Method and apparatus for rejuvenating polishing slurry
First Claim
1. A method for rejuvenating a polishing slurry to be applied to a chemical-mechanical polishing apparatus for performing chemical-mechanical polishing of wafer, and to be applied to a rejuvenating apparatus, which recovers waste generated by the chemical-mechanical polishing apparatus, rejuvenates polishing slurry, and supplies the rejuvenated polishing slurry to the chemical-mechanical polishing apparatus, the method comprising the steps of:
- a) separating a high-concentration waste, which contains contaminants at high concentrations discharged from the chemical-mechanical polishing apparatus during polishing, from a low-concentration waste, which contains contaminants at low concentrations discharged from the chemical-mechanical polishing apparatus during rinsing, b) neutralizing the low-concentration waste by a neutralizing agent, thereafter rinsing the rejuvenating apparatus using the neutralized low-concentration waste, c) recovering the polishing slurry from the high-concentration waste;
d) re-dispersing abrasive grains contained in the polishing slurry recovered; and
e) mixing the re-dispersed high-concentration waste with fresh polishing slurry, thereafter supplying to the chemical-mechanical polishing apparatus.
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Accused Products
Abstract
A method for rejuvenating a polishing slurry that has been used for a chemical-mechanical polishing process includes the steps of: recovering the polishing slurry; and re-dispersing abrasive grains contained in the polishing slurry recovered. Specifically, the abrasive grains may be re-dispersed by adding a dispersant or applying an electromagnetic field or ultrasonic radiation to the polishing slurry recovered.
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Citations
17 Claims
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1. A method for rejuvenating a polishing slurry to be applied to a chemical-mechanical polishing apparatus for performing chemical-mechanical polishing of wafer, and to be applied to a rejuvenating apparatus, which recovers waste generated by the chemical-mechanical polishing apparatus, rejuvenates polishing slurry, and supplies the rejuvenated polishing slurry to the chemical-mechanical polishing apparatus, the method comprising the steps of:
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a) separating a high-concentration waste, which contains contaminants at high concentrations discharged from the chemical-mechanical polishing apparatus during polishing, from a low-concentration waste, which contains contaminants at low concentrations discharged from the chemical-mechanical polishing apparatus during rinsing, b) neutralizing the low-concentration waste by a neutralizing agent, thereafter rinsing the rejuvenating apparatus using the neutralized low-concentration waste, c) recovering the polishing slurry from the high-concentration waste;
d) re-dispersing abrasive grains contained in the polishing slurry recovered; and
e) mixing the re-dispersed high-concentration waste with fresh polishing slurry, thereafter supplying to the chemical-mechanical polishing apparatus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
c) filtering out fine particles in sizes equal to or smaller than a predetermined lower limit from the polishing slurry recovered;
d) filtering out large particles in sizes equal to or greater than a predetermined upper limit from the polishing slurry recovered; and
e) controlling a hydrogen ion exponent (pH) of the polishing slurry recovered, wherein all of the steps c), d) and e) are performed after the step a) has been carried out.
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8. The method of claim 7, wherein the step b) is performed before the step c) is carried out.
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9. An apparatus for rejuvenating a polishing slurry that recovers waste generated by the chemical-mechanical polishing apparatus for performing chemical-mechanical polishing of wafer, rejuvenates polishing slurry, and supplies the rejuvenated polishing slurry to the chemical-mechanical polishing apparatus, the apparatus comprising:
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means for separating a high-concentration waste, which contains contaminants at high concentrations discharged from the chemical-mechanical polishing apparatus during polishing, from a low-concentration waste, which contains contaminants at low concentrations discharged from the chemical-mechanical polishing apparatus during rinsing, means for neutralizing the low-concentration waste by neutralizing agent, thereafter rinsing the rejuvenating apparatus using the neutralized low-concentration waste, means for recovering the polishing slurry from the high-concentration waste;
means for re-dispersing abrasive grains contained in the polishing slurry recovered; and
means for mixing the re-dispersed high-concentration waste with fresh polishing slurry, thereafter supplying to the chemical-mechanical polishing apparatus. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
means for filtering out fine particles in sizes equal to or smaller than a predetermined lower limit from the polishing slurry recovered;
means for filtering out large particles in sizes equal to or greater than a predetermined upper limit from the polishing slurry recovered; and
means for controlling a hydrogen ion exponent (pH) of the polishing slurry recovered.
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16. The apparatus of claim 15, wherein the large particle filtering means comprises a filter with a pore diameter between 100 μ
- m and 200 μ
m, both inclusive.
- m and 200 μ
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17. The apparatus of claim 15, wherein the abrasive grains are dispersed again by the re-dispersing means before the fine particles are removed by the fine particle filtering means.
Specification