the translational components generates friction between the components, which can make it difficult to apply consistent downward pressure in a repeatable manner. In addition, the sliding components may experience static friction, which can significantly affect the actuator's ability to consistently apply the desired downward pressure amplitude between substrates. Applying inconsistent downward pressure between substrates can result in a batch of substrates being cleaned to varying degrees using the cleaning system, and may reduce the quality of the final semiconductor devices produced from such substrates.

[0029] This technology overcomes the problems of conventional cleaning systems by using a two-stage downforce actuator. This actuator uses a second stage to lower the substrate against the cleaning pad without the need for sliding components. For example, the first stage may include one or more sliding mechanisms to coarsely lower the substrate beyond at least half the travel range of the carrier head and motor. The second stage of the actuator may use an expandable flexible portion that lowers the substrate to the final portion of the carrier head's travel range to position it against the pad without generating friction. This action allows the actuator to more repeatably control the downforce applied to the substrate, thereby improving the consistency of cleaning operations for each substrate cleaned by the cleaning system.

[0030] While specific film cleaning processes utilizing the disclosed technology will be routinely specified in the remainder of this disclosure, it will be readily understood that the systems and methods described are equally applicable to a wide variety of other semiconductor processing operations and systems. Therefore, the technology should not be considered limited to use only with the described cleaning systems or processes. For example, the downpressure actuator described herein can be used to apply downpressure to a substrate during a cleaning operation. This disclosure will discuss a possible system that may be used in conjunction with the technology prior to the description of systems and methods or exemplary process operation sequences according to some embodiments of the technology. It should be understood that the technology is not limited to the described apparatus, and the discussed processes can be performed in any number of processing chambers and systems with any number of modifications, some of which will be mentioned below.

[0031] Figure 1 The illustration shows a schematic cross-sectional view of an exemplary cleaning system 100 according to some embodiments of the present technology. The cleaning system 100 includes a pressure plate assembly 102, which includes a lower pressure plate 104 and an upper pressure plate 106. The lower pressure plate 104 may define an internal volume or cavity through which connections can be made, and may include endpoint detection devices or other sensors or devices, such as eddy current sensors, optical sensors, or other components for monitoring cleaning and / or polishing operations or components. For example, and as further described below, fluid coupling can be formed by a line extending through the lower pressure plate 104, and the line can be accessed through the back side of the upper pressure plate 106. The pressure plate assembly 102 may include a cleaning or polishing pad 110 mounted on a first surface of the upper pressure plate. A substrate carrier 108 or carrier head may be positioned above and facing the cleaning pad 110. The pressure plate assembly 102 is rotatable about axis A, while the substrate carrier 108 is rotatable about axis B. The substrate carrier can also be configured to sweep back and forth along the pressure plate assembly from the inner diameter to the outer diameter, which can partially reduce wear from uneven surfaces of the cleaning pad 110. The cleaning system 100 may also include a fluid delivery arm 118 positioned above the cleaning pad 110 and used to deliver cleaning and / or polishing fluids (e.g., cleaning slurry) onto the cleaning pad 110. Additionally, the pad adjustment assembly 120 may be positioned above the cleaning pad 110 and may face the cleaning pad 110.

[0032] In some embodiments of the cleaning process, a rotating and / or sweeping substrate carrier 108 can apply downward pressure against a substrate 112, illustrated as dashed lines, which can be housed within or coupled to the substrate carrier. As the cleaning pad 110 rotates about the central axis of the pressure plate assembly, the applied downward force can press against the cleaning pad 110 and press down on the material surface of the substrate 112. The interaction between the substrate 112 and the cleaning pad 110 can occur in the presence of one or more cleaning fluids delivered by the fluid delivery arm 118. Typical cleaning fluids may include slurries formed from aqueous solutions, in which abrasive particles may be suspended. Typically, the cleaning fluid contains pH adjusters and other chemically active components, such as oxidants, which achieve cleaning of the material surface of the substrate 112.

[0033] The pad adjustment assembly 120 can be operated to apply a fixed abrasive adjustment disc 122 against the surface of the cleaning pad 110, the fixed abrasive adjustment disc 122 being rotatable as previously mentioned. The adjustment disc can be operated to abut the pad before, after, or during the cleaning of the substrate 112. By grinding, refurbishing, and removing byproducts and other debris from the cleaning surface of the cleaning pad 110 through polishing, the cleaning pad 110 can be maintained in a desired state by adjusting the cleaning pad 110 via the adjustment disc 122. The upper pressure plate 106 can be mounted on the mounting surface of the lower pressure plate 104 and can be coupled to the lower pressure plate 104 using a plurality of fasteners 138, such as an annular flange extending through the lower pressure plate 104.

