Methods for etching a workpiece, an apparatus configured to etch a workpiece, and a non-transitory computer readable medium

An apparatus for etching a workpiece, the apparatus comprising:

• a thickness determining circuit for determining a thickness profile of the workpiece, the thickness profile based on the thicknesses of the workpiece continuously across the workpiece, the workpiece having a total thickness variation;
• an etchant dispenser for dispensing an etchant over the workpiece via the etchant dispenser;
• a positioning device for positioning the etchant dispenser at a plurality of positions over the workpiece;
• an etch profile determining circuit for determining a reference etch profile for each position of the plurality of positions, the reference etch profile for a respective position being a continuous etch profile that is obtained when material is etched from a reference workpiece in case the etchant dispenser is positioned at the respective position over the reference workpiece and an etchant is dispensed over the reference workpiece via the etchant dispenser;
• and
• an etch duration determining circuit for determining an etch duration for each position of the plurality of positions based on the determined thickness profile of the workpiece and the determined reference etch profile for each position of the plurality of positions, the determined etch duration for a respective position being a duration of time the etchant is dispensed over the workpiece via the etchant dispenser positioned at the respective position, wherein the total thickness variation of the workpiece is reduced when dispensing the etchant over the workpiece via the etchant dispenser for the respective etch duration for the respective position.