STABILITY AND ELECTRONIC ADJUSTMENT OF ION IMAGES PROJECTED AT 10X-REDUCTION

An ion projection system was tested to demonstrate the long-term stability of lithographic properties. By exposing a resist to He+ ions, the pattern from an open stencil mask was transferred by a surface imaging process into the resist. Even after 12 min exposure the resolution capability still gave patterns of a minimum linewidth of 150 nm. Shifts of the pattern with high accuracy and reproducibility were performed by an octopole deflection unit. A projection mode, which consists of multiple exposures each with a different pattern displacement, was established by activating electric dipole fields. A deflection factor of 3.3 mum/V was obtained. Inducing a quadrupole field, changes in demagnification of opposite signs in x and for y directions (anamorphism) were generated which can be used to compensate for different types of distortion. A relative compression as well as expansion factor of 1.7X10(-4) V-1 was determined. Simple two-dimensional simulation of quadrupole induced pattern displacements were carried out and compared with experiments.