Photoresist developer-soluble organic bottom antireflective composition and photolithography and etching process using the same

A photolithography and etching process comprising:

• forming on a target object to be etched an organic bottom antireflective layer soluble in a developer for a photoresist, the organic bottom antireflective layer containing an aromatic polymer compound having a functional group that absorbs exposure light of a short wavelength of less than about 248 nm and is thermally cross-linkable and de-crosslinkable by acid hydrolysis, a thermal cross-linking agent which causes a thermal cross-linking reaction by reaction with the functional group of the aromatic polymer compound, and an organic solvent;
• thermally cross-linking the organic bottom antireflective layer by baking;
• forming a photoresist layer on the cross-linked organic bottom antireflective layer;
• exposing and then baking the photoresist layer so that hydrolysis by acid occurs in an exposed region of the photoresist layer, and de-crosslinking by acid occurs in the organic bottom antireflective layer underneath the exposed region of the photoresist layer;
• simultaneously forming a photoresist pattern and an organic bottom antireflective layer pattern by dissolving the hydrolyzed exposed region of the photoresist layer and the de-crosslinked organic bottom antireflective layer underneath the exposed region in the developer;
• and
• etching the target object using the photoresist pattern and the organic bottom antireflective layer pattern as an etching mask.