Method of polishing a substrate comprising polysilicon and at least one of silicon oxide and silicon nitride
View Patent ↗A method for chemical mechanical polishing of a substrate is provided, comprising: providing a substrate, wherein the substrate comprises polysilicon and at least one of silicon oxide and silicon nitride; providing a chemical mechanical polishing composition, comprising, as initial components: water; an abrasive; and an alkyl aryl polyether sulfonate compound, wherein the alkyl aryl polyether sulfonate compound has a hydrophobic portion having an alkyl group bound to an aryl ring and a nonionic acyclic hydrophilic portion having 4 to 100 carbon atoms; providing a chemical mechanical polishing pad with a polishing surface; moving the polishing surface relative to the substrate; dispensing the chemical mechanical polishing composition onto the polishing surface; and, abrading at least a portion of the substrate to polish the substrate; wherein at least some of the polysilicon is removed from the substrate; and, wherein at least some of the at least one of silicon oxide and silicon nitride is removed from the substrate.
1. A method for chemical mechanical polishing of a substrate, comprising:
providing a substrate, wherein the substrate comprises polysilicon and at least one of silicon oxide and silicon nitride;
providing a chemical mechanical polishing composition, consisting of, as initial components: water; an abrasive; an alkyl aryl polyether sulfonate compound, wherein the alkyl aryl polyether sulfonate compound has a formula
wherein R is a branched C 6-10 alkyl group; n is 2 to 8; and, M is selected from the group consisting of H, Na, K, L 1 and NH 4 ; and, optionally, a pH adjusting agent, wherein the pH adjusting agent is an inorganic acid;
providing a chemical mechanical polishing pad with a polishing surface;
moving the polishing surface relative to the substrate;
dispensing the chemical mechanical polishing composition onto the polishing surface; and,
abrading at least a portion of the substrate to polish the substrate;
wherein at least some of the polysilicon is removed from the substrate; wherein at least some of the at least one of silicon oxide and silicon nitride is removed from the substrate; and, wherein the alkyl aryl polyether sulfonate compound suppresses the removal rate of polysilicon.
2. The method of claim 1 , wherein the substrate comprises polysilicon in the presence of silicon oxide and wherein the chemical mechanical polishing composition exhibits a silicon oxide to polysilicon removal rate selectivity of >5:1.
3. The method of claim 2 , wherein the chemical mechanical polishing composition exhibits a silicon oxide removal rate of >500 Å/min with a platen speed of 93 revolutions per minute, a carrier speed of 87 revolutions per minute, a chemical mechanical polishing composition flow rate of 200 ml/min, a nominal down force of 3 psi 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.
4. The method of claim 3 , wherein the polysilicon is amorphous polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon oxide to amorphous polysilicon removal rate selectivity of >5:1.
5. The method of claim 3 , wherein the polysilicon is crystalline polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon oxide to crystalline polysilicon removal rate selectivity of >10:1.
6. The method of claim 1 , wherein the substrate comprises polysilicon in the presence of silicon nitride and wherein the chemical mechanical polishing composition exhibits a silicon nitride to polysilicon removal rate selectivity of >5:1.
7. The method of claim 6 , wherein the chemical mechanical polishing composition exhibits a silicon nitride removal rate of >500 Å/min with a platen speed of 93 revolutions per minute, a carrier speed of 87 revolutions per minute, a chemical mechanical polishing composition flow rate of 200 ml/min, a nominal down force of 3 psi 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 7 , wherein the polysilicon is amorphous polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon nitride to amorphous polysilicon removal rate selectivity of >5:1.
9. The method of claim 7 , wherein the polysilicon is crystalline polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon nitride to crystalline polysilicon removal rate selectivity of ≧10:1.
10. The method of claim 1 , wherein the chemical mechanical polishing composition consists of as initial components: water; 0.1 to 40 wt % of the abrasive, wherein the abrasive is a colloidal silica abrasive; 0.01 to 1 wt % of the alkyl aryl polyether sulfonate compound; and, optionally, the pH adjusting agent.
11. The method of claim 10 , wherein the substrate comprises polysilicon in the presence of silicon oxide and wherein the chemical mechanical polishing composition exhibits a silicon oxide to polysilicon removal rate selectivity of >5:1.
12. The method of claim 11 , wherein the chemical mechanical polishing composition exhibits a silicon oxide removal rate of 500 Å/min with a platen speed of 93 revolutions per minute, a carrier speed of 87 revolutions per minute, a chemical mechanical polishing composition flow rate of 200 ml/min, a nominal down force of 3 psi 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.
13. The method of claim 12 , wherein the polysilicon is amorphous polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon oxide to amorphous polysilicon removal rate selectivity of >5:1.
14. The method of claim 12 , wherein the polysilicon is crystalline polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon oxide to crystalline polysilicon removal rate selectivity of >10:1.
15. The method of claim 10 , wherein the substrate comprises polysilicon in the presence of silicon nitride and wherein the chemical mechanical polishing composition exhibits a silicon nitride to polysilicon removal rate selectivity of >5:1.
16. The method of claim 15 , wherein the chemical mechanical polishing composition exhibits a silicon nitride removal rate of >500 Å/min with a platen speed of 93 revolutions per minute, a carrier speed of 87 revolutions per minute, a chemical mechanical polishing composition flow rate of 200 ml/min, a nominal down force of 3 psi 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.
17. The method of claim 16 , wherein the polysilicon is amorphous polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon nitride to amorphous polysilicon removal rate selectivity of >5:1.
18. The method of claim 16 , wherein the polysilicon is crystalline polysilicon and wherein the chemical mechanical polishing composition exhibits a silicon nitride to crystalline polysilicon removal rate selectivity of ≧10:1.