ANALYSIS OF THE PROXIMITY FUNCTION IN ELECTRON-BEAM LITHOGRAPHY ON HIGH-T-C SUPERCONDUCTING THIN-FILMS

In this paper we approximate by the combination of double Gaussian and exponential functions the radial distributions of the absorbed electr on energy density in a 125 nm PMMA resist layer on YBa2Cu3O7 thin-film /substrate targets obtained by means of Monte Carlo simulation for a z ero-width delta-function and the following variables (i) the substrate material (SrTiO3 and MgO), (ii) the electron beam energy E(0) (25, 50 and 75 keV) and (iii) the YBa2Cu3O7 film thickness d (0, 100, 200 and 300 nm). The values of the parameters of the analytical function are calculated using an original Monte Carlo technique. These values are p resented in the form of 3D diagrams which show their dependences on be am energy and on high-temperature superconducting film thickness and c an also be used for approximate determination of the parameters at dif ferent initial conditions.