Pattern Transfer Process Using Spun-on Carbon Film for KrF and ArF Lithography

抄録

Dry etch resistance and antireflective performance were studied for a spun-on carbon film containing 90.4wt% of carbon. The refractive index of the spun-on carbon film at KrF wavelength (248nm) is n=2.17, k=0.37 and that at ArF wavelength (193nm) is n=1.44, k=0.39. The bilayer BARC system composed of upper spun-on glass (SOG) and lower spun-on carbon was evaluated. It reduces the reflectivity to 1% for KrF wavelength and 0.5% for ArF wavelength and the variation of the substrate thickness can be ignored. Resist profiles are obtained without any footing, residue, or standing-wave. The etch resistance of the spun-on carbon film is 1.3 times greater than that of the thermally oxidized novolak film (i.e., conventional under-layer for trilayer resist process).