Directional and ionized physical vapor deposition for microelectronics applications

The manufacturing of interconnect features on semiconductor wafers has evolved from Lift-off-based evaporation to reactive ion etching metallization and now to Damascene technology. Physical sputter deposition has been widely used for blanket metal film deposition, but is impractical for high aspect topographies. Filtered, or directional sputter techniques, such as long throw or collimation, have been used for some high aspect ratio applications, but suffer from poor efficiency, high cost, and/or poor scaling. Ionized sputter deposition, which uses in-flight ionization of sputtered metal atoms and subsequent film deposition by means of a substrate potential, has been developed as a technique to extend physical vapor deposition into higher aspect ratios. (C) 1998 American Vacuum Society.