AVS 53rd International Symposium
    Manufacturing Science and Technology Thursday Sessions
       Session MS-ThA

Invited Paper MS-ThA1
Three-dimensional Imaging of Nano-Voids in Copper Interconnects using Incoherent Bright Field Tomography

Thursday, November 16, 2006, 2:00 pm, Room 2018

Session: Sensors, Metrology, and Control
Presenter: D.A. Muller, Cornell University
Authors: P. Ercius, Cornell University
M. Weyland, Cornell University
D.A. Muller, Cornell University
L.M. Gignac, Thomas J. Watson Research Center
Correspondent: Click to Email
As integrated circuits have shrunk, conventional electron microscopies have proven inadequate for imaging complicated interconnect structures due to the overlap of features in projection. These techniques produce transmission functions with a non-monotonic dependence of intensity on thickness for common microelectronic materials, making them unsuitable for tomography. We report the use of an incoherent bright field imaging technique in a scanning transmission electron microscope optimized for the three-dimensional reconstruction of thick copper microelectronic structures. Predictable behavior of the signal in samples up to ~1 micron thick allows us to reconstruct and quantify the shape and volume of stress voids within Ta-lined interconnects as well as analyze the liner roughness in 3 dimensions.