Title :
Properties of amorphous AlCuY alloy metallizations
Author :
Berger, L. ; Mrosk, J.W. ; Ettl, C. ; Fecht, H.J. ; Flege, S. ; Hahn, H. ; Wolff, U.
Author_Institution :
Div. of Mater., Ulm Univ., Germany
fDate :
6/21/1905 12:00:00 AM
Abstract :
Amorphous metal alloys are ideally suited for interconnects in micro-electromechanical systems (MEMS) because of their resistance against migration and diffusion, and their stability in chemically aggressive environments, which should both lead to a substantial improvement of lifetime and reliability of robust sensors. Amorphous aluminium alloy metallizations are especially promising for surface acoustic wave (SAW) sensors, where the interconnects are exposed to considerable mechanical strains. In this work, first experimental results for amorphous 400 nm Al84Cu4Y12 alloy thin films deposited on single crystal LiTaO3 piezoelectric substrates at room temperature (R.T.) by ultra-high vacuum (UHV) electron beam evaporation will be presented. The composition of the films was validated by Rutherford backscattering (RBS) spectroscopy, and their amorphous structure was confirmed by X-ray diffraction (XRD) analysis. The roughness and hardness of the metallization, both important parameters for wire bonding, were investigated by scanning probe microscopy (SPM) and depth-sensing nanoindentation. The electrical resistivity was determined by four-point probe measurements. The amorphous films were annealed in UHV, and their crystallization temperature Tx was investigated by XRD
Keywords :
aluminium alloys; amorphous state; copper alloys; electron beam deposition; metallic thin films; metallisation; yttrium alloys; Al84Cu4Y12; LiTaO3; Rutherford backscattering spectroscopy; X-ray diffraction; amorphous metal alloy thin film; annealing; crystallization temperature; electrical resistivity; hardness; interconnect; mechanical strain; metallization; microelectromechanical system; nanoindentation; room temperature deposition; roughness; scanning probe microscopy; single crystal piezoelectric substrate; surface acoustic wave sensor; ultra-high vacuum electron beam evaporation; wire bonding; Acoustic sensors; Aluminum alloys; Amorphous materials; Chemical sensors; Mechanical sensors; Metallization; Piezoelectric films; Robust stability; Surface acoustic waves; Temperature;
Conference_Titel :
Industrial Electronics Society, 1999. IECON '99 Proceedings. The 25th Annual Conference of the IEEE
Conference_Location :
San Jose, CA
Print_ISBN :
0-7803-5735-3
DOI :
10.1109/IECON.1999.822169
