An object of the present invention is to provide a novel fluorine-containing polymer, a radiation-sensitive resin composition for liquid immersion lithography which contains the fluorine-containing polymer, which leads to a pattern having an excellent shape and excellent depth of focus, wherein the amount of an eluted component in a liquid for liquid immersion lithography such as water that comes in contact with the resist during exposure in liquid immersion lithography is little, and which provides a larger receding contact angle between the resist film and the liquid for liquid immersion lithography such as water, and a method for purifying the fluorine-containing polymer. The present resin composition comprises a novel fluorine-containing polymer (A) containing repeating units represented by the general formulae (1) and (2) and having Mw of 1,000-50,000, a resin (B) having an acid-unstable group, a radiation-sensitive acid generator (C), a nitrogen-containing compound (D) and a solvent (E).

An actinic ray-sensitive or radiation-sensitive resin composition contains a resin (P) having a partial structure represented by General Formula (X), and a compound capable of generating an acid upon irradiation with actinic ray or radiation. ##STR00001##

Provided are a composition for forming an upper layer film for a photoresist, including a polymer having a molecular weight distribution in which a peak area of a high-molecular-weight component having a weight-average molecular weight of 40,000 or more accounts for 0.1% or less with respect to the entire peak area in the molecular weight distribution, measured by the gel permeation chromatography.

An object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition by which a pattern having excellent LWR performance can be formed. In addition, another object of the present invention is to provide a resist film, a pattern forming method, and a method for manufacturing an electronic device, each relating to the actinic ray-sensitive or radiation-sensitive resin composition.

The actinic ray-sensitive or radiation-sensitive resin composition of an embodiment of the present invention is an actinic ray-sensitive or radiation-sensitive resin composition including a resin of which polarity increases through decomposition by the action of an acid, and a compound that generates an acid upon irradiation with actinic rays or radiation, in which the resin has a repeating unit represented by General Formula (1) as a repeating unit having an acid-decomposable group, and the compound that generates an acid upon irradiation with actinic rays or radiation includes any one or more of a compound (I) or a compound (II).

A composition for forming an organic film contains a polymer having a partial structure shown by the following general formula (1A) or (1B), and an organic solvent, where Ar.sub.1 and Ar2 represent a benzene ring or naphthalene ring which optionally have a substituent; X represents a single bond or methylene group; a broken line represents a bonding arm; R represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; and W.sub.1 represents a hydroxyl group, an alkyloxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring optionally having a substituent. A composition for forming an organic film, the composition containing a polymer with high carbon content and thermosetting property as to enable high etching resistance and excellent twisting resistance; a patterning process using the composition; and a polymer suitable for the composition for forming an organic film. ##STR00001##

A method of forming a pattern of a semiconductor device includes: forming a first mask pattern comprising first mask lines extending in a first direction in a cell region and second mask lines extending in the first direction in a first core region, the first mask pattern covering a second core region; forming, on the first mask pattern, a second mask pattern comprising third mask lines extending in a second direction in the cell region and fourth mask lines extending in the second direction in the second core region, the second mask pattern covering the first core region; and forming a third mask pattern by using the second mask pattern, the third mask pattern comprising island-type masks in the cell region, fifth mask lines extending in the first direction in the first core region, and sixth mask lines extending in the second direction in the second core region.

A method of forming a device includes forming a hard mask layer over an underlying layer of a substrate, forming an anti-reflective coating layer over the hard mask layer, forming a patterned resist layer over the anti-reflective coating layer, and forming a mandrel including the anti-reflective coating layer by patterning the anti-reflective coating layer using the patterned resist layer as an etch mask. The method includes forming a sidewall spacer on the mandrel including the anti-reflective coating layer, forming a freestanding spacer on the hard mask layer by removing the mandrel from the anti-reflective coating layer, and using the freestanding spacer as an etch mask, patterning the underlying layer of the substrate.

A process for producing a photoresist pattern comprising steps (1) to (5); (1) applying a photoresist composition onto a substrate, said photoresist composition comprising an acid generator and a resin which comprises a structural unit having an acid-liable group; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer; (4) heating the exposed composition layer; and (5) developing the heated composition layer with a developer which comprises butyl acetate, wherein a distance of Hansen solubility parameters between the resin and butyl acetate is from 3.3 to 4.3, the distance is calculated from formula (1):

R=(4×(δd.sub.R−15.8).sup.2+(δp.sub.R−3.7).sup.2+(δh.sub.R−6.3).sup.2).sub.1/2   (1) in which δd.sub.R represents a dispersion parameter of the resin, δp.sub.R represents a polarity parameter of the resin, δh.sub.R represents a hydrogen bonding parameter of the resin, and R represents the distance, and a film retention ratio of the photoresist pattern relative to the composition layer is adjusted to 65% or more.

A sulfonium compound having formula (1) exerts a satisfactory acid diffusion control function wherein R.sup.1, R.sup.2 and R.sup.3 are a C.sub.1-C.sub.20 monovalent hydrocarbon group which may contain a heteroatom, p=0-5, q=0-5, and r=0-4. A resist composition comprising the sulfonium compound is processed by lithography to form a resist pattern with improved resolution, LWR, MEF and CDU.

##STR00001##

A photoresist composition comprising an acid generator and a resin which comprises one or more structural units (a1) derived from a monomer (a1) having an acid-liable group, all of monomers (a1) showing a distance of Hansen solubility parameters between the monomer (a1) and butyl acetate in the range of 3 to 5, the distance being calculated from formula (1):

R=(4×(δd.sub.m−15.8).sup.2+(δp.sub.m−3.7).sup.2+(δh.sub.m−6.3).sup.2).sup.1/2  (1)

in which δd.sub.m represents a dispersion parameter of a monomer, δp.sub.m represents a polarity parameter of a monomer, δh.sub.m represents a hydrogen bonding parameter of a monomer, and R represents a distance of Hansen solubility parameters, and at least one of the monomers (a1) showing a difference of R between the monomer (a1) and a compound in which an acid is removed from the monomer (a1) in the range of not less than 5.