Measurement apparatus and a method for determining a substrate grid

A computer program product comprising a non-transitory computer-readable medium having instructions, the instructions, upon execution by a computer system, configured to cause the computer system to at least:

• obtain position data, measured outside of a lithographic apparatus configured to fabricate one or more features on a substrate, for a plurality of first features and/or a plurality of second features on the substrate;
• obtain asymmetry data for at least a feature of the plurality of first features and/or the plurality of second features;
• determine a substrate grid based on at least the position data, the determined substrate grid describing deformation across the substrate prior to exposure of the substrate in the lithographic apparatus;
• and
• pass the substrate grid and asymmetry data toward the lithographic apparatus for controlling at least part of an exposure process to fabricate one or more features on the substrate.