Solution for the selective removal of metal from aluminum substrates
View Patent ↗The present disclosure relates to a solution for selectively removing metal, such as Ta or TaN, from a substrate, such as an aluminum containing substrate. The solution comprises an acid, such as HF or buffered HF, an ingredient comprising a fluorine ion, such as ammonium fluoride (NH 4 F), ethylene glycol, and water. A method of selectively removing metal from a substrate using this solution is also disclosed.
1. A solution comprising, in weight % of the solution:
1-20% HF, buffered HF, or mixtures thereof, 1-10% of an ingredient selected from the group consisting of ammonium fluoride (NH 4 F), potassium fluoride, sodium fluoride and mixtures thereof,
approximately 50-60% ethylene glycol, and
water.
2. The solution of claim 1 , comprising 10-15% of the HF, buffered HF, or mixtures thereof.
3. The solution of claim 1 , wherein the ingredient is present in amount ranging from 1-5%, by weight, of the solution.
4. The solution of claim 1 , wherein said solution has a pH of less than 6.
5. The solution of claim 1 , further comprising at least one anionic, nonionic, cationic or amphoteric surfactant.
6. The solution of claim 5 , wherein the at least one surfactant is chosen from primary, secondary and tertiary amines of chain length C 2 to C 12 , amides, fluorocarbons and alkylethoxylates.
7. A solution comprising, in weight % of the solution:
1-20% HF, buffered HF, or mixtures thereof,
1-5% NH 4 F,
approximately 50-60% ethylene glycol,
a surfactant, and
the balance of water.