This paper describes the effect of an axial magnetic field (Bz) on plasma pinch dynamics and on the extreme ultraviolet (EUV) emission property of a compact Z-pinch device for EUV sources. The Z-pinch xenon plasma was driven by a pulse current with an amplitude of 27 kA and duration of 150 ns in an alumina tube with a diameter of 5 mm. A quasistatic magnetic field of up to 360 G is applied to the plasma. The EUV emission was evaluated for spectra, spatial distribution of the emission, and light energy at 13.5 nm with 2% bandwidth. A time-resolved interferogram provides the electron line density and pinch dynamics of the plasma. When a magnetic field of 160 G was applied to the plasma, the emission energy was approximately double that without the magnetic field. The spectroscopic measurement shows that the EUV spectrum drastically varies with magnetic-field strength. The time-resolved interferogram indicates that the axial magnetic field contributes by making the plasma compression smooth and by sustaining certain plasma conditions longer. From these experimental results, it was concluded that applying an axial magnetic field can be an effective method to improve EUV emission.

Extreme ultraviolet (EUV) radiation with wavelengths of 11–14 nm is seen as the most promising candidate for a new lithographic technology. In the development of our Z-pinch plasma EUV source, xenon (Xe) is used for the background gas discharges and a solid tin (Sn) rod is used as target material due to its potential for high conversion efficiency (CE) from input electric energy to EUV radiation. The Z-pinch plasma was driven by pulsed current with amplitude of 30 kA and pulse duration of 110 ns. Pinhole imaging, an EUV spectrograph and an in-band EUV energy monitor were used to characterize the EUV emission from the Z-pinch discharge. Previously reported experimental analyses by Horita et al have demonstrated that the CE was as high as 3%.

This paper describes the characteristics of the EUV light source based on z-pinch discharges, which is driven by a low inductance pulsed current generator. The driving circuit with an inductance of 30 nH is capable of delivering the current of 34 kA in 110 ns to the z-pinch load. The z-pinch xenon plasmas are produced in the ceramic tube with the dimension of 3 or 5 mm in diameter and 5 mm in length. According to plasma dynamics observed by a fast framing camera, there are two radiation modes, one is dynamic and the other is quasi-static. Plasma behaves more dynamically with larger diameter discharge tube. The E W emission fiom the z-pinch plasma was characterized with respect to spectnun and inband E W energy (13.5 am, 2% bandwidth) as well as temporal behavior of the emission. Presently the maximum in-band E W energy is 11 d / s r in the direction of 15 degree off-axis.

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Abstrucr-In the development of our Zpinch plasma EUV source, xenon (Xe) is used for the background gas discharges, and a solid tin (Sn) rod is used as target material due to its potential of high convention efficiency (CE) from input electric energy to EUV radiation I1,Zj. The Zpinch plasma was driven by pulsed current with amplitude of 30 kA and pulse duration of 110 ns. Pinhole imaging, EUV spectrograph and in-band EUV energy monitor were used to characterize the EUV emission from the Zpinch discharge. The experimental analyses have demonstrated the CE was as high as 3% ~31.