Composition and method for polishing memory hard disks exhibiting reduced edge roll off

1. A chemical-mechanical polishing composition comprising:

(a) an abrasive comprising colloidal silica and fused silica,

(b) about 10 ppm to about 1000 ppm of a compound of formula (I):

wherein R is selected from

a straight chain or branched chain C 1 -C 20 alkyl,

R 5 C 6 H 4 , and

R 6 —O—(R 7 O) n —,

wherein R 1 -R 5 are independently selected from straight chain or branched chain C 1 -C 20 alkyls,

wherein R 6 is a straight chain or branched chain C 1 -C 20 alkyl or R 8 —C 6 H 4 —,

wherein R 7 is a straight chain or branched chain C 2 -C 10 alkylene,

wherein R 8 is a straight chain or branched chain C 1 -C 20 alkyl,

wherein n is an integer of from 1 to about 20,

wherein X and Y are independently O or a covalent bond, and

wherein A and B are independently an alkali metal cation or an organic amine compound,

(c) an amino acid,

(d) hydrogen peroxide, and

(e) water,

wherein the polishing composition has a pH of about 1 to about 5.

2. The polishing composition of claim 1 , wherein the colloidal silica has an average particle size of about 10 nm to about 200 nm.

3. The polishing composition of claim 1 , wherein the fused silica has an average particle size of about 100 nm to about 800 nm.

4. The polishing composition of claim 1 , wherein the compound of formula (I) is selected from sodium dodecyl sulfate, diethylhexyl sulfosuccinate, dodecylbenzene sulfonate, a sec-alkyl derivative of benzenesulfonic acid, an alkyl diphenyloxide disulfonate, secondary alkane sulfonate, mono alkyl branched propoxy sulfate, polyethyleneglycol nonylphenyl ether sulfate and combinations thereof.

5. The polishing composition of claim 1 , wherein the amino acid is glycine or alanine.

6. The polishing composition of claim 1 , wherein the polishing composition comprises about 100 ppm to about 500 ppm of the compound of formula (I).

7. The polishing composition of claim 1 , wherein the polishing composition comprises about 0.1 wt. % to about 10 wt. % of a combination of colloidal silica and fused silica.

8. A method of chemically mechanically polishing a substrate comprising:

(i) providing a substrate,

(ii) providing a polishing pad,

(iii) providing the chemical-mechanical polishing composition of claim 1 ,

(iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition, and

(v) moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to abrade at least a portion of a surface of the substrate to thereby polish the substrate.

9. The method of claim 8 , wherein the substrate is a nickel-phosphorous-coated aluminum memory disk, wherein the substrate comprises nickel-phosphorous on a surface of the substrate, and wherein at least a portion of the nickel-phosphorous on a surface of the substrate is abraded to polish the substrate.