Highly dilutable polishing concentrates and slurries
The present disclosure provides a concentrate for use in chemical mechanical polishing slurries, and a method of diluting that concentrate to a point of use slurry. The concentrate comprises abrasive, complexing agent, and corrosion inhibitor, and the concentrate is diluted with water and oxidizer. These components are present in amounts such that the concentrate can be diluted at very high dilution ratios, without affecting the polishing performance.
1. A chemical mechanical polishing slurry, comprising:
a) a concentrate, comprising:
about 0.5 wt % to about 10 wt %, based on the total weight of said concentrate, of an abrasive;
about 1 wt % to about 20 wt %, based on the total weight of said concentrate, of a complexing agent; and
a corrosion inhibitor;
b) water; and
c) an oxidizer,
wherein said water and said oxidizer are present in the slurry in an amount governed by the formula:
0. 8≦[oxidizer]/ f≦ 2.0,
wherein f=A+B*[complexing agent] c ,
wherein A is between 0.35 and 0.8, B is between 0.3 and 0.5, and C is about 1, and
[oxidizer] and [complexing agent] are the amounts of the oxidizer and complexing agent in the slurry, respectively.
2. The slurry of claim 1 , wherein said abrasive is selected from the group consisting of alumina, fumed silica, colloidal silica, coated particles, titania, ceria, zirconia, and any combinations thereof.
3. The slurry of claim 1 , wherein said complexing agent is selected from the group consisting of organic acids and their salts, amino acetic acids, amino acids, glycine, alanine, carboxylic acids, polyamines, ammonia based compounds, quaternary ammonium compounds, inorganic acids, compounds with both carboxylic and amino functions, ethylenediaminetetraacetic acid, diethylene triamine pentaacetic acid, and any mixtures thereof.
4. The slurry of claim 1 , wherein corrosion inhibitor is selected from the group consisting of benzotriazole and its derivatives, tolyl triazole and its derivatives, and azoles.
5. The slurry of claim 1 , wherein the concentrate is highly dilutable.
6. The slurry of claim 5 , wherein the concentrate is diluted to a level of at least 10×, to form the slurry.
7. The slurry of claim 5 , wherein the slurry is used to remove a copper layer from a substrate, and the chemical mechanical polishing slurry removes said copper layer at a rate that is at least 75% of a peak removal rate of the chemical mechanical polishing slurry.
8. The slurry of claim 1 , wherein said oxidizer is present in an amount of about 0.1 wt % to about 5 wt %, based on the total weight of the slurry.
9. The slurry of claim 1 , wherein said oxidizer is present in an amount of about 0.4 wt % to about 2 wt %, based on the total weight of the slurry.
10. The slurry of claim 5 , wherein the concentrate is diluted to a level of at least 20×, to form the slurry.
11. The slurry of claim 1 , wherein said corrosion inhibitor is present in an amount of about 0.001 wt % to about 1 wt %, based on the total weight of said concentrate.