Upward Wafer Electrochemical Planarization Equipment

Abstract

An exemplary substrate electrochemical planarization apparatus may include a chuck body that defines a substrate support surface. The apparatus may include a retaining wall extending from the chuck body. The apparatus may include an electrolyte delivery port disposed radially inward of the retaining wall. The apparatus may include a spindle positionable over the chuck body. The apparatus may include an end effector coupled to the lower end of the spindle. The end effector may be conductive. The apparatus may include an electrical contact extending from the chuck body or the retaining wall. The apparatus may include a current source. The current source may be configured to provide a current to an electrolyte within an opening defined by the retaining wall.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0001] This application claims the benefit and priority of U.S. Patent Application No. 17 / 833,422, filed on June 6, 2022, entitled "FACE - UP WAFER ELECTROCHEMICAL PLANARIZATION APPARATUS", the entire disclosure of which is incorporated herein by reference.

[0002]

[0002] This technology relates to semiconductor systems, processes, and equipment. More specifically, this technology relates to the planarization of films deposited on a substrate.

Background Art

[0003]

[0003] Integrated circuits are typically formed on a substrate by successive deposition of conductive, semiconductive, and / or insulating layers on a silicon wafer. In a variety of manufacturing processes, planarization of the layers on the substrate between processing steps is used. For example, in certain applications, such as when planarizing a metal layer to form vias, plugs, and / or lines in the trenches of a patterned layer, the upper layer is planarized until the upper surface of the patterned layer is exposed. In other applications, such as when planarizing a dielectric layer in photolithography, the upper layer is polished until a desired thickness remains on the lower layer.

[0004]

[0004] Chemical mechanical polishing (CMP) is one common planarization method. In this planarization method, it is usually necessary to attach the substrate to a carrier or a polishing head. The exposed surface of the substrate is typically arranged to abut against a rotating polishing pad. The carrier head applies a controllable load to the substrate, pressing the substrate against the polishing pad. Usually, a polishing slurry for polishing is supplied to the surface of the polishing pad.

[0005]

[0005] One problem in CMP is to polish the entire surface of the substrate uniformly. Often, the mechanical forces applied during the CMP process can remove the exposed portions of the first material at a faster rate than the exposed portions of the second material, which can lead to non-uniform polishing. As a result, the film thickness across the substrate becomes non-uniform, and some materials, such as metal materials, are removed faster than, for example, dielectric materials, resulting in dishing of the metal material. This non-uniformity of the film causes lithography problems and can lead to a decrease in the die yield from a given substrate.

[0006]

[0006] Accordingly, there is a need for improved systems and methods that can be used to polish or planarize a substrate to produce a uniform film across the entire surface area of the substrate. The present technology addresses these and other needs.

Summary of the Invention

[0007]

[0007] An exemplary substrate electrochemical planarization apparatus can include a chuck body that defines a substrate support surface. The apparatus can include a retaining wall that extends from the chuck body. The apparatus can include an electrolyte delivery port disposed radially inward of the retaining wall. The apparatus can include a spindle that can be positioned over the chuck body. The apparatus can include an end effector coupled to the lower end of the spindle. The end effector can be conductive. The apparatus can include an electrical contact that extends from the chuck body or the retaining wall. The apparatus can include a current source. The current source can be configured to provide current to an electrolyte within an opening defined by the retaining wall.

[0008]

[0008] In some embodiments, the end effector may be characterized by a diameter of about 150 mm or less than about 150 mm. The spindle may be rotatable and may be translatable laterally relative to the chuck body. The surface of the end effector facing the substrate support surface may be flat. The retaining wall may be annular. The diameter of the end effector may be smaller than the inner diameter of the retaining wall. The apparatus may include an electrolyte discharge port positioned within one or both of the chuck body and the retaining wall. The apparatus may include an edge ring mounted on the chuck body.

[0009]

[0009] Some embodiments of the present disclosure include a substrate electrochemical planarization apparatus. The apparatus may include a chuck body that defines a substrate support surface. The apparatus may include a spindle positionable over the chuck body. The apparatus may include a rotational drive mechanism coupled to the spindle. The apparatus may include an end effector coupled to the lower end of the spindle. The apparatus may include an electrical contact extending from the chuck body. The apparatus may include a current source. The current source may be configured to provide current to an electrolyte within an opening defined by a retaining wall extending from the chuck body.

[0010]

[0010] In some embodiments, the end effector includes a conductive material. The apparatus may include an edge ring mounted on the chuck body. The inner diameter of the edge ring may be greater than the diameter of the substrate support surface by less than about 5%. The apparatus may include a retaining wall disposed radially outward of the chuck body. The retaining wall may be annular. The diameter of the end effector may be smaller than the inner diameter of the retaining wall. The apparatus may include an electrolyte source. The apparatus may include an electrolyte delivery port in fluid communication with the electrolyte source. The electrolyte delivery port may be disposed radially inward of the retaining wall. The substrate electrochemical planarization apparatus may be disposed within a polishing chamber having a downward polishing station.

[0011]

[0011] Some embodiments of the present disclosure include a method of planarizing a substrate. The method may include positioning the substrate upwardly on a substrate support surface of the chuck body within an opening defined by a retaining wall extending from the chuck body. The method may include clamping the substrate to the chuck body. The method may include delivering an electrolyte to an upper surface of the substrate. The method may include engaging the upper surface of the substrate with an end effector coupled to a lower end of a spindle. The method may include applying an electric current to the electrolyte.

[0012]

[0012] In some embodiments, the method may include rotating the end effector relative to the upper surface of the substrate while translating the spindle laterally. The method may include moving the end effector relative to the substrate. A downward force of about 2.0 psi or less than about 2.0 psi may be applied to the end effector while rotating the end effector relative to the upper surface of the substrate. The central axis of the end effector may be offset from the central axis of the substrate while rotating the end effector relative to the upper surface of the substrate. The method may include discharging the electrolyte from within the opening through an electrolyte discharge port positioned within one or both of the chuck body and the retaining wall.

