Texture of Al thin films deposited by magnetron sputtering onto epitaxial W(001)
2000 (English)In: Journal of Applied Physics, ISSN 0021-8979, Vol. 87, no 1, 168-171 p.Article in journal (Refereed) Published
Highly textured epitaxial metallizations will be required for the next generation of devices with the main driving force being a reduction in electromigration. Herein a model system of 190 nm of Al on a 140 nm layer of W grown on MgO less than 00l greater than substrates was studied. The W layer was less than 00l greater than oriented and rotated 45 degrees with respect to the MgO substrate to minimize the misfit; the remaining strain was accommodated by dislocations, evident in transmission electron microscopy images. From high-resolution x-ray diffraction (XRD) measurements, the out-of-plane lattice parameter was determined to be 3.175 Angstrom, and the in-plane parameter was 3.153 Angstrom, i.e., the W film sustained a strain resulting in a tetragonal distortion of the lattice. XRD pole figures showed that the Al had four fold symmetry and two dominant orientations, less than 016 greater than and less than 3 9 11 greater than, which were twinned with multiple placements on the epitaxial W layer. The driving force for the tilted less than 001 greater than and less than 011 greater than orientations of Al on W is due to strain minimization through lattice matching. These results show that less than 00l greater than Al deposited at ambient conditions onto W is difficult to achieve and implies that electromigration difficulties are inherent.
Place, publisher, year, edition, pages
2000. Vol. 87, no 1, 168-171 p.
IdentifiersURN: urn:nbn:se:liu:diva-53574DOI: 10.1063/1.371839OAI: oai:DiVA.org:liu-53574DiVA: diva2:289369