Pattern Formation during Anodic Etching of Semiconductors

Abstract

Anodically dissolving semiconductor electrodes show a wealth of pattern formation phenomena in time and space. This paper reviews these phenomena and attempts a general explanation in terms of the so-called current burst model. The current burst model asserts that current flow through anodically dissolving semiconductor electrodes is localized in space and time. The only relevant parameters of the model are probability functions for current "on" and "off". It will be shown that interactions between current bursts in space and time account quantitatively, or at least qualitatively, for a wealth of the pattern formation phenomena observed on semiconductor electrodes that can be classified as oscillations in time and space (= pore formation).

Characterization of electrical discharges during spark anodization of zirconium in different electrolytes

“…In regions 8 and 10, the number of discharges decreased and the discharges concentrated at some spots on the electrode surface. According to some authors [21,48], the local oxide film is a decisive parameter for the current flow since the discharges are generated through weak sites in anodic oxide film. For this reason, this process occurs stochastically in the early stages of breakdown; however, the enlargement of the oxide thickness decreases the number of these sites, reducing the discharge population density.…”

Hydrogen Embrittlement as a Conspicuous Material Challenge─Comprehensive Review and Future Directions

“…Note that a large number of kinks pairs will form along the dislocation line upon thermal activation, and the movement of a screw dislocation is a result of the collective behavior of the kink pairs. Reproduced with permission based on web course material published by Föll, Kiel University.…”