Position accuracy evaluation of multi-column e-beam exposure system

Authors are developing a 50kV e-beam direct writer MCC8 [1] with 8 column cells that enables a throughput of 5 wafers per hour. By March 2010, the concept of MCC had been proven with manufacturing the proof-of-concept system (MCC-POC; four column cells) in the Mask-D2I project of Association of Super-Advanced Electronics Technologies (ASET). Following the Mask-D2I project, the development has being focused on improving the position accuracy with MCC-POC system as a direct write tool. The effort is expected to bring a smooth transition to MCC8. In this paper, newly equipped correction technologies for improving the position accuracy is introduced; and the exposure results of field stitching, inter column-cell(CC) stitching, and mix-and-match overlay on Si wafer are presented. Almost the same accuracy results among all CCs are obtained. Mix-and-match overlay result is 5 nm in 3-sigma. Although inter-CC stitching is not required in device manufacturing, but it will be shown as a part of pure evaluation of the tool performance with the result of 5 nm in 3-sigma.