Amplitude-modulated electrostatic nanolithography in polymers based on atomic force microscopy

Amplitude modulated electrostatic lithography using atomic force microscopy (AFM) on 20–50 nm thin polymer films is discussed. Electric bias of AFM tip increases the distance over which the surface influences the oscillation amplitude of an AFM cantilever, providing a process window to control tip-film separation. Arrays of nanodots, as small as 10–50 nm wide by 1–10 nm high are created via a localized Joule heating of a small fraction of polymer above the glass transition temperature, followed by electrostatic attraction of the polarized viscoelastic polymer melt toward the AFM tip in the strong (108–109 V/m) nonuniform electric field.