Profile Control Polishing Platen

Abstract

The chemical mechanical polishing assembly may include an upper platen characterized by a first surface and a second surface opposite the first surface. The upper platen may define a recess in the second surface of the upper platen. The upper platen may define a flexure between the first surface and the second surface within the recess. The assembly may include a polishing pad coupled to the first surface of the upper platen. The assembly may include a plate coupled to the upper platen along the second surface of the upper platen. The plate may define an area between the second surface of the upper platen and the plate within the recess of the upper platen.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 166,692, entitled "CONTROLLED PROFILE POLISHING PLATEN," filed March 26, 2021, the entire contents of which are incorporated herein by reference.

[0002]

[0002] The present technology relates to semiconductor systems, processes, and apparatus. More particularly, the present technology relates to components incorporated into chemical mechanical polishing systems. [Background technology]

[0003] Chemical mechanical polishing is commonly used in semiconductor processing to planarize or polish layers of material formed on semiconductor substrates. In a typical process, the substrate is pressed against a rotating polishing pad and a polishing slurry is flowed over it. Material formed along the substrate is removed by a combination of chemical interaction with the polishing slurry and mechanical interaction with the polishing pad. As process complexity increases and the non-uniformity of material formation on the substrate increases, standard chemical mechanical polishing systems may not be able to adequately accommodate the material structures being polished.

[0004]

[0004] Therefore, there is a need for improved systems and methods that can be used to improve systems to increase the accuracy of polishing and removal. These and other needs are addressed by the present technology. Summary of the Invention

[0005] The chemical mechanical polishing assembly may include an upper platen characterized by a first surface and a second surface opposite the first surface. The upper platen may define a recess in the second surface of the upper platen. The upper platen may define a flexure within the recess between the first surface and the second surface. The assembly may include a polishing pad coupled to the first surface of the upper platen. The assembly may include a plate coupled to the upper platen along the second surface of the upper platen. The plate may define an area between the second surface of the upper platen and the plate within the recess of the upper platen.

[0006] In some embodiments, the recess defined in the second surface of the upper platen may be an annular recess defined near the upper platen. The recess defined in the second surface of the upper platen may be a stepped recess. The plate may be coupled to the upper platen along a recess ledge within the stepped recess. The area defined within the recess in the upper platen may be sealed with an elastomeric element disposed between the plate and the second surface of the upper platen. One or more stops may extend from the plate toward the flexure of the upper platen. The one or more stops may define a maximum deflection distance of the flexure defined by the upper platen. The one or more stops may include multiple stops. A first stop of the multiple stops may be characterized by a different height than a second stop of the multiple stops. The assembly may include a pneumatic pump fluidly coupled to the area within the recess in the upper platen. A fluid line from the pneumatic pump may be coupled to the plate. The assembly may include a compliant wall extending from the plate within the recess to the second surface of the upper platen. The compliant wall may divide an area within the recess of the upper platen into a first zone and a second zone. The first zone may be fluidly isolated from the second zone. The pneumatic pump may include a first fluid line extending to the first zone and a second fluid line extending to the second zone. The pneumatic pump may be operable to separately pump or purge each of the first zone and the second zone. The flexure may be characterized by a cross-sectional thickness that varies throughout the flexure.

[0007] Some embodiments of the present technology may include a polishing assembly. The assembly may include an upper platen characterized by a first surface and a second surface opposite the first surface. The upper platen may define a recess in the second surface of the upper platen. The upper platen may be characterized by a first cross-sectional thickness outside the recess. The upper platen may be characterized by a second cross-sectional thickness along a portion defining the recess. The assembly may include a polishing pad coupled to the first surface of the upper platen. The assembly may include a plate coupled to the upper platen along the second surface of the upper platen. The plate may define an area between the second surface of the upper platen and the plate within the recess of the upper platen.

[0008] In some embodiments, the second cross-sectional thickness may be characterized by a thickness of about 15 mm or less. The portion of the upper platen characterized by the second cross-sectional thickness of the upper platen may be located across a central axis of the upper platen. One or more protrusions may extend from the plate toward the upper platen. Each of the one or more protrusions may be characterized by an annular shape near the plate. The assembly may include a pneumatic pump fluidly coupled to a region within the recess of the upper platen. A fluid line from the pneumatic pump may be coupled to the plate. The assembly may include a bellows extending from the plate through the region to the second surface of the upper platen. The bellows may divide the region within the recess of the upper platen into a first zone and a second zone. The first zone may be fluidly isolated from the second zone. The pneumatic pump may include a first fluid line extending to the first zone and a second fluid line extending to the second zone. The pneumatic pump may be operable to separately pump to or purge from each of the first and second zones.

