The XeF2 etcher in the UCLA NanoLab uses XeF2 crystals and a vacuum chamber to produce fluorine vapors, which isotropically etch silicon with very high selectivities to photoresist, oxides, nitrides, and many metals. Typical silicon etch rates are 1-2 um per minute. Samples up to 4 inches in diameter can be accommodated and the etch process may be observed through the transparent chamber lid. Typical applications are for cantilever release etching for micro-machined structures.