Abstract: Disclosed are alkaline electrodeposition solutions and apparatus and methods for using such solutions to electroplate metal. During electroplating, the solutions may produce superconformal fill of metal in features such as features having a critical dimension of about 20 nm or less. The metal electroplating process may be used during integrated circuit fabrication. For example, it may be used to fill trenches and vias in partially fabricated integrated circuits. The electroplated metal may be copper. The copper may be electroplated on a substrate material that is less noble than copper.

Abstract: Various embodiments relate to methods, apparatus, and systems for forming an interconnect structure, or a portion thereof. The method may include contacting the substrate with a functionalization bath comprising a first solvent and a functionalization reactant to form a modified first material, and then depositing a second material on the modified first material through electroless plating, electroplating, chemical vapor deposition, or atomic layer deposition. The first material may be a dielectric material, a barrier layer, or a liner, and the second material may be a barrier layer or a barrier layer precursor, a liner, a seed layer, or a conductive metal that forms the interconnect of the interconnect structure, according to various embodiments.

Abstract: Disclosed are apparatus, systems, and methods for electroplating cobalt, nickel, and alloys thereof in interconnect features of partially or fully fabricated electronic devices. During electroplating, cobalt, nickel, or alloys thereof fill features by a bottom up electrofill mechanism. Examples of features that may be electrofilled with cobalt, nickel, or alloys thereof include micro TSVs, contacts for devices, and certain gates for transistors. Electroplating apparatus may include electroplating cells along with one or more instances of each of a post-electrofill module, an anneal chamber, a plasma pretreatment module, and a substrate pre-wetting module.

Abstract: An interconnect structure of a semiconductor device includes a conductive via and a barrier layer lining an interface between a dielectric layer and the conductive via. The barrier layer is selectively deposited along sidewalls of a recess formed in a dielectric layer. The conductive via is formed by selectively electroplating electrically conductive material such as rhodium, iridium, or platinum in an opening of the recess, where the conductive via is grown upwards from an exposed metal surface at a bottom of the recess. The conductive via includes an electrically conductive material having a low electron mean free path, low electrical resistivity, and high melting point. The interconnect structure of the semiconductor device has reduced via resistance and improved resistance to electromigration and/or stress migration.

Abstract: A protective layer is formed over a copper seed layer on a semiconductor substrate prior to electroplating. The protective layer is capable of protecting the copper seed layer from oxidation and from dissolution in an electrolyte during initial phases of electroplating. The protective layer, in some embodiments, prevents the copper seed layer from contacting atmosphere, and from being oxidized by atmospheric oxygen and/or moisture. The protective layer contains a metal that is less noble than copper (e.g., cobalt), where the metal can be in an oxidized form that is readily soluble in a plating liquid. In one embodiment a protective cobalt layer is formed by depositing cobalt metal by chemical vapor deposition over copper seed layer without exposing the copper seed layer to atmosphere, followed by subsequent oxidation of cobalt to cobalt oxide that occurs after the substrate is exposed to atmosphere. The resulting protective layer is dissolved during electroplating.

Abstract: Tungsten-containing metal films may be deposited in recessed features of semiconductor substrates by electrodeposition. The tungsten-containing metal film is electrodeposited under conditions so that the tunsten-containing metal film is free or substantially free of oxide. Conditions are optimized during electrodeposition for pH, tungsten concentration, and current density, among other parameters. The tungsten-containing metal film may include cobalt tungsten alloy, cobalt nickel tungsten alloy, or nickel tungsten alloy, where a tungsten content in the tungsten-containing metal film is between about 1-20 atomic %.

Abstract: Methods and apparatus for determining whether a substrate includes an unacceptably high amount of oxide on its surface are described. The substrate is typically a substrate that is to be electroplated. The determination may be made directly in an electroplating apparatus, during an initial portion of an electroplating process. The determination may involve immersing the substrate in electrolyte with a particular applied voltage or applied current provided during or soon after immersion, and recording a current response or voltage response over this same timeframe. The applied current or applied voltage may be zero or non-zero. By comparing the current response or voltage response to a threshold current, threshold voltage, or threshold time, it can be determined whether the substrate included an unacceptably high amount of oxide on its surface. The threshold current, threshold voltage, and/or threshold time may be selected based on a calibration procedure.

