Below the 65-nm node, mask-making reticles have features which are smaller than the wavelength of the light used to expose the masks. These features can cause significant scattering and polarization of the exposure light, and must be accounted for to achieve accurate, high-numerical aperture lithography.
To address this requirement, Brion's Tachyon M3D (Mask 3D) product enables more accurate optical-proximity correction (OPC) and OPC verification by accounting for these mask 3D imaging effects.
Tachyon M3D constructs image-based photomask imaging models using electromagnetic-field simulation of the light passing through the 3D mask feature topography on the advanced 4X reticles used in leading-edge IC designs. The tool replaces the thin-mask approximation with its image-based mask 3D models, and then computes and combines wafer-image intensities from different source polarizations, before resist and etch computations.
The tool's capabilities are particularly critical when applied to through-focus lithography modeling. Significant mask 3D effects can occur across the full range of focus variation during the manufacturing process. With focus variation being an inevitability, and with its effects becoming more severe as lithography process windows continue to shrink, OPC and verification of OPC results become more critical.
Tachyon M3D is available now; contact Brion directly for pricing information.