Radiation-sensitive resin composition for liquid immersion exposure, polymer and method for forming resist pattern

Abstract

Disclosed is a radiation-sensitive resin composition for liquid immersion exposure, which has high transparency to radiation, excellent basic properties for resists such as sensitivity and excellent minimum collapse dimensions (collapse), and improves variations in the pattern shape during a liquid immersion exposure process. A polymer and a method for forming a resist pattern are also disclosed. The radiation-sensitive resin composition for liquid immersion exposure contains (A) a resin component, (B) a radiation-sensitive acid generator and (C) a solvent. The resin component (A) contains more than 50% by mass of an acid-cleavable group-containing resin (A1) containing a repeating unit (a1) having a fluorine atom and an acid-cleavable group in a side chain, when the resin component (A) is taken as 100% by mass.

Description

technical field [0001] The invention relates to a radiation-sensitive resin composition for liquid immersion exposure, a polymer and a resist pattern forming method. More specifically, it relates to a laser that can be preferably used in the application of various radiation such as extreme ultraviolet rays typified by KrF excimer laser and ArF excimer laser, X-rays such as synchrotron radiation, and charged particle rays such as electron beams. A radiation-sensitive resin composition for liquid immersion exposure of a chemically amplified resist useful in microfabrication, a polymer, and a method for forming a resist pattern. Background technique [0002] In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, photolithography technology capable of microfabrication at a level of 0.10 μm or less is recently required. However, in the conventional photolithography process, near-ultraviol...

AI Technical Summary

Problems solved by technology

When the amount of the elution is large, there are problems such as damage to the lens, failure to obtain a predetermined pattern shape, or failure to obtain sufficient resolution.

[0011] In addition, when water is used as the liquid for immersion exposure, if the receding contact angle of water in the resist film is low, there is a problem that the liquid for immersion exposure such as water overflows from the edge of the wafer during high-speed scanning exposure. and drop; due to poor water isolation, watermarks (drop marks) (watermark defects) remain; or due to water penetration into the resist film, the solubility of the film is reduced, and the pattern shape that should be developed cannot be fully analyzed locally. Developing defects, such as dissolution residue defects that cause pattern shape defects due to poor imaging

[0012] Furthermore, even for resists using resins or additives as shown in Patent Documents 1 to 3, the receding contact angle between the resist film and water may not be sufficient, and liquid for liquid immersion exposure such as water tends to flow from the surface during high-speed scanning exposure. The edge of the wafer overflows and falls, or development defects such as watermark defects

In addition, it cannot be said that the suppression of the amount of leached substances such as acid generators in water is sufficient.

In particular, as disclosed in Patent Document 3, there is a problem that the pattern shape after development is uneven in a system in which components having different dissolution methods are mixed.

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