[0013]

[0013] Such techniques may provide a number of benefits over conventional systems and techniques. For example, the electrochemical planarization apparatus described herein may enable planarization of a substrate without removing a portion of the exposed material at a faster rate than other portions of the exposed material during the planarization process. Often, the planarization techniques described herein may be used before and / or after a conventional CMP process. This may enable improvement in the film thickness and metal feature uniformity across the surface of the substrate, and may increase the die yield. These embodiments and other embodiments are described in more detail below in conjunction with the following description and the accompanying figures, along with many of their advantages and features.

[0014] A further understanding of the nature and advantages of the disclosed technology can be realized by referring to the following portions of this specification and the drawings.

Brief Description of the Drawings

[0015]

Figure 1

[0015] FIG. is a schematic cross-sectional view of an exemplary chemical mechanical planarization system according to some embodiments of the present technology.

Figure 2

[0016] FIG. is a schematic partial cross-sectional view of an exemplary electrochemical planarization apparatus according to some embodiments of the present technology.

Figure 3

[0017] FIG. is a schematic partial top view of an exemplary polishing chamber according to some embodiments of the present technology.

Figure 4

[0018] FIG. is a flowchart of an exemplary method for planarizing a substrate according to some embodiments of the present technology.

Modes for Carrying Out the Invention

[0016]

[0019] Some of the figures are included as schematic diagrams. It should be understood that the figures are for illustrative purposes only and are not to be considered to be to scale unless explicitly stated to be so. Further, as schematic diagrams, the figures are provided to aid understanding and may not include all aspects or information compared to a realistic depiction, and may include materials emphasized for illustrative purposes.

[0017]

[0020] In the accompanying figures, similar components and / or features may have the same reference numerals. Further, various components of the same type may be distinguished according to the reference numerals by letters that distinguish between similar components. When only a first reference numeral is used in this specification, the description is applicable to any one of the similar components having the same first reference numeral regardless of the letter.

[0018]

[0021] In a conventional chemical mechanical polishing (CMP) process, it is often difficult to polish the surface of a substrate uniformly. Conventional CMP polishing involves positioning the substrate downward on a polishing pad and using a carrier to hold the substrate against the rotating polishing pad. However, the pressure between the polishing pad and the substrate often applies mechanical force, resulting in non-uniform film thickness after the polishing process. For example, mechanical force may cause dishing of the metal material within the trenches exposed on the surface of the substrate. These problems can lead to non-uniformity problems that reduce the die yield. Further, when the metal material within the trenches wears, the electrical connections of the final integrated circuit or other device may be damaged and / or become very thin, and when current passes through the electrical connections, it can lead to an increase in heat and subsequent connection failures.

[0019]

[0022] The present technology provides an electrochemical planarization apparatus that can be used to planarize metal features (e.g., copper, cobalt, molybdenum, tungsten, and / or ruthenium features) on a substrate in a conventional CMP system, while minimizing non-uniformity and preventing dishing or other erosion of the metal material within trenches or other recesses formed between areas of the film, thereby overcoming these problems. Specifically, an electrochemical process can be provided that enables selective removal of only the metal material in contact with the surface of the conductive end effector, preventing the material beneath the surface of the non-metal film (e.g., within trenches or other recesses) from being removed because it does not contact the surface of the end effector. These techniques can be used in conjunction with a conventional CMP system (capable of planarizing non-metal features) to produce a substrate in a state with improved thickness uniformity. Further, embodiments can include a chuck mechanism that can assist in planarizing the substrate during planarization, which can further improve the uniformity achieved during the planarization process. Embodiments can enable the end effector to translate laterally with respect to the substrate, allowing the electrochemical planarization apparatus to improve non-uniformity problems.

[0020]

[0023] The remaining disclosure identifies a particular film measurement process that utilizes the disclosed technology in the normal manner, but it will be readily understood that the systems and methods are equally applicable to a wide variety of other semiconductor processing steps and systems. Thus, the technology should not be considered limited to use only with the described electrochemical planarization systems or processes. Before discussing the systems and methods or steps of an exemplary process sequence according to some embodiments of the technology in this disclosure, one possible system that can be used in the technology will be discussed. It should be understood that the technology is not limited to the described apparatus, and the processes discussed can be carried out in any number of processing chambers and systems with any number of modifications (some of which are described later).

[0021]

[0024] FIG. 1 shows a schematic cross-sectional view of an exemplary polishing system 100 according to some embodiments of the present technology. The polishing system 100 includes a platen assembly 102 that includes a lower platen 104 and an upper platen 106. The lower platen 104 can define an internal space or cavity through which connections can be made, and the internal space or cavity can include endpoint detection equipment or other sensors or devices (e.g., eddy current sensors, optical sensors, or other components for monitoring the polishing process or components). For example, as will be described further below, a fluid coupling can be formed in a line that passes through the lower platen 104 and accesses the upper platen 106 through the back side of the upper platen. The platen assembly 102 can include a polishing pad 110 attached to a first surface of the upper platen. A substrate carrier 108, or carrier head, can be positioned above the polishing pad 110 and can face the polishing pad 110. The platen assembly 102 can be rotatable about an axis A, while the substrate carrier 108 can be rotatable about an axis B. The substrate carrier can also be configured to reciprocally sweep from an inner radius to an outer radius along the platen assembly, which can, in part, reduce non-uniform wear on the surface of the polishing pad 110. The polishing system 100 can also include a fluid supply arm 118 positioned above the polishing pad 110 and used to deliver a polishing fluid, such as a polishing slurry, onto the polishing pad 110. Further, a pad conditioning assembly 120 can be positioned above the polishing pad 110 and can face the polishing pad 110.

