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polymer comprises recurring units derived from HFA sty› rene, that is, has fluorine-containing recurring units, it will segregate on the surface of the resist film after spin coating. Because of its robustness and high density, HFA styrene is effective for shutting off outgassing from the photoresist film. Since the polymer comprises recurring units ofHFA styrene dissolves in an alkaline developer, it is also effective for reducing bridge defects between resist pattern features after development. 

Polymeric Additive 

One embodiment of the invention is a resist composition comprising a polymer capable of increasing alkali solubility under the action ofacid, serving as a base resin, and a polymer comprising recurring units derived from HFA styrene, serv- ing as a polymeric additive. Typically, the polymer serving as polymeric additive comprises recurring units having the gen› eral formula (1). 

Herein R $^{1 }$is hydrogen, hydroxyl, a C$_{1 }$-C$_{10 }$straight, branched or cyclic alkyl group, alkoxy group, acyloxy group, cyano group, nitro group, amino group or halogen atom, mis 1 or 2, and 0<psl.0. 

Preferably, the polymer serving as a polymeric additive is a polymer comprising recurring units derived from a styrene having 1,1,1,3,3,3-hexafluoro-2-propanol and optionally, recurring units (ql) and/or (q2) derived from a monomer selected from a styrene and vinylnaphthalene, represented by the general formula (2). 

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Herein R $^{1 }$is hydrogen, hydroxyl, a C$_{1 }$-C$_{10 }$straight, branched or cyclic alkyl group, alkoxy group, acyloxy group, cyano group, nitro group, amino group or halogen atom, and mis 1 or 2. R$^{2 }$andR$^{3 }$each are hydrogen, a C$_{1}$-C$_{6}$ , straight, branched or cyclic alkyl group, alkoxy group, acyl group, acyloxy 60 group, alkoxycarbonyl group, nitro group, cyano group, halo- gen atom, trifluoromethyl group, hydroxyl group or carboxyl group, v is an integer of 1 to 5, and w is an integer of 1 to 7. Subscripts p, ql and q2 are numbers in the range: 0<psl.0, 0sq 1 <1.0, and 0sq2<1.0. 65 

The resist composition having the polymer comprising recurring units of formula (1 ), especially formula (2) added 

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thereto is coated to form a photoresist film. The photoresist film is characterized in that a polymeric surfactant compris› ing recurring units of HFA styrene and optionally, recurring units of styrene or vinylnaphthalene is present on the film surface. The polymeric surfactant segregates on the photore› sist film surface at the end of photoresist coating and func- tions to suppress the release of outgassing components from the resist film and to minimize defects in the resist pattern after development. 

Examples of the monomers from which recurring units (p) ofHFA styrene are derived are shown below, but not limited thereto. 

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(1) 