Abstract: Embodiments herein relate to methods, apparatus, and systems for electroplating metal into recessed features using a superconformal fill mechanism that provides relatively faster plating within a feature and relatively slower plating in the field region. Moreover, within the feature, plating occurs faster toward the bottom of the feature compared to the top of the feature. The result is that the feature is filled with metal from the bottom upwards, resulting in a high quality fill without the formation of seams or voids, defects that are likely where a conformal fill mechanism is used. The superconformal fill mechanism relies on the presence of a sacrificial oxidant molecule that is used to develop a differential current efficiency within the feature compared to the field region. Various plating conditions are balanced against one another to ensure that the feature fills from the bottom upwards. No organic plating additives are necessary, though plating additives can be used to improve the process.

Abstract: Void-free bottom-up fill of copper in features is achieved on non-copper liner layers. A non-copper liner layer has a higher resistivity than copper. An electroplating solution for plating copper on a non-copper liner layer includes a low copper concentration, high pH, organic additives, and bromide ions as a copper complexing agent. The high pH and the bromide ions do not interfere with the activity of the organic additives. In some implementations, the concentration of copper ions is between about 0.2 g/L and about 10 g/L, a concentration of sulfuric acid is between about 0.1 g/L and about 10 g/L, and a concentration of the bromide ions is between about 20 mg/L and about 240 mg/L. In some implementations, the electroplating solution further includes chloride ions as an additional copper complexing agent at a concentration between about 0.1 mg/L and about 100 mg/L.

Abstract: In one aspect, an apparatus includes a plating cell, a degassing device configured to remove oxygen from the plating solution prior to the plating solution flowing into the plating cell; an oxidation station configured to increase an oxidizing strength of the plating solution after the plating solution flows out of the plating cell; and a controller. The controller includes program instructions for causing a process that includes operations of: reducing an oxygen concentration of the plating solution where the plating solution contains a plating accelerator; then, contacting a wafer substrate with the plating solution having reduced oxygen concentration and electroplating a metal such that the electroplating causes a net conversion of the accelerator to a less-oxidized accelerator species within the plating cell; then increasing the oxidizing strength of the plating solution causing a net re-conversion of the less-oxidized accelerator species back to the accelerator outside the plating cell.

Abstract: Methods and apparatus for determining whether a substrate includes an unacceptably high amount of oxide on its surface are described. The substrate is typically a substrate that is to be electroplated. The determination may be made directly in an electroplating apparatus, during an initial portion of an electroplating process. The determination may involve immersing the substrate in electrolyte with a particular applied voltage or applied current provided during or soon after immersion, and recording a current response or voltage response over this same timeframe. The applied current or applied voltage may be zero or non-zero. By comparing the current response or voltage response to a threshold current, threshold voltage, or threshold time, it can be determined whether the substrate included an unacceptably high amount of oxide on its surface. The threshold current, threshold voltage, and/or threshold time may be selected based on a calibration procedure.

Abstract: An electroplating apparatus for filling recessed features on a semiconductor substrate includes a vessel configured to maintain a concentrated electroplating solution at a temperature of at least about 40° C., wherein the solution would have formed a precipitate at 20° C. This vessel is in fluidic communication with an electroplating cell configured for bringing the concentrated electrolyte in contact with the semiconductor substrate at a temperature of at least about 40° C., or the vessel is the electroplating cell. In order to prevent precipitation of metal salts from the electrolyte, the apparatus further includes a controller having program instructions for adding a diluent to the concentrated electroplating solution in the vessel to avoid precipitation of a salt from the concentrated electroplating solution in response to a signal indicating that the electrolyte is at risk of precipitation.

Abstract: Methods and apparatus for determining whether a substrate includes an unacceptably high amount of oxide on its surface are described. The substrate is typically a substrate that is to be electroplated. The determination may be made directly in an electroplating apparatus, during an initial portion of an electroplating process. The determination may involve immersing the substrate in electrolyte with a particular applied voltage or applied current provided during or soon after immersion, and recording a current response or voltage response over this same timeframe. The applied current or applied voltage may be zero or non-zero. By comparing the current response or voltage response to a threshold current, threshold voltage, or threshold time, it can be determined whether the substrate included an unacceptably high amount of oxide on its surface. The threshold current, threshold voltage, and/or threshold time may be selected based on a calibration procedure.

