Development of a new mask pattern inspection tool NPI-7000 and applied results to EUV mask inspection

Abstract

Photo lithography potential expands for 32nm node to 2xnm device production by the development of immersion technology and the introduction of phase shift mask, and NPI-6000 using 199nm laser source was developed to correspond to 2xnm node photo mask pattern inspection. On the other hand, EUV lithography with 13.5nm exposure wavelength is dominant candidate for the next generation lithography because of its excellent resolution for 1x half pitch (hp) node device. But, applying 199nm optics to complicated lithography exposure tool option for hp2x nm node and beyond, further development such as image contrast enhancement will be needed. Therefore, a new mask inspection tool, NPI-7000, has been developed. This tool can implement not only photo mask pattern (hp1x) inspection, but also EUV mask pattern inspection (hp2x) and blanks inspection with high throughput. In this paper, features of NPI-7000 and new developed technologies were described and applied results to EUV mask inspections were introduced.