Chemical mechanical polishing slurry compositions and method using the same for copper and through-silicon via applications
View Patent ↗Provided are novel chemical mechanical polishing (CMP) slurry compositions for polishing copper substrates and method of using the CMP compositions. The CMP slurry compositions deliver superior planarization with high and tunable removal rates and low defects when polishing bulk copper layers of the nanostructures of IC chips. The CMP slurry compositions also offer the high selectivity for polishing copper relative to the other materials (such as Ti, TiN, Ta, TaN, and Si), suitable for through-silicon via (TSV) CMP process which demands high copper film removal rates.
1. A chemical mechanical polishing (CMP) slurry composition for removing copper comprises:
a. from 0.0 wt % to 25 wt % abrasive;
b. from 0.01 wt % to 22 wt % chelating agent;
c. from 0.001 wt % to 0.15 wt % corrosion inhibitor;
d. from 0.0001 wt % to 0.50 wt % choline salt;
e. from 0.0001 wt % to 0.20 wt % organic amine;
f. from 0.01 wt % to 10 wt % oxidizer;
g. from 0.0001 wt % to 0.05 wt % biocide;
h. remaining is substantially liquid carrier;
wherein the polishing slurry composition has pH from 5.0 to 8.0; and
the choline salt having a general molecular structure shown below:
wherein anion Y − is selected from the group consisting of bicarbonate, p-toluenesulfonate, bitartrate, and combinations thereof.
2. The CMP slurry composition of claim 1 , wherein the abrasive is selected from the group consisting of colloidal silica particles, alumina doped silica particles, colloidal aluminum oxide, colloidal and photoactive titanium dioxide, cerium oxide, colloidal cerium oxide, nano-sized diamond particles, nano-sized silicon nitride particles, mono-modal, bi-modal, multi-modal colloidal abrasive particles, zirconium oxide, organic polymer-based soft abrasives, surface-coated or modified abrasives, and mixtures thereof; the abrasive having narrow or broad particle size distributions, with various sizes and different shapes selected from the group consisting of spherical shape, cocoon shape, aggregate shape and combinations thereof; the chelating agent is selected from the group consisting of glycine, amino acids, and amino acid derivatives; the corrosion inhibitor is selected from the group consisting of triazole and its derivatives, benzene triazole and its derivatives; the organic amine compound agent is selected from the group consisting of ethylene diamine, propylene diamine, organic amine compounds containing multi amino groups in the same molecular framework; the oxidizer is selected from the group consisting of periodic acid, hydrogen peroxide, potassium iodate, potassium permanganate, ammonium persulfate, ammonium molybdate, ferric nitrate, nitric acid, potassium nitrate, and mixtures thereof; and the liquid carrier is water.
3. The CMP slurry composition of claim 2 , the triazole derivative is selected from the group consisting of amino-substituted triazole compounds, bi-amino-substituted triazole compounds, and mixtures thereof.
4. The CMP slurry composition of claim 1 , further comprising one selected from the group consisting of from 0.01 wt % to 0.5 wt % pH adjusting agent comprising inorganic or organic acids; from 0.00 wt % to 1.0 wt % surfactant; and combinations thereof; wherein:
the pH adjusting agent is selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, and mixtures thereof; and the surfactant is nonionic, anionic, cationic or amphoteric surfactant.
5. The CMP slurry composition of claim 1 has polishing selectivity of Cu:Ta, Cu:TaN, Cu:Ti Cu:TiN and Cu:Si ranging from about 200 to about 5000.
6. The CMP slurry composition 1, comprising nano-sized colloidal silica particles prepared from TMOS or TEOS; glycine; ethylenediamine, 3-amino-1,2,4-triazole, hydrogen peroxide; and choline bicarbonate; and the pH is 6.5 to 7.5.