Multi-stack extreme-ultraviolet pellicle with out-of-band reduction

Abstract

The out-of-band (OoB) radiation that can cause serious aerial image deformation on the wafer is reported. In order to check the maximum allowable OoB radiation reflectivity at the extreme ultra-violet (EUV) pellicle, we simulated the effect of OoB radiation and found that the maximum allowable OoB radiation reflectivity at the pellicle should be smaller than 15 % which satisfy our criteria such as aerial image critical dimension (CD), contrast, and normalized image log slope (NILS). We suggested a new multi-stack EUV pellicle that can have high EUV transmission, minimal OoB radiation reflectivity, and enough deep ultra-violet transmission for inspection and alignment of the mask through the EUV pellicle. © 2015 SPIE.