[0034] The cleaning plate assembly 102, and therefore the upper platen 106, can be suitably sized for any desired cleaning system and can be sized for substrates of any diameter, including 200 mm, 300 mm, 450 mm, or larger. For example, a cleaning platen assembly configured for polishing a 300 mm diameter substrate may be characterized by a diameter greater than about 300 mm, such as between about 500 mm and about 1000 mm, or greater than about 500 mm. The diameter of the platen can be adjusted to accommodate substrates with larger or smaller diameters, or for cleaning platens 106 sized for parallel cleaning of multiple substrates. The upper platen 106 may be characterized by a thickness between about 20 mm and about 150 mm, and may be characterized by a thickness less than or about 100 mm, such as less than or about 80 mm, less than or about 60 mm, less than or about 40 mm, or smaller. In some embodiments, the ratio of the diameter to the thickness of the cleaning plate 106 may be greater than or about 3:1, greater than or about 5:1, greater than or about 10:1, greater than or about 15:1, greater than or about 20:1, greater than or about 25:1, greater than or about 30:1, greater than or about 40:1, greater than or about 50:1 or greater.

[0035] The upper and / or lower pressure plates may be formed of a suitable, rigid, lightweight, and fluid-resistant material, such as aluminum, aluminum alloy, or stainless steel, but any number of materials may be used. The cleaning pad 110 may be formed of any number of materials, including polymeric materials such as polyurethane, polycarbonate, fluoropolymers, polytetrafluoroethylene polysulfide, or any combination of these or other materials. Additional materials may be or include open-cell or closed-cell foamed polymers, elastomers, felt, impregnated felt, plastics, or any other material compatible with the chemicals being handled. It should be understood that the inclusion of cleaning system 100 is to provide a proper reference to the components discussed below, which may be incorporated into system 100, but the description of cleaning system 100 is not intended to limit the technology in any way, as embodiments of the technology may be incorporated into any number of cleaning systems that may benefit from the components and / or capabilities further described below.

[0036] Figures 2A to 2C A schematic cross-sectional side view of an exemplary cleaning system 200 according to some embodiments of the present technology is illustrated. The cleaning system 200 may illustrate a partial view of components discussed and including any components described associated with the cleaning system 100. The cleaning system 200 may include a carrier head 202. In some embodiments, the carrier head 202 may serve as a substrate carrier 108 and may include any features described associated with the substrate carrier 108. The carrier head 202 may be coupled to a motor 204 operable to rotate the carrier head 202 about a central axis during a cleaning operation. The motor 204 may include a fixed portion 206 and a rotatable portion 208 rotatable relative to the fixed portion 206. For example, the fixed portion 206 may include a stator assembly coupled to a housing 210 of the cleaning system 200. When current is supplied to the stator assembly, the stator assembly may generate a rotating magnetic field that causes the rotatable portion 208 to rotate relative to the fixed portion 206 and the housing 210. The carrier head 202 may be coupled to a rotatable portion 208, such as using one or more fasteners (e.g., bolts or screws) extending through a flange 214 of a motor shaft 216 coupled to the rotatable portion 208. The motor shaft 216 may extend through a central bore formed within a fixed portion 206. The motor shaft 216 may be rotatable within the central bore of the fixed portion 206. For example, the motor shaft 216 may be coupled to the rotatable portion 208, such as using one or more fasteners (e.g., bolts or screws) extending through a flange 214 of the motor shaft 216 into the rotatable portion 208.

[0037] The motor shaft 216 may define a central bore 218 extending through the length of the motor shaft 216. In some embodiments, the central bore 218 may have a constant diameter, or in other embodiments, it may have a variable diameter. For example, as illustrated, the central bore 218 has a smaller diameter at its top end (e.g., near the injection inlet) and a larger diameter at its bottom end. In some embodiments, the transition between the different diameters may be stepped, while in other embodiments, the transition may be linear and / or variablely tapering. In some embodiments, one or more components of the carrier head 202 may be disposed within the central bore 218. For example, the carrier head 202 may include a shaft 220, which may have an upper end and a lower end. The lower end of the shaft 220 may be coupled within an inner housing 260 of the carrier head 202, while the upper end of the shaft 220 may extend at least partially into the central bore 218. In some embodiments, the upper end of the shaft 220 may include a bushing 224, which may be formed of and / or coated with a low-friction material. For example, all or part of the bushing 224 may be formed of polytetrafluoroethylene (PTFE). In a particular embodiment, the bushing 224 may be formed of a PTFE-coated metal or polymeric material (e.g., polyetheretherketone (PEEK)). The bushing 224 can help facilitate substantially frictionless vertical translation within the central bore 218 to provide lateral stability, thus helping the carrier head 202 cope with lateral loads generated when the substrate moves against the top surface of the cleaning pad. The side surfaces of the top ends of the motor shaft 216 and the bushing 224 may be spaced apart from the inner wall of the central bore 218, such that a small air gap exists between the inner wall of the central bore 218 and the top side surfaces of the motor shaft 216 and the bushing 224. The air gap allows fluid to be introduced into the central bore 218 through the fluid source 226 and passed down through the bottom of the central bore 218, as described in more detail below.

