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benzotrifluoride, perfluorobenzene, perfluoro(tributy- lamine ), ClCF$_{2}$CFClCF$_{2}$CFCl$_{2 }$ and the like. 

Those fluorine-containing solvents may be used solely, in a mixture of two or more thereof or in a mixture of one or more of the fluorine-containing solvents and non-fluorine-contain- ing solvents. 

The amount of the solvent (C) is selected depending on kind of solids to be dissolved, kind of a substrate to be coated, an intended coating thickness, etc. From the viewpoint of easiness of coating, the solvent is used in such an amount that the concentration of the whole solids of the resist composition becomes from 0.5 to 70% by weight, preferably from 1 to 50% by weight, particularly preferably from 5 to 30% by weight. 

The chemically amplifying type resist composition of the present invention is subjected to resist pattern formation according to conventional photoresist technology. In order to form a pattern properly, first, a solution of the photoresist composition is applied on a substrate such as a silicon wafer by a spinner or the like, and is dried to form a photosensitive layer. A pattern is drawn by irradiating the layer with ultra› violet ray, deep-UV, excimer laser or X-ray by a reduction projection exposure system, etc. through a proper mask pat› tern or the pattern is drawn with an electron beam, and then heating follows. The layer is then subjected to developing treatment with a developing solution, for example, an aque› ous alkali solution such as an aqueous solution of 1 to 10% by weight oftetramethyl ammonium hydroxide. Thus an image faithful to the mask pattern can be obtained by the above- mentioned pattern forming method. 

It was found that by using the chemically amplifying type resist composition of the present invention, a resist film (pho› tosensitive layer) having a high transparency even in a vacuum ultraviolet region could be formed. Therefore the resist composition of the present invention can be preferably used particularly for a photo lithography process using a F 2 laser (wavelength of 157 nm) which is under development aiming at a technology node of0.1 µm. 

The present invention is then explained below by means of $_{40 }$ Examples and Preparation Examples, but is not limited to them. 

In the following Examples and Preparation Examples, equipment and measuring conditions used for evaluation of physical properties are as follows. 

(1) NMR: NMR analyzer isAC-300 available from BRUKER CO.,LTD. 

Measuring conditions of1 H-NMR: 300 MHz (tetramethylsi› lane=0 ppm) 

Measuring conditions of$^{19}$F-NMR: 300 MHz (trichlorofluo- romethane=0 ppm) 

(2) IR analysis: Measuring is carried out at room temperature with a Fourier-transform infrared spectrophotometer 1760X available from Perkin Elmer Co., Ltd. 

(3) GPC: A number average molecular weight is calculated from data measured by gel permeation chromatography (GPC) by using GPC HLC-8020 available from Toso Kabushiki Kaisha and columns available from Shodex Co., Ltd. (one GPC KF-801, one GPC KF-802 and two GPC KF-806M were connected in series) and flowing tetrahy› drofuran (THF) as a solvent at a flowing rate of 1 ml/minute. 

( 4) GC-Mass: Measurement is carried out by using QPl 000 available from Shimadzu Corporation. Detection is carried 65 out by an impact ionization method at an ionization energy of70 eV. 

(Synthesis ofNorbornene Having --COP Group) 

A 500 ml four-necked glass flask equipped with a reflux condenser, thermometer, stirrer and dropping funnel was charged with 136 g of cyclopentadiene and 1.0 g of hydro› quinone and was cooled to 0° to 5° C. Thereto was added dropwise 233 g of a-fluoroacrylic acid fluoride (CH$_{2}$=CFCOF) over three hours in nitrogen gas stream. After completion of the addition, stirring was carried out for three hours at room temperature. 

The reaction mixture was subjected to distillation under reduced pressure to obtain 3 60 g of 5-norbornene-2-carboxy› lic acid fluoride: 

<img src='content_image/947662.jpg'>

(melting point: 73° to 75° C./45 mmHg) which is a nor› bornene compound having --CO F group (yield: 90%) 

The above-mentioned structure of this compound was determined by GC-Mass, $^{19}$F-NMR and $^{1}$H-NMR analyses. 

(Synthesis of (5-norbornene-2-yl)trifluoromethyl ketone) 

A 100 ml three-necked flask equipped with a thermometer, cooling tube having a 3-way cock and dropping funnel was charged with 17 g (112 mmol) of 5-norbornene-2-carboxylic acid methyl ester (mixture of endo-form and exo-form) and 0.45 g (3 mmol) of cesium fluoride and was cooled in ice bath in nitrogen gas atmosphere. While maintaining the inside temperature of the flask at 3° to 10° C., 22 g (156 mmol) of CF $_{3}$SiMe$_{3 }$ was added dropwise over two hours with stirring. After increasing the flask temperature to room temperature and stirring for three hours, 2 g (8 mmol) of tetrabutylammo› nium fluoride was added thereto and stirring was carried out for one hour. The reaction solution was poured into ice water, followed by extraction with diethylether. After drying an organic phase with calcium chloride, refining was carried out by distillation under reduced pressure and 12 g (yield: 56%, based on 5-norbornene-2-carboxylic acid methyl ester) of (5-norbornene-2-yl)trifluoromethyl ketone was obtained. 

Physical properties of the obtained product were as fol› lows. 

$^{19}$F-NMR (solvent: CDC1$_{3}$ ): -78.0 (s, CF 3 , exo-form), -78.3 (s, CF$_{3}$ , endo-form) 

MS: 190 (M+), 121 (M+----CF$_{3}$), 66 (C$_{5}$H$_{6}$ ) 

IR: 1753 cm-$^{1 }$(C=O), 1574 cm-$^{1 }$(C=C) 

(Synthesis of (5-norbornene-2-yl)-1,1,1,3,3,3-hexafluoro-2- propanol (NB-1)) 

A 100 ml three-necked flask equipped with a thermometer, cooling tube having a 3-way cock and dropping funnel was charged with 12 g (64 mmol) of (5-norbornene-2-yl)trifluo› romethyl ketone (mixture of endo-form and exo-form), 11 g (79 mmol) ofCF$_{3}$SiMe$_{3 }$ and20ml ofTHF and was cooled in dry ice/acetone bath in nitrogen gas atmosphere. While main- 

## PREPARATION EXAMPLE 1 

## EXAMPLE 1 

## EXAMPLE2 

