70  US 7,410,747 B2  69  X $^{2 }$in formula (IIb) contains an alicyclic structure, an aro› matic ring structure, or both of an alicyclic structure and  an aromatic ring structure;  X 3  in formula (IIdl) contains an alicyclic structure, an  aromatic ring structure, or both of an alicyclic structure  and an aromatic ring structure; and  at least one of X 2  in formula (Ile) contains an alicyclic  structure, an aromatic ring structure, or both of an ali› cyclic structure and an aromatic ring structure.  X 2  represents a hydrogen atom or an organic group, and  when q’ represents an integer of 2 to  4,  a plurality ofX $^{2}$s  may be the same or different,  at least one of X in formula (Ila) contains an alicyclic  structure, an aromatic ring structure, or both of an ali› cyclic structure and an aromatic ring structure;  20.  The positive resist composition as claimed in claim  7,  wherein X $^{1 }$in formula (III) contains an alicyclic structure, an  aromatic ring structure, or both an alicyclic structure and an  aromatic ring structure.  *  *  *  *  *  acyloxy group, and said alkyl group and said aralkyl group  each may have an intervening linking group represented by  -0-,  -S-,  --CO$_{2}$-,  -CO-, -SO$_{2}$-or-SO-, and  when t’ represents an integer 2 to  4,  a plurality ofRII_$_{2}$s may  be the same or different, and a plurality ofRII_$_{2}$s may combine  with each other to form a ring structure,  19.  The positive resist composition as claimed in claim  1,  wherein  q’ represents an integer of 0 to  4,  and  t’ represents an integer of Oto  4.  Y$_{2 }$ represents a divalent linking group, and  RII_$_{2 }$ and Y$_{2 }$ 10  may combine to form a ring structure, 