[0038] The cleaning system 200 may include a two-stage downforce actuator 228 operable to vertically translate a carrier head 202 and a motor 204 between a lifting position and a cleaning position. In the lifting position, the carrier head 202 may be spaced apart from a cleaning pad (not shown), allowing a substrate to be loaded or unloaded from the carrier head 202 and positioned above the cleaning pad. In the cleaning position, the carrier head 202 may be lowered so that the substrate contacts and presses against the cleaning pad to perform a cleaning operation. The downforce actuator 228 may include a first stage 230, which includes a linear actuator 231 operable to vertically translate the carrier head 202 and motor 204 between and through an upper region of the vertical travel distance between the lifting and cleaning positions. For example, the upper region of the vertical travel distance may include at least 50%, 60%, 70%, 80%, 90%, or more of the upper travel distance. The downforce actuator 228 may include a second stage 232, which includes an expandable flexible portion 234 operable to vertically translate the carrier head 202 and motor 204 between the cleaning position and the lower region of the vertical distance between the cleaning position and the lifting position. The lower region may include the remaining vertical distance not belonging to the upper region. For example, the lower region may include no more than 50%, 40%, 30%, 20%, or 10% of the bottom travel distance, or less of the bottom travel distance. The second stage 232 may be operable to apply additional downforce to the carrier head 202 after the carrier head 202 has contacted the cleaning pad. Additional force can cause downward pressure to be applied to the carrier head (and subsequently to the substrate supported by the carrier head 202), thereby promoting substrate cleaning.

[0039] The first stage 230 can be used to coarsely adjust the vertical position of the motor 204 and the carrier head 202, for example, by providing vertical travel that exceeds at least half of the upper portion of the vertical travel range of the motor 204 and the carrier head 202. The first stage 230 may include one or more sliding components that can introduce sliding friction into the first stage. However, since the first stage 230 is not used to engage the carrier head 202 / substrate with the cleaning pad or to apply downward pressure to the substrate, this sliding friction does not affect the total downward pressure applied to the substrate. The second stage 232 can be used to control the vertical travel of the carrier head 202 and the substrate along the final vertical travel distance to engage the substrate with the cleaning pad. The second stage 232 may use non-sliding components to provide precise, fine, and repeatable adjustment of the downward pressure applied to the substrate.

[0040] As mentioned above, the first stage 230 may include a linear actuator 231. In some embodiments, the linear actuator 231 may include a pneumatic actuator that supplies air to a bellows 236, which is coupled to the housing 210. When air is drawn into the bellows 236, the bellows 236 may expand axially in a downward direction. The upper end of the bellows 236 may be fixed relative to the housing 210, while the lower portion of the bellows 236 may move freely vertically relative to the housing 210. A portion of the bellows 236 (e.g., the lower portion of the bellows housing) may be coupled to a support 238 that extends between and couples the bellows 236 and the fixed portion 206 of the motor 204. When the bellows 236 expands axially, the support 238 may be pushed downward, which may force the motor 204 to translate downward relative to the housing 210. When the bellows 236 contracts (e.g., air is removed from the bellows 236), the support 238 is pulled upward to lift the motor 204. The motor 204, and specifically the stationary portion 206, may be coupled to one or more bearings and / or tracks that guide the vertical translation of the motor 204. The first stage 230 may include one or more hard stops that restrict the vertical travel of the motor 204 in a given direction.

[0041] As mentioned above, the second stage 232 may include an expandable flexible portion 234, which may be disposed within a chamber 240 formed within the rotatable portion 208 of the motor 204. In some embodiments, the chamber 240 may be defined to be larger than the expandable flexible portion 234, allowing the expandable flexible portion 234 to expand vertically within the chamber 240. The expandable flexible portion 234 may be coupled to the rotatable portion 208 of the motor 204 and to the carrier head 202. For example, the expandable flexible portion 234 may include an upper mounting hub 242, which may be coupled to the rotatable portion 208 of the motor 204. For example, one or more fasteners 244 may extend through and secure the flange 214 of the motor shaft 216 and the upper mounting hub 242 of the expandable flexible portion 234. In some embodiments, the upper surface of the upper mounting hub 242 may contact the lower surface of the motor shaft 216, the flange 214, and / or the underside of the shoulder 222 of the shaft 220 of the carrier head 202. The expandable flexible portion 234 may include a lower mounting hub 246, which may be coupled to the shaft 220 of the carrier head 202. For example, one or more fasteners 247 may extend through and secure the flange 250 of the shaft 22 of the carrier head 202 and the lower mounting hub 246 of the expandable flexible portion 234. Each mounting hub may define a central bore that receives the shaft 220 of the carrier head 202. The central bore in the upper mounting hub 242 may be slightly larger than the shaft 220, allowing for an air gap through the bore. Fluid (e.g., air) can be drawn around the bushing 224 and the top of the motor shaft 216 through the central bore 218 of the motor shaft 216 and into the internal fluid chamber 248 of the expandable flexible portion 234. Introducing fluid into the internal fluid chamber 248 causes the expandable flexible portion 234 to expand along its vertical axis, wherein the upward expansion of the expandable flexible portion 234 is limited by contact between the upper surface of the upper mounting hub 242 and the lower side of the flange 214 of the motor shaft 216. This contact causes the expandable flexible portion 234 to expand downward, wherein the lower mounting hub 246 pushes downward the flange 250 of the shaft 220 of the carrier head 202. The downward movement of the shaft 220 pushes the carrier head 202 downward so that the substrate secured within the carrier head 202 contacts the cleaning pad. Once the substrate contacts the cleaning pad, the expandable flexible portion can expand further to increase the amount of downward pressure applied to the carrier head 202 and the substrate.

