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11th Edition: All-Optical, Non-Contact Metrology for Characterising CMP of Copper Films |
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Feb 03, 2005 at 02:45 PM |
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MATTHEW BANET, MICHAEL JOFFE, MICHAEL GOSTEIN, ALEX MAZNEV, ROBIN SACCO & FRANÇOISE QUEROMES,
Philips Analytical, Natick, MA, USA ABSTRACT
The
semiconductor industry is gradually replacing aluminium with copper as
the metal of choice for interconnects in ICs. Copper interconnects are
formed in a dual-Damascene structure that relies on chemical-mechanical
polishing (CMP) to remove unwanted copper, leaving only a network of
copper-filled Damascene trenches. Unfortunately, CMP of copper often
leaves structures that have defects such as non-uniform thickness,
rounding, dishing and erosion.
To improve polishing performance on
copper films and meet CMP's metrology needs, Philips Analytical
presents a cost-effective solution for copper CMP process control. This
solution features a novel, opto-acoustic measurement technique, called
"impulsive stimulated thermal scattering" (ISTS), that can be used to
precisely and rapidly measure the thickness of metal films. This paper
describes the ISTS technique and its use for characterising CMP of
blanket copper films and CMP of copper Damascene structures.
 All-Optical, Non-Contact Metrology for Characterising CMP of Copper Films
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Wafer Processing 