APPLICATION OF AN X-RAY STEPPER FOR SUBQUARTER MICROMETER FABRICATION

We report on a study of proximity x-ray lithography with a commercialized x-ray stepper (Karl Suss XRS200) and synchrotron orbital radiation at Super-ACO (Orsay, France). Special attention has been paid to the replication capabilities using SiC/W based high-resolution x-ray masks. The results show that proximity printing at a gap of 40 mum can result in subquarter micrometer replication. Since the resolution of the proximity printing is limited by the Fresnel diffraction, we use a double exposure technique to generate higher density and higher resolution grating structures. Fabrication of sub-100 nm linewidth gratings has been achieved using this technique with a wide exposure latitude.