Abrasive compounds for semiconductor planarization

Abstract

A polishing slurry for semiconductor planarization containing cerium oxide particles and water, wherein the content of the cerium oxide particles having a diameter of 3 μm or more is 500 ppm or less (weight ratio) in a solid, preferably 100 ppm or less and it is more preferable that D99 (99% by volume of the whole particles in polishing slurry) of the cerium oxide particles is 1 μm or less. The polishing slurry can reduce the generation of scratches, and can polish a surface of the semiconductor substrate in the wiring formation process of semiconductor device precisely at a high speed.

Description

TECHNICAL FIELD [0001] The present invention relates to a polishing slurry, and particularly relates to polishing slurries for semiconductor planarization. BACKGROUND ART [0002] A precise polish process for polishing the surface of a material is required in, for example, optical disk substrates, a magnetic disks, glass substrates for flat panel displays, clock boards, camera lenses, glass material used for various lenses and crystal material for filters or the like for optical components, substrates of a silicon wafer or the like for semiconductors, and insulated films, metal layers and barrier layers or the like formed in each process for manufacturing semiconductor devices. The surfaces of these materials require high accuracy polishing. Therefore, for example, polishing agents have been generally used, using silica, zirconium oxide and alumina or the like alone or in combination of two or more kinds as polish particles. Referring to a form of the polishing agent, for example, a s...

AI Technical Summary

Benefits of technology

[0011] It is an object of the present invention to provide a polishing slurry for semiconductor planarization capable of maintaining a suitable polishing speed, reducing the generation of the scratches and precisely polishing the surface of the semiconductor.

[0012] The present inventor has conducted earnest studies of the reduction of the scratches due to the polishing slurry for semiconductor planarization. As a result, the present inventor found that the scratches can be decreased by removing the coarse particles contained in a small amount in the polishing slurry, thereby the present invention was accomplished.

[0016] A surface of a semiconductor can be polished at a high speed in a wiring formation process by the present invention. Also, the surface of the semiconductor has good flatness, and scratches can be reduced.

Problems solved by technology

However, since the polishing speed of the silica polishing slurry is slow, attentions have been recently focused on a cerium oxide polishing slurry containing cerium oxide having a fast polishing speed (for example, see Japanese Patent Application Laid-Open Nos. 2000-26840 and 2-371267).

However, the cerium oxide polishing slurry has a problem of generating more scratches as compared with the silica polishing slurry.

Though it has been presumed that the scratches generated in the polish process relate to the particle diameter of the polishing slurry, quantitive evaluation results have been seldom obtained.

Though it has been considered that the cerium oxide polishing slurry has a larger mean particle diameter than that of the silica polishing slurry and has a great content of the coarse particles, since a measurement technique having high sensitivity has not been established, the reliability of the measurement results has been inadequate.

Therefore, the relationship between the coarse particles and the scratches is merely conceptually understood, and an effective specific measure has been deficient.

However, even if the maximum particle diameter detected by the particle size distribution meter is reduced, the prevention of the scratches is limited, so that responding to integration of the semiconductor these days has been difficult.

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