The Small Etch Cell
One of the most common application of an electrochemical etching cell is a preparation of Nanocrystalline Porous Silicon Layer on a single crystal Si wafer. It well fits aqueous (EPDM O-Rings) and organic solvent (FFKM O-Rings) electrolyte requirements.
To perform an electrochemical process, a square conducting sample is placed on the cell base, using a piece of aluminum foil as a back contact. The setup is sealed by an O-ring to prevent the electrolyte leakage. The cell is filed with an electrolyte and the wire electrode is immersed in the solution as a counter electrode. An electric current is passed between the aluminum back contact and the wire electrode for a certain amount of time. After the process, the cell elements should be washed several times with ethanol and dried under the nitrogen flow. See the assembly demonstration here.
nominal exposure area: 0.21 cm2
electrolyte volume: 2.2 mL
minimum sample size: 12 mm x 12 mm
maximum sample width: 31 mm
This etch cell has been developed based on a design of Prof. Dr. Michael J. Sailor, published in Porous Silicon in Practice: Preparation, Characterization and Applications, Appendix A1. Etch Cell Engineering Diagrams and Schematics.