Polishing composition and method for producing same

Patent metadata

Field	Value
Publication number	US-11976220-B2
Application number	US-202217870663-A
Country	US
Kind code	B2
Filing date	Jul 21, 2022
Priority date	Nov 6, 2017
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

Provided is a polishing composition which contains a water-soluble polymer and is suitable for reducing LPDs. The polishing composition provided in this application includes an abrasive, a water-soluble polymer, and a basic compound. In the polishing composition, the content of a reaction product of a polymerization initiator and a polymerization inhibitor is 0.1 ppb or less of the polishing composition on a weight basis.

First claim

The invention claimed is:

1. A polishing composition comprising:
an abrasive;
a water-soluble polymer;
a basic compound; and
a reaction product of a polymerization initiator and a polymerization inhibitor, wherein:
the polymerization initiator is a radical polymerization initiator, wherein the radical polymerization initiator is one or two or more selected from the group consisting of persulfates, water-soluble peroxides, oil-soluble peroxides, water-soluble azo compounds, and oil-soluble azo compounds; and
wherein the reaction product of the polymerization initiator and the polymerization inhibitor is a coupling reaction product of the polymerization initiator and the polymerization inhibitor;

wherein a content of the reaction product of the polymerization initiator and the polymerization inhibitor is 0.1 ppb or less of the polishing composition on a weight basis, and
the water-soluble polymer contains 10 mol % or more and 100 mol % or less of a structural unit derived from a monomer containing a nitrogen atom.

2. The polishing composition according to claim 1 , wherein the polymerization inhibitor includes at least one compound selected from the group consisting of a compound represented by the following General Formula (1), a compound represented by the following General Formula (2), a phenothiazine compound, and a nitrosamine compound:

wherein R 1 and R 2 each independently represent a hydrogen atom or a group selected from the group consisting of a hydroxy group, an alkyl group having 1 to 8 carbon atoms and an alkoxy group having 1 to 8 carbon atoms, and R 3 represents a group selected from the group consisting of an alkyl group having 1 to 8 carbon atoms and an alkoxy group having 1 to 8 carbon atoms;

wherein X represents CH 2, CH(CH 2 ) p OH wherein p is an integer of 0 to 3, CHO(CH 2 ) q OH wherein q is an integer of 0 to 3, CHO(CH 2 ) r CH 3 wherein r is an integer of 0 to 2, CHCOOH, or C═O; and R 4 , R 5 , R 6 and R 7 each independently represent a group selected from among alkyl groups having 1 to 3 carbon atoms.

3. The polishing composition according to claim 2 , wherein the content of the reaction product of the polymerization initiator and the polymerization inhibitor is 0.001 ppb or more and 0.1 ppb or less of the polishing composition on a weight basis.

4. The polishing composition according to claim 1 , wherein the amount of the polymerization inhibitor used is 0.005 wt % or more and 0.5 wt % or less with respect to the weight of the water-soluble polymer.

5. The polishing composition according to claim 1 , wherein the polymerization inhibitor includes at least one compound selected from the group consisting of a compound represented by the following General Formula (1), a compound represented by the following General Formula (2), a phenothiazine compound, and a nitrosamine compound:

wherein R 1 to R 3 each independently represent a hydrogen atom or a group selected from the group consisting of a hydroxy group, an alkyl group having 1 to 8 carbon atoms and an alkoxy group having 1 to 8 carbon atoms, and

wherein X represents CH 2, CH(CH 2 ) p OHwherein p is an integer of 0 to 3, CHO(CH 2 ) q OH wherein q is an integer of 0 to 3, CHO(CH 2 ) r CH 3 wherein r is an integer of 0 to 2, CHCOOH, or C═O; and R 4 , R 5 , R 6 and R 7 each independently represent a group selected from among alkyl groups having 1 to 3 carbon atoms.

6. The polishing composition according to claim 5 , wherein the amount of the polymerization inhibitor used is 0.005 wt % or more and 0.5 wt % or less with respect to the weight of the water-soluble polymer.

7. The polishing composition according to claim 5 , wherein the content of the reaction product of the polymerization initiator and the polymerization inhibitor is 0.001 ppb or more and 0.1 ppb or less of the polishing composition on a weight basis.

8. A method of polishing a silicon wafer comprising,
polishing the silicon wafer with a polishing composition of claim 1 .

9. A method for producing the polishing composition according to claim 1 , the method comprising:
preparing a polymer composition containing the water-soluble polymer, wherein the content of the reaction product in the polymer composition is 0.1 ppb or less with respect to the polishing composition on a weight basis; and
mixing the polymer composition, the abrasive, and the basic compound.

10. A polishing composition comprising:
an abrasive;
a water-soluble polymer;
a basic compound; and
a reaction product of a polymerization initiator and a polymerization inhibitor, wherein the reaction product comprises a coupling reaction product of the polymerization initiator and the polymerization inhibitor or a chain reaction product of the polymerization inhibitor;
wherein:
a content of the reaction product of the polymerization initiator and the polymerization inhibitor is 0.1 ppb or less of the polishing composition on a weight basis;
the water-soluble polymer contains 10 mol % or more and 100 mol % or less of a structural unit derived from a monomer containing a nitrogen atom; and
the water-soluble polymer is a morpholine polymer having a structural unit derived from N-(meth)acryloylmorpholine.

11. The polishing composition according to claim 10 , wherein the morpholine polymer has a weight average molecular weight of 200,000 or more.

12. The polishing composition according to claim 1 , wherein the abrasive is colloidal silica having an average secondary particle size of 35 nm or more.

13. The polishing composition according to claim 12 , wherein the abrasive has an average aspect ratio of 1.0 or more and 1.5 or less.

14. A polishing composition comprising:
an abrasive;
a water-soluble polymer;
a basic compound; and
a reaction product of a polymerization initiator and a polymerization inhibitor, wherein the reaction product comprises a coupling reaction product of the polymerization initiator and the polymerization inhibitor or a chain reaction product of the polymerization inhibitor;
wherein:
a content of the reaction product of the polymerization initiator and the polymerization inhibitor is 0.1 ppb or less of the polishing composition on a weight basis;

the water-soluble polymer contains 10 mol % or more and 100 mol % or less of a structural unit derived from a monomer containing a nitrogen atom; and
the reaction product comprises an aromatic ring derived from the polymerization inhibitor or a hydrophobic moiety derived from a heterocyclic amine.

Assignees

• Fujimi Inc

Inventors

• Tsuchiya Kohsuke
• Tansho Hisanori
• Suga Yusuke
• Ichitsubo Taiki
• Takemoto Takayuki
• Saito Naohiko
• Kaai Michihiro

Classifications

• H10P52/402

  of semiconductor materials · CPC title

• H10P90/129

  by polishing · CPC title

• H10P52/00

  Grinding, lapping or polishing of wafers, substrates or parts of devices · CPC title

• C09G1/02 Primary

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• B24B37/044

  characterised by the composition of the lapping agent · CPC title