Slurry composition and method of substrate polishing
View Patent ↗Slurry composition and a method of substrate polishing used in chemical mechanical polishing (CMP). The present invention concerns a slurry composition containing a polishing agent and a water soluble polymer. The slurry composition contains a water soluble polymer that has a solubility parameter in the range of 9.0 to 14.0 and that may contain hetero atoms at a level sufficient to lower the polishing rate near the edges of the polished substrate defined as the region within 1 mm of the outer edge of the polished substrate to a level below the mean polishing rate of the polished substrate. The water soluble polymer may have a mean molecular weight in the range of 200 to about 3,000,000, and the mean molecular weight may be in the range of 200 to 110,000 if hetero atoms are present in the main-chain structure and the SP value is under 9.5.
1. A chemical-mechanical polishing composition comprising a polishing agent, and a water soluble polymer having a mean molecular weight of about 200 to about 3,000,000 that has a solubility parameter (SP) in the range of 9.0 to 14.0, wherein the water soluble polymer has one or more hetero atoms.
2. The composition of claim 1 in which the mean molecular weight of the water soluble polymer is about 200 to 110,000.
3. The composition of claim 1 in which the water soluble polymer is present at about 1 ppm to about 1,000 ppm.
4. The composition of claim 1 in which the water soluble polymer is present at about 1 ppm to about 600 ppm.
5. The composition of claim 1 in which the water soluble polymer is present at about 1 ppm to about 400 ppm.
6. The composition of claim 1 in which the water soluble polymer is present at about 1 ppm to about 200 ppm.
7. The composition of claim 1 in which the amount of the water soluble polymer is not more than 200 ppm and the water soluble polymer has a solubility parameter in a range of 12 to 13.9.
8. The composition of claim 1 in which the water soluble polymer comprises a polyoxyalkylene oxide (such as PEG, PEO, PPG, PPO), poly-N-vinylpyrrolidone, poly-N-vinyl acetamide, poly-N-methylvinyl acetamide poly-2-ethyloxazoline, or a mixture thereof.
9. The composition of claim 1 wherein the pH of the composition is from about 7 to about 12.
10. A method of polishing a substrate, comprising: contacting, or adhering to, the substrate a composition comprising a polishing agent, and a water soluble polymer having a mean molecular weight of about 200 to about 3,000,000 that has a solubility parameter (SP) in the range of 9.0 to 14.0, wherein the water soluble polymer has one or more hetero atoms.
11. The method of claim 10 in which the water soluble polymer is present at a level of 1 ppm to 1000 ppm.
12. The method of claim 10 in which the mean molecular weight of the water soluble polymer is in the range of 200 to 110,000 and the SP value is under 9.5.
13. The method of claim 10 wherein the substrate comprises a silicon substrate such as a polysilicon film or silicon wafer.