We examined the potential of using a mirror-electron-microscope (MEM), which has higher sensitivity than optical inspection tools and faster throughput than scanning electron microscopes (SEMs), as a master template inspection tool. We observed line/space patterns with half pitches of 50-100 nm and in which the width of only one space was slightly changed, using the MEM to verify the detection sensitivity of the dimension error. The MEM was able to detect dimension errors larger than 3 nm in the line/space patterns. From observation of the MEM images at various magnifications, we determined that the sensitivity of MEM did not depend exclusively on the resolution power of the image, and that MEM was sufficient for detecting the defects under the resolution power. If we assume that the field of view (FOV) of the MEM image was 30x30 square μm, and the acquisition time per image was 10 ms, the inspection time for the entire 2.5-inch surface of the master template was estimated to be about 10 hours. MEM is therefore a promising candidate for inspecting nanoimprint master templates due to its high sensitivity and acceptable throughput.

Date Published: 24 September 2010
PDF: 6 pages
Proc. SPIE 7823, Photomask Technology 2010, 78230Q (24 September 2010); doi: 10.1117/12.864090

Published in SPIE Proceedings Vol. 7823:
Photomask Technology 2010
M. Warren Montgomery; Wilhelm Maurer, Editor(s)