i

Title of the course

MM 669: Mechanical Behavior of Thin Films

?

ii

Credit structure

L????????? T????????? P????????? C

3 ? ? ? ? ? 0 ? ? ? ? ?0? ? ? ? ? ?6

?

iii

Pre-requisite, if any

None

?

iv

Course content

Elasticity basics: Stress and strain tensors, tensor transformations, Mohr??????s circle representation of stress and strain, constitutive equations. Origin of stresses in thin films: thermoelastic mismatch between film and substrate, lattice mismatch in heteroepitaxial films, recrystallization, phase transformation, incorporation of atoms and chemical reactions. Application of the above for designing structures with low stresses. Experimental techniques for measuring stresses/strains in thin films: Substrate curvature; Stoney??????s equation, methods for curvature measurement, X-ray diffraction, nanoindentation, bulge test, 4-point bend test, and microtensile test. Models for high stresses, strain-hardening rates and Bauschinger effect in thin films, influence of grain size, film thickness and interfaces.

v

Texts/References

1. Thin film materials: stress, defect formation and surface evolution. L. B. Freund, S. Suresh, Cambridge University Press, 20032. Materials Science of Thin Films. M. Ohring, Academic Press, 1992.3. Mechanical Metallurgy. G. E. Dieter, McGraw-Hill, 1986.

vi

Instructor(s) name

Prof. Prita Pant