A method of dry plasma etching a semiconductor structure (20), having at least one semiconductor material layer (21), on a semiconductor wafer (200), involving a dry plasma reaction gas mixture (30.sub.i) being chemically selected for, and having an etch rate corresponding to, each semiconductor material layer (21); dividing the semiconductor structure (20) into a masked portion (23a) and an unmasked portion (23b); and sequentially exposing the unmasked portion (23b) of the semiconductor structure (20) to the dry plasma reaction gas mixture (30.sub.i).