No abstract

A lithography beam line, as the first of possibly six or more, has been installed in the Hefei Synchrotron Radiation Laboratory (HESYRL). A scanning mirror is used to cut off shorter wavelengths and to expand exposure dimensions vertically. The scanning mirror is oscillated by a stepping motor while an in-situ Moire fringe grating system measures motor speed uniformity. Some testing results are given. In the first part of the beam line, there is a beryllium window to block longer wavelength light, a laser alignment unit to align the beam line and a special exposure shutter, which is controlled by another stepping motor. An exposure chamber with vacuum of 5 x lO-'torr is located 7 meters downstream from the source point. Because there is no window at the entrance of the chamber, a differential pumping system is needed. The chamber is equipped with a mask-wafer system, driven by a third stepping motor.

SSRF is theˆrst third generation light source in China. The storage ring vacuum system will adopt SS 316LN chambers with antechambers and discrete absorbers. Several chamber models using SS 316L were developed. There are three types of absorbers. TSP and (SIP＋NEG) combined pumps will be used. A model of (SIP 2001/s＋NEG WP1250) was developed. The vacuum system in total cell will be pre-baked before installing, then in-site baking will not be adopted. RF shielded bellows containing a singleˆnger shielding structure and the high precision BPM section have been designed.

The lithography beamline design of Hefei National Synchrotron Radiation Laboratory is presented. A scanning mirror is used to cut off short wavelength radiation and to expand the vertical exposure dimension to 50 mm. A thin beryllium window is installed before the scanning mirror to prevent the longer wavelength radiation from going through. An exposure chamber with a vacuum of 5×10E−7 Torr is located at 7 m downstream from the source point. Because there is no window at the entrance of the chamber, a differential pumping system is used. The scanning mirror is driven by a stepping motor which oscillates through a 1° angle. The required driving speed curve is determined by a computer in order to obtain a uniform exposure area. An in situ moiré fringe grating system is used to measure the uniformity of the motor speed.