Face-up type wafer edge polishing machine

Abstract

An exemplary substrate edge polishing apparatus may include a chuck body defining a substrate support surface. The apparatus may include an edge ring seated on the chuck body. The apparatus may include a retaining wall disposed radially outward of the edge ring. The apparatus may include a slurry supply port disposed radially inward of the retaining wall. The apparatus may include a cylindrical spindle positionable on the chuck body. The apparatus may include an annular polishing pad coupled to a lower end of the cylindrical spindle.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. patent application Ser. No. 17 / 380,788, entitled "FACE-UP WAFER EDGE POLISHING APPARATUS," filed on July 20, 2021, the entire contents of which are incorporated herein by reference.

[0002]

[0002] The present technology relates to semiconductor systems, processes, and equipment. More particularly, the present technology relates to polishing films deposited on substrates. [Background technology]

[0003]

[0003] Integrated circuits are typically formed on a substrate by sequentially depositing conductive, semiconducting, and / or insulating layers on a silicon wafer. Various manufacturing processes use planarization of layers on the substrate between processing steps. For example, in certain applications, such as polishing a metal layer to form vias, plugs, and / or lines within trenches in a patterned layer, the layer above is planarized until the top surface of the patterned layer is exposed. In other applications, such as planarizing a dielectric layer for photolithography, the upper layer is polished until a desired thickness remains above the underlying layer.

[0004] Chemical mechanical polishing (CMP) is a common method of planarization. This planarization 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 polishing pad. The carrier head applies a controllable load to the substrate, pressing it against the polishing pad. An abrasive slurry is typically supplied to the surface of the polishing pad.

[0005] One problem in CMP is achieving uniform polishing across the entire surface of a substrate. The design of CMP systems often results in deflection in the area near the periphery of the polishing pad, which causes uneven polishing. As a result, the film thickness at the edge of the substrate is often thicker than in the center of the substrate. This film non-uniformity can cause lithographic problems and potentially lead to a loss of die yield from a given substrate.

[0006]

[0006] Therefore, there is a need for improved systems and methods that can be used to polish substrates to produce uniform films across the entire surface area of ​​the substrate. These and other needs are addressed by the present technology. Summary of the Invention

[0007] An exemplary substrate edge polishing apparatus may include a chuck body defining a substrate support surface. The apparatus may include an edge ring seated on the chuck body. The apparatus may include a retaining wall disposed radially outward from the edge ring. The apparatus may include a slurry supply port disposed radially inward from the retaining wall. The apparatus may include a spindle positionable on the chuck body. The apparatus may include an annular polishing pad coupled to a lower end of the spindle.

[0008] In some embodiments, the inner diameter of the annular polishing pad may be smaller than the inner diameter of the edge ring. The spindle may be rotatable and laterally translatable relative to the chuck body. The height of the upper surface of the edge ring may be within about 10 microns of the height of a substrate disposed on the substrate support surface. The apparatus may include a slurry exhaust port disposed inside one or both of the chuck body and the retaining wall. The outer edge of the edge ring may be disposed against the inner surface of the retaining wall. The edge ring may be removably coupled to the chuck body.

[0009] Some embodiments of the present technique may include a substrate edge polishing apparatus. The apparatus may include a chuck body defining a substrate support surface. The apparatus may include an edge ring seated on the chuck body. The edge ring may have an inner diameter that is less than about 5% larger than the diameter of the substrate support surface. The apparatus may include a spindle positionable on the chuck body. The apparatus may include a rotary drive mechanism coupled to the spindle. The apparatus may include an annular polishing pad coupled to a lower end of the spindle.

[0010] In some embodiments, the annular polishing pad may include a CMP polishing pad or a polishing disk. The top surface of the edge ring may taper toward the outer periphery of the edge ring. The bottom surface of the annular polishing pad may taper toward the outer periphery of the annular polishing pad. The chuck body may include an electrostatic chuck or a vacuum chuck. The apparatus may include a retaining wall disposed radially outward of the edge ring. The apparatus may include a polishing slurry source. The apparatus may include a slurry supply port fluidly coupled to the polishing slurry source. The slurry supply port may be disposed radially inward of the retaining wall. The top surface of the substrate support surface may be concave or convex. The substrate edge polishing apparatus may be disposed in a polishing chamber including a face-down polishing station.

[0011] Some embodiments of the present technique may include a method for polishing a substrate. The method may include placing the substrate face-up within an open interior of an edge ring disposed over a substrate support surface of a chuck body. The method may include clamping the substrate to the chuck body. The method may include engaging an upper surface of the substrate with an annular polishing pad. The method may include rotating the annular polishing pad against the upper surface of the substrate.

