Stitching periodic submicron fringes by utilizing step-and-align interference lithography
(Color online) Schematic diagram of the SAIL. (a) Top view and the optical path on the optical table. (b) Front-view and the optical path on the vertical optical bench.
(Color online) Top view diagram of the two-dimensional precision dual-actuator motion stages and the three-axis displacement interferometers.
(Color online) Control architecture of nanopositioning stage.
(Color online) (a) Designed stitch route map (i) and optimal intensity distribution of unit beam [(ii)–(iv)]; details are described in the text. (b) Uniform intensity distribution if the stitching has no misalignment. (c) The intensity would be lower at the overlapping areas with misalignment for the larger step size. (d) The intensity would be higher at the overlapping areas with misalignment for the smaller step size.
(Color online) Schematic diagram showing a metal mask used to extract the central flat-top area of the Gaussian beam to simulate the uniform intensity beam.
(Color online) Photographs of different fringe stitching results. (a) Correction test sample. (b) Vertical stitch. (c) Transverse stitch. (d) Pattern stitching over a full wafer along the designed route.
(Color online) Micrographs of the stitching areas by OM and SEM.
Side-view SEM images of (a) PR patterns, and transferred to Si wafer with different areas, (b) single exposure, (c) single exposure plus dc zone dosage, and (d) double exposure.
Article metrics loading...
Full text loading...