22 March 2018 Overlay and stitching metrology for massively parallel electron-beam lithography
Author Affiliations +
One of the metrology challenges for massively parallel electron beams is to verify that all the beams that are used perform within specification. The Mapper FLX-1200 platform exposes fields horizontally segmented in 2.2 μm-wide stripes. This yields two parameters of interest: overlay is the registration error with respect to a previous layer, and stitching is the registration error between the stripes. This paper presents five novel overlay targets and one novel stitching target tailored for Mapper’s needs and measured on KLA-Tencor Archer 600 image based overlay (IBO) platform. The targets have been screened by exposure of a variable shaped electron beam lithography machine (Vistec VSB 3054 DW) on two different stacks: resist-to-resist and resist-to-etched silicon, both as a trilayer stack. These marks attain a total measurement uncertainty (TMU) down to 0.3 nm and move-and-measure (MAM) time down to 0.3 seconds for both stacks. The stitching targets have an effective TMU of 0.4 nm and a MAM time of 0.75 seconds. In a follow up experiment, the two best performing overlay targets have been incorporated in an exposure by a Mapper FLX-1200. With the new stack a TMU of 0.3 nm and MAM time of 0.35 s have been attained. For 107 out of 140 selected stripes the slope was constant within 2.5%, the offset smaller than 0.5 nm and correlation coefficient R2 > 0.98.
Conference Presentation
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Guido Rademaker, Guido Rademaker, Jonathan Pradelles, Jonathan Pradelles, Stéfan Landis, Stéfan Landis, Stephane Rey, Stephane Rey, Anna Golotsvan, Anna Golotsvan, Anat Marchelli, Anat Marchelli, Tal Itzkovich, Tal Itzkovich, Tetyana Shapoval, Tetyana Shapoval, Ronny Haupt, Ronny Haupt, Erwin Slot, Erwin Slot, Guido de Boer, Guido de Boer, Dhara Dave, Dhara Dave, Marco Wieland, Marco Wieland, Laurent Pain, Laurent Pain, } "Overlay and stitching metrology for massively parallel electron-beam lithography", Proc. SPIE 10585, Metrology, Inspection, and Process Control for Microlithography XXXII, 105850U (22 March 2018); doi: 10.1117/12.2297535; https://doi.org/10.1117/12.2297535

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