[0012] In some embodiments, the method may include laterally translating the annular polishing pad while rotating the annular polishing pad against the upper surface of the substrate. The method may include supplying a polishing slurry to the upper surface of the substrate. The method may include applying a downward force to the annular polishing pad while rotating the annular polishing pad against the upper surface of the substrate. While rotating the annular polishing pad against the upper surface of the substrate, a central axis of the annular polishing pad may be offset from a central axis of the substrate. The method may include resurfacing the surface of the annular polishing pad.

[0013] The above techniques may provide numerous advantages over conventional systems and techniques. For example, the edge polishing apparatus described herein may enable targeting of the edge region of a substrate during the polishing process. In many cases, the edge polishing techniques described herein may be used before and / or after a conventional CMP process. This may improve film thickness uniformity across the surface of the substrate, which may result in improved die yield. These and other embodiments, along with their many advantages and features, are described in more detail below in conjunction with the description and accompanying figures.

[0014] 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]

[0015] [Figure 1] 1 is a schematic cross-sectional view illustrating an exemplary polishing system according to some embodiments of the present technique. [Figure 2] 1 is a schematic partial cross-sectional view illustrating an exemplary edge processing device according to some embodiments of the present technology; [Figure 3] 1 is a schematic partial cross-sectional view illustrating an exemplary edge processing device according to some embodiments of the present technology; [Figure 4] 1 is a schematic partial cross-sectional view illustrating an exemplary refinishing station according to some embodiments of the present technique; [Figure 5]1 is a schematic partial top plan view illustrating an exemplary polishing chamber according to some embodiments of the present technique; [Figure 6] 1 is a flowchart of an exemplary method for polishing a substrate in accordance with some embodiments of the present technique. DETAILED DESCRIPTION OF THE INVENTION

[0016]

[0021] 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.

[0017]

[0022] 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.

[0018]

[0023] In conventional chemical mechanical polishing (CMP) processes, it is often difficult to uniformly polish the surface of a substrate. In conventional CMP polishing, a substrate is placed face-down on a polishing pad using a carrier that holds the substrate in contact with the rotating polishing pad. However, the polishing pad often flexes near the edge of the substrate, which can result in high film thickness remaining in the edge region of the substrate. These issues can lead to non-uniformity problems that reduce die yield.

[0019]

[0024] The present technology overcomes these problems in conventional polishing systems by providing an edge polishing apparatus that can be used to polish films within the edge region of a substrate. Embodiments can provide face-up polishing techniques that allow an annular-shaped polishing pad to selectively polish the edge region of a wafer. These techniques can be used in combination with conventional CMP systems to produce substrates with improved film thickness uniformity. Furthermore, embodiments can include a chuck mechanism that can help planarize the substrate during polishing, further improving the uniformity achieved during the polishing process. Embodiments can enable the polishing pad to translate laterally relative to the substrate, which can enable the edge polishing apparatus to address asymmetric uniformity issues.

[0020]

[0025] While the remainder of the disclosure will always identify specific film polishing processes utilizing the disclosed technology, it will be readily understood that the systems and methods are equally applicable to a variety of other semiconductor processing steps and systems. Accordingly, the present technology should not be considered limited to use solely with the described polishing systems or polishing 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 modifications, some of which are described below.

[0021]

[0026] 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 through which connections can be made and may include 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. For example, as described further below, a fluid coupling may be formed using 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 the polishing pad 110 and may 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 along the platen assembly from the inner radius to the outer radius, which may, in part, reduce uneven wear on the surface of the polishing pad 110. The polishing system 100 may also include a fluid delivery arm 118 that is positioned above the polishing pad 110 and may be used to deliver 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.

[0022]

[0027] In some embodiments for performing a chemical mechanical polishing process, the rotating and / or sweeping substrate carrier 108 can exert a downward force on the substrate 112, shown in dotted lines and which can be disposed within or coupled to the substrate carrier. The downward force can cause the material surface of the substrate 112 to be pressed down 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 a fluid delivery arm 118. Typical polishing liquids can include a slurry formed of an aqueous solution 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.

[0023]

[0028] The pad conditioning assembly 120 can be operated to apply a fixed, abrasive conditioning disk 122 to the surface of the polishing pad 110, which can be rotated as described above. The conditioning disk can be operated against the pad before, after, or during polishing of the substrate 112. Conditioning the polishing pad 110 with the conditioning disk 122 can maintain the polishing pad 110 in a desired condition by abrading, regenerating, and removing polishing by-products and other debris from the polishing surface of the polishing pad 110. The upper platen 106 can be disposed on a mounting surface of the lower platen 104 and can be coupled to the lower platen 104 using, for example, a plurality of fasteners 138 extending through an annular flange-shaped portion of the lower platen 104.

