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 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.

A photoresist composition comprising an acid generator and a resin which comprises a structural unit having an acid-liable group, the acid generator generating an acid (I) or an acid (II): the acid (I) showing a hydrogen bonding parameter in the range of 12 (MPa).sup.1/2 to 15 (MPa).sup.1/2 and a polarity parameter in the range of 15 (MPa).sup.1/2 or more; the acid (II) showing a hydrogen bonding parameter in the range of 12 (MPa).sup.1/2 to 15 (MPa).sup.1/2, and a distance of Hansen solubility parameters between the acid (II) and γ-butyrolactone being 7.5 or less, and the distance being calculated from formula (1):

R=(4×(δd.sub.A−18).sup.2+(δp.sub.A−16.6).sup.2+(δh.sub.A−7.4).sup.2).sup.1/2  (1)

in which δd.sub.A represents a dispersion parameter of an acid, δp.sub.A represents a polarity parameter of an acid, δh.sub.A represents a hydrogen bonding parameter of an acid, and R represents a distance of Hansen solubility parameters between an acid and γ-butyrolactone.

A carboxylic acid onium salt of formula (1) exerts a satisfactory acid diffusion control (or quencher) function. A resist composition comprising the carboxylic acid onium salt can be processed by DUV or EUV lithography to form a resist pattern with improved resolution, reduced LWR and minimal defects after development.

##STR00001##

A resist composition comprising a quencher containing a nitroxyl radical having an iodized aromatic ring is provided. The resist composition has a high sensitivity and forms a pattern with improved LWR or CDU, independent of whether it is of positive or negative tone.

A radiation-sensitive composition includes an organic acid, particles including a metal oxide as a principal component, and an acid generating agent that is capable of generating an acid upon irradiation with a radioactive ray. A pKa, which is a logarithmic value of a reciprocal of an acid dissociation constant Ka, of the acid generated from the acid generating agent is less than a pKa of the organic acid. The acid generating agent satisfies at least one of conditions (i) and (ii): (i) a van der Waals volume of the acid is no less than 2.1×10.sup.−28 m.sup.3; and (ii) the acid generating agent includes a plurality of groups that are capable of generating an acid.

A monomer having an onium salt structure represented by formula (1) gives a polymer which is fully compatible with resist components. A resist composition comprising the polymer has advantages including reduced acid diffusion, high sensitivity, high resolution, a good balance of lithography properties, and less defects, and is quite effective for precise micropatterning.

##STR00001##

There is provided a new coating liquid for resist pattern coating. A coating liquid for resist pattern coating comprising a component A that is a polymer including at least one hydroxy group or carboxy group; a component B that is a sulfonic acid of A-SO.sub.3H (where A is a linear or branched alkyl group or fluorinated alkyl group having a carbon atom number of 1 to 16, an aromatic group having at least one of the alkyl group or the fluorinated alkyl group as a substituent, or a C.sub.4-16 alicyclic group optionally having a substituent); and a component C that is an organic solvent capable of dissolving the polymer and including ether or ketone compound of R.sup.1—O—R.sup.2 and/or R.sup.1—C(═O)—R.sup.2 (where R.sup.1 is a linear, branched, or cyclic alkyl group or fluorinated alkyl group having a carbon atom number of 3 to 16; and R.sup.2 is a linear, branched, or cyclic alkyl group or fluorinated alkyl group having a carbon atom number of 1 to 16), a method of forming a resist pattern using the coating liquid, and a method for forming a reverse pattern using the coating liquid.

A mask blank with phase shift film where changes in transmittance and phase shift to an exposure light of an ArF excimer laser are suppressed. The film transmits light of an ArF excimer laser at a transmittance of 2% or more and less than 10% and generates a phase difference of 150 degrees or more and 190 degrees or less between the exposure light transmitted through the phase shift film and the exposure light transmitted through the air for the same distance as a thickness of the phase shift film. The film has a stacked lower layer and upper layer, the lower layer containing metal and silicon and substantially free of oxygen. The upper layer containing metal, silicon, nitrogen, and oxygen. The lower layer is thinner than the upper layer, and the ratio of metal to metal and silicon of the upper layer is less than the lower layer.

Disclosed herein are an organic processing liquid for resist film patterning which is capable of suppressing the occurrence of defects in resist patterns, and a pattern forming method. Provided is an organic processing liquid for resist film patterning, which is used to carry out at least one of developing or cleaning of a resist film obtained from an actinic ray-sensitive or radiation-sensitive composition, the liquid including an organic solvent, in which the content of an oxidant in the organic processing liquid is 10 mmol/L or less.