Abstract
Resolution capability of synchrotron radiation based proximity lithography has been investigated in the sub-quarter micrometer range using an advanced X-ray stepper and high resolution SiC/W X-ray masks. High resolution tungsten gratings and single lines as small as 60 nm are now currently available. Such masks were tested by contact printing in the L2M lithography station implemented at Super-ACO synchrotron facility in Orsay-France. Also, the influence of diffraction on feature sizes was studied with 30-40 µm proximity gap using various positive and negative resists: PMMA, RAY-PF, SAL 601. It was found that 0.10 to 0.12 µm linewidths can be achieved for gratings and 0.15 to 0.20 µm for isolated lines. This resolution limit can be overpassed by a double exposure technique associated with a lateral mask-stage translation. Examples of feature size down to 80 nm were readily achieved at 40 µm gap.