[0024]

[0029] The polishing platen assembly 102, and thus the upper platen 106, can be sized to suit any desired polishing system and can be sized to accommodate 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, e.g., 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, e.g., 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.

[0025]

[0030] The upper and / or lower platens may be formed of a suitable rigid, lightweight, and polishing fluid-resistant material, such as aluminum, 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 any combination of these or other materials. Additional materials may be or include open-cell or closed-cell foamed polymers, elastomers, felt, impregnated felt, plastic, or any other material compatible with processing chemicals. 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.

[0026]

[0031] FIG. 2 is a schematic cross-sectional view of an exemplary edge polishing apparatus 200 according to some embodiments of the present technique. The apparatus 200 can be used to perform an edge polishing process. The apparatus 200 may represent a partial view of components that may be incorporated into an illustrated semiconductor processing system. The apparatus 200 may include a substrate support 205. The substrate support 205 can receive and support a substrate 210 during one or more processing steps. In some embodiments, the substrate support 205 can include a chuck body 215 that can define a substrate support surface 217. The chuck body 215 can include associated channels or components for operating as a vacuum chuck, an electrostatic chuck, and / or any other type of chuck system. For example, the chuck body 215 can define multiple channels 220 coupled to a vacuum source 225. The vacuum source 225 can generate a negative pressure within the channels 220 to clamp the substrate 210 to the chuck body.

[0027]

[0032] In other embodiments, the chuck body 215 may comprise an electrostatic chuck. In the above embodiments, the chuck body 215 may include associated channels or components for operating as an electrostatic chuck. For example, the electrostatic chuck body 215 may be formed from a conductive material (such as a metal such as aluminum, or any other material that may be thermally and / or electrically conductive) and may be coupled to a power source (such as DC power, pulsed DC power, RF bias power, pulsed RF source or bias power, or a combination of these or other power sources) through a filter, which may be an impedance matching circuit, to enable the electrostatic chuck body 215 to operate as an electrode. In other embodiments, the top of the electrostatic chuck body 215 may be formed from a dielectric material. In the above embodiments, the electrostatic chuck body 215 may include separate electrodes that may be embedded within the chuck body 215 proximate the substrate support surface. Each electrode may be electrically coupled to a DC power source that provides energy or voltage to the electrode. During operation, the substrate 210 may be in at least partial contact with the substrate support surface of the chuck body, which may create a contact gap and an inherent capacitive effect between the surface of the pedestal and the substrate, and a voltage may be applied across the contact gap to generate an electrostatic force for chucking.

[0028]

[0033] An edge ring 230 may be seated on the chuck body 215. For example, the edge ring 230 may be disposed around the substrate support surface 217 such that the substrate 210 is disposed within the open interior of the edge ring 230. The edge ring 230 may help maintain the substrate 210 in a desired position and may help prevent significant deformation of the polishing pad if the polishing pad moves beyond the outer periphery of the substrate 210. The inner diameter of the edge ring 230 may be no more than about 5% larger than the diameter of the substrate 210, no more than about 4% larger than the diameter of the substrate 210, no more than about 3% larger than the diameter of the substrate 210, no more than about 2% larger than the diameter of the substrate 210, no more than about 1% larger than the diameter of the substrate 210, no more than about 0.5% larger than the diameter of the substrate 210, or smaller. For example, for a substrate 210 having a diameter of 300 mm, the edge ring 230 may have an inner diameter ranging from at least 300 mm to about 315 mm, but often from about 300.5 mm to about 305 mm. The thickness of the edge ring 230 may substantially match the thickness of the substrate 210. For example, the thickness of the edge ring 230 may be within about 3% of the thickness of the substrate 210, within about 2% of the thickness of the substrate 210, within about 1% of the thickness of the substrate 210, within about 0.5% of the thickness of the substrate 210, or less. For example, for a substrate 210 having a thickness of 1 mm, the thickness of the edge ring 230 may be about 0.970 mm to 1.030 mm, about 0.980 mm to 1.020 mm, about 0.990 mm to 1.010 mm, about 0.995 mm to 1.005 mm, or about 1 mm. In some embodiments, the top surface of the chuck body 215 on which the edge ring 230 sits can be raised or lowered. In the above embodiments, the thickness of the edge ring 230 can be adjusted so that the top surface of the edge ring 230 is within about 3% of the height of the top surface of the substrate 210, within about 2% of the height of the top surface, within about 1% of the height of the top surface, within about 0.5% of the height of the top surface, or less.

