Corrosion protection for micromechanical metallic layers

摘要

On a sacrificial layer (1) of silicon dioxide, or similar, the under-protection layer (2) of TiN is built using chemical vapour deposition. Over this the metal layer (3) and the over-protection layer (4) of TiN are deposited. A further protection layer (5) is deposited above this. The protection layer (5) is then etched away leaving a TiN layer (6) protecting the side walls of the metal film (3). The desired micro-mechanical cavity (9) is then etched in the sacrificial layer (1) with hydrofluoric acid. The layer of TiN (7), which is resistant to hydrofluoric acid, surrounds the metal film and protects it from corrosion during this process.