Design of Novel Lithographic Strategies Through Application of Electromagnetic and Multiphysics Simulations

J.P. Singer, J. Lee, S. Ni, M.A. Gibson, S.E. Kooi, and E.L. Thomas
Massachusetts Institute of Technology, Cambridge, MA, USA

Large area patterning techniques such as interference lithography or self-assembly provide 3D nanoscale structures, but lack arbitrary control over what regions are patterned. 3D direct write (DW) lithographic techniques such as multiphoton lithography (MPL) possess the capability to fabricate nearly arbitrary patterns; however, due to the serial nature of DW, fabrication is slow relative to other forms of lithography. Utilizing COMSOL Multiphysics, we have approached combinations of large area techniques with DW lithography. By predefining a periodic pattern in the material by either variation of refractive index, concentration of photoacid, or local composition, DW can then be used to either supply electromagnetic or thermal energy to subsequently create complex aperiodic or hierarchical structures with nanoscale features. In this way we can take advantage of the speed of the large area patterning and still retain some of the arbitrary control of DW. COMSOL was also employed to determine the expected optical response of fabricated structures such as resonators.