[0022]

[0025] In some embodiments of performing a chemical mechanical polishing process, the rotating and / or sweeping substrate carrier 108 can exert a downward force on the substrate 112, which is shown by the phantom line and can be disposed within or coupled to the substrate carrier. The applied downward force may push down the material surface of the substrate 112 against the polishing pad 110 because the polishing pad 110 rotates about the central axis of the platen assembly. The interaction between the substrate 112 and the polishing pad 110 can occur in the presence of one or more polishing fluids delivered by the fluid supply arm 118. A typical polishing fluid can include a slurry formed of an aqueous solution in which polishing particles can be suspended. Often, the polishing fluid includes other chemically active components such as a pH adjuster and an oxidizing agent, which can enable chemical mechanical polishing of the material surface of the substrate 112.

[0023]

[0026] The pad conditioning assembly 120 can be operated to apply a fixed conditioning disk 122 against the surface of the polishing pad 110, which can rotate as described above. The conditioning disk can be operated against the pad before, after, or during polishing of the substrate 112. When the polishing pad 110 is conditioned using the conditioning disk 122, the polishing pad 110 can be maintained in a desired state by polishing, regenerating, 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 the mounting surface of the lower platen 104 and may be coupled to the lower platen 104 using a plurality of fasteners 138, such as passing through the annular flange-shaped portion of the lower platen 104.

[0024]

[0027] The polishing platen assembly 102, and thus the upper platen 106, can be sized to be suitable for any desired polishing system and can be of a size for substrates of any diameter including 200 mm, 300 mm, 450 mm, or more. For example, a polishing platen assembly configured to polish a 300 mm diameter substrate can be characterized as having a diameter of about 300 mm or more, such as from about 500 mm to about 1000 mm, or about 500 mm or more. The platen can be adjusted in diameter to accommodate substrates having a larger or smaller diameter or for a polishing platen 106 sized for simultaneous polishing of multiple substrates. The upper platen 106 can be characterized as having a thickness from about 20 mm to about 150 mm and can be characterized as having 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 the diameter to the thickness of the polishing platen 106 can be about 3:1 or greater than about 3:1, about 5:1 or greater than about 5:1, about 10:1 or greater than about 10:1, about 15:1 or greater than about 15:1, about 20:1 or greater than about 20:1, about 25:1 or greater than about 25:1, about 30:1 or greater than about 30:1, about 40:1 or greater than about 40:1, about 50:1 or greater than about 50:1, or more.

[0025]

[0028] The upper platen and / or the lower platen can be formed of a suitable rigid, lightweight, and corrosion-resistant material for polishing fluid, such as aluminum, aluminum alloy, or stainless steel, but any number of materials can be used. The polishing pad 110 can be formed of any number of materials, including polymer materials such as polyurethane, polycarbonate, fluoropolymer, polytetrafluoroethylene, polyphenylene sulfide, or any combination of these or other materials. Further materials may include or contain a polymer of continuous or closed cells, an elastomer, a felt, an impregnated felt, a plastic, or any other material that is compatible with the processing chemicals. The polishing system 100 is included to provide appropriate reference to the components described below that can be incorporated into the system 100. However, the description of the polishing system 100 is not intended to limit the present technology in any form, as the embodiments of the present technology can be incorporated into any number of polishing systems that can benefit from the components and / or functions as further described below.

[0026]

[0029] Figure 2 shows a schematic cross-sectional view of an exemplary electrochemical planarization apparatus 200 according to some embodiments of the present technology. The apparatus 200 can be used to perform a planarization process. The apparatus 200 can show a partial view of the components that can be incorporated into the semiconductor processing system being discussed. The apparatus 200 can 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 other types of chuck systems. For example, the chuck body 215 can define several channels 220 connected to a vacuum source 225. The vacuum source 225 can create a negative pressure in the channels 220 that clamp the substrate 210 to the chuck body.

[0027]

[0030] In other embodiments, the chuck body 215 may include an electrostatic chuck. In such 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 (e.g., a metal such as aluminum, or any other material that may be thermally and / or electrically conductive), and may be connected to a power source (e.g., 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 that may be an impedance matching circuit so that the electrostatic chuck body 215 can operate as an electrode. In other embodiments, the upper portion of the electrostatic chuck body 215 may be formed from a dielectric material. In such embodiments, the electrostatic chuck body 215 may include separate electrodes that can be embedded within the chuck body 215 in proximity to the substrate support surface. Each electrode may be electrically connected to a DC power source that provides energy or voltage to the electrode. During operation, the substrate 210 may be at least partially in contact with the substrate support surface of the chuck body, which can create a contact gap and a substantially capacitive effect between the surface of the pedestal and the substrate. A voltage may be applied across the contact gap to generate an electrostatic force for the chuck.

[0028]

[0031] The plurality of lift pins 227 may pass through a plurality of holes formed in the chuck body 215. The lift pins 227 have a first end that is substantially in the same plane as the upper surface of the chuck body 215 or slightly recessed from the upper surface of the chuck body 215 when the lift pins 227 are in their normal position (i.e., stored relative to the chuck body 215). The first end may be flared or otherwise enlarged (not shown) to prevent the lift pins 227 from falling out of the holes formed in the chuck body 215. Further, the lift pins 227 have a second end that extends beyond the lower side of the chuck body 215.

