WAFER PLANARITY CONTROL BETWEEN PATTERN LEVELS

摘要

A method for controlling the flatness of a wafer between lithography pattern levels. A first lithography step is performed on a topside semiconductor surface of the wafer. Reference curvature information is obtained for the wafer. The reference curvature is other than planar. At least one process step is performed that results in a changed curvature relative to the reference curvature. The changed curvature information is obtained for the wafer. Stress on a bottomside surface of the wafer is modified that reduces a difference between the changed curvature and the reference curvature. A second lithography step is performed on the topside semiconductor surface while the modified stress distribution is present.