Collimated metal deposition.

摘要

A process and structure for depositing metal lines in a lift-off process is disclosed. The process provides the deposition of a four-layer structure or lift-off stencil, comprising a first layer (12) of a lift-off polymer etchable in oxygen plasma, a first barrier layer (14) of hexamethyldisilizane (HMDS) resistant to an oxygen plasma, a second lift-off layer (16) and a second barrier layer (18). Once these layers are deposited, a layer (20) of photoresist is deposited and lithographically defined with the metal conductor pattern desired. The layers are them sequentially etched with oxygen and CF4, resulting in a dual overhang lift-off structure. Metal (26, 24) is then deposited by evaporation or sputtering through the lift-off structure. Following metal deposition, the lift-off structure is dissolved or lifted-off in a solvent such as N-methylpyrrolidone (NMP).