High aspect ratio electroplated structures and anisotropic electroplating processes

A method for manufacturing a metal structure comprising:

• providing a substrate having a first trace having an initial height to width aspect ratio, wherein a first dielectric layer is formed using a thin dielectric process disposed over the substrate;
• electroplating a metal crown on at least the first trace to form the metal crown with a final height to width aspect ratio greater than the initial height to width aspect ratio of the first trace, wherein the metal crown is formed over at least a portion of the first trace on a top surface and sidewalls of the first trace, wherein a distance between the first trace to a second trace disposed on the substrate tunes an impedance of the first trace, wherein the first dielectric layer fills spaces between the first trace and the second trace and provides a coating over the first trace and the second trace, wherein the electroplating comprises:
• adjusting a current density based on an amount of copper and/or an amount of leveler additive to the plating solution included in a plating bath, wherein the metal crown is selectively formed over at least the portion of the first trace based on a concentration of a metal in the plating bath or a current density of the plating bath;
• forming at least a third trace and a fourth trace over the first dielectric layer;
• and
• forming a second dielectric layer over the third trace and the fourth trace using the thin dielectric process to fill spaces between the third trace and the fourth trace and coat over the third trace and the fourth trace, wherein a thickness of the second dielectric layer between a top of the second dielectric layer and a top of the third trace and the fourth trace is less than a thickness of the first dielectric layer between the first dielectric layer and the substrate.