ELECTROSTATIC SENSING CHUCK USING AREA MATCHED ELECTRODES

摘要

Provided is an electrostatic sensing chuck for attracting particles to a portion of a particle contact surface near a deposition electrode, the electrostatic sensing chuck comprising a pixel comprising: a deposition electrode (DE) for selectively establishing an attraction field (Ea) at the particle contact surface; a shield electrode (SE) oppositely biased with respect to the deposition electrode; a charge sensing circuit to measure charge accumulated on each of the deposition electrode and the shield electrode, wherein the charge sensing circuit subtracts a second charge it senses at the shield electrode from a first charge it senses at the deposition electrode, thereby determining accumulated charge at the deposition electrode balanced by accumulated charge at the shield electrode.