Acid polishing composition and method of polishing a substrate having enhanced defect inhibition
An acid chemical mechanical polishing composition includes colloidal silica abrasive particles having a positive zeta potential, and select alkoxysilane succinic acid anhydride compounds to enhance the reduction of defects on dielectric materials of substrates such as silicon dioxide and silicon nitride. Also disclosed are methods for polishing a substrate with the acid chemical mechanical polishing composition to remove some of the dielectric materials such as silicon dioxide and silicon nitride.
1. An acid chemical mechanical polishing composition, consisting of, as initial components:
water;
colloidal silica abrasive particles having a positive zeta potential;
an alkoxysilane succinic acid anhydride in amounts of 0.0001 to 0.1 wt % having formula (I):
wherein R 1 is selected from (C 1 -C 4 )alkyl when n is 1 or 2; R 2 is methoxy, ethoxy, or methoxyethyleneoxy; and n can be 0, 1 or 2;
a pH<7;
optionally a pH adjusting agent;
optionally a quaternary ammonium compound; and
optionally a biocide.
2. The acid chemical mechanical polishing composition of claim 1 , wherein the chemical mechanical polishing composition consists of, as initial components:
the water;
the colloidal silica abrasive having a positive zeta potential in amounts of 0.1 to 40 wt %;
the alkoxysilane succinic acid anhydride of formula (I) in amounts of 0.00075 to 0.006 wt %;
the pH of 2 to 6.5;
optionally the pH adjusting agent;
optionally the quaternary ammonium compound; and
optionally the biocide.
3. The acid chemical mechanical polishing composition of claim 1 , wherein the alkoxysilane succinic acid anhydride having formula (I) are selected from the group consisting of 3-trimethoxysilylpropyl succinic acid anhydride; 3-methyldimethoxysilylpropyl succinic acid anhydride; 3-dimethylmethoxysilylpropyl succinic acid anhydride; 3-triethoxysilylpropyl succinic acid anhydride; 3-methyldiethoxysilylpropyl succinic acid anhydride; 3-dimethylethoxysilylpropyl succinic acid anhydride; 3-tris-(methoxyethylenoxy)-silylpropyl succinic acid anhydride; 3-methylbis-(methoxyethylenoxy)-silylpropyl succinic acid anhydride; and 3-dimethylmethoxyethylenoxysilylpropyl succinic acid anhydride.
4. The acid chemical mechanical polishing composition of claim 1 , wherein the colloidal silica abrasive particles having the positive zeta potential comprise a nitrogen containing compound.
5. The acid chemical mechanical polishing composition of claim 4 , wherein the nitrogen containing compound is an aminosilane compound.
6. A method for chemical mechanical polishing of a substrate, comprising:
providing a substrate, wherein the substrate comprises dielectric materials of silicon oxide, silicon nitride or combinations thereof;
providing an acid chemical mechanical polishing composition, consisting of, as initial components:
water;
colloidal silica abrasive particles having a positive zeta potential;
an alkoxysilane succinic acid anhydride in amounts of 0.0001 to 0.1 wt % having formula (I):
wherein R 1 is selected from (C 1 -C 4 )alkyl when n is 1 or 2; R 2 is methoxy, ethoxy, or methoxyethyleneoxy; and n can be 0, 1 or 2;
a pH<7;
optionally a pH adjusting agent;
optionally a quaternary ammonium compound; and
optionally a biocide;
providing a chemical mechanical polishing pad with a polishing surface;
creating dynamic contact at an interface between the polishing surface of the acid chemical mechanical polishing pad and the substrate with a down force of 0.69 to 34.5 kPa; and
dispensing the acid chemical mechanical polishing composition onto the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate;
wherein the substrate is polished; and, wherein at least some of the silicon oxide, silicon nitride or combinations thereof is removed from the substrate.
7. The method of claim 6 , wherein polishing is done at a platen speed of 93-113 revolutions per minute, a carrier speed of 87-111 revolutions per minute, an acid chemical mechanical polishing composition flow rate of 125-300 mL/min, a nominal down force of 21.4 kPa on a 200 mm polishing machine; and, wherein the chemical mechanical polishing pad comprises a polyurethane polishing layer containing polymeric hollow core microparticles and a polyurethane impregnated non-woven subpad.
8. The method of claim 6 , wherein the acid chemical mechanical polishing composition provided consists of, as initial components:
water;
a colloidal silica abrasive particles having a positive zeta potential in amounts of 0.1 to 40 wt %;
the alkoxysilane succinic acid anhydride of formula (I) in amounts of 0.00075 to 0.006 wt %;
a pH of 2 to 6.5;
optionally the pH adjusting agent;
optionally the quaternary ammonium compound; and
optionally the biocide.
9. The method of claim 6 , wherein the alkoxysilane succinic acid anhydride having formula (I) are selected from the group consisting of 3-trimethoxysilylpropyl succinic acid anhydride; 3-methyldimethoxysilylpropyl succinic acid anhydride; 3-dimethylmethoxysilylpropyl succinic acid anhydride; 3-triethoxysilylpropyl succinic acid anhydride; 3-methyldiethoxysilylpropyl succinic acid anhydride; 3-dimethylethoxysilylpropyl succinic acid anhydride; 3-tris-(methoxyethylenoxy)-silylpropyl succinic acid anhydride; 3-methylbis-(methoxyethylenoxy)-silylpropyl succinic acid anhydride; and 3-dimethylmethoxyethylenoxysilylpropyl succinic acid anhydride.
10. The method of claim 6 , wherein the colloidal silica abrasive particles having the positive zeta potential comprise a nitrogen containing compound.