Organic coating composition are provided including antireflective coating compositions that can reduce reflection of exposing radiation from a substrate back into an overcoated photoresist layer and/or function as a planarizing or via-fill layer. Preferred organic coating compositions of the invention comprise one or more resins that can harden upon thermal treatment without generation of a cleavage product. Particularly preferred organic coating compositions of the invention comprise one or more components that comprise anhydride and hydroxy moieties.