Apr. 18,  2019  24  US 2019/0113844 Al  [0069]  In formula (AL-3),  RL 5 ,  RL 6  and  RL $^{7 }$are each  independently a C$_{1 }$-C$_{20 }$ 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, with C$_{1 }$-C$_{20 }$ alkyl  groups being preferred. Any two of  RL 5 ,  RL 6  and  RL $^{7 }$may  bond together to form a ring with the carbon atom to which  they are attached. The ring contains 3 to 20 carbon atoms,  preferably 4 to 16 carbon atoms and is typically alicyclic.  [0070]  The base polymer may further comprise recurring  units (b) having a phenolic hydroxyl group as an adhesive  group. Examples of suitable monomers from which recur› ring units (b) are derived are given below, but not limited  thereto. Herein  RA  is as defined above.  [0065]  The acid labile groups represented by R$^{11 }$and R 12  in the recurring units (al) and (a2) may be selected from a  variety of such groups, for example, those groups described  in JP-A 2013-080033 (U.S. Pat. No. 8,574,817) and JP-A  2013-083821 (U.S. Pat. No. 8,846,303).  [0066]  Typical of the acid labile group are groups of the  following formulae (AL-1) to (AL-3).  [0067]  In formulae (AL-1) and (AL-2),  RL 1  and  RL 2  are  each independently a C$_{1 }$-C$_{40 }$ 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, with alkyl  groups of 1 to 40 carbon atoms, especially 1 to 20 carbon  atoms being preferred. In formula (AL-1), "a" is an integer  of 0 to 10, especially 1 to 5.  [0068]  In formula (AL-2),  RL 3  and  RL 4  are each indepen› dently hydrogen or a C$_{1 }$-C$_{20 }$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, with C$_{1 }$-C$_{20 }$ alkyl  groups being preferred. Any two of  RL2, RL 3  and  RL 4  may  bond together to form a ring with the carbon atom or carbon  and oxygen atoms to which they are attached. The ring  contains 3 to 20 carbon atoms, preferably 4 to 16 carbon  atoms, and is typically alicyclic.  OR12  XR’  XR’  XR’  0  0  0  0  0  0  I~  I~  ¢  Q  & OR12  #  OR12  #  OR12  (AL-1)  (AL-2)  (AL-3)  XR’  0  0  6  HO  OH 