Stripper for cured negative-tone isoprene-based photoresist and bisbenzocyclobutene coatings
View Patent ↗A chemical stripping solvent composition is provided for removing cured polymeric isoprene and bisbenzocyclobutene (BCB) substances from an inorganic substrate. The stripping composition comprises about 20 to about 30 weight percent anisole, about 20 to about 30 weight percent mesitylene, about 35 to about 55 weight percent of an alkylbenzene sulfonic acid, and may contain methane sulfonic acid (MSA) at 3 to about 10 weight percent, added to remove BCB in the full-cured state. Also provided is a method for stripping cured polymeric organic substances by contacting the polymeric organic substance with the stripping solvent composition at a given temperature and for a period of time sufficient to essentially dissolve and remove cured polymeric substances.
1. A liquid solvating composition for removing cured isoprene photoresist and BCB surface layers from an inorganic substrate comprising a blend of
from about 35 to about 55 weight percent of an alkylbenzene sulfonic acid,
about 20 to about 30 weight percent anisole, and
about 20 to about 30 weight percent mesitylene.
2. A liquid solvating composition of claim 1 , which includes also about 10 weight percent methane sulfonic acid.
3. The composition of claim 1 wherein the alkylbenzene sulfonic acid is dodecylbenzene sulfonic acid.
4. The composition of claim 2 wherein the alkylbenzene sulfonic acid is dodecylbenzene sulfonic acid.
5. In a method for removing cured polymeric layers from an inorganic substrate the improvement characterized in the material to be removed is contacted with the stripping solvent of claim 1 at a temperature which may be as low as room temperature for a period of time sufficient to remove said substance.
6. In a method for removing full-cure isoprene negative photoresists from an inorganic substrate the improvement is characterized in that the isoprene resist to be removed is contacted with the stripping solvent of claim 1 at a temperature not in excess of about 700° C. for a period of time sufficient to remove said substance.
7. In a method for removing full-cure isoprene negative photoresists from an inorganic substrate the improvement is characterized in that the isoprene resist to be removed is contacted with the stripping solvent of claim 2 at a temperature not in excess of about 70° C. for a period of time sufficient to remove said substance.
8. In a method for removing bisbenzocyclobutene (BCB), which has been cured to less than full-cure, from an inorganic substrate, the improvement is characterized in that the BCB to be removed is contacted with the stripping solvent of claim 1 at a temperature not exceeding about 110° C. for a period of time sufficient to remove said substance.
9. In a method for removing bisbenzocyclobutene (BCB), which has been cured to complete full-cure, from an inorganic substrate, the improvement is characterized in that the BCB to be removed is contacted with the stripping solvent of claim 2 at a temperature at 110° C. for a period of time near 45 minutes.
10. In a method for removing polymeric coatings from inorganic substrates which contain metallized areas, the improvement characterized by effecting the removal with the composition of claim 1 such that limited or no galvanic corrosion to dissimilar metals such as titanium-tungsten and soft metals such as aluminum to have an etch rate at ≦2.5 Å/mm. is exhibited.