The ASML 5500/9xx, in the Triangle National Lithography Center (TNLC), is a state-of-the-art, 193 nm optical lithography system for rapid turnaround time and high volume patterning. This stepper is housed in the Class 100 facilities within NC State’s Nanofabrication Facility (NNF). The NNF provides auxiliary capabilities: resist coating, developing, descum, and trim. The stepper specifications include 130 nm resolution (half-pitch) and < 40 nm alignment, with a 26 mm x 33 mm field size. The tool is currently configured for 150 mm wafers.
Previous experience with other steppers suggest that, once the tool lithography processes are optimized, isolated features as small as 65 nm will be able to be printed. Using the resist trimming processes already developed at NC State, features as small as 20 nm are expected. To complete the pattering process, RIE tools are available for film etching. In conjunction with the Strasbaugh 6EC chemical mechanical polishing tool, damascene pattering can be performed. This stepper has a market value of over $10M and represents an investment by UNC-CH and NCSU in excess of $4M.
This stepper is expected to fill an important gap in nanofabrication. On the one hand, using resist-trimming techniques, its resolution and alignment capabilities approach that available with direct write e-beam systems, without imposing as severe a constraint on the substrate and resist materials and their thicknesses. On the other hand, once the masks are made, the high volume capability of the stepper will allow users to quickly pattern many substrates in order to evaluate alternate materials and/or process sequences in their experiments. Since the stepper can productively expose hundreds of wafers per day, it can also be expected to accommodate a number of users with short queuing times.
In addition to patterning nanometer features on device wafers, the stepper is designed to support research programs in 193 nm, 157 nm and EUV resist materials, and in green processing. For example, the NSF Science and Technology Center for Environmentally Responsible Solvents and Processes plans to use the stepper to develop solvent-free lithography and cleaning processes for future device generations. The 193 nm stepper will be the center-piece of the “Dry FAB of the Future” demonstration facility associated with our NSF Science and Technology Center. Systems to coat and develop resists using liquid and supercritical CO2 will be an integral part of the TNLC.