X-ray mask pellicle

Abstract

An X-ray mask pellicle is capable of protecting the X-ray mask from contaminants and the wafer from contact with the X-ray absorber material of the mask. The X-ray mask pellicle is sufficiently thin to allow X-ray exposure at the required mask to wafer gaps yet is sufficiently durable, replaceable, tough and X-ray resistant to be used in X-ray lithography. A thin (organic or inorganic) X-ray mask pellicle to be placed covering the X-ray mask pattern area is fabricated as a thin film and attached to a support ring. A selected area of the pellicle film, tailored to cover the absorber pattern in the X-ray mask, is etched to decrease its thickness to below 2 .mu.m. If the thin film of the pellicle is not itself conductive, a thin conductive film may be coated on both sides. In an alternative embodiment, the separation between the pellicle and the X-ray mask can be achieved by forming the mask with a stepped profile.