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The properties of thermal hillocks as a function of linewidth and process parameter in Al-on-chemical-vapor-deposited W films

  • Carey A. Pico (a1) and Tom D. Bonifield (a1)


The formation of hillocks has been studied as a function of process parameter in patterned and unpatterned Al98.5wt. %Si1.0wt. %Cu0.5wt. % films deposited on chemical-vapor-deposited W-coated substrates. The effects of linewidth, substrate temperature during film deposition, and sintering time and temperature on hillock size were investigated. Three types of hillocks are found: the “surface hillocks”, the “side hillock”, and the “line hillock”. These are further classified by their shapes. The surface hillock and side hillock, which have been seen previously, form on patterned metal lines having linewidths greater than the larger Al alloy grain sizes (~3 μm). None is seen on linewidths between 0.9 and 2 μm where long-range grain boundary diffusion cannot occur. A new type of hillock, the line hillock, is seen to occur on metal structures having linewidths of 0.6 μm. The line hillock is inconsistent with the current understanding of hillock formation and may present severe restrictions on the downsizing of ultra-large-scale integrated devices.



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1Scoggan, G. A.Agarwala, B. N.Peressini, P. P. and Brouillard, A.IEEE 13th Ann. Proc. Rel. Phys. 151 (1975).
2Vaiday, S.Fraser, D.B. and Sinha, A.K.IEEE 18th Int. Rel. Phys. Symp. 165 (1980).
3Murakami, M.CRC Critical Reviews in Solid State and Materials Sciences 11, 317 (1984).
4Jackson, M.S. and Li, C.Y.Acta Metall. 30, 1993 (1982).
5Faith, T.J.J. Appl. Phys. 52, 4630 (1981).
6Herman, D. S.Schuster, M.A. and Gerber, R. M.J. Vac. Sci. Technol. 9, 515 (1971).
7Hinode, K.Owada, N.Nishida, T. and Mukai, K.J. Vac. Sci. Technol. B5, 518 (1987).
8Pico, C.A. and Bonifield, T.D.Proc. 8th Int. VLSI Multilevel Interconnect Conf. 256 (1991).
9Pico, C.A. and Bonifield, T.D.J. Mater. Res. 6, 1817 (1991).
10Pico, C.A. and Bonifield, T.D.J. Mater. Res. 8, 1001 (1993).
11Chaudari, P.J. Appl. Phys. 45, 4339 (1974).
12Pennebaker, W.B.J. Appl. Phys. 40, 394 (1969).
13Sharma, S.K. and Spitz, J.Thin Solid Films 65, 339 (1980).
14Presland, A. E. B.Price, G. L. and Trimm, D. L.Surf. Sci. 29, 424 (1972).
15Chang, C.Y.Vook, R.W. and Lee, Y.C.Thin Solid Films 181, 57 (1989).
16Chang, C.Y. and Vook, R.W.J. Mater. Res. 4, 1172 (1989).
17Caswell, H. L.Priest, J. R. and Budo, Y.J. Appl. Phys. 34, 3261 (1963).
18Schwoebel, R.L.J. Appl. Phys. 37, 2515 (1966).
19d'Heurle, F., Berenbaum, L. and Rosenberg, R.Trans. AIME 242, 502 (1968).
20Townsend, P.H. and Plas, H.A. Vander, in Thin Films: The Relationship of Structure to Properties, edited by Aita, C. R. and Sree Harsha, K. S. (Mater. Res. Soc. Symp. Proc. 47, Pittsburgh, PA, 1985), p. 121.
21Gardner, D.S.Nichalka, T. L.Barbee, T.W.Saraswat, K.C.McVittie, J. P. and Meindl, J. D.Proc. 1st Int. VLSI Multilevel Interconnect Conf. 68 (1984).
22Liu, H. Y.Chang, P. H.Bohlman, J. and Tsai, H. L. in Adhesion in Solids, edited by Mattox, D. M.Baglin, J. E. E.Gottschall, R. J. and Batich, C.D. (Mater. Res. Soc. Symp. Proc. 119, Pittsburgh, PA, 1988), p. 153.
23Gardner, D. S. and Flinn, P. A.IEEE Trans. Electron Devices 35, 2160 (1988).

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The properties of thermal hillocks as a function of linewidth and process parameter in Al-on-chemical-vapor-deposited W films

  • Carey A. Pico (a1) and Tom D. Bonifield (a1)


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