[0029]

[0032] The edge ring 230 can be placed on the chuck body 215. For example, the edge ring 230 can be positioned around the substrate support surface 217 such that the substrate 210 is disposed within the opening of the edge ring 230. The edge ring 230 may help to maintain the substrate 210 in a desired position when the end effector 245 moves relative to the upper surface of the substrate 210. The inner diameter of the edge ring 230 may be about 5% or less than about 5% larger than the diameter of the substrate 210, about 4% or less than about 4% larger than the diameter of the substrate 210, about 3% or less than about 3% larger than the diameter of the substrate 210, about 2% or less than about 2% larger than the diameter of the substrate 210, about 1% or less than about 1% larger than the diameter of the substrate 210, about 0.5% or less than about 0.5% larger than the diameter of the substrate 210, or less. For example, in the case of a substrate 210 having a diameter of 300 mm, the edge ring 230 can have an inner diameter in the range of at least 300 mm to about 315 mm, but often the inner diameter may be from about 300.5 mm to 305 mm. The thickness of the edge ring 230 can substantially match the thickness of the substrate 210. For example, the thickness of the edge ring 230 can 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, in the case of a substrate 210 having a thickness of 1 mm, the thickness of the edge ring 230 can be from about 0.970 mm to 1.030 mm, from about 0.980 mm to 1.020 mm, from about 0.990 mm to 1.010 mm, from about 0.995 mm to 1.005 mm, or about 1 mm. In some embodiments, the upper surface of the chuck body 215 on which the edge ring 230 is placed can be raised and lowered. In such embodiments, the thickness of the edge ring 230 can be adjusted such that the upper surface of the edge ring 230 is within about 3% of the height of the upper surface of the substrate 210, within about 2% of the height of the upper surface of the substrate 210, within about 1% of the height of the upper surface of the substrate 210, within about 0.5% of the height of the upper surface of the substrate 210, or less.

[0030]

[0033] The edge ring 230 can be detachably coupled to the chuck body 215. For example, one or more clamps, fasteners, and / or other coupling mechanisms can be used to secure the edge ring 230 to the upper surface of the chuck body 215. This can enable the edge ring 230 to be removed for repair, cleaning, and / or replacement.

[0031]

[0034] The apparatus 200 may include a spindle 235 that can be positioned on the chuck body 215. Here, it is shown as having a hollow cylindrical body, but the spindle 235 may be formed from other shapes and / or may be solid in various embodiments. The spindle 235 may be rotatable and translatable in a direction perpendicular and / or transverse to the chuck body 215. For example, the spindle 235 may be connected to an arm 240. Here, it is shown as having a hollow cylindrical body, but the arm 240 may be formed from other shapes and / or may be solid in various embodiments. The arm 240 may be translatable in a direction perpendicular and / or transverse to the chuck body 215. The spindle 235 and / or the arm 240 may be connected to one or more motors and / or other drive mechanisms that can drive the rotation and / or translation of the spindle 235. The lower end of the spindle 235 may include an end effector 245. The end effector 245 can be removably connected to the lower end of the spindle 235, whereby the end effector 245 can be reworked, cleaned, and / or replaced as needed. For example, the end effector 245 may be connected to the lower end of the spindle 235 using an adhesive (e.g., a pressure-sensitive adhesive), a snap connector, a hook and loop connector, and / or other coupling mechanisms that may enable the end effector 245 to be removably connected to the spindle 235. A current source 275 can apply current to the spindle 235, the arm 240, and / or the end effector 245 from the electrical contact 270, the chuck body 215, and / or the retaining wall 260. A circuit can be completed between the electrical contact 270, the electrolyte, the metal material on the substrate 210, and the end effector 245 that delivers current to the metal material to perform electrochemical planarization of the substrate 210.

[0032]

[0035] The end effector 245 may include a substantially flat exposed (e.g., bottom) contact surface that is formed from a conductive material and / or may include a conductive material in other ways. For example, the exposed contact surface may be at least about 95% flat, at least about 97% flat, at least about 99% flat, or more. Such a design can ensure that the exposed surface can maintain uniform contact with the surface of the substrate 210 during planarization to ensure that the metal material is planarized with high precision. The end effector 245 may be a mesh material such as a conductive mesh (e.g., metal) covered with a polymer material. In some embodiments, the end effector 245 may include and / or be formed from a conductive polymer material. The conductive material may be electrically connected to the current source 275 via one or more wires or other conductors that pass through the spindle 235, are coupled to the spindle 235, and / or form part of the spindle 235. By using a polymer material, scratches on the substrate film that occur when using materials such as metal can be reduced or eliminated.

[0033]

[0036] The end effector 245 can have a circular, polygonal, annular, or any other shape sized such that the end effector 245 can planarize only a specific region of the substrate 210. For example, the diameter of the end effector 245 may be smaller than the diameter of the substrate 210 (and may also be smaller than the inner diameter of the edge ring 230). For example, the diameter of the end effector 245 may be about 90% or less than about 90% of the diameter of the substrate 210, about 80% or less than about 80% of the diameter of the substrate 210, about 70% or less than about 70% of the diameter of the substrate 210, about 60% or less than about 60% of the diameter of the substrate 210, about 50% or less than about 50% of the diameter of the substrate 210, about 40% or less than about 40% of the diameter of the substrate 210, about 30% or less than about 30% of the diameter of the substrate 210, about 20% or less than about 20% of the diameter of the substrate 210, about 15% or less than about 15% of the diameter of the substrate 210, about 10% or less than about 10% of the diameter of the substrate 210, about 8% or less than about 8% of the diameter of the substrate 210, about 6% or less than about 6% of the diameter of the substrate 210, about 4% or less than about 4% of the diameter of the substrate 210, about 2% or less than about 2% of the diameter of the substrate 210, or less. For example, in the case of a 300 mm substrate 210, the diameter of the end effector 245 may be about 270 mm or less than about 270 mm, about 240 mm or less than about 240 mm, about 210 mm or less than about 210 mm, about 180 mm or less than about 180 mm, about 150 mm or less than about 150 mm, about 120 mm or less than about 120 mm, about 90 mm or less than about 90 mm, about 60 mm or less than about 60 mm, about 45 mm or less than about 45 mm, about 30 mm or less than about 30 mm, about 24 mm or less than about 24 mm, about 18 mm or less than about 18 mm, about 12 mm or less than about 12 mm, about 6 mm or less than about 6 mm, or less. However, it is also envisioned that the diameter of the end effector 245 may be greater than about 100% or about 100% of the diameter of the substrate 210. For example, in the case of a 300 mm substrate 210, the outer diameter of the end effector 245 may be about 300 mm or greater than about 300 mm.