[0009] Some embodiments of the present technology may include a polishing assembly. The assembly may include an upper platen characterized by a first surface and a second surface opposite the first surface. The upper platen may define a recess in the second surface of the upper platen. The upper platen may define a flexure within the recess between the first surface and the second surface. The assembly may include a polishing pad coupled to the first surface of the upper platen. The assembly may include a plate coupled to the upper platen along the second surface of the upper platen. The plate may define an area within the recess in the upper platen between the second surface of the upper platen and the plate. The assembly may include a pneumatic pump fluidly coupled to an area within the recess in the upper platen. A fluid line from the pneumatic pump may fluidly access the area.

[0010] In some embodiments, the flexures may be characterized by a cross-sectional area that varies throughout the flexures. The assembly may include a compliant wall extending from the plate through a region to the second surface of the upper platen. The compliant wall may divide a region within the recess in the upper platen into a first zone and a second zone. The first zone may be fluidly isolated from the second zone. The pneumatic pump may include a first fluid line extending to the first zone and a second fluid line extending to the second zone. The pneumatic pump may be operable to separately pump or purge each of the first and second zones. One or more protrusions may extend from the plate toward the upper platen. The one or more protrusions may define a maximum inward deflection distance of the flexures.

[0011] The above technology may offer numerous advantages over conventional systems and techniques. For example, the flexures in the platen may allow for improved conformance of exposed material along the semiconductor substrate being polished. Furthermore, the platen configuration of the present technology is able to accommodate unique contact behavior across the entire substrate surface, rather than affecting positions limited to specific radial locations. These and other embodiments, along with their many advantages and features, are described in more detail in conjunction with the following description and accompanying drawings.

[0012] 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 the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view of an exemplary processing system according to some embodiments of the present technique; [Figure 2] 1A and 1B are schematic partial cross-sectional views illustrating an exemplary polishing assembly according to some embodiments of the present technique. [Figure 3] 1 is a schematic partial cross-sectional view illustrating an exemplary polishing assembly according to some embodiments of the present technique; [Figure 4] 1 is a schematic partial cross-sectional view illustrating an exemplary polishing assembly according to some embodiments of the present technique; [Figure 5] 1A and 1B are schematic partial cross-sectional views illustrating an exemplary polishing assembly according to some embodiments of the present technique. [Figure 6] 1A-1D illustrate selected steps in a method of semiconductor processing in accordance with some embodiments of the present technique. DETAILED DESCRIPTION OF THE INVENTION

[0014]

[0019] Some of the figures are included as schematic diagrams. It should be understood that the figures are for illustrative purposes and should not be considered to scale unless the scale is explicitly stated. Furthermore, schematic diagrams are provided to aid in understanding and may not include all aspects or information compared to realistic representations and may include exaggerated material for illustrative purposes.

[0015]

[0020] In the accompanying figures, similar components and / or features may be labeled with the same reference label. Furthermore, various components of the same type may be distinguished by following the reference label with a letter that distinguishes between the similar components. When only a first reference label is used herein, the description is applicable to any one of the similar components having the same first reference label, regardless of the letter.

[0016]

[0021] Chemical mechanical polishing often involves a multi-component system including a polishing assembly and a carrier head. A semiconductor substrate can be clamped to the carrier head, inverted, and pressed down onto a polishing pad on the polishing assembly. When removing multiple films characterized by non-uniform features or different physical properties, some systems may be able to adjust the pressure at which different zones of the substrate contact the polishing pad. For example, the carrier head may include a chamber that can adjust the pressure to increase or decrease the pressure applied to the substrate in that area. Similarly, a retaining ring extending outside the substrate can be pressed with higher or lower pressure to affect the overall effect on the substrate.

[0017]

[0022] While these systems can provide a high degree of control over the polishing process, they can be limited in terms of specific fine-tuning. For example, pressure can be applied to a zone behind the substrate, but the chamber in the carrier head can often be circular or annular and may only affect a specific radial zone near the substrate. Furthermore, because the force must be applied through the thickness of the substrate, adjusting the pressure behind the substrate can limit fine-tuning of the polishing.

[0018]

[0023] The present technology overcomes these problems in conventional polishing systems by providing an adjustable surface on the polishing platen. Allowing the shape of the polishing platen to be altered allows for improved direct correspondence to the front side of the substrate being processed and where the material being removed is located. Furthermore, by including different containment zones on the platen in some embodiments of the present technology, polishing patterns that are not limited to specific radial zones of the substrate can be produced. Because the substrate can rotate about a different axis than the platen, adjustments along the platen surface can affect unique and more complex patterns on the substrate.

[0019]

[0024] While the remainder of the disclosure will always identify specific polishing processes using the disclosed technology, it will be readily understood that the systems and methods are equally applicable to a variety of other chemical-mechanical polishing processes and systems. Accordingly, the present technology should not be considered limited to use with only the described polishing systems or processes. This disclosure will describe one possible system that can be used with the present technology before describing the systems and methods or steps of an exemplary process sequence according to some embodiments of the present technology. It should be understood that the present technology is not limited to the described equipment, and the described processes can be performed in any number of processing chambers and systems, with any number of variations, some of which are described below.

