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Void formation in the Cu layer during thermal treatment of SiN x /Cu/Ta 73 Si 27 /SiO 2 /Si systems
Author(s) -
Hübner R.,
Reiche R.,
Hecker M.,
Mattern N.,
Hoffmann V.,
Wetzig K.,
Heuer H.,
Wenzel Ch.,
Engelmann H.J.,
Zschech E.
Publication year - 2005
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200410316
Subject(s) - annealing (glass) , passivation , diffusion barrier , auger electron spectroscopy , copper , amorphous solid , analytical chemistry (journal) , transmission electron microscopy , materials science , crystallization , thermal stability , atmospheric temperature range , scanning electron microscope , crystallography , chemistry , metallurgy , layer (electronics) , nanotechnology , composite material , physics , organic chemistry , chromatography , meteorology , nuclear physics
The thermal stability of a SiN x passivation layer and its influence on the annealing behavior of an amorphous Ta 73 Si 27 diffusion barrier deposited between copper and SiO 2 were analyzed by X‐ray diffraction, glow discharge optical emission spectroscopy, Auger electron spectroscopy, scanning electron microscopy, and transmission electron microscopy. During heat treatment at a temperature T an = 500 °C, diffusion of Cu atoms out of the Cu metallization into the SiN x passivation occurs. The Cu diffusion intensifies with increasing annealing temperature and annealing time and seems to be a necessary precondition for a defect formation process observed within the Cu metallization. Depending on the chemical composition of the SiN x /Cu interface, voids in the μm‐range can be formed within the Cu film. Compared to an unpassivated sample, heat treatment leads to a reduced diffusion of Ta atoms from the barrier through the copper into the SiN x /Cu interface. The barrier crystallization process into Ta 5 Si 3 occurring during annealing at T an = 600 °C is principally not affected by the presence of a SiN x passivation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)