Exemplary methods of electroplating include contacting a patterned substrate with a plating bath in an electroplating chamber, where the pattern substrate includes at least one opening having a bottom surface and one or more sidewall surfaces. The methods may further include forming a nanotwin-containing metal material in the at least one opening. The metal material may be formed by two or more cycles that include delivering a forward current from a power supply through the plating bath of the electroplating chamber for a first period of time, plating a first amount of the metal on the bottom surface of the opening on the patterned substrate and a second amount of the metal on the sidewall surfaces of the opening, and delivering a reverse current from the power supply through the plating bath of the electroplating chamber to remove some of the metal plated in the opening on the patterned substrate.

Exemplary methods of electroplating may include providing a patterned substrate having at least one opening, where the opening includes one or more sidewalls and a bottom surface. The methods may also include plating a first portion of ruthenium-containing material on the bottom surface of the opening at a first deposition rate and a second portion of ruthenium-containing material on the sidewalls of the opening at a second deposition rate, where the first deposition rate is greater than the second deposition rate. The methods may be used to make integrated circuit devices that include void-free, electrically-conductive lines and columns of ruthenium-containing materials.

In certain aspects, a coated steel substrate comprises a single or multiple-layer electroplated aluminum coating over a steel substrate. The multiple-layer electroplated aluminum coating comprises one or more porous layers and one or more compact layers. The one or more porous layers comprise a material selected from a group consisting of aluminum and aluminum alloys. The one or more compact layers comprise a material selected from a group consisting of aluminum and aluminum alloys. In certain aspects, a method of depositing a multiple-layer aluminum coating over a steel substrate includes electroplating one or more porous aluminum layers over the steel substrate. The one or more porous aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys. One or more compact aluminum layers are electroplated over the steel substrate. The one or more compact aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys.

In certain aspects, a coated steel substrate comprises a single or multiple-layer electroplated aluminum coating over a steel substrate. The multiple-layer electroplated aluminum coating comprises one or more porous layers and one or more compact layers. The one or more porous layers comprise a material selected from a group consisting of aluminum and aluminum alloys. The one or more compact layers comprise a material selected from a group consisting of aluminum and aluminum alloys. In certain aspects, a method of depositing a multiple-layer aluminum coating over a steel substrate includes electroplating one or more porous aluminum layers over the steel substrate. The one or more porous aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys. One or more compact aluminum layers are electroplated over the steel substrate. The one or more compact aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys.

A method for producing a structure, comprising providing a Composite Conductive Substrate (CCS) with a conductive layer, a non-conductive layer and a release layer, implemented on top of the conductive layer; determining an empty conductive pattern for each layer of the structure; printing a layer of non-conductive matter on the CCS, such that the conductive pattern of the first layer left empty from the non-conductive matter; on top of the release layer, below which the conductive layer is implemented, filling the empty conductive pattern with conductive matter by electroplating; peeling the filled conductive matter or peeling the filled conductive matter and the printed non-conductive matter, from the conductive layer of the CCS.

A structure includes a copper or copper alloy plating layer, in which Kirkendall void formation is suppressed. The copper or copper alloy plating layer is formed by electroplating at a prescribed first cathode current density by using a copper or copper alloy electroplating bath and then completing the electroplating after the first cathode current density is changed to a lower second cathode current density. The first cathode current density is a single cathode current density in the electroplating at this current density or an average cathode current density in the electroplating by combining plural cathode current densities. The first cathode current density is at lowest 5 A/dm.sup.2. A layer formed by changing the first cathode current density to the second cathode current density is a surface layer part of the copper or copper alloy plating layer, which can have a thickness of 0.05 μm to 15 μm.

A structure includes a copper or copper alloy plating layer, in which Kirkendall void formation is suppressed. The copper or copper alloy plating layer is formed by electroplating at a prescribed first cathode current density by using a copper or copper alloy electroplating bath and then completing the electroplating after the first cathode current density is changed to a lower second cathode current density. The first cathode current density is a single cathode current density in the electroplating at this current density or an average cathode current density in the electroplating by combining plural cathode current densities. The first cathode current density is at lowest 5 A/dm.sup.2. A layer formed by changing the first cathode current density to the second cathode current density is a surface layer part of the copper or copper alloy plating layer, which can have a thickness of 0.05 μm to 15 μm.

A method of making a catalyst layer of a membrane electrode assembly (MEA) for a polymer electrolyte membrane fuel cell includes the step of preparing a porous buckypaper layer comprising at least one selected from the group consisting of carbon nanofibers and carbon nanotubes. Platinum group metal nanoparticles are deposited in a liquid solution on an outer surface of the buckypaper to create a platinum group metal nanoparticle buckypaper. A proton conducting electrolyte is deposited on the platinum group metal nanoparticles by electrophoretic deposition to create a proton-conducting layer on the an outer surface of the platinum nanoparticles. An additional proton-conducting layer is deposited by contacting the platinum group metal nanoparticle buckypaper with a liquid proton-conducting composition in a solvent. The platinum group metal nanoparticle buckypaper is dried to remove the solvent. A membrane electrode assembly for a polymer electrolyte membrane fuel cell is also disclosed.

A method of making a catalyst layer of a membrane electrode assembly (MEA) for a polymer electrolyte membrane fuel cell includes the step of preparing a porous buckypaper layer comprising at least one selected from the group consisting of carbon nanofibers and carbon nanotubes. Platinum group metal nanoparticles are deposited in a liquid solution on an outer surface of the buckypaper to create a platinum group metal nanoparticle buckypaper. A proton conducting electrolyte is deposited on the platinum group metal nanoparticles by electrophoretic deposition to create a proton-conducting layer on the an outer surface of the platinum nanoparticles. An additional proton-conducting layer is deposited by contacting the platinum group metal nanoparticle buckypaper with a liquid proton-conducting composition in a solvent. The platinum group metal nanoparticle buckypaper is dried to remove the solvent. A membrane electrode assembly for a polymer electrolyte membrane fuel cell is also disclosed.

A Ni-plated steel sheet according to an aspect of the present invention includes: a base steel sheet; an Fe—Ni diffusion alloy region disposed on the base steel sheet; and a Ni plating region disposed on the Fe—Ni diffusion alloy region, in which an average equivalent circle diameter of crystal grains made of Ni (fcc) in the Ni plating region measured in a cross section perpendicular to a rolled surface of the base steel sheet is 0.2 to 4.0 μm.