solvents, there can be mentioned, for example, those described in section [0244] et seq. of US 2008/0248425 Al and the like. 

Among the above solvents, an alkylene glycol monoalkyl ether carboxylate, an alkylene glycol monoalkyl ether and ethyl lactate are especially preferred. 

These solvents may be used alone or in combination. When a plurality of solvents are mixed together, it is preferred to mix a hydroxy lated solvent with a non-hydroxy lated solvent. The mass ratio ofhydroxylated solvent to non-hydroxylated sol› vent is in the range of 1/99 to 99/1, preferably 10/90 to 90/10 and more preferably 20/80 to 60/40. 

The hydroxylated solvent is preferably an alkylene glycol monoalkyl ether and an alkyl lactate. The non-hydroxylated solvent is preferably an alkylene glycol monoalkyl ether car› boxylate. 

The amount of solvent used is not particularly limited. However, the amount is generally so regulated that the total solid concentration of the composition falls in the range of preferably 0.5 to 30 mass%, more preferably 1.0 to 10 mass %. In particular when an electron beam or EUV lithography is carried out using the composition of the present invention, the amount is so regulated that the concentration falls in the range of preferably 2.0 to 6.0 mass %, more preferably 2.0 to 4.5 mass%. 

(Other Additive) 

The positive or negative actinic-ray- or radiation-sensitive resin composition of the present invention may further according to necessity contain a dye, a plasticizer, a photo› sensitizer, a light absorber, a compound capable of accelerat› ing the dissolution in a developer (for example, a phenolic compound of 1000 or less molecular weight, or a carboxy› lated alicyclic or aliphatic compound), etc. Still further, appropriate use can be made of compounds having a func› tional group as a proton acceptor described in, for example, JP-A’s 2006-208781 and 2007-286574. 

[7] Method of Forming Pattern 

The positive or negative actinic-ray- or radiation-sensitive resin composition of the present invention is typically used in the following manner. Namely, the composition of the present invention is typically applied onto a support, such as a sub› strate, thereby forming a film. The thickness of the film is preferably in the range of 0.02 to 0.1 µm. The method of application onto a substrate is preferably a spin coating. The spin coating is performed at a rotating speed of preferably 1000 to 3000 rpm. 

For example, the composition is applied onto, for example, any of substrates ( e.g., silicon/silicon dioxide coating, silicon nitride and chromium-vapor-deposited quartz substrate, etc.) for use in the production of precision integrated circuit devices, etc. by appropriate application means, such as a spinner or a coater. The thus applied composition is dried, thereby obtaining an actinic-ray- or radiation-sensitive film (hereinafter also referred to as a photosensitive film). The application of the composition to the substrate can be pre- ceded by the application of a heretofore known antireflection film. 

The resultant photosensitive film is exposed to actinic rays or radiation, preferably baked (heated), and developed. Thus, a favorable pattern can be obtained. From the viewpoint of sensitivity and stability, it is preferred for the baking tempera› ture to be in the range of 80 to 150° C., especially 90 to 130° C. 

As the actinic rays or radiation, there can be mentioned, for example, infrared light, visible light, ultraviolet light, far› ultraviolet light, extreme ultraviolet light, X-rays or an elec› tron beam. It is preferred for the actinic rays or radiation to 

have, for example, a wavelength of 250 nm or shorter, espe› cially 220 nm or shorter. As such actinic rays or radiation, there can be mentioned, for example, a KrF excimer laser (248 nm), anArF excimer laser (193 nm), an F $_{2 }$ excimer laser (157 nm), X-rays or an electron beam. As especially preferred actinic rays or radiation, there can be mentioned an ArF excimerlaser, anF$_{2 }$ excimerlaser(157 nm), EUV (13 nm) or an electron beam. 

The exposure performed in the condition that the interstice between the photosensitive film and a lens is filled with a liquid (for example, pure water) whose refractive index is higher than that of air, namely, liquid-immersion exposure may be carried out in the stage of the exposure to actinic rays or radiation. This liquid-immersion exposure can enhance the resolution. At the liquid-immersion exposure, for the preven› tion of any contact of the resist film with the immersion liquid, a film that is highly insoluble in the immersion liquid (also referred to as a "top coat") may be disposed on the film and between the film and the immersion liquid. As another means for the prevention of any contact of the film with the immer› sion liquid, a hydrophobic resin (HR) may be added to the composition in advance. 

The hydrophobic resin (HR) will be described below. 

In the case of exposure of the film of the composition of the present invention via the liquid immersion medium, a hydro› phobic resin (HR) may be further added according to neces› sity. This would bring about uneven localization of the hydro› phobic resin (HR) on the surface layer of the film. When the liquid immersion medium is water, there would be attained an improvement of receding contact angle on the surface of the film with reference to water upon formation of the film. The receding contact angle of the surface of the film can be increased by the addition of the hydrophobic resin (HR). The receding contact angle of the film is preferably in the range of 60° to 90°, more preferably 70° or higher. Although the hydrophobic resin (HR) is unevenly localized on the interface as aforementioned, differing from the surfactant, the hydro› phobic resin does not necessarily have to have a hydrophilic group in its molecule and does not need to contribute toward uniform mixing of polar/nonpolar substances. 

The receding contact angle refers to a contact angle deter› mined when the contact line at a droplet-substrate interface draws back. It is generally known that the receding contact angle is useful in the simulation of droplet mobility in a dynamic condition. In a simple definition, the receding con› tact angle can be defined as the contact angle exhibited at the recession of the droplet interface at the time of, after appli› cation of a droplet discharged from a needle tip onto a sub› strate, re-indrawing the droplet into the needle. Generally, the receding contact angle can be measured according to a method of contact angle measurement known as the dilation/ contraction method. 

In the operation ofliquid immersion exposure, it is needed for the liquid for liquid immersion to move on a wafer while tracking the movement of an exposure head involving high› speed scanning on the wafer and thus forming an exposure pattern. Therefore, the contact angle of the liquid for liquid immersion with respect to the resist film in dynamic condition is important, and it is required for the resist to be capable of tracking the high-speed scanning of the exposure head with› out leaving any droplets. 

As the hydrophobic resin (HR) is localized in a surface portion of the film, it is preferred for the same to contain a fluorine atom or a silicon atom. The fluorine atom or silicon atom may be contained in the principal chain of the hydro› phobic resin (HR) or may be introduced in a side chain(s) thereof as a substituent. 

