DIRECTED SPUTTER-DEPOSITION OF ALCU - FILM MICROSTRUCTURE AND MICROCHEMISTRY

The microstructure and microchemistry of AlCu films deposited onto unh eated oxidized Si(001) substrates by two recently developed directiona l Sputtering techniques, collimated magnetron sputter deposition (CMSD ) and ionized magnetron sputter deposition (IMSD), have been investiga ted using Rutherford backscattering spectroscopy, x-ray diffraction (X RD), plan-view transmission electron microscopy (TEM), cross-sectional TEM (XTEM); and scanning TEM (STEM). Both sets of films had essential ly the same aver age compositions. as the alloy targets while exhibiti ng dense columnar microstructures with (111) preferred orientation, re latively abrupt film/substrate interfaces; and no indication of surfac e faceting. Microstructure evolution pathways, however, were quite dif ferent. IMSD layers exhibited competitive column growth resulting in a degree of (111) orientation which was more than an order of magnitude larger than that found in corresponding CMSD films and, for thicker l ayers (greater than or similar to mu m), larger average column sizes. The IMSD films also had a much smaller spread in the azimuthal distrib ution of (111)-oriented columns. XRD line broadening analyses and TEM/ XTEM examinations revealed that IMSD layers contained inhomogeneous st rain due to residual ion-irradiation-induced defects and, in the upper near-surface region, Al2Cu precipitates while CMSD layers appeared de fect-free in TEM/XTEM images. The IMSD films were slightly tensile (+0 .13+/-0.01 GPa) and the CMSD films were slightly compressive (-0.18+/- 0.06 GPa).