| Popis: |
In this work, 3D mask modeling capabilities of Calibre will be used to assess mask topography impact on EUV imaging. The EUV mask absorber height and the non-telecentric illumination at mask level, modulate the captured intensity from the shadowed mask area through the reflective optics on to the wafer, named as the mask shadowing effect. On the other hand, thinning the mask absorber height results in unwanted background intensity, or called flare. A true compromise has to be taken into account for the height parameter of a EUV mask absorber. We will discuss the state-of-the-art 3D mask modeling capabilities, and will present methodologies to tackle the described EUV mask shadowing effect in Calibre software. The findings will be validated against experiments on ASML's NXE:3100 EUV scanner at imec. Masks with two different absorber heights will be evaluated on various combinations of features containing line/space and contact-hole. |