[0042] In the initial state, the motor 204 and the carrier head 202 are in the raised position, wherein the motor 204 and the carrier head 202 are spaced apart from the cleaning pad by a vertical distance, such as Figure 2AAs shown. In the raised position, the bellows 236 can be in the retracted state, and the bracket 238 can support the motor 204 in the raised position. The first stage 230 can be actuated to move the motor 204 and the carrier head 202 downward toward the cleaning pad, but without contacting the cleaning pad, as shown. Figure 2B As shown in the diagram. When air or other fluid is introduced into the bellows 236, the bellows 236 can expand axially, which can exert a downward force on the support 238. The downward movement of the support 238 can cause the motor 204 and the carrier head 202 to move downward accordingly. The downward movement caused by the first stage 230 can be limited by one or more rigid stops. Once the first stage 230 has been fully actuated, the second stage 232 can be actuated to translate the motor 204 and the carrier head downward, so that the substrate supported by the carrier head 202 contacts the cleaning pad, as shown. Figure 2C As shown. For example, air or other fluid can be introduced from a fluid source through the central hole 218 of the motor shaft 216 into the internal fluid chamber 248 of the expandable flexible portion 234 to expand the expandable flexible portion 234. The expansion of the expandable flexible portion 234 can cause it to expand along a vertical axis and push downwards the flange 250 of the shaft 220 of the carrier head 202. The downward movement of the shaft 220 can push the carrier head 202 downwards so that the substrate secured within the carrier head 202 contacts the cleaning pad. Once the substrate contacts the cleaning pad, the expandable flexible portion can expand further to increase the amount of downward pressure applied to the carrier head 202 and the substrate.

[0043] Figures 3A to 3FThe illustration shows a cross-sectional side view of an exemplary expandable flexible portion 300 according to some embodiments of the present technology. The expandable flexible portion 300 can be used as an expandable flexible portion 234 in a cleaning system 200 or as an expandable flexible portion in any other cleaning system that would benefit from this type of technology. Each expandable flexible portion 300 may include a top wall 302 and a bottom wall 304, which are coupled together at a peripheral edge 306. The peripheral edge 306, the top wall 302, and the bottom wall 304 may be radially inwardly non-connected, such that an internal fluid chamber 308 is defined between the inner surfaces of the top wall 302 and the bottom wall 304. The top wall 302 may include an upper mounting hub 310, which can be used to mount the expandable flexible portion 300 to a motor (e.g., motor 204), such as by inserting one or more fasteners through the upper mounting hub 310 and the motor's shaft. The bottom wall 304 may include a lower mounting hub 312 for mounting the expandable flexible portion 300 to a carrier head (e.g., carrier head 202), such as by inserting one or more fasteners through the lower mounting hub 312 and the shaft of the carrier head. The upper mounting hub 310 and the lower mounting hub 312 may each define a central bore 314, which allows the expandable flexible portion 300 to be mounted on the shaft of the carrier head and can also serve as a fluid inlet port for introducing air or another fluid into the internal fluid chamber 308 to expand or inflate the expandable flexible portion 300. The expandable flexible portion 300 can expand to vertically move the carrier head and motor downwards, and can contract to vertically move the carrier head and motor upwards.

