D2S has unveiled first-of-a-kind mask-wafer double simulation accelerated workstation called TrueMask DS for hot-spot analysis, bit-cell design, research and development exploration and mask-defect classification that understands dose modulation and overlapping eBeam shots.
TrueMask DS is a critical instrument required for wafer fabs and mask shops for the qualification and optimization of ≤ 20 nm node designs, where assist features on photomasks below 80 nm can no longer be manufactured reliably and have an increasing effect on yield of wafers.
TrueMask DS has 0.1-nm-resolution mask simulation with mask dimensions up to 300 x 300 µm, including dose modulation and overlapping shots. It features sophisticated eBeam modeling along with arbitrary point spread functionalities for exploration. 5 x 5 µm interactive mask-wafer double simulation, quick, interactive aerial litho simulation of hardware acceleration and SEM interface to perform overlay analysis of images with simulations.
Optical proximity correction has been employed to incorporate SRAFs on photomasks to balance the optical impacts of sub-wavelength lithography that avoid minute features from printing properly. The SRAF shapes and other major features need to be designed with high-complexity in order to create the preferred images with adequate process windows over the wafer at the 20 nm node and beyond.
By implementing hardware acceleration, TrueMask DS can create a double simulation of the wafer and mask dimensions for 5 x 5 µm at interactive speeds. Users can try various variable-shaped beam shots for mask writing as well as dose modulation and overlapping shot techniques for the improvement of CD uniformity and reduction of mask write times, respectively.
The Chief Executive Officer at D2S, Aki Fujimura stated that lithography simulation is not sufficient to assess mask designs of innovative devices. Deploying mask-wafer double simulation is essential to know about the production process of mask shapes on both the wafer plane and the mask, he said. TrueMask DS is an important instrument through several design phases to production for test-chip engineers, memory-cell designers, OPC engineers, product engineers and mask engineers, he added.
Source: http://www.design2silicon.com