On the self-patterning of islands by mechanical constraints during electrochemical deposition

We present a theoretical interpretation for a self-assembly pattern of Cu islands deposited on amorphous NiTi surface by electrochemical deposition. The self-assembly pattern is composed of alternating island-rich and island-depleted zones. We propose that the self-assembly pattern is possibly due to the long-range island–island repulsion mediated by the substrate and the weak corrugation of delaminated NiTi substrate caused by the compressive stress associated with Cu island growth. Based on these two mechanisms, we performed numerical simulations to model the island growth and semiquantitatively reproduced the self-assembly pattern. The good agreement between the simulated patterns and those observed in experiments suggests that the combination of geometrical constraint and electrochemical deposition provides a promising way to fabricate self-assembly patterns for micro- and nanofabrications at low cost.