[0029]

[0034] The edge ring 230 may be removably coupled to the chuck body 215. For example, one or more clamps, fasteners, and / or other coupling mechanisms may be used to secure the edge ring 230 to the top surface of the chuck body 215. This may allow the edge ring 230 to be removed for repair, cleaning, and / or replacement. For example, after several polishing processes, the top surface of the edge ring 230 may be polished to a low height. The edge ring 230 may be replaced to prevent it from affecting subsequent polishing processes.

[0030]

[0035] The apparatus 200 may include a spindle 235 positionable on the chuck body 215. While shown herein as having a hollow cylindrical body, the spindle 235 may be formed of other shapes and / or may be solid in various embodiments. The spindle 235 may be rotatable and translatable vertically and / or horizontally relative to the chuck body 215. For example, the spindle 235 may be coupled to one or more motors and / or other drive mechanisms 240 that may drive the rotation and / or translation of the spindle 235. The bottom end of the spindle 235 may include a polishing pad 245. The polishing pad 245 may be removably coupled to the bottom end of the spindle 235, which may allow the polishing pad 245 to be refinished, cleaned, and / or replaced as needed. For example, the polishing pad 245 may be coupled to the bottom end of the spindle 235 using an adhesive (such as a pressure-sensitive adhesive), a snap connector, a hook-and-loop connector, and / or other coupling mechanisms that may allow the polishing pad 245 to be removably coupled to the spindle 235.

[0031]

[0036] The polishing pad 245 may be a standard CMP polishing pad (which may be used with a polishing slurry) and / or may be an abrasive disk, such as a grindstone, that may be used without any slurry. The polishing pad 245 may have an annular shape sized to polish only the peripheral region of the substrate 210. For example, the inner diameter of the polishing pad 245 may be smaller than the diameter of the substrate 210 (smaller than the inner diameter of the edge ring 230), and the outer diameter of the polishing pad 245 may be larger than the diameter of the substrate 210. For example, the inner diameter of the polishing pad 245 can be about 90% or less of the diameter of the substrate 210, about 91% or less of the diameter of the substrate 210, about 92% or less of the diameter of the substrate 210, about 93% or less of the diameter of the substrate 210, about 94% or less of the diameter of the substrate 210, about 95% or less of the diameter of the substrate 210, about 96% or less of the diameter of the substrate 210, about 97% or less of the diameter of the substrate 210, about 98% or less of the diameter of the substrate 210, or about 99% or less of the diameter of the substrate 210. For example, for a 300 mm substrate 210, the inner diameter of the polishing pad 245 can be about 270 mm to 297 mm, about 273 mm to 294 mm, about 276 mm to 291 mm, about 279 mm to 288 mm, or about 282 mm to 285 mm. The outer diameter of the polishing pad 245 may be about 100% or more of the diameter of the substrate 210, about 101% or more of the diameter of the substrate 210, about 102% or more of the diameter of the substrate 210, about 103% or more of the diameter of the substrate 210, about 104% or more of the diameter of the substrate 210, about 105% or more of the diameter of the substrate 210, about 106% or more of the diameter of the substrate 210, about 107% or more of the diameter of the substrate 210, about 108% or more of the diameter of the substrate 210, about 109% or more of the diameter of the substrate 210, about 110% or more of the diameter of the substrate 210, or more. For example, for a 300 mm substrate 210, the outer diameter of the polishing pad 245 may be about 300 mm to 330 mm, about 303 mm to 327 mm, about 306 mm to 324 mm, about 309 mm to 321 mm, about 312 mm to 318 mm, or about 315 mm. Such sizing may allow for polishing of the entire edge region of the substrate 210, or may allow for asymmetric polishing of only a portion of the edge region of the substrate 210 if the spindle 235 and polishing pad 245 are translated off-axis laterally from the center of the substrate 210.

