PMMA resist profile and proximity effect dependence on the electron-beam lithography process parameters

Abstract The study reveals the influence of the electron-beam lithography parameters (such as the exposure dose, resist thickness, depth) on the resist profile shape in the case of the PMMA (polymethyl-methacrylate) positive resist. The experiments are performed using an Elphy Quantum (Raith) e-beam lithography control system installed on an Inspect F50 (FEI) scanning electron microscope with a field emission cathode and a Gaussian intensity distribution. Profiles developed in the PMMA using the MIBK:IPA 1:3 developer and simulation results based on measurements along the resist profile depth for the case of 30-keV electron energy are presented and discussed. The results contribute to the knowledge on electron scattering in the resist/substrate in electron-beam lithography and assist in the development and approval of simulation tools for prediction and control of resist profiles in thick PMMA layers for lift-off nanopatterning.