By Jeff Dorsch, contributing editor
Nikon and KLA-Tencor put on separate conferences in San Jose, Calif., on Sunday, February 22, tackling issues in advanced optical lithography. The overarching theme in both sessions was the increased complexity of lithography as it approaches the 10-nanometer and 7nm process nodes.
“Complexity is much higher,” said Kevin Lucas of Synopsys at the Nikon event, LithoVision 2015. He noted that at the 28nm process node, lithographers could resort to five different options. For 14nm or 16nm, that expanded to eight options. There are 21 options available at 10nm, Lucas said, and at 7nm that explodes to more than 71 options.
“The increase in complexity is pretty dramatic,” he observed.
Electronic design automation vendors have “to provide more accurate modeling,” Lucas said. “We will have to go to better methods of [optical proximity correction].”
Ralph Dammel of EMD Performance Materials reviewed the situation in semiconductor materials as IC gate lengths continue to shrink. “We’re going to move from adding new elements to different forms of elements,” he said, such as graphene, silicine, black phosphorus, and molybdenum disulfide.
At the Lithography Users Forum, the event put on by KLA-Tencor, Mark Phillips of Intel said, “Scaling can continue, but it needs improved metrology.” He added, “We need side-by-side accuracy metrics.”
Phillips reported on Intel’s work with ASML Holding on developing pellicles for the reticles of ASML’s extreme-ultraviolet lithography systems. The companies have together come up with a prototype pellicle, which needs more development as a commercial product, he said.