System and method for generating level data for a surface of a substrate

An apparatus, comprising:

• a level sensing controller configured to:
• receive first level data for a first region of a substrate;
• generate measurement control map data based on the first level data;
• and
• generate a servo control signal based on the measurement control map data;
• and
• a second level sensing device configured to generate, based on the measurement control map data, second level data for a second region of the substrate,
• wherein the first region comprises:
• a first subregion having a first surface level;
• and
• a second subregion having a second surface level,
• wherein the second region comprises a plurality of third subregions each having a third surface level equal to about the first surface level;
• and
• wherein the second level sensing device, based on the servo control signal, is further configured to generate a topography of the substrate at about the third surface level and to keep the third surface level within a measurement range during a measurement process.

A method, comprising:

• receiving, by a level sensing controller, first level data for a first region of a substrate, wherein the first region comprises:
• a first subregion having a first surface level;
• and
• a second subregion having a second surface level;
• generating, by the level sensing controller and based on the first level data, measurement control map data;
• generating, by a second level sensing device and based on the measurement control map data, second level data for a second region of the substrate, wherein the second region comprises:
• a plurality of third subregions each having a third surface level equal to about the first surface level;
• generating, by the level sensing controller, a servo control signal based on the measurement control map data;
• following, by the second level sensing device and based on the servo control signal, a topography of the substrate at about the third surface level;
• and
• keeping, by the second level sensing device and based on the servo control signal, the third surface level within a measurement range during a measurement process.