Photoresist pattern trimming methods

Provided are methods of trimming a photoresist pattern. The methods comprise: (a) providing a semiconductor substrate; (b) forming a photoresist pattern on the substrate, wherein the photoresist pattern is formed from a chemically amplified photoresist composition comprising: a matrix polymer comprising an acid labile group; a photoacid generator; and a solvent; (c) coating a photoresist trimming composition on the substrate over the photoresist pattern, wherein the trimming composition comprises: a matrix polymer, an aromatic acid that is free of fluorine; and a solvent; (d) heating the coated substrate, thereby causing a change in polarity of the photoresist matrix polymer in a surface region of the photoresist pattern; and (e) contacting the photoresist pattern with a rinsing agent to remove the surface region of the photoresist pattern, thereby forming a trimmed photoresist pattern. The methods find particular applicability in the manufacture of semiconductor devices.