Analysis of the spectra of In XII–XIV and Sn XIII–XV in the far-VUV region

Abstract

The 4p 64d−(4p 65p + 4p 64f + 4p 54d 2) transitions in the spectra of In XIII-Sn XIV and the 4p 64d 2−(4p 64d5p + 4p 64d4f + 4p 54d 3) transitions in the spectra of In XII-Sn XIII are investigated. About 150 spectral lines in the wavelength range 120–160 Å, which is important for projection vacuum UV lithography, have been classified for the first time. The fine structure intervals of the ground state 4p 64d 2 D and the energies of eight levels of the 4p 65p, 4p 64f, and 4p 54d 2 configurations are measured in each spectrum of In XIII and Sn XIV. The energies of all levels of the ground configuration 4p 64d 2 and the energies of 35 levels of the interacting configurations (4p 65p + 4p 64f + 4p 54d 3) are determined in the spectra of In XII and Sn XIII. The resonant transitions 4p 6 1 S 0−4p 54d 1 P 1 in the spectra of In XIV and Sn XV are also identified. The semiempirical parameters of the configurations under study determined by mean-square fitting of measured level energies are in agreement along both isoelectronic and isonuclear sequences of the spectra.