Composition and method used for chemical mechanical planarization of metals
Compositions for use in CMP processing and methods of CMP processing. The composition utilizes low levels of particulate material, in combination with at least one amino acid, at least one oxidizer, and water to remove a metal layer such as one containing copper to a stop layer with high selectivity.
1 - 21 . (canceled)
22 . A method of removing copper from the surface of a wafer containing copper above a stop layer, comprising: contacting a wafer surface with a polishing pad at an interface between the wafer surface and the polishing pad; supplying a first chemical mechanical polishing slurry to the interface, the first chemical mechanical polishing slurry comprising
hydrogen peroxide,
at least one amino acid selected from the group consisting of aminoacetic acid, serine, lysine, glutamine, L-alanine, DL-alanine, iminoacetic acid, asparagine, aspartic acid, valine, sarcosine, and mixtures thereof,
about 5 ppm to about 700 ppm abrasive particulate material by weight, and
water, wherein the copper to stop layer selectivity is at least 50:1; and initiating relative motion between the polishing pad and the wafer surface to decrease the thickness of the copper until the stop layer is reached, or to decrease the thickness of a copper without reaching the stop layer.
23 - 25 . (canceled)
26 . The method of claim 22 wherein the particulate material has a concentration in the range of about 5 ppm to about 400 ppm by weight.
27 . The method of claim 22 wherein the particulate material has a concentration in the range of about 5 ppm to about 100 ppm by weight.
28 . A method of removing copper from the surface of a wafer containing copper above a stop layer, comprising: contacting a wafer surface with a polishing pad at an interface; adding water and at least one oxidizing agent to a chemical mechanical polishing precursor slurry, the chemical mechanical polishing precursor slurry comprising at least one amino acid, at least one particulate material, and water, the combination of water and chemical mechanical polishing precursor slurry and oxidizing agent forming a diluted solution chemical mechanical polishing slurry having about 5 ppm to about 700 ppm particulate material by weight and 0.25% to about 5% of oxidizing agent by weight; supplying the diluted chemical mechanical polishing slurry to the interface, wherein the particulate material in the diluted solution has a concentration sufficient to remove copper while maintaining a rate of removal of copper to stop layer of at least 50:1; and initiating relative motion of the polishing pad and the wafer surface.
29 - 31 . (canceled)
32 . The method of claim 28 wherein the particulate material has a concentration in the range of 5 ppm to 700 ppm by weight.
33 . The method of claim 28 wherein the particulate material has a concentration in the range of about 5 ppm to about 400 ppm by weight.
34 . The method of claim 28 wherein the particulate material has a concentration in the range of about 5 ppm to about 100 ppm by weight.
35 - 53 . (canceled)
54 . The method of claim 22 wherein the amino acid is aminoacetic acid.
55 . The method of claim 22 wherein the copper to stop layer selectivity is least 100:1.
56 . The method of claim 22 wherein the copper to stop layer selectivity is least 300:1.
57 . The method of claim 22 wherein the first chemical mechanical polishing slurry has a pH of about 6.6.
58 . The method of claim 22 wherein the first chemical mechanical polishing slurry further comprises a corrosion inhibitor.
59 . The method of claim 58 wherein said corrosion inhibitor is 1,2,4 triazole.
60 . The method of claim 22 wherein the amino acid has a concentration in the range of about 0.25% to about 2% by weight.
61 . The method of claim 22 wherein the first chemical mechanical polishing slurry consists of hydrogen peroxide; an amino acid; about 5 ppm to about 700 ppm particulate material by weight; and water.
62 . The method of claim 22 wherein the first chemical mechanical polishing slurry consists of hydrogen peroxide; an amino acid; 5 ppm to 700 ppm particulate material by weight; a corrosion inhibitor, and water.
63 . The method of claim 22 wherein the abrasive particulate material comprises silica.
64 . A method of removing copper from the surface of a wafer containing copper above a stop layer, comprising:
contacting a wafer surface with a polishing pad at an interface between the wafer surface and the polishing pad;
supplying a first chemical mechanical polishing slurry to the interface, the first chemical mechanical polishing slurry comprising:
hydrogen peroxide;
at least one amino acid selected from the group consisting of aminoacetic acid, serine, lysine, glutamine, L-alanine, DL-alanine, iminoacetic acid, asparagine, aspartic acid, valine, sarcosine, and mixtures thereof;
between about 5 ppm to about 700 ppm abrasive particulate material by weight; and
water, wherein the copper to stop layer selectivity is at least 50:1; and
initiating relative motion between the polishing pad and the wafer surface to decrease the thickness of the copper until the stop layer is reached, or to decrease the thickness of a copper without reaching the stop layer, wherein the copper removal rate is between 622 angstroms per minute and 6790 angstroms per minute at a down force of 3 psi.