Methods and structures to facilitate through-silicon vias

Abstract

In some implementations, a metal pad for capturing or interfacing with through-silicon vias has a plurality of openings through it. Another metal pad on an upper level can also include a plurality of openings. The metal pads are vertically aligned and the placement of the openings in each metal pad is such that the openings are laterally offset and substantially do not directly overlie or underlie one another. As seen in a top-down view, the through-silicon via etch may 'see' a metal etch stop that extends continuously across the width of the via, although different portions of the etch stop may be distributed on different vertical levels due to the presence of openings in the metal pads. The openings in the metal pads facilitate integrated circuit fabrication their respective levels and the aggregate structure formed by the metal pads provides an effective etch stop for the through-silicon via etch.