[0020]

[0025] FIG. 1 is a schematic cross-sectional view illustrating an exemplary polishing system 100 according to some embodiments of the present technique. The polishing system 100 includes a platen assembly 102 including a lower platen 104 and an upper platen 106. The lower platen 104 may define an interior region or cavity to which connections may be made and within which endpoint detection equipment or other sensors or devices, such as eddy current sensors, optical sensors, or other components for monitoring the polishing process or components, may be included. For example, as described further below, a fluid coupling may be formed with a line extending through the lower platen 104 and may access the upper platen 106 through the backside of the upper platen. The platen assembly 102 may include a polishing pad 110 attached to a first surface of the upper platen. A substrate carrier 108, or carrier head, may be positioned above and face the polishing pad 110. The platen assembly 102 may be rotatable about axis A, and the substrate carrier 108 may be rotatable about axis B. The substrate carrier may also be configured to sweep back and forth from the inner radius to the outer radius along the platen assembly, which may partially reduce uneven wear on the surface of the polishing pad 110. The polishing system 100 may also include a fluid supply arm 118 positioned above the polishing pad 110 and used to supply a polishing fluid, such as a polishing slurry, onto the polishing pad 110. Additionally, a pad conditioning assembly 120 may be positioned above the polishing pad 110 and may face the polishing pad 110.

[0021]

[0026] In some embodiments for performing a chemical mechanical polishing process, the rotating and / or sweeping substrate carrier 108 can apply a downward force to the substrate 112, which can be disposed within or coupled to the substrate carrier, as shown by the dotted line. The applied downward force can press the material surface of the substrate 112 against the polishing pad 110 as the polishing pad 110 rotates about the central axis of the platen assembly. The interaction of the substrate 112 with the polishing pad 110 can occur in the presence of one or more polishing liquids supplied by the fluid supply arm 118. Typical polishing liquids can include slurries formed of aqueous solutions in which abrasive particles can be suspended. Often, the polishing liquid includes other chemically active components, such as pH adjusters and oxidizers, which can enable chemical mechanical polishing of the material surface of the substrate 112.

[0022]

[0027] The pad conditioning assembly 120 is operable to apply a fixed, abrasive conditioning disk 122, which may rotate as described above, to the surface of the polishing pad 110. The conditioning disk may operate against the pad before, after, or during polishing of the substrate 112. Conditioning the polishing pad 110 using the conditioning disk 122 can maintain the polishing pad 110 in a desired condition by abrading and regenerating the polishing surface of the polishing pad 110 and removing polishing by-products and other debris from the polishing surface of the polishing pad 110. The upper platen 106 may be disposed on a mounting surface of the lower platen 104 and may be coupled to the lower platen 104 using a plurality of fasteners 138 that extend through an annular flange-shaped portion of the lower platen 104.

[0023]

[0028] The polishing platen assembly 102, and thus the upper platen 106, can be sized for any desired polishing system and for substrates of any diameter, including 200 mm, 300 mm, 450 mm, or larger. For example, a polishing platen assembly configured to polish a 300 mm diameter substrate can be characterized by a diameter greater than about 300 mm, such as from about 500 mm to about 1000 mm, or greater than about 500 mm. The platen diameter can be adjusted to accommodate substrates characterized by larger or smaller diameters, or for polishing platens 106 sized for simultaneous polishing of multiple substrates. The upper platen 106 can be characterized by a thickness of about 20 mm to about 150 mm and can be characterized by a thickness of about 100 mm or less, such as about 80 mm or less, about 60 mm or less, about 40 mm or less, or less. In some embodiments, the ratio of diameter to thickness of the polishing platen 106 may be about 3:1 or more, about 5:1 or more, about 10:1 or more, about 15:1 or more, about 20:1 or more, about 25:1 or more, about 30:1 or more, about 40:1 or more, about 50:1 or more, or more.

[0024]

[0029] The upper and / or lower platens may be formed of a suitably rigid, lightweight, and polishing fluid-corrosion-resistant material, such as aluminum, an aluminum alloy, or stainless steel, although any number of materials may be used. The polishing pad 110 may be formed of any number of materials, including polymeric materials such as polyurethane, polycarbonate, fluoropolymer, polytetrafluoroethylene polyphenylene sulfide, or combinations of any of these or other materials. Additional materials may be or include open-cell or closed-cell foamed polymers, elastomers, felt, impregnated felt, plastics, or other materials compatible with processing chemistries. The polishing system 100 is included to provide convenient reference to the components described below that may be incorporated into the system 100. However, it should be understood that the description of the polishing system 100 does not limit the present technology in any way, as embodiments of the present technology may be incorporated into any number of polishing systems that can benefit from the components and / or features described further below.

