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2015
Conference Paper
Titel
High temperature reliability of Ta-based and TiW-based diffusion barriers
Abstract
Two types of diffusion barriers, Ta-based and TiW-based, with Ni layer on top were investigated to determine their reliability for high temperature applications up to 600 degrees C. Both barriers were deposited in form of stacked layer on 200 mm silicon wafers using standard production tools for physical vapor deposition. In order to investigate their reliability, the barriers have been annealed inside a vacuum chamber for 24 h up to 600 degrees C. Before and after annealing, three ex situ analysis techniques consisting X-ray diffraction method, 4-probe measurement method, and transmission electron microscopy (TEM) have been applied. After annealing for 24 h at 600 degrees C, Ni-Ta and Ni-TiW phases from Ta- and TiW-based barriers, respectively, were determined and both barriers showed a tolerable increase of sheet resistance. TEM analysis determined no diffusion of materials into the substrate using both barriers and this result was confirmed by XRD analysis.