APPLICATION OF X-RAY MASK FABRICATION TECHNOLOGIES TO HIGH-RESOLUTION, LARGE-DIAMETER TA FRESNEL ZONE PLATES

High-resolution and large diameter condenser Fresnel zone plates were fabricated in a 0.35-mu m-thick Ta layer on an SiN membrane. A newly d eveloped conversion algorithm was applied where sub-field length and p osition are randamized in order to suppress the evolution of small fig ures at pattern divided parts such as subfield boundaries in the conve ntional conversion algorithm. A single layer resist system was adopted to write large diameter, ultra-fine, dense ring patterns. FZPs with t he outer-most linewidth of 50 nm was successfully fabricated by applyi ng the subtractive x-ray mask fabrication process.