For some applications, local or global pattern placement accuracy is the most crucial requirement for lithography.
Our direct write lithography systems use differential laser interferometers, optical front- and/or backside alignment or in-situ imaging to measure various parameters for accurate positioning on the samples. Climate control chambers and sample chucks made of Zerodur minimize thermal drifts that cannot be easily measured and compensated actively.
Direct-write lithography has key advantages for pattern placement accuracy as compared to mask aligners, steppers or imprint lithography tools that are bound to masks or stamps. Such tools cannot compensate for local or global imperfections from previous fabrication steps, from thermal effects or from bowing. In case of direct write lithography, the layout data can be individually adapted by local and global position matrix corrections (x-scale-errors, y-scale-errors, rotation, translation, orthogonality errors) to compensate for imperfections from the sample or the tool itself.