Dislocation Etch for (100) Planes in Silicon

A new etch composed of a dilute aqueous solution of an alkali dichromate and hydrofluoric acid, for suitably revealing dislocations and other lattice defects in (100) planes of silicon, is reported. The etch is fast (typically 5 min), brings out both lineage (low angle grain boundaries) and slip lines, and works over a wide range of resistivities for n‐ and p‐type material. The application of the etch is not restricted to (100) planes; dislocation etch pits are formed on all crystallographic orientations. The same etching characteristics were found with dilute aqueous solutions prepared from various chromium compounds and hydrofluoric acid.