[0034]

[0037] In an embodiment, apparatus 200 may include a plurality of end effectors 245. For example, apparatus 200 may include at least about 1 end effector, at least about 2 end effectors, at least about 3 end effectors, at least about 4 end effectors, or more end effectors. Each of the plurality of end effectors 245 may be coupled to the lower end of spindle 235, which may be coupled to arm 240 as described above. The plurality of end effectors 245 can reduce the processing time and may improve the overall throughput. The plurality of end effectors 245 can increase the current density at a specific location and may be able to remove metal material more efficiently.

[0035]

[0038] The apparatus 200 may include an electrolyte delivery port 250. The electrolyte delivery port 250 may be connected to an electrolyte source 255 and may deliver the electrolyte from the electrolyte source 255 to the surface of the substrate 210 during the planarization process. The electrolyte may include an aqueous solution containing ions that are conductive by the movement of the ions. For example, the electrolyte may be sulfuric acid, citric acid, ethylenediamine, hexadiamine, amino acids, ammonium oxalate, ammonium citrate, ammonium succinate, monobasic potassium citrate, dibasic potassium citrate, tribasic potassium citrate, tartaric acid, potassium tartrate, ammonium tartrate, succinic acid, potassium succinate, oxalic acid, potassium oxalate, malic acid, salicylic acid, benzotriazole, mercaptobenzotriazole, 5-methyl-1-benzotriazole, hydroxybenzotriazole, potassium hydroxide, ammonium hydroxide, and combinations thereof, or any other suitable electrolytic material, or may include these. The electrolyte may include about 1 wt% to about 0.01 wt% of silica, alumina, or zirconia polishing particles. The silica, alumina, or zirconia polishing particles may be characterized by a D50 of about 50 nm. In embodiments, the electrolyte may include various additives such as chelating agents, lubricants, oxidizing agents, corrosion inhibitors, pH adjusters, and / or catalyst agents. The chelating agent may help to bind so that the removed metal material does not redeposit. The lubricant may prevent scratching the metal material that is not removed from the substrate 210. To prevent the electrolyte from spreading away from the substrate 210, the apparatus 200 may include a retaining wall 260. The retaining wall 260 may be an annular body extending from the chuck body 215. The retaining wall 260 may be positioned radially outward from both the edge ring 230 and the electrolyte delivery port 250 such that any electrolyte delivered to the substrate 210 through the electrolyte delivery port 250 is close to the substrate 210. Although the electrolyte delivery port 250 is shown positioned above the retaining wall 260, in some embodiments, the electrolyte delivery port 250 may penetrate through a portion of the retaining wall 260 and / or the chuck body 215.To help minimize the amount of electrolyte required for a given planarization process, the inner surface of the retaining wall 260 may be positioned proximate to and may 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 later coupled to the chuck body 215. The retaining wall 260 may be coupled to the outer surface of the chuck body 215 as shown herein and / or, in other embodiments, may be placed on top of the chuck body 215 (similar to the edge ring 230). That is, the retaining wall 260 may extend from the chuck body 215. The apparatus 200 may include an electrolyte drain port 265 that can be used to passively drain and / or actively pump out electrolyte from an area within the retaining wall 260 before, during, and / or after a given planarization process. For example, the electrolyte drain port 265 may pass through the retaining wall 260 and / or the chuck body 215. In some embodiments, the electrolyte drain port 265 may also pass through the edge ring 230. In such embodiments, the edge ring 230 may include one or more alignment features (e.g., pins) to ensure that the edge ring 230 is properly oriented on the chuck body 215 to align the portion of the electrolyte drain port 265 on the edge ring 230 with the portion of the electrolyte drain port 265 on the chuck body 215 and / or the retaining wall 260. Although only a single electrolyte drain port 265 is shown, it will be understood that in various embodiments, multiple electrolyte drain ports may be used. For example, one or more electrolyte drain ports 265 may be positioned radially outside of the substrate support surface 217 (e.g., outside the edge ring 230, through the edge ring 230, and / or below the edge ring 230) and / or one or more electrolyte drain ports 265 may pass through the substrate support surface 217. Such a configuration may make it easier to remove electrolyte from all areas of the chuck body 215.When a plurality of electrolyte discharge ports 265 are positioned within a given area of the chuck body 215, the electrolyte discharge ports can be positioned at regular and / or irregular intervals around the chuck body 215.

[0036]

[0039] In embodiments, an electrolyte can be delivered to the substrate 210. The electrolyte can include ions that are conductive by the movement of the ions. When a current is applied, the cations of the electrolyte are attracted to the electron-rich electrode, while the anions of the electrolyte are attracted to the electron-deficient electrode. When the anions and cations in the solution move in opposite directions to each other, a current is generated. The electrolyte may not include abrasive particles that can provide grit for the end effector 245 to mechanically remove a film on the substrate. The electrolyte can be delivered to the substrate 210 continuously and / or periodically via the electrolyte delivery port 250 and removed via the electrolyte discharge port 265. During operation, an appropriate amount that contacts the upper surface of the substrate 210 can be provided to the apparatus 200. For example, an electrolyte of about 500 cubic centimeters (cc) or more than about 500 cubic centimeters (cc) can be provided. In some embodiments, a smaller amount of electrolyte (e.g., about 500 cc or less than about 500 cc, about 450 cc or less than about 450 cc, about 400 cc or less than about 400 cc, about 350 cc or less than about 350 cc, about 300 cc or less than about 300 cc, about 250 cc or less than about 250 cc, about 200 cc or less than about 200 cc, about 150 cc or less than about 150 cc, about 100 cc or less than about 100 cc, about 50 cc or less than about 50 cc, or less) can be provided.

