Lift-off Processes with Photoresists

Beside wet or dry etching, lift-off is a common technique to pattern metal or dielectrica films in the μm or sub-μm range. The main criteria for the choice of a photoresist best-suited for a certain lift-off process are: The thickness of the coated material The coating technology (evaporation, sputtering, CVD, ...) and the maximum temperature the resist film has to stand during coating The required resolution The availability of positive or negative photomasks The available exposure wavelengths (g-, h-, i-line) After these questions have been answered, it’s time to look for a resist meeting the requirements of your lift-off process(es) as described in the following sections.