[0044] As illustrated, each expandable flexible portion 300 is a dual-flexible portion, wherein both the top wall 302 and the bottom wall 304 are designed to flex to accommodate the expansion of the internal fluid chamber 308 after fluid is introduced into it. For example, the top wall 302 may include an upper flexible wall 316 extending between and coupled to the upper mounting hub 310 and the peripheral edge 306. The bottom wall 304 may include a lower flexible wall 318 extending between and coupled to the lower mounting hub 312 and the peripheral edge 306. To enable the upper flexible wall 316 and lower flexible wall 318 to flex, while simultaneously providing structural rigidity to the expandable flexible portion 300 via the upper mounting hub 310, lower mounting hub 312, and periphery 306, the upper flexible wall 316 and lower flexible wall 318 may be thinner than the upper mounting hub 310, lower mounting hub 312, and periphery 306. For example, the upper mounting hub 310 and lower mounting hub 312 may each have a thickness between approximately 3 mm and 10 mm, between approximately 3.5 mm and 8 mm, or between approximately 3.5 mm and 8 mm, or between approximately 4 mm and 6 mm, or between approximately 4 mm and 6 mm. The peripheral edge 306 may have a thickness between approximately 2 mm and 5 mm, or between approximately 3 mm and 4 mm, or between approximately 3 mm and 4 mm. The upper flexible wall 316 and the lower flexible wall 318 may each have a thickness between about 1 mm and 2 mm, or about 1 mm and 2 mm, between about 1.2 mm and 1.8 mm, or between about 1.4 mm and 1.6 mm, or about 1.4 mm and 1.6 mm. The expandable flexible portion 300 may be formed of a material that is sufficiently strong and rigid at its greater thickness (e.g., at the upper mounting hub 310 and the lower mounting hub 312) to support mounting by one or more fasteners, while being sufficiently flexible or elastic at its lesser thickness (e.g., at the upper flexible wall 316 and the lower flexible wall 318) to facilitate expansion of the expandable flexible portion 300 when fluid is introduced into the internal fluid chamber 308. Such materials may include polymeric materials. In a particular embodiment, the expandable flexible portion may be formed of polyetheretherketone (PEEK). In some embodiments, the diameter of the expandable flexible portion 300 may be between about 80 mm and 150 mm, or about 80 mm and 150 mm, between about 90 mm and 135 mm, or between about 100 mm and 120 mm, or about 100 mm and 120 mm, but other sizes of expandable flexible portions 300 may be used in the various embodiments. In embodiments with diameters exceeding these ranges, the thickness of the various portions of the expandable flexible portion may be increased accordingly.

[0045] Figure 3A The expandable flexible portion 300a in its contracted state is shown. Here, the inner surfaces of the top wall 302a and the bottom wall 304a are in contact with each other, such that the internal fluid chamber 308a is substantially volumeless. The annular transition region 320a between the upper mounting hub 310a and the upper flexible wall 316a can taper with a linear or variable slope. As illustrated, a variable, curved transition region 320a is provided. In some embodiments, the radius of the transition region 320a can be between about 10 mm and 40 mm, or about 10 mm and 40 mm, or between about 15 mm and 30 mm, or about 15 mm and 30 mm, but other radii may be used in various embodiments. The annular transition region 322a between the peripheral edge 306 and the upper flexible wall 316 can taper with a linear or variable slope. As illustrated, a variable curved transition region 322a is provided. In some embodiments, the radius of the transition region 322a may be between about 10 mm and 20 mm, or between about 10 mm and 40 mm, or between about 12 mm and 15 mm, or between about 15 mm and 30 mm, but other radii may be used in various embodiments. A smaller transition radius can increase the travel distance of the expandable flexible portion 300a. Figure 3B The expandable flexible portion 300a in an inflated or expanded state is shown. Here, the inner surfaces of the top wall 302a and the bottom wall 304a are vertically spaced apart, causing the internal fluid chamber 308a to have an expanded volume. The expansion of the internal fluid chamber 308a can push the upper mounting hub 310a and the lower mounting hub 312a vertically spaced apart, which allows the expandable flexible portion 300a to push the carrier head downward away from the motor, as described elsewhere herein.

[0046] Figure 3C The expandable flexible portion 300c in its contracted state is shown. Here, the inner surfaces of the top wall 302c and the bottom wall 304c are vertically spaced apart from each other, such that an internal fluid chamber 308c forms a cavity between the top wall 302c and the bottom wall 304c. In this embodiment, the top and bottom boundaries of the internal fluid chamber 308c may be substantially planar, while the peripheral edge of the internal fluid chamber 308c may be rounded. The annular transition region 320c between the upper mounting hub 310c and the upper flexible wall 316c may be substantially stepped, but may include inner rounded corners as shown herein. In the illustrated embodiment, the top surfaces of the upper flexible wall 316c and the peripheral edge 306c may be coplanar, thus eliminating the need for a transition region. Similarly, the bottom surfaces of the lower flexible wall 318c and the peripheral edge 306c may be coplanar. Figure 3DThe expandable flexible portion 300c in its expanded or inflated state is shown. Here, compared to the contracted position, the inner surfaces of the top wall 302c and the bottom wall 304c are vertically spaced apart by a greater distance, causing the internal fluid chamber 308c to have an expanded volume. The expansion of the internal fluid chamber 308c can push the upper mounting hub 310c and the lower mounting hub 312c vertically spaced apart, which allows the expandable flexible portion 300c to push the carrier head downward away from the motor, as described elsewhere herein.