[0032]

[0037] In some embodiments, such as those in which the polishing pad 245 is a CMP polishing pad, the apparatus 200 may include a slurry supply conduit 255. The slurry supply port 255 may be coupled to a slurry source 250 and may supply a slurry from the slurry source 250 to the surface of the substrate 210 during the polishing process. The slurry may include an aqueous solution in which abrasive particles may be suspended. To prevent the slurry from spreading away from the substrate 210, the apparatus 200 may include a retaining wall 260. The retaining wall 260 may be positioned radially outward of both the edge ring 230 and the slurry supply port 255 so that the slurry supplied to the substrate 210 through the slurry supply port 255 is maintained in close proximity to the substrate 210. While the slurry supply port 255 is shown positioned above the retaining wall 260, in some embodiments, the slurry supply port 255 may extend through a portion of the retaining wall 260 and / or the chuck body 215. To minimize the amount of slurry required for a given polishing process, the inner surface of the retaining wall 260 may be positioned proximate to and may even contact the outer surface of the edge ring 230 (although in some embodiments there may be a gap between the edge ring 230 and the retaining wall 260). The retaining wall 260 may be integrally formed with the chuck body 215 and / or may be a separate component that is subsequently coupled to the chuck body 215. The retaining wall 260 may be coupled to the outer surface of the chuck body 215 as illustrated herein and / or may rest on the chuck body 215 (similar to the edge ring 230) in other embodiments. The apparatus 200 may include a slurry exhaust port 265 that may be used to passively exhaust and / or actively pump slurry from the area within the retaining wall 260 before, during, and / or after a given polishing process. For example, the slurry exhaust port 265 may extend through the retaining wall 260 and / or the chuck body 215. In some embodiments, the slurry exhaust port 265 may extend through the edge ring 230.In such embodiments, the edge ring 230 may include one or more alignment features (such as pins) that ensure the edge ring 230 is properly oriented on the chuck body 215 to align portions of the slurry exhaust ports 265 on the edge ring 230 with portions of the slurry exhaust ports 265 on the chuck body 215 and / or retaining wall 260. While only a single slurry exhaust port 265 is shown, it will be understood that multiple exhaust ports may be used in various embodiments. For example, one or more slurry exhaust ports 265 may be located radially outward of the substrate support surface 217 (e.g., outside of, through, and / or below the edge ring 230), and / or one or more slurry exhaust ports 265 may extend through the substrate support surface 217. Such a configuration may better enable removal of slurry from all areas of the chuck body 215. When multiple slurry discharge ports 265 are disposed within a given region of the chuck body 215, the ports may be disposed at regular and / or irregular intervals around the chuck body 215.

[0033]

[0038] Although described primarily in the context of an apparatus using a CMP polishing pad, it will be understood that in some embodiments using an abrasive disk, a slurry source / port and / or retaining wall 260 may be present and / or utilized.

[0034]

[0039] In the process, the substrate 210 may be placed face up within the open interior of the edge ring 230 above the substrate support surface 217. A chucking force, such as a vacuum force and / or an electrostatic chucking force, may be applied to the substrate 210 to clamp the substrate 210 to the substrate support surface 217. In some cases, in addition to clamping the substrate 210 to the substrate support surface 217, the chucking force may reduce and / or eliminate any warping of the substrate 210 so that the substrate 210 is substantially flat before the polishing process begins. A spindle 235 and polishing pad 245 may be positioned on the edge region of the substrate 210. The polishing pad 245 may be positioned in contact with the surface of the substrate 210 and may be rotated to polish a film on the edge region of the substrate 210. In most cases, the spindle 235 and polishing pad 245 are rotated at a speed of about 60 to 200 rpm, about 80 to 180 rpm, about 100 to 160 rpm, or about 120 to 140 rpm, although other speeds are possible in various embodiments. The downward force of the polishing pad 245 can be adjusted by the drive mechanism 240 based on the needs of the particular polishing process. For example, the force can be adjusted from 0.5 psi to 10 psi, although other levels of force can be utilized in various embodiments. In some embodiments, the polishing pad 245 can be aligned coaxially with the substrate 210, which can be used to produce symmetric polishing of the entire edge region of the substrate 210. In other embodiments, the polishing pad 245 can be offset from the central axis of the substrate 210, which can enable asymmetric polishing to be performed. In some embodiments, the polishing pad 245 (and spindle 235) can be translated (or swept) laterally during rotation of the polishing pad 245 to control the eccentricity of the polishing pad 245 and alter the polishing pattern of the apparatus 200. In many cases, the lateral distance covered during a sweep can be 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, about 1 mm or less, or less. The speed of the sweeping motion can be adjusted based on the starting and / or desired film thickness profile.

[0035]

[0040] In embodiments where a CMP pad is used as the polishing pad 245, a slurry may be supplied to the substrate 210. The slurry may include abrasive particles that provide an abrasive that helps the CMP pad polish a film on the substrate. The slurry may be continuously and / or periodically supplied to the substrate 210 through a slurry supply port 255 and removed through a slurry exhaust port 265.

