Further insights on dynamic morphological transitions in quasi-two-dimensional electrodeposition

Abstract

Dynamic morphological transitions in thin-layer electrodeposits obtained from copper sulphate solutions have been studied. The chemical composition of the electrodeposits indicates that they appear as a consequence of the competition between copper and cuprous oxide formation. In addition, the Ohmic control of the process is verified at initial stages of the deposit growth. At higher deposit developments, gravity-induced convection currents play a role in the control of the whole process and affect the position of these transitions.

The formation of patterns of electrochemical deposits in an ultra-thin layer of CuSO4 solution

“…Under higher growth driving force, deposits were grown at a faster rate and the smaller grains were usually obtained [10,29]. Moreover, under different driving force, the distribution of local electric field intensity and the ion immigration at the growth front should be different, and the morphologies of deposits should vary accordingly [12, 13,17,29,31].…”

“…Afterwards, other researchers found that, besides the fractal morphology, the dense branching and dendritic patterns in the electrochemical deposition procedure of zinc could also be obtained under different experimental conditions [6,7]. Recently, it was distinctly understood that the patterns of electrochemical deposits were very sensitive to the materials studied and the experimental conditions [8][9][10][11][12][13][14][15]. Based on the analysis of the relationship between deposits patterns and experiment parameters, Trigueros and Sagues et al developed a rather complicated ''morphology phase diagrams'' [16,17].…”

Growth of electrolytic copper dendrites. III: Influence of the presence of copper sulphate

“…As the reduction of cuprous ions into copper metal is favoured in alkaline medium, this transition can be attributed to the movement of an acidic front towards the deposit [39]. This example of morphological transition was given on tantalum as it is an attractive metal for microelectronics but this behaviour is also found on copper.…”

“…For a copper sulfate solution, the authors have shown [34,38,39] that the formation of cuprous oxide (Cu 2 O) is often responsible for the transition. As the reduction of cuprous ions into copper metal is favoured in alkaline medium, this transition can be attributed to the movement of an acidic front towards the deposit [39].…”

Pattern transition in Cu–Zn binary electrochemical deposition

“…Many authors have reported the quasi-two-dimensional growth of metallic electrodeposits, particularly for copper [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and zinc [16][17][18][19][20][21][22][23][24][25], and other metals [26][27][28][29][30][31]. The typical patterns observed so far are stringy, dendritic, open ramified, dense branching morphology (DBM), and diffusion limited aggregation (DLA), etc, depending on the growing conditions, such as applied voltage, concentration of the solution and thickness of the electrolyte layer.…”