METHOD OF SURFACE PROFILE CORRECTION USING GAS CLUSTER ION BEAM

A method for correcting a surface profile on a substrate is described. In particular, the method includes receiving a substrate having a heterogeneous layer composed of a first material and a second material, wherein the heterogeneous layer has an initial upper surface exposing the first material and the second material, and defining a first surface profile across the substrate. The method further includes setting a target surface profile for the heterogeneous layer, selectively removing at least a portion of the first material using a gas cluster ion beam (GCIB) etching process, and recessing the first material beneath the second material, and thereafter, selectively removing at least a portion of the second material to achieve a final upper surface exposing the first material and the second material, and defining a second surface profile, wherein the second surface profile is within a pre-determined tolerance of the target surface profile.