How high is the solvent resistance of photoresist films?

With respect to the raw materials used, photoresists fall into two different categories:

• PMMA resists (protective coating AR-PC 5000/4, -19, -30, and SX AR-N 4800)
• SX AR-PC 5000/40
• Novolac 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.

PMMA resists:
Easily soluble in: acetone, MEK, PMA (PGMEA), chlorobenzene, ethylbenzene, anisole, MIBK
Particular in: NMP, ethyl lactate
Not soluble in: water, isopropanol, ethanol, nonane, and the like.
SX AR-PC 5000/40
Well soluble in: chlorobenzene, ethylbenzene
Not soluble in: anisole, MIBK, ethyl lactate, and the like.

Novolac resists:
Well soluble in: acetone, MEK, PMA (PGMEA), anisole, MIBK, butyl acetate
Particular in: isopropanol, NMP, ethanol, ethyl lactate
Not soluble in: water, chlorobenzene, ethylbenzene, nonane, 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