Physics (Internal)

Influence of non-equilibrium conditions on thin film stress and surface morphology evolution

This event is part of the Biophysics/Condensed Matter Seminar Series.

Pizza served at 11:30 AM

Abstract: During thin film or surface processing, the surface of the film is not in equilibrium. The impinging flux of adatoms or ions alters the chemical potential on the surface, which can lead to a variety of non-equilibrium effects. In this talk, we will discuss results of several different studies in which the dynamic conditions on the surface modify its evolution: 1) stress generation in polycrystalline films and 2) pattern formation during low energy ion sputtering. In the case of polycrystalline film stress, we will discuss how the surface supersaturation during deposition raises the chemical potential of the surface, driving atoms into the grain boundary and generating compressive stress. In the case of sputter ripple formation, we will discuss how the presence of ion-induced defects changes the surface transport and modifies the ripple wavelength with temperature and flux. In each case, we will describe how the studies are aided by the use of real-time in situ diagnostics that enable the kinetic evolution of the parameters to be studied.