The Large Etch Cell
One of the most common applications of an electrochemical etching cell is the preparation of a Nanocrystalline Porous Silicon Layer on a single crystal Si wafer.
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 electrolyte leakage. The cell is filled 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: 8.6 cm2
electrolyte volume: 15 mL
minimum sample size: 38 mm x 38 mm
maximum sample width: 45 mm
Spiral Metal Wire Electrode for Etch Cell
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.