Ion projection lithography: Status of the MEDEA project and United States/European cooperation

Abstract

Structure and targets of the European MEDEA project on ion projection lithography as well as related U.S./European cooperation are explained. By assuming 10 μm virtual source size and 1 eV (full width half maximum) energy spread calculations for a multielectrode electrostatic ion–optical system (1.25 m between ion source and stencil mask, ≈1.8 m between mask and wafer) we realize the possibility of 100 nm resolution (line and space) over an exposure field of $\text{22×22\hspace{0.17em}}{\mathrm{mm}}^{\mathrm{2}}$ even when using the MONTEC model for calculating the stochastic blur and when running 3.3 μA ${\mathrm{He}}^{\mathrm{+}}$ ion beam current through the ion–optical column, thus more than twice exceeding target specifications. Thus, for 100 nm resolution and 50% pattern density the raw throughput is ≈12 cm²/s corresponding to >75 WPH (pattern within 80% of 300 mm wafer area).