[0037]

[0040] Apparatus 200 may include an electrical contact 270. The electrical contact 270 may extend from the chuck body 215 and / or the retaining wall 260. During operation, the electrical contact 270 may provide current to an electrolyte within the opening defined by the retaining wall 260. The current 275 applied to the electrolyte may facilitate removal of material during a planarization process when the conductive end effector 245 contacts a metal feature of the substrate 210. The current 275 may be applied from the electrical contact 270, the chuck body 215, and / or the retaining wall 260 to the spindle 235, the arm 240, and / or the end effector 245. The current 275 may complete a circuit necessary to perform electrochemical planarization of the substrate 210. Although only a single electrical contact 270 is shown, it will be understood that in various embodiments, multiple electrical contacts may be used. For example, one or more electrical contacts 270 may be positioned around the retaining wall 260. Such a configuration may make it easier to apply current to the electrolyte. When multiple electrical contacts 270 are positioned around the retaining wall 260, the electrical contacts 270 may be positioned at regular and / or irregular intervals around the retaining wall 260.

[0038]

[0041] To monitor material removal, the apparatus may include an optical sensor 280. The optical sensor 280 may be, for example, a camera, a depth sensor, an optical interferometer, an eddy current sensor, a machine-learnable image sensor (e.g., for detecting residues of metallic materials), or any other device for monitoring material removal. The optical interferometer may detect the topography of the metallic material. The eddy current sensor may monitor the thickness of the overburden metallic material (e.g., the metallic material extending above and / or outside of the feature). The optical sensor 280 may be positioned above the substrate 210. During operation, the field of view 285 may extend from the optical sensor 280 towards the substrate 210. The optical sensor may monitor the removal of the desired material. Additional devices, such as a processor and / or a controller, may relay information regarding the removal of material from the substrate 210. The additional device may instruct the spindle 235 to move to and contact the area of the substrate 210 where the material is to be removed. For example, if one or more sensors determine that there is copper (or other metallic material) outside of the trench to be removed, the optical sensor 280 may direct the end effector 245 to the detected location until no metallic material remains on the trench or feature of the substrate 210. In some embodiments, the relative depth or other quantity of the metal for removal may be detected. Based on this measurement, the amount of time of the end effector 245 can be set so that all of the excess metallic material is removed. Although only a single optical sensor 280 is shown, it will be understood that in various embodiments, multiple optical sensors may be used. For example, one or more optical sensors 280 may be positioned above the substrate 210 at different locations. Such a configuration may provide different fields of view / sensing angles that help avoid problems when the spindle 235 and / or the end effector 245 are positioned between a given optical sensor 280 and the substrate 210, which may make it easier to remove material from the substrate 210. When multiple optical sensors 280 are positioned above the substrate 210, the optical sensors 280 may be positioned at regular and / or irregular intervals above the substrate 210.

[0039]

[0042] During operation, the substrate 210 can be positioned upwardly within the opening of the edge ring 230 on the substrate support surface 217. By positioning the substrate 210 upwardly on the substrate support surface 217 and positioning the electrolyte on the substrate 210, hydrogen bubbles trapped on the surface of the substrate 210 can be reduced or eliminated. Further, the possibility of arching and / or warping of the substrate 210 can be reduced during operation. The upward configuration can also reduce or prevent residues on the surface of the substrate 210 during operation, such as the accumulation of residues of removed metallic materials. To clamp the substrate 210 to the substrate support surface 217, a chucking force such as a vacuum force and / or an electrostatic chucking force can be applied to the substrate 210. In some examples, in addition to clamping the substrate 210 to the substrate support surface 217, the chucking force can reduce and / or eliminate the warping of the substrate 210 such that the substrate 210 is substantially flat before starting the planarization process. The spindle 235 and the end effector 245 can be positioned on the substrate 210. The end effector 245 is positioned relative to the surface of the substrate 210 and can rotate to planarize the film on the substrate 210. Often, the spindle 235 and the end effector 245 rotate at a speed of about 60 rpm to 200 rpm, about 80 rpm to 180 rpm, about 100 rpm to 160 rpm, or about 120 rpm to 140 rpm, although other speeds are possible in various embodiments. The downward force of the end effector 245 can be adjusted by a drive mechanism based on the requirements of a particular planarization process. To prevent dishing or non-uniform removal of the material, the downward force can be negligible. For example, the force can be adjusted from about 0.1 psi to about 2.0 psi, and can be about 1.5 psi or less than about 1.5 psi, about 1.0 psi or less than about 1.0 psi, about 0.8 psi or less than about 0.8 psi, about 0.6 psi or less than about 0.6 psi, about 0.4 psi or less than about 0.4 psi, about 0.2 psi or less than about 0.2 psi, although other levels of force can be utilized in various embodiments. The end effector 245 can be aligned coaxially with the substrate 210 and can be used to create symmetric planarization of the substrate 210.In other embodiments, the end effector 245 may be offset from the central axis of the substrate 210, which may enable performing an asymmetric planarization. In some embodiments, during rotation of the end effector 245, the end effector 245 (and the spindle 235) may be translated (or swept) laterally to control the eccentricity of the end effector 245 and change the planarization pattern of the apparatus 200. Often, the lateral distance covered during the sweep is about 10 mm or less than about 10 mm, about 9 mm or less than about 9 mm, about 8 mm or less than about 8 mm, about 7 mm or less than about 7 mm, about 6 mm or less than about 6 mm, about 5 mm or less than about 5 mm, about 4 mm or less than about 4 mm, about 3 mm or less than about 3 mm, about 2 mm or less than about 2 mm, about 1 mm or less than about 1 mm, or less. The speed of the sweeping motion can be adjusted based on the start and / or the desired film thickness profile.

