Patent ID: 8303833

Claim:
A method for etching a substrate to form microscopic structures, comprising: forming a protective mask on one or more portions of a surface of the substrate using a focused beam process, the focused beam either depositing a masking material near the impact point of the beam by decomposing a precursor gas or the focused beam patterning an existing layer of masking material by etching the masking material near the impact point of the beam; forming a structure in the substrate by directing a beam of ionized particles from a plasma source through an ion optical column toward the sample to selectively etch unmasked portions of the substrate, the ionized particles having sufficient energy upon contacting the substrate to chemically etch the unmasked portions, but insufficient energy to substantially sputter the unmasked portions; removing the masking material by directing a second beam of ionized particles to selectively etch the masking material without substantially etching the substrate material, the ionized particles having sufficient energy upon contacting the surface to chemically etch the masked portions, but insufficient energy to sputter the masked portions.