Amorphous hydrogenated carbon (alpha-C:H) thin films deposited by rf chemical vapor deposition were applied to masking the etching of silicon dioxide (SiO2) by the aqueous solution of fluoridric acid (HF). Films with thickness of approximately 100 nm were successfully patterned on SiO2 by the lift-off process. Then the masked samples were submitted to an aqueous HF solution at room temperature. The inspection showed well-defined etching pattern indicating the high performance of the alpha-C:H for this application. (C) 1999 Elsevier Science Ltd. All rights reserved.309833836