title: Nanoscale patterning on insulating substrates by critical energy electron beam lithography.
abstract: This Letter describes a method to generate nanometer scale patterns on insulating substrates and wide band gap materials using critical energy electron beam lithography. By operating at the critical energy (E2) where a charge balance between incoming and outgoing electrons leaves the surface neutral, charge-induced pattern distortions typically seen in e-beam lithography on insulators were practically eliminated. This removes the need for conductive dissipation layers or differentially pumped e-beam columns with sophisticated gas delivery systems to control charging effects. Using a "scan square" method to find the critical energy, sub-100 nm features in 65 nm thick poly(methyl methacrylate) on glass were achieved at area doses as low as 10 microC/cm2 at E2 = 1.3 keV. This method has potential applications in high-density biochips, flexible electronics, and optoelectronics and may improve the fidelity of low voltage e-beam lithography for parallel microcolumn arrays.
authors.affiliation: The Center for Bits and Atoms, MIT Media Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Jaebum
authors.initials: J
authors.lastname: Joo
authors.forename: Brian Y
authors.initials: BY
authors.lastname: Chow
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Jacobson
mesh_terms: D004553:Electric Conductivity; D018499:Linear Energy Transfer; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D010781:Photography / Q000379:methods; D019904:Polymethyl Methacrylate / Q000737:chemistry* / Q000528:radiation effects; D011829:Radiation Dosage; D013499:Surface Properties
chemical_list: D019904:Polymethyl Methacrylate