Azide-Functionalized Organotin Carboxylate Lithography Resist

Extreme ultraviolet (EUV) lithography necessitates photoresists that simultaneously exhibit molecular-scale resolution, high sensitivity, low roughness, and minimal film thickness loss under ultrathin conditions. However, conventional organotin carboxylate resists frequently suffer from extensive ligand detachment and outgassing, which result in void formation, film shrinkage, and diminished pattern fidelity. This paper reports azide-functionalized organotin carboxylates that leverage azide-derived radical chemistry to overcome these limitations. Incorporating 2-azidoacetate or 4-azidobenzoate ligands into a mononuclear Sn carboxylate framework redirects the dominant exposure pathway from simple Sn–O–Sn network formation to nitrene-mediated ligand cross-linking. Consequently, the optimized azide-containing resist exhibits a substantially lower exposure threshold, lower line-edge and line-width roughness, and significantly better thickness retention than its azide-free counterpart, yielding thicker and more uniform patterns from the same initial film. This work demonstrates that azide engineering of organotin EUV resists can be an effective molecular design strategy enabling robust, high-resolution patterning suitable for next-generation semiconductor manufacturing.