Application of ELN-200 in deep X-ray lithography
The negative tone electron beam resist ELN-200 has been developed in 80th years of the 20th century for thin film patterning. The sensitivity of the resist to X-rays has also been studied [E.S.Gluskin, A.A.Krasnoperova, G.N.Kulipanov, V.P.Nazmov, V.F.Pindurin, A.N.Skrinsky, V.V.Chesnokov, Experiments on X-ray lithography using synchrotron radiation from the VEPP-2M storage ring, Nuclear Instr.Meth. in Phys.Res.,v.208(1983) 393-398]. In the actual work, the X-ray lithographic properties of the resist have been studied after 33 years of storage. It was established that the contrast and the sensitivity of the resist to X-rays are not changed. The conditions of both formation of thick resist layers and manufacturing of high aspect ratio microstructures using hard X-rays are developed. The microstructures of up to 70 um in height have been manufactured. The roughness of vertical sidewalls of the microstructures doesn't exceed 50 nanometers.