[0036]

[0041] The above process of the apparatus 200 may enable effective polishing of the edge region of the substrate 210, reducing non-uniformity issues. Furthermore, by using the laterally translatable spindle 235, the apparatus 200 may be swept and / or otherwise translated to account for asymmetric non-uniformity issues that may exist prior to edge polishing. The use of the edge ring 230 having an upper surface substantially aligned with the upper surface of the substrate 210 may provide a relatively consistent polishing surface extending radially outward from the substrate 210. This surface may help prevent deflection of the polishing pad 245 when a portion of the polishing pad 245 extends outward beyond the periphery of the substrate 210 (which may occur when the outer diameter of the polishing pad 245 is larger than the diameter of the substrate 210 and / or when asymmetric polishing is performed), thereby preventing significant release of the polishing pad and thereby distributing the polishing force uniformly across the edge region of the substrate 210, helping to uniformly polish the edge region. The edge polishing described herein can be used in combination with a conventional CMP polishing process to uniformly polish the entire film surface of the substrate. For example, edge polishing can be performed before and / or after conventional face-down CMP polishing, which can allow the interior region of the substrate to be uniformly polished by the conventional CMP polishing and the edge region of the substrate to be polished to a similar extent using the edge polishing apparatus 200.

[0037]

[0042] Although primarily described with respect to improving film uniformity in the edge region, it will be appreciated that the techniques described herein may also be used to generate other film thickness profiles in some embodiments by providing the ability to adjust the edge polishing process without affecting the polishing of the remainder of the substrate.

[0038]

[0043] FIG. 3 is a schematic, partial cross-sectional view illustrating an edge polishing apparatus 300 according to some embodiments of the present technique. As described above, the present technique can be used in some embodiments to perform an edge polishing process. The apparatus 300 can be similar to the apparatus 200 and can include any of the features, components, or characteristics of the supports described above, including any associated components. For example, the apparatus 300 can include a chuck body 315 defining a substrate support surface 317 on which a substrate can be placed. The apparatus 300 can include an edge ring 330 seated in the chuck body 315 and can include a spindle 335 and a polishing pad 345 for polishing the edge region of the substrate. In some embodiments, the apparatus 300 can include a slurry source 350, one or more slurry supply ports 355, a retaining wall 360, and / or one or more slurry exhaust ports 365.

[0039]

[0044] The apparatus 300 may be designed to polish substrates that are warped to such an extent that the substrate cannot be flattened without risking destruction. For example, the compressive and / or tensile stress of a substrate may be very high due to the chemistry of a particular film deposited on the substrate. To accommodate such substrates, one or more of the components of the apparatus 300 may be contoured and / or otherwise tapered to match the shape of the substrate (or the shape of a partially flattened substrate). For example, the substrate support surface 317 may be contoured to have a concave or convex shape (depending on whether the substrate exhibits compressive or tensile bow). The top surface of the edge ring 330 may taper (linearly or curvedly) toward the outer periphery of the edge ring 330. For example, if the substrate support surface 317 is concave (such as in the case of tensile bow), the top surface of the edge ring 330 may taper upward from the inner diameter to the outer diameter. If the substrate support surface 317 is convex (such as for compressive bow), the top surface of the edge ring 330 may taper downward from the inner diameter to the outer diameter. The height of the top surface at the inner diameter may substantially match the height of the peripheral edge of the substrate to provide a substantially constant interface between the top surface of the substrate and the edge ring 330.

[0040]

[0045] The spindle 335 and / or polishing pad 345 can be modified to handle a bowed substrate 310. For example, the spindle 335 and / or polishing pad 345 can be tapered such that the bottom surface of the polishing pad 345 tapers (either up or down to match the shape of the substrate and edge ring 330) toward the outer periphery of the polishing pad 345. This allows the bottom polishing surface of the polishing pad 345 to be oriented substantially parallel to the edge region of the substrate, resulting in substantially tangential contact between the polishing pad 345 and the substrate during the polishing process.

[0041]

[0046] 4 is a schematic, partial cross-sectional view illustrating a refinishing station 400 according to some embodiments of the present technique. The refinishing station 400 can be used to refinish, condition, and / or clean the surface of a polishing pad 445, such as the polishing pad 245 or 345 described herein. For example, the station 400 can include a pad conditioning assembly 405. In embodiments where the polishing pad 445 is a CMP pad, the pad conditioning assembly 402 can include a fixed abrasive conditioning disk 410. A spindle 435 (such as the spindle 235 or 335) can rotate the polishing pad 445 against the surface of the pad conditioning assembly 405 to polish, regenerate, and / or remove polishing by-products and other debris from the polishing surface of the polishing pad 445. In embodiments in which the polishing pad 445 is an abrasive disc, the pad conditioning pad may include a diamond dresser or other abrasive dresser that may be used to condition or dress the polishing surface of the polishing pad 445 .

