APPARATUS AND METHOD FOR ALIGNING SURFACES

摘要

Method, apparatus and stamp for aligning a first surface (11) of a first object (10) with a second surface (22) of a second object (20), facing said first surface, wherein light of a predetermined wavelength is introduced into one (10) of said objects and caused to propagate by internal reflection therein. The first and second surfaces carry correlating structures (13,25) which, when arranged at close distance from each other, couple light from said one object to the other of said objects by near-field tunnelling, to a degree dependent on the overlap of said structures. A light detector (26) is devised to detect a signal which is dependent on the amount of light coupled between said objects, for producing an alignment control signal. The invention is suitable for use in nanoimprint lithography.