[0025]

[0030] 2A is a schematic, partial cross-sectional view illustrating an exemplary polishing assembly 200 according to some embodiments of the present technology. For example, the polishing assembly 200 may illustrate additional details regarding portions of the platen assembly 102 described above, and may include any components, features, or characteristics of that assembly or polishing system 100, as well as any other polishing system in which the polishing assembly 200 may be incorporated. It should be understood that the polishing assembly 200 is not drawn to any particular scale and is included merely to illustrate aspects of the present technology.

[0026]

[0031] As shown, the polishing assembly 200 may include an upper platen 205 that may be characterized by a first surface 207 and a second surface 209 opposite the first surface. The polishing assembly 200 may be incorporated into a polishing system in which the upper platen 205 may be coupled along the second surface 209 to a lower platen, such as the aforementioned lower platen 104, for example, along an outer region of the second surface of the upper platen 205. In some embodiments, the upper platen 205 may define a recess 210 in the second surface 209 of the upper platen 205. The recess may be formed in a region of the upper platen characterized by a reduced thickness, as shown. For example, the upper platen 205 may be characterized by a first cross-sectional thickness at one or more locations outside and / or inside the recess 210, such as any of the thicknesses described above with respect to the upper platen 106. Additionally, the upper platen 205 may be characterized by a second cross-sectional thickness along the portion of the upper platen 205 that defines the recess 210, which may be less than the first cross-sectional thickness.

[0027]

[0032] For example, the second cross-sectional thickness can be or include several thicknesses described further below, and can be about 15 mm or less, about 12 mm or less, about 10 mm or less, about 9 mm or less, about 8 mm or less, about 7 mm or less, about 6 mm or less, about 5 mm or less, about 4 mm or less, about 3 mm or less, about 2 mm or less, or less. Although a stainless steel upper platen can be characterized by a reduced thickness compared to aluminum, for example, in some embodiments, the second cross-sectional thickness can be about 0.5 mm or more, about 1.0 mm or more, about 1.5 mm or more, or more, allowing the cross-section to remain sufficiently rigid to withstand the downward force of the carrier head pressing the substrate down against the platen, as described further below.

[0028]

[0033] By maintaining a reduced thickness across at least a portion of the upper platen 205 in which the recess is defined, a flexure 215 can be formed within the upper platen between the first surface 207 and the second surface 209 along the recess of the upper platen 205. The polishing assembly 200 can include the polishing pad 220 described above, which can be coupled to the upper platen 205 along the first surface 207 of the upper platen. During operation, a substrate 222, held by, for example, the carrier head described above, can be pressed against the surface of the polishing pad opposite the surface coupled to the upper platen, as shown. Additionally, the polishing assembly 200 can include a plate 225 coupled to the upper platen along the second surface of the upper platen 205. The recess 210 can be or include a stepped recess, as shown, and the plate 225 can be coupled to the upper platen along a recess ledge 227 within the stepped recess. The plate 225 and upper platen 205 may define a region 230 within the recess of the upper platen. The region 230 may be defined between the recess of the upper platen and the plate 225, for example, in the area including the flexure 215. The plate 225 may be sealingly bonded to the upper platen, such as by welding, adhesive, or other bonding, or the plate may be removably bonded or fixed to the upper platen, as shown. One or more elastomeric elements 232 may be disposed or seated between the plate 225 and the second surface of the upper platen 205, which may ensure a fluid seal during processing or vacuum steps, as described below.

[0029]

[0034] The flexures 215, in some embodiments, can operate in a passive or active configuration, allowing the profile of the upper platen 205 and polishing pad 220 to adjust during operation. During passive operation, the substrate to be polished can be pressed down against the polishing pad by the carrier head with a certain amount of force. This force can be applied to compress the flexures 215 into a downwardly sloped concave shape, which can adjust the profile of the polishing pad when it impacts material on the surface of the substrate. The amount of bending of the flexures 215 can be controlled by the downward pressure applied by the carrier head. Because the localized force applied to the flexure can be limited to an area near the carrier head, as the platen rotates, a unique contact action occurs at the leading and trailing edges of the flexure, causing the flexure to begin to press down at the leading edge and return to a more planar configuration at the trailing edge.

