Polarization contact: Concept and initial assessment

Abstract

Simulations using the aerial image simulator SPLAT are performed to analyze various structures for printing contacts, motivated by trying to condense the double exposure of two lines into a single exposure. The polarization contact uses polarization bars in the arms of two crossed orthogonal lines as a means to generate a contact in a single exposure. Characterizations of the contact structures are possible by investigating their normalized unit contours. From cut lines of these contours, each structure can be understood based solely on its geometries. The scaling property of optical systems allows these unit spread functions to ultimately characterize its behavior. The structures are similar in their response to 1 Rayleigh unit of defocus, with each structure having an intensity ratio of peak defocus to perfect focus of about 0.79. Dense contacts are generated using a polarization-phase carpet that condenses a double exposure with phase shifting into a single exposure, at a cost of 75% less throughput.