RUNAWAY GROWTH IN 2-DIMENSIONAL ELECTRODEPOSITION

We have investigated electrochemical deposition of copper along a very thin gold edge. Exploration of the transition between compact and bra nched morphologies reveals a faceted morphology, at very low current d ensities, which is composed of a pentagonal arrangement of twinned cry stals. For higher current densities, repeated nucleation gives a tip-s plitting regime. A transition between tip-splitting and side-branching morphology is obtained by inducing anisotropy on the substrate, in th e form of microscopic teflon furrows. The growth speed of the differen t morphologies is very different.