K. Barmak
Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
C. Cabral, Jr.
IBM T. J. Watson Research Center, Yorktown Heights, New York 10598
A.J. Kellock
IBM Almaden Research Center, San Jose, California 95120
J.M.E. Harper
Department of Physics, University of New Hampshire, Durham, New Hampshire 03824
The resistivities of as-deposited Cu(4.2Ir), Cu(2.0W), and Cu(2.2W) films are 32.2, 25.4, and 28.0 μΩcm, respectively. These resistivities are significantly higher than that for pure Cu films. After annealing the Cu(4.2Ir) film at constant heating rate to 800 °C and the two Cu(W) films to 950 °C, the resistivities reduce to 28.4, 4.3, and 5.2 μΩcm, respectively. The smaller reduction in resistivity for Cu(4.2Ir) compared with that for Cu(W) is partly a consequence of solute redissolution following precipitation. The variation of resistivity with temperature for the films and the Cu-rich end of the binary phase diagrams are used to categorize the decomposition behavior of the Cu(Ir) and Cu(W). These categories were defined by K. Barmak et al., J. Appl. Phys. 87, 2204 (2000). W is placed in category III along with V, Nb, Ta, Cr, Mo, Re, Ru, Os, B, and C. Ir most suitably belongs to Category II together with Fe and Co.