[0047] Figure 3E The expandable flexible portion 300e in its contracted state is shown. Here, the inner surfaces of the top wall 302e and the bottom wall 304e are vertically spaced apart from each other, such that an internal fluid chamber 308e forms a cavity between the top wall 302e and the bottom wall 304e. In this embodiment, the top and bottom boundaries of the internal fluid chamber 308e may be substantially planar, while the peripheral edge of the internal fluid chamber 308e may be tapered and may terminate at a point or at a bend with a small radius. The annular transition region 320e between the upper mounting hub 310e and the upper flexible wall 316e may be substantially stepped, but may include inner rounded corners as shown herein. In the illustrated embodiment, the top surfaces of the upper flexible wall 316e and the peripheral edge 306e may be coplanar, thus eliminating the need for a transition region. Similarly, the bottom surfaces of the lower flexible wall 318e and the peripheral edge 306e may be coplanar. Figure 3F The expandable flexible portion 300e in its expanded or inflated state is shown. Here, compared to its contracted position, the inner surfaces of the top wall 302e and the bottom wall 304e are vertically spaced apart by a greater distance, causing the internal fluid chamber 308e to have an expanded volume. The expansion of the internal fluid chamber 308e can push the upper mounting hub 310e and the lower mounting hub 312e vertically spaced apart, which allows the expandable flexible portion 300e to push the carrier head downward away from the motor, as described elsewhere herein.

[0048] As mentioned above, each expandable flexible portion 300 is a dual-flexible portion, which allows expansion of both the top and bottom walls. The dual-flexible portion is not only operable to uniformly apply low downforce to the carrier head and substrate, but also capable of handling lateral forces and / or torque forces generated between the substrate and the cleaning pad during cleaning operations by rotational and / or lateral sweeping contacts. In some embodiments, each expandable flexible portion 300 may be symmetrical, wherein the top and bottom walls have identical structures that are inverted relative to each other. In some embodiments, an asymmetrical design may be utilized. For example, expandable flexible portions that enhance expansion in specific areas and / or directions may be used. For example, in some embodiments, the expandable flexible portion may be a single-flexible design, wherein only one of the top or bottom walls expands when fluid is introduced into the internal fluid cavity 308. For example, the top wall 302 may be thickened to prevent expansion or other deflection, while the bottom wall 304 remains thin to allow expansion of the bottom wall 304. It should be understood that other designs for the expandable flexible portion are possible in the various embodiments.

[0049] The expandable flexible portions (e.g., expandable flexible portions 234 and 300) can be formed by various processes. For example, the top and bottom walls of each expandable flexible portion can be formed independently by molding, casting, or otherwise. Subsequently, the peripheral edges of the top and bottom walls of the expandable flexible portions can be joined using adhesives, fasteners, RF welding, and / or other joining techniques that can create an airtight seal at the peripheral edges of the expandable flexible portions. In some embodiments, sealing components, such as O-rings or gaskets, can be provided between the different surfaces coupled together to form the peripheral edges. In some embodiments, the expandable flexible portions can be produced using a laminated manufacturing technique that can fabricate the expandable flexible portions as a single piece without seams between the top and bottom walls. Thus, such manufacturing techniques can provide naturally airtight components that are more robust and do not require the use of additional sealing components, such as O-rings.

[0050] In one particular embodiment, a 3D printer can be used to stack the structure of the expandable flexible portion layer by layer to create a monolithic expandable flexible portion structure. To create the internal fluid chamber, a soluble support material can be positioned on top of the bottom wall, as when forming the peripheral edges. The size and shape of the soluble support material can match the thickness of the internal fluid chamber. For example, when the expandable flexible portion is in a contracted state, the thickness of the soluble support material can match the height of the internal fluid chamber. In embodiments where the internal fluid chamber is closed (e.g., the top and bottom walls are in contact with each other in the contracted state), the soluble support material can be a sheet of soluble paper or other material that allows the top wall to be printed or deposited on top of the bottom wall, but not bonded to it. Once the expandable flexible portion has been fully formed and cured, it can be exposed to a solvent to dissolve the support material, leaving only the final expandable flexible portion material. For example, the expandable flexible portion can be positioned in a bath of solvent. In some embodiments, the solvent can be agitated, such as by using a mechanical stirrer and / or an ultrasonic stirrer, which can help force the solvent into the tight space of the internal fluid chamber. In some embodiments, the expandable flexible portion can at least partially expand while being exposed to a solvent to better allow the solvent to reach all surfaces defining the internal fluid chamber. For example, the expandable flexible portion can be fluid-expanded and / or mechanically flexed by pulling the top and bottom walls apart. After dissolving the support structure, the solvent can be removed from the expandable flexible portion. For example, the expandable flexible portion can be dried, vacuumed, and / or otherwise treated to remove the solvent.