[0030]

[0035] Additionally, the flexure 215 may actively operate in conjunction with additional components of the polishing assembly. For example, as shown in FIG. 2A , a pneumatic pump 235 may be coupled to a region 230 formed adjacent to the flexure 215. Fluid lines 237 or ports may be mounted, seated, or otherwise coupled within the plate 225 to provide fluid access to the region 230. The pneumatic pump 235 may create a vacuum within the region 230, which may create a concave profile along the flexure that may be more easily controlled than by the downward force of the carrier head. Additionally, the pneumatic pump 235 may operate to increase pressure within the region 230 by supplying air or some other fluid from a fluid source 239 into the region 230, which may create a convex profile along the flexure 215. One or more stops or protrusions 240 may extend from the plate 225 toward the upper platen 205 within the region to limit the amount of flexure during passive or active operation. The protrusion may be sized to define the maximum bending distance of the flexure. The protrusion may be characterized by an annular shape and may extend in a ring shape around plate 225 as shown, or may be any size or shape, as further described below. The protrusion may be part of plate 225 in some embodiments, or may be bonded or adhered to the plate.

[0031]

[0036] 2A, in some embodiments, the recess 210, as well as the region 230 and the plate 225, may be characterized by an annular shape centered on the central axis 245 of the polishing assembly 200. The recess may be formed to any radial length, which may be larger or smaller than the diameter of the substrate being processed. For example, the recess may be characterized by a radial length of about 10% or more of the diameter of the substrate being processed, about 25% or more of the diameter of the substrate being processed, about 50% or more of the diameter of the substrate being processed, about 75% or more of the diameter of the substrate being processed, about 90% or more of the diameter of the substrate being processed, about 100% or more of the diameter of the substrate being processed, about 110% or more of the diameter of the substrate being processed, about 120% or more of the diameter of the substrate being processed, or more.

[0032]

[0037] Furthermore, as shown in FIG. 2B , polishing assemblies according to some embodiments of the present technology may be characterized by circular or elliptical regions. For example, as shown, polishing assembly 250 may represent a variation of polishing assembly 200 of FIG. 2A , and polishing assembly 250 may include any of the components, features, or characteristics described above. As shown, polishing assembly 250 includes similar features to polishing assembly 200, but recess 260 may extend across the central axis of upper platen 255 along a diameter smaller than the outer diameter of upper platen 205. Accordingly, flexures 265 formed along the upper platen, or the reduced second cross-sectional thickness of the platen, may vary to form a slope, concave profile, or convex profile across the central axis of the upper platen. Plate 270 may similarly be formed as a circular or elliptical component and may be seated within or otherwise coupled to upper platen 255 to form region 275, as previously described. The use of elliptical, circular, or annular regions can provide many variations in accordance with embodiments of the present technology for polishing semiconductor substrates. Furthermore, when a region extends continuously across the central axis of the polishing assembly, the diameter of the region can extend by any percentage of the diameter of the substrate being polished, as described above, and can be two or three times any of the percentages described above.

[0033]

[0038] Reference is now made to FIG. 3 , which is a schematic, partial cross-sectional view illustrating an exemplary polishing assembly 300 according to some embodiments of the present technology. The polishing assembly 300 may depict aspects of any of the polishing assemblies described above, and may illustrate additional features of polishing assemblies according to embodiments of the present technology. For example, the polishing assembly 300 may depict additional details of features of the polishing system 100, or the polishing assemblies 200 or 250, as described above, and may be included with any other features or structures described in this disclosure. While the polishing assembly 300 depicts an annular-type region formed in the assembly, it should be understood that any aspect of the polishing assembly 300 may be incorporated with any of the structures described above, and the polishing assembly 300 does not limit the present technology to the specific configuration as shown.

[0034]

[0039] The polishing assembly 300 may include any of the features described above with respect to any polishing assembly or system and is shown only in a partial view to illustrate certain features of the structure. For example, the polishing assembly 300 may include an upper platen 305, which may be characterized by a first surface 307 and a second surface 309 opposite the first surface. As described above, a recess 310 may be defined in the second surface 309, which may define a flexure 315. As described above, the polishing pad 320 may be coupled to the first surface 307 of the polishing assembly, and the plate 325 may be coupled to the second surface 309. As described above, a region 330 may be defined between the plate 325 and the recess in the second surface of the upper platen. Similarly, the pneumatic pump 335 may be fluidly coupled to the region with a fluid line 337, as described above, and may access the region through the plate 325, for example, at a port defined in the plate 325.

[0035]

[0040] As shown in the polishing assembly 300, assemblies according to some embodiments of the present technology may include features for accommodating flexures, including protrusions 340 or hard stops that can define the inward bending distance of the flexure 315, as previously described. As shown, in some embodiments of the present technology, the protrusions may be shaped to adjust or control the bending of the flexure. For example, to limit indentation or control the bending profile, the protrusions 340 may be characterized by any number of shapes or profiles. For example, protrusions 340a and 340c extending outward from the center of the flexure may be characterized by a first height. Furthermore, protrusion 340b, which may be located axially in line with the maximum bending position, may be characterized by a second height different from the first height, such as being lower than the first height. Including stops of different heights can more evenly distribute stress on the flexure during bending.

