The 100 mm × 100 mm Extreme Ultraviolet Graphite Pellicle: Nano‐Pellicle Production Using the Lowest Free Energy at the Graphite–Water Interface

Extreme ultraviolet (EUV) lithography is developed and implemented to fabricate nanodevices under 7 nm. Among the various challenges of EUV lithography, it is certainly a priority for a pellicle, as a physical shield, to protect a reflective EUV mask. Here, a practical, facile, industrial-friendly pellicle fabrication method is suggested to suspend a nanometer-thick graphite film (NGF) onto a pellicle frame (inner hole: 100 mm x 100 mm) by the vertical transfer (VT) method, benefitting from the lowest total free energy at the interfaces between NGF, water, and air. Based on the plate model of Neumann and Good, the free energy at the interfaces at various scooping angles is obtained; it is minimized at 90 degrees (VT). Finally, for the very first time an NGF pellicle (100 mm x 100 mm) and 80.6% transmission at 13.5 nm (EUV) using the VT method are demonstrated.