FABRICATION OF SUB-100NM LINEWIDTH X-RAY MASKS AND REPLICATION USING SYNCHROTRON RADIATION AT SUPER-ACO

A high resolution x-ray mask technology has been developed based on amorphous silicon carbide covered with stress minimized W and Au patterns. SiC blanks are fabricated from silicon wafers coated with low stress stoechiometric SiC deposited by rf low frequency (110 kHz) glow discharge decomposition of silane and methane (PECVD). Mask absorber pattern fabrication is performed by electron-beam lithography with a single resist layer process. These masks have been tested in the lithography station implemented by our laboratory at Super-ACO using synchrotron radiation in the spectral range 0.5-1.5 nm. Sub-100 nm replication patterns obtained by contact printing in PMMA resist are presented. Results of the evaluation of the x-ray resists SAL 601 and SAL 603 used with the Karl Suss stepper XRS 200 are also described.