Speaker
Jeroen Westerhout
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.3014.pdf
First characterization of ion fluxes in repetitively pulsed hydrogen plasma
induced by 13.5 nm EUV radiation at the EBL2 facility
J. Westerhout1, M.F. Dekker1, R.P. Ebeling1, T. Huijser1, N.B. Koster1, K.L. Nicolai1, M.
van Putten1, A.J. Storm1, A. Ushakov1, J. van Veldhoven1
1
TNO, Stieltjesweg 1, 2628 CK Delft, The Netherlands
The current paper describes the properties of 13.5 nm extreme ultraviolet (EUV) radiation
induced hydrogen plasma in the exposure chamber of the new EUV beam line (EBL2) at
TNO. The introduction of higher source powers in EUV lithography systems causes
increased risks for contamination and degradation of EUV photomasks and pellicles.
Appropriate testing can help to make an inventory and mitigate these risks. To understand
the influence of plasma produced due to gas photoionization on tooling and components, a
more detailed description of such plasma is required. In EBL2 samples (including EUV
photomasks) can be exposed to EUV radiation in a controlled environment. This allows for
a systematic parameter study of EUV plasma. 3 kHz repetitively pulsed plasma conditions
are characterized with compact a retarding field ion energy spectrometer, measuring time and
space resolved ion flux and ion energy profiles on the chamber walls. Plasma profiles as a
function of gas pressure, beam and chamber geometry, as well as plasma decay times are
discussed.
