The classical remover is acetone which is, together with isopropanol, used as cleaning agent in probably every lab worldwide. The dissolving power of acetone for non- or only low-baked films (up to 120 °C) is excellent. Care must however be taken with respect to the low boiling point (56 °C) and a flashpoint of only -20 °C. Under unfortunate circumstances, already electrostatic charge may cause an explosion. This problem does not occur with NEP (N-ethyl pyrrolidone) or NMP. Both removers have a boiling point of more than 200 °C. The dissolving power is comparable to the power of acetone and may be further enhanced by heating to max. 80 °C (which is harmless with respect to safety concerns, but at this temperature disturbing vapors begin to develop). In principle also other solvents are suitable as removers: IPA, PGMEA (PMA), methyl ethyl ketone (MEK) or thinners (see Thinners) dissolve residuals of not too hard-baked resists. In most cases however considerably more time will be needed if these solvents are used. Solvent removers are equally suitable for novolac-based resists as well as for all polymer resists (e.g. PMMA).
