Reducing wire erosion during damascene processing

摘要

A damascene process incorporating a GCIB step is provided. The GCIB step can replace one or more CMP steps in the traditional damascene process. The GCIB step allows for selectable removal of unwanted material and thus, reduces unwanted erosion of certain nearby structures during damascene process. A GCIB step may also be incorporated in the damascene process as a final polish step to clean up surfaces that have been planarized using a CMP step.

主权项

1. A method of reducing erosion in a damascene process, comprising the steps of:
arranging a first layer in a trench in a dielectric formed on a substrate and directly on a surface of the dielectric adjacent to the trench; depositing a bulk conductor on the first layer in the trench and adjacent to the trench; and selectively removing an upper portion of the bulk conductor with a gas cluster ion beam (GCIB) process that is selective to the bulk conductor by impacting large clusters of preselected types of atoms on the upper portion of the bulk conductor to be removed, wherein the GCIB process exposes a surface portion of the first layer that is arranged directly on the surface of the dielectric adjacent to the trench such that an upper surface of the surface portion is coplanar with an upper surface of the bulk conductor in the trench.