Polishing slurry and method of reclaiming wafers
AssigneesKabushiki Kaisha Kobe Seiko Sho, Kobe Precision Inc.
InventorsTetsuo Suzuki, Satoru Takada
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Abstract
The polishing slurry contains monoclinic zirconium oxide particles having a crystallite size of 10 to 1,000 nm and an average particle diameter of 30 to 2,000 nm in an amount of 1 to 20 weight %, a carboxylic acid having three or more carboxyl groups in the molecule, and a quaternary alkylammonium hydroxide, and has a pH of 9 to 12. The method of reclaiming wafers comprises a step of polishing used test wafers by using the polishing slurry above and removing the films formed on the wafers and the degenerated layers formed on the wafer surfaces, a step of mirror-polishing at least one side of the wafers, and a step of cleaning the wafers.
Claims20
A polishing slurry having a pH of 9 to 12 and being essentially free from an organic amine, comprising:
- monoclinic zirconium oxide particles having a crystallite size of 10 to 1,000 nm and an average particle diameter of 30 to 2,000 nm in an amount of 1 to 20 weight %;
- at least one carboxylic acid having four or more carboxyl groups in the molecule;
- and
- at least one quaternary alkylammonium hydroxide.
Dependencies are inferred from the claim text.