PMMA characterization and optimization for Nano Structure formation

Abstract

The limitations imposed on optical lithography by the wavelength of light have been overcome using electron lithography. Electron lithography offers high resolution because of the small wavelength of the 10-50 keV electrons and not sensitive in near UV. The resolution of electron lithography systems is limited by electron scattering in the resist not by the diffraction. One of the limitations of the resolution is resist thickness besides of beam energy and substrate compositions. Resist thickness is controlled by many factors such as velocity of the spinner, solid content and the viscosity of the resist. The resist commonly used on electron lithography is PMMA or Polymethyl-Methacrylate. In this paper, the effect of three parameters (as concerned above) on resist thickness is focused.