Continuum model for nanocolumn growth during oblique angle deposition

A continuum equation for the shadowing growth of individual nanostructures by oblique angle deposition is proposed and numerically integrated. The radius R of rotationally symmetric columns is calculated as a function of height z. Before the radius R saturates at its final value R-sat, column shapes obey the power law Rsimilar toz(p) with the exponent value psimilar to0.37+/-0.02. The results are compared to those of an experimental study of Si columns grown on a template (psimilar to0.39+/-0.03), and on a flat surface (psimilar to0.32+/-0.01). The model additionally predicts that the saturated radius should depend on column separation d as R(sat)similar tod(1.20+/-.01). This relation implies that the gap between the surfaces of adjacent columns can be optimized by altering the column separation. (C) 2004 American Institute of Physics.