[0042]

[0047] FIG. 5 is a schematic top plan view illustrating a polishing chamber 500 according to some embodiments of the present technology. The chamber 500 may include any number of stations 505 that can be used to perform one or more polishing processes. For example, the chamber 500 may include at least about one station, at least about two stations, at least about three stations, at least about four stations, or more stations. Each station 505 may include one or more polishing systems. For example, the stations 505 may include one or more conventional CMP systems 505a (such as system 100), one or more edge polishing apparatuses 505b (such as apparatus 200 or 300), and / or one or more refinishing stations 505c (such as station 400). The various stations may be provided in any number, arrangement, and / or combination. By way of example only, the chamber 500 may include two CMP stations 505a, one edge polishing apparatus 505b, and one refinishing station 505c. The chamber 500 can include one or more robots 510 that can be used to move substrates from one station 505 to another. For example, the robot 510 can transfer a substrate between one of the CMP stations 505a and the edge polisher 505b. The spindle of the edge polisher 505b can move a polishing pad between the edge polisher and the refinishing station.

[0043]

[0048] FIG. 6 illustrates exemplary steps in a method 600 for polishing a substrate according to some embodiments of the present technique. Method 600 can be performed using an edge polishing apparatus, such as edge polishing apparatus 200 or 300 described herein. Method 600, in some embodiments, can include steps prior to substrate polishing. For example, prior to polishing, the substrate may undergo one or more deposition and / or etching steps, as well as any planarization or other process steps. Method 600 can include numerous steps that can be performed automatically within a system to limit manual interaction and increase efficiency and accuracy over manual processes. Method 600 can be performed in conjunction with a conventional CMP polishing process. For example, a conventional CMP polishing process can be performed before and / or after method 600.

[0044]

[0049] In step 605, the method 600 may include placing a substrate face-up within an open interior of an edge ring disposed on a substrate support surface of a chuck body of an edge polishing apparatus. The substrate may be clamped to the chuck body in step 610. For example, a chucking mechanism may be activated to apply a vacuum chucking force and / or an electrostatic chucking force that may clamp and / or planarize the substrate against the substrate support surface. In step 615, the upper surface of the substrate may be engaged with an annular polishing pad. In step 620, the annular polishing pad may be rotated in contact with the upper surface of the substrate to polish the edge region of the substrate. For example, while the annular polishing pad is rotated in contact with the upper surface of the substrate to uniformly polish the edge region, the central axis of the polishing pad may be coaxial with the central axis of the substrate. While rotating the annular polishing pad in contact with the upper surface of the substrate, the central axis of the polishing pad may be offset from the central axis of the substrate to polish away asymmetric film thickness non-uniformity issues in the edge region. In some embodiments, the annular polishing pad can be rotated against the top surface of the substrate while being laterally translated or swept relative to the surface of the substrate to polish the substrate in a desired pattern and / or to achieve a desired film thickness profile. A downward force can be applied to the annular polishing pad while the annular polishing pad is rotated relative to the top surface of the substrate. The magnitude of the downward force can be adjusted to control the polishing rate of the edge polishing apparatus.

[0045]

[0050] In some embodiments, such as those in which a CMP pad is used as the polishing pad, method 600 may include supplying a slurry to the substrate. The slurry may include abrasive particles that provide abrasive grains that help the CMP pad polish a film on the substrate. The slurry may be continuously and / or periodically supplied to the substrate through a slurry supply port. Once a predetermined polishing step is completed, the slurry may be removed from the apparatus, for example, by draining and / or pumping the slurry through a slurry drain port.

[0046]

[0051] In some embodiments, method 600 may include regenerating the surface of the annular polishing pad. For example, after one or more polishing steps, the polishing pad may lose abrasive grains, become saturated with slurry and / or film debris, and / or otherwise become unsuitable for further steps. In such embodiments, the spindle holding the polishing pad may be manipulated to engage the polishing pad with a pad conditioning assembly. The polishing pad may be rotated against the pad conditioning assembly to polish the polishing surface, regenerate the polishing surface, remove polishing by-products and other debris from the polishing surface, and / or condition or dress the polishing surface of the polishing pad. Once the surface is regenerated, the polishing pad may be returned to service to polish one or more additional substrates.