[0040]

[0043] Such operation of the apparatus 200 may enable uniform or substantially uniform removal of the exposed material on the surface of the substrate 210. Further, by using a spindle 235 that is laterally translatable, the apparatus 200 can be swept and / or translated in other ways to account for issues of asymmetric non-uniformity. The planarization described herein can be used in conjunction with a conventional CMP polishing process to uniformly polish the entire film surface of the substrate. For example, the planarization can be performed before and / or after conventional downward CMP polishing.

[0041]

[0044] Although mainly discussed for improving the uniformity of the film across the substrate, it will be understood that the techniques described herein can also be used in some embodiments to generate other film thickness profiles by providing the ability to adjust the planarization process without affecting the planarization of the remaining portions of the substrate.

[0042]

[0045] Figure 3 shows a schematic top view of a polishing chamber 300 according to some embodiments of the present technology. The chamber 300 can include any number of stations 305, which can be used to perform one or more polishing processes. For example, the chamber 300 can include at least about 1 station, at least about 2 stations, at least about 3 stations, at least about 4 stations, or more stations. Each station 305 can include one or more polishing systems. For example, in addition to other finishing stations 305c, the station 305 can include one or more conventional CMP systems 305a (e.g., system 100) and / or one or more electrochemical planarization devices 305b (e.g., device 200), and an upward edge planarization device. The various stations can be provided in any number, arrangement, and / or combination. As just one example, the chamber 300 can include two CMP stations 305a, one electrochemical planarization device 305b, and one finishing station 305c. The chamber 300 can include one or more robots 310 that can be used to move substrates from one station 305 to another. For example, the robot 310 can transport substrates between one of the CMP stations 305a and the electrochemical planarization device 305b.

[0043]

[0046] Figure 4 shows exemplary steps of a method 400 for planarizing a substrate according to some embodiments of the present technology. The method 400 can be performed using an electrochemical planarization device such as the electrochemical planarization device 200 described herein. The method 400 can include, in some embodiments, steps prior to planarization of the substrate. For example, prior to planarization, one or more deposition and / or etching processes, and any planarization or other process steps may be performed on the substrate. The method 400 can include some steps that can be automatically performed within the system to limit manual interaction and improve efficiency and accuracy over manual operation. The method 400 can be performed in conjunction with a conventional CMP polishing process. For example, the conventional CMP polishing process can be performed before and / or after the method 400.

[0044]

[0047] Method 400 may include, in operation 405, positioning a substrate upwardly on a substrate support surface of a chuck body within an opening defined by a retaining wall extending from the chuck body. The substrate may be clamped to the chuck body in operation 410. For example, an actuating chuck mechanism can provide vacuum chucking force and / or electrostatic chucking force to clamp and / or planarize the substrate against the substrate support surface. An electrolyte may be provided within an opening defined by the chuck body and the retaining wall in operation 415. In an embodiment, the electrolyte may be provided on an upper surface of the substrate and, in some embodiments, may cover the entire upper surface. The electrolyte may be a solution or medium containing conductive ions. The electrolyte may facilitate an electrochemical process for removing material. In operation 420, the upper surface of the substrate can be engaged with an annular end effector. This contact can form a closed circuit and enable the material to be electrochemically removed during a planarization process. In operation 425, a current may be applied to the electrolyte. The current, in conjunction with a suitable electrolyte, can drive an electrochemical reaction at a surface of the substrate exposed to the electrolyte. During operation, when a current is applied to the electrolyte, a conductive film can be removed from the surface of the substrate. Further, during operation, the current can be varied. The current can be increased, decreased, and maintained according to the location of the end effector relative to a location on the substrate. For example, the thickness of a metal profile may be asymmetric and, depending on the deposition method, a portion of the substrate may have a thicker metal profile. Thus, the current can be varied to correct for the thickness of the metal profile in various regions on the substrate.

[0045]

[0048] In operation 430, the end effector can rotate relative to the upper surface of the substrate to planarize the substrate. For example, the central axis of the end effector can be coaxial with the central axis of the substrate, while rotating the end effector relative to the upper surface of the substrate to planarize the substrate uniformly. The central axis of the end effector can be offset from the central axis of the substrate, while rotating the end effector relative to the upper surface of the substrate to planarize the problem of asymmetric film thickness non-uniformity. In some embodiments, the end effector can translate or sweep laterally across the surface of the substrate while rotating the end effector relative to the upper surface of the substrate to planarize the substrate in a desired pattern and / or to achieve a desired film thickness profile. During operation, the end effector can sweep across the substrate. Depending on the material to be removed and the thickness of the material, the dwell time of the end effector at some locations may be shorter or longer than the dwell time of the end effector at other locations. The sweeping movement of the end effector across the substrate can control the removal profile of the metal material in the radial direction. In an embodiment, the chuck body may also rotate. The metal material removal profile can be adjusted in the radial and angular directions by a combination of the sweeping of the end effector and the rotation of the chuck body. The end effector can be rotated relative to the upper surface of the substrate while an ignorable or zero downward force, such as about 2.0 psi or less than about 2.0 psi, is applied to the end effector. The magnitude of the downward force may be negligible to ensure electrochemical removal rather than mechanical removal and can be adjusted to control the planarization rate of the electrochemical planarization apparatus. Planarization by current application in the presence of an electrolyte may serve the opposite role of electroplating (i.e., removal of material versus application of material).

