TY  - JOUR
AU  - Lu, Haoyan
AU  - Odstrčil, Michal
AU  - Pooley, Charles
AU  - Biller, Jan
AU  - Mebonia, Mikheil
AU  - He, Guanze
AU  - Praeger, Matthew
AU  - Juschkin, Larissa
AU  - Frey, Jeremy
AU  - Brocklesby, William
TI  - Characterisation of engineered defects in extreme ultraviolet mirror substrates using lab-scale extreme ultraviolet reflection ptychography
JO  - Ultramicroscopy
VL  - 249
SN  - 0304-3991
CY  - Amsterdam
PB  - Elsevier Science
M1  - FZJ-2024-02417
SP  - 113720 -
PY  - 2023
AB  - Ptychography is a lensless imaging technique that is aberration-free and capable of imaging both the amplitude and the phase of radiation reflected or transmitted from an object using iterative algorithms. Working with extreme ultraviolet (EUV) light, ptychography can provide better resolution than conventional optical microscopy and deeper penetration than scanning electron microscope. As a compact lab-scale EUV light sources, high harmonic generation meets the high coherence requirement of ptychography and gives more flexibilities in both budget and experimental time compared to synchrotrons. The ability to measure phase makes reflection-mode ptychography a good choice for characterising both the surface topography and the internal structural changes in EUV multilayer mirrors. This paper describes the use of reflection-mode ptychography with a lab-scale high harmonic generation based EUV light source to perform quantitative measurement of the amplitude and phase reflection from EUV multilayer mirrors with engineered substrate defects. Using EUV light at 29.6 nm from a tabletop high harmonic generation light source, a lateral resolution down to and a phase resolution of (equivalent to topographic height variation of 0.27 nm) are achieved. The effect of surface distortion and roughness on EUV reflectivity is compared to topographic properties of the mirror defects measured using both atomic force microscopy and scanning transmission electron microscopy. Modelling of reflection properties from multilayer mirrors is used to predict the potential of a combination of on-resonance, actinic ptychographic imaging at 13.5 nm and atomic force microscopy for characterising the changes in multilayered structures.
LB  - PUB:(DE-HGF)16
C6  - 37004492
UR  - <Go to ISI:>//WOS:000973335500001
DO  - DOI:10.1016/j.ultramic.2023.113720
UR  - https://juser.fz-juelich.de/record/1024751
ER  -