[0036]

[0041] Additionally, in some embodiments, any of the flexures may be characterized by a sloped, curved, or chamfered profile, as shown in protrusion 340a, and any or all of the protrusions may include rounded edges, as shown in protrusion 340c. Adjusting the top profile of the protrusions and limiting any sharp corners can, for example, protect the flexure 315 and control stresses during operation. Because the protrusions 340 are not exposed to abrasive slurries or other processing environmental conditions, the protrusions can be formed from any number of materials, including metals similar to platens or plates, as well as other materials, including any polymers, plastics, rubbers, or combinations of materials, that can support and protect the flexure when in contact with it.

[0037]

[0042] Additionally, in some embodiments, the polishing assembly interior region 330, including any of the polishing assemblies described elsewhere, can include one or more dividers 345 that can provide multiple interior zones within the region defined within the upper platen. The dividers can be or include a flexible material that can be formed as partition walls extending from the plate 325 to the second surface 309 of the upper platen within a recess to mate with the underside of the flexure 315 as shown. The dividers 345 can fluidly isolate adjacent interior zones within the region, thereby enabling multiple benefits to be applied in some embodiments of the present technology.

[0038]

[0043] For example, in some embodiments, the pneumatic pump 335 may include a first fluid line 337a extending to the first internal zone 350a and a second fluid line 337b extending to the second internal zone 350b. While only two couplings are illustrated, it should be understood that any number of internal zones and / or fluid couplings may be incorporated into a polishing assembly according to embodiments of the present technology, and any number of partitions 345 may be included to form the zones. Because the partition 345b may fluidly isolate the first internal zone 350a from the second internal zone 350b, the pneumatic pump 335 may pressurize and / or purge the two zones separately. Thus, the zones may be pressurized and / or purged to different degrees, or one or more zones may be pressurized and one or more separate zones may be purged according to embodiments of the present technology. As a result, configurations encompassed by the present technology may be formed to produce a gentle slope or curve, an M-shape, a W-shape, or other waveforms, depending on the number of independent zones incorporated. As a result, a variety of unique polishing surfaces can be created and applied to the material being polished on the semiconductor substrate.

[0039]

[0044] Divider 345 may be or include any number of materials or shapes, including metal, polymer, rubber, or any of the materials previously described, including other materials that can be bonded between the plate and the upper platen and can withstand pressure or vacuum applied within the region. The material may be included in many ways, including a bellows configuration, as shown by divider 345a, as well as compressible or expandable compliant walls, as shown by divider 345b. Any number of other profiles may be used to accommodate the amount of deflection intended within any interior zone of the assembly.

[0040]

[0045] 4 is a schematic, partial cross-sectional view illustrating an exemplary polishing assembly according to some embodiments of the present technology. The polishing assembly 400 may represent any of the aspects of the polishing assemblies described above, and may illustrate additional features of polishing assemblies according to embodiments of the present technology. For example, the polishing assembly 400 may further detail the features of the polishing system 100, or the polishing assemblies 200 or 250, as described above, and may include any other features or structures described in this disclosure. Like the polishing assembly 300, the polishing assembly 400 depicts an annular-type region formed in the assembly, but it should be understood that any aspect of the polishing assembly 400 may incorporate any of the aforementioned structures, and the polishing assembly 400 is not intended to limit the present technology to the specific configuration shown.

[0041]

[0046] The polishing assembly 400 may include any of the features previously described with respect to any polishing assembly or system and is shown only in a partial view to illustrate certain features of the structure. For example, the polishing assembly 400 may include an upper platen 405 during operation of the flexure 410 and may include any of the features or characteristics of any of the polishing assemblies previously described. A vacuum can be applied to the region as shown, which draws the flexure toward the protrusion 415. While this description is based on a vacuum being applied, the region can also be pressurized to create the opposite effect, forming a convex shape as shown by the dotted line 420.

[0042]

[0047] In embodiments according to the present technology, the flexures may be characterized by a stiffness that provides controlled deformation based on pressure or vacuum applied to an interior zone or region. For example, in some embodiments, the flexures 410, or any flexures described elsewhere, may be characterized by a stiffness of about 0.10 mm / kPa or less, which may be highly stiff, about 0.05 mm / kPa or less, about 0.01 mm / kPa or less, about 0.005 mm / kPa or less, about 0.001 mm / kPa or less, or even less. Additionally, the flexures may be shaped, or the protrusions positioned and sized, to provide a maximum available deflection of about 1.0 mm or less, and also about 0.75 mm or less, about 0.70 mm or less, about 0.65 mm or less, about 0.60 mm or less, about 0.55 mm or less, about 0.50 mm or less, about 0.45 mm or less, about 0.40 mm or less, about 0.35 mm or less, about 0.30 mm or less, about 0.25 mm or less, about 0.20 mm or less, about 0.15 mm or less, about 0.10 mm or less, or less. Thus, by applying pressure or vacuum to the zones in a controlled manner, fine tuning of the flexure of the flexure may be possible in one or more zones within the region.