Abstract: Embodiments herein relate to methods, apparatus, and systems for electroplating metal into recessed features using a superconformal fill mechanism that provides relatively faster plating within a feature and relatively slower plating in the field region. Moreover, within the feature, plating occurs faster toward the bottom of the feature compared to the top of the feature. The result is that the feature is filled with metal from the bottom upwards, resulting in a high quality fill without the formation of seams or voids, defects that are likely where a conformal fill mechanism is used. The superconformal fill mechanism relies on the presence of a sacrificial oxidant molecule that is used to develop a differential current efficiency within the feature compared to the field region. Various plating conditions are balanced against one another to ensure that the feature fills from the bottom upwards. No organic plating additives are necessary, though plating additives can be used to improve the process.

Abstract: Various embodiments herein relate to methods and apparatus for electroplating metal on a substrate. In many cases, an electroplating process may be monitored to ensure that it is operating within a pre-defined processing window. This monitoring may involve application of a controlled potential between the substrate and a reference electrode after the electroplating process is substantially complete (e.g., after recessed features on the substrate are substantially filled). The current delivered to the substrate during application of the controlled potential is monitored, and a peak current is determined. This peak current, often referred to herein as the potential-controlled exit peak current, can be compared against an expected range to determine whether the electroplating process is operating as desired.

Abstract: Embodiments herein relate to methods, apparatus, and systems for electroplating metal into recessed features using a superconformal fill mechanism that provides relatively faster plating within a feature and relatively slower plating in the field region. Moreover, within the feature, plating occurs faster toward the bottom of the feature compared to the top of the feature. The result is that the feature is filled with metal from the bottom upwards, resulting in a high quality fill without the formation of seams or voids, defects that are likely where a conformal fill mechanism is used. The superconformal fill mechanism relies on the presence of a sacrificial oxidant molecule that is used to develop a differential current efficiency within the feature compared to the field region. Various plating conditions are balanced against one another to ensure that the feature fills from the bottom upwards. No organic plating additives are necessary, though plating additives can be used to improve the process.

Abstract: Certain embodiments herein relate to a method of electroplating copper into damascene features using a low copper concentration electrolyte having less than about 10 g/L copper ions and about 2-15 g/L acid. Using the low copper electrolyte produces a relatively high overpotential on the plating substrate surface, allowing for a slow plating process with few fill defects. The low copper electrolyte may have a relatively high cloud point.

Abstract: Method and apparatus for reducing metal oxide surfaces to modified metal surfaces and cooling the metal surfaces are disclosed. By exposing a metal oxide surface to remote plasma, the metal oxide surface on a substrate can be reduced to pure metal. A remote plasma apparatus can treat the metal oxide surface as well as actively cool, load/unload, and move the substrate within a single standalone apparatus. The remote plasma apparatus can be configured to actively cool the substrate during and/or after reducing the metal oxide to pure metal using an active cooling system. The active cooling system can include one or more of an actively cooled pedestal, an actively cooled showerhead, and one or more cooling gas inlets for delivering cooling gas to cool the substrate.

Abstract: Methods and apparatus for determining whether a substrate includes an unacceptably high amount of oxide on its surface are described. The substrate is typically a substrate that is to be electroplated. The determination may be made directly in an electroplating apparatus, during an initial portion of an electroplating process. The determination may involve immersing the substrate in electrolyte with a particular applied voltage or applied current provided during or soon after immersion, and recording a current response or voltage response over this same timeframe. The applied current or applied voltage may be zero or non-zero. By comparing the current response or voltage response to a threshold current, threshold voltage, or threshold time, it can be determined whether the substrate included an unacceptably high amount of oxide on its surface. The threshold current, threshold voltage, and/or threshold time may be selected based on a calibration procedure.

Abstract: Embodiments herein relate to methods, apparatus, and systems for electroplating metal into recessed features using a superconformal fill mechanism that provides relatively faster plating within a feature and relatively slower plating in the field region. Moreover, within the feature, plating occurs faster toward the bottom of the feature compared to the top of the feature. The result is that the feature is filled with metal from the bottom upwards, resulting in a high quality fill without the formation of seams or voids, defects that are likely where a conformal fill mechanism is used. The superconformal fill mechanism relies on the presence of a sacrificial oxidant molecule that is used to develop a differential current efficiency within the feature compared to the field region. Various plating conditions are balanced against one another to ensure that the feature fills from the bottom upwards. No organic plating additives are necessary, though plating additives can be used to improve the process.