No abstract

EUVL, i.e. projection lithography, utilizing actmic wavelengths in the range of 21 1-13 nm, appears to be the natural extension of optical lithography into the NGL-regime. All-reflective imaging systems, utilizing aspherical, multilayer coated, near normal incidence mirrors with reflectivities around 70%, were designed to enable diffraction limited imaging from 7Onm down to 3Onm feature sizes at high throughput. However, diffraction limited performance of optical systems calls for surface figures of typically 2J50to 2/1OO. Considering the operation wavelength of 2l 1-13 nm, this demand corresponds to unprecedented requirements for figure metrology and fabrication technology. Simultaneously, low flare levels and high reflectivities of the mirrors have to be ensured for proper system operation. These properties are related to the substrate roughness in the mid spatial (typically ljim-lmm) and high spatial (typically <1 jim) frequency ranges respectively. Accordingly these quantities have to be generated and controlled on a few-A-level.In this paper, the metrology and fabrication concepts at CARL ZEISS will be reviewed. The present status in the fabrication of specific EUVL mirrors will be reported as well.

No abstract

Application of mirror manufacturing and its appropriate metrology at Carl Zeiss Laser Optics shall be illustrated by recent examples. Specifications and achieved results of finalized mirrors with different geometries and sets of specifications are discussed.