ASML Holding N.V.
Measurement systems, lithographic apparatus, device manufacturing method and a method of measuring

Abstract:

A measurement system for measuring a position and/or displacement of an object (40), the measurement system comprising a sensor (20) and a target (45), the sensor comprising an electromagnet (21); a driving circuit (24) configured to drive the electromagnet to generate an alternating magnetic field (AMF); a measuring circuit (25) configured to measure an electrical impedance parameter of the electromagnet; the target being located on a surface (41) of the object that faces the sensor, wherein the target comprises a graphene layer (46), and wherein, in use, when the alternating magnetic field interacts with the target, the alternating magnetic field changes (RMF), altering the electrical impedance parameter of the electromagnet.