PELLICLE FILM OPTIMIZED FOR IMMERSION LITHOGRAPHY SYSTEMS WITH NA>1

摘要

An optical pellicle to protect a photomask from particulate contamination during semiconductor lithography is provided which has enhanced transparency and operational characteristics. The pellicle utilizes alternating layers of a transparent polymer and a transparent inorganic layer to form pellicles which have high transmission properties and high strength. In a preferred pellicle, a three-layer pellicle is provided having a transparent inorganic layer sandwiched between two polymer layers. A five-layer pellicle is also provided with the outer layers and a middle layer being polymer layers and the inner layers an inorganic material. The preferred polymer layer is a perfluorinated polymer such as Teflon(R) and the preferred inorganic material is silicon dioxide. The pellicle of the invention provides light transmission of greater than 0.99% at incident light angles up to arcsine 0.45.