Spatially Coupled Bipolar Electrodeposition in Thin-Layer Cells under Periodic Voltage Control

V. D'ANGELO; G. MARSHALL; J.-C. BRADLEY; G. GONZALEZ; S. BABU; F.V. MOLINA; C. IEMMI,

Morphological Evolution of Electrodeposits -and- Electrochemical Processing in ULSI Fabrication and Electrodeposition of and on Semiconductors IV

The Electrochemical Society

Lugar: Washington DC; Año: 2004; p. 190 - 199

We study the ion transport in the interdisc region of thin‑layer cells under square wave electric potential pulses by means of optical and particle velocimetry techniques. Experiments and measurements reveal that ion transport and deposit morphology, that constitute crucial factors in the characteristics of the connection, are substantially influenced by pulse frequency. Measurements show that the incubation time is roughly twice of that observed under DC conditions and does not increase with frequency. During this period, migration and diffusion are the dominant transport modes. After branching develops, convection plays a relevant role as well. It is found that  the deposit growth speed does not depends significantly on  pulse frequency. A remarkable effect is found at low frequencies: the ion transport and the deposit growth pulsate in phase with the electric potential. At the scale of the observation (10x), no signs of inertial effects were discerned.