Challenges in EUV mask blank deposition for high volume manufacturing

Abstract EUVL requires high-yield, low defect density reflective mask blanks, a requirement which is considered one of the top two cr itical technology gaps for commerc ialization of the technology. At the SEMATECH Mask Blank Development Center (M BDC), research on defect reduction and yield improvement for EUV mask blanks is being purs ued using the Veeco Nexus deposition tool. The defect performance of this tool is one of the factors limiting the availability of defect-free EUVL mask blanks. SEMATECH identified the key compone nts in the ion beam deposition system that are currently impeding the reduction of defect density and the yield of EUV mask blanks. SEMATECH improved the defect performance of the champion blank with 12 defects above 45 nm which is a 36% improvement from the data reported last year for the champion blank (19 defects above 45 nm). The yield analysis on high quality mask blanks from ion beam depos ition system is also presented. Substrate quality is currently the bi ggest source of mask blank defect s, while high yield also requires complete elimination of large size defects from deposition. A roadmap to meet the required defectivity specification for EUV mask blanks is presented.