Via structure and method for its fabrication

摘要

In a preferred embodiment of the invention, the via comprises one or more stacks, each stack comprising a seed layer of a first electrically conducting material formed on a smooth surface; a trace of a second electrically material that is electroplated on the seed layer; a column in electrical contact with the trace, the column comprising a third electrically conducting material that is electroplated on the trace; and an insulating material on the substrate and trace, the insulating material having a smooth upper surface in which the column is exposed. Additional vias may be stacked in tiers one on top of the other with the seed layer of one via making non-rectifying electrical contact with the exposed column of the via below it. Methods for forming the via structure are also disclosed.

主权项

1. A method for forming a via comprising:
forming a first seed layer on an upper surface of a substrate, the first seed layer comprising a layer of a first electrically conducting material; forming a first electrically conducting trace on the first seed layer by electroplating a second electrically conducting material on the first seed layer; forming a first column in electrical contact with the first trace by electroplating a third electrically conducting material in contact with the first trace; removing the first seed layer where the first seed layer does not underlie the first trace; forming an insulating layer on the first trace, the first column and the upper surface of the substrate; forming a smooth upper surface on the insulating layer in which the first column is exposed; forming a second seed layer, wherein the second seed layer is electrically conductive; forming a second electrically conductive trace on the second seed layer; and forming a second column in electrical contact with the second trace, wherein the second column is electrically conductive, wherein the second seed layer is in electrical connection with the first column, and wherein the second column is aligned with the first column along a vertical axis that is perpendicular to the upper surface of the substrate.