Multiple-electron-beam-direct-write lithography is one of the promising candidates for next-generation lithography because of its high resolution and ability of maskless operation. In order to achieve the throughput requirement for highvolume manufacturing, miniaturized electro-optics elements are utilized in order to drive massively parallel beams simultaneously. Electron beam drift problems can become quite serious in multiple-beam systems. Periodic recalibration with reference markers on the wafer has been utilized in single-beam systems to achieve beam placement accuracy. This technique becomes impractical with multiple beams. In this work, architecture of a two dimensional beam position monitor system for multiple-electron-beam lithography is proposed. It consists of an array of miniaturized electron detectors placed above the wafer to detect backscattered electrons. The relation between beam drift and distribution of backscattered-electron trajectories is simulated by an in-house Monte Carlo electron-scattering simulator. Simulation results indicate that electron beam drift may be effectively estimated from output signals of detector array with some array signal processing to account for cross-coupling effects between beams.

Date Published: 14 December 2009
PDF: 11 pages
Proc. SPIE 7520, Lithography Asia 2009, 75202K (14 December 2009); doi: 10.1117/12.837048

Published in SPIE Proceedings Vol. 7520:
Lithography Asia 2009
Alek C. Chen; Woo-Sung Han; Burn J. Lin; Anthony Yen, Editor(s)