101  US 7,649,118 B2  102  PREPARATION EXAMPLE 1  EXAMPLE 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- (Synthesis of (5-norbornene-2-yl)-1,1,1,3,3,3-hexafluoro-2- propanol (NB-1))  EXAMPLE2  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.  (Synthesis of (5-norbornene-2-yl)trifluoromethyl ketone)  In the following Examples and Preparation Examples,  equipment and measuring conditions used for evaluation of  physical properties are as follows.  The present invention is then explained below by means of $_{40 }$ Examples and Preparation Examples, but is not limited to  them.  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 above-mentioned structure of this compound was  determined by GC-Mass, $^{19}$F-NMR and $^{1}$H-NMR analyses.  (melting point: 73°  to 75°  C./45 mmHg) which is a nor› bornene compound having --CO F group (yield: 90%)  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.  The reaction mixture was subjected to distillation under  reduced pressure to obtain 3 60 g of 5-norbornene-2-carboxy› lic acid fluoride:  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.  (Synthesis ofNorbornene Having --COP Group)  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.  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.  benzotrifluoride,  perfluorobenzene,  perfluoro(tributy- lamine ), ClCF$_{2}$CFClCF$_{2}$CFCl$_{2 }$ and the like.  F  (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.  $^{19}$F-NMR (solvent: CDC1$_{3}$ ): -78.0 (s, CF 3 ,  exo-form),  -78.3 (s, CF$_{3}$ ,  endo-form)  IR: 1753 cm-$^{1 }$(C=O), 1574 cm-$^{1 }$(C=C)  MS: 190 (M+), 121 (M+----CF$_{3}$), 66 (C$_{5}$H$_{6}$ ) 