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In formulae (AL-1) and (AL-2), RL 1 and RL 2 are each independently a monovalent hydrocarbon group which may contain a heteroatom such as oxygen, sulfur, nitrogen or fluorine. The monovalent hydrocarbon groups may be straight, branched or cyclic, and are preferably alkyl groups 5 of 1 to 40 carbon atoms, more preferably 1 to 20 carbon atoms. In formula (AL-1), "a" is an integer of 0 to 10, especially 1 to 5. 3 4 

In formula (AL-2), RL and RL are each independently hydrogen or a monovalent hydrocarbon group which may contain a heteroatom such as oxygen, sulfur, nitrogen or fluorine. The monovalent hydrocarbon groups may be straight, branched or cyclic, and are preferably alkyl groups of 1 to 20 carbon atoms. Any two ofRL2, RL 3 and RL 4 may bond together to form a ring, especially alicyclic, with the carbon atom or carbon and oxygen atoms to which they are attached, the ring containing 3 to 20 carbon atoms, prefer› ably 4 to 16 carbon atoms. 5 6 

In formula (AL-3), RL , RL and Rn are each indepen› dently a monovalent hydrocarbon group which may contain a heteroatom such as oxygen, sulfur, nitrogen or fluorine. The monovalent hydrocarbon groups may be straight, branched or cyclic, and are preferably alkyl groups of 1 to 20 carbon atoms. Any two of RL 5 , RL 6 and RL 7 may bond together to form a ring, especially alicyclic, with the carbon atom to which they are attached, the ring containing 3 to 20 carbon atoms, preferably 4 to 16 carbon atoms. 

As the recurring units (b ), recurring units which switch from hydrophilic to hydrophobic due to dehydration reaction with the aid of acid, referred to as recurring units (b3), may also be used. When recurring units (b3) are used, the resist composition of the invention may be used as a negative resist composition adapted to form a negative pattern via alkaline development. 

Examples of the monomer from which recurring units (b3) are derived are given below, but not limited thereto. Herein RA is as defined above. 

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