Influence of Ne-Xe gas mixture ratio on the extreme ultraviolet (EUV) emission and electron temperature from the coaxially focused plasma

Abstract

Summary form only given. The Ne-Xe plasmas in dense plasma-focus device with coaxial electrodes have been generated for extreme ultraviolet (EUV) lithography. The influence of Ne-Xe gas mixture ratio, in which Xe contents are 1, 10, 15, 20, 25, 30, and 50 % to the Ne gas, on the EUV emission, EUV intensity and electron temperature have been investigated in the coaxially focused plasma. An input voltage of 4.5 ~ 6kV has been applied to the capacitor bank of 1.53uF and the diode chamber has been filled with Ne-Xe mixture gas at a optimized pressure of 25 mTorr. The inner surface of the cylindrical cathode was covered by an acetal insulator. The anode has been made of tin metal. The wavelength of the EUV emission has been measured to be in the range of 6 ~ 16 nm by a photo-detector (AXUV-100 Zr/C, IRD). The visible emission line has been also measured by the compositegrating spectrometer with the working wavelength range of 200 ~ 1100nm (HR 4000CG). The electron temperature is obtained by the optical emission spectroscopy (OES) and measured by the Boltzmann plot under the assumption of local thermodynamic equilibrium (LTE).