Modelling of x-rays and EUV-rays emitted from laser produced tin plasmas

The Ni-like and Co-like X-rays and extreme ultraviolet radiation emitted from laser produced tin plasmas were simulated by using hydrodynamic and atomic physics code EHYBRID. X-rays emitted from laser produced plasmas are used in lithography, spectroscopy, microscopy, holography applications and x-ray laser production. Extreme ultraviolet radiation emitted from laser produced plasmas is used in extreme ultraviolet lithography so called next generation lithography. First of all, X-ray resonance lines emitted from Sn plasma created by Nd:YAG laser pulses were modelled. Conversion efficiency of x-ray was calculated and dependence of conversion efficiency to laser intensity and pulse duration were examined. After that, a tin plasma was created by Nd:YAG double pulses at the fundamental wavelength, 2nd harmonic and 3rd harmonics and x-ray conversion efficiencies were calculated. Extreme ultraviolet radiation between 11-17 nm emitted from laser produced tin plasmas were simulated and conversion efficiencies were calculated. Pre-pulses were used to increase conversion efficiency. The effects of delay time, pre-pulse and main pulse durations were investigated. The laser wavelength, also affects the conversion efficiency, so Nd:YAG laser pulses at fundamental, 2nd harmonic, 3rd harmonic and 4th harmonic wavelength used to produce plasmas. Opacity effects on conversion efficiency are exteremely important therefore, opacity effects on x-rays and extreme ultraviolet radiation emitted from laser produced tin plasmas were estimated using an escape factor calculation. Keywords : Laser produced plasmas, x-rays, extreme ultraviolet radiation, conversion efficiency.