Silicon Etching in HNO3/HF Solution: Charge Balance for the Oxidation Reaction

The potential dependence of the current and the etch rate of p- and n-type silicon electrodes in 6 M HNO3–6 M HF solution was investigated. Hydrogen evolved during etching at the open-circuit potential was also measured. These results give insight into the different processes occurring during etching. A detailed charge balance for silicon oxidation in the etchant is deduced