having a specific structure with a 1,1,1,3,3,3-hexafluoro-2- propanol residue and are described in JP-A 2007-297590 and JP-A 2008-111103, for example. The water repellency improver to be added to the resist composition should be soluble in the organic solvent as the developer. The water repellency improver of specific structure with a 1,1,1,3,3,3- hexafluoro-2-propanol residue is well soluble in the devel› oper. A polymer having an amino group or amine salt copolymerized as recurring units may serve as the water repellent additive and is effective for preventing evaporation of acid during PEB, thus preventing any hole pattern open› ing failure after development. An appropriate amount of the water repellency improver is Oto 20 parts, preferably 0.5 to 10 parts by weight per 100 parts by weight of the base polymer. 

[0175] Also, an acetylene alcohol may be blended in the resist composition. Suitable acetylene alcohols are described in JP-A 2008-122932, paragraphs [0179]-[0182]. An appro› priate amount of the acetylene alcohol blended is Oto 5 parts by weight per 100 parts by weight of the base polymer. 

## Process 

[0176] The pos1t1ve resist composition is used in the fabrication of various integrated circuits. Pattern formation using the resist composition may be performed by well› known lithography processes. The process generally involves coating, exposure, and development. If necessary, any additional steps may be added. 

[0177] For example, the positive resist composition is first applied onto a substrate on which an integrated circuit is to be formed (e.g., Si, SiO$_{2}$ . SiN, SiON, TiN, WSi, BPSG, SOG, or organic antireflective coating) or a substrate on which a mask circuit is to be formed (e.g., Cr, CrO, CrON, MoSi$_{2}$ , or SiO$_{2}$ ) by a suitable coating technique such as spin coating, roll coating, flow coating, dipping, spraying or doctor coating. The coating is prebaked on a hotplate at a temperature of 60 to 150° C. for 10 seconds to 30 minutes, preferably at 80 to 120° C. for 30 seconds to 20 minutes. The resulting resist film is generally 0.01 to 2 µm thick. 

[0178] The resist film is then exposed to a desired pattern of high-energy radiation such as UV, deep-UV, EB, EUV of wavelength 3 to 15 nm, x-ray, soft x-ray, excimer laser light, y-ray or synchrotron radiation. When UV, deep-UV, EUV, x-ray, soft x-ray, excimer laser light, y-ray or synchrotron radiation is used as the high-energy radiation, the resist film is exposed thereto through a mask having a desired pattern in a dose of preferably about 1 to 200 m/cm 2 , more prefer› ably about 10 to 100 mJ/cm 2 . When EB is used as the high-energy radiation, the resist film is exposed thereto through a mask having a desired pattern or directly in a dose of preferably about 0.1 to 100 µC/cm 2 , more preferably about 0.5 to 50 µC/cm 2 . It is appreciated that the inventive resist composition is suited in micropatterning using KrF excimer laser, ArF excimer laser, EB, EUV, x-ray, soft x-ray, y-ray or synchrotron radiation, especially in micropatterning using EB or EUV. 

[0179] After the exposure, the resist film may be baked (PEB) on a hot plate preferably at 60 to 150’C for 10 seconds to 30 minutes, more preferably at 80 to 120° C. for 30 seconds to 20 minutes. 

[0180] After the exposure or PEB, the resist film is devel› oped in a developer in the form of an aqueous base solution for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes by conventional techniques such as dip, puddle and spray 

techniques. A typical developer is a 0.1 to 10 wt %, preferably 2 to 5 wt % aqueous solution of tetramethylam› monium hydroxide (TMAH), tetraethylammonium hydrox› ide (TEAH), tetrapropylammonium hydroxide (TPAH), or tetrabutylammonium hydroxide (TBAH). The resist film in the exposed area is dissolved in the developer whereas the resist film in the unexposed area is not dissolved. In this way, the desired positive pattern is formed on the substrate. 

[0181] In an alternative embodiment, a negative pattern may be formed via organic solvent development using a positive resist composition comprising a base polymer hav› ing an acid labile group. The developer used herein is preferably selected from among 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropi› onate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, and 2-phenylethyl acetate, and mixtures thereof. 

[0182] At the end of development, the resist film is rinsed. As the rinsing liquid, a solvent which is miscible with the developer and does not dissolve the resist film is preferred. Suitable solvents include alcohols of 3 to 10 carbon atoms, ether compounds of 8 to 12 carbon atoms, alkanes, alkenes, and alkynes of 6 to 12 carbon atoms, and aromatic solvents. Specifically, suitable alcohols of 3 to 10 carbon atoms include n-propyl alcohol, isopropyl alcohol, I-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, t-butyl alcohol, 1-penta› nol, 2-pentanol, 3-pentanol, t-pentyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl- 3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dim› ethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pen› tanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl- 1-pentanol 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, and 1-octanol. Suitable ether compounds of 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-s-butyl ether, di-n-pentyl ether, diisopentyl ether, di-s› pentyl ether, di-t-pentyl ether, and di-n-hexyl ether. Suitable alkanes of 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclo› pentane, dimethylcyclopentane, cyclohexane, methylcyclo› hexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Suitable alkenes of 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclo› hexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Suitable alkynes of 6 to 12 carbon atoms include hexyne, heptyne, and octyne. Suitable aromatic solvents include toluene, xylene, ethylbenzene, isopropyl› benzene, t-butylbenzene and mesitylene. 

[0183] Rinsing is effective for minimizing the risks of resist pattern collapse and defect formation. However, rins- 

