FABRICATION OF 0.1 MU-M PATTERNS USING AN ALTERNATING PHASE-SHIFT MASK IN ARF EXCIMER-LASER LITHOGRAPHY

We demonstrate applications of alternating phase shift mask (Alt-PSR I ) techniques to ArF excimer laser lithography with a numerical apertur e of 0.6 and a coherence factor of 0.3. A 0.10 mu m line-&-space (L/S) pattern was fabricated using a single-layer resist and a 0.09 mu m L/ S pattern was fabricated using a silylation resist. However, the proce ss window was smaller for the silylation resist than for the single-la yer resist over the 0.10-0.13 mu m L/S range. The maximum depth of foc us (DOF) values were approximately 0.3, 0.5; and 0.9 mu m for 0.10, 0. 11, and 0.13 mu m L/S patterns, respectively, for the single-layer res ist. From exposure dose-DOF-tree analysis, we estimated the inclusive process margin including the critical dimension difference, the DOF, t he dose margin, and the phase error. Assuming that the usable DOF is l arger than 0.5 and 0.6 mu m for 0.11 and 0.13 mu m L/S patterns, respe ctively, the inclusive process margin for the single-layer resist is p oor in comparison with future predictions.