Nitrogen-containing organic compound, chemically amplified resist composition and patterning process

1. A nitrogen-containing organic compound having a 7-oxanorbornane-2-carboxylic ester structure, represented by the general formula (1):

wherein R 1 is hydrogen or a straight, branched or cyclic C 1 -C 10 alkyl group; R 2 and R 3 are each independently a C 1 -C 20 alkyl group, C 6 -C 20 aryl group or C 7 -C 20 aralkyl group which may contain at least one polar functional group selected from the group consisting of ether, carbonyl, ester, alcohol, sulfide, nitrile, amine, imine and amide, and wherein the hydrogen atoms of R 2 and R 3 may be substituted with halogen atoms, or R 2 and R 3 , taken together, may form a heterocyclic or heteroaromatic ring of 2 to 20 carbon atoms with the nitrogen atom to which they are attached.

2. A chemically amplified resist composition comprising at least one nitrogen-containing organic compound of claim 1 .

3. A chemically amplified resist composition comprising

(A) the nitrogen-containing organic compound of claim 1 ,

(B) an organic solvent,

(C) a base resin having an acid labile group-protected acidic functional group which is alkali-insoluble or substantially alkali-insoluble, but becomes alkali-soluble when the acid labile group is eliminated, and

(D) a photoacid generator.

4. A patterning process comprising the steps of:

(1) applying the chemically amplified resist composition of claim 2 onto a substrate;

(2) heat treating the applied resist, then exposing the heat-treated resist through a photomask to high-energy radiation having a wavelength of up to 300 nm or an electron beam; and

(3) heat treating the exposed resist, then developing the resist with a liquid developer. 0