Resistance is Not Futile
2014 R&D 100 Winner
In lithography, polymer “resists” are applied as a thin, continuous layer over material that is to be patterned. The resist is patterned, then removed after the pattern is duplicated on the silicon underneath. However, smaller patterns demand thinner resists, which can’t survive plasma patterning. Sequential Infiltration Synthesis (SIS) Lithography, developed by Argonne National Laboratory and implemented in industrial settings by several industry leaders, gives the resist the ability to withstand plasma etching. It uses a sequence of gaseous chemical exposures to infiltrate and infuse the polymer with tough ceramic materials. This infusion, which is analogous to atomic layer deposition, is possible because of chemical reactions between precursor vapors and functional groups on the polymer backbone. During the initial stages of the process, “seeds” of the inorganic material are created that are bound to the polymer. Further reactions grow the seeds larger, and the eventual product is a composite material comprised of the organic polymer and the inorganic material that are intimately bound together. The net result of this sequential infiltration synthesis is deeper, more precise patterning of the substrate which can dramatically improve the performance of the resulting microelectronic circuitry.
Argonne National Laboratory
The Sequential Infiltration Synthesis (SIS) Lithography Development Team from Argonne National Laboratory
Seth B. Darling, Principal Developer
Jeffrey Elam, Principal Developer