Plasma‐deposited organosilicon thin films as dry resists for deep ultraviolet lithography

Organosilicon thin films have been formed by plasma enhanced chemical vapor deposition and employed as deep‐UV photoresists. Films 20–200 nm thick were deposited from liquid organosilicon sources onto carbon‐based planarizing layers and patterned in projection with a 193 nm excimer laser. At fluences below ∼5 mJ/cm2/pulse, exposure to 193 nm radiation induced oxygen incorporation into the film. Following either a wet or dry development step, negative‐tone imaging was achieved, with the remaining photooxidized film being highly resistant to the O2 reactive ion etching employed in the subsequent pattern transfer step. At higher fluences, ∼15 mJ/cm2, positive‐tone imaging by self‐development was obtained for single‐pulse exposures.