Pure thin films of organotin compounds have been lithographically evaluated using extreme ultraviolet lithography (EUVL, 13.5 nm). Twenty-one compounds of the type R₂Sn(O₂CR’)₂ were spin-coated from solutions in toluene, exposed to EUV light, and developed in organic solvents. Exposures produced negative-tone contrast curves and dense-line patterns using interference lithography. Contrast-curve studies indicated that the E_max values were linearly related to molecular weight when plotted separately depending upon the hydrocarbon group bound directly to tin (R = butyl, phenyl and benzyl). Additionally, E_max was found to be linearly related to free radical stability of the hydrocarbon group bound directly to tin. Dense-line patterning capabilities varied, but two resists in particular show exceptionally good line edge roughness (LER). A resist composed of an amorphous film of (C₆H₅CH₂)₂Sn(O₂CC(CH₃)₃)₂ (13) achieved 1.4 nm LER at 22 nm half-pitch patterning and a resist composed of (C₆H₅CH₂)₂Sn(O₂CC₆H₅)₂ (14) achieved 1.1 nm LER at 35 nm half-pitch at high exposure doses (600 mJ/cm²). Two photoresists that use olefin-based carboxylates, (C₆H₅CH₂)₂Sn(O₂CCH=CH₂)₂ (11) and (C₆H₅CH₂)₂Sn(O₂CC(CH₃)=CH₂)₂ (12), demonstrated much improved photospeeds (5 mJ/ cm² and 27 mJ/cm²) but with worse LER.

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