Optimization of displacement Talbot lithography for fabrication of uniform high aspect ratio gratings
Zhitian Shi, Konstantins Jefimovs, Lucia Romano, Marco Stampanoni
Abstract
Abstract Displacement Talbot lithography can rapidly pattern periodic nanostructures with high depth of focus over large area. Imperfections in the phase mask profile and the stage movement inaccuracies during the exposure cause linewidth variation in every second line of binary gratings. While this beating is barely visible in patterned photoresist, it leads to substantial depth variation when transferred into high aspect ratio silicon structures, because of micro-loading in deep reactive ion etching. A proper scan range compensated the defect, and a beating-free grating with pitch size of 1 μ m and aspect ratio of 54:1 is demonstrated.
Topics & Concepts
LithographyMaterials sciencePhotoresistGratingLaser linewidthOpticsAspect ratio (aeronautics)PhotolithographyFabricationReactive-ion etchingX-ray lithographyNext-generation lithographyResistDiffraction gratingEtching (microfabrication)Deep reactive-ion etchingOptoelectronicsElectron-beam lithographyNanotechnologyLaserPhysicsLayer (electronics)Alternative medicineMedicinePathologyOptical Coatings and GratingsAdvancements in Photolithography TechniquesNanofabrication and Lithography Techniques