Dry etching of silver for the metallization in microelectronics is investigated. Etching is performed using an electron-cyclotron-resonance reactive-ion-beam-etching system (ECR-RIBE) in an Ar/CF 4 or Ar/CF 4 /O 2 mixture. The etch characteristics are strongly affected by ion energy (beam voltage and microwave energy); the O 2 concentration in the reactive mixture has only a small effect. An anisotropic, smooth etch profile and clean surface are obtained. Focused ion beam (FIB) and atomic force microscopy (AFM) have been used to study the etched profile and the roughness, respectively.