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Herein R $^{11 }$is fluorine or an organic group selected from the group consisting of trifluoromethyl, pentafluoroethyl, trif› luoroethyl, octafluorobutyl, nonafluorobutyl, 2-fluorophe- nyl, 3-fluorophenyl, 4-fluorophenyl, 2,4-difluorophenyl, 2,3-difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl, 

2,4,5-trifluorophenyl, 2,3,4-trifluorophenyl, 2,3,4,5-tetra› fluorophenyl, 2,3,5,6-tetrafluorophenyl, 2,3,4,5,6-pentafluo› rophenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl, 4-trifluoromethylphenyl, 2,4-di(trifluoromethyl)phenyl, 4-hydroxy-2,3,5,6-tetrafluorophenyl, 4-methoxy-2,3,5,6-tet› rafluorophenyl, 4-acetoxy-2,3,5,6-tetrafluorophenyl, 4-piv› aloyloxy-2,3 ,5, 6-tetrafluoropheny 1, 4-cyclohexy lcarbony› loxy-2,3 ,5 ,6-tetrafluoropheny l, 4-adamantylcarbonyloxy-2, 3,5,6-tetrafluorophenyl, 4-phenylcarbonyloxy-2,3,5,6- tetrafluorophenyl, 4-cyclohexylsulfonyl-2,3,5,6- tetrafluorophenyl, and 4-phenylsulfonyl-2,3,5,6- tetrafluorophenyl; R 15 , R 16 , R 17 , R 18 , and R 19 are each independently fluorine, trifluoromethyl, pentafluoroethyl, trifluoroethyl, octafluorobutyl, or nonafluorobutyl, R 15 and R$^{16 }$may bond together to form a ring; R 20 , R 21 , R 22 , and R 23 are each independently fluorine or trifluoromethyl, each of p, q, r and s is an integer of 1 to 5. 

Typically, the resist composition is a chemically amplified positive resist composition. 

The resist composition may further comprise at least one component selected from among an organic solvent, a dissolution inhibitor, an acid generator, a basic compound, and a surfactant. 

In another aspect, the invention provides a pattern form- ing process comprising the steps of coating the resist com› position defined above onto a substrate, baking, exposing the resulting resist film to high-energy radiation, and developing with a developer. 

Preferably, the high-energy radiation is EUV radiation having a wavelength of 3 to 15 nm or an EB at an accelerating voltage of 1 to 150 keV. 

In the step of exposing the resist film to high-energy radiation, preferably the surface of the substrate underneath the resist film is electrically charged positive. 

The resist composition has many advantages including a significantly high contrast of alkaline dissolution rate before and after exposure, a high sensitivity, a high resolution, a satisfactory pattern profile after exposure, a controlled rate of acid diffusion, and a minimal line edge roughness. The resist composition, typically chemically amplified positive resist composition is suited as the micropatterning material for VLSis and photomasks, and the patterning material in the EB and EUV lithography. 

The singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. As used herein, the notation (Cn-Cm) means a group containing from n to m carbon atoms per group. 

The abbreviations and acronyms have the following meaning. 

UV: ultraviolet radiation 

DUY: deep ultraviolet 

EUV: extreme ultraviolet 

EB: electron beam 

Mw: weight average molecular weight 

Mn: number average molecular weight 

Mw/Mn: molecular weight distribution or dispersity 

GPC: gel permeation chromatography 

## Advantageous Effects of Invention 

## DESCRIPTION OF EMBODIMENTS 

