Combines the DC or RF sputtering and the RF etching operations. While DC or RF power is applied to the target, a small amount of RF is also applied to the substrate table. As a result, the substrate and target are both bombarded by ions ( the substrate to a lesser extent than the target ). In many applications this process yields superior quality films than can be attained using DC or RF sputtering with grounded substrates. Bias sputtering influences the crystal structure, and tends to re-sputter trapped argon from the growing film during deposition and rearrange individual atoms of the sputtered material; this improves stoichiometry and step coverage. Bias sputtering can be used to adjust film resistivity and film stress to desired levels.
