Journal of Vacuum Science & Technology B, Vol.18, No.6, 2986-2989, 2000
Performance of a compact beamline with high brightness for x-ray lithography
We have developed a short beamline with high brightness for x-ray lithography. The beamline contains a single, a scanning toroidal mirror and a vacuum protection system with an acoustic delay line. The practical exposure intensity on a wafer was approximately 50 mW/cm(2) at stored electron current of 500 mA. Dose uniformity of +/-2.8% was achieved in a 26 mmX26 mm exposure area by optimizing the scan speed. Minimum resolution of 80 nm was obtained with a 15 mum gap. The optimum dose for TDUR-N908 (Tokyo Ohka) was 1300 mA s, which corresponds to exposure time of 2.6 s when the stored electron current is 500 mA. Since the sensitivity of TDUR-N908 is 110 mJ/cm(2), the beam intensity in our beamline is estimated to be 43 mW/cm(2). By reducing the exposure field, a beam intensity of more than 50 mW/cm(2) can be achieved.