Cerium oxide slurry, cerium oxide polishing slurry and method for polishing substrate using the same

Abstract

The present invention provides a cerium oxide slurry, a cerium oxide polishing slurry, and a method of polishing a substrate by using the same, wherein decrease of scratches and polish at high speed can be realized by reducing the content of coarse grains by improving in the disperse state of cerium oxide particles. The invention relates to a cerium oxide slurry containing cerium oxide particles, dispersant and water, in which the ratio of weight of cerium oxide / weight of dispersant is in a range of 20 to 80 and relates a cerium oxide polishing slurry comprising the cerium oxide slurry and additives such as a water-soluble polymer.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a cerium oxide slurry, a cerium oxide polishing slurry, and a method of polishing a substrate using the same. [0003] 2. Description of the Related Art [0004] In recent manufacturing process of ULSI semiconductor devices, various processing technologies for higher density and finer size are researched and developed. One of them is CMP (chemical mechanical polishing) technology, which is now an indispensable technology in manufacturing process of semiconductor devices for flattening of interlayer dielectrics or BPSG films (silicon dioxide film doped with boron or phosphorus), isolation and forming of shallow trench devices, and forming of plugged and embedded metal wiring. [0005] Conventionally, in manufacturing process of semiconductor devices, inorganic dielectrics layer such as silicon oxide insulation film are formed by plasma CVD or low-pressure CVD method. As chemical-mechanical ...

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Benefits of technology

[0012] It is hence an object of the invention to decrease scratches and polish at high speed by reducing the content ratio of coarse grains. For this purpose, the invention provides a cerium oxide slurry, a cerium oxide polishing slurry, and a method of polishing a substrate by using the same, improved in the disperse state of cerium oxide particles by controlling the weight of cerium oxide particles and the weight of dispersant to an optimum ratio.

[0021] The cerium oxide slurry, cerium oxide polishing solution (or called polishing slurry), and polishing method of substrate using the same of the invention are capable of decreasing scratches and increasing the polishing speed, by defining the ratio of cerium oxide concentration / dispersant concentration so that the content of coarse grains may be smaller. Further, by minimizing causes of scratches due to aggregate particles, both high yield and high throughput can be realized.

Problems solved by technology

However, such fumed silica polishing slurry is low in polishing speed.

However, the polishing slurry of colloid silica composition is small in the polishing speed ratio between the silicon oxide film and stopper film, being about 3, and so far from practical property for shallow trench isolation.

When the cerium oxide polishing slurry for glass surface polishing is directly used in polishing of inorganic dielectrics, however, primary particle size of cerium oxide is too large, and the insulation film surface may be scratched.

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