A New Preferential Etch for Defects in Silicon Crystals

A new preferential etch for (100) and (111) oriented, p- and n-type silicon has been developed. This article describes the basic chemistry of the etching process and provides examples of how it defines critical features such as oxidation-induced stacking faults, dislocations, swirl, and striations with minimum surface roughness and pitting. A relatively slow etch rate of around 1 μm/min at room temperature provides etch good control and a long shelf life allows the solution to be stored in large quantities.