180  US 8,968,979 B2  179  (Sumitomo 3M Co., Ltd.), Asahiguard AG710, Surflon  S-381, S-382, S-386, SC101, SC102, SC103, SC104, SC105,  SC106, KH-10, KH-20, KH-30andKH-40 (Asahi Glass Co.,  Ltd.); organosiloxane polymers KP341, X-70-092 and X-70- 093 (Shin-Etsu Chemical Co., Ltd.), acrylic acid or meth› acrylic acid Polyflow No. 75 and No. 95 (Kyoeisha Ushi  Kagaku Kogyo Co., Ltd.).  Additional useful surfactants include partially fluorinated  oxetane ring-opened polymers having the structural formula  (surf-I).  Further included are organic nitrogen-containing com› pounds of7-oxanorbornane-2-carboxylic ester structure hav› ing the general formula (D)-15.  is 0, 1, 2, 3 or 4. R$^{329 }$is hydrogen, methyl, ethyl or phenyl. X  is a nitrogen atom or CR 330 . Y is a nitrogen atom or CR 331 . Z  is a nitrogen atom or CR 332 . R 330 , R $^{331 }$and R$^{332 }$are each  independently hydrogen, methyl or phenyl. Alternatively, a  pair of R$^{330 }$and R$^{331 }$or a pair of R$^{331 }$and R$^{332 }$may bond 5  together to form a  CcC$_{20 }$ aromatic ring or C$_{2}$ -C$_{20 }$hetero› aromatic ring with the carbon atom to which they are  attached.  Herein R 333  is hydrogen or a straight, branched or cyclic  C$_{1 }$-C$_{10 }$alkyl group. R$^{334 }$and R$^{335 }$are each independently a  C$_{1 }$-C$_{20 }$ alkyl group,  CcC$_{20 }$ aryl group or C$_{7}$-C$_{20 }$ aralkyl  group, which may contain one or more polar functional  groups selected from among ether, carbonyl, ester, alcohol,  sulfide, nitrile, amine, imine, and amide and in which some  hydrogen atoms may be replaced by halogen atoms. R$^{334 }$and  R 335 , taken together, may form a heterocyclic or hetero-aro› matic ring of 2 to 20 carbon atoms with the nitrogen atom to  which they are attached.  It is provided herein that R, Rf, A, B, C, m’, and n’ are applied  to only formula (surf-1), independent of their descriptions  other than for the surfactant.Risa di- to tetra-valent C$_{2}$-C$_{5 }$ aliphatic group. Exemplary divalent groups include ethylene,  1,4-butylene,  1,2-propylene,  2,2-dimethyl-1,3-propylene  and 1,5-pentylene. Exemplary tri- and tetra-valent groups are  shown below.  Also useful as the basic component are basic compounds of  amine oxide structure which is oxidized on nitrogen.  Examples  include  tris(2-(methoxymethoxy)ethyl)amine  oxide, 2,2’ ,2"-nitrilotriethylpropionate N-oxide, and N-2-( (2- methoxyethoxy )methoxyethy lmorpholine N-oxide.  The organic nitrogen-containing compounds may be used  alone or in admixture of two or more. The organic nitrogen› containing compound (D) is preferably formulated in an  amount of0.001 to 4 parts, and especially 0.01 to 2 parts by  weight, per 100 parts by weight of the entire base resin. Less  than 0.001  part of the nitrogen-containing compound  achieves no or little addition effect whereas more than 4 parts  may result in too low a sensitivity.  Surfactant  Optionally, the resist composition of the invention may  further comprise a surfactant which is commonly used for  facilitating the coating operation. The surfactant may be  added in conventional amounts so long as this does not com› promise the objects of the invention.  Illustrative, non-limiting examples of the surfactant  include nonionic surfactants, for example, polyoxyethylene  alkyl ethers such as polyoxyethylene lauryl ether, polyoxy› ethylene stearyl ether, polyoxyethylene cetyl ether, and poly› oxyethylene oleyl ether, polyoxyethylene alkylaryl ethers  such as polyoxyethylene octylphenol ether and polyoxyeth› ylene nonylphenol ether, polyoxyethylene polyoxypropylene  block copolymers, sorbitan fatty acid esters such as sorbitan  monolaurate,  sorbitan  monopalmitate,  and  sorbitan  monostearate, and polyoxyethylene sorbitan fatty acid esters  such as polyoxyethylene sorbitan monolaurate, polyoxyeth› ylene sorbitan monopalmitate, polyoxyethylene sorbitan  monostearate, polyoxyethylene sorbitan trioleate, and poly› oxyethylene sorbitan tristearate; fluorochemical surfactants  such as EFTOP EF301, EF303 and EF352 (JEMCO Inc.),  Megaface F171, Fl 72, Fl 73, ROS, R30, R90 and R94 (DIC  Corp.), Fluorad FC-430, FC-431, FC-4430 and FC-4432  Herein the broken line denotes a valence bond. These formu- lae are partial structures derived from glycerol, trimethylol  ethane, trimethylol propane, and pentaerythritol, respec› tively. Of these, 1,4-butylene and 2,2-dimethyl-1,3-propy› lene are preferably used.  Rf is trifluoromethyl or pentafluoroethyl, and preferably  trifluoromethyl. The letter m’ is an integer of Oto 3, n’ is an  integerofl to 4, and the sum of m’ andn’, which represents the  valence of R, is an integer of 2 to 4. A is equal to 1, B is an  integer of 2 to 25, and C is an integer ofO to 10. Preferably, B  is an integer of 4 to 20, and C is 0 or 1. Note that the above  structural formula does not prescribe the arrangement of  respective constituent units while they may be arranged either  in blocks or randomly. For the preparation of surfactants in  the form of partially fluorinated oxetane ring-opened poly- mers, reference should be made to U.S. Pat. No. 5,650,483,  for example.  In the resist composition, the surfactant is preferably com› pounded in an amount ofup to 2 parts, and especially up to 1  Of the foregoing surfactants, FC-4430, Surflon 5-381,  KH-20, KH-30, and oxetane ring-opened polymers of for› mula (surf-I) are preferred. These surfactants may be used  alone or in admixture.  (surf-!)  Rf]  ~Of,+R7iO~O~OHl  (D)-15 