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Study of the effect of dielectric porosity on the stress in advanced Cu/low-k interconnects using x-ray diffraction

Lookup NU author(s): Dr Alton Horsfall, Professor Anthony O'Neill



This is the final published version of an article that has been published in its final definitive form by American Institute of Physics, 2009.

For re-use rights please refer to the publisher's terms and conditions.


High intensity x-rays at an advanced light facility were used to probe the strained atomic spacing of Cu interconnects embedded in ultralow-k dielectrics of different porosities. The assumption that the strain-free atomic spacing of a thin film can be extrapolated from a relationship based on the material stiffness coefficients used in literature is tested and demonstrated experimentally using a series of blanket wafers. This is used to calculate the stress of 100 nm interconnects. High porosity materials show in-plane relaxation reducing the stress. The air gap architecture is shown to provide little constraint with the lowest Cu stress.

Publication metadata

Author(s): Wilson CJ, Zhao C, Zhao L, Metzger TH, Tokei Z, Croes K, Pantouvaki M, Beyer GP, Horsfall AB, O'Neill AG

Publication type: Article

Publication status: Published

Journal: Applied Physics Letters

Year: 2009

Volume: 94

Issue: 18

Date deposited: 15/09/2016

ISSN (print): 0003-6951

ISSN (electronic): 1077-3118

Publisher: American Institute of Physics


DOI: 10.1063/1.3133345


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Funder referenceFunder name
IST-026828European Commission's Information Society Technologies