Journal of the Electrochemical Society, Vol.145, No.9, 3070-3074, 1998
Pulse reverse copper electrodeposition in high aspect ratio trenches and vias
A theoretical model, based on a one-dimensional approximation, for the filling of high-aspect ratio trenches and vias with copper by pulse reverse electrodeposition is presented. The dependence of void size on the pulse waveform is demonstrated for submicron features. It is shown that the off-time should be on the order of the diffusion-time constant and that the deposition time should be smaller than the diffusion time constant. Reverse current, i.e., dissolution, is shown to play an important role in diminishing void size. Comparison with two-dimensional calculations indicates that the theory is an adequate yet efficient means of simulating shape change.