erably distilled water. Pure water obtained by further filtering the distilled water through an ion exchange filter or the like may be also used. 

The electrical resistance of water is preferably 18.3 MQcm or more, and TOC (total organic carbon) is preferably 20 ppb or less. Also, the water is preferably subjected to a deaeration treatment. 

The lithography performance can be enhanced by elevating the refractive index of the immersion liquid. From such a standpoint, an additive for elevating the refractive index may be added to water, or heavy water (D$_{2}$ 0) may be used in place of water. 

In order to prevent the film from contacting directly with the immersion liquid, an immersion liquid sparingly soluble 15 film (hereinafter, sometimes referred to as "topcoat") may be provided between the film formed of the composition of the present invention and the immersion liquid. The functions required of the topcoat are suitability for coating on the resist upper layer part, transparency to radiation particularly of 193 20 nm, and difficult solubility in the immersion liquid. It is preferred that the topcoat does not intermix with the resist and can be uniformly coated on the resist upper layer. 

In view of transparency to light of 193 nm, the topcoat is preferably a polymer not abundantly containing an aromatic 25 moiety. Specifically, this polymer includes a hydrocarbon polymer, an acrylic acid ester polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-contain› ing polymer, a fluorine-containing polymer, and the like. The above-described hydrophobic resin (HR) is suitable also as 30 the topcoat. From the standpoint that elution of impurities into the immersion liquid from the topcoat leads to contami› nation of the optical lens, the amount of residual monomer components of the polymer contained in the topcoat is pref› erably smaller. 35 

On removing the topcoat, a developer may be used, or a release agent may be separately used. The release agent is preferably a solvent less permeating the resist film. From the standpoint that the removing step can be performed simulta› neously with the film development step, the topcoat is pref- erably removable with an alkali developer and for the removal with an alkali developer, the topcoat is preferably acidic, but in view of non-intermixing with the film, the topcoat may be neutral or alkaline. 

With no difference in the refractive index between the topcoat and the immersion liquid, the resolution is enhanced. In the case of using water as the immersion liquid at the exposure with an ArF excimer laser (wavelength: 193 nm), the topcoat for ArF immersion exposure preferably has a refractive index close to the refractive index of the immersion liquid. From the standpoint of making the refractive index close to that of the immersion liquid, the topcoat preferably contains a fluorine atom. Also, in view of transparency and refractive index, the topcoat is preferably a thin film. 

The topcoat is preferably free of intermixing with the film and further with the immersion liquid. From this standpoint, when the immersion liquid is water, the solvent used for the topcoat is preferably a medium that is sparingly soluble in the solvent used for the composition of the present invention and is water-insoluble. On the other hand, when the immersion liquid is an organic solvent, the topcoat may be either water› soluble or water-insoluble. 

The development step is described below. 

In the development step, an alkali developer is usually used. 

The alkali developer includes, for example, an alkaline aqueous solution containing inorganic alkalis such as sodium 

hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate and aqueous annnonia, primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alco› hol amines such as dimethylethanolamine and triethanola› mine, quaternary ammonium salts such as tetramethylammo› nium hydroxide and tetraethylammonium hydroxide, or cyclic amines such as pyrrole and piperidine. 

In the alkali developer, alcohols and/or a surfactant may be added each in an appropriate amount. 

The concentration of the alkali developer is usually from 0.1 to 20 mass%. The pH of the alkali developer is usually from 10.0 to 15.0. 

Details of the process when fabricating an imprint mold by using the composition of the present invention may be refer to, for example, Japanese Patent 4,109,085, JP-A-2008- 162101, and "Yoshihiko Hirai (compiler), Nanoimprint no Kiso to Gijutsu Kaihatsu•Oyo Tenkai-Nanoimprint no Kiban Gijutsu to Saishin no Gijutsu Tenkai (Basic and Technology Expansion•Application Development of Nanoimprint-Sub› strate Technology of Nanoimprint and Latest Technology Expansion), Frontier Shuppan". 

The present invention also includes an electronic device manufacturing method involving the above-described pattern forming method of the present invention, and an electronic device manufactured by this manufacturing method. 

The electronic device of the present invention is suitably mounted on electric and electronic equipment (home elec› tronic device, OA •media-related device, optical device com› munication device, etc.). 

The present invention is described in greater detail below, but the present invention is not limited thereto. 

## Examples IA to 19A and Comparative Examples IA and2A 

<Preparation of Resist> 

The components shown in Table 2 below were dissolved in the solvent to prepare a solution having a solid content con› centration of 4.0 mass %, and the obtained solution was filtered through a polytetrafluoroethylene filter having a pore size of 0.03 µm to prepare a positive resist solution. The positive resist compositions (resist solutions) prepared were evaluated by the following method and the results are shown in Table 2. 

<Evaluation of Resist> 

An organic antireflection film, ARC29A (produced by Nis› san Chemical Industries, Ltd.), was coated on a silicon wafer and baked at 205° C. for 60 seconds to form an antireflection film having a thickness of 78 nm, and the positive resist composition prepared was coated thereon and baked at 130° C. for 60 seconds to form a resist film having a thickness of 120 nm. The obtained resist film was exposed through a 6% halftone mask having a 1: 1 line-and-space pattern with a line width of 75 nm by using an ArF excimer laser scanner (PAS5500/1100, manufactured by ASML, NA: 0.75). There- 

## EXAMPLES 

## Example A 