[0047]

[0052] In the foregoing specification, for purposes of explanation, numerous details have been 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 particular embodiments may be practiced without some of these details or with additional details.

[0048]

[0053] Although several embodiments have been disclosed, those skilled in the art will recognize that various modifications, alternative structures, and equivalents may be used without departing from the spirit of the embodiments. Moreover, in order to avoid unnecessarily obscuring the present technology, some well-known processes and elements have not been described. Therefore, the above specification should not be interpreted as limiting the scope of the present technology.

[0049]

[0054] 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 where the smaller range includes one, both, or neither limit is also included within the technology, subject to any specifically excluded limit 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.

[0050]

[0055] 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, a reference to "a heater" includes a plurality of such heaters, a 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.

[0051]

[0056] 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 apparatus for polishing a substrate edge region, comprising: a chuck body defining a substrate support surface; an edge ring seated on the chuck body, the edge ring configured to accommodate a substrate positioned within an open interior of the edge ring and having a thickness such that a top surface of the edge ring is above the substrate support surface; a retaining wall disposed radially outward of the edge ring; a slurry supply port disposed radially inward of the retaining wall; a spindle disposed on the chuck body and configured to be rotatable relative to the chuck body; an annular polishing pad coupled to the lower end of the spindle; Equipped with Polishing equipment.

2. The inner diameter of the annular polishing pad is smaller than the inner diameter of the edge ring. The polishing apparatus according to claim 1 .

3. 2. The polishing apparatus of claim 1, wherein the spindle is laterally translatable relative to the chuck body.

4. 2. The polishing apparatus of claim 1, wherein the height of the upper surface of the edge ring is within about 10 microns of the height of the substrate placed on the substrate support surface.

5. 10. The polishing apparatus of claim 1, further comprising a slurry discharge port disposed within one or both of the chuck body and the retaining wall.

6. The polishing apparatus according to claim 1 , wherein the outer edge of the edge ring is disposed in contact with the inner surface of the retaining wall.

7. The polishing apparatus of claim 1 , wherein the edge ring is removably coupled to the chuck body.

8. 1. A polishing apparatus for polishing a substrate edge region, comprising: a chuck body defining a substrate support surface; an edge ring seated on the chuck body, the edge ring configured to accommodate a substrate positioned within an open interior of the edge ring, the edge ring having a thickness such that a top surface of the edge ring is above the substrate support surface, and the edge ring having an inner diameter that is less than about 5% larger than a diameter of the substrate support surface; a spindle positionable on the chuck body; a rotational drive mechanism coupled to the spindle; an annular polishing pad coupled to the lower end of the spindle; A polishing apparatus comprising:

9. The polishing apparatus of claim 8 , wherein the annular polishing pad comprises a CMP polishing pad or an abrasive disk.

10. an upper surface of the edge ring tapered toward an outer periphery of the edge ring; 9. The polishing apparatus according to claim 8, wherein the bottom surface of the annular polishing pad is tapered toward the outer periphery of the annular polishing pad.

11. The polishing apparatus of claim 8 , wherein the chuck body comprises an electrostatic chuck or a vacuum chuck.

12. a retaining wall disposed radially outward of the edge ring; a source of abrasive slurry; a slurry supply port fluidly coupled to the polishing slurry source, the slurry supply port being positioned radially inward of the retaining wall; The polishing apparatus according to claim 8 , further comprising:

13. 9. The polishing apparatus according to claim 8, wherein the upper surface of the substrate support surface is concave or convex.

14. 10. The polishing apparatus of claim 8, wherein the polishing apparatus is disposed in a polishing chamber including a face-down polishing station.

15. A method for polishing an edge region of a substrate, the method comprising the steps of: placing the substrate face up within an open interior of an edge ring disposed above the substrate support surface of the chuck body; clamping the substrate to the chuck body; engaging an upper surface of the substrate with an annular polishing pad; rotating the annular polishing pad in contact with an upper surface of the substrate; A method comprising:

16. Translating the annular polishing pad laterally while rotating the annular polishing pad in contact with the upper surface of the substrate.

16. The method of claim 15, further comprising:

17. applying a polishing slurry to an upper surface of the substrate; 16. The method of claim 15, further comprising:

18. applying a downward force to the annular polishing pad while rotating the annular polishing pad against the top surface of the substrate; 16. The method of claim 15, further comprising:

19. 16. The method of claim 15, wherein a central axis of the annular polishing pad is offset from a central axis of the substrate while the annular polishing pad is rotated against the top surface of the substrate.

20. Regenerating the surface of the annular polishing pad.

16. The method of claim 15, further comprising:

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