Chemical mechanical polishing liquid for through-silicon via copper films and uses thereof

Abstract

This invention discloses a chemical mechanical polishing (CMP) slurry for through-hole (TBH) copper films and its applications. The CMP slurry comprises: abrasive particles, an oxidant, a chelating agent, a corrosion inhibitor, and water. The abrasive particles constitute 0.002-20% of the total mass in the CMP slurry and are composed of large-particle and small-particle abrasive particles. The mass ratio of large-particle to small-particle abrasive particles is 1:4 to 3:7. The CMP slurry for TBH copper films provided by this invention mixes abrasive particles of two different sizes in a specific ratio, increasing the contact area between the abrasive particles and the copper film layer during polishing. This achieves a high and adjustable copper film removal rate under relatively low pressure. Furthermore, through improvements to the corrosion inhibitor and the butterfly-shaped depression inhibitor, it improves local and overall corrosion while rapidly removing the copper film, reducing butterfly-shaped depressions in the polished copper.

Claims

1. A chemical mechanical polishing slurry for silicon through-hole copper films, comprising: The mixture comprises abrasive, oxidant, chelating agent, corrosion inhibitor, and water; the abrasive has a mass percentage of 0.002-20% in the chemical mechanical polishing slurry for silicon through-hole copper films, and is composed of large-particle abrasive and small-particle abrasive; the large-particle abrasive has a D50 value of 70nm to 110nm, the small-particle abrasive has a D50 value of 30nm to 50nm, and the mass ratio of the large-particle abrasive to the small-particle abrasive is 1:4 to 3:

7.

2. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 1, wherein, The corrosion inhibitor has a structure of Formula 1; Formula 1; wherein R1 is a straight-chain alkyl group from C7 to C17, R2 and R3 are each independently -H, -CH3, -CH2CH3 or -CH2CH2OH, and m is 2 or 3.

3. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 2, wherein, The corrosion inhibitors include one or more of N-(3-aminopropyl)dodecanoylamine, N-(3-aminopropyl)octylamine, octylaminopropyl dimethyl tertiary amine, decaaminopropyl dimethyl tertiary amine, N-[2-(2-hydroxyethylamino)ethyl]dodecanoylamine, palmitylaminopropyl diethylamine, myristylaminopropyl dimethylamine, N-[2-(diethylamino)ethyl]stearylamine, stearylaminopropyl dimethylamine, stearylaminoethyl diethylamine, N-octadecylaminoethyldiamine, and lauroylaminopropyl dimethylamine.

4. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 1, wherein, The abrasive comprises one or more of SiO2, Al2O3, CeO2, TiO2, ZrO2, Fe2O3 or products thereof, soft abrasives based on organic polymers, and particles surface-modified with silane coupling agents; and / or, the D50 value of the large-particle abrasive is 80 nm to 110 nm, and the D50 value of the small-particle abrasive is 30 nm to 50 nm; and / or, the oxidant comprises one or more of inorganic peroxides, persulfates, organic peroxides, hypochlorous acid, hypochlorite, chloric acid, chlorate, perchloric acid, perchlorate, hypobromic acid, hypobromicate, bromic acid, bromate, perbromic acid, perbromicate, hypoiodic acid, hypoiodide, iodic acid, iodate, periodic acid, periodate, chromic acid, chromate, iron salts, copper salts, ferricyanide, and molybdates; and / or, the chelating agent comprises one or more of amino acids and amino acid derivatives. And / or, the pH of the chemical mechanical polishing solution for the silicon through-hole copper film is 5-9.

5. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 1, wherein, The abrasive comprises one or more of SiO2, Al2O3, and CeO2; and / or, the oxidant comprises one or more of hydrogen peroxide, potassium bromate, potassium iodate, ferric nitrate, sodium hypochlorite, and sodium perchlorate; and / or, the chelating agent comprises one or more of glycine, D-alanine, L-alanine, DL-alanine, β-alanine, valine, leucine, isoleucine, proline, serine, threonine, tyrosine, glutamic acid, aspartic acid, glutamic acid, aspartic acid, tryptophan, histamine, arginine, lysine, methionine, cysteine, and iminodiacetic acid; and / or, the pH of the through-silicon via copper film chemical mechanical polishing slurry is 6-8.

6. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 1, wherein, The through-silicon via copper film chemical mechanical polishing slurry further includes a butterfly depression inhibitor, which is selected from compounds having the structure of Formula 2 and / or Formula 3; wherein R4 and R5 are each independently C6 to C12 straight-chain or branched alkyl groups, and M is Na, K or NH4.

7. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 6, wherein, The butterfly-shaped depression inhibitor having the structure of Formula 2 includes: potassium 7-tetradecyl sulfate, potassium 8-pentadecanyl sulfate, potassium 7-pentadecanyl sulfate, potassium 8-hexadecyl sulfate, potassium 7-hexadecyl sulfate, potassium 9-heptadecyl sulfate, potassium 8-heptadecyl sulfate, potassium 7-heptadecyl sulfate, potassium 9-octadecyl sulfate, potassium 8-octadecyl sulfate, potassium 7-octadecyl sulfate, potassium 10-nonadecanyl sulfate, potassium 9-nonadecanyl sulfate, potassium 8-nonadecanyl sulfate, potassium 7-nonadecanyl sulfate, potassium 10-eicosyl sulfate, potassium 9-eicosyl sulfate, potassium 8-eicosyl sulfate, potassium 11-tetradecyl sulfate, and 1 0-Potassium icosyl sulfate, 9-Potassium icosyl sulfate, 11-Potassium icosyl sulfate, 10-Potassium icosyl sulfate, 12-Potassium icosyl sulfate, 11-Potassium icosyl sulfate, 12-Potassium icosyl sulfate, 7-Potassium tetradecyl sulfate, 8-Potassium pentadecyl sulfate, 7-Potassium pentadecyl sulfate, 8-Potassium hexadecyl sulfate, 7-Potassium hexadecyl sulfate, 9-Potassium heptadecyl sulfate, 8-Potassium heptadecyl sulfate, 7-Potassium heptadecyl sulfate, 9-Potassium octadecyl sulfate, 8-Potassium octadecyl sulfate, 7-Potassium octadecyl sulfate, 10-Potassium nonadecanyl sulfate, 9-Potassium nonadecanyl sulfate, 8- Nonadecanium sulfate, 7-nonadecanium sulfate, 10-eicosyl sulfate, 9-eicosyl sulfate, 8-eicosyl sulfate, 11-tetraalkyl sulfate, 10-tetraalkyl sulfate, 9-tetraalkyl sulfate, 11-tetraalkyl sulfate, 10-tetraalkyl sulfate, 12-trialkyl sulfate, 11-trialkyl sulfate, 12-tetraalkyl sulfate, 7-tetraalkyl sulfate, 7-tetraalkyl sulfate, 8-pentadecanium sulfate, 7-pentadecanium sulfate, 8-hexadecyl sulfate, 7-hexadecyl sulfate, 9-heptadecyl sulfate, 8-heptadecyl sulfate, 7 - Sodium heptadecanyl sulfate, sodium 9-octadecyl sulfate, sodium 8-octadecyl sulfate, sodium 7-octadecyl sulfate, sodium 10-nonadecanyl sulfate, sodium 9-nonadecanyl sulfate, sodium 8-nonadecanyl sulfate, sodium 7-nonadecanyl sulfate, sodium 10-eicosyl sulfate, sodium 9-eicosyl sulfate, sodium 8-eicosyl sulfate, sodium 11-tetradecyl sulfate, sodium 10-tetradecyl sulfate, sodium 9-tetradecyl sulfate, sodium 11-tetradecyl sulfate, sodium 10-tetradecyl sulfate, sodium 12-trialkyl sulfate, sodium 11-tetradecyl sulfate, and sodium 12-tetradecyl sulfate;The butterfly-shaped depression inhibitor having a structure of Formula 3 includes: potassium 2-hexyl-1-nonyl sulfate, potassium 2-heptyl-1-nonyl sulfate, potassium 2-hexyl-1-decyl sulfate, potassium 2-heptyl-1-decyl sulfate, potassium 2-octyl-1-decyl sulfate, potassium 2-hexyl-1-undecyl sulfate, potassium 2-heptyl-1-undecyl sulfate, potassium 2-octyl-1-undecyl sulfate, potassium 2-hexyl-1-dodecyl sulfate, potassium 2-heptyl-1-dodecyl sulfate, ammonium 2-hexyl-1-nonyl sulfate, ammonium 2-heptyl-1-nonyl sulfate, ammonium 2-hexyl-1-decyl sulfate, ammonium 2-heptyl-1-decyl sulfate, ammonium 2-octyl-1-decyl sulfate. One or more of the following: 2-hexyl-1-undecyl ammonium sulfate, 2-heptyl-1-undecyl ammonium sulfate, 2-octyl-1-undecyl ammonium sulfate, 2-hexyl-1-dodecyl ammonium sulfate, 2-heptyl-1-dodecyl ammonium sulfate, sodium 2-hexyl-1-nonyl sulfate, sodium 2-heptyl-1-nonyl sulfate, sodium 2-hexyl-1-decyl sulfate, sodium 2-heptyl-1-decyl sulfate, sodium 2-octyl-1-undecyl sulfate, sodium 2-hexyl-1-undecyl sulfate, sodium 2-hexyl-1-dodecyl sulfate, and sodium 2-heptyl-1-dodecyl sulfate.

8. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 6, wherein, The mass percentage of the butterfly-shaped depression inhibitor in the polishing fluid is 0.001~1%.

9. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 1, wherein, The through-silicon via copper film chemical mechanical polishing solution further includes one or more of a pH adjuster, a surfactant, and a bactericide.

10. The chemical mechanical polishing slurry for silicon through-hole copper films as described in claim 1, wherein, The abrasive in the through-hole copper film chemical mechanical polishing slurry is 0.02-2% by mass; and / or the oxidant in the through-hole copper film chemical mechanical polishing slurry is 0.1-10% by mass; and / or the chelating agent in the through-hole copper film chemical mechanical polishing slurry is 0.1-15% by mass; and / or the corrosion inhibitor in the through-hole copper film chemical mechanical polishing slurry is 0.005-1% by mass.

11. Use of a chemical mechanical polishing slurry for silicon via copper films as described in any one of claims 1 to 10 on a semiconductor substrate on the surface of copper plating, copper wiring, or silicon via copper, comprising: A silicon through-hole copper film chemical mechanical polishing slurry is brought into contact with a semiconductor substrate to be polished and subjected to chemical mechanical polishing treatment; wherein the surface of the semiconductor substrate to be polished includes at least one copper surface or at least a portion of a copper-containing surface.

12. As described in claim 11, wherein, The semiconductor substrate to be polished further includes a barrier layer and / or a dielectric layer, wherein the barrier layer includes one or more of Ta, TaN, Ti, TiN and SiN; and the dielectric layer includes one or more of TEOS, low-k materials and ultra-low-k materials.