US Patent 9916973 Photolithographic methods

Provided are photolithographic methods. The method comprise: (a) providing a semiconductor substrate comprising an organic layer to be etched; (b) applying a layer of a photoresist composition directly on the organic layer, wherein the photoresist composition comprises: a resin comprising an acid cleavable leaving group, the cleavage of which forms an acid group and/or an alcohol group; a photoacid generator; and a solvent; (c) exposing the photoresist layer to activating radiation through a patterned photomask; (d) heating the photoresist layer, wherein acid generated by the acid generator causes cleavage of the acid cleavable leaving group, thereby forming the acid group and/or the alcohol group; (d) developing the exposed photoresist composition layer with an organic solvent developer to form a negative resist pattern comprising the acid group and/or the alcohol group; (e) applying a silicon-containing composition over the resist pattern, wherein the composition comprises a silicon-containing polymer and a solvent and is free of crosslinkers; (f) rinsing residual silicon-containing composition from the substrate, leaving a portion of the silicon-containing polymer on a surface of the resist pattern; and (g) selectively etching the organic layer. The methods find particular applicability in the manufacture of semiconductor devices for providing high resolution patterns.