20. How high is the solvent resistance of photoresist films?
With respect to the source materials used, photoresists fall into two different categories:
- PMMA resists (protective coating AR-PC 5000/4, -503, 504, SX AR-N 4800)
- Novolak resists (AR-P 3000, AR-N/U 4000, a few 5000)
» The general rule is that with increasing bake- or process temperature, the solubility of the resist films decreases. This is reflected by gradually increasing removal problems.
Easily soluble in: acetone, MEK, PMA (PGMEA), NMP, chlorobenzene, ethylbenzene, anisol, MIBK, ethyl lactate;
Not soluble in: water, isopropanol, ethanol, nonan, and the like.
Easily soluble in: acetone, MEK, PMA (PGMEA), NMP, anisol, MIBK, isopropanol, ethanol, butyl acetate, ethyl lactate;
Not soluble in: water, chlorobenzene, ethylbenzene, nonan, and the like.
Abbreviations of solvents and raw materials used: MEK: methyl ethyl ketone; PMA (= PGMEA): 1-methoxy-2-propyl acetate, NMP: N-methyl-2-pyrrolidone, MIBK: methyl isobutyl ketone, TMAH: tetra methyl ammonium hydroxide, KOH: caustic potash solution, HF: hydrofluoric acid