Projects

Photoresists are often used in the production of microstructures, with the help of which the desired structures are transferred to the target material. The resist is exposed and then developed, whereby the photoresist takes on the desired structure. During exposure, the photochemical reaction in many photoresists creates so-called latent images, which are characterized by a change in the refractive index in the exposed areas.

Within the scope of this project, these latent images were used as reference marks to determine the origin of the coordinate system in a directly writing polar coordinate laser lithography system and to detect and compensate for the position drift of the equipment during the exposure process, which lasted several hours.

For this purpose, a highly sensitive detection method and the necessary sensors were developed and integrated into the lithography system.

By using a carrier frequency measurement method, a repeatability of < 3 nm could be achieved for determining the coordinates, with a high tolerance for external interference.