Generation of atomic H and O vacuum ultraviolet emissions in high-pressure dielectric barrier discharge plasmas and microhollow cathode discharge plasmas in Ne-H2 and Ar-O2 gas mixtures

As the semiconductor industry pushes toward ever smaller chip feature sizes (< 100 nm), ever shorter wavelengths are sought for the photolithographic process used in their fabrication. We used two types of plasma-based light sources for the generation of near-monochromatic vacuum ultraviolet atomic hydrogen (121.6 nm) and oxygen (130.6 nm) line emissions, (i) a variant of a dielectric barrier discharge and (ii) a microhollow cathode discharge. When operated in high-pressure mixtures of Ne (Ar) with a trace admixture of H2(O2) both sources emit intense, near-monochromatic atomic line H and O emissions. The underlying microscopic processes have been identified as near-resonant energy transfer from Ne2* to H2 and resonant absorption of Ar2* excimer radiation by O atoms produced from O2 in the plasma, respectively. (author)