US Patent 7811747 Method of patterning an anti-reflective coating by partial developing

A method of patterning a thin film is described. The method comprises forming a thin film to be patterned on a substrate, forming a developable anti-reflective coating (ARC) layer on the thin film, and forming a mask layer on the developable ARC layer. Thereafter, the mask layer is patterned to form a pattern therein, and the pattern is partially transferred to the developable ARC layer using an imaging and developing process. Once the mask layer is removed, the pattern is completely transferred to the developable ARC layer using an etching process, and the pattern in the developable ARC layer is transferred to the underlying thin film using another etching process.