Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-06T12:15:40.288Z Has data issue: false hasContentIssue false

Residual Stress, Adhesion and Crystallization of Ion-Sputtered and Ibed Processed NiTi Films

Published online by Cambridge University Press:  25 February 2011

B. Walles
Affiliation:
Department of Metallurgy, Mechanics and Materials Science, Michigan State University, East Lansing, MI 48824
L. Chang
Affiliation:
Department of Metallurgy, Mechanics and Materials Science, Michigan State University, East Lansing, MI 48824
D. S. Grummon
Affiliation:
Department of Metallurgy, Mechanics and Materials Science, Michigan State University, East Lansing, MI 48824
Get access

Abstract

When conventional sputtering is used to deposit nickel-titanium thin films at temperatures below ∼623 - 723 Kelvins, the resultant structures are amorphous and the films must be annealed to form the requisite B2 parent ordering. This invites complications related to interface diffusion and chemical reaction with components of the substrate. For the present work, thin films of near-equiatomic NiTi were prepared on potassium chloride, (100) single-crystal silicon, and Si3N4 passivated silicon substrates by ion sputtering and by ion beam enhanced deposition (IBED). We have investigated residual stress levels produced by these processes, evaluated substrate adhesion levels, and explored the crystallization behavior of NiTi films grown under conditions of concurrent low-energy inert gas ion bombardment. Residual stresses of ionsputtered and IBED films were measured using profilometric techniques. Film crystallization behavior was studied by transmission electron microscopy of as-deposited films. Films produced by unassisted ion sputtering showed compressive residual stresses in the as-deposited amorphous state, which became highly tensile after annealing, leading to spontaneous cracking and delamination. Preliminary results from IBED experiments showed a reduction in the asdeposited stress, and improved adhesion. Under certain conditions, ion enhancement of the deposition process promoted film crystallization during deposition at moderate substrate temperature, producing a dispersion of extremely fine particles, indexed as Ni3Ti.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Walker, J. A. and Gabriel, J., Proc. 5th Tnt. Conf. on Solid State Sensors and Actuators Cext. absir. B8), June 1989. Monireaux, Switzerland, p123 (1989).Google Scholar
2. Thornton, J. A., and Hoffman, D. W., Thin Solid Films, 171, pp. 531 (1989).Google Scholar
3. d'Heurle, F. M., and Harper, J. M. E., Thin Solid Films 171, pp. 8192 (1989).Google Scholar
4. Hoffman, D. W. and Thomnton, J. A., Thin Sol. Filma 45, p387 (1977).Google Scholar
5. Woif, G.K., and Ensinger, W., IBMM 90: 7th Tnt. Conf. on Ton Ileam Mod, of Matls, p. 97 (Sept. 1990).Google Scholar
6. Lee, G. H., Cailler, M., and Kwon, S. C., Thin Solid Films, 185, pp. 3555 (1990).Google Scholar
7. Smidt, F. A., Int. Met. Rev. 35, pp. 61128 (1990).Google Scholar
8. Stoney, G.G., Proc. Royal Soc. A82, p. 172 (1909).Google Scholar
9. Buehler, W. J. and Wiley, R. C., U.S. Nay. Ord. Lab. Tech. Rep. AD-266607, 61-75 (1961).Google Scholar
10. Kelber, J. A., in Adhesion in Solids, MRS Symposium Proceedings 119, p. 255 (1988).Google Scholar
11. Busch, A. D.. private communication (1991).Google Scholar
12. Busehow, K. H. J., J. Phys. F: Met. Phys. 13, pp. 563571 (1983).CrossRefGoogle Scholar
13JCPDS file 5-723.Google Scholar