[0051] Figure 4 Exemplary operation of a method 400 for cleaning a substrate according to some embodiments of the present technology is illustrated. Method 400 can be performed using a carrier head (e.g., carrier head 108 or carrier head 202) and a two-stage downforce actuator (e.g., downforce actuator 228) including an expandable flexible portion (e.g., expandable flexible portion 234 or expandable flexible portion 300) described herein. In some embodiments, method 400 may include operations prior to substrate cleaning. For example, prior to cleaning, the substrate may have undergone one or more deposition and / or etching operations, as well as any planarization or other process operations. Method 400 may include a large number of operations that can be performed automatically within a system to limit human interaction and provide enhanced efficiency and accuracy superior to manual operation. Method 400 may be performed as part of or in conjunction with conventional cleaning processes.

[0052] Method 400 may include operation 405, positioning the substrate within the carrier head of the cleaning system. For example, the substrate may be positioned on the substrate receiving surface of a diaphragm abutting the carrier head. Method 400 may include operation 410, lowering the carrier head and substrate toward the upper surface of the cleaning pad without contacting the upper surface of the cleaning pad. This step may be accomplished, for example, using a first stage of a downforce actuator. The first stage may include one or more sliding structures driven by a pneumatic actuator. For example, air or other fluid may be introduced into a bellows, causing the bellows to expand axially, which may force the support of the retaining motor and carrier head downward along one or more bearings and / or sliding tracks.

[0053] In operation 415, the expandable flexible portion of the cleaning system can be expanded to move the carrier head downward against the upper surface of the cleaning pad and press the substrate. This operation may involve, for example, drawing fluid into the internal fluid chamber of the expandable flexible portion, such that the bottom surface of the expandable flexible portion presses against the upper surface of the carrier head (e.g., the axis of the carrier head) against the cleaning pad, pressing the carrier head and the substrate downward. After the substrate contacts the cleaning pad, expansion can continue, wherein the enhanced expansion of the expandable flexible portion increases the amount of downward pressure applied to the substrate.

[0054] In operation 420, the substrate can be cleaned against the upper surface of the cleaning pad. For example, the carrier head can rotate and / or translate (or sweep) the substrate around the surface of the cleaning pad, such that abrasive particles in the cleaning slurry supplied to the cleaning pad can gradually remove material from the substrate surface in the desired pattern and / or achieve the desired film thickness profile. In some embodiments, instead of rotating and / or translating the carrier head, the cleaning pad can be rotated and / or translated.

[0055] In the foregoing description, numerous details have been set forth for purposes of explanation in order to provide an understanding of various embodiments of the present technology. However, it will be apparent to those skilled in the art that certain embodiments may be practiced without some of these details or with additional details.

[0056] Several embodiments have been disclosed, and those skilled in the art will recognize that various modifications, alternative constructions, and equivalents can be used without departing from the scope of the described embodiments. Furthermore, numerous well-known processes and components 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.

[0057] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly or conventionally understood. As used herein, the articles “a” and “an” refer to one or more (that is, at least one) grammatical objects of the article. For example, “a component” means one or more components. As used herein, “about” and / or “approximately” when referring to measurable values ​​(e.g., quantities, temporary durations, and the like) cover variations of ±20%, ±10%, ±5%, or +0.1% from the specified value, as such variations are appropriate in the context of the systems, apparatuses, circuits, methods, and other embodiments described herein. As used herein, “substantially” when referring to measurable values ​​(e.g., quantities, temporary durations, physical properties (e.g., frequencies), and the like) also cover variations of ±20%, ±10%, ±5%, or +0.1% from the specified value, as such variations are appropriate in the context of the systems, apparatuses, circuits, methods, and other embodiments described herein.

[0058] When a range of values ​​is provided, it should be understood that each intermediate value between the upper and lower limits of the range, down to the smallest portion of the lower limit unit, is also specifically disclosed, unless the context explicitly states otherwise. This encompasses any narrower range between any unstated intermediate value in any of the stated values ​​or the range and any other stated or intermediate value in the range. The upper and lower limits of the narrower range may be independently included or excluded from the range, and each range in which any limit value, an infinite value, or both limit values ​​are included is also covered within this technology, depending on any specifically excluded limit value in the range. When the range includes one or both limit values, it also includes ranges that exclude one or both of the included limit values.

[0059] As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include multiple references unless the context clearly specifies otherwise. Thus, for example, reference to “a heater” includes multiple such heaters, and reference to “the protrusion” includes one or more protrusions and equivalents known to those skilled in the art, and so on.

[0060] Additionally, the terms “comprise(s)”, “comprising”, “contains(s)”, “containing”, “include(s)”, and “including” are intended to specify the presence of the stated feature, integer, component, or operation when used in this specification and the following claims, but do not exclude the presence or addition of one or more other features, integers, components, operations, or groups thereof.