[0043]

[0048] 5A-5B are schematic, partial cross-sectional views illustrating an exemplary polishing assembly according to some embodiments of the present technology, which may illustrate further details of flexures according to some embodiments of the present technology. The flexures illustrated and described with respect to the figures may be incorporated into any polishing assembly described elsewhere, including any of the polishing assemblies previously described. As illustrated, in some embodiments, the flexures may be characterized by a cross-sectional thickness that varies throughout the flexure. For example, as shown in FIG. 5A, flexure 505 may be characterized by a tapered thickness throughout the flexure. While illustrated as extending in one direction, in embodiments, the taper may extend in the opposite direction, or may extend toward the center of the flexure before thickening again. Adjusting the thickness of the flexure at one or more locations or throughout the area of ​​the flexure can alter bending characteristics. For example, in the example shown in FIG. 5A, the taper may shift the location of maximum bending from the center point of the flexure toward the end of the taper. In embodiments, one or more stops 510 may be adjusted to accommodate offset bending.

[0044]

[0049] Additionally, as shown in FIG. 5B, the flexure 520 may be characterized by a tapered shape toward the center of the flexure. Varying the width may provide additional support at high stress or bond locations in the flexure. It should be understood that the exemplary configurations shown in FIGS. 5A and 5B are merely examples, and that any number of variations and modifications are encompassed by the present technology. The variance within the flexure from maximum to minimum cross-sectional thickness may be about 5.0 mm or less, about 4.5 mm or less, about 4.0 mm or less, about 3.5 mm or less, about 3.0 mm or less, about 2.5 mm or less, about 2.0 mm or less, about 1.5 mm or less, about 1.0 mm or less, about 0.5 mm or less, or less, in embodiments consistent with the present technology.

[0045]

[0050] The polishing assembly according to the embodiments of the present technology described above can be used in a chemical mechanical polishing process. FIG. 6 illustrates selected steps in a method 600 of semiconductor processing according to some embodiments of the present technology. Method 600 may include one or more steps prior to the start of the described method steps, including semiconductor processing to form one or more layers of material on the substrate and clamping the substrate to a carrier head of a polishing system as described above. A polishing slurry may be applied to the polishing pad, and the carrier head may be positioned to press the substrate down against the polishing pad. In some embodiments, before or during application of the carrier head to the polishing pad, pressure or vacuum may be applied to a region within the upper platen, as described above, in step 605, which may cause the flexure to deform in response to the pressure. The pressure may be adjusted in one or more interior zones of the region, which may result in any of a variety of flexure shapes, as described above. The resulting shape of the specifically configured flexure may then be used to polish the substrate in step 610. In some embodiments, a pneumatic pump may not be used, and the flexure may be passively utilized by bending due to pressure from the carrier head and / or substrate. By using flexures according to embodiments of the present technology, more complex polishing processes can be performed by using additional adjustment mechanisms to contact the substrate being polished.

[0046]

[0051] In the above 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.

[0047]

[0052] While several embodiments have been disclosed, those skilled in the art will recognize that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. Moreover, in order to avoid unnecessarily obscuring the technology, many well-known processes and elements have not been described. Therefore, the above description should not be deemed to limit the scope of the technology.

[0048]

[0053] Where a range of values ​​is provided, it is understood that each intervening value, to the smallest fraction of the unit of the lower limit, between the upper and lower limit of that range is also specifically disclosed, unless the context clearly dictates otherwise. Any narrower range between any stated value or unstated intervening value in a stated range and any other stated or intervening value in that stated range is also included. The upper and lower limits of these smaller ranges may independently be included or excluded, and each range in which either or both limits are included in the smaller ranges is also included within the technology, subject to any specifically excluded limits in the stated range. Where a stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.

[0049]

[0054] As used in this specification and 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 flexure" includes a plurality of such flexures, reference to "the protrusion" includes a reference to one or more protrusions and equivalents thereof known to those skilled in the art, and so forth.

[0050]

[0055] Also, as used in this specification and the claims that follow, the terms "comprise," "comprising," "contain," "containing," "include," and "including" specify the presence of stated features, integers, components, or steps, but do not exclude the presence or addition of one or more other features, integers, components, steps, operations, or groups.

Claims

1. 1. A polishing assembly comprising: an upper platen characterized by a first surface and a second surface opposite the first surface, defining a recess in the second surface of the upper platen, the recess forming an area of ​​reduced thickness of the upper platen; an upper platen, the area of ​​reduced thickness of the upper platen forming a flexure within the recess between the first surface and the second surface; a polishing pad seated on and bonded to the first surface of the upper platen; a plate coupled to the upper platen along the second surface thereof, the plate defining an area within the recess of the upper platen between the second surface of the upper platen and the plate; 1. A polishing assembly comprising:

2. The polishing assembly of claim 1 , wherein the recess defined in the second surface of the upper platen includes an annular recess defined proximate the upper platen.

