Simultaneous exposure of filter gratings and waveguides by direct write electron-beam lithography

A novel process enabling the simultaneous electron-beam exposure of different types of structures is presented, illustrated by the synchronous generation of filter gratings and waveguides. Optimized results for a precise adjustment of the interface waveguide-grating are shown, as well as the necessity for proximity correction achieved by dose assignment. The accomodation of the different address grids makes the pre-fixing of the vertical and horizontal adjustments possible. The structures are then transferred into the semiconductor by means of dry etching. The devices and their characteristic filter curves are presented.