Method for cleaning metal precipitates in semiconductor processes

摘要

A new method of cleaning metal precipitates after the etching of metal lines using a two-step process is described. Semiconductor device structures are provided in and on a semiconductor substrate. The semiconductor device structures are covered with an insulating layer. A barrier metal layer is deposited overlying the insulating layer. A metal layer is deposited overlying the barrier metal layer wherein metal precipitates form at the interface between the barrier metal layer and the metal layer. The metal layer is covered with a layer of photoresist which is exposed to actinic light and developed and patterned to form the desired photoresist mask. The metal layer is etched away where it is not covered by the photoresist mask to form metal lines whereby the metal precipitates are exposed on the surface of the barrier metal layer. The barrier metal layer is anisotropically etched into using a high DC bias of greater than 240 volts and thereafter isotropically etched into underlying the metal precipitates whereby the metal precipitates are stripped away from the surface of the barrier metal layer completing the cleaning of the metal precipitates in the formation of metal lines in the fabrication of an integrated circuit.