Particle defects placed on extreme-ultraviolet (EUV) pellicle can degrade pattern quality due to the particle defect shadowing. It is obvious that serious patterning error would be occurred due to larger particle defects on top of the pellicle, so that the effect of critical dimension (CD) degradation caused by particle defect on top of the EUV pellicle is investigated. We tried to determine the maximum allowable particle defect size with various pattern types and nodes via commercial simulation tool. Also, we set the boundaries for CD error limit of 5 % and CD non-uniformity to 0.2 nm. Based on these result, we determined the maximum allowable particle defect size for N5 and N7 nodes in order to find the proper defect control.
There has been reports of EUV scanner aberration effects to the patterns down to 18 nm half-pitch (hp). Maximum aberration of the latest EUV scanner is reported as 25 mλ. We believe that the first EUV mass production will be applied to the devices of 16 nm hp, so that we checked the aberration effects on 16 nm periodic line and space patterns and nonperiodic double and five-bar patterns. Coma aberrations of Z7, Z8, Z14 and Z15 Zernike polynomials (ZP) seems to be the dominant ones that make pattern distortion. Non-negligible critical dimension (CD) variation and position shift are obtained with the reported maximum 25 mλ of coma aberration. Optical proximity correction (OPC) is tried to see if this aberration effects can be minimized, so that we can make the desired patterns even though there is a non-correctable scanner aberration.