Preliminary results at the ultra deep X-ray lithography beamline at CAMD

The Center for Advanced Microstructures and Devices (CAMD) at Louisiana State University supports one of the strongest programs in synchrotron radiation microfabrication in the USA and, in particular, in deep X-ray lithography (DXRL). Synchrotron radiation emitted from CAMD's bending magnets has photon energies in the range extending from the infrared to approximately 20 keV. CAMD operates at 1.3 and 1.5 GeV, providing characteristic energies of 1.66 and 2.55 keV, respectively. CAMD bending magnets provide a relatively soft X-ray spectrum that limits the maximal structure height achievable within a reasonable exposure time to approximately 500 mu m. In order to extend the X-ray spectrum to higher photon energies, a 5 pole 7T superconducting wiggler was inserted in one of the straight sections. A beamline and exposure station designed for ultra deep X-ray lithography (UDXRL) was constructed and connected to the wiggler. First exposures into 1 mm and 2 mm thick PMMA resist using a graphite mask with 40 mu m thick gold absorber has been completed.