SAN JOSE, Calif. Luminescent Technologies is reporting on the latest results of its inverse lithography technology as applied to 45- and 32-nanometer chips at the SPIE Advanced Lithography Conference, running here Feb. 25-March 2.
Among the findings is that ILT can address the problem of line-end shortening in the poly and diffusion layers at 45 nm, Luminescent said. Manufacturers are exploring the possibility of extending their dry steppers at the 45-nm node, delaying the move to immersion lithography.
With current optical proximity correction (OPC), printing critical layers such as poly and active has been extremely difficult because of the line-end shortening. The poly layer is especially complex since the line-end space is tight, leaving no room for OPC to correct the problem. According to Luminescent Technologies, ILT easily prints 45-nm poly and diffusion layers with an adequate process window.
Also, depth of focus (DOF) has been improved by at least 100 nm, which represents an improvement of more than 30 percent over conventional solutions. This improvement has important implications for mask manufacturability. Using conventional OPC, the best DOF tends to fall below 300 nm, which leaves a very small process margin.
The improved DOF generated by ILT expands the process margin, letting manufacturers proceed to production with confidence using reticles with currently available CD controls, according to Luminescent.