Infineon Technologies Ag

Qimonda Ag

Andreas Jahnke

Christoph Nölscher

Ralf Ziebold

Torsten Maehr

A photomask for a lithography apparatus includes a chip pattern configured to be transferred into a resist layer on a workpiece and at least one registration mark that is configured not to be transferred into the resist layer. Mask qualification may be improved without impacting wafer level processes.

Mask with registration marks and method of fabricating integrated circuits

A semiconductor wafer is exposed with a pattern from a mask or reticle in an exposure tool. The exposure tool has an adjustable lens system and a light source, which is tunable in wavelength. A first exposure is performed with a tuned first wavelength and a first setting of the lenses. Prior to performing a second exposure onto the same wafer and into the same resist layer, the wavelength of the light source is varied to a second wavelength in order to mimic a focus offset. A resulting image shift at the slit edges of the scanning system due to chromatic aberration is then corrected for by setting the lens system in dependence of the difference between the tuned first and second wavelength. Having tuned second wavelength of the light source and having set the lens system, the second exposure is performed. A continuous adjustment of the lens system based upon a continuously varying light source wavelength can be accomplished.

Growing community of inventors

Radebeul, Germany

Andreas Jahnke