Characterization of low-order aberrations in the SEMATECH Albany MET tool

Previous papers have reported on print-based methods used to measure the aberrations in the SEMATECH Berkeley EUV microfield exposure tool (MET). The data showed that the tool has larger aberrations than those measured during interferometry (both visible and EUV) performed before the optic was integrated into the tool. The same analysis has been performed on the SEMATECH Albany MET to measure the low-order aberrations. As with the SEMATECH Berkeley tool, quantitative aberration measurements have revealed elevated levels of astigmatism and spherical error. Additionally, we find elevated levels of coma and field tilt and curvature.