Methods and compositions for processing dielectric substrate

1. A method of polishing a dielectric-containing surface of a substrate, the method comprising:

providing a substrate comprising a surface that includes a pattern dielectric material comprising raised areas of the dielectric material and trench areas of the dielectric material, a difference between a height of the raised areas and a height of the trench areas being step height, wherein an initial step height of the substrate is at least 1000 angstroms,

providing a polishing pad,

providing a chemical-mechanical polishing composition comprising:

an aqueous medium,

abrasive particles dispersed in the aqueous medium, and

hydroxamic acid or substituted hydroxamic acid of the formula:

wherein R is selected from the group consisting of: hydrogen, alkyl, cycloalkyl, aryl, heterocyclic alkyl, and heterocyclic aryl, any of which may be substituted,

the slurry having a pH of below about 7,

contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and

moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the silicon oxide layer on a surface of the substrate to polish the substrate, wherein a planarization efficiency for the polished substrate is at least 2.0.

2. The method of claim 1 wherein R is 2-hydroxyphenyl, a C 1 to C 5 branched or straight chain alkyl-substituted phenyl, or a C 1 to C 5 branched or straight chain alkyl (e.g., saturated) group.

3. The method of claim 1 wherein the hydroxamic acid or substituted hydroxamic acid is salicylhydroxamic acid:

4. The method of claim 1 wherein the hydroxamic acid or substituted hydroxamic acid is present in the polishing composition at a concentration of about 5 to about 3,000 parts per million.

5. The method of claim 1 wherein the pattern dielectric consists of dielectric material selected from silicon oxide, tetraethoxysilane, phosphosilicate glass, or borophosphosilicate glass.