Claims

1. A chemical mechanical cleaning system, comprising: Vehicle head; A motor coupled to the carrier head, the motor being operable to rotate the carrier head about a central axis; A two-stage downforce actuator operable to vertically translate the carrier head and the motor between a lifting position and a cleaning position, wherein the two-stage downforce actuator comprises: The first stage includes a linear actuator operable to vertically translate the carrier head and the motor between at least 50% of the vertical travel distance between the lifting position and the cleaning position. and The second stage includes an expandable flexible portion operable to vertically translate the carrier head and the motor between the cleaning position and the lifting position, and between the cleaning position and the vertical distance of no more than 50%.

2. The chemical mechanical cleaning system according to claim 1, wherein: The linear actuator includes a pneumatic actuator.

3. The chemical mechanical cleaning system according to claim 1, wherein: The expandable flexible portion expands to vertically and downwardly move the carrier head and the motor; The expandable flexible portion retracts to vertically move the carrier head and the motor upwards; and The top of the expandable flexible portion defines a fluid inlet port.

4. The chemical mechanical cleaning system according to claim 3, wherein: The fluid inlet port is fluidly coupled to the fluid source.

5. The chemical mechanical cleaning system according to claim 1, wherein: The top end of the expandable flexible portion is coupled to the shaft of the motor, and the bottom end of the expandable flexible portion is coupled to the shaft of the carrier head.

6. The chemical mechanical cleaning system according to claim 5, wherein: The portion of the vehicle head shaft extending above the expandable flexible portion includes a shoulder member, which forms a rigid stop when the top surface of the expandable flexible portion presses against the shoulder member.

7. The chemical mechanical cleaning system according to claim 1, wherein: The expandable flexible portion includes a dual flexible portion, which includes an expandable top surface and an expandable bottom surface.

8. The chemical mechanical cleaning system according to claim 1, wherein: The expandable flexible portion includes: Peripheral edges; A wheel hub is mounted on top and coupled to the motor; An upper flexible wall extends between the peripheral edge and the upper mounting hub and is coupled to the peripheral edge and the upper mounting hub; The lower mounting hub is coupled to the vehicle head; and A lower flexible wall extends between the peripheral edge and the lower mounting hub and couples the peripheral edge and the lower mounting hub.

9. The chemical mechanical cleaning system according to claim 1, wherein: The first stage includes a hard stop that limits the downward travel position of the linear actuator.

10. The chemical mechanical cleaning system according to claim 1, further comprising: A cleaning pad is placed under the vehicle head.

11. The chemical mechanical cleaning system according to claim 1, wherein: The expandable flexible portion comprises polyetheretherketone (PEEK).

12. A two-stage downforce actuator, comprising: The first stage includes a linear actuator operable to vertically translate the carrier head and motor between a lifting position and at least 50% of the vertical travel distance between the lifting position and the cleaning position; and The second stage includes an expandable flexible portion operable to vertically translate the carrier head and the motor within a range not exceeding 50% of the vertical distance between the cleaning position and the lifting position.

13. The two-stage downforce actuator according to claim 12, wherein: The expandable flexible portion expands to vertically and downwardly move the carrier head and the motor; and The expandable flexible portion retracts to vertically move the carrier head and the motor upwards.

14. The two-stage downforce actuator according to claim 12, wherein: The expandable flexible portion defines the internal fluid chamber between the top and bottom walls of the expandable flexible portion.

15. The two-stage downforce actuator according to claim 14, wherein: In the contracted state, the inner surface of the top wall is in contact with the inner surface of the bottom wall.

16. The two-stage downforce actuator according to claim 14, wherein: In the contracted state, the inner surface of the top wall is vertically spaced from the inner surface of the bottom wall.

17. The two-stage downforce actuator according to claim 14, wherein: The peripheral edge extending around the internal fluid chamber of the expandable flexible portion includes a thickened wall relative to the flexible portions of the top and bottom walls, the thickened wall defining the boundary of the internal fluid chamber.

18. The two-stage downforce actuator according to claim 14, wherein: The top wall of the expandable flexible portion includes an upper-mounted hub; and The bottom wall of the expandable flexible portion includes a lower-mounted hub.

19. A method for cleaning a substrate, comprising the following steps: Position the substrate within the carrier head of the cleaning system; The carrier head and the base plate are lowered toward the upper surface of the cleaning pad without contacting the upper surface of the cleaning pad; The expandable flexible portion of the cleaning system is expanded to move the carrier head downwards to press the substrate against the upper surface of the cleaning pad. and The substrate is cleaned by abutting against the upper surface of the cleaning pad.

20. The method for cleaning a substrate according to claim 19, wherein: The step of inflating the expandable flexible portion includes the following steps: drawing fluid into the internal fluid chamber of the expandable flexible portion, such that the bottom surface of the expandable flexible portion presses against the upper surface of the carrier head, thereby pressing the carrier head and the substrate downward against the cleaning pad.

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