3. A polishing assembly as described in claim 1, wherein the plate is coupled to the upper platen along a recess ledge within the recess, and the area defined within the recess of the upper platen is sealed with an elastomeric element positioned between the plate and the second surface of the upper platen.

4. The polishing assembly of claim 1 , wherein one or more stops extend from the plate toward the flexure of the upper platen and define a maximum bending distance of the flexure defined by the upper platen.

5. 5. The polishing assembly of claim 4, wherein the one or more stops include a plurality of stops, a first stop of the plurality of stops being characterized by a different height than a second stop of the plurality of stops.

6. a pneumatic pump fluidly coupled to an area within the recess of the upper platen, a fluid line from the pneumatic pump being coupled to the plate; The polishing assembly of claim 1 further comprising:

7. a compliant wall extending within the recess from the plate to a second surface of the upper platen, the compliant wall dividing an area within the recess of the upper platen into a first zone and a second zone, the first zone being fluidly isolated from the second zone. The polishing assembly of claim 6 further comprising:

8. 8. The polishing assembly of claim 7, wherein the pneumatic pump includes a first fluid line extending to the first zone and a second fluid line extending to the second zone, and is operable to pump or purge each of the first zone and the second zone separately.

9. The abrasive assembly of claim 1 , wherein the flexure is characterized by a cross-sectional thickness that varies throughout the flexure.

10. 1. A polishing assembly comprising: an upper platen characterized by a first surface and a second surface opposite the first surface, the upper platen comprising: defining a recess in the second surface of the upper platen; characterized by a first cross-sectional thickness outside the recess; characterized by a second cross-sectional thickness along the portion defining the recess; an upper platen, the second cross-sectional thickness being less than the first cross-sectional thickness and forming a flexure between the first surface and the second surface; a polishing pad seated on and bonded to the first surface of the upper platen; a plate coupled to the upper platen along the second surface thereof, the plate defining an area within the recess of the upper platen between the second surface of the upper platen and the plate; 1. A polishing assembly comprising:

11. The abrasive assembly of claim 10 , wherein the second cross-sectional thickness is characterized by a thickness of about 15 mm or less.

12. The polishing assembly of claim 10 , wherein the portion of the upper platen characterized by the second cross-sectional thickness of the upper platen lies transverse to a central axis of the upper platen.

13. 11. The polishing assembly of claim 10, wherein one or more protrusions extend from the plate toward the upper platen, each protrusion of the one or more protrusions characterized by an annular shape adjacent the plate.

14. a pneumatic pump fluidly coupled to an area within the recess of the upper platen, a fluid line from the pneumatic pump being coupled to the plate; The polishing assembly of claim 10 further comprising:

15. a bellows extending from the plate through the region to a second surface of the upper platen, the bellows dividing the region within the recess of the upper platen into a first zone and a second zone, the first zone being fluidly isolated from the second zone. The polishing assembly of claim 14 further comprising:

16. 16. The polishing assembly of claim 15, wherein the pneumatic pump includes a first fluid line extending to the first zone and a second fluid line extending to the second zone, and the pneumatic pump is operable to separately pump to or purge from each of the first zone and the second zone.

17. 1. A polishing assembly comprising: an upper platen characterized by a first surface and a second surface opposite the first surface, defining a recess in the second surface of the upper platen, the recess forming an area of ​​reduced thickness of the upper platen; an upper platen, the area of ​​reduced thickness of the upper platen forming a flexure within the recess between the first surface and the second surface; a polishing pad seated on and bonded to the first surface of the upper platen; a plate coupled to the upper platen along the second surface thereof, the plate defining an area within the recess of the upper platen between the second surface of the upper platen and the plate; a pneumatic pump fluidly coupled to the region within the recess of the upper platen, a fluid line from the pneumatic pump providing fluid access to the region; 1. A polishing assembly comprising:

18. 20. The polishing assembly of claim 17, wherein the flexure is characterized by a cross-sectional area that varies throughout the flexure.

19. a compliant wall extending from the plate through the region to the second surface of the upper platen, dividing the region within the recess of the upper platen into a first zone and a second zone, the first zone being fluidly isolated from the second zone; the pneumatic pump including a first fluid line extending to the first zone and a second fluid line extending to the second zone, the pneumatic pump operable to separately pump or purge each of the first zone and the second zone; The polishing assembly of claim 17 further comprising:

20. 18. The polishing assembly of claim 17, wherein one or more protrusions extend from the plate toward the upper platen and define a maximum inward deflection distance of the flexures.

Images