[0046]

[0049] The electrolyte can be delivered to the substrate continuously and / or periodically via an electrolyte delivery port. When a given planarization process is completed, the electrolyte can be removed from the apparatus, such as by discharging and / or pumping out the electrolyte via an electrolyte discharge port.

[0047]

[0050] In the above description, for the purpose of facilitating the understanding of various embodiments of the present technology, a number of detailed matters have been specified for explanatory purposes. However, it will be apparent to those skilled in the art that a particular embodiment may be practiced even without some of these detailed matters or with additional details.

[0048]

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

[0049]

[0052] When a range of values is provided, each intervening value between the upper and lower limits of that range is specifically disclosed to the smallest unit of the lower limit (unless clearly indicated otherwise in the context). Any narrower range between any of the recited values or intervening values not recited within the recited range, and any other recited values or intervening values within such recited range, are all included. The upper and lower limits of the narrower range can be included in or excluded from the range individually. Each range where either, neither, or both of the limiting values are included in the narrower range is also included in the present technology, provided that there are no limiting values specifically excluded from the recited range. When the recited range includes one or both of the limiting values, ranges excluding either or both of the included limiting values are also included.

[0050]

[0053] In this specification and the appended claims, the singular forms "a," "an," and "the" include the plural meaning (unless clearly indicated otherwise in the context). Thus, for example, when "a heater" is referred to, a plurality of such heaters are included, and when "the protrusion" is referred to, it includes references to one or more protrusions and equivalents known to those skilled in the art, and the same applies to other forms.

[0051]

[0054] Also, the terms "comprise(s) / comprising", "contain(s) / containing", and "include(s) / including" as used in this specification and the following claims are intended to specify the presence of the stated features, integers, components, or steps, but are not intended to exclude the presence or addition of one or more other features, integers, components, steps, acts, or groups.

Claims

1. A substrate electrochemical planarization apparatus, a chuck body defining a substrate support surface, a retaining wall extending from the chuck body, an electrolyte delivery port disposed radially inside the retaining wall, a spindle positionable on the chuck body, an end effector coupled to a lower end of the spindle, the end effector being conductive, an electrical contact extending from the chuck body or the retaining wall, a current source and configured such that the current source provides a current to an electrolyte inside an opening defined by the retaining wall. A substrate electrochemical planarization apparatus.

2. The substrate electrochemical planarization apparatus according to claim 1, wherein the end effector has a diameter of about 150 mm or less than about 150 mm.

3. The substrate electrochemical planarization apparatus according to claim 1, wherein the spindle is rotatable and laterally translatable relative to the chuck body.

4. The substrate electrochemical planarization apparatus according to claim 1, wherein a surface of the end effector facing the substrate support surface is flat.

5. The substrate electrochemical planarization apparatus according to claim 1, wherein the retaining wall is annular and a diameter of the end effector is smaller than an inner diameter of the retaining wall.

6. The substrate electrochemical planarization apparatus according to claim 1, further comprising an electrolyte discharge port positioned in one or both of the chuck body and the retaining wall.

7. The substrate electrochemical planarization apparatus according to claim 1, further comprising an edge ring placed on the chuck body.

8. A substrate electrochemical planarization apparatus, A chuck body defining a substrate support surface, a spindle positionable on the chuck body, a rotational drive mechanism coupled to the spindle, an end effector coupled to a lower end of the spindle, electrical contacts extending from the chuck body, a current source and wherein the current source is configured to provide current to an electrolyte within an opening defined by a retaining wall extending from the chuck body, a substrate electrochemical planarization apparatus. **Claim 9** The substrate electrochemical planarization apparatus according to claim 8, wherein the end effector comprises a conductive material. **Claim 10** The substrate electrochemical planarization apparatus according to claim 8, further comprising an edge ring placed on the chuck body, wherein an inner diameter of the edge ring is less than about 5% larger than a diameter of the substrate support surface. **Claim 11** The substrate electrochemical planarization apparatus according to claim 8, further comprising a retaining wall disposed radially outside the chuck body, wherein the retaining wall is annular and a diameter of the end effector is smaller than an inner diameter of the retaining wall. **Claim 12** a retaining wall disposed radially outside the chuck body, an electrolyte source, an electrolyte delivery port in fluid communication with the electrolyte source and disposed radially inside the retaining wall, The substrate electrochemical planarization apparatus according to claim 8, further comprising. **Claim 13** The substrate electrochemical planarization apparatus according to claim 8, further comprising an optical sensor directed towards the substrate support surface. **Claim 14** The substrate electrochemical planarization apparatus according to claim 8, wherein the substrate electrochemical planarization apparatus is disposed within a polishing chamber having a downward polishing station. **Claim 15** A method for planarizing a substrate, comprising: Positioning the substrate upwardly on a substrate support surface of the chuck body within an opening defined by a retaining wall extending from the chuck body; Clamping the substrate to the chuck body; Delivering an electrolyte to an upper surface of the substrate; Engaging the upper surface of the substrate with an end effector coupled to a lower end of a spindle; Applying a current to the electrolyte; A method comprising the above steps.

16. Rotating the end effector relative to the upper surface of the substrate while translating the spindle laterally; The method for planarizing a substrate according to claim 15, further comprising the above step.

17. Moving the end effector relative to the substrate; The method for planarizing a substrate according to claim 15, further comprising the above step.

18. The method for planarizing a substrate according to claim 15, wherein the end effector is rotated relative to the upper surface of the substrate while applying a downward force of about 2.0 psi or less to the end effector.

19. The method for planarizing a substrate according to claim 15, wherein the central axis of the end effector is offset from the central axis of the substrate while the end effector is rotated relative to the upper surface of the substrate.

20. Discharging the electrolyte from the opening through an electrolyte discharge port positioned within one or both of the chuck body and the retaining wall; The method for planarizing a substrate according to claim 15, further comprising the above step.

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