CF/sub 4/-RIE development characteristics of columnar-SeGe ion resists with focused-ion-beam lithography

In the very near future, focused-ion-beam lithography (FIBL) may play an important role for the microelectronic device fabrication. In particular, FIBL is evaluated as a novel vacuum technique available to generate original pattern (or masks), with the sub-0.1 /spl mu/m linewidth for X-ray lithography (or ion-projection lithography). In order to delineate a fine pattern, it is essential to develop a lithographic tool with high resolution and a resist with high sensitivity. In this work, the sub-0.1 /spl mu/m patterning characteristics of the columnar structural Se-Ge resists have been studied using low-energy Ga/sup +/-FIB exposure and CF/sub 4/ reactive-ion-etching (RIE) development. The Se-Ge ion resists were normally (0/spl deg/) and obliquely (60/spl deg/ and 80/spl deg/) deposited on Si substrate and parts of resists were annealed for several minutes at glass transition temperature (T/sub g//spl sim/220/spl deg/C). After annealing, FIB exposure and CF/sub 4/-RIE development were performed. For 80/spl deg/-obliquely deposited and T/sub g/-annealed resist, the threshold dose (D/sub 1/) is evaluated to be approximately 7/spl times/10/sup 14/ [ions/cm/sup 2/], which corresponds to half of that for non-annealed 0/spl deg/-resist. The fine patterns with about 0.06/spl sim/0.09 /spl mu/m linewidths were obtained successfully for an exposure just above D/sub 1/.