Process to reduce the surface roughness of e.g. cordierite, Zero-expansion Pore-free Ceramics or silicon carbide lens holder used in micro-lithographic projection process

摘要

In a process to reduce the surface roughness of a sintered ceramic material, the pores are first sealed followed by surface polishing to reduce the roughness to less than 2 nm preferably less than 1 nm. Further claimed is a commensurate component of sintered ceramic material, a wafer holder and an optical element for a projector.