US 7,067,902 B2Granted

Building metal pillars in a chip for structure support

AssigneeInternational Business Machines Corporation

InventorsHabib Hichri, Xiao H. Liu, Vincent J. McGahay, Conal E. Murray, Jawahar P. Nayak, Thomas M. Shaw

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Abstract

Stacked via pillars, such as metal via pillars, are provided at different and designated locations in IC chips to support the chip structure during processing and any related processing stresses such as thermal and mechanical stresses. These stacked via pillars connect and extend from a base substrate of the strip to a top oxide cap of the chip. The primary purpose of the stacked via pillars is to hold the chip structure together to accommodate any radial deformations and also to relieve any stress, thermal and/or mechanical, build-up during processing or reliability testing. The stacked via pillars are generally not electrically connected to any active lines or vias, however in some embodiments the stacked via pillars can provide an additional function of providing an electrical connection in the chip.

Claims10

Dependent claims

An integrated circuit (IC) chip comprising:

the chip comprising a base substrate, a plurality of stacked levels of conductive metallurgy and low-k dielectric material fabricated over the substrate, the conductive metallurgy including active electrical lines, with the conductive metallurgy in different levels being connected by conductive metallurgy vias, and being capped by a top oxide cap covering the plurality of stacked levels;
a plurality of stacked via pillars positioned at a plurality of spaced locations in the chip, wherein the plurality of stacked via pillars extend completely from the base substrate of the chip to the top oxide cap of the chip, and at least a portion of the plurality of stacked via pillars are not electrically connected to any of the active electrical lines or vias, wherein the plurality of stacked via pillars support the structural stability of the chip design to accommodate deformations during any thermal and/or mechanical stresses.

Dependencies are inferred from the claim text.