9 November 2015 Low-line edge roughness extreme ultraviolet photoresists of organotin carboxylates
Author Affiliations +
J. of Micro/Nanolithography, MEMS, and MOEMS, 14(4), 043506 (2015). doi:10.1117/1.JMM.14.4.043506
Pure thin films of organotin compounds have been lithographically evaluated using extreme ultraviolet lithography (EUVL, 13.5 nm). Twenty 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 photosensitivity is linearly related to the molecular weight of the carboxylate group bound to tin. Additionally, photosensitivity was found to be linearly related to free radical stability of the hydrocarbon group bound directly to tin (R=phenyl, butyl, and benzyl). 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 (1) achieved 1.4 nm LER at 22-nm half-pitch patterning and a resist composed of (C6H5CH2)2Sn(O2CC6H5)2 (2) 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(O2CCHCH2)2 (3) and (C6H5CH2)2Sn(O2CC(CH3)CH2)2 (4), demonstrated better photospeeds (5  mJ/cm2 and 27  mJ/cm2) but worse LER.
© 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)
Ryan Del Re, James Passarelli, Miriam Sortland, Brian Cardineau, Yasin Ekinci, Elizabeth Buitrago, Mark Neisser, Daniel A. Freedman, Robert L. Brainard, "Low-line edge roughness extreme ultraviolet photoresists of organotin carboxylates," Journal of Micro/Nanolithography, MEMS, and MOEMS 14(4), 043506 (9 November 2015). https://doi.org/10.1117/1.JMM.14.4.043506


Line edge roughness

Optical lithography

Photoresist materials

Extreme ultraviolet lithography

Extreme ultraviolet



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