Exploring the electron density in plasma induced by EUV radiation: I. Experimental study in hydrogen

Abstract

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Ion energy distributions in highly transient EUV induced plasma in hydrogen

“…The smallest Debye length is estimated using an electron temperature of 1 eV and a peak density of 3 Â 10 16 m -3 measured with MCRS, 22 which was translated from the electric field averaged electron density to the actual density. 26 The resulting Debye length is 43 lm.…”

“…Published by AIP Publishing. 123, 063301-1 resonance spectroscopy (MCRS) 21,22 and a particle-in-cell (PIC) model. 23,24 When the EUV pulse repetition time is much longer than the plasma decay time, the processes in plasma creation and decay are as follows (also illustrated in Fig.…”

“…All energy is supplied within a few tens of nanoseconds by the EUV pulse, while it takes up to a few hundred microseconds for the plasma to completely extinguish. 22 This low duty cycle (10 -4 ) makes the plasma highly transient.…”

EUV-Induced Plasma: A Peculiar Phenomenon of a Modern Lithographic Technology

“…From 2015 onwards, Microwave Cavity Resonance Spectroscopy (MCRS) has been applied and further developed as non-intrusive, accurate diagnostic to investigate the creation, dynamics, and decay of highly transient pulsed plasma environments under EUVL scanner conditions [11,17,18,21,26,34,35]. The diagnostic has provided experimental data to interpret plasma physical processes on the most fundamental level [16,36] and to verify numerical models since its introduction [17,21]. The basic principles behind MCRS are briefly summarized in the following of this section.…”

“…where e and m e are the charge and mass of an electron, respectively, and ε 0 is the permittivity of vacuum. In practice, MCRS has been applied to EUV-induced plasmas by sending a pulsed EUV beam through a cavity that contained holes in its top and bottom cavity lids for this purpose (see Figure 5) [11,17,18,34,35,50]. Microwave (MW) antennas that are inserted through the cavity wall are used to send in microwave radiation and to record the cavity's response (either in transmission or reflection mode).…”