Unlock instant, AI-driven research and patent intelligence for your innovation.

Cmp Polishing Slurry and Method of Polishing Substrate

a technology of polishing slurry and substrate, which is applied in the direction of lapping machines, manufacturing tools, other chemical processes, etc., can solve the problems of not having practical useable shallow trench isolation properties, reducing the difference in residual film thickness, and lowering the polishing speed. , to achieve the effect of small residual film thickness differen

Inactive Publication Date: 2008-10-16
HITACHI CHEM CO LTD
View PDF1 Cites 21 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides a CMP polishing slurry and a polishing method that can reduce the difference in residual film thickness due to pattern density difference. This is achieved by using a specific combination of cerium oxide particles, a dispersant, water, and a polymer. The polymer can be a polymer of at least one of methacrylic acid and its salt, or a polymer of at least one of methacrylic acid and its salt, as well as a monomer having an unsaturated double bond. The amount of cerium oxide particles added is between 0.1 and 5 mass parts with respect to the total amount of monomers. The pH of the polishing slurry is between 4.5 and 6.0, and it may also contain a strong acid ion. The method involves polishing a substrate with the CMP polishing slurry while moving the substrate and the polishing table relative to each other.

Problems solved by technology

However, such a fumed silica polishing slurry still has a problem that the polishing speed is lower.
However, colloidal silica-based polishing slurries have a smaller polishing speed ratio between the silicon oxide film and the stopper film at approximately 3, and thus, do not have properties practically usable for shallow trench isolation.
However, cerium oxide CMP polishing slurries containing an additive of water-soluble polymer as the monomer could not reduce the difference in residual film thickness due to the pattern density difference of the film to be polished sufficiently.
Accordingly, it is not regarded as a monomer suitable for the polymer for use as the additive.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

example

Example 1

Preparation of Supplementary Solution

[0084]1,000 g of deionized water and 200 g of 2-propanol were placed in a 3-L preparative flask and heated to 90° C. under nitrogen gas atmosphere; a mixture of 561 g of a methacrylic acid and 64 g of deionized water and a solution of 64 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]bisulfate dihydrate salt dissolved in 536 g of deionized water were added respectively into the flask over 2 hours. The mixture was then kept at 90° C. for 3 hours and cooled, to give a supplementary solution, a polymethacrylic acid solution containing a polymer (D).

[0085]The content of the nonvolatile matter therein was found to be 25 mass %. The weight-average molecular weight of the polymethacrylic acid solution thus obtained, as determined with a HPLC pump (Model No. L-7100, manufactured by Hitachi, Ltd.) equipped with a differential refractometer (Model No. L-3300, manufactured by Hitachi, Ltd.) and a GPC column (Model No. Gelpack GL-W550, manufactured b...

example 2

Preparation of Supplementary Solution

[0095]600 g of deionized water and 600 g of 2-propanol were placed in a 3-L preparative flask and heated to 85° C. under nitrogen gas atmosphere; a mixture of 536 g of a methacrylic acid and 45 g of an acrylic acid and a solution of 32 g of ammonium persulfate dissolved in 600 g of deionized were added respectively into the flask over 2 hours. The mixture was then kept at 85° C. for 3 hours and cooled, to give a supplementary solution, a polyacrylic acid-90 mol % methacrylic acid copolymer solution (methacrylic acid:acrylic acid=9:1). The content of the nonvolatile matter therein was found to be 25 mass %. The weight-average molecular weight of the polyacrylic acid-90 mol % methacrylic acid copolymer thus obtained, as determined in the same manner as in Example 1, was 23,000 (as polyethylene glycol).

[0096](Preparation of Polishing Slurry)

[0097]36 g of the supplementary solution thus obtained, polyacrylic acid-90 mol % methacrylic acid copolymer s...

example 3

Preparation of Supplementary Solution

[0100]1,000 g of deionized water and 200 g of 2-propanol were placed in a 3-L preparative flask and heated to 90° C. under nitrogen gas atmosphere; a mixture of 401 g of a methacrylic acid and 134 g of an acrylic acid and a solution of 59 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dissolved in 589 g of aqueous 5 mass % sulfuric acid were added respectively into the flask over 2 hours. The mixture was then kept at 90° C. for 3 hours and cooled, to give a supplementary solution, polyacrylic acid-70 mol % methacrylic acid copolymer solution. The content of the nonvolatile matter therein was found to be 25 mass %. The weight-average molecular weight of the polyacrylic acid-70 mol % methacrylic acid copolymer thus obtained, as determined in the same manner as in Example 1, was 22,000 (as polyethylene glycol).

[0101](Preparation of Polishing Slurry)

[0102]36 g of the supplementary solution thus obtained, polyacrylic acid-70 mol % methacrylic acid cop...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
particle diameteraaaaaaaaaa
crystallite diameteraaaaaaaaaa
crystallite diameteraaaaaaaaaa
Login to View More

Abstract

A CMP polishing slurry of the present invention contains cerium oxide particles, water, and a polymer of at least one of a methacrylic acid and the salt thereof, and / or a polymer of at least one of a methacrylic acid and the salt thereof and a monomer having an unsaturated double bond, preferably contains furthermore a dispersant or a polymer of monomers containing at least one of an acrylic acid and the salt thereof. The present invention provides a CMP polishing slurry and a polishing method that, after polishing, give a polished film having a smaller difference in residual film thickness due to a pattern density difference.

Description

TECHNICAL FIELD[0001]The present invention relates to a CMP polishing slurry and a method of polishing a substrate that are favorably used in a step of smoothening the surface of a substrate in production of semiconductor devices, in particular in steps of smoothening an inter layer dielectric film and a BPSG (silicon dioxide film doped with boron and phosphorus) film and forming a shallow trench isolation film, and others.BACKGROUND ART[0002]Currently under research and development are processing methods for improvement in density and miniaturization in production of ULSI semiconductor devices. One of the methods, chemical mechanical polishing (CMP) technology, is now a technology essential in production of semiconductor devices, for example, for smoothening of an inter layer dielectric film, forming a shallow trench device isolation, and forming plugged and embedded metal wiring.[0003]In production of semiconductor devices, inorganic insulation film layers such as a silicon oxide ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): B24B29/02C09K3/14B24B37/00H01L21/304
CPCC09K3/1463C09G1/02C09K3/14
Inventor FUKASAWA, MASATOKOYAMA, NAOYUKIHAGA, KOUJIAKUTSU, TOSHIAKI
Owner HITACHI CHEM CO LTD