High resolution electron beam lithography with a polydiacetylene negative resist at 50 kV

Abstract

A polydiacetylene with urethane substituents is shown to have high resolution, when used as a negative electron beam resist. The resist has a wide process latitude and can be developed in chloroform. The minimum feature size, distinguishable point-to-point spacing, linewidth, and line spacing are addressed through exposure test patterns of single pass line and pixel arrays. For a Gaussian probe with a 1/e radius of 8.3 nm, minimum feature sizes of 80 nm and minimum array period of 200 nm can be achieved in the resist. The resist exhibits line and isolated pixel sensitivities of ≊4.2 nC/cm and 3.4 fC, respectively, at 50 kV, which are comparable to those of polymethylmethacrylate. The results are analyzed through electron scattering calculations and exposure chemistry.