Acid blend for removing etch residue
AssigneeMicron Technology, Inc.
InventorsKevin J. Torek, Donald L. Yates
Life of this patent
Estimating the term…
Abstract
A method for removing organometallic and organosilicate residues remaining after a dry etch process from semiconductor substrates. The substrate is exposed to a conditioning solution of a fluorine source, a non-aqueous solvent, a complementary acid, and a surface passivation agent. The fluorine source is typically hydrofluoric acid. The non-aqueous solvent is typically a polyhydric alcohol such as propylene glycol. The complementary acid is typically either phosphoric acid or hydrochloric acid. The surface passivation agent is typically a carboxylic acid such as citric acid. Exposing the substrate to the conditioning solution removes the remaining dry etch residues while minimizing removal of material from desired substrate features.
Claims12
A conditioning solution comprising:
- a fluorine source, said fluorine source being selected from the group consisting of hydrofluoric acid, ammonium fluoride, and other fluorine donating chemicals;
- a complementary acid, said complementary acid being selected from the group consisting of phosphoric acid, hydrochloric acid, and combinations thereof;
- a non-aqueous solvent, said non-aqueous solvent being selected from the group consisting of tetrahydrofuran, propylene carbonate, and blends thereof;
- and
- a surface passivation agent comprising ascorbic acid, wherein said conditioning solution is substantially free of water, and said fluorine source, said complementary acid, said non-aqueous solvent and said passivation agent are present in said conditioning solution in concentrations suitable for the selective removal of residues relative to any exposed metal on a semiconductor substrate.
A conditioning solution configured to selectively remove residues remaining on a semiconductor substrate after a dry etch process relative to exposed metal, said conditioning solution comprising:
- hydrofluoric acid or ammonium fluoride;
- hydrochloric acid or phosphoric acid;
- tetrahydrofuan or propylene carbonate;
- and
- ascorbic acid or ethylene diamine tetraacetic acid acting as a surface passivation agent, wherein said conditioning solution is substantially free of water.
A conditioning solution configured to remove residues remaining on a semiconductor substrate after a dry etch process relative to exposed metal, said conditioning solution consisting essentially of:
- about 0.27% molecular HF and H2F2;
- about 91.5% to about 97.5% propylene glycol;
- about 6.5% H2PO4 or about 0.006% HCl;
- about 0.25% citric acid;
- and
- no more than about 2% water.
Dependencies are inferred from the claim text.