US Patent 7531296 Method of forming high etch resistant resist patterns

A method for forming an etch-resistant photoresist pattern on a semiconductor substrate is provided. In one embodiment, a photoresist layer is formed on the substrate. The photoresist layer is exposed and developed to form a photoresist pattern. A polymer-containing layer is formed over the photoresist pattern. The photoresist pattern and the polymer-containing layer are thermally treated so that polymer is substantially diffused into the photoresist pattern thereby enhancing the etch resistance of the photoresist pattern. The polymer-containing layer is thereafter removed.