In one embodiment, the present invention relates to a method of forming a metal line, involving the steps of providing a semiconductor substrate comprising a metal layer, an oxide layer over the metal layer, and a silicon oxynitride layer over the oxide layer; depositing an ultra-thin photoresist over the silicon oxynitride layer, the ultra-thin photoresist having a thickness less than about 2,000 Å; irradiating the ultra-thin photoresist with electromagnetic radiation having a wavelength of about 250 nm or less; developing the ultra-thin photoresist exposing a portion of the silicon oxynitride layer; etching the exposed portion of the silicon oxynitride layer exposing a portion of the oxide layer; etching the exposed portion of the oxide layer exposing a portion of the metal layer; and etching the